[-cxx-abi microsoft] Create backrefs for <unnamed-type-`id'>

It wasn't possible for an anonymous type to show up inside of function arguments.
However, decltype (which MSVC added support for in 2010) makes this
possible.  Further, backrefs to these anonymous types can now be formed.

This fixes PR18022.

N.B. We do not, and very likely _will not_, support MSVC's bug where
subsequent typedefs of anonymous types leak into the linkage name; this
is a gross violation of the ABI.  A warning should be introduced to
inform our users of this particular shortcoming.

llvm-svn: 195669

1 files changed, 16 insertions, 14 deletions

diff --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
index ed7168e3eb0..868bc11244a 100644
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -135,7 +135,7 @@ private:
     mangleUnqualifiedName(ND, ND->getDeclName());
   }
   void mangleUnqualifiedName(const NamedDecl *ND, DeclarationName Name);
-  void mangleSourceName(const IdentifierInfo *II);
+  void mangleSourceName(StringRef Name);
   void mangleOperatorName(OverloadedOperatorKind OO, SourceLocation Loc);
   void mangleCXXDtorType(CXXDtorType T);
   void mangleQualifiers(Qualifiers Quals, bool IsMember);
@@ -510,7 +510,7 @@ MicrosoftCXXNameMangler::mangleUnqualifiedName(const NamedDecl *ND,
   switch (Name.getNameKind()) {
     case DeclarationName::Identifier: {
       if (const IdentifierInfo *II = Name.getAsIdentifierInfo()) {
-        mangleSourceName(II);
+        mangleSourceName(II->getName());
         break;
       }
       
@@ -531,19 +531,22 @@ MicrosoftCXXNameMangler::mangleUnqualifiedName(const NamedDecl *ND,
                "Typedef should not be in another decl context!");
         assert(D->getDeclName().getAsIdentifierInfo() &&
                "Typedef was not named!");
-        mangleSourceName(D->getDeclName().getAsIdentifierInfo());
+        mangleSourceName(D->getDeclName().getAsIdentifierInfo()->getName());
         break;
       }
 
-      if (TD->hasDeclaratorForAnonDecl())
+      if (TD->hasDeclaratorForAnonDecl()) {
         // Anonymous types with no tag or typedef get the name of their
         // declarator mangled in.
-        Out << "<unnamed-type-" << TD->getDeclaratorForAnonDecl()->getName()
-            << ">@";
-      else
+        llvm::SmallString<64> Name("<unnamed-type-");
+        Name += TD->getDeclaratorForAnonDecl()->getName();
+        Name += ">";
+        mangleSourceName(Name.str());
+      } else {
         // Anonymous types with no tag, no typedef, or declarator get
-        // '<unnamed-tag>@'.
-        Out << "<unnamed-tag>@";
+        // '<unnamed-tag>'.
+        mangleSourceName("<unnamed-tag>");
+      }
       break;
     }
       
@@ -787,17 +790,16 @@ void MicrosoftCXXNameMangler::mangleOperatorName(OverloadedOperatorKind OO,
   }
 }
 
-void MicrosoftCXXNameMangler::mangleSourceName(const IdentifierInfo *II) {
+void MicrosoftCXXNameMangler::mangleSourceName(StringRef Name) {
   // <source name> ::= <identifier> @
-  std::string key = II->getNameStart();
   BackRefMap::iterator Found;
   if (UseNameBackReferences)
-    Found = NameBackReferences.find(key);
+    Found = NameBackReferences.find(Name);
   if (!UseNameBackReferences || Found == NameBackReferences.end()) {
-    Out << II->getName() << '@';
+    Out << Name << '@';
     if (UseNameBackReferences && NameBackReferences.size() < 10) {
       size_t Size = NameBackReferences.size();
-      NameBackReferences[key] = Size;
+      NameBackReferences[Name] = Size;
     }
   } else {
     Out << Found->second;