New Mixin Fixer system

src/main/java/me/modmuss50/optifabric/compat/MixinFixerExtension.java

@@ -0,0 +1,108 @@
+package me.modmuss50.optifabric.compat;
+
+import me.modmuss50.optifabric.compat.fix.ModMixinFixer;
+import me.modmuss50.optifabric.mod.OptifabricError;
+import me.modmuss50.optifabric.mod.OptifabricSetup;
+import me.modmuss50.optifabric.util.MixinInternals;
+import me.modmuss50.optifabric.util.MixinUtils;
+import org.apache.commons.lang3.tuple.Pair;
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.tree.*;
+import org.spongepowered.asm.mixin.MixinEnvironment;
+import org.spongepowered.asm.mixin.extensibility.IMixinInfo;
+import org.spongepowered.asm.mixin.injection.throwables.InjectionError;
+import org.spongepowered.asm.mixin.transformer.ClassInfo;
+import org.spongepowered.asm.mixin.transformer.ext.IExtension;
+import org.spongepowered.asm.mixin.transformer.ext.ITargetClassContext;
+
+import java.util.*;
+import java.util.stream.Collectors;
+
+public class MixinFixerExtension implements IExtension {
+	private static final Set<ClassNode> PRE_MIXINS = Collections.newSetFromMap(new WeakHashMap<>());
+	private static final Set<ClassNode> POST_MIXINS = Collections.newSetFromMap(new WeakHashMap<>());
+	private static final HashMap<String, Boolean> CLASS_INFO_UPDATES = new HashMap<>();
+
+	@Override
+	public boolean checkActive(MixinEnvironment environment) {
+		return true;
+	}
+
+	@Override
+	public void preApply(ITargetClassContext context) {
+		if (OptifabricError.hasError()) return;
+		for (Pair<IMixinInfo, ClassNode> pair : MixinInternals.getMixinsFor(context)) {
+			prepareMixin(pair.getLeft(), pair.getRight());
+		}
+		updateClassInfo(context.getClassInfo(), context.getClassNode());
+	}
+
+	@Override
+	public void postApply(ITargetClassContext context) {
+		for (Pair<IMixinInfo, ClassNode> pair : MixinInternals.getMixinsFor(context)) {
+			handleErrorInjectors(pair.getLeft(), pair.getRight(), context);
+		}
+	}
+
+	@Override
+	public void export(MixinEnvironment env, String name, boolean force, ClassNode classNode) {
+
+	}
+
+	private static void prepareMixin(IMixinInfo mixinInfo, ClassNode mixinNode) {
+		if (PRE_MIXINS.contains(mixinNode)) {
+			// Don't scan the whole class again.
+			return;
+		}
+		MixinNodeTransformer transformer = new MixinNodeTransformer(mixinInfo, mixinNode);
+		ModMixinFixer.INSTANCE.getFixers(mixinInfo).forEach(fixer -> fixer.fix(transformer));
+		if (transformer.shouldUpdateClassInfo()) {
+			mixinInfo.getTargetClasses().forEach(target -> CLASS_INFO_UPDATES.put(target, false));
+		}
+		PRE_MIXINS.add(mixinNode);
+	}
+
+	public void updateClassInfo(ClassInfo info, ClassNode node) {
+		if (!CLASS_INFO_UPDATES.getOrDefault(info.getName(), true)) {
+			MixinUtils.completeClassInfo(info, node.methods);
+			CLASS_INFO_UPDATES.put(info.getName(), true);
+		}
+	}
+
+	//this could use some refactoring
+	private static void handleErrorInjectors(IMixinInfo mixinInfo, ClassNode mixinNode, ITargetClassContext context) {
+		if (POST_MIXINS.contains(mixinNode)) {
+			return;
+		}
+		ClassNode classNode = context.getClassNode();
+
+		List<String> methods = classNode.methods.stream().map(method -> method.name).collect(Collectors.toList());
+		//check for error methods
+		for (MethodNode method : classNode.methods) {
+			if (method.name.endsWith("$missing") && methods.stream().anyMatch(name -> (name + "$missing").equals(method.name))) {
+				for (AbstractInsnNode insn : method.instructions) {
+					if (insn instanceof LdcInsnNode) {
+						String error = (String) ((LdcInsnNode) insn).cst;
+						if (!OptifabricError.hasError()) {
+							OptifabricError.setError(new InjectionError(error), getError(mixinInfo, method));
+							OptifabricError.modError = true;
+						}
+						break;
+					}
+				}
+				OptifabricSetup.LOGGER.warn("Removed InjectionException from Error Injector method " + method.name);
+				method.instructions.clear();
+				method.instructions.add(new InsnNode(Opcodes.RETURN));
+			}
+		}
+		POST_MIXINS.add(mixinNode);
+	}
+
+	private static String getError(IMixinInfo mixinInfo, MethodNode method) {
+		boolean compat = !ModMixinFixer.INSTANCE.getFixers(mixinInfo).isEmpty();
+		return String.format("Injector method %s in %s couldn't apply due to " +
+				(compat ? "outdated compatibility patch" : "missing compatibility patch!") +
+				" Please report this issue.",
+				method.name, mixinInfo);
+	}
+}