LXR busybox/include/platform.h

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * Copyright 2006, Bernhard Reutner-Fischer
   4 *
   5 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   6 */
   7#ifndef BB_PLATFORM_H
   8#define BB_PLATFORM_H 1
   9
  10
  11/* Convenience macros to test the version of gcc. */
  12#undef __GNUC_PREREQ
  13#if defined __GNUC__ && defined __GNUC_MINOR__
  14# define __GNUC_PREREQ(maj, min) \
  15                ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
  16#else
  17# define __GNUC_PREREQ(maj, min) 0
  18#endif
  19
  20/* __restrict is known in EGCS 1.2 and above. */
  21#if !__GNUC_PREREQ(2,92)
  22# ifndef __restrict
  23#  define __restrict
  24# endif
  25#endif
  26
  27#if !__GNUC_PREREQ(2,7)
  28# ifndef __attribute__
  29#  define __attribute__(x)
  30# endif
  31#endif
  32
  33#undef inline
  34#if defined(__STDC_VERSION__) && __STDC_VERSION__ > 199901L
  35/* it's a keyword */
  36#elif __GNUC_PREREQ(2,7)
  37# define inline __inline__
  38#else
  39# define inline
  40#endif
  41
  42#ifndef __const
  43# define __const const
  44#endif
  45
  46#define UNUSED_PARAM __attribute__ ((__unused__))
  47#define NORETURN __attribute__ ((__noreturn__))
  48/* "The malloc attribute is used to tell the compiler that a function
  49 * may be treated as if any non-NULL pointer it returns cannot alias
  50 * any other pointer valid when the function returns. This will often
  51 * improve optimization. Standard functions with this property include
  52 * malloc and calloc. realloc-like functions have this property as long
  53 * as the old pointer is never referred to (including comparing it
  54 * to the new pointer) after the function returns a non-NULL value."
  55 */
  56#define RETURNS_MALLOC __attribute__ ((malloc))
  57#define PACKED __attribute__ ((__packed__))
  58#define ALIGNED(m) __attribute__ ((__aligned__(m)))
  59
  60/* __NO_INLINE__: some gcc's do not honor inlining! :( */
  61#if __GNUC_PREREQ(3,0) && !defined(__NO_INLINE__)
  62# define ALWAYS_INLINE __attribute__ ((always_inline)) inline
  63/* I've seen a toolchain where I needed __noinline__ instead of noinline */
  64# define NOINLINE      __attribute__((__noinline__))
  65# if !ENABLE_WERROR
  66#  define DEPRECATED __attribute__ ((__deprecated__))
  67#  define UNUSED_PARAM_RESULT __attribute__ ((warn_unused_result))
  68# else
  69#  define DEPRECATED
  70#  define UNUSED_PARAM_RESULT
  71# endif
  72#else
  73# define ALWAYS_INLINE inline
  74# define NOINLINE
  75# define DEPRECATED
  76# define UNUSED_PARAM_RESULT
  77#endif
  78
  79/* -fwhole-program makes all symbols local. The attribute externally_visible
  80 * forces a symbol global.  */
  81#if __GNUC_PREREQ(4,1)
  82# define EXTERNALLY_VISIBLE __attribute__(( visibility("default") ))
  83//__attribute__ ((__externally_visible__))
  84#else
  85# define EXTERNALLY_VISIBLE
  86#endif
  87
  88/* At 4.4 gcc become much more anal about this, need to use "aliased" types */
  89#if __GNUC_PREREQ(4,4)
  90# define FIX_ALIASING __attribute__((__may_alias__))
  91#else
  92# define FIX_ALIASING
  93#endif
  94
  95/* We use __extension__ in some places to suppress -pedantic warnings
  96 * about GCC extensions.  This feature didn't work properly before
  97 * gcc 2.8.  */
  98#if !__GNUC_PREREQ(2,8)
  99# ifndef __extension__
 100#  define __extension__
 101# endif
 102#endif
 103
 104/* FAST_FUNC is a qualifier which (possibly) makes function call faster
