update to Gradle 8.1.1, Java 17

.travis.yml

@@ -1,7 +0,0 @@
-sudo: false
-language: java
-jdk:
-  - oraclejdk8
-cache:
-  directories:
-    - $HOME/.m2

README.md

@@ -1,24 +1,25 @@
-# Guice
+= Guice - simplified and reduced version
 
-This is a xbib Guice, a build of Guice with the following differences to the 
+This is xbib Guice, a build of Google Guice with the following differences to the 
 original [Google Guice Core Library](https://github.com/google/guice):
 
 - only external dependencies are 
  - javax.inject:javax.inject:1
- - javax.annotation:javax.annotation-api:1.2
- - com.google.guava:guava:19.0
+ - org.xbib:jsr-305:1.0.0
+ - com.google.guava:guava:30.1
+
 - the extra AOP stuff was removed (aopalliance/cglib), no intercepting any more
 - removed all logging, uses of java.util.logger.* stuff and logger default binding
-- removed all java.io.Serializable dependent stuff
+- removed all java.io.Serializable dependent stuff. Note: everything which relies to be serializable was removed.
 - reformatted source by IntelliJ and cleaned up source of @author and @since tags
-- target of compilation is Java 8, no support for Java 6/7
+- target of compilation is Java 11, no support for Java 6/7
 - introduced Gradle as build system
-- junit tests made compatible to junit 4.12
-- assistedinject and multibindings extension included
+- junit tests made compatible to junit 4
+- assistedinject and multibindings extensions are included
 
 All credits belong to the original authors, especially Bob Lee http://blog.crazybob.org/
 
-## License
+== License
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.

build.gradle

@@ -1,85 +1,51 @@
-
-group = 'org.xbib'
-version = '4.0'
-
-apply plugin: 'java'
-apply plugin: 'maven'
-
-repositories {
-    mavenCentral()
-    mavenLocal()
-    jcenter()
-    maven {
-        url "http://xbib.org/repository"
-    }
+plugins {
+    //id "checkstyle"
+    //id "pmd"
+    id 'maven-publish'
+    id 'signing'
+    id "io.github.gradle-nexus.publish-plugin" version "1.3.0"
+    //id "com.github.spotbugs" version "5.0.14"
+    id "org.cyclonedx.bom" version "1.7.2"
+    //id "org.xbib.gradle.plugin.asciidoctor" version "3.0.0"
 }
 
-configurations {
-    wagon
+wrapper {
+    gradleVersion = libs.versions.gradle.get()
+    distributionType = Wrapper.DistributionType.ALL
 }
 
+ext {
+    user = 'joerg'
+    name = 'guice'
+    description = 'Guice implementation with named modules for Java 11+'
+    inceptionYear = '2012'
+    url = 'https://xbib.org/' + user + '/' + name
+    scmUrl = 'https://xbib.org/' + user + '/' + name
+    scmConnection = 'scm:git:git://xbib.org/' + user + '/' + name + '.git'
+    scmDeveloperConnection = 'scm:git:ssh://forgejo@xbib.org:' + user + '/' + name + '.git'
+    issueManagementSystem = 'Github'
+    issueManagementUrl = ext.scmUrl + '/issues'
+    licenseName = 'The Apache License, Version 2.0'
+    licenseUrl = 'http://www.apache.org/licenses/LICENSE-2.0.txt'
+}
+
+apply plugin: 'java-library'
+apply from: rootProject.file('gradle/init/banner.gradle')
+apply from: rootProject.file('gradle/ide/idea.gradle')
+apply from: rootProject.file('gradle/repositories/maven.gradle')
+apply from: rootProject.file('gradle/compile/java.gradle')
+apply from: rootProject.file('gradle/test/junit5.gradle')
+apply from: rootProject.file('gradle/quality/cyclonedx.gradle')
+//apply from: rootProject.file('gradle/quality/spotbugs.gradle')
+//apply from: rootProject.file('gradle/quality/checkstyle.gradle')
+//apply from: rootProject.file('gradle/quality/pmd.gradle')
+apply from: rootProject.file('gradle/publish/sonatype.gradle')
+apply from: rootProject.file('gradle/publish/forgejo.gradle')
+
 dependencies {
-    compile "javax.inject:javax.inject:1"
-    compile 'javax.annotation:javax.annotation-api:1.2'
-    compile "com.google.guava:guava:19.0"
-    testCompile "junit:junit:4.12"
-    testCompile "org.apache.logging.log4j:log4j-slf4j-impl:2.5"
-    testCompile "org.apache.logging.log4j:log4j-core:2.5"
-    testCompile "javax.inject:javax.inject-tck:1"
-    testCompile "com.google.guava:guava-testlib:19.0"
-    wagon 'org.apache.maven.wagon:wagon-ssh-external:2.10'
-}
-
-sourceCompatibility = 1.8
-targetCompatibility = 1.8
-
-[compileJava, compileTestJava]*.options.collect { options ->
-    options.encoding = 'UTF-8'
-    options.compilerArgs << '-Xlint:-serial,-path,-rawtypes,-unchecked'
-}
-
-test {
-    exclude '*$*'
-    exclude '**/ErrorHandlingTest*'
-    exclude '**/OSGiContainerTest*'
-    exclude '**/ScopesTest*'
-    exclude '**/TypeConversionTest*'
-    testLogging {
-        showStandardStreams = false
-        exceptionFormat = 'full'
-    }
-}
-
-task sourcesJar(type: Jar, dependsOn: classes) {
-    from sourceSets.main.allSource
-    classifier 'sources'
-}
-
-artifacts {
-    archives sourcesJar
-}
-
-uploadArchives {
-    repositories {
-        if (project.hasProperty("xbibUsername")) {
-            mavenDeployer {
-                configuration = configurations.wagon
-                repository(
-                        id: 'xbib.org',
-                        url: uri('scpexe://xbib.org/repository'),
-                        authentication: [userName: xbibUsername, privateKey: xbibPrivateKey]
-                )
-                pom.project {
-                    inceptionYear '2016'
-                    licenses {
-                        license {
-                            name 'The Apache Software License, Version 2.0'
-                            url 'http://www.apache.org/licenses/LICENSE-2.0.txt'
-                            distribution 'repo'
-                        }
-                    }
-                }
-            }
-        }
-    }
+    api libs.javax.inject
+    api libs.guava
+    testImplementation libs.junit4
+    // Helper for com.google.common.testing.GcFinalization, com.google.common.testing.EqualsTester
+    testImplementation libs.guava.testlib
 }

gradle.properties

@@ -0,0 +1,5 @@
+group = org.xbib
+name = guice
+version = 5.0.1.0
+
+org.gradle.warning.mode = ALL

gradle/compile/java.gradle

@@ -0,0 +1,33 @@
+
+apply plugin: 'java-library'
+
+java {
+    modularity.inferModulePath.set(true)
+    withSourcesJar()
+    withJavadocJar()
+}
+
+compileJava {
+    sourceCompatibility = JavaVersion.VERSION_17
+    targetCompatibility = JavaVersion.VERSION_17
+}
+
+compileTestJava {
+    sourceCompatibility = JavaVersion.VERSION_17
+    targetCompatibility = JavaVersion.VERSION_17
+}
+
+jar {
+    manifest {
+        attributes('Implementation-Version': project.version)
+    }
+}
+
+tasks.withType(JavaCompile) {
+    options.encoding('UTF-8')
+    options.compilerArgs << '-Xlint:all'
+}
+
+javadoc {
+    options.addStringOption('Xdoclint:none', '-quiet')
+}

gradle/documentation/asciidoc.gradle

@@ -0,0 +1,55 @@
+apply plugin: 'org.xbib.gradle.plugin.asciidoctor'
+
+configurations {
+    asciidoclet
+}
+
+dependencies {
+    asciidoclet "org.asciidoctor:asciidoclet:${project.property('asciidoclet.version')}"
+}
+
+
+asciidoctor {
+    backends 'html5'
+    outputDir = file("${rootProject.projectDir}/docs")
+    separateOutputDirs = false
+    attributes 'source-highlighter': 'coderay',
+            idprefix: '',
+            idseparator: '-',
+            toc: 'left',
+            doctype: 'book',
+            icons: 'font',
+            encoding: 'utf-8',
+            sectlink: true,
+            sectanchors: true,
+            linkattrs: true,
+            imagesdir: 'img',
+            stylesheet: "${projectDir}/src/docs/asciidoc/css/foundation.css"
+}
+
+
+/*javadoc {
+options.docletpath = configurations.asciidoclet.files.asType(List)
+options.doclet = 'org.asciidoctor.Asciidoclet'
+//options.overview = "src/docs/asciidoclet/overview.adoc"
+options.addStringOption "-base-dir", "${projectDir}"
+options.addStringOption "-attribute",
+        "name=${project.name},version=${project.version},title-link=https://github.com/xbib/${project.name}"
+configure(options) {
+    noTimestamp = true
+}
+}*/
+
+
+/*javadoc {
+    options.docletpath = configurations.asciidoclet.files.asType(List)
+    options.doclet = 'org.asciidoctor.Asciidoclet'
+    options.overview = "${rootProject.projectDir}/src/docs/asciidoclet/overview.adoc"
+    options.addStringOption "-base-dir", "${projectDir}"
+    options.addStringOption "-attribute",
+            "name=${project.name},version=${project.version},title-link=https://github.com/xbib/${project.name}"
+    options.destinationDirectory(file("${projectDir}/docs/javadoc"))
+    configure(options) {
+        noTimestamp = true
+    }
+}*/

gradle/ide/idea.gradle

@@ -0,0 +1,12 @@
+apply plugin: 'idea'
+
+idea {
+    module {
+        outputDir file('build/classes/java/main')
+        testOutputDir file('build/classes/java/test')
+    }
+}
+
+clean {
+    delete 'out'
+}

gradle/init/banner.gradle

@@ -0,0 +1,14 @@
+gradle.projectsLoaded { g ->
+    printf "Host: %s\nOS: %s %s %s\nJVM: %s %s %s %s\nGradle: %s Groovy: %s Java: %s\n" +
+            "Build: group: %s name: %s version: %s\n",
+            InetAddress.getLocalHost(),
+            System.getProperty("os.name"),
+            System.getProperty("os.arch"),
+            System.getProperty("os.version"),
+            System.getProperty("java.version"),
+            System.getProperty("java.vm.version"),
+            System.getProperty("java.vm.vendor"),
+            System.getProperty("java.vm.name"),
+            gradle.gradleVersion, GroovySystem.getVersion(), JavaVersion.current(),
+            gradle.rootProject.group, gradle.rootProject.name, gradle.rootProject.version
+}

gradle/publish/forgejo.gradle

@@ -0,0 +1,16 @@
+if (project.hasProperty('forgeJoToken')) {
+    publishing {
+        repositories {
+            maven {
+                url 'https://xbib.org/api/packages/joerg/maven'
+                credentials(HttpHeaderCredentials) {
+                    name = "Authorization"
+                    value = "token ${project.property('forgeJoToken')}"
+                }
+                authentication {
+                    header(HttpHeaderAuthentication)
+                }
+            }
+        }
+    }
+}

gradle/publish/ivy.gradle

@@ -0,0 +1,27 @@
+apply plugin: 'ivy-publish'
+
+publishing {
+    repositories {
+        ivy {
+            url = "https://xbib.org/repo"
+        }
+    }
+    publications {
+        ivy(IvyPublication) {
+            from components.java
+            descriptor {
+                license {
+                    name = 'The Apache License, Version 2.0'
+                    url = 'http://www.apache.org/licenses/LICENSE-2.0.txt'
+                }
+                author {
+                    name = 'Jörg Prante'
+                    url = 'https://xbib.org/joerg'
+                }
+                descriptor.description {
+                    text = rootProject.ext.description
+                }
+            }
+        }
+    }
+}

gradle/publish/maven.gradle

@@ -0,0 +1,51 @@
+
+publishing {
+    publications {
+        "${project.name}"(MavenPublication) {
+            from components.java
+            pom {
+                artifactId = project.name
+                name = project.name
+                description = rootProject.ext.description
+                url = rootProject.ext.url
+                inceptionYear = rootProject.ext.inceptionYear
+                packaging = 'jar'
+                organization {
+                    name = 'xbib'
+                    url = 'https://xbib.org'
+                }
+                developers {
+                    developer {
+                        id = 'joerg'
+                        name = 'Jörg Prante'
+                        email = 'joergprante@gmail.com'
+                        url = 'https://xbib.org/joerg'
+                    }
+                }
+                scm {
+                    url = rootProject.ext.scmUrl
+                    connection = rootProject.ext.scmConnection
+                    developerConnection = rootProject.ext.scmDeveloperConnection
+                }
+                issueManagement {
+                    system = rootProject.ext.issueManagementSystem
+                    url = rootProject.ext.issueManagementUrl
+                }
+                licenses {
+                    license {
+                        name = rootProject.ext.licenseName
+                        url = rootProject.ext.licenseUrl
+                        distribution = 'repo'
+                    }
+                }
+            }
+        }
+    }
+}
+
+if (project.hasProperty("signing.keyId")) {
+    apply plugin: 'signing'
+    signing {
+        sign publishing.publications."${project.name}"
+    }
+}

gradle/publish/sonatype.gradle

@@ -0,0 +1,11 @@
+if (project.hasProperty('ossrhUsername') && project.hasProperty('ossrhPassword')) {
+    nexusPublishing {
+        repositories {
+            sonatype {
+                username = project.property('ossrhUsername')
+                password = project.property('ossrhPassword')
+                packageGroup = "org.xbib"
+            }
+        }
+    }
+}

gradle/quality/checkstyle.gradle

@@ -0,0 +1,19 @@
+
+apply plugin: 'checkstyle'
+
+tasks.withType(Checkstyle) {
+    ignoreFailures = true
+    reports {
+        xml.getRequired().set(true)
+        html.getRequired().set(true)
+    }
+}
+
+checkstyle {
+    configFile = rootProject.file('gradle/quality/checkstyle.xml')
+    ignoreFailures = true
+    showViolations = true
+    checkstyleMain {
+        source = sourceSets.main.allSource
+    }
+}

gradle/quality/checkstyle.xml

@@ -0,0 +1,333 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE module PUBLIC
+        "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
+        "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
+
+<!-- This is a checkstyle configuration file. For descriptions of
+what the following rules do, please see the checkstyle configuration
+page at http://checkstyle.sourceforge.net/config.html -->
+
+<module name="Checker">
+
+    <module name="BeforeExecutionExclusionFileFilter">
+        <property name="fileNamePattern" value=".*(Example|Test|module-info)(\$.*)?"/>
+    </module>
+
+    <module name="FileTabCharacter">
+        <!-- Checks that there are no tab characters in the file.
+        -->
+    </module>
+
+    <module name="NewlineAtEndOfFile">
+        <property name="lineSeparator" value="lf"/>
+    </module>
+
+    <module name="RegexpSingleline">
+        <!-- Checks that FIXME is not used in comments.  TODO is preferred.
+        -->
+        <property name="format" value="((//.*)|(\*.*))FIXME" />
+        <property name="message" value='TODO is preferred to FIXME.  e.g. "TODO(johndoe): Refactor when v2 is released."' />
+    </module>
+
+    <module name="RegexpSingleline">
+        <!-- Checks that TODOs are named.  (Actually, just that they are followed
+             by an open paren.)
+        -->
+        <property name="format" value="((//.*)|(\*.*))TODO[^(]" />
+        <property name="message" value='All TODOs should be named.  e.g. "TODO(johndoe): Refactor when v2 is released."' />
+    </module>
+
+    <module name="JavadocPackage">
+        <!-- Checks that each Java package has a Javadoc file used for commenting.
+          Only allows a package-info.java, not package.html. -->
+    </module>
+
+    <!-- All Java AST specific tests live under TreeWalker module. -->
+    <module name="TreeWalker">
+
+        <!--
+
+        IMPORT CHECKS
+
+        -->
+
+        <module name="RedundantImport">
+            <!-- Checks for redundant import statements. -->
+            <property name="severity" value="error"/>
+        </module>
+
+        <module name="ImportOrder">
+            <!-- Checks for out of order import statements. -->
+
+            <property name="severity" value="warning"/>
+            <!-- <property name="tokens" value="IMPORT, STATIC_IMPORT"/> -->
+            <property name="separated" value="false"/>
+            <property name="groups" value="*"/>
+            <!-- <property name="option" value="above"/> -->
+            <property name="sortStaticImportsAlphabetically" value="true"/>
+        </module>
+
+        <module name="CustomImportOrder">
+            <!-- <property name="customImportOrderRules" value="THIRD_PARTY_PACKAGE###SPECIAL_IMPORTS###STANDARD_JAVA_PACKAGE###STATIC"/> -->
+            <!-- <property name="specialImportsRegExp" value="^javax\."/> -->
+            <!-- <property name="standardPackageRegExp" value="^java\."/> -->
+            <property name="sortImportsInGroupAlphabetically" value="true"/>
+            <property name="separateLineBetweenGroups" value="false"/>
+        </module>
+
+        <!--
+
+        JAVADOC CHECKS
+
+        -->
+
+        <!-- Checks for Javadoc comments.                     -->
+        <!-- See http://checkstyle.sf.net/config_javadoc.html -->
+        <module name="JavadocMethod">
+            <property name="accessModifiers" value="protected"/>
+            <property name="severity" value="warning"/>
+            <property name="allowMissingParamTags" value="true"/>
+            <property name="allowMissingReturnTag" value="true"/>
+        </module>
+
+        <module name="JavadocType">
+            <property name="scope" value="protected"/>
+            <property name="severity" value="error"/>
+        </module>
+
+        <module name="JavadocStyle">
+            <property name="severity" value="warning"/>
+        </module>
+
+        <!--
+
+        NAMING CHECKS
+
+        -->
+
+        <!-- Item 38 - Adhere to generally accepted naming conventions -->
+
+        <module name="PackageName">
+            <!-- Validates identifiers for package names against the
+              supplied expression. -->
+            <!-- Here the default checkstyle rule restricts package name parts to
+              seven characters, this is not in line with common practice at Google.
+            -->
+            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]{1,})*$"/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="TypeNameCheck">
+            <!-- Validates static, final fields against the
+            expression "^[A-Z][a-zA-Z0-9]*$". -->
+            <metadata name="altname" value="TypeName"/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="ConstantNameCheck">
+            <!-- Validates non-private, static, final fields against the supplied
+            public/package final fields "^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$". -->
+            <metadata name="altname" value="ConstantName"/>
+            <property name="applyToPublic" value="true"/>
+            <property name="applyToProtected" value="true"/>
+            <property name="applyToPackage" value="true"/>
+            <property name="applyToPrivate" value="false"/>
+            <property name="format" value="^([A-Z][A-Z0-9]*(_[A-Z0-9]+)*|FLAG_.*)$"/>
+            <message key="name.invalidPattern"
+                     value="Variable ''{0}'' should be in ALL_CAPS (if it is a constant) or be private (otherwise)."/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="StaticVariableNameCheck">
+            <!-- Validates static, non-final fields against the supplied
+            expression "^[a-z][a-zA-Z0-9]*_?$". -->
+            <metadata name="altname" value="StaticVariableName"/>
+            <property name="applyToPublic" value="true"/>
+            <property name="applyToProtected" value="true"/>
+            <property name="applyToPackage" value="true"/>
+            <property name="applyToPrivate" value="true"/>
+            <property name="format" value="^[a-z][a-zA-Z0-9]*_?$"/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="MemberNameCheck">
+            <!-- Validates non-static members against the supplied expression. -->
+            <metadata name="altname" value="MemberName"/>
+            <property name="applyToPublic" value="true"/>
+            <property name="applyToProtected" value="true"/>
+            <property name="applyToPackage" value="true"/>
+            <property name="applyToPrivate" value="true"/>
+            <property name="format" value="^[a-z][a-zA-Z0-9]*$"/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="MethodNameCheck">
+            <!-- Validates identifiers for method names. -->
+            <metadata name="altname" value="MethodName"/>
+            <property name="format" value="^[a-z][a-zA-Z0-9]*(_[a-zA-Z0-9]+)*$"/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="ParameterName">
+            <!-- Validates identifiers for method parameters against the
+              expression "^[a-z][a-zA-Z0-9]*$". -->
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="LocalFinalVariableName">
+            <!-- Validates identifiers for local final variables against the
+              expression "^[a-z][a-zA-Z0-9]*$". -->
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="LocalVariableName">
+            <!-- Validates identifiers for local variables against the
+              expression "^[a-z][a-zA-Z0-9]*$". -->
+            <property name="severity" value="warning"/>
+        </module>
+
+
+        <!--
+
+        LENGTH and CODING CHECKS
+
+        -->
+
+
+        <module name="LeftCurly">
+            <!-- Checks for placement of the left curly brace ('{'). -->
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="RightCurly">
+            <!-- Checks right curlies on CATCH, ELSE, and TRY blocks are on
+            the same line. e.g., the following example is fine:
+            <pre>
+              if {
+                ...
+              } else
+            </pre>
+            -->
+            <!-- This next example is not fine:
+            <pre>
+              if {
+                ...
+              }
+              else
+            </pre>
+            -->
+            <property name="option" value="same"/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <!-- Checks for braces around if and else blocks -->
+        <module name="NeedBraces">
+            <property name="severity" value="warning"/>
+            <property name="tokens" value="LITERAL_IF, LITERAL_ELSE, LITERAL_FOR, LITERAL_WHILE, LITERAL_DO"/>
+        </module>
+
+        <module name="UpperEll">
+            <!-- Checks that long constants are defined with an upper ell.-->
+            <property name="severity" value="error"/>
+        </module>
+
+        <module name="FallThrough">
+            <!-- Warn about falling through to the next case statement.  Similar to
+            javac -Xlint:fallthrough, but the check is suppressed if a single-line comment
+            on the last non-blank line preceding the fallen-into case contains 'fall through' (or
+            some other variants which we don't publicized to promote consistency).
+            -->
+            <property name="reliefPattern"
+                      value="fall through|Fall through|fallthru|Fallthru|falls through|Falls through|fallthrough|Fallthrough|No break|NO break|no break|continue on"/>
+            <property name="severity" value="error"/>
+        </module>
+
+
+        <!--
+
+        MODIFIERS CHECKS
+
+        -->
+
+        <module name="ModifierOrder">
+            <!-- Warn if modifier order is inconsistent with JLS3 8.1.1, 8.3.1, and
+                 8.4.3.  The prescribed order is:
+                 public, protected, private, abstract, static, final, transient, volatile,
+                 synchronized, native, strictfp
+              -->
+        </module>
+
+
+        <!--
+
+        WHITESPACE CHECKS
+
+        -->
+
+        <module name="WhitespaceAround">
+            <!-- Checks that various tokens are surrounded by whitespace.
+                 This includes most binary operators and keywords followed
+                 by regular or curly braces.
+            -->
+            <property name="tokens" value="ASSIGN, BAND, BAND_ASSIGN, BOR,
+        BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR, BXOR_ASSIGN, COLON, DIV, DIV_ASSIGN,
+        EQUAL, GE, GT, LAND, LE, LITERAL_CATCH, LITERAL_DO, LITERAL_ELSE,
+        LITERAL_FINALLY, LITERAL_FOR, LITERAL_IF, LITERAL_RETURN,
+        LITERAL_SYNCHRONIZED, LITERAL_TRY, LITERAL_WHILE, LOR, LT, MINUS,
+        MINUS_ASSIGN, MOD, MOD_ASSIGN, NOT_EQUAL, PLUS, PLUS_ASSIGN, QUESTION,
+        SL, SL_ASSIGN, SR_ASSIGN, STAR, STAR_ASSIGN"/>
+            <property name="severity" value="error"/>
+        </module>
+
+        <module name="WhitespaceAfter">
+            <!-- Checks that commas, semicolons and typecasts are followed by
+                 whitespace.
+            -->
+            <property name="tokens" value="COMMA, SEMI, TYPECAST"/>
+        </module>
+
+        <module name="NoWhitespaceAfter">
+            <!-- Checks that there is no whitespace after various unary operators.
+                 Linebreaks are allowed.
+            -->
+            <property name="tokens" value="BNOT, DEC, DOT, INC, LNOT, UNARY_MINUS,
+        UNARY_PLUS"/>
+            <property name="allowLineBreaks" value="true"/>
+            <property name="severity" value="error"/>
+        </module>
+
+        <module name="NoWhitespaceBefore">
+            <!-- Checks that there is no whitespace before various unary operators.
+                 Linebreaks are allowed.
+            -->
+            <property name="tokens" value="SEMI, DOT, POST_DEC, POST_INC"/>
+            <property name="allowLineBreaks" value="true"/>
+            <property name="severity" value="error"/>
+        </module>
+
+        <module name="ParenPad">
+            <!-- Checks that there is no whitespace before close parens or after
+                 open parens.
+            -->
+            <property name="severity" value="warning"/>
+        </module>
+
+    </module>
+
+    <module name="LineLength">
+        <!-- Checks if a line is too long. -->
+        <property name="max" value="${com.puppycrawl.tools.checkstyle.checks.sizes.LineLength.max}" default="128"/>
+        <property name="severity" value="error"/>
+
+        <!--
+          The default ignore pattern exempts the following elements:
+            - import statements
+            - long URLs inside comments
+        -->
+
+        <property name="ignorePattern"
+                  value="${com.puppycrawl.tools.checkstyle.checks.sizes.LineLength.ignorePattern}"
+                  default="^(package .*;\s*)|(import .*;\s*)|( *(\*|//).*https?://.*)$"/>
+    </module>
+</module>
+

gradle/quality/cyclonedx.gradle

@@ -0,0 +1,11 @@
+cyclonedxBom {
+    includeConfigs = [ 'runtimeClasspath' ]
+    skipConfigs = [ 'compileClasspath', 'testCompileClasspath' ]
+    projectType = "library"
+    schemaVersion = "1.4"
+    destination = file("build/reports")
+    outputName = "bom"
+    outputFormat = "json"
+    includeBomSerialNumber = true
+    componentVersion = "2.0.0"
+}

gradle/quality/pmd.gradle

@@ -0,0 +1,17 @@
+
+apply plugin: 'pmd'
+
+tasks.withType(Pmd) {
+    ignoreFailures = true
+    reports {
+        xml.getRequired().set(true)
+        html.getRequired().set(true)
+    }
+}
+
+pmd {
+    ignoreFailures = true
+    consoleOutput = false
+    toolVersion = "6.51.0"
+    ruleSetFiles = rootProject.files('gradle/quality/pmd/category/java/bestpractices.xml')
+}

gradle/quality/pmd/category/java/categories.properties

@@ -0,0 +1,10 @@
+
+rulesets.filenames=\
+    category/java/bestpractices.xml,\
+    category/java/codestyle.xml,\
+    category/java/design.xml,\
+    category/java/documentation.xml,\
+    category/java/errorprone.xml,\
+    category/java/multithreading.xml,\
+    category/java/performance.xml,\
+    category/java/security.xml

gradle/quality/pmd/category/java/documentation.xml

@@ -0,0 +1,144 @@
+<?xml version="1.0"?>
+
+<ruleset name="Documentation"
+         xmlns="http://pmd.sourceforge.net/ruleset/2.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://pmd.sourceforge.net/ruleset/2.0.0 https://pmd.sourceforge.io/ruleset_2_0_0.xsd">
+
+    <description>
+        Rules that are related to code documentation.
+    </description>
+
+    <rule name="CommentContent"
+          since="5.0"
+          message="Invalid words or phrases found"
+          class="net.sourceforge.pmd.lang.java.rule.documentation.CommentContentRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_documentation.html#commentcontent">
+        <description>
+            A rule for the politically correct... we don't want to offend anyone.
+        </description>
+        <priority>3</priority>
+        <example>
+            <![CDATA[
+//OMG, this is horrible, Bob is an idiot !!!
+]]>
+        </example>
+    </rule>
+
+    <rule name="CommentRequired"
+          since="5.1"
+          message="Comment is required"
+          class="net.sourceforge.pmd.lang.java.rule.documentation.CommentRequiredRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_documentation.html#commentrequired">
+        <description>
+            Denotes whether comments are required (or unwanted) for specific language elements.
+        </description>
+        <priority>3</priority>
+        <example>
+            <![CDATA[
+/**
+*
+*
+* @author Jon Doe
+*/
+]]>
+        </example>
+    </rule>
+
+    <rule name="CommentSize"
+          since="5.0"
+          message="Comment is too large"
+          class="net.sourceforge.pmd.lang.java.rule.documentation.CommentSizeRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_documentation.html#commentsize">
+        <description>
+            Determines whether the dimensions of non-header comments found are within the specified limits.
+        </description>
+        <priority>3</priority>
+        <example>
+            <![CDATA[
+/**
+*
+*   too many lines!
+*
+*
+*
+*
+*
+*
+*
+*
+*
+*
+*
+*
+*/
+]]>
+        </example>
+    </rule>
+
+    <rule name="UncommentedEmptyConstructor"
+          language="java"
+          since="3.4"
+          message="Document empty constructor"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          typeResolution="true"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_documentation.html#uncommentedemptyconstructor">
+        <description>
+            Uncommented Empty Constructor finds instances where a constructor does not
+            contain statements, but there is no comment. By explicitly commenting empty
+            constructors it is easier to distinguish between intentional (commented)
+            and unintentional empty constructors.
+        </description>
+        <priority>3</priority>
+        <properties>
+            <property name="xpath">
+                <value>
+                    <![CDATA[
+//ConstructorDeclaration[@Private='false']
+                        [count(BlockStatement) = 0 and ($ignoreExplicitConstructorInvocation = 'true' or not(ExplicitConstructorInvocation)) and @containsComment = 'false']
+                        [not(../Annotation/MarkerAnnotation/Name[pmd-java:typeIs('javax.inject.Inject')])]
+]]>
+                </value>
+            </property>
+            <property name="ignoreExplicitConstructorInvocation" type="Boolean" description="Ignore explicit constructor invocation when deciding whether constructor is empty or not" value="false"/>
+        </properties>
+        <example>
+            <![CDATA[
+public Foo() {
+  // This constructor is intentionally empty. Nothing special is needed here.
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="UncommentedEmptyMethodBody"
+          language="java"
+          since="3.4"
+          message="Document empty method body"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_documentation.html#uncommentedemptymethodbody">
+        <description>
+            Uncommented Empty Method Body finds instances where a method body does not contain
+            statements, but there is no comment. By explicitly commenting empty method bodies
+            it is easier to distinguish between intentional (commented) and unintentional
+            empty methods.
+        </description>
+        <priority>3</priority>
+        <properties>
+            <property name="xpath">
+                <value>
+                    <![CDATA[
+//MethodDeclaration/Block[count(BlockStatement) = 0 and @containsComment = 'false']
+]]>
+                </value>
+            </property>
+        </properties>
+        <example>
+            <![CDATA[
+public void doSomething() {
+}
+]]>
+        </example>
+    </rule>
+
+</ruleset>

gradle/quality/pmd/category/java/multithreading.xml

@@ -0,0 +1,393 @@
+<?xml version="1.0"?>
+
+<ruleset name="Multithreading"
+         xmlns="http://pmd.sourceforge.net/ruleset/2.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://pmd.sourceforge.net/ruleset/2.0.0 https://pmd.sourceforge.io/ruleset_2_0_0.xsd">
+
+    <description>
+        Rules that flag issues when dealing with multiple threads of execution.
+    </description>
+
+    <rule name="AvoidSynchronizedAtMethodLevel"
+          language="java"
+          since="3.0"
+          message="Use block level rather than method level synchronization"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#avoidsynchronizedatmethodlevel">
+        <description>
+            Method-level synchronization can cause problems when new code is added to the method.
+            Block-level synchronization helps to ensure that only the code that needs synchronization
+            gets it.
+        </description>
+        <priority>3</priority>
+        <properties>
+            <property name="xpath">
+                <value>//MethodDeclaration[@Synchronized='true']</value>
+            </property>
+        </properties>
+        <example>
+            <![CDATA[
+public class Foo {
+  // Try to avoid this:
+  synchronized void foo() {
+  }
+  // Prefer this:
+  void bar() {
+    synchronized(this) {
+    }
+  }
+
+  // Try to avoid this for static methods:
+  static synchronized void fooStatic() {
+  }
+
+  // Prefer this:
+  static void barStatic() {
+    synchronized(Foo.class) {
+    }
+  }
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="AvoidThreadGroup"
+          language="java"
+          since="3.6"
+          message="Avoid using java.lang.ThreadGroup; it is not thread safe"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          typeResolution="true"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#avoidthreadgroup">
+        <description>
+            Avoid using java.lang.ThreadGroup; although it is intended to be used in a threaded environment
+            it contains methods that are not thread-safe.
+        </description>
+        <priority>3</priority>
+        <properties>
+            <property name="xpath">
+                <value>
+                    <![CDATA[
+//AllocationExpression/ClassOrInterfaceType[pmd-java:typeIs('java.lang.ThreadGroup')]|
+//PrimarySuffix[contains(@Image, 'getThreadGroup')]
+]]>
+                </value>
+            </property>
+        </properties>
+        <example>
+            <![CDATA[
+public class Bar {
+    void buz() {
+        ThreadGroup tg = new ThreadGroup("My threadgroup");
+        tg = new ThreadGroup(tg, "my thread group");
+        tg = Thread.currentThread().getThreadGroup();
+        tg = System.getSecurityManager().getThreadGroup();
+    }
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="AvoidUsingVolatile"
+          language="java"
+          since="4.1"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          message="Use of modifier volatile is not recommended."
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#avoidusingvolatile">
+        <description>
+            Use of the keyword 'volatile' is generally used to fine tune a Java application, and therefore, requires
+            a good expertise of the Java Memory Model. Moreover, its range of action is somewhat misknown. Therefore,
+            the volatile keyword should not be used for maintenance purpose and portability.
+        </description>
+        <priority>2</priority>
+        <properties>
+            <property name="xpath">
+                <value>//FieldDeclaration[contains(@Volatile,'true')]</value>
+            </property>
+        </properties>
+        <example>
+            <![CDATA[
+public class ThrDeux {
+  private volatile String var1; // not suggested
+  private          String var2; // preferred
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="DoNotUseThreads"
+          language="java"
+          since="4.1"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          message="To be compliant to J2EE, a webapp should not use any thread."
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#donotusethreads">
+        <description>
+            The J2EE specification explicitly forbids the use of threads.
+        </description>
+        <priority>3</priority>
+        <properties>
+            <property name="xpath">
+                <value>//ClassOrInterfaceType[@Image = 'Thread' or @Image = 'Runnable']</value>
+            </property>
+        </properties>
+        <example>
+            <![CDATA[
+// This is not allowed
+public class UsingThread extends Thread {
+
+}
+
+// Neither this,
+public class OtherThread implements Runnable {
+    // Nor this ...
+    public void methode() {
+        Runnable thread = new Thread(); thread.run();
+    }
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="DontCallThreadRun"
+          language="java"
+          since="4.3"
+          message="Don't call Thread.run() explicitly, use Thread.start()"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          typeResolution="true"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#dontcallthreadrun">
+        <description>
+            Explicitly calling Thread.run() method will execute in the caller's thread of control.  Instead, call Thread.start() for the intended behavior.
+        </description>
+        <priority>4</priority>
+        <properties>
+            <property name="xpath">
+                <value>
+                    <![CDATA[
+//StatementExpression/PrimaryExpression
+[
+    PrimaryPrefix
+    [
+        ./Name[ends-with(@Image, '.run') or @Image = 'run']
+        and substring-before(Name/@Image, '.') =//VariableDeclarator/VariableDeclaratorId/@Image
+            [../../../Type/ReferenceType/ClassOrInterfaceType[pmd-java:typeIs('java.lang.Thread')]]
+        or (./AllocationExpression/ClassOrInterfaceType[pmd-java:typeIs('java.lang.Thread')]
+        and ../PrimarySuffix[@Image = 'run'])
+    ]
+]
+]]>
+                </value>
+            </property>
+        </properties>
+        <example>
+            <![CDATA[
+Thread t = new Thread();
+t.run();            // use t.start() instead
+new Thread().run(); // same violation
+]]>
+        </example>
+    </rule>
+
+    <rule name="DoubleCheckedLocking"
+          language="java"
+          since="1.04"
+          message="Double checked locking is not thread safe in Java."
+          class="net.sourceforge.pmd.lang.java.rule.multithreading.DoubleCheckedLockingRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#doublecheckedlocking">
+        <description>
+            Partially created objects can be returned by the Double Checked Locking pattern when used in Java.
+            An optimizing JRE may assign a reference to the baz variable before it calls the constructor of the object the
+            reference points to.
+
+            Note: With Java 5, you can make Double checked locking work, if you declare the variable to be `volatile`.
+
+            For more details refer to: &lt;http://www.javaworld.com/javaworld/jw-02-2001/jw-0209-double.html>
+            or &lt;http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html>
+        </description>
+        <priority>1</priority>
+        <example>
+            <![CDATA[
+public class Foo {
+    /*volatile */ Object baz = null; // fix for Java5 and later: volatile
+    Object bar() {
+        if (baz == null) { // baz may be non-null yet not fully created
+            synchronized(this) {
+                if (baz == null) {
+                    baz = new Object();
+                }
+              }
+        }
+        return baz;
+    }
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="NonThreadSafeSingleton"
+          since="3.4"
+          message="Singleton is not thread safe"
+          class="net.sourceforge.pmd.lang.java.rule.multithreading.NonThreadSafeSingletonRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#nonthreadsafesingleton">
+        <description>
+            Non-thread safe singletons can result in bad state changes. Eliminate
+            static singletons if possible by instantiating the object directly. Static
+            singletons are usually not needed as only a single instance exists anyway.
+            Other possible fixes are to synchronize the entire method or to use an
+            [initialize-on-demand holder class](https://en.wikipedia.org/wiki/Initialization-on-demand_holder_idiom).
+
+            Refrain from using the double-checked locking pattern. The Java Memory Model doesn't
+            guarantee it to work unless the variable is declared as `volatile`, adding an uneeded
+            performance penalty. [Reference](http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html)
+
+            See Effective Java, item 48.
+        </description>
+        <priority>3</priority>
+        <example>
+            <![CDATA[
+private static Foo foo = null;
+
+//multiple simultaneous callers may see partially initialized objects
+public static Foo getFoo() {
+    if (foo==null) {
+        foo = new Foo();
+    }
+    return foo;
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="UnsynchronizedStaticDateFormatter"
+          since="3.6"
+          deprecated="true"
+          message="Static DateFormatter objects should be accessed in a synchronized manner"
+          class="net.sourceforge.pmd.lang.java.rule.multithreading.UnsynchronizedStaticDateFormatterRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#unsynchronizedstaticdateformatter">
+        <description>
+            SimpleDateFormat instances are not synchronized. Sun recommends using separate format instances
+            for each thread. If multiple threads must access a static formatter, the formatter must be
+            synchronized either on method or block level.
+
+            This rule has been deprecated in favor of the rule {% rule UnsynchronizedStaticFormatter %}.
+        </description>
+        <priority>3</priority>
+        <example>
+            <![CDATA[
+public class Foo {
+    private static final SimpleDateFormat sdf = new SimpleDateFormat();
+    void bar() {
+        sdf.format(); // poor, no thread-safety
+    }
+    synchronized void foo() {
+        sdf.format(); // preferred
+    }
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="UnsynchronizedStaticFormatter"
+          since="6.11.0"
+          message="Static Formatter objects should be accessed in a synchronized manner"
+          class="net.sourceforge.pmd.lang.java.rule.multithreading.UnsynchronizedStaticFormatterRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#unsynchronizedstaticformatter">
+        <description>
+            Instances of `java.text.Format` are generally not synchronized.
+            Sun recommends using separate format instances for each thread.
+            If multiple threads must access a static formatter, the formatter must be
+            synchronized either on method or block level.
+        </description>
+        <priority>3</priority>
+        <example>
+            <![CDATA[
+public class Foo {
+    private static final SimpleDateFormat sdf = new SimpleDateFormat();
+    void bar() {
+        sdf.format(); // poor, no thread-safety
+    }
+    synchronized void foo() {
+        sdf.format(); // preferred
+    }
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="UseConcurrentHashMap"
+          language="java"
+          minimumLanguageVersion="1.5"
+          since="4.2.6"
+          message="If you run in Java5 or newer and have concurrent access, you should use the ConcurrentHashMap implementation"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#useconcurrenthashmap">
+        <description>
+            Since Java5 brought a new implementation of the Map designed for multi-threaded access, you can
+            perform efficient map reads without blocking other threads.
+        </description>
+        <priority>3</priority>
+        <properties>
+            <property name="xpath">
+                <value>
+                    <![CDATA[
+//Type[../VariableDeclarator/VariableInitializer//AllocationExpression/ClassOrInterfaceType[@Image != 'ConcurrentHashMap']]
+/ReferenceType/ClassOrInterfaceType[@Image = 'Map']
+]]>
+                </value>
+            </property>
+        </properties>
+        <example>
+            <![CDATA[
+public class ConcurrentApp {
+  public void getMyInstance() {
+    Map map1 = new HashMap();           // fine for single-threaded access
+    Map map2 = new ConcurrentHashMap(); // preferred for use with multiple threads
+
+    // the following case will be ignored by this rule
+    Map map3 = someModule.methodThatReturnMap(); // might be OK, if the returned map is already thread-safe
+  }
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="UseNotifyAllInsteadOfNotify"
+          language="java"
+          since="3.0"
+          message="Call Thread.notifyAll() rather than Thread.notify()"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#usenotifyallinsteadofnotify">
+        <description>
+            Thread.notify() awakens a thread monitoring the object. If more than one thread is monitoring, then only
+            one is chosen.  The thread chosen is arbitrary; thus its usually safer to call notifyAll() instead.
+        </description>
+        <priority>3</priority>
+        <properties>
+            <property name="xpath">
+                <value>
+                    <![CDATA[
+//StatementExpression/PrimaryExpression
+[PrimarySuffix/Arguments[@ArgumentCount = '0']]
+[
+    PrimaryPrefix[
+        ./Name[@Image='notify' or ends-with(@Image,'.notify')]
+        or ../PrimarySuffix/@Image='notify'
+        or (./AllocationExpression and ../PrimarySuffix[@Image='notify'])
+    ]
+]
+]]>
+                </value>
+            </property>
+        </properties>
+        <example>
+            <![CDATA[
+  void bar() {
+    x.notify();
+    // If many threads are monitoring x, only one (and you won't know which) will be notified.
+    // use instead:
+    x.notifyAll();
+  }
+]]>
+        </example>
+    </rule>
+
+</ruleset>

