timezone/private.h

   1 /* Private header for tzdb code.  */
   2
   3 #ifndef PRIVATE_H
   4
   5 #define PRIVATE_H
   6
   7 /*
   8 ** This file is in the public domain, so clarified as of
   9 ** 1996-06-05 by Arthur David Olson.
  10 */
  11
  12 /*
  13 ** This header is for use ONLY with the time conversion code.
  14 ** There is no guarantee that it will remain unchanged,
  15 ** or that it will remain at all.
  16 ** Do NOT copy it to any system include directory.
  17 ** Thank you!
  18 */
  19
  20 /* PORT_TO_C89 means the code should work even if the underlying
  21    compiler and library support only C89 plus C99's 'long long'
  22    and perhaps a few other extensions to C89.  SUPPORT_C89 means the
  23    tzcode library should support C89 callers in addition to the usual
  24    support for C99-and-later callers; however, C89 support can trigger
  25    latent bugs in C99-and-later callers.  These macros are obsolescent,
  26    and the plan is to remove them along with any code needed only when
  27    they are nonzero.  A good time to do that might be in the year 2029
  28    because RHEL 7 (whose GCC defaults to C89) extended life cycle
  29    support (ELS) is scheduled to end on 2028-06-30.  */
  30 #ifndef PORT_TO_C89
  31 # define PORT_TO_C89 0
  32 #endif
  33 #ifndef SUPPORT_C89
  34 # define SUPPORT_C89 0
  35 #endif
  36
  37 #ifndef __STDC_VERSION__
  38 # define __STDC_VERSION__ 0
  39 #endif
  40
  41 /* Define true, false and bool if they don't work out of the box.  */
  42 #if PORT_TO_C89 && __STDC_VERSION__ < 199901
  43 # define true 1
  44 # define false 0
  45 # define bool int
  46 #elif __STDC_VERSION__ < 202311
  47 # include <stdbool.h>
  48 #endif
  49
  50 #if __STDC_VERSION__ < 202311
  51 # define static_assert(cond) extern int static_assert_check[(cond) ? 1 : -1]
  52 #endif
  53
  54 /*
  55 ** zdump has been made independent of the rest of the time
  56 ** conversion package to increase confidence in the verification it provides.
  57 ** You can use zdump to help in verifying other implementations.
  58 ** To do this, compile with -DUSE_LTZ=0 and link without the tz library.
  59 */
  60 #ifndef USE_LTZ
  61 # define USE_LTZ 1
  62 #endif
  63
  64 /* This string was in the Factory zone through version 2016f.  */
  65 #define GRANDPARENTED   "Local time zone must be set--see zic manual page"
  66
  67 /*
  68 ** Defaults for preprocessor symbols.
  69 ** You can override these in your C compiler options, e.g. '-DHAVE_GETTEXT=1'.
  70 */
  71
  72 #ifndef HAVE_DECL_ASCTIME_R
  73 # define HAVE_DECL_ASCTIME_R 1
  74 #endif
  75
  76 #if !defined HAVE__GENERIC && defined __has_extension
  77 # if !__has_extension(c_generic_selections)
  78 #  define HAVE__GENERIC 0
  79 # endif
  80 #endif
  81 /* _Generic is buggy in pre-4.9 GCC.  */
  82 #if !defined HAVE__GENERIC && defined __GNUC__ && !defined __STRICT_ANSI__
  83 # define HAVE__GENERIC (4 < __GNUC__ + (9 <= __GNUC_MINOR__))
  84 #endif
  85 #ifndef HAVE__GENERIC
  86 # define HAVE__GENERIC (201112 <= __STDC_VERSION__)
  87 #endif
  88
  89 #if !defined HAVE_GETTEXT && defined __has_include
  90 # if __has_include(<libintl.h>)
  91 #  define HAVE_GETTEXT true
  92 # endif
  93 #endif
  94 #ifndef HAVE_GETTEXT
  95 # define HAVE_GETTEXT false
  96 #endif
  97
  98 #ifndef HAVE_INCOMPATIBLE_CTIME_R
  99 # define HAVE_INCOMPATIBLE_CTIME_R 0
 100 #endif
 101
 102 #ifndef HAVE_LINK
 103 # define HAVE_LINK 1
 104 #endif /* !defined HAVE_LINK */
 105
 106 #ifndef HAVE_MALLOC_ERRNO
 107 # define HAVE_MALLOC_ERRNO 1
 108 #endif
 109
 110 #ifndef HAVE_POSIX_DECLS
 111 # define HAVE_POSIX_DECLS 1
 112 #endif
 113
 114 #ifndef HAVE_SETENV
 115 # define HAVE_SETENV 1
 116 #endif
 117
 118 #ifndef HAVE_STRDUP
 119 # define HAVE_STRDUP 1
 120 #endif
 121
 122 #ifndef HAVE_SYMLINK
 123 # define HAVE_SYMLINK 1
 124 #endif /* !defined HAVE_SYMLINK */
 125
 126 #if !defined HAVE_SYS_STAT_H && defined __has_include
 127 # if !__has_include(<sys/stat.h>)
 128 #  define HAVE_SYS_STAT_H false
 129 # endif
 130 #endif
 131 #ifndef HAVE_SYS_STAT_H
 132 # define HAVE_SYS_STAT_H true
 133 #endif
 134
 135 #if !defined HAVE_UNISTD_H && defined __has_include
 136 # if !__has_include(<unistd.h>)
 137 #  define HAVE_UNISTD_H false
 138 # endif
 139 #endif
 140 #ifndef HAVE_UNISTD_H
 141 # define HAVE_UNISTD_H true
 142 #endif
 143
 144 #ifndef NETBSD_INSPIRED
 145 # define NETBSD_INSPIRED 1
 146 #endif
 147
 148 #if HAVE_INCOMPATIBLE_CTIME_R
 149 # define asctime_r _incompatible_asctime_r
 150 # define ctime_r _incompatible_ctime_r
 151 #endif /* HAVE_INCOMPATIBLE_CTIME_R */
 152
 153 /* Enable tm_gmtoff, tm_zone, and environ on GNUish systems.  */
 154 #define _GNU_SOURCE 1
 155 /* Fix asctime_r on Solaris 11.  */
 156 #define _POSIX_PTHREAD_SEMANTICS 1
 157 /* Enable strtoimax on pre-C99 Solaris 11.  */
 158 #define __EXTENSIONS__ 1
 159
 160 /* On GNUish systems where time_t might be 32 or 64 bits, use 64.
