Adding untrusted crash dump / stack trace tests.

tests/untrusted_crash_dump/decode_dump.py

+#!/usr/bin/python
+# Copyright (c) 2012 The Native Client Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Utility to decode a crash dump generated by untrusted_crash_dump.[ch]
+
+Current this produces a simple stack trace.

[Mark Seaborn, 2012/02/06 19:44:06]

'Currently'

[bradn, 2012/02/06 22:27:48]

Done.

+"""
+
+import json
+import optparse
+import os
+import posixpath
+import subprocess
+import sys
+
+
+def Addr2Line(options, filename, addr):
+  """Use addr2line to decode a code address.
+
+  Args:
+    options: option object.
+    filename: filename of module that the address is relative to.
+    addr: address.
+  Returns:
+    Dict containing: function, filename, lineno.
+  """
+  filepart = posixpath.split(filename)[1]

[Mark Seaborn, 2012/02/06 19:44:06]

Use posixpath.dirname()?

[bradn, 2012/02/06 22:27:48]

I assume you mean basename.
Done.

+  nmf_entry = options.nmf_data.get('files', {}).get(filepart, {})
+  nmf_url = nmf_entry.get('x86-32', {}).get('url')

[Mark Seaborn, 2012/02/06 19:44:06]

Add a TODO for the 'x86-32' part.

[bradn, 2012/02/06 22:27:48]

Done.

+  if nmf_url:
+    for p in [os.path.os.path.dirname(options.nmf), options.toolchain_libs]:
+      if not p: continue

[Mark Seaborn, 2012/02/06 19:44:06]

Split into two lines.

[bradn, 2012/02/06 22:27:48]

Done.

+      pfilename = os.path.join(p, nmf_url)
+      if os.path.exists(pfilename):
+        filename = pfilename
+        break

[Mark Seaborn, 2012/02/06 19:44:06]

Split this loop into a separate lookup function, and use 'return' instead of
'break'?

[bradn, 2012/02/06 22:27:48]

Done.

+
+  if filename in ['NaClMain', '(null)']:
+    if options.main_nexe:
+      filename = options.main_nexe
+    else:
+      return {
+          'function': 'Unknown_function',
+          'filename': 'unknown_file',
+          'lineno': '-1',
+      }
+  cmd = [
+      options.addr2line, '-f', '-e', filename, ('0x%08x' % addr),

[Mark Seaborn, 2012/02/06 19:44:06]

Ideally you should also use '--inlines', and check for multiple results.

[bradn, 2012/02/06 22:27:48]

Done.

+  ]
+  p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
+  (p_stdout, p_stderr) = p.communicate()

[Mark Seaborn, 2012/02/06 19:44:06]

BTW, you can use
var1, var2 = foo()
without the brackets.

[bradn, 2012/02/06 22:27:48]

Done.

+  assert p.returncode == 0
+  (func, fline) = p_stdout.rstrip().split('\n')
+  (afilename, lineno) = fline.split(':')
+  return {
+      'function': func,
+      'filename': afilename,
+      'lineno': lineno,
+  }
+
+
+def Decode(options, core_path, dst_trace):

[Mark Seaborn, 2012/02/06 19:44:06]

'dst' -> 'dest'

[bradn, 2012/02/06 22:27:48]

Done.

+  """Given a core.json file, decode and emit a stack trace.
+
+  Args:
+    options: options object.
+    core_path: source file containing a dump.
+    dst_trace: output file to write the trace to.
+  """
+  core_text = open(core_path, 'r').read()
+  core = json.loads(core_text)
+  out = open(dst_trace, 'w')
+  for f in core['frames']:

[Mark Seaborn, 2012/02/06 19:44:06]

'f' -> 'frame'

[bradn, 2012/02/06 22:27:48]

Done.

+    ip_mapped = f['ip_mapped']
+    info = Addr2Line(options, ip_mapped['file'], ip_mapped['addr'])
+    out.write('%s at %s:%s\n' % (
+        info['function'],
+        posixpath.split(info['filename'])[1],

[Mark Seaborn, 2012/02/06 19:44:06]

posixpath.basename()?  But why do you want to drop the full path?

[bradn, 2012/02/06 22:27:48]

To allow golden stace traces.
I've added a verbose flag to keep the full path.

+        info['lineno']))
+  out.close()
+
+
+def Main(args):
+  parser = optparse.OptionParser(
+      usage='USAGE: %prog [options] <core.json> <trace>')
+  parser.add_option('-m', '--main-nexe', dest='main_nexe',
+                    help='nexe to resolve NaClMain references from')
+  parser.add_option('-n', '--nmf', dest='nmf',
+                    help='nmf to resolve references from')
+  parser.add_option('-a', '--addr2line', dest='addr2line',
+                    help='path to appropriate addr2line')
+  parser.add_option('-l', '--toolchain-libs', dest='toolchain_libs',
+                    help='path to the toolchain libraries')
+  options, args = parser.parse_args(args)
+  if len(args) != 2:
+    parser.print_help()
+    sys.exit(1)
+  if options.nmf:
+    options.nmf_data = json.loads(open(options.nmf, 'r').read())
+  else:
+    options.nmf_data = {}
+  Decode(options, args[0], args[1])
+
+
+if __name__ == '__main__':
+  Main(sys.argv[1:])