From b217c1b9d2225521f4021984ad5a424784fa22bb Mon Sep 17 00:00:00 2001
From: Anders Carlsson <andersca@mac.com>
Date: Tue, 6 Oct 2009 21:58:01 +0000
Subject: [PATCH] When mangling names, always use the canonical decl. Fixes
 PR5144.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@83420 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/Mangle.cpp     | 2 +-
 test/CodeGenCXX/mangle.cpp | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/lib/CodeGen/Mangle.cpp b/lib/CodeGen/Mangle.cpp
index 7555ae5da4..702edf05a9 100644
--- a/lib/CodeGen/Mangle.cpp
+++ b/lib/CodeGen/Mangle.cpp
@@ -1303,7 +1303,7 @@ namespace clang {
                                    "Mangling declaration");
     
     CXXNameMangler Mangler(Context, os);
-    if (!Mangler.mangle(D))
+    if (!Mangler.mangle(cast<NamedDecl>(D->getCanonicalDecl())))
       return false;
 
     os.flush();
diff --git a/test/CodeGenCXX/mangle.cpp b/test/CodeGenCXX/mangle.cpp
index 86f5fb0d5b..a881a710d4 100644
--- a/test/CodeGenCXX/mangle.cpp
+++ b/test/CodeGenCXX/mangle.cpp
@@ -198,3 +198,12 @@ template<typename T> typename __enable_if<__is_scalar<T>::__value, void>::__type
 template void ft7<int>();
 // CHECK: @_Z3ft7IPvEN11__enable_ifIXsr11__is_scalarIT_E7__valueEvE6__typeEv
 template void ft7<void*>();
+
+// PR5144
+extern "C" {
+void extern_f(void);
+};
+
+// CHECK: @extern_f
+void extern_f(void) { }
+