diff --git a/Android.bp b/Android.bp
index 4db98f8..614e71f 100644
--- a/Android.bp
+++ b/Android.bp
@@ -78,10 +78,12 @@
         "android/env.go",
     ],
     testSrcs: [
+        "android/android_test.go",
         "android/arch_test.go",
         "android/config_test.go",
         "android/expand_test.go",
         "android/module_test.go",
+        "android/mutator_test.go",
         "android/namespace_test.go",
         "android/neverallow_test.go",
         "android/onceper_test.go",
diff --git a/android/android_test.go b/android/android_test.go
new file mode 100644
index 0000000..46b7054
--- /dev/null
+++ b/android/android_test.go
@@ -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.
+
+package android
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+)
+
+var buildDir string
+
+func setUp() {
+	var err error
+	buildDir, err = ioutil.TempDir("", "soong_android_test")
+	if err != nil {
+		panic(err)
+	}
+}
+
+func tearDown() {
+	os.RemoveAll(buildDir)
+}
+
+func TestMain(m *testing.M) {
+	run := func() int {
+		setUp()
+		defer tearDown()
+
+		return m.Run()
+	}
+
+	os.Exit(run())
+}
diff --git a/android/defaults.go b/android/defaults.go
index d4fbf48..844b4d4 100644
--- a/android/defaults.go
+++ b/android/defaults.go
@@ -80,6 +80,9 @@
 	return d.defaultableProperties
 }
 
+func (d *DefaultsModuleBase) GenerateAndroidBuildActions(ctx ModuleContext) {
+}
+
 func InitDefaultsModule(module DefaultableModule) {
 	module.AddProperties(
 		&hostAndDeviceProperties{},
diff --git a/android/defaults_test.go b/android/defaults_test.go
new file mode 100644
index 0000000..fa26595
--- /dev/null
+++ b/android/defaults_test.go
@@ -0,0 +1,116 @@
+// 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 (
+	"testing"
+
+	"github.com/google/blueprint/proptools"
+)
+
+type defaultsTestProperties struct {
+	Foo []string
+}
+
+type defaultsTestModule struct {
+	ModuleBase
+	DefaultableModuleBase
+	properties defaultsTestProperties
+}
+
+func (d *defaultsTestModule) GenerateAndroidBuildActions(ctx ModuleContext) {
+	ctx.Build(pctx, BuildParams{
+		Rule:   Touch,
+		Output: PathForModuleOut(ctx, "out"),
+	})
+}
+
+func defaultsTestModuleFactory() Module {
+	module := &defaultsTestModule{}
+	module.AddProperties(&module.properties)
+	InitDefaultableModule(module)
+	InitAndroidModule(module)
+	return module
+}
+
+type defaultsTestDefaults struct {
+	ModuleBase
+	DefaultsModuleBase
+}
+
+func defaultsTestDefaultsFactory() Module {
+	defaults := &defaultsTestDefaults{}
+	defaults.AddProperties(&defaultsTestProperties{})
+	InitDefaultsModule(defaults)
+	return defaults
+}
+
+func TestDefaultsAllowMissingDependencies(t *testing.T) {
+	config := TestConfig(buildDir, nil)
+	config.TestProductVariables.Allow_missing_dependencies = proptools.BoolPtr(true)
+
+	ctx := NewTestContext()
+	ctx.SetAllowMissingDependencies(true)
+
+	ctx.RegisterModuleType("test", ModuleFactoryAdaptor(defaultsTestModuleFactory))
+	ctx.RegisterModuleType("defaults", ModuleFactoryAdaptor(defaultsTestDefaultsFactory))
+
+	ctx.PreArchMutators(RegisterDefaultsPreArchMutators)
+
+	ctx.Register()
+
+	bp := `
+		defaults {
+			name: "defaults",
+			defaults: ["missing"],
+			foo: ["defaults"],
+		}
+
+		test {
+			name: "missing_defaults",
+			defaults: ["missing"],
+			foo: ["module"],
+		}
+
+		test {
+			name: "missing_transitive_defaults",
+			defaults: ["defaults"],
+			foo: ["module"],
+		}
+	`
+
+	ctx.MockFileSystem(map[string][]byte{
+		"Android.bp": []byte(bp),
+	})
+
+	_, errs := ctx.ParseFileList(".", []string{"Android.bp"})
+	FailIfErrored(t, errs)
+	_, errs = ctx.PrepareBuildActions(config)
+	FailIfErrored(t, errs)
+
+	missingDefaults := ctx.ModuleForTests("missing_defaults", "").Output("out")
+	missingTransitiveDefaults := ctx.ModuleForTests("missing_transitive_defaults", "").Output("out")
+
+	if missingDefaults.Rule != ErrorRule {
+		t.Errorf("expected missing_defaults rule to be ErrorRule, got %#v", missingDefaults.Rule)
+	}
+
+	if g, w := missingDefaults.Args["error"], "module missing_defaults missing dependencies: missing\n"; g != w {
+		t.Errorf("want error %q, got %q", w, g)
+	}
+
+	// TODO: missing transitive defaults is currently not handled
+	_ = missingTransitiveDefaults
+}
diff --git a/android/module.go b/android/module.go
index 88eba87..03993e5 100644
--- a/android/module.go
+++ b/android/module.go
@@ -56,14 +56,40 @@
 type ModuleBuildParams BuildParams
 
 // BaseModuleContext is the same as blueprint.BaseModuleContext except that Config() returns
-// a Config instead of an interface{}, plus some extra methods that return Android-specific information
+// a Config instead of an interface{}, and some methods have been wrapped to use an android.Module
+// instead of a blueprint.Module, plus some extra methods that return Android-specific information
 // about the current module.
 type BaseModuleContext interface {
+	Module() Module
 	ModuleName() string
 	ModuleDir() string
 	ModuleType() string
 	Config() Config
 
