cvs checkout mozilla/tools/leaky 

  ./configure --enable-leaky

By setting the LIBMALLOC_LOG environment variable you control how much information is logged during the programs execution. See libmalloc.h for a definition of the values to use. If you are using LD_PRELOAD, here is one way to run your program:

env LD_PRELOAD=/full/path/to/libleaky.so LIBMALLOC_LOG=1 my-program

Once your program has completed execution you can use leaky to look for memory leaks, or at least use it to dump the log. For memory leaks, you use leaky like this:

leaky -d <program-name-goes-here> malloc-log

leaky -d -a <program-name-goes-here> malloc-log

1. Set LIBMALLOC_LOG to "8"
2. Modify your source code so that your class::Addref and class::Release methods call __log_addref and __log_release, as appropriate. See libmalloc.h for their signatures.
3. Run your program so that you get the log data. Its often convenient to run your program in the debugger and then set a breakpoint at an interesting location where you think some object is being leaked or over-freed. Then when the debugger gets there tell it to execute DumpAddressMap. In gdb you do this:
 
(gdb) p DumpAddressMap()
 
4. Then use leaky to capture the addref and release calls to a log file:
 
leaky -d -a <program-name-goes-here> malloc-log > log
 
5. Then use "grep" to search the log for a specific object by grepping for its memory address...
6. On a typical *short* run of mozilla, I'll end up with a malloc-log file of around 5 to 10 megabytes and the resulting converted log file will be 10 to 20 times that so be prepared to have alot of disk space. It helps a great deal to narrow down your problem space to reduce the log file size...

  leaky -gqx <program-name-goes-here>  malloc-log | c++filt | sed -e 's/&/&/g' > /tmp/GQ0.html

Then leaky will make a graph of the leaks [-g] and output that graph in xml format (currently actually html...) [-x]. I use c++filt to translate the C++ mangled names into ascii and then use sed to make it legitimate html and off it goes to a file.

If you throw file at viewer (recursion is cool) then it will present you with a treeview of the leaks that you can click on to open/close sections. Screenshot below, on a test run of viewer. Enjoy!

Initial version works only on x86 linux. To work on other platforms you will need to:

1. Implement CrawlStack() in libmalloc.cpp
2. Implement DumpAddressMap() in libmalloc.cpp and in ShowLibs.cpp
3. Either support LD_PRELOAD in your dynamic linker, or
   produce a library that wraps your libc malloc (see config.h for some clues)
4. Implement symbol table reading code (see coff.cpp, elf.cpp and bfd.cpp for examples; at the time of writing this document only bfd.cpp was known to work)