Le jeu. 13 mai 2021 à 01:04, Joerg Sonnenberger <jo...@bec.de> a écrit : > > On Wed, May 12, 2021 at 08:32:20PM +0200, Jaromír Doleček wrote: > > Le mer. 12 mai 2021 à 13:50, Joerg Sonnenberger <jo...@bec.de> a écrit : > > > > > > On Wed, May 12, 2021 at 08:38:39AM +0200, Jaromír Doleček wrote: > > > > would it be a bad thing to add a compatibility <alloca.h> which would > > > > use the builtin alloca() instead of the libc one when available? > > > > > > > > e.g. MySQL 8.0.* seems to rely on this. > > > > > > We provide it in stdlib.h as long as a standard mode is not set. > > > I don't see the point of adding alloca.h. > > > > We don't provide the builtin in stdlib.h. > > Yes, we do.
No we don't, unless you are using PCC :D The block in <stdlib.h> only provides an alloca(3) prototype, and only if the compiler already #defines alloca as __builtin_alloca. While this works for gcc in some -std modes (e.g. gnu++14), it does not in others (c++14, c++11). On the contrary, Linux <alloca.h> explicitely #undefs alloca(), then #define alloca() as __builtin_alloca(), so it always works, regardless which -std. Jaromir
