github.com/acrespo/mobile@v0.0.0-20190107162257-dc0771356504/cmd/gomobile/gendex.go (about)

     1  // Copyright 2015 The Go Authors.  All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // +build ignore
     6  
     7  // Gendex generates a dex file used by Go apps created with gomobile.
     8  //
     9  // The dex is a thin extension of NativeActivity, providing access to
    10  // a few platform features (not the SDK UI) not easily accessible from
    11  // NDK headers. Long term these could be made part of the standard NDK,
    12  // however that would limit gomobile to working with newer versions of
    13  // the Android OS, so we do this while we wait.
    14  //
    15  // Requires ANDROID_HOME be set to the path of the Android SDK, and
    16  // javac must be on the PATH.
    17  package main
    18  
    19  import (
    20  	"bytes"
    21  	"encoding/base64"
    22  	"errors"
    23  	"flag"
    24  	"fmt"
    25  	"go/format"
    26  	"io/ioutil"
    27  	"log"
    28  	"os"
    29  	"os/exec"
    30  	"path/filepath"
    31  )
    32  
    33  var outfile = flag.String("o", "", "result will be written file")
    34  
    35  var tmpdir string
    36  
    37  func main() {
    38  	flag.Parse()
    39  
    40  	var err error
    41  	tmpdir, err = ioutil.TempDir("", "gendex-")
    42  	if err != nil {
    43  		log.Fatal(err)
    44  	}
    45  
    46  	err = gendex()
    47  	os.RemoveAll(tmpdir)
    48  	if err != nil {
    49  		log.Fatal(err)
    50  	}
    51  }
    52  
    53  func gendex() error {
    54  	androidHome := os.Getenv("ANDROID_HOME")
    55  	if androidHome == "" {
    56  		return errors.New("ANDROID_HOME not set")
    57  	}
    58  	if err := os.MkdirAll(tmpdir+"/work/org/golang/app", 0775); err != nil {
    59  		return err
    60  	}
    61  	javaFiles, err := filepath.Glob("../../app/*.java")
    62  	if err != nil {
    63  		return err
    64  	}
    65  	if len(javaFiles) == 0 {
    66  		return errors.New("could not find ../../app/*.java files")
    67  	}
    68  	platform, err := findLast(androidHome + "/platforms")
    69  	if err != nil {
    70  		return err
    71  	}
    72  	cmd := exec.Command(
    73  		"javac",
    74  		"-source", "1.7",
    75  		"-target", "1.7",
    76  		"-bootclasspath", platform+"/android.jar",
    77  		"-d", tmpdir+"/work",
    78  	)
    79  	cmd.Args = append(cmd.Args, javaFiles...)
    80  	if out, err := cmd.CombinedOutput(); err != nil {
    81  		fmt.Println(cmd.Args)
    82  		os.Stderr.Write(out)
    83  		return err
    84  	}
    85  	buildTools, err := findLast(androidHome + "/build-tools")
    86  	if err != nil {
    87  		return err
    88  	}
    89  	cmd = exec.Command(
    90  		buildTools+"/dx",
    91  		"--dex",
    92  		"--output="+tmpdir+"/classes.dex",
    93  		tmpdir+"/work",
    94  	)
    95  	if out, err := cmd.CombinedOutput(); err != nil {
    96  		os.Stderr.Write(out)
    97  		return err
    98  	}
    99  	src, err := ioutil.ReadFile(tmpdir + "/classes.dex")
   100  	if err != nil {
   101  		return err
   102  	}
   103  	data := base64.StdEncoding.EncodeToString(src)
   104  
   105  	buf := new(bytes.Buffer)
   106  	fmt.Fprint(buf, header)
   107  
   108  	var piece string
   109  	for len(data) > 0 {
   110  		l := 70
   111  		if l > len(data) {
   112  			l = len(data)
   113  		}
   114  		piece, data = data[:l], data[l:]
   115  		fmt.Fprintf(buf, "\t`%s` + \n", piece)
   116  	}
   117  	fmt.Fprintf(buf, "\t``")
   118  	out, err := format.Source(buf.Bytes())
   119  	if err != nil {
   120  		buf.WriteTo(os.Stderr)
   121  		return err
   122  	}
   123  
   124  	w, err := os.Create(*outfile)
   125  	if err != nil {
   126  		return err
   127  	}
   128  	if _, err := w.Write(out); err != nil {
   129  		return err
   130  	}
   131  	if err := w.Close(); err != nil {
   132  		return err
   133  	}
   134  	return nil
   135  }
   136  
   137  func findLast(path string) (string, error) {
   138  	dir, err := os.Open(path)
   139  	if err != nil {
   140  		return "", err
   141  	}
   142  	children, err := dir.Readdirnames(-1)
   143  	if err != nil {
   144  		return "", err
   145  	}
   146  	return path + "/" + children[len(children)-1], nil
   147  }
   148  
   149  var header = `// Copyright 2015 The Go Authors.  All rights reserved.
   150  // Use of this source code is governed by a BSD-style
   151  // license that can be found in the LICENSE file.
   152  
   153  // Code generated by gendex.go. DO NOT EDIT.
   154  
   155  package main
   156  
   157  var dexStr = `