Add support for dump allocations created in a certain time window

This allows for debugging e.g. objects that are not deleted during a page reload. I also added a tool for parsing and symbolizing the traces.

BUG=none
TEST=manual

Review URL: https://chromiumcodereview.appspot.com/10541026

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@141404 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 91 insertions, 0 deletions

diff --git a/tools/tcmalloc/print-live-objects.py b/tools/tcmalloc/print-live-objects.py
new file mode 100755
index 0000000..9886fd1
--- /dev/null
+++ b/tools/tcmalloc/print-live-objects.py
@@ -0,0 +1,91 @@
+#!/usr/bin/env python
+# Copyright (c) 2012 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 and prints live objects as recorded by tcmalloc's
+HeapProfilerDumpLiveObjects.
+"""
+
+import os
+import re
+import subprocess
+import sys
+import tempfile
+
+def usage():
+  print """\
+Usage:
+  tools/tcmalloc/print-live-objects.py out/Debug/chrome leaks.dmp
+"""
+
+def LoadDump(dump_file):
+  result = []
+  leakfmt = re.compile(
+      r"^\s*1:\s*(\d+)\s*\[\s*1:\s*\d+\]\s*@(0x[a-f0-9]+)((\s+0x[a-f0-9]+)*)$")
+  line_no = 0
+  with open(dump_file) as f:
+    for line in f:
+      line_no = line_no + 1
+      matches = leakfmt.match(line)
+      if not matches:
+        print "%s: could not parse line %d, skipping" % (dump_file, line_no)
+      else:
+        trace = { "size": int(matches.group(1)),
+                  "address": matches.group(2),
+                  "frames": matches.group(3).strip().split(" ")}
+        result.append(trace)
+  return result
+
+
+def Symbolize(binary, traces):
+  addresses = set()
+  for trace in traces:
+    for frame in trace["frames"]:
+      addresses.add(frame)
+  addr_file, addr_filename = tempfile.mkstemp()
+  for addr in addresses:
+    os.write(addr_file, "%s\n" % addr)
+  os.close(addr_file)
+  syms = subprocess.Popen([
+      "addr2line", "-f", "-C", "-e", binary, "@%s" % addr_filename],
+      stdout=subprocess.PIPE).communicate()[0].strip().split("\n")
+  table = {}
+  cwd = os.getcwd()
+  for address, symbol, location in zip(addresses, syms[::2], syms[1::2]):
+    if location != "??:0":
+      filename, line = location.split(":")
+      filename = os.path.realpath(filename)[len(cwd)+1:]
+      location = "%s:%s" % (filename, line)
+    table[address] = { "name": symbol, "location": location }
+  for trace in traces:
+    frames = []
+    for frame in trace["frames"]:
+      frames.append(table[frame])
+    trace["frames"] = frames
+
+
+def Main(argv):
+  if sys.platform != 'linux2':
+    print 'print-live-objects.py requires addr2line only present on Linux.'
+    sys.exit(1)
+
+  if len(argv) != 3:
+    usage()
+    sys.exit(1)
+
+  traces = LoadDump(argv[2])
+  Symbolize(argv[1], traces)
+
+  if not traces:
+    print "No leaks found!"
+
+  for trace in traces:
+    print "Leak of %d bytes at address %s" % (trace["size"], trace["address"])
+    for frame in trace["frames"]:
+      print "  %s (%s)" % (frame["name"], frame["location"])
+    print ""
+
+
+if __name__ == '__main__':
+  Main(sys.argv)