Implement interface injection

src/main/java/net/neoforged/neoform/runtime/actions/ApplySourceTransformAction.java

@@ -41,9 +41,16 @@ public class ApplySourceTransformAction extends ExternalJavaToolAction {
 
     /**
      * Additional paths to access transformers.
+     * <p>
+     * A description of the format can be found in the <a href="https://docs.neoforged.net/docs/advanced/accesstransformers">NeoForge documentation</a>.
      */
     private List<Path> additionalAccessTransformers = new ArrayList<>();
 
+    /**
+     * Additional paths to interface injection data files.
+     */
+    private List<Path> injectedInterfaces = new ArrayList<>();
+
     /**
      * Path to a Parchment data archive.
      */
@@ -88,6 +95,16 @@ public void run(ProcessingEnvironment environment) throws IOException, Interrupt
             }
         }
 
+        if (!injectedInterfaces.isEmpty()) {
+            args.add("--enable-interface-injection");
+            for (var path : injectedInterfaces) {
+                args.add("--interface-injection-data");
+                args.add(environment.getPathArgument(path));
+            }
+            args.add("--interface-injection-stub-location");
+            args.add("{stubs}");
+        }
+
         if (parchmentData != null) {
             args.add("--enable-parchment");
             args.add("--parchment-mappings=" + environment.getPathArgument(parchmentData.toAbsolutePath()));
@@ -114,6 +131,7 @@ public void computeCacheKey(CacheKeyBuilder ck) {
         super.computeCacheKey(ck);
         ck.addStrings("access transformers data ids", accessTransformersData);
         ck.addPaths("additional access transformers", additionalAccessTransformers);
+        ck.addPaths("injected interfaces", injectedInterfaces);
         if (parchmentData != null) {
             ck.addPath("parchment data", parchmentData);
         }
@@ -137,6 +155,10 @@ public void setAdditionalAccessTransformers(List<Path> additionalAccessTransform
         this.additionalAccessTransformers = List.copyOf(additionalAccessTransformers);
     }
 
+    public void setInjectedInterfaces(List<Path> injectedInterfaces) {
+        this.injectedInterfaces = List.copyOf(injectedInterfaces);
+    }
+
     public @Nullable Path getParchmentData() {
         return parchmentData;
     }

src/main/java/net/neoforged/neoform/runtime/actions/ExtensibleClasspath.java

@@ -2,6 +2,7 @@
 
 import net.neoforged.neoform.runtime.artifacts.ClasspathItem;
 import net.neoforged.neoform.runtime.cache.CacheKeyBuilder;
+import net.neoforged.neoform.runtime.graph.NodeOutput;
 import net.neoforged.neoform.runtime.manifests.MinecraftLibrary;
 import net.neoforged.neoform.runtime.utils.MavenCoordinate;
 import org.jetbrains.annotations.Nullable;
@@ -109,6 +110,7 @@ public void computeCacheKey(String prefix, CacheKeyBuilder ck) {
                     }
                 }
                 case ClasspathItem.PathItem(Path path) -> ck.addPath(component, path);
+                case ClasspathItem.NodeOutputItem(NodeOutput output) -> ck.addPath(component, output.getResultPath());
             }
         }
     }

src/main/java/net/neoforged/neoform/runtime/artifacts/ArtifactManager.java

@@ -4,6 +4,7 @@
 import net.neoforged.neoform.runtime.cli.LockManager;
 import net.neoforged.neoform.runtime.downloads.DownloadManager;
 import net.neoforged.neoform.runtime.downloads.DownloadSpec;
+import net.neoforged.neoform.runtime.graph.NodeOutput;
 import net.neoforged.neoform.runtime.manifests.LauncherManifest;
 import net.neoforged.neoform.runtime.manifests.MinecraftLibrary;
 import net.neoforged.neoform.runtime.manifests.MinecraftVersionManifest;
@@ -138,6 +139,7 @@ public List<Path> resolveClasspath(Collection<ClasspathItem> classpathItems) thr
                 }
                 case ClasspathItem.MinecraftLibraryItem(MinecraftLibrary library) -> get(library).path();
                 case ClasspathItem.PathItem(Path path) -> path;
+                case ClasspathItem.NodeOutputItem(NodeOutput output) -> output.getResultPath();
             };
             result.add(pathToAdd);
         }

src/main/java/net/neoforged/neoform/runtime/artifacts/ClasspathItem.java

@@ -1,5 +1,6 @@
 package net.neoforged.neoform.runtime.artifacts;
 
