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musl/include/limits.h

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initial check-in, version 0.5.0
2011-02-12 05:22:29 +00:00
#ifndef _LIMITS_H
#define _LIMITS_H
default features: make musl usable without feature test macros the old behavior of exposing nothing except plain ISO C can be obtained by defining __STRICT_ANSI__ or using a compiler option (such as -std=c99) that predefines it. the new default featureset is POSIX with XSI plus _BSD_SOURCE. any explicit feature test macros will inhibit the default. installation docs have also been updated to reflect this change.
2012-09-08 03:13:55 +00:00
#include <features.h>
define LONG_MAX via arch alltypes.h, strip down bits/limits.h LLONG_MAX is uniform for all archs we support and plenty of header and code level logic assumes it is, so it does not make sense for limits.h bits mechanism to pretend it's variable. LONG_BIT can be defined in terms of LONG_MAX; there's no reason to put it in bits. by moving LONG_MAX definition to __LONG_MAX in alltypes.h and moving LLONG_MAX out of bits, there are now no plain-C limits that are defined in the bits header, so the bits header only needs to be included in the POSIX or extended profiles. this allows the feature test macro logic to be removed from the bits header, facilitating a long-term goal of getting such logic out of bits. having __LONG_MAX in alltypes.h will allow further generalization of headers. archs without a constant PAGESIZE no longer need bits/limits.h at all.
2019-10-17 23:19:40 +00:00
#include <bits/alltypes.h> /* __LONG_MAX */
initial check-in, version 0.5.0
2011-02-12 05:22:29 +00:00
limits.h: support gcc's -funsigned-char some software apparently uses this and breaks with musl due to mismatching definitions...
2012-03-21 01:10:06 +00:00
/* Support signed or unsigned plain-char */
fix dubious char signedness check in limits.h commit 201995f382cc698ae19289623cc06a70048ffe7b introduced a hack utilizing the signedness of character constants at the preprocessor level to avoid depending on the gcc-specific __CHAR_UNSIGNED__ predef. while this trick works on gcc and presumably other compilers being used, it's not clear that the behavior it depends on is actually conforming. C11 6.4.4.4 ¶10 defines character constants as having type int, and 6.10.1 ¶4 defines preprocessor #if arithmetic to take place in intmax_t or uintmax_t, depending on the signedness of the integer operand types, and it is specified that "this includes interpreting character constants". if character literals had type char and just promoted to int, it would be clear that when char is unsigned they should behave as uintmax_t at the preprocessor level. however, as written the text of the standard seems to require that character constants always behave as intmax_t, corresponding to int, at the preprocessor level. since there is a good deal of ambiguity about the correct behavior and a risk that compilers will disagree or that an interpretation may mandate a change in the behavior, do not rely on it for defining CHAR_MIN and CHAR_MAX correctly. instead, use the signedness of the value (as opposed to the type) of '\xff', which will be positive if and only if plain char is unsigned. this behavior is clearly specified, and the specific case '\xff' is even used in an example, under 6.4.4.4 of the standard.
2018-08-28 17:54:50 +00:00
#if '\xff' > 0
limits.h: support gcc's -funsigned-char some software apparently uses this and breaks with musl due to mismatching definitions...
2012-03-21 01:10:06 +00:00
#define CHAR_MIN 0
#define CHAR_MAX 255
#else
#define CHAR_MIN (-128)
#define CHAR_MAX 127
#endif
initial check-in, version 0.5.0
2011-02-12 05:22:29 +00:00
#define CHAR_BIT 8
#define SCHAR_MIN (-128)
#define SCHAR_MAX 127
#define UCHAR_MAX 255
move all limits that don't vary out of bits/limits.h, into main limits.h
2011-06-25 19:38:00 +00:00
#define SHRT_MIN (-1-0x7fff)
#define SHRT_MAX 0x7fff
#define USHRT_MAX 0xffff
#define INT_MIN (-1-0x7fffffff)
#define INT_MAX 0x7fffffff
#define UINT_MAX 0xffffffffU
#define LONG_MIN (-LONG_MAX-1)
define LONG_MAX via arch alltypes.h, strip down bits/limits.h LLONG_MAX is uniform for all archs we support and plenty of header and code level logic assumes it is, so it does not make sense for limits.h bits mechanism to pretend it's variable. LONG_BIT can be defined in terms of LONG_MAX; there's no reason to put it in bits. by moving LONG_MAX definition to __LONG_MAX in alltypes.h and moving LLONG_MAX out of bits, there are now no plain-C limits that are defined in the bits header, so the bits header only needs to be included in the POSIX or extended profiles. this allows the feature test macro logic to be removed from the bits header, facilitating a long-term goal of getting such logic out of bits. having __LONG_MAX in alltypes.h will allow further generalization of headers. archs without a constant PAGESIZE no longer need bits/limits.h at all.
