fixeria has uploaded this change for review. ( https://gerrit.osmocom.org/c/libosmocore/+/31494 )

Change subject: msgb: use OSMO_ASSERT in msgb_alloc_headroom[_c]() ......................................................................

msgb: use OSMO_ASSERT in msgb_alloc_headroom[_c]()

This patch is a preparation for the upcoming change making use of the built-in static_assert(), which is available since C11.

When using built-in static_assert(), gcc v12.2.1 fails:

include/osmocom/core/msgb.h: In function 'msgb_alloc_headroom_c': include/osmocom/core/msgb.h:532:33: error: expression in static assertion is not constant 532 | osmo_static_assert(size >= headroom, headroom_bigger); include/osmocom/core/utils.h:86:24: note: in definition of macro 'osmo_static_assert' 86 | static_assert((exp), "(" #exp ") failed") | ^~~ include/osmocom/core/msgb.h: In function 'msgb_alloc_headroom': include/osmocom/core/msgb.h:554:33: error: expression in static assertion is not constant 554 | osmo_static_assert(size >= headroom, headroom_bigger); include/osmocom/core/utils.h:86:24: note: in definition of macro 'osmo_static_assert' 86 | static_assert((exp), "(" #exp ") failed") | ^~~

These are not really *static* assert()s, because they operate on the user supplied arguments 'size' and 'headroom', which are not guaranteed to be integer literals. Neither they trigger compilation failures as expected, nor do they abort at run-time. They simply do nothing.

Change-Id: I17ef4f3283ce20a5b452b7874c826acfb02a0123 --- M include/osmocom/core/msgb.h 1 file changed, 34 insertions(+), 2 deletions(-)

git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/94/31494/1

diff --git a/include/osmocom/core/msgb.h b/include/osmocom/core/msgb.h index 3fdb189..2529c0e 100644 --- a/include/osmocom/core/msgb.h +++ b/include/osmocom/core/msgb.h @@ -529,7 +529,7 @@ static inline struct msgb *msgb_alloc_headroom_c(const void *ctx, uint16_t size, uint16_t headroom, const char *name) { - osmo_static_assert(size >= headroom, headroom_bigger); + OSMO_ASSERT(size >= headroom);

struct msgb *msg = msgb_alloc_c(ctx, size, name); if (OSMO_LIKELY(msg)) @@ -551,7 +551,7 @@ static inline struct msgb *msgb_alloc_headroom(uint16_t size, uint16_t headroom, const char *name) { - osmo_static_assert(size >= headroom, headroom_bigger); + OSMO_ASSERT(size >= headroom);

struct msgb *msg = msgb_alloc(size, name); if (OSMO_LIKELY(msg))