A mojom .d generator.

mojom/mojom_parser/generators/deps/deps_generator.go

Index: mojom/mojom_parser/generators/deps/deps_generator.go
diff --git a/mojom/mojom_parser/generators/deps/deps_generator.go b/mojom/mojom_parser/generators/deps/deps_generator.go
new file mode 100644
index 0000000000000000000000000000000000000000..c4744ab97d806a60d5cb061395f48cd8e0461bc2
--- /dev/null
+++ b/mojom/mojom_parser/generators/deps/deps_generator.go
@@ -0,0 +1,67 @@
+// Copyright 2016 The Chromium 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 main
+
+// deps_generator.go implements the main function of the deps generator.
+// The deps generator generates .d files. The syntax is that which is used to
+// specify dependencies in makefiles.
+
+import (
+	"log"
+	"os"
+	"path"
+	"path/filepath"
+
+	"mojom/mojom_parser/generators/common"
+)
+
+func main() {
+	config := common.GetCliConfig(os.Args)
+	common.GenerateOutput(WriteDepsFile, config)
+}
+
+// WriteDepsFile writes a .d file for the specified file.
+func WriteDepsFile(fileName string, config common.GeneratorConfig) {
+	writer := common.OutputWriterByFilePath(fileName, config, ".d")
+	dFileName := fileName[:len(fileName)-len(filepath.Ext(fileName))] + ".d"
+	writer.WriteString(path.Base(dFileName))
+	writer.WriteString(" : ")
+
+	imports := GetTransitiveClosure(fileName, config)
+	for _, imported := range imports {
+		writer.WriteString(imported)
+		writer.WriteString(" ")
+	}
+	writer.WriteString("\n")
+}
+
+// GetTransitiveClosure gets the list of transitive imports starting with
+// rootFile. rootFile itself is not included.
+// The imports are specified as paths relative to the directory in which
+// rootFile is found.
+func GetTransitiveClosure(rootFile string, config common.GeneratorConfig) (result []string) {
+	fileGraph := config.FileGraph()
+	toVisit := []string{rootFile}
+	rootFileDir := path.Dir(rootFile)
+
+	for len(toVisit) > 0 {
+		curFileName := toVisit[len(toVisit)-1]
+		toVisit = toVisit[1:len(toVisit)]
+
+		curFile := fileGraph.Files[curFileName]
+		rel, err := filepath.Rel(rootFileDir, curFileName)
+		if err != nil {
+			log.Fatalln(err.Error())
+		}
+		result = append(result, rel)
+
+		if curFile.Imports != nil {
+			for _, importFileName := range *curFile.Imports {
+				toVisit = append(toVisit, importFileName)
+			}
+		}
+	}
+	return
+}