#!/bin/bash
#
# Copyright 2009 Joe Perches <joe@perches.com>
# Copyright 2010 Luis R. Rodriguez <lrodriguez@atheros.com>
#
# Permission to use, copy, modify, and/or distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

# Lets you remove typedefs, or standard data type redefinitions
# from C/header files.
#
# We do simple sed substituation for logical places where you would
# use the typedef, and also replace the typedef declaration to a simple
# struct declaration.

function usage()
{
	echo "Usage $0 [-s] <typedef-name> <struct-name> <paths>"
	exit 1
}

function remove_typedef()
{
	if [ ! -f $1 ]; then
		return;
	fi

	# This replaces the typedef usages with simple structs
	sed -r -i -e "s/\b$from\b/struct $to/g" $1
	sed -r -i -e "s/\bP$from\b/struct $to \*/g" $1
	sed -r -i -e "s/struct $to\s*\*\s*\b/struct $to \*/g" $1
	sed -r -i -e "s/\(struct $to\s*\*\)\s*/\(struct $to \*\)/g" $1

	# This replaces the typedef declaration for a simple struct declaration - style 0
	perl -i -e "local $/; while(<>) { s/\btypedef\s+struct\s+([\d\D]+?)\s*\{([\d\D]+?)\}\s*struct\s+$to\b[^;]*;/struct $to \{\2\};/g; print; }" $1

	# This replaces the typedef declaration for a simple struct declaration - style 1
	perl -i -e "local $/; while(<>) { s/\btypedef\s+struct\s+_$from\s*\{([\d\D]+?)\}\s*struct\s+$to\b[^;]*;/struct $to \{\1\};/g; print; }" $1

	# This replaces the typedef declaration for a simple struct declaration - style 2
	perl -i -e "local $/; while(<>) { s/\btypedef\s+struct\s+$to\s*\{([\d\D]+?)\}\s*$from\b[^;]*;/struct $to \{\1\};/g; print; }" $1

}

function convert_standard_datatype()
{
	sed -r -i -e "s/\b$from\b/$to/g" $1
}

if [[ $# -lt 3 ]]; then
	usage
fi

STD=""
if [[ $1 -eq "-s" ]]; then
	STD="y"
	shift
fi

from=$1
to=$2
shift

echo "Converting typedef $from to struct $to"

while shift; do
	REM_PATH=$1

	if [ -z $REM_PATH ]; then
		continue;
	fi

	if [ ! -d $REM_PATH ]; then
		echo "No directory $REM_PATH";
		continue;
	fi

	for i in $(find $REM_PATH -type f -name \*.[ch]); do
		if [[ $STD -eq "y" ]]; then
			convert_standard_datatype $i
		else
			remove_typedef $i
		fi
	done
done