2 files changed, 17 insertions, 0 deletions
diff --git a/lib/AST/ItaniumMangle.cpp b/lib/AST/ItaniumMangle.cpp
index e9a3b03483..1f95a2fee0 100644
--- a/lib/AST/ItaniumMangle.cpp
+++ b/lib/AST/ItaniumMangle.cpp
@@ -381,6 +381,15 @@ bool ItaniumMangleContext::shouldMangleDeclName(const NamedDecl *D) {
     // mangling.
     if (!FD->getDeclName().isIdentifier() || L == CXXLanguageLinkage)
       return true;
+
+    // FIXME: Users assume they know the mangling of static functions
+    // declared in extern "C" contexts, so we cannot always mangle them.
+    // As an improvement, maybe we could mangle them only if they are actually
+    // overloaded.
+    const DeclContext *DC = FD->getDeclContext();
+    if (!DC->isRecord() &&
+        FD->getFirstDeclaration()->getDeclContext()->isExternCContext())
+      return false;
   }
 
   // Otherwise, no mangling is done outside C++ mode.
diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index 9bba5f6c78..20fb7a768b 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -974,6 +974,14 @@ static bool canBeOverloaded(const FunctionDecl &D) {
   if (D.isMain())
     return false;
 
+  // FIXME: Users assume they know the mangling of static functions
+  // declared in extern "C" contexts. For now just disallow overloading these
+  // functions so that we can avoid mangling them.
+  const DeclContext *DC = D.getDeclContext();
+  if (!DC->isRecord() &&
+      D.getFirstDeclaration()->getDeclContext()->isExternCContext())
+    return false;
+
   return true;
 }