gdb/python/lib/gdb/dap/bt.py

   1 # Copyright 2022-2023 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 import os
  18
  19 from .frames import frame_id
  20 from .server import request, capability
  21 from .startup import send_gdb_with_response, in_gdb_thread
  22 from .state import set_thread
  23
  24
  25 # Helper function to safely get the name of a frame as a string.
  26 @in_gdb_thread
  27 def _frame_name(frame):
  28     name = frame.name()
  29     if name is None:
  30         name = "???"
  31     return name
  32
  33
  34 # Helper function to get a frame's SAL without an error.
  35 @in_gdb_thread
  36 def _safe_sal(frame):
  37     try:
  38         return frame.find_sal()
  39     except gdb.error:
  40         return None
  41
  42
  43 # Helper function to compute a stack trace.
  44 @in_gdb_thread
  45 def _backtrace(thread_id, levels, startFrame):
  46     set_thread(thread_id)
  47     frames = []
  48     current_number = 0
  49     try:
  50         current_frame = gdb.newest_frame()
  51     except gdb.error:
  52         current_frame = None
  53     # Note that we always iterate over all frames, which is lame, but
  54     # seemingly necessary to support the totalFrames response.
  55     # FIXME maybe the mildly mysterious note about "monotonically
  56     # increasing totalFrames values" would let us fix this.
  57     while current_frame is not None:
  58         # This condition handles the startFrame==0 case as well.
  59         if current_number >= startFrame and (levels == 0 or len(frames) < levels):
  60             newframe = {
  61                 "id": frame_id(current_frame),
  62                 "name": _frame_name(current_frame),
  63                 # This must always be supplied, but we will set it
  64                 # correctly later if that is possible.
  65                 "line": 0,
  66                 # GDB doesn't support columns.
  67                 "column": 0,
  68                 "instructionPointerReference": hex(current_frame.pc()),
  69             }
  70             sal = _safe_sal(current_frame)
  71             if sal is not None and sal.symtab is not None:
  72                 newframe["source"] = {
  73                     "name": os.path.basename(sal.symtab.filename),
  74                     "path": sal.symtab.filename,
  75                     # We probably don't need this but it doesn't hurt
  76                     # to be explicit.
  77                     "sourceReference": 0,
  78                 }
  79                 newframe["line"] = sal.line
  80             frames.append(newframe)
  81         current_number = current_number + 1
  82         current_frame = current_frame.older()
  83     return {
  84         "stackFrames": frames,
  85         "totalFrames": current_number,
  86     }
  87
  88
  89 @request("stackTrace")
  90 @capability("supportsDelayedStackTraceLoading")
  91 def stacktrace(*, levels: int = 0, startFrame: int = 0, threadId: int, **extra):
  92     return send_gdb_with_response(lambda: _backtrace(threadId, levels, startFrame))