[cxx-interop] Fix over-releasing reference members of trival C++ types #84321
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Xazax-hun
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j-hui
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Sep 16, 2025
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We're not modeling these types as POD in any way in the Swift compiler, right? You're saying "POD" because C++ says they're POD, but we're modeling them as non-trivial types? |
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Indeed, I updated the PR title and the comments of the code to not confuse POD types in C++ with trivial types in Swift. |
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Large trivial types were copied via memcpy instead of doing a field-wise copy. This is incorrect for types with reference fields where we also need to bump the corresponding refcounts. rdar://160315343
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@swift-ci please test |
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… types Explanation: Large trivial types were copied via memcpy instead of doing a field-wise copy. This is incorrect for types with reference fields where we also need to bump the corresponding refcounts. This PR makes sure that trival C++ types with reference members are not trivial in Swift. Issues: rdar://160315343 Original PRs: swiftlang#84321 Risk: There is a low chance of breaking source compatibility as some types that used to be BitwiseCopyable are no longer considered as such. However, code relying on that probably has latent memory safety bugs. Testing: Added a compiler test. Reviewers: @egorzhdan, @j-hui
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… types Explanation: Large trivial types were copied via memcpy instead of doing a field-wise copy. This is incorrect for types with reference fields where we also need to bump the corresponding refcounts. This PR makes sure that trival C++ types with reference members are not trivial in Swift. Issues: rdar://160315343 Original PRs: swiftlang#84321 Risk: There is a low chance of breaking source compatibility as some types that used to be BitwiseCopyable are no longer considered as such. However, code relying on that probably has latent memory safety bugs. Testing: Added a compiler test. Reviewers: @egorzhdan, @j-hui
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Large trivial types were copied via memcpy instead of doing a field-wise copy. This is incorrect for types with reference fields where we also need to bump the corresponding refcounts.
rdar://160315343