xref: /freebsd/contrib/llvm-project/clang/lib/Headers/__stddef_null.h (revision 6580f5c38dd5b01aeeaed16b370f1a12423437f0)
1 /*===---- __stddef_null.h - Definition of NULL -----------------------------===
2  *
3  * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4  * See https://llvm.org/LICENSE.txt for license information.
5  * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6  *
7  *===-----------------------------------------------------------------------===
8  */
9 
10 #if !defined(NULL) || !__building_module(_Builtin_stddef)
11 
12 /* linux/stddef.h will define NULL to 0. glibc (and other) headers then define
13  * __need_NULL and rely on stddef.h to redefine NULL to the correct value again.
14  * Modules don't support redefining macros like that, but support that pattern
15  * in the non-modules case.
16  */
17 #undef NULL
18 
19 #ifdef __cplusplus
20 #if !defined(__MINGW32__) && !defined(_MSC_VER)
21 #define NULL __null
22 #else
23 #define NULL 0
24 #endif
25 #else
26 #define NULL ((void*)0)
27 #endif
28 
29 #endif
30