Merge "soong: move -Wimplicit-fallthrough from cflags to cxxflags"
diff --git a/android/config.go b/android/config.go
index 63994e6..1e5a24d 100644
--- a/android/config.go
+++ b/android/config.go
@@ -1087,6 +1087,10 @@
 	return c.productVariables.EnforceSystemCertificateWhitelist
 }
 
+func (c *config) EnforceProductPartitionInterface() bool {
+	return Bool(c.productVariables.EnforceProductPartitionInterface)
+}
+
 func (c *config) ProductHiddenAPIStubs() []string {
 	return c.productVariables.ProductHiddenAPIStubs
 }
diff --git a/android/variable.go b/android/variable.go
index abbdf21..25a5dc0 100644
--- a/android/variable.go
+++ b/android/variable.go
@@ -309,6 +309,8 @@
 	TargetFSConfigGen []string `json:",omitempty"`
 
 	MissingUsesLibraries []string `json:",omitempty"`
+
+	EnforceProductPartitionInterface *bool `json:",omitempty"`
 }
 
 func boolPtr(v bool) *bool {
diff --git a/apex/apex.go b/apex/apex.go
index d77670a..f03a8f9 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -652,6 +652,7 @@
 
 	testApex        bool
 	vndkApex        bool
+	artApex         bool
 	primaryApexType bool
 
 	// intermediate path for apex_manifest.json
@@ -1216,7 +1217,7 @@
 			if am, ok := child.(android.ApexModule); ok {
 				// We cannot use a switch statement on `depTag` here as the checked
 				// tags used below are private (e.g. `cc.sharedDepTag`).
-				if cc.IsSharedDepTag(depTag) || cc.IsRuntimeDepTag(depTag) {
+				if cc.IsSharedDepTag(depTag) || cc.IsRuntimeDepTag(depTag) || java.IsJniDepTag(depTag) {
 					if cc, ok := child.(*cc.Module); ok {
 						if android.InList(cc.Name(), providedNativeSharedLibs) {
 							// If we're using a shared library which is provided from other APEX,
@@ -1261,6 +1262,19 @@
 		return false
 	})
 
+	// Specific to the ART apex: dexpreopt artifacts for libcore Java libraries.
+	// Build rules are generated by the dexpreopt singleton, and here we access build artifacts
+	// via the global boot image config.
+	if a.artApex {
+		for arch, files := range java.DexpreoptedArtApexJars(ctx) {
+			dirInApex := filepath.Join("javalib", arch.String())
+			for _, f := range files {
+				localModule := "javalib_" + arch.String() + "_" + filepath.Base(f.String())
+				filesInfo = append(filesInfo, apexFile{f, localModule, dirInApex, etc, nil, nil})
+			}
+		}
+	}
+
 	if a.private_key_file == nil {
 		ctx.PropertyErrorf("key", "private_key for %q could not be found", String(a.properties.Key))
 		return
@@ -1875,9 +1889,10 @@
 	return module
 }
 
-func ApexBundleFactory(testApex bool) android.Module {
+func ApexBundleFactory(testApex bool, artApex bool) android.Module {
 	bundle := newApexBundle()
 	bundle.testApex = testApex
+	bundle.artApex = artApex
 	return bundle
 }
 
diff --git a/apex/apex_test.go b/apex/apex_test.go
index ac5c6fc..614164d 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -2513,6 +2513,7 @@
 			srcs: ["foo/bar/MyClass.java"],
 			sdk_version: "none",
 			system_modules: "none",
+			jni_libs: ["libjni"],
 		}
 
 		android_app {
@@ -2522,6 +2523,13 @@
 			system_modules: "none",
 			privileged: true,
 		}
+
+		cc_library_shared {
+			name: "libjni",
+			srcs: ["mylib.cpp"],
+			stl: "none",
+			system_shared_libs: [],
+		}
 	`)
 
 	module := ctx.ModuleForTests("myapex", "android_common_myapex_image")
@@ -2530,6 +2538,7 @@
 
 	ensureContains(t, copyCmds, "image.apex/app/AppFoo/AppFoo.apk")
 	ensureContains(t, copyCmds, "image.apex/priv-app/AppFooPriv/AppFooPriv.apk")
+	ensureContains(t, copyCmds, "image.apex/lib64/libjni.so")
 }
 
 func TestApexWithAppImports(t *testing.T) {
diff --git a/cc/androidmk.go b/cc/androidmk.go
index 91a3c99..ff181d8 100644
--- a/cc/androidmk.go
+++ b/cc/androidmk.go
@@ -327,14 +327,15 @@
 			filepath.Dir(fuzz.config.String())+":config.json")
 	}
 
