Add pylint to depot_tools.

third_party/pylint/checkers/format.py

Index: third_party/pylint/checkers/format.py
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+# Copyright (c) 2003-2010 Sylvain Thenault (thenault@gmail.com).
+# Copyright (c) 2003-2010 LOGILAB S.A. (Paris, FRANCE).
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free Software
+# Foundation; either version 2 of the License, or (at your option) any later
+# version.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with
+# this program; if not, write to the Free Software Foundation, Inc.,
+# 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+"""Python code format's checker.
+
+By default try to follow Guido's style guide :
+
+http://www.python.org/doc/essays/styleguide.html
+
+Some parts of the process_token method is based from The Tab Nanny std module.
+"""
+
+import re, sys
+import tokenize
+if not hasattr(tokenize, 'NL'):
+    raise ValueError("tokenize.NL doesn't exist -- tokenize module too old")
+
+from logilab.common.textutils import pretty_match
+from logilab.astng import nodes
+
+from pylint.interfaces import IRawChecker, IASTNGChecker
+from pylint.checkers import BaseRawChecker
+from pylint.checkers.utils import check_messages
+
+MSGS = {
+    'C0301': ('Line too long (%s/%s)',
+              'Used when a line is longer than a given number of characters.'),
+    'C0302': ('Too many lines in module (%s)', # was W0302
+              'Used when a module has too much lines, reducing its readability.'
+              ),
+
+    'W0311': ('Bad indentation. Found %s %s, expected %s',
+              'Used when an unexpected number of indentation\'s tabulations or '
+              'spaces has been found.'),
+    'W0312': ('Found indentation with %ss instead of %ss',
+              'Used when there are some mixed tabs and spaces in a module.'),
+    'W0301': ('Unnecessary semicolon', # was W0106
+              'Used when a statement is ended by a semi-colon (";"), which \
+              isn\'t necessary (that\'s python, not C ;).'),
+    'C0321': ('More than one statement on a single line',
+              'Used when more than on statement are found on the same line.'),
+    'C0322': ('Operator not preceded by a space\n%s',
+              'Used when one of the following operator (!= | <= | == | >= | < '
+              '| > | = | \+= | -= | \*= | /= | %) is not preceded by a space.'),
+    'C0323': ('Operator not followed by a space\n%s',
+              'Used when one of the following operator (!= | <= | == | >= | < '
+              '| > | = | \+= | -= | \*= | /= | %) is not followed by a space.'),
+    'C0324': ('Comma not followed by a space\n%s',
+              'Used when a comma (",") is not followed by a space.'),
+    }
+
+if sys.version_info < (3, 0):
+
+    MSGS.update({
+    'W0331': ('Use of the <> operator',
+              'Used when the deprecated "<>" operator is used instead \
+              of "!=".'),
+    'W0332': ('Use l as long integer identifier',
+              'Used when a lower case "l" is used to mark a long integer. You '
+              'should use a upper case "L" since the letter "l" looks too much '
+              'like the digit "1"'),
+    'W0333': ('Use of the `` operator',
+              'Used when the deprecated "``" (backtick) operator is used '
+              'instead  of the str() function.'),
+    })
+
+# simple quoted string rgx
+SQSTRING_RGX = r'"([^"\\]|\\.)*?"'
+# simple apostrophed rgx
+SASTRING_RGX = r"'([^'\\]|\\.)*?'"
