tree 3935c829fb31d6a8706e2ed506920ff82423c303
parent 65e0edc73fa921632641463f82a7df2fa15ad7d8
author Vadim Yanitskiy <vyanitskiy@sysmocom.de> 1677236413 +0700
committer fixeria <vyanitskiy@sysmocom.de> 1677491926 +0000

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