diff --git a/java/aapt2.go b/java/aapt2.go
index fd7388e..61e9451 100644
--- a/java/aapt2.go
+++ b/java/aapt2.go
@@ -111,7 +111,8 @@
 
 var aapt2LinkRule = pctx.AndroidStaticRule("aapt2Link",
 	blueprint.RuleParams{
-		Command: `${config.Aapt2Cmd} link -o $out $flags --java $genDir --proguard $proguardOptions $inFlags && ` +
+		Command: `${config.Aapt2Cmd} link -o $out $flags --java $genDir --proguard $proguardOptions ` +
+			`--output-text-symbols ${rTxt} $inFlags && ` +
 			`${config.SoongZipCmd} -write_if_changed -jar -o $genJar -C $genDir -D $genDir`,
 		CommandDeps: []string{
 			"${config.Aapt2Cmd}",
@@ -119,7 +120,7 @@
 		},
 		Restat: true,
 	},
-	"flags", "inFlags", "proguardOptions", "genDir", "genJar")
+	"flags", "inFlags", "proguardOptions", "genDir", "genJar", "rTxt")
 
 var fileListToFileRule = pctx.AndroidStaticRule("fileListToFile",
 	blueprint.RuleParams{
@@ -129,7 +130,7 @@
 	})
 
 func aapt2Link(ctx android.ModuleContext,
-	packageRes, genJar, proguardOptions android.WritablePath,
+	packageRes, genJar, proguardOptions, rTxt android.WritablePath,
 	flags []string, deps android.Paths,
 	compiledRes, compiledOverlay android.Paths) {
 
@@ -171,13 +172,14 @@
 		Description:     "aapt2 link",
 		Implicits:       deps,
 		Output:          packageRes,
-		ImplicitOutputs: android.WritablePaths{proguardOptions, genJar},
+		ImplicitOutputs: android.WritablePaths{proguardOptions, genJar, rTxt},
 		Args: map[string]string{
 			"flags":           strings.Join(flags, " "),
 			"inFlags":         strings.Join(inFlags, " "),
 			"proguardOptions": proguardOptions.String(),
 			"genDir":          genDir.String(),
 			"genJar":          genJar.String(),
+			"rTxt":            rTxt.String(),
 		},
 	})
 }
diff --git a/java/aar.go b/java/aar.go
index 0df3632..57c752c 100644
--- a/java/aar.go
+++ b/java/aar.go
@@ -16,21 +16,307 @@
 
 import (
 	"android/soong/android"
+	"strings"
 
 	"github.com/google/blueprint"
+	"github.com/google/blueprint/proptools"
 )
 
