Add a snapshot of flutter/engine/src/build to our sdk

build/android/symbolize.py

+#!/usr/bin/env python
+#
+# Copyright 2013 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.
+
+"""Symbolizes stack traces generated by Chromium for Android.
+
+Sample usage:
+  adb logcat chromium:V | symbolize.py
+"""
+
+import os
+import re
+import sys
+
+from pylib import constants
+
+# Uses symbol.py from third_party/android_platform, not python's.
+sys.path.insert(0,
+                os.path.join(constants.DIR_SOURCE_ROOT,
+                            'third_party/android_platform/development/scripts'))
+import symbol
+
+# Sample output from base/debug/stack_trace_android.cc
+#00 0x693cd34f /path/to/some/libfoo.so+0x0007434f
+TRACE_LINE = re.compile(r'(?P<frame>\#[0-9]+ 0x[0-9a-f]{8,8}) '
+                        r'(?P<lib>[^+]+)\+0x(?P<addr>[0-9a-f]{8,8})')
+
+class Symbolizer(object):
+  def __init__(self, output):
+    self._output = output
+
+  def write(self, data):
+    while True:
+      match = re.search(TRACE_LINE, data)
+      if not match:
+        self._output.write(data)
+        break
+
+      frame = match.group('frame')
+      lib = match.group('lib')
+      addr = match.group('addr')
+
+      # TODO(scherkus): Doing a single lookup per line is pretty slow,
+      # especially with larger libraries. Consider caching strategies such as:
+      # 1) Have Python load the libraries and do symbol lookups instead of
+      #    calling out to addr2line each time.
+      # 2) Have Python keep multiple addr2line instances open as subprocesses,
+      #    piping addresses and reading back symbols as we find them
+      # 3) Read ahead the entire stack trace until we find no more, then batch
+      #    the symbol lookups.
+      #
+      # TODO(scherkus): These results are memoized, which could result in
+      # incorrect lookups when running this script on long-lived instances
+      # (e.g., adb logcat) when doing incremental development. Consider clearing
+      # the cache when modification timestamp of libraries change.
+      sym = symbol.SymbolInformation(lib, addr, False)[0][0]
+
+      if not sym:
+        post = match.end('addr')
+        self._output.write(data[:post])
+        data = data[post:]
+        continue
+
+      pre = match.start('frame')
+      post = match.end('addr')
+
+      self._output.write(data[:pre])
+      self._output.write(frame)
+      self._output.write(' ')
+      self._output.write(sym)
+
+      data = data[post:]
+
+  def flush(self):
+    self._output.flush()
+
+
+def main():
+  symbolizer = Symbolizer(sys.stdout)
+  for line in sys.stdin:
+    symbolizer.write(line)
+  symbolizer.flush()
+
+
+if __name__ == '__main__':
+  main()