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[Wolfgang Thaller]

> The "hook" idea works with static linking: the RTS provides a default
> version of the hook, that can be overriden by a user-supplied function
> of the same name.  This is what GHC does.  However, our dynamic linker
> doesn't support this kind of overriding.  The system's dynamic linker
> does, though: that's why you can still provide your own malloc() and
> functions in libc.so will use yours rather than the default one.

Note that the Darwin and (AFAIK) Windows dynamic linker do not support 
this behaviour. They explicitly avoid that kind of behaviour to prevent 
accidental overriding. (What happens on Linux if you link a 
GHC-compiled program to a shared library that internally uses a 
function named "allocate"? What if the next revision of that library 
introduces such a function?)

What are the alternatives to using these hook functions? Explicitly 
looking for a OutOfHeapHook symbol in the executable using dlsym and 
friends? Exporting a "RegisterOutOfHeapCallback" function from the rts? 
Both seem a bit inconvenient to me, but some change might be necessary 
when we use dylibs/dlls.

Cheers,

Wolfgang