Example usage for org.objectweb.asm MethodVisitor visitVarInsn

List of usage examples for org.objectweb.asm MethodVisitor visitVarInsn

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Introduction

In this page you can find the example usage for org.objectweb.asm MethodVisitor visitVarInsn.

Prototype

public void visitVarInsn(final int opcode, final int var)

Source Link

Document

Visits a local variable instruction.

Usage

From source file:com.google.code.jconts.instrument.gen.ComputationClassGenerator.java

License:Apache License

private void generateConstructor(ClassVisitor cv) {
    final String name = info.computationClassName;
    final Type outerType = Type.getObjectType(info.owner);

    // Constructor have form either <init>(OuterClass this$0, State state)
    // or <init>(State state)
    String ctorDesc;/*from w  w w  .  j  a  v a  2 s .  co m*/
    if (info.isStatic()) {
        ctorDesc = Type.getMethodDescriptor(Type.VOID_TYPE, new Type[] { info.stateType });
    } else {
        cv.visitField(Opcodes.ACC_PRIVATE | Opcodes.ACC_FINAL, "this$0", 'L' + info.owner + ';', null, null);

        ctorDesc = Type.getMethodDescriptor(Type.VOID_TYPE, new Type[] { outerType, info.stateType });
    }

    // Generate constructor
    MethodVisitor mv = cv.visitMethod(0, CTOR_NAME, ctorDesc, null, null);
    mv.visitCode();
    Label start = new Label();
    Label end = new Label();
    mv.visitLabel(start);

    mv.visitVarInsn(Opcodes.ALOAD, 0);
    mv.visitMethodInsn(Opcodes.INVOKESPECIAL, OBJECT_NAME, CTOR_NAME, DEFAULT_CTOR_DESC);

    // Save state field
    mv.visitVarInsn(Opcodes.ALOAD, 0);
    mv.visitVarInsn(Opcodes.ALOAD, 1 + info.thisOffset);
    mv.visitFieldInsn(Opcodes.PUTFIELD, name, "state", stateDesc);

    // Save outer this
    if (!info.isStatic()) {
        mv.visitVarInsn(Opcodes.ALOAD, 0);
        mv.visitVarInsn(Opcodes.ALOAD, 1);
        mv.visitFieldInsn(Opcodes.PUTFIELD, name, "this$0", outerType.getDescriptor());
    }
    mv.visitInsn(Opcodes.RETURN);
    mv.visitLabel(end);

    mv.visitLocalVariable("this", 'L' + name + ';', signature, start, end, 0);
    if (!info.isStatic()) {
        mv.visitLocalVariable("this$0", outerType.getDescriptor(), null, start, end, 1);
    }
    mv.visitLocalVariable("state", stateDesc, null, start, end, 1 + info.thisOffset);

    mv.visitMaxs(2, 2 + info.thisOffset);
    mv.visitEnd();
}

From source file:com.google.code.jconts.instrument.gen.ComputationClassGenerator.java

License:Apache License

private void generateExecute(ClassVisitor cv) {
    final String name = info.computationClassName;
    final Type outerType = Type.getObjectType(info.owner);

    // Generate execute(Continuation<T> cont);
    MethodVisitor mv = cv.visitMethod(Opcodes.ACC_FINAL | Opcodes.ACC_PUBLIC, COMPUTATION_EXECUTE_NAME,
            COMPUTATION_EXECUTE_DESC, executeSignature(), null);
    mv.visitCode();/*from w ww . j  av  a  2  s .  com*/
    Label start = new Label();
    Label end = new Label();
    mv.visitLabel(start);

    // Load outer this
    if (!info.isStatic()) {
        mv.visitVarInsn(Opcodes.ALOAD, 0);
        mv.visitFieldInsn(Opcodes.GETFIELD, name, "this$0", outerType.getDescriptor());
    }

