diff --git a/Android.bp b/Android.bp
index fff17ef..1b68adb 100644
--- a/Android.bp
+++ b/Android.bp
@@ -55,8 +55,10 @@
         "android/mutator.go",
         "android/namespace.go",
         "android/neverallow.go",
+        "android/notices.go",
         "android/onceper.go",
         "android/override_module.go",
+        "android/package.go",
         "android/package_ctx.go",
         "android/path_properties.go",
         "android/paths.go",
@@ -87,6 +89,7 @@
         "android/namespace_test.go",
         "android/neverallow_test.go",
         "android/onceper_test.go",
+        "android/package_test.go",
         "android/path_properties_test.go",
         "android/paths_test.go",
         "android/prebuilt_test.go",
diff --git a/README.md b/README.md
index 8fdce4b..ebbe8bc 100644
--- a/README.md
+++ b/README.md
@@ -133,6 +133,25 @@
 
 This is based on the Bazel package concept.
 
+The `package` module type allows information to be specified about a package. Only a single
+`package` module can be specified per package and in the case where there are multiple `.bp` files
+in the same package directory it is highly recommended that the `package` module (if required) is
+specified in the `Android.bp` file.
+
+Unlike most module type `package` does not have a `name` property. Instead the name is set to the
+name of the package, e.g. if the package is in `top/intermediate/package` then the package name is
+`//top/intermediate/package`.
+
+E.g. The following will set the default visibility for all the modules defined in the package and
+any subpackages that do not set their own default visibility (irrespective of whether they are in
+the same `.bp` file as the `package` module) to be visible to all the subpackages by default.
+
+```
+package {
+    default_visibility: [":__subpackages"]
+}
+```
+
 ### Name resolution
 
 Soong provides the ability for modules in different directories to specify
@@ -191,13 +210,13 @@
 `//independent:evil`)
 * `["//project"]`: This is shorthand for `["//project:__pkg__"]`
 * `[":__subpackages__"]`: This is shorthand for `["//project:__subpackages__"]`
-where `//project` is the module's package. e.g. using `[":__subpackages__"]` in
+where `//project` is the module's package, e.g. using `[":__subpackages__"]` in
 `packages/apps/Settings/Android.bp` is equivalent to
 `//packages/apps/Settings:__subpackages__`.
 * `["//visibility:legacy_public"]`: The default visibility, behaves as
 `//visibility:public` for now. It is an error if it is used in a module.
 
-The visibility rules of `//visibility:public` and `//visibility:private` can not
+The visibility rules of `//visibility:public` and `//visibility:private` cannot
 be combined with any other visibility specifications, except
 `//visibility:public` is allowed to override visibility specifications imported
 through the `defaults` property.
@@ -207,13 +226,22 @@
 say `vendor/google`, instead it must make itself visible to all packages within
 `vendor/` using `//vendor:__subpackages__`.
 
-If a module does not specify the `visibility` property the module is
-`//visibility:legacy_public`. Once the build has been completely switched over to
-soong it is possible that a global refactoring will be done to change this to
-`//visibility:private` at which point all modules that do not currently specify
-a `visibility` property will be updated to have
-`visibility = [//visibility:legacy_public]` added. It will then be the owner's
-responsibility to replace that with a more appropriate visibility.
+If a module does not specify the `visibility` property then it uses the
+`default_visibility` property of the `package` module in the module's package.
+
+If the `default_visibility` property is not set for the module's package then
+it will use the `default_visibility` of its closest ancestor package for which
+a `default_visibility` property is specified.
+
+If no `default_visibility` property can be found then the module uses the
+global default of `//visibility:legacy_public`.
+
+Once the build has been completely switched over to soong it is possible that a
+global refactoring will be done to change this to `//visibility:private` at
+which point all packages that do not currently specify a `default_visibility`
+property will be updated to have
+`default_visibility = [//visibility:legacy_public]` added. It will then be the
+owner's responsibility to replace that with a more appropriate visibility.
 
 ### Formatter
 
diff --git a/android/config.go b/android/config.go
index b0d8b7f..e4012fa 100644
--- a/android/config.go
+++ b/android/config.go
@@ -216,6 +216,7 @@
 			AAPTPreferredConfig:         stringPtr("xhdpi"),
 			AAPTCharacteristics:         stringPtr("nosdcard"),
 			AAPTPrebuiltDPI:             []string{"xhdpi", "xxhdpi"},
+			UncompressPrivAppDex:        boolPtr(true),
 		},
 
 		buildDir:     buildDir,
diff --git a/android/module.go b/android/module.go
index 87e2ca7..43b8763 100644
--- a/android/module.go
+++ b/android/module.go
@@ -202,6 +202,55 @@
 	BuildParamsForTests() []BuildParams
 	RuleParamsForTests() map[blueprint.Rule]blueprint.RuleParams
 	VariablesForTests() map[string]string
+
+	// Get the qualified module id for this module.
+	qualifiedModuleId(ctx BaseModuleContext) qualifiedModuleName
+
+	// Get information about the properties that can contain visibility rules.
+	visibilityProperties() []visibilityProperty
+}
+
+// Qualified id for a module
+type qualifiedModuleName struct {
+	// The package (i.e. directory) in which the module is defined, without trailing /
+	pkg string
+
+	// The name of the module, empty string if package.
+	name string
+}
+
+func (q qualifiedModuleName) String() string {
+	if q.name == "" {
+		return "//" + q.pkg
+	}
+	return "//" + q.pkg + ":" + q.name
+}
+
+func (q qualifiedModuleName) isRootPackage() bool {
+	return q.pkg == "" && q.name == ""
+}
+
+// Get the id for the package containing this module.
+func (q qualifiedModuleName) getContainingPackageId() qualifiedModuleName {
+	pkg := q.pkg
+	if q.name == "" {
+		if pkg == "" {
+			panic(fmt.Errorf("Cannot get containing package id of root package"))
+		}
+
+		index := strings.LastIndex(pkg, "/")
+		if index == -1 {
+			pkg = ""
+		} else {
+			pkg = pkg[:index]
+		}
+	}
+	return newPackageId(pkg)
+}
+
+func newPackageId(pkg string) qualifiedModuleName {
+	// A qualified id for a package module has no name.
+	return qualifiedModuleName{pkg: pkg, name: ""}
 }
 
 type nameProperties struct {
@@ -236,6 +285,20 @@
 	//      //packages/apps/Settings:__subpackages__.
 	//  ["//visibility:legacy_public"]: The default visibility, behaves as //visibility:public
 	//      for now. It is an error if it is used in a module.
+	//
+	// If a module does not specify the `visibility` property then it uses the
+	// `default_visibility` property of the `package` module in the module's package.
+	//
+	// If a module does not specify the `visibility` property then it uses the
+	// `default_visibility` property of the `package` module in the module's package.
+	//
+	// If the `default_visibility` property is not set for the module's package then
+	// it will use the `default_visibility` of its closest ancestor package for which
+	// a `default_visibility` property is specified.
+	//
+	// If no `default_visibility` property can be found then the module uses the
+	// global default of `//visibility:legacy_public`.
+	//
 	// See https://android.googlesource.com/platform/build/soong/+/master/README.md#visibility for
 	// more details.
 	Visibility []string
@@ -571,6 +634,18 @@
 	return m
 }
 
+func (m *ModuleBase) qualifiedModuleId(ctx BaseModuleContext) qualifiedModuleName {
+	return qualifiedModuleName{pkg: ctx.ModuleDir(), name: ctx.ModuleName()}
+}
+
+func (m *ModuleBase) visibilityProperties() []visibilityProperty {
+	return []visibilityProperty{
+		newVisibilityProperty("visibility", func() []string {
+			return m.base().commonProperties.Visibility
+		}),
+	}
+}
+
 func (m *ModuleBase) SetTarget(target Target, multiTargets []Target, primary bool) {
 	m.commonProperties.CompileTarget = target
 	m.commonProperties.CompileMultiTargets = multiTargets
@@ -901,14 +976,6 @@
 	}
 
 	if m.Enabled() {
-		m.module.GenerateAndroidBuildActions(ctx)
-		if ctx.Failed() {
-			return
-		}
-
-		m.installFiles = append(m.installFiles, ctx.installFiles...)
-		m.checkbuildFiles = append(m.checkbuildFiles, ctx.checkbuildFiles...)
-
 		notice := proptools.StringDefault(m.commonProperties.Notice, "NOTICE")
 		if module := SrcIsModule(notice); module != "" {
 			m.noticeFile = ctx.ExpandOptionalSource(&notice, "notice")
@@ -916,6 +983,14 @@
 			noticePath := filepath.Join(ctx.ModuleDir(), notice)
 			m.noticeFile = ExistentPathForSource(ctx, noticePath)
 		}
+
+		m.module.GenerateAndroidBuildActions(ctx)
+		if ctx.Failed() {
+			return
+		}
+
+		m.installFiles = append(m.installFiles, ctx.installFiles...)
+		m.checkbuildFiles = append(m.checkbuildFiles, ctx.checkbuildFiles...)
 	} else if ctx.Config().AllowMissingDependencies() {
 		// If the module is not enabled it will not create any build rules, nothing will call
 		// ctx.GetMissingDependencies(), and blueprint will consider the missing dependencies to be unhandled
diff --git a/android/mutator.go b/android/mutator.go
index 081c2b2..070b420 100644
--- a/android/mutator.go
+++ b/android/mutator.go
@@ -75,6 +75,8 @@
 var preArch = []RegisterMutatorFunc{
 	registerLoadHookMutator,
 	RegisterNamespaceMutator,
+	// Rename package module types.
+	registerPackageRenamer,
 	RegisterPrebuiltsPreArchMutators,
 	registerVisibilityRuleChecker,
 	RegisterDefaultsPreArchMutators,
diff --git a/android/notices.go b/android/notices.go
new file mode 100644
index 0000000..dbb88fc
--- /dev/null
+++ b/android/notices.go
@@ -0,0 +1,87 @@
+// Copyright 2019 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 (
+	"path/filepath"
+
+	"github.com/google/blueprint"
+)
+
+func init() {
+	pctx.SourcePathVariable("merge_notices", "build/soong/scripts/mergenotice.py")
+	pctx.SourcePathVariable("generate_notice", "build/make/tools/generate-notice-files.py")
+
+	pctx.HostBinToolVariable("minigzip", "minigzip")
+}
+
+var (
+	mergeNoticesRule = pctx.AndroidStaticRule("mergeNoticesRule", blueprint.RuleParams{
+		Command:     `${merge_notices} --output $out $in`,
+		CommandDeps: []string{"${merge_notices}"},
+		Description: "merge notice files into $out",
+	})
+
+	generateNoticeRule = pctx.AndroidStaticRule("generateNoticeRule", blueprint.RuleParams{
+		Command: `rm -rf $tmpDir $$(dirname $out) && ` +
+			`mkdir -p $tmpDir $$(dirname $out) && ` +
+			`${generate_notice} --text-output $tmpDir/NOTICE.txt --html-output $tmpDir/NOTICE.html -t "$title" -s $inputDir && ` +
+			`${minigzip} -c $tmpDir/NOTICE.html > $out`,
+		CommandDeps: []string{"${generate_notice}", "${minigzip}"},
+		Description: "produce notice file $out",
+	}, "tmpDir", "title", "inputDir")
+)
+
+func MergeNotices(ctx ModuleContext, mergedNotice WritablePath, noticePaths []Path) {
+	ctx.Build(pctx, BuildParams{
+		Rule:        mergeNoticesRule,
+		Description: "merge notices",
+		Inputs:      noticePaths,
+		Output:      mergedNotice,
+	})
+}
+
+func BuildNoticeOutput(ctx ModuleContext, installPath OutputPath, installFilename string,
+	noticePaths []Path) ModuleOutPath {
+	// Merge all NOTICE files into one.
+	// TODO(jungjw): We should just produce a well-formatted NOTICE.html file in a single pass.
+	//
+	// generate-notice-files.py, which processes the merged NOTICE file, has somewhat strict rules
+	// about input NOTICE file paths.
+	// 1. Their relative paths to the src root become their NOTICE index titles. We want to use
+	// on-device paths as titles, and so output the merged NOTICE file the corresponding location.
+	// 2. They must end with .txt extension. Otherwise, they're ignored.
+	noticeRelPath := InstallPathToOnDevicePath(ctx, installPath.Join(ctx, installFilename+".txt"))
+	mergedNotice := PathForModuleOut(ctx, filepath.Join("NOTICE_FILES/src", noticeRelPath))
+	MergeNotices(ctx, mergedNotice, noticePaths)
+
+	// Transform the merged NOTICE file into a gzipped HTML file.
+	noticeOutput := PathForModuleOut(ctx, "NOTICE", "NOTICE.html.gz")
+	tmpDir := PathForModuleOut(ctx, "NOTICE_tmp")
+	title := "Notices for " + ctx.ModuleName()
+	ctx.Build(pctx, BuildParams{
+		Rule:        generateNoticeRule,
+		Description: "generate notice output",
+		Input:       mergedNotice,
+		Output:      noticeOutput,
+		Args: map[string]string{
+			"tmpDir":   tmpDir.String(),
+			"title":    title,
+			"inputDir": PathForModuleOut(ctx, "NOTICE_FILES/src").String(),
+		},
+	})
+
+	return noticeOutput
+}
diff --git a/android/override_module.go b/android/override_module.go
index 5a57c93..22fb7de 100644
--- a/android/override_module.go
+++ b/android/override_module.go
@@ -95,8 +95,6 @@
 
