diff --git a/android/androidmk.go b/android/androidmk.go
index 603b37d..8d2951d 100644
--- a/android/androidmk.go
+++ b/android/androidmk.go
@@ -149,27 +149,21 @@
 		name += "_" + data.SubName
 	}
 
-	hostCross := false
-	if amod.Host() && amod.HostType() != CurrentHostType() {
-		hostCross = true
-	}
-
 	if data.Custom != nil {
 		prefix := ""
-		if amod.Host() {
-			if hostCross {
-				prefix = "HOST_CROSS_"
-			} else {
-				prefix = "HOST_"
-			}
-			if amod.Arch().ArchType != ctx.Config().(Config).HostArches[amod.HostType()][0].ArchType {
-				prefix = "2ND_" + prefix
-			}
-		} else {
+		switch amod.Os().Class {
+		case Host:
+			prefix = "HOST_"
+		case HostCross:
+			prefix = "HOST_CROSS_"
+		case Device:
 			prefix = "TARGET_"
-			if amod.Arch().ArchType != ctx.Config().(Config).DeviceArches[0].ArchType {
-				prefix = "2ND_" + prefix
-			}
+
+		}
+
+		config := ctx.Config().(Config)
+		if amod.Arch().ArchType != config.Targets[amod.Os().Class][0].Arch.ArchType {
+			prefix = "2ND_" + prefix
 		}
 
 		return data.Custom(w, name, prefix)
@@ -191,15 +185,15 @@
 	fmt.Fprintln(w, "LOCAL_PREBUILT_MODULE_FILE :=", data.OutputFile.String())
 
 	archStr := amod.Arch().ArchType.String()
-	if amod.Host() {
-		if hostCross {
-			fmt.Fprintln(w, "LOCAL_MODULE_HOST_CROSS_ARCH :=", archStr)
-		} else {
-			fmt.Fprintln(w, "LOCAL_MODULE_HOST_ARCH :=", archStr)
-		}
-		fmt.Fprintln(w, "LOCAL_MODULE_HOST_OS :=", amod.HostType().String())
-		fmt.Fprintln(w, "LOCAL_IS_HOST_MODULE := true")
-	} else {
+	host := false
+	switch amod.Os().Class {
+	case Host:
+		fmt.Fprintln(w, "LOCAL_MODULE_HOST_ARCH :=", archStr)
+		host = true
+	case HostCross:
+		fmt.Fprintln(w, "LOCAL_MODULE_HOST_CROSS_ARCH :=", archStr)
+		host = true
+	case Device:
 		fmt.Fprintln(w, "LOCAL_MODULE_TARGET_ARCH :=", archStr)
 
 		if len(amod.commonProperties.Logtags) > 0 {
@@ -207,6 +201,11 @@
 		}
 	}
 
+	if host {
+		fmt.Fprintln(w, "LOCAL_MODULE_HOST_OS :=", amod.Os().String())
+		fmt.Fprintln(w, "LOCAL_IS_HOST_MODULE := true")
+	}
+
 	for _, extra := range data.Extra {
 		err = extra(w, data.OutputFile.Path())
 		if err != nil {
diff --git a/android/arch.go b/android/arch.go
index 48cc0ab..0673249 100644
--- a/android/arch.go
+++ b/android/arch.go
@@ -28,8 +28,6 @@
 	RegisterBottomUpMutator("defaults_deps", defaultsDepsMutator)
 	RegisterTopDownMutator("defaults", defaultsMutator)
 
-	RegisterBottomUpMutator("host_or_device", HostOrDeviceMutator)
-	RegisterBottomUpMutator("host_type", HostTypeMutator)
 	RegisterBottomUpMutator("arch", ArchMutator)
 }
 
@@ -333,75 +331,7 @@
 	return a.Name
 }
 
-type HostOrDeviceSupported int
-
-const (
-	_ HostOrDeviceSupported = iota
-	HostSupported
-	DeviceSupported
-	HostAndDeviceSupported
-	HostAndDeviceDefault
-)
-
-type HostOrDevice int
-
-const (
-	_ HostOrDevice = iota
-	Host
-	Device
-)
-
-func (hod HostOrDevice) String() string {
-	switch hod {
-	case Device:
-		return "device"
-	case Host:
-		return "host"
-	default:
-		panic(fmt.Sprintf("unexpected HostOrDevice value %d", hod))
-	}
-}
-
-func (hod HostOrDevice) Property() string {
-	switch hod {
-	case Device:
-		return "android"
-	case Host:
-		return "host"
-	default:
-		panic(fmt.Sprintf("unexpected HostOrDevice value %d", hod))
-	}
-}
-
-func (hod HostOrDevice) Host() bool {
-	if hod == 0 {
-		panic("HostOrDevice unset")
-	}
-	return hod == Host
-}
-
-func (hod HostOrDevice) Device() bool {
-	if hod == 0 {
-		panic("HostOrDevice unset")
-	}
-	return hod == Device
-}
-
-var hostOrDeviceName = map[HostOrDevice]string{
-	Device: "device",
-	Host:   "host",
-}
-
-type HostType int
-
-const (
-	NoHostType HostType = iota
-	Linux
-	Darwin
-	Windows
-)
-
-func CurrentHostType() HostType {
+var BuildOs = func() OsType {
 	switch runtime.GOOS {
 	case "linux":
 		return Linux
@@ -410,98 +340,71 @@
 	default:
 		panic(fmt.Sprintf("unsupported OS: %s", runtime.GOOS))
 	}
+}()
+
+var (
+	osTypeList []OsType
+
+	NoOsType OsType
+	Linux    = NewOsType("linux", Host)
+	Darwin   = NewOsType("darwin", Host)
+	Windows  = NewOsType("windows", HostCross)
+	Android  = NewOsType("android", Device)
+)
+
+type OsType struct {
+	Name, Field string
+	Class       OsClass
 }
 
-func (ht HostType) String() string {
-	switch ht {
-	case Linux:
-		return "linux"
-	case Darwin:
-		return "darwin"
-	case Windows:
-		return "windows"
-	default:
-		panic(fmt.Sprintf("unexpected HostType value %d", ht))
-	}
+type OsClass int
+
+const (
+	Device OsClass = iota
+	Host
+	HostCross
+)
+
+func (os OsType) String() string {
+	return os.Name
 }
 
-func (ht HostType) Field() string {
-	switch ht {
-	case Linux:
-		return "Linux"
-	case Darwin:
-		return "Darwin"
-	case Windows:
-		return "Windows"
-	default:
-		panic(fmt.Sprintf("unexpected HostType value %d", ht))
+func NewOsType(name string, class OsClass) OsType {
+	os := OsType{
+		Name:  name,
+		Field: strings.Title(name),
+		Class: class,
 	}
+	osTypeList = append(osTypeList, os)
+	return os
+}
+
+func osByName(name string) OsType {
+	for _, os := range osTypeList {
+		if os.Name == name {
+			return os
+		}
+	}
+
+	return NoOsType
 }
 
 var (
-	commonArch = Arch{
-		ArchType: Common,
+	commonTarget = Target{
+		Os: Android,
+		Arch: Arch{
+			ArchType: Common,
+		},
 	}
 )
 
