sysprop/sysprop_library.go - android_build_soong - Gitiles

 // Copyright (C) 2019 The Android Open Source Project
 //
 // 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 sysprop

 import (
 	"fmt"
 	"io"
 	"path"

 	"github.com/google/blueprint"
 	"github.com/google/blueprint/proptools"

 	"android/soong/android"
 	"android/soong/cc"
 	"android/soong/java"
 )

 type dependencyTag struct {
 	blueprint.BaseDependencyTag
 	name string
 }

 type syspropGenProperties struct {
 	Srcs  []string `android:"path"`
 	Scope string
 	Name  *string
 }

 type syspropJavaGenRule struct {
 	android.ModuleBase

 	properties syspropGenProperties

 	genSrcjars android.Paths
 }

 var _ android.OutputFileProducer = (*syspropJavaGenRule)(nil)

 var (
 	syspropJava = pctx.AndroidStaticRule("syspropJava",
 		blueprint.RuleParams{
 			Command: `rm -rf $out.tmp && mkdir -p $out.tmp && ` +
 				`$syspropJavaCmd --scope $scope --java-output-dir $out.tmp $in && ` +
 				`$soongZipCmd -jar -o $out -C $out.tmp -D $out.tmp && rm -rf $out.tmp`,
 			CommandDeps: []string{
 				"$syspropJavaCmd",
 				"$soongZipCmd",
 			},
 		}, "scope")
 )

 func init() {
 	pctx.HostBinToolVariable("soongZipCmd", "soong_zip")
 	pctx.HostBinToolVariable("syspropJavaCmd", "sysprop_java")

 	android.PreArchMutators(func(ctx android.RegisterMutatorsContext) {
 		ctx.BottomUp("sysprop_deps", syspropDepsMutator).Parallel()
 	})
 }

 func (g *syspropJavaGenRule) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	var checkApiFileTimeStamp android.WritablePath

 	ctx.VisitDirectDeps(func(dep android.Module) {
 		if m, ok := dep.(*syspropLibrary); ok {
 			checkApiFileTimeStamp = m.checkApiFileTimeStamp
 		}
 	})

 	for _, syspropFile := range android.PathsForModuleSrc(ctx, g.properties.Srcs) {
 		srcJarFile := android.GenPathWithExt(ctx, "sysprop", syspropFile, "srcjar")

 		ctx.Build(pctx, android.BuildParams{
 			Rule:        syspropJava,
 			Description: "sysprop_java " + syspropFile.Rel(),
 			Output:      srcJarFile,
 			Input:       syspropFile,
 			Implicit:    checkApiFileTimeStamp,
 			Args: map[string]string{
 				"scope": g.properties.Scope,
 			},
 		})

 		g.genSrcjars = append(g.genSrcjars, srcJarFile)
 	}
 }

 func (g *syspropJavaGenRule) OutputFiles(tag string) (android.Paths, error) {
 	switch tag {
 	case "":
 		return g.genSrcjars, nil
 	default:
 		return nil, fmt.Errorf("unsupported module reference tag %q", tag)
 	}
 }

 func syspropJavaGenFactory() android.Module {
 	g := &syspropJavaGenRule{}
 	g.AddProperties(&g.properties)
 	android.InitAndroidModule(g)
 	return g
 }

 type syspropLibrary struct {
 	android.ModuleBase
 	android.ApexModuleBase

 	properties syspropLibraryProperties

 	checkApiFileTimeStamp android.WritablePath
 	latestApiFile         android.Path
 	currentApiFile        android.Path
 	dumpedApiFile         android.WritablePath
 }

 type syspropLibraryProperties struct {
 	// Determine who owns this sysprop library. Possible values are
 	// "Platform", "Vendor", or "Odm"
 	Property_owner string

 	// list of package names that will be documented and publicized as API
 	Api_packages []string

 	// If set to true, allow this module to be dexed and installed on devices.
 	Installable *bool

 	// Make this module available when building for recovery
 	Recovery_available *bool

 	// Make this module available when building for vendor
 	Vendor_available *bool

 	// list of .sysprop files which defines the properties.
 	Srcs []string `android:"path"`

 	// If set to true, build a variant of the module for the host.  Defaults to false.
 	Host_supported *bool

