# DExTer : Debugging Experience Tester
# ~~~~~~ ~ ~~ ~ ~~
#
# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
# See https://llvm.org/LICENSE.txt for license information.
# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
"""Interface for communicating with the Visual Studio debugger via DTE."""
import abc
import imp
import os
import sys
from enum import IntEnum
from pathlib import PurePath, Path
from collections import defaultdict, namedtuple
from dex.command.CommandBase import StepExpectInfo
from dex.debugger.DebuggerBase import DebuggerBase, watch_is_active
from dex.dextIR import FrameIR, LocIR, StepIR, StopReason, ValueIR
from dex.dextIR import StackFrame, SourceLocation, ProgramState
from dex.utils.Exceptions import Error, LoadDebuggerException
from dex.utils.ReturnCode import ReturnCode
def _load_com_module():
try:
module_info = imp.find_module(
"ComInterface", [os.path.join(os.path.dirname(__file__), "windows")]
)
return imp.load_module("ComInterface", *module_info)
except ImportError as e:
raise LoadDebuggerException(e, sys.exc_info())
# VSBreakpoint(path: PurePath, line: int, col: int, cond: str). This is enough
# info to identify breakpoint equivalence in visual studio based on the
# properties we set through dexter currently.
VSBreakpoint = namedtuple("VSBreakpoint", "path, line, col, cond")
# Visual Studio events.
# https://learn.microsoft.com/en-us/dotnet/api/envdte.dbgeventreason?view=visualstudiosdk-2022
class DbgEvent(IntEnum):
dbgEventReasonNone = 1
dbgEventReasonGo = 2
dbgEventReasonAttachProgram = 3
dbgEventReasonDetachProgram = 4
dbgEventReasonLaunchProgram = 5
dbgEventReasonEndProgram = 6
dbgEventReasonStopDebugging = 7
dbgEventReasonStep = 8
dbgEventReasonBreakpoint = 9
dbgEventReasonExceptionThrown = 10
dbgEventReasonExceptionNotHandled = 11
dbgEventReasonUserBreak = 12
dbgEventReasonContextSwitch = 13
first = dbgEventReasonNone
last = dbgEventReasonContextSwitch
class VisualStudio(
DebuggerBase, metaclass=abc.ABCMeta
): # pylint: disable=abstract-method
# Constants for results of Debugger.CurrentMode
# (https://msdn.microsoft.com/en-us/library/envdte.debugger.currentmode.aspx)
dbgDesignMode = 1
dbgBreakMode = 2
dbgRunMode = 3
def __init__(self, *args):
self.com_module = None
self._debugger = None
self._solution = None
self._fn_step = None
self._fn_go = None
# The next available unique breakpoint id. Use self._get_next_id().
self._next_bp_id = 0
# VisualStudio appears to common identical breakpoints. That is, if you
# ask for a breakpoint that already exists the Breakpoints list will
# not grow. DebuggerBase requires all breakpoints have a unique id,
# even for duplicates, so we'll need to do some bookkeeping. Map
# {VSBreakpoint: list(id)} where id is the unique dexter-side id for
# the requested breakpoint.
self._vs_to_dex_ids = defaultdict(list)
# Map {id: VSBreakpoint} where id is unique and VSBreakpoint identifies
# a breakpoint in Visual Studio. There may be many ids mapped to a
# single VSBreakpoint. Use self._vs_to_dex_ids to find (dexter)
# breakpoints mapped to the same visual studio breakpoint.
self._dex_id_to_vs = {}
super(VisualStudio, self).__init__(*args)
def _create_solution(self):
self._solution.Create(self.context.working_directory.path, "DexterSolution")
try:
self._solution.AddFromFile(self._project_file)
except OSError:
raise LoadDebuggerException(
"could not debug the specified executable", sys.exc_info()
)
def _load_solution(self):
try:
self._solution.Open(self.context.options.vs_solution)
except:
raise LoadDebuggerException(
"could not load specified vs solution at {}".format(
self.context.options.vs_solution
),
sys.exc_info(),
)
def _custom_init(self):
try:
self._debugger = self._interface.Debugger
self._debugger.HexDisplayMode = False
self._interface.MainWindow.Visible = self.context.options.show_debugger
self._solution = self._interface.Solution
if self.context.options.vs_solution is None:
self._create_solution()
else:
self._load_solution()
self._fn_step = self._debugger.StepInto
self._fn_go = self._debugger.Go
except AttributeError as e:
raise LoadDebuggerException(str(e), sys.exc_info())
def _custom_exit(self):
if self._interface:
self._interface.Quit()
@property
def _project_file(self):
return self.context.options.executable
@abc.abstractproperty
def _dte_version(self):
pass
@property
def _location(self):
