c - Is there a compiler feature to inject custom function entry and exit code?

Question

Currently coding on Windows with VS2005 (but wouldn't mind knowing if there are options for other compilers and platforms. I'm most interested in OSX as an alternative platform.) I have a C (no C++) program and I'd like to do the following...

Given a function, say...

int MyFunction(int myparam)
{
   // Entry point.
   ...
   // Exit point.
   return 1;
}

I'd like to put a snippet of code at the entry point and at the exit point. BUT, I'd rather not have to modify the 100's of functions that are already out there. Is there a way to define function entry and exit code that the compiler will inject for all my functions without having to modify them all?

Most solutions I've found or tried will require me to edit every single function, which is a lot of work. I figure someone else must have hit something like this already and solved it. I can't be unique in this request I suspect.

Answer 1

It's Microsoft-specific, but you can hook into the _penter and _pexit functions to do something when entering and exiting a function -- you'll have to compile your project with some special flags.

There's a little bit of a tutorial here, and you can find a few more results on how to use them on Google. Also, this blog post goes into some detail on the assembly that you need to do to avoid messing up the stack on entry and exit.