I didn't exactly understand which problem are you referring to, but the comments there give me a couple of ideas for slightly easier debugging, so thanks for that. For example, maybe i'll try to use less global variables.
However, unlike the program described there, this is a static analyzer - it is not designed to run continually, but to process a dump and that's all. The trouble is that with MediaWiki dumps that have several tens of thousands of pages the program runs out of memory and never finishes processing the whole dump. (FWIW this machine has 2 GB of RAM.)
So the problem is probably not the same and my question still stands - is there a way to inspect all the variables of a program and the modules that it uses and find out their memory consumption?