 161    On these platforms _FILE_OFFSET_BITS must also be 64; otherwise
 162    setting _TIME_BITS to 64 does not work.  The code does not
 163    otherwise rely on _FILE_OFFSET_BITS being 64, since it does not
 164    use off_t or functions like 'stat' that depend on off_t.  */
 165 #ifndef _FILE_OFFSET_BITS
 166 # define _FILE_OFFSET_BITS 64
 167 #endif
 168 #if !defined _TIME_BITS && _FILE_OFFSET_BITS == 64
 169 # define _TIME_BITS 64
 170 #endif
 171
 172 /*
 173 ** Nested includes
 174 */
 175
 176 /* Avoid clashes with NetBSD by renaming NetBSD's declarations.
 177    If defining the 'timezone' variable, avoid a clash with FreeBSD's
 178    'timezone' function by renaming its declaration.  */
 179 #define localtime_rz sys_localtime_rz
 180 #define mktime_z sys_mktime_z
 181 #define posix2time_z sys_posix2time_z
 182 #define time2posix_z sys_time2posix_z
 183 #if defined USG_COMPAT && USG_COMPAT == 2
 184 # define timezone sys_timezone
 185 #endif
 186 #define timezone_t sys_timezone_t
 187 #define tzalloc sys_tzalloc
 188 #define tzfree sys_tzfree
 189 #include <time.h>
 190 #undef localtime_rz
 191 #undef mktime_z
 192 #undef posix2time_z
 193 #undef time2posix_z
 194 #if defined USG_COMPAT && USG_COMPAT == 2
 195 # undef timezone
 196 #endif
 197 #undef timezone_t
 198 #undef tzalloc
 199 #undef tzfree
 200
 201 #include <stddef.h>
 202 #include <string.h>
 203 #if !PORT_TO_C89
 204 # include <inttypes.h>
 205 #endif
 206 #include <limits.h>     /* for CHAR_BIT et al. */
 207 #include <stdlib.h>
 208
 209 #include <errno.h>
 210
 211 #ifndef EINVAL
 212 # define EINVAL ERANGE
 213 #endif
 214
 215 #ifndef ELOOP
 216 # define ELOOP EINVAL
 217 #endif
 218 #ifndef ENAMETOOLONG
 219 # define ENAMETOOLONG EINVAL
 220 #endif
 221 #ifndef ENOMEM
 222 # define ENOMEM EINVAL
 223 #endif
 224 #ifndef ENOTSUP
 225 # define ENOTSUP EINVAL
 226 #endif
 227 #ifndef EOVERFLOW
 228 # define EOVERFLOW EINVAL
 229 #endif
 230
 231 #if HAVE_GETTEXT
 232 # include <libintl.h>
 233 #endif /* HAVE_GETTEXT */
 234
 235 #if HAVE_UNISTD_H
 236 # include <unistd.h> /* for R_OK, and other POSIX goodness */
 237 #endif /* HAVE_UNISTD_H */
 238
 239 #ifndef HAVE_STRFTIME_L
 240 # if _POSIX_VERSION < 200809
 241 #  define HAVE_STRFTIME_L 0
 242 # else
 243 #  define HAVE_STRFTIME_L 1
 244 # endif
 245 #endif
 246
 247 #ifndef USG_COMPAT
 248 # ifndef _XOPEN_VERSION
 249 #  define USG_COMPAT 0
 250 # else
 251 #  define USG_COMPAT 1
 252 # endif
 253 #endif
 254
 255 #ifndef HAVE_TZNAME
 256 # if _POSIX_VERSION < 198808 && !USG_COMPAT
 257 #  define HAVE_TZNAME 0
 258 # else
 259 #  define HAVE_TZNAME 1
 260 # endif
 261 #endif
 262
 263 #ifndef ALTZONE
 264 # if defined __sun || defined _M_XENIX
 265 #  define ALTZONE 1
 266 # else
 267 #  define ALTZONE 0
 268 # endif
 269 #endif
 270
 271 #ifndef R_OK
 272 # define R_OK 4
 273 #endif /* !defined R_OK */
 274
 275 #if PORT_TO_C89
 276
 277 /*
 278 ** Define HAVE_STDINT_H's default value here, rather than at the
 279 ** start, since __GLIBC__ and INTMAX_MAX's values depend on
 280 ** previously included files.  glibc 2.1 and Solaris 10 and later have
 281 ** stdint.h, even with pre-C99 compilers.