 // Base module struct for overridable module types
 type OverridableModuleBase struct {
-	ModuleBase
-
 	// List of OverrideModules that override this base module
 	overrides []OverrideModule
 	// Used to parallelize registerOverrideMutator executions. Note that only addOverride locks this
@@ -144,7 +142,7 @@
 	// Adds the base module to the overrides property, if exists, of the overriding module. See the
 	// comment on OverridableModuleBase.overridesProperty for details.
 	if b.overridesProperty != nil {
-		*b.overridesProperty = append(*b.overridesProperty, b.Name())
+		*b.overridesProperty = append(*b.overridesProperty, ctx.ModuleName())
 	}
 	for _, p := range b.overridableProperties {
 		for _, op := range o.getOverridingProperties() {
diff --git a/android/package.go b/android/package.go
new file mode 100644
index 0000000..03f6a1e
--- /dev/null
+++ b/android/package.go
@@ -0,0 +1,194 @@
+// Copyright 2019 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"
+	"sync/atomic"
+
+	"github.com/google/blueprint"
+)
+
+func init() {
+	RegisterModuleType("package", PackageFactory)
+}
+
+// The information maintained about each package.
+type packageInfo struct {
+	// The module from which this information was populated. If `duplicated` = true then this is the
+	// module that has been renamed and must be used to report errors.
+	module *packageModule
+
+	// If true this indicates that there are two package statements in the same package which is not
+	// allowed and will cause the build to fail. This flag is set by packageRenamer and checked in
+	// packageErrorReporter
+	duplicated bool
+}
+
+type packageProperties struct {
+	Name string `blueprint:"mutated"`
+
+	// Specifies the default visibility for all modules defined in this package.
+	Default_visibility []string
+}
+
+type packageModule struct {
+	ModuleBase
+
+	properties  packageProperties
+	packageInfo *packageInfo
+}
+
+func (p *packageModule) GenerateAndroidBuildActions(ModuleContext) {
+	// Nothing to do.
+}
+
+func (p *packageModule) GenerateBuildActions(ctx blueprint.ModuleContext) {
+	// Nothing to do.
+}
+
+func (p *packageModule) qualifiedModuleId(ctx BaseModuleContext) qualifiedModuleName {
+	// Override to create a package id.
+	return newPackageId(ctx.ModuleDir())
+}
+
+// Override to ensure that the default_visibility rules are checked by the visibility module during
+// its checking phase.
+func (p *packageModule) visibilityProperties() []visibilityProperty {
+	return []visibilityProperty{
+		newVisibilityProperty("default_visibility", func() []string {
+			return p.properties.Default_visibility
+		}),
+	}
+}
+
+func (p *packageModule) Name() string {
+	return p.properties.Name
+}
+
+func (p *packageModule) setName(name string) {
+	p.properties.Name = name
+}
+
+// Counter to ensure package modules are created with a unique name within whatever namespace they
+// belong.
+var packageCount uint32 = 0
+
+func PackageFactory() Module {
+	module := &packageModule{}
+
+	// Get a unique if for the package. Has to be done atomically as the creation of the modules are
+	// done in parallel.
+	id := atomic.AddUint32(&packageCount, 1)
+	name := fmt.Sprintf("soong_package_%d", id)
+
+	module.properties.Name = name
+
+	module.AddProperties(&module.properties)
+	return module
+}
+
+// Registers the function that renames the packages.
+func registerPackageRenamer(ctx RegisterMutatorsContext) {
+	ctx.BottomUp("packageRenamer", packageRenamer).Parallel()
+	ctx.BottomUp("packageErrorReporter", packageErrorReporter).Parallel()
+}
+
+// Renames the package to match the package directory.
+//
+// This also creates a PackageInfo object for each package and uses that to detect and remember
+// duplicates for later error reporting.
+func packageRenamer(ctx BottomUpMutatorContext) {
+	m, ok := ctx.Module().(*packageModule)
+	if !ok {
+		return
+	}
+
+	packageName := "//" + ctx.ModuleDir()
+
+	pi := newPackageInfo(ctx, packageName, m)
+	if pi.module != m {
+		// Remember that the package was duplicated but do not rename as that will cause an error to
+		// be logged with the generated name. Similarly, reporting the error here will use the generated
+		// name as renames are only processed after this phase.
+		pi.duplicated = true
+	} else {
+		// This is the first package module in this package so rename it to match the package name.
+		m.setName(packageName)
+		ctx.Rename(packageName)
+
+		// Store a package info reference in the module.
+		m.packageInfo = pi
+	}
+}
+
+// Logs any deferred errors.
+func packageErrorReporter(ctx BottomUpMutatorContext) {
+	m, ok := ctx.Module().(*packageModule)
+	if !ok {
+		return
+	}
+
+	packageDir := ctx.ModuleDir()
+	packageName := "//" + packageDir
+
+	// Get the PackageInfo for the package. Should have been populated in the packageRenamer phase.
+	pi := findPackageInfo(ctx, packageName)
+	if pi == nil {
+		ctx.ModuleErrorf("internal error, expected package info to be present for package '%s'",
+			packageName)
+		return
+	}
+
+	if pi.module != m {
+		// The package module has been duplicated but this is not the module that has been renamed so
+		// ignore it. An error will be logged for the renamed module which will ensure that the error
+		// message uses the correct name.
+		return
+	}
+
+	// Check to see whether there are duplicate package modules in the package.
+	if pi.duplicated {
+		ctx.ModuleErrorf("package {...} specified multiple times")
+		return
+	}
+}
+
+type defaultPackageInfoKey string
+
+func newPackageInfo(
+	ctx BaseModuleContext, packageName string, module *packageModule) *packageInfo {
+	key := NewCustomOnceKey(defaultPackageInfoKey(packageName))
+
+	return ctx.Config().Once(key, func() interface{} {
+		return &packageInfo{module: module}
+	}).(*packageInfo)
+}
+
+// Get the PackageInfo for the package name (starts with //, no trailing /), is nil if no package
+// module type was specified.
+func findPackageInfo(ctx BaseModuleContext, packageName string) *packageInfo {
+	key := NewCustomOnceKey(defaultPackageInfoKey(packageName))
+
+	pi := ctx.Config().Once(key, func() interface{} {
+		return nil
+	})
+
+	if pi == nil {
+		return nil
+	} else {
+		return pi.(*packageInfo)
+	}
+}
diff --git a/android/package_test.go b/android/package_test.go
new file mode 100644
index 0000000..f1f47ac
--- /dev/null
+++ b/android/package_test.go
@@ -0,0 +1,111 @@
+package android
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+)
+
+var packageTests = []struct {
+	name           string
+	fs             map[string][]byte
+	expectedErrors []string
+}{
+	// Package default_visibility handling is tested in visibility_test.go
+	{
+		name: "package must not accept visibility and name properties",
+		fs: map[string][]byte{
+			"top/Blueprints": []byte(`
+				package {
+					name: "package",
+					visibility: ["//visibility:private"],
+				}`),
+		},
+		expectedErrors: []string{
+			`top/Blueprints:3:10: mutated field name cannot be set in a Blueprint file`,
+			`top/Blueprints:4:16: unrecognized property "visibility"`,
+		},
+	},
+	{
+		name: "multiple packages in separate directories",
+		fs: map[string][]byte{
+			"top/Blueprints": []byte(`
+				package {
+				}`),
+			"other/Blueprints": []byte(`
+				package {
+				}`),
+			"other/nested/Blueprints": []byte(`
+				package {
+				}`),
+		},
+	},
+	{
+		name: "package must not be specified more than once per package",
+		fs: map[string][]byte{
+			"top/Blueprints": []byte(`
+				package {
+					default_visibility: ["//visibility:private"],
+				}
+
+        package {
+				}`),
+		},
+		expectedErrors: []string{
+			`module "//top": package {...} specified multiple times`,
+		},
+	},
+}
+
+func TestPackage(t *testing.T) {
+	buildDir, err := ioutil.TempDir("", "soong_package_test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(buildDir)
+
+	for _, test := range packageTests {
+		t.Run(test.name, func(t *testing.T) {
+			_, errs := testPackage(buildDir, test.fs)
+
+			expectedErrors := test.expectedErrors
+			if expectedErrors == nil {
+				FailIfErrored(t, errs)
+			} else {
+				for _, expectedError := range expectedErrors {
+					FailIfNoMatchingErrors(t, expectedError, errs)
+				}
+				if len(errs) > len(expectedErrors) {
+					t.Errorf("additional errors found, expected %d, found %d", len(expectedErrors), len(errs))
+					for i, expectedError := range expectedErrors {
+						t.Errorf("expectedErrors[%d] = %s", i, expectedError)
+					}
+					for i, err := range errs {
+						t.Errorf("errs[%d] = %s", i, err)
+					}
+				}
+			}
+		})
+	}
+}
+
+func testPackage(buildDir string, fs map[string][]byte) (*TestContext, []error) {
+
+	// Create a new config per test as visibility information is stored in the config.
+	config := TestArchConfig(buildDir, nil)
+
+	ctx := NewTestArchContext()
+	ctx.RegisterModuleType("package", ModuleFactoryAdaptor(PackageFactory))
+	ctx.PreArchMutators(registerPackageRenamer)
+	ctx.Register()
+
+	ctx.MockFileSystem(fs)
+
+	_, errs := ctx.ParseBlueprintsFiles(".")
+	if len(errs) > 0 {
+		return ctx, errs
+	}
+
+	_, errs = ctx.PrepareBuildActions(config)
+	return ctx, errs
+}
diff --git a/android/visibility.go b/android/visibility.go
index c7ef1da..94af343 100644
--- a/android/visibility.go
+++ b/android/visibility.go
@@ -23,14 +23,21 @@
 
 // Enforces visibility rules between modules.
 //
-// Two stage process:
-// * First stage works bottom up to extract visibility information from the modules, parse it,
+// Multi stage process:
+// * First stage works bottom up, before defaults expansion, to check the syntax of the visibility
+//   rules that have been specified.
+//
+// * Second stage works bottom up to extract the package info for each package and store them in a
+//   map by package name. See package.go for functionality for this.
+//
+// * Third stage works bottom up to extract visibility information from the modules, parse it,
 //   create visibilityRule structures and store them in a map keyed by the module's
 //   qualifiedModuleName instance, i.e. //<pkg>:<name>. The map is stored in the context rather
 //   than a global variable for testing. Each test has its own Config so they do not share a map
-//   and so can be run in parallel.
+//   and so can be run in parallel. If a module has no visibility specified then it uses the
+//   default package visibility if specified.
 //
-// * Second stage works top down and iterates over all the deps for each module. If the dep is in
+// * Fourth stage works top down and iterates over all the deps for each module. If the dep is in
 //   the same package then it is automatically visible. Otherwise, for each dep it first extracts
 //   its visibilityRule from the config map. If one could not be found then it assumes that it is
 //   publicly visible. Otherwise, it calls the visibility rule to check that the module can see
@@ -48,19 +55,6 @@
 
 var visibilityRuleRegexp = regexp.MustCompile(visibilityRulePattern)
 
-// Qualified id for a module
-type qualifiedModuleName struct {
-	// The package (i.e. directory) in which the module is defined, without trailing /
-	pkg string
-
-	// The name of the module.
-	name string
-}
-
-func (q qualifiedModuleName) String() string {
-	return fmt.Sprintf("//%s:%s", q.pkg, q.name)
-}
-
 // A visibility rule is associated with a module and determines which other modules it is visible
 // to, i.e. which other modules can depend on the rule's module.
 type visibilityRule interface {
@@ -71,6 +65,32 @@
 	String() string
 }
 
+// Describes the properties provided by a module that contain visibility rules.
+type visibilityPropertyImpl struct {
+	name          string
+	stringsGetter func() []string
+}
+
+type visibilityProperty interface {
+	getName() string
+	getStrings() []string
+}
+
+func newVisibilityProperty(name string, stringsGetter func() []string) visibilityProperty {
+	return visibilityPropertyImpl{
+		name:          name,
+		stringsGetter: stringsGetter,
+	}
+}
+
+func (p visibilityPropertyImpl) getName() string {
+	return p.name
+}
+
+func (p visibilityPropertyImpl) getStrings() []string {
+	return p.stringsGetter()
+}
+
 // A compositeRule is a visibility rule composed from a list of atomic visibility rules.
 //
 // The list corresponds to the list of strings in the visibility property after defaults expansion.
@@ -96,9 +116,9 @@
 	return false
 }
 
-func (r compositeRule) String() string {
-	s := make([]string, 0, len(r))
-	for _, r := range r {
+func (c compositeRule) String() string {
+	s := make([]string, 0, len(c))
+	for _, r := range c {
 		s = append(s, r.String())
 	}
 
@@ -173,9 +193,12 @@
 	ctx.BottomUp("visibilityRuleChecker", visibilityRuleChecker).Parallel()
 }
 
+// Registers the function that gathers the visibility rules for each module.
+//
 // Visibility is not dependent on arch so this must be registered before the arch phase to avoid
 // having to process multiple variants for each module. This goes after defaults expansion to gather
-// the complete visibility lists from flat lists.
+// the complete visibility lists from flat lists and after the package info is gathered to ensure
+// that default_visibility is available.
 func registerVisibilityRuleGatherer(ctx RegisterMutatorsContext) {
 	ctx.BottomUp("visibilityRuleGatherer", visibilityRuleGatherer).Parallel()
 }
@@ -193,33 +216,36 @@
 		for _, props := range d.properties() {
 			if cp, ok := props.(*commonProperties); ok {
 				if visibility := cp.Visibility; visibility != nil {
-					checkRules(ctx, qualified.pkg, visibility)
+					checkRules(ctx, qualified.pkg, "visibility", visibility)
 				}
 			}
 		}
 	} else if m, ok := ctx.Module().(Module); ok {
-		if visibility := m.base().commonProperties.Visibility; visibility != nil {
-			checkRules(ctx, qualified.pkg, visibility)
+		visibilityProperties := m.visibilityProperties()
+		for _, p := range visibilityProperties {
+			if visibility := p.getStrings(); visibility != nil {
+				checkRules(ctx, qualified.pkg, p.getName(), visibility)
+			}
 		}
 	}
 }
 
-func checkRules(ctx BottomUpMutatorContext, currentPkg string, visibility []string) {
+func checkRules(ctx BaseModuleContext, currentPkg, property string, visibility []string) {
 	ruleCount := len(visibility)
 	if ruleCount == 0 {
 		// This prohibits an empty list as its meaning is unclear, e.g. it could mean no visibility and
 		// it could mean public visibility. Requiring at least one rule makes the owner's intent
 		// clearer.
-		ctx.PropertyErrorf("visibility", "must contain at least one visibility rule")
+		ctx.PropertyErrorf(property, "must contain at least one visibility rule")
 		return
 	}
 
 	for _, v := range visibility {
-		ok, pkg, name := splitRule(ctx, v, currentPkg)
+		ok, pkg, name := splitRule(v, currentPkg)
 		if !ok {
 			// Visibility rule is invalid so ignore it. Keep going rather than aborting straight away to
 			// ensure all the rules on this module are checked.
-			ctx.PropertyErrorf("visibility",
+			ctx.PropertyErrorf(property,
 				"invalid visibility pattern %q must match"+
 					" //<package>:<module>, //<package> or :<module>",
 				v)
@@ -230,14 +256,14 @@
 			switch name {
 			case "private", "public":
 			case "legacy_public":
-				ctx.PropertyErrorf("visibility", "//visibility:legacy_public must not be used")
+				ctx.PropertyErrorf(property, "//visibility:legacy_public must not be used")
 				continue
 			default:
-				ctx.PropertyErrorf("visibility", "unrecognized visibility rule %q", v)
+				ctx.PropertyErrorf(property, "unrecognized visibility rule %q", v)
 				continue
 			}
 			if ruleCount != 1 {
-				ctx.PropertyErrorf("visibility", "cannot mix %q with any other visibility rules", v)
+				ctx.PropertyErrorf(property, "cannot mix %q with any other visibility rules", v)
 				continue
 			}
 		}
@@ -246,7 +272,7 @@
 		// restrictions on the rules.
 		if !isAncestor("vendor", currentPkg) {
 			if !isAllowedFromOutsideVendor(pkg, name) {
-				ctx.PropertyErrorf("visibility",
+				ctx.PropertyErrorf(property,
 					"%q is not allowed. Packages outside //vendor cannot make themselves visible to specific"+
 						" targets within //vendor, they can only use //vendor:__subpackages__.", v)
 				continue
@@ -265,23 +291,27 @@
 		return
 	}
 
-	qualified := createQualifiedModuleName(ctx)
+	qualifiedModuleId := m.qualifiedModuleId(ctx)
+	currentPkg := qualifiedModuleId.pkg
 
-	visibility := m.base().commonProperties.Visibility
-	if visibility != nil {
-		rule := parseRules(ctx, qualified.pkg, visibility)
-		if rule != nil {
-			moduleToVisibilityRuleMap(ctx).Store(qualified, rule)
+	// Parse all the properties into rules and store them.
+	visibilityProperties := m.visibilityProperties()
+	for _, p := range visibilityProperties {
+		if visibility := p.getStrings(); visibility != nil {
+			rule := parseRules(ctx, currentPkg, visibility)
+			if rule != nil {
+				moduleToVisibilityRuleMap(ctx).Store(qualifiedModuleId, rule)
+			}
 		}
 	}
 }
 
-func parseRules(ctx BottomUpMutatorContext, currentPkg string, visibility []string) compositeRule {
+func parseRules(ctx BaseModuleContext, currentPkg string, visibility []string) compositeRule {
 	rules := make(compositeRule, 0, len(visibility))
 	hasPrivateRule := false
 	hasNonPrivateRule := false
 	for _, v := range visibility {
-		ok, pkg, name := splitRule(ctx, v, currentPkg)
+		ok, pkg, name := splitRule(v, currentPkg)
 		if !ok {
 			continue
 		}
@@ -336,7 +366,7 @@
 	return !isAncestor("vendor", pkg)
 }
 
-func splitRule(ctx BaseModuleContext, ruleExpression string, currentPkg string) (bool, string, string) {
+func splitRule(ruleExpression string, currentPkg string) (bool, string, string) {
 	// Make sure that the rule is of the correct format.
 	matches := visibilityRuleRegexp.FindStringSubmatch(ruleExpression)
 	if ruleExpression == "" || matches == nil {
@@ -378,11 +408,15 @@
 			return
 		}
 
