include/compiler.h

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 2007-2017 The NASM Authors - All Rights Reserved
   4  *   See the file AUTHORS included with the NASM distribution for
   5  *   the specific copyright holders.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following
   9  *   conditions are met:
  10  *
  11  *   * Redistributions of source code must retain the above copyright
  12  *     notice, this list of conditions and the following disclaimer.
  13  *   * Redistributions in binary form must reproduce the above
  14  *     copyright notice, this list of conditions and the following
  15  *     disclaimer in the documentation and/or other materials provided
  16  *     with the distribution.
  17  *
  18  *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  19  *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  20  *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  21  *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  22  *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  23  *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  25  *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  26  *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  28  *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  29  *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
  30  *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31  *
  32  * ----------------------------------------------------------------------- */
  33
  34 /*
  35  * compiler.h
  36  *
  37  * Compiler-specific macros for NASM.  Feel free to add support for
  38  * other compilers in here.
  39  *
  40  * This header file should be included before any other header.
  41  */
  42
  43 #ifndef NASM_COMPILER_H
  44 #define NASM_COMPILER_H 1
  45
  46 /*
  47  * At least DJGPP and Cygwin have broken header files if __STRICT_ANSI__
  48  * is defined.
  49  */
  50 #ifdef __GNUC__
  51 # undef __STRICT_ANSI__
  52 #endif
  53
  54 /* On Microsoft platforms we support multibyte character sets in filenames */
  55 #define _MBCS 1
  56
  57 #ifdef HAVE_CONFIG_H
  58 # include "config/config.h"
  59 #elif defined(_MSC_VER) && (_MSC_VER >= 1310)
  60 # include "config/msvc.h"
  61 #elif defined(__WATCOMC__)
  62 # include "config/watcom.h"
  63 #else
  64 # include "config/unknown.h"
  65 #endif /* Configuration file */
  66
  67 /* This is required to get the standard <inttypes.h> macros when compiling
  68    with a C++ compiler.  This must be defined *before* <inttypes.h> is
  69    included, directly or indirectly. */
  70 #define __STDC_CONSTANT_MACROS  1
  71 #define __STDC_LIMIT_MACROS     1
  72 #define __STDC_FORMAT_MACROS    1
  73
  74 #ifdef HAVE_INTTYPES_H
  75 # include <inttypes.h>
  76 #else
  77 # include "nasmint.h"
  78 #endif
  79
  80 #include <assert.h>
  81 #include <stddef.h>
  82 #include <stdarg.h>
  83 #include <stdio.h>
  84 #include <limits.h>
  85
  86 #ifdef HAVE_SYS_TYPES_H
  87 # include <sys/types.h>
  88 #endif
  89
  90 #ifdef HAVE_ENDIAN_H
  91 # include <endian.h>
  92 #elif defined(HAVE_SYS_ENDIAN_H)
  93 # include <sys/endian.h>
  94 #elif defined(HAVE_MACHINE_ENDIAN_H)
  95 # include <machine/endian.h>
  96 #endif
  97
  98 /*
  99  * If we have BYTE_ORDER defined, or the compiler provides
 100  * __BIG_ENDIAN__ or __LITTLE_ENDIAN__, trust it over what autoconf
 101  * came up with, especially since autoconf obviously can't figure
 102  * things out for a universal compiler.
 103  */
 104 #if defined(__BIG_ENDIAN__) && !defined(__LITTLE_ENDIAN__)
 105 # undef WORDS_LITTLEENDIAN
 106 # undef WORDS_BIGENDIAN
 107 # define WORDS_BIGENDIAN 1
 108 #elif defined(__LITTLE_ENDIAN__) && !defined(__BIG_ENDIAN__)
 109 # undef WORDS_LITTLEENDIAN
 110 # undef WORDS_BIGENDIAN
 111 # define WORDS_LITTLEENDIAN 1
 112 #elif defined(BYTE_ORDER) && defined(LITTLE_ENDIAN) && defined(BIG_ENDIAN)
 113 # undef WORDS_LITTLEENDIAN
 114 # undef WORDS_BIGENDIAN
 115 # if BYTE_ORDER == LITTLE_ENDIAN
 116 #  define WORDS_LITTLEENDIAN 1
 117 # elif BYTE_ORDER == BIG_ENDIAN
 118 #  define WORDS_BIGENDIAN 1
 119 # endif
 120 #endif
 121
 122 /*
 123  * Define this to 1 for faster performance if this is a littleendian
 124  * platform *and* it can do arbitrary unaligned memory references.  It
 125  * is safe to leave it defined to 0 even if that is true.
