Hi Ævar
On 08/07/2022 15:20, Ævar Arnfjörð Bjarmason wrote:
Add "gently" versions of ALLOC_ARRAY(), CALLOC_ARRAY() etc. using the
naming convention G*() as a shorthand for "GENTLY_*()".
It might be nicer just to call them ALLOC_ARRAY_GENTLY() etc. As the
return value needs to be checked it would make sense to implement them
as expressions as I have done for XDL_ALLOC_ARRAY() etc.
Nothing uses these functions yet, but as we'll see in subsequent
commit(s) we're able to convert things that need e.g. non-fatal
"ALLOC_GROW" behavior over to this.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
---
git-shared-util.h | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/git-shared-util.h b/git-shared-util.h
index 7b4479a0f72..718a8e00732 100644
--- a/git-shared-util.h
+++ b/git-shared-util.h
@@ -8,8 +8,11 @@
#define FREE_AND_NULL(p) do { free(p); (p) = NULL; } while (0)
#define ALLOC_ARRAY(x, alloc) (x) = xmalloc(st_mult(sizeof(*(x)), (alloc)))
+#define GALLOC_ARRAY(x, alloc) (x) = malloc(st_mult(sizeof(*(x)), (alloc)))
#define CALLOC_ARRAY(x, alloc) (x) = xcalloc((alloc), sizeof(*(x)))
+#define GCALLOC_ARRAY(x, alloc) (x) = calloc((alloc), sizeof(*(x)))
#define REALLOC_ARRAY(x, alloc) (x) = xrealloc((x), st_mult(sizeof(*(x)), (alloc)))
+#define GREALLOC_ARRAY(x, alloc) (x) = realloc((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))))
@@ -71,17 +74,25 @@ static inline void move_array(void *dst, const void *src, size_t n, size_t size)
* added niceties.
*
* DO NOT USE any expression with side-effect for 'x', 'nr', or 'alloc'.
+ *
+ * GALLOC_GROW() behaves like ALLOC_GROW(), except that in malloc()
+ * failure we'll return NULL rather than dying.
*/
-#define ALLOC_GROW(x, nr, alloc) \
+#define ALLOC_GROW_1(x, nr, alloc, gently) \
do { \
if ((nr) > alloc) { \
if (alloc_nr(alloc) < (nr)) \
alloc = (nr); \
else \
alloc = alloc_nr(alloc); \
- REALLOC_ARRAY(x, alloc); \
This leaks the old allocation if realloc() fails because it overwrites
the original pointer with NULL, that is particularly bad as if realloc()
fails we're already short of memory. XDL_ALLOC_GROW() shows how a
possible way to do this.
Best Wishes
Phillip
+ if (gently) \
+ GREALLOC_ARRAY(x, alloc); \
+ else \
+ REALLOC_ARRAY(x, alloc); \
} \
} while (0)
+#define ALLOC_GROW(x, nr, alloc) ALLOC_GROW_1(x, nr, alloc, 0)
+#define GALLOC_GROW(x, nr, alloc) ALLOC_GROW_1(x, nr, alloc, 1)
/*
* Similar to ALLOC_GROW but handles updating of the nr value and
