1#!/usr/bin/env python3
2#
3# Copyright (C) 2016 The Android Open Source Project
4#
5# Licensed under the Apache License, Version 2.0 (the "License");
6# you may not use this file except in compliance with the License.
7# You may obtain a copy of the License at
8#
9#   http://www.apache.org/licenses/LICENSE-2.0
10#
11# Unless required by applicable law or agreed to in writing, software
12# distributed under the License is distributed on an "AS IS" BASIS,
13# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14# See the License for the specific language governing permissions and
15# limitations under the License.
16
17"""Performs bisection bug search on methods and optimizations.
18
19See README.md.
20
21Example usage:
22./bisection-search.py -cp classes.dex --expected-output output Test
23"""
24
25import abc
26import argparse
27import os
28import re
29import shlex
30import sys
31
32from subprocess import call
33from tempfile import NamedTemporaryFile
34
35sys.path.append(os.path.dirname(os.path.dirname(
36        os.path.realpath(__file__))))
37
38from common.common import DeviceTestEnv
39from common.common import FatalError
40from common.common import GetEnvVariableOrError
41from common.common import HostTestEnv
42from common.common import LogSeverity
43from common.common import RetCode
44
45
46# Passes that are never disabled during search process because disabling them
47# would compromise correctness.
48MANDATORY_PASSES = ['dex_cache_array_fixups_arm',
49                    'dex_cache_array_fixups_mips',
50                    'instruction_simplifier$before_codegen',
51                    'pc_relative_fixups_x86',
52                    'pc_relative_fixups_mips',
53                    'x86_memory_operand_generation']
54
55# Passes that show up as optimizations in compiler verbose output but aren't
56# driven by run-passes mechanism. They are mandatory and will always run, we
57# never pass them to --run-passes.
58NON_PASSES = ['builder', 'prepare_for_register_allocation',
59              'liveness', 'register']
60
61# If present in raw cmd, this tag will be replaced with runtime arguments
62# controlling the bisection search. Otherwise arguments will be placed on second
63# position in the command.
64RAW_CMD_RUNTIME_ARGS_TAG = '{ARGS}'
65
66# Default core image path relative to ANDROID_HOST_OUT.
67DEFAULT_IMAGE_RELATIVE_PATH = '/framework/core.art'
68
69class Dex2OatWrapperTestable(object):
70  """Class representing a testable compilation.
71
72  Accepts filters on compiled methods and optimization passes.
73  """
74
75  def __init__(self, base_cmd, test_env, expected_retcode=None,
76               output_checker=None, verbose=False):
77    """Constructor.
78
79    Args:
80      base_cmd: list of strings, base command to run.
81      test_env: ITestEnv.
82      expected_retcode: RetCode, expected normalized return code.
83      output_checker: IOutputCheck, output checker.
84      verbose: bool, enable verbose output.
85    """
86    self._base_cmd = base_cmd
87    self._test_env = test_env
88    self._expected_retcode = expected_retcode
89    self._output_checker = output_checker
90    self._compiled_methods_path = self._test_env.CreateFile('compiled_methods')
91    self._passes_to_run_path = self._test_env.CreateFile('run_passes')
92    self._verbose = verbose
93    if RAW_CMD_RUNTIME_ARGS_TAG in self._base_cmd:
94      self._arguments_position = self._base_cmd.index(RAW_CMD_RUNTIME_ARGS_TAG)
95      self._base_cmd.pop(self._arguments_position)
96    else:
97      self._arguments_position = 1
98
99  def Test(self, compiled_methods, passes_to_run=None):
100    """Tests compilation with compiled_methods and run_passes switches active.
101
102    If compiled_methods is None then compiles all methods.
103    If passes_to_run is None then runs default passes.
104
105    Args:
106      compiled_methods: list of strings representing methods to compile or None.
107      passes_to_run: list of strings representing passes to run or None.