gradle/quality/pmd/category/java/security.xml

@@ -0,0 +1,65 @@
+<?xml version="1.0"?>
+
+<ruleset name="Security" xmlns="http://pmd.sourceforge.net/ruleset/2.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://pmd.sourceforge.net/ruleset/2.0.0 https://pmd.sourceforge.io/ruleset_2_0_0.xsd">
+
+    <description>
+        Rules that flag potential security flaws.
+    </description>
+
+    <rule name="HardCodedCryptoKey"
+          since="6.4.0"
+          message="Do not use hard coded encryption keys"
+          class="net.sourceforge.pmd.lang.java.rule.security.HardCodedCryptoKeyRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_security.html#hardcodedcryptokey">
+        <description>
+            Do not use hard coded values for cryptographic operations. Please store keys outside of source code.
+        </description>
+        <priority>3</priority>
+        <example>
+            <![CDATA[
+public class Foo {
+    void good() {
+        SecretKeySpec secretKeySpec = new SecretKeySpec(Properties.getKey(), "AES");
+    }
+
+    void bad() {
+        SecretKeySpec secretKeySpec = new SecretKeySpec("my secret here".getBytes(), "AES");
+    }
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="InsecureCryptoIv"
+          since="6.3.0"
+          message="Do not use hard coded initialization vector in crypto operations"
+          class="net.sourceforge.pmd.lang.java.rule.security.InsecureCryptoIvRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_security.html#insecurecryptoiv">
+        <description>
+            Do not use hard coded initialization vector in cryptographic operations. Please use a randomly generated IV.
+        </description>
+        <priority>3</priority>
+        <example>
+            <![CDATA[
+public class Foo {
+    void good() {
+        SecureRandom random = new SecureRandom();
+        byte iv[] = new byte[16];
+        random.nextBytes(bytes);
+    }
+
+    void bad() {
+        byte[] iv = new byte[] { 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, };
+    }
+
+    void alsoBad() {
+        byte[] iv = "secret iv in here".getBytes();
+    }
+}
+]]>
+        </example>
+    </rule>
+
+</ruleset>

gradle/quality/sonarqube.gradle

@@ -0,0 +1,37 @@
+
+subprojects {
+
+    sonarqube {
+        properties {
+            property "sonar.projectName", "${project.group} ${project.name}"
+            property "sonar.sourceEncoding", "UTF-8"
+            property "sonar.tests", "src/test/java"
+            property "sonar.scm.provider", "git"
+            property "sonar.junit.reportsPath", "build/test-results/test/"
+        }
+    }
+
+
+    tasks.withType(Pmd) {
+        ignoreFailures = true
+        reports {
+            xml.enabled = true
+            html.enabled = true
+        }
+    }
+
+
+    spotbugs {
+        effort = "max"
+        reportLevel = "low"
+        //includeFilter = file("findbugs-exclude.xml")
+    }
+
+    tasks.withType(com.github.spotbugs.SpotBugsTask) {
+        ignoreFailures = true
+        reports {
+            xml.enabled = false
+            html.enabled = true
+        }
+    }
+}

gradle/quality/spotbugs.gradle

@@ -0,0 +1,15 @@
+
+apply plugin: 'com.github.spotbugs'
+
+spotbugs {
+    effort = "max"
+    reportLevel = "low"
+    ignoreFailures = true
+}
+
+spotbugsMain {
+    reports {
+        xml.getRequired().set(false)
+        html.getRequired().set(true)
+    }
+}

gradle/repositories/maven.gradle

@@ -0,0 +1,4 @@
+repositories {
+    mavenLocal()
+    mavenCentral()
+}

gradle/test/junit5.gradle

@@ -0,0 +1,28 @@
+
+def junitVersion = project.hasProperty('junit.version')?project.property('junit.version'):'5.7.1'
+def hamcrestVersion = project.hasProperty('hamcrest.version')?project.property('hamcrest.version'):'2.2'
+
+dependencies {
+    testImplementation "org.junit.jupiter:junit-jupiter-api:${junitVersion}"
+    testImplementation "org.junit.jupiter:junit-jupiter-params:${junitVersion}"
+    testImplementation "org.hamcrest:hamcrest-library:${hamcrestVersion}"
+    testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:${junitVersion}"
+    testRuntimeOnly "org.junit.vintage:junit-vintage-engine:${junitVersion}"
+}
+
+test {
+    useJUnitPlatform()
+    failFast = false
+    testLogging {
+        events 'STARTED', 'PASSED', 'FAILED', 'SKIPPED'
+    }
+    afterSuite { desc, result ->
+        if (!desc.parent) {
+            println "\nTest result: ${result.resultType}"
+            println "Test summary: ${result.testCount} tests, " +
+                    "${result.successfulTestCount} succeeded, " +
+                    "${result.failedTestCount} failed, " +
+                    "${result.skippedTestCount} skipped"
+        }
+    }
+}

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,6 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.1.1-all.zip
+networkTimeout=10000
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

gradlew

@@ -0,0 +1,245 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/HEAD/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command;
+#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
+#     shell script including quotes and variable substitutions, so put them in
+#     double quotes to make sure that they get re-expanded; and
+#   * put everything else in single quotes, so that it's not re-expanded.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"

gradlew.bat

@@ -0,0 +1,92 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if %ERRORLEVEL% equ 0 goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

settings.gradle

@@ -1 +1,49 @@
-rootProject.name = 'guice'
+pluginManagement {
+    repositories {
+        mavenLocal()
+        mavenCentral {
+            metadataSources {
+                mavenPom()
+                artifact()
+                ignoreGradleMetadataRedirection()
+            }
+        }
+        gradlePluginPortal()
+    }
+}
+
+dependencyResolutionManagement {
+    versionCatalogs {
+        libs {
+            version('gradle', '8.1.1')
+            version('groovy', '3.0.10')
+            version('junit', '5.9.2')
+            library('junit-jupiter-api', 'org.junit.jupiter', 'junit-jupiter-api').versionRef('junit')
+            library('junit-jupiter-params', 'org.junit.jupiter', 'junit-jupiter-params').versionRef('junit')
+            library('junit-jupiter-engine', 'org.junit.jupiter', 'junit-jupiter-engine').versionRef('junit')
+            library('hamcrest', 'org.hamcrest', 'hamcrest-library').version('2.2')
+            library('junit4', 'junit', 'junit').version('4.13.2')
+            library('javax.inject', 'org.xbib', 'javax-inject').version('1')
+            library('guava', 'org.xbib', 'guava').version('30.1')
+            library('guava.testlib', 'com.google.guava', 'guava-testlib').version('30.1-jre')
+        }
+    }
+}
+
+/*
+gradle.wrapper.version = 6.6.1
+javax-inject.version = 1
+guava.version = 30.1
+# test
+junit.version = 5.7.2
+junit4.version = 4.13.2
+log4j.version = 2.14.1
+
+    api "org.xbib:javax-inject:${project.property('javax-inject.version')}"
+    api "org.xbib:guava:${project.property('guava.version')}"
+    testImplementation "junit:junit:${project.property('junit4.version')}"
+    // Helper for com.google.common.testing.GcFinalization, com.google.common.testing.EqualsTester
+    testImplementation "com.google.guava:guava-testlib:30.1-jre"
+
+
+ */

src/main/java/com/google/inject/AbstractModule.java

@@ -36,6 +36,7 @@ public abstract class AbstractModule implements Module {
 
     Binder binder;
 
+    @Override
     public final synchronized void configure(Binder builder) {
         checkState(this.binder == null, "Re-entry is not allowed.");
 
@@ -63,8 +64,7 @@ public abstract class AbstractModule implements Module {
     /**
      * @see Binder#bindScope(Class, Scope)
      */
-    protected void bindScope(Class<? extends Annotation> scopeAnnotation,
-                             Scope scope) {
+    protected void bindScope(Class<? extends Annotation> scopeAnnotation, Scope scope) {
         binder().bindScope(scopeAnnotation, scope);
     }
 

src/main/java/com/google/inject/Binder.java

@@ -100,7 +100,7 @@ import java.lang.reflect.Proxy;
  * contribute their own custom scopes for use here as well.
  *
  * <pre>
- *     bind(new TypeLiteral&lt;PaymentService&lt;CreditCard>>() {})
+ *     bind(new TypeLiteral&lt;PaymentService&lt;CreditCard&gt;&gt;() {})
  *         .to(CreditCardPaymentService.class);</pre>
  *
  * This admittedly odd construct is the way to bind a parameterized type. It
@@ -159,7 +159,7 @@ import java.lang.reflect.Proxy;
  * your application.
  *
  * <pre>
- *     Constructor<T> loneCtor = getLoneCtorFromServiceImplViaReflection();
+ *     Constructor&lt;T&gt; loneCtor = getLoneCtorFromServiceImplViaReflection();
  *     bind(ServiceImpl.class)
  *         .toConstructor(loneCtor);</pre>
  *
@@ -367,7 +367,7 @@ public interface Binder {
      *                      their clients.
      * @return a binder that shares its configuration with this binder.
      */
-    Binder skipSources(Class... classesToSkip);
+    Binder skipSources(Class<?>... classesToSkip);
 
     /**
      * Creates a new private child environment for bindings and other configuration. The returned

src/main/java/com/google/inject/ConfigurationException.java

@@ -1,7 +1,7 @@
 package com.google.inject;
 
 import com.google.common.collect.ImmutableSet;
-import com.google.inject.internal.Errors;
+import com.google.inject.internal.Messages;
 import com.google.inject.spi.Message;
 
 import java.util.Collection;
@@ -24,7 +24,7 @@ public final class ConfigurationException extends RuntimeException {
      */
     public ConfigurationException(Iterable<Message> messages) {
         this.messages = ImmutableSet.copyOf(messages);
-        initCause(Errors.getOnlyCause(this.messages));
+        initCause(Messages.getOnlyCause(this.messages));
     }
 
     /**
@@ -59,6 +59,6 @@ public final class ConfigurationException extends RuntimeException {
 
     @Override
     public String getMessage() {
-        return Errors.format("Guice configuration errors", messages);
+        return Messages.formatMessages("Guice configuration errors", messages);
     }
 }

src/main/java/com/google/inject/CreationException.java

@@ -1,7 +1,7 @@
 package com.google.inject;
 
 import com.google.common.collect.ImmutableSet;
-import com.google.inject.internal.Errors;
+import com.google.inject.internal.Messages;
 import com.google.inject.spi.Message;
 
 import java.util.Collection;
@@ -12,9 +12,9 @@ import static com.google.common.base.Preconditions.checkArgument;
  * Thrown when errors occur while creating a {@link Injector}. Includes a list of encountered
  * errors. Clients should catch this exception, log it, and stop execution.
  */
+@SuppressWarnings("serial")
 public class CreationException extends RuntimeException {
 
-    private static final long serialVersionUID = 0;
     private final ImmutableSet<Message> messages;
 
     /**
@@ -23,7 +23,7 @@ public class CreationException extends RuntimeException {
     public CreationException(Collection<Message> messages) {
         this.messages = ImmutableSet.copyOf(messages);
         checkArgument(!this.messages.isEmpty());
-        initCause(Errors.getOnlyCause(this.messages));
+        initCause(Messages.getOnlyCause(this.messages));
     }
 
     /**
@@ -35,6 +35,6 @@ public class CreationException extends RuntimeException {
 
     @Override
     public String getMessage() {
-        return Errors.format("Unable to create injector, see the following errors", messages);
+        return Messages.formatMessages("Unable to create injector, see the following errors", messages);
     }
 }

src/main/java/com/google/inject/Guice.java

@@ -76,11 +76,7 @@ public final class Guice {
      * @throws CreationException if one or more errors occur during injector
      *                           construction
      */
-    public static Injector createInjector(Stage stage,
-                                          Iterable<? extends Module> modules) {
-        return new InternalInjectorCreator()
-                .stage(stage)
-                .addModules(modules)
-                .build();
+    public static Injector createInjector(Stage stage, Iterable<? extends Module> modules) {
+        return new InternalInjectorCreator().stage(stage).addModules(modules).build();
     }
 }

src/main/java/com/google/inject/Injector.java

@@ -1,5 +1,7 @@
 package com.google.inject;
 
+import com.google.inject.spi.Element;
+import com.google.inject.spi.InjectionPoint;
 import com.google.inject.spi.TypeConverterBinding;
 
 import java.lang.annotation.Annotation;
@@ -225,4 +227,37 @@ public interface Injector {
      * <p>This method is part of the Guice SPI and is intended for use by tools and extensions.
      */
     Set<TypeConverterBinding> getTypeConverterBindings();
+
+
+    /**
+     * Returns the elements that make up this injector. Note that not all kinds of elements are
+     * returned.
+     *
+     * <p>The returned list does not include elements inherited from a {@link #getParent() parent
+     * injector}, should one exist.
+     *
+     * <p>The returned list is immutable; it contains only the elements that were present when {@link
+     * #getElements} was invoked. Subsequent calls may return a list with additional elements.
+     *
+     * <p>The returned list does not include data inherited from a {@link #getParent() parent
+     * injector}, should one exist.
+     *
+     * <p>This method is part of the Guice SPI and is intended for use by tools and extensions.
+     */
+    List<Element> getElements();
+
+    /**
+     * Returns the injection points created for calls to {@link #getMembersInjector} (either directly
+     * or indirectly, e.g. through {@link #injectMembers}.
+     *
+     * <p>This excludes any injection points from elements (which are accessible from each element via
+     * the SPI), unless {@link #getMembersInjector} or {@link #injectMembers} were also called for the
+     * same key.
+     *
+     * <p>The returned multimap does not include data inherited from a {@link #getParent() parent
+     * injector}, should one exist.
+     *
+     * <p>This method is part of the Guice SPI and is intended for use by tools and extensions.
+     */
+    Map<TypeLiteral<?>, List<InjectionPoint>> getAllMembersInjectorInjectionPoints();
 }

src/main/java/com/google/inject/Key.java

@@ -1,24 +1,20 @@
 package com.google.inject;
 
-import com.google.common.base.Supplier;
-import com.google.common.base.Suppliers;
-import com.google.inject.internal.Annotations;
-import com.google.inject.internal.MoreTypes;
-
-import java.lang.annotation.Annotation;
-import java.lang.reflect.Type;
-
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.inject.internal.Annotations.generateAnnotation;
 import static com.google.inject.internal.Annotations.isAllDefaultMethods;
 
+import com.google.inject.internal.Annotations;
+import com.google.inject.internal.MoreTypes;
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Type;
+
 /**
- * Binding key consisting of an injection type and an optional annotation.
- * Matches the type and annotation at a point of injection.
+ * Guice uses Key objects to identify a dependency that can be resolved by the Guice {@link
+ * Injector}. A Guice key consists of an injection type and an optional annotation.
  *
- * <p>For example, {@code Key.get(Service.class, Transactional.class)} will
- * match:
+ * <p>For example, {@code Key.get(Service.class, Transactional.class)} will match:
  *
  * <pre>
  *   {@literal @}Inject
@@ -27,12 +23,13 @@ import static com.google.inject.internal.Annotations.isAllDefaultMethods;
  *   }
  * </pre>
  *
- * <p>{@code Key} supports generic types via subclassing just like {@link
- * TypeLiteral}.
+ * <p>{@code Key} supports generic types via subclassing just like {@link TypeLiteral}.
  *
- * <p>Keys do not differentiate between primitive types (int, char, etc.) and
- * their corresponding wrapper types (Integer, Character, etc.). Primitive
- * types will be replaced with their wrapper types when keys are created.
+ * <p>Keys do not differentiate between primitive types (int, char, etc.) and their corresponding
+ * wrapper types (Integer, Character, etc.). Primitive types will be replaced with their wrapper
+ * types when keys are created.
+ *
+ * @author crazybob@google.com (Bob Lee)
  */
 public class Key<T> {
 
@@ -40,38 +37,37 @@ public class Key<T> {
 
     private final TypeLiteral<T> typeLiteral;
     private final int hashCode;
-    private final Supplier<String> toStringSupplier;
+    // This field is updated using the 'Data-Race-Ful' lazy intialization pattern
+    // See http://jeremymanson.blogspot.com/2008/12/benign-data-races-in-java.html for a detailed
+    // explanation.
+    private String toString;
 
     /**
      * Constructs a new key. Derives the type from this class's type parameter.
      *
-     * <p>Clients create an empty anonymous subclass. Doing so embeds the type
-     * parameter in the anonymous class's type hierarchy so we can reconstitute it
-     * at runtime despite erasure.
+     * <p>Clients create an empty anonymous subclass. Doing so embeds the type parameter in the
+     * anonymous class's type hierarchy so we can reconstitute it at runtime despite erasure.
      *
-     * <p>Example usage for a binding of type {@code Foo} annotated with
-     * {@code @Bar}:
+     * <p>Example usage for a binding of type {@code Foo} annotated with {@code @Bar}:
      *
      * <p>{@code new Key<Foo>(Bar.class) {}}.
      */
     @SuppressWarnings("unchecked")
     protected Key(Class<? extends Annotation> annotationType) {
         this.annotationStrategy = strategyFor(annotationType);
-        this.typeLiteral = MoreTypes.canonicalizeForKey(
+        this.typeLiteral =
+                MoreTypes.canonicalizeForKey(
                         (TypeLiteral<T>) TypeLiteral.fromSuperclassTypeParameter(getClass()));
         this.hashCode = computeHashCode();
-        this.toStringSupplier = createToStringSupplier();
     }
 
     /**
      * Constructs a new key. Derives the type from this class's type parameter.
      *
-     * <p>Clients create an empty anonymous subclass. Doing so embeds the type
-     * parameter in the anonymous class's type hierarchy so we can reconstitute it
-     * at runtime despite erasure.
+     * <p>Clients create an empty anonymous subclass. Doing so embeds the type parameter in the
+     * anonymous class's type hierarchy so we can reconstitute it at runtime despite erasure.
      *
-     * <p>Example usage for a binding of type {@code Foo} annotated with
-     * {@code @Bar}:
+     * <p>Example usage for a binding of type {@code Foo} annotated with {@code @Bar}:
      *
      * <p>{@code new Key<Foo>(new Bar()) {}}.
      */
@@ -79,18 +75,17 @@ public class Key<T> {
     protected Key(Annotation annotation) {
         // no usages, not test-covered
         this.annotationStrategy = strategyFor(annotation);
-        this.typeLiteral = MoreTypes.canonicalizeForKey(
+        this.typeLiteral =
+                MoreTypes.canonicalizeForKey(
                         (TypeLiteral<T>) TypeLiteral.fromSuperclassTypeParameter(getClass()));
         this.hashCode = computeHashCode();
-        this.toStringSupplier = createToStringSupplier();
     }
 
     /**
      * Constructs a new key. Derives the type from this class's type parameter.
      *
-     * <p>Clients create an empty anonymous subclass. Doing so embeds the type
-     * parameter in the anonymous class's type hierarchy so we can reconstitute it
-     * at runtime despite erasure.
+     * <p>Clients create an empty anonymous subclass. Doing so embeds the type parameter in the
+     * anonymous class's type hierarchy so we can reconstitute it at runtime despite erasure.
      *
      * <p>Example usage for a binding of type {@code Foo}:
      *
@@ -99,191 +94,51 @@ public class Key<T> {
     @SuppressWarnings("unchecked")
     protected Key() {
         this.annotationStrategy = NullAnnotationStrategy.INSTANCE;
-        this.typeLiteral = MoreTypes.canonicalizeForKey(
+        this.typeLiteral =
+                MoreTypes.canonicalizeForKey(
                         (TypeLiteral<T>) TypeLiteral.fromSuperclassTypeParameter(getClass()));
         this.hashCode = computeHashCode();
-        this.toStringSupplier = createToStringSupplier();
     }
 
-    /**
-     * Unsafe. Constructs a key from a manually specified type.
-     */
+    /** Unsafe. Constructs a key from a manually specified type. */
     @SuppressWarnings("unchecked")
     private Key(Type type, AnnotationStrategy annotationStrategy) {
         this.annotationStrategy = annotationStrategy;
         this.typeLiteral = MoreTypes.canonicalizeForKey((TypeLiteral<T>) TypeLiteral.get(type));
         this.hashCode = computeHashCode();
-        this.toStringSupplier = createToStringSupplier();
     }
 
-    /**
-     * Constructs a key from a manually specified type.
-     */
+    /** Constructs a key from a manually specified type. */
     private Key(TypeLiteral<T> typeLiteral, AnnotationStrategy annotationStrategy) {
         this.annotationStrategy = annotationStrategy;
         this.typeLiteral = MoreTypes.canonicalizeForKey(typeLiteral);
         this.hashCode = computeHashCode();
-        this.toStringSupplier = createToStringSupplier();
     }
 
-    /**
-     * Gets a key for an injection type and an annotation strategy.
-     */
-    static <T> Key<T> get(Class<T> type,
-                          AnnotationStrategy annotationStrategy) {
-        return new Key<T>(type, annotationStrategy);
-    }
-
-    /**
-     * Gets a key for an injection type.
-     */
-    public static <T> Key<T> get(Class<T> type) {
-        return new Key<T>(type, NullAnnotationStrategy.INSTANCE);
-    }
-
-    /**
-     * Gets a key for an injection type and an annotation type.
-     */
-    public static <T> Key<T> get(Class<T> type,
-                                 Class<? extends Annotation> annotationType) {
-        return new Key<T>(type, strategyFor(annotationType));
-    }
-
-    /**
-     * Gets a key for an injection type and an annotation.
-     */
-    public static <T> Key<T> get(Class<T> type, Annotation annotation) {
-        return new Key<T>(type, strategyFor(annotation));
-    }
-
-    /**
-     * Gets a key for an injection type.
-     */
-    public static Key<?> get(Type type) {
-        return new Key<Object>(type, NullAnnotationStrategy.INSTANCE);
-    }
-
-    /**
-     * Gets a key for an injection type and an annotation type.
-     */
-    public static Key<?> get(Type type,
-                             Class<? extends Annotation> annotationType) {
-        return new Key<Object>(type, strategyFor(annotationType));
-    }
-
-    /**
-     * Gets a key for an injection type and an annotation.
-     */
-    public static Key<?> get(Type type, Annotation annotation) {
-        return new Key<Object>(type, strategyFor(annotation));
-    }
-
-    /**
-     * Gets a key for an injection type.
-     */
-    public static <T> Key<T> get(TypeLiteral<T> typeLiteral) {
-        return new Key<T>(typeLiteral, NullAnnotationStrategy.INSTANCE);
-    }
-
-    /**
-     * Gets a key for an injection type and an annotation type.
-     */
-    public static <T> Key<T> get(TypeLiteral<T> typeLiteral,
-                                 Class<? extends Annotation> annotationType) {
-        return new Key<T>(typeLiteral, strategyFor(annotationType));
-    }
-
-    /**
-     * Gets a key for an injection type and an annotation.
-     */
-    public static <T> Key<T> get(TypeLiteral<T> typeLiteral,
-                                 Annotation annotation) {
-        return new Key<T>(typeLiteral, strategyFor(annotation));
-    }
-
-    /**
-     * Gets the strategy for an annotation.
-     */
-    static AnnotationStrategy strategyFor(Annotation annotation) {
-        checkNotNull(annotation, "annotation");
-        Class<? extends Annotation> annotationType = annotation.annotationType();
-        ensureRetainedAtRuntime(annotationType);
-        ensureIsBindingAnnotation(annotationType);
-
-        if (Annotations.isMarker(annotationType)) {
-            return new AnnotationTypeStrategy(annotationType, annotation);
-        }
-
-        return new AnnotationInstanceStrategy(Annotations.canonicalizeIfNamed(annotation));
-    }
-
-    /**
-     * Gets the strategy for an annotation type.
-     */
-    static AnnotationStrategy strategyFor(Class<? extends Annotation> annotationType) {
-        annotationType = Annotations.canonicalizeIfNamed(annotationType);
-        if (isAllDefaultMethods(annotationType)) {
-            return strategyFor(generateAnnotation(annotationType));
-        }
-
-        checkNotNull(annotationType, "annotation type");
-        ensureRetainedAtRuntime(annotationType);
-        ensureIsBindingAnnotation(annotationType);
-        return new AnnotationTypeStrategy(annotationType, null);
-
-    }
-
-    private static void ensureRetainedAtRuntime(
-            Class<? extends Annotation> annotationType) {
-        checkArgument(Annotations.isRetainedAtRuntime(annotationType),
-                "%s is not retained at runtime. Please annotate it with @Retention(RUNTIME).",
-                annotationType.getName());
-    }
-
-    private static void ensureIsBindingAnnotation(Class<? extends Annotation> annotationType) {
-        checkArgument(Annotations.isBindingAnnotation(annotationType),
-                "%s is not a binding annotation. Please annotate it with @BindingAnnotation.",
-                annotationType.getName());
-    }
-
-    /**
-     * Computes the hash code for this key.
-     */
+    /** Computes the hash code for this key. */
     private int computeHashCode() {
         return typeLiteral.hashCode() * 31 + annotationStrategy.hashCode();
     }
 
-    /**
-     * @return a {@link Supplier} which memoizes the value for lazy initialization.
-     */
-    private Supplier<String> createToStringSupplier() {
-        // The performance hit on access is acceptable since the intended use is for non-performance-
-        // critical applications.
-        return Suppliers.memoize(new Supplier<String>() {
-            @Override
-            public String get() {
-                return "Key[type=" + typeLiteral + ", annotation=" + annotationStrategy + "]";
-            }
-        });
-    }
-
-    /**
-     * Gets the key type.
-     */
+    /** Gets the key type. */
     public final TypeLiteral<T> getTypeLiteral() {
         return typeLiteral;
     }
 
-    /**
-     * Gets the annotation type.
-     */
+    /** Gets the annotation type. Will be {@code null} if this key lacks an annotation. */
     public final Class<? extends Annotation> getAnnotationType() {
         return annotationStrategy.getAnnotationType();
     }
 
     /**
-     * Gets the annotation.
+     * Gets the annotation instance if available. Will be {@code null} if this key lacks an annotation
+     * <i>or</i> the key was constructed with a {@code Class<Annotation>}.
+     *
+     * <p><b>Warning:</b> this can return null even if this key is annotated. To check whether a
+     * {@code Key} has an annotation use {@link #hasAnnotationType} instead.
      */
+    // TODO(diamondm) consider deprecating this in favor of a method that ISEs if hasAnnotationType()
+    // is true but this would return null.
     public final Annotation getAnnotation() {
         return annotationStrategy.getAnnotation();
     }
@@ -306,9 +161,7 @@ public class Key<T> {
         return typeLiteral.getRawType();
     }
 
-    /**
-     * Gets the key of this key's provider.
-     */
+    /** Gets the key of this key's provider. */
     Key<Provider<T>> providerKey() {
         return ofType(typeLiteral.providerType());
     }
@@ -333,73 +186,136 @@ public class Key<T> {
 
     @Override
     public final String toString() {
-        return toStringSupplier.get();
+        // Note: to not introduce dangerous data races the field should only be read once in this
+        // method.
+        String local = toString;
+        if (local == null) {
+            local = "Key[type=" + typeLiteral + ", annotation=" + annotationStrategy + "]";
+            toString = local;
+        }
+        return local;
     }
 
-    /**
-     * Returns a new key of the specified type with the same annotation as this
-     * key.
-     */
-    public <T> Key<T> ofType(Class<T> type) {
+    /** Gets a key for an injection type and an annotation strategy. */
+    static <T> Key<T> get(Class<T> type, AnnotationStrategy annotationStrategy) {
         return new Key<T>(type, annotationStrategy);
     }
 
+    /** Gets a key for an injection type. */
+    public static <T> Key<T> get(Class<T> type) {
+        return new Key<T>(type, NullAnnotationStrategy.INSTANCE);
+    }
+
+    /** Gets a key for an injection type and an annotation type. */
+    public static <T> Key<T> get(Class<T> type, Class<? extends Annotation> annotationType) {
+        return new Key<T>(type, strategyFor(annotationType));
+    }
+
+    /** Gets a key for an injection type and an annotation. */
+    public static <T> Key<T> get(Class<T> type, Annotation annotation) {
+        return new Key<T>(type, strategyFor(annotation));
+    }
+
+    /** Gets a key for an injection type. */
+    public static Key<?> get(Type type) {
+        return new Key<>(type, NullAnnotationStrategy.INSTANCE);
+    }
+
+    /** Gets a key for an injection type and an annotation type. */
+    public static Key<?> get(Type type, Class<? extends Annotation> annotationType) {
+        return new Key<>(type, strategyFor(annotationType));
+    }
+
+    /** Gets a key for an injection type and an annotation. */
+    public static Key<?> get(Type type, Annotation annotation) {
+        return new Key<>(type, strategyFor(annotation));
+    }
+
+    /** Gets a key for an injection type. */
+    public static <T> Key<T> get(TypeLiteral<T> typeLiteral) {
+        return new Key<T>(typeLiteral, NullAnnotationStrategy.INSTANCE);
+    }
+
+    /** Gets a key for an injection type and an annotation type. */
+    public static <T> Key<T> get(
+            TypeLiteral<T> typeLiteral, Class<? extends Annotation> annotationType) {
+        return new Key<T>(typeLiteral, strategyFor(annotationType));
+    }
+
+    /** Gets a key for an injection type and an annotation. */
+    public static <T> Key<T> get(TypeLiteral<T> typeLiteral, Annotation annotation) {
+        return new Key<T>(typeLiteral, strategyFor(annotation));
+    }
+
     /**
-     * Returns a new key of the specified type with the same annotation as this
-     * key.
+     * Returns a new key of the specified type with the same annotation as this key.
+     *
+     * @since 3.0
+     */
+    public <U> Key<U> ofType(Class<U> type) {
+        return new Key<>(type, annotationStrategy);
+    }
+
+    /**
+     * Returns a new key of the specified type with the same annotation as this key.
+     *
+     * @since 3.0
      */
     public Key<?> ofType(Type type) {
-        return new Key<Object>(type, annotationStrategy);
+        return new Key<>(type, annotationStrategy);
     }
 
     /**
-     * Returns a new key of the specified type with the same annotation as this
-     * key.
+     * Returns a new key of the specified type with the same annotation as this key.
+     *
+     * @since 3.0
      */
-    public <T> Key<T> ofType(TypeLiteral<T> type) {
-        return new Key<T>(type, annotationStrategy);
+    public <U> Key<U> ofType(TypeLiteral<U> type) {
+        return new Key<U>(type, annotationStrategy);
+    }
+
+    /**
+     * Returns a new key of the same type with the specified annotation.
+     *
+     * <p>This is equivalent to {@code Key.get(key.getTypeLiteral(), annotation)} but may be more
+     * convenient to use in certain cases.
+     *
+     * @since 5.0
+     */
+    public Key<T> withAnnotation(Class<? extends Annotation> annotationType) {
+        return new Key<T>(typeLiteral, strategyFor(annotationType));
+    }
+
+    /**
+     * Returns a new key of the same type with the specified annotation.
+     *
+     * <p>This is equivalent to {@code Key.get(key.getTypeLiteral(), annotation)} but may be more
+     * convenient to use in certain cases.
+     *
+     * @since 5.0
+     */
+    public Key<T> withAnnotation(Annotation annotation) {
+        return new Key<T>(typeLiteral, strategyFor(annotation));
     }
 
     /**
      * Returns true if this key has annotation attributes.
+     *
+     * @since 3.0
      */
     public boolean hasAttributes() {
         return annotationStrategy.hasAttributes();
     }
 
     /**
-     * Returns this key without annotation attributes, i.e. with only the
-     * annotation type.
+     * Returns this key without annotation attributes, i.e. with only the annotation type.
+     *
+     * @since 3.0
      */
     public Key<T> withoutAttributes() {
         return new Key<T>(typeLiteral, annotationStrategy.withoutAttributes());
     }
 
-    static enum NullAnnotationStrategy implements AnnotationStrategy {
-        INSTANCE;
-
-        public boolean hasAttributes() {
-            return false;
-        }
-
-        public AnnotationStrategy withoutAttributes() {
-            throw new UnsupportedOperationException("Key already has no attributes.");
-        }
-
-        public Annotation getAnnotation() {
-            return null;
-        }
-
-        public Class<? extends Annotation> getAnnotationType() {
-            return null;
-        }
-
-        @Override
-        public String toString() {
-            return "[none]";
-        }
-    }
-
     interface AnnotationStrategy {
         Annotation getAnnotation();
 
@@ -410,6 +326,76 @@ public class Key<T> {
         AnnotationStrategy withoutAttributes();
     }
 
+    /** Gets the strategy for an annotation. */
+    static AnnotationStrategy strategyFor(Annotation annotation) {
+        checkNotNull(annotation, "annotation");
+        Class<? extends Annotation> annotationType = annotation.annotationType();
+        ensureRetainedAtRuntime(annotationType);
+        ensureIsBindingAnnotation(annotationType);
+
+        if (Annotations.isMarker(annotationType)) {
+            return new AnnotationTypeStrategy(annotationType, annotation);
+        }
+
+        return new AnnotationInstanceStrategy(Annotations.canonicalizeIfNamed(annotation));
+    }
+
+    /** Gets the strategy for an annotation type. */
+    static AnnotationStrategy strategyFor(Class<? extends Annotation> annotationType) {
+        annotationType = Annotations.canonicalizeIfNamed(annotationType);
+        if (isAllDefaultMethods(annotationType)) {
+            return strategyFor(generateAnnotation(annotationType));
+        }
+
+        checkNotNull(annotationType, "annotation type");
+        ensureRetainedAtRuntime(annotationType);
+        ensureIsBindingAnnotation(annotationType);
+        return new AnnotationTypeStrategy(annotationType, null);
+    }
+
+    private static void ensureRetainedAtRuntime(Class<? extends Annotation> annotationType) {
+        checkArgument(
+                Annotations.isRetainedAtRuntime(annotationType),
+                "%s is not retained at runtime. Please annotate it with @Retention(RUNTIME).",
+                annotationType.getName());
+    }
+
+    private static void ensureIsBindingAnnotation(Class<? extends Annotation> annotationType) {
+        checkArgument(
+                Annotations.isBindingAnnotation(annotationType),
+                "%s is not a binding annotation. Please annotate it with @BindingAnnotation.",
+                annotationType.getName());
+    }
+
+    static enum NullAnnotationStrategy implements AnnotationStrategy {
+        INSTANCE;
+
+        @Override
+        public boolean hasAttributes() {
+            return false;
+        }
+
+        @Override
+        public AnnotationStrategy withoutAttributes() {
+            throw new UnsupportedOperationException("Key already has no attributes.");
+        }
+
+        @Override
+        public Annotation getAnnotation() {
+            return null;
+        }
+
+        @Override
+        public Class<? extends Annotation> getAnnotationType() {
+            return null;
+        }
+
+        @Override
+        public String toString() {
+            return "[none]";
+        }
+    }
+
     // this class not test-covered
     static class AnnotationInstanceStrategy implements AnnotationStrategy {
 
@@ -419,18 +405,22 @@ public class Key<T> {
             this.annotation = checkNotNull(annotation, "annotation");
         }
 
+        @Override
         public boolean hasAttributes() {
             return true;
         }
 
+        @Override
         public AnnotationStrategy withoutAttributes() {
             return new AnnotationTypeStrategy(getAnnotationType(), annotation);
         }
 
+        @Override
         public Annotation getAnnotation() {
             return annotation;
         }
 
+        @Override
         public Class<? extends Annotation> getAnnotationType() {
             return annotation.annotationType();
         }
@@ -463,24 +453,27 @@ public class Key<T> {
         // Keep the instance around if we have it so the client can request it.
         final Annotation annotation;
 
-        AnnotationTypeStrategy(Class<? extends Annotation> annotationType,
-                               Annotation annotation) {
+        AnnotationTypeStrategy(Class<? extends Annotation> annotationType, Annotation annotation) {
             this.annotationType = checkNotNull(annotationType, "annotation type");
             this.annotation = annotation;
         }
 
+        @Override
         public boolean hasAttributes() {
             return false;
         }
 
+        @Override
         public AnnotationStrategy withoutAttributes() {
             throw new UnsupportedOperationException("Key already has no attributes.");
         }
 
+        @Override
         public Annotation getAnnotation() {
             return annotation;
         }
 
+        @Override
         public Class<? extends Annotation> getAnnotationType() {
             return annotationType;
         }

src/main/java/com/google/inject/OutOfScopeException.java

@@ -0,0 +1,22 @@
+package com.google.inject;
+
+/**
+ * Thrown from {@link Provider#get} when an attempt is made to access a scoped object while the
+ * scope in question is not currently active.
+ *
+ */
+@SuppressWarnings("serial")
+public final class OutOfScopeException extends RuntimeException {
+
+    public OutOfScopeException(String message) {
+        super(message);
+    }
+
+    public OutOfScopeException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public OutOfScopeException(Throwable cause) {
+        super(cause);
+    }
+}

src/main/java/com/google/inject/PrivateBinder.java

@@ -31,5 +31,5 @@ public interface PrivateBinder extends Binder {
 
     PrivateBinder withSource(Object source);
 
-    PrivateBinder skipSources(Class... classesToSkip);
+    PrivateBinder skipSources(Class<?>... classesToSkip);
 }

src/main/java/com/google/inject/ProvidedBy.java

@@ -2,6 +2,7 @@ package com.google.inject;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.Target;
+import javax.inject.Provider;
 
 import static java.lang.annotation.ElementType.TYPE;
 import static java.lang.annotation.RetentionPolicy.RUNTIME;

src/main/java/com/google/inject/Provider.java

@@ -32,5 +32,6 @@ public interface Provider<T> extends javax.inject.Provider<T> {
      * @throws ProvisionException  if an instance cannot be provided. Such exceptions include messages
      *                             and throwables to describe why provision failed.
      */
+    @Override
     T get();
 }

src/main/java/com/google/inject/ProvisionException.java

@@ -1,7 +1,7 @@
 package com.google.inject;
 
 import com.google.common.collect.ImmutableSet;
-import com.google.inject.internal.Errors;
+import com.google.inject.internal.Messages;
 import com.google.inject.spi.Message;
 
 import java.util.Collection;
@@ -23,7 +23,7 @@ public final class ProvisionException extends RuntimeException {
     public ProvisionException(Iterable<Message> messages) {
         this.messages = ImmutableSet.copyOf(messages);
         checkArgument(!this.messages.isEmpty());
-        initCause(Errors.getOnlyCause(this.messages));
+        initCause(Messages.getOnlyCause(this.messages));
     }
 
     public ProvisionException(String message, Throwable cause) {
@@ -44,6 +44,6 @@ public final class ProvisionException extends RuntimeException {
 
