[ILUG] Linking Electric Fence to C++

[Dermot McGahon]

On Tue, 18 May 2004 09:22:44 +0100, Bryan O'Donoghue <bryano at europlex.ie>  
wrote:

> I seem to remember in a late night meander that "new" is actually when  
> you get right down to it, some sort of overloaded call to "malloc" and  
> "delete" is some sort of overloaded call to "free".

Not an overload; implemented in terms of.

Not always, but on unix this is the way most C++ compilers
writers implement new and delete.

What you can do instead, if you don't like the defaults, is to
write your own operator new and operator delete.

> Assuming that's true, what would be the effect of linking against  
> Electric Fence here, with it's replacements for malloc and free?

Try it, but it should work fine.


> My instinct tells me that, the libc malloc & free if overloaded at the  
> C++ compiler level, *won't* be replaced, but, I might be wrong.

I see what you're saying, but it's not an overload. Load up a C++
program in gdb and step into the new call or use strace. Chances
are, you will see a standard glibc malloc call being made.

If you want to know more about this topic, Scott Meyers' Effective
C++ books are a good starting point, but the bottom line is that
on unix, new and delete ultimately resolve to standard malloc/free
calls.


Dermot.
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