Update license headers to compact SPDX format.

License has not changed, this is just more compact and doesn't include years. Bump version for RB.
Remove - from allowed characters in mod ids.
2026-11-14 09:05:17 +00:00 · 2022-02-28 13:41:23 -08:00 · 2022-02-28 13:23:53 -08:00 · 2022-02-28 22:03:31 +01:00 · 2022-02-28 17:23:19 +00:00 · 2022-02-25 01:06:32 +00:00
2375 changed files with 63239 additions and 57512 deletions
@@ -9,19 +9,24 @@

 #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/
@@ -32,6 +37,7 @@ src/generated/resources/.cache/
 #Patch rejects
 /patches-/
 *.patch.rej
+/projects/*/rejects/

 # FML changelog
 changelog.txt
@@ -39,10 +45,3 @@ changelog.txt
 *.7z
 /logs/

-gradle.properties
-!/mdk/gradle.properties
-/projects/forge/rejects/
-
-# Srg2Source causes import bugs on these patches. If you intentionnally change these, remove the ignore.
-/patches/minecraft/net/minecraft/client/renderer/ViewFrustum.java.patch
-/patches/minecraft/net/minecraft/data/BlockModelDefinition.java.patch
@@ -0,0 +1,104 @@
+<?xml version="1.0"?>
+<project>
+  <modelVersion>4.0.0</modelVersion>
+  <name>MinecraftForge_Forge Config DSL Script</name>
+  <groupId>MinecraftForge_Forge</groupId>
+  <artifactId>MinecraftForge_Forge_dsl</artifactId>
+  <version>1.0-SNAPSHOT</version>
+
+  <parent>
+    <groupId>org.jetbrains.teamcity</groupId>
+    <artifactId>configs-dsl-kotlin-parent</artifactId>
+    <version>1.0-SNAPSHOT</version>
+  </parent>
+
+  <repositories>
+    <repository>
+      <id>jetbrains-all</id>
+      <url>https://download.jetbrains.com/teamcity-repository</url>
+      <snapshots>
+        <enabled>true</enabled>
+      </snapshots>
+    </repository>
+    <repository>
+      <id>teamcity-server</id>
+      <url>https://teamcity.minecraftforge.net/app/dsl-plugins-repository</url>
+      <snapshots>
+        <enabled>true</enabled>
+      </snapshots>
+    </repository>
+  </repositories>
+
+  <pluginRepositories>
+    <pluginRepository>
+      <id>JetBrains</id>
+      <url>https://download.jetbrains.com/teamcity-repository</url>
+    </pluginRepository>
+  </pluginRepositories>
+
+  <build>
+    <sourceDirectory>${basedir}</sourceDirectory>
+    <plugins>
+      <plugin>
+        <artifactId>kotlin-maven-plugin</artifactId>
+        <groupId>org.jetbrains.kotlin</groupId>
+        <version>${kotlin.version}</version>
+
+        <configuration/>
+        <executions>
+          <execution>
+            <id>compile</id>
+            <phase>process-sources</phase>
+            <goals>
+              <goal>compile</goal>
+            </goals>
+          </execution>
+          <execution>
+            <id>test-compile</id>
+            <phase>process-test-sources</phase>
+            <goals>
+              <goal>test-compile</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+      <plugin>
+        <groupId>org.jetbrains.teamcity</groupId>
+        <artifactId>teamcity-configs-maven-plugin</artifactId>
+        <version>${teamcity.dsl.version}</version>
+        <configuration>
+          <format>kotlin</format>
+          <dstDir>target/generated-configs</dstDir>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.jetbrains.teamcity</groupId>
+      <artifactId>configs-dsl-kotlin</artifactId>
+      <version>${teamcity.dsl.version}</version>
+      <scope>compile</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.jetbrains.teamcity</groupId>
+      <artifactId>configs-dsl-kotlin-plugins</artifactId>
+      <version>1.0-SNAPSHOT</version>
+      <type>pom</type>
+      <scope>compile</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.jetbrains.kotlin</groupId>
+      <artifactId>kotlin-stdlib-jdk8</artifactId>
+      <version>${kotlin.version}</version>
+      <scope>compile</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.jetbrains.kotlin</groupId>
+      <artifactId>kotlin-script-runtime</artifactId>
+      <version>${kotlin.version}</version>
+      <scope>compile</scope>
+    </dependency>
+  </dependencies>
+</project>
@@ -0,0 +1,136 @@
+import jetbrains.buildServer.configs.kotlin.v2019_2.*
+import jetbrains.buildServer.configs.kotlin.v2019_2.projectFeatures.githubIssues
+
+/*
+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)
+
+    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", label = "Gradle version", description = "The version of Gradle to use during execution of Gradle tasks.", display = ParameterDisplay.HIDDEN, allowEmpty = false)
+        text("git_main_branch", "1.18.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_FML_ARTIFACT_ID", "fmlonly", label = "Published fmlonly artifact id", description = "The maven coordinate artifact id for fml only that has been published by this build. Can not be empty.", allowEmpty = false)
+        text("env.PUBLISHED_JAVA_FML_ARTIFACT_VERSION", "0.0.0-SNAPSHOT", label = "Published fmlonly artifact version", description = "The version for fml only 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.KEYSTORE_URL", "credentialsJSON:a7ae1c82-8058-4061-8d12-7f6bc2618d2e", display = ParameterDisplay.HIDDEN)
+        password("env.KEYSTORE_PASSWORD", "credentialsJSON:d7b964e3-a1fd-47a8-b892-6f601fe47479", display = ParameterDisplay.HIDDEN)
+        text("additional_publishing_gradle_parameters", "-PcrowdinKey=%env.CROWDIN_KEY% -PkeystoreKeyPass=%env.KEYSTORE_PASSWORD% -PkeystoreStorePass=%env.KEYSTORE_PASSWORD% -Pkeystore=%env.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."
+
+    features {
+        feature {
+            id = "trigger_fml_only_files_generator"
+            type = "triggerBuildFeature"
+            param("triggers", "MinecraftForge_FilesGenerator_GeneratePages")
+            param("parameters", """
+                env.PUBLISHED_JAVA_FML_ARTIFACT_ID~env.PUBLISHED_JAVA_ARTIFACT_ID
+                env.PUBLISHED_JAVA_FML_ARTIFACT_VERSION~env.PUBLISHED_JAVA_ARTIFACT_VERSION
+                env.PUBLISHED_JAVA_GROUP
+            """.trimIndent())
+        }
+    }
+})
+
+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
+        )
+    }
+
+    vcs {
+        branchFilter = """
+            +:*
+            -:1.*
+            -:<default>
+        """.trimIndent()
+    }
+})
@@ -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}'
+                }
            }
        }
    }
@@ -1,16 +1,2 @@
-Minecraft Forge
-Copyright (c) 2016-2020.
-
-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
+Minecraft Forge - Forge Development LLC
+SPDX-License-Identifier: LGPL-2.1-only
@@ -1,2 +1,3 @@
 /.gradle/
 /build/
+/out/
@@ -1,10 +1,9 @@
 repositories {
-	//mavenCentral() //TODO: Update Gradle to use HTTPS by default
-	maven {
-		name 'maven_central'
-		url 'https://repo.maven.apache.org/maven2/'
-	}
+    maven { url = 'https://maven.minecraftforge.net/' }
+	mavenCentral()
 }
 dependencies {
-	implementation 'org.ow2.asm:asm:7.2'
+	implementation 'org.ow2.asm:asm:9.1'
+	implementation 'org.ow2.asm:asm-tree:9.1'
+    implementation 'net.minecraftforge:srgutils:0.4.+'
 }
@@ -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()
+}
@@ -1,20 +1,24 @@
 package net.minecraftforge.forge.tasks

-import java.util.ArrayList
-import java.util.TreeMap
+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

-public class CheckATs extends DefaultTask {
-	@InputFile File inheritance
-	@InputFiles File[] ats
+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('#')
@@ -41,7 +45,7 @@ public class CheckATs extends DefaultTask {
 				default:          return -1
 			}
 		}
-		def json = inheritance.json()
+		def json = inheritance.get().asFile.json()
 		
 		ats.each { f -> 
 			TreeMap lines = [:]
@@ -51,12 +55,12 @@ public class CheckATs extends DefaultTask {
 				if (line.startsWith('#group ')) {
 					def (modifier, cls, desc, comment, key) = parse.call(line.substring(7))
 					
-					if (!desc.equals('*') && !desc.equals('*()') && !desc.equals('<init>'))
+					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,
+						existing: [] as Set,
+						children: [] as TreeSet,
 						group: true
 					]
 					if (lines.containsKey(key))
@@ -93,7 +97,7 @@ public class CheckATs extends DefaultTask {
 					if (jcls == null) {
 						lines.remove(key)
 						println('Invalid Group: ' + key)
-					} else if ('*'.equals(entry['desc'])) {
+					} else if ('*' == entry['desc']) {
 						if (!jcls.containsKey('fields')) {
 							lines.remove(key)
 							println('Invalid Group, Class has no fields: ' + key)
@@ -114,13 +118,13 @@ public class CheckATs extends DefaultTask {
 							}
 							entry['existing'].stream().findAll{ !entry['children'].contains(it) }.each{ println('Removed: ' + it) }
 						}
-					} else if ('*()'.equals(entry['desc'])) {
+					} 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>'))
+								if (mtd.startsWith('<clinit>') || mtd.startsWith('lambda$'))
 									return
 								key = cls + ' ' + mtd.replace(' ', '')
 								if (accessLevel.call(value['access']) < accessStr.call(entry['modifier'])) {
@@ -137,7 +141,7 @@ public class CheckATs extends DefaultTask {
 							}
 							entry['existing'].stream().findAll{ !entry['children'].contains(it) }.each{ println('Removed: ' + it) }
 						}
-					} else if ('<init>'.equals(entry['desc'])) { //Make all public non-abstract subclasses 
+					} 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
@@ -182,7 +186,7 @@ public class CheckATs extends DefaultTask {
 						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 '))) {
+						if (accessLevel.call(jcls['access']) > accessStr.call(entry['modifier']) && (entry.comment == null || !entry.comment.startsWith('#force '))) {
 							lines.remove(key)
 							println('Invalid Narrowing: ' + key)
 						}
@@ -192,7 +196,7 @@ public class CheckATs extends DefaultTask {
 							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 '))) {
+							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)
@@ -205,7 +209,7 @@ public class CheckATs extends DefaultTask {
 							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 '))) {
+							if (accessLevel.call(value['access']) > accessStr.call(entry['modifier']) && (entry.comment == null || !entry.comment.startsWith('#force '))) {
 								lines.remove(key)
 								println('Invalid Narrowing: ' + key)
 							}
@@ -216,12 +220,44 @@ public class CheckATs extends DefaultTask {

