Fix the stack script issue when symbolizing tombstones.

build/android/pylib/utils/symbolizer.py

+# Copyright 2017 The Chromium Authors. All rights reserved.

[agrieve, 2017/07/21 14:12:46]

nit: there's already a directory in pylib called "symbols", which has an
"elf_symbolizer.py", which is a wrapper around addr2line.

The stack script is also a wrapper around addr2line (but with added logic for
finding the stack lines from a log, as well as the ability to call objdump, and
to adjust addresses for relros & being loaded from .apk).

Anyways, the two are cetainly different enough to not want to merge them, but I
think it would still make sense to put this under "symbols" and put "stack" in
its name to distinguish it from elf_symbolizer.py

[jbudorick, 2017/07/21 14:15:07]

That sounds fine to me.

At some point, I want to reconcile the two & the stuff in android_platform --
there's quite a bit of chrome-specific logic in there.

[BigBossZhiling, 2017/07/21 18:38:14]

Done.

+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import os
+import re
+import shutil
+import tempfile
+
+from devil.utils import cmd_helper
+from pylib import constants
+
+STACK_TOOL = os.path.join(os.path.dirname(__file__), '..', '..', '..', '..',
+                          'third_party', 'android_platform', 'development',
+                          'scripts', 'stack')
+
+def _DeviceAbiToArch(device_abi):
+    # The order of this list is significant to find the more specific match
+    # (e.g., arm64) before the less specific (e.g., arm).
+    arches = ['arm64', 'arm', 'x86_64', 'x86_64', 'x86', 'mips']
+    for arch in arches:
+      if arch in device_abi:
+        return arch
+    raise RuntimeError('Unknown device ABI: %s' % device_abi)
+
+
+class Symbolizer(object):
+  """ A helper class to symbolize stack. """
+
+  def __init__(self, apk_under_test=None,
+               enable_relocation_packing=None):
+    self.apk_under_test = apk_under_test
+    self.enable_relocation_packing = enable_relocation_packing
+    self.libs_dir = tempfile.mkdtemp()
+    self.apk_libs = []
+    self.has_unzipped = False
+
+
+  def __del__(self):
+    if self.libs_dir:

[jbudorick, 2017/07/21 13:46:23]

nit: extract this into a separate function that __del__ calls. A client should
be able to tell Symbolizer when its work is done. instrumentation_test_instance,
for example, could call the new function in its TearDown method.

[BigBossZhiling, 2017/07/21 18:38:14]

Say this new function is named CleanUp. If the instrumentation_test_instance
calls CleanUp in TearDown once, we don't want to call CleanUp again in __del__
right? So I am setting libs_dir to None once we call CleanUp, so the same
directory won't be removed twice.

+      shutil.rmtree(self.libs_dir)
+
+
+  def UnzipAPK(self):

[jbudorick, 2017/07/21 13:46:23]

nit: add a docstring for this.

[BigBossZhiling, 2017/07/21 18:38:13]

Done.

+    cmd_helper.GetCmdOutput(

[jbudorick, 2017/07/21 13:46:23]

This function should know the conditions under which the apk should be unzipped
& check those. To go along with that, it should probably be named
"UnzipApkIfNecessary" or something similar.

[BigBossZhiling, 2017/07/21 18:38:13]

Done.

+        ['unzip', '-o', self.apk_under_test, '-d', self.libs_dir])
+    self.has_unzipped = True
+    if os.path.exists(os.path.join(self.libs_dir, 'lib')):
+      for root, _, files in os.walk(os.path.join(self.libs_dir,
+                                                 'lib')):
+        for file_name in files:
+          if file_name.endswith('.so'):
+            self.apk_libs.append(os.path.join(root, file_name))
+
+
+  def ResolveSymbols(self, data_to_symbolize, device_abi, include_stack=True):
+    """Run the stack tool for given input.
+
+    Args:
+      data_to_symbolize: a list of strings to symbolize.
+      include_stack: boolean whether to include stack data in output.
+      device_abi: the default ABI of the device which generated the tombstone.
+
+    Yields:
+      A string for each line of resolved stack output.
+    """
+    # Check if the data_to_symbolize has an ABI listed,

[jbudorick, 2017/07/21 13:46:23]

I think this function should still attempt to unzip the APK.

[BigBossZhiling, 2017/07/21 18:38:14]

Done.

+    # if so use this in preference to the device's default ABI.
+    for line in data_to_symbolize:
+      found_abi = re.search('ABI: \'(.+?)\'', line)

[jbudorick, 2017/07/21 13:46:23]

nit: compile this regex into a module-scope constant

[BigBossZhiling, 2017/07/21 18:38:14]

Done.

+      if found_abi:
+        device_abi = found_abi.group(1)
+    arch = _DeviceAbiToArch(device_abi)
+    if not arch:

[jbudorick, 2017/07/21 13:46:23]

nit: log a warning in this case.

[BigBossZhiling, 2017/07/21 18:38:14]

Done.

+      return
+
+    cmd = [STACK_TOOL, '--arch', arch, '--output-directory',
+           constants.GetOutDirectory()]
+    if self.enable_relocation_packing and self.apk_libs:
+      for apk_lib in self.apk_libs:
+        cmd.extend(['--packed-lib', apk_lib])
+    with tempfile.NamedTemporaryFile() as f:
+      f.write('\n'.join(data_to_symbolize))
+      f.flush()
+      _, output = cmd_helper.GetCmdStatusAndOutput(cmd + [f.name])
+    for line in output.splitlines():
+      if not include_stack and 'Stack Data:' in line:
+        break
+      yield line