Merge "Add apexes property to sdk"
diff --git a/android/sdk.go b/android/sdk.go
index 533f2f4..07b94b2 100644
--- a/android/sdk.go
+++ b/android/sdk.go
@@ -677,6 +677,10 @@
 	// SupportedLinkages returns the names of the linkage variants supported by this module.
 	SupportedLinkages() []string
 
+	// ArePrebuiltsRequired returns true if prebuilts are required in the sdk snapshot, false
+	// otherwise.
+	ArePrebuiltsRequired() bool
+
 	// AddDependencies adds dependencies from the SDK module to all the module variants the member
 	// type contributes to the SDK. `names` is the list of module names given in the member type
 	// property (as returned by SdkPropertyName()) in the SDK module. The exact set of variants
@@ -782,7 +786,12 @@
 	// If not specified then it is assumed to be available on all targeted build releases.
 	SupportedBuildReleaseSpecification string
 
-	SupportsSdk     bool
+	// Set to true if this must be usable with the sdk/sdk_snapshot module types. Otherwise, it will
+	// only be usable with module_exports/module_exports_snapshots module types.
+	SupportsSdk bool
+
+	// Set to true if prebuilt host artifacts of this member may be specific to the host OS. Only
+	// applicable to modules where HostSupported() is true.
 	HostOsDependent bool
 
 	// When set to true UseSourceModuleTypeInSnapshot indicates that the member type creates a source
@@ -790,6 +799,11 @@
 	// code from automatically adding a prefer: true flag.
 	UseSourceModuleTypeInSnapshot bool
 
+	// Set to proptools.BoolPtr(false) if this member does not generate prebuilts but is only provided
+	// to allow the sdk to gather members from this member's dependencies. If not specified then
+	// defaults to true.
+	PrebuiltsRequired *bool
+
 	// The list of supported traits.
 	Traits []SdkMemberTrait
 }
@@ -814,6 +828,10 @@
 	return b.HostOsDependent
 }
 
+func (b *SdkMemberTypeBase) ArePrebuiltsRequired() bool {
+	return proptools.BoolDefault(b.PrebuiltsRequired, true)
+}
+
 func (b *SdkMemberTypeBase) UsesSourceModuleTypeInSnapshot() bool {
 	return b.UseSourceModuleTypeInSnapshot
 }
diff --git a/apex/Android.bp b/apex/Android.bp
index fcdf8e6..6533c61 100644
--- a/apex/Android.bp
+++ b/apex/Android.bp
@@ -23,6 +23,7 @@
     srcs: [
         "androidmk.go",
         "apex.go",
+        "apex_sdk_member.go",
         "apex_singleton.go",
         "builder.go",
         "constants.go",
diff --git a/apex/apex.go b/apex/apex.go
index 5678b06..7b6707c 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -606,6 +606,18 @@
 	// replacement. This is needed because some prebuilt modules do not provide all the information
 	// needed by the apex.
 	sourceOnly bool
+
+	// If not-nil and an APEX is a member of an SDK then dependencies of that APEX with this tag will
+	// also be added as exported members of that SDK.
+	memberType android.SdkMemberType
+}
+
+func (d *dependencyTag) SdkMemberType(_ android.Module) android.SdkMemberType {
+	return d.memberType
+}
+
+func (d *dependencyTag) ExportMember() bool {
+	return true
 }
 
 func (d *dependencyTag) String() string {
@@ -617,6 +629,7 @@
 }
 
 var _ android.ReplaceSourceWithPrebuilt = &dependencyTag{}
+var _ android.SdkMemberDependencyTag = &dependencyTag{}
 