+	OtherModuleName(m blueprint.Module) string
+	OtherModuleDir(m blueprint.Module) string
+	OtherModuleErrorf(m blueprint.Module, fmt string, args ...interface{})
+	OtherModuleDependencyTag(m blueprint.Module) blueprint.DependencyTag
+	OtherModuleExists(name string) bool
+
+	GetDirectDepsWithTag(tag blueprint.DependencyTag) []Module
+	GetDirectDepWithTag(name string, tag blueprint.DependencyTag) blueprint.Module
+	GetDirectDep(name string) (blueprint.Module, blueprint.DependencyTag)
+
+	VisitDirectDepsBlueprint(visit func(blueprint.Module))
+	VisitDirectDeps(visit func(Module))
+	VisitDirectDepsWithTag(tag blueprint.DependencyTag, visit func(Module))
+	VisitDirectDepsIf(pred func(Module) bool, visit func(Module))
+	// Deprecated: use WalkDeps instead to support multiple dependency tags on the same module
+	VisitDepsDepthFirst(visit func(Module))
+	// Deprecated: use WalkDeps instead to support multiple dependency tags on the same module
+	VisitDepsDepthFirstIf(pred func(Module) bool, visit func(Module))
+	WalkDeps(visit func(Module, Module) bool)
+	WalkDepsBlueprint(visit func(blueprint.Module, blueprint.Module) bool)
+	// GetWalkPath is supposed to be called in visit function passed in WalkDeps()
+	// and returns a top-down dependency path from a start module to current child module.
+	GetWalkPath() []Module
+
 	ContainsProperty(name string) bool
 	Errorf(pos scanner.Position, fmt string, args ...interface{})
 	ModuleErrorf(fmt string, args ...interface{})
@@ -76,9 +102,14 @@
 	// file that does not match the pattern is added to a searched directory.
 	GlobWithDeps(pattern string, excludes []string) ([]string, error)
 
+	Glob(globPattern string, excludes []string) Paths
+	GlobFiles(globPattern string, excludes []string) Paths
+
 	Fs() pathtools.FileSystem
 	AddNinjaFileDeps(deps ...string)
 
+	AddMissingDependencies(missingDeps []string)
+
 	Target() Target
 	TargetPrimary() bool
 	MultiTargets() []Target
@@ -114,8 +145,6 @@
 	ExpandSources(srcFiles, excludes []string) Paths
 	ExpandSource(srcFile, prop string) Path
 	ExpandOptionalSource(srcFile *string, prop string) OptionalPath
-	Glob(globPattern string, excludes []string) Paths
-	GlobFiles(globPattern string, excludes []string) Paths
 
 	InstallExecutable(installPath OutputPath, name string, srcPath Path, deps ...Path) OutputPath
 	InstallFile(installPath OutputPath, name string, srcPath Path, deps ...Path) OutputPath
@@ -123,8 +152,6 @@
 	InstallAbsoluteSymlink(installPath OutputPath, name string, absPath string) OutputPath
 	CheckbuildFile(srcPath Path)
 
-	AddMissingDependencies(deps []string)
-
 	InstallInData() bool
 	InstallInSanitizerDir() bool
 	InstallInRecovery() bool
@@ -133,30 +160,8 @@
 	HostRequiredModuleNames() []string
 	TargetRequiredModuleNames() []string
 
-	// android.ModuleContext methods
-	// These are duplicated instead of embedded so that can eventually be wrapped to take an
-	// android.Module instead of a blueprint.Module
-	OtherModuleName(m blueprint.Module) string
-	OtherModuleErrorf(m blueprint.Module, fmt string, args ...interface{})
-	OtherModuleDependencyTag(m blueprint.Module) blueprint.DependencyTag
-
-	GetDirectDepsWithTag(tag blueprint.DependencyTag) []Module
-	GetDirectDepWithTag(name string, tag blueprint.DependencyTag) blueprint.Module
-	GetDirectDep(name string) (blueprint.Module, blueprint.DependencyTag)
-
 	ModuleSubDir() string
 
-	VisitDirectDepsBlueprint(visit func(blueprint.Module))
-	VisitDirectDeps(visit func(Module))
-	VisitDirectDepsWithTag(tag blueprint.DependencyTag, visit func(Module))
-	VisitDirectDepsIf(pred func(Module) bool, visit func(Module))
-	// Deprecated: use WalkDeps instead to support multiple dependency tags on the same module
-	VisitDepsDepthFirst(visit func(Module))
-	// Deprecated: use WalkDeps instead to support multiple dependency tags on the same module
-	VisitDepsDepthFirstIf(pred func(Module) bool, visit func(Module))
-	WalkDeps(visit func(Module, Module) bool)
-	WalkDepsBlueprint(visit func(blueprint.Module, blueprint.Module) bool)
-
 	Variable(pctx PackageContext, name, value string)
 	Rule(pctx PackageContext, name string, params blueprint.RuleParams, argNames ...string) blueprint.Rule
 	// Similar to blueprint.ModuleContext.Build, but takes Paths instead of []string,
@@ -338,6 +343,8 @@
 	SkipInstall bool `blueprint:"mutated"`
 
 	NamespaceExportedToMake bool `blueprint:"mutated"`
+
+	MissingDeps []string `blueprint:"mutated"`
 }
 
 type hostAndDeviceProperties struct {
@@ -837,14 +844,22 @@
 func (m *ModuleBase) GenerateBuildActions(blueprintCtx blueprint.ModuleContext) {
 	ctx := &moduleContext{
 		module:            m.module,
-		ModuleContext:     blueprintCtx,
+		bp:                blueprintCtx,
 		baseModuleContext: m.baseModuleContextFactory(blueprintCtx),
 		installDeps:       m.computeInstallDeps(blueprintCtx),
 		installFiles:      m.installFiles,
-		missingDeps:       blueprintCtx.GetMissingDependencies(),
 		variables:         make(map[string]string),
 	}
 
+	// Temporarily continue to call blueprintCtx.GetMissingDependencies() to maintain the previous behavior of never
+	// reporting missing dependency errors in Blueprint when AllowMissingDependencies == true.
+	// TODO: This will be removed once defaults modules handle missing dependency errors
+	blueprintCtx.GetMissingDependencies()
+
+	// For the final GenerateAndroidBuildActions pass, require that all visited dependencies Soong modules and
+	// are enabled.
+	ctx.baseModuleContext.strictVisitDeps = true
+
 	if ctx.config.captureBuild {
 		ctx.ruleParams = make(map[blueprint.Rule]blueprint.RuleParams)
 	}
@@ -901,6 +916,12 @@
 			noticePath := filepath.Join(ctx.ModuleDir(), notice)
 			m.noticeFile = ExistentPathForSource(ctx, noticePath)
 		}
+	} 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
+		// and report them as an error even when AllowMissingDependencies = true.  Call
+		// ctx.GetMissingDependencies() here to tell blueprint not to handle them.
+		ctx.GetMissingDependencies()
 	}
 
 	if m == ctx.FinalModule().(Module).base() {
@@ -923,15 +944,18 @@
 	debug         bool
 	kind          moduleKind
 	config        Config
+
+	walkPath []Module
+
+	strictVisitDeps bool // If true, enforce that all dependencies are enabled
 }
 
 type moduleContext struct {
-	blueprint.ModuleContext
+	bp blueprint.ModuleContext
 	baseModuleContext
 	installDeps     Paths
 	installFiles    Paths
 	checkbuildFiles Paths
-	missingDeps     []string
 	module          Module
 