-		rule, ok := moduleToVisibilityRule.Load(depQualified)
+		value, ok := moduleToVisibilityRule.Load(depQualified)
+		var rule compositeRule
 		if ok {
-			if !rule.(compositeRule).matches(qualified) {
-				ctx.ModuleErrorf("depends on %s which is not visible to this module", depQualified)
-			}
+			rule = value.(compositeRule)
+		} else {
+			rule = packageDefaultVisibility(ctx, depQualified)
+		}
+		if rule != nil && !rule.matches(qualified) {
+			ctx.ModuleErrorf("depends on %s which is not visible to this module", depQualified)
 		}
 	})
 }
@@ -393,3 +427,20 @@
 	qualified := qualifiedModuleName{dir, moduleName}
 	return qualified
 }
+
+func packageDefaultVisibility(ctx BaseModuleContext, moduleId qualifiedModuleName) compositeRule {
+	moduleToVisibilityRule := moduleToVisibilityRuleMap(ctx)
+	packageQualifiedId := moduleId.getContainingPackageId()
+	for {
+		value, ok := moduleToVisibilityRule.Load(packageQualifiedId)
+		if ok {
+			return value.(compositeRule)
+		}
+
+		if packageQualifiedId.isRootPackage() {
+			return nil
+		}
+
+		packageQualifiedId = packageQualifiedId.getContainingPackageId()
+	}
+}
diff --git a/android/visibility_test.go b/android/visibility_test.go
index 1a51495..af6acf4 100644
--- a/android/visibility_test.go
+++ b/android/visibility_test.go
@@ -658,6 +658,167 @@
 				` visible to this module`,
 		},
 	},
+	// Package default_visibility tests
+	{
+		name: "package default_visibility property is checked",
+		fs: map[string][]byte{
+			"top/Blueprints": []byte(`
+				package {
+					default_visibility: ["//visibility:invalid"],
+				}`),
+		},
+		expectedErrors: []string{`default_visibility: unrecognized visibility rule "//visibility:invalid"`},
+	},
+	{
+		// This test relies on the default visibility being legacy_public.
+		name: "package default_visibility property used when no visibility specified",
+		fs: map[string][]byte{
+			"top/Blueprints": []byte(`
+				package {
+					default_visibility: ["//visibility:private"],
+				}
+
+				mock_library {
+					name: "libexample",
+				}`),
+			"outsider/Blueprints": []byte(`
+				mock_library {
+					name: "liboutsider",
+					deps: ["libexample"],
+				}`),
+		},
+		expectedErrors: []string{
+			`module "liboutsider" variant "android_common": depends on //top:libexample which is not` +
+				` visible to this module`,
+		},
+	},
+	{
+		name: "package default_visibility public does not override visibility private",
+		fs: map[string][]byte{
+			"top/Blueprints": []byte(`
+				package {
+					default_visibility: ["//visibility:public"],
+				}
+
+				mock_library {
+					name: "libexample",
+					visibility: ["//visibility:private"],
+				}`),
+			"outsider/Blueprints": []byte(`
+				mock_library {
+					name: "liboutsider",
+					deps: ["libexample"],
+				}`),
+		},
+		expectedErrors: []string{
+			`module "liboutsider" variant "android_common": depends on //top:libexample which is not` +
+				` visible to this module`,
+		},
+	},
+	{
+		name: "package default_visibility private does not override visibility public",
+		fs: map[string][]byte{
+			"top/Blueprints": []byte(`
+				package {
+					default_visibility: ["//visibility:private"],
+				}
+
+				mock_library {
+					name: "libexample",
+					visibility: ["//visibility:public"],
+				}`),
+			"outsider/Blueprints": []byte(`
+				mock_library {
+					name: "liboutsider",
+					deps: ["libexample"],
+				}`),
+		},
+	},
+	{
+		name: "package default_visibility :__subpackages__",
+		fs: map[string][]byte{
+			"top/Blueprints": []byte(`
+				package {
+					default_visibility: [":__subpackages__"],
+				}
+
+				mock_library {
+					name: "libexample",
+				}`),
+			"top/nested/Blueprints": []byte(`
+				mock_library {
+					name: "libnested",
+					deps: ["libexample"],
+				}`),
+			"outsider/Blueprints": []byte(`
+				mock_library {
+					name: "liboutsider",
+					deps: ["libexample"],
+				}`),
+		},
+		expectedErrors: []string{
+			`module "liboutsider" variant "android_common": depends on //top:libexample which is not` +
+				` visible to this module`,
+		},
+	},
+	{
+		name: "package default_visibility inherited to subpackages",
+		fs: map[string][]byte{
+			"top/Blueprints": []byte(`
+				package {
+					default_visibility: ["//outsider"],
+				}
+
+				mock_library {
+					name: "libexample",
+          visibility: [":__subpackages__"],
+				}`),
+			"top/nested/Blueprints": []byte(`
+				mock_library {
+					name: "libnested",
+					deps: ["libexample"],
+				}`),
+			"outsider/Blueprints": []byte(`
+				mock_library {
+					name: "liboutsider",
+					deps: ["libexample", "libnested"],
+				}`),
+		},
+		expectedErrors: []string{
+			`module "liboutsider" variant "android_common": depends on //top:libexample which is not` +
+				` visible to this module`,
+		},
+	},
+	{
+		name: "package default_visibility inherited to subpackages",
+		fs: map[string][]byte{
+			"top/Blueprints": []byte(`
+				package {
+					default_visibility: ["//visibility:private"],
+				}`),
+			"top/nested/Blueprints": []byte(`
+				package {
+					default_visibility: ["//outsider"],
+				}
+
+				mock_library {
+					name: "libnested",
+				}`),
+			"top/other/Blueprints": []byte(`
+				mock_library {
+					name: "libother",
+				}`),
+			"outsider/Blueprints": []byte(`
+				mock_library {
+					name: "liboutsider",
+					deps: ["libother", "libnested"],
+				}`),
+		},
+		expectedErrors: []string{
+			`module "liboutsider" variant "android_common": depends on //top/other:libother which is` +
+				` not visible to this module`,
+		},
+	},
 }
 
 func TestVisibility(t *testing.T) {
@@ -692,8 +853,10 @@
 	config := TestArchConfig(buildDir, nil)
 
 	ctx := NewTestArchContext()
+	ctx.RegisterModuleType("package", ModuleFactoryAdaptor(PackageFactory))
 	ctx.RegisterModuleType("mock_library", ModuleFactoryAdaptor(newMockLibraryModule))
 	ctx.RegisterModuleType("mock_defaults", ModuleFactoryAdaptor(defaultsFactory))
+	ctx.PreArchMutators(registerPackageRenamer)
 	ctx.PreArchMutators(registerVisibilityRuleChecker)
 	ctx.PreArchMutators(RegisterDefaultsPreArchMutators)
 	ctx.PreArchMutators(registerVisibilityRuleGatherer)
diff --git a/apex/apex.go b/apex/apex.go
index 84e5497..a77e295 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -90,12 +90,6 @@
 		CommandDeps: []string{"${zip2zip}"},
 		Description: "app bundle",
 	}, "abi")
-
-	apexMergeNoticeRule = pctx.StaticRule("apexMergeNoticeRule", blueprint.RuleParams{
-		Command:     `${mergenotice} --output $out $inputs`,
-		CommandDeps: []string{"${mergenotice}"},
-		Description: "merge notice files into $out",
-	}, "inputs")
 )
 
 var imageApexSuffix = ".apex"
@@ -144,8 +138,6 @@
 	pctx.HostBinToolVariable("zip2zip", "zip2zip")
 	pctx.HostBinToolVariable("zipalign", "zipalign")
 
-	pctx.SourcePathVariable("mergenotice", "build/soong/scripts/mergenotice.py")
-
 	android.RegisterModuleType("apex", apexBundleFactory)
 	android.RegisterModuleType("apex_test", testApexBundleFactory)
 	android.RegisterModuleType("apex_defaults", defaultsFactory)
@@ -153,7 +145,7 @@
 
 	android.PostDepsMutators(func(ctx android.RegisterMutatorsContext) {
 		ctx.TopDown("apex_deps", apexDepsMutator)
-		ctx.BottomUp("apex", apexMutator)
+		ctx.BottomUp("apex", apexMutator).Parallel()
 	})
 }
 
@@ -402,8 +394,6 @@
 	container_certificate_file android.Path
 	container_private_key_file android.Path
 
-	mergedNoticeFile android.WritablePath
-
 	// list of files to be included in this apex
 	filesInfo []apexFile
 
@@ -836,8 +826,6 @@
 	a.installDir = android.PathForModuleInstall(ctx, "apex")
 	a.filesInfo = filesInfo
 
-	a.buildNoticeFile(ctx)
-
 	if a.apexTypes.zip() {
 		a.buildUnflattenedApex(ctx, zipApex)
 	}
@@ -851,35 +839,27 @@
 	}
 }
 
-func (a *apexBundle) buildNoticeFile(ctx android.ModuleContext) {
+func (a *apexBundle) buildNoticeFile(ctx android.ModuleContext, apexFileName string) android.OptionalPath {
 	noticeFiles := []android.Path{}
-	noticeFilesString := []string{}
 	for _, f := range a.filesInfo {
 		if f.module != nil {
 			notice := f.module.NoticeFile()
 			if notice.Valid() {
 				noticeFiles = append(noticeFiles, notice.Path())
-				noticeFilesString = append(noticeFilesString, notice.Path().String())
 			}
 		}
 	}
 	// append the notice file specified in the apex module itself
 	if a.NoticeFile().Valid() {
 		noticeFiles = append(noticeFiles, a.NoticeFile().Path())
-		noticeFilesString = append(noticeFilesString, a.NoticeFile().Path().String())
 	}
 
-	if len(noticeFiles) > 0 {
-		a.mergedNoticeFile = android.PathForModuleOut(ctx, "NOTICE")
-		ctx.Build(pctx, android.BuildParams{
-			Rule:   apexMergeNoticeRule,
-			Inputs: noticeFiles,
-			Output: a.mergedNoticeFile,
-			Args: map[string]string{
-				"inputs": strings.Join(noticeFilesString, " "),
-			},
-		})
+	if len(noticeFiles) == 0 {
+		return android.OptionalPath{}
 	}
+
+	return android.OptionalPathForPath(
+		android.BuildNoticeOutput(ctx, a.installDir, apexFileName, android.FirstUniquePaths(noticeFiles)))
 }
 
 func (a *apexBundle) buildUnflattenedApex(ctx android.ModuleContext, apexType apexPackaging) {
@@ -1004,6 +984,13 @@
 		}
 		optFlags = append(optFlags, "--target_sdk_version "+targetSdkVersion)
 
+		noticeFile := a.buildNoticeFile(ctx, ctx.ModuleName()+suffix)
+		if noticeFile.Valid() {
+			// If there's a NOTICE file, embed it as an asset file in the APEX.
+			implicitInputs = append(implicitInputs, noticeFile.Path())
+			optFlags = append(optFlags, "--assets_dir "+filepath.Dir(noticeFile.String()))
+		}
+
 		ctx.Build(pctx, android.BuildParams{
 			Rule:        apexRule,
 			Implicits:   implicitInputs,
@@ -1250,9 +1237,6 @@
 				fmt.Fprintln(w, "LOCAL_MODULE_PATH :=", filepath.Join("$(OUT_DIR)", a.installDir.RelPathString()))
 				fmt.Fprintln(w, "LOCAL_MODULE_STEM :=", name+apexType.suffix())
 				fmt.Fprintln(w, "LOCAL_UNINSTALLABLE_MODULE :=", !a.installable())
-				if a.installable() && a.mergedNoticeFile != nil {
-					fmt.Fprintln(w, "LOCAL_NOTICE_FILE :=", a.mergedNoticeFile.String())
-				}
 				if len(moduleNames) > 0 {
 					fmt.Fprintln(w, "LOCAL_REQUIRED_MODULES +=", strings.Join(moduleNames, " "))
 				}
diff --git a/apex/apex_test.go b/apex/apex_test.go
index f71abd7..2e44db7 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -27,9 +27,15 @@
 	"android/soong/java"
 )
 
+var buildDir string
+
 func testApex(t *testing.T, bp string) *android.TestContext {
-	config, buildDir := setup(t)
-	defer teardown(buildDir)
+	config := android.TestArchConfig(buildDir, nil)
+	config.TestProductVariables.DeviceVndkVersion = proptools.StringPtr("current")
+	config.TestProductVariables.DefaultAppCertificate = proptools.StringPtr("vendor/foo/devkeys/test")
+	config.TestProductVariables.CertificateOverrides = []string{"myapex_keytest:myapex.certificate.override"}
+	config.TestProductVariables.Platform_sdk_codename = proptools.StringPtr("Q")
+	config.TestProductVariables.Platform_sdk_final = proptools.BoolPtr(false)
 
 	ctx := android.NewTestArchContext()
 	ctx.RegisterModuleType("apex", android.ModuleFactoryAdaptor(apexBundleFactory))
@@ -188,22 +194,15 @@
 	return ctx
 }
 
-func setup(t *testing.T) (config android.Config, buildDir string) {
-	buildDir, err := ioutil.TempDir("", "soong_apex_test")
+func setUp() {
+	var err error
+	buildDir, err = ioutil.TempDir("", "soong_apex_test")
 	if err != nil {
-		t.Fatal(err)
+		panic(err)
 	}
-
-	config = android.TestArchConfig(buildDir, nil)
-	config.TestProductVariables.DeviceVndkVersion = proptools.StringPtr("current")
-	config.TestProductVariables.DefaultAppCertificate = proptools.StringPtr("vendor/foo/devkeys/test")
-	config.TestProductVariables.CertificateOverrides = []string{"myapex_keytest:myapex.certificate.override"}
-	config.TestProductVariables.Platform_sdk_codename = proptools.StringPtr("Q")
-	config.TestProductVariables.Platform_sdk_final = proptools.BoolPtr(false)
-	return
 }
 
-func teardown(buildDir string) {
+func tearDown() {
 	os.RemoveAll(buildDir)
 }
 
@@ -310,6 +309,8 @@
 
 	optFlags := apexRule.Args["opt_flags"]
 	ensureContains(t, optFlags, "--pubkey vendor/foo/devkeys/testkey.avbpubkey")
+	// Ensure that the NOTICE output is being packaged as an asset.
+	ensureContains(t, optFlags, "--assets_dir "+buildDir+"/.intermediates/myapex/android_common_myapex/NOTICE")
 
 	copyCmds := apexRule.Args["copy_commands"]
 
@@ -347,10 +348,10 @@
 		t.Errorf("Could not find all expected symlinks! foo: %t, foo_link_64: %t. Command was %s", found_foo, found_foo_link_64, copyCmds)
 	}
 
-	apexMergeNoticeRule := ctx.ModuleForTests("myapex", "android_common_myapex").Rule("apexMergeNoticeRule")
-	noticeInputs := strings.Split(apexMergeNoticeRule.Args["inputs"], " ")
-	if len(noticeInputs) != 3 {
-		t.Errorf("number of input notice files: expected = 3, actual = %d", len(noticeInputs))
+	mergeNoticesRule := ctx.ModuleForTests("myapex", "android_common_myapex").Rule("mergeNoticesRule")
+	noticeInputs := mergeNoticesRule.Inputs.Strings()
+	if len(noticeInputs) != 2 {
+		t.Errorf("number of input notice files: expected = 2, actual = %q", len(noticeInputs))
 	}
 	ensureListContains(t, noticeInputs, "NOTICE")
 	ensureListContains(t, noticeInputs, "custom_notice")
@@ -1283,3 +1284,14 @@
 		t.Errorf("installFilename invalid. expected: %q, actual: %q", expected, p.installFilename)
 	}
 }
+
+func TestMain(m *testing.M) {
+	run := func() int {
+		setUp()
+		defer tearDown()
+
+		return m.Run()
+	}
+
+	os.Exit(run())
+}
diff --git a/cc/builder.go b/cc/builder.go
index 1e12361..ee40736 100644
--- a/cc/builder.go
+++ b/cc/builder.go
@@ -416,7 +416,7 @@
 			ccCmd = "clang"
 			moduleCflags = cflags
 			moduleToolingCflags = toolingCflags
-		case ".cpp", ".cc", ".mm":
+		case ".cpp", ".cc", ".cxx", ".mm":
 			ccCmd = "clang++"
 			moduleCflags = cppflags
 			moduleToolingCflags = toolingCppflags
diff --git a/cc/cc.go b/cc/cc.go
index 53ec899..6215067 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -65,7 +65,7 @@
 		ctx.TopDown("tsan_deps", sanitizerDepsMutator(tsan))
 		ctx.BottomUp("tsan", sanitizerMutator(tsan)).Parallel()
 
-		ctx.TopDown("sanitize_runtime_deps", sanitizerRuntimeDepsMutator)
+		ctx.TopDown("sanitize_runtime_deps", sanitizerRuntimeDepsMutator).Parallel()
 		ctx.BottomUp("sanitize_runtime", sanitizerRuntimeMutator).Parallel()
 
 		ctx.BottomUp("coverage", coverageMutator).Parallel()
@@ -778,6 +778,10 @@
 		// APEX variants do not need ABI dumps.
 		return false
 	}
+	if ctx.isStubs() {
+		// Stubs do not need ABI dumps.
+		return false
+	}
 	if ctx.isNdk() {
 		return true
 	}
diff --git a/cc/compdb.go b/cc/compdb.go
index 1102651..ecc67b8 100644
--- a/cc/compdb.go
+++ b/cc/compdb.go
@@ -141,7 +141,7 @@
 		isAsm = false
 		isCpp = false
 		clangPath = ccPath
-	case ".cpp", ".cc", ".mm":
+	case ".cpp", ".cc", ".cxx", ".mm":
 		isAsm = false
 		isCpp = true
 		clangPath = cxxPath
diff --git a/cc/config/x86_64_device.go b/cc/config/x86_64_device.go
index 0f0420f..d9c96df 100644
--- a/cc/config/x86_64_device.go
+++ b/cc/config/x86_64_device.go
@@ -67,10 +67,16 @@
 		"sse4":   []string{"-msse4"},
 		"sse4_1": []string{"-msse4.1"},
 		"sse4_2": []string{"-msse4.2"},
+
+		// Not all cases there is performance gain by enabling -mavx -mavx2
+		// flags so these flags are not enabled by default.
+		// if there is performance gain in individual library components,
+		// the compiler flags can be set in corresponding bp files.
+		// "avx":    []string{"-mavx"},
+		// "avx2":   []string{"-mavx2"},
+		// "avx512": []string{"-mavx512"}
+
 		"popcnt": []string{"-mpopcnt"},
-		"avx":    []string{"-mavx"},
-		"avx2":   []string{"-mavx2"},
-		"avx512": []string{"-mavx512"},
 		"aes_ni": []string{"-maes"},
 	}
 )
diff --git a/cc/config/x86_device.go b/cc/config/x86_device.go
index 500014e..6504758 100644
--- a/cc/config/x86_device.go
+++ b/cc/config/x86_device.go
@@ -86,8 +86,15 @@
 		"sse4":   []string{"-msse4"},
 		"sse4_1": []string{"-msse4.1"},
 		"sse4_2": []string{"-msse4.2"},
-		"avx":    []string{"-mavx"},
-		"avx2":   []string{"-mavx2"},
+
+		// Not all cases there is performance gain by enabling -mavx -mavx2
+		// flags so these flags are not enabled by default.
+		// if there is performance gain in individual library components,
+		// the compiler flags can be set in corresponding bp files.
+		// "avx":    []string{"-mavx"},
+		// "avx2":   []string{"-mavx2"},
+		// "avx512": []string{"-mavx512"}
+
 		"aes_ni": []string{"-maes"},
 	}
 )
diff --git a/cc/gen.go b/cc/gen.go
index 1d30dab..7516b28 100644
--- a/cc/gen.go
+++ b/cc/gen.go
@@ -25,6 +25,7 @@
 
 func init() {
 	pctx.SourcePathVariable("lexCmd", "prebuilts/build-tools/${config.HostPrebuiltTag}/bin/flex")
+	pctx.SourcePathVariable("m4Cmd", "prebuilts/build-tools/${config.HostPrebuiltTag}/bin/m4")
 
 	pctx.HostBinToolVariable("aidlCmd", "aidl-cpp")
 	pctx.HostBinToolVariable("syspropCmd", "sysprop_cpp")
@@ -33,8 +34,8 @@
 var (
 	lex = pctx.AndroidStaticRule("lex",
 		blueprint.RuleParams{
-			Command:     "$lexCmd -o$out $in",
-			CommandDeps: []string{"$lexCmd"},
+			Command:     "M4=$m4Cmd $lexCmd -o$out $in",
+			CommandDeps: []string{"$lexCmd", "$m4Cmd"},
 		})
 
 	sysprop = pctx.AndroidStaticRule("sysprop",
@@ -97,6 +98,7 @@
 	}
 
 	cmd.Text("BISON_PKGDATADIR=prebuilts/build-tools/common/bison").
+		FlagWithInput("M4=", ctx.Config().PrebuiltBuildTool(ctx, "m4")).
 		Tool(ctx.Config().PrebuiltBuildTool(ctx, "bison")).
 		Flag("-d").
 		Flags(flags).
diff --git a/cc/library.go b/cc/library.go
index f98cd36..5fbb36e 100644
--- a/cc/library.go
+++ b/cc/library.go
@@ -810,7 +810,7 @@
 }
 
 func (library *libraryDecorator) linkSAbiDumpFiles(ctx ModuleContext, objs Objects, fileName string, soFile android.Path) {
-	if len(objs.sAbiDumpFiles) > 0 && library.shouldCreateVndkSourceAbiDump(ctx) {
+	if library.shouldCreateVndkSourceAbiDump(ctx) {
 		vndkVersion := ctx.DeviceConfig().PlatformVndkVersion()
 		if ver := ctx.DeviceConfig().VndkVersion(); ver != "" && ver != "current" {
 			vndkVersion = ver
diff --git a/cc/makevars.go b/cc/makevars.go
index a71f479..78a32c8 100644
--- a/cc/makevars.go
+++ b/cc/makevars.go
@@ -161,6 +161,8 @@
 
 	ctx.Strict("AIDL_CPP", "${aidlCmd}")
 