+type AndroidLibraryDependency interface {
+	Dependency
+	ExportPackage() android.Path
+}
+
+func init() {
+	android.RegisterModuleType("android_library_import", AARImportFactory)
+	android.RegisterModuleType("android_library", AndroidLibraryFactory)
+}
+
+//
+// AAR (android library)
+//
+
+type androidLibraryProperties struct {
+	BuildAAR bool `blueprint:"mutated"`
+}
+
+type aaptProperties struct {
+	// flags passed to aapt when creating the apk
+	Aaptflags []string
+
+	// list of directories relative to the Blueprints file containing assets.
+	// Defaults to "assets"
+	Asset_dirs []string
+
+	// list of directories relative to the Blueprints file containing
+	// Android resources
+	Resource_dirs []string
+
+	// path to AndroidManifest.xml.  If unset, defaults to "AndroidManifest.xml".
+	Manifest *string
+}
+
+type aapt struct {
+	aaptSrcJar          android.Path
+	exportPackage       android.Path
+	manifestPath        android.Path
+	proguardOptionsFile android.Path
+	rroDirs             android.Paths
+	rTxt                android.Path
+
+	aaptProperties aaptProperties
+}
+
+func (a *aapt) ExportPackage() android.Path {
+	return a.exportPackage
+}
+
+func (a *aapt) aapt2Flags(ctx android.ModuleContext, sdkVersion string) (flags []string, deps android.Paths,
+	resDirs, overlayDirs []globbedResourceDir, overlayFiles, rroDirs android.Paths, manifestPath android.Path) {
+
+	hasVersionCode := false
+	hasVersionName := false
+	hasProduct := false
+	for _, f := range a.aaptProperties.Aaptflags {
+		if strings.HasPrefix(f, "--version-code") {
+			hasVersionCode = true
+		} else if strings.HasPrefix(f, "--version-name") {
+			hasVersionName = true
+		} else if strings.HasPrefix(f, "--product") {
+			hasProduct = true
+		}
+	}
+
+	var linkFlags []string
+
+	// Flags specified in Android.bp
+	linkFlags = append(linkFlags, a.aaptProperties.Aaptflags...)
+
+	linkFlags = append(linkFlags, "--no-static-lib-packages")
+
+	// Find implicit or explicit asset and resource dirs
+	assetDirs := android.PathsWithOptionalDefaultForModuleSrc(ctx, a.aaptProperties.Asset_dirs, "assets")
+	resourceDirs := android.PathsWithOptionalDefaultForModuleSrc(ctx, a.aaptProperties.Resource_dirs, "res")
+
+	var linkDeps android.Paths
+
+	// Glob directories into lists of paths
+	for _, dir := range resourceDirs {
+		resDirs = append(resDirs, globbedResourceDir{
+			dir:   dir,
+			files: androidResourceGlob(ctx, dir),
+		})
+		resOverlayDirs, resRRODirs := overlayResourceGlob(ctx, dir)
+		overlayDirs = append(overlayDirs, resOverlayDirs...)
+		rroDirs = append(rroDirs, resRRODirs...)
+	}
+
+	var assetFiles android.Paths
+	for _, dir := range assetDirs {
+		assetFiles = append(assetFiles, androidResourceGlob(ctx, dir)...)
+	}
+
+	// App manifest file
+	manifestFile := proptools.StringDefault(a.aaptProperties.Manifest, "AndroidManifest.xml")
+	manifestPath = android.PathForModuleSrc(ctx, manifestFile)
+	linkFlags = append(linkFlags, "--manifest "+manifestPath.String())
+	linkDeps = append(linkDeps, manifestPath)
+
+	linkFlags = append(linkFlags, android.JoinWithPrefix(assetDirs.Strings(), "-A "))
+	linkDeps = append(linkDeps, assetFiles...)
+
+	staticLibs, libDeps, libFlags := aaptLibs(ctx, sdkVersion)
+
+	overlayFiles = append(overlayFiles, staticLibs...)
+	linkDeps = append(linkDeps, libDeps...)
+	linkFlags = append(linkFlags, libFlags...)
+
+	// SDK version flags
+	switch sdkVersion {
+	case "", "current", "system_current", "test_current":
+		sdkVersion = proptools.NinjaEscape([]string{ctx.Config().AppsDefaultVersionName()})[0]
+	}
+
+	linkFlags = append(linkFlags, "--min-sdk-version "+sdkVersion)
+	linkFlags = append(linkFlags, "--target-sdk-version "+sdkVersion)
+
+	// Product characteristics
+	if !hasProduct && len(ctx.Config().ProductAAPTCharacteristics()) > 0 {
+		linkFlags = append(linkFlags, "--product", ctx.Config().ProductAAPTCharacteristics())
+	}
+
+	// Product AAPT config
+	for _, aaptConfig := range ctx.Config().ProductAAPTConfig() {
+		linkFlags = append(linkFlags, "-c", aaptConfig)
+	}
+
+	// Product AAPT preferred config
+	if len(ctx.Config().ProductAAPTPreferredConfig()) > 0 {
+		linkFlags = append(linkFlags, "--preferred-density", ctx.Config().ProductAAPTPreferredConfig())
+	}
+
+	// Version code
+	if !hasVersionCode {
+		linkFlags = append(linkFlags, "--version-code", ctx.Config().PlatformSdkVersion())
+	}
+
+	if !hasVersionName {
+		versionName := proptools.NinjaEscape([]string{ctx.Config().AppsDefaultVersionName()})[0]
+		linkFlags = append(linkFlags, "--version-name ", versionName)
+	}
+
+	return linkFlags, linkDeps, resDirs, overlayDirs, overlayFiles, rroDirs, manifestPath
+}
+
+func (a *aapt) deps(ctx android.BottomUpMutatorContext, sdkVersion string) {
+	if !ctx.Config().UnbundledBuild() {
+		sdkDep := decodeSdkDep(ctx, sdkVersion)
+		if sdkDep.frameworkResModule != "" {
+			ctx.AddDependency(ctx.Module(), frameworkResTag, sdkDep.frameworkResModule)
+		}
+	}
+}
+
+func (a *aapt) buildActions(ctx android.ModuleContext, sdkVersion string, extraLinkFlags ...string) {
+	linkFlags, linkDeps, resDirs, overlayDirs, overlayFiles, rroDirs, manifestPath := a.aapt2Flags(ctx, sdkVersion)
+
+	linkFlags = append(linkFlags, extraLinkFlags...)
+
+	packageRes := android.PathForModuleOut(ctx, "package-res.apk")
+	srcJar := android.PathForModuleGen(ctx, "R.jar")
+	proguardOptionsFile := android.PathForModuleGen(ctx, "proguard.options")
+	rTxt := android.PathForModuleOut(ctx, "R.txt")
+
+	var compiledRes, compiledOverlay android.Paths
+	for _, dir := range resDirs {
+		compiledRes = append(compiledRes, aapt2Compile(ctx, dir.dir, dir.files).Paths()...)
+	}
+	for _, dir := range overlayDirs {
+		compiledOverlay = append(compiledOverlay, aapt2Compile(ctx, dir.dir, dir.files).Paths()...)
+	}
+
+	compiledOverlay = append(compiledOverlay, overlayFiles...)
+
+	aapt2Link(ctx, packageRes, srcJar, proguardOptionsFile, rTxt,
+		linkFlags, linkDeps, compiledRes, compiledOverlay)
+
+	a.aaptSrcJar = srcJar
+	a.exportPackage = packageRes
+	a.manifestPath = manifestPath
+	a.proguardOptionsFile = proguardOptionsFile
+	a.rroDirs = rroDirs
+	a.rTxt = rTxt
+}
+
+// aaptLibs collects libraries from dependencies and sdk_version and converts them into paths
+func aaptLibs(ctx android.ModuleContext, sdkVersion string) (staticLibs, deps android.Paths, flags []string) {
+	var sharedLibs android.Paths
+
+	sdkDep := decodeSdkDep(ctx, sdkVersion)
+	if sdkDep.useFiles {
+		sharedLibs = append(sharedLibs, sdkDep.jar)
+	}
+
+	ctx.VisitDirectDeps(func(module android.Module) {
+		var exportPackage android.Path
+		if aarDep, ok := module.(AndroidLibraryDependency); ok {
+			exportPackage = aarDep.ExportPackage()
+		}
+
+		switch ctx.OtherModuleDependencyTag(module) {
+		case libTag, frameworkResTag:
+			if exportPackage != nil {
+				sharedLibs = append(sharedLibs, exportPackage)
+			}
+		case staticLibTag:
+			if exportPackage != nil {
+				staticLibs = append(staticLibs, exportPackage)
+			}
+		}
+	})
+
+	deps = append(deps, sharedLibs...)
+	deps = append(deps, staticLibs...)
+
+	if len(staticLibs) > 0 {
+		flags = append(flags, "--auto-add-overlay")
+	}
+
+	for _, sharedLib := range sharedLibs {
+		flags = append(flags, "-I "+sharedLib.String())
+	}
+
+	return staticLibs, deps, flags
+}
+
+type AndroidLibrary struct {
+	Library
+	aapt
+
+	androidLibraryProperties androidLibraryProperties
+
+	aarFile android.WritablePath
+}
+
+var _ AndroidLibraryDependency = (*AndroidLibrary)(nil)
+
+func (a *AndroidLibrary) DepsMutator(ctx android.BottomUpMutatorContext) {
+	a.Module.deps(ctx)
+	if !Bool(a.properties.No_framework_libs) && !Bool(a.properties.No_standard_libs) {
+		a.aapt.deps(ctx, String(a.deviceProperties.Sdk_version))
+	}
+}
+
+func (a *AndroidLibrary) GenerateAndroidBuildActions(ctx android.ModuleContext) {
+	a.aapt.buildActions(ctx, String(a.deviceProperties.Sdk_version), "--static-lib")
+
+	ctx.CheckbuildFile(a.proguardOptionsFile)
+	ctx.CheckbuildFile(a.exportPackage)
+	ctx.CheckbuildFile(a.aaptSrcJar)
+
+	// apps manifests are handled by aapt, don't let Module see them
+	a.properties.Manifest = nil
+
+	a.Module.extraProguardFlagFiles = append(a.Module.extraProguardFlagFiles,
+		a.proguardOptionsFile)
+
+	a.Module.compile(ctx, a.aaptSrcJar)
+
+	a.aarFile = android.PathForOutput(ctx, ctx.ModuleName()+".aar")
+	var res android.Paths
+	if a.androidLibraryProperties.BuildAAR {
+		BuildAAR(ctx, a.aarFile, a.outputFile, a.manifestPath, a.rTxt, res)
+		ctx.CheckbuildFile(a.aarFile)
+	}
+}
+
+func AndroidLibraryFactory() android.Module {
+	module := &AndroidLibrary{}
+
+	module.AddProperties(
+		&module.Module.properties,
+		&module.Module.deviceProperties,
+		&module.Module.protoProperties,
+		&module.aaptProperties,
+		&module.androidLibraryProperties)
+
+	module.androidLibraryProperties.BuildAAR = true
+
+	android.InitAndroidArchModule(module, android.DeviceSupported, android.MultilibCommon)
+	return module
+}
+
 //
 // AAR (android library) prebuilts
 //
-func init() {
-	android.RegisterModuleType("android_library_import", AARImportFactory)
-}
 