 			
 			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) {
-					data.add(value.modifier + ' ' + key + (value.comment == null ? '' : ' ' + value.comment))
+                    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{ data.add(value.modifier + ' ' + it) }
+					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')
 				}
 			}
@@ -1,7 +1,7 @@
 package net.minecraftforge.forge.tasks

-import java.util.ArrayList
-import java.util.TreeMap
+import org.gradle.api.file.ConfigurableFileCollection
+import org.gradle.api.file.RegularFileProperty

 import org.gradle.api.DefaultTask
 import org.gradle.api.tasks.InputFile
@@ -17,17 +17,17 @@ import org.objectweb.asm.Type
 import java.util.zip.ZipEntry
 import java.util.zip.ZipInputStream

-public class CheckExcs extends DefaultTask {
-	@InputFile File binary
-	@InputFiles File[] excs
+abstract class CheckExcs extends DefaultTask {
+	@InputFile abstract RegularFileProperty getBinary()
+	@InputFiles abstract ConfigurableFileCollection getExcs()
 	
    @TaskAction
    protected void exec() {
 		Util.init()
 		def known = []
-		binary.withInputStream { i -> 
+		binary.get().asFile.withInputStream { i ->
 			new ZipInputStream(i).withCloseable { zin ->
-				def visitor = new ClassVisitor(Opcodes.ASM7) {
+				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) {
@@ -68,8 +68,7 @@ public class CheckExcs extends DefaultTask {
 				
 				def (key, value) = line.split('=', 2)
 				if (!known.contains(key)) {
-					println(key)
-					println('Invalid: ' + line)
+					println('Unknown: ' + line)
 					return
 				}
 				
@@ -1,6 +1,7 @@
 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
@@ -9,19 +10,19 @@ import java.nio.file.Files
 import java.nio.file.Paths
 import java.util.regex.Pattern

-public class CheckPatches extends DefaultTask {
-    @InputDirectory File patchDir
+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/ViewFrustum.java.patch"),
-            Paths.get("patches/minecraft/net/minecraft/data/BlockModelDefinition.java.patch")
+                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;
-        project.fileTree(patchDir).each { patch ->
+        patchDir.get().asFileTree.each { patch ->
            def patchPath = project.rootDir.toPath().relativize(patch.toPath())
            verified &= verifyPatch(patch, autoFix, patchPath.toString(), hasS2SArtifact.contains(patchPath))
        }
@@ -31,7 +32,7 @@ public class CheckPatches extends DefaultTask {
    }

    def verifyPatch(patch, fix, patchPath, hasS2SArtifact) {
-        def hunk_start_pattern = Pattern.compile('^@@ -[0-9,]* \\+[0-9,]* @@$')
+        def hunk_start_pattern = Pattern.compile('^@@ -[0-9,]* \\+[0-9,_]* @@$')
        def white_space_pattern = Pattern.compile('^[+\\-]\\s*$')
        def import_pattern = Pattern.compile('^[+\\-]\\s*import.*')
        def field_pattern = Pattern.compile('^[+\\-][\\s]*((public|protected|private)[\\s]*)?(static[\\s]*)?(final)?([^=;]*)(=.*)?;\\s*$')
@@ -1,22 +1,21 @@
 package net.minecraftforge.forge.tasks

-import java.util.ArrayList
-import java.util.TreeMap
+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.Opcodes

-public class CheckSAS extends DefaultTask {
-	@InputFile File inheritance
-	@InputFiles File[] sass
+abstract class CheckSAS extends DefaultTask {
+	@InputFile abstract RegularFileProperty getInheritance()
+	@InputFiles abstract ConfigurableFileCollection getSass()
 	
    @TaskAction
    protected void exec() {
 		Util.init()
-		def json = inheritance.json()
+		def json = inheritance.get().asFile.json()
 		
 		sass.each { f -> 
 			def lines = []
@@ -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
+    }
+}
@@ -1,47 +1,55 @@
 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.TaskAction
 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
-import java.net.URL

-public class CrowdinTask extends DefaultTask {
-    @Input String id = 'minecraft-forge'
-	@Input @Optional String key
+abstract class Crowdin extends DefaultTask {
+    @Input abstract Property<String> getId()
+	@Input @Optional abstract Property<String> getKey()
 	@Input boolean json = true
-	@OutputFile output = project.file("build/${name}/output.zip")
-	@OutputFile export = project.file("build/${name}/export.json")
-	
-	CrowdinTask() {
+	@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() {
-		if (output.exists())
-			output.delete()
+		File outputFile = output.get().asFile
+		File exportFile = export.get().asFile
+		if (outputFile.exists())
+			outputFile.delete()
 		
-		if (key == null)
+		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 -> 
-			export.withOutputStream { it << i }
+		new URL("https://api.crowdin.com/api/project/${id}/export?key=${key}").withInputStream { i ->
+			exportFile.withOutputStream { it << i }
 		}
 		
-		if (!export.text.contains('success')) {
-			throw new RuntimeException("Crowdin export failed, see ${export} for more info")
+		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 ->
-				output.withOutputStream { out ->
+				outputFile.withOutputStream { out ->
 					new ZipOutputStream(out).withCloseable { zout -> 
 						ZipEntry zein
 						while ((zein = zin.nextEntry) != null) {
@@ -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 ${target.canonicalPath} SHA Mismatch")
+					}
+				}
+			}
+		}
+        Files.write(librariesOutput.get().asFile.toPath(), libraries)
+    }
+}
@@ -1,43 +0,0 @@
-package net.minecraftforge.forge.tasks
-
-import org.gradle.api.DefaultTask
-import org.gradle.api.tasks.InputFile
-import org.gradle.api.tasks.TaskAction
-import org.gradle.api.tasks.OutputDirectory
-
-import java.io.File
-import java.util.HashSet
-import java.util.Set
-import java.net.URL
-
-public class DownloadLibrariesTask extends DefaultTask {
-    @InputFile File input
-	@OutputDirectory File output = project.file("build/${name}/")
-	Set<File> libraries = new HashSet<>()
-
-    @TaskAction
-    def run() {
-		Util.init()
-		
-		def json = input.json().libraries.each { lib ->
-		    //TODO: Thread?
-			def artifacts = [lib.downloads.artifact] + lib.downloads.get('classifiers', [:]).values()
-			artifacts.each{ art -> 
-				def target = new File(output, art.path)
-				libraries.add(target)
-				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")
-					}
-				}
-			}
-		}
-    }
-}
@@ -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)
+        })
+    }
+}
@@ -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 + '/'
+                    }
+                }
+            }
+        }
+    }
+}
@@ -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/${path}",
+                        sha1: child.archiveFile.get().asFile.sha1(),
+                        size: child.archiveFile.get().asFile.length()
+                    ]
+                ]
+            ])
+        }
+        json.libraries = libs.values().sort{a,b -> a.name.compareTo(b.name)}
+        json.icon = "data:image/png;base64," + new String(Base64.getEncoder().encode(Files.readAllBytes(icon.get().asFile.toPath())))
+        json.json = launcherJsonName.get()
+        json.logo = logo.get()
+        if (!mirrors.get().isEmpty())
+            json.mirrorList = mirrors.get()
+        json.welcome = welcome.get()
+
+        Files.writeString(output.get().getAsFile().toPath(), new JsonBuilder(json).toPrettyString())
+    }
+}
@@ -0,0 +1,74 @@
+package net.minecraftforge.forge.tasks
+
+import groovy.json.JsonBuilder
+import org.gradle.api.DefaultTask
+import org.gradle.api.file.ConfigurableFileCollection
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.provider.SetProperty
+import org.gradle.api.tasks.*
+
+import java.nio.file.Files
+
+import static net.minecraftforge.forge.tasks.Util.getArtifacts
+import static net.minecraftforge.forge.tasks.Util.iso8601Now
+
+abstract class LauncherJson extends DefaultTask {
+    @OutputFile abstract RegularFileProperty getOutput()
+    @InputFiles abstract ConfigurableFileCollection getInput()
+    @Input Map<String, Object> json = new LinkedHashMap<>()
+    @Input @Optional abstract SetProperty<String> getPackedDependencies()
+    
+    @Internal final vanilla = project.project(':mcp').file('build/mcp/downloadJson/version.json')
+    @Internal final timestamp = iso8601Now()
+    @Internal final comment = [
+        "Please do not automate the download and installation of Forge.",
+        "Our efforts are supported by ads from the download page.",
+        "If you MUST automate this, please consider supporting the project through https://www.patreon.com/LexManos/"
+    ]
+    @Internal final id = "${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())
+    }
+}
@@ -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())
+    }
+}
@@ -1,5 +1,6 @@
 package net.minecraftforge.forge.tasks

+import groovy.json.JsonBuilder
 import groovy.json.JsonSlurper

 import java.io.File
@@ -16,14 +17,29 @@ public class Util {
 			}
 			return md.digest().collect {String.format "%02x", it}.join()
 		}
+        File.metaClass.getSha1 = { !delegate.exists() ? null : delegate.sha1() }
 	
 		File.metaClass.json = { -> new JsonSlurper().parseText(delegate.text) }
+        File.metaClass.getJson = { return delegate.exists() ? new JsonSlurper().parse(delegate) : [:] }
+        File.metaClass.setJson = { json -> delegate.text = new JsonBuilder(json).toPrettyString() }
 		
