bind: adjust invalid java package names

Updates golang/go#12273

Change-Id: I8eac3e84d5a473e9ffe45705cea88537573aef61
Reviewed-on: https://go-review.googlesource.com/13873
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>

bind/bind_test.go

@@ -28,6 +28,7 @@ var tests = []string{
 	"testdata/structs.go",
 	"testdata/interfaces.go",
 	"testdata/issue10788.go",
+	"testdata/try.go",
 }
 
 var fset = token.NewFileSet()

bind/genjava.go

@@ -11,8 +11,7 @@ import (
 	"go/types"
 	"io"
 	"regexp"
-	"unicode"
-	"unicode/utf8"
+	"strings"
 )
 
 // TODO(crawshaw): disallow basic android java type names in exported symbols.
@@ -546,15 +545,43 @@ import go.Seq;
 
 `
 
-func (g *javaGen) gen() error {
-	g.Printf(javaPreamble, g.pkg.Name(), g.pkg.Path(), g.pkg.Name())
+var javaNameReplacer = strings.NewReplacer(
+	"-", "_",
+	".", "_",
+)
+
+func (g *javaGen) javaPkgName() string {
+	s := javaNameReplacer.Replace(g.pkg.Name())
+	// 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
+}
 
-	firstRune, size := utf8.DecodeRuneInString(g.pkg.Name())
-	className := string(unicode.ToUpper(firstRune)) + g.pkg.Name()[size:]
+func (g *javaGen) className() string {
+	return strings.Title(javaNameReplacer.Replace(g.pkg.Name()))
+}
+
+func (g *javaGen) gen() error {
+	g.Printf(javaPreamble, g.javaPkgName(), g.pkg.Path(), g.javaPkgName())
 
-	g.Printf("public abstract class %s {\n", className)
+	g.Printf("public abstract class %s {\n", g.className())
 	g.Indent()
-	g.Printf("private %s() {} // uninstantiable\n\n", className)
+	g.Printf("private %s() {} // uninstantiable\n\n", g.className())
 	scope := g.pkg.Scope()
 	names := scope.Names()
 	var funcs []string

bind/testdata/try.go

@@ -0,0 +1,9 @@
+// Copyright 2015 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package try has a name that is a Java keyword.
+// Gobind has to translate it usefully. See Issue #12273.
+package try
+
+func This() string { return "This" }

bind/testdata/try.go.golden

@@ -0,0 +1,19 @@
+// Package go_try is an autogenerated binder stub for package try.
+//   gobind -lang=go try
+//
+// File is generated by gobind. Do not edit.
+package go_try
+
+import (
+	"golang.org/x/mobile/bind/seq"
+	"try"
+)
+
+func proxy_This(out, in *seq.Buffer) {
+	res := try.This()
+	out.WriteString(res)
+}
+
+func init() {
+	seq.Register("try", 1, proxy_This)
+}

bind/testdata/try.java.golden

@@ -0,0 +1,23 @@
+// Java Package try_ is a proxy for talking to a Go program.
+//   gobind -lang=java try
+//
+// File is generated by gobind. Do not edit.
+package go.try_;
+
+import go.Seq;
+
+public abstract class Try {
+    private Try() {} // uninstantiable
+
+    public static String This() {
+        go.Seq _in = new go.Seq();
+        go.Seq _out = new go.Seq();
+        String _result;
+        Seq.send(DESCRIPTOR, CALL_This, _in, _out);
+        _result = _out.readString();
+        return _result;
+    }
+
+    private static final int CALL_This = 1;
+    private static final String DESCRIPTOR = "try";
+}

bind/testdata/try.objc.h.golden

@@ -0,0 +1,13 @@
+// Objective-C API for talking to try Go package.
+//   gobind -lang=objc try
+//
+// File is generated by gobind. Do not edit.
+
+#ifndef __GoTry_H__
+#define __GoTry_H__
+
+#include <Foundation/Foundation.h>
+
+FOUNDATION_EXPORT NSString* GoTryThis();
+
+#endif

bind/testdata/try.objc.m.golden

@@ -0,0 +1,29 @@
+// Objective-C API for talking to try Go package.
+//   gobind -lang=objc try
+//
+// File is generated by gobind. Do not edit.
+
+#include "GoTry.h"
+#include <Foundation/Foundation.h>
+#include "seq.h"
+
+static NSString* errDomain = @"go.try";
+
+@protocol goSeqRefInterface
+-(GoSeqRef*) ref;
+@end
+
+#define _DESCRIPTOR_ "try"
+
+#define _CALL_This_ 1
+
+NSString* GoTryThis() {
+	GoSeq in_ = {};
+	GoSeq out_ = {};
+	go_seq_send(_DESCRIPTOR_, _CALL_This_, &in_, &out_);
+	NSString* ret0_ = go_seq_readUTF8(&out_);
+	go_seq_free(&in_);
+	go_seq_free(&out_);
+	return ret0_;
+}
+