diff --git a/android/Android.bp b/android/Android.bp
index efa70a9..eabb137 100644
--- a/android/Android.bp
+++ b/android/Android.bp
@@ -21,6 +21,7 @@
         "bazel_handler.go",
         "config.go",
         "csuite_config.go",
+        "deapexer.go",
         "defaults.go",
         "defs.go",
         "depset_generic.go",
diff --git a/android/apex.go b/android/apex.go
index 47d14cc..31c62e9 100644
--- a/android/apex.go
+++ b/android/apex.go
@@ -64,6 +64,14 @@
 	// module is part of. The ApexContents gives information about which modules the apexBundle
 	// has and whether a module became part of the apexBundle via a direct dependency or not.
 	ApexContents []*ApexContents
+
+	// True if this is for a prebuilt_apex.
+	//
+	// If true then this will customize the apex processing to make it suitable for handling
+	// prebuilt_apex, e.g. it will prevent ApexInfos from being merged together.
+	//
+	// See Prebuilt.ApexInfoMutator for more information.
+	ForPrebuiltApex bool
 }
 
 var ApexInfoProvider = blueprint.NewMutatorProvider(ApexInfo{}, "apex")
@@ -412,6 +420,16 @@
 	sort.Sort(byApexName(apexInfos))
 	seen := make(map[string]int)
 	for _, apexInfo := range apexInfos {
+		// If this is for a prebuilt apex then use the actual name of the apex variation to prevent this
+		// from being merged with other ApexInfo. See Prebuilt.ApexInfoMutator for more information.
+		if apexInfo.ForPrebuiltApex {
+			merged = append(merged, apexInfo)
+			continue
+		}
+
+		// Merge the ApexInfo together. If a compatible ApexInfo exists then merge the information from
+		// this one into it, otherwise create a new merged ApexInfo from this one and save it away so
+		// other ApexInfo instances can be merged into it.
 		apexName := apexInfo.ApexVariationName
 		mergedName := apexInfo.mergedName(ctx)
 		if index, exists := seen[mergedName]; exists {
@@ -582,10 +600,14 @@
 // apexContents, and modules in that apex have a provider containing the apexContents of each
 // apexBundle they are part of.
 type ApexContents struct {
-	// map from a module name to its membership to this apexBUndle
+	// map from a module name to its membership in this apexBundle
 	contents map[string]ApexMembership
 }
 
+// NewApexContents creates and initializes an ApexContents that is suitable
+// for use with an apex module.
+// * contents is a map from a module name to information about its membership within
+//   the apex.
 func NewApexContents(contents map[string]ApexMembership) *ApexContents {
 	return &ApexContents{
 		contents: contents,
diff --git a/android/apex_test.go b/android/apex_test.go
index 512b50f..1f786e6 100644
--- a/android/apex_test.go
+++ b/android/apex_test.go
@@ -20,6 +20,10 @@
 )
 
 func Test_mergeApexVariations(t *testing.T) {
+	const (
+		ForPrebuiltApex    = true
+		NotForPrebuiltApex = false
+	)
 	tests := []struct {
 		name        string
 		in          []ApexInfo
@@ -29,10 +33,10 @@
 		{
 			name: "single",
 			in: []ApexInfo{
-				{"foo", "current", false, nil, []string{"foo"}, nil},
+				{"foo", "current", false, nil, []string{"foo"}, nil, NotForPrebuiltApex},
 			},
 			wantMerged: []ApexInfo{
-				{"apex10000", "current", false, nil, []string{"foo"}, nil},
+				{"apex10000", "current", false, nil, []string{"foo"}, nil, NotForPrebuiltApex},
 			},
 			wantAliases: [][2]string{
 				{"foo", "apex10000"},
@@ -41,11 +45,11 @@
 		{
 			name: "merge",
 			in: []ApexInfo{
-				{"foo", "current", false, SdkRefs{{"baz", "1"}}, []string{"foo"}, nil},
-				{"bar", "current", false, SdkRefs{{"baz", "1"}}, []string{"bar"}, nil},
+				{"foo", "current", false, SdkRefs{{"baz", "1"}}, []string{"foo"}, nil, NotForPrebuiltApex},
+				{"bar", "current", false, SdkRefs{{"baz", "1"}}, []string{"bar"}, nil, NotForPrebuiltApex},
 			},
 			wantMerged: []ApexInfo{
-				{"apex10000_baz_1", "current", false, SdkRefs{{"baz", "1"}}, []string{"bar", "foo"}, nil}},
+				{"apex10000_baz_1", "current", false, SdkRefs{{"baz", "1"}}, []string{"bar", "foo"}, nil, false}},
 			wantAliases: [][2]string{
 				{"bar", "apex10000_baz_1"},
 				{"foo", "apex10000_baz_1"},
@@ -54,12 +58,12 @@
 		{
 			name: "don't merge version",
 			in: []ApexInfo{
-				{"foo", "current", false, nil, []string{"foo"}, nil},
-				{"bar", "30", false, nil, []string{"bar"}, nil},
+				{"foo", "current", false, nil, []string{"foo"}, nil, NotForPrebuiltApex},
+				{"bar", "30", false, nil, []string{"bar"}, nil, NotForPrebuiltApex},
 			},
 			wantMerged: []ApexInfo{
-				{"apex30", "30", false, nil, []string{"bar"}, nil},
-				{"apex10000", "current", false, nil, []string{"foo"}, nil},
+				{"apex30", "30", false, nil, []string{"bar"}, nil, NotForPrebuiltApex},
+				{"apex10000", "current", false, nil, []string{"foo"}, nil, NotForPrebuiltApex},
 			},
 			wantAliases: [][2]string{
 				{"bar", "apex30"},
@@ -69,11 +73,11 @@
 		{
 			name: "merge updatable",
 			in: []ApexInfo{
-				{"foo", "current", false, nil, []string{"foo"}, nil},
-				{"bar", "current", true, nil, []string{"bar"}, nil},
+				{"foo", "current", false, nil, []string{"foo"}, nil, NotForPrebuiltApex},
+				{"bar", "current", true, nil, []string{"bar"}, nil, NotForPrebuiltApex},
 			},
 			wantMerged: []ApexInfo{
-				{"apex10000", "current", true, nil, []string{"bar", "foo"}, nil},
+				{"apex10000", "current", true, nil, []string{"bar", "foo"}, nil, NotForPrebuiltApex},
 			},
 			wantAliases: [][2]string{
 				{"bar", "apex10000"},
@@ -83,19 +87,38 @@
 		{
 			name: "don't merge sdks",
 			in: []ApexInfo{
-				{"foo", "current", false, SdkRefs{{"baz", "1"}}, []string{"foo"}, nil},
-				{"bar", "current", false, SdkRefs{{"baz", "2"}}, []string{"bar"}, nil},
+				{"foo", "current", false, SdkRefs{{"baz", "1"}}, []string{"foo"}, nil, NotForPrebuiltApex},
+				{"bar", "current", false, SdkRefs{{"baz", "2"}}, []string{"bar"}, nil, NotForPrebuiltApex},
 			},
 			wantMerged: []ApexInfo{
-				{"apex10000_baz_2", "current", false, SdkRefs{{"baz", "2"}}, []string{"bar"}, nil},
-				{"apex10000_baz_1", "current", false, SdkRefs{{"baz", "1"}}, []string{"foo"}, nil},
+				{"apex10000_baz_2", "current", false, SdkRefs{{"baz", "2"}}, []string{"bar"}, nil, NotForPrebuiltApex},
+				{"apex10000_baz_1", "current", false, SdkRefs{{"baz", "1"}}, []string{"foo"}, nil, NotForPrebuiltApex},
 			},
 			wantAliases: [][2]string{
 				{"bar", "apex10000_baz_2"},
 				{"foo", "apex10000_baz_1"},
 			},
 		},
+		{
+			name: "don't merge when for prebuilt_apex",
+			in: []ApexInfo{
+				{"foo", "current", false, nil, []string{"foo"}, nil, NotForPrebuiltApex},
+				{"bar", "current", true, nil, []string{"bar"}, nil, NotForPrebuiltApex},
+				// This one should not be merged in with the others because it is for
+				// a prebuilt_apex.
+				{"baz", "current", true, nil, []string{"baz"}, nil, ForPrebuiltApex},
+			},
+			wantMerged: []ApexInfo{
+				{"apex10000", "current", true, nil, []string{"bar", "foo"}, nil, NotForPrebuiltApex},
+				{"baz", "current", true, nil, []string{"baz"}, nil, ForPrebuiltApex},
+			},
+			wantAliases: [][2]string{
+				{"bar", "apex10000"},
+				{"foo", "apex10000"},
+			},
+		},
 	}
+
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			config := TestConfig(buildDir, nil, "", nil)
diff --git a/android/bazel_handler.go b/android/bazel_handler.go
index a00a54d..2ee9c42 100644
--- a/android/bazel_handler.go
+++ b/android/bazel_handler.go
@@ -441,7 +441,10 @@
 		return err
 	}
 
-	context.buildStatements = bazel.AqueryBuildStatements([]byte(aqueryOutput))
+	context.buildStatements, err = bazel.AqueryBuildStatements([]byte(aqueryOutput))
+	if err != nil {
+		return err
+	}
 
 	// Issue a build command of the phony root to generate symlink forests for dependencies of the
 	// Bazel build. This is necessary because aquery invocations do not generate this symlink forest,
diff --git a/android/deapexer.go b/android/deapexer.go
new file mode 100644
index 0000000..63508d7
--- /dev/null
+++ b/android/deapexer.go
@@ -0,0 +1,83 @@
+// Copyright (C) 2021 The Android Open Source Project
+//
+// 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"
+	"strings"
+
+	"github.com/google/blueprint"
+)
+
+// Provides support for interacting with the `deapexer` module to which a `prebuilt_apex` module
+// will delegate the work to export files from a prebuilt '.apex` file.
+
+// The information exported by the `deapexer` module, access it using `DeapxerInfoProvider`.
+type DeapexerInfo struct {
+	// map from the name of an exported file from a prebuilt_apex to the path to that file. The
+	// exported file name is of the form <module>{<tag>} where <tag> is currently only allowed to be
+	// ".dexjar".
+	//
+	// See Prebuilt.ApexInfoMutator for more information.
+	exports map[string]Path
+}
+
+// The set of supported prebuilt export tags. Used to verify the tag parameter for
+// `PrebuiltExportPath`.
+var supportedPrebuiltExportTags = map[string]struct{}{
+	".dexjar": {},
+}
+
+// PrebuiltExportPath provides the path, or nil if not available, of a file exported from the
+// prebuilt_apex that created this ApexInfo.
+//
+// The exported file is identified by the module name and the tag:
+// * The module name is the name of the module that contributed the file when the .apex file
+//   referenced by the prebuilt_apex was built. It must be specified in one of the exported_...
+//   properties on the prebuilt_apex module.
+// * The tag identifies the type of file and is dependent on the module type.
+//
+// See apex/deapexer.go for more information.
+func (i DeapexerInfo) PrebuiltExportPath(name, tag string) Path {
+
+	if _, ok := supportedPrebuiltExportTags[tag]; !ok {
+		panic(fmt.Errorf("unsupported prebuilt export tag %q, expected one of %s",
+			tag, strings.Join(SortedStringKeys(supportedPrebuiltExportTags), ", ")))
+	}
+
+	path := i.exports[name+"{"+tag+"}"]
+	return path
+}
+
+// Provider that can be used from within the `GenerateAndroidBuildActions` of a module that depends
+// on a `deapexer` module to retrieve its `DeapexerInfo`.
+var DeapexerProvider = blueprint.NewProvider(DeapexerInfo{})
+
+// NewDeapexerInfo creates and initializes a DeapexerInfo that is suitable
+// for use with a prebuilt_apex module.
+//
+// See apex/deapexer.go for more information.
+func NewDeapexerInfo(exports map[string]Path) DeapexerInfo {
+	return DeapexerInfo{
+		exports: exports,
+	}
+}
+
+type deapexerTagStruct struct {
+	blueprint.BaseDependencyTag
+}
+
+// A tag that is used for dependencies on the `deapexer` module.
+var DeapexerTag = deapexerTagStruct{}
diff --git a/android/register.go b/android/register.go
index ca658f5..f84acad 100644
--- a/android/register.go
+++ b/android/register.go
@@ -37,9 +37,6 @@
 var singletons []singleton
 var preSingletons []singleton
 
