[PATCH] D112921: [clang] Enable sized deallocation by default in C++14 onwards

[Wang Pengcheng via Phabricator via cfe-commits]

wangpc added a comment.

In D112921#4536088 <https://reviews.llvm.org/D112921#4536088>, @Mordante wrote:

> In D112921#4535716 <https://reviews.llvm.org/D112921#4535716>, @wangpc wrote:
>
>> In D112921#4532378 <https://reviews.llvm.org/D112921#4532378>, @Mordante wrote:
>>
>>> In D112921#4530916 <https://reviews.llvm.org/D112921#4530916>, @wangpc wrote:
>>>
>>>> In D112921#4529182 <https://reviews.llvm.org/D112921#4529182>, @Mordante wrote:
>>>>
>>>>> I noticed some of the CI jobs are still failing with the patch, I didn't look into them.
>>>>
>>>> I don't think they are related to this patch, so I rebased again. If still failed, I will try to fix them later.
>>>
>>> I see changes in the libc++ ABI list output
>>>
>>>   Symbol added: _ZdlPvmSt11align_val_t
>>>       {'name': '_ZdlPvmSt11align_val_t', 'type': 'FUNC', 'is_defined': False}
>>>   
>>>   Symbol added: _ZdlPvm
>>>       {'name': '_ZdlPvm', 'type': 'FUNC', 'is_defined': False}
>>>   
>>>   SYMBOL REMOVED: _ZdlPvSt11align_val_t
>>>       {'is_defined': False, 'name': '_ZdlPvSt11align_val_t', 'type': 'FUNC'}
>>>   
>>>   Summary
>>>       Added:   2
>>>       Removed: 1
>>>       Changed: 0
>>>
>>> There seems to be small change in the symbol name. What does the `m` in the added symbol mean?
>>>
>>>   _ZdlPvmSt11align_val_t - added
>>>   _ZdlPvSt11align_val_t  - remove
>>>
>>> There is also a new symbol `_ZdlPvm` added.
>>
>> `m` means `unsigned long` in mangled name (5.1.5.2 Builtin types <https://itanium-cxx-abi.github.io/cxx-abi/abi.html#mangling-builtin>), which is the `size` of sized deallocation.
>>
>>   $ c++filt _ZdlPvmSt11align_val_t _ZdlPvm
>>   operator delete(void*, unsigned long, std::align_val_t)
>>   operator delete(void*, unsigned long)
>>
>> I am not familiar  with libcxx, can you please help me to fix these tests? I hope we can catch up with the release of LLVM 17.
>
> Looking at the ABI list we currently have
>
>   _ZdlPv -> operator delete(void*)                                   // this one is kept
>   _ZdlPvSt11align_val_t -> operator delete(void*, std::align_val_t)  // this one is removed
>
> You add the overloads
>
>   operator delete(void*, unsigned long, std::align_val_t)
>   operator delete(void*, unsigned long)
>
> Looking in the current WP http://eel.is/c++draft/replacement.functions#lib:new,operator the removed overload is still listed there.
>
> Do you know why `operator delete(void*)` and `operator delete(void*, unsigned long)` are both available?

I don't know the details about C++ spec, but I think they should be available for runtimes with/without sized deallocations.


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https://reviews.llvm.org/D112921