Re: [PATCH] libgcc: Avoid warnings on __gcc_nested_func_ptr_created [PR113402]

[Iain Sandoe <iain@sandoe.co.uk>]

> On 1 Feb 2024, at 08:51, Richard Biener <richard.guenther@gmail.com> wrote:
> 
> On Thu, Feb 1, 2024 at 9:23 AM Jakub Jelinek <jakub@redhat.com> wrote:
>> 
>> On Wed, Jan 31, 2024 at 01:04:20PM +0100, Jakub Jelinek wrote:
>>> On Sun, Jan 28, 2024 at 11:02:33AM +0000, Iain Sandoe wrote:
>>>>    * config/aarch64/heap-trampoline.c: Rename
>>>>    __builtin_nested_func_ptr_created to __gcc_nested_func_ptr_created and
>>>>    __builtin_nested_func_ptr_deleted to __gcc_nested_func_ptr_deleted.
>>>>    * config/i386/heap-trampoline.c: Likewise.
>>>>    * libgcc2.h: Likewise.
>>> 
>>> I'm seeing hundreds of
>>> In file included from ../../../libgcc/libgcc2.c:56:
>>> ../../../libgcc/libgcc2.h:32:13: warning: conflicting types for built-in function ‘__gcc_nested_func_ptr_created’; expected ‘void(void *, void *, void *)’ [-Wbuiltin-declaration-mismatch]
>>>   32 | extern void __gcc_nested_func_ptr_created (void *, void *, void **);
>>>      |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>> warnings.
>>> 
>>> Either we need to add like in r14-6218
>>> #pragma GCC diagnostic ignored "-Wbuiltin-declaration-mismatch"
>>> (but in that case because of the libgcc2.h prototype (why is it there?)
>>> it would need to be also with #pragma GCC diagnostic push/pop around),
>>> or we could go with just following how the builtins are prototyped on the
>>> compiler side and only cast to void ** when dereferencing (which is in
>>> a single spot in each TU).
>> 
>> Bootstrapped/regtested on x86_64-linux and i686-linux successfully.
> 
> Looks obvious to me.

Thanks, also tested on x86_64 darwin; I guess having typed pointers on the builtins
would be a pretty tricky change.

Iain

> 
> Richard.
> 
>>> 2024-01-31  Jakub Jelinek  <jakub@redhat.com>
>>> 
>>>      * libgcc2.h (__gcc_nested_func_ptr_created): Change type of last
>>>      argument from void ** to void *.
>>>      * config/i386/heap-trampoline.c (__gcc_nested_func_ptr_created):
>>>      Change type of dst from void ** to void * and cast dst to void **
>>>      before dereferencing it.
>>>      * config/aarch64/heap-trampoline.c (__gcc_nested_func_ptr_created):
>>>      Likewise.
>> 
>>        Jakub