Add TeamCity workflows & checks and backports some gradle stuff from 1.18.x branch (#9841)

Co-authored-by: embeddedt <[email protected]>

.gitattributes

@@ -14,3 +14,10 @@
 *.cfg text eol=lf
 *.py text eol=lf
 *.jks binary
+
+# Disable autocrlf on generated files, they always generate with LF
+src/generated/**/.cache/cache text eol=lf
+src/generated/**/*.json text eol=lf
+src/generated_test/**/.cache/cache text eol=lf
+src/generated_test/**/*.json text eol=lf
+

.gitignore

@@ -9,36 +9,38 @@
 
 #idea
 /.idea
+/*/out
 /classes
 *.iml
 
 #gradle
 /build
 /.gradle
-/mdk/.gradle
-/mdk/build
+/*/build
+/*/.gradle
 
-#occupational hazards
+# Projects repo, either ignore it, or ignore patches.
 /projects/mcp/
 /projects/clean/
 /projects/forge/
+/projects/fmlonly/
+#/patches/
+
+#occupational hazards
 /projects/**/build/
 /projects/**/out/
 /projects/**/run/
 /projects/**/*.launch
 /repo/
-/buildSrc
 src/generated/resources/.cache/
 
 #Patch rejects
 /patches-/
-*.patch.rej
+#*.patch.rej
+/projects/*/rejects/
 
 # FML changelog
 changelog.txt
 *.py
 *.7z
 /logs/
-
-gradle.properties
-!/mdk/gradle.properties

.teamcity/settings.kts

@@ -0,0 +1,185 @@
+import jetbrains.buildServer.configs.kotlin.v2019_2.*
+import jetbrains.buildServer.configs.kotlin.v2019_2.projectFeatures.githubIssues
+import jetbrains.buildServer.configs.kotlin.*
+import jetbrains.buildServer.configs.kotlin.v2019_2.buildSteps.gradle
+
+/*
+The settings script is an entry point for defining a TeamCity
+project hierarchy. The script should contain a single call to the
+project() function with a Project instance or an init function as
+an argument.
+
+VcsRoots, BuildTypes, Templates, and subprojects can be
+registered inside the project using the vcsRoot(), buildType(),
+template(), and subProject() methods respectively.
+
+To debug settings scripts in command-line, run the
+
+    mvnDebug org.jetbrains.teamcity:teamcity-configs-maven-plugin:generate
+
+command and attach your debugger to the port 8000.
+
+To debug in IntelliJ Idea, open the 'Maven Projects' tool window (View
+-> Tool Windows -> Maven Projects), find the generate task node
+(Plugins -> teamcity-configs -> teamcity-configs:generate), the
+'Debug' option is available in the context menu for the task.
+*/
+
+version = "2021.2"
+
+project {
+
+    buildType(Build)
+    buildType(BuildSecondaryBranches)
+    buildType(PullRequests)
+    buildType(PullRequestChecks)
+    buildType(PullRequestCompatibility)
+
+    params {
+        text("docker_jdk_version", "17", label = "Gradle version", description = "The version of the JDK to use during execution of tasks in a JDK.", display = ParameterDisplay.HIDDEN, allowEmpty = false)
+        text("docker_gradle_version", "7.3.3", label = "Gradle version", description = "The version of Gradle to use during execution of Gradle tasks.", display = ParameterDisplay.HIDDEN, allowEmpty = false)
+        text("git_main_branch", "1.20.x", label = "Git Main Branch", description = "The git main or default branch to use in VCS operations.", display = ParameterDisplay.HIDDEN, allowEmpty = false)
+        text("git_branch_spec", """
+                +:refs/heads/(main*)
+                +:refs/heads/(master*)
+                +:refs/heads/(develop|release|staging|main|master)
+                +:refs/heads/(1.*)
+            """.trimIndent(), label = "The branch specification of the repository", description = "By default all main branches are build by the configuration. Modify this value to adapt the branches build.", display = ParameterDisplay.HIDDEN, allowEmpty = true)
+        text("github_repository_name", "MinecraftForge", label = "The github repository name. Used to connect to it in VCS Roots.", description = "This is the repository slug on github. So for example `MinecraftForge` or `MinecraftForge`. It is interpolated into the global VCS Roots.", display = ParameterDisplay.HIDDEN, allowEmpty = false)
+        text("env.PUBLISHED_JAVA_ARTIFACT_ID", "forge", label = "Published artifact id", description = "The maven coordinate artifact id that has been published by this build. Can not be empty.", allowEmpty = false)
+        text("env.PUBLISHED_JAVA_GROUP", "net.minecraftforge", label = "Published group", description = "The maven coordinate group that has been published by this build. Can not be empty.", allowEmpty = false)
+        //These are references and not actually keys
+        password("env.CROWDIN_KEY", "credentialsJSON:a3102dbe-805d-4177-9f54-3d2c2eb08fd5", display = ParameterDisplay.HIDDEN)
+        password("env.LEGACY_KEYSTORE_URL", "credentialsJSON:a2d2efc7-4492-47b6-9826-d14b2c1243a0", display = ParameterDisplay.HIDDEN)
+        password("env.LEGACY_KEYSTORE_PASSWORD", "credentialsJSON:9f9a1a9e-f91b-40d5-b888-8ebc79a99ded", display = ParameterDisplay.HIDDEN)
+        text("additional_publishing_gradle_parameters", "-PcrowdinKey=%env.CROWDIN_KEY% -PkeystoreKeyPass=%env.LEGACY_KEYSTORE_PASSWORD% -PkeystoreStorePass=%env.LEGACY_KEYSTORE_PASSWORD% -Pkeystore=%env.LEGACY_KEYSTORE_URL%", label = "Additional gradle parameters for publish", description = "Contains the additional gradle parameters used during publishing.", display = ParameterDisplay.HIDDEN, allowEmpty = true)
+
+        checkbox("should_execute_build", "false", label = "Should build", description = "Indicates if the build task should be executed.", display = ParameterDisplay.HIDDEN,
+            checked = "true", unchecked = "false")
+        checkbox("should_execute_test", "false", label = "Should build", description = "Indicates if the build task should be executed.", display = ParameterDisplay.HIDDEN,
+            checked = "true", unchecked = "false")
+    }
+
+    features {
+        githubIssues {
+            id = "MinecraftForge_MinecraftForge__IssueTracker"
+            displayName = "MinecraftForge/MinecraftForge"
+            repositoryURL = "https://github.com/MinecraftForge/MinecraftForge"
+        }
+    }
+}
+
+object Build : BuildType({
+    templates(AbsoluteId("MinecraftForge_SetupGradleUtilsCiEnvironmen"), AbsoluteId("MinecraftForge_BuildWithDiscordNotifications"), AbsoluteId("MinecraftForge_BuildMainBranches"), AbsoluteId("MinecraftForge_SetupProjectUsingGradle"), AbsoluteId("MinecraftForge_BuildUsingGradle"), AbsoluteId("MinecraftForge_PublishProjectUsingGradle"), AbsoluteId("MinecraftForge_TriggersStaticFilesWebpageGenerator"))
+    id("MinecraftForge_MinecraftForge__Build")
+    name = "Build"
+    description = "Builds and Publishes the main branches of the project."
+})
+
+object BuildSecondaryBranches : BuildType({
+    templates(AbsoluteId("MinecraftForge_ExcludesBuildingDefaultBranch"), AbsoluteId("MinecraftForge_SetupGradleUtilsCiEnvironmen"), AbsoluteId("MinecraftForge_BuildWithDiscordNotifications"), AbsoluteId("MinecraftForge_BuildMainBranches"), AbsoluteId("MinecraftForge_SetupProjectUsingGradle"), AbsoluteId("MinecraftForge_BuildUsingGradle"))
+    id("MinecraftForge_MinecraftForge__BuildSecondaryBranches")
+    name = "Build - Secondary Branches"
+    description = "Builds and Publishes the secondary branches of the project."
+    params {
+        text("git_branch_spec", """
+                +:refs/heads/(*)
+                -:refs/heads/noci*
+            """.trimIndent(), label = "The branch specification of the repository", description = "By default all main branches are build by the configuration. Modify this value to adapt the branches build.", display = ParameterDisplay.HIDDEN, allowEmpty = true)
+    }
+    vcs {
+        branchFilter = """
+            +:*
+            -:1.*
+            -:<default>
+        """.trimIndent()
+    }
+})
+
+object PullRequests : BuildType({
+    templates(AbsoluteId("MinecraftForge_BuildPullRequests"), AbsoluteId("MinecraftForge_SetupGradleUtilsCiEnvironmen"), AbsoluteId("MinecraftForge_BuildWithDiscordNotifications"), AbsoluteId("MinecraftForge_SetupProjectUsingGradle"), AbsoluteId("MinecraftForge_BuildUsingGradle"))
+    id("MinecraftForge_MinecraftForge__PullRequests")
+    name = "Pull Requests"
+    description = "Builds pull requests for the project"
+
+    params {
+        checkbox("should_execute_build", "true", label = "Should build", description = "Indicates if the build task should be executed.", display = ParameterDisplay.HIDDEN,
+            checked = "true", unchecked = "false")
+        text(
+            "gradle_build_task",
+            "assemble",
+            label = "Gradle build task to execute during build",
+            description = "Determines the build task that is executed to build the project.",
+            display = ParameterDisplay.HIDDEN,
+            allowEmpty = false
+        )
+    }
+})
+
+object PullRequestChecks : BuildType({
+    templates(AbsoluteId("MinecraftForge_BuildPullRequests"), AbsoluteId("MinecraftForge_SetupGradleUtilsCiEnvironmen"), AbsoluteId("MinecraftForge_BuildWithDiscordNotifications"), AbsoluteId("MinecraftForge_SetupProjectUsingGradle"))
+    id("MinecraftForge_MinecraftForge__PullRequestChecks")
+    name = "Pull Requests (Checks)"
+    description = "Checks pull requests for the project"
+
+    steps {
+        gradle {
+            name = "Check"
+            id = "RUNNER_10_Check"
+
+            tasks = "checkAll"
+            gradleParams = "--continue %gradle_custom_args%"
+            enableStacktrace = true
+            dockerImage = "%docker_gradle_image%"
+            dockerRunParameters = """
+                -v "/opt/cache/agent/gradle:/home/gradle/.gradle" 
+                -v "/opt/cache/shared/gradle:/home/gradle/rocache:ro"
+                --network=host
+                -u 1000:1000
+                %docker_additional_args%
+            """.trimIndent()
+        }
+    }
+
+    vcs {
+        branchFilter = """
+            +:*
+            -:1.*
+            -:<default>
+        """.trimIndent()
+    }
+})
+
+object PullRequestCompatibility : BuildType({
+    templates(AbsoluteId("MinecraftForge_BuildPullRequests"), AbsoluteId("MinecraftForge_SetupGradleUtilsCiEnvironmen"), AbsoluteId("MinecraftForge_BuildWithDiscordNotifications"), AbsoluteId("MinecraftForge_SetupProjectUsingGradle"))
+    id("MinecraftForge_MinecraftForge__PullRequestCompatibility")
+    name = "Pull Requests (Compatibility)"
+    description = "Validates binary compatibility for pull requests made to the project"
+
+    steps {
+        gradle {
+            name = "Validate"
+            id = "RUNNER_10_Compatibility"
+
+            tasks = "checkJarCompatibility"
+            gradleParams = "--continue %gradle_custom_args%"
+            enableStacktrace = true
+            dockerImage = "%docker_gradle_image%"
+            dockerRunParameters = """
+                -v "/opt/cache/agent/gradle:/home/gradle/.gradle" 
+                -v "/opt/cache/shared/gradle:/home/gradle/rocache:ro"
+                --network=host
+                -u 1000:1000
+                %docker_additional_args%
+            """.trimIndent()
+        }
+    }
+
+    vcs {
+        branchFilter = """
+            +:*
+            -:1.*
+            -:<default>
+        """.trimIndent()
+    }
+})

.travis.yml

@@ -1,39 +0,0 @@
-sudo: required
-dist: trusty
-
-language: java
-jdk: oraclejdk8
-
-env:
-  - BUILD_NUMBER=9999
-
-before_cache:
-  - rm -f  $HOME/.gradle/caches/modules-2/modules-2.lock
-  - rm -fr $HOME/.gradle/caches/*/plugin-resolution/
-  - rm -f  $HOME/.gradle/caches/minecraft/deobfedDeps/providedDummy.jar
-  - rm -f  $HOME/.gradle/caches/minecraft/deobfedDeps/compileDummy.jar
-cache:
-  directories:
-    - $HOME/.gradle/caches/
-    - $HOME/.gradle/wrapper/
-    - $TRAVIS_BUILD_DIR/build/localCache/Forge/
-
-before_install: chmod +x gradlew
-install:
-  - ./gradlew --refresh-dependencies
-  - ./gradlew ciWriteBuildNumber
-script:
-  - travis_wait ./gradlew build -x createExe -S
-  - ./gradlew -p projects/Forge test -S -i
-
-notifications:
-  email: false
-
-# skip building travis on 1.13+ - it doesn't work there
-branches:
-  except:
-    - 1.13-pre
-    - 1.13.x
-    - 1.14.x
-    - 1.15.x
-    - /^noci-.*$/

Jenkinsfile

@@ -6,8 +6,8 @@ pipeline {
     }
     agent {
         docker {
-            image 'gradle:jdk8'
-            args '-v forgegc:/home/gradle/.gradle/'
+            image 'gradle:7-jdk16'
+            //args '-v forgegc:/home/gradle/.gradle_cache/'
         }
     }
     environment {
@@ -34,11 +34,23 @@ pipeline {
                 )
             }
         }
+        /*
+        stage('pull_cache') {
+            steps {
+                sh 'cp -r /home/gradle/.gradle_cache/jdks/ /home/gradle/.gradle/jdks/'
+                sh 'cp -r /home/gradle/.gradle_cache/wrapper/ /home/gradle/.gradle/wrapper/'
+                sh 'cp -r /home/gradle/.gradle_cache/caches/ /home/gradle/.gradle/caches/'
+            }
+        }
+        */
         stage('setup') {
             steps {
-                sh './gradlew ${GRADLE_ARGS} --refresh-dependencies --continue setup'
+                withGradle {
+                    sh './gradlew ${GRADLE_ARGS} --refresh-dependencies --continue setup'
+                }
                 script {
-                    env.MYVERSION = sh(returnStdout: true, script: './gradlew :forge:properties -q | grep "version:" | awk \'{print $2}\'').trim()
+                    env.MYVERSION = sh(returnStdout: true, script: './gradlew :forge:properties -q | grep "^version:" | cut -d" " -f2').trim()
+                    env.FMLONLY_VERSION = sh(returnStdout: true, script: './gradlew :fmlonly:properties -q | grep "^version:" | cut -d" " -f2').trim()
                 }
             }
         }
@@ -59,15 +71,23 @@ pipeline {
                 }
             }
             environment {
-                FORGE_MAVEN = credentials('forge-maven-forge-user')
                 CROWDIN = credentials('forge-crowdin')
                 KEYSTORE = credentials('forge-jenkins-keystore-old')
                 KEYSTORE_KEYPASS = credentials('forge-jenkins-keystore-old-keypass')
                 KEYSTORE_STOREPASS = credentials('forge-jenkins-keystore-old-keypass')
             }
             steps {
-                sh './gradlew ${GRADLE_ARGS} :forge:publish -PforgeMavenUser=${FORGE_MAVEN_USR} -PforgeMavenPassword=${FORGE_MAVEN_PSW} -PkeystoreKeyPass=${KEYSTORE_KEYPASS} -PkeystoreStorePass=${KEYSTORE_STOREPASS} -Pkeystore=${KEYSTORE} -PcrowdinKey=${CROWDIN}'
-                sh 'curl --user ${FORGE_MAVEN} http://files.minecraftforge.net/maven/manage/promote/latest/net.minecraftforge.forge/${MYVERSION}'
+                withCredentials([usernamePassword(credentialsId: 'maven-forge-user', usernameVariable: 'MAVEN_USER', passwordVariable: 'MAVEN_PASSWORD')]) {
+                    withGradle {
+                        sh './gradlew ${GRADLE_ARGS} publish -PkeystoreKeyPass=${KEYSTORE_KEYPASS} -PkeystoreStorePass=${KEYSTORE_STOREPASS} -Pkeystore=${KEYSTORE} -PcrowdinKey=${CROWDIN}'
+                    }
+                }
+            }
+            post {
+                success {
+                    build job: 'filegenerator', parameters: [string(name: 'COMMAND', value: "promote net.minecraftforge:forge ${env.MYVERSION} latest")], propagate: false, wait: false
+                    build job: 'filegenerator', parameters: [string(name: 'COMMAND', value: "promote net.minecraftforge:fmlonly ${env.FMLONLY_VERSION} latest")], propagate: false, wait: false
+                }
             }
         }
         stage('test_publish_pr') { //Publish to local repo to test full process, but don't include credentials so it can't sign/publish to maven
@@ -78,7 +98,9 @@ pipeline {
                 CROWDIN = credentials('forge-crowdin')
             }
             steps {
-                sh './gradlew ${GRADLE_ARGS} :forge:publish -PcrowdinKey=${CROWDIN}'
+                withGradle {
+                    sh './gradlew ${GRADLE_ARGS} publish -PcrowdinKey=${CROWDIN}'
+                }
             }
         }
     }

LICENSE-header.txt

@@ -1,16 +1,2 @@
-Minecraft Forge
-Copyright (c) 2016-2019.
-
-This library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Lesser General Public
-License as published by the Free Software Foundation version 2.1
-of the License.
-
-This library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Lesser General Public License for more details.
-
-You should have received a copy of the GNU Lesser General Public
-License along with this library; if not, write to the Free Software
-Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+Copyright (c) Forge Development LLC and contributors
+SPDX-License-Identifier: LGPL-2.1-only

buildSrc/.gitignore

@@ -0,0 +1,3 @@
+/.gradle/
+/build/
+/out/

buildSrc/build.gradle

@@ -0,0 +1,11 @@
+repositories {
+    maven { url = 'https://maven.minecraftforge.net/' }
+	mavenCentral()
+}
+dependencies {
+	implementation 'org.ow2.asm:asm:9.1'
+	implementation 'org.ow2.asm:asm-tree:9.1'
+    implementation 'net.minecraftforge:srgutils:0.4.+'
+	implementation 'commons-io:commons-io:2.8.0'
+	implementation 'com.google.code.gson:gson:2.10'
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/BytecodeFinder.groovy

@@ -0,0 +1,64 @@
+package net.minecraftforge.forge.tasks
+
+import groovy.json.JsonBuilder
+import org.gradle.api.DefaultTask
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.tasks.InputFile
+import org.gradle.api.tasks.OutputFile
+import org.gradle.api.tasks.TaskAction
+import org.objectweb.asm.ClassReader
+import org.objectweb.asm.Opcodes
+import org.objectweb.asm.tree.ClassNode
+import org.objectweb.asm.tree.FieldNode
+import org.objectweb.asm.tree.MethodNode
+
+import java.util.zip.ZipEntry
+import java.util.zip.ZipInputStream
+
+abstract class BytecodeFinder extends DefaultTask {
+    @InputFile abstract RegularFileProperty getJar()
+    @OutputFile abstract RegularFileProperty getOutput()
+
+    BytecodeFinder() {
+        output.convention(project.layout.buildDirectory.dir(name).map { it.file("output.json") })
+    }
+
+    @TaskAction
+    protected void exec() {
+        Util.init()
+
+        def outputFile = output.get().asFile
+        if (outputFile.exists())
+            outputFile.delete()
+
+        pre()
+
+        jar.get().asFile.withInputStream { i ->
+            new ZipInputStream(i).withCloseable { zin ->
+                ZipEntry zein
+                while ((zein = zin.nextEntry) != null) {
+                    if (zein.name.endsWith('.class')) {
+                        def node = new ClassNode(Opcodes.ASM9)
+                        new ClassReader(zin).accept(node, 0)
+                        process(node)
+                    }
+                }
+            }
+        }
+
+        post()
+        outputFile.text = new JsonBuilder(getData()).toPrettyString()
+    }
+
+
+    protected process(ClassNode node) {
+        if (node.fields != null) node.fields.each { process(node, it) }
+        if (node.methods != null) node.methods.each { process(node, it) }
+    }
+
+    protected pre() {}
+    protected process(ClassNode parent, FieldNode node) {}
+    protected process(ClassNode parent, MethodNode node) {}
+    protected post() {}
+    protected abstract Object getData()
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/CheckATs.groovy

@@ -0,0 +1,267 @@
+package net.minecraftforge.forge.tasks
+
+import net.minecraftforge.srgutils.IMappingFile
+import org.gradle.api.file.ConfigurableFileCollection
+import org.gradle.api.file.RegularFileProperty
+
+import org.gradle.api.DefaultTask
+import org.gradle.api.tasks.InputFile
+import org.gradle.api.tasks.InputFiles
+import org.gradle.api.tasks.Optional
+import org.gradle.api.tasks.TaskAction
+import org.objectweb.asm.Opcodes
+
+abstract class CheckATs extends DefaultTask {
+	@InputFile abstract RegularFileProperty getInheritance()
+	@InputFiles abstract ConfigurableFileCollection getAts()
+    @InputFile @Optional abstract RegularFileProperty getMappings()
+	
+    @TaskAction
+    protected void exec() {
+        def mappings = mappings.map { IMappingFile.load(it.asFile) }.getOrNull()
+		Util.init()
+		def parse = { line ->
+			def idx = line.indexOf('#')
+			def comment = idx == -1 ? null : line.substring(idx)
+			if (idx != -1) line = line.substring(0, idx - 1)
+			def (modifier, cls, desc) = (line.trim() + '     ').split(' ', -1)
+			def key = cls + (desc.isEmpty() ? '' : ' ' + desc)
+			return [modifier, cls, desc, comment, key]
+		}
+		def accessLevel = { access ->
+			if ((access & Opcodes.ACC_PUBLIC)    != 0) return 3
+			if ((access & Opcodes.ACC_PROTECTED) != 0) return 2
+			if ((access & Opcodes.ACC_PRIVATE)   != 0) return 0
+			return 1
+		}
+		def accessStr = { access ->
+			if (access.endsWith('-f') || access.endsWith('+f'))
+				return 4
+			switch (access.toLowerCase()) {
+				case 'public':    return 3
+				case 'protected': return 2
+				case 'default':   return 1
+				case 'private':   return 0
+				default:          return -1
+			}
+		}
+		def json = inheritance.get().asFile.json()
+		
+		ats.each { f -> 
+			TreeMap lines = [:]
+			def group = null
+			for (def line : f.readLines()) {
+				if (line.isEmpty()) continue
+				if (line.startsWith('#group ')) {
+					def (modifier, cls, desc, comment, key) = parse.call(line.substring(7))
+					
+					if (desc != '*' && desc != '*()' && desc != '<init>')
+						throw new IllegalStateException('Invalid group: ' + line)
+					
+					group = [modifier: modifier, cls: cls, desc: desc, comment: comment, 
+						existing: [] as Set,
+						children: [] as TreeSet,
+						group: true
+					]
+					if (lines.containsKey(key))
+						throw new IllegalStateException('Duplicate group: ' + line)
+					
+					lines[key] = group
+				} else if (group != null) {
+					if (line.startsWith('#endgroup')) {
+						group = null
+					} else {
+						def (modifier, cls, desc, comment, key) = parse.call(line)
+						group['existing'].add(key)
+					}
+				} else if (line.startsWith('#endgroup')) {
+					throw new IllegalStateException('Invalid group ending: ' + line)
+				} else if (line.startsWith('#')) {
+					//Nom
+				} else {
+					def (modifier, cls, desc, comment, key) = parse.call(line)
+					if (lines.containsKey(key)) {
+						println('Duplicate: ' + line)
+						continue
+					}
+					lines[key] = [modifier: modifier, cls: cls, desc: desc, comment: comment, group: false]
+				}
+			}
+			
+			// Process Groups, this will remove any entries outside the group that is covered by the group
+			for (def key : new ArrayList<>(lines.keySet())) {
+				def entry = lines.get(key)
+				if (entry != null && entry['group']) {
+					def cls = entry['cls']
+					def jcls = json.get(cls.replaceAll('\\.', '/'))
+					if (jcls == null) {
+						lines.remove(key)
+						println('Invalid Group: ' + key)
+					} else if ('*' == entry['desc']) {
+						if (!jcls.containsKey('fields')) {
+							lines.remove(key)
+							println('Invalid Group, Class has no fields: ' + key)
+						} else {
+							jcls['fields'].each { field, value ->
+								def fkey = cls + ' ' + field
+								if (accessLevel.call(value['access']) < accessStr.call(entry['modifier'])) {
+									if (lines.containsKey(fkey)) {
+										lines.remove(fkey)
+									} else if (!entry['existing'].contains(fkey)) {
+										println('Added: ' + fkey)
+									}
+									entry['children'].add(fkey)
+								} else if (lines.containsKey(fkey)) {
+									lines.remove(fkey)
+									println('Removed: ' + fkey)
+								}
+							}
+							entry['existing'].stream().findAll{ !entry['children'].contains(it) }.each{ println('Removed: ' + it) }
+						}
+					} else if ('*()' == entry['desc']) {
+						if (!jcls.containsKey('methods')) {
+							lines.remove(key)
+							println('Invalid Group, Class has no methods: ' + key)
+						} else {
+							jcls['methods'].each{ mtd, value ->
+								if (mtd.startsWith('<clinit>') || mtd.startsWith('lambda$'))
+									return
+								key = cls + ' ' + mtd.replace(' ', '')
+								if (accessLevel.call(value['access']) < accessStr.call(entry['modifier'])) {
+									if (lines.containsKey(key)) {
+										lines.remove(key)
+									} else if (!entry['existing'].contains(key)) {
+										println('Added: ' + key)
+									}
+									entry['children'].add(key)
+								} else if (lines.containsKey(key)) {
+									lines.remove(key)
+									println('Removed: ' + key)
+								}
+							}
+							entry['existing'].stream().findAll{ !entry['children'].contains(it) }.each{ println('Removed: ' + it) }
+						}
+					} else if ('<init>' == entry['desc']) { //Make all public non-abstract subclasses
+						json.each{ tcls,value -> 
+							if (!value.containsKey('methods') || ((value['access'] & Opcodes.ACC_ABSTRACT) != 0))
+								return
+							def parents = [] as Set
+							def parent = tcls
+							while (parent != null && json.containsKey(parent)) {
+								parents.add(parent)
+								def p = json[parent]
+								parent = p == null ? null : p['superName']
+							}
+							if (parents.contains(cls.replaceAll('\\.', '/'))) {
+								value['methods'].each{ mtd, v -> 
+									if (mtd.startsWith('<init>')) {
+										def child = tcls.replaceAll('/', '\\.') + ' ' + mtd.replace(' ', '')
+										if (accessLevel.call(v['access']) < 3) {
+											if (lines.containsKey(child)) {
+												lines.remove(child)
+											} else if (!entry['existing'].contains(child)) {
+												println('Added: ' + child)
+											}
+											entry['children'].add(child)
+										} else if (lines.containsKey(child)) {
+											lines.remove(child)
+											println('Removed: ' + child)
+										}
+									}
+								}
+							}
+						}
+						entry['existing'].stream().findAll{ !entry['children'].contains(it) }.each{ println('Removed: ' + it) }
+					}
+				}
+			}
+			
+			// Process normal lines, remove invalid and remove narrowing
+			for (def key : new ArrayList<>(lines.keySet())) {
+				def entry = lines.get(key)
+				if (entry != null && !entry['group']) {
+					def cls = entry['cls']
+					def jcls = json.get(cls.replaceAll('\\.', '/'))
+					if (jcls == null) {
+						lines.remove(key)
+						println('Invalid: ' + key)
+					} else if (entry['desc'] == '') {
+						if (accessLevel.call(jcls['access']) > accessStr.call(entry['modifier']) && (entry.comment == null || !entry.comment.startsWith('#force '))) {
+							lines.remove(key)
+							println('Invalid Narrowing: ' + key)
+						}
+					} else if (!entry['desc'].contains('(')) {
+						if (!jcls.containsKey('fields') || !jcls['fields'].containsKey(entry['desc'])) {
+							lines.remove(key)
+							println('Invalid: ' + key)
+						} else {
+							def value = jcls['fields'][entry['desc']]
+							if (accessLevel.call(value['access']) > accessStr.call(entry['modifier']) && (entry.comment == null || !entry.comment.startsWith('#force '))) {
+								lines.remove(key)
+								println('Invalid Narrowing: ' + key)
+								println(entry.comment)
+							}
+						}
+					} else {
+						def jdesc = entry['desc'].replace('(', ' (')
+						if (!jcls.containsKey('methods') || !jcls['methods'].containsKey(jdesc)) {
+							lines.remove(key)
+							println('Invalid: ' + key)
+						} else {
+							def value = jcls['methods'][jdesc]
+							if (accessLevel.call(value['access']) > accessStr.call(entry['modifier']) && (entry.comment == null || !entry.comment.startsWith('#force '))) {
+								lines.remove(key)
+								println('Invalid Narrowing: ' + key)
+							}
+						}
+					}
+				}
+			}
+
+			
+			def data = []
+            def remapComment = { entry ->
+                if (!mappings || !entry || !entry.desc) return null
+                def comment = entry.comment?.substring(1)?.trim()
+                def jsonCls = json.get(entry.cls.replaceAll('\\.', '/'))
+                def mappingsClass = mappings?.getClass(jsonCls.name)
+                if (!mappingsClass) return entry.comment
+                def idx = entry.desc.indexOf('(')
+                def mappedName = idx == -1
+                        ? mappingsClass.remapField(entry.desc)
+                        : mappingsClass.remapMethod(entry.desc.substring(0, idx), entry.desc.substring(idx))
+                if (!mappedName) return entry.comment
+                if (mappedName == '<init>')
+                    mappedName = 'constructor'
+
+                if (comment?.startsWith(mappedName))
+                    return '# ' + comment
+                if (comment && comment.indexOf(' ') != -1) {
+                    def split = comment.split(" - ").toList()
+                    if (split[0].indexOf(' ') != -1)
+                        // The first string is more than one word, so append before it
+                        return "# ${mappedName} - ${comment}"
+                    split.remove(0)
+                    return "# ${mappedName} - ${String.join(' - ', split)}"
+                }
+                return '# ' + mappedName
+            }
+			lines.each { key,value -> 
+				if (!value.group) {
+                    def comment = remapComment.call(value)
+					data.add(value.modifier + ' ' + key + (comment ? ' ' + comment : ''))
+				} else {
+					data.add('#group ' + value.modifier + ' ' + key + (value.comment == null ? '' : ' ' + value.comment))
+					value.children.each {
+                        def line = value.modifier + ' ' + it
+                        def (modifier, cls, desc, comment) = parse.call(line)
+                        comment = remapComment.call([modifier: modifier, cls: cls, desc: desc, comment: comment])
+                        data.add(line + (comment ? ' ' + comment : ''))
+                    }
+					data.add('#endgroup')
+				}
+			}
+			f.text = data.join('\n')
+		}
+	}
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/CheckExcs.groovy

@@ -0,0 +1,94 @@
+package net.minecraftforge.forge.tasks
+
+import org.gradle.api.file.ConfigurableFileCollection
+import org.gradle.api.file.RegularFileProperty
+
+import org.gradle.api.DefaultTask
+import org.gradle.api.tasks.InputFile
+import org.gradle.api.tasks.InputFiles
+import org.gradle.api.tasks.TaskAction
+
+import org.objectweb.asm.ClassReader
+import org.objectweb.asm.ClassVisitor
+import org.objectweb.asm.MethodVisitor
+import org.objectweb.asm.Opcodes
+import org.objectweb.asm.Type
+
+import java.util.zip.ZipEntry
+import java.util.zip.ZipInputStream
+
+abstract class CheckExcs extends DefaultTask {
+	@InputFile abstract RegularFileProperty getBinary()
+	@InputFiles abstract ConfigurableFileCollection getExcs()
+	
+    @TaskAction
+    protected void exec() {
+		Util.init()
+		def known = []
+		binary.get().asFile.withInputStream { i ->
+			new ZipInputStream(i).withCloseable { zin ->
+				def visitor = new ClassVisitor(Opcodes.ASM9) {
+					private String cls
+					@Override
+					public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
+						this.cls = name
+					}
+					
+					@Override
+					public MethodVisitor visitMethod(int access, String name, String descriptor, String signature, String[] exceptions) {
+						known.add(this.cls + '.' + name + descriptor)
+						super.visitMethod(access, name, descriptor, signature, exceptions)
+					}
+				}
+				ZipEntry zein
+				while ((zein = zin.nextEntry) != null) {
+					if (zein.name.endsWith('.class')) {
+						ClassReader reader = new ClassReader(zin)
+						reader.accept(visitor, ClassReader.SKIP_CODE | ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES)
+					}
+				}
+			}
+		}
+		
+		excs.each { f -> 
+			def lines = []
+			f.eachLine { line ->
+				def idx = line.indexOf('#')
+				if (idx == 0 || line.isEmpty()) {
+					return
+				}
+				
+				def comment = idx == -1 ? null : line.substring(idx)
+				if (idx != -1) line = line.substring(0, idx - 1)
+				
+				if (!line.contains('=')) {
+					println('Invalid: ' + line)
+					return
+				}
+				
+				def (key, value) = line.split('=', 2)
+				if (!known.contains(key)) {
+					println('Unknown: ' + line)
+					return
+				}
+				
+				def (cls, desc) = key.split('\\.', 2)
+				if (!desc.contains('(')) {
+					println('Invalid: ' + line)
+					return
+				}
+				def name = desc.split('\\(', 2)[0]
+				desc = '(' + desc.split('\\(', 2)[1]
+				
+				def (exceptions, args) = value.contains('|') ? value.split('|', 2) : [value, '']
+				
+				if (args.split(',').length != Type.getArgumentTypes(desc).length) {
+					println('Invalid: ' + line)
+					return
+				}
+				lines.add(line)
+			}
+			f.text = lines.sort().join('\n')
+		}
+	}
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/CheckPatches.groovy

