path: root/macros/offset-tool.sh.in

#!/bin/sh
#
# offset-tool.sh (C)2000 Peter Williams
#
# This tool is used to pregenerate structure offset
# data for use with Balsa's configuration, because
# it's really constant data although GCC, at least,
# doesn't think so.
#
# To achieve that effect, I have writen this here
# absurdly overcomplicated tool, autoconf macro,
# configure.in code, and Makefile.am :-) There
# might be a simpler way to do this, and I guess
# I'll trade in this cool code for better code,
# but I can't think of a simpler way right now :-)

srcdir="@srcdir@"
top_srcdir="@top_srcdir@"
real_top_srcdir="@BALSA_OFFSET_SRCPATH@"
offset_tool_home="@BALSA_OFFSET_TOOL_HOME@"
top_dots="@BALSA_OFFSET_TOOL_DOTS@"
tool_defs="@BALSA_OFFSET_TOOL_DEFSFILE@"
CPP="@CPP@"
SHELL="@SHELL@"
CC="@CC@"
DEFS="@DEFS@"
CFLAGS="@CFLAGS@"
mid_file=offset-tool.c
no_clean=no

case "${top_srcdir}" in
/*)
    test -f ../../config.status && top_builddir="../.."
    test -f ../config.status && top_builddir=".."
    test -f config.status && top_builddir="."
    ;;
#..)
#    top_builddir=".."
#    real_top_srcdir=".."
#    ;;
#.)
#    top_builddir="."
#    real_top_srcdir"."
#    ;;
*)
    test -f ../../${real_top_srcdir}/configure && top_builddir="../.."
    test -f ../${real_top_srcdir}/configure && top_builddir=".."
    test -f ./${real_top_srcdir}/configure && top_builddir="."
    ;;
esac

case "${real_top_srcdir}" in
/*)
    header_dots="${real_top_srcdir}"
    ;;
*)
    header_dots="${top_dots}${real_top_srcdir}"
    ;;
esac

# Backup top srcdir to be what we want it to be

tmp="${top_srcdir}"
top_srcdir="${header_dots}"

echo top builddir: ${top_builddir}

if test -r "${top_builddir}/${tool_defs}" ; then
    . "${top_builddir}/${tool_defs}"
fi

# Restore the backup

top_srcdir="${tmp}"

usage()
{
    echo "Usage: offset-tool.sh (--help|--create|--makerules|--headername) [--fragname=<fragment name>] [--noclean] <filenames...>"
    echo "Look at $(top_srcdir)/${offset_tool_home}/offset-tool.sh.in for more information"
    exit 1
}

if test -z "$1" ; then
    usage
fi

mode=`echo $1 |sed -e 's,^--,,'`

case $mode in
help)
    usage
    ;;
create)
    ;;
makerules)
    ;;
headername)
    ;;
*)
    echo "Unknown mode $mode"
    usage
    ;;
esac

shift

fragname=

while test $# -gt 0 ; do
    case "${1}" in
	--fragname=*)
	    fragname=`echo ${1} |sed -e 's,.*=\(.*\),\1,'`; shift ;;
	--fragname)
	    shift; fragname="${1}" ; shift ;;
	--noclean)
	    no_clean=yes ; shift ;;
	--)
	    shift; break ;;
	-*)
	    usage ;;
	*)
	    break ;;
    esac
done

test x"$fragname" = x && fragname=Makefragment.offset-tool
infiles=$*

test x"$mode" = xmakerules || echo "Scanning these files for config offsets: $infiles"

header=`cat $infiles |grep "OFFSET HEADER" |sed -e 's,# *include *\"\(.*\)\".*,\1,' |sed -e '1!d'`
if test x"$header" = x ; then
    echo "Couldn't determine the configuration header." 1>&2
    exit 2
fi

if test x"$mode" = xcreate ; then
    echo Removing old header ... 
    echo "/* Nothing */" >${header}

    echo Getting needed defines ...
    defines=`${CPP} ${CFLAGS} $infiles |grep "BALSA_OFFSET_" |sed -e 's|^.*BALSA_OFFSET_\([a-zA-Z0-9_]*\)_ELEM_\([a-zA-Z0-9_]*\).*$|\1--\2|'`
    # Helpers will be in comments, don't chomp them.
    helpers=`cat $infiles |grep "OFFSET DEF" |sed -e 's|^.*OFFSET DEF *\[\[\(.*\)\]\].*$|\1|'`
    
    echo Generating ${mid_file} ...
    cat <<EOF >${mid_file}
/* This file generated by offset-tool.sh. Do not edit! */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#ifdef STDC_HEADERS
#include <stdio.h>
#else
extern void printf( char *, ... );
#endif