-func HostOrDeviceMutator(mctx BottomUpMutatorContext) {
-	var module Module
-	var ok bool
-	if module, ok = mctx.Module().(Module); !ok {
-		return
-	}
-
-	hods := []HostOrDevice{}
-
-	if module.base().HostSupported() {
-		hods = append(hods, Host)
-	}
-
-	if module.base().DeviceSupported() {
-		hods = append(hods, Device)
-	}
-
-	if len(hods) == 0 {
-		return
-	}
-
-	hodNames := []string{}
-	for _, hod := range hods {
-		hodNames = append(hodNames, hod.String())
-	}
-
-	modules := mctx.CreateVariations(hodNames...)
-	for i, m := range modules {
-		m.(Module).base().SetHostOrDevice(hods[i])
-	}
+type Target struct {
+	Os   OsType
+	Arch Arch
 }
 
-func HostTypeMutator(mctx BottomUpMutatorContext) {
-	var module Module
-	var ok bool
-	if module, ok = mctx.Module().(Module); !ok {
-		return
-	}
-
-	if !module.base().HostSupported() || !module.base().HostOrDevice().Host() {
-		return
-	}
-
-	buildTypes, err := decodeHostTypesProductVariables(mctx.Config().(Config).ProductVariables)
-	if err != nil {
-		mctx.ModuleErrorf("%s", err.Error())
-		return
-	}
-
-	typeNames := []string{}
-	for _, ht := range buildTypes {
-		typeNames = append(typeNames, ht.String())
-	}
-
-	modules := mctx.CreateVariations(typeNames...)
-	for i, m := range modules {
-		m.(Module).base().SetHostType(buildTypes[i])
-	}
+func (target Target) String() string {
+	return target.Os.String() + "_" + target.Arch.String()
 }
 
 func ArchMutator(mctx BottomUpMutatorContext) {
@@ -511,40 +414,36 @@
 		return
 	}
 
-	moduleArches := []Arch{}
-	multilib := module.base().commonProperties.Compile_multilib
+	osClasses := module.base().OsClassSupported()
 
-	if module.base().HostSupported() && module.base().HostOrDevice().Host() {
-		hostModuleArches, err := decodeMultilib(multilib, mctx.Config().(Config).HostArches[module.base().HostType()])
-		if err != nil {
-			mctx.ModuleErrorf("%s", err.Error())
-		}
-
-		moduleArches = append(moduleArches, hostModuleArches...)
-	}
-
-	if module.base().DeviceSupported() && module.base().HostOrDevice().Device() {
-		deviceModuleArches, err := decodeMultilib(multilib, mctx.Config().(Config).DeviceArches)
-		if err != nil {
-			mctx.ModuleErrorf("%s", err.Error())
-		}
-
-		moduleArches = append(moduleArches, deviceModuleArches...)
-	}
-
-	if len(moduleArches) == 0 {
+	if len(osClasses) == 0 {
 		return
 	}
 
-	archNames := []string{}
-	for _, arch := range moduleArches {
-		archNames = append(archNames, arch.String())
+	var moduleTargets []Target
+
+	for _, class := range osClasses {
+		targets := mctx.AConfig().Targets[class]
+		if len(targets) == 0 {
+			continue
+		}
+		multilib := module.base().commonProperties.Compile_multilib
+		targets, err := decodeMultilib(multilib, targets)
+		if err != nil {
+			mctx.ModuleErrorf("%s", err.Error())
+		}
+		moduleTargets = append(moduleTargets, targets...)
 	}
 
-	modules := mctx.CreateVariations(archNames...)
+	targetNames := make([]string, len(moduleTargets))
 
+	for i, target := range moduleTargets {
+		targetNames[i] = target.String()
+	}
+
+	modules := mctx.CreateVariations(targetNames...)
 	for i, m := range modules {
-		m.(Module).base().SetArch(moduleArches[i])
+		m.(Module).base().SetTarget(moduleTargets[i])
 		m.(Module).base().setArchProperties(mctx)
 	}
 }
@@ -648,9 +547,8 @@
 
 // Rewrite the module's properties structs to contain arch-specific values.
 func (a *ModuleBase) setArchProperties(ctx BottomUpMutatorContext) {
-	arch := a.commonProperties.CompileArch
-	hod := a.commonProperties.CompileHostOrDevice
-	ht := a.commonProperties.CompileHostType
+	arch := a.Arch()
+	os := a.Os()
 
 	if arch.ArchType == Common {
 		return
@@ -719,18 +617,19 @@
 		prefix = "multilib." + t.Multilib
 		a.appendProperties(ctx, genProps, archProps.Multilib, field, prefix)
 
-		// Handle host-or-device-specific properties in the form:
+		// Handle host-specific properties in the form:
 		// target: {
 		//     host: {
 		//         key: value,
 		//     },
 		// },
-		hodProperty := hod.Property()
-		field = proptools.FieldNameForProperty(hodProperty)
-		prefix = "target." + hodProperty
-		a.appendProperties(ctx, genProps, archProps.Target, field, prefix)
+		if os.Class == Host || os.Class == HostCross {
+			field = "Host"
+			prefix = "target.host"
+			a.appendProperties(ctx, genProps, archProps.Target, field, prefix)
+		}
 
-		// Handle host target properties in the form:
+		// Handle target OS properties in the form:
 		// target: {
 		//     linux: {
 		//         key: value,
@@ -744,22 +643,29 @@
 		//     linux_arm: {
 		//         key: value,
 		//     },
+		//     android {
+		//         key: value,
+		//     },
+		//     android_arm {
+		//         key: value,
+		//     },
+		//     android_x86 {
+		//         key: value,
+		//     },
 		// },
-		if hod.Host() {
-			field := ht.Field()
-			prefix := "target." + ht.String()
-			a.appendProperties(ctx, genProps, archProps.Target, field, prefix)
+		// },
+		field = os.Field
+		prefix = "target." + os.Name
+		a.appendProperties(ctx, genProps, archProps.Target, field, prefix)
 
-			t := arch.ArchType
-			field = ht.Field() + "_" + t.Name
-			prefix = "target." + ht.String() + "_" + t.Name
-			a.appendProperties(ctx, genProps, archProps.Target, field, prefix)
+		field = os.Field + "_" + t.Name
+		prefix = "target." + os.Name + "_" + t.Name
+		a.appendProperties(ctx, genProps, archProps.Target, field, prefix)
 
-			if ht != Windows {
-				field := "Not_windows"
-				prefix := "target.not_windows"
-				a.appendProperties(ctx, genProps, archProps.Target, field, prefix)
-			}
+		if (os.Class == Host || os.Class == HostCross) && os != Windows {
+			field := "Not_windows"
+			prefix := "target.not_windows"
+			a.appendProperties(ctx, genProps, archProps.Target, field, prefix)
 		}
 
