Don't get confused if a extern "C" builtin function is redeclared without

the extern "C".

llvm-svn: 171260

clang/lib/AST/Decl.cpp

@@ -2440,7 +2440,7 @@ unsigned FunctionDecl::getMemoryFunctionKind() const {
     return Builtin::BIstrlen;
 
   default:
-    if (isExternC()) {
+    if (hasCLanguageLinkage()) {
       if (FnInfo->isStr("memset"))
         return Builtin::BImemset;
       else if (FnInfo->isStr("memcpy"))

clang/test/SemaCXX/warn-bad-memaccess.cpp

@@ -5,6 +5,11 @@ extern "C" void *memmove(void *s1, const void *s2, unsigned n);
 extern "C" void *memcpy(void *s1, const void *s2, unsigned n);
 extern "C" void *memcmp(void *s1, const void *s2, unsigned n);
 
+
+// Redeclare without the extern "C" to test that we still figure out that this
+// is the "real" memset.
+void *memset(void *, int, unsigned);
+
 // Several types that should not warn.
 struct S1 {} s1;
 struct S2 { int x; } s2;