gdb/testsuite/gdb.base/premature-dummy-frame-removal.py

   1 # Copyright (C) 2021-2023 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 # This dummy unwinder will break GDB's backtrce at the function called
  17 # 'break_bt_here'.
  18
  19 import gdb
  20 from gdb.unwinder import Unwinder
  21
  22
  23 class FrameId(object):
  24     def __init__(self, sp, pc):
  25         self._sp = sp
  26         self._pc = pc
  27
  28     @property
  29     def sp(self):
  30         return self._sp
  31
  32     @property
  33     def pc(self):
  34         return self._pc
  35
  36
  37 class TestUnwinder(Unwinder):
  38     def __init__(self):
  39         Unwinder.__init__(self, "break unwinding")
  40
  41     def __call__(self, pending_frame):
  42         pc_desc = pending_frame.architecture().registers().find("pc")
  43         pc = pending_frame.read_register(pc_desc)
  44
  45         sp_desc = pending_frame.architecture().registers().find("sp")
  46         sp = pending_frame.read_register(sp_desc)
  47
  48         block = gdb.block_for_pc(int(pc))
  49         if block is None:
  50             return None
  51         func = block.function
  52         if func is None:
  53             return None
  54         if str(func) != "break_bt_here":
  55             return None
  56         fid = FrameId(pc, sp)
  57         return pending_frame.create_unwind_info(fid)
  58
  59
  60 gdb.unwinder.register_unwinder(None, TestUnwinder(), True)