 		// Handle 64-bit device properties in the form:
@@ -775,8 +681,8 @@
 		// options for all targets on a device that supports 64-bit binaries, not just the targets
 		// that are being compiled for 64-bit.  Its expected use case is binaries like linker and
 		// debuggerd that need to know when they are a 32-bit process running on a 64-bit device
-		if hod.Device() {
-			if true /* && target_is_64_bit */ {
+		if os.Class == Device {
+			if ctx.AConfig().Android64() {
 				field := "Android64"
 				prefix := "target.android64"
 				a.appendProperties(ctx, genProps, archProps.Target, field, prefix)
@@ -786,26 +692,6 @@
 				a.appendProperties(ctx, genProps, archProps.Target, field, prefix)
 			}
 		}
-
-		// Handle device architecture properties in the form:
-		// target {
-		//     android_arm {
-		//         key: value,
-		//     },
-		//     android_x86 {
-		//         key: value,
-		//     },
-		// },
-		if hod.Device() {
-			t := arch.ArchType
-			field := "Android_" + t.Name
-			prefix := "target.android_" + t.Name
-			a.appendProperties(ctx, genProps, archProps.Target, field, prefix)
-		}
-
-		if ctx.Failed() {
-			return
-		}
 	}
 }
 
@@ -824,104 +710,84 @@
 	}
 }
 
-// Get a list of HostTypes from the product variables
-func decodeHostTypesProductVariables(variables productVariables) ([]HostType, error) {
-	ret := []HostType{CurrentHostType()}
+// Convert the arch product variables into a list of targets for each os class structs
+func decodeTargetProductVariables(config Config) (map[OsClass][]Target, error) {
+	variables := config.ProductVariables
 
-	if variables.CrossHost != nil && *variables.CrossHost != "" {
-		switch *variables.CrossHost {
-		case "windows":
-			ret = append(ret, Windows)
-		default:
-			return nil, fmt.Errorf("Unsupported secondary host: %s", *variables.CrossHost)
+	targets := make(map[OsClass][]Target)
+	var targetErr error
+
+	addTarget := func(os OsType, archName string, archVariant, cpuVariant *string, abi *[]string) {
+		if targetErr != nil {
+			return
 		}
+
+		arch, err := decodeArch(archName, archVariant, cpuVariant, abi)
+		if err != nil {
+			targetErr = err
+			return
+		}
+
+		targets[os.Class] = append(targets[os.Class],
+			Target{
+				Os:   os,
+				Arch: arch,
+			})
 	}
 
-	return ret, nil
-}
-
-// Convert the arch product variables into a list of host and device Arch structs
-func decodeArchProductVariables(variables productVariables) (map[HostType][]Arch, []Arch, error) {
 	if variables.HostArch == nil {
-		return nil, nil, fmt.Errorf("No host primary architecture set")
+		return nil, fmt.Errorf("No host primary architecture set")
 	}
 
-	hostArch, err := decodeArch(*variables.HostArch, nil, nil, nil)
-	if err != nil {
-		return nil, nil, err
-	}
-
-	hostArches := []Arch{hostArch}
+	addTarget(BuildOs, *variables.HostArch, nil, nil, nil)
 
 	if variables.HostSecondaryArch != nil && *variables.HostSecondaryArch != "" {
-		hostSecondaryArch, err := decodeArch(*variables.HostSecondaryArch, nil, nil, nil)
-		if err != nil {
-			return nil, nil, err
-		}
-		hostArches = append(hostArches, hostSecondaryArch)
-	}
-
-	hostTypeArches := map[HostType][]Arch{
-		CurrentHostType(): hostArches,
+		addTarget(BuildOs, *variables.HostSecondaryArch, nil, nil, nil)
 	}
 
 	if variables.CrossHost != nil && *variables.CrossHost != "" {
+		crossHostOs := osByName(*variables.CrossHost)
+		if crossHostOs == NoOsType {
+			return nil, fmt.Errorf("Unknown cross host OS %q", *variables.CrossHost)
+		}
+
 		if variables.CrossHostArch == nil || *variables.CrossHostArch == "" {
-			return nil, nil, fmt.Errorf("No cross-host primary architecture set")
+			return nil, fmt.Errorf("No cross-host primary architecture set")
 		}
 
-		crossHostArch, err := decodeArch(*variables.CrossHostArch, nil, nil, nil)
-		if err != nil {
-			return nil, nil, err
-		}
-
-		crossHostArches := []Arch{crossHostArch}
+		addTarget(crossHostOs, *variables.CrossHostArch, nil, nil, nil)
 
 		if variables.CrossHostSecondaryArch != nil && *variables.CrossHostSecondaryArch != "" {
-			crossHostSecondaryArch, err := decodeArch(*variables.CrossHostSecondaryArch, nil, nil, nil)
-			if err != nil {
-				return nil, nil, err
-			}
-			crossHostArches = append(crossHostArches, crossHostSecondaryArch)
-		}
-
-		switch *variables.CrossHost {
-		case "windows":
-			hostTypeArches[Windows] = crossHostArches
-		default:
-			return nil, nil, fmt.Errorf("Unsupported cross-host: %s", *variables.CrossHost)
+			addTarget(crossHostOs, *variables.CrossHostSecondaryArch, nil, nil, nil)
 		}
 	}
 
 	if variables.DeviceArch == nil {
-		return nil, nil, fmt.Errorf("No device primary architecture set")
+		return nil, fmt.Errorf("No device primary architecture set")
 	}
 
-	deviceArch, err := decodeArch(*variables.DeviceArch, variables.DeviceArchVariant,
+	addTarget(Android, *variables.DeviceArch, variables.DeviceArchVariant,
 		variables.DeviceCpuVariant, variables.DeviceAbi)
-	if err != nil {
-		return nil, nil, err
-	}
-
-	deviceArches := []Arch{deviceArch}
 
 	if variables.DeviceSecondaryArch != nil && *variables.DeviceSecondaryArch != "" {
-		deviceSecondaryArch, err := decodeArch(*variables.DeviceSecondaryArch,
+		addTarget(Android, *variables.DeviceSecondaryArch,
 			variables.DeviceSecondaryArchVariant, variables.DeviceSecondaryCpuVariant,
 			variables.DeviceSecondaryAbi)
-		if err != nil {
-			return nil, nil, err
+
+		deviceArches := targets[Device]
+		if deviceArches[0].Arch.ArchType.Multilib == deviceArches[1].Arch.ArchType.Multilib {
+			deviceArches[1].Arch.Native = false
 		}
-		if deviceArch.ArchType.Multilib == deviceSecondaryArch.ArchType.Multilib {
-			deviceSecondaryArch.Native = false
-		}
-		deviceArches = append(deviceArches, deviceSecondaryArch)
 	}
 
