Embed a bindgen function

In , we will demonstrate how to call a few simple WebAssembly functions from a Go app. The functions are written in Rust, and require complex call parameters and return values. The #[wasm_bindgen] macro is needed for the compiler tools to auto-generate the correct code to pass call parameters from Go to WebAssembly.

The WebAssembly spec only supports a few simple data types out of the box. It types such as string and array. In order to pass rich types in Go to WebAssembly, the compiler needs to convert them to simple integers. For example, it converts a string into an integer memory address and an integer length. The wasm_bindgen tool, embedded in rustwasmc, does this conversion automatically.

At this time, we require Rust compiler version 1.50 or less in order for WebAssembly functions to work with WasmEdge’s Go API. We will compiler version once the Interface Types spec is finalized and supported.

The Go source code to run the WebAssembly function in WasmEdge is as follows. The ExecuteBindgen() function calls the WebAssembly function and passes the call parameters using the #[wasm_bindgen] convention.

go get github.com/second-state/WasmEdge-go/wasmedge@v0.10.0 go build

Run the Go application and it will run the WebAssembly functions embedded in the WasmEdge runtime.

$ ./bindgen_funcs rust_bindgen_funcs/pkg/rust_bindgen_funcs_lib_bg.wasm Run bindgen -- say: hello bindgen funcs test Run bindgen -- obfusticate: N dhvpx oebja sbk whzcf bire gur ynml qbt Run bindgen -- lowest_common_multiple: 246 Run bindgen -- sha3_digest: [87 27 231 209 189 105 251 49 159 10 211 250 15 159 154 181 43 218 26 141 56 199 25 45 60 10 20 163 54 211 195 203] Run bindgen -- keccak_digest: [126 194 241 200 151 116 227 33 216 99 159 22 107 3 177 169 216 191 114 156 174 193 32 159 246 228 245 133 52 75 55 27]