EOF

    echo >>${mid_file}
    echo "$helpers" >>${mid_file}
    echo >>${mid_file}

    cat <<EOF >>${mid_file}

#ifndef offsetof
#define offsetof( type, member ) ( (int) ( (char *) ( &( ( (type *) 0 )->member ) ) ) )
#endif

int main( int argc, char **argv )
{
    printf( "/* This file generated by ${mid_file}, generated by offset-tool.sh. Do not edit!*/\n" );
    printf( "/* Scanned from files: $infiles */\n\n" );

    printf( "#ifndef _OFFSET_TOOL_HEADER_FILE\n" );
    printf( "#define _OFFSET_TOOL_HEADER_FILE\n\n" );

EOF

    for ping in $defines ; do
	type=`echo $ping |sed -e 's|--.*$||'`
	member=`echo $ping |sed -e 's|^.*--||'`

	cat <<EOF >>${mid_file}
    printf( "#define BALSA_OFFSET_${type}_ELEM_${member} %d\n", offsetof( $type, $member ) );
EOF
    done

    cat <<EOF >>${mid_file}

    printf( "\n\n#endif\n" );
    return 0;
}
EOF

    mid_exe=`echo ${mid_file} |sed -e 's,\.c,,'`
    if test x`echo ${mid_exe} |grep '^/'` = x ; then
	mid_exe="./${mid_exe}"
    fi

    echo "Building ${mid_exe} ..."
    ${SHELL} libtool --mode=link ${CC} -o ${mid_exe} ${DEFS} ${CFLAGS} ${mid_file} || {
	echo "Error compiling ${mid_file}"
	exit 2
    }

    echo "Running ${mid_exe} >${header}"
    ${mid_exe} >${header} || {
	echo "Error running ${mid_exe} made from ${mid_file}"
	exit 3
    }

    if test x"$no_clean" = xyes ; then
	:
    else
	echo "Cleaning up..."
	rm -f ${mid_file} ${mid_exe}
    fi

    res=$?
    echo "Done creating ${header}"
    exit $res
fi

if test x"$mode" = xmakerules ; then
    # FIXME bleah
    tab=`echo -e '\t'`
    
    cat <<EOF
${header}: \$(top_builddir)/${offset_tool_home}/offset-tool.sh ${infiles}
${tab}\$(SHELL) \$(top_builddir)/${offset_tool_home}/offset-tool.sh --create ${infiles}

${fragname}: \$(top_builddir)/${offset_tool_home}/offset-tool.sh
${tab}\$(SHELL) \$(top_builddir)/${offset_tool_home}/offset-tool.sh --makerules --fragname ${fragname} ${infiles} >${fragname}

\$(top_builddir)/${offset_tool_home}/offset-tool.sh: \$(top_builddir)/config.status \$(top_srcdir)/${offset_tool_home}/offset-tool.sh.in
${tab}(cd \$(top_builddir) && CONFIG_FILES="${offset_tool_home}/offset-tool.sh" CONFIG_HEADERS= \$(SHELL) ./config.status)
${tab}chmod +x \$(top_builddir)/${offset_tool_home}/offset-tool.sh

offset-clean:
${tab}rm -f ${header}

offset-realclean:
${tab}rm -f \$(top_builddir)/${offset_tool_home}/offset-tool.sh ${fragname}
EOF
    exit 0
fi

if x"$mode" = xheadername; then
    echo ${header}
    exit 0
fi

echo "Unhandled mode: $mode" 1>&2
exit 1