Track in the AST whether the operand to a UnaryOperator can overflow and then use that logic when evaluating constant expressions and emitting codegen.
llvm-svn: 322074
diff --git a/clang/lib/Sema/SemaPseudoObject.cpp b/clang/lib/Sema/SemaPseudoObject.cpp
index 58980be..f09a6f7 100644
--- a/clang/lib/Sema/SemaPseudoObject.cpp
+++ b/clang/lib/Sema/SemaPseudoObject.cpp
@@ -132,7 +132,8 @@
uop->getType(),
uop->getValueKind(),
uop->getObjectKind(),
- uop->getOperatorLoc());
+ uop->getOperatorLoc(),
+ uop->canOverflow());
}
if (GenericSelectionExpr *gse = dyn_cast<GenericSelectionExpr>(e)) {
@@ -524,15 +525,18 @@
addSemanticExpr(result.get());
if (UnaryOperator::isPrefix(opcode) && !captureSetValueAsResult() &&
!result.get()->getType()->isVoidType() &&
- (result.get()->isTypeDependent() || CanCaptureValue(result.get())))
- setResultToLastSemantic();
-
- UnaryOperator *syntactic =
- new (S.Context) UnaryOperator(syntacticOp, opcode, resultType,
- VK_LValue, OK_Ordinary, opcLoc);
- return complete(syntactic);
-}
-
+ (result.get()->isTypeDependent() || CanCaptureValue(result.get())))
+ setResultToLastSemantic();
+
+ UnaryOperator *syntactic = new (S.Context) UnaryOperator(
+ syntacticOp, opcode, resultType, VK_LValue, OK_Ordinary, opcLoc,
+ !resultType->isDependentType()
+ ? S.Context.getTypeSize(resultType) >=
+ S.Context.getTypeSize(S.Context.IntTy)
+ : false);
+ return complete(syntactic);
+}
+
//===----------------------------------------------------------------------===//
// Objective-C @property and implicit property references
@@ -1550,7 +1554,7 @@
// Do nothing if the operand is dependent.
if (op->isTypeDependent())
return new (Context) UnaryOperator(op, opcode, Context.DependentTy,
- VK_RValue, OK_Ordinary, opcLoc);
+ VK_RValue, OK_Ordinary, opcLoc, false);
assert(UnaryOperator::isIncrementDecrementOp(opcode));
Expr *opaqueRef = op->IgnoreParens();
@@ -1630,15 +1634,15 @@
/// capable of rebuilding a tree without stripping implicit
/// operations.
Expr *Sema::recreateSyntacticForm(PseudoObjectExpr *E) {
- Expr *syntax = E->getSyntacticForm();
- if (UnaryOperator *uop = dyn_cast<UnaryOperator>(syntax)) {
- Expr *op = stripOpaqueValuesFromPseudoObjectRef(*this, uop->getSubExpr());
- return new (Context) UnaryOperator(op, uop->getOpcode(), uop->getType(),
- uop->getValueKind(), uop->getObjectKind(),
- uop->getOperatorLoc());
- } else if (CompoundAssignOperator *cop
- = dyn_cast<CompoundAssignOperator>(syntax)) {
- Expr *lhs = stripOpaqueValuesFromPseudoObjectRef(*this, cop->getLHS());
+ Expr *syntax = E->getSyntacticForm();
+ if (UnaryOperator *uop = dyn_cast<UnaryOperator>(syntax)) {
+ Expr *op = stripOpaqueValuesFromPseudoObjectRef(*this, uop->getSubExpr());
+ return new (Context) UnaryOperator(
+ op, uop->getOpcode(), uop->getType(), uop->getValueKind(),
+ uop->getObjectKind(), uop->getOperatorLoc(), uop->canOverflow());
+ } else if (CompoundAssignOperator *cop
+ = dyn_cast<CompoundAssignOperator>(syntax)) {
+ Expr *lhs = stripOpaqueValuesFromPseudoObjectRef(*this, cop->getLHS());
Expr *rhs = cast<OpaqueValueExpr>(cop->getRHS())->getSourceExpr();
return new (Context) CompoundAssignOperator(lhs, rhs, cop->getOpcode(),
cop->getType(),