xref: /src/contrib/tzcode/private.h (revision ff2c98b30b57b9763e2a6575f729bab676e6c025)
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.
23 
24    This macro is obsolescent, and the plan is to remove it along with
25    associated code.  A good time to do that might be in the year 2029
26    because RHEL 7 (whose GCC defaults to C89) extended life cycle
27    support (ELS) is scheduled to end on 2028-06-30.  */
28 #ifndef PORT_TO_C89
29 # define PORT_TO_C89 0
30 #endif
31 
32 /* SUPPORT_C89 means the tzcode library should support C89 callers
33    in addition to the usual support for C99-and-later callers.
34    This defaults to 1 as POSIX requires, even though that can trigger
35    latent bugs in callers.  */
36 #ifndef SUPPORT_C89
37 # define SUPPORT_C89 1
38 #endif
39 
40 
41 /* The following feature-test macros should be defined before
42    any #include of a system header.  */
43 
44 /* Enable tm_gmtoff, tm_zone, and environ on GNUish systems.  */
45 #define _GNU_SOURCE 1
46 /* Fix asctime_r on Solaris 11.  */
47 #define _POSIX_PTHREAD_SEMANTICS 1
48 /* Enable strtoimax on pre-C99 Solaris 11.  */
49 #define __EXTENSIONS__ 1
50 /* Cause MS-Windows headers to define POSIX names.  */
51 #define _CRT_DECLARE_NONSTDC_NAMES 1
52 /* Prevent MS-Windows headers from defining min and max.  */
53 #define NOMINMAX 1
54 
55 /* On GNUish systems where time_t might be 32 or 64 bits, use 64.
56    On these platforms _FILE_OFFSET_BITS must also be 64; otherwise
57    setting _TIME_BITS to 64 does not work.  The code does not
58    otherwise rely on _FILE_OFFSET_BITS being 64, since it does not
59    use off_t or functions like 'stat' that depend on off_t.  */
60 #ifndef _TIME_BITS
61 # ifndef _FILE_OFFSET_BITS
62 #  define _FILE_OFFSET_BITS 64
63 # endif
64 # if _FILE_OFFSET_BITS == 64
65 #  define _TIME_BITS 64
66 # endif
67 #endif
68 
69 /* End of feature-test macro definitions.  */
70 
71 
72 #ifndef __STDC_VERSION__
73 # define __STDC_VERSION__ 0
74 #endif
75 
76 /* Define true, false and bool if they don't work out of the box.  */
77 #if PORT_TO_C89 && __STDC_VERSION__ < 199901
78 # define true 1
79 # define false 0
80 # define bool int
81 #elif __STDC_VERSION__ < 202311
82 # include <stdbool.h>
83 #endif
84 
85 /* For pre-C23 compilers, a substitute for static_assert.
86    Some of these compilers may warn if it is used outside the top level.  */
87 #if __STDC_VERSION__ < 202311 && !defined static_assert
88 # define static_assert(cond) extern int static_assert_check[(cond) ? 1 : -1]
89 #endif
90 
91 /*
92 ** zdump has been made independent of the rest of the time
93 ** conversion package to increase confidence in the verification it provides.
94 ** You can use zdump to help in verifying other implementations.
95 ** To do this, compile with -DUSE_LTZ=0 and link without the tz library.
96 */
97 #ifndef USE_LTZ
98 # define USE_LTZ 1
99 #endif
100 
101 /* This string was in the Factory zone through version 2016f.  */
102 #ifndef GRANDPARENTED
103 # define GRANDPARENTED	"Local time zone must be set--see zic manual page"
104 #endif
105 
106 /*
107 ** Defaults for preprocessor symbols.
108 ** You can override these in your C compiler options, e.g. '-DHAVE_GETTEXT=1'.
109 */
110 
111 #if !defined HAVE__GENERIC && defined __has_extension
112 # if !__has_extension(c_generic_selections)
113 #  define HAVE__GENERIC 0
114 # endif
115 #endif
116 /* _Generic is buggy in pre-4.9 GCC.  */
117 #if !defined HAVE__GENERIC && defined __GNUC__ && !defined __STRICT_ANSI__
118 # define HAVE__GENERIC (4 < __GNUC__ + (9 <= __GNUC_MINOR__))
119 #endif
120 #ifndef HAVE__GENERIC
121 # define HAVE__GENERIC (201112 <= __STDC_VERSION__)
122 #endif
123 
124 #ifndef HAVE_GETEUID
125 # define HAVE_GETEUID 1
126 #endif
127 
128 #ifndef HAVE_GETRESUID
129 # define HAVE_GETRESUID 1
130 #endif
131 
132 #if !defined HAVE_GETTEXT && defined __has_include
133 # if __has_include(<libintl.h>)
134 #  define HAVE_GETTEXT 1
135 # endif
136 #endif
137 #ifndef HAVE_GETTEXT
138 # define HAVE_GETTEXT 0
139 #endif
140 
141 #ifndef HAVE_INCOMPATIBLE_CTIME_R
142 # define HAVE_INCOMPATIBLE_CTIME_R 0
143 #endif
144 
145 #ifndef HAVE_LINK
146 # define HAVE_LINK 1
147 #endif /* !defined HAVE_LINK */
148 
149 #ifndef HAVE_MALLOC_ERRNO
150 # define HAVE_MALLOC_ERRNO 1
151 #endif
152 
153 #ifndef HAVE_POSIX_DECLS
154 # define HAVE_POSIX_DECLS 1
155 #endif
156 
157 #ifndef HAVE_SETENV
158 # define HAVE_SETENV 1
159 #endif
160 
161 #ifndef HAVE_STRDUP
162 # define HAVE_STRDUP 1
163 #endif
164 
165 #ifndef HAVE_SYMLINK
166 # define HAVE_SYMLINK 1
167 #endif /* !defined HAVE_SYMLINK */
168 
169 #if !defined HAVE_SYS_STAT_H && defined __has_include
170 # if !__has_include(<sys/stat.h>)
171 #  define HAVE_SYS_STAT_H 0
172 # endif
173 #endif
174 #ifndef HAVE_SYS_STAT_H
175 # define HAVE_SYS_STAT_H 1
176 #endif
177 
178 #if !defined HAVE_UNISTD_H && defined __has_include
179 # if !__has_include(<unistd.h>)
180 #  define HAVE_UNISTD_H 0
181 # endif
182 #endif
183 #ifndef HAVE_UNISTD_H
184 # define HAVE_UNISTD_H 1
185 #endif
186 
187 #ifndef NETBSD_INSPIRED
188 # define NETBSD_INSPIRED 1
189 #endif
190 
191 #if HAVE_INCOMPATIBLE_CTIME_R
192 # define asctime_r _incompatible_asctime_r
193 # define ctime_r _incompatible_ctime_r
194 #endif /* HAVE_INCOMPATIBLE_CTIME_R */
195 
196 #ifndef TZ_RUNTIME_LEAPS
197 # define TZ_RUNTIME_LEAPS 1
198 #endif
199 
200 /*
201 ** Nested includes
202 */
203 
204 #include <stddef.h>
205 
206 /* If defining the 'timezone' variable a la POSIX, avoid clashing with the old
207    'timezone' function of FreeBSD <= 14, by renaming the latter's declaration.
