src/system.h

   1 /* system.h -- system-independent miscellaneous defines.
   2
   3    Copyright (C) 2022 Sergey Sushilin <sergeysushilin@protonmail.com>
   4
   5    This file is part of Build.
   6
   7    Build is free software: you can redistribute it and/or
   8    modify it under the terms of either the GNU General Public License
   9    as published by the Free Software Foundation;
  10    either version 2 of the License, or version 3 of the License,
  11    or both in parallel, as here.
  12
  13    Build is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16    General Public License for more details.
  17
  18    You should have received copies of the GNU General Public License
  19    version 2 and 3 along with this program.
  20    If not, see http://www.gnu.org/licenses/.  */
  21
  22 #pragma once
  23
  24 #if !defined (_WIN32) && !defined (_POSIX_C_SOURCE)
  25 # error unsupported host.
  26 #endif
  27
  28 #define bool  _Bool
  29 #define true  (bool) +1u
  30 #define false (bool) +0u
  31
  32 #define alignas(alignment)  _Alignas (alignment)
  33 #define alignof(expression) _Alignof (expression)
  34
  35 #if !defined (static_assert)
  36 # define static_assert _Static_assert
  37 #endif
  38
  39 #ifdef _WIN32
  40 # define PRIuSIZE "%Iu"
  41 #else
  42 # define PRIuSIZE "%zu"
  43 #endif
  44
  45 #ifdef _WIN32
  46 # define file_offset_t   __int64
  47 # define file_set_offset _fseeki64
  48 # define file_get_offset _ftelli64
  49 #else
  50 # include <sys/types.h>
  51 # define file_offset_t   off_t
  52 # define file_set_offset fseeko
  53 # define file_get_offset ftello
  54 #endif
  55
  56 #ifdef _WIN32
  57 # include <windows.h>
  58 #endif
  59
  60 #if (defined (__i386) || defined (__amd64) || defined (__powerpc__)) && defined (__GNUC__)
  61 # if defined (__clang__)
  62 #  define HAVE_ATOMIC 1
  63 # endif
  64 # if defined (__GLIBC__) && defined (__GLIBC_PREREQ)
  65 #  if (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC__ >= 1)) && __GLIBC_PREREQ (2, 6)
  66 #   define HAVE_ATOMIC 1
  67 #  endif
  68 # endif
  69 #endif
  70
  71 #if HAVE_ATOMIC || defined (__TINYC__)
  72 # include <stdatomic.h>
  73
  74 # define atomic_exchange_acquire(object, value) \
  75   atomic_exchange_explicit ((object), (value), memory_order_acquire)
  76
  77 # define atomic_load_relaxed(object) \
  78   atomic_load_explicit ((object), memory_order_relaxed)
  79
  80 # define atomic_store_release(object, value) \
  81   atomic_store_explicit ((object), (value), memory_order_release)
  82
  83 //# define atomic _Atomic
  84 #elif defined (_WIN32)
  85 # define atomic_init(object, value)             \
  86   do                                            \
  87     {                                           \
  88       *(object) = (value);                      \
  89     }                                           \
  90   while (0)
  91
  92 #define atomic_store(object, value) \
  93   InterlockedExchange (object, value)
  94
  95 #define atomic_load(object) \
  96   InterlockedOr (object, 0)
  97
  98 # define atomic_increment(object) \
  99   InterlockedIncrement (object)
 100
 101 # define atomic_decrement(object) \
 102   InterlockedDecrement (object)
 103
 104 # define atomic_exchange(object, value) \
 105   InterlockedExchange ((object), (value))
 106
 107 # define atomic_compare_exchange(object, value, desired) \
 108   InterlockedCompareExchange ((object), (value), (desired))
 109
 110 # define atomic_compare_exchange_weak(object, value, desired) \
 111   atomic_compare_exchange (object, value, desired)
 112
 113 # define atomic_exchange_acquire(object, value) \
 114   atomic_exchange ((object), (value))
 115
 116 # define atomic_load_relaxed(object) \
 117   atomic_load (object)
 118
 119 # define atomic_store_release(object, value) \
 120   atomic_store ((object), (value))
 121
 122 typedef LONG atomic_size_t;
 123 typedef LONG atomic_bool;
 124 #else
 125 # error "Unable to determine atomic operations for your platform"
 126 #endif
 127
 128 /* Does the __typeof__ keyword work?  This could be done by
 129    'configure', but for now it's easier to do it by hand.  */
 130 #if __GNUC__ >= 2 \
 131  || (__clang_major__ >= 4) \
 132  || (__IBMC__ >= 1210 && defined (__IBM__TYPEOF__)) \
 133  || (__SUNPRO_C >= 0x5110 && !__STDC__) \
 134  || defined (__TINYC__)
 135 # define HAVE___TYPEOF__ 1
 136 #else
 137 # define HAVE___TYPEOF__ 0
 138 #endif
 139
 140 #include <stdint.h>
 141
 142 /* To check alignment gcc has an appropriate operator.
