Merge branch 'rs/copy-array' into maint

Code cleanup.

* rs/copy-array:
  use COPY_ARRAY
  add COPY_ARRAY

7 files changed, 40 insertions, 9 deletions

diff --git a/builtin/mv.c b/builtin/mv.c
index 446a316738..2f43877bc9 100644
--- a/builtin/mv.c
+++ b/builtin/mv.c
@@ -26,7 +26,7 @@ static const char **internal_copy_pathspec(const char *prefix,
 	int i;
 	const char **result;
 	ALLOC_ARRAY(result, count + 1);
-	memcpy(result, pathspec, count * sizeof(const char *));
+	COPY_ARRAY(result, pathspec, count);
 	result[count] = NULL;
 	for (i = 0; i < count; i++) {
 		int length = strlen(result[i]);
diff --git a/commit.c b/commit.c
index ba6dee37aa..aada266f9a 100644
--- a/commit.c
+++ b/commit.c
@@ -931,7 +931,7 @@ static int remove_redundant(struct commit **array, int cnt)
 	}
 
 	/* Now collect the result */
-	memcpy(work, array, sizeof(*array) * cnt);
+	COPY_ARRAY(work, array, cnt);
 	for (i = filled = 0; i < cnt; i++)
 		if (!redundant[i])
 			array[filled++] = work[i];
diff --git a/contrib/coccinelle/array.cocci b/contrib/coccinelle/array.cocci
new file mode 100644
index 0000000000..2d7f25d99f
--- /dev/null
+++ b/contrib/coccinelle/array.cocci
@@ -0,0 +1,26 @@
+@@
+type T;
+T *dst;
+T *src;
+expression n;
+@@
+- memcpy(dst, src, n * sizeof(*dst));
++ COPY_ARRAY(dst, src, n);
+
+@@
+type T;
+T *dst;
+T *src;
+expression n;
+@@
+- memcpy(dst, src, n * sizeof(*src));
++ COPY_ARRAY(dst, src, n);
+
+@@
+type T;
+T *dst;
+T *src;
+expression n;
+@@
+- memcpy(dst, src, n * sizeof(T));
++ COPY_ARRAY(dst, src, n);
diff --git a/git-compat-util.h b/git-compat-util.h
index 2c949983dc..aec8cc9890 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -798,6 +798,14 @@ extern FILE *fopen_for_writing(const char *path);
 #define ALLOC_ARRAY(x, alloc) (x) = xmalloc(st_mult(sizeof(*(x)), (alloc)))
 #define REALLOC_ARRAY(x, alloc) (x) = xrealloc((x), st_mult(sizeof(*(x)), (alloc)))
 
+#define COPY_ARRAY(dst, src, n) copy_array((dst), (src), (n), sizeof(*(dst)) + \
+	BUILD_ASSERT_OR_ZERO(sizeof(*(dst)) == sizeof(*(src))))
+static inline void copy_array(void *dst, const void *src, size_t n, size_t size)
+{
+	if (n)
+		memcpy(dst, src, st_mult(size, n));
+}
+
 /*
  * These functions help you allocate structs with flex arrays, and copy
  * the data directly into the array. For example, if you had:
diff --git a/pack-revindex.c b/pack-revindex.c
index 96d51c3467..6bc7c94033 100644
--- a/pack-revindex.c
+++ b/pack-revindex.c
@@ -107,7 +107,7 @@ static void sort_revindex(struct revindex_entry *entries, unsigned n, off_t max)
 	 * we have to move it back from the temporary storage.
 	 */
 	if (from != entries)
-		memcpy(entries, tmp, n * sizeof(*entries));
+		COPY_ARRAY(entries, tmp, n);
 	free(tmp);
 	free(pos);
 
diff --git a/pathspec.c b/pathspec.c
index 24e0dd5232..49a53607bb 100644
--- a/pathspec.c
+++ b/pathspec.c
@@ -485,8 +485,7 @@ void copy_pathspec(struct pathspec *dst, const struct pathspec *src)
 {
 	*dst = *src;
 	ALLOC_ARRAY(dst->items, dst->nr);
-	memcpy(dst->items, src->items,
-	       sizeof(struct pathspec_item) * dst->nr);
+	COPY_ARRAY(dst->items, src->items, dst->nr);
 }
 
 void clear_pathspec(struct pathspec *pathspec)
diff --git a/split-index.c b/split-index.c
index 3c75d4b9ce..35da553655 100644
--- a/split-index.c
+++ b/split-index.c
@@ -83,8 +83,7 @@ void move_cache_to_base_index(struct index_state *istate)
 	si->base->timestamp = istate->timestamp;
 	ALLOC_GROW(si->base->cache, istate->cache_nr, si->base->cache_alloc);
 	si->base->cache_nr = istate->cache_nr;
-	memcpy(si->base->cache, istate->cache,
-	       sizeof(*istate->cache) * istate->cache_nr);
+	COPY_ARRAY(si->base->cache, istate->cache, istate->cache_nr);
 	mark_base_index_entries(si->base);
 	for (i = 0; i < si->base->cache_nr; i++)
 		si->base->cache[i]->ce_flags &= ~CE_UPDATE_IN_BASE;
@@ -141,8 +140,7 @@ void merge_base_index(struct index_state *istate)
 	istate->cache	    = NULL;
 	istate->cache_alloc = 0;
 	ALLOC_GROW(istate->cache, istate->cache_nr, istate->cache_alloc);
-	memcpy(istate->cache, si->base->cache,
-	       sizeof(*istate->cache) * istate->cache_nr);
+	COPY_ARRAY(istate->cache, si->base->cache, istate->cache_nr);
 
 	si->nr_deletions = 0;
 	si->nr_replacements = 0;