208    This hack can be removed after 2028-11-30, FreeBSD 14's expected EOL.  */
209 #if (defined __FreeBSD__  && __FreeBSD__ < 15 && defined __BSD_VISIBLE \
210      && defined USG_COMPAT  && USG_COMPAT == 2)
211 # define timezone sys_timezone
212 # define timezone_defined
213 #endif
214 
215 #include <time.h>
216 
217 #ifdef timezone_defined
218 # undef timezone
219 # undef timezone_defined
220 #endif
221 
222 #include <string.h>
223 #if defined HAVE_STRNLEN && !HAVE_STRNLEN
224 static size_t
strnlen(char const * s,size_t maxlen)225 strnlen (char const *s, size_t maxlen)
226 {
227   size_t i;
228   for (i = 0; i < maxlen && s[i]; i++)
229     continue;
230   return i;
231 }
232 #endif
233 
234 #if !PORT_TO_C89
235 # include <inttypes.h>
236 #endif
237 #include <limits.h>	/* for CHAR_BIT et al. */
238 #include <stdlib.h>
239 
240 #include <errno.h>
241 
242 #ifndef EINVAL
243 # define EINVAL ERANGE
244 #endif
245 
246 #ifndef ELOOP
247 # define ELOOP EINVAL
248 #endif
249 #ifndef ENAMETOOLONG
250 # define ENAMETOOLONG EINVAL
251 #endif
252 #ifndef ENOMEM
253 # define ENOMEM EINVAL
254 #endif
255 #ifndef ENOTCAPABLE
256 # define ENOTCAPABLE EINVAL
257 #endif
258 #ifndef ENOTSUP
259 # define ENOTSUP EINVAL
260 #endif
261 #ifndef EOVERFLOW
262 # define EOVERFLOW EINVAL
263 #endif
264 
265 #if HAVE_GETTEXT
266 # include <libintl.h>
267 #endif /* HAVE_GETTEXT */
268 
269 #if HAVE_UNISTD_H
270 # include <unistd.h>
271 #else
272 /* Assume getopt.o or equivalent is linked via Makefile configuration.  */
273 int getopt(int, char *const[], char const *);
274 extern char *optarg;
275 extern int optind;
276 #endif /* HAVE_UNISTD_H */
277 
278 /* SUPPORT_POSIX2008 means the tzcode library should support
279    POSIX.1-2017-and-earlier callers in addition to the usual support for
280    POSIX.1-2024-and-later callers; however, this can be
281    incompatible with POSIX.1-2024-and-later callers.
282    This macro is obsolescent, and the plan is to remove it
283    along with any code needed only when it is nonzero.
284    A good time to do that might be in the year 2034.
285    This macro's name is SUPPORT_POSIX2008 because _POSIX_VERSION == 200809
286    in POSIX.1-2017, a minor revision of POSIX.1-2008.  */
287 #ifndef SUPPORT_POSIX2008
288 # if defined _POSIX_VERSION && _POSIX_VERSION <= 200809
289 #  define SUPPORT_POSIX2008 1
290 # else
291 #  define SUPPORT_POSIX2008 0
292 # endif
293 #endif
294 
295 #ifndef HAVE_DECL_ASCTIME_R
296 # if SUPPORT_POSIX2008
297 #  define HAVE_DECL_ASCTIME_R 1
298 # else
299 #  define HAVE_DECL_ASCTIME_R 0
300 # endif
301 #endif
302 
303 #ifndef HAVE_ISSETUGID
304 # if (defined __FreeBSD__ || defined __NetBSD__ || defined __OpenBSD__ \
305       || (defined __linux__ && !defined __GLIBC__) /* Android, musl, etc. */ \
306       || (defined __APPLE__ && defined __MACH__) || defined __sun)
307 #  define HAVE_ISSETUGID 1
308 # else
309 #  define HAVE_ISSETUGID 0
310 # endif
311 #endif
312 
313 #ifndef HAVE_SNPRINTF
314 # define HAVE_SNPRINTF (!PORT_TO_C89 || 199901 <= __STDC_VERSION__)
315 #endif
316 
317 #ifndef HAVE_STRFTIME_L
318 # if _POSIX_VERSION < 200809
319 #  define HAVE_STRFTIME_L 0
320 # else
321 #  define HAVE_STRFTIME_L 1
322 # endif
323 #endif
324 
325 #ifndef USG_COMPAT
326 # ifndef _XOPEN_VERSION
327 #  define USG_COMPAT 0
328 # else
329 #  define USG_COMPAT 1
330 # endif
331 #endif
332 
333 #ifndef HAVE_TZNAME
334 # if _POSIX_VERSION < 198808 && !USG_COMPAT
335 #  define HAVE_TZNAME 0
336 # else
337 #  define HAVE_TZNAME 1
338 # endif
339 #endif
340 
341 #ifndef ALTZONE
342 # if defined __sun || defined _M_XENIX
343 #  define ALTZONE 1
344 # else
345 #  define ALTZONE 0
346 # endif
347 #endif
348 
349 #if PORT_TO_C89
350 
351 /*
352 ** Define HAVE_STDINT_H's default value here, rather than at the
353 ** start, since __GLIBC__ and INTMAX_MAX's values depend on
354 ** previously included files.  glibc 2.1 and Solaris 10 and later have
355 ** stdint.h, even with pre-C99 compilers.
