From: Argyrios Kyrtzidis <akyrtzi@gmail.com>
Date: Mon, 29 Nov 2010 23:42:03 +0000 (+0000)
Subject: Revert r120331 since it causes spurious warnings and a possible assertion hit when... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d976ca4fcacdd965446bcfbe8cb03b4ee67cd827;p=clang

Revert r120331 since it causes spurious warnings and a possible assertion hit when self-host.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@120351 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 9404c6861d..fd049e37d9 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -3230,12 +3230,6 @@ def warn_ret_stack_addr : Warning<
   "address of stack memory associated with local variable %0 returned">;
 def warn_ret_stack_ref : Warning<
   "reference to stack memory associated with local variable %0 returned">;
-def warn_ret_local_temp_ref : Warning<
-  "returning reference to local temporary">;
-def warn_ret_local_temp_var_ref : Warning<
-  "reference to temporary associated with local variable %0 returned">;
-def note_local_temp_var_ref : Note<
-  "binding variable %0 to temporary here">;
 def warn_ret_addr_label : Warning<
   "returning address of label, which is local">;
 def err_ret_local_block : Error<
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 807a550750..ed45de53f2 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -1787,35 +1787,11 @@ Sema::CheckReturnStackAddr(Expr *RetValExp, QualType lhsType,
         << ALE->getSourceRange();
 
   } else if (lhsType->isReferenceType()) {
-    // Perform checking for local temporaries returned by reference.
-    if (RetValExp->Classify(Context).isPRValue()) {
-      Diag(RetValExp->getLocStart(), diag::warn_ret_local_temp_ref)
-        << RetValExp->getSourceRange();
-      return;
-    }
-
     // Perform checking for stack values returned by reference.
     // Check for a reference to the stack
-    if (DeclRefExpr *DR = EvalVal(RetValExp)) {
-      const VarDecl *VD = cast<VarDecl>(DR->getDecl());
-      // Check for returning reference variable that binds to temporary.
-      if (VD->getType()->isReferenceType()) {
-        if (const Expr *init = VD->getInit())
-          if (init->Classify(Context).isPRValue()) {
-            Diag(DR->getLocStart(), diag::warn_ret_local_temp_var_ref)
-              << VD->getDeclName() << RetValExp->getSourceRange();
-            Diag(VD->getLocation(), diag::note_local_temp_var_ref)
-              << VD->getDeclName() << VD->getInit()->getSourceRange();
-          }
-
-        // When returning a reference variable that doesn't bind to temporary,
-        // no warning.
-        return;
-      }
-
+    if (DeclRefExpr *DR = EvalVal(RetValExp))
       Diag(DR->getLocStart(), diag::warn_ret_stack_ref)
-        << VD->getDeclName() << RetValExp->getSourceRange();
-    }
+        << DR->getDecl()->getDeclName() << RetValExp->getSourceRange();
   }
 }
 
@@ -1977,7 +1953,7 @@ do {
     DeclRefExpr *DR = cast<DeclRefExpr>(E);
 
     if (VarDecl *V = dyn_cast<VarDecl>(DR->getDecl()))
-      if (V->hasLocalStorage()) return DR;
+      if (V->hasLocalStorage() && !V->getType()->isReferenceType()) return DR;
 
     return NULL;
   }
diff --git a/test/Analysis/stack-addr-ps.cpp b/test/Analysis/stack-addr-ps.cpp
index 8ecb6a67ea..593ba1df94 100644
--- a/test/Analysis/stack-addr-ps.cpp
+++ b/test/Analysis/stack-addr-ps.cpp
@@ -6,12 +6,3 @@ const int& g() {
   int s;
   return s; // expected-warning{{reference to stack memory associated with local variable 's' returned}}
 }
-
-int get_value();
-
-const int &get_reference1() { return get_value(); } // expected-warning {{returning reference to local temporary}}
-
-const int &get_reference2() {
-  int const& w2 = get_value(); // expected-note {{binding variable 'w2' to temporary here}}
-  return w2; // expected-warning {{reference to temporary associated with local variable 'w2' returned}}
-}
diff --git a/test/SemaCXX/rval-references.cpp b/test/SemaCXX/rval-references.cpp
index 2068642c9d..30622ccbfe 100644
--- a/test/SemaCXX/rval-references.cpp
+++ b/test/SemaCXX/rval-references.cpp
@@ -6,7 +6,7 @@ typedef int& ilr;
 typedef ilr&& ilr_c2; // Collapses to int&
 
 irr ret_irr() {
-  return 0; // expected-warning {{returning reference to local temporary}}
+  return 0;
 }
 
 struct not_int {};