> Date: Sat, 5 Apr 2025 19:18:20 +0200
> From: Roland Illig <roland.il...@gmx.de>
>
> Would it be narrow enough to add /*CONSTCOND*/ to the definition of
> ALIGNED_POINTER on i386 and amd64? Or would you consider this still too
> broad?
Might be reasonable. But then we have a lot of predicates that might
be used in conditionals but be constant on some architectures, which
raises the question of which ones should be marked.
I wonder how many real bugs -- true positives -- lint's
constant-condition warnings find.
> The next alternative would be to mark each call to ALIGNED_POINTER as
> /*CONSTCOND*/, but that would be additional work in several places.
This reminds me of gcc's infuriating feature where carefully writing
safe bounds checks like
unsigned n = ...;
if (n > SIZE_MAX - sizeof(header))
goto fail;
x = malloc(sizeof(header) + n);
leads to -Wtype-limits failures on architectures where size_t is
64-bit and int is 32-bit, so you have to go to _extra work_ to
conditionalize the perfectly safe idiom, turning it into something
riskier just to pacify the warning, making the warning actively
harmful.
