Add support for locating mod sources with services from the classpath. (

#93)

Co-authored-by: Technici4n <[email protected]>

loader/src/main/java/net/neoforged/fml/loading/ClasspathTransformerDiscoverer.java

@@ -7,6 +7,7 @@
 
 import cpw.mods.modlauncher.api.NamedPath;
 import cpw.mods.modlauncher.serviceapi.ITransformerDiscoveryService;
+import net.neoforged.fml.loading.targets.CommonLaunchHandler;
 import org.apache.logging.log4j.LogManager;
 
 import java.io.File;
@@ -16,6 +17,8 @@
 import java.nio.file.Path;
 import java.util.*;
 
+import static net.neoforged.fml.loading.TransformerDiscovererConstants.shouldLoadInServiceLayer;
+
 public class ClasspathTransformerDiscoverer implements ITransformerDiscoveryService {
 
     private final List<Path> legacyClasspath = Arrays.stream(System.getProperty("legacyClassPath", "").split(File.pathSeparator)).map(Path::of).toList();
@@ -44,6 +47,8 @@ private void scan(final Path gameDirectory) {
             for (final String serviceClass : TransformerDiscovererConstants.SERVICES) {
                 locateTransformers("META-INF/services/" + serviceClass);
             }
+
+            scanModClasses();
         } catch (IOException e) {
             LogManager.getLogger().error("Error during discovery of transform services from the classpath", e);
         }
@@ -59,4 +64,14 @@ private void locateTransformers(String resource) throws IOException {
             found.add(new NamedPath(path.toUri().toString(), path));
         }
     }
+
+    private void scanModClasses() {
+        final Map<String, List<Path>> modClassPaths = CommonLaunchHandler.getModClasses();
+        modClassPaths.forEach((modid, paths) -> {
+            if (shouldLoadInServiceLayer(paths.toArray(Path[]::new))) {
+                found.add(new NamedPath(modid, paths.toArray(Path[]::new)));
+            }
+        });
+    }
+
 }

loader/src/main/java/net/neoforged/fml/loading/ModDirTransformerDiscoverer.java

@@ -6,9 +6,6 @@
 package net.neoforged.fml.loading;
 
 import com.mojang.logging.LogUtils;
-import cpw.mods.jarhandling.JarContentsBuilder;
-import cpw.mods.jarhandling.JarMetadata;
-import cpw.mods.jarhandling.SecureJar;
 import cpw.mods.modlauncher.api.LamdbaExceptionUtils;
 import cpw.mods.modlauncher.api.NamedPath;
 import cpw.mods.modlauncher.serviceapi.ITransformerDiscoveryService;
@@ -93,9 +90,6 @@ private static boolean shouldLoadInServiceLayer(Path path) {
         if (!path.toString().endsWith(".jar")) return false;
         if (LamdbaExceptionUtils.uncheck(() -> Files.size(path)) == 0) return false;
 
-        JarMetadata metadata = JarMetadata.from(new JarContentsBuilder().paths(path).build());
-        return metadata.providers().stream()
-            .map(SecureJar.Provider::serviceName)
-            .anyMatch(TransformerDiscovererConstants.SERVICES::contains);
+        return TransformerDiscovererConstants.shouldLoadInServiceLayer(path);
     }
 }

loader/src/main/java/net/neoforged/fml/loading/TransformerDiscovererConstants.java

@@ -5,16 +5,20 @@
 
 package net.neoforged.fml.loading;
 
+import cpw.mods.jarhandling.JarContentsBuilder;
+import cpw.mods.jarhandling.JarMetadata;
+import cpw.mods.jarhandling.SecureJar;
 import cpw.mods.modlauncher.api.IModuleLayerManager.Layer;
 import cpw.mods.modlauncher.serviceapi.ITransformerDiscoveryService;
 
+import java.nio.file.Path;
 import java.util.Set;
 
 /**
  * Defines a class containing constants which implementations of {@link ITransformerDiscoveryService}
  * may use.
  */
-public class TransformerDiscovererConstants {
+public final class TransformerDiscovererConstants {
     private TransformerDiscovererConstants() { }
 
     /**
@@ -29,4 +33,11 @@ private TransformerDiscovererConstants() { }
         "net.neoforged.fml.loading.ImmediateWindowProvider", // FIXME: remove this when removing the legacy ImmediateWindowProvider
         "net.neoforged.neoforgespi.earlywindow.ImmediateWindowProvider"
     );
+
+    public static boolean shouldLoadInServiceLayer(Path... path) {
+        JarMetadata metadata = JarMetadata.from(new JarContentsBuilder().paths(path).build());
+        return metadata.providers().stream()
+                .map(SecureJar.Provider::serviceName)
+                .anyMatch(SERVICES::contains);
+    }
 }

loader/src/main/java/net/neoforged/fml/loading/moddiscovery/MinecraftLocator.java

@@ -9,6 +9,7 @@
 import com.mojang.logging.LogUtils;
 import cpw.mods.jarhandling.JarContentsBuilder;
 import cpw.mods.jarhandling.SecureJar;
+import net.neoforged.fml.loading.ClasspathTransformerDiscoverer;
 import net.neoforged.fml.loading.FMLLoader;
 import net.neoforged.fml.loading.LogMarkers;
 import net.neoforged.neoforgespi.language.IModFileInfo;
@@ -47,7 +48,9 @@ public List<IModLocator.ModFileOrException> scanMods() {
                 .map(SecureJar::from)
                 .map(sj -> new ModFile(sj, this, ModFileParser::modsTomlParser))
                 .collect(Collectors.<IModFile>toList());
+        var otherModsExcluded = ClasspathTransformerDiscoverer.allExcluded();
         var othermods = baseMC.otherModPaths().stream()
+                .filter(p -> p.stream().noneMatch(otherModsExcluded::contains)) //We cannot load MOD_CLASSES from the classpath if they are loaded on the SERVICE layer.
                 .map(p -> createMod(p.toArray(Path[]::new)))
                 .filter(Objects::nonNull);
         artifacts.add(mcjar);

loader/src/main/java/net/neoforged/fml/loading/targets/CommonLaunchHandler.java

@@ -92,7 +92,7 @@ protected final List<Path> getFmlPaths(String[] classpath) {
             .toList();
     }
 
-    protected final Map<String, List<Path>> getModClasses() {
+    public static Map<String, List<Path>> getModClasses() {
         final String modClasses = Optional.ofNullable(System.getenv("MOD_CLASSES")).orElse("");
         LOGGER.debug(LogMarkers.CORE, "Got mod coordinates {} from env", modClasses);