[wasm] Port BlocksRuntime for no dlfcn.h platforms #4869
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@swift-ci test |
Sources/BlocksRuntime/runtime.c
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| _Block_destructInstance = dlsym(RTLD_DEFAULT, "objc_destructInstance"); | ||
| # else | ||
| assert(0 && "No way to find objc_destructInstance on this platform"); |
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Can we just set _Block_destructInstance to NULL? IIRC, _Block_destructInstance(...) should do nothing if the pointer is NULL (this is how weak pointers work).
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_Block_destructInstance can be called without null guard https://github.com/apple/swift-corelibs-foundation/blob/dbca8c7ddcfd19f7f6f6e1b60fd3ee3f748e263c/Sources/BlocksRuntime/runtime.c#L530, so _Block_destructInstance_default might be safer here
BlocksRuntime uses dlsym to find objc_destructInstance, which is not available on all platforms. This change adds a check for dlfcn.h and only uses dlsym if it is available and otherwise crashes the program. The crash will not usually happen, as `_Block_use_RR` is only called from objc-auto, which is not available for such platforms.
kateinoigakukun
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Thanks @compnerd! Right, this change needs to be also applied to those copies eventually. |
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@swift-ci please test |
This seems to suggest the CF code is not being compiled with the correct flags on Darwin. |
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@parkera Yes, would you mind checking if the upstream has already fixed it or not? #4866 (comment) |
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@kateinoigakukun I don't think that |
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@compnerd Sorry, I don't understand why you mentioned assemblers here. Would you mind elaborating a little bit more? |
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Oh, I saw the old version of the comment where |
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Ah, that's my bad, sorry for confusion 😓 |
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@swift-ci test Windows platform |
kateinoigakukun
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BlocksRuntime uses dlsym to find objc_destructInstance, which is not available on all platforms. This change adds a check for dlfcn.h and only uses dlsym if it is available and otherwise crashes the program.
The crash will not usually happen, as
_Block_use_RRis only called from objc-auto, which is not available for such platforms.