1 // RUN: %clang_cc1 -fms-extensions -D MS -isystem %S/Inputs %s -fsyntax-only -verify
2 // RUN: %clang_cc1 -isystem %S/Inputs %s -fsyntax-only -verify
3 
4 // PR17824: GNU libc uses MS keyword __uptr as an identifier in C mode
5 #include <ms-keyword-system-header.h>
6 
7 void fn() {
8   WS ws;
9   ws.__uptr = 0;
10 #ifdef MS
11   // expected-error@-2 {{expected identifier}}
12 #else
13   // expected-no-diagnostics
14 #endif
15 }
16