     @Override
     public String getMessage() {
-        return Errors.format("Unable to provision, see the following errors", messages);
+        return Messages.formatMessages("Unable to provision, see the following errors", messages);
     }
 }

src/main/java/com/google/inject/RestrictedBindingSource.java

@@ -0,0 +1,120 @@
+package com.google.inject;
+
+import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
+import static java.lang.annotation.ElementType.TYPE;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+import java.lang.annotation.Annotation;
+import java.lang.annotation.Documented;
+import java.lang.annotation.Inherited;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+/**
+ * Annotation restricting the binding of the target type to permitted sources.
+ *
+ * <p>Bindings restricted by this annotation may only be created by sources annotated with a permit
+ * from {@link #permits} -- otherwise, an error message including the {@link #explanation} is
+ * issued.
+ *
+ * <p>There are two kinds of binding source:
+ *
+ * <ol>
+ *   <li>Module: a module is the source of a binding if it creates it (either directly, or
+ *       indirectly by installing another module). For example: if module A creates restricted
+ *       binding X, and module C installs module B that installs A; then all 3 modules C,B,A are
+ *       sources of X, and it's enough for any one of them to be annotated with a permit from X's
+ *       restriction.
+ *   <li>Method Scanner ({@code ModuleAnnotatedMethodScanner}): If a binding was created by a
+ *       scanner, then that scanner is also a source of the binding (in addition to the module
+ *       sources) and a permit may be given to the scanner by annotating its class.
+ * </ol>
+ *
+ * <p>Bindings with qualifier annotations are restricted solely by the annotation on their qualifier
+ * (restrictions on the type are ignored for qualified bindings). Unqualified bindings are
+ * restricted by the annotation on their type.
+ *
+ * <p>This allows libraries to prevent their clients from binding their keys, similar to how
+ * declaring a class final prevents subtyping. For example, a library may want to prevent users from
+ * creating mock bindings for tests, using the {@link #explanation} - included in the error message
+ * - to point them to a supported testing module.
+ *
+ * <p>Example usage:
+ *
+ * <pre>{@code
+ * @RestrictedBindingSource.Permit
+ * @Retention(RetentionPolicy.RUNTIME)
+ * @interface NetworkPermit {}
+ *
+ * @RestrictedBindingSource(
+ *   explanation = "Only NetworkModule can create network bindings.",
+ *   permits = {NetworkPermit.class})
+ * @Qualifier
+ * @Retention(RetentionPolicy.RUNTIME)
+ * public @interface GatewayIpAdress {}
+ *
+ * @NetworkPermit
+ * public final class NetworkModule extends AbstractModule {
+ *   @Provides
+ *   @GatewayIpAdress // Allowed because the module is annotated with @NetworkPermit.
+ *   int provideGatewayIp() { ... }
+ * }
+ * }</pre>
+ *
+ * @author vzm@google.com (Vladimir Makaric)
+ * @since 5.0
+ */
+@Inherited
+@Retention(RUNTIME)
+@Target(TYPE)
+public @interface RestrictedBindingSource {
+  /**
+   * Explanation of why binding this target type is restricted.
+   *
+   * <p>Will appear as the error message if the target type is bound by non-allowed modules.
+   */
+  String explanation();
+
+  /**
+   * Meta-annotation indicating that the target annotation is a permit for binding restricted
+   * bindings. Annotating a binding source (defined in top-level javadoc) with a permit gives it
+   * permission to bind the restricted bindings guarded by the permit (see {@link #permits}).
+   *
+   * @since 5.0
+   */
+  @Documented
+  @Retention(RUNTIME)
+  @Target(ANNOTATION_TYPE)
+  public @interface Permit {}
+
+  /**
+   * List of {@code Permit} annotations (must be non-empty), one of which has has to be present on a
+   * restricted binding's source (defined in top-level javadoc).
+   */
+  Class<? extends Annotation>[] permits();
+
+  /**
+   * Exempt modules whose fully qualified class names match this regex.
+   *
+   * <p>If any module on the binding's module stack matches this regex, the binding is allowed (no
+   * permit necessary). No module is exempt by default (empty string).
+   *
+   * <p>Inteded to be used when retrofitting a binding with this restriction. When restricting an
+   * existing binding, it's often practical to first restrict with exemptions for existing
+   * violations (to prevent new violations), before updating the code in violation to use the
+   * permitted module(s).
+   */
+  String exemptModules() default "";
+
+  /**
+   * Level of restriction. Determines how violations are handled.
+   *
+   * @since 5.0
+   */
+  public static enum RestrictionLevel {
+    WARNING,
+    ERROR;
+  }
+
+  RestrictionLevel restrictionLevel() default RestrictionLevel.ERROR;
+}

src/main/java/com/google/inject/Scopes.java

@@ -28,6 +28,7 @@ public class Scopes {
      * this to "no scope" in your binding.
      */
     public static final Scope NO_SCOPE = new Scope() {
+        @Override
         public <T> Provider<T> scope(Key<T> key, Provider<T> unscoped) {
             return unscoped;
         }
@@ -37,21 +38,26 @@ public class Scopes {
             return "Scopes.NO_SCOPE";
         }
     };
+
     private static final BindingScopingVisitor<Boolean> IS_SINGLETON_VISITOR
-            = new BindingScopingVisitor<Boolean>() {
+            = new BindingScopingVisitor<>() {
+        @Override
         public Boolean visitNoScoping() {
             return false;
         }
 
+        @Override
         public Boolean visitScopeAnnotation(Class<? extends Annotation> scopeAnnotation) {
             return scopeAnnotation == Singleton.class
                     || scopeAnnotation == javax.inject.Singleton.class;
         }
 
+        @Override
         public Boolean visitScope(Scope scope) {
             return scope == Scopes.SINGLETON;
         }
 
+        @Override
         public Boolean visitEagerSingleton() {
             return true;
         }
@@ -107,18 +113,22 @@ public class Scopes {
                                    final Class<? extends Annotation> scopeAnnotation) {
         do {
             boolean matches = binding.acceptScopingVisitor(new BindingScopingVisitor<Boolean>() {
+                @Override
                 public Boolean visitNoScoping() {
                     return false;
                 }
 
+                @Override
                 public Boolean visitScopeAnnotation(Class<? extends Annotation> visitedAnnotation) {
                     return visitedAnnotation == scopeAnnotation;
                 }
 
+                @Override
                 public Boolean visitScope(Scope visitedScope) {
                     return visitedScope == scope;
                 }
 
+                @Override
                 public Boolean visitEagerSingleton() {
                     return false;
                 }

src/main/java/com/google/inject/TypeLiteral.java

@@ -170,7 +170,7 @@ public class TypeLiteral<T> {
         // this implementation is made a little more complicated in an attempt to avoid object-creation
         while (true) {
             if (toResolve instanceof TypeVariable) {
-                TypeVariable original = (TypeVariable) toResolve;
+                TypeVariable<?> original = (TypeVariable) toResolve;
                 toResolve = MoreTypes.resolveTypeVariable(type, rawType, original);
                 if (toResolve == original) {
                     return toResolve;

src/main/java/com/google/inject/assistedinject/FactoryModuleBuilder.java

@@ -5,14 +5,15 @@ import com.google.inject.Key;
 import com.google.inject.Module;
 import com.google.inject.Provider;
 import com.google.inject.TypeLiteral;
-
 import java.lang.annotation.Annotation;
+import java.lang.invoke.MethodHandles;
 
 /**
  * Provides a factory that combines the caller's arguments with injector-supplied values to
  * construct objects.
  *
  * <h3>Defining a factory</h3>
+ *
  * Create an interface whose methods return the constructed type, or any of its supertypes. The
  * method's parameters are the arguments required to build the constructed type.
  *
@@ -24,6 +25,7 @@ import java.lang.annotation.Annotation;
  * or <i>newPayment</i>.
  *
  * <h3>Creating a type that accepts factory parameters</h3>
+ *
  * {@code constructedType} is a concrete class with an {@literal @}{@link com.google.inject.Inject
  * Inject}-annotated constructor. In addition to injector-supplied parameters, the constructor
  * should have parameters that match each of the factory method's parameters. Each factory-supplied
@@ -42,10 +44,10 @@ import java.lang.annotation.Annotation;
  * }</pre>
  *
  * <h3>Multiple factory methods for the same type</h3>
+ *
  * If the factory contains many methods that return the same type, you can create multiple
- * constructors in your concrete class, each constructor marked with with
- * {@literal @}{@link AssistedInject}, in order to match the different parameters types of the
- * factory methods.
+ * constructors in your concrete class, each constructor marked with with {@literal @}{@link
+ * AssistedInject}, in order to match the different parameters types of the factory methods.
  *
  * <pre>public interface PaymentFactory {
  *    Payment create(Date startDate, Money amount);
@@ -72,8 +74,8 @@ import java.lang.annotation.Annotation;
  * }</pre>
  *
  * <h3>Configuring simple factories</h3>
- * In your {@link Module module}, install a {@code FactoryModuleBuilder} that creates the
- * factory:
+ *
+ * In your {@link Module module}, install a {@code FactoryModuleBuilder} that creates the factory:
  *
  * <pre>install(new FactoryModuleBuilder()
  *     .implement(Payment.class, RealPayment.class)
@@ -83,8 +85,9 @@ import java.lang.annotation.Annotation;
  * factory cannot be used until the injector has been initialized.
  *
  * <h3>Configuring complex factories</h3>
- * Factories can create an arbitrary number of objects, one per each method.  Each factory
- * method can be configured using <code>.implement</code>.
+ *
+ * Factories can create an arbitrary number of objects, one per each method. Each factory method can
+ * be configured using <code>.implement</code>.
  *
  * <pre>public interface OrderFactory {
  *    Payment create(Date startDate, Money amount);
@@ -100,11 +103,13 @@ import java.lang.annotation.Annotation;
  *     // will be 'Shipment' itself, which is legal if it's not an interface.
  *     .implement(Receipt.class, RealReceipt.class)
  *     .build(OrderFactory.class));</pre>
+ *
  * </pre>
  *
  * <h3>Using the factory</h3>
- * Inject your factory into your application classes. When you use the factory, your arguments
- * will be combined with values from the injector to construct an instance.
+ *
+ * Inject your factory into your application classes. When you use the factory, your arguments will
+ * be combined with values from the injector to construct an instance.
  *
  * <pre>public class PaymentAction {
  *   {@literal @}Inject private PaymentFactory paymentFactory;
@@ -116,9 +121,10 @@ import java.lang.annotation.Annotation;
  * }</pre>
  *
  * <h3>Making parameter types distinct</h3>
- * The types of the factory method's parameters must be distinct. To use multiple parameters of
- * the same type, use a named {@literal @}{@link Assisted} annotation to disambiguate the
- * parameters. The names must be applied to the factory method's parameters:
+ *
+ * The types of the factory method's parameters must be distinct. To use multiple parameters of the
+ * same type, use a named {@literal @}{@link Assisted} annotation to disambiguate the parameters.
+ * The names must be applied to the factory method's parameters:
  *
  * <pre>public interface PaymentFactory {
  *   Payment create(
@@ -142,15 +148,17 @@ import java.lang.annotation.Annotation;
  * }</pre>
  *
  * <h3>Values are created by Guice</h3>
+ *
  * Returned factories use child injectors to create values. The values are eligible for method
  * interception. In addition, {@literal @}{@literal Inject} members will be injected before they are
  * returned.
  *
  * <h3>More configuration options</h3>
+ *
  * In addition to simply specifying an implementation class for any returned type, factories' return
  * values can be automatic or can be configured to use annotations:
- * <p/>
- * If you just want to return the types specified in the factory, do not configure any
+ *
+ * <p>If you just want to return the types specified in the factory, do not configure any
  * implementations:
  *
  * <pre>public interface FruitFactory {
@@ -162,8 +170,8 @@ import java.lang.annotation.Annotation;
  * }</pre>
  *
  * Note that any type returned by the factory in this manner needs to be an implementation class.
- * <p/>
- * To return two different implementations for the same interface from your factory, use binding
+ *
+ * <p>To return two different implementations for the same interface from your factory, use binding
  * annotations on your return types:
  *
  * <pre>interface CarFactory {
@@ -179,142 +187,138 @@ import java.lang.annotation.Annotation;
  * }</pre>
  *
  * <h3>Implementation limitations</h3>
- * As a limitation of the implementation, it is prohibited to declare a factory method that
- * accepts a {@code Provider} as one of its arguments.
+ *
+ * As a limitation of the implementation, it is prohibited to declare a factory method that accepts
+ * a {@code Provider} as one of its arguments.
+ *
+ * @since 3.0
+ * @author schmitt@google.com (Peter Schmitt)
  */
 public final class FactoryModuleBuilder {
 
     private final BindingCollector bindings = new BindingCollector();
+    private MethodHandles.Lookup lookups;
 
-    /**
-     * See the factory configuration examples at {@link FactoryModuleBuilder}.
-     */
+    /** See the factory configuration examples at {@link FactoryModuleBuilder}. */
     public <T> FactoryModuleBuilder implement(Class<T> source, Class<? extends T> target) {
         return implement(source, TypeLiteral.get(target));
     }
 
-    /**
-     * See the factory configuration examples at {@link FactoryModuleBuilder}.
-     */
+    /** See the factory configuration examples at {@link FactoryModuleBuilder}. */
     public <T> FactoryModuleBuilder implement(Class<T> source, TypeLiteral<? extends T> target) {
         return implement(TypeLiteral.get(source), target);
     }
 
-    /**
-     * See the factory configuration examples at {@link FactoryModuleBuilder}.
-     */
+    /** See the factory configuration examples at {@link FactoryModuleBuilder}. */
     public <T> FactoryModuleBuilder implement(TypeLiteral<T> source, Class<? extends T> target) {
         return implement(source, TypeLiteral.get(target));
     }
 
-    /**
-     * See the factory configuration examples at {@link FactoryModuleBuilder}.
-     */
-    public <T> FactoryModuleBuilder implement(TypeLiteral<T> source,
-                                              TypeLiteral<? extends T> target) {
+    /** See the factory configuration examples at {@link FactoryModuleBuilder}. */
+    public <T> FactoryModuleBuilder implement(
+            TypeLiteral<T> source, TypeLiteral<? extends T> target) {
         return implement(Key.get(source), target);
     }
 
-    /**
-     * See the factory configuration examples at {@link FactoryModuleBuilder}.
-     */
-    public <T> FactoryModuleBuilder implement(Class<T> source, Annotation annotation,
-                                              Class<? extends T> target) {
+    /** See the factory configuration examples at {@link FactoryModuleBuilder}. */
+    public <T> FactoryModuleBuilder implement(
+            Class<T> source, Annotation annotation, Class<? extends T> target) {
         return implement(source, annotation, TypeLiteral.get(target));
     }
 
-    /**
-     * See the factory configuration examples at {@link FactoryModuleBuilder}.
-     */
-    public <T> FactoryModuleBuilder implement(Class<T> source, Annotation annotation,
-                                              TypeLiteral<? extends T> target) {
+    /** See the factory configuration examples at {@link FactoryModuleBuilder}. */
+    public <T> FactoryModuleBuilder implement(
+            Class<T> source, Annotation annotation, TypeLiteral<? extends T> target) {
         return implement(TypeLiteral.get(source), annotation, target);
     }
 
-    /**
-     * See the factory configuration examples at {@link FactoryModuleBuilder}.
-     */
-    public <T> FactoryModuleBuilder implement(TypeLiteral<T> source, Annotation annotation,
-                                              Class<? extends T> target) {
+    /** See the factory configuration examples at {@link FactoryModuleBuilder}. */
+    public <T> FactoryModuleBuilder implement(
+            TypeLiteral<T> source, Annotation annotation, Class<? extends T> target) {
         return implement(source, annotation, TypeLiteral.get(target));
     }
 
-    /**
-     * See the factory configuration examples at {@link FactoryModuleBuilder}.
-     */
-    public <T> FactoryModuleBuilder implement(TypeLiteral<T> source, Annotation annotation,
-                                              TypeLiteral<? extends T> target) {
+    /** See the factory configuration examples at {@link FactoryModuleBuilder}. */
+    public <T> FactoryModuleBuilder implement(
+            TypeLiteral<T> source, Annotation annotation, TypeLiteral<? extends T> target) {
         return implement(Key.get(source, annotation), target);
     }
 
-    /**
-     * See the factory configuration examples at {@link FactoryModuleBuilder}.
-     */
-    public <T> FactoryModuleBuilder implement(Class<T> source,
-                                              Class<? extends Annotation> annotationType, Class<? extends T> target) {
+    /** See the factory configuration examples at {@link FactoryModuleBuilder}. */
+    public <T> FactoryModuleBuilder implement(
+            Class<T> source, Class<? extends Annotation> annotationType, Class<? extends T> target) {
         return implement(source, annotationType, TypeLiteral.get(target));
     }
 
-    /**
-     * See the factory configuration examples at {@link FactoryModuleBuilder}.
-     */
-    public <T> FactoryModuleBuilder implement(Class<T> source,
-                                              Class<? extends Annotation> annotationType, TypeLiteral<? extends T> target) {
+    /** See the factory configuration examples at {@link FactoryModuleBuilder}. */
+    public <T> FactoryModuleBuilder implement(
+            Class<T> source,
+            Class<? extends Annotation> annotationType,
+            TypeLiteral<? extends T> target) {
         return implement(TypeLiteral.get(source), annotationType, target);
     }
 
-    /**
-     * See the factory configuration examples at {@link FactoryModuleBuilder}.
-     */
-    public <T> FactoryModuleBuilder implement(TypeLiteral<T> source,
-                                              Class<? extends Annotation> annotationType, Class<? extends T> target) {
+    /** See the factory configuration examples at {@link FactoryModuleBuilder}. */
+    public <T> FactoryModuleBuilder implement(
+            TypeLiteral<T> source,
+            Class<? extends Annotation> annotationType,
+            Class<? extends T> target) {
         return implement(source, annotationType, TypeLiteral.get(target));
     }
 
-    /**
-     * See the factory configuration examples at {@link FactoryModuleBuilder}.
-     */
-    public <T> FactoryModuleBuilder implement(TypeLiteral<T> source,
-                                              Class<? extends Annotation> annotationType, TypeLiteral<? extends T> target) {
+    /** See the factory configuration examples at {@link FactoryModuleBuilder}. */
+    public <T> FactoryModuleBuilder implement(
+            TypeLiteral<T> source,
+            Class<? extends Annotation> annotationType,
+            TypeLiteral<? extends T> target) {
         return implement(Key.get(source, annotationType), target);
     }
 
-    /**
-     * See the factory configuration examples at {@link FactoryModuleBuilder}.
-     */
+    /** See the factory configuration examples at {@link FactoryModuleBuilder}. */
     public <T> FactoryModuleBuilder implement(Key<T> source, Class<? extends T> target) {
         return implement(source, TypeLiteral.get(target));
     }
 
-    /**
-     * See the factory configuration examples at {@link FactoryModuleBuilder}.
-     */
+    /** See the factory configuration examples at {@link FactoryModuleBuilder}. */
     public <T> FactoryModuleBuilder implement(Key<T> source, TypeLiteral<? extends T> target) {
         bindings.addBinding(source, target);
         return this;
     }
 
     /**
-     * See the factory configuration examples at {@link FactoryModuleBuilder}.
+     * Typically called via {@code withLookups(MethodHandles.lookup())}. Sets the MethodHandles.Lookup
+     * that the factory implementation will use to call default methods on the factory interface.
+     * While this is not always required, it is always OK to set it. It is required if the factory
+     * passed to {@link #build} is non-public and javac generated default methods while compiling it
+     * (which javac can sometimes do if the factory uses generic types).
+     *
+     * <p>Guice will try to work properly even if this method is not called (or called with a lookups
+     * that doesn't have access to the factory), but doing so requires reflection into the JDK, which
+     * may break at any time (and trigger unsafe access warnings).
+     *
+     * @since 5.0
      */
+    public <T> FactoryModuleBuilder withLookups(MethodHandles.Lookup lookups) {
+        this.lookups = lookups;
+        return this;
+    }
+
+    /** See the factory configuration examples at {@link FactoryModuleBuilder}. */
     public <F> Module build(Class<F> factoryInterface) {
         return build(TypeLiteral.get(factoryInterface));
     }
 
-    /**
-     * See the factory configuration examples at {@link FactoryModuleBuilder}.
-     */
+    /** See the factory configuration examples at {@link FactoryModuleBuilder}. */
     public <F> Module build(TypeLiteral<F> factoryInterface) {
         return build(Key.get(factoryInterface));
     }
 
-
     public <F> Module build(final Key<F> factoryInterface) {
         return new AbstractModule() {
             @Override
             protected void configure() {
-                Provider<F> provider = new FactoryProvider2<F>(factoryInterface, bindings);
-                bind(factoryInterface).toProvider(provider);
+                Provider<F> provider = new FactoryProvider2<>(factoryInterface, bindings, lookups);
+                binder().skipSources(this.getClass()).bind(factoryInterface).toProvider(provider);
             }
         };
     }

src/main/java/com/google/inject/assistedinject/FactoryProvider.java

@@ -1,5 +1,7 @@
 package com.google.inject.assistedinject;
 
+import static com.google.inject.internal.Annotations.getKey;
+
 import com.google.common.base.Objects;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
@@ -16,7 +18,6 @@ import com.google.inject.internal.ErrorsException;
 import com.google.inject.spi.Dependency;
 import com.google.inject.spi.HasDependencies;
 import com.google.inject.spi.Message;
-
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationHandler;
@@ -27,8 +28,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
-import static com.google.inject.internal.Annotations.getKey;
-
 /**
  * <strong>Obsolete.</strong> Prefer {@link FactoryModuleBuilder} for its more concise API and
  * additional capability.
@@ -37,20 +36,25 @@ import static com.google.inject.internal.Annotations.getKey;
  * construct objects.
  *
  * <h3>Defining a factory</h3>
+ *
  * Create an interface whose methods return the constructed type, or any of its supertypes. The
  * method's parameters are the arguments required to build the constructed type.
+ *
  * <pre>public interface PaymentFactory {
  *   Payment create(Date startDate, Money amount);
  * }</pre>
+ *
  * You can name your factory methods whatever you like, such as <i>create</i>, <i>createPayment</i>
  * or <i>newPayment</i>.
  *
  * <h3>Creating a type that accepts factory parameters</h3>
+ *
  * {@code constructedType} is a concrete class with an {@literal @}{@link Inject}-annotated
- * constructor. In addition to injector-supplied parameters, the constructor should have
- * parameters that match each of the factory method's parameters. Each factory-supplied parameter
- * requires an {@literal @}{@link Assisted} annotation. This serves to document that the parameter
- * is not bound by your application's modules.
+ * constructor. In addition to injector-supplied parameters, the constructor should have parameters
+ * that match each of the factory method's parameters. Each factory-supplied parameter requires an
+ * {@literal @}{@link Assisted} annotation. This serves to document that the parameter is not bound
+ * by your application's modules.
+ *
  * <pre>public class RealPayment implements Payment {
  *   {@literal @}Inject
  *   public RealPayment(
@@ -61,19 +65,25 @@ import static com.google.inject.internal.Annotations.getKey;
  *     ...
  *   }
  * }</pre>
+ *
  * Any parameter that permits a null value should also be annotated {@code @Nullable}.
  *
  * <h3>Configuring factories</h3>
+ *
  * In your {@link com.google.inject.Module module}, bind the factory interface to the returned
  * factory:
+ *
  * <pre>bind(PaymentFactory.class).toProvider(
  *     FactoryProvider.newFactory(PaymentFactory.class, RealPayment.class));</pre>
+ *
  * As a side-effect of this binding, Guice will inject the factory to initialize it for use. The
  * factory cannot be used until the injector has been initialized.
  *
  * <h3>Using the factory</h3>
- * Inject your factory into your application classes. When you use the factory, your arguments
- * will be combined with values from the injector to construct an instance.
+ *
+ * Inject your factory into your application classes. When you use the factory, your arguments will
+ * be combined with values from the injector to construct an instance.
+ *
  * <pre>public class PaymentAction {
  *   {@literal @}Inject private PaymentFactory paymentFactory;
  *
@@ -84,9 +94,10 @@ import static com.google.inject.internal.Annotations.getKey;
  * }</pre>
  *
  * <h3>Making parameter types distinct</h3>
- * The types of the factory method's parameters must be distinct. To use multiple parameters of
- * the same type, use a named {@literal @}{@link Assisted} annotation to disambiguate the
- * parameters. The names must be applied to the factory method's parameters:
+ *
+ * The types of the factory method's parameters must be distinct. To use multiple parameters of the
+ * same type, use a named {@literal @}{@link Assisted} annotation to disambiguate the parameters.
+ * The names must be applied to the factory method's parameters:
  *
  * <pre>public interface PaymentFactory {
  *   Payment create(
@@ -94,7 +105,9 @@ import static com.google.inject.internal.Annotations.getKey;
  *       <strong>{@literal @}Assisted("dueDate")</strong> Date dueDate,
  *       Money amount);
  * } </pre>
+ *
  * ...and to the concrete type's constructor parameters:
+ *
  * <pre>public class RealPayment implements Payment {
  *   {@literal @}Inject
  *   public RealPayment(
@@ -108,23 +121,27 @@ import static com.google.inject.internal.Annotations.getKey;
  * }</pre>
  *
  * <h3>Values are created by Guice</h3>
+ *
  * Returned factories use child injectors to create values. The values are eligible for method
  * interception. In addition, {@literal @}{@literal Inject} members will be injected before they are
  * returned.
  *
  * <h3>Backwards compatibility using {@literal @}AssistedInject</h3>
+ *
  * Instead of the {@literal @}Inject annotation, you may annotate the constructed classes with
  * {@literal @}{@link AssistedInject}. This triggers a limited backwards-compatability mode.
  *
  * <p>Instead of matching factory method arguments to constructor parameters using their names, the
- * <strong>parameters are matched by their order</strong>. The first factory method argument is
- * used for the first {@literal @}Assisted constructor parameter, etc.. Annotation names have no
- * effect.
+ * <strong>parameters are matched by their order</strong>. The first factory method argument is used
+ * for the first {@literal @}Assisted constructor parameter, etc.. Annotation names have no effect.
  *
  * <p>Returned values are <strong>not created by Guice</strong>. These types are not eligible for
  * method interception. They do receive post-construction member injection.
  *
  * @param <F> The factory interface
+ * @author jmourits@google.com (Jerome Mourits)
+ * @author jessewilson@google.com (Jesse Wilson)
+ * @author dtm@google.com (Daniel Martin)
  * @deprecated use {@link FactoryModuleBuilder} instead.
  */
 @Deprecated
@@ -135,19 +152,11 @@ public class FactoryProvider<F> implements Provider<F>, HasDependencies {
      * to factory methods. The new child injector implementation lives in FactoryProvider2.
      */
 
+    private Injector injector;
+
     private final TypeLiteral<F> factoryType;
     private final TypeLiteral<?> implementationType;
     private final Map<Method, AssistedConstructor<?>> factoryMethodToConstructor;
-    private Injector injector;
-
-    private FactoryProvider(TypeLiteral<F> factoryType,
-                            TypeLiteral<?> implementationType,
-                            Map<Method, AssistedConstructor<?>> factoryMethodToConstructor) {
-        this.factoryType = factoryType;
-        this.implementationType = implementationType;
-        this.factoryMethodToConstructor = factoryMethodToConstructor;
-        checkDeclaredExceptionsMatch();
-    }
 
     public static <F> Provider<F> newFactory(Class<F> factoryType, Class<?> implementationType) {
         return newFactory(TypeLiteral.get(factoryType), TypeLiteral.get(implementationType));
@@ -155,8 +164,8 @@ public class FactoryProvider<F> implements Provider<F>, HasDependencies {
 
     public static <F> Provider<F> newFactory(
             TypeLiteral<F> factoryType, TypeLiteral<?> implementationType) {
-        Map<Method, AssistedConstructor<?>> factoryMethodToConstructor
-                = createMethodMapping(factoryType, implementationType);
+        Map<Method, AssistedConstructor<?>> factoryMethodToConstructor =
+                createMethodMapping(factoryType, implementationType);
 
         if (!factoryMethodToConstructor.isEmpty()) {
             return new FactoryProvider<F>(factoryType, implementationType, factoryMethodToConstructor);
@@ -170,8 +179,8 @@ public class FactoryProvider<F> implements Provider<F>, HasDependencies {
 
             try {
                 for (Method method : factoryType.getRawType().getMethods()) {
-                    Key<?> returnType = getKey(factoryType.getReturnType(method), method,
-                            method.getAnnotations(), errors);
+                    Key<?> returnType =
+                            getKey(factoryType.getReturnType(method), method, method.getAnnotations(), errors);
                     if (!implementationKey.equals(returnType)) {
                         collector.addBinding(returnType, implementationType);
                     }
@@ -180,83 +189,18 @@ public class FactoryProvider<F> implements Provider<F>, HasDependencies {
                 throw new ConfigurationException(e.getErrors().getMessages());
             }
 
-            return new FactoryProvider2<F>(Key.get(factoryType), collector);
+            return new FactoryProvider2<F>(Key.get(factoryType), collector, /* userLookups= */ null);
         }
     }
 
-    private static Map<Method, AssistedConstructor<?>> createMethodMapping(
-            TypeLiteral<?> factoryType, TypeLiteral<?> implementationType) {
-        List<AssistedConstructor<?>> constructors = Lists.newArrayList();
-
-        for (Constructor<?> constructor : implementationType.getRawType().getDeclaredConstructors()) {
-            if (constructor.isAnnotationPresent(AssistedInject.class)) {
-                AssistedConstructor<?> assistedConstructor = AssistedConstructor.create(
-                        constructor, implementationType.getParameterTypes(constructor));
-                constructors.add(assistedConstructor);
-            }
-        }
-
-        if (constructors.isEmpty()) {
-            return ImmutableMap.of();
-        }
-
-        Method[] factoryMethods = factoryType.getRawType().getMethods();
-
-        if (constructors.size() != factoryMethods.length) {
-            throw newConfigurationException("Constructor mismatch: %s has %s @AssistedInject "
-                            + "constructors, factory %s has %s creation methods", implementationType,
-                    constructors.size(), factoryType, factoryMethods.length);
-        }
-
-        Map<ParameterListKey, AssistedConstructor<?>> paramsToConstructor = Maps.newHashMap();
-
-        for (AssistedConstructor<?> c : constructors) {
-            if (paramsToConstructor.containsKey(c.getAssistedParameters())) {
-                throw new RuntimeException("Duplicate constructor, " + c);
-            }
-            paramsToConstructor.put(c.getAssistedParameters(), c);
-        }
-
-        Map<Method, AssistedConstructor<?>> result = Maps.newHashMap();
-        for (Method method : factoryMethods) {
-            if (!method.getReturnType().isAssignableFrom(implementationType.getRawType())) {
-                throw newConfigurationException("Return type of method %s is not assignable from %s",
-                        method, implementationType);
-            }
-
-            List<Type> parameterTypes = Lists.newArrayList();
-            for (TypeLiteral<?> parameterType : factoryType.getParameterTypes(method)) {
-                parameterTypes.add(parameterType.getType());
-            }
-            ParameterListKey methodParams = new ParameterListKey(parameterTypes);
-
-            if (!paramsToConstructor.containsKey(methodParams)) {
-                throw newConfigurationException("%s has no @AssistInject constructor that takes the "
-                                + "@Assisted parameters %s in that order. @AssistInject constructors are %s",
-                        implementationType, methodParams, paramsToConstructor.values());
-            }
-
-            method.getParameterAnnotations();
-            for (Annotation[] parameterAnnotations : method.getParameterAnnotations()) {
-                for (Annotation parameterAnnotation : parameterAnnotations) {
-                    if (parameterAnnotation.annotationType() == Assisted.class) {
-                        throw newConfigurationException("Factory method %s has an @Assisted parameter, which "
-                                        + "is incompatible with the deprecated @AssistedInject annotation. Please replace "
-                                        + "@AssistedInject with @Inject on the %s constructor.",
-                                method, implementationType);
-                    }
-                }
-            }
-
-            AssistedConstructor<?> matchingConstructor = paramsToConstructor.remove(methodParams);
-
-            result.put(method, matchingConstructor);
-        }
-        return result;
-    }
-
-    private static ConfigurationException newConfigurationException(String format, Object... args) {
-        return new ConfigurationException(ImmutableSet.of(new Message(Errors.format(format, args))));
+    private FactoryProvider(
+            TypeLiteral<F> factoryType,
+            TypeLiteral<?> implementationType,
+            Map<Method, AssistedConstructor<?>> factoryMethodToConstructor) {
+        this.factoryType = factoryType;
+        this.implementationType = implementationType;
+        this.factoryMethodToConstructor = factoryMethodToConstructor;
+        checkDeclaredExceptionsMatch();
     }
 
     @Inject
@@ -268,8 +212,10 @@ public class FactoryProvider<F> implements Provider<F>, HasDependencies {
                     // this is lame - we're not using the proper mechanism to add an
                     // error to the injector. Throughout this class we throw exceptions
                     // to add errors, which isn't really the best way in Guice
-                    throw newConfigurationException("Parameter of type '%s' is not injectable or annotated "
-                            + "with @Assisted for Constructor '%s'", p, c);
+                    throw newConfigurationException(
+                            "Parameter of type '%s' is not injectable or annotated "
+                                    + "with @Assisted for Constructor '%s'",
+                            p, c);
                 }
             }
         }
@@ -280,8 +226,10 @@ public class FactoryProvider<F> implements Provider<F>, HasDependencies {
             for (Class<?> constructorException : entry.getValue().getDeclaredExceptions()) {
                 if (!isConstructorExceptionCompatibleWithFactoryExeception(
                         constructorException, entry.getKey().getExceptionTypes())) {
-                    throw newConfigurationException("Constructor %s declares an exception, but no compatible "
-                            + "exception is thrown by the factory method %s", entry.getValue(), entry.getKey());
+                    throw newConfigurationException(
+                            "Constructor %s declares an exception, but no compatible "
+                                    + "exception is thrown by the factory method %s",
+                            entry.getValue(), entry.getKey());
                 }
             }
         }
@@ -301,6 +249,82 @@ public class FactoryProvider<F> implements Provider<F>, HasDependencies {
         return parameter.isBound(injector);
     }
 
+    private static Map<Method, AssistedConstructor<?>> createMethodMapping(
+            TypeLiteral<?> factoryType, TypeLiteral<?> implementationType) {
+        List<AssistedConstructor<?>> constructors = Lists.newArrayList();
+
+        for (Constructor<?> constructor : implementationType.getRawType().getDeclaredConstructors()) {
+            if (constructor.isAnnotationPresent(AssistedInject.class)) {
+                AssistedConstructor<?> assistedConstructor =
+                        AssistedConstructor.create(
+                                constructor, implementationType.getParameterTypes(constructor));
+                constructors.add(assistedConstructor);
+            }
+        }
+
+        if (constructors.isEmpty()) {
+            return ImmutableMap.of();
+        }
+
+        Method[] factoryMethods = factoryType.getRawType().getMethods();
+
+        if (constructors.size() != factoryMethods.length) {
+            throw newConfigurationException(
+                    "Constructor mismatch: %s has %s @AssistedInject "
+                            + "constructors, factory %s has %s creation methods",
+                    implementationType, constructors.size(), factoryType, factoryMethods.length);
+        }
+
+        Map<ParameterListKey, AssistedConstructor<?>> paramsToConstructor = Maps.newHashMap();
+
+        for (AssistedConstructor<?> c : constructors) {
+            if (paramsToConstructor.containsKey(c.getAssistedParameters())) {
+                throw new RuntimeException("Duplicate constructor, " + c);
+            }
+            paramsToConstructor.put(c.getAssistedParameters(), c);
+        }
+
+        Map<Method, AssistedConstructor<?>> result = Maps.newHashMap();
+        for (Method method : factoryMethods) {
+            if (!method.getReturnType().isAssignableFrom(implementationType.getRawType())) {
+                throw newConfigurationException(
+                        "Return type of method %s is not assignable from %s", method, implementationType);
+            }
+
+            List<Type> parameterTypes = Lists.newArrayList();
+            for (TypeLiteral<?> parameterType : factoryType.getParameterTypes(method)) {
+                parameterTypes.add(parameterType.getType());
+            }
+            ParameterListKey methodParams = new ParameterListKey(parameterTypes);
+
+            if (!paramsToConstructor.containsKey(methodParams)) {
+                throw newConfigurationException(
+                        "%s has no @AssistInject constructor that takes the "
+                                + "@Assisted parameters %s in that order. @AssistInject constructors are %s",
+                        implementationType, methodParams, paramsToConstructor.values());
+            }
+
+            method.getParameterAnnotations();
+            for (Annotation[] parameterAnnotations : method.getParameterAnnotations()) {
+                for (Annotation parameterAnnotation : parameterAnnotations) {
+                    if (parameterAnnotation.annotationType() == Assisted.class) {
+                        throw newConfigurationException(
+                                "Factory method %s has an @Assisted parameter, which is incompatible with the"
+                                        + " deprecated @AssistedInject annotation. Please replace @AssistedInject with"
+                                        + " @Inject on the %s constructor.",
+                                method, implementationType);
+                    }
+                }
+            }
+
+            AssistedConstructor<?> matchingConstructor = paramsToConstructor.remove(methodParams);
+
+            result.put(method, matchingConstructor);
+        }
+        return result;
+    }
+
+    @Override
     public Set<Dependency<?>> getDependencies() {
         List<Dependency<?>> dependencies = Lists.newArrayList();
         for (AssistedConstructor<?> constructor : factoryMethodToConstructor.values()) {
@@ -313,9 +337,13 @@ public class FactoryProvider<F> implements Provider<F>, HasDependencies {
         return ImmutableSet.copyOf(dependencies);
     }
 
+    @Override
     public F get() {
-        InvocationHandler invocationHandler = new InvocationHandler() {
-            public Object invoke(Object proxy, Method method, Object[] creationArgs) throws Throwable {
+        InvocationHandler invocationHandler =
+                new InvocationHandler() {
+                    @Override
+                    public Object invoke(Object proxy, Method method, Object[] creationArgs)
+                            throws Throwable {
                         // pass methods from Object.class to the proxy
                         if (method.getDeclaringClass().equals(Object.class)) {
                             if ("equals".equals(method.getName())) {
@@ -335,8 +363,7 @@ public class FactoryProvider<F> implements Provider<F>, HasDependencies {
                     }
 
                     public Object[] gatherArgsForConstructor(
-                    AssistedConstructor<?> constructor,
-                    Object[] factoryArgs) {
+                            AssistedConstructor<?> constructor, Object[] factoryArgs) {
                         int numParams = constructor.getAllParameters().size();
                         int argPosition = 0;
                         Object[] result = new Object[numParams];
@@ -356,8 +383,9 @@ public class FactoryProvider<F> implements Provider<F>, HasDependencies {
 
         @SuppressWarnings("unchecked") // we imprecisely treat the class literal of T as a Class<T>
         Class<F> factoryRawType = (Class<F>) (Class<?>) factoryType.getRawType();
-        return factoryRawType.cast(Proxy.newProxyInstance(factoryRawType.getClassLoader(),
-                new Class[]{factoryRawType}, invocationHandler));
+        return factoryRawType.cast(
+                Proxy.newProxyInstance(
+                        factoryRawType.getClassLoader(), new Class<?>[] {factoryRawType}, invocationHandler));
     }
 
     @Override
@@ -374,4 +402,8 @@ public class FactoryProvider<F> implements Provider<F>, HasDependencies {
         return factoryType.equals(other.factoryType)
                 && implementationType.equals(other.implementationType);
     }
+
+    private static ConfigurationException newConfigurationException(String format, Object... args) {
+        return new ConfigurationException(ImmutableSet.of(new Message(Errors.format(format, args))));
+    }
 }

src/main/java/com/google/inject/assistedinject/FactoryProvider2.java

@@ -1,5 +1,9 @@
 package com.google.inject.assistedinject;
 
+import static com.google.common.base.Preconditions.checkState;
+import static com.google.common.collect.Iterables.getOnlyElement;
+
+import com.google.common.base.MoreObjects;
 import com.google.common.base.Objects;
 import com.google.common.collect.HashMultimap;
 import com.google.common.collect.ImmutableList;
@@ -35,11 +39,12 @@ import com.google.inject.spi.ProviderInstanceBinding;
 import com.google.inject.spi.ProviderWithExtensionVisitor;
 import com.google.inject.spi.Toolable;
 import com.google.inject.util.Providers;
-
 import java.lang.annotation.Annotation;
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.MethodType;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationHandler;
-import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 import java.lang.reflect.Proxy;
@@ -50,35 +55,46 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-import static com.google.common.base.Preconditions.checkState;
-import static com.google.common.collect.Iterables.getOnlyElement;
-
 /**
- * The newer implementation of factory provider. This implementation uses a child injector to
- * create values.
+ * The newer implementation of factory provider. This implementation uses a child injector to create
+ * values.
+ *
+ * @author jessewilson@google.com (Jesse Wilson)
+ * @author dtm@google.com (Daniel Martin)
+ * @author schmitt@google.com (Peter Schmitt)
+ * @author sameb@google.com (Sam Berlin)
  */
-final class FactoryProvider2<F> implements InvocationHandler,
-        ProviderWithExtensionVisitor<F>, HasDependencies, AssistedInjectBinding<F> {
+final class FactoryProvider2<F>
+        implements InvocationHandler,
+        ProviderWithExtensionVisitor<F>,
+        HasDependencies,
+        AssistedInjectBinding<F> {
 
