MetaClassInstumentor.java

package org.codehaus.groovy.gjit.agent.instrumentor;

import java.util.Stack;

import org.objectweb.asm.ClassAdapter;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.MethodAdapter;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;

public class MetaClassInstumentor extends ClassAdapter {

    class AMethodAdapter extends MethodAdapter implements Opcodes {

        private Stack<Integer> params = new Stack<Integer>();
        private String mname;

        public AMethodAdapter(String name, MethodVisitor mv) {
            super(mv);
            this.mname = name;
        }

        @Override
        public void visitVarInsn(int opcode, int var) {
            // keep track of ALOAD x to use in visitMethodInsn
            if(opcode==ALOAD) params.push(var);
            super.visitVarInsn(opcode, var);
        }

        @Override
        public void visitMethodInsn(int opcode, String owner, String name,String desc) {
            if(opcode == INVOKESPECIAL) {
                if(name.equals("getMethodWithCachingInternal")) {
                    if(desc.equals("(Ljava/lang/Class;Lorg/codehaus/groovy/runtime/callsite/CallSite;[Ljava/lang/Class;)Lgroovy/lang/MetaMethod;")) {
                        super.visitMethodInsn(opcode, owner, name, desc);
                        params.pop(); // params
                        mv.visitInsn(DUP); // dup result (MetaMethod)
                        if(mname.equals("createPojoCallSite")) {
                            int arg1 = params.pop(); // site
                            mv.visitVarInsn(ALOAD, 0);
                            mv.visitMethodInsn(INVOKEVIRTUAL, "groovy/lang/MetaClassImpl", "getTheClass", "()Ljava/lang/Class;");
                            mv.visitVarInsn(ALOAD, arg1);
                        } else if(mname.equals("createPogoCallSite")) {
                            int arg1 = params.pop(); // site
                            mv.visitVarInsn(ALOAD, 0);
                            mv.visitFieldInsn(GETFIELD, "groovy/lang/MetaClassImpl", "theClass", "Ljava/lang/Class;");
                            mv.visitVarInsn(ALOAD, arg1);
                        } else {
                            int arg1 = params.pop(); // site
                            int arg0 = params.pop(); // sender
                            mv.visitVarInsn(ALOAD, arg0);
                            mv.visitVarInsn(ALOAD, arg1);
                        }
                        // public static record(Lgroovy/lang/MetaMethod;Ljava/lang/Class;Lorg/codehaus/groovy/runtime/callsite/CallSite;)V
                        mv.visitMethodInsn(INVOKESTATIC,
                                "org/codehaus/groovy/gjit/db/SiteTypeHelper",
                                "record",
                                "(Lgroovy/lang/MetaMethod;Ljava/lang/Class;Lorg/codehaus/groovy/runtime/callsite/CallSite;)V");
                        return;
                    }
                }
            }
            super.visitMethodInsn(opcode, owner, name, desc);
        }
    }

    public MetaClassInstumentor(ClassVisitor cv) {
        super(cv);
    }

    @Override
    public MethodVisitor visitMethod(int access, String name, String desc,
            String signature, String[] exceptions) {
        if(name.equals("createPogoCallCurrentSite") ||
            name.equals("createPogoCallSite") ||
            name.equals("createPojoCallSite")) {
            return new AMethodAdapter(name, super.visitMethod(access, name, desc, signature, exceptions));
        }
        return super.visitMethod(access, name, desc, signature, exceptions);
    }
}