r250997 - [MS ABI] Mangle static anonymous unions

[David Majnemer via cfe-commits]

Author: majnemer
Date: Thu Oct 22 02:15:56 2015
New Revision: 250997

URL: http://llvm.org/viewvc/llvm-project?rev=250997&view=rev
Log:
[MS ABI] Mangle static anonymous unions

We believed that internal linkage variables at global scope which are
not variable template specializations did not have to be mangled.

However, static anonymous unions have no identifier and therefore must
be mangled.

This fixes PR18204.

Modified:
    cfe/trunk/lib/AST/MicrosoftCXXABI.cpp
    cfe/trunk/lib/AST/MicrosoftMangle.cpp
    cfe/trunk/test/CodeGenCXX/mangle-ms-cxx11.cpp

Modified: cfe/trunk/lib/AST/MicrosoftCXXABI.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/MicrosoftCXXABI.cpp?rev=250997&r1=250996&r2=250997&view=diff
==============================================================================
--- cfe/trunk/lib/AST/MicrosoftCXXABI.cpp (original)
+++ cfe/trunk/lib/AST/MicrosoftCXXABI.cpp Thu Oct 22 02:15:56 2015
@@ -89,17 +89,7 @@ public:
   }
 
   bool isNearlyEmpty(const CXXRecordDecl *RD) const override {
-    // FIXME: Audit the corners
-    if (!RD->isDynamicClass())
-      return false;
-
-    const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
-
-    // In the Microsoft ABI, classes can have one or two vtable pointers.
-    CharUnits PointerSize =
-        Context.toCharUnitsFromBits(Context.getTargetInfo().getPointerWidth(0));
-    return Layout.getNonVirtualSize() == PointerSize ||
-      Layout.getNonVirtualSize() == PointerSize * 2;
+    llvm_unreachable("unapplicable to the MS ABI");
   }
 
   void addDefaultArgExprForConstructor(const CXXConstructorDecl *CD,

Modified: cfe/trunk/lib/AST/MicrosoftMangle.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/MicrosoftMangle.cpp?rev=250997&r1=250996&r2=250997&view=diff
==============================================================================
--- cfe/trunk/lib/AST/MicrosoftMangle.cpp (original)
+++ cfe/trunk/lib/AST/MicrosoftMangle.cpp Thu Oct 22 02:15:56 2015
@@ -365,7 +365,8 @@ bool MicrosoftMangleContextImpl::shouldM
         DC = getEffectiveParentContext(DC);
 
     if (DC->isTranslationUnit() && D->getFormalLinkage() == InternalLinkage &&
-        !isa<VarTemplateSpecializationDecl>(D))
+        !isa<VarTemplateSpecializationDecl>(D) &&
+        D->getIdentifier() != nullptr)
       return false;
   }
 
@@ -801,7 +802,7 @@ void MicrosoftCXXNameMangler::mangleUnqu
       } else {
         // Otherwise, number the types using a $S prefix.
         Name += "$S";
-        Name += llvm::utostr(Context.getAnonymousStructId(TD));
+        Name += llvm::utostr(Context.getAnonymousStructId(TD) + 1);
       }
       Name += ">";
       mangleSourceName(Name.str());

Modified: cfe/trunk/test/CodeGenCXX/mangle-ms-cxx11.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/mangle-ms-cxx11.cpp?rev=250997&r1=250996&r2=250997&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/mangle-ms-cxx11.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/mangle-ms-cxx11.cpp Thu Oct 22 02:15:56 2015
@@ -277,3 +277,12 @@ void g() {
 // CHECK-DAG: @"\01??$f at W4<unnamed-type-E>@?1??g at PR24651@@YAXXZ@@PR24651@@YAXW4<unnamed-type-E>@?1??g at 0@YAXXZ@@Z"
 // CHECK-DAG: @"\01??$f at W4<unnamed-type-E>@?2??g at PR24651@@YAXXZ@@PR24651@@YAXW4<unnamed-type-E>@?2??g at 0@YAXXZ@@Z"
 }
+
+namespace PR18204 {
+template <typename T>
+int f(T *);
+static union {
+  int n = f(this);
+};
+// CHECK-DAG: @"\01??$f at T<unnamed-type-$S1>@PR18204@@@PR18204@@YAHPAT<unnamed-type-$S1>@0@@Z"
+}