ui/build/soong.go - LeafOS-Project/android_build_soong - Gitiles

 // Copyright 2017 Google Inc. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 package build

 import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strconv"

 	"android/soong/ui/metrics"
 	soong_metrics_proto "android/soong/ui/metrics/metrics_proto"
 	"android/soong/ui/status"

 	"android/soong/shared"

 	"github.com/google/blueprint"
 	"github.com/google/blueprint/bootstrap"
 	"github.com/google/blueprint/deptools"
 	"github.com/google/blueprint/microfactory"

 	"google.golang.org/protobuf/proto"
 )

 const (
 	availableEnvFile = "soong.environment.available"
 	usedEnvFile      = "soong.environment.used"
 )

 func writeEnvironmentFile(ctx Context, envFile string, envDeps map[string]string) error {
 	data, err := shared.EnvFileContents(envDeps)
 	if err != nil {
 		return err
 	}

 	return ioutil.WriteFile(envFile, data, 0644)
 }

 // This uses Android.bp files and various tools to generate <builddir>/build.ninja.
 //
 // However, the execution of <builddir>/build.ninja happens later in
 // build/soong/ui/build/build.go#Build()
 //
 // We want to rely on as few prebuilts as possible, so we need to bootstrap
 // Soong. The process is as follows:
 //
 // 1. We use "Microfactory", a simple tool to compile Go code, to build
 //    first itself, then soong_ui from soong_ui.bash. This binary contains
 //    parts of soong_build that are needed to build itself.
 // 2. This simplified version of soong_build then reads the Blueprint files
 //    that describe itself and emits .bootstrap/build.ninja that describes
 //    how to build its full version and use that to produce the final Ninja
 //    file Soong emits.
 // 3. soong_ui executes .bootstrap/build.ninja
 //
 // (After this, Kati is executed to parse the Makefiles, but that's not part of
 // bootstrapping Soong)

 // A tiny struct used to tell Blueprint that it's in bootstrap mode. It would
 // probably be nicer to use a flag in bootstrap.Args instead.
 type BlueprintConfig struct {
 	soongOutDir      string
 	outDir           string
 	debugCompilation bool
 }

 func (c BlueprintConfig) SoongOutDir() string {
 	return c.soongOutDir
 }

 func (c BlueprintConfig) OutDir() string {
 	return c.outDir
 }

 func (c BlueprintConfig) DebugCompilation() bool {
 	return c.debugCompilation
 }

 func environmentArgs(config Config, suffix string) []string {
 	return []string{
 		"--available_env", shared.JoinPath(config.SoongOutDir(), availableEnvFile),
 		"--used_env", shared.JoinPath(config.SoongOutDir(), usedEnvFile+suffix),
 	}
 }

 func writeEmptyGlobFile(ctx Context, path string) {
 	err := os.MkdirAll(filepath.Dir(path), 0777)
 	if err != nil {
 		ctx.Fatalf("Failed to create parent directories of empty ninja glob file '%s': %s", path, err)
 	}

 	if _, err := os.Stat(path); os.IsNotExist(err) {
 		err = ioutil.WriteFile(path, nil, 0666)
 		if err != nil {
 			ctx.Fatalf("Failed to create empty ninja glob file '%s': %s", path, err)
 		}
 	}
 }

 func bootstrapBlueprint(ctx Context, config Config) {
 	ctx.BeginTrace(metrics.RunSoong, "blueprint bootstrap")
 	defer ctx.EndTrace()

 	var args bootstrap.Args

 	bootstrapGlobFile := shared.JoinPath(config.SoongOutDir(), ".bootstrap/build-globs.ninja")
 	bp2buildGlobFile := shared.JoinPath(config.SoongOutDir(), ".bootstrap/build-globs.bp2build.ninja")