@@ -0,0 +1,219 @@
+package net.minecraftforge.forge.tasks
+
+import org.gradle.api.DefaultTask
+import org.gradle.api.file.DirectoryProperty
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.InputDirectory
+import org.gradle.api.tasks.TaskAction
+
+import java.nio.file.Files
+import java.nio.file.Paths
+import java.util.regex.Pattern
+
+abstract class CheckPatches extends DefaultTask {
+    @InputDirectory abstract DirectoryProperty getPatchDir()
+    @Input boolean autoFix = false
+
+    @TaskAction
+    protected void exec() {
+        def hasS2SArtifact = [
+                Paths.get("patches/minecraft/net/minecraft/client/renderer/ViewArea.java.patch"),
+                Paths.get("patches/minecraft/net/minecraft/data/models/blockstates/Variant.java.patch")
+        ]
+
+        def verified = true;
+        patchDir.get().asFileTree.each { patch ->
+            def patchPath = project.rootDir.toPath().relativize(patch.toPath())
+            verified &= verifyPatch(patch, autoFix, patchPath.toString(), hasS2SArtifact.contains(patchPath))
+        }
+
+        if (!verified)
+            throw new RuntimeException('One or more patches failed verification. Check the log for errors.')
+    }
+
+    def verifyPatch(patch, fix, patchPath, hasS2SArtifact) {
+        def hunk_start_pattern = Pattern.compile('^@@ -[0-9,]* \\+[0-9,_]* @@$')
+        def white_space_pattern = Pattern.compile('^[+\\-]\\s*$')
+        def import_pattern = Pattern.compile('^[+\\-]\\s*import.*')
+        def field_pattern = Pattern.compile('^[+\\-][\\s]*((public|protected|private)[\\s]*)?(static[\\s]*)?(final)?([^=;]*)(=.*)?;\\s*$')
+        def method_pattern = Pattern.compile('^[+\\-][\\s]*((public|protected|private)[\\s]*)?(static[\\s]*)?(final)?([^(]*)[(]([^)]*)?[)]\\s*[{]\\s*$')
+        def class_pattern = Pattern.compile('^[+\\-][\\s]*((public|protected|private)[\\s]*)?(static[\\s]*)?(final[\\s]*)?(class|interface)([^{]*)[{]\\s*$')
+
+        def accessMap = [("private"):0, (null):1, ("protected"):2, ("public"):3]
+
+        def hasProblem = false;
+        def lines = patch.readLines()
+
+        def hunksStart = 0
+        def onlyWhiteSpace = false
+
+        def didFix = false
+        def newLines = []
+        def whiteSpaceErrors = []
+
+        // First two lines are file name ++/-- and we do not care
+        newLines.add(lines[0] + '\n')
+        newLines.add(lines[1] + '\n')
+
+        int i = 2
+        for (; i < lines.size(); ++i) {
+            def line = lines[i]
+            newLines.add(line + '\n')
+
+            if (hunk_start_pattern.matcher(line).find()) {
+                if (onlyWhiteSpace) {
+                    if (fix || hasS2SArtifact) {
+                        logger.lifecycle("Removing white space hunk starting at line {}, file: {}", hunksStart + 1, patchPath)
+                        def toRemove = i - hunksStart;
+                        while (toRemove-- > 0)
+                            newLines.remove(newLines.size() - 1)
+                        didFix = true
+                    }
+                    else {
+                        logger.lifecycle("Patch contains only white space hunk starting at line {}, file: {}", hunksStart + 1, patchPath)
+                        hasProblem = true
+                    }
+                }
+                else {
+                    if (!whiteSpaceErrors.empty)
+                        hasProblem = true
+                    whiteSpaceErrors.each { error -> logger.lifecycle(error) }
+                    whiteSpaceErrors.clear()
+                }
+                hunksStart = i
+                onlyWhiteSpace = true
+                continue
+            }
+
+            if (line.startsWithAny('+','-')) {
+                def prefixChange = false
+                def prevLine = lines[i - 1]
+
+                if (line.charAt(0) == (char)'+' && prevLine.charAt(0) == (char)'-') {
+                    def prevTrim = prevLine.substring(1).replaceAll("\\s", "")
+                    def currTrim = line.substring(1).replaceAll("\\s", "")
+
+                    if (prevTrim.equals(currTrim)) {
+                        prefixChange = true
+                    }
+
+                    def pMatcher = field_pattern.matcher(prevLine)
+                    def cMatcher = field_pattern.matcher(line)
+
+                    if (pMatcher.find() && cMatcher.find() &&
+                            pMatcher.group(6) == cMatcher.group(6) && // = ...
+                            pMatcher.group(5) == cMatcher.group(5) && // field name
+                            pMatcher.group(3) == cMatcher.group(3) && // static
+                            (accessMap[pMatcher.group(2)] < accessMap[cMatcher.group(2)] || pMatcher.group(4) != cMatcher.group(4))) {
+                        logger.lifecycle("Patch contains access changes or final removal at line {}, file: {}", i + 1, patchPath)
+                        hasProblem = true
+                    }
+
+                    pMatcher = method_pattern.matcher(prevLine)
+                    cMatcher = method_pattern.matcher(line)
+
+                    if (pMatcher.find() && cMatcher.find() &&
+                            pMatcher.group(6) == cMatcher.group(6) && // params
+                            pMatcher.group(5) == cMatcher.group(5) && // <T> void name
+                            pMatcher.group(3) == cMatcher.group(3) && // static
+                            (accessMap[pMatcher.group(2)] < accessMap[cMatcher.group(2)] || pMatcher.group(4) != cMatcher.group(4))) {
+                        logger.lifecycle("Patch contains access changes or final removal at line {}, file: {}", i + 1, patchPath)
+                        hasProblem = true
+                    }
+
+                    pMatcher = class_pattern.matcher(prevLine)
+                    cMatcher = class_pattern.matcher(line)
+
+                    if (pMatcher.find() && cMatcher.find() &&
+                            pMatcher.group(6) == cMatcher.group(6) && // ClassName<> extends ...
+                            pMatcher.group(5) == cMatcher.group(5) && // class | interface
+                            pMatcher.group(3) == cMatcher.group(3) && // static
+                            (accessMap[pMatcher.group(2)] < accessMap[cMatcher.group(2)] || pMatcher.group(4) != cMatcher.group(4))) {
+                        logger.lifecycle("Patch contains access changes or final removal at line {}, file: {}", i + 1, patchPath)
+                        hasProblem = true
+                    }
+                }
+
+                if (line.charAt(0) == (char)'-' && i + 1 < lines.size()) {
+                    def nextLine = lines[i + 1]
+                    if (nextLine.charAt(0) == (char)'+') {
+                        def nextTrim = nextLine.substring(1).replaceAll("\\s", "")
+                        def currTrim = line.substring(1).replaceAll("\\s", "")
+
+                        if (nextTrim.equals(currTrim)) {
+                            prefixChange = true
+                        }
+                    }
+                }
+
+                def isWhiteSpaceChange = white_space_pattern.matcher(line).find()
+
+                if (!prefixChange && !isWhiteSpaceChange) {
+                    onlyWhiteSpace = hasS2SArtifact && import_pattern.matcher(line).find()
+                }
+                else if (isWhiteSpaceChange) {
+                    def prevLineChange = prevLine.startsWithAny('+','-')
+                    def nextLineChange = i + 1 < lines.size() && lines[i + 1].startsWithAny('+','-')
+
+                    if (!prevLineChange && !nextLineChange) {
+                        whiteSpaceErrors.add(String.format("Patch contains white space change in valid hunk at line %d (cannot auto fix), file: %s", i + 1, patchPath))
+                    }
+                }
+
+                if (line.contains("\t")) {
+                    if (!fix) {
+                        logger.lifecycle("Patch contains tabs on line {}, file: {}", i + 1, patchPath)
+                        hasProblem = true
+                    }
+                    else {
+                        logger.lifecycle("Fixing tabs on line {}, file: {}", i + 1, patchPath)
+                        line = line.replaceAll('\t', '    ')
+                        newLines.remove(newLines.size() - 1)
+                        newLines.add(line + '\n')
+                        didFix = true
+                    }
+                }
+
+                if (import_pattern.matcher(line).find() && !hasS2SArtifact) {
+                    logger.lifecycle("Patch contains import change on line {}, file: {}", i + 1, patchPath)
+                    hasProblem = true
+                }
+            }
+        }
+
+        if (onlyWhiteSpace) {
+            if (fix || hasS2SArtifact) {
+                logger.lifecycle("Removing white space hunk starting at line {}, file: {}", hunksStart + 1, patchPath)
+                def toRemove = i - hunksStart;
+                while (toRemove-- > 0)
+                    newLines.remove(newLines.size() - 1)
+                didFix = true
+            }
+            else {
+                logger.lifecycle("Patch contains only white space hunk starting at line {}, file: {}", hunksStart + 1, patchPath)
+                hasProblem = true
+            }
+        }
+        else {
+            if (!whiteSpaceErrors.empty)
+                hasProblem = true
+            whiteSpaceErrors.each { error -> logger.lifecycle(error) }
+        }
+
+        if (didFix) {
+            if (newLines.size() <= 2) {
+                logger.lifecycle("Patch is now empty removing, file: {}", patchPath)
+                Files.delete(patch.toPath())
+            }
+            else {
+                if (!hasS2SArtifact)
+                    logger.lifecycle("*** Updating patch file. Please run setup then genPatches again. ***")
+                patch.withWriter('UTF-8') { writer ->
+                    newLines.each { l -> writer.write(l) }
+                }
+            }
+        }
+
+        return !hasProblem
+    }
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/CheckSAS.groovy

@@ -0,0 +1,63 @@
+package net.minecraftforge.forge.tasks
+
+import org.gradle.api.file.ConfigurableFileCollection
+import org.gradle.api.file.RegularFileProperty
+
+import org.gradle.api.DefaultTask
+import org.gradle.api.tasks.InputFile
+import org.gradle.api.tasks.InputFiles
+import org.gradle.api.tasks.TaskAction
+
+abstract class CheckSAS extends DefaultTask {
+	@InputFile abstract RegularFileProperty getInheritance()
+	@InputFiles abstract ConfigurableFileCollection getSass()
+	
+    @TaskAction
+    protected void exec() {
+		Util.init()
+		def json = inheritance.get().asFile.json()
+		
+		sass.each { f -> 
+			def lines = []
+			f.eachLine { line ->
+				if (line[0] == '\t') return //Skip any tabbed lines, those are ones we add
+				def idx = line.indexOf('#')
+				if (idx == 0 || line.isEmpty()) {
+					lines.add(line)
+					return
+				}
+				def comment = idx == -1 ? null : line.substring(idx)
+				if (idx != -1) line = line.substring(0, idx - 1)
+				def (cls, desc) = (line.trim() + '    ').split(' ', -1)
+				cls = cls.replaceAll('\\.', '/')
+				desc = desc.replace('(', ' (')
+
+				if (json[cls] == null || (!desc.isEmpty() && (json[cls]['methods'] == null || json[cls]['methods'][desc] == null))) {
+					println('Invalid: ' + line)
+					return
+				}
+
+				//Class SAS
+				if (desc.isEmpty()) {
+					lines.add(cls + (comment == null ? '' : ' ' + comment))
+					if (json[cls]['methods'] != null)
+						(json[cls]['methods'] as TreeMap).each {
+							findChildMethods(json, cls, it.key).each { lines.add('\t' + it) }
+						}
+					return
+				}
+
+				//Method SAS
+				lines.add(cls + ' ' + desc.replace(' ', '') + (comment == null ? '' : ' ' + comment))
+				findChildMethods(json, cls, desc).each { lines.add('\t' + it) }
+			}
+			f.text = lines.join('\n')
+		}
+	}
+
+	protected static findChildMethods(json, cls, desc)
+	{
+		return json.values().findAll{ it.methods != null && it.methods[desc] != null && it.methods[desc].override == cls}
+				.collect { it.name + ' ' + desc.replace(' ', '') } as TreeSet
+	}
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/ClosureHelper.groovy

@@ -0,0 +1,31 @@
+package net.minecraftforge.forge.tasks
+
+import java.util.function.BiConsumer
+
+public class ClosureHelper {
+    BiConsumer<String, Closure> callback
+    
+    public ClosureHelper(Closure cl, BiConsumer<String, Closure> callback) {
+        this.callback = callback
+        apply(this, cl)
+    }
+    
+    
+    def methodMissing(String name, Object args) {
+        if (!args.class.isArray()) return
+        Object[] aargs = (Object[])args
+        
+        if (aargs.length == 1 && aargs[0] instanceof Closure) {
+            this.callback.accept(name, (Closure)aargs[0])
+        } else {
+            throw new IllegalArgumentException('Unknown method: "' + name + '" with arguments ' + args + ' for ' + this)
+        }
+    }
+    
+    static <T> T apply(T obj, Closure cl) {
+        cl.delegate = obj
+        cl.resolveStrategy = Closure.DELEGATE_FIRST
+        cl()
+        return obj
+    }
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/Crowdin.groovy

@@ -0,0 +1,73 @@
+package net.minecraftforge.forge.tasks
+
+import org.gradle.api.DefaultTask
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.provider.Property
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.Optional
+import org.gradle.api.tasks.OutputFile
+import org.gradle.api.tasks.TaskAction
+
+import java.util.zip.ZipEntry
+import java.util.zip.ZipInputStream
+import java.util.zip.ZipOutputStream
+
+abstract class Crowdin extends DefaultTask {
+    @Input abstract Property<String> getId()
+	@Input @Optional abstract Property<String> getKey()
+	@Input boolean json = true
+	@OutputFile abstract RegularFileProperty getOutput()
+	@OutputFile abstract RegularFileProperty getExport()
+
+    Crowdin() {
+		outputs.upToDateWhen{ false }
+		id.convention('minecraft-forge')
+		output.convention(project.layout.buildDirectory.dir(name).map {it.file("output.zip") })
+		export.convention(project.layout.buildDirectory.dir(name).map {it.file("export.json") })
+	}
+
+    @TaskAction
+    def run() {
+		File outputFile = output.get().asFile
+		File exportFile = export.get().asFile
+		if (outputFile.exists())
+			outputFile.delete()
+		
+		if (!key.isPresent())
+			return
+		String key = this.key.get()
+		String id = this.id.get()
+		
+		// Force an export
+		new URL("https://api.crowdin.com/api/project/${id}/export?key=${key}").withInputStream { i ->
+			exportFile.withOutputStream { it << i }
+		}
+		
+		if (!exportFile.text.contains('success')) {
+			throw new RuntimeException("Crowdin export failed, see ${exportFile} for more info")
+		}
+
+		new URL("https://api.crowdin.com/api/project/${id}/download/all.zip?key=${key}").withInputStream { i -> 
+			new ZipInputStream(i).withCloseable { zin ->
+				outputFile.withOutputStream { out ->
+					new ZipOutputStream(out).withCloseable { zout -> 
+						ZipEntry zein
+						while ((zein = zin.nextEntry) != null) {
+							if (zein.isDirectory()) {
+								zout.putNextEntry(new ZipEntry(zein.name))
+							} else {
+								// 1.13+ uses json
+								if (zein.name.endsWith('.json') == json) {
+									ZipEntry zeout = new ZipEntry(json ? zein.name.toLowerCase() : zein.name)
+									zeout.time = 1
+									zout.putNextEntry(zeout)
+									zout << zin
+								}
+							}
+						}
+					}
+				}
+			}
+		}
+    }
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/DownloadLibraries.groovy

@@ -0,0 +1,54 @@
+package net.minecraftforge.forge.tasks
+
+import org.gradle.api.DefaultTask
+import org.gradle.api.file.ConfigurableFileCollection
+import org.gradle.api.file.DirectoryProperty
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.tasks.InputFile
+import org.gradle.api.tasks.Internal
+import org.gradle.api.tasks.OutputFile
+import org.gradle.api.tasks.OutputFiles
+import org.gradle.api.tasks.TaskAction
+import org.gradle.api.tasks.OutputDirectory
+
+import java.nio.file.Files
+
+abstract class DownloadLibraries extends DefaultTask {
+	@InputFile abstract RegularFileProperty getInput()
+	@OutputDirectory abstract DirectoryProperty getOutput()
+	@OutputFile abstract RegularFileProperty getLibrariesOutput()
+
+    DownloadLibraries() {
+		output.convention(project.layout.buildDirectory.dir(name))
+        librariesOutput.convention(project.layout.buildDirectory.dir(name).map(d -> d.file('libraries.txt')))
+	}
+
+    @TaskAction
+    def run() {
+		Util.init()
+		File outputDir = output.get().asFile
+        def libraries = new ArrayList()
+
+		def json = input.get().asFile.json().libraries.each { lib ->
+		    //TODO: Thread?
+			def artifacts = [lib.downloads.artifact] + lib.downloads.get('classifiers', [:]).values()
+			artifacts.each{ art -> 
+				def target = new File(outputDir, art.path)
+				libraries.add(target.absolutePath)
+				if (!target.exists() || !art.sha1.equals(target.sha1())) {
+					project.logger.lifecycle("Downloading ${art.url}")
+					if (!target.parentFile.exists()) {
+						target.parentFile.mkdirs()
+					}
+					new URL(art.url).withInputStream { i ->
+						target.withOutputStream { it << i }
+					}
+					if (!art.sha1.equals(target.sha1())) {
+						throw new IllegalStateException("Failed to download ${art.url} to ${target.canonicalPath} SHA Mismatch")
+					}
+				}
+			}
+		}
+        Files.write(librariesOutput.get().asFile.toPath(), libraries)
+    }
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/FieldCompareFinder.groovy

@@ -0,0 +1,109 @@
+package net.minecraftforge.forge.tasks
+
+import groovy.transform.EqualsAndHashCode
+
+import java.util.ArrayList
+import java.util.HashMap
+import java.util.TreeMap
+import java.util.TreeSet
+import java.util.function.BiConsumer
+
+import org.gradle.api.DefaultTask
+import org.gradle.api.tasks.*
+
+import org.objectweb.asm.Opcodes
+import org.objectweb.asm.Type
+import org.objectweb.asm.tree.ClassNode
+import org.objectweb.asm.tree.FieldNode
+import org.objectweb.asm.tree.MethodNode
+
+import static org.objectweb.asm.Opcodes.*
+
+abstract class FieldCompareFinder extends BytecodeFinder {
+    @Nested
+    Map<String, Search> fields = [:] as HashMap
+    @Internal
+    Map<Search, String> fieldsReverse = [:] as HashMap
+    @Internal
+    Map<String, Set<ObjectTarget>> targets = [:] as TreeMap
+    
+    @Override
+    protected pre() {
+        //fields.each{ k,v -> logger.lifecycle("Fields: " + k + ' ' + v) }
+    }
+    
+    @Override
+    protected process(ClassNode parent, MethodNode node) {
+        def last = null
+        def parentInstance = new ObjectTarget(owner: parent.name, name: '', desc: '')
+        for (int x = 0; x < node.instructions.size(); x++) {
+            def current = node.instructions.get(x)
+            if (current.opcode == IF_ACMPEQ || current.opcode == IF_ACMPNE) {
+                if (last != null && (last.opcode == GETSTATIC || last.opcode == GETFIELD)) {
+                    def target = new Search(cls: last.owner, name: last.name)
+                    def wanted = fieldsReverse.get(target)
+                    def original = fields.get(wanted)
+                    def instance = new ObjectTarget(owner: parent.name, name: node.name, desc: node.desc)
+                    if (wanted != null && (original.blacklist == null || (!original.blacklist.contains(instance) && !original.blacklist.contains(parentInstance)))) {
+                        targets.computeIfAbsent(wanted, { k -> new TreeSet() }).add(instance)
+                    }
+                }
+            }
+            last = current
+        }
+    }
+    
+    @Internal
+    @Override
+    protected Object getData() {
+		def ret = [:] as HashMap
+		targets.forEach{ k, v -> 
+			def e = fields.get(k)
+			ret[k] = [
+				cls: e.cls, 
+				name: e.name, 
+				replacement: e.replacement, 
+				targets: v
+			]
+		}
+        return ret
+    }
+    
+    @EqualsAndHashCode(excludes = ['replacement', 'blacklist'])
+    public static class Search {
+        @Input
+        String cls
+        
+        @Input
+        String name
+		
+		@Input
+		String replacement
+    
+        @Nested
+        @Optional
+        Set<ObjectTarget> blacklist
+        
+        @Override
+        String toString() {
+            return cls + '.' + name
+        }
+        
+        def blacklist(def owner, def name, def desc) {
+            if (blacklist == null)
+                blacklist = new HashSet()
+            blacklist.add(new ObjectTarget(owner: owner, name: name, desc: desc))
+        }
+        def blacklist(def owner) {
+            blacklist(owner, '', '')
+        }
+    }
+    
+    def fields(Closure cl) {
+        new ClosureHelper(cl, {name, ccl ->
+            def search = ClosureHelper.apply(new Search(), ccl)
+            this.fields.put(name, search)
+            this.fieldsReverse.put(search, name)
+        })
+    }
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/InheritanceData.groovy

@@ -0,0 +1,49 @@
+package net.minecraftforge.forge.tasks
+
+import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
+import groovy.transform.CompileStatic
+import groovy.transform.TupleConstructor
+
+@CompileStatic
+@TupleConstructor
+final class InheritanceData implements Annotatable {
+    String name
+    int access
+    String superName
+    List<String> interfaces = []
+    Map<String, Method> methods = [:]
+    Map<String, Field> fields = [:]
+    List<Annotation> annotations = []
+
+    @TupleConstructor
+    static final class Method implements Annotatable {
+        int access
+        String override
+        List<Annotation> annotations = []
+    }
+
+    @TupleConstructor
+    static final class Field implements Annotatable {
+        int access
+        String desc
+        List<Annotation> annotations = []
+    }
+
+    @TupleConstructor
+    static final class Annotation {
+        String desc
+    }
+
+    private static final Gson GSON = new Gson()
+    static Map<String, InheritanceData> parse(File file) {
+        try (final reader = file.newReader()) {
+            return GSON.fromJson(reader, new TypeToken<Map<String, InheritanceData>>() {})
+        }
+    }
+}
+
+@CompileStatic
+interface Annotatable {
+    List<InheritanceData.Annotation> getAnnotations()
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/InstallerJar.groovy

@@ -0,0 +1,44 @@
+package net.minecraftforge.forge.tasks
+
+import org.gradle.api.tasks.bundling.Zip
+import org.gradle.api.tasks.*
+import org.gradle.api.provider.SetProperty
+
+abstract class InstallerJar extends Zip {
+    @Input @Optional abstract SetProperty<String> getPackedDependencies()
+    
+    InstallerJar() {
+        archiveClassifier.set('installer')
+        archiveExtension.set('jar') // Needs to be Zip task to not override Manifest, so set extension
+        destinationDirectory.set(project.layout.buildDirectory.dir('libs'))
+
+        def installerJson = project.tasks.installerJson
+        def launcherJson = project.tasks.launcherJson
+        def downloadInstaller = project.tasks.downloadInstaller
+        
+        dependsOn(installerJson, launcherJson, downloadInstaller)
+        from(installerJson, launcherJson)
+
+        from(project.rootProject.file('/src/main/resources/url.png'))
+        project.afterEvaluate {
+            from(project.zipTree(downloadInstaller.output)) {
+                duplicatesStrategy = 'exclude'
+            }
+            
+            if (!System.env.MAVEN_USER) {
+                dependsOn(project.universalJar)
+                from(project.universalJar) {
+                    into '/maven/' + project.group.replace('.', '/') + '/' + project.universalJar.archiveBaseName.get() + '/' + project.version + '/'
+                }
+    
+                packedDependencies.get().forEach {
+                    def jarTask = project.rootProject.getTasks().findByPath(it)
+                    dependsOn(jarTask)
+                    from(jarTask) {
+                        into '/maven/' + jarTask.project.group.replace('.', '/') + '/' + jarTask.archiveBaseName.get() + '/' + jarTask.project.version + '/'
+                    }
+                }
+            }
+        }
+    }
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/InstallerJson.groovy

@@ -0,0 +1,81 @@
+package net.minecraftforge.forge.tasks
+
+import groovy.json.JsonBuilder
+import org.gradle.api.DefaultTask
+import org.gradle.api.file.ConfigurableFileCollection
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.provider.Property
+import org.gradle.api.provider.SetProperty
+import org.gradle.api.tasks.*
+
+import java.nio.file.Files
+
+abstract class InstallerJson extends DefaultTask {
+    @OutputFile abstract RegularFileProperty getOutput()
+    @InputFiles abstract ConfigurableFileCollection getInput()
+    @Input @Optional abstract SetProperty<String> getPackedDependencies()
+    @Input @Optional final Map<String, Object> libraries = new LinkedHashMap<>()
+    @Input Map<String, Object> json = new LinkedHashMap<>()
+    @InputFile abstract RegularFileProperty getIcon()
+    @Input abstract Property<String> getLauncherJsonName()
+    @Input abstract Property<String> getLogo()
+    @Input abstract Property<String> getMirrors()
+    @Input abstract Property<String> getWelcome()
+
+    InstallerJson() {
+        getLauncherJsonName().convention('/version.json')
+        getLogo().convention('/big_logo.png')
+        getMirrors().convention('https://files.minecraftforge.net/mirrors-2.0.json')
+        getWelcome().convention("Welcome to the simple ${project.name.capitalize()} installer.")
+                
+        getOutput().convention(project.layout.buildDirectory.file('install_profile.json'))
+
+        ['client', 'server'].each { side ->
+            ['slim', 'extra'].each { type ->
+                def tsk = project.tasks.getByName("download${side.capitalize()}${type.capitalize()}")
+                dependsOn(tsk)
+                input.from(tsk.output)
+            }
+            def tsk = project.tasks.getByName("create${side.capitalize()}SRG")
+            dependsOn(tsk)
+            input.from(tsk.output)
+        }
+
+        
+        project.afterEvaluate {
+            (packedDependencies.get().collect{ project.rootProject.tasks.findByPath(it) } + [project.universalJar]).forEach {
+                dependsOn(it)
+                input.from it.archiveFile
+            }
+        }
+    }
+
+    @TaskAction
+    protected void exec() {
+        def libs = libraries
+        for (def child : packedDependencies.get().collect{ project.rootProject.tasks.findByPath(it) } + [project.universalJar]) {
+            def dep = Util.getMavenDep(child)
+            def path = Util.getMavenPath(child)
+            libs.put(dep.toString(), [
+                name: dep,
+                downloads: [
+                    artifact: [
+                        path: path,
+                        url: "https://maven.minecraftforge.net/${path}",
+                        sha1: child.archiveFile.get().asFile.sha1(),
+                        size: child.archiveFile.get().asFile.length()
+                    ]
+                ]
+            ])
+        }
+        json.libraries = libs.values().sort{a,b -> a.name.compareTo(b.name)}
+        json.icon = "data:image/png;base64," + new String(Base64.getEncoder().encode(Files.readAllBytes(icon.get().asFile.toPath())))
+        json.json = launcherJsonName.get()
+        json.logo = logo.get()
+        if (!mirrors.get().isEmpty())
+            json.mirrorList = mirrors.get()
+        json.welcome = welcome.get()
+
+        Files.writeString(output.get().getAsFile().toPath(), new JsonBuilder(json).toPrettyString())
+    }
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/LauncherJson.groovy

@@ -0,0 +1,74 @@
+package net.minecraftforge.forge.tasks
+
+import groovy.json.JsonBuilder
+import org.gradle.api.DefaultTask
+import org.gradle.api.file.ConfigurableFileCollection
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.provider.SetProperty
+import org.gradle.api.tasks.*
+
+import java.nio.file.Files
+
+import static net.minecraftforge.forge.tasks.Util.getArtifacts
+import static net.minecraftforge.forge.tasks.Util.iso8601Now
+
+abstract class LauncherJson extends DefaultTask {
+    @OutputFile abstract RegularFileProperty getOutput()
+    @InputFiles abstract ConfigurableFileCollection getInput()
+    @Input Map<String, Object> json = new LinkedHashMap<>()
+    @Input @Optional abstract SetProperty<String> getPackedDependencies()
+    
+    @Internal final vanilla = project.project(':mcp').file('build/mcp/downloadJson/version.json')
+    @Internal final timestamp = iso8601Now()
+    @Internal final comment = [
+        "Please do not automate the download and installation of Forge.",
+        "Our efforts are supported by ads from the download page.",
+        "If you MUST automate this, please consider supporting the project through https://www.patreon.com/LexManos/"
+    ]
+    @Internal final id = "${project.rootProject.ext.MC_VERSION}-${project.name}${project.version.substring(project.rootProject.ext.MC_VERSION.length())}"
+
+    LauncherJson() {
+        getOutput().convention(project.layout.buildDirectory.file('version.json'))
+
+        dependsOn(':fmlloader:jar', 'universalJar')
+        getInput().from(project.tasks.universalJar.archiveFile,
+                project.project(':fmlloader').jar.archiveFile,
+                vanilla)
+                
+        project.afterEvaluate {
+            packedDependencies.get().forEach {
+                def jarTask = project.rootProject.tasks.findByPath(it)
+                dependsOn(jarTask)
+                input.from jarTask.archiveFile
+            }
+        }
+    }
+
+    @TaskAction
+    protected void exec() {
+        if (!json.libraries)
+            json.libraries = []
+        def libs = [:]
+        getArtifacts(project, project.configurations.installer, false).each { key, lib -> libs[key] = lib }
+        getArtifacts(project, project.configurations.moduleonly, false).each { key, lib -> libs[key] = lib }
+
+        packedDependencies.get().collect{ project.rootProject.tasks.findByPath(it) }.forEach {
+            def path = Util.getMavenPath(it)
+            def key = Util.getMavenDep(it)
+            
+            libs[key] = [
+                name: key,
+                downloads: [
+                    artifact: [
+                        path: path,
+                        url: "https://maven.minecraftforge.net/${path}",
+                        sha1: it.archiveFile.get().asFile.sha1(),
+                        size: it.archiveFile.get().asFile.length()
+                    ]
+                ]
+            ]
+        }
+        libs.each { key, lib -> json.libraries.add(lib) }
+        Files.writeString(output.get().asFile.toPath(), new JsonBuilder(json).toPrettyString())
+    }
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/MergeJars.groovy

@@ -0,0 +1,44 @@
+package net.minecraftforge.forge.tasks
+
+import org.apache.commons.io.IOUtils
+import org.gradle.api.DefaultTask
+import org.gradle.api.file.ConfigurableFileCollection
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.tasks.InputFiles
+import org.gradle.api.tasks.OutputFile
+import org.gradle.api.tasks.TaskAction
+
+import java.util.zip.ZipEntry
+import java.util.zip.ZipInputStream
+import java.util.zip.ZipOutputStream
+
+abstract class MergeJars extends DefaultTask {
+    MergeJars() {
+        output.convention(project.layout.buildDirectory.dir(name).map { it.file('output.jar') })
+    }
+
+    @TaskAction
+    void run() {
+        def jars = inputJars.files
+
+        try (ZipOutputStream zout = new ZipOutputStream(new FileOutputStream(output.get().asFile))) {
+            for (def jar : jars) {
+                try (ZipInputStream zin = new ZipInputStream(new FileInputStream(jar))) {
+                    def entry
+                    while ((entry = zin.getNextEntry()) != null) {
+                        ZipEntry _new = new ZipEntry(entry.getName())
+                        _new.setTime(0) //SHOULD be the same time as the main entry, but NOOOO _new.setTime(entry.getTime()) throws DateTimeException, so you get 0, screw you!
+                        zout.putNextEntry(_new)
+                        IOUtils.copy(zin, zout)
+                    }
+                }
+            }
+        }
+    }
+
+    @InputFiles
+    abstract ConfigurableFileCollection getInputJars()
+
+    @OutputFile
+    abstract RegularFileProperty getOutput()
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/ObjectTarget.groovy

@@ -0,0 +1,32 @@
+package net.minecraftforge.forge.tasks
+
+import groovy.transform.EqualsAndHashCode
+
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.Nested
+import org.gradle.api.tasks.Optional
+
+@EqualsAndHashCode
+public class ObjectTarget implements Comparable<ObjectTarget> {
+    @Input
+    String owner
+    
+    @Input
+    String name
+    
+    @Input
+    @Optional
+    String desc
+    
+    @Override
+    String toString() {
+        if (desc == null)
+            return owner + '.' + name
+        return owner + '.' + name + desc
+    }
+    
+    @Override
+    int compareTo(ObjectTarget o) {
+        return toString().compareTo(o.toString())
+    }
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/SetupCheckJarCompatibility.groovy

