Merge "Add CommonOS variant for sdk"

android/arch.go

@@ -607,6 +607,10 @@ var (
 	Android     = NewOsType("android", Device, false)
 	Fuchsia     = NewOsType("fuchsia", Device, false)
 
+	// A pseudo OSType for a common os variant, which is OSType agnostic and which
+	// has dependencies on all the OS variants.
+	CommonOS = NewOsType("common_os", Generic, false)
+
 	osArchTypeMap = map[OsType][]ArchType{
 		Linux:       []ArchType{X86, X86_64},
 		LinuxBionic: []ArchType{X86_64},
@@ -775,12 +779,64 @@ func osMutator(mctx BottomUpMutatorContext) {
 		osNames[i] = os.String()
 	}
 
-	modules := mctx.CreateVariations(osNames...)
+	createCommonOSVariant := base.commonProperties.CreateCommonOSVariant
-	for i, m := range modules {
+	if createCommonOSVariant {
-		m.(Module).base().commonProperties.CompileOS = moduleOSList[i]
+		// A CommonOS variant was requested so add it to the list of OS's variants to
-		m.(Module).base().setOSProperties(mctx)
+		// create. It needs to be added to the end because it needs to depend on the
+		// the other variants in the list returned by CreateVariations(...) and inter
+		// variant dependencies can only be created from a later variant in that list to
+		// an earlier one. That is because variants are always processed in the order in
+		// which they are returned from CreateVariations(...).
+		osNames = append(osNames, CommonOS.Name)
+		moduleOSList = append(moduleOSList, CommonOS)
 	}
 
+	modules := mctx.CreateVariations(osNames...)
+	for i, m := range modules {
+		m.base().commonProperties.CompileOS = moduleOSList[i]
+		m.base().setOSProperties(mctx)
+	}
+
+	if createCommonOSVariant {
+		// A CommonOS variant was requested so add dependencies from it (the last one in
+		// the list) to the OS type specific variants.
+		last := len(modules) - 1
+		commonOSVariant := modules[last]
+		commonOSVariant.base().commonProperties.CommonOSVariant = true
+		for _, module := range modules[0:last] {
+			// Ignore modules that are enabled. Note, this will only avoid adding
+			// dependencies on OsType variants that are explicitly disabled in their
+			// properties. The CommonOS variant will still depend on disabled variants
+			// if they are disabled afterwards, e.g. in archMutator if
+			if module.Enabled() {
+				mctx.AddInterVariantDependency(commonOsToOsSpecificVariantTag, commonOSVariant, module)
+			}
+		}
+	}
+}
+
+// Identifies the dependency from CommonOS variant to the os specific variants.
+type commonOSTag struct{ blueprint.BaseDependencyTag }
+
+var commonOsToOsSpecificVariantTag = commonOSTag{}
+
+// Get the OsType specific variants for the current CommonOS variant.
+//
+// The returned list will only contain enabled OsType specific variants of the
+// module referenced in the supplied context. An empty list is returned if there
+// are no enabled variants or the supplied context is not for an CommonOS
+// variant.
+func GetOsSpecificVariantsOfCommonOSVariant(mctx BaseModuleContext) []Module {
+	var variants []Module
+	mctx.VisitDirectDeps(func(m Module) {
+		if mctx.OtherModuleDependencyTag(m) == commonOsToOsSpecificVariantTag {
+			if m.Enabled() {
+				variants = append(variants, m)
+			}
+		}
+	})
+
+	return variants
 }
 
 // archMutator splits a module into a variant for each Target requested by the module.  Target selection
@@ -821,6 +877,15 @@ func archMutator(mctx BottomUpMutatorContext) {
 	}
 
 	os := base.commonProperties.CompileOS
+	if os == CommonOS {
+		// Make sure that the target related properties are initialized for the
+		// CommonOS variant.
+		addTargetProperties(module, commonTargetMap[os.Name], nil, true)
+
+		// Do not create arch specific variants for the CommonOS variant.
+		return
+	}
+
 	osTargets := mctx.Config().Targets[os]
 	image := base.commonProperties.ImageVariation
 	// Filter NativeBridge targets unless they are explicitly supported
@@ -881,15 +946,17 @@ func archMutator(mctx BottomUpMutatorContext) {
 
 	modules := mctx.CreateVariations(targetNames...)
 	for i, m := range modules {
-		m.(Module).base().commonProperties.CompileTarget = targets[i]
+		addTargetProperties(m, targets[i], multiTargets, i == 0)
-		m.(Module).base().commonProperties.CompileMultiTargets = multiTargets
-		if i == 0 {
-			m.(Module).base().commonProperties.CompilePrimary = true
-		}
 		m.(Module).base().setArchProperties(mctx)
 	}
 }
 
