func writeDocs(ctx *blueprint.Context, srcDir, filename string) error {
	// Find the module that's marked as the "primary builder", which means it's
	// creating the binary that we'll use to generate the non-bootstrap
	// build.ninja file.
	var primaryBuilders []*goBinary
	var minibp *goBinary
	ctx.VisitAllModulesIf(isBootstrapBinaryModule,
		func(module blueprint.Module) {
			binaryModule := module.(*goBinary)
			if binaryModule.properties.PrimaryBuilder {
				primaryBuilders = append(primaryBuilders, binaryModule)
			}
			if ctx.ModuleName(binaryModule) == "minibp" {
				minibp = binaryModule
			}
		})

	if minibp == nil {
		panic("missing minibp")
	}

	var primaryBuilder *goBinary
	switch len(primaryBuilders) {
	case 0:
		// If there's no primary builder module then that means we'll use minibp
		// as the primary builder.
		primaryBuilder = minibp

	case 1:
		primaryBuilder = primaryBuilders[0]

	default:
		return fmt.Errorf("multiple primary builder modules present")
	}

	pkgFiles := make(map[string][]string)
	ctx.VisitDepsDepthFirst(primaryBuilder, func(module blueprint.Module) {
		switch m := module.(type) {
		case (*goPackage):
			pkgFiles[m.properties.PkgPath] = pathtools.PrefixPaths(m.properties.Srcs,
				filepath.Join(srcDir, ctx.ModuleDir(m)))
		default:
			panic(fmt.Errorf("unknown dependency type %T", module))
		}
	})

	return bpdoc.Write(filename, pkgFiles, ctx.ModuleTypePropertyStructs())
}

// removeAbandonedFiles removes any files that appear in the Ninja log that are
// not currently build targets.
func removeAbandonedFiles(ctx *blueprint.Context, config *Config,
	srcDir, manifestFile string) error {

	buildDir := "."
	switch config.stage {
	case StageBootstrap:
		buildDir = miniBootstrapDir
	case StagePrimary:
		buildDir = bootstrapDir
	}

	targetRules, err := ctx.AllTargets()
	if err != nil {
		return fmt.Errorf("error determining target list: %s", err)
	}

	replacer := strings.NewReplacer(
		"@@[email protected]@", srcDir,
		"@@[email protected]@", BuildDir,
		"@@[email protected]@", manifestFile)
	targets := make(map[string]bool)
	for target := range targetRules {
		replacedTarget := replacer.Replace(target)
		targets[filepath.Clean(replacedTarget)] = true
	}

	filePaths, err := parseNinjaLog(buildDir)
	if err != nil {
		return err
	}

	for _, filePath := range filePaths {
		isTarget := targets[filePath]
		if !isTarget {
			err = removeFileAndEmptyDirs(filePath)
			if err != nil {
				return err
			}
		}
	}

	return nil
}

func Main(ctx *blueprint.Context, config interface{}, extraNinjaFileDeps ...string) {
	if !flag.Parsed() {
		flag.Parse()
	}

	runtime.GOMAXPROCS(runtime.NumCPU())

	if cpuprofile != "" {
		f, err := os.Create(cpuprofile)
		if err != nil {
			fatalf("error opening cpuprofile: %s", err)
		}
		pprof.StartCPUProfile(f)
		defer f.Close()
		defer pprof.StopCPUProfile()
	}

	if flag.NArg() != 1 {
		fatalf("no Blueprints file specified")
	}

	stage := StageMain
	if c, ok := config.(ConfigInterface); ok {
		if c.GeneratingBootstrapper() {
			stage = StageBootstrap
		}
		if c.GeneratingPrimaryBuilder() {
			stage = StagePrimary
		}
	}

	bootstrapConfig := &Config{
		stage: stage,
		topLevelBlueprintsFile: flag.Arg(0),
		runGoTests:             runGoTests,
	}

	ctx.RegisterModuleType("bootstrap_go_package", newGoPackageModuleFactory(bootstrapConfig))
	ctx.RegisterModuleType("bootstrap_core_go_binary", newGoBinaryModuleFactory(bootstrapConfig, StageBootstrap))
	ctx.RegisterModuleType("bootstrap_go_binary", newGoBinaryModuleFactory(bootstrapConfig, StagePrimary))
	ctx.RegisterTopDownMutator("bootstrap_stage", propagateStageBootstrap)
	ctx.RegisterSingletonType("bootstrap", newSingletonFactory(bootstrapConfig))

	deps, errs := ctx.ParseBlueprintsFiles(bootstrapConfig.topLevelBlueprintsFile)
	if len(errs) > 0 {
		fatalErrors(errs)
	}

	// Add extra ninja file dependencies
	deps = append(deps, extraNinjaFileDeps...)

