On Thursday, March 23, 2023 7:55 PM, Felipe Contreras wrote: >On Thu, Mar 23, 2023 at 5:43 PM <rsbecker@xxxxxxxxxxxxx> wrote: >> >> On Thursday, March 23, 2023 7:35 PM, Felipe Contreras wrote: >> >On Thu, Mar 23, 2023 at 5:30 PM <rsbecker@xxxxxxxxxxxxx> wrote: >> >> >> >> On Thursday, March 23, 2023 7:22 PM, Felipe Contreras wrote: >> >> >On Sat, Feb 18, 2023 at 5:12 AM Phillip Wood >> >> ><phillip.wood123@xxxxxxxxx> >> >wrote: >> >> >> >> >> >> On 18/02/2023 01:59, demerphq wrote: >> >> >> > On Sat, 18 Feb 2023 at 00:24, Junio C Hamano <gitster@xxxxxxxxx> >wrote: >> >> >> >> >> >> >> >> Emily Shaffer <nasamuffin@xxxxxxxxxx> writes: >> >> >> >> >> >> >> >>> Basically, if this effort turns out not to be fruitful as a >> >> >> >>> whole, I'd like for us to still have left a positive impact on the codebase. >> >> >> >>> ... >> >> >> >>> So what's next? Naturally, I'm looking forward to a spirited >> >> >> >>> discussion about this topic - I'd like to know which >> >> >> >>> concerns haven't been addressed and figure out whether we >> >> >> >>> can find a way around them, and generally build awareness of >> >> >> >>> this effort with the >> >community. >> >> >> >> >> >> >> >> On of the gravest concerns is that the devil is in the details. >> >> >> >> >> >> >> >> For example, "die() is inconvenient to callers, let's >> >> >> >> propagate errors up the callchain" is an easy thing to say, >> >> >> >> but it would take much more than "let's propagate errors up" >> >> >> >> to libify something like >> >> >> >> check_connected() to do the same thing without spawning a >> >> >> >> separate process that is expected to exit with failure. >> >> >> > >> >> >> > >> >> >> > What does "propagate errors up the callchain" mean? One >> >> >> > interpretation I can think of seems quite horrible, but >> >> >> > another seems quite doable and reasonable and likely not even >> >> >> > very invasive of the existing code: >> >> >> > >> >> >> > You can use setjmp/longjmp to implement a form of "try", so >> >> >> > that errors dont have to be *explicitly* returned *in* the call chain. >> >> >> > And you could probably do so without changing very much of the >> >> >> > existing code at all, and maintain a high level of conceptual >> >> >> > alignment with the current code strategy. >> >> >> >> >> >> Using setjmp/longjmp is an interesting suggestion, I think lua >> >> >> does something similar to what you describe for perl. However I >> >> >> think both of those use a allocator with garbage collection. I >> >> >> worry that using longjmp in git would be more invasive (or >> >> >> result in more memory leaks) as we'd need to to guard each >> >> >> allocation with some code to clean it up and then propagate the >> >> >> error. That means we're back to manually propagating errors up the call >chain in many cases. >> >> > >> >> >We could just use talloc [1]. >> >> >> >> talloc is not portable. >> > >> >What makes you say that? >> >> talloc is not part of a POSIX standard I could find. > >It's a library, like: z, ssl, curl, pcre2-8, etc. Libraries can be compiled on different >platforms. talloc adds additional *required* dependencies to git, including python3 - required to configure and build talloc - which is not available on the NonStop ia64 platform (required support through end of 2025). I must express my resistance to what would amount to losing support for git on this NonStop platform. --Randall