 	// Whether public stub exists or not.
 	Public_stub *bool `blueprint:"mutated"`

 	Cpp struct {
 		// Minimum sdk version that the artifact should support when it runs as part of mainline modules(APEX).
 		// Forwarded to cc_library.min_sdk_version
 		Min_sdk_version *string
 	}
 }

 var (
 	pctx         = android.NewPackageContext("android/soong/sysprop")
 	syspropCcTag = dependencyTag{name: "syspropCc"}
 )

 func init() {
 	android.RegisterModuleType("sysprop_library", syspropLibraryFactory)
 }

 func (m *syspropLibrary) Name() string {
 	return m.BaseModuleName() + "_sysprop_library"
 }

 func (m *syspropLibrary) Owner() string {
 	return m.properties.Property_owner
 }

 func (m *syspropLibrary) CcModuleName() string {
 	return "lib" + m.BaseModuleName()
 }

 func (m *syspropLibrary) JavaPublicStubName() string {
 	if proptools.Bool(m.properties.Public_stub) {
 		return m.BaseModuleName() + "_public"
 	}
 	return ""
 }

 func (m *syspropLibrary) javaGenModuleName() string {
 	return m.BaseModuleName() + "_java_gen"
 }

 func (m *syspropLibrary) javaGenPublicStubName() string {
 	return m.BaseModuleName() + "_java_gen_public"
 }

 func (m *syspropLibrary) BaseModuleName() string {
 	return m.ModuleBase.Name()
 }

 func (m *syspropLibrary) HasPublicStub() bool {
 	return proptools.Bool(m.properties.Public_stub)
 }

 func (m *syspropLibrary) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	baseModuleName := m.BaseModuleName()

 	for _, syspropFile := range android.PathsForModuleSrc(ctx, m.properties.Srcs) {
 		if syspropFile.Ext() != ".sysprop" {
 			ctx.PropertyErrorf("srcs", "srcs contains non-sysprop file %q", syspropFile.String())
 		}
 	}

 	if ctx.Failed() {
 		return
 	}

 	m.currentApiFile = android.PathForSource(ctx, ctx.ModuleDir(), "api", baseModuleName+"-current.txt")
 	m.latestApiFile = android.PathForSource(ctx, ctx.ModuleDir(), "api", baseModuleName+"-latest.txt")

 	// dump API rule
 	rule := android.NewRuleBuilder()
 	m.dumpedApiFile = android.PathForModuleOut(ctx, "api-dump.txt")
 	rule.Command().
 		BuiltTool(ctx, "sysprop_api_dump").
 		Output(m.dumpedApiFile).
 		Inputs(android.PathsForModuleSrc(ctx, m.properties.Srcs))
 	rule.Build(pctx, ctx, baseModuleName+"_api_dump", baseModuleName+" api dump")

 	// check API rule
 	rule = android.NewRuleBuilder()

 	// 1. current.txt <-> api_dump.txt
 	msg := fmt.Sprintf(`\n******************************\n`+
 		`API of sysprop_library %s doesn't match with current.txt\n`+
 		`Please update current.txt by:\n`+
 		`m %s-dump-api && rm -rf %q && cp -f %q %q\n`+
 		`******************************\n`, baseModuleName, baseModuleName,
 		m.currentApiFile.String(), m.dumpedApiFile.String(), m.currentApiFile.String())

 	rule.Command().
 		Text("( cmp").Flag("-s").
 		Input(m.dumpedApiFile).
 		Input(m.currentApiFile).
 		Text("|| ( echo").Flag("-e").
 		Flag(`"` + msg + `"`).
 		Text("; exit 38) )")

 	// 2. current.txt <-> latest.txt
 	msg = fmt.Sprintf(`\n******************************\n`+
 		`API of sysprop_library %s doesn't match with latest version\n`+
 		`Please fix the breakage and rebuild.\n`+
 		`******************************\n`, baseModuleName)

 	rule.Command().
 		Text("( ").
 		BuiltTool(ctx, "sysprop_api_checker").
 		Input(m.latestApiFile).
 		Input(m.currentApiFile).
 		Text(" || ( echo").Flag("-e").
 		Flag(`"` + msg + `"`).
 		Text("; exit 38) )")

 	m.checkApiFileTimeStamp = android.PathForModuleOut(ctx, "check_api.timestamp")

 	rule.Command().
 		Text("touch").
 		Output(m.checkApiFileTimeStamp)

 	rule.Build(pctx, ctx, baseModuleName+"_check_api", baseModuleName+" check api")
 }

