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Joseph Myers d709042a6e Fix lgamma setting signgam for ISO C (bug 15421).
The lgamma (and likewise lgammaf, lgammal) function wrongly sets the
signgam variable even when building for strict ISO C conformance
(-std=c99 / -std=c11), although the user may define such a variable
and it's only in the implementation namespace for POSIX with XSI
extensions enabled.

Following discussions starting at
<https://sourceware.org/ml/libc-alpha/2013-04/msg00767.html> and
<https://sourceware.org/ml/libc-alpha/2015-10/msg00844.html>, it seems
that the safest approach for fixing this particular issue is for
signgam to become a weak alias for a newly exported symbol __signgam,
with the library functions only setting __signgam, at which point
static linker magic will preserve the alias for newly linked binaries
that refer to the library's signgam rather than defining their own,
while breaking the alias for programs that define their own signgam,
with new symbol versions for lgamma functions and with compat symbols
for existing binaries that set both signgam and __signgam.

This patch implements that approach for the fix.  signgam is made into
a weak alias.  The four symbols __signgam, lgamma, lgammaf, lgammal
get new symbol versions at version GLIBC_2.23, with the existing
versions of lgamma, lgammaf and lgammal becoming compat symbols.

When the compat versions are built, gamma, gammaf and gammal are
aliases for the compat versions (i.e. always set signgam); this is OK
as they are not ISO C functions, and avoids adding new symbol versions
for them unnecessarily.  When the compat versions are not built
(i.e. for static linking and for future glibc ports), gamma, gammaf
and gammal are aliases for the new versions that set __signgam.  The
ldbl-opt versions are updated accordingly.

The lgamma wrappers are adjusted so that the same source files,
included from different files with different definitions of
USE_AS_COMPAT, can build either the new versions or the compat
versions.  Similar changes are made to the ia64 versions (untested).

Tests are added that the lgamma functions do not interfere with a user
variable called signgam for ISO C, with various choices for the size
of that variable, whether it is initialized, and for static and
dynamic linking.  The conformtest whitelist entry is removed as well.

Tested for x86_64, x86, mips64 and powerpc, including looking at
objdump --dynamic-syms output to make sure the expected sets of
symbols were aliases.  Also spot-tested that a binary built with old
glibc works properly (i.e. gets signgam set) when run with new glibc.

	[BZ #15421]
	* sysdeps/ieee754/s_signgam.c (signgam): Rename to __signgam,
	initialize with 0 and define as weak alias of __signgam.
	* include/math.h [!_ISOMAC] (__signgam): Declare.
	* math/Makefile (libm-calls): Add w_lgamma_compat.
	(tests): Add test-signgam-uchar, test-signgam-uchar-init,
	test-signgam-uint, test-signgam-uint-init, test-signgam-ullong and
	test-signgam-ullong-init.
	(tests-static): Add test-signgam-uchar-static,
	test-signgam-uchar-init-static, test-signgam-uint-static,
	test-signgam-uint-init-static, test-signgam-ullong-static and
	test-signgam-ullong-init-static.
	(CFLAGS-test-signgam-uchar.c): New variable.
	(CFLAGS-test-signgam-uchar-init.c): Likewise.
	(CFLAGS-test-signgam-uchar-static.c): Likewise.
	(CFLAGS-test-signgam-uchar-init-static.c): Likewise.
	(CFLAGS-test-signgam-uint.c): Likewise.
	(CFLAGS-test-signgam-uint-init.c): Likewise.
	(CFLAGS-test-signgam-uint-static.c): Likewise.
	(CFLAGS-test-signgam-uint-init-static.c): Likewise.
	(CFLAGS-test-signgam-ullong.c): Likewise.
	(CFLAGS-test-signgam-ullong-init.c): Likewise.
	(CFLAGS-test-signgam-ullong-static.c): Likewise.
	(CFLAGS-test-signgam-ullong-init-static.c): Likewise.
	* math/Versions (libm): Add GLIBC_2.23.