    // Load state field
    mv.visitVarInsn(Opcodes.ALOAD, 0);
    mv.visitFieldInsn(Opcodes.GETFIELD, name, "state", stateDesc);

    // state.continuation = continuation
    mv.visitVarInsn(Opcodes.ALOAD, 0);
    mv.visitFieldInsn(Opcodes.GETFIELD, name, "state", stateDesc);
    mv.visitVarInsn(Opcodes.ALOAD, 1);
    mv.visitFieldInsn(Opcodes.PUTFIELD, info.stateClassName, CONTINUATION_FIELD, CONTINUATION_DESC);

    // Initial state (0)
    mv.visitIntInsn(Opcodes.BIPUSH, 0);
    mv.visitMethodInsn(info.isStatic() ? Opcodes.INVOKESTATIC : Opcodes.INVOKEVIRTUAL, info.owner,
            info.name + "$async",
            Type.getMethodDescriptor(Type.VOID_TYPE, new Type[] { info.stateType, Type.INT_TYPE }));

    mv.visitInsn(Opcodes.RETURN);
    mv.visitLabel(end);

    mv.visitLocalVariable("this", 'L' + name + ';', signature, start, end, 0);
    if (!info.isStatic()) {
        mv.visitLocalVariable("this$0", outerType.getDescriptor(), null, start, end, 1);
    }

    SignatureWriter sign = new SignatureWriter();
    contSignature(sign);
    mv.visitLocalVariable("continuation", CONTINUATION_DESC, sign.toString(), start, end, 1 + info.thisOffset);

    mv.visitMaxs(3 + info.thisOffset, 2 + info.thisOffset);
    mv.visitEnd();
}

From source file:com.google.code.jconts.instrument.gen.ContinuationClassGenerator.java

License:Apache License

private void generateConstructor(ClassVisitor cv) {
    final String name = info.continuationClassName;
    final Type outerType = Type.getObjectType(info.owner);

    // Constructor have form either <init>(OuterClass this$0, State state,
    // int index)
    // or <init>(State state, int index)
    String ctorDesc;/*from  w w  w  .  ja  v  a2 s .c o m*/
    if (info.isStatic()) {
        ctorDesc = Type.getMethodDescriptor(Type.VOID_TYPE, new Type[] { info.stateType, Type.INT_TYPE });
    } else {
        cv.visitField(Opcodes.ACC_PRIVATE | Opcodes.ACC_FINAL, "this$0", 'L' + info.owner + ';', null, null);

        ctorDesc = Type.getMethodDescriptor(Type.VOID_TYPE,
                new Type[] { outerType, info.stateType, Type.INT_TYPE });
    }

    // Generate constructor
    MethodVisitor mv = cv.visitMethod(0, CTOR_NAME, ctorDesc, null, null);
    mv.visitCode();
    Label start = new Label();
    Label end = new Label();
    mv.visitLabel(start);

    mv.visitVarInsn(Opcodes.ALOAD, 0);
    mv.visitMethodInsn(Opcodes.INVOKESPECIAL, OBJECT_NAME, CTOR_NAME, DEFAULT_CTOR_DESC);

    // Save state field
    mv.visitVarInsn(Opcodes.ALOAD, 0);
    mv.visitVarInsn(Opcodes.ALOAD, 1 + info.thisOffset);
    mv.visitFieldInsn(Opcodes.PUTFIELD, name, "state", stateDesc);

    // Save index field
    mv.visitVarInsn(Opcodes.ALOAD, 0);
    mv.visitVarInsn(Opcodes.ILOAD, 2 + info.thisOffset);
    mv.visitFieldInsn(Opcodes.PUTFIELD, name, "index", "I");

