Merge "Improve error reporting when depending on prebuilt implementation jar"

android/sdk.go

@@ -232,12 +232,6 @@ type SnapshotBuilder interface {
 	// relative path) and add the dest to the zip.
 	CopyToSnapshot(src Path, dest string)
 
-	// EmptyFile returns the path to an empty file.
-	//
-	// This can be used by sdk member types that need to create an empty file in the snapshot, simply
-	// pass the value returned from this to the CopyToSnapshot() method.
-	EmptyFile() Path
-
 	// UnzipToSnapshot generates a rule that will unzip the supplied zip into the snapshot relative
 	// directory destDir.
 	UnzipToSnapshot(zipPath Path, destDir string)
@@ -264,6 +258,14 @@ type SnapshotBuilder interface {
 	// See sdk/update.go for more information.
 	AddPrebuiltModule(member SdkMember, moduleType string) BpModule
 
+	// AddInternalModule creates a new module in the generated Android.bp file that can only be
+	// referenced by one of the other modules in the snapshot.
+	//
+	// The created module's name is constructed by concatenating the name of this member and the
+	// nameSuffix, separated by "-". It also has the visibility property set to "//visibility:private"
+	// to prevent it from being inadvertently accessed from outside the snapshot.
+	AddInternalModule(properties SdkMemberProperties, moduleType string, nameSuffix string) BpModule
+
 	// SdkMemberReferencePropertyTag returns a property tag to use when adding a property to a
 	// BpModule that contains references to other sdk members.
 	//
@@ -922,6 +924,12 @@ func RegisterSdkMemberType(memberType SdkMemberType) {
 //
 // Contains common properties that apply across many different member types.
 type SdkMemberPropertiesBase struct {
+	// The name of the member.
+	//
+	// Ignore this property during optimization. This is needed because this property is the same for
+	// all variants of a member and so would be optimized away if it was not ignored.
+	MemberName string `sdk:"ignore"`
+
 	// The number of unique os types supported by the member variants.
 	//
 	// If a member has a variant with more than one os type then it will need to differentiate
@@ -945,6 +953,10 @@ type SdkMemberPropertiesBase struct {
 	Compile_multilib string `android:"arch_variant"`
 }
 
+func (b *SdkMemberPropertiesBase) Name() string {
+	return b.MemberName
+}
+
 // OsPrefix returns the os prefix to use for any file paths in the sdk.
 //
 // Is an empty string if the member only provides variants for a single os type, otherwise
@@ -970,6 +982,8 @@ type SdkMemberProperties interface {
 	// Base returns the base structure.
 	Base() *SdkMemberPropertiesBase
 
+	Name() string
+
 	// PopulateFromVariant populates this structure with information from a module variant.
 	//
 	// It will typically be called once for each variant of a member module that the SDK depends upon.

java/invalid_implementation_jar.sh

@@ -0,0 +1,61 @@
+#!/bin/bash
+
+# Copyright 2022 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.
+
+# Script to detect and report an attempt to access an invalid implementation
+# jar.
+
+MOD=$1
+
+cat <<EOF
+
+    $MOD is a java_library that generates a jar file which must not be accessed
+    from outside the mainline module that provides it. If you are seeing this
+    message it means that you are incorrectly attempting to use the jar file
+    from a java_import prebuilt of $MOD.
+
+    This is most likely due to an incorrect dependency on $MOD in an Android.mk
+    or Android.bp file. Please remove that dependency and replace with
+    something more appropriate, e.g. a dependency on an API provided by the
+    module.
+
+    If you do not know where the extraneous dependency was added then you can
+    run the following command to find a list of all the paths from the target
+    which you are trying to build to the target which produced this error.
+
+        prebuilts/build-tools/linux-x86/bin/ninja -f out/combined-\${TARGET_PRODUCT}.ninja -t path <target> <invalid-jar>
+
+    Where <target> is the build target you specified on the command line which
+    produces this error and <invalid-jar> is the rule that failed with this
+    message. If you are specifying multiple build targets then you will need to
+    run the above command for every target until you find the cause.
+
+    The command will output one (of the possibly many) dependency paths from
+    <target> to <invalid-jar>, one file/phony target per line. e.g. it may
+    output something like this:
+
+        ....
+        out/soong/.intermediates/acme/broken/android_common/combined/broken.jar
+        out/soong/.intermediates/prebuilts/module_sdk/art/current/sdk/prebuilt_core-libart/android_common/combined/core-libart.jar
+        out/soong/.intermediates/prebuilts/module_sdk/art/current/sdk/art-module-sdk_core-libart-error/gen/this-file-will-never-be-created.jar
+
+    The last line is the failing target, the second to last line is a dependency
+    from the core-libart java_import onto the failing target, the third to last
+    line is the source of the dependency so you should look in acme/Android.bp
+    file for the "broken" module.
+
+EOF
+
+exit 1

