Re: [PATCH v3] c++: Adjust constexpr covariant call results [PR126324]

On 8/14/26 6:08 PM, Odysseas Georgoudis wrote:
>    Hi Jason,
> 
>    Thanks. Attached is v3 with the requested changes: the commit message is
>    wrapped at 76 columns, the test is renamed, and the type check now uses
>    INDIRECT_TYPE_P with the additional parentheses.
> 
>    I kept the type guard because this adjustment is specifically for 
> covariant
>    pointer or reference returns.  I also rebased onto current master.
> 
>    Tested on x86_64-pc-linux-gnu with no unexpected constexpr or consteval
>    test failures.

Pushed, thanks!
>    Thanks,
>    Odysseas
> ------------------------------------------------------------------------
> *From:* Jason Merrill <[email protected]>
> *Sent:* 14 August 2026 18:57
> *To:* Odysseas Georgoudis <[email protected]>; [email protected] 
> <[email protected]>
> *Subject:* Re: [PATCH v2] c++: Adjust constexpr covariant call results 
> [PR126324]
> On 7/26/26 5:15 PM, Odysseas Georgoudis wrote:
>> Hi Jason,
>> 
>> Thanks for catching the non-zero-offset case.
>> In v2, the result-thunk path now preserves null pointers,
>> evaluates the call only once, and adjusts the result to
>> the thunk’s static return type.
>> 
>> The test covers both zero- and non-zero-offset bases.
> Looks good, just a few tweaks.
> 
>> pointers, evaluate the call only once, and give the result the thunk's static
>>        * constexpr.cc (cxx_eval_thunk_call): Preserve null pointer results and
> These lines are too long; the commit message should wrap at column 76 to
> accommodate 'git log' adding 4 spaces on the left.
> 
>>        * g++.dg/cpp2a/pr126324.C: New test.
> 
> Let's add "constexpr-virtual" to the filename, i.e.
> constexpr-virtual-pr126324.C
> 
>> +      && scalarish_type_p (TREE_TYPE (t))
> 
> Let's use INDIRECT_TYPE_P since a covariant return type will be pointer
> or reference.  Or drop this line entirely; is it needed?
> 
>> +      && !same_type_ignoring_top_level_qualifiers_p
>> +        (TREE_TYPE (result), TREE_TYPE (t)))
> 
> This needs another set of parens starting either before or after the !
> to prevent emacs from moving the args to line up with the &&.
> 
> Jason
>