356 */
357 # if !defined HAVE_STDINT_H && defined __has_include
358 #  define HAVE_STDINT_H 1 /* C23 __has_include implies C99 stdint.h.  */
359 # endif
360 # ifndef HAVE_STDINT_H
361 #  define HAVE_STDINT_H \
362     (199901 <= __STDC_VERSION__ \
363      || 2 < __GLIBC__ + (1 <= __GLIBC_MINOR__) \
364      || __CYGWIN__ || INTMAX_MAX)
365 # endif /* !defined HAVE_STDINT_H */
366 
367 # if HAVE_STDINT_H
368 #  include <stdint.h>
369 # endif /* !HAVE_STDINT_H */
370 
371 # ifndef HAVE_INTTYPES_H
372 #  define HAVE_INTTYPES_H HAVE_STDINT_H
373 # endif
374 # if HAVE_INTTYPES_H
375 #  include <inttypes.h>
376 # endif
377 
378 /* Pre-C99 GCC compilers define __LONG_LONG_MAX__ instead of LLONG_MAX.  */
379 # if defined __LONG_LONG_MAX__ && !defined __STRICT_ANSI__
380 #  ifndef LLONG_MAX
381 #   define LLONG_MAX __LONG_LONG_MAX__
382 #  endif
383 #  ifndef LLONG_MIN
384 #   define LLONG_MIN (-1 - LLONG_MAX)
385 #  endif
386 #  ifndef ULLONG_MAX
387 #   define ULLONG_MAX (LLONG_MAX * 2ull + 1)
388 #  endif
389 # endif
390 
391 # ifndef INT_FAST64_MAX
392 #  if 1 <= LONG_MAX >> 31 >> 31
393 typedef long int_fast64_t;
394 #   define INT_FAST64_MIN LONG_MIN
395 #   define INT_FAST64_MAX LONG_MAX
396 #  else
397 /* If this fails, compile with -DHAVE_STDINT_H or with a better compiler.  */
398 typedef long long int_fast64_t;
399 #   define INT_FAST64_MIN LLONG_MIN
400 #   define INT_FAST64_MAX LLONG_MAX
401 #  endif
402 # endif
403 
404 # ifndef PRIdFAST64
405 #  if INT_FAST64_MAX == LONG_MAX
406 #   define PRIdFAST64 "ld"
407 #  else
408 #   define PRIdFAST64 "lld"
409 #  endif
410 # endif
411 
412 # ifndef SCNdFAST64
413 #  define SCNdFAST64 PRIdFAST64
414 # endif
415 
416 # ifndef INT_FAST32_MAX
417 typedef long int_fast32_t;
418 #  define INT_FAST32_MAX LONG_MAX
419 #  define INT_FAST32_MIN LONG_MIN
420 # endif
421 
422 # ifndef INT_LEAST32_MAX
423 typedef int_fast32_t int_least32_t;
424 # endif
425 
426 # ifndef INTMAX_MAX
427 #  ifdef LLONG_MAX
428 typedef long long intmax_t;
429 #   ifndef HAVE_STRTOLL
430 #    define HAVE_STRTOLL 1
431 #   endif
432 #   if HAVE_STRTOLL
433 #    define strtoimax strtoll
434 #   endif
435 #   define INTMAX_MAX LLONG_MAX
436 #   define INTMAX_MIN LLONG_MIN
437 #  else
438 typedef long intmax_t;
439 #   define INTMAX_MAX LONG_MAX
440 #   define INTMAX_MIN LONG_MIN
441 #  endif
442 #  ifndef strtoimax
443 #   define strtoimax strtol
444 #  endif
445 # endif
446 
447 # ifndef PRIdMAX
448 #  if INTMAX_MAX == LLONG_MAX
449 #   define PRIdMAX "lld"
450 #  else
451 #   define PRIdMAX "ld"
452 #  endif
453 # endif
454 
455 # ifndef PTRDIFF_MAX
456 #  define PTRDIFF_MAX MAXVAL(ptrdiff_t, TYPE_BIT(ptrdiff_t))
457 # endif
458 
459 # ifndef UINT_FAST32_MAX
460 typedef unsigned long uint_fast32_t;
461 # endif
462 
463 # ifndef UINT_FAST64_MAX
464 #  if 3 <= ULONG_MAX >> 31 >> 31
465 typedef unsigned long uint_fast64_t;
466 #   define UINT_FAST64_MAX ULONG_MAX
467 #  else
468 /* If this fails, compile with -DHAVE_STDINT_H or with a better compiler.  */
469 typedef unsigned long long uint_fast64_t;
470 #   define UINT_FAST64_MAX ULLONG_MAX
471 #  endif
472 # endif
473 
474 # ifndef UINTMAX_MAX
475 #  ifdef ULLONG_MAX
476 typedef unsigned long long uintmax_t;
477 #   define UINTMAX_MAX ULLONG_MAX
478 #  else
479 typedef unsigned long uintmax_t;
480 #   define UINTMAX_MAX ULONG_MAX
481 #  endif
482 # endif
483 
484 # ifndef PRIuMAX
485 #  ifdef ULLONG_MAX
486 #   define PRIuMAX "llu"
487 #  else
488 #   define PRIuMAX "lu"
489 #  endif
490 # endif
491 
492 # ifndef SIZE_MAX
493 #  define SIZE_MAX ((size_t) -1)
494 # endif
495 
496 #endif /* PORT_TO_C89 */
497 
498 /* The maximum size of any created object, as a signed integer.
