#!/usr/bin/python

# Script to compare testsuite failures against a list of known-to-fail
# tests.

# Contributed by Diego Novillo <dnovillo@google.com>
#
# Copyright (C) 2011 Free Software Foundation, Inc.
#
# This file is part of GCC.
#
# GCC is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3, or (at your option)
# any later version.
#
# GCC is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with GCC; see the file COPYING.  If not, write to
# the Free Software Foundation, 51 Franklin Street, Fifth Floor,
# Boston, MA 02110-1301, USA.

"""This script provides a coarser XFAILing mechanism that requires no
detailed DejaGNU markings.  This is useful in a variety of scenarios:

- Development branches with many known failures waiting to be fixed.
- Release branches with known failures that are not considered
  important for the particular release criteria used in that branch.

The script must be executed from the toplevel build directory.  When
executed it will:

1- Determine the target built: TARGET
2- Determine the source directory: SRCDIR
3- Look for a failure manifest file in
   <SRCDIR>/contrib/testsuite-management/<TARGET>.xfail
4- Collect all the <tool>.sum files from the build tree.
5- Produce a report stating:
   a- Failures expected in the manifest but not present in the build.
   b- Failures in the build not expected in the manifest.
6- If all the build failures are expected in the manifest, it exits
   with exit code 0.  Otherwise, it exits with error code 1.
"""

import optparse
import os
import re
import sys

# Handled test results.
_VALID_TEST_RESULTS = [ 'FAIL', 'UNRESOLVED', 'XPASS', 'ERROR' ]

# Pattern for naming manifest files.  The first argument should be
# the toplevel GCC source directory.  The second argument is the
# target triple used during the build.
_MANIFEST_PATH_PATTERN = '%s/contrib/testsuite-management/%s.xfail'

def Error(msg):
  print >>sys.stderr, '\nerror: %s' % msg
  sys.exit(1)


class TestResult(object):
  """Describes a single DejaGNU test result as emitted in .sum files.

  We are only interested in representing unsuccessful tests.  So, only
  a subset of all the tests are loaded.

  The summary line used to build the test result should have this format:

  attrlist | XPASS: gcc.dg/unroll_1.c (test for excess errors)
  ^^^^^^^^   ^^^^^  ^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^
  optional   state  name              description
  attributes

  Attributes:
    attrlist: A comma separated list of attributes.
      Valid values:
        flaky            Indicates that this test may not always fail.  These
                         tests are reported, but their presence does not affect
                         the results.

        expire=YYYYMMDD  After this date, this test will produce an error
                         whether it is in the manifest or not.

    state: One of UNRESOLVED, XPASS or FAIL.
    name: File name for the test.
    description: String describing the test (flags used, dejagnu message, etc)
  """

  def __init__(self, summary_line):
    try:
      self.attrs = ''
      if '|' in summary_line:
        (self.attrs, summary_line) = summary_line.split('|', 1)
      (self.state,
       self.name,
       self.description) = re.match(r' *([A-Z]+): ([^ ]+) (.*)',
                                    summary_line).groups()
      self.attrs = self.attrs.strip()
      self.state = self.state.strip()
      self.description = self.description.strip()
    except ValueError:
      Error('Cannot parse summary line "%s"' % summary_line)

    if self.state not in _VALID_TEST_RESULTS:
      Error('Invalid test result %s in "%s" (parsed as "%s")' % (
            self.state, summary_line, self))

  def __lt__(self, other):
    return self.name < other.name

  def __hash__(self):
    return hash(self.state) ^ hash(self.name) ^ hash(self.description)

  def __eq__(self, other):
    return (self.state == other.state and
            self.name == other.name and
            self.description == other.description)

  def __ne__(self, other):
    return not (self == other)

  def __str__(self):
    attrs = ''
    if self.attrs:
      attrs = '%s | ' % self.attrs
    return '%s%s: %s %s' % (attrs, self.state, self.name, self.description)


def GetMakefileValue(makefile_name, value_name):
  if os.path.exists(makefile_name):
    with open(makefile_name) as makefile:
      for line in makefile:
        if line.startswith(value_name):
          (_, value) = line.split('=', 1)
          value = value.strip()
          return value
  return None


def ValidBuildDirectory(builddir, target):
  if (not os.path.exists(builddir) or
      not os.path.exists('%s/Makefile' % builddir) or
      (not os.path.exists('%s/build-%s' % (builddir, target)) and
       not os.path.exists('%s/%s' % (builddir, target)))):
    return False
  return True


def IsInterestingResult(line):
  """Return True if the given line is one of the summary lines we care about."""
  line = line.strip()
  if line.startswith('#'):
    return False
  if '|' in line:
    (_, line) = line.split('|', 1)
  line = line.strip()
  for result in _VALID_TEST_RESULTS:
    if line.startswith(result):
      return True
  return False


def ParseSummary(sum_fname):
  """Create a set of TestResult instances from the given summary file."""
  result_set = set()
  with open(sum_fname) as sum_file:
    for line in sum_file:
      if IsInterestingResult(line):
        result_set.add(TestResult(line))
  return result_set


def GetManifest(manifest_name):
  """Build a set of expected failures from the manifest file.

