platform_build_soong/android/module.go

// Copyright 2015 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 android

import (
	"fmt"
	"path/filepath"
	"sort"
	"strings"
	"text/scanner"

	"github.com/google/blueprint"
	"github.com/google/blueprint/pathtools"
)

var (
	DeviceSharedLibrary = "shared_library"
	DeviceStaticLibrary = "static_library"
	DeviceExecutable    = "executable"
	HostSharedLibrary   = "host_shared_library"
	HostStaticLibrary   = "host_static_library"
	HostExecutable      = "host_executable"
)

type BuildParams struct {
	Rule            blueprint.Rule
	Deps            blueprint.Deps
	Depfile         WritablePath
	Description     string
	Output          WritablePath
	Outputs         WritablePaths
	ImplicitOutput  WritablePath
	ImplicitOutputs WritablePaths
	Input           Path
	Inputs          Paths
	Implicit        Path
	Implicits       Paths
	OrderOnly       Paths
	Default         bool
	Args            map[string]string
}

type ModuleBuildParams BuildParams

type androidBaseContext interface {
	Target() Target
	TargetPrimary() bool
	Arch() Arch
	Os() OsType
	Host() bool
	Device() bool
	Darwin() bool
	Windows() bool
	Debug() bool
	PrimaryArch() bool
	Platform() bool
	DeviceSpecific() bool
	SocSpecific() bool
	ProductSpecific() bool
	AConfig() Config
	DeviceConfig() DeviceConfig
}

type BaseContext interface {
	BaseModuleContext
	androidBaseContext
}

// BaseModuleContext is the same as blueprint.BaseModuleContext except that Config() returns
// a Config instead of an interface{}.
type BaseModuleContext interface {
	ModuleName() string
	ModuleDir() string
	Config() Config

	ContainsProperty(name string) bool
	Errorf(pos scanner.Position, fmt string, args ...interface{})
	ModuleErrorf(fmt string, args ...interface{})
	PropertyErrorf(property, fmt string, args ...interface{})
	Failed() bool

	// GlobWithDeps returns a list of files that match the specified pattern but do not match any
	// of the patterns in excludes.  It also adds efficient dependencies to rerun the primary
	// builder whenever a file matching the pattern as added or removed, without rerunning if a
	// file that does not match the pattern is added to a searched directory.
	GlobWithDeps(pattern string, excludes []string) ([]string, error)

	Fs() pathtools.FileSystem
	AddNinjaFileDeps(deps ...string)
}

type ModuleContext interface {
	androidBaseContext
	BaseModuleContext

	// Deprecated: use ModuleContext.Build instead.
	ModuleBuild(pctx PackageContext, params ModuleBuildParams)

	ExpandSources(srcFiles, excludes []string) Paths
	ExpandSource(srcFile, prop string) Path
	ExpandOptionalSource(srcFile *string, prop string) OptionalPath
	ExpandSourcesSubDir(srcFiles, excludes []string, subDir string) Paths
	Glob(globPattern string, excludes []string) Paths
	GlobFiles(globPattern string, excludes []string) Paths

	InstallExecutable(installPath OutputPath, name string, srcPath Path, deps ...Path) OutputPath
	InstallFile(installPath OutputPath, name string, srcPath Path, deps ...Path) OutputPath
	InstallSymlink(installPath OutputPath, name string, srcPath OutputPath) OutputPath
	CheckbuildFile(srcPath Path)

	AddMissingDependencies(deps []string)

	InstallInData() bool
	InstallInSanitizerDir() bool

	RequiredModuleNames() []string

	// android.ModuleContext methods
	// These are duplicated instead of embedded so that can eventually be wrapped to take an
	// android.Module instead of a blueprint.Module
	OtherModuleName(m blueprint.Module) string
	OtherModuleErrorf(m blueprint.Module, fmt string, args ...interface{})
	OtherModuleDependencyTag(m blueprint.Module) blueprint.DependencyTag

	GetDirectDepWithTag(name string, tag blueprint.DependencyTag) blueprint.Module
	GetDirectDep(name string) (blueprint.Module, blueprint.DependencyTag)

	ModuleSubDir() string

	VisitDirectDepsBlueprint(visit func(blueprint.Module))
	VisitDirectDeps(visit func(Module))
	VisitDirectDepsWithTag(tag blueprint.DependencyTag, visit func(Module))
	VisitDirectDepsIf(pred func(Module) bool, visit func(Module))
	VisitDepsDepthFirst(visit func(Module))
	VisitDepsDepthFirstIf(pred func(Module) bool, visit func(Module))
	WalkDeps(visit func(Module, Module) bool)

	Variable(pctx PackageContext, name, value string)
	Rule(pctx PackageContext, name string, params blueprint.RuleParams, argNames ...string) blueprint.Rule
	// Similar to blueprint.ModuleContext.Build, but takes Paths instead of []string,
	// and performs more verification.
	Build(pctx PackageContext, params BuildParams)

	PrimaryModule() Module
	FinalModule() Module
	VisitAllModuleVariants(visit func(Module))

	GetMissingDependencies() []string
	Namespace() blueprint.Namespace
}

type Module interface {
	blueprint.Module

	// GenerateAndroidBuildActions is analogous to Blueprints' GenerateBuildActions,
	// but GenerateAndroidBuildActions also has access to Android-specific information.
	// For more information, see Module.GenerateBuildActions within Blueprint's module_ctx.go
	GenerateAndroidBuildActions(ModuleContext)

	DepsMutator(BottomUpMutatorContext)

	base() *ModuleBase
	Enabled() bool
	Target() Target
	InstallInData() bool
	InstallInSanitizerDir() bool
	SkipInstall()
	ExportedToMake() bool