-	if len(fuzzFiles) > 0 {
-		ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
-			fmt.Fprintln(w, "LOCAL_TEST_DATA := "+strings.Join(fuzzFiles, " "))
-		})
-	}
-
 	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
 		fmt.Fprintln(w, "LOCAL_IS_FUZZ_TARGET := true")
+		if len(fuzzFiles) > 0 {
+			fmt.Fprintln(w, "LOCAL_TEST_DATA := "+strings.Join(fuzzFiles, " "))
+		}
+		if fuzz.installedSharedDeps != nil {
+			fmt.Fprintln(w, "LOCAL_FUZZ_INSTALLED_SHARED_DEPS :="+
+				strings.Join(fuzz.installedSharedDeps, " "))
+		}
 	})
 }
 
diff --git a/cc/config/clang.go b/cc/config/clang.go
index b42074b..030a076 100644
--- a/cc/config/clang.go
+++ b/cc/config/clang.go
@@ -139,9 +139,7 @@
 		"-Wimplicit-fallthrough",
 
 		// Enable clang's thread-safety annotations in libcxx.
-		// Turn off -Wthread-safety-negative, to avoid breaking projects that use -Weverything.
 		"-D_LIBCPP_ENABLE_THREAD_SAFETY_ANNOTATIONS",
-		"-Wno-thread-safety-negative",
 
 		// libc++'s math.h has an #include_next outside of system_headers.
 		"-Wno-gnu-include-next",
diff --git a/cc/fuzz.go b/cc/fuzz.go
index 577fa70..1f06fb0 100644
--- a/cc/fuzz.go
+++ b/cc/fuzz.go
@@ -17,10 +17,9 @@
 import (
 	"encoding/json"
 	"path/filepath"
+	"sort"
 	"strings"
 
-	"github.com/google/blueprint/proptools"
-
 	"android/soong/android"
 	"android/soong/cc/config"
 )
@@ -82,6 +81,7 @@
 	corpus                android.Paths
 	corpusIntermediateDir android.Path
 	config                android.Path
+	installedSharedDeps   []string
 }
 
 func (fuzz *fuzzBinary) linkerProps() []interface{} {
@@ -91,21 +91,6 @@
 }
 
 func (fuzz *fuzzBinary) linkerInit(ctx BaseModuleContext) {
-	// Add ../lib[64] to rpath so that out/host/linux-x86/fuzz/<fuzzer> can
-	// find out/host/linux-x86/lib[64]/library.so
-	runpaths := []string{"../lib"}
-	for _, runpath := range runpaths {
-		if ctx.toolchain().Is64Bit() {
-			runpath += "64"
-		}
-		fuzz.binaryDecorator.baseLinker.dynamicProperties.RunPaths = append(
-			fuzz.binaryDecorator.baseLinker.dynamicProperties.RunPaths, runpath)
-	}
-
-	// add "" to rpath so that fuzzer binaries can find libraries in their own fuzz directory
-	fuzz.binaryDecorator.baseLinker.dynamicProperties.RunPaths = append(
-		fuzz.binaryDecorator.baseLinker.dynamicProperties.RunPaths, "")
-
 	fuzz.binaryDecorator.linkerInit(ctx)
 }
 
@@ -118,9 +103,80 @@
 
 func (fuzz *fuzzBinary) linkerFlags(ctx ModuleContext, flags Flags) Flags {
 	flags = fuzz.binaryDecorator.linkerFlags(ctx, flags)
+	// RunPaths on devices isn't instantiated by the base linker.
+	flags.Local.LdFlags = append(flags.Local.LdFlags, `-Wl,-rpath,\$$ORIGIN/../lib`)
 	return flags
 }
 