+	ctx.Strict("M4", "${m4Cmd}")
+
 	ctx.Strict("RS_GLOBAL_INCLUDES", "${config.RsGlobalIncludes}")
 
 	ctx.Strict("SOONG_STRIP_PATH", "${stripPath}")
diff --git a/cc/sanitize.go b/cc/sanitize.go
index 0af0659..0eb9a74 100644
--- a/cc/sanitize.go
+++ b/cc/sanitize.go
@@ -468,6 +468,10 @@
 		// TODO(b/131771163): LTO and Fuzzer support is mutually incompatible.
 		_, flags.LdFlags = removeFromList("-flto", flags.LdFlags)
 		flags.LdFlags = append(flags.LdFlags, "-fno-lto")
+
+		// TODO(b/133876586): Experimental PM breaks sanitizer coverage.
+		_, flags.CFlags = removeFromList("-fexperimental-new-pass-manager", flags.CFlags)
+		flags.CFlags = append(flags.CFlags, "-fno-experimental-new-pass-manager")
 	}
 
 	if Bool(sanitize.Properties.Sanitize.Cfi) {
@@ -701,8 +705,8 @@
 			if !isSanitizableDependencyTag(mctx.OtherModuleDependencyTag(child)) {
 				return false
 			}
-			if d, ok := child.(*Module); ok && d.static() && d.sanitize != nil {
 
+			if d, ok := child.(*Module); ok && d.static() && d.sanitize != nil {
 				if enableMinimalRuntime(d.sanitize) {
 					// If a static dependency is built with the minimal runtime,
 					// make sure we include the ubsan minimal runtime.
@@ -713,8 +717,17 @@
 					// make sure we include the ubsan runtime.
 					c.sanitize.Properties.UbsanRuntimeDep = true
 				}
+
+				if c.sanitize.Properties.MinimalRuntimeDep &&
+					c.sanitize.Properties.UbsanRuntimeDep {
+					// both flags that this mutator might set are true, so don't bother recursing
+					return false
+				}
+
+				return true
+			} else {
+				return false
 			}
-			return true
 		})
 	}
 }
diff --git a/cmd/soong_ui/main.go b/cmd/soong_ui/main.go
index b909779..4d59a39 100644
--- a/cmd/soong_ui/main.go
+++ b/cmd/soong_ui/main.go
@@ -161,6 +161,8 @@
 	trace.SetOutput(filepath.Join(logsDir, "build.trace"))
 	stat.AddOutput(status.NewVerboseLog(log, filepath.Join(logsDir, "verbose.log")))
 	stat.AddOutput(status.NewErrorLog(log, filepath.Join(logsDir, "error.log")))
+	stat.AddOutput(status.NewProtoErrorLog(log, filepath.Join(logsDir, "build_error")))
+	stat.AddOutput(status.NewCriticalPath(log))
 
 	defer met.Dump(filepath.Join(logsDir, "soong_metrics"))
 
@@ -337,7 +339,7 @@
 	}{{
 		name:              "all-modules",
 		description:       "Build action: build from the top of the source tree.",
-		action:            build.BUILD_MODULES_IN_A_DIRECTORY,
+		action:            build.BUILD_MODULES,
 		buildDependencies: true,
 	}, {
 		name:              "modules-in-a-dir-no-deps",
diff --git a/dexpreopt/config.go b/dexpreopt/config.go
index a2f1af4..3e32958 100644
--- a/dexpreopt/config.go
+++ b/dexpreopt/config.go
@@ -79,13 +79,11 @@
 	InstructionSetFeatures map[android.ArchType]string // instruction set for each architecture
 
 	// Only used for boot image
-	DirtyImageObjects      android.OptionalPath // path to a dirty-image-objects file
-	PreloadedClasses       android.OptionalPath // path to a preloaded-classes file
-	BootImageProfiles      android.Paths        // path to a boot-image-profile.txt file
-	UseProfileForBootImage bool                 // whether a profile should be used to compile the boot image
-	BootFlags              string               // extra flags to pass to dex2oat for the boot image
-	Dex2oatImageXmx        string               // max heap size for dex2oat for the boot image
-	Dex2oatImageXms        string               // initial heap size for dex2oat for the boot image
+	DirtyImageObjects android.OptionalPath // path to a dirty-image-objects file
+	BootImageProfiles android.Paths        // path to a boot-image-profile.txt file
+	BootFlags         string               // extra flags to pass to dex2oat for the boot image
+	Dex2oatImageXmx   string               // max heap size for dex2oat for the boot image
+	Dex2oatImageXms   string               // initial heap size for dex2oat for the boot image
 
 	Tools Tools // paths to tools possibly used by the generated commands
 }
@@ -183,7 +181,6 @@
 		// Copies of entries in GlobalConfig that are not constructable without extra parameters.  They will be
 		// used to construct the real value manually below.
 		DirtyImageObjects string
-		PreloadedClasses  string
 		BootImageProfiles []string
 
 		Tools struct {
@@ -206,7 +203,6 @@
 
 	// Construct paths that require a PathContext.
 	config.GlobalConfig.DirtyImageObjects = android.OptionalPathForPath(constructPath(ctx, config.DirtyImageObjects))
-	config.GlobalConfig.PreloadedClasses = android.OptionalPathForPath(constructPath(ctx, config.PreloadedClasses))
 	config.GlobalConfig.BootImageProfiles = constructPaths(ctx, config.BootImageProfiles)
 
 	config.GlobalConfig.Tools.Profman = constructPath(ctx, config.Tools.Profman)
@@ -321,9 +317,7 @@
 		CpuVariant:                         nil,
 		InstructionSetFeatures:             nil,
 		DirtyImageObjects:                  android.OptionalPath{},
-		PreloadedClasses:                   android.OptionalPath{},
 		BootImageProfiles:                  nil,
-		UseProfileForBootImage:             false,
 		BootFlags:                          "",
 		Dex2oatImageXmx:                    "",
 		Dex2oatImageXms:                    "",
diff --git a/finder/finder_test.go b/finder/finder_test.go
index 29711fc..f6d0aa9 100644
--- a/finder/finder_test.go
+++ b/finder/finder_test.go
@@ -891,8 +891,8 @@
 			IncludeFiles: []string{"findme.txt"},
 		},
 	)
-	foundPaths := finder.FindNamedAt("/tmp", "findme.txt")
 	filesystem.Clock.Tick()
+	foundPaths := finder.FindNamedAt("/tmp", "findme.txt")
 	finder.Shutdown()
 	// check the response of the first finder
 	assertSameResponse(t, foundPaths, []string{"/tmp/a/findme.txt"})
@@ -1522,8 +1522,8 @@
 			IncludeFiles: []string{"hi.txt"},
 		},
 	)
-	foundPaths := finder.FindAll()
 	filesystem.Clock.Tick()
+	foundPaths := finder.FindAll()
 	finder.Shutdown()
 	// check results
 	assertSameResponse(t, foundPaths, []string{"/tmp/a/hi.txt"})
@@ -1583,8 +1583,8 @@
 			IncludeFiles: []string{"hi.txt"},
 		},
 	)
-	foundPaths := finder.FindAll()
 	filesystem.Clock.Tick()
+	foundPaths := finder.FindAll()
 	finder.Shutdown()
 	allPaths := []string{"/tmp/hi.txt", "/tmp/a/hi.txt", "/tmp/a/a/hi.txt", "/tmp/b/hi.txt"}
 	// check results
@@ -1629,8 +1629,8 @@
 			IncludeFiles: []string{"hi.txt"},
 		},
 	)
-	foundPaths := finder.FindAll()
 	filesystem.Clock.Tick()
+	foundPaths := finder.FindAll()
 	finder.Shutdown()
 	// check results
 	assertSameResponse(t, foundPaths, []string{"/tmp/hi.txt"})
@@ -1650,8 +1650,8 @@
 			IncludeFiles: []string{"hi.txt"},
 		},
 	)
-	foundPaths := finder.FindAll()
 	filesystem.Clock.Tick()
+	foundPaths := finder.FindAll()
 	finder.Shutdown()
 	// check results
 	assertSameResponse(t, foundPaths, []string{"/tmp/a/hi.txt"})
diff --git a/java/aapt2.go b/java/aapt2.go
index a815160..f0eb99c 100644
--- a/java/aapt2.go
+++ b/java/aapt2.go
@@ -55,12 +55,14 @@
 
 var aapt2CompileRule = pctx.AndroidStaticRule("aapt2Compile",
 	blueprint.RuleParams{
-		Command:     `${config.Aapt2Cmd} compile -o $outDir $cFlags --legacy $in`,
+		Command:     `${config.Aapt2Cmd} compile -o $outDir $cFlags $in`,
 		CommandDeps: []string{"${config.Aapt2Cmd}"},
 	},
 	"outDir", "cFlags")
 
-func aapt2Compile(ctx android.ModuleContext, dir android.Path, paths android.Paths) android.WritablePaths {
+func aapt2Compile(ctx android.ModuleContext, dir android.Path, paths android.Paths,
+	flags []string) android.WritablePaths {
+
 	shards := shardPaths(paths, AAPT2_SHARD_SIZE)
 
 	ret := make(android.WritablePaths, 0, len(paths))
@@ -81,9 +83,7 @@
 			Outputs:     outPaths,
 			Args: map[string]string{
 				"outDir": android.PathForModuleOut(ctx, "aapt2", dir.String()).String(),
-				// Always set --pseudo-localize, it will be stripped out later for release
-				// builds that don't want it.
-				"cFlags": "--pseudo-localize",
+				"cFlags": strings.Join(flags, " "),
 			},
 		})
 	}
@@ -97,14 +97,16 @@
 var aapt2CompileZipRule = pctx.AndroidStaticRule("aapt2CompileZip",
 	blueprint.RuleParams{
 		Command: `${config.ZipSyncCmd} -d $resZipDir $zipSyncFlags $in && ` +
-			`${config.Aapt2Cmd} compile -o $out $cFlags --legacy --dir $resZipDir`,
+			`${config.Aapt2Cmd} compile -o $out $cFlags --dir $resZipDir`,
 		CommandDeps: []string{
 			"${config.Aapt2Cmd}",
 			"${config.ZipSyncCmd}",
 		},
 	}, "cFlags", "resZipDir", "zipSyncFlags")
 
-func aapt2CompileZip(ctx android.ModuleContext, flata android.WritablePath, zip android.Path, zipPrefix string) {
+func aapt2CompileZip(ctx android.ModuleContext, flata android.WritablePath, zip android.Path, zipPrefix string,
+	flags []string) {
+
 	if zipPrefix != "" {
 		zipPrefix = "--zip-prefix " + zipPrefix
 	}
@@ -114,9 +116,7 @@
 		Input:       zip,
 		Output:      flata,
 		Args: map[string]string{
-			// Always set --pseudo-localize, it will be stripped out later for release
-			// builds that don't want it.
-			"cFlags":       "--pseudo-localize",
+			"cFlags":       strings.Join(flags, " "),
 			"resZipDir":    android.PathForModuleOut(ctx, "aapt2", "reszip", flata.Base()).String(),
 			"zipSyncFlags": zipPrefix,
 		},
diff --git a/java/aar.go b/java/aar.go
index a2c203f..ce3d126 100644
--- a/java/aar.go
+++ b/java/aar.go
@@ -17,6 +17,7 @@
 import (
 	"android/soong/android"
 	"fmt"
+	"path/filepath"
 	"strings"
 
 	"github.com/google/blueprint"
@@ -80,6 +81,7 @@
 	rTxt                    android.Path
 	extraAaptPackagesFile   android.Path
 	mergedManifestFile      android.Path
+	noticeFile              android.OptionalPath
 	isLibrary               bool
 	useEmbeddedNativeLibs   bool
 	useEmbeddedDex          bool
@@ -111,8 +113,9 @@
 	return a.transitiveManifestPaths
 }
 
-func (a *aapt) aapt2Flags(ctx android.ModuleContext, sdkContext sdkContext, manifestPath android.Path) (flags []string,
-	deps android.Paths, resDirs, overlayDirs []globbedResourceDir, rroDirs []rroDir, resZips android.Paths) {
+func (a *aapt) aapt2Flags(ctx android.ModuleContext, sdkContext sdkContext,
+	manifestPath android.Path) (compileFlags, linkFlags []string, linkDeps android.Paths,
+	resDirs, overlayDirs []globbedResourceDir, rroDirs []rroDir, resZips android.Paths) {
 
 	hasVersionCode := false
 	hasVersionName := false
@@ -124,8 +127,6 @@
 		}
 	}
 
-	var linkFlags []string
-
 	// Flags specified in Android.bp
 	linkFlags = append(linkFlags, a.aaptProperties.Aaptflags...)
 
@@ -136,8 +137,6 @@
 	resourceDirs := android.PathsWithOptionalDefaultForModuleSrc(ctx, a.aaptProperties.Resource_dirs, "res")
 	resourceZips := android.PathsForModuleSrc(ctx, a.aaptProperties.Resource_zips)
 
-	var linkDeps android.Paths
-
 	// Glob directories into lists of paths
 	for _, dir := range resourceDirs {
 		resDirs = append(resDirs, globbedResourceDir{
@@ -154,10 +153,16 @@
 		assetFiles = append(assetFiles, androidResourceGlob(ctx, dir)...)
 	}
 
+	assetDirStrings := assetDirs.Strings()
+	if a.noticeFile.Valid() {
+		assetDirStrings = append(assetDirStrings, filepath.Dir(a.noticeFile.Path().String()))
+		assetFiles = append(assetFiles, a.noticeFile.Path())
+	}
+
 	linkFlags = append(linkFlags, "--manifest "+manifestPath.String())
 	linkDeps = append(linkDeps, manifestPath)
 
-	linkFlags = append(linkFlags, android.JoinWithPrefix(assetDirs.Strings(), "-A "))
+	linkFlags = append(linkFlags, android.JoinWithPrefix(assetDirStrings, "-A "))
 	linkDeps = append(linkDeps, assetFiles...)
 
