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From: "joseph at codesourcery dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/95722] libatomic crashes on __atomic_load of const object
Date: Thu, 18 Jun 2020 16:16:23 +0000	[thread overview]
Message-ID: <bug-95722-4-be3vY6USWm@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-95722-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95722

--- Comment #3 from joseph at codesourcery dot com <joseph at codesourcery dot com> ---
See bugs 70490 and 84563 regarding atomic_load of const.

The atomic_load generic function takes a pointer-to-const-atomic argument 
just like any other library function that takes an argument it does not 
modify.  It's certainly valid to do an atomic load through such a pointer 
in a case where the original object was not defined as const but a pointer 
to const was passed to the function doing the load.

The question is whether it is or should be valid in the case where the 
object was defined as const.  If it is, that would constrain code 
sequences used in any case where the compiler cannot see that the object 
definitely isn't in read-only memory, including for other operations that 
might only be valid for writable memory but need to interact correctly 
with atomic_load.

  parent reply	other threads:[~2020-06-18 16:16 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-17 14:55 [Bug other/95722] New: " luis at luismarques dot eu
2020-06-17 19:10 ` [Bug target/95722] " foom at fuhm dot net
2020-06-18  8:30 ` [Bug c/95722] " rguenth at gcc dot gnu.org
2020-06-18 16:16 ` joseph at codesourcery dot com [this message]
2021-08-28 20:55 ` [Bug target/95722] " pinskia at gcc dot gnu.org

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