media/webrtc/trunk/tools/valgrind/gdb_helper.py

   1 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4
   5 ''' A bunch of helper functions for querying gdb.'''
   6
   7 import logging
   8 import os
   9 import re
  10 import tempfile
  11
  12 GDB_LINE_RE = re.compile(r'Line ([0-9]*) of "([^"]*)".*')
  13
  14 def _GdbOutputToFileLine(output_line):
  15   ''' Parse the gdb output line, return a pair (file, line num) '''
  16   match =  GDB_LINE_RE.match(output_line)
  17   if match:
  18     return match.groups()[1], match.groups()[0]
  19   else:
  20     return None
  21
  22 def ResolveAddressesWithinABinary(binary_name, load_address, address_list):
  23   ''' For each address, return a pair (file, line num) '''
  24   commands = tempfile.NamedTemporaryFile()
  25   commands.write('add-symbol-file "%s" %s\n' % (binary_name, load_address))
  26   for addr in address_list:
  27     commands.write('info line *%s\n' % addr)
  28   commands.write('quit\n')
  29   commands.flush()
  30   gdb_commandline = 'gdb -batch -x %s 2>/dev/null' % commands.name
  31   gdb_pipe = os.popen(gdb_commandline)
  32   result = gdb_pipe.readlines()
  33
  34   address_count = 0
  35   ret = {}
  36   for line in result:
  37     if line.startswith('Line'):
  38       ret[address_list[address_count]] = _GdbOutputToFileLine(line)
  39       address_count += 1
  40     if line.startswith('No line'):
  41       ret[address_list[address_count]] = (None, None)
  42       address_count += 1
  43   gdb_pipe.close()
  44   commands.close()
  45   return ret
  46
  47 class AddressTable(object):
  48   ''' Object to do batched line number lookup. '''
  49   def __init__(self):
  50     self._load_addresses = {}
  51     self._binaries = {}
  52     self._all_resolved = False
  53
  54   def AddBinaryAt(self, binary, load_address):
  55     ''' Register a new shared library or executable. '''
  56     self._load_addresses[binary] = load_address
  57
  58   def Add(self, binary, address):
  59     ''' Register a lookup request. '''
  60     if binary == '':
  61       logging.warn('adding address %s in empty binary?' % address)
  62     if binary in self._binaries:
  63       self._binaries[binary].append(address)
  64     else:
  65       self._binaries[binary] = [address]
  66     self._all_resolved = False
  67
  68   def ResolveAll(self):
  69     ''' Carry out all lookup requests. '''
  70     self._translation = {}
  71     for binary in self._binaries.keys():
  72       if binary != '' and binary in self._load_addresses:
  73         load_address = self._load_addresses[binary]
  74         addr = ResolveAddressesWithinABinary(
  75             binary, load_address, self._binaries[binary])
  76         self._translation[binary] = addr
  77     self._all_resolved = True
  78
  79   def GetFileLine(self, binary, addr):
  80     ''' Get the (filename, linenum) result of a previously-registered lookup
  81     request.
  82     '''
  83     if self._all_resolved:
  84       if binary in self._translation:
  85         if addr in self._translation[binary]:
  86           return self._translation[binary][addr]
  87     return (None, None)