gdb/python/lib/gdb/types.py

   1 # Type utilities.
   2 # Copyright (C) 2010, 2011 Free Software Foundation, Inc.
   3
   4 # This program is free software; you can redistribute it and/or modify
   5 # it under the terms of the GNU General Public License as published by
   6 # the Free Software Foundation; either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 """Utilities for working with gdb.Types."""
  18
  19 import gdb
  20
  21
  22 def get_basic_type(type_):
  23     """Return the "basic" type of a type.
  24
  25     Arguments:
  26         type_: The type to reduce to its basic type.
  27
  28     Returns:
  29         type_ with const/volatile is stripped away,
  30         and typedefs/references converted to the underlying type.
  31     """
  32
  33     while (type_.code == gdb.TYPE_CODE_REF or
  34            type_.code == gdb.TYPE_CODE_TYPEDEF):
  35         if type_.code == gdb.TYPE_CODE_REF:
  36             type_ = type_.target()
  37         else:
  38             type_ = type_.strip_typedefs()
  39     return type_.unqualified()
  40
  41
  42 def has_field(type_, field):
  43     """Return True if a type has the specified field.
  44
  45     Arguments:
  46         type_: The type to examine.
  47             It must be one of gdb.TYPE_CODE_STRUCT, gdb.TYPE_CODE_UNION.
  48         field: The name of the field to look up.
  49
  50     Returns:
  51         True if the field is present either in type_ or any baseclass.
  52
  53     Raises:
  54         TypeError: The type is not a struct or union.
  55     """
  56
  57     type_ = get_basic_type(type_)
  58     if (type_.code != gdb.TYPE_CODE_STRUCT and
  59         type_.code != gdb.TYPE_CODE_UNION):
  60         raise TypeError("not a struct or union")
  61     for f in type_.fields():
  62         if f.is_base_class:
  63             if has_field(f.type, field):
  64                 return True
  65         else:
  66             # NOTE: f.name could be None
  67             if f.name == field:
  68                 return True
  69     return False
  70
  71
  72 def make_enum_dict(enum_type):
  73     """Return a dictionary from a program's enum type.
  74
  75     Arguments:
  76         enum_type: The enum to compute the dictionary for.
  77
  78     Returns:
  79         The dictionary of the enum.
  80
  81     Raises:
  82         TypeError: The type is not an enum.
  83     """
  84
  85     if enum_type.code != gdb.TYPE_CODE_ENUM:
  86         raise TypeError("not an enum type")
  87     enum_dict = {}
  88     for field in enum_type.fields():
  89         # The enum's value is stored in "bitpos".
  90         enum_dict[field.name] = field.bitpos
  91     return enum_dict