Re: [PATCH 07/18] convert trivial cases to FLEX_ARRAY macros
From: Eric Sunshine <hidden>
Date: 2016-06-15 23:08:15
On Mon, Feb 15, 2016 at 4:52 PM, Jeff King [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Using FLEX_ARRAY macros reduces the amount of manual computation size we have to do. It also ensures we don't overflow size_t, and it makes sure we write the same number of bytes that we allocated. Signed-off-by: Jeff King <redacted> ---diff --git a/builtin/reflog.c b/builtin/reflog.c@@ -412,8 +410,7 @@ static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len) !memcmp(ent->pattern, pattern, len)) return ent; - ent = xcalloc(1, (sizeof(*ent) + len)); - memcpy(ent->pattern, pattern, len); + FLEX_ALLOC_MEM(ent, pattern, pattern, len);
Does the incoming 'len' already account for the NUL terminator, or was the original code underallocating? Answering my own question: Looking at reflog_expire_config() and parse_config_key(), I gather that 'len' already accounts for the NUL, thus the new code is overallocating (which should not be a problem).
quoted hunk ↗ jump to hunk
ent->len = len; *reflog_expire_cfg_tail = ent; reflog_expire_cfg_tail = &(ent->next);diff --git a/hashmap.c b/hashmap.c@@ -256,10 +256,9 @@ const void *memintern(const void *data, size_t len) e = hashmap_get(&map, &key, data); if (!e) { /* not found: create it */ - e = xmallocz(sizeof(struct pool_entry) + len); + FLEX_ALLOC_MEM(e, data, data, len);
Ditto. I guess the new code is overallocating (which should be okay).
hashmap_entry_init(e, key.ent.hash);
e->len = len;
- memcpy(e->data, data, len);
hashmap_add(&map, e);
}
return e->data;