108
109    Returns:
110      True if test passes with given settings. False otherwise.
111    """
112    if self._verbose:
113      print('Testing methods: {0} passes: {1}.'.format(
114          compiled_methods, passes_to_run))
115    cmd = self._PrepareCmd(compiled_methods=compiled_methods,
116                           passes_to_run=passes_to_run)
117    (output, ret_code) = self._test_env.RunCommand(
118        cmd, LogSeverity.ERROR)
119    res = True
120    if self._expected_retcode:
121      res = self._expected_retcode == ret_code
122    if self._output_checker:
123      res = res and self._output_checker.Check(output)
124    if self._verbose:
125      print('Test passed: {0}.'.format(res))
126    return res
127
128  def GetAllMethods(self):
129    """Get methods compiled during the test.
130
131    Returns:
132      List of strings representing methods compiled during the test.
133
134    Raises:
135      FatalError: An error occurred when retrieving methods list.
136    """
137    cmd = self._PrepareCmd()
138    (output, _) = self._test_env.RunCommand(cmd, LogSeverity.INFO)
139    match_methods = re.findall(r'Building ([^\n]+)\n', output)
140    if not match_methods:
141      raise FatalError('Failed to retrieve methods list. '
142                       'Not recognized output format.')
143    return match_methods
144
145  def GetAllPassesForMethod(self, compiled_method):
146    """Get all optimization passes ran for a method during the test.
147
148    Args:
149      compiled_method: string representing method to compile.
150
151    Returns:
152      List of strings representing passes ran for compiled_method during test.
153
154    Raises:
155      FatalError: An error occurred when retrieving passes list.
156    """
157    cmd = self._PrepareCmd(compiled_methods=[compiled_method])
158    (output, _) = self._test_env.RunCommand(cmd, LogSeverity.INFO)
159    match_passes = re.findall(r'Starting pass: ([^\n]+)\n', output)
160    if not match_passes:
161      raise FatalError('Failed to retrieve passes list. '
162                       'Not recognized output format.')
163    return [p for p in match_passes if p not in NON_PASSES]
164
165  def _PrepareCmd(self, compiled_methods=None, passes_to_run=None):
166    """Prepare command to run."""
167    cmd = self._base_cmd[0:self._arguments_position]
168    # insert additional arguments before the first argument
169    if passes_to_run is not None:
170      self._test_env.WriteLines(self._passes_to_run_path, passes_to_run)
171      cmd += ['-Xcompiler-option', '--run-passes={0}'.format(
172          self._passes_to_run_path)]
173    cmd += ['-Xcompiler-option', '--runtime-arg', '-Xcompiler-option',
174            '-verbose:compiler', '-Xcompiler-option', '-j1']
175    cmd += self._base_cmd[self._arguments_position:]
176    return cmd
177
178
179class IOutputCheck(object):
180  """Abstract output checking class.
181
182  Checks if output is correct.
183  """
184  __meta_class__ = abc.ABCMeta
185
186  @abc.abstractmethod
187  def Check(self, output):
188    """Check if output is correct.
189
190    Args:
191      output: string, output to check.
192
193    Returns:
194      boolean, True if output is correct, False otherwise.
195    """
196
197
198class EqualsOutputCheck(IOutputCheck):
199  """Concrete output checking class checking for equality to expected output."""
200
201  def __init__(self, expected_output):
202    """Constructor.
203
204    Args:
205      expected_output: string, expected output.
206    """
207    self._expected_output = expected_output
208
209  def Check(self, output):
210    """See base class."""
211    return self._expected_output == output
212
213
214class ExternalScriptOutputCheck(IOutputCheck):
215  """Concrete output checking class calling an external script.
216
217  The script should accept two arguments, path to expected output and path to
218  program output. It should exit with 0 return code if outputs are equivalent
219  and with different return code otherwise.
220  """
221
222  def __init__(self, script_path, expected_output_path, logfile):
223    """Constructor.
224
225    Args:
226      script_path: string, path to checking script.
227      expected_output_path: string, path to file with expected output.
228      logfile: file handle, logfile.
229    """
230    self._script_path = script_path
231    self._expected_output_path = expected_output_path
232    self._logfile = logfile
233
234  def Check(self, output):
235    """See base class."""
