[PATCH v6 13/18] reftable/basics: stop using `SWAP()` macro
- From
Patrick Steinhardt <ps@pks.im>
- Date
- Feb 18, 2025, 09:20 UTC
- Message-ID
- <20250218-pks-reftable-drop-git-compat-util-v6-13-8c1f39fb4c02@pks.im>
- In-Reply-To
- <20250218-pks-reftable-drop-git-compat-util-v6-0-8c1f39fb4c02@pks.im>
Stop using `SWAP()` macro in favor of an open-coded variant of it. Note that this also requires us to open-code the build assert that `SWAP()` itself uses to verify that the size of both variables matches.
This is done to reduce our dependency on the Git codebase.
Signed-off-by: Patrick Steinhardt <ps@pks.im> --- reftable/basics.h | 9 +++++++++ reftable/merged.c | 2 +- reftable/pq.c | 4 ++-- reftable/record.c | 16 ++++++++-------- 4 files changed, 20 insertions(+), 11 deletions(-)
diff --git a/reftable/basics.h b/reftable/basics.h index c1ddbaec3ff..59000798f0b 100644 --- a/reftable/basics.h +++ b/reftable/basics.h @@ -266,6 +266,15 @@ static inline void *reftable_alloc_grow(void *p, size_t nelem, size_t elsize, # define strdup(str) REFTABLE_BANNED(strdup) #endif +#define REFTABLE_SWAP(a, b) do { \ + void *_swap_a_ptr = &(a); \ + void *_swap_b_ptr = &(b); \ + unsigned char _swap_buffer[sizeof(a) - 2 * sizeof(a) * (sizeof(a) != sizeof(b))]; \ + memcpy(_swap_buffer, _swap_a_ptr, sizeof(a)); \ + memcpy(_swap_a_ptr, _swap_b_ptr, sizeof(a)); \ + memcpy(_swap_b_ptr, _swap_buffer, sizeof(a)); \ +} while (0) + /* Find the longest shared prefix size of `a` and `b` */ size_t common_prefix_size(struct reftable_buf *a, struct reftable_buf *b); diff --git a/reftable/merged.c b/reftable/merged.c index 563864068c1..4ff1553772a 100644 --- a/reftable/merged.c +++ b/reftable/merged.c @@ -155,7 +155,7 @@ static int merged_iter_next_entry(struct merged_iter *mi, } mi->advance_index = entry.index; - SWAP(*rec, *entry.rec); + REFTABLE_SWAP(*rec, *entry.rec); return 0; } diff --git a/reftable/pq.c b/reftable/pq.c index ef8035cfd9b..82394a972db 100644 --- a/reftable/pq.c +++ b/reftable/pq.c @@ -57,7 +57,7 @@ int merged_iter_pqueue_remove(struct merged_iter_pqueue *pq, struct pq_entry *ou if (min == i) break; - SWAP(pq->heap[i], pq->heap[min]); + REFTABLE_SWAP(pq->heap[i], pq->heap[min]); i = min; } @@ -81,7 +81,7 @@ int merged_iter_pqueue_add(struct merged_iter_pqueue *pq, const struct pq_entry size_t j = (i - 1) / 2; if (pq_less(&pq->heap[j], &pq->heap[i])) break; - SWAP(pq->heap[j], pq->heap[i]); + REFTABLE_SWAP(pq->heap[j], pq->heap[i]); i = j; } diff --git a/reftable/record.c b/reftable/record.c index 3552bafa994..9a1edf39a02 100644 --- a/reftable/record.c +++ b/reftable/record.c @@ -237,11 +237,11 @@ static int reftable_ref_record_copy_from(void *rec, const void *src_rec, size_t refname_cap = 0; int err; - SWAP(refname, ref->refname); - SWAP(refname_cap, ref->refname_cap); + REFTABLE_SWAP(refname, ref->refname); + REFTABLE_SWAP(refname_cap, ref->refname_cap); reftable_ref_record_release(ref); - SWAP(ref->refname, refname); - SWAP(ref->refname_cap, refname_cap); + REFTABLE_SWAP(ref->refname, refname); + REFTABLE_SWAP(ref->refname_cap, refname_cap); if (src->refname) { size_t refname_len = strlen(src->refname); @@ -376,11 +376,11 @@ static int reftable_ref_record_decode(void *rec, struct reftable_buf key, return n; string_view_consume(&in, n); - SWAP(refname, r->refname); - SWAP(refname_cap, r->refname_cap); + REFTABLE_SWAP(refname, r->refname); + REFTABLE_SWAP(refname_cap, r->refname_cap); reftable_ref_record_release(r); - SWAP(r->refname, refname); - SWAP(r->refname_cap, refname_cap); + REFTABLE_SWAP(r->refname, refname); + REFTABLE_SWAP(r->refname_cap, refname_cap); REFTABLE_ALLOC_GROW_OR_NULL(r->refname, key.len + 1, r->refname_cap); if (!r->refname) {
-- 2.48.1.666.gff9fcf71b7.dirty