-var bazelConverterSingletons []singleton
-var bazelConverterPreSingletons []singleton
-
 type mutator struct {
 	name            string
 	bottomUpMutator blueprint.BottomUpMutator
@@ -94,14 +91,6 @@
 	preSingletons = append(preSingletons, singleton{name, factory})
 }
 
-func RegisterBazelConverterSingletonType(name string, factory SingletonFactory) {
-	bazelConverterSingletons = append(bazelConverterSingletons, singleton{name, factory})
-}
-
-func RegisterBazelConverterPreSingletonType(name string, factory SingletonFactory) {
-	bazelConverterPreSingletons = append(bazelConverterPreSingletons, singleton{name, factory})
-}
-
 type Context struct {
 	*blueprint.Context
 	config Config
@@ -117,21 +106,20 @@
 // singletons, module types and mutators to register for converting Blueprint
 // files to semantically equivalent BUILD files.
 func (ctx *Context) RegisterForBazelConversion() {
-	for _, t := range bazelConverterPreSingletons {
-		ctx.RegisterPreSingletonType(t.name, SingletonFactoryAdaptor(ctx, t.factory))
-	}
-
 	for _, t := range moduleTypes {
 		ctx.RegisterModuleType(t.name, ModuleFactoryAdaptor(t.factory))
 	}
 
-	for _, t := range bazelConverterSingletons {
+	// Required for SingletonModule types, even though we are not using them.
+	for _, t := range singletons {
 		ctx.RegisterSingletonType(t.name, SingletonFactoryAdaptor(ctx, t.factory))
 	}
 
 	registerMutatorsForBazelConversion(ctx.Context)
 }
 
+// Register the pipeline of singletons, module types, and mutators for
+// generating build.ninja and other files for Kati, from Android.bp files.
 func (ctx *Context) Register() {
 	for _, t := range preSingletons {
 		ctx.RegisterPreSingletonType(t.name, SingletonFactoryAdaptor(ctx, t.factory))
diff --git a/android/testing.go b/android/testing.go
index 92ce014..470cfd6 100644
--- a/android/testing.go
+++ b/android/testing.go
@@ -469,6 +469,9 @@
 //
 // The build and source paths should be distinguishable based on their contents.
 func NormalizePathForTesting(path Path) string {
+	if path == nil {
+		return "<nil path>"
+	}
 	p := path.String()
 	// Allow absolute paths to /dev/
 	if strings.HasPrefix(p, "/dev/") {
diff --git a/apex/Android.bp b/apex/Android.bp
index e3a547c..77dde72 100644
--- a/apex/Android.bp
+++ b/apex/Android.bp
@@ -18,6 +18,7 @@
         "apex.go",
         "apex_singleton.go",
         "builder.go",
+        "deapexer.go",
         "key.go",
         "prebuilt.go",
         "vndk.go",
diff --git a/apex/allowed_deps.txt b/apex/allowed_deps.txt
index 786496f..81691f1 100644
--- a/apex/allowed_deps.txt
+++ b/apex/allowed_deps.txt
@@ -569,6 +569,7 @@
 prebuilt_libclang_rt.builtins-arm-android(minSdkVersion:(no version))
 prebuilt_libclang_rt.builtins-i686-android(minSdkVersion:(no version))
 prebuilt_libclang_rt.builtins-x86_64-android(minSdkVersion:(no version))
+prebuilt_libunwind(minSdkVersion:(no version))
 prebuilt_test_framework-sdkextensions(minSdkVersion:(no version))
 server_configurable_flags(minSdkVersion:29)
 service-permission(minSdkVersion:current)
diff --git a/apex/apex.go b/apex/apex.go
index 5cd18ed..4a9a9a3 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -1501,7 +1501,7 @@
 	return newApexFile(ctx, buildFile, buildFile.Base(), dirInApex, etc, fs)
 }
 
-// WalyPayloadDeps visits dependencies that contributes to the payload of this APEX. For each of the
+// WalkPayloadDeps visits dependencies that contributes to the payload of this APEX. For each of the
 // visited module, the `do` callback is executed. Returning true in the callback continues the visit
 // to the child modules. Returning false makes the visit to continue in the sibling or the parent
 // modules. This is used in check* functions below.
@@ -2854,7 +2854,7 @@
 		"libprofile-clang-extras_ndk",
 		"libprofile-extras",
 		"libprofile-extras_ndk",
-		"libunwind_llvm",
+		"libunwind",
 	}
 	return m
 }
diff --git a/apex/apex_test.go b/apex/apex_test.go
index fc74672..42b2404 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -190,6 +190,7 @@
 		"testdata/baz":                               nil,
 		"AppSet.apks":                                nil,
 		"foo.rs":                                     nil,
+		"libfoo.jar":                                 nil,
 	}
 
 	cc.GatherRequiredFilesForTest(fs)
@@ -1751,10 +1752,10 @@
 
 	// ensure apex variant of c++ is linked with static unwinder
 	cm := ctx.ModuleForTests("libc++", "android_arm64_armv8-a_shared_apex29").Module().(*cc.Module)
-	ensureListContains(t, cm.Properties.AndroidMkStaticLibs, "libgcc_stripped")
+	ensureListContains(t, cm.Properties.AndroidMkStaticLibs, "libunwind")
 	// note that platform variant is not.
 	cm = ctx.ModuleForTests("libc++", "android_arm64_armv8-a_shared").Module().(*cc.Module)
-	ensureListNotContains(t, cm.Properties.AndroidMkStaticLibs, "libgcc_stripped")
+	ensureListNotContains(t, cm.Properties.AndroidMkStaticLibs, "libunwind")
 }
 
 func TestApexMinSdkVersion_ErrorIfIncompatibleStubs(t *testing.T) {
@@ -4219,6 +4220,121 @@
 	}
 }
 
+func TestPrebuiltExportDexImplementationJars(t *testing.T) {
+	transform := func(config *dexpreopt.GlobalConfig) {
+		config.BootJars = android.CreateTestConfiguredJarList([]string{"myapex:libfoo"})
+	}
+
+	checkDexJarBuildPath := func(ctx *android.TestContext, name string) {
+		// Make sure the import has been given the correct path to the dex jar.
+		p := ctx.ModuleForTests(name, "android_common_myapex").Module().(java.Dependency)
+		dexJarBuildPath := p.DexJarBuildPath()
+		if expected, actual := ".intermediates/myapex.deapexer/android_common/deapexer/javalib/libfoo.jar", android.NormalizePathForTesting(dexJarBuildPath); actual != expected {
+			t.Errorf("Incorrect DexJarBuildPath value '%s', expected '%s'", actual, expected)
+		}
+	}
+
+	ensureNoSourceVariant := func(ctx *android.TestContext) {
+		// Make sure that an apex variant is not created for the source module.
+		if expected, actual := []string{"android_common"}, ctx.ModuleVariantsForTests("libfoo"); !reflect.DeepEqual(expected, actual) {
+			t.Errorf("invalid set of variants for %q: expected %q, found %q", "libfoo", expected, actual)
+		}
+	}
+
+	t.Run("prebuilt only", func(t *testing.T) {
+		bp := `
+		prebuilt_apex {
+			name: "myapex",
+			arch: {
+				arm64: {
+					src: "myapex-arm64.apex",
+				},
+				arm: {
+					src: "myapex-arm.apex",
+				},
+			},
+			exported_java_libs: ["libfoo"],
+		}
+
+		java_import {
+			name: "libfoo",
+			jars: ["libfoo.jar"],
+		}
+	`
+
+		// Make sure that dexpreopt can access dex implementation files from the prebuilt.
+		ctx := testDexpreoptWithApexes(t, bp, "", transform)
+
+		checkDexJarBuildPath(ctx, "libfoo")
+	})
+
+	t.Run("prebuilt with source preferred", func(t *testing.T) {
+
+		bp := `
+		prebuilt_apex {
+			name: "myapex",
+			arch: {
+				arm64: {
+					src: "myapex-arm64.apex",
+				},
+				arm: {
+					src: "myapex-arm.apex",
+				},
+			},
+			exported_java_libs: ["libfoo"],
+		}
+
+		java_import {
+			name: "libfoo",
+			jars: ["libfoo.jar"],
+		}
+
+		java_library {
+			name: "libfoo",
+		}
+	`
+
+		// Make sure that dexpreopt can access dex implementation files from the prebuilt.
+		ctx := testDexpreoptWithApexes(t, bp, "", transform)
+
+		checkDexJarBuildPath(ctx, "prebuilt_libfoo")
+		ensureNoSourceVariant(ctx)
+	})
+
+	t.Run("prebuilt preferred with source", func(t *testing.T) {
+		bp := `
+		prebuilt_apex {
+			name: "myapex",
+			prefer: true,
+			arch: {
+				arm64: {
+					src: "myapex-arm64.apex",
+				},
+				arm: {
+					src: "myapex-arm.apex",
+				},
+			},
+			exported_java_libs: ["libfoo"],
+		}
+
+		java_import {
+			name: "libfoo",
+			jars: ["libfoo.jar"],
+		}
+
+		java_library {
+			name: "libfoo",
+		}
+	`
+
+		// Make sure that dexpreopt can access dex implementation files from the prebuilt.
+		ctx := testDexpreoptWithApexes(t, bp, "", transform)
+
+		checkDexJarBuildPath(ctx, "prebuilt_libfoo")
+		ensureNoSourceVariant(ctx)
+	})
+}
+
 func TestApexWithTests(t *testing.T) {
 	ctx, config := testApex(t, `
 		apex_test {
@@ -5783,7 +5899,7 @@
 	testDexpreoptWithApexes(t, bp, errmsg, transformDexpreoptConfig)
 }
 