 	// The glob .ninja files are subninja'd. However, they are generated during
 	// the build itself so we write an empty file so that the subninja doesn't
 	// fail on clean builds
 	writeEmptyGlobFile(ctx, bootstrapGlobFile)
 	writeEmptyGlobFile(ctx, bp2buildGlobFile)
 	bootstrapDepFile := shared.JoinPath(config.SoongOutDir(), ".bootstrap/build.ninja.d")

 	args.RunGoTests = !config.skipSoongTests
 	args.UseValidations = true // Use validations to depend on tests
 	args.BuildDir = config.SoongOutDir()
 	args.NinjaBuildDir = config.OutDir()
 	args.TopFile = "Android.bp"
 	args.ModuleListFile = filepath.Join(config.FileListDir(), "Android.bp.list")
 	args.OutFile = shared.JoinPath(config.SoongOutDir(), ".bootstrap/build.ninja")
 	// The primary builder (aka soong_build) will use bootstrapGlobFile as the globFile to generate build.ninja(.d)
 	// Building soong_build does not require a glob file
 	// Using "" instead of "<soong_build_glob>.ninja" will ensure that an unused glob file is not written to out/soong/.bootstrap during StagePrimary
 	args.Subninjas = []string{bootstrapGlobFile, bp2buildGlobFile}
 	args.GeneratingPrimaryBuilder = true
 	args.EmptyNinjaFile = config.EmptyNinjaFile()

 	args.DelveListen = os.Getenv("SOONG_DELVE")
 	if args.DelveListen != "" {
 		args.DelvePath = shared.ResolveDelveBinary()
 	}

 	commonArgs := bootstrap.PrimaryBuilderExtraFlags(args, config.MainNinjaFile())
 	mainSoongBuildInputs := []string{"Android.bp"}

 	if config.bazelBuildMode() == mixedBuild {
 		mainSoongBuildInputs = append(mainSoongBuildInputs, config.Bp2BuildMarkerFile())
 	}

 	soongBuildArgs := []string{
 		"--globListDir", "globs",
 		"--globFile", bootstrapGlobFile,
 	}

 	soongBuildArgs = append(soongBuildArgs, commonArgs...)
 	soongBuildArgs = append(soongBuildArgs, environmentArgs(config, "")...)
 	soongBuildArgs = append(soongBuildArgs, "Android.bp")

 	mainSoongBuildInvocation := bootstrap.PrimaryBuilderInvocation{
 		Inputs:  mainSoongBuildInputs,
 		Outputs: []string{config.MainNinjaFile()},
 		Args:    soongBuildArgs,
 	}

 	bp2buildArgs := []string{
 		"--bp2build_marker", config.Bp2BuildMarkerFile(),
 		"--globListDir", "globs.bp2build",
 		"--globFile", bp2buildGlobFile,
 	}

 	bp2buildArgs = append(bp2buildArgs, commonArgs...)
 	bp2buildArgs = append(bp2buildArgs, environmentArgs(config, ".bp2build")...)
 	bp2buildArgs = append(bp2buildArgs, "Android.bp")

 	bp2buildInvocation := bootstrap.PrimaryBuilderInvocation{
 		Inputs:  []string{"Android.bp"},
 		Outputs: []string{config.Bp2BuildMarkerFile()},
 		Args:    bp2buildArgs,
 	}
 	args.PrimaryBuilderInvocations = []bootstrap.PrimaryBuilderInvocation{
 		bp2buildInvocation,
 		mainSoongBuildInvocation,
 	}

 	blueprintCtx := blueprint.NewContext()
 	blueprintCtx.SetIgnoreUnknownModuleTypes(true)
 	blueprintConfig := BlueprintConfig{
 		soongOutDir:      config.SoongOutDir(),
 		outDir:           config.OutDir(),
 		debugCompilation: os.Getenv("SOONG_DELVE") != "",
 	}

 	bootstrapDeps := bootstrap.RunBlueprint(args, blueprintCtx, blueprintConfig)
 	err := deptools.WriteDepFile(bootstrapDepFile, args.OutFile, bootstrapDeps)
 	if err != nil {
 		ctx.Fatalf("Error writing depfile '%s': %s", bootstrapDepFile, err)
 	}
 }

 func checkEnvironmentFile(currentEnv *Environment, envFile string) {
 	getenv := func(k string) string {
 		v, _ := currentEnv.Get(k)
 		return v
 	}
 	if stale, _ := shared.StaleEnvFile(envFile, getenv); stale {
 		os.Remove(envFile)
 	}
 }

 func runSoong(ctx Context, config Config) {
 	ctx.BeginTrace(metrics.RunSoong, "soong")
 	defer ctx.EndTrace()