	AddProperties(props ...interface{})
	GetProperties() []interface{}

	BuildParamsForTests() []BuildParams
}

type nameProperties struct {
	// The name of the module.  Must be unique across all modules.
	Name *string
}

type commonProperties struct {
	Tags []string

	// emit build rules for this module
	Enabled *bool `android:"arch_variant"`

	// control whether this module compiles for 32-bit, 64-bit, or both.  Possible values
	// are "32" (compile for 32-bit only), "64" (compile for 64-bit only), "both" (compile for both
	// architectures), or "first" (compile for 64-bit on a 64-bit platform, and 32-bit on a 32-bit
	// platform
	Compile_multilib *string `android:"arch_variant"`

	Target struct {
		Host struct {
			Compile_multilib *string
		}
		Android struct {
			Compile_multilib *string
		}
	}

	Default_multilib string `blueprint:"mutated"`

	// whether this is a proprietary vendor module, and should be installed into /vendor
	Proprietary *bool

	// vendor who owns this module
	Owner *string

	// whether this module is specific to an SoC (System-On-a-Chip). When set to true,
	// it is installed into /vendor (or /system/vendor if vendor partition does not exist).
	// Use `soc_specific` instead for better meaning.
	Vendor *bool

	// whether this module is specific to an SoC (System-On-a-Chip). When set to true,
	// it is installed into /vendor (or /system/vendor if vendor partition does not exist).
	Soc_specific *bool

	// whether this module is specific to a device, not only for SoC, but also for off-chip
	// peripherals. When set to true, it is installed into /odm (or /vendor/odm if odm partition
	// does not exist, or /system/vendor/odm if both odm and vendor partitions do not exist).
	// This implies `soc_specific:true`.
	Device_specific *bool

	// whether this module is specific to a software configuration of a product (e.g. country,
	// network operator, etc). When set to true, it is installed into /product (or
	// /system/product if product partition does not exist).
	Product_specific *bool

	// init.rc files to be installed if this module is installed
	Init_rc []string

	// names of other modules to install if this module is installed
	Required []string `android:"arch_variant"`

	// relative path to a file to include in the list of notices for the device
	Notice *string

	// Set by TargetMutator
	CompileTarget  Target `blueprint:"mutated"`
	CompilePrimary bool   `blueprint:"mutated"`

	// Set by InitAndroidModule
	HostOrDeviceSupported HostOrDeviceSupported `blueprint:"mutated"`
	ArchSpecific          bool                  `blueprint:"mutated"`

	SkipInstall bool `blueprint:"mutated"`

	NamespaceExportedToMake bool `blueprint:"mutated"`
}

type hostAndDeviceProperties struct {
	Host_supported   *bool
	Device_supported *bool
}

type Multilib string

const (
	MultilibBoth        Multilib = "both"
	MultilibFirst       Multilib = "first"
	MultilibCommon      Multilib = "common"
	MultilibCommonFirst Multilib = "common_first"
	MultilibDefault     Multilib = ""
)

type HostOrDeviceSupported int

const (
	_ HostOrDeviceSupported = iota
	HostSupported
	HostSupportedNoCross
	DeviceSupported
	HostAndDeviceSupported
	HostAndDeviceDefault
	NeitherHostNorDeviceSupported
)

type moduleKind int

const (
	platformModule moduleKind = iota
	deviceSpecificModule
	socSpecificModule
	productSpecificModule
)

func (k moduleKind) String() string {
	switch k {
	case platformModule:
		return "platform"
	case deviceSpecificModule:
		return "device-specific"
	case socSpecificModule:
		return "soc-specific"
	case productSpecificModule:
		return "product-specific"
	default:
		panic(fmt.Errorf("unknown module kind %d", k))
	}
}

func InitAndroidModule(m Module) {
	base := m.base()
	base.module = m

	m.AddProperties(
		&base.nameProperties,
		&base.commonProperties,
		&base.variableProperties)
}

func InitAndroidArchModule(m Module, hod HostOrDeviceSupported, defaultMultilib Multilib) {
	InitAndroidModule(m)

	base := m.base()
	base.commonProperties.HostOrDeviceSupported = hod
	base.commonProperties.Default_multilib = string(defaultMultilib)
	base.commonProperties.ArchSpecific = true

	switch hod {
	case HostAndDeviceSupported, HostAndDeviceDefault:
		m.AddProperties(&base.hostAndDeviceProperties)
	}

	InitArchModule(m)
}

// A ModuleBase object contains the properties that are common to all Android
// modules.  It should be included as an anonymous field in every module
// struct definition.  InitAndroidModule should then be called from the module's
// factory function, and the return values from InitAndroidModule should be
// returned from the factory function.
//
// The ModuleBase type is responsible for implementing the GenerateBuildActions
// method to support the blueprint.Module interface. This method will then call
// the module's GenerateAndroidBuildActions method once for each build variant
// that is to be built. GenerateAndroidBuildActions is passed a
// AndroidModuleContext rather than the usual blueprint.ModuleContext.
// AndroidModuleContext exposes extra functionality specific to the Android build
// system including details about the particular build variant that is to be
// generated.
//
// For example:
//
//     import (
//         "android/soong/android"
//     )
//
//     type myModule struct {
//         android.ModuleBase
//         properties struct {
//             MyProperty string
//         }
//     }
//
//     func NewMyModule() android.Module) {
//         m := &myModule{}
//         m.AddProperties(&m.properties)
//         android.InitAndroidModule(m)
//         return m
//     }
//
//     func (m *myModule) GenerateAndroidBuildActions(ctx android.ModuleContext) {
//         // Get the CPU architecture for the current build variant.
//         variantArch := ctx.Arch()
//
//         // ...
//     }
type ModuleBase struct {
	// Putting the curiously recurring thing pointing to the thing that contains
	// the thing pattern to good use.
	// TODO: remove this
	module Module