 282 */
 283 #if !defined HAVE_STDINT_H && defined __has_include
 284 # define HAVE_STDINT_H true /* C23 __has_include implies C99 stdint.h.  */
 285 #endif
 286 #ifndef HAVE_STDINT_H
 287 # define HAVE_STDINT_H \
 288    (199901 <= __STDC_VERSION__ \
 289     || 2 < __GLIBC__ + (1 <= __GLIBC_MINOR__) \
 290     || __CYGWIN__ || INTMAX_MAX)
 291 #endif /* !defined HAVE_STDINT_H */
 292
 293 #if HAVE_STDINT_H
 294 # include <stdint.h>
 295 #endif /* !HAVE_STDINT_H */
 296
 297 #ifndef HAVE_INTTYPES_H
 298 # define HAVE_INTTYPES_H HAVE_STDINT_H
 299 #endif
 300 #if HAVE_INTTYPES_H
 301 # include <inttypes.h>
 302 #endif
 303
 304 /* Pre-C99 GCC compilers define __LONG_LONG_MAX__ instead of LLONG_MAX.  */
 305 #if defined __LONG_LONG_MAX__ && !defined __STRICT_ANSI__
 306 # ifndef LLONG_MAX
 307 #  define LLONG_MAX __LONG_LONG_MAX__
 308 # endif
 309 # ifndef LLONG_MIN
 310 #  define LLONG_MIN (-1 - LLONG_MAX)
 311 # endif
 312 # ifndef ULLONG_MAX
 313 #  define ULLONG_MAX (LLONG_MAX * 2ull + 1)
 314 # endif
 315 #endif
 316
 317 #ifndef INT_FAST64_MAX
 318 # if 1 <= LONG_MAX >> 31 >> 31
 319 typedef long int_fast64_t;
 320 #  define INT_FAST64_MIN LONG_MIN
 321 #  define INT_FAST64_MAX LONG_MAX
 322 # else
 323 /* If this fails, compile with -DHAVE_STDINT_H or with a better compiler.  */
 324 typedef long long int_fast64_t;
 325 #  define INT_FAST64_MIN LLONG_MIN
 326 #  define INT_FAST64_MAX LLONG_MAX
 327 # endif
 328 #endif
 329
 330 #ifndef PRIdFAST64
 331 # if INT_FAST64_MAX == LONG_MAX
 332 #  define PRIdFAST64 "ld"
 333 # else
 334 #  define PRIdFAST64 "lld"
 335 # endif
 336 #endif
 337
 338 #ifndef SCNdFAST64
 339 # define SCNdFAST64 PRIdFAST64
 340 #endif
 341
 342 #ifndef INT_FAST32_MAX
 343 # if INT_MAX >> 31 == 0
 344 typedef long int_fast32_t;
 345 #  define INT_FAST32_MAX LONG_MAX
 346 #  define INT_FAST32_MIN LONG_MIN
 347 # else
 348 typedef int int_fast32_t;
 349 #  define INT_FAST32_MAX INT_MAX
 350 #  define INT_FAST32_MIN INT_MIN
 351 # endif
 352 #endif
 353
 354 #ifndef INTMAX_MAX
 355 # ifdef LLONG_MAX
 356 typedef long long intmax_t;
 357 #  ifndef HAVE_STRTOLL
 358 #   define HAVE_STRTOLL true
 359 #  endif
 360 #  if HAVE_STRTOLL
 361 #   define strtoimax strtoll
 362 #  endif
 363 #  define INTMAX_MAX LLONG_MAX
 364 #  define INTMAX_MIN LLONG_MIN
 365 # else
 366 typedef long intmax_t;
 367 #  define INTMAX_MAX LONG_MAX
 368 #  define INTMAX_MIN LONG_MIN
 369 # endif
 370 # ifndef strtoimax
 371 #  define strtoimax strtol
 372 # endif
 373 #endif
 374
 375 #ifndef PRIdMAX
 376 # if INTMAX_MAX == LLONG_MAX
 377 #  define PRIdMAX "lld"
 378 # else
 379 #  define PRIdMAX "ld"
 380 # endif
 381 #endif
 382
 383 #ifndef PTRDIFF_MAX
 384 # define PTRDIFF_MAX MAXVAL(ptrdiff_t, TYPE_BIT(ptrdiff_t))
 385 #endif
 386
 387 #ifndef UINT_FAST32_MAX
 388 typedef unsigned long uint_fast32_t;
 389 #endif
 390
 391 #ifndef UINT_FAST64_MAX
 392 # if 3 <= ULONG_MAX >> 31 >> 31
 393 typedef unsigned long uint_fast64_t;
 394 #  define UINT_FAST64_MAX ULONG_MAX
 395 # else
 396 /* If this fails, compile with -DHAVE_STDINT_H or with a better compiler.  */
 397 typedef unsigned long long uint_fast64_t;
 398 #  define UINT_FAST64_MAX ULLONG_MAX
 399 # endif
 400 #endif
 401
 402 #ifndef UINTMAX_MAX
 403 # ifdef ULLONG_MAX
 404 typedef unsigned long long uintmax_t;
 405 #  define UINTMAX_MAX ULLONG_MAX
 406 # else
 407 typedef unsigned long uintmax_t;
 408 #  define UINTMAX_MAX ULONG_MAX
 409 # endif
 410 #endif
 411
 412 #ifndef PRIuMAX
 413 # ifdef ULLONG_MAX
 414 #  define PRIuMAX "llu"
 415 # else
 416 #  define PRIuMAX "lu"
 417 # endif
 418 #endif
 419
 420 #ifndef SIZE_MAX
 421 # define SIZE_MAX ((size_t) -1)
 422 #endif
 423
 424 #endif /* PORT_TO_C89 */
 425
 426 /* The maximum size of any created object, as a signed integer.
