# Copyright 2017 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.

import re

from devil.android import logcat_monitor

BACKTRACE_LINE_RE = re.compile(r'#\d+')
THREADTIME_RE = re.compile(
    logcat_monitor.LogcatMonitor.THREADTIME_RE_FORMAT % (
        r' *\S* *', r' *\S* *', r' *\S* *', r' *\S* *', r'.*'))

def SymbolizeLogcat(logcat, dest, symbolizer, abi):
  """Symbolize stack trace in the logcat.

  Symbolize the logcat and write the symbolized logcat to a new file.

  Args:
    logcat: Path to logcat file.
    dest: Path to where to write the symbolized logcat.
    symbolizer: The stack symbolizer to symbolize stack trace in logcat.
    abi: The device's product_cpu_abi. Symbolizer needs it to symbolize.

  A sample logcat that needs to be symbolized, after stripping the prefix,
  such as '08-07 18:39:37.692 28649 28649 E Ion     : ', would be:
  Build fingerprint: 'google/shamu/shamu:7.1.1/NMF20B/3370:userdebug/dev-keys'
  Revision: '0'
  ABI: 'arm'
  pid: 28936, tid: 28936, name: chromium.chrome  >>> org.chromium.chrome <<<
  signal 6 (SIGABRT), code -6 (SI_TKILL), fault addr --------
  Abort message: '[FATAL:debug_urls.cc(151)] Check failed: false.
  #00 0x63e16c41 /data/app/org.chromium.chrome-1/lib/arm/libchrome.so+0x0006cc4
  #01 0x63f19be3 /data/app/org.chromium.chrome-1/lib/arm/libchrome.so+0x0016fbe
  #02 0x63f19737 /data/app/org.chromium.chrome-1/lib/arm/libchrome.so+0x0016f73
  #03 0x63f18ddf /data/app/org.chromium.chrome-1/lib/arm/libchrome.so+0x0016edd
  #04 0x63f18b79 /data/app/org.chromium.chrome-1/lib/arm/libchrome.so+0x0016eb7
  #05 0xab53f319 /system/lib/libart.so+0x000a3319
  #06
     r0 00000000  r1 00007108  r2 00000006  r3 00000008
     r4 ae60258c  r5 00000006  r6 ae602534  r7 0000010c
     r8 bede5cd0  r9 00000030  sl 00000000  fp 9265a800
     ip 0000000b  sp bede5c38  lr ac8e5537  pc ac8e7da0  cpsr 600f0010

  backtrace:
     #00 pc 00049da0  /system/lib/libc.so (tgkill+12)
     #01 pc 00047533  /system/lib/libc.so (pthread_kill+34)
     #02 pc 0001d635  /system/lib/libc.so (raise+10)
     #03 pc 00019181  /system/lib/libc.so (__libc_android_abort+34)
     #04 pc 00017048  /system/lib/libc.so (abort+4)
     #05 pc 00948605  /data/app/org.chromium.chrome-1/lib/arm/libchrome.so
     #06 pc 002c9f73  /data/app/org.chromium.chrome-1/lib/arm/libchrome.so
     #07 pc 003ccbe1  /data/app/org.chromium.chrome-1/lib/arm/libchrome.so
     #08 pc 003cc735  /data/app/org.chromium.chrome-1/lib/arm/libchrome.so
     #09 pc 003cbddf  /data/app/org.chromium.chrome-1/lib/arm/libchrome.so
     #10 pc 003cbb77  /data/app/org.chromium.chrome-1/lib/arm/libchrome.so
  """

  with open(logcat) as logcat_file:
    with open(dest, 'w') as dest_file:
      # The current stack script will only print out the symbolized stack,
      # and completely ignore logs other than the crash log that is used for
      # symbolization, if any exists. Thus the code here extracts the
      # crash log inside the logcat and pass only the crash log to the script,
      # because we don't want to lose other information in the logcat that,
      # if passed to the stack script, will just be ignored by it.
      # TODO(crbug.com/755225): Rewrite the logic here.
      outside_of_crash_log = True
      in_lower_half_crash = False
      data_to_symbolize = []

      for line in logcat_file:
        if outside_of_crash_log:
          # Check whether it is the start of crash log.
          if 'Build fingerprint: ' in line:
            outside_of_crash_log = False
            # Only include necessary information for symbolization.
            # The logic here that removes date, time, proc_id etc.
            # should be in sync with _THREADTIME_RE_FORMAT in logcat_monitor.
            data_to_symbolize.append(
              re.search(THREADTIME_RE, line).group(7))
          else:
            dest_file.write(line)
        else:
          # Once we have reached the end of the backtrace section,
          # we will start symbolizing.
          if in_lower_half_crash and not bool(BACKTRACE_LINE_RE.search(line)):
            outside_of_crash_log = True
            in_lower_half_crash = False
            symbolized_lines = symbolizer.ExtractAndResolveNativeStackTraces(
                data_to_symbolize, abi)
            dest_file.write('\n'.join(symbolized_lines) + '\n' + line)
            data_to_symbolize = []
          else:
            if not in_lower_half_crash and 'backtrace:' in line:
              in_lower_half_crash = True
            data_to_symbolize.append(
                re.search(THREADTIME_RE, line).group(7))