Add task to generate finalizeSpawn MethodRedirector coremod targets

.github/workflows/check-local-changes.yml

@@ -41,7 +41,7 @@ jobs:
         run: ./gradlew generatePackageInfos
 
       - name: Gen patches and ATs
-        run: ./gradlew :neoforge:genPatches :neoforge:generateAccessTransformers
+        run: ./gradlew :neoforge:genPatches :neoforge:generateAccessTransformers :neoforge:generateFinalizeSpawnTargets
 
       - name: Run datagen with Gradle
         run: ./gradlew :neoforge:runData :tests:runData

buildSrc/src/main/java/net/neoforged/neodev/GenerateFinalizeSpawnTargets.java

@@ -0,0 +1,81 @@
+package net.neoforged.neodev;
+
+import com.google.gson.GsonBuilder;
+import net.neoforged.neodev.utils.AsmUtils;
+import net.neoforged.neodev.utils.FileUtils;
+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.ClassVisitor;
+import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+import java.util.Set;
+import java.util.TreeSet;
+
+/**
+ * This task is used to generate targets for the finalizeSpawn MethodRedirector coremod.
+ */
+public abstract class GenerateFinalizeSpawnTargets extends DefaultTask {
+    @InputFile
+    public abstract RegularFileProperty getInput();
+
+    @OutputFile
+    public abstract RegularFileProperty getOutput();
+
+    @TaskAction
+    public void exec() throws IOException {
+        var visitor = new Visitor();
+        AsmUtils.visitAllClasses(
+                getInput().getAsFile().get(),
+                visitor,
+                ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES);
+
+        var classList = List.copyOf(visitor.matchedClasses);
+
+        FileUtils.writeStringSafe(
+                getOutput().getAsFile().get().toPath(),
+                new GsonBuilder().setPrettyPrinting().disableHtmlEscaping().create().toJson(classList),
+                StandardCharsets.UTF_8);
+    }
+
+    static class Visitor extends ClassVisitor {
+        final Set<String> matchedClasses = new TreeSet<>();
+        String currentClass = null;
+
+        protected Visitor() {
+            super(Opcodes.ASM9);
+        }
+
+        @Override
+        public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
+            currentClass = name;
+        }
+
+        @Override
+        public MethodVisitor visitMethod(int access, String name, String descriptor, String signature, String[] exceptions) {
+            // Ignore these classes as we special case them
+            if (currentClass.equals("net/minecraft/world/level/BaseSpawner")
+                    || currentClass.equals("net/minecraft/world/level/block/entity/trialspawner/TrialSpawner")) {
+                return null;
+            }
+
+            return new MethodVisitor(api) {
+                @Override
+                public void visitMethodInsn(int opcode, String owner, String name, String descriptor, boolean isInterface) {
+                    if (opcode == Opcodes.INVOKEVIRTUAL
+                            && name.equals("finalizeSpawn")
+                            && descriptor.equals("(Lnet/minecraft/world/level/ServerLevelAccessor;Lnet/minecraft/world/DifficultyInstance;Lnet/minecraft/world/entity/EntitySpawnReason;Lnet/minecraft/world/entity/SpawnGroupData;)Lnet/minecraft/world/entity/SpawnGroupData;")) {
+                        matchedClasses.add(currentClass);
+                    }
+                }
+            };
+        }
+    }
+}

buildSrc/src/main/java/net/neoforged/neodev/utils/AsmUtils.java

@@ -0,0 +1,27 @@
+package net.neoforged.neodev.utils;
+
+import org.objectweb.asm.ClassReader;
+import org.objectweb.asm.ClassVisitor;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.zip.ZipFile;
+
+public final class AsmUtils {
+    private AsmUtils() {}
+
+    public static void visitAllClasses(File jarFile, ClassVisitor visitor, int parsingOptions) throws IOException {
+        try (var zip = new ZipFile(jarFile)) {
+            var entries = zip.entries();
+            while (entries.hasMoreElements()) {
+                var next = entries.nextElement();
+                if (next.isDirectory() || !next.getName().endsWith(".class")) continue;
+
+                try (var in = zip.getInputStream(next)) {
+                    var reader = new ClassReader(in);
+                    reader.accept(visitor, parsingOptions);
+                }
+            }
+        }
+    }
+}

buildSrc/src/main/java/net/neoforged/neodev/utils/structure/ClassStructureVisitor.java

@@ -1,5 +1,6 @@
 package net.neoforged.neodev.utils.structure;
 
+import net.neoforged.neodev.utils.AsmUtils;
 import org.apache.commons.lang3.mutable.MutableInt;
 import org.objectweb.asm.ClassReader;
 import org.objectweb.asm.ClassVisitor;
@@ -13,7 +14,6 @@
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.zip.ZipFile;
 
 public final class ClassStructureVisitor extends ClassVisitor {
     private final Map<String, ClassInfo> classes;
@@ -26,19 +26,10 @@ private ClassStructureVisitor(Map<String, ClassInfo> classes) {
 
     public static Map<String, ClassInfo> readJar(File file) throws IOException {
         var map = new HashMap<String, ClassInfo>();
-        var visitor = new ClassStructureVisitor(map);
-        try (var zip = new ZipFile(file)) {
-            var entries = zip.entries();
-            while (entries.hasMoreElements()) {
-                var next = entries.nextElement();
-                if (next.isDirectory() || !next.getName().endsWith(".class")) continue;
-
-                try (var in = zip.getInputStream(next)) {
-                    var reader = new ClassReader(in);
-                    reader.accept(visitor, ClassReader.SKIP_CODE | ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES);
-                }
-            }
-        }
+        AsmUtils.visitAllClasses(
+                file,
+                new ClassStructureVisitor(map),
+                ClassReader.SKIP_CODE | ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES);
         return map;
     }
 

coremods/src/main/resources/net/neoforged/neoforge/coremods/finalize_spawn_targets.json

