replacing u32 -> string in adder tutorial example

[dmk978]

Let's try mentioned example for use with string, that's absolute straightforward. Component compiles well, but issuing

wasm-tools component wit target/wasm32-wasip1/release/adder.wasm

command produce really big file filled with a lot of imports and references to standard WASI worlds:

package root:component;

world root {
  import wasi:cli/[email protected];
  import wasi:cli/[email protected];
  import wasi:io/[email protected];
  import wasi:io/[email protected];
  import wasi:cli/[email protected];
  import wasi:cli/[email protected];
  import wasi:cli/[email protected];
  import wasi:clocks/[email protected];
  import wasi:filesystem/[email protected];
  import wasi:filesystem/[email protected];

  export docs:adder/[email protected];
}

and that continues for several screens. Why?

[vados-cosmonic]

Hey @dmk978 these dependencies are included because of Rust unwind/panic/stack unwind capability. If you'd like to avoid them, you can do one of at least two things:

• use wasm32-unknown-unknown as your target (i.e. cargo component build --target wasm32-unknown-unknown)
• Use nightly rust and a custom build command to remove the panic machinery

IIRC wasm32-wasip2 (which is available now) will also have this same issue, because by default the panic/debug/stack unwinding logic is included.

@kate-goldenring I think this should be closable!

[vados-cosmonic]

Ah, see also this discussion on Zulip which has come up a bit: #wit-bindgen > How to identify source of WASI imports? @ 💬

[vados-cosmonic]

Hey @kate-goldenring can we close this in favor of #120 ? My thought here is that this individual issue is solved, but we should definitely include it in the FAQ (it's quite Rust specific, but the question of "where did all these extra imports come from" is valid across languages).