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  • Committer: Bazaar Package Importer
  • Author(s): Hubert Chathi
  • Date: 2007-10-10 15:33:10 UTC
  • mto: (9.2.5 sid)
  • mto: This revision was merged to the branch mainline in revision 15.
  • Revision ID: james.westby@ubuntu.com-20071010153310-h3holq75eu2cigb0
Tags: upstream-0.99.80~rc4
Import upstream version 0.99.80~rc4

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m4/visibility.m4
 
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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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])