 	// We have two environment files: .available is the one with every variable,
 	// .used with the ones that were actually used. The latter is used to
 	// determine whether Soong needs to be re-run since why re-run it if only
 	// unused variables were changed?
 	envFile := filepath.Join(config.SoongOutDir(), availableEnvFile)

 	dir := filepath.Join(config.SoongOutDir(), ".bootstrap")
 	if err := os.MkdirAll(dir, 0755); err != nil {
 		ctx.Fatalf("Cannot mkdir " + dir)
 	}

 	buildMode := config.bazelBuildMode()
 	integratedBp2Build := (buildMode == mixedBuild) || (buildMode == generateBuildFiles)

 	// This is done unconditionally, but does not take a measurable amount of time
 	bootstrapBlueprint(ctx, config)

 	soongBuildEnv := config.Environment().Copy()
 	soongBuildEnv.Set("TOP", os.Getenv("TOP"))
 	// For Bazel mixed builds.
 	soongBuildEnv.Set("BAZEL_PATH", "./tools/bazel")
 	soongBuildEnv.Set("BAZEL_HOME", filepath.Join(config.BazelOutDir(), "bazelhome"))
 	soongBuildEnv.Set("BAZEL_OUTPUT_BASE", filepath.Join(config.BazelOutDir(), "output"))
 	soongBuildEnv.Set("BAZEL_WORKSPACE", absPath(ctx, "."))
 	soongBuildEnv.Set("BAZEL_METRICS_DIR", config.BazelMetricsDir())

 	// For Soong bootstrapping tests
 	if os.Getenv("ALLOW_MISSING_DEPENDENCIES") == "true" {
 		soongBuildEnv.Set("ALLOW_MISSING_DEPENDENCIES", "true")
 	}

 	err := writeEnvironmentFile(ctx, envFile, soongBuildEnv.AsMap())
 	if err != nil {
 		ctx.Fatalf("failed to write environment file %s: %s", envFile, err)
 	}

 	func() {
 		ctx.BeginTrace(metrics.RunSoong, "environment check")
 		defer ctx.EndTrace()

 		soongBuildEnvFile := filepath.Join(config.SoongOutDir(), usedEnvFile)
 		checkEnvironmentFile(soongBuildEnv, soongBuildEnvFile)

 		if integratedBp2Build {
 			bp2buildEnvFile := filepath.Join(config.SoongOutDir(), usedEnvFile+".bp2build")
 			checkEnvironmentFile(soongBuildEnv, bp2buildEnvFile)
 		}
 	}()

 	runMicrofactory(ctx, config, ".bootstrap/bpglob", "github.com/google/blueprint/bootstrap/bpglob",
 		map[string]string{"github.com/google/blueprint": "build/blueprint"})

 	ninja := func(name, ninjaFile string, targets ...string) {
 		ctx.BeginTrace(metrics.RunSoong, name)
 		defer ctx.EndTrace()

 		fifo := filepath.Join(config.OutDir(), ".ninja_fifo")
 		nr := status.NewNinjaReader(ctx, ctx.Status.StartTool(), fifo)
 		defer nr.Close()

 		ninjaArgs := []string{
 			"-d", "keepdepfile",
 			"-d", "stats",
 			"-o", "usesphonyoutputs=yes",
 			"-o", "preremoveoutputs=yes",
 			"-w", "dupbuild=err",
 			"-w", "outputdir=err",
 			"-w", "missingoutfile=err",
 			"-j", strconv.Itoa(config.Parallel()),
 			"--frontend_file", fifo,
 			"-f", filepath.Join(config.SoongOutDir(), ninjaFile),
 		}

 		ninjaArgs = append(ninjaArgs, targets...)
 		cmd := Command(ctx, config, "soong "+name,
 			config.PrebuiltBuildTool("ninja"), ninjaArgs...)

