🍒[cxx-interop][IRGen] Emit type metadata accessors correctly #74224
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This change makes sure we correctly emit IR for type metadata accessors for C++ reference types. This fixes linker errors when a type metadata of a C++ reference type is used in multiple object files that are later linked together, for instance, if a C++ reference type is conformed to different Swift protocols in different Swift source files: ``` duplicate symbol 'type metadata accessor for __C.SharedObject' in: main.o second.o ld: 1 duplicate symbols ``` rdar://129027705 (cherry picked from commit a5ce0dc)
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@swift-ci please test |
egorzhdan
changed the title
DougGregor
approved these changes
Jun 7, 2024
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Explanation: This makes sure we correctly emit IR for type metadata accessors for C++ reference types: This fixes linker errors when a type metadata of a C++ reference type is used in multiple object files that are later linked together, for instance, if a C++ reference type is conformed to different Swift protocols in different Swift source files:
Scope: Changes IRGen of type metadata for C++ reference types only.
Risk: Low, only affects C++ foreign reference types.
Testing: Added a compile test.
Issue: rdar://129027705
Reviewer: @rjmccall
Original PR: #74208