 var (
 	androidAppTag   = &dependencyTag{name: "androidApp", payload: true}
@@ -624,8 +637,8 @@
 	certificateTag  = &dependencyTag{name: "certificate"}
 	executableTag   = &dependencyTag{name: "executable", payload: true}
 	fsTag           = &dependencyTag{name: "filesystem", payload: true}
-	bcpfTag         = &dependencyTag{name: "bootclasspathFragment", payload: true, sourceOnly: true}
-	sscpfTag        = &dependencyTag{name: "systemserverclasspathFragment", payload: true, sourceOnly: true}
+	bcpfTag         = &dependencyTag{name: "bootclasspathFragment", payload: true, sourceOnly: true, memberType: java.BootclasspathFragmentSdkMemberType}
+	sscpfTag        = &dependencyTag{name: "systemserverclasspathFragment", payload: true, sourceOnly: true, memberType: java.SystemServerClasspathFragmentSdkMemberType}
 	compatConfigTag = &dependencyTag{name: "compatConfig", payload: true, sourceOnly: true}
 	javaLibTag      = &dependencyTag{name: "javaLib", payload: true}
 	jniLibTag       = &dependencyTag{name: "jniLib", payload: true}
diff --git a/apex/apex_sdk_member.go b/apex/apex_sdk_member.go
new file mode 100644
index 0000000..284158f
--- /dev/null
+++ b/apex/apex_sdk_member.go
@@ -0,0 +1,58 @@
+// Copyright (C) 2022 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"
+	"github.com/google/blueprint"
+	"github.com/google/blueprint/proptools"
+)
+
+// This file contains support for using apex modules within an sdk.
+
+func init() {
+	// Register sdk member types.
+	android.RegisterSdkMemberType(&apexSdkMemberType{
+		SdkMemberTypeBase: android.SdkMemberTypeBase{
+			PropertyName: "apexes",
+			SupportsSdk:  true,
+
+			// The apexes property does not need to be included in the snapshot as adding an apex to an
+			// sdk does not produce any prebuilts of the apex.
+			PrebuiltsRequired: proptools.BoolPtr(false),
+		},
+	})
+}
+
+type apexSdkMemberType struct {
+	android.SdkMemberTypeBase
+}
+
+func (mt *apexSdkMemberType) AddDependencies(ctx android.SdkDependencyContext, dependencyTag blueprint.DependencyTag, names []string) {
+	ctx.AddVariationDependencies(nil, dependencyTag, names...)
+}
+
+func (mt *apexSdkMemberType) IsInstance(module android.Module) bool {
+	_, ok := module.(*apexBundle)
+	return ok
+}
+
+func (mt *apexSdkMemberType) AddPrebuiltModule(ctx android.SdkMemberContext, member android.SdkMember) android.BpModule {
+	panic("Sdk does not create prebuilts of the apexes in its snapshot")
+}
+
+func (mt *apexSdkMemberType) CreateVariantPropertiesStruct() android.SdkMemberProperties {
+	panic("Sdk does not create prebuilts of the apexes in its snapshot")
+}
diff --git a/java/bootclasspath_fragment.go b/java/bootclasspath_fragment.go
index 0591012..f08b64b 100644
--- a/java/bootclasspath_fragment.go
+++ b/java/bootclasspath_fragment.go
@@ -32,12 +32,7 @@
 func init() {
 	registerBootclasspathFragmentBuildComponents(android.InitRegistrationContext)
 
-	android.RegisterSdkMemberType(&bootclasspathFragmentMemberType{
-		SdkMemberTypeBase: android.SdkMemberTypeBase{
-			PropertyName: "bootclasspath_fragments",
-			SupportsSdk:  true,
-		},
-	})
+	android.RegisterSdkMemberType(BootclasspathFragmentSdkMemberType)
 }
 
 func registerBootclasspathFragmentBuildComponents(ctx android.RegistrationContext) {
@@ -46,6 +41,15 @@
 	ctx.RegisterModuleType("prebuilt_bootclasspath_fragment", prebuiltBootclasspathFragmentFactory)
 }
 
