1 files changed, 112 insertions, 0 deletions
diff --git a/tools/rb/find_leakers.py b/tools/rb/find_leakers.py
new file mode 100755
index 0000000000..0359d6fefb
--- /dev/null
+++ b/tools/rb/find_leakers.py
@@ -0,0 +1,112 @@
+#!/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.
+
+from __future__ import absolute_import, print_function
+
+import sys
+
+import six
+
+
+def print_output(allocation, obj_to_class):
+    """Formats and prints output."""
+    items = []
+    for (
+        obj,
+        count,
+    ) in six.iteritems(allocation):
+        # 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()