	* math/lgamma-compat.h: New file.
	* math/test-signgam-main.c: Likewise.
	* math/test-signgam-uchar-init-static.c: Likewise.
	* math/test-signgam-uchar-init.c: Likewise.
	* math/test-signgam-uchar-static.c: Likewise.
	* math/test-signgam-uchar.c: Likewise.
	* math/test-signgam-uint-init-static.c: Likewise.
	* math/test-signgam-uint-init.c: Likewise.
	* math/test-signgam-uint-static.c: Likewise.
	* math/test-signgam-uint.c: Likewise.
	* math/test-signgam-ullong-init-static.c: Likewise.
	* math/test-signgam-ullong-init.c: Likewise.
	* math/test-signgam-ullong-static.c: Likewise.
	* math/test-signgam-ullong.c: Likewise.
	* math/w_lgamma.c: Rename to w_lgamma_main.c and replace by
	wrapper of w_lgamma_main.c.
	* math/w_lgamma_compat.c: New file.
	* math/w_lgamma_compatf.c: Likewise.
	* math/w_lgamma_compatl.c: Likewise.
	* math/w_lgamma_main.c: New file.  Based on w_lgamma.c.  Include
	<lgamma-compat.h>.  Condition contents on [BUILD_LGAMMA].  Support
	defining compatibility symbols.
	(__lgamma): Change to LGFUNC (__lgamma).  Use CALL_LGAMMA.
	* math/w_lgammaf.c: Rename to w_lgammaf_main.c and replace by
	wrapper of w_lgammaf_main.c.
	* math/w_lgammaf_main.c: New file.  Based on w_lgammaf.c.  Include
	<lgamma-compat.h>.  Condition contents on [BUILD_LGAMMA].  Support
	defining compatibility symbols.
	(__lgammaf): Change to LGFUNC (__lgammaf).  Use CALL_LGAMMA.
	* math/w_lgammal.c: Rename to w_lgammal_main.c and replace by
	wrapper of w_lgammal_main.c.
	* math/w_lgammal_main.c: New file.  Based on w_lgammal.c.  Include
	<lgamma-compat.h>.  Condition contents on [BUILD_LGAMMA].  Support
	defining compatibility symbols.
	(__lgammal): Change to LGFUNC (__lgammal).  Use CALL_LGAMMA.
	* sysdeps/ia64/fpu/lgamma-compat.h: New file.
	* sysdeps/ia64/fpu/w_lgamma.c: Move to ....
	* sysdeps/ia64/fpu/w_lgamma_main.c: ...here.  Include
	<lgamma-compat.h>.
	(__ieee754_lgamma): Change to LGFUNC (lgamma).  Use CALL_LGAMMA.
	(__ieee754_gamma): Define as alias.
	* sysdeps/ia64/fpu/w_lgammaf.c: Move to ....
	* sysdeps/ia64/fpu/w_lgammaf_main.c: ...here.  Include
	<lgamma-compat.h>.
	(__ieee754_lgammaf): Change to LGFUNC (lgammaf).  Use CALL_LGAMMA.
	(__ieee754_gammaf): Define as alias.
	* sysdeps/ia64/fpu/w_lgammal.c: Move to ....
	* sysdeps/ia64/fpu/w_lgammal_main.c: ...here.  Include
	<lgamma-compat.h>.
	(__ieee754_lgammal): Change to LGFUNC (lgammal).  Use CALL_LGAMMA.
	(__ieee754_gammal): Define as alias.
	* sysdeps/ieee754/ldbl-opt/w_lgamma.c: Move to ....
	* sysdeps/ieee754/ldbl-opt/w_lgamma_compat.c: ...here.  Include
	<math/w_lgamma_compat.c>.
	[LONG_DOUBLE_COMPAT(libm, GLIBC_2_0)] (__lgammal_dbl_compat):
	Define as alias of __lgamma_compat and use in defining lgammal.
