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. Aside from that: $ man talloc (on NonStop) No manual entry for talloc (on Cygwin) No manual entry for talloc Just reporting my findings.