java/java.go

@@ -86,11 +86,11 @@ func RegisterJavaSdkMemberTypes() {
 var (
 	// Supports adding java header libraries to module_exports and sdk.
 	javaHeaderLibsSdkMemberType = &librarySdkMemberType{
-		android.SdkMemberTypeBase{
+		SdkMemberTypeBase: android.SdkMemberTypeBase{
 			PropertyName: "java_header_libs",
 			SupportsSdk:  true,
 		},
-		func(_ android.SdkMemberContext, j *Library) android.Path {
+		jarToExportGetter: func(_ android.SdkMemberContext, j *Library) android.Path {
 			headerJars := j.HeaderJars()
 			if len(headerJars) != 1 {
 				panic(fmt.Errorf("there must be only one header jar from %q", j.Name()))
@@ -98,8 +98,8 @@ var (
 
 			return headerJars[0]
 		},
-		sdkSnapshotFilePathForJar,
+		snapshotPathGetter:    sdkSnapshotFilePathForJar,
-		copyEverythingToSnapshot,
+		onlyCopyJarToSnapshot: copyEverythingToSnapshot,
 	}
 
 	// Export implementation classes jar as part of the sdk.
@@ -113,12 +113,12 @@ var (
 
 	// Supports adding java implementation libraries to module_exports but not sdk.
 	javaLibsSdkMemberType = &librarySdkMemberType{
-		android.SdkMemberTypeBase{
+		SdkMemberTypeBase: android.SdkMemberTypeBase{
 			PropertyName: "java_libs",
 		},
-		exportImplementationClassesJar,
+		jarToExportGetter:     exportImplementationClassesJar,
-		sdkSnapshotFilePathForJar,
+		snapshotPathGetter:    sdkSnapshotFilePathForJar,
-		copyEverythingToSnapshot,
+		onlyCopyJarToSnapshot: copyEverythingToSnapshot,
 	}
 
 	snapshotRequiresImplementationJar = func(ctx android.SdkMemberContext) bool {
@@ -143,11 +143,11 @@ var (
 	// necessary. The java_boot_libs property to allow those modules to be exported as part of the
 	// sdk/module_exports without exposing any unnecessary information.
 	javaBootLibsSdkMemberType = &librarySdkMemberType{
-		android.SdkMemberTypeBase{
+		SdkMemberTypeBase: android.SdkMemberTypeBase{
 			PropertyName: "java_boot_libs",
 			SupportsSdk:  true,
 		},
-		func(ctx android.SdkMemberContext, j *Library) android.Path {
+		jarToExportGetter: func(ctx android.SdkMemberContext, j *Library) android.Path {
 			if snapshotRequiresImplementationJar(ctx) {
 				return exportImplementationClassesJar(ctx, j)
 			}
@@ -156,9 +156,9 @@ var (
 			// jar for use by dexpreopting and boot jars package check. They do not need to provide an
 			// actual implementation jar but the java_import will need a file that exists so just copy an
 			// empty file. Any attempt to use that file as a jar will cause a build error.
-			return ctx.SnapshotBuilder().EmptyFile()
+			return nil
 		},
-		func(ctx android.SdkMemberContext, osPrefix, name string) string {
+		snapshotPathGetter: func(ctx android.SdkMemberContext, osPrefix, name string) string {
 			if snapshotRequiresImplementationJar(ctx) {
 				return sdkSnapshotFilePathForJar(ctx, osPrefix, name)
 			}
@@ -168,7 +168,7 @@ var (
 			// TODO(b/175714559): Provide a proper error message in Soong not ninja.
 			return filepath.Join(osPrefix, "java_boot_libs", "snapshot", "jars", "are", "invalid", name+jarFileSuffix)
 		},
-		onlyCopyJarToSnapshot,
+		onlyCopyJarToSnapshot: onlyCopyJarToSnapshot,
 	}
 
