binutils-gdb/config/tls.m4

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dnl Check whether the target supports TLS.
AC_DEFUN([GCC_CHECK_TLS], [
AC_REQUIRE([AC_CANONICAL_HOST])
GCC_ENABLE(tls, yes, [], [Use thread-local storage])
AC_CACHE_CHECK([whether the target supports thread-local storage],
gcc_cv_have_tls, [
AC_RUN_IFELSE([AC_LANG_SOURCE([__thread int a; int b; int main() { return a = b; }])],
[dnl If the test case passed with dynamic linking, try again with
dnl static linking, but only if static linking is supported (not
dnl on Solaris 10). This fails with some older Red Hat releases.
chktls_save_LDFLAGS="$LDFLAGS"
LDFLAGS="-static $LDFLAGS"
AC_LINK_IFELSE([AC_LANG_SOURCE([int main() { return 0; }])],
[AC_RUN_IFELSE([AC_LANG_SOURCE([__thread int a; int b; int main() { return a = b; }])],
[gcc_cv_have_tls=yes], [gcc_cv_have_tls=no],[])],
[gcc_cv_have_tls=yes])
LDFLAGS="$chktls_save_LDFLAGS"
if test $gcc_cv_have_tls = yes; then
dnl So far, the binutils and the compiler support TLS.
dnl Also check whether the libc supports TLS, i.e. whether a variable
dnl with __thread linkage has a different address in different threads.
dnl First, find the thread_CFLAGS necessary for linking a program that
dnl calls pthread_create.
chktls_save_CFLAGS="$CFLAGS"
thread_CFLAGS=failed
for flag in '' '-pthread' '-lpthread'; do
CFLAGS="$flag $chktls_save_CFLAGS"
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[#include <pthread.h>
void *g(void *d) { return NULL; }],
[pthread_t t; pthread_create(&t,NULL,g,NULL);])],
[thread_CFLAGS="$flag"])
if test "X$thread_CFLAGS" != Xfailed; then
break
fi
done
CFLAGS="$chktls_save_CFLAGS"
if test "X$thread_CFLAGS" != Xfailed; then
CFLAGS="$thread_CFLAGS $chktls_save_CFLAGS"
dnl Test for an old glibc bug that violated the __thread property.
dnl Use volatile to ensure the compiler won't optimize away pointer
dnl accesses it might otherwise assume to be redundant, or reorder
dnl them and reuse storage, which might lead to them pointing to
dnl the same location.
AC_RUN_IFELSE(
[AC_LANG_PROGRAM(
[#include <pthread.h>
__thread int a;
static int *volatile a_in_other_thread;
static void *
thread_func (void *arg)
{
a_in_other_thread = &a;
return (void *)0;
}],
[pthread_t thread;
void *thread_retval;
int *volatile a_in_main_thread;
a_in_main_thread = &a;
if (pthread_create (&thread, (pthread_attr_t *)0,
thread_func, (void *)0))
return 0;
if (pthread_join (thread, &thread_retval))
return 0;
return (a_in_other_thread == a_in_main_thread);])],
[gcc_cv_have_tls=yes], [gcc_cv_have_tls=no], [])
CFLAGS="$chktls_save_CFLAGS"
fi
fi],
[gcc_cv_have_tls=no],
[dnl This is the cross-compiling case. Assume libc supports TLS if the
dnl binutils and the compiler do.
AC_LINK_IFELSE([AC_LANG_SOURCE([__thread int a; int b; int main() { return a = b; }])],
[chktls_save_LDFLAGS="$LDFLAGS"
dnl Shared library options may depend on the host; this check
dnl is only known to be needed for GNU/Linux.