-    /**
-     * A constant annotation to denote the return value, instead of creating a new one each time.
-     */
+    /** A constant annotation to denote the return value, instead of creating a new one each time. */
     static final Annotation RETURN_ANNOTATION = UniqueAnnotations.create();
 
     // use the logger under a well-known name, not FactoryProvider2
     static final Logger logger = Logger.getLogger(AssistedInject.class.getName());
 
     /**
-     * if a factory method parameter isn't annotated, it gets this annotation.
+     * A constant that determines if we allow fallback to reflection. Typically always true, but
+     * reflectively set to false in tests.
      */
-    static final Assisted DEFAULT_ANNOTATION = new Assisted() {
+    private static boolean allowLookupReflection = true;
+
+    /** if a factory method parameter isn't annotated, it gets this annotation. */
+    static final Assisted DEFAULT_ANNOTATION =
+            new Assisted() {
+                @Override
                 public String value() {
                     return "";
                 }
 
+                @Override
                 public Class<? extends Annotation> annotationType() {
                     return Assisted.class;
                 }
@@ -95,40 +111,117 @@ final class FactoryProvider2<F> implements InvocationHandler,
 
                 @Override
                 public String toString() {
-            return "@" + Assisted.class.getName() + "(value=)";
+                    return "@"
+                            + Assisted.class.getName()
+                            + "("
+                            + Annotations.memberValueString("value", "")
+                            + ")";
                 }
             };
-    /**
-     * Mapping from method to the data about how the method will be assisted.
-     */
+
+    /** All the data necessary to perform an assisted inject. */
+    private static class AssistData implements AssistedMethod {
+        /** the constructor the implementation is constructed with. */
+        final Constructor<?> constructor;
+        /** the return type in the factory method that the constructor is bound to. */
+        final Key<?> returnType;
+        /** the parameters in the factory method associated with this data. */
+        final ImmutableList<Key<?>> paramTypes;
+        /** the type of the implementation constructed */
+        final TypeLiteral<?> implementationType;
+
+        /** All non-assisted dependencies required by this method. */
+        final Set<Dependency<?>> dependencies;
+        /** The factory method associated with this data */
+        final Method factoryMethod;
+
+        /** true if {@link #isValidForOptimizedAssistedInject} returned true. */
+        final boolean optimized;
+        /** the list of optimized providers, empty if not optimized. */
+        final List<ThreadLocalProvider> providers;
+        /** used to perform optimized factory creations. */
+        volatile Binding<?> cachedBinding; // TODO: volatile necessary?
+
+        AssistData(
+                Constructor<?> constructor,
+                Key<?> returnType,
+                ImmutableList<Key<?>> paramTypes,
+                TypeLiteral<?> implementationType,
+                Method factoryMethod,
+                Set<Dependency<?>> dependencies,
+                boolean optimized,
+                List<ThreadLocalProvider> providers) {
+            this.constructor = constructor;
+            this.returnType = returnType;
+            this.paramTypes = paramTypes;
+            this.implementationType = implementationType;
+            this.factoryMethod = factoryMethod;
+            this.dependencies = dependencies;
+            this.optimized = optimized;
+            this.providers = providers;
+        }
+
+        @Override
+        public String toString() {
+            return MoreObjects.toStringHelper(getClass())
+                    .add("ctor", constructor)
+                    .add("return type", returnType)
+                    .add("param type", paramTypes)
+                    .add("implementation type", implementationType)
+                    .add("dependencies", dependencies)
+                    .add("factory method", factoryMethod)
+                    .add("optimized", optimized)
+                    .add("providers", providers)
+                    .add("cached binding", cachedBinding)
+                    .toString();
+        }
+
+        @Override
+        public Set<Dependency<?>> getDependencies() {
+            return dependencies;
+        }
+
+        @Override
+        public Method getFactoryMethod() {
+            return factoryMethod;
+        }
+
+        @Override
+        public Constructor<?> getImplementationConstructor() {
+            return constructor;
+        }
+
+        @Override
+        public TypeLiteral<?> getImplementationType() {
+            return implementationType;
+        }
+    }
+
+    /** Mapping from method to the data about how the method will be assisted. */
     private final ImmutableMap<Method, AssistData> assistDataByMethod;
-    /**
-     * Mapping from method to method handle, for generated default methods.
-     */
-    private final ImmutableMap<Method, MethodHandleWrapper> methodHandleByMethod;
-    /**
-     * the factory interface, implemented and provided
-     */
-    private final F factory;
-    /**
-     * The key that this is bound to.
-     */
-    private final Key<F> factoryKey;
-    /**
-     * The binding collector, for equality/hashing purposes.
-     */
-    private final BindingCollector collector;
-    /**
-     * the hosting injector, or null if we haven't been initialized yet
-     */
+
+    /** Mapping from method to method handle, for generated default methods. */
+    private final ImmutableMap<Method, MethodHandle> methodHandleByMethod;
+
+    /** the hosting injector, or null if we haven't been initialized yet */
     private Injector injector;
 
+    /** the factory interface, implemented and provided */
+    private final F factory;
+
+    /** The key that this is bound to. */
+    private final Key<F> factoryKey;
+
+    /** The binding collector, for equality/hashing purposes. */
+    private final BindingCollector collector;
+
     /**
      * @param factoryKey a key for a Java interface that defines one or more create methods.
-     * @param collector  binding configuration that maps method return types to
-     *                   implementation types.
+     * @param collector binding configuration that maps method return types to implementation types.
+     * @param userLookups user provided lookups, optional.
      */
-    FactoryProvider2(Key<F> factoryKey, BindingCollector collector) {
+    FactoryProvider2(
+            Key<F> factoryKey, BindingCollector collector, MethodHandles.Lookup userLookups) {
         this.factoryKey = factoryKey;
         this.collector = collector;
 
@@ -148,6 +241,11 @@ final class FactoryProvider2<F> implements InvocationHandler,
             ImmutableMap.Builder<Method, AssistData> assistDataBuilder = ImmutableMap.builder();
             // TODO: also grab methods from superinterfaces
             for (Method method : factoryRawType.getMethods()) {
+                // Skip static methods
+                if (Modifier.isStatic(method.getModifiers())) {
+                    continue;
+                }
+
                 // Skip default methods that java8 may have created.
                 if (isDefault(method) && (method.isBridge() || method.isSynthetic())) {
                     // Even synthetic default methods need the return type validation...
@@ -161,7 +259,8 @@ final class FactoryProvider2<F> implements InvocationHandler,
                 TypeLiteral<?> returnTypeLiteral = factoryType.getReturnType(method);
                 Key<?> returnType;
                 try {
-                    returnType = Annotations.getKey(returnTypeLiteral, method, method.getAnnotations(), errors);
+                    returnType =
+                            Annotations.getKey(returnTypeLiteral, method, method.getAnnotations(), errors);
                 } catch (ConfigurationException ce) {
                     // If this was an error due to returnTypeLiteral not being specified, rephrase
                     // it as our factory not being specified, so it makes more sense to users.
@@ -181,7 +280,8 @@ final class FactoryProvider2<F> implements InvocationHandler,
                     Class<?> underlylingType = paramKey.getTypeLiteral().getRawType();
                     if (underlylingType.equals(Provider.class)
                             || underlylingType.equals(javax.inject.Provider.class)) {
-                        errors.addMessage("A Provider may not be a type in a factory method of an AssistedInject."
+                        errors.addMessage(
+                                "A Provider may not be a type in a factory method of an AssistedInject."
                                         + "\n  Offending instance is parameter [%s] with key [%s] on method [%s]",
                                 p, paramKey, method);
                     }
@@ -197,7 +297,8 @@ final class FactoryProvider2<F> implements InvocationHandler,
                 Class<? extends Annotation> scope =
                         Annotations.findScopeAnnotation(errors, implementation.getRawType());
                 if (scope != null) {
-                    errors.addMessage("Found scope annotation [%s] on implementation class "
+                    errors.addMessage(
+                            "Found scope annotation [%s] on implementation class "
                                     + "[%s] of AssistedInject factory [%s].\nThis is not allowed, please"
                                     + " remove the scope annotation.",
                             scope, implementation.getRawType(), factoryType);
@@ -206,7 +307,8 @@ final class FactoryProvider2<F> implements InvocationHandler,
                 InjectionPoint ctorInjectionPoint;
                 try {
                     ctorInjectionPoint =
-                            findMatchingConstructorInjectionPoint(method, returnType, implementation, immutableParamList);
+                            findMatchingConstructorInjectionPoint(
+                                    method, returnType, implementation, immutableParamList);
                 } catch (ErrorsException ee) {
                     errors.merge(ee.getErrors());
                     continue;
@@ -230,7 +332,9 @@ final class FactoryProvider2<F> implements InvocationHandler,
                     optimized = true;
                 }
 
-                AssistData data = new AssistData(constructor,
+                AssistData data =
+                        new AssistData(
+                                constructor,
                                 returnType,
                                 immutableParamList,
                                 implementation,
@@ -241,25 +345,61 @@ final class FactoryProvider2<F> implements InvocationHandler,
                 assistDataBuilder.put(method, data);
             }
 
-            factory = factoryRawType.cast(Proxy.newProxyInstance(
-                    factoryRawType.getClassLoader(), new Class<?>[]{factoryRawType}, this));
+            factory =
+                    factoryRawType.cast(
+                            Proxy.newProxyInstance(
+                                    factoryRawType.getClassLoader(), new Class<?>[] {factoryRawType}, this));
 
             // Now go back through default methods. Try to use MethodHandles to make things
             // work.  If that doesn't work, fallback to trying to find compatible method
             // signatures.
             Map<Method, AssistData> dataSoFar = assistDataBuilder.build();
-            ImmutableMap.Builder<Method, MethodHandleWrapper> methodHandleBuilder = ImmutableMap.builder();
+            ImmutableMap.Builder<Method, MethodHandle> methodHandleBuilder = ImmutableMap.builder();
+            boolean warnedAboutUserLookups = false;
             for (Map.Entry<String, Method> entry : defaultMethods.entries()) {
+                if (!warnedAboutUserLookups
+                        && userLookups == null
+                        && !Modifier.isPublic(factory.getClass().getModifiers())) {
+                    warnedAboutUserLookups = true;
+                    logger.log(
+                            Level.WARNING,
+                            "AssistedInject factory {0} is non-public and has javac-generated default methods. "
+                                    + " Please pass a `MethodHandles.lookups()` with"
+                                    + " FactoryModuleBuilder.withLookups when using this factory so that Guice can"
+                                    + " properly call the default methods. Guice will try to work around the"
+                                    + " problem, but doing so requires reflection into the JDK and may break at any"
+                                    + " time.",
+                            new Object[] {factoryType});
+                }
+
                 Method defaultMethod = entry.getValue();
-                MethodHandleWrapper handle = MethodHandleWrapper.create(defaultMethod, factory);
+                MethodHandle handle = null;
+                try {
+                    // Note: this can return null if we fallback to reflecting the private lookup cxtor and it
+                    // fails. In that case, we try the super hacky workaround below (w/ 'foundMatch').
+                    // It can throw an exception if we're not doing private reflection, or if unreflectSpecial
+                    // _still_ fails.
+                    handle = superMethodHandle(defaultMethod, factory, userLookups);
+                } catch (ReflectiveOperationException roe) {
+                    errors.addMessage(
+                            new Message(
+                                    "Unable to use factory "
+                                            + factoryRawType.getName()
+                                            + ". Did you call FactoryModuleBuilder.withLookups(MethodHandles.lookups())"
+                                            + " (with a lookups that has access to the factory)?"));
+                    continue;
+                }
+
                 if (handle != null) {
                     methodHandleBuilder.put(defaultMethod, handle);
                 } else {
+                    // TODO: remove this workaround when Java8 support is dropped
                     boolean foundMatch = false;
                     for (Method otherMethod : otherMethods.get(defaultMethod.getName())) {
                         if (dataSoFar.containsKey(otherMethod) && isCompatible(defaultMethod, otherMethod)) {
                             if (foundMatch) {
-                                errors.addMessage("Generated default method %s with parameters %s is"
+                                errors.addMessage(
+                                        "Generated default method %s with parameters %s is"
                                                 + " signature-compatible with more than one non-default method."
                                                 + " Unable to create factory. As a workaround, remove the override"
                                                 + " so javac stops generating a default method.",
@@ -276,7 +416,8 @@ final class FactoryProvider2<F> implements InvocationHandler,
                 }
             }
 
-            // If we generated any errors (from finding matching constructors, for instance), throw an exception.
+            // If we generated any errors (from finding matching constructors, for instance), throw an
+            // exception.
             if (errors.hasErrors()) {
                 throw errors.toException();
             }
@@ -296,23 +437,6 @@ final class FactoryProvider2<F> implements InvocationHandler,
                 == Modifier.PUBLIC;
     }
 
-    /**
-     * Returns true if {@code thrown} can be thrown by {@code invoked} without wrapping.
-     */
-    static boolean canRethrow(Method invoked, Throwable thrown) {
-        if (thrown instanceof Error || thrown instanceof RuntimeException) {
-            return true;
-        }
-
-        for (Class<?> declared : invoked.getExceptionTypes()) {
-            if (declared.isInstance(thrown)) {
-                return true;
-            }
-        }
-
-        return false;
-    }
-
     private boolean isCompatible(Method src, Method dst) {
         if (!src.getReturnType().isAssignableFrom(dst.getReturnType())) {
             return false;
@@ -330,32 +454,37 @@ final class FactoryProvider2<F> implements InvocationHandler,
         return true;
     }
 
+    @Override
     public F get() {
         return factory;
     }
 
+    @Override
     public Set<Dependency<?>> getDependencies() {
-        Set<Dependency<?>> combinedDeps = new HashSet<Dependency<?>>();
+        Set<Dependency<?>> combinedDeps = new HashSet<>();
         for (AssistData data : assistDataByMethod.values()) {
             combinedDeps.addAll(data.dependencies);
         }
         return ImmutableSet.copyOf(combinedDeps);
     }
 
+    @Override
     public Key<F> getKey() {
         return factoryKey;
     }
 
     // Safe cast because values are typed to AssistedData, which is an AssistedMethod, and
     // the collection is immutable.
+    @Override
     @SuppressWarnings("unchecked")
     public Collection<AssistedMethod> getAssistedMethods() {
         return (Collection<AssistedMethod>) (Collection<?>) assistDataByMethod.values();
     }
 
+    @Override
     @SuppressWarnings("unchecked")
-    public <T, V> V acceptExtensionVisitor(BindingTargetVisitor<T, V> visitor,
-                                           ProviderInstanceBinding<? extends T> binding) {
+    public <T, V> V acceptExtensionVisitor(
+            BindingTargetVisitor<T, V> visitor, ProviderInstanceBinding<? extends T> binding) {
         if (visitor instanceof AssistedInjectTargetVisitor) {
             return ((AssistedInjectTargetVisitor<T, V>) visitor).visit((AssistedInjectBinding<T>) this);
         }
@@ -365,7 +494,8 @@ final class FactoryProvider2<F> implements InvocationHandler,
     private void validateFactoryReturnType(Errors errors, Class<?> returnType, Class<?> factoryType) {
         if (Modifier.isPublic(factoryType.getModifiers())
                 && !Modifier.isPublic(returnType.getModifiers())) {
-            errors.addMessage("%s is public, but has a method that returns a non-public type: %s. "
+            errors.addMessage(
+                    "%s is public, but has a method that returns a non-public type: %s. "
                             + "Due to limitations with java.lang.reflect.Proxy, this is not allowed. "
                             + "Please either make the factory non-public or the return type public.",
                     factoryType, returnType);
@@ -379,8 +509,8 @@ final class FactoryProvider2<F> implements InvocationHandler,
     private boolean isTypeNotSpecified(TypeLiteral<?> typeLiteral, ConfigurationException ce) {
         Collection<Message> messages = ce.getErrorMessages();
         if (messages.size() == 1) {
-            Message msg = Iterables.getOnlyElement(
-                    new Errors().keyNotFullySpecified(typeLiteral).getMessages());
+            Message msg =
+                    Iterables.getOnlyElement(new Errors().keyNotFullySpecified(typeLiteral).getMessages());
             return msg.getMessage().equals(Iterables.getOnlyElement(messages).getMessage());
         } else {
             return false;
@@ -390,9 +520,9 @@ final class FactoryProvider2<F> implements InvocationHandler,
     /**
      * Finds a constructor suitable for the method. If the implementation contained any constructors
      * marked with {@link AssistedInject}, this requires all {@link Assisted} parameters to exactly
-     * match the parameters (in any order) listed in the method.  Otherwise, if no
-     * {@link AssistedInject} constructors exist, this will default to looking for an
-     * {@literal @}{@link Inject} constructor.
+     * match the parameters (in any order) listed in the method. Otherwise, if no {@link
+     * AssistedInject} constructors exist, this will default to looking for an {@literal @}{@link
+     * Inject} constructor.
      */
     private <T> InjectionPoint findMatchingConstructorInjectionPoint(
             Method method, Key<?> returnType, TypeLiteral<T> implementation, List<Key<?>> paramList)
@@ -428,8 +558,7 @@ final class FactoryProvider2<F> implements InvocationHandler,
                 anyAssistedInjectConstructors = true;
                 if (constructorHasMatchingParams(implementation, constructor, paramList, errors)) {
                     if (matchingConstructor != null) {
-                        errors
-                                .addMessage(
+                        errors.addMessage(
                                 "%s has more than one constructor annotated with @AssistedInject"
                                         + " that matches the parameters in method %s.  Unable to create "
                                         + "AssistedInject factory.",
@@ -443,7 +572,7 @@ final class FactoryProvider2<F> implements InvocationHandler,
         }
 
         if (!anyAssistedInjectConstructors) {
-            // If none existed, use @Inject.
+            // If none existed, use @Inject or a no-arg constructor.
             try {
                 return InjectionPoint.forConstructorOf(implementation);
             } catch (ConfigurationException e) {
@@ -455,7 +584,8 @@ final class FactoryProvider2<F> implements InvocationHandler,
             if (matchingConstructor != null) {
                 // safe because we got the constructor from this implementation.
                 @SuppressWarnings("unchecked")
-                InjectionPoint ip = InjectionPoint.forConstructor(
+                InjectionPoint ip =
+                        InjectionPoint.forConstructor(
                                 (Constructor<? super T>) matchingConstructor, implementation);
                 return ip;
             } else {
@@ -469,21 +599,19 @@ final class FactoryProvider2<F> implements InvocationHandler,
     }
 
     /**
-     * Matching logic for constructors annotated with AssistedInject.
-     * This returns true if and only if all @Assisted parameters in the
-     * constructor exactly match (in any order) all @Assisted parameters
-     * the method's parameter.
+     * Matching logic for constructors annotated with AssistedInject. This returns true if and only if
+     * all @Assisted parameters in the constructor exactly match (in any order) all @Assisted
+     * parameters the method's parameter.
      */
-    private boolean constructorHasMatchingParams(TypeLiteral<?> type,
-                                                 Constructor<?> constructor, List<Key<?>> paramList, Errors errors)
+    private boolean constructorHasMatchingParams(
+            TypeLiteral<?> type, Constructor<?> constructor, List<Key<?>> paramList, Errors errors)
             throws ErrorsException {
         List<TypeLiteral<?>> params = type.getParameterTypes(constructor);
         Annotation[][] paramAnnotations = constructor.getParameterAnnotations();
         int p = 0;
         List<Key<?>> constructorKeys = Lists.newArrayList();
         for (TypeLiteral<?> param : params) {
-            Key<?> paramKey = Annotations.getKey(param, constructor, paramAnnotations[p++],
-                    errors);
+            Key<?> paramKey = Annotations.getKey(param, constructor, paramAnnotations[p++], errors);
             constructorKeys.add(paramKey);
         }
         // Require that every key exist in the constructor to match up exactly.
@@ -503,10 +631,9 @@ final class FactoryProvider2<F> implements InvocationHandler,
         return true;
     }
 
-    /**
-     * Calculates all dependencies required by the implementation and constructor.
-     */
-    private Set<Dependency<?>> getDependencies(InjectionPoint ctorPoint, TypeLiteral<?> implementation) {
+    /** Calculates all dependencies required by the implementation and constructor. */
+    private Set<Dependency<?>> getDependencies(
+            InjectionPoint ctorPoint, TypeLiteral<?> implementation) {
         ImmutableSet.Builder<Dependency<?>> builder = ImmutableSet.builder();
         builder.addAll(ctorPoint.getDependencies());
         if (!implementation.getRawType().isInterface()) {
@@ -517,9 +644,7 @@ final class FactoryProvider2<F> implements InvocationHandler,
         return builder.build();
     }
 
-    /**
-     * Return all non-assisted dependencies.
-     */
+    /** Return all non-assisted dependencies. */
     private Set<Dependency<?>> removeAssistedDeps(Set<Dependency<?>> deps) {
         ImmutableSet.Builder<Dependency<?>> builder = ImmutableSet.builder();
         for (Dependency<?> dep : deps) {
@@ -537,8 +662,8 @@ final class FactoryProvider2<F> implements InvocationHandler,
      * the assisted bindings are immediately provided. This looks for hints that the values may be
      * lazily retrieved, by looking for injections of Injector or a Provider for the assisted values.
      */
-    private boolean isValidForOptimizedAssistedInject(Set<Dependency<?>> dependencies,
-                                                      Class<?> implementation, TypeLiteral<?> factoryType) {
+    private boolean isValidForOptimizedAssistedInject(
+            Set<Dependency<?>> dependencies, Class<?> implementation, TypeLiteral<?> factoryType) {
         Set<Dependency<?>> badDeps = null; // optimization: create lazily
         for (Dependency<?> dep : dependencies) {
             if (isInjectorOrAssistedProvider(dep)) {
@@ -549,45 +674,57 @@ final class FactoryProvider2<F> implements InvocationHandler,
             }
         }
         if (badDeps != null && !badDeps.isEmpty()) {
-            logger.log(Level.WARNING, "AssistedInject factory {0} will be slow "
+            logger.log(
+                    Level.WARNING,
+                    "AssistedInject factory {0} will be slow "
                             + "because {1} has assisted Provider dependencies or injects the Injector. "
                             + "Stop injecting @Assisted Provider<T> (instead use @Assisted T) "
                             + "or Injector to speed things up. (It will be a ~6500% speed bump!)  "
                             + "The exact offending deps are: {2}",
-                    new Object[]{factoryType, implementation, badDeps});
+                    new Object[] {factoryType, implementation, badDeps});
             return false;
         }
         return true;
     }
 
     /**
-     * Returns true if the dependency is for {@link Injector} or if the dependency
-     * is a {@link Provider} for a parameter that is {@literal @}{@link Assisted}.
+     * Returns true if the dependency is for {@link Injector} or if the dependency is a {@link
+     * Provider} for a parameter that is {@literal @}{@link Assisted}.
      */
     private boolean isInjectorOrAssistedProvider(Dependency<?> dependency) {
         Class<?> annotationType = dependency.getKey().getAnnotationType();
         if (annotationType != null && annotationType.equals(Assisted.class)) { // If it's assisted..
-            if (dependency.getKey().getTypeLiteral().getRawType().equals(Provider.class)) { // And a Provider...
+            if (dependency
+                    .getKey()
+                    .getTypeLiteral()
+                    .getRawType()
+                    .equals(Provider.class)) { // And a Provider...
                 return true;
             }
-        } else if (dependency.getKey().getTypeLiteral().getRawType().equals(Injector.class)) { // If it's the Injector...
+        } else if (dependency
+                .getKey()
+                .getTypeLiteral()
+                .getRawType()
+                .equals(Injector.class)) { // If it's the Injector...
             return true;
         }
         return false;
     }
 
     /**
-     * Returns a key similar to {@code key}, but with an {@literal @}Assisted binding annotation.
-     * This fails if another binding annotation is clobbered in the process. If the key already has
-     * the {@literal @}Assisted annotation, it is returned as-is to preserve any String value.
+     * Returns a key similar to {@code key}, but with an {@literal @}Assisted binding annotation. This
+     * fails if another binding annotation is clobbered in the process. If the key already has the
+     * {@literal @}Assisted annotation, it is returned as-is to preserve any String value.
      */
     private <T> Key<T> assistKey(Method method, Key<T> key, Errors errors) throws ErrorsException {
         if (key.getAnnotationType() == null) {
-            return Key.get(key.getTypeLiteral(), DEFAULT_ANNOTATION);
+            return key.withAnnotation(DEFAULT_ANNOTATION);
         } else if (key.getAnnotationType() == Assisted.class) {
             return key;
         } else {
-            errors.withSource(method).addMessage(
+            errors
+                    .withSource(method)
+                    .addMessage(
                             "Only @Assisted is allowed for factory parameters, but found @%s",
                             key.getAnnotationType());
             throw errors.toException();
@@ -595,14 +732,17 @@ final class FactoryProvider2<F> implements InvocationHandler,
     }
 
     /**
-     * At injector-creation time, we initialize the invocation handler. At this time we make sure
-     * all factory methods will be able to build the target types.
+     * At injector-creation time, we initialize the invocation handler. At this time we make sure all
+     * factory methods will be able to build the target types.
      */
     @Inject
     @Toolable
     void initialize(Injector injector) {
         if (this.injector != null) {
-            throw new ConfigurationException(ImmutableList.of(new Message(FactoryProvider2.class,
+            throw new ConfigurationException(
+                    ImmutableList.of(
+                            new Message(
+                                    FactoryProvider2.class,
                                     "Factories.create() factories may only be used in one Injector!")));
         }
 
@@ -618,7 +758,8 @@ final class FactoryProvider2<F> implements InvocationHandler,
             } else {
                 args = null; // won't be used -- instead will bind to data.providers.
             }
-            getBindingFromNewInjector(method, args, data); // throws if the binding isn't properly configured
+            getBindingFromNewInjector(
+                    method, args, data); // throws if the binding isn't properly configured
         }
     }
 
@@ -627,7 +768,8 @@ final class FactoryProvider2<F> implements InvocationHandler,
      */
     public Binding<?> getBindingFromNewInjector(
             final Method method, final Object[] args, final AssistData data) {
-        checkState(injector != null,
+        checkState(
+                injector != null,
                 "Factories.create() factories cannot be used until they're initialized by Guice.");
 
         final Key<?> returnType = data.returnType;
@@ -635,17 +777,21 @@ final class FactoryProvider2<F> implements InvocationHandler,
         // We ignore any pre-existing binding annotation.
         final Key<?> returnKey = Key.get(returnType.getTypeLiteral(), RETURN_ANNOTATION);
 
-        Module assistedModule = new AbstractModule() {
+        Module assistedModule =
+                new AbstractModule() {
                     @Override
                     @SuppressWarnings({
-                    "unchecked", "rawtypes"}) // raw keys are necessary for the args array and return value
+                            "unchecked",
+                            "rawtypes"
+                    }) // raw keys are necessary for the args array and return value
                     protected void configure() {
                         Binder binder = binder().withSource(method);
 
                         int p = 0;
                         if (!data.optimized) {
                             for (Key<?> paramKey : data.paramTypes) {
-                        // Wrap in a Provider to cover null, and to prevent Guice from injecting the parameter
+                                // Wrap in a Provider to cover null, and to prevent Guice from injecting the
+                                // parameter
                                 binder.bind((Key) paramKey).toProvider(Providers.of(args[p++]));
                             }
                         } else {
@@ -660,7 +806,8 @@ final class FactoryProvider2<F> implements InvocationHandler,
                         // but if it isn't, we'll end up throwing a fairly good error
                         // message for the user.
                         if (constructor != null) {
-                    binder.bind(returnKey)
+                            binder
+                                    .bind(returnKey)
                                     .toConstructor(constructor, (TypeLiteral) data.implementationType)
                                     .in(Scopes.NO_SCOPE); // make sure we erase any scope on the implementation type
                         }
@@ -680,6 +827,7 @@ final class FactoryProvider2<F> implements InvocationHandler,
      * When a factory method is invoked, we create a child injector that binds all parameters, then
      * use that to get an instance of the return type.
      */
+    @Override
     public Object invoke(Object proxy, final Method method, final Object[] args) throws Throwable {
         // If we setup a method handle earlier for this method, call it.
         // This is necessary for default methods that java8 creates, so we
@@ -748,93 +896,19 @@ final class FactoryProvider2<F> implements InvocationHandler,
         return factoryKey.equals(other.factoryKey) && Objects.equal(collector, other.collector);
     }
 
-    /**
-     * All the data necessary to perform an assisted inject.
-     */
-    private static class AssistData implements AssistedMethod {
-        /**
-         * the constructor the implementation is constructed with.
-         */
-        final Constructor<?> constructor;
-        /**
-         * the return type in the factory method that the constructor is bound to.
-         */
-        final Key<?> returnType;
-        /**
-         * the parameters in the factory method associated with this data.
-         */
-        final ImmutableList<Key<?>> paramTypes;
-        /**
-         * the type of the implementation constructed
-         */
-        final TypeLiteral<?> implementationType;
-
-        /**
-         * All non-assisted dependencies required by this method.
-         */
-        final Set<Dependency<?>> dependencies;
-        /**
-         * The factory method associated with this data
-         */
-        final Method factoryMethod;
-
-        /**
-         * true if {@link #isValidForOptimizedAssistedInject} returned true.
-         */
-        final boolean optimized;
-        /**
-         * the list of optimized providers, empty if not optimized.
-         */
-        final List<ThreadLocalProvider> providers;
-        /**
-         * used to perform optimized factory creations.
-         */
-        volatile Binding<?> cachedBinding; // TODO: volatile necessary?
-
-        AssistData(Constructor<?> constructor, Key<?> returnType, ImmutableList<Key<?>> paramTypes,
-                   TypeLiteral<?> implementationType, Method factoryMethod,
-                   Set<Dependency<?>> dependencies,
-                   boolean optimized, List<ThreadLocalProvider> providers) {
-            this.constructor = constructor;
-            this.returnType = returnType;
-            this.paramTypes = paramTypes;
-            this.implementationType = implementationType;
-            this.factoryMethod = factoryMethod;
-            this.dependencies = dependencies;
-            this.optimized = optimized;
-            this.providers = providers;
+    /** Returns true if {@code thrown} can be thrown by {@code invoked} without wrapping. */
+    static boolean canRethrow(Method invoked, Throwable thrown) {
+        if (thrown instanceof Error || thrown instanceof RuntimeException) {
+            return true;
         }
 
-        @Override
-        public String toString() {
-            return Objects.toStringHelper(getClass())
-                    .add("ctor", constructor)
-                    .add("return type", returnType)
-                    .add("param type", paramTypes)
-                    .add("implementation type", implementationType)
-                    .add("dependencies", dependencies)
-                    .add("factory method", factoryMethod)
-                    .add("optimized", optimized)
-                    .add("providers", providers)
-                    .add("cached binding", cachedBinding)
-                    .toString();
+        for (Class<?> declared : invoked.getExceptionTypes()) {
+            if (declared.isInstance(thrown)) {
+                return true;
+            }
         }
 
-        public Set<Dependency<?>> getDependencies() {
-            return dependencies;
-        }
-
-        public Method getFactoryMethod() {
-            return factoryMethod;
-        }
-
-        public Constructor<?> getImplementationConstructor() {
-            return constructor;
-        }
-
-        public TypeLiteral<?> getImplementationType() {
-            return implementationType;
-        }
+        return false;
     }
 
     // not <T> because we'll never know and this is easier than suppressing warnings.
@@ -847,86 +921,106 @@ final class FactoryProvider2<F> implements InvocationHandler,
         }
     }
 
-    /**
-     * Wrapper around MethodHandles/MethodHandle, so we can compile+run on java6.
-     */
-    private static class MethodHandleWrapper {
-        static final int ALL_MODES = Modifier.PRIVATE
-                | Modifier.STATIC /* package */
-                | Modifier.PUBLIC
-                | Modifier.PROTECTED;
+    private static MethodHandle superMethodHandle(
+            Method method, Object proxy, MethodHandles.Lookup userLookups)
+            throws ReflectiveOperationException {
+        MethodHandles.Lookup lookup = userLookups == null ? MethodHandles.lookup() : userLookups;
+        MethodHandle handle = SUPER_METHOD_LOOKUP.get().superMethodHandle(method, lookup);
+        return handle != null ? handle.bindTo(proxy) : null;
+    }
 
-        static final Method unreflectSpecial;
-        static final Method bindTo;
-        static final Method invokeWithArguments;
-        static final Constructor<?> lookupCxtor;
-        static final boolean valid;
+    // begin by trying unreflectSpecial to find super method handles; this should work on Java14+
+    private static final AtomicReference<SuperMethodLookup> SUPER_METHOD_LOOKUP =
+            new AtomicReference<>(SuperMethodLookup.UNREFLECT_SPECIAL);
 
-        static {
-            Method unreflectSpecialTmp = null;
-            Method bindToTmp = null;
-            Method invokeWithArgumentsTmp = null;
-            boolean validTmp = false;
-            Constructor<?> lookupCxtorTmp = null;
+    private static enum SuperMethodLookup {
+        UNREFLECT_SPECIAL {
+            @Override
+            MethodHandle superMethodHandle(Method method, MethodHandles.Lookup lookup)
+                    throws ReflectiveOperationException {
                 try {
-                Class<?> lookupClass = Class.forName("java.lang.invoke.MethodHandles$Lookup");
-                unreflectSpecialTmp = lookupClass.getMethod("unreflectSpecial", Method.class, Class.class);
-                Class<?> methodHandleClass = Class.forName("java.lang.invoke.MethodHandle");
-                bindToTmp = methodHandleClass.getMethod("bindTo", Object.class);
-                invokeWithArgumentsTmp = methodHandleClass.getMethod("invokeWithArguments", Object[].class);
-                lookupCxtorTmp = lookupClass.getDeclaredConstructor(Class.class, int.class);
-                lookupCxtorTmp.setAccessible(true);
-                validTmp = true;
-            } catch (Exception invalid) {
-                // Ignore the exception, store the values & exit early in create(..) if invalid.
+                    return lookup.unreflectSpecial(method, method.getDeclaringClass());
+                } catch (ReflectiveOperationException e) {
+                    // fall back to findSpecial which should work on Java9+; use that for future lookups
+                    SUPER_METHOD_LOOKUP.compareAndSet(this, FIND_SPECIAL);
+                    return SUPER_METHOD_LOOKUP.get().superMethodHandle(method, lookup);
                 }
-
-            // Store refs to later.
-            valid = validTmp;
-            unreflectSpecial = unreflectSpecialTmp;
-            bindTo = bindToTmp;
-            invokeWithArguments = invokeWithArgumentsTmp;
-            lookupCxtor = lookupCxtorTmp;
-        }
-
-        final Object handle;
-
-        MethodHandleWrapper(Object handle) {
-            this.handle = handle;
-        }
-
-        static MethodHandleWrapper create(Method method, Object proxy) {
-            if (!valid) {
-                return null;
             }
+        },
+        FIND_SPECIAL {
+            @Override
+            MethodHandle superMethodHandle(Method method, MethodHandles.Lookup lookup)
+                    throws ReflectiveOperationException {
                 try {
                     Class<?> declaringClass = method.getDeclaringClass();
-                // Note: this isn't a public API, but we need to use it in order to call default methods.
-                Object lookup = lookupCxtor.newInstance(declaringClass, ALL_MODES);
-                method.setAccessible(true);
-                // These are part of the public API, but we use reflection since we run on java6
-                // and they were introduced in java7.
-                lookup = unreflectSpecial.invoke(lookup, method, declaringClass);
-                Object handle = bindTo.invoke(lookup, proxy);
-                return new MethodHandleWrapper(handle);
-            } catch (InvocationTargetException ite) {
-                return null;
-            } catch (IllegalAccessException iae) {
-                return null;
-            } catch (InstantiationException ie) {
-                return null;
+                    // use findSpecial to workaround https://bugs.openjdk.java.net/browse/JDK-8209005
+                    return lookup.findSpecial(
+                            declaringClass,
+                            method.getName(),
+                            MethodType.methodType(method.getReturnType(), method.getParameterTypes()),
+                            declaringClass);
+                } catch (ReflectiveOperationException e) {
+                    if (!allowLookupReflection) {
+                        throw e;
+                    }
+                    // fall back to private Lookup which should work on Java8; use that for future lookups
+                    SUPER_METHOD_LOOKUP.compareAndSet(this, PRIVATE_LOOKUP);
+                    return SUPER_METHOD_LOOKUP.get().superMethodHandle(method, lookup);
                 }
             }
-
-        Object invokeWithArguments(Object[] args) throws Exception {
-            // We must cast the args to an object so the Object[] is the first param,
-            // as opposed to each individual varargs param.
-            return invokeWithArguments.invoke(handle, (Object) args);
-        }
-
+        },
+        PRIVATE_LOOKUP {
             @Override
-        public String toString() {
-            return handle.toString();
+            MethodHandle superMethodHandle(Method method, MethodHandles.Lookup unused)
+                    throws ReflectiveOperationException {
+                return PrivateLookup.superMethodHandle(method);
+            }
+        };
+
+        abstract MethodHandle superMethodHandle(Method method, MethodHandles.Lookup lookup)
+                throws ReflectiveOperationException;
+    };
+
+    // Note: this isn't a public API, but we need to use it in order to call default methods on (or
+    // with) non-public types. If it doesn't exist, the code falls back to a less precise check.
+    static class PrivateLookup {
+        PrivateLookup() {}
+
+        private static final int ALL_MODES =
+                Modifier.PRIVATE | Modifier.STATIC /* package */ | Modifier.PUBLIC | Modifier.PROTECTED;
+
+        private static final Constructor<MethodHandles.Lookup> privateLookupCxtor =
+                findPrivateLookupCxtor();
+
+        private static Constructor<MethodHandles.Lookup> findPrivateLookupCxtor() {
+            try {
+                Constructor<MethodHandles.Lookup> cxtor;
+                try {
+                    cxtor = MethodHandles.Lookup.class.getDeclaredConstructor(Class.class, int.class);
+                } catch (NoSuchMethodException ignored) {
+                    cxtor =
+                            MethodHandles.Lookup.class.getDeclaredConstructor(
+                                    Class.class, Class.class, int.class);
+                }
+                cxtor.setAccessible(true);
+                return cxtor;
+            } catch (ReflectiveOperationException | SecurityException e) {
+                return null;
+            }
+        }
+
+        static MethodHandle superMethodHandle(Method method) throws ReflectiveOperationException {
+            if (privateLookupCxtor == null) {
+                return null; // fall back to assistDataBuilder workaround
+            }
+            Class<?> declaringClass = method.getDeclaringClass();
+            MethodHandles.Lookup lookup;
+            if (privateLookupCxtor.getParameterCount() == 2) {
+                lookup = privateLookupCxtor.newInstance(declaringClass, ALL_MODES);
+            } else {
+                lookup = privateLookupCxtor.newInstance(declaringClass, null, ALL_MODES);
+            }
+            return lookup.unreflectSpecial(method, declaringClass);
         }
     }
 }

src/main/java/com/google/inject/binder/LinkedBindingBuilder.java

@@ -51,20 +51,17 @@ public interface LinkedBindingBuilder<T> extends ScopedBindingBuilder {
     /**
      * See the EDSL examples at {@link com.google.inject.Binder}.
      */
-    ScopedBindingBuilder toProvider(
-            Class<? extends javax.inject.Provider<? extends T>> providerType);
+    ScopedBindingBuilder toProvider(Class<? extends javax.inject.Provider<? extends T>> providerType);
 
     /**
      * See the EDSL examples at {@link com.google.inject.Binder}.
      */
-    ScopedBindingBuilder toProvider(
-            TypeLiteral<? extends javax.inject.Provider<? extends T>> providerType);
+    ScopedBindingBuilder toProvider(TypeLiteral<? extends javax.inject.Provider<? extends T>> providerType);
 
     /**
      * See the EDSL examples at {@link com.google.inject.Binder}.
      */
-    ScopedBindingBuilder toProvider(
-            Key<? extends javax.inject.Provider<? extends T>> providerKey);
+    ScopedBindingBuilder toProvider(Key<? extends javax.inject.Provider<? extends T>> providerKey);
 