 	// SDK version flags
@@ -185,7 +190,13 @@
 		linkFlags = append(linkFlags, "--version-name ", versionName)
 	}
 
-	return linkFlags, linkDeps, resDirs, overlayDirs, rroDirs, resourceZips
+	linkFlags, compileFlags = android.FilterList(linkFlags, []string{"--legacy"})
+
+	// Always set --pseudo-localize, it will be stripped out later for release
+	// builds that don't want it.
+	compileFlags = append(compileFlags, "--pseudo-localize")
+
+	return compileFlags, linkFlags, linkDeps, resDirs, overlayDirs, rroDirs, resourceZips
 }
 
 func (a *aapt) deps(ctx android.BottomUpMutatorContext, sdkDep sdkDep) {
@@ -220,7 +231,7 @@
 		a.mergedManifestFile = manifestPath
 	}
 
-	linkFlags, linkDeps, resDirs, overlayDirs, rroDirs, resZips := a.aapt2Flags(ctx, sdkContext, manifestPath)
+	compileFlags, linkFlags, linkDeps, resDirs, overlayDirs, rroDirs, resZips := a.aapt2Flags(ctx, sdkContext, manifestPath)
 
 	rroDirs = append(rroDirs, staticRRODirs...)
 	linkFlags = append(linkFlags, libFlags...)
@@ -239,12 +250,12 @@
 
 	var compiledResDirs []android.Paths
 	for _, dir := range resDirs {
-		compiledResDirs = append(compiledResDirs, aapt2Compile(ctx, dir.dir, dir.files).Paths())
+		compiledResDirs = append(compiledResDirs, aapt2Compile(ctx, dir.dir, dir.files, compileFlags).Paths())
 	}
 
 	for i, zip := range resZips {
 		flata := android.PathForModuleOut(ctx, fmt.Sprintf("reszip.%d.flata", i))
-		aapt2CompileZip(ctx, flata, zip, "")
+		aapt2CompileZip(ctx, flata, zip, "", compileFlags)
 		compiledResDirs = append(compiledResDirs, android.Paths{flata})
 	}
 
@@ -273,7 +284,7 @@
 	}
 
 	for _, dir := range overlayDirs {
-		compiledOverlay = append(compiledOverlay, aapt2Compile(ctx, dir.dir, dir.files).Paths()...)
+		compiledOverlay = append(compiledOverlay, aapt2Compile(ctx, dir.dir, dir.files, compileFlags).Paths()...)
 	}
 
 	var splitPackages android.WritablePaths
@@ -513,10 +524,6 @@
 	return a.sdkVersion()
 }
 
-func (a *AARImport) noFrameworkLibs() bool {
-	return false
-}
-
 var _ AndroidLibraryDependency = (*AARImport)(nil)
 
 func (a *AARImport) ExportPackage() android.Path {
@@ -598,9 +605,12 @@
 		},
 	})
 
+	// Always set --pseudo-localize, it will be stripped out later for release
+	// builds that don't want it.
+	compileFlags := []string{"--pseudo-localize"}
 	compiledResDir := android.PathForModuleOut(ctx, "flat-res")
 	flata := compiledResDir.Join(ctx, "gen_res.flata")
-	aapt2CompileZip(ctx, flata, aar, "res")
+	aapt2CompileZip(ctx, flata, aar, "res", compileFlags)
 
 	a.exportPackage = android.PathForModuleOut(ctx, "package-res.apk")
 	srcJar := android.PathForModuleGen(ctx, "R.jar")
diff --git a/java/app.go b/java/app.go
index cab97de..f58b0f8 100644
--- a/java/app.go
+++ b/java/app.go
@@ -19,6 +19,7 @@
 import (
 	"path/filepath"
 	"reflect"
+	"sort"
 	"strings"
 
 	"github.com/google/blueprint"
@@ -103,6 +104,10 @@
 	// Use_embedded_native_libs still selects whether they are stored uncompressed and aligned or compressed.
 	// True for android_test* modules.
 	AlwaysPackageNativeLibs bool `blueprint:"mutated"`
+
+	// If set, find and merge all NOTICE files that this module and its dependencies have and store
+	// it in the APK as an asset.
+	Embed_notices *bool
 }
 
 // android_app properties that can be overridden by override_android_app
@@ -224,15 +229,16 @@
 		return true
 	}
 
-	if ctx.Config().UnbundledBuild() {
-		return false
-	}
-
-	// Uncompress dex in APKs of privileged apps
+	// Uncompress dex in APKs of privileged apps (even for unbundled builds, they may
+	// be preinstalled as prebuilts).
 	if ctx.Config().UncompressPrivAppDex() && Bool(a.appProperties.Privileged) {
 		return true
 	}
 
+	if ctx.Config().UnbundledBuild() {
+		return false
+	}
+
 	return shouldUncompressDex(ctx, &a.dexpreopter)
 }
 
@@ -351,6 +357,54 @@
 	return jniJarFile
 }
 
+func (a *AndroidApp) noticeBuildActions(ctx android.ModuleContext, installDir android.OutputPath) android.OptionalPath {
+	if !Bool(a.appProperties.Embed_notices) && !ctx.Config().IsEnvTrue("ALWAYS_EMBED_NOTICES") {
+		return android.OptionalPath{}
+	}
+
+	// Collect NOTICE files from all dependencies.
+	seenModules := make(map[android.Module]bool)
+	noticePathSet := make(map[android.Path]bool)
+
+	ctx.WalkDeps(func(child android.Module, parent android.Module) bool {
+		// Have we already seen this?
+		if _, ok := seenModules[child]; ok {
+			return false
+		}
+		seenModules[child] = true
+
+		// Skip host modules.
+		if child.Target().Os.Class == android.Host || child.Target().Os.Class == android.HostCross {
+			return false
+		}
+
+		path := child.(android.Module).NoticeFile()
+		if path.Valid() {
+			noticePathSet[path.Path()] = true
+		}
+		return true
+	})
+
+	// If the app has one, add it too.
+	if a.NoticeFile().Valid() {
+		noticePathSet[a.NoticeFile().Path()] = true
+	}
+
+	if len(noticePathSet) == 0 {
+		return android.OptionalPath{}
+	}
+	var noticePaths []android.Path
+	for path := range noticePathSet {
+		noticePaths = append(noticePaths, path)
+	}
+	sort.Slice(noticePaths, func(i, j int) bool {
+		return noticePaths[i].String() < noticePaths[j].String()
+	})
+	noticeFile := android.BuildNoticeOutput(ctx, installDir, a.installApkName+".apk", noticePaths)
+
+	return android.OptionalPathForPath(noticeFile)
+}
+
 // Reads and prepends a main cert from the default cert dir if it hasn't been set already, i.e. it
 // isn't a cert module reference. Also checks and enforces system cert restriction if applicable.
 func processMainCert(m android.ModuleBase, certPropValue string, certificates []Certificate, ctx android.ModuleContext) []Certificate {
@@ -391,6 +445,18 @@
 	// Check if the install APK name needs to be overridden.
 	a.installApkName = ctx.DeviceConfig().OverridePackageNameFor(a.Name())
 
+	var installDir android.OutputPath
+	if ctx.ModuleName() == "framework-res" {
+		// framework-res.apk is installed as system/framework/framework-res.apk
+		installDir = android.PathForModuleInstall(ctx, "framework")
+	} else if Bool(a.appProperties.Privileged) {
+		installDir = android.PathForModuleInstall(ctx, "priv-app", a.installApkName)
+	} else {
+		installDir = android.PathForModuleInstall(ctx, "app", a.installApkName)
+	}
+
+	a.aapt.noticeFile = a.noticeBuildActions(ctx, installDir)
+
 	// Process all building blocks, from AAPT to certificates.
 	a.aaptBuildActions(ctx)
 
@@ -432,16 +498,6 @@
 	a.bundleFile = bundleFile
 
 	// Install the app package.
-	var installDir android.OutputPath
-	if ctx.ModuleName() == "framework-res" {
-		// framework-res.apk is installed as system/framework/framework-res.apk
-		installDir = android.PathForModuleInstall(ctx, "framework")
-	} else if Bool(a.appProperties.Privileged) {
-		installDir = android.PathForModuleInstall(ctx, "priv-app", a.installApkName)
-	} else {
-		installDir = android.PathForModuleInstall(ctx, "app", a.installApkName)
-	}
-
 	ctx.InstallFile(installDir, a.installApkName+".apk", a.outputFile)
 	for _, split := range a.aapt.splits {
 		ctx.InstallFile(installDir, a.installApkName+"_"+split.suffix+".apk", split.path)
diff --git a/java/app_test.go b/java/app_test.go
index 27802cd..c7ea338 100644
--- a/java/app_test.go
+++ b/java/app_test.go
@@ -546,79 +546,6 @@
 	}
 }
 
-func TestJNIABI_no_framework_libs_true(t *testing.T) {
-	ctx := testJava(t, cc.GatherRequiredDepsForTest(android.Android)+`
-		cc_library {
-			name: "libjni",
-			system_shared_libs: [],
-			stl: "none",
-		}
-
-		android_test {
-			name: "test",
-			no_framework_libs: true,
-			jni_libs: ["libjni"],
-		}
-
-		android_test {
-			name: "test_first",
-			no_framework_libs: true,
-			compile_multilib: "first",
-			jni_libs: ["libjni"],
-		}
-
-		android_test {
-			name: "test_both",
-			no_framework_libs: true,
-			compile_multilib: "both",
-			jni_libs: ["libjni"],
-		}
-
-		android_test {
-			name: "test_32",
-			no_framework_libs: true,
-			compile_multilib: "32",
-			jni_libs: ["libjni"],
-		}
-
-		android_test {
-			name: "test_64",
-			no_framework_libs: true,
-			compile_multilib: "64",
-			jni_libs: ["libjni"],
-		}
-		`)
-
-	testCases := []struct {
-		name string
-		abis []string
-	}{
-		{"test", []string{"arm64-v8a"}},
-		{"test_first", []string{"arm64-v8a"}},
-		{"test_both", []string{"arm64-v8a", "armeabi-v7a"}},
-		{"test_32", []string{"armeabi-v7a"}},
-		{"test_64", []string{"arm64-v8a"}},
-	}
-
-	for _, test := range testCases {
-		t.Run(test.name, func(t *testing.T) {
-			app := ctx.ModuleForTests(test.name, "android_common")
-			jniLibZip := app.Output("jnilibs.zip")
-			var abis []string
-			args := strings.Fields(jniLibZip.Args["jarArgs"])
-			for i := 0; i < len(args); i++ {
-				if args[i] == "-P" {
-					abis = append(abis, filepath.Base(args[i+1]))
-					i++
-				}
-			}
-			if !reflect.DeepEqual(abis, test.abis) {
-				t.Errorf("want abis %v, got %v", test.abis, abis)
-			}
-		})
-	}
-}
-
 func TestJNIABI(t *testing.T) {
 	ctx := testJava(t, cc.GatherRequiredDepsForTest(android.Android)+`
 		cc_library {
@@ -692,89 +619,6 @@
 	}
 }
 
-func TestJNIPackaging_no_framework_libs_true(t *testing.T) {
-	ctx := testJava(t, cc.GatherRequiredDepsForTest(android.Android)+`
-		cc_library {
-			name: "libjni",
-			system_shared_libs: [],
-			stl: "none",
-		}
-
-		android_app {
-			name: "app",
-			jni_libs: ["libjni"],
-		}
-
-		android_app {
-			name: "app_noembed",
-			jni_libs: ["libjni"],
-			use_embedded_native_libs: false,
-		}
-
-		android_app {
-			name: "app_embed",
-			jni_libs: ["libjni"],
-			use_embedded_native_libs: true,
-		}
-
-		android_test {
-			name: "test",
-			no_framework_libs: true,
-			jni_libs: ["libjni"],
-		}
-
-		android_test {
-			name: "test_noembed",
-			no_framework_libs: true,
-			jni_libs: ["libjni"],
-			use_embedded_native_libs: false,
-		}
-
-		android_test_helper_app {
-			name: "test_helper",
-			no_framework_libs: true,
-			jni_libs: ["libjni"],
-		}
-
-		android_test_helper_app {
-			name: "test_helper_noembed",
-			no_framework_libs: true,
-			jni_libs: ["libjni"],
-			use_embedded_native_libs: false,
-		}
-		`)
-
-	testCases := []struct {
-		name       string
-		packaged   bool
-		compressed bool
-	}{
-		{"app", false, false},
-		{"app_noembed", false, false},
-		{"app_embed", true, false},
-		{"test", true, false},
-		{"test_noembed", true, true},
-		{"test_helper", true, false},
-		{"test_helper_noembed", true, true},
-	}
-
-	for _, test := range testCases {
-		t.Run(test.name, func(t *testing.T) {
-			app := ctx.ModuleForTests(test.name, "android_common")
-			jniLibZip := app.MaybeOutput("jnilibs.zip")
-			if g, w := (jniLibZip.Rule != nil), test.packaged; g != w {
-				t.Errorf("expected jni packaged %v, got %v", w, g)
-			}
-
-			if jniLibZip.Rule != nil {
-				if g, w := !strings.Contains(jniLibZip.Args["jarArgs"], "-L 0"), test.compressed; g != w {
-					t.Errorf("expected jni compressed %v, got %v", w, g)
-				}
-			}
-		})
-	}
-}
-
 func TestJNIPackaging(t *testing.T) {
 	ctx := testJava(t, cc.GatherRequiredDepsForTest(android.Android)+`
 		cc_library {
@@ -1552,3 +1396,181 @@
 		})
 	}
 }
+
+func TestEmbedNotice(t *testing.T) {
+	ctx := testJava(t, cc.GatherRequiredDepsForTest(android.Android)+`
+		android_app {
+			name: "foo",
+			srcs: ["a.java"],
+			static_libs: ["javalib"],
+			jni_libs: ["libjni"],
+			notice: "APP_NOTICE",
+			embed_notices: true,
+		}
+
+		// No embed_notice flag
+		android_app {
+			name: "bar",
+			srcs: ["a.java"],
+			jni_libs: ["libjni"],
+			notice: "APP_NOTICE",
+		}
+
+		// No NOTICE files
+		android_app {
+			name: "baz",
+			srcs: ["a.java"],
+			embed_notices: true,
+		}
+
+		cc_library {
+			name: "libjni",
+			system_shared_libs: [],
+			stl: "none",
+			notice: "LIB_NOTICE",
+		}
+
+		java_library {
+			name: "javalib",
+			srcs: [
+				":gen",
+			],
+		}
+
+		genrule {
+			name: "gen",
+			tools: ["gentool"],
+			out: ["gen.java"],
+			notice: "GENRULE_NOTICE",
+		}
+
+		java_binary_host {
+			name: "gentool",
+			srcs: ["b.java"],
+			notice: "TOOL_NOTICE",
+		}
+	`)
+
+	// foo has NOTICE files to process, and embed_notices is true.
+	foo := ctx.ModuleForTests("foo", "android_common")
+	// verify merge notices rule.
+	mergeNotices := foo.Rule("mergeNoticesRule")
+	noticeInputs := mergeNotices.Inputs.Strings()
+	// TOOL_NOTICE should be excluded as it's a host module.
+	if len(mergeNotices.Inputs) != 3 {
+		t.Errorf("number of input notice files: expected = 3, actual = %q", noticeInputs)
+	}
+	if !inList("APP_NOTICE", noticeInputs) {
+		t.Errorf("APP_NOTICE is missing from notice files, %q", noticeInputs)
+	}
+	if !inList("LIB_NOTICE", noticeInputs) {
+		t.Errorf("LIB_NOTICE is missing from notice files, %q", noticeInputs)
+	}
+	if !inList("GENRULE_NOTICE", noticeInputs) {
+		t.Errorf("GENRULE_NOTICE is missing from notice files, %q", noticeInputs)
+	}
+	// aapt2 flags should include -A <NOTICE dir> so that its contents are put in the APK's /assets.
+	res := foo.Output("package-res.apk")
+	aapt2Flags := res.Args["flags"]
+	e := "-A " + buildDir + "/.intermediates/foo/android_common/NOTICE"
+	if !strings.Contains(aapt2Flags, e) {
+		t.Errorf("asset dir flag for NOTICE, %q is missing in aapt2 link flags, %q", e, aapt2Flags)
+	}
+
+	// bar has NOTICE files to process, but embed_notices is not set.
+	bar := ctx.ModuleForTests("bar", "android_common")
+	mergeNotices = bar.MaybeRule("mergeNoticesRule")
+	if mergeNotices.Rule != nil {
+		t.Errorf("mergeNotices shouldn't have run for bar")
+	}
+
+	// baz's embed_notice is true, but it doesn't have any NOTICE files.
+	baz := ctx.ModuleForTests("baz", "android_common")
+	mergeNotices = baz.MaybeRule("mergeNoticesRule")
+	if mergeNotices.Rule != nil {
+		t.Errorf("mergeNotices shouldn't have run for baz")
+	}
+}
+
+func TestUncompressDex(t *testing.T) {
+	testCases := []struct {
+		name string
+		bp   string
+
+		uncompressedPlatform  bool
+		uncompressedUnbundled bool
+	}{
+		{
+			name: "normal",
+			bp: `
+				android_app {
+					name: "foo",
+					srcs: ["a.java"],
+				}
+			`,
+			uncompressedPlatform:  true,
+			uncompressedUnbundled: false,
+		},
+		{
+			name: "use_embedded_dex",
+			bp: `
+				android_app {
+					name: "foo",
+					use_embedded_dex: true,
+					srcs: ["a.java"],
+				}
+			`,
+			uncompressedPlatform:  true,
+			uncompressedUnbundled: true,
+		},
+		{
+			name: "privileged",
+			bp: `
+				android_app {
+					name: "foo",
+					privileged: true,
+					srcs: ["a.java"],
+				}
+			`,
+			uncompressedPlatform:  true,
+			uncompressedUnbundled: true,
+		},
+	}
+
+	test := func(t *testing.T, bp string, want bool, unbundled bool) {
+		t.Helper()
+
+		config := testConfig(nil)
+		if unbundled {
+			config.TestProductVariables.Unbundled_build = proptools.BoolPtr(true)
+		}
+
+		ctx := testAppContext(config, bp, nil)
+
+		run(t, ctx, config)
+
+		foo := ctx.ModuleForTests("foo", "android_common")
+		dex := foo.Rule("r8")
+		uncompressedInDexJar := strings.Contains(dex.Args["zipFlags"], "-L 0")
+		aligned := foo.MaybeRule("zipalign").Rule != nil
+
+		if uncompressedInDexJar != want {
+			t.Errorf("want uncompressed in dex %v, got %v", want, uncompressedInDexJar)
+		}
+
+		if aligned != want {
+			t.Errorf("want aligned %v, got %v", want, aligned)
+		}
+	}
+
+	for _, tt := range testCases {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Run("platform", func(t *testing.T) {
+				test(t, tt.bp, tt.uncompressedPlatform, false)
+			})
+			t.Run("unbundled", func(t *testing.T) {
+				test(t, tt.bp, tt.uncompressedUnbundled, true)
+			})
+		})
+	}
+}
diff --git a/java/device_host_converter_test.go b/java/device_host_converter_test.go
index 146bf6f..9b9d0d8 100644
--- a/java/device_host_converter_test.go
+++ b/java/device_host_converter_test.go
@@ -126,7 +126,7 @@
 
 		java_library {
 			name: "device_module",
-			no_framework_libs: true,
+			sdk_version: "core_platform",
 			srcs: ["b.java"],
 			java_resources: ["java-res/b/b"],
 			static_libs: ["host_for_device_module"],
diff --git a/java/dexpreopt_bootjars.go b/java/dexpreopt_bootjars.go
index eb735c1..fe468a9 100644
--- a/java/dexpreopt_bootjars.go
+++ b/java/dexpreopt_bootjars.go
@@ -286,8 +286,6 @@
 	if profile != nil {
 		cmd.FlagWithArg("--compiler-filter=", "speed-profile")
 		cmd.FlagWithInput("--profile-file=", profile)
-	} else if global.PreloadedClasses.Valid() {
-		cmd.FlagWithInput("--image-classes=", global.PreloadedClasses.Path())
 	}
 
 	if global.DirtyImageObjects.Valid() {
@@ -374,7 +372,7 @@
 func bootImageProfileRule(ctx android.SingletonContext, image *bootImage, missingDeps []string) android.WritablePath {
 	global := dexpreoptGlobalConfig(ctx)
 