-	return hostTypeArches, deviceArches, nil
+	if targetErr != nil {
+		return nil, targetErr
+	}
+
+	return targets, nil
 }
 
-func decodeMegaDevice() ([]Arch, error) {
+func decodeMegaDevice() ([]Target, error) {
 	archSettings := []struct {
 		arch        string
 		archVariant string
@@ -969,7 +835,7 @@
 		{"x86_64", "silvermont", "", []string{"x86_64"}},
 	}
 
-	var ret []Arch
+	var ret []Target
 
 	for _, config := range archSettings {
 		arch, err := decodeArch(config.arch, &config.archVariant,
@@ -978,7 +844,10 @@
 			return nil, err
 		}
 		arch.Native = false
-		ret = append(ret, arch)
+		ret = append(ret, Target{
+			Os:   Android,
+			Arch: arch,
+		})
 	}
 
 	return ret, nil
@@ -1035,33 +904,32 @@
 	return a, nil
 }
 
-// Use the module multilib setting to select one or more arches from an arch list
-func decodeMultilib(multilib string, arches []Arch) ([]Arch, error) {
-	buildArches := []Arch{}
+// Use the module multilib setting to select one or more targets from a target list
+func decodeMultilib(multilib string, targets []Target) ([]Target, error) {
+	buildTargets := []Target{}
 	switch multilib {
 	case "common":
-		buildArches = append(buildArches, commonArch)
+		buildTargets = append(buildTargets, commonTarget)
 	case "both":
-		buildArches = append(buildArches, arches...)
+		buildTargets = append(buildTargets, targets...)
 	case "first":
-		buildArches = append(buildArches, arches[0])
+		buildTargets = append(buildTargets, targets[0])
 	case "32":
-		for _, a := range arches {
-			if a.ArchType.Multilib == "lib32" {
-				buildArches = append(buildArches, a)
+		for _, t := range targets {
+			if t.Arch.ArchType.Multilib == "lib32" {
+				buildTargets = append(buildTargets, t)
 			}
 		}
 	case "64":
-		for _, a := range arches {
-			if a.ArchType.Multilib == "lib64" {
-				buildArches = append(buildArches, a)
+		for _, t := range targets {
+			if t.Arch.ArchType.Multilib == "lib64" {
+				buildTargets = append(buildTargets, t)
 			}
 		}
 	default:
 		return nil, fmt.Errorf(`compile_multilib must be "both", "first", "32", or "64", found %q`,
 			multilib)
-		//buildArches = append(buildArches, arches[0])
 	}
 
-	return buildArches, nil
+	return buildTargets, nil
 }
diff --git a/android/config.go b/android/config.go
index ee95d2e..5024bce 100644
--- a/android/config.go
+++ b/android/config.go
@@ -54,8 +54,8 @@
 	ConfigFileName           string
 	ProductVariablesFileName string
 
-	DeviceArches []Arch
-	HostArches   map[HostType][]Arch
+	Targets        map[OsClass][]Target
+	BuildOsVariant string
 
 	srcDir   string // the path of the root source directory
 	buildDir string // the path of the build output directory
@@ -175,20 +175,21 @@
 		config.inMake = true
 	}
 
-	hostArches, deviceArches, err := decodeArchProductVariables(config.ProductVariables)
+	targets, err := decodeTargetProductVariables(config)
 	if err != nil {
 		return Config{}, err
 	}
 
 	if Bool(config.Mega_device) {
-		deviceArches, err = decodeMegaDevice()
+		deviceTargets, err := decodeMegaDevice()
 		if err != nil {
 			return Config{}, err
 		}
+		targets[Device] = deviceTargets
 	}
 
-	config.HostArches = hostArches
-	config.DeviceArches = deviceArches
+	config.Targets = targets
+	config.BuildOsVariant = targets[Host][0].String()
 
 	return config, nil
 }
@@ -325,3 +326,13 @@
 	}
 	return *c.ProductVariables.SanitizeDevice
 }
+
+func (c *config) Android64() bool {
+	for _, t := range c.Targets[Device] {
+		if t.Arch.ArchType.Multilib == "lib64" {
+			return true
+		}
+	}
+
+	return false
+}
diff --git a/android/module.go b/android/module.go
index 1855523..0e608d7 100644
--- a/android/module.go
+++ b/android/module.go
@@ -48,9 +48,9 @@
 }
 
 type androidBaseContext interface {
+	Target() Target
 	Arch() Arch
-	HostOrDevice() HostOrDevice
-	HostType() HostType
+	Os() OsType
 	Host() bool
 	Device() bool
 	Darwin() bool
@@ -90,7 +90,7 @@
 
 	base() *ModuleBase
 	Enabled() bool
-	HostOrDevice() HostOrDevice
+	Target() Target
 	InstallInData() bool
 }
 
@@ -115,14 +115,8 @@
 	// file
 	Logtags []string
 
-	// Set by HostOrDeviceMutator
-	CompileHostOrDevice HostOrDevice `blueprint:"mutated"`
-
-	// Set by HostTypeMutator
-	CompileHostType HostType `blueprint:"mutated"`
-
-	// Set by ArchMutator
-	CompileArch Arch `blueprint:"mutated"`
+	// Set by TargetMutator
+	CompileTarget Target `blueprint:"mutated"`
 
 	// Set by InitAndroidModule
 	HostOrDeviceSupported HostOrDeviceSupported `blueprint:"mutated"`
@@ -142,6 +136,16 @@
 	MultilibDefault Multilib = ""
 )
 
+type HostOrDeviceSupported int
+
+const (
+	_ HostOrDeviceSupported = iota
+	HostSupported
+	DeviceSupported
+	HostAndDeviceSupported
+	HostAndDeviceDefault
+)
+
 func InitAndroidModule(m Module,
 	propertyStructs ...interface{}) (blueprint.Module, []interface{}) {
 
@@ -241,38 +245,45 @@
 	return a
 }
 
-func (a *ModuleBase) SetHostOrDevice(hod HostOrDevice) {
-	a.commonProperties.CompileHostOrDevice = hod
+func (a *ModuleBase) SetTarget(target Target) {
+	a.commonProperties.CompileTarget = target
 }
 
-func (a *ModuleBase) SetHostType(ht HostType) {
-	a.commonProperties.CompileHostType = ht
+func (a *ModuleBase) Target() Target {
+	return a.commonProperties.CompileTarget
 }
 
-func (a *ModuleBase) SetArch(arch Arch) {
-	a.commonProperties.CompileArch = arch
-}
-
-func (a *ModuleBase) HostOrDevice() HostOrDevice {
-	return a.commonProperties.CompileHostOrDevice
-}
-
-func (a *ModuleBase) HostType() HostType {
-	return a.commonProperties.CompileHostType
+func (a *ModuleBase) Os() OsType {
+	return a.Target().Os
 }
 
 func (a *ModuleBase) Host() bool {
-	return a.HostOrDevice().Host()
+	return a.Os().Class == Host || a.Os().Class == HostCross
 }
 
 func (a *ModuleBase) Arch() Arch {
-	return a.commonProperties.CompileArch
+	return a.Target().Arch
 }
 
