simplify_stacktraces

#!/usr/bin/env python3
# Copyright 2019 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

""" Pipe `fx syslog` through this tool for simpler stack traces.

E.g. `fx syslog | scripts/simplify_stacktraces`.
"""

import sys
import re

TEMPLATE_TAG = "###TEMPLATE###"

class TerminalEscapeCodes:
    GREEN = '\033[92m'
    ENDC = '\033[0m'
    UNDERLINE = '\033[4m'

def simplify_cpp_file_path(path):
  return re.sub(r"^../../out/[^/]+/../../", "", path)

def simplify_cpp_function_signature(function):
  # To find "core part" to underline, strip out all param lists and templated
  # types.
  core_part = function
  while True:
    prev = core_part
    core_part = re.sub(r"<[^<>]*>", "", core_part)
    core_part = re.sub(r"\([^\(\)]*\)", "", core_part)
    if prev == core_part:
      break
  core_part = re.sub(r"::\$[^:]+::operator", "", core_part)
  core_part = re.sub(r"::'lambda'::operator", "", core_part)
  core_part = re.sub(r"auto ", "", core_part)
  core_part = re.sub(r"void ", "", core_part)
  core_part = re.sub(r" const", "", core_part)

  # To make function signature less verbose, replace templates with <...>
  signature = function
  while True:
    prev = signature
    signature = re.sub(r"<[^<>]+>", TEMPLATE_TAG, signature)
    if prev == signature:
      break
  signature = re.sub(TEMPLATE_TAG, "<>", signature)
  # Underline the "core part" in the signature
  signature = signature.replace(core_part, TerminalEscapeCodes.UNDERLINE +
                                core_part + TerminalEscapeCodes.ENDC)
  return signature

def is_cpp_stacktrace_entry(parts):
  return len(parts) >= 7 and parts[3][:3] == "0x0"

def simplify_cpp_stacktrace_entry(parts):
  prefix = parts[0]  # "[01127.479810][1169][1262][klog]"
  level = parts[1]   # "INFO:"
  index = parts[2]   # "#1"
  symbol = parts[3]  # "0x00005a22a477d585"
  function = " ".join(parts[5:-2])  # function signature, can contain spaces
  file_path = parts[-2]   # file path

  function = simplify_cpp_function_signature(function)
  file_path = simplify_cpp_file_path(file_path)
  file_path = TerminalEscapeCodes.GREEN + file_path + TerminalEscapeCodes.ENDC

  return "%s %s %s" % (index, file_path, function)

def main():
  for line in sys.stdin:
    line = line.strip()
    parts = line.split()
    if is_cpp_stacktrace_entry(parts):
      print(simplify_cpp_stacktrace_entry(parts))
    else:
      # Contributions to handle other stacktrace types very welcome.
      print(line)


if __name__ == '__main__':
    sys.exit(main())