 105 * and/or smaller by using modified ABI. It is usually only needed
 106 * on non-static, busybox internal functions. Recent versions of gcc
 107 * optimize statics automatically. FAST_FUNC on static is required
 108 * only if you need to match a function pointer's type */
 109#if __GNUC_PREREQ(3,0) && defined(i386) /* || defined(__x86_64__)? */
 110/* stdcall makes callee to pop arguments from stack, not caller */
 111# define FAST_FUNC __attribute__((regparm(3),stdcall))
 112/* #elif ... - add your favorite arch today! */
 113#else
 114# define FAST_FUNC
 115#endif
 116
 117/* Make all declarations hidden (-fvisibility flag only affects definitions) */
 118/* (don't include system headers after this until corresponding pop!) */
 119#if __GNUC_PREREQ(4,1) && !defined(__CYGWIN__)
 120# define PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN _Pragma("GCC visibility push(hidden)")
 121# define POP_SAVED_FUNCTION_VISIBILITY              _Pragma("GCC visibility pop")
 122#else
 123# define PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
 124# define POP_SAVED_FUNCTION_VISIBILITY
 125#endif
 126
 127/* gcc-2.95 had no va_copy but only __va_copy. */
 128#if !__GNUC_PREREQ(3,0)
 129# include <stdarg.h>
 130# if !defined va_copy && defined __va_copy
 131#  define va_copy(d,s) __va_copy((d),(s))
 132# endif
 133#endif
 134
 135
 136/* ---- Endian Detection ------------------------------------ */
 137
 138#include <limits.h>
 139#if defined(__digital__) && defined(__unix__)
 140# include <sex.h>
 141#elif defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
 142   || defined(__APPLE__)
 143# include <sys/resource.h>  /* rlimit */
 144# include <machine/endian.h>
 145# define bswap_64 __bswap64
 146# define bswap_32 __bswap32
 147# define bswap_16 __bswap16
 148#else
 149# include <byteswap.h>
 150# include <endian.h>
 151#endif
 152
 153#if defined(__BYTE_ORDER) && __BYTE_ORDER == __BIG_ENDIAN
 154# define BB_BIG_ENDIAN 1
 155# define BB_LITTLE_ENDIAN 0
 156#elif defined(__BYTE_ORDER) && __BYTE_ORDER == __LITTLE_ENDIAN
 157# define BB_BIG_ENDIAN 0
 158# define BB_LITTLE_ENDIAN 1
 159#elif defined(_BYTE_ORDER) && _BYTE_ORDER == _BIG_ENDIAN
 160# define BB_BIG_ENDIAN 1
 161# define BB_LITTLE_ENDIAN 0
 162#elif defined(_BYTE_ORDER) && _BYTE_ORDER == _LITTLE_ENDIAN
 163# define BB_BIG_ENDIAN 0
 164# define BB_LITTLE_ENDIAN 1
 165#elif defined(BYTE_ORDER) && BYTE_ORDER == BIG_ENDIAN
 166# define BB_BIG_ENDIAN 1
 167# define BB_LITTLE_ENDIAN 0
 168#elif defined(BYTE_ORDER) && BYTE_ORDER == LITTLE_ENDIAN
 169# define BB_BIG_ENDIAN 0
 170# define BB_LITTLE_ENDIAN 1
 171#elif defined(__386__)
 172# define BB_BIG_ENDIAN 0
 173# define BB_LITTLE_ENDIAN 1
 174#else
 175# error "Can't determine endianness"
 176#endif
 177
 178#if ULONG_MAX > 0xffffffff
 179# define bb_bswap_64(x) bswap_64(x)
 180#endif
 181
 182/* SWAP_LEnn means "convert CPU<->little_endian by swapping bytes" */
 183#if BB_BIG_ENDIAN
 184# define SWAP_BE16(x) (x)
 185# define SWAP_BE32(x) (x)
 186# define SWAP_BE64(x) (x)
 187# define SWAP_LE16(x) bswap_16(x)
 188# define SWAP_LE32(x) bswap_32(x)
 189# define SWAP_LE64(x) bb_bswap_64(x)
 190# define IF_BIG_ENDIAN(...) __VA_ARGS__
 191# define IF_LITTLE_ENDIAN(...)
 192#else
 193# define SWAP_BE16(x) bswap_16(x)
 194# define SWAP_BE32(x) bswap_32(x)
 195# define SWAP_BE64(x) bb_bswap_64(x)
 196# define SWAP_LE16(x) (x)
 197# define SWAP_LE32(x) (x)
 198# define SWAP_LE64(x) (x)
 199# define IF_BIG_ENDIAN(...)