 func (m *syspropLibrary) AndroidMk() android.AndroidMkData {
 	return android.AndroidMkData{
 		Custom: func(w io.Writer, name, prefix, moduleDir string, data android.AndroidMkData) {
 			// sysprop_library module itself is defined as a FAKE module to perform API check.
 			// Actual implementation libraries are created on LoadHookMutator
 			fmt.Fprintln(w, "\ninclude $(CLEAR_VARS)")
 			fmt.Fprintf(w, "LOCAL_MODULE := %s\n", m.Name())
 			fmt.Fprintf(w, "LOCAL_MODULE_CLASS := FAKE\n")
 			fmt.Fprintf(w, "LOCAL_MODULE_TAGS := optional\n")
 			fmt.Fprintf(w, "include $(BUILD_SYSTEM)/base_rules.mk\n\n")
 			fmt.Fprintf(w, "$(LOCAL_BUILT_MODULE): %s\n", m.checkApiFileTimeStamp.String())
 			fmt.Fprintf(w, "\ttouch $@\n\n")
 			fmt.Fprintf(w, ".PHONY: %s-check-api %s-dump-api\n\n", name, name)

 			// dump API rule
 			fmt.Fprintf(w, "%s-dump-api: %s\n\n", name, m.dumpedApiFile.String())

 			// check API rule
 			fmt.Fprintf(w, "%s-check-api: %s\n\n", name, m.checkApiFileTimeStamp.String())
 		}}
 }

 // sysprop_library creates schematized APIs from sysprop description files (.sysprop).
 // Both Java and C++ modules can link against sysprop_library, and API stability check
 // against latest APIs (see build/soong/scripts/freeze-sysprop-api-files.sh)
 // is performed.
 func syspropLibraryFactory() android.Module {
 	m := &syspropLibrary{}

 	m.AddProperties(
 		&m.properties,
 	)
 	android.InitAndroidModule(m)
 	android.InitApexModule(m)
 	android.AddLoadHook(m, func(ctx android.LoadHookContext) { syspropLibraryHook(ctx, m) })
 	return m
 }

 type ccLibraryProperties struct {
 	Name             *string
 	Srcs             []string
 	Soc_specific     *bool
 	Device_specific  *bool
 	Product_specific *bool
 	Sysprop          struct {
 		Platform *bool
 	}
 	Target struct {
 		Android struct {
 			Header_libs []string
 			Shared_libs []string
 		}
 		Host struct {
 			Static_libs []string
 		}
 	}
 	Required           []string
 	Recovery           *bool
 	Recovery_available *bool
 	Vendor_available   *bool
 	Host_supported     *bool
 	Apex_available     []string
 	Min_sdk_version    *string
 }

 type javaLibraryProperties struct {
 	Name             *string
 	Srcs             []string
 	Soc_specific     *bool
 	Device_specific  *bool
 	Product_specific *bool
 	Required         []string
 	Sdk_version      *string
 	Installable      *bool
 	Libs             []string
 	Stem             *string
 }

 func syspropLibraryHook(ctx android.LoadHookContext, m *syspropLibrary) {
 	if len(m.properties.Srcs) == 0 {
 		ctx.PropertyErrorf("srcs", "sysprop_library must specify srcs")
 	}

 	missing_api := false

 	for _, txt := range []string{"-current.txt", "-latest.txt"} {
 		path := path.Join(ctx.ModuleDir(), "api", m.BaseModuleName()+txt)
 		file := android.ExistentPathForSource(ctx, path)
 		if !file.Valid() {
 			ctx.ModuleErrorf("API file %#v doesn't exist", path)
 			missing_api = true
 		}
 	}

 	if missing_api {
 		script := "build/soong/scripts/gen-sysprop-api-files.sh"
 		p := android.ExistentPathForSource(ctx, script)

 		if !p.Valid() {
 			panic(fmt.Sprintf("script file %s doesn't exist", script))
 		}

 		ctx.ModuleErrorf("One or more api files are missing. "+
 			"You can create them by:\n"+
 			"%s %q %q", script, ctx.ModuleDir(), m.BaseModuleName())
 		return
 	}

