Go to file
Joseph Myers 49348beafe Fix build with GCC 10 when long double = double.
On platforms where long double has the same ABI as double, glibc
defines long double functions as aliases for the corresponding double
functions.  The declarations of those functions in <math.h> are
disabled to avoid problems with aliases having incompatible types, but
GCC 10 now gives errors for incompatible types when the long double
function is known to GCC as a built-in function, not just when there
is an incompatible header declaration.

This patch fixes those errors by using appropriate
-fno-builtin-<function> options to compile the double functions.  The
list of CFLAGS-* settings is an appropriately adapted version of that
in sysdeps/ieee754/ldbl-opt/Makefile used there for building nldbl-*.c
files; in particular, the options are used even if GCC does not
currently have a built-in function of a given function, so that adding
such a built-in function in future will not break the glibc build.
Thus, various of the CFLAGS-* settings are only for future-proofing
and may not currently be needed (and it's possible some could be
irrelevant for other reasons).

Tested with build-many-glibcs.py for arm-linux-gnueabi (compilers and
glibcs builds), where it fixes the build that previously failed.
2020-03-17 22:57:42 +00:00
ChangeLog.old Generate ChangeLog.old/ChangeLog.20 for 2.31 2020-02-01 17:22:50 +05:30
argp Prepare redirections for IEEE long double on powerpc64le 2020-02-17 15:28:29 -06:00
assert Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
benchtests Convert Python scripts to Python 3 2020-03-03 15:52:09 -08:00
bits y2038: Define __suseconds64_t type to be used with struct __timeval64 2020-02-07 17:55:07 +01:00
catgets Update copyright dates not handled by scripts/update-copyrights. 2020-01-01 00:21:22 +00:00
conform Convert Python scripts to Python 3 2020-03-03 15:52:09 -08:00
crypt Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
csu csu: Use ELF constructor instead of _init in libc.so 2020-02-25 14:58:52 +01:00
ctype Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
debug mips: Fix bracktrace result for signal frames 2020-02-18 10:39:03 -03:00
dirent Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
dlfcn Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
elf parse_tunables: Fix typo in comment 2020-03-13 10:27:23 +00:00
gmon Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
gnulib Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
grp Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
gshadow Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
hesiod nss_hesiod: Use NSS_DECLARE_MODULE_FUNCTIONS 2020-02-13 09:14:44 +01:00
htl htl: Link internal htl tests against libpthread 2020-02-17 00:36:53 +01:00
hurd hurd: Add THREAD_GET/SETMEM/_NC 2020-02-15 14:18:17 +01:00
iconv Update copyright dates not handled by scripts/update-copyrights. 2020-01-01 00:21:22 +00:00
iconvdata Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
include y2038: linux: Provide __futimesat64 implementation 2020-03-09 10:26:46 +01:00
inet Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
intl Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
io Linux: Work around kernel bugs in chmod on /proc/self/fd paths [BZ #14578] 2020-02-18 17:52:27 +01:00
libio <fd_to_filename.h>: Add type safety and port to Hurd 2020-02-18 13:42:29 +01:00
locale Fix locale/tst-locale-locpath cross-testing when sshd sets LANG. 2020-01-24 17:23:07 +00:00
localedata Fix typo in the name for Wednesday in Kurdish [BZ #9809] 2020-02-11 10:18:45 +01:00
login Update copyright dates not handled by scripts/update-copyrights. 2020-01-01 00:21:22 +00:00
mach Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
malloc malloc/tst-mallocfork2: Kill lingering process for unexpected failures 2020-02-27 13:43:57 -03:00
manual manual: Fix inconsistent declaration of wcsrchr [BZ #24655] 2020-03-13 17:45:04 -04:00
math Fix build with GCC 10 when long double = double. 2020-03-17 22:57:42 +00:00
mathvec Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
misc <fd_to_filename.h>: Add type safety and port to Hurd 2020-02-18 13:42:29 +01:00
nis nss_nis: Use NSS_DECLARE_MODULE_FUNCTIONS 2020-02-25 16:15:09 +01:00
nptl Linux: set_robust_list syscall number is always available 2020-03-03 12:49:44 +01:00
nptl_db Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
nscd nscd/cachedumper.c : fix whitespace 2020-03-17 14:03:43 -04:00
nss nss_files: Use NSS_DECLARE_MODULE_FUNCTIONS 2020-02-13 09:14:54 +01:00
po Update translations 2020-03-04 07:27:32 +05:30
posix posix: Refactor tst-waitid (BZ #14666) 2020-02-27 16:16:16 -03:00
pwd Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
resolv Move implementation of <file_change_detection.h> into a C file 2020-02-18 13:44:48 +01:00
resource Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
rt Block all signals on timer_create thread (BZ#10815) 2020-02-19 13:46:31 -03:00
scripts build-many-glibcs.py: Add list-compilers, list-glibcs commands 2020-03-03 07:39:16 +01:00
setjmp Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
shadow Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
signal Build raise with -fasynchronous-unwind-tables. 2020-01-24 17:23:47 +00:00
socket Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
soft-fp Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
stdio-common Prepare redirections for IEEE long double on powerpc64le 2020-02-17 15:28:29 -06:00
stdlib gcc PR 89877: miscompilation due to missing cc clobber in longlong.h macros 2020-03-10 18:57:28 -07:00
string Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
sunrpc sunrpc: Properly clean up if tst-udp-timeout fails 2020-02-12 16:25:34 -03:00
support test-container: print errno when execvp fails 2020-03-11 16:00:58 -04:00
sysdeps [AArch64] Improve integer memcpy 2020-03-11 17:15:25 +00:00
sysvipc Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
termios Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
time alpha: Fix static gettimeofday symbol 2020-02-13 08:27:27 -03:00
timezone Update timezone/README 2020-01-09 23:00:25 -08:00
wcsmbs Prepare redirections for IEEE long double on powerpc64le 2020-02-17 15:28:29 -06:00
wctype Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
.gitattributes Assume __NR_openat is always defined 2016-03-23 23:35:08 +01:00
.gitignore
COPYING
COPYING.LIB
INSTALL Update newest tested versions of dependencies in install.texi 2020-02-01 17:16:54 +05:30
LICENSES Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
MAINTAINERS Add MAINTAINERS 2017-05-11 13:38:30 -04:00
Makeconfig Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
Makefile Drop dependency of dist target on ChangeLog 2020-01-09 13:28:08 +05:30
Makefile.help Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
Makefile.in New make target to only build benchmark binaries 2016-04-20 10:23:28 +05:30
Makerules Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
NEWS Add NEWS entry for CVE-2020-10029 (bug 25487) 2020-03-11 12:20:26 +01:00
README Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
Rules Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
abi-tags Remove the bulk of the NaCl port. 2017-05-20 08:09:10 -04:00
aclocal.m4 LIBC_SLIBDIR_RTLDDIR: substitute arguments in single quotes 2018-01-25 17:20:28 +01:00
config.h.in sparc: Assume GOTDATA support in the toolchain 2019-10-09 19:15:33 +02:00
config.make.in Make --bindir effective 2019-05-14 11:04:33 -03:00
configure Remove reference of --without-fp on configure 2020-03-06 09:53:24 -03:00
configure.ac Remove reference of --without-fp on configure 2020-03-06 09:53:24 -03:00
extra-lib.mk Rename cppflags-iterator.mk to libof-iterator.mk, remove extra-modules.mk. 2017-05-09 07:06:29 -04:00
gen-locales.mk Improve gen-locales.mk and gen-locale.sh to make test files with @ options work 2018-02-27 17:01:57 +01:00
libc-abis libc-abis: Define ABSOLUTE ABI [BZ #19818][BZ #23307] 2018-07-05 18:06:43 +01:00
libof-iterator.mk Rename cppflags-iterator.mk to libof-iterator.mk, remove extra-modules.mk. 2017-05-09 07:06:29 -04:00
o-iterator.mk
shlib-versions Extend NSS test suite 2017-07-17 15:52:44 -04:00
test-skeleton.c Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
version.h Open master for 2.32 development 2020-02-01 17:22:50 +05:30

README

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.

When working with Linux kernels, this version of the GNU C Library
requires Linux kernel version 3.2 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
	csky-*-linux-gnuabiv2
	hppa-*-linux-gnu
	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
	riscv64-*-linux-gnu
	sh[34]-*-linux-gnu
	sparc*-*-linux-gnu
	sparc64*-*-linux-gnu

If you are interested in doing a port, please contact the glibc
maintainers; see https://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 https://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 https://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.