Re: [PATCH v3 4/4] malloc: alignment might change in future versions

[Paul Eggert <eggert@cs.ucla.edu>]

On 2026-02-26 04:47, Florian Weimer wrote:
>> --- a/manual/lang.texi
>> +++ b/manual/lang.texi
>> @@ -597,7 +597,7 @@ types have a fundamental alignment and lack stricter alignment specifiers.
>>   In @theglibc{}, the value of @code{alignof (max_align_t)} is 16 on
>>   most architectures.  However, it is 8 on 32-bit architectures that do
>>   not require 16-byte alignment from @code{malloc} to support predefined
>> -types.
>> +types.  The value may change in future releases.
> Can we really change the definition of the type, though?  That's close
> to an ABI event.
> 
> Rest looks okay to me.

Thanks, I installed the patches without that sentence.

However, the manual should discuss the ABI effect of any possible 
differences in max_align_t, or in intmax_t/uintmax_t for that matter. 
This is relevant partly because C23 (unlike earlier C standards) allows 
intmax_t to be narrower than int128_t (assuming the latter type exists, 
which it really should with GCC).

I'll propose further patches along those lines.