2019-10-17 23:19:40 +00:00
#define LONG_MAX __LONG_MAX
move all limits that don't vary out of bits/limits.h, into main limits.h
2011-06-25 19:38:00 +00:00
#define ULONG_MAX (2UL*LONG_MAX+1)
#define LLONG_MIN (-LLONG_MAX-1)
define LONG_MAX via arch alltypes.h, strip down bits/limits.h LLONG_MAX is uniform for all archs we support and plenty of header and code level logic assumes it is, so it does not make sense for limits.h bits mechanism to pretend it's variable. LONG_BIT can be defined in terms of LONG_MAX; there's no reason to put it in bits. by moving LONG_MAX definition to __LONG_MAX in alltypes.h and moving LLONG_MAX out of bits, there are now no plain-C limits that are defined in the bits header, so the bits header only needs to be included in the POSIX or extended profiles. this allows the feature test macro logic to be removed from the bits header, facilitating a long-term goal of getting such logic out of bits. having __LONG_MAX in alltypes.h will allow further generalization of headers. archs without a constant PAGESIZE no longer need bits/limits.h at all.
2019-10-17 23:19:40 +00:00
#define LLONG_MAX 0x7fffffffffffffffLL
move all limits that don't vary out of bits/limits.h, into main limits.h
2011-06-25 19:38:00 +00:00
#define ULLONG_MAX (2ULL*LLONG_MAX+1)
initial check-in, version 0.5.0
2011-02-12 05:22:29 +00:00
#define MB_LEN_MAX 4
begin namespace-cleanup of standard C headers
2011-02-14 10:10:10 +00:00
#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
fix missing limits when only _BSD_SOURCE is defined the missing check did not affect the default profile, since it has both _XOPEN_SOURCE and _BSD_SOURCE defined, but it did break programs which explicitly define _BSD_SOURCE, causing it to be the only feature test macro present.
2012-11-26 17:05:33 +00:00
|| defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
begin namespace-cleanup of standard C headers
2011-02-14 10:10:10 +00:00
define LONG_MAX via arch alltypes.h, strip down bits/limits.h LLONG_MAX is uniform for all archs we support and plenty of header and code level logic assumes it is, so it does not make sense for limits.h bits mechanism to pretend it's variable. LONG_BIT can be defined in terms of LONG_MAX; there's no reason to put it in bits. by moving LONG_MAX definition to __LONG_MAX in alltypes.h and moving LLONG_MAX out of bits, there are now no plain-C limits that are defined in the bits header, so the bits header only needs to be included in the POSIX or extended profiles. this allows the feature test macro logic to be removed from the bits header, facilitating a long-term goal of getting such logic out of bits. having __LONG_MAX in alltypes.h will allow further generalization of headers. archs without a constant PAGESIZE no longer need bits/limits.h at all.
2019-10-17 23:19:40 +00:00
#include <bits/limits.h>
move all limits that don't vary out of bits/limits.h, into main limits.h
2011-06-25 19:38:00 +00:00
#define PIPE_BUF 4096
#define FILESIZEBITS 64
#define NAME_MAX 255
#define PATH_MAX 4096
#define NGROUPS_MAX 32
#define ARG_MAX 131072
#define IOV_MAX 1024
#define SYMLOOP_MAX 40
#define WORD_BIT 32
begin namespace-cleanup of standard C headers
2011-02-14 10:10:10 +00:00
#define SSIZE_MAX LONG_MAX
initial check-in, version 0.5.0
2011-02-12 05:22:29 +00:00
#define TZNAME_MAX 6
increase TTY_NAME_MAX limit to 32 the old value of 20 was reported by Laurent Bercot as being insufficient for a reasonable real-world usage case. actual problem was the internal buffer used by ttyname(), but the implementation of ttyname uses TTY_NAME_MAX, and for consistency it's best to increase both. the new value is aligned with glibc.
2013-11-29 17:45:09 +00:00
#define TTY_NAME_MAX 32
initial check-in, version 0.5.0
2011-02-12 05:22:29 +00:00
#define HOST_NAME_MAX 255
define LONG_MAX via arch alltypes.h, strip down bits/limits.h LLONG_MAX is uniform for all archs we support and plenty of header and code level logic assumes it is, so it does not make sense for limits.h bits mechanism to pretend it's variable. LONG_BIT can be defined in terms of LONG_MAX; there's no reason to put it in bits. by moving LONG_MAX definition to __LONG_MAX in alltypes.h and moving LLONG_MAX out of bits, there are now no plain-C limits that are defined in the bits header, so the bits header only needs to be included in the POSIX or extended profiles. this allows the feature test macro logic to be removed from the bits header, facilitating a long-term goal of getting such logic out of bits. having __LONG_MAX in alltypes.h will allow further generalization of headers. archs without a constant PAGESIZE no longer need bits/limits.h at all.