	* sysdeps/ieee754/ldbl-opt/w_lgammal.c: Move to ....
	* sysdeps/ieee754/ldbl-opt/w_lgamma_compatl.c: ...here.  Include
	<math/lgamma-compat.h> and <math/w_lgamma_compatl.c>.
	(USE_AS_COMPAT): New macro.
	(LGAMMA_OLD_VER): Undefine and redefine.
	(lgammal): Do not define here.
	(gammal): Only define here if [GAMMA_ALIAS].
	* conform/linknamespace.pl (@whitelist): Remove signgam.
	* sysdeps/nacl/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
2015-11-20 22:49:59 +00:00
argp Update copyright dates with scripts/update-copyrights. 2015-01-02 16:29:47 +00:00
assert Don't macro-expand failed assertion expression [BZ #18604] 2015-11-03 23:26:15 +01:00
benchtests benchtests: Mark output variables as used 2015-11-17 16:01:15 +05:30
bits Move bits/atomic.h to atomic-machine.h (bug 14912). 2015-09-11 20:00:19 +00:00
catgets Fix trailing space. 2015-08-08 15:54:40 -07:00
conf (NEED_INETADDR, NEED_INETATON): Define to 1, not empty. 1995-09-08 20:24:57 +00:00
conform Fix lgamma setting signgam for ISO C (bug 15421). 2015-11-20 22:49:59 +00:00
crypt Convert 113 more function definitions to prototype style (files with assertions). 2015-10-20 11:54:09 +00:00
csu Fix gcrt0.o compilation 2015-08-07 01:38:39 +02:00
ctype Convert 703 function definitions to prototype style. 2015-10-16 20:21:49 +00:00
debug tst-backtrace4: fix a warning message 2015-10-21 11:24:27 -04:00
dirent Convert 703 function definitions to prototype style. 2015-10-16 20:21:49 +00:00
dlfcn Move bits/libc-lock.h and bits/libc-lockP.h out of bits/ (bug 14912). 2015-09-08 21:11:03 +00:00
elf Run tst-prelink test for GLOB_DAT reloc 2015-11-14 12:00:38 -08:00
gmon Convert 703 function definitions to prototype style. 2015-10-16 20:21:49 +00:00
gnulib Update copyright dates with scripts/update-copyrights. 2015-01-02 16:29:47 +00:00
grp Convert 703 function definitions to prototype style. 2015-10-16 20:21:49 +00:00
gshadow Harden putpwent, putgrent, putspent, putspent against injection [BZ #18724] 2015-10-02 11:34:13 +02:00
hesiod Update copyright dates with scripts/update-copyrights. 2015-01-02 16:29:47 +00:00
hurd Convert 113 more function definitions to prototype style (files with assertions). 2015-10-20 11:54:09 +00:00
iconv Fix BZ #19012 -- iconv_open leaks memory on error path. 2015-10-05 20:03:48 -07:00
iconvdata Add dependencies on needed locales in each subdir tests (bug 18969) 2015-10-12 15:18:08 +02:00
include Fix lgamma setting signgam for ISO C (bug 15421). 2015-11-20 22:49:59 +00:00
inet Convert 113 more function definitions to prototype style (files with assertions). 2015-10-20 11:54:09 +00:00
intl Add dependencies on needed locales in each subdir tests (bug 18969) 2015-10-12 15:18:08 +02:00
io Add LFS support for fts functions (bug 11460) 2015-11-06 11:24:16 +01:00
libidn Move bits/libc-lock.h and bits/libc-lockP.h out of bits/ (bug 14912). 2015-09-08 21:11:03 +00:00
libio Convert miscellaneous function definitions to prototype style. 2015-10-20 21:27:22 +00:00
locale Gracefully handle incompatible locale data 2015-10-27 13:33:26 +01:00
localedata lt_LT: change currency symbol to the euro [BZ #18953] 2015-10-17 00:28:13 -04:00