 	// For tests
@@ -940,21 +964,16 @@
 	variables   map[string]string
 }
 
-func (m *moduleContext) ninjaError(desc string, outputs []string, err error) {
-	m.ModuleContext.Build(pctx.PackageContext, blueprint.BuildParams{
+func (m *moduleContext) ninjaError(params BuildParams, err error) (PackageContext, BuildParams) {
+	return pctx, BuildParams{
 		Rule:        ErrorRule,
-		Description: desc,
-		Outputs:     outputs,
-		Optional:    true,
+		Description: params.Description,
+		Output:      params.Output,
+		Outputs:     params.Outputs,
 		Args: map[string]string{
 			"error": err.Error(),
 		},
-	})
-	return
-}
-
-func (m *moduleContext) Config() Config {
-	return m.ModuleContext.Config().(Config)
+	}
 }
 
 func (m *moduleContext) ModuleBuild(pctx PackageContext, params ModuleBuildParams) {
@@ -1006,13 +1025,13 @@
 		m.variables[name] = value
 	}
 
-	m.ModuleContext.Variable(pctx.PackageContext, name, value)
+	m.bp.Variable(pctx.PackageContext, name, value)
 }
 
 func (m *moduleContext) Rule(pctx PackageContext, name string, params blueprint.RuleParams,
 	argNames ...string) blueprint.Rule {
 
-	rule := m.ModuleContext.Rule(pctx.PackageContext, name, params, argNames...)
+	rule := m.bp.Rule(pctx.PackageContext, name, params, argNames...)
 
 	if m.config.captureBuild {
 		m.ruleParams[rule] = params
@@ -1022,65 +1041,79 @@
 }
 
 func (m *moduleContext) Build(pctx PackageContext, params BuildParams) {
+	if params.Description != "" {
+		params.Description = "${moduleDesc}" + params.Description + "${moduleDescSuffix}"
+	}
+
+	if missingDeps := m.GetMissingDependencies(); len(missingDeps) > 0 {
+		pctx, params = m.ninjaError(params, fmt.Errorf("module %s missing dependencies: %s\n",
+			m.ModuleName(), strings.Join(missingDeps, ", ")))
+	}
+
 	if m.config.captureBuild {
 		m.buildParams = append(m.buildParams, params)
 	}
 
-	bparams := convertBuildParams(params)
+	m.bp.Build(pctx.PackageContext, convertBuildParams(params))
+}
 
-	if bparams.Description != "" {
-		bparams.Description = "${moduleDesc}" + params.Description + "${moduleDescSuffix}"
-	}
+func (b *baseModuleContext) Module() Module {
+	module, _ := b.BaseModuleContext.Module().(Module)
+	return module
+}
 
-	if m.missingDeps != nil {
-		m.ninjaError(bparams.Description, bparams.Outputs,
-			fmt.Errorf("module %s missing dependencies: %s\n",
-				m.ModuleName(), strings.Join(m.missingDeps, ", ")))
-		return
-	}
-
-	m.ModuleContext.Build(pctx.PackageContext, bparams)
+func (b *baseModuleContext) Config() Config {
+	return b.BaseModuleContext.Config().(Config)
 }
 
 func (m *moduleContext) GetMissingDependencies() []string {
-	return m.missingDeps
+	var missingDeps []string
+	missingDeps = append(missingDeps, m.Module().base().commonProperties.MissingDeps...)
+	missingDeps = append(missingDeps, m.bp.GetMissingDependencies()...)
+	missingDeps = FirstUniqueStrings(missingDeps)
+	return missingDeps
 }
 
-func (m *moduleContext) AddMissingDependencies(deps []string) {
+func (b *baseModuleContext) AddMissingDependencies(deps []string) {
 	if deps != nil {
-		m.missingDeps = append(m.missingDeps, deps...)
-		m.missingDeps = FirstUniqueStrings(m.missingDeps)
+		missingDeps := &b.Module().base().commonProperties.MissingDeps
+		*missingDeps = append(*missingDeps, deps...)
+		*missingDeps = FirstUniqueStrings(*missingDeps)
 	}
 }
 
-func (m *moduleContext) validateAndroidModule(module blueprint.Module) Module {
+func (b *baseModuleContext) validateAndroidModule(module blueprint.Module, strict bool) Module {
 	aModule, _ := module.(Module)
+
+	if !strict {
+		return aModule
+	}
+
 	if aModule == nil {
-		m.ModuleErrorf("module %q not an android module", m.OtherModuleName(aModule))
+		b.ModuleErrorf("module %q not an android module", b.OtherModuleName(module))
 		return nil
 	}
 
 	if !aModule.Enabled() {
-		if m.Config().AllowMissingDependencies() {
-			m.AddMissingDependencies([]string{m.OtherModuleName(aModule)})
+		if b.Config().AllowMissingDependencies() {
+			b.AddMissingDependencies([]string{b.OtherModuleName(aModule)})
 		} else {
-			m.ModuleErrorf("depends on disabled module %q", m.OtherModuleName(aModule))
+			b.ModuleErrorf("depends on disabled module %q", b.OtherModuleName(aModule))
 		}
 		return nil
 	}
-
 	return aModule
 }
 
-func (m *moduleContext) getDirectDepInternal(name string, tag blueprint.DependencyTag) (blueprint.Module, blueprint.DependencyTag) {
+func (b *baseModuleContext) getDirectDepInternal(name string, tag blueprint.DependencyTag) (blueprint.Module, blueprint.DependencyTag) {
 	type dep struct {
 		mod blueprint.Module
 		tag blueprint.DependencyTag
 	}
 	var deps []dep
-	m.VisitDirectDepsBlueprint(func(module blueprint.Module) {
+	b.VisitDirectDepsBlueprint(func(module blueprint.Module) {
 		if aModule, _ := module.(Module); aModule != nil && aModule.base().BaseModuleName() == name {
-			returnedTag := m.ModuleContext.OtherModuleDependencyTag(aModule)
+			returnedTag := b.BaseModuleContext.OtherModuleDependencyTag(aModule)
 			if tag == nil || returnedTag == tag {
 				deps = append(deps, dep{aModule, returnedTag})
 			}
@@ -1090,17 +1123,17 @@
 		return deps[0].mod, deps[0].tag
 	} else if len(deps) >= 2 {
 		panic(fmt.Errorf("Multiple dependencies having same BaseModuleName() %q found from %q",
-			name, m.ModuleName()))
+			name, b.ModuleName()))
 	} else {
 		return nil, nil
 	}
 }
 
