glib/gobject/gobject_gdb.py
Michael Olbrich d2c49106a4 gobject_gdb.py: add pretty printer for GType and GTypeClass*
This is useful for printing GValues and the content of GObjects (not the
pointer).

https://bugzilla.gnome.org/show_bug.cgi?id=794895
2018-04-11 14:31:53 +01:00

333 lines
10 KiB
Python

import os.path
import gdb
import glib_gdb
import sys
if sys.version_info[0] >= 3:
long = int
else:
import itertools
map = itertools.imap
# FrameDecorator is new in gdb 7.7, so we adapt to its absence.
try:
import gdb.FrameDecorator
HAVE_GDB_FRAMEDECORATOR = True
FrameDecorator = gdb.FrameDecorator.FrameDecorator
except ImportError:
HAVE_GDB_FRAMEDECORATOR = False
# This is not quite right, as local vars may override symname
def read_global_var (symname):
return gdb.selected_frame().read_var(symname)
def g_type_to_typenode (gtype):
def lookup_fundamental_type (typenode):
if typenode == 0:
return None
val = read_global_var ("static_fundamental_type_nodes")
if val == None:
return None
return val[typenode >> 2].address
gtype = long(gtype)
typenode = gtype - gtype % 4
if typenode > (255 << 2):
typenode = gdb.Value(typenode).cast (gdb.lookup_type("TypeNode").pointer())
else:
typenode = lookup_fundamental_type (typenode)
return typenode
def g_type_to_name (gtype):
typenode = g_type_to_typenode(gtype)
if typenode != None:
return glib_gdb.g_quark_to_string (typenode["qname"])
return None
def is_g_type_instance (val):
def is_g_type_instance_helper (type):
if str(type) == "GTypeInstance":
return True
while type.code == gdb.TYPE_CODE_TYPEDEF:
type = type.target()
if type.code != gdb.TYPE_CODE_STRUCT:
return False
fields = type.fields()
if len (fields) < 1:
return False
first_field = fields[0]
return is_g_type_instance_helper(first_field.type)
type = val.type
if type.code != gdb.TYPE_CODE_PTR:
return False
type = type.target()
return is_g_type_instance_helper (type)
def g_type_name_from_instance (instance):
if long(instance) != 0:
try:
inst = instance.cast (gdb.lookup_type("GTypeInstance").pointer())
klass = inst["g_class"]
gtype = klass["g_type"]
name = g_type_to_name (gtype)
return name
except RuntimeError:
pass
return None
class GTypePrettyPrinter:
"Prints a GType instance pointer"
def __init__ (self, val):
self.val = val
def to_string (self):
name = g_type_name_from_instance (self.val)
if name:
return ("0x%x [%s]")% (long(self.val), name)
return ("0x%x") % (long(self.val))
def is_g_type_class_instance (val):
type = val.type
if type.code != gdb.TYPE_CODE_PTR:
return False
return str(type.target()) == "GTypeClass"
class GTypeHandlePrettyPrinter:
"Prints a GType instance"
def __init__ (self, val, hint = ""):
self.val = val
self.hint = hint
def to_string (self):
typenode = g_type_to_typenode(self.val)
if typenode != None:
name = glib_gdb.g_quark_to_string (typenode["qname"])
s = ("0x%x [%s%s")% (long(self.val), self.hint, name)
for i in range (1, int(typenode["n_supers"])):
node = g_type_to_typenode(typenode["supers"][i])
if node:
name = glib_gdb.g_quark_to_string(node["qname"])
else:
name = "???"
s += "/" + name
return s + "]"
else:
return ("0x%x") % (long(self.val))
def pretty_printer_lookup (val):
if is_g_type_instance (val):
return GTypePrettyPrinter (val)
if str(val.type) == "GType":
return GTypeHandlePrettyPrinter (val)
if is_g_type_class_instance (val):
return GTypeHandlePrettyPrinter (val["g_type"], "g_type: ")
return None
def get_signal_name (id):
if id == None:
return None
id = long(id)
if id == 0:
return None
val = read_global_var ("g_signal_nodes")
max_s = read_global_var ("g_n_signal_nodes")
max_s = long(max_s)
if id < max_s:
return val[id]["name"].string()
return None
def frame_name(frame):
return str(frame.function())
def frame_var(frame, var):
return frame.inferior_frame().read_var(var)
class SignalFrame(FrameDecorator):
def __init__ (self, frames):
FrameDecorator.__init__(self, frames[-1])
self.frame = frames[-1]
self.frames = frames
def name (self):
return "signal-emission"