     /**
      * See the EDSL examples at {@link com.google.inject.Binder}.
@@ -74,6 +71,5 @@ public interface LinkedBindingBuilder<T> extends ScopedBindingBuilder {
     /**
      * See the EDSL examples at {@link com.google.inject.Binder}.
      */
-    <S extends T> ScopedBindingBuilder toConstructor(
-            Constructor<S> constructor, TypeLiteral<? extends S> type);
+    <S extends T> ScopedBindingBuilder toConstructor(Constructor<S> constructor, TypeLiteral<? extends S> type);
 }

src/main/java/com/google/inject/internal/AbstractBindingBuilder.java

@@ -18,14 +18,14 @@ import static com.google.common.base.Preconditions.checkNotNull;
 public abstract class AbstractBindingBuilder<T> {
 
     public static final String IMPLEMENTATION_ALREADY_SET = "Implementation is set more than once.";
-    public static final String SINGLE_INSTANCE_AND_SCOPE
-            = "Setting the scope is not permitted when binding to a single instance.";
+    public static final String SINGLE_INSTANCE_AND_SCOPE =
+            "Setting the scope is not permitted when binding to a single instance.";
     public static final String SCOPE_ALREADY_SET = "Scope is set more than once.";
-    public static final String BINDING_TO_NULL = "Binding to null instances is not allowed. "
-            + "Use toProvider(Providers.of(null)) if this is your intended behaviour.";
+    public static final String BINDING_TO_NULL = "Binding to null instances is not allowed. " +
+            "Use toProvider(Providers.of(null)) if this is your intended behaviour.";
     public static final String CONSTANT_VALUE_ALREADY_SET = "Constant value is set more than once.";
-    public static final String ANNOTATION_ALREADY_SPECIFIED
-            = "More than one annotation is specified for this binding.";
+    public static final String ANNOTATION_ALREADY_SPECIFIED =
+            "More than one annotation is specified for this binding.";
 
     protected static final Key<?> NULL_KEY = Key.get(Void.class);
     protected final Binder binder;
@@ -37,7 +37,7 @@ public abstract class AbstractBindingBuilder<T> {
         this.binder = binder;
         this.elements = elements;
         this.position = elements.size();
-        this.binding = new UntargettedBindingImpl<T>(source, key, Scoping.UNSCOPED);
+        this.binding = new UntargettedBindingImpl<>(source, key, Scoping.UNSCOPED);
         elements.add(position, this.binding);
     }
 
@@ -57,8 +57,7 @@ public abstract class AbstractBindingBuilder<T> {
     protected BindingImpl<T> annotatedWithInternal(Class<? extends Annotation> annotationType) {
         checkNotNull(annotationType, "annotationType");
         checkNotAnnotated();
-        return setBinding(binding.withKey(
-                Key.get(this.binding.getKey().getTypeLiteral(), annotationType)));
+        return setBinding(binding.withKey(Key.get(this.binding.getKey().getTypeLiteral(), annotationType)));
     }
 
     /**
@@ -67,8 +66,7 @@ public abstract class AbstractBindingBuilder<T> {
     protected BindingImpl<T> annotatedWithInternal(Annotation annotation) {
         checkNotNull(annotation, "annotation");
         checkNotAnnotated();
-        return setBinding(binding.withKey(
-                Key.get(this.binding.getKey().getTypeLiteral(), annotation)));
+        return setBinding(binding.withKey(Key.get(this.binding.getKey().getTypeLiteral(), annotation)));
     }
 
     public void in(final Class<? extends Annotation> scopeAnnotation) {

src/main/java/com/google/inject/internal/AbstractBindingProcessor.java

@@ -14,17 +14,16 @@ import com.google.inject.Stage;
 import com.google.inject.TypeLiteral;
 import com.google.inject.spi.DefaultBindingTargetVisitor;
 
-import java.util.Set;
-
 /**
  * Guarantees that processing of Binding elements happens in a sane way.
  */
 abstract class AbstractBindingProcessor extends AbstractProcessor {
 
-    // It's unfortunate that we have to maintain a blacklist of specific
+    // It's unfortunate that we have to maintain a list of specific
     // classes, but we can't easily block the whole package because of
     // all our unit tests.
-    private static final Set<Class<?>> FORBIDDEN_TYPES = ImmutableSet.<Class<?>>of(
+    private static final ImmutableSet<Class<?>> FORBIDDEN_TYPES =
+            ImmutableSet.<Class<?>>of(
                     AbstractModule.class,
                     Binder.class,
                     Binding.class,
@@ -37,11 +36,11 @@ abstract class AbstractBindingProcessor extends AbstractProcessor {
                     Stage.class,
                     TypeLiteral.class);
 
-    protected final ProcessedBindingData bindingData;
+    protected final ProcessedBindingData processedBindingData;
 
-    AbstractBindingProcessor(Errors errors, ProcessedBindingData bindingData) {
+    AbstractBindingProcessor(Errors errors, ProcessedBindingData processedBindingData) {
         super(errors);
-        this.bindingData = bindingData;
+        this.processedBindingData = processedBindingData;
     }
 
     protected <T> UntargettedBindingImpl<T> invalidBinding(
@@ -61,10 +60,10 @@ abstract class AbstractBindingProcessor extends AbstractProcessor {
         BindingImpl<?> original = injector.getExistingBinding(key);
         if (original != null) {
             // If it failed because of an explicit duplicate binding...
-            if (injector.state.getExplicitBinding(key) != null) {
+            if (injector.getBindingData().getExplicitBinding(key) != null) {
                 try {
-                    if (!isOkayDuplicate(original, binding, injector.state)) {
-                        errors.bindingAlreadySet(key, original.getSource());
+                    if (!isOkayDuplicate(original, binding, injector.getBindingData())) {
+                        errors.bindingAlreadySet(binding, original);
                         return;
                     }
                 } catch (Throwable t) {
@@ -80,27 +79,34 @@ abstract class AbstractBindingProcessor extends AbstractProcessor {
         }
 
         // prevent the parent from creating a JIT binding for this key
-        injector.state.parent().blacklist(key, injector.state, binding.getSource());
-        injector.state.putBinding(key, binding);
+        injector
+                .getJitBindingData()
+                .banKeyInParent(key, injector.getBindingData(), binding.getSource());
+        injector.getBindingData().putBinding(key, binding);
     }
 
     /**
-     * We tolerate duplicate bindings if one exposes the other or if the two bindings
-     * are considered duplicates.
+     * We tolerate duplicate bindings if one exposes the other or if the two bindings are considered
+     * duplicates (see {@link Bindings#areDuplicates(BindingImpl, BindingImpl)}.
      *
      * @param original the binding in the parent injector (candidate for an exposing binding)
      * @param binding the binding to check (candidate for the exposed binding)
      */
-    private boolean isOkayDuplicate(BindingImpl<?> original, BindingImpl<?> binding, State state) {
+    private static boolean isOkayDuplicate(
+            BindingImpl<?> original, BindingImpl<?> binding, InjectorBindingData bindingData) {
         if (original instanceof ExposedBindingImpl) {
-            ExposedBindingImpl exposed = (ExposedBindingImpl) original;
+            ExposedBindingImpl<?> exposed = (ExposedBindingImpl<?>) original;
             InjectorImpl exposedFrom = (InjectorImpl) exposed.getPrivateElements().getInjector();
             return (exposedFrom == binding.getInjector());
         } else {
-            original = (BindingImpl<?>) state.getExplicitBindingsThisLevel().get(binding.getKey());
+            original = (BindingImpl<?>) bindingData.getExplicitBindingsThisLevel().get(binding.getKey());
             // If no original at this level, the original was on a parent, and we don't
             // allow deduplication between parents & children.
-            return original != null && original.equals(binding);
+            if (original == null) {
+                return false;
+            } else {
+                return original.equals(binding);
+            }
         }
     }
 
@@ -110,8 +116,8 @@ abstract class AbstractBindingProcessor extends AbstractProcessor {
     }
 
     /**
-     * Processor for visiting bindings.  Each overriden method that wants to
-     * actually process the binding should call prepareBinding first.
+     * Processor for visiting bindings. Each overriden method that wants to actually process the
+     * binding should call prepareBinding first.
      */
     abstract class Processor<T, V> extends DefaultBindingTargetVisitor<T, V> {
         final Object source;
@@ -131,16 +137,28 @@ abstract class AbstractBindingProcessor extends AbstractProcessor {
             scoping = Scoping.makeInjectable(scoping, injector, errors);
         }
 
-        protected void scheduleInitialization(final BindingImpl<?> binding) {
-            bindingData.addUninitializedBinding(new Runnable() {
-                public void run() {
+        /**
+         * Schedule initialization of this binding to occur immediately after all bindings have been
+         * initialially processed.
+         */
+        protected void scheduleInitialization(BindingImpl<?> binding) {
+            processedBindingData.addUninitializedBinding(() -> initializeBinding(binding));
+        }
+
+        /**
+         * Schedule initialization for this binding to occur after all other static initialization of
+         * bindings.
+         */
+        protected void scheduleDelayedInitialization(BindingImpl<?> binding) {
+            processedBindingData.addDelayedUninitializedBinding(() -> initializeBinding(binding));
+        }
+
+        private void initializeBinding(BindingImpl<?> binding) {
             try {
                 binding.getInjector().initializeBinding(binding, errors.withSource(source));
             } catch (ErrorsException e) {
                 errors.merge(e.getErrors());
             }
         }
-            });
-        }
     }
 }

src/main/java/com/google/inject/internal/Annotations.java

@@ -1,6 +1,7 @@
 package com.google.inject.internal;
 
-import com.google.common.base.Function;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
 import com.google.common.base.Joiner;
 import com.google.common.base.Joiner.MapJoiner;
 import com.google.common.base.Preconditions;
@@ -16,8 +17,6 @@ import com.google.inject.TypeLiteral;
 import com.google.inject.internal.util.Classes;
 import com.google.inject.name.Named;
 import com.google.inject.name.Names;
-
-import javax.inject.Qualifier;
 import java.lang.annotation.Annotation;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -28,37 +27,16 @@ import java.lang.reflect.Proxy;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Map;
+import javax.inject.Qualifier;
 
 /**
  * Annotation utilities.
  *
+ * @author crazybob@google.com (Bob Lee)
  */
 public class Annotations {
 
-    private static final MapJoiner JOINER = Joiner.on(", ").withKeyValueSeparator("=");
-    private static final Function<Object, String> DEEP_TO_STRING_FN = new Function<Object, String>() {
-        @Override
-        public String apply(Object arg) {
-            String s = Arrays.deepToString(new Object[]{arg});
-            return s.substring(1, s.length() - 1); // cut off brackets
-        }
-    };
-    private static final LoadingCache<Class<? extends Annotation>, Annotation> cache =
-            CacheBuilder.newBuilder().weakKeys().build(
-                    new CacheLoader<Class<? extends Annotation>, Annotation>() {
-                        @Override
-                        public Annotation load(Class<? extends Annotation> input) {
-                            return generateAnnotationImpl(input);
-                        }
-                    });
-    private static final AnnotationChecker scopeChecker = new AnnotationChecker(
-            Arrays.asList(ScopeAnnotation.class, javax.inject.Scope.class));
-    private static final AnnotationChecker bindingAnnotationChecker = new AnnotationChecker(
-            Arrays.asList(BindingAnnotation.class, Qualifier.class));
-
-    /**
-     * Returns {@code true} if the given annotation type has no attributes.
-     */
+    /** Returns {@code true} if the given annotation type has no attributes. */
     public static boolean isMarker(Class<? extends Annotation> annotationType) {
         return annotationType.getDeclaredMethods().length == 0;
     }
@@ -74,11 +52,22 @@ public class Annotations {
         return hasMethods;
     }
 
+    private static final LoadingCache<Class<? extends Annotation>, Annotation> cache =
+            CacheBuilder.newBuilder()
+                    .weakKeys()
+                    .build(
+                            new CacheLoader<Class<? extends Annotation>, Annotation>() {
+                                @Override
+                                public Annotation load(Class<? extends Annotation> input) {
+                                    return generateAnnotationImpl(input);
+                                }
+                            });
+
     /**
      * Generates an Annotation for the annotation class. Requires that the annotation is all
      * optionals.
      */
-    @SuppressWarnings("unchecked")
+    @SuppressWarnings("unchecked") // Safe because generateAnnotationImpl returns T for Class<T>
     public static <T extends Annotation> T generateAnnotation(Class<T> annotationType) {
         Preconditions.checkState(
                 isAllDefaultMethods(annotationType), "%s is not all default methods", annotationType);
@@ -87,9 +76,10 @@ public class Annotations {
 
     private static <T extends Annotation> T generateAnnotationImpl(final Class<T> annotationType) {
         final Map<String, Object> members = resolveMembers(annotationType);
-        return annotationType.cast(Proxy.newProxyInstance(
+        return annotationType.cast(
+                Proxy.newProxyInstance(
                         annotationType.getClassLoader(),
-                new Class<?>[]{annotationType},
+                        new Class<?>[] {annotationType},
                         new InvocationHandler() {
                             @Override
                             public Object invoke(Object proxy, Method method, Object[] args) throws Exception {
@@ -118,68 +108,67 @@ public class Annotations {
         return result.build();
     }
 
-    /**
-     * Implements {@link Annotation#equals}.
-     */
-    private static boolean annotationEquals(Class<? extends Annotation> type,
-                                            Map<String, Object> members, Object other) throws Exception {
+    /** Implements {@link Annotation#equals}. */
+    private static boolean annotationEquals(
+            Class<? extends Annotation> type, Map<String, Object> members, Object other)
+            throws Exception {
         if (!type.isInstance(other)) {
             return false;
         }
         for (Method method : type.getDeclaredMethods()) {
             String name = method.getName();
             if (!Arrays.deepEquals(
-                    new Object[]{method.invoke(other)}, new Object[]{members.get(name)})) {
+                    new Object[] {method.invoke(other)}, new Object[] {members.get(name)})) {
                 return false;
             }
         }
         return true;
     }
 
-    /**
-     * Implements {@link Annotation#hashCode}.
-     */
-    private static int annotationHashCode(Class<? extends Annotation> type,
-                                          Map<String, Object> members) throws Exception {
+    /** Implements {@link Annotation#hashCode}. */
+    private static int annotationHashCode(
+            Class<? extends Annotation> type, Map<String, Object> members) throws Exception {
         int result = 0;
         for (Method method : type.getDeclaredMethods()) {
             String name = method.getName();
             Object value = members.get(name);
-            result += (127 * name.hashCode()) ^ (Arrays.deepHashCode(new Object[]{value}) - 31);
+            result += (127 * name.hashCode()) ^ (Arrays.deepHashCode(new Object[] {value}) - 31);
         }
         return result;
     }
 
-    /**
-     * Implements {@link Annotation#toString}.
-     */
-    private static String annotationToString(Class<? extends Annotation> type,
-                                             Map<String, Object> members) throws Exception {
+    private static final MapJoiner JOINER = Joiner.on(", ").withKeyValueSeparator("=");
+
+    /** Implements {@link Annotation#toString}. */
+    private static String annotationToString(
+            Class<? extends Annotation> type, Map<String, Object> members) throws Exception {
         StringBuilder sb = new StringBuilder().append("@").append(type.getName()).append("(");
-        JOINER.appendTo(sb, Maps.transformValues(members, DEEP_TO_STRING_FN));
+        JOINER.appendTo(
+                sb,
+                Maps.transformValues(
+                        members,
+                        arg -> {
+                            String s = Arrays.deepToString(new Object[] {arg});
+                            return s.substring(1, s.length() - 1); // cut off brackets
+                        }));
         return sb.append(")").toString();
     }
 
-    /**
-     * Returns true if the given annotation is retained at runtime.
-     */
+    /** Returns true if the given annotation is retained at runtime. */
     public static boolean isRetainedAtRuntime(Class<? extends Annotation> annotationType) {
         Retention retention = annotationType.getAnnotation(Retention.class);
         return retention != null && retention.value() == RetentionPolicy.RUNTIME;
     }
 
-    /**
-     * Returns the scope annotation on {@code type}, or null if none is specified.
-     */
+    /** Returns the scope annotation on {@code type}, or null if none is specified. */
     public static Class<? extends Annotation> findScopeAnnotation(
             Errors errors, Class<?> implementation) {
         return findScopeAnnotation(errors, implementation.getAnnotations());
     }
 
-    /**
-     * Returns the scoping annotation, or null if there isn't one.
-     */
-    public static Class<? extends Annotation> findScopeAnnotation(Errors errors, Annotation[] annotations) {
+    /** Returns the scoping annotation, or null if there isn't one. */
+    public static Class<? extends Annotation> findScopeAnnotation(
+            Errors errors, Annotation[] annotations) {
         Class<? extends Annotation> found = null;
 
         for (Annotation annotation : annotations) {
@@ -207,13 +196,115 @@ public class Annotations {
         return false;
     }
 
+    private static class AnnotationToStringConfig {
+        final boolean quote;
+        final boolean includeMemberName;
+
+        AnnotationToStringConfig(boolean quote, boolean includeMemberName) {
+            this.quote = quote;
+            this.includeMemberName = includeMemberName;
+        }
+    }
+
+    private static final AnnotationToStringConfig ANNOTATION_TO_STRING_CONFIG =
+            determineAnnotationToStringConfig();
+
+    /**
+     * Returns {@code value}, quoted if annotation implementations quote their member values. In Java
+     * 9, annotations quote their string members.
+     */
+    public static String memberValueString(String value) {
+        return ANNOTATION_TO_STRING_CONFIG.quote ? "\"" + value + "\"" : value;
+    }
+
+    /**
+     * Returns string representation of the annotation memeber.
+     *
+     * <p>The value of the member is prefixed with `memberName=` unless the runtime omits the member
+     * name. The value of the member is quoted if annotation implementations quote their member values
+     * and the value type is String.
+     *
+     * <p>In Java 9, annotations quote their string members and in Java 15, the member name is
+     * omitted.
+     */
+    public static String memberValueString(String memberName, Object value) {
+        StringBuilder sb = new StringBuilder();
+        boolean quote = ANNOTATION_TO_STRING_CONFIG.quote;
+        boolean includeMemberName = ANNOTATION_TO_STRING_CONFIG.includeMemberName;
+        if (includeMemberName) {
+            sb.append(memberName).append('=');
+        }
+        if (quote && (value instanceof String)) {
+            sb.append('"').append(value).append('"');
+        } else {
+            sb.append(value);
+        }
+        return sb.toString();
+    }
+
+    @Retention(RUNTIME)
+    private @interface TestAnnotation {
+        String value();
+    }
+
+    @TestAnnotation("determineAnnotationToStringConfig")
+    private static AnnotationToStringConfig determineAnnotationToStringConfig() {
+        try {
+            String annotation =
+                    Annotations.class
+                            .getDeclaredMethod("determineAnnotationToStringConfig")
+                            .getAnnotation(TestAnnotation.class)
+                            .toString();
+            boolean quote = annotation.contains("\"determineAnnotationToStringConfig\"");
+            boolean includeMemberName = annotation.contains("value=");
+            return new AnnotationToStringConfig(quote, includeMemberName);
+        } catch (NoSuchMethodException e) {
+            throw new AssertionError(e);
+        }
+    }
+
+    /** Checks for the presence of annotations. Caches results because Android doesn't. */
+    static class AnnotationChecker {
+        private final Collection<Class<? extends Annotation>> annotationTypes;
+
+        /** Returns true if the given class has one of the desired annotations. */
+        private CacheLoader<Class<? extends Annotation>, Boolean> hasAnnotations =
+                new CacheLoader<Class<? extends Annotation>, Boolean>() {
+                    @Override
+                    public Boolean load(Class<? extends Annotation> annotationType) {
+                        for (Annotation annotation : annotationType.getAnnotations()) {
+                            if (annotationTypes.contains(annotation.annotationType())) {
+                                return true;
+                            }
+                        }
+                        return false;
+                    }
+                };
+
+        final LoadingCache<Class<? extends Annotation>, Boolean> cache =
+                CacheBuilder.newBuilder().weakKeys().build(hasAnnotations);
+
+        /** Constructs a new checker that looks for annotations of the given types. */
+        AnnotationChecker(Collection<Class<? extends Annotation>> annotationTypes) {
+            this.annotationTypes = annotationTypes;
+        }
+
+        /** Returns true if the given type has one of the desired annotations. */
+        boolean hasAnnotations(Class<? extends Annotation> annotated) {
+            return cache.getUnchecked(annotated);
+        }
+    }
+
+    private static final AnnotationChecker scopeChecker =
+            new AnnotationChecker(Arrays.asList(ScopeAnnotation.class, javax.inject.Scope.class));
+
     public static boolean isScopeAnnotation(Class<? extends Annotation> annotationType) {
         return scopeChecker.hasAnnotations(annotationType);
     }
 
     /**
-     * Adds an error if there is a misplaced annotations on {@code type}. Scoping
-     * annotations are not allowed on abstract classes or interfaces.
+     * Adds an error if there is a misplaced annotations on {@code type}. Scoping annotations are not
+     * allowed on abstract classes or interfaces.
      */
     public static void checkForMisplacedScopeAnnotations(
             Class<?> type, Object source, Errors errors) {
@@ -229,20 +320,20 @@ public class Annotations {
         }
     }
 
-    /**
-     * Gets a key for the given type, member and annotations.
-     */
-    public static Key<?> getKey(TypeLiteral<?> type, Member member, Annotation[] annotations,
-                                Errors errors) throws ErrorsException {
+    // NOTE: getKey/findBindingAnnotation are used by Gin which is abandoned.  So changing this API
+    // will prevent Gin users from upgrading Guice version.
+
+    /** Gets a key for the given type, member and annotations. */
+    public static Key<?> getKey(
+            TypeLiteral<?> type, Member member, Annotation[] annotations, Errors errors)
+            throws ErrorsException {
         int numErrorsBefore = errors.size();
         Annotation found = findBindingAnnotation(errors, member, annotations);
         errors.throwIfNewErrors(numErrorsBefore);
         return found == null ? Key.get(type) : Key.get(type, found);
     }
 
-    /**
-     * Returns the binding annotation on {@code member}, or null if there isn't one.
-     */
+    /** Returns the binding annotation on {@code member}, or null if there isn't one. */
     public static Annotation findBindingAnnotation(
             Errors errors, Member member, Annotation[] annotations) {
         Annotation found = null;
@@ -261,9 +352,10 @@ public class Annotations {
         return found;
     }
 
-    /**
-     * Returns true if annotations of the specified type are binding annotations.
-     */
+    private static final AnnotationChecker bindingAnnotationChecker =
+            new AnnotationChecker(Arrays.asList(BindingAnnotation.class, Qualifier.class));
+
+    /** Returns true if annotations of the specified type are binding annotations. */
     public static boolean isBindingAnnotation(Class<? extends Annotation> annotationType) {
         return bindingAnnotationChecker.hasAnnotations(annotationType);
     }
@@ -294,41 +386,20 @@ public class Annotations {
     }
 
     /**
-     * Checks for the presence of annotations. Caches results because Android doesn't.
+     * Returns the name the binding should use. This is based on the annotation. If the annotation has
+     * an instance and is not a marker annotation, we ask the annotation for its toString. If it was a
+     * marker annotation or just an annotation type, we use the annotation's name. Otherwise, the name
+     * is the empty string.
      */
-    static class AnnotationChecker {
-        private final Collection<Class<? extends Annotation>> annotationTypes;
-
-        /**
-         * Returns true if the given class has one of the desired annotations.
-         */
-        private CacheLoader<Class<? extends Annotation>, Boolean> hasAnnotations =
-                new CacheLoader<Class<? extends Annotation>, Boolean>() {
-                    public Boolean load(Class<? extends Annotation> annotationType) {
-                        for (Annotation annotation : annotationType.getAnnotations()) {
-                            if (annotationTypes.contains(annotation.annotationType())) {
-                                return true;
-                            }
-                        }
-                        return false;
-                    }
-                };
-
-        final LoadingCache<Class<? extends Annotation>, Boolean> cache = CacheBuilder.newBuilder().weakKeys()
-                .build(hasAnnotations);
-
-        /**
-         * Constructs a new checker that looks for annotations of the given types.
-         */
-        AnnotationChecker(Collection<Class<? extends Annotation>> annotationTypes) {
-            this.annotationTypes = annotationTypes;
-        }
-
-        /**
-         * Returns true if the given type has one of the desired annotations.
-         */
-        boolean hasAnnotations(Class<? extends Annotation> annotated) {
-            return cache.getUnchecked(annotated);
+    public static String nameOf(Key<?> key) {
+        Annotation annotation = key.getAnnotation();
+        Class<? extends Annotation> annotationType = key.getAnnotationType();
+        if (annotation != null && !isMarker(annotationType)) {
+            return key.getAnnotation().toString();
+        } else if (key.getAnnotationType() != null) {
+            return "@" + key.getAnnotationType().getName();
+        } else {
+            return "";
         }
     }
 }

src/main/java/com/google/inject/internal/BindingAlreadySetError.java

@@ -0,0 +1,52 @@
+package com.google.inject.internal;
+
+import com.google.common.collect.ImmutableList;
+import com.google.inject.Binding;
+import com.google.inject.spi.ErrorDetail;
+import java.util.ArrayList;
+import java.util.Formatter;
+import java.util.List;
+import java.util.stream.Collectors;
+
+/** Error reported by Guice when a key is bound at multiple places the injector. */
+final class BindingAlreadySetError extends InternalErrorDetail<BindingAlreadySetError> {
+    private final Binding<?> binding;
+    private final Binding<?> original;
+
+    BindingAlreadySetError(Binding<?> binding, Binding<?> original, List<Object> sources) {
+        super(
+                ErrorId.BINDING_ALREADY_SET,
+                String.format("%s was bound multiple times.", Messages.convert(binding.getKey())),
+                sources,
+                null);
+        this.binding = binding;
+        this.original = original;
+    }
+
+    @Override
+    public boolean isMergeable(ErrorDetail<?> otherError) {
+        return otherError instanceof BindingAlreadySetError
+                && ((BindingAlreadySetError) otherError).binding.getKey().equals(binding.getKey());
+    }
+
+    @Override
+    public void formatDetail(List<ErrorDetail<?>> mergeableErrors, Formatter formatter) {
+        List<List<Object>> sourcesList = new ArrayList<>();
+        sourcesList.add(ImmutableList.of(original.getSource()));
+        sourcesList.add(ImmutableList.of(binding.getSource()));
+        sourcesList.addAll(
+                mergeableErrors.stream()
+                        .map(e -> ((BindingAlreadySetError) e).binding.getSource())
+                        .map(ImmutableList::of)
+                        .collect(Collectors.toList()));
+        formatter.format("%n%s%n", Messages.bold("Bound at:"));
+        for (int i = 0; i < sourcesList.size(); i++) {
+            ErrorFormatter.formatSources(i + 1, sourcesList.get(i), formatter);
+        }
+    }
+
+    @Override
+    public BindingAlreadySetError withSources(List<Object> newSources) {
+        return new BindingAlreadySetError(binding, original, newSources);
+    }
+}

src/main/java/com/google/inject/internal/BindingBuilder.java

@@ -29,24 +29,29 @@ public class BindingBuilder<T> extends AbstractBindingBuilder<T>
         super(binder, elements, source, key);
     }
 
+    @Override
     public BindingBuilder<T> annotatedWith(Class<? extends Annotation> annotationType) {
         annotatedWithInternal(annotationType);
         return this;
     }
 
+    @Override
     public BindingBuilder<T> annotatedWith(Annotation annotation) {
         annotatedWithInternal(annotation);
         return this;
     }
 
+    @Override
     public BindingBuilder<T> to(Class<? extends T> implementation) {
         return to(Key.get(implementation));
     }
 
+    @Override
     public BindingBuilder<T> to(TypeLiteral<? extends T> implementation) {
         return to(Key.get(implementation));
     }
 
+    @Override
     public BindingBuilder<T> to(Key<? extends T> linkedKey) {
         checkNotNull(linkedKey, "linkedKey");
         checkNotTargetted();
@@ -56,6 +61,7 @@ public class BindingBuilder<T> extends AbstractBindingBuilder<T>
         return this;
     }
 
+    @Override
     public void toInstance(T instance) {
         checkNotTargetted();
 
@@ -79,10 +85,12 @@ public class BindingBuilder<T> extends AbstractBindingBuilder<T>
     }
 
     @SuppressWarnings("unchecked")
+    @Override
     public BindingBuilder<T> toProvider(Provider<? extends T> provider) {
         return toProvider((javax.inject.Provider<T>) provider);
     }
 
+    @Override
     public BindingBuilder<T> toProvider(javax.inject.Provider<? extends T> provider) {
         checkNotNull(provider, "provider");
         checkNotTargetted();
@@ -102,16 +110,19 @@ public class BindingBuilder<T> extends AbstractBindingBuilder<T>
         return this;
     }
 
+    @Override
     public BindingBuilder<T> toProvider(
             Class<? extends javax.inject.Provider<? extends T>> providerType) {
         return toProvider(Key.get(providerType));
     }
 
+    @Override
     public BindingBuilder<T> toProvider(
             TypeLiteral<? extends javax.inject.Provider<? extends T>> providerType) {
         return toProvider(Key.get(providerType));
     }
 
+    @Override
     public BindingBuilder<T> toProvider(
             Key<? extends javax.inject.Provider<? extends T>> providerKey) {
         checkNotNull(providerKey, "providerKey");
@@ -123,10 +134,12 @@ public class BindingBuilder<T> extends AbstractBindingBuilder<T>
         return this;
     }
 
+    @Override
     public <S extends T> ScopedBindingBuilder toConstructor(Constructor<S> constructor) {
         return toConstructor(constructor, TypeLiteral.get(constructor.getDeclaringClass()));
     }
 
+    @Override
     public <S extends T> ScopedBindingBuilder toConstructor(Constructor<S> constructor,
                                                             TypeLiteral<? extends S> type) {
         checkNotNull(constructor, "constructor");

src/main/java/com/google/inject/internal/BindingImpl.java

@@ -34,14 +34,17 @@ public abstract class BindingImpl<T> implements Binding<T> {
         this.scoping = scoping;
     }
 
+    @Override
     public Key<T> getKey() {
         return key;
     }
 
+    @Override
     public Object getSource() {
         return source;
     }
 
+    @Override
     public Provider<T> getProvider() {
         if (provider == null) {
             if (injector == null) {
@@ -69,10 +72,12 @@ public abstract class BindingImpl<T> implements Binding<T> {
         return this instanceof InstanceBinding;
     }
 
+    @Override
     public <V> V acceptVisitor(ElementVisitor<V> visitor) {
         return visitor.visit(this);
     }
 
+    @Override
     public <V> V acceptScopingVisitor(BindingScopingVisitor<V> visitor) {
         return scoping.acceptVisitor(visitor);
     }

src/main/java/com/google/inject/internal/BindingProcessor.java

@@ -15,7 +15,6 @@ import com.google.inject.spi.ProviderBinding;
 import com.google.inject.spi.ProviderInstanceBinding;
 import com.google.inject.spi.ProviderKeyBinding;
 import com.google.inject.spi.UntargettedBinding;
-
 import java.util.Set;
 
 /**
@@ -25,8 +24,9 @@ final class BindingProcessor extends AbstractBindingProcessor {
 
     private final Initializer initializer;
 
-    BindingProcessor(Errors errors, Initializer initializer, ProcessedBindingData bindingData) {
-        super(errors, bindingData);
+    BindingProcessor(
+            Errors errors, Initializer initializer, ProcessedBindingData processedBindingData) {
+        super(errors, processedBindingData);
         this.initializer = initializer;
     }
 
@@ -49,13 +49,22 @@ final class BindingProcessor extends AbstractBindingProcessor {
             return true;
         }
 
-        return command.acceptTargetVisitor(new Processor<T, Boolean>((BindingImpl<T>) command) {
+        return command.acceptTargetVisitor(
+                new Processor<T, Boolean>((BindingImpl<T>) command) {
                     @Override
                     public Boolean visit(ConstructorBinding<? extends T> binding) {
                         prepareBinding();
                         try {
-                    ConstructorBindingImpl<T> onInjector = ConstructorBindingImpl.create(injector, key,
-                            binding.getConstructor(), source, scoping, errors, false, false);
+                            ConstructorBindingImpl<T> onInjector =
+                                    ConstructorBindingImpl.create(
+                                            injector,
+                                            key,
+                                            binding.getConstructor(),
+                                            source,
+                                            scoping,
+                                            errors,
+                                            false,
+                                            false);
                             scheduleInitialization(onInjector);
                             putBinding(onInjector);
                         } catch (ErrorsException e) {
@@ -72,13 +81,15 @@ final class BindingProcessor extends AbstractBindingProcessor {
                         T instance = binding.getInstance();
                         @SuppressWarnings("unchecked") // safe to cast to binding<T> because
                         // the processor was constructed w/ it
-                        Initializable<T> ref = initializer.requestInjection(
+                        Initializable<T> ref =
+                                initializer.requestInjection(
                                         injector, instance, (Binding<T>) binding, source, injectionPoints);
-                ConstantFactory<? extends T> factory = new ConstantFactory<T>(ref);
-                InternalFactory<? extends T> scopedFactory
-                        = Scoping.scope(key, injector, factory, source, scoping);
-                putBinding(new InstanceBindingImpl<T>(injector, key, source, scopedFactory, injectionPoints,
-                        instance));
+                        ConstantFactory<? extends T> factory = new ConstantFactory<>(ref);
+                        InternalFactory<? extends T> scopedFactory =
+                                Scoping.scope(key, injector, factory, source, scoping);
+                        putBinding(
+                                new InstanceBindingImpl<T>(
+                                        injector, key, source, scopedFactory, injectionPoints, instance));
                         return true;
                     }
 
@@ -86,35 +97,54 @@ final class BindingProcessor extends AbstractBindingProcessor {
                     public Boolean visit(ProviderInstanceBinding<? extends T> binding) {
                         prepareBinding();
                         javax.inject.Provider<? extends T> provider = binding.getUserSuppliedProvider();
+                        if (provider instanceof InternalProviderInstanceBindingImpl.Factory) {
+                            @SuppressWarnings("unchecked")
+                            InternalProviderInstanceBindingImpl.Factory<T> asProviderMethod =
+                                    (InternalProviderInstanceBindingImpl.Factory<T>) provider;
+                            return visitInternalProviderInstanceBindingFactory(asProviderMethod);
+                        }
                         Set<InjectionPoint> injectionPoints = binding.getInjectionPoints();
                         Initializable<? extends javax.inject.Provider<? extends T>> initializable =
                                 initializer.<javax.inject.Provider<? extends T>>requestInjection(
                                         injector, provider, null, source, injectionPoints);
                         // always visited with Binding<T>
                         @SuppressWarnings("unchecked")
-                InternalFactory<T> factory = new InternalFactoryToInitializableAdapter<T>(
-                        initializable, source,
+                        InternalFactory<T> factory =
+                                new InternalFactoryToInitializableAdapter<T>(
+                                        initializable,
+                                        source,
                                         injector.provisionListenerStore.get((ProviderInstanceBinding<T>) binding));
-                InternalFactory<? extends T> scopedFactory
-                        = Scoping.scope(key, injector, factory, source, scoping);
-                putBinding(new ProviderInstanceBindingImpl<T>(injector, key, source, scopedFactory, scoping,
-                        provider, injectionPoints));
+                        InternalFactory<? extends T> scopedFactory =
+                                Scoping.scope(key, injector, factory, source, scoping);
+                        putBinding(
+                                new ProviderInstanceBindingImpl<T>(
+                                        injector, key, source, scopedFactory, scoping, provider, injectionPoints));
                         return true;
                     }
 
                     @Override
                     public Boolean visit(ProviderKeyBinding<? extends T> binding) {
                         prepareBinding();
-                Key<? extends javax.inject.Provider<? extends T>> providerKey = binding.getProviderKey();
+                        Key<? extends javax.inject.Provider<? extends T>> providerKey =
+                                binding.getProviderKey();
                         // always visited with Binding<T>
                         @SuppressWarnings("unchecked")
-                BoundProviderFactory<T> boundProviderFactory = new BoundProviderFactory<T>(
-                        injector, providerKey, source,
+                        BoundProviderFactory<T> boundProviderFactory =
+                                new BoundProviderFactory<T>(
+                                        injector,
+                                        providerKey,
+                                        source,
                                         injector.provisionListenerStore.get((ProviderKeyBinding<T>) binding));
-                bindingData.addCreationListener(boundProviderFactory);
-                InternalFactory<? extends T> scopedFactory = Scoping.scope(
-                        key, injector, (InternalFactory<? extends T>) boundProviderFactory, source, scoping);
-                putBinding(new LinkedProviderBindingImpl<T>(
+                        processedBindingData.addCreationListener(boundProviderFactory);
+                        InternalFactory<? extends T> scopedFactory =
+                                Scoping.scope(
+                                        key,
+                                        injector,
+                                        (InternalFactory<? extends T>) boundProviderFactory,
+                                        source,
+                                        scoping);
+                        putBinding(
+                                new LinkedProviderBindingImpl<T>(
                                         injector, key, source, scopedFactory, scoping, providerKey));
                         return true;
                     }
@@ -124,18 +154,44 @@ final class BindingProcessor extends AbstractBindingProcessor {
                         prepareBinding();
                         Key<? extends T> linkedKey = binding.getLinkedKey();
                         if (key.equals(linkedKey)) {
-                    errors.recursiveBinding();
+                            // TODO: b/168656899 check for transitive recursive binding
+                            errors.recursiveBinding(key, linkedKey);
                         }
 
-                FactoryProxy<T> factory = new FactoryProxy<T>(injector, key, linkedKey, source);
-                bindingData.addCreationListener(factory);
-                InternalFactory<? extends T> scopedFactory
-                        = Scoping.scope(key, injector, factory, source, scoping);
+                        FactoryProxy<T> factory = new FactoryProxy<>(injector, key, linkedKey, source);
+                        processedBindingData.addCreationListener(factory);
+                        InternalFactory<? extends T> scopedFactory =
+                                Scoping.scope(key, injector, factory, source, scoping);
                         putBinding(
                                 new LinkedBindingImpl<T>(injector, key, source, scopedFactory, scoping, linkedKey));
                         return true;
                     }
 
+                    /** Handle ProviderMethods specially. */
+                    private Boolean visitInternalProviderInstanceBindingFactory(
+                            InternalProviderInstanceBindingImpl.Factory<T> provider) {
+                        InternalProviderInstanceBindingImpl<T> binding =
+                                new InternalProviderInstanceBindingImpl<T>(
+                                        injector,
+                                        key,
+                                        source,
+                                        provider,
+                                        Scoping.scope(key, injector, provider, source, scoping),
+                                        scoping);
+                        switch (binding.getInitializationTiming()) {
+                            case DELAYED:
+                                scheduleDelayedInitialization(binding);
+                                break;
+                            case EAGER:
+                                scheduleInitialization(binding);
+                                break;
+                            default:
+                                throw new AssertionError();
+                        }
+                        putBinding(binding);
+                        return true;
+                    }
+
                     @Override
                     public Boolean visit(UntargettedBinding<? extends T> untargetted) {
                         return false;
@@ -172,9 +228,14 @@ final class BindingProcessor extends AbstractBindingProcessor {
     }
 
     private <T> void bindExposed(PrivateElements privateElements, Key<T> key) {
-        ExposedKeyFactory<T> exposedKeyFactory = new ExposedKeyFactory<T>(key, privateElements);
-        bindingData.addCreationListener(exposedKeyFactory);
-        putBinding(new ExposedBindingImpl<T>(
-                injector, privateElements.getExposedSource(key), key, exposedKeyFactory, privateElements));
+        ExposedKeyFactory<T> exposedKeyFactory = new ExposedKeyFactory<>(key, privateElements);
+        processedBindingData.addCreationListener(exposedKeyFactory);
+        putBinding(
+                new ExposedBindingImpl<T>(
+                        injector,
+                        privateElements.getExposedSource(key),
+                        key,
+                        exposedKeyFactory,
+                        privateElements));
     }
 }

src/main/java/com/google/inject/internal/BoundProviderFactory.java

@@ -6,16 +6,17 @@ import com.google.inject.spi.Dependency;
 
 import javax.inject.Provider;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
 /**
  * Delegates to a custom factory which is also bound in the injector.
  */
 final class BoundProviderFactory<T> extends ProviderInternalFactory<T> implements CreationListener {
 
-    final Key<? extends javax.inject.Provider<? extends T>> providerKey;
+    private final Key<? extends javax.inject.Provider<? extends T>> providerKey;
+
     private final ProvisionListenerStackCallback<T> provisionCallback;
+
     private final InjectorImpl injector;
+
     private InternalFactory<? extends javax.inject.Provider<? extends T>> providerFactory;
 
     BoundProviderFactory(
@@ -24,11 +25,12 @@ final class BoundProviderFactory<T> extends ProviderInternalFactory<T> implement
             Object source,
             ProvisionListenerStackCallback<T> provisionCallback) {
         super(source);
-        this.provisionCallback = checkNotNull(provisionCallback, "provisionCallback");
+        this.provisionCallback = provisionCallback;
         this.injector = injector;
         this.providerKey = providerKey;
     }
 
+    @Override
     public void notify(Errors errors) {
         try {
             providerFactory = injector.getInternalFactory(providerKey, errors.withSource(source), JitLimitation.NEW_OR_EXISTING_JIT);
@@ -37,25 +39,27 @@ final class BoundProviderFactory<T> extends ProviderInternalFactory<T> implement
         }
     }
 