  Each entry in the manifest file should have the format understood
  by the TestResult constructor.

  If no manifest file exists for this target, it returns an empty
  set.
  """
  if os.path.exists(manifest_name):
    return ParseSummary(manifest_name)
  else:
    return set()


def GetSumFiles(builddir):
  sum_files = []
  for root, dirs, files in os.walk(builddir):
    if '.svn' in dirs:
      dirs.remove('.svn')
    for fname in files:
      if fname.endswith('.sum'):
        sum_files.append(os.path.join(root, fname))
  return sum_files


def GetResults(builddir):
  """Collect all the test results from .sum files under the given build
  directory."""
  sum_files = GetSumFiles(builddir)
  build_results = set()
  for sum_fname in sum_files:
    print '\t%s' % sum_fname
    build_results |= ParseSummary(sum_fname)
  return build_results


def CompareResults(manifest, actual):
  """Compare sets of results and return two lists:
     - List of results present in MANIFEST but missing from ACTUAL.
     - List of results present in ACTUAL but missing from MANIFEST.
  """
  # Report all the actual results not present in the manifest.
  actual_vs_manifest = set()
  for actual_result in actual:
    if actual_result not in manifest:
      actual_vs_manifest.add(actual_result)

  # Simlarly for all the tests in the manifest.
  manifest_vs_actual = set()
  for expected_result in manifest:
    # Ignore tests marked flaky.
    if 'flaky' in expected_result.attrs:
      continue
    if expected_result not in actual:
      manifest_vs_actual.add(expected_result)

  return actual_vs_manifest, manifest_vs_actual


def GetBuildData(options):
  target = GetMakefileValue('%s/Makefile' % options.build_dir, 'target=')
  srcdir = GetMakefileValue('%s/Makefile' % options.build_dir, 'srcdir =')
  if not ValidBuildDirectory(options.build_dir, target):
    Error('%s is not a valid GCC top level build directory.' %
          options.build_dir)
  print 'Source directory: %s' % srcdir
  print 'Build target:     %s' % target
  return srcdir, target, True


def PrintSummary(msg, summary):
  print '\n\n%s' % msg
  for result in sorted(summary):
    print result


def CheckExpectedResults(options):
  (srcdir, target, valid_build) = GetBuildData(options)
  if not valid_build:
    return False

  manifest_name = _MANIFEST_PATH_PATTERN % (srcdir, target)
  print 'Manifest:         %s' % manifest_name
  manifest = GetManifest(manifest_name)

  print 'Getting actual results from build'
  actual = GetResults(options.build_dir)

  if options.verbosity >= 1:
    PrintSummary('Tests expected to fail', manifest)
    PrintSummary('\nActual test results', actual)

  actual_vs_manifest, manifest_vs_actual = CompareResults(manifest, actual)

  tests_ok = True
  if len(actual_vs_manifest) > 0:
    PrintSummary('Build results not in the manifest', actual_vs_manifest)
    tests_ok = False

  if len(manifest_vs_actual) > 0:
    PrintSummary('Manifest results not present in the build'
                 '\n\nNOTE: This is not a failure.  It just means that the '
                 'manifest expected\nthese tests to fail, '
                 'but they worked in this configuration.\n',
                 manifest_vs_actual)

  if tests_ok:
    print '\nSUCCESS: No unexpected failures.'

  return tests_ok


def ProduceManifest(options):
  (srcdir, target, valid_build) = GetBuildData(options)
  if not valid_build:
    return False

  manifest_name = _MANIFEST_PATH_PATTERN % (srcdir, target)
  if os.path.exists(manifest_name) and not options.force:
    Error('Manifest file %s already exists.\nUse --force to overwrite.' %
          manifest_name)

  actual = GetResults(options.build_dir)
  with open(manifest_name, 'w') as manifest_file:
    for result in sorted(actual):
      print result
      manifest_file.write('%s\n' % result)

  return True


def Main(argv):
  parser = optparse.OptionParser(usage=__doc__)
  parser.add_option('--build_dir', action='store', type='string',
                    dest='build_dir', default='.',
                    help='Build directory to check (default = .)')
  parser.add_option('--manifest', action='store_true', dest='manifest',
                    default=False, help='Produce the manifest for the current '
                    'build (default = False)')
  parser.add_option('--force', action='store_true', dest='force',
                    default=False, help='When used with --manifest, it will '
                    'overwrite an existing manifest file (default = False)')
  parser.add_option('--verbosity', action='store', dest='verbosity',
                    type='int', default=0, help='Verbosity level (default = 0)')
  (options, _) = parser.parse_args(argv[1:])

  if options.manifest:
    retval = ProduceManifest(options)
  else:
    retval = CheckExpectedResults(options)

  if retval:
    return 0
  else:
    return 1

if __name__ == '__main__':
  retval = Main(sys.argv)
  sys.exit(retval)