-	if !global.UseProfileForBootImage || ctx.Config().IsPdkBuild() || ctx.Config().UnbundledBuild() {
+	if global.DisableGenerateProfile || ctx.Config().IsPdkBuild() || ctx.Config().UnbundledBuild() {
 		return nil
 	}
 	return ctx.Config().Once(bootImageProfileRuleKey, func() interface{} {
diff --git a/java/dexpreopt_bootjars_test.go b/java/dexpreopt_bootjars_test.go
index cbb52f1..f91ff69 100644
--- a/java/dexpreopt_bootjars_test.go
+++ b/java/dexpreopt_bootjars_test.go
@@ -62,6 +62,7 @@
 	bootArt := dexpreoptBootJars.Output("boot.art")
 
 	expectedInputs := []string{
+		"dex_bootjars/boot.prof",
 		"dex_bootjars_input/foo.jar",
 		"dex_bootjars_input/bar.jar",
 		"dex_bootjars_input/baz.jar",
diff --git a/java/dexpreopt_config.go b/java/dexpreopt_config.go
index c396d3e..4a4d6d5 100644
--- a/java/dexpreopt_config.go
+++ b/java/dexpreopt_config.go
@@ -49,7 +49,8 @@
 		return ctx.Config().Once(dexpreoptTestGlobalConfigKey, func() interface{} {
 			// Nope, return a config with preopting disabled
 			return globalConfigAndRaw{dexpreopt.GlobalConfig{
-				DisablePreopt: true,
+				DisablePreopt:          true,
+				DisableGenerateProfile: true,
 			}, nil}
 		})
 	}).(globalConfigAndRaw)
diff --git a/java/droiddoc.go b/java/droiddoc.go
index 18f337a..25101de 100644
--- a/java/droiddoc.go
+++ b/java/droiddoc.go
@@ -172,9 +172,6 @@
 	// list of java libraries that will be in the classpath.
 	Libs []string `android:"arch_variant"`
 
-	// don't build against the framework libraries (ext, and framework for device targets)
-	No_framework_libs *bool
-
 	// the java library (in classpath) for documentation that provides java srcs and srcjars.
 	Srcs_lib *string
 
@@ -535,10 +532,6 @@
 	return j.sdkVersion()
 }
 
-func (j *Javadoc) noFrameworkLibs() bool {
-	return Bool(j.properties.No_framework_libs)
-}
-
 func (j *Javadoc) addDeps(ctx android.BottomUpMutatorContext) {
 	if ctx.Device() {
 		sdkDep := decodeSdkDep(ctx, sdkContext(j))
diff --git a/java/java.go b/java/java.go
index 0378436..7c84e76 100644
--- a/java/java.go
+++ b/java/java.go
@@ -82,9 +82,6 @@
 	// list of files that should be excluded from java_resources and java_resource_dirs
 	Exclude_java_resources []string `android:"path,arch_variant"`
 
-	// don't build against the framework libraries (ext, and framework for device targets)
-	No_framework_libs *bool
-
 	// list of module-specific flags that will be used for javac compiles
 	Javacflags []string `android:"arch_variant"`
 
@@ -494,10 +491,6 @@
 	return j.sdkVersion()
 }
 
-func (j *Module) noFrameworkLibs() bool {
-	return Bool(j.properties.No_framework_libs)
-}
-
 func (j *Module) deps(ctx android.BottomUpMutatorContext) {
 	if ctx.Device() {
 		sdkDep := decodeSdkDep(ctx, sdkContext(j))
@@ -518,7 +511,7 @@
 			}
 		} else if j.deviceProperties.System_modules == nil {
 			ctx.PropertyErrorf("sdk_version",
-				`system_modules is required to be set when sdk_version is "none", did you mean no_framework_libs?`)
+				`system_modules is required to be set when sdk_version is "none", did you mean "core_platform"`)
 		} else if *j.deviceProperties.System_modules != "none" {
 			ctx.AddVariationDependencies(nil, systemModulesTag, *j.deviceProperties.System_modules)
 		}
diff --git a/java/java_test.go b/java/java_test.go
index 628fec3..677174d 100644
--- a/java/java_test.go
+++ b/java/java_test.go
@@ -121,6 +121,10 @@
 		"b.kt":                   nil,
 		"a.jar":                  nil,
 		"b.jar":                  nil,
+		"APP_NOTICE":             nil,
+		"GENRULE_NOTICE":         nil,
+		"LIB_NOTICE":             nil,
+		"TOOL_NOTICE":            nil,
 		"java-res/a/a":           nil,
 		"java-res/b/b":           nil,
 		"java-res2/a":            nil,
diff --git a/java/sdk.go b/java/sdk.go
index 6ffe399..7b79a49 100644
--- a/java/sdk.go
+++ b/java/sdk.go
@@ -44,9 +44,6 @@
 	minSdkVersion() string
 	// targetSdkVersion returns the target_sdk_version property of the current module, or sdkVersion() if it is not set.
 	targetSdkVersion() string
-
-	// Temporarily provide access to the no_frameworks_libs property (where present).
-	noFrameworkLibs() bool
 }
 
 func sdkVersionOrDefault(ctx android.BaseModuleContext, v string) string {
@@ -84,6 +81,7 @@
 
 func decodeSdkDep(ctx android.BaseModuleContext, sdkContext sdkContext) sdkDep {
 	v := sdkContext.sdkVersion()
+
 	// For PDK builds, use the latest SDK version instead of "current"
 	if ctx.Config().IsPdkBuild() && (v == "" || v == "current") {
 		sdkVersions := ctx.Config().Get(sdkVersionsKey).([]int)
@@ -141,9 +139,6 @@
 			useFiles: true,
 			jars:     android.Paths{jarPath.Path(), lambdaStubsPath},
 			aidl:     android.OptionalPathForPath(aidlPath.Path()),
-
-			// Pass value straight through for now to match previous behavior.
-			noFrameworksLibs: sdkContext.noFrameworkLibs(),
 		}
 	}
 
@@ -154,15 +149,12 @@
 			systemModules:      m + "_system_modules",
 			frameworkResModule: r,
 			aidl:               android.OptionalPathForPath(aidl),
-
-			// Pass value straight through for now to match previous behavior.
-			noFrameworksLibs: sdkContext.noFrameworkLibs(),
 		}
 
 		if m == "core.current.stubs" {
 			ret.systemModules = "core-current-stubs-system-modules"
-		} else if m == "core.platform.api.stubs" {
-			ret.systemModules = "core-platform-api-stubs-system-modules"
+			// core_current does not include framework classes.
+			ret.noFrameworksLibs = true
 		}
 		return ret
 	}
@@ -192,9 +184,6 @@
 		return sdkDep{
 			useDefaultLibs:     true,
 			frameworkResModule: "framework-res",
-
-			// Pass value straight through for now to match previous behavior.
-			noFrameworksLibs: sdkContext.noFrameworkLibs(),
 		}
 	case "none":
 		return sdkDep{
diff --git a/java/sdk_test.go b/java/sdk_test.go
index 953c372..f82a4fb 100644
--- a/java/sdk_test.go
+++ b/java/sdk_test.go
@@ -47,14 +47,6 @@
 			aidl:          "-Iframework/aidl",
 		},
 		{
-			name:          "no_framework_libs:true",
-			properties:    `no_framework_libs:true`,
-			bootclasspath: config.DefaultBootclasspathLibraries,
-			system:        config.DefaultSystemModules,
-			classpath:     []string{},
-			aidl:          "",
-		},
-		{
 			name:          `sdk_version:"core_platform"`,
 			properties:    `sdk_version:"core_platform"`,
 			bootclasspath: config.DefaultBootclasspathLibraries,
diff --git a/java/system_modules.go b/java/system_modules.go
index f71f452..c616249 100644
--- a/java/system_modules.go
+++ b/java/system_modules.go
@@ -138,7 +138,7 @@
 			fmt.Fprintln(w, makevar, ":=$=", strings.Join(system.properties.Libs, " "))
 			fmt.Fprintln(w)
 
-			makevar = "SOONG_SYSTEM_MODULE_DEPS_" + name
+			makevar = "SOONG_SYSTEM_MODULES_DEPS_" + name
 			fmt.Fprintln(w, makevar, ":=$=", strings.Join(system.outputDeps.Strings(), " "))
 			fmt.Fprintln(w)
 
diff --git a/ui/build/config.go b/ui/build/config.go
index 6df9529..4a70f06 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -71,6 +71,9 @@
 	// Builds all of the modules and their dependencies of a list of specified directories. All specified
 	// directories are relative to the root directory of the source tree.
 	BUILD_MODULES_IN_DIRECTORIES
+
+	// Build a list of specified modules. If none was specified, simply build the whole source tree.
+	BUILD_MODULES
 )
 
 // checkTopDir validates that the current directory is at the root directory of the source tree.
@@ -290,6 +293,8 @@
 	var targets []string
 
 	switch action {
+	case BUILD_MODULES:
+		// No additional processing is required when building a list of specific modules or all modules.
 	case BUILD_MODULES_IN_A_DIRECTORY:
 		// If dir is the root source tree, all the modules are built of the source tree are built so
 		// no need to find the build file.
diff --git a/ui/build/config_test.go b/ui/build/config_test.go
index 1ef5456..856af11 100644
--- a/ui/build/config_test.go
+++ b/ui/build/config_test.go
@@ -763,6 +763,51 @@
 	}
 }
 
