Re: Make copyObject work in C++

On 04.02.26 16:54, Bryan Green wrote:
> On 1/25/2026 6:42 AM, Jelte Fennema-Nio wrote:
>> On Tue Jan 20, 2026 at 5:28 PM CET, Peter Eisentraut wrote:
>>> I have split your first patch further.  For a start, I left out the
>>> PG_MODULE_MAGIC*-related changes and disabled the module under MSVC.
>>> This has been committed.  I plan to let the buildfarm run with it for
>>> a day or two and then add in the basic MSVC support.
>>
>> To hopefully make your life a bit easier. Here's a rebased version that
>> enables the MSVC support again, with an updated commit message.
>>
> This causes the build to break on VS 2022. Versions prior do not have
> support for __typeof_unqual__. This would have led to
> HAVE_TYPEOF_UNQUAL being not defined on the buildfarm causing the
> fallback to copyObjectImpl() for VS 2019.
>
> When you build on VS 2022 you will get an error:
> ../src/backend/commands/event_trigger.c(1901): error C2100: you cannot
> dereference an operand of type 'void'
>
> VS 2022 (MSVC) does not handle the void * dereference the way gcc/clang
> does (thanks to GNU extensions, I believe). It exposes
> __typeof_unqual__ even it C11, but enforces strict C semantics on the
> void * dereference. To work on this platform the call
> copyObject(lfirst(cell)) would need to have a cast to the correct
> concrete type: copyObject((Node *)lfirst(cell)).
>
> I was about to update to VS 2026, but now I think I should have an
> instance of VS from 2019, 2022, and 2026.

I have reverted this patch for now to research it further.