wasmtime-runtime 12.0.2

Runtime library support for Wasmtime
Documentation 
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#[rustfmt::skip]
macro_rules! wasm_to_libcall_trampoline {
    ($libcall:ident ; $libcall_impl:ident) => {
        wasmtime_asm_macros::asm_func!(
            wasmtime_versioned_export_macros::versioned_stringify_ident!($libcall),
            "
                .cfi_startproc
                bti c

                // Load the pointer to `VMRuntimeLimits` in `x9`.
                ldur x9, [x0, #8]

                // Store the last Wasm FP into the `last_wasm_exit_fp` in the limits.
                stur fp, [x9, #24]

                // Store the last Wasm PC into the `last_wasm_exit_pc` in the limits.
                stur lr, [x9, #32]

                // Tail call to the actual implementation of this libcall.
                b {}

                .cfi_endproc
            ",
            sym $libcall_impl
        );
    };
}

#[cfg(test)]
mod wasm_to_libcall_trampoline_offsets_tests {
    use wasmtime_environ::{Module, PtrSize, VMOffsets};

    #[test]
    fn test() {
        let module = Module::new();
        let offsets = VMOffsets::new(std::mem::size_of::<*mut u8>() as u8, &module);

        assert_eq!(8, offsets.vmctx_runtime_limits());
        assert_eq!(24, offsets.ptr.vmruntime_limits_last_wasm_exit_fp());
        assert_eq!(32, offsets.ptr.vmruntime_limits_last_wasm_exit_pc());
    }
}