[-cxx-abi microsoft] Mangle local TagDecls appropriately

Summary:
When selecting a mangling for an anonymous tag type:
- We should first try it's typedef'd name.
- If that doesn't work, we should mangle in the name of the declarator
  that specified it as a declaration specifier.
- If that doesn't work, fall back to a static mangling of
  <unnamed-type>.

This should make our anonymous type mangling compatible.

This partially fixes PR16994; we would need to have an implementation of
scope numbering to get it right (a separate issue).

Reviewers: rnk, rsmith, rjmccall, cdavis5x

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1540

llvm-svn: 190892

1 files changed, 9 insertions, 3 deletions

diff --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
index 8506c4c8dde..119bc86be29 100644
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -563,9 +563,15 @@ MicrosoftCXXNameMangler::mangleUnqualifiedName(const NamedDecl *ND,
         break;
       }
 
-      // When VC encounters an anonymous type with no tag and no typedef,
-      // it literally emits '<unnamed-tag>@'.
-      Out << "<unnamed-tag>@";
+      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
+        // Anonymous types with no tag, no typedef, or declarator get
+        // '<unnamed-tag>@'.
+        Out << "<unnamed-tag>@";
       break;
     }