#!/usr/bin/env python
# Copyright 2016 the V8 project authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""
V8 correctness fuzzer launcher script.
"""

# for py2/py3 compatibility
from __future__ import print_function

import argparse
import hashlib
import itertools
import json
import os
import random
import re
import sys
import traceback

from collections import namedtuple

import v8_commands
import v8_suppressions

PYTHON3 = sys.version_info >= (3, 0)

CONFIGS = dict(
  default=[],
  ignition=[
    '--turbo-filter=~',
    '--noopt',
    '--liftoff',
    '--no-wasm-tier-up',
  ],
  ignition_asm=[
    '--turbo-filter=~',
    '--noopt',
    '--validate-asm',
    '--stress-validate-asm',
  ],
  ignition_eager=[
    '--turbo-filter=~',
    '--noopt',
    '--no-lazy',
    '--no-lazy-inner-functions',
  ],
  ignition_no_ic=[
    '--turbo-filter=~',
    '--noopt',
    '--liftoff',
    '--no-wasm-tier-up',
    '--no-use-ic',
    '--no-lazy-feedback-allocation',
  ],
  ignition_turbo=[],
  ignition_turbo_no_ic=[
    '--no-use-ic',
  ],
  ignition_turbo_opt=[
    '--always-opt',
    '--no-liftoff',
  ],
  ignition_turbo_opt_eager=[
    '--always-opt',
    '--no-lazy',
    '--no-lazy-inner-functions',
  ],
  jitless=[
    '--jitless',
  ],
  slow_path=[
    '--force-slow-path',
  ],
  slow_path_opt=[
    '--always-opt',
    '--force-slow-path',
  ],
  trusted=[
    '--no-untrusted-code-mitigations',
  ],
  trusted_opt=[
    '--always-opt',
    '--no-untrusted-code-mitigations',
  ],
)

# Return codes.
RETURN_PASS = 0
RETURN_FAIL = 2

BASE_PATH = os.path.dirname(os.path.abspath(__file__))
SANITY_CHECKS = os.path.join(BASE_PATH, 'v8_sanity_checks.js')

# Timeout for one d8 run.
SANITY_CHECK_TIMEOUT_SEC = 1
TEST_TIMEOUT_SEC = 3

SUPPORTED_ARCHS = ['ia32', 'x64', 'arm', 'arm64']

# Output for suppressed failure case.
FAILURE_HEADER_TEMPLATE = """#
# V8 correctness failure
# V8 correctness configs: %(configs)s
# V8 correctness sources: %(source_key)s
# V8 correctness suppression: %(suppression)s
"""

# Extended output for failure case. The 'CHECK' is for the minimizer.
FAILURE_TEMPLATE = FAILURE_HEADER_TEMPLATE + """#
# CHECK
#
# Compared %(first_config_label)s with %(second_config_label)s
#
# Flags of %(first_config_label)s:
%(first_config_flags)s
# Flags of %(second_config_label)s:
%(second_config_flags)s
#
# Difference:
%(difference)s%(source_file_text)s
#
### Start of configuration %(first_config_label)s:
%(first_config_output)s
### End of configuration %(first_config_label)s
#
### Start of configuration %(second_config_label)s:
%(second_config_output)s
### End of configuration %(second_config_label)s
"""

SOURCE_FILE_TEMPLATE = """
#
# Source file:
%s"""


FUZZ_TEST_RE = re.compile(r'.*fuzz(-\d+\.js)')
SOURCE_RE = re.compile(r'print\("v8-foozzie source: (.*)"\);')

# The number of hex digits used from the hash of the original source file path.
# Keep the number small to avoid duplicate explosion.
ORIGINAL_SOURCE_HASH_LENGTH = 3

# Placeholder string if no original source file could be determined.
ORIGINAL_SOURCE_DEFAULT = 'none'

# Placeholder string for failures from crash tests. If a failure is found with
# this signature, the matching sources should be moved to the mapping below.
ORIGINAL_SOURCE_CRASHTESTS = 'placeholder for CrashTests'

# Mapping from relative original source path (e.g. CrashTests/path/to/file.js)
# to a string key. Map to the same key for duplicate issues. The key should
# have more than 3 characters to not collide with other existing hashes.
# If a symptom from a particular original source file is known to map to a
# known failure, it can be added to this mapping. This should be done for all
# failures from CrashTests, as those by default map to the placeholder above.
KNOWN_FAILURES = {
  # Foo.caller with asm.js: https://crbug.com/1042556
  'CrashTests/5712410200899584/04483.js': '.caller',
  'CrashTests/5703451898085376/02176.js': '.caller',
  'CrashTests/4846282433495040/04342.js': '.caller',
  # Flaky issue that almost never repros.
  'CrashTests/5694376231632896/1033966.js': 'flaky',
}


def infer_arch(d8):
  """Infer the V8 architecture from the build configuration next to the
  executable.
  """
  with open(os.path.join(os.path.dirname(d8), 'v8_build_config.json')) as f:
    arch = json.load(f)['v8_current_cpu']
  arch = 'ia32' if arch == 'x86' else arch
  assert arch in SUPPORTED_ARCHS
  return arch


