# 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 """DexExpectWatch base class, holds logic for how to build and process expected watch commands. """ import abc import difflib import os from dex.command.CommandBase import CommandBase from dex.command.StepValueInfo import StepValueInfo class DexExpectWatchBase(CommandBase): def __init__(self, *args, **kwargs): if len(args) < 2: raise TypeError('expected at least two args') self.expression = args[0] self.values = [str(arg) for arg in args[1:]] try: on_line = kwargs.pop('on_line') self._from_line = on_line self._to_line = on_line except KeyError: self._from_line = kwargs.pop('from_line', 1) self._to_line = kwargs.pop('to_line', 999999) self._require_in_order = kwargs.pop('require_in_order', True) if kwargs: raise TypeError('unexpected named args: {}'.format( ', '.join(kwargs))) # Number of times that this watch has been encountered. self.times_encountered = 0 # We'll pop from this set as we encounter values so anything left at # the end can be considered as not having been seen. self._missing_values = set(self.values) self.misordered_watches = [] # List of StepValueInfos for any watch that is encountered as invalid. self.invalid_watches = [] # List of StepValueInfo any any watch where we couldn't retrieve its # data. self.irretrievable_watches = [] # List of StepValueInfos for any watch that is encountered as having # been optimized out. self.optimized_out_watches = [] # List of StepValueInfos for any watch that is encountered that has an # expected value. self.expected_watches = [] # List of StepValueInfos for any watch that is encountered that has an # unexpected value. self.unexpected_watches = [] super(DexExpectWatchBase, self).__init__() def get_watches(self): return [self.expression] @property def line_range(self): return list(range(self._from_line, self._to_line + 1)) @property def missing_values(self): return sorted(list(self._missing_values)) @property def encountered_values(self): return sorted(list(set(self.values) - self._missing_values)) def resolve_label(self, label_line_pair): # from_line and to_line could have the same label. label, lineno = label_line_pair if self._to_line == label: self._to_line = lineno if self._from_line == label: self._from_line = lineno def has_labels(self): return len(self.get_label_args()) > 0 def get_label_args(self): return [label for label in (self._from_line, self._to_line) if isinstance(label, str)] @abc.abstractmethod def _get_expected_field(self, watch): """Return a field from watch that this ExpectWatch command is checking. """ def _handle_watch(self, step_info): self.times_encountered += 1 if not step_info.watch_info.could_evaluate: self.invalid_watches.append(step_info) return if step_info.watch_info.is_optimized_away: self.optimized_out_watches.append(step_info) return if step_info.watch_info.is_irretrievable: self.irretrievable_watches.append(step_info) return if step_info.expected_value not in self.values: self.unexpected_watches.append(step_info) return self.expected_watches.append(step_info) try: self._missing_values.remove(step_info.expected_value) except KeyError: pass def _check_watch_order(self, actual_watches, expected_values): """Use difflib to figure out whether the values are in the expected order or not. """ differences = [] actual_values = [w.expected_value for w in actual_watches] value_differences = list(difflib.Differ().compare(actual_values, expected_values)) missing_value = False index = 0 for vd in value_differences: kind = vd[0] if kind == '+': # A value that is encountered in the expected list but not in the # actual list. We'll keep a note that something is wrong and flag # the next value that matches as misordered. missing_value = True elif kind == ' ': # This value is as expected. It might still be wrong if we've # previously encountered a value that is in the expected list but # not the actual list. if missing_value: missing_value = False differences.append(actual_watches[index]) index += 1 elif kind == '-': # A value that is encountered in the actual list but not the # expected list. differences.append(actual_watches[index]) index += 1 else: assert False, 'unexpected diff:{}'.format(vd) return differences def eval(self, step_collection): for step in step_collection.steps: loc = step.current_location if (loc.path and os.path.exists(loc.path) and os.path.exists(self.path) and os.path.samefile(loc.path, self.path) and loc.lineno in self.line_range): try: watch = step.program_state.frames[0].watches[self.expression] except KeyError: pass else: expected_field = self._get_expected_field(watch) step_info = StepValueInfo(step.step_index, watch, expected_field) self._handle_watch(step_info) if self._require_in_order: # A list of all watches where the value has changed. value_change_watches = [] prev_value = None for watch in self.expected_watches: if watch.expected_value != prev_value: value_change_watches.append(watch) prev_value = watch.expected_value self.misordered_watches = self._check_watch_order( value_change_watches, [ v for v in self.values if v in [w.expected_value for w in self.expected_watches] ])