gdb/python/lib/gdb/dap/evaluate.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 gdb.printing
  18
  19 # This is deprecated in 3.9, but required in older versions.
  20 from typing import Optional
  21
  22 from .frames import frame_for_id
  23 from .server import request
  24 from .startup import send_gdb_with_response, in_gdb_thread
  25 from .varref import find_variable, VariableReference
  26
  27
  28 class EvaluateResult(VariableReference):
  29     def __init__(self, value):
  30         super().__init__(None, value, "result")
  31
  32
  33 # Helper function to evaluate an expression in a certain frame.
  34 @in_gdb_thread
  35 def _evaluate(expr, frame_id):
  36     global_context = True
  37     if frame_id is not None:
  38         frame = frame_for_id(frame_id)
  39         frame.select()
  40         global_context = False
  41     val = gdb.parse_and_eval(expr, global_context=global_context)
  42     ref = EvaluateResult(val)
  43     return ref.to_object()
  44
  45
  46 # Helper function to evaluate a gdb command in a certain frame.
  47 @in_gdb_thread
  48 def _repl(command, frame_id):
  49     if frame_id is not None:
  50         frame = frame_for_id(frame_id)
  51         frame.select()
  52     val = gdb.execute(command, from_tty=True, to_string=True)
  53     return {
  54         "result": val,
  55         "variablesReference": 0,
  56     }
  57
  58
  59 # FIXME supportsVariableType handling
  60 @request("evaluate")
  61 def eval_request(
  62     *,
  63     expression: str,
  64     frameId: Optional[int] = None,
  65     context: str = "variables",
  66     **args,
  67 ):
  68     if context in ("watch", "variables"):
  69         # These seem to be expression-like.
  70         return send_gdb_with_response(lambda: _evaluate(expression, frameId))
  71     elif context == "repl":
  72         return send_gdb_with_response(lambda: _repl(expression, frameId))
  73     else:
  74         raise Exception(f'unknown evaluate context "{context}"')
  75
  76
  77 @in_gdb_thread
  78 def _variables(ref, start, count):
  79     var = find_variable(ref)
  80     children = var.fetch_children(start, count)
  81     return [x.to_object() for x in children]
  82
  83
  84 @request("variables")
  85 # Note that we ignore the 'filter' field.  That seems to be
  86 # specific to javascript.
  87 def variables(*, variablesReference: int, start: int = 0, count: int = 0, **args):
  88     result = send_gdb_with_response(
  89         lambda: _variables(variablesReference, start, count)
  90     )
  91     return {"variables": result}