 	// Supports adding java systemserver libraries to module_exports and sdk.
@@ -182,27 +182,27 @@ var (
 	// necessary. The java_systemserver_libs property to allow those modules to be exported as part of
 	// the sdk/module_exports without exposing any unnecessary information.
 	javaSystemserverLibsSdkMemberType = &librarySdkMemberType{
-		android.SdkMemberTypeBase{
+		SdkMemberTypeBase: android.SdkMemberTypeBase{
 			PropertyName: "java_systemserver_libs",
 			SupportsSdk:  true,
 
 			// This was only added in Tiramisu.
 			SupportedBuildReleaseSpecification: "Tiramisu+",
 		},
-		func(ctx android.SdkMemberContext, j *Library) android.Path {
+		jarToExportGetter: func(ctx android.SdkMemberContext, j *Library) android.Path {
 			// Java systemserver libs are only provided in the SDK to provide access to their dex
 			// implementation jar for use by dexpreopting. They do not need to provide an actual
 			// implementation jar but the java_import will need a file that exists so just copy an empty
 			// file. Any attempt to use that file as a jar will cause a build error.
-			return ctx.SnapshotBuilder().EmptyFile()
+			return nil
 		},
-		func(_ android.SdkMemberContext, osPrefix, name string) string {
+		snapshotPathGetter: func(_ android.SdkMemberContext, osPrefix, name string) string {
 			// Create a special name for the implementation jar to try and provide some useful information
 			// to a developer that attempts to compile against this.
 			// TODO(b/175714559): Provide a proper error message in Soong not ninja.
 			return filepath.Join(osPrefix, "java_systemserver_libs", "snapshot", "jars", "are", "invalid", name+jarFileSuffix)
 		},
-		onlyCopyJarToSnapshot,
+		onlyCopyJarToSnapshot: onlyCopyJarToSnapshot,
 	}
 
 	// Supports adding java test libraries to module_exports but not sdk.
@@ -232,7 +232,7 @@ type JavaInfo struct {
 	ImplementationAndResourcesJars android.Paths
 
 	// ImplementationJars is a list of jars that contain the implementations of classes in the
-	//module.
+	// module.
 	ImplementationJars android.Paths
 
 	// ResourceJars is a list of jars that contain the resources included in the module.
@@ -718,7 +718,8 @@ type librarySdkMemberType struct {
 	android.SdkMemberTypeBase
 
 	// Function to retrieve the appropriate output jar (implementation or header) from
-	// the library.
+	// the library, if this returns nil then it is assumed that the snapshot must not provide access
+	// to the jar.
 	jarToExportGetter func(ctx android.SdkMemberContext, j *Library) android.Path
 
 	// Function to compute the snapshot relative path to which the named library's
@@ -755,7 +756,11 @@ func (mt *librarySdkMemberType) CreateVariantPropertiesStruct() android.SdkMembe
 type librarySdkMemberProperties struct {
 	android.SdkMemberPropertiesBase
 
-	JarToExport     android.Path `android:"arch_variant"`
+	JarToExport android.Path `android:"arch_variant"`
+
+	// The path to a script to use when the jar is invalid.
+	InvalidJarScript android.Path
+
 	AidlIncludeDirs android.Paths
 
 	// The list of permitted packages that need to be passed to the prebuilts as they are used to
@@ -766,7 +771,15 @@ type librarySdkMemberProperties struct {
 func (p *librarySdkMemberProperties) PopulateFromVariant(ctx android.SdkMemberContext, variant android.Module) {
 	j := variant.(*Library)
 
-	p.JarToExport = ctx.MemberType().(*librarySdkMemberType).jarToExportGetter(ctx, j)
+	memberType := ctx.MemberType().(*librarySdkMemberType)
+	p.JarToExport = memberType.jarToExportGetter(ctx, j)
+
+	// If no jar was provided for export then disallow access to it completely.
+	if p.JarToExport == nil {
+		// Copy the script to prevent access to the jar into the snapshot.
+		p.InvalidJarScript = android.PathForSource(ctx.SdkModuleContext(),
+			"build/soong/java/invalid_implementation_jar.sh")
+	}
 
 	p.AidlIncludeDirs = j.AidlIncludeDirs()
 
