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* [Bug c++/104141] New: Access to private member function from requires-clause accepted
@ 2022-01-20 7:14 fchelnokov at gmail dot com
2022-01-21 3:56 ` [Bug c++/104141] nested requires statement causes access to private member function pinskia at gcc dot gnu.org
` (5 more replies)
0 siblings, 6 replies; 7+ messages in thread
From: fchelnokov at gmail dot com @ 2022-01-20 7:14 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104141
Bug ID: 104141
Summary: Access to private member function from requires-clause
accepted
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: fchelnokov at gmail dot com
Target Milestone: ---
This is invalid code:
```
class A{
static void f();
};
static_assert( requires{ !requires{ A::f(); }; } );
```
and rejected by Clang and MSVC due to access to a private member function. But
GCC accepts it. Demo: https://gcc.godbolt.org/z/76jhYav4v
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/104141] nested requires statement causes access to private member function
2022-01-20 7:14 [Bug c++/104141] New: Access to private member function from requires-clause accepted fchelnokov at gmail dot com
@ 2022-01-21 3:56 ` pinskia at gcc dot gnu.org
2022-01-21 3:58 ` pinskia at gcc dot gnu.org
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu.org @ 2022-01-21 3:56 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104141
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Summary|Access to private member |nested requires statement
|function from |causes access to private
|requires-clause accepted |member function
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I am not 100% up to speed on requires statment here but I would assume the
outer requires would cause the inner requires to be slient on access
violations.
E.g the following is accepted without error even:
class A{
static void f();
};
template <class T> concept t = requires{ T::f(); };
static_assert( !t<A> );
------ CUT ----
Likewise of this one where we don't have a depdent requires even (clang rejects
it but GCC/MSVC accept it):
class A{
static void f();
};
template <class T> constexpr bool t = requires{ A::f(); };
static_assert( !t<A> );
------ CUT ----
But GCC fails with this one but if the above is valid I don't see why the below
is not either:
class A{
static void f();
};
static_assert( !requires{ A::f(); } );
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/104141] nested requires statement causes access to private member function
2022-01-20 7:14 [Bug c++/104141] New: Access to private member function from requires-clause accepted fchelnokov at gmail dot com
2022-01-21 3:56 ` [Bug c++/104141] nested requires statement causes access to private member function pinskia at gcc dot gnu.org
@ 2022-01-21 3:58 ` pinskia at gcc dot gnu.org
2022-01-21 4:03 ` pinskia at gcc dot gnu.org
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu.org @ 2022-01-21 3:58 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104141
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Note clang fails the static_assert with this one but that does not make sense
at all:
class A{
static void f();
};
template <class T> concept t = requires{ A::f(); };
static_assert( !t<A> );
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/104141] nested requires statement causes access to private member function
2022-01-20 7:14 [Bug c++/104141] New: Access to private member function from requires-clause accepted fchelnokov at gmail dot com
2022-01-21 3:56 ` [Bug c++/104141] nested requires statement causes access to private member function pinskia at gcc dot gnu.org
2022-01-21 3:58 ` pinskia at gcc dot gnu.org
@ 2022-01-21 4:03 ` pinskia at gcc dot gnu.org
2022-01-21 8:30 ` fchelnokov at gmail dot com
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu.org @ 2022-01-21 4:03 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104141
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Looks like clang does not always do access checking for static functions calls
inside requires. I know GCC has a bug there for dealing with caching in the
wrong context (I don't have the bug #).
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/104141] nested requires statement causes access to private member function
2022-01-20 7:14 [Bug c++/104141] New: Access to private member function from requires-clause accepted fchelnokov at gmail dot com
` (2 preceding siblings ...)
2022-01-21 4:03 ` pinskia at gcc dot gnu.org
@ 2022-01-21 8:30 ` fchelnokov at gmail dot com
2022-01-21 8:39 ` pinskia at gcc dot gnu.org
2022-01-21 8:42 ` fchelnokov at gmail dot com
5 siblings, 0 replies; 7+ messages in thread
From: fchelnokov at gmail dot com @ 2022-01-21 8:30 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104141
--- Comment #4 from Fedor Chelnokov <fchelnokov at gmail dot com> ---
In
```
template <class T> concept t = requires{ A::f(); };
```
A::f() does not depend on template parameter, so the rules here are somewhat
different than in T::f(). A possible answer:
https://stackoverflow.com/a/70783451/7325599
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/104141] nested requires statement causes access to private member function
2022-01-20 7:14 [Bug c++/104141] New: Access to private member function from requires-clause accepted fchelnokov at gmail dot com
` (3 preceding siblings ...)
2022-01-21 8:30 ` fchelnokov at gmail dot com
@ 2022-01-21 8:39 ` pinskia at gcc dot gnu.org
2022-01-21 8:42 ` fchelnokov at gmail dot com
5 siblings, 0 replies; 7+ messages in thread
From: pinskia at gcc dot gnu.org @ 2022-01-21 8:39 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104141
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Fedor Chelnokov from comment #4)
> A::f() does not depend on template parameter, so the rules here are somewhat
> different than in T::f(). A possible answer:
> https://stackoverflow.com/a/70783451/7325599
But clang is not rejecting it the following:
class A{
static void f();
};
template <class T> concept t = requires{ A::f(); };
static_assert( !t<A> );
By saying A::f() is private even, it literally sets the concept to false and
nothing else which is really really shocking.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/104141] nested requires statement causes access to private member function
2022-01-20 7:14 [Bug c++/104141] New: Access to private member function from requires-clause accepted fchelnokov at gmail dot com
` (4 preceding siblings ...)
2022-01-21 8:39 ` pinskia at gcc dot gnu.org
@ 2022-01-21 8:42 ` fchelnokov at gmail dot com
5 siblings, 0 replies; 7+ messages in thread
From: fchelnokov at gmail dot com @ 2022-01-21 8:42 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104141
--- Comment #6 from Fedor Chelnokov <fchelnokov at gmail dot com> ---
I agree that Clang behavior here might be wrong. Submitted
https://github.com/llvm/llvm-project/issues/53334
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2022-01-21 8:42 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
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2022-01-20 7:14 [Bug c++/104141] New: Access to private member function from requires-clause accepted fchelnokov at gmail dot com
2022-01-21 3:56 ` [Bug c++/104141] nested requires statement causes access to private member function pinskia at gcc dot gnu.org
2022-01-21 3:58 ` pinskia at gcc dot gnu.org
2022-01-21 4:03 ` pinskia at gcc dot gnu.org
2022-01-21 8:30 ` fchelnokov at gmail dot com
2022-01-21 8:39 ` pinskia at gcc dot gnu.org
2022-01-21 8:42 ` fchelnokov at gmail dot com
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