+func addTargetProperties(m Module, target Target, multiTargets []Target, primaryTarget bool) {
+	m.base().commonProperties.CompileTarget = target
+	m.base().commonProperties.CompileMultiTargets = multiTargets
+	m.base().commonProperties.CompilePrimary = primaryTarget
+}
+
 func decodeMultilib(base *ModuleBase, class OsClass) (multilib, extraMultilib string) {
 	switch class {
 	case Device:

android/config.go

@@ -359,6 +359,9 @@ func NewConfig(srcDir, buildDir string) (Config, error) {
 		return Config{}, err
 	}
 
+	// Make the CommonOS OsType available for all products.
+	targets[CommonOS] = []Target{commonTargetMap[CommonOS.Name]}
+
 	var archConfig []archConfig
 	if Bool(config.Mega_device) {
 		archConfig = getMegaDeviceConfig()

android/module.go

@@ -452,6 +452,22 @@ type commonProperties struct {
 	HostOrDeviceSupported HostOrDeviceSupported `blueprint:"mutated"`
 	ArchSpecific          bool                  `blueprint:"mutated"`
 
+	// If set to true then a CommonOS variant will be created which will have dependencies
+	// on all its OsType specific variants. Used by sdk/module_exports to create a snapshot
+	// that covers all os and architecture variants.
+	//
+	// The OsType specific variants can be retrieved by calling
+	// GetOsSpecificVariantsOfCommonOSVariant
+	//
+	// Set at module initialization time by calling InitCommonOSAndroidMultiTargetsArchModule
+	CreateCommonOSVariant bool `blueprint:"mutated"`
+
+	// If set to true then this variant is the CommonOS variant that has dependencies on its
+	// OsType specific variants.
+	//
+	// Set by osMutator.
+	CommonOSVariant bool `blueprint:"mutated"`
+
 	SkipInstall bool `blueprint:"mutated"`
 
 	NamespaceExportedToMake bool `blueprint:"mutated"`
@@ -584,6 +600,14 @@ func InitAndroidMultiTargetsArchModule(m Module, hod HostOrDeviceSupported, defa
 	m.base().commonProperties.UseTargetVariants = false
 }
 
+// As InitAndroidMultiTargetsArchModule except it creates an additional CommonOS variant that
+// has dependencies on all the OsType specific variants.
+func InitCommonOSAndroidMultiTargetsArchModule(m Module, hod HostOrDeviceSupported, defaultMultilib Multilib) {
+	InitAndroidArchModule(m, hod, defaultMultilib)
+	m.base().commonProperties.UseTargetVariants = false
+	m.base().commonProperties.CreateCommonOSVariant = true
+}
+
 // A ModuleBase object contains the properties that are common to all Android
 // modules.  It should be included as an anonymous field in every module
 // struct definition.  InitAndroidModule should then be called from the module's
@@ -775,6 +799,11 @@ func (m *ModuleBase) ArchSpecific() bool {
 	return m.commonProperties.ArchSpecific
 }
 
+// True if the current variant is a CommonOS variant, false otherwise.
+func (m *ModuleBase) IsCommonOSVariant() bool {
+	return m.commonProperties.CommonOSVariant
+}
+
 func (m *ModuleBase) OsClassSupported() []OsClass {
 	switch m.commonProperties.HostOrDeviceSupported {
 	case HostSupported:
@@ -1103,8 +1132,11 @@ func (m *ModuleBase) GenerateBuildActions(blueprintCtx blueprint.ModuleContext)
 	blueprintCtx.GetMissingDependencies()
 
