1 // Workarounds for horrible build environment idiosyncrasies.
2
3 // Instead of polluting the code with strange #ifdefs to work around bugs
4 // in specific compiler, library, or OS versions, localize all that here
5 // and in portability.c
6
7 // For musl
8 #define _ALL_SOURCE
9
10 // Test for gcc (using compiler builtin #define)
11
12 #ifdef __GNUC__
13 #define noreturn __attribute__((noreturn))
14 #define printf_format __attribute__((format(printf, 1, 2)))
15 #else
16 #define noreturn
17 #define printf_format
18 #endif
19
20 // Always use long file support.
21 #define _FILE_OFFSET_BITS 64
22
23 // This isn't in the spec, but it's how we determine what libc we're using.
24
25 #include <features.h>
26
27 // Types various replacement prototypes need
28 #include <sys/types.h>
29
30 // Various constants old build environments might not have even if kernel does
31
32 #ifndef AT_FDCWD
33 #define AT_FDCWD -100
34 #endif
35
36 #ifndef AT_SYMLINK_NOFOLLOW
37 #define AT_SYMLINK_NOFOLLOW 0x100
38 #endif
39
40 #ifndef AT_REMOVEDIR
41 #define AT_REMOVEDIR 0x200
42 #endif
43
44 #ifndef RLIMIT_RTTIME
45 #define RLIMIT_RTTIME 15
46 #endif
47
48 #ifndef SEEK_DATA
49 #define SEEK_DATA 3
50 #endif
51
52 // We don't define GNU_dammit because we're not part of the gnu project, and
53 // don't want to get any FSF on us. Unfortunately glibc (gnu libc)
54 // won't give us Linux syscall wrappers without claiming to be part of the
55 // gnu project (because Stallman's "GNU owns Linux" revisionist history
56 // crusade includes the kernel, even though Linux was inspired by Minix).
57
58 // We use most non-posix Linux syscalls directly through the syscall() wrapper,
59 // but even many posix-2008 functions aren't provided by glibc unless you
60 // claim it's in the name of Gnu.
61
62 #if defined(__GLIBC__)
63 // "Function prototypes shall be provided." but aren't.
64 // http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/unistd.h.html
65 char *crypt(const char *key, const char *salt);
66
67 // According to posix, #include header, get a function definition. But glibc...
68 // http://pubs.opengroup.org/onlinepubs/9699919799/functions/wcwidth.html
69 #include <wchar.h>
70 int wcwidth(wchar_t wc);
71
72 // see http://pubs.opengroup.org/onlinepubs/9699919799/functions/strptime.html
73 #include <time.h>
74 char *strptime(const char *buf, const char *format, struct tm *tm);
75
76 // They didn't like posix basename so they defined another function with the
77 // same name and if you include libgen.h it #defines basename to something
78 // else (where they implemented the real basename), and that define breaks
79 // the table entry for the basename command. They didn't make a new function
80 // with a different name for their new behavior because gnu.
81 //
82 // Solution: don't use their broken header, provide an inline to redirect the
83 // correct name to the broken name.
84
85 char *dirname(char *path);
86 char *__xpg_basename(char *path);
basename(char * path)87 static inline char *basename(char *path) { return __xpg_basename(path); }
88
89 // uClibc pretends to be glibc and copied a lot of its bugs, but has a few more
90 #if defined(__UCLIBC__)
91 #include <unistd.h>
92 #include <stdio.h>
93 ssize_t getdelim(char **lineptr, size_t *n, int delim, FILE *stream);
94 char *stpcpy(char *dest, const char *src);
95 pid_t getsid(pid_t pid);
96
97 // uClibc's last-ever release was in 2012, so of course it doesn't define
98 // any flag newer than MS_MOVE, which was added in 2001 (linux 2.5.0.5),
99 // eleven years earlier.
100
101 #include <sys/mount.h>
102 #ifndef MS_MOVE
103 #define MS_MOVE (1<<13)
104 #endif
105 #ifndef MS_REC
106 #define MS_REC (1<<14)
107 #endif
108 #ifndef MS_SILENT
109 #define MS_SILENT (1<<15)
110 #endif
111 #ifndef MS_UNBINDABLE
112 #define MS_UNBINDABLE (1<<17)
113 #endif
114 #ifndef MS_PRIVATE
115 #define MS_PRIVATE (1<<18)
116 #endif
117 #ifndef MS_SLAVE
118 #define MS_SLAVE (1<<19)
119 #endif
120 #ifndef MS_SHARED
121 #define MS_SHARED (1<<20)
122 #endif
123 #ifndef MS_RELATIME
124 #define MS_RELATIME (1<<21)
125 #endif
126
127 // When building under obsolete glibc (Ubuntu 8.04-ish), hold its hand a bit.
