gdb/testsuite/gdb.python/py-unwind-inline.py

   1 # Copyright (C) 2020 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
  21 import gdb
  22 from gdb.unwinder import Unwinder
  23
  24 apb_global = None
  25
  26 class dummy_unwinder (Unwinder):
  27     """ A dummy unwinder that looks at a bunch of registers as part of
  28     the unwinding process."""
  29
  30     class frame_id (object):
  31         """ Basic frame id."""
  32
  33         def __init__ (self, sp, pc):
  34             """ Create the frame id."""
  35             self.sp = sp
  36             self.pc = pc
  37
  38     def __init__ (self):
  39         """Create the unwinder."""
  40         Unwinder.__init__ (self, "dummy stack unwinder")
  41         self.void_ptr_t = gdb.lookup_type("void").pointer()
  42         self.regs = None
  43
  44     def get_regs (self, pending_frame):
  45         """Return a list of register names that should be read.  Only
  46         gathers the list once, then caches the result."""
  47         if (self.regs != None):
  48             return self.regs
  49
  50         # Collect the names of all registers to read.
  51         self.regs = list (pending_frame.architecture ()
  52                           .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 # Register the ComRV stack unwinder.
  69 gdb.unwinder.register_unwinder (None, dummy_unwinder (), True)
  70
  71 print ("Python script imported")