 126  */
 127 #if defined(__386__) || defined(__i386__) || defined(__x86_64__) \
 128     || defined(_M_IX86) || defined(_M_X64)
 129 # define X86_MEMORY 1
 130 # undef WORDS_BIGENDIAN
 131 # undef WORDS_LITTLEENDIAN
 132 # define WORDS_LITTLEENDIAN 1
 133 #else
 134 # define X86_MEMORY 0
 135 #endif
 136
 137 /* Some versions of MSVC have these only with underscores in front */
 138 #ifndef HAVE_SNPRINTF
 139 # ifdef HAVE__SNPRINTF
 140 #  define snprintf _snprintf
 141 # else
 142 int snprintf(char *, size_t, const char *, ...);
 143 # endif
 144 #endif
 145
 146 #ifndef HAVE_VSNPRINTF
 147 # ifdef HAVE__VSNPRINTF
 148 #  define vsnprintf _vsnprintf
 149 # else
 150 int vsnprintf(char *, size_t, const char *, va_list);
 151 # endif
 152 #endif
 153
 154 #if !defined(HAVE_STRLCPY) || !HAVE_DECL_STRLCPY
 155 size_t strlcpy(char *, const char *, size_t);
 156 #endif
 157
 158 #if !defined(HAVE_STRCHRNUL) || !HAVE_DECL_STRCHRNUL
 159 char *strrchrnul(const char *, int);
 160 #endif
 161
 162 #ifndef __cplusplus             /* C++ has false, true, bool as keywords */
 163 # ifdef HAVE_STDBOOL_H
 164 #  include <stdbool.h>
 165 # elif defined(HAVE__BOOL)
 166 #  typedef _Bool bool
 167 #  define false 0
 168 #  define true 1
 169 # else
 170 /* This is sort of dangerous, since casts will behave different than
 171    casting to the standard boolean type.  Always use !!, not (bool). */
 172 typedef enum bool { false, true } bool;
 173 # endif
 174 #endif
 175
 176 /* Provide a substitute for offsetof() if we don't have one.  This
 177    variant works on most (but not *all*) systems... */
 178 #ifndef offsetof
 179 # define offsetof(t,m) ((size_t)&(((t *)0)->m))
 180 #endif
 181
 182 /* The container_of construct: if p is a pointer to member m of
 183    container class c, then return a pointer to the container of which
 184    *p is a member. */
 185 #ifndef container_of
 186 # define container_of(p, c, m) ((c *)((char *)(p) - offsetof(c,m)))
 187 #endif
 188
 189 /* Some misguided platforms hide the defs for these */
 190 #if defined(HAVE_STRCASECMP) && !HAVE_DECL_STRCASECMP
 191 int strcasecmp(const char *, const char *);
 192 #endif
 193
 194 #if defined(HAVE_STRICMP) && !HAVE_DECL_STRICMP
 195 int stricmp(const char *, const char *);
 196 #endif
 197
 198 #if defined(HAVE_STRNCASECMP) && !HAVE_DECL_STRNCASECMP
 199 int strncasecmp(const char *, const char *, size_t);
 200 #endif
 201
 202 #if defined(HAVE_STRNICMP) && !HAVE_DECL_STRNICMP
 203 int strnicmp(const char *, const char *, size_t);
 204 #endif
 205
 206 #if defined(HAVE_STRSEP) && !HAVE_DECL_STRSEP
 207 char *strsep(char **, const char *);
 208 #endif
 209
 210 #if !HAVE_DECL_STRNLEN
 211 size_t strnlen(const char *s, size_t maxlen);
 212 #endif
 213
 214 /*
 215  * Hack to support external-linkage inline functions
 216  */
 217 #ifndef HAVE_STDC_INLINE
 218 # ifdef __GNUC__
 219 #  ifdef __GNUC_STDC_INLINE__
 220 #   define HAVE_STDC_INLINE
 221 #  else
 222 #   define HAVE_GNU_INLINE
 223 #  endif
 224 # elif defined(__GNUC_GNU_INLINE__)
 225 /* Some other compiler implementing only GNU inline semantics? */
 226 #   define HAVE_GNU_INLINE
 227 # elif defined(__STDC_VERSION__)
 228 #  if __STDC_VERSION__ >= 199901L
 229 #   define HAVE_STDC_INLINE
 230 #  endif
 231 # endif
 232 #endif
 233
 234 #ifdef HAVE_STDC_INLINE
 235 # define extern_inline inline
 236 #elif defined(HAVE_GNU_INLINE)
 237 # define extern_inline extern inline
 238 # define inline_prototypes
 239 #else
 240 # define inline_prototypes
 241 #endif
 242
 243 /*
 244  * Fallthrough handling.
 245  */
 246 #ifdef HAVE_FALLTHROUGH_ATTRIBUTE
 247 # define fallthrough() __attribute__((fallthrough))
 248 #else
 249 # define fallthrough() /* fall through */
 250 #endif
 251
 252 /*
 253  * Hints to the compiler that a particular branch of code is more or
 254  * less likely to be taken.
