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2022-10-19remove LFS64 programming interfaces (macro-only) from _GNU_SOURCERich Felker-1/+1
these badly pollute the namespace with macros whenever _GNU_SOURCE is defined, which is always the case with g++, and especially tends to interfere with C++ constructs. as our implementation of these was macro-only, their removal cannot affect any existing binaries. at the source level, portable software should be prepared for them not to exist. for now, they are left in place with explicit _LARGEFILE64_SOURCE. this provides an easy temporary path for integrators/distributions to get packages building again right away if they break while working on a proper, upstreamable fix. the intent is that this be a very short-term measure and that the macros be removed entirely in the next release cycle.
2022-08-26add sysconf keys/values for signal stack sizeRich Felker-0/+2
as a result of ISA extensions exploding register file sizes on some archs, using a constant for minimum signal stack size no longer seems viably future-proof. add sysconf keys allowing the kernel to provide a machine-dependent minimum applications can query to ensure they allocate sufficient space for stacks. the key names and indices align with the same functionality in glibc. see commit d5a5045382315e36588ca225889baa36ed0ed38f for previous action on this subject. ultimately, the macros MINSIGSTKSZ and SIGSTKSZ probably need to be deprecated, but that is standards-amendment work outside the scope of a single implementation.
2022-04-20add missing POSIX confstr keys for pthread CFLAGS/LDFLAGSRich Felker-0/+2
_CS_POSIX_V7_THREADS_CFLAGS and _CS_POSIX_V7_THREADS_LDFLAGS have been missing for a long time, which is a conformance defect. we were waiting on glibc to add them or at least agree on the numeric values they will have so as to keep the numbering aligned. it looks like they will be added to glibc with these numbers, and in any case, this list does not have any significant churn that would result in the numbers getting taken.
2022-01-09add SEEK_DATA and SEEK_HOLE to unistd.hÉrico Nogueira-0/+2
these are linux specific constants. glibc exposes them behind _GNU_SOURCE, but, since SEEK_* is reserved for the implementation, we can simply define them. furthermore, since they can't be used with fseek() and other functions that deal with FILE, we don't add them to stdio.h.
2021-11-29define NULL as nullptr when used in C++11 or laterIsmael Luceno-1/+3
This should be safer for casting and more compatible with existing code bases that wrongly assume it must be defined as a pointer.
2020-10-14implement _Fork and refactor fork using itRich Felker-0/+1
the _Fork interface is defined for future issue of POSIX as the outcome of Austin Group issue 62, which drops the AS-safety requirement for fork, and provides an AS-safe replacement that does not run the registered atfork handlers.
2020-08-17add gettid functionRich Felker-0/+1
this is a prerequisite for addition of other interfaces that use kernel tids, including futex and SIGEV_THREAD_ID. there is some ambiguity as to whether the semantic return type should be int or pid_t. either way, futex API imposes a contract that the values fit in int (excluding some upper reserved bits). glibc used pid_t, so in the interest of not having gratuitous mismatch (the underlying types are the same anyway), pid_t is used here as well. while conceptually this is a syscall, the copy stored in the thread structure is always valid in all contexts where it's valid to call libc functions, so it's used to avoid the syscall.
2019-08-30add public declaration for optreset under appropriate feature profilesRich Felker-0/+1
commit 030e52639248ac8417a4934298caa78c21a228d1 added optreset, a BSD extension to getopt duplicating the functionality (also an extension) of setting optind to 0, but failed to provide a public declaration for it. according to the BSD documentation and headers, the application is not supposed to need to provide its own declaration.
2019-08-23add copy_file_range system call wrapperÁrni Dagur-0/+1
2018-03-10fix minor namespace issue in unistd.hRich Felker-2/+1
the F_* macros associated with the lockf function are XSI-shaded (like the lockf function itself) and should only be exposed when the function is.
2018-02-23add getentropy functionRich Felker-0/+1
based loosely on patch by Hauke Mehrtens; converted to wrap the public API of the underlying getrandom function rather than direct syscalls, so that if/when a fallback implementation of getrandom is added it will automatically get picked up by getentropy too.
2016-10-20fix various header namespace issues under feature-test-macro controlRich Felker-2/+2
reported and changes suggested by Daniel Sabogal.