 200# define IF_LITTLE_ENDIAN(...) __VA_ARGS__
 201#endif
 202
 203
 204/* ---- Unaligned access ------------------------------------ */
 205
 206#include <stdint.h>
 207typedef int      bb__aliased_int      FIX_ALIASING;
 208typedef uint16_t bb__aliased_uint16_t FIX_ALIASING;
 209typedef uint32_t bb__aliased_uint32_t FIX_ALIASING;
 210
 211/* NB: unaligned parameter should be a pointer, aligned one -
 212 * a lvalue. This makes it more likely to not swap them by mistake
 213 */
 214#if defined(i386) || defined(__x86_64__) || defined(__powerpc__)
 215# define move_from_unaligned_int(v, intp) ((v) = *(bb__aliased_int*)(intp))
 216# define move_from_unaligned16(v, u16p) ((v) = *(bb__aliased_uint16_t*)(u16p))
 217# define move_from_unaligned32(v, u32p) ((v) = *(bb__aliased_uint32_t*)(u32p))
 218# define move_to_unaligned16(u16p, v)   (*(bb__aliased_uint16_t*)(u16p) = (v))
 219# define move_to_unaligned32(u32p, v)   (*(bb__aliased_uint32_t*)(u32p) = (v))
 220/* #elif ... - add your favorite arch today! */
 221#else
 222/* performs reasonably well (gcc usually inlines memcpy here) */
 223# define move_from_unaligned_int(v, intp) (memcpy(&(v), (intp), sizeof(int)))
 224# define move_from_unaligned16(v, u16p) (memcpy(&(v), (u16p), 2))
 225# define move_from_unaligned32(v, u32p) (memcpy(&(v), (u32p), 4))
 226# define move_to_unaligned16(u16p, v) do { \
 227        uint16_t __t = (v); \
 228        memcpy((u16p), &__t, 4); \
 229} while (0)
 230# define move_to_unaligned32(u32p, v) do { \
 231        uint32_t __t = (v); \
 232        memcpy((u32p), &__t, 4); \
 233} while (0)
 234#endif
 235
 236
 237/* ---- Size-saving "small" ints (arch-dependent) ----------- */
 238
 239#if defined(i386) || defined(__x86_64__) || defined(__mips__) || defined(__cris__)
 240/* add other arches which benefit from this... */
 241typedef signed char smallint;
 242typedef unsigned char smalluint;
 243#else
 244/* for arches where byte accesses generate larger code: */
 245typedef int smallint;
 246typedef unsigned smalluint;
 247#endif
 248
 249/* ISO C Standard:  7.16  Boolean type and values  <stdbool.h> */
 250#if (defined __digital__ && defined __unix__)
 251/* old system without (proper) C99 support */
 252# define bool smalluint
 253#else
 254/* modern system, so use it */
 255# include <stdbool.h>
 256#endif
 257
 258
 259/*----- Kernel versioning ------------------------------------*/
 260
 261#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))
 262
 263
 264/* ---- Miscellaneous --------------------------------------- */
 265
 266#if defined __GLIBC__ \
 267 || defined __UCLIBC__ \
 268 || defined __dietlibc__ \
 269 || defined __BIONIC__ \
 270 || defined _NEWLIB_VERSION
 271# include <features.h>
 272#endif
 273
 274/* Define bb_setpgrp */
 275#if defined(__digital__) && defined(__unix__)
 276/* use legacy setpgrp(pid_t, pid_t) for now.  move to platform.c */
 277# define bb_setpgrp() do { pid_t __me = getpid(); setpgrp(__me, __me); } while (0)
 278#else
 279# define bb_setpgrp() setpgrp()
 280#endif
 281
 282/* fdprintf is more readable, we used it before dprintf was standardized */
 283#include <unistd.h>
 284#define fdprintf dprintf
 285
 286/* Useful for defeating gcc's alignment of "char message[]"-like data */
 287#if 1 /* if needed: !defined(arch1) && !defined(arch2) */
 288# define ALIGN1 __attribute__((aligned(1)))
 289# define ALIGN2 __attribute__((aligned(2)))
 290# define ALIGN4 __attribute__((aligned(4)))
 291#else
 292/* Arches which MUST have 2 or 4 byte alignment for everything are here */
 293# define ALIGN1
 294# define ALIGN2
 295# define ALIGN4
 296#endif
 297
 298/*
 299 * For 0.9.29 and svn, __ARCH_USE_MMU__ indicates no-mmu reliably.
