xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/testsuite/gdb.python/py-unwind-inline.py (revision dcc4f12d8d65994207fd5f741e1a058e79538559)
1# Copyright (C) 2020-2023 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# A dummy stack unwinder used for testing the Python unwinders when we
17# have inline frames.  This unwinder will never claim any frames,
18# instead, all it does it try to read all registers possible target
19# registers as part of the frame sniffing process..
20
21import gdb
22from gdb.unwinder import Unwinder
23
24apb_global = None
25
26
27class dummy_unwinder(Unwinder):
28    """A dummy unwinder that looks at a bunch of registers as part of
29    the unwinding process."""
30
31    class frame_id(object):
32        """Basic frame id."""
33
34        def __init__(self, sp, pc):
35            """Create the frame id."""
36            self.sp = sp
37            self.pc = pc
38
39    def __init__(self):
40        """Create the unwinder."""
41        Unwinder.__init__(self, "dummy stack unwinder")
42        self.void_ptr_t = gdb.lookup_type("void").pointer()
43        self.regs = None
44
45    def get_regs(self, pending_frame):
46        """Return a list of register names that should be read.  Only
47        gathers the list once, then caches the result."""
48        if self.regs is not None:
49            return self.regs
50
51        # Collect the names of all registers to read.
52        self.regs = list(pending_frame.architecture().register_names())
53
54        return self.regs
55
56    def __call__(self, pending_frame):
57        """Actually performs the unwind, or at least sniffs this frame
58        to see if the unwinder should claim it, which is never does."""
59        try:
60            for r in self.get_regs(pending_frame):
61                v = pending_frame.read_register(r).cast(self.void_ptr_t)
62        except:
63            print("Dummy unwinder, exception")
64            raise
65
66        return None
67
68
69# Register the ComRV stack unwinder.
70gdb.unwinder.register_unwinder(None, dummy_unwinder(), True)
71
72print("Python script imported")
73