On Wed, Oct 05 2022, Junio C Hamano wrote:
> Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> writes:
>
>> But I don't get it in this case, why not just:
>>
>> diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
>> index 4e97817fba5..f9645a9d0df 100644
>> --- a/builtin/bisect--helper.c
>> +++ b/builtin/bisect--helper.c
>> @@ -763,11 +763,9 @@ static enum bisect_error bisect_start(struct bisect_terms *terms, const char **a
>> strbuf_read_file(&start_head, git_path_bisect_start(), 0);
>> strbuf_trim(&start_head);
>> if (!no_checkout) {
>> - struct strvec argv = STRVEC_INIT;
>> + const char *argv[] = { "checkout", start_head.buf, "--", NULL };
>>
>> - strvec_pushl(&argv, "checkout", start_head.buf,
>> - "--", NULL);
>> - if (run_command_v_opt(argv.v, RUN_GIT_CMD)) {
>> + if (run_command_v_opt(argv, RUN_GIT_CMD)) {
>> res = error(_("checking out '%s' failed."
>> " Try 'git bisect start "
>> "<valid-branch>'."),
>>
>> The common pattern for run_command_v_opt() callers that don't need a
>> dynamic list is exactly that.
>
> I think you answered it yourself. start_head.buf is not known at
> compilation time, and there may be some superstition (it may not be
> a mere superstition, but conservatism) about older compiler not
> grokking it.
I think we're thoroughly past that hump as we have a hard requirement on
designated initializers.
Anyway, I believe GCC's -std=c89 wtith -pedantic catches this, e.g. for
bisect--helper.c (the latter is the above patch):
$ make -k git-objs CFLAGS=-std=c89 2>&1|grep 'initializer element is not computable at load time'|grep bisect
builtin/bisect--helper.c:534:43: error: initializer element is not computable at load time [-Werror=pedantic]
builtin/bisect--helper.c:768:60: error: initializer element is not computable at load time [-Werror=pedantic]
For the former we've had:
static int prepare_revs(struct bisect_terms *terms, struct rev_info *revs)
[...]
struct add_bisect_ref_data cb = { revs };
In the same file since 517ecb3161d (bisect--helper: reimplement
`bisect_next` and `bisect_auto_next` shell functions in C, 2020-09-24).
Other prior art, just taking the char[] ones (and not even all of them):
builtin/merge-index.c:12:37: error: initializer element is not computable at load time [-Werror=pedantic]
12 | const char *arguments[] = { pgm, "", "", "", path, "", "", "", NULL };
builtin/remote.c:95:41: error: initializer element is not computable at load time [-Werror=pedantic]
95 | const char *argv[] = { "fetch", name, NULL, NULL };
archive.c:408:33: error: initializer element is not computable at load time [-Werror=pedantic]
408 | const char *paths[] = { path, NULL };
merge-ort.c:1699:45: error: initializer element is not computable at load time [-Werror=pedantic]
1699 | "--all", merged_revision, NULL };
So I think we can safely use this.