+// BootclasspathFragmentSdkMemberType is the member type used to add bootclasspath_fragments to
+// the SDK snapshot. It is exported for use by apex.
+var BootclasspathFragmentSdkMemberType = &bootclasspathFragmentMemberType{
+	SdkMemberTypeBase: android.SdkMemberTypeBase{
+		PropertyName: "bootclasspath_fragments",
+		SupportsSdk:  true,
+	},
+}
+
 type bootclasspathFragmentContentDependencyTag struct {
 	blueprint.BaseDependencyTag
 }
diff --git a/java/systemserver_classpath_fragment.go b/java/systemserver_classpath_fragment.go
index 79d2ee9..a2cd261 100644
--- a/java/systemserver_classpath_fragment.go
+++ b/java/systemserver_classpath_fragment.go
@@ -24,15 +24,7 @@
 func init() {
 	registerSystemserverClasspathBuildComponents(android.InitRegistrationContext)
 
-	android.RegisterSdkMemberType(&systemServerClasspathFragmentMemberType{
-		SdkMemberTypeBase: android.SdkMemberTypeBase{
-			PropertyName: "systemserverclasspath_fragments",
-			SupportsSdk:  true,
-
-			// This was only added in Tiramisu.
-			SupportedBuildReleaseSpecification: "Tiramisu+",
-		},
-	})
+	android.RegisterSdkMemberType(SystemServerClasspathFragmentSdkMemberType)
 }
 
 func registerSystemserverClasspathBuildComponents(ctx android.RegistrationContext) {
@@ -41,6 +33,17 @@
 	ctx.RegisterModuleType("prebuilt_systemserverclasspath_fragment", prebuiltSystemServerClasspathModuleFactory)
 }
 
+var SystemServerClasspathFragmentSdkMemberType = &systemServerClasspathFragmentMemberType{
+	SdkMemberTypeBase: android.SdkMemberTypeBase{
+		PropertyName: "systemserverclasspath_fragments",
+		SupportsSdk:  true,
+
+		// Support for adding systemserverclasspath_fragments to the sdk snapshot was only added in
+		// Tiramisu.
+		SupportedBuildReleaseSpecification: "Tiramisu+",
+	},
+}
+
 type platformSystemServerClasspathModule struct {
 	android.ModuleBase
 
diff --git a/sdk/bootclasspath_fragment_sdk_test.go b/sdk/bootclasspath_fragment_sdk_test.go
index 93ad172..13ddbe7 100644
--- a/sdk/bootclasspath_fragment_sdk_test.go
+++ b/sdk/bootclasspath_fragment_sdk_test.go
@@ -190,7 +190,7 @@
 	android.AssertStringDoesContain(t, "boot jars package check", command, expectedCommandArgs)
 }
 
-func TestSnapshotWithBootClasspathFragment_Contents(t *testing.T) {
+func testSnapshotWithBootClasspathFragment_Contents(t *testing.T, sdk string, copyRules string) {
 	result := android.GroupFixturePreparers(
 		prepareForSdkTestWithJava,
 		java.PrepareForTestWithJavaDefaultModules,
@@ -202,19 +202,7 @@
 		// Add a platform_bootclasspath that depends on the fragment.
 		fixtureAddPlatformBootclasspathForBootclasspathFragment("myapex", "mybootclasspathfragment"),
 
