gcc/libgomp/acinclude.m4

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dnl ----------------------------------------------------------------------
dnl This whole bit snagged from libgfortran.
dnl Check whether the target supports __sync_*_compare_and_swap.
AC_DEFUN([LIBGOMP_CHECK_SYNC_BUILTINS], [
AC_CACHE_CHECK([whether the target supports __sync_*_compare_and_swap],
have_sync_builtins, [
AC_TRY_LINK([], [int foo, bar; bar = __sync_val_compare_and_swap(&foo, 0, 1);],
have_sync_builtins=yes, have_sync_builtins=no)])
if test $have_sync_builtins = yes; then
AC_DEFINE(HAVE_SYNC_BUILTINS, 1,
[Define to 1 if the target supports __sync_*_compare_and_swap])
fi])
dnl Check whether the target supports hidden visibility.
AC_DEFUN([LIBGOMP_CHECK_ATTRIBUTE_VISIBILITY], [
AC_CACHE_CHECK([whether the target supports hidden visibility],
have_attribute_visibility, [
save_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -Werror"
AC_TRY_COMPILE([void __attribute__((visibility("hidden"))) foo(void) { }],
[], have_attribute_visibility=yes,
have_attribute_visibility=no)
CFLAGS="$save_CFLAGS"])
if test $have_attribute_visibility = yes; then
AC_DEFINE(HAVE_ATTRIBUTE_VISIBILITY, 1,
[Define to 1 if the target supports __attribute__((visibility(...))).])
fi])
dnl Check whether the target supports dllexport
AC_DEFUN([LIBGOMP_CHECK_ATTRIBUTE_DLLEXPORT], [
AC_CACHE_CHECK([whether the target supports dllexport],
have_attribute_dllexport, [
save_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -Werror"
AC_TRY_COMPILE([void __attribute__((dllexport)) foo(void) { }],
[], have_attribute_dllexport=yes,
have_attribute_dllexport=no)
CFLAGS="$save_CFLAGS"])
if test $have_attribute_dllexport = yes; then
AC_DEFINE(HAVE_ATTRIBUTE_DLLEXPORT, 1,
[Define to 1 if the target supports __attribute__((dllexport)).])
fi])
dnl Check whether the target supports symbol aliases.
AC_DEFUN([LIBGOMP_CHECK_ATTRIBUTE_ALIAS], [
AC_CACHE_CHECK([whether the target supports symbol aliases],
have_attribute_alias, [
AC_TRY_LINK([
#define ULP STR1(__USER_LABEL_PREFIX__)
#define STR1(x) STR2(x)
#define STR2(x) #x
void foo(void) { }
extern void bar(void) __attribute__((alias(ULP "foo")));],
[bar();], have_attribute_alias=yes, have_attribute_alias=no)])
if test $have_attribute_alias = yes; then
AC_DEFINE(HAVE_ATTRIBUTE_ALIAS, 1,
[Define to 1 if the target supports __attribute__((alias(...))).])
fi])
sinclude(../libtool.m4)
dnl The lines below arrange for aclocal not to bring an installed
dnl libtool.m4 into aclocal.m4, while still arranging for automake to
dnl add a definition of LIBTOOL to Makefile.in.
ifelse(,,,[AC_SUBST(LIBTOOL)
AC_DEFUN([AM_PROG_LIBTOOL])
AC_DEFUN([AC_LIBTOOL_DLOPEN])
AC_DEFUN([AC_PROG_LD])
])
dnl ----------------------------------------------------------------------
dnl This whole bit snagged from libstdc++-v3.
dnl
dnl LIBGOMP_ENABLE
dnl (FEATURE, DEFAULT, HELP-ARG, HELP-STRING)
dnl (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, permit a|b|c)
dnl (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, SHELL-CODE-HANDLER)
dnl
dnl See docs/html/17_intro/configury.html#enable for documentation.
dnl
m4_define([LIBGOMP_ENABLE],[dnl
m4_define([_g_switch],[--enable-$1])dnl
m4_define([_g_help],[AC_HELP_STRING(_g_switch$3,[$4 @<:@default=$2@:>@])])dnl
AC_ARG_ENABLE($1,_g_help,
m4_bmatch([$5],
[^permit ],
[[
case "$enableval" in
m4_bpatsubst([$5],[permit ])) ;;
*) AC_MSG_ERROR(Unknown argument to enable/disable $1) ;;
dnl Idea for future: generate a URL pointing to
dnl "onlinedocs/configopts.html#whatever"
esac
]],
[^$],
[[
case "$enableval" in
yes|no) ;;
*) AC_MSG_ERROR(Argument to enable/disable $1 must be yes or no) ;;
esac
]],
[[$5]]),
[enable_]m4_bpatsubst([$1],-,_)[=][$2])
m4_undefine([_g_switch])dnl
m4_undefine([_g_help])dnl
])
dnl
dnl If GNU ld is in use, check to see if tricky linker opts can be used. If
dnl the native linker is in use, all variables will be defined to something
dnl safe (like an empty string).
