version 1.1.1.1, 2012/02/21 22:57:49
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version 1.1.1.3, 2021/03/17 13:38:46
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# visibility.m4 serial 2 (gettext-0.18) | # visibility.m4 serial 6 |
dnl Copyright (C) 2005, 2008 Free Software Foundation, Inc. | dnl Copyright (C) 2005, 2008, 2010-2019 Free Software Foundation, Inc. |
dnl This file is free software; the Free Software Foundation |
dnl This file is free software; the Free Software Foundation |
dnl gives unlimited permission to copy and/or distribute it, |
dnl gives unlimited permission to copy and/or distribute it, |
dnl with or without modifications, as long as this notice is preserved. |
dnl with or without modifications, as long as this notice is preserved. |
Line 12 dnl __attribute__((__visibility__("hidden"))) and
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Line 12 dnl __attribute__((__visibility__("hidden"))) and
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dnl __attribute__((__visibility__("default"))). |
dnl __attribute__((__visibility__("default"))). |
dnl Does *not* test for __visibility__("protected") - which has tricky |
dnl Does *not* test for __visibility__("protected") - which has tricky |
dnl semantics (see the 'vismain' test in glibc) and does not exist e.g. on |
dnl semantics (see the 'vismain' test in glibc) and does not exist e.g. on |
dnl MacOS X. | dnl Mac OS X. |
dnl Does *not* test for __visibility__("internal") - which has processor |
dnl Does *not* test for __visibility__("internal") - which has processor |
dnl dependent semantics. |
dnl dependent semantics. |
dnl Does *not* test for #pragma GCC visibility push(hidden) - which is |
dnl Does *not* test for #pragma GCC visibility push(hidden) - which is |
Line 26 AC_DEFUN([gl_VISIBILITY],
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Line 26 AC_DEFUN([gl_VISIBILITY],
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CFLAG_VISIBILITY= |
CFLAG_VISIBILITY= |
HAVE_VISIBILITY=0 |
HAVE_VISIBILITY=0 |
if test -n "$GCC"; then |
if test -n "$GCC"; then |
AC_MSG_CHECKING([for simple visibility declarations]) | dnl First, check whether -Werror can be added to the command line, or |
AC_CACHE_VAL([gl_cv_cc_visibility], [ | dnl whether it leads to an error because of some other option that the |
gl_save_CFLAGS="$CFLAGS" | dnl user has put into $CC $CFLAGS $CPPFLAGS. |
CFLAGS="$CFLAGS -fvisibility=hidden" | AC_CACHE_CHECK([whether the -Werror option is usable], |
AC_TRY_COMPILE( | [gl_cv_cc_vis_werror], |
[extern __attribute__((__visibility__("hidden"))) int hiddenvar; | [gl_save_CFLAGS="$CFLAGS" |
extern __attribute__((__visibility__("default"))) int exportedvar; | CFLAGS="$CFLAGS -Werror" |
extern __attribute__((__visibility__("hidden"))) int hiddenfunc (void); | AC_COMPILE_IFELSE( |
extern __attribute__((__visibility__("default"))) int exportedfunc (void);], | [AC_LANG_PROGRAM([[]], [[]])], |
[], | [gl_cv_cc_vis_werror=yes], |
[gl_cv_cc_visibility=yes], | [gl_cv_cc_vis_werror=no]) |
[gl_cv_cc_visibility=no]) | CFLAGS="$gl_save_CFLAGS" |
CFLAGS="$gl_save_CFLAGS"]) | ]) |
AC_MSG_RESULT([$gl_cv_cc_visibility]) | dnl Now check whether visibility declarations are supported. |
| AC_CACHE_CHECK([for simple visibility declarations], |
| [gl_cv_cc_visibility], |
| [gl_save_CFLAGS="$CFLAGS" |
| CFLAGS="$CFLAGS -fvisibility=hidden" |
| dnl We use the option -Werror and a function dummyfunc, because on some |
| dnl platforms (Cygwin 1.7) the use of -fvisibility triggers a warning |
| dnl "visibility attribute not supported in this configuration; ignored" |
| dnl at the first function definition in every compilation unit, and we |
| dnl don't want to use the option in this case. |
| if test $gl_cv_cc_vis_werror = yes; then |
| CFLAGS="$CFLAGS -Werror" |
| fi |
| AC_COMPILE_IFELSE( |
| [AC_LANG_PROGRAM( |
| [[extern __attribute__((__visibility__("hidden"))) int hiddenvar; |
| extern __attribute__((__visibility__("default"))) int exportedvar; |
| extern __attribute__((__visibility__("hidden"))) int hiddenfunc (void); |
| extern __attribute__((__visibility__("default"))) int exportedfunc (void); |
| void dummyfunc (void) {} |
| ]], |
| [[]])], |
| [gl_cv_cc_visibility=yes], |
| [gl_cv_cc_visibility=no]) |
| CFLAGS="$gl_save_CFLAGS" |
| ]) |
if test $gl_cv_cc_visibility = yes; then |
if test $gl_cv_cc_visibility = yes; then |
CFLAG_VISIBILITY="-fvisibility=hidden" |
CFLAG_VISIBILITY="-fvisibility=hidden" |
HAVE_VISIBILITY=1 |
HAVE_VISIBILITY=1 |