#!/bin/sh
# substscr - substitute parameters to create a file from a .in.
#
# Copyright (c) 1999, 2004 Joseph Samuel Myers.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. The name of the author may not be used to endorse or promote products
#    derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.

# First argument is some combination of:
# r to generate makefile rules
# g to generate the file in question

# Second argument gives the style of comment:
# c for C comment
# h for generic # comment
# m for manpage comment
# n for none
# s for shell comment

# Third argument is the source file.

# Fourth argument is the target file.

# The target gets its execute permissions from the source.

set -e

if [ $# != 4 ]; then
    echo "usage: $0 action comment-style source target" >&2
    exit 1
fi

action="$1"
style="$2"
source="$3"
target="$4"

if echo $action |grep -q g; then
    echo "Generating $target from $source"
    rm -f $target

    case "$style" in
	(c)
	    echo "/* Automatically generated from $source.  Do not edit.  */" >"$target"
	    ;;
	(h)
	    echo "# Automatically generated from $source.  Do not edit." >"$target"
	    ;;
	(m)
	    echo ".\\\" Automatically generated from $source.  Do not edit." >"$target"
	    ;;
	(n)
	    : >"$target"
	    ;;
	(s)
	    echo "#!/bin/sh" >"$target"
	    echo "# Automatically generated from $source.  Do not edit." >>"$target"
	    ;;
	(*)
	    echo "$0: unknown comment style $style" >&2
	    exit 1
    esac

    sed -f subst.sed <"$source" >>"$target"

    if [ -x "$source" ]; then
	chmod a+x "$target"
    fi
fi

if echo $action |grep -q r; then
    # Append to subst.rules.
    cat >>subst.rules <<EOF
$target:	$source subst.sed substscr
	./substscr g $style $source $target

EOF
fi