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

1 files changed, 8 insertions, 6 deletions

diff --git a/clang/lib/AST/ASTDumper.cpp b/clang/lib/AST/ASTDumper.cpp
index 22b71e3cf53..e553ba7e7a3 100644
--- a/clang/lib/AST/ASTDumper.cpp
+++ b/clang/lib/AST/ASTDumper.cpp
@@ -2214,12 +2214,14 @@ void ASTDumper::VisitArrayInitIndexExpr(const ArrayInitIndexExpr *E) {
 }
 
 void ASTDumper::VisitUnaryOperator(const UnaryOperator *Node) {
-  VisitExpr(Node);
-  OS << " " << (Node->isPostfix() ? "postfix" : "prefix")
-     << " '" << UnaryOperator::getOpcodeStr(Node->getOpcode()) << "'";
-}
-
-void ASTDumper::VisitUnaryExprOrTypeTraitExpr(
+  VisitExpr(Node);

+  OS << " " << (Node->isPostfix() ? "postfix" : "prefix")

+     << " '" << UnaryOperator::getOpcodeStr(Node->getOpcode()) << "'";

+  if (!Node->canOverflow())

+    OS << " cannot overflow";

+}

+

+void ASTDumper::VisitUnaryExprOrTypeTraitExpr(

     const UnaryExprOrTypeTraitExpr *Node) {
   VisitExpr(Node);
   switch(Node->getKind()) {