 		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) {
@@ -56,14 +72,15 @@ public class Util {
 			def path = "${folder}${filename}"
 			def url = "https://libraries.minecraft.net/${path}"
 			if (!checkExists(url)) {
-				url = "https://files.minecraftforge.net/maven/${path}"
+				url = "https://maven.minecraftforge.net/${path}"
 			}
 			//TODO remove when Mojang launcher is updated
-			if (!classifiers && art.classifier != null) { //Mojang launcher doesn't currently support classifiers, so... move it to part of the version, and force the extension to 'jar'
+			if (!classifiers && art.classifier != null) { 
+				//Mojang launcher doesn't currently support classifiers, so... move it to part of the version, and force the extension to 'jar'
+				// However, keep the path normal so that our mirror system works.
 				art.version = "${art.version}-${art.classifier}"
 				art.classifier = null
 				art.extension = 'jar'
-				path = "${art.group.replace('.', '/')}/${art.name}/${art.version}/${art.name}-${art.version}.jar"
 			}
 			ret[key] = [
 				name: "${art.group}:${art.name}:${art.version}" + (art.classifier == null ? '' : ":${art.classifier}") + (art.extension == 'jar' ? '' : "@${art.extension}"),
@@ -79,6 +96,17 @@ public class Util {
 		}
 		return ret
 	}
+    
+    public static def getMavenPath(task) {        
+        def classifier = task.archiveClassifier.get()
+        def dep = "${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() }

@@ -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.
@@ -2,16 +2,16 @@

 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=1.16.3-&query=$.promos["1.16.3-recommended"]&color=brightgreen&logo=data:image/svg+xml;base64,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)](https://files.minecraftforge.net)
-[![Latest Release](https://img.shields.io/badge/dynamic/json?url=https://files.minecraftforge.net/maven/net/minecraftforge/forge/promotions_slim.json&label=Latest&prefix=1.16.3-&query=$.promos["1.16.3-latest"]&color=blue&logo=data:image/svg+xml;base64,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
+[![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    |
 | ------------- | ------------- |
-| 1.16.x  | Active  |
-| 1.15.x  | LTS  |
+|    1.17.x     |    Active     |
+|    1.16.x     |    LTS        |

 * [Download]
 * [Forum]
@@ -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
+}
@@ -0,0 +1,35 @@
+package net.minecraftforge.fml;
+
+import cpw.mods.modlauncher.util.ServiceLoaderUtils;
+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();
+    }
+}
@@ -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);
+    }
+}
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -21,29 +21,26 @@ package net.minecraftforge.fml;

 import static net.minecraftforge.fml.Logging.LOADING;

-import java.util.*;
+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 net.minecraftforge.fml.event.lifecycle.ParallelDispatchEvent;
-import org.apache.commons.lang3.time.StopWatch;
+import com.google.common.base.Stopwatch;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;

-import com.google.common.base.Stopwatch;
-
-import net.minecraftforge.forgespi.language.IModInfo;
-
 /**
 * 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, {@link IThreadListener} should be used instead.
+ * 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.
@@ -52,32 +49,39 @@ public class DeferredWorkQueue
 {
    private static final Logger LOGGER = LogManager.getLogger();

-    private static Map<Class<? extends ParallelDispatchEvent>, DeferredWorkQueue> workQueues = new HashMap<>();
+    private static final Map<ModLoadingStage, DeferredWorkQueue> workQueues = new HashMap<>();

-    private final ModLoadingStage modLoadingStage;
    private final ConcurrentLinkedDeque<TaskInfo> tasks = new ConcurrentLinkedDeque<>();
+    private final ModLoadingStage modLoadingStage;

-    public DeferredWorkQueue(final ModLoadingStage modLoadingStage, Class<? extends ParallelDispatchEvent> eventClass) {
+    public DeferredWorkQueue(ModLoadingStage modLoadingStage) {
        this.modLoadingStage = modLoadingStage;
-        workQueues.put(eventClass, this);
+        workQueues.put(modLoadingStage, this);
    }

-    public static Optional<DeferredWorkQueue> lookup(Optional<Class<? extends ParallelDispatchEvent>> parallelClass) {
+    @SuppressWarnings("OptionalUsedAsFieldOrParameterType")
+    public static Optional<DeferredWorkQueue> lookup(Optional<ModLoadingStage> parallelClass) {
        return Optional.ofNullable(workQueues.get(parallelClass.orElse(null)));
    }

-    void runTasks() {
+    public void runTasks() {
        if (tasks.isEmpty()) return;
-        LOGGER.debug(LOADING, "Dispatching synchronous work after {}: {} jobs", modLoadingStage, tasks.size());
-        StopWatch globalTimer = StopWatch.createStarted();
+        LOGGER.debug(LOADING, "Dispatching synchronous work for work queue {}: {} jobs", modLoadingStage, tasks.size());
+        Stopwatch timer = Stopwatch.createStarted();
        tasks.forEach(t->makeRunnable(t, Runnable::run));
-        LOGGER.debug(LOADING, "Synchronous work queue completed in {}", globalTimer);
+        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();
-            ti.task.run();
+            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);
@@ -85,36 +89,13 @@ public class DeferredWorkQueue
        });
    }

-    public CompletableFuture<Void> enqueueWork(final IModInfo modInfo, final Runnable work) {
+    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 IModInfo modInfo, final Supplier<T> work) {
+    public <T> CompletableFuture<T> enqueueWork(final ModContainer modInfo, final Supplier<T> work) {
        return CompletableFuture.supplyAsync(work, r->tasks.add(new TaskInfo(modInfo, r)));
    }

-    /**
-     * DEPRECATED FOR REMOVAL. Use {@link ParallelDispatchEvent#enqueueWork(Runnable)} or {@link ParallelDispatchEvent#enqueueWork(Supplier)}
-     *
-     * @param workToEnqueue Runnable to execute later
-     * @return a completable future
-     */
-    @Deprecated
-    public static CompletableFuture<Void> runLater(Runnable workToEnqueue) {
-        return
-                Optional.ofNullable(ModLoadingContext.get().getActiveContainer().modLoadingStage.getDeferredWorkQueue())
-                .map(wq->wq.enqueueWork(ModLoadingContext.get().getActiveContainer().modInfo, workToEnqueue))
-                .orElseGet(()->CompletableFuture.completedFuture(null));
-    }
-
-    static class TaskInfo
-    {
-        public final IModInfo owner;
-        public final Runnable task;
-
-        private TaskInfo(IModInfo owner, Runnable task) {
-            this.owner = owner;
-            this.task = task;
-        }
-    }
+    record TaskInfo(ModContainer owner, Runnable task) {}
 }
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -46,7 +46,7 @@ public final class DistExecutor
    private DistExecutor() {}

    /**
-     * Run the callable in the supplier only on the specified {@link Side}.
+     * 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.
     *
@@ -0,0 +1,6 @@
+package net.minecraftforge.fml;
+
+public interface I18NParser {
+    String parseMessage(String i18nMessage, Object... args);
+    String stripControlCodes(String toStrip);
+}
@@ -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();
+}
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -19,60 +19,44 @@

 package net.minecraftforge.fml;

-import java.util.function.BiFunction;
 import java.util.function.BiPredicate;
 import java.util.function.Supplier;

-import org.apache.commons.lang3.tuple.Pair;
-
-import net.minecraft.client.Minecraft;
-import net.minecraft.client.gui.screen.Screen;
-import net.minecraft.resources.IResourcePack;
-import net.minecraftforge.fml.packs.ModFileResourcePack;
-
-public class ExtensionPoint<T>
+public interface IExtensionPoint<T extends Record>
 {
-    public static final ExtensionPoint<BiFunction<Minecraft, Screen, Screen>> CONFIGGUIFACTORY = new ExtensionPoint<>();
-    public static final ExtensionPoint<BiFunction<Minecraft, ModFileResourcePack, IResourcePack>> RESOURCEPACK = new ExtensionPoint<>();
    /**
     * 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)
+     * The supplier provides my "local" version for sending across the impl or writing to disk
+     * The predicate tests the version from a remote instance or save for acceptability (Boolean is true for impl, false for local save)
     * and returns true if the version is compatible.
     *
-     * <p>Return {@link net.minecraftforge.fml.network.FMLNetworkConstants#IGNORESERVERONLY} in the supplier, if you wish to be ignored
+     * <p>Return {@code net.minecraftforge.impl.impl.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,
+     * <p>Return true in the predicate for all values of the input string (when impl 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
-     *
-     * <code><pre>
+     * </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></code>
-     * </p>
+     * }</pre>
+     *
     * <p>
     * Examples: A client only mod
-     * <code><pre>
+     * </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></code>
-     * </p>
+     * }</pre>
     *
     */
-    public static final ExtensionPoint<Pair<Supplier<String>, BiPredicate<String, Boolean>>> DISPLAYTEST = new ExtensionPoint<>();
-
-    private Class<T> type;
-
-    private ExtensionPoint() {
-    }
-
+    record DisplayTest(Supplier<String> suppliedVersion, BiPredicate<String, Boolean> remoteVersionTest) implements IExtensionPoint<DisplayTest> {}
 }
@@ -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);
+}
@@ -0,0 +1,7 @@
+package net.minecraftforge.fml;
+
+import java.util.List;
+
+public interface IModStateProvider {
+    List<IModLoadingState> getAllStates();
+}
@@ -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());
+    }
+}
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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();
 }
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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;
        }
    }

@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -31,6 +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
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -20,10 +20,10 @@
 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.lifecycle.IModBusEvent;
+import net.minecraftforge.fml.event.IModBusEvent;
 import net.minecraftforge.forgespi.language.IModInfo;
-import org.apache.commons.lang3.tuple.Pair;

 import java.util.EnumMap;
 import java.util.HashMap;
@@ -58,10 +58,10 @@ public abstract class ModContainer
    protected ModLoadingStage modLoadingStage;
    protected Supplier<?> contextExtension;
    protected final Map<ModLoadingStage, Runnable> activityMap = new HashMap<>();
-    protected final Map<ExtensionPoint, Supplier<?>> extensionPoints = new IdentityHashMap<>();
+    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)
    {
@@ -71,7 +71,7 @@ public abstract class ModContainer
        this.modInfo = info;
        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())));
    }

@@ -111,35 +111,32 @@ public abstract class ModContainer

    public static <T extends Event & IModBusEvent> CompletableFuture<Void> buildTransitionHandler(
            final ModContainer target,
-            final ModLoadingStage.EventGenerator<T> eventGenerator,
+            final IModStateTransition.EventGenerator<T> eventGenerator,
            final BiFunction<ModLoadingStage, Throwable, ModLoadingStage> stateChangeHandler,
            final Executor executor) {
        return CompletableFuture
                .runAsync(() -> {
-                    ModLoadingContext.get().setActiveContainer(target, target.contextExtension.get());
+                    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, null);
+                    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);
    }
@@ -148,7 +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));
    }

