GDB (xrefs)

unwinder.py
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1 # Copyright (C) 2015-2018 Free Software Foundation, Inc.
2
3 # This program is free software; you can redistribute it and/or modify
4 # it under the terms of the GNU General Public License as published by
5 # the Free Software Foundation; either version 3 of the License, or
6 # (at your option) any later version.
7 #
8 # This program is distributed in the hope that it will be useful,
9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 # GNU General Public License for more details.
12 #
13 # You should have received a copy of the GNU General Public License
14 # along with this program. If not, see <http://www.gnu.org/licenses/>.
15
16 """Unwinder class and register_unwinder function."""
17
18 import gdb
19
20
21 class Unwinder(object):
22 """Base class (or a template) for frame unwinders written in Python.
23
24 An unwinder has a single method __call__ and the attributes
25 described below.
26
27 Attributes:
28 name: The name of the unwinder.
29 enabled: A boolean indicating whether the unwinder is enabled.
30 """
31
32 def __init__(self, name):
33 """Constructor.
34
35 Args:
36 name: An identifying name for the unwinder.
37 """
38 self.name = name
39 self.enabled = True
40
41 def __call__(self, pending_frame):
42 """GDB calls this method to unwind a frame.
43
44 Arguments:
45 pending_frame: gdb.PendingFrame instance.
46
47 Returns:
48 gdb.UnwindInfo instance.
49 """
50 raise NotImplementedError("Unwinder __call__.")
51
52
53 def register_unwinder(locus, unwinder, replace=False):
54 """Register unwinder in given locus.
55
56 The unwinder is prepended to the locus's unwinders list. Unwinder
57 name should be unique.
58
59 Arguments:
60 locus: Either an objfile, progspace, or None (in which case
61 the unwinder is registered globally).
62 unwinder: An object of a gdb.Unwinder subclass
63 replace: If True, replaces existing unwinder with the same name.
64 Otherwise, raises exception if unwinder with the same
65 name already exists.
66
67 Returns:
68 Nothing.
69
70 Raises:
71 RuntimeError: Unwinder name is not unique
72 TypeError: Bad locus type
73 """
74 if locus is None:
75 if gdb.parameter("verbose"):
76 gdb.write("Registering global %s unwinder ...\n" % unwinder.name)
77 locus = gdb
78 elif isinstance(locus, gdb.Objfile) or isinstance(locus, gdb.Progspace):
79 if gdb.parameter("verbose"):
80 gdb.write("Registering %s unwinder for %s ...\n" %
81 (unwinder.name, locus.filename))
82 else:
83 raise TypeError("locus should be gdb.Objfile or gdb.Progspace or None")
84
85 i = 0
86 for needle in locus.frame_unwinders:
87 if needle.name == unwinder.name:
88 if replace:
89 del locus.frame_unwinders[i]
90 else:
91 raise RuntimeError("Unwinder %s already exists." %
92 unwinder.name)
93 i += 1
94 locus.frame_unwinders.insert(0, unwinder)
95 gdb.invalidate_cached_frames()
gdb.unwinder.Unwinder.name
name
Definition: unwinder.py:38
gdb.unwinder.Unwinder.__call__
def __call__(self, pending_frame)
Definition: unwinder.py:41
gdb.unwinder.Unwinder.enabled
enabled
Definition: unwinder.py:39
gdb.unwinder.Unwinder.__init__
def __init__(self, name)
Definition: unwinder.py:32
gdb.unwinder.Unwinder
Definition: unwinder.py:21
gdb.unwinder.register_unwinder
def register_unwinder(locus, unwinder, replace=False)
Definition: unwinder.py:53