feat(c-api) Implement the traps argument of wasm_instance_new
#1761
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When running `Instance::new`, it can error with an `InstantiationError`. There is 2 scenarii: 1. Either it's a `InstantiationError::Link`. In this case, the `wasm_instance_new` function must return `NULL` and register the error in the Wasmer error registry. 2. Either it's a `InstantiationError::Start`. In this case, the `wasm_instance_new` function must return `NULL` and the error must be converted into a `wasm_trap_t`, which is stored in the `wasm_trap_t**` array. This array is initialized by `wasm_instance_new` itself.
Hywan
added
🎉 enhancement
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I'm not sure why |
| @@ -17,8 +17,7 @@ pub unsafe extern "C" fn wasm_instance_new( | |||
| _store: &wasm_store_t, | |||
| module: &wasm_module_t, | |||
| imports: &wasm_extern_vec_t, | |||
| // own | |||
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Might be useful to put this comment back if it's correct, otherwise it's not clear what the ownership is of *mut *mut, own means we're responsible for freeing it I believe
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We can't own it. We can't free it. The start.c example explicitely drops the trap value:
wasmer/lib/c-api/tests/wasm_c_api/wasm-c-api/example/start.c
Lines 58 to 60 in 86f3438
and later:
I believe that the value is owned by the caller, not by the callee.
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Huh, own wasm_trap_t** is weird in the context of using arguments as outputs.
It seems like there's no need for the Vec at all then, this just seems to be a double pointer for the sake of setting a trap*
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So wasm_trap_t** must not be interpreted as an array of wasm_trap_t*, hmm. Let's fix that then.
Ensure that the size of the vector of the instance's traps equals its capacity by shrinking it.
…an array. The `wasm_trap_t**` argument of `wasm_instance_new` represents an output pointer to a `wasm_trap_t*`, not an array of `wasm_trap_t*`. This patch updates the code accordingly.
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bors r+ |
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Build succeeded: |
Description
When running
Instance::new, it can error with anInstantiationError. There is 2 scenarii:Either it's a
InstantiationError::Link. In this case, thewasm_instance_newfunction must returnNULLand register theerror in the Wasmer error registry.
Either it's a
InstantiationError::Start. In this case, thewasm_instance_newfunction must returnNULLand the error must beconverted into a
wasm_trap_t*, which is stored in thewasm_trap_t**.Review
Fixes #1744.