 427    Although the C standard does not outright prohibit larger objects,
 428    behavior is undefined if the result of pointer subtraction does not
 429    fit into ptrdiff_t, and the code assumes in several places that
 430    pointer subtraction works.  As a practical matter it's OK to not
 431    support objects larger than this.  */
 432 #define INDEX_MAX ((ptrdiff_t) min(PTRDIFF_MAX, SIZE_MAX))
 433
 434 /* Support ckd_add, ckd_sub, ckd_mul on C23 or recent-enough GCC-like
 435    hosts, unless compiled with -DHAVE_STDCKDINT_H=0 or with pre-C23 EDG.  */
 436 #if !defined HAVE_STDCKDINT_H && defined __has_include
 437 # if __has_include(<stdckdint.h>)
 438 #  define HAVE_STDCKDINT_H true
 439 # endif
 440 #endif
 441 #ifdef HAVE_STDCKDINT_H
 442 # if HAVE_STDCKDINT_H
 443 #  include <stdckdint.h>
 444 # endif
 445 #elif defined __EDG__
 446 /* Do nothing, to work around EDG bug <https://bugs.gnu.org/53256>.  */
 447 #elif defined __has_builtin
 448 # if __has_builtin(__builtin_add_overflow)
 449 #  define ckd_add(r, a, b) __builtin_add_overflow(a, b, r)
 450 # endif
 451 # if __has_builtin(__builtin_sub_overflow)
 452 #  define ckd_sub(r, a, b) __builtin_sub_overflow(a, b, r)
 453 # endif
 454 # if __has_builtin(__builtin_mul_overflow)
 455 #  define ckd_mul(r, a, b) __builtin_mul_overflow(a, b, r)
 456 # endif
 457 #elif 7 <= __GNUC__
 458 # define ckd_add(r, a, b) __builtin_add_overflow(a, b, r)
 459 # define ckd_sub(r, a, b) __builtin_sub_overflow(a, b, r)
 460 # define ckd_mul(r, a, b) __builtin_mul_overflow(a, b, r)
 461 #endif
 462
 463 #if 3 <= __GNUC__
 464 # define ATTRIBUTE_MALLOC __attribute__((malloc))
 465 # define ATTRIBUTE_FORMAT(spec) __attribute__((format spec))
 466 #else
 467 # define ATTRIBUTE_MALLOC /* empty */
 468 # define ATTRIBUTE_FORMAT(spec) /* empty */
 469 #endif
 470
 471 #if (defined __has_c_attribute \
 472      && (202311 <= __STDC_VERSION__ || !defined __STRICT_ANSI__))
 473 # define HAVE___HAS_C_ATTRIBUTE true
 474 #else
 475 # define HAVE___HAS_C_ATTRIBUTE false
 476 #endif
 477
 478 #if HAVE___HAS_C_ATTRIBUTE
 479 # if __has_c_attribute(deprecated)
 480 #  define ATTRIBUTE_DEPRECATED [[deprecated]]
 481 # endif
 482 #endif
 483 #ifndef ATTRIBUTE_DEPRECATED
 484 # if 3 < __GNUC__ + (2 <= __GNUC_MINOR__)
 485 #  define ATTRIBUTE_DEPRECATED __attribute__((deprecated))
 486 # else
 487 #  define ATTRIBUTE_DEPRECATED /* empty */
 488 # endif
 489 #endif
 490
 491 #if HAVE___HAS_C_ATTRIBUTE
 492 # if __has_c_attribute(fallthrough)
 493 #  define ATTRIBUTE_FALLTHROUGH [[fallthrough]]
 494 # endif
 495 #endif
 496 #ifndef ATTRIBUTE_FALLTHROUGH
 497 # if 7 <= __GNUC__
 498 #  define ATTRIBUTE_FALLTHROUGH __attribute__((fallthrough))
 499 # else
 500 #  define ATTRIBUTE_FALLTHROUGH ((void) 0)
 501 # endif
 502 #endif
 503
 504 #if HAVE___HAS_C_ATTRIBUTE
 505 # if __has_c_attribute(maybe_unused)
 506 #  define ATTRIBUTE_MAYBE_UNUSED [[maybe_unused]]
 507 # endif
 508 #endif
 509 #ifndef ATTRIBUTE_MAYBE_UNUSED
 510 # if 2 < __GNUC__ + (7 <= __GNUC_MINOR__)
 511 #  define ATTRIBUTE_MAYBE_UNUSED __attribute__((unused))
 512 # else
 513 #  define ATTRIBUTE_MAYBE_UNUSED /* empty */
 514 # endif
 515 #endif
 516
 517 #if HAVE___HAS_C_ATTRIBUTE
 518 # if __has_c_attribute(noreturn)
 519 #  define ATTRIBUTE_NORETURN [[noreturn]]
 520 # endif
 521 #endif
 522 #ifndef ATTRIBUTE_NORETURN
 523 # if 201112 <= __STDC_VERSION__
 524 #  define ATTRIBUTE_NORETURN _Noreturn
 525 # elif 2 < __GNUC__ + (8 <= __GNUC_MINOR__)
 526 #  define ATTRIBUTE_NORETURN __attribute__((noreturn))
 527 # else
 528 #  define ATTRIBUTE_NORETURN /* empty */
 529 # endif
 530 #endif
 531
 532 #if HAVE___HAS_C_ATTRIBUTE
 533 # if __has_c_attribute(reproducible)
 534 #  define ATTRIBUTE_REPRODUCIBLE [[reproducible]]
 535 # endif
 536 #endif
 537 #ifndef ATTRIBUTE_REPRODUCIBLE
 538 # if 3 <= __GNUC__
 539 #  define ATTRIBUTE_REPRODUCIBLE __attribute__((pure))
 540 # else
 541 #  define ATTRIBUTE_REPRODUCIBLE /* empty */
 542 # endif
 543 #endif
 544
 545 #if HAVE___HAS_C_ATTRIBUTE
 546 # if __has_c_attribute(unsequenced)
 547 #  define ATTRIBUTE_UNSEQUENCED [[unsequenced]]
 548 # endif
 549 #endif
 550 #ifndef ATTRIBUTE_UNSEQUENCED
 551 # if 3 <= __GNUC__
 552 #  define ATTRIBUTE_UNSEQUENCED __attribute__((const))
 553 # else
 554 #  define ATTRIBUTE_UNSEQUENCED /* empty */
 555 # endif
 556 #endif
 557
 558 #if (__STDC_VERSION__ < 199901 && !defined restrict \
 559      && (PORT_TO_C89 || defined _MSC_VER))
 560 # define restrict /* empty */
 561 #endif
 562
 563 /*
 564 ** Workarounds for compilers/systems.
 565 */
 566
 567 #ifndef EPOCH_LOCAL
 568 # define EPOCH_LOCAL 0
 569 #endif
 570 #ifndef EPOCH_OFFSET
 571 # define EPOCH_OFFSET 0
 572 #endif
 573 #ifndef RESERVE_STD_EXT_IDS
 574 # define RESERVE_STD_EXT_IDS 0
 575 #endif
 576
 577 /* If standard C identifiers with external linkage (e.g., localtime)
 578    are reserved and are not already being renamed anyway, rename them
 579    as if compiling with '-Dtime_tz=time_t'.  */
 580 #if !defined time_tz && RESERVE_STD_EXT_IDS && USE_LTZ
 581 # define time_tz time_t
 582 #endif
 583
 584 /*
 585 ** Compile with -Dtime_tz=T to build the tz package with a private
 586 ** time_t type equivalent to T rather than the system-supplied time_t.
 587 ** This debugging feature can test unusual design decisions
 588 ** (e.g., time_t wider than 'long', or unsigned time_t) even on
 589 ** typical platforms.
 590 */
 591 #if defined time_tz || EPOCH_LOCAL || EPOCH_OFFSET != 0
 592 # define TZ_TIME_T 1
 593 #else
 594 # define TZ_TIME_T 0
 595 #endif
 596
 597 #if defined LOCALTIME_IMPLEMENTATION && TZ_TIME_T
 598 static time_t sys_time(time_t *x) { return time(x); }
 599 #endif
 600
 601 #if TZ_TIME_T
 602
 603 typedef time_tz tz_time_t;
 604
 605 # undef  asctime
 606 # define asctime tz_asctime
 607 # undef  asctime_r
 608 # define asctime_r tz_asctime_r
 609 # undef  ctime
 610 # define ctime tz_ctime
 611 # undef  ctime_r
 612 # define ctime_r tz_ctime_r
 613 # undef  difftime
 614 # define difftime tz_difftime
 615 # undef  gmtime
 616 # define gmtime tz_gmtime
 617 # undef  gmtime_r
 618 # define gmtime_r tz_gmtime_r
 619 # undef  localtime
 620 # define localtime tz_localtime
 621 # undef  localtime_r
 622 # define localtime_r tz_localtime_r
 623 # undef  localtime_rz
 624 # define localtime_rz tz_localtime_rz
 625 # undef  mktime
 626 # define mktime tz_mktime
 627 # undef  mktime_z
 628 # define mktime_z tz_mktime_z
 629 # undef  offtime
 630 # define offtime tz_offtime
 631 # undef  posix2time
 632 # define posix2time tz_posix2time
 633 # undef  posix2time_z
 634 # define posix2time_z tz_posix2time_z
 635 # undef  strftime
 636 # define strftime tz_strftime
 637 # undef  time
 638 # define time tz_time
 639 # undef  time2posix
 640 # define time2posix tz_time2posix
 641 # undef  time2posix_z
 642 # define time2posix_z tz_time2posix_z
 643 # undef  time_t
 644 # define time_t tz_time_t
 645 # undef  timegm
 646 # define timegm tz_timegm
 647 # undef  timelocal
 648 # define timelocal tz_timelocal
 649 # undef  timeoff
 650 # define timeoff tz_timeoff
 651 # undef  tzalloc
 652 # define tzalloc tz_tzalloc
 653 # undef  tzfree
 654 # define tzfree tz_tzfree
 655 # undef  tzset
 656 # define tzset tz_tzset
 657 # if HAVE_STRFTIME_L
 658 #  undef  strftime_l
 659 #  define strftime_l tz_strftime_l
 660 # endif
 661 # if HAVE_TZNAME
 662 #  undef  tzname
 663 #  define tzname tz_tzname
 664 # endif
 665 # if USG_COMPAT
 666 #  undef  daylight
 667 #  define daylight tz_daylight
 668 #  undef  timezone
 669 #  define timezone tz_timezone
 670 # endif
 671 # if ALTZONE
 672 #  undef  altzone
 673 #  define altzone tz_altzone
 674 # endif
 675
 676 # if __STDC_VERSION__ < 202311
 677 #  define DEPRECATED_IN_C23 /* empty */
 678 # else
 679 #  define DEPRECATED_IN_C23 ATTRIBUTE_DEPRECATED
 680 # endif
 681 DEPRECATED_IN_C23 char *asctime(struct tm const *);
 682 char *asctime_r(struct tm const *restrict, char *restrict);
 683 DEPRECATED_IN_C23 char *ctime(time_t const *);
 684 char *ctime_r(time_t const *, char *);
 685 ATTRIBUTE_UNSEQUENCED double difftime(time_t, time_t);