236    ret_code = None
237    with NamedTemporaryFile(mode='w', delete=False) as temp_file:
238      temp_file.write(output)
239      temp_file.flush()
240      ret_code = call(
241          [self._script_path, self._expected_output_path, temp_file.name],
242          stdout=self._logfile, stderr=self._logfile, universal_newlines=True)
243    return ret_code == 0
244
245
246def BinarySearch(start, end, test):
247  """Binary search integers using test function to guide the process."""
248  while start < end:
249    mid = (start + end) // 2
250    if test(mid):
251      start = mid + 1
252    else:
253      end = mid
254  return start
255
256
257def FilterPasses(passes, cutoff_idx):
258  """Filters passes list according to cutoff_idx but keeps mandatory passes."""
259  return [opt_pass for idx, opt_pass in enumerate(passes)
260          if opt_pass in MANDATORY_PASSES or idx < cutoff_idx]
261
262
263def BugSearch(testable):
264  """Find buggy (method, optimization pass) pair for a given testable.
265
266  Args:
267    testable: Dex2OatWrapperTestable.
268
269  Returns:
270    (string, string) tuple. First element is name of method which when compiled
271    exposes test failure. Second element is name of optimization pass such that
272    for aforementioned method running all passes up to and excluding the pass
273    results in test passing but running all passes up to and including the pass
274    results in test failing.
275
276    (None, None) if test passes when compiling all methods.
277    (string, None) if a method is found which exposes the failure, but the
278      failure happens even when running just mandatory passes.
279
280  Raises:
281    FatalError: Testable fails with no methods compiled.
282    AssertionError: Method failed for all passes when bisecting methods, but
283    passed when bisecting passes. Possible sporadic failure.
284  """
285  all_methods = testable.GetAllMethods()
286  faulty_method_idx = BinarySearch(
287      0,
288      len(all_methods) + 1,
289      lambda mid: testable.Test(all_methods[0:mid]))
290  if faulty_method_idx == len(all_methods) + 1:
291    return (None, None)
292  if faulty_method_idx == 0:
293    raise FatalError('Testable fails with no methods compiled.')
294  faulty_method = all_methods[faulty_method_idx - 1]
295  all_passes = testable.GetAllPassesForMethod(faulty_method)
296  faulty_pass_idx = BinarySearch(
297      0,
298      len(all_passes) + 1,
299      lambda mid: testable.Test([faulty_method],
300                                FilterPasses(all_passes, mid)))
301  if faulty_pass_idx == 0:
302    return (faulty_method, None)
303  assert faulty_pass_idx != len(all_passes) + 1, ('Method must fail for some '
304                                                  'passes.')
305  faulty_pass = all_passes[faulty_pass_idx - 1]
306  return (faulty_method, faulty_pass)
307
308
309def PrepareParser():
310  """Prepares argument parser."""
311  parser = argparse.ArgumentParser(
312      description='Tool for finding compiler bugs. Either --raw-cmd or both '
313                  '-cp and --class are required.')
314  command_opts = parser.add_argument_group('dalvikvm command options')
315  command_opts.add_argument('-cp', '--classpath', type=str, help='classpath')
316  command_opts.add_argument('--class', dest='classname', type=str,
317                            help='name of main class')
318  command_opts.add_argument('--lib', type=str, default='libart.so',
319                            help='lib to use, default: libart.so')
320  command_opts.add_argument('--dalvikvm-option', dest='dalvikvm_opts',
321                            metavar='OPT', nargs='*', default=[],
322                            help='additional dalvikvm option')
323  command_opts.add_argument('--arg', dest='test_args', nargs='*', default=[],
324                            metavar='ARG', help='argument passed to test')
325  command_opts.add_argument('--image', type=str, help='path to image')
326  command_opts.add_argument('--raw-cmd', type=str,
327                            help='bisect with this command, ignore other '
328                                 'command options')
329  bisection_opts = parser.add_argument_group('bisection options')
330  bisection_opts.add_argument('--64', dest='x64', action='store_true',
331                              default=False, help='x64 mode')
332  bisection_opts.add_argument(
333      '--device', action='store_true', default=False, help='run on device')
334  bisection_opts.add_argument(
335      '--device-serial', help='device serial number, implies --device')
336  bisection_opts.add_argument('--expected-output', type=str,
337                              help='file containing expected output')
338  bisection_opts.add_argument(
339      '--expected-retcode', type=str, help='expected normalized return code',
340      choices=[RetCode.SUCCESS.name, RetCode.TIMEOUT.name, RetCode.ERROR.name])
341  bisection_opts.add_argument(
342      '--check-script', type=str,
343      help='script comparing output and expected output')
344  bisection_opts.add_argument(
345      '--logfile', type=str, help='custom logfile location')
346  bisection_opts.add_argument('--cleanup', action='store_true',
347                              default=False, help='clean up after bisecting')
348  bisection_opts.add_argument('--timeout', type=int, default=60,
349                              help='if timeout seconds pass assume test failed')
350  bisection_opts.add_argument('--verbose', action='store_true',
351                              default=False, help='enable verbose output')
352  return parser
353
354
355def PrepareBaseCommand(args, classpath):
356  """Prepares base command used to run test."""