-func (a *ModuleBase) HostSupported() bool {
-	return a.commonProperties.HostOrDeviceSupported == HostSupported ||
-		a.commonProperties.HostOrDeviceSupported == HostAndDeviceSupported &&
-			a.hostAndDeviceProperties.Host_supported
+func (a *ModuleBase) OsClassSupported() []OsClass {
+	switch a.commonProperties.HostOrDeviceSupported {
+	case HostSupported:
+		// TODO(ccross): explicitly mark host cross support
+		return []OsClass{Host, HostCross}
+	case DeviceSupported:
+		return []OsClass{Device}
+	case HostAndDeviceSupported:
+		var supported []OsClass
+		if a.hostAndDeviceProperties.Host_supported {
+			supported = append(supported, Host, HostCross)
+		}
+		if a.hostAndDeviceProperties.Device_supported {
+			supported = append(supported, Device)
+		}
+		return supported
+	default:
+		return nil
+	}
 }
 
 func (a *ModuleBase) DeviceSupported() bool {
@@ -283,11 +294,7 @@
 
 func (a *ModuleBase) Enabled() bool {
 	if a.commonProperties.Enabled == nil {
-		if a.HostSupported() && a.HostOrDevice().Host() && a.HostType() == Windows {
-			return false
-		} else {
-			return true
-		}
+		return a.Os().Class != HostCross
 	}
 	return *a.commonProperties.Enabled
 }
@@ -376,9 +383,7 @@
 
 func (a *ModuleBase) androidBaseContextFactory(ctx blueprint.BaseModuleContext) androidBaseContextImpl {
 	return androidBaseContextImpl{
-		arch:          a.commonProperties.CompileArch,
-		hod:           a.commonProperties.CompileHostOrDevice,
-		ht:            a.commonProperties.CompileHostType,
+		target:        a.commonProperties.CompileTarget,
 		proprietary:   a.commonProperties.Proprietary,
 		config:        ctx.Config().(Config),
 		installInData: a.module.InstallInData(),
@@ -413,9 +418,7 @@
 }
 
 type androidBaseContextImpl struct {
-	arch          Arch
-	hod           HostOrDevice
-	ht            HostType
+	target        Target
 	debug         bool
 	config        Config
 	proprietary   bool
@@ -494,28 +497,28 @@
 	}
 }
 
+func (a *androidBaseContextImpl) Target() Target {
+	return a.target
+}
+
 func (a *androidBaseContextImpl) Arch() Arch {
-	return a.arch
+	return a.target.Arch
 }
 
-func (a *androidBaseContextImpl) HostOrDevice() HostOrDevice {
-	return a.hod
-}
-
-func (a *androidBaseContextImpl) HostType() HostType {
-	return a.ht
+func (a *androidBaseContextImpl) Os() OsType {
+	return a.target.Os
 }
 
 func (a *androidBaseContextImpl) Host() bool {
-	return a.hod.Host()
+	return a.target.Os.Class == Host || a.target.Os.Class == HostCross
 }
 
 func (a *androidBaseContextImpl) Device() bool {
-	return a.hod.Device()
+	return a.target.Os.Class == Device
 }
 
 func (a *androidBaseContextImpl) Darwin() bool {
-	return a.hod.Host() && a.ht == Darwin
+	return a.target.Os == Darwin
 }
 
 func (a *androidBaseContextImpl) Debug() bool {
diff --git a/android/paths.go b/android/paths.go
index 910ebd2..35ed180 100644
--- a/android/paths.go
+++ b/android/paths.go
@@ -629,7 +629,7 @@
 		}
 		outPaths = []string{"target", "product", ctx.AConfig().DeviceName(), partition}
 	} else {
-		outPaths = []string{"host", ctx.HostType().String() + "-x86"}
+		outPaths = []string{"host", ctx.Os().String() + "-x86"}
 	}
 	if ctx.Debug() {
 		outPaths = append([]string{"debug"}, outPaths...)
diff --git a/cc/arm64_device.go b/cc/arm64_device.go
index 4e41287..8e7c57b 100644
--- a/cc/arm64_device.go
+++ b/cc/arm64_device.go
@@ -208,5 +208,5 @@
 }
 
 func init() {
-	registerDeviceToolchainFactory(android.Arm64, arm64ToolchainFactory)
+	registerToolchainFactory(android.Android, android.Arm64, arm64ToolchainFactory)
 }
diff --git a/cc/arm_device.go b/cc/arm_device.go
index 766eea6..1624cfc 100644
--- a/cc/arm_device.go
+++ b/cc/arm_device.go
@@ -392,5 +392,5 @@
 }
 
 func init() {
-	registerDeviceToolchainFactory(android.Arm, armToolchainFactory)
+	registerToolchainFactory(android.Android, android.Arm, armToolchainFactory)
 }
diff --git a/cc/cc.go b/cc/cc.go
index bac3e88..3cc0d0d 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -118,7 +118,7 @@
 )
 
 func init() {
-	if android.CurrentHostType() == android.Linux {
+	if android.BuildOs == android.Linux {
 		commonGlobalCflags = append(commonGlobalCflags, "-fdebug-prefix-map=/proc/self/cwd=")
 	}
 
@@ -729,11 +729,10 @@
 func (c *Module) toolchain(ctx BaseModuleContext) Toolchain {
 	if c.cachedToolchain == nil {
 		arch := ctx.Arch()
-		hod := ctx.HostOrDevice()
-		ht := ctx.HostType()
-		factory := toolchainFactories[hod][ht][arch.ArchType]
+		os := ctx.Os()
+		factory := toolchainFactories[os][arch.ArchType]
 		if factory == nil {
-			ctx.ModuleErrorf("Toolchain not found for %s %s arch %q", hod.String(), ht.String(), arch.String())
+			ctx.ModuleErrorf("Toolchain not found for %s arch %q", os.String(), arch.String())
 			return nil
 		}
 		c.cachedToolchain = factory(arch)
@@ -905,8 +904,13 @@
 			return
 		}
 
-		if a.HostOrDevice() != ctx.HostOrDevice() {
-			ctx.ModuleErrorf("host/device mismatch between %q and %q", ctx.ModuleName(), name)
+		if a.Target().Os != ctx.Os() {
+			ctx.ModuleErrorf("OS mismatch between %q and %q", ctx.ModuleName(), name)
+			return
+		}
+
+		if a.Target().Arch.ArchType != ctx.Arch().ArchType {
+			ctx.ModuleErrorf("Arch mismatch between %q and %q", ctx.ModuleName(), name)
 			return
 		}
 
@@ -1081,6 +1085,11 @@
 		flags.LdFlags = append(flags.LdFlags, target, gccPrefix)
 	}
 