-		android.FixtureWithRootAndroidBp(`
-			sdk {
-				name: "mysdk",
-				bootclasspath_fragments: ["mybootclasspathfragment"],
-				java_sdk_libs: [
-					// This is not strictly needed as it should be automatically added to the sdk_snapshot as
-					// a java_sdk_libs module because it is used in the mybootclasspathfragment's
-					// api.stub_libs property. However, it is specified here to ensure that duplicates are
-					// correctly deduped.
-					"mysdklibrary",
-				],
-			}
-
+		android.FixtureWithRootAndroidBp(sdk+`
 			apex {
 				name: "myapex",
 				key: "myapex.key",
@@ -373,24 +361,7 @@
     },
 }
 		`),
-		checkAllCopyRules(`
-.intermediates/mybootclasspathfragment/android_common/modular-hiddenapi/annotation-flags.csv -> hiddenapi/annotation-flags.csv
-.intermediates/mybootclasspathfragment/android_common/modular-hiddenapi/metadata.csv -> hiddenapi/metadata.csv
-.intermediates/mybootclasspathfragment/android_common/modular-hiddenapi/index.csv -> hiddenapi/index.csv
-.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
-.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
-.intermediates/mysdklibrary.stubs/android_common/javac/mysdklibrary.stubs.jar -> sdk_library/public/mysdklibrary-stubs.jar
-.intermediates/mysdklibrary.stubs.source/android_common/metalava/mysdklibrary.stubs.source_api.txt -> sdk_library/public/mysdklibrary.txt
-.intermediates/mysdklibrary.stubs.source/android_common/metalava/mysdklibrary.stubs.source_removed.txt -> sdk_library/public/mysdklibrary-removed.txt
-.intermediates/mycoreplatform.stubs/android_common/javac/mycoreplatform.stubs.jar -> sdk_library/public/mycoreplatform-stubs.jar
-.intermediates/mycoreplatform.stubs.source/android_common/metalava/mycoreplatform.stubs.source_api.txt -> sdk_library/public/mycoreplatform.txt
-.intermediates/mycoreplatform.stubs.source/android_common/metalava/mycoreplatform.stubs.source_removed.txt -> sdk_library/public/mycoreplatform-removed.txt
-`),
+		checkAllCopyRules(copyRules),
 		snapshotTestPreparer(checkSnapshotWithoutSource, preparerForSnapshot),
 		snapshotTestChecker(checkSnapshotWithoutSource, func(t *testing.T, result *android.TestResult) {
 			module := result.ModuleForTests("platform-bootclasspath", "android_common")
@@ -427,6 +398,89 @@
 	)
 }
 