 type AARImportProperties struct {
 	Aars []string
 
 	Sdk_version *string
+
+	Static_libs []string
+	Libs        []string
 }
 
 type AARImport struct {
@@ -44,6 +330,12 @@
 	exportPackage android.WritablePath
 }
 
+var _ AndroidLibraryDependency = (*AARImport)(nil)
+
+func (a *AARImport) ExportPackage() android.Path {
+	return a.exportPackage
+}
+
 func (a *AARImport) Prebuilt() *android.Prebuilt {
 	return &a.prebuilt
 }
@@ -53,13 +345,15 @@
 }
 
 func (a *AARImport) DepsMutator(ctx android.BottomUpMutatorContext) {
-	// TODO: this should use decodeSdkDep once that knows about current
 	if !ctx.Config().UnbundledBuild() {
-		switch String(a.properties.Sdk_version) { // TODO: Res_sdk_version?
-		case "current", "system_current", "test_current", "":
-			ctx.AddDependency(ctx.Module(), frameworkResTag, "framework-res")
+		sdkDep := decodeSdkDep(ctx, String(a.properties.Sdk_version))
+		if sdkDep.useModule && sdkDep.frameworkResModule != "" {
+			ctx.AddDependency(ctx.Module(), frameworkResTag, sdkDep.frameworkResModule)
 		}
 	}
+
+	ctx.AddDependency(ctx.Module(), staticLibTag, a.properties.Libs...)
+	ctx.AddDependency(ctx.Module(), staticLibTag, a.properties.Static_libs...)
 }
 
 // Unzip an AAR into its constituent files and directories.  Any files in Outputs that don't exist in the AAR will be
@@ -105,6 +399,7 @@
 	a.exportPackage = android.PathForModuleOut(ctx, "package-res.apk")
 	srcJar := android.PathForModuleGen(ctx, "R.jar")
 	proguardOptionsFile := android.PathForModuleGen(ctx, "proguard.options")
+	rTxt := android.PathForModuleOut(ctx, "R.txt")
 
 	var linkDeps android.Paths
 
@@ -117,30 +412,15 @@
 	linkFlags = append(linkFlags, "--manifest "+manifest.String())
 	linkDeps = append(linkDeps, manifest)
 
-	// Include dirs
-	ctx.VisitDirectDeps(func(module android.Module) {
-		var depFiles android.Paths
-		if javaDep, ok := module.(Dependency); ok {
-			// TODO: shared android libraries
-			if ctx.OtherModuleName(module) == "framework-res" {
-				depFiles = android.Paths{javaDep.(*AndroidApp).exportPackage}
-			}
-		}
+	staticLibs, libDeps, libFlags := aaptLibs(ctx, String(a.properties.Sdk_version))
 
-		for _, dep := range depFiles {
-			linkFlags = append(linkFlags, "-I "+dep.String())
-		}
-		linkDeps = append(linkDeps, depFiles...)
-	})
+	linkDeps = append(linkDeps, libDeps...)
+	linkFlags = append(linkFlags, libFlags...)
 
-	sdkDep := decodeSdkDep(ctx, String(a.properties.Sdk_version))
-	if sdkDep.useFiles {
-		linkFlags = append(linkFlags, "-I "+sdkDep.jar.String())
-		linkDeps = append(linkDeps, sdkDep.jar)
-	}
+	overlayRes := append(android.Paths{flata}, staticLibs...)
 