499    Although the C standard does not outright prohibit larger objects,
500    behavior is undefined if the result of pointer subtraction does not
501    fit into ptrdiff_t, and the code assumes in several places that
502    pointer subtraction works.  As a practical matter it's OK to not
503    support objects larger than this.  */
504 #define INDEX_MAX ((ptrdiff_t) min(PTRDIFF_MAX, SIZE_MAX))
505 
506 /* Support ckd_add, ckd_sub, ckd_mul on C23 or recent-enough GCC-like
507    hosts, unless compiled with -DHAVE_STDCKDINT_H=0 or with pre-C23 EDG.  */
508 #if !defined HAVE_STDCKDINT_H && defined __has_include
509 # if __has_include(<stdckdint.h>)
510 #  define HAVE_STDCKDINT_H 1
511 # endif
512 #endif
513 #ifdef HAVE_STDCKDINT_H
514 # if HAVE_STDCKDINT_H
515 #  include <stdckdint.h>
516 # endif
517 #elif defined __EDG__
518 /* Do nothing, to work around EDG bug <https://bugs.gnu.org/53256>.  */
519 #elif defined __has_builtin
520 # if __has_builtin(__builtin_add_overflow)
521 #  define ckd_add(r, a, b) __builtin_add_overflow(a, b, r)
522 # endif
523 # if __has_builtin(__builtin_sub_overflow)
524 #  define ckd_sub(r, a, b) __builtin_sub_overflow(a, b, r)
525 # endif
526 # if __has_builtin(__builtin_mul_overflow)
527 #  define ckd_mul(r, a, b) __builtin_mul_overflow(a, b, r)
528 # endif
529 #elif 7 <= __GNUC__
530 # define ckd_add(r, a, b) __builtin_add_overflow(a, b, r)
531 # define ckd_sub(r, a, b) __builtin_sub_overflow(a, b, r)
532 # define ckd_mul(r, a, b) __builtin_mul_overflow(a, b, r)
533 #endif
534 
535 #if (defined __has_c_attribute \
536      && (202311 <= __STDC_VERSION__ || !defined __STRICT_ANSI__))
537 # define HAVE___HAS_C_ATTRIBUTE true
538 #else
539 # define HAVE___HAS_C_ATTRIBUTE false
540 #endif
541 
542 #ifdef __has_attribute
543 # if __has_attribute (nonstring)
544 #  define ATTRIBUTE_NONSTRING __attribute__((__nonstring__))
545 # endif
546 #endif
547 #ifndef ATTRIBUTE_NONSTRING
548 # define ATTRIBUTE_NONSTRING
549 #endif
550 
551 #if HAVE___HAS_C_ATTRIBUTE
552 # if __has_c_attribute(deprecated)
553 #  define ATTRIBUTE_DEPRECATED [[deprecated]]
554 # endif
555 #endif
556 #ifndef ATTRIBUTE_DEPRECATED
557 # if 3 < __GNUC__ + (2 <= __GNUC_MINOR__)
558 #  define ATTRIBUTE_DEPRECATED __attribute__((deprecated))
559 # else
560 #  define ATTRIBUTE_DEPRECATED /* empty */
561 # endif
562 #endif
563 
564 #if HAVE___HAS_C_ATTRIBUTE
565 # if __has_c_attribute(fallthrough)
566 #  define ATTRIBUTE_FALLTHROUGH [[fallthrough]]
567 # endif
568 #endif
569 #ifndef ATTRIBUTE_FALLTHROUGH
570 # if 7 <= __GNUC__
571 #  define ATTRIBUTE_FALLTHROUGH __attribute__((fallthrough))
572 # else
573 #  define ATTRIBUTE_FALLTHROUGH ((void) 0)
574 # endif
575 #endif
576 
577 #if HAVE___HAS_C_ATTRIBUTE
578 # if __has_c_attribute(maybe_unused)
579 #  define ATTRIBUTE_MAYBE_UNUSED [[maybe_unused]]
580 # endif
581 #endif
582 #ifndef ATTRIBUTE_MAYBE_UNUSED
583 # if 2 < __GNUC__ + (7 <= __GNUC_MINOR__)
584 #  define ATTRIBUTE_MAYBE_UNUSED __attribute__((unused))
585 # else
586 #  define ATTRIBUTE_MAYBE_UNUSED /* empty */
587 # endif
588 #endif
589 
590 #if HAVE___HAS_C_ATTRIBUTE
591 # if __has_c_attribute(noreturn)
592 #  define ATTRIBUTE_NORETURN [[noreturn]]
593 # endif
594 #endif
595 #ifndef ATTRIBUTE_NORETURN
596 # if 201112 <= __STDC_VERSION__
597 #  define ATTRIBUTE_NORETURN _Noreturn
598 # elif 2 < __GNUC__ + (8 <= __GNUC_MINOR__)
599 #  define ATTRIBUTE_NORETURN __attribute__((noreturn))
600 # else
601 #  define ATTRIBUTE_NORETURN /* empty */
602 # endif
603 #endif
604 
605 #if HAVE___HAS_C_ATTRIBUTE
606 # if __has_c_attribute(reproducible)
607 #  define ATTRIBUTE_REPRODUCIBLE [[reproducible]]
608 # endif
609 #endif
610 #ifndef ATTRIBUTE_REPRODUCIBLE
611 # define ATTRIBUTE_REPRODUCIBLE /* empty */
612 #endif
613 
614 #if HAVE___HAS_C_ATTRIBUTE
615 # if __has_c_attribute(unsequenced)
616 #  define ATTRIBUTE_UNSEQUENCED [[unsequenced]]
617 # endif
618 #endif
619 #ifndef ATTRIBUTE_UNSEQUENCED
620 # define ATTRIBUTE_UNSEQUENCED /* empty */
621 #endif
622 
623 /* GNU C attributes that are useful in tzcode.