def read_var (self, frame, name, array = None):
try:
v = frame_var (frame, name)
if v == None or v.is_optimized_out:
return None
if array != None:
array.append (v)
return v
except ValueError:
return None
def read_object (self, frame, name, array = None):
try:
v = frame_var (frame, name)
if v == None or v.is_optimized_out:
return None
v = v.cast (gdb.lookup_type("GObject").pointer())
# Ensure this is a somewhat correct object pointer
if v != None and g_type_name_from_instance (v):
if array != None:
array.append (v)
return v
return None
except ValueError:
return None
def append (self, array, obj):
if obj != None:
array.append (obj)
def or_join_array (self, array):
if len(array) == 0:
return "???"
else:
return ' or '.join(set(map(str, array)))
def get_detailed_signal_from_frame(self, frame, signal):
detail = self.read_var (frame, "detail")
detail = glib_gdb.g_quark_to_string (detail)
if detail is not None:
return signal + ":" + detail
else:
return detail
def function (self):
instances = []
signals = []
for frame in self.frames:
name = frame_name(frame)
if name == "signal_emit_unlocked_R":
self.read_object (frame, "instance", instances)
node = self.read_var (frame, "node")
if node:
signal = node["name"].string()
signal = self.get_detailed_signal_from_frame(frame, signal)
self.append(signals, signal)
if name == "g_signal_emitv":
instance_and_params = self.read_var (frame, "instance_and_params")
if instance_and_params:
instance = instance_and_params[0]["v_pointer"].cast (gdb.Type("GObject").pointer())
self.append (instances, instance)
id = self.read_var (frame, "signal_id")
signal = get_signal_name (id)
if signal:
signal = self.get_detailed_signal_from_frame(frame, signal)
self.append (signals, signal)
if name == "g_signal_emit_valist" or name == "g_signal_emit":
self.read_object (frame, "instance", instances)
id = self.read_var (frame, "signal_id")
signal = get_signal_name (id)
if signal:
signal = self.get_detailed_signal_from_frame(frame, signal)
self.append (signals, signal)
if name == "g_signal_emit_by_name":
self.read_object (frame, "instance", instances)
self.read_var (frame, "detailed_signal", signals)
break
instance = self.or_join_array (instances)
signal = self.or_join_array (signals)
return "<emit signal %s on instance %s>" % (signal, instance)
def elided (self):
return self.frames[0:-1]
def describe (self, stream, full):
stream.write (" " + self.function () + "\n")
class GFrameDecorator:
def __init__ (self, iter):
self.queue = []
self.iter = iter
def __iter__ (self):
return self
def fill (self):
while len(self.queue) <= 8:
try:
f = next(self.iter)
self.queue.append (f)
except StopIteration:
return
def find_signal_emission (self):
for i in range (min (len(self.queue), 3)):
if frame_name(self.queue[i]) == "signal_emit_unlocked_R":
return i
return -1
def next (self):
# Ensure we have enough frames for a full signal emission
self.fill()
# Are we at the end?
if len(self.queue) == 0:
raise StopIteration
emission = self.find_signal_emission ()
if emission > 0:
start = emission
while True:
if start == 0:
break
prev_name = frame_name(self.queue[start-1])
if prev_name.find("_marshal_") >= 0 or prev_name == "g_closure_invoke":
start = start - 1
else:
break
end = emission + 1
while end < len(self.queue):
if frame_name(self.queue[end]) in ["g_signal_emitv",
"g_signal_emit_valist",
"g_signal_emit",
"g_signal_emit_by_name",
"_g_closure_invoke_va"]:
end = end + 1
else:
break
signal_frames = self.queue[start:end]
new_frames = [SignalFrame(signal_frames)]
self.queue[start:end] = new_frames
return self.queue.pop(0)
def __next__ (self):
return self.next()
class GFrameFilter(object):
name = 'glib'
enabled = True
priority = 100
def filter(self, iterator):
return GFrameDecorator(iterator)
def register (obj):
if obj == None:
obj = gdb
if HAVE_GDB_FRAMEDECORATOR:
filter = GFrameFilter()
obj.frame_filters[filter.name] = filter
obj.pretty_printers.append(pretty_printer_lookup)