gobject/gobject_gdb.py

   1 import os.path
   2 import gdb
   3 import glib_gdb
   4 import sys
   5
   6 if sys.version_info[0] >= 3:
   7     long = int
   8 else:
   9     import itertools
  10     map = itertools.imap
  11
  12 # FrameDecorator is new in gdb 7.7, so we adapt to its absence.
  13 try:
  14     import gdb.FrameDecorator
  15     HAVE_GDB_FRAMEDECORATOR = True
  16     FrameDecorator = gdb.FrameDecorator.FrameDecorator
  17 except ImportError:
  18     HAVE_GDB_FRAMEDECORATOR = False
  19
  20 # This is not quite right, as local vars may override symname
  21 def read_global_var (symname):
  22     return gdb.selected_frame().read_var(symname)
  23
  24 def g_type_to_name (gtype):
  25     def lookup_fundamental_type (typenode):
  26         if typenode == 0:
  27             return None
  28         val = read_global_var ("static_fundamental_type_nodes")
  29         if val == None:
  30             return None
  31         return val[typenode >> 2].address()
  32
  33     gtype = long(gtype)
  34     typenode = gtype - gtype % 4
  35     if typenode > (255 << 2):
  36         typenode = gdb.Value(typenode).cast (gdb.lookup_type("TypeNode").pointer())
  37     else:
  38         typenode = lookup_fundamental_type (typenode)
  39     if typenode != None:
  40         return glib_gdb.g_quark_to_string (typenode["qname"])
  41     return None
  42
  43 def is_g_type_instance (val):
  44     def is_g_type_instance_helper (type):
  45         if str(type) == "GTypeInstance":
  46             return True
  47
  48         while type.code == gdb.TYPE_CODE_TYPEDEF:
  49             type = type.target()
  50
  51         if type.code != gdb.TYPE_CODE_STRUCT:
  52             return False
  53
  54         fields = type.fields()
  55         if len (fields) < 1:
  56             return False
  57
  58         first_field = fields[0]
  59         return is_g_type_instance_helper(first_field.type)
  60
  61     type = val.type
  62     if type.code != gdb.TYPE_CODE_PTR:
  63         return False
  64     type = type.target()
  65     return is_g_type_instance_helper (type)
  66
  67 def g_type_name_from_instance (instance):
  68     if long(instance) != 0:
  69         try:
  70             inst = instance.cast (gdb.lookup_type("GTypeInstance").pointer())
  71             klass = inst["g_class"]
  72             gtype = klass["g_type"]
  73             name = g_type_to_name (gtype)
  74             return name
  75         except RuntimeError:
  76             pass
  77     return None
  78
  79 class GTypePrettyPrinter:
  80     "Prints a GType instance pointer"
  81
  82     def __init__ (self, val):
  83         self.val = val
  84
  85     def to_string (self):
  86         name = g_type_name_from_instance (self.val)
  87         if name:
  88             return ("0x%x [%s]")% (long(self.val), name)
  89         return  ("0x%x") % (long(self.val))
  90
  91 def pretty_printer_lookup (val):
  92     if is_g_type_instance (val):
  93         return GTypePrettyPrinter (val)
  94
  95     return None
  96
  97 def get_signal_name (id):
  98     if id == None:
  99         return None
 100     id = long(id)
 101     if id == 0:
 102         return None
 103     val = read_global_var ("g_signal_nodes")
 104     max_s = read_global_var ("g_n_signal_nodes")
 105     max_s = long(max_s)
 106     if id < max_s:
 107         return val[id]["name"].string()
 108     return None
 109
 110 def frame_name(frame):
 111     return str(frame.function())
 112
 113 def frame_var(frame, var):
 114     return frame.inferior_frame().read_var(var)
 115
 116
 117 class SignalFrame(FrameDecorator):
 118     def __init__ (self, frames):
 119         FrameDecorator.__init__(self, frames[-1])
 120         self.frame = frames[-1]
 121         self.frames = frames
 122
 123     def name (self):
 124         return "signal-emission"
 125
 126     def read_var (self, frame, name, array = None):
 127         try:
 128             v = frame_var (frame, name)
 129             if v == None or v.is_optimized_out:
 130                 return None
 131             if array != None:
 132                 array.append (v)
 133             return v
 134         except ValueError:
 135             return None
 136
 137     def read_object (self, frame, name, array = None):
 138         try:
 139             v = frame_var (frame, name)
 140             if v == None or v.is_optimized_out:
 141                 return None
 142             v = v.cast (gdb.lookup_type("GObject").pointer())
 143             # Ensure this is a somewhat correct object pointer
 144             if v != None and g_type_name_from_instance (v):
 145                 if array != None:
 146                     array.append (v)
 147                 return v
 148             return None
 149         except ValueError:
 150             return None
 151
 152     def append (self, array, obj):
 153         if obj != None:
 154             array.append (obj)
 155
 156     def or_join_array (self, array):
 157         if len(array) == 0:
 158             return "???"
