C++: Adjust implicit '__cxa_bad_typeid' prototype to reality

[Thomas Schwinge]

Hi!

On 2025-03-24T13:38:56-0400, Jason Merrill <jason@redhat.com> wrote:
> On 3/24/25 7:02 AM, Thomas Schwinge wrote:
>> On 2025-03-21T15:46:01+0100, I wrote:
>>> On 2025-03-19T14:25:49+0000, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
>>>> On Wed, 19 Mar 2025 at 14:21, Marek Polacek <polacek@redhat.com> wrote:
>>>>> On Wed, Mar 19, 2025 at 12:38:31PM +0100, Thomas Schwinge wrote:
>>>>>> --- a/gcc/cp/rtti.cc
>>>>>> +++ b/gcc/cp/rtti.cc
>>>>>> @@ -198,7 +198,7 @@ throw_bad_cast (void)
>>>>>>         fn = get_global_binding (name);
>>>>>>         if (!fn)
>>>>>>        fn = push_throw_library_fn
>>>>>> -       (name, build_function_type_list (ptr_type_node, NULL_TREE));
>>>>>> +       (name, build_function_type_list (void_type_node, NULL_TREE));
>>>>>>       }
>>>>>>
>>>>>>     return build_cxx_call (fn, 0, NULL, tf_warning_or_error);
>>>>>
>>>>> LGTM, matches what I see in abi-eh.html from the itanium-cxx-abi.
>> 
>>> [...] I've now pushed to trunk branch:
>>> commit 618c42d23726be6e2086d452d6718abe5e0daca8
>>> "C++: Adjust implicit '__cxa_bad_cast' prototype to reality", [...]
>> 
>> So, a similar problem exists for '__cxa_bad_typeid'.  See the attached
>> "[WIP] C++: Adjust implicit '__cxa_bad_typeid' prototype to reality" for
>> what seemed to be the corresponding patch for that one.  However, that
>> isn't sufficient; we run into internal errors like:
>> 
>>      [...]/g++.dg/rtti/typeid1.C: In function 'int main()':
>>      [...]/g++.dg/rtti/typeid1.C:9:12: error: lvalue required as unary '&' operand
>> 
>> I got lost in the C++ front end code trying to understand how to resolve
>> this mismatch.  Anyone able to advise, please?
>
> This addition seems to resolve it: [...]

Yes, thanks!  OK to push the attached
"C++: Adjust implicit '__cxa_bad_typeid' prototype to reality"?


Grüße
 Thomas


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