export_native_api.md: Relax the "ground rule" #1577
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Nothing wrong with passing structures and function pointers as far as the native code is aware of and careful about the ABI used in the wasm module.
| A few recommendations: | ||
| - Never pass any structure/class object pointer to native (do data serialization instead) | ||
| - Do the pointer address conversion in the native API if "$\*" is not used for the pointer in the function signature |
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I think the pointer address conversion is still a hard rule, not a recommendation?
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I agree @loganek . The main question here is regarding the sentence:
Never pass a function pointer to the native
Can we pass a function pointer (using integer in the signature) to native and from the native side call this function with wasm_runtime_call_indirect? Is this the only way to pass a callback?
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it depends on the api.
eg. a "user data" pointer for a callback, which is just passed back to the calling wasm module, needs no interpretation in native side.
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Hmm, I think this is more like a different case and I'm not convinced this should be bundled together in here. Or at least we should say something like:
Ground rule: Do the pointer address conversion in the native API if "$*" is not used for the pointer in the function signature, unless the pointer is not used in native code.
Nothing wrong with passing structures and function pointers as far as the native code is aware of and careful about the ABI used in the wasm module.
Nothing wrong with passing structures and function pointers as far as the native code is aware of and careful about the ABI used in the wasm module.