move string literal checker from format.py to strings.py

4 files changed, 110 insertions, 107 deletions

diff --git a/checkers/__init__.py b/checkers/__init__.py
index 299078a..700a78e 100644
--- a/checkers/__init__.py
+++ b/checkers/__init__.py
@@ -30,7 +30,7 @@ Base id of standard checkers (used in msg and report ids):
 12: logging
 13: string_format
 14: string_constant
-14-50: not yet used: reserved for future internal checkers.
+15-50: not yet used: reserved for future internal checkers.
 51-99: perhaps used: reserved for external checkers
 
 The raw_metrics checker has no number associated since it doesn't emit any
diff --git a/checkers/format.py b/checkers/format.py
index 82d55fe..6ae8706 100644
--- a/checkers/format.py
+++ b/checkers/format.py
@@ -1,6 +1,4 @@
-# Copyright (c) 2003-2010 Sylvain Thenault (thenault@gmail.com).
-# Copyright (c) 2003-2012 LOGILAB S.A. (Paris, FRANCE).
-# Copyright 2012 Google Inc.
+# Copyright (c) 2003-2013 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
@@ -128,7 +126,6 @@ BAD_CONSTRUCT_RGXS = (
      'C0324'),
     )
 
-_PY3K = sys.version_info >= (3, 0)
 
 def get_string_coords(line):
     """return a list of string positions (tuple (start, end)) in the line
@@ -371,106 +368,6 @@ class FormatChecker(BaseRawChecker):
                                    expected * unit_size))
 
 
-class StringConstantChecker(BaseRawChecker):
-    """Check string literals"""
-
-    msgs = {
-        'W1401': ('Anomalous backslash in string: \'%s\'. '
-                  'String constant might be missing an r prefix.',
-                  'anomalous-backslash-in-string',
-                  'Used when a backslash is in a literal string but not as an '
-                  'escape.'),
-        'W1402': ('Anomalous Unicode escape in byte string: \'%s\'. '
-                  'String constant might be missing an r or u prefix.',
-                  'anomalous-unicode-escape-in-string',
-                  'Used when an escape like \\u is encountered in a byte '
-                  'string where it has no effect.'),
-        }
-    name = 'string_constant'
-    __implements__ = (IRawChecker, IASTNGChecker)
-
-    # Characters that have a special meaning after a backslash in either
-    # Unicode or byte strings.
-    ESCAPE_CHARACTERS = 'abfnrtvx\n\r\t\\\'\"01234567'
-
-    # TODO(mbp): Octal characters are quite an edge case today; people may
-    # prefer a separate warning where they occur.  \0 should be allowed.
-
-    # Characters that have a special meaning after a backslash but only in
-    # Unicode strings.
-    UNICODE_ESCAPE_CHARACTERS = 'uUN'
-
-    def process_tokens(self, tokens):
-        for (tok_type, token, (start_row, start_col), _, _) in tokens:
-            if tok_type == tokenize.STRING:
-                # 'token' is the whole un-parsed token; we can look at the start
-                # of it to see whether it's a raw or unicode string etc.
-                self.process_string_token(token, start_row, start_col)
-
-    def process_string_token(self, token, start_row, start_col):
-        for i, c in enumerate(token):
-            if c in '\'\"':
-                quote_char = c