 	// For the final GenerateAndroidBuildActions pass, require that all visited dependencies Soong modules and
-	// are enabled.
+	// are enabled. Unless the module is a CommonOS variant which may have dependencies on disabled variants
-	ctx.baseModuleContext.strictVisitDeps = true
+	// (because the dependencies are added before the modules are disabled). The
+	// GetOsSpecificVariantsOfCommonOSVariant(...) method will ensure that the disabled variants are
+	// ignored.
+	ctx.baseModuleContext.strictVisitDeps = !m.IsCommonOSVariant()
 
 	if ctx.config.captureBuild {
 		ctx.ruleParams = make(map[blueprint.Rule]blueprint.RuleParams)

sdk/cc_sdk_test.go

@@ -17,6 +17,7 @@ package sdk
 import (
 	"testing"
 
+	"android/soong/android"
 	"android/soong/cc"
 )
 
@@ -54,7 +55,7 @@ func TestSdkIsCompileMultilibBoth(t *testing.T) {
 	arm64Output := result.Module("sdkmember", "android_arm64_armv8-a_shared").(*cc.Module).OutputFile()
 
 	var inputs []string
-	buildParams := result.Module("mysdk", "android_common").BuildParamsForTests()
+	buildParams := result.Module("mysdk", android.CommonOS.Name).BuildParamsForTests()
 	for _, bp := range buildParams {
 		if bp.Input != nil {
 			inputs = append(inputs, bp.Input.String())
@@ -250,7 +251,7 @@ func TestSnapshotWithCcDuplicateHeaders(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("mysdk", "android_common", "",
+	result.CheckSnapshot("mysdk", "",
 		checkAllCopyRules(`
 include/Test.h -> include/include/Test.h
 .intermediates/mynativelib1/android_arm64_armv8-a_shared/mynativelib1.so -> arm64/lib/mynativelib1.so
@@ -287,7 +288,7 @@ func TestSnapshotWithCcSharedLibraryCommonProperties(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("mysdk", "android_common", "",
+	result.CheckSnapshot("mysdk", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 
@@ -356,7 +357,7 @@ func TestSnapshotWithCcBinary(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("mymodule_exports", "android_common", "",
+	result.CheckSnapshot("mymodule_exports", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 
@@ -422,7 +423,7 @@ func TestSnapshotWithCcSharedLibrary(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("mysdk", "android_common", "",
+	result.CheckSnapshot("mysdk", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 
@@ -510,7 +511,7 @@ func TestHostSnapshotWithCcSharedLibrary(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("mysdk", "linux_glibc_common", "",
+	result.CheckSnapshot("mysdk", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 
@@ -597,7 +598,7 @@ func TestSnapshotWithCcStaticLibrary(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("myexports", "android_common", "",
+	result.CheckSnapshot("myexports", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 
@@ -685,7 +686,7 @@ func TestHostSnapshotWithCcStaticLibrary(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("myexports", "linux_glibc_common", "",
+	result.CheckSnapshot("myexports", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 
@@ -784,7 +785,7 @@ func TestHostSnapshotWithMultiLib64(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("myexports", "linux_glibc_common", "",
+	result.CheckSnapshot("myexports", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 
@@ -856,7 +857,7 @@ func TestSnapshotWithCcHeadersLibrary(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("mysdk", "android_common", "",
+	result.CheckSnapshot("mysdk", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 
@@ -909,7 +910,7 @@ func TestHostSnapshotWithCcHeadersLibrary(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("mysdk", "linux_glibc_common", "",
+	result.CheckSnapshot("mysdk", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 

sdk/exports_test.go

@@ -42,7 +42,7 @@ func TestModuleExportsSnapshot(t *testing.T) {
 			"package/Android.bp": []byte(packageBp),
 		})
 
-	result.CheckSnapshot("myexports", "android_common", "package",
+	result.CheckSnapshot("myexports", "package",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 