 300 * For earlier versions there is no reliable way to check if we are building
 301 * for a mmu-less system.
 302 */
 303#if ENABLE_NOMMU || \
 304    (defined __UCLIBC__ && __UCLIBC_MAJOR__ >= 0 && __UCLIBC_MINOR__ >= 9 && \
 305    __UCLIBC_SUBLEVEL__ > 28 && !defined __ARCH_USE_MMU__)
 306# define BB_MMU 0
 307# define USE_FOR_NOMMU(...) __VA_ARGS__
 308# define USE_FOR_MMU(...)
 309#else
 310# define BB_MMU 1
 311# define USE_FOR_NOMMU(...)
 312# define USE_FOR_MMU(...) __VA_ARGS__
 313#endif
 314
 315#if defined(__digital__) && defined(__unix__)
 316# include <standards.h>
 317# include <inttypes.h>
 318# define PRIu32 "u"
 319# if !defined ADJ_OFFSET_SINGLESHOT && defined MOD_CLKA && defined MOD_OFFSET
 320#  define ADJ_OFFSET_SINGLESHOT (MOD_CLKA | MOD_OFFSET)
 321# endif
 322# if !defined ADJ_FREQUENCY && defined MOD_FREQUENCY
 323#  define ADJ_FREQUENCY MOD_FREQUENCY
 324# endif
 325# if !defined ADJ_TIMECONST && defined MOD_TIMECONST
 326#  define ADJ_TIMECONST MOD_TIMECONST
 327# endif
 328# if !defined ADJ_TICK && defined MOD_CLKB
 329#  define ADJ_TICK MOD_CLKB
 330# endif
 331#endif
 332
 333#if defined(__CYGWIN__)
 334# define MAXSYMLINKS SYMLOOP_MAX
 335#endif
 336
 337
 338/* ---- Who misses what? ------------------------------------ */
 339
 340/* Assume all these functions and header files exist by default.
 341 * Platforms where it is not true will #undef them below.
 342 */
 343#define HAVE_CLEARENV 1
 344#define HAVE_FDATASYNC 1
 345#define HAVE_DPRINTF 1
 346#define HAVE_MEMRCHR 1
 347#define HAVE_MKDTEMP 1
 348#define HAVE_PTSNAME_R 1
 349#define HAVE_SETBIT 1
 350#define HAVE_SIGHANDLER_T 1
 351#define HAVE_STPCPY 1
 352#define HAVE_STRCASESTR 1
 353#define HAVE_STRCHRNUL 1
 354#define HAVE_STRSEP 1
 355#define HAVE_STRSIGNAL 1
 356#define HAVE_STRVERSCMP 1
 357#define HAVE_VASPRINTF 1
 358#define HAVE_UNLOCKED_STDIO 1
 359#define HAVE_UNLOCKED_LINE_OPS 1
 360#define HAVE_GETLINE 1
 361#define HAVE_XTABS 1
 362#define HAVE_MNTENT_H 1
 363#define HAVE_NET_ETHERNET_H 1
 364#define HAVE_SYS_STATFS_H 1
 365
 366#if defined(__UCLIBC_MAJOR__)
 367# if __UCLIBC_MAJOR__ == 0 \
 368  && (   __UCLIBC_MINOR__ < 9 \
 369     || (__UCLIBC_MINOR__ == 9 && __UCLIBC_SUBLEVEL__ < 31) \
 370     )
 371#  undef HAVE_STRVERSCMP
 372# endif
 373#endif
 374
 375#if defined(__dietlibc__)
 376# undef HAVE_STRCHRNUL
 377#endif
 378
 379#if defined(__WATCOMC__)
 380# undef HAVE_DPRINTF
 381# undef HAVE_GETLINE
 382# undef HAVE_MEMRCHR
 383# undef HAVE_MKDTEMP
 384# undef HAVE_SETBIT
 385# undef HAVE_STPCPY
 386# undef HAVE_STRCASESTR
 387# undef HAVE_STRCHRNUL
 388# undef HAVE_STRSEP
 389# undef HAVE_STRSIGNAL
 390# undef HAVE_STRVERSCMP
 391# undef HAVE_VASPRINTF
 392# undef HAVE_UNLOCKED_STDIO
 393# undef HAVE_UNLOCKED_LINE_OPS
 394# undef HAVE_NET_ETHERNET_H
 395#endif
 396
 397#if defined(__CYGWIN__)
 398# undef HAVE_CLEARENV
