Enable the 'custom vtable' feature on ARM64e#26475
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EdSchouten wants to merge 1 commit intoprotocolbuffers:mainfrom
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Enable the 'custom vtable' feature on ARM64e#26475EdSchouten wants to merge 1 commit intoprotocolbuffers:mainfrom
EdSchouten wants to merge 1 commit intoprotocolbuffers:mainfrom
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ARM64e is ARM64 plus pointer authentication: https://clang.llvm.org/docs/PointerAuthentication.html With pointer authentication enabled, there are certain constructs that are no longer permitted/supported. For example, it is no longer possible to memcpy() C++ objects that use vtables. The reason being that each object's vtable pointer is signed using the object's address. Unfortunately, the Protobuf library does that a lot. This leads to various crashes. One way to work around this is to build the Protobuf library with the 'custom vtable' feature enabled. This causes message types to follow the standard layout (i.e., not having a C++ class vtable).
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ARM64e is ARM64 plus pointer authentication:
https://clang.llvm.org/docs/PointerAuthentication.html
With pointer authentication enabled, there are certain constructs that are no longer permitted/supported. For example, it is no longer possible to memcpy() C++ objects that use vtables. The reason being that each object's vtable pointer is signed using the object's address. Unfortunately, the Protobuf library does that a lot. This leads to various crashes.
One way to work around this is to build the Protobuf library with the 'custom vtable' feature enabled. This causes message types to follow the standard layout (i.e., not having a C++ class vtable).