13
0
livetrax/tools/cstyle.py

248 lines
8.3 KiB
Python
Executable File

#!/usr/bin/python -tt
#
# Copyright (C) 2005-2012 Erik de Castro Lopo <erikd@mega-nerd.com>
#
# Released under the 2 clause BSD license.
"""
This program checks C code for compliance to coding standards used in
libsndfile and other projects I run.
"""
import re
import sys
class Preprocessor:
"""
Preprocess lines of C code to make it easier for the CStyleChecker class to
test for correctness. Preprocessing works on a single line at a time but
maintains state between consecutive lines so it can preprocessess multi-line
comments.
Preprocessing involves:
- Strip C++ style comments from a line.
- Strip C comments from a series of lines. When a C comment starts and
ends on the same line it will be replaced with 'comment'.
- Replace arbitrary C strings with the zero length string.
- Replace '#define f(x)' with '#define f (c)' (The C #define requires that
there be no space between defined macro name and the open paren of the
argument list).
Used by the CStyleChecker class.
"""
def __init__ (self):
self.comment_nest = 0
self.leading_space_re = re.compile ('^(\t+| )')
self.trailing_space_re = re.compile ('(\t+| )$')
self.define_hack_re = re.compile ("(#\s*define\s+[a-zA-Z0-9_]+)\(")
def comment_nesting (self):
"""
Return the currect comment nesting. At the start and end of the file,
this value should be zero. Inside C comments it should be 1 or
(possibly) more.
"""
return self.comment_nest
def __call__ (self, line):
"""
Strip the provided line of C and C++ comments. Stripping of multi-line
C comments works as expected.
"""
line = self.define_hack_re.sub (r'\1 (', line)
line = self.process_strings (line)
# Strip C++ style comments.
if self.comment_nest == 0:
line = re.sub ("( |\t*)//.*", '', line)
# Strip C style comments.
open_comment = line.find ('/*')
close_comment = line.find ('*/')
if self.comment_nest > 0 and close_comment < 0:
# Inside a comment block that does not close on this line.
return ""
if open_comment >= 0 and close_comment < 0:
# A comment begins on this line but doesn't close on this line.
self.comment_nest += 1
return self.trailing_space_re.sub ('', line [:open_comment])
if open_comment < 0 and close_comment >= 0:
# Currently open comment ends on this line.
self.comment_nest -= 1
return self.trailing_space_re.sub ('', line [close_comment + 2:])
if open_comment >= 0 and close_comment > 0 and self.comment_nest == 0:
# Comment begins and ends on this line. Replace it with 'comment'
# so we don't need to check whitespace before and after the comment
# we're removing.
newline = line [:open_comment] + "comment" + line [close_comment + 2:]
return self.__call__ (newline)
return line
def process_strings (self, line):
"""
Given a line of C code, return a string where all literal C strings have
been replaced with the empty string literal "".
"""
for k in range (0, len (line)):
if line [k] == '"':
start = k
for k in range (start + 1, len (line)):
if line [k] == '"' and line [k - 1] != '\\':
return line [:start + 1] + '"' + self.process_strings (line [k + 1:])
return line
class CStyleChecker:
"""
A class for checking the whitespace and layout of a C code.
"""
def __init__ (self, debug):
self.debug = debug
self.filename = None
self.error_count = 0
self.line_num = 1
self.orig_line = ''
self.trailing_newline_re = re.compile ('[\r\n]+$')
self.indent_re = re.compile ("^\s*")
self.last_line_indent = ""
self.last_line_indent_curly = False
self.re_checks = \
[ ( re.compile ("^ "), "leading space as indentation instead of tab - use tabs to indent, spaces to align" )
, ( re.compile ("{[^\s]"), "missing space after open brace" )
, ( re.compile ("[^\s]}"), "missing space before close brace" )
, ( re.compile ("^[ \t]+$"), "empty line contains whitespace" )
, ( re.compile ("[^\s][ \t]+$"), "contains trailing whitespace" )
, ( re.compile (",[^\s\n]"), "missing space after comma" )
, ( re.compile (";[a-zA-Z0-9]"), "missing space after semi-colon" )
, ( re.compile ("=[^\s\"'=]"), "missing space after assignment" )
# Open and close parenthesis.
, ( re.compile ("[^_\s\(\[\*&']\("), "missing space before open parenthesis" )
, ( re.compile ("\)(-[^>]|[^;,'\s\n\)\]-])"), "missing space after close parenthesis" )
, ( re.compile ("\( [^;]"), "space after open parenthesis" )
, ( re.compile ("[^;] \)"), "space before close parenthesis" )
# Open and close square brace.
, ( re.compile ("\[ "), "space after open square brace" )
, ( re.compile (" \]"), "space before close square brace" )
# Space around operators.
, ( re.compile ("[^\s][\*/%+-][=][^\s]"), "missing space around opassign" )
, ( re.compile ("[^\s][<>!=^/][=]{1,2}[^\s]"), "missing space around comparison" )
# Parens around single argument to return.
, ( re.compile ("\s+return\s+\([a-zA-Z0-9_]+\)\s+;"), "parens around return value" )
]
def get_error_count (self):
"""
Return the current error count for this CStyleChecker object.
"""
return self.error_count
def check_files (self, files):
"""
Run the style checker on all the specified files.
"""
for filename in files:
self.check_file (filename)
def check_file (self, filename):
"""
Run the style checker on the specified file.
"""
self.filename = filename
try:
cfile = open (filename, "r")
except IOError as e:
return
self.line_num = 1
preprocess = Preprocessor ()
while 1:
line = cfile.readline ()
if not line:
break
line = self.trailing_newline_re.sub ('', line)
self.orig_line = line
self.line_checks (preprocess (line))
self.line_num += 1
cfile.close ()
self.filename = None
# Check for errors finding comments.
if preprocess.comment_nesting () != 0:
print ("Weird, comments nested incorrectly.")
sys.exit (1)
return
def line_checks (self, line):
"""
Run the style checker on provided line of text, but within the context
of how the line fits within the file.
"""
indent = len (self.indent_re.search (line).group ())
if re.search ("^\s+}", line):
if not self.last_line_indent_curly and indent != self.last_line_indent:
None # self.error ("bad indent on close curly brace")
self.last_line_indent_curly = True
else:
self.last_line_indent_curly = False
# Now all the regex checks.
for (check_re, msg) in self.re_checks:
if check_re.search (line):
self.error (msg)
if re.search ("[a-zA-Z0-9_][<>!=^/&\|]{1,2}[a-zA-Z0-9_]", line):
# ignore #include <foo.h> and C++ templates with indirection/pointer/reference operators
if not re.search (".*#include.*[a-zA-Z0-9]/[a-zA-Z]", line) and not re.search ("[a-zA-Z0-9_]>[&\*]*\s", line):
self.error ("missing space around operator")
self.last_line_indent = indent
return
def error (self, msg):
"""
Print an error message and increment the error count.
"""
print ("%s (%d) : %s" % (self.filename, self.line_num, msg))
if self.debug:
print ("'" + self.orig_line + "'")
self.error_count += 1
#-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
if len (sys.argv) < 1:
print ("Usage : yada yada")
sys.exit (1)
# Create a new CStyleChecker object
if sys.argv [1] == '-d' or sys.argv [1] == '--debug':
cstyle = CStyleChecker (True)
cstyle.check_files (sys.argv [2:])
else:
cstyle = CStyleChecker (False)
cstyle.check_files (sys.argv [1:])
if cstyle.get_error_count ():
sys.exit (1)
sys.exit (0)