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1.2.16
by Reinhard Tartler
Import upstream version 0.9.2 |
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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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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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dnl From Bruno Haible. |
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dnl Tests whether the compiler supports the command-line option |
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dnl -fvisibility=hidden and the function and variable attributes |
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dnl __attribute__((__visibility__("hidden"))) and |
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dnl __attribute__((__visibility__("default"))). |
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dnl Does *not* test for __visibility__("protected") - which has tricky |
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dnl semantics (see the 'vismain' test in glibc) and does not exist e.g. on |
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dnl MacOS X. |
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dnl Does *not* test for __visibility__("internal") - which has processor |
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dnl dependent semantics. |
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dnl Does *not* test for #pragma GCC visibility push(hidden) - which is |
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dnl "really only recommended for legacy code". |
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dnl Set the variable CFLAG_VISIBILITY. |
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dnl Defines and sets the variable HAVE_VISIBILITY. |
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AC_DEFUN([gl_VISIBILITY], |
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[
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AC_REQUIRE([AC_PROG_CC]) |
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CFLAG_VISIBILITY= |
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HAVE_VISIBILITY=0 |
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if test -n "$GCC"; then |
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AC_MSG_CHECKING([for simple visibility declarations]) |
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AC_CACHE_VAL(gl_cv_cc_visibility, [ |
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gl_save_CFLAGS="$CFLAGS" |
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CFLAGS="$CFLAGS -fvisibility=hidden" |
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AC_TRY_COMPILE( |
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[extern __attribute__((__visibility__("hidden"))) int hiddenvar; |
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extern __attribute__((__visibility__("default"))) int exportedvar; |
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extern __attribute__((__visibility__("hidden"))) int hiddenfunc (void); |
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extern __attribute__((__visibility__("default"))) int exportedfunc (void);], |
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[],
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gl_cv_cc_visibility=yes, |
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gl_cv_cc_visibility=no) |
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CFLAGS="$gl_save_CFLAGS"]) |
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AC_MSG_RESULT([$gl_cv_cc_visibility]) |
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if test $gl_cv_cc_visibility = yes; then |
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CFLAG_VISIBILITY="-fvisibility=hidden" |
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HAVE_VISIBILITY=1 |
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fi
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fi
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AC_SUBST([CFLAG_VISIBILITY]) |
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AC_SUBST([HAVE_VISIBILITY]) |
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AC_DEFINE_UNQUOTED([HAVE_VISIBILITY], [$HAVE_VISIBILITY], |
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[Define to 1 or 0, depending whether the compiler supports simple visibility declarations.]) |
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])
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