-func (m *moduleContext) GetDirectDepsWithTag(tag blueprint.DependencyTag) []Module {
+func (b *baseModuleContext) GetDirectDepsWithTag(tag blueprint.DependencyTag) []Module {
 	var deps []Module
-	m.VisitDirectDepsBlueprint(func(module blueprint.Module) {
+	b.VisitDirectDepsBlueprint(func(module blueprint.Module) {
 		if aModule, _ := module.(Module); aModule != nil {
-			if m.ModuleContext.OtherModuleDependencyTag(aModule) == tag {
+			if b.BaseModuleContext.OtherModuleDependencyTag(aModule) == tag {
 				deps = append(deps, aModule)
 			}
 		}
@@ -1113,37 +1146,37 @@
 	return module
 }
 
-func (m *moduleContext) GetDirectDep(name string) (blueprint.Module, blueprint.DependencyTag) {
-	return m.getDirectDepInternal(name, nil)
+func (b *baseModuleContext) GetDirectDep(name string) (blueprint.Module, blueprint.DependencyTag) {
+	return b.getDirectDepInternal(name, nil)
 }
 
-func (m *moduleContext) VisitDirectDepsBlueprint(visit func(blueprint.Module)) {
-	m.ModuleContext.VisitDirectDeps(visit)
+func (b *baseModuleContext) VisitDirectDepsBlueprint(visit func(blueprint.Module)) {
+	b.BaseModuleContext.VisitDirectDeps(visit)
 }
 
-func (m *moduleContext) VisitDirectDeps(visit func(Module)) {
-	m.ModuleContext.VisitDirectDeps(func(module blueprint.Module) {
-		if aModule := m.validateAndroidModule(module); aModule != nil {
+func (b *baseModuleContext) VisitDirectDeps(visit func(Module)) {
+	b.BaseModuleContext.VisitDirectDeps(func(module blueprint.Module) {
+		if aModule := b.validateAndroidModule(module, b.strictVisitDeps); aModule != nil {
 			visit(aModule)
 		}
 	})
 }
 
-func (m *moduleContext) VisitDirectDepsWithTag(tag blueprint.DependencyTag, visit func(Module)) {
-	m.ModuleContext.VisitDirectDeps(func(module blueprint.Module) {
-		if aModule := m.validateAndroidModule(module); aModule != nil {
-			if m.ModuleContext.OtherModuleDependencyTag(aModule) == tag {
+func (b *baseModuleContext) VisitDirectDepsWithTag(tag blueprint.DependencyTag, visit func(Module)) {
+	b.BaseModuleContext.VisitDirectDeps(func(module blueprint.Module) {
+		if aModule := b.validateAndroidModule(module, b.strictVisitDeps); aModule != nil {
+			if b.BaseModuleContext.OtherModuleDependencyTag(aModule) == tag {
 				visit(aModule)
 			}
 		}
 	})
 }
 
-func (m *moduleContext) VisitDirectDepsIf(pred func(Module) bool, visit func(Module)) {
-	m.ModuleContext.VisitDirectDepsIf(
+func (b *baseModuleContext) VisitDirectDepsIf(pred func(Module) bool, visit func(Module)) {
+	b.BaseModuleContext.VisitDirectDepsIf(
 		// pred
 		func(module blueprint.Module) bool {
-			if aModule := m.validateAndroidModule(module); aModule != nil {
+			if aModule := b.validateAndroidModule(module, b.strictVisitDeps); aModule != nil {
 				return pred(aModule)
 			} else {
 				return false
@@ -1155,19 +1188,19 @@
 		})
 }
 
-func (m *moduleContext) VisitDepsDepthFirst(visit func(Module)) {
-	m.ModuleContext.VisitDepsDepthFirst(func(module blueprint.Module) {
-		if aModule := m.validateAndroidModule(module); aModule != nil {
+func (b *baseModuleContext) VisitDepsDepthFirst(visit func(Module)) {
+	b.BaseModuleContext.VisitDepsDepthFirst(func(module blueprint.Module) {
+		if aModule := b.validateAndroidModule(module, b.strictVisitDeps); aModule != nil {
 			visit(aModule)
 		}
 	})
 }
 
-func (m *moduleContext) VisitDepsDepthFirstIf(pred func(Module) bool, visit func(Module)) {
-	m.ModuleContext.VisitDepsDepthFirstIf(
+func (b *baseModuleContext) VisitDepsDepthFirstIf(pred func(Module) bool, visit func(Module)) {
+	b.BaseModuleContext.VisitDepsDepthFirstIf(
 		// pred
 		func(module blueprint.Module) bool {
-			if aModule := m.validateAndroidModule(module); aModule != nil {
+			if aModule := b.validateAndroidModule(module, b.strictVisitDeps); aModule != nil {
 				return pred(aModule)
 			} else {
 				return false
@@ -1179,15 +1212,21 @@
 		})
 }
 
-func (m *moduleContext) WalkDepsBlueprint(visit func(blueprint.Module, blueprint.Module) bool) {
-	m.ModuleContext.WalkDeps(visit)
+func (b *baseModuleContext) WalkDepsBlueprint(visit func(blueprint.Module, blueprint.Module) bool) {
+	b.BaseModuleContext.WalkDeps(visit)
 }
 
-func (m *moduleContext) WalkDeps(visit func(Module, Module) bool) {
-	m.ModuleContext.WalkDeps(func(child, parent blueprint.Module) bool {
-		childAndroidModule := m.validateAndroidModule(child)
-		parentAndroidModule := m.validateAndroidModule(parent)
+func (b *baseModuleContext) WalkDeps(visit func(Module, Module) bool) {
+	b.walkPath = []Module{b.Module()}
+	b.BaseModuleContext.WalkDeps(func(child, parent blueprint.Module) bool {
+		childAndroidModule, _ := child.(Module)
+		parentAndroidModule, _ := parent.(Module)
 		if childAndroidModule != nil && parentAndroidModule != nil {
+			// record walkPath before visit
+			for b.walkPath[len(b.walkPath)-1] != parentAndroidModule {
+				b.walkPath = b.walkPath[0 : len(b.walkPath)-1]
+			}
+			b.walkPath = append(b.walkPath, childAndroidModule)
 			return visit(childAndroidModule, parentAndroidModule)
 		} else {
 			return false
@@ -1195,18 +1234,26 @@
 	})
 }
 