@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * Copyright (c) 2016-2022.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
@@ -20,11 +20,14 @@
 package net.minecraftforge.fml;

 import net.minecraftforge.eventbus.api.Event;
-import net.minecraftforge.fml.event.lifecycle.IModBusEvent;
+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.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;

@@ -34,6 +37,7 @@ import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
@@ -58,8 +62,8 @@ 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;
@@ -71,18 +75,18 @@ 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));
-        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 String.format("%-50.50s|%-30.30s|%-30.30s|%-20.20s|%-10.10s|%s", mf.getFileName(),
+    private String fileToLine(IModFile mf) {
+        return String.format(Locale.ENGLISH, "%-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(),
@@ -111,18 +115,18 @@ 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);
    }

    <T extends Event & IModBusEvent> Function<Executor, CompletableFuture<List<Throwable>>> futureVisitor(
-            final ModLoadingStage.EventGenerator<T> eventGenerator,
+            final IModStateTransition.EventGenerator<T> eventGenerator,
            final BiFunction<ModLoadingStage, Throwable, ModLoadingStage> stateChange) {
        return executor -> gather(
                this.mods.stream()
@@ -185,7 +189,7 @@ public class ModList
        return mods.stream().filter(mc -> mc.getMod() == obj).findFirst();
    }

-    public List<ModInfo> getMods()
+    public List<IModInfo> getMods()
    {
        return this.sortedList;
    }
@@ -205,24 +209,24 @@ public class ModList
        if (modFileScanData == null)
        {
            modFileScanData = this.sortedList.stream().
-                    map(ModInfo::getOwningFile).
+                    map(IModInfo::getOwningFile).
                    filter(Objects::nonNull).
-                    map(ModFileInfo::getFile).
+                    map(IModFileInfo::getFile).
                    distinct().
-                    map(ModFile::getScanResult).
+                    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) {
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -20,32 +20,25 @@
 package net.minecraftforge.fml;

 import com.google.common.collect.ImmutableList;
-import cpw.mods.modlauncher.TransformingClassLoader;
-import net.minecraftforge.api.distmarker.Dist;
-import net.minecraftforge.common.capabilities.CapabilityManager;
 import net.minecraftforge.eventbus.api.Event;
-import net.minecraftforge.fml.config.ConfigTracker;
-import net.minecraftforge.fml.config.ModConfig;
-import net.minecraftforge.fml.event.lifecycle.IModBusEvent;
+import net.minecraftforge.fml.event.IModBusEvent;
 import net.minecraftforge.fml.loading.FMLLoader;
-import net.minecraftforge.fml.loading.FMLPaths;
 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.moddiscovery.ModInfo;
 import net.minecraftforge.fml.loading.progress.StartupMessageManager;
-import net.minecraftforge.fml.network.FMLNetworkConstants;
-import net.minecraftforge.fml.network.NetworkRegistry;
 import net.minecraftforge.forgespi.language.IModInfo;
 import net.minecraftforge.forgespi.language.IModLanguageProvider;
-import net.minecraftforge.registries.GameData;
-import net.minecraftforge.registries.ObjectHolderRegistry;
-import net.minecraftforge.versions.forge.ForgeVersion;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;

-import java.util.*;
+import java.util.Arrays;
+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;
@@ -59,7 +52,7 @@ import static net.minecraftforge.fml.Logging.LOADING;
 /**
 * Loads mods.
 *
- * Dispatch cycle is seen in {@link #loadMods()} and {@link #finishMods()}
+ * Dispatch cycle is seen in {@code #loadMods()} and {@code #finishMods()}
 *
 * Overall sequence for loadMods is:
 * <dl>
@@ -67,28 +60,28 @@ import static net.minecraftforge.fml.Logging.LOADING;
 *     <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 : {@link net.minecraftforge.fml.common.Mod.EventBusSubscriber},
- *     {@link net.minecraftforge.event.RegistryEvent}, {@link net.minecraftforge.common.capabilities.CapabilityInject}
+ *     <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 {@link net.minecraftforge.fml.event.lifecycle.FMLCommonSetupEvent} to mods</dd>
+ *     <dd>Dispatches {@code net.minecraftforge.fml.event.lifecycle.FMLCommonSetupEvent} to mods</dd>
 *     <dt>SIDED_SETUP</dt>
- *     <dd>Dispatches {@link net.minecraftforge.fml.event.lifecycle.FMLClientSetupEvent} or
- *     {@link net.minecraftforge.fml.event.lifecycle.FMLDedicatedServerSetupEvent} to mods</dd>
+ *     <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 {@link net.minecraftforge.fml.event.lifecycle.InterModEnqueueEvent} to mods,
+ *     <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 {@link net.minecraftforge.fml.event.lifecycle.InterModProcessEvent} to mods,
+ *     <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 {@link net.minecraftforge.fml.event.lifecycle.FMLLoadCompleteEvent} to mods,
+ *     <dd>Dispatches {@code net.minecraftforge.fml.event.lifecycle.FMLLoadCompleteEvent} to mods,
 *     and completes the mod loading sequence.</dd>
 * </dl>
 */
@@ -96,38 +89,37 @@ public class ModLoader
 {
    private static final Logger LOGGER = LogManager.getLogger();
    private static ModLoader INSTANCE;
-    private final TransformingClassLoader launchClassLoader;
    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.launchClassLoader = FMLLoader.getLaunchClassLoader();
        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
+        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);
-        LOGGER.debug(CORE, "Loading Network data for FML net version: {}", FMLNetworkConstants.init());
-        CrashReportExtender.registerCrashCallable("ModLauncher", FMLLoader::getLauncherInfo);
-        CrashReportExtender.registerCrashCallable("ModLauncher launch target", FMLLoader::launcherHandlerName);
-        CrashReportExtender.registerCrashCallable("ModLauncher naming", FMLLoader::getNaming);
-        CrashReportExtender.registerCrashCallable("ModLauncher services", this::computeModLauncherServiceList);
-        CrashReportExtender.registerCrashCallable("FML", ForgeVersion::getSpec);
-        CrashReportExtender.registerCrashCallable("Forge", ()->ForgeVersion.getGroup()+":"+ForgeVersion.getVersion());
-        CrashReportExtender.registerCrashCallable("FML Language Providers", this::computeLanguageList);
+        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() {
@@ -159,11 +151,7 @@ public class ModLoader
        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)
-                .collect(Collectors.toList()),
+        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));
@@ -172,11 +160,11 @@ public class ModLoader
            throw new LoadingFailedException(loadingExceptions);
        }
        statusConsumer.ifPresent(c->c.accept("Building Mod List"));
-        final List<ModContainer> modContainers = loadingModList.getModFiles().stream().
-                map(ModFileInfo::getFile).
-                map(mf -> buildMods(mf, launchClassLoader)).
-                flatMap(Collection::stream).
-                collect(Collectors.toList());
+        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());
@@ -184,61 +172,45 @@ public class ModLoader
            throw new LoadingFailedException(loadingExceptions);
        }
        modList.setLoadedMods(modContainers);
-        statusConsumer.ifPresent(c->c.accept(String.format("Constructing %d mods", modList.size())));
-        dispatchAndHandleError(ModLoadingStage.CONSTRUCT, syncExecutor, parallelExecutor, periodicTask);
-        statusConsumer.ifPresent(c->c.accept("Creating registries"));
-        dispatchAndHandleError(ModLoadingStage.CREATE_REGISTRIES, syncExecutor, parallelExecutor, periodicTask);
-        ObjectHolderRegistry.findObjectHolders();
-        CapabilityManager.INSTANCE.injectCapabilities(modList.getAllScanData());
-        statusConsumer.ifPresent(c->c.accept("Adding custom tag types"));
-        GameData.setCustomTagTypesFromRegistries();
-        statusConsumer.ifPresent(c->c.accept("Populating registries"));
-        dispatchAndHandleError(ModLoadingStage.LOAD_REGISTRIES, syncExecutor, parallelExecutor, periodicTask);
-        statusConsumer.ifPresent(c->c.accept("Early mod loading complete"));
+        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 Function<Executor, CompletableFuture<Void>> beforeSidedEvent, final Function<Executor, CompletableFuture<Void>> afterSidedEvent, final Runnable periodicTask) {
-        statusConsumer.ifPresent(c->c.accept("Loading mod config"));
-        DistExecutor.unsafeRunWhenOn(Dist.CLIENT, ()->()-> ConfigTracker.INSTANCE.loadConfigs(ModConfig.Type.CLIENT, FMLPaths.CONFIGDIR.get()));
-        ConfigTracker.INSTANCE.loadConfigs(ModConfig.Type.COMMON, FMLPaths.CONFIGDIR.get());
-        statusConsumer.ifPresent(c->c.accept("Mod setup: SETUP"));
-        dispatchAndHandleError(ModLoadingStage.COMMON_SETUP, syncExecutor, parallelExecutor, periodicTask);
-        statusConsumer.ifPresent(c->c.accept("Mod setup: SIDED SETUP"));
-        dispatchAndHandleError(ModLoadingStage.SIDED_SETUP, syncExecutor, parallelExecutor, periodicTask, beforeSidedEvent, afterSidedEvent);
+    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("Mod setup: ENQUEUE IMC"));
-        dispatchAndHandleError(ModLoadingStage.ENQUEUE_IMC, syncExecutor, parallelExecutor, periodicTask);
-        statusConsumer.ifPresent(c->c.accept("Mod setup: PROCESS IMC"));
-        dispatchAndHandleError(ModLoadingStage.PROCESS_IMC, syncExecutor, parallelExecutor, periodicTask);
-        statusConsumer.ifPresent(c->c.accept("Mod setup: Final completion"));
-        dispatchAndHandleError(ModLoadingStage.COMPLETE, syncExecutor, parallelExecutor, periodicTask);
-        statusConsumer.ifPresent(c->c.accept("Freezing data"));
-        GameData.freezeData();
-        NetworkRegistry.lock();
-        statusConsumer.ifPresent(c->c.accept(String.format("Mod loading complete - %d mods loaded", ModList.get().size())));
+    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(ModLoadingStage state, ModWorkManager.DrivenExecutor syncExecutor, Executor parallelExecutor, final Runnable ticker) {
+    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;
        }
-        waitForTransition(state, syncExecutor, ticker, state.buildTransition(syncExecutor, parallelExecutor));
+        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(ModLoadingStage state, ModWorkManager.DrivenExecutor syncExecutor, Executor parallelExecutor, final Runnable ticker, Function<Executor, CompletableFuture<Void>> preSyncTask, Function<Executor, CompletableFuture<Void>> postSyncTask) {
+    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;
        }
-        waitForTransition(state, syncExecutor, ticker, state.buildTransition(syncExecutor, parallelExecutor, preSyncTask, postSyncTask));
+        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 ModLoadingStage state, final ModWorkManager.DrivenExecutor syncExecutor, final Runnable ticker, final CompletableFuture<List<Throwable>> transition) {
+    private void waitForTransition(final IModLoadingState state, final ModWorkManager.DrivenExecutor syncExecutor, final Runnable ticker, final CompletableFuture<List<Throwable>> transition) {
        while (!transition.isDone()) {
            syncExecutor.drive(ticker);
        }
@@ -259,20 +231,20 @@ public class ModLoader
                    .filter(ModLoadingException.class::isInstance)
                    .map(ModLoadingException.class::cast)
                    .collect(Collectors.toList());
-            LOGGER.fatal(LOADING,"Failed to complete lifecycle event {}, {} errors found", state, modLoadingExceptions.size());
+            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 TransformingClassLoader modClassLoader)
+    private List<ModContainer> buildMods(final ModFile modFile)
    {
        final Map<String, IModInfo> modInfoMap = modFile.getModFileInfo().getMods().stream().collect(Collectors.toMap(IModInfo::getModId, Function.identity()));