 		var ninjaEnv Environment

 		// This is currently how the command line to invoke soong_build finds the
 		// root of the source tree and the output root
 		ninjaEnv.Set("TOP", os.Getenv("TOP"))

 		cmd.Environment = &ninjaEnv
 		cmd.Sandbox = soongSandbox
 		cmd.RunAndStreamOrFatal()
 	}

 	var target string

 	if config.bazelBuildMode() == generateBuildFiles {
 		target = config.Bp2BuildMarkerFile()
 	} else {
 		// This build generates <builddir>/build.ninja, which is used later by build/soong/ui/build/build.go#Build().
 		target = config.MainNinjaFile()
 	}

 	ninja("bootstrap", ".bootstrap/build.ninja", target)

 	var soongBuildMetrics *soong_metrics_proto.SoongBuildMetrics
 	if shouldCollectBuildSoongMetrics(config) {
 		soongBuildMetrics := loadSoongBuildMetrics(ctx, config)
 		logSoongBuildMetrics(ctx, soongBuildMetrics)
 	}

 	distGzipFile(ctx, config, config.SoongNinjaFile(), "soong")

 	if !config.SkipKati() {
 		distGzipFile(ctx, config, config.SoongAndroidMk(), "soong")
 		distGzipFile(ctx, config, config.SoongMakeVarsMk(), "soong")
 	}

 	if shouldCollectBuildSoongMetrics(config) && ctx.Metrics != nil {
 		ctx.Metrics.SetSoongBuildMetrics(soongBuildMetrics)
 	}
 }

 func runMicrofactory(ctx Context, config Config, relExePath string, pkg string, mapping map[string]string) {
 	name := filepath.Base(relExePath)
 	ctx.BeginTrace(metrics.RunSoong, name)
 	defer ctx.EndTrace()
 	cfg := microfactory.Config{TrimPath: absPath(ctx, ".")}
 	for pkgPrefix, pathPrefix := range mapping {
 		cfg.Map(pkgPrefix, pathPrefix)
 	}

 	exePath := filepath.Join(config.SoongOutDir(), relExePath)
 	dir := filepath.Dir(exePath)
 	if err := os.MkdirAll(dir, 0777); err != nil {
 		ctx.Fatalf("cannot create %s: %s", dir, err)
 	}
 	if _, err := microfactory.Build(&cfg, exePath, pkg); err != nil {
 		ctx.Fatalf("failed to build %s: %s", name, err)
 	}
 }

 func shouldCollectBuildSoongMetrics(config Config) bool {
 	// Do not collect metrics protobuf if the soong_build binary ran as the
 	// bp2build converter or the JSON graph dump.
 	return config.bazelBuildMode() != generateBuildFiles && config.bazelBuildMode() != generateJsonModuleGraph
 }

 func loadSoongBuildMetrics(ctx Context, config Config) *soong_metrics_proto.SoongBuildMetrics {
 	soongBuildMetricsFile := filepath.Join(config.OutDir(), "soong", "soong_build_metrics.pb")
 	buf, err := ioutil.ReadFile(soongBuildMetricsFile)
 	if err != nil {
 		ctx.Fatalf("Failed to load %s: %s", soongBuildMetricsFile, err)
 	}
 	soongBuildMetrics := &soong_metrics_proto.SoongBuildMetrics{}
 	err = proto.Unmarshal(buf, soongBuildMetrics)
 	if err != nil {
 		ctx.Fatalf("Failed to unmarshal %s: %s", soongBuildMetricsFile, err)
 	}
 	return soongBuildMetrics
 }

 func logSoongBuildMetrics(ctx Context, metrics *soong_metrics_proto.SoongBuildMetrics) {
 	ctx.Verbosef("soong_build metrics:")
 	ctx.Verbosef(" modules: %v", metrics.GetModules())
 	ctx.Verbosef(" variants: %v", metrics.GetVariants())
 	ctx.Verbosef(" max heap size: %v MB", metrics.GetMaxHeapSize()/1e6)
 	ctx.Verbosef(" total allocation count: %v", metrics.GetTotalAllocCount())
 	ctx.Verbosef(" total allocation size: %v MB", metrics.GetTotalAllocSize()/1e6)