@@ -789,6 +802,21 @@ func (p *librarySdkMemberProperties) AddToPropertySet(ctx android.SdkMemberConte
 		propertySet.AddProperty("jars", []string{snapshotRelativeJavaLibPath})
 	}
 
+	if scriptSrc := p.InvalidJarScript; scriptSrc != nil {
+		// Copy the script to prevent access to the jar into the snapshot.
+		scriptDest := filepath.Join("scripts", scriptSrc.Base())
+		builder.CopyToSnapshot(scriptSrc, scriptDest)
+
+		// Generate a genrule module that will invoke the script passing in the module name.
+		genrule := builder.AddInternalModule(p, "genrule", "error")
+		genRuleName := genrule.Name()
+		genrule.AddProperty("out", []string{"this-file-will-never-be-created.jar"})
+		genrule.AddProperty("tool_files", []string{scriptDest})
+		genrule.AddProperty("cmd", fmt.Sprintf("$(location %s) %s", scriptDest, p.Name()))
+
+		propertySet.AddPropertyWithTag("jars", []string{":" + genRuleName}, builder.SdkMemberReferencePropertyTag(true))
+	}
+
 	if len(p.PermittedPackages) > 0 {
 		propertySet.AddProperty("permitted_packages", p.PermittedPackages)
 	}
@@ -1650,7 +1678,7 @@ func (j *Import) DepsMutator(ctx android.BottomUpMutatorContext) {
 }
 
 func (j *Import) commonBuildActions(ctx android.ModuleContext) {
-	//TODO(b/231322772) these should come from Bazel once available
+	// TODO(b/231322772) these should come from Bazel once available
 	j.sdkVersion = j.SdkVersion(ctx)
 	j.minSdkVersion = j.MinSdkVersion(ctx)
 
@@ -2253,7 +2281,7 @@ func (m *Library) convertJavaResourcesAttributes(ctx android.TopDownMutatorConte
 		resources.Append(android.BazelLabelForModuleSrc(ctx, m.properties.Java_resources))
 	}
 
-	//TODO(b/179889880) handle case where glob includes files outside package
+	// TODO(b/179889880) handle case where glob includes files outside package
 	resDeps := ResourceDirsToFiles(
 		ctx,
 		m.properties.Java_resource_dirs,
@@ -2401,7 +2429,7 @@ func (m *Library) convertLibraryAttrsBp2Build(ctx android.TopDownMutatorContext)
 	}
 
 	epEnabled := m.properties.Errorprone.Enabled
-	//TODO(b/227504307) add configuration that depends on RUN_ERROR_PRONE environment variable
+	// TODO(b/227504307) add configuration that depends on RUN_ERROR_PRONE environment variable
 	if Bool(epEnabled) {
 		javacopts = append(javacopts, m.properties.Errorprone.Javacflags...)
 	}
@@ -2637,7 +2665,7 @@ func (i *Import) ProcessBazelQueryResponse(ctx android.ModuleContext) {
 		HeaderJars:                     android.PathsIfNonNil(i.combinedClasspathFile),
 		ImplementationAndResourcesJars: android.PathsIfNonNil(i.combinedClasspathFile),
 		ImplementationJars:             android.PathsIfNonNil(i.combinedClasspathFile),
-		//TODO(b/240308299) include AIDL information from Bazel
+		// TODO(b/240308299) include AIDL information from Bazel
 	})
 
 	i.maybeInstall(ctx, jarName, outputFile)

sdk/bootclasspath_fragment_sdk_test.go

@@ -169,7 +169,15 @@ java_import {
     prefer: false,
     visibility: ["//visibility:public"],
     apex_available: ["com.android.art"],
-    jars: ["java_boot_libs/snapshot/jars/are/invalid/core1.jar"],
+    jars: [":mysdk_core1-error"],
+}
+
+genrule {
+    name: "mysdk_core1-error",
+    visibility: ["//visibility:private"],
+    out: ["this-file-will-never-be-created.jar"],
+    tool_files: ["scripts/invalid_implementation_jar.sh"],
+    cmd: "$(location scripts/invalid_implementation_jar.sh) core1",
 }
 