+func (b *baseModuleContext) GetWalkPath() []Module {
+	return b.walkPath
+}
+
 func (m *moduleContext) VisitAllModuleVariants(visit func(Module)) {
-	m.ModuleContext.VisitAllModuleVariants(func(module blueprint.Module) {
+	m.bp.VisitAllModuleVariants(func(module blueprint.Module) {
 		visit(module.(Module))
 	})
 }
 
 func (m *moduleContext) PrimaryModule() Module {
-	return m.ModuleContext.PrimaryModule().(Module)
+	return m.bp.PrimaryModule().(Module)
 }
 
 func (m *moduleContext) FinalModule() Module {
-	return m.ModuleContext.FinalModule().(Module)
+	return m.bp.FinalModule().(Module)
+}
+
+func (m *moduleContext) ModuleSubDir() string {
+	return m.bp.ModuleSubDir()
 }
 
 func (b *baseModuleContext) Target() Target {
@@ -1584,20 +1631,20 @@
 	return m.module.base().commonProperties.Target_required
 }
 
-func (m *moduleContext) Glob(globPattern string, excludes []string) Paths {
-	ret, err := m.GlobWithDeps(globPattern, excludes)
+func (b *baseModuleContext) Glob(globPattern string, excludes []string) Paths {
+	ret, err := b.GlobWithDeps(globPattern, excludes)
 	if err != nil {
-		m.ModuleErrorf("glob: %s", err.Error())
+		b.ModuleErrorf("glob: %s", err.Error())
 	}
-	return pathsForModuleSrcFromFullPath(m, ret, true)
+	return pathsForModuleSrcFromFullPath(b, ret, true)
 }
 
-func (m *moduleContext) GlobFiles(globPattern string, excludes []string) Paths {
-	ret, err := m.GlobWithDeps(globPattern, excludes)
+func (b *baseModuleContext) GlobFiles(globPattern string, excludes []string) Paths {
+	ret, err := b.GlobWithDeps(globPattern, excludes)
 	if err != nil {
-		m.ModuleErrorf("glob: %s", err.Error())
+		b.ModuleErrorf("glob: %s", err.Error())
 	}
-	return pathsForModuleSrcFromFullPath(m, ret, false)
+	return pathsForModuleSrcFromFullPath(b, ret, false)
 }
 
 func init() {
diff --git a/android/mutator.go b/android/mutator.go
index cd0d152..081c2b2 100644
--- a/android/mutator.go
+++ b/android/mutator.go
@@ -115,35 +115,14 @@
 type TopDownMutatorContext interface {
 	BaseModuleContext
 
-	OtherModuleExists(name string) bool
 	Rename(name string)
-	Module() Module
-
-	OtherModuleName(m blueprint.Module) string
-	OtherModuleDir(m blueprint.Module) string
-	OtherModuleErrorf(m blueprint.Module, fmt string, args ...interface{})
-	OtherModuleDependencyTag(m blueprint.Module) blueprint.DependencyTag
 
 	CreateModule(blueprint.ModuleFactory, ...interface{})
-
-	GetDirectDepWithTag(name string, tag blueprint.DependencyTag) blueprint.Module
-	GetDirectDep(name string) (blueprint.Module, blueprint.DependencyTag)
-
-	VisitDirectDeps(visit func(Module))
-	VisitDirectDepsWithTag(tag blueprint.DependencyTag, visit func(Module))
-	VisitDirectDepsIf(pred func(Module) bool, visit func(Module))
-	VisitDepsDepthFirst(visit func(Module))
-	VisitDepsDepthFirstIf(pred func(Module) bool, visit func(Module))
-	WalkDeps(visit func(Module, Module) bool)
-	// GetWalkPath is supposed to be called in visit function passed in WalkDeps()
-	// and returns a top-down dependency path from a start module to current child module.
-	GetWalkPath() []Module
 }
 
 type topDownMutatorContext struct {
-	blueprint.TopDownMutatorContext
+	bp blueprint.TopDownMutatorContext
 	baseModuleContext
-	walkPath []Module
 }
 
 type BottomUpMutator func(BottomUpMutatorContext)
@@ -151,9 +130,7 @@
 type BottomUpMutatorContext interface {
 	BaseModuleContext
 
-	OtherModuleExists(name string) bool
 	Rename(name string)
-	Module() blueprint.Module
 
 	AddDependency(module blueprint.Module, tag blueprint.DependencyTag, name ...string)
 	AddReverseDependency(module blueprint.Module, tag blueprint.DependencyTag, name string)
@@ -167,7 +144,7 @@
 }
 
 type bottomUpMutatorContext struct {
-	blueprint.BottomUpMutatorContext
+	bp blueprint.BottomUpMutatorContext
 	baseModuleContext
 }
 
@@ -175,8 +152,8 @@
 	f := func(ctx blueprint.BottomUpMutatorContext) {
 		if a, ok := ctx.Module().(Module); ok {
 			actx := &bottomUpMutatorContext{
-				BottomUpMutatorContext: ctx,
-				baseModuleContext:      a.base().baseModuleContextFactory(ctx),
+				bp:                ctx,
+				baseModuleContext: a.base().baseModuleContextFactory(ctx),
 			}
 			m(actx)
 		}
@@ -190,8 +167,8 @@
 	f := func(ctx blueprint.TopDownMutatorContext) {
 		if a, ok := ctx.Module().(Module); ok {
 			actx := &topDownMutatorContext{
-				TopDownMutatorContext: ctx,
-				baseModuleContext:     a.base().baseModuleContextFactory(ctx),
+				bp:                ctx,
+				baseModuleContext: a.base().baseModuleContextFactory(ctx),
 			}
 			m(actx)
 		}
@@ -216,99 +193,6 @@
 	}
 }
 
