reftable: introduce macros to allocate arrays

Similar to the preceding commit, let's carry over macros to allocate
arrays with `REFTABLE_ALLOC_ARRAY()` and `REFTABLE_CALLOC_ARRAY()`. This
requires us to change the signature of `reftable_calloc()`, which only
takes a single argument right now and thus puts the burden on the caller
to calculate the final array's size. This is a net improvement though as
it means that we can now provide proper overflow checks when multiplying
the array size with the member size.

Convert callsites of `reftable_calloc()` to the new signature and start
using the new macros where possible.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/reftable/blocksource.c b/reftable/blocksource.c
index 8c41e3c70f..eeed254ba9 100644
--- a/reftable/blocksource.c
+++ b/reftable/blocksource.c
@@ -29,7 +29,7 @@ static int strbuf_read_block(void *v, struct reftable_block *dest, uint64_t off,
 {
 	struct strbuf *b = v;
 	assert(off + size <= b->len);
-	dest->data = reftable_calloc(size);
+	REFTABLE_CALLOC_ARRAY(dest->data, size);
 	memcpy(dest->data, b->buf + off, size);
 	dest->len = size;
 	return size;
@@ -132,7 +132,7 @@ int reftable_block_source_from_file(struct reftable_block_source *bs,
 		return REFTABLE_IO_ERROR;
 	}
 
-	p = reftable_calloc(sizeof(*p));
+	REFTABLE_CALLOC_ARRAY(p, 1);
 	p->size = st.st_size;
 	p->data = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
 	close(fd);