@@ -0,0 +1,47 @@
+package net.minecraftforge.forge.tasks
+
+import org.gradle.api.DefaultTask
+import org.gradle.api.artifacts.Dependency
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.provider.Property
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.Optional
+import org.gradle.api.tasks.OutputFile
+import org.gradle.api.tasks.TaskAction
+
+import java.nio.file.Files
+import java.nio.file.StandardCopyOption
+
+abstract class SetupCheckJarCompatibility extends DefaultTask {
+    SetupCheckJarCompatibility() {
+        group = 'jar compatibility'
+        onlyIf {
+            inputVersion.getOrNull() != null
+        }
+        outputs.upToDateWhen { false } // Never up to date, because this setup task should always run
+
+        baseBinPatchesOutput.convention(project.layout.buildDirectory.dir(name).map { it.file('joined.lzma') })
+    }
+
+    @TaskAction
+    void run() {
+        def inputVersion = inputVersion.get()
+
+        def baseForgeUserdev = project.layout.buildDirectory.dir(name).map { it.file("forge-${inputVersion}-userdev.jar") }.get().asFile
+        project.rootProject.extensions.download.run {
+            src "https://maven.minecraftforge.net/net/minecraftforge/forge/${inputVersion}/forge-${inputVersion}-userdev.jar"
+            dest baseForgeUserdev
+        }
+
+        def joinedLzma = project.zipTree(baseForgeUserdev).matching { it.include('joined.lzma') }.singleFile
+
+        Files.copy(joinedLzma.toPath(), baseBinPatchesOutput.get().asFile.toPath(), StandardCopyOption.REPLACE_EXISTING)
+    }
+
+    @Input
+    @Optional
+    abstract Property<String> getInputVersion()
+
+    @OutputFile
+    abstract RegularFileProperty getBaseBinPatchesOutput()
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/Util.groovy

@@ -0,0 +1,146 @@
+package net.minecraftforge.forge.tasks
+
+import groovy.json.JsonSlurper
+
+import java.io.File
+import java.security.MessageDigest
+import java.text.SimpleDateFormat
+import java.util.Date
+
+public class Util {
+	static void init() {
+		File.metaClass.sha1 = { ->
+			MessageDigest md = MessageDigest.getInstance('SHA-1')
+			delegate.eachByte 4096, {bytes, size ->
+				md.update(bytes, 0, size)
+			}
+			return md.digest().collect {String.format "%02x", it}.join()
+		}
+	
+		File.metaClass.json = { -> new JsonSlurper().parseText(delegate.text) }
+		
+		Date.metaClass.iso8601 = { ->
+			def format = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ")
+			def result = format.format(delegate)
+			return result[0..21] + ':' + result[22..-1]
+		}
+        
+        String.metaClass.rsplit = { String del, int limit = -1 ->
+            def lst = new ArrayList()
+            def x = 0, idx
+            def tmp = delegate
+            while ((idx = tmp.lastIndexOf(del)) != -1 && (limit == -1 || x++ < limit)) {
+                lst.add(0, tmp.substring(idx + del.length(), tmp.length()))
+                tmp = tmp.substring(0, idx)
+            }
+            lst.add(0, tmp)
+            return lst
+        }
+	}
+	
+	public static String[] getClasspath(project, libs, artifact) {
+		def ret = []
+		artifactTree(project, artifact).each { key, lib ->
+			libs[lib.name] = lib
+			if (lib.name != artifact)
+				ret.add(lib.name)
+		}
+		return ret
+	}
+	
+	public static def getArtifacts(project, config, classifiers) {
+		def ret = [:]
+		config.resolvedConfiguration.resolvedArtifacts.each {
+			def art = [
+				group: it.moduleVersion.id.group,
+				name: it.moduleVersion.id.name,
+				version: it.moduleVersion.id.version,
+				classifier: it.classifier,
+				extension: it.extension,
+				file: it.file
+			]
+			def key = art.group + ':' + art.name
+			def folder = "${art.group.replace('.', '/')}/${art.name}/${art.version}/"
+			def filename = "${art.name}-${art.version}"
+			if (art.classifier != null)
+				filename += "-${art.classifier}"
+			filename += ".${art.extension}"
+			def path = "${folder}${filename}"
+			def url = "https://libraries.minecraft.net/${path}"
+			if (!checkExists(url)) {
+				url = "https://maven.minecraftforge.net/${path}"
+			}
+			//TODO remove when Mojang launcher is updated
+			if (!classifiers && art.classifier != null) { 
+				//Mojang launcher doesn't currently support classifiers, so... move it to part of the version, and force the extension to 'jar'
+				// However, keep the path normal so that our mirror system works.
+				art.version = "${art.version}-${art.classifier}"
+				art.classifier = null
+				art.extension = 'jar'
+			}
+			ret[key] = [
+				name: "${art.group}:${art.name}:${art.version}" + (art.classifier == null ? '' : ":${art.classifier}") + (art.extension == 'jar' ? '' : "@${art.extension}"),
+				downloads: [
+					artifact: [
+						path: path,
+						url: url,
+						sha1: sha1(art.file),
+						size: art.file.length()
+					]
+				]
+			]
+		}
+		return ret
+	}
+    
+    public static def getMavenPath(task) {        
+        def classifier = task.archiveClassifier.get()
+        def dep = "${task.project.group}:${task.project.name}:${task.project.version}" + (classifier == '' ? '' : ':' + classifier)
+        return "${task.project.group.replace('.', '/')}/${task.project.name}/${task.project.version}/${task.project.name}-${task.project.version}".toString() + (classifier == '' ? '' : '-' + classifier) + '.jar'
+    }
+    
+    public static def getMavenDep(task) {        
+        def classifier = task.archiveClassifier.get()
+        return "${task.project.group}:${task.project.name}:${task.project.version}" + (classifier == '' ? '' : ':' + classifier)
+    }
+
+	public static def iso8601Now() { new Date().iso8601() }
+
+	public static def sha1(file) {
+		MessageDigest md = MessageDigest.getInstance('SHA-1')
+		file.eachByte 4096, {bytes, size ->
+			md.update(bytes, 0, size)
+		}
+		return md.digest().collect {String.format "%02x", it}.join()
+	}
+
+	private static def artifactTree(project, artifact) {
+		if (!project.ext.has('tree_resolver'))
+			project.ext.tree_resolver = 1
+		def cfg = project.configurations.create('tree_resolver_' + project.ext.tree_resolver++)
+		def dep = project.dependencies.create(artifact)
+		cfg.dependencies.add(dep)
+		def files = cfg.resolve()
+		return getArtifacts(project, cfg, true)
+	}
+	
+	private static boolean checkExists(url) {
+		try {
+			def code = new URL(url).openConnection().with {
+				requestMethod = 'HEAD'
+				connect()
+				responseCode
+			}
+			return code == 200
+		} catch (Exception e) {
+			if (e.toString().contains('unable to find valid certification path to requested target'))
+				throw new RuntimeException('Failed to connect to ' + url + ': Missing certificate root authority, try updating java')
+			throw e
+		}
+	}
+
+	public static String getLatestForgeVersion(mcVersion) {
+		def json = new JsonSlurper().parseText(new URL("https://files.minecraftforge.net/net/minecraftforge/forge/promotions_slim.json").getText("UTF-8"))
+		return json.promos["$mcVersion-latest"]
+	}
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/checks/CheckATs.groovy

@@ -0,0 +1,310 @@
+package net.minecraftforge.forge.tasks.checks
+
+import groovy.transform.CompileStatic
+import groovy.transform.TupleConstructor
+import net.minecraftforge.forge.tasks.InheritanceData
+import net.minecraftforge.srgutils.IMappingFile
+import org.gradle.api.file.ConfigurableFileCollection
+import org.gradle.api.file.RegularFile
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.tasks.InputFile
+import org.gradle.api.tasks.InputFiles
+import org.gradle.api.tasks.Optional
+import org.objectweb.asm.Opcodes
+
+@CompileStatic
+abstract class CheckATs extends CheckTask {
+
+    @InputFile abstract RegularFileProperty getInheritance()
+    @InputFiles abstract ConfigurableFileCollection getAts()
+    @InputFile @Optional abstract RegularFileProperty getMappings()
+
+    @Override
+    void check(Reporter reporter, boolean fix) {
+        final IMappingFile mappings = mappings.map { RegularFile it -> IMappingFile.load(it.asFile) }.getOrNull()
+        final inheritance = InheritanceData.parse(this.inheritance.get().asFile)
+
+        ats.each {
+            final lines = process(it, reporter, inheritance)
+            if (fix) {
+                it.text = joinBack(lines, inheritance, mappings).join('\n')
+            }
+        }
+    }
+
+    private static TreeMap<String, ATParser.Entry> process(File file, Reporter reporter, Map<String, InheritanceData> inheritance) {
+        final TreeMap<String, ATParser.Entry> lines = ATParser.parse(file.readLines(), reporter)
+        final Map<String, ATParser.Entry> constructorGroups = [:]
+
+        final itr = lines.entrySet().iterator()
+        final toRemove = []
+        while (itr.hasNext()) {
+            final next = itr.next()
+            String key = next.key
+            final entry = next.value
+            if (entry === null) continue
+
+            final binaryName = entry.cls.replaceAll('\\.', '/')
+
+            // Process Groups, this will remove any entries outside the group that is covered by the group
+            if (entry.group) {
+                final jcls = inheritance[binaryName]
+                if (jcls === null) {
+                    itr.remove()
+                    reporter.report("Invalid group: $key")
+                } else if ('*' == entry.desc) {
+                    if (!jcls.fields) {
+                        itr.remove()
+                        reporter.report("Invalid group, class has no fields: $key")
+                    } else {
+                        jcls.fields.each { field, value ->
+                            final fkey = entry.cls + ' ' + field
+                            if (accessLevel(value.access) < accessStr(entry.modifier)) {
+                                if (lines.containsKey(fkey)) {
+                                    toRemove.add(fkey)
+                                } else if (!entry.existing.contains(fkey)) {
+                                    reporter.report("Missing group entry: $fkey")
+                                }
+                                entry.children.add(fkey)
+                            } else if (lines.containsKey(fkey)) {
+                                toRemove.add(fkey)
+                                reporter.report("Found invalid group entry: $fkey")
+                            }
+                        }
+                        entry.existing.findAll { it !in entry.children }.each { println('Removed: ' + it) }
+                    }
+                } else if ('*()' == entry.desc) {
+                    if (!jcls.methods) {
+                        itr.remove()
+                        reporter.report("Invalid group, class has no methods: $key")
+                    } else {
+                        jcls.methods.each { mtd, value ->
+                            if (mtd.startsWith('<clinit>') || mtd.startsWith('lambda$')) return
+                            key = entry.cls + ' ' + mtd.replace(' ', '')
+                            if (accessLevel(value.access) < accessStr(entry.modifier)) {
+                                if (lines.containsKey(key)) {
+                                    toRemove.add(key)
+                                } else if (!entry.existing.contains(key)) {
+                                    reporter.report("Missing group entry: $key")
+                                }
+                                entry.children.add(key)
+                            } else if (lines.containsKey(key)) {
+                                toRemove.add(key)
+                                reporter.report("Found invalid group entry: $key")
+                            }
+                        }
+                        entry.existing.findAll { it !in entry.children }.each { println('Removed: ' + it) }
+                    }
+                } else if ('<init>' == entry.desc) { //Make all public non-abstract subclasses
+                    constructorGroups.put(binaryName, entry)
+                }
+            }
+
+            // Process normal lines, remove invalid and remove narrowing
+            else {
+                def jcls = inheritance.get(binaryName)
+                if (jcls === null) {
+                    itr.remove()
+                    reporter.report("Invalid: $key")
+                } else if (entry.desc == '') {
+                    if (accessLevel(jcls.access) > accessStr(entry.modifier) && (entry.comment === null || !entry.comment.startsWith('#force '))) {
+                        itr.remove()
+                        reporter.report("Invalid Narrowing: $key")
+                    }
+                } else if (!entry.desc.contains('(')) {
+                    if (!jcls.fields || !jcls.fields.containsKey(entry.desc)) {
+                        itr.remove()
+                        reporter.report("Invalid: $key")
+                    } else {
+                        final value = jcls.fields[entry.desc]
+                        if (accessLevel(value.access) > accessStr(entry.modifier) && (entry.comment === null || !entry.comment.startsWith('#force '))) {
+                            itr.remove()
+                            reporter.report("Invalid Narrowing: $key - ${entry.comment}")
+                        }
+                    }
+                } else {
+                    final jdesc = entry.desc.replace('(', ' (')
+                    if (!jcls.methods || !jcls.methods.containsKey(jdesc)) {
+                        itr.remove()
+                        reporter.report("Invalid: $key")
+                    } else {
+                        final value = jcls.methods[jdesc]
+                        if (accessLevel(value.access) > accessStr(entry.modifier) && (entry.comment === null || !entry.comment.startsWith('#force '))) {
+                            itr.remove()
+                            reporter.report("Invalid Narrowing: $key")
+                        }
+                    }
+                }
+            }
+        }
+
+        inheritance.each { tcls, value ->
+            if (!value.methods || ((value.access & Opcodes.ACC_ABSTRACT) !== 0)) return
+            String parent = tcls
+            while (parent !== null) {
+                constructorGroups[parent]?.tap { entry ->
+                    value.methods.each { mtd, v ->
+                        if (mtd.startsWith('<init>')) {
+                            final child = tcls.replaceAll('/', '\\.') + ' ' + mtd.replace(' ', '')
+                            if (accessLevel(v.access) < 3) {
+                                if (lines.containsKey(child)) {
+                                    toRemove.add(child)
+                                } else if (child !in entry.existing) {
+                                    reporter.report("Missing group entry: $child")
+                                }
+                                entry.children.add(child)
+                            } else if (lines.containsKey(child)) {
+                                toRemove.add(child)
+                                reporter.report("Found invalid group entry: $child")
+                            }
+                        }
+                    }
+                }
+                parent = inheritance[parent]?.superName
+            }
+        }
+        constructorGroups.values().each { entry -> entry.existing.findAll { it !in entry.children }.each{  reporter.report("Found invalid group entry: $it") } }
+
+        toRemove.each(lines.&remove)
+
+        return lines
+    }
+
+    private static List<String> joinBack(TreeMap<String, ATParser.Entry> lines, Map<String, InheritanceData> inheritance, IMappingFile mappings) {
+        final data = []
+        final remapComment = { ATParser.Entry entry ->
+            if (!mappings || !entry || !entry.desc) return null
+            final comment = entry.comment?.substring(1)?.trim()
+            final jsonCls = inheritance.get(entry.cls.replaceAll('\\.', '/'))
+            final mappingsClass = mappings?.getClass(jsonCls.name)
+            if (mappingsClass === null) return entry.comment
+            final idx = entry.desc.indexOf('(')
+
+            String mappedName = idx == -1
+                    ? mappingsClass.remapField(entry.desc)
+                    : mappingsClass.remapMethod(entry.desc.substring(0, idx), entry.desc.substring(idx))
+            if (!mappedName) return entry.comment
+            if (mappedName == '<init>')
+                mappedName = 'constructor'
+
+            if (comment?.startsWith(mappedName))
+                return '# ' + comment
+            if (comment && comment.indexOf(' ') !== -1) {
+                def split = comment.split(' - ').toList()
+                if (split[0].indexOf(' ') !== -1)
+                // The first string is more than one word, so append before it
+                    return "# ${mappedName} - ${comment}"
+                split.remove(0)
+                return "# ${mappedName} - ${String.join(' - ', split)}"
+            }
+            return '# ' + mappedName
+        }
+        lines.each { key, value ->
+            if (!value.group) {
+                def comment = remapComment.call(value)
+                data.add(value.modifier + ' ' + key + (comment ? ' ' + comment : ''))
+            } else {
+                data.add(('#group ' + value.modifier + ' ' + key + ' ' + (value.comment ?: '')).trim())
+                value.children.each {
+                    final line = value.modifier + ' ' + it
+                    final entry = ATParser.parseEntry(line)
+                    final comment = remapComment(entry)
+                    data.add(line + (comment ? ' ' + comment : ''))
+                }
+                data.add('#endgroup')
+            }
+        }
+        return data
+    }
+
+    static int accessStr(String access) {
+        if (access.endsWith('-f') || access.endsWith('+f')) return 4
+        switch (access.toLowerCase()) {
+            case 'public':    return 3
+            case 'protected': return 2
+            case 'default':   return 1
+            case 'private':   return 0
+            default:          return -1
+        }
+    }
+
+    static int accessLevel(int access) {
+        if ((access & Opcodes.ACC_PUBLIC)    !== 0) return 3
+        if ((access & Opcodes.ACC_PROTECTED) !== 0) return 2
+        if ((access & Opcodes.ACC_PRIVATE)   !== 0) return 0
+        return 1
+    }
+}
+
+@CompileStatic
+class ATParser {
+    static TreeMap<String, Entry> parse(List<String> lines, CheckTask.Reporter reporter) {
+        TreeMap<String, Entry> outLines = new TreeMap<>()
+        Entry group = null
+        for (final line : lines) {
+            if (line.isEmpty()) continue
+            if (line.startsWith('#group ')) {
+                final entry = parseEntry(line.substring(7))
+
+                if (entry.desc != '*' && entry.desc != '*()' && entry.desc != '<init>') {
+                    reporter.report("Invalid group: $line", false)
+                }
+
+                entry.group = true
+                entry.children = []
+                entry.existing = []
+
+                group = entry
+
+                if (outLines.containsKey(entry.key)) {
+                    reporter.report("Duplicate group: $line", false)
+                }
+
+                outLines[entry.key] = group
+            } else if (group !== null) {
+                if (line.startsWith('#endgroup')) {
+                    group = null
+                } else {
+                    final key = parseEntry(line).key
+                    group.existing.add(key)
+                }
+            } else if (line.startsWith('#endgroup')) {
+                reporter.report("Invalid group ending: $line", false)
+            } else if (line.startsWith('#')) {
+                //Nom
+            } else {
+                final entry = parseEntry(line)
+                if (outLines.containsKey(entry.key)) {
+                    reporter.report("Found duplicate: $line")
+                    continue
+                }
+                outLines[entry.key] = entry
+            }
+        }
+        return outLines
+    }
+
+    static Entry parseEntry(String line) {
+        final idx = line.indexOf('#')
+        final String comment = idx === -1 ? null : line.substring(idx)
+        if (idx !== -1) line = line.substring(0, idx - 1)
+        final data = (line.trim() + '     ').split(' ', -1)
+        new Entry(data[0], data[1], data[2], comment)
+    }
+
+    @TupleConstructor
+    static final class Entry {
+        String modifier, cls, desc, comment
+
+        Set<String> existing
+        TreeSet<String> children
+        boolean group = false
+
+        @Lazy
+        String key = {cls + (desc.isEmpty() ? '' : ' ' + desc)}()
+
+        Object getAt(String key) {
+            return getProperty(key)
+        }
+    }
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/checks/CheckExcs.groovy

@@ -0,0 +1,93 @@
+package net.minecraftforge.forge.tasks.checks
+
+import org.gradle.api.file.ConfigurableFileCollection
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.tasks.InputFile
+import org.gradle.api.tasks.InputFiles
+import org.objectweb.asm.ClassReader
+import org.objectweb.asm.ClassVisitor
+import org.objectweb.asm.MethodVisitor
+import org.objectweb.asm.Opcodes
+import org.objectweb.asm.Type
+
+import java.util.zip.ZipEntry
+import java.util.zip.ZipInputStream
+
+abstract class CheckExcs extends CheckTask {
+
+    @InputFile abstract RegularFileProperty getBinary()
+    @InputFiles abstract ConfigurableFileCollection getExcs()
+
+    @Override
+    void check(Reporter reporter, boolean fix) {
+        final Set<String> known = []
+        collectKnown(known)
+
+        excs.each { f ->
+            final lines = []
+            f.eachLine { line ->
+                def idx = line.indexOf('#')
+                if (idx == 0 || line.isEmpty()) {
+                    return
+                }
+
+                if (idx != -1) line = line.substring(0, idx - 1)
+
+                if (!line.contains('=')) {
+                    reporter.report("Invalid: $line")
+                    return
+                }
+
+                def (String key, String value) = line.split('=', 2)
+                if (!known.contains(key)) {
+                    reporter.report("Unknown: $line")
+                    return
+                }
+
+                String desc = key.split('\\.', 2)[1]
+                if (!desc.contains('(')) {
+                    reporter.report("Invalid: $line")
+                    return
+                }
+                desc = '(' + desc.split('\\(', 2)[1]
+
+                def (exceptions, String args) = value.contains('|') ? value.split('|', 2) : [value, '']
+
+                if (args.split(',').length !== Type.getArgumentTypes(desc).length) {
+                    reporter.report("Invalid: $line")
+                    return
+                }
+                lines.add(line)
+            }
+
+            if (fix) f.text = lines.sort().join('\n')
+        }
+    }
+
+    private void collectKnown(Collection<String> known) {
+        binary.get().asFile.withInputStream { i ->
+            new ZipInputStream(i).withCloseable { zin ->
+                final visitor = new ClassVisitor(Opcodes.ASM9) {
+                    private String cls
+                    @Override
+                    void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
+                        this.cls = name
+                    }
+
+                    @Override
+                    MethodVisitor visitMethod(int access, String name, String descriptor, String signature, String[] exceptions) {
+                        known.add(this.cls + '.' + name + descriptor)
+                        super.visitMethod(access, name, descriptor, signature, exceptions)
+                    }
+                }
+                ZipEntry zein
+                while ((zein = zin.nextEntry) !== null) {
+                    if (zein.name.endsWith('.class')) {
+                        ClassReader reader = new ClassReader(zin)
+                        reader.accept(visitor, ClassReader.SKIP_CODE | ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES)
+                    }
+                }
+            }
+        }
+    }
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/checks/CheckMode.groovy

@@ -0,0 +1,9 @@
+package net.minecraftforge.forge.tasks.checks
+
+import groovy.transform.CompileStatic
+
+@CompileStatic
+enum CheckMode {
+    CHECK,
+    FIX
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/checks/CheckPatches.groovy

@@ -0,0 +1,177 @@
+package net.minecraftforge.forge.tasks.checks
+
+import groovy.transform.CompileStatic
+import org.gradle.api.file.DirectoryProperty
+import org.gradle.api.provider.ListProperty
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.InputDirectory
+import org.gradle.api.tasks.Optional
+
+import java.nio.file.Files
+import java.nio.file.Path
+import java.util.regex.Pattern
+
+@CompileStatic
+abstract class CheckPatches extends CheckTask {
+
+    private static final Pattern HUNK_START_PATTERN = Pattern.compile('^@@ -[0-9,]* \\+[0-9,_]* @@$')
+    private static final Pattern WHITESPACE_PATTERN = Pattern.compile('^[+\\-]\\s*$')
+    private static final Pattern IMPORT_PATTERN = Pattern.compile('^[+\\-]\\s*import.*')
+    private static final Pattern FIELD_PATTERN = Pattern.compile('^[+\\-][\\s]*((public|protected|private)[\\s]*)?(static[\\s]*)?(final)?([^=;]*)(=.*)?;\\s*$')
+    private static final Pattern METHOD_PATTERN = Pattern.compile('^[+\\-][\\s]*((public|protected|private)[\\s]*)?(static[\\s]*)?(final)?([^(]*)[(]([^)]*)?[)]\\s*[{]\\s*$')
+    private static final Pattern CLASS_PATTERN = Pattern.compile('^[+\\-][\\s]*((public|protected|private)[\\s]*)?(static[\\s]*)?(final[\\s]*)?(class|interface)([^{]*)[{]\\s*$')
+    private static final Map<String, Integer> ACCESS_MAP = [private: 0, protected: 2, public: 3].tap { it.put(null, 1) }
+
+    @InputDirectory abstract DirectoryProperty getPatchDir()
+    @Input @Optional abstract ListProperty<String> getPatchesWithS2SArtifact()
+
+    @Override
+    void check(Reporter reporter, boolean fix) {
+        final patchDir = getPatchDir().get().asFile.toPath()
+        Files.walk(patchDir).withCloseable {
+            it.filter(Files.&isRegularFile).forEach { path ->
+                final String relativeName = patchDir.relativize(path).toString()
+                verifyPatch(path, reporter, fix, relativeName, patchesWithS2SArtifact.get().contains(relativeName.replace('\\', '/')))
+            }
+        }
+    }
+
+    void verifyPatch(Path patch, Reporter reporter, boolean fix, String patchPath, boolean hasS2SArtifact) {
+        final oldFixedErrors = reporter.fixed.size()
+
+        final lines = Files.readAllLines(patch)
+
+        int hunksStart = 0
+        boolean onlyWhiteSpace = false
+
+        final List<String> newLines = []
+
+        // First two lines are file name ++/-- and we do not care
+        newLines.add(lines[0] + '\n')
+        newLines.add(lines[1] + '\n')
+
+        int i
+        for (i = 2; i < lines.size(); ++i) {
+            def line = lines[i]
+            newLines.add(line + '\n')
+
+            if (HUNK_START_PATTERN.matcher(line).find()) {
+                if (onlyWhiteSpace) {
+                    if (!hasS2SArtifact)
+                        reporter.report("Patch contains only white space hunk starting at line ${hunksStart + 1}, file: $patchPath")
+                    int toRemove = i - hunksStart
+                    while (toRemove-- > 0)
+                        newLines.remove(newLines.size() - 1)
+                }
+                hunksStart = i
+                onlyWhiteSpace = true
+                continue
+            }
+
+            if (line.startsWithAny('+','-')) {
+                def prefixChange = false
+                def prevLine = lines[i - 1]
+
+                if (line.charAt(0) == (char)'+' && prevLine.charAt(0) == (char)'-') {
+                    def prevTrim = prevLine.substring(1).replaceAll("\\s", "")
+                    def currTrim = line.substring(1).replaceAll("\\s", "")
+
+                    if (prevTrim == currTrim) {
+                        prefixChange = true
+                    }
+
+                    def pMatcher = FIELD_PATTERN.matcher(prevLine)
+                    def cMatcher = FIELD_PATTERN.matcher(line)
+
+                    if (pMatcher.find() && cMatcher.find() &&
+                            pMatcher.group(6) == cMatcher.group(6) && // = ...
+                            pMatcher.group(5) == cMatcher.group(5) && // field name
+                            pMatcher.group(3) == cMatcher.group(3) && // static
+                            (ACCESS_MAP[pMatcher.group(2)] < ACCESS_MAP[cMatcher.group(2)] || pMatcher.group(4) != cMatcher.group(4))) {
+                        reporter.report("Patch contains access changes or final removal at line ${i + 1}, file: $patchPath", false)
+                    }
+
+                    pMatcher = METHOD_PATTERN.matcher(prevLine)
+                    cMatcher = METHOD_PATTERN.matcher(line)
+
+                    if (pMatcher.find() && cMatcher.find() &&
+                            pMatcher.group(6) == cMatcher.group(6) && // params
+                            pMatcher.group(5) == cMatcher.group(5) && // <T> void name
+                            pMatcher.group(3) == cMatcher.group(3) && // static
+                            (ACCESS_MAP[pMatcher.group(2)] < ACCESS_MAP[cMatcher.group(2)] || pMatcher.group(4) != cMatcher.group(4))) {
+                        reporter.report("Patch contains access changes or final removal at line ${i + 1}, file: $patchPath", false)
+                    }
+
+                    pMatcher = CLASS_PATTERN.matcher(prevLine)
+                    cMatcher = CLASS_PATTERN.matcher(line)
+
+                    if (pMatcher.find() && cMatcher.find() &&
+                            pMatcher.group(6) == cMatcher.group(6) && // ClassName<> extends ...
+                            pMatcher.group(5) == cMatcher.group(5) && // class | interface
+                            pMatcher.group(3) == cMatcher.group(3) && // static
+                            (ACCESS_MAP[pMatcher.group(2)] < ACCESS_MAP[cMatcher.group(2)] || pMatcher.group(4) != cMatcher.group(4))) {
+                        reporter.report("Patch contains access changes or final removal at line ${i + 1}, file: $patchPath", false)
+                    }
+                }
+
+                if (line.charAt(0) == (char)'-' && i + 1 < lines.size()) {
+                    final nextLine = lines[i + 1]
+                    if (nextLine.charAt(0) == (char)'+') {
+                        final nextTrim = nextLine.substring(1).replaceAll("\\s", "")
+                        final currTrim = line.substring(1).replaceAll("\\s", "")
+
+                        if (nextTrim == currTrim) {
+                            prefixChange = true
+                        }
+                    }
+                }
+
+                final isWhiteSpaceChange = WHITESPACE_PATTERN.matcher(line).find()
+
+                if (!prefixChange && !isWhiteSpaceChange) {
+                    onlyWhiteSpace = hasS2SArtifact && IMPORT_PATTERN.matcher(line).find()
+                } else if (isWhiteSpaceChange) {
+                    final prevLineChange = prevLine.startsWithAny('+','-')
+                    final nextLineChange = i + 1 < lines.size() && lines[i + 1].startsWithAny('+','-')
+
+                    if (!prevLineChange && !nextLineChange) {
+                        reporter.report("Patch contains white space change in valid hunk at line ${i + 1}, file: $patchPath", false)
+                    }
+                }
+
+                if (line.contains('\t')) {
+                    reporter.report("Patch contains tabs on line ${i + 1}, file: $patchPath")
+                    line = line.replaceAll('\t', '    ')
+                    newLines.remove(newLines.size() - 1)
+                    newLines.add(line + '\n')
+                }
+
+                if (IMPORT_PATTERN.matcher(line).find() && !hasS2SArtifact) {
+                    reporter.report("Patch contains import change on line ${i + 1}, file: $patchPath", false)
+                }
+            }
+        }
+
+        if (onlyWhiteSpace) {
+            if (!hasS2SArtifact)
+                reporter.report("Patch contains only white space hunk starting at line ${hunksStart + 1}, file: $patchPath")
+            def toRemove = i - hunksStart;
+            while (toRemove-- > 0)
+                newLines.remove(newLines.size() - 1)
+        }
+
+        if ((reporter.fixed.size() > oldFixedErrors && fix) || hasS2SArtifact) {
+            if (newLines.size() <= 2) {
+                logger.lifecycle("Patch is now empty removing, file: {}", patchPath)
+                Files.delete(patch)
+            }
+            else {
+                if (!hasS2SArtifact)
+                    logger.lifecycle("*** Updating patch file. Please run setup then genPatches again. ***")
+                Files.newBufferedWriter(patch).withCloseable {
+                    newLines.each { l -> it.write(l) }
+                }
+            }
+        }
+    }
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/checks/CheckSAS.groovy

@@ -0,0 +1,110 @@
+package net.minecraftforge.forge.tasks.checks
+
+import groovy.transform.CompileStatic
+import net.minecraftforge.forge.tasks.Annotatable
+import net.minecraftforge.forge.tasks.InheritanceData
+import org.gradle.api.file.ConfigurableFileCollection
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.tasks.InputFile
+import org.gradle.api.tasks.InputFiles
+
+@CompileStatic
+abstract class CheckSAS extends CheckTask {
+
+    @InputFile abstract RegularFileProperty getInheritance()
+    @InputFiles abstract ConfigurableFileCollection getSass()
+
+    @Override
+    void check(Reporter reporter, boolean fix) {
+        final inheritance = InheritanceData.parse(this.inheritance.get().asFile)
+
+        sass.each { f ->
+            final lines = []
+            f.eachLine { line ->
+                if (line[0] == '\t') return // Skip any tabbed lines, those are ones we add
+                final idx = line.indexOf('#')
+                if (idx == 0 || line.isEmpty()) {
+                    lines.add(line)
+                    return
+                }
+                def comment = idx == -1 ? null : line.substring(idx)
+                if (idx != -1) line = line.substring(0, idx - 1)
+                final spl = (line.trim().replace('(', ' (') + '     ').split(' ', -1)
+                def (String cls, String name, String desc) = [spl[0], spl[1], spl[2]]
+                cls = cls.replaceAll('\\.', '/')
+
+                if (inheritance[cls] === null) {
+                    reporter.report("Invalid: $line")
+                } else if (name.isEmpty()) { //Class SAS
+                    final toAdd = []
+                    final clsSided = isSided(inheritance[cls])
+                    boolean sided = clsSided
+
+                    /* TODO: MergeTool doesn't do fields
+                    if (json[cls]['fields'] != null) {
+                        for (entry in json[cls]['fields']) {
+                            if (isSided(entry.value)) {
+                                sided = true
+                                toAdd.add('\t' + cls + ' ' + entry.key)
+                            }
+						}
+                    } */
+
+                    final clsInh = inheritance[cls]
+                    if (clsInh.methods) {
+                        for (entry in clsInh.methods) {
+                            if (isSided(entry.value)) {
+                                sided = true
+                                toAdd.add('\t' + cls + ' ' + entry.key.replaceAll(' ', ''))
+                                findChildMethods(inheritance, cls, entry.key).each { lines.add('\t' + it) }
+                                findChildMethods(inheritance, cls, entry.key).each { println(line + ' -- ' + it) }
+                            } else if (clsSided) {
+                                findChildMethods(inheritance, cls, entry.key).each { lines.add('\t' + it) }
+                                findChildMethods(inheritance, cls, entry.key).each { println(line + ' -- ' + it) }
+                            }
+                        }
+                    }
+
+                    if (sided) {
+                        lines.add(cls + (comment == null ? '' : ' ' + comment))
+                        lines.addAll(toAdd.sort())
+                    } else {
+                        reporter.report("Invalid: $line")
+                    }
+
+                } else if (desc.isEmpty()) { // Fields
+                    /* TODO: MergeTool doesn't do fields
+                    if (json[cls]['fields'] != null && isSided(json[cls]['fields'][name]))
+                        lines.add(cls + ' ' + name + (comment == null ? '' : ' ' + comment))
+                    else */
+                    reporter.report("Invalid: $line")
+                } else { // Methods
+                    final clsInh = inheritance[cls]
+                    if (clsInh.methods === null || !isSided(clsInh.methods[name + ' ' + desc]))
+                        reporter.report("Invalid: $line")
+                    else {
+                        lines.add(cls + ' ' + name + desc + (comment == null ? '' : ' ' + comment))
+                        findChildMethods(inheritance, cls, name + ' ' + desc).each { println(line + ' -- ' + it) }
+                        findChildMethods(inheritance, cls, name + ' ' + desc).each { lines.add('\t' + it) }
+                    }
+                }
+            }
+
+            if (fix) f.text = lines.join('\n')
+        }
+    }
+
+    protected static isSided(Annotatable annotatable) {
+        if (annotatable === null) return false
+        for (ann in annotatable.annotations) {
+            if ('Lnet/minecraftforge/api/distmarker/OnlyIn;' == ann.desc)
+                return true
+        }
+        return false
+    }
+    
+    protected static findChildMethods(Map<String, InheritanceData> json, String cls, String desc) {
+        return json.values().findAll{ it.methods != null && it.methods[desc] != null && it.methods[desc].override == cls && isSided(it.methods[desc]) }
+                .collect { it.name + ' ' + desc.replace(' ', '') } as TreeSet
+    }
+}

buildSrc/src/main/groovy/net/minecraftforge/forge/tasks/checks/CheckTask.groovy

@@ -0,0 +1,109 @@
+package net.minecraftforge.forge.tasks.checks
+
+import groovy.transform.CompileStatic
+import net.minecraftforge.forge.tasks.Util
+import org.gradle.api.Action
+import org.gradle.api.DefaultTask
+import org.gradle.api.logging.LogLevel
+import org.gradle.api.provider.Property
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.TaskAction
+import org.gradle.api.tasks.TaskContainer
+import org.gradle.api.tasks.VerificationTask
+
+@CompileStatic
+abstract class CheckTask extends DefaultTask implements VerificationTask {
+    @Input
+    abstract Property<CheckMode> getMode()
+
+    private boolean ignoreFailures = false
+
+    @Input
+    @Override
+    boolean getIgnoreFailures() {
+        return ignoreFailures
+    }
+
+    @Override
+    void setIgnoreFailures(boolean ignoreFailures) {
+        this.ignoreFailures = ignoreFailures
+    }
+
+    @TaskAction
+    void run() {
+        Util.init()
+
+        final doFix = getMode().get() === CheckMode.FIX
+        final Reporter reporter = new Reporter(doFix)
+        check(reporter, doFix)
+        
+        if (reporter.messages) {
+            if (getMode().get() === CheckMode.CHECK) {
+                logger.error("Check task '{}' found errors:\n{}", name, reporter.messages.join('\n'))
+                if (!ignoreFailures) {
+                    throw new IllegalArgumentException("${reporter.messages.size()} errors were found!")
+                }
+            } else {
+                if (logger.isEnabled(LogLevel.DEBUG)) {
+                    logger.warn("Check task '{}' found {} errors and fixed {}:\n{}", name, reporter.messages.size(), reporter.fixed.size(), reporter.fixed.join('\n'))
+                } else {
+                    logger.warn("Check task '{}' found {} errors and fixed {}.", name, reporter.messages.size(), reporter.fixed.size())
+                }
+
+                if (reporter.notFixed) {
+                    logger.error('{} errors could not be fixed:\n{}', reporter.notFixed.size(), reporter.notFixed.join('\n'))
+                    if (!ignoreFailures) {
+                        throw new IllegalArgumentException("${reporter.notFixed.size()} errors which cannot be fixed were found!")
+                    }
+                }
+            }
+        }
+    }
+
+    abstract void check(Reporter reporter, boolean fix)
+
+    @CompileStatic
+    static final class Reporter {
+        final boolean trackFixed
+        Reporter(boolean trackFixed) {
+            this.trackFixed = trackFixed
+        }
+
+        public final List<String> messages = []
+
+        public final List<String> fixed = []
+        public final List<String> notFixed = []
+
+        void report(String message, boolean canBeFixed = true) {
+            messages.add(message)
+
+            if (trackFixed) {
+                if (canBeFixed) {
+                    fixed.add(message)
+                } else {
+                    notFixed.add(message)
+                }
+            }
+        }
+    }
+
+    static <T extends CheckTask> void registerTask(TaskContainer tasks, String taskName, @DelegatesTo.Target('type') Class<T> clazz,
+                                                   @DelegatesTo(genericTypeIndex = 0, target = 'type') Closure configuration) {
+        taskName = taskName.capitalize()
+        tasks.register("check$taskName", clazz) { CheckTask task ->
+            configuration.setDelegate((T) task)
+            configuration.call(task)
+            task.mode.set(CheckMode.CHECK)
+            task.group = 'checks'
+        }
+        tasks.named('checkAll').configure { it.dependsOn("check$taskName") }
+
+        tasks.register("checkAndFix$taskName", clazz) { CheckTask task ->
+            configuration.setDelegate((T) task)
+            configuration.call(task)
+            task.mode.set(CheckMode.FIX)
+            task.group = 'checks'
+        }
+        tasks.named('checkAllAndFix').configure { it.dependsOn("checkAndFix$taskName") }
+    }
+}

docs/CONTRIBUTING.md

@@ -15,8 +15,4 @@ Contributor License Agreement
 - You grant Forge a license to use your code contributed to the primary codebase (everything **not** under patches) in Forge, under the LGPLv2.1 license.
 - You assign copyright ownership of your contributions to the patches codebase (everything under patches) to Forge, where it will be licensed under the LGPLv2.1 license.
 
