1 files changed, 100 insertions, 0 deletions
diff --git a/tools/rb/find_leakers.py b/tools/rb/find_leakers.py
new file mode 100755
index 000000000..4405d7a17
--- /dev/null
+++ b/tools/rb/find_leakers.py
@@ -0,0 +1,100 @@
+#!/usr/bin/python
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# This script processes a `refcount' log, and finds out if any object leaked.
+# It simply goes through the log, finds `AddRef' or `Ctor' lines, and then
+# sees if they `Release' or `Dtor'. If not, it reports them as leaks.
+# Please see README file in the same directory.
+
+
+import sys
+
+def print_output(allocation, obj_to_class):
+    '''Formats and prints output.'''
+    items = []
+    for obj, count, in allocation.iteritems():
+        # Adding items to a list, so we can sort them.
+        items.append((obj, count))
+    # Sorting by count.
+    items.sort(key=lambda item: item[1])
+
+    for obj, count, in items:
+        print "{obj} ({count}) @ {class_name}".format(obj=obj,
+                                                      count=count,
+                                                      class_name=obj_to_class[obj])
+
+def process_log(log_lines):
+    '''Process through the log lines, and print out the result.
+
+    @param log_lines: List of strings.
+    '''
+    allocation = {}
+    class_count = {}
+    obj_to_class = {}
+
+    for log_line in log_lines:
+        if not log_line.startswith('<'):
+            continue
+
+        (class_name,
+         obj,
+         ignore,
+         operation,
+         count,) = log_line.strip('\r\n').split(' ')[:5]
+
+        # for AddRef/Release `count' is the refcount,
+        # for Ctor/Dtor it's the size.
+
+        if ((operation == 'AddRef' and count == '1') or
+           operation == 'Ctor'):
+            # Examples:
+            #     <nsStringBuffer> 0x01AFD3B8 1 AddRef 1
+            #     <PStreamNotifyParent> 0x08880BD0 8 Ctor (20)
+            class_count[class_name] = class_count.setdefault(class_name, 0) + 1
+            allocation[obj] = class_count[class_name]
+            obj_to_class[obj] = class_name
+
+        elif ((operation == 'Release' and count == '0') or
+             operation == 'Dtor'):
+            # Examples:
+            #     <nsStringBuffer> 0x01AFD3B8 1 Release 0
+            #     <PStreamNotifyParent> 0x08880BD0 8 Dtor (20)
+            if obj not in allocation:
+                print "An object was released that wasn't allocated!",
+                print obj, "@", class_name
+            else:
+                allocation.pop(obj)
+            obj_to_class.pop(obj)
+
+    # Printing out the result.
+    print_output(allocation, obj_to_class)
+
+
+def print_usage():
+    print
+    print "Usage: find-leakers.py [log-file]"
+    print
+    print "If `log-file' provided, it will read that as the input log."
+    print "Else, it will read the stdin as the input log."
+    print
+
+def main():
+    '''Main method of the script.'''
+    if len(sys.argv) == 1:
+        # Reading log from stdin.
+        process_log(sys.stdin.readlines())
+    elif len(sys.argv) == 2:
+        # Reading log from file.
+        with open(sys.argv[1], 'r') as log_file:
+            log_lines = log_file.readlines()
+        process_log(log_lines)
+    else:
+        print 'ERROR: Invalid number of arguments'
+        print_usage()
+
+if __name__ == '__main__':
+    main()
+