diff options
Diffstat (limited to 'm4/visibility_hidden.m4')
| -rw-r--r-- | m4/visibility_hidden.m4 | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/m4/visibility_hidden.m4 b/m4/visibility_hidden.m4 new file mode 100644 index 0000000..dbd57d4 --- /dev/null +++ b/m4/visibility_hidden.m4 @@ -0,0 +1,40 @@ +dnl Copyright (C) 2003, 2008 Silicon Graphics, Inc. +dnl +dnl This program is free software: you can redistribute it and/or modify it +dnl under the terms of the GNU General Public License as published by +dnl the Free Software Foundation, either version 2 of the License, or +dnl (at your option) any later version. +dnl +dnl This program is distributed in the hope that it will be useful, +dnl but WITHOUT ANY WARRANTY; without even the implied warranty of +dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +dnl GNU General Public License for more details. +dnl +dnl You should have received a copy of the GNU General Public License +dnl along with this program. If not, see <http://www.gnu.org/licenses/>. +AC_DEFUN([AC_FUNC_GCC_VISIBILITY], + [AC_CACHE_CHECK(whether __attribute__((visibility())) is supported, + libc_cv_visibility_attribute, + [cat > conftest.c <<EOF + int foo __attribute__ ((visibility ("hidden"))) = 1; + int bar __attribute__ ((visibility ("protected"))) = 1; +EOF + libc_cv_visibility_attribute=no + if ${CC-cc} -Werror -S conftest.c -o conftest.s \ + >/dev/null 2>&1; then + if grep '\.hidden.*foo' conftest.s >/dev/null; then + if grep '\.protected.*bar' conftest.s >/dev/null; then + libc_cv_visibility_attribute=yes + fi + fi + fi + rm -f conftest.[cs] + ]) + if test $libc_cv_visibility_attribute = yes; then + AC_DEFINE(HAVE_VISIBILITY_ATTRIBUTE, [], [GCC supports visibility attributes]) + AC_DEFINE(EXPORT, [__attribute__ ((visibility ("default"))) extern], [Visibility attribute for API symbols]) + CFLAGS="${CFLAGS} -fvisibility=hidden" + else + AC_DEFINE(EXPORT, [extern], [Visibility attribute for API symbols]) + fi + ]) |