Use Go 1.21 WASI GOOS in examples

[leighmcculloch]

Go 1.21 will ship with a new GOARCH=wasm GOOS=wasip1 target. More details at https://tip.golang.org/doc/go1.21.

It should be possible to use that target instead of using tinygo.

[leighmcculloch]

I guess it is not so straightforward.

A simple Go app built to wasip1 requires the following imports:

wasi_snapshot_preview1.sched_yield
wasi_snapshot_preview1.proc_exit
wasi_snapshot_preview1.args_get
wasi_snapshot_preview1.args_sizes_get
wasi_snapshot_preview1.clock_time_get
wasi_snapshot_preview1.environ_get
wasi_snapshot_preview1.environ_sizes_get
wasi_snapshot_preview1.fd_write
wasi_snapshot_preview1.random_get
wasi_snapshot_preview1.poll_oneoff

Also, when I stub them with the following changes:

diff --git a/runtimes/web/src/runtime.ts b/runtimes/web/src/runtime.ts
index bf83d76..01c81d5 100644
--- a/runtimes/web/src/runtime.ts
+++ b/runtimes/web/src/runtime.ts
@@ -159,8 +159,21 @@ export class Runtime {
             tracef: this.tracef.bind(this),
         };
 
+        const wasi_snapshot_preview1 = {
+            sched_yield: () => {},
+            proc_exit: () => {},
+            args_get: () => {},
+            args_sizes_get: () => {},
+            clock_time_get: () => {},
+            environ_get: () => {},
+            environ_sizes_get: () => {},
+            fd_write: () => {},
+            random_get: () => {},
+            poll_oneoff: () => {},
+        };
+
         await this.bluescreenOnError(async () => {
-            const module = await WebAssembly.instantiate(wasmBuffer, { env });
+            const module = await WebAssembly.instantiate(wasmBuffer, { env, wasi_snapshot_preview1 });
             this.wasm = module.instance;
 
             // Call the WASI _start/_initialize function (different from WASM-4's start callback!)

It still doesn't run, and produces this error in the browser:

Unhandled Promise Rejection: RangeError: Maximum call stack size exceeded.

[leighmcculloch]

Also, it seems Go 1.21 wasip1 won't allow exporting functions to WASM:

• proposal: cmd/compile: go:wasmexport directive golang/go#42372