Use Expr::Evaluate for case statements. Fixes PR2525
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@59881 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index 6b71d11..35cec0f 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -537,19 +537,28 @@
// These need to be handled specially because the operands aren't
// necessarily integral
bool bres;
- if (!HandleConversionToBool(E->getLHS(), bres, Info)) {
+
+ if (HandleConversionToBool(E->getLHS(), bres, Info)) {
+ // We were able to evaluate the LHS, see if we can get away with not
+ // evaluating the RHS: 0 && X -> 0, 1 || X -> 1
+ } else {
// We can't evaluate the LHS; however, sometimes the result
// is determined by the RHS: X && 0 -> 0, X || 1 -> 1.
- if (HandleConversionToBool(E->getRHS(), bres, Info) &&
- bres == (E->getOpcode() == BinaryOperator::LOr)) {
- Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
- Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
- Result = bres;
- return true;
+ if (!HandleConversionToBool(E->getRHS(), bres, Info)) {
+ // We can't evaluate.
+ return false;
}
+ }
- // Really can't evaluate
- return false;
+ // FIXME: If we evaluate the RHS, we need to check if the LHS has
+ // any side effects.
+
+ if (bres == (E->getOpcode() == BinaryOperator::LOr) ||
+ !bres == (E->getOpcode() == BinaryOperator::LAnd)) {
+ Result.zextOrTrunc(getIntTypeSizeInBits(E->getType()));
+ Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
+ Result = bres;
+ return true;
}
bool bres2;
@@ -1176,3 +1185,12 @@
APValue V;
return Evaluate(V, Ctx);
}
+
+APSInt Expr::EvaluateAsInt(ASTContext &Ctx) const {
+ APValue V;
+ bool Result = Evaluate(V, Ctx);
+ assert(Result && "Could not evaluate expression");
+ assert(V.isInt() && "Expression did not evaluate to integer");
+
+ return V.getInt();
+}