 686 size_t strftime(char *restrict, size_t, char const *restrict,
 687                 struct tm const *restrict);
 688 # if HAVE_STRFTIME_L
 689 size_t strftime_l(char *restrict, size_t, char const *restrict,
 690                   struct tm const *restrict, locale_t);
 691 # endif
 692 struct tm *gmtime(time_t const *);
 693 struct tm *gmtime_r(time_t const *restrict, struct tm *restrict);
 694 struct tm *localtime(time_t const *);
 695 struct tm *localtime_r(time_t const *restrict, struct tm *restrict);
 696 time_t mktime(struct tm *);
 697 time_t time(time_t *);
 698 time_t timegm(struct tm *);
 699 void tzset(void);
 700 #endif
 701
 702 #ifndef HAVE_DECL_TIMEGM
 703 # if (202311 <= __STDC_VERSION__ \
 704       || defined __GLIBC__ || defined __tm_zone /* musl */ \
 705       || defined __FreeBSD__ || defined __NetBSD__ || defined __OpenBSD__ \
 706       || (defined __APPLE__ && defined __MACH__))
 707 #  define HAVE_DECL_TIMEGM true
 708 # else
 709 #  define HAVE_DECL_TIMEGM false
 710 # endif
 711 #endif
 712 #if !HAVE_DECL_TIMEGM && !defined timegm
 713 time_t timegm(struct tm *);
 714 #endif
 715
 716 #if !HAVE_DECL_ASCTIME_R && !defined asctime_r
 717 extern char *asctime_r(struct tm const *restrict, char *restrict);
 718 #endif
 719
 720 #ifndef HAVE_DECL_ENVIRON
 721 # if defined environ || defined __USE_GNU
 722 #  define HAVE_DECL_ENVIRON 1
 723 # else
 724 #  define HAVE_DECL_ENVIRON 0
 725 # endif
 726 #endif
 727
 728 #if !HAVE_DECL_ENVIRON
 729 extern char **environ;
 730 #endif
 731
 732 #if 2 <= HAVE_TZNAME + (TZ_TIME_T || !HAVE_POSIX_DECLS)
 733 extern char *tzname[];
 734 #endif
 735 #if 2 <= USG_COMPAT + (TZ_TIME_T || !HAVE_POSIX_DECLS)
 736 extern long timezone;
 737 extern int daylight;
 738 #endif
 739 #if 2 <= ALTZONE + (TZ_TIME_T || !HAVE_POSIX_DECLS)
 740 extern long altzone;
 741 #endif
 742
 743 /*
 744 ** The STD_INSPIRED functions are similar, but most also need
 745 ** declarations if time_tz is defined.
 746 */
 747
 748 #ifndef STD_INSPIRED
 749 # define STD_INSPIRED 0
 750 #endif
 751 #if STD_INSPIRED
 752 # if TZ_TIME_T || !defined offtime
 753 struct tm *offtime(time_t const *, long);
 754 # endif
 755 # if TZ_TIME_T || !defined timelocal
 756 time_t timelocal(struct tm *);
 757 # endif
 758 # if TZ_TIME_T || !defined timeoff
 759 #  define EXTERN_TIMEOFF
 760 # endif
 761 # if TZ_TIME_T || !defined time2posix
 762 time_t time2posix(time_t);
 763 # endif
 764 # if TZ_TIME_T || !defined posix2time
 765 time_t posix2time(time_t);
 766 # endif
 767 #endif
 768
 769 /* Infer TM_ZONE on systems where this information is known, but suppress
 770    guessing if NO_TM_ZONE is defined.  Similarly for TM_GMTOFF.  */
 771 #if (200809 < _POSIX_VERSION \
 772      || defined __GLIBC__ \
 773      || defined __tm_zone /* musl */ \
 774      || defined __FreeBSD__ || defined __NetBSD__ || defined __OpenBSD__ \
 775      || (defined __APPLE__ && defined __MACH__))
 776 # if !defined TM_GMTOFF && !defined NO_TM_GMTOFF
 777 #  define TM_GMTOFF tm_gmtoff
 778 # endif
 779 # if !defined TM_ZONE && !defined NO_TM_ZONE
 780 #  define TM_ZONE tm_zone
 781 # endif
 782 #endif
 783
 784 /*
 785 ** Define functions that are ABI compatible with NetBSD but have
 786 ** better prototypes.  NetBSD 6.1.4 defines a pointer type timezone_t
 787 ** and labors under the misconception that 'const timezone_t' is a
 788 ** pointer to a constant.  This use of 'const' is ineffective, so it
 789 ** is not done here.  What we call 'struct state' NetBSD calls
 790 ** 'struct __state', but this is a private name so it doesn't matter.