624    Although neither __attribute__((const)) nor __attribute__((pure)) are
625    stricter than their C23 counterparts [[unsequenced]] and [[reproducible]],
626    the C23 attributes happen to work in each tzcode use of ATTRIBUTE_CONST
627    and ATTRIBUTE_PURE.  (This might not work outside of tzcode!)  */
628 #if __GNUC__ < 3
629 # define ATTRIBUTE_CONST ATTRIBUTE_UNSEQUENCED
630 # define ATTRIBUTE_FORMAT(spec) /* empty */
631 # define ATTRIBUTE_PURE ATTRIBUTE_REPRODUCIBLE
632 #else
633 # define ATTRIBUTE_CONST __attribute__((const))
634 # define ATTRIBUTE_FORMAT(spec) __attribute__((format spec))
635 # define ATTRIBUTE_PURE __attribute__((pure))
636 #endif
637 
638 /* Avoid GCC bug 114833 <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114833>.
639    Remove this macro and its uses when the bug is fixed in a GCC release,
640    because only the latest GCC matters for $(GCC_DEBUG_FLAGS).  */
641 #ifdef GCC_LINT
642 # define ATTRIBUTE_PURE_114833 ATTRIBUTE_PURE
643 #else
644 # define ATTRIBUTE_PURE_114833 /* empty */
645 #endif
646 /* GCC_LINT hack to pacify GCC bug 114833 even though the attribute is
647    not strictly correct, as the function might not return whereas pure
648    functions are supposed to return exactly once.  This hack is not
649    known to generate wrong code for tzcode on any platform.
650    Remove this macro and its uses when the bug is fixed in a GCC release.  */
651 #define ATTRIBUTE_PURE_114833_HACK ATTRIBUTE_PURE_114833
652 
653 #if (__STDC_VERSION__ < 199901 && !defined restrict \
654      && (PORT_TO_C89 || defined _MSC_VER))
655 # define restrict /* empty */
656 #endif
657 
658 /*
659 ** Workarounds for compilers/systems.
660 */
661 
662 #ifndef EPOCH_LOCAL
663 # define EPOCH_LOCAL 0
664 #endif
665 #ifndef EPOCH_OFFSET
666 # define EPOCH_OFFSET 0
667 #endif
668 #ifndef RESERVE_STD_EXT_IDS
669 # define RESERVE_STD_EXT_IDS 0
670 #endif
671 
672 #ifdef time_tz
673 # define defined_time_tz true
674 #else
675 # define defined_time_tz false
676 #endif
677 
678 /* If standard C identifiers with external linkage (e.g., localtime)
679    are reserved and are not already being renamed anyway, rename them
680    as if compiling with '-Dtime_tz=time_t'.  */
681 #if !defined time_tz && RESERVE_STD_EXT_IDS && USE_LTZ
682 # define time_tz time_t
683 #endif
684 
685 /*
686 ** Compile with -Dtime_tz=T to build the tz package with a private
687 ** time_t type equivalent to T rather than the system-supplied time_t.
688 ** This debugging feature can test unusual design decisions
689 ** (e.g., time_t wider than 'long', or unsigned time_t) even on
690 ** typical platforms.
691 */
692 #if defined time_tz || EPOCH_LOCAL || EPOCH_OFFSET != 0
693 # define TZ_TIME_T true
694 #else
695 # define TZ_TIME_T false
696 #endif
697 
698 #if defined LOCALTIME_IMPLEMENTATION && TZ_TIME_T
sys_time(time_t * x)699 static time_t sys_time(time_t *x) { return time(x); }
700 #endif
701 
702 #if TZ_TIME_T
703 
704 typedef time_tz tz_time_t;
705 
706 # undef  asctime
707 # define asctime tz_asctime
708 # undef  ctime
709 # define ctime tz_ctime
710 # undef  difftime
711 # define difftime tz_difftime
712 # undef  gmtime
713 # define gmtime tz_gmtime
714 # undef  gmtime_r
715 # define gmtime_r tz_gmtime_r
716 # undef  localtime
717 # define localtime tz_localtime
718 # undef  localtime_r
719 # define localtime_r tz_localtime_r
720 # undef  localtime_rz
721 # define localtime_rz tz_localtime_rz
722 # undef  mktime
723 # define mktime tz_mktime
724 # undef  mktime_z
725 # define mktime_z tz_mktime_z
726 # undef  offtime
727 # define offtime tz_offtime
728 # undef  offtime_r
729 # define offtime_r tz_offtime_r
730 # undef  posix2time
731 # define posix2time tz_posix2time
732 # undef  posix2time_z
733 # define posix2time_z tz_posix2time_z
734 # undef  strftime
735 # define strftime tz_strftime
736 # undef  time
737 # define time tz_time
738 # undef  time2posix
739 # define time2posix tz_time2posix
740 # undef  time2posix_z
741 # define time2posix_z tz_time2posix_z
742 # undef  time_t
743 # define time_t tz_time_t
744 # undef  timegm
745 # define timegm tz_timegm
746 # undef  timelocal
747 # define timelocal tz_timelocal
748 # undef  timeoff
749 # define timeoff tz_timeoff
750 # undef  tzalloc
751 # define tzalloc tz_tzalloc
752 # undef  tzfree
753 # define tzfree tz_tzfree
754 # undef  tzset
755 # define tzset tz_tzset
756 # if SUPPORT_POSIX2008
757 #  undef  asctime_r
758 #  define asctime_r tz_asctime_r
759 #  undef  ctime_r
760 #  define ctime_r tz_ctime_r
761 # endif
762 # if HAVE_STRFTIME_L
763 #  undef  strftime_l
764 #  define strftime_l tz_strftime_l
765 # endif
766 # if HAVE_TZNAME