 159         else:
 160             return ' or '.join(set(map(str, array)))
 161
 162     def get_detailed_signal_from_frame(self, frame, signal):
 163         detail = self.read_var (frame, "detail")
 164         detail = glib_gdb.g_quark_to_string (detail)
 165         if detail is not None:
 166             return signal + ":" + detail
 167         else:
 168             return detail
 169
 170     def function (self):
 171         instances = []
 172         signals = []
 173
 174         for frame in self.frames:
 175             name = frame_name(frame)
 176             if name == "signal_emit_unlocked_R":
 177                 self.read_object (frame, "instance", instances)
 178                 node = self.read_var (frame, "node")
 179                 if node:
 180                     signal = node["name"].string()
 181                     signal = self.get_detailed_signal_from_frame(frame, signal)
 182                     self.append(signals, signal)
 183
 184             if name == "g_signal_emitv":
 185                 instance_and_params = self.read_var (frame, "instance_and_params")
 186                 if instance_and_params:
 187                     instance = instance_and_params[0]["v_pointer"].cast (gdb.Type("GObject").pointer())
 188                     self.append (instances, instance)
 189                 id = self.read_var (frame, "signal_id")
 190                 signal = get_signal_name (id)
 191                 if signal:
 192                     signal = self.get_detailed_signal_from_frame(frame, signal)
 193                     self.append (signals, signal)
 194
 195             if name == "g_signal_emit_valist" or name == "g_signal_emit":
 196                 self.read_object (frame, "instance", instances)
 197                 id = self.read_var (frame, "signal_id")
 198                 signal = get_signal_name (id)
 199                 if signal:
 200                     signal = self.get_detailed_signal_from_frame(frame, signal)
 201                     self.append (signals, signal)
 202
 203             if name == "g_signal_emit_by_name":
 204                 self.read_object (frame, "instance", instances)
 205                 self.read_var (frame, "detailed_signal", signals)
 206                 break
 207
 208         instance = self.or_join_array (instances)
 209         signal = self.or_join_array (signals)
 210
 211         return "<emit signal %s on instance %s>" %  (signal, instance)
 212
 213     def elided (self):
 214         return self.frames[0:-1]
 215
 216     def describe (self, stream, full):
 217         stream.write (" " + self.function () + "\n")
 218
 219 class GFrameDecorator:
 220     def __init__ (self, iter):
 221         self.queue = []
 222         self.iter = iter
 223
 224     def __iter__ (self):
 225         return self
 226
 227     def fill (self):
 228         while len(self.queue) <= 8:
 229             try:
 230                 f = next(self.iter)
 231                 self.queue.append (f)
 232             except StopIteration:
 233                 return
 234
 235     def find_signal_emission (self):
 236         for i in range (min (len(self.queue), 3)):
 237             if frame_name(self.queue[i]) == "signal_emit_unlocked_R":
 238                 return i
 239         return -1
 240
 241     def next (self):
 242         # Ensure we have enough frames for a full signal emission
 243         self.fill()
 244
 245         # Are we at the end?
 246         if len(self.queue) == 0:
 247             raise StopIteration
 248
 249         emission = self.find_signal_emission ()
 250         if emission > 0:
 251             start = emission
 252             while True:
 253                 if start == 0:
 254                     break
 255                 prev_name = frame_name(self.queue[start-1])
 256                 if prev_name.find("_marshal_") >= 0 or prev_name == "g_closure_invoke":
 257                     start = start - 1
 258                 else:
 259                     break
 260             end = emission + 1
 261             while end < len(self.queue):
 262                 if frame_name(self.queue[end]) in ["g_signal_emitv",
 263                                                    "g_signal_emit_valist",
 264                                                    "g_signal_emit",
 265                                                    "g_signal_emit_by_name",
 266                                                    "_g_closure_invoke_va"]:
 267                     end = end + 1
 268                 else:
 269                     break
 270
 271             signal_frames = self.queue[start:end]
 272             new_frames = [SignalFrame(signal_frames)]
 273             self.queue[start:end] = new_frames
 274
 275         return self.queue.pop(0)
 276
 277     def __next__ (self):
 278         return self.next()
 279
 280 class GFrameFilter(object):
 281     name = 'glib'
 282     enabled = True
 283     priority = 100
 284
 285     def filter(self, iterator):
 286         return GFrameDecorator(iterator)
 287
 288 def register (obj):
 289     if obj == None:
 290         obj = gdb
 291
 292     if HAVE_GDB_FRAMEDECORATOR:
 293         filter = GFrameFilter()
 294         obj.frame_filters[filter.name] = filter
 295     obj.pretty_printers.append(pretty_printer_lookup)