text: # @synopsis AX_CHECK_EXPORT_CAPABILITY
  #
  # Does the compiler support the exporting of library symbols?
  # @version 1.0    Jan 31 2009
  # @author Steve Underwood
  #
  # Permission to use, copy, modify, distribute, and sell this file for any 
  # purpose is hereby granted without fee, provided that the above copyright 
  # and this permission notice appear in all copies.  No representations are
  # made about the suitability of this software for any purpose.  It is 
  # provided "as is" without express or implied warranty.
  
  AC_DEFUN([AX_CHECK_EXPORT_CAPABILITY],
  [AC_CACHE_CHECK([if $1 supports library symbol export], 
      ac_cv_symbol_export_capability,
  
  [# Initialize to unknown
  ac_cv_symbol_export_capability="no"
  
  case "${ax_cv_c_compiler_vendor}" in
  gnu)
      save_CFLAGS="${CFLAGS}"
      CFLAGS="${CFLAGS} -fvisibility=hidden"
      AC_COMPILE_IFELSE(
          [AC_LANG_PROGRAM(
              [int foo __attribute__ ((visibility("default")));],
              [;]
          )],
  
          [AC_MSG_RESULT([yes])
           COMP_VENDOR_CFLAGS="-fvisibility=hidden -DHAVE_VISIBILITY=1 $COMP_VENDOR_CFLAGS"
           COMP_VENDOR_CXXFLAGS="-fvisibility=hidden -DHAVE_VISIBILITY=1 $COMP_VENDOR_CXXFLAGS"
           ac_cv_symbol_export_capability="yes"],
  
          [AC_MSG_RESULT([no])]
      )
      CFLAGS="${save_CFLAGS}"
      ;;
  
  sun)
      save_CFLAGS="${CFLAGS}"
      CFLAGS="${CFLAGS} -xldscope=hidden"
      AC_COMPILE_IFELSE(
          [AC_LANG_PROGRAM(
              [int foo __attribute__ ((visibility("default")));],
              [;]
          )],
  
          [AC_MSG_RESULT([yes])
           COMP_VENDOR_CFLAGS="-xldscope=hidden -DHAVE_VISIBILITY=1 $COMP_VENDOR_CFLAGS"
           COMP_VENDOR_CXXFLAGS="-xldscope=hidden -DHAVE_VISIBILITY=1 $COMP_VENDOR_CXXFLAGS"
           ac_cv_symbol_export_capability="yes"],
  
          [AC_MSG_RESULT([no])]
      )
      CFLAGS="${save_CFLAGS}"
      ;;
  
  esac])
  AS_IF([test AS_VAR_GET(ac_cv_symbol_export_capability) = yes], [$2], [$3])[]dnl
  ]) # AX_CHECK_EXPORT_CAPABILITY
  