C99 Features

[Nico Williams]

On Thu, Jun 18, 2015 at 01:13:40AM +0000, Danilo Almeida wrote:
> <quote from="Nico">
> Both are fine when the sizes are naturally limited to small sizes, but
> this requires more review effort.  Alternatively one could have a
> macro to guard against unsafe array sizes.  I'd rather VLAs and
> alloca() were frowned upon (though not forbidden).
> </quote>
> 
> I am not sure how such a macro would work.

A macro could work for alloca:

void *alloca_abort() { abort(); }

#define GUARDED_ALLOCA(requested, max) \
    (requested <= max ? alloca(requested) : alloca_abort())

Obviously there may be other failure handling options.

Nico
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