767 #  undef  tzname
768 #  define tzname tz_tzname
769 # endif
770 # if USG_COMPAT
771 #  undef  daylight
772 #  define daylight tz_daylight
773 #  undef  timezone
774 #  define timezone tz_timezone
775 # endif
776 # if ALTZONE
777 #  undef  altzone
778 #  define altzone tz_altzone
779 # endif
780 
781 # if __STDC_VERSION__ < 202311
782 #  define DEPRECATED_IN_C23 /* empty */
783 # else
784 #  define DEPRECATED_IN_C23 ATTRIBUTE_DEPRECATED
785 # endif
786 DEPRECATED_IN_C23 char *asctime(struct tm const *);
787 DEPRECATED_IN_C23 char *ctime(time_t const *);
788 # if SUPPORT_POSIX2008
789 char *asctime_r(struct tm const *restrict, char *restrict);
790 char *ctime_r(time_t const *, char *);
791 # endif
792 ATTRIBUTE_CONST double difftime(time_t, time_t);
793 size_t strftime(char *restrict, size_t, char const *restrict,
794 		struct tm const *restrict);
795 # if HAVE_STRFTIME_L
796 size_t strftime_l(char *restrict, size_t, char const *restrict,
797 		  struct tm const *restrict, locale_t);
798 # endif
799 struct tm *gmtime(time_t const *);
800 struct tm *gmtime_r(time_t const *restrict, struct tm *restrict);
801 struct tm *localtime(time_t const *);
802 struct tm *localtime_r(time_t const *restrict, struct tm *restrict);
803 time_t mktime(struct tm *);
804 time_t time(time_t *);
805 time_t timegm(struct tm *);
806 void tzset(void);
807 #endif
808 
809 #ifndef HAVE_DECL_TIMEGM
810 # if (202311 <= __STDC_VERSION__ \
811       || defined __GLIBC__ || defined __tm_zone /* musl */ \
812       || defined __FreeBSD__ || defined __NetBSD__ || defined __OpenBSD__ \
813       || (defined __APPLE__ && defined __MACH__))
814 #  define HAVE_DECL_TIMEGM 1
815 # else
816 #  define HAVE_DECL_TIMEGM 0
817 # endif
818 #endif
819 #if !HAVE_DECL_TIMEGM && !defined timegm
820 time_t timegm(struct tm *);
821 #endif
822 
823 #if !HAVE_DECL_ASCTIME_R && !defined asctime_r && SUPPORT_POSIX2008
824 extern char *asctime_r(struct tm const *restrict, char *restrict);
825 #endif
826 
827 #ifndef HAVE_DECL_ENVIRON
828 # if defined environ || defined __USE_GNU
829 #  define HAVE_DECL_ENVIRON 1
830 # else
831 #  define HAVE_DECL_ENVIRON 0
832 # endif
833 #endif
834 
835 #if !HAVE_DECL_ENVIRON
836 extern char **environ;
837 #endif
838 
839 #ifndef HAVE_MEMPCPY
840 # if (defined mempcpy \
841       || defined __FreeBSD__ || defined __NetBSD__ || defined __linux__)
842 #  define HAVE_MEMPCPY 1
843 # else
844 #  define HAVE_MEMPCPY 0
845 # endif
846 #endif
847 #if !HAVE_MEMPCPY
848 static void *
mempcpy(void * restrict s1,void const * restrict s2,size_t n)849 mempcpy(void *restrict s1, void const *restrict s2, size_t n)
850 {
851   char *p = memcpy(s1, s2, n);
852   return p + n;
853 }
854 #endif
855 
856 #if 2 <= HAVE_TZNAME + (TZ_TIME_T || !HAVE_POSIX_DECLS)
857 extern char *tzname[];
858 #endif
859 #if 2 <= USG_COMPAT + (TZ_TIME_T || !HAVE_POSIX_DECLS)
860 extern long timezone;
861 extern int daylight;
862 #endif
863 #if 2 <= ALTZONE + (TZ_TIME_T || !HAVE_POSIX_DECLS)
864 extern long altzone;
865 #endif
866 
867 /*
868 ** The STD_INSPIRED functions are similar, but most also need
869 ** declarations if time_tz is defined.
870 */
871 
872 #ifndef STD_INSPIRED
873 # ifdef __NetBSD__
874 #  define STD_INSPIRED 1
875 # else
876 #  define STD_INSPIRED 0
877 # endif
878 #endif
879 #if STD_INSPIRED
880 # if TZ_TIME_T || !defined offtime
881 struct tm *offtime(time_t const *, long);
882 # endif
883 # if TZ_TIME_T || !defined offtime_r
884 struct tm *offtime_r(time_t const *restrict, long, struct tm *restrict);
885 # endif
886 # if TZ_TIME_T || !defined timelocal
887 time_t timelocal(struct tm *);
888 # endif
889 # if TZ_TIME_T || !defined timeoff
890 #  define EXTERN_TIMEOFF
891 # endif
892 # if TZ_TIME_T || !defined time2posix
893 time_t time2posix(time_t);
894 # endif
895 # if TZ_TIME_T || !defined posix2time
896 time_t posix2time(time_t);
897 # endif
898 #endif
899 
900 /* Infer TM_ZONE on systems where this information is known, but suppress
901    guessing if NO_TM_ZONE is defined.  Similarly for TM_GMTOFF.  */
902 #if (200809 < _POSIX_VERSION \
903      || defined __GLIBC__ \
904      || defined __tm_zone /* musl */ \
905      || defined __FreeBSD__ || defined __NetBSD__ || defined __OpenBSD__ \
906      || (defined __APPLE__ && defined __MACH__))
907 # if !defined TM_GMTOFF && !defined NO_TM_GMTOFF
908 #  define TM_GMTOFF tm_gmtoff
909 # endif
910 # if !defined TM_ZONE && !defined NO_TM_ZONE
911 #  define TM_ZONE tm_zone
912 # endif
913 #endif
914 
915 /*
916 ** Define functions that are ABI compatible with NetBSD.
917 ** What we call 'struct state' NetBSD calls
918 ** 'struct __state', but this is a private name so it doesn't matter.