sdk/java_sdk_test.go

@@ -141,7 +141,7 @@ func TestSnapshotWithJavaHeaderLibrary(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("mysdk", "android_common", "",
+	result.CheckSnapshot("mysdk", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 
@@ -196,7 +196,7 @@ func TestHostSnapshotWithJavaHeaderLibrary(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("mysdk", "linux_glibc_common", "",
+	result.CheckSnapshot("mysdk", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 
@@ -250,7 +250,7 @@ func TestSnapshotWithJavaImplLibrary(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("myexports", "android_common", "",
+	result.CheckSnapshot("myexports", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 
@@ -305,7 +305,7 @@ func TestHostSnapshotWithJavaImplLibrary(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("myexports", "linux_glibc_common", "",
+	result.CheckSnapshot("myexports", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 
@@ -356,7 +356,7 @@ func TestSnapshotWithJavaTest(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("myexports", "android_common", "",
+	result.CheckSnapshot("myexports", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 
@@ -409,7 +409,7 @@ func TestHostSnapshotWithJavaTest(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("myexports", "linux_glibc_common", "",
+	result.CheckSnapshot("myexports", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 
@@ -503,7 +503,7 @@ func TestSnapshotWithDroidstubs(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("myexports", "android_common", "",
+	result.CheckSnapshot("myexports", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 
@@ -526,7 +526,7 @@ module_exports_snapshot {
 
 `),
 		checkAllCopyRules(""),
-		checkMergeZip(".intermediates/myexports/android_common/tmp/java/myjavaapistubs_stubs_sources.zip"),
+		checkMergeZip(".intermediates/myexports/common_os/tmp/java/myjavaapistubs_stubs_sources.zip"),
 	)
 }
 
@@ -552,7 +552,7 @@ func TestHostSnapshotWithDroidstubs(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("myexports", "linux_glibc_common", "",
+	result.CheckSnapshot("myexports", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 
@@ -580,7 +580,7 @@ module_exports_snapshot {
 }
 `),
 		checkAllCopyRules(""),
-		checkMergeZip(".intermediates/myexports/linux_glibc_common/tmp/java/myjavaapistubs_stubs_sources.zip"),
+		checkMergeZip(".intermediates/myexports/common_os/tmp/java/myjavaapistubs_stubs_sources.zip"),
 	)
 }
 
@@ -612,7 +612,7 @@ func TestSnapshotWithJavaSystemModules(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("mysdk", "android_common", "",
+	result.CheckSnapshot("mysdk", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 
@@ -702,7 +702,7 @@ func TestHostSnapshotWithJavaSystemModules(t *testing.T) {
 		}
 	`)
 
-	result.CheckSnapshot("mysdk", "linux_glibc_common", "",
+	result.CheckSnapshot("mysdk", "",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 

sdk/sdk.go

@@ -53,6 +53,13 @@ type sdk struct {
 	// The set of exported members.
 	exportedMembers map[string]struct{}
 
+	// Information about the OsType specific member variants associated with this variant.
+	//
+	// Set by OsType specific variants when their GenerateAndroidBuildActions is invoked
+	// and used by the CommonOS variant when its GenerateAndroidBuildActions is invoked, which
+	// is guaranteed to occur afterwards.
+	memberRefs []sdkMemberRef
+
 	properties sdkProperties
 
 	snapshotFile android.OptionalPath
@@ -201,7 +208,7 @@ func newSdkModule(moduleExports bool) *sdk {
 	// properties for the member type specific list properties.
 	s.dynamicMemberTypeListProperties = s.dynamicSdkMemberTypes.createMemberListProperties()
 	s.AddProperties(&s.properties, s.dynamicMemberTypeListProperties)
-	android.InitAndroidMultiTargetsArchModule(s, android.HostAndDeviceSupported, android.MultilibCommon)
+	android.InitCommonOSAndroidMultiTargetsArchModule(s, android.HostAndDeviceSupported, android.MultilibCommon)
 	android.InitDefaultableModule(s)
 	android.AddLoadHook(s, func(ctx android.LoadHookContext) {
 		type props struct {
@@ -252,10 +259,29 @@ func (s *sdk) snapshot() bool {
 }
 
