portability.h revision 9398f05d34453e9306f7a91993ee4c8fcf1102ec 
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#if CFG_TOYBOX_DEBUG
15#define printf_format	__attribute__((format(printf, 1, 2)))
16#else
17#define printf_format
18#endif
19#else
20#define noreturn
21#define printf_format
22#endif
23
24// Always use long file support.
25#define _FILE_OFFSET_BITS 64
26
27// This isn't in the spec, but it's how we determine what libc we're using.
28
29#include <features.h>
30
31// Types various replacement prototypes need
32#include <sys/types.h>
33
34// Various constants old build environments might not have even if kernel does
35
36#ifndef AT_FDCWD
37#define AT_FDCWD -100
38#endif
39
40#ifndef AT_SYMLINK_NOFOLLOW
41#define AT_SYMLINK_NOFOLLOW 0x100
42#endif
43
44#ifndef AT_REMOVEDIR
45#define AT_REMOVEDIR 0x200
46#endif
47
48// We don't define GNU_dammit because we're not part of the gnu project, and
49// don't want to get any FSF on us. Unfortunately glibc (gnu libc)
50// won't give us Linux syscall wrappers without claiming to be part of the
51// gnu project (because Stallman's "GNU owns Linux" revisionist history
52// crusade includes the kernel, even though Linux was inspired by Minix).
53
54// We use most non-posix Linux syscalls directly through the syscall() wrapper,
55// but even many posix-2008 functions aren't provided by glibc unless you
56// claim it's in the name of Gnu.
57
58#if defined(__GLIBC__)
59// "Function prototypes shall be provided." but aren't.
60// http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/unistd.h.html
61char *crypt(const char *key, const char *salt);
62
63// According to posix, #include header, get a function definition. But glibc...
64// http://pubs.opengroup.org/onlinepubs/9699919799/functions/wcwidth.html
65#include <wchar.h>
66int wcwidth(wchar_t wc);
67
68// see http://pubs.opengroup.org/onlinepubs/9699919799/functions/strptime.html
69#include <time.h>
70char *strptime(const char *buf, const char *format, struct tm *tm);
71
72// They didn't like posix basename so they defined another function with the
73// same name and if you include libgen.h it #defines basename to something
74// else (where they implemented the real basename), and that define breaks
75// the table entry for the basename command. They didn't make a new function
76// with a different name for their new behavior because gnu.
77//
78// Solution: don't use their broken header, provide an inline to redirect the
79// correct name to the broken name.
80
81char *dirname(char *path);
82char *__xpg_basename (char *path);
83static inline char *basename(char *path) { return __xpg_basename(path); }
84
85// uClibc pretends to be glibc and copied a lot of its bugs, but has a few more
86#if defined(__UCLIBC__)
87#include <unistd.h>
88#include <stdio.h>
89ssize_t getdelim(char **lineptr, size_t *n, int delim, FILE *stream);
90char *stpcpy(char *dest, const char *src);
91pid_t getsid(pid_t pid);
92
93// uClibc's last-ever release was in 2012, so of course it doesn't define
94// any flag newer than MS_MOVE, which was added in 2001 (linux 2.5.0.5),
95// eleven years earlier.
96
97#include <sys/mount.h>
98#ifndef MS_MOVE
99#define MS_MOVE       (1<<13)
100#endif
101#ifndef MS_REC
102#define MS_REC        (1<<14)
103#endif
104#ifndef MS_SILENT
105#define MS_SILENT     (1<<15)
106#endif
107#ifndef MS_UNBINDABLE
108#define MS_UNBINDABLE (1<<17)
109#endif
110#ifndef MS_PRIVATE
111#define MS_PRIVATE    (1<<18)
112#endif
113#ifndef MS_SLAVE
114#define MS_SLAVE      (1<<19)
115#endif
116#ifndef MS_SHARED
117#define MS_SHARED     (1<<20)
118#endif
119
120// When building under obsolete glibc (Ubuntu 8.04-ish), hold its hand a bit.