-        LOGGER.debug(LOADING, "ModContainer is {}", ModContainer.class.getClassLoader());
+        LOGGER.trace(LOADING, "ModContainer is {}", ModContainer.class.getClassLoader());
        final List<ModContainer> containers = modFile.getScanResult().getTargets()
                .entrySet()
                .stream()
-                .map(e -> buildModContainerFromTOML(modFile, modClassLoader, modInfoMap, e))
+                .map(e -> buildModContainerFromTOML(modFile, modInfoMap, e))
                .filter(Objects::nonNull)
                .collect(Collectors.toList());
        if (containers.size() != modInfoMap.size()) {
@@ -286,14 +258,14 @@ public class ModLoader
        return containers.stream().filter(mc -> mc.modLoadingStage != ModLoadingStage.ERROR).collect(Collectors.toList());
    }

-    private ModContainer buildModContainerFromTOML(final ModFile modFile, final TransformingClassLoader modClassLoader, final Map<String, IModInfo> modInfoMap, final Map.Entry<String, ? extends IModLanguageProvider.IModLanguageLoader> idToProviderEntry) {
+    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, modClassLoader, modFile.getScanResult());
+            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);
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -19,14 +19,14 @@

 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;

@@ -36,9 +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() {
@@ -50,20 +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));
    }

@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -73,7 +73,7 @@ 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
@@ -85,6 +85,6 @@ public class ModLoadingException extends RuntimeException
        return modInfo;
    }
    public String getCleanMessage() {
-        return ForgeI18n.stripControlCodes(formatToString());
+        return Bindings.getMessageParser().get().stripControlCodes(formatToString());
    }
 }
@@ -0,0 +1,9 @@
+package net.minecraftforge.fml;
+
+public enum ModLoadingPhase {
+    ERROR, // Special state for error handling
+    GATHER,
+    LOAD,
+    COMPLETE,
+    DONE;
+}
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -17,33 +17,35 @@
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

-package net.minecraftforge.server.permission.context;
+package net.minecraftforge.fml;

-import com.google.common.base.Preconditions;
-import net.minecraft.entity.player.PlayerEntity;
-import net.minecraft.world.World;
-
-import javax.annotation.Nullable;
-
-public class WorldContext extends Context
+public enum ModLoadingStage
 {
-    private final World world;
+    ERROR,
+    VALIDATE,
+    CONSTRUCT,
+    COMMON_SETUP,
+    SIDED_SETUP,
+    ENQUEUE_IMC,
+    PROCESS_IMC,
+    COMPLETE,
+    DONE;

-    public WorldContext(World w)
-    {
-        world = Preconditions.checkNotNull(w, "World can't be null in WorldContext!");
+    private final DeferredWorkQueue deferredWorkQueue;
+
+    ModLoadingStage() {
+        deferredWorkQueue = new DeferredWorkQueue(this);
    }

-    @Override
-    public World getWorld()
-    {
-        return world;
+    ModLoadingStage nextState(Throwable exception) {
+        return exception != null ? ERROR : values()[this.ordinal()+1];
    }

-    @Override
-    @Nullable
-    public PlayerEntity getPlayer()
-    {
-        return null;
+    public ModLoadingStage currentState(Throwable exception) {
+        return exception != null ? ERROR : this;
+    }
+
+    public DeferredWorkQueue getDeferredWorkQueue() {
+        return deferredWorkQueue;
    }
 }
@@ -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());
+    }
+}
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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());
    }
 }
@@ -0,0 +1,37 @@
+package net.minecraftforge.fml;
+
+import com.google.common.graph.GraphBuilder;
+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();
+    }
+}
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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();
+    }
 }
@@ -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);
+    }
+}
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -19,21 +19,24 @@

 package net.minecraftforge.fml;

-import com.google.common.io.ByteStreams;
 import com.google.gson.Gson;
 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.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;
@@ -41,8 +44,8 @@ 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 java.util.stream.Collectors;
+import java.util.zip.GZIPInputStream;

 import static net.minecraftforge.fml.VersionChecker.Status.*;

@@ -50,6 +53,7 @@ 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
    {
@@ -103,30 +107,14 @@ 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()
            {
@@ -136,39 +124,46 @@ 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);
            }
@@ -181,12 +176,11 @@ 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);

@@ -197,7 +191,7 @@ 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());
@@ -278,9 +272,8 @@ 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;
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -26,6 +26,7 @@ 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;

@@ -80,6 +81,7 @@ public class ConfigFileTypeHandler {
    }

    private boolean setupConfigFile(final ModConfig modConfig, final Path file, final ConfigFormat<?> conf) throws IOException {
+        Files.createDirectories(file.getParent());
        Path p = defaultConfigPath.resolve(modConfig.getFileName());
        if (Files.exists(p)) {
            LOGGER.info(CONFIG, "Loading default config file from path {}", p);
@@ -91,6 +93,38 @@ 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;
@@ -110,13 +144,21 @@ public class ConfigFileTypeHandler {
                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));
            }
        }
    }
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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;
+    }
 }
@@ -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;
+    }
+}
@@ -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();
+}
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * Copyright (c) 2016-2022.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
@@ -21,26 +21,26 @@ 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.event.lifecycle.IModBusEvent;
 import net.minecraftforge.fml.loading.StringUtils;

+import java.io.ByteArrayInputStream;
 import java.nio.file.Path;
+import java.util.Locale;
 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;
@@ -49,13 +49,13 @@ 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()));
    }

    private static String defaultConfigName(Type type, String modId) {
        // config file name would be "forge-client.toml" and "forge-server.toml"
-        return String.format("%s-%s.toml", modId, type.extension());
+        return String.format(Locale.ROOT, "%s-%s.toml", modId, type.extension());
    }
    public Type getType() {
        return type;
@@ -69,8 +69,9 @@ 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() {
@@ -83,10 +84,10 @@ 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);
    }

@@ -98,6 +99,11 @@ 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.
@@ -133,28 +139,4 @@ public class ModConfig
            return StringUtils.toLowerCase(name());
        }
    }
-
-    public static class ModConfigEvent extends Event implements IModBusEvent {
-        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);
-        }
-    }
 }
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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.event.lifecycle;
+package net.minecraftforge.fml.event;

 /**
 * Marker interface for events dispatched on the ModLifecycle event bus instead of the primary event bus
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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;

@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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;
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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.
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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.");
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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;

@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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);
    }
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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;

@@ -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
+}
@@ -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.fml.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;
+    }
+
+}
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -17,9 +17,8 @@
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

-package net.minecraftforge.common.asm;
+package net.minecraftforge.fml.common.asm;

-import java.nio.file.Path;
 import java.util.EnumSet;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -17,9 +17,8 @@
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

-package net.minecraftforge.common.asm;
+package net.minecraftforge.fml.common.asm;

-import java.nio.file.Path;
 import java.util.EnumSet;
 import java.util.List;
 import java.util.stream.Collectors;
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -21,16 +21,15 @@ 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;
 import org.apache.logging.log4j.Logger;

 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.util.Arrays;
-import java.util.stream.Collectors;
+import java.util.Objects;

 import static net.minecraftforge.fml.loading.LogMarkers.CORE;

@@ -50,11 +49,11 @@ 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 = CommentedFileConfig.builder(configFile).sync()
+                .onFileNotFound(FileNotFoundAction.copyData(Objects.requireNonNull(getClass().getResourceAsStream("/META-INF/defaultfmlconfig.toml"))))
+                .autosave().autoreload()
+                .writingMode(WritingMode.REPLACE)
+                .build();
        try
        {
            configData.load();
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -20,42 +20,28 @@
 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 net.minecraftforge.accesstransformer.service.AccessTransformerService;
-import net.minecraftforge.api.distmarker.Dist;
+import cpw.mods.modlauncher.util.ServiceLoaderUtils;
 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.ModFileInfo;
+import net.minecraftforge.fml.loading.moddiscovery.ModValidator;
+import net.minecraftforge.accesstransformer.service.AccessTransformerService;
+import net.minecraftforge.api.distmarker.Dist;
 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.Function;
-import java.util.function.Predicate;
 import java.util.stream.Collectors;

 import static net.minecraftforge.fml.loading.LogMarkers.CORE;
@@ -72,21 +58,16 @@ 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
    {
@@ -98,8 +79,6 @@ 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");
@@ -131,8 +110,7 @@ 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");
@@ -161,62 +139,56 @@ 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();
        production = commonLaunchHandler.isProduction();
-        progressWindowTick = EarlyProgressVisualization.INSTANCE.accept(dist, commonLaunchHandler.isData());
+
+        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 loadingModList.getModFiles().stream().map(ModFileInfo::getFile).collect(Collectors.groupingBy(ModFile::getType));
+        return List.of(modValidator.getModResources());
    }