2019-10-17 23:19:40 +00:00
#if LONG_MAX == 0x7fffffffL
#define LONG_BIT 32
#else
#define LONG_BIT 64
#endif
initial check-in, version 0.5.0
2011-02-12 05:22:29 +00:00
/* Implementation choices... */
pthread stack treatment overhaul for application-provided stacks, etc. the main goal of these changes is to address the case where an application provides a stack of size N, but TLS has size M that's a significant portion of the size N (or even larger than N), thus giving the application less stack space than it expected or no stack at all! the new strategy pthread_create now uses is to only put TLS on the application-provided stack if TLS is smaller than 1/8 of the stack size or 2k, whichever is smaller. this ensures that the application always has "close enough" to what it requested, and the threshold is chosen heuristically to make sure "sane" amounts of TLS still end up in the application-provided stack. if TLS does not fit the above criteria, pthread_create uses mmap to obtain space for TLS, but still uses the application-provided stack for actual call frame stack. this is to avoid wasting memory, and for the sake of supporting ugly hacks like garbage collection based on assumptions that the implementation will use the provided stack range. in order for the above heuristics to ever succeed, the amount of TLS space wasted on POSIX TSD (pthread_key_create based) needed to be reduced. otherwise, these changes would preclude any use of pthread_create without mmap, which would have serious memory usage and performance costs for applications trying to create huge numbers of threads using pre-allocated stack space. the new value of PTHREAD_KEYS_MAX is the minimum allowed by POSIX, 128. this should still be plenty more than real-world applications need, especially now that C11/gcc-style TLS is now supported in musl, and most apps and libraries choose to use that instead of POSIX TSD when available. at the same time, PTHREAD_STACK_MIN has been decreased. it was originally set to PAGE_SIZE back when there was no support for TLS or application-provided stacks, and requests smaller than a whole page did not make sense. now, there are two good reasons to support requests smaller than a page: (1) applications could provide pre-allocated stacks smaller than a page, and (2) with smaller stack sizes, stack+TLS+TSD can all fit in one page, making it possible for applications which need huge numbers of threads with minimal stack needs to allocate exactly one page per thread. the new value of PTHREAD_STACK_MIN, 2k, is aligned with the minimum size for sigaltstack.
2013-02-02 03:10:40 +00:00
#define PTHREAD_KEYS_MAX 128
#define PTHREAD_STACK_MIN 2048
reorganize thread exit code, make pthread_exit call cancellation handlers (pt2)
2011-02-14 00:58:30 +00:00
#define PTHREAD_DESTRUCTOR_ITERATIONS 4
preliminaries to adding POSIX semaphores
2011-03-03 23:32:26 +00:00
#define SEM_VALUE_MAX 0x7fffffff
fix sem_open and sem_close to obey posix semantics multiple opens of the same named semaphore must return the same pointer, and only the last close can unmap it. thus the ugly global state keeping track of mappings. the maximum number of distinct named semaphores that can be opened is limited sufficiently small that the linear searches take trivial time, especially compared to the syscall overhead of these functions.
2011-03-11 02:34:19 +00:00
#define SEM_NSEMS_MAX 256
implement POSIX timers this implementation is superior to the glibc/nptl implementation, in that it gives true realtime behavior. there is no risk of timer expiration events being lost due to failed thread creation or failed malloc, because the thread is created as time creation time, and reused until the timer is deleted.
2011-03-29 17:01:25 +00:00
#define DELAYTIMER_MAX 0x7fffffff
define MQ_PRIO_MAX
2011-06-07 19:05:04 +00:00
#define MQ_PRIO_MAX 32768
missing limit LOGIN_NAME_MAX
2012-05-14 04:01:48 +00:00
#define LOGIN_NAME_MAX 256
initial check-in, version 0.5.0
2011-02-12 05:22:29 +00:00
/* Arbitrary numbers... */
#define BC_BASE_MAX 99
#define BC_DIM_MAX 2048
#define BC_SCALE_MAX 99
#define BC_STRING_MAX 1000
#define CHARCLASS_NAME_MAX 14
#define COLL_WEIGHTS_MAX 2
#define EXPR_NEST_MAX 32
#define LINE_MAX 4096
#define RE_DUP_MAX 255
#define NL_ARGMAX 9
#define NL_MSGMAX 32767
#define NL_SETMAX 255
#define NL_TEXTMAX 2048
extensive header cleanup for standards conformance & correctness thanks to Peter Mazinger (psm) for pointing many of these issues out and submitting a patch on which this commit is loosely based
2011-02-14 23:41:25 +00:00
#endif
fix minor namespace issues in limits.h PAGE_SIZE, NZERO, and NL_LANGMAX are XSI-shaded.