+func TestGetConfigArgsBuildModules(t *testing.T) {
+	tests := []buildActionTestCase{{
+		description:     "normal execution from the root source tree directory",
+		dirsInTrees:     []string{"0/1/2", "0/2", "0/3"},
+		buildFiles:      []string{"0/1/2/Android.mk", "0/2/Android.bp", "0/3/Android.mk"},
+		args:            []string{"-j", "fake_module", "fake_module2"},
+		curDir:          ".",
+		tidyOnly:        "",
+		expectedArgs:    []string{"-j", "fake_module", "fake_module2"},
+		expectedEnvVars: []envVar{},
+	}, {
+		description:     "normal execution in deep directory",
+		dirsInTrees:     []string{"0/1/2", "0/2", "0/3", "1/2/3/4/5/6/7/8/9/1/2/3/4/5/6"},
+		buildFiles:      []string{"0/1/2/Android.mk", "0/2/Android.bp", "1/2/3/4/5/6/7/8/9/1/2/3/4/5/6/Android.mk"},
+		args:            []string{"-j", "fake_module", "fake_module2", "-k"},
+		curDir:          "1/2/3/4/5/6/7/8/9",
+		tidyOnly:        "",
+		expectedArgs:    []string{"-j", "fake_module", "fake_module2", "-k"},
+		expectedEnvVars: []envVar{},
+	}, {
+		description:     "normal execution in deep directory, no targets",
+		dirsInTrees:     []string{"0/1/2", "0/2", "0/3", "1/2/3/4/5/6/7/8/9/1/2/3/4/5/6"},
+		buildFiles:      []string{"0/1/2/Android.mk", "0/2/Android.bp", "1/2/3/4/5/6/7/8/9/1/2/3/4/5/6/Android.mk"},
+		args:            []string{"-j", "-k"},
+		curDir:          "1/2/3/4/5/6/7/8/9",
+		tidyOnly:        "",
+		expectedArgs:    []string{"-j", "-k"},
+		expectedEnvVars: []envVar{},
+	}, {
+		description:     "normal execution in root source tree, no args",
+		dirsInTrees:     []string{"0/1/2", "0/2", "0/3"},
+		buildFiles:      []string{"0/1/2/Android.mk", "0/2/Android.bp"},
+		args:            []string{},
+		curDir:          "1/2/3/4/5/6/7/8/9",
+		tidyOnly:        "",
+		expectedArgs:    []string{},
+		expectedEnvVars: []envVar{},
+	}}
+	for _, tt := range tests {
+		t.Run("build action BUILD_MODULES with dependencies, "+tt.description, func(t *testing.T) {
+			testGetConfigArgs(t, tt, BUILD_MODULES, true)
+		})
+	}
+}
+
 // TODO: Remove this test case once mm shell build command has been deprecated.
 func TestGetConfigArgsBuildModulesInDirecotoryNoDeps(t *testing.T) {
 	tests := []buildActionTestCase{{
diff --git a/ui/build/paths/config.go b/ui/build/paths/config.go
index c9946e2..e2c5043 100644
--- a/ui/build/paths/config.go
+++ b/ui/build/paths/config.go
@@ -88,13 +88,14 @@
 	"getopt":   Allowed,
 	"git":      Allowed,
 	"grep":     Allowed,
+	"gzcat":    Allowed,
 	"gzip":     Allowed,
 	"hexdump":  Allowed,
 	"jar":      Allowed,
 	"java":     Allowed,
 	"javap":    Allowed,
 	"lsof":     Allowed,
-	"m4":       Allowed,
+	"m4":       Log,
 	"openssl":  Allowed,
 	"patch":    Allowed,
 	"pstree":   Allowed,
diff --git a/ui/status/Android.bp b/ui/status/Android.bp
index 901a713..ec929b3 100644
--- a/ui/status/Android.bp
+++ b/ui/status/Android.bp
@@ -19,14 +19,17 @@
         "golang-protobuf-proto",
         "soong-ui-logger",
         "soong-ui-status-ninja_frontend",
+        "soong-ui-status-build_error_proto",
     ],
     srcs: [
+        "critical_path.go",
         "kati.go",
         "log.go",
         "ninja.go",
         "status.go",
     ],
     testSrcs: [
+        "critical_path_test.go",
         "kati_test.go",
         "ninja_test.go",
         "status_test.go",
@@ -41,3 +44,12 @@
         "ninja_frontend/frontend.pb.go",
     ],
 }
+
+bootstrap_go_package {
+    name: "soong-ui-status-build_error_proto",
+    pkgPath: "android/soong/ui/status/build_error_proto",
+    deps: ["golang-protobuf-proto"],
+    srcs: [
+        "build_error_proto/build_error.pb.go",
+    ],
+}
diff --git a/ui/status/build_error_proto/build_error.pb.go b/ui/status/build_error_proto/build_error.pb.go
new file mode 100644
index 0000000..d4d0a6e
--- /dev/null
+++ b/ui/status/build_error_proto/build_error.pb.go
@@ -0,0 +1,175 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// source: build_error.proto
+
+package soong_build_error_proto
+
+import (
+	fmt "fmt"
+	proto "github.com/golang/protobuf/proto"
+	math "math"
+)
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.ProtoPackageIsVersion3 // please upgrade the proto package
+
+type BuildError struct {
+	// List of error messages of the overall build. The error messages
+	// are not associated with a build action.
+	ErrorMessages []string `protobuf:"bytes,1,rep,name=error_messages,json=errorMessages" json:"error_messages,omitempty"`
+	// List of build action errors.
+	ActionErrors         []*BuildActionError `protobuf:"bytes,2,rep,name=action_errors,json=actionErrors" json:"action_errors,omitempty"`
+	XXX_NoUnkeyedLiteral struct{}            `json:"-"`
+	XXX_unrecognized     []byte              `json:"-"`
+	XXX_sizecache        int32               `json:"-"`
+}
+
+func (m *BuildError) Reset()         { *m = BuildError{} }
+func (m *BuildError) String() string { return proto.CompactTextString(m) }
+func (*BuildError) ProtoMessage()    {}
+func (*BuildError) Descriptor() ([]byte, []int) {
+	return fileDescriptor_a2e15b05802a5501, []int{0}
+}
+
+func (m *BuildError) XXX_Unmarshal(b []byte) error {
+	return xxx_messageInfo_BuildError.Unmarshal(m, b)
+}
+func (m *BuildError) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	return xxx_messageInfo_BuildError.Marshal(b, m, deterministic)
+}
+func (m *BuildError) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_BuildError.Merge(m, src)
+}
+func (m *BuildError) XXX_Size() int {
+	return xxx_messageInfo_BuildError.Size(m)
+}
+func (m *BuildError) XXX_DiscardUnknown() {
+	xxx_messageInfo_BuildError.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_BuildError proto.InternalMessageInfo
+
+func (m *BuildError) GetErrorMessages() []string {
+	if m != nil {
+		return m.ErrorMessages
+	}
+	return nil
+}
+
+func (m *BuildError) GetActionErrors() []*BuildActionError {
+	if m != nil {
+		return m.ActionErrors
+	}
+	return nil
+}
+
+// Build is composed of a list of build action. There can be a set of build
+// actions that can failed.
+type BuildActionError struct {
+	// Description of the command.
+	Description *string `protobuf:"bytes,1,opt,name=description" json:"description,omitempty"`
+	// The command name that raised the error.
+	Command *string `protobuf:"bytes,2,opt,name=command" json:"command,omitempty"`
+	// The command output stream.
+	Output *string `protobuf:"bytes,3,opt,name=output" json:"output,omitempty"`
+	// List of artifacts (i.e. files) that was produced by the command.
+	Artifacts []string `protobuf:"bytes,4,rep,name=artifacts" json:"artifacts,omitempty"`
+	// The error string produced by the build action.
+	Error                *string  `protobuf:"bytes,5,opt,name=error" json:"error,omitempty"`
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
+}
+
+func (m *BuildActionError) Reset()         { *m = BuildActionError{} }
+func (m *BuildActionError) String() string { return proto.CompactTextString(m) }
+func (*BuildActionError) ProtoMessage()    {}
+func (*BuildActionError) Descriptor() ([]byte, []int) {
+	return fileDescriptor_a2e15b05802a5501, []int{1}
+}
+
+func (m *BuildActionError) XXX_Unmarshal(b []byte) error {
+	return xxx_messageInfo_BuildActionError.Unmarshal(m, b)
+}
+func (m *BuildActionError) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	return xxx_messageInfo_BuildActionError.Marshal(b, m, deterministic)
+}
+func (m *BuildActionError) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_BuildActionError.Merge(m, src)
+}
+func (m *BuildActionError) XXX_Size() int {
+	return xxx_messageInfo_BuildActionError.Size(m)
+}
+func (m *BuildActionError) XXX_DiscardUnknown() {
+	xxx_messageInfo_BuildActionError.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_BuildActionError proto.InternalMessageInfo
+
+func (m *BuildActionError) GetDescription() string {
+	if m != nil && m.Description != nil {
+		return *m.Description
+	}
+	return ""
+}
+
+func (m *BuildActionError) GetCommand() string {
+	if m != nil && m.Command != nil {
+		return *m.Command
+	}
+	return ""
+}
+
+func (m *BuildActionError) GetOutput() string {
+	if m != nil && m.Output != nil {
+		return *m.Output
+	}
+	return ""
+}
+
+func (m *BuildActionError) GetArtifacts() []string {
+	if m != nil {
+		return m.Artifacts
+	}
+	return nil
+}
+
+func (m *BuildActionError) GetError() string {
+	if m != nil && m.Error != nil {
+		return *m.Error
+	}
+	return ""
+}
+
+func init() {
+	proto.RegisterType((*BuildError)(nil), "soong_build_error.BuildError")
+	proto.RegisterType((*BuildActionError)(nil), "soong_build_error.BuildActionError")
+}
+
+func init() { proto.RegisterFile("build_error.proto", fileDescriptor_a2e15b05802a5501) }
+
+var fileDescriptor_a2e15b05802a5501 = []byte{
+	// 229 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x64, 0x90, 0xc1, 0x4a, 0xc3, 0x40,
+	0x10, 0x86, 0x49, 0x63, 0x95, 0x4c, 0xad, 0xd8, 0x41, 0x74, 0x04, 0x0f, 0xa1, 0x22, 0xe4, 0x94,
+	0x83, 0x6f, 0x60, 0x41, 0xf0, 0xe2, 0x25, 0x47, 0x2f, 0x61, 0xdd, 0xac, 0x65, 0xc1, 0x64, 0xc2,
+	0xce, 0xe6, 0xe8, 0x8b, 0xf8, 0xb4, 0x92, 0x69, 0xa5, 0xa5, 0x39, 0x7e, 0xdf, 0x3f, 0xfb, 0xef,
+	0xce, 0xc2, 0xea, 0x73, 0xf0, 0xdf, 0x4d, 0xed, 0x42, 0xe0, 0x50, 0xf6, 0x81, 0x23, 0xe3, 0x4a,
+	0x98, 0xbb, 0x6d, 0x7d, 0x14, 0xac, 0x7f, 0x00, 0x36, 0x23, 0xbe, 0x8e, 0x84, 0x4f, 0x70, 0xa5,
+	0xba, 0x6e, 0x9d, 0x88, 0xd9, 0x3a, 0xa1, 0x24, 0x4f, 0x8b, 0xac, 0x5a, 0xaa, 0x7d, 0xdf, 0x4b,
+	0x7c, 0x83, 0xa5, 0xb1, 0xd1, 0x73, 0xb7, 0x2b, 0x11, 0x9a, 0xe5, 0x69, 0xb1, 0x78, 0x7e, 0x2c,
+	0x27, 0xfd, 0xa5, 0x96, 0xbf, 0xe8, 0xb0, 0x5e, 0x51, 0x5d, 0x9a, 0x03, 0xc8, 0xfa, 0x37, 0x81,
+	0xeb, 0xd3, 0x11, 0xcc, 0x61, 0xd1, 0x38, 0xb1, 0xc1, 0xf7, 0xa3, 0xa3, 0x24, 0x4f, 0x8a, 0xac,
+	0x3a, 0x56, 0x48, 0x70, 0x61, 0xb9, 0x6d, 0x4d, 0xd7, 0xd0, 0x4c, 0xd3, 0x7f, 0xc4, 0x5b, 0x38,
+	0xe7, 0x21, 0xf6, 0x43, 0xa4, 0x54, 0x83, 0x3d, 0xe1, 0x03, 0x64, 0x26, 0x44, 0xff, 0x65, 0x6c,
+	0x14, 0x3a, 0xd3, 0xa5, 0x0e, 0x02, 0x6f, 0x60, 0xae, 0xcf, 0xa5, 0xb9, 0x1e, 0xda, 0xc1, 0xe6,
+	0xfe, 0xe3, 0x6e, 0xb2, 0x50, 0xad, 0x3f, 0xf9, 0x17, 0x00, 0x00, 0xff, 0xff, 0xb6, 0x18, 0x9e,
+	0x17, 0x5d, 0x01, 0x00, 0x00,
+}
diff --git a/ui/status/build_error_proto/build_error.proto b/ui/status/build_error_proto/build_error.proto
new file mode 100644
index 0000000..9c8470d
--- /dev/null
+++ b/ui/status/build_error_proto/build_error.proto
@@ -0,0 +1,46 @@
+// Copyright 2019 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.
+
+syntax = "proto2";
+
+package soong_build_error;
+option go_package = "soong_build_error_proto";
+
+message BuildError {
+  // List of error messages of the overall build. The error messages
+  // are not associated with a build action.
+  repeated string error_messages = 1;
+
+  // List of build action errors.
+  repeated BuildActionError action_errors = 2;
+}
+
+// Build is composed of a list of build action. There can be a set of build
+// actions that can failed.
+message BuildActionError {
+  // Description of the command.
+  optional string description = 1;
+
+  // The command name that raised the error.
+  optional string command = 2;
+
+  // The command output stream.
+  optional string output = 3;
+
+  // List of artifacts (i.e. files) that was produced by the command.
+  repeated string artifacts = 4;
+
+  // The error string produced by the build action.
+  optional string error = 5;
+}
diff --git a/ui/status/build_error_proto/regen.sh b/ui/status/build_error_proto/regen.sh
new file mode 100755
index 0000000..7c3ec8f
--- /dev/null
+++ b/ui/status/build_error_proto/regen.sh
@@ -0,0 +1,3 @@
+#!/bin/bash
+
+aprotoc --go_out=paths=source_relative:. build_error.proto
diff --git a/ui/status/critical_path.go b/ui/status/critical_path.go
new file mode 100644
index 0000000..444327b
--- /dev/null
+++ b/ui/status/critical_path.go
@@ -0,0 +1,152 @@
+// Copyright 2019 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 status
+
+import (
+	"time"
+
+	"android/soong/ui/logger"
+)
+
+func NewCriticalPath(log logger.Logger) StatusOutput {
+	return &criticalPath{
+		log:     log,
+		running: make(map[*Action]time.Time),
+		nodes:   make(map[string]*node),
+		clock:   osClock{},
+	}
+}
+
+type criticalPath struct {
+	log logger.Logger
+
+	nodes   map[string]*node
+	running map[*Action]time.Time
+
+	start, end time.Time
+
+	clock clock
+}
+
+type clock interface {
+	Now() time.Time
+}
+
+type osClock struct{}
+
+func (osClock) Now() time.Time { return time.Now() }
+
+// A critical path node stores the critical path (the minimum time to build the node and all of its dependencies given
+// perfect parallelism) for an node.
+type node struct {
+	action             *Action
+	cumulativeDuration time.Duration
+	duration           time.Duration
+	input              *node
+}
+
+func (cp *criticalPath) StartAction(action *Action, counts Counts) {
+	start := cp.clock.Now()
+	if cp.start.IsZero() {
+		cp.start = start
+	}
+	cp.running[action] = start
+}
+
+func (cp *criticalPath) FinishAction(result ActionResult, counts Counts) {
+	if start, ok := cp.running[result.Action]; ok {
+		delete(cp.running, result.Action)
+
+		// Determine the input to this edge with the longest cumulative duration
+		var criticalPathInput *node
+		for _, input := range result.Action.Inputs {
+			if x := cp.nodes[input]; x != nil {
+				if criticalPathInput == nil || x.cumulativeDuration > criticalPathInput.cumulativeDuration {
+					criticalPathInput = x
+				}
+			}
+		}
+
+		end := cp.clock.Now()
+		duration := end.Sub(start)
+
+		cumulativeDuration := duration
+		if criticalPathInput != nil {
+			cumulativeDuration += criticalPathInput.cumulativeDuration
+		}
+
+		node := &node{
+			action:             result.Action,
+			cumulativeDuration: cumulativeDuration,
+			duration:           duration,
+			input:              criticalPathInput,
+		}
+
+		for _, output := range result.Action.Outputs {
+			cp.nodes[output] = node
+		}
+
+		cp.end = end
+	}
+}
+
+func (cp *criticalPath) Flush() {
+	criticalPath := cp.criticalPath()
+
+	if len(criticalPath) > 0 {
+		// Log the critical path to the verbose log
+		criticalTime := criticalPath[0].cumulativeDuration.Round(time.Second)
+		cp.log.Verbosef("critical path took %s", criticalTime.String())
+		if !cp.start.IsZero() {
+			elapsedTime := cp.end.Sub(cp.start).Round(time.Second)
+			cp.log.Verbosef("elapsed time %s", elapsedTime.String())
+			cp.log.Verbosef("perfect parallelism ratio %d%%",
+				int(float64(criticalTime)/float64(elapsedTime)*100))
+		}
+		cp.log.Verbose("critical path:")
+		for i := len(criticalPath) - 1; i >= 0; i-- {
+			duration := criticalPath[i].duration
+			duration = duration.Round(time.Second)
+			seconds := int(duration.Seconds())
+			cp.log.Verbosef("   %2d:%02d %s",
+				seconds/60, seconds%60, criticalPath[i].action.Description)
+		}
+	}
+}
+
+func (cp *criticalPath) Message(level MsgLevel, msg string) {}
+
+func (cp *criticalPath) Write(p []byte) (n int, err error) { return len(p), nil }
+
+func (cp *criticalPath) criticalPath() []*node {
+	var max *node
+
+	// Find the node with the longest critical path
+	for _, node := range cp.nodes {
+		if max == nil || node.cumulativeDuration > max.cumulativeDuration {
+			max = node
+		}
+	}
+
+	// Follow the critical path back to the leaf node
+	var criticalPath []*node
+	node := max
+	for node != nil {
+		criticalPath = append(criticalPath, node)
+		node = node.input
+	}
+
+	return criticalPath
+}
diff --git a/ui/status/critical_path_test.go b/ui/status/critical_path_test.go
new file mode 100644
index 0000000..965e0ad
--- /dev/null
+++ b/ui/status/critical_path_test.go
@@ -0,0 +1,166 @@
+// Copyright 2019 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 status
+
+import (
+	"reflect"
+	"testing"
+	"time"
+)
+
+type testCriticalPath struct {
+	*criticalPath
+	Counts
+
+	actions map[int]*Action
+}
+
+type testClock time.Time
+
+func (t testClock) Now() time.Time { return time.Time(t) }
+
+func (t *testCriticalPath) start(id int, startTime time.Duration, outputs, inputs []string) {
+	t.clock = testClock(time.Unix(0, 0).Add(startTime))
+	action := &Action{
+		Description: outputs[0],
+		Outputs:     outputs,
+		Inputs:      inputs,
+	}
+
+	t.actions[id] = action
+	t.StartAction(action, t.Counts)
+}
+
+func (t *testCriticalPath) finish(id int, endTime time.Duration) {
+	t.clock = testClock(time.Unix(0, 0).Add(endTime))
+	t.FinishAction(ActionResult{
+		Action: t.actions[id],
+	}, t.Counts)
+}
+
+func TestCriticalPath(t *testing.T) {
+	tests := []struct {
+		name     string
+		msgs     func(*testCriticalPath)
+		want     []string
+		wantTime time.Duration
+	}{
+		{
+			name: "empty",
+			msgs: func(cp *testCriticalPath) {},
+		},
+		{
+			name: "duplicate",
+			msgs: func(cp *testCriticalPath) {
+				cp.start(0, 0, []string{"a"}, nil)
+				cp.start(1, 0, []string{"a"}, nil)
+				cp.finish(0, 1000)
+				cp.finish(0, 2000)
+			},
+			want:     []string{"a"},
+			wantTime: 1000,
+		},
+		{
+			name: "linear",
+			//  a
+			//  |
+			//  b
+			//  |
+			//  c
+			msgs: func(cp *testCriticalPath) {
+				cp.start(0, 0, []string{"a"}, nil)
+				cp.finish(0, 1000)
+				cp.start(1, 1000, []string{"b"}, []string{"a"})
+				cp.finish(1, 2000)
+				cp.start(2, 3000, []string{"c"}, []string{"b"})
+				cp.finish(2, 4000)
+			},
+			want:     []string{"c", "b", "a"},
+			wantTime: 3000,
+		},
+		{
+			name: "diamond",
+			//  a
+			//  |\
+			//  b c
+			//  |/
+			//  d
+			msgs: func(cp *testCriticalPath) {
+				cp.start(0, 0, []string{"a"}, nil)
+				cp.finish(0, 1000)
+				cp.start(1, 1000, []string{"b"}, []string{"a"})
+				cp.start(2, 1000, []string{"c"}, []string{"a"})
+				cp.finish(1, 2000)
+				cp.finish(2, 3000)
+				cp.start(3, 3000, []string{"d"}, []string{"b", "c"})
+				cp.finish(3, 4000)
+			},
+			want:     []string{"d", "c", "a"},
+			wantTime: 4000,
+		},
+		{
+			name: "multiple",
+			//  a d
+			//  | |
+			//  b e
+			//  |
+			//  c
+			msgs: func(cp *testCriticalPath) {
+				cp.start(0, 0, []string{"a"}, nil)
+				cp.start(3, 0, []string{"d"}, nil)
+				cp.finish(0, 1000)
+				cp.finish(3, 1000)
+				cp.start(1, 1000, []string{"b"}, []string{"a"})
+				cp.start(4, 1000, []string{"e"}, []string{"d"})
+				cp.finish(1, 2000)
+				cp.start(2, 2000, []string{"c"}, []string{"b"})
+				cp.finish(2, 3000)
+				cp.finish(4, 4000)
+
+			},
+			want:     []string{"e", "d"},
+			wantTime: 4000,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			cp := &testCriticalPath{
+				criticalPath: NewCriticalPath(nil).(*criticalPath),
+				actions:      make(map[int]*Action),
+			}
+
+			tt.msgs(cp)
+
+			criticalPath := cp.criticalPath.criticalPath()
+
+			var descs []string
+			for _, x := range criticalPath {
+				descs = append(descs, x.action.Description)
+			}
+
+			if !reflect.DeepEqual(descs, tt.want) {
+				t.Errorf("criticalPath.criticalPath() = %v, want %v", descs, tt.want)
+			}
+
+			var gotTime time.Duration
+			if len(criticalPath) > 0 {
+				gotTime = criticalPath[0].cumulativeDuration
+			}
+			if gotTime != tt.wantTime {
+				t.Errorf("cumulativeDuration[0].cumulativeDuration = %v, want %v", gotTime, tt.wantTime)
+			}
+		})
+	}
+}
diff --git a/ui/status/log.go b/ui/status/log.go
index 7badac7..9090f49 100644
--- a/ui/status/log.go
+++ b/ui/status/log.go
@@ -15,11 +15,17 @@
 package status
 
 import (
-	"android/soong/ui/logger"
 	"compress/gzip"
+	"errors"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"strings"
+
+	"github.com/golang/protobuf/proto"
+
+	"android/soong/ui/logger"
+	"android/soong/ui/status/build_error_proto"
 )
 
 type verboseLog struct {
@@ -77,8 +83,7 @@
 }
 
 type errorLog struct {
-	w io.WriteCloser
-
+	w     io.WriteCloser
 	empty bool
 }
 