-	aapt2Link(ctx, a.exportPackage, srcJar, proguardOptionsFile,
-		linkFlags, linkDeps, nil, android.Paths{flata})
+	aapt2Link(ctx, a.exportPackage, srcJar, proguardOptionsFile, rTxt,
+		linkFlags, linkDeps, nil, overlayRes)
 }
 
 var _ Dependency = (*AARImport)(nil)
diff --git a/java/android_resources.go b/java/android_resources.go
new file mode 100644
index 0000000..47535d2
--- /dev/null
+++ b/java/android_resources.go
@@ -0,0 +1,127 @@
+// Copyright 2018 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 java
+
+import (
+	"path/filepath"
+	"strings"
+
+	"android/soong/android"
+)
+
+func init() {
+	android.RegisterPreSingletonType("overlay", OverlaySingletonFactory)
+}
+
+var androidResourceIgnoreFilenames = []string{
+	".svn",
+	".git",
+	".ds_store",
+	"*.scc",
+	".*",
+	"CVS",
+	"thumbs.db",
+	"picasa.ini",
+	"*~",
+}
+
+func androidResourceGlob(ctx android.ModuleContext, dir android.Path) android.Paths {
+	return ctx.GlobFiles(filepath.Join(dir.String(), "**/*"), androidResourceIgnoreFilenames)
+}
+
+type overlayGlobResult struct {
+	dir   string
+	paths android.DirectorySortedPaths
+
+	// Set to true of the product has selected that values in this overlay should not be moved to
+	// Runtime Resource Overlay (RRO) packages.
+	excludeFromRRO bool
+}
+
+const overlayDataKey = "overlayDataKey"
+
+type globbedResourceDir struct {
+	dir   android.Path
+	files android.Paths
+}
+
+func overlayResourceGlob(ctx android.ModuleContext, dir android.Path) (res []globbedResourceDir,
+	rroDirs android.Paths) {
+
+	overlayData := ctx.Config().Get(overlayDataKey).([]overlayGlobResult)
+
+	// Runtime resource overlays (RRO) may be turned on by the product config for some modules
+	rroEnabled := ctx.Config().EnforceRROForModule(ctx.ModuleName())
+
+	for _, data := range overlayData {
+		files := data.paths.PathsInDirectory(filepath.Join(data.dir, dir.String()))
+		if len(files) > 0 {
+			overlayModuleDir := android.PathForSource(ctx, data.dir, dir.String())
+			// If enforce RRO is enabled for this module and this overlay is not in the
+			// exclusion list, ignore the overlay.  The list of ignored overlays will be
+			// passed to Make to be turned into an RRO package.
+			if rroEnabled && !data.excludeFromRRO {
+				rroDirs = append(rroDirs, overlayModuleDir)
+			} else {
+				res = append(res, globbedResourceDir{
+					dir:   overlayModuleDir,
+					files: files,
+				})
+			}
+		}
+	}
+
+	return res, rroDirs
+}
+
+func OverlaySingletonFactory() android.Singleton {
+	return overlaySingleton{}
+}
+
+type overlaySingleton struct{}
+
+func (overlaySingleton) GenerateBuildActions(ctx android.SingletonContext) {
+	var overlayData []overlayGlobResult
+	overlayDirs := ctx.Config().ResourceOverlays()
+	for i := range overlayDirs {
+		// Iterate backwards through the list of overlay directories so that the later, lower-priority
+		// directories in the list show up earlier in the command line to aapt2.
+		overlay := overlayDirs[len(overlayDirs)-1-i]
+		var result overlayGlobResult
+		result.dir = overlay
+
+		// Mark overlays that will not have Runtime Resource Overlays enforced on them
+		// based on the product config
+		result.excludeFromRRO = ctx.Config().EnforceRROExcludedOverlay(overlay)
+
+		files, err := ctx.GlobWithDeps(filepath.Join(overlay, "**/*"), androidResourceIgnoreFilenames)
+		if err != nil {
+			ctx.Errorf("failed to glob resource dir %q: %s", overlay, err.Error())
+			continue
+		}
+		var paths android.Paths
+		for _, f := range files {
+			if !strings.HasSuffix(f, "/") {
+				paths = append(paths, android.PathForSource(ctx, f))
+			}
+		}
+		result.paths = android.PathsToDirectorySortedPaths(paths)
+		overlayData = append(overlayData, result)
+	}
+
+	ctx.Config().Once(overlayDataKey, func() interface{} {
+		return overlayData
+	})
+}
diff --git a/java/androidmk.go b/java/androidmk.go
index 204b3d9..dfbe7fa 100644
--- a/java/androidmk.go
+++ b/java/androidmk.go
@@ -223,7 +223,31 @@
 			},
 		},
 	}
+}
 
+func (a *AndroidLibrary) AndroidMk() android.AndroidMkData {
+	data := a.Library.AndroidMk()
+
+	data.Extra = append(data.Extra, func(w io.Writer, outputFile android.Path) {
+		if a.proguardDictionary != nil {
+			fmt.Fprintln(w, "LOCAL_SOONG_PROGUARD_DICT :=", a.proguardDictionary.String())
+		}
+
+		if a.Name() == "framework-res" {
+			fmt.Fprintln(w, "LOCAL_MODULE_PATH := $(TARGET_OUT_JAVA_LIBRARIES)")
+			// Make base_rules.mk not put framework-res in a subdirectory called
+			// framework_res.
+			fmt.Fprintln(w, "LOCAL_NO_STANDARD_LIBRARIES := true")
+		}
+
+		fmt.Fprintln(w, "LOCAL_SOONG_RESOURCE_EXPORT_PACKAGE :=", a.exportPackage.String())
+		fmt.Fprintln(w, "LOCAL_FULL_MANIFEST_FILE :=", a.manifestPath.String())
+		fmt.Fprintln(w, "LOCAL_SOONG_EXPORT_PROGUARD_FLAGS :=", a.proguardOptionsFile.String())
+		fmt.Fprintln(w, "LOCAL_UNINSTALLABLE_MODULE := true")
+		fmt.Fprintln(w, "LOCAL_DEX_PREOPT := false")
+	})
+
+	return data
 }
 
 func (jd *Javadoc) AndroidMk() android.AndroidMkData {
diff --git a/java/app.go b/java/app.go
index c94d22f..3e24ebc 100644
--- a/java/app.go
+++ b/java/app.go
@@ -17,7 +17,6 @@
 // This file contains the module types for compiling Android apps.
 
