Android: adds stack symbolization utilities.

build/android/symbolize.py

Index: build/android/symbolize.py
diff --git a/build/android/symbolize.py b/build/android/symbolize.py
new file mode 100755
index 0000000000000000000000000000000000000000..909d6615341f29df71fcbdcdc1c390305014b4fd
--- /dev/null
+++ b/build/android/symbolize.py
@@ -0,0 +1,80 @@
+#!/usr/bin/env python
+#
+# Copyright (c) 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

[scherkus (not reviewing), 2013/07/09 00:17:32]

FYI this isn't included in this CL

are we planning on upstreaming this module? if not, we'll have to look into
breaking the dependency by rewriting the missing bits :\

+
+# Sample output from base/debug/stack_trace_android.cc
+#00 pc 000634c1 /data/app-lib/org.chromium.native_test-1/libbase_unittests.so
+TRACE_LINE = re.compile('(?P<frame>\#[0-9]+) pc (?P<addr>[0-9a-f]{8,8}) '
+                        '(?P<lib>[^\r\n \t]+)')
+
+class Symbolizer(object):
+  def __init__(self, file_in, file_out):
+    self.file_in = file_in
+    self.file_out = file_out
+
+  def ProcessInput(self):
+    for line in self.file_in:
+      match = re.search(TRACE_LINE, line)
+      if not match:
+        self.file_out.write(line)
+        self.file_out.flush()
+        continue
+
+      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:
+        self.file_out.write(line)
+        self.file_out.flush()
+        continue
+
+      pre = line[0:match.start('frame')]
+      post = line[match.end('lib'):]
+
+      self.file_out.write('%s%s pc %s %s%s' % (pre, frame, addr, sym, post))
+      self.file_out.flush()
+
+
+def main():
+  symbolizer = Symbolizer(sys.stdin, sys.stdout)
+  symbolizer.ProcessInput()
+
+
+if __name__ == '__main__':
+  main()