[MS ABI] Correctly mangle classes without names for linkage purposes

A class without a name for linkage purposes gets a name along the lines
of <unnamed-type-foo> where foo is either the name of a declarator which
defined it (like a variable or field) or a
typedef-name (like a typedef or alias-declaration).

We handled the declarator case correctly but it would fall down during
template instantiation if the declarator didn't share the tag's type.
We failed to handle the typedef-name case at all.

Instead, keep track of the association between the two and keep it up to
date in the face of template instantiation.

llvm-svn: 246469

1 files changed, 10 insertions, 3 deletions

diff --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
index 1be02f5e23c..596f1386570 100644
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -786,10 +786,17 @@ void MicrosoftCXXNameMangler::mangleUnqualifiedName(const NamedDecl *ND,
       }
 
       llvm::SmallString<64> Name("<unnamed-type-");
-      if (TD->hasDeclaratorForAnonDecl()) {
-        // Anonymous types with no tag or typedef get the name of their
+      if (DeclaratorDecl *DD =
+              Context.getASTContext().getDeclaratorForUnnamedTagDecl(TD)) {
+        // Anonymous types without a name for linkage purposes have their
         // declarator mangled in if they have one.
-        Name += TD->getDeclaratorForAnonDecl()->getName();
+        Name += DD->getName();
+      } else if (TypedefNameDecl *TND =
+                     Context.getASTContext().getTypedefNameForUnnamedTagDecl(
+                         TD)) {
+        // Anonymous types without a name for linkage purposes have their
+        // associate typedef mangled in if they have one.
+        Name += TND->getName();
       } else {
         // Otherwise, number the types using a $S prefix.
         Name += "$S";