 791 */
 792 #if NETBSD_INSPIRED
 793 typedef struct state *timezone_t;
 794 struct tm *localtime_rz(timezone_t restrict, time_t const *restrict,
 795                         struct tm *restrict);
 796 time_t mktime_z(timezone_t restrict, struct tm *restrict);
 797 timezone_t tzalloc(char const *);
 798 void tzfree(timezone_t);
 799 # if STD_INSPIRED
 800 #  if TZ_TIME_T || !defined posix2time_z
 801 ATTRIBUTE_REPRODUCIBLE time_t posix2time_z(timezone_t, time_t);
 802 #  endif
 803 #  if TZ_TIME_T || !defined time2posix_z
 804 ATTRIBUTE_REPRODUCIBLE time_t time2posix_z(timezone_t, time_t);
 805 #  endif
 806 # endif
 807 #endif
 808
 809 /*
 810 ** Finally, some convenience items.
 811 */
 812
 813 #define TYPE_BIT(type) (CHAR_BIT * (ptrdiff_t) sizeof(type))
 814 #define TYPE_SIGNED(type) (((type) -1) < 0)
 815 #define TWOS_COMPLEMENT(t) ((t) ~ (t) 0 < 0)
 816
 817 /* Minimum and maximum of two values.  Use lower case to avoid
 818    naming clashes with standard include files.  */
 819 #define max(a, b) ((a) > (b) ? (a) : (b))
 820 #define min(a, b) ((a) < (b) ? (a) : (b))
 821
 822 /* Max and min values of the integer type T, of which only the bottom
 823    B bits are used, and where the highest-order used bit is considered
 824    to be a sign bit if T is signed.  */
 825 #define MAXVAL(t, b)                                            \
 826   ((t) (((t) 1 << ((b) - 1 - TYPE_SIGNED(t)))                   \
 827         - 1 + ((t) 1 << ((b) - 1 - TYPE_SIGNED(t)))))
 828 #define MINVAL(t, b)                                            \
 829   ((t) (TYPE_SIGNED(t) ? - TWOS_COMPLEMENT(t) - MAXVAL(t, b) : 0))
 830
 831 /* The extreme time values, assuming no padding.  */
 832 #define TIME_T_MIN_NO_PADDING MINVAL(time_t, TYPE_BIT(time_t))
 833 #define TIME_T_MAX_NO_PADDING MAXVAL(time_t, TYPE_BIT(time_t))
 834
 835 /* The extreme time values.  These are macros, not constants, so that
 836    any portability problems occur only when compiling .c files that use
 837    the macros, which is safer for applications that need only zdump and zic.
 838    This implementation assumes no padding if time_t is signed and
 839    either the compiler lacks support for _Generic or time_t is not one
 840    of the standard signed integer types.  */
 841 #if HAVE__GENERIC
 842 # define TIME_T_MIN \
 843     _Generic((time_t) 0, \
 844              signed char: SCHAR_MIN, short: SHRT_MIN, \
 845              int: INT_MIN, long: LONG_MIN, long long: LLONG_MIN, \
 846              default: TIME_T_MIN_NO_PADDING)
 847 # define TIME_T_MAX \
 848     (TYPE_SIGNED(time_t) \
 849      ? _Generic((time_t) 0, \
 850                 signed char: SCHAR_MAX, short: SHRT_MAX, \
 851                 int: INT_MAX, long: LONG_MAX, long long: LLONG_MAX, \
 852                 default: TIME_T_MAX_NO_PADDING)                     \
 853      : (time_t) -1)
 854 enum { SIGNED_PADDING_CHECK_NEEDED
 855          = _Generic((time_t) 0,
 856                     signed char: false, short: false,
 857                     int: false, long: false, long long: false,
 858                     default: true) };
 859 #else
 860 # define TIME_T_MIN TIME_T_MIN_NO_PADDING
 861 # define TIME_T_MAX TIME_T_MAX_NO_PADDING
 862 enum { SIGNED_PADDING_CHECK_NEEDED = true };
 863 #endif
 864 /* Try to check the padding assumptions.  Although TIME_T_MAX and the
 865    following check can both have undefined behavior on oddball
 866    platforms due to shifts exceeding widths of signed integers, these
 867    platforms' compilers are likely to diagnose these issues in integer
 868    constant expressions, so it shouldn't hurt to check statically.  */
 869 static_assert(! TYPE_SIGNED(time_t) || ! SIGNED_PADDING_CHECK_NEEDED
 870               || TIME_T_MAX >> (TYPE_BIT(time_t) - 2) == 1);
 871
 872 /*
 873 ** 302 / 1000 is log10(2.0) rounded up.
 874 ** Subtract one for the sign bit if the type is signed;
 875 ** add one for integer division truncation;
 876 ** add one more for a minus sign if the type is signed.
 877 */
 878 #define INT_STRLEN_MAXIMUM(type) \
 879         ((TYPE_BIT(type) - TYPE_SIGNED(type)) * 302 / 1000 + \
 880         1 + TYPE_SIGNED(type))
 881
 882 /*
 883 ** INITIALIZE(x)
 884 */
 885
 886 #ifdef GCC_LINT
 887 # define INITIALIZE(x)  ((x) = 0)
 888 #else
 889 # define INITIALIZE(x)
 890 #endif
 891
 892 /* Whether memory access must strictly follow the C standard.
 893    If 0, it's OK to read uninitialized storage so long as the value is
 894    not relied upon.  Defining it to 0 lets mktime access parts of
 895    struct tm that might be uninitialized, as a heuristic when the
 896    standard doesn't say what to return and when tm_gmtoff can help
 897    mktime likely infer a better value.  */
 898 #ifndef UNINIT_TRAP
 899 # define UNINIT_TRAP 0
 900 #endif
 901
 902 /* localtime.c sometimes needs access to timeoff if it is not already public.
