*.c *_init(): define in terms of corresponding *_INIT macro

Change the common patter in the codebase of duplicating the
initialization logic between an *_INIT macro and a
corresponding *_init() function to use the macro as the canonical
source of truth.

Now we no longer need to keep the function up-to-date with the macro
version. This implements a suggestion by Jeff King who found that
under -O2 [1] modern compilers will init new version in place without
the extra copy[1]. The performance of a single *_init() won't matter
in most cases, but even if it does we're going to be producing
efficient machine code to perform these operations.

1. https://lore.kernel.org/git/YNyrDxUO1PlGJvCn@coredump.intra.peff.net/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Ævar Arnfjörð Bjarmason 2021-07-01 12:51:26 +02:00 committed by Junio C Hamano
parent 3d97ea479f
commit 5726a6b401
6 changed files with 12 additions and 15 deletions

View File

@ -10,8 +10,8 @@
void credential_init(struct credential *c)
{
memset(c, 0, sizeof(*c));
c->helpers.strdup_strings = 1;
struct credential blank = CREDENTIAL_INIT;
memcpy(c, &blank, sizeof(*c));
}
void credential_clear(struct credential *c)

View File

@ -3,10 +3,8 @@
void jw_init(struct json_writer *jw)
{
strbuf_init(&jw->json, 0);
strbuf_init(&jw->open_stack, 0);
jw->need_comma = 0;
jw->pretty = 0;
struct json_writer blank = JSON_WRITER_INIT;
memcpy(jw, &blank, sizeof(*jw));;
}
void jw_release(struct json_writer *jw)

View File

@ -11,9 +11,8 @@
void child_process_init(struct child_process *child)
{
memset(child, 0, sizeof(*child));
strvec_init(&child->args);
strvec_init(&child->env_array);
struct child_process blank = CHILD_PROCESS_INIT;
memcpy(child, &blank, sizeof(*child));
}
void child_process_clear(struct child_process *child)

View File

@ -52,8 +52,8 @@ char strbuf_slopbuf[1];
void strbuf_init(struct strbuf *sb, size_t hint)
{
sb->alloc = sb->len = 0;
sb->buf = strbuf_slopbuf;
struct strbuf blank = STRBUF_INIT;
memcpy(sb, &blank, sizeof(*sb));
if (hint)
strbuf_grow(sb, hint);
}

View File

@ -25,7 +25,8 @@ static struct strmap_entry *find_strmap_entry(struct strmap *map,
void strmap_init(struct strmap *map)
{
strmap_init_with_options(map, NULL, 1);
struct strmap blank = STRMAP_INIT;
memcpy(map, &blank, sizeof(*map));
}
void strmap_init_with_options(struct strmap *map,

View File

@ -6,9 +6,8 @@ const char *empty_strvec[] = { NULL };
void strvec_init(struct strvec *array)
{
array->v = empty_strvec;
array->nr = 0;
array->alloc = 0;
struct strvec blank = STRVEC_INIT;
memcpy(array, &blank, sizeof(*array));
}
static void strvec_push_nodup(struct strvec *array, const char *value)