 java_import {
@@ -177,7 +185,15 @@ java_import {
     prefer: false,
     visibility: ["//visibility:public"],
     apex_available: ["com.android.art"],
-    jars: ["java_boot_libs/snapshot/jars/are/invalid/core2.jar"],
+    jars: [":mysdk_core2-error"],
+}
+
+genrule {
+    name: "mysdk_core2-error",
+    visibility: ["//visibility:private"],
+    out: ["this-file-will-never-be-created.jar"],
+    tool_files: ["scripts/invalid_implementation_jar.sh"],
+    cmd: "$(location scripts/invalid_implementation_jar.sh) core2",
 }
 `),
 		checkAllCopyRules(`
@@ -187,8 +203,7 @@ java_import {
 .intermediates/mybootclasspathfragment/android_common/modular-hiddenapi/signature-patterns.csv -> hiddenapi/signature-patterns.csv
 .intermediates/mybootclasspathfragment/android_common/modular-hiddenapi/filtered-stub-flags.csv -> hiddenapi/filtered-stub-flags.csv
 .intermediates/mybootclasspathfragment/android_common/modular-hiddenapi/filtered-flags.csv -> hiddenapi/filtered-flags.csv
-.intermediates/mysdk/common_os/empty -> java_boot_libs/snapshot/jars/are/invalid/core1.jar
+build/soong/java/invalid_implementation_jar.sh -> scripts/invalid_implementation_jar.sh
-.intermediates/mysdk/common_os/empty -> java_boot_libs/snapshot/jars/are/invalid/core2.jar
 		`),
 		snapshotTestPreparer(checkSnapshotWithoutSource, preparerForSnapshot),
 
@@ -357,10 +372,18 @@ java_import {
     prefer: false,
     visibility: ["//visibility:public"],
     apex_available: ["myapex"],
-    jars: ["java_boot_libs/snapshot/jars/are/invalid/mybootlib.jar"],
+    jars: [":mysdk_mybootlib-error"],
     permitted_packages: ["mybootlib"],
 }
 
+genrule {
+    name: "mysdk_mybootlib-error",
+    visibility: ["//visibility:private"],
+    out: ["this-file-will-never-be-created.jar"],
+    tool_files: ["scripts/invalid_implementation_jar.sh"],
+    cmd: "$(location scripts/invalid_implementation_jar.sh) mybootlib",
+}
+
 java_sdk_library_import {
     name: "myothersdklibrary",
     prefer: false,
@@ -467,7 +490,7 @@ func TestSnapshotWithBootClasspathFragment_Contents(t *testing.T) {
 .intermediates/mybootclasspathfragment/android_common/modular-hiddenapi/signature-patterns.csv -> hiddenapi/signature-patterns.csv
 .intermediates/mybootclasspathfragment/android_common/modular-hiddenapi/filtered-stub-flags.csv -> hiddenapi/filtered-stub-flags.csv
 .intermediates/mybootclasspathfragment/android_common/modular-hiddenapi/filtered-flags.csv -> hiddenapi/filtered-flags.csv
-.intermediates/mysdk/common_os/empty -> java_boot_libs/snapshot/jars/are/invalid/mybootlib.jar
+build/soong/java/invalid_implementation_jar.sh -> scripts/invalid_implementation_jar.sh
 .intermediates/myothersdklibrary.stubs/android_common/javac/myothersdklibrary.stubs.jar -> sdk_library/public/myothersdklibrary-stubs.jar
 .intermediates/myothersdklibrary.stubs.source/android_common/metalava/myothersdklibrary.stubs.source_api.txt -> sdk_library/public/myothersdklibrary.txt
 .intermediates/myothersdklibrary.stubs.source/android_common/metalava/myothersdklibrary.stubs.source_removed.txt -> sdk_library/public/myothersdklibrary-removed.txt
@@ -487,7 +510,7 @@ func TestSnapshotWithBootClasspathFragment_Contents(t *testing.T) {
 .intermediates/mybootclasspathfragment/android_common_myapex/modular-hiddenapi/signature-patterns.csv -> hiddenapi/signature-patterns.csv
 .intermediates/mybootclasspathfragment/android_common_myapex/modular-hiddenapi/filtered-stub-flags.csv -> hiddenapi/filtered-stub-flags.csv
 .intermediates/mybootclasspathfragment/android_common_myapex/modular-hiddenapi/filtered-flags.csv -> hiddenapi/filtered-flags.csv
-.intermediates/mysdk/common_os/empty -> java_boot_libs/snapshot/jars/are/invalid/mybootlib.jar
+build/soong/java/invalid_implementation_jar.sh -> scripts/invalid_implementation_jar.sh
 .intermediates/myothersdklibrary.stubs/android_common/javac/myothersdklibrary.stubs.jar -> sdk_library/public/myothersdklibrary-stubs.jar
 .intermediates/myothersdklibrary.stubs.source/android_common/metalava/myothersdklibrary.stubs.source_api.txt -> sdk_library/public/myothersdklibrary.txt
 .intermediates/myothersdklibrary.stubs.source/android_common/metalava/myothersdklibrary.stubs.source_removed.txt -> sdk_library/public/myothersdklibrary-removed.txt
@@ -876,10 +899,18 @@ java_import {
     prefer: false,
     visibility: ["//visibility:public"],
     apex_available: ["myapex"],
-    jars: ["java_boot_libs/snapshot/jars/are/invalid/mybootlib.jar"],
+    jars: [":mysdk_mybootlib-error"],
     permitted_packages: ["mybootlib"],
 }
 
