Add textifier functions to ASMAPI, helpful in debugging.

build.gradle

@@ -78,6 +78,7 @@ dependencies {
     implementation('org.ow2.asm:asm:7.2')
     implementation('org.ow2.asm:asm-commons:7.2')
     implementation('org.ow2.asm:asm-tree:7.2')
+    implementation('org.ow2.asm:asm-util:7.2')
     implementation('net.minecraftforge:forgespi:3.1.+')
     implementation('com.google.code.findbugs:jsr305:3.0.2')
 

src/main/java/net/minecraftforge/coremod/CoreModEngine.java

@@ -16,7 +16,8 @@ public class CoreModEngine {
     private static final Marker COREMOD = MarkerManager.getMarker("COREMOD");
     private List<CoreMod> coreMods = new ArrayList<>();
     static final Set<String> ALLOWED_PACKAGES = new HashSet<>(Arrays.asList(
-            "java.util.function"
+            "java.util.function",
+            "org.objectweb.asm.util" // ASM util has nice debugging things like Trace visitors
     ));
     static final Set<String> ALLOWED_CLASSES = new HashSet<>(Arrays.asList(
             "net.minecraftforge.coremod.api.ASMAPI","org.objectweb.asm.Opcodes",

src/main/java/net/minecraftforge/coremod/api/ASMAPI.java

@@ -5,10 +5,15 @@
 import net.minecraftforge.coremod.CoreModTracker;
 import org.objectweb.asm.Opcodes;
 import org.objectweb.asm.tree.*;
+import org.objectweb.asm.util.Textifier;
+import org.objectweb.asm.util.TraceClassVisitor;
+import org.objectweb.asm.util.TraceMethodVisitor;
 
 import javax.annotation.Nullable;
 import javax.script.ScriptException;
 import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.StringWriter;
 import java.lang.reflect.Modifier;
 import java.util.Iterator;
 import java.util.ListIterator;
@@ -305,4 +310,30 @@ public static Object loadData(String file) throws ScriptException, IOException {
     public static void log(String level, String message, Object... args) {
         CoreModTracker.log(level, message, args);
     }
+
+    public static String classNodeToString(ClassNode node) {
+        Textifier text = new Textifier();
+        node.accept(new TraceClassVisitor(null, text, null));
+        return toString(text);
+    }
+
+    public static String fieldNodeToString(FieldNode node) {
+        Textifier text = new Textifier();
+        node.accept(new TraceClassVisitor(null, text, null));
+        return toString(text);
+    }
+
+    public static String methodNodeToString(MethodNode node) {
+        Textifier text = new Textifier();
+        node.accept(new TraceMethodVisitor(text));
+        return toString(text);
+    }
+
+    private static String toString(Textifier text) {
+        StringWriter sw = new StringWriter();
+        PrintWriter pw = new PrintWriter(sw);
+        text.print(pw);
+        pw.flush();
+        return sw.toString();
+    }
 }