-func (t *topDownMutatorContext) Config() Config {
-	return t.config
-}
-
-func (b *bottomUpMutatorContext) Config() Config {
-	return b.config
-}
-
-func (t *topDownMutatorContext) Module() Module {
-	module, _ := t.TopDownMutatorContext.Module().(Module)
-	return module
-}
-
-func (t *topDownMutatorContext) VisitDirectDeps(visit func(Module)) {
-	t.TopDownMutatorContext.VisitDirectDeps(func(module blueprint.Module) {
-		if aModule, _ := module.(Module); aModule != nil {
-			visit(aModule)
-		}
-	})
-}
-
-func (t *topDownMutatorContext) VisitDirectDepsWithTag(tag blueprint.DependencyTag, visit func(Module)) {
-	t.TopDownMutatorContext.VisitDirectDeps(func(module blueprint.Module) {
-		if aModule, _ := module.(Module); aModule != nil {
-			if t.TopDownMutatorContext.OtherModuleDependencyTag(aModule) == tag {
-				visit(aModule)
-			}
-		}
-	})
-}
-
-func (t *topDownMutatorContext) VisitDirectDepsIf(pred func(Module) bool, visit func(Module)) {
-	t.TopDownMutatorContext.VisitDirectDepsIf(
-		// pred
-		func(module blueprint.Module) bool {
-			if aModule, _ := module.(Module); aModule != nil {
-				return pred(aModule)
-			} else {
-				return false
-			}
-		},
-		// visit
-		func(module blueprint.Module) {
-			visit(module.(Module))
-		})
-}
-
-func (t *topDownMutatorContext) VisitDepsDepthFirst(visit func(Module)) {
-	t.TopDownMutatorContext.VisitDepsDepthFirst(func(module blueprint.Module) {
-		if aModule, _ := module.(Module); aModule != nil {
-			visit(aModule)
-		}
-	})
-}
-
-func (t *topDownMutatorContext) VisitDepsDepthFirstIf(pred func(Module) bool, visit func(Module)) {
-	t.TopDownMutatorContext.VisitDepsDepthFirstIf(
-		// pred
-		func(module blueprint.Module) bool {
-			if aModule, _ := module.(Module); aModule != nil {
-				return pred(aModule)
-			} else {
-				return false
-			}
-		},
-		// visit
-		func(module blueprint.Module) {
-			visit(module.(Module))
-		})
-}
-
-func (t *topDownMutatorContext) WalkDeps(visit func(Module, Module) bool) {
-	t.walkPath = []Module{t.Module()}
-	t.TopDownMutatorContext.WalkDeps(func(child, parent blueprint.Module) bool {
-		childAndroidModule, _ := child.(Module)
-		parentAndroidModule, _ := parent.(Module)
-		if childAndroidModule != nil && parentAndroidModule != nil {
-			// record walkPath before visit
-			for t.walkPath[len(t.walkPath)-1] != parentAndroidModule {
-				t.walkPath = t.walkPath[0 : len(t.walkPath)-1]
-			}
-			t.walkPath = append(t.walkPath, childAndroidModule)
-			return visit(childAndroidModule, parentAndroidModule)
-		} else {
-			return false
-		}
-	})
-}
-
-func (t *topDownMutatorContext) GetWalkPath() []Module {
-	return t.walkPath
-}
-
 func (t *topDownMutatorContext) AppendProperties(props ...interface{}) {
 	for _, p := range props {
 		err := proptools.AppendMatchingProperties(t.Module().base().customizableProperties,
@@ -336,3 +220,61 @@
 		}
 	}
 }
+
+// android.topDownMutatorContext either has to embed blueprint.TopDownMutatorContext, in which case every method that
+// has an overridden version in android.BaseModuleContext has to be manually forwarded to BaseModuleContext to avoid
+// ambiguous method errors, or it has to store a blueprint.TopDownMutatorContext non-embedded, in which case every
+// non-overridden method has to be forwarded.  There are fewer non-overridden methods, so use the latter.  The following
+// methods forward to the identical blueprint versions for topDownMutatorContext and bottomUpMutatorContext.
+
+func (t *topDownMutatorContext) Rename(name string) {
+	t.bp.Rename(name)
+}
+
+func (t *topDownMutatorContext) CreateModule(factory blueprint.ModuleFactory, props ...interface{}) {
+	t.bp.CreateModule(factory, props...)
+}
+
+func (b *bottomUpMutatorContext) Rename(name string) {
+	b.bp.Rename(name)
+}
+
+func (b *bottomUpMutatorContext) AddDependency(module blueprint.Module, tag blueprint.DependencyTag, name ...string) {
+	b.bp.AddDependency(module, tag, name...)
+}
+
+func (b *bottomUpMutatorContext) AddReverseDependency(module blueprint.Module, tag blueprint.DependencyTag, name string) {
+	b.bp.AddReverseDependency(module, tag, name)
+}
+
+func (b *bottomUpMutatorContext) CreateVariations(variations ...string) []blueprint.Module {
+	return b.bp.CreateVariations(variations...)
+}
+
+func (b *bottomUpMutatorContext) CreateLocalVariations(variations ...string) []blueprint.Module {
+	return b.bp.CreateLocalVariations(variations...)
+}
+
+func (b *bottomUpMutatorContext) SetDependencyVariation(variation string) {
+	b.bp.SetDependencyVariation(variation)
+}
+
+func (b *bottomUpMutatorContext) AddVariationDependencies(variations []blueprint.Variation, tag blueprint.DependencyTag,
+	names ...string) {
+
+	b.bp.AddVariationDependencies(variations, tag, names...)
+}
+
+func (b *bottomUpMutatorContext) AddFarVariationDependencies(variations []blueprint.Variation,
+	tag blueprint.DependencyTag, names ...string) {
+
+	b.bp.AddFarVariationDependencies(variations, tag, names...)
+}
+
+func (b *bottomUpMutatorContext) AddInterVariantDependency(tag blueprint.DependencyTag, from, to blueprint.Module) {
+	b.bp.AddInterVariantDependency(tag, from, to)
+}
+
+func (b *bottomUpMutatorContext) ReplaceDependencies(name string) {
+	b.bp.ReplaceDependencies(name)
+}
diff --git a/android/mutator_test.go b/android/mutator_test.go
new file mode 100644
index 0000000..4cef400
--- /dev/null
+++ b/android/mutator_test.go
@@ -0,0 +1,99 @@
+// Copyright 2015 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package android
+
+import (
+	"io/ioutil"
+	"os"
+	"reflect"
+	"testing"
+
+	"github.com/google/blueprint/proptools"
+)
+
+type mutatorTestModule struct {
+	ModuleBase
+	props struct {
+	}
+
+	missingDeps []string
+}
+
+func mutatorTestModuleFactory() Module {
+	module := &mutatorTestModule{}
+	module.AddProperties(&module.props)
+	InitAndroidModule(module)
+	return module
+}
+
+func (m *mutatorTestModule) GenerateAndroidBuildActions(ctx ModuleContext) {
+	ctx.Build(pctx, BuildParams{
+		Rule:   Touch,
+		Output: PathForModuleOut(ctx, "output"),
+	})
+
+	m.missingDeps = ctx.GetMissingDependencies()
+}
+
+func (m *mutatorTestModule) DepsMutator(ctx BottomUpMutatorContext) {
+	ctx.AddDependency(ctx.Module(), nil, "regular_missing_dep")
+}
+
+func addMissingDependenciesMutator(ctx TopDownMutatorContext) {
+	ctx.AddMissingDependencies([]string{"added_missing_dep"})
+}
+
+func TestMutatorAddMissingDependencies(t *testing.T) {
+	buildDir, err := ioutil.TempDir("", "soong_mutator_test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(buildDir)
+
+	config := TestConfig(buildDir, nil)
+	config.TestProductVariables.Allow_missing_dependencies = proptools.BoolPtr(true)
+
+	ctx := NewTestContext()
+	ctx.SetAllowMissingDependencies(true)
+
+	ctx.RegisterModuleType("test", ModuleFactoryAdaptor(mutatorTestModuleFactory))
+	ctx.PreDepsMutators(func(ctx RegisterMutatorsContext) {
+		ctx.TopDown("add_missing_dependencies", addMissingDependenciesMutator)
+	})
+
+	bp := `
+		test {
+			name: "foo",
+		}
+	`
+
+	mockFS := map[string][]byte{
+		"Android.bp": []byte(bp),
+	}
+
+	ctx.MockFileSystem(mockFS)
+
+	ctx.Register()
+	_, errs := ctx.ParseFileList(".", []string{"Android.bp"})
+	FailIfErrored(t, errs)
+	_, errs = ctx.PrepareBuildActions(config)
+	FailIfErrored(t, errs)
+
+	foo := ctx.ModuleForTests("foo", "").Module().(*mutatorTestModule)
+
+	if g, w := foo.missingDeps, []string{"added_missing_dep", "regular_missing_dep"}; !reflect.DeepEqual(g, w) {
+		t.Errorf("want foo missing deps %q, got %q", w, g)
+	}
+}
diff --git a/android/namespace_test.go b/android/namespace_test.go
index 9a791a5..51a0af2 100644
--- a/android/namespace_test.go
+++ b/android/namespace_test.go
@@ -16,8 +16,6 @@
 
