tools/heapcheck/suppressions.py

   1 #!/usr/bin/env python
   2 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
   3 # Use of this source code is governed by a BSD-style license that can be
   4 # found in the LICENSE file.
   5
   6 """Valgrind-style suppressions for heapchecker reports.
   7
   8 Suppressions are defined as follows:
   9
  10 # optional one-line comments anywhere in the suppressions file.
  11 {
  12   Toolname:Errortype
  13   Short description of the error.
  14   fun:function_name
  15   fun:wildcarded_fun*_name
  16   # an ellipsis wildcards zero or more functions in a stack.
  17   ...
  18   fun:some_other_function_name
  19 }
  20
  21 Note that only a 'fun:' prefix is allowed, i.e. we can't suppress objects and
  22 source files.
  23
  24 If ran from the command line, suppressions.py does a self-test of the
  25 Suppression class.
  26 """
  27
  28 import re
  29
  30 ELLIPSIS = '...'
  31
  32
  33 class Suppression(object):
  34   """This class represents a single stack trace suppression.
  35
  36   Attributes:
  37     type: A string representing the error type, e.g. Heapcheck:Leak.
  38     description: A string representing the error description.
  39   """
  40
  41   def __init__(self, kind, description, stack):
  42     """Inits Suppression.
  43
  44     stack is a list of function names and/or wildcards.
  45
  46     Args:
  47       kind:
  48       description: Same as class attributes.
  49       stack: A list of strings.
  50     """
  51     self.type = kind
  52     self.description = description
  53     self._stack = stack
  54     re_line = ''
  55     re_bucket = ''
  56     for line in stack:
  57       if line == ELLIPSIS:
  58         re_line += re.escape(re_bucket)
  59         re_bucket = ''
  60         re_line += '(.*\n)*'
  61       else:
  62         for char in line:
  63           if char == '*':
  64             re_line += re.escape(re_bucket)
  65             re_bucket = ''
  66             re_line += '.*'
  67           else:  # there can't be any '\*'s in a stack trace
  68             re_bucket += char
  69         re_line += re.escape(re_bucket)
  70         re_bucket = ''
  71         re_line += '\n'
  72     self._re = re.compile(re_line, re.MULTILINE)
  73
  74   def Match(self, report):
  75     """Returns bool indicating whether the suppression matches the given report.
  76
  77     Args:
  78       report: list of strings (function names).
  79     Returns:
  80       True if the suppression is not empty and matches the report.
  81     """
  82     if not self._stack:
  83       return False
  84     if self._re.match('\n'.join(report) + '\n'):
  85       return True
  86     else:
  87       return False
  88
  89
  90 class SuppressionError(Exception):
  91   def __init__(self, filename, line, report=''):
  92     Exception.__init__(self, filename, line, report)
  93     self._file = filename
  94     self._line = line
  95     self._report = report
  96
  97   def __str__(self):
  98     return 'Error reading suppressions from "%s" (line %d): %s.' % (
  99         self._file, self._line, self._report)
 100
 101
 102 def ReadSuppressionsFromFile(filename):
 103   """Given a file, returns a list of suppressions."""
 104   input_file = file(filename, 'r')
 105   result = []
 106   cur_descr = ''
 107   cur_type = ''
 108   cur_stack = []
 109   nline = 0
 110   try:
 111     for line in input_file:
 112       nline += 1
 113       line = line.strip()
 114       if line.startswith('#'):
 115         continue
 116       elif line.startswith('{'):
 117         pass
 118       elif line.startswith('}'):
 119         result.append(Suppression(cur_type, cur_descr, cur_stack))
 120         cur_descr = ''
 121         cur_type = ''
 122         cur_stack = []
 123       elif not cur_descr:
 124         cur_descr = line
 125         continue
 126       elif not cur_type:
 127         cur_type = line
 128         continue
 129       elif line.startswith('fun:'):
 130         line = line[4:]
 131         cur_stack.append(line.strip())
 132       elif line.startswith(ELLIPSIS):
 133         cur_stack.append(ELLIPSIS)
 134       else:
 135         raise SuppressionError(filename, nline,
 136                                '"fun:function_name" or "..." expected')
 137   except SuppressionError:
 138     input_file.close()
 139     raise
 140   return result
 141
 142
 143 def MatchTest():
 144   """Tests the Suppression.Match() capabilities."""
 145
 146   def GenSupp(*lines):
 147     return Suppression('', '', list(lines))
 148   empty = GenSupp()
 149   assert not empty.Match([])
 150   assert not empty.Match(['foo', 'bar'])
 151   asterisk = GenSupp('*bar')
 152   assert asterisk.Match(['foobar', 'foobaz'])
 153   assert not asterisk.Match(['foobaz', 'foobar'])
 154   ellipsis = GenSupp('...', 'foo')
 155   assert ellipsis.Match(['foo', 'bar'])
 156   assert ellipsis.Match(['bar', 'baz', 'foo'])
 157   assert not ellipsis.Match(['bar', 'baz', 'bah'])
 158   mixed = GenSupp('...', 'foo*', 'function')
 159   assert mixed.Match(['foobar', 'foobaz', 'function'])
 160   assert not mixed.Match(['foobar', 'blah', 'function'])
 161   at_and_dollar = GenSupp('foo@GLIBC', 'bar@NOCANCEL')
 162   assert at_and_dollar.Match(['foo@GLIBC', 'bar@NOCANCEL'])
 163   re_chars = GenSupp('.*')
 164   assert re_chars.Match(['.foobar'])
 165   assert not re_chars.Match(['foobar'])
 166   print 'PASS'
 167
 168
 169 if __name__ == '__main__':
 170   MatchTest()