Java Code Examples for org.objectweb.asm.commons.GeneratorAdapter#visitCode()

private static void defineDefaultConstructor(ClassWriter cw, Type proxyType, Type superType)
{
    GeneratorAdapter mg = new GeneratorAdapter(Opcodes.ACC_PUBLIC,
            new Method("<init>", Type.VOID_TYPE, new Type[]{ }),
            null,
            null,
            cw);

    mg.visitCode();

    // invoke super constructor
    mg.loadThis();
    mg.invokeConstructor(superType, Method.getMethod("void <init> ()"));
    mg.returnValue();
    mg.endMethod();

    mg.visitEnd();
}
 

private static void defineSuperAccessorMethod(ClassWriter cw, java.lang.reflect.Method method, Type superType,
        String superAccessorMethodSuffix) 
{
    Method originalAsmMethod = Method.getMethod(method);
    Method newAsmMethod = new Method(method.getName() + superAccessorMethodSuffix,
            originalAsmMethod.getReturnType(),
            originalAsmMethod.getArgumentTypes());
    GeneratorAdapter mg = new GeneratorAdapter(Opcodes.ACC_PUBLIC, newAsmMethod, null, null, cw);
    
    mg.visitCode();
    
    // call super method
    mg.loadThis();
    mg.loadArgs();
    mg.visitMethodInsn(Opcodes.INVOKESPECIAL,
            superType.getInternalName(),
            method.getName(),
            Type.getMethodDescriptor(method),
            false);
    mg.returnValue();
    
    // finish the method
    mg.endMethod();
    mg.visitMaxs(10, 10);
    mg.visitEnd();
}
 

private static void generateConstructor(ClassVisitor cv) {
    GeneratorAdapter mv = new GeneratorAdapter(ACC_PUBLIC, EMPTY_CONSTRUCTOR, null, null, cv);
    mv.visitCode();
    mv.loadThis();
    mv.invokeConstructor(TEST_THREAD_EXECUTION_TYPE, TEST_THREAD_EXECUTION_CONSTRUCTOR);
    mv.visitInsn(RETURN);
    mv.visitMaxs(1, 1);
    mv.visitEnd();
}
 

@RequiresNonNull("type")
private void overrideAndWeaveInheritedMethod(AnalyzedMethod inheritedMethod) {
    String superName = analyzedClass.superName();
    // superName is null only for java.lang.Object which doesn't inherit anything
    // so safe to assume superName not null here
    checkNotNull(superName);
    String[] exceptions = new String[inheritedMethod.exceptions().size()];
    for (int i = 0; i < inheritedMethod.exceptions().size(); i++) {
        exceptions[i] = ClassNames.toInternalName(inheritedMethod.exceptions().get(i));
    }
    List<Advice> advisors = removeSuperseded(inheritedMethod.advisors());
    MethodVisitor mv = cw.visitMethod(ACC_PUBLIC, inheritedMethod.name(),
            inheritedMethod.getDesc(), inheritedMethod.signature(), exceptions);
    mv = visitMethodWithAdvice(mv, ACC_PUBLIC, inheritedMethod.name(),
            inheritedMethod.getDesc(), advisors);
    checkNotNull(mv);
    GeneratorAdapter mg = new GeneratorAdapter(mv, ACC_PUBLIC, inheritedMethod.name(),
            inheritedMethod.getDesc());
    mg.visitCode();
    mg.loadThis();
    mg.loadArgs();
    Type superType = Type.getObjectType(ClassNames.toInternalName(superName));
    // method is called invokeConstructor, but should really be called invokeSpecial
    Method method = new Method(inheritedMethod.name(), inheritedMethod.getDesc());
    mg.invokeConstructor(superType, method);
    mg.returnValue();
    mg.endMethod();
}
 

