[-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

2 files changed, 13 insertions, 7 deletions

diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 0fa1b980f31..dbbf4753dcc 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -3084,7 +3084,7 @@ TagDecl* TagDecl::getCanonicalDecl() {
 }
 
 void TagDecl::setTypedefNameForAnonDecl(TypedefNameDecl *TDD) {
-  TypedefNameDeclOrQualifier = TDD;
+  NamedDeclOrQualifier = TDD;
   if (TypeForDecl)
     assert(TypeForDecl->isLinkageValid());
   assert(isLinkageValid());
@@ -3141,7 +3141,7 @@ void TagDecl::setQualifierInfo(NestedNameSpecifierLoc QualifierLoc) {
   if (QualifierLoc) {
     // Make sure the extended qualifier info is allocated.
     if (!hasExtInfo())
-      TypedefNameDeclOrQualifier = new (getASTContext()) ExtInfo;
+      NamedDeclOrQualifier = new (getASTContext()) ExtInfo;
     // Set qualifier info.
     getExtInfo()->QualifierLoc = QualifierLoc;
   } else {
@@ -3149,7 +3149,7 @@ void TagDecl::setQualifierInfo(NestedNameSpecifierLoc QualifierLoc) {
     if (hasExtInfo()) {
       if (getExtInfo()->NumTemplParamLists == 0) {
         getASTContext().Deallocate(getExtInfo());
-        TypedefNameDeclOrQualifier = (TypedefNameDecl*) 0;
+        NamedDeclOrQualifier = (TypedefNameDecl*) 0;
       }
       else
         getExtInfo()->QualifierLoc = QualifierLoc;
@@ -3164,7 +3164,7 @@ void TagDecl::setTemplateParameterListsInfo(ASTContext &Context,
   // Make sure the extended decl info is allocated.
   if (!hasExtInfo())
     // Allocate external info struct.
-    TypedefNameDeclOrQualifier = new (getASTContext()) ExtInfo;
+    NamedDeclOrQualifier = new (getASTContext()) ExtInfo;
   // Set the template parameter lists info.
   getExtInfo()->setTemplateParameterListsInfo(Context, NumTPLists, TPLists);
 }
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;
     }