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#!/usr/bin/python2.4
#
# Copyright 2009, 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.
"""Crocodile source scanners."""
import re
class Scanner(object):
"""Generic source scanner."""
def __init__(self):
"""Constructor."""
self.re_token = re.compile('#')
self.comment_to_eol = ['#']
self.comment_start = None
self.comment_end = None
def ScanLines(self, lines):
"""Scans the lines for executable statements.
Args:
lines: Iterator returning source lines.
Returns:
An array of line numbers which are executable.
"""
exe_lines = []
lineno = 0
in_string = None
in_comment = None
comment_index = None
for line in lines:
lineno += 1
in_string_at_start = in_string
for t in self.re_token.finditer(line):
tokenstr = t.groups()[0]
if in_comment:
# Inside a multi-line comment, so look for end token
if tokenstr == in_comment:
in_comment = None
# Replace comment with spaces
line = (line[:comment_index]
+ ' ' * (t.end(0) - comment_index)
+ line[t.end(0):])
elif in_string:
# Inside a string, so look for end token
if tokenstr == in_string:
in_string = None
elif tokenstr in self.comment_to_eol:
# Single-line comment, so truncate line at start of token
line = line[:t.start(0)]
break
elif tokenstr == self.comment_start:
# Multi-line comment start - end token is comment_end
in_comment = self.comment_end
comment_index = t.start(0)
else:
# Starting a string - end token is same as start
in_string = tokenstr
# If still in comment at end of line, remove comment
if in_comment:
line = line[:comment_index]
# Next line, delete from the beginnine
comment_index = 0
# If line-sans-comments is not empty, claim it may be executable
if line.strip() or in_string_at_start:
exe_lines.append(lineno)
# Return executable lines
return exe_lines
def Scan(self, filename):
"""Reads the file and scans its lines.
Args:
filename: Path to file to scan.
Returns:
An array of line numbers which are executable.
"""
# TODO: All manner of error checking
f = None
try:
f = open(filename, 'rt')
return self.ScanLines(f)
finally:
if f:
f.close()
class PythonScanner(Scanner):
"""Python source scanner."""
def __init__(self):
"""Constructor."""
Scanner.__init__(self)
# TODO: This breaks for strings ending in more than 2 backslashes. Need
# a pattern which counts only an odd number of backslashes, so the last
# one thus escapes the quote.
self.re_token = re.compile(r'(#|\'\'\'|"""|(?<!(?<!\\)\\)["\'])')
self.comment_to_eol = ['#']
self.comment_start = None
self.comment_end = None
class CppScanner(Scanner):
"""C / C++ / ObjC / ObjC++ source scanner."""
def __init__(self):
"""Constructor."""
Scanner.__init__(self)
# TODO: This breaks for strings ending in more than 2 backslashes. Need
# a pattern which counts only an odd number of backslashes, so the last
# one thus escapes the quote.
self.re_token = re.compile(r'(^\s*#|//|/\*|\*/|(?<!(?<!\\)\\)["\'])')
# TODO: Treat '\' at EOL as a token, and handle it as continuing the
# previous line. That is, if in a comment-to-eol, this line is a comment
# too.
# Note that we treat # at beginning of line as a comment, so that we ignore
# preprocessor definitions
self.comment_to_eol = ['//', '#']
self.comment_start = '/*'
self.comment_end = '*/'
def ScanFile(filename, language):
"""Scans a file for executable lines.
Args:
filename: Path to file to scan.
language: Language for file ('C', 'C++', 'python', 'ObjC', 'ObjC++')
Returns:
A list of executable lines, or an empty list if the file was not a handled
language.
"""
if language == 'python':
return PythonScanner().Scan(filename)
elif language in ['C', 'C++', 'ObjC', 'ObjC++']:
return CppScanner().Scan(filename)
# Something we don't handle
return []
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