487890009e
This patch implements support for the __STDC_WANT_LIB_EXT2__ feature test macro from ISO/IEC TR 24731-2:2010, thereby implementing one possible approach for supporting ISO C feature test macros. Recall that, as described in <https://sourceware.org/ml/libc-alpha/2016-05/msg00486.html>, these macros work based on the definition when affected headers are included, so cannot be handled once when the first system header is included because that might not be one of the headers the particular macro in question affects. <https://sourceware.org/ml/libc-alpha/2016-05/msg00680.html> expresses views on possible approaches for implementation and <https://sourceware.org/ml/libc-alpha/2016-06/msg00039.html> follows up on that. This patch arranges things so that the relevant condition is __GLIBC_USE (LIB_EXT2), following one of the suggestions given. Headers using these macros include <bits/libc-header-start.h>, which in turn includes <features.h>. Headers must define __GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION before including <bits/libc-header-start.h>, to discourage inclusion outside glibc as requested. __USE_GNU conditions on affected functions are changed to __GLIBC_USE (LIB_EXT2), while it's added as an additional alternative on the conditions for functions already enabled for some POSIX versions. It would be possible to convert existing __USE_* conditionals to __GLIBC_USE (with the relevant __GLIBC_USE_* being defined in <features.h> where __USE_* are presently defined), and so make them typo-proof (given -Wundef -Werror in glibc builds) because __GLIBC_USE is used with #if not #ifdef / #if defined. No attempt is made to enforce the rule about diagnosing different definitions of __STDC_WANT_LIB_EXT2__ when affected headers are included; such a diagnostic is incompatible with multiple-include guards on the affected headers, unless compiler extensions are added to support it. As previously noted, glibc does not implement all features from TR 24731-2:2010: the functions aswprintf vaswprintf getwdelim getwline are not in glibc, although they would be appropriate to add if someone wished to do so. But I think it makes sense to support the feature test macro if *any* of the controlled features are present in glibc. Tested for x86_64 and x86 (testsuite, and that installed stripped shared libraries are unchanged by the patch). * bits/libc-header-start.h: New file. * Makefile (headers): Add bits/libc-header-start.h. * include/features.h (__STDC_WANT_LIB_EXT2__): Document. (__GLIBC_USE): New macro. * libio/stdio.h: Define __GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION and include <bits/libc-header-start.h> instead of including <features.h>. (fmemopen): Declare also if [__GLIBC_USE (LIB_EXT2)]. (open_memstream): Likewise. (vasprintf): Declare if [__GLIBC_USE (LIB_EXT2)], not [__USE_GNU]. (__asprintf): Likewise. (asprintf): Likewise. (__getdelim): Declare also if [__GLIBC_USE (LIB_EXT2)]. (getdelim): Likewise. (getline): Likewise. * string/string.h: Define __GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION and include <bits/libc-header-start.h> instead of including <features.h>. (strdup): Declare also if [__GLIBC_USE (LIB_EXT2)] (strndup): Likewise. * wcsmbs/wchar.h: Define __GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION and include <bits/libc-header-start.h> instead of including <features.h>. (open_wmemstream): Declare also if [__GLIBC_USE (LIB_EXT2)]. * manual/creature.texi (__STDC_WANT_LIB_EXT2__): Document macro. |
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argp | ||
assert | ||
benchtests | ||
bits | ||
catgets | ||
conform | ||
crypt | ||
csu | ||
ctype | ||
debug | ||
dirent | ||
dlfcn | ||
elf | ||
gmon | ||
gnulib | ||
grp | ||
gshadow | ||
hesiod | ||
hurd | ||
iconv | ||
iconvdata | ||
include | ||
inet | ||
intl | ||
io | ||
libidn | ||
libio | ||
locale | ||
localedata | ||
login | ||
mach | ||
malloc | ||
manual | ||
math | ||
mathvec | ||
misc | ||
nis | ||
nptl | ||
nptl_db | ||
nscd | ||
nss | ||
po | ||
posix | ||
pwd | ||
resolv | ||
resource | ||
rt | ||
scripts | ||
setjmp | ||
shadow | ||
signal | ||
socket | ||
soft-fp | ||
stdio-common | ||
stdlib | ||
streams | ||
string | ||
sunrpc | ||
sysdeps | ||
sysvipc | ||
termios | ||
time | ||
timezone | ||
wcsmbs | ||
wctype | ||
.gitattributes | ||
.gitignore | ||
abi-tags | ||
aclocal.m4 | ||
BUGS | ||
ChangeLog | ||
ChangeLog.1 | ||
