In mozilla we have a lot of functions that always return NS_OK(0). This means that callers of such functions usually have unneeded error checking. nsresult rv = call(); if (NS_FAILED(rv)....) <-- gcc should be able to optimize this away if it knows that value of call() is always zero For reference see gcc function attributes: pure, const. and Gcc variable attribute nonnull(I don't see that one in the docs anymore, is it gone?).

alternatively/additionally we should do static analysis to ensure that always zerofunctions a) only ever return 0 b) never have their return value checked

This has a problem with being able to print off the class location of a method with a misapplied attribute. Being a ripoff of outparams.js, there may still be some unnecessary code as well.

there are some indenting issues here, particularly when a declaration is broken over several lines.

compile with make CC=/path/to/plugin-enabled/gcc (requires plugin framework from GCC 4.5)

Not sure if all of this is ready for review yet. For one thing when FIND_NEW_FUNCTIONS = true, a whole lot of output will be printed during static analysis builds. There's also a lot more patching to be done (likely with Pork).