+import net.neoforged.neoform.runtime.graph.NodeOutput;
 import net.neoforged.neoform.runtime.manifests.MinecraftLibrary;
 import net.neoforged.neoform.runtime.utils.MavenCoordinate;
 import org.jetbrains.annotations.Nullable;
@@ -27,6 +28,10 @@ static ClasspathItem of(MavenCoordinate mavenLibrary, @Nullable URI repositoryBa
         return new MavenCoordinateItem(mavenLibrary, repositoryBaseUrl);
     }
 
+    static ClasspathItem of(NodeOutput output) {
+        return new NodeOutputItem(output);
+    }
+
     record MavenCoordinateItem(MavenCoordinate coordinate, @Nullable URI repositoryBaseUrl) implements ClasspathItem {
         @Override
         public String toString() {
@@ -51,4 +56,11 @@ public String toString() {
             return library.toString();
         }
     }
+
+    record NodeOutputItem(NodeOutput output) implements ClasspathItem {
+        @Override
+        public String toString() {
+            return output.getResultPath().toString();
+        }
+    }
 }

src/main/java/net/neoforged/neoform/runtime/cli/RunNeoFormCommand.java

@@ -6,9 +6,11 @@
 import net.neoforged.neoform.runtime.actions.MergeWithSourcesAction;
 import net.neoforged.neoform.runtime.actions.PatchActionFactory;
 import net.neoforged.neoform.runtime.actions.RecompileSourcesAction;
+import net.neoforged.neoform.runtime.artifacts.ClasspathItem;
 import net.neoforged.neoform.runtime.config.neoforge.NeoForgeConfig;
 import net.neoforged.neoform.runtime.engine.NeoFormEngine;
 import net.neoforged.neoform.runtime.graph.ExecutionGraph;
+import net.neoforged.neoform.runtime.graph.ExecutionNode;
 import net.neoforged.neoform.runtime.graph.NodeOutput;
 import net.neoforged.neoform.runtime.graph.NodeOutputType;
 import net.neoforged.neoform.runtime.graph.transforms.GraphTransform;
@@ -25,6 +27,7 @@
 import java.io.StringWriter;
 import java.nio.file.Files;
 import java.nio.file.NoSuchFileException;
+import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.nio.file.StandardCopyOption;
 import java.util.ArrayList;
@@ -37,9 +40,6 @@
 public class RunNeoFormCommand extends NeoFormEngineCommand {
     private static final Logger LOG = Logger.create();
 
-    @CommandLine.ParentCommand
-    Main commonOptions;
-
     @CommandLine.ArgGroup(exclusive = false, multiplicity = "1")
     SourceArtifacts sourceArtifacts;
 
@@ -49,9 +49,12 @@ public class RunNeoFormCommand extends NeoFormEngineCommand {
     @CommandLine.Option(names = "--write-result", arity = "*")
     List<String> writeResults = new ArrayList<>();
 
-    @CommandLine.Option(names = "--access-transformer", arity = "*")
+    @CommandLine.Option(names = "--access-transformer", arity = "*", description = "path to an access transformer file, which widens the access modifiers of classes/methods/fields")
     List<String> additionalAccessTransformers = new ArrayList<>();
 
+    @CommandLine.Option(names = "--interface-injection-data", arity = "*", description = "path to an interface injection data file, which extends classes with implements/extends clauses")
+    List<Path> interfaceInjectionDataFiles = new ArrayList<>();
+
     @CommandLine.Option(names = "--validate-access-transformers", description = "Whether access transformers should be validated and fatal errors should arise if they target members that do not exist")
     boolean validateAccessTransformers;
 
@@ -99,7 +102,8 @@ protected void runWithNeoFormEngine(NeoFormEngine engine, List<AutoCloseable> cl
             engine.addManagedResource(neoforgeSourcesZip);
             engine.addManagedResource(neoforgeClassesZip);
 
-            var transformSources = getOrAddTransformSourcesNode(engine);
+            var transformSources = getOrAddTransformSourcesAction(engine);
+
             transformSources.setAccessTransformersData(List.of("neoForgeAccessTransformers"));
 