+# triple quoted string rgx
+TQSTRING_RGX = r'"""([^"]|("(?!"")))*?(""")'
+# triple apostrophed string rgx # FIXME english please
+TASTRING_RGX = r"'''([^']|('(?!'')))*?(''')"
+
+# finally, the string regular expression
+STRING_RGX = re.compile('(%s)|(%s)|(%s)|(%s)' % (TQSTRING_RGX, TASTRING_RGX,
+                                                 SQSTRING_RGX, SASTRING_RGX),
+                        re.MULTILINE|re.DOTALL)
+
+COMMENT_RGX = re.compile("#.*$", re.M)
+
+OPERATORS = r'!=|<=|==|>=|<|>|=|\+=|-=|\*=|/=|%'
+
+OP_RGX_MATCH_1 = r'[^(]*(?<!\s|\^|<|>|=|\+|-|\*|/|!|%%|&|\|)(%s).*' % OPERATORS
+OP_RGX_SEARCH_1 = r'(?<!\s|\^|<|>|=|\+|-|\*|/|!|%%|&|\|)(%s)' % OPERATORS
+
+OP_RGX_MATCH_2 = r'[^(]*(%s)(?!\s|=|>|<).*' % OPERATORS
+OP_RGX_SEARCH_2 = r'(%s)(?!\s|=|>)' % OPERATORS
+
+BAD_CONSTRUCT_RGXS = (
+
+    (re.compile(OP_RGX_MATCH_1, re.M),
+     re.compile(OP_RGX_SEARCH_1, re.M),
+     'C0322'),
+
+    (re.compile(OP_RGX_MATCH_2, re.M),
+     re.compile(OP_RGX_SEARCH_2, re.M),
+     'C0323'),
+
+    (re.compile(r'.*,[^(\s|\]|}|\))].*', re.M), 
+     re.compile(r',[^\s)]', re.M),
+     'C0324'),
+    )
+
+
+def get_string_coords(line):
+    """return a list of string positions (tuple (start, end)) in the line
+    """
+    result = []
+    for match in re.finditer(STRING_RGX, line):
+        result.append( (match.start(), match.end()) )
+    return result
+
+def in_coords(match, string_coords):
+    """return true if the match is in the string coord"""
+    mstart = match.start()
+    for start, end in string_coords:
+        if mstart >= start and mstart < end:
+            return True
+    return False
+
+def check_line(line):
+    """check a line for a bad construction
+    if it founds one, return a message describing the problem
+    else return None
+    """
+    cleanstr = COMMENT_RGX.sub('', STRING_RGX.sub('', line))
+    for rgx_match, rgx_search, msg_id in BAD_CONSTRUCT_RGXS:
+        if rgx_match.match(cleanstr):
+            string_positions = get_string_coords(line)
+            for match in re.finditer(rgx_search, line):
+                if not in_coords(match, string_positions):
+                    return msg_id, pretty_match(match, line.rstrip())
+
+
+class FormatChecker(BaseRawChecker):
+    """checks for :
+    * unauthorized constructions
+    * strict indentation
+    * line length
+    * use of <> instead of !=
+    """
+
+    __implements__ = (IRawChecker, IASTNGChecker)
+
+    # configuration section name
+    name = 'format'
+    # messages
+    msgs = MSGS
+    # configuration options
+    # for available dict keys/values see the optik parser 'add_option' method
+    options = (('max-line-length',
+                {'default' : 80, 'type' : "int", 'metavar' : '<int>',
+                 'help' : 'Maximum number of characters on a single line.'}),
+               ('max-module-lines',
+                {'default' : 1000, 'type' : 'int', 'metavar' : '<int>',
+                 'help': 'Maximum number of lines in a module'}
+                ),
+               ('indent-string',
+                {'default' : '    ', 'type' : "string", 'metavar' : '<string>',
+                 'help' : 'String used as indentation unit. This is usually \
+"    " (4 spaces) or "\\t" (1 tab).'}),
+               )
+    def __init__(self, linter=None):
+        BaseRawChecker.__init__(self, linter)
+        self._lines = None
+        self._visited_lines = None
+
+    def process_module(self, node):
+        """extracts encoding from the stream and decodes each line, so that
+        international text's length is properly calculated.
+        """
+        stream = node.file_stream
+        stream.seek(0) # XXX may be removed with astng > 0.23
+        readline = stream.readline
+        if sys.version_info < (3, 0):
+            if node.file_encoding is not None:
+                readline = lambda: stream.readline().decode(node.file_encoding, 'replace')
+        self.process_tokens(tokenize.generate_tokens(readline))
+
+    def new_line(self, tok_type, line, line_num, junk):
+        """a new line has been encountered, process it if necessary"""
+        if not tok_type in junk:
+            self._lines[line_num] = line.split('\n')[0]
+        self.check_lines(line, line_num)
+
+    def process_tokens(self, tokens):
+        """process tokens and search for :
+
+         _ non strict indentation (i.e. not always using the <indent> parameter as
+           indent unit)
+         _ too long lines (i.e. longer than <max_chars>)
+         _ optionally bad construct (if given, bad_construct must be a compiled
+           regular expression).
+        """
+        indent = tokenize.INDENT
+        dedent = tokenize.DEDENT
+        newline = tokenize.NEWLINE
+        junk = (tokenize.COMMENT, tokenize.NL)
+        indents = [0]
+        check_equal = 0
+        line_num = 0
+        previous = None
+        self._lines = {}
+        self._visited_lines = {}
+        for (tok_type, token, start, _, line) in tokens:
+            if start[0] != line_num:
+                if previous is not None and previous[0] == tokenize.OP and previous[1] == ';':
+                    self.add_message('W0301', line=previous[2])
+                previous = None
+                line_num = start[0]
+                self.new_line(tok_type, line, line_num, junk)
+            if tok_type not in (indent, dedent, newline) + junk:
+                previous = tok_type, token, start[0]
+
+            if tok_type == tokenize.OP:
+                if token == '<>':
+                    self.add_message('W0331', line=line_num)
+            elif tok_type == tokenize.NUMBER:
+                if token.endswith('l'):
+                    self.add_message('W0332', line=line_num)
+
+            elif tok_type == newline:
+                # a program statement, or ENDMARKER, will eventually follow,
+                # after some (possibly empty) run of tokens of the form
+                #     (NL | COMMENT)* (INDENT | DEDENT+)?