+	hod := "host"
+	if ctx.Os().Class == android.Device {
+		hod = "device"
+	}
+
 	if !ctx.noDefaultCompilerFlags() {
 		flags.GlobalFlags = append(flags.GlobalFlags, instructionSetFlags)
 
@@ -1090,7 +1099,7 @@
 			flags.GlobalFlags = append(flags.GlobalFlags,
 				toolchain.ClangCflags(),
 				"${commonClangGlobalCflags}",
-				fmt.Sprintf("${%sClangGlobalCflags}", ctx.HostOrDevice()))
+				fmt.Sprintf("${%sClangGlobalCflags}", hod))
 
 			flags.ConlyFlags = append(flags.ConlyFlags, "${clangExtraConlyflags}")
 		} else {
@@ -1098,7 +1107,7 @@
 			flags.GlobalFlags = append(flags.GlobalFlags,
 				toolchain.Cflags(),
 				"${commonGlobalCflags}",
-				fmt.Sprintf("${%sGlobalCflags}", ctx.HostOrDevice()))
+				fmt.Sprintf("${%sGlobalCflags}", hod))
 		}
 
 		if Bool(ctx.AConfig().ProductVariables.Brillo) {
@@ -1410,7 +1419,7 @@
 	// MinGW spits out warnings about -fPIC even for -fpie?!) being ignored because
 	// all code is position independent, and then those warnings get promoted to
 	// errors.
-	if ctx.HostType() != android.Windows {
+	if ctx.Os() != android.Windows {
 		flags.CFlags = append(flags.CFlags, "-fPIC")
 	}
 
@@ -1863,7 +1872,7 @@
 
 	static := Bool(binary.Properties.Static_executable)
 	if ctx.Host() {
-		if ctx.HostType() == android.Linux {
+		if ctx.Os() == android.Linux {
 			if binary.Properties.Static_executable == nil && Bool(ctx.AConfig().ProductVariables.HostStaticBinaries) {
 				static = true
 			}
@@ -1883,7 +1892,7 @@
 
 	if ctx.Host() && !binary.staticBinary() {
 		flags.LdFlags = append(flags.LdFlags, "-pie")
-		if ctx.HostType() == android.Windows {
+		if ctx.Os() == android.Windows {
 			flags.LdFlags = append(flags.LdFlags, "-Wl,-e_mainCRTStartup")
 		}
 	}
@@ -1891,7 +1900,7 @@
 	// MinGW spits out warnings about -fPIC even for -fpie?!) being ignored because
 	// all code is position independent, and then those warnings get promoted to
 	// errors.
-	if ctx.HostType() != android.Windows {
+	if ctx.Os() != android.Windows {
 		flags.CFlags = append(flags.CFlags, "-fpie")
 	}
 
@@ -1945,7 +1954,7 @@
 	fileName := binary.getStem(ctx) + flags.Toolchain.ExecutableSuffix()
 	outputFile := android.PathForModuleOut(ctx, fileName)
 	ret := outputFile
-	if ctx.HostOrDevice().Host() {
+	if ctx.Os().Class == android.Host {
 		binary.hostToolPath = android.OptionalPathForPath(outputFile)
 	}
 
@@ -2052,7 +2061,7 @@
 	if ctx.Host() {
 		flags.CFlags = append(flags.CFlags, "-O0", "-g")
 
-		switch ctx.HostType() {
+		switch ctx.Os() {
 		case android.Windows:
 			flags.CFlags = append(flags.CFlags, "-DGTEST_OS_WINDOWS")
 		case android.Linux:
diff --git a/cc/makevars.go b/cc/makevars.go
index 863e3dc..f107eff 100644
--- a/cc/makevars.go
+++ b/cc/makevars.go
@@ -41,49 +41,54 @@
 	ctx.Strict("GLOBAL_CPPFLAGS_NO_OVERRIDE", "")
 	ctx.Strict("GLOBAL_CLANG_CPPFLAGS_NO_OVERRIDE", "")
 
-	hostType := android.CurrentHostType()
-	arches := ctx.Config().HostArches[hostType]
-	makeVarsToolchain(ctx, "", android.Host, hostType, arches[0])
-	if len(arches) > 1 {
-		makeVarsToolchain(ctx, "2ND_", android.Host, hostType, arches[1])
+	hostTargets := ctx.Config().Targets[android.Host]
+	makeVarsToolchain(ctx, "", hostTargets[0])
+	if len(hostTargets) > 1 {
+		makeVarsToolchain(ctx, "2ND_", hostTargets[1])
 	}
 
-	if winArches, ok := ctx.Config().HostArches[android.Windows]; ok {
-		makeVarsToolchain(ctx, "", android.Host, android.Windows, winArches[0])
-		if len(winArches) > 1 {
-			makeVarsToolchain(ctx, "2ND_", android.Host, android.Windows, winArches[1])
+	crossTargets := ctx.Config().Targets[android.HostCross]
+	if len(crossTargets) > 0 {
+		makeVarsToolchain(ctx, "", crossTargets[0])
+		if len(crossTargets) > 1 {
+			makeVarsToolchain(ctx, "2ND_", crossTargets[1])
 		}
 	}
 
-	arches = ctx.Config().DeviceArches
-	makeVarsToolchain(ctx, "", android.Device, android.NoHostType, arches[0])
-	if len(arches) > 1 {
-		makeVarsToolchain(ctx, "2ND_", android.Device, android.NoHostType, arches[1])
+	deviceTargets := ctx.Config().Targets[android.Device]
+	makeVarsToolchain(ctx, "", deviceTargets[0])
+	if len(deviceTargets) > 1 {
+		makeVarsToolchain(ctx, "2ND_", deviceTargets[1])
 	}
 }
 
 func makeVarsToolchain(ctx android.MakeVarsContext, secondPrefix string,
-	hod android.HostOrDevice, ht android.HostType, arch android.Arch) {
+	target android.Target) {
 	var typePrefix string
-	if hod.Host() {
-		if ht == android.Windows {
-			typePrefix = "HOST_CROSS_"
-		} else {
-			typePrefix = "HOST_"
-		}
-	} else {
+	switch target.Os.Class {
+	case android.Host:
+		typePrefix = "HOST_"
+	case android.HostCross:
+		typePrefix = "HOST_CROSS_"
+	case android.Device:
 		typePrefix = "TARGET_"
 	}
 	makePrefix := secondPrefix + typePrefix
 
-	toolchain := toolchainFactories[hod][ht][arch.ArchType](arch)
+	toolchain := toolchainFactories[target.Os][target.Arch.ArchType](target.Arch)
 
 	var productExtraCflags string
 	var productExtraLdflags string
-	if hod.Device() && Bool(ctx.Config().ProductVariables.Brillo) {
+
+	hod := "host"
+	if target.Os.Class == android.Device {
+		hod = "device"
+	}
+
+	if target.Os.Class == android.Device && Bool(ctx.Config().ProductVariables.Brillo) {
 		productExtraCflags += "-D__BRILLO__"
 	}
-	if hod.Host() && Bool(ctx.Config().ProductVariables.HostStaticBinaries) {
+	if target.Os.Class == android.Host && Bool(ctx.Config().ProductVariables.HostStaticBinaries) {
 		productExtraLdflags += "-static"
 	}
 
