r210416 - MS ABI: Simplify microsoft mangling of template instantiations

[David Majnemer]

Author: majnemer
Date: Sat Jun  7 23:51:13 2014
New Revision: 210416

URL: http://llvm.org/viewvc/llvm-project?rev=210416&view=rev
Log:
MS ABI: Simplify microsoft mangling of template instantiations

Use mangled template instantiation name as key for back references.
Templates have their own context for back references, so their mangling
is always the same regardless of context. This avoids mangling template
instantiations twice.

Patch by Agustín Bergé!

Modified:
    cfe/trunk/lib/AST/MicrosoftMangle.cpp

Modified: cfe/trunk/lib/AST/MicrosoftMangle.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/MicrosoftMangle.cpp?rev=210416&r1=210415&r2=210416&view=diff
==============================================================================
--- cfe/trunk/lib/AST/MicrosoftMangle.cpp (original)
+++ cfe/trunk/lib/AST/MicrosoftMangle.cpp Sat Jun  7 23:51:13 2014
@@ -193,7 +193,6 @@ class MicrosoftCXXNameMangler {
 
   typedef llvm::StringMap<unsigned> BackRefMap;
   BackRefMap NameBackReferences;
-  bool UseNameBackReferences;
 
   typedef llvm::DenseMap<void *, unsigned> ArgBackRefMap;
   ArgBackRefMap TypeBackReferences;
@@ -209,14 +208,12 @@ public:
 
   MicrosoftCXXNameMangler(MicrosoftMangleContextImpl &C, raw_ostream &Out_)
       : Context(C), Out(Out_), Structor(nullptr), StructorType(-1),
-        UseNameBackReferences(true),
         PointersAre64Bit(C.getASTContext().getTargetInfo().getPointerWidth(0) ==
                          64) {}
 
   MicrosoftCXXNameMangler(MicrosoftMangleContextImpl &C, raw_ostream &Out_,
                           const CXXDestructorDecl *D, CXXDtorType Type)
       : Context(C), Out(Out_), Structor(getStructor(D)), StructorType(Type),
-        UseNameBackReferences(true),
         PointersAre64Bit(C.getASTContext().getTargetInfo().getPointerWidth(0) ==
                          64) {}
 
@@ -241,7 +238,6 @@ public:
   void mangleNestedName(const NamedDecl *ND);
 
 private:
-  void disableBackReferences() { UseNameBackReferences = false; }
   void mangleUnqualifiedName(const NamedDecl *ND) {
     mangleUnqualifiedName(ND, ND->getDeclName());
   }
@@ -667,26 +663,22 @@ void MicrosoftCXXNameMangler::mangleUnqu
     //   type [ -> template-parameters]
     //      \-> namespace[s]
     // What we do is we create a new mangler, mangle the same type (without
-    // a namespace suffix) using the extra mangler with back references
-    // disabled (to avoid infinite recursion) and then use the mangled type
-    // name as a key to check the mangling of different types for aliasing.
-
-    std::string BackReferenceKey;
-    BackRefMap::iterator Found;
-    if (UseNameBackReferences) {
-      llvm::raw_string_ostream Stream(BackReferenceKey);
-      MicrosoftCXXNameMangler Extra(Context, Stream);
-      Extra.disableBackReferences();
-      Extra.mangleUnqualifiedName(ND, Name);
-      Stream.flush();
-
-      Found = NameBackReferences.find(BackReferenceKey);
-    }
-    if (!UseNameBackReferences || Found == NameBackReferences.end()) {
-      mangleTemplateInstantiationName(TD, *TemplateArgs);
-      if (UseNameBackReferences && NameBackReferences.size() < 10) {
+    // a namespace suffix) to a string using the extra mangler and then use 
+    // the mangled type name as a key to check the mangling of different types
+    // for aliasing.
+
+    std::string TemplateMangling;
+    llvm::raw_string_ostream Stream(TemplateMangling);
+    MicrosoftCXXNameMangler Extra(Context, Stream);
+    Extra.mangleTemplateInstantiationName(TD, *TemplateArgs);
+    Stream.flush();
+
+    BackRefMap::iterator Found = NameBackReferences.find(TemplateMangling);
+    if (Found == NameBackReferences.end()) {
+      Out << TemplateMangling;
+      if (NameBackReferences.size() < 10) {
         size_t Size = NameBackReferences.size();
-        NameBackReferences[BackReferenceKey] = Size;
+        NameBackReferences[TemplateMangling] = Size;
       }
     } else {
       Out << Found->second;
@@ -1009,12 +1001,10 @@ void MicrosoftCXXNameMangler::mangleOper
 
 void MicrosoftCXXNameMangler::mangleSourceName(StringRef Name) {
   // <source name> ::= <identifier> @
-  BackRefMap::iterator Found;
-  if (UseNameBackReferences)
-    Found = NameBackReferences.find(Name);
-  if (!UseNameBackReferences || Found == NameBackReferences.end()) {
+  BackRefMap::iterator Found = NameBackReferences.find(Name);
+  if (Found == NameBackReferences.end()) {
     Out << Name << '@';
-    if (UseNameBackReferences && NameBackReferences.size() < 10) {
+    if (NameBackReferences.size() < 10) {
       size_t Size = NameBackReferences.size();
       NameBackReferences[Name] = Size;
     }