@Override
public void visitEnd() {
    if (onBeforeMethodVisitor != null) {
        int access = onBeforeMethodVisitor.access;
        String name = onBeforeMethodVisitor.name;
        String descriptor = "(Z" + onBeforeMethodVisitor.descriptor.substring(1);
        String signature = onBeforeMethodVisitor.signature;
        String[] exceptions = onBeforeMethodVisitor.exceptions;
        GeneratorAdapter mv = new GeneratorAdapter(
                cw.visitMethod(access, name, descriptor, signature, exceptions), access, name,
                descriptor);
        mv.visitCode();
        mv.visitVarInsn(ILOAD, 0);
        Label endWithDefaultLabel = new Label();
        mv.visitJumpInsn(IFEQ, endWithDefaultLabel);
        mv.loadArgs(1, mv.getArgumentTypes().length - 1);
        mv.visitMethodInsn(INVOKESTATIC, checkNotNull(className), name,
                onBeforeMethodVisitor.descriptor, false);
        mv.returnValue();

        mv.visitLabel(endWithDefaultLabel);
        mv.visitFrame(F_NEW, 0, new Object[0], 0, new Object[0]);
        if (mv.getReturnType().getSort() != Type.VOID) {
            // return value will be ignored when !enabled, but need to return something
            WeavingMethodVisitor.pushDefault(mv, mv.getReturnType());
        }
        mv.returnValue();
        mv.endMethod();
    }
    super.visitEnd();
}
 

/***
 * Inserts a trampoline to this class so that the updated methods can make calls to
 * constructors.
 * <p>
 * <p/>
 * Pseudo code for this trampoline:
 * <code>
 * ClassName(Object[] args, Marker unused) {
 * String name = (String) args[0];
 * if (name.equals(
 * "java/lang/ClassName.(Ljava/lang/String;Ljava/lang/Object;)Ljava/lang/Object;")) {
 * this((String)arg[1], arg[2]);
 * return
 * }
 * if (name.equals("SuperClassName.(Ljava/lang/String;I)V")) {
 * super((String)arg[1], (int)arg[2]);
 * return;
 * }
 * ...
 * StringBuilder $local1 = new StringBuilder();
 * $local1.append("Method not found ");
 * $local1.append(name);
 * $local1.append(" in " $classType $super implementation");
 * throw new $package/InstantReloadException($local1.toString());
 * }
 * </code>
 */
private void createDispatchingThis() {
    // Gather all methods from itself and its superclasses to generate a giant constructor
    // implementation.
    // This will work fine as long as we don't support adding constructors to classes.
    final Map<String, MethodNode> uniqueMethods = new HashMap<String, MethodNode>();

    addAllNewConstructors(uniqueMethods, classNode, true /*keepPrivateConstructors*/);
    for (ClassNode parentNode : parentNodes) {
        addAllNewConstructors(uniqueMethods, parentNode, false /*keepPrivateConstructors*/);
    }

    int access = Opcodes.ACC_PUBLIC | Opcodes.ACC_SYNTHETIC;

    Method m = new Method(AsmUtils.CONSTRUCTOR,
            ConstructorArgsRedirection.DISPATCHING_THIS_SIGNATURE);
    MethodVisitor visitor = super.visitMethod(0, m.getName(), m.getDescriptor(), null, null);
    final GeneratorAdapter mv = new GeneratorAdapter(access, m, visitor);

    mv.visitCode();
    // Mark this code as redirection code
    Label label = new Label();
    mv.visitLineNumber(0, label);

    // Get and store the constructor canonical name.
    mv.visitVarInsn(Opcodes.ALOAD, 1);
    mv.push(0);
    mv.visitInsn(Opcodes.AALOAD);
    mv.unbox(Type.getType("Ljava/lang/String;"));
    final int constructorCanonicalName = mv.newLocal(Type.getType("Ljava/lang/String;"));
    mv.storeLocal(constructorCanonicalName);

    new StringSwitch() {

        @Override
        void visitString() {
            mv.loadLocal(constructorCanonicalName);
        }

        @Override
        void visitCase(String canonicalName) {
            MethodNode methodNode = uniqueMethods.get(canonicalName);
            String owner = canonicalName.split("\\.")[0];

