Java GeneratorAdapter.newLocal方法代碼示例

import org.objectweb.asm.commons.GeneratorAdapter; //導入方法依賴的package包/類
LockTransformer(GeneratorAdapter mv, List<MethodInstructionPredicate> lockPredicates,
    List<MethodInstructionPredicate> tryLockPredicates, List<MethodInstructionPredicate> unlockPredicates,
    String className, String methodName, String fileName)
{
    super(mv, className, methodName, fileName);
    this.lockPredicates = lockPredicates;
    this.tryLockPredicates = tryLockPredicates;
    this.unlockPredicates = unlockPredicates;
    lockLocal = mv.newLocal(OBJECT_TYPE);
}
 

import org.objectweb.asm.commons.GeneratorAdapter; //導入方法依賴的package包/類
@Override
protected void createLocals(GeneratorAdapter mv, List<Type> args) {
    super.createLocals(mv, args);

    // Override the locals creation to keep a reference to it. We keep a reference to this
    // array because we use it to receive the values of the local variables after the
    // redirection is done.
    locals = mv.newLocal(Type.getType("[Ljava/lang/Object;"));
    mv.dup();
    mv.storeLocal(locals);
}
 

import org.objectweb.asm.commons.GeneratorAdapter; //導入方法依賴的package包/類
@Override
protected void restore(GeneratorAdapter mv, List<Type> args) {
    // At this point, init$args has been called and the result Object is on the stack.
    // The value of that Object is Object[] with exactly n + 1 elements.
    // The first element is a string with the qualified name of the constructor to call.
    // The remaining elements are the constructtor arguments.

    // Create a new local that holds the result of init$args call.
    mv.visitTypeInsn(Opcodes.CHECKCAST, "[Ljava/lang/Object;");
    int constructorArgs = mv.newLocal(Type.getType("[Ljava/lang/Object;"));
    mv.storeLocal(constructorArgs);

    // Reinstate local values
    mv.loadLocal(locals);
    int stackIndex = 0;
    for (int arrayIndex = 0; arrayIndex < args.size(); arrayIndex++) {
        Type arg = args.get(arrayIndex);
        // Do not restore "this"
        if (arrayIndex > 0) {
            // duplicates the array
            mv.dup();
            // index in the array of objects to restore the boxed parameter.
            mv.push(arrayIndex);
            // get it from the array
            mv.arrayLoad(Type.getType(Object.class));
            // unbox the argument
            ByteCodeUtils.unbox(mv, arg);
            // restore the argument
            mv.visitVarInsn(arg.getOpcode(Opcodes.ISTORE), stackIndex);
        }
        // stack index must progress according to the parameter type we just processed.
        stackIndex += arg.getSize();
    }
    // pops the array
    mv.pop();

    // Push a null for the marker parameter.
    mv.loadLocal(constructorArgs);
    mv.visitInsn(Opcodes.ACONST_NULL);

    // Invoke the constructor
    mv.visitMethodInsn(Opcodes.INVOKESPECIAL, thisClassName, "<init>", DISPATCHING_THIS_SIGNATURE, false);

    mv.goTo(end.getLabel());
}