+// This function performs a breadth-first search over the provided module's
+// dependencies using `visitDirectDeps` to enumerate all shared library
+// dependencies. We require breadth-first expansion, as otherwise we may
+// incorrectly use the core libraries (sanitizer runtimes, libc, libdl, etc.)
+// from a dependency. This may cause issues when dependencies have explicit
+// sanitizer tags, as we may get a dependency on an unsanitized libc, etc.
+func collectAllSharedDependencies(
+	module android.Module,
+	sharedDeps map[string]android.Path,
+	ctx android.SingletonContext) {
+	var fringe []android.Module
+
+	// Enumerate the first level of dependencies, as we discard all non-library
+	// modules in the BFS loop below.
+	ctx.VisitDirectDeps(module, func(dep android.Module) {
+		fringe = append(fringe, dep)
+	})
+
+	for i := 0; i < len(fringe); i++ {
+		module := fringe[i]
+		if !isValidSharedDependency(module, sharedDeps) {
+			continue
+		}
+
+		ccModule := module.(*Module)
+		sharedDeps[ccModule.Name()] = ccModule.UnstrippedOutputFile()
+		ctx.VisitDirectDeps(module, func(dep android.Module) {
+			fringe = append(fringe, dep)
+		})
+	}
+}
+
+// This function takes a module and determines if it is a unique shared library
+// that should be installed in the fuzz target output directories. This function
+// returns true, unless:
+//  - The module already exists in `sharedDeps`, or
+//  - The module is not a shared library, or
+//  - The module is a header, stub, or vendor-linked library.
+func isValidSharedDependency(
+	dependency android.Module,
+	sharedDeps map[string]android.Path) bool {
+	// TODO(b/144090547): We should be parsing these modules using
+	// ModuleDependencyTag instead of the current brute-force checking.
+
+	if linkable, ok := dependency.(LinkableInterface); !ok || // Discard non-linkables.
+		!linkable.CcLibraryInterface() || !linkable.Shared() || // Discard static libs.
+		linkable.UseVndk() || // Discard vendor linked libraries.
+		!linkable.CcLibrary() || linkable.BuildStubs() { // Discard stubs libs (only CCLibrary variants).
+		return false
+	}
+
+	// If this library has already been traversed, we don't need to do any more work.
+	if _, exists := sharedDeps[dependency.Name()]; exists {
+		return false
+	}
+	return true
+}
+
+func sharedLibraryInstallLocation(
+	libraryPath android.Path, isHost bool, archString string) string {
+	installLocation := "$(PRODUCT_OUT)/data"
+	if isHost {
+		installLocation = "$(HOST_OUT)"
+	}
+	installLocation = filepath.Join(
+		installLocation, "fuzz", archString, "lib", libraryPath.Base())
+	return installLocation
+}
+
 func (fuzz *fuzzBinary) install(ctx ModuleContext, file android.Path) {
 	fuzz.binaryDecorator.baseInstaller.dir = filepath.Join(
 		"fuzz", ctx.Target().Arch.ArchType.String(), ctx.ModuleName())
@@ -160,6 +216,22 @@
 		})
 		fuzz.config = configPath
 	}
+
+	// Grab the list of required shared libraries.
+	sharedLibraries := make(map[string]android.Path)
+	ctx.WalkDeps(func(child, parent android.Module) bool {
+		if isValidSharedDependency(child, sharedLibraries) {
+			sharedLibraries[child.Name()] = child.(*Module).UnstrippedOutputFile()
+			return true
+		}
+		return false
+	})
+
+	for _, lib := range sharedLibraries {
+		fuzz.installedSharedDeps = append(fuzz.installedSharedDeps,
+			sharedLibraryInstallLocation(
+				lib, ctx.Host(), ctx.Arch().ArchType.String()))
+	}
 }
 
 func NewFuzz(hod android.HostOrDeviceSupported) *Module {
@@ -193,28 +265,15 @@
 		ctx.AppendProperties(&disableDarwinAndLinuxBionic)
 	})
 
-	// Statically link the STL. This allows fuzz target deployment to not have to
-	// include the STL.
-	android.AddLoadHook(module, func(ctx android.LoadHookContext) {
-		staticStlLinkage := struct {
-			Target struct {
-				Linux_glibc struct {
-					Stl *string
-				}
-			}
-		}{}
-
-		staticStlLinkage.Target.Linux_glibc.Stl = proptools.StringPtr("libc++_static")
-		ctx.AppendProperties(&staticStlLinkage)
-	})
-
 	return module
 }
 
 // Responsible for generating GNU Make rules that package fuzz targets into
 // their architecture & target/host specific zip file.
 type fuzzPackager struct {
-	packages android.Paths
+	packages                android.Paths
+	sharedLibInstallStrings []string
+	fuzzTargets             map[string]bool
 }
 
 func fuzzPackagingFactory() android.Singleton {
@@ -226,18 +285,31 @@
 	DestinationPathPrefix string
 }
 
