diff options
Diffstat (limited to 'src/prelude.h')
| -rw-r--r-- | src/prelude.h | 58 |
1 files changed, 56 insertions, 2 deletions
diff --git a/src/prelude.h b/src/prelude.h index 5f7203e..a0cc2a1 100644 --- a/src/prelude.h +++ b/src/prelude.h @@ -2,12 +2,66 @@ // SPDX-License-Identifier: 0BSD /** - * Configuration and feature/platform detection. + * Praeludium. + * + * This header is automatically included in every translation unit, before any + * other headers, so it can set feature test macros[1][2]. This sets up our own + * mini-dialect of C, which includes + * + * - Standard C17 and POSIX.1 2024 features + * - Portable and platform-specific extensions + * - Convenience macros like `bool`, `alignof`, etc. + * - Common compiler extensions like __has_include() + * + * Further bfs-specific utilities are defined in "bfs.h". + * + * [1]: https://www.gnu.org/software/libc/manual/html_node/Feature-Test-Macros.html + * [2]: https://pubs.opengroup.org/onlinepubs/9799919799/functions/V2_chap02.html */ #ifndef BFS_PRELUDE_H #define BFS_PRELUDE_H +// Feature test macros + +/** + * Linux and BSD handle _POSIX_C_SOURCE differently: on Linux, it enables POSIX + * interfaces that are not visible by default. On BSD, it also *disables* most + * extensions, giving a strict POSIX environment. Since we want the extensions, + * we don't set _POSIX_C_SOURCE. + */ +// #define _POSIX_C_SOURCE 202405L + +/** openat() etc. */ +#define _ATFILE_SOURCE 1 + +/** BSD-derived extensions. */ +#define _BSD_SOURCE 1 + +/** glibc successor to _BSD_SOURCE. */ +#define _DEFAULT_SOURCE 1 + +/** GNU extensions. */ +#define _GNU_SOURCE 1 + +/** Use 64-bit off_t. */ +#define _FILE_OFFSET_BITS 64 + +/** Use 64-bit time_t. */ +#define _TIME_BITS 64 + +/** macOS extensions. */ +#if __APPLE__ +# define _DARWIN_C_SOURCE 1 +#endif + +/** Solaris extensions. */ +#if __sun +# define __EXTENSIONS__ 1 +// https://illumos.org/man/3C/getpwnam#standard-conforming +# define _POSIX_PTHREAD_SEMANTICS 1 +#endif + // Get the convenience macros that became standard spellings in C23 #if __STDC_VERSION__ < 202311L @@ -20,7 +74,7 @@ /** * C23 deprecates `noreturn void` in favour of `[[noreturn]] void`, so we expose - * _noreturn instead with the other attributes. + * _noreturn instead with the other attributes in "bfs.h". */ // #include <stdnoreturn.h> |