class ExecutionArgumentsConfig(object):
  def __init__(self, label):
    self.label = label

  def add_arguments(self, parser, default_config):
    def add_argument(flag_template, help_template, **kwargs):
      parser.add_argument(
          flag_template % self.label,
          help=help_template % self.label,
          **kwargs)

    add_argument(
        '--%s-config',
        '%s configuration',
        default=default_config)
    add_argument(
        '--%s-config-extra-flags',
        'additional flags passed to the %s run',
        action='append',
        default=[])
    add_argument(
        '--%s-d8',
        'optional path to %s d8 executable, '
        'default: bundled in the directory of this script',
        default='d8')

  def make_options(self, options):
    def get(name):
      return getattr(options, '%s_%s' % (self.label, name))

    config = get('config')
    assert config in CONFIGS

    d8 = get('d8')
    if not os.path.isabs(d8):
      d8 = os.path.join(BASE_PATH, d8)
    assert os.path.exists(d8)

    flags = CONFIGS[config] + get('config_extra_flags')

    RunOptions = namedtuple('RunOptions', ['arch', 'config', 'd8', 'flags'])
    return RunOptions(infer_arch(d8), config, d8, flags)


def parse_args():
  first_config_arguments = ExecutionArgumentsConfig('first')
  second_config_arguments = ExecutionArgumentsConfig('second')

  parser = argparse.ArgumentParser()
  parser.add_argument(
    '--random-seed', type=int, required=True,
    help='random seed passed to both runs')
  parser.add_argument(
      '--skip-sanity-checks', default=False, action='store_true',
      help='skip sanity checks for testing purposes')
  parser.add_argument(
      '--skip-suppressions', default=False, action='store_true',
      help='skip suppressions to reproduce known issues')

  # Add arguments for each run configuration.
  first_config_arguments.add_arguments(parser, 'ignition')
  second_config_arguments.add_arguments(parser, 'ignition_turbo')

  parser.add_argument('testcase', help='path to test case')
  options = parser.parse_args()

  # Ensure we have a test case.
  assert (os.path.exists(options.testcase) and
          os.path.isfile(options.testcase)), (
      'Test case %s doesn\'t exist' % options.testcase)

  options.first = first_config_arguments.make_options(options)
  options.second = second_config_arguments.make_options(options)

  # Ensure we make a valid comparison.
  if (options.first.d8 == options.second.d8 and
      options.first.config == options.second.config):
    parser.error('Need either executable or config difference.')

  return options


def get_meta_data(content):
  """Extracts original-source-file paths from test case content."""
  sources = []
  for line in content.splitlines():
    match = SOURCE_RE.match(line)
    if match:
      sources.append(match.group(1))
  return {'sources': sources}


def content_bailout(content, ignore_fun):
  """Print failure state and return if ignore_fun matches content."""
  bug = (ignore_fun(content) or '').strip()
  if bug:
    print(FAILURE_HEADER_TEMPLATE % dict(
        configs='', source_key='', suppression=bug))
    return True
  return False


def timeout_bailout(output, step_number):
  """Print info and return if in timeout pass state."""
  if output.HasTimedOut():
    # Dashed output, so that no other clusterfuzz tools can match the
    # words timeout or crash.
    print('# V8 correctness - T-I-M-E-O-U-T %d' % step_number)
    return True
  return False


def fail_bailout(output, ignore_by_output_fun):
  """Print failure state and return if ignore_by_output_fun matches output."""
  bug = (ignore_by_output_fun(output.stdout) or '').strip()
  if bug:
    print(FAILURE_HEADER_TEMPLATE % dict(
        configs='', source_key='', suppression=bug))
    return True
  return False


def print_difference(
    options, source_key, first_command, second_command,
    first_config_output, second_config_output, difference, source=None):
  # The first three entries will be parsed by clusterfuzz. Format changes
  # will require changes on the clusterfuzz side.
  first_config_label = '%s,%s' % (options.first.arch, options.first.config)
  second_config_label = '%s,%s' % (options.second.arch, options.second.config)
  source_file_text = SOURCE_FILE_TEMPLATE % source if source else ''

  if PYTHON3:
    first_stdout = first_config_output.stdout
    second_stdout = second_config_output.stdout
  else:
    first_stdout = first_config_output.stdout.decode('utf-8', 'replace')
    second_stdout = second_config_output.stdout.decode('utf-8', 'replace')
    difference = difference.decode('utf-8', 'replace')

  text = (FAILURE_TEMPLATE % dict(
      configs='%s:%s' % (first_config_label, second_config_label),
      source_file_text=source_file_text,
      source_key=source_key,
      suppression='', # We can't tie bugs to differences.
      first_config_label=first_config_label,
      second_config_label=second_config_label,
      first_config_flags=' '.join(first_command.flags),
      second_config_flags=' '.join(second_command.flags),
      first_config_output=first_stdout,
      second_config_output=second_stdout,
      source=source,
      difference=difference,
  ))
  if PYTHON3:
    print(text)
  else:
    print(text.encode('utf-8', 'replace'))


def cluster_failures(source, known_failures=None):
  """Returns a string key for clustering duplicate failures.