 399# undef HAVE_FDPRINTF
 400# undef HAVE_MEMRCHR
 401# undef HAVE_PTSNAME_R
 402# undef HAVE_STRVERSCMP
 403# undef HAVE_UNLOCKED_LINE_OPS
 404#endif
 405
 406/* These BSD-derived OSes share many similarities */
 407#if (defined __digital__ && defined __unix__) \
 408 || defined __APPLE__ \
 409 || defined __FreeBSD__ || defined __OpenBSD__ || defined __NetBSD__
 410# undef HAVE_CLEARENV
 411# undef HAVE_FDATASYNC
 412# undef HAVE_GETLINE
 413# undef HAVE_MNTENT_H
 414# undef HAVE_PTSNAME_R
 415# undef HAVE_SYS_STATFS_H
 416# undef HAVE_SIGHANDLER_T
 417# undef HAVE_STRVERSCMP
 418# undef HAVE_XTABS
 419# undef HAVE_DPRINTF
 420# undef HAVE_UNLOCKED_STDIO
 421# undef HAVE_UNLOCKED_LINE_OPS
 422#endif
 423
 424#if defined(__FreeBSD__)
 425# undef HAVE_STRCHRNUL
 426#endif
 427
 428#if defined(__NetBSD__)
 429# define HAVE_GETLINE 1  /* Recent NetBSD versions have getline() */
 430#endif
 431
 432#if defined(__digital__) && defined(__unix__)
 433# undef HAVE_STPCPY
 434#endif
 435
 436#if defined(ANDROID)
 437# undef HAVE_DPRINTF
 438# undef HAVE_GETLINE
 439# undef HAVE_STPCPY
 440# undef HAVE_STRCHRNUL
 441# undef HAVE_STRVERSCMP
 442# undef HAVE_UNLOCKED_LINE_OPS
 443# undef HAVE_NET_ETHERNET_H
 444#endif
 445
 446/*
 447 * Now, define prototypes for all the functions defined in platform.c
 448 * These must come after all the HAVE_* macros are defined (or not)
 449 */
 450
 451#ifndef HAVE_DPRINTF
 452extern int dprintf(int fd, const char *format, ...);
 453#endif
 454
 455#ifndef HAVE_MEMRCHR
 456extern void *memrchr(const void *s, int c, size_t n) FAST_FUNC;
 457#endif
 458
 459#ifndef HAVE_MKDTEMP
 460extern char *mkdtemp(char *template) FAST_FUNC;
 461#endif
 462
 463#ifndef HAVE_SETBIT
 464# define setbit(a, b)  ((a)[(b) >> 3] |= 1 << ((b) & 7))
 465# define clrbit(a, b)  ((a)[(b) >> 3] &= ~(1 << ((b) & 7)))
 466#endif
 467
 468#ifndef HAVE_SIGHANDLER_T
 469typedef void (*sighandler_t)(int);
 470#endif
 471
 472#ifndef HAVE_STPCPY
 473extern char *stpcpy(char *p, const char *to_add) FAST_FUNC;
 474#endif
 475
 476#ifndef HAVE_STRCASESTR
 477extern char *strcasestr(const char *s, const char *pattern) FAST_FUNC;
 478#endif
 479
 480#ifndef HAVE_STRCHRNUL
 481extern char *strchrnul(const char *s, int c) FAST_FUNC;
 482#endif
 483
 484#ifndef HAVE_STRSEP
 485extern char *strsep(char **stringp, const char *delim) FAST_FUNC;
 486#endif
 487
 488#ifndef HAVE_STRSIGNAL
 489/* Not exactly the same: instead of "Stopped" it shows "STOP" etc */
 490# define strsignal(sig) get_signame(sig)
 491#endif
 492
 493#ifndef HAVE_VASPRINTF
 494extern int vasprintf(char **string_ptr, const char *format, va_list p) FAST_FUNC;
 495#endif
 496
 497#ifndef HAVE_GETLINE
 498# include <stdio.h> /* for FILE */
 499# include <sys/types.h> /* size_t */
 500extern ssize_t getline(char **lineptr, size_t *n, FILE *stream) FAST_FUNC;
 501#endif
 502
 503#endif
 504