	nameProperties          nameProperties
	commonProperties        commonProperties
	variableProperties      variableProperties
	hostAndDeviceProperties hostAndDeviceProperties
	generalProperties       []interface{}
	archProperties          []interface{}
	customizableProperties  []interface{}

	noAddressSanitizer bool
	installFiles       Paths
	checkbuildFiles    Paths

	// Used by buildTargetSingleton to create checkbuild and per-directory build targets
	// Only set on the final variant of each module
	installTarget    WritablePath
	checkbuildTarget WritablePath
	blueprintDir     string

	hooks hooks

	registerProps []interface{}

	// For tests
	buildParams []BuildParams
}

func (a *ModuleBase) AddProperties(props ...interface{}) {
	a.registerProps = append(a.registerProps, props...)
}

func (a *ModuleBase) GetProperties() []interface{} {
	return a.registerProps
}

func (a *ModuleBase) BuildParamsForTests() []BuildParams {
	return a.buildParams
}

// Name returns the name of the module.  It may be overridden by individual module types, for
// example prebuilts will prepend prebuilt_ to the name.
func (a *ModuleBase) Name() string {
	return String(a.nameProperties.Name)
}

// BaseModuleName returns the name of the module as specified in the blueprints file.
func (a *ModuleBase) BaseModuleName() string {
	return String(a.nameProperties.Name)
}

func (a *ModuleBase) base() *ModuleBase {
	return a
}

func (a *ModuleBase) SetTarget(target Target, primary bool) {
	a.commonProperties.CompileTarget = target
	a.commonProperties.CompilePrimary = primary
}

func (a *ModuleBase) Target() Target {
	return a.commonProperties.CompileTarget
}

func (a *ModuleBase) TargetPrimary() bool {
	return a.commonProperties.CompilePrimary
}

func (a *ModuleBase) Os() OsType {
	return a.Target().Os
}

func (a *ModuleBase) Host() bool {
	return a.Os().Class == Host || a.Os().Class == HostCross
}

func (a *ModuleBase) Arch() Arch {
	return a.Target().Arch
}

func (a *ModuleBase) ArchSpecific() bool {
	return a.commonProperties.ArchSpecific
}

func (a *ModuleBase) OsClassSupported() []OsClass {
	switch a.commonProperties.HostOrDeviceSupported {
	case HostSupported:
		return []OsClass{Host, HostCross}
	case HostSupportedNoCross:
		return []OsClass{Host}
	case DeviceSupported:
		return []OsClass{Device}
	case HostAndDeviceSupported:
		var supported []OsClass
		if Bool(a.hostAndDeviceProperties.Host_supported) {
			supported = append(supported, Host, HostCross)
		}
		if a.hostAndDeviceProperties.Device_supported == nil ||
			*a.hostAndDeviceProperties.Device_supported {
			supported = append(supported, Device)
		}
		return supported
	default:
		return nil
	}
}

func (a *ModuleBase) DeviceSupported() bool {
	return a.commonProperties.HostOrDeviceSupported == DeviceSupported ||
		a.commonProperties.HostOrDeviceSupported == HostAndDeviceSupported &&
			(a.hostAndDeviceProperties.Device_supported == nil ||
				*a.hostAndDeviceProperties.Device_supported)
}

func (a *ModuleBase) Enabled() bool {
	if a.commonProperties.Enabled == nil {
		return !a.Os().DefaultDisabled
	}
	return *a.commonProperties.Enabled
}

func (a *ModuleBase) SkipInstall() {
	a.commonProperties.SkipInstall = true
}

func (a *ModuleBase) ExportedToMake() bool {
	return a.commonProperties.NamespaceExportedToMake
}

func (a *ModuleBase) computeInstallDeps(
	ctx blueprint.ModuleContext) Paths {

	result := Paths{}
	ctx.VisitDepsDepthFirstIf(isFileInstaller,
		func(m blueprint.Module) {
			fileInstaller := m.(fileInstaller)
			files := fileInstaller.filesToInstall()
			result = append(result, files...)
		})

	return result
}

func (a *ModuleBase) filesToInstall() Paths {
	return a.installFiles
}

func (p *ModuleBase) NoAddressSanitizer() bool {
	return p.noAddressSanitizer
}

func (p *ModuleBase) InstallInData() bool {
	return false
}

func (p *ModuleBase) InstallInSanitizerDir() bool {
	return false
}

func (a *ModuleBase) generateModuleTarget(ctx ModuleContext) {
	allInstalledFiles := Paths{}
	allCheckbuildFiles := Paths{}
	ctx.VisitAllModuleVariants(func(module Module) {
		a := module.base()
		allInstalledFiles = append(allInstalledFiles, a.installFiles...)
		allCheckbuildFiles = append(allCheckbuildFiles, a.checkbuildFiles...)
	})

	var deps Paths

	namespacePrefix := ctx.Namespace().(*Namespace).id
	if namespacePrefix != "" {
		namespacePrefix = namespacePrefix + "-"
	}

	if len(allInstalledFiles) > 0 {
		name := PathForPhony(ctx, namespacePrefix+ctx.ModuleName()+"-install")
		ctx.Build(pctx, BuildParams{
			Rule:      blueprint.Phony,
			Output:    name,
			Implicits: allInstalledFiles,
			Default:   !ctx.Config().EmbeddedInMake(),
		})
		deps = append(deps, name)
		a.installTarget = name
	}

