5fae0fd76b
The componentized successor to wasi_snapshot_preview1 is not compatible with the prior imports or even error numbers. Before releasing wazero 1.0 we need to change this package to reflect that WASI 2 is effectively a different API. Fixes #263 Signed-off-by: Adrian Cole <adrian@tetrate.io>
61 lines
1.6 KiB
Go
61 lines
1.6 KiB
Go
package wasi_snapshot_preview1
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import (
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"context"
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"fmt"
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"log"
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"os"
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"github.com/tetratelabs/wazero"
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"github.com/tetratelabs/wazero/sys"
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)
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// This is an example of how to use WebAssembly System Interface (WASI) with its simplest function: "proc_exit".
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//
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// See https://github.com/tetratelabs/wazero/tree/main/examples/wasi for another example.
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func Example() {
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// Choose the context to use for function calls.
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ctx := context.Background()
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// Create a new WebAssembly Runtime.
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r := wazero.NewRuntime()
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// Instantiate WASI, which implements system I/O such as console output.
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wm, err := Instantiate(ctx, r)
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if err != nil {
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log.Panicln(err)
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}
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defer wm.Close(testCtx)
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// Compile the WebAssembly module using the default configuration.
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code, err := r.CompileModule(ctx, []byte(`
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(module
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(import "wasi_snapshot_preview1" "proc_exit" (func $wasi.proc_exit (param $rval i32)))
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(func $main
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i32.const 2 ;; push $rval onto the stack
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call $wasi.proc_exit ;; return a sys.ExitError to the caller
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)
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(export "_start" (func $main))
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)
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`), wazero.NewCompileConfig())
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if err != nil {
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log.Panicln(err)
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}
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defer code.Close(ctx)
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// InstantiateModule runs the "_start" function which is like a "main" function.
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// Override default configuration (which discards stdout).
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mod, err := r.InstantiateModule(ctx, code, wazero.NewModuleConfig().WithStdout(os.Stdout).WithName("wasi-demo"))
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if mod != nil {
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defer mod.Close(ctx)
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}
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// Print the exit code
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if exitErr, ok := err.(*sys.ExitError); ok {
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fmt.Printf("exit_code: %d\n", exitErr.ExitCode())
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}
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// Output:
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// exit_code: 2
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}
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