dnl
dnl Defines:
dnl SECTION_LDFLAGS='-Wl,--gc-sections' if possible
dnl OPT_LDFLAGS='-Wl,-O1' if possible
dnl LD (as a side effect of testing)
dnl Sets:
dnl with_gnu_ld
dnl libgomp_gnu_ld_version (possibly)
dnl
dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will
dnl set libgomp_gnu_ld_version to 12345. Zeros cause problems.
dnl
AC_DEFUN([LIBGOMP_CHECK_LINKER_FEATURES], [
# If we're not using GNU ld, then there's no point in even trying these
# tests. Check for that first. We should have already tested for gld
# by now (in libtool), but require it now just to be safe...
test -z "$SECTION_LDFLAGS" && SECTION_LDFLAGS=''
test -z "$OPT_LDFLAGS" && OPT_LDFLAGS=''
AC_REQUIRE([AC_PROG_LD])
AC_REQUIRE([AC_PROG_AWK])
# The name set by libtool depends on the version of libtool. Shame on us
# for depending on an impl detail, but c'est la vie. Older versions used
# ac_cv_prog_gnu_ld, but now it's lt_cv_prog_gnu_ld, and is copied back on
# top of with_gnu_ld (which is also set by --with-gnu-ld, so that actually
# makes sense). We'll test with_gnu_ld everywhere else, so if that isn't
# set (hence we're using an older libtool), then set it.
if test x${with_gnu_ld+set} != xset; then
if test x${ac_cv_prog_gnu_ld+set} != xset; then
# We got through "ac_require(ac_prog_ld)" and still not set? Huh?
with_gnu_ld=no
else
with_gnu_ld=$ac_cv_prog_gnu_ld
fi
fi
# Start by getting the version number. I think the libtool test already
# does some of this, but throws away the result.
changequote(,)
ldver=`$LD --version 2>/dev/null | head -1 | \
sed -e 's/GNU ld version \([0-9.][0-9.]*\).*/\1/'`
changequote([,])
libgomp_gnu_ld_version=`echo $ldver | \
$AWK -F. '{ if (NF<3) [$]3=0; print ([$]1*100+[$]2)*100+[$]3 }'`
# Set --gc-sections.
if test "$with_gnu_ld" = "notbroken"; then
# GNU ld it is! Joy and bunny rabbits!
# All these tests are for C++; save the language and the compiler flags.
# Need to do this so that g++ won't try to link in libstdc++
ac_test_CFLAGS="${CFLAGS+set}"
ac_save_CFLAGS="$CFLAGS"
CFLAGS='-x c++ -Wl,--gc-sections'
# Check for -Wl,--gc-sections
# XXX This test is broken at the moment, as symbols required for linking
# are now in libsupc++ (not built yet). In addition, this test has
# cored on solaris in the past. In addition, --gc-sections doesn't
# really work at the moment (keeps on discarding used sections, first
# .eh_frame and now some of the glibc sections for iconv).
# Bzzzzt. Thanks for playing, maybe next time.
AC_MSG_CHECKING([for ld that supports -Wl,--gc-sections])
AC_TRY_RUN([
int main(void)
{
try { throw 1; }
catch (...) { };
return 0;
}
], [ac_sectionLDflags=yes],[ac_sectionLDflags=no], [ac_sectionLDflags=yes])
if test "$ac_test_CFLAGS" = set; then
CFLAGS="$ac_save_CFLAGS"
else
# this is the suspicious part
CFLAGS=''
fi
if test "$ac_sectionLDflags" = "yes"; then
SECTION_LDFLAGS="-Wl,--gc-sections $SECTION_LDFLAGS"
fi
AC_MSG_RESULT($ac_sectionLDflags)
fi
# Set linker optimization flags.
if test x"$with_gnu_ld" = x"yes"; then
OPT_LDFLAGS="-Wl,-O1 $OPT_LDFLAGS"
fi
AC_SUBST(SECTION_LDFLAGS)
AC_SUBST(OPT_LDFLAGS)
])
dnl
dnl Add version tags to symbols in shared library (or not), additionally
dnl marking other symbols as private/local (or not).