+                # If an INDENT appears, setting check_equal is wrong, and will
+                # be undone when we see the INDENT.
+                check_equal = 1
+
+            elif tok_type == indent:
+                check_equal = 0
+                self.check_indent_level(token, indents[-1]+1, line_num)
+                indents.append(indents[-1]+1)
+
+            elif tok_type == dedent:
+                # there's nothing we need to check here!  what's important is
+                # that when the run of DEDENTs ends, the indentation of the
+                # program statement (or ENDMARKER) that triggered the run is
+                # equal to what's left at the top of the indents stack
+                check_equal = 1
+                if len(indents) > 1:
+                    del indents[-1]
+
+            elif check_equal and tok_type not in junk:
+                # this is the first "real token" following a NEWLINE, so it
+                # must be the first token of the next program statement, or an
+                # ENDMARKER; the "line" argument exposes the leading whitespace
+                # for this statement; in the case of ENDMARKER, line is an empty
+                # string, so will properly match the empty string with which the
+                # "indents" stack was seeded
+                check_equal = 0
+                self.check_indent_level(line, indents[-1], line_num)
+
+        line_num -= 1 # to be ok with "wc -l"
+        if line_num > self.config.max_module_lines:
+            self.add_message('C0302', args=line_num, line=1)
+
+    @check_messages('C0321' ,'C03232', 'C0323', 'C0324')
+    def visit_default(self, node):
+        """check the node line number and check it if not yet done"""
+        if not node.is_statement:
+            return
+        if not node.root().pure_python:
+            return # XXX block visit of child nodes
+        prev_sibl = node.previous_sibling()
+        if prev_sibl is not None:
+            prev_line = prev_sibl.fromlineno
+        else:
+            prev_line = node.parent.statement().fromlineno
+        line = node.fromlineno
+        assert line, node
+        if prev_line == line and self._visited_lines.get(line) != 2:
+            # py2.5 try: except: finally:
+            if not (isinstance(node, nodes.TryExcept)
+                    and isinstance(node.parent, nodes.TryFinally)
+                    and node.fromlineno == node.parent.fromlineno):
+                self.add_message('C0321', node=node)
+                self._visited_lines[line] = 2
+            return
+        if line in self._visited_lines:
+            return
+        try:
+            tolineno = node.blockstart_tolineno
+        except AttributeError:
+            tolineno = node.tolineno
+        assert tolineno, node
+        lines = []
+        for line in xrange(line, tolineno + 1):
+            self._visited_lines[line] = 1
+            try:
+                lines.append(self._lines[line].rstrip())
+            except KeyError:
+                lines.append('')
+        try:
+            msg_def = check_line('\n'.join(lines))
+            if msg_def:
+                self.add_message(msg_def[0], node=node, args=msg_def[1])
+        except KeyError:
+            # FIXME: internal error !
+            pass
+
+    @check_messages('W0333')
+    def visit_backquote(self, node):
+        self.add_message('W0333', node=node)
+
+    def check_lines(self, lines, i):
+        """check lines have less than a maximum number of characters
+        """
+        max_chars = self.config.max_line_length
+        for line in lines.splitlines():
+            if len(line) > max_chars:
+                self.add_message('C0301', line=i, args=(len(line), max_chars))
+            i += 1
+
+    def check_indent_level(self, string, expected, line_num):
+        """return the indent level of the string
+        """
+        indent = self.config.indent_string
+        if indent == '\\t': # \t is not interpreted in the configuration file
+            indent = '\t'
+        level = 0
+        unit_size = len(indent)
+        while string[:unit_size] == indent:
+            string = string[unit_size:]
+            level += 1
+        suppl = ''
+        while string and string[0] in ' \t':
+            if string[0] != indent[0]:
+                if string[0] == '\t':
+                    args = ('tab', 'space')
+                else:
+                    args = ('space', 'tab')
+                self.add_message('W0312', args=args, line=line_num)
+                return level
+            suppl += string[0]
+            string = string [1:]
+        if level != expected or suppl:
+            i_type = 'spaces'
+            if indent[0] == '\t':
+                i_type = 'tabs'
+            self.add_message('W0311', line=line_num,
+                             args=(level * unit_size + len(suppl), i_type,
+                                   expected * unit_size))
+
+
+def register(linter):
+    """required method to auto register this checker """
+    linter.register_checker(FormatChecker(linter))