    // Save outer this
    if (!info.isStatic()) {
        mv.visitVarInsn(Opcodes.ALOAD, 0);
        mv.visitVarInsn(Opcodes.ALOAD, 1);
        mv.visitFieldInsn(Opcodes.PUTFIELD, name, "this$0", outerType.getDescriptor());
    }
    mv.visitInsn(Opcodes.RETURN);
    mv.visitLabel(end);

    mv.visitLocalVariable("this", 'L' + name + ';', signature, start, end, 0);
    if (!info.isStatic()) {
        mv.visitLocalVariable("this$0", outerType.getDescriptor(), null, start, end, 1);
    }
    mv.visitLocalVariable("state", stateDesc, null, start, end, 1 + info.thisOffset);
    mv.visitLocalVariable("index", "I", null, start, end, 2 + info.thisOffset);

    mv.visitMaxs(2, 3 + info.thisOffset);
    mv.visitEnd();
}

From source file:com.google.code.jconts.instrument.gen.ContinuationClassGenerator.java

License:Apache License

private void generateExecute(ClassVisitor cv, boolean execute) {
    final String name = info.continuationClassName;
    final Type outerType = Type.getObjectType(info.owner);

    // Generate invoke(T result);
    String signature = null;//from   w ww. ja  va  2 s.  com
    if (execute) {
        SignatureWriter sign = new SignatureWriter();
        sign.visitParameterType().visitTypeVariable("T");
        sign.visitReturnType().visitBaseType('V'); // void
        signature = sign.toString();
    }
    MethodVisitor mv = cv.visitMethod(Opcodes.ACC_FINAL | Opcodes.ACC_PUBLIC,
            execute ? CONTINUATION_INVOKE_NAME : CONTINUATION_SET_EXCEPTION_NAME,
            execute ? CONTINUATION_INVOKE_DESC : CONTINUATION_SET_EXCEPTION_DESC, signature, null);
    mv.visitCode();
    Label start = new Label();
    Label end = new Label();
    mv.visitLabel(start);

    // Load outer this
    if (!info.isStatic()) {
        mv.visitVarInsn(Opcodes.ALOAD, 0);
        mv.visitFieldInsn(Opcodes.GETFIELD, name, "this$0", outerType.getDescriptor());
    }

    // state.result = result or state.exception = throwable
    mv.visitVarInsn(Opcodes.ALOAD, 0);
    mv.visitFieldInsn(Opcodes.GETFIELD, name, "state", stateDesc);
    mv.visitVarInsn(Opcodes.ALOAD, 1);
    mv.visitFieldInsn(Opcodes.PUTFIELD, info.stateClassName, execute ? "result" : "exception",
            execute ? OBJECT_DESC : THROWABLE_DESC);

    // Load state field
    mv.visitVarInsn(Opcodes.ALOAD, 0);
    mv.visitFieldInsn(Opcodes.GETFIELD, name, "state", stateDesc);

    // Continue from this index or index+1 (for exception)
    mv.visitVarInsn(Opcodes.ALOAD, 0);
    mv.visitFieldInsn(Opcodes.GETFIELD, name, "index", "I");
    if (!execute) {
        mv.visitInsn(Opcodes.ICONST_1);
        mv.visitInsn(Opcodes.IADD);
    }

    mv.visitMethodInsn(info.isStatic() ? Opcodes.INVOKESTATIC : Opcodes.INVOKEVIRTUAL, info.owner,
            info.name + "$async",
            Type.getMethodDescriptor(Type.VOID_TYPE, new Type[] { info.stateType, Type.INT_TYPE }));

    mv.visitInsn(Opcodes.RETURN);
    mv.visitLabel(end);

    mv.visitLocalVariable("this", 'L' + name + ';', signature, start, end, 0);
    if (!info.isStatic()) {
        mv.visitLocalVariable("this$0", outerType.getDescriptor(), null, start, end, 1);
    }
    mv.visitLocalVariable("result", OBJECT_DESC, "TT;", start, end, 1 + info.thisOffset);

    mv.visitMaxs(3 + info.thisOffset + (execute ? 0 : 1), 2 + info.thisOffset);
    mv.visitEnd();
}