+func TestSnapshotWithBootClasspathFragment_Contents(t *testing.T) {
+	t.Run("added-directly", func(t *testing.T) {
+		testSnapshotWithBootClasspathFragment_Contents(t, `
+			sdk {
+				name: "mysdk",
+				bootclasspath_fragments: ["mybootclasspathfragment"],
+				java_sdk_libs: [
+					// This is not strictly needed as it should be automatically added to the sdk_snapshot as
+					// a java_sdk_libs module because it is used in the mybootclasspathfragment's
+					// api.stub_libs property. However, it is specified here to ensure that duplicates are
+					// correctly deduped.
+					"mysdklibrary",
+				],
+			}
+		`, `
+.intermediates/mybootclasspathfragment/android_common/modular-hiddenapi/annotation-flags.csv -> hiddenapi/annotation-flags.csv
+.intermediates/mybootclasspathfragment/android_common/modular-hiddenapi/metadata.csv -> hiddenapi/metadata.csv
+.intermediates/mybootclasspathfragment/android_common/modular-hiddenapi/index.csv -> hiddenapi/index.csv
+.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
+.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
+.intermediates/mysdklibrary.stubs/android_common/javac/mysdklibrary.stubs.jar -> sdk_library/public/mysdklibrary-stubs.jar
+.intermediates/mysdklibrary.stubs.source/android_common/metalava/mysdklibrary.stubs.source_api.txt -> sdk_library/public/mysdklibrary.txt
+.intermediates/mysdklibrary.stubs.source/android_common/metalava/mysdklibrary.stubs.source_removed.txt -> sdk_library/public/mysdklibrary-removed.txt
+.intermediates/mycoreplatform.stubs/android_common/javac/mycoreplatform.stubs.jar -> sdk_library/public/mycoreplatform-stubs.jar
+.intermediates/mycoreplatform.stubs.source/android_common/metalava/mycoreplatform.stubs.source_api.txt -> sdk_library/public/mycoreplatform.txt
+.intermediates/mycoreplatform.stubs.source/android_common/metalava/mycoreplatform.stubs.source_removed.txt -> sdk_library/public/mycoreplatform-removed.txt
+`)
+	})
+
+	copyBootclasspathFragmentFromApexVariantRules := `
+.intermediates/mybootclasspathfragment/android_common_myapex/modular-hiddenapi/annotation-flags.csv -> hiddenapi/annotation-flags.csv
+.intermediates/mybootclasspathfragment/android_common_myapex/modular-hiddenapi/metadata.csv -> hiddenapi/metadata.csv
+.intermediates/mybootclasspathfragment/android_common_myapex/modular-hiddenapi/index.csv -> hiddenapi/index.csv
+.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
+.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
+.intermediates/mysdklibrary.stubs/android_common/javac/mysdklibrary.stubs.jar -> sdk_library/public/mysdklibrary-stubs.jar
+.intermediates/mysdklibrary.stubs.source/android_common/metalava/mysdklibrary.stubs.source_api.txt -> sdk_library/public/mysdklibrary.txt
+.intermediates/mysdklibrary.stubs.source/android_common/metalava/mysdklibrary.stubs.source_removed.txt -> sdk_library/public/mysdklibrary-removed.txt
+.intermediates/mycoreplatform.stubs/android_common/javac/mycoreplatform.stubs.jar -> sdk_library/public/mycoreplatform-stubs.jar
+.intermediates/mycoreplatform.stubs.source/android_common/metalava/mycoreplatform.stubs.source_api.txt -> sdk_library/public/mycoreplatform.txt
+.intermediates/mycoreplatform.stubs.source/android_common/metalava/mycoreplatform.stubs.source_removed.txt -> sdk_library/public/mycoreplatform-removed.txt
+`
+	t.Run("added-via-apex", func(t *testing.T) {
+		testSnapshotWithBootClasspathFragment_Contents(t, `
+			sdk {
+				name: "mysdk",
+				apexes: ["myapex"],
+			}
+		`, copyBootclasspathFragmentFromApexVariantRules)
+	})
+
+	t.Run("added-directly-and-indirectly", func(t *testing.T) {
+		testSnapshotWithBootClasspathFragment_Contents(t, `
+			sdk {
+				name: "mysdk",
+				apexes: ["myapex"],
+				// This is not strictly needed as it should be automatically added to the sdk_snapshot as
+				// a bootclasspath_fragments module because it is used in the myapex's
+				// bootclasspath_fragments property. However, it is specified here to ensure that duplicates
+				// are correctly deduped.
+				bootclasspath_fragments: ["mybootclasspathfragment"],
+				java_sdk_libs: [
+					// This is not strictly needed as it should be automatically added to the sdk_snapshot as
+					// a java_sdk_libs module because it is used in the mybootclasspathfragment's
+					// api.stub_libs property. However, it is specified here to ensure that duplicates are
+					// correctly deduped.
+					"mysdklibrary",
+				],
+			}
+		`, copyBootclasspathFragmentFromApexVariantRules)
+	})
+}
+
 // TestSnapshotWithBootClasspathFragment_Fragments makes sure that the fragments property of a
 // bootclasspath_fragment is correctly output to the sdk snapshot.
 func TestSnapshotWithBootClasspathFragment_Fragments(t *testing.T) {
diff --git a/sdk/systemserverclasspath_fragment_sdk_test.go b/sdk/systemserverclasspath_fragment_sdk_test.go
index 1c84a7b..1ac405d 100644
--- a/sdk/systemserverclasspath_fragment_sdk_test.go
+++ b/sdk/systemserverclasspath_fragment_sdk_test.go
@@ -22,7 +22,7 @@
 	"android/soong/java"
 )
 