357  if args.raw_cmd:
358    return shlex.split(args.raw_cmd)
359  else:
360    base_cmd = ['dalvikvm64'] if args.x64 else ['dalvikvm32']
361    if not args.device:
362      base_cmd += ['-XXlib:{0}'.format(args.lib)]
363      if not args.image:
364        image_path = (GetEnvVariableOrError('ANDROID_HOST_OUT') +
365                      DEFAULT_IMAGE_RELATIVE_PATH)
366      else:
367        image_path = args.image
368      base_cmd += ['-Ximage:{0}'.format(image_path)]
369    if args.dalvikvm_opts:
370      base_cmd += args.dalvikvm_opts
371    base_cmd += ['-cp', classpath, args.classname] + args.test_args
372  return base_cmd
373
374
375def main():
376  # Parse arguments
377  parser = PrepareParser()
378  args = parser.parse_args()
379  if not args.raw_cmd and (not args.classpath or not args.classname):
380    parser.error('Either --raw-cmd or both -cp and --class are required')
381  if args.device_serial:
382    args.device = True
383  if args.expected_retcode:
384    args.expected_retcode = RetCode[args.expected_retcode]
385  if not args.expected_retcode and not args.check_script:
386    args.expected_retcode = RetCode.SUCCESS
387
388  # Prepare environment
389  classpath = args.classpath
390  if args.device:
391    test_env = DeviceTestEnv(
392        'bisection_search_', args.cleanup, args.logfile, args.timeout,
393        args.device_serial)
394    if classpath:
395      classpath = test_env.PushClasspath(classpath)
396  else:
397    test_env = HostTestEnv(
398        'bisection_search_', args.cleanup, args.logfile, args.timeout, args.x64)
399  base_cmd = PrepareBaseCommand(args, classpath)
400  output_checker = None
401  if args.expected_output:
402    if args.check_script:
403      output_checker = ExternalScriptOutputCheck(
404          args.check_script, args.expected_output, test_env.logfile)
405    else:
406      with open(args.expected_output, 'r') as expected_output_file:
407        output_checker = EqualsOutputCheck(expected_output_file.read())
408
409  # Perform the search
410  try:
411    testable = Dex2OatWrapperTestable(base_cmd, test_env, args.expected_retcode,
412                                      output_checker, args.verbose)
413    if testable.Test(compiled_methods=[]):
414      (method, opt_pass) = BugSearch(testable)
415    else:
416      print('Testable fails with no methods compiled.')
417      sys.exit(1)
418  except Exception as e:
419    print('Error occurred.\nLogfile: {0}'.format(test_env.logfile.name))
420    test_env.logfile.write('Exception: {0}\n'.format(e))
421    raise
422
423  # Report results
424  if method is None:
425    print('Couldn\'t find any bugs.')
426  elif opt_pass is None:
427    print('Faulty method: {0}. Fails with just mandatory passes.'.format(
428        method))
429  else:
430    print('Faulty method and pass: {0}, {1}.'.format(method, opt_pass))
431  print('Logfile: {0}'.format(test_env.logfile.name))
432  sys.exit(0)
433
434
435if __name__ == '__main__':
436  main()
437