1 files changed, 20 insertions, 0 deletions
diff --git a/clang/test/Sema/extern-redecl.c b/clang/test/Sema/extern-redecl.c
index 64885a08d34..e9a4c571bd2 100644
--- a/clang/test/Sema/extern-redecl.c
+++ b/clang/test/Sema/extern-redecl.c
@@ -42,3 +42,23 @@ void test4() {
   }
   int x = sizeof(test4_array); // expected-error {{invalid application of 'sizeof' to an incomplete type 'int []'}}
 }
+
+// Test that invalid local extern declarations of library
+// builtins behave reasonably.
+extern void abort(void); // expected-note 2 {{previous declaration is here}}
+extern float *calloc(); // expected-warning {{incompatible redeclaration of library function}} expected-note {{is a builtin}} expected-note 2 {{previous declaration is here}}
+void test5a() {
+  int abort(); // expected-error {{conflicting types}}
+  float *malloc(); // expected-warning {{incompatible redeclaration of library function}} expected-note 2 {{is a builtin}}
+  int *calloc(); // expected-error {{conflicting types}}
+}
+void test5b() {
+  int abort(); // expected-error {{conflicting types}}
+  float *malloc(); // expected-warning {{incompatible redeclaration of library function}}
+  int *calloc(); // expected-error {{conflicting types}}
+}
+void test5c() {
+  void (*_abort)(void) = &abort;
+  void *(*_malloc)() = &malloc;
+  float *(*_calloc)() = &calloc;
+}