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_typenode (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     return typenode
  40
  41 def g_type_to_name (gtype):
  42     typenode = g_type_to_typenode(gtype)
  43     if typenode != None:
  44         return glib_gdb.g_quark_to_string (typenode["qname"])
  45     return None
  46
  47 def is_g_type_instance (val):
  48     def is_g_type_instance_helper (type):
  49         if str(type) == "GTypeInstance":
  50             return True
  51
  52         while type.code == gdb.TYPE_CODE_TYPEDEF:
  53             type = type.target()
  54
  55         if type.code != gdb.TYPE_CODE_STRUCT:
  56             return False
  57
  58         fields = type.fields()
  59         if len (fields) < 1:
  60             return False
  61
  62         first_field = fields[0]
  63         return is_g_type_instance_helper(first_field.type)
  64
  65     type = val.type
  66     if type.code != gdb.TYPE_CODE_PTR:
  67         return False
  68     type = type.target()
  69     return is_g_type_instance_helper (type)
  70
  71 def g_type_name_from_instance (instance):
  72     if long(instance) != 0:
  73         try:
  74             inst = instance.cast (gdb.lookup_type("GTypeInstance").pointer())
  75             klass = inst["g_class"]
  76             gtype = klass["g_type"]
  77             name = g_type_to_name (gtype)
  78             return name
  79         except RuntimeError:
  80             pass
  81     return None
  82
  83 class GTypePrettyPrinter:
  84     "Prints a GType instance pointer"
  85
  86     def __init__ (self, val):
  87         self.val = val
  88
  89     def to_string (self):
  90         name = g_type_name_from_instance (self.val)
  91         if name:
  92             return ("0x%x [%s]")% (long(self.val), name)
  93         return  ("0x%x") % (long(self.val))
  94
  95 def is_g_type_class_instance (val):
  96     type = val.type
  97     if type.code != gdb.TYPE_CODE_PTR:
  98         return False
  99     return str(type.target()) == "GTypeClass"
 100
 101 class GTypeHandlePrettyPrinter:
 102     "Prints a GType instance"
 103
 104     def __init__ (self, val, hint = ""):
 105         self.val = val
 106         self.hint = hint
 107
 108     def to_string (self):
 109         typenode = g_type_to_typenode(self.val)
 110         if typenode != None:
 111             name = glib_gdb.g_quark_to_string (typenode["qname"])
 112             s = ("0x%x [%s%s")% (long(self.val), self.hint, name)
 113             for i in range (1, int(typenode["n_supers"])):
 114                 node = g_type_to_typenode(typenode["supers"][i])
 115                 if node:
 116                     name = glib_gdb.g_quark_to_string(node["qname"])
 117                 else:
 118                     name = "???"
 119                 s += "/" + name
 120             return s + "]"
 121         else:
 122             return  ("0x%x") % (long(self.val))
 123
 124 def pretty_printer_lookup (val):
 125     if is_g_type_instance (val):
 126         return GTypePrettyPrinter (val)
 127     if str(val.type) == "GType":
 128         return GTypeHandlePrettyPrinter (val)
 129     if is_g_type_class_instance (val):
 130         return GTypeHandlePrettyPrinter (val["g_type"], "g_type: ")
 131
 132     return None
 133
 134 def get_signal_name (id):
 135     if id == None:
 136         return None
 137     id = long(id)
 138     if id == 0:
 139         return None
 140     val = read_global_var ("g_signal_nodes")
 141     max_s = read_global_var ("g_n_signal_nodes")
 142     max_s = long(max_s)
 143     if id < max_s:
 144         return val[id]["name"].string()
 145     return None
 146
 147 def frame_name(frame):
 148     return str(frame.function())
 149
 150 def frame_var(frame, var):
 151     return frame.inferior_frame().read_var(var)
 152
 153
 154 class SignalFrame(FrameDecorator):
 155     def __init__ (self, frames):
 156         FrameDecorator.__init__(self, frames[-1])
 157         self.frame = frames[-1]
 158         self.frames = frames
 159
 160     def name (self):
 161         return "signal-emission"
 162
 163     def read_var (self, frame, name, array = None):
 164         try:
 165             v = frame_var (frame, name)
 166             if v == None or v.is_optimized_out:
 167                 return None
 168             if array != None:
 169                 array.append (v)
 170             return v
 171         except ValueError:
 172             return None
 173
 174     def read_object (self, frame, name, array = None):
 175         try:
 176             v = frame_var (frame, name)
 177             if v == None or v.is_optimized_out:
 178                 return None
 179             v = v.cast (gdb.lookup_type("GObject").pointer())
 180             # Ensure this is a somewhat correct object pointer
 181             if v != None and g_type_name_from_instance (v):
 182                 if array != None:
 183                     array.append (v)
 184                 return v
 185             return None
 186         except ValueError:
 187             return None
 188
 189     def append (self, array, obj):
 190         if obj != None:
 191             array.append (obj)
 192
 193     def or_join_array (self, array):
 194         if len(array) == 0:
 195             return "???"