            // Parse method arguments and
            mv.visitVarInsn(Opcodes.ALOAD, 0);
            Type[] args = Type.getArgumentTypes(methodNode.desc);
            int argc = 0;
            for (Type t : args) {
                mv.visitVarInsn(Opcodes.ALOAD, 1);
                mv.push(argc + 1);
                mv.visitInsn(Opcodes.AALOAD);
                ByteCodeUtils.unbox(mv, t);
                argc++;
            }

            mv.visitMethodInsn(Opcodes.INVOKESPECIAL, owner, AsmUtils.CONSTRUCTOR,
                    methodNode.desc, false);

            mv.visitInsn(Opcodes.RETURN);
        }

        @Override
        void visitDefault() {
            writeMissingMessageWithHash(mv, visitedClassName);
        }
    }.visit(mv, uniqueMethods.keySet());

    mv.visitMaxs(1, 3);
    mv.visitEnd();
}
 

private static void generateRun(ClassVisitor cv, Type testType, int iThread, List<Actor> actors, List<Object> objArgs, boolean waitsEnabled) {
    int access = ACC_PUBLIC;
    Method m = new Method("call", RESULT_ARRAY_TYPE, NO_ARGS);
    GeneratorAdapter mv = new GeneratorAdapter(access, m,
        // Try-catch blocks sorting is required
        new TryCatchBlockSorter(cv.visitMethod(access, m.getName(), m.getDescriptor(), null, null),
            access, m.getName(), m.getDescriptor(), null, null)
    );
    mv.visitCode();
    // Create Result[] array and store it to a local variable
    int resLocal = createResultArray(mv, actors.size());
    // Call runner's onStart(iThread) method
    mv.loadThis();
    mv.getField(TEST_THREAD_EXECUTION_TYPE, "runner", RUNNER_TYPE);
    mv.push(iThread);
    mv.invokeVirtual(RUNNER_TYPE, RUNNER_ON_START_METHOD);
    // Number of current operation (starts with 0)
    int iLocal = mv.newLocal(Type.INT_TYPE);
    mv.push(0);
    mv.storeLocal(iLocal);
    // Invoke actors
    for (int i = 0; i < actors.size(); i++) {
        Actor actor = actors.get(i);
        // Add busy-wait before operation execution (for non-first operations only)
        if (waitsEnabled && i > 0) {
            mv.loadThis();
            mv.getField(TEST_THREAD_EXECUTION_TYPE, "waits", INT_ARRAY_TYPE);
            mv.push(i - 1);
            mv.arrayLoad(Type.INT_TYPE);
            mv.invokeStatic(UTILS_TYPE, UTILS_CONSUME_CPU);
        }
        // Start of try-catch block for exceptions which this actor should handle
        Label start, end = null, handler = null, handlerEnd = null;
        if (actor.handlesExceptions()) {
            start = mv.newLabel();
            end = mv.newLabel();
            handler = mv.newLabel();
            handlerEnd = mv.newLabel();
            for (Class<? extends Throwable> ec : actor.handledExceptions)
                mv.visitTryCatchBlock(start, end, handler, Type.getType(ec).getInternalName());
            mv.visitLabel(start);
        }
        // Load result array and index to store the current result
        mv.loadLocal(resLocal);
        mv.push(i);
        // Load test instance
        mv.loadThis();
        mv.getField(TEST_THREAD_EXECUTION_TYPE, "testInstance", OBJECT_TYPE);
        mv.checkCast(testType);
        // Load arguments for operation
        for (int j = 0; j < actor.arguments.length; j++) {
            pushArgumentOnStack(mv, objArgs, actor.arguments[j], actor.method.getParameterTypes()[j]);
        }
        // Invoke operation
        Method actorMethod = Method.getMethod(actor.method);
        mv.invokeVirtual(testType, actorMethod);
        // Create result
        mv.box(actorMethod.getReturnType()); // box if needed
        if (actor.method.getReturnType() == void.class) {
            mv.pop();
            mv.invokeStatic(RESULT_TYPE, RESULT_CREATE_VOID_RESULT);
        } else {
            mv.invokeStatic(RESULT_TYPE, RESULT_CREATE_VALUE_RESULT);
        }
        // Store result to array
        mv.arrayStore(RESULT_TYPE);
        // End of try-catch block
        if (actor.handlesExceptions()) {
            mv.visitLabel(end);
            mv.goTo(handlerEnd);
            mv.visitLabel(handler);
            storeExceptionResultFromThrowable(mv, resLocal, iLocal);
            mv.visitLabel(handlerEnd);
        }
        // Increment number of current operation
        mv.iinc(iLocal, 1);
    }
    // Call runner's onFinish(iThread) method
    mv.loadThis();
    mv.getField(TEST_THREAD_EXECUTION_TYPE, "runner", RUNNER_TYPE);
    mv.push(iThread);
    mv.invokeVirtual(RUNNER_TYPE, RUNNER_ON_FINISH_METHOD);
    // Return results
    mv.loadThis();
    mv.loadLocal(resLocal);
    mv.returnValue();
    mv.visitMaxs(1, 1);
    mv.visitEnd();
}
 

private static void defineMethod(ClassWriter cw, java.lang.reflect.Method method, Type proxyType)
{
    Type methodType = Type.getType(method);
    