 	// ctx's Platform or Specific functions represent where this sysprop_library installed.
 	installedInSystem := ctx.Platform() || ctx.SystemExtSpecific()
 	installedInVendorOrOdm := ctx.SocSpecific() || ctx.DeviceSpecific()
 	isOwnerPlatform := false
 	stub := "sysprop-library-stub-"

 	switch m.Owner() {
 	case "Platform":
 		// Every partition can access platform-defined properties
 		stub += "platform"
 		isOwnerPlatform = true
 	case "Vendor":
 		// System can't access vendor's properties
 		if installedInSystem {
 			ctx.ModuleErrorf("None of soc_specific, device_specific, product_specific is true. " +
 				"System can't access sysprop_library owned by Vendor")
 		}
 		stub += "vendor"
 	case "Odm":
 		// Only vendor can access Odm-defined properties
 		if !installedInVendorOrOdm {
 			ctx.ModuleErrorf("Neither soc_speicifc nor device_specific is true. " +
 				"Odm-defined properties should be accessed only in Vendor or Odm")
 		}
 		stub += "vendor"
 	default:
 		ctx.PropertyErrorf("property_owner",
 			"Unknown value %s: must be one of Platform, Vendor or Odm", m.Owner())
 	}

 	ccProps := ccLibraryProperties{}
 	ccProps.Name = proptools.StringPtr(m.CcModuleName())
 	ccProps.Srcs = m.properties.Srcs
 	ccProps.Soc_specific = proptools.BoolPtr(ctx.SocSpecific())
 	ccProps.Device_specific = proptools.BoolPtr(ctx.DeviceSpecific())
 	ccProps.Product_specific = proptools.BoolPtr(ctx.ProductSpecific())
 	ccProps.Sysprop.Platform = proptools.BoolPtr(isOwnerPlatform)
 	ccProps.Target.Android.Header_libs = []string{"libbase_headers"}
 	ccProps.Target.Android.Shared_libs = []string{"liblog"}
 	ccProps.Target.Host.Static_libs = []string{"libbase", "liblog"}
 	ccProps.Recovery_available = m.properties.Recovery_available
 	ccProps.Vendor_available = m.properties.Vendor_available
 	ccProps.Host_supported = m.properties.Host_supported
 	ccProps.Apex_available = m.ApexProperties.Apex_available
 	ccProps.Min_sdk_version = m.properties.Cpp.Min_sdk_version
 	ctx.CreateModule(cc.LibraryFactory, &ccProps)

 	scope := "internal"

 	// We need to only use public version, if the partition where sysprop_library will be installed
 	// is different from owner.

 	if ctx.ProductSpecific() {
 		// Currently product partition can't own any sysprop_library.
 		scope = "public"
 	} else if isOwnerPlatform && installedInVendorOrOdm {
 		// Vendor or Odm should use public version of Platform's sysprop_library.
 		scope = "public"
 	}

 	ctx.CreateModule(syspropJavaGenFactory, &syspropGenProperties{
 		Srcs:  m.properties.Srcs,
 		Scope: scope,
 		Name:  proptools.StringPtr(m.javaGenModuleName()),
 	})

 	ctx.CreateModule(java.LibraryFactory, &javaLibraryProperties{
 		Name:             proptools.StringPtr(m.BaseModuleName()),
 		Srcs:             []string{":" + m.javaGenModuleName()},
 		Soc_specific:     proptools.BoolPtr(ctx.SocSpecific()),
 		Device_specific:  proptools.BoolPtr(ctx.DeviceSpecific()),
 		Product_specific: proptools.BoolPtr(ctx.ProductSpecific()),
 		Installable:      m.properties.Installable,
 		Sdk_version:      proptools.StringPtr("core_current"),
 		Libs:             []string{stub},
 	})

 	// if platform sysprop_library is installed in /system or /system-ext, we regard it as an API
 	// and allow any modules (even from different partition) to link against the sysprop_library.
 	// To do that, we create a public stub and expose it to modules with sdk_version: system_*.
 	if isOwnerPlatform && installedInSystem {
 		m.properties.Public_stub = proptools.BoolPtr(true)
 		ctx.CreateModule(syspropJavaGenFactory, &syspropGenProperties{
 			Srcs:  m.properties.Srcs,
 			Scope: "public",
 			Name:  proptools.StringPtr(m.javaGenPublicStubName()),
 		})

 		ctx.CreateModule(java.LibraryFactory, &javaLibraryProperties{
 			Name:        proptools.StringPtr(m.JavaPublicStubName()),
 			Srcs:        []string{":" + m.javaGenPublicStubName()},
 			Installable: proptools.BoolPtr(false),
 			Sdk_version: proptools.StringPtr("core_current"),
 			Libs:        []string{stub},
 			Stem:        proptools.StringPtr(m.BaseModuleName()),
 		})
 	}
 }

 func syspropDepsMutator(ctx android.BottomUpMutatorContext) {
 	if m, ok := ctx.Module().(*syspropLibrary); ok {
 		ctx.AddReverseDependency(m, nil, m.javaGenModuleName())

 		if proptools.Bool(m.properties.Public_stub) {
 			ctx.AddReverseDependency(m, nil, m.javaGenPublicStubName())
 		}
 	}
 }
	// Copyright (C) 2019 The Android Open Source Project
	//
	// 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 sysprop

	import (
	"fmt"
	"io"
	"path"