919 */
920 #if NETBSD_INSPIRED
921 # ifdef _NETBSD_SOURCE
922 #  define state __state
923 # else
924 typedef struct state *timezone_t;
925 # endif
926 struct tm *localtime_rz(timezone_t restrict, time_t const *restrict,
927 			struct tm *restrict);
928 time_t mktime_z(timezone_t restrict, struct tm *restrict);
929 timezone_t tzalloc(char const *);
930 void tzfree(timezone_t);
931 # if STD_INSPIRED
932 #  if TZ_RUNTIME_LEAPS
933 #   define ATTRIBUTE_POSIX2TIME ATTRIBUTE_PURE
934 #  else
935 #   define ATTRIBUTE_POSIX2TIME ATTRIBUTE_CONST
936 #  endif
937 #  if TZ_TIME_T || !defined posix2time_z
938 ATTRIBUTE_POSIX2TIME time_t posix2time_z(timezone_t, time_t);
939 #  endif
940 #  if TZ_TIME_T || !defined time2posix_z
941 ATTRIBUTE_POSIX2TIME time_t time2posix_z(timezone_t, time_t);
942 #  endif
943 # endif
944 #endif
945 
946 /*
947 ** Finally, some convenience items.
948 */
949 
950 #define TYPE_BIT(type) (CHAR_BIT * (ptrdiff_t) sizeof(type))
951 #define TYPE_SIGNED(type) (((type) -1) < 0)
952 #define TWOS_COMPLEMENT(type) (TYPE_SIGNED (type) && (! ~ (type) -1))
953 
954 /* Minimum and maximum of two values.  Use lower case to avoid
955    naming clashes with standard include files.  */
956 #define max(a, b) ((a) > (b) ? (a) : (b))
957 #define min(a, b) ((a) < (b) ? (a) : (b))
958 
959 /* Max and min values of the integer type T, of which only the bottom
960    B bits are used, and where the highest-order used bit is considered
961    to be a sign bit if T is signed.  */
962 #define MAXVAL(t, b)						\
963   ((t) (((t) 1 << ((b) - 1 - TYPE_SIGNED(t)))			\
964 	- 1 + ((t) 1 << ((b) - 1 - TYPE_SIGNED(t)))))
965 #define MINVAL(t, b)						\
966   ((t) (TYPE_SIGNED(t) ? - TWOS_COMPLEMENT(t) - MAXVAL(t, b) : 0))
967 
968 /* The extreme time values, assuming no padding.  */
969 #define TIME_T_MIN_NO_PADDING MINVAL(time_t, TYPE_BIT(time_t))
970 #define TIME_T_MAX_NO_PADDING MAXVAL(time_t, TYPE_BIT(time_t))
971 
972 /* The extreme time values.  These are macros, not constants, so that
973    any portability problems occur only when compiling .c files that use
974    the macros, which is safer for applications that need only zdump and zic.
975    This implementation assumes no padding if time_t is signed and
976    either the compiler lacks support for _Generic or time_t is not one
977    of the standard signed integer types.  */
978 #if HAVE__GENERIC
979 # define TIME_T_MIN \
980     _Generic((time_t) 0, \
981 	     signed char: SCHAR_MIN, short: SHRT_MIN, \
982 	     int: INT_MIN, long: LONG_MIN, long long: LLONG_MIN, \
983 	     default: TIME_T_MIN_NO_PADDING)
984 # define TIME_T_MAX \
985     (TYPE_SIGNED(time_t) \
986      ? _Generic((time_t) 0, \
987 		signed char: SCHAR_MAX, short: SHRT_MAX, \
988 		int: INT_MAX, long: LONG_MAX, long long: LLONG_MAX, \
989 		default: TIME_T_MAX_NO_PADDING)			    \
990      : (time_t) -1)
991 enum { SIGNED_PADDING_CHECK_NEEDED
992 	 = _Generic((time_t) 0,
993 		    signed char: false, short: false,
994 		    int: false, long: false, long long: false,
995 		    default: true) };
996 #else
997 # define TIME_T_MIN TIME_T_MIN_NO_PADDING
998 # define TIME_T_MAX TIME_T_MAX_NO_PADDING
999 enum { SIGNED_PADDING_CHECK_NEEDED = true };
1000 #endif
1001 /* Try to check the padding assumptions.  Although TIME_T_MAX and the
1002    following check can both have undefined behavior on oddball
1003    platforms due to shifts exceeding widths of signed integers, these
1004    platforms' compilers are likely to diagnose these issues in integer
1005    constant expressions, so it shouldn't hurt to check statically.  */
1006 static_assert(! TYPE_SIGNED(time_t) || ! SIGNED_PADDING_CHECK_NEEDED
1007 	      || TIME_T_MAX >> (TYPE_BIT(time_t) - 2) == 1);
1008 
1009 /*
1010 ** 302 / 1000 is log10(2.0) rounded up.
1011 ** Subtract one for the sign bit if the type is signed;
1012 ** add one for integer division truncation;
1013 ** add one more for a minus sign if the type is signed.
1014 */
1015 #define INT_STRLEN_MAXIMUM(type) \
1016 	((TYPE_BIT(type) - TYPE_SIGNED(type)) * 302 / 1000 + \
1017 	1 + TYPE_SIGNED(type))
1018 
1019 /*
1020 ** INITIALIZE(x)
1021 */
1022 
1023 #ifdef GCC_LINT
1024 # define INITIALIZE(x)	((x) = 0)
1025 #else
1026 # define INITIALIZE(x)
1027 #endif
1028 
1029 /* Whether memory access must strictly follow the C standard.
1030    If 0, it's OK to read uninitialized storage so long as the value is
1031    not relied upon.  Defining it to 0 lets mktime access parts of
1032    struct tm that might be uninitialized, as a heuristic when the
1033    standard doesn't say what to return and when tm_gmtoff can help
1034    mktime likely infer a better value.  */
1035 #ifndef UNINIT_TRAP
1036 # define UNINIT_TRAP 0
1037 #endif
1038 
1039 /* strftime.c sometimes needs access to timeoff if it is not already public.
