tools/rb/find_leakers.py

   1 #!/usr/bin/python
   2 #
   3 # This Source Code Form is subject to the terms of the Mozilla Public
   4 # License, v. 2.0. If a copy of the MPL was not distributed with this
   5 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
   6
   7 # This script processes a `refcount' log, and finds out if any object leaked.
   8 # It simply goes through the log, finds `AddRef' or `Ctor' lines, and then
   9 # sees if they `Release' or `Dtor'. If not, it reports them as leaks.
  10 # Please see README file in the same directory.
  11
  12 from __future__ import absolute_import, print_function
  13
  14 import sys
  15
  16 import six
  17
  18
  19 def print_output(allocation, obj_to_class):
  20     """Formats and prints output."""
  21     items = []
  22     for (
  23         obj,
  24         count,
  25     ) in six.iteritems(allocation):
  26         # Adding items to a list, so we can sort them.
  27         items.append((obj, count))
  28     # Sorting by count.
  29     items.sort(key=lambda item: item[1])
  30
  31     for (
  32         obj,
  33         count,
  34     ) in items:
  35         print(
  36             "{obj} ({count}) @ {class_name}".format(
  37                 obj=obj, count=count, class_name=obj_to_class[obj]
  38             )
  39         )
  40
  41
  42 def process_log(log_lines):
  43     """Process through the log lines, and print out the result.
  44
  45     @param log_lines: List of strings.
  46     """
  47     allocation = {}
  48     class_count = {}
  49     obj_to_class = {}
  50
  51     for log_line in log_lines:
  52         if not log_line.startswith("<"):
  53             continue
  54
  55         (class_name, obj, ignore, operation, count,) = log_line.strip("\r\n").split(
  56             " "
  57         )[:5]
  58
  59         # for AddRef/Release `count' is the refcount,
  60         # for Ctor/Dtor it's the size.
  61
  62         if (operation == "AddRef" and count == "1") or operation == "Ctor":
  63             # Examples:
  64             #     <nsStringBuffer> 0x01AFD3B8 1 AddRef 1
  65             #     <PStreamNotifyParent> 0x08880BD0 8 Ctor (20)
  66             class_count[class_name] = class_count.setdefault(class_name, 0) + 1
  67             allocation[obj] = class_count[class_name]
  68             obj_to_class[obj] = class_name
  69
  70         elif (operation == "Release" and count == "0") or operation == "Dtor":
  71             # Examples:
  72             #     <nsStringBuffer> 0x01AFD3B8 1 Release 0
  73             #     <PStreamNotifyParent> 0x08880BD0 8 Dtor (20)
  74             if obj not in allocation:
  75                 print(
  76                     "An object was released that wasn't allocated!",
  77                 )
  78                 print(obj, "@", class_name)
  79             else:
  80                 allocation.pop(obj)
  81             obj_to_class.pop(obj)
  82
  83     # Printing out the result.
  84     print_output(allocation, obj_to_class)
  85
  86
  87 def print_usage():
  88     print("")
  89     print("Usage: find-leakers.py [log-file]")
  90     print("")
  91     print("If `log-file' provided, it will read that as the input log.")
  92     print("Else, it will read the stdin as the input log.")
  93     print("")
  94
  95
  96 def main():
  97     """Main method of the script."""
  98     if len(sys.argv) == 1:
  99         # Reading log from stdin.
 100         process_log(sys.stdin.readlines())
 101     elif len(sys.argv) == 2:
 102         # Reading log from file.
 103         with open(sys.argv[1], "r") as log_file:
 104             log_lines = log_file.readlines()
 105         process_log(log_lines)
 106     else:
 107         print("ERROR: Invalid number of arguments")
 108         print_usage()
 109
 110
 111 if __name__ == "__main__":
 112     main()