	"github.com/google/blueprint"
	"github.com/google/blueprint/proptools"

	"android/soong/android"
	"android/soong/cc"
	"android/soong/java"
	)

	type dependencyTag struct {
	blueprint.BaseDependencyTag
	name string
	}

	type syspropGenProperties struct {
	Srcs []string `android:"path"`
	Scope string
	Name *string
	}

	type syspropJavaGenRule struct {
	android.ModuleBase

	properties syspropGenProperties

	genSrcjars android.Paths
	}

	var _ android.OutputFileProducer = (*syspropJavaGenRule)(nil)

	var (
	syspropJava = pctx.AndroidStaticRule("syspropJava",
	blueprint.RuleParams{
	Command: `rm -rf $out.tmp && mkdir -p $out.tmp && ` +
	`$syspropJavaCmd --scope $scope --java-output-dir $out.tmp $in && ` +
	`$soongZipCmd -jar -o $out -C $out.tmp -D $out.tmp && rm -rf $out.tmp`,
	CommandDeps: []string{
	"$syspropJavaCmd",
	"$soongZipCmd",
	},
	}, "scope")
	)

	func init() {
	pctx.HostBinToolVariable("soongZipCmd", "soong_zip")
	pctx.HostBinToolVariable("syspropJavaCmd", "sysprop_java")

	android.PreArchMutators(func(ctx android.RegisterMutatorsContext) {
	ctx.BottomUp("sysprop_deps", syspropDepsMutator).Parallel()
	})
	}

	func (g *syspropJavaGenRule) GenerateAndroidBuildActions(ctx android.ModuleContext) {
	var checkApiFileTimeStamp android.WritablePath

	ctx.VisitDirectDeps(func(dep android.Module) {
	if m, ok := dep.(*syspropLibrary); ok {
	checkApiFileTimeStamp = m.checkApiFileTimeStamp
	}
	})

	for _, syspropFile := range android.PathsForModuleSrc(ctx, g.properties.Srcs) {
	srcJarFile := android.GenPathWithExt(ctx, "sysprop", syspropFile, "srcjar")

	ctx.Build(pctx, android.BuildParams{
	Rule: syspropJava,
	Description: "sysprop_java " + syspropFile.Rel(),
	Output: srcJarFile,
	Input: syspropFile,
	Implicit: checkApiFileTimeStamp,
	Args: map[string]string{
	"scope": g.properties.Scope,
	},
	})

	g.genSrcjars = append(g.genSrcjars, srcJarFile)
	}
	}

	func (g *syspropJavaGenRule) OutputFiles(tag string) (android.Paths, error) {
	switch tag {
	case "":
	return g.genSrcjars, nil
	default:
	return nil, fmt.Errorf("unsupported module reference tag %q", tag)
	}
	}

	func syspropJavaGenFactory() android.Module {
	g := &syspropJavaGenRule{}
	g.AddProperties(&g.properties)
	android.InitAndroidModule(g)
	return g
	}

	type syspropLibrary struct {
	android.ModuleBase
	android.ApexModuleBase

	properties syspropLibraryProperties

	checkApiFileTimeStamp android.WritablePath
	latestApiFile android.Path
	currentApiFile android.Path
	dumpedApiFile android.WritablePath
	}

	type syspropLibraryProperties struct {
	// Determine who owns this sysprop library. Possible values are
	// "Platform", "Vendor", or "Odm"
	Property_owner string

	// list of package names that will be documented and publicized as API
	Api_packages []string

	// If set to true, allow this module to be dexed and installed on devices.
	Installable *bool

	// Make this module available when building for recovery
	Recovery_available *bool

	// Make this module available when building for vendor
	Vendor_available *bool

	// list of .sysprop files which defines the properties.
	Srcs []string `android:"path"`

	// If set to true, build a variant of the module for the host. Defaults to false.
	Host_supported *bool

