[Haskell-cafe] "Standard C" available in cabal package

[Maurí­cio]

Hi,

I see that cabal allows me to say:

c-sources: (...)

and then have a few C files built with my program.

I see that I can have lines like

#include <some usual C header>

in those files, and that makes me think that, even if I add no C files
to my .cabal, I still can count on what would be standard C functions
available, and that I could use them with Foreign, like, say:

foreign import ccall "memcpy"
  :: Ptr a -> Ptr a -> CSize -> IO Ptr a

Am I right to guess that? If so, what would be the available set
of functions? I imagined standard C (C99?), but searching around I
see that there are a few different stabdard C libraries, like, for
instance, glibc, which seems to be used in Linux, and a few others.

Supposed I wanted to write a module with all C functions always
available, what could I let be there?

Thanks,
Maurício