Merge "Export dex implementation jars from prebuilt_apex" am: fe6147eb26 am: c022da2b2a am: bf4b8488e9

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/1523984

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I1ec430725444022e43e9532964fdf4134031158c

android/Android.bp

@@ -21,6 +21,7 @@ bootstrap_go_package {
         "bazel_handler.go",
         "config.go",
         "csuite_config.go",
+        "deapexer.go",
         "defaults.go",
         "defs.go",
         "depset_generic.go",

android/apex.go

@@ -64,6 +64,14 @@ type ApexInfo struct {
 	// 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 @@ func mergeApexVariations(ctx PathContext, apexInfos []ApexInfo) (merged []ApexIn
 	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 @@ const (
 // 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,

android/apex_test.go

@@ -20,6 +20,10 @@ import (
 )
 
 func Test_mergeApexVariations(t *testing.T) {
+	const (
+		ForPrebuiltApex    = true
+		NotForPrebuiltApex = false
+	)
 	tests := []struct {
 		name        string
 		in          []ApexInfo
@@ -29,10 +33,10 @@ func Test_mergeApexVariations(t *testing.T) {
 		{
 			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 @@ func Test_mergeApexVariations(t *testing.T) {
 		{
 			name: "merge",
 			in: []ApexInfo{
-				{"foo", "current", false, SdkRefs{{"baz", "1"}}, []string{"foo"}, nil},
+				{"foo", "current", false, SdkRefs{{"baz", "1"}}, []string{"foo"}, nil, NotForPrebuiltApex},
-				{"bar", "current", false, SdkRefs{{"baz", "1"}}, []string{"bar"}, nil},
+				{"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 @@ func Test_mergeApexVariations(t *testing.T) {
 		{
 			name: "don't merge version",
 			in: []ApexInfo{
-				{"foo", "current", false, nil, []string{"foo"}, nil},
+				{"foo", "current", false, nil, []string{"foo"}, nil, NotForPrebuiltApex},
-				{"bar", "30", false, nil, []string{"bar"}, nil},
+				{"bar", "30", false, nil, []string{"bar"}, nil, NotForPrebuiltApex},
 			},
 			wantMerged: []ApexInfo{
-				{"apex30", "30", false, nil, []string{"bar"}, nil},
+				{"apex30", "30", false, nil, []string{"bar"}, nil, NotForPrebuiltApex},
-				{"apex10000", "current", false, nil, []string{"foo"}, nil},
+				{"apex10000", "current", false, nil, []string{"foo"}, nil, NotForPrebuiltApex},
 			},
 			wantAliases: [][2]string{
 				{"bar", "apex30"},
@@ -69,11 +73,11 @@ func Test_mergeApexVariations(t *testing.T) {
 		{
 			name: "merge updatable",
 			in: []ApexInfo{
-				{"foo", "current", false, nil, []string{"foo"}, nil},
+				{"foo", "current", false, nil, []string{"foo"}, nil, NotForPrebuiltApex},
-				{"bar", "current", true, nil, []string{"bar"}, nil},
+				{"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 @@ func Test_mergeApexVariations(t *testing.T) {
 		{
 			name: "don't merge sdks",
 			in: []ApexInfo{
-				{"foo", "current", false, SdkRefs{{"baz", "1"}}, []string{"foo"}, nil},
+				{"foo", "current", false, SdkRefs{{"baz", "1"}}, []string{"foo"}, nil, NotForPrebuiltApex},
-				{"bar", "current", false, SdkRefs{{"baz", "2"}}, []string{"bar"}, nil},
+				{"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_2", "current", false, SdkRefs{{"baz", "2"}}, []string{"bar"}, nil, NotForPrebuiltApex},
-				{"apex10000_baz_1", "current", false, SdkRefs{{"baz", "1"}}, []string{"foo"}, nil},
+				{"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)

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{}

android/testing.go

@@ -469,6 +469,9 @@ func AndroidMkDataForTest(t *testing.T, config Config, bpPath string, mod bluepr
 //
 // 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/") {

apex/Android.bp

@@ -18,6 +18,7 @@ bootstrap_go_package {
         "apex.go",
         "apex_singleton.go",
         "builder.go",
+        "deapexer.go",
         "key.go",
         "prebuilt.go",
         "vndk.go",

apex/apex.go

@@ -1501,7 +1501,7 @@ func apexFileForFilesystem(ctx android.BaseModuleContext, buildFile android.Path
 	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.

apex/apex_test.go

@@ -190,6 +190,7 @@ func testApexContext(_ *testing.T, bp string, handlers ...testCustomizer) (*andr
 		"testdata/baz":                               nil,
 		"AppSet.apks":                                nil,
 		"foo.rs":                                     nil,
+		"libfoo.jar":                                 nil,
 	}
 
 	cc.GatherRequiredFilesForTest(fs)
@@ -4219,6 +4220,121 @@ func TestPrebuiltOverrides(t *testing.T) {
 	}
 }
 
+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 @@ func testNoUpdatableJarsInBootImage(t *testing.T, errmsg string, transformDexpre
 	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 @@ func testDexpreoptWithApexes(t *testing.T, bp, errmsg string, transformDexpreopt
 	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 @@ func testDexpreoptWithApexes(t *testing.T, bp, errmsg string, transformDexpreopt
 		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 @@ func TestNoUpdatableJarsInBootImage(t *testing.T) {
 		}
 		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) {

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())
+	}
+}

apex/prebuilt.go

@@ -157,6 +157,7 @@ func (p *ApexFileProperties) selectSource(ctx android.BottomUpMutatorContext) er
 
 type PrebuiltProperties struct {
 	ApexFileProperties
+	DeapexerProperties
 
 	Installable *bool
 	// Optional name for the installed apex. If unspecified, name of the
@@ -197,19 +198,152 @@ func (p *Prebuilt) Name() string {
 }
 
 // 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) {

java/dexpreopt_bootjars.go

@@ -422,16 +422,19 @@ func (d *dexpreoptBootJars) GenerateBuildActions(ctx android.SingletonContext) {
 // 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
+	// It is an error if a module configured in the boot image does not support accessing the dex jar.
-	// accessing the dex jar. This is safe because every module that has the same
+	// This is safe because every module that has the same name has to have the same module type.
-	// 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)

java/java.go

@@ -2859,6 +2859,7 @@ func (j *Import) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	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 @@ func (j *Import) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 		}
 
 		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 @@ func (j *Import) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 
 	j.exportAidlIncludeDirs = android.PathsForModuleSrc(ctx, j.properties.Aidl.Export_include_dirs)
 
-	if ctx.Device() && Bool(j.dexProperties.Compile_dex) {
+	if ctx.Device() {
-		sdkDep := decodeSdkDep(ctx, sdkContext(j))
+		// If this is a variant created for a prebuilt_apex then use the dex implementation jar
-		if sdkDep.invalidVersion {
+		// obtained from the associated deapexer module.
-			ctx.AddMissingDependencies(sdkDep.bootclasspath)
+		ai := ctx.Provider(android.ApexInfoProvider).(android.ApexInfo)
-			ctx.AddMissingDependencies(sdkDep.java9Classpath)
+		if ai.ForPrebuiltApex {
-		} else if sdkDep.useFiles {
+			if deapexerModule == nil {
-			// sdkDep.jar is actually equivalent to turbine header.jar.
+				// This should never happen as a variant for a prebuilt_apex is only created if the
-			flags.classpath = append(flags.classpath, sdkDep.jars...)
+				// 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
 	}
 }
 

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