private void evaluateElvisOperatorExpression(ElvisOperatorExpression expression) {
MethodVisitor mv = controller.getMethodVisitor();
CompileStack compileStack = controller.getCompileStack();
OperandStack operandStack = controller.getOperandStack();
TypeChooser typeChooser = controller.getTypeChooser();
Expression boolPart = expression.getBooleanExpression().getExpression();
Expression falsePart = expression.getFalseExpression();
ClassNode truePartType = typeChooser.resolveType(boolPart, controller.getClassNode());
ClassNode falsePartType = typeChooser.resolveType(falsePart, controller.getClassNode());
ClassNode common = WideningCategories.lowestUpperBound(truePartType, falsePartType);
// x?:y is equal to x?x:y, which evals to
// var t=x; boolean(t)?t:y
// first we load x, dup it, convert the dupped to boolean, then
// jump depending on the value. For true we are done, for false we
// have to load y, thus we first remove x and then load y.
// But since x and y may have different stack lengths, this cannot work
// Thus we have to have to do the following:
// Be X the type of x, Y the type of y and S the common supertype of
// X and Y, then we have to see x?:y as
// var t=x;boolean(t)?S(t):S(y)
// so we load x, dup it, store the value in a local variable (t), then
// do boolean conversion. In the true part load t and cast it to S,
// in the false part load y and cast y to S
// load x, dup it, store one in $t and cast the remaining one to boolean
int mark = operandStack.getStackLength();
boolPart.visit(controller.getAcg());
operandStack.dup();
if (ClassHelper.isPrimitiveType(truePartType)
&& !ClassHelper.isPrimitiveType(operandStack.getTopOperand())) {
truePartType = ClassHelper.getWrapper(truePartType);
}
int retValueId = compileStack.defineTemporaryVariable("$t", truePartType, true);
operandStack.castToBool(mark, true);
Label l0 = operandStack.jump(IFEQ);
// true part: load $t and cast to S
operandStack.load(truePartType, retValueId);
operandStack.doGroovyCast(common);
Label l1 = new Label();
mv.visitJumpInsn(GOTO, l1);
// false part: load false expression and cast to S
mv.visitLabel(l0);
falsePart.visit(controller.getAcg());
operandStack.doGroovyCast(common);
// finish and cleanup
mv.visitLabel(l1);
compileStack.removeVar(retValueId);
controller.getOperandStack().replace(common, 2);
}
private void evaluateNormalTernary(TernaryExpression expression) {
MethodVisitor mv = controller.getMethodVisitor();
OperandStack operandStack = controller.getOperandStack();
TypeChooser typeChooser = controller.getTypeChooser();
Expression boolPart = expression.getBooleanExpression();
Expression truePart = expression.getTrueExpression();
Expression falsePart = expression.getFalseExpression();
ClassNode truePartType = typeChooser.resolveType(truePart, controller.getClassNode());
ClassNode falsePartType = typeChooser.resolveType(falsePart, controller.getClassNode());
ClassNode common = WideningCategories.lowestUpperBound(truePartType, falsePartType);
// we compile b?x:y as
// boolean(b)?S(x):S(y), S = common super type of x,y
// so we load b, do boolean conversion.