  Args:
    source: The original source path where the failure happened.
    known_failures: Mapping from original source path to failure key.
  """
  known_failures = known_failures or KNOWN_FAILURES
  # No source known. Typical for manually uploaded issues. This
  # requires also manual issue creation.
  if not source:
    return ORIGINAL_SOURCE_DEFAULT
  # Source is known to produce a particular failure.
  if source in known_failures:
    return known_failures[source]
  # Subsume all other sources from CrashTests under one key. Otherwise
  # failures lead to new crash tests which in turn lead to new failures.
  if source.startswith('CrashTests'):
    return ORIGINAL_SOURCE_CRASHTESTS

  # We map all remaining failures to a short hash of the original source.
  long_key = hashlib.sha1(source.encode('utf-8')).hexdigest()
  return long_key[:ORIGINAL_SOURCE_HASH_LENGTH]


def main():
  options = parse_args()

  # Suppressions are architecture and configuration specific.
  suppress = v8_suppressions.get_suppression(
      options.first.arch, options.first.config,
      options.second.arch, options.second.config,
      options.skip_suppressions,
  )

  # Static bailout based on test case content or metadata.
  kwargs = {}
  if PYTHON3:
    kwargs['encoding'] = 'utf-8'
  with open(options.testcase, 'r', **kwargs) as f:
    content = f.read()
  if content_bailout(get_meta_data(content), suppress.ignore_by_metadata):
    return RETURN_FAIL
  if content_bailout(content, suppress.ignore_by_content):
    return RETURN_FAIL

  first_cmd = v8_commands.Command(
      options,'first', options.first.d8, options.first.flags)
  second_cmd = v8_commands.Command(
      options, 'second', options.second.d8, options.second.flags)

  # Sanity checks. Run both configurations with the sanity-checks file only and
  # bail out early if different.
  if not options.skip_sanity_checks:
    first_config_output = first_cmd.run(
        SANITY_CHECKS, timeout=SANITY_CHECK_TIMEOUT_SEC)

    # Early bailout if first run was a timeout.
    if timeout_bailout(first_config_output, 1):
      return RETURN_PASS

    second_config_output = second_cmd.run(
        SANITY_CHECKS, timeout=SANITY_CHECK_TIMEOUT_SEC)

    # Bailout if second run was a timeout.
    if timeout_bailout(second_config_output, 2):
      return RETURN_PASS

    difference, _ = suppress.diff(first_config_output, second_config_output)
    if difference:
      # Special source key for sanity checks so that clusterfuzz dedupes all
      # cases on this in case it's hit.
      source_key = 'sanity check failed'
      print_difference(
          options, source_key, first_cmd, second_cmd,
          first_config_output, second_config_output, difference)
      return RETURN_FAIL

  first_config_output = first_cmd.run(
      options.testcase, timeout=TEST_TIMEOUT_SEC, verbose=True)

  # Early bailout if first run was a timeout.
  if timeout_bailout(first_config_output, 1):
    return RETURN_PASS

  second_config_output = second_cmd.run(
      options.testcase, timeout=TEST_TIMEOUT_SEC, verbose=True)

  # Bailout if second run was a timeout.
  if timeout_bailout(second_config_output, 2):
    return RETURN_PASS

  difference, source = suppress.diff(first_config_output, second_config_output)

  if difference:
    # Only bail out due to suppressed output if there was a difference. If a
    # suppression doesn't show up anymore in the statistics, we might want to
    # remove it.
    if fail_bailout(first_config_output, suppress.ignore_by_output1):
      return RETURN_FAIL
    if fail_bailout(second_config_output, suppress.ignore_by_output2):
      return RETURN_FAIL

    source_key = cluster_failures(source)
    print_difference(
        options, source_key, first_cmd, second_cmd,
        first_config_output, second_config_output, difference, source)
    return RETURN_FAIL

  # Show if a crash has happened in one of the runs and no difference was
  # detected.
  if first_config_output.HasCrashed():
    print('# V8 correctness - C-R-A-S-H 1')
  elif second_config_output.HasCrashed():
    print('# V8 correctness - C-R-A-S-H 2')
  else:
    # TODO(machenbach): Figure out if we could also return a bug in case
    # there's no difference, but one of the line suppressions has matched -
    # and without the match there would be a difference.
    print('# V8 correctness - pass')

  return RETURN_PASS


if __name__ == "__main__":
  try:
    result = main()
  except SystemExit:
    # Make sure clusterfuzz reports internal errors and wrong usage.
    # Use one label for all internal and usage errors.
    print(FAILURE_HEADER_TEMPLATE % dict(
        configs='', source_key='', suppression='wrong_usage'))
    result = RETURN_FAIL
  except MemoryError:
    # Running out of memory happens occasionally but is not actionable.
    print('# V8 correctness - pass')
    result = RETURN_PASS
  except Exception as e:
    print(FAILURE_HEADER_TEMPLATE % dict(
        configs='', source_key='', suppression='internal_error'))
    print('# Internal error: %s' % e)
    traceback.print_exc(file=sys.stdout)
    result = RETURN_FAIL

  sys.exit(result)