From source file:com.google.code.jconts.instrument.gen.StateClassGenerator.java

License:Apache License

public void accept(TransformationContext context) {
    ClassVisitor cv = context.writer();/*from ww w .ja  v a2  s  .c o m*/

    final String name = info.stateClassName;

    cv.visit(Opcodes.V1_6, Opcodes.ACC_FINAL /*| Opcodes.ACC_SYNTHETIC*/, name, null, OBJECT_NAME, null);

    cv.visitSource(info.ownerSource, null);
    cv.visitOuterClass(info.owner, null, null);

    cv.visitField(0/*Opcodes.ACC_SYNTHETIC*/, CONTINUATION_FIELD, CONTINUATION_DESC,
            'L' + CONTINUATION_NAME + '<' + info.valueSignature + ">;", null);

    // Local variables state
    List<String> names = info.tracker.getFieldNames();
    List<Type> types = info.tracker.getFieldTypes();
    for (int i = 0; i < names.size(); ++i) {
        cv.visitField(0/*Opcodes.ACC_SYNTHETIC*/, names.get(i), types.get(i).getDescriptor(), null, null);
    }

    // Return value variable
    cv.visitField(0/*Opcodes.ACC_SYNTHETIC*/, "result", OBJECT_DESC, null, null);
    cv.visitField(0/*Opcodes.ACC_SYNTHETIC*/, "exception", THROWABLE_DESC, null, null);

    // Generate constructor
    MethodVisitor mv = cv.visitMethod(0, CTOR_NAME, DEFAULT_CTOR_DESC, null, null);
    mv.visitCode();
    Label start = new Label();
    Label end = new Label();
    mv.visitLabel(start);
    mv.visitLineNumber(0, start);

    mv.visitVarInsn(Opcodes.ALOAD, 0);
    mv.visitMethodInsn(Opcodes.INVOKESPECIAL, OBJECT_NAME, CTOR_NAME, DEFAULT_CTOR_DESC);
    mv.visitInsn(Opcodes.RETURN);
    mv.visitLabel(end);

    mv.visitLocalVariable("this", 'L' + name + ';', null, start, end, 0);

    mv.visitMaxs(1, 1);
    mv.visitEnd();

    cv.visitEnd();
}

From source file:com.google.code.jconts.instrument.gen.TramplineMethodGenerator.java

License:Apache License

public void accept(ClassVisitor cv) {
    MethodVisitor mv = cv.visitMethod(info.access, info.name, info.desc, info.signature, info.exceptions);
    mv.visitCode();/* w ww .j  a va 2 s . co  m*/
    mv.visitTypeInsn(Opcodes.NEW, info.computationClassName);
    mv.visitInsn(Opcodes.DUP);

    // "this' for new Computation(this, state)
    if (!info.isStatic()) {
        mv.visitVarInsn(Opcodes.ALOAD, 0);
    }

    // new State()
    mv.visitTypeInsn(Opcodes.NEW, info.stateClassName);
    mv.visitInsn(Opcodes.DUP);
    mv.visitMethodInsn(Opcodes.INVOKESPECIAL, info.stateClassName, CTOR_NAME, DEFAULT_CTOR_DESC);

    // state.varX = argX
    String[] names = info.entryLocalsVars;
    for (int i = 0; i < info.entryLocals.length; ++i) {
        mv.visitInsn(Opcodes.DUP);
        mv.visitVarInsn(info.entryLocals[i].getOpcode(Opcodes.ILOAD), i + info.thisOffset);
        mv.visitFieldInsn(Opcodes.PUTFIELD, info.stateClassName, names[i], info.entryLocals[i].getDescriptor());
    }