 143    Other compilers do not.  */
 144 #if __GNUC__ >= 2 && !defined (__PCC__)
 145 # define pointer_aligned(pointer, type) \
 146   ((uintptr_t) (pointer) % __alignof__ (type) == 0)
 147 #else
 148 # define pointer_aligned(pointer, type) \
 149   ((uintptr_t) (pointer) % sizeof (type) == 0)
 150 #endif
 151
 152 /* Used for suppressing warning when we know what we are doing.  */
 153 #define pointer_unqualify(pointer) ((void *) (uintptr_t) (pointer))
 154
 155 #define BARF_IF_FAIL(e) (sizeof (char [1 - 2 * (!(e) ? 1 : 0)]) - 1)
 156
 157 #if (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 1) \
 158  || defined(__clang__) || defined(__PCC__) || defined(__TINYC__)) \
 159  && HAVE___TYPEOF__
 160 # define countof(array) \
 161   (sizeof (array) / sizeof ((array)[0]) \
 162    + BARF_IF_FAIL (!__builtin_types_compatible_p (__typeof__ (array), \
 163                                                   __typeof__ (&array[0]))))
 164
 165 /* Are two types/variables the same type (ignoring qualifiers)? */
 166 # define __same_type(a, b) __builtin_types_compatible_p (typeof (a), typeof (b))
 167
 168 /**
 169  * container_of - cast a member of a structure out to the containing structure
 170  * @ptr:        the pointer to the member.
 171  * @type:       the type of the container struct this is embedded in.
 172  * @member:     the name of the member within the struct.
 173  *
 174  * WARNING: any const qualifier of @ptr is lost.
 175  */
 176 # define container_of(ptr, type, member)                                \
 177   __extension__                                                         \
 178   ({                                                                    \
 179     void *__member_pointer = (void *) (ptr);                            \
 180     static_assert (__same_type (*(ptr), ((type *) 0)->member)           \
 181                 || __same_type (*(ptr), void),                          \
 182                    "pointer type mismatch in container_of()");          \
 183     ((type *) ((char *) __member_pointer - offsetof (type, member)));   \
 184   })
 185 #else
 186 # define countof(array) (sizeof (array) / sizeof ((array)[0]))
 187 # define container_of(ptr, type, member) \
 188   ((type *) ((char *) (ptr) - offsetof (type, member)))
 189 #endif
 190
 191 /*
 192  * Optional: only supported since gcc >= 14
 193  * Optional: only supported since clang >= 17
 194  *
 195  *   gcc: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108896
 196  * clang: https://reviews.llvm.org/D148381
 197  */
 198 #if (defined (__GNUC__) && __GNUC__ >= 14) || (defined (__clang__) && __clang_major__ >= 17)
 199 # define counted_by(member) __attribute__ ((__element_count__ (#member)))
 200 #else
 201 # define counted_by(member)
 202 #endif
 203
 204 #define STRLITEQ(s1, s2) (strncmp (s1, s2, countof (s2)) == 0)
 205
 206 /* __builtin_expect(CONDITION, EXPECTED_VALUE) evaluates to CONDITION,
 207    but notifies the compiler that the most likely value of CONDITION
 208    is EXPECTED_VALUE.  */
 209 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
 210 # define LIKELY(condition)   __builtin_expect (!!(condition), true)
 211 # define UNLIKELY(condition) __builtin_expect (!!(condition), false)
 212 #else
 213 # define LIKELY(condition)   (!!(condition))
 214 # define UNLIKELY(condition) (!!(condition))
 215 #endif
 216
 217 //TODO
 218 #ifdef _WIN32
 219 # undef PURE
 220 # undef CONST
 221 #endif
 222
 223 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 95)
 224 # define CONST __attribute__ ((__const__))
 225 #else
 226 # define CONST
 227 #endif
 228
 229 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
 230 # define PURE __attribute__ ((__pure__))
 231 #else
 232 # define PURE
 233 #endif
 234
 235 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 3) || defined (__clang__)
 236 # define NONNULL(...) __attribute__ ((__nonnull__ (__VA_ARGS__)))
 237 #else
 238 # define NONNULL(...)
