Allow access widener conversion in NeoForge

src/main/java/net/fabricmc/loom/api/NeoForgeExtensionAPI.java

@@ -25,11 +25,30 @@
 package net.fabricmc.loom.api;
 
 import org.gradle.api.file.ConfigurableFileCollection;
+import org.gradle.api.provider.Property;
+import org.gradle.api.provider.SetProperty;
 
 /**
  * This is the NeoForge extension API available to build scripts.
  */
 public interface NeoForgeExtensionAPI {
+	/**
+	 * If true, {@linkplain LoomGradleExtensionAPI#getAccessWidenerPath() the project access widener file}
+	 * will be remapped to an access transformer file if set.
+	 *
+	 * @return the property
+	 */
+	Property<Boolean> getConvertAccessWideners();
+
+	/**
+	 * A set of additional access widener files that will be converted to access transformers
+	 * {@linkplain #getConvertAccessWideners() if enabled}. The files are specified as paths in jar files
+	 * (e.g. {@code path/to/my_aw.accesswidener}).
+	 *
+	 * @return the property
+	 */
+	SetProperty<String> getExtraAccessWideners();
+
 	/**
 	 * A collection of all project access transformers.
 	 * The collection should only contain AT files, and not directories or other files.

src/main/java/net/fabricmc/loom/extension/NeoForgeExtensionImpl.java

@@ -28,17 +28,33 @@
 
 import org.gradle.api.Project;
 import org.gradle.api.file.ConfigurableFileCollection;
+import org.gradle.api.provider.Property;
+import org.gradle.api.provider.SetProperty;
 
 import net.fabricmc.loom.api.NeoForgeExtensionAPI;
 
 public class NeoForgeExtensionImpl implements NeoForgeExtensionAPI {
+	private final Property<Boolean> convertAccessWideners;
+	private final SetProperty<String> extraAccessWideners;
 	private final ConfigurableFileCollection accessTransformers;
 
 	@Inject
 	public NeoForgeExtensionImpl(Project project) {
+		convertAccessWideners = project.getObjects().property(Boolean.class).convention(false);
+		extraAccessWideners = project.getObjects().setProperty(String.class).empty();
 		accessTransformers = project.getObjects().fileCollection();
 	}
 
+	@Override
+	public Property<Boolean> getConvertAccessWideners() {
+		return convertAccessWideners;
+	}
+
+	@Override
+	public SetProperty<String> getExtraAccessWideners() {
+		return extraAccessWideners;
+	}
+
 	@Override
 	public ConfigurableFileCollection getAccessTransformers() {
 		return accessTransformers;

src/main/java/net/fabricmc/loom/task/RemapTaskConfiguration.java

@@ -121,6 +121,10 @@ public void run() {
 						});
 					});
 				}
+			} else if (extension.isNeoForge()) {
+				if (PropertyUtil.getAndFinalize(extension.getNeoForge().getConvertAccessWideners())) {
+					Aw2At.setup(getProject(), (RemapJarTask) getTasks().getByName(REMAP_JAR_TASK_NAME));
+				}
 			}
 		});
 

src/main/java/net/fabricmc/loom/util/aw2at/Aw2At.java

@@ -78,7 +78,13 @@ public static void setup(Project project, RemapJarTask remapJar) {
 			remapJar.getAtAccessWideners().add(awName);
 		}
 
-		remapJar.getAtAccessWideners().addAll(extension.getForge().getExtraAccessWideners());
+		if (extension.isForge()) {
+			remapJar.getAtAccessWideners().addAll(extension.getForge().getExtraAccessWideners());
+		} else if (extension.isNeoForge()) {
+			remapJar.getAtAccessWideners().addAll(extension.getNeoForge().getExtraAccessWideners());
+		} else {
+			throw new IllegalStateException("Unexpected extension!");
+		}
 	}
 
 	/**