Support moving sources in srcjars in soong_zip

Add a -srcjar argument to soong_zip that causes it to read the
package statement of each .java file and use that to place the
source file at a path that matches the package.

Test: jar_test.go, zip_test.go
Change-Id: I36017e42445ba3b0a82a10a8d81e8ac0cca096f2
diff --git a/zip/cmd/main.go b/zip/cmd/main.go
index 6f40a3e..fba2e4b 100644
--- a/zip/cmd/main.go
+++ b/zip/cmd/main.go
@@ -136,6 +136,7 @@
 	writeIfChanged := flags.Bool("write_if_changed", false, "only update resultant .zip if it has changed")
 	ignoreMissingFiles := flags.Bool("ignore_missing_files", false, "continue if a requested file does not exist")
 	symlinks := flags.Bool("symlinks", true, "store symbolic links in zip instead of following them")
+	srcJar := flags.Bool("srcjar", false, "move .java files to locations that match their package statement")
 
 	parallelJobs := flags.Int("parallel", runtime.NumCPU(), "number of parallel threads to use")
 	cpuProfile := flags.String("cpuprofile", "", "write cpu profile to file")
@@ -191,6 +192,7 @@
 		FileArgs:                 fileArgsBuilder.FileArgs(),
 		OutputFilePath:           *out,
 		EmulateJar:               *emulateJar,
+		SrcJar:                   *srcJar,
 		AddDirectoryEntriesToZip: *directories,
 		CompressionLevel:         *compLevel,
 		ManifestSourcePath:       *manifest,
diff --git a/zip/zip.go b/zip/zip.go
index 1f5fe43..707c4ef 100644
--- a/zip/zip.go
+++ b/zip/zip.go
@@ -210,6 +210,7 @@
 	FileArgs                 []FileArg
 	OutputFilePath           string
 	EmulateJar               bool
+	SrcJar                   bool
 	AddDirectoryEntriesToZip bool
 	CompressionLevel         int
 	ManifestSourcePath       string
@@ -364,7 +365,7 @@
 		}
 	}
 
-	return z.write(w, pathMappings, args.ManifestSourcePath, args.EmulateJar, args.NumParallelJobs)
+	return z.write(w, pathMappings, args.ManifestSourcePath, args.EmulateJar, args.SrcJar, args.NumParallelJobs)
 }
 
 func Zip(args ZipArgs) error {
@@ -446,7 +447,9 @@
 	sort.SliceStable(mappings, less)
 }
 
-func (z *ZipWriter) write(f io.Writer, pathMappings []pathMapping, manifest string, emulateJar bool, parallelJobs int) error {
+func (z *ZipWriter) write(f io.Writer, pathMappings []pathMapping, manifest string, emulateJar, srcJar bool,
+	parallelJobs int) error {
+
 	z.errors = make(chan error)
 	defer close(z.errors)
 
@@ -489,7 +492,7 @@
 			if emulateJar && ele.dest == jar.ManifestFile {
 				err = z.addManifest(ele.dest, ele.src, ele.zipMethod)
 			} else {
-				err = z.addFile(ele.dest, ele.src, ele.zipMethod, emulateJar)
+				err = z.addFile(ele.dest, ele.src, ele.zipMethod, emulateJar, srcJar)
 			}
 			if err != nil {
 				z.errors <- err
@@ -588,7 +591,7 @@
 }
 
 // imports (possibly with compression) <src> into the zip at sub-path <dest>
-func (z *ZipWriter) addFile(dest, src string, method uint16, emulateJar bool) error {
+func (z *ZipWriter) addFile(dest, src string, method uint16, emulateJar, srcJar bool) error {
 	var fileSize int64
 	var executable bool
 
@@ -606,12 +609,9 @@
 			return nil
 		}
 		return err
-	} else if s.IsDir() {
-		if z.directories {
-			return z.writeDirectory(dest, src, emulateJar)
-		}
-		return nil
-	} else {
+	}
+
+	createParentDirs := func(dest, src string) error {
 		if err := z.writeDirectory(filepath.Dir(dest), src, emulateJar); err != nil {
 			return err
 		}
@@ -625,32 +625,64 @@
 
 		z.createdFiles[dest] = src
 
-		if s.Mode()&os.ModeSymlink != 0 {
-			return z.writeSymlink(dest, src)
-		} else if !s.Mode().IsRegular() {
-			return fmt.Errorf("%s is not a file, directory, or symlink", src)
+		return nil
+	}
+
+	if s.IsDir() {
+		if z.directories {
+			return z.writeDirectory(dest, src, emulateJar)
+		}
+		return nil
+	} else if s.Mode()&os.ModeSymlink != 0 {
+		err = createParentDirs(dest, src)
+		if err != nil {
+			return err
+		}
+
+		return z.writeSymlink(dest, src)
+	} else if s.Mode().IsRegular() {
+		r, err := z.fs.Open(src)
+		if err != nil {
+			return err
+		}
+
+		if srcJar && filepath.Ext(src) == ".java" {
+			// rewrite the destination using the package path if it can be determined
+			pkg, err := jar.JavaPackage(r, src)
+			if err != nil {
+				// ignore errors for now, leaving the file at in its original location in the zip
+			} else {
+				dest = filepath.Join(filepath.Join(strings.Split(pkg, ".")...), filepath.Base(src))
+			}
+
+			_, err = r.Seek(0, io.SeekStart)
+			if err != nil {
+				return err
+			}
 		}
 
 		fileSize = s.Size()
 		executable = s.Mode()&0100 != 0
-	}
 
-	r, err := z.fs.Open(src)
-	if err != nil {
-		return err
-	}
+		header := &zip.FileHeader{
+			Name:               dest,
+			Method:             method,
+			UncompressedSize64: uint64(fileSize),
+		}
 
