all: initial import from gio main repository

Signed-off-by: Elias Naur <mail@eliasnaur.com>
2026-07-07 02:15:32 +00:00 · 2022-04-24 13:06:19 +02:00
commit 6826ef0b64
27 changed files with 4487 additions and 0 deletions
@@ -0,0 +1,201 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"text/template"
+
+	"golang.org/x/tools/go/packages"
+)
+
+func buildJS(bi *buildInfo) error {
+	out := *destPath
+	if out == "" {
+		out = bi.name
+	}
+	if err := os.MkdirAll(out, 0700); err != nil {
+		return err
+	}
+	cmd := exec.Command(
+		"go",
+		"build",
+		"-ldflags="+bi.ldflags,
+		"-tags="+bi.tags,
+		"-o", filepath.Join(out, "main.wasm"),
+		bi.pkgPath,
+	)
+	cmd.Env = append(
+		os.Environ(),
+		"GOOS=js",
+		"GOARCH=wasm",
+	)
+	_, err := runCmd(cmd)
+	if err != nil {
+		return err
+	}
+
+	var faviconPath string
+	if _, err := os.Stat(bi.iconPath); err == nil {
+		// Copy icon to the output folder
+		icon, err := ioutil.ReadFile(bi.iconPath)
+		if err != nil {
+			return err
+		}
+		if err := ioutil.WriteFile(filepath.Join(out, filepath.Base(bi.iconPath)), icon, 0600); err != nil {
+			return err
+		}
+		faviconPath = filepath.Base(bi.iconPath)
+	}
+
+	indexTemplate, err := template.New("").Parse(jsIndex)
+	if err != nil {
+		return err
+	}
+
+	var b bytes.Buffer
+	if err := indexTemplate.Execute(&b, struct {
+		Name string
+		Icon string
+	}{
+		Name: bi.name,
+		Icon: faviconPath,
+	}); err != nil {
+		return err
+	}
+
+	if err := ioutil.WriteFile(filepath.Join(out, "index.html"), b.Bytes(), 0600); err != nil {
+		return err
+	}
+
+	goroot, err := runCmd(exec.Command("go", "env", "GOROOT"))
+	if err != nil {
+		return err
+	}
+	wasmJS := filepath.Join(goroot, "misc", "wasm", "wasm_exec.js")
+	if _, err := os.Stat(wasmJS); err != nil {
+		return fmt.Errorf("failed to find $GOROOT/misc/wasm/wasm_exec.js driver: %v", err)
+	}
+	pkgs, err := packages.Load(&packages.Config{
+		Mode: packages.NeedName | packages.NeedFiles | packages.NeedImports | packages.NeedDeps,
+		Env:  append(os.Environ(), "GOOS=js", "GOARCH=wasm"),
+	}, bi.pkgPath)
+	if err != nil {
+		return err
+	}
+	extraJS, err := findPackagesJS(pkgs[0], make(map[string]bool))
+	if err != nil {
+		return err
+	}
+
+	return mergeJSFiles(filepath.Join(out, "wasm.js"), append([]string{wasmJS}, extraJS...)...)
+}
+
+func findPackagesJS(p *packages.Package, visited map[string]bool) (extraJS []string, err error) {
+	if len(p.GoFiles) == 0 {
+		return nil, nil
+	}
+	js, err := filepath.Glob(filepath.Join(filepath.Dir(p.GoFiles[0]), "*_js.js"))
+	if err != nil {
+		return nil, err
+	}
+	extraJS = append(extraJS, js...)
+	for _, imp := range p.Imports {
+		if !visited[imp.ID] {
+			extra, err := findPackagesJS(imp, visited)
+			if err != nil {
+				return nil, err
+			}
+			extraJS = append(extraJS, extra...)
+			visited[imp.ID] = true
+		}
+	}
+	return extraJS, nil
+}
+
+// mergeJSFiles will merge all files into a single `wasm.js`. It will prepend the jsSetGo
+// and append the jsStartGo.
+func mergeJSFiles(dst string, files ...string) (err error) {
+	w, err := os.Create(dst)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if cerr := w.Close(); err != nil {
+			err = cerr
+		}
+	}()
+	_, err = io.Copy(w, strings.NewReader(jsSetGo))
+	if err != nil {
+		return err
+	}
+	for i := range files {
+		r, err := os.Open(files[i])
+		if err != nil {
+			return err
+		}
+		_, err = io.Copy(w, r)
+		r.Close()
+		if err != nil {
+			return err
+		}
+	}
+	_, err = io.Copy(w, strings.NewReader(jsStartGo))
+	return err
+}
+
+const (
+	jsIndex = `<!doctype html>
+<html>
+	<head>
+		<meta charset="utf-8">
+		<meta name="viewport" content="width=device-width, user-scalable=no">
+		<meta name="mobile-web-app-capable" content="yes">
+		{{ if .Icon }}<link rel="icon" href="{{.Icon}}" type="image/x-icon" />{{ end }}
+		{{ if .Name }}<title>{{.Name}}</title>{{ end }}
+		<script src="wasm.js"></script>
+		<style>
+			body,pre { margin:0;padding:0; }
+		</style>
+	</head>
+	<body>
+	</body>
+</html>`
+	// jsSetGo sets the `window.go` variable.
+	jsSetGo = `(() => {
+    window.go = {argv: [], env: {}, importObject: {go: {}}};
+	const argv = new URLSearchParams(location.search).get("argv");
+	if (argv) {
+		window.go["argv"] = argv.split(" ");
+	}
+})();`
+	// jsStartGo initializes the main.wasm.
+	jsStartGo = `(() => {
+	defaultGo = new Go();
+	Object.assign(defaultGo["argv"], defaultGo["argv"].concat(go["argv"]));
+	Object.assign(defaultGo["env"], go["env"]);
+	for (let key in go["importObject"]) {
+		if (typeof defaultGo["importObject"][key] === "undefined") {
+			defaultGo["importObject"][key] = {};
+		}
+		Object.assign(defaultGo["importObject"][key], go["importObject"][key]);
+	}
+	window.go = defaultGo;
+    if (!WebAssembly.instantiateStreaming) { // polyfill
+        WebAssembly.instantiateStreaming = async (resp, importObject) => {
+            const source = await (await resp).arrayBuffer();
+            return await WebAssembly.instantiate(source, importObject);
+        };
+    }
+    WebAssembly.instantiateStreaming(fetch("main.wasm"), go.importObject).then((result) => {
+        go.run(result.instance);
+    });
+})();`
+)