 }
	// Copyright 2017 Google Inc. All rights reserved.
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	package build

	import (
	"io/ioutil"
	"os"
	"path/filepath"
	"strconv"

	"android/soong/ui/metrics"
	soong_metrics_proto "android/soong/ui/metrics/metrics_proto"
	"android/soong/ui/status"

	"android/soong/shared"

	"github.com/google/blueprint"
	"github.com/google/blueprint/bootstrap"
	"github.com/google/blueprint/deptools"
	"github.com/google/blueprint/microfactory"

	"google.golang.org/protobuf/proto"
	)

	const (
	availableEnvFile = "soong.environment.available"
	usedEnvFile = "soong.environment.used"
	)

	func writeEnvironmentFile(ctx Context, envFile string, envDeps map[string]string) error {
	data, err := shared.EnvFileContents(envDeps)
	if err != nil {
	return err
	}

	return ioutil.WriteFile(envFile, data, 0644)
	}

	// This uses Android.bp files and various tools to generate <builddir>/build.ninja.
	//
	// However, the execution of <builddir>/build.ninja happens later in
	// build/soong/ui/build/build.go#Build()
	//
	// We want to rely on as few prebuilts as possible, so we need to bootstrap
	// Soong. The process is as follows:
	//
	// 1. We use "Microfactory", a simple tool to compile Go code, to build
	// first itself, then soong_ui from soong_ui.bash. This binary contains
	// parts of soong_build that are needed to build itself.
	// 2. This simplified version of soong_build then reads the Blueprint files
	// that describe itself and emits .bootstrap/build.ninja that describes
	// how to build its full version and use that to produce the final Ninja
	// file Soong emits.
	// 3. soong_ui executes .bootstrap/build.ninja
	//
	// (After this, Kati is executed to parse the Makefiles, but that's not part of
	// bootstrapping Soong)

	// A tiny struct used to tell Blueprint that it's in bootstrap mode. It would
	// probably be nicer to use a flag in bootstrap.Args instead.
	type BlueprintConfig struct {
	soongOutDir string
	outDir string
	debugCompilation bool
	}

	func (c BlueprintConfig) SoongOutDir() string {
	return c.soongOutDir
	}

	func (c BlueprintConfig) OutDir() string {
	return c.outDir
	}

	func (c BlueprintConfig) DebugCompilation() bool {
	return c.debugCompilation
	}

	func environmentArgs(config Config, suffix string) []string {
	return []string{
	"--available_env", shared.JoinPath(config.SoongOutDir(), availableEnvFile),
	"--used_env", shared.JoinPath(config.SoongOutDir(), usedEnvFile+suffix),
	}
	}

	func writeEmptyGlobFile(ctx Context, path string) {
	err := os.MkdirAll(filepath.Dir(path), 0777)
	if err != nil {
	ctx.Fatalf("Failed to create parent directories of empty ninja glob file '%s': %s", path, err)
	}

	if _, err := os.Stat(path); os.IsNotExist(err) {
	err = ioutil.WriteFile(path, nil, 0666)
	if err != nil {
	ctx.Fatalf("Failed to create empty ninja glob file '%s': %s", path, err)
	}
	}
	}

	func bootstrapBlueprint(ctx Context, config Config) {
	ctx.BeginTrace(metrics.RunSoong, "blueprint bootstrap")
	defer ctx.EndTrace()

	var args bootstrap.Args

	bootstrapGlobFile := shared.JoinPath(config.SoongOutDir(), ".bootstrap/build-globs.ninja")
	bp2buildGlobFile := shared.JoinPath(config.SoongOutDir(), ".bootstrap/build-globs.bp2build.ninja")