	errs = ctx.ResolveDependencies(config)
	if len(errs) > 0 {
		fatalErrors(errs)
	}

	if docFile != "" {
		err := writeDocs(ctx, filepath.Dir(bootstrapConfig.topLevelBlueprintsFile), docFile)
		if err != nil {
			fatalErrors([]error{err})
		}
		return
	}

	extraDeps, errs := ctx.PrepareBuildActions(config)
	if len(errs) > 0 {
		fatalErrors(errs)
	}
	deps = append(deps, extraDeps...)

	buf := bytes.NewBuffer(nil)
	err := ctx.WriteBuildFile(buf)
	if err != nil {
		fatalf("error generating Ninja file contents: %s", err)
	}

	const outFilePermissions = 0666
	if timestampFile != "" {
		err := ioutil.WriteFile(timestampFile, []byte{}, outFilePermissions)
		if err != nil {
			fatalf("error writing %s: %s", timestampFile, err)
		}

		if timestampDepFile != "" {
			err := deptools.WriteDepFile(timestampDepFile, timestampFile, deps)
			if err != nil {
				fatalf("error writing depfile: %s", err)
			}
		}
	}

	err = ioutil.WriteFile(outFile, buf.Bytes(), outFilePermissions)
	if err != nil {
		fatalf("error writing %s: %s", outFile, err)
	}

	if depFile != "" {
		err := deptools.WriteDepFile(depFile, outFile, deps)
		if err != nil {
			fatalf("error writing depfile: %s", err)
//.........这里部分代码省略.........

func Main(ctx *blueprint.Context, config interface{}, extraNinjaFileDeps ...string) {
	if !flag.Parsed() {
		flag.Parse()
	}

	runtime.GOMAXPROCS(runtime.NumCPU())

	if cpuprofile != "" {
		f, err := os.Create(cpuprofile)
		if err != nil {
			fatalf("error opening cpuprofile: %s", err)
		}
		pprof.StartCPUProfile(f)
		defer f.Close()
		defer pprof.StopCPUProfile()
	}

	if flag.NArg() != 1 {
		fatalf("no Blueprints file specified")
	}

	generatingBootstrapper := false
	if c, ok := config.(ConfigInterface); ok {
		generatingBootstrapper = c.GeneratingBootstrapper()
	}

	bootstrapConfig := &Config{
		generatingBootstrapper: generatingBootstrapper,
		topLevelBlueprintsFile: flag.Arg(0),
		runGoTests:             runGoTests,
	}

	ctx.RegisterModuleType("bootstrap_go_package", newGoPackageModuleFactory(bootstrapConfig))
	ctx.RegisterModuleType("bootstrap_go_binary", newGoBinaryModuleFactory(bootstrapConfig))
	ctx.RegisterSingletonType("bootstrap", newSingletonFactory(bootstrapConfig))

	deps, errs := ctx.ParseBlueprintsFiles(bootstrapConfig.topLevelBlueprintsFile)
	if len(errs) > 0 {
		fatalErrors(errs)
	}

	// Add extra ninja file dependencies
	deps = append(deps, extraNinjaFileDeps...)

	errs = ctx.ResolveDependencies(config)
	if len(errs) > 0 {
		fatalErrors(errs)
	}

	if docFile != "" {
		err := writeDocs(ctx, filepath.Dir(bootstrapConfig.topLevelBlueprintsFile), docFile)
		if err != nil {
			fatalErrors([]error{err})
		}
		return
	}

	extraDeps, errs := ctx.PrepareBuildActions(config)
	if len(errs) > 0 {
		fatalErrors(errs)
	}
	deps = append(deps, extraDeps...)

	buf := bytes.NewBuffer(nil)
	err := ctx.WriteBuildFile(buf)
	if err != nil {
		fatalf("error generating Ninja file contents: %s", err)
	}

	const outFilePermissions = 0666
	err = ioutil.WriteFile(outFile, buf.Bytes(), outFilePermissions)
	if err != nil {
		fatalf("error writing %s: %s", outFile, err)
	}

	if checkFile != "" {
		checkData, err := ioutil.ReadFile(checkFile)
		if err != nil {
			fatalf("error reading %s: %s", checkFile, err)
		}

		matches := buf.Len() == len(checkData)
		if matches {
			for i, value := range buf.Bytes() {
				if value != checkData[i] {
					matches = false
					break
				}
			}
		}

		if matches {
			// The new file content matches the check-file content, so we set
			// the new file's mtime and atime to match that of the check-file.
			checkFileInfo, err := os.Stat(checkFile)
			if err != nil {
				fatalf("error stat'ing %s: %s", checkFile, err)
			}

			time := checkFileInfo.ModTime()
//.........这里部分代码省略.........