@@ -108,23 +113,29 @@
 	ctx.Strict(makePrefix+"SYSTEMCPP_LDFLAGS", toolchain.SystemCppLdflags())
 
 	includeFlags, err := ctx.Eval(toolchain.IncludeFlags())
-	if err != nil { panic(err) }
+	if err != nil {
+		panic(err)
+	}
 	ctx.StrictRaw(makePrefix+"C_INCLUDES", strings.Replace(includeFlags, "-isystem ", "", -1))
 
-	if arch.ArchType == android.Arm {
+	if target.Arch.ArchType == android.Arm {
 		flags, err := toolchain.InstructionSetFlags("arm")
-		if err != nil { panic(err) }
+		if err != nil {
+			panic(err)
+		}
 		ctx.Strict(makePrefix+"arm_CFLAGS", flags)
 
 		flags, err = toolchain.InstructionSetFlags("thumb")
-		if err != nil { panic(err) }
+		if err != nil {
+			panic(err)
+		}
 		ctx.Strict(makePrefix+"thumb_CFLAGS", flags)
 	}
 
 	if toolchain.ClangSupported() {
 		clangPrefix := secondPrefix + "CLANG_" + typePrefix
 		clangExtras := "-target " + toolchain.ClangTriple()
-		if ht != android.Darwin {
+		if target.Os != android.Darwin {
 			clangExtras += " -B" + filepath.Join(toolchain.GccRoot(), toolchain.GccTriple(), "bin")
 		}
 
@@ -148,19 +159,19 @@
 			clangExtras,
 		}, " "))
 
-		if hod.Device() {
-			ctx.Strict(secondPrefix + "ADDRESS_SANITIZER_RUNTIME_LIBRARY", strings.TrimSuffix(toolchain.AddressSanitizerRuntimeLibrary(), ".so"))
+		if target.Os.Class == android.Device {
+			ctx.Strict(secondPrefix+"ADDRESS_SANITIZER_RUNTIME_LIBRARY", strings.TrimSuffix(toolchain.AddressSanitizerRuntimeLibrary(), ".so"))
 		}
 
 		// This is used by external/gentoo/...
-		ctx.Strict("CLANG_CONFIG_" + arch.ArchType.Name + "_" + typePrefix + "TRIPLE",
+		ctx.Strict("CLANG_CONFIG_"+target.Arch.ArchType.Name+"_"+typePrefix+"TRIPLE",
 			toolchain.ClangTriple())
 	}
 
 	ctx.Strict(makePrefix+"CC", gccCmd(toolchain, "gcc"))
 	ctx.Strict(makePrefix+"CXX", gccCmd(toolchain, "g++"))
 
-	if ht == android.Darwin {
+	if target.Os == android.Darwin {
 		ctx.Strict(makePrefix+"AR", "${macArPath}")
 	} else {
 		ctx.Strict(makePrefix+"AR", gccCmd(toolchain, "ar"))
@@ -168,11 +179,11 @@
 		ctx.Strict(makePrefix+"NM", gccCmd(toolchain, "nm"))
 	}
 
-	if ht == android.Windows {
+	if target.Os == android.Windows {
 		ctx.Strict(makePrefix+"OBJDUMP", gccCmd(toolchain, "objdump"))
 	}
 
-	if hod.Device() {
+	if target.Os.Class == android.Device {
 		ctx.Strict(makePrefix+"OBJCOPY", gccCmd(toolchain, "objcopy"))
 		ctx.Strict(makePrefix+"LD", gccCmd(toolchain, "ld"))
 		ctx.Strict(makePrefix+"STRIP", gccCmd(toolchain, "strip"))
diff --git a/cc/mips64_device.go b/cc/mips64_device.go
index 04e31a9..474f284 100644
--- a/cc/mips64_device.go
+++ b/cc/mips64_device.go
@@ -200,5 +200,5 @@
 }
 
 func init() {
-	registerDeviceToolchainFactory(android.Mips64, mips64ToolchainFactory)
+	registerToolchainFactory(android.Android, android.Mips64, mips64ToolchainFactory)
 }
diff --git a/cc/mips_device.go b/cc/mips_device.go
index 0dbbbd7..f9dc5c6 100644
--- a/cc/mips_device.go
+++ b/cc/mips_device.go
@@ -248,5 +248,5 @@
 }
 
 func init() {
-	registerDeviceToolchainFactory(android.Mips, mipsToolchainFactory)
+	registerToolchainFactory(android.Android, android.Mips, mipsToolchainFactory)
 }
diff --git a/cc/stl.go b/cc/stl.go
index cdc887e..c5dbae3 100644
--- a/cc/stl.go
+++ b/cc/stl.go
@@ -52,7 +52,7 @@
 				ctx.ModuleErrorf("stl: %q is not a supported STL with sdk_version set", stl.Properties.Stl)
 				return ""
 			}
-		} else if ctx.HostType() == android.Windows {
+		} else if ctx.Os() == android.Windows {
 			switch stl.Properties.Stl {
 			case "libc++", "libc++_static", "libstdc++", "":
 				// libc++ is not supported on mingw
@@ -60,7 +60,7 @@
 			case "none":
 				return ""
 			default:
-				ctx.ModuleErrorf("stl: %q is not a supported STL", stl.Properties.Stl)
+				ctx.ModuleErrorf("stl: %q is not a supported STL for windows", stl.Properties.Stl)
 				return ""
 			}
 		} else {
@@ -133,9 +133,9 @@
 			flags.LdFlags = append(flags.LdFlags, "-nodefaultlibs")
 			flags.LdFlags = append(flags.LdFlags, "-lpthread", "-lm")
 			if ctx.staticBinary() {
-				flags.LdFlags = append(flags.LdFlags, hostStaticGccLibs[ctx.HostType()]...)
+				flags.LdFlags = append(flags.LdFlags, hostStaticGccLibs[ctx.Os()]...)
 			} else {
-				flags.LdFlags = append(flags.LdFlags, hostDynamicGccLibs[ctx.HostType()]...)
+				flags.LdFlags = append(flags.LdFlags, hostDynamicGccLibs[ctx.Os()]...)
 			}
 		} else {
 			if ctx.Arch().ArchType == android.Arm {
@@ -167,9 +167,9 @@
 			flags.CppFlags = append(flags.CppFlags, "-nostdinc++")
 			flags.LdFlags = append(flags.LdFlags, "-nodefaultlibs")
 			if ctx.staticBinary() {
-				flags.LdFlags = append(flags.LdFlags, hostStaticGccLibs[ctx.HostType()]...)
+				flags.LdFlags = append(flags.LdFlags, hostStaticGccLibs[ctx.Os()]...)
 			} else {
-				flags.LdFlags = append(flags.LdFlags, hostDynamicGccLibs[ctx.HostType()]...)
+				flags.LdFlags = append(flags.LdFlags, hostDynamicGccLibs[ctx.Os()]...)
 			}
 		}
 	default:
@@ -179,10 +179,10 @@
 	return flags
 }
 