 255  */
 256 #if HAVE___BUILTIN_EXPECT
 257 # define likely(x)      __builtin_expect(!!(x), 1)
 258 # define unlikely(x)    __builtin_expect(!!(x), 0)
 259 #else
 260 # define likely(x)      (!!(x))
 261 # define unlikely(x)    (!!(x))
 262 #endif
 263
 264 /*
 265  * Hints about malloc-like functions that never return NULL
 266  */
 267 #ifdef HAVE_FUNC_ATTRIBUTE_RETURNS_NONNULL
 268 # define never_null __attribute__((returns_nonnull))
 269 #else
 270 # define never_null
 271 #endif
 272
 273 #ifdef HAVE_FUNC_ATTRIBUTE_MALLOC
 274 # define safe_alloc never_null __attribute__((malloc))
 275 #else
 276 # define safe_alloc
 277 #endif
 278
 279 #ifdef HAVE_FUNC_ATTRIBUTE_ALLOC_SIZE
 280 # define safe_malloc(s) safe_alloc __attribute__((alloc_size(s)))
 281 # define safe_malloc2(s1,s2) safe_alloc __attribute__((alloc_size(s1,s2)))
 282 # define safe_realloc(s) never_null __attribute__((alloc_size(s)))
 283 #else
 284 # define safe_malloc(s) safe_alloc
 285 # define safe_malloc2(s1,s2) safe_alloc
 286 # define safe_realloc(s) never_null
 287 #endif
 288
 289 /*
 290  * How to tell the compiler that a function doesn't return
 291  */
 292 #ifdef HAVE_STDNORETURN_H
 293 # include <stdnoreturn.h>
 294 # define no_return noreturn void
 295 #elif defined(HAVE_FUNC_ATTRIBUTE_NORETURN)
 296 # define no_return void __attribute__((noreturn))
 297 #elif defined(_MSC_VER)
 298 # define no_return __declspec(noreturn) void
 299 #else
 300 # define no_return void
 301 #endif
 302
 303 /*
 304  * How to tell the compiler that a function is unlikely to be executed.
 305  * This differs from unlikely() in that it is applied to a function call,
 306  * not a boolean condition.
 307  */
 308 #ifdef HAVE_FUNC_ATTRIBUTE_COLD
 309 # define unlikely_func __attribute__((cold))
 310 #else
 311 # define unlikely_func
 312 #endif
 313
 314 /*
 315  * A fatal function is both unlikely and no_return
 316  */
 317 #define fatal_func no_return unlikely_func
 318
 319 /*
 320  * How to tell the compiler that a function takes a printf-like string
 321  */
 322 #ifdef HAVE_FUNC_ATTRIBUTE_FORMAT
 323 # define printf_func(fmt, list) __attribute__((format(printf, fmt, list)))
 324 #else
 325 # define printf_func(fmt, list)
 326 #endif
 327
 328 /*
 329  * How to tell the compiler that a function is pure arithmetic
 330  */
 331 #ifdef HAVE_FUNC_ATTRIBUTE_CONST
 332 # define const_func __attribute__((const))
 333 #else
 334 # define const_func
 335 #endif
 336
 337 /*
 338  * This function has no side effects, but depends on its arguments,
 339  * memory pointed to by its arguments, or global variables.
 340  * NOTE: functions that return a value by modifying memory pointed to
 341  * by a pointer argument are *NOT* considered pure.
 342  */
 343 #ifdef HAVE_FUNC_ATTRIBUTE_PURE
 344 # define pure_func __attribute__((pure))
 345 #else
 346 # define pure_func
 347 #endif
 348
 349 /* Determine probabilistically if something is a compile-time constant */
 350 #ifdef HAVE___BUILTIN_CONSTANT_P
 351 # define is_constant(x) __builtin_constant_p(x)
 352 #else
 353 # define is_constant(x) false
 354 #endif
 355
 356 /* Watcom doesn't handle switch statements with 64-bit types, hack around it */
 357 #ifdef __WATCOMC__
 358 # define BOGUS_CASE 0x76543210
 359
 360 static inline unsigned int watcom_switch_hack(uint64_t x)
 361 {
 362     if (x > (uint64_t)UINT_MAX)
 363         return BOGUS_CASE;
 364     else
 365         return (unsigned int)x;
 366 }
 367
 368 # define switch(x) switch(sizeof(x) > sizeof(unsigned int) \
 369                           ? watcom_switch_hack(x) : (unsigned int)(x))
 370
 371 /* This is to make sure BOGUS_CASE doesn't conflict with anything real... */
 372 # define default case BOGUS_CASE: default
 373 #endif
 374
 375 #endif  /* NASM_COMPILER_H */