cmd/gomobile: sanitize android app package names

hyangah · hyangah · commit b39ed682d87b · 2015-11-18T17:26:55.000Z
https://docs.oracle.com/javase/tutorial/java/package/namingpkgs.html "This can occur if the domain name contains a hyphen or other special character, if the package name begins with a digit or other character that is illegal to use as the beginning of a Java name, or if the package name contains a reserved Java keyword, such as "int". In this event, the suggested convention is to add an underscore." The sanitized name is used for the app package name and the default apk file name. Update golang/go#12273 Change-Id: I76d7f423e87c54a5bb7ab71ec251fd3a26da9722 Reviewed-on: https://go-review.googlesource.com/16875 Reviewed-by: David Crawshaw <crawshaw@golang.org>
diff --git a/cmd/gomobile/build_androidapp.go b/cmd/gomobile/build_androidapp.go
@@ -22,25 +22,21 @@ import (
 )
 
 func goAndroidBuild(pkg *build.Package) (map[string]bool, error) {
-	libName := path.Base(pkg.ImportPath)
+	appName := path.Base(pkg.ImportPath)
+	libName := androidPkgName(appName)
 	manifestPath := filepath.Join(pkg.Dir, "AndroidManifest.xml")
 	manifestData, err := ioutil.ReadFile(manifestPath)
 	if err != nil {
 		if !os.IsNotExist(err) {
 			return nil, err
 		}
 
-		productName := rfc1034Label(libName)
-		if productName == "" {
-			productName = "ProductName" // like xcode.
-		}
-
 		buf := new(bytes.Buffer)
 		buf.WriteString(`<?xml version="1.0" encoding="utf-8"?>`)
 		err := manifestTmpl.Execute(buf, manifestTmplData{
 			// TODO(crawshaw): a better package path.
-			JavaPkgPath: "org.golang.todo." + productName,
-			Name:        strings.Title(libName),
+			JavaPkgPath: "org.golang.todo." + libName,
+			Name:        strings.Title(appName),
 			LibName:     libName,
 		})
 		if err != nil {
@@ -83,7 +79,7 @@ func goAndroidBuild(pkg *build.Package) (map[string]bool, error) {
 	}
 
 	if buildO == "" {
-		buildO = filepath.Base(pkg.Dir) + ".apk"
+		buildO = androidPkgName(filepath.Base(pkg.Dir)) + ".apk"
 	}
 	if !strings.HasSuffix(buildO, ".apk") {
 		return nil, fmt.Errorf("output file name %q does not end in '.apk'", buildO)
@@ -214,6 +210,51 @@ func goAndroidBuild(pkg *build.Package) (map[string]bool, error) {
 	return nmpkgs, nil
 }
 
+// androidPkgName sanitizes the go package name to be acceptable as a android
+// package name part. The android package name convention is similar to the
+// java package name convention described in
+// https://docs.oracle.com/javase/specs/jls/se8/html/jls-6.html#jls-6.5.3.1
+// but not exactly same.
+func androidPkgName(name string) string {
+	var res []rune
+	for i, r := range name {
+		switch {
+		case 'a' <= r && r <= 'z', 'A' <= r && r <= 'Z':
+			res = append(res, r)
+		case '0' <= r && r <= '9':
+			if i == 0 {
+				panic(fmt.Sprintf("package name %q is not a valid go package name", name))
+			}
+			res = append(res, r)
+		default:
+			res = append(res, '_')
+		}
+	}
+	if len(res) == 0 || res[0] == '_' {
+		// Android does not seem to allow the package part starting with _.
+		res = append([]rune{'g', 'o'}, res...)
+	}
+	s := string(res)
+	// Look for Java keywords that are not Go keywords, and avoid using
+	// them as a package name.
+	//
+	// This is not a problem for normal Go identifiers as we only expose
+	// exported symbols. The upper case first letter saves everything
+	// from accidentally matching except for the package name.
+	//
+	// Note that basic type names (like int) are not keywords in Go.
+	switch s {
+	case "abstract", "assert", "boolean", "byte", "catch", "char", "class",
+		"do", "double", "enum", "extends", "final", "finally", "float",
+		"implements", "instanceof", "int", "long", "native", "private",
+		"protected", "public", "short", "static", "strictfp", "super",
+		"synchronized", "this", "throw", "throws", "transient", "try",
+		"void", "volatile", "while":
+		s += "_"
+	}
+	return s
+}
+
 // A random uninteresting private key.
 // Must be consistent across builds so newer app versions can be installed.
 const debugCert = `
diff --git a/cmd/gomobile/build_test.go b/cmd/gomobile/build_test.go
@@ -36,6 +36,33 @@ func TestRFC1034Label(t *testing.T) {
 	}
 }
 
+func TestAndroidPkgName(t *testing.T) {
+	tests := []struct {
+		in, want string
+	}{
+		{"a", "a"},
+		{"a123", "a123"},
+		{"a.b.c", "a_b_c"},
+		{"a-b", "a_b"},
+		{"a:b", "a_b"},
+		{"a?b", "a_b"},
+		{"αβγ", "go___"},
+		{"💩", "go_"},
+		{"My App", "My_App"},
+		{"...", "go___"},
+		{".-.", "go___"},
+		{"abstract", "abstract_"},
+		{"Abstract", "Abstract"},
+	}
+
+	for _, tc := range tests {
+		if got := androidPkgName(tc.in); got != tc.want {
+			t.Errorf("len %d", len(tc.in))
+			t.Errorf("androidPkgName(%q) = %q, want %q", tc.in, got, tc.want)
+		}
+	}
+}
+
 func TestAndroidBuild(t *testing.T) {
 	buf := new(bytes.Buffer)
 	defer func() {
diff --git a/cmd/gomobile/install.go b/cmd/gomobile/install.go
@@ -42,7 +42,7 @@ func runInstall(cmd *command) error {
 		`adb`,
 		`install`,
 		`-r`,
-		filepath.Base(pkg.Dir)+`.apk`,
+		androidPkgName(filepath.Base(pkg.Dir))+`.apk`,
 	)
 	c.Stdout = os.Stdout
 	c.Stderr = os.Stderr

Original file line number	Diff line number	Diff line change
`@@ -42,7 +42,7 @@ func runInstall(cmd *command) error {`
`42`	`42`	`adb`,
`43`	`43`	`install`,
`44`	`44`	`-r`,
`45`		- filepath.Base(pkg.Dir)+`.apk`,
	`45`	+ androidPkgName(filepath.Base(pkg.Dir))+`.apk`,
`46`	`46`	`)`
`47`	`47`	`c.Stdout = os.Stdout`
`48`	`48`	`c.Stderr = os.Stderr`