2016-10-20add missing confstr constantsDaniel Sabogal-0/+2
the _CS_V6_ENV and _CS_V7_ENV constants are required to be available for use with confstr. glibc defines these constants with values 1148 and 1149, respectively. the only missing (and required) confstr constants are _CS_POSIX_V7_THREADS_CFLAGS and _CS_POSIX_V7_THREADS_LDFLAGS which remain unavailable in glibc.
2015-07-09fix incorrect void return type for syncfs functionRich Felker-1/+1
being nonstandard, the closest thing to a specification for this function is its man page, which documents it as returning int. it can fail with EBADF if the file descriptor passed is invalid.
2014-09-10fix places where _BSD_SOURCE failed to yield a superset of _XOPEN_SOURCERich Felker-3/+0
the vast majority of these failures seem to have been oversights at the time _BSD_SOURCE was added, or perhaps shortly afterward. the one which may have had some reason behind it is omission of setpgrp from the _BSD_SOURCE feature profile, since the standard setpgrp interface conflicts with a legacy (pre-POSIX) BSD interface by the same name. however, such omission is not aligned with our general policy in this area (for example, handling of similar _GNU_SOURCE cases) and should not be preserved.
2014-07-19add issetugid function to check for elevated privilegeBrent Cook-0/+1
this function provides a way for third-party library code to use the same logic that's used internally in libc for suppressing untrusted input/state (e.g. the environment) when the application is running with privleges elevated by the setuid or setgid bit or some other mechanism. its semantics are intended to match the openbsd function by the same name. there was some question as to whether this function is necessary: getauxval(AT_SECURE) was proposed as an alternative. however, this has several drawbacks. the most obvious is that it asks programmers to be aware of an implementation detail of ELF-based systems (the aux vector) rather than simply the semantic predicate to be checked. and trying to write a safe, reliable version of issetugid in terms of getauxval is difficult. for example, early versions of the glibc getauxval did not report ENOENT, which could lead to false negatives if AT_SECURE was not present in the aux vector (this could probably only happen when running on non-linux kernels under linux emulation, since glibc does not support linux versions old enough to lack AT_SECURE). as for musl, getauxval has always properly reported errors, but prior to commit 7bece9c2095ee81f14b1088f6b0ba2f37fecb283, the musl implementation did not emulate AT_SECURE if missing, which would result in a false positive. since musl actually does partially support kernels that lack AT_SECURE, this was problematic. the intent is that library authors will use issetugid if its availability is detected at build time, and only fall back to the unreliable alternatives on systems that lack it. patch by Brent Cook. commit message/rationale by Rich Felker.
2014-05-19remove unsupported nonstandard sysconf macros and their table entriesRich Felker-60/+0
some of these may have been from ancient (pre-SUSv2) POSIX versions; more likely, they were from POSIX drafts or glibc interpretations of what ancient versions of POSIX should have added (instead they made they described functionality mandatory and/or dropped it completely). others are purely glibc-isms, many of them ill-thought-out, like providing ways to lookup the min/max values of types at runtime (despite the impossibility of them changing at runtime and the impossibility of representing ULONG_MAX in a return value of type long). since our sysconf implementation does not support or return meaningful values for any of these, it's harmful to have the macros around; applications' build scripts may detect and attempt to use them, only to get -1/EINVAL as a result. if removing them does break some applications, and it's determined that the usage was reasonable, some of these could be added back on an as-needed basis, but they should return actual meaningful values, not junk like they were returning before.
2014-04-20expose public execvpe interfaceM Farkas-Dyck-0/+1
2013-12-06add posix_close, accepted for inclusion in the next issue of POSIXRich Felker-0/+3
this is purely a wrapper for close since Linux does not support EINTR semantics for the close syscall.
2013-11-24restore type of NULL to void * except when used in C++ programsRich Felker-0/+4
unfortunately this eliminates the ability of the compiler to diagnose some dangerous/incorrect usage, but POSIX requires (as an extension to the C language, i.e. CX shaded) that NULL have type void *. plain C allows it to be defined as any null pointer constant. the definition 0L is preserved for C++ rather than reverting to plain 0 to avoid dangerous behavior in non-conforming programs which use NULL as a variadic sentinel. (it's impossible to use (void *)0 for C++ since C++ lacks the proper implicit pointer conversions, and other popular alternatives like the GCC __null extension seem non-conforming to the standard's requirements.)