	if len(allCheckbuildFiles) > 0 {
		name := PathForPhony(ctx, namespacePrefix+ctx.ModuleName()+"-checkbuild")
		ctx.Build(pctx, BuildParams{
			Rule:      blueprint.Phony,
			Output:    name,
			Implicits: allCheckbuildFiles,
		})
		deps = append(deps, name)
		a.checkbuildTarget = name
	}

	if len(deps) > 0 {
		suffix := ""
		if ctx.Config().EmbeddedInMake() {
			suffix = "-soong"
		}

		name := PathForPhony(ctx, namespacePrefix+ctx.ModuleName()+suffix)
		ctx.Build(pctx, BuildParams{
			Rule:      blueprint.Phony,
			Outputs:   []WritablePath{name},
			Implicits: deps,
		})

		a.blueprintDir = ctx.ModuleDir()
	}
}

func determineModuleKind(a *ModuleBase, ctx blueprint.BaseModuleContext) moduleKind {
	var socSpecific = Bool(a.commonProperties.Vendor) || Bool(a.commonProperties.Proprietary) || Bool(a.commonProperties.Soc_specific)
	var deviceSpecific = Bool(a.commonProperties.Device_specific)
	var productSpecific = Bool(a.commonProperties.Product_specific)

	if ((socSpecific || deviceSpecific) && productSpecific) || (socSpecific && deviceSpecific) {
		msg := "conflicting value set here"
		if productSpecific {
			ctx.PropertyErrorf("product_specific", "a module cannot be specific to SoC or device and product at the same time.")
			if deviceSpecific {
				ctx.PropertyErrorf("device_specific", msg)
			}
		} else {
			ctx.PropertyErrorf("device_specific", "a module cannot be specific to SoC and device at the same time.")
		}
		if Bool(a.commonProperties.Vendor) {
			ctx.PropertyErrorf("vendor", msg)
		}
		if Bool(a.commonProperties.Proprietary) {
			ctx.PropertyErrorf("proprietary", msg)
		}
		if Bool(a.commonProperties.Soc_specific) {
			ctx.PropertyErrorf("soc_specific", msg)
		}
	}

	if productSpecific {
		return productSpecificModule
	} else if deviceSpecific {
		return deviceSpecificModule
	} else if socSpecific {
		return socSpecificModule
	} else {
		return platformModule
	}
}

func (a *ModuleBase) androidBaseContextFactory(ctx blueprint.BaseModuleContext) androidBaseContextImpl {
	return androidBaseContextImpl{
		target:        a.commonProperties.CompileTarget,
		targetPrimary: a.commonProperties.CompilePrimary,
		kind:          determineModuleKind(a, ctx),
		config:        ctx.Config().(Config),
	}
}

func (a *ModuleBase) GenerateBuildActions(blueprintCtx blueprint.ModuleContext) {
	ctx := &androidModuleContext{
		module:                 a.module,
		ModuleContext:          blueprintCtx,
		androidBaseContextImpl: a.androidBaseContextFactory(blueprintCtx),
		installDeps:            a.computeInstallDeps(blueprintCtx),
		installFiles:           a.installFiles,
		missingDeps:            blueprintCtx.GetMissingDependencies(),
	}

	desc := "//" + ctx.ModuleDir() + ":" + ctx.ModuleName() + " "
	var suffix []string
	if ctx.Os().Class != Device && ctx.Os().Class != Generic {
		suffix = append(suffix, ctx.Os().String())
	}
	if !ctx.PrimaryArch() {
		suffix = append(suffix, ctx.Arch().ArchType.String())
	}

	ctx.Variable(pctx, "moduleDesc", desc)

	s := ""
	if len(suffix) > 0 {
		s = " [" + strings.Join(suffix, " ") + "]"
	}
	ctx.Variable(pctx, "moduleDescSuffix", s)

	if a.Enabled() {
		a.module.GenerateAndroidBuildActions(ctx)
		if ctx.Failed() {
			return
		}

		a.installFiles = append(a.installFiles, ctx.installFiles...)
		a.checkbuildFiles = append(a.checkbuildFiles, ctx.checkbuildFiles...)
	}

	if a == ctx.FinalModule().(Module).base() {
		a.generateModuleTarget(ctx)
		if ctx.Failed() {
			return
		}
	}

	a.buildParams = ctx.buildParams
}

type androidBaseContextImpl struct {
	target        Target
	targetPrimary bool
	debug         bool
	kind          moduleKind
	config        Config
}

type androidModuleContext struct {
	blueprint.ModuleContext
	androidBaseContextImpl
	installDeps     Paths
	installFiles    Paths
	checkbuildFiles Paths
	missingDeps     []string
	module          Module