-	header := &zip.FileHeader{
-		Name:               dest,
-		Method:             method,
-		UncompressedSize64: uint64(fileSize),
-	}
+		if executable {
+			header.SetMode(0700)
+		}
 
-	if executable {
-		header.SetMode(0700)
-	}
+		err = createParentDirs(dest, src)
+		if err != nil {
+			return err
+		}
 
-	return z.writeFileContents(header, r)
+		return z.writeFileContents(header, r)
+	} else {
+		return fmt.Errorf("%s is not a file, directory, or symlink", src)
+	}
 }
 
 func (z *ZipWriter) addManifest(dest string, src string, method uint16) error {
diff --git a/zip/zip_test.go b/zip/zip_test.go
index 93c5f3d..84317d1 100644
--- a/zip/zip_test.go
+++ b/zip/zip_test.go
@@ -40,14 +40,15 @@
 )
 
 var mockFs = pathtools.MockFs(map[string][]byte{
-	"a/a/a":            fileA,
-	"a/a/b":            fileB,
-	"a/a/c -> ../../c": nil,
-	"a/a/d -> b":       nil,
-	"c":                fileC,
-	"l":                []byte("a/a/a\na/a/b\nc\n"),
-	"l2":               []byte("missing\n"),
-	"manifest.txt":     fileCustomManifest,
+	"a/a/a":               fileA,
+	"a/a/b":               fileB,
+	"a/a/c -> ../../c":    nil,
+	"dangling -> missing": nil,
+	"a/a/d -> b":          nil,
+	"c":                   fileC,
+	"l":                   []byte("a/a/a\na/a/b\nc\n"),
+	"l2":                  []byte("missing\n"),
+	"manifest.txt":        fileCustomManifest,
 })
 
 func fh(name string, contents []byte, method uint16) zip.FileHeader {
@@ -210,6 +211,17 @@
 			},
 		},
 		{
+			name: "dangling symlinks",
+			args: fileArgsBuilder().
+				File("dangling"),
+			compressionLevel: 9,
+			storeSymlinks:    true,
+
+			files: []zip.FileHeader{
+				fhLink("dangling", "missing"),
+			},
+		},
+		{
 			name: "list",
 			args: fileArgsBuilder().
 				List("l"),
@@ -554,3 +566,70 @@
 		})
 	}
 }
+
+func TestSrcJar(t *testing.T) {
+	mockFs := pathtools.MockFs(map[string][]byte{
+		"wrong_package.java":       []byte("package foo;"),
+		"foo/correct_package.java": []byte("package foo;"),
+		"src/no_package.java":      nil,
+		"src2/parse_error.java":    []byte("error"),
+	})
+
+	want := []string{
+		"foo/",
+		"foo/wrong_package.java",
+		"foo/correct_package.java",
+		"no_package.java",
+		"src2/",
+		"src2/parse_error.java",
+	}
+
+	args := ZipArgs{}
+	args.FileArgs = NewFileArgsBuilder().File("**/*.java").FileArgs()
+
+	args.SrcJar = true
+	args.AddDirectoryEntriesToZip = true
+	args.Filesystem = mockFs
+	args.Stderr = &bytes.Buffer{}
+
+	buf := &bytes.Buffer{}
+	err := ZipTo(args, buf)
+	if err != nil {
+		t.Fatalf("got error %v", err)
+	}
+
+	br := bytes.NewReader(buf.Bytes())
+	zr, err := zip.NewReader(br, int64(br.Len()))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var got []string
+	for _, f := range zr.File {
+		r, err := f.Open()
+		if err != nil {
+			t.Fatalf("error when opening %s: %s", f.Name, err)
+		}
+
+		crc := crc32.NewIEEE()
+		len, err := io.Copy(crc, r)
+		r.Close()
+		if err != nil {
+			t.Fatalf("error when reading %s: %s", f.Name, err)
+		}
+
+		if uint64(len) != f.UncompressedSize64 {
+			t.Errorf("incorrect length for %s, want %d got %d", f.Name, f.UncompressedSize64, len)
+		}
+
+		if crc.Sum32() != f.CRC32 {
+			t.Errorf("incorrect crc for %s, want %x got %x", f.Name, f.CRC32, crc)
+		}
+
+		got = append(got, f.Name)
+	}
+
+	if !reflect.DeepEqual(want, got) {
+		t.Errorf("want files %q, got %q", want, got)
+	}
+}