# TODO: Find a better way of determining path, line and column info
# that doesn't require reading break points. This method requires
# all lines to have a break point on them.
bp = self._debugger.BreakpointLastHit
return {
"path": getattr(bp, "File", None),
"lineno": getattr(bp, "FileLine", None),
"column": getattr(bp, "FileColumn", None),
}
@property
def _mode(self):
return self._debugger.CurrentMode
def _load_interface(self):
self.com_module = _load_com_module()
return self.com_module.DTE(self._dte_version)
@property
def version(self):
try:
return self._interface.Version
except AttributeError:
return None
def clear_breakpoints(self):
for bp in self._debugger.Breakpoints:
bp.Delete()
self._vs_to_dex_ids.clear()
self._dex_id_to_vs.clear()
def _add_breakpoint(self, file_, line):
return self._add_conditional_breakpoint(file_, line, "")
def _get_next_id(self):
# "Generate" a new unique id for the breakpoint.
id = self._next_bp_id
self._next_bp_id += 1
return id
def _add_conditional_breakpoint(self, file_, line, condition):
col = 1
vsbp = VSBreakpoint(PurePath(file_), line, col, condition)
new_id = self._get_next_id()
# Do we have an exact matching breakpoint already?
if vsbp in self._vs_to_dex_ids:
self._vs_to_dex_ids[vsbp].append(new_id)
self._dex_id_to_vs[new_id] = vsbp
return new_id
# Breakpoint doesn't exist already. Add it now.
count_before = self._debugger.Breakpoints.Count
self._debugger.Breakpoints.Add("", file_, line, col, condition)
# Our internal representation of VS says that the breakpoint doesn't
# already exist so we do not expect this operation to fail here.
assert count_before < self._debugger.Breakpoints.Count
# We've added a new breakpoint, record its id.
self._vs_to_dex_ids[vsbp].append(new_id)
self._dex_id_to_vs[new_id] = vsbp
return new_id
def get_triggered_breakpoint_ids(self):
"""Returns a set of opaque ids for just-triggered breakpoints."""
bps_hit = self._debugger.AllBreakpointsLastHit
bp_id_list = []
# Intuitively, AllBreakpointsLastHit breakpoints are the last hit
# _bound_ breakpoints. A bound breakpoint's parent holds the info of
# the breakpoint the user requested. Our internal state tracks the user
# requested breakpoints so we look at the Parent of these triggered
# breakpoints to determine which have been hit.
for bp in bps_hit:
# All bound breakpoints should have the user-defined breakpoint as
# a parent.
assert bp.Parent
vsbp = VSBreakpoint(
PurePath(bp.Parent.File),
bp.Parent.FileLine,
bp.Parent.FileColumn,
bp.Parent.Condition,
)
try:
ids = self._vs_to_dex_ids[vsbp]
except KeyError:
pass
else:
bp_id_list += ids
return set(bp_id_list)
def delete_breakpoints(self, ids):
"""Delete breakpoints by their ids.
Raises a KeyError if no breakpoint with this id exists.
"""
vsbp_set = set()
for id in ids:
vsbp = self._dex_id_to_vs[id]
# Remove our id from the associated list of dex ids.
self._vs_to_dex_ids[vsbp].remove(id)
del self._dex_id_to_vs[id]
# Bail if there are other uses of this vsbp.
if len(self._vs_to_dex_ids[vsbp]) > 0:
continue
# Otherwise find and delete it.
vsbp_set.add(vsbp)
vsbp_to_del_count = len(vsbp_set)
for bp in self._debugger.Breakpoints:
# We're looking at the user-set breakpoints so there should be no
# Parent.
assert bp.Parent == None
this_vsbp = VSBreakpoint(
PurePath(bp.File), bp.FileLine, bp.FileColumn, bp.Condition
)
if this_vsbp in vsbp_set:
bp.Delete()
vsbp_to_del_count -= 1
if vsbp_to_del_count == 0:
break
if vsbp_to_del_count:
raise KeyError("did not find breakpoint to be deleted")
def _fetch_property(self, props, name):
num_props = props.Count
result = None
for x in range(1, num_props + 1):
item = props.Item(x)
if item.Name == name:
return item
assert False, "Couldn't find property {}".format(name)
def launch(self, cmdline):
exe_path = Path(self.context.options.executable)
self.context.logger.note(f"VS: Using executable: '{exe_path}'")
cmdline_str = " ".join(cmdline)
if self.context.options.target_run_args:
cmdline_str += f" {self.context.options.target_run_args}"
if cmdline_str:
self.context.logger.note(f"VS: Using executable args: '{cmdline_str}'")