	// For tests
	buildParams []BuildParams
}

func (a *androidModuleContext) ninjaError(desc string, outputs []string, err error) {
	a.ModuleContext.Build(pctx.PackageContext, blueprint.BuildParams{
		Rule:        ErrorRule,
		Description: desc,
		Outputs:     outputs,
		Optional:    true,
		Args: map[string]string{
			"error": err.Error(),
		},
	})
	return
}

func (a *androidModuleContext) Config() Config {
	return a.ModuleContext.Config().(Config)
}

func (a *androidModuleContext) ModuleBuild(pctx PackageContext, params ModuleBuildParams) {
	a.Build(pctx, BuildParams(params))
}

func convertBuildParams(params BuildParams) blueprint.BuildParams {
	bparams := blueprint.BuildParams{
		Rule:            params.Rule,
		Description:     params.Description,
		Deps:            params.Deps,
		Outputs:         params.Outputs.Strings(),
		ImplicitOutputs: params.ImplicitOutputs.Strings(),
		Inputs:          params.Inputs.Strings(),
		Implicits:       params.Implicits.Strings(),
		OrderOnly:       params.OrderOnly.Strings(),
		Args:            params.Args,
		Optional:        !params.Default,
	}

	if params.Depfile != nil {
		bparams.Depfile = params.Depfile.String()
	}
	if params.Output != nil {
		bparams.Outputs = append(bparams.Outputs, params.Output.String())
	}
	if params.ImplicitOutput != nil {
		bparams.ImplicitOutputs = append(bparams.ImplicitOutputs, params.ImplicitOutput.String())
	}
	if params.Input != nil {
		bparams.Inputs = append(bparams.Inputs, params.Input.String())
	}
	if params.Implicit != nil {
		bparams.Implicits = append(bparams.Implicits, params.Implicit.String())
	}

	return bparams
}

func (a *androidModuleContext) Variable(pctx PackageContext, name, value string) {
	a.ModuleContext.Variable(pctx.PackageContext, name, value)
}

func (a *androidModuleContext) Rule(pctx PackageContext, name string, params blueprint.RuleParams,
	argNames ...string) blueprint.Rule {

	return a.ModuleContext.Rule(pctx.PackageContext, name, params, argNames...)
}

func (a *androidModuleContext) Build(pctx PackageContext, params BuildParams) {
	if a.config.captureBuild {
		a.buildParams = append(a.buildParams, params)
	}

	bparams := convertBuildParams(params)

	if bparams.Description != "" {
		bparams.Description = "${moduleDesc}" + params.Description + "${moduleDescSuffix}"
	}

	if a.missingDeps != nil {
		a.ninjaError(bparams.Description, bparams.Outputs,
			fmt.Errorf("module %s missing dependencies: %s\n",
				a.ModuleName(), strings.Join(a.missingDeps, ", ")))
		return
	}

	a.ModuleContext.Build(pctx.PackageContext, bparams)
}

func (a *androidModuleContext) GetMissingDependencies() []string {
	return a.missingDeps
}

func (a *androidModuleContext) AddMissingDependencies(deps []string) {
	if deps != nil {
		a.missingDeps = append(a.missingDeps, deps...)
		a.missingDeps = FirstUniqueStrings(a.missingDeps)
	}
}

func (a *androidModuleContext) validateAndroidModule(module blueprint.Module) Module {
	aModule, _ := module.(Module)
	if aModule == nil {
		a.ModuleErrorf("module %q not an android module", a.OtherModuleName(aModule))
		return nil
	}

	if !aModule.Enabled() {
		if a.Config().AllowMissingDependencies() {
			a.AddMissingDependencies([]string{a.OtherModuleName(aModule)})
		} else {
			a.ModuleErrorf("depends on disabled module %q", a.OtherModuleName(aModule))
		}
		return nil
	}

	return aModule
}

func (a *androidModuleContext) VisitDirectDepsBlueprint(visit func(blueprint.Module)) {
	a.ModuleContext.VisitDirectDeps(visit)
}

func (a *androidModuleContext) VisitDirectDeps(visit func(Module)) {
	a.ModuleContext.VisitDirectDeps(func(module blueprint.Module) {
		if aModule := a.validateAndroidModule(module); aModule != nil {
			visit(aModule)
		}
	})
}

func (a *androidModuleContext) VisitDirectDepsWithTag(tag blueprint.DependencyTag, visit func(Module)) {
	a.ModuleContext.VisitDirectDeps(func(module blueprint.Module) {
		if aModule := a.validateAndroidModule(module); aModule != nil {
			if a.ModuleContext.OtherModuleDependencyTag(aModule) == tag {
				visit(aModule)
			}
		}
	})
}

func (a *androidModuleContext) VisitDirectDepsIf(pred func(Module) bool, visit func(Module)) {
	a.ModuleContext.VisitDirectDepsIf(
		// pred
		func(module blueprint.Module) bool {
			if aModule := a.validateAndroidModule(module); aModule != nil {
				return pred(aModule)
			} else {
				return false
			}
		},
		// visit
		func(module blueprint.Module) {
			visit(module.(Module))
		})
}

func (a *androidModuleContext) VisitDepsDepthFirst(visit func(Module)) {
	a.ModuleContext.VisitDepsDepthFirst(func(module blueprint.Module) {
		if aModule := a.validateAndroidModule(module); aModule != nil {
			visit(aModule)
		}
	})
}

func (a *androidModuleContext) VisitDepsDepthFirstIf(pred func(Module) bool, visit func(Module)) {
	a.ModuleContext.VisitDepsDepthFirstIf(
		// pred
		func(module blueprint.Module) bool {
			if aModule := a.validateAndroidModule(module); aModule != nil {
				return pred(aModule)
			} else {
				return false
			}
		},
		// visit
		func(module blueprint.Module) {
			visit(module.(Module))
		})
}

func (a *androidModuleContext) WalkDeps(visit func(Module, Module) bool) {
	a.ModuleContext.WalkDeps(func(child, parent blueprint.Module) bool {
		childAndroidModule := a.validateAndroidModule(child)
		parentAndroidModule := a.validateAndroidModule(parent)
		if childAndroidModule != nil && parentAndroidModule != nil {
			return visit(childAndroidModule, parentAndroidModule)
		} else {
			return false
		}
	})
}