@@ -1,24 +1,24 @@
 [
-    "net/minecraft/server/commands/RaidCommand",
-    "net/minecraft/server/commands/SummonCommand",
-    "net/minecraft/world/entity/EntityType",
-    "net/minecraft/world/entity/ai/village/VillageSiege",
-    "net/minecraft/world/entity/animal/frog/Tadpole",
-    "net/minecraft/world/entity/animal/horse/SkeletonTrapGoal",
-    "net/minecraft/world/entity/monster/Evoker$EvokerSummonSpellGoal",
-    "net/minecraft/world/entity/monster/Spider",
-    "net/minecraft/world/entity/monster/Strider",
-    "net/minecraft/world/entity/monster/Zombie",
-    "net/minecraft/world/entity/monster/ZombieVillager",
-    "net/minecraft/world/entity/npc/CatSpawner",
-    "net/minecraft/world/entity/npc/Villager",
-    "net/minecraft/world/entity/raid/Raid",
-    "net/minecraft/world/level/NaturalSpawner",
-    "net/minecraft/world/level/levelgen/PatrolSpawner",
-    "net/minecraft/world/level/levelgen/PhantomSpawner",
-    "net/minecraft/world/level/levelgen/structure/structures/OceanMonumentPieces$OceanMonumentPiece",
-    "net/minecraft/world/level/levelgen/structure/structures/OceanRuinPieces$OceanRuinPiece",
-    "net/minecraft/world/level/levelgen/structure/structures/SwampHutPiece",
-    "net/minecraft/world/level/levelgen/structure/structures/WoodlandMansionPieces$WoodlandMansionPiece",
-    "net/minecraft/world/level/levelgen/structure/templatesystem/StructureTemplate"
+  "net/minecraft/server/commands/RaidCommand",
+  "net/minecraft/server/commands/SummonCommand",
+  "net/minecraft/world/entity/EntityType",
+  "net/minecraft/world/entity/ai/village/VillageSiege",
+  "net/minecraft/world/entity/animal/frog/Tadpole",
+  "net/minecraft/world/entity/animal/horse/SkeletonTrapGoal",
+  "net/minecraft/world/entity/monster/Evoker$EvokerSummonSpellGoal",
+  "net/minecraft/world/entity/monster/Spider",
+  "net/minecraft/world/entity/monster/Strider",
+  "net/minecraft/world/entity/monster/Zombie",
+  "net/minecraft/world/entity/monster/ZombieVillager",
+  "net/minecraft/world/entity/npc/CatSpawner",
+  "net/minecraft/world/entity/npc/Villager",
+  "net/minecraft/world/entity/raid/Raid",
+  "net/minecraft/world/level/NaturalSpawner",
+  "net/minecraft/world/level/levelgen/PatrolSpawner",
+  "net/minecraft/world/level/levelgen/PhantomSpawner",
+  "net/minecraft/world/level/levelgen/structure/structures/OceanMonumentPieces$OceanMonumentPiece",
+  "net/minecraft/world/level/levelgen/structure/structures/OceanRuinPieces$OceanRuinPiece",
+  "net/minecraft/world/level/levelgen/structure/structures/SwampHutPiece",
+  "net/minecraft/world/level/levelgen/structure/structures/WoodlandMansionPieces$WoodlandMansionPiece",
+  "net/minecraft/world/level/levelgen/structure/templatesystem/StructureTemplate"
 ]

projects/neoforge/build.gradle

@@ -1,6 +1,7 @@
 import net.neoforged.jarcompatibilitychecker.gradle.JCCPlugin
 import net.neoforged.jarcompatibilitychecker.gradle.CompatibilityTask
 import net.neoforged.jarcompatibilitychecker.gradle.ProvideNeoForgeJarTask
+import net.neoforged.neodev.GenerateFinalizeSpawnTargets
 
 plugins {
     id 'java-library'
@@ -222,6 +223,13 @@ generateAccessTransformers {
     )
 }
 
+tasks.register("generateFinalizeSpawnTargets", GenerateFinalizeSpawnTargets.class) {
+    group generateAccessTransformers.group
+    description "Generate the targets for the finalizeSpawn MethodRedirector coremod"
+    input = generateAccessTransformers.input
+    output = rootProject.file("coremods/src/main/resources/net/neoforged/neoforge/coremods/finalize_spawn_targets.json")
+}
+
 tasks.withType(JavaCompile.class).configureEach {
     // Increase memory used during compilation, to avoid OutOfMemoryErrors
     options.forkOptions.memoryMaximumSize = '2g'