Re: [PATCH 2/2] alloca.3: rewrite NOTES

["Alejandro Colomar (man-pages)" <alx.manpages@gmail.com>]

Hi, Ahelenia!

On 8/24/21 12:33 PM, Alejandro Colomar (man-pages) wrote:
> 
> And apart from what Michael (and Branden) already said, I have one 
> question that has not been treated before it seems:
> 
> AFAIK, VLAs are 100% equivalent to alloca() (except for the obvious 
> syntax differences).  And considering the VLA syntax is much nicer than 
> alloca(), and is in the standard (IIRC, C99 added VLAs, and C11 declared 
> them optional), what about adding a NOTES subsection that recommends (or 
> at least mentions) VLAs?
> 
> And they both share the problem of smashing the stack if you try to 
> allocate an array to big (and none of them has a way to check if it will 
> happen, AFAIK).

Now that I think, there's a slight difference, of course:  VLAs live in 
their block scope, while alloca() lives in the function scope, allowing 
to embed it in a macro such as strdupa().

But maybe still worth mentioning VLAs in alloca(3).

Cheers,

Alex


-- 
Alejandro Colomar
Linux man-pages comaintainer; https://www.kernel.org/doc/man-pages/
http://www.alejandro-colomar.es/