Examples with BytecodeExpression org.codehaus.groovy.classgen.BytecodeExpression used on opensource projects

Example 16 with BytecodeExpression

use of org.codehaus.groovy.classgen.BytecodeExpression in project groovy by apache.

the class BinaryExpressionHelper method writePostOrPrefixMethod.

protected void writePostOrPrefixMethod(int op, String method, Expression expression, Expression orig) {
    final OperandStack operandStack = controller.getOperandStack();
    // at this point the receiver will be already on the stack.
    // in a[1]++ the method will be "++" aka "next" and the receiver a[1]
    ClassNode BEType = controller.getTypeChooser().resolveType(expression, controller.getClassNode());
    Expression callSiteReceiverSwap = new BytecodeExpression(BEType) {

        @Override
        public void visit(MethodVisitor mv) {
            // CallSite is normally not showing up on the 
            // operandStack, so we place a dummy here with same
            // slot length.
            operandStack.push(ClassHelper.OBJECT_TYPE);
            // change (receiver,callsite) to (callsite,receiver)
            operandStack.swap();
            setType(operandStack.getTopOperand());
            // no need to keep any of those on the operand stack
            // after this expression is processed, the operand stack
            // will contain callSiteReceiverSwap.getType()
            operandStack.remove(2);
        }
    };
    // execute method
    // this will load the callsite and the receiver normally in the wrong
    // order since the receiver is already present, but before the callsite
    // Therefore we use callSiteReceiverSwap to correct the order. 
    // After this call the JVM operand stack will contain the the result of
    // the method call... usually simply Object in operandStack
    controller.getCallSiteWriter().makeCallSite(callSiteReceiverSwap, method, MethodCallExpression.NO_ARGUMENTS, false, false, false, false);
// now rhs is completely done and we need only to store. In a[1]++ this 
// would be a.getAt(1).next() for the rhs, "lhs" code is a.putAt(1, rhs)
}