gdb/gdb-gdb.py

   1 # Copyright (C) 2009, 2010, 2011 Free Software Foundation, Inc.
   2 #
   3 # This file is part of GDB.
   4 #
   5 # This program is free software; you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation; either version 3 of the License, or
   8 # (at your option) any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 import gdb
  19 import os.path
  20
  21 class TypeFlag:
  22     """A class that allows us to store a flag name, its short name,
  23     and its value.
  24
  25     In the GDB sources, struct type has a component called instance_flags
  26     in which the value is the addition of various flags.  These flags are
  27     defined by two enumerates: type_flag_value, and type_instance_flag_value.
  28     This class helps us recreate a list with all these flags that is
  29     easy to manipulate and sort.  Because all flag names start with either
  30     TYPE_FLAG_ or TYPE_INSTANCE_FLAG_, a short_name attribute is provided
  31     that strips this prefix.
  32
  33     ATTRIBUTES
  34       name:  The enumeration name (eg: "TYPE_FLAG_UNSIGNED").
  35       value: The associated value.
  36       short_name: The enumeration name, with the suffix stripped.
  37     """
  38     def __init__(self, name, value):
  39         self.name = name
  40         self.value = value
  41         self.short_name = name.replace("TYPE_FLAG_", '')
  42         if self.short_name == name:
  43             self.short_name = name.replace("TYPE_INSTANCE_FLAG_", '')
  44     def __cmp__(self, other):
  45         """Sort by value order."""
  46         return self.value.__cmp__(other.value)
  47
  48 # A list of all existing TYPE_FLAGS_* and TYPE_INSTANCE_FLAGS_*
  49 # enumerations, stored as TypeFlags objects.  Lazy-initialized.
  50 TYPE_FLAGS = None
  51
  52 class TypeFlagsPrinter:
  53     """A class that prints a decoded form of an instance_flags value.
  54
  55     This class uses a global named TYPE_FLAGS, which is a list of
  56     all defined TypeFlag values.  Using a global allows us to compute
  57     this list only once.
  58
  59     This class relies on a couple of enumeration types being defined.
  60     If not, then printing of the instance_flag is going to be degraded,
  61     but it's not a fatal error.
  62     """
  63     def __init__(self, val):
  64         self.val = val
  65     def __str__(self):
  66         global TYPE_FLAGS
  67         if TYPE_FLAGS is None:
  68             self.init_TYPE_FLAGS()
  69         if not self.val:
  70             return "0"
  71         if TYPE_FLAGS:
  72             flag_list = [flag.short_name for flag in TYPE_FLAGS
  73                          if self.val & flag.value]
  74         else:
  75             flag_list = ["???"]
  76         return "0x%x [%s]" % (self.val, "|".join(flag_list))
  77     def init_TYPE_FLAGS(self):
  78         """Initialize the TYPE_FLAGS global as a list of TypeFlag objects.
  79         This operation requires the search of a couple of enumeration types.
  80         If not found, a warning is printed on stdout, and TYPE_FLAGS is
  81         set to the empty list.
  82
  83         The resulting list is sorted by increasing value, to facilitate
  84         printing of the list of flags used in an instance_flags value.
  85         """
  86         global TYPE_FLAGS
  87         TYPE_FLAGS = []
  88         try:
  89             flags = gdb.lookup_type("enum type_flag_value")
  90         except:
  91             print "Warning: Cannot find enum type_flag_value type."
  92             print "         `struct type' pretty-printer will be degraded"
  93             return
  94         try:
  95             iflags = gdb.lookup_type("enum type_instance_flag_value")
  96         except:
  97             print "Warning: Cannot find enum type_instance_flag_value type."
  98             print "         `struct type' pretty-printer will be degraded"
  99             return
 100         # Note: TYPE_FLAG_MIN is a duplicate of TYPE_FLAG_UNSIGNED,
 101         # so exclude it from the list we are building.
 102         TYPE_FLAGS = [TypeFlag(field.name, field.bitpos)
 103                       for field in flags.fields()
 104                       if field.name != 'TYPE_FLAG_MIN']
 105         TYPE_FLAGS += [TypeFlag(field.name, field.bitpos)
 106                        for field in iflags.fields()]
 107         TYPE_FLAGS.sort()
 108
 109 class StructTypePrettyPrinter:
 110     """Pretty-print an object of type struct type"""
 111     def __init__(self, val):
 112         self.val = val
 113     def to_string(self):
 114         fields = []
 115         fields.append("pointer_type = %s" % self.val['pointer_type'])
 116         fields.append("reference_type = %s" % self.val['reference_type'])
 117         fields.append("chain = %s" % self.val['reference_type'])
 118         fields.append("instance_flags = %s"
 119                       % TypeFlagsPrinter(self.val['instance_flags']))
 120         fields.append("length = %d" % self.val['length'])
 121         fields.append("main_type = %s" % self.val['main_type'])
 122         return "\n{" + ",\n ".join(fields) + "}"
 123
 124 class StructMainTypePrettyPrinter:
 125     """Pretty-print an objet of type main_type"""
 126     def __init__(self, val):
 127         self.val = val
 128     def flags_to_string(self):
 129         """struct main_type contains a series of components that
 130         are one-bit ints whose name start with "flag_".  For instance:
 131         flag_unsigned, flag_stub, etc.  In essence, these components are
 132         really boolean flags, and this method prints a short synthetic
 133         version of the value of all these flags.  For instance, if
 134         flag_unsigned and flag_static are the only components set to 1,
 135         this function will return "unsigned|static".
 136         """
 137         fields = [field.name.replace("flag_", "")
 138                   for field in self.val.type.fields()
 139                   if field.name.startswith("flag_")
 140                      and self.val[field.name]]
 141         return "|".join(fields)
 142     def owner_to_string(self):
 143         """Return an image of component "owner".