case $host in
Merge changes from GCC for the config/ directory GCC's config/ChangeLog since the last time this merge was done (in the binutils-gdb commit 0b4d000cc4e8e77c823) is included at the end of this commit message. It is worth noting that the binutils-gdb commit 301a9420d947da1458 added the file config/debuginfod.m4 which is not present in GCC's config/ directory. This file is preserved, unmodified, after this commit. In order to regenerate all of the configure files, I configured with --enable-maintainer-mode, and built the 'all' target. I then did the same thing on a source tree without this patch, and only committed those files that changed when this patch was added. GCC's config/ChangeLog entries: 2020-02-12 Sandra Loosemore <sandra@codesourcery.com> PR libstdc++/79193 PR libstdc++/88999 * no-executables.m4: Use a non-empty program to test for linker support. 2020-02-01 Andrew Burgess <andrew.burgess@embecosm.com> * lib-link.m4 (AC_LIB_LINKFLAGS_BODY): Update shell syntax. 2020-01-27 Andrew Burgess <andrew.burgess@embecosm.com> * lib-link.m4 (AC_LIB_LINKFLAGS_BODY): Add new --with-libXXX-type=... option. Use this to guide the selection of either a shared library or a static library. 2020-01-24 Maciej W. Rozycki <macro@wdc.com> * toolexeclibdir.m4: New file. 2019-09-10 Christophe Lyon <christophe.lyon@st.com> * futex.m4: Handle *-uclinux*. * tls.m4 (GCC_CHECK_TLS): Likewise. 2019-09-06 Florian Weimer <fweimer@redhat.com> * futex.m4 (GCC_LINUX_FUTEX): Include <unistd.h> for the syscall function. 2019-07-08 Richard Sandiford <richard.sandiford@arm.com> * bootstrap-Og.mk: New file. 2019-06-25 Kwok Cheung Yeung <kcy@codesourcery.com> Andrew Stubbs <ams@codesourcery.com> * gthr.m4 (GCC_AC_THREAD_HEADER): Add case for gcn. 2019-05-30 Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE> * ax_count_cpus.m4: New file. 2019-05-02 Richard Biener <rguenther@suse.de> PR bootstrap/85574 * bootstrap-lto.mk (extra-compare): Set to gcc/lto1$(exeext). 2019-04-16 Martin Liska <mliska@suse.cz> * bootstrap-lto-lean.mk: Filter out -flto in STAGEtrain_CFLAGS. 2019-04-09 Martin Liska <mliska@suse.cz> * bootstrap-lto-lean.mk: New file. 2019-03-02 Johannes Pfau <johannespfau@gmail.com> * mh-mingw: Also set __USE_MINGW_ACCESS flag for C++ code. 2018-10-31 Joseph Myers <joseph@codesourcery.com> PR bootstrap/82856 * math.m4, tls.m4: Use AC_LANG_SOURCE. Merge from binutils-gdb: 2018-06-19 Simon Marchi <simon.marchi@ericsson.com> * override.m4 (_GCC_AUTOCONF_VERSION): Bump from 2.64 to 2.69. config/ChangeLog: * ax_count_cpus.m4: New file, backported from GCC. * bootstrap-Og.mk: New file, backported from GCC. * bootstrap-lto-lean.mk: New file, backported from GCC. * bootstrap-lto.mk: Changes backported from GCC. * futex.m4: Changes backported from GCC. * gthr.m4: Changes backported from GCC. * lib-link.m4: Changes backported from GCC. * mh-mingw: Changes backported from GCC. * no-executables.m4: Changes backported from GCC. * tls.m4: Changes backported from GCC. * toolexeclibdir.m4: New file, backported from GCC. binutils/ChangeLog: * configure: Regenerate. gdb/ChangeLog: * configure: Regenerate. gdbserver/ChangeLog: * configure: Regenerate. gdbsupport/ChangeLog: * configure: Regenerate. intl/ChangeLog: * configure: Regenerate. libiberty/ChangeLog: * configure: Regenerate. zlib/ChangeLog.bin-gdb: * configure: Regenerate.
2020-02-05 12:50:07 +01:00
*-*-linux* | -*-uclinuxfdpic*)
LDFLAGS="-shared -Wl,--no-undefined $LDFLAGS"
;;
esac
chktls_save_CFLAGS="$CFLAGS"
CFLAGS="-fPIC $CFLAGS"
dnl If -shared works, test if TLS works in a shared library.
AC_LINK_IFELSE([AC_LANG_SOURCE([int f() { return 0; }])],
[AC_LINK_IFELSE([AC_LANG_SOURCE([__thread int a; int b; int f() { return a = b; }])],
[gcc_cv_have_tls=yes],
[gcc_cv_have_tls=no])],
[gcc_cv_have_tls=yes])
CFLAGS="$chktls_save_CFLAGS"
LDFLAGS="$chktls_save_LDFLAGS"], [gcc_cv_have_tls=no])
]
)])
if test "$enable_tls $gcc_cv_have_tls" = "yes yes"; then
AC_DEFINE(HAVE_TLS, 1,
[Define to 1 if the target supports thread-local storage.])
fi])
dnl Check whether the target assembler supports TLS.
AC_DEFUN([GCC_CHECK_CC_TLS], [
GCC_ENABLE(tls, yes, [], [Use thread-local storage])
AC_CACHE_CHECK([whether the target assembler supports thread-local storage],
gcc_cv_have_cc_tls, [
AC_COMPILE_IFELSE([AC_LANG_SOURCE([__thread int a; int b; int main() { return a = b; }])],
[gcc_cv_have_cc_tls=yes], [gcc_cv_have_cc_tls=no])]
)])
if test "$enable_tls $gcc_cv_have_cc_tls" = "yes yes"; then
AC_DEFINE(HAVE_CC_TLS, 1,
[Define to 1 if the target assembler supports thread-local storage.])
fi])
dnl Check whether TLS is emulated.
AC_DEFUN([GCC_CHECK_EMUTLS], [
AC_CACHE_CHECK([whether the thread-local storage support is from emutls],
gcc_cv_use_emutls, [
gcc_cv_use_emutls=no
echo '__thread int a; int b; int main() { return a = b; }' > conftest.c
if AC_TRY_COMMAND(${CC-cc} -Werror -S -o conftest.s conftest.c 1>&AS_MESSAGE_LOG_FD); then
if grep __emutls_get_address conftest.s > /dev/null; then
gcc_cv_use_emutls=yes
fi
fi
rm -f conftest.*
])
if test "$gcc_cv_use_emutls" = "yes" ; then
AC_DEFINE(USE_EMUTLS, 1,
[Define to 1 if the target use emutls for thread-local storage.])
fi])