func (a *androidModuleContext) VisitAllModuleVariants(visit func(Module)) {
	a.ModuleContext.VisitAllModuleVariants(func(module blueprint.Module) {
		visit(module.(Module))
	})
}

func (a *androidModuleContext) PrimaryModule() Module {
	return a.ModuleContext.PrimaryModule().(Module)
}

func (a *androidModuleContext) FinalModule() Module {
	return a.ModuleContext.FinalModule().(Module)
}

func (a *androidBaseContextImpl) Target() Target {
	return a.target
}

func (a *androidBaseContextImpl) TargetPrimary() bool {
	return a.targetPrimary
}

func (a *androidBaseContextImpl) Arch() Arch {
	return a.target.Arch
}

func (a *androidBaseContextImpl) Os() OsType {
	return a.target.Os
}

func (a *androidBaseContextImpl) Host() bool {
	return a.target.Os.Class == Host || a.target.Os.Class == HostCross
}

func (a *androidBaseContextImpl) Device() bool {
	return a.target.Os.Class == Device
}

func (a *androidBaseContextImpl) Darwin() bool {
	return a.target.Os == Darwin
}

func (a *androidBaseContextImpl) Windows() bool {
	return a.target.Os == Windows
}

func (a *androidBaseContextImpl) Debug() bool {
	return a.debug
}

func (a *androidBaseContextImpl) PrimaryArch() bool {
	if len(a.config.Targets[a.target.Os.Class]) <= 1 {
		return true
	}
	return a.target.Arch.ArchType == a.config.Targets[a.target.Os.Class][0].Arch.ArchType
}

func (a *androidBaseContextImpl) AConfig() Config {
	return a.config
}

func (a *androidBaseContextImpl) DeviceConfig() DeviceConfig {
	return DeviceConfig{a.config.deviceConfig}
}

func (a *androidBaseContextImpl) Platform() bool {
	return a.kind == platformModule
}

func (a *androidBaseContextImpl) DeviceSpecific() bool {
	return a.kind == deviceSpecificModule
}

func (a *androidBaseContextImpl) SocSpecific() bool {
	return a.kind == socSpecificModule
}

func (a *androidBaseContextImpl) ProductSpecific() bool {
	return a.kind == productSpecificModule
}

func (a *androidModuleContext) InstallInData() bool {
	return a.module.InstallInData()
}

func (a *androidModuleContext) InstallInSanitizerDir() bool {
	return a.module.InstallInSanitizerDir()
}

func (a *androidModuleContext) skipInstall(fullInstallPath OutputPath) bool {
	if a.module.base().commonProperties.SkipInstall {
		return true
	}

	if a.Device() {
		if a.Config().SkipDeviceInstall() {
			return true
		}

		if a.Config().SkipMegaDeviceInstall(fullInstallPath.String()) {
			return true
		}
	}

	return false
}

func (a *androidModuleContext) InstallFile(installPath OutputPath, name string, srcPath Path,
	deps ...Path) OutputPath {
	return a.installFile(installPath, name, srcPath, Cp, deps)
}

func (a *androidModuleContext) InstallExecutable(installPath OutputPath, name string, srcPath Path,
	deps ...Path) OutputPath {
	return a.installFile(installPath, name, srcPath, CpExecutable, deps)
}

func (a *androidModuleContext) installFile(installPath OutputPath, name string, srcPath Path,
	rule blueprint.Rule, deps []Path) OutputPath {

	fullInstallPath := installPath.Join(a, name)
	a.module.base().hooks.runInstallHooks(a, fullInstallPath, false)

	if !a.skipInstall(fullInstallPath) {

		deps = append(deps, a.installDeps...)

		var implicitDeps, orderOnlyDeps Paths

		if a.Host() {
			// Installed host modules might be used during the build, depend directly on their
			// dependencies so their timestamp is updated whenever their dependency is updated
			implicitDeps = deps
		} else {
			orderOnlyDeps = deps
		}

		a.Build(pctx, BuildParams{
			Rule:        rule,
			Description: "install " + fullInstallPath.Base(),
			Output:      fullInstallPath,
			Input:       srcPath,
			Implicits:   implicitDeps,
			OrderOnly:   orderOnlyDeps,
			Default:     !a.Config().EmbeddedInMake(),
		})

		a.installFiles = append(a.installFiles, fullInstallPath)
	}
	a.checkbuildFiles = append(a.checkbuildFiles, srcPath)
	return fullInstallPath
}

func (a *androidModuleContext) InstallSymlink(installPath OutputPath, name string, srcPath OutputPath) OutputPath {
	fullInstallPath := installPath.Join(a, name)
	a.module.base().hooks.runInstallHooks(a, fullInstallPath, true)

	if !a.skipInstall(fullInstallPath) {

		a.Build(pctx, BuildParams{
			Rule:        Symlink,
			Description: "install symlink " + fullInstallPath.Base(),
			Output:      fullInstallPath,
			OrderOnly:   Paths{srcPath},
			Default:     !a.Config().EmbeddedInMake(),
			Args: map[string]string{
				"fromPath": srcPath.String(),
			},
		})

		a.installFiles = append(a.installFiles, fullInstallPath)
		a.checkbuildFiles = append(a.checkbuildFiles, srcPath)
	}
	return fullInstallPath
}

func (a *androidModuleContext) CheckbuildFile(srcPath Path) {
	a.checkbuildFiles = append(a.checkbuildFiles, srcPath)
}

type fileInstaller interface {
	filesToInstall() Paths
}

func isFileInstaller(m blueprint.Module) bool {
	_, ok := m.(fileInstaller)
	return ok
}