    ArrayList<Type> exceptionsToCatch = new ArrayList<Type>();
    for (Class<?> exception : method.getExceptionTypes())
    {
        if (!RuntimeException.class.isAssignableFrom(exception))
        {
            exceptionsToCatch.add(Type.getType(exception));
        }
    }
    
    // push the method definition
    int modifiers = (Opcodes.ACC_PUBLIC | Opcodes.ACC_PROTECTED) & method.getModifiers();
    Method asmMethod = Method.getMethod(method);
    GeneratorAdapter mg = new GeneratorAdapter(modifiers,
            asmMethod,
            null,
            getTypes(method.getExceptionTypes()),
            cw);

    // copy annotations
    for (Annotation annotation : method.getDeclaredAnnotations())
    {
        mg.visitAnnotation(Type.getDescriptor(annotation.annotationType()), true).visitEnd();
    }

    mg.visitCode();

    Label tryBlockStart = mg.mark();

    mg.loadThis();
    mg.getField(proxyType, FIELDNAME_INVOCATION_HANDLER, TYPE_DELTA_SPIKE_PROXY_INVOCATION_HANDLER);
    mg.loadThis();
    loadCurrentMethod(mg, method, methodType);
    loadArguments(mg, method, methodType);
    
    mg.invokeVirtual(TYPE_DELTA_SPIKE_PROXY_INVOCATION_HANDLER,
            Method.getMethod("Object invoke(Object, java.lang.reflect.Method, Object[])"));

    // cast the result
    mg.unbox(methodType.getReturnType());

    // build try catch
    Label tryBlockEnd = mg.mark();
    
    // push return
    mg.returnValue();

    // catch runtime exceptions and rethrow it
    Label rethrow = mg.mark();
    mg.visitVarInsn(Opcodes.ASTORE, 1);
    mg.visitVarInsn(Opcodes.ALOAD, 1);
    mg.throwException();
    mg.visitTryCatchBlock(tryBlockStart, tryBlockEnd, rethrow, Type.getInternalName(RuntimeException.class));

    // catch checked exceptions and rethrow it
    boolean throwableCatched = false;
    if (!exceptionsToCatch.isEmpty())
    {
        rethrow = mg.mark();
        mg.visitVarInsn(Opcodes.ASTORE, 1);
        mg.visitVarInsn(Opcodes.ALOAD, 1);
        mg.throwException();

        // catch declared exceptions and rethrow it...
        for (Type exceptionType : exceptionsToCatch)
        {
            if (exceptionType.getClassName().equals(Throwable.class.getName()))
            {
                throwableCatched = true;
            }
            mg.visitTryCatchBlock(tryBlockStart, tryBlockEnd, rethrow, exceptionType.getInternalName());
        }
    }

    // if throwable isn't alreached cachted, catch it and wrap it with an UndeclaredThrowableException and throw it
    if (!throwableCatched)
    {
        Type uteType = Type.getType(UndeclaredThrowableException.class);
        Label wrapAndRethrow = mg.mark();

        mg.visitVarInsn(Opcodes.ASTORE, 1);
        mg.newInstance(uteType);
        mg.dup();
        mg.visitVarInsn(Opcodes.ALOAD, 1);
        mg.invokeConstructor(uteType,
                Method.getMethod("void <init>(java.lang.Throwable)"));
        mg.throwException();

        mg.visitTryCatchBlock(tryBlockStart, tryBlockEnd, wrapAndRethrow, Type.getInternalName(Throwable.class));
    }

    // finish the method
    mg.endMethod();
    mg.visitMaxs(12, 12);
    mg.visitEnd();
}