 func (s *sdk) GenerateAndroidBuildActions(ctx android.ModuleContext) {
-	if !s.snapshot() {
+	if s.snapshot() {
 		// We don't need to create a snapshot out of sdk_snapshot.
 		// That doesn't make sense. We need a snapshot to create sdk_snapshot.
-		s.snapshotFile = android.OptionalPathForPath(s.buildSnapshot(ctx))
+		return
+	}
+
+	// This method is guaranteed to be called on OsType specific variants before it is called
+	// on their corresponding CommonOS variant.
+	if !s.IsCommonOSVariant() {
+		// Collect the OsType specific members are add them to the OsType specific variant.
+		s.memberRefs = s.collectMembers(ctx)
+	} else {
+		// Get the OsType specific variants on which the CommonOS depends.
+		osSpecificVariants := android.GetOsSpecificVariantsOfCommonOSVariant(ctx)
+		var sdkVariants []*sdk
+		for _, m := range osSpecificVariants {
+			if sdkVariant, ok := m.(*sdk); ok {
+				sdkVariants = append(sdkVariants, sdkVariant)
+			}
+		}
+
+		// Generate the snapshot from the member info.
+		s.snapshotFile = android.OptionalPathForPath(s.buildSnapshot(ctx, sdkVariants))
 	}
 }
 
@@ -320,7 +346,8 @@ func (t sdkMemberVersionedDepTag) ExcludeFromVisibilityEnforcement() {}
 // Step 1: create dependencies from an SDK module to its members.
 func memberMutator(mctx android.BottomUpMutatorContext) {
 	if s, ok := mctx.Module().(*sdk); ok {
-		if s.Enabled() {
+		// Add dependencies from enabled and non CommonOS variants to the sdk member variants.
+		if s.Enabled() && !s.IsCommonOSVariant() {
 			for _, memberListProperty := range s.memberListProperties() {
 				names := memberListProperty.getter(s.dynamicMemberTypeListProperties)
 				if len(names) > 0 {

sdk/sdk_test.go

@@ -145,7 +145,7 @@ func TestSnapshotVisibility(t *testing.T) {
 			"package/Android.bp": []byte(packageBp),
 		})
 
-	result.CheckSnapshot("mysdk", "android_common", "package",
+	result.CheckSnapshot("mysdk", "package",
 		checkAndroidBpContents(`
 // This is auto-generated. DO NOT EDIT.
 

sdk/testing.go

@@ -246,9 +246,12 @@ func (r *testSdkResult) ModuleForTests(name string, variant string) android.Test
 // Takes a list of functions which check different facets of the snapshot build rules.
 // Allows each test to customize what is checked without duplicating lots of code
 // or proliferating check methods of different flavors.
-func (r *testSdkResult) CheckSnapshot(name string, variant string, dir string, checkers ...snapshotBuildInfoChecker) {
+func (r *testSdkResult) CheckSnapshot(name string, dir string, checkers ...snapshotBuildInfoChecker) {
 	r.t.Helper()
 
+	// The sdk CommonOS variant is always responsible for generating the snapshot.
+	variant := android.CommonOS.Name
+
 	sdk := r.Module(name, variant).(*sdk)
 
 	snapshotBuildInfo := r.getSdkSnapshotBuildInfo(sdk)

sdk/update.go

@@ -104,18 +104,9 @@ func (gf *generatedFile) build(pctx android.PackageContext, ctx android.BuilderC
 
 // Collect all the members.
 //
-// The members are first grouped by type and then grouped by name. The order of
+// Returns a list containing type (extracted from the dependency tag) and the variant.
-// the types is the order they are referenced in android.SdkMemberTypesRegistry.
+func (s *sdk) collectMembers(ctx android.ModuleContext) []sdkMemberRef {
-// The names are in the order in which the dependencies were added.
+	var memberRefs []sdkMemberRef
-//
-// Returns the members as well as the multilib setting to use.
-func (s *sdk) collectMembers(ctx android.ModuleContext) ([]*sdkMember, string) {
-	byType := make(map[android.SdkMemberType][]*sdkMember)
-	byName := make(map[string]*sdkMember)
-
-	lib32 := false // True if any of the members have 32 bit version.
-	lib64 := false // True if any of the members have 64 bit version.
-
 	ctx.WalkDeps(func(child android.Module, parent android.Module) bool {
 		tag := ctx.OtherModuleDependencyTag(child)
 		if memberTag, ok := tag.(android.SdkMemberTypeDependencyTag); ok {
@@ -126,24 +117,7 @@ func (s *sdk) collectMembers(ctx android.ModuleContext) ([]*sdkMember, string) {
 				ctx.ModuleErrorf("module %q is not valid in property %s", ctx.OtherModuleName(child), memberType.SdkPropertyName())
 			}
 
