solenv/gdb/libreoffice/util/string.py

   1 # -*- tab-width: 4; indent-tabs-mode: nil; py-indent-offset: 4 -*-
   2 #
   3 # This file is part of the LibreOffice project.
   4 #
   5 # This Source Code Form is subject to the terms of the Mozilla Public
   6 # License, v. 2.0. If a copy of the MPL was not distributed with this
   7 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8 #
   9
  10 import gdb
  11
  12 from libreoffice.util.compatibility import use_lazy_string
  13
  14 class StringPrinterHelper(object):
  15     '''Base for all string pretty printers'''
  16
  17     class MustBeImplemented(Exception):
  18         pass
  19
  20     def __init__(self, typename, val, encoding = None):
  21         self.typename = typename
  22         self.val = val
  23         self.encoding = encoding
  24
  25     def to_string(self):
  26         if self.valid():
  27             data = self.data()
  28             len = self.length()
  29             return self.make_string(data, self.encoding, len)
  30         else:
  31             return "unintialized %s" % self.typename
  32
  33     def display_hint(self):
  34         if self.valid():
  35             return 'string'
  36         else:
  37             return None
  38
  39     def valid(self):
  40         return True
  41
  42     def data(self):
  43         raise self.MustBeImplemented()
  44
  45     def length(self):
  46         return -1
  47
  48     @staticmethod
  49     def make_string(data, encoding = None, length = -1):
  50         '''Creates a new string from memory'''
  51
  52         if not encoding:
  53             encoding = ''
  54
  55         if use_lazy_string:
  56             return data.lazy_string(encoding, length)
  57
  58         # we need to determine length, if not given (for sal_Unicode*)
  59         if length < 0:
  60             length = 0
  61             while data[length] != 0 and length <= 512: # arbitrary limit
  62                 length += 1
  63
  64         # The gdb.Value.string() conversion works on array of bytes, but
  65         # the length we have is the length of the string. So we must
  66         # multiply it by width of character if the string is Unicode.
  67         width = data[0].type.sizeof
  68         if width > 1:
  69             length = length * width
  70
  71         char = gdb.lookup_type('char')
  72         bytes = data.cast(char.pointer())
  73         return bytes.string(encoding, length = length)
  74
  75 # vim:set shiftwidth=4 softtabstop=4 expandtab: