# 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 import sys import os import platform from dex.debugger.DebuggerBase import DebuggerBase, watch_is_active from dex.dextIR import FrameIR, LocIR, StepIR, StopReason, ValueIR from dex.dextIR import ProgramState, StackFrame, SourceLocation from dex.utils.Exceptions import DebuggerException, LoadDebuggerException from dex.utils.ReturnCode import ReturnCode if platform.system() == "Windows": # Don't load on linux; _load_interface will croak before any names are used. from . import setup from . import probe_process from . import breakpoint class DbgEng(DebuggerBase): def __init__(self, context, *args): self.breakpoints = [] self.running = False self.finished = False self.step_info = None super(DbgEng, self).__init__(context, *args) def _custom_init(self): try: res = setup.setup_everything(self.context.options.executable) self.client = res self.running = True except Exception as e: raise Exception('Failed to start debuggee: {}'.format(e)) def _custom_exit(self): setup.cleanup(self.client) def _load_interface(self): arch = platform.architecture()[0] machine = platform.machine() if arch == '32bit' and machine == 'AMD64': # This python process is 32 bits, but is sitting on a 64 bit machine. # Bad things may happen, don't support it. raise LoadDebuggerException('Can\'t run Dexter dbgeng on 32 bit python in a 64 bit environment') if platform.system() != 'Windows': raise LoadDebuggerException('DbgEng supports Windows only') # Otherwise, everything was imported earlier @classmethod def get_name(cls): return 'dbgeng' @classmethod def get_option_name(cls): return 'dbgeng' @property def frames_below_main(self): return [] @property def version(self): # I don't believe there's a well defined DbgEng version, outside of the # version of Windows being used. return "1" def clear_breakpoints(self): for x in self.breakpoints: x.RemoveFlags(breakpoint.BreakpointFlags.DEBUG_BREAKPOINT_ENABLED) self.client.Control.RemoveBreakpoint(x) def _add_breakpoint(self, file_, line): # Breakpoint setting/deleting is not supported by dbgeng at this moment # but is something that should be considered in the future. # TODO: this method is called in the DefaultController but has no effect. pass def _add_conditional_breakpoint(self, file_, line, condition): # breakpoint setting/deleting is not supported by dbgeng at this moment # but is something that should be considered in the future. raise NotImplementedError('add_conditional_breakpoint is not yet implemented by dbgeng') def get_triggered_breakpoint_ids(self): raise NotImplementedError('get_triggered_breakpoint_ids is not yet implemented by dbgeng') def delete_breakpoint(self, id): # breakpoint setting/deleting is not supported by dbgeng at this moment # but is something that should be considered in the future. raise NotImplementedError('delete_conditional_breakpoint is not yet implemented by dbgeng') def launch(self): # We are, by this point, already launched. self.step_info = probe_process.probe_state(self.client) def step(self): res = setup.step_once(self.client) if not res: self.finished = True self.step_info = res def go(self): # FIXME: running freely doesn't seem to reliably stop when back in a # relevant source file -- this is likely to be a problem when setting # breakpoints. Until that's fixed, single step instead of running # freely. This isn't very efficient, but at least makes progress. self.step() def _get_step_info(self, watches, step_index): frames = self.step_info state_frames = [] # For now assume the base function is the... function, ignoring # inlining. dex_frames = [] for i, x in enumerate(frames): # XXX Might be able to get columns out through # GetSourceEntriesByOffset, not a priority now loc = LocIR(path=x.source_file, lineno=x.line_no, column=0) new_frame = FrameIR(function=x.function_name, is_inlined=False, loc=loc) dex_frames.append(new_frame) state_frame = StackFrame(function=new_frame.function, is_inlined=new_frame.is_inlined, location=SourceLocation(path=x.source_file, lineno=x.line_no, column=0), watches={}) for expr in map( # Filter out watches that are not active in the current frame, # and then evaluate all the active watches. lambda watch_info, idx=i: self.evaluate_expression(watch_info.expression, idx), filter( lambda watch_info, idx=i, line_no=loc.lineno, path=loc.path: watch_is_active(watch_info, path, idx, line_no), watches)): state_frame.watches[expr.expression] = expr state_frames.append(state_frame) return StepIR( step_index=step_index, frames=dex_frames, stop_reason=StopReason.STEP, program_state=ProgramState(state_frames)) @property def is_running(self): return False # We're never free-running @property def is_finished(self): return self.finished def evaluate_expression(self, expression, frame_idx=0): # XXX: cdb insists on using '->' to examine fields of structures, # as it appears to reserve '.' for other purposes. fixed_expr = expression.replace('.', '->') orig_scope_idx = self.client.Symbols.GetCurrentScopeFrameIndex() self.client.Symbols.SetScopeFrameByIndex(frame_idx) res = self.client.Control.Evaluate(fixed_expr) if res is not None: result, typename = self.client.Control.Evaluate(fixed_expr) could_eval = True else: result, typename = (None, None) could_eval = False self.client.Symbols.SetScopeFrameByIndex(orig_scope_idx) return ValueIR( expression=expression, value=str(result), type_name=typename, error_string="", could_evaluate=could_eval, is_optimized_away=False, is_irretrievable=not could_eval)