gcc/libstdc++-v3/mkcshadow

#!/usr/bin/env bash

# mkcshadow: reads header names (like "features.h" or "sys/types.h")
#   from stdin, and creates shadow headers under cshadow/, except where
#   a header of the same name is already in shadow/.

SCRIPTDIR=${0%/*}

if [ ! -d cshadow ]; then
  echo "Creating cshadow."
  mkdir ../cshadow
fi

echo "Creating..."
while read header; do

  if [ ! -f $SCRIPTDIR/shadow/$header ]; then

    # strip off directory names while making 
    #   any necessary directories

    dir=../cshadow
    case "$header" in */*)
      right="$header"
      while [ "$right" != "${right##*/}" ] ; do
        dir="$dir/${right%%/*}"
        if [ ! -d "$dir" ]; then mkdir "$dir"; fi
        right="${right#*/}"
      done
      ;;
    esac

    echo "  ../cshadow/$header"
    UPNAME=`echo $header | tr 'a-z./-' 'A-Z___'`
    cat >"../cshadow/$header" <<EOF
// -*- C++ -*- header wrapper.

// Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.

// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.

// Note: this file was automatically generated by the "mkcshadow"
//       script.  RTFM!

#ifndef  _INCLUDED_CPP_${UPNAME}_
# define _INCLUDED_CPP_${UPNAME}_

# ifdef _IN_C_LEGACY_  /* sub-included by a C header */
#   pragma GCC system_header
#   include_next <${header}>
# else

    namespace _C_legacy { namespace _C_shadow { } }
    using namespace ::_C_legacy::_C_shadow;
    namespace _C_legacy {
      extern "C" {
#       define _IN_C_LEGACY_
#       pragma GCC system_header
#       include_next <${header}>
      } // close extern "C"
    }   // close namespace _C_legacy::
# undef _IN_C_LEGACY_
  
# endif /* _IN_C_LEGACY_ */
#endif /* _INCLUDED_CPP_${UPNAME}_ */
EOF
#################### end ####################
  fi
done