#! /bin/sh

#

# Copyright 2000-2001 Sun Microsystems, Inc.  All Rights Reserved.

# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

#

# This code is free software; you can redistribute it and/or modify it

# under the terms of the GNU General Public License version 2 only, as

# published by the Free Software Foundation.  Sun designates this

# particular file as subject to the "Classpath" exception as provided

# by Sun in the LICENSE file that accompanied this code.

#

# This code 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

# version 2 for more details (a copy is included in the LICENSE file that

# accompanied this code).

#

# You should have received a copy of the GNU General Public License version

# 2 along with this work; if not, write to the Free Software Foundation,

# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

#

# Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

# CA 95054 USA or visit www.sun.com if you need additional information or

# have any questions.

#

# SPP: A simple/sed-based/stream preprocessor

# Mark Reinhold / mr@sun.com

#

# Usage: spp [-be] [-Kkey] -Dvar=value ... <in >out

#

# Source-file constructs

#

#   Meaningful only at beginning of line, works with any number of keys:

#

#     #if[key]              Includes text between #if/#end if -Kkey specified,

#     #else[key]               otherwise changes text to blank lines; key test

#     #end[key]                may be negated by prefixing !, e.g., #if[!key]

#

#     #begin                If -be is specified then lines up to and including

#     #end                     #begin, and from #end to EOF, are deleted

#

#     #warn                 Changed into warning that file is generated

#

#     // ##                 Changed into blank line

#

#   Meaningful anywhere in line, works only for first two keys:

#

#     {#if[key]?yes}        Expands to yes if -Kkey specified

#     {#if[key]?yes:no}     Expands to yes if -Kkey, otherwise no

#     {#if[!key]?yes}       Expands to yes if -Kother

#     {#if[!key]?yes:no}    Expands to yes if -Kother, otherwise no

#     $var$                 Expands to value if -Dvar=value given

#

#     yes, no must not contain whitespace

#

# If the environment variable SED is defined, uses that instead of sed

# If the environment variable NAWK is defined, uses that instead of awk

#

SED=${SED:-sed}

NAWK=${NAWK:-awk}

# Map a string of the form -Dvar=value into an appropriate sed command

#

subst() {

  # The first two lines are to avoid the direct use of echo,

  # which does not treat backslashes consistently across platforms

  echo '' \

    | $SED -e "s
.*
$*
" \

    | $SED -e 's
-D\([a-zA-Z_][-a-zA-Z_]*\)=\(.*\)'
"s\\\\\$\\1\\\\\$\2g
g" \

           -e 's
-D\([a-zA-Z_][-a-zA-Z_]*\)'
"s\\\\\$\\1\\\\\$1g
g" \

           -e 's/ /
/g'

}

es=

be=

keys=

key1=_1_

key2=_2_

while [ $# -gt 0 ]; do

  case "$1" in

    -be)

      be='-e 1,/^#begin$/d -e /^#end$/,$d'

      ;;

    -D*)

      es="$es -e `subst $1`"

      ;;

    -K*)

      nk=`echo $1 | $SED -e 's/-K//'`

      if [ "x$keys" = x ]; then keys="$nk"; else keys="$keys $nk"; fi

      if [ "x$key1" = x_1_ ]; then key1="$nk";

      elif [ "x$key2" = x_2_ ]; then key2="$nk"; fi

      ;;

    *)

      echo "Usage: $0 [-be] [-Kkey] -Dvar=value ... <in >out"

      exit 1

      ;;

  esac

  shift

done

text='[-a-zA-Z0-9&;,.<>/#() ]'

$SED $es \

  -e 's/
/ /g' \

  -e "s@^#warn .*@// -- This file was mechanically generated: Do not edit! -- //@" \

  -e 's-// ##.*$--' $be \

  -e "s/{#if\[$key1\]?\($text*\):\($text*\)}/\1/g" \

  -e "s/{#if\[!$key1\]?\($text*\):\($text*\)}/\2/g" \

  -e "s/{#if\[$key1\]?\($text*\)}/\1/g" \

  -e "s/{#if\[!$key1\]?\($text*\)}//g" \

  -e "s/{#if\[$key2\]?\($text*\):\($text*\)}/\1/g" \

  -e "s/{#if\[!$key2\]?\($text*\):\($text*\)}/\2/g" \

  -e "s/{#if\[$key2\]?\($text*\)}/\1/g" \

  -e "s/{#if\[!$key2\]?\($text*\)}//g" \

  -e "s/{#if\[[a-z]*\]?\($text*\):\($text*\)}/\2/g" \

  -e "s/{#if\[![a-z]*\]?\($text*\):\($text*\)}/\1/g" \

  -e "s/{#if\[[a-z]*\]?\($text*\)}//g" \

  -e "s/{#if\[![a-z]*\]?\($text*\)}/\1/g" \

| $NAWK \

  'function key(s) {

     i = match(s, "[a-zA-Z][a-zA-Z]*\\]");

     if (i > 0) return substr(s, i, RLENGTH - 1);

     return "XYZZY"; }

   function neg(s) { return match(s, "!") > 0; }

   BEGIN {

     KEYS = "'"$keys"'"

     n = split(KEYS, ks, "  *");

     for (i = 1; i <= n; i++) keys[ks[i]] = 1;

     top = 1; copy[top] = 1 }

   /^#if\[!?[a-zA-Z][a-zA-Z]*\]/ \

     { k = key($0);

       n = neg($0);

       stack[++top] = k;

       if ((k in keys) == !n) {

	 copy[top] = copy[top - 1];

       } else {

	 copy[top] = 0;

       }

       print ""; next }

   /^#else\[!?[a-zA-Z][a-zA-Z]*\]/ \

     { k = key($0);

       if (stack[top] == k) {

	 copy[top] = copy[top - 1] && !copy[top];

       } else {

	 printf "%d: Mismatched #else key\n", NR | "cat 1>&2";

	 exit 11

       }

       print ""; next }

   /^#end\[!?[a-zA-Z][a-zA-Z]*\]/ \

     { k = key($0);

       if (stack[top] == k) {

	 top--;

       } else {

	 printf "%d: Mismatched #end key\n", NR | "cat 1>&2"

	 exit 11

       }

       print ""; next }

   /^#/ {

     printf "%d: Malformed #directive\n", NR | "cat 1>&2"

     exit 11

   }

   { if (copy[top]) print; else print "" }'