+genrule {
+    name: "mysdk_mybootlib-error",
+    visibility: ["//visibility:private"],
+    out: ["this-file-will-never-be-created.jar"],
+    tool_files: ["scripts/invalid_implementation_jar.sh"],
+    cmd: "$(location scripts/invalid_implementation_jar.sh) mybootlib",
+}
+
 java_sdk_library_import {
     name: "mynewlibrary",
     prefer: false,
@@ -930,7 +961,7 @@ my-unsupported-packages.txt -> hiddenapi/my-unsupported-packages.txt
 .intermediates/mybootclasspathfragment/android_common/modular-hiddenapi/signature-patterns.csv -> hiddenapi/signature-patterns.csv
 .intermediates/mybootclasspathfragment/android_common/modular-hiddenapi/filtered-stub-flags.csv -> hiddenapi/filtered-stub-flags.csv
 .intermediates/mybootclasspathfragment/android_common/modular-hiddenapi/filtered-flags.csv -> hiddenapi/filtered-flags.csv
-.intermediates/mysdk/common_os/empty -> java_boot_libs/snapshot/jars/are/invalid/mybootlib.jar
+build/soong/java/invalid_implementation_jar.sh -> scripts/invalid_implementation_jar.sh
 .intermediates/mynewlibrary.stubs/android_common/javac/mynewlibrary.stubs.jar -> sdk_library/public/mynewlibrary-stubs.jar
 .intermediates/mynewlibrary.stubs.source/android_common/metalava/mynewlibrary.stubs.source_api.txt -> sdk_library/public/mynewlibrary.txt
 .intermediates/mynewlibrary.stubs.source/android_common/metalava/mynewlibrary.stubs.source_removed.txt -> sdk_library/public/mynewlibrary-removed.txt

sdk/java_sdk_test.go

@@ -19,11 +19,13 @@ import (
 	"testing"
 
 	"android/soong/android"
+	"android/soong/genrule"
 	"android/soong/java"
 )
 
 var prepareForSdkTestWithJava = android.GroupFixturePreparers(
 	java.PrepareForTestWithJavaBuildComponents,
+	genrule.PrepareForTestWithGenRuleBuildComponents,
 	PrepareForTestWithSdkBuildComponents,
 
 	// Ensure that all source paths are provided. This helps ensure that the snapshot generation is
@@ -34,6 +36,7 @@ var prepareForSdkTestWithJava = android.GroupFixturePreparers(
 	// Files needs by most of the tests.
 	android.MockFS{
 		"Test.java": nil,
+		"build/soong/java/invalid_implementation_jar.sh": nil,
 	}.AddToFixture(),
 )
 
@@ -288,18 +291,26 @@ java_import {
     prefer: false,
     visibility: ["//visibility:public"],
     apex_available: ["//apex_available:platform"],
-    jars: ["java_boot_libs/snapshot/jars/are/invalid/myjavalib.jar"],
+    jars: [":mysdk_myjavalib-error"],
     permitted_packages: ["pkg.myjavalib"],
 }
+
+genrule {
+    name: "mysdk_myjavalib-error",
+    visibility: ["//visibility:private"],
+    out: ["this-file-will-never-be-created.jar"],
+    tool_files: ["scripts/invalid_implementation_jar.sh"],
+    cmd: "$(location scripts/invalid_implementation_jar.sh) myjavalib",
+}
 `),
 		checkAllCopyRules(`
-.intermediates/mysdk/common_os/empty -> java_boot_libs/snapshot/jars/are/invalid/myjavalib.jar
+build/soong/java/invalid_implementation_jar.sh -> scripts/invalid_implementation_jar.sh
 `),
 	)
 }
 
