#

# Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).

# All rights reserved.

# This component and the accompanying materials are made available

# under the terms of the License "Eclipse Public License v1.0"

# which accompanies this distribution, and is available

# at the URL "http://www.eclipse.org/legal/epl-v10.html".

#

# Initial Contributors:

# Nokia Corporation - initial contribution.

#

# Contributors:

#

# Description: 

# Minimise the dependencies in a C preprocessor dependency file to

# those that CPP could not find.  Then add in an assumption about 

# where to find them.  Output is assumed to be relevant to only one target

# even if multiple dep files are analysed.

#

import sys

from  optparse import OptionParser

import re

class NoTargetException(Exception):

	pass

def depcrunch(file,extensions,assume):

	target_pattern = r"^\s*(\S+):\s+"

	target_re = re.compile(target_pattern)

	# Not the use of (?i) in the following expression.  re.I seems to cause re.findall

	# to not actually find all files matching the extension whereas (?i) provides

	# case insensitivity at the right point and it works.  Really don't understand this.

	extension_pattern = r"\s([^/ \t]+\.((?i)" + "|".join([t for t in extensions]) + r"))\b"

	extension_re = re.compile(extension_pattern)

	target = None

	deps = []

	# Read through the dependencies.

	for l in file:

		l = l.replace("\\","/").rstrip("\n\r")

		# Look out for the target name if 

		# we have not found it yet

		if not target:

			t = target_re.match(l)

			if t:

				target = t.groups()[0]

		# Look for prerequisites matching the 

		# extensions.  There may be one or more on 

		# the same line as the target name.

		# Don't use re.I - somehow prevents 

		# all but one match in a line which may have several files

		m = extension_re.findall(l)

		if m:

			deps.extend([d[0] for d in m])

	if not target:

		raise NoTargetException()

	if len(deps) > 0:

		print "%s: \\" % target

		for d in deps[:-1]:

			print " %s \\" % (assume + "/" + d)

		print " %s " % (assume + "/" + deps[-1])

## Command Line Interface ####################################################

parser = OptionParser(prog = "depcrunch",

	usage = "%prog [-h | options] [<depfile>]")

parser.add_option("-e", "--extensions", 

	 action="store", dest="extensions", type='string', help="comma separated list of file extensions of missing files to keep in the crunched dep file.") 

parser.add_option("-a", "--assume", 

	 action="store", dest="assume", type='string', help="when cpp reports missing dependencies, assume that they are in this directory") 

(options, args) = parser.parse_args()

if not options.extensions:

	parser.error("you must specify a comma-separated list of file extensions with the -e option.")

	sys.exit(1)

if not options.assume:

	parser.error("you must specify an 'assumed directory' for correcting missing dependencies with the -a option.")

	sys.exit(1)

depfilename="stdin"

if len(args) > 0:

	depfilename=args[0]

	file = open(depfilename,"r")

else:

	file = sys.stdin

try:

	depcrunch(file,options.extensions.split(","), options.assume)

except NoTargetException,e:

	sys.stderr.write("Target name not found in dependency file\n");

	sys.exit(2)

if file != sys.stdin:

	file.close()

sys.exit(0)