Files
binutils-gdb/gdb/python/lib/gdb/unwinder.py
Tom Tromey e0f3fd7c44 PR python/19293 - invalidate frame cache when unwinders change
PR python/19293 notes that when a Python unwinder is disabled, the
frame cache is not invalidated.  This means that disabling an unwinder
doesn't have any immediate effect -- but in my experience it's often
the case that I want to enable or disable an unwinder in order to see
what happens.

This patch adds a new gdb.invalidate_cached_frames function and
arranges for the relevant bits of library code to call it.  I've only
partially documented this function, considering a warning sufficient
without going into all the reasons ordinary code should not call it.
The name of the new function was taken from a comment in frame.h next
to reinit_frame_cache.

No new test as I think the updates to the existing test are sufficient
to show that the code is working as intended.

Built and regtested on x86-64 Fedora 23.

2016-07-12  Tom Tromey  <tom@tromey.com>

	PR python/19293:
	* python/lib/gdb/command/unwinders.py (do_enable_unwinder): Call
	gdb.invalidate_cached_frames.
	* python/lib/gdb/unwinder.py (register_unwinder): Call
	gdb.invalidate_cached_frames.
	* python/python.c (gdbpy_invalidate_cached_frames): New function.
	(python_GdbMethods): Add entry for invalidate_cached_frames.

2016-07-12  Tom Tromey  <tom@tromey.com>

	PR python/19293:
	* python.texi (Frames In Python): Document
	gdb.invalidate_cached_frames.

2016-07-12  Tom Tromey  <tom@tromey.com>

	PR python/19293:
	* gdb.python/py-unwind-maint.exp: Update tests.
2016-07-12 13:56:07 -06:00

96 lines
3.1 KiB
Python

# Copyright (C) 2015-2016 Free Software Foundation, Inc.
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
"""Unwinder class and register_unwinder function."""
import gdb
class Unwinder(object):
"""Base class (or a template) for frame unwinders written in Python.
An unwinder has a single method __call__ and the attributes
described below.
Attributes:
name: The name of the unwinder.
enabled: A boolean indicating whether the unwinder is enabled.
"""
def __init__(self, name):
"""Constructor.
Args:
name: An identifying name for the unwinder.
"""
self.name = name
self.enabled = True
def __call__(self, pending_frame):
"""GDB calls this method to unwind a frame.
Arguments:
pending_frame: gdb.PendingFrame instance.
Returns:
gdb.UnwindInfo instance.
"""
raise NotImplementedError("Unwinder __call__.")
def register_unwinder(locus, unwinder, replace=False):
"""Register unwinder in given locus.
The unwinder is prepended to the locus's unwinders list. Unwinder
name should be unique.
Arguments:
locus: Either an objfile, progspace, or None (in which case
the unwinder is registered globally).
unwinder: An object of a gdb.Unwinder subclass
replace: If True, replaces existing unwinder with the same name.
Otherwise, raises exception if unwinder with the same
name already exists.
Returns:
Nothing.
Raises:
RuntimeError: Unwinder name is not unique
TypeError: Bad locus type
"""
if locus is None:
if gdb.parameter("verbose"):
gdb.write("Registering global %s unwinder ...\n" % unwinder.name)
locus = gdb
elif isinstance(locus, gdb.Objfile) or isinstance(locus, gdb.Progspace):
if gdb.parameter("verbose"):
gdb.write("Registering %s unwinder for %s ...\n" %
(unwinder.name, locus.filename))
else:
raise TypeError("locus should be gdb.Objfile or gdb.Progspace or None")
i = 0
for needle in locus.frame_unwinders:
if needle.name == unwinder.name:
if replace:
del locus.frame_unwinders[i]
else:
raise RuntimeError("Unwinder %s already exists." %
unwinder.name)
i += 1
locus.frame_unwinders.insert(0, unwinder)
gdb.invalidate_cached_frames()