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# visibility.m4 serial 1 (gettext-0.15)
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dnl Copyright (C) 2005 Free Software Foundation, Inc.
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# visibility.m4 serial 3 (gettext-0.18)
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dnl Copyright (C) 2005, 2008-2010 Free Software Foundation, Inc.
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dnl This file is free software; the Free Software Foundation
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dnl gives unlimited permission to copy and/or distribute it,
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dnl with or without modifications, as long as this notice is preserved.
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if test -n "$GCC"; then
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dnl First, check whether -Werror can be added to the command line, or
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dnl whether it leads to an error because of some other option that the
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dnl user has put into $CC $CFLAGS $CPPFLAGS.
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AC_MSG_CHECKING([whether the -Werror option is usable])
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AC_CACHE_VAL([gl_cv_cc_vis_werror], [
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gl_save_CFLAGS="$CFLAGS"
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CFLAGS="$CFLAGS -Werror"
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AC_TRY_COMPILE([], [],
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[gl_cv_cc_vis_werror=yes],
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[gl_cv_cc_vis_werror=no])
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CFLAGS="$gl_save_CFLAGS"])
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AC_MSG_RESULT([$gl_cv_cc_vis_werror])
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dnl Now check whether visibility declarations are supported.
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AC_MSG_CHECKING([for simple visibility declarations])
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AC_CACHE_VAL(gl_cv_cc_visibility, [
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AC_CACHE_VAL([gl_cv_cc_visibility], [
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gl_save_CFLAGS="$CFLAGS"
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CFLAGS="$CFLAGS -fvisibility=hidden"
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dnl We use the option -Werror and a function dummyfunc, because on some
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dnl platforms (Cygwin 1.7) the use of -fvisibility triggers a warning
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dnl "visibility attribute not supported in this configuration; ignored"
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dnl at the first function definition in every compilation unit, and we
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dnl don't want to use the option in this case.
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if test $gl_cv_cc_vis_werror = yes; then
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CFLAGS="$CFLAGS -Werror"
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[extern __attribute__((__visibility__("hidden"))) int hiddenvar;
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extern __attribute__((__visibility__("default"))) int exportedvar;
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extern __attribute__((__visibility__("hidden"))) int hiddenfunc (void);
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extern __attribute__((__visibility__("default"))) int exportedfunc (void);],
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extern __attribute__((__visibility__("default"))) int exportedfunc (void);
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void dummyfunc (void) {}],
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gl_cv_cc_visibility=yes,
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gl_cv_cc_visibility=no)
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[gl_cv_cc_visibility=yes],
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[gl_cv_cc_visibility=no])
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CFLAGS="$gl_save_CFLAGS"])
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AC_MSG_RESULT([$gl_cv_cc_visibility])
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if test $gl_cv_cc_visibility = yes; then