    // new Computation(this, state);
    String ctorDesc;
    if (info.isStatic()) {
        ctorDesc = Type.getMethodDescriptor(Type.VOID_TYPE, new Type[] { info.stateType });
    } else {
        ctorDesc = Type.getMethodDescriptor(Type.VOID_TYPE,
                new Type[] { Type.getObjectType(info.owner), info.stateType });
    }
    mv.visitMethodInsn(Opcodes.INVOKESPECIAL, info.computationClassName, CTOR_NAME, ctorDesc);

    mv.visitInsn(Opcodes.ARETURN);
    mv.visitMaxs(info.isStatic() ? 5 : 6,
            info.isStatic() ? info.entryLocals.length : info.entryLocals.length + 1);
    mv.visitEnd();
}

From source file:com.google.devtools.build.android.desugar.Bug62060793TestDataGenerator.java

License:Open Source License

private static byte[] createClass() {
    ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);
    MethodVisitor mv;
    cw.visit(V1_8, ACC_PUBLIC | ACC_SUPER, CLASS_NAME, null, "java/lang/Object", null);

    cw.visitInnerClass(INTERFACE_TYPE_NAME, CLASS_NAME, "Interface",
            ACC_PUBLIC | ACC_STATIC | ACC_ABSTRACT | ACC_INTERFACE);

    cw.visitInnerClass("java/lang/invoke/MethodHandles$Lookup", "java/lang/invoke/MethodHandles", "Lookup",
            ACC_PUBLIC | ACC_FINAL | ACC_STATIC);