login Convert miscellaneous function definitions to prototype style. 2015-10-20 21:27:22 +00:00
mach Convert miscellaneous function definitions to prototype style. 2015-10-20 21:27:22 +00:00
malloc Don't macro-expand failed assertion expression [BZ #18604] 2015-11-03 23:26:15 +01:00
manual Require GCC 4.7 or later to build glibc. 2015-10-27 16:34:12 +00:00
math Fix lgamma setting signgam for ISO C (bug 15421). 2015-11-20 22:49:59 +00:00
mathvec This is update for configure, build and install of vector math library. 2015-05-14 18:07:06 +03:00
misc Fix some stub prototypes missing ... after K&R conversion 2015-11-05 15:00:12 -08:00
nis Assume that SOCK_CLOEXEC is available and works 2015-10-17 12:02:37 +02:00
nptl Remove a spurious attribution 2015-11-04 11:32:36 +01:00
nptl_db Convert 113 more function definitions to prototype style (files with assertions). 2015-10-20 11:54:09 +00:00
nscd use -fstack-protector-strong when available 2015-10-19 15:36:48 -04:00
nss Convert 113 more function definitions to prototype style (files with assertions). 2015-10-20 11:54:09 +00:00
po Update de.po from Translation Project (bug 4404). 2015-09-16 16:51:28 +00:00
posix Convert a few more function definitions to prototype style. 2015-10-21 11:57:23 +00:00
pwd Convert 703 function definitions to prototype style. 2015-10-16 20:21:49 +00:00
resolv Remove GCC version conditionals on -Wmaybe-uninitialized pragmas. 2015-10-27 23:42:20 +00:00
resource Convert 703 function definitions to prototype style. 2015-10-16 20:21:49 +00:00
rt Convert 703 function definitions to prototype style. 2015-10-16 20:21:49 +00:00
scripts pylintrc: disable reports 2015-11-11 13:41:57 -05:00
setjmp Modify several tests to use test-skeleton.c 2015-07-15 15:10:23 +05:30
shadow Harden putpwent, putgrent, putspent, putspent against injection [BZ #18724] 2015-10-02 11:34:13 +02:00
signal Convert 703 function definitions to prototype style. 2015-10-16 20:21:49 +00:00
socket Convert 24 more function definitions to prototype style (array parameters). 2015-10-20 11:51:03 +00:00
soft-fp Remove GCC version conditionals on -Wmaybe-uninitialized pragmas. 2015-10-27 23:42:20 +00:00
stdio-common Convert 69 more function definitions to prototype style (line wrap cases). 2015-10-19 21:23:47 +00:00
stdlib Remove GCC version conditionals on -Wmaybe-uninitialized pragmas. 2015-10-27 23:42:20 +00:00
streams Convert 69 more function definitions to prototype style (line wrap cases). 2015-10-19 21:23:47 +00:00
string Convert miscellaneous function definitions to prototype style. 2015-10-20 21:27:22 +00:00
sunrpc Convert a few more function definitions to prototype style. 2015-10-21 11:57:23 +00:00
sysdeps Fix lgamma setting signgam for ISO C (bug 15421). 2015-11-20 22:49:59 +00:00
sysvipc Convert 69 more function definitions to prototype style (line wrap cases). 2015-10-19 21:23:47 +00:00
termios Convert 703 function definitions to prototype style. 2015-10-16 20:21:49 +00:00
time Convert miscellaneous function definitions to prototype style. 2015-10-20 21:27:22 +00:00