-Additionally, while 1.9.4 is being maintained, you will be asked to acknowledge these two additional clauses.
-- You grant Forge a license to use your code contributed to the primary codebase (everything **not** under patches) in Forge, under the MinecraftForge license.
-- You grant assign copyright ownership of your contributions to the patches codebase (everything under patches) to Forge, where it will be licensed under the MinecraftForge license.
-
 "Forge" is Forge Development LLC, a legally incorporated entity in Oregon, USA.

docs/README.md

@@ -1,17 +1,17 @@
-<img src="assets/Forge_logo.svg">
+![Forge Logo](assets/Forge_logo.svg)
 
 MinecraftForge
 =============
-[![Stable Release](https://img.shields.io/badge/dynamic/json?url=https://files.minecraftforge.net/maven/net/minecraftforge/forge/promotions_slim.json&label=Stable&prefix=1.15.2-&query=$.promos["1.15.2-recommended"]&color=brightgreen&logo=data:image/svg+xml;base64,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)](https://files.minecraftforge.net)
-[![Latest Release](https://img.shields.io/badge/dynamic/json?url=https://files.minecraftforge.net/maven/net/minecraftforge/forge/promotions_slim.json&label=Latest&prefix=1.15.2-&query=$.promos["1.15.2-latest"]&color=blue&logo=data:image/svg+xml;base64,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
-)](https://files.minecraftforge.net) [![Discord](https://img.shields.io/discord/313125603924639766.svg?color=%237289da&label=Discord&logo=discord&logoColor=%237289da)](https://discord.gg/UvedJ9m) [![Support](https://img.shields.io/badge/Patreon-Support-orange.svg?logo=Patreon)](https://www.patreon.com/LexManos) [![Merch](https://img.shields.io/badge/Flocker-Merch-blueviolet.svg)](https://forgedev.flocker.tv/)
+[![Stable Release](https://img.shields.io/badge/dynamic/json?url=https://files.minecraftforge.net/net/minecraftforge/forge/promotions_slim.json&label=Stable&prefix=1.17.1-&query=$.promos["1.17.1-recommended"]&color=brightgreen&logo=data:image/svg+xml;base64,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)](https://files.minecraftforge.net)
+[![Latest Release](https://img.shields.io/badge/dynamic/json?url=https://files.minecraftforge.net/net/minecraftforge/forge/promotions_slim.json&label=Latest&prefix=1.17.1-&query=$.promos["1.17.1-latest"]&color=blue&logo=data:image/svg+xml;base64,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
+)](https://files.minecraftforge.net) [![Discord](https://img.shields.io/discord/313125603924639766.svg?color=%237289da&label=Discord&logo=discord&logoColor=%237289da)](https://discord.gg/UvedJ9m) [![Support](https://img.shields.io/badge/Patreon-Support-orange.svg?logo=Patreon)](https://www.patreon.com/LexManos)
 
 Forge is a free, open-source modding API all of your favourite mods use!
 
-| Version  | Support |
+|    Version    |    Support    |
 | ------------- | ------------- |
-| 1.15.x  | Active  |
-| 1.14.x  | LTS  |
+|    1.17.x     |    Active     |
+|    1.16.x     |    LTS        |
 
 * [Download]
 * [Forum]
@@ -60,7 +60,7 @@ We require all contributors to acknowledge the [Forge Contributor
  signed it, you should be OK.
 
 #### Donate
-*Forge is a large project with many collaborators working on it around the clock. Forge is and will always remain free to use and modify. However, it costs money to run such a large project as this, so please consider [becoming a patron](https://www.patreon.com/LexManos) or buying some [cool merch](https://forgedev.flocker.tv/).*
+*Forge is a large project with many collaborators working on it around the clock. Forge is and will always remain free to use and modify. However, it costs money to run such a large project as this, so please consider [becoming a patron](https://www.patreon.com/LexManos).*
 
 [Download]: https://files.minecraftforge.net/
 [Forum]: https://www.minecraftforge.net/forum/

fmlcore/build.gradle

@@ -0,0 +1,64 @@
+plugins {
+    id 'com.github.ben-manes.versions'
+    id 'org.javamodularity.moduleplugin' version '1.8.3' apply false
+}
+apply plugin: 'java-library'
+apply plugin: 'jacoco'
+apply plugin: 'org.javamodularity.moduleplugin'
+
+dependencyUpdates.rejectVersionIf { isNonStable(it.candidate.version) }
+
+dependencies {
+    compileOnly('org.jetbrains:annotations:21.0.1')
+    implementation(project(':fmlloader'))
+    api('net.minecraftforge:eventbus:5.0.+')
+    implementation('commons-io:commons-io:2.5')
+}
+
+task sourcesJar(type: Jar) {
+    archiveClassifier = 'sources'
+    from sourceSets.main.allSource
+}
+
+ext {
+    MANIFESTS = [
+        '': [
+            'FMLModType': 'LIBRARY',
+            'Timestamp': new Date().format("yyyy-MM-dd'T'HH:mm:ssZ"),
+            'Git-Commit': GIT_INFO.abbreviatedId,
+            'Git-Branch': GIT_INFO.branch,
+            'Build-Number': "${System.getenv('BUILD_NUMBER')?:0}"
+        ] as LinkedHashMap,
+        'net/minecraftforge/fml/loading/': [
+            'Specification-Title':      'FMLLoader',
+            'Specification-Vendor':     'Forge Development LLC',
+            'Specification-Version':    '1',
+            'Implementation-Title':     'FML Loader',
+            'Implementation-Version':   '1.0',
+            'Implementation-Vendor':    'Forge'
+        ] as LinkedHashMap
+    ]
+}
+
+jar.doFirst {
+    MANIFESTS.each { pkg, values ->
+        if (pkg == '')
+            manifest.attributes(values)
+        else
+            manifest.attributes(values, pkg)
+    }
+}
+
+tasks.withType(JavaCompile) {
+    options.compilerArgs << '-Xlint:unchecked'
+}
+
+artifacts {
+    archives jar
+    archives sourcesJar
+}
+
+publishing.publications.mavenJava(MavenPublication) {
+    from components.java
+    artifact sourcesJar
+}

fmlcore/src/main/java/net/minecraftforge/fml/Bindings.java

@@ -0,0 +1,36 @@
+package net.minecraftforge.fml;
+
+import cpw.mods.modlauncher.util.ServiceLoaderUtils;
+import net.minecraftforge.eventbus.api.BusBuilder;
+import net.minecraftforge.eventbus.api.IEventBus;
+import net.minecraftforge.fml.config.IConfigEvent;
+import net.minecraftforge.fml.loading.FMLLoader;
+
+import java.util.ServiceLoader;
+import java.util.function.Supplier;
+
+public class Bindings {
+    private static final Bindings INSTANCE = new Bindings();
+
+    private final IBindingsProvider provider;
+
+    private Bindings() {
+        final var providers = ServiceLoaderUtils.streamServiceLoader(()->ServiceLoader.load(FMLLoader.getGameLayer(), IBindingsProvider.class), sce->{}).toList();
+        if (providers.size() != 1) {
+            throw new IllegalStateException("Could not find bindings provider");
+        }
+        this.provider = providers.get(0);
+    }
+
+    public static Supplier<IEventBus> getForgeBus() {
+        return INSTANCE.provider.getForgeBusSupplier();
+    }
+
+    public static Supplier<I18NParser> getMessageParser() {
+        return INSTANCE.provider.getMessageParser();
+    }
+
+    public static Supplier<IConfigEvent.ConfigConfig> getConfigConfiguration() {
+        return INSTANCE.provider.getConfigConfiguration();
+    }
+}

fmlcore/src/main/java/net/minecraftforge/fml/CrashReportCallables.java

@@ -0,0 +1,32 @@
+package net.minecraftforge.fml;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.function.Supplier;
+
+public class CrashReportCallables {
+    private static final List<ISystemReportExtender> crashCallables = Collections.synchronizedList(new ArrayList<>());
+
+    public static void registerCrashCallable(ISystemReportExtender callable)
+    {
+        crashCallables.add(callable);
+    }
+
+    public static void registerCrashCallable(String headerName, Supplier<String> reportGenerator) {
+        registerCrashCallable(new ISystemReportExtender() {
+            @Override
+            public String getLabel() {
+                return headerName;
+            }
+            @Override
+            public String get() {
+                return reportGenerator.get();
+            }
+        });
+    }
+
+    public static List<ISystemReportExtender> allCrashCallables() {
+        return List.copyOf(crashCallables);
+    }
+}

fmlcore/src/main/java/net/minecraftforge/fml/DeferredWorkQueue.java

@@ -0,0 +1,101 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2021.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.minecraftforge.fml;
+
+import static net.minecraftforge.fml.Logging.LOADING;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ConcurrentLinkedDeque;
+import java.util.concurrent.Executor;
+import java.util.concurrent.TimeUnit;
+import java.util.function.Supplier;
+
+import com.google.common.base.Stopwatch;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+/**
+ * Utility for running code on the main launch thread at the next available
+ * opportunity. There is no guaranteed order that work from various mods will be
+ * run, but your own work will be run sequentially.
+ * <p>
+ * <strong>Use of this class after startup is not possible.</strong> At that
+ * point, {@code ReentrantBlockableEventLoop} should be used instead.
+ * <p>
+ * Exceptions from tasks will be handled gracefully, causing a mod loading
+ * error. Tasks that take egregiously long times to run will be logged.
+ */
+public class DeferredWorkQueue
+{
+    private static final Logger LOGGER = LogManager.getLogger();
+
+    private static final Map<ModLoadingStage, DeferredWorkQueue> workQueues = new HashMap<>();
+
+    private final ConcurrentLinkedDeque<TaskInfo> tasks = new ConcurrentLinkedDeque<>();
+    private final ModLoadingStage modLoadingStage;
+
+    public DeferredWorkQueue(ModLoadingStage modLoadingStage) {
+        this.modLoadingStage = modLoadingStage;
+        workQueues.put(modLoadingStage, this);
+    }
+
+    @SuppressWarnings("OptionalUsedAsFieldOrParameterType")
+    public static Optional<DeferredWorkQueue> lookup(Optional<ModLoadingStage> parallelClass) {
+        return Optional.ofNullable(workQueues.get(parallelClass.orElse(null)));
+    }
+
+    public void runTasks() {
+        if (tasks.isEmpty()) return;
+        LOGGER.debug(LOADING, "Dispatching synchronous work for work queue {}: {} jobs", modLoadingStage, tasks.size());
+        Stopwatch timer = Stopwatch.createStarted();
+        tasks.forEach(t->makeRunnable(t, Runnable::run));
+        timer.stop();
+        LOGGER.debug(LOADING, "Synchronous work queue completed in {}", timer);
+    }
+
+    private static void makeRunnable(TaskInfo ti, Executor executor) {
+        executor.execute(() -> {
+            Stopwatch timer = Stopwatch.createStarted();
+            ModLoadingContext.get().setActiveContainer(ti.owner);
+            try {
+                ti.task.run();
+            } finally {
+                ModLoadingContext.get().setActiveContainer(null);
+            }
+            timer.stop();
+            if (timer.elapsed(TimeUnit.SECONDS) >= 1) {
+                LOGGER.warn(LOADING, "Mod '{}' took {} to run a deferred task.", ti.owner.getModId(), timer);
+            }
+        });
+    }
+
+    public CompletableFuture<Void> enqueueWork(final ModContainer modInfo, final Runnable work) {
+        return CompletableFuture.runAsync(work, r->tasks.add(new TaskInfo(modInfo, r)));
+    }
+
+    public <T> CompletableFuture<T> enqueueWork(final ModContainer modInfo, final Supplier<T> work) {
+        return CompletableFuture.supplyAsync(work, r->tasks.add(new TaskInfo(modInfo, r)));
+    }
+
+    record TaskInfo(ModContainer owner, Runnable task) {}
+}

fmlcore/src/main/java/net/minecraftforge/fml/DistExecutor.java

@@ -0,0 +1,276 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2021.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.minecraftforge.fml;
+
+import net.minecraftforge.api.distmarker.Dist;
+import net.minecraftforge.fml.loading.FMLEnvironment;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.io.Serializable;
+import java.lang.invoke.SerializedLambda;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.Objects;
+import java.util.concurrent.Callable;
+import java.util.function.Supplier;
+
+/**
+ * Use to execute code conditionally based on sidedness.
+ * <ul>
+ * <li>When you want to call something on one side and return a result {@link #safeCallWhenOn(Dist, Supplier)}</li>
+ * <li>When you want to call one thing on one side, another thing on the other and return a result {@link #safeRunForDist(Supplier, Supplier)}</li>
+ * <li>When you want to run something on one side {@link #safeRunWhenOn(Dist, Supplier)}</li>
+ * </ul>
+ */
+public final class DistExecutor
+{
+    private static final Logger LOGGER = LogManager.getLogger();
+    private DistExecutor() {}
+
+    /**
+     * Run the callable in the supplier only on the specified {@link Dist}.
+     * This method is NOT sided-safe and special care needs to be taken in code using this method that implicit class
+     * loading is not triggered by the Callable.
+     *
+     * This method can cause unexpected ClassNotFound exceptions.
+     *
+     * Use {@link #safeCallWhenOn(Dist, Supplier)} where possible.
+     *
+     * @param dist The dist to run on
+     * @param toRun A supplier of the callable to run (Supplier wrapper to ensure classloading only on the appropriate dist)
+     * @param <T> The return type from the callable
+     * @return The callable's result
+     * @deprecated use {@link #safeCallWhenOn(Dist, Supplier)} instead. This remains for advanced use cases.
+     */
+    @Deprecated
+    public static <T> T callWhenOn(Dist dist, Supplier<Callable<T>> toRun) {
+        return unsafeCallWhenOn(dist, toRun);
+    }
+
+    public static <T> T unsafeCallWhenOn(Dist dist, Supplier<Callable<T>> toRun) {
+        if (dist == FMLEnvironment.dist) {
+            try
+            {
+                return toRun.get().call();
+            }
+            catch (Exception e)
+            {
+                throw new RuntimeException(e);
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Call the SafeCallable when on the correct {@link Dist}.
+     *
+     * <strong>The lambda supplied here is required to be a method reference to a method defined in
+     * another class, otherwise an invalid SafeReferent error will be thrown</strong>
+     * @param dist the dist which this will run on
+     * @param toRun the SafeCallable to run and return the result from
+     * @param <T> The type of the SafeCallable
+     * @return the result of the SafeCallable or null if on the wrong side
+     */
+    public static <T> T safeCallWhenOn(Dist dist, Supplier<SafeCallable<T>> toRun) {
+        validateSafeReferent(toRun);
+        return callWhenOn(dist, toRun::get);
+    }
+
+    /**
+     * Runs the supplied Runnable on the speicified side. Same warnings apply as {@link #callWhenOn(Dist, Supplier)}.
+     *
+     * This method can cause unexpected ClassNotFound exceptions.
+     *
+     * @see #callWhenOn(Dist, Supplier)
+     * @param dist Dist to run this code on
+     * @param toRun The code to run
+     * @deprecated use {@link #safeRunWhenOn(Dist, Supplier)} where possible. Advanced uses only.
+     */
+    @Deprecated
+    public static void runWhenOn(Dist dist, Supplier<Runnable> toRun) {
+        unsafeRunWhenOn(dist, toRun);
+    }
+    /**
+     * Runs the supplied Runnable on the speicified side. Same warnings apply as {@link #unsafeCallWhenOn(Dist, Supplier)}.
+     *
+     * This method can cause unexpected ClassNotFoundException problems in common scenarios. Understand the pitfalls of
+     * the way the class verifier works to load classes before using this.
+     *
+     * Use {@link #safeRunWhenOn(Dist, Supplier)} if you can.
+     *
+     * @see #unsafeCallWhenOn(Dist, Supplier)
+     * @param dist Dist to run this code on
+     * @param toRun The code to run
+     */
+    public static void unsafeRunWhenOn(Dist dist, Supplier<Runnable> toRun) {
+        if (dist == FMLEnvironment.dist) {
+            toRun.get().run();
+        }
+    }
+
+    /**
+     * Call the supplied SafeRunnable when on the correct Dist.
+     * @param dist The dist to run on
+     * @param toRun The code to run
+     */
+    public static void safeRunWhenOn(Dist dist, Supplier<SafeRunnable> toRun) {
+        validateSafeReferent(toRun);
+        if (dist == FMLEnvironment.dist)  {
+            toRun.get().run();
+        }
+    }
+    /**
+     * Executes one of the two suppliers, based on which side is active.
+     *
+     * <p>
+     *     Example (replacement for old SidedProxy):<br/>
+     * {@code Proxy p = DistExecutor.runForDist(()->ClientProxy::new, ()->ServerProxy::new);}
+     *
+     * NOTE: the double supplier is required to avoid classloading the secondary target.
+     *
+     * @param clientTarget The supplier supplier to run when on the {@link Dist#CLIENT}
+     * @param serverTarget The supplier supplier to run when on the {@link Dist#DEDICATED_SERVER}
+     * @param <T> The common type to return
+     * @return The returned instance
+     * @deprecated Use {@link #safeRunForDist(Supplier, Supplier)}
+     */
+    @Deprecated
+    public static <T> T runForDist(Supplier<Supplier<T>> clientTarget, Supplier<Supplier<T>> serverTarget) {
+        return unsafeRunForDist(clientTarget, serverTarget);
+    }
+
+    /**
+     * Unsafe version of {@link #safeRunForDist(Supplier, Supplier)}. Use only when you know what you're doing
+     * and understand why the verifier can cause unexpected ClassNotFoundException crashes even when code is apparently
+     * not sided. Ensure you test both sides fully to be confident in using this.
+     *
+     * @param clientTarget The supplier supplier to run when on the {@link Dist#CLIENT}
+     * @param serverTarget The supplier supplier to run when on the {@link Dist#DEDICATED_SERVER}
+     * @param <T> The common type to return
+     * @return The returned instance
+     */
+    public static <T> T unsafeRunForDist(Supplier<Supplier<T>> clientTarget, Supplier<Supplier<T>> serverTarget) {
+        switch (FMLEnvironment.dist)
+        {
+            case CLIENT:
+                return clientTarget.get().get();
+            case DEDICATED_SERVER:
+                return serverTarget.get().get();
+            default:
+                throw new IllegalArgumentException("UNSIDED?");
+        }
+    }
+    /**
+     * Executes one of the two suppliers, based on which side is active.
+     *
+     * <p>
+     *     Example (replacement for old SidedProxy):<br/>
+     * {@code Proxy p = DistExecutor.safeRunForDist(()->ClientProxy::new, ()->ServerProxy::new);}
+     *
+     * NOTE: the double supplier is required to avoid classloading the secondary target.
+     *
+     * @param clientTarget The supplier supplier to run when on the {@link Dist#CLIENT}
+     * @param serverTarget The supplier supplier to run when on the {@link Dist#DEDICATED_SERVER}
+     * @param <T> The common type to return
+     * @return The returned instance
+     */
+    public static <T> T safeRunForDist(Supplier<SafeSupplier<T>> clientTarget, Supplier<SafeSupplier<T>> serverTarget) {
+        validateSafeReferent(clientTarget);
+        validateSafeReferent(serverTarget);
+        switch (FMLEnvironment.dist)
+        {
+            case CLIENT:
+                return clientTarget.get().get();
+            case DEDICATED_SERVER:
+                return serverTarget.get().get();
+            default:
+                throw new IllegalArgumentException("UNSIDED?");
+        }
+    }
+
+    /**
+     * A safe referent. This will assert that it is being called via a separated class method reference. This will
+     * avoid the common pitfalls of {@link #callWhenOn(Dist, Supplier)} above.
+     *
+     * SafeReferents assert that they are defined as a separate method outside the scope of the calling class.
+     *
+     * <strong>Implementations need to be defined in a separate class to the referring site, with appropriate
+     * visibility to be accessible at the callsite (generally, avoid private methods).</strong>
+     *
+     * <p>
+     * Valid:<br/>
+     *
+     * {@code DistExecutor.safeCallWhenOn(Dist.CLIENT, ()->AnotherClass::clientOnlyMethod);}
+     *
+     * <p>
+     * Invalid:<br/>
+     *
+     * {@code DistExecutor.safeCallWhenOn(Dist.CLIENT, ()->()->Minecraft.getInstance().world);}
+     */
+    public interface SafeReferent {}
+
+    /**
+     * SafeCallable version of {@link SafeReferent}.
+     * @see SafeReferent
+     * @param <T> The return type of the Callable
+     */
+    public interface SafeCallable<T> extends SafeReferent, Callable<T>, Serializable {}
+
+    /**
+     * SafeSupplier version of {@link SafeReferent}
+     * @param <T> The return type of the Supplier
+     */
+    public interface SafeSupplier<T> extends SafeReferent, Supplier<T>, Serializable {}
+
+    /**
+     * SafeRunnable version of {@link SafeReferent}
+     */
+    public interface SafeRunnable extends SafeReferent, Runnable, Serializable {}
+
+    private static final void validateSafeReferent(Supplier<? extends SafeReferent> safeReferentSupplier) {
+        if (FMLEnvironment.production) return;
+        final SafeReferent setter;
+        try {
+            setter = safeReferentSupplier.get();
+        } catch (Exception e) {
+            // Typically a class cast exception, just return out, expected.
+            return;
+        }
+
+        for (Class<?> cl = setter.getClass(); cl != null; cl = cl.getSuperclass()) {
+            try {
+                Method m = cl.getDeclaredMethod("writeReplace");
+                m.setAccessible(true);
+                Object replacement = m.invoke(setter);
+                if (!(replacement instanceof SerializedLambda))
+                    break;// custom interface implementation
+                SerializedLambda l = (SerializedLambda) replacement;
+                if (Objects.equals(l.getCapturingClass(), l.getImplClass())) {
+                    LOGGER.fatal("Detected unsafe referent usage, please view the code at {}",Thread.currentThread().getStackTrace()[3]);
+                    throw new RuntimeException("Unsafe Referent usage found in safe referent method");
+                }
+            } catch (NoSuchMethodException e) {
+            } catch (IllegalAccessException | InvocationTargetException e) {
+                break;
+            }
+        }
+    }
+}

fmlcore/src/main/java/net/minecraftforge/fml/I18NParser.java

@@ -0,0 +1,6 @@
+package net.minecraftforge.fml;
+
+public interface I18NParser {
+    String parseMessage(String i18nMessage, Object... args);
+    String stripControlCodes(String toStrip);
+}

fmlcore/src/main/java/net/minecraftforge/fml/IBindingsProvider.java

@@ -0,0 +1,12 @@
+package net.minecraftforge.fml;
+
+import net.minecraftforge.eventbus.api.IEventBus;
+import net.minecraftforge.fml.config.IConfigEvent;
+
+import java.util.function.Supplier;
+
+public interface IBindingsProvider {
+    Supplier<IEventBus> getForgeBusSupplier();
+    Supplier<I18NParser> getMessageParser();
+    Supplier<IConfigEvent.ConfigConfig> getConfigConfiguration();
+}

fmlcore/src/main/java/net/minecraftforge/fml/IExtensionPoint.java

@@ -0,0 +1,62 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2021.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.minecraftforge.fml;
+
+import java.util.function.BiPredicate;
+import java.util.function.Supplier;
+
+public interface IExtensionPoint<T extends Record>
+{
+    /**
+     * Compatibility display test for the mod.
+     * Used for displaying compatibility with remote servers with the same mod, and on disk saves.
+     *
+     * The supplier provides my "local" version for sending across the network or writing to disk
+     * The predicate tests the version from a remote instance or save for acceptability (Boolean is true for network, false for local save)
+     * and returns true if the version is compatible.
+     *
+     * <p>Return {@code net.minecraftforge.fmllegacy.network.FMLNetworkConstants#IGNORESERVERONLY} in the supplier, if you wish to be ignored
+     * as a server side only mod.</p>
+     * <p>Return true in the predicate for all values of the input string (when network boolean is true) if you are client side,
+     * and don't care about matching any potential server version.</p>
+     *
+     * <p>
+     * Examples: A server only mod
+     * </p>
+     * <pre>{@code
+     *     registerExtensionPoint(DISPLAYTEST, ()->Pair.of(
+     *      ()->FMLNetworkConstants.IGNORESERVERONLY, // ignore me, I'm a server only mod
+     *      (s,b)->true // i accept anything from the server or the save, if I'm asked
+     *     )
+     * }</pre>
+     *
+     * <p>
+     * Examples: A client only mod
+     * </p>
+     * <pre>{@code
+     *     registerExtensionPoint(DISPLAYTEST, ()->Pair.of(
+     *      ()->"anything. i don't care", // if i'm actually on the server, this string is sent but i'm a client only mod, so it won't be
+     *      (remoteversionstring,networkbool)->networkbool // i accept anything from the server, by returning true if it's asking about the server
+     *     )
+     * }</pre>
+     *
+     */
+    record DisplayTest(Supplier<String> suppliedVersion, BiPredicate<String, Boolean> remoteVersionTest) implements IExtensionPoint<DisplayTest> {}
+}

fmlcore/src/main/java/net/minecraftforge/fml/IModLoadingState.java

@@ -0,0 +1,25 @@
+package net.minecraftforge.fml;
+
+import net.minecraftforge.eventbus.api.Event;
+import net.minecraftforge.fml.event.IModBusEvent;
+
+import java.util.List;
+import java.util.Optional;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.Executor;
+import java.util.function.Consumer;
+import java.util.function.Function;
+
+public interface IModLoadingState {
+    String name();
+    String previous();
+    ModLoadingPhase phase();
+    Function<ModList, String> message();
+    Optional<Consumer<ModList>> inlineRunnable();
+
+    default <T extends Event & IModBusEvent> Optional<CompletableFuture<List<Throwable>>> buildTransition(final Executor syncExecutor, final Executor parallelExecutor) {
+        return buildTransition(syncExecutor, parallelExecutor, e->CompletableFuture.runAsync(()->{}, e), e->CompletableFuture.runAsync(()->{}, e));
+    }
+
+    <T extends Event & IModBusEvent> Optional<CompletableFuture<List<Throwable>>> buildTransition(Executor syncExecutor, Executor parallelExecutor, Function<Executor, CompletableFuture<Void>> preSyncTask, Function<Executor, CompletableFuture<Void>> postSyncTask);
+}

fmlcore/src/main/java/net/minecraftforge/fml/IModStateProvider.java

@@ -0,0 +1,7 @@
+package net.minecraftforge.fml;
+
+import java.util.List;
+
+public interface IModStateProvider {
+    List<IModLoadingState> getAllStates();
+}

fmlcore/src/main/java/net/minecraftforge/fml/IModStateTransition.java

@@ -0,0 +1,87 @@
+package net.minecraftforge.fml;
+
+import net.minecraftforge.eventbus.api.Event;
+import net.minecraftforge.fml.event.IModBusEvent;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.Executor;
+import java.util.function.BiFunction;
+import java.util.function.Function;
+import java.util.function.Supplier;
+import java.util.stream.Stream;
+
+@SuppressWarnings("unchecked")
+public interface IModStateTransition {
+    static IModStateTransition buildNoopTransition() {
+        return new NoopTransition();
+    }
+
+    default <T extends Event & IModBusEvent> CompletableFuture<List<Throwable>> build(Executor syncExecutor, Executor parallelExecutor, Function<Executor, CompletableFuture<Void>> preSyncTask, Function<Executor, CompletableFuture<Void>> postSyncTask) {
+        List<CompletableFuture<List<Throwable>>> cfs = new ArrayList<>();
+        this.eventFunctionStream().get()
+                .map(f->(EventGenerator<T>)f)
+                .reduce((head, tail)-> addCompletableFutureTaskForModDispatch(syncExecutor, parallelExecutor, cfs, head, ModLoadingStage::currentState, tail))
+                .ifPresent(last-> addCompletableFutureTaskForModDispatch(syncExecutor, parallelExecutor, cfs, last, nextModLoadingStage(), null));
+        final CompletableFuture<Void> preSyncTaskCF = preSyncTask.apply(syncExecutor);
+        final CompletableFuture<List<Throwable>> eventDispatchCF = ModList.gather(cfs).thenCompose(ModList::completableFutureFromExceptionList);
+        final CompletableFuture<List<Throwable>> postEventDispatchCF = preSyncTaskCF.thenComposeAsync(n -> eventDispatchCF, parallelExecutor).thenApply(r -> {
+            postSyncTask.apply(syncExecutor);
+            return r;
+        });
+        return this.finalActivityGenerator().apply(syncExecutor, postEventDispatchCF);
+    }
+
+    default BiFunction<ModLoadingStage, Throwable, ModLoadingStage> nextModLoadingStage() {
+        return ModLoadingStage::nextState;
+    }
+
+    private <T extends Event & IModBusEvent> EventGenerator<T> addCompletableFutureTaskForModDispatch(final Executor syncExecutor, final Executor parallelExecutor, final List<CompletableFuture<List<Throwable>>> completeableFutures, final EventGenerator<T> eventGenerator, BiFunction<ModLoadingStage, Throwable, ModLoadingStage> nextState, final EventGenerator<T> nextGenerator) {
+        completeableFutures.add(((BiFunction<Executor, EventGenerator<T>, CompletableFuture<List<Throwable>>>)preDispatchHook()).apply(threadSelector().apply(syncExecutor, parallelExecutor), eventGenerator));
+        completeableFutures.add(ModList.get().futureVisitor(eventGenerator, nextState).apply(threadSelector().apply(syncExecutor, parallelExecutor)));
+        completeableFutures.add(((BiFunction<Executor, EventGenerator<T>, CompletableFuture<List<Throwable>>>)postDispatchHook()).apply(threadSelector().apply(syncExecutor, parallelExecutor), eventGenerator));
+        return nextGenerator;
+    }
+
+    Supplier<Stream<EventGenerator<?>>> eventFunctionStream();
+    ThreadSelector threadSelector();
+    BiFunction<Executor, CompletableFuture<List<Throwable>>, CompletableFuture<List<Throwable>>> finalActivityGenerator();
+    BiFunction<Executor, ? extends EventGenerator<?>, CompletableFuture<List<Throwable>>> preDispatchHook();
+    BiFunction<Executor, ? extends EventGenerator<?>, CompletableFuture<List<Throwable>>> postDispatchHook();
+
+    interface EventGenerator<T extends Event & IModBusEvent> extends Function<ModContainer, T> {
+        static <FN extends Event & IModBusEvent> EventGenerator<FN> fromFunction(Function<ModContainer, FN> fn) {
+            return fn::apply;
+        }
+    }
+}
+
+record NoopTransition() implements IModStateTransition {
+
+    @Override
+    public Supplier<Stream<EventGenerator<?>>> eventFunctionStream() {
+        return Stream::of;
+    }
+
+    @Override
+    public ThreadSelector threadSelector() {
+        return ThreadSelector.SYNC;
+    }
+
+    @Override
+    public BiFunction<Executor, CompletableFuture<List<Throwable>>, CompletableFuture<List<Throwable>>> finalActivityGenerator() {
+        return (e, t) -> t.thenApplyAsync(Function.identity(), e);
+    }
+
+    @Override
+    public BiFunction<Executor, ? extends EventGenerator<?>, CompletableFuture<List<Throwable>>> preDispatchHook() {
+        return (t, f)-> CompletableFuture.completedFuture(Collections.emptyList());
+    }
+
+    @Override
+    public BiFunction<Executor, ? extends EventGenerator<?>, CompletableFuture<List<Throwable>>> postDispatchHook() {
+        return (t, f)-> CompletableFuture.completedFuture(Collections.emptyList());
+    }
+}

fmlcore/src/main/java/net/minecraftforge/fml/ISystemReportExtender.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -17,11 +17,11 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-package net.minecraftforge.fml.common;
+package net.minecraftforge.fml;
 