-func testDexpreoptWithApexes(t *testing.T, bp, errmsg string, transformDexpreoptConfig func(*dexpreopt.GlobalConfig)) {
+func testDexpreoptWithApexes(t *testing.T, bp, errmsg string, transformDexpreoptConfig func(*dexpreopt.GlobalConfig)) *android.TestContext {
 	t.Helper()
 
 	bp += cc.GatherRequiredDepsForTest(android.Android)
@@ -5808,6 +5924,7 @@
 	ctx := android.NewTestArchContext(config)
 	ctx.RegisterModuleType("apex", BundleFactory)
 	ctx.RegisterModuleType("apex_key", ApexKeyFactory)
+	ctx.RegisterModuleType("prebuilt_apex", PrebuiltFactory)
 	ctx.RegisterModuleType("filegroup", android.FileGroupFactory)
 	ctx.PreArchMutators(android.RegisterDefaultsPreArchMutators)
 	android.RegisterPrebuiltMutators(ctx)
@@ -5837,10 +5954,11 @@
 		android.FailIfErrored(t, errs)
 	} else if len(errs) > 0 {
 		android.FailIfNoMatchingErrors(t, errmsg, errs)
-		return
 	} else {
 		t.Fatalf("missing expected error %q (0 errors are returned)", errmsg)
 	}
+
+	return ctx
 }
 
 func TestUpdatable_should_set_min_sdk_version(t *testing.T) {
@@ -5939,6 +6057,56 @@
 		}
 		testNoUpdatableJarsInBootImage(t, "", transform)
 	})
+
+}
+
+func TestDexpreoptAccessDexFilesFromPrebuiltApex(t *testing.T) {
+	transform := func(config *dexpreopt.GlobalConfig) {
+		config.BootJars = android.CreateTestConfiguredJarList([]string{"myapex:libfoo"})
+	}
+	t.Run("prebuilt no source", func(t *testing.T) {
+		testDexpreoptWithApexes(t, `
+			prebuilt_apex {
+				name: "myapex" ,
+				arch: {
+					arm64: {
+						src: "myapex-arm64.apex",
+					},
+					arm: {
+						src: "myapex-arm.apex",
+					},
+				},
+			exported_java_libs: ["libfoo"],
+		}
+
+		java_import {
+			name: "libfoo",
+			jars: ["libfoo.jar"],
+		}
+`, "", transform)
+	})
+
+	t.Run("prebuilt no source", func(t *testing.T) {
+		testDexpreoptWithApexes(t, `
+			prebuilt_apex {
+				name: "myapex" ,
+				arch: {
+					arm64: {
+						src: "myapex-arm64.apex",
+					},
+					arm: {
+						src: "myapex-arm.apex",
+					},
+				},
+			exported_java_libs: ["libfoo"],
+		}
+
+		java_import {
+			name: "libfoo",
+			jars: ["libfoo.jar"],
+		}
+`, "", transform)
+	})
 }
 
 func testApexPermittedPackagesRules(t *testing.T, errmsg, bp string, apexBootJars []string, rules []android.Rule) {
diff --git a/apex/deapexer.go b/apex/deapexer.go
new file mode 100644
index 0000000..651cadf
--- /dev/null
+++ b/apex/deapexer.go
@@ -0,0 +1,139 @@
+// Copyright (C) 2021 The Android Open Source Project
+//
+// 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 apex
+
+import (
+	"android/soong/android"
+)
+
+// Contains 'deapexer' a private module type used by 'prebuilt_apex' to make dex files contained
+// within a .apex file referenced by `prebuilt_apex` available for use by their associated
+// `java_import` modules.
+//
+// An 'apex' module references `java_library` modules from which .dex files are obtained that are
+// stored in the resulting `.apex` file. The resulting `.apex` file is then made available as a
+// prebuilt by referencing it from a `prebuilt_apex`. For each such `java_library` that is used by
+// modules outside the `.apex` file a `java_import` prebuilt is made available referencing a jar
+// that contains the Java classes.
+//
+// When building a Java module type, e.g. `java_module` or `android_app` against such prebuilts the
+// `java_import` provides the classes jar  (jar containing `.class` files) against which the
+// module's `.java` files are compiled. That classes jar usually contains only stub classes. The
+// resulting classes jar is converted into a dex jar (jar containing `.dex` files). Then if
+// necessary the dex jar is further processed by `dexpreopt` to produce an optimized form of the
+// library specific to the current Android version. This process requires access to implementation
+// dex jars for each `java_import`. The `java_import` will obtain the implementation dex jar from
+// the `.apex` file in the associated `prebuilt_apex`.
+//
+// This is intentionally not registered by name as it is not intended to be used from within an
+// `Android.bp` file.
+
+// Properties that are specific to `deapexer` but which need to be provided on the `prebuilt_apex`
+// module.`
+type DeapexerProperties struct {
+	// List of java libraries that are embedded inside this prebuilt APEX bundle and for which this
+	// APEX bundle will provide dex implementation jars for use by dexpreopt and boot jars package
+	// check.
+	Exported_java_libs []string
+}
+
+type Deapexer struct {
+	android.ModuleBase
+	prebuilt android.Prebuilt
+
+	properties         DeapexerProperties
+	apexFileProperties ApexFileProperties
+
+	inputApex android.Path
+}
+
+func privateDeapexerFactory() android.Module {
+	module := &Deapexer{}
+	module.AddProperties(
+		&module.properties,
+		&module.apexFileProperties,
+	)
+	android.InitSingleSourcePrebuiltModule(module, &module.apexFileProperties, "Source")
+	android.InitAndroidMultiTargetsArchModule(module, android.DeviceSupported, android.MultilibCommon)
+	return module
+}
+
+func (p *Deapexer) Prebuilt() *android.Prebuilt {
+	return &p.prebuilt
+}
+
+func (p *Deapexer) Name() string {
+	return p.prebuilt.Name(p.ModuleBase.Name())
+}
+
+func (p *Deapexer) DepsMutator(ctx android.BottomUpMutatorContext) {
+	if err := p.apexFileProperties.selectSource(ctx); err != nil {
+		ctx.ModuleErrorf("%s", err)
+		return
+	}
+
+	// Add dependencies from the java modules to which this exports files from the `.apex` file onto
+	// this module so that they can access the `DeapexerInfo` object that this provides.
+	for _, lib := range p.properties.Exported_java_libs {
+		dep := prebuiltApexExportedModuleName(ctx, lib)
+		ctx.AddReverseDependency(ctx.Module(), android.DeapexerTag, dep)
+	}
+}
+
+func (p *Deapexer) GenerateAndroidBuildActions(ctx android.ModuleContext) {
+	p.inputApex = p.Prebuilt().SingleSourcePath(ctx)
+
+	// Create and remember the directory into which the .apex file's contents will be unpacked.
+	deapexerOutput := android.PathForModuleOut(ctx, "deapexer")
+
+	exports := make(map[string]android.Path)
+
+	// Create mappings from name+tag to all the required exported paths.
+	for _, l := range p.properties.Exported_java_libs {
+		// Populate the exports that this makes available. The path here must match the path of the
+		// file in the APEX created by apexFileForJavaModule(...).
+		exports[l+"{.dexjar}"] = deapexerOutput.Join(ctx, "javalib", l+".jar")
+	}
+
+	// If the prebuilt_apex exports any files then create a build rule that unpacks the apex using
+	// deapexer and verifies that all the required files were created. Also, make the mapping from
+	// name+tag to path available for other modules.
+	if len(exports) > 0 {
+		// Make the information available for other modules.
+		ctx.SetProvider(android.DeapexerProvider, android.NewDeapexerInfo(exports))
+
+		// Create a sorted list of the files that this exports.
+		exportedPaths := make(android.Paths, 0, len(exports))
+		for _, p := range exports {
+			exportedPaths = append(exportedPaths, p)
+		}
+		exportedPaths = android.SortedUniquePaths(exportedPaths)
+
+		// The apex needs to export some files so create a ninja rule to unpack the apex and check that
+		// the required files are present.
+		builder := android.NewRuleBuilder(pctx, ctx)
+		command := builder.Command()
+		command.
+			Tool(android.PathForSource(ctx, "build/soong/scripts/unpack-prebuilt-apex.sh")).
+			BuiltTool("deapexer").
+			BuiltTool("debugfs").
+			Input(p.inputApex).
+			Text(deapexerOutput.String())
+		for _, p := range exportedPaths {
+			command.Output(p.(android.WritablePath))
+		}
+		builder.Build("deapexer", "deapex "+ctx.ModuleName())
+	}
+}
diff --git a/apex/prebuilt.go b/apex/prebuilt.go
index 50e892e..c72a9eb 100644
--- a/apex/prebuilt.go
+++ b/apex/prebuilt.go
@@ -158,6 +158,7 @@
 
 type PrebuiltProperties struct {
 	ApexFileProperties
+	DeapexerProperties
 
 	Installable *bool
 	// Optional name for the installed apex. If unspecified, name of the
@@ -198,19 +199,152 @@
 }
 
 // prebuilt_apex imports an `.apex` file into the build graph as if it was built with apex.
+//
+// If this needs to make files from within a `.apex` file available for use by other Soong modules,
+// e.g. make dex implementation jars available for java_import modules isted in exported_java_libs,
+// it does so as follows:
+//
+// 1. It creates a `deapexer` module that actually extracts the files from the `.apex` file and
+//    makes them available for use by other modules, at both Soong and ninja levels.
+//
+// 2. It adds a dependency onto those modules and creates an apex specific variant similar to what
+//    an `apex` module does. That ensures that code which looks for specific apex variant, e.g.
+//    dexpreopt, will work the same way from source and prebuilt.
+//
+// 3. The `deapexer` module adds a dependency from the modules that require the exported files onto
+//    itself so that they can retrieve the file paths to those files.
+//
 func PrebuiltFactory() android.Module {
 	module := &Prebuilt{}
 	module.AddProperties(&module.properties)
 	android.InitSingleSourcePrebuiltModule(module, &module.properties, "Source")
 	android.InitAndroidMultiTargetsArchModule(module, android.DeviceSupported, android.MultilibCommon)
+
+	android.AddLoadHook(module, func(ctx android.LoadHookContext) {
+		props := struct {
+			Name *string
+		}{
+			Name: proptools.StringPtr(module.BaseModuleName() + ".deapexer"),
+		}
+		ctx.CreateModule(privateDeapexerFactory,
+			&props,
+			&module.properties.ApexFileProperties,
+			&module.properties.DeapexerProperties,
+		)
+	})
+
 	return module
 }
 
+func prebuiltApexExportedModuleName(ctx android.BottomUpMutatorContext, name string) string {
+	// The prebuilt_apex should be depending on prebuilt modules but as this runs after
+	// prebuilt_rename the prebuilt module may or may not be using the prebuilt_ prefixed named. So,
+	// check to see if the prefixed name is in use first, if it is then use that, otherwise assume
+	// the unprefixed name is the one to use. If the unprefixed one turns out to be a source module
+	// and not a renamed prebuilt module then that will be detected and reported as an error when
+	// processing the dependency in ApexInfoMutator().
+	prebuiltName := "prebuilt_" + name
+	if ctx.OtherModuleExists(prebuiltName) {
+		name = prebuiltName
+	}
+	return name
+}
+
 func (p *Prebuilt) DepsMutator(ctx android.BottomUpMutatorContext) {
 	if err := p.properties.selectSource(ctx); err != nil {
 		ctx.ModuleErrorf("%s", err)
 		return
 	}
+
+	// Add dependencies onto the java modules that represent the java libraries that are provided by
+	// and exported from this prebuilt apex.
+	for _, lib := range p.properties.Exported_java_libs {
+		dep := prebuiltApexExportedModuleName(ctx, lib)
+		ctx.AddFarVariationDependencies(ctx.Config().AndroidCommonTarget.Variations(), javaLibTag, dep)
+	}
+}
+
+var _ ApexInfoMutator = (*Prebuilt)(nil)
+
+// ApexInfoMutator marks any modules for which this apex exports a file as requiring an apex
+// specific variant and checks that they are supported.
+//
+// The apexMutator will ensure that the ApexInfo objects passed to BuildForApex(ApexInfo) are
+// associated with the apex specific variant using the ApexInfoProvider for later retrieval.
+//
+// Unlike the source apex module type the prebuilt_apex module type cannot share compatible variants
+// across prebuilt_apex modules. That is because there is no way to determine whether two
+// prebuilt_apex modules that export files for the same module are compatible. e.g. they could have
+// been built from different source at different times or they could have been built with different
+// build options that affect the libraries.
+//
+// While it may be possible to provide sufficient information to determine whether two prebuilt_apex
+// modules were compatible it would be a lot of work and would not provide much benefit for a couple
+// of reasons:
+// * The number of prebuilt_apex modules that will be exporting files for the same module will be
+//   low as the prebuilt_apex only exports files for the direct dependencies that require it and
+//   very few modules are direct dependencies of multiple prebuilt_apex modules, e.g. there are a
+//   few com.android.art* apex files that contain the same contents and could export files for the
+//   same modules but only one of them needs to do so. Contrast that with source apex modules which
+//   need apex specific variants for every module that contributes code to the apex, whether direct
+//   or indirect.
+// * The build cost of a prebuilt_apex variant is generally low as at worst it will involve some
+//   extra copying of files. Contrast that with source apex modules that has to build each variant
+//   from source.
+func (p *Prebuilt) ApexInfoMutator(mctx android.TopDownMutatorContext) {
+
+	// Collect direct dependencies into contents.
+	contents := make(map[string]android.ApexMembership)
+
+	// Collect the list of dependencies.
+	var dependencies []android.ApexModule
+	mctx.VisitDirectDeps(func(m android.Module) {
+		tag := mctx.OtherModuleDependencyTag(m)
+		if tag == javaLibTag {
+			depName := mctx.OtherModuleName(m)
+
+			// It is an error if the other module is not a prebuilt.
+			if _, ok := m.(android.PrebuiltInterface); !ok {
+				mctx.PropertyErrorf("exported_java_libs", "%q is not a prebuilt module", depName)
+				return
+			}
+
+			// It is an error if the other module is not an ApexModule.
+			if _, ok := m.(android.ApexModule); !ok {
+				mctx.PropertyErrorf("exported_java_libs", "%q is not usable within an apex", depName)
+				return
+			}
+
+			// Strip off the prebuilt_ prefix if present before storing content to ensure consistent
+			// behavior whether there is a corresponding source module present or not.
+			depName = android.RemoveOptionalPrebuiltPrefix(depName)
+
+			// Remember that this module was added as a direct dependency.
+			contents[depName] = contents[depName].Add(true)
+
+			// Add the module to the list of dependencies that need to have an APEX variant.
+			dependencies = append(dependencies, m.(android.ApexModule))
+		}
+	})
+
+	// Create contents for the prebuilt_apex and store it away for later use.
+	apexContents := android.NewApexContents(contents)
+	mctx.SetProvider(ApexBundleInfoProvider, ApexBundleInfo{
+		Contents: apexContents,
+	})
+
+	// Create an ApexInfo for the prebuilt_apex.
+	apexInfo := android.ApexInfo{
+		ApexVariationName: mctx.ModuleName(),
+		InApexes:          []string{mctx.ModuleName()},
+		ApexContents:      []*android.ApexContents{apexContents},
+		ForPrebuiltApex:   true,
+	}
+
+	// Mark the dependencies of this module as requiring a variant for this module.
+	for _, am := range dependencies {
+		am.BuildForApex(apexInfo)
+	}
 }
 