func isAndroidModule(m blueprint.Module) bool {
	_, ok := m.(Module)
	return ok
}

func findStringInSlice(str string, slice []string) int {
	for i, s := range slice {
		if s == str {
			return i
		}
	}
	return -1
}

func SrcIsModule(s string) string {
	if len(s) > 1 && s[0] == ':' {
		return s[1:]
	}
	return ""
}

type sourceDependencyTag struct {
	blueprint.BaseDependencyTag
}

var SourceDepTag sourceDependencyTag

// Adds necessary dependencies to satisfy filegroup or generated sources modules listed in srcFiles
// using ":module" syntax, if any.
func ExtractSourcesDeps(ctx BottomUpMutatorContext, srcFiles []string) {
	var deps []string
	set := make(map[string]bool)

	for _, s := range srcFiles {
		if m := SrcIsModule(s); m != "" {
			if _, found := set[m]; found {
				ctx.ModuleErrorf("found source dependency duplicate: %q!", m)
			} else {
				set[m] = true
				deps = append(deps, m)
			}
		}
	}

	ctx.AddDependency(ctx.Module(), SourceDepTag, deps...)
}

// Adds necessary dependencies to satisfy filegroup or generated sources modules specified in s
// using ":module" syntax, if any.
func ExtractSourceDeps(ctx BottomUpMutatorContext, s *string) {
	if s != nil {
		if m := SrcIsModule(*s); m != "" {
			ctx.AddDependency(ctx.Module(), SourceDepTag, m)
		}
	}
}

type SourceFileProducer interface {
	Srcs() Paths
}

// Returns a list of paths expanded from globs and modules referenced using ":module" syntax.
// ExtractSourcesDeps must have already been called during the dependency resolution phase.
func (ctx *androidModuleContext) ExpandSources(srcFiles, excludes []string) Paths {
	return ctx.ExpandSourcesSubDir(srcFiles, excludes, "")
}

// Returns a single path expanded from globs and modules referenced using ":module" syntax.
// ExtractSourceDeps must have already been called during the dependency resolution phase.
func (ctx *androidModuleContext) ExpandSource(srcFile, prop string) Path {
	srcFiles := ctx.ExpandSourcesSubDir([]string{srcFile}, nil, "")
	if len(srcFiles) == 1 {
		return srcFiles[0]
	} else {
		ctx.PropertyErrorf(prop, "module providing %s must produce exactly one file", prop)
		return nil
	}
}

// Returns an optional single path expanded from globs and modules referenced using ":module" syntax if
// the srcFile is non-nil.
// ExtractSourceDeps must have already been called during the dependency resolution phase.
func (ctx *androidModuleContext) ExpandOptionalSource(srcFile *string, prop string) OptionalPath {
	if srcFile != nil {
		return OptionalPathForPath(ctx.ExpandSource(*srcFile, prop))
	}
	return OptionalPath{}
}

func (ctx *androidModuleContext) ExpandSourcesSubDir(srcFiles, excludes []string, subDir string) Paths {
	prefix := PathForModuleSrc(ctx).String()

	var expandedExcludes []string
	if excludes != nil {
		expandedExcludes = make([]string, 0, len(excludes))
	}

	for _, e := range excludes {
		if m := SrcIsModule(e); m != "" {
			module := ctx.GetDirectDepWithTag(m, SourceDepTag)
			if module == nil {
				// Error will have been handled by ExtractSourcesDeps
				continue
			}
			if srcProducer, ok := module.(SourceFileProducer); ok {
				expandedExcludes = append(expandedExcludes, srcProducer.Srcs().Strings()...)
			} else {
				ctx.ModuleErrorf("srcs dependency %q is not a source file producing module", m)
			}
		} else {
			expandedExcludes = append(expandedExcludes, filepath.Join(prefix, e))
		}
	}
	expandedSrcFiles := make(Paths, 0, len(srcFiles))
	for _, s := range srcFiles {
		if m := SrcIsModule(s); m != "" {
			module := ctx.GetDirectDepWithTag(m, SourceDepTag)
			if module == nil {
				// Error will have been handled by ExtractSourcesDeps
				continue
			}
			if srcProducer, ok := module.(SourceFileProducer); ok {
				moduleSrcs := srcProducer.Srcs()
				for _, e := range expandedExcludes {
					for j, ms := range moduleSrcs {
						if ms.String() == e {
							moduleSrcs = append(moduleSrcs[:j], moduleSrcs[j+1:]...)
						}
					}
				}
				expandedSrcFiles = append(expandedSrcFiles, moduleSrcs...)
			} else {
				ctx.ModuleErrorf("srcs dependency %q is not a source file producing module", m)
			}
		} else if pathtools.IsGlob(s) {
			globbedSrcFiles := ctx.GlobFiles(filepath.Join(prefix, s), expandedExcludes)
			for i, s := range globbedSrcFiles {
				globbedSrcFiles[i] = s.(ModuleSrcPath).WithSubDir(ctx, subDir)
			}
			expandedSrcFiles = append(expandedSrcFiles, globbedSrcFiles...)
		} else {
			p := PathForModuleSrc(ctx, s).WithSubDir(ctx, subDir)
			j := findStringInSlice(p.String(), expandedExcludes)
			if j == -1 {
				expandedSrcFiles = append(expandedSrcFiles, p)
			}