timezone Update timezone/Makefile to use -Wno-unused-variable 2015-10-07 15:04:49 -07:00
wcsmbs Convert miscellaneous function definitions to prototype style. 2015-10-20 21:27:22 +00:00
wctype Convert 703 function definitions to prototype style. 2015-10-16 20:21:49 +00:00
.gitattributes exempt timezone files from the no-bad-whitespace policy 2009-06-15 18:15:54 +02:00
.gitignore Add *.pyc to .gitignore 2015-05-18 15:26:26 +05:30
abi-tags Add arm-nacl port. 2015-04-17 09:02:19 -07:00
aclocal.m4 Make aclocal.m4 comment mention updating install.texi for autoconf version. 2014-10-31 22:44:17 +00:00
BUGS [BZ #5222] 2007-10-28 08:24:07 +00:00
ChangeLog Fix lgamma setting signgam for ISO C (bug 15421). 2015-11-20 22:49:59 +00:00
ChangeLog.1 * Makefile (distribute): Add ChangeLog.[0-9]. 1995-04-14 03:52:54 +00:00
ChangeLog.2 * Makefile (distribute): Add ChangeLog.[0-9]. 1995-04-14 03:52:54 +00:00
ChangeLog.3 * Makefile (distribute): Add ChangeLog.[0-9]. 1995-04-14 03:52:54 +00:00
ChangeLog.4 * Makefile (distribute): Add ChangeLog.[0-9]. 1995-04-14 03:52:54 +00:00
ChangeLog.5 * sysdeps/posix/getaddrinfo.c: Implement configuration file 2006-05-04 06:38:07 +00:00
ChangeLog.6 Update. 1997-07-22 00:10:33 +00:00
ChangeLog.7 Update. 1997-11-18 02:50:07 +00:00
ChangeLog.8 Update. Old logs are in ChangeLog.7. 1998-08-11 18:44:11 +00:00
ChangeLog.9 Update. 2000-04-28 06:14:43 +00:00
ChangeLog.10 Update. 2000-02-29 01:13:44 +00:00
ChangeLog.11 2.5-18.1 2007-07-12 18:26:36 +00:00
ChangeLog.12 2.5-18.1 2007-07-12 18:26:36 +00:00
ChangeLog.13 Update. 2002-10-03 16:37:04 +00:00
ChangeLog.14 Update. 2004-04-20 04:28:00 +00:00
ChangeLog.15 Split out ChangeLog.15 at 2.3 branch point 2005-02-16 07:34:17 +00:00
ChangeLog.16 Fix typo in name 2012-06-21 16:45:27 +02:00
ChangeLog.17 Revert "Sun agreed to a change of the license for the RPC code to a BSD-like license." 2010-06-27 19:34:03 -07:00
ChangeLog.old-ports Move ports/ChangeLog* files to ChangeLog.old-ports*, remove ports/ directory. 2014-04-30 10:40:29 -07:00
ChangeLog.old-ports-aarch64 Move ports/ChangeLog* files to ChangeLog.old-ports*, remove ports/ directory. 2014-04-30 10:40:29 -07:00
ChangeLog.old-ports-aix Move ports/ChangeLog* files to ChangeLog.old-ports*, remove ports/ directory. 2014-04-30 10:40:29 -07:00
ChangeLog.old-ports-alpha Move ports/ChangeLog* files to ChangeLog.old-ports*, remove ports/ directory. 2014-04-30 10:40:29 -07:00
ChangeLog.old-ports-am33 Move ports/ChangeLog* files to ChangeLog.old-ports*, remove ports/ directory. 2014-04-30 10:40:29 -07:00
ChangeLog.old-ports-arm Move ports/ChangeLog* files to ChangeLog.old-ports*, remove ports/ directory. 2014-04-30 10:40:29 -07:00
ChangeLog.old-ports-cris Move ports/ChangeLog* files to ChangeLog.old-ports*, remove ports/ directory. 2014-04-30 10:40:29 -07:00
ChangeLog.old-ports-hppa Move ports/ChangeLog* files to ChangeLog.old-ports*, remove ports/ directory. 2014-04-30 10:40:29 -07:00
ChangeLog.old-ports-ia64 Move ports/ChangeLog* files to ChangeLog.old-ports*, remove ports/ directory. 2014-04-30 10:40:29 -07:00