2018-03-10 22:53:27 +00:00
#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE) || defined(_XOPEN_SOURCE)
#ifdef PAGESIZE
#define PAGE_SIZE PAGESIZE
#endif
#define NZERO 20
#define NL_LANGMAX 32
#endif
fix multiple minor namespace issues in headers fcntl.h: AT_* is not a reserved namespace so extensions cannot be exposed by default. langinfo.h: YESSTR and NOSTR were removed from the standard. limits.h: NL_NMAX was removed from the standard. signal.h: the conditional for NSIG was wrongly checking _XOPEN_SOURCE rather than _BSD_SOURCE. this was purely a mistake; it doesn't even match the commit message from the commit that added it.
2013-10-21 02:01:51 +00:00
#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE) \
|| (defined(_XOPEN_SOURCE) && _XOPEN_SOURCE+0 < 700)
#define NL_NMAX 16
#endif
initial check-in, version 0.5.0
2011-02-12 05:22:29 +00:00
/* POSIX/SUS requirements follow. These numbers come directly
* from SUS and have nothing to do with the host system. */
#define _POSIX_AIO_LISTIO_MAX 2
#define _POSIX_AIO_MAX 1
#define _POSIX_ARG_MAX 4096
#define _POSIX_CHILD_MAX 25
extensive header cleanup for standards conformance & correctness thanks to Peter Mazinger (psm) for pointing many of these issues out and submitting a patch on which this commit is loosely based
2011-02-14 23:41:25 +00:00
#define _POSIX_CLOCKRES_MIN 20000000
initial check-in, version 0.5.0
2011-02-12 05:22:29 +00:00
#define _POSIX_DELAYTIMER_MAX 32
#define _POSIX_HOST_NAME_MAX 255
#define _POSIX_LINK_MAX 8
#define _POSIX_LOGIN_NAME_MAX 9
#define _POSIX_MAX_CANON 255
#define _POSIX_MAX_INPUT 255
#define _POSIX_MQ_OPEN_MAX 8
#define _POSIX_MQ_PRIO_MAX 32
#define _POSIX_NAME_MAX 14
#define _POSIX_NGROUPS_MAX 8
#define _POSIX_OPEN_MAX 20
#define _POSIX_PATH_MAX 256
#define _POSIX_PIPE_BUF 512
#define _POSIX_RE_DUP_MAX 255
#define _POSIX_RTSIG_MAX 8
#define _POSIX_SEM_NSEMS_MAX 256
#define _POSIX_SEM_VALUE_MAX 32767
#define _POSIX_SIGQUEUE_MAX 32
#define _POSIX_SSIZE_MAX 32767
#define _POSIX_STREAM_MAX 8
#define _POSIX_SS_REPL_MAX 4
#define _POSIX_SYMLINK_MAX 255
#define _POSIX_SYMLOOP_MAX 8
#define _POSIX_THREAD_DESTRUCTOR_ITERATIONS 4
#define _POSIX_THREAD_KEYS_MAX 128
#define _POSIX_THREAD_THREADS_MAX 64
#define _POSIX_TIMER_MAX 32
#define _POSIX_TRACE_EVENT_NAME_MAX 30
#define _POSIX_TRACE_NAME_MAX 8
#define _POSIX_TRACE_SYS_MAX 8
#define _POSIX_TRACE_USER_EVENT_MAX 32
#define _POSIX_TTY_NAME_MAX 9
#define _POSIX_TZNAME_MAX 6
#define _POSIX2_BC_BASE_MAX 99
#define _POSIX2_BC_DIM_MAX 2048
#define _POSIX2_BC_SCALE_MAX 99
#define _POSIX2_BC_STRING_MAX 1000
#define _POSIX2_CHARCLASS_NAME_MAX 14
#define _POSIX2_COLL_WEIGHTS_MAX 2
#define _POSIX2_EXPR_NEST_MAX 32
#define _POSIX2_LINE_MAX 2048
#define _POSIX2_RE_DUP_MAX 255
#define _XOPEN_IOV_MAX 16
#define _XOPEN_NAME_MAX 255
#define _XOPEN_PATH_MAX 1024
#endif