On Thu, Jul 18, 2024 at 11:09:40PM GMT, Bruno Haible wrote: > Hi Alejandro,
Hi Bruno, > > strtol(3) has a limited set of possible states: > > ... > > The condition '*endp != s && errno != 0 && errno != ERANGE' is > > unreachable. The only errno possible if '*endp != s' is ERANGE. > > Such a statement can be true if you look at the standards (ISO C, POSIX). > > However, there's a difference between what the standards say and what the > systems actually do. The Gnulib documentation contains thousands of examples > of such differences. > > Gnulib therefore (almost) never assumes that there are no possible errno > values besides the ones listed in the standards. > - Some systems return "wrong" errno values. Example: [1] > - Some systems fail with ENOMEM when memory is tight. Who says that > an implementation of strtol() cannot use malloc() ? Some implementations > of strtod() do use malloc(). > > So, what you call "dead code", I call "defensive programming". I would not > like to apply this patch. Makes sense. I think we should document that possibility in the manual page. Maybe say that other errno values are possible in some systems? Otherwise, it's already a hell of a function to take care of, and most uses don't handle that possibility at the moment. (Yet more reasons to use a wrapper that returns -1 & sets errno on error, as the rest of libc.) Would you send a patch? (I'd write it myself, but you probably can provide more info in the commit message.) Have a lovely night! Alex > > Bruno > > [1] https://www.gnu.org/software/gnulib/manual/html_node/getlogin_005fr.html > > > -- <https://www.alejandro-colomar.es/>
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