 func (p *Prebuilt) GenerateAndroidBuildActions(ctx android.ModuleContext) {
diff --git a/bazel/Android.bp b/bazel/Android.bp
index 05eddc1..d222d98 100644
--- a/bazel/Android.bp
+++ b/bazel/Android.bp
@@ -6,6 +6,9 @@
         "constants.go",
         "properties.go",
     ],
+    testSrcs: [
+        "aquery_test.go",
+    ],
     pluginFor: [
         "soong_build",
     ],
diff --git a/bazel/aquery.go b/bazel/aquery.go
index 404be8c..a196e8b 100644
--- a/bazel/aquery.go
+++ b/bazel/aquery.go
@@ -83,11 +83,15 @@
 // AqueryBuildStatements returns an array of BuildStatements which should be registered (and output
 // to a ninja file) to correspond one-to-one with the given action graph json proto (from a bazel
 // aquery invocation).
-func AqueryBuildStatements(aqueryJsonProto []byte) []BuildStatement {
+func AqueryBuildStatements(aqueryJsonProto []byte) ([]BuildStatement, error) {
 	buildStatements := []BuildStatement{}
 
 	var aqueryResult actionGraphContainer
-	json.Unmarshal(aqueryJsonProto, &aqueryResult)
+	err := json.Unmarshal(aqueryJsonProto, &aqueryResult)
+
+	if err != nil {
+		return nil, err
+	}
 
 	pathFragments := map[int]pathFragment{}
 	for _, pathFragment := range aqueryResult.PathFragments {
@@ -97,8 +101,7 @@
 	for _, artifact := range aqueryResult.Artifacts {
 		artifactPath, err := expandPathFragment(artifact.PathFragmentId, pathFragments)
 		if err != nil {
-			// TODO(cparsons): Better error handling.
-			panic(err.Error())
+			return nil, err
 		}
 		artifactIdToPath[artifact.Id] = artifactPath
 	}
@@ -110,15 +113,24 @@
 	for _, actionEntry := range aqueryResult.Actions {
 		outputPaths := []string{}
 		for _, outputId := range actionEntry.OutputIds {
-			// TODO(cparsons): Validate the id is present.
-			outputPaths = append(outputPaths, artifactIdToPath[outputId])
+			outputPath, exists := artifactIdToPath[outputId]
+			if !exists {
+				return nil, fmt.Errorf("undefined outputId %d", outputId)
+			}
+			outputPaths = append(outputPaths, outputPath)
 		}
 		inputPaths := []string{}
 		for _, inputDepSetId := range actionEntry.InputDepSetIds {
-			// TODO(cparsons): Validate the id is present.
-			for _, inputId := range depsetIdToArtifactIds[inputDepSetId] {
-				// TODO(cparsons): Validate the id is present.
-				inputPaths = append(inputPaths, artifactIdToPath[inputId])
+			inputArtifacts, exists := depsetIdToArtifactIds[inputDepSetId]
+			if !exists {
+				return nil, fmt.Errorf("undefined input depsetId %d", inputDepSetId)
+			}
+			for _, inputId := range inputArtifacts {
+				inputPath, exists := artifactIdToPath[inputId]
+				if !exists {
+					return nil, fmt.Errorf("undefined input artifactId %d", inputId)
+				}
+				inputPaths = append(inputPaths, inputPath)
 			}
 		}
 		buildStatement := BuildStatement{
@@ -130,7 +142,7 @@
 		buildStatements = append(buildStatements, buildStatement)
 	}
 
