[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <b8952252-7b81-1b3c-9b2f-b6d170bc2c25@mirbsd.de>
Date: Fri, 7 Mar 2025 20:09:28 +0100 (CET)
From: Thorsten Glaser <tg@...bsd.de>
To: musl@...ts.openwall.com
Subject: Re: f128 aliases for long double math symbols
On Fri, 7 Mar 2025, Rich Felker wrote:
>The type issue is completely separate. It's a matter of the library
>implementation invoking UB with respect to the compiler implementation
1. The library implementation does not need to use C.
2. The C standard explicitly allows the implementation itself
to handwave numerous things that would otherwise be UB in
application code, e.g. pre-C23 there was no way to write
strchr(3) in conforming C.
>This will break for example with LTO or certain kinds of call integrity
>hardening that check signatures.
That’s a deficiency in these tools, but one that doesn’t prevent
environments where these tools are a nōn-issue from it.
>The issue at hand is one of the implementation not conforming to
>requirements that applications are permitted to rely upon.
That’s explicitly allowed by the standard.
>> i dont think the standard explicitly requires unequal library
>> functions.
>
>I don't see how you read that. The standard specifies two functions,
>and specifies that different functions compare not-equal. It does not
>rigorously define the word "different" but that's par for WG14.
It does not mandate that memcpy be different from memmove either
(in fact Stephen found the DR stating that they may indeed be equal).
bye,
//mirabilos
--
I believe no one can invent an algorithm. One just happens to hit upon it
when God enlightens him. Or only God invents algorithms, we merely copy them.
If you don't believe in God, just consider God as Nature if you won't deny
existence. -- Coywolf Qi Hunt
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