dnl
dnl --enable-symvers=style adds a version script to the linker call when
dnl creating the shared library. The choice of version script is
dnl controlled by 'style'.
dnl --disable-symvers does not.
dnl + Usage: LIBGOMP_ENABLE_SYMVERS[(DEFAULT)]
dnl Where DEFAULT is either 'yes' or 'no'. Passing `yes' tries to
dnl choose a default style based on linker characteristics. Passing
dnl 'no' disables versioning.
dnl
AC_DEFUN([LIBGOMP_ENABLE_SYMVERS], [
LIBGOMP_ENABLE(symvers,yes,[=STYLE],
[enables symbol versioning of the shared library],
[permit yes|no|gnu])
# If we never went through the LIBGOMP_CHECK_LINKER_FEATURES macro, then we
# don't know enough about $LD to do tricks...
AC_REQUIRE([LIBGOMP_CHECK_LINKER_FEATURES])
# FIXME The following test is too strict, in theory.
if test $enable_shared = no ||
test "x$LD" = x ||
test x$libgomp_gnu_ld_version = x; then
enable_symvers=no
fi
# Check to see if libgcc_s exists, indicating that shared libgcc is possible.
if test $enable_symvers != no; then
AC_MSG_CHECKING([for shared libgcc])
ac_save_CFLAGS="$CFLAGS"
CFLAGS=' -lgcc_s'
AC_TRY_LINK(, [return 0;], libgomp_shared_libgcc=yes, libgomp_shared_libgcc=no)
CFLAGS="$ac_save_CFLAGS"
if test $libgomp_shared_libgcc = no; then
cat > conftest.c <<EOF
int main (void) { return 0; }
EOF
changequote(,)dnl
libgomp_libgcc_s_suffix=`${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS \
-shared -shared-libgcc -o conftest.so \
conftest.c -v 2>&1 >/dev/null \
| sed -n 's/^.* -lgcc_s\([^ ]*\) .*$/\1/p'`
changequote([,])dnl
rm -f conftest.c conftest.so
if test x${libgomp_libgcc_s_suffix+set} = xset; then
CFLAGS=" -lgcc_s$libgomp_libgcc_s_suffix"
AC_TRY_LINK(, [return 0;], libgomp_shared_libgcc=yes)
CFLAGS="$ac_save_CFLAGS"
fi
fi
AC_MSG_RESULT($libgomp_shared_libgcc)
fi
# For GNU ld, we need at least this version. The format is described in
# LIBGOMP_CHECK_LINKER_FEATURES above.
libgomp_min_gnu_ld_version=21400
# XXXXXXXXXXX libgomp_gnu_ld_version=21390
# Check to see if unspecified "yes" value can win, given results above.
# Change "yes" into either "no" or a style name.
if test $enable_symvers = yes; then
if test $with_gnu_ld = yes &&
test $libgomp_shared_libgcc = yes;
then
if test $libgomp_gnu_ld_version -ge $libgomp_min_gnu_ld_version ; then
enable_symvers=gnu
else
# The right tools, the right setup, but too old. Fallbacks?
AC_MSG_WARN(=== Linker version $libgomp_gnu_ld_version is too old for)
AC_MSG_WARN(=== full symbol versioning support in this release of GCC.)
AC_MSG_WARN(=== You would need to upgrade your binutils to version)
AC_MSG_WARN(=== $libgomp_min_gnu_ld_version or later and rebuild GCC.)
if test $libgomp_gnu_ld_version -ge 21200 ; then
# Globbing fix is present, proper block support is not.
dnl AC_MSG_WARN([=== Dude, you are soooo close. Maybe we can fake it.])
dnl enable_symvers=???
AC_MSG_WARN([=== Symbol versioning will be disabled.])
enable_symvers=no
else
# 2.11 or older.
AC_MSG_WARN([=== Symbol versioning will be disabled.])
enable_symvers=no
fi
fi
else
# just fail for now
AC_MSG_WARN([=== You have requested some kind of symbol versioning, but])
AC_MSG_WARN([=== either you are not using a supported linker, or you are])
AC_MSG_WARN([=== not building a shared libgcc_s (which is required).])
AC_MSG_WARN([=== Symbol versioning will be disabled.])
enable_symvers=no
fi
fi
AM_CONDITIONAL(LIBGOMP_BUILD_VERSIONED_SHLIB, test $enable_symvers != no)
AC_MSG_NOTICE(versioning on shared library symbols is $enable_symvers)
])