Re: [PATCH 4/5] treewide: Spell ASSERT() as assert()

[Stefano Brivio <sbrivio@redhat.com>]

On Mon, 16 Mar 2026 16:46:28 +1100
David Gibson <david@gibson.dropbear.id.au> wrote:

> +++ b/util.h
> @@ -73,10 +73,14 @@ void abort_with_msg(const char *fmt, ...)
>   * Therefore, avoid using the usual do while wrapper we use to force the macro
>   * to act like a single statement requiring a ';'.
>   */
> -#define ASSERT_WITH_MSG(expr, ...)					\
> +#define assert_with_msg(expr, ...)					\
>  	((expr) ? (void)0 : abort_with_msg(__VA_ARGS__))
> -#define ASSERT(expr)							\
> -	ASSERT_WITH_MSG((expr), "ASSERTION FAILED in %s (%s:%d): %s",	\
> +/* The standard library assert() hits our seccomp filter and dies before it can
> + * actually print a message.  So, replace it with our own version.
> + */
> +#undef assert
> +#define assert(expr)							\
> +	assert_with_msg((expr), "ASSERTION FAILED in %s (%s:%d): %s",	\
>  			__func__, __FILE__, __LINE__, STRINGIFY(expr))

While looking this up to make sure it's specified as a macro (it is,
and this builds against musl as well), I realised that POSIX.1-2024
says:

  https://pubs.opengroup.org/onlinepubs/9799919799/functions/assert.html

  Forcing a definition of the name NDEBUG, either from the compiler
  command line or with the preprocessor control statement #define NDEBUG
  ahead of the #include <assert.h> statement, shall stop assertions from
  being compiled into the program.

...so, I wonder, now that it's called assert(), should we define it as
"do { } while(0)" #ifdef NDEBUG, for correctness (and maybe somebody
has obscure usages for NDEBUG which we shouldn't sabotage)?

This will conflict with "[PATCH v2 3/3] vu_common: Move iovec management
into vu_collect()" by the way, but I'll take care of it, if it still
conflicts by the time I merge it.

-- 
Stefano