-import net.minecraft.crash.ICrashReportDetail;
+import java.util.function.Supplier;
 
-public interface ICrashCallable extends ICrashReportDetail<String>
+public interface ISystemReportExtender extends Supplier<String>
 {
     String getLabel();
 }

fmlcore/src/main/java/net/minecraftforge/fml/InterModComms.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -33,38 +33,32 @@ import java.util.stream.StreamSupport;
 
 public class InterModComms
 {
-    public static final class IMCMessage {
-        private final String modId;
-        private final String method;
-        private final String senderModId;
-        private final Supplier<?> thing;
-
-        IMCMessage(String senderModId, String modId, String method, Supplier<?> thing)
-        {
-            this.senderModId = senderModId;
-            this.modId = modId;
-            this.method = method;
-            this.thing = thing;
-        }
+    public record IMCMessage(String senderModId, String modId, String method, Supplier<?> messageSupplier) {
 
         /**
+         * Deprecated: use {@link #senderModId()}
          * @return The modid of the sender. This is supplied by the caller, or by the active mod container context.
          * Consider it unreliable.
          */
+        @Deprecated
         public final String getSenderModId() {
             return this.senderModId;
         }
 
         /**
+         * Deprecated: use {@link #modId()}
          * @return The modid being sent to.
          */
+        @Deprecated
         public final String getModId() {
             return this.modId;
         }
 
         /**
+         * Deprecated: use {@link #method()}
          * @return The method being sent to.
          */
+        @Deprecated
         public final String getMethod() {
             return this.method;
         }
@@ -72,10 +66,12 @@ public class InterModComms
         /**
          * @param <T> The type of the message.
          * @return A {@link Supplier} of the message.
+         * Use {@link #messageSupplier()}
          */
         @SuppressWarnings("unchecked")
+        @Deprecated
         public final <T> Supplier<T> getMessageSupplier() {
-            return (Supplier<T>)this.thing;
+            return (Supplier<T>) this.messageSupplier;
         }
     }
 

fmlcore/src/main/java/net/minecraftforge/fml/LoadingFailedException.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public

fmlcore/src/main/java/net/minecraftforge/fml/Logging.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -19,12 +19,8 @@
 
 package net.minecraftforge.fml;
 
-import org.apache.logging.log4j.Level;
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.Marker;
 import org.apache.logging.log4j.MarkerManager;
-import org.apache.logging.log4j.core.config.Configurator;
 
 public class Logging
 {
@@ -35,6 +31,7 @@ public class Logging
     public static final Marker SPLASH = MarkerManager.getMarker("SPLASH");
     public static final Marker CAPABILITIES = MarkerManager.getMarker("CAPABILITIES");
     public static final Marker MODELLOADING = MarkerManager.getMarker("MODELLOADING");
+    public static final Marker FORGEMOD = MarkerManager.getMarker("FORGEMOD").addParents(LOADING);
 
     // --log CORE:+DEBUG,SCAN:-OFF
     // forge log debug 5

fmlcore/src/main/java/net/minecraftforge/fml/LogicalSide.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public

fmlcore/src/main/java/net/minecraftforge/fml/ModContainer.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -20,18 +20,20 @@
 package net.minecraftforge.fml;
 
 import net.minecraftforge.eventbus.api.Event;
+import net.minecraftforge.fml.config.IConfigEvent;
 import net.minecraftforge.fml.config.ModConfig;
+import net.minecraftforge.fml.event.IModBusEvent;
 import net.minecraftforge.forgespi.language.IModInfo;
-import org.apache.commons.lang3.tuple.Pair;
 
-import java.util.Collections;
 import java.util.EnumMap;
 import java.util.HashMap;
 import java.util.IdentityHashMap;
-import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.Executor;
+import java.util.function.BiFunction;
 import java.util.function.Consumer;
 import java.util.function.Supplier;
 
@@ -55,11 +57,11 @@ public abstract class ModContainer
     protected final IModInfo modInfo;
     protected ModLoadingStage modLoadingStage;
     protected Supplier<?> contextExtension;
-    protected final Map<ModLoadingStage, Consumer<LifecycleEventProvider.LifecycleEvent>> triggerMap;
-    protected final Map<ExtensionPoint, Supplier<?>> extensionPoints = new IdentityHashMap<>();
+    protected final Map<ModLoadingStage, Runnable> activityMap = new HashMap<>();
+    protected final Map<Class<? extends IExtensionPoint<?>>, Supplier<?>> extensionPoints = new IdentityHashMap<>();
     protected final EnumMap<ModConfig.Type, ModConfig> configs = new EnumMap<>(ModConfig.Type.class);
     @SuppressWarnings("OptionalUsedAsFieldOrParameterType")
-    protected Optional<Consumer<ModConfig.ModConfigEvent>> configHandler = Optional.empty();
+    protected Optional<Consumer<IConfigEvent>> configHandler = Optional.empty();
 
     public ModContainer(IModInfo info)
     {
@@ -67,13 +69,22 @@ public abstract class ModContainer
         // TODO: Currently not reading namespace from configuration..
         this.namespace = this.modId;
         this.modInfo = info;
-        this.triggerMap = new HashMap<>();
         this.modLoadingStage = ModLoadingStage.CONSTRUCT;
         // default displaytest extension checks for version string match
-        registerExtensionPoint(ExtensionPoint.DISPLAYTEST, () -> Pair.of(()->this.modInfo.getVersion().toString(),
+        registerExtensionPoint(IExtensionPoint.DisplayTest.class, () -> new IExtensionPoint.DisplayTest(()->this.modInfo.getVersion().toString(),
                 (incoming, isNetwork)->Objects.equals(incoming, this.modInfo.getVersion().toString())));
     }
 
+    /**
+     * Errored container state, used for filtering. Does nothing.
+     */
+    ModContainer()
+    {
+        this.modLoadingStage = ModLoadingStage.ERROR;
+        modId = "BROKEN";
+        namespace = "BROKEN";
+        modInfo = null;
+    }
     /**
      * @return the modid for this mod
      */
@@ -98,43 +109,34 @@ public abstract class ModContainer
         return modLoadingStage;
     }
 
-    /**
-     * Transition the mod to this event if possible.
-     * @param event to transition to
-     */
-    public final void transitionState(LifecycleEventProvider.LifecycleEvent event, Consumer<List<ModLoadingException>> errorHandler)
-    {
-        if (modLoadingStage == event.fromStage())
-        {
-            try
-            {
-                ModLoadingContext.get().setActiveContainer(this, contextExtension.get());
-                triggerMap.getOrDefault(modLoadingStage, e->{}).accept(event);
-                modLoadingStage = event.toStage();
-                ModLoadingContext.get().setActiveContainer(null, null);
-            }
-            catch (ModLoadingException e)
-            {
-                modLoadingStage = ModLoadingStage.ERROR;
-                errorHandler.accept(Collections.singletonList(e));
-            }
-        }
+    public static <T extends Event & IModBusEvent> CompletableFuture<Void> buildTransitionHandler(
+            final ModContainer target,
+            final IModStateTransition.EventGenerator<T> eventGenerator,
+            final BiFunction<ModLoadingStage, Throwable, ModLoadingStage> stateChangeHandler,
+            final Executor executor) {
+        return CompletableFuture
+                .runAsync(() -> {
+                    ModLoadingContext.get().setActiveContainer(target);
+                    target.activityMap.getOrDefault(target.modLoadingStage, ()->{}).run();
+                    target.acceptEvent(eventGenerator.apply(target));
+                }, executor)
+                .whenComplete((mc, exception) -> {
+                    target.modLoadingStage = stateChangeHandler.apply(target.modLoadingStage, exception);
+                    ModLoadingContext.get().setActiveContainer(null);
+                });
     }
 
-    /**
-     * @return the modinfo used to create this mod instance
-     */
     public IModInfo getModInfo()
     {
         return modInfo;
     }
 
     @SuppressWarnings("unchecked")
-    public <T> Optional<T> getCustomExtension(ExtensionPoint<T> point) {
+    public <T extends Record> Optional<T> getCustomExtension(Class<? extends IExtensionPoint<T>> point) {
         return Optional.ofNullable((T)extensionPoints.getOrDefault(point,()-> null).get());
     }
 
-    public <T> void registerExtensionPoint(ExtensionPoint<T> point, Supplier<T> extension)
+    public <T extends Record & IExtensionPoint<T>> void registerExtensionPoint(Class<? extends IExtensionPoint<T>> point, Supplier<T> extension)
     {
         extensionPoints.put(point, extension);
     }
@@ -143,7 +145,7 @@ public abstract class ModContainer
        configs.put(modConfig.getType(), modConfig);
     }
 
-    public void dispatchConfigEvent(ModConfig.ModConfigEvent event) {
+    public void dispatchConfigEvent(IConfigEvent event) {
         configHandler.ifPresent(configHandler->configHandler.accept(event));
     }
 
@@ -164,5 +166,5 @@ public abstract class ModContainer
      * Accept an arbitrary event for processing by the mod. Probably posted to an event bus in the lower level container.
      * @param e Event to accept
      */
-    protected void acceptEvent(Event e) {}
+    protected <T extends Event & IModBusEvent> void acceptEvent(T e) {}
 }

fmlcore/src/main/java/net/minecraftforge/fml/ModList.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -19,30 +19,40 @@
 
 package net.minecraftforge.fml;
 
-import net.minecraftforge.fml.loading.FMLConfig;
+import net.minecraftforge.eventbus.api.Event;
+import net.minecraftforge.fml.event.IModBusEvent;
+import net.minecraftforge.forgespi.language.IModFileInfo;
+import net.minecraftforge.forgespi.language.IModInfo;
 import net.minecraftforge.forgespi.language.ModFileScanData;
-import net.minecraftforge.fml.loading.FMLLoader;
 import net.minecraftforge.fml.loading.moddiscovery.ModFile;
 import net.minecraftforge.fml.loading.moddiscovery.ModFileInfo;
 import net.minecraftforge.fml.loading.moddiscovery.ModInfo;
+import net.minecraftforge.forgespi.locating.IModFile;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
+import java.util.AbstractMap;
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
-import java.util.concurrent.*;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionException;
+import java.util.concurrent.CompletionStage;
+import java.util.concurrent.Executor;
+import java.util.concurrent.ForkJoinPool;
+import java.util.concurrent.ForkJoinWorkerThread;
 import java.util.function.BiConsumer;
+import java.util.function.BiFunction;
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-import static net.minecraftforge.fml.Logging.LOADING;
-
 /**
  * Master list of all mods - game-side version. This is classloaded in the game scope and
  * can dispatch game level events as a result.
@@ -51,12 +61,11 @@ public class ModList
 {
     private static Logger LOGGER = LogManager.getLogger();
     private static ModList INSTANCE;
-    private final List<ModFileInfo> modFiles;
-    private final List<ModInfo> sortedList;
+    private final List<IModFileInfo> modFiles;
+    private final List<IModInfo> sortedList;
     private final Map<String, ModFileInfo> fileById;
     private List<ModContainer> mods;
     private Map<String, ModContainer> indexedMods;
-    private ForkJoinPool modLoadingThreadPool;
     private List<ModFileScanData> modFileScanData;
 
     private ModList(final List<ModFile> modFiles, final List<ModInfo> sortedList)
@@ -65,23 +74,23 @@ public class ModList
         this.sortedList = sortedList.stream().
                 map(ModInfo.class::cast).
                 collect(Collectors.toList());
-        this.fileById = this.modFiles.stream().map(ModFileInfo::getMods).flatMap(Collection::stream).
+        this.fileById = this.modFiles.stream().map(IModFileInfo::getMods).flatMap(Collection::stream).
                 map(ModInfo.class::cast).
                 collect(Collectors.toMap(ModInfo::getModId, ModInfo::getOwningFile));
-        final int loadingThreadCount = FMLConfig.loadingThreadCount();
-        LOGGER.debug(LOADING, "Using {} threads for parallel mod-loading", loadingThreadCount);
-        modLoadingThreadPool = new ForkJoinPool(loadingThreadCount, ModList::newForkJoinWorkerThread, null, false);
-        CrashReportExtender.registerCrashCallable("Mod List", this::crashReport);
+        CrashReportCallables.registerCrashCallable("Mod List", this::crashReport);
     }
 
     private String getModContainerState(String modId) {
         return getModContainerById(modId).map(ModContainer::getCurrentState).map(Object::toString).orElse("NONE");
     }
 
-    private String fileToLine(ModFile mf) {
-        return mf.getFileName() + " " + mf.getModInfos().get(0).getDisplayName() + " " +
-                mf.getModInfos().stream().map(mi -> mi.getModId() + "@" + mi.getVersion() + " " +
-                getModContainerState(mi.getModId())).collect(Collectors.joining(", ", "{", "}"));
+    private String fileToLine(IModFile mf) {
+        return String.format("%-50.50s|%-30.30s|%-30.30s|%-20.20s|%-10.10s|Manifest: %s", mf.getFileName(),
+                mf.getModInfos().get(0).getDisplayName(),
+                mf.getModInfos().get(0).getModId(),
+                mf.getModInfos().get(0).getVersion(),
+                getModContainerState(mf.getModInfos().get(0).getModId()),
+                ((ModFileInfo)mf.getModFileInfo()).getCodeSigningFingerprint().orElse("NOSIGNATURE"));
     }
     private String crashReport() {
         return "\n"+applyForEachModFile(this::fileToLine).collect(Collectors.joining("\n\t\t", "\t\t", ""));
@@ -93,10 +102,6 @@ public class ModList
         return INSTANCE;
     }
 
-    static LifecycleEventProvider.EventHandler<LifecycleEventProvider.LifecycleEvent, Consumer<List<ModLoadingException>>, Executor, Runnable> inlineDispatcher = (event, errors, executor, ticker) -> ModList.get().dispatchSynchronousEvent(event, errors, executor, ticker);
-
-    static LifecycleEventProvider.EventHandler<LifecycleEventProvider.LifecycleEvent, Consumer<List<ModLoadingException>>, Executor, Runnable> parallelDispatcher = (event, errors, executor, ticker) -> ModList.get().dispatchParallelEvent(event, errors, executor, ticker);
-
     public static ModList get() {
         return INSTANCE;
     }
@@ -109,48 +114,56 @@ public class ModList
         return thread;
     }
 
-    public List<ModFileInfo> getModFiles()
+    public List<IModFileInfo> getModFiles()
     {
         return modFiles;
     }
 
-    public ModFileInfo getModFileById(String modid)
+    public IModFileInfo getModFileById(String modid)
     {
         return this.fileById.get(modid);
     }
 
-    private void dispatchSynchronousEvent(LifecycleEventProvider.LifecycleEvent lifecycleEvent, final Consumer<List<ModLoadingException>> errorHandler, final Executor executor, final Runnable ticker) {
-        LOGGER.debug(LOADING, "Dispatching synchronous event {}", lifecycleEvent);
-        executor.execute(ticker);
-        FMLLoader.getLanguageLoadingProvider().forEach(lp->lp.consumeLifecycleEvent(()->lifecycleEvent));
-        this.mods.stream().forEach(m->m.transitionState(lifecycleEvent, errorHandler));
-        FMLLoader.getLanguageLoadingProvider().forEach(lp->lp.consumeLifecycleEvent(()->lifecycleEvent));
+    <T extends Event & IModBusEvent> Function<Executor, CompletableFuture<List<Throwable>>> futureVisitor(
+            final IModStateTransition.EventGenerator<T> eventGenerator,
+            final BiFunction<ModLoadingStage, Throwable, ModLoadingStage> stateChange) {
+        return executor -> gather(
+                this.mods.stream()
+                .map(mod -> ModContainer.buildTransitionHandler(mod, eventGenerator, stateChange, executor))
+                .collect(Collectors.toList()))
+            .thenComposeAsync(ModList::completableFutureFromExceptionList, executor);
     }
-    private void dispatchParallelEvent(LifecycleEventProvider.LifecycleEvent lifecycleEvent, final Consumer<List<ModLoadingException>> errorHandler, final Executor executor, final Runnable ticker) {
-        LOGGER.debug(LOADING, "Dispatching parallel event {}", lifecycleEvent);
-        FMLLoader.getLanguageLoadingProvider().forEach(lp->lp.consumeLifecycleEvent(()->lifecycleEvent));
-        DeferredWorkQueue.clear();
-        try
-        {
-            final ForkJoinTask<?> parallelTask = modLoadingThreadPool.submit(() -> this.mods.parallelStream().forEach(m -> m.transitionState(lifecycleEvent, errorHandler)));
-            while (ticker != null && !parallelTask.isDone()) {
-                executor.execute(ticker);
-            }
-            parallelTask.get();
+    static CompletionStage<List<Throwable>> completableFutureFromExceptionList(List<? extends Map.Entry<?, Throwable>> t) {
+        if (t.stream().noneMatch(e->e.getValue()!=null)) {
+            return CompletableFuture.completedFuture(Collections.emptyList());
+        } else {
+            final List<Throwable> throwables = t.stream().filter(e -> e.getValue() != null).map(Map.Entry::getValue).collect(Collectors.toList());
+            CompletableFuture<List<Throwable>> cf = new CompletableFuture<>();
+            final RuntimeException accumulator = new RuntimeException();
+            cf.completeExceptionally(accumulator);
+            throwables.forEach(exception -> {
+                if (exception instanceof CompletionException) {
+                    exception = exception.getCause();
+                }
+                if (exception.getSuppressed().length!=0) {
+                    Arrays.stream(exception.getSuppressed()).forEach(accumulator::addSuppressed);
+                } else {
+                    accumulator.addSuppressed(exception);
+                }
+            });
+            return cf;
         }
-        catch (InterruptedException | ExecutionException e)
-        {
-            LOGGER.error(LOADING, "Encountered an exception during parallel processing - sleeping 10 seconds to wait for jobs to finish", e);
-            errorHandler.accept(Collections.singletonList(new UncaughtModLoadingException(lifecycleEvent.fromStage(), e)));
-            modLoadingThreadPool.awaitQuiescence(10, TimeUnit.SECONDS);
-            if (!modLoadingThreadPool.isQuiescent()) {
-                LOGGER.fatal(LOADING, "The parallel pool has failed to quiesce correctly, forcing a shutdown. There is something really wrong here");
-                modLoadingThreadPool.shutdownNow();
-                throw new RuntimeException("Forge played \"STOP IT NOW MODS!\" - it was \"NOT VERY EFFECTIVE\"");
-            }
-        }
-        DeferredWorkQueue.runTasks(lifecycleEvent.fromStage(), errorHandler);
-        FMLLoader.getLanguageLoadingProvider().forEach(lp->lp.consumeLifecycleEvent(()->lifecycleEvent));
+    }
+
+    static <V> CompletableFuture<List<Map.Entry<V, Throwable>>> gather(List<? extends CompletableFuture<? extends V>> futures) {
+        List<Map.Entry<V, Throwable>> list = new ArrayList<>(futures.size());
+        CompletableFuture<?>[] results = new CompletableFuture[futures.size()];
+        futures.forEach(future -> {
+            int i = list.size();
+            list.add(null);
+            results[i] = future.whenComplete((result, exception) -> list.set(i, new AbstractMap.SimpleImmutableEntry<>(result, exception)));
+        });
+        return CompletableFuture.allOf(results).handle((r, th)->null).thenApply(res -> list);
     }
 
     void setLoadedMods(final List<ModContainer> modContainers)
@@ -175,7 +188,7 @@ public class ModList
         return mods.stream().filter(mc -> mc.getMod() == obj).findFirst();
     }
 
-    public List<ModInfo> getMods()
+    public List<IModInfo> getMods()
     {
         return this.sortedList;
     }
@@ -195,23 +208,24 @@ public class ModList
         if (modFileScanData == null)
         {
             modFileScanData = this.sortedList.stream().
-                    map(ModInfo::getOwningFile).
+                    map(IModInfo::getOwningFile).
                     filter(Objects::nonNull).
-                    map(ModFileInfo::getFile).
-                    map(ModFile::getScanResult).
+                    map(IModFileInfo::getFile).
+                    distinct().
+                    map(IModFile::getScanResult).
                     collect(Collectors.toList());
         }
         return modFileScanData;
 
     }
 
-    public void forEachModFile(Consumer<ModFile> fileConsumer)
+    public void forEachModFile(Consumer<IModFile> fileConsumer)
     {
-        modFiles.stream().map(ModFileInfo::getFile).forEach(fileConsumer);
+        modFiles.stream().map(IModFileInfo::getFile).forEach(fileConsumer);
     }
 
-    public <T> Stream<T> applyForEachModFile(Function<ModFile, T> function) {
-        return modFiles.stream().map(ModFileInfo::getFile).map(function);
+    public <T> Stream<T> applyForEachModFile(Function<IModFile, T> function) {
+        return modFiles.stream().map(IModFileInfo::getFile).map(function);
     }
 
     public void forEachModContainer(BiConsumer<String, ModContainer> modContainerConsumer) {

fmlcore/src/main/java/net/minecraftforge/fml/ModLoader.java

@@ -0,0 +1,333 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2021.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.minecraftforge.fml;
+
+import com.google.common.collect.ImmutableList;
+import net.minecraftforge.eventbus.api.Event;
+import net.minecraftforge.fml.event.IModBusEvent;
+import net.minecraftforge.fml.loading.FMLLoader;
+import net.minecraftforge.fml.loading.LoadingModList;
+import net.minecraftforge.fml.loading.moddiscovery.InvalidModIdentifier;
+import net.minecraftforge.fml.loading.moddiscovery.ModFile;
+import net.minecraftforge.fml.loading.moddiscovery.ModFileInfo;
+import net.minecraftforge.fml.loading.progress.StartupMessageManager;
+import net.minecraftforge.forgespi.language.IModInfo;
+import net.minecraftforge.forgespi.language.IModLanguageProvider;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionException;
+import java.util.concurrent.Executor;
+import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+import static net.minecraftforge.fml.Logging.CORE;
+import static net.minecraftforge.fml.Logging.LOADING;
+
+/**
+ * Loads mods.
+ *
+ * Dispatch cycle is seen in {@code #loadMods()} and {@code #finishMods()}
+ *
+ * Overall sequence for loadMods is:
+ * <dl>
+ *     <dt>CONSTRUCT</dt>
+ *     <dd>Constructs the mod instance. Mods can typically setup basic environment such as Event listeners
+ *     and Configuration specifications here.</dd>
+ *     <dt>Automated dispatches</dt>
+ *     <dd>Dispatches automated elements : {@code net.minecraftforge.fml.common.Mod.EventBusSubscriber},
+ *     {@code net.minecraftforge.event.RegistryEvent}, {@code net.minecraftforge.common.capabilities.CapabilityInject}
+ *     and others</dd>
+ *     <dt>CONFIG_LOAD</dt>
+ *     <dd>Dispatches ConfigLoadEvent to mods</dd>
+ *     <dt>COMMON_SETUP</dt>
+ *     <dd>Dispatches {@code net.minecraftforge.fml.event.lifecycle.FMLCommonSetupEvent} to mods</dd>
+ *     <dt>SIDED_SETUP</dt>
+ *     <dd>Dispatches {@code net.minecraftforge.fml.event.lifecycle.FMLClientSetupEvent} or
+ *     {@code net.minecraftforge.fml.event.lifecycle.FMLDedicatedServerSetupEvent} to mods</dd>
+ * </dl>
+ *
+ * Overall sequence for finishMods is:
+ * <dl>
+ *     <dt>ENQUEUE_IMC</dt>
+ *     <dd>Dispatches {@code net.minecraftforge.fml.event.lifecycle.InterModEnqueueEvent} to mods,
+ *     for enqueuing {@link InterModComms} messages for other mods to receive subsequently</dd>
+ *     <dt>PROCESS_IMC</dt>
+ *     <dd>Dispatches {@code net.minecraftforge.fml.event.lifecycle.InterModProcessEvent} to mods,
+ *     for processing {@link InterModComms} messages received from other mods prior to this event</dd>
+ *     <dt>COMPLETE</dt>
+ *     <dd>Dispatches {@code net.minecraftforge.fml.event.lifecycle.FMLLoadCompleteEvent} to mods,
+ *     and completes the mod loading sequence.</dd>
+ * </dl>
+ */
+public class ModLoader
+{
+    private static final Logger LOGGER = LogManager.getLogger();
+    private static ModLoader INSTANCE;
+    private final LoadingModList loadingModList;
+
+    private final List<ModLoadingException> loadingExceptions;
+    private final List<ModLoadingWarning> loadingWarnings;
+    private final ModStateManager stateManager;
+    private boolean loadingStateValid;
+    @SuppressWarnings("OptionalUsedAsFieldOrParameterType")
+    private final Optional<Consumer<String>> statusConsumer = StartupMessageManager.modLoaderConsumer();
+    private ModList modList;
+
+    private ModLoader()
+    {
+        INSTANCE = this;
+        this.loadingModList = FMLLoader.getLoadingModList();
+        this.loadingExceptions = FMLLoader.getLoadingModList().getErrors().stream()
+                .flatMap(ModLoadingException::fromEarlyException)
+                .collect(Collectors.toList());
+        this.loadingWarnings = FMLLoader.getLoadingModList().getBrokenFiles().stream()
+                .map(file -> new ModLoadingWarning(null, ModLoadingStage.VALIDATE, InvalidModIdentifier.identifyJarProblem(file.getFilePath()).orElse("fml.modloading.brokenfile"), file.getFileName()))
+                .collect(Collectors.toList());
+        FMLLoader.getLoadingModList().getModFiles().stream()
+                .filter(ModFileInfo::missingLicense) //Search for files with missing licenses
+                .filter(modFileInfo -> modFileInfo.getMods().stream().noneMatch(thisModInfo -> this.loadingExceptions.stream().map(ModLoadingException::getModInfo).anyMatch(otherInfo -> otherInfo == thisModInfo))) //Ignore files where any other mod already encountered an error
+                .map(modFileInfo -> new ModLoadingException(null, ModLoadingStage.VALIDATE, "fml.modloading.missinglicense", null, modFileInfo.getFile()))
+                .forEach(this.loadingExceptions::add);
+        this.stateManager = new ModStateManager();
+        CrashReportCallables.registerCrashCallable("ModLauncher", FMLLoader::getLauncherInfo);
+        CrashReportCallables.registerCrashCallable("ModLauncher launch target", FMLLoader::launcherHandlerName);
+        CrashReportCallables.registerCrashCallable("ModLauncher naming", FMLLoader::getNaming);
+        CrashReportCallables.registerCrashCallable("ModLauncher services", this::computeModLauncherServiceList);
+        CrashReportCallables.registerCrashCallable("FML Language Providers", this::computeLanguageList);
+    }
+
+    private String computeLanguageList() {
+        return "\n"+FMLLoader.getLanguageLoadingProvider().applyForEach(lp->lp.name() +"@"+ lp.getClass().getPackage().getImplementationVersion()).collect(Collectors.joining("\n\t\t", "\t\t", ""));
+    }
+
+    private String computeModLauncherServiceList() {
+        final List<Map<String, String>> mods = FMLLoader.modLauncherModList();
+        return "\n"+mods.stream().map(mod->mod.getOrDefault("file","nofile")+
+                " "+mod.getOrDefault("name", "missing")+
+                " "+mod.getOrDefault("type","NOTYPE")+
+                " "+mod.getOrDefault("description", "")).
+                collect(Collectors.joining("\n\t\t","\t\t",""));
+    }
+
+    public static ModLoader get()
+    {
+        return INSTANCE == null ? INSTANCE = new ModLoader() : INSTANCE;
+    }
+
+    /**
+     * Run on the primary starting thread by ClientModLoader and ServerModLoader
+     * @param syncExecutor An executor to run tasks on the main thread
+     * @param parallelExecutor An executor to run tasks on a parallel loading thread pool
+     * @param periodicTask Optional periodic task to perform on the main thread while other activities run
+     */
+    public void gatherAndInitializeMods(final ModWorkManager.DrivenExecutor syncExecutor, final Executor parallelExecutor, final Runnable periodicTask) {
+        loadingStateValid = true;
+        statusConsumer.ifPresent(c->c.accept("Waiting for scan to complete"));
+        FMLLoader.backgroundScanHandler.waitForScanToComplete(periodicTask);
+        statusConsumer.ifPresent(c->c.accept("Loading mods"));
+        final ModList modList = ModList.of(loadingModList.getModFiles().stream().map(ModFileInfo::getFile).toList(),
+                loadingModList.getMods());
+        if (!this.loadingExceptions.isEmpty()) {
+            LOGGER.fatal(CORE, "Error during pre-loading phase", loadingExceptions.get(0));
+            modList.setLoadedMods(Collections.emptyList());
+            loadingStateValid = false;
+            throw new LoadingFailedException(loadingExceptions);
+        }
+        statusConsumer.ifPresent(c->c.accept("Building Mod List"));
+        final List<ModContainer> modContainers = loadingModList.getModFiles().stream()
+                .map(ModFileInfo::getFile)
+                .map(this::buildMods)
+                .<ModContainer>mapMulti(Iterable::forEach)
+                .toList();
+        if (!loadingExceptions.isEmpty()) {
+            LOGGER.fatal(CORE, "Failed to initialize mod containers", loadingExceptions.get(0));
+            modList.setLoadedMods(Collections.emptyList());
+            loadingStateValid = false;
+            throw new LoadingFailedException(loadingExceptions);
+        }
+        modList.setLoadedMods(modContainers);
+        this.modList = modList;
+        statusConsumer.ifPresent(c->c.accept("Dispatching gathering events"));
+        stateManager.getStates(ModLoadingPhase.GATHER).forEach(mls->dispatchAndHandleError(mls, syncExecutor, parallelExecutor, periodicTask));
+        statusConsumer.ifPresent(c->c.accept("Gathering phase complete"));
+    }
+
+    public void loadMods(final ModWorkManager.DrivenExecutor syncExecutor, final Executor parallelExecutor, final Runnable periodicTask) {
+        statusConsumer.ifPresent(c->c.accept("Performing load phase"));
+        stateManager.getStates(ModLoadingPhase.LOAD).forEach(mls->dispatchAndHandleError(mls, syncExecutor, parallelExecutor, periodicTask));
+        statusConsumer.ifPresent(c->c.accept("Mod setup complete"));
+    }
+
+    public void finishMods(final ModWorkManager.DrivenExecutor syncExecutor, final Executor parallelExecutor, final Runnable periodicTask) {
+        statusConsumer.ifPresent(c->c.accept("Performing completion phase"));
+        stateManager.getStates(ModLoadingPhase.COMPLETE).forEach(mls->dispatchAndHandleError(mls, syncExecutor, parallelExecutor, periodicTask));
+        statusConsumer.ifPresent(c->c.accept(String.format("Mod loading complete - %d mods loaded", this.modList.size())));
+    }
+
+    private void dispatchAndHandleError(IModLoadingState state, ModWorkManager.DrivenExecutor syncExecutor, Executor parallelExecutor, final Runnable ticker) {
+        if (!isLoadingStateValid()) {
+            LOGGER.error("Cowardly refusing to process mod state change request from {}", state);
+            return;
+        }
+        statusConsumer.ifPresent(c->c.accept(state.message().apply(this.modList)));
+        state.inlineRunnable().ifPresent(a->a.accept(this.modList));
+        state.buildTransition(syncExecutor, parallelExecutor).ifPresent(t->waitForTransition(state, syncExecutor, ticker, t));
+    }
+
+    private void dispatchAndHandleError(IModLoadingState state, ModWorkManager.DrivenExecutor syncExecutor, Executor parallelExecutor, final Runnable ticker, Function<Executor, CompletableFuture<Void>> preSyncTask, Function<Executor, CompletableFuture<Void>> postSyncTask) {
+        if (!isLoadingStateValid()) {
+            LOGGER.error("Cowardly refusing to process mod state change request from {}", state);
+            return;
+        }
+        statusConsumer.ifPresent(c->c.accept(state.message().apply(this.modList)));
+        state.inlineRunnable().ifPresent(a->a.accept(this.modList));
+        state.buildTransition(syncExecutor, parallelExecutor, preSyncTask, postSyncTask).ifPresent(t->waitForTransition(state, syncExecutor, ticker, t));
+    }
+
+    private void waitForTransition(final IModLoadingState state, final ModWorkManager.DrivenExecutor syncExecutor, final Runnable ticker, final CompletableFuture<List<Throwable>> transition) {
+        while (!transition.isDone()) {
+            syncExecutor.drive(ticker);
+        }
+        try {
+            transition.join();
+        } catch (CompletionException e) {
+            loadingStateValid = false;
+            Throwable t = e.getCause();
+            final List<Throwable> notModLoading = Arrays.stream(t.getSuppressed())
+                    .filter(obj -> !(obj instanceof ModLoadingException))
+                    .collect(Collectors.toList());
+            if (!notModLoading.isEmpty()) {
+                LOGGER.fatal("Encountered non-modloading exceptions!", e);
+                throw e;
+            }
+
+            final List<ModLoadingException> modLoadingExceptions = Arrays.stream(t.getSuppressed())
+                    .filter(ModLoadingException.class::isInstance)
+                    .map(ModLoadingException.class::cast)
+                    .collect(Collectors.toList());
+            LOGGER.fatal(LOADING,"Failed to complete lifecycle event {}, {} errors found", state.name(), modLoadingExceptions.size());
+            throw new LoadingFailedException(modLoadingExceptions);
+        }
+    }
+
+    private List<ModContainer> buildMods(final ModFile modFile)
+    {
+        final Map<String, IModInfo> modInfoMap = modFile.getModFileInfo().getMods().stream().collect(Collectors.toMap(IModInfo::getModId, Function.identity()));
+
+        LOGGER.trace(LOADING, "ModContainer is {}", ModContainer.class.getClassLoader());
+        final List<ModContainer> containers = modFile.getScanResult().getTargets()
+                .entrySet()
+                .stream()
+                .map(e -> buildModContainerFromTOML(modFile, modInfoMap, e))
+                .filter(Objects::nonNull)
+                .collect(Collectors.toList());
+        if (containers.size() != modInfoMap.size()) {
+            LOGGER.fatal(LOADING,"File {} constructed {} mods: {}, but had {} mods specified: {}",
+                    modFile.getFilePath(),
+                    containers.size(), containers.stream().map(c -> c != null ? c.getModId() : "(null)").sorted().collect(Collectors.toList()),
+                    modInfoMap.size(), modInfoMap.values().stream().map(IModInfo::getModId).sorted().collect(Collectors.toList()));
+            loadingExceptions.add(new ModLoadingException(null, ModLoadingStage.CONSTRUCT, "fml.modloading.missingclasses", null, modFile.getFilePath()));
+        }
+        // remove errored mod containers
+        return containers.stream().filter(mc -> mc.modLoadingStage != ModLoadingStage.ERROR).collect(Collectors.toList());
+    }
+
+    private ModContainer buildModContainerFromTOML(final ModFile modFile, final Map<String, IModInfo> modInfoMap, final Map.Entry<String, ? extends IModLanguageProvider.IModLanguageLoader> idToProviderEntry) {
+        try {
+            final String modId = idToProviderEntry.getKey();
+            final IModLanguageProvider.IModLanguageLoader languageLoader = idToProviderEntry.getValue();
+            IModInfo info = Optional.ofNullable(modInfoMap.get(modId)).
+                    // throw a missing metadata error if there is no matching modid in the modInfoMap from the mods.toml file
+                    orElseThrow(()->new ModLoadingException(null, ModLoadingStage.CONSTRUCT, "fml.modloading.missingmetadata", null, modId));
+            return languageLoader.loadMod(info, modFile.getScanResult(), FMLLoader.getGameLayer());
+        } catch (ModLoadingException mle) {
+            // exceptions are caught and added to the error list for later handling
+            loadingExceptions.add(mle);
+            // return an errored container instance here, because we tried and failed building a container.
+            return new ErroredModContainer();
+        }
+    }
+
+    /**
+     * @return If the current mod loading state is valid. Use if you interact with vanilla systems directly during loading
+     * and don't want to cause extraneous crashes due to trying to do things that aren't possible in a "broken load"
+     */
+    public static boolean isLoadingStateValid() {
+        return get().loadingStateValid;
+    }
+
+    public <T extends Event & IModBusEvent> void runEventGenerator(Function<ModContainer, T> generator) {
+        if (!loadingStateValid) {
+            LOGGER.error("Cowardly refusing to send event generator to a broken mod state");
+            return;
+        }
+        ModList.get().forEachModContainer((id, mc) -> mc.acceptEvent(generator.apply(mc)));
+    }
+
+    public <T extends Event & IModBusEvent> void postEvent(T e) {
+        if (!loadingStateValid) {
+            LOGGER.error("Cowardly refusing to send event {} to a broken mod state", e.getClass().getName());
+            return;
+        }
+        ModList.get().forEachModContainer((id, mc) -> mc.acceptEvent(e));
+    }
+
+    public List<ModLoadingWarning> getWarnings()
+    {
+        return ImmutableList.copyOf(this.loadingWarnings);
+    }
+
+    public void addWarning(ModLoadingWarning warning)
+    {
+        this.loadingWarnings.add(warning);
+    }
+
+    private static boolean runningDataGen = false;
+
+    public static boolean isDataGenRunning () {
+        return runningDataGen;
+    }
+
+    private static class ErroredModContainer extends ModContainer {
+        public ErroredModContainer() {
+            super();
+        }
+
+        @Override
+        public boolean matches(final Object mod) {
+            return false;
+        }
+
+        @Override
+        public Object getMod() {
+            return null;
+        }
+    }
+}

