gdb/testsuite/gdb.base/inline-frame-cycle-unwind.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 import gdb
  17 from gdb.unwinder import Unwinder
  18
  19 # Set this to the stack level the backtrace should be corrupted at.
  20 # This will only work for frame 1, 3, or 5 in the test this unwinder
  21 # was written for.
  22 stop_at_level = None
  23
  24 # Set this to the stack frame size of frames 1, 3, and 5.  These
  25 # frames will all have the same stack frame size as they are the same
  26 # function called recursively.
  27 stack_adjust = None
  28
  29
  30 class FrameId(object):
  31     def __init__(self, sp, pc):
  32         self._sp = sp
  33         self._pc = pc
  34
  35     @property
  36     def sp(self):
  37         return self._sp
  38
  39     @property
  40     def pc(self):
  41         return self._pc
  42
  43
  44 class TestUnwinder(Unwinder):
  45     def __init__(self):
  46         Unwinder.__init__(self, "stop at level")
  47
  48     def __call__(self, pending_frame):
  49         global stop_at_level
  50         global stack_adjust
  51
  52         if stop_at_level is None or pending_frame.level() != stop_at_level:
  53             return None
  54
  55         if stack_adjust is None:
  56             raise gdb.GdbError("invalid stack_adjust")
  57
  58         if not stop_at_level in [1, 3, 5]:
  59             raise gdb.GdbError("invalid stop_at_level")
  60
  61         sp_desc = pending_frame.architecture().registers().find("sp")
  62         sp = pending_frame.read_register(sp_desc) + stack_adjust
  63         pc = (gdb.lookup_symbol("normal_func"))[0].value().address
  64         unwinder = pending_frame.create_unwind_info(FrameId(sp, pc))
  65
  66         for reg in pending_frame.architecture().registers("general"):
  67             val = pending_frame.read_register(reg)
  68             unwinder.add_saved_register(reg, val)
  69         return unwinder
  70
  71
  72 gdb.unwinder.register_unwinder(None, TestUnwinder(), True)
  73
  74 # When loaded, it is expected that the stack looks like:
  75 #
  76 #   main -> normal_func -> inline_func -> normal_func -> inline_func -> normal_func -> inline_func
  77 #
  78 # Compute the stack frame size of normal_func, which has inline_func
  79 # inlined within it.
  80 f0 = gdb.newest_frame()
  81 f1 = f0.older()
  82 f2 = f1.older()
  83 f0_sp = f0.read_register("sp")
  84 f2_sp = f2.read_register("sp")
  85 stack_adjust = f2_sp - f0_sp