 func TestSnapshotWithJavaBootLibrary_UpdatableMedia(t *testing.T) {
-	runTest := func(t *testing.T, targetBuildRelease, expectedJarPath, expectedCopyRule string) {
+	runTest := func(t *testing.T, targetBuildRelease, expectedJarPath, expectedGenRule, expectedCopyRule string) {
 		result := android.GroupFixturePreparers(
 			prepareForSdkTestWithJava,
 			android.FixtureMergeEnv(map[string]string{
@@ -334,20 +345,27 @@ java_import {
     jars: ["%s"],
     permitted_packages: ["pkg.media"],
 }
-`, expectedJarPath)),
+%s`, expectedJarPath, expectedGenRule)),
 			checkAllCopyRules(expectedCopyRule),
 		)
 	}
 
 	t.Run("updatable-media in S", func(t *testing.T) {
-		runTest(t, "S", "java/updatable-media.jar", `
+		runTest(t, "S", "java/updatable-media.jar", "", `
 .intermediates/updatable-media/android_common/package-check/updatable-media.jar -> java/updatable-media.jar
 `)
 	})
 
 	t.Run("updatable-media in T", func(t *testing.T) {
-		runTest(t, "Tiramisu", "java_boot_libs/snapshot/jars/are/invalid/updatable-media.jar", `
+		runTest(t, "Tiramisu", ":mysdk_updatable-media-error", `
-.intermediates/mysdk/common_os/empty -> java_boot_libs/snapshot/jars/are/invalid/updatable-media.jar
+genrule {
+    name: "mysdk_updatable-media-error",
+    visibility: ["//visibility:private"],
+    out: ["this-file-will-never-be-created.jar"],
+    tool_files: ["scripts/invalid_implementation_jar.sh"],
+    cmd: "$(location scripts/invalid_implementation_jar.sh) updatable-media",
+}`, `
+build/soong/java/invalid_implementation_jar.sh -> scripts/invalid_implementation_jar.sh
 `)
 	})
 }
@@ -389,12 +407,20 @@ java_import {
     prefer: false,
     visibility: ["//visibility:public"],
     apex_available: ["//apex_available:platform"],
-    jars: ["java_systemserver_libs/snapshot/jars/are/invalid/myjavalib.jar"],
+    jars: [":myexports_myjavalib-error"],
     permitted_packages: ["pkg.myjavalib"],
 }
+
+genrule {
+    name: "myexports_myjavalib-error",
+    visibility: ["//visibility:private"],
+    out: ["this-file-will-never-be-created.jar"],
+    tool_files: ["scripts/invalid_implementation_jar.sh"],
+    cmd: "$(location scripts/invalid_implementation_jar.sh) myjavalib",
+}
 `),
 		checkAllCopyRules(`
-.intermediates/myexports/common_os/empty -> java_systemserver_libs/snapshot/jars/are/invalid/myjavalib.jar
+build/soong/java/invalid_implementation_jar.sh -> scripts/invalid_implementation_jar.sh
 `),
 	)
 }

sdk/systemserverclasspath_fragment_sdk_test.go

@@ -119,10 +119,18 @@ java_import {
     prefer: false,
     visibility: ["//visibility:public"],
     apex_available: ["myapex"],
-    jars: ["java_systemserver_libs/snapshot/jars/are/invalid/mylib.jar"],
+    jars: [":mysdk_mylib-error"],
     permitted_packages: ["mylib"],
 }
 
+genrule {
+    name: "mysdk_mylib-error",
+    visibility: ["//visibility:private"],
+    out: ["this-file-will-never-be-created.jar"],
+    tool_files: ["scripts/invalid_implementation_jar.sh"],
+    cmd: "$(location scripts/invalid_implementation_jar.sh) mylib",
+}
+
 prebuilt_systemserverclasspath_fragment {
     name: "mysystemserverclasspathfragment",
     prefer: false,
@@ -180,10 +188,18 @@ java_import {
     prefer: false,
     visibility: ["//visibility:public"],
     apex_available: ["myapex"],
-    jars: ["java_systemserver_libs/snapshot/jars/are/invalid/mylib.jar"],
+    jars: [":mysdk_mylib-error"],
     permitted_packages: ["mylib"],
 }
 