-var hostDynamicGccLibs, hostStaticGccLibs map[android.HostType][]string
+var hostDynamicGccLibs, hostStaticGccLibs map[android.OsType][]string
 
 func init() {
-	hostDynamicGccLibs = map[android.HostType][]string{
+	hostDynamicGccLibs = map[android.OsType][]string{
 		android.Linux:  []string{"-lgcc_s", "-lgcc", "-lc", "-lgcc_s", "-lgcc"},
 		android.Darwin: []string{"-lc", "-lSystem"},
 		android.Windows: []string{"-lmsvcr110", "-lmingw32", "-lgcc", "-lmoldname",
@@ -190,7 +190,7 @@
 			"-lkernel32", "-lmingw32", "-lgcc", "-lmoldname", "-lmingwex",
 			"-lmsvcrt"},
 	}
-	hostStaticGccLibs = map[android.HostType][]string{
+	hostStaticGccLibs = map[android.OsType][]string{
 		android.Linux:   []string{"-Wl,--start-group", "-lgcc", "-lgcc_eh", "-lc", "-Wl,--end-group"},
 		android.Darwin:  []string{"NO_STATIC_HOST_BINARIES_ON_DARWIN"},
 		android.Windows: []string{"NO_STATIC_HOST_BINARIES_ON_WINDOWS"},
diff --git a/cc/toolchain.go b/cc/toolchain.go
index efb7953..87657ef 100644
--- a/cc/toolchain.go
+++ b/cc/toolchain.go
@@ -22,23 +22,13 @@
 
 type toolchainFactory func(arch android.Arch) Toolchain
 
-var toolchainFactories = map[android.HostOrDevice]map[android.HostType]map[android.ArchType]toolchainFactory{
-	android.Host: map[android.HostType]map[android.ArchType]toolchainFactory{
-		android.Linux:   make(map[android.ArchType]toolchainFactory),
-		android.Darwin:  make(map[android.ArchType]toolchainFactory),
-		android.Windows: make(map[android.ArchType]toolchainFactory),
-	},
-	android.Device: map[android.HostType]map[android.ArchType]toolchainFactory{
-		android.NoHostType: make(map[android.ArchType]toolchainFactory),
-	},
-}
+var toolchainFactories = make(map[android.OsType]map[android.ArchType]toolchainFactory)
 
-func registerDeviceToolchainFactory(arch android.ArchType, factory toolchainFactory) {
-	toolchainFactories[android.Device][android.NoHostType][arch] = factory
-}
-
-func registerHostToolchainFactory(ht android.HostType, arch android.ArchType, factory toolchainFactory) {
-	toolchainFactories[android.Host][ht][arch] = factory
+func registerToolchainFactory(os android.OsType, arch android.ArchType, factory toolchainFactory) {
+	if toolchainFactories[os] == nil {
+		toolchainFactories[os] = make(map[android.ArchType]toolchainFactory)
+	}
+	toolchainFactories[os][arch] = factory
 }
 
 type Toolchain interface {
diff --git a/cc/x86_64_device.go b/cc/x86_64_device.go
index 9a0d663..986dc86 100644
--- a/cc/x86_64_device.go
+++ b/cc/x86_64_device.go
@@ -263,5 +263,5 @@
 }
 
 func init() {
-	registerDeviceToolchainFactory(android.X86_64, x86_64ToolchainFactory)
+	registerToolchainFactory(android.Android, android.X86_64, x86_64ToolchainFactory)
 }
diff --git a/cc/x86_darwin_host.go b/cc/x86_darwin_host.go
index f3cf1c9..987b1dd 100644
--- a/cc/x86_darwin_host.go
+++ b/cc/x86_darwin_host.go
@@ -280,6 +280,6 @@
 }
 
 func init() {
-	registerHostToolchainFactory(android.Darwin, android.X86, darwinX86ToolchainFactory)
-	registerHostToolchainFactory(android.Darwin, android.X86_64, darwinX8664ToolchainFactory)
+	registerToolchainFactory(android.Darwin, android.X86, darwinX86ToolchainFactory)
+	registerToolchainFactory(android.Darwin, android.X86_64, darwinX8664ToolchainFactory)
 }
diff --git a/cc/x86_device.go b/cc/x86_device.go
index e47c6fb..f16e68b 100644
--- a/cc/x86_device.go
+++ b/cc/x86_device.go
@@ -286,5 +286,5 @@
 }
 
 func init() {
-	registerDeviceToolchainFactory(android.X86, x86ToolchainFactory)
+	registerToolchainFactory(android.Android, android.X86, x86ToolchainFactory)
 }
diff --git a/cc/x86_linux_host.go b/cc/x86_linux_host.go
index a75de90..b2d8462 100644
--- a/cc/x86_linux_host.go
+++ b/cc/x86_linux_host.go
@@ -254,6 +254,6 @@
 }
 
 func init() {
-	registerHostToolchainFactory(android.Linux, android.X86, linuxX86ToolchainFactory)
-	registerHostToolchainFactory(android.Linux, android.X86_64, linuxX8664ToolchainFactory)
+	registerToolchainFactory(android.Linux, android.X86, linuxX86ToolchainFactory)
+	registerToolchainFactory(android.Linux, android.X86_64, linuxX8664ToolchainFactory)
 }
diff --git a/cc/x86_windows_host.go b/cc/x86_windows_host.go
index 9f5cdc4..cc0ef66 100644
--- a/cc/x86_windows_host.go
+++ b/cc/x86_windows_host.go
@@ -199,6 +199,6 @@
 }
 
 func init() {
-	registerHostToolchainFactory(android.Windows, android.X86, windowsX86ToolchainFactory)
-	registerHostToolchainFactory(android.Windows, android.X86_64, windowsX8664ToolchainFactory)
+	registerToolchainFactory(android.Windows, android.X86, windowsX86ToolchainFactory)
+	registerToolchainFactory(android.Windows, android.X86_64, windowsX8664ToolchainFactory)
 }
diff --git a/genrule/genrule.go b/genrule/genrule.go
index a195b24..a50af1c 100644
--- a/genrule/genrule.go
+++ b/genrule/genrule.go
@@ -97,8 +97,7 @@
 	if g, ok := ctx.Module().(*generator); ok {
 		if g.properties.Tool != "" {
 			ctx.AddFarVariationDependencies([]blueprint.Variation{
-				{"host_or_device", android.Host.String()},
-				{"host_type", android.CurrentHostType().String()},
+				{"arch", ctx.AConfig().BuildOsVariant},
 			}, nil, g.properties.Tool)
 		}
 	}