[PATCH] D128619: [Clang] Implement P0848 (Conditionally Trivial Special Member Functions)

[Roy Jacobson via Phabricator via cfe-commits]

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The implementation is more or less complete, but I still need to add an AST test for canPassInRegisters.


royjacobson added a comment.

Implementation ready for CR.



================
Comment at: clang/www/cxx_status.html:930
         <td><a href="https://wg21.link/p0848r3">P0848R3</a></td>
-        <td rowspan="1" class="none" align="center">No</td>
+        <td rowspan="1" class="none" align="center">Clang 15</td>
       </tr>
----------------
Should be `class="unreleased"`, I believe


================
Comment at: clang/www/cxx_status.html:930
         <td><a href="https://wg21.link/p0848r3">P0848R3</a></td>
-        <td rowspan="1" class="none" align="center">No</td>
+        <td rowspan="1" class="none" align="center">Clang 15</td>
       </tr>
----------------
h-vetinari wrote:
> Should be `class="unreleased"`, I believe
Thanks, nice catch!


This patch implements P0848 in Clang.

During the instantiation of a C++ class, in `Sema::ActOnFields`, we evaluate constraints for all the SMFs and compare the constraints to compute the eligibility. We defer the computation of the type's [copy-]trivial bits from addedMember to the eligibility computation, like we did for destructors in D126194 <https://reviews.llvm.org/D126194>. `canPassInRegisters` is modified as well to better respect the ineligibility of functions.

Note: Because of the non-implementation of DR1734 and DR1496, I treat deleted member functions as 'eligible' for the purpose of [copy-]triviallity. This is unfortunate, but I couldn't think of a way to make this make sense otherwise.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D128619

Files:
  clang/docs/ReleaseNotes.rst
  clang/lib/AST/DeclCXX.cpp
  clang/lib/Frontend/InitPreprocessor.cpp
  clang/lib/Sema/SemaDecl.cpp
  clang/lib/Sema/SemaDeclCXX.cpp
  clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
  clang/test/AST/conditionally-trivial-smfs.cpp
  clang/test/Lexer/cxx-features.cpp
  clang/test/SemaCXX/constrained-special-member-functions.cpp
  clang/www/cxx_status.html

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