#!/usr/bin/python
# Copyright (C) 2010 Google Inc. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
#     * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#     * 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.
#     * Neither the name of Google Inc. nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "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 COPYRIGHT
# OWNER OR CONTRIBUTORS 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.
#
# This script looks for unnecessary #includes in the given header file,
# or in all header files that can be recursively found in the given directory.

import os
import re
import sys

headerFile = re.compile(r'\.h$')
includeLine = re.compile(r'^#include ("|<wtf/)([A-Z]\w+).h[>"]')
smartPointerString = "(ListRefPtr|OwnArrayPtr|OwnPtr|PassOwnPtr|PassRefPtr|RefPtr)<className>"
allowedIncludes = set(["Forward", "PlatformString", "StringHash", "Threading"])

# Check if 'line' needs any class in 'unnecessaryIncludes' to be included in the header file.
def checkLine(line, unnecessaryIncludes):
    unnecessaryIncludesCopy = unnecessaryIncludes.copy()
    for includedClass in unnecessaryIncludesCopy:
        if re.search(includedClass, line):
            if re.search(includedClass + "\*", line):
                continue

            smartPointerClassString = smartPointerString.replace("className", includedClass)
            if re.search(smartPointerClassString, line):
                continue

            unnecessaryIncludes.remove(includedClass)


# Look for unnecessary includes in the given file
def checkFile(fileName):
    if headerFile.search(fileName):
        f = open(fileName, "r")
        unnecessaryIncludes = set()
        for line in f:
            match = includeLine.match(line)
            if match:
                className = match.group(2)
                if className == "PlatformString":
                    unnecessaryIncludes.add("String")
                elif className not in allowedIncludes:
                    unnecessaryIncludes.add(className)
            else:
                checkLine(line, unnecessaryIncludes)

        if len(unnecessaryIncludes) > 0:
            print fileName
            for includedClass in unnecessaryIncludes:
                print includedClass
            print


# If 'path' is a file, check if it has unnecessary includes.
# If 'path' is a directory, traverse it recursively and look
# for unnecessary includes in all header files.
def checkPath(path):
    if os.path.isfile(path):
        checkFile(path)
    elif os.path.isdir(path):
        dirList = os.listdir(path)
        for dirName in dirList:
            checkPath(path + "/" + dirName)
    else:
        print path, "is not a file or directory."


def main():
    if len(sys.argv) <= 1:
        print "Usage:", sys.argv[0], "<path>"
        return -1

    checkPath(sys.argv[1])


if __name__ == "__main__":
    main()