1 /*===---- stdarg.h - Variable argument handling ----------------------------=== 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 /* 11 * This header is designed to be included multiple times. If any of the __need_ 12 * macros are defined, then only that subset of interfaces are provided. This 13 * can be useful for POSIX headers that need to not expose all of stdarg.h, but 14 * need to use some of its interfaces. Otherwise this header provides all of 15 * the expected interfaces. 16 * 17 * When clang modules are enabled, this header is a textual header. It ignores 18 * its header guard so that multiple submodules can export its interfaces. 19 * Take module SM with submodules A and B, whose headers both include stdarg.h 20 * When SM.A builds, __STDARG_H will be defined. When SM.B builds, the 21 * definition from SM.A will leak when building without local submodule 22 * visibility. stdarg.h wouldn't include any of its implementation headers, and 23 * SM.B wouldn't import any of the stdarg modules, and SM.B's `export *` 24 * wouldn't export any stdarg interfaces as expected. However, since stdarg.h 25 * ignores its header guard when building with modules, it all works as 26 * expected. 27 * 28 * When clang modules are not enabled, the header guards can function in the 29 * normal simple fashion. 30 */ 31 #if !defined(__STDARG_H) || __has_feature(modules) || \ 32 defined(__need___va_list) || defined(__need_va_list) || \ 33 defined(__need_va_arg) || defined(__need___va_copy) || \ 34 defined(__need_va_copy) 35 36 #if !defined(__need___va_list) && !defined(__need_va_list) && \ 37 !defined(__need_va_arg) && !defined(__need___va_copy) && \ 38 !defined(__need_va_copy) 39 #define __STDARG_H 40 #define __need___va_list 41 #define __need_va_list 42 #define __need_va_arg 43 #define __need___va_copy 44 /* GCC always defines __va_copy, but does not define va_copy unless in c99 mode 45 * or -ansi is not specified, since it was not part of C90. 46 */ 47 #if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) || \ 48 (defined(__cplusplus) && __cplusplus >= 201103L) || \ 49 !defined(__STRICT_ANSI__) 50 #define __need_va_copy 51 #endif 52 #endif 53 54 #ifdef __need___va_list 55 #include <__stdarg___gnuc_va_list.h> 56 #undef __need___va_list 57 #endif /* defined(__need___va_list) */ 58 59 #ifdef __need_va_list 60 #include <__stdarg_va_list.h> 61 #undef __need_va_list 62 #endif /* defined(__need_va_list) */ 63 64 #ifdef __need_va_arg 65 #include <__stdarg_va_arg.h> 66 #undef __need_va_arg 67 #endif /* defined(__need_va_arg) */ 68 69 #ifdef __need___va_copy 70 #include <__stdarg___va_copy.h> 71 #undef __need___va_copy 72 #endif /* defined(__need___va_copy) */ 73 74 #ifdef __need_va_copy 75 #include <__stdarg_va_copy.h> 76 #undef __need_va_copy 77 #endif /* defined(__need_va_copy) */ 78 79 #endif 80