 import (
-	"path/filepath"
 	"strings"
 
 	"github.com/google/blueprint/proptools"
@@ -26,11 +25,9 @@
 )
 
 func init() {
-	android.RegisterPreSingletonType("overlay", OverlaySingletonFactory)
 	android.RegisterModuleType("android_app", AndroidAppFactory)
 }
 
-// AAR prebuilts
 // AndroidManifest.xml merging
 // package splits
 
@@ -46,91 +43,59 @@
 	// use to get PRODUCT-agnostic resource data like IDs and type definitions.
 	Export_package_resources *bool
 
-	// flags passed to aapt when creating the apk
-	Aaptflags []string
-
-	// list of resource labels to generate individual resource packages
-	Package_splits []string
-
-	// list of directories relative to the Blueprints file containing assets.
-	// Defaults to "assets"
-	Asset_dirs []string
-
-	// list of directories relative to the Blueprints file containing
-	// Android resources
-	Resource_dirs []string
-
-	Instrumentation_for *string
-
 	// Specifies that this app should be installed to the priv-app directory,
 	// where the system will grant it additional privileges not available to
 	// normal apps.
 	Privileged *bool
+
+	// list of resource labels to generate individual resource packages
+	Package_splits []string
+
+	Instrumentation_for *string
 }
 
 type AndroidApp struct {
-	Module
+	Library
+	aapt
+
+	certificate certificate
 
 	appProperties appProperties
-
-	aaptSrcJar    android.Path
-	exportPackage android.Path
-	rroDirs       android.Paths
-	manifestPath  android.Path
-	certificate   certificate
 }
 
+var _ AndroidLibraryDependency = (*AndroidApp)(nil)
+
 type certificate struct {
 	pem, key android.Path
 }
 
 func (a *AndroidApp) DepsMutator(ctx android.BottomUpMutatorContext) {
 	a.Module.deps(ctx)
-
 	if !Bool(a.properties.No_framework_libs) && !Bool(a.properties.No_standard_libs) {
-		switch String(a.deviceProperties.Sdk_version) { // TODO: Res_sdk_version?
-		case "current", "system_current", "test_current", "":
-			ctx.AddDependency(ctx.Module(), frameworkResTag, "framework-res")
-		default:
-			// We'll already have a dependency on an sdk prebuilt android.jar
-		}
+		a.aapt.deps(ctx, String(a.deviceProperties.Sdk_version))
 	}
 }
 
 func (a *AndroidApp) GenerateAndroidBuildActions(ctx android.ModuleContext) {
-	linkFlags, linkDeps, resDirs, overlayDirs, rroDirs, manifestPath := a.aapt2Flags(ctx)
-
-	packageRes := android.PathForModuleOut(ctx, "package-res.apk")
-	srcJar := android.PathForModuleGen(ctx, "R.jar")
-	proguardOptionsFile := android.PathForModuleGen(ctx, "proguard.options")
-
-	var compiledRes, compiledOverlay android.Paths
-	for _, dir := range resDirs {
-		compiledRes = append(compiledRes, aapt2Compile(ctx, dir.dir, dir.files).Paths()...)
-	}
-	for _, dir := range overlayDirs {
-		compiledOverlay = append(compiledOverlay, aapt2Compile(ctx, dir.dir, dir.files).Paths()...)
+	var linkFlags []string
+	if String(a.appProperties.Instrumentation_for) != "" {
+		linkFlags = append(linkFlags,
+			"--rename-instrumentation-target-package",
+			String(a.appProperties.Instrumentation_for))
+	} else {
+		a.properties.Instrument = true
 	}
 
-	aapt2Link(ctx, packageRes, srcJar, proguardOptionsFile,
-		linkFlags, linkDeps, compiledRes, compiledOverlay)
+	// TODO: LOCAL_PACKAGE_OVERRIDES
+	//    $(addprefix --rename-manifest-package , $(PRIVATE_MANIFEST_PACKAGE_NAME)) \
 
-	a.exportPackage = packageRes
-	a.aaptSrcJar = srcJar
-
-	ctx.CheckbuildFile(proguardOptionsFile)
-	ctx.CheckbuildFile(a.exportPackage)
-	ctx.CheckbuildFile(a.aaptSrcJar)
+	a.aapt.buildActions(ctx, String(a.deviceProperties.Sdk_version), linkFlags...)
 
 	// apps manifests are handled by aapt, don't let Module see them
 	a.properties.Manifest = nil
 
-	if String(a.appProperties.Instrumentation_for) == "" {
-		a.properties.Instrument = true
-	}
-
 	a.Module.extraProguardFlagFiles = append(a.Module.extraProguardFlagFiles,
-		proguardOptionsFile)
+		a.proguardOptionsFile)
 
 	if ctx.ModuleName() != "framework-res" {
 		a.Module.compile(ctx, a.aaptSrcJar)
@@ -167,8 +132,6 @@
 	CreateAppPackage(ctx, packageFile, a.exportPackage, a.outputFile, certificates)
 
 	a.outputFile = packageFile
-	a.rroDirs = rroDirs
-	a.manifestPath = manifestPath
 
 	if ctx.ModuleName() == "framework-res" {
 		// framework-res.apk is installed as system/framework/framework-res.apk
@@ -180,152 +143,6 @@
 	}
 }
 