-                break
-        prefix = token[:i].lower()  #  markers like u, b, r.
-        after_prefix = token[i:]
-        if after_prefix[:3] == after_prefix[-3:] == 3 * quote_char:
-            string_body = after_prefix[3:-3]
-        else:
-            string_body = after_prefix[1:-1]  # Chop off quotes
-        # No special checks on raw strings at the moment.
-        if 'r' not in prefix:
-            self.process_non_raw_string_token(prefix, string_body,
-                start_row, start_col)
-
-    def process_non_raw_string_token(self, prefix, string_body, start_row,
-                                     start_col):
-        """check for bad escapes in a non-raw string.
-
-        prefix: lowercase string of eg 'ur' string prefix markers.
-        string_body: the un-parsed body of the string, not including the quote
-        marks.
-        start_row: integer line number in the source.
-        start_col: integer column number in the source.
-        """
-        # Walk through the string; if we see a backslash then escape the next
-        # character, and skip over it.  If we see a non-escaped character,
-        # alert, and continue.
-        #
-        # Accept a backslash when it escapes a backslash, or a quote, or
-        # end-of-line, or one of the letters that introduce a special escape
-        # sequence <http://docs.python.org/reference/lexical_analysis.html>
-        #
-        # TODO(mbp): Maybe give a separate warning about the rarely-used
-        # \a \b \v \f?
-        #
-        # TODO(mbp): We could give the column of the problem character, but
-        # add_message doesn't seem to have a way to pass it through at present.
-        i = 0
-        while True:
-            i = string_body.find('\\', i)
-            if i == -1:
-                break
-            # There must be a next character; having a backslash at the end
-            # of the string would be a SyntaxError.
-            next_char = string_body[i+1]
-            match = string_body[i:i+2]
-            if next_char in self.UNICODE_ESCAPE_CHARACTERS:
-                if 'u' in prefix:
-                    pass
-                elif _PY3K and 'b' not in prefix:
-                    pass  # unicode by default
-                else:
-                    self.add_message('W1402', line=start_row, args=(match, ))
-            elif next_char not in self.ESCAPE_CHARACTERS:
-                self.add_message('W1401', line=start_row, args=(match, ))
-            # Whether it was a valid escape or not, backslash followed by
-            # another character can always be consumed whole: the second
-            # character can never be the start of a new backslash escape.
-            i += 2
-
-
 def register(linter):
     """required method to auto register this checker """
     linter.register_checker(FormatChecker(linter))
-    linter.register_checker(StringConstantChecker(linter))
diff --git a/checkers/strings.py b/checkers/strings.py
index 9786090..5c7d1e7 100644
--- a/checkers/strings.py
+++ b/checkers/strings.py
@@ -18,12 +18,16 @@
 """Checker for string formatting operations.
 """
 
