Current File : //usr/share/gdb/python/gdb/dap/evaluate.py
# Copyright 2022-2024 Free Software Foundation, Inc.
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
# This is deprecated in 3.9, but required in older versions.
from typing import Optional
import gdb
from .frames import select_frame
from .server import capability, client_bool_capability, request
from .startup import DAPException, in_gdb_thread, parse_and_eval
from .varref import VariableReference, apply_format, find_variable
class EvaluateResult(VariableReference):
def __init__(self, value):
super().__init__(None, value, "result")
# Helper function to evaluate an expression in a certain frame.
@in_gdb_thread
def _evaluate(expr, frame_id, value_format):
with apply_format(value_format):
global_context = True
if frame_id is not None:
select_frame(frame_id)
global_context = False
val = parse_and_eval(expr, global_context=global_context)
ref = EvaluateResult(val)
return ref.to_object()
# Like _evaluate but ensure that the expression cannot cause side
# effects.
@in_gdb_thread
def _eval_for_hover(expr, frame_id, value_format):
with gdb.with_parameter("may-write-registers", "off"):
with gdb.with_parameter("may-write-memory", "off"):
with gdb.with_parameter("may-call-functions", "off"):
return _evaluate(expr, frame_id, value_format)
class _SetResult(VariableReference):
def __init__(self, value):
super().__init__(None, value, "value")
# Helper function to evaluate a gdb command in a certain frame.
@in_gdb_thread
def _repl(command, frame_id):
if frame_id is not None:
select_frame(frame_id)
val = gdb.execute(command, from_tty=True, to_string=True)
return {
"result": val,
"variablesReference": 0,
}
@request("evaluate")
@capability("supportsEvaluateForHovers")
@capability("supportsValueFormattingOptions")
def eval_request(
*,
expression: str,
frameId: Optional[int] = None,
context: str = "variables",
format=None,
**args,
):
if context in ("watch", "variables"):
# These seem to be expression-like.
return _evaluate(expression, frameId, format)
elif context == "hover":
return _eval_for_hover(expression, frameId, format)
elif context == "repl":
# Ignore the format for repl evaluation.
return _repl(expression, frameId)
else:
raise DAPException('unknown evaluate context "' + context + '"')
@request("variables")
# Note that we ignore the 'filter' field. That seems to be
# specific to javascript.
def variables(
*, variablesReference: int, start: int = 0, count: int = 0, format=None, **args
):
# This behavior was clarified here:
# https://github.com/microsoft/debug-adapter-protocol/pull/394
if not client_bool_capability("supportsVariablePaging"):
start = 0
count = 0
with apply_format(format):
var = find_variable(variablesReference)
children = var.fetch_children(start, count)
return {"variables": [x.to_object() for x in children]}
@capability("supportsSetExpression")
@request("setExpression")
def set_expression(
*, expression: str, value: str, frameId: Optional[int] = None, format=None, **args
):
with apply_format(format):
global_context = True
if frameId is not None:
select_frame(frameId)
global_context = False
lhs = parse_and_eval(expression, global_context=global_context)
rhs = parse_and_eval(value, global_context=global_context)
lhs.assign(rhs)
return _SetResult(lhs).to_object()
@capability("supportsSetVariable")
@request("setVariable")
def set_variable(
*, variablesReference: int, name: str, value: str, format=None, **args
):
with apply_format(format):
var = find_variable(variablesReference)
lhs = var.find_child_by_name(name)
rhs = parse_and_eval(value)
lhs.assign(rhs)
return lhs.to_object()
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