-var aaptIgnoreFilenames = []string{
-	".svn",
-	".git",
-	".ds_store",
-	"*.scc",
-	".*",
-	"CVS",
-	"thumbs.db",
-	"picasa.ini",
-	"*~",
-}
-
-type globbedResourceDir struct {
-	dir   android.Path
-	files android.Paths
-}
-
-func (a *AndroidApp) aapt2Flags(ctx android.ModuleContext) (flags []string, deps android.Paths,
-	resDirs, overlayDirs []globbedResourceDir, rroDirs android.Paths, manifestPath android.Path) {
-
-	hasVersionCode := false
-	hasVersionName := false
-	hasProduct := false
-	for _, f := range a.appProperties.Aaptflags {
-		if strings.HasPrefix(f, "--version-code") {
-			hasVersionCode = true
-		} else if strings.HasPrefix(f, "--version-name") {
-			hasVersionName = true
-		} else if strings.HasPrefix(f, "--product") {
-			hasProduct = true
-		}
-	}
-
-	var linkFlags []string
-
-	// Flags specified in Android.bp
-	linkFlags = append(linkFlags, a.appProperties.Aaptflags...)
-
-	linkFlags = append(linkFlags, "--no-static-lib-packages")
-
-	// Find implicit or explicit asset and resource dirs
-	assetDirs := android.PathsWithOptionalDefaultForModuleSrc(ctx, a.appProperties.Asset_dirs, "assets")
-	resourceDirs := android.PathsWithOptionalDefaultForModuleSrc(ctx, a.appProperties.Resource_dirs, "res")
-
-	var linkDeps android.Paths
-
-	// Glob directories into lists of paths
-	for _, dir := range resourceDirs {
-		resDirs = append(resDirs, globbedResourceDir{
-			dir:   dir,
-			files: resourceGlob(ctx, dir),
-		})
-		resOverlayDirs, resRRODirs := overlayResourceGlob(ctx, dir)
-		overlayDirs = append(overlayDirs, resOverlayDirs...)
-		rroDirs = append(rroDirs, resRRODirs...)
-	}
-
-	var assetFiles android.Paths
-	for _, dir := range assetDirs {
-		assetFiles = append(assetFiles, resourceGlob(ctx, dir)...)
-	}
-
-	// App manifest file
-	var manifestFile string
-	if a.properties.Manifest == nil {
-		manifestFile = "AndroidManifest.xml"
-	} else {
-		manifestFile = *a.properties.Manifest
-	}
-
-	manifestPath = android.PathForModuleSrc(ctx, manifestFile)
-	linkFlags = append(linkFlags, "--manifest "+manifestPath.String())
-	linkDeps = append(linkDeps, manifestPath)
-
-	linkFlags = append(linkFlags, android.JoinWithPrefix(assetDirs.Strings(), "-A "))
-	linkDeps = append(linkDeps, assetFiles...)
-
-	// Include dirs
-	ctx.VisitDirectDeps(func(module android.Module) {
-		var depFiles android.Paths
-		if javaDep, ok := module.(Dependency); ok {
-			// TODO: shared android libraries
-			if ctx.OtherModuleName(module) == "framework-res" {
-				depFiles = android.Paths{javaDep.(*AndroidApp).exportPackage}
-			}
-		}
-
-		for _, dep := range depFiles {
-			linkFlags = append(linkFlags, "-I "+dep.String())
-		}
-		linkDeps = append(linkDeps, depFiles...)
-	})
-
-	sdkDep := decodeSdkDep(ctx, String(a.deviceProperties.Sdk_version))
-	if sdkDep.useFiles {
-		linkFlags = append(linkFlags, "-I "+sdkDep.jar.String())
-		linkDeps = append(linkDeps, sdkDep.jar)
-	}
-
-	// SDK version flags
-	sdkVersion := String(a.deviceProperties.Sdk_version)
-	switch sdkVersion {
-	case "", "current", "system_current", "test_current":
-		sdkVersion = proptools.NinjaEscape([]string{ctx.Config().AppsDefaultVersionName()})[0]
-	}
-
-	linkFlags = append(linkFlags, "--min-sdk-version "+sdkVersion)
-	linkFlags = append(linkFlags, "--target-sdk-version "+sdkVersion)
-
-	// Product characteristics
-	if !hasProduct && len(ctx.Config().ProductAAPTCharacteristics()) > 0 {
-		linkFlags = append(linkFlags, "--product", ctx.Config().ProductAAPTCharacteristics())
-	}
-
-	// Product AAPT config
-	for _, aaptConfig := range ctx.Config().ProductAAPTConfig() {
-		linkFlags = append(linkFlags, "-c", aaptConfig)
-	}
-
-	// Product AAPT preferred config
-	if len(ctx.Config().ProductAAPTPreferredConfig()) > 0 {
-		linkFlags = append(linkFlags, "--preferred-density", ctx.Config().ProductAAPTPreferredConfig())
-	}
-
-	// Version code
-	if !hasVersionCode {
-		linkFlags = append(linkFlags, "--version-code", ctx.Config().PlatformSdkVersion())
-	}
-
-	if !hasVersionName {
-		versionName := proptools.NinjaEscape([]string{ctx.Config().AppsDefaultVersionName()})[0]
-		linkFlags = append(linkFlags, "--version-name ", versionName)
-	}
-
-	if String(a.appProperties.Instrumentation_for) != "" {
-		linkFlags = append(linkFlags,
-			"--rename-instrumentation-target-package",
-			String(a.appProperties.Instrumentation_for))
-	}
-
-	// TODO: LOCAL_PACKAGE_OVERRIDES
-	//    $(addprefix --rename-manifest-package , $(PRIVATE_MANIFEST_PACKAGE_NAME)) \
-
-	return linkFlags, linkDeps, resDirs, overlayDirs, rroDirs, manifestPath
-}
-
 func AndroidAppFactory() android.Module {
 	module := &AndroidApp{}
 