    public static ICoreModProvider getCoreModProvider() {
@@ -232,6 +204,10 @@ 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());
@@ -243,9 +219,8 @@ 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();
    }
@@ -255,28 +230,11 @@ 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;
    }
@@ -285,10 +243,6 @@ 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");
    }
@@ -306,6 +260,14 @@ public class FMLLoader
    }

    public static boolean isSecureJarEnabled() {
-        return Launcher.INSTANCE.environment().getProperty(IEnvironment.Keys.SECURED_JARS_ENABLED.get()).orElse(false);
+        return true;
+    }
+
+    public static ModuleLayer getGameLayer() {
+        return moduleLayerManager.getLayer(IModuleLayerManager.Layer.GAME).orElseThrow();
+    }
+
+    public static VersionInfo versionInfo() {
+        return versionInfo;
    }
 }
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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()
    {
@@ -80,7 +78,7 @@ public class FMLServiceProvider implements ITransformationService
        LOGGER.debug(CORE, "Loading configuration");
        FMLConfig.load();
        LOGGER.debug(CORE, "Preparing ModFile");
-        environment.computePropertyIfAbsent(Environment.Keys.MODFILEFACTORY.get(), k->ModFile.buildFactory());
+        environment.computePropertyIfAbsent(Environment.Keys.MODFILEFACTORY.get(), k->ModFile::new);
        arguments = new HashMap<>();
        arguments.put("modLists", modListsArgumentList);
        arguments.put("mods", modsArgumentList);
@@ -97,28 +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);
    }

@@ -148,9 +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());
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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;
@@ -30,11 +32,7 @@ import org.apache.maven.artifact.versioning.ArtifactVersion;
 import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
 import org.apache.maven.artifact.versioning.VersionRange;

-import java.io.File;
-import java.net.URI;
 import java.net.URISyntaxException;
-import java.net.URL;
-import java.net.URLClassLoader;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -49,13 +47,12 @@ 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 +68,6 @@ public class LanguageLoadingProvider
    }

    private static class ModLanguageWrapper {
-
        private final IModLanguageProvider modLanguageProvider;

        private final ArtifactVersion version;
@@ -92,26 +88,14 @@ 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 +106,7 @@ 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 +131,7 @@ 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 +151,11 @@ 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 (!VersionSupportMatrix.testVersionSupportMatrix(modLoaderVersion, modLoader, "languageloader", (llid, range) -> range.containsVersion(mlw.getVersion()))) {
-            LOGGER.error("Missing language {} version {} wanted by {}, found {}", modLoader, modLoaderVersion, languageFileName, 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())));
        }

@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -22,54 +22,25 @@ package net.minecraftforge.fml.loading;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;

-import java.net.URI;
-import java.net.URISyntaxException;
-import java.net.URL;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.Paths;
-
-import static net.minecraftforge.fml.loading.LogMarkers.CORE;

 public class LibraryFinder {
    private static final Logger LOGGER = LogManager.getLogger();
    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;
    }

-    public static Path findJarPathFor(final String className, final String jarName) {
-        final URL resource = LibraryFinder.class.getClassLoader().getResource(className);
-        return findJarPathFor(className, jarName, resource);
-    }
-
-    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]));
-            } else {
-                path = Paths.get(new URI("file://"+uri.getRawSchemeSpecificPart().substring(0, uri.getRawSchemeSpecificPart().length()-resourceName.length())));
-            }
-            LOGGER.debug(CORE, "Found JAR {} at path {}", jarName, path.toString());
-            return path;
-        } catch (NullPointerException | URISyntaxException e) {
-            LOGGER.fatal(CORE, "Failed to find JAR for class {} - {}", resourceName, jarName);
-            throw new RuntimeException("Unable to locate "+resourceName+" - "+jarName, e);
-        }
-    }
-
    static Path getForgeLibraryPath(final String mcVersion, final String forgeVersion, final String forgeGroup) {
        Path forgePath = findLibsPath().resolve(MavenCoordinateResolver.get(forgeGroup, "forge", "", "universal", mcVersion+"-"+forgeVersion));
-        LOGGER.debug(CORE, "Found forge path {} is {}", forgePath, pathStatus(forgePath));
+        LOGGER.debug(LogMarkers.CORE, "Found forge path {} is {}", forgePath, pathStatus(forgePath));
        return forgePath;
    }

@@ -81,9 +52,16 @@ public class LibraryFinder {
        Path srgMcPath = findLibsPath().resolve(MavenCoordinateResolver.get("net.minecraft", type, "", "srg", mcVersion+"-"+mcpVersion));
        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));
+        LOGGER.debug(LogMarkers.CORE,"SRG MC at {} is {}", srgMcPath.toString(), pathStatus(srgMcPath));
+        LOGGER.debug(LogMarkers.CORE,"MC Extras at {} is {}", mcExtrasPath.toString(), pathStatus(mcExtrasPath));
+        LOGGER.debug(LogMarkers.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));
+    }
 }
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -41,8 +41,6 @@ public class LoadingModList
    private final List<ModFileInfo> modFiles;
    private final List<ModInfo> sortedList;
    private final Map<String, ModFileInfo> fileById;
-    @SuppressWarnings("unused")
-    private BackgroundScanHandler scanner;
    private final List<EarlyLoadingException> preLoadErrors;
    private List<ModFile> brokenFiles;

@@ -94,7 +92,6 @@ public class LoadingModList

    public void addForScanning(BackgroundScanHandler backgroundScanHandler)
    {
-        this.scanner = backgroundScanHandler;
        backgroundScanHandler.setLoadingModList(this);
        modFiles.stream()
                .map(ModFileInfo::getFile)
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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);
 }
@@ -1,23 +1,4 @@
-/*
- * Minecraft Forge
- * Copyright (c) 2016-2020.
- *
- * 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.userdev;
+package net.minecraftforge.fml.loading;

 import cpw.mods.modlauncher.api.INameMappingService;
 import org.apache.commons.lang3.tuple.Pair;
@@ -33,8 +14,6 @@ import java.util.Map;
 import java.util.function.BiConsumer;
 import java.util.function.BiFunction;

-import static net.minecraftforge.fml.loading.LogMarkers.CORE;
-
 public class MCPNamingService implements INameMappingService {
    private static final Logger LOGGER = LogManager.getLogger();
    private HashMap<String, String> methods;
@@ -47,7 +26,7 @@ public class MCPNamingService implements INameMappingService {

    @Override
    public String mappingVersion() {
-        return "1234";
+        return "1234"; //TODO: Minecraft Version?
    }

    @Override
@@ -77,7 +56,7 @@ public class MCPNamingService implements INameMappingService {
            HashMap<String,String> tmpmethods = new HashMap<>(1000);
            loadMappings("methods.csv", tmpmethods::put);
            methods = tmpmethods;
-            LOGGER.debug(CORE, "Loaded {} method mappings from methods.csv", methods.size());
+            LOGGER.debug(LogMarkers.CORE, "Loaded {} method mappings from methods.csv", methods.size());
        }
        return methods.getOrDefault(origin, origin);
    }
@@ -87,25 +66,20 @@ public class MCPNamingService implements INameMappingService {
            HashMap<String,String> tmpfields = new HashMap<>(1000);
            loadMappings("fields.csv", tmpfields::put);
            fields = tmpfields;
-            LOGGER.debug(CORE, "Loaded {} field mappings from fields.csv", fields.size());
+            LOGGER.debug(LogMarkers.CORE, "Loaded {} field mappings from fields.csv", fields.size());
        }
        return fields.getOrDefault(origin, origin);
    }

-
-    private static void loadMappings(final String mappingFileName, BiConsumer<String, String> mapStore)
-    {
-        URL path = ClassLoader.getSystemResource(mappingFileName); //We EXPLICITLY go throught the SystemClassLoader here because this is dev-time only. And will be on the root classpath.
+    private static void loadMappings(final String mappingFileName, BiConsumer<String, String> mapStore) {
+        URL path = ClassLoader.getSystemResource(mappingFileName); //We EXPLICITLY go through the SystemClassLoader here because this is dev-time only. And will be on the root classpath.
        if (path == null)
            return;

-        try (BufferedReader reader = new BufferedReader(new InputStreamReader(path.openStream())))
-        {
+        try (BufferedReader reader = new BufferedReader(new InputStreamReader(path.openStream()))) {
            reader.lines().skip(1).map(e -> e.split(",")).forEach(e -> mapStore.accept(e[0], e[1]));
-        }
-        catch (IOException e1)
-        {
-            LOGGER.error(CORE, "Error reading mappings", e1);
+        } catch (IOException e1) {
+            LOGGER.error(LogMarkers.CORE, "Error reading mappings", e1);
        }
    }
 }
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -20,6 +20,7 @@
 package net.minecraftforge.fml.loading;

 import cpw.mods.modlauncher.api.LamdbaExceptionUtils;
+import cpw.mods.modlauncher.api.NamedPath;
 import cpw.mods.modlauncher.serviceapi.ITransformerDiscoveryService;
 import org.apache.logging.log4j.LogManager;

@@ -33,36 +34,25 @@ import java.util.zip.ZipFile;

 public class ModDirTransformerDiscoverer implements ITransformerDiscoveryService {
    @Override
-    public List<Path> candidates(final Path gameDirectory) {
+    public List<NamedPath> candidates(final Path gameDirectory) {
        ModDirTransformerDiscoverer.scan(gameDirectory);
-        return ModDirTransformerDiscoverer.transformers;
+        return List.copyOf(found);
    }

