[PATCH 3/7] git-shared-util.h: add G*() versions of *ALLOC_*()

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Add "gently" versions of ALLOC_ARRAY(), CALLOC_ARRAY() etc. using the
naming convention G*() as a shorthand for "GENTLY_*()".

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@gmail.com>
---
 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); \
+			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
-- 
2.37.0.913.g189dca38629