    {/*from www  .  j  ava  2 s . c  om*/
        mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
        mv.visitCode();
        mv.visitVarInsn(ALOAD, 0);
        mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
        mv.visitInsn(RETURN);
        mv.visitEnd();
    }
    {
        mv = cw.visitMethod(ACC_PRIVATE | ACC_STATIC, "method", "(Ljava/lang/String;)Ljava/lang/String;", null,
                null);
        mv.visitParameter("str", 0);
        mv.visitCode();
        mv.visitVarInsn(ALOAD, 0);
        mv.visitInsn(ARETURN);
        mv.visitEnd();
    }
    {
        mv = cw.visitMethod(ACC_PRIVATE | ACC_STATIC, "method",
                "(ZCBFDJISLjava/lang/Object;[Ljava/lang/Object;Ljava/lang/String;)Ljava/lang/String;", null,
                null);
        mv.visitParameter("bool", 0);
        mv.visitParameter("c", 0);
        mv.visitParameter("b", 0);
        mv.visitParameter("f", 0);
        mv.visitParameter("d", 0);
        mv.visitParameter("l", 0);
        mv.visitParameter("i", 0);
        mv.visitParameter("s", 0);
        mv.visitParameter("o", 0);
        mv.visitParameter("array", 0);
        mv.visitParameter("str", 0);
        mv.visitCode();
        mv.visitVarInsn(ALOAD, 10);
        mv.visitMethodInsn(INVOKESTATIC, "java/lang/String", "valueOf",
                "(Ljava/lang/Object;)Ljava/lang/String;", false);
        mv.visitVarInsn(ASTORE, 13);
        mv.visitVarInsn(ALOAD, 11);
        Label l0 = new Label();
        mv.visitJumpInsn(IFNONNULL, l0);
        mv.visitInsn(ICONST_1);
        Label l1 = new Label();
        mv.visitJumpInsn(GOTO, l1);
        mv.visitLabel(l0);
        mv.visitFrame(Opcodes.F_APPEND, 1, new Object[] { "java/lang/String" }, 0, null);
        mv.visitInsn(ICONST_0);
        mv.visitLabel(l1);
        mv.visitFrame(Opcodes.F_SAME1, 0, null, 1, new Object[] { Opcodes.INTEGER });
        mv.visitVarInsn(ISTORE, 14);
        mv.visitIntInsn(BIPUSH, 91);
        mv.visitVarInsn(ALOAD, 12);
        mv.visitMethodInsn(INVOKESTATIC, "java/lang/String", "valueOf",
                "(Ljava/lang/Object;)Ljava/lang/String;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "length", "()I", false);
        mv.visitInsn(IADD);
        mv.visitVarInsn(ALOAD, 13);
        mv.visitMethodInsn(INVOKESTATIC, "java/lang/String", "valueOf",
                "(Ljava/lang/Object;)Ljava/lang/String;", false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/String", "length", "()I", false);
        mv.visitInsn(IADD);
        mv.visitTypeInsn(NEW, "java/lang/StringBuilder");
        mv.visitInsn(DUP_X1);
        mv.visitInsn(SWAP);
        mv.visitMethodInsn(INVOKESPECIAL, "java/lang/StringBuilder", "<init>", "(I)V", false);
        mv.visitVarInsn(ALOAD, 12);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append",
                "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false);
        mv.visitVarInsn(ILOAD, 0);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Z)Ljava/lang/StringBuilder;",
                false);
        mv.visitVarInsn(ILOAD, 1);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(C)Ljava/lang/StringBuilder;",
                false);
        mv.visitVarInsn(ILOAD, 2);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(I)Ljava/lang/StringBuilder;",
                false);
        mv.visitVarInsn(FLOAD, 3);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(F)Ljava/lang/StringBuilder;",
                false);
        mv.visitVarInsn(DLOAD, 4);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(D)Ljava/lang/StringBuilder;",
                false);
        mv.visitVarInsn(LLOAD, 6);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(J)Ljava/lang/StringBuilder;",
                false);
        mv.visitVarInsn(ILOAD, 8);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(I)Ljava/lang/StringBuilder;",
                false);
        mv.visitVarInsn(ILOAD, 9);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(I)Ljava/lang/StringBuilder;",
                false);
        mv.visitVarInsn(ALOAD, 13);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append",
                "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false);
        mv.visitVarInsn(ILOAD, 14);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Z)Ljava/lang/StringBuilder;",
                false);
        mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "toString", "()Ljava/lang/String;", false);
        mv.visitInsn(ARETURN);
        mv.visitEnd();
    }
    {
        mv = cw.visitMethod(ACC_PUBLIC | ACC_STATIC, "lambdaWithConstantArguments",
                "()L" + INTERFACE_TYPE_NAME + ";", null, null);
        mv.visitCode();
        mv.visitInsn(ICONST_0);
        mv.visitInsn(ICONST_1);
        mv.visitInsn(ICONST_2);
        mv.visitInsn(FCONST_0);
        mv.visitInsn(DCONST_0);
        mv.visitInsn(LCONST_0);
        mv.visitInsn(ICONST_4);
        mv.visitIntInsn(SIPUSH, 9);
        mv.visitInsn(ACONST_NULL);
        mv.visitInsn(ACONST_NULL);
        mv.visitInvokeDynamicInsn("call",
                "(ZCBFDJISLjava/lang/Object;[Ljava/lang/Object;)L" + INTERFACE_TYPE_NAME + ";",
                new Handle(Opcodes.H_INVOKESTATIC, "java/lang/invoke/LambdaMetafactory", "metafactory",
                        "(Ljava/lang/invoke/MethodHandles$Lookup;"
                                + "Ljava/lang/String;Ljava/lang/invoke/MethodType;"
                                + "Ljava/lang/invoke/MethodType;" + "Ljava/lang/invoke/MethodHandle;"
                                + "Ljava/lang/invoke/MethodType;" + ")Ljava/lang/invoke/CallSite;",
                        false),
                new Object[] { Type.getType("(Ljava/lang/String;)Ljava/lang/String;"),
                        new Handle(Opcodes.H_INVOKESTATIC, CLASS_NAME, "method",
                                "(ZCBFDJISLjava/lang/Object;[Ljava/lang/Object;Ljava/lang/String;"
                                        + ")Ljava/lang/String;",
                                false),
                        Type.getType("(Ljava/lang/String;)Ljava/lang/String;") });
        mv.visitInsn(ARETURN);
        mv.visitEnd();
    }

    cw.visitEnd();

    return cw.toByteArray();
}

From source file:com.google.devtools.build.android.desugar.CoreLibrarySupport.java

