> Does anyone else think having __libc_read, __libc_write etc would be
> handy?

Maybe, though I have trouble imagining what could reasonably use them.

But mainly,

> It would be nice to be able to use something like
> -D_LIB_ENTRY_LABEL=__libc_ or whatever, but I've not worked out how
> to get that to work - I get either "__libc_ read" or
> "_LIB_ENTRY_LABELread"

I snipped out of your patch enough to play with, and find this works
for me with -DPREFIX=whatever.  I hope you can adapt it.  (I had to
diddle with it a little to make it suitable for direct cc -E runs, such
as the first #define.)

#define _LIBC

#ifdef __STDC__
# define __CONCAT(x,y) x ## y
# define __STRING(x)   #x
#else
# define __CONCAT(x,y) x/**/y
# define __STRING(x)   "x"
#endif

#define __CONCATDEFER(x,y) __CONCAT(x,y)

#if defined(_LIBC)
#define ENTRY(name)            _ENTRY(_C_LABEL(__CONCATDEFER(PREFIX,name)));_ENTRY(_C_LABEL(name)); _PROF_PROLOGUE
#else
#define ENTRY(name)            _ENTRY(_C_LABEL(name)); _PROF_PROLOGUE
#endif

ENTRY(read)

					der Mouse

			       mouse@rodents.montreal.qc.ca
		     7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B