fmlcore/src/main/java/net/minecraftforge/fml/ModLoadingContext.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -19,15 +19,16 @@
 
 package net.minecraftforge.fml;
 
-import net.minecraftforge.common.ForgeConfigSpec;
+import net.minecraftforge.fml.config.IConfigSpec;
 import net.minecraftforge.fml.config.ModConfig;
 
 import java.util.function.Supplier;
 
 public class ModLoadingContext
 {
-    private static ThreadLocal<ModLoadingContext> context = ThreadLocal.withInitial(ModLoadingContext::new);
+    private static final ThreadLocal<ModLoadingContext> context = ThreadLocal.withInitial(ModLoadingContext::new);
     private Object languageExtension;
+    private ModLoadingStage stage;
 
     public static ModLoadingContext get() {
         return context.get();
@@ -35,9 +36,9 @@ public class ModLoadingContext
 
     private ModContainer activeContainer;
 
-    public void setActiveContainer(final ModContainer container, final Object languageExtension) {
+    public void setActiveContainer(final ModContainer container) {
         this.activeContainer = container;
-        this.languageExtension = languageExtension;
+        this.languageExtension = container == null ? null : container.contextExtension.get();
     }
 
     public ModContainer getActiveContainer() {
@@ -49,20 +50,20 @@ public class ModLoadingContext
     }
 
     /**
-     * Register an {@link ExtensionPoint} with the mod container.
+     * Register an {@link IExtensionPoint} with the mod container.
      * @param point The extension point to register
      * @param extension An extension operator
      * @param <T> The type signature of the extension operator
      */
-    public <T> void registerExtensionPoint(ExtensionPoint<T> point, Supplier<T> extension) {
+    public <T extends Record & IExtensionPoint<T>> void registerExtensionPoint(Class<? extends IExtensionPoint<T>> point, Supplier<T> extension) {
         getActiveContainer().registerExtensionPoint(point, extension);
     }
 
-    public void registerConfig(ModConfig.Type type, ForgeConfigSpec spec) {
+    public void registerConfig(ModConfig.Type type, IConfigSpec<?> spec) {
         getActiveContainer().addConfig(new ModConfig(type, spec, getActiveContainer()));
     }
 
-    public void registerConfig(ModConfig.Type type, ForgeConfigSpec spec, String fileName) {
+    public void registerConfig(ModConfig.Type type, IConfigSpec<?> spec, String fileName) {
         getActiveContainer().addConfig(new ModConfig(type, spec, getActiveContainer(), fileName));
     }
 

fmlcore/src/main/java/net/minecraftforge/fml/ModLoadingException.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -32,6 +32,7 @@ import java.util.stream.Stream;
  */
 public class ModLoadingException extends RuntimeException
 {
+    private static final long serialVersionUID = 2048947398536935507L;
     /**
      * Mod Info for mod with issue
      */
@@ -60,7 +61,7 @@ public class ModLoadingException extends RuntimeException
     }
 
     static Stream<ModLoadingException> fromEarlyException(final EarlyLoadingException e) {
-        return e.getAllData().stream().map(ed->new ModLoadingException(null, ModLoadingStage.VALIDATE, ed.getI18message(), e.getCause(), ed.getArgs()));
+        return e.getAllData().stream().map(ed->new ModLoadingException(ed.getModInfo(), ModLoadingStage.VALIDATE, ed.getI18message(), e.getCause(), ed.getArgs()));
     }
 
     public String getI18NMessage() {
@@ -72,11 +73,18 @@ public class ModLoadingException extends RuntimeException
     }
 
     public String formatToString() {
-        return ForgeI18n.parseMessage(i18nMessage, Streams.concat(Stream.of(modInfo, errorStage, getCause()), context.stream()).toArray());
+        return Bindings.getMessageParser().get().parseMessage(i18nMessage, Streams.concat(Stream.of(modInfo, errorStage, getCause()), context.stream()).toArray());
     }
 
     @Override
     public String getMessage() {
         return formatToString();
     }
+
+    public IModInfo getModInfo() {
+        return modInfo;
+    }
+    public String getCleanMessage() {
+        return Bindings.getMessageParser().get().stripControlCodes(formatToString());
+    }
 }

fmlcore/src/main/java/net/minecraftforge/fml/ModLoadingPhase.java

@@ -0,0 +1,9 @@
+package net.minecraftforge.fml;
+
+public enum ModLoadingPhase {
+    ERROR, // Special state for error handling
+    GATHER,
+    LOAD,
+    COMPLETE,
+    DONE;
+}

fmlcore/src/main/java/net/minecraftforge/fml/ModLoadingStage.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -17,26 +17,35 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-package net.minecraftforge.fml.network;
+package net.minecraftforge.fml;
 
-import java.util.function.Function;
-
-public enum ConnectionType
+public enum ModLoadingStage
 {
-    MODDED(s->Integer.valueOf(s.substring(FMLNetworkConstants.FMLNETMARKER.length()))), VANILLA(s->0);
+    ERROR,
+    VALIDATE,
+    CONSTRUCT,
+    COMMON_SETUP,
+    SIDED_SETUP,
+    ENQUEUE_IMC,
+    PROCESS_IMC,
+    COMPLETE,
+    DONE;
 
-    private final Function<String, Integer> versionExtractor;
+    private final DeferredWorkQueue deferredWorkQueue;
 
-    ConnectionType(Function<String, Integer> versionExtractor) {
-        this.versionExtractor = versionExtractor;
+    ModLoadingStage() {
+        deferredWorkQueue = new DeferredWorkQueue(this);
     }
 
-    public static ConnectionType forVersionFlag(String vers)
-    {
-        return vers.startsWith(FMLNetworkConstants.FMLNETMARKER) ? MODDED : VANILLA;
+    ModLoadingStage nextState(Throwable exception) {
+        return exception != null ? ERROR : values()[this.ordinal()+1];
     }
 
-    public int getFMLVersionNumber(final String fmlVersion) {
-        return versionExtractor.apply(fmlVersion);
+    public ModLoadingStage currentState(Throwable exception) {
+        return exception != null ? ERROR : this;
+    }
+
+    public DeferredWorkQueue getDeferredWorkQueue() {
+        return deferredWorkQueue;
     }
 }

fmlcore/src/main/java/net/minecraftforge/fml/ModLoadingState.java

@@ -0,0 +1,33 @@
+package net.minecraftforge.fml;
+
+import net.minecraftforge.eventbus.api.Event;
+import net.minecraftforge.fml.event.IModBusEvent;
+
+import java.util.List;
+import java.util.Optional;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.Executor;
+import java.util.function.Consumer;
+import java.util.function.Function;
+
+public record ModLoadingState(String name, String previous, Function<ModList, String> message, ModLoadingPhase phase, Optional<Consumer<ModList>> inlineRunnable, Optional<IModStateTransition> transition) implements IModLoadingState {
+    @Override
+    public <T extends Event & IModBusEvent> Optional<CompletableFuture<List<Throwable>>> buildTransition(final Executor syncExecutor, final Executor parallelExecutor, Function<Executor, CompletableFuture<Void>> preSyncTask, Function<Executor, CompletableFuture<Void>> postSyncTask) {
+        return transition.map(t->t.build(syncExecutor, parallelExecutor, preSyncTask, postSyncTask));
+    }
+
+    public static ModLoadingState empty(final String name, final String previous, final ModLoadingPhase phase) {
+        return new ModLoadingState(name, previous, ml->"", phase, Optional.empty(), Optional.empty());
+    }
+
+    public static ModLoadingState withTransition(final String name, final String previous, final ModLoadingPhase phase, IModStateTransition transition) {
+        return new ModLoadingState(name, previous, ml->"Processing transition "+name, phase, Optional.empty(), Optional.of(transition));
+    }
+
+    public static ModLoadingState withTransition(final String name, final String previous, final Function<ModList, String> message, final ModLoadingPhase phase, IModStateTransition transition) {
+        return new ModLoadingState(name, previous, message, phase, Optional.empty(), Optional.of(transition));
+    }
+    public static ModLoadingState withInline(final String name, final String previous, final ModLoadingPhase phase, Consumer<ModList> inline) {
+        return new ModLoadingState(name, previous, ml->"Processing work "+name, phase, Optional.of(inline), Optional.empty());
+    }
+}

fmlcore/src/main/java/net/minecraftforge/fml/ModLoadingWarning.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -55,6 +55,6 @@ public class ModLoadingWarning
     }
 
     public String formatToString() {
-        return ForgeI18n.parseMessage(i18nMessage, Streams.concat(Stream.of(modInfo, warningStage), context.stream()).toArray());
+        return Bindings.getMessageParser().get().parseMessage(i18nMessage, Streams.concat(Stream.of(modInfo, warningStage), context.stream()).toArray());
     }
 }

fmlcore/src/main/java/net/minecraftforge/fml/ModStateManager.java

@@ -0,0 +1,38 @@
+package net.minecraftforge.fml;
+
+import com.google.common.graph.GraphBuilder;
+import com.google.common.graph.MutableGraph;
+import cpw.mods.modlauncher.util.ServiceLoaderUtils;
+import net.minecraftforge.fml.loading.FMLLoader;
+import net.minecraftforge.fml.loading.toposort.TopologicalSort;
+
+import java.util.*;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+@SuppressWarnings("UnstableApiUsage")
+public class ModStateManager {
+    static ModStateManager INSTANCE;
+    private final EnumMap<ModLoadingPhase, List<IModLoadingState>> stateMap;
+
+    public ModStateManager() {
+        INSTANCE = this;
+        final var sp = ServiceLoader.load(FMLLoader.getGameLayer(), IModStateProvider.class);
+        this.stateMap = ServiceLoaderUtils.streamWithErrorHandling(sp, sce->{})
+                .map(IModStateProvider::getAllStates)
+                .<IModLoadingState>mapMulti(Iterable::forEach)
+                .collect(Collectors.groupingBy(IModLoadingState::phase, ()->new EnumMap<>(ModLoadingPhase.class), Collectors.toUnmodifiableList()));
+    }
+
+    public List<IModLoadingState> getStates(final ModLoadingPhase phase) {
+        var nodes = stateMap.get(phase);
+        var lookup = nodes.stream().collect(Collectors.toMap(IModLoadingState::name, Function.identity()));
+
+        var graph = GraphBuilder.directed().allowsSelfLoops(false).<IModLoadingState>build();
+        var dummy = ModLoadingState.empty("", "", phase);
+        nodes.forEach(graph::addNode);
+        graph.addNode(dummy);
+        nodes.forEach(n->graph.putEdge(lookup.getOrDefault(n.previous(), dummy), n));
+        return TopologicalSort.topologicalSort(graph, Comparator.comparingInt(nodes::indexOf)).stream().filter(st->st!=dummy).toList();
+    }
+}

fmlcore/src/main/java/net/minecraftforge/fml/ModWorkManager.java

@@ -0,0 +1,125 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2021.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.minecraftforge.fml;
+
+import net.minecraftforge.fml.loading.FMLConfig;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.util.concurrent.*;
+import java.util.concurrent.locks.LockSupport;
+
+import static net.minecraftforge.fml.Logging.LOADING;
+
+public class ModWorkManager {
+    private static final Logger LOGGER = LogManager.getLogger();
+    private static final long PARK_TIME = TimeUnit.MILLISECONDS.toNanos(1);
+    public interface DrivenExecutor extends Executor {
+        boolean selfDriven();
+        boolean driveOne();
+
+        default void drive(Runnable ticker) {
+            if (!selfDriven()) {
+                while (driveOne()) {
+                    ticker.run();
+                }
+            } else {
+                // park for a bit so other threads can schedule
+                LockSupport.parkNanos(PARK_TIME);
+            }
+        }
+    }
+    private static class SyncExecutor implements DrivenExecutor {
+        private ConcurrentLinkedDeque<Runnable> tasks = new ConcurrentLinkedDeque<>();
+
+        @Override
+        public boolean driveOne() {
+            final Runnable task = tasks.pollFirst();
+            if (task != null) {
+                task.run();
+            }
+            return task != null;
+        }
+
+        @Override
+        public boolean selfDriven() {
+            return false;
+        }
+
+        @Override
+        public void execute(final Runnable command) {
+            tasks.addLast(command);
+        }
+    }
+
+    private static class WrappingExecutor implements DrivenExecutor {
+        private final Executor wrapped;
+
+        public WrappingExecutor(final Executor executor) {
+            this.wrapped = executor;
+        }
+
+        @Override
+        public boolean selfDriven() {
+            return true;
+        }
+
+        @Override
+        public boolean driveOne() {
+            return false;
+        }
+
+        @Override
+        public void execute(final Runnable command) {
+            wrapped.execute(command);
+        }
+    }
+
+    private static SyncExecutor syncExecutor;
+
+    public static DrivenExecutor syncExecutor() {
+        if (syncExecutor == null)
+            syncExecutor = new SyncExecutor();
+        return syncExecutor;
+    }
+
+    public static DrivenExecutor wrappedExecutor(Executor executor) {
+        return new WrappingExecutor(executor);
+    }
+
+    private static ForkJoinPool parallelThreadPool;
+    public static Executor parallelExecutor() {
+        if (parallelThreadPool == null) {
+            final int loadingThreadCount = FMLConfig.loadingThreadCount();
+            LOGGER.debug(LOADING, "Using {} threads for parallel mod-loading", loadingThreadCount);
+            parallelThreadPool = new ForkJoinPool(loadingThreadCount, ModWorkManager::newForkJoinWorkerThread, null, false);
+        }
+        return parallelThreadPool;
+    }
+
+    private static ForkJoinWorkerThread newForkJoinWorkerThread(ForkJoinPool pool) {
+        ForkJoinWorkerThread thread = ForkJoinPool.defaultForkJoinWorkerThreadFactory.newThread(pool);
+        thread.setName("modloading-worker-" + thread.getPoolIndex());
+        // The default sets it to the SystemClassloader, so copy the current one.
+        thread.setContextClassLoader(Thread.currentThread().getContextClassLoader());
+        return thread;
+    }
+
+}

fmlcore/src/main/java/net/minecraftforge/fml/OptionalMod.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public

fmlcore/src/main/java/net/minecraftforge/fml/StartupMessageManager.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -19,8 +19,19 @@
 
 package net.minecraftforge.fml;
 
+import java.util.Optional;
+import java.util.function.Consumer;
+
 public class StartupMessageManager {
     public static void addModMessage(final String message) {
         net.minecraftforge.fml.loading.progress.StartupMessageManager.addModMessage(message);
     }
+
+    public static Optional<Consumer<String>> modLoaderConsumer() {
+        return net.minecraftforge.fml.loading.progress.StartupMessageManager.modLoaderConsumer();
+    }
+
+    public static Optional<Consumer<String>> mcLoaderConsumer() {
+        return net.minecraftforge.fml.loading.progress.StartupMessageManager.mcLoaderConsumer();
+    }
 }

fmlcore/src/main/java/net/minecraftforge/fml/ThreadSelector.java

@@ -0,0 +1,20 @@
+package net.minecraftforge.fml;
+
+import java.util.concurrent.Executor;
+import java.util.function.BinaryOperator;
+
+public enum ThreadSelector implements BinaryOperator<Executor> {
+    SYNC((sync, parallel) -> sync),
+    PARALLEL((sync, parallel) -> parallel);
+
+    private final BinaryOperator<Executor> selector;
+
+    ThreadSelector(final BinaryOperator<Executor> selector) {
+        this.selector = selector;
+    }
+
+    @Override
+    public Executor apply(final Executor sync, final Executor parallel) {
+        return this.selector.apply(sync, parallel);
+    }
+}

fmlcore/src/main/java/net/minecraftforge/fml/VersionChecker.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -19,48 +19,34 @@
 
 package net.minecraftforge.fml;
 
-import com.google.common.io.ByteStreams;
 import com.google.gson.Gson;
-import net.minecraftforge.common.ForgeConfig;
 import net.minecraftforge.fml.loading.FMLConfig;
-import net.minecraftforge.fml.loading.moddiscovery.ModInfo;
+import net.minecraftforge.fml.loading.FMLLoader;
 import net.minecraftforge.forgespi.language.IModInfo;
-import net.minecraftforge.versions.mcp.MCPVersion;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apache.maven.artifact.versioning.ComparableVersion;
+
+import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStream;
-import java.net.HttpURLConnection;
+import java.io.InputStreamReader;
+import java.net.URISyntaxException;
 import java.net.URL;
-import java.net.URLConnection;
-import java.nio.charset.StandardCharsets;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.LinkedHashMap;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-
-
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import java.io.IOException;
-import java.io.InputStream;
-import java.net.HttpURLConnection;
-import java.net.URL;
-import java.net.URLConnection;
-import java.nio.charset.StandardCharsets;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.stream.Collectors;
+import java.util.zip.GZIPInputStream;
 
 import static net.minecraftforge.fml.VersionChecker.Status.*;
 
@@ -68,6 +54,7 @@ public class VersionChecker
 {
     private static final Logger LOGGER = LogManager.getLogger();
     private static final int MAX_HTTP_REDIRECTS = Integer.getInteger("http.maxRedirects", 20);
+    private static final int HTTP_TIMEOUT_SECS = Integer.getInteger("http.timeoutSecs", 15);
 
     public enum Status
     {
@@ -121,30 +108,14 @@ public class VersionChecker
 
     }
 
-    public static class CheckResult
-    {
-        @Nonnull
-        public final Status status;
-        @Nullable
-        public final ComparableVersion target;
-        @Nullable
-        public final Map<ComparableVersion, String> changes;
-        @Nullable
-        public final String url;
-
-        private CheckResult(@Nonnull Status status, @Nullable ComparableVersion target, @Nullable Map<ComparableVersion, String> changes, @Nullable String url)
-        {
-            this.status = status;
-            this.target = target;
-            this.changes = changes == null ? Collections.<ComparableVersion, String>emptyMap() : Collections.unmodifiableMap(changes);
-            this.url = url;
-        }
-    }
+    public record CheckResult(VersionChecker.Status status, ComparableVersion target, Map<ComparableVersion, String> changes, String url) {}
 
     public static void startVersionCheck()
     {
         new Thread("Forge Version Check")
         {
+            private HttpClient client;
+
             @Override
             public void run()
             {
@@ -154,44 +125,50 @@ public class VersionChecker
                     return;
                 }
 
+                client = HttpClient.newBuilder().connectTimeout(Duration.ofSeconds(HTTP_TIMEOUT_SECS)).build();
                 gatherMods().forEach(this::process);
             }
 
             /**
-             * Opens stream for given URL while following redirects
+             * Returns the response body as a String for the given URL while following redirects
              */
-            private InputStream openUrlStream(URL url) throws IOException
-            {
+            private String openUrlString(URL url) throws IOException, URISyntaxException, InterruptedException {
                 URL currentUrl = url;
                 for (int redirects = 0; redirects < MAX_HTTP_REDIRECTS; redirects++)
                 {
-                    URLConnection c = currentUrl.openConnection();
-                    if (c instanceof HttpURLConnection)
+                    var request = HttpRequest.newBuilder()
+                            .uri(currentUrl.toURI())
+                            .timeout(Duration.ofSeconds(HTTP_TIMEOUT_SECS))
+                            .setHeader("Accept-Encoding", "gzip")
+                            .GET()
+                            .build();
+
+                    final HttpResponse<InputStream> response = client.send(request, HttpResponse.BodyHandlers.ofInputStream());
+
+                    int responseCode = response.statusCode();
+                    if (responseCode >= 300 && responseCode <= 399)
                     {
-                        HttpURLConnection huc = (HttpURLConnection) c;
-                        huc.setInstanceFollowRedirects(false);
-                        int responseCode = huc.getResponseCode();
-                        if (responseCode >= 300 && responseCode <= 399)
-                        {
-                            try
-                            {
-                                String loc = huc.getHeaderField("Location");
-                                currentUrl = new URL(currentUrl, loc);
-                                continue;
-                            }
-                            finally
-                            {
-                                huc.disconnect();
-                            }
-                        }
+                        String newLocation = response.headers().firstValue("Location")
+                                .orElseThrow(() -> new IOException("Got a 3xx response code but Location header was null while trying to fetch " + url));
+                        currentUrl = new URL(currentUrl, newLocation);
+                        continue;
                     }
 
-                    return c.getInputStream();
+                    final boolean isGzipEncoded = response.headers().firstValue("Content-Encoding").orElse("").equals("gzip");
+
+                    final String bodyStr;
+                    try (InputStream inStream = isGzipEncoded ? new GZIPInputStream(response.body()) : response.body())
+                    {
+                        try (var bufferedReader = new BufferedReader(new InputStreamReader(inStream)))
+                        {
+                            bodyStr = bufferedReader.lines().collect(Collectors.joining("\n"));
+                        }
+                    }
+                    return bodyStr;
                 }
                 throw new IOException("Too many redirects while trying to fetch " + url);
             }
 
-            @SuppressWarnings("UnstableApiUsage")
             private void process(IModInfo mod)
             {
                 Status status = PENDING;
@@ -200,12 +177,11 @@ public class VersionChecker
                 String display_url = null;
                 try
                 {
-                    URL url = mod.getUpdateURL();
+                    if (mod.getUpdateURL().isEmpty()) return;
+                    URL url = mod.getUpdateURL().get();
                     LOGGER.info("[{}] Starting version check at {}", mod.getModId(), url.toString());
 
-                    InputStream con = openUrlStream(url);
-                    String data = new String(ByteStreams.toByteArray(con), StandardCharsets.UTF_8);
-                    con.close();
+                    String data = openUrlString(url);
 
                     LOGGER.debug("[{}] Received version check data:\n{}", mod.getModId(), data);
 
@@ -216,7 +192,7 @@ public class VersionChecker
                     Map<String, String> promos = (Map<String, String>)json.get("promos");
                     display_url = (String)json.get("homepage");
 
-                    String mcVersion = MCPVersion.getMCVersion();
+                    var mcVersion = FMLLoader.versionInfo().mcVersion();
                     String rec = promos.get(mcVersion + "-recommended");
                     String lat = promos.get(mcVersion + "-latest");
                     ComparableVersion current = new ComparableVersion(mod.getVersion().toString());
@@ -297,9 +273,8 @@ public class VersionChecker
     private static List<IModInfo> gatherMods()
     {
         List<IModInfo> ret = new LinkedList<>();
-        for (ModInfo info : ModList.get().getMods()) {
-            URL url = info.getUpdateURL();
-            if (url != null)
+        for (IModInfo info : ModList.get().getMods()) {
+            if (info.getUpdateURL().isPresent())
                 ret.add(info);
         }
         return ret;

fmlcore/src/main/java/net/minecraftforge/fml/config/ConfigFileTypeHandler.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -22,9 +22,11 @@ package net.minecraftforge.fml.config;
 import com.electronwill.nightconfig.core.ConfigFormat;
 import com.electronwill.nightconfig.core.file.CommentedFileConfig;
 import com.electronwill.nightconfig.core.file.FileWatcher;
+import com.electronwill.nightconfig.core.io.ParsingException;
 import com.electronwill.nightconfig.core.io.WritingMode;
 import net.minecraftforge.fml.loading.FMLConfig;
 import net.minecraftforge.fml.loading.FMLPaths;
+import org.apache.commons.io.FilenameUtils;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
@@ -50,7 +52,14 @@ public class ConfigFileTypeHandler {
                     writingMode(WritingMode.REPLACE).
                     build();
             LOGGER.debug(CONFIG, "Built TOML config for {}", configPath.toString());
-            configData.load();
+            try
+            {
+                configData.load();
+            }
+            catch (ParsingException ex)
+            {
+                throw new ConfigLoadingException(c, ex);
+            }
             LOGGER.debug(CONFIG, "Loaded TOML config file {}", configPath.toString());
             try {
                 FileWatcher.defaultInstance().addWatch(configPath, new ConfigWatcher(c, configData, Thread.currentThread().getContextClassLoader()));
@@ -83,6 +92,38 @@ public class ConfigFileTypeHandler {
         return true;
     }
 
+    public static void backUpConfig(final CommentedFileConfig commentedFileConfig)
+    {
+        backUpConfig(commentedFileConfig, 5); //TODO: Think of a way for mods to set their own preference (include a sanity check as well, no disk stuffing)
+    }
+
+    public static void backUpConfig(final CommentedFileConfig commentedFileConfig, final int maxBackups)
+    {
+        Path bakFileLocation = commentedFileConfig.getNioPath().getParent();
+        String bakFileName = FilenameUtils.removeExtension(commentedFileConfig.getFile().getName());
+        String bakFileExtension = FilenameUtils.getExtension(commentedFileConfig.getFile().getName()) + ".bak";
+        Path bakFile = bakFileLocation.resolve(bakFileName + "-1" + "." + bakFileExtension);
+        try
+        {
+            for(int i = maxBackups; i > 0; i--)
+            {
+                Path oldBak = bakFileLocation.resolve(bakFileName + "-" + i + "." + bakFileExtension);
+                if(Files.exists(oldBak))
+                {
+                    if(i >= maxBackups)
+                        Files.delete(oldBak);
+                    else
+                        Files.move(oldBak, bakFileLocation.resolve(bakFileName + "-" + (i + 1) + "." + bakFileExtension));
+                }
+            }
+            Files.copy(commentedFileConfig.getNioPath(), bakFile);
+        }
+        catch (IOException exception)
+        {
+            LOGGER.warn(CONFIG, "Failed to back up config file {}", commentedFileConfig.getNioPath(), exception);
+        }
+    }
+
     private static class ConfigWatcher implements Runnable {
         private final ModConfig modConfig;
         private final CommentedFileConfig commentedFileConfig;
@@ -99,10 +140,33 @@ public class ConfigFileTypeHandler {
             // Force the regular classloader onto the special thread
             Thread.currentThread().setContextClassLoader(realClassLoader);
             if (!this.modConfig.getSpec().isCorrecting()) {
-                this.commentedFileConfig.load();
+                try
+                {
+                    this.commentedFileConfig.load();
+                    if(!this.modConfig.getSpec().isCorrect(commentedFileConfig))
+                    {
+                        LOGGER.warn(CONFIG, "Configuration file {} is not correct. Correcting", commentedFileConfig.getFile().getAbsolutePath());
+                        ConfigFileTypeHandler.backUpConfig(commentedFileConfig);
+                        this.modConfig.getSpec().correct(commentedFileConfig);
+                        commentedFileConfig.save();
+                    }
+                }
+                catch (ParsingException ex)
+                {
+                    throw new ConfigLoadingException(modConfig, ex);
+                }
                 LOGGER.debug(CONFIG, "Config file {} changed, sending notifies", this.modConfig.getFileName());
-                this.modConfig.fireEvent(new ModConfig.Reloading(this.modConfig));
+                this.modConfig.getSpec().afterReload();
+                this.modConfig.fireEvent(IConfigEvent.reloading(this.modConfig));
             }
         }
     }
+
+    private static class ConfigLoadingException extends RuntimeException
+    {
+        public ConfigLoadingException(ModConfig config, Exception cause)
+        {
+            super("Failed loading config file " + config.getFileName() + " of type " + config.getType() + " for modid " + config.getModId(), cause);
+        }
+    }
 }

fmlcore/src/main/java/net/minecraftforge/fml/config/ConfigTracker.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -21,33 +21,14 @@ package net.minecraftforge.fml.config;
 
 import com.electronwill.nightconfig.core.CommentedConfig;
 import com.electronwill.nightconfig.core.file.CommentedFileConfig;
-import com.electronwill.nightconfig.toml.TomlFormat;
-import it.unimi.dsi.fastutil.bytes.Byte2ByteOpenCustomHashMap;
-import net.minecraft.client.Minecraft;
-import net.minecraftforge.fml.network.FMLHandshakeMessages;
-import net.minecraftforge.fml.network.NetworkEvent;
-import org.apache.commons.lang3.tuple.Pair;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.Marker;
 import org.apache.logging.log4j.MarkerManager;
 
