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 21import gdb 22from gdb.unwinder import Unwinder 23 24apb_global = None 25 26class 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. 69gdb.unwinder.register_unwinder (None, dummy_unwinder (), True) 70 71print ("Python script imported") 72