             // Add NeoForge libraries to the list of libraries
@@ -133,15 +137,15 @@ protected void runWithNeoFormEngine(NeoFormEngine engine, List<AutoCloseable> cl
         }
 
         if (!additionalAccessTransformers.isEmpty()) {
-            var transformSources = getOrAddTransformSourcesNode(engine);
+            var transformSources = getOrAddTransformSourcesAction(engine);
             transformSources.setAdditionalAccessTransformers(additionalAccessTransformers.stream().map(Paths::get).toList());
             if (validateAccessTransformers) {
                 transformSources.addArg("--access-transformer-validation=error");
             }
         }
 
         if (parchmentData != null) {
-            var transformSources = getOrAddTransformSourcesNode(engine);
+            var transformSources = getOrAddTransformSourcesAction(engine);
             var parchmentDataFile = artifactManager.get(parchmentData);
             transformSources.setParchmentData(parchmentDataFile.path());
 
@@ -150,6 +154,20 @@ protected void runWithNeoFormEngine(NeoFormEngine engine, List<AutoCloseable> cl
             }
         }
 
+        if (!interfaceInjectionDataFiles.isEmpty()) {
+            var transformNode = getOrAddTransformSourcesNode(engine);
+            ((ApplySourceTransformAction) transformNode.action()).setInjectedInterfaces(interfaceInjectionDataFiles);
+
+            // Add the stub source jar to the recomp classpath
+            engine.applyTransform(new ModifyAction<>(
+                    "recompile",
+                    RecompileSourcesAction.class,
+                    action -> {
+                        action.getClasspath().add(ClasspathItem.of(transformNode.getRequiredOutput("stubs")));
+                    }
+            ));
+        }
+
         execute(engine);
     }
 
@@ -197,7 +215,7 @@ private void execute(NeoFormEngine engine) throws InterruptedException, IOExcept
             LOG.println(stringWriter.toString());
         }
 
-        var neededResults = writeResults.stream().map(encodedResult -> {
+        var neededResults = writeResults.stream().<String[]>map(encodedResult -> {
                     var parts = encodedResult.split(":", 2);
                     if (parts.length != 2) {
                         throw new IllegalArgumentException("Specify a result destination in the form: <resultid>:<destination>");
@@ -235,12 +253,16 @@ private void execute(NeoFormEngine engine) throws InterruptedException, IOExcept
         }
     }
 
-    private static ApplySourceTransformAction getOrAddTransformSourcesNode(NeoFormEngine engine) {
+    private static ApplySourceTransformAction getOrAddTransformSourcesAction(NeoFormEngine engine) {
+        return (ApplySourceTransformAction) getOrAddTransformSourcesNode(engine).action();
+    }
+
+    private static ExecutionNode getOrAddTransformSourcesNode(NeoFormEngine engine) {
         var graph = engine.getGraph();
         var transformNode = graph.getNode("transformSources");
         if (transformNode != null) {
-            if (transformNode.action() instanceof ApplySourceTransformAction action) {
-                return action;
+            if (transformNode.action() instanceof ApplySourceTransformAction) {
+                return transformNode;
             } else {
                 throw new IllegalStateException("Node transformSources has a different action type than expected. Expected: "
                                                 + ApplySourceTransformAction.class + " but got " + transformNode.action().getClass());
@@ -256,7 +278,8 @@ private static ApplySourceTransformAction getOrAddTransformSourcesNode(NeoFormEn
                     builder.inputFromNodeOutput("libraries", "listLibraries", "output");
                     var action = new ApplySourceTransformAction();
                     builder.action(action);
-                    return builder.output("output", NodeOutputType.ZIP, "Sources with additional transforms (ATs, Parchment) applied");
+                    builder.output("stubs", NodeOutputType.JAR, "Additional stubs (resulted as part of interface injection) to add to the recompilation classpath");
+                    return builder.output("output", NodeOutputType.ZIP, "Sources with additional transforms (ATs, Parchment, Interface Injections) applied");
                 }
         ).apply(engine, graph);
 

src/main/java/net/neoforged/neoform/runtime/engine/NeoFormEngine.java

@@ -497,6 +497,10 @@ public void applyTransforms(List<GraphTransform> transforms) {
         }
     }
 
+    public void applyTransform(GraphTransform transform) {
+        transform.apply(this, graph);
+    }
+
     public ExecutionGraph getGraph() {
         return graph;
     }

src/main/resources/tools.properties

@@ -1,5 +1,5 @@
 
 # https://projects.neoforged.net/neoforged/javasourcetransformer
-JAVA_SOURCE_TRANSFORMER=net.neoforged.jst:jst-cli-bundle:1.0.50
+JAVA_SOURCE_TRANSFORMER=net.neoforged.jst:jst-cli-bundle:1.0.58
 
 DIFF_PATCH=codechicken:DiffPatch:1.5.0.29:all