 239 #endif
 240
 241 /* Warn about unused results of certain
 242    function calls which can lead to problems.  */
 243 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
 244 # define NODISCARD __attribute__ ((__warn_unused_result__))
 245 #else
 246 # define NODISCARD
 247 #endif
 248
 249 #if __GNUC__ >= 7
 250 # define FALLTHROUGH __attribute__ ((__fallthrough__))
 251 #else
 252 # define FALLTHROUGH do { } while (0)
 253 #endif
 254
 255 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 7)
 256 # define UNUSED __attribute__ ((__unused__))
 257 #else
 258 # define UNUSED
 259 #endif
 260
 261 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 5)
 262 # define FORMAT(type, p1, p2) __attribute__ ((__format__ (type, p1, p2)))
 263 #else
 264 # define FORMAT(type, p1, p2)
 265 #endif
 266
 267 #if (defined (_MSC_VER) && _MSC_VER >= 1200) || defined (__CYGWIN__)
 268 # define NORETURN __declspec (noreturn)
 269 #elif (__GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 8)) || defined (__clang__)
 270 # define NORETURN __attribute__ ((__noreturn__))
 271 #else
 272 # define NORETURN _Noreturn
 273 #endif
 274
 275 /* Designates a 1-based positional argument ref-index of pointer type
 276    that can be used to access size-index elements of the pointed-to
 277    array according to access mode, or at least one element when
 278    size-index is not provided:
 279      access (access-mode, <ref-index> [, <size-index>])  */
 280 #if __GNUC__ >= 10
 281 # define ACCESS_read_only(...) \
 282   __attribute__ ((__access__ (__read_only__, __VA_ARGS__)))
 283 # define ACCESS_write_only(...) \
 284   __attribute__ ((__access__ (__write_only__, __VA_ARGS__)))
 285 # define ACCESS_read_write(...) \
 286   __attribute__ ((__access__ (__read_write__, __VA_ARGS__)))
 287 #else
 288 # define ACCESS_read_only(...)
 289 # define ACCESS_write_only(...)
 290 # define ACCESS_read_write(...)
 291 #endif
 292
 293 #if __GNUC__ >= 11
 294 # define ACCESS_none(...) __attribute__ ((__access__ (__none__, __VA_ARGS__)))
 295 #else
 296 # define ACCESS_none(...)
 297 #endif
 298
 299 #define ACCESS(mode, ...) ACCESS_##mode (__VA_ARGS__)
 300
 301 #if (__GNUC__ >= 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9)) \
 302   && !defined(__PCC__)
 303 # define RETURNS_NONNULL __attribute__ ((__returns_nonnull__))
 304 #else
 305 # define RETURNS_NONNULL
 306 #endif
 307
 308 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 7)
 309 # define PACKED __attribute__ ((__packed__))
 310 #else
 311 # define PACKED
 312 #endif
 313
 314 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
 315 # define MALLOC __attribute__ ((__malloc__))
 316 #else
 317 # define MALLOC
 318 #endif
 319
 320 #if __GNUC__ >= 11
 321 /* Designates dealloc as a function to call to deallocate objects
 322    allocated by the declared function.  */
 323 # define DEALLOC(dealloc, argno) __attribute__ ((__malloc__ (dealloc, argno)))
 324 #else
 325 # define DEALLOC(dealloc, argno)
 326 #endif
 327
 328 #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
 329 # define ALLOC_SIZE(...) __attribute__ ((__alloc_size__ (__VA_ARGS__)))
 330 #else
 331 # define ALLOC_SIZE(...)