-import java.io.ByteArrayInputStream;
-import java.io.IOException;
-import java.nio.file.Files;
 import java.nio.file.Path;
-import java.util.Collections;
-import java.util.EnumMap;
-import java.util.LinkedHashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Optional;
-import java.util.Set;
+import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
-import java.util.function.Supplier;
-import java.util.stream.Collectors;
-
-import static cpw.mods.modlauncher.api.LamdbaExceptionUtils.rethrowFunction;
 
 public class ConfigTracker {
     private static final Logger LOGGER = LogManager.getLogger();
@@ -55,7 +36,7 @@ public class ConfigTracker {
     public static final ConfigTracker INSTANCE = new ConfigTracker();
     private final ConcurrentHashMap<String, ModConfig> fileMap;
     private final EnumMap<ModConfig.Type, Set<ModConfig>> configSets;
-    private ConcurrentHashMap<String, Map<ModConfig.Type, ModConfig>> configsByMod;
+    private final ConcurrentHashMap<String, Map<ModConfig.Type, ModConfig>> configsByMod;
 
     private ConfigTracker() {
         this.fileMap = new ConcurrentHashMap<>();
@@ -88,22 +69,11 @@ public class ConfigTracker {
         this.configSets.get(type).forEach(config -> closeConfig(config, configBasePath));
     }
 
-    public List<Pair<String, FMLHandshakeMessages.S2CConfigData>> syncConfigs(boolean isLocal) {
-        final Map<String, byte[]> configData = configSets.get(ModConfig.Type.SERVER).stream().collect(Collectors.toMap(ModConfig::getFileName, mc -> { //TODO: Test cpw's LambdaExceptionUtils on Oracle javac.
-            try {
-                return Files.readAllBytes(mc.getFullPath());
-            } catch (IOException e) {
-                throw new RuntimeException(e);
-            }
-        }));
-        return configData.entrySet().stream().map(e->Pair.of("Config "+e.getKey(), new FMLHandshakeMessages.S2CConfigData(e.getKey(), e.getValue()))).collect(Collectors.toList());
-    }
-
     private void openConfig(final ModConfig config, final Path configBasePath) {
         LOGGER.trace(CONFIG, "Loading config file type {} at {} for {}", config.getType(), config.getFileName(), config.getModId());
         final CommentedFileConfig configData = config.getHandler().reader(configBasePath).apply(config);
         config.setConfigData(configData);
-        config.fireEvent(new ModConfig.Loading(config));
+        config.fireEvent(IConfigEvent.loading(config));
         config.save();
     }
 
@@ -116,21 +86,12 @@ public class ConfigTracker {
         }
     }
 
-    public void receiveSyncedConfig(final FMLHandshakeMessages.S2CConfigData s2CConfigData, final Supplier<NetworkEvent.Context> contextSupplier) {
-        if (!Minecraft.getInstance().isIntegratedServerRunning()) {
-            Optional.ofNullable(fileMap.get(s2CConfigData.getFileName())).ifPresent(mc-> {
-                mc.setConfigData(TomlFormat.instance().createParser().parse(new ByteArrayInputStream(s2CConfigData.getBytes())));
-                mc.fireEvent(new ModConfig.Reloading(mc));
-            });
-        }
-    }
-
     public void loadDefaultServerConfigs() {
         configSets.get(ModConfig.Type.SERVER).forEach(modConfig -> {
             final CommentedConfig commentedConfig = CommentedConfig.inMemory();
             modConfig.getSpec().correct(commentedConfig);
             modConfig.setConfigData(commentedConfig);
-            modConfig.fireEvent(new ModConfig.Loading(modConfig));
+            modConfig.fireEvent(IConfigEvent.loading(modConfig));
         });
     }
 
@@ -138,4 +99,12 @@ public class ConfigTracker {
         return Optional.ofNullable(configsByMod.getOrDefault(modId, Collections.emptyMap()).getOrDefault(type, null)).
                 map(ModConfig::getFullPath).map(Object::toString).orElse(null);
     }
+
+    public Map<ModConfig.Type, Set<ModConfig>> configSets() {
+        return configSets;
+    }
+
+    public ConcurrentHashMap<String, ModConfig> fileMap() {
+        return fileMap;
+    }
 }

fmlcore/src/main/java/net/minecraftforge/fml/config/IConfigEvent.java

@@ -0,0 +1,24 @@
+package net.minecraftforge.fml.config;
+
+import net.minecraftforge.eventbus.api.Event;
+import net.minecraftforge.fml.Bindings;
+
+import java.util.function.Function;
+
+public interface IConfigEvent {
+    record ConfigConfig(Function<ModConfig, IConfigEvent> loading, Function<ModConfig, IConfigEvent> reloading) {}
+    ConfigConfig CONFIGCONFIG = Bindings.getConfigConfiguration().get();
+
+    static IConfigEvent reloading(ModConfig modConfig) {
+        return CONFIGCONFIG.reloading().apply(modConfig);
+    }
+    static IConfigEvent loading(ModConfig modConfig) {
+        return CONFIGCONFIG.loading().apply(modConfig);
+    }
+    ModConfig getConfig();
+
+    @SuppressWarnings("unchecked")
+    default <T extends Event & IConfigEvent> T self() {
+        return (T) this;
+    }
+}

fmlcore/src/main/java/net/minecraftforge/fml/config/IConfigSpec.java

@@ -0,0 +1,21 @@
+package net.minecraftforge.fml.config;
+
+import com.electronwill.nightconfig.core.CommentedConfig;
+import com.electronwill.nightconfig.core.UnmodifiableConfig;
+
+public interface IConfigSpec<T extends IConfigSpec<T>> extends UnmodifiableConfig {
+    @SuppressWarnings("unchecked")
+    default T self() {
+        return (T) this;
+    }
+
+    void acceptConfig(CommentedConfig data);
+
+    boolean isCorrecting();
+
+    boolean isCorrect(CommentedConfig commentedFileConfig);
+
+    int correct(CommentedConfig commentedFileConfig);
+
+    void afterReload();
+}

fmlcore/src/main/java/net/minecraftforge/fml/config/ModConfig.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -21,25 +21,25 @@ package net.minecraftforge.fml.config;
 
 import com.electronwill.nightconfig.core.CommentedConfig;
 import com.electronwill.nightconfig.core.file.CommentedFileConfig;
-import net.minecraftforge.common.ForgeConfigSpec;
-import net.minecraftforge.eventbus.api.Event;
+import com.electronwill.nightconfig.toml.TomlFormat;
 import net.minecraftforge.fml.ModContainer;
 import net.minecraftforge.fml.loading.StringUtils;
 
+import java.io.ByteArrayInputStream;
 import java.nio.file.Path;
 import java.util.concurrent.Callable;
 
 public class ModConfig
 {
     private final Type type;
-    private final ForgeConfigSpec spec;
+    private final IConfigSpec<?> spec;
     private final String fileName;
     private final ModContainer container;
     private final ConfigFileTypeHandler configHandler;
     private CommentedConfig configData;
     private Callable<Void> saveHandler;
 
-    public ModConfig(final Type type, final ForgeConfigSpec spec, final ModContainer container, final String fileName) {
+    public ModConfig(final Type type, final IConfigSpec<?> spec, final ModContainer container, final String fileName) {
         this.type = type;
         this.spec = spec;
         this.fileName = fileName;
@@ -48,7 +48,7 @@ public class ModConfig
         ConfigTracker.INSTANCE.trackConfig(this);
     }
 
-    public ModConfig(final Type type, final ForgeConfigSpec spec, final ModContainer activeContainer) {
+    public ModConfig(final Type type, final IConfigSpec<?> spec, final ModContainer activeContainer) {
         this(type, spec, activeContainer, defaultConfigName(type, activeContainer.getModId()));
     }
 
@@ -68,8 +68,9 @@ public class ModConfig
         return configHandler;
     }
 
-    public ForgeConfigSpec getSpec() {
-        return spec;
+    @SuppressWarnings("unchecked")
+    public <T extends IConfigSpec<T>> IConfigSpec<T> getSpec() {
+        return (IConfigSpec<T>) spec;
     }
 
     public String getModId() {
@@ -82,10 +83,10 @@ public class ModConfig
 
     void setConfigData(final CommentedConfig configData) {
         this.configData = configData;
-        this.spec.setConfig(this.configData);
+        this.spec.acceptConfig(this.configData);
     }
 
-    void fireEvent(final ModConfigEvent configEvent) {
+    void fireEvent(final IConfigEvent configEvent) {
         this.container.dispatchConfigEvent(configEvent);
     }
 
@@ -97,6 +98,11 @@ public class ModConfig
         return ((CommentedFileConfig)this.configData).getNioPath();
     }
 
+    public void acceptSyncedConfig(byte[] bytes) {
+        setConfigData(TomlFormat.instance().createParser().parse(new ByteArrayInputStream(bytes)));
+        fireEvent(IConfigEvent.reloading(this));
+    }
+
     public enum Type {
         /**
          * Common mod config for configuration that needs to be loaded on both environments.
@@ -132,28 +138,4 @@ public class ModConfig
             return StringUtils.toLowerCase(name());
         }
     }
-
-    public static class ModConfigEvent extends Event {
-        private final ModConfig config;
-
-        ModConfigEvent(final ModConfig config) {
-            this.config = config;
-        }
-
-        public ModConfig getConfig() {
-            return config;
-        }
-    }
-
-    public static class Loading extends ModConfigEvent {
-        Loading(final ModConfig config) {
-            super(config);
-        }
-    }
-
-    public static class Reloading extends ModConfigEvent {
-        Reloading(final ModConfig config) {
-            super(config);
-        }
-    }
 }

fmlcore/src/main/java/net/minecraftforge/fml/event/IModBusEvent.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -17,12 +17,10 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-package net.minecraftforge.client.extensions;
+package net.minecraftforge.fml.event;
 
-public interface IForgeResourcePack
-{
-    default boolean isHidden()
-    {
-        return false;
-    }
+/**
+ * Marker interface for events dispatched on the ModLifecycle event bus instead of the primary event bus
+ */
+public interface IModBusEvent {
 }

fmlcore/src/main/java/net/minecraftforge/fml/util/CertificateHelper.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -17,7 +17,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-package net.minecraftforge.fml.common;
+package net.minecraftforge.fml.util;
 
 import com.google.common.collect.ImmutableList;
 

fmlcore/src/main/java/net/minecraftforge/fml/util/EnhancedRuntimeException.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -17,7 +17,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-package net.minecraftforge.fml.common;
+package net.minecraftforge.fml.util;
 
 import java.io.PrintStream;
 import java.io.PrintWriter;

fmlcore/src/main/java/net/minecraftforge/fml/util/LoaderException.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -17,8 +17,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-package net.minecraftforge.fml.common;
-import net.minecraftforge.fml.common.EnhancedRuntimeException.WrappedPrintStream;
+package net.minecraftforge.fml.util;
 
 
 public class LoaderException extends EnhancedRuntimeException

fmlcore/src/main/java/net/minecraftforge/fml/util/LoaderExceptionModCrash.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -17,7 +17,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-package net.minecraftforge.fml.common;
+package net.minecraftforge.fml.util;
 
 /**
  * Prevent LoaderException from adding its own stack trace to the wrapped throwable's stack trace.

fmlcore/src/main/java/net/minecraftforge/fml/util/ObfuscationReflectionHelper.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -17,15 +17,12 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-package net.minecraftforge.fml.common;
+package net.minecraftforge.fml.util;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.util.StringJoiner;
 
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-
 import cpw.mods.modlauncher.api.INameMappingService;
 import net.minecraftforge.fml.loading.FMLLoader;
 import org.apache.logging.log4j.LogManager;
@@ -34,6 +31,8 @@ import org.apache.logging.log4j.Marker;
 import org.apache.logging.log4j.MarkerManager;
 
 import com.google.common.base.Preconditions;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * Some reflection helper code.
@@ -58,7 +57,7 @@ public class ObfuscationReflectionHelper
      * @param name   The name to try and remap.
      * @return The remapped name, or the original name if it couldn't be remapped.
      */
-    @Nonnull
+    @NotNull
     public static String remapName(INameMappingService.Domain domain, String name)
     {
         return FMLLoader.getNameFunction("srg").map(f->f.apply(domain, name)).orElse(name);
@@ -72,7 +71,7 @@ public class ObfuscationReflectionHelper
      *
      * @param classToAccess The class to find the field on.
      * @param instance      The instance of the {@code classToAccess}.
-     * @param fieldName     The SRG (unmapped) name of the field to find (e.g. "field_181725_a").
+     * @param fieldName     The SRG (unmapped) name of the field to find (e.g. "f_46443_").
      * @param <T>           The type of the value.
      * @param <E>           The type of the {@code classToAccess}.
      * @return The value of the field with the specified name in the {@code classToAccess}.
@@ -113,7 +112,7 @@ public class ObfuscationReflectionHelper
      * @throws UnableToFindFieldException   If there was a problem getting the field.
      * @throws UnableToAccessFieldException If there was a problem setting the value of the field.
      */
-    public static <T, E> void setPrivateValue(@Nonnull final Class<? super T> classToAccess, @Nonnull final T instance, @Nullable final E value, @Nonnull final String fieldName)
+    public static <T, E> void setPrivateValue(@NotNull final Class<? super T> classToAccess, @NotNull final T instance, @Nullable final E value, @NotNull final String fieldName)
     {
         try
         {
@@ -138,7 +137,7 @@ public class ObfuscationReflectionHelper
      * Throws an exception if the method is not found.
      *
      * @param clazz          The class to find the method on.
-     * @param methodName     The SRG (unmapped) name of the method to find (e.g. "func_12820_D").
+     * @param methodName     The SRG (unmapped) name of the method to find (e.g. "m_5776_").
      * @param parameterTypes The parameter types of the method to find.
      * @return The method with the specified name and parameters in the given class.
      * @throws NullPointerException        If {@code clazz} is null.
@@ -147,8 +146,8 @@ public class ObfuscationReflectionHelper
      * @throws NullPointerException        If {@code parameterTypes} is null.
      * @throws UnableToFindMethodException If the method could not be found.
      */
-    @Nonnull
-    public static Method findMethod(@Nonnull final Class<?> clazz, @Nonnull final String methodName, @Nonnull final Class<?>... parameterTypes)
+    @NotNull
+    public static Method findMethod(@NotNull final Class<?> clazz, @NotNull final String methodName, @NotNull final Class<?>... parameterTypes)
     {
         Preconditions.checkNotNull(clazz, "Class to find method on cannot be null.");
         Preconditions.checkNotNull(methodName, "Name of method to find cannot be null.");
@@ -181,8 +180,8 @@ public class ObfuscationReflectionHelper
      * @throws NullPointerException        If {@code parameterTypes} is null.
      * @throws UnknownConstructorException If the constructor could not be found.
      */
-    @Nonnull
-    public static <T> Constructor<T> findConstructor(@Nonnull final Class<T> clazz, @Nonnull final Class<?>... parameterTypes)
+    @NotNull
+    public static <T> Constructor<T> findConstructor(@NotNull final Class<T> clazz, @NotNull final Class<?>... parameterTypes)
     {
         Preconditions.checkNotNull(clazz, "Class to find constructor on cannot be null.");
         Preconditions.checkNotNull(parameterTypes, "Parameter types of constructor to find cannot be null.");
@@ -216,7 +215,7 @@ public class ObfuscationReflectionHelper
      * Throws an exception if the field is not found.
      *
      * @param clazz     The class to find the field on.
-     * @param fieldName The SRG (unmapped) name of the field to find (e.g. "field_181725_a").
+     * @param fieldName The SRG (unmapped) name of the field to find (e.g. "f_46443_").
      * @param <T>       The type.
      * @return The constructor with the specified parameters in the given class.
      * @throws NullPointerException       If {@code clazz} is null.
@@ -224,8 +223,8 @@ public class ObfuscationReflectionHelper
      * @throws IllegalArgumentException   If {@code fieldName} is empty.
      * @throws UnableToFindFieldException If the field could not be found.
      */
-    @Nonnull
-    public static <T> Field findField(@Nonnull final Class<? super T> clazz, @Nonnull final String fieldName)
+    @NotNull
+    public static <T> Field findField(@NotNull final Class<? super T> clazz, @NotNull final String fieldName)
     {
         Preconditions.checkNotNull(clazz, "Class to find field on cannot be null.");
         Preconditions.checkNotNull(fieldName, "Name of field to find cannot be null.");

fmlcore/src/main/java/net/minecraftforge/fml/util/thread/EffectiveSide.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -17,7 +17,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-package net.minecraftforge.fml.common.thread;
+package net.minecraftforge.fml.util.thread;
 
 import net.minecraftforge.fml.LogicalSide;
 

fmlcore/src/main/java/net/minecraftforge/fml/util/thread/SidedThreadGroup.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -17,14 +17,13 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-package net.minecraftforge.fml.common.thread;
+package net.minecraftforge.fml.util.thread;
 
 import net.minecraftforge.fml.LogicalSide;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.concurrent.ThreadFactory;
 
-import javax.annotation.Nonnull;
-
 /**
  * A thread group and factory combination which belongs to a {@link LogicalSide}.
  */
@@ -49,7 +48,7 @@ public final class SidedThreadGroup extends ThreadGroup implements ThreadFactory
     }
 
     @Override
-    public Thread newThread(@Nonnull final Runnable runnable)
+    public Thread newThread(@NotNull final Runnable runnable)
     {
         return new Thread(this, runnable);
     }

fmlcore/src/main/java/net/minecraftforge/fml/util/thread/SidedThreadGroups.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -17,7 +17,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-package net.minecraftforge.fml.common.thread;
+package net.minecraftforge.fml.util.thread;
 
 import net.minecraftforge.fml.LogicalSide;
 

fmlloader/build.gradle

@@ -0,0 +1,80 @@
+plugins {
+    id 'com.github.ben-manes.versions'
+    id 'org.javamodularity.moduleplugin' version '1.8.3' apply false
+}
+apply plugin: 'java-library'
+apply plugin: 'jacoco'
+apply plugin: 'org.javamodularity.moduleplugin'
+
+dependencyUpdates.rejectVersionIf { isNonStable(it.candidate.version) }
+configurations.forEach{ it.transitive = false }
+
+dependencies {
+    implementation('net.sf.jopt-simple:jopt-simple:5.0.4')
+    compileOnly('org.jetbrains:annotations:21.0.0')
+    api("org.ow2.asm:asm:${ASM_VERSION}")
+    api("org.ow2.asm:asm-tree:${ASM_VERSION}")
+    api("org.ow2.asm:asm-commons:${ASM_VERSION}")
+    api('net.minecraftforge:forgespi:4.0.+')
+    api('org.apache.logging.log4j:log4j-api:2.14.1')
+    api('com.google.guava:guava:21.0')
+    api('com.google.code.gson:gson:2.8.0')
+    api('org.apache.maven:maven-artifact:3.8.1')
+    api('org.apache.commons:commons-lang3:3.8.1')
+    api('com.electronwill.night-config:core:3.6.3')
+    api('com.electronwill.night-config:toml:3.6.3')
+    api('cpw.mods:modlauncher:9.0.+')
+    api('net.minecraftforge:coremods:5.0.+')
+    implementation("cpw.mods:securejarhandler:${SECUREJARHANDLER_VERSION}")
+    implementation('org.apache.logging.log4j:log4j-core:2.14.1')
+    annotationProcessor('org.apache.logging.log4j:log4j-core:2.14.1')
+    implementation('net.minecraftforge:accesstransformers:8.0.4')
+    implementation('net.minecrell:terminalconsoleappender:1.2.0')
+//    implementation('org.jline:jline:3.12.+')
+    testCompileOnly('org.jetbrains:annotations:21.0.0')
+    testRuntimeOnly("cpw.mods:bootstraplauncher:${BOOTSTRAPLAUNCHER_VERSION}")
+}
+
+task sourcesJar(type: Jar) {
+    archiveClassifier = 'sources'
+    from sourceSets.main.allSource
+}
+
+ext {
+    MANIFESTS = [
+        '/': [
+            'Timestamp': new Date().format("yyyy-MM-dd'T'HH:mm:ssZ"),
+            'Git-Commit': GIT_INFO.abbreviatedId,
+            'Git-Branch': GIT_INFO.branch,
+            'Build-Number': "${System.getenv('BUILD_NUMBER')?:0}",
+        ] as LinkedHashMap,
+        'net/minecraftforge/fml/loading/': [
+            'Specification-Title':      'FMLLoader',
+            'Specification-Vendor':     'Forge Development LLC',
+            'Specification-Version':    '1',
+            'Implementation-Title':     'FML Loader',
+            'Implementation-Version':   '1.0',
+            'Implementation-Vendor':    'Forge'
+        ] as LinkedHashMap
+    ]
+}
+
+jar.doFirst {
+    MANIFESTS.each { pkg, values ->
+        manifest.attributes(values, pkg)
+    }
+}
+
+tasks.withType(JavaCompile) {
+    options.compilerArgs << '-Xlint:unchecked'
+}
+
+artifacts {
+    archives jar
+    archives sourcesJar
+}
+
+publishing.publications.mavenJava(MavenPublication) {
+    from components.java
+    artifact sourcesJar
+}

fmlloader/src/main/java/net/minecraftforge/common/asm/CapabilityInjectDefinalize.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -19,7 +19,6 @@
 
 package net.minecraftforge.common.asm;
 
-import java.nio.file.Path;
 import java.util.EnumSet;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -33,6 +32,7 @@ import cpw.mods.modlauncher.serviceapi.ILaunchPluginService;
 /**
  * Removes the final modifier from fields with the @CapabilityInject annotation, prevents the JITer from in lining them so our runtime replacements can work.
  */
+@Deprecated(since = "1.18", forRemoval = true)
 public class CapabilityInjectDefinalize implements ILaunchPluginService {
 
     private final String CAP        = "Lnet/minecraftforge/common/capabilities/Capability;";       //Don't directly reference this to prevent class loading.
@@ -58,10 +58,10 @@ public class CapabilityInjectDefinalize implements ILaunchPluginService {
     }
 
     @Override
-    public boolean processClass(Phase phase, ClassNode classNode, Type classType)
+    public int processClassWithFlags(final Phase phase, final ClassNode classNode, final Type classType, final String reason)
     {
         final int flags = Opcodes.ACC_PUBLIC | Opcodes.ACC_STATIC | Opcodes.ACC_FINAL;
-        AtomicBoolean changed = new AtomicBoolean();
+        final AtomicBoolean changed = new AtomicBoolean();
         classNode.fields.stream().filter(f -> ((f.access & flags) == flags) && f.desc.equals(CAP) && hasHolder(f.visibleAnnotations)).forEach(f ->
         {
             int prev = f.access;
@@ -70,7 +70,7 @@ public class CapabilityInjectDefinalize implements ILaunchPluginService {
             changed.compareAndSet(false, prev != f.access);
         });
 
-        return changed.get();
+        return changed.get() ? ComputeFlags.SIMPLE_REWRITE : ComputeFlags.NO_REWRITE;
     }
 
 }

fmlloader/src/main/java/net/minecraftforge/common/asm/CapabilityTokenSubclass.java

@@ -0,0 +1,134 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2021.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.minecraftforge.common.asm;
+
+import java.util.ArrayDeque;
+import java.util.Deque;
+import java.util.EnumSet;
+
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.Type;
+import org.objectweb.asm.signature.SignatureReader;
+import org.objectweb.asm.signature.SignatureVisitor;
+import org.objectweb.asm.tree.ClassNode;
+import org.objectweb.asm.tree.MethodNode;
+
+import cpw.mods.modlauncher.serviceapi.ILaunchPluginService;
+
+/**
+ * Implements getType() in CapabilityToken subclasses.
+ *
+ * Using the class's signature to determine the generic type of TypeToken, and then implements getType() using that value.
+ * <pre>
+ * Example:
+ *
+ *  <code>new CapabilityToken&lt;String>(){}</code>
+ *  Has the signature <code>"CapabilityToken&lt;Ljava/lang/String;>"</code>
+ *
+ *  Implements the method:
+ *  <code>public String getType() {
+ *    return "java/lang/String";
+ *  }</code>
+ * </pre>
+ */
+public class CapabilityTokenSubclass implements ILaunchPluginService {
+
+    private final String FUNC_NAME = "getType";
+    private final String FUNC_DESC = "()Ljava/lang/String;";
+    private final String CAP_INJECT = "net/minecraftforge/common/capabilities/CapabilityToken"; //Don't directly reference this to prevent class loading.
+
+    @Override
+    public String name() {
+        return "capability_token_subclass";
+    }
+
+    private static final EnumSet<Phase> YAY = EnumSet.of(Phase.AFTER);
+    private static final EnumSet<Phase> NAY = EnumSet.noneOf(Phase.class);
+
+    @Override
+    public EnumSet<Phase> handlesClass(Type classType, boolean isEmpty)
+    {
+        return isEmpty ? NAY : YAY;
+    }
+
+    @Override
+    public int processClassWithFlags(final Phase phase, final ClassNode classNode, final Type classType, final String reason)
+    {
+        if (CAP_INJECT.equals(classNode.name))
+        {
+            for (MethodNode mtd : classNode.methods)
+            {
+                if (FUNC_NAME.equals(mtd.name) && FUNC_DESC.equals(mtd.desc))
+                {
+                    mtd.access &= ~Opcodes.ACC_FINAL; // We have it final in code so people don't override it, cuz that'd be stupid, and make our transformer more complicated.
+                }
+            }
+            return ComputeFlags.SIMPLE_REWRITE;
+        }
+        else if (CAP_INJECT.equals(classNode.superName))
+        {
+            Holder cls = new Holder();
+
+            SignatureReader reader = new SignatureReader(classNode.signature); // Having a node version of this would probably be useful.
+            reader.accept(new SignatureVisitor(Opcodes.ASM9)
+            {
+                Deque<String> stack = new ArrayDeque<>();
+
+                @Override
+                public void visitClassType(final String name)
+                {
+                    stack.push(name);
+                }
+
+                @Override
+                public void visitInnerClassType(final String name)
+                {
+                    stack.push(stack.pop() + '$' + name);
+                }
+
+                @Override
+                public void visitEnd()
+                {
+                    var val = stack.pop();
+                    if (!stack.isEmpty() && CAP_INJECT.equals(stack.peek()))
+                        cls.value = val;
+                }
+            });
+
+            if (cls.value == null)
+                throw new IllegalStateException("Could not find signature for CapabilityToken on " + classNode.name + " from " + classNode.signature);
+
+            var mtd = classNode.visitMethod(Opcodes.ACC_PUBLIC, FUNC_NAME, FUNC_DESC, null, new String[0]);
+            mtd.visitLdcInsn(cls.value);
+            mtd.visitInsn(Opcodes.ARETURN);
+            mtd.visitEnd();
+            return ComputeFlags.COMPUTE_MAXS;
+        }
+        else
+        {
+            return ComputeFlags.NO_REWRITE;
+        }
+    }
+
+    private static class Holder {
+        String value;
+    }
+
+}

fmlloader/src/main/java/net/minecraftforge/common/asm/ObjectHolderDefinalize.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -73,9 +73,9 @@ public class ObjectHolderDefinalize implements ILaunchPluginService {
     }
 
     @Override
-    public boolean processClass(Phase phase, ClassNode classNode, Type classType)
+    public int processClassWithFlags(final Phase phase, final ClassNode classNode, final Type classType, final String reason)
     {
-        AtomicBoolean changes = new AtomicBoolean();
+        final AtomicBoolean changes = new AtomicBoolean();
         //Must be public static finals, and non-array objects
         final int flags = Opcodes.ACC_PUBLIC | Opcodes.ACC_STATIC | Opcodes.ACC_FINAL;
 
@@ -107,7 +107,7 @@ public class ObjectHolderDefinalize implements ILaunchPluginService {
                 changes.compareAndSet(false, prev != f.access);
             });
         }
-        return changes.get();
+        return changes.get() ? ComputeFlags.SIMPLE_REWRITE : ComputeFlags.NO_REWRITE;
     }
 
 }

fmlloader/src/main/java/net/minecraftforge/common/asm/RuntimeEnumExtender.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -69,10 +69,10 @@ public class RuntimeEnumExtender implements ILaunchPluginService {
     }
 
     @Override
-    public boolean processClass(Phase phase, ClassNode classNode, Type classType)
+    public int processClassWithFlags(final Phase phase, final ClassNode classNode, final Type classType, final String reason)
     {
         if ((classNode.access & Opcodes.ACC_ENUM) == 0)
-            return false;
+            return ComputeFlags.NO_REWRITE;
 
         Type array = Type.getType("[" + classType.getDescriptor());
         final int flags = Opcodes.ACC_PRIVATE | Opcodes.ACC_STATIC | Opcodes.ACC_FINAL | Opcodes.ACC_SYNTHETIC;
@@ -80,7 +80,7 @@ public class RuntimeEnumExtender implements ILaunchPluginService {
         FieldNode values = classNode.fields.stream().filter(f -> f.desc.contentEquals(array.getDescriptor()) && ((f.access & flags) == flags)).findFirst().orElse(null);
         
         if (!classNode.interfaces.contains(MARKER_IFACE.getInternalName())) {
-            return false;
+            return ComputeFlags.NO_REWRITE;
         }
         
         //Static methods named "create" with first argument as a string
@@ -98,8 +98,8 @@ public class RuntimeEnumExtender implements ILaunchPluginService {
             if (args.length == 0 || !args[0].equals(STRING)) {
                 LOGGER.fatal(()->new AdvancedLogMessageAdapter(sb-> {
                     sb.append("Enum has create method without String as first parameter:\n");
-                    sb.append("  Enum: " + classType.getDescriptor()).append("\n");
-                    sb.append("  Target: ").append(mtd.name + mtd.desc).append("\n");
+                    sb.append("  Enum: ").append(classType.getDescriptor()).append("\n");
+                    sb.append("  Target: ").append(mtd.name).append(mtd.desc).append("\n");
                 }));
                 throw new IllegalStateException("Enum has create method without String as first parameter: " + mtd.name + mtd.desc);
             }
@@ -108,8 +108,8 @@ public class RuntimeEnumExtender implements ILaunchPluginService {
             if (!ret.equals(classType)) {
                 LOGGER.fatal(()->new AdvancedLogMessageAdapter(sb-> {
                     sb.append("Enum has create method with incorrect return type:\n");
-                    sb.append("  Enum: " + classType.getDescriptor()).append("\n");
-                    sb.append("  Target: ").append(mtd.name + mtd.desc).append("\n");
+                    sb.append("  Enum: ").append(classType.getDescriptor()).append("\n");
+                    sb.append("  Target: ").append(mtd.name).append(mtd.desc).append("\n");
                     sb.append("  Found: ").append(ret.getClassName()).append(", Expected: ").append(classType.getClassName());
                 }));
                 throw new IllegalStateException("Enum has create method with incorrect return type: " + mtd.name + mtd.desc);
@@ -223,7 +223,7 @@ public class RuntimeEnumExtender implements ILaunchPluginService {
                 ins.areturn(classType);
             }
         });
-        return true;
+        return ComputeFlags.COMPUTE_FRAMES;
     }
 
 }

fmlloader/src/main/java/net/minecraftforge/fml/loading/AdvancedLogMessageAdapter.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -25,6 +25,8 @@ import org.apache.logging.log4j.util.StringBuilderFormattable;
 import java.util.function.Consumer;
 
 public class AdvancedLogMessageAdapter implements Message, StringBuilderFormattable {
+    private static final long serialVersionUID = -8291754833965087436L;
+
     private static final Object[] EMPTY = new Object[0];
 
     private final Consumer<StringBuilder> logMessageBuilder;

fmlloader/src/main/java/net/minecraftforge/fml/loading/BackgroundWaiter.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -19,6 +19,7 @@
 
 package net.minecraftforge.fml.loading;
 
+import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.Future;
@@ -35,5 +36,13 @@ public class BackgroundWaiter {
             } catch (InterruptedException ignored) {
             }
         } while (!work.isDone());
+        try {
+            runner.shutdown();
+            work.get();
+        } catch (ExecutionException ee) {
+            throw new RuntimeException(ee.getCause());
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        }
     }
 }

fmlloader/src/main/java/net/minecraftforge/fml/loading/EarlyLoadingException.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -19,6 +19,8 @@
 
 package net.minecraftforge.fml.loading;
 
+import net.minecraftforge.forgespi.language.IModInfo;
+
 import java.util.List;
 
 /**
@@ -27,12 +29,17 @@ import java.util.List;
  */
 public class EarlyLoadingException extends RuntimeException {
     public static class ExceptionData {
-
-
+        private final IModInfo modInfo;
         private final String i18message;
         private final Object[] args;
+
         public ExceptionData(final String message, Object... args) {
+            this(message, null, args);
+        }
+
+        public ExceptionData(final String message, final IModInfo modInfo, Object... args) {
             this.i18message = message;
+            this.modInfo = modInfo;
             this.args = args;
         }
 