@@ -335,92 +152,10 @@
 	module.AddProperties(
 		&module.Module.properties,
 		&module.Module.deviceProperties,
+		&module.Module.protoProperties,
+		&module.aaptProperties,
 		&module.appProperties)
 
 	android.InitAndroidArchModule(module, android.DeviceSupported, android.MultilibCommon)
 	return module
 }
-
-func resourceGlob(ctx android.ModuleContext, dir android.Path) android.Paths {
-	return ctx.GlobFiles(filepath.Join(dir.String(), "**/*"), aaptIgnoreFilenames)
-}
-
-type overlayGlobResult struct {
-	dir   string
-	paths android.DirectorySortedPaths
-
-	// Set to true of the product has selected that values in this overlay should not be moved to
-	// Runtime Resource Overlay (RRO) packages.
-	excludeFromRRO bool
-}
-
-const overlayDataKey = "overlayDataKey"
-
-func overlayResourceGlob(ctx android.ModuleContext, dir android.Path) (res []globbedResourceDir,
-	rroDirs android.Paths) {
-
-	overlayData := ctx.Config().Get(overlayDataKey).([]overlayGlobResult)
-
-	// Runtime resource overlays (RRO) may be turned on by the product config for some modules
-	rroEnabled := ctx.Config().EnforceRROForModule(ctx.ModuleName())
-
-	for _, data := range overlayData {
-		files := data.paths.PathsInDirectory(filepath.Join(data.dir, dir.String()))
-		if len(files) > 0 {
-			overlayModuleDir := android.PathForSource(ctx, data.dir, dir.String())
-			// If enforce RRO is enabled for this module and this overlay is not in the
-			// exclusion list, ignore the overlay.  The list of ignored overlays will be
-			// passed to Make to be turned into an RRO package.
-			if rroEnabled && !data.excludeFromRRO {
-				rroDirs = append(rroDirs, overlayModuleDir)
-			} else {
-				res = append(res, globbedResourceDir{
-					dir:   overlayModuleDir,
-					files: files,
-				})
-			}
-		}
-	}
-
-	return res, rroDirs
-}
-
-func OverlaySingletonFactory() android.Singleton {
-	return overlaySingleton{}
-}
-
-type overlaySingleton struct{}
-
-func (overlaySingleton) GenerateBuildActions(ctx android.SingletonContext) {
-	var overlayData []overlayGlobResult
-	overlayDirs := ctx.Config().ResourceOverlays()
-	for i := range overlayDirs {
-		// Iterate backwards through the list of overlay directories so that the later, lower-priority
-		// directories in the list show up earlier in the command line to aapt2.
-		overlay := overlayDirs[len(overlayDirs)-1-i]
-		var result overlayGlobResult
-		result.dir = overlay
-
-		// Mark overlays that will not have Runtime Resource Overlays enforced on them
-		// based on the product config
-		result.excludeFromRRO = ctx.Config().EnforceRROExcludedOverlay(overlay)
-
-		files, err := ctx.GlobWithDeps(filepath.Join(overlay, "**/*"), aaptIgnoreFilenames)
-		if err != nil {
-			ctx.Errorf("failed to glob resource dir %q: %s", overlay, err.Error())
-			continue
-		}
-		var paths android.Paths
-		for _, f := range files {
-			if !strings.HasSuffix(f, "/") {
-				paths = append(paths, android.PathForSource(ctx, f))
-			}
-		}
-		result.paths = android.PathsToDirectorySortedPaths(paths)
-		overlayData = append(overlayData, result)
-	}
-
-	ctx.Config().Once(overlayDataKey, func() interface{} {
-		return overlayData
-	})
-}
diff --git a/java/app_builder.go b/java/app_builder.go
index 945d7bd..954ca44 100644
--- a/java/app_builder.go
+++ b/java/app_builder.go
@@ -96,3 +96,39 @@
 		},
 	})
 }
+
+var buildAAR = pctx.AndroidStaticRule("buildAAR",
+	blueprint.RuleParams{
+		Command: `rm -rf ${outDir} && mkdir -p ${outDir} && ` +
+			`cp ${manifest} ${outDir}/AndroidManifest.xml && ` +
+			`cp ${classesJar} ${outDir}/classes.jar && ` +
+			`cp ${rTxt} ${outDir}/R.txt && ` +
+			`${config.SoongZipCmd} -jar -o $out -C ${outDir} -D ${outDir} ${resArgs}`,
+		CommandDeps: []string{"${config.SoongZipCmd}"},
+	},
+	"manifest", "classesJar", "rTxt", "resArgs", "outDir")
+
+func BuildAAR(ctx android.ModuleContext, outputFile android.WritablePath,
+	classesJar, manifest, rTxt android.Path, res android.Paths) {
+
+	// TODO(ccross): uniquify and copy resources with dependencies
+
+	deps := android.Paths{manifest, rTxt}
+	classesJarPath := ""
+	if classesJar != nil {
+		deps = append(deps, classesJar)
+		classesJarPath = classesJar.String()
+	}
+
+	ctx.Build(pctx, android.BuildParams{
+		Rule:      buildAAR,
+		Implicits: deps,
+		Output:    outputFile,
+		Args: map[string]string{
+			"manifest":   manifest.String(),
+			"classesJar": classesJarPath,
+			"rTxt":       rTxt.String(),
+			"outDir":     android.PathForModuleOut(ctx, "aar").String(),
+		},
+	})
+}
diff --git a/java/app_test.go b/java/app_test.go
index ba017a1..7a61771 100644
--- a/java/app_test.go
+++ b/java/app_test.go
@@ -59,41 +59,44 @@
 }
 
 func TestApp(t *testing.T) {
-	ctx := testApp(t, `
-		android_app {
-			name: "foo",
-			srcs: ["a.java"],
-		}
-	`)
+	for _, moduleType := range []string{"android_app", "android_library"} {
+		t.Run(moduleType, func(t *testing.T) {
+			ctx := testApp(t, moduleType+` {
+					name: "foo",
+					srcs: ["a.java"],
+				}
+			`)
 
-	foo := ctx.ModuleForTests("foo", "android_common")
+			foo := ctx.ModuleForTests("foo", "android_common")
 