	// Whether public stub exists or not.
	Public_stub *bool `blueprint:"mutated"`

	Cpp struct {
	// Minimum sdk version that the artifact should support when it runs as part of mainline modules(APEX).
	// Forwarded to cc_library.min_sdk_version
	Min_sdk_version *string
	}
	}

	var (
	pctx = android.NewPackageContext("android/soong/sysprop")
	syspropCcTag = dependencyTag{name: "syspropCc"}
	)

	func init() {
	android.RegisterModuleType("sysprop_library", syspropLibraryFactory)
	}

	func (m *syspropLibrary) Name() string {
	return m.BaseModuleName() + "_sysprop_library"
	}

	func (m *syspropLibrary) Owner() string {
	return m.properties.Property_owner
	}

	func (m *syspropLibrary) CcModuleName() string {
	return "lib" + m.BaseModuleName()
	}

	func (m *syspropLibrary) JavaPublicStubName() string {
	if proptools.Bool(m.properties.Public_stub) {
	return m.BaseModuleName() + "_public"
	}
	return ""
	}

	func (m *syspropLibrary) javaGenModuleName() string {
	return m.BaseModuleName() + "_java_gen"
	}

	func (m *syspropLibrary) javaGenPublicStubName() string {
	return m.BaseModuleName() + "_java_gen_public"
	}

	func (m *syspropLibrary) BaseModuleName() string {
	return m.ModuleBase.Name()
	}

	func (m *syspropLibrary) HasPublicStub() bool {
	return proptools.Bool(m.properties.Public_stub)
	}

	func (m *syspropLibrary) GenerateAndroidBuildActions(ctx android.ModuleContext) {
	baseModuleName := m.BaseModuleName()

	for _, syspropFile := range android.PathsForModuleSrc(ctx, m.properties.Srcs) {
	if syspropFile.Ext() != ".sysprop" {
	ctx.PropertyErrorf("srcs", "srcs contains non-sysprop file %q", syspropFile.String())
	}
	}

	if ctx.Failed() {
	return
	}

	m.currentApiFile = android.PathForSource(ctx, ctx.ModuleDir(), "api", baseModuleName+"-current.txt")
	m.latestApiFile = android.PathForSource(ctx, ctx.ModuleDir(), "api", baseModuleName+"-latest.txt")

	// dump API rule
	rule := android.NewRuleBuilder()
	m.dumpedApiFile = android.PathForModuleOut(ctx, "api-dump.txt")
	rule.Command().
	BuiltTool(ctx, "sysprop_api_dump").
	Output(m.dumpedApiFile).
	Inputs(android.PathsForModuleSrc(ctx, m.properties.Srcs))
	rule.Build(pctx, ctx, baseModuleName+"_api_dump", baseModuleName+" api dump")

	// check API rule
	rule = android.NewRuleBuilder()

	// 1. current.txt <-> api_dump.txt
	msg := fmt.Sprintf(`\n******************************\n`+
	`API of sysprop_library %s doesn't match with current.txt\n`+
	`Please update current.txt by:\n`+
	`m %s-dump-api && rm -rf %q && cp -f %q %q\n`+
	`******************************\n`, baseModuleName, baseModuleName,
	m.currentApiFile.String(), m.dumpedApiFile.String(), m.currentApiFile.String())

	rule.Command().
	Text("( cmp").Flag("-s").
	Input(m.dumpedApiFile).
	Input(m.currentApiFile).
	Text("\|\| ( echo").Flag("-e").
	Flag(`"` + msg + `"`).
	Text("; exit 38) )")

	// 2. current.txt <-> latest.txt
	msg = fmt.Sprintf(`\n******************************\n`+
	`API of sysprop_library %s doesn't match with latest version\n`+
	`Please fix the breakage and rebuild.\n`+
	`******************************\n`, baseModuleName)

	rule.Command().
	Text("( ").
	BuiltTool(ctx, "sysprop_api_checker").
	Input(m.latestApiFile).
	Input(m.currentApiFile).
	Text(" \|\| ( echo").Flag("-e").
	Flag(`"` + msg + `"`).
	Text("; exit 38) )")

	m.checkApiFileTimeStamp = android.PathForModuleOut(ctx, "check_api.timestamp")

	rule.Command().
	Text("touch").
	Output(m.checkApiFileTimeStamp)

	rule.Build(pctx, ctx, baseModuleName+"_check_api", baseModuleName+" check api")
	}