License:Open Source License

private void makeDispatchHelperMethod(ClassVisitor helper, EmulatedMethod method,
        ImmutableList<Class<?>> typechecks) {
    checkArgument(method.owner().isInterface());
    String owner = method.owner().getName().replace('.', '/');
    Type methodType = Type.getMethodType(method.descriptor());
    String companionDesc = InterfaceDesugaring.companionDefaultMethodDescriptor(owner, method.descriptor());
    MethodVisitor dispatchMethod = helper.visitMethod(method.access() | Opcodes.ACC_STATIC, method.name(),
            companionDesc, /*signature=*/ null, // signature is invalid due to extra "receiver" argument
            method.exceptions().toArray(EMPTY_LIST));

    dispatchMethod.visitCode();//from ww w.  j  a  v  a2 s  .  c o  m
    {
        // See if the receiver might come with its own implementation of the method, and call it.
        // We do this by testing for the interface type created by EmulatedInterfaceRewriter
        Label fallthrough = new Label();
        String emulationInterface = renameCoreLibrary(owner);
        dispatchMethod.visitVarInsn(Opcodes.ALOAD, 0); // load "receiver"
        dispatchMethod.visitTypeInsn(Opcodes.INSTANCEOF, emulationInterface);
        dispatchMethod.visitJumpInsn(Opcodes.IFEQ, fallthrough);
        dispatchMethod.visitVarInsn(Opcodes.ALOAD, 0); // load "receiver"
        dispatchMethod.visitTypeInsn(Opcodes.CHECKCAST, emulationInterface);

        visitLoadArgs(dispatchMethod, methodType, 1 /* receiver already loaded above */);
        dispatchMethod.visitMethodInsn(Opcodes.INVOKEINTERFACE, emulationInterface, method.name(),
                method.descriptor(), /*itf=*/ true);
        dispatchMethod.visitInsn(methodType.getReturnType().getOpcode(Opcodes.IRETURN));

        dispatchMethod.visitLabel(fallthrough);
        // Trivial frame for the branch target: same empty stack as before
        dispatchMethod.visitFrame(Opcodes.F_SAME, 0, EMPTY_FRAME, 0, EMPTY_FRAME);
    }

    // Next, check for subtypes with specialized implementations and call them
    for (Class<?> tested : typechecks) {
        Label fallthrough = new Label();
        String testedName = tested.getName().replace('.', '/');
        // In case of a class this must be a member move; for interfaces use the companion.
        String target = tested.isInterface() ? InterfaceDesugaring.getCompanionClassName(testedName)
                : checkNotNull(memberMoves.get(rewriter.unprefix(testedName) + '#' + method.name()));
        dispatchMethod.visitVarInsn(Opcodes.ALOAD, 0); // load "receiver"
        dispatchMethod.visitTypeInsn(Opcodes.INSTANCEOF, testedName);
        dispatchMethod.visitJumpInsn(Opcodes.IFEQ, fallthrough);
        dispatchMethod.visitVarInsn(Opcodes.ALOAD, 0); // load "receiver"
        dispatchMethod.visitTypeInsn(Opcodes.CHECKCAST, testedName); // make verifier happy

        visitLoadArgs(dispatchMethod, methodType, 1 /* receiver already loaded above */);
        dispatchMethod.visitMethodInsn(Opcodes.INVOKESTATIC, target, method.name(),
                InterfaceDesugaring.companionDefaultMethodDescriptor(testedName, method.descriptor()),
                /*itf=*/ false);
        dispatchMethod.visitInsn(methodType.getReturnType().getOpcode(Opcodes.IRETURN));

        dispatchMethod.visitLabel(fallthrough);
        // Trivial frame for the branch target: same empty stack as before
        dispatchMethod.visitFrame(Opcodes.F_SAME, 0, EMPTY_FRAME, 0, EMPTY_FRAME);
    }