 332 #endif
 333
 334 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
 335 # define ALWAYS_INLINE __attribute__ ((__always_inline__))
 336 #else
 337 # define ALWAYS_INLINE
 338 #endif
 339
 340 /* Warningless cast from const pointer to usual pointer.  */
 341 static inline ALWAYS_INLINE void *
 342 worst_cast (const void *p)
 343 {
 344   union
 345   {
 346     const void *p;
 347     void *q;
 348   } u = { .p = p };
 349
 350   return u.q;
 351 }
 352
 353 #define pragma(x) _Pragma (#x)
 354 #define TODO(x) pragma (message ("TODO: " #x))
 355
 356 /* Support for flexible arrays.
 357    Usage:
 358
 359    struct foo
 360    {
 361      size_t size;
 362      char bar[__flexible_array__];
 363    };
 364
 365    stuct foo *
 366    baz (size_t size)
 367    {
 368      return malloc (sizeof (struct foo) - __flexible_array_extra_size__ + size);
 369    } */
 370 #if defined (__STDC_VERSION__) && __STDC_VERSION__ > 199901L && !defined (__HP_cc)
 371 # define __flexible_array__
 372 # define __flexible_array_extra_size__ 0
 373 #elif __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96) || defined (__clang__)
 374 /* GCC 2.97 and clang support C99 flexible array members as an extension,
 375    even when in C89 mode or compiling C++ (any version).  */
 376 # define __flexible_array__
 377 # define __flexible_array_extra_size__ 0
 378 #elif defined (__GNUC__)
 379 /* Pre-2.97 GCC did not support C99 flexible arrays but did have
 380    an equivalent extension with slightly different notation.  */
 381 # define __flexible_array__ 0
 382 # define __flexible_array_extra_size__ 1
 383 #else
 384 /* Some other non-C99 compiler.  Approximate with [1].  */
 385 # define __flexible_array__ 1
 386 # define __flexible_array_extra_size__ 1
 387 #endif
 388
 389 /* How Build quotes filenames, to minimize use of outer quotes,
 390    but also provide better support for copy and paste when used.  */
 391 #include "libquote/quote.h"
 392 #include "libquote/quotearg.h"
 393
 394 /* Use these to shell quote only when necessary,
 395    when the quoted item is already delimited with colons.  */
 396 #define quotef(qs, arg) \
 397   quotearg_n_style_colon (qs, 0, quoting_style_shell_escape, arg)
 398 #define quotef_n(qs, n, arg) \
 399   quotearg_n_style_colon (qs, n, quoting_style_shell_escape, arg)
 400
 401 /* Use these when there are spaces around the file name,
 402    in the error message.  */
 403 #define quoteaf(qs, arg) \
 404   quotearg_style (qs, quoting_style_shell_escape_always, arg)
 405 #define quoteaf_n(qs, n, arg) \
 406   quotearg_n_style (qs, n, quoting_style_shell_escape_always, arg)
 407
 408 #if ENABLE_NLS
 409 /* Get declarations of GNU message catalog functions.  */
 410 # include <libintl.h>
 411 #else
 412 /* Disabled NLS.
 413    The casts to 'const char *' serve the purpose of producing warnings
 414    for invalid uses of the value returned from these functions.  */
 415 # define gettext(msgid) ((const char *) (msgid))
 416 # define ngettext(msgid1, msgid2, n) \
 417   ((n) == 1 ? (const char *) (msgid1) : (const char *) (msgid2))
 418 # define textdomain(domainname) \
 419   ((const char *) (domainname))
 420 # define bindtextdomain(domainname, dirname) \
 421   ((void) (domainname), (const char *) (dirname))
 422 # ifndef PACKAGE
 423 #  define PACKAGE   ""
 424 # endif
 425 # ifndef LOCALEDIR
 426 #  define LOCALEDIR ""
 427 # endif
 428 #endif
 429
 430 /* A pseudo function call that serves as a marker for the automated
 431    extraction of messages, but does not call gettext().  The run-time
 432    translation is done at a different place in the code.
 433    The argument, MSGID, should be a literal string.  Concatenated strings
 434    and other string expressions will not work.
 435    The macro's expansion is not parenthesized, so that it is suitable as
 436    initializer for static 'char[]' or 'const char[]' variables.  */
 437 #define gettext_noop(msgid) msgid
 438
 439 #define  _(msgid)             gettext (msgid)
 440 #define N_(msgid)             gettext_noop (msgid)
 441 #define S_(msgid1, msgid2, n) ngettext (msgid1, msgid2, n)