ChangeLog.old-ports-linux-generic Move ports/ChangeLog* files to ChangeLog.old-ports*, remove ports/ directory. 2014-04-30 10:40:29 -07:00
ChangeLog.old-ports-m68k Move ports/ChangeLog* files to ChangeLog.old-ports*, remove ports/ directory. 2014-04-30 10:40:29 -07:00
ChangeLog.old-ports-microblaze Move ports/ChangeLog* files to ChangeLog.old-ports*, remove ports/ directory. 2014-04-30 10:40:29 -07:00
ChangeLog.old-ports-mips Move ports/ChangeLog* files to ChangeLog.old-ports*, remove ports/ directory. 2014-04-30 10:40:29 -07:00
ChangeLog.old-ports-powerpc Move ports/ChangeLog* files to ChangeLog.old-ports*, remove ports/ directory. 2014-04-30 10:40:29 -07:00
ChangeLog.old-ports-tile Move ports/ChangeLog* files to ChangeLog.old-ports*, remove ports/ directory. 2014-04-30 10:40:29 -07:00
config.h.in Remove -mavx2 configure tests. 2015-10-28 13:29:03 +00:00
config.make.in Run tst-prelink test for GLOB_DAT reloc 2015-11-14 12:00:38 -08:00
configure Run tst-prelink test for GLOB_DAT reloc 2015-11-14 12:00:38 -08:00
configure.ac Run tst-prelink test for GLOB_DAT reloc 2015-11-14 12:00:38 -08:00
CONFORMANCE Move __STDC_* predefined macros from features.h to stdc-predef.h. 2012-02-22 12:53:04 +00:00
COPYING Update to latest versions of GPL-2.0 and LGPL-2.1 2013-09-09 12:52:48 +10:00
COPYING.LIB Update to latest versions of GPL-2.0 and LGPL-2.1 2013-09-09 12:52:48 +10:00
cppflags-iterator.mk 2004-03-11 Jeroen Dekkers <jeroen@dekkers.cx> 2004-03-14 19:13:17 +00:00
extra-lib.mk Remove NOT_IN_libc 2014-11-24 15:03:45 +05:30
extra-modules.mk Remove NOT_IN_libc 2014-11-24 15:03:45 +05:30
gen-locales.mk Split locale generation snippet into a separate file 2015-05-13 13:05:28 +05:30
INSTALL Require GCC 4.7 or later to build glibc. 2015-10-27 16:34:12 +00:00
libc-abis A few more archs have IFUNC support. 2010-03-17 02:43:12 -07:00
LICENSES Expand LICENSES file. 2012-12-05 21:56:15 +00:00
Makeconfig Use -std=gnu11 instead of -std=gnu99. 2015-10-27 21:47:22 +00:00
Makefile Use -std=gnu11 instead of -std=gnu99. 2015-10-27 21:47:22 +00:00
Makefile.in Remove redundant C locale settings. 2014-06-07 19:58:36 +00:00
Makerules Remove -static-libgcc configure test. 2015-10-15 19:32:58 +00:00
NAMESPACE Add and update many more entries. 2000-03-20 00:42:58 +00:00
NEWS Fix lgamma setting signgam for ISO C (bug 15421). 2015-11-20 22:49:59 +00:00
o-iterator.mk Fri Mar 17 12:58:37 1995 Roland McGrath <roland@churchy.gnu.ai.mit.edu> 1995-03-17 18:42:51 +00:00
PROJECTS Update. 2004-10-12 06:19:23 +00:00
README Another pointless update in README. 2015-02-11 14:39:30 -08:00
Rules Let tests result in UNSUPPORTED; use that for unbuildable C++ cases 2015-03-10 15:13:14 -07:00
shlib-versions This is update for configure, build and install of vector math library. 2015-05-14 18:07:06 +03:00
test-skeleton.c test-skeleton: add usage information 2015-08-05 04:40:00 -04:00
version.h Open development for 2.23. 2015-08-05 03:01:50 -04:00
WUR-REPORT * posix/unistd.h (setuid, setreuid, seteuid, setresuid): 2012-08-01 18:12:58 +02:00

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 2.6.32 or later.

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.