		}
	}
	return expandedSrcFiles
}

func (ctx *androidModuleContext) RequiredModuleNames() []string {
	return ctx.module.base().commonProperties.Required
}

func (ctx *androidModuleContext) Glob(globPattern string, excludes []string) Paths {
	ret, err := ctx.GlobWithDeps(globPattern, excludes)
	if err != nil {
		ctx.ModuleErrorf("glob: %s", err.Error())
	}
	return pathsForModuleSrcFromFullPath(ctx, ret, true)
}

func (ctx *androidModuleContext) GlobFiles(globPattern string, excludes []string) Paths {
	ret, err := ctx.GlobWithDeps(globPattern, excludes)
	if err != nil {
		ctx.ModuleErrorf("glob: %s", err.Error())
	}
	return pathsForModuleSrcFromFullPath(ctx, ret, false)
}

func init() {
	RegisterSingletonType("buildtarget", BuildTargetSingleton)
}

func BuildTargetSingleton() Singleton {
	return &buildTargetSingleton{}
}

func parentDir(dir string) string {
	dir, _ = filepath.Split(dir)
	return filepath.Clean(dir)
}

type buildTargetSingleton struct{}

func (c *buildTargetSingleton) GenerateBuildActions(ctx SingletonContext) {
	var checkbuildDeps Paths

	mmTarget := func(dir string) WritablePath {
		return PathForPhony(ctx,
			"MODULES-IN-"+strings.Replace(filepath.Clean(dir), "/", "-", -1))
	}

	modulesInDir := make(map[string]Paths)

	ctx.VisitAllModules(func(module Module) {
		blueprintDir := module.base().blueprintDir
		installTarget := module.base().installTarget
		checkbuildTarget := module.base().checkbuildTarget

		if checkbuildTarget != nil {
			checkbuildDeps = append(checkbuildDeps, checkbuildTarget)
			modulesInDir[blueprintDir] = append(modulesInDir[blueprintDir], checkbuildTarget)
		}

		if installTarget != nil {
			modulesInDir[blueprintDir] = append(modulesInDir[blueprintDir], installTarget)
		}
	})

	suffix := ""
	if ctx.Config().EmbeddedInMake() {
		suffix = "-soong"
	}

	// Create a top-level checkbuild target that depends on all modules
	ctx.Build(pctx, BuildParams{
		Rule:      blueprint.Phony,
		Output:    PathForPhony(ctx, "checkbuild"+suffix),
		Implicits: checkbuildDeps,
	})

	// Make will generate the MODULES-IN-* targets
	if ctx.Config().EmbeddedInMake() {
		return
	}

	sortedKeys := func(m map[string]Paths) []string {
		s := make([]string, 0, len(m))
		for k := range m {
			s = append(s, k)
		}
		sort.Strings(s)
		return s
	}

	// Ensure ancestor directories are in modulesInDir
	dirs := sortedKeys(modulesInDir)
	for _, dir := range dirs {
		dir := parentDir(dir)
		for dir != "." && dir != "/" {
			if _, exists := modulesInDir[dir]; exists {
				break
			}
			modulesInDir[dir] = nil
			dir = parentDir(dir)
		}
	}

	// Make directories build their direct subdirectories
	dirs = sortedKeys(modulesInDir)
	for _, dir := range dirs {
		p := parentDir(dir)
		if p != "." && p != "/" {
			modulesInDir[p] = append(modulesInDir[p], mmTarget(dir))
		}
	}

	// Create a MODULES-IN-<directory> target that depends on all modules in a directory, and
	// depends on the MODULES-IN-* targets of all of its subdirectories that contain Android.bp
	// files.
	for _, dir := range dirs {
		ctx.Build(pctx, BuildParams{
			Rule:      blueprint.Phony,
			Output:    mmTarget(dir),
			Implicits: modulesInDir[dir],
			// HACK: checkbuild should be an optional build, but force it
			// enabled for now in standalone builds
			Default: !ctx.Config().EmbeddedInMake(),
		})
	}

	// Create (host|host-cross|target)-<OS> phony rules to build a reduced checkbuild.
	osDeps := map[OsType]Paths{}
	ctx.VisitAllModules(func(module Module) {
		if module.Enabled() {
			os := module.Target().Os
			osDeps[os] = append(osDeps[os], module.base().checkbuildFiles...)
		}
	})

	osClass := make(map[string]Paths)
	for os, deps := range osDeps {
		var className string

		switch os.Class {
		case Host:
			className = "host"
		case HostCross:
			className = "host-cross"
		case Device:
			className = "target"
		default:
			continue
		}

		name := PathForPhony(ctx, className+"-"+os.Name)
		osClass[className] = append(osClass[className], name)

		ctx.Build(pctx, BuildParams{
			Rule:      blueprint.Phony,
			Output:    name,
			Implicits: deps,
		})
	}

	// Wrap those into host|host-cross|target phony rules
	osClasses := sortedKeys(osClass)
	for _, class := range osClasses {
		ctx.Build(pctx, BuildParams{
			Rule:      blueprint.Phony,
			Output:    PathForPhony(ctx, class),
			Implicits: osClass[class],
		})
	}
}

type AndroidModulesByName struct {
	slice []Module
	ctx   interface {
		ModuleName(blueprint.Module) string
		ModuleSubDir(blueprint.Module) string
	}
}

func (s AndroidModulesByName) Len() int { return len(s.slice) }
func (s AndroidModulesByName) Less(i, j int) bool {
	mi, mj := s.slice[i], s.slice[j]
	ni, nj := s.ctx.ModuleName(mi), s.ctx.ModuleName(mj)

	if ni != nj {
		return ni < nj
	} else {
		return s.ctx.ModuleSubDir(mi) < s.ctx.ModuleSubDir(mj)
	}
}
func (s AndroidModulesByName) Swap(i, j int) { s.slice[i], s.slice[j] = s.slice[j], s.slice[i] }