-			name := ctx.OtherModuleName(child)
+			memberRefs = append(memberRefs, sdkMemberRef{memberType, child.(android.SdkAware)})
-			member := byName[name]
-			if member == nil {
-				member = &sdkMember{memberType: memberType, name: name}
-				byName[name] = member
-				byType[memberType] = append(byType[memberType], member)
-			}
-
-			multilib := child.Target().Arch.ArchType.Multilib
-			if multilib == "lib32" {
-				lib32 = true
-			} else if multilib == "lib64" {
-				lib64 = true
-			}
-
-			// Only append new variants to the list. This is needed because a member can be both
-			// exported by the sdk and also be a transitive sdk member.
-			member.variants = appendUniqueVariants(member.variants, child.(android.SdkAware))
 
 			// If the member type supports transitive sdk members then recurse down into
 			// its dependencies, otherwise exit traversal.
@@ -153,6 +127,47 @@ func (s *sdk) collectMembers(ctx android.ModuleContext) ([]*sdkMember, string) {
 		return false
 	})
 
+	return memberRefs
+}
+
+// Organize the members.
+//
+// The members are first grouped by type and then grouped by name. The order of
+// the types is the order they are referenced in android.SdkMemberTypesRegistry.
+// The names are in the order in which the dependencies were added.
+//
+// Returns the members as well as the multilib setting to use.
+func (s *sdk) organizeMembers(ctx android.ModuleContext, memberRefs []sdkMemberRef) ([]*sdkMember, string) {
+	byType := make(map[android.SdkMemberType][]*sdkMember)
+	byName := make(map[string]*sdkMember)
+
+	lib32 := false // True if any of the members have 32 bit version.
+	lib64 := false // True if any of the members have 64 bit version.
+
+	for _, memberRef := range memberRefs {
+		memberType := memberRef.memberType
+		variant := memberRef.variant
+
+		name := ctx.OtherModuleName(variant)
+		member := byName[name]
+		if member == nil {
+			member = &sdkMember{memberType: memberType, name: name}
+			byName[name] = member
+			byType[memberType] = append(byType[memberType], member)
+		}
+
+		multilib := variant.Target().Arch.ArchType.Multilib
+		if multilib == "lib32" {
+			lib32 = true
+		} else if multilib == "lib64" {
+			lib64 = true
+		}
+
+		// Only append new variants to the list. This is needed because a member can be both
+		// exported by the sdk and also be a transitive sdk member.
+		member.variants = appendUniqueVariants(member.variants, variant)
+	}
+
 	var members []*sdkMember
 	for _, memberListProperty := range s.memberListProperties() {
 		membersOfType := byType[memberListProperty.memberType]
@@ -207,7 +222,13 @@ func versionedSdkMemberName(ctx android.ModuleContext, memberName string, versio
 
 // buildSnapshot is the main function in this source file. It creates rules to copy
 // the contents (header files, stub libraries, etc) into the zip file.
-func (s *sdk) buildSnapshot(ctx android.ModuleContext) android.OutputPath {
+func (s *sdk) buildSnapshot(ctx android.ModuleContext, sdkVariants []*sdk) android.OutputPath {
+
+	var memberRefs []sdkMemberRef
+	for _, sdkVariant := range sdkVariants {
+		memberRefs = append(memberRefs, sdkVariant.memberRefs...)
+	}
+
 	snapshotDir := android.PathForModuleOut(ctx, "snapshot")
 
 	bp := newGeneratedFile(ctx, "snapshot", "Android.bp")
@@ -228,7 +249,7 @@ func (s *sdk) buildSnapshot(ctx android.ModuleContext) android.OutputPath {
 	}
 	s.builderForTests = builder
 
-	members, multilib := s.collectMembers(ctx)
+	members, multilib := s.organizeMembers(ctx, memberRefs)
 	for _, member := range members {
 		member.memberType.BuildSnapshot(ctx, builder, member)
 	}
@@ -592,6 +613,11 @@ func (s *snapshotBuilder) unversionedSdkMemberNames(members []string) []string {
 	return references
 }
 
+type sdkMemberRef struct {
+	memberType android.SdkMemberType
+	variant    android.SdkAware
+}
+
 var _ android.SdkMember = (*sdkMember)(nil)
 
 type sdkMember struct {