 196         else:
 197             return ' or '.join(set(map(str, array)))
 198
 199     def get_detailed_signal_from_frame(self, frame, signal):
 200         detail = self.read_var (frame, "detail")
 201         detail = glib_gdb.g_quark_to_string (detail)
 202         if detail is not None:
 203             return signal + ":" + detail
 204         else:
 205             return detail
 206
 207     def function (self):
 208         instances = []
 209         signals = []
 210
 211         for frame in self.frames:
 212             name = frame_name(frame)
 213             if name == "signal_emit_unlocked_R":
 214                 self.read_object (frame, "instance", instances)
 215                 node = self.read_var (frame, "node")
 216                 if node:
 217                     signal = node["name"].string()
 218                     signal = self.get_detailed_signal_from_frame(frame, signal)
 219                     self.append(signals, signal)
 220
 221             if name == "g_signal_emitv":
 222                 instance_and_params = self.read_var (frame, "instance_and_params")
 223                 if instance_and_params:
 224                     instance = instance_and_params[0]["v_pointer"].cast (gdb.Type("GObject").pointer())
 225                     self.append (instances, instance)
 226                 id = self.read_var (frame, "signal_id")
 227                 signal = get_signal_name (id)
 228                 if signal:
 229                     signal = self.get_detailed_signal_from_frame(frame, signal)
 230                     self.append (signals, signal)
 231
 232             if name == "g_signal_emit_valist" or name == "g_signal_emit":
 233                 self.read_object (frame, "instance", instances)
 234                 id = self.read_var (frame, "signal_id")
 235                 signal = get_signal_name (id)
 236                 if signal:
 237                     signal = self.get_detailed_signal_from_frame(frame, signal)
 238                     self.append (signals, signal)
 239
 240             if name == "g_signal_emit_by_name":
 241                 self.read_object (frame, "instance", instances)
 242                 self.read_var (frame, "detailed_signal", signals)
 243                 break
 244
 245         instance = self.or_join_array (instances)
 246         signal = self.or_join_array (signals)
 247
 248         return "<emit signal %s on instance %s>" %  (signal, instance)
 249
 250     def elided (self):
 251         return self.frames[0:-1]
 252
 253     def describe (self, stream, full):
 254         stream.write (" " + self.function () + "\n")
 255
 256 class GFrameDecorator:
 257     def __init__ (self, iter):
 258         self.queue = []
 259         self.iter = iter
 260
 261     def __iter__ (self):
 262         return self
 263
 264     def fill (self):
 265         while len(self.queue) <= 8:
 266             try:
 267                 f = next(self.iter)
 268                 self.queue.append (f)
 269             except StopIteration:
 270                 return
 271
 272     def find_signal_emission (self):
 273         for i in range (min (len(self.queue), 3)):
 274             if frame_name(self.queue[i]) == "signal_emit_unlocked_R":
 275                 return i
 276         return -1
 277
 278     def next (self):
 279         # Ensure we have enough frames for a full signal emission
 280         self.fill()
 281
 282         # Are we at the end?
 283         if len(self.queue) == 0:
 284             raise StopIteration
 285
 286         emission = self.find_signal_emission ()
 287         if emission > 0:
 288             start = emission
 289             while True:
 290                 if start == 0:
 291                     break
 292                 prev_name = frame_name(self.queue[start-1])
 293                 if prev_name.find("_marshal_") >= 0 or prev_name == "g_closure_invoke":
 294                     start = start - 1
 295                 else:
 296                     break
 297             end = emission + 1
 298             while end < len(self.queue):
 299                 if frame_name(self.queue[end]) in ["g_signal_emitv",
 300                                                    "g_signal_emit_valist",
 301                                                    "g_signal_emit",
 302                                                    "g_signal_emit_by_name",
 303                                                    "_g_closure_invoke_va"]:
 304                     end = end + 1
 305                 else:
 306                     break
 307
 308             signal_frames = self.queue[start:end]
 309             new_frames = [SignalFrame(signal_frames)]
 310             self.queue[start:end] = new_frames
 311
 312         return self.queue.pop(0)
 313
 314     def __next__ (self):
 315         return self.next()
 316
 317 class GFrameFilter(object):
 318     name = 'glib'
 319     enabled = True
 320     priority = 100
 321
 322     def filter(self, iterator):
 323         return GFrameDecorator(iterator)
 324
 325 def register (obj):
 326     if obj == None:
 327         obj = gdb
 328
 329     if HAVE_GDB_FRAMEDECORATOR:
 330         filter = GFrameFilter()
 331         obj.frame_filters[filter.name] = filter
 332     obj.pretty_printers.append(pretty_printer_lookup)