-	return buildStatements
+	return buildStatements, nil
 }
 
 func expandPathFragment(id int, pathFragmentsMap map[int]pathFragment) (string, error) {
@@ -140,7 +152,7 @@
 	for currId > 0 {
 		currFragment, ok := pathFragmentsMap[currId]
 		if !ok {
-			return "", fmt.Errorf("undefined path fragment id '%s'", currId)
+			return "", fmt.Errorf("undefined path fragment id %d", currId)
 		}
 		labels = append([]string{currFragment.Label}, labels...)
 		currId = currFragment.ParentId
diff --git a/bazel/aquery_test.go b/bazel/aquery_test.go
new file mode 100644
index 0000000..1bd6e67
--- /dev/null
+++ b/bazel/aquery_test.go
@@ -0,0 +1,450 @@
+// Copyright 2020 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 bazel
+
+import (
+	"fmt"
+	"reflect"
+	"testing"
+)
+
+func TestAqueryMultiArchGenrule(t *testing.T) {
+	// This input string is retrieved from a real build of bionic-related genrules.
+	const inputString = `
+{
+  "artifacts": [{
+    "id": 1,
+    "pathFragmentId": 1
+  }, {
+    "id": 2,
+    "pathFragmentId": 6
+  }, {
+    "id": 3,
+    "pathFragmentId": 8
+  }, {
+    "id": 4,
+    "pathFragmentId": 12
+  }, {
+    "id": 5,
+    "pathFragmentId": 19
+  }, {
+    "id": 6,
+    "pathFragmentId": 20
+  }, {
+    "id": 7,
+    "pathFragmentId": 21
+  }],
+  "actions": [{
+    "targetId": 1,
+    "actionKey": "ab53f6ecbdc2ee8cb8812613b63205464f1f5083f6dca87081a0a398c0f1ecf7",
+    "mnemonic": "Genrule",
+    "configurationId": 1,
+    "arguments": ["/bin/bash", "-c", "source ../bazel_tools/tools/genrule/genrule-setup.sh; ../sourceroot/bionic/libc/tools/gensyscalls.py arm ../sourceroot/bionic/libc/SYSCALLS.TXT \u003e bazel-out/sourceroot/k8-fastbuild/bin/bionic/libc/syscalls-arm.S"],
+    "environmentVariables": [{
+      "key": "PATH",
+      "value": "/bin:/usr/bin:/usr/local/bin"
+    }],
+    "inputDepSetIds": [1],
+    "outputIds": [4],
+    "primaryOutputId": 4
+  }, {
+    "targetId": 2,
+    "actionKey": "9f4309ce165dac458498cb92811c18b0b7919782cc37b82a42d2141b8cc90826",
+    "mnemonic": "Genrule",
+    "configurationId": 1,
+    "arguments": ["/bin/bash", "-c", "source ../bazel_tools/tools/genrule/genrule-setup.sh; ../sourceroot/bionic/libc/tools/gensyscalls.py x86 ../sourceroot/bionic/libc/SYSCALLS.TXT \u003e bazel-out/sourceroot/k8-fastbuild/bin/bionic/libc/syscalls-x86.S"],
+    "environmentVariables": [{
+      "key": "PATH",
+      "value": "/bin:/usr/bin:/usr/local/bin"
+    }],
+    "inputDepSetIds": [2],
+    "outputIds": [5],
+    "primaryOutputId": 5
+  }, {
+    "targetId": 3,
+    "actionKey": "50d6c586103ebeed3a218195540bcc30d329464eae36377eb82f8ce7c36ac342",
+    "mnemonic": "Genrule",
+    "configurationId": 1,
+    "arguments": ["/bin/bash", "-c", "source ../bazel_tools/tools/genrule/genrule-setup.sh; ../sourceroot/bionic/libc/tools/gensyscalls.py x86_64 ../sourceroot/bionic/libc/SYSCALLS.TXT \u003e bazel-out/sourceroot/k8-fastbuild/bin/bionic/libc/syscalls-x86_64.S"],
+    "environmentVariables": [{
+      "key": "PATH",
+      "value": "/bin:/usr/bin:/usr/local/bin"
+    }],
+    "inputDepSetIds": [3],
+    "outputIds": [6],
+    "primaryOutputId": 6
+  }, {
+    "targetId": 4,
+    "actionKey": "f30cbe442f5216f4223cf16a39112cad4ec56f31f49290d85cff587e48647ffa",
+    "mnemonic": "Genrule",
+    "configurationId": 1,
+    "arguments": ["/bin/bash", "-c", "source ../bazel_tools/tools/genrule/genrule-setup.sh; ../sourceroot/bionic/libc/tools/gensyscalls.py arm64 ../sourceroot/bionic/libc/SYSCALLS.TXT \u003e bazel-out/sourceroot/k8-fastbuild/bin/bionic/libc/syscalls-arm64.S"],
+    "environmentVariables": [{
+      "key": "PATH",
+      "value": "/bin:/usr/bin:/usr/local/bin"
+    }],
+    "inputDepSetIds": [4],
+    "outputIds": [7],
+    "primaryOutputId": 7
+  }],
+  "targets": [{
+    "id": 1,
+    "label": "@sourceroot//bionic/libc:syscalls-arm",
+    "ruleClassId": 1
+  }, {
+    "id": 2,
+    "label": "@sourceroot//bionic/libc:syscalls-x86",
+    "ruleClassId": 1
+  }, {
+    "id": 3,
+    "label": "@sourceroot//bionic/libc:syscalls-x86_64",
+    "ruleClassId": 1
+  }, {
+    "id": 4,
+    "label": "@sourceroot//bionic/libc:syscalls-arm64",
+    "ruleClassId": 1
+  }],
+  "depSetOfFiles": [{
+    "id": 1,
+    "directArtifactIds": [1, 2, 3]
+  }, {
+    "id": 2,
+    "directArtifactIds": [1, 2, 3]
+  }, {
+    "id": 3,
+    "directArtifactIds": [1, 2, 3]
+  }, {
+    "id": 4,
+    "directArtifactIds": [1, 2, 3]
+  }],
+  "configuration": [{
+    "id": 1,
+    "mnemonic": "k8-fastbuild",
+    "platformName": "k8",
+    "checksum": "485c362832c178e367d972177f68e69e0981e51e67ef1c160944473db53fe046"
+  }],
+  "ruleClasses": [{
+    "id": 1,
+    "name": "genrule"
+  }],
+  "pathFragments": [{
+    "id": 5,
+    "label": ".."
+  }, {
+    "id": 4,
+    "label": "sourceroot",
+    "parentId": 5
+  }, {
+    "id": 3,
+    "label": "bionic",
+    "parentId": 4
+  }, {
+    "id": 2,
+    "label": "libc",
+    "parentId": 3
+  }, {
+    "id": 1,
+    "label": "SYSCALLS.TXT",
+    "parentId": 2
+  }, {
+    "id": 7,
+    "label": "tools",
+    "parentId": 2
+  }, {
+    "id": 6,
+    "label": "gensyscalls.py",
+    "parentId": 7
+  }, {
+    "id": 11,
+    "label": "bazel_tools",
+    "parentId": 5
+  }, {
+    "id": 10,
+    "label": "tools",
+    "parentId": 11
+  }, {
+    "id": 9,
+    "label": "genrule",
+    "parentId": 10
+  }, {
+    "id": 8,
+    "label": "genrule-setup.sh",
+    "parentId": 9
+  }, {
+    "id": 18,
+    "label": "bazel-out"
+  }, {
+    "id": 17,
+    "label": "sourceroot",
+    "parentId": 18
+  }, {
+    "id": 16,
+    "label": "k8-fastbuild",
+    "parentId": 17
+  }, {
+    "id": 15,
+    "label": "bin",
+    "parentId": 16
+  }, {
+    "id": 14,
+    "label": "bionic",
+    "parentId": 15
+  }, {
+    "id": 13,
+    "label": "libc",
+    "parentId": 14
+  }, {
+    "id": 12,
+    "label": "syscalls-arm.S",
+    "parentId": 13
+  }, {
+    "id": 19,
+    "label": "syscalls-x86.S",
+    "parentId": 13
+  }, {
+    "id": 20,
+    "label": "syscalls-x86_64.S",
+    "parentId": 13
+  }, {
+    "id": 21,
+    "label": "syscalls-arm64.S",
+    "parentId": 13
+  }]
+}`
+	actualbuildStatements, _ := AqueryBuildStatements([]byte(inputString))
+	expectedBuildStatements := []BuildStatement{}
+	for _, arch := range []string{"arm", "arm64", "x86", "x86_64"} {
+		expectedBuildStatements = append(expectedBuildStatements,
+			BuildStatement{
+				Command: fmt.Sprintf(
+					"/bin/bash -c 'source ../bazel_tools/tools/genrule/genrule-setup.sh; ../sourceroot/bionic/libc/tools/gensyscalls.py %s ../sourceroot/bionic/libc/SYSCALLS.TXT > bazel-out/sourceroot/k8-fastbuild/bin/bionic/libc/syscalls-%s.S'",
+					arch, arch),
+				OutputPaths: []string{
+					fmt.Sprintf("bazel-out/sourceroot/k8-fastbuild/bin/bionic/libc/syscalls-%s.S", arch),
+				},
+				InputPaths: []string{
+					"../sourceroot/bionic/libc/SYSCALLS.TXT",
+					"../sourceroot/bionic/libc/tools/gensyscalls.py",
+					"../bazel_tools/tools/genrule/genrule-setup.sh",
+				},
+				Env: []KeyValuePair{
+					KeyValuePair{Key: "PATH", Value: "/bin:/usr/bin:/usr/local/bin"},
+				},
+				Mnemonic: "Genrule",
+			})
+	}
+	assertBuildStatements(t, expectedBuildStatements, actualbuildStatements)
+}
+
+func TestInvalidOutputId(t *testing.T) {
+	const inputString = `
+{
+  "artifacts": [{
+    "id": 1,
+    "pathFragmentId": 1
+  }, {
+    "id": 2,
+    "pathFragmentId": 2
+  }],
+  "actions": [{
+    "targetId": 1,
+    "actionKey": "x",
+    "mnemonic": "x",
+    "arguments": ["touch", "foo"],
+    "inputDepSetIds": [1],
+    "outputIds": [3],
+    "primaryOutputId": 3
+  }],
+  "depSetOfFiles": [{
+    "id": 1,
+    "directArtifactIds": [1, 2]
+  }],
+  "pathFragments": [{
+    "id": 1,
+    "label": "one"
+  }, {
+    "id": 2,
+    "label": "two"
+  }]
+}`
+
+	_, err := AqueryBuildStatements([]byte(inputString))
+	assertError(t, err, "undefined outputId 3")
+}
+
+func TestInvalidInputDepsetId(t *testing.T) {
+	const inputString = `
+{
+  "artifacts": [{
+    "id": 1,
+    "pathFragmentId": 1
+  }, {
+    "id": 2,
+    "pathFragmentId": 2
+  }],
+  "actions": [{
+    "targetId": 1,
+    "actionKey": "x",
+    "mnemonic": "x",
+    "arguments": ["touch", "foo"],
+    "inputDepSetIds": [2],
+    "outputIds": [1],
+    "primaryOutputId": 1
+  }],
+  "depSetOfFiles": [{
+    "id": 1,
+    "directArtifactIds": [1, 2]
+  }],
+  "pathFragments": [{
+    "id": 1,
+    "label": "one"
+  }, {
+    "id": 2,
+    "label": "two"
+  }]
+}`
+
+	_, err := AqueryBuildStatements([]byte(inputString))
+	assertError(t, err, "undefined input depsetId 2")
+}
+
+func TestInvalidInputArtifactId(t *testing.T) {
+	const inputString = `
+{
+  "artifacts": [{
+    "id": 1,
+    "pathFragmentId": 1
+  }, {
+    "id": 2,
+    "pathFragmentId": 2
+  }],
+  "actions": [{
+    "targetId": 1,
+    "actionKey": "x",
+    "mnemonic": "x",
+    "arguments": ["touch", "foo"],
+    "inputDepSetIds": [1],
+    "outputIds": [1],
+    "primaryOutputId": 1
+  }],
+  "depSetOfFiles": [{
+    "id": 1,
+    "directArtifactIds": [1, 3]
+  }],
+  "pathFragments": [{
+    "id": 1,
+    "label": "one"
+  }, {
+    "id": 2,
+    "label": "two"
+  }]
+}`
+
+	_, err := AqueryBuildStatements([]byte(inputString))
+	assertError(t, err, "undefined input artifactId 3")
+}
+
+func TestInvalidPathFragmentId(t *testing.T) {
+	const inputString = `
+{
+  "artifacts": [{
+    "id": 1,
+    "pathFragmentId": 1
+  }, {
+    "id": 2,
+    "pathFragmentId": 2
+  }],
+  "actions": [{
+    "targetId": 1,
+    "actionKey": "x",
+    "mnemonic": "x",
+    "arguments": ["touch", "foo"],
+    "inputDepSetIds": [1],
+    "outputIds": [1],
+    "primaryOutputId": 1
+  }],
+  "depSetOfFiles": [{
+    "id": 1,
+    "directArtifactIds": [1, 2]
+  }],
+  "pathFragments": [{
+    "id": 1,
+    "label": "one"
+  }, {
+    "id": 2,
+    "label": "two",
+		"parentId": 3
+  }]
+}`
+
+	_, err := AqueryBuildStatements([]byte(inputString))
+	assertError(t, err, "undefined path fragment id 3")
+}
+
+func assertError(t *testing.T, err error, expected string) {
+	if err == nil || err.Error() != expected {
+		t.Errorf("expected error '%s', but got: %s", expected, err)
+	}
+}
+
+// Asserts that the given actual build statements match the given expected build statements.
+// Build statement equivalence is determined using buildStatementEquals.
+func assertBuildStatements(t *testing.T, expected []BuildStatement, actual []BuildStatement) {
+	if len(expected) != len(actual) {
+		t.Errorf("expected %d build statements, but got %d,\n expected: %s,\n actual: %s",
+			len(expected), len(actual), expected, actual)
+		return
+	}
+ACTUAL_LOOP:
+	for _, actualStatement := range actual {
+		for _, expectedStatement := range expected {
+			if buildStatementEquals(actualStatement, expectedStatement) {
+				continue ACTUAL_LOOP
+			}
+		}
+		t.Errorf("unexpected build statement %s.\n expected: %s",
+			actualStatement, expected)
+		return
+	}
+}
+
+func buildStatementEquals(first BuildStatement, second BuildStatement) bool {
+	if first.Mnemonic != second.Mnemonic {
+		return false
+	}
+	if first.Command != second.Command {
+		return false
+	}
+	// Ordering is significant for environment variables.
+	if !reflect.DeepEqual(first.Env, second.Env) {
+		return false
+	}
+	// Ordering is irrelevant for input and output paths, so compare sets.
+	if !reflect.DeepEqual(stringSet(first.InputPaths), stringSet(second.InputPaths)) {
+		return false
+	}
+	if !reflect.DeepEqual(stringSet(first.OutputPaths), stringSet(second.OutputPaths)) {
+		return false
+	}
+	return true
+}
+
+func stringSet(stringSlice []string) map[string]struct{} {
+	stringMap := make(map[string]struct{})
+	for _, s := range stringSlice {
+		stringMap[s] = struct{}{}
+	}
+	return stringMap
+}
diff --git a/bp2build/bp2build.go b/bp2build/bp2build.go
index 30f298a..49729e0 100644
--- a/bp2build/bp2build.go
+++ b/bp2build/bp2build.go
@@ -16,52 +16,34 @@
 
 import (
 	"android/soong/android"
+	"fmt"
 	"os"
 )
 
-// The Bazel bp2build singleton is responsible for writing .bzl files that are equivalent to
+// The Bazel bp2build code generator is responsible for writing .bzl files that are equivalent to
 // Android.bp files that are capable of being built with Bazel.
-func init() {
-	android.RegisterBazelConverterPreSingletonType("androidbp_to_build", AndroidBpToBuildSingleton)
-}
-
-func AndroidBpToBuildSingleton() android.Singleton {
-	return &androidBpToBuildSingleton{
-		name: "bp2build",
-	}
-}
-
-type androidBpToBuildSingleton struct {
-	name      string
-	outputDir android.OutputPath
-}
-
-func (s *androidBpToBuildSingleton) GenerateBuildActions(ctx android.SingletonContext) {
-	s.outputDir = android.PathForOutput(ctx, s.name)
-	android.RemoveAllOutputDir(s.outputDir)
-
-	if !ctx.Config().IsEnvTrue("CONVERT_TO_BAZEL") {
-		return
-	}
+func Codegen(ctx CodegenContext) {
+	outputDir := android.PathForOutput(ctx, "bp2build")
+	android.RemoveAllOutputDir(outputDir)
 
 	ruleShims := CreateRuleShims(android.ModuleTypeFactories())
 
-	buildToTargets := GenerateSoongModuleTargets(ctx)
+	buildToTargets := GenerateSoongModuleTargets(ctx.Context())
 
 	filesToWrite := CreateBazelFiles(ruleShims, buildToTargets)
 	for _, f := range filesToWrite {
-		if err := s.writeFile(ctx, f); err != nil {
-			ctx.Errorf("Failed to write %q (dir %q) due to %q", f.Basename, f.Dir, err)
+		if err := writeFile(outputDir, ctx, f); err != nil {
+			fmt.Errorf("Failed to write %q (dir %q) due to %q", f.Basename, f.Dir, err)
 		}
 	}
 }
 