+import sys
+import tokenize
+
 from logilab import astng
 
-from pylint.interfaces import IASTNGChecker
-from pylint.checkers import BaseChecker
+from pylint.interfaces import IRawChecker, IASTNGChecker
+from pylint.checkers import BaseChecker, BaseRawChecker
 from pylint.checkers import utils
 
+_PY3K = sys.version_info >= (3, 0)
 
 MSGS = {
     'E1300': ("Unsupported format character %r (%#02x) at index %d",
@@ -186,8 +190,107 @@ class StringMethodsChecker(BaseChecker):
                                  args=(func.bound.name, func.name))
 
 
+class StringConstantChecker(BaseRawChecker):
+    """Check string literals"""
+    __implements__ = (IRawChecker, IASTNGChecker)
+    name = 'string_constant'
+    msgs = {
+        'W1401': ('Anomalous backslash in string: \'%s\'. '
+                  'String constant might be missing an r prefix.',
+                  'anomalous-backslash-in-string',
+                  'Used when a backslash is in a literal string but not as an '
+                  'escape.'),
+        'W1402': ('Anomalous Unicode escape in byte string: \'%s\'. '
+                  'String constant might be missing an r or u prefix.',
+                  'anomalous-unicode-escape-in-string',
+                  'Used when an escape like \\u is encountered in a byte '
+                  'string where it has no effect.'),
+        }
+
+    # Characters that have a special meaning after a backslash in either
+    # Unicode or byte strings.
+    ESCAPE_CHARACTERS = 'abfnrtvx\n\r\t\\\'\"01234567'
+
+    # TODO(mbp): Octal characters are quite an edge case today; people may
+    # prefer a separate warning where they occur.  \0 should be allowed.
+
+    # Characters that have a special meaning after a backslash but only in
+    # Unicode strings.
+    UNICODE_ESCAPE_CHARACTERS = 'uUN'
+
+    def process_tokens(self, tokens):
+        for (tok_type, token, (start_row, start_col), _, _) in tokens:
+            if tok_type == tokenize.STRING:
+                # 'token' is the whole un-parsed token; we can look at the start
+                # of it to see whether it's a raw or unicode string etc.
+                self.process_string_token(token, start_row, start_col)
+
+    def process_string_token(self, token, start_row, start_col):
+        for i, c in enumerate(token):
+            if c in '\'\"':
+                quote_char = c
+                break
+        prefix = token[:i].lower()  #  markers like u, b, r.
+        after_prefix = token[i:]
+        if after_prefix[:3] == after_prefix[-3:] == 3 * quote_char:
+            string_body = after_prefix[3:-3]
+        else:
+            string_body = after_prefix[1:-1]  # Chop off quotes
+        # No special checks on raw strings at the moment.
+        if 'r' not in prefix:
+            self.process_non_raw_string_token(prefix, string_body,
+                start_row, start_col)
+
+    def process_non_raw_string_token(self, prefix, string_body, start_row,
+                                     start_col):
+        """check for bad escapes in a non-raw string.
+
+        prefix: lowercase string of eg 'ur' string prefix markers.
+        string_body: the un-parsed body of the string, not including the quote
+        marks.
+        start_row: integer line number in the source.
+        start_col: integer column number in the source.
+        """
+        # Walk through the string; if we see a backslash then escape the next
+        # character, and skip over it.  If we see a non-escaped character,
+        # alert, and continue.
+        #
+        # Accept a backslash when it escapes a backslash, or a quote, or
+        # end-of-line, or one of the letters that introduce a special escape
+        # sequence <http://docs.python.org/reference/lexical_analysis.html>
+        #
+        # TODO(mbp): Maybe give a separate warning about the rarely-used
+        # \a \b \v \f?
+        #
+        # TODO(mbp): We could give the column of the problem character, but
+        # add_message doesn't seem to have a way to pass it through at present.
+        i = 0
+        while True:
+            i = string_body.find('\\', i)
+            if i == -1:
+                break
+            # There must be a next character; having a backslash at the end
+            # of the string would be a SyntaxError.
+            next_char = string_body[i+1]
+            match = string_body[i:i+2]
+            if next_char in self.UNICODE_ESCAPE_CHARACTERS:
+                if 'u' in prefix:
+                    pass
+                elif _PY3K and 'b' not in prefix:
+                    pass  # unicode by default
+                else:
+                    self.add_message('W1402', line=start_row, args=(match, ))
+            elif next_char not in self.ESCAPE_CHARACTERS:
+                self.add_message('W1401', line=start_row, args=(match, ))
+            # Whether it was a valid escape or not, backslash followed by
+            # another character can always be consumed whole: the second
+            # character can never be the start of a new backslash escape.
+            i += 2
+
+
 
 def register(linter):
     """required method to auto register this checker """
     linter.register_checker(StringFormatChecker(linter))
     linter.register_checker(StringMethodsChecker(linter))
+    linter.register_checker(StringConstantChecker(linter))
diff --git a/checkers/utils.py b/checkers/utils.py
index aa4563e..da09e86 100644
--- a/checkers/utils.py
+++ b/checkers/utils.py
@@ -20,9 +20,11 @@
 
 import re
 import string
+
 from logilab import astng
 from logilab.astng import scoped_nodes
 from logilab.common.compat import builtins
+
 BUILTINS_NAME = builtins.__name__
 
 COMP_NODE_TYPES = astng.ListComp, astng.SetComp, astng.DictComp, astng.GenExpr
@@ -365,6 +367,7 @@ def is_super_call(expr):
     return (isinstance(expr, astng.CallFunc) and
         isinstance(expr.func, astng.Name) and
         expr.func.name == 'super')
+
 def is_attr_private(attrname):
     """Check that attribute name is private (at least two leading underscores,
     at most one trailing underscore)