@@ -102,20 +107,17 @@
 		return
 	}
 
-	cmd := result.Command
-	if cmd == "" {
-		cmd = result.Description
-	}
-
 	if !e.empty {
 		fmt.Fprintf(e.w, "\n\n")
 	}
 	e.empty = false
 
 	fmt.Fprintf(e.w, "FAILED: %s\n", result.Description)
+
 	if len(result.Outputs) > 0 {
 		fmt.Fprintf(e.w, "Outputs: %s\n", strings.Join(result.Outputs, " "))
 	}
+
 	fmt.Fprintf(e.w, "Error: %s\n", result.Error)
 	if result.Command != "" {
 		fmt.Fprintf(e.w, "Command: %s\n", result.Command)
@@ -144,3 +146,55 @@
 	fmt.Fprint(e.w, string(p))
 	return len(p), nil
 }
+
+type errorProtoLog struct {
+	errorProto soong_build_error_proto.BuildError
+	filename   string
+	log        logger.Logger
+}
+
+func NewProtoErrorLog(log logger.Logger, filename string) StatusOutput {
+	return &errorProtoLog{
+		errorProto: soong_build_error_proto.BuildError{},
+		filename:   filename,
+		log:        log,
+	}
+}
+
+func (e *errorProtoLog) StartAction(action *Action, counts Counts) {}
+
+func (e *errorProtoLog) FinishAction(result ActionResult, counts Counts) {
+	if result.Error == nil {
+		return
+	}
+
+	e.errorProto.ActionErrors = append(e.errorProto.ActionErrors, &soong_build_error_proto.BuildActionError{
+		Description: proto.String(result.Description),
+		Command:     proto.String(result.Command),
+		Output:      proto.String(result.Output),
+		Artifacts:   result.Outputs,
+		Error:       proto.String(result.Error.Error()),
+	})
+}
+
+func (e *errorProtoLog) Flush() {
+	data, err := proto.Marshal(&e.errorProto)
+	if err != nil {
+		e.log.Println("Failed to marshal build status proto: %v", err)
+		return
+	}
+	err = ioutil.WriteFile(e.filename, []byte(data), 0644)
+	if err != nil {
+		e.log.Println("Failed to write file %s: %v", e.errorProto, err)
+	}
+}
+
+func (e *errorProtoLog) Message(level MsgLevel, message string) {
+	if level > ErrorLvl {
+		e.errorProto.ErrorMessages = append(e.errorProto.ErrorMessages, message)
+	}
+}
+
+func (e *errorProtoLog) Write(p []byte) (int, error) {
+	return 0, errors.New("not supported")
+}
diff --git a/ui/status/ninja.go b/ui/status/ninja.go
index ee2a2da..9cf2f6a 100644
--- a/ui/status/ninja.go
+++ b/ui/status/ninja.go
@@ -142,6 +142,7 @@
 			action := &Action{
 				Description: msg.EdgeStarted.GetDesc(),
 				Outputs:     msg.EdgeStarted.Outputs,
+				Inputs:      msg.EdgeStarted.Inputs,
 				Command:     msg.EdgeStarted.GetCommand(),
 			}
 			n.status.StartAction(action)
diff --git a/ui/status/status.go b/ui/status/status.go
index 3d8cd7a..df33baa 100644
--- a/ui/status/status.go
+++ b/ui/status/status.go
@@ -32,6 +32,10 @@
 	// but they can be any string.
 	Outputs []string
 
+	// Inputs is the (optional) list of inputs. Usually these are files,
+	// but they can be any string.
+	Inputs []string
+
 	// Command is the actual command line executed to perform the action.
 	// It's optional, but one of either Description or Command should be
 	// set.
diff --git a/ui/terminal/smart_status.go b/ui/terminal/smart_status.go
index 82c04d4..8659d4d 100644
--- a/ui/terminal/smart_status.go
+++ b/ui/terminal/smart_status.go
@@ -19,13 +19,22 @@
 	"io"
 	"os"
 	"os/signal"
+	"strconv"
 	"strings"
 	"sync"
 	"syscall"
+	"time"
 
 	"android/soong/ui/status"
 )
 
+const tableHeightEnVar = "SOONG_UI_TABLE_HEIGHT"
+
+type actionTableEntry struct {
+	action    *status.Action
+	startTime time.Time
+}
+
 type smartStatusOutput struct {
 	writer    io.Writer
 	formatter formatter
@@ -34,7 +43,14 @@
 
 	haveBlankLine bool
 
-	termWidth       int
+	tableMode             bool
+	tableHeight           int
+	requestedTableHeight  int
+	termWidth, termHeight int
+
+	runningActions  []actionTableEntry
+	ticker          *time.Ticker
+	done            chan bool
 	sigwinch        chan os.Signal
 	sigwinchHandled chan bool
 }
@@ -43,17 +59,41 @@
 // current build status similarly to Ninja's built-in terminal
 // output.
 func NewSmartStatusOutput(w io.Writer, formatter formatter) status.StatusOutput {
+	tableHeight, _ := strconv.Atoi(os.Getenv(tableHeightEnVar))
+
 	s := &smartStatusOutput{
 		writer:    w,
 		formatter: formatter,
 
 		haveBlankLine: true,
 
+		tableMode:            tableHeight > 0,
+		requestedTableHeight: tableHeight,
+
+		done:     make(chan bool),
 		sigwinch: make(chan os.Signal),
 	}
 
 	s.updateTermSize()
 
+	if s.tableMode {
+		// Add empty lines at the bottom of the screen to scroll back the existing history
+		// and make room for the action table.
+		// TODO: read the cursor position to see if the empty lines are necessary?
+		for i := 0; i < s.tableHeight; i++ {
+			fmt.Fprintln(w)
+		}
+
+		// Hide the cursor to prevent seeing it bouncing around
+		fmt.Fprintf(s.writer, ansi.hideCursor())
+
+		// Configure the empty action table
+		s.actionTable()
+
+		// Start a tick to update the action table periodically
+		s.startActionTableTick()
+	}
+
 	s.startSigwinch()
 
 	return s
@@ -77,6 +117,8 @@
 }
 
 func (s *smartStatusOutput) StartAction(action *status.Action, counts status.Counts) {
+	startTime := time.Now()
+
 	str := action.Description
 	if str == "" {
 		str = action.Command
@@ -87,6 +129,11 @@
 	s.lock.Lock()
 	defer s.lock.Unlock()
 
+	s.runningActions = append(s.runningActions, actionTableEntry{
+		action:    action,
+		startTime: startTime,
+	})
+
 	s.statusLine(progress + str)
 }
 
@@ -103,6 +150,13 @@
 	s.lock.Lock()
 	defer s.lock.Unlock()
 
+	for i, runningAction := range s.runningActions {
+		if runningAction.action == result.Action {
+			s.runningActions = append(s.runningActions[:i], s.runningActions[i+1:]...)
+			break
+		}
+	}
+
 	if output != "" {
 		s.statusLine(progress)
 		s.requestLine()
@@ -119,6 +173,23 @@
 	s.stopSigwinch()
 
 	s.requestLine()
+
+	s.runningActions = nil
+
+	if s.tableMode {
+		s.stopActionTableTick()
+
+		// Update the table after clearing runningActions to clear it
+		s.actionTable()
+
+		// Reset the scrolling region to the whole terminal
+		fmt.Fprintf(s.writer, ansi.resetScrollingMargins())
+		_, height, _ := termSize(s.writer)
+		// Move the cursor to the top of the now-blank, previously non-scrolling region
+		fmt.Fprintf(s.writer, ansi.setCursor(height-s.tableHeight, 0))
+		// Turn the cursor back on
+		fmt.Fprintf(s.writer, ansi.showCursor())
+	}
 }
 
 func (s *smartStatusOutput) Write(p []byte) (int, error) {
@@ -137,7 +208,7 @@
 
 func (s *smartStatusOutput) print(str string) {
 	if !s.haveBlankLine {
-		fmt.Fprint(s.writer, "\r", "\x1b[K")
+		fmt.Fprint(s.writer, "\r", ansi.clearToEndOfLine())
 		s.haveBlankLine = true
 	}
 	fmt.Fprint(s.writer, str)
@@ -154,34 +225,56 @@
 
 	// Limit line width to the terminal width, otherwise we'll wrap onto
 	// another line and we won't delete the previous line.
-	if s.termWidth > 0 {
-		str = s.elide(str)
-	}
+	str = elide(str, s.termWidth)
 
 	// Move to the beginning on the line, turn on bold, print the output,
 	// turn off bold, then clear the rest of the line.
-	start := "\r\x1b[1m"
-	end := "\x1b[0m\x1b[K"
+	start := "\r" + ansi.bold()
+	end := ansi.regular() + ansi.clearToEndOfLine()
 	fmt.Fprint(s.writer, start, str, end)
 	s.haveBlankLine = false
 }
 
-func (s *smartStatusOutput) elide(str string) string {
-	if len(str) > s.termWidth {
+func elide(str string, width int) string {
+	if width > 0 && len(str) > width {
 		// TODO: Just do a max. Ninja elides the middle, but that's
 		// more complicated and these lines aren't that important.
-		str = str[:s.termWidth]
+		str = str[:width]
 	}
 
 	return str
 }
 
+func (s *smartStatusOutput) startActionTableTick() {
+	s.ticker = time.NewTicker(time.Second)
+	go func() {
+		for {
+			select {
+			case <-s.ticker.C:
+				s.lock.Lock()
+				s.actionTable()
+				s.lock.Unlock()
+			case <-s.done:
+				return
+			}
+		}
+	}()
+}
+
+func (s *smartStatusOutput) stopActionTableTick() {
+	s.ticker.Stop()
+	s.done <- true
+}
+
 func (s *smartStatusOutput) startSigwinch() {
 	signal.Notify(s.sigwinch, syscall.SIGWINCH)
 	go func() {
 		for _ = range s.sigwinch {
 			s.lock.Lock()
 			s.updateTermSize()
+			if s.tableMode {
+				s.actionTable()
+			}
 			s.lock.Unlock()
 			if s.sigwinchHandled != nil {
 				s.sigwinchHandled <- true
@@ -196,7 +289,139 @@
 }
 
 func (s *smartStatusOutput) updateTermSize() {
-	if w, ok := termWidth(s.writer); ok {
-		s.termWidth = w
+	if w, h, ok := termSize(s.writer); ok {
+		firstUpdate := s.termHeight == 0 && s.termWidth == 0
+		oldScrollingHeight := s.termHeight - s.tableHeight
+
+		s.termWidth, s.termHeight = w, h
+
+		if s.tableMode {
+			tableHeight := s.requestedTableHeight
+			if tableHeight > s.termHeight-1 {
+				tableHeight = s.termHeight - 1
+			}
+			s.tableHeight = tableHeight
+
+			scrollingHeight := s.termHeight - s.tableHeight
+
+			if !firstUpdate {
+				// If the scrolling region has changed, attempt to pan the existing text so that it is
+				// not overwritten by the table.
+				if scrollingHeight < oldScrollingHeight {
+					pan := oldScrollingHeight - scrollingHeight
+					if pan > s.tableHeight {
+						pan = s.tableHeight
+					}
+					fmt.Fprint(s.writer, ansi.panDown(pan))
+				}
+			}
+		}
 	}
 }
+
+func (s *smartStatusOutput) actionTable() {
+	scrollingHeight := s.termHeight - s.tableHeight
+
+	// Update the scrolling region in case the height of the terminal changed
+	fmt.Fprint(s.writer, ansi.setScrollingMargins(0, scrollingHeight))
+	// Move the cursor to the first line of the non-scrolling region
+	fmt.Fprint(s.writer, ansi.setCursor(scrollingHeight+1, 0))
+
+	// Write as many status lines as fit in the table
+	var tableLine int
+	var runningAction actionTableEntry
+	for tableLine, runningAction = range s.runningActions {
+		if tableLine >= s.tableHeight {
+			break
+		}
+
+		seconds := int(time.Since(runningAction.startTime).Round(time.Second).Seconds())
+
+		desc := runningAction.action.Description
+		if desc == "" {
+			desc = runningAction.action.Command
+		}
+
+		color := ""
+		if seconds >= 60 {
+			color = ansi.red() + ansi.bold()
+		} else if seconds >= 30 {
+			color = ansi.yellow() + ansi.bold()
+		}
+
+		durationStr := fmt.Sprintf("   %2d:%02d ", seconds/60, seconds%60)
+		desc = elide(desc, s.termWidth-len(durationStr))
+		durationStr = color + durationStr + ansi.regular()
+
+		fmt.Fprint(s.writer, durationStr, desc, ansi.clearToEndOfLine())
+		if tableLine < s.tableHeight-1 {
+			fmt.Fprint(s.writer, "\n")
+		}
+	}
+
+	// Clear any remaining lines in the table
+	for ; tableLine < s.tableHeight; tableLine++ {
+		fmt.Fprint(s.writer, ansi.clearToEndOfLine())
+		if tableLine < s.tableHeight-1 {
+			fmt.Fprint(s.writer, "\n")
+		}
+	}
+
+	// Move the cursor back to the last line of the scrolling region
+	fmt.Fprint(s.writer, ansi.setCursor(scrollingHeight, 0))
+}
+
+var ansi = ansiImpl{}
+
+type ansiImpl struct{}
+
+func (ansiImpl) clearToEndOfLine() string {
+	return "\x1b[K"
+}
+
+func (ansiImpl) setCursor(row, column int) string {
+	// Direct cursor address
+	return fmt.Sprintf("\x1b[%d;%dH", row, column)
+}
+
+func (ansiImpl) setScrollingMargins(top, bottom int) string {
+	// Set Top and Bottom Margins DECSTBM
+	return fmt.Sprintf("\x1b[%d;%dr", top, bottom)
+}
+
+func (ansiImpl) resetScrollingMargins() string {
+	// Set Top and Bottom Margins DECSTBM
+	return fmt.Sprintf("\x1b[r")
+}
+
+func (ansiImpl) red() string {
+	return "\x1b[31m"
+}
+
+func (ansiImpl) yellow() string {
+	return "\x1b[33m"
+}
+
+func (ansiImpl) bold() string {
+	return "\x1b[1m"
+}
+
+func (ansiImpl) regular() string {
+	return "\x1b[0m"
+}
+
+func (ansiImpl) showCursor() string {
+	return "\x1b[?25h"
+}
+
+func (ansiImpl) hideCursor() string {
+	return "\x1b[?25l"
+}
+
+func (ansiImpl) panDown(lines int) string {
+	return fmt.Sprintf("\x1b[%dS", lines)
+}
+
+func (ansiImpl) panUp(lines int) string {
+	return fmt.Sprintf("\x1b[%dT", lines)
+}
diff --git a/ui/terminal/status_test.go b/ui/terminal/status_test.go
index 106d651..81aa238 100644
--- a/ui/terminal/status_test.go
+++ b/ui/terminal/status_test.go
@@ -17,6 +17,7 @@
 import (
 	"bytes"
 	"fmt"
+	"os"
 	"syscall"
 	"testing"
 
@@ -86,8 +87,11 @@
 		},
 	}
 
+	os.Setenv(tableHeightEnVar, "")
+
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
+
 			t.Run("smart", func(t *testing.T) {
 				smart := &fakeSmartTerminal{termWidth: 40}
 				stat := NewStatusOutput(smart, "", false)
@@ -251,6 +255,8 @@
 }
 
 func TestSmartStatusOutputWidthChange(t *testing.T) {
+	os.Setenv(tableHeightEnVar, "")
+
 	smart := &fakeSmartTerminal{termWidth: 40}
 	stat := NewStatusOutput(smart, "", false)
 	smartStat := stat.(*smartStatusOutput)
diff --git a/ui/terminal/util.go b/ui/terminal/util.go
index 3a11b79..f383ef1 100644
--- a/ui/terminal/util.go
+++ b/ui/terminal/util.go
@@ -23,6 +23,9 @@
 )
 
 func isSmartTerminal(w io.Writer) bool {
+	if term, ok := os.LookupEnv("TERM"); ok && term == "dumb" {
+		return false
+	}
 	if f, ok := w.(*os.File); ok {
 		var termios syscall.Termios
 		_, _, err := syscall.Syscall6(syscall.SYS_IOCTL, f.Fd(),
@@ -35,7 +38,7 @@
 	return false
 }
 
-func termWidth(w io.Writer) (int, bool) {
+func termSize(w io.Writer) (width int, height int, ok bool) {
 	if f, ok := w.(*os.File); ok {
 		var winsize struct {
 			ws_row, ws_column    uint16
@@ -44,11 +47,11 @@
 		_, _, err := syscall.Syscall6(syscall.SYS_IOCTL, f.Fd(),
 			syscall.TIOCGWINSZ, uintptr(unsafe.Pointer(&winsize)),
 			0, 0, 0)
-		return int(winsize.ws_column), err == 0
+		return int(winsize.ws_column), int(winsize.ws_row), err == 0
 	} else if f, ok := w.(*fakeSmartTerminal); ok {
-		return f.termWidth, true
+		return f.termWidth, f.termHeight, true
 	}
-	return 0, false
+	return 0, 0, false
 }
 
 // stripAnsiEscapes strips ANSI control codes from a byte array in place.
@@ -106,5 +109,5 @@
 
 type fakeSmartTerminal struct {
 	bytes.Buffer
-	termWidth int
+	termWidth, termHeight int
 }