	// The glob .ninja files are subninja'd. However, they are generated during
	// the build itself so we write an empty file so that the subninja doesn't
	// fail on clean builds
	writeEmptyGlobFile(ctx, bootstrapGlobFile)
	writeEmptyGlobFile(ctx, bp2buildGlobFile)
	bootstrapDepFile := shared.JoinPath(config.SoongOutDir(), ".bootstrap/build.ninja.d")

	args.RunGoTests = !config.skipSoongTests
	args.UseValidations = true // Use validations to depend on tests
	args.BuildDir = config.SoongOutDir()
	args.NinjaBuildDir = config.OutDir()
	args.TopFile = "Android.bp"
	args.ModuleListFile = filepath.Join(config.FileListDir(), "Android.bp.list")
	args.OutFile = shared.JoinPath(config.SoongOutDir(), ".bootstrap/build.ninja")
	// The primary builder (aka soong_build) will use bootstrapGlobFile as the globFile to generate build.ninja(.d)
	// Building soong_build does not require a glob file
	// Using "" instead of "<soong_build_glob>.ninja" will ensure that an unused glob file is not written to out/soong/.bootstrap during StagePrimary
	args.Subninjas = []string{bootstrapGlobFile, bp2buildGlobFile}
	args.GeneratingPrimaryBuilder = true
	args.EmptyNinjaFile = config.EmptyNinjaFile()

	args.DelveListen = os.Getenv("SOONG_DELVE")
	if args.DelveListen != "" {
	args.DelvePath = shared.ResolveDelveBinary()
	}

	commonArgs := bootstrap.PrimaryBuilderExtraFlags(args, config.MainNinjaFile())
	mainSoongBuildInputs := []string{"Android.bp"}

	if config.bazelBuildMode() == mixedBuild {
	mainSoongBuildInputs = append(mainSoongBuildInputs, config.Bp2BuildMarkerFile())
	}

	soongBuildArgs := []string{
	"--globListDir", "globs",
	"--globFile", bootstrapGlobFile,
	}

	soongBuildArgs = append(soongBuildArgs, commonArgs...)
	soongBuildArgs = append(soongBuildArgs, environmentArgs(config, "")...)
	soongBuildArgs = append(soongBuildArgs, "Android.bp")

	mainSoongBuildInvocation := bootstrap.PrimaryBuilderInvocation{
	Inputs: mainSoongBuildInputs,
	Outputs: []string{config.MainNinjaFile()},
	Args: soongBuildArgs,
	}

	bp2buildArgs := []string{
	"--bp2build_marker", config.Bp2BuildMarkerFile(),
	"--globListDir", "globs.bp2build",
	"--globFile", bp2buildGlobFile,
	}

	bp2buildArgs = append(bp2buildArgs, commonArgs...)
	bp2buildArgs = append(bp2buildArgs, environmentArgs(config, ".bp2build")...)
	bp2buildArgs = append(bp2buildArgs, "Android.bp")

	bp2buildInvocation := bootstrap.PrimaryBuilderInvocation{
	Inputs: []string{"Android.bp"},
	Outputs: []string{config.Bp2BuildMarkerFile()},
	Args: bp2buildArgs,
	}
	args.PrimaryBuilderInvocations = []bootstrap.PrimaryBuilderInvocation{
	bp2buildInvocation,
	mainSoongBuildInvocation,
	}

	blueprintCtx := blueprint.NewContext()
	blueprintCtx.SetIgnoreUnknownModuleTypes(true)
	blueprintConfig := BlueprintConfig{
	soongOutDir: config.SoongOutDir(),
	outDir: config.OutDir(),
	debugCompilation: os.Getenv("SOONG_DELVE") != "",
	}

	bootstrapDeps := bootstrap.RunBlueprint(args, blueprintCtx, blueprintConfig)
	err := deptools.WriteDepFile(bootstrapDepFile, args.OutFile, bootstrapDeps)
	if err != nil {
	ctx.Fatalf("Error writing depfile '%s': %s", bootstrapDepFile, err)
	}
	}

	func checkEnvironmentFile(currentEnv *Environment, envFile string) {
	getenv := func(k string) string {
	v, _ := currentEnv.Get(k)
	return v
	}
	if stale, _ := shared.StaleEnvFile(envFile, getenv); stale {
	os.Remove(envFile)
	}
	}

	func runSoong(ctx Context, config Config) {
	ctx.BeginTrace(metrics.RunSoong, "soong")
	defer ctx.EndTrace()

