From dc13f40c6ba291e31d09053815c230ed88c8921f Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Wed, 13 Jan 2021 16:10:11 -0600 Subject: [PATCH] qapi: Introduce QAPI_LIST_APPEND Similar to the existing QAPI_LIST_PREPEND, but designed for use where we want to preserve insertion order. Callers will be added in upcoming patches. Note the difference in signature: PREPEND takes List*, APPEND takes List**. Signed-off-by: Eric Blake Reviewed-by: Vladimir Sementsov-Ogievskiy Message-Id: <20210113221013.390592-4-eblake@redhat.com> Reviewed-by: Markus Armbruster Signed-off-by: Markus Armbruster --- include/qapi/util.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/include/qapi/util.h b/include/qapi/util.h index 6178e98e97..d7bfb30e25 100644 --- a/include/qapi/util.h +++ b/include/qapi/util.h @@ -37,4 +37,17 @@ int parse_qapi_name(const char *name, bool complete); (list) = _tmp; \ } while (0) +/* + * For any pointer to a GenericList @tail (usually the 'next' member of a + * list element), insert @element at the back and update the tail. + * + * Note that this macro evaluates @element exactly once, so it is safe + * to have side-effects with that argument. + */ +#define QAPI_LIST_APPEND(tail, element) do { \ + *(tail) = g_malloc0(sizeof(**(tail))); \ + (*(tail))->value = (element); \ + (tail) = &(*(tail))->next; \ +} while (0) + #endif