92ba4929e5
This drops the text format (%.wat) and renames InstantiateModuleFromCode to InstantiateModuleFromBinary as it is no longer ambiguous. We decided to stop supporting the text format as it isn't typically used in production, yet costs a lot of work to develop. Given the resources available and the increased work added with WebAssembly 2.0 and soon WASI 2, we can't afford to spend the time on it. The old parser is used only internally and will eventually be moved to its own repository named watzero, possibly towards archival. See #59 Signed-off-by: Adrian Cole <adrian@tetrate.io>
66 lines
1.9 KiB
Go
66 lines
1.9 KiB
Go
package main
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import (
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"context"
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_ "embed"
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"fmt"
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"log"
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"github.com/tetratelabs/wazero"
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"github.com/tetratelabs/wazero/api"
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)
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// needsImportWasm was generated by the following:
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// cd testdata; wat2wasm --debug-names needs_import.wat
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//go:embed testdata/needs_import.wasm
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var needsImportWasm []byte
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// main shows how to override a module or function name hard-coded in a
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// WebAssembly module. This is similar to what some tools call "linking".
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func main() {
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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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defer r.Close(ctx) // This closes everything this Runtime created.
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// Instantiate a Go-defined module named "assemblyscript" that exports a
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// function to close the module that calls "abort".
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host, err := r.NewModuleBuilder("assemblyscript").
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ExportFunction("abort", func(ctx context.Context, m api.Module, messageOffset, fileNameOffset, line, col uint32) {
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_ = m.CloseWithExitCode(ctx, 255)
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}).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 host.Close(ctx)
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// Compile the WebAssembly module, replacing the import "env.abort" with
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// "assemblyscript.abort".
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compileConfig := wazero.NewCompileConfig().
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WithImportRenamer(func(externType api.ExternType, oldModule, oldName string) (newModule, newName string) {
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if oldModule == "env" && oldName == "abort" {
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return "assemblyscript", "abort"
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}
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return oldModule, oldName
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})
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code, err := r.CompileModule(ctx, needsImportWasm, compileConfig)
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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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// Instantiate the WebAssembly module.
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mod, err := r.InstantiateModule(ctx, code, wazero.NewModuleConfig())
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if err != nil {
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log.Panicln(err)
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}
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defer mod.Close(ctx)
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// Since the above worked, the exported function closes the module.
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_, err = mod.ExportedFunction("abort").Call(ctx, 0, 0, 0, 0)
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fmt.Println(err)
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}
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