From aa9e3c879305823745e3de2ff83ad562f5f45c99 Mon Sep 17 00:00:00 2001
From: Anders Carlsson <andersca@mac.com>
Date: Sat, 26 Sep 2009 20:53:44 +0000
Subject: [PATCH] Substitute "::std::" as "St".

llvm-svn: 82874
---
 clang/lib/CodeGen/Mangle.cpp               | 23 +++++++++++++++++++++-
 clang/test/CodeGenCXX/mangle-subst-std.cpp |  9 +++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)
 create mode 100644 clang/test/CodeGenCXX/mangle-subst-std.cpp

diff --git a/clang/lib/CodeGen/Mangle.cpp b/clang/lib/CodeGen/Mangle.cpp
index e07c38fd11b7..c07d9039c014 100644
--- a/clang/lib/CodeGen/Mangle.cpp
+++ b/clang/lib/CodeGen/Mangle.cpp
@@ -59,6 +59,8 @@ namespace {
     bool mangleSubstitution(QualType T);
     bool mangleSubstitution(uintptr_t Ptr);
     
+    bool mangleStandardSubstitution(const NamedDecl *ND);
+    
     void addSubstitution(const NamedDecl *ND) {
       addSubstitution(reinterpret_cast<uintptr_t>(ND));
     }
@@ -1070,8 +1072,11 @@ void CXXNameMangler::mangleTemplateArgument(const TemplateArgument &A) {
 
 // <substitution> ::= S <seq-id> _
 //                ::= S_
-
 bool CXXNameMangler::mangleSubstitution(const NamedDecl *ND) {
+  // Try one of the standard substitutions first.
+  if (mangleStandardSubstitution(ND))
+    return true;
+  
   return mangleSubstitution(reinterpret_cast<uintptr_t>(ND));
 }
 
@@ -1120,6 +1125,22 @@ bool CXXNameMangler::mangleSubstitution(uintptr_t Ptr) {
   return true;
 }
 
+bool CXXNameMangler::mangleStandardSubstitution(const NamedDecl *ND) {
+  // <substitution> ::= St # ::std::
+  
+  const NamespaceDecl *NS = dyn_cast<NamespaceDecl>(ND);
+  if (!NS)
+    return false;
+  if (!NS->getParent()->isTranslationUnit())
+    return false;
+  
+  if (!NS->getOriginalNamespace()->getIdentifier()->isStr("std"))
+    return false;
+  
+  Out << "St";
+  return true;
+}
+
 void CXXNameMangler::addSubstitution(QualType T) {
   if (!T.getCVRQualifiers()) {
     if (const RecordType *RT = T->getAs<RecordType>()) {
diff --git a/clang/test/CodeGenCXX/mangle-subst-std.cpp b/clang/test/CodeGenCXX/mangle-subst-std.cpp
new file mode 100644
index 000000000000..a5ba3ab7d08d
--- /dev/null
+++ b/clang/test/CodeGenCXX/mangle-subst-std.cpp
@@ -0,0 +1,9 @@
+// RUN: clang-cc -emit-llvm %s -o - -triple=x86_64-apple-darwin9 | FileCheck %s
+
+namespace std {
+  struct A { A(); };
+  
+  // CHECK: define void @_ZNSt1AC1Ev
+  // CHECK: define void @_ZNSt1AC2Ev
+  A::A() { }
+};