	func (m *syspropLibrary) AndroidMk() android.AndroidMkData {
	return android.AndroidMkData{
	Custom: func(w io.Writer, name, prefix, moduleDir string, data android.AndroidMkData) {
	// sysprop_library module itself is defined as a FAKE module to perform API check.
	// Actual implementation libraries are created on LoadHookMutator
	fmt.Fprintln(w, "\ninclude $(CLEAR_VARS)")
	fmt.Fprintf(w, "LOCAL_MODULE := %s\n", m.Name())
	fmt.Fprintf(w, "LOCAL_MODULE_CLASS := FAKE\n")
	fmt.Fprintf(w, "LOCAL_MODULE_TAGS := optional\n")
	fmt.Fprintf(w, "include $(BUILD_SYSTEM)/base_rules.mk\n\n")
	fmt.Fprintf(w, "$(LOCAL_BUILT_MODULE): %s\n", m.checkApiFileTimeStamp.String())
	fmt.Fprintf(w, "\ttouch $@\n\n")
	fmt.Fprintf(w, ".PHONY: %s-check-api %s-dump-api\n\n", name, name)

	// dump API rule
	fmt.Fprintf(w, "%s-dump-api: %s\n\n", name, m.dumpedApiFile.String())

	// check API rule
	fmt.Fprintf(w, "%s-check-api: %s\n\n", name, m.checkApiFileTimeStamp.String())
	}}
	}

	// sysprop_library creates schematized APIs from sysprop description files (.sysprop).
	// Both Java and C++ modules can link against sysprop_library, and API stability check
	// against latest APIs (see build/soong/scripts/freeze-sysprop-api-files.sh)
	// is performed.
	func syspropLibraryFactory() android.Module {
	m := &syspropLibrary{}

	m.AddProperties(
	&m.properties,
	)
	android.InitAndroidModule(m)
	android.InitApexModule(m)
	android.AddLoadHook(m, func(ctx android.LoadHookContext) { syspropLibraryHook(ctx, m) })
	return m
	}

	type ccLibraryProperties struct {
	Name *string
	Srcs []string
	Soc_specific *bool
	Device_specific *bool
	Product_specific *bool
	Sysprop struct {
	Platform *bool
	}
	Target struct {
	Android struct {
	Header_libs []string
	Shared_libs []string
	}
	Host struct {
	Static_libs []string
	}
	}
	Required []string
	Recovery *bool
	Recovery_available *bool
	Vendor_available *bool
	Host_supported *bool
	Apex_available []string
	Min_sdk_version *string
	}

	type javaLibraryProperties struct {
	Name *string
	Srcs []string
	Soc_specific *bool
	Device_specific *bool
	Product_specific *bool
	Required []string
	Sdk_version *string
	Installable *bool
	Libs []string
	Stem *string
	}

	func syspropLibraryHook(ctx android.LoadHookContext, m *syspropLibrary) {
	if len(m.properties.Srcs) == 0 {
	ctx.PropertyErrorf("srcs", "sysprop_library must specify srcs")
	}

	missing_api := false

	for _, txt := range []string{"-current.txt", "-latest.txt"} {
	path := path.Join(ctx.ModuleDir(), "api", m.BaseModuleName()+txt)
	file := android.ExistentPathForSource(ctx, path)
	if !file.Valid() {
	ctx.ModuleErrorf("API file %#v doesn't exist", path)
	missing_api = true
	}
	}

	if missing_api {
	script := "build/soong/scripts/gen-sysprop-api-files.sh"
	p := android.ExistentPathForSource(ctx, script)

	if !p.Valid() {
	panic(fmt.Sprintf("script file %s doesn't exist", script))
	}

	ctx.ModuleErrorf("One or more api files are missing. "+
	"You can create them by:\n"+
	"%s %q %q", script, ctx.ModuleDir(), m.BaseModuleName())
	return
	}