2013-08-03add prototypes for euidaccess/eaccessRich Felker-0/+2
2013-07-27a few more fixes for unistd/sysconf feature reportingRich Felker-0/+1
2013-07-26report presence of ADV and MSG options in unistd.h and sysconfRich Felker-0/+2
2013-07-26report that posix_spawn is supported in unistd.h and sysconfRich Felker-0/+1
2013-06-26document in sysconf and unistd.h that per-thread cpu clocks existRich Felker-0/+1
2013-04-02re-add useconds_trofl0r-0/+1
this type was removed back in 5243e5f1606a9c6fcf01414e , because it was removed from the XSI specs. however some apps use it. since it's in the POSIX reserved namespace, we can expose it unconditionally.
2013-01-18use a common definition of NULL as 0L for C and C++Rich Felker-6/+1
the historical mess of having different definitions for C and C++ comes from the historical C definition as (void *)0 and the fact that (void *)0 can't be used in C++ because it does not convert to other pointer types implicitly. however, using plain 0 in C++ exposed bugs in C++ programs that call variadic functions with NULL as an argument and (wrongly; this is UB) expect it to arrive as a null pointer. on 64-bit machines, the high bits end up containing junk. glibc dodges the issue by using a GCC extension __null to define NULL; this is observably non-conforming because a conforming application could observe the definition of NULL via stringizing and see that it is neither an integer constant expression with value zero nor such an expression cast to void. switching to 0L eliminates the issue and provides compatibility with broken applications, since on all musl targets, long and pointers have the same size, representation, and argument-passing convention. we could maintain separate C and C++ definitions of NULL (i.e. just use 0L on C++ and use (void *)0 on C) but after careful analysis, it seems extremely difficult for a C program to even determine whether NULL has integer or pointer type, much less depend in subtle, unintentional ways, on whether it does. C89 seems to have no way to make the distinction. on C99, the fact that (int)(void *)0 is not an integer constant expression, along with subtle VLA/sizeof semantics, can be used to make the distinction, but many compilers are non-conforming and give the wrong result to this test anyway. on C11, _Generic can trivially make the distinction, but it seems unlikely that code targetting C11 would be so backwards in caring which definition of NULL an implementation uses. as such, the simplest path of using the same definition for NULL in both C and C++ was chosen. the #undef directive was also removed so that the compiler can catch and give a warning or error on redefinition if buggy programs have defined their own versions of NULL prior to inclusion of standard headers.
2012-12-10syscall() declaration belongs in unistd.h, not sys/syscall.hRich Felker-0/+1
traditionally, both BSD and GNU systems have it this way. sys/syscall.h is purely syscall number macros. presently glibc exposes the syscall declaration in unistd.h only with _GNU_SOURCE, but that does not reflect historical practice.
2012-12-06unistd.h: fix wrong type for gid_t argumentrofl0r-1/+1
the prototype is defined with const gid_t* rather than const gid_t[]. it was already correctly defined in grp.h.
2012-11-11report support of TPS option in unistd.h and sysconfRich Felker-0/+1
also update another newish feature in sysconf, stackaddr
2012-11-01avoid breakage if somebody wrongly defines empty feature test macrosRich Felker-1/+1
2012-09-30define some _POSIX_* macros that were omitted; required for XSI conformanceRich Felker-0/+3
2012-09-29always expose dup3 and pipe2Rich Felker-2/+2
they will be in the next version of POSIX
2012-09-16add clock_adjtime, remap_file_pages, and syncfs syscall wrappersRich Felker-0/+1
patch by Justin Cormack, with slight modification
2012-09-09add setdomainname syscall, fix getdomainname (previously a stub)Rich Felker-0/+1
2012-09-08add acct, accept4, setns, and dup3 syscalls (linux extensions)Rich Felker-0/+2
based on patch by Justin Cormack
2012-09-07default features: make musl usable without feature test macrosRich Felker-12/+1
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.