-func (s *androidBpToBuildSingleton) getOutputPath(ctx android.PathContext, dir string) android.OutputPath {
-	return s.outputDir.Join(ctx, dir)
+func writeFile(outputDir android.OutputPath, ctx android.PathContext, f BazelFile) error {
+	return writeReadOnlyFile(ctx, getOutputPath(outputDir, ctx, f.Dir), f.Basename, f.Contents)
 }
 
-func (s *androidBpToBuildSingleton) writeFile(ctx android.PathContext, f BazelFile) error {
-	return writeReadOnlyFile(ctx, s.getOutputPath(ctx, f.Dir), f.Basename, f.Contents)
+func getOutputPath(outputDir android.OutputPath, ctx android.PathContext, dir string) android.OutputPath {
+	return outputDir.Join(ctx, dir)
 }
 
 // The auto-conversion directory should be read-only, sufficient for bazel query. The files
diff --git a/bp2build/build_conversion.go b/bp2build/build_conversion.go
index 0329685..bece8f6 100644
--- a/bp2build/build_conversion.go
+++ b/bp2build/build_conversion.go
@@ -39,8 +39,26 @@
 	ModuleSubDir(module blueprint.Module) string
 	ModuleType(module blueprint.Module) string
 
-	VisitAllModulesBlueprint(visit func(blueprint.Module))
-	VisitDirectDeps(module android.Module, visit func(android.Module))
+	VisitAllModules(visit func(blueprint.Module))
+	VisitDirectDeps(module blueprint.Module, visit func(blueprint.Module))
+}
+
+type CodegenContext struct {
+	config  android.Config
+	context android.Context
+}
+
+func (ctx CodegenContext) AddNinjaFileDeps(...string) {}
+func (ctx CodegenContext) Config() android.Config     { return ctx.config }
+func (ctx CodegenContext) Context() android.Context   { return ctx.context }
+
+// NewCodegenContext creates a wrapper context that conforms to PathContext for
+// writing BUILD files in the output directory.
+func NewCodegenContext(config android.Config, context android.Context) CodegenContext {
+	return CodegenContext{
+		context: context,
+		config:  config,
+	}
 }
 
 // props is an unsorted map. This function ensures that
@@ -57,7 +75,7 @@
 
 func GenerateSoongModuleTargets(ctx bpToBuildContext) map[string][]BazelTarget {
 	buildFileToTargets := make(map[string][]BazelTarget)
-	ctx.VisitAllModulesBlueprint(func(m blueprint.Module) {
+	ctx.VisitAllModules(func(m blueprint.Module) {
 		dir := ctx.ModuleDir(m)
 		t := generateSoongModuleTarget(ctx, m)
 		buildFileToTargets[ctx.ModuleDir(m)] = append(buildFileToTargets[dir], t)
@@ -75,7 +93,7 @@
 	// out the implications of that.
 	depLabels := map[string]bool{}
 	if aModule, ok := m.(android.Module); ok {
-		ctx.VisitDirectDeps(aModule, func(depModule android.Module) {
+		ctx.VisitDirectDeps(aModule, func(depModule blueprint.Module) {
 			depLabels[qualifiedTargetLabel(ctx, depModule)] = true
 		})
 	}
diff --git a/bp2build/build_conversion_test.go b/bp2build/build_conversion_test.go
index 8230ad8..4e31aa7 100644
--- a/bp2build/build_conversion_test.go
+++ b/bp2build/build_conversion_test.go
@@ -200,11 +200,7 @@
 		_, errs = ctx.PrepareBuildActions(config)
 		android.FailIfErrored(t, errs)
 
-		bp2BuildCtx := bp2buildBlueprintWrapContext{
-			bpCtx: ctx.Context.Context,
-		}
-
-		bazelTargets := GenerateSoongModuleTargets(&bp2BuildCtx)[dir]
+		bazelTargets := GenerateSoongModuleTargets(ctx.Context.Context)[dir]
 		if g, w := len(bazelTargets), 1; g != w {
 			t.Fatalf("Expected %d bazel target, got %d", w, g)
 		}
diff --git a/bp2build/testing.go b/bp2build/testing.go
index 160412d..2da32c6 100644
--- a/bp2build/testing.go
+++ b/bp2build/testing.go
@@ -2,8 +2,6 @@
 
 import (
 	"android/soong/android"
-
-	"github.com/google/blueprint"
 )
 
 type nestedProps struct {
@@ -102,35 +100,3 @@
 	android.InitDefaultsModule(m)
 	return m
 }
-
-type bp2buildBlueprintWrapContext struct {
-	bpCtx *blueprint.Context
-}
-
-func (ctx *bp2buildBlueprintWrapContext) ModuleName(module blueprint.Module) string {
-	return ctx.bpCtx.ModuleName(module)
-}
-
-func (ctx *bp2buildBlueprintWrapContext) ModuleDir(module blueprint.Module) string {
-	return ctx.bpCtx.ModuleDir(module)
-}
-
-func (ctx *bp2buildBlueprintWrapContext) ModuleSubDir(module blueprint.Module) string {
-	return ctx.bpCtx.ModuleSubDir(module)
-}
-
-func (ctx *bp2buildBlueprintWrapContext) ModuleType(module blueprint.Module) string {
-	return ctx.bpCtx.ModuleType(module)
-}
-
-func (ctx *bp2buildBlueprintWrapContext) VisitAllModulesBlueprint(visit func(blueprint.Module)) {
-	ctx.bpCtx.VisitAllModules(visit)
-}
-
-func (ctx *bp2buildBlueprintWrapContext) VisitDirectDeps(module android.Module, visit func(android.Module)) {
-	ctx.bpCtx.VisitDirectDeps(module, func(m blueprint.Module) {
-		if aModule, ok := m.(android.Module); ok {
-			visit(aModule)
-		}
-	})
-}
diff --git a/cc/config/global.go b/cc/config/global.go
index d47e0ce..c34f936 100644
--- a/cc/config/global.go
+++ b/cc/config/global.go
@@ -90,9 +90,12 @@
 		"-Wl,--warn-shared-textrel",
 		"-Wl,--fatal-warnings",
 		"-Wl,--no-undefined-version",
+		// TODO: Eventually we should link against a libunwind.a with hidden symbols, and then these
+		// --exclude-libs arguments can be removed.
 		"-Wl,--exclude-libs,libgcc.a",
 		"-Wl,--exclude-libs,libgcc_stripped.a",
 		"-Wl,--exclude-libs,libunwind_llvm.a",
+		"-Wl,--exclude-libs,libunwind.a",
 	}
 
 	deviceGlobalLldflags = append(ClangFilterUnknownLldflags(deviceGlobalLdflags),
diff --git a/cc/stl.go b/cc/stl.go
index 406fa3a..75fab17 100644
--- a/cc/stl.go
+++ b/cc/stl.go
@@ -140,11 +140,7 @@
 }
 
 func staticUnwinder(ctx android.BaseModuleContext) string {
-	if ctx.Arch().ArchType == android.Arm {
-		return "libunwind_llvm"
-	} else {
-		return "libgcc_stripped"
-	}
+	return "libunwind"
 }
 
 func (stl *stl) deps(ctx BaseModuleContext, deps Deps) Deps {
@@ -192,6 +188,7 @@
 		if needsLibAndroidSupport(ctx) {
 			deps.StaticLibs = append(deps.StaticLibs, "ndk_libandroid_support")
 		}
+		// TODO: Switch the NDK over to the LLVM unwinder for non-arm32 architectures.
 		if ctx.Arch().ArchType == android.Arm {
 			deps.StaticLibs = append(deps.StaticLibs, "ndk_libunwind")
 		} else {
@@ -231,10 +228,6 @@
 					// Use Win32 threads in libc++.
 					"-D_LIBCPP_HAS_THREAD_API_WIN32")
 			}
-		} else {
-			if ctx.Arch().ArchType == android.Arm {
-				flags.Local.LdFlags = append(flags.Local.LdFlags, "-Wl,--exclude-libs,libunwind_llvm.a")
-			}
 		}
 	case "libstdc++":
 		// Nothing
diff --git a/cc/testing.go b/cc/testing.go
index 903f76c..dc9a59d 100644
--- a/cc/testing.go
+++ b/cc/testing.go
@@ -110,6 +110,16 @@
 		}
 
 		toolchain_library {
+			name: "libunwind",
+			defaults: ["linux_bionic_supported"],
+			vendor_available: true,
+			product_available: true,
+			recovery_available: true,
+			native_bridge_supported: true,
+			src: "",
+		}
+
+		toolchain_library {
 			name: "libclang_rt.fuzzer-arm-android",
 			vendor_available: true,
 			product_available: true,
diff --git a/cmd/soong_build/main.go b/cmd/soong_build/main.go
index 907bed3..1d5e7b3 100644
--- a/cmd/soong_build/main.go
+++ b/cmd/soong_build/main.go
@@ -23,6 +23,7 @@
 	"github.com/google/blueprint/bootstrap"
 
 	"android/soong/android"
+	"android/soong/bp2build"
 )
 
 var (
@@ -54,18 +55,12 @@
 // bazelConversionRequested checks that the user is intending to convert
 // Blueprint to Bazel BUILD files.
 func bazelConversionRequested(configuration android.Config) bool {
-	return configuration.IsEnvTrue("CONVERT_TO_BAZEL")
+	return configuration.IsEnvTrue("GENERATE_BAZEL_FILES")
 }
 
-func newContext(srcDir string, configuration android.Config) *android.Context {
+func newContext(configuration android.Config) *android.Context {
 	ctx := android.NewContext(configuration)
-	if bazelConversionRequested(configuration) {
-		// Register an alternate set of singletons and mutators for bazel
-		// conversion for Bazel conversion.
-		ctx.RegisterForBazelConversion()
-	} else {
-		ctx.Register()
-	}
+	ctx.Register()
 	if !shouldPrepareBuildActions(configuration) {
 		configuration.SetStopBefore(bootstrap.StopBeforePrepareBuildActions)
 	}
@@ -100,13 +95,22 @@
 		// enabled even if it completed successfully.
 		extraNinjaDeps = append(extraNinjaDeps, filepath.Join(configuration.BuildDir(), "always_rerun_for_delve"))
 	}
+
+	if bazelConversionRequested(configuration) {
+		// Run the alternate pipeline of bp2build mutators and singleton to convert Blueprint to BUILD files
+		// before everything else.
+		runBp2Build(configuration, extraNinjaDeps)
+		// Short-circuit and return.
+		return
+	}
+
 	if configuration.BazelContext.BazelEnabled() {
 		// Bazel-enabled mode. Soong runs in two passes.
 		// First pass: Analyze the build tree, but only store all bazel commands
 		// needed to correctly evaluate the tree in the second pass.
 		// TODO(cparsons): Don't output any ninja file, as the second pass will overwrite
 		// the incorrect results from the first pass, and file I/O is expensive.
-		firstCtx := newContext(srcDir, configuration)
+		firstCtx := newContext(configuration)
 		configuration.SetStopBefore(bootstrap.StopBeforeWriteNinja)
 		bootstrap.Main(firstCtx.Context, configuration, extraNinjaDeps...)
 		// Invoke bazel commands and save results for second pass.
@@ -120,10 +124,10 @@
 			fmt.Fprintf(os.Stderr, "%s", err)
 			os.Exit(1)
 		}
-		ctx = newContext(srcDir, secondPassConfig)
+		ctx = newContext(secondPassConfig)
 		bootstrap.Main(ctx.Context, secondPassConfig, extraNinjaDeps...)
 	} else {
-		ctx = newContext(srcDir, configuration)
+		ctx = newContext(configuration)
 		bootstrap.Main(ctx.Context, configuration, extraNinjaDeps...)
 	}
 
