Updated checker for "return of address of stack variable" to look for

implicit casts from T to T& at the topmost part of the return-value expression.

This checking may be needed within EvalAddr later on.  We'll wait until
test cases show this kind of logic is necessary (as more C++ features are
implemented in clang).

llvm-svn: 41493

1 files changed, 6 insertions, 4 deletions

diff --git a/clang/Sema/SemaChecking.cpp b/clang/Sema/SemaChecking.cpp
index e03507b7968..c027fa794c9 100644
--- a/clang/Sema/SemaChecking.cpp
+++ b/clang/Sema/SemaChecking.cpp
@@ -410,10 +410,12 @@ Sema::CheckReturnStackAddr(Expr *RetValExp, QualType lhsType,
   }
   // Perform checking for stack values returned by reference.
   else if (lhsType->isReferenceType()) {
-    if (DeclRefExpr *DR = EvalVal(RetValExp))
-      Diag(DR->getLocStart(), diag::warn_ret_stack_ref,
-           DR->getDecl()->getIdentifier()->getName(),
-           RetValExp->getSourceRange());
+    // Check for an implicit cast to a reference.
+    if (ImplicitCastExpr *I = dyn_cast<ImplicitCastExpr>(RetValExp))
+      if (DeclRefExpr *DR = EvalVal(I->getSubExpr()))
+        Diag(DR->getLocStart(), diag::warn_ret_stack_ref,
+             DR->getDecl()->getIdentifier()->getName(),
+             RetValExp->getSourceRange());
   }
 }