-func testSnapshotWithSystemServerClasspathFragment(t *testing.T, targetBuildRelease string, expectedSdkSnapshot string) {
+func testSnapshotWithSystemServerClasspathFragment(t *testing.T, sdk string, targetBuildRelease string, expectedSdkSnapshot string) {
 	result := android.GroupFixturePreparers(
 		prepareForSdkTestWithJava,
 		java.PrepareForTestWithJavaDefaultModules,
@@ -30,23 +30,13 @@
 		java.FixtureWithLastReleaseApis("mysdklibrary"),
 		dexpreopt.FixtureSetApexSystemServerJars("myapex:mylib", "myapex:mysdklibrary"),
 		android.FixtureModifyEnv(func(env map[string]string) {
-			env["SOONG_SDK_SNAPSHOT_TARGET_BUILD_RELEASE"] = targetBuildRelease
+			if targetBuildRelease != "latest" {
+				env["SOONG_SDK_SNAPSHOT_TARGET_BUILD_RELEASE"] = targetBuildRelease
+			}
 		}),
 		prepareForSdkTestWithApex,
 
-		android.FixtureWithRootAndroidBp(`
-			sdk {
-				name: "mysdk",
-				systemserverclasspath_fragments: ["mysystemserverclasspathfragment"],
-				java_sdk_libs: [
-					// This is not strictly needed as it should be automatically added to the sdk_snapshot as
-					// a java_sdk_libs module because it is used in the mysystemserverclasspathfragment's
-					// contents property. However, it is specified here to ensure that duplicates are
-					// correctly deduped.
-					"mysdklibrary",
-				],
-			}
-
+		android.FixtureWithRootAndroidBp(sdk+`
 			apex {
 				name: "myapex",
 				key: "myapex.key",
@@ -91,8 +81,62 @@
 }
 
 func TestSnapshotWithSystemServerClasspathFragment(t *testing.T) {
+
+	commonSdk := `
+sdk {
+	name: "mysdk",
+	systemserverclasspath_fragments: ["mysystemserverclasspathfragment"],
+	java_sdk_libs: [
+		// This is not strictly needed as it should be automatically added to the sdk_snapshot as
+		// a java_sdk_libs module because it is used in the mysystemserverclasspathfragment's
+		// contents property. However, it is specified here to ensure that duplicates are
+		// correctly deduped.
+		"mysdklibrary",
+	],
+}
+	`
+
+	expectedLatestSnapshot := `
+// This is auto-generated. DO NOT EDIT.
+
+java_sdk_library_import {
+    name: "mysdklibrary",
+    prefer: false,
+    visibility: ["//visibility:public"],
+    apex_available: ["myapex"],
+    shared_library: false,
+    public: {
+        jars: ["sdk_library/public/mysdklibrary-stubs.jar"],
+        stub_srcs: ["sdk_library/public/mysdklibrary_stub_sources"],
+        current_api: "sdk_library/public/mysdklibrary.txt",
+        removed_api: "sdk_library/public/mysdklibrary-removed.txt",
+        sdk_version: "current",
+    },
+}
+
+java_import {
+    name: "mylib",
+    prefer: false,
+    visibility: ["//visibility:public"],
+    apex_available: ["myapex"],
+    jars: ["java_systemserver_libs/snapshot/jars/are/invalid/mylib.jar"],
+    permitted_packages: ["mylib"],
+}
+
+prebuilt_systemserverclasspath_fragment {
+    name: "mysystemserverclasspathfragment",
+    prefer: false,
+    visibility: ["//visibility:public"],
+    apex_available: ["myapex"],
+    contents: [
+        "mylib",
+        "mysdklibrary",
+    ],
+}
+`
+
 	t.Run("target-s", func(t *testing.T) {
-		testSnapshotWithSystemServerClasspathFragment(t, "S", `
+		testSnapshotWithSystemServerClasspathFragment(t, commonSdk, "S", `
 // This is auto-generated. DO NOT EDIT.
 
 java_sdk_library_import {
@@ -113,7 +157,7 @@
 	})
 
 	t.Run("target-t", func(t *testing.T) {
-		testSnapshotWithSystemServerClasspathFragment(t, "Tiramisu", `
+		testSnapshotWithSystemServerClasspathFragment(t, commonSdk, "Tiramisu", `
 // This is auto-generated. DO NOT EDIT.
 