 import (
 	"errors"
-	"io/ioutil"
-	"os"
 	"path/filepath"
 	"reflect"
 	"testing"
@@ -613,12 +611,6 @@
 }
 
 func setupTestFromFiles(bps map[string][]byte) (ctx *TestContext, errs []error) {
-	buildDir, err := ioutil.TempDir("", "soong_namespace_test")
-	if err != nil {
-		return nil, []error{err}
-	}
-	defer os.RemoveAll(buildDir)
-
 	config := TestConfig(buildDir, nil)
 
 	ctx = NewTestContext()
diff --git a/android/neverallow_test.go b/android/neverallow_test.go
index c60de21..40ccf14 100644
--- a/android/neverallow_test.go
+++ b/android/neverallow_test.go
@@ -15,8 +15,6 @@
 package android
 
 import (
-	"io/ioutil"
-	"os"
 	"testing"
 )
 
@@ -183,12 +181,6 @@
 }
 
 func TestNeverallow(t *testing.T) {
-	buildDir, err := ioutil.TempDir("", "soong_neverallow_test")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(buildDir)
-
 	config := TestConfig(buildDir, nil)
 
 	for _, test := range neverallowTests {
diff --git a/android/paths.go b/android/paths.go
index 52d22d5..20b8b82 100644
--- a/android/paths.go
+++ b/android/paths.go
@@ -367,7 +367,7 @@
 // each string. If incDirs is false, strip paths with a trailing '/' from the list.
 // It intended for use in globs that only list files that exist, so it allows '$' in
 // filenames.
-func pathsForModuleSrcFromFullPath(ctx ModuleContext, paths []string, incDirs bool) Paths {
+func pathsForModuleSrcFromFullPath(ctx BaseModuleContext, paths []string, incDirs bool) Paths {
 	prefix := filepath.Join(ctx.Config().srcDir, ctx.ModuleDir()) + "/"
 	if prefix == "./" {
 		prefix = ""
diff --git a/android/paths_test.go b/android/paths_test.go
index 78cfbbe..7bcfe41 100644
--- a/android/paths_test.go
+++ b/android/paths_test.go
@@ -17,8 +17,6 @@
 import (
 	"errors"
 	"fmt"
-	"io/ioutil"
-	"os"
 	"reflect"
 	"strings"
 	"testing"
@@ -758,6 +756,11 @@
 	if !p.props.Module_handles_missing_deps {
 		p.missingDeps = ctx.GetMissingDependencies()
 	}
+
+	ctx.Build(pctx, BuildParams{
+		Rule:   Touch,
+		Output: PathForModuleOut(ctx, "output"),
+	})
 }
 
 type pathForModuleSrcOutputFileProviderModule struct {
@@ -875,12 +878,6 @@
 }
 
 func TestPathsForModuleSrc(t *testing.T) {
-	buildDir, err := ioutil.TempDir("", "soong_paths_for_module_src_test")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(buildDir)
-
 	tests := []pathForModuleSrcTestCase{
 		{
 			name: "path",
@@ -961,12 +958,6 @@
 }
 
 func TestPathForModuleSrc(t *testing.T) {
-	buildDir, err := ioutil.TempDir("", "soong_path_for_module_src_test")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(buildDir)
-
 	tests := []pathForModuleSrcTestCase{
 		{
 			name: "path",
@@ -1034,12 +1025,6 @@
 }
 
 func TestPathsForModuleSrc_AllowMissingDependencies(t *testing.T) {
-	buildDir, err := ioutil.TempDir("", "soong_paths_for_module_src_allow_missing_dependencies_test")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(buildDir)
-
 	config := TestConfig(buildDir, nil)
 	config.TestProductVariables.Allow_missing_dependencies = proptools.BoolPtr(true)
 
diff --git a/android/prebuilt_etc_test.go b/android/prebuilt_etc_test.go
index d977c30..0a2c7a4 100644
--- a/android/prebuilt_etc_test.go
+++ b/android/prebuilt_etc_test.go
@@ -15,16 +15,13 @@
 package android
 
 import (
-	"io/ioutil"
-	"os"
 	"path/filepath"
 	"reflect"
 	"testing"
 )
 
 func testPrebuiltEtc(t *testing.T, bp string) (*TestContext, Config) {
-	config, buildDir := setUp(t)
-	defer tearDown(buildDir)
+	config := TestArchConfig(buildDir, nil)
 	ctx := NewTestArchContext()
 	ctx.RegisterModuleType("prebuilt_etc", ModuleFactoryAdaptor(PrebuiltEtcFactory))
 	ctx.RegisterModuleType("prebuilt_etc_host", ModuleFactoryAdaptor(PrebuiltEtcHostFactory))
@@ -51,20 +48,6 @@
 	return ctx, config
 }
 