+genrule {
+    name: "mysdk_mylib-error",
+    visibility: ["//visibility:private"],
+    out: ["this-file-will-never-be-created.jar"],
+    tool_files: ["scripts/invalid_implementation_jar.sh"],
+    cmd: "$(location scripts/invalid_implementation_jar.sh) mylib",
+}
+
 prebuilt_systemserverclasspath_fragment {
     name: "mysystemserverclasspathfragment",
     prefer: false,

sdk/update.go

@@ -1049,9 +1049,6 @@ type snapshotBuilder struct {
 	filesToZip  android.Paths
 	zipsToMerge android.Paths
 
-	// The path to an empty file.
-	emptyFile android.WritablePath
-
 	prebuiltModules map[string]*bpModule
 	prebuiltOrder   []*bpModule
 
@@ -1111,19 +1108,6 @@ func (s *snapshotBuilder) UnzipToSnapshot(zipPath android.Path, destDir string)
 	s.zipsToMerge = append(s.zipsToMerge, tmpZipPath)
 }
 
-func (s *snapshotBuilder) EmptyFile() android.Path {
-	if s.emptyFile == nil {
-		ctx := s.ctx
-		s.emptyFile = android.PathForModuleOut(ctx, "empty")
-		s.ctx.Build(pctx, android.BuildParams{
-			Rule:   android.Touch,
-			Output: s.emptyFile,
-		})
-	}
-
-	return s.emptyFile
-}
-
 func (s *snapshotBuilder) AddPrebuiltModule(member android.SdkMember, moduleType string) android.BpModule {
 	name := member.Name()
 	if s.prebuiltModules[name] != nil {
@@ -1200,6 +1184,24 @@ func (s *snapshotBuilder) AddPrebuiltModule(member android.SdkMember, moduleType
 	return m
 }
 
+func (s *snapshotBuilder) AddInternalModule(properties android.SdkMemberProperties, moduleType string, nameSuffix string) android.BpModule {
+	name := properties.Name() + "-" + nameSuffix
+
+	if s.prebuiltModules[name] != nil {
+		panic(fmt.Sprintf("Duplicate module detected, module %s has already been added", name))
+	}
+
+	m := s.bpFile.newModule(moduleType)
+	m.AddProperty("name", name)
+	m.AddProperty("visibility", []string{"//visibility:private"})
+
+	s.prebuiltModules[name] = m
+	s.prebuiltOrder = append(s.prebuiltOrder, m)
+
+	s.allMembersByName[name] = struct{}{}
+	return m
+}
+
 func addHostDeviceSupportedProperties(deviceSupported bool, hostSupported bool, bpModule *bpModule) {
 	// If neither device or host is supported then this module does not support either so will not
 	// recognize the properties.
@@ -1230,18 +1232,23 @@ func (s *snapshotBuilder) OptionalSdkMemberReferencePropertyTag() android.BpProp
 // Get a name for sdk snapshot member. If the member is private then generate a snapshot specific
 // name. As part of the processing this checks to make sure that any required members are part of
 // the snapshot.
-func (s *snapshotBuilder) snapshotSdkMemberName(name string, required bool) string {
+func (s *snapshotBuilder) snapshotSdkMemberName(reference string, required bool) string {
+	prefix := ""
+	name := strings.TrimPrefix(reference, ":")
+	if name != reference {
+		prefix = ":"
+	}
 	if _, ok := s.allMembersByName[name]; !ok {
 		if required {
 			s.ctx.ModuleErrorf("Required member reference %s is not a member of the sdk", name)
 		}
-		return name
+		return reference
 	}
 
 	if s.isInternalMember(name) {
-		return s.ctx.ModuleName() + "_" + name
+		return prefix + s.ctx.ModuleName() + "_" + name
 	} else {
-		return name
+		return reference
 	}
 }
 
@@ -2057,6 +2064,7 @@ func (s *sdk) createMemberSnapshot(ctx *memberContext, member *sdkMember, bpModu
 	variantPropertiesFactory := func() android.SdkMemberProperties {
 		properties := memberType.CreateVariantPropertiesStruct()
 		base := properties.Base()
+		base.MemberName = member.Name()
 		base.Os_count = osCount
 		return properties
 	}