#!/usr/bin/env python

# Copyright (c) 2012 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

from third_party import asan_symbolize

import argparse
import base64
import json
import os
import sys

class LineBuffered(object):
  """Disable buffering on a file object."""
  def __init__(self, stream):
    self.stream = stream

  def write(self, data):
    self.stream.write(data)
    if '\n' in data:
      self.stream.flush()

  def __getattr__(self, attr):
    return getattr(self.stream, attr)


def disable_buffering():
  """Makes this process and child processes stdout unbuffered."""
  if not os.environ.get('PYTHONUNBUFFERED'):
    # Since sys.stdout is a C++ object, it's impossible to do
    # sys.stdout.write = lambda...
    sys.stdout = LineBuffered(sys.stdout)
    os.environ['PYTHONUNBUFFERED'] = 'x'


def set_symbolizer_path():
  """Set the path to the llvm-symbolize binary in the Chromium source tree."""
  if not os.environ.get('LLVM_SYMBOLIZER_PATH'):
    script_dir = os.path.dirname(os.path.abspath(__file__))
    # Assume this script resides three levels below src/ (i.e.
    # src/tools/valgrind/asan/).
    src_root = os.path.join(script_dir, "..", "..", "..")
    symbolizer_path = os.path.join(src_root, 'third_party',
        'llvm-build', 'Release+Asserts', 'bin', 'llvm-symbolizer')
    assert(os.path.isfile(symbolizer_path))
    os.environ['LLVM_SYMBOLIZER_PATH'] = os.path.abspath(symbolizer_path)


# Construct a path to the .dSYM bundle for the given binary.
# There are three possible cases for binary location in Chromium:
# 1. The binary is a standalone executable or dynamic library in the product
#    dir, the debug info is in "binary.dSYM" in the product dir.
# 2. The binary is a standalone framework or .app bundle, the debug info is in
#    "Framework.framework.dSYM" or "App.app.dSYM" in the product dir.
# 3. The binary is a framework or an .app bundle within another .app bundle
#    (e.g. Outer.app/Contents/Versions/1.2.3.4/Inner.app), and the debug info
#    is in Inner.app.dSYM in the product dir.
# The first case is handled by llvm-symbolizer, so we only need to construct
# .dSYM paths for .app bundles and frameworks.
# We're assuming that there're no more than two nested bundles in the binary
# path. Only one of these bundles may be a framework and frameworks cannot
# contain other bundles.
def chrome_dsym_hints(binary):
  path_parts = binary.split(os.path.sep)
  app_positions = []
  framework_positions = []
  for index, part in enumerate(path_parts):
    if part.endswith('.app'):
      app_positions.append(index)
    elif part.endswith('.framework'):
      framework_positions.append(index)
  bundle_positions = app_positions + framework_positions
  bundle_positions.sort()
  assert len(bundle_positions) <= 2, \
      "The path contains more than two nested bundles: %s" % binary
  if len(bundle_positions) == 0:
    # Case 1: this is a standalone executable or dylib.
    return []
  assert (not (len(app_positions) == 1 and
               len(framework_positions) == 1 and
               app_positions[0] > framework_positions[0])), \
      "The path contains an app bundle inside a framework: %s" % binary
  # Cases 2 and 3. The outermost bundle (which is the only bundle in the case 2)
  # is located in the product dir.
  outermost_bundle = bundle_positions[0]
  product_dir = path_parts[:outermost_bundle]
  # In case 2 this is the same as |outermost_bundle|.
  innermost_bundle = bundle_positions[-1]
  dsym_path = product_dir + [path_parts[innermost_bundle]]
  result = '%s.dSYM' % os.path.sep.join(dsym_path)
  return [result]


# We want our output to match base::EscapeJSONString(), which produces
# doubly-escaped strings. The first escaping pass is handled by this class. The
# second pass happens when JSON data is dumped to file.
class StringEncoder(json.JSONEncoder):
  def __init__(self):
    json.JSONEncoder.__init__(self)

  def encode(self, s):
    assert(isinstance(s, basestring))
    encoded = json.JSONEncoder.encode(self, s)
    assert(len(encoded) >= 2)
    assert(encoded[0] == '"')
    assert(encoded[-1] == '"')
    encoded = encoded[1:-1]
    # Special case from base::EscapeJSONString().
    encoded = encoded.replace('<', '\u003C')
    return encoded


class JSONTestRunSymbolizer(object):
  def __init__(self, symbolization_loop):
    self.string_encoder = StringEncoder()
    self.symbolization_loop = symbolization_loop

  def symbolize_snippet(self, snippet):
    symbolized_lines = []
    for line in snippet.split('\n'):
      symbolized_lines += self.symbolization_loop.process_line(line)
    return '\n'.join(symbolized_lines)

  def symbolize(self, test_run):
    original_snippet = base64.b64decode(test_run['output_snippet_base64'])
    symbolized_snippet = self.symbolize_snippet(original_snippet)
    if symbolized_snippet == original_snippet:
      # No sanitizer reports in snippet.
      return

    test_run['original_output_snippet'] = test_run['output_snippet']
    test_run['original_output_snippet_base64'] = \
        test_run['output_snippet_base64']

    escaped_snippet = StringEncoder().encode(symbolized_snippet)
    test_run['output_snippet'] = escaped_snippet
    test_run['output_snippet_base64'] = \
        base64.b64encode(symbolized_snippet)
    test_run['snippet_processed_by'] = 'asan_symbolize.py'
    # Originally, "lossless" refers to "no Unicode data lost while encoding the
    # string". However, since we're applying another kind of transformation
    # (symbolization), it doesn't seem right to consider the snippet lossless.
    test_run['losless_snippet'] = False


def symbolize_snippets_in_json(filename, symbolization_loop):
  with open(filename, 'r') as f:
    json_data = json.load(f)

  test_run_symbolizer = JSONTestRunSymbolizer(symbolization_loop)
  for iteration_data in json_data['per_iteration_data']:
    for test_name, test_runs in iteration_data.iteritems():
      for test_run in test_runs:
        test_run_symbolizer.symbolize(test_run)

  with open(filename, 'w') as f:
    json.dump(json_data, f, indent=3, sort_keys=True)


def main():
  parser = argparse.ArgumentParser(description='Symbolize sanitizer reports.')
  parser.add_argument('--test-summary-json-file',
      help='Path to a JSON file produced by the test launcher. The script will '
           'ignore stdandard input and instead symbolize the output stnippets '
           'inside the JSON file. The result will be written back to the JSON '
           'file.')
  parser.add_argument('strip_path_prefix', nargs='*',
      help='When printing source file names, the longest prefix ending in one '
           'of these substrings will be stripped. E.g.: "Release/../../".')
  args = parser.parse_args()

  disable_buffering()
  set_symbolizer_path()
  asan_symbolize.demangle = True
  asan_symbolize.fix_filename_patterns = args.strip_path_prefix
  loop = asan_symbolize.SymbolizationLoop(dsym_hint_producer=chrome_dsym_hints)

  if args.test_summary_json_file:
    symbolize_snippets_in_json(args.test_summary_json_file, loop)
  else:
    # Process stdin.
    asan_symbolize.logfile = sys.stdin
    loop.process_logfile()

if __name__ == '__main__':
  main()