2012-09-06further use of _Noreturn, for non-plain-C functionsRich Felker-1/+8
note that POSIX does not specify these functions as _Noreturn, because POSIX is aligned with C99, not the new C11 standard. when POSIX is eventually updated to C11, it will almost surely give these functions the _Noreturn attribute. for now, the actual _Noreturn keyword is not used anyway when compiling with a c99 compiler, which is what POSIX requires; the GCC __attribute__ is used instead if it's available, however. in a few places, I've added infinite for loops at the end of _Noreturn functions to silence compiler warnings. presumably __buildin_unreachable could achieve the same thing, but it would only work on newer GCCs and would not be portable. the loops should have near-zero code size cost anyway. like the previous _Noreturn commit, this one is based on patches contributed by philomath.
2012-09-06use restrict everywhere it's required by c99 and/or posix 2008Rich Felker-3/+9
to deal with the fact that the public headers may be used with pre-c99 compilers, __restrict is used in place of restrict, and defined appropriately for any supported compiler. we also avoid the form [restrict] since older versions of gcc rejected it due to a bug in the original c99 standard, and instead use the form *restrict.
2012-08-15improve headers to better deal with removed-in-posix-2008 featuresRich Felker-2/+6
with this patch, setting _POSIX_SOURCE, or setting _POSIX_C_SOURCE or _XOPEN_SOURCE to an old version, will bring back the interfaces that were removed in POSIX 2008 - at least the ones i've covered so far, which are gethostby*, usleep, and ualarm. if there are other functions still in widespread use that were removed for which similar changes would be beneficial, they can be added just like this.
2012-07-23add pipe2 syscallRich Felker-0/+1
based on patch by orc and Isaac Dunham, with some details fixed.
2012-06-04_GNU_SOURCE is supposed to imply _LARGEFILE64_SOURCERich Felker-1/+1
this is ugly and stupid, but now that the *64 symbol names exist, a lot of broken GNU software detects them in configure, then either breaks during build due to missing off64_t definition, or attempts to compile without function declarations/prototypes. "fixing" it here is easier than telling everyone to add yet another feature test macro to their builds.
2012-06-02declare environ in unistd.h when _GNU_SOURCE feature test macro is usedRich Felker-0/+1
lots of broken programs expect this, and it's gotten to the point of being a troubleshooting FAQ topic. best to just fix it.
2012-05-22remove everything related to forkallRich Felker-1/+0
i made a best attempt, but the intended semantics of this function are fundamentally contradictory. there is no consistent way to handle ownership of locks when forking a multi-threaded process. the code could have worked by accident for programs that only used normal mutexes and nothing else (since they don't actually store or care about their owner), but that's about it. broken-by-design interfaces that aren't even in glibc (only solaris) don't belong in musl.
2012-05-22some feature test fixes for unistd.hRich Felker-16/+16
2012-05-22_GNU_SOURCE implies all BSD features except ones GNU rejectsRich Felker-1/+1
2012-05-22various header cleanups, some related to _BSD_SOURCE additionRich Felker-11/+4
there is no reason to avoid multiple identical macro definitions; this is perfectly legal C, and even with the maximal warning options enabled, gcc does not issue any warning for it.
2012-05-22support _BSD_SOURCE feature test macroRich Felker-3/+17
patch by Isaac Dunham. matched closely (maybe not exact) to glibc's idea of what _BSD_SOURCE should make visible.
2012-05-20move getpass decl to the right placeRich Felker-0/+1
2012-05-04add support for ugly *64 functions with _LARGEFILE64_SOURCERich Felker-0/+10
musl does not support legacy 32-bit-off_t whatsoever. off_t is always 64 bit, and correct programs that use off_t and the standard functions will just work out of the box. (on glibc, they would require -D_FILE_OFFSET_BITS=64 to work.) however, some programs instead define _LARGEFILE64_SOURCE and use alternate versions of all the standard types and functions with "64" appended to their names. we do not want code to actually get linked against these functions (it's ugly and inconsistent), so macros are used instead of prototypes with weak aliases in the library itself. eventually the weak aliases may be added at the library level for the sake of using code that was originally built against glibc, but the macros will still be the desired solution in the headers.
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