128 #elif __GLIBC__ == 2 && __GLIBC_MINOR__ < 10
129 #define fstatat fstatat64
130 int fstatat64(int dirfd, const char *pathname, void *buf, int flags);
131 int readlinkat(int dirfd, const char *pathname, char *buf, size_t bufsiz);
132 char *stpcpy(char *dest, const char *src);
133 #include <sys/stat.h>
134 int fchmodat(int dirfd, const char *pathname, mode_t mode, int flags);
135 int openat(int dirfd, const char *pathname, int flags, ...);
136 #include <dirent.h>
137 DIR *fdopendir(int fd);
138 #include <unistd.h>
139 int fchownat(int dirfd, const char *pathname,
140 uid_t owner, gid_t group, int flags);
141 int isblank(int c);
142 int unlinkat(int dirfd, const char *pathname, int flags);
143 #include <stdio.h>
144 ssize_t getdelim(char **lineptr, size_t *n, int delim, FILE *stream);
145
146 // Straight from posix-2008, things old glibc had but didn't prototype
147
148 int faccessat(int fd, const char *path, int amode, int flag);
149 int linkat(int fd1, const char *path1, int fd2, const char *path2, int flag);
150 int mkdirat(int fd, const char *path, mode_t mode);
151 int symlinkat(const char *path1, int fd, const char *path2);
152 int mknodat(int fd, const char *path, mode_t mode, dev_t dev);
153 #include <sys/time.h>
154 int futimens(int fd, const struct timespec times[2]);
155 int utimensat(int fd, const char *path, const struct timespec times[2], int flag);
156
157 #ifndef MNT_DETACH
158 #define MNT_DETACH 2
159 #endif
160 #endif // Old glibc
161
162 #endif // glibc in general
163
164 #if !defined(__GLIBC__)
165 // POSIX basename.
166 #include <libgen.h>
167 #endif
168
169 // Work out how to do endianness
170
171 #ifndef __APPLE__
172 #include <byteswap.h>
173 #include <endian.h>
174
175 #if __BYTE_ORDER == __BIG_ENDIAN
176 #define IS_BIG_ENDIAN 1
177 #else
178 #define IS_BIG_ENDIAN 0
179 #endif
180
181 int clearenv(void);
182 #else
183
184 #ifdef __BIG_ENDIAN__
185 #define IS_BIG_ENDIAN 1
186 #else
187 #define IS_BIG_ENDIAN 0
188 #endif
189
190 #endif
191
192 #if IS_BIG_ENDIAN
193 #define IS_LITTLE_ENDIAN 0
194 #define SWAP_BE16(x) (x)
195 #define SWAP_BE32(x) (x)
196 #define SWAP_BE64(x) (x)
197 #define SWAP_LE16(x) bswap_16(x)
198 #define SWAP_LE32(x) bswap_32(x)
199 #define SWAP_LE64(x) bswap_64(x)
200 #else
201 #define IS_LITTLE_ENDIAN 1
202 #define SWAP_BE16(x) bswap_16(x)
203 #define SWAP_BE32(x) bswap_32(x)
204 #define SWAP_BE64(x) bswap_64(x)
205 #define SWAP_LE16(x) (x)
206 #define SWAP_LE32(x) (x)
207 #define SWAP_LE64(x) (x)
208 #endif
209
210 #if defined(__APPLE__) \
211 || (defined(__GLIBC__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 10)
212 ssize_t getdelim(char **lineptr, size_t *n, int delim, FILE *stream);
213 ssize_t getline(char **lineptr, size_t *n, FILE *stream);
214 #endif
215
216 // Linux headers not listed by POSIX or LSB
217 #include <sys/mount.h>
218 #include <sys/swap.h>
219
220 // Android is missing some headers and functions
221 // "generated/config.h" is included first
222 #if CFG_TOYBOX_SHADOW
223 #include <shadow.h>
224 #endif
225 #if CFG_TOYBOX_UTMPX
226 #include <utmpx.h>
227 #else
228 struct utmpx {int ut_type;};
229 #define USER_PROCESS 0
getutxent(void)230 static inline struct utmpx *getutxent(void) {return 0;}
setutxent(void)231 static inline void setutxent(void) {;}
endutxent(void)232 static inline void endutxent(void) {;}
233 #endif
234
235 // Some systems don't define O_NOFOLLOW, and it varies by architecture, so...
236 #include <fcntl.h>
237 #ifndef O_NOFOLLOW
238 #define O_NOFOLLOW 0
239 #endif
240
241 #ifndef O_NOATIME
242 #define O_NOATIME 01000000
243 #endif
244
245 #ifndef O_CLOEXEC
246 #define O_CLOEXEC 02000000
247 #endif
248
249 #ifndef O_PATH
250 #define O_PATH 010000000
251 #endif
252
253 // Glibc won't give you linux-kernel constants unless you say "no, a BUD lite"
254 // even though linux has nothing to do with the FSF and never has.
255 #ifndef F_SETPIPE_SZ
256 #define F_SETPIPE_SZ 1031
257 #endif
258
259 #ifndef F_GETPIPE_SZ
260 #define F_GETPIPE_SZ 1032
261 #endif
262
263 #if defined(__SIZEOF_DOUBLE__) && defined(__SIZEOF_LONG__) \
264 && __SIZEOF_DOUBLE__ <= __SIZEOF_LONG__
265 typedef double FLOAT;
266 #else
267 typedef float FLOAT;
268 #endif
269
270 #ifndef __uClinux__
271 pid_t xfork(void);
272 #endif
273
274 //#define strncpy(...) @@strncpyisbadmmkay@@
275 //#define strncat(...) @@strncatisbadmmkay@@
276
277 #ifdef __ANDROID__
278 #include <cutils/sched_policy.h>
279 #else
get_sched_policy(int tid,void * policy)280 static inline int get_sched_policy(int tid, void *policy) {return 0;}
get_sched_policy_name(int policy)281 static inline char *get_sched_policy_name(int policy) {return "unknown";}
282 #endif
283