1040    tz_private_timeoff should be used only by localtime.c and strftime.c.  */
1041 #if (!defined EXTERN_TIMEOFF \
1042      && defined TM_GMTOFF && (200809 < _POSIX_VERSION || ! UNINIT_TRAP))
1043 # ifndef timeoff
1044 #  define timeoff tz_private_timeoff
1045 # endif
1046 # define EXTERN_TIMEOFF
1047 #endif
1048 #ifdef EXTERN_TIMEOFF
1049 time_t timeoff(struct tm *, long);
1050 #endif
1051 
1052 #ifdef DEBUG
1053 # undef unreachable
1054 # define unreachable() abort()
1055 #elif !defined unreachable
1056 # ifdef __has_builtin
1057 #  if __has_builtin(__builtin_unreachable)
1058 #   define unreachable() __builtin_unreachable()
1059 #  endif
1060 # elif 4 < __GNUC__ + (5 <= __GNUC_MINOR__)
1061 #  define unreachable() __builtin_unreachable()
1062 # endif
1063 # ifndef unreachable
1064 #  define unreachable() ((void) 0)
1065 # endif
1066 #endif
1067 
1068 /*
1069 ** For the benefit of GNU folk...
1070 ** '_(MSGID)' uses the current locale's message library string for MSGID.
1071 ** The default is to use gettext if available, and use MSGID otherwise.
1072 */
1073 
1074 #if HAVE_GETTEXT
1075 # define _(msgid) gettext(msgid)
1076 #else /* !HAVE_GETTEXT */
1077 # define _(msgid) (msgid)
1078 #endif /* !HAVE_GETTEXT */
1079 #define N_(msgid) (msgid)
1080 
1081 #if !defined TZ_DOMAIN && defined HAVE_GETTEXT
1082 # define TZ_DOMAIN "tz"
1083 #endif
1084 
1085 #if HAVE_INCOMPATIBLE_CTIME_R
1086 # undef asctime_r
1087 # undef ctime_r
1088 char *asctime_r(struct tm const *restrict, char *restrict);
1089 char *ctime_r(time_t const *, char *);
1090 #endif /* HAVE_INCOMPATIBLE_CTIME_R */
1091 
1092 /* Handy constants that are independent of tzfile implementation.  */
1093 
1094 /* 2**31 - 1 as a signed integer, and usable in #if.  */
1095 #define TWO_31_MINUS_1 2147483647
1096 
1097 enum {
1098   SECSPERMIN = 60,
1099   MINSPERHOUR = 60,
1100   SECSPERHOUR = SECSPERMIN * MINSPERHOUR,
1101   HOURSPERDAY = 24,
1102   DAYSPERWEEK = 7,
1103   DAYSPERNYEAR = 365,
1104   DAYSPERLYEAR = DAYSPERNYEAR + 1,
1105   MONSPERYEAR = 12,
1106   YEARSPERREPEAT = 400	/* years before a Gregorian repeat */
1107 };
1108 
1109 #define SECSPERDAY	((int_fast32_t) SECSPERHOUR * HOURSPERDAY)
1110 
1111 #define DAYSPERREPEAT		((int_fast32_t) 400 * 365 + 100 - 4 + 1)
1112 #define SECSPERREPEAT		((int_fast64_t) DAYSPERREPEAT * SECSPERDAY)
1113 #define AVGSECSPERYEAR		(SECSPERREPEAT / YEARSPERREPEAT)
1114 
1115 /* How many years to generate (in zic.c) or search through (in localtime.c).
1116    This is two years larger than the obvious 400, to avoid edge cases.
1117    E.g., suppose a rule applies from 2012 on with transitions
1118    in March and September, plus one-off transitions in November 2013,
1119    and suppose the rule cannot be expressed as a proleptic TZ string.
1120    If zic looked only at the last 400 years, it would set max_year=2413,
1121    with the intent that the 400 years 2014 through 2413 will be repeated.
1122    The last transition listed in the tzfile would be in 2413-09,
1123    less than 400 years after the last one-off transition in 2013-11.
1124    Two years is not overkill for localtime.c, as a one-year bump
1125    would mishandle 2023d's America/Ciudad_Juarez for November 2422.  */
1126 enum { years_of_observations = YEARSPERREPEAT + 2 };
1127 
1128 enum {
1129   TM_SUNDAY,
1130   TM_MONDAY,
1131   TM_TUESDAY,
1132   TM_WEDNESDAY,
1133   TM_THURSDAY,
1134   TM_FRIDAY,
1135   TM_SATURDAY
1136 };
1137 
1138 enum {
1139   TM_JANUARY,
1140   TM_FEBRUARY,
1141   TM_MARCH,
1142   TM_APRIL,
1143   TM_MAY,
1144   TM_JUNE,
1145   TM_JULY,
1146   TM_AUGUST,
1147   TM_SEPTEMBER,
1148   TM_OCTOBER,
1149   TM_NOVEMBER,
1150   TM_DECEMBER
1151 };
1152 
1153 enum {
1154   TM_YEAR_BASE = 1900,
1155   TM_WDAY_BASE = TM_MONDAY,
1156   EPOCH_YEAR = 1970,
1157   EPOCH_WDAY = TM_THURSDAY
1158 };
1159 
1160 #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
1161 
1162 /*
1163 ** Since everything in isleap is modulo 400 (or a factor of 400), we know that
1164 **	isleap(y) == isleap(y % 400)
1165 ** and so
1166 **	isleap(a + b) == isleap((a + b) % 400)
1167 ** or
1168 **	isleap(a + b) == isleap(a % 400 + b % 400)
1169 ** This is true even if % means modulo rather than Fortran remainder
1170 ** (which is allowed by C89 but not by C99 or later).
1171 ** We use this to avoid addition overflow problems.
1172 */
1173 
1174 #define isleap_sum(a, b)	isleap((a) % 400 + (b) % 400)
1175 
1176 #endif /* !defined PRIVATE_H */
1177