-    public T get(Errors errors, InternalContext context, Dependency<?> dependency, boolean linked)
-            throws ErrorsException {
+    @Override
+    public T get(InternalContext context, Dependency<?> dependency, boolean linked)
+            throws InternalProvisionException {
         context.pushState(providerKey, source);
         try {
-            errors = errors.withSource(providerKey);
-            javax.inject.Provider<? extends T> provider = providerFactory.get(errors, context, dependency, true);
-            return circularGet(provider, errors, context, dependency, provisionCallback);
+            javax.inject.Provider<? extends T> provider = providerFactory.get(context, dependency, true);
+            return circularGet(provider, context, dependency, provisionCallback);
+        } catch (InternalProvisionException ipe) {
+            throw ipe.addSource(providerKey);
         } finally {
             context.popState();
         }
     }
 
     @Override
-    protected T provision(Provider<? extends T> provider, Errors errors, Dependency<?> dependency,
-                          ConstructionContext<T> constructionContext) throws ErrorsException {
+    protected T provision(Provider<? extends T> provider, Dependency<?> dependency,
+                          ConstructionContext<T> constructionContext) throws InternalProvisionException {
         try {
-            return super.provision(provider, errors, dependency, constructionContext);
+            return super.provision(provider, dependency, constructionContext);
         } catch (RuntimeException userException) {
-            throw errors.errorInProvider(userException).toException();
+            throw InternalProvisionException.errorInProvider(userException);
         }
     }
 

src/main/java/com/google/inject/internal/ChildBindingAlreadySetError.java

@@ -0,0 +1,85 @@
+package com.google.inject.internal;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Streams;
+import com.google.inject.Key;
+import com.google.inject.spi.ErrorDetail;
+import java.util.ArrayList;
+import java.util.Formatter;
+import java.util.List;
+import java.util.stream.Collectors;
+
+/**
+ * Error reported by Guice when a key is already bound in one or more child injectors or private
+ * modules.
+ */
+final class ChildBindingAlreadySetError extends InternalErrorDetail<ChildBindingAlreadySetError> {
+    private final Key<?> key;
+    private final ImmutableList<Object> existingSources;
+
+    ChildBindingAlreadySetError(Key<?> key, Iterable<Object> existingSoruces, List<Object> sources) {
+        super(
+                ErrorId.CHILD_BINDING_ALREADY_SET,
+                String.format(
+                        "Unable to create binding for %s because it was already configured on one or more"
+                                + " child injectors or private modules.",
+                        Messages.convert(key)),
+                sources,
+                null);
+        this.key = key;
+        // Can't use ImmutableList.toImmutableList here because of b/156759807.
+        this.existingSources =
+                ImmutableList.copyOf(
+                        Streams.stream(existingSoruces)
+                                .map(source -> source == null ? "" : source)
+                                .collect(Collectors.toList()));
+    }
+
+    @Override
+    public boolean isMergeable(ErrorDetail<?> otherError) {
+        return otherError instanceof ChildBindingAlreadySetError
+                && ((ChildBindingAlreadySetError) otherError).key.equals(this.key);
+    }
+
+    @Override
+    public void formatDetail(List<ErrorDetail<?>> mergeableErrors, Formatter formatter) {
+        formatter.format("%n%s%n", Messages.bold("Bound at:"));
+        int index = 1;
+        for (Object source : existingSources) {
+            formatter.format("%-2s: ", index++);
+            if (source.equals("")) {
+                formatter.format("as a just-in-time binding%n");
+            } else {
+                new SourceFormatter(source, formatter, /* omitPreposition= */ true).format();
+            }
+        }
+        List<List<Object>> sourcesList = new ArrayList<>();
+        sourcesList.add(getSources());
+        mergeableErrors.forEach(error -> sourcesList.add(error.getSources()));
+
+        List<List<Object>> filteredSources =
+                sourcesList.stream()
+                        .map(this::trimSource)
+                        .filter(list -> !list.isEmpty())
+                        .collect(Collectors.toList());
+        if (!filteredSources.isEmpty()) {
+            formatter.format("%n%s%n", Messages.bold("Requested by:"));
+            for (int i = 0; i < sourcesList.size(); i++) {
+                ErrorFormatter.formatSources(i + 1, sourcesList.get(i), formatter);
+            }
+        }
+
+        // TODO(b/151482394): Detect if the key was bound in any PrivateModule and suggest exposing the
+        // key in those cases.
+    }
+
+    @Override
+    public ChildBindingAlreadySetError withSources(List<Object> newSources) {
+        return new ChildBindingAlreadySetError(key, existingSources, newSources);
+    }
+
+    /** Omit the key itself in the source list since the information is redundant. */
+    private List<Object> trimSource(List<Object> sources) {
+        return sources.stream().filter(source -> !source.equals(this.key)).collect(Collectors.toList());
+    }
+}

src/main/java/com/google/inject/internal/ConstantBindingBuilderImpl.java

@@ -6,7 +6,6 @@ import com.google.inject.Key;
 import com.google.inject.binder.AnnotatedConstantBindingBuilder;
 import com.google.inject.binder.ConstantBindingBuilder;
 import com.google.inject.spi.Element;
-import com.google.inject.spi.InjectionPoint;
 
 import java.lang.annotation.Annotation;
 import java.util.List;
@@ -24,56 +23,69 @@ public final class ConstantBindingBuilderImpl<T>
         super(binder, elements, source, (Key<T>) NULL_KEY);
     }
 
+    @Override
     public ConstantBindingBuilder annotatedWith(Class<? extends Annotation> annotationType) {
         annotatedWithInternal(annotationType);
         return this;
     }
 
+    @Override
     public ConstantBindingBuilder annotatedWith(Annotation annotation) {
         annotatedWithInternal(annotation);
         return this;
     }
 
+    @Override
     public void to(final String value) {
         toConstant(String.class, value);
     }
 
+    @Override
     public void to(final int value) {
         toConstant(Integer.class, value);
     }
 
+    @Override
     public void to(final long value) {
         toConstant(Long.class, value);
     }
 
+    @Override
     public void to(final boolean value) {
         toConstant(Boolean.class, value);
     }
 
+    @Override
     public void to(final double value) {
         toConstant(Double.class, value);
     }
 
+    @Override
     public void to(final float value) {
         toConstant(Float.class, value);
     }
 
+    @Override
     public void to(final short value) {
         toConstant(Short.class, value);
     }
 
+    @Override
     public void to(final char value) {
         toConstant(Character.class, value);
     }
 
+    @Override
     public void to(final byte value) {
         toConstant(Byte.class, value);
     }
 
+    @Override
     public void to(final Class<?> value) {
         toConstant(Class.class, value);
     }
 
+    @Override
     public <E extends Enum<E>> void to(final E value) {
         toConstant(value.getDeclaringClass(), value);
     }
@@ -105,7 +117,7 @@ public final class ConstantBindingBuilderImpl<T>
         }
 
         setBinding(new InstanceBindingImpl<T>(
-                base.getSource(), key, base.getScoping(), ImmutableSet.<InjectionPoint>of(), instanceAsT));
+                base.getSource(), key, base.getScoping(), ImmutableSet.of(), instanceAsT));
     }
 
     @Override

src/main/java/com/google/inject/internal/ConstantFactory.java

@@ -7,15 +7,17 @@ final class ConstantFactory<T> implements InternalFactory<T> {
 
     private final Initializable<T> initializable;
 
-    public ConstantFactory(Initializable<T> initializable) {
+    ConstantFactory(Initializable<T> initializable) {
         this.initializable = initializable;
     }
 
-    public T get(Errors errors, InternalContext context, Dependency dependency, boolean linked)
-            throws ErrorsException {
-        return initializable.get(errors);
+    @Override
+    public T get(InternalContext context, Dependency<?> dependency, boolean linked)
+            throws InternalProvisionException {
+        return initializable.get();
     }
 
+    @Override
     public String toString() {
         return MoreObjects.toStringHelper(ConstantFactory.class)
                 .add("value", initializable)

src/main/java/com/google/inject/internal/ConstructionContext.java

@@ -41,26 +41,26 @@ final class ConstructionContext<T> {
         invocationHandlers = null;
     }
 
-    public Object createProxy(Errors errors, InjectorOptions injectorOptions,
-                              Class<?> expectedType) throws ErrorsException {
+    public Object createProxy(InjectorOptions injectorOptions,
+                              Class<?> expectedType) throws InternalProvisionException {
         if (injectorOptions.disableCircularProxies) {
-            throw errors.circularProxiesDisabled(expectedType).toException();
+            throw InternalProvisionException.circularDependenciesDisabled(expectedType);
         }
         if (!expectedType.isInterface()) {
-            throw errors.cannotSatisfyCircularDependency(expectedType).toException();
+            throw InternalProvisionException.cannotProxyClass(expectedType);
         }
 
         if (invocationHandlers == null) {
-            invocationHandlers = new ArrayList<DelegatingInvocationHandler<T>>();
+            invocationHandlers = new ArrayList<>();
         }
 
-        DelegatingInvocationHandler<T> invocationHandler = new DelegatingInvocationHandler<T>();
+        DelegatingInvocationHandler<T> invocationHandler = new DelegatingInvocationHandler<>();
         invocationHandlers.add(invocationHandler);
 
         ClassLoader classLoader = expectedType.getClass().getClassLoader() != null ?
                 expectedType.getClass().getClassLoader() : ClassLoader.getSystemClassLoader();
         return expectedType.cast(Proxy.newProxyInstance(classLoader,
-                new Class[]{expectedType, CircularDependencyProxy.class}, invocationHandler));
+                new Class<?>[]{expectedType, CircularDependencyProxy.class}, invocationHandler));
     }
 
     public void setProxyDelegates(T delegate) {

src/main/java/com/google/inject/internal/ConstructorBindingImpl.java

@@ -1,11 +1,15 @@
 package com.google.inject.internal;
 
+import static com.google.common.base.Preconditions.checkState;
+import static com.google.inject.internal.Annotations.findScopeAnnotation;
+import static com.google.inject.internal.GuiceInternal.GUICE_INTERNAL;
+import static com.google.inject.spi.Elements.withTrustedSource;
+
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Objects;
 import com.google.common.collect.ImmutableSet;
 import com.google.inject.Binder;
 import com.google.inject.ConfigurationException;
-import com.google.inject.Inject;
 import com.google.inject.Key;
 import com.google.inject.TypeLiteral;
 import com.google.inject.internal.util.Classes;
@@ -13,59 +17,70 @@ import com.google.inject.spi.BindingTargetVisitor;
 import com.google.inject.spi.ConstructorBinding;
 import com.google.inject.spi.Dependency;
 import com.google.inject.spi.InjectionPoint;
-
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Modifier;
 import java.util.Set;
 
-import static com.google.common.base.Preconditions.checkState;
-import static com.google.inject.internal.Annotations.findScopeAnnotation;
-
 final class ConstructorBindingImpl<T> extends BindingImpl<T>
         implements ConstructorBinding<T>, DelayedInitialize {
 
     private final Factory<T> factory;
     private final InjectionPoint constructorInjectionPoint;
 
-    private ConstructorBindingImpl(InjectorImpl injector, Key<T> key, Object source,
-                                   InternalFactory<? extends T> scopedFactory, Scoping scoping, Factory<T> factory,
+    private ConstructorBindingImpl(
+            InjectorImpl injector,
+            Key<T> key,
+            Object source,
+            InternalFactory<? extends T> scopedFactory,
+            Scoping scoping,
+            Factory<T> factory,
             InjectionPoint constructorInjectionPoint) {
         super(injector, key, source, scopedFactory, scoping);
         this.factory = factory;
         this.constructorInjectionPoint = constructorInjectionPoint;
     }
 
-    public ConstructorBindingImpl(Key<T> key, Object source, Scoping scoping,
-                                  InjectionPoint constructorInjectionPoint, Set<InjectionPoint> injectionPoints) {
+    public ConstructorBindingImpl(
+            Key<T> key,
+            Object source,
+            Scoping scoping,
+            InjectionPoint constructorInjectionPoint,
+            Set<InjectionPoint> injectionPoints) {
         super(source, key, scoping);
-        this.factory = new Factory<T>(false, key);
-        ConstructionProxy<T> constructionProxy
-                = new DefaultConstructionProxyFactory<T>(constructorInjectionPoint).create();
+        this.factory = new Factory<>(false, key);
+        ConstructionProxy<T> constructionProxy =
+                new DefaultConstructionProxyFactory<T>(constructorInjectionPoint).create();
         this.constructorInjectionPoint = constructorInjectionPoint;
-        factory.constructorInjector = new ConstructorInjector<T>(
-                injectionPoints, constructionProxy, null, null);
+        factory.constructorInjector =
+                new ConstructorInjector<T>(injectionPoints, constructionProxy, null, null);
     }
 
     /**
      * @param constructorInjector the constructor to use, or {@code null} to use the default.
-     * @param failIfNotLinked     true if this ConstructorBindingImpl's InternalFactory should
-     *                            only succeed if retrieved from a linked binding
+     * @param failIfNotLinked true if this ConstructorBindingImpl's InternalFactory should only
+     *     succeed if retrieved from a linked binding
      */
-    static <T> ConstructorBindingImpl<T> create(InjectorImpl injector, Key<T> key,
-                                                InjectionPoint constructorInjector, Object source, Scoping scoping, Errors errors,
-                                                boolean failIfNotLinked, boolean failIfNotExplicit)
+    static <T> ConstructorBindingImpl<T> create(
+            InjectorImpl injector,
+            Key<T> key,
+            InjectionPoint constructorInjector,
+            Object source,
+            Scoping scoping,
+            Errors errors,
+            boolean failIfNotLinked,
+            boolean atInjectRequired)
             throws ErrorsException {
         int numErrors = errors.size();
 
-        @SuppressWarnings("unchecked") // constructorBinding guarantees type is consistent
-                Class<? super T> rawType = constructorInjector == null
+        Class<?> rawType =
+                constructorInjector == null
                         ? key.getTypeLiteral().getRawType()
-                : (Class) constructorInjector.getDeclaringType().getRawType();
+                        : constructorInjector.getDeclaringType().getRawType();
 
         // We can't inject abstract classes.
         if (Modifier.isAbstract(rawType.getModifiers())) {
-            errors.missingImplementation(key);
+            errors.missingImplementationWithHint(key, injector);
         }
 
         // Error: Inner class.
@@ -78,10 +93,8 @@ final class ConstructorBindingImpl<T> extends BindingImpl<T>
         // Find a constructor annotated @Inject
         if (constructorInjector == null) {
             try {
-                constructorInjector = InjectionPoint.forConstructorOf(key.getTypeLiteral());
-                if (failIfNotExplicit && !hasAtInject((Constructor) constructorInjector.getMember())) {
-                    errors.atInjectRequired(rawType);
-                }
+                constructorInjector =
+                        InjectionPoint.forConstructorOf(key.getTypeLiteral(), atInjectRequired);
             } catch (ConfigurationException e) {
                 throw errors.merge(e.getErrorMessages()).toException();
             }
@@ -92,47 +105,36 @@ final class ConstructorBindingImpl<T> extends BindingImpl<T>
             Class<?> annotatedType = constructorInjector.getMember().getDeclaringClass();
             Class<? extends Annotation> scopeAnnotation = findScopeAnnotation(errors, annotatedType);
             if (scopeAnnotation != null) {
-                scoping = Scoping.makeInjectable(Scoping.forAnnotation(scopeAnnotation),
-                        injector, errors.withSource(rawType));
+                scoping =
+                        Scoping.makeInjectable(
+                                Scoping.forAnnotation(scopeAnnotation), injector, errors.withSource(rawType));
             }
         }
 
         errors.throwIfNewErrors(numErrors);
 
-        Factory<T> factoryFactory = new Factory<T>(failIfNotLinked, key);
-        InternalFactory<? extends T> scopedFactory
-                = Scoping.scope(key, injector, factoryFactory, source, scoping);
+        Factory<T> factoryFactory = new Factory<>(failIfNotLinked, key);
+        InternalFactory<? extends T> scopedFactory =
+                Scoping.scope(key, injector, factoryFactory, source, scoping);
 
         return new ConstructorBindingImpl<T>(
                 injector, key, source, scopedFactory, scoping, factoryFactory, constructorInjector);
     }
 
-    /**
-     * Returns true if the inject annotation is on the constructor.
-     */
-    private static boolean hasAtInject(Constructor cxtor) {
-        return cxtor.isAnnotationPresent(Inject.class)
-                || cxtor.isAnnotationPresent(javax.inject.Inject.class);
-    }
-
+    @Override
     @SuppressWarnings("unchecked") // the result type always agrees with the ConstructorInjector type
     public void initialize(InjectorImpl injector, Errors errors) throws ErrorsException {
         factory.constructorInjector =
                 (ConstructorInjector<T>) injector.constructors.get(constructorInjectionPoint, errors);
-        factory.provisionCallback =
-                injector.provisionListenerStore.get(this);
+        factory.provisionCallback = injector.provisionListenerStore.get(this);
     }
 
-    /**
-     * True if this binding has been initialized and is ready for use.
-     */
+    /** True if this binding has been initialized and is ready for use. */
     boolean isInitialized() {
         return factory.constructorInjector != null;
     }
 
-    /**
-     * Returns an injection point that can be used to clean up the constructor store.
-     */
+    /** Returns an injection point that can be used to clean up the constructor store. */
     InjectionPoint getInternalConstructor() {
         if (factory.constructorInjector != null) {
             return factory.constructorInjector.getConstructionProxy().getInjectionPoint();
@@ -141,44 +143,48 @@ final class ConstructorBindingImpl<T> extends BindingImpl<T>
         }
     }
 
-    /**
-     * Returns a set of dependencies that can be iterated over to clean up stray JIT bindings.
-     */
+    /** Returns a set of dependencies that can be iterated over to clean up stray JIT bindings. */
     Set<Dependency<?>> getInternalDependencies() {
         ImmutableSet.Builder<InjectionPoint> builder = ImmutableSet.builder();
         if (factory.constructorInjector == null) {
             builder.add(constructorInjectionPoint);
-            // If the below throws, it's OK -- we just ignore those dependencies, because no one
-            // could have used them anyway.
             try {
-                builder.addAll(InjectionPoint.forInstanceMethodsAndFields(constructorInjectionPoint.getDeclaringType()));
+                builder.addAll(
+                        InjectionPoint.forInstanceMethodsAndFields(
+                                constructorInjectionPoint.getDeclaringType()));
             } catch (ConfigurationException ignored) {
+                // This is OK -- we just ignore those dependencies, because no one could have used them
+                // anyway.
             }
         } else {
-            builder.add(getConstructor())
-                    .addAll(getInjectableMembers());
+            builder.add(getConstructor()).addAll(getInjectableMembers());
         }
 
         return Dependency.forInjectionPoints(builder.build());
     }
 
+    @Override
     public <V> V acceptTargetVisitor(BindingTargetVisitor<? super T, V> visitor) {
         checkState(factory.constructorInjector != null, "not initialized");
         return visitor.visit(this);
     }
 
+    @Override
     public InjectionPoint getConstructor() {
         checkState(factory.constructorInjector != null, "Binding is not ready");
         return factory.constructorInjector.getConstructionProxy().getInjectionPoint();
     }
 
+    @Override
     public Set<InjectionPoint> getInjectableMembers() {
         checkState(factory.constructorInjector != null, "Binding is not ready");
         return factory.constructorInjector.getInjectableMembers();
     }
 
+    @Override
     public Set<Dependency<?>> getDependencies() {
-        return Dependency.forInjectionPoints(new ImmutableSet.Builder<InjectionPoint>()
+        return Dependency.forInjectionPoints(
+                new ImmutableSet.Builder<InjectionPoint>()
                         .add(getConstructor())
                         .addAll(getInjectableMembers())
                         .build());
@@ -196,11 +202,17 @@ final class ConstructorBindingImpl<T> extends BindingImpl<T>
                 null, key, getSource(), factory, getScoping(), factory, constructorInjectionPoint);
     }
 
+    @Override
     @SuppressWarnings("unchecked") // the raw constructor member and declaring type always agree
     public void applyTo(Binder binder) {
         InjectionPoint constructor = getConstructor();
-        getScoping().applyTo(binder.withSource(getSource()).bind(getKey()).toConstructor(
-                (Constructor) getConstructor().getMember(), (TypeLiteral) constructor.getDeclaringType()));
+        getScoping()
+                .applyTo(
+                        withTrustedSource(GUICE_INTERNAL, binder, getSource())
+                                .bind(getKey())
+                                .toConstructor(
+                                        (Constructor) getConstructor().getMember(),
+                                        (TypeLiteral) constructor.getDeclaringType()));
     }
 
     @Override
@@ -240,19 +252,22 @@ final class ConstructorBindingImpl<T> extends BindingImpl<T>
             this.key = key;
         }
 
+        @Override
         @SuppressWarnings("unchecked")
-        public T get(Errors errors, InternalContext context, Dependency<?> dependency, boolean linked)
-                throws ErrorsException {
-            checkState(constructorInjector != null, "Constructor not ready");
+        public T get(InternalContext context, Dependency<?> dependency, boolean linked)
+                throws InternalProvisionException {
+            ConstructorInjector<T> localInjector = constructorInjector;
+            if (localInjector == null) {
+                throw new IllegalStateException("Constructor not ready");
+            }
 
-            if (failIfNotLinked && !linked) {
-                throw errors.jitDisabled(key).toException();
+            if (!linked && failIfNotLinked) {
+                throw InternalProvisionException.jitDisabled(key);
             }
 
             // This may not actually be safe because it could return a super type of T (if that's all the
             // client needs), but it should be OK in practice thanks to the wonders of erasure.
-            return (T) constructorInjector.construct(errors, context,
-                    dependency.getKey().getTypeLiteral().getRawType(), provisionCallback);
+            return (T) localInjector.construct(context, dependency, provisionCallback);
         }
     }
 }

src/main/java/com/google/inject/internal/ConstructorInjector.java

@@ -2,6 +2,7 @@ package com.google.inject.internal;
 
 import com.google.common.collect.ImmutableSet;
 import com.google.inject.internal.ProvisionListenerStackCallback.ProvisionCallback;
+import com.google.inject.spi.Dependency;
 import com.google.inject.spi.InjectionPoint;
 
 import java.lang.reflect.InvocationTargetException;
@@ -40,37 +41,39 @@ final class ConstructorInjector<T> {
      * Construct an instance. Returns {@code Object} instead of {@code T} because
      * it may return a proxy.
      */
-    Object construct(final Errors errors, final InternalContext context,
-                     Class<?> expectedType,
+    Object construct(final InternalContext context,
+                     Dependency<?> dependency,
                      ProvisionListenerStackCallback<T> provisionCallback)
-            throws ErrorsException {
+            throws InternalProvisionException {
         final ConstructionContext<T> constructionContext = context.getConstructionContext(this);
 
         // We have a circular reference between constructors. Return a proxy.
         if (constructionContext.isConstructing()) {
             // TODO (crazybob): if we can't proxy this object, can we proxy the other object?
             return constructionContext.createProxy(
-                    errors, context.getInjectorOptions(), expectedType);
+                    context.getInjectorOptions(), dependency.getKey().getTypeLiteral().getRawType());
         }
 
         // If we're re-entering this factory while injecting fields or methods,
         // return the same instance. This prevents infinite loops.
         T t = constructionContext.getCurrentReference();
         if (t != null) {
+            if (context.getInjectorOptions().disableCircularProxies) {
+                throw InternalProvisionException.circularDependenciesDisabled(
+                        dependency.getKey().getTypeLiteral().getRawType());
+            } else {
                 return t;
             }
+        }
 
         constructionContext.startConstruction();
         try {
             // Optimization: Don't go through the callback stack if we have no listeners.
-            if (!provisionCallback.hasListeners()) {
-                return provision(errors, context, constructionContext);
+            if (provisionCallback == null) {
+                  return provision(context, constructionContext);
             } else {
-                return provisionCallback.provision(errors, context, new ProvisionCallback<T>() {
-                    public T call() throws ErrorsException {
-                        return provision(errors, context, constructionContext);
-                    }
-                });
+                return provisionCallback.provision(context, () ->
+                        provision(context, constructionContext));
             }
         } finally {
             constructionContext.finishConstruction();
@@ -80,12 +83,12 @@ final class ConstructorInjector<T> {
     /**
      * Provisions a new T.
      */
-    private T provision(Errors errors, InternalContext context,
-                        ConstructionContext<T> constructionContext) throws ErrorsException {
+    private T provision(InternalContext context, ConstructionContext<T> constructionContext)
+            throws InternalProvisionException {
         try {
             T t;
             try {
-                Object[] parameters = SingleParameterInjector.getAll(errors, context, parameterInjectors);
+                Object[] parameters = SingleParameterInjector.getAll(context, parameterInjectors);
                 t = constructionProxy.newInstance(parameters);
                 constructionContext.setProxyDelegates(t);
             } finally {
@@ -94,17 +97,17 @@ final class ConstructorInjector<T> {
 
             // Store reference. If an injector re-enters this factory, they'll get the same reference.
             constructionContext.setCurrentReference(t);
-
-            membersInjector.injectMembers(t, errors, context, false);
-            membersInjector.notifyListeners(t, errors);
+            MembersInjectorImpl<T> localMembersInjector = membersInjector;
+            localMembersInjector.injectMembers(t, context, false);
+            localMembersInjector.notifyListeners(t);
 
             return t;
         } catch (InvocationTargetException userException) {
             Throwable cause = userException.getCause() != null
                     ? userException.getCause()
                     : userException;
-            throw errors.withSource(constructionProxy.getInjectionPoint())
-                    .errorInjectingConstructor(cause).toException();
+            throw InternalProvisionException.errorInjectingConstructor(cause)
+                    .addSource(constructionProxy.getInjectionPoint());
         } finally {
             constructionContext.removeCurrentReference();
         }

src/main/java/com/google/inject/internal/ConstructorInjectorStore.java

@@ -8,8 +8,8 @@ import com.google.inject.spi.InjectionPoint;
 final class ConstructorInjectorStore {
     private final InjectorImpl injector;
 
-    private final FailableCache<InjectionPoint, ConstructorInjector<?>> cache
-            = new FailableCache<InjectionPoint, ConstructorInjector<?>>() {
+    private final FailableCache<InjectionPoint, ConstructorInjector<?>> cache =
+            new FailableCache<>() {
         @Override
         protected ConstructorInjector<?> create(InjectionPoint constructorInjector, Errors errors)
                 throws ErrorsException {
@@ -46,12 +46,12 @@ final class ConstructorInjectorStore {
             throws ErrorsException {
         int numErrorsBefore = errors.size();
 
-        SingleParameterInjector<?>[] constructorParameterInjectors
-                = injector.getParametersInjectors(injectionPoint.getDependencies(), errors);
+        SingleParameterInjector<?>[] constructorParameterInjectors =
+                injector.getParametersInjectors(injectionPoint.getDependencies(), errors);
 
         @SuppressWarnings("unchecked") // the injector type agrees with the injection point type
-                MembersInjectorImpl<T> membersInjector = (MembersInjectorImpl<T>) injector.membersInjectorStore
-                .get(injectionPoint.getDeclaringType(), errors);
+        MembersInjectorImpl<T> membersInjector = (MembersInjectorImpl<T>)
+        injector.membersInjectorStore.get(injectionPoint.getDeclaringType(), errors);
 
         ConstructionProxyFactory<T> factory = new DefaultConstructionProxyFactory<T>(injectionPoint);
 

src/main/java/com/google/inject/internal/ContextualCallable.java

@@ -1,5 +0,0 @@
-package com.google.inject.internal;
-
-interface ContextualCallable<T> {
-    T call(InternalContext context) throws ErrorsException;
-}

src/main/java/com/google/inject/internal/CycleDetectingLock.java

@@ -1,7 +1,6 @@
 package com.google.inject.internal;
 
 import com.google.common.base.Preconditions;
-import com.google.common.base.Supplier;
 import com.google.common.collect.ImmutableListMultimap;
 import com.google.common.collect.LinkedHashMultimap;
 import com.google.common.collect.ListMultimap;
@@ -12,7 +11,6 @@ import com.google.common.collect.Multimaps;
 
 import java.util.Collection;
 import java.util.LinkedHashMap;
-import java.util.List;
 import java.util.Map;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
@@ -43,7 +41,7 @@ interface CycleDetectingLock<ID> {
      * In case no cycle is detected performance is O(threads creating singletons),
      * in case cycle is detected performance is O(singleton locks).
      */
-    ListMultimap<Long, ID> lockOrDetectPotentialLocksCycle();
+    ListMultimap<Thread, ID> lockOrDetectPotentialLocksCycle();
 
     /**
      * Unlocks previously locked lock.
@@ -82,7 +80,7 @@ interface CycleDetectingLock<ID> {
          *
          * Guarded by {@code this}.
          */
-        private final Multimap<Long, ReentrantCycleDetectingLock> locksOwnedByThread =
+        private static final Multimap<Thread, ReentrantCycleDetectingLock<?>> locksOwnedByThread =
                 LinkedHashMultimap.create();
         /**
          * Specifies lock that thread is currently waiting on to own it.
@@ -100,22 +98,22 @@ interface CycleDetectingLock<ID> {
          *
          * Guarded by {@code this}.
          */
-        private Map<Long, ReentrantCycleDetectingLock> lockThreadIsWaitingOn = Maps.newHashMap();
+        private static Map<Thread, ReentrantCycleDetectingLock<?>> lockThreadIsWaitingOn = Maps.newHashMap();
 
         /**
          * Creates new lock within this factory context. We can guarantee that locks created by
          * the same factory would not deadlock.
          *
-         * @param newLockId lock id that would be used to report lock cycles if detected
+         * @param userLockId lock id that would be used to report lock cycles if detected
          */
-        CycleDetectingLock<ID> create(ID newLockId) {
-            return new ReentrantCycleDetectingLock(newLockId, new ReentrantLock());
+        CycleDetectingLock<ID> create(ID userLockId) {
+            return new ReentrantCycleDetectingLock<>(this, userLockId, new ReentrantLock());
         }
 
         /**
          * The implementation for {@link CycleDetectingLock}.
          */
-        class ReentrantCycleDetectingLock implements CycleDetectingLock<ID> {
+        static class ReentrantCycleDetectingLock<ID> implements CycleDetectingLock<ID> {
 
             /**
              * Underlying lock used for actual waiting when no potential deadlocks are detected.
@@ -125,50 +123,56 @@ interface CycleDetectingLock<ID> {
              * User id for this lock.
              */
             private final ID userLockId;
+            /** Factory that was used to create this lock. */
+            private final CycleDetectingLockFactory<ID> lockFactory;
             /**
              * Thread id for the thread that owned this lock. Nullable.
              * Guarded by {@code CycleDetectingLockFactory.this}.
              */
-            private Long lockOwnerThreadId = null;
+            private Thread lockOwnerThread = null;
             /**
              * Number of times that thread owned this lock.
              * Guarded by {@code CycleDetectingLockFactory.this}.
              */
             private int lockReentranceCount = 0;
 
-            ReentrantCycleDetectingLock(ID userLockId, Lock lockImplementation) {
+            ReentrantCycleDetectingLock(
+                    CycleDetectingLockFactory<ID> lockFactory, ID userLockId, Lock lockImplementation) {
+                this.lockFactory = lockFactory;
                 this.userLockId = Preconditions.checkNotNull(userLockId, "userLockId");
                 this.lockImplementation = Preconditions.checkNotNull(
                         lockImplementation, "lockImplementation");
             }
 
             @Override
-            public ListMultimap<Long, ID> lockOrDetectPotentialLocksCycle() {
-                final long currentThreadId = Thread.currentThread().getId();
-                synchronized (CycleDetectingLockFactory.this) {
+            public ListMultimap<Thread, ID> lockOrDetectPotentialLocksCycle() {
+                final Thread currentThread = Thread.currentThread();
+                synchronized (CycleDetectingLockFactory.class) {
                     checkState();
-                    ListMultimap<Long, ID> locksInCycle = detectPotentialLocksCycle();
+                    // Add this lock to the waiting map to ensure it is included in any reported lock cycle.
+                    lockThreadIsWaitingOn.put(currentThread, this);
+                    ListMultimap<Thread, ID> locksInCycle = detectPotentialLocksCycle();
                     if (!locksInCycle.isEmpty()) {
+                        // We aren't actually going to wait for this lock, so remove it from the map.
+                        lockThreadIsWaitingOn.remove(currentThread);
                         // potential deadlock is found, we don't try to take this lock
                         return locksInCycle;
                     }
-
-                    lockThreadIsWaitingOn.put(currentThreadId, this);
                 }
 
                 // this may be blocking, but we don't expect it to cause a deadlock
                 lockImplementation.lock();
 
-                synchronized (CycleDetectingLockFactory.this) {
+                synchronized (CycleDetectingLockFactory.class) {
                     // current thread is no longer waiting on this lock
-                    lockThreadIsWaitingOn.remove(currentThreadId);
+                    lockThreadIsWaitingOn.remove(currentThread);
                     checkState();
 
                     // mark it as owned by us
-                    lockOwnerThreadId = currentThreadId;
+                    lockOwnerThread = currentThread;
                     lockReentranceCount++;
                     // add this lock to the list of locks owned by a current thread
-                    locksOwnedByThread.put(currentThreadId, this);
+                    locksOwnedByThread.put(currentThread, this);
                 }
                 // no deadlock is found, locking successful
                 return ImmutableListMultimap.of();
@@ -176,12 +180,12 @@ interface CycleDetectingLock<ID> {
 
             @Override
             public void unlock() {
-                final long currentThreadId = Thread.currentThread().getId();
-                synchronized (CycleDetectingLockFactory.this) {
+                final Thread currentThread = Thread.currentThread();
+                synchronized (CycleDetectingLockFactory.class) {
                     checkState();
-                    Preconditions.checkState(lockOwnerThreadId != null,
+                    Preconditions.checkState(lockOwnerThread != null,
                             "Thread is trying to unlock a lock that is not locked");
-                    Preconditions.checkState(lockOwnerThreadId == currentThreadId,
+                    Preconditions.checkState(lockOwnerThread == currentThread,
                             "Thread is trying to unlock a lock owned by another thread");
 
                     // releasing underlying lock
@@ -191,12 +195,12 @@ interface CycleDetectingLock<ID> {
                     lockReentranceCount--;
                     if (lockReentranceCount == 0) {
                         // we no longer own this lock
-                        lockOwnerThreadId = null;
-                        Preconditions.checkState(locksOwnedByThread.remove(currentThreadId, this),
+                        lockOwnerThread = null;
+                        Preconditions.checkState(locksOwnedByThread.remove(currentThread, this),
                                 "Internal error: Can not find this lock in locks owned by a current thread");
-                        if (locksOwnedByThread.get(currentThreadId).isEmpty()) {
+                        if (locksOwnedByThread.get(currentThread).isEmpty()) {
                             // clearing memory
-                            locksOwnedByThread.removeAll(currentThreadId);
+                            locksOwnedByThread.removeAll(currentThread);
                         }
                     }
                 }
@@ -206,14 +210,14 @@ interface CycleDetectingLock<ID> {
              * Check consistency of an internal state.
              */
             void checkState() throws IllegalStateException {
-                final long currentThreadId = Thread.currentThread().getId();
-                Preconditions.checkState(!lockThreadIsWaitingOn.containsKey(currentThreadId),
+                final Thread currentThread = Thread.currentThread();
+                Preconditions.checkState(!lockThreadIsWaitingOn.containsKey(currentThread),
                         "Internal error: Thread should not be in a waiting thread on a lock now");
-                if (lockOwnerThreadId != null) {
+                if (lockOwnerThread != null) {
                     // check state of a locked lock
                     Preconditions.checkState(lockReentranceCount >= 0,
                             "Internal error: Lock ownership and reentrance count internal states do not match");
-                    Preconditions.checkState(locksOwnedByThread.get(lockOwnerThreadId).contains(this),
+                    Preconditions.checkState(locksOwnedByThread.get(lockOwnerThread).contains(this),
                             "Internal error: Set of locks owned by a current thread and lock "
                                     + "ownership status do not match");
                 } else {
@@ -233,74 +237,80 @@ interface CycleDetectingLock<ID> {
              *
              * @see CycleDetectingLock#lockOrDetectPotentialLocksCycle()
              */
-            private ListMultimap<Long, ID> detectPotentialLocksCycle() {
-                final long currentThreadId = Thread.currentThread().getId();
-                if (lockOwnerThreadId == null || lockOwnerThreadId == currentThreadId) {
+            private ListMultimap<Thread, ID> detectPotentialLocksCycle() {
+                final Thread currentThread = Thread.currentThread();
+                if (lockOwnerThread == null || lockOwnerThread == currentThread) {
                     // if nobody owns this lock, lock cycle is impossible
                     // if a current thread owns this lock, we let Guice to handle it
                     return ImmutableListMultimap.of();
                 }
 
-                ListMultimap<Long, ID> potentialLocksCycle = Multimaps.newListMultimap(
-                        new LinkedHashMap<Long, Collection<ID>>(),
-                        new Supplier<List<ID>>() {
-                            @Override
-                            public List<ID> get() {
-                                return Lists.newArrayList();
-                            }
-                        });
+                ListMultimap<Thread, ID> potentialLocksCycle = Multimaps.newListMultimap(
+                        new LinkedHashMap<>(), Lists::newArrayList);
                 // lock that is a part of a potential locks cycle, starts with current lock
-                ReentrantCycleDetectingLock lockOwnerWaitingOn = this;
+                ReentrantCycleDetectingLock<?> lockOwnerWaitingOn = this;
                 // try to find a dependency path between lock's owner thread and a current thread
-                while (lockOwnerWaitingOn != null && lockOwnerWaitingOn.lockOwnerThreadId != null) {
-                    Long threadOwnerThreadWaits = lockOwnerWaitingOn.lockOwnerThreadId;
+                while (lockOwnerWaitingOn != null && lockOwnerWaitingOn.lockOwnerThread != null) {
+                    Thread threadOwnerThreadWaits = lockOwnerWaitingOn.lockOwnerThread;
                     // in case locks cycle exists lock we're waiting for is part of it
-                    potentialLocksCycle.putAll(threadOwnerThreadWaits,
-                            getAllLockIdsAfter(threadOwnerThreadWaits, lockOwnerWaitingOn));
-
-                    if (threadOwnerThreadWaits == currentThreadId) {
+                    lockOwnerWaitingOn =
+                            addAllLockIdsAfter(threadOwnerThreadWaits, lockOwnerWaitingOn, potentialLocksCycle);
+                    if (threadOwnerThreadWaits == currentThread) {
                         // owner thread depends on current thread, cycle detected
                         return potentialLocksCycle;
                     }
-                    // going for the next thread we wait on indirectly
-                    lockOwnerWaitingOn = lockThreadIsWaitingOn.get(threadOwnerThreadWaits);
                 }
                 // no dependency path from an owner thread to a current thread
                 return ImmutableListMultimap.of();
             }
 
             /**
-             * Return locks owned by a thread after a lock specified, inclusive.
+             * Adds all locks held by the given thread that are after the given lock and then returns the
+             * lock the thread is currently waiting on, if any
              */
-            private List<ID> getAllLockIdsAfter(long threadId, ReentrantCycleDetectingLock lock) {
-                List<ID> ids = Lists.newArrayList();
+            private ReentrantCycleDetectingLock<?> addAllLockIdsAfter(
+                    Thread thread,
+                    ReentrantCycleDetectingLock<?> lock,
+                    ListMultimap<Thread, ID> potentialLocksCycle) {
                 boolean found = false;
-                Collection<ReentrantCycleDetectingLock> ownedLocks = locksOwnedByThread.get(threadId);
+                Collection<ReentrantCycleDetectingLock<?>> ownedLocks = locksOwnedByThread.get(thread);
                 Preconditions.checkNotNull(ownedLocks,
                         "Internal error: No locks were found taken by a thread");
-                for (ReentrantCycleDetectingLock ownedLock : ownedLocks) {
+                for (ReentrantCycleDetectingLock<?> ownedLock : ownedLocks) {
                     if (ownedLock == lock) {
                         found = true;
                     }
-                    if (found) {
-                        ids.add(ownedLock.userLockId);
+                    if (found && ownedLock.lockFactory == this.lockFactory) {
+                        // All locks are stored in a shared map therefore there is no way to
+                        // enforce type safety. We know that our cast is valid as we check for a lock's
+                        // factory. If the lock was generated by the
+                        // same factory it has to have same type as the current lock.
+                        @SuppressWarnings("unchecked")
+                        ID userLockId = (ID) ownedLock.userLockId;
+                        potentialLocksCycle.put(thread, userLockId);
                     }
                 }
-                Preconditions.checkState(found, "Internal error: We can not find locks that "
-                        + "created a cycle that we detected");
-                return ids;
+                Preconditions.checkState(found,
+                        "Internal error: We can not find locks that created a cycle that we detected");
+                ReentrantCycleDetectingLock<?> unownedLock = lockThreadIsWaitingOn.get(thread);
+                // If this thread is waiting for a lock add it to the cycle and return it
+                if (unownedLock != null && unownedLock.lockFactory == this.lockFactory) {
+                    @SuppressWarnings("unchecked")
+                    ID typed = (ID) unownedLock.userLockId;
+                    potentialLocksCycle.put(thread, typed);
+                }
+                return unownedLock;
             }
 