@@ -154,6 +158,22 @@
 	}
 }
 
+// Run Soong in the bp2build mode. This creates a standalone context that registers
+// an alternate pipeline of mutators and singletons specifically for generating
+// Bazel BUILD files instead of Ninja files.
+func runBp2Build(configuration android.Config, extraNinjaDeps []string) {
+	// Register an alternate set of singletons and mutators for bazel
+	// conversion for Bazel conversion.
+	bp2buildCtx := android.NewContext(configuration)
+	bp2buildCtx.RegisterForBazelConversion()
+	configuration.SetStopBefore(bootstrap.StopBeforePrepareBuildActions)
+	bp2buildCtx.SetNameInterface(newNameResolver(configuration))
+	bootstrap.Main(bp2buildCtx.Context, configuration, extraNinjaDeps...)
+
+	codegenContext := bp2build.NewCodegenContext(configuration, *bp2buildCtx)
+	bp2build.Codegen(codegenContext)
+}
+
 // shouldPrepareBuildActions reads configuration and flags if build actions
 // should be generated.
 func shouldPrepareBuildActions(configuration android.Config) bool {
diff --git a/cmd/soong_build/queryview.go b/cmd/soong_build/queryview.go
index 3657ea8..79ea94a 100644
--- a/cmd/soong_build/queryview.go
+++ b/cmd/soong_build/queryview.go
@@ -20,48 +20,11 @@
 	"io/ioutil"
 	"os"
 	"path/filepath"
-
-	"github.com/google/blueprint"
 )
 
-type queryviewContext struct {
-	bpCtx *blueprint.Context
-}
-
-func (ctx *queryviewContext) ModuleName(module blueprint.Module) string {
-	return ctx.bpCtx.ModuleName(module)
-}
-
-func (ctx *queryviewContext) ModuleDir(module blueprint.Module) string {
-	return ctx.bpCtx.ModuleDir(module)
-}
-
-func (ctx *queryviewContext) ModuleSubDir(module blueprint.Module) string {
-	return ctx.bpCtx.ModuleSubDir(module)
-}
-
-func (ctx *queryviewContext) ModuleType(module blueprint.Module) string {
-	return ctx.bpCtx.ModuleType(module)
-}
-
-func (ctx *queryviewContext) VisitAllModulesBlueprint(visit func(blueprint.Module)) {
-	ctx.bpCtx.VisitAllModules(visit)
-}
-
-func (ctx *queryviewContext) VisitDirectDeps(module android.Module, visit func(android.Module)) {
-	ctx.bpCtx.VisitDirectDeps(module, func(m blueprint.Module) {
-		if aModule, ok := m.(android.Module); ok {
-			visit(aModule)
-		}
-	})
-}
-
 func createBazelQueryView(ctx *android.Context, bazelQueryViewDir string) error {
-	qvCtx := queryviewContext{
-		bpCtx: ctx.Context,
-	}
 	ruleShims := bp2build.CreateRuleShims(android.ModuleTypeFactories())
-	buildToTargets := bp2build.GenerateSoongModuleTargets(&qvCtx)
+	buildToTargets := bp2build.GenerateSoongModuleTargets(*ctx)
 
 	filesToWrite := bp2build.CreateBazelFiles(ruleShims, buildToTargets)
 	for _, f := range filesToWrite {
diff --git a/java/dexpreopt_bootjars.go b/java/dexpreopt_bootjars.go
index 062005b..80211fd 100644
--- a/java/dexpreopt_bootjars.go
+++ b/java/dexpreopt_bootjars.go
@@ -422,16 +422,19 @@
 // Note that the same jar may occur in multiple modules.
 // This logic is tested in the apex package to avoid import cycle apex <-> java.
 func getBootImageJar(ctx android.SingletonContext, image *bootImageConfig, module android.Module) (int, android.Path) {
-	// Ignore any module that is not listed in the boot image configuration.
 	name := ctx.ModuleName(module)
+
+	// Strip a prebuilt_ prefix so that this can access the dex jar from a prebuilt module.
+	name = android.RemoveOptionalPrebuiltPrefix(name)
+
+	// Ignore any module that is not listed in the boot image configuration.
 	index := image.modules.IndexOfJar(name)
 	if index == -1 {
 		return -1, nil
 	}
 
-	// It is an error if a module configured in the boot image does not support
-	// accessing the dex jar. This is safe because every module that has the same
-	// name has to have the same module type.
+	// It is an error if a module configured in the boot image does not support accessing the dex jar.
+	// This is safe because every module that has the same name has to have the same module type.
 	jar, hasJar := module.(interface{ DexJarBuildPath() android.Path })
 	if !hasJar {
 		ctx.Errorf("module %q configured in boot image %q does not support accessing dex jar", module, image.name)
diff --git a/java/java.go b/java/java.go
index 99bc55d..3c6146b 100644
--- a/java/java.go
+++ b/java/java.go
@@ -2859,6 +2859,7 @@
 	j.classLoaderContexts = make(dexpreopt.ClassLoaderContextMap)
 
 	var flags javaBuilderFlags
+	var deapexerModule android.Module
 
 	ctx.VisitDirectDeps(func(module android.Module) {
 		tag := ctx.OtherModuleDependencyTag(module)
@@ -2879,6 +2880,11 @@
 		}
 
 		addCLCFromDep(ctx, module, j.classLoaderContexts)
+
+		// Save away the `deapexer` module on which this depends, if any.
+		if tag == android.DeapexerTag {
+			deapexerModule = module
+		}
 	})
 
 	if Bool(j.properties.Installable) {
@@ -2888,39 +2894,60 @@
 
 	j.exportAidlIncludeDirs = android.PathsForModuleSrc(ctx, j.properties.Aidl.Export_include_dirs)
 
-	if ctx.Device() && Bool(j.dexProperties.Compile_dex) {
-		sdkDep := decodeSdkDep(ctx, sdkContext(j))
-		if sdkDep.invalidVersion {
-			ctx.AddMissingDependencies(sdkDep.bootclasspath)
-			ctx.AddMissingDependencies(sdkDep.java9Classpath)
-		} else if sdkDep.useFiles {
-			// sdkDep.jar is actually equivalent to turbine header.jar.
-			flags.classpath = append(flags.classpath, sdkDep.jars...)
+	if ctx.Device() {
+		// If this is a variant created for a prebuilt_apex then use the dex implementation jar
+		// obtained from the associated deapexer module.
+		ai := ctx.Provider(android.ApexInfoProvider).(android.ApexInfo)
+		if ai.ForPrebuiltApex {
+			if deapexerModule == nil {
+				// This should never happen as a variant for a prebuilt_apex is only created if the
+				// deapxer module has been configured to export the dex implementation jar for this module.
+				ctx.ModuleErrorf("internal error: module %q does not depend on a `deapexer` module for prebuilt_apex %q",
+					j.Name(), ai.ApexVariationName)
+			}
+
+			// Get the path of the dex implementation jar from the `deapexer` module.
+			di := ctx.OtherModuleProvider(deapexerModule, android.DeapexerProvider).(android.DeapexerInfo)
+			j.dexJarFile = di.PrebuiltExportPath(j.BaseModuleName(), ".dexjar")
+			if j.dexJarFile == nil {
+				// This should never happen as a variant for a prebuilt_apex is only created if the
+				// prebuilt_apex has been configured to export the java library dex file.
+				ctx.ModuleErrorf("internal error: no dex implementation jar available from prebuilt_apex %q", deapexerModule.Name())
+			}
+		} else if Bool(j.dexProperties.Compile_dex) {
+			sdkDep := decodeSdkDep(ctx, sdkContext(j))
+			if sdkDep.invalidVersion {
+				ctx.AddMissingDependencies(sdkDep.bootclasspath)
+				ctx.AddMissingDependencies(sdkDep.java9Classpath)
+			} else if sdkDep.useFiles {
+				// sdkDep.jar is actually equivalent to turbine header.jar.
+				flags.classpath = append(flags.classpath, sdkDep.jars...)
+			}
+
+			// Dex compilation
+
+			j.dexpreopter.installPath = android.PathForModuleInstall(ctx, "framework", jarName)
+			if j.dexProperties.Uncompress_dex == nil {
+				// If the value was not force-set by the user, use reasonable default based on the module.
+				j.dexProperties.Uncompress_dex = proptools.BoolPtr(shouldUncompressDex(ctx, &j.dexpreopter))
+			}
+			j.dexpreopter.uncompressedDex = *j.dexProperties.Uncompress_dex
+
+			var dexOutputFile android.ModuleOutPath
+			dexOutputFile = j.dexer.compileDex(ctx, flags, j.minSdkVersion(), outputFile, jarName)
+			if ctx.Failed() {
+				return
+			}
+
+			configurationName := j.BaseModuleName()
+			primary := j.Prebuilt().UsePrebuilt()
+
+			// Hidden API CSV generation and dex encoding
+			dexOutputFile = j.hiddenAPI.hiddenAPI(ctx, configurationName, primary, dexOutputFile, outputFile,
+				proptools.Bool(j.dexProperties.Uncompress_dex))
+
+			j.dexJarFile = dexOutputFile
 		}
-
-		// Dex compilation
-
-		j.dexpreopter.installPath = android.PathForModuleInstall(ctx, "framework", jarName)
-		if j.dexProperties.Uncompress_dex == nil {
-			// If the value was not force-set by the user, use reasonable default based on the module.
-			j.dexProperties.Uncompress_dex = proptools.BoolPtr(shouldUncompressDex(ctx, &j.dexpreopter))
-		}
-		j.dexpreopter.uncompressedDex = *j.dexProperties.Uncompress_dex
-
-		var dexOutputFile android.ModuleOutPath
-		dexOutputFile = j.dexer.compileDex(ctx, flags, j.minSdkVersion(), outputFile, jarName)
-		if ctx.Failed() {
-			return
-		}
-
-		configurationName := j.BaseModuleName()
-		primary := j.Prebuilt().UsePrebuilt()
-
-		// Hidden API CSV generation and dex encoding
-		dexOutputFile = j.hiddenAPI.hiddenAPI(ctx, configurationName, primary, dexOutputFile, outputFile,
-			proptools.Bool(j.dexProperties.Uncompress_dex))
-
-		j.dexJarFile = dexOutputFile
 	}
 }
 
diff --git a/java/java_test.go b/java/java_test.go
index a2466f9..1c0738f 100644
--- a/java/java_test.go
+++ b/java/java_test.go
@@ -867,83 +867,43 @@
 		return config
 	}
 
-	isValidDependency := func(configInfo testConfigInfo) bool {
-		if configInfo.enforceVendorInterface == false {
-			return true
-		}
-
-		if configInfo.enforceJavaSdkLibraryCheck == false {
-			return true
-		}
-
-		if inList("bar", configInfo.allowList) {
-			return true
-		}
-
-		if configInfo.libraryType == "java_library" {
-			if configInfo.fromPartition != configInfo.toPartition {
-				if !configInfo.enforceProductInterface &&
-					((configInfo.fromPartition == "system" && configInfo.toPartition == "product") ||
-						(configInfo.fromPartition == "product" && configInfo.toPartition == "system")) {
-					return true
-				}
-				return false
-			}
-		}
-
-		return true
-	}
-
 	errorMessage := "is not allowed across the partitions"
 
-	allPartitionCombinations := func() [][2]string {
-		var result [][2]string
-		partitions := []string{"system", "vendor", "product"}
+	testJavaWithConfig(t, createTestConfig(testConfigInfo{
+		libraryType:                "java_library",
+		fromPartition:              "product",
+		toPartition:                "system",
+		enforceVendorInterface:     true,
+		enforceProductInterface:    true,
+		enforceJavaSdkLibraryCheck: false,
+	}))
 