@@ -43,6 +50,10 @@ public class EarlyLoadingException extends RuntimeException {
         public Object[] getArgs() {
             return args;
         }
+
+        public IModInfo getModInfo() {
+            return modInfo;
+        }
     }
     private final List<ExceptionData> errorMessages;
 

fmlloader/src/main/java/net/minecraftforge/fml/loading/FMLConfig.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -21,6 +21,8 @@ package net.minecraftforge.fml.loading;
 
 import com.electronwill.nightconfig.core.ConfigSpec;
 import com.electronwill.nightconfig.core.file.CommentedFileConfig;
+import com.electronwill.nightconfig.core.file.FileNotFoundAction;
+import com.electronwill.nightconfig.core.io.ParsingException;
 import com.electronwill.nightconfig.core.io.WritingMode;
 import net.minecraftforge.api.distmarker.Dist;
 import org.apache.logging.log4j.LogManager;
@@ -29,6 +31,7 @@ import org.apache.logging.log4j.Logger;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.Arrays;
+import java.util.Objects;
 import java.util.stream.Collectors;
 
 import static net.minecraftforge.fml.loading.LogMarkers.CORE;
@@ -49,12 +52,19 @@ public class FMLConfig
 
     private void loadFrom(final Path configFile)
     {
-        configData = CommentedFileConfig.builder(configFile).sync().
-                defaultResource("/META-INF/defaultfmlconfig.toml").
-                autosave().autoreload().
-                writingMode(WritingMode.REPLACE).
-                build();
-        configData.load();
+        configData = CommentedFileConfig.builder(configFile).sync()
+                .onFileNotFound(FileNotFoundAction.copyData(Objects.requireNonNull(getClass().getResourceAsStream("/META-INF/defaultfmlconfig.toml"))))
+                .autosave().autoreload()
+                .writingMode(WritingMode.REPLACE)
+                .build();
+        try
+        {
+            configData.load();
+        }
+        catch (ParsingException e)
+        {
+            throw new RuntimeException("Failed to load FML config from " + configFile.toString(), e);
+        }
         if (!configSpec.isCorrect(configData)) {
             LOGGER.warn(CORE, "Configuration file {} is not correct. Correcting", configFile);
             configSpec.correct(configData, (action, path, incorrectValue, correctedValue) ->

fmlloader/src/main/java/net/minecraftforge/fml/loading/FMLEnvironment.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -30,6 +30,8 @@ public class FMLEnvironment
 {
     public static final Dist dist = FMLLoader.getDist();
     public static final String naming = FMLLoader.getNaming();
+    public static final boolean production = FMLLoader.isProduction() || System.getProperties().containsKey("production");
+    public static final boolean secureJarsEnabled = FMLLoader.isSecureJarEnabled();
 
     static void setupInteropEnvironment(IEnvironment environment) {
         environment.computePropertyIfAbsent(IEnvironment.Keys.NAMING.get(), v->naming);

fmlloader/src/main/java/net/minecraftforge/fml/loading/FMLLoader.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -20,40 +20,25 @@
 package net.minecraftforge.fml.loading;
 
 import cpw.mods.modlauncher.Launcher;
-import cpw.mods.modlauncher.ServiceLoaderStreamUtils;
-import cpw.mods.modlauncher.TransformingClassLoader;
-import cpw.mods.modlauncher.api.IEnvironment;
-import cpw.mods.modlauncher.api.ILaunchHandlerService;
-import cpw.mods.modlauncher.api.INameMappingService;
-import cpw.mods.modlauncher.api.ITransformationService;
-import cpw.mods.modlauncher.api.ITransformingClassLoader;
-import cpw.mods.modlauncher.api.IncompatibleEnvironmentException;
+import cpw.mods.modlauncher.api.*;
 import cpw.mods.modlauncher.serviceapi.ILaunchPluginService;
+import cpw.mods.modlauncher.util.ServiceLoaderUtils;
 import net.minecraftforge.accesstransformer.service.AccessTransformerService;
 import net.minecraftforge.api.distmarker.Dist;
-import net.minecraftforge.fml.loading.moddiscovery.BackgroundScanHandler;
-import net.minecraftforge.fml.loading.moddiscovery.ModDiscoverer;
-import net.minecraftforge.fml.loading.moddiscovery.ModFile;
+import net.minecraftforge.fml.loading.moddiscovery.*;
 import net.minecraftforge.fml.loading.progress.EarlyProgressVisualization;
 import net.minecraftforge.fml.loading.progress.StartupMessageManager;
+import net.minecraftforge.fml.loading.targets.CommonLaunchHandler;
 import net.minecraftforge.forgespi.Environment;
 import net.minecraftforge.forgespi.coremod.ICoreModProvider;
-import net.minecraftforge.forgespi.locating.IModFile;
 import org.apache.commons.lang3.tuple.Pair;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
-import java.net.URL;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
-import java.util.Optional;
-import java.util.Set;
+import java.util.*;
 import java.util.function.BiFunction;
-import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
 import static net.minecraftforge.fml.loading.LogMarkers.CORE;
@@ -70,20 +55,16 @@ public class FMLLoader
     private static Dist dist;
     private static String naming;
     private static LoadingModList loadingModList;
-    private static TransformingClassLoader launchClassLoader;
     private static RuntimeDistCleaner runtimeDistCleaner;
     private static Path gamePath;
-    private static Path forgePath;
-    private static Path[] mcPaths;
-    static String mcVersion;
-    private static String mcpVersion;
-    static String forgeVersion;
-    private static String forgeGroup;
-    private static Predicate<String> classLoaderExclusions;
+    private static VersionInfo versionInfo;
     private static String launchHandlerName;
-    private static FMLCommonLaunchHandler commonLaunchHandler;
+    private static CommonLaunchHandler commonLaunchHandler;
     public static Runnable progressWindowTick;
+    private static ModValidator modValidator;
     public static BackgroundScanHandler backgroundScanHandler;
+    private static boolean production;
+    private static IModuleLayerManager moduleLayerManager;
 
     static void onInitialLoad(IEnvironment environment, Set<String> otherServices) throws IncompatibleEnvironmentException
     {
@@ -95,8 +76,6 @@ public class FMLLoader
             LOGGER.fatal(CORE,"Found incompatible ModLauncher specification : {}, version {} from {}", modLauncherPackage.getSpecificationVersion(), modLauncherPackage.getImplementationVersion(), modLauncherPackage.getImplementationVendor());
             throw new IncompatibleEnvironmentException("Incompatible modlauncher found "+modLauncherPackage.getSpecificationVersion());
         }
-        LOGGER.debug(CORE, "Initializing modjar URL handler");
-        URL.setURLStreamHandlerFactory(p->p.equals("modjar") ? new ModJarURLHandler() : null);
 
         accessTransformer = (AccessTransformerService) environment.findLaunchPlugin("accesstransformer").orElseThrow(()-> {
             LOGGER.fatal(CORE,"Access Transformer library is missing, we need this to run");
@@ -128,8 +107,7 @@ public class FMLLoader
         });
         LOGGER.debug(CORE, "Found Runtime Dist Cleaner");
 
-        final ArrayList<ICoreModProvider> coreModProviders = new ArrayList<>();
-        ServiceLoaderStreamUtils.errorHandlingServiceLoader(ICoreModProvider.class, serviceConfigurationError -> LOGGER.fatal(CORE, "Failed to load a coremod library, expect problems", serviceConfigurationError)).forEach(coreModProviders::add);
+        var coreModProviders = ServiceLoaderUtils.streamWithErrorHandling(ServiceLoader.load(FMLLoader.class.getModule().getLayer(), ICoreModProvider.class), sce -> LOGGER.fatal(CORE, "Failed to load a coremod library, expect problems", sce)).toList();
 
         if (coreModProviders.isEmpty()) {
             LOGGER.fatal(CORE, "Found no coremod provider. Cannot run");
@@ -158,61 +136,56 @@ public class FMLLoader
             LOGGER.fatal(CORE, "Failed to load NightConfig");
             throw new IncompatibleEnvironmentException("Missing NightConfig");
         }
-        FixSSL.fixup();
     }
 
-    static void setupLaunchHandler(final IEnvironment environment, final Map<String, ?> arguments)
+    static void setupLaunchHandler(final IEnvironment environment, final Map<String, Object> arguments)
     {
         final String launchTarget = environment.getProperty(IEnvironment.Keys.LAUNCHTARGET.get()).orElse("MISSING");
+        arguments.put("launchTarget", launchTarget);
         final Optional<ILaunchHandlerService> launchHandler = environment.findLaunchHandler(launchTarget);
         LOGGER.debug(CORE, "Using {} as launch service", launchTarget);
-        if (!launchHandler.isPresent()) {
+        if (launchHandler.isEmpty()) {
             LOGGER.fatal(CORE,"Missing LaunchHandler {}, cannot continue", launchTarget);
-            throw new RuntimeException("Missing launch handler");
+            throw new RuntimeException("Missing launch handler: " + launchTarget);
         }
 
-        if (!(launchHandler.get() instanceof FMLCommonLaunchHandler)) {
+        if (!(launchHandler.get() instanceof CommonLaunchHandler)) {
             LOGGER.fatal(CORE, "Incompatible Launch handler found - type {}, cannot continue", launchHandler.get().getClass().getName());
             throw new RuntimeException("Incompatible launch handler found");
         }
+        commonLaunchHandler = (CommonLaunchHandler)launchHandler.get();
         launchHandlerName = launchHandler.get().name();
         gamePath = environment.getProperty(IEnvironment.Keys.GAMEDIR.get()).orElse(Paths.get(".").toAbsolutePath());
 
-        commonLaunchHandler = (FMLCommonLaunchHandler)launchHandler.get();
         naming = commonLaunchHandler.getNaming();
         dist = commonLaunchHandler.getDist();
-        progressWindowTick = EarlyProgressVisualization.INSTANCE.accept(dist);
+        production = commonLaunchHandler.isProduction();
+
+        versionInfo = new VersionInfo(arguments);
+
         StartupMessageManager.modLoaderConsumer().ifPresent(c->c.accept("Early Loading!"));
         accessTransformer.getExtension().accept(Pair.of(naming, "srg"));
 
-        mcVersion = (String) arguments.get("mcVersion");
-        mcpVersion = (String) arguments.get("mcpVersion");
-        forgeVersion = (String) arguments.get("forgeVersion");
-        forgeGroup = (String) arguments.get("forgeGroup");
-
-        LOGGER.debug(CORE,"Received command line version data  : MC Version: '{}' MCP Version: '{}' Forge Version: '{}' Forge group: '{}'", mcVersion, mcpVersion, forgeVersion, forgeGroup);
-        forgePath = commonLaunchHandler.getForgePath(mcVersion, forgeVersion, forgeGroup);
-        mcPaths = commonLaunchHandler.getMCPaths(mcVersion, mcpVersion, forgeVersion, forgeGroup);
-
-        commonLaunchHandler.validatePaths(forgePath, mcPaths, forgeVersion, mcVersion, mcpVersion);
-        commonLaunchHandler.setup(environment, arguments);
-        classLoaderExclusions = commonLaunchHandler.getPackagePredicate();
-
-        languageLoadingProvider = new LanguageLoadingProvider();
-        languageLoadingProvider.addForgeLanguage(forgePath);
+        LOGGER.debug(CORE,"Received command line version data  : {}", versionInfo);
 
         runtimeDistCleaner.getExtension().accept(dist);
-        progressWindowTick.run();
     }
-    public static Map<IModFile.Type, List<ModFile>> beginModScan(final Map<String,?> arguments)
+    public static List<ITransformationService.Resource> beginModScan(final Map<String,?> arguments)
     {
         LOGGER.debug(SCAN,"Scanning for Mod Locators");
         modDiscoverer = new ModDiscoverer(arguments);
-        backgroundScanHandler = modDiscoverer.discoverMods();
+        modValidator = modDiscoverer.discoverMods();
+        var pluginResources = modValidator.getPluginResources();
+        return List.of(pluginResources);
+    }
+
+    public static List<ITransformationService.Resource> completeScan(IModuleLayerManager layerManager) {
+        progressWindowTick = EarlyProgressVisualization.INSTANCE.accept(dist, commonLaunchHandler.isData(), versionInfo.mcVersion());
+        moduleLayerManager = layerManager;
+        languageLoadingProvider = new LanguageLoadingProvider();
+        backgroundScanHandler = modValidator.stage2Validation();
         loadingModList = backgroundScanHandler.getLoadingModList();
-        commonLaunchHandler.addLibraries(backgroundScanHandler.getModFiles().getOrDefault(IModFile.Type.LIBRARY, Collections.emptyList()));
-        progressWindowTick.run();
-        return backgroundScanHandler.getModFiles();
+        return List.of(modValidator.getModResources());
     }
 
     public static ICoreModProvider getCoreModProvider() {
@@ -228,10 +201,14 @@ public class FMLLoader
         return modDiscoverer;
     }
 
+    public static CommonLaunchHandler getLaunchHandler() {
+        return commonLaunchHandler;
+    }
+
     public static void addAccessTransformer(Path atPath, ModFile modName)
     {
         LOGGER.debug(SCAN, "Adding Access Transformer in {}", modName.getFilePath());
-        accessTransformer.addResource(atPath, modName.getFileName());
+        accessTransformer.offerResource(atPath, modName.getFileName());
     }
 
     public static Dist getDist()
@@ -239,9 +216,8 @@ public class FMLLoader
         return dist;
     }
 
-    public static void beforeStart(ITransformingClassLoader launchClassLoader)
+    public static void beforeStart(ClassLoader launchClassLoader)
     {
-        FMLLoader.launchClassLoader = (TransformingClassLoader) launchClassLoader.getInstance();
         StartupMessageManager.modLoaderConsumer().ifPresent(c->c.accept("Launching minecraft"));
         progressWindowTick.run();
     }
@@ -251,28 +227,11 @@ public class FMLLoader
         return loadingModList;
     }
 
-    public static TransformingClassLoader getLaunchClassLoader()
-    {
-        return launchClassLoader;
-    }
-
     public static Path getGamePath()
     {
         return gamePath;
     }
 
-    public static Path getForgePath() {
-        return forgePath;
-    }
-
-    public static Path[] getMCPaths() {
-        return mcPaths;
-    }
-
-    public static Predicate<String> getClassLoaderExclusions() {
-        return classLoaderExclusions;
-    }
-
     public static String getNaming() {
         return naming;
     }
@@ -281,10 +240,6 @@ public class FMLLoader
         return Launcher.INSTANCE.environment().findNameMapping(naming);
     }
 
-    public static String getMcpVersion() {
-        return mcpVersion;
-    }
-
     public static String getLauncherInfo() {
         return Launcher.INSTANCE.environment().getProperty(IEnvironment.Keys.MLIMPL_VERSION.get()).orElse("MISSING");
     }
@@ -296,4 +251,20 @@ public class FMLLoader
     public static String launcherHandlerName() {
         return launchHandlerName;
     }
+
+    public static boolean isProduction() {
+        return production;
+    }
+
+    public static boolean isSecureJarEnabled() {
+        return true;
+    }
+
+    public static ModuleLayer getGameLayer() {
+        return moduleLayerManager.getLayer(IModuleLayerManager.Layer.GAME).orElseThrow();
+    }
+
+    public static VersionInfo versionInfo() {
+        return versionInfo;
+    }
 }

fmlloader/src/main/java/net/minecraftforge/fml/loading/FMLPaths.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public

fmlloader/src/main/java/net/minecraftforge/fml/loading/FMLServiceProvider.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -19,35 +19,27 @@
 
 package net.minecraftforge.fml.loading;
 
-import cpw.mods.modlauncher.api.IEnvironment;
-import cpw.mods.modlauncher.api.ITransformationService;
-import cpw.mods.modlauncher.api.ITransformer;
-import cpw.mods.modlauncher.api.IncompatibleEnvironmentException;
+import cpw.mods.modlauncher.api.*;
 import joptsimple.ArgumentAcceptingOptionSpec;
 import joptsimple.OptionSpecBuilder;
 import net.minecraftforge.fml.loading.moddiscovery.ModFile;
 import net.minecraftforge.forgespi.Environment;
-import net.minecraftforge.forgespi.locating.IModFile;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.jetbrains.annotations.NotNull;
 
-import javax.annotation.Nonnull;
-import java.nio.file.Path;
-import java.util.AbstractMap;
 import java.util.ArrayList;
-import java.util.Collection;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 import java.util.function.BiFunction;
-import java.util.stream.Collectors;
-
 import static net.minecraftforge.fml.loading.LogMarkers.CORE;
 
 public class FMLServiceProvider implements ITransformationService
 {
-
     private static final Logger LOGGER = LogManager.getLogger();
     private ArgumentAcceptingOptionSpec<String> modsOption;
     private ArgumentAcceptingOptionSpec<String> modListsOption;
@@ -67,6 +59,12 @@ public class FMLServiceProvider implements ITransformationService
     private String targetForgeGroup;
     private Map<String, Object> arguments;
 
+    public FMLServiceProvider()
+    {
+        final String markerselection = System.getProperty("forge.logging.markers", "");
+        Arrays.stream(markerselection.split(",")).forEach(marker -> System.setProperty("forge.logging.marker." + marker.toLowerCase(Locale.ROOT), "ACCEPT"));
+    }
+
     @Override
     public String name()
     {
@@ -79,6 +77,8 @@ public class FMLServiceProvider implements ITransformationService
         FMLPaths.setup(environment);
         LOGGER.debug(CORE, "Loading configuration");
         FMLConfig.load();
+        LOGGER.debug(CORE, "Preparing ModFile");
+        environment.computePropertyIfAbsent(Environment.Keys.MODFILEFACTORY.get(), k->ModFile.buildFactory());
         arguments = new HashMap<>();
         arguments.put("modLists", modListsArgumentList);
         arguments.put("mods", modsArgumentList);
@@ -95,28 +95,22 @@ public class FMLServiceProvider implements ITransformationService
     }
 
     @Override
-    public void beginScanning(final IEnvironment environment) {
-        throw new IllegalStateException("WHY ARE YOU HERE??????");
+    public List<Resource> beginScanning(final IEnvironment environment) {
+        LOGGER.debug(CORE,"Initiating mod scan");
+        return FMLLoader.beginModScan(arguments);
     }
 
     @Override
-    public List<Map.Entry<String, Path>> runScan(final IEnvironment environment) {
-        LOGGER.debug(CORE,"Initiating mod scan");
-        final Map<IModFile.Type, List<ModFile>> foundFiles = FMLLoader.beginModScan(arguments);
-        return foundFiles
-                .values()
-                .stream()
-                .flatMap(Collection::stream)
-                .map(modFile -> new AbstractMap.SimpleImmutableEntry<>(modFile.getFileName(), modFile.getFilePath()))
-                .collect(Collectors.toList());
+    public List<Resource> completeScan(final IModuleLayerManager layerManager) {
+        return FMLLoader.completeScan(layerManager);
     }
 
     @Override
     public void onLoad(IEnvironment environment, Set<String> otherServices) throws IncompatibleEnvironmentException
     {
-        LOGGER.debug("Injecting tracing printstreams for STDOUT/STDERR.");
-        System.setOut(new TracingPrintStream(LogManager.getLogger("STDOUT"), System.out));
-        System.setErr(new TracingPrintStream(LogManager.getLogger("STDERR"), System.err));
+//        LOGGER.debug("Injecting tracing printstreams for STDOUT/STDERR.");
+//        System.setOut(new TracingPrintStream(LogManager.getLogger("STDOUT"), System.out));
+//        System.setErr(new TracingPrintStream(LogManager.getLogger("STDERR"), System.err));
         FMLLoader.onInitialLoad(environment, otherServices);
     }
 
@@ -146,9 +140,8 @@ public class FMLServiceProvider implements ITransformationService
         targetMcpMappings = option.value(mappingsOption);
     }
 
-    @Nonnull
     @Override
-    public List<ITransformer> transformers()
+    public @NotNull List<ITransformer> transformers()
     {
         LOGGER.debug(CORE, "Loading coremod transformers");
         return new ArrayList<>(FMLLoader.getCoreModProvider().getCoreModTransformers());

fmlloader/src/main/java/net/minecraftforge/fml/loading/FileUtils.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public

fmlloader/src/main/java/net/minecraftforge/fml/loading/JarVersionLookupHandler.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public

fmlloader/src/main/java/net/minecraftforge/fml/loading/LanguageLoadingProvider.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -19,7 +19,9 @@
 
 package net.minecraftforge.fml.loading;
 
-import cpw.mods.modlauncher.ServiceLoaderStreamUtils;
+import cpw.mods.modlauncher.Launcher;
+import cpw.mods.modlauncher.api.IModuleLayerManager;
+import cpw.mods.modlauncher.util.ServiceLoaderUtils;
 import net.minecraftforge.fml.loading.progress.StartupMessageManager;
 import net.minecraftforge.forgespi.language.IModLanguageProvider;
 import net.minecraftforge.fml.loading.moddiscovery.ExplodedDirectoryLocator;
@@ -49,13 +51,12 @@ import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.stream.Stream;
 
-import static cpw.mods.modlauncher.api.LamdbaExceptionUtils.rethrowFunction;
 import static net.minecraftforge.fml.loading.LogMarkers.CORE;
+import static net.minecraftforge.fml.loading.LogMarkers.LOADING;
 
 public class LanguageLoadingProvider
 {
     private static final Logger LOGGER = LogManager.getLogger();
-    private final LanguageClassLoader languageClassLoader;
     private final List<IModLanguageProvider> languageProviders = new ArrayList<>();
     private final ServiceLoader<IModLanguageProvider> serviceLoader;
     private final Map<String, ModLanguageWrapper> languageProviderMap = new HashMap<>();
@@ -71,7 +72,6 @@ public class LanguageLoadingProvider
     }
 
     private static class ModLanguageWrapper {
-
         private final IModLanguageProvider modLanguageProvider;
 
         private final ArtifactVersion version;
@@ -92,26 +92,14 @@ public class LanguageLoadingProvider
 
 
     }
-    private static class LanguageClassLoader extends URLClassLoader
-    {
-        public LanguageClassLoader() {
-            super(new URL[0]);
-        }
 
-        @Override
-        public void addURL(final URL url) {
-            LOGGER.debug(CORE, "Adding {} to languageloader classloader", url);
-            super.addURL(url);
-        }
-
-    }
     LanguageLoadingProvider() {
-        languageClassLoader = new LanguageClassLoader();
-        serviceLoader = ServiceLoader.load(IModLanguageProvider.class, languageClassLoader);
+        var sl = Launcher.INSTANCE.environment().findModuleLayerManager().flatMap(lm->lm.getLayer(IModuleLayerManager.Layer.PLUGIN)).orElseThrow();
+        serviceLoader = ServiceLoader.load(sl, IModLanguageProvider.class);
         loadLanguageProviders();
     }
     private void loadLanguageProviders() {
-        LOGGER.debug(CORE, "Found {} language providers", ServiceLoaderStreamUtils.toList(serviceLoader).size());
+        LOGGER.debug(CORE, "Found {} language providers", ServiceLoaderUtils.streamServiceLoader(()->serviceLoader, sce->LOGGER.fatal("Problem with language loaders")).count());
         serviceLoader.forEach(languageProviders::add);
 
         languageProviders.forEach(lp -> {
@@ -122,7 +110,7 @@ public class LanguageLoadingProvider
                 throw new RuntimeException("Huh?", e);
             }
             Optional<String> implementationVersion = JarVersionLookupHandler.getImplementationVersion(lp.getClass());
-            String impl = implementationVersion.orElse(Files.isDirectory(lpPath) ? FMLLoader.forgeVersion.split("\\.")[0] : null);
+            String impl = implementationVersion.orElse(Files.isDirectory(lpPath) ? FMLLoader.versionInfo().forgeVersion().split("\\.")[0] : null);
             if (impl == null) {
                 LOGGER.fatal(CORE, "Found unversioned language provider {}", lp.name());
                 throw new RuntimeException("Failed to find implementation version for language provider "+ lp.name());
@@ -147,7 +135,7 @@ public class LanguageLoadingProvider
     private void addLanguagePaths(final Stream<Path> langPaths) {
         languageProviders.clear();
         languageProviderMap.clear();
-        langPaths.peek(languagePaths::add).map(Path::toFile).map(File::toURI).map(rethrowFunction(URI::toURL)).forEach(languageClassLoader::addURL);
+//        langPaths.peek(languagePaths::add).map(Path::toFile).map(File::toURI).map(rethrowFunction(URI::toURL)).forEach(languageClassLoader::addURL);
     }
 
     public void addAdditionalLanguages(List<ModFile> modFiles)
@@ -167,11 +155,11 @@ public class LanguageLoadingProvider
         final String languageFileName = mf.getLocator() instanceof ExplodedDirectoryLocator ? "in-development" : mf.getFileName();
         final ModLanguageWrapper mlw = languageProviderMap.get(modLoader);
         if (mlw == null) {
-            LOGGER.error("Missing language {} version {} wanted by {}", modLoader, modLoaderVersion, languageFileName);
+            LOGGER.error(LOADING,"Missing language {} version {} wanted by {}", modLoader, modLoaderVersion, languageFileName);
             throw new EarlyLoadingException("Missing language "+modLoader, null, Collections.singletonList(new EarlyLoadingException.ExceptionData("fml.language.missingversion", modLoader, modLoaderVersion, languageFileName, "null")));
         }
-        if (!modLoaderVersion.containsVersion(mlw.getVersion())) {
-            LOGGER.error("Missing language {} version {} wanted by {}, found {}", modLoader, modLoaderVersion, languageFileName, mlw.getVersion());
+        if (!VersionSupportMatrix.testVersionSupportMatrix(modLoaderVersion, modLoader, "languageloader", (llid, range) -> range.containsVersion(mlw.getVersion()))) {
+            LOGGER.error(LOADING,"Missing language {} version {} wanted by {}, found {}", modLoader, modLoaderVersion, languageFileName, mlw.getVersion());
             throw new EarlyLoadingException("Missing language "+ modLoader + " matching range "+modLoaderVersion + " found "+mlw.getVersion(), null, Collections.singletonList(new EarlyLoadingException.ExceptionData("fml.language.missingversion", modLoader, modLoaderVersion, languageFileName, mlw.getVersion())));
         }
 

fmlloader/src/main/java/net/minecraftforge/fml/loading/LauncherVersion.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public

fmlloader/src/main/java/net/minecraftforge/fml/loading/LibraryFinder.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -36,26 +36,33 @@ public class LibraryFinder {
     private static Path libsPath;
     static Path findLibsPath() {
         if (libsPath == null) {
-            final Path asm = findJarPathFor("org/objectweb/asm/Opcodes.class", "asm");
-            // go up SIX parents to find the libs dir
-            final Path libs = asm.getParent().getParent().getParent().getParent().getParent().getParent();
-            LOGGER.debug(CORE, "Found probable library path {}", libs);
-            libsPath = libs;
+            libsPath = Path.of(System.getProperty("libraryDirectory","crazysnowmannonsense/cheezwhizz"));
+            if (!Files.isDirectory(libsPath)) {
+                throw new IllegalStateException("Missing libraryDirectory system property, cannot continue");
+            }
         }
         return libsPath;
     }
 
+    // Not used anywhere in Forge's codebase, scheduled for deletion unless a good need is expressed.
+    @Deprecated(forRemoval = true, since = "1.17.1")
     public static Path findJarPathFor(final String className, final String jarName) {
         final URL resource = LibraryFinder.class.getClassLoader().getResource(className);
         return findJarPathFor(className, jarName, resource);
     }
 
+    /*
+     * Only used in ClasspathLocator now, so moved too a private method and depreciated this.
+     * Scheduled for deletion unless a good need is expressed.
+     */
+    @Deprecated(forRemoval = true, since = "1.17.1")
     public static Path findJarPathFor(final String resourceName, final String jarName, final URL resource) {
         try {
             Path path;
             final URI uri = resource.toURI();
-            if (uri.getRawSchemeSpecificPart().contains("!")) {
-                path = Paths.get(new URI(uri.getRawSchemeSpecificPart().split("!")[0]));
+            if (uri.getScheme().equals("jar") && uri.getRawSchemeSpecificPart().contains("!/")) {
+                int lastExcl = uri.getRawSchemeSpecificPart().lastIndexOf("!/");
+                path = Paths.get(new URI(uri.getRawSchemeSpecificPart().substring(0, lastExcl)));
             } else {
                 path = Paths.get(new URI("file://"+uri.getRawSchemeSpecificPart().substring(0, uri.getRawSchemeSpecificPart().length()-resourceName.length())));
             }
@@ -79,11 +86,18 @@ public class LibraryFinder {
 
     static Path[] getMCPaths(final String mcVersion, final String mcpVersion, final String forgeVersion, final String forgeGroup, final String type) {
         Path srgMcPath = findLibsPath().resolve(MavenCoordinateResolver.get("net.minecraft", type, "", "srg", mcVersion+"-"+mcpVersion));
-        Path mcExtrasPath = findLibsPath().resolve(MavenCoordinateResolver.get("net.minecraft", type, "", "extra", mcVersion));
+        Path mcExtrasPath = findLibsPath().resolve(MavenCoordinateResolver.get("net.minecraft", type, "", "extra", mcVersion+"-"+mcpVersion));
         Path patchedBinariesPath = findLibsPath().resolve(MavenCoordinateResolver.get(forgeGroup, "forge", "", type, mcVersion+"-"+forgeVersion));
         LOGGER.debug(CORE,"SRG MC at {} is {}", srgMcPath.toString(), pathStatus(srgMcPath));
         LOGGER.debug(CORE,"MC Extras at {} is {}", mcExtrasPath.toString(), pathStatus(mcExtrasPath));
         LOGGER.debug(CORE,"Forge patches at {} is {}", patchedBinariesPath.toString(), pathStatus(patchedBinariesPath));
         return new Path[] { patchedBinariesPath, mcExtrasPath, srgMcPath };
     }
+
+    public static Path findPathForMaven(final String group, final String artifact, final String extension, final String classifier, final String version) {
+        return findLibsPath().resolve(MavenCoordinateResolver.get(group, artifact, extension, classifier, version));
+    }
+    public static Path findPathForMaven(final String maven) {
+        return findLibsPath().resolve(MavenCoordinateResolver.get(maven));
+    }
 }

fmlloader/src/main/java/net/minecraftforge/fml/loading/LoadingModList.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -19,20 +19,16 @@
 
 package net.minecraftforge.fml.loading;
 
-import com.google.common.collect.Streams;
+import cpw.mods.modlauncher.api.LamdbaExceptionUtils;
 import net.minecraftforge.fml.loading.moddiscovery.BackgroundScanHandler;
 import net.minecraftforge.fml.loading.moddiscovery.ModFile;
 import net.minecraftforge.fml.loading.moddiscovery.ModFileInfo;
 import net.minecraftforge.fml.loading.moddiscovery.ModInfo;
 
-import java.net.MalformedURLException;
 import java.net.URL;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 import java.util.stream.Collectors;
 
 /**
@@ -45,7 +41,6 @@ public class LoadingModList
     private final List<ModFileInfo> modFiles;
     private final List<ModInfo> sortedList;
     private final Map<String, ModFileInfo> fileById;
-    private BackgroundScanHandler scanner;
     private final List<EarlyLoadingException> preLoadErrors;
     private List<ModFile> brokenFiles;
 
@@ -97,7 +92,6 @@ public class LoadingModList
 
     public void addForScanning(BackgroundScanHandler backgroundScanHandler)
     {
-        this.scanner = backgroundScanHandler;
         backgroundScanHandler.setLoadingModList(this);
         modFiles.stream()
                 .map(ModFileInfo::getFile)
@@ -118,21 +112,46 @@ public class LoadingModList
         return null;
     }
 
-    public URL findURLForResource(String resourceName) {
-        for (ModFileInfo mf : modFiles) {
-            // strip a leading slash
-            if (resourceName.startsWith("/")) resourceName = resourceName.substring(1);
-
-            final Path resource = mf.getFile().findResource(resourceName);
-            if (Files.exists(resource)) {
-                try {
-                    return new URL("modjar://"+mf.getMods().get(0).getModId()+"/"+resourceName);
-                } catch (MalformedURLException e) {
-                    throw new RuntimeException(e);
-                }
-            }
+    public Enumeration<URL> findAllURLsForResource(final String resName) {
+        final String resourceName;
+        // strip a leading slash
+        if (resName.startsWith("/")) {
+            resourceName = resName.substring(1);
+        } else {
+            resourceName = resName;
         }
-        return null;
+        return new Enumeration<URL>() {
+            private final Iterator<ModFileInfo> modFileIterator = modFiles.iterator();
+            private URL next;
+            @Override
+            public boolean hasMoreElements() {
+                if (next!=null) return true;
+                next = findNextURL();
+                return next != null;
+            }
+
+            @Override
+            public URL nextElement() {
+                if (next == null) {
+                    next = findNextURL();
+                    if (next == null) throw new NoSuchElementException();
+                }
+                URL result = next;
+                next = null;
+                return result;
+            }
+
+            private URL findNextURL() {
+                while (modFileIterator.hasNext()) {
+                    final ModFileInfo next = modFileIterator.next();
+                    final Path resource = next.getFile().findResource(resourceName);
+                    if (Files.exists(resource)) {
+                        return LamdbaExceptionUtils.uncheck(()->new URL("modjar://" + next.getMods().get(0).getModId() + "/" + resourceName));
+                    }
+                }
+                return null;
+            }
+        };
     }
 
     public ModFileInfo getModFileById(String modid)

fmlloader/src/main/java/net/minecraftforge/fml/loading/LogMarkers.java

@@ -1,6 +1,6 @@
 /*
  * Minecraft Forge
- * Copyright (c) 2016-2019.
+ * Copyright (c) 2016-2021.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -27,5 +27,4 @@ public class LogMarkers {
     public static final Marker LOADING = MarkerManager.getMarker("LOADING");
     public static final Marker SCAN = MarkerManager.getMarker("SCAN");
     public static final Marker SPLASH = MarkerManager.getMarker("SPLASH");
-    public static final Marker FORGEMOD = MarkerManager.getMarker("FORGEMOD").addParents(LOADING);
 }