reftable/basics: stop using `SWAP()` macro
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> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Patrick Steinhardt committed
Feb 18, 2025 at 10:20 UTC
f8ed12dec459df9ea0d43ccacc93cb2c32702c0e
4 files changed
+20
-11
reftable/basics.h
+9
@@ -266,6 +266,15 @@ static inline void *reftable_alloc_grow(void *p, size_t nelem, size_t elsize,
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# define strdup(str) REFTABLE_BANNED(strdup)
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#endif
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+#define REFTABLE_SWAP(a, b) do { \
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+ void *_swap_a_ptr = &(a); \
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+ void *_swap_b_ptr = &(b); \
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+ unsigned char _swap_buffer[sizeof(a) - 2 * sizeof(a) * (sizeof(a) != sizeof(b))]; \
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+ memcpy(_swap_buffer, _swap_a_ptr, sizeof(a)); \
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+ memcpy(_swap_a_ptr, _swap_b_ptr, sizeof(a)); \
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+ memcpy(_swap_b_ptr, _swap_buffer, sizeof(a)); \
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+} while (0)
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+
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/* Find the longest shared prefix size of `a` and `b` */
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size_t common_prefix_size(struct reftable_buf *a, struct reftable_buf *b);
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reftable/merged.c
+1
-1
@@ -155,7 +155,7 @@ static int merged_iter_next_entry(struct merged_iter *mi,
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}
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mi->advance_index = entry.index;
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- SWAP(*rec, *entry.rec);
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+ REFTABLE_SWAP(*rec, *entry.rec);
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return 0;
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}
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reftable/pq.c
+2
-2
@@ -57,7 +57,7 @@ int merged_iter_pqueue_remove(struct merged_iter_pqueue *pq, struct pq_entry *ou
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if (min == i)
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break;
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- SWAP(pq->heap[i], pq->heap[min]);
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+ REFTABLE_SWAP(pq->heap[i], pq->heap[min]);
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i = min;
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}
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@@ -81,7 +81,7 @@ int merged_iter_pqueue_add(struct merged_iter_pqueue *pq, const struct pq_entry
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size_t j = (i - 1) / 2;
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if (pq_less(&pq->heap[j], &pq->heap[i]))
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break;
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- SWAP(pq->heap[j], pq->heap[i]);
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+ REFTABLE_SWAP(pq->heap[j], pq->heap[i]);
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i = j;
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}
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reftable/record.c
+8
-8
@@ -237,11 +237,11 @@ static int reftable_ref_record_copy_from(void *rec, const void *src_rec,
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size_t refname_cap = 0;
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int err;
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- SWAP(refname, ref->refname);
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- SWAP(refname_cap, ref->refname_cap);
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+ REFTABLE_SWAP(refname, ref->refname);
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+ REFTABLE_SWAP(refname_cap, ref->refname_cap);
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reftable_ref_record_release(ref);
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- SWAP(ref->refname, refname);
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- SWAP(ref->refname_cap, refname_cap);
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+ REFTABLE_SWAP(ref->refname, refname);
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+ REFTABLE_SWAP(ref->refname_cap, refname_cap);
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if (src->refname) {
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size_t refname_len = strlen(src->refname);
@@ -376,11 +376,11 @@ static int reftable_ref_record_decode(void *rec, struct reftable_buf key,
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return n;
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string_view_consume(&in, n);
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- SWAP(refname, r->refname);
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- SWAP(refname_cap, r->refname_cap);
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+ REFTABLE_SWAP(refname, r->refname);
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+ REFTABLE_SWAP(refname_cap, r->refname_cap);
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reftable_ref_record_release(r);
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- SWAP(r->refname, refname);
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- SWAP(r->refname_cap, refname_cap);
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+ REFTABLE_SWAP(r->refname, refname);
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+ REFTABLE_SWAP(r->refname_cap, refname_cap);
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REFTABLE_ALLOC_GROW_OR_NULL(r->refname, key.len + 1, r->refname_cap);
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if (!r->refname) {