-		for _, fromPartition := range partitions {
-			for _, toPartition := range partitions {
-				result = append(result, [2]string{fromPartition, toPartition})
-			}
-		}
+	testJavaWithConfig(t, createTestConfig(testConfigInfo{
+		libraryType:                "java_library",
+		fromPartition:              "product",
+		toPartition:                "system",
+		enforceVendorInterface:     true,
+		enforceProductInterface:    false,
+		enforceJavaSdkLibraryCheck: true,
+	}))
 
-		return result
-	}
+	testJavaErrorWithConfig(t, errorMessage, createTestConfig(testConfigInfo{
+		libraryType:                "java_library",
+		fromPartition:              "product",
+		toPartition:                "system",
+		enforceVendorInterface:     true,
+		enforceProductInterface:    true,
+		enforceJavaSdkLibraryCheck: true,
+	}))
 
-	allFlagCombinations := func() [][3]bool {
-		var result [][3]bool
-		flagValues := [2]bool{false, true}
-
-		for _, vendorInterface := range flagValues {
-			for _, productInterface := range flagValues {
-				for _, enableEnforce := range flagValues {
-					result = append(result, [3]bool{vendorInterface, productInterface, enableEnforce})
-				}
-			}
-		}
-
-		return result
-	}
-
-	for _, libraryType := range []string{"java_library", "java_sdk_library"} {
-		for _, partitionValues := range allPartitionCombinations() {
-			for _, flagValues := range allFlagCombinations() {
-				testInfo := testConfigInfo{
-					libraryType:                libraryType,
-					fromPartition:              partitionValues[0],
-					toPartition:                partitionValues[1],
-					enforceVendorInterface:     flagValues[0],
-					enforceProductInterface:    flagValues[1],
-					enforceJavaSdkLibraryCheck: flagValues[2],
-				}
-
-				if isValidDependency(testInfo) {
-					testJavaWithConfig(t, createTestConfig(testInfo))
-				} else {
-					testJavaErrorWithConfig(t, errorMessage, createTestConfig(testInfo))
-				}
-			}
-		}
-	}
+	testJavaErrorWithConfig(t, errorMessage, createTestConfig(testConfigInfo{
+		libraryType:                "java_library",
+		fromPartition:              "vendor",
+		toPartition:                "system",
+		enforceVendorInterface:     true,
+		enforceProductInterface:    true,
+		enforceJavaSdkLibraryCheck: true,
+	}))
 
 	testJavaWithConfig(t, createTestConfig(testConfigInfo{
 		libraryType:                "java_library",
@@ -958,11 +918,37 @@
 	testJavaErrorWithConfig(t, errorMessage, createTestConfig(testConfigInfo{
 		libraryType:                "java_library",
 		fromPartition:              "vendor",
+		toPartition:                "product",
+		enforceVendorInterface:     true,
+		enforceProductInterface:    true,
+		enforceJavaSdkLibraryCheck: true,
+	}))
+
+	testJavaWithConfig(t, createTestConfig(testConfigInfo{
+		libraryType:                "java_sdk_library",
+		fromPartition:              "product",
 		toPartition:                "system",
 		enforceVendorInterface:     true,
 		enforceProductInterface:    true,
 		enforceJavaSdkLibraryCheck: true,
-		allowList:                  []string{"foo"},
+	}))
+
+	testJavaWithConfig(t, createTestConfig(testConfigInfo{
+		libraryType:                "java_sdk_library",
+		fromPartition:              "vendor",
+		toPartition:                "system",
+		enforceVendorInterface:     true,
+		enforceProductInterface:    true,
+		enforceJavaSdkLibraryCheck: true,
+	}))
+
+	testJavaWithConfig(t, createTestConfig(testConfigInfo{
+		libraryType:                "java_sdk_library",
+		fromPartition:              "vendor",
+		toPartition:                "product",
+		enforceVendorInterface:     true,
+		enforceProductInterface:    true,
+		enforceJavaSdkLibraryCheck: true,
 	}))
 }
 
diff --git a/scripts/unpack-prebuilt-apex.sh b/scripts/unpack-prebuilt-apex.sh
new file mode 100755
index 0000000..1acdeb5
--- /dev/null
+++ b/scripts/unpack-prebuilt-apex.sh
@@ -0,0 +1,59 @@
+#!/bin/bash
+
+set -eu
+
+# Copyright 2020 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.
+
+# Tool to unpack an apex file and verify that the required files were extracted.
+if [ $# -lt 5 ]; then
+  echo "usage: $0 <deapaxer_path> <debugfs_path> <apex file> <output_dir> <required_files>+" >&2
+  exit 1
+fi
+
+DEAPEXER_PATH=$1
+DEBUGFS_PATH=$2
+APEX_FILE=$3
+OUTPUT_DIR=$4
+shift 4
+REQUIRED_PATHS=$@
+
+set -x 1
+
+rm -fr $OUTPUT_DIR
+mkdir -p $OUTPUT_DIR
+
+# Unpack the apex file contents.
+$DEAPEXER_PATH --debugfs_path $DEBUGFS_PATH extract $APEX_FILE $OUTPUT_DIR
+
+# Verify that the files that the build expects to be in the .apex file actually
+# exist, and make sure they have a fresh mtime to not confuse ninja.
+typeset -i FAILED=0
+for r in $REQUIRED_PATHS; do
+  if [ ! -f $r ]; then
+    echo "Required file $r not present in apex $APEX_FILE" >&2
+    FAILED=$FAILED+1
+  else
+    # TODO(http:/b/177646343) - deapexer extracts the files with a timestamp of 1 Jan 1970.
+    # touch the file so that ninja knows it has changed.
+    touch $r
+  fi
+done
+
+if [ $FAILED -gt 0 ]; then
+  echo "$FAILED required files were missing from $APEX_FILE" >&2
+  echo "Available files are:" >&2
+  find $OUTPUT_DIR -type f | sed "s|^|    |" >&2
+  exit 1
+fi
diff --git a/sysprop/sysprop_library.go b/sysprop/sysprop_library.go
index 38306ad..2ccce15 100644
--- a/sysprop/sysprop_library.go
+++ b/sysprop/sysprop_library.go
@@ -19,6 +19,7 @@
 import (
 	"fmt"
 	"io"
+	"os"
 	"path"
 	"sync"
 
@@ -125,8 +126,8 @@
 	properties syspropLibraryProperties
 
 	checkApiFileTimeStamp android.WritablePath
-	latestApiFile         android.Path
-	currentApiFile        android.Path
+	latestApiFile         android.OptionalPath
+	currentApiFile        android.OptionalPath
 	dumpedApiFile         android.WritablePath
 }
 
@@ -224,7 +225,7 @@
 	return proptools.Bool(m.properties.Public_stub)
 }
 
-func (m *syspropLibrary) CurrentSyspropApiFile() android.Path {
+func (m *syspropLibrary) CurrentSyspropApiFile() android.OptionalPath {
 	return m.currentApiFile
 }
 
@@ -243,8 +244,11 @@
 		return
 	}
 
-	m.currentApiFile = android.PathForSource(ctx, ctx.ModuleDir(), "api", baseModuleName+"-current.txt")
-	m.latestApiFile = android.PathForSource(ctx, ctx.ModuleDir(), "api", baseModuleName+"-latest.txt")
+	apiDirectoryPath := path.Join(ctx.ModuleDir(), "api")
+	currentApiFilePath := path.Join(apiDirectoryPath, baseModuleName+"-current.txt")
+	latestApiFilePath := path.Join(apiDirectoryPath, baseModuleName+"-latest.txt")
+	m.currentApiFile = android.ExistentPathForSource(ctx, currentApiFilePath)
+	m.latestApiFile = android.ExistentPathForSource(ctx, latestApiFilePath)
 
 	// dump API rule
 	rule := android.NewRuleBuilder(pctx, ctx)
@@ -258,19 +262,37 @@
 	// check API rule
 	rule = android.NewRuleBuilder(pctx, ctx)
 
+	// We allow that the API txt files don't exist, when the sysprop_library only contains internal
+	// properties. But we have to feed current api file and latest api file to the rule builder.
+	// Currently we can't get android.Path representing the null device, so we add any existing API
+	// txt files to implicits, and then directly feed string paths, rather than calling Input(Path)
+	// method.
+	var apiFileList android.Paths
+	currentApiArgument := os.DevNull
+	if m.currentApiFile.Valid() {
+		apiFileList = append(apiFileList, m.currentApiFile.Path())
+		currentApiArgument = m.currentApiFile.String()
+	}
+
+	latestApiArgument := os.DevNull
+	if m.latestApiFile.Valid() {
+		apiFileList = append(apiFileList, m.latestApiFile.Path())
+		latestApiArgument = m.latestApiFile.String()
+	}
+
 	// 1. compares current.txt to api-dump.txt
 	// current.txt should be identical to api-dump.txt.
 	msg := fmt.Sprintf(`\n******************************\n`+
 		`API of sysprop_library %s doesn't match with current.txt\n`+
 		`Please update current.txt by:\n`+
-		`m %s-dump-api && rm -rf %q && cp -f %q %q\n`+
+		`m %s-dump-api && mkdir -p %q && rm -rf %q && cp -f %q %q\n`+
 		`******************************\n`, baseModuleName, baseModuleName,
-		m.currentApiFile.String(), m.dumpedApiFile.String(), m.currentApiFile.String())
+		apiDirectoryPath, currentApiFilePath, m.dumpedApiFile.String(), currentApiFilePath)
 
 	rule.Command().
 		Text("( cmp").Flag("-s").
 		Input(m.dumpedApiFile).
-		Input(m.currentApiFile).
+		Text(currentApiArgument).
 		Text("|| ( echo").Flag("-e").
 		Flag(`"` + msg + `"`).
 		Text("; exit 38) )")
@@ -285,11 +307,12 @@
 	rule.Command().
 		Text("( ").
 		BuiltTool("sysprop_api_checker").
-		Input(m.latestApiFile).
-		Input(m.currentApiFile).
+		Text(latestApiArgument).
+		Text(currentApiArgument).
 		Text(" || ( echo").Flag("-e").
 		Flag(`"` + msg + `"`).
-		Text("; exit 38) )")
+		Text("; exit 38) )").
+		Implicits(apiFileList)
 
 	m.checkApiFileTimeStamp = android.PathForModuleOut(ctx, "check_api.timestamp")
 
@@ -393,31 +416,6 @@
 		ctx.PropertyErrorf("srcs", "sysprop_library must specify srcs")
 	}
 
-	missingApi := false
-
-	for _, txt := range []string{"-current.txt", "-latest.txt"} {
-		path := path.Join(ctx.ModuleDir(), "api", m.BaseModuleName()+txt)
-		file := android.ExistentPathForSource(ctx, path)
-		if !file.Valid() {
-			ctx.ModuleErrorf("API file %#v doesn't exist", path)
-			missingApi = true
-		}
-	}
-
-	if missingApi {
-		script := "build/soong/scripts/gen-sysprop-api-files.sh"
-		p := android.ExistentPathForSource(ctx, script)
-
-		if !p.Valid() {
-			panic(fmt.Sprintf("script file %s doesn't exist", script))
-		}
-
-		ctx.ModuleErrorf("One or more api files are missing. "+
-			"You can create them by:\n"+
-			"%s %q %q", script, ctx.ModuleDir(), m.BaseModuleName())
-		return
-	}
-
 	// ctx's Platform or Specific functions represent where this sysprop_library installed.
 	installedInSystem := ctx.Platform() || ctx.SystemExtSpecific()
 	installedInVendorOrOdm := ctx.SocSpecific() || ctx.DeviceSpecific()