5 Commits

Author SHA1 Message Date
Volodymyr Sapsai
d1e8df85e6
[clang] Fix a typo "mdoule" in comments. NFC. 2023-07-06 17:19:26 -07:00
Chuanqi Xu
2d8044ee8b Recommit [ABI] [C++20] [Modules] Don't generate vtable if the class is defined in other module unit
Close https://github.com/llvm/llvm-project/issues/61940.

The root cause is that clang will generate vtable as strong symbol now
even if the corresponding class is defined in other module units. After
I check the wording in Itanium ABI, I find this is not inconsistent.
Itanium ABI 5.2.3
(https://itanium-cxx-abi.github.io/cxx-abi/abi.html#vague-vtable) says:

> The virtual table for a class is emitted in the same object containing
> the definition of its key function, i.e. the first non-pure virtual
> function that is not inline at the point of class definition.

So the current behavior is incorrect. This patch tries to address this.
Also I think we need to do a similar change for MSVC ABI. But I don't
find the formal wording. So I don't address this in this patch.

Reviewed By: rjmccall, iains, dblaikie

Differential Revision: https://reviews.llvm.org/D150023
2023-06-19 10:41:12 +08:00
Nico Weber
dbdd6372b7 Revert "[ABI] [C++20] [Modules] Don't generate vtable if the class is defined in other module unit"
Breaks check-clang on win and mac, see comments on https://reviews.llvm.org/D150023

This reverts commit d8a36b00d198fdc2ea866ea5da449628db07070f.

Also revert follow-up "[NFC] skip the test modules-vtable.cppm on windows"
This reverts commit baf0b12ca6c624b2a59aa6f2fd0310c72d35ac56.
2023-06-14 16:17:42 -07:00
Chuanqi Xu
baf0b12ca6 [NFC] skip the test modules-vtable.cppm on windows
The new added test has problems on windows since the patch is about ABI
and MSVC ABI is not covered. Skip the test on windows to make the CI
green.
2023-06-14 15:05:31 +08:00
Chuanqi Xu
d8a36b00d1 [ABI] [C++20] [Modules] Don't generate vtable if the class is defined in other module unit
Close https://github.com/llvm/llvm-project/issues/61940.

The root cause is that clang will generate vtable as strong symbol now
even if the corresponding class is defined in other module units. After
I check the wording in Itanium ABI, I find this is not inconsistent.
Itanium ABI 5.2.3
(https://itanium-cxx-abi.github.io/cxx-abi/abi.html#vague-vtable) says:

> The virtual table for a class is emitted in the same object containing
> the definition of its key function, i.e. the first non-pure virtual
> function that is not inline at the point of class definition.

So the current behavior is incorrect. This patch tries to address this.
Also I think we need to do a similar change for MSVC ABI. But I don't
find the formal wording. So I don't address this in this patch.

Reviewed By: rjmccall, iains, dblaikie

Differential Revision: https://reviews.llvm.org/D150023
2023-06-14 12:45:34 +08:00