[Bug c++/98052] New: Allocation with new and deallocation with std::allocator should result in an error

[Bug c++/98052] New: Allocation with new and deallocation with std::allocator should result in an error

[src at andyf dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98052

            Bug ID: 98052
           Summary: Allocation with new and deallocation with
                    std::allocator should result in an error
           Product: gcc
           Version: 10.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: src at andyf dot de
  Target Milestone: ---

Hello,

the following code compiles without an error (https://godbolt.org/z/oPG8Ea) in
GCC:


#include <memory>

constexpr auto fun()
{
    int* i = new int{4};

    std::allocator<int> a{};
    a.deallocate(i, 1);

    return 0;
}

int main()
{
    constexpr auto f = fun();
}


In the constexpr function fun, an int is allocated with new and free'd with
std::allocator's deallocate. According to N4868 [allocator.members] p6, a
precondition for deallocate is that the memory was previously allocated with
allocate. Clang does reject the code with:

note: 'std::allocator<...>::deallocate' used to delete pointer to object
allocated with 'new'

The behavior of Clang seems to be consistent with the wording. GCC incorrectly
allows this code to compile.


Best,

   Andreas

[Bug c++/98052] Allocation with new and deallocation with std::allocator should result in an error

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98052

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |accepts-invalid
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2020-11-29

[Bug c++/98052] Allocation with new and deallocation with std::allocator should result in an error

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98052

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |DUPLICATE
             Status|NEW                         |RESOLVED

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Dup of bug 95797.

*** This bug has been marked as a duplicate of bug 95797 ***