-func setUp(t *testing.T) (config Config, buildDir string) {
-	buildDir, err := ioutil.TempDir("", "soong_prebuilt_etc_test")
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	config = TestArchConfig(buildDir, nil)
-	return
-}
-
-func tearDown(buildDir string) {
-	os.RemoveAll(buildDir)
-}
-
 func TestPrebuiltEtcVariants(t *testing.T) {
 	ctx, _ := testPrebuiltEtc(t, `
 		prebuilt_etc {
diff --git a/android/prebuilt_test.go b/android/prebuilt_test.go
index a5b85c8..0a18e2c 100644
--- a/android/prebuilt_test.go
+++ b/android/prebuilt_test.go
@@ -16,8 +16,6 @@
 
 import (
 	"fmt"
-	"io/ioutil"
-	"os"
 	"testing"
 
 	"github.com/google/blueprint"
@@ -127,12 +125,6 @@
 }
 
 func TestPrebuilts(t *testing.T) {
-	buildDir, err := ioutil.TempDir("", "soong_prebuilt_test")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(buildDir)
-
 	config := TestConfig(buildDir, nil)
 
 	for _, test := range prebuiltsTests {
diff --git a/android/rule_builder_test.go b/android/rule_builder_test.go
index df0f256..cfbc2ab 100644
--- a/android/rule_builder_test.go
+++ b/android/rule_builder_test.go
@@ -16,8 +16,6 @@
 
 import (
 	"fmt"
-	"io/ioutil"
-	"os"
 	"path/filepath"
 	"reflect"
 	"strings"
@@ -418,12 +416,6 @@
 }
 
 func TestRuleBuilder_Build(t *testing.T) {
-	buildDir, err := ioutil.TempDir("", "soong_test_rule_builder")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(buildDir)
-
 	bp := `
 		rule_builder_test {
 			name: "foo",
diff --git a/android/sh_binary_test.go b/android/sh_binary_test.go
index becb35a..c99e18c 100644
--- a/android/sh_binary_test.go
+++ b/android/sh_binary_test.go
@@ -1,19 +1,11 @@
 package android
 
 import (
-	"io/ioutil"
-	"os"
 	"reflect"
 	"testing"
 )
 
 func testShBinary(t *testing.T, bp string) (*TestContext, Config) {
-	buildDir, err := ioutil.TempDir("", "soong_sh_binary_test")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(buildDir)
-
 	config := TestArchConfig(buildDir, nil)
 
 	ctx := NewTestArchContext()
diff --git a/android/testing.go b/android/testing.go
index c0db75e..44bee4b 100644
--- a/android/testing.go
+++ b/android/testing.go
@@ -179,7 +179,7 @@
 
 func maybeBuildParamsFromDescription(provider testBuildProvider, desc string) TestingBuildParams {
 	for _, p := range provider.BuildParamsForTests() {
-		if p.Description == desc {
+		if strings.Contains(p.Description, desc) {
 			return newTestingBuildParams(provider, p)
 		}
 	}
diff --git a/android/visibility_test.go b/android/visibility_test.go
index 09c5b1b..1a51495 100644
--- a/android/visibility_test.go
+++ b/android/visibility_test.go
@@ -1,8 +1,6 @@
 package android
 
 import (
-	"io/ioutil"
-	"os"
 	"testing"
 
 	"github.com/google/blueprint"
@@ -663,12 +661,6 @@
 }
 
 func TestVisibility(t *testing.T) {
-	buildDir, err := ioutil.TempDir("", "soong_neverallow_test")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(buildDir)
-
 	for _, test := range visibilityTests {
 		t.Run(test.name, func(t *testing.T) {
 			_, errs := testVisibility(buildDir, test.fs)
@@ -759,6 +751,3 @@
 	InitDefaultsModule(m)
 	return m
 }
-
-func (*mockDefaults) GenerateAndroidBuildActions(ctx ModuleContext) {
-}
diff --git a/android/vts_config_test.go b/android/vts_config_test.go
index 7d4c9b1..142b2f5 100644
--- a/android/vts_config_test.go
+++ b/android/vts_config_test.go
@@ -15,19 +15,11 @@
 package android
 
 import (
-	"io/ioutil"
-	"os"
 	"testing"
 )
 
 func testVtsConfig(test *testing.T, bpFileContents string) *TestContext {
-	buildDir, err := ioutil.TempDir("", "soong_vts_config_test")
-	if err != nil {
-		test.Fatal(err)
-	}
-
 	config := TestArchConfig(buildDir, nil)
-	defer func() { os.RemoveAll(buildDir) }()
 
 	ctx := NewTestArchContext()
 	ctx.RegisterModuleType("vts_config", ModuleFactoryAdaptor(VtsConfigFactory))
diff --git a/apex/apex.go b/apex/apex.go
index 41a21c9..11b433c 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -1295,9 +1295,6 @@
 	android.DefaultsModuleBase
 }
 
-func (*Defaults) GenerateAndroidBuildActions(ctx android.ModuleContext) {
-}
-
 func defaultsFactory() android.Module {
 	return DefaultsFactory()
 }
diff --git a/cc/cc.go b/cc/cc.go
index 26d3d98..53ec899 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -2060,9 +2060,6 @@
 	android.ApexModuleBase
 }
 
-func (*Defaults) GenerateAndroidBuildActions(ctx android.ModuleContext) {
-}
-
 // cc_defaults provides a set of properties that can be inherited by other cc
 // modules. A module can use the properties from a cc_defaults using
 // `defaults: ["<:default_module_name>"]`. Properties of both modules are
diff --git a/genrule/genrule.go b/genrule/genrule.go
index 34adbc0..b0657ff 100644
--- a/genrule/genrule.go
+++ b/genrule/genrule.go
@@ -583,9 +583,6 @@
 	android.DefaultsModuleBase
 }
 
-func (*Defaults) GenerateAndroidBuildActions(ctx android.ModuleContext) {
-}
-
 func defaultsFactory() android.Module {
 	return DefaultsFactory()
 }
diff --git a/java/droiddoc.go b/java/droiddoc.go
index d88effd..992c8b5 100644
--- a/java/droiddoc.go
+++ b/java/droiddoc.go
@@ -1808,9 +1808,6 @@
 	android.DefaultsModuleBase
 }
 
-func (*DocDefaults) GenerateAndroidBuildActions(ctx android.ModuleContext) {
-}
-
 func DocDefaultsFactory() android.Module {
 	module := &DocDefaults{}
 
diff --git a/java/java.go b/java/java.go
index fee262d..a1addb3 100644
--- a/java/java.go
+++ b/java/java.go
@@ -2131,9 +2131,6 @@
 	android.DefaultsModuleBase
 }
 
-func (*Defaults) GenerateAndroidBuildActions(ctx android.ModuleContext) {
-}
-
 // java_defaults provides a set of properties that can be inherited by other java or android modules.
 //
 // A module can use the properties from a java_defaults module using `defaults: ["defaults_module_name"]`.  Each