ChangeLog.2 | ||
ChangeLog.3 | ||
ChangeLog.4 | ||
ChangeLog.5 | ||
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ChangeLog.16 | ||
ChangeLog.17 | ||
ChangeLog.old-ports | ||
ChangeLog.old-ports-aarch64 | ||
ChangeLog.old-ports-aix | ||
ChangeLog.old-ports-alpha | ||
ChangeLog.old-ports-am33 | ||
ChangeLog.old-ports-arm | ||
ChangeLog.old-ports-cris | ||
ChangeLog.old-ports-hppa | ||
ChangeLog.old-ports-ia64 | ||
ChangeLog.old-ports-linux-generic | ||
ChangeLog.old-ports-m68k | ||
ChangeLog.old-ports-microblaze | ||
ChangeLog.old-ports-mips | ||
ChangeLog.old-ports-powerpc | ||
ChangeLog.old-ports-tile | ||
config.h.in | ||
config.make.in | ||
configure | ||
configure.ac | ||
CONFORMANCE | ||
COPYING | ||
COPYING.LIB | ||
cppflags-iterator.mk | ||
extra-lib.mk | ||
extra-modules.mk | ||
gen-locales.mk | ||
INSTALL | ||
libc-abis | ||
LICENSES | ||
Makeconfig | ||
Makefile | ||
Makefile.in | ||
Makerules | ||
NAMESPACE | ||
NEWS | ||
o-iterator.mk | ||
PROJECTS | ||
README | ||
Rules | ||
shlib-versions | ||
test-skeleton.c | ||
version.h | ||
WUR-REPORT |
This directory contains the sources of the GNU C Library. See the file "version.h" for what release version you have. The GNU C Library is the standard system C library for all GNU systems, and is an important part of what makes up a GNU system. It provides the system API for all programs written in C and C-compatible languages such as C++ and Objective C; the runtime facilities of other programming languages use the C library to access the underlying operating system. In GNU/Linux systems, the C library works with the Linux kernel to implement the operating system behavior seen by user applications. In GNU/Hurd systems, it works with a microkernel and Hurd servers. The GNU C Library implements much of the POSIX.1 functionality in the GNU/Hurd system, using configurations i[4567]86-*-gnu. The current GNU/Hurd support requires out-of-tree patches that will eventually be incorporated into an official GNU C Library release. When working with Linux kernels, this version of the GNU C Library requires Linux kernel version 3.2 or later on all architectures except i[4567]86 and x86_64, where Linux kernel version 2.6.32 or later suffices. Also note that the shared version of the libgcc_s library must be installed for the pthread library to work correctly. The GNU C Library supports these configurations for using Linux kernels: aarch64*-*-linux-gnu alpha*-*-linux-gnu arm-*-linux-gnueabi hppa-*-linux-gnu Not currently functional without patches. i[4567]86-*-linux-gnu x86_64-*-linux-gnu Can build either x86_64 or x32 ia64-*-linux-gnu m68k-*-linux-gnu microblaze*-*-linux-gnu mips-*-linux-gnu mips64-*-linux-gnu powerpc-*-linux-gnu Hardware or software floating point, BE only. powerpc64*-*-linux-gnu Big-endian and little-endian. s390-*-linux-gnu s390x-*-linux-gnu sh[34]-*-linux-gnu sparc*-*-linux-gnu sparc64*-*-linux-gnu tilegx-*-linux-gnu tilepro-*-linux-gnu If you are interested in doing a port, please contact the glibc maintainers; see http://www.gnu.org/software/libc/ for more information. See the file INSTALL to find out how to configure, build, and install the GNU C Library. You might also consider reading the WWW pages for the C library at http://www.gnu.org/software/libc/. The GNU C Library is (almost) completely documented by the Texinfo manual found in the `manual/' subdirectory. The manual is still being updated and contains some known errors and omissions; we regret that we do not have the resources to work on the manual as much as we would like. For corrections to the manual, please file a bug in the `manual' component, following the bug-reporting instructions below. Please be sure to check the manual in the current development sources to see if your problem has already been corrected. Please see http://www.gnu.org/software/libc/bugs.html for bug reporting information. We are now using the Bugzilla system to track all bug reports. This web page gives detailed information on how to report bugs properly. The GNU C Library is free software. See the file COPYING.LIB for copying conditions, and LICENSES for notices about a few contributions that require these additional notices to be distributed. License copyright years may be listed using range notation, e.g., 1996-2015, indicating that every year in the range, inclusive, is a copyrightable year that would otherwise be listed individually.