	// We have two environment files: .available is the one with every variable,
	// .used with the ones that were actually used. The latter is used to
	// determine whether Soong needs to be re-run since why re-run it if only
	// unused variables were changed?
	envFile := filepath.Join(config.SoongOutDir(), availableEnvFile)

	dir := filepath.Join(config.SoongOutDir(), ".bootstrap")
	if err := os.MkdirAll(dir, 0755); err != nil {
	ctx.Fatalf("Cannot mkdir " + dir)
	}

	buildMode := config.bazelBuildMode()
	integratedBp2Build := (buildMode == mixedBuild) \|\| (buildMode == generateBuildFiles)

	// This is done unconditionally, but does not take a measurable amount of time
	bootstrapBlueprint(ctx, config)

	soongBuildEnv := config.Environment().Copy()
	soongBuildEnv.Set("TOP", os.Getenv("TOP"))
	// For Bazel mixed builds.
	soongBuildEnv.Set("BAZEL_PATH", "./tools/bazel")
	soongBuildEnv.Set("BAZEL_HOME", filepath.Join(config.BazelOutDir(), "bazelhome"))
	soongBuildEnv.Set("BAZEL_OUTPUT_BASE", filepath.Join(config.BazelOutDir(), "output"))
	soongBuildEnv.Set("BAZEL_WORKSPACE", absPath(ctx, "."))
	soongBuildEnv.Set("BAZEL_METRICS_DIR", config.BazelMetricsDir())

	// For Soong bootstrapping tests
	if os.Getenv("ALLOW_MISSING_DEPENDENCIES") == "true" {
	soongBuildEnv.Set("ALLOW_MISSING_DEPENDENCIES", "true")
	}

	err := writeEnvironmentFile(ctx, envFile, soongBuildEnv.AsMap())
	if err != nil {
	ctx.Fatalf("failed to write environment file %s: %s", envFile, err)
	}

	func() {
	ctx.BeginTrace(metrics.RunSoong, "environment check")
	defer ctx.EndTrace()

	soongBuildEnvFile := filepath.Join(config.SoongOutDir(), usedEnvFile)
	checkEnvironmentFile(soongBuildEnv, soongBuildEnvFile)

	if integratedBp2Build {
	bp2buildEnvFile := filepath.Join(config.SoongOutDir(), usedEnvFile+".bp2build")
	checkEnvironmentFile(soongBuildEnv, bp2buildEnvFile)
	}
	}()

	runMicrofactory(ctx, config, ".bootstrap/bpglob", "github.com/google/blueprint/bootstrap/bpglob",
	map[string]string{"github.com/google/blueprint": "build/blueprint"})

	ninja := func(name, ninjaFile string, targets ...string) {
	ctx.BeginTrace(metrics.RunSoong, name)
	defer ctx.EndTrace()

	fifo := filepath.Join(config.OutDir(), ".ninja_fifo")
	nr := status.NewNinjaReader(ctx, ctx.Status.StartTool(), fifo)
	defer nr.Close()

	ninjaArgs := []string{
	"-d", "keepdepfile",
	"-d", "stats",
	"-o", "usesphonyoutputs=yes",
	"-o", "preremoveoutputs=yes",
	"-w", "dupbuild=err",
	"-w", "outputdir=err",
	"-w", "missingoutfile=err",
	"-j", strconv.Itoa(config.Parallel()),
	"--frontend_file", fifo,
	"-f", filepath.Join(config.SoongOutDir(), ninjaFile),
	}

	ninjaArgs = append(ninjaArgs, targets...)
	cmd := Command(ctx, config, "soong "+name,
	config.PrebuiltBuildTool("ninja"), ninjaArgs...)