 144         """
 145         if self.val['flag_objfile_owned'] != 0:
 146             return "%s (objfile)" % self.val['owner']['objfile']
 147         else:
 148             return "%s (gdbarch)" % self.val['owner']['gdbarch']
 149     def struct_field_location_img(self, field_val):
 150         """Return an image of the loc component inside the given field
 151         gdb.Value.
 152         """
 153         loc_val = field_val['loc']
 154         loc_kind = str(field_val['loc_kind'])
 155         if loc_kind == "FIELD_LOC_KIND_BITPOS":
 156             return 'bitpos = %d' % loc_val['bitpos']
 157         elif loc_kind == "FIELD_LOC_KIND_PHYSADDR":
 158             return 'physaddr = 0x%x' % loc_val['physaddr']
 159         elif loc_kind == "FIELD_LOC_KIND_PHYSNAME":
 160             return 'physname = %s' % loc_val['physname']
 161         else:
 162             return 'loc = ??? (unsupported loc_kind value)'
 163     def struct_field_img(self, fieldno):
 164         """Return an image of the main_type field number FIELDNO.
 165         """
 166         f = self.val['flds_bnds']['fields'][fieldno]
 167         label = "field[%d]:" % fieldno
 168         if f['artificial']:
 169             label += " (artificial)"
 170         fields = []
 171         fields.append("name = %s" % f['name'])
 172         fields.append("type = %s" % f['type'])
 173         fields.append("loc_kind = %s" % f['loc_kind'])
 174         fields.append("bitsize = %d" % f['bitsize'])
 175         fields.append(self.struct_field_location_img(f))
 176         return label + "\n" + "  {" + ",\n   ".join(fields) + "}"
 177     def bounds_img(self):
 178         """Return an image of the main_type bounds.
 179         """
 180         b = self.val['flds_bnds']['bounds'].dereference()
 181         low = str(b['low'])
 182         if b['low_undefined'] != 0:
 183             low += " (undefined)"
 184         high = str(b['high'])
 185         if b['high_undefined'] != 0:
 186             high += " (undefined)"
 187         return "bounds = {%s, %s}" % (low, high)
 188     def type_specific_img(self):
 189         """Return a string image of the main_type type_specific union.
 190         Only the relevant component of that union is printed (based on
 191         the value of the type_specific_kind field.
 192         """
 193         type_specific_kind = str(self.val['type_specific_field'])
 194         type_specific = self.val['type_specific']
 195         if type_specific_kind == "TYPE_SPECIFIC_NONE":
 196             img = 'type_specific_field = %s' % type_specific_kind
 197         elif type_specific_kind == "TYPE_SPECIFIC_CPLUS_STUFF":
 198             img = "cplus_stuff = %s" % type_specific['cplus_stuff']
 199         elif type_specific_kind == "TYPE_SPECIFIC_GNAT_STUFF":
 200             img = ("gnat_stuff = {descriptive_type = %s}"
 201                    % type_specific['gnat_stuff']['descriptive_type'])
 202         elif type_specific_kind == "TYPE_SPECIFIC_FLOATFORMAT":
 203             img = "floatformat[0..1] = %s" % type_specific['floatformat']
 204         elif type_specific_kind == "TYPE_SPECIFIC_CALLING_CONVENTION":
 205             img = ("calling_convention = %d"
 206                    % type_specific['calling_convention'])
 207         else:
 208             img = ("type_specific = ??? (unknown type_secific_kind: %s)"
 209                    % type_specific_kind)
 210         return img
 211
 212     def to_string(self):
 213         """Return a pretty-printed image of our main_type.
 214         """
 215         fields = []
 216         fields.append("name = %s" % self.val['name'])
 217         fields.append("tag_name = %s" % self.val['tag_name'])
 218         fields.append("code = %s" % self.val['code'])
 219         fields.append("flags = [%s]" % self.flags_to_string())
 220         fields.append("owner = %s" % self.owner_to_string())
 221         fields.append("target_type = %s" % self.val['target_type'])
 222         fields.append("vptr_basetype = %s" % self.val['vptr_basetype'])
 223         if self.val['nfields'] > 0:
 224             for fieldno in range(self.val['nfields']):
 225                 fields.append(self.struct_field_img(fieldno))
 226         if self.val['code'] == gdb.TYPE_CODE_RANGE:
 227             fields.append(self.bounds_img())
 228         fields.append(self.type_specific_img())
 229
 230         return "\n{" + ",\n ".join(fields) + "}"
 231
 232 def type_lookup_function(val):
 233     """A routine that returns the correct pretty printer for VAL
 234     if appropriate.  Returns None otherwise.
 235     """
 236     if val.type.tag == "type":
 237         return StructTypePrettyPrinter(val)
 238     elif val.type.tag == "main_type":
 239         return StructMainTypePrettyPrinter(val)
 240     return None
 241
 242 def register_pretty_printer(objfile):
 243     """A routine to register a pretty-printer against the given OBJFILE.
 244     """
 245     objfile.pretty_printers.append(type_lookup_function)
 246
 247 if __name__ == "__main__":
 248     if gdb.current_objfile() is not None:
 249         # This is the case where this script is being "auto-loaded"
 250         # for a given objfile.  Register the pretty-printer for that
 251         # objfile.
 252         register_pretty_printer(gdb.current_objfile())
 253     else:
 254         # We need to locate the objfile corresponding to the GDB
 255         # executable, and register the pretty-printer for that objfile.
 256         # FIXME: The condition used to match the objfile is too simplistic
 257         # and will not work on Windows.
 258         for objfile in gdb.objfiles():
 259             if os.path.basename(objfile.filename) == "gdb":
 260                 objfile.pretty_printers.append(type_lookup_function)