-	expectedLinkImplicits := []string{"AndroidManifest.xml"}
+			expectedLinkImplicits := []string{"AndroidManifest.xml"}
 
-	frameworkRes := ctx.ModuleForTests("framework-res", "android_common")
-	expectedLinkImplicits = append(expectedLinkImplicits,
-		frameworkRes.Output("package-res.apk").Output.String())
+			frameworkRes := ctx.ModuleForTests("framework-res", "android_common")
+			expectedLinkImplicits = append(expectedLinkImplicits,
+				frameworkRes.Output("package-res.apk").Output.String())
 
-	// Test the mapping from input files to compiled output file names
-	compile := foo.Output(compiledResourceFiles[0])
-	if !reflect.DeepEqual(resourceFiles, compile.Inputs.Strings()) {
-		t.Errorf("expected aapt2 compile inputs expected:\n  %#v\n got:\n  %#v",
-			resourceFiles, compile.Inputs.Strings())
-	}
+			// Test the mapping from input files to compiled output file names
+			compile := foo.Output(compiledResourceFiles[0])
+			if !reflect.DeepEqual(resourceFiles, compile.Inputs.Strings()) {
+				t.Errorf("expected aapt2 compile inputs expected:\n  %#v\n got:\n  %#v",
+					resourceFiles, compile.Inputs.Strings())
+			}
 
-	compiledResourceOutputs := compile.Outputs.Strings()
-	sort.Strings(compiledResourceOutputs)
+			compiledResourceOutputs := compile.Outputs.Strings()
+			sort.Strings(compiledResourceOutputs)
 
-	expectedLinkImplicits = append(expectedLinkImplicits, compiledResourceOutputs...)
+			expectedLinkImplicits = append(expectedLinkImplicits, compiledResourceOutputs...)
 
-	list := foo.Output("aapt2/res.list")
-	expectedLinkImplicits = append(expectedLinkImplicits, list.Output.String())
+			list := foo.Output("aapt2/res.list")
+			expectedLinkImplicits = append(expectedLinkImplicits, list.Output.String())
 
-	// Check that the link rule uses
-	res := ctx.ModuleForTests("foo", "android_common").Output("package-res.apk")
-	if !reflect.DeepEqual(expectedLinkImplicits, res.Implicits.Strings()) {
-		t.Errorf("expected aapt2 link implicits expected:\n  %#v\n got:\n  %#v",
-			expectedLinkImplicits, res.Implicits.Strings())
+			// Check that the link rule uses
+			res := ctx.ModuleForTests("foo", "android_common").Output("package-res.apk")
+			if !reflect.DeepEqual(expectedLinkImplicits, res.Implicits.Strings()) {
+				t.Errorf("expected aapt2 link implicits expected:\n  %#v\n got:\n  %#v",
+					expectedLinkImplicits, res.Implicits.Strings())
+			}
+		})
 	}
 }
 
diff --git a/java/java.go b/java/java.go
index 04ce469..bc58df3 100644
--- a/java/java.go
+++ b/java/java.go
@@ -334,6 +334,8 @@
 	module        string
 	systemModules string
 
+	frameworkResModule string
+
 	jar  android.Path
 	aidl android.Path
 }
@@ -423,11 +425,12 @@
 		}
 	}
 
-	toModule := func(m string) sdkDep {
+	toModule := func(m, r string) sdkDep {
 		ret := sdkDep{
-			useModule:     true,
-			module:        m,
-			systemModules: m + "_system_modules",
+			useModule:          true,
+			module:             m,
+			systemModules:      m + "_system_modules",
+			frameworkResModule: r,
 		}
 		if m == "core.current.stubs" {
 			ret.systemModules = "core-system-modules"
@@ -442,16 +445,17 @@
 	switch v {
 	case "":
 		return sdkDep{
-			useDefaultLibs: true,
+			useDefaultLibs:     true,
+			frameworkResModule: "framework-res",
 		}
 	case "current":
-		return toModule("android_stubs_current")
+		return toModule("android_stubs_current", "framework-res")
 	case "system_current":
-		return toModule("android_system_stubs_current")
+		return toModule("android_system_stubs_current", "framework-res")
 	case "test_current":
-		return toModule("android_test_stubs_current")
+		return toModule("android_test_stubs_current", "framework-res")
 	case "core_current":
-		return toModule("core.current.stubs")
+		return toModule("core.current.stubs", "")
 	default:
 		return toFile(v)
 	}
@@ -681,7 +685,10 @@
 		tag := ctx.OtherModuleDependencyTag(module)
 
 		if to, ok := module.(*Library); ok {
-			checkLinkType(ctx, j, to, tag.(dependencyTag))
+			switch tag {
+			case bootClasspathTag, libTag, staticLibTag:
+				checkLinkType(ctx, j, to, tag.(dependencyTag))
+			}
 		}
 		switch dep := module.(type) {
 		case Dependency:
diff --git a/java/resources.go b/java/java_resources.go
similarity index 100%
rename from java/resources.go
rename to java/java_resources.go
diff --git a/java/java_test.go b/java/java_test.go
index a85778f..0e7bb18 100644
--- a/java/java_test.go
+++ b/java/java_test.go
@@ -70,6 +70,7 @@
 
 	ctx := android.NewTestArchContext()
 	ctx.RegisterModuleType("android_app", android.ModuleFactoryAdaptor(AndroidAppFactory))
+	ctx.RegisterModuleType("android_library", android.ModuleFactoryAdaptor(AndroidLibraryFactory))
 	ctx.RegisterModuleType("java_binary_host", android.ModuleFactoryAdaptor(BinaryHostFactory))
 	ctx.RegisterModuleType("java_library", android.ModuleFactoryAdaptor(LibraryFactory(true)))
 	ctx.RegisterModuleType("java_library_host", android.ModuleFactoryAdaptor(LibraryHostFactory))