             @Override
             public String toString() {
                 // copy is made to prevent a data race
                 // no synchronization is used, potentially stale data, should be good enough
-                Long localLockOwnerThreadId = this.lockOwnerThreadId;
-                if (localLockOwnerThreadId != null) {
-                    return String.format("CycleDetectingLock[%s][locked by %s]",
-                            userLockId, localLockOwnerThreadId);
+                Thread thread = this.lockOwnerThread;
+                if (thread != null) {
+                    return String.format("%s[%s][locked by %s]", super.toString(), userLockId, thread);
                 } else {
-                    return String.format("CycleDetectingLock[%s][unlocked]", userLockId);
+                    return String.format("%s[%s][unlocked]", super.toString(), userLockId);
                 }
             }
         }

src/main/java/com/google/inject/internal/DeclaredMembers.java

@@ -0,0 +1,81 @@
+package com.google.inject.internal;
+
+import com.google.common.collect.ComparisonChain;
+import com.google.common.collect.Ordering;
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.util.Arrays;
+
+/**
+ * Utility class for retrieving declared fields or methods in a particular order, because the JVM
+ * doesn't guarantee ordering for listing declared methods. We don't externally guarantee an
+ * ordering, but having a consistent ordering allows deterministic behavior and simpler tests.
+ */
+public final class DeclaredMembers {
+
+    private DeclaredMembers() {}
+
+    public static Field[] getDeclaredFields(Class<?> type) {
+        Field[] fields = type.getDeclaredFields();
+        Arrays.sort(fields, FIELD_ORDERING);
+        return fields;
+    }
+
+    public static Method[] getDeclaredMethods(Class<?> type) {
+        Method[] methods = type.getDeclaredMethods();
+        Arrays.sort(methods, METHOD_ORDERING);
+        return methods;
+    }
+
+    /**
+     * An ordering suitable for comparing two classes if they are loaded by the same classloader
+     *
+     * <p>Within a single classloader there can only be one class with a given name, so we just
+     * compare the names.
+     */
+    private static final Ordering<Class<?>> CLASS_ORDERING =
+            new Ordering<>() {
+                @Override
+                public int compare(Class<?> o1, Class<?> o2) {
+                    return o1.getName().compareTo(o2.getName());
+                }
+            };
+
+    /**
+     * An ordering suitable for comparing two fields if they are owned by the same class.
+     *
+     * <p>Within a single class it is sufficent to compare the non-generic field signature which
+     * consists of the field name and type.
+     */
+    private static final Ordering<Field> FIELD_ORDERING =
+            new Ordering<>() {
+                @Override
+                public int compare(Field left, Field right) {
+                    return ComparisonChain.start()
+                            .compare(left.getName(), right.getName())
+                            .compare(left.getType(), right.getType(), CLASS_ORDERING)
+                            .result();
+                }
+            };
+
+    /**
+     * An ordering suitable for comparing two methods if they are owned by the same class.
+     *
+     * <p>Within a single class it is sufficient to compare the non-generic method signature which
+     * consists of the name, return type and parameter types.
+     */
+    private static final Ordering<Method> METHOD_ORDERING =
+            new Ordering<>() {
+                @Override
+                public int compare(Method left, Method right) {
+                    return ComparisonChain.start()
+                            .compare(left.getName(), right.getName())
+                            .compare(left.getReturnType(), right.getReturnType(), CLASS_ORDERING)
+                            .compare(
+                                    Arrays.asList(left.getParameterTypes()),
+                                    Arrays.asList(right.getParameterTypes()),
+                                    CLASS_ORDERING.lexicographical())
+                            .result();
+                }
+            };
+}

src/main/java/com/google/inject/internal/DefaultConstructionProxyFactory.java

@@ -24,13 +24,8 @@ final class DefaultConstructionProxyFactory<T> implements ConstructionProxyFacto
         @SuppressWarnings("unchecked") // the injection point is for a constructor of T
         final Constructor<T> constructor = (Constructor<T>) injectionPoint.getMember();
 
-        // Use FastConstructor if the constructor is public.
-        if (Modifier.isPublic(constructor.getModifiers())) {
-            Class<T> classToConstruct = constructor.getDeclaringClass();
-            if (!Modifier.isPublic(classToConstruct.getModifiers())) {
-                constructor.setAccessible(true);
-            }
-        } else {
+        if (!Modifier.isPublic(constructor.getDeclaringClass().getModifiers()) ||
+                !Modifier.isPublic(constructor.getModifiers())) {
             constructor.setAccessible(true);
         }
 
@@ -38,17 +33,17 @@ final class DefaultConstructionProxyFactory<T> implements ConstructionProxyFacto
             public T newInstance(Object... arguments) throws InvocationTargetException {
                 try {
                     return constructor.newInstance(arguments);
-                } catch (InstantiationException e) {
+                } catch (InstantiationException | IllegalAccessException e) {
                     throw new AssertionError(e); // shouldn't happen, we know this is a concrete type
-                } catch (IllegalAccessException e) {
-                    throw new AssertionError(e); // a security manager is blocking us, we're hosed
                 }
             }
 
+            @Override
             public InjectionPoint getInjectionPoint() {
                 return injectionPoint;
             }
 
+            @Override
             public Constructor<T> getConstructor() {
                 return constructor;
             }

src/main/java/com/google/inject/internal/DeferredLookups.java

@@ -32,13 +32,13 @@ final class DeferredLookups implements Lookups {
     }
 
     public <T> Provider<T> getProvider(Key<T> key) {
-        ProviderLookup<T> lookup = new ProviderLookup<T>(key, key);
+        ProviderLookup<T> lookup = new ProviderLookup<>(key, key);
         lookups.add(lookup);
         return lookup.getProvider();
     }
 
     public <T> MembersInjector<T> getMembersInjector(TypeLiteral<T> type) {
-        MembersInjectorLookup<T> lookup = new MembersInjectorLookup<T>(type, type);
+        MembersInjectorLookup<T> lookup = new MembersInjectorLookup<>(type, type);
         lookups.add(lookup);
         return lookup.getMembersInjector();
     }

src/main/java/com/google/inject/internal/DuplicateElementError.java

@@ -0,0 +1,127 @@
+package com.google.inject.internal;
+
+import com.google.common.collect.ImmutableMultimap;
+import com.google.inject.Binding;
+import com.google.inject.Key;
+import com.google.inject.spi.Dependency;
+import com.google.inject.spi.ErrorDetail;
+import java.util.Collection;
+import java.util.Formatter;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+/**
+ * Error reported by Guice when duplicate elements are found in a {@link Multibinder} that does not
+ * permit duplicates.
+ */
+final class DuplicateElementError<T> extends InternalErrorDetail<DuplicateElementError<T>> {
+    private final Key<Set<T>> setKey;
+    private final ImmutableMultimap<T, Element<T>> elements;
+
+    DuplicateElementError(
+            Key<Set<T>> setKey, List<Binding<T>> bindings, T[] values, List<Object> sources) {
+        this(setKey, indexElements(bindings, values), sources);
+    }
+
+    private DuplicateElementError(
+            Key<Set<T>> setKey, ImmutableMultimap<T, Element<T>> elements, List<Object> sources) {
+        super(
+                ErrorId.DUPLICATE_ELEMENT,
+                String.format("Duplicate elements found in Multibinder %s.", Messages.convert(setKey)),
+                sources,
+                null);
+        this.setKey = setKey;
+        this.elements = elements;
+    }
+
+    @Override
+    protected void formatDetail(List<ErrorDetail<?>> others, Formatter formatter) {
+        formatter.format("%n%s%n", Messages.bold("Duplicates:"));
+        int duplicateIndex = 1;
+        for (Map.Entry<T, Collection<Element<T>>> entry : elements.asMap().entrySet()) {
+            formatter.format("%-2s: ", duplicateIndex++);
+            if (entry.getValue().size() > 1) {
+                Set<String> valuesAsString =
+                        entry.getValue().stream()
+                                .map(element -> element.value.toString())
+                                .collect(Collectors.toSet());
+                if (valuesAsString.size() == 1) {
+                    // String representation of the duplicates elements are the same, so only print out one.
+                    formatter.format("Element: %s%n", Messages.redBold(valuesAsString.iterator().next()));
+                    formatter.format("    Bound at:%n");
+                    int index = 1;
+                    for (Element<T> element : entry.getValue()) {
+                        formatter.format("    %-2s: ", index++);
+                        formatElement(element, formatter);
+                    }
+                } else {
+                    // Print out all elements as string when there are different string representations of the
+                    // elements. To keep the logic simple, same strings are not grouped together unless all
+                    // elements have the same string represnetation. This means some strings may be printed
+                    // out multiple times.
+                    // There is no indentation for the first duplicate element.
+                    boolean indent = false;
+                    for (Element<T> element : entry.getValue()) {
+                        if (indent) {
+                            formatter.format("    ");
+                        } else {
+                            indent = true;
+                        }
+                        formatter.format("Element: %s%n", Messages.redBold(element.value.toString()));
+                        formatter.format("    Bound at: ");
+                        formatElement(element, formatter);
+                    }
+                }
+            }
+        }
+        formatter.format("%n%s%n", Messages.bold("Multibinder declared at:"));
+        // Multibinder source includes the key of the set. Filter it out since it's not useful in the
+        // printed error stack.
+        List<Object> filteredSource =
+                getSources().stream()
+                        .filter(
+                                source -> {
+                                    if (source instanceof Dependency) {
+                                        return !((Dependency<?>) source).getKey().equals(setKey);
+                                    }
+                                    return true;
+                                })
+                        .collect(Collectors.toList());
+        ErrorFormatter.formatSources(filteredSource, formatter);
+    }
+
+    private void formatElement(Element<T> element, Formatter formatter) {
+        Object source = element.binding.getSource();
+        new SourceFormatter(
+                source,
+                formatter,
+                /** omitPreposition= */
+                true)
+                .format();
+    }
+
+    @Override
+    public DuplicateElementError<T> withSources(List<Object> newSources) {
+        return new DuplicateElementError<>(setKey, elements, newSources);
+    }
+
+    static <T> ImmutableMultimap<T, Element<T>> indexElements(List<Binding<T>> bindings, T[] values) {
+        ImmutableMultimap.Builder<T, Element<T>> map = ImmutableMultimap.builder();
+        for (int i = 0; i < values.length; i++) {
+            map.put(values[i], new Element<T>(values[i], bindings.get(i)));
+        }
+        return map.build();
+    }
+
+    static class Element<T> {
+        T value;
+        Binding<T> binding;
+
+        Element(T value, Binding<T> binding) {
+            this.value = value;
+            this.binding = binding;
+        }
+    }
+}

src/main/java/com/google/inject/internal/DuplicateMapKeyError.java

@@ -0,0 +1,70 @@
+package com.google.inject.internal;
+
+import com.google.common.collect.Multimap;
+import com.google.inject.Binding;
+import com.google.inject.Key;
+import com.google.inject.spi.ErrorDetail;
+import java.util.Collection;
+import java.util.Formatter;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Error reported by Guice when a duplicate key is found in a {@link MapBinder} that does not permit
+ * duplicates.
+ */
+final class DuplicateMapKeyError<K, V> extends InternalErrorDetail<DuplicateMapKeyError<K, V>> {
+    private final Key<Map<K, V>> mapKey;
+    private final Multimap<K, Binding<V>> duplicates;
+
+    DuplicateMapKeyError(
+            Key<Map<K, V>> mapKey, Multimap<K, Binding<V>> duplicates, List<Object> sources) {
+        super(ErrorId.DUPLICATE_MAP_KEY, getDuplicateKeysMessage(mapKey, duplicates), sources, null);
+        this.mapKey = mapKey;
+        this.duplicates = duplicates;
+    }
+
+    @Override
+    protected final void formatDetail(List<ErrorDetail<?>> others, Formatter formatter) {
+        formatter.format("%n%s%n", Messages.bold("Duplicates:"));
+
+        for (Map.Entry<K, Collection<Binding<V>>> entry : duplicates.asMap().entrySet()) {
+            formatter.format("  Key: \"%s\"%n", Messages.redBold(entry.getKey().toString()));
+            formatter.format("  Bound at:%n");
+            int index = 1;
+            for (Binding<V> binding : entry.getValue()) {
+                formatter.format("    %-2s: ", index++);
+                new SourceFormatter(
+                        binding.getSource(),
+                        formatter,
+                        /** omitPreposition= */
+                        true)
+                        .format();
+            }
+            formatter.format("%n");
+        }
+
+        formatter.format("%s%n", Messages.bold("MapBinder declared at:"));
+        ErrorFormatter.formatSources(getSources(), formatter);
+    }
+
+    @Override
+    public DuplicateMapKeyError<K, V> withSources(List<Object> newSources) {
+        return new DuplicateMapKeyError<>(mapKey, duplicates, newSources);
+    }
+
+    private static <K, V> String getDuplicateKeysMessage(
+            Key<Map<K, V>> mapKey, Multimap<K, Binding<V>> duplicates) {
+        Set<K> duplicateKeys = duplicates.keySet();
+        String mapBinderKey = Messages.convert(mapKey).toString();
+        String firstDuplicateKey = duplicateKeys.iterator().next().toString();
+        if (duplicateKeys.size() == 1) {
+            return String.format("Duplicate key \"%s\" found in %s.", firstDuplicateKey, mapBinderKey);
+        } else {
+            return String.format(
+                    "\"%s\" and %s other duplicate keys found in %s.",
+                    firstDuplicateKey, duplicateKeys.size() - 1, mapBinderKey);
+        }
+    }
+}

src/main/java/com/google/inject/internal/Element.java

@@ -1,4 +1,4 @@
-package com.google.inject.multibindings;
+package com.google.inject.internal;
 
 import com.google.inject.BindingAnnotation;
 
@@ -25,7 +25,6 @@ import static java.lang.annotation.RetentionPolicy.RUNTIME;
 
     enum Type {
         MAPBINDER,
-        MULTIBINDER,
-        OPTIONALBINDER;
+        MULTIBINDER;
     }
 }

src/main/java/com/google/inject/internal/EncounterImpl.java

@@ -43,6 +43,7 @@ final class EncounterImpl<T> implements TypeEncounter<T> {
                 : ImmutableSet.copyOf(injectionListeners);
     }
 
+    @Override
     public void register(MembersInjector<? super T> membersInjector) {
         checkState(valid, "Encounters may not be used after hear() returns.");
 
@@ -53,6 +54,7 @@ final class EncounterImpl<T> implements TypeEncounter<T> {
         membersInjectors.add(membersInjector);
     }
 
+    @Override
     public void register(InjectionListener<? super T> injectionListener) {
         checkState(valid, "Encounters may not be used after hear() returns.");
 
@@ -63,35 +65,42 @@ final class EncounterImpl<T> implements TypeEncounter<T> {
         injectionListeners.add(injectionListener);
     }
 
+    @Override
     public void addError(String message, Object... arguments) {
         checkState(valid, "Encounters may not be used after hear() returns.");
         errors.addMessage(message, arguments);
     }
 
+    @Override
     public void addError(Throwable t) {
         checkState(valid, "Encounters may not be used after hear() returns.");
         errors.errorInUserCode(t, "An exception was caught and reported. Message: %s", t.getMessage());
     }
 
+    @Override
     public void addError(Message message) {
         checkState(valid, "Encounters may not be used after hear() returns.");
         errors.addMessage(message);
     }
 
+    @Override
     public <T> Provider<T> getProvider(Key<T> key) {
         checkState(valid, "Encounters may not be used after hear() returns.");
         return lookups.getProvider(key);
     }
 
+    @Override
     public <T> Provider<T> getProvider(Class<T> type) {
         return getProvider(Key.get(type));
     }
 
+    @Override
     public <T> MembersInjector<T> getMembersInjector(TypeLiteral<T> typeLiteral) {
         checkState(valid, "Encounters may not be used after hear() returns.");
         return lookups.getMembersInjector(typeLiteral);
     }
 
+    @Override
     public <T> MembersInjector<T> getMembersInjector(Class<T> type) {
         return getMembersInjector(TypeLiteral.get(type));
     }

src/main/java/com/google/inject/internal/ErrorFormatter.java

@@ -0,0 +1,33 @@
+package com.google.inject.internal;
+
+import java.util.Formatter;
+import java.util.List;
+
+/** Helper for formatting Guice errors. */
+final class ErrorFormatter {
+    private ErrorFormatter() {}
+
+    /**
+     * Format a list of sources to the given {@code formatter}, prefixed by the give {@code index}.
+     */
+    static void formatSources(int index, List<Object> sources, Formatter formatter) {
+        for (int i = 0; i < sources.size(); i++) {
+            Object source = sources.get(i);
+            if (i == 0) {
+                formatter.format("%-3s: ", index);
+            } else {
+                formatter.format(SourceFormatter.INDENT);
+            }
+            new SourceFormatter(source, formatter, i == 0).format();
+        }
+    }
+
+    /** Format a list of sources to the given {@code formatter}. */
+    static void formatSources(List<Object> sources, Formatter formatter) {
+        for (int i = 0; i < sources.size(); i++) {
+            Object source = sources.get(i);
+            formatter.format("  ");
+            new SourceFormatter(source, formatter, i == 0).format();
+        }
+    }
+}

src/main/java/com/google/inject/internal/ErrorId.java

@@ -0,0 +1,65 @@
+package com.google.inject.internal;
+
+/** Enum used to identify a specific Guice error. */
+public enum ErrorId {
+    AMBIGUOUS_TYPE_CONVERSION,
+    AOP_DISABLED,
+    AT_INJECT_REQUIRED,
+    AT_TARGET_IS_MISSING_PARAMETER,
+    BINDING_ALREADY_SET,
+    BINDING_TO_GUICE_TYPE,
+    BINDING_TO_PROVIDER,
+    CAN_NOT_PROXY_CLASS,
+    CHILD_BINDING_ALREADY_SET,
+    CIRCULAR_PROXY_DISABLED,
+    CONSTRUCTOR_NOT_DEFINED_BY_TYPE,
+    CONVERSION_TYPE_ERROR,
+    CONVERTER_RETURNED_NULL,
+    DUPLICATE_BINDING_ANNOTATIONS,
+    DUPLICATE_ELEMENT,
+    DUPLICATE_MAP_KEY,
+    DUPLICATE_SCOPES,
+    DUPLICATE_SCOPE_ANNOTATIONS,
+    ERROR_ENHANCING_CLASS,
+    ERROR_INJECTING_CONSTRUCTOR,
+    ERROR_INJECTING_METHOD,
+    ERROR_IN_CUSTOM_PROVIDER,
+    ERROR_IN_USER_CODE,
+    ERROR_IN_USER_INJECTOR,
+    ERROR_NOTIFYING_TYPE_LISTENER,
+    EXPOSED_BUT_NOT_BOUND,
+    INJECT_ABSTRACT_METHOD,
+    INJECT_FINAL_FIELD,
+    INJECT_INNER_CLASS,
+    INJECT_METHOD_WITH_TYPE_PARAMETER,
+    INJECT_RAW_MEMBERS_INJECTOR,
+    INJECT_RAW_PROVIDER,
+    INJECT_RAW_TYPE_LITERAL,
+    JIT_BINDING_ALREADY_SET,
+    JIT_DISABLED,
+    JIT_DISABLED_IN_PARENT,
+    KEY_NOT_FULLY_SPECIFIED,
+    MISPLACED_BINDING_ANNOTATION,
+    MISSING_CONSTANT_VALUES,
+    MISSING_CONSTRUCTOR,
+    MISSING_IMPLEMENTATION,
+    MISSING_RUNTIME_RETENTION,
+    MISSING_SCOPE_ANNOTATION,
+    NOT_A_SUBTYPE,
+    NULL_ELEMENT_IN_SET,
+    NULL_INJECTED_INTO_NON_NULLABLE,
+    NULL_VALUE_IN_MAP,
+    OPTIONAL_CONSTRUCTOR,
+    RECURSIVE_BINDING,
+    RECURSIVE_IMPLEMENTATION_TYPE,
+    RECURSIVE_PROVIDER_TYPE,
+    SCOPE_ANNOTATION_ON_ABSTRACT_TYPE,
+    SCOPE_NOT_FOUND,
+    STATIC_INJECTION_ON_INTERFACE,
+    SUBTYPE_NOT_PROVIDED,
+    TOO_MANY_CONSTRUCTORS,
+    VOID_PROVIDER_METHOD,
+
+    // All other uncommon type of errors
+    OTHER;
+}

src/main/java/com/google/inject/internal/ErrorsException.java

@@ -8,6 +8,9 @@ package com.google.inject.internal;
 @SuppressWarnings("serial")
 public class ErrorsException extends Exception {
 
+    // NOTE: this is used by Gin which is abandoned.  So changing this API will prevent Gin users from
+    // upgrading Guice version.
+
     private final Errors errors;
 
     public ErrorsException(Errors errors) {

src/main/java/com/google/inject/internal/Exceptions.java

@@ -1,46 +0,0 @@
-package com.google.inject.internal;
-
-/**
- * Rethrows user-code exceptions in wrapped exceptions so that Errors can target the correct
- * exception.
- */
-class Exceptions {
-
-    /**
-     * Rethrows the exception (or it's cause, if it has one) directly if possible.
-     * If it was a checked exception, this wraps the exception in a stack trace
-     * with no frames, so that the exception is shown immediately with no frames
-     * above it.
-     */
-    public static RuntimeException rethrowCause(Throwable throwable) {
-        Throwable cause = throwable;
-        if (cause.getCause() != null) {
-            cause = cause.getCause();
-        }
-        return rethrow(cause);
-    }
-
-    /**
-     * Rethrows the exception.
-     */
-    public static RuntimeException rethrow(Throwable throwable) {
-        if (throwable instanceof RuntimeException) {
-            throw (RuntimeException) throwable;
-        } else if (throwable instanceof Error) {
-            throw (Error) throwable;
-        } else {
-            throw new UnhandledCheckedUserException(throwable);
-        }
-    }
-
-    /**
-     * A marker exception class that we look for in order to unwrap the exception
-     * into the user exception, to provide a cleaner stack trace.
-     */
-    @SuppressWarnings("serial")
-    static class UnhandledCheckedUserException extends RuntimeException {
-        public UnhandledCheckedUserException(Throwable cause) {
-            super(cause);
-        }
-    }
-}

src/main/java/com/google/inject/internal/ExposedBindingImpl.java

@@ -22,14 +22,17 @@ public final class ExposedBindingImpl<T> extends BindingImpl<T> implements Expos
         this.privateElements = privateElements;
     }
 
+    @Override
     public <V> V acceptTargetVisitor(BindingTargetVisitor<? super T, V> visitor) {
         return visitor.visit(this);
     }
 
+    @Override
     public Set<Dependency<?>> getDependencies() {
         return ImmutableSet.<Dependency<?>>of(Dependency.get(Key.get(Injector.class)));
     }
 
+    @Override
     public PrivateElements getPrivateElements() {
         return privateElements;
     }

src/main/java/com/google/inject/internal/ExposedKeyFactory.java

@@ -18,9 +18,10 @@ final class ExposedKeyFactory<T> implements InternalFactory<T>, CreationListener
         this.privateElements = privateElements;
     }
 
+    @Override
     public void notify(Errors errors) {
         InjectorImpl privateInjector = (InjectorImpl) privateElements.getInjector();
-        BindingImpl<T> explicitBinding = privateInjector.state.getExplicitBinding(key);
+        BindingImpl<T> explicitBinding = privateInjector.getBindingData().getExplicitBinding(key);
 
         // validate that the child injector has its own factory. If the getInternalFactory() returns
         // this, then that child injector doesn't have a factory (and getExplicitBinding has returned
@@ -33,8 +34,10 @@ final class ExposedKeyFactory<T> implements InternalFactory<T>, CreationListener
         this.delegate = explicitBinding;
     }
 
-    public T get(Errors errors, InternalContext context, Dependency<?> dependency, boolean linked)
-            throws ErrorsException {
-        return delegate.getInternalFactory().get(errors, context, dependency, linked);
+    @Override
+    public T get(InternalContext context, Dependency<?> dependency, boolean linked)
+            throws InternalProvisionException {
+        // TODO(lukes): add a source to the thrown exception?
+        return delegate.getInternalFactory().get(context, dependency, linked);
     }
 }

src/main/java/com/google/inject/internal/ExposureBuilder.java

@@ -27,12 +27,14 @@ public class ExposureBuilder<T> implements AnnotatedElementBuilder {
         }
     }
 
+    @Override
     public void annotatedWith(Class<? extends Annotation> annotationType) {
         Preconditions.checkNotNull(annotationType, "annotationType");
         checkNotAnnotated();
         key = Key.get(key.getTypeLiteral(), annotationType);
     }
 
+    @Override
     public void annotatedWith(Annotation annotation) {
         Preconditions.checkNotNull(annotation, "annotation");
         checkNotAnnotated();

src/main/java/com/google/inject/internal/FactoryProxy.java

@@ -25,6 +25,7 @@ final class FactoryProxy<T> implements InternalFactory<T>, CreationListener {
         this.source = source;
     }
 
+    @Override
     public void notify(final Errors errors) {
         try {
             targetFactory = injector.getInternalFactory(targetKey, errors.withSource(source), JitLimitation.NEW_OR_EXISTING_JIT);
@@ -33,11 +34,15 @@ final class FactoryProxy<T> implements InternalFactory<T>, CreationListener {
         }
     }
 
-    public T get(Errors errors, InternalContext context, Dependency<?> dependency, boolean linked)
-            throws ErrorsException {
-        context.pushState(targetKey, source);
+    @Override
+    public T get(InternalContext context, Dependency<?> dependency, boolean linked)
+            throws InternalProvisionException {
+        Key<? extends T> localTargetKey = targetKey;
+        context.pushState(localTargetKey, source);
         try {
-            return targetFactory.get(errors.withSource(targetKey), context, dependency, true);
+            return targetFactory.get(context, dependency, true);
+        } catch (InternalProvisionException ipe) {
+            throw ipe.addSource(localTargetKey);
         } finally {
             context.popState();
         }

src/main/java/com/google/inject/internal/FailableCache.java

@@ -3,6 +3,9 @@ package com.google.inject.internal;
 import com.google.common.cache.CacheBuilder;
 import com.google.common.cache.CacheLoader;
 import com.google.common.cache.LoadingCache;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Maps;
+import java.util.Map;
 
 /**
  * Lazily creates (and caches) values for keys. If creating the value fails (with errors), an
@@ -10,8 +13,8 @@ import com.google.common.cache.LoadingCache;
  */
 public abstract class FailableCache<K, V> {
 
-    private final LoadingCache<K, Object> delegate = CacheBuilder.newBuilder().build(
-            new CacheLoader<K, Object>() {
+    private final LoadingCache<K, Object> delegate = CacheBuilder.newBuilder()
+            .build(new CacheLoader<>() {
                 public Object load(K key) {
                     Errors errors = new Errors();
                     V result = null;
@@ -41,4 +44,14 @@ public abstract class FailableCache<K, V> {
     boolean remove(K key) {
         return delegate.asMap().remove(key) != null;
     }
+
+    Map<K, V> asMap() {
+        return Maps.transformValues(Maps.filterValues(ImmutableMap.copyOf(delegate.asMap()),
+                        resultOrError -> !(resultOrError instanceof Errors)),
+                resultOrError -> {
+                    @SuppressWarnings("unchecked") // create returned a non-error result, so this is safe
+                    V result = (V) resultOrError;
+                    return result;
+                });
+    }
 }

src/main/java/com/google/inject/internal/GenericErrorDetail.java

@@ -0,0 +1,34 @@
+package com.google.inject.internal;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.Lists;
+import com.google.inject.spi.ErrorDetail;
+import java.io.Serializable;
+import java.util.Formatter;
+import java.util.List;
+
+/** Generic error message representing a Guice internal error. */
+public final class GenericErrorDetail extends InternalErrorDetail<GenericErrorDetail>
+        implements Serializable {
+    public GenericErrorDetail(
+            ErrorId errorId, String message, List<Object> sources, Throwable cause) {
+        super(errorId, checkNotNull(message, "message"), sources, cause);
+    }
+
+    @Override
+    public void formatDetail(List<ErrorDetail<?>> mergeableErrors, Formatter formatter) {
+        Preconditions.checkArgument(mergeableErrors.isEmpty(), "Unexpected mergeable errors");
+        List<Object> dependencies = getSources();
+        for (Object source : Lists.reverse(dependencies)) {
+            formatter.format("  ");
+            new SourceFormatter(source, formatter, /* omitPreposition= */ false).format();
+        }
+    }
+
+    @Override
+    public GenericErrorDetail withSources(List<Object> newSources) {
+        return new GenericErrorDetail(errorId, getMessage(), newSources, getCause());
+    }
+}

src/main/java/com/google/inject/internal/GuiceInternal.java

@@ -0,0 +1,14 @@
+package com.google.inject.internal;
+
+/**
+ * Class used for restricting APIs in other packages to only be used by this package.
+ *
+ * <p>Other packages can reference this class but only this package can reference an instance of it,
+ * so adding this class as a method param ensures that only this package can call it (provided null
+ * is disallowed).
+ */
+public final class GuiceInternal {
+  static final GuiceInternal GUICE_INTERNAL = new GuiceInternal();
+
+  private GuiceInternal() {}
+}

src/main/java/com/google/inject/internal/Indexer.java

@@ -1,4 +1,4 @@
-package com.google.inject.multibindings;
+package com.google.inject.internal;
 
 import com.google.common.base.Objects;
 import com.google.inject.Binding;
@@ -23,17 +23,22 @@ import java.lang.annotation.Annotation;
 /**
  * Visits bindings to return a {@code IndexedBinding} that can be used to emulate the binding
  * deduplication that Guice internally performs.
+ *
+ * <p>Note: simply using equals/hashCode on the BindingImpls doesn't work because they all have
+ * unique annotations. This works around that by reimplementing equality semantics that ignores
+ * {@link Element#uniqueId()}. A better solution might be to introduce the idea of an 'anonymous'
+ * binding to guice, that might support this usecase directly.
  */
-class Indexer extends DefaultBindingTargetVisitor<Object, Indexer.IndexedBinding>
+public class Indexer extends DefaultBindingTargetVisitor<Object, Indexer.IndexedBinding>
         implements BindingScopingVisitor<Object> {
     private static final Object EAGER_SINGLETON = new Object();
-    final Injector injector;
+    private final Injector injector;
 
-    Indexer(Injector injector) {
+    public Indexer(Injector injector) {
         this.injector = injector;
     }
 
-    boolean isIndexable(Binding<?> binding) {
+    public boolean isIndexable(Binding<?> binding) {
         return binding.getKey().getAnnotation() instanceof Element;
     }
 
@@ -126,7 +131,7 @@ class Indexer extends DefaultBindingTargetVisitor<Object, Indexer.IndexedBinding
         PROVIDED_BY,
     }
 
-    static class IndexedBinding {
+    public static class IndexedBinding {
         final String annotationName;
         final Element.Type annotationType;
         final TypeLiteral<?> typeLiteral;
@@ -134,7 +139,7 @@ class Indexer extends DefaultBindingTargetVisitor<Object, Indexer.IndexedBinding
         final BindingType type;
         final Object extraEquality;
 
-        IndexedBinding(Binding<?> binding, BindingType type, Object scope, Object extraEquality) {
+        public IndexedBinding(Binding<?> binding, BindingType type, Object scope, Object extraEquality) {
             this.scope = scope;
             this.type = type;
             this.extraEquality = extraEquality;

src/main/java/com/google/inject/internal/InheritingState.java

@@ -1,160 +0,0 @@
-package com.google.inject.internal;
-
-import com.google.common.collect.ImmutableMap;
-import com.google.common.collect.Lists;
-import com.google.common.collect.Maps;
-import com.google.inject.Binding;
-import com.google.inject.Key;
-import com.google.inject.Scope;
-import com.google.inject.TypeLiteral;
-import com.google.inject.spi.ModuleAnnotatedMethodScannerBinding;
-import com.google.inject.spi.ProvisionListenerBinding;
-import com.google.inject.spi.ScopeBinding;
-import com.google.inject.spi.TypeConverterBinding;
-import com.google.inject.spi.TypeListenerBinding;
-
-import java.lang.annotation.Annotation;
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-
-final class InheritingState implements State {
-
-    private final State parent;
-
-    // Must be a linked hashmap in order to preserve order of bindings in Modules.
-    private final Map<Key<?>, Binding<?>> explicitBindingsMutable = Maps.newLinkedHashMap();
-    private final Map<Key<?>, Binding<?>> explicitBindings
-            = Collections.unmodifiableMap(explicitBindingsMutable);
-    private final Map<Class<? extends Annotation>, ScopeBinding> scopes = Maps.newHashMap();
-    private final List<TypeConverterBinding> converters = Lists.newArrayList();
-    private final List<TypeListenerBinding> typeListenerBindings = Lists.newArrayList();
-    private final List<ProvisionListenerBinding> provisionListenerBindings = Lists.newArrayList();
-    private final List<ModuleAnnotatedMethodScannerBinding> scannerBindings = Lists.newArrayList();
-    private final WeakKeySet blacklistedKeys;
-    private final Object lock;
-
-    InheritingState(State parent) {
-        this.parent = checkNotNull(parent, "parent");
-        this.lock = (parent == State.NONE) ? this : parent.lock();
-        this.blacklistedKeys = new WeakKeySet(lock);
-    }
-
-    public State parent() {
-        return parent;
-    }
-
-    @SuppressWarnings("unchecked") // we only put in BindingImpls that match their key types
-    public <T> BindingImpl<T> getExplicitBinding(Key<T> key) {
-        Binding<?> binding = explicitBindings.get(key);
-        return binding != null ? (BindingImpl<T>) binding : parent.getExplicitBinding(key);
-    }
-
-    public Map<Key<?>, Binding<?>> getExplicitBindingsThisLevel() {
-        return explicitBindings;
-    }
-
-    public void putBinding(Key<?> key, BindingImpl<?> binding) {
-        explicitBindingsMutable.put(key, binding);
-    }
-
-    public ScopeBinding getScopeBinding(Class<? extends Annotation> annotationType) {
-        ScopeBinding scopeBinding = scopes.get(annotationType);
-        return scopeBinding != null ? scopeBinding : parent.getScopeBinding(annotationType);
-    }
-
-    public void putScopeBinding(Class<? extends Annotation> annotationType, ScopeBinding scope) {
-        scopes.put(annotationType, scope);
-    }
-
-    public Iterable<TypeConverterBinding> getConvertersThisLevel() {
-        return converters;
-    }
-
-    public void addConverter(TypeConverterBinding typeConverterBinding) {
-        converters.add(typeConverterBinding);
-    }
-
-    public TypeConverterBinding getConverter(
-            String stringValue, TypeLiteral<?> type, Errors errors, Object source) {
-        TypeConverterBinding matchingConverter = null;
-        for (State s = this; s != State.NONE; s = s.parent()) {
-            for (TypeConverterBinding converter : s.getConvertersThisLevel()) {
-                if (converter.getTypeMatcher().matches(type)) {
-                    if (matchingConverter != null) {
-                        errors.ambiguousTypeConversion(stringValue, source, type, matchingConverter, converter);
-                    }
-                    matchingConverter = converter;
-                }
-            }
-        }
-        return matchingConverter;
-    }
-
-    public void addTypeListener(TypeListenerBinding listenerBinding) {
-        typeListenerBindings.add(listenerBinding);
-    }
-
-    public List<TypeListenerBinding> getTypeListenerBindings() {
-        List<TypeListenerBinding> parentBindings = parent.getTypeListenerBindings();
-        List<TypeListenerBinding> result =
-                Lists.newArrayListWithCapacity(parentBindings.size() + typeListenerBindings.size());
-        result.addAll(parentBindings);
-        result.addAll(typeListenerBindings);
-        return result;
-    }
-
-    public void addProvisionListener(ProvisionListenerBinding listenerBinding) {
-        provisionListenerBindings.add(listenerBinding);
-    }
-
-    public List<ProvisionListenerBinding> getProvisionListenerBindings() {
-        List<ProvisionListenerBinding> parentBindings = parent.getProvisionListenerBindings();
-        List<ProvisionListenerBinding> result =
-                Lists.newArrayListWithCapacity(parentBindings.size() + provisionListenerBindings.size());
-        result.addAll(parentBindings);
-        result.addAll(provisionListenerBindings);
-        return result;
-    }
-
-    public void addScanner(ModuleAnnotatedMethodScannerBinding scanner) {
-        scannerBindings.add(scanner);
-    }
-
-    public List<ModuleAnnotatedMethodScannerBinding> getScannerBindings() {
-        List<ModuleAnnotatedMethodScannerBinding> parentBindings = parent.getScannerBindings();
-        List<ModuleAnnotatedMethodScannerBinding> result =
-                Lists.newArrayListWithCapacity(parentBindings.size() + scannerBindings.size());
-        result.addAll(parentBindings);
-        result.addAll(scannerBindings);
-        return result;
-    }
-
-    public void blacklist(Key<?> key, State state, Object source) {
-        parent.blacklist(key, state, source);
-        blacklistedKeys.add(key, state, source);
-    }
-
-    public boolean isBlacklisted(Key<?> key) {
-        return blacklistedKeys.contains(key);
-    }
-
-    public Set<Object> getSourcesForBlacklistedKey(Key<?> key) {
-        return blacklistedKeys.getSources(key);
-    }
-
-    public Object lock() {
-        return lock;
-    }
-
-    public Map<Class<? extends Annotation>, Scope> getScopes() {
-        ImmutableMap.Builder<Class<? extends Annotation>, Scope> builder = ImmutableMap.builder();
-        for (Map.Entry<Class<? extends Annotation>, ScopeBinding> entry : scopes.entrySet()) {
-            builder.put(entry.getKey(), entry.getValue().getScope());
-        }
-        return builder.build();
-    }
-}

src/main/java/com/google/inject/internal/Initializable.java

@@ -8,5 +8,5 @@ interface Initializable<T> {
     /**
      * Ensures the reference is initialized, then returns it.
      */
-    T get(Errors errors) throws ErrorsException;
+    T get() throws InternalProvisionException;
 }

src/main/java/com/google/inject/internal/Initializables.java

@@ -6,8 +6,8 @@ final class Initializables {
      * Returns an initializable for an instance that requires no initialization.
      */
     static <T> Initializable<T> of(final T instance) {
-        return new Initializable<T>() {
-            public T get(Errors errors) throws ErrorsException {
+        return new Initializable<>() {
+            public T get() {
                 return instance;
             }
 

src/main/java/com/google/inject/internal/Initializer.java

@@ -3,15 +3,16 @@ package com.google.inject.internal;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
+import com.google.common.collect.Multimap;
 import com.google.inject.Binding;
 import com.google.inject.Key;
 import com.google.inject.Stage;
 import com.google.inject.TypeLiteral;
 import com.google.inject.spi.InjectionPoint;
 
-import java.util.Map;
+import java.util.IdentityHashMap;
+import java.util.List;
 import java.util.Set;
-import java.util.concurrent.CountDownLatch;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
@@ -23,27 +24,30 @@ import static com.google.common.base.Preconditions.checkNotNull;
  */
 final class Initializer {
 
-    /**
-     * the only thread that we'll use to inject members.
-     */
-    private final Thread creatingThread = Thread.currentThread();
+    /** Is set to true once {@link #validateOustandingInjections} is called. */
+    private volatile boolean validationStarted = false;
 
     /**
-     * zero means everything is injected.
+     * Allows us to detect circular dependencies. It's only used during injectable reference
+     * initialization. After initialization direct access through volatile field is used.
      */
-    private final CountDownLatch ready = new CountDownLatch(1);
+    private final CycleDetectingLock.CycleDetectingLockFactory<Class<?>> cycleDetectingLockFactory =
+            new CycleDetectingLock.CycleDetectingLockFactory<>();
 
     /**
-     * Maps from instances that need injection to the MembersInjector that will inject them.
+     * Instances that need injection during injector creation to a source that registered them. New
+     * references added before {@link #validateOustandingInjections}. Cleared up in {@link
+     * #injectAll}.
      */
-    private final Map<Object, MembersInjectorImpl<?>> pendingMembersInjectors =
+    private final List<InjectableReference<?>> pendingInjections = Lists.newArrayList();
+
+    /**
+     * Map that guarantees that no instance would get two references. New references added before
+     * {@link #validateOustandingInjections}. Cleared up in {@link #validateOustandingInjections}.
+     */
+    private final IdentityHashMap<Object, InjectableReference<?>> initializablesCache =
             Maps.newIdentityHashMap();
 