	// ctx's Platform or Specific functions represent where this sysprop_library installed.
	installedInSystem := ctx.Platform() \|\| ctx.SystemExtSpecific()
	installedInVendorOrOdm := ctx.SocSpecific() \|\| ctx.DeviceSpecific()
	isOwnerPlatform := false
	stub := "sysprop-library-stub-"

	switch m.Owner() {
	case "Platform":
	// Every partition can access platform-defined properties
	stub += "platform"
	isOwnerPlatform = true
	case "Vendor":
	// System can't access vendor's properties
	if installedInSystem {
	ctx.ModuleErrorf("None of soc_specific, device_specific, product_specific is true. " +
	"System can't access sysprop_library owned by Vendor")
	}
	stub += "vendor"
	case "Odm":
	// Only vendor can access Odm-defined properties
	if !installedInVendorOrOdm {
	ctx.ModuleErrorf("Neither soc_speicifc nor device_specific is true. " +
	"Odm-defined properties should be accessed only in Vendor or Odm")
	}
	stub += "vendor"
	default:
	ctx.PropertyErrorf("property_owner",
	"Unknown value %s: must be one of Platform, Vendor or Odm", m.Owner())
	}

	ccProps := ccLibraryProperties{}
	ccProps.Name = proptools.StringPtr(m.CcModuleName())
	ccProps.Srcs = m.properties.Srcs
	ccProps.Soc_specific = proptools.BoolPtr(ctx.SocSpecific())
	ccProps.Device_specific = proptools.BoolPtr(ctx.DeviceSpecific())
	ccProps.Product_specific = proptools.BoolPtr(ctx.ProductSpecific())
	ccProps.Sysprop.Platform = proptools.BoolPtr(isOwnerPlatform)
	ccProps.Target.Android.Header_libs = []string{"libbase_headers"}
	ccProps.Target.Android.Shared_libs = []string{"liblog"}
	ccProps.Target.Host.Static_libs = []string{"libbase", "liblog"}
	ccProps.Recovery_available = m.properties.Recovery_available
	ccProps.Vendor_available = m.properties.Vendor_available
	ccProps.Host_supported = m.properties.Host_supported
	ccProps.Apex_available = m.ApexProperties.Apex_available
	ccProps.Min_sdk_version = m.properties.Cpp.Min_sdk_version
	ctx.CreateModule(cc.LibraryFactory, &ccProps)

	scope := "internal"

	// We need to only use public version, if the partition where sysprop_library will be installed
	// is different from owner.

	if ctx.ProductSpecific() {
	// Currently product partition can't own any sysprop_library.
	scope = "public"
	} else if isOwnerPlatform && installedInVendorOrOdm {
	// Vendor or Odm should use public version of Platform's sysprop_library.
	scope = "public"
	}

	ctx.CreateModule(syspropJavaGenFactory, &syspropGenProperties{
	Srcs: m.properties.Srcs,
	Scope: scope,
	Name: proptools.StringPtr(m.javaGenModuleName()),
	})

	ctx.CreateModule(java.LibraryFactory, &javaLibraryProperties{
	Name: proptools.StringPtr(m.BaseModuleName()),
	Srcs: []string{":" + m.javaGenModuleName()},
	Soc_specific: proptools.BoolPtr(ctx.SocSpecific()),
	Device_specific: proptools.BoolPtr(ctx.DeviceSpecific()),
	Product_specific: proptools.BoolPtr(ctx.ProductSpecific()),
	Installable: m.properties.Installable,
	Sdk_version: proptools.StringPtr("core_current"),
	Libs: []string{stub},
	})

	// if platform sysprop_library is installed in /system or /system-ext, we regard it as an API
	// and allow any modules (even from different partition) to link against the sysprop_library.
	// To do that, we create a public stub and expose it to modules with sdk_version: system_*.
	if isOwnerPlatform && installedInSystem {
	m.properties.Public_stub = proptools.BoolPtr(true)
	ctx.CreateModule(syspropJavaGenFactory, &syspropGenProperties{
	Srcs: m.properties.Srcs,
	Scope: "public",
	Name: proptools.StringPtr(m.javaGenPublicStubName()),
	})

	ctx.CreateModule(java.LibraryFactory, &javaLibraryProperties{
	Name: proptools.StringPtr(m.JavaPublicStubName()),
	Srcs: []string{":" + m.javaGenPublicStubName()},
	Installable: proptools.BoolPtr(false),
	Sdk_version: proptools.StringPtr("core_current"),
	Libs: []string{stub},
	Stem: proptools.StringPtr(m.BaseModuleName()),
	})
	}
	}

	func syspropDepsMutator(ctx android.BottomUpMutatorContext) {
	if m, ok := ctx.Module().(*syspropLibrary); ok {
	ctx.AddReverseDependency(m, nil, m.javaGenModuleName())

	if proptools.Bool(m.properties.Public_stub) {
	ctx.AddReverseDependency(m, nil, m.javaGenPublicStubName())
	}
	}
	}