[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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@250997 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/AST/MicrosoftCXXABI.cpp b/lib/AST/MicrosoftCXXABI.cpp
index ff84fa5c22526554853c99c7059d9fc79a1df364..6ba31ccf1e37649c2ed79c5eb05a8e37599fd51c 100644 (file)
--- a/lib/AST/MicrosoftCXXABI.cpp
+++ b/lib/AST/MicrosoftCXXABI.cpp
@@ -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,

diff --git a/lib/AST/MicrosoftMangle.cpp b/lib/AST/MicrosoftMangle.cpp
index c4baed21cb432b3fd98263e5828160e8cf6a7383..5c30ae28b34a7398dbe31733fdabaee77b16723f 100644 (file)
--- a/lib/AST/MicrosoftMangle.cpp
+++ b/lib/AST/MicrosoftMangle.cpp
@@ -365,7 +365,8 @@ bool MicrosoftMangleContextImpl::shouldMangleCXXName(const NamedDecl *D) {
         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::mangleUnqualifiedName(const NamedDecl *ND,
       } 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());

diff --git a/test/CodeGenCXX/mangle-ms-cxx11.cpp b/test/CodeGenCXX/mangle-ms-cxx11.cpp
index 0a4c602df62bfec7ae9bc984f24c6eb7e9d2a366..999def87fc5eadc3271dce8a9b5f80f95ad95bf8 100644 (file)
--- a/test/CodeGenCXX/mangle-ms-cxx11.cpp
+++ b/test/CodeGenCXX/mangle-ms-cxx11.cpp
@@ -277,3 +277,12 @@ void g() {
 // CHECK-DAG: @"\01??$f@W4<unnamed-type-E>@?1??g@PR24651@@YAXXZ@@PR24651@@YAXW4<unnamed-type-E>@?1??g@0@YAXXZ@@Z"
 // CHECK-DAG: @"\01??$f@W4<unnamed-type-E>@?2??g@PR24651@@YAXXZ@@PR24651@@YAXW4<unnamed-type-E>@?2??g@0@YAXXZ@@Z"
 }
+
+namespace PR18204 {
+template <typename T>
+int f(T *);
+static union {
+  int n = f(this);
+};
+// CHECK-DAG: @"\01??$f@T<unnamed-type-$S1>@PR18204@@@PR18204@@YAHPAT<unnamed-type-$S1>@0@@Z"
+}