Extension to the FFI to allow macro expansions to be avoided
fjh at cs.mu.oz.au
Wed Apr 14 14:38:49 EDT 2004
On 13-Apr-2004, Ross Paterson <ross at soi.city.ac.uk> wrote:
> On Tue, Apr 13, 2004 at 11:55:47AM +0100, Simon Marlow wrote:
> > > I'd favour turning off the
> > > macro interface, preferably with #undef, at least by default.
> > Agreed. Why is #undef to be preferred over adding parentheses around
> > the function name as Ian originally suggested?
> It would also switch off
> #define func another_func
> #define errno thread_local_errno()
Why is that preferred? Undefining errno means that it won't work!
As the C standard says:
| It is unspecified whether errno
| is a macro or an identifier declared with external linkage.
| If a macro definition is suppressed in order to access an
| actual object ... the behavior is undefined.
Fergus Henderson | "I have always known that the pursuit
| of excellence is a lethal habit"
WWW: <http://www.cs.mu.oz.au/~fjh> | -- the last words of T. S. Garp.
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