#!/bin/sh

PROGNAME="$0"

usage() {
	cat <<EOF
NAME
    `basename $PROGNAME` - CPP replacement

SYNOPSIS
    `basename $PROGNAME` [options] file

DESCRIPTION
    CPP replacement.

    Handles:
	#include "file"
	#ifdef symbol
	#ifndef symbol
	#endif

OPTIONS
    -v DEFn=symbol	Symbol is defined, n = 1, ... 9.
			i.e. -v DEF1=groff is equivalent to:
			#define groff 1
    -D lvl		Debug level
EOF

	exit 1
}

#
#       Report an error and exit
#
error() {
	echo "`basename $PROGNAME`: $1" >&2
	exit 1
}

debug() {
	if [ $DEBUG -ge $1 ]; then
	    echo "`basename $PROGNAME`: $2" >&2
	fi
}

#
#       Process the options
#
DEBUG=0
VARS=""
while getopts "v:D:h?" opt
do
	case $opt in
	v)	VARS="$VARS -v $OPTARG";;
	D)	DEBUG="$OPTARG";;
	h|\?)	usage;;
	esac
done
shift `expr $OPTIND - 1`

#
#	Main Program
#
if [ -x /opt/sfw/bin/gawk ]; then
    AWK=/opt/sfw/bin/gawk
else
    AWK=awk
fi

$AWK $VARS '
function do1(file,	i) {
    if (nfiles++ == 0)
    {
	print comment " t"
	print comment
	print comment "	DO NOT EDIT! This file is generated from " file
	print comment
    }
    while ((getline < file) > 0)
    {
	split($0, a)
	if (a[1] == "#include")
	{
	    gsub(/"/, "", a[2])
	    print comment
	    do1(a[2])
	}
	else if (a[1] == "#define")
	{
	    def[a[2]] = 1
	    print comment
	}
	else if (a[1] == "#ifdef")
	{
	    if (!def[a[2]])
		skip = 1
	    print comment 
	}
	else if (a[1] == "#ifndef")
	{
	    if (def[a[2]])
		skip = 1
	    print comment 
	}
	else if (a[1] == "#endif")
	{
	    skip = 0
	    print comment 
	}
	else if (skip)
	    print comment 
	else
	    print $0
    }
}
BEGIN {
    comment = "'"'"'\\\""
    if (DEF1) def[DEF1] = 1;
    if (DEF2) def[DEF2] = 1;
    if (DEF3) def[DEF3] = 1;
    if (DEF4) def[DEF4] = 1;
    if (DEF5) def[DEF5] = 1;
    if (DEF6) def[DEF6] = 1;
    if (DEF7) def[DEF7] = 1;
    if (DEF8) def[DEF8] = 1;
    if (DEF9) def[DEF9] = 1;
    #for (i in def)
	#print i, def[i]
    do1(ARGV[1])
    exit
}' $*