-    private static List<Path> transformers = new ArrayList<>();
-    private static List<Path> locators = new ArrayList<>();
+    private final static List<NamedPath> found = new ArrayList<>();

    public static List<Path> allExcluded() {
-        ArrayList<Path> paths = new ArrayList<>();
-        paths.addAll(transformers);
-        paths.addAll(locators);
-        return paths;
-    }
-
-    public static List<Path> getExtraLocators() {
-        return locators;
+        return found.stream().map(np->np.paths()[0]).toList();
    }

    private static void scan(final Path gameDirectory) {
        final Path modsDir = gameDirectory.resolve(FMLPaths.MODSDIR.relative()).toAbsolutePath().normalize();
-        transformers = new ArrayList<>();
-        locators = new ArrayList<>();
        if (!Files.exists(modsDir)) {
            // Skip if the mods dir doesn't exist yet.
            return;
        }
-        try {
-            Files.createDirectories(modsDir);
-            Files.walk(modsDir, 1).forEach(ModDirTransformerDiscoverer::visitFile);
+        try (var walk = Files.walk(modsDir, 1)){
+            walk.forEach(ModDirTransformerDiscoverer::visitFile);
        } catch (IOException | IllegalStateException ioe) {
            LogManager.getLogger().error("Error during early discovery", ioe);
        }
@@ -74,9 +64,9 @@ public class ModDirTransformerDiscoverer implements ITransformerDiscoveryService
        if (LamdbaExceptionUtils.uncheck(() -> Files.size(path)) == 0) return;
        try (ZipFile zf = new ZipFile(new File(path.toUri()))) {
            if (zf.getEntry("META-INF/services/cpw.mods.modlauncher.api.ITransformationService") != null) {
-                transformers.add(path);
+                found.add(new NamedPath(zf.getName(), path));
            } else if (zf.getEntry("META-INF/services/net.minecraftforge.forgespi.locating.IModLocator") != null) {
-                locators.add(path);
+                found.add(new NamedPath(zf.getName(), path));
            }
        } catch (IOException ioe) {
            LogManager.getLogger().error("Zip Error when loading jar file {}", path, ioe);
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -70,13 +70,13 @@ public class ModJarURLHandler extends URLStreamHandler
        @Override
        public void connect()
        {
-            if (resource == null) {
-                modid = url.getHost();
-                // trim first char
-                modpath = url.getPath().substring(1);
-                resource = FMLLoader.getLoadingModList().getModFileById(modid).getFile().findResource(modpath);
-                manifest = FMLLoader.getLoadingModList().getModFileById(modid).getManifest();
-            }
+//            if (resource == null) {
+//                modid = url.getHost();
+//                // trim first char
+//                modpath = url.getPath().substring(1);
+//                resource = FMLLoader.getLoadingModList().getModFileById(modid).getFile().findResource(modpath);
+//                manifest = FMLLoader.getLoadingModList().getModFileById(modid).getManifest();
+//            }
        }

        @Override
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -32,7 +32,6 @@ import net.minecraftforge.fml.loading.toposort.TopologicalSort;
 import net.minecraftforge.forgespi.locating.IModFile;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.apache.logging.log4j.util.StringBuilderFormattable;
 import org.apache.maven.artifact.versioning.ArtifactVersion;
 import org.apache.maven.artifact.versioning.DefaultArtifactVersion;

@@ -42,6 +41,7 @@ import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;

+import static java.util.stream.Collectors.*;
 import static net.minecraftforge.fml.loading.LogMarkers.LOADING;

 public class ModSorter
@@ -57,22 +57,20 @@ public class ModSorter
        this.modFiles = modFiles;
    }

-    public static LoadingModList sort(List<ModFile> mods)
+    public static LoadingModList sort(List<ModFile> mods, final List<ExceptionData> errors)
    {
        final ModSorter ms = new ModSorter(mods);
        try {
            ms.buildUniqueList();
        } catch (EarlyLoadingException e) {
            // We cannot build any list with duped mods. We have to abort immediately and report it
-            return LoadingModList.of(ms.forgeAndMC, ms.forgeAndMC.stream().map(mf->(ModInfo)mf.getModInfos().get(0)).collect(Collectors.toList()), e);
+            return LoadingModList.of(ms.forgeAndMC, ms.forgeAndMC.stream().map(mf->(ModInfo)mf.getModInfos().get(0)).collect(toList()), e);
        }
-        // try and locate languages and validate dependencies
-        List<EarlyLoadingException.ExceptionData> missingLangs = ms.findLanguages();
-        List<EarlyLoadingException.ExceptionData> missingDeps = ms.verifyDependencyVersions();
-        final List<ExceptionData> failedList = Stream.concat(missingLangs.stream(), missingDeps.stream()).collect(Collectors.toList());
+        // try and validate dependencies
+        final List<ExceptionData> failedList = Stream.concat(ms.verifyDependencyVersions().stream(), errors.stream()).toList();
        // if we miss one or the other, we abort now
        if (!failedList.isEmpty()) {
-            return LoadingModList.of(ms.forgeAndMC, ms.forgeAndMC.stream().map(mf->(ModInfo)mf.getModInfos().get(0)).collect(Collectors.toList()), new EarlyLoadingException("failure to validate mod list", null, failedList));
+            return LoadingModList.of(ms.forgeAndMC, ms.forgeAndMC.stream().map(mf->(ModInfo)mf.getModInfos().get(0)).collect(toList()), new EarlyLoadingException("failure to validate mod list", null, failedList));
        } else {
            // Otherwise, lets try and sort the modlist and proceed
            EarlyLoadingException earlyLoadingException = null;
@@ -85,35 +83,22 @@ public class ModSorter
        }
    }

-    private List<EarlyLoadingException.ExceptionData> findLanguages() {
-        List<EarlyLoadingException.ExceptionData> errorData = new ArrayList<>();
-        modFiles.forEach(modFile -> {
-            try {
-                modFile.identifyLanguage();
-            } catch (EarlyLoadingException e) {
-                errorData.addAll(e.getAllData());
-            }
-        });
-        return errorData;
-    }
-
    @SuppressWarnings("UnstableApiUsage")
    private void sort()
    {
        // lambdas are identity based, so sorting them is impossible unless you hold reference to them
        final MutableGraph<ModFileInfo> graph = GraphBuilder.directed().build();
        AtomicInteger counter = new AtomicInteger();
-        Map<IModFileInfo, Integer> infos = modFiles
-                .stream()
+        Map<IModFileInfo, Integer> infos = modFiles.stream()
                .map(ModFile::getModFileInfo)
-                .collect(Collectors.toMap(Function.identity(), e -> counter.incrementAndGet()));
+                .filter(ModFileInfo.class::isInstance)
+                .collect(toMap(Function.identity(), e -> counter.incrementAndGet()));
        infos.keySet().forEach(i -> graph.addNode((ModFileInfo) i));
-        modFiles
-                .stream()
+        modFiles.stream()
                .map(ModFile::getModInfos)
-                .flatMap(Collection::stream)
+                .<IModInfo>mapMulti(Iterable::forEach)
                .map(IModInfo::getDependencies)
-                .flatMap(Collection::stream)
+                .<IModInfo.ModVersion>mapMulti(Iterable::forEach)
                .forEach(dep -> addDependency(graph, dep));

        final List<ModFileInfo> sorted;
@@ -124,33 +109,27 @@ public class ModSorter
        catch (CyclePresentException e)
        {
            Set<Set<ModFileInfo>> cycles = e.getCycles();
-            LOGGER.error(LOADING, () -> ((StringBuilderFormattable) (buffer -> {
-                buffer.append("Mod Sorting failed.\n");
-                buffer.append("Detected Cycles: ");
-                buffer.append(cycles);
-                buffer.append('\n');
-            })));
-            List<ExceptionData> dataList = cycles.stream()
-                    .map(Set::stream)
-                    .map(stream -> stream
-                            .flatMap(modFileInfo -> modFileInfo.getMods()
-                                    .stream()
-                                    .map(IModInfo::getModId))
-                            .collect(Collectors.toList()))
+            LOGGER.error(LOADING, () -> new AdvancedLogMessageAdapter(buffer ->
+                    buffer.append("Mod Sorting failed.\n")
+                    .append("Detected Cycles: ")
+                    .append(cycles)
+                    .append('\n')));
+            var dataList = cycles.stream()
+                    .<ModFileInfo>mapMulti(Iterable::forEach)
+                    .<IModInfo>mapMulti((mf,c)->mf.getMods().forEach(c))
+                    .map(IModInfo::getModId)
                    .map(list -> new ExceptionData("fml.modloading.cycle", list))
-                    .collect(Collectors.toList());
+                    .toList();
            throw new EarlyLoadingException("Sorting error", e, dataList);
        }
-        this.sortedList = sorted
-                .stream()
+        this.sortedList = sorted.stream()
                .map(ModFileInfo::getMods)
-                .flatMap(Collection::stream)
+                .<IModInfo>mapMulti(Iterable::forEach)
                .map(ModInfo.class::cast)
-                .collect(Collectors.toList());
-        this.modFiles = sorted
-                .stream()
+                .collect(toList());
+        this.modFiles = sorted.stream()
                .map(ModFileInfo::getFile)
-                .collect(Collectors.toList());
+                .collect(toList());
    }

    @SuppressWarnings("UnstableApiUsage")
@@ -164,63 +143,59 @@ public class ModSorter
        if (self == target)
            return; // in case a jar has two mods that have dependencies between
        switch (dep.getOrdering()) {
-            case BEFORE:
-                topoGraph.putEdge(self, target);
-                break;
-            case AFTER:
-                topoGraph.putEdge(target, self);
-                break;
-            case NONE:
-                break;
+            case BEFORE -> topoGraph.putEdge(self, target);
+            case AFTER -> topoGraph.putEdge(target, self);
        }
    }

    private void buildUniqueList()
    {
-        // Collect mod files by first modid in the file. This will be used for deduping purposes
-        final Map<String, List<IModFile>> modFilesByFirstId = modFiles
-                .stream()
-                .collect(Collectors.groupingBy(mf -> mf.getModInfos().get(0).getModId()));
+        // Collect mod files by module name. This will be used for deduping purposes
+        final Map<String, List<IModFile>> modFilesByFirstId = modFiles.stream()
+                .collect(groupingBy(mf -> mf.getModFileInfo().moduleName()));

        // Capture forge and MC here, so we can keep them for later
        forgeAndMC = new ArrayList<>();
-        forgeAndMC.add((ModFile)modFilesByFirstId.get("minecraft").get(0));
-        forgeAndMC.add((ModFile)modFilesByFirstId.get("forge").get(0));
+        var mc = modFilesByFirstId.get("minecraft");
+        if (mc != null && !mc.isEmpty())
+            forgeAndMC.add((ModFile) mc.get(0));
+        else
+            throw new IllegalStateException("Failed to find minecraft somehow?");
+        // TODO: remove this hardcoding and make it more flexible
+        var forge = modFilesByFirstId.get("forge");
+        if (forge != null && !forge.isEmpty())
+            forgeAndMC.add((ModFile) forge.get(0)); // Silently ignore if Forge isn't present