	var ninjaEnv Environment

	// This is currently how the command line to invoke soong_build finds the
	// root of the source tree and the output root
	ninjaEnv.Set("TOP", os.Getenv("TOP"))

	cmd.Environment = &ninjaEnv
	cmd.Sandbox = soongSandbox
	cmd.RunAndStreamOrFatal()
	}

	var target string

	if config.bazelBuildMode() == generateBuildFiles {
	target = config.Bp2BuildMarkerFile()
	} else {
	// This build generates <builddir>/build.ninja, which is used later by build/soong/ui/build/build.go#Build().
	target = config.MainNinjaFile()
	}

	ninja("bootstrap", ".bootstrap/build.ninja", target)

	var soongBuildMetrics *soong_metrics_proto.SoongBuildMetrics
	if shouldCollectBuildSoongMetrics(config) {
	soongBuildMetrics := loadSoongBuildMetrics(ctx, config)
	logSoongBuildMetrics(ctx, soongBuildMetrics)
	}

	distGzipFile(ctx, config, config.SoongNinjaFile(), "soong")

	if !config.SkipKati() {
	distGzipFile(ctx, config, config.SoongAndroidMk(), "soong")
	distGzipFile(ctx, config, config.SoongMakeVarsMk(), "soong")
	}

	if shouldCollectBuildSoongMetrics(config) && ctx.Metrics != nil {
	ctx.Metrics.SetSoongBuildMetrics(soongBuildMetrics)
	}
	}

	func runMicrofactory(ctx Context, config Config, relExePath string, pkg string, mapping map[string]string) {
	name := filepath.Base(relExePath)
	ctx.BeginTrace(metrics.RunSoong, name)
	defer ctx.EndTrace()
	cfg := microfactory.Config{TrimPath: absPath(ctx, ".")}
	for pkgPrefix, pathPrefix := range mapping {
	cfg.Map(pkgPrefix, pathPrefix)
	}

	exePath := filepath.Join(config.SoongOutDir(), relExePath)
	dir := filepath.Dir(exePath)
	if err := os.MkdirAll(dir, 0777); err != nil {
	ctx.Fatalf("cannot create %s: %s", dir, err)
	}
	if _, err := microfactory.Build(&cfg, exePath, pkg); err != nil {
	ctx.Fatalf("failed to build %s: %s", name, err)
	}
	}

	func shouldCollectBuildSoongMetrics(config Config) bool {
	// Do not collect metrics protobuf if the soong_build binary ran as the
	// bp2build converter or the JSON graph dump.
	return config.bazelBuildMode() != generateBuildFiles && config.bazelBuildMode() != generateJsonModuleGraph
	}

	func loadSoongBuildMetrics(ctx Context, config Config) *soong_metrics_proto.SoongBuildMetrics {
	soongBuildMetricsFile := filepath.Join(config.OutDir(), "soong", "soong_build_metrics.pb")
	buf, err := ioutil.ReadFile(soongBuildMetricsFile)
	if err != nil {
	ctx.Fatalf("Failed to load %s: %s", soongBuildMetricsFile, err)
	}
	soongBuildMetrics := &soong_metrics_proto.SoongBuildMetrics{}
	err = proto.Unmarshal(buf, soongBuildMetrics)
	if err != nil {
	ctx.Fatalf("Failed to unmarshal %s: %s", soongBuildMetricsFile, err)
	}
	return soongBuildMetrics
	}

	func logSoongBuildMetrics(ctx Context, metrics *soong_metrics_proto.SoongBuildMetrics) {
	ctx.Verbosef("soong_build metrics:")
	ctx.Verbosef(" modules: %v", metrics.GetModules())
	ctx.Verbosef(" variants: %v", metrics.GetVariants())
	ctx.Verbosef(" max heap size: %v MB", metrics.GetMaxHeapSize()/1e6)
	ctx.Verbosef(" total allocation count: %v", metrics.GetTotalAllocCount())
	ctx.Verbosef(" total allocation size: %v MB", metrics.GetTotalAllocSize()/1e6)

	}