 java_sdk_library_import {
@@ -152,4 +196,17 @@
 }
 `)
 	})
+
+	t.Run("added-directly", func(t *testing.T) {
+		testSnapshotWithSystemServerClasspathFragment(t, commonSdk, `latest`, expectedLatestSnapshot)
+	})
+
+	t.Run("added-via-apex", func(t *testing.T) {
+		testSnapshotWithSystemServerClasspathFragment(t, `
+			sdk {
+				name: "mysdk",
+				apexes: ["myapex"],
+			}
+		`, `latest`, expectedLatestSnapshot)
+	})
 }
diff --git a/sdk/update.go b/sdk/update.go
index 8e4f9d4..b9ef3d0 100644
--- a/sdk/update.go
+++ b/sdk/update.go
@@ -433,6 +433,9 @@
 	traits := s.gatherTraits()
 	for _, member := range members {
 		memberType := member.memberType
+		if !memberType.ArePrebuiltsRequired() {
+			continue
+		}
 
 		name := member.name
 		requiredTraits := traits[name]
@@ -1319,6 +1322,119 @@
 	}
 }
 
+// TODO(187910671): BEGIN - Remove once modules do not have an APEX and default variant.
+// variantCoordinate contains the coordinates used to identify a variant of an SDK member.
+type variantCoordinate struct {
+	// osType identifies the OS target of a variant.
+	osType android.OsType
+	// archId identifies the architecture and whether it is for the native bridge.
+	archId archId
+	// image is the image variant name.
+	image string
+	// linkType is the link type name.
+	linkType string
+}
+
+func getVariantCoordinate(ctx *memberContext, variant android.Module) variantCoordinate {
+	linkType := ""
+	if len(ctx.MemberType().SupportedLinkages()) > 0 {
+		linkType = getLinkType(variant)
+	}
+	return variantCoordinate{
+		osType:   variant.Target().Os,
+		archId:   archIdFromTarget(variant.Target()),
+		image:    variant.ImageVariation().Variation,
+		linkType: linkType,
+	}
+}
+
+// selectApexVariantsWhereAvailable filters the input list of variants by selecting the APEX
+// specific variant for a specific variantCoordinate when there is both an APEX and default variant.
+//
+// There is a long-standing issue where a module that is added to an APEX has both an APEX and
+// default/platform variant created even when the module does not require a platform variant. As a
+// result an indirect dependency onto a module via the APEX will use the APEX variant, whereas a
+// direct dependency onto the module will use the default/platform variant. That would result in a
+// failure while attempting to optimize the properties for a member as it would have two variants
+// when only one was expected.
+//
+// This function mitigates that problem by detecting when there are two variants that differ only
+// by apex variant, where one is the default/platform variant and one is the APEX variant. In that
+// case it picks the APEX variant. It picks the APEX variant because that is the behavior that would
+// be expected
+func selectApexVariantsWhereAvailable(ctx *memberContext, variants []android.SdkAware) []android.SdkAware {
+	moduleCtx := ctx.sdkMemberContext
+
+	// Group the variants by coordinates.
+	variantsByCoord := make(map[variantCoordinate][]android.SdkAware)
+	for _, variant := range variants {
+		coord := getVariantCoordinate(ctx, variant)
+		variantsByCoord[coord] = append(variantsByCoord[coord], variant)
+	}
+
+	toDiscard := make(map[android.SdkAware]struct{})
+	for coord, list := range variantsByCoord {
+		count := len(list)
+		if count == 1 {
+			continue
+		}
+
+		variantsByApex := make(map[string]android.SdkAware)
+		conflictDetected := false
+		for _, variant := range list {
+			apexInfo := moduleCtx.OtherModuleProvider(variant, android.ApexInfoProvider).(android.ApexInfo)
+			apexVariationName := apexInfo.ApexVariationName
+			// If there are two variants for a specific APEX variation then there is conflict.
+			if _, ok := variantsByApex[apexVariationName]; ok {
+				conflictDetected = true
+				break
+			}
+			variantsByApex[apexVariationName] = variant
+		}
+
+		// If there are more than 2 apex variations or one of the apex variations is not the
+		// default/platform variation then there is a conflict.
+		if len(variantsByApex) != 2 {
+			conflictDetected = true
+		} else if _, ok := variantsByApex[""]; !ok {
+			conflictDetected = true
+		}
+
+		// If there are no conflicts then add the default/platform variation to the list to remove.
+		if !conflictDetected {
+			toDiscard[variantsByApex[""]] = struct{}{}
+			continue
+		}
+
+		// There are duplicate variants at this coordinate and they are not the default and APEX variant
+		// so fail.
+		variantDescriptions := []string{}
+		for _, m := range list {
+			variantDescriptions = append(variantDescriptions, fmt.Sprintf("    %s", m.String()))
+		}
+
+		moduleCtx.ModuleErrorf("multiple conflicting variants detected for OsType{%s}, %s, Image{%s}, Link{%s}\n%s",
+			coord.osType, coord.archId.String(), coord.image, coord.linkType,
+			strings.Join(variantDescriptions, "\n"))
+	}
+
+	// If there are any variants to discard then remove them from the list of variants, while
+	// preserving the order.
+	if len(toDiscard) > 0 {
+		filtered := []android.SdkAware{}
+		for _, variant := range variants {
+			if _, ok := toDiscard[variant]; !ok {
+				filtered = append(filtered, variant)
+			}
+		}
+		variants = filtered
+	}
+
+	return variants
+}
+
+// TODO(187910671): END - Remove once modules do not have an APEX and default variant.
+
 type baseInfo struct {
 	Properties android.SdkMemberProperties
 }
@@ -1374,7 +1490,14 @@
 
