From: Eli Friedman <eli.friedman@gmail.com>
Date: Fri, 5 Jul 2013 20:27:40 +0000 (+0000)
Subject: Don't use mangleCXXRTTIName in TBAA for C code.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=1847c718fe61f8e99d77c60ab77c9bf2ad4d77aa;p=clang

Don't use mangleCXXRTTIName in TBAA for C code.

This changes the TBAA code so it doesn't use mangleCXXRTTIName in C,
because it doesn't really make sense there.  Also, as sort of a
defense-in-depth change, fix the mangler so it handles C RecordDecls
correctly.

No tests because I don't know the TBAA code well enough to write a test,
and I don't know how else to trigger mangling a local struct in C.

Fixes a crash with r185450 reported by Joerg Sonnenberger.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185721 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/AST/ItaniumMangle.cpp b/lib/AST/ItaniumMangle.cpp
index adfc3a790f..79219825aa 100644
--- a/lib/AST/ItaniumMangle.cpp
+++ b/lib/AST/ItaniumMangle.cpp
@@ -72,11 +72,11 @@ static bool isLocalContainerContext(const DeclContext *DC) {
   return isa<FunctionDecl>(DC) || isa<ObjCMethodDecl>(DC) || isa<BlockDecl>(DC);
 }
 
-static const CXXRecordDecl *GetLocalClassDecl(const Decl *D) {
+static const RecordDecl *GetLocalClassDecl(const Decl *D) {
   const DeclContext *DC = getEffectiveDeclContext(D);
   while (!DC->isNamespace() && !DC->isTranslationUnit()) {
     if (isLocalContainerContext(DC))
-      return dyn_cast<CXXRecordDecl>(D);
+      return dyn_cast<RecordDecl>(D);
     D = cast<Decl>(DC);
     DC = getEffectiveDeclContext(D);
   }
@@ -1280,7 +1280,7 @@ void CXXNameMangler::mangleLocalName(const Decl *D) {
   //                 _ <entity name>
   // <discriminator> := _ <non-negative number>
   assert(isa<NamedDecl>(D) || isa<BlockDecl>(D));
-  const CXXRecordDecl *RD = GetLocalClassDecl(D);
+  const RecordDecl *RD = GetLocalClassDecl(D);
   const DeclContext *DC = getEffectiveDeclContext(RD ? RD : D);
 
   Out << 'Z';
@@ -1301,9 +1301,10 @@ void CXXNameMangler::mangleLocalName(const Decl *D) {
     // numbering will be local to the particular argument in which it appears
     // -- other default arguments do not affect its encoding.
     bool SkipDiscriminator = false;
-    if (RD->isLambda()) {
+    const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD);
+    if (CXXRD->isLambda()) {
       if (const ParmVarDecl *Parm
-                 = dyn_cast_or_null<ParmVarDecl>(RD->getLambdaContextDecl())) {
+              = dyn_cast_or_null<ParmVarDecl>(CXXRD->getLambdaContextDecl())) {
         if (const FunctionDecl *Func
               = dyn_cast<FunctionDecl>(Parm->getDeclContext())) {
           Out << 'd';
diff --git a/lib/CodeGen/CodeGenTBAA.cpp b/lib/CodeGen/CodeGenTBAA.cpp
index f299481ffe..0a8c293cb7 100644
--- a/lib/CodeGen/CodeGenTBAA.cpp
+++ b/lib/CodeGen/CodeGenTBAA.cpp
@@ -150,19 +150,11 @@ CodeGenTBAA::getTBAAInfo(QualType QTy) {
   // Enum types are distinct types. In C++ they have "underlying types",
   // however they aren't related for TBAA.
   if (const EnumType *ETy = dyn_cast<EnumType>(Ty)) {
-    // In C mode, two anonymous enums are compatible iff their members
-    // are the same -- see C99 6.2.7p1. For now, be conservative. We could
-    // theoretically implement this by combining information about all the
-    // members into a single identifying MDNode.
-    if (!Features.CPlusPlus &&
-        ETy->getDecl()->getTypedefNameForAnonDecl())
-      return MetadataCache[Ty] = getChar();
-
     // In C++ mode, types have linkage, so we can rely on the ODR and
     // on their mangled names, if they're external.
     // TODO: Is there a way to get a program-wide unique name for a
     // decl with local linkage or no linkage?
-    if (Features.CPlusPlus && !ETy->getDecl()->isExternallyVisible())
+    if (!Features.CPlusPlus || !ETy->getDecl()->isExternallyVisible())
       return MetadataCache[Ty] = getChar();
 
     // TODO: This is using the RTTI name. Is there a better way to get