Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> writes: > In a preceding commit we created "builtin/submodule.c" and faithfully > tried to reproduce every aspect of "git-submodule.sh", including its > invocation of "git submodule--helper" as a sub-process. > > Let's do away with the sub-process and invoke > "cmd_submodule__helper()" directly. Eventually we'll want to do away > with "builtin/submodule--helper.c" altogether, but let's not do that > for now to avoid conflicts with other in-flight topics. Even without > those conflicts the resulting diff would be large. We can leave that > for a later cleanup. Thanks! e.g. this managed to avoid conflicts with my newly sent out "submodule clone with branches" v2 [1] [1] https://lore.kernel.org/git/pull.1321.v2.git.git.1666297238.gitgitgadget@xxxxxxxxx > It's also worth noting that some users were using e.g. "git > submodule--helper list" directly for performance reasons[2]. With > 31955475d1c (submodule--helper: remove unused "list" helper, > 2022-09-01) released with v2.38.0 the "list" command was no longer > provided. [...] > I think it would make sense to implement a "--format" option for "git > submodule foreach" to help anyone who cares about that remaining > performance (and to improve the API, e.g. by supporting "-z"), but as > far as performance goes this makes the runtime acceptable again. FWIW, I don't think that dropping "git submodule--helper list" was a mistake, since all of "git submodule--helper" was meant to be internal anyway. But if users find it useful, we could add actually supported functionality like what you propose here. > The pattern in "cmd_submodule_builtin()" of saving "struct strvec" > arguments to a "struct string_list" and free()-ing them after the > "argv" has been modified by "cmd_submodule__helper()" is new, without > it we'd get various already-passing tests failing under SANITIZE=leak. [...] > +static int cmd_submodule_builtin(struct strvec *args, const char *prefix) > +{ > + size_t i; > + struct string_list to_free = STRING_LIST_INIT_DUP; > + int ret; > + > + /* > + * The cmd_submodule__helper() will treat the argv as > + * its own and modify it, so e.g. for "git submodule > + * add" the "add" argument will be removed, and we'll > + * thus leak from the strvec_push()'s in > + * setup_helper_args(). > + * > + * So in lieu of some generic "snapshot for a free" > + * API for "struct strvec" squirrel away the pointers > + * to free with string_list_clear() later. > + */ > + for (i = 0; i < args->nr; i++) > + string_list_append_nodup(&to_free, (char *)args->v[i]); > + > + ret = cmd_submodule__helper(args->nr, args->v, prefix); > + > + string_list_clear(&to_free, 0); Hm, so this trick works because we init STRING_LIST_INIT_DUP to make the string_list think that it owns its strings, but when we append, we use string_list_append_nodup(), which doesn't dup the strings. This 'moves' the strings into the string_list and causes them to be freed when we call string_list_clear(). Sounds reasonable enough to me, but I'm not an expert on leaks :) > + free(strvec_detach(args)); > + > + return ret; > +} > + > int cmd_submodule(int argc, const char **argv, const char *prefix) > { > int opt_quiet = 0; > int opt_cached = 0; > int opt_recursive = 0; > - struct child_process cp = CHILD_PROCESS_INIT; > + struct strvec args = STRVEC_INIT; > struct option options[] = { > OPT__QUIET(&opt_quiet, N_("be quiet")), > OPT_BOOL(0, "cached", &opt_cached, > @@ -141,13 +169,10 @@ int cmd_submodule(int argc, const char **argv, const char *prefix) > * Tell the rest of git that any URLs we get don't come > * directly from the user, so it can apply policy as appropriate. > */ > - strvec_push(&cp.env, "GIT_PROTOCOL_FROM_USER=0"); > - setup_helper_args(argc, argv, prefix, opt_quiet, opt_cached, > - opt_recursive, &cp.args, options); > + xsetenv("GIT_PROTOCOL_FROM_USER", "0", 1); > > - cp.git_cmd = 1; > - cp.no_stdin = 0; /* for git submodule foreach */ > - cp.dir = startup_info->original_cwd; > + setup_helper_args(argc, argv, prefix, opt_quiet, opt_cached, > + opt_recursive, &args, options); > > - return run_command(&cp); > + return cmd_submodule_builtin(&args, prefix); > } > -- > 2.38.0.1091.gf9d18265e59