        // Select the newest by artifact version sorting of non-unique files thus identified
        this.modFiles = modFilesByFirstId.entrySet().stream()
                .map(this::selectNewestModInfo)
                .map(Map.Entry::getValue)
                .map(ModFile.class::cast)
-                .collect(Collectors.toList());
+                .collect(toList());

        // Transform to the full mod id list
        final Map<String, List<ModInfo>> modIds = modFiles.stream()
                .map(ModFile::getModInfos)
                .flatMap(Collection::stream)
                .map(ModInfo.class::cast)
-                .collect(Collectors.groupingBy(IModInfo::getModId));
+                .collect(groupingBy(IModInfo::getModId));

        // Its theoretically possible that some mod has somehow moved an id to a secondary place, thus causing a dupe.
        // We can't handle this
-        final List<Map.Entry<String, List<ModInfo>>> dupedMods = modIds
-                .entrySet()
-                .stream()
-                .filter(e -> e.getValue().size() > 1)
-                .collect(Collectors.toList());
+        final List<ModInfo> dupedMods = modIds.values().stream()
+                .filter(modInfos -> modInfos.size() > 1)
+                .map(modInfos -> modInfos.get(0))
+                .toList();

        if (!dupedMods.isEmpty()) {
-            final List<EarlyLoadingException.ExceptionData> duplicateModErrors = dupedMods
-                    .stream()
-                    .map(dm -> new EarlyLoadingException.ExceptionData("fml.modloading.dupedmod", dm.getValue().get(0), Objects.toString(dm.getValue().get(0))))
-                    .collect(Collectors.toList());
+            final List<EarlyLoadingException.ExceptionData> duplicateModErrors = dupedMods.stream()
+                    .map(dm -> new EarlyLoadingException.ExceptionData("fml.modloading.dupedmod",
+                            dm, Objects.toString(dm))).toList();
            throw new EarlyLoadingException("Duplicate mods found", null,  duplicateModErrors);
        }

-        modIdNameLookup = modIds
-                .entrySet()
-                .stream()
-                .collect(Collectors.toMap(Map.Entry::getKey, e -> e.getValue().get(0)));
+        modIdNameLookup = modIds.entrySet().stream()
+                .collect(toMap(Map.Entry::getKey, e -> e.getValue().get(0)));
    }

    private Map.Entry<String, IModFile> selectNewestModInfo(Map.Entry<String, List<IModFile>> fullList) {
@@ -230,44 +205,47 @@ public class ModSorter
            modInfoList.sort(Comparator.<IModFile, ArtifactVersion>comparing(mf -> mf.getModInfos().get(0).getVersion()).reversed());
            LOGGER.debug("Selected file {} for modid {} with version {}", modInfoList.get(0).getFileName(), fullList.getKey(), modInfoList.get(0).getModInfos().get(0).getVersion());
        }
-        return new AbstractMap.SimpleImmutableEntry<>(fullList.getKey(), modInfoList.get(0));
+        return Map.entry(fullList.getKey(), modInfoList.get(0));
    }

    private List<EarlyLoadingException.ExceptionData> verifyDependencyVersions()
    {
-        final Map<String, ArtifactVersion> modVersions = modFiles
-                .stream()
+        final var modVersions = modFiles.stream()
                .map(ModFile::getModInfos)
-                .flatMap(Collection::stream)
-                .collect(Collectors.toMap(IModInfo::getModId, IModInfo::getVersion));
+                .<IModInfo>mapMulti(Iterable::forEach)
+                .collect(toMap(IModInfo::getModId, IModInfo::getVersion));

-        final Map<IModInfo, List<IModInfo.ModVersion>> modVersionDependencies = modFiles
-                .stream()
+        final var modVersionDependencies = modFiles.stream()
                .map(ModFile::getModInfos)
-                .flatMap(Collection::stream)
-                .collect(Collectors.groupingBy(Function.identity(), Java9BackportUtils.flatMapping(e -> e.getDependencies().stream(), Collectors.toList())));
+                .<IModInfo>mapMulti(Iterable::forEach)
+                .collect(groupingBy(Function.identity(), flatMapping(e -> e.getDependencies().stream(), toList())));

-        final Set<IModInfo.ModVersion> mandatoryModVersions = modVersionDependencies
-                .values()
-                .stream()
-                .flatMap(Collection::stream)
-                .filter(mv -> mv.isMandatory() && mv.getSide().isCorrectSide())
-                .collect(Collectors.toSet());
+        final var modRequirements = modVersionDependencies.values().stream()
+                .<IModInfo.ModVersion>mapMulti(Iterable::forEach)
+                .filter(mv -> mv.getSide().isCorrectSide())
+                .collect(toSet());

-        LOGGER.debug(LOADING, "Found {} mandatory requirements", mandatoryModVersions.size());
-        final Set<IModInfo.ModVersion> missingVersions = mandatoryModVersions
-                .stream()
-                .filter(mv->this.modVersionNotContained(mv, modVersions))
-                .collect(Collectors.toSet());
-        LOGGER.debug(LOADING, "Found {} mandatory mod requirements missing", missingVersions.size());
+        final long mandatoryRequired = modRequirements.stream().filter(IModInfo.ModVersion::isMandatory).count();
+        LOGGER.debug(LOADING, "Found {} mod requirements ({} mandatory, {} optional)", modRequirements.size(), mandatoryRequired, modRequirements.size() - mandatoryRequired);
+        final var missingVersions = modRequirements.stream()
+                .filter(mv -> (mv.isMandatory() || modVersions.containsKey(mv.getModId())) && this.modVersionNotContained(mv, modVersions))
+                .collect(toSet());
+        final long mandatoryMissing = missingVersions.stream().filter(IModInfo.ModVersion::isMandatory).count();
+        LOGGER.debug(LOADING, "Found {} mod requirements missing ({} mandatory, {} optional)", missingVersions.size(), mandatoryMissing, missingVersions.size() - mandatoryMissing);

        if (!missingVersions.isEmpty()) {
-            return missingVersions
-                    .stream()
-                    .map(mv -> new ExceptionData("fml.modloading.missingdependency", mv.getOwner(),
-                            mv.getModId(), mv.getOwner().getModId(), mv.getVersionRange(),
+            if (mandatoryMissing > 0) {
+                LOGGER.error(LOADING, "Missing mandatory dependencies: {}", missingVersions.stream().filter(IModInfo.ModVersion::isMandatory).map(IModInfo.ModVersion::getModId).collect(Collectors.joining(", ")));
+            }
+            if (missingVersions.size() - mandatoryMissing > 0) {
+                LOGGER.error(LOADING, "Unsupported installed optional dependencies: {}", missingVersions.stream().filter(ver -> !ver.isMandatory()).map(IModInfo.ModVersion::getModId).collect(Collectors.joining(", ")));
+            }
+
+            return missingVersions.stream()
+                    .map(mv -> new ExceptionData(mv.isMandatory() ? "fml.modloading.missingdependency" : "fml.modloading.missingdependency.optional",
+                            mv.getOwner(), mv.getModId(), mv.getOwner().getModId(), mv.getVersionRange(),
                            modVersions.getOrDefault(mv.getModId(), new DefaultArtifactVersion("null"))))
-                    .collect(Collectors.toList());
+                    .toList();
        }
        return Collections.emptyList();
    }
@@ -275,6 +253,6 @@ public class ModSorter
    private boolean modVersionNotContained(final IModInfo.ModVersion mv, final Map<String, ArtifactVersion> modVersions)
    {
        return !(VersionSupportMatrix.testVersionSupportMatrix(mv.getVersionRange(), mv.getModId(), "mod", (modId, range) -> modVersions.containsKey(modId) &&
-                (range.containsVersion(modVersions.get(modId)) || modVersions.get(modId).toString().equals("NONE"))));
+                (range.containsVersion(modVersions.get(modId)) || modVersions.get(modId).toString().equals("0.0NONE"))));
    }
 }
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -196,7 +196,7 @@ public class RuntimeDistCleaner implements ILaunchPluginService
        private final List<Handle> dynamicLambdaHandles = new ArrayList<>();

        public LambdaGatherer() {
-            super(Opcodes.ASM7);
+            super(Opcodes.ASM9);
        }

        public void accept(MethodNode method) {
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -30,8 +30,8 @@ import java.util.Map;
 public class StringSubstitutor
 {
    private static final Map<String,String> globals = ImmutableMap.of(
-            "mcVersion", FMLLoader.mcVersion,
-            "forgeVersion", FMLLoader.forgeVersion
+            "mcVersion", FMLLoader.versionInfo().mcVersion(),
+            "forgeVersion", FMLLoader.versionInfo().forgeVersion()
    );

    public static String replace(final String in, final ModFile file) {
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -26,8 +26,7 @@ import java.net.URL;
 import java.util.Locale;
 import java.util.Map;

-public class StringUtils
-{
+public class StringUtils {
    public static String toLowerCase(final String str) {
        return str.toLowerCase(Locale.ROOT);
    }
@@ -42,12 +41,12 @@ public class StringUtils
    }

    public static URL toURL(final String string) {
-        try
-        {
-            return new URL(string);
-        }
-        catch (MalformedURLException e)
-        {
+        if (string == null || string.trim().isEmpty() || string.contains("myurl.me") || string.contains("example.invalid"))
+            return null;
+
+        try {
+            return new URL(string); }
+        catch (MalformedURLException e) {
            throw new RuntimeException(e);
        }
    }
@@ -1,6 +1,6 @@
 /*
 * Minecraft Forge
- * Copyright (c) 2016-2020.
+ * 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
@@ -0,0 +1,17 @@
+package net.minecraftforge.fml.loading;
+
+import java.util.Map;
+
+public record VersionInfo(String forgeVersion, String mcVersion, String mcpVersion, String forgeGroup) {
+    VersionInfo(Map<String, ?> arguments) {
+        this((String) arguments.get("forgeVersion"), (String) arguments.get("mcVersion"), (String) arguments.get("mcpVersion"), (String) arguments.get("forgeGroup"));
+    }
+
+    public String mcAndForgeVersion() {
+        return mcVersion+"-"+forgeVersion;
+    }
+
+    public String mcAndMCPVersion() {
+        return mcVersion + "-" + mcpVersion;
+    }
+}