    // Call static type's default implementation in companion class
    dispatchMethod.visitVarInsn(Opcodes.ALOAD, 0); // load "receiver"
    visitLoadArgs(dispatchMethod, methodType, 1 /* receiver already loaded above */);
    dispatchMethod.visitMethodInsn(Opcodes.INVOKESTATIC, InterfaceDesugaring.getCompanionClassName(owner),
            method.name(), companionDesc, /*itf=*/ false);
    dispatchMethod.visitInsn(methodType.getReturnType().getOpcode(Opcodes.IRETURN));

    dispatchMethod.visitMaxs(0, 0);
    dispatchMethod.visitEnd();
}

From source file:com.google.devtools.build.android.desugar.CoreLibrarySupport.java

License:Open Source License

/**
 * Emits instructions to load a method's parameters as arguments of a method call assumed to have
 * compatible descriptor, starting at the given local variable slot.
 *//* w  ww. j av a 2 s  . c  o m*/
private static void visitLoadArgs(MethodVisitor dispatchMethod, Type neededType, int slot) {
    for (Type arg : neededType.getArgumentTypes()) {
        dispatchMethod.visitVarInsn(arg.getOpcode(Opcodes.ILOAD), slot);
        slot += arg.getSize();
    }
}

From source file:com.google.devtools.build.android.desugar.LambdaDesugaring.java

License:Open Source License

@Override
public void visitEnd() {
    for (Map.Entry<Handle, MethodReferenceBridgeInfo> bridge : bridgeMethods.entrySet()) {
        Handle original = bridge.getKey();
        Handle neededMethod = bridge.getValue().bridgeMethod();
        checkState(//from  w ww . j a  v a  2s  .c  o  m
                neededMethod.getTag() == Opcodes.H_INVOKESTATIC
                        || neededMethod.getTag() == Opcodes.H_INVOKEVIRTUAL,
                "Cannot generate bridge method %s to reach %s", neededMethod, original);
        checkState(bridge.getValue().referenced() != null, "Need referenced method %s to generate bridge %s",
                original, neededMethod);

        int access = Opcodes.ACC_BRIDGE | Opcodes.ACC_SYNTHETIC | Opcodes.ACC_FINAL;
        if (neededMethod.getTag() == Opcodes.H_INVOKESTATIC) {
            access |= Opcodes.ACC_STATIC;
        }
        MethodVisitor bridgeMethod = super.visitMethod(access, neededMethod.getName(), neededMethod.getDesc(),
                (String) null, toInternalNames(bridge.getValue().referenced().getExceptionTypes()));

        // Bridge is a factory method calling a constructor
        if (original.getTag() == Opcodes.H_NEWINVOKESPECIAL) {
            bridgeMethod.visitTypeInsn(Opcodes.NEW, original.getOwner());
            bridgeMethod.visitInsn(Opcodes.DUP);
        }

        int slot = 0;
        if (neededMethod.getTag() != Opcodes.H_INVOKESTATIC) {
            bridgeMethod.visitVarInsn(Opcodes.ALOAD, slot++);
        }
        Type neededType = Type.getMethodType(neededMethod.getDesc());
        for (Type arg : neededType.getArgumentTypes()) {
            bridgeMethod.visitVarInsn(arg.getOpcode(Opcodes.ILOAD), slot);
            slot += arg.getSize();
        }
        bridgeMethod.visitMethodInsn(invokeOpcode(original), original.getOwner(), original.getName(),
                original.getDesc(), original.isInterface());
        bridgeMethod.visitInsn(neededType.getReturnType().getOpcode(Opcodes.IRETURN));

        bridgeMethod.visitMaxs(0, 0); // rely on class writer to compute these
        bridgeMethod.visitEnd();
    }
    super.visitEnd();
}