 	if commonVariants, ok := variantsByArchId[commonArchId]; ok {
 		if len(osTypeVariants) != 1 {
-			panic(fmt.Errorf("Expected to only have 1 variant when arch type is common but found %d", len(osTypeVariants)))
+			variants := []string{}
+			for _, m := range osTypeVariants {
+				variants = append(variants, fmt.Sprintf("    %s", m.String()))
+			}
+			panic(fmt.Errorf("expected to only have 1 variant of %q when arch type is common but found %d\n%s",
+				ctx.Name(),
+				len(osTypeVariants),
+				strings.Join(variants, "\n")))
 		}
 
 		// A common arch type only has one variant and its properties should be treated
@@ -1854,7 +1977,8 @@
 	memberType := member.memberType
 
 	// Do not add the prefer property if the member snapshot module is a source module type.
-	config := ctx.sdkMemberContext.Config()
+	moduleCtx := ctx.sdkMemberContext
+	config := moduleCtx.Config()
 	if !memberType.UsesSourceModuleTypeInSnapshot() {
 		// Set the prefer based on the environment variable. This is a temporary work around to allow a
 		// snapshot to be created that sets prefer: true.
@@ -1879,9 +2003,10 @@
 		}
 	}
 
+	variants := selectApexVariantsWhereAvailable(ctx, member.variants)
+
 	// Group the variants by os type.
 	variantsByOsType := make(map[android.OsType][]android.Module)
-	variants := member.Variants()
 	for _, variant := range variants {
 		osType := variant.Target().Os
 		variantsByOsType[osType] = append(variantsByOsType[osType], variant)
@@ -1927,7 +2052,7 @@
 	}
 
 	// Extract properties which are common across all architectures and os types.
-	extractCommonProperties(ctx.sdkMemberContext, commonValueExtractor, commonProperties, osSpecificPropertiesContainers)
+	extractCommonProperties(moduleCtx, commonValueExtractor, commonProperties, osSpecificPropertiesContainers)
 
 	// Add the common properties to the module.
 	addSdkMemberPropertiesToSet(ctx, commonProperties, bpModule)