 903    tz_private_timeoff should be used only by localtime.c.  */
 904 #if (!defined EXTERN_TIMEOFF \
 905      && defined TM_GMTOFF && (200809 < _POSIX_VERSION || ! UNINIT_TRAP))
 906 # ifndef timeoff
 907 #  define timeoff tz_private_timeoff
 908 # endif
 909 # define EXTERN_TIMEOFF
 910 #endif
 911 #ifdef EXTERN_TIMEOFF
 912 time_t timeoff(struct tm *, long);
 913 #endif
 914
 915 #ifdef DEBUG
 916 # undef unreachable
 917 # define unreachable() abort()
 918 #elif !defined unreachable
 919 # ifdef __has_builtin
 920 #  if __has_builtin(__builtin_unreachable)
 921 #   define unreachable() __builtin_unreachable()
 922 #  endif
 923 # elif 4 < __GNUC__ + (5 <= __GNUC_MINOR__)
 924 #  define unreachable() __builtin_unreachable()
 925 # endif
 926 # ifndef unreachable
 927 #  define unreachable() ((void) 0)
 928 # endif
 929 #endif
 930
 931 /*
 932 ** For the benefit of GNU folk...
 933 ** '_(MSGID)' uses the current locale's message library string for MSGID.
 934 ** The default is to use gettext if available, and use MSGID otherwise.
 935 */
 936
 937 #if HAVE_GETTEXT
 938 #define _(msgid) gettext(msgid)
 939 #else /* !HAVE_GETTEXT */
 940 #define _(msgid) msgid
 941 #endif /* !HAVE_GETTEXT */
 942
 943 #if !defined TZ_DOMAIN && defined HAVE_GETTEXT
 944 # define TZ_DOMAIN "tz"
 945 #endif
 946
 947 #if HAVE_INCOMPATIBLE_CTIME_R
 948 #undef asctime_r
 949 #undef ctime_r
 950 char *asctime_r(struct tm const *restrict, char *restrict);
 951 char *ctime_r(time_t const *, char *);
 952 #endif /* HAVE_INCOMPATIBLE_CTIME_R */
 953
 954 /* Handy macros that are independent of tzfile implementation.  */
 955
 956 enum {
 957   SECSPERMIN = 60,
 958   MINSPERHOUR = 60,
 959   SECSPERHOUR = SECSPERMIN * MINSPERHOUR,
 960   HOURSPERDAY = 24,
 961   DAYSPERWEEK = 7,
 962   DAYSPERNYEAR = 365,
 963   DAYSPERLYEAR = DAYSPERNYEAR + 1,
 964   MONSPERYEAR = 12,
 965   YEARSPERREPEAT = 400  /* years before a Gregorian repeat */
 966 };
 967
 968 #define SECSPERDAY      ((int_fast32_t) SECSPERHOUR * HOURSPERDAY)
 969
 970 #define DAYSPERREPEAT           ((int_fast32_t) 400 * 365 + 100 - 4 + 1)
 971 #define SECSPERREPEAT           ((int_fast64_t) DAYSPERREPEAT * SECSPERDAY)
 972 #define AVGSECSPERYEAR          (SECSPERREPEAT / YEARSPERREPEAT)
 973
 974 /* How many years to generate (in zic.c) or search through (in localtime.c).
 975    This is two years larger than the obvious 400, to avoid edge cases.
 976    E.g., suppose a non-POSIX.1-2017 rule applies from 2012 on with transitions
 977    in March and September, plus one-off transitions in November 2013.
 978    If zic looked only at the last 400 years, it would set max_year=2413,
 979    with the intent that the 400 years 2014 through 2413 will be repeated.
 980    The last transition listed in the tzfile would be in 2413-09,
 981    less than 400 years after the last one-off transition in 2013-11.
 982    Two years is not overkill for localtime.c, as a one-year bump
 983    would mishandle 2023d's America/Ciudad_Juarez for November 2422.  */
 984 enum { years_of_observations = YEARSPERREPEAT + 2 };
 985
 986 enum {
 987   TM_SUNDAY,
 988   TM_MONDAY,
 989   TM_TUESDAY,
 990   TM_WEDNESDAY,
 991   TM_THURSDAY,
 992   TM_FRIDAY,
 993   TM_SATURDAY
 994 };
 995
 996 enum {
 997   TM_JANUARY,
 998   TM_FEBRUARY,
 999   TM_MARCH,
1000   TM_APRIL,
1001   TM_MAY,
1002   TM_JUNE,
1003   TM_JULY,
1004   TM_AUGUST,
1005   TM_SEPTEMBER,
1006   TM_OCTOBER,
1007   TM_NOVEMBER,
1008   TM_DECEMBER
1009 };
1010
1011 enum {
1012   TM_YEAR_BASE = 1900,
1013   TM_WDAY_BASE = TM_MONDAY,
1014   EPOCH_YEAR = 1970,
1015   EPOCH_WDAY = TM_THURSDAY
1016 };
1017
1018 #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
1019
1020 /*
1021 ** Since everything in isleap is modulo 400 (or a factor of 400), we know that
1022 **      isleap(y) == isleap(y % 400)
1023 ** and so
1024 **      isleap(a + b) == isleap((a + b) % 400)
1025 ** or
1026 **      isleap(a + b) == isleap(a % 400 + b % 400)
1027 ** This is true even if % means modulo rather than Fortran remainder
1028 ** (which is allowed by C89 but not by C99 or later).
1029 ** We use this to avoid addition overflow problems.
1030 */
1031
1032 #define isleap_sum(a, b)        isleap((a) % 400 + (b) % 400)
1033
1034 #endif /* !defined PRIVATE_H */