# In a slightly baroque manner, lookup the VS project that runs when
# you click "run", and set its command line options to the desired
# command line options.
startup_proj_name = str(
self._fetch_property(self._interface.Solution.Properties, "StartupProject")
)
project = self._fetch_property(self._interface.Solution, startup_proj_name)
ActiveConfiguration = self._fetch_property(
project.Properties, "ActiveConfiguration"
).Object
ActiveConfiguration.DebugSettings.CommandArguments = cmdline_str
ConfigurationName = ActiveConfiguration.ConfigurationName
SolConfig = self._fetch_property(
self._interface.Solution.SolutionBuild.SolutionConfigurations,
ConfigurationName,
)
for Context in SolConfig.SolutionContexts:
Context.ShouldBuild = False
self.context.logger.note("Launching VS debugger...")
self._fn_go(False)
def step(self):
self._fn_step(False)
def go(self) -> ReturnCode:
self._fn_go(False)
return ReturnCode.OK
def set_current_stack_frame(self, idx: int = 0):
thread = self._debugger.CurrentThread
stack_frames = thread.StackFrames
try:
stack_frame = stack_frames[idx]
self._debugger.CurrentStackFrame = stack_frame.raw
except IndexError:
raise Error(
"attempted to access stack frame {} out of {}".format(
idx, len(stack_frames)
)
)
def _translate_stop_reason(self, reason):
if reason == DbgEvent.dbgEventReasonNone:
return None
if reason == DbgEvent.dbgEventReasonBreakpoint:
return StopReason.BREAKPOINT
if reason == DbgEvent.dbgEventReasonStep:
return StopReason.STEP
if reason == DbgEvent.dbgEventReasonEndProgram:
return StopReason.PROGRAM_EXIT
if reason == DbgEvent.dbgEventReasonExceptionNotHandled:
return StopReason.ERROR
assert reason <= DbgEvent.last and reason >= DbgEvent.first
return StopReason.OTHER
def _get_step_info(self, watches, step_index):
thread = self._debugger.CurrentThread
stackframes = thread.StackFrames
frames = []
state_frames = []
loc = LocIR(**self._location)
valid_loc_for_watch = loc.path and os.path.exists(loc.path)
for idx, sf in enumerate(stackframes):
frame = FrameIR(
function=self._sanitize_function_name(sf.FunctionName),
is_inlined=sf.FunctionName.startswith("[Inline Frame]"),
loc=LocIR(path=None, lineno=None, column=None),
)
fname = frame.function or "" # pylint: disable=no-member
if any(name in fname for name in self.frames_below_main):
break
state_frame = StackFrame(
function=frame.function, is_inlined=frame.is_inlined, watches={}
)
if valid_loc_for_watch and idx == 0:
for watch_info in watches:
if watch_is_active(watch_info, loc.path, idx, loc.lineno):
watch_expr = watch_info.expression
state_frame.watches[watch_expr] = self.evaluate_expression(
watch_expr, idx
)
state_frames.append(state_frame)
frames.append(frame)
if frames:
frames[0].loc = loc
state_frames[0].location = SourceLocation(**self._location)
stop_reason = self._translate_stop_reason(self._debugger.LastBreakReason)
program_state = ProgramState(frames=state_frames)
return StepIR(
step_index=step_index,
frames=frames,
stop_reason=stop_reason,
program_state=program_state,
)
@property
def is_running(self):
return self._mode == VisualStudio.dbgRunMode
@property
def is_finished(self):
return self._mode == VisualStudio.dbgDesignMode
@property
def frames_below_main(self):
return [
"[Inline Frame] invoke_main",
"__scrt_common_main_seh",
"__tmainCRTStartup",
"mainCRTStartup",
]
def evaluate_expression(self, expression, frame_idx=0) -> ValueIR:
if frame_idx != 0:
self.set_current_stack_frame(frame_idx)
result = self._debugger.GetExpression(expression)
if frame_idx != 0:
self.set_current_stack_frame(0)
value = result.Value
is_optimized_away = any(
s in value
for s in [
"Variable is optimized away and not available",
"Value is not available, possibly due to optimization",
]
)
is_irretrievable = any(
s in value
for s in [
"???",
"<Unable to read memory>",
]
)
# an optimized away value is still counted as being able to be
# evaluated.
could_evaluate = result.IsValidValue or is_optimized_away or is_irretrievable
return ValueIR(
expression=expression,
value=value,
type_name=result.Type,
error_string=None,
is_optimized_away=is_optimized_away,
could_evaluate=could_evaluate,
is_irretrievable=is_irretrievable,
)
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