121#elif __GLIBC__ == 2 && __GLIBC_MINOR__ < 10
122#define fstatat fstatat64
123int fstatat64(int dirfd, const char *pathname, void *buf, int flags);
124int readlinkat(int dirfd, const char *pathname, char *buf, size_t bufsiz);
125char *stpcpy(char *dest, const char *src);
126#include <sys/stat.h>
127int fchmodat(int dirfd, const char *pathname, mode_t mode, int flags);
128int openat(int dirfd, const char *pathname, int flags, ...);
129#include <dirent.h>
130DIR *fdopendir(int fd);
131#include <unistd.h>
132int fchownat(int dirfd, const char *pathname,
133                    uid_t owner, gid_t group, int flags);
134int isblank(int c);
135int unlinkat(int dirfd, const char *pathname, int flags);
136#include <stdio.h>
137ssize_t getdelim(char **lineptr, size_t *n, int delim, FILE *stream);
138
139// Straight from posix-2008, things old glibc had but didn't prototype
140
141int faccessat(int fd, const char *path, int amode, int flag);
142int linkat(int fd1, const char *path1, int fd2, const char *path2, int flag);
143int mkdirat(int fd, const char *path, mode_t mode);
144int symlinkat(const char *path1, int fd, const char *path2);
145int mknodat(int fd, const char *path, mode_t mode, dev_t dev);
146#include <sys/time.h>
147int futimens(int fd, const struct timespec times[2]);
148int utimensat(int fd, const char *path, const struct timespec times[2], int flag);
149
150#ifndef MNT_DETACH
151#define MNT_DETACH 2
152#endif
153#endif // Old glibc
154
155#endif // glibc in general
156
157#ifndef __GLIBC__
158// POSIX basename.
159#include <libgen.h>
160#endif
161
162// Work out how to do endianness
163
164#ifndef __APPLE__
165#include <byteswap.h>
166#include <endian.h>
167
168#if __BYTE_ORDER == __BIG_ENDIAN
169#define IS_BIG_ENDIAN 1
170#else
171#define IS_BIG_ENDIAN 0
172#endif
173
174int clearenv(void);
175#else
176
177#ifdef __BIG_ENDIAN__
178#define IS_BIG_ENDIAN 1
179#else
180#define IS_BIG_ENDIAN 0
181#endif
182
183#endif
184
185#if IS_BIG_ENDIAN
186#define IS_LITTLE_ENDIAN 0
187#define SWAP_BE16(x) (x)
188#define SWAP_BE32(x) (x)
189#define SWAP_BE64(x) (x)
190#define SWAP_LE16(x) bswap_16(x)
191#define SWAP_LE32(x) bswap_32(x)
192#define SWAP_LE64(x) bswap_64(x)
193#else
194#define IS_LITTLE_ENDIAN 1
195#define SWAP_BE16(x) bswap_16(x)
196#define SWAP_BE32(x) bswap_32(x)
197#define SWAP_BE64(x) bswap_64(x)
198#define SWAP_LE16(x) (x)
199#define SWAP_LE32(x) (x)
200#define SWAP_LE64(x) (x)
201#endif
202
203#if defined(__APPLE__) \
204    || (defined(__GLIBC__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 10)
205ssize_t getdelim(char **lineptr, size_t *n, int delim, FILE *stream);
206ssize_t getline(char **lineptr, size_t *n, FILE *stream);
207#endif
208
209// Linux headers not listed by POSIX or LSB
210#include <sys/mount.h>
211#include <sys/swap.h>
212
213// Android is missing some headers and functions
214// "generated/config.h" is included first
215#if CFG_TOYBOX_SHADOW
216#include <shadow.h>
217#endif
218#if CFG_TOYBOX_UTMPX
219#include <utmpx.h>
220#endif
221
222// Some systems don't define O_NOFOLLOW, and it varies by architecture, so...
223#include <fcntl.h>
224#ifndef O_NOFOLLOW
225#define O_NOFOLLOW 0
226#endif
227
228#ifndef O_CLOEXEC
229#define O_CLOEXEC 02000000
230#endif
231
232#ifndef O_PATH
233#define O_PATH   010000000
234#endif
235
236#if defined(__SIZEOF_DOUBLE__) && defined(__SIZEOF_LONG__) \
237    && __SIZEOF_DOUBLE__ <= __SIZEOF_LONG__
238typedef double FLOAT;
239#else
240typedef float FLOAT;
241#endif
242
243#ifndef __uClinux__
244pid_t xfork(void);
245#endif
246
247//#define strncpy(...) @@strncpyisbadmmkay@@
248//#define strncat(...) @@strcatisbadmmkay@@
249
250#if CFG_TOYBOX_SELINUX
251#include <selinux/selinux.h>
252#else
253#define is_selinux_enabled() 0
254int getcon(void* con);
255#endif
256
257#if CFG_TOYBOX_SMACK
258#include <sys/smack.h>
259#include <sys/xattr.h>
260#include <linux/xattr.h>
261#else
262#define smack_new_label_from_path(...) (-1)
263#define smack_set_label_for_path(...)  (-1)
264#define smack_set_label_for_self(...)  (-1)
265#define XATTR_NAME_SMACK ""
266#define SMACK_LABEL_LEN  (1) /* for just ? */
267
268ssize_t fgetxattr (int fd, char *name, void *value, size_t size);
269#endif
270
271