// In the true part load x and cast it to S,
// in the false part load y and cast y to S
// load b and convert to boolean
int mark = operandStack.getStackLength();
boolPart.visit(controller.getAcg());
operandStack.castToBool(mark, true);
Label l0 = operandStack.jump(IFEQ);
// true part: load x and cast to S
truePart.visit(controller.getAcg());
operandStack.doGroovyCast(common);
Label l1 = new Label();
mv.visitJumpInsn(GOTO, l1);
// false part: load y and cast to S
mv.visitLabel(l0);
falsePart.visit(controller.getAcg());
operandStack.doGroovyCast(common);
// finish and cleanup
mv.visitLabel(l1);
controller.getOperandStack().replace(common, 2);
}
public void evaluateEqual(BinaryExpression expression, boolean defineVariable) {
AsmClassGenerator acg = controller.getAcg();
CompileStack compileStack = controller.getCompileStack();
OperandStack operandStack = controller.getOperandStack();
Expression rightExpression = expression.getRightExpression();
Expression leftExpression = expression.getLeftExpression();
ClassNode lhsType =
controller.getTypeChooser().resolveType(leftExpression, controller.getClassNode());
if (defineVariable
&& rightExpression instanceof EmptyExpression
&& !(leftExpression instanceof TupleExpression)) {
VariableExpression ve = (VariableExpression) leftExpression;
BytecodeVariable var =
compileStack.defineVariable(
ve, controller.getTypeChooser().resolveType(ve, controller.getClassNode()), false);
operandStack.loadOrStoreVariable(var, false);
return;
}
// let's evaluate the RHS and store the result
ClassNode rhsType;
if (rightExpression instanceof ListExpression && lhsType.isArray()) {
ListExpression list = (ListExpression) rightExpression;
ArrayExpression array =
new ArrayExpression(lhsType.getComponentType(), list.getExpressions());
array.setSourcePosition(list);
array.visit(acg);
} else if (rightExpression instanceof EmptyExpression) {
rhsType = leftExpression.getType();
loadInitValue(rhsType);
} else {
rightExpression.visit(acg);
}
rhsType = operandStack.getTopOperand();
boolean directAssignment = defineVariable && !(leftExpression instanceof TupleExpression);
int rhsValueId;
if (directAssignment) {
VariableExpression var = (VariableExpression) leftExpression;
if (var.isClosureSharedVariable() && ClassHelper.isPrimitiveType(rhsType)) {
// GROOVY-5570: if a closure shared variable is a primitive type, it must be boxed
rhsType = ClassHelper.getWrapper(rhsType);
operandStack.box();
}
// ensure we try to unbox null to cause a runtime NPE in case we assign
// null to a primitive typed variable, even if it is used only in boxed
// form as it is closure shared
if (var.isClosureSharedVariable()
&& ClassHelper.isPrimitiveType(var.getOriginType())
&& isNull(rightExpression)) {
operandStack.doGroovyCast(var.getOriginType());
// these two are never reached in bytecode and only there
// to avoid verifyerrors and compiler infrastructure hazzle
operandStack.box();
operandStack.doGroovyCast(lhsType);
}
// normal type transformation
if (!ClassHelper.isPrimitiveType(lhsType) && isNull(rightExpression)) {
operandStack.replace(lhsType);
} else {
operandStack.doGroovyCast(lhsType);
}
rhsType = lhsType;
rhsValueId = compileStack.defineVariable(var, lhsType, true).getIndex();
} else {
rhsValueId = compileStack.defineTemporaryVariable("$rhs", rhsType, true);
}
// TODO: if rhs is VariableSlotLoader already, then skip crating a new one
BytecodeExpression rhsValueLoader = new VariableSlotLoader(rhsType, rhsValueId, operandStack);
// assignment for subscript
if (leftExpression instanceof BinaryExpression) {
BinaryExpression leftBinExpr = (BinaryExpression) leftExpression;
if (leftBinExpr.getOperation().getType() == Types.LEFT_SQUARE_BRACKET) {
assignToArray(
expression,
leftBinExpr.getLeftExpression(),
leftBinExpr.getRightExpression(),
rhsValueLoader);
}
compileStack.removeVar(rhsValueId);
return;
}
compileStack.pushLHS(true);
// multiple declaration
if (leftExpression instanceof TupleExpression) {
TupleExpression tuple = (TupleExpression) leftExpression;
int i = 0;
for (Expression e : tuple.getExpressions()) {
VariableExpression var = (VariableExpression) e;
MethodCallExpression call =
new MethodCallExpression(
rhsValueLoader, "getAt", new ArgumentListExpression(new ConstantExpression(i)));
call.visit(acg);
i++;
if (defineVariable) {
operandStack.doGroovyCast(var);
compileStack.defineVariable(var, true);
operandStack.remove(1);
} else {
acg.visitVariableExpression(var);
}
}
}
// single declaration
else if (defineVariable) {
rhsValueLoader.visit(acg);
operandStack.remove(1);
compileStack.popLHS();
return;
}
// normal assignment
else {
int mark = operandStack.getStackLength();
// to leave a copy of the rightExpression value on the stack after the assignment.
rhsValueLoader.visit(acg);
TypeChooser typeChooser = controller.getTypeChooser();
ClassNode targetType = typeChooser.resolveType(leftExpression, controller.getClassNode());
operandStack.doGroovyCast(targetType);
leftExpression.visit(acg);
operandStack.remove(operandStack.getStackLength() - mark);
}
compileStack.popLHS();
// return value of assignment
rhsValueLoader.visit(acg);
compileStack.removeVar(rhsValueId);
}