-    /**
-     * Maps instances that need injection to a source that registered them
-     */
-    private final Map<Object, InjectableReference<?>> pendingInjection = Maps.newIdentityHashMap();
-
     /**
      * Registers an instance for member injection when that step is performed.
      *
@@ -55,21 +59,35 @@ final class Initializer {
     <T> Initializable<T> requestInjection(InjectorImpl injector, T instance, Binding<T> binding,
                                           Object source, Set<InjectionPoint> injectionPoints) {
         checkNotNull(source);
-
+        Preconditions.checkState(
+                !validationStarted, "Member injection could not be requested after validation is started");
         ProvisionListenerStackCallback<T> provisionCallback =
                 binding == null ? null : injector.provisionListenerStore.get(binding);
 
         // short circuit if the object has no injections or listeners.
         if (instance == null || (injectionPoints.isEmpty()
                 && !injector.membersInjectorStore.hasTypeListeners()
-                && (provisionCallback == null || !provisionCallback.hasListeners()))) {
+                && (provisionCallback == null))) {
             return Initializables.of(instance);
         }
 
-        InjectableReference<T> initializable = new InjectableReference<T>(
-                injector, instance, binding == null ? null : binding.getKey(), provisionCallback, source);
-        pendingInjection.put(instance, initializable);
-        return initializable;
+        if (initializablesCache.containsKey(instance)) {
+            @SuppressWarnings("unchecked") // Map from T to InjectableReference<T>
+                    Initializable<T> cached = (Initializable<T>) initializablesCache.get(instance);
+            return cached;
+        }
+
+        InjectableReference<T> injectableReference =
+                new InjectableReference<T>(
+                        injector,
+                        instance,
+                        binding == null ? null : binding.getKey(),
+                        provisionCallback,
+                        source,
+                        cycleDetectingLockFactory.create(instance.getClass()));
+        initializablesCache.put(instance, injectableReference);
+        pendingInjections.add(injectableReference);
+        return injectableReference;
     }
 
     /**
@@ -77,9 +95,11 @@ final class Initializer {
      * on the injected instances.
      */
     void validateOustandingInjections(Errors errors) {
-        for (InjectableReference<?> reference : pendingInjection.values()) {
+        validationStarted = true;
+        initializablesCache.clear();
+        for (InjectableReference<?> reference : pendingInjections) {
             try {
-                pendingMembersInjectors.put(reference.instance, reference.validate(errors));
+                reference.validate(errors);
             } catch (ErrorsException e) {
                 errors.merge(e.getErrors());
             }
@@ -92,85 +112,122 @@ final class Initializer {
      * instances are codependent (directly or transitively), ordering of injection is arbitrary.
      */
     void injectAll(final Errors errors) {
-        // loop over a defensive copy since ensureInjected() mutates the set. Unfortunately, that copy
-        // is made complicated by a bug in IBM's JDK, wherein entrySet().toArray(Object[]) doesn't work
-        for (InjectableReference<?> reference : Lists.newArrayList(pendingInjection.values())) {
+        Preconditions.checkState(validationStarted, "Validation should be done before injection");
+        for (InjectableReference<?> reference : pendingInjections) {
             try {
-                reference.get(errors);
-            } catch (ErrorsException e) {
-                errors.merge(e.getErrors());
+                reference.get();
+            } catch (InternalProvisionException ipe) {
+                errors.merge(ipe);
             }
         }
+        pendingInjections.clear();
+    }
 
-        if (!pendingInjection.isEmpty()) {
-            throw new AssertionError("Failed to satisfy " + pendingInjection);
+    private enum InjectableReferenceState {
+        NEW,
+        VALIDATED,
+        INJECTING,
+        READY
     }
 
-        ready.countDown();
-    }
+    private static class InjectableReference<T> implements Initializable<T> {
+        private volatile InjectableReferenceState state = InjectableReferenceState.NEW;
+        private volatile MembersInjectorImpl<T> membersInjector = null;
 
-    private class InjectableReference<T> implements Initializable<T> {
         private final InjectorImpl injector;
         private final T instance;
         private final Object source;
         private final Key<T> key;
         private final ProvisionListenerStackCallback<T> provisionCallback;
+        private final CycleDetectingLock<?> lock;
 
         public InjectableReference(InjectorImpl injector, T instance, Key<T> key,
-                                   ProvisionListenerStackCallback<T> provisionCallback, Object source) {
+                                   ProvisionListenerStackCallback<T> provisionCallback,
+                                   Object source,
+                                   CycleDetectingLock<?> lock) {
             this.injector = injector;
             this.key = key; // possibly null!
             this.provisionCallback = provisionCallback; // possibly null!
             this.instance = checkNotNull(instance, "instance");
             this.source = checkNotNull(source, "source");
+            this.lock = checkNotNull(lock, "lock");
         }
 
-        public MembersInjectorImpl<T> validate(Errors errors) throws ErrorsException {
+        public void validate(Errors errors) throws ErrorsException {
             @SuppressWarnings("unchecked") // the type of 'T' is a TypeLiteral<T>
             TypeLiteral<T> type = TypeLiteral.get((Class<T>) instance.getClass());
-            return injector.membersInjectorStore.get(type, errors.withSource(source));
+            membersInjector = injector.membersInjectorStore.get(type, errors.withSource(source));
+            Preconditions.checkNotNull(
+                    membersInjector,
+                    "No membersInjector available for instance: %s, from key: %s",
+                    instance,
+                    key);
+            state = InjectableReferenceState.VALIDATED;
         }
 
         /**
          * Reentrant. If {@code instance} was registered for injection at injector-creation time, this
          * method will ensure that all its members have been injected before returning.
          */
-        public T get(Errors errors) throws ErrorsException {
-            if (ready.getCount() == 0) {
+        @Override
+        public T get() throws InternalProvisionException {
+            // skipping acquiring lock if initialization is already finished
+            if (state == InjectableReferenceState.READY) {
                 return instance;
             }
+            // acquire lock for current binding to initialize an instance
+            Multimap<?, ?> lockCycle = lock.lockOrDetectPotentialLocksCycle();
+            if (!lockCycle.isEmpty()) {
+                // Potential deadlock detected and creation lock is not taken.
+                // According to injectAll()'s contract return non-initialized instance.
 
-            // just wait for everything to be injected by another thread
-            if (Thread.currentThread() != creatingThread) {
+                // This condition should not be possible under the current Guice implementation.
+                // This clause exists for defensive programming purposes.
+
+                // Reasoning:
+                // get() is called either directly from injectAll(), holds no locks and can not create
+                // a cycle, or it is called through a singleton scope, which resolves deadlocks by itself.
+                // Before calling get() object has to be requested for injection.
+                // Initializer.requestInjection() is called either for constant object bindings, which wrap
+                // creation into a Singleton scope, or from Binder.requestInjection(), which
+                // has to use Singleton scope to reuse the same InjectableReference to potentially
+                // create a lock cycle.
+                return instance;
+            }
             try {
-                    ready.await();
+                // lock acquired, current thread owns this instance initialization
+                switch (state) {
+                    case READY:
                         return instance;
-                } catch (InterruptedException e) {
-                    // Give up, since we don't know if our injection is ready
-                    throw new RuntimeException(e);
+                    // When instance depends on itself in the same thread potential dead lock
+                    // is not detected. We have to prevent a stack overflow and we use
+                    // an "injecting" stage to short-circuit a call.
+                    case INJECTING:
+                        return instance;
+                    case VALIDATED:
+                        state = InjectableReferenceState.INJECTING;
+                        break;
+                    case NEW:
+                        throw new IllegalStateException("InjectableReference is not validated yet");
+                    default:
+                        throw new IllegalStateException("Unknown state: " + state);
                 }
-            }
-
-            // toInject needs injection, do it right away. we only do this once, even if it fails
-            if (pendingInjection.remove(instance) != null) {
-                // safe because we only insert a members injector for the appropriate instance
-                @SuppressWarnings("unchecked")
-                MembersInjectorImpl<T> membersInjector =
-                        (MembersInjectorImpl<T>) pendingMembersInjectors.remove(instance);
-                Preconditions.checkState(membersInjector != null,
-                        "No membersInjector available for instance: %s, from key: %s", instance, key);
 
                 // if in Stage.TOOL, we only want to inject & notify toolable injection points.
                 // (otherwise we'll inject all of them)
-                membersInjector.injectAndNotify(instance,
-                        errors.withSource(source),
-                        key,
-                        provisionCallback,
-                        source,
-                        injector.options.stage == Stage.TOOL);
+                try {
+                    membersInjector.injectAndNotify(
+                            instance, key, provisionCallback, source, injector.options.stage == Stage.TOOL);
+                } catch (InternalProvisionException ipe) {
+                    throw ipe.addSource(source);
                 }
-
+                // mark instance as ready to skip a lock on subsequent calls
+                state = InjectableReferenceState.READY;
                 return instance;
+            } finally {
+                // always release our creation lock, even on failures
+                lock.unlock();
+            }
         }
 
         @Override

src/main/java/com/google/inject/internal/InjectionRequestProcessor.java

@@ -98,21 +98,19 @@ final class InjectionRequestProcessor extends AbstractProcessor {
         }
 
         void injectMembers() {
-            try {
-                injector.callInContext(new ContextualCallable<Void>() {
-                    public Void call(InternalContext context) {
+            try (InternalContext context = injector.enterContext()) {
+                boolean isStageTool = injector.options.stage == Stage.TOOL;
                 for (SingleMemberInjector memberInjector : memberInjectors) {
                     // Run injections if we're not in tool stage (ie, PRODUCTION or DEV),
                     // or if we are in tool stage and the injection point is toolable.
-                            if (injector.options.stage != Stage.TOOL || memberInjector.getInjectionPoint().isToolable()) {
-                                memberInjector.inject(errors, context, null);
+                    if (!isStageTool || memberInjector.getInjectionPoint().isToolable()) {
+                        try {
+                            memberInjector.inject(context, null);
+                        } catch (InternalProvisionException e) {
+                            errors.merge(e);
                         }
                     }
-                        return null;
                 }
-                });
-            } catch (ErrorsException e) {
-                throw new AssertionError();
             }
         }
     }

src/main/java/com/google/inject/internal/InjectorBindingData.java

@@ -0,0 +1,231 @@
+package com.google.inject.internal;
+
+import com.google.common.collect.ArrayListMultimap;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ListMultimap;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
+import com.google.inject.Binding;
+import com.google.inject.Key;
+import com.google.inject.Scope;
+import com.google.inject.TypeLiteral;
+import com.google.inject.spi.InjectionRequest;
+import com.google.inject.spi.MembersInjectorLookup;
+import com.google.inject.spi.ModuleAnnotatedMethodScannerBinding;
+import com.google.inject.spi.ProviderLookup;
+import com.google.inject.spi.ProvisionListenerBinding;
+import com.google.inject.spi.ScopeBinding;
+import com.google.inject.spi.StaticInjectionRequest;
+import com.google.inject.spi.TypeConverterBinding;
+import com.google.inject.spi.TypeListenerBinding;
+import java.lang.annotation.Annotation;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+
+/**
+ * A container that stores an injector's binding data. This excludes JIT binding data, which is
+ * stored in {@link InjectorJitBindingData}.
+ */
+class InjectorBindingData {
+
+    // The parent injector's InjectorBindingData, if the parent injector exists.
+    private final Optional<InjectorBindingData> parent;
+
+    // Must be a linked hashmap in order to preserve order of bindings in Modules.
+    private final Map<Key<?>, Binding<?>> explicitBindingsMutable = Maps.newLinkedHashMap();
+    private final Map<Key<?>, Binding<?>> explicitBindings =
+            Collections.unmodifiableMap(explicitBindingsMutable);
+    private final Map<Class<? extends Annotation>, ScopeBinding> scopes = Maps.newHashMap();
+    private final Set<ProviderLookup<?>> providerLookups = Sets.newLinkedHashSet();
+    private final Set<StaticInjectionRequest> staticInjectionRequests = Sets.newLinkedHashSet();
+    private final Set<MembersInjectorLookup<?>> membersInjectorLookups = Sets.newLinkedHashSet();
+    private final Set<InjectionRequest<?>> injectionRequests = Sets.newLinkedHashSet();
+    private final List<TypeConverterBinding> converters = Lists.newArrayList();
+    private final List<TypeListenerBinding> typeListenerBindings = Lists.newArrayList();
+    private final List<ProvisionListenerBinding> provisionListenerBindings = Lists.newArrayList();
+    private final List<ModuleAnnotatedMethodScannerBinding> scannerBindings = Lists.newArrayList();
+    // The injector's explicit bindings, indexed by the binding's type.
+    private final ListMultimap<TypeLiteral<?>, Binding<?>> indexedExplicitBindings =
+            ArrayListMultimap.create();
+
+    InjectorBindingData(Optional<InjectorBindingData> parent) {
+        this.parent = parent;
+    }
+
+    public Optional<InjectorBindingData> parent() {
+        return parent;
+    }
+
+    @SuppressWarnings("unchecked") // we only put in BindingImpls that match their key types
+    public <T> BindingImpl<T> getExplicitBinding(Key<T> key) {
+        Binding<?> binding = explicitBindings.get(key);
+        if (binding == null && parent.isPresent()) {
+            return parent.get().getExplicitBinding(key);
+        }
+        return (BindingImpl<T>) binding;
+    }
+
+    public Map<Key<?>, Binding<?>> getExplicitBindingsThisLevel() {
+        return explicitBindings;
+    }
+
+    public void putBinding(Key<?> key, BindingImpl<?> binding) {
+        explicitBindingsMutable.put(key, binding);
+    }
+
+    public void putProviderLookup(ProviderLookup<?> lookup) {
+        providerLookups.add(lookup);
+    }
+
+    public Set<ProviderLookup<?>> getProviderLookupsThisLevel() {
+        return providerLookups;
+    }
+
+    public void putStaticInjectionRequest(StaticInjectionRequest staticInjectionRequest) {
+        staticInjectionRequests.add(staticInjectionRequest);
+    }
+
+    public Set<StaticInjectionRequest> getStaticInjectionRequestsThisLevel() {
+        return staticInjectionRequests;
+    }
+
+    public void putInjectionRequest(InjectionRequest<?> injectionRequest) {
+        injectionRequests.add(injectionRequest);
+    }
+
+    public Set<InjectionRequest<?>> getInjectionRequestsThisLevel() {
+        return injectionRequests;
+    }
+
+    public void putMembersInjectorLookup(MembersInjectorLookup<?> membersInjectorLookup) {
+        membersInjectorLookups.add(membersInjectorLookup);
+    }
+
+    public Set<MembersInjectorLookup<?>> getMembersInjectorLookupsThisLevel() {
+        return membersInjectorLookups;
+    }
+
+    public ScopeBinding getScopeBinding(Class<? extends Annotation> annotationType) {
+        ScopeBinding scopeBinding = scopes.get(annotationType);
+        if (scopeBinding == null && parent.isPresent()) {
+            return parent.get().getScopeBinding(annotationType);
+        }
+        return scopeBinding;
+    }
+
+    public void putScopeBinding(Class<? extends Annotation> annotationType, ScopeBinding scope) {
+        scopes.put(annotationType, scope);
+    }
+
+    public Collection<ScopeBinding> getScopeBindingsThisLevel() {
+        return scopes.values();
+    }
+
+    public Iterable<TypeConverterBinding> getConvertersThisLevel() {
+        return converters;
+    }
+
+    public void addConverter(TypeConverterBinding typeConverterBinding) {
+        converters.add(typeConverterBinding);
+    }
+
+    public TypeConverterBinding getConverter(
+            String stringValue, TypeLiteral<?> type, Errors errors, Object source) {
+        TypeConverterBinding matchingConverter = null;
+        InjectorBindingData b = this;
+        while (b != null) {
+            for (TypeConverterBinding converter : b.getConvertersThisLevel()) {
+                if (converter.getTypeMatcher().matches(type)) {
+                    if (matchingConverter != null) {
+                        errors.ambiguousTypeConversion(stringValue, source, type, matchingConverter, converter);
+                    }
+                    matchingConverter = converter;
+                }
+            }
+            b = b.parent().orElse(null);
+        }
+        return matchingConverter;
+    }
+
+    public void addTypeListener(TypeListenerBinding listenerBinding) {
+        typeListenerBindings.add(listenerBinding);
+    }
+
+    public ImmutableList<TypeListenerBinding> getTypeListenerBindings() {
+        if (parent.isPresent()) {
+            return new ImmutableList.Builder<TypeListenerBinding>()
+                    .addAll(parent.get().getTypeListenerBindings())
+                    .addAll(typeListenerBindings)
+                    .build();
+        }
+        return ImmutableList.copyOf(typeListenerBindings);
+    }
+
+    public ImmutableList<TypeListenerBinding> getTypeListenerBindingsThisLevel() {
+        return ImmutableList.copyOf(typeListenerBindings);
+    }
+
+    public void addProvisionListener(ProvisionListenerBinding listenerBinding) {
+        provisionListenerBindings.add(listenerBinding);
+    }
+
+    public ImmutableList<ProvisionListenerBinding> getProvisionListenerBindings() {
+        if (parent.isPresent()) {
+            return new ImmutableList.Builder<ProvisionListenerBinding>()
+                    .addAll(parent.get().getProvisionListenerBindings())
+                    .addAll(provisionListenerBindings)
+                    .build();
+        }
+        return ImmutableList.copyOf(provisionListenerBindings);
+    }
+
+    public ImmutableList<ProvisionListenerBinding> getProvisionListenerBindingsThisLevel() {
+        return ImmutableList.copyOf(provisionListenerBindings);
+    }
+
+    public void addScanner(ModuleAnnotatedMethodScannerBinding scanner) {
+        scannerBindings.add(scanner);
+    }
+
+    public ImmutableList<ModuleAnnotatedMethodScannerBinding> getScannerBindings() {
+        if (parent.isPresent()) {
+            return new ImmutableList.Builder<ModuleAnnotatedMethodScannerBinding>()
+                    .addAll(parent.get().getScannerBindings())
+                    .addAll(scannerBindings)
+                    .build();
+        }
+        return ImmutableList.copyOf(scannerBindings);
+    }
+
+    public ImmutableList<ModuleAnnotatedMethodScannerBinding> getScannerBindingsThisLevel() {
+        return ImmutableList.copyOf(scannerBindings);
+    }
+
+    public Map<Class<? extends Annotation>, Scope> getScopes() {
+        ImmutableMap.Builder<Class<? extends Annotation>, Scope> builder = ImmutableMap.builder();
+        for (Map.Entry<Class<? extends Annotation>, ScopeBinding> entry : scopes.entrySet()) {
+            builder.put(entry.getKey(), entry.getValue().getScope());
+        }
+        return builder.build();
+    }
+
+    /**
+     * Once the injector's explicit bindings are finalized, this method is called to index all
+     * explicit bindings by their return type.
+     */
+    void indexBindingsByType() {
+        for (Binding<?> binding : getExplicitBindingsThisLevel().values()) {
+            indexedExplicitBindings.put(binding.getKey().getTypeLiteral(), binding);
+        }
+    }
+
+    public ListMultimap<TypeLiteral<?>, Binding<?>> getIndexedExplicitBindings() {
+        return indexedExplicitBindings;
+    }
+}

src/main/java/com/google/inject/internal/InjectorJitBindingData.java

@@ -0,0 +1,106 @@
+package com.google.inject.internal;
+
+import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
+import com.google.inject.Key;
+import java.util.Collections;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+
+/**
+ * A container for most just-in-time (JIT) binding data corresponding to an Injector. It
+ * includes @Inject constructor bindings. It does not include {@link MembersInjectorStore} or {@link
+ * ProvisionListenerCallbackStore}, which are still stored in {@link InjectorImpl}.
+ */
+final class InjectorJitBindingData {
+    /** Just-in-time binding cache. Guarded by {@link #lock}. */
+    private final Map<Key<?>, BindingImpl<?>> jitBindings = Maps.newHashMap();
+    /**
+     * Cache of Keys that we were unable to create JIT bindings for, so we don't keep trying. Guarded
+     * by {@link #lock}.
+     */
+    private final Set<Key<?>> failedJitBindings = Sets.newHashSet();
+
+    // The set of JIT binding keys that are banned for this particular injector, because a binding
+    // already exists in a child injector. Guarded by {@link #lock}.
+    private final WeakKeySet bannedKeys;
+
+    // The InjectorJitBindingData corresponding to the Injector's parent, if it exists.
+    private final Optional<InjectorJitBindingData> parent;
+
+    /**
+     * This lock is needed for threadsafe InjectorJitBindingData accesses. It corresponds to this
+     * InjectorJitBindingData's highest ancestor.
+     */
+    private final Object lock;
+
+    InjectorJitBindingData(Optional<InjectorJitBindingData> parent) {
+        this.parent = parent;
+        this.lock = parent.isPresent() ? parent.get().lock() : this;
+        this.bannedKeys = new WeakKeySet(lock);
+    }
+
+    Map<Key<?>, BindingImpl<?>> getJitBindings() {
+        return Collections.unmodifiableMap(jitBindings);
+    }
+
+    BindingImpl<?> getJitBinding(Key<?> key) {
+        return jitBindings.get(key);
+    }
+
+    void putJitBinding(Key<?> key, BindingImpl<?> binding) {
+        jitBindings.put(key, binding);
+    }
+
+    void removeJitBinding(Key<?> key) {
+        jitBindings.remove(key);
+    }
+
+    boolean isFailedJitBinding(Key<?> key) {
+        return failedJitBindings.contains(key);
+    }
+
+    void addFailedJitBinding(Key<?> key) {
+        failedJitBindings.add(key);
+    }
+
+    /**
+     * Forbids the corresponding injector and its ancestors from creating a binding to {@code key}.
+     * Child injectors ban their bound keys on their parent injectors to prevent just-in-time bindings
+     * on the parent injector that would conflict, and pass along their InjectorBindingData to control
+     * the banned key's lifetime.
+     */
+    void banKey(Key<?> key, InjectorBindingData injectorBindingData, Object source) {
+        banKeyInParent(key, injectorBindingData, source);
+        bannedKeys.add(key, injectorBindingData, source);
+    }
+
+    /**
+     * Similar to {@link #banKey(Key, InjectorBindingData, Object)} but we only begin banning the
+     * binding at the parent level. This is used to prevent JIT bindings in the parent injector from
+     * overriding explicit bindings declared in a child injector.
+     */
+    void banKeyInParent(Key<?> key, InjectorBindingData injectorBindingData, Object source) {
+        if (parent.isPresent()) {
+            parent.get().banKey(key, injectorBindingData, source);
+        }
+    }
+
+    /**
+     * Returns true if {@code key} is forbidden from being bound in the injector corresponding to this
+     * data object. This indicates that one of the injector's children has bound the key.
+     */
+    boolean isBannedKey(Key<?> key) {
+        return bannedKeys.contains(key);
+    }
+
+    /** Returns the source of a banned key. */
+    Set<Object> getSourcesForBannedKey(Key<?> key) {
+        return bannedKeys.getSources(key);
+    }
+
+    Object lock() {
+        return lock;
+    }
+}

src/main/java/com/google/inject/internal/InjectorShell.java

@@ -1,5 +1,9 @@
 package com.google.inject.internal;
 
+import static com.google.common.base.Preconditions.checkState;
+import static com.google.inject.Scopes.SINGLETON;
+import static com.google.inject.internal.GuiceInternal.GUICE_INTERNAL;
+
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Lists;
 import com.google.inject.Binder;
@@ -10,8 +14,9 @@ import com.google.inject.Provider;
 import com.google.inject.Singleton;
 import com.google.inject.Stage;
 import com.google.inject.internal.InjectorImpl.InjectorOptions;
+import com.google.inject.internal.util.ContinuousStopwatch;
 import com.google.inject.internal.util.SourceProvider;
-import com.google.inject.internal.util.Stopwatch;
+import com.google.inject.spi.BindingSourceRestriction;
 import com.google.inject.spi.Dependency;
 import com.google.inject.spi.Element;
 import com.google.inject.spi.Elements;
@@ -20,64 +25,34 @@ import com.google.inject.spi.ModuleAnnotatedMethodScannerBinding;
 import com.google.inject.spi.PrivateElements;
 import com.google.inject.spi.ProvisionListenerBinding;
 import com.google.inject.spi.TypeListenerBinding;
-
 import java.util.List;
-
-import static com.google.common.base.Preconditions.checkState;
-import static com.google.inject.Scopes.SINGLETON;
+import java.util.Optional;
+import java.util.logging.Logger;
 
 /**
- * A partially-initialized injector. See {@link InternalInjectorCreator}, which
- * uses this to build a tree of injectors in batch.
+ * InjectorShell is used by {@link InternalInjectorCreator} to recursively create a tree of
+ * uninitialized {@link Injector}s. Each InjectorShell corresponds to either the top-level root
+ * injector, or a private child injector.
+ *
+ * <p>The root InjectorShell extracts elements from its list of modules and processes these elements
+ * to aggregate data that is used to populate its injector's fields. Child injectors are constructed
+ * similarly, but using {@link PrivateElements} instead of modules.
+ *
+ * <p>It is necessary to create the root and child injectors in a single batch because there can be
+ * bidirectional parent <-> child injector dependencies that require the entire tree of injectors to
+ * be initialized together in the {@link InternalInjectorCreator}.
+ *
  */
 final class InjectorShell {
 
     private final List<Element> elements;
     private final InjectorImpl injector;
 
-    private InjectorShell(Builder builder, List<Element> elements, InjectorImpl injector) {
+    private InjectorShell(List<Element> elements, InjectorImpl injector) {
         this.elements = elements;
         this.injector = injector;
     }
 
-    /**
-     * The Injector is a special case because we allow both parent and child injectors to both have
-     * a binding for that key.
-     */
-    private static void bindInjector(InjectorImpl injector) {
-        Key<Injector> key = Key.get(Injector.class);
-        InjectorFactory injectorFactory = new InjectorFactory(injector);
-        injector.state.putBinding(key,
-                new ProviderInstanceBindingImpl<Injector>(injector, key, SourceProvider.UNKNOWN_SOURCE,
-                        injectorFactory, Scoping.UNSCOPED, injectorFactory,
-                        ImmutableSet.<InjectionPoint>of()));
-    }
-
-    /**
-     * The Logger is a special case because it knows the injection point of the injected member. It's
-     * the only binding that does this.
-     */
-    /*private static void bindLogger(InjectorImpl injector) {
-        Key<Logger> key = Key.get(Logger.class);
-        LoggerFactory loggerFactory = new LoggerFactory();
-        injector.state.putBinding(key,
-                new ProviderInstanceBindingImpl<Logger>(injector, key,
-                        SourceProvider.UNKNOWN_SOURCE, loggerFactory, Scoping.UNSCOPED,
-                        loggerFactory, ImmutableSet.<InjectionPoint>of()));
-    }*/
-
-    private static void bindStage(InjectorImpl injector, Stage stage) {
-        Key<Stage> key = Key.get(Stage.class);
-        InstanceBindingImpl<Stage> stageBinding = new InstanceBindingImpl<Stage>(
-                injector,
-                key,
-                SourceProvider.UNKNOWN_SOURCE,
-                new ConstantFactory<Stage>(Initializables.of(stage)),
-                ImmutableSet.<InjectionPoint>of(),
-                stage);
-        injector.state.putBinding(key, stageBinding);
-    }
-
     InjectorImpl getInjector() {
         return injector;
     }
@@ -90,18 +65,15 @@ final class InjectorShell {
         private final List<Element> elements = Lists.newArrayList();
         private final List<Module> modules = Lists.newArrayList();
 
-        /**
-         * lazily constructed
-         */
-        private State state;
+        // lazily constructed fields
+        private InjectorBindingData bindingData;
+        private InjectorJitBindingData jitBindingData;
 
         private InjectorImpl parent;
         private InjectorOptions options;
         private Stage stage;
 
-        /**
-         * null unless this exists in a {@link Binder#newPrivateBinder private environment}
-         */
+        /** null unless this exists in a {@link Binder#newPrivateBinder private environment} */
         private PrivateElementsImpl privateElements;
 
         Builder stage(Stage stage) {
@@ -111,7 +83,8 @@ final class InjectorShell {
 
         Builder parent(InjectorImpl parent) {
             this.parent = parent;
-            this.state = new InheritingState(parent.state);
+            this.jitBindingData = new InjectorJitBindingData(Optional.of(parent.getJitBindingData()));
+            this.bindingData = new InjectorBindingData(Optional.of(parent.getBindingData()));
             this.options = parent.options;
             this.stage = options.stage;
             return this;
@@ -124,22 +97,24 @@ final class InjectorShell {
         }
 
         void addModules(Iterable<? extends Module> modules) {
-            if (modules != null) {
             for (Module module : modules) {
                 this.modules.add(module);
             }
         }
-        }
 
         Stage getStage() {
             return options.stage;
         }
 
-        /**
-         * Synchronize on this before calling {@link #build}.
-         */
+        /** Synchronize on this before calling {@link #build}. */
         Object lock() {
-            return getState().lock();
+            // Lazily initializes bindingData and jitBindingData, if they were not already
+            // initialized with a parent injector by {@link #parent(InjectorImpl)}.
+            if (bindingData == null) {
+                jitBindingData = new InjectorJitBindingData(Optional.empty());
+                bindingData = new InjectorBindingData(Optional.empty());
+            }
+            return jitBindingData.lock();
         }
 
         /**
@@ -149,27 +124,38 @@ final class InjectorShell {
          */
         List<InjectorShell> build(
                 Initializer initializer,
-                ProcessedBindingData bindingData,
-                Stopwatch stopwatch,
+                ProcessedBindingData processedBindingData,
+                ContinuousStopwatch stopwatch,
                 Errors errors) {
             checkState(stage != null, "Stage not initialized");
             checkState(privateElements == null || parent != null, "PrivateElements with no parent");
-            checkState(state != null, "no state. Did you remember to lock() ?");
+            checkState(bindingData != null, "no binding data. Did you remember to lock() ?");
+            checkState(
+                    (privateElements == null && elements.isEmpty()) || modules.isEmpty(),
+                    "The shell is either built from modules (root) or from PrivateElements (children).");
 
             // bind Singleton if this is a top-level injector
             if (parent == null) {
                 modules.add(0, new RootModule());
             } else {
-                modules.add(0, new InheritedScannersModule(parent.state));
+                modules.add(0, new InheritedScannersModule(parent.getBindingData()));
             }
             elements.addAll(Elements.getElements(stage, modules));
 
+            // Check binding source restrictions only for the root shell (note that the root shell
+            // can have a parent Injector, when Injector.createChildInjector is called). It isn't
+            // necessary to call this check on child PrivateElements shells because it walks the entire
+            // tree of elements, recurring on PrivateElements.
+            if (privateElements == null) {
+                elements.addAll(BindingSourceRestriction.check(GUICE_INTERNAL, elements));
+            }
+
             // Look for injector-changing options
             InjectorOptionsProcessor optionsProcessor = new InjectorOptionsProcessor(errors);
             optionsProcessor.process(null, elements);
             options = optionsProcessor.getOptions(stage, options);
 
-            InjectorImpl injector = new InjectorImpl(parent, state, options);
+            InjectorImpl injector = new InjectorImpl(parent, bindingData, jitBindingData, options);
             if (privateElements != null) {
                 privateElements.initInjector(injector);
             }
@@ -184,10 +170,11 @@ final class InjectorShell {
             new MessageProcessor(errors).process(injector, elements);
 
             new ListenerBindingProcessor(errors).process(injector, elements);
-            List<TypeListenerBinding> typeListenerBindings = injector.state.getTypeListenerBindings();
+            List<TypeListenerBinding> typeListenerBindings =
+                    injector.getBindingData().getTypeListenerBindings();
             injector.membersInjectorStore = new MembersInjectorStore(injector, typeListenerBindings);
             List<ProvisionListenerBinding> provisionListenerBindings =
-                    injector.state.getProvisionListenerBindings();
+                    injector.getBindingData().getProvisionListenerBindings();
             injector.provisionListenerStore =
                     new ProvisionListenerCallbackStore(provisionListenerBindings);
             stopwatch.resetAndLog("TypeListeners & ProvisionListener creation");
@@ -200,38 +187,53 @@ final class InjectorShell {
 
             bindStage(injector, stage);
             bindInjector(injector);
-            //bindLogger(injector);
+            bindLogger(injector);
 
             // Process all normal bindings, then UntargettedBindings.
             // This is necessary because UntargettedBindings can create JIT bindings
             // and need all their other dependencies set up ahead of time.
-            new BindingProcessor(errors, initializer, bindingData).process(injector, elements);
-            new UntargettedBindingProcessor(errors, bindingData).process(injector, elements);
+            new BindingProcessor(errors, initializer, processedBindingData).process(injector, elements);
+            new UntargettedBindingProcessor(errors, processedBindingData).process(injector, elements);
             stopwatch.resetAndLog("Binding creation");
 
             new ModuleAnnotatedMethodScannerProcessor(errors).process(injector, elements);
             stopwatch.resetAndLog("Module annotated method scanners creation");
 
             List<InjectorShell> injectorShells = Lists.newArrayList();
-            injectorShells.add(new InjectorShell(this, elements, injector));
+            injectorShells.add(new InjectorShell(elements, injector));
 
             // recursively build child shells
             PrivateElementProcessor processor = new PrivateElementProcessor(errors);
             processor.process(injector, elements);
             for (Builder builder : processor.getInjectorShellBuilders()) {
-                injectorShells.addAll(builder.build(initializer, bindingData, stopwatch, errors));
+                injectorShells.addAll(builder.build(initializer, processedBindingData, stopwatch, errors));
             }
             stopwatch.resetAndLog("Private environment creation");
 
             return injectorShells;
         }
 
-        private State getState() {
-            if (state == null) {
-                state = new InheritingState(State.NONE);
-            }
-            return state;
     }
+
+    /**
+     * The Injector is a special case because we allow both parent and child injectors to both have a
+     * binding for that key.
+     */
+    private static void bindInjector(InjectorImpl injector) {
+        Key<Injector> key = Key.get(Injector.class);
+        InjectorFactory injectorFactory = new InjectorFactory(injector);
+        injector
+                .getBindingData()
+                .putBinding(
+                        key,
+                        new ProviderInstanceBindingImpl<Injector>(
+                                injector,
+                                key,
+                                SourceProvider.UNKNOWN_SOURCE,
+                                injectorFactory,
+                                Scoping.UNSCOPED,
+                                injectorFactory,
+                                ImmutableSet.<InjectionPoint>of()));
     }
 
     private static class InjectorFactory implements InternalFactory<Injector>, Provider<Injector> {
@@ -241,38 +243,78 @@ final class InjectorShell {
             this.injector = injector;
         }
 
-        public Injector get(Errors errors, InternalContext context, Dependency<?> dependency, boolean linked)
-                throws ErrorsException {
+        @Override
+        public Injector get(InternalContext context, Dependency<?> dependency, boolean linked) {
             return injector;
         }
 
+        @Override
         public Injector get() {
             return injector;
         }
 
+        @Override
         public String toString() {
             return "Provider<Injector>";
         }
     }
 
-    /*private static class LoggerFactory implements InternalFactory<Logger>, Provider<Logger> {
-        public Logger get(Errors errors, InternalContext context, Dependency<?> dependency, boolean linked) {
+    /**
+     * The Logger is a special case because it knows the injection point of the injected member. It's
+     * the only binding that does this.
+     */
+    private static void bindLogger(InjectorImpl injector) {
+        Key<Logger> key = Key.get(Logger.class);
+        LoggerFactory loggerFactory = new LoggerFactory();
+        injector
+                .getBindingData()
+                .putBinding(
+                        key,
+                        new ProviderInstanceBindingImpl<Logger>(
+                                injector,
+                                key,
+                                SourceProvider.UNKNOWN_SOURCE,
+                                loggerFactory,
+                                Scoping.UNSCOPED,
+                                loggerFactory,
+                                ImmutableSet.<InjectionPoint>of()));
+    }
+
+    private static class LoggerFactory implements InternalFactory<Logger>, Provider<Logger> {
+        @Override
+        public Logger get(InternalContext context, Dependency<?> dependency, boolean linked) {
             InjectionPoint injectionPoint = dependency.getInjectionPoint();
             return injectionPoint == null
                     ? Logger.getAnonymousLogger()
                     : Logger.getLogger(injectionPoint.getMember().getDeclaringClass().getName());
         }
 
+        @Override
         public Logger get() {
             return Logger.getAnonymousLogger();
         }
 
+        @Override
         public String toString() {
             return "Provider<Logger>";
         }
-    }*/
+    }
+
+    private static void bindStage(InjectorImpl injector, Stage stage) {
+        Key<Stage> key = Key.get(Stage.class);
+        InstanceBindingImpl<Stage> stageBinding =
+                new InstanceBindingImpl<Stage>(
+                        injector,
+                        key,
+                        SourceProvider.UNKNOWN_SOURCE,
+                        new ConstantFactory<Stage>(Initializables.of(stage)),
+                        ImmutableSet.<InjectionPoint>of(),
+                        stage);
+        injector.getBindingData().putBinding(key, stageBinding);
+    }
 
     private static class RootModule implements Module {
+        @Override
         public void configure(Binder binder) {
             binder = binder.withSource(SourceProvider.UNKNOWN_SOURCE);
             binder.bindScope(Singleton.class, SINGLETON);
@@ -281,14 +323,15 @@ final class InjectorShell {
     }
 
     private static class InheritedScannersModule implements Module {
-        private final State state;
+        private final InjectorBindingData bindingData;
 
-        InheritedScannersModule(State state) {
-            this.state = state;
+        InheritedScannersModule(InjectorBindingData bindingData) {
+            this.bindingData = bindingData;
         }
 
+        @Override
         public void configure(Binder binder) {
-            for (ModuleAnnotatedMethodScannerBinding binding : state.getScannerBindings()) {
+            for (ModuleAnnotatedMethodScannerBinding binding : bindingData.getScannerBindings()) {
                 binding.applyTo(binder);
             }
         }

src/main/java/com/google/inject/internal/InstanceBindingImpl.java

@@ -5,20 +5,17 @@ import com.google.common.base.Objects;
 import com.google.common.collect.ImmutableSet;
 import com.google.inject.Binder;
 import com.google.inject.Key;
-import com.google.inject.Provider;
 import com.google.inject.spi.BindingTargetVisitor;
 import com.google.inject.spi.Dependency;
 import com.google.inject.spi.HasDependencies;
 import com.google.inject.spi.InjectionPoint;
 import com.google.inject.spi.InstanceBinding;
-import com.google.inject.util.Providers;
 
 import java.util.Set;
 
 final class InstanceBindingImpl<T> extends BindingImpl<T> implements InstanceBinding<T> {
 
     final T instance;
-    final Provider<T> provider;
     final ImmutableSet<InjectionPoint> injectionPoints;
 
     public InstanceBindingImpl(InjectorImpl injector, Key<T> key, Object source,
@@ -27,7 +24,6 @@ final class InstanceBindingImpl<T> extends BindingImpl<T> implements InstanceBin
         super(injector, key, source, internalFactory, Scoping.EAGER_SINGLETON);
         this.injectionPoints = ImmutableSet.copyOf(injectionPoints);
         this.instance = instance;
-        this.provider = Providers.of(instance);
     }
 
     public InstanceBindingImpl(Object source, Key<T> key, Scoping scoping,
@@ -35,40 +31,41 @@ final class InstanceBindingImpl<T> extends BindingImpl<T> implements InstanceBin
         super(source, key, scoping);
         this.injectionPoints = ImmutableSet.copyOf(injectionPoints);
         this.instance = instance;
-        this.provider = Providers.of(instance);
     }
 
     @Override
-    public Provider<T> getProvider() {
-        return this.provider;
-    }
-
     public <V> V acceptTargetVisitor(BindingTargetVisitor<? super T, V> visitor) {
         return visitor.visit(this);
     }
 
+    @Override
     public T getInstance() {
         return instance;
     }
 
+    @Override
     public Set<InjectionPoint> getInjectionPoints() {
         return injectionPoints;
     }
 
+    @Override
     public Set<Dependency<?>> getDependencies() {
         return instance instanceof HasDependencies
                 ? ImmutableSet.copyOf(((HasDependencies) instance).getDependencies())
                 : Dependency.forInjectionPoints(injectionPoints);
     }
 
+    @Override
     public BindingImpl<T> withScoping(Scoping scoping) {
         return new InstanceBindingImpl<T>(getSource(), getKey(), scoping, injectionPoints, instance);
     }
 
+    @Override
     public BindingImpl<T> withKey(Key<T> key) {
         return new InstanceBindingImpl<T>(getSource(), key, getScoping(), injectionPoints, instance);
     }
 
+    @Override
     public void applyTo(Binder binder) {
         // instance bindings aren't scoped
         binder.withSource(getSource()).bind(getKey()).toInstance(instance);