3 files changed, 22 insertions, 9 deletions
diff --git a/include/clang/AST/Redeclarable.h b/include/clang/AST/Redeclarable.h
index 458af1f144..1e6871ff3b 100644
--- a/include/clang/AST/Redeclarable.h
+++ b/include/clang/AST/Redeclarable.h
@@ -88,6 +88,11 @@ public:
     return D;
   }
 
+  /// \brief Returns the most recent (re)declaration of this declaration.
+  const decl_type *getMostRecentDeclaration() const {
+    return getFirstDeclaration()->RedeclLink.getNext();
+  }
+  
   /// \brief Set the previous declaration. If PrevDecl is NULL, set this as the
   /// first and only declaration.
   void setPreviousDeclaration(decl_type *PrevDecl) {
diff --git a/lib/CodeGen/Mangle.cpp b/lib/CodeGen/Mangle.cpp
index b0015956be..40c11a5744 100644
--- a/lib/CodeGen/Mangle.cpp
+++ b/lib/CodeGen/Mangle.cpp
@@ -115,6 +115,7 @@ namespace {
 }
 
 static bool isInCLinkageSpecification(const Decl *D) {
+  D = D->getCanonicalDecl();
   for (const DeclContext *DC = D->getDeclContext();
        !DC->isTranslationUnit(); DC = DC->getParent()) {
     if (const LinkageSpecDecl *Linkage = dyn_cast<LinkageSpecDecl>(DC))
@@ -1362,7 +1363,7 @@ namespace clang {
                                    "Mangling declaration");
     
     CXXNameMangler Mangler(Context, os);
-    if (!Mangler.mangle(cast<NamedDecl>(D->getCanonicalDecl())))
+    if (!Mangler.mangle(D))
       return false;
 
     os.flush();
diff --git a/test/CodeGen/mangle.c b/test/CodeGen/mangle.c
index 17d74ba71f..6f42f6f649 100644
--- a/test/CodeGen/mangle.c
+++ b/test/CodeGen/mangle.c
@@ -1,22 +1,20 @@
-// RUN: clang-cc -triple i386-pc-linux-gnu -emit-llvm -o %t %s &&
-// RUN: grep '@_Z2f0i' %t &&
-// RUN: grep '@_Z2f0l' %t &&
+// RUN: clang-cc -triple i386-pc-linux-gnu -emit-llvm -o - %s | FileCheck %s
 
-// Make sure we mangle overloadable, even in C system headers.
+// CHECK: @"\01foo"
 
+// Make sure we mangle overloadable, even in C system headers.
 # 1 "somesystemheader.h" 1 3 4
+// CHECK: @_Z2f0i
 void __attribute__((__overloadable__)) f0(int a) {}
+// CHECK: @_Z2f0l
 void __attribute__((__overloadable__)) f0(long b) {}
 
-
+// CHECK: @"\01bar"
 
 // These should get merged.
 void foo() __asm__("bar");
 void foo2() __asm__("bar");
 
-// RUN: grep '@"\\01foo"' %t &&
-// RUN: grep '@"\\01bar"' %t
-
 int nux __asm__("foo");
 extern float nux2 __asm__("foo");
 
@@ -52,3 +50,12 @@ void foo6() {
 
 int foo7 __asm__("foo7") __attribute__((used));
 float foo8 __asm__("foo7") = 42;
+
+// PR4412
+int func(void);
+extern int func (void) __asm__ ("FUNC");
+
+// CHECK: @"\01FUNC"
+int func(void) {
+  return 42;
+}