Teach SemaChecking::CheckReturnStackAddr about ImplicitCastExprs that convert values to an lvalue. This allows us to warn (again) about returning references to stack variables. (fixes PR 7812).
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@110242 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index d17ea43..0fcc0a7 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -1952,7 +1952,7 @@
/// EvalVal - This function is complements EvalAddr in the mutual recursion.
/// See the comments for EvalAddr for more details.
static DeclRefExpr* EvalVal(Expr *E) {
-
+do {
// We should only be called for evaluating non-pointer expressions, or
// expressions with a pointer type that are not used as references but instead
// are l-values (e.g., DeclRefExpr with a pointer type).
@@ -1961,6 +1961,15 @@
// viewed AST node. We then recursively traverse the AST by calling
// EvalAddr and EvalVal appropriately.
switch (E->getStmtClass()) {
+ case Stmt::ImplicitCastExprClass: {
+ ImplicitCastExpr *IE = cast<ImplicitCastExpr>(E);
+ if (IE->getCategory() == ImplicitCastExpr::LValue) {
+ E = IE->getSubExpr();
+ continue;
+ }
+ return NULL;
+ }
+
case Stmt::DeclRefExprClass: {
// DeclRefExpr: the base case. When we hit a DeclRefExpr we are looking
// at code that refers to a variable's name. We check if it has local
@@ -1973,9 +1982,11 @@
return NULL;
}
- case Stmt::ParenExprClass:
+ case Stmt::ParenExprClass: {
// Ignore parentheses.
- return EvalVal(cast<ParenExpr>(E)->getSubExpr());
+ E = cast<ParenExpr>(E)->getSubExpr();
+ continue;
+ }
case Stmt::UnaryOperatorClass: {
// The only unary operator that make sense to handle here
@@ -2024,6 +2035,7 @@
default:
return NULL;
}
+} while (true);
}
//===--- CHECK: Floating-Point comparisons (-Wfloat-equal) ---------------===//