+type archAndLibraryKey struct {
+	ArchDir android.OutputPath
+	Library android.Path
+}
+
 func (s *fuzzPackager) GenerateBuildActions(ctx android.SingletonContext) {
 	// Map between each architecture + host/device combination, and the files that
 	// need to be packaged (in the tuple of {source file, destination folder in
 	// archive}).
 	archDirs := make(map[android.OutputPath][]fileToZip)
 
+	// List of shared library dependencies for each architecture + host/device combo.
+	archSharedLibraryDeps := make(map[archAndLibraryKey]bool)
+
+	// List of individual fuzz targets, so that 'make fuzz' also installs the targets
+	// to the correct output directories as well.
+	s.fuzzTargets = make(map[string]bool)
+
 	ctx.VisitAllModules(func(module android.Module) {
 		// Discard non-fuzz targets.
 		ccModule, ok := module.(*Module)
 		if !ok {
 			return
 		}
+
 		fuzzModule, ok := ccModule.compiler.(*fuzzBinary)
 		if !ok {
 			return
@@ -249,6 +321,8 @@
 			return
 		}
 
+		s.fuzzTargets[module.Name()] = true
+
 		hostOrTargetString := "target"
 		if ccModule.Host() {
 			hostOrTargetString = "host"
@@ -257,6 +331,29 @@
 		archString := ccModule.Arch().ArchType.String()
 		archDir := android.PathForIntermediates(ctx, "fuzz", hostOrTargetString, archString)
 
+		// Grab the list of required shared libraries.
+		sharedLibraries := make(map[string]android.Path)
+		collectAllSharedDependencies(module, sharedLibraries, ctx)
+
+		for _, library := range sharedLibraries {
+			if _, exists := archSharedLibraryDeps[archAndLibraryKey{archDir, library}]; exists {
+				continue
+			}
+
+			// For each architecture-specific shared library dependency, we need to
+			// install it to the output directory. Setup the install destination here,
+			// which will be used by $(copy-many-files) in the Make backend.
+			archSharedLibraryDeps[archAndLibraryKey{archDir, library}] = true
+			installDestination := sharedLibraryInstallLocation(
+				library, ccModule.Host(), archString)
+			// Escape all the variables, as the install destination here will be called
+			// via. $(eval) in Make.
+			installDestination = strings.ReplaceAll(
+				installDestination, "$", "$$")
+			s.sharedLibInstallStrings = append(s.sharedLibInstallStrings,
+				library.String()+":"+installDestination)
+		}
+
 		// The executable.
 		archDirs[archDir] = append(archDirs[archDir],
 			fileToZip{ccModule.UnstrippedOutputFile(), ccModule.Name()})
@@ -280,6 +377,12 @@
 		}
 	})
 
+	// Add the shared library deps for packaging.
+	for key, _ := range archSharedLibraryDeps {
+		archDirs[key.ArchDir] = append(archDirs[key.ArchDir],
+			fileToZip{key.Library, "lib"})
+	}
+
 	for archDir, filesToZip := range archDirs {
 		arch := archDir.Base()
 		hostOrTarget := filepath.Base(filepath.Dir(archDir.String()))
@@ -302,9 +405,22 @@
 }
 
 func (s *fuzzPackager) MakeVars(ctx android.MakeVarsContext) {
+	packages := s.packages.Strings()
+	sort.Strings(packages)
+	sort.Strings(s.sharedLibInstallStrings)
 	// TODO(mitchp): Migrate this to use MakeVarsContext::DistForGoal() when it's
 	// ready to handle phony targets created in Soong. In the meantime, this
 	// exports the phony 'fuzz' target and dependencies on packages to
 	// core/main.mk so that we can use dist-for-goals.
-	ctx.Strict("SOONG_FUZZ_PACKAGING_ARCH_MODULES", strings.Join(s.packages.Strings(), " "))
+	ctx.Strict("SOONG_FUZZ_PACKAGING_ARCH_MODULES", strings.Join(packages, " "))
+	ctx.Strict("FUZZ_TARGET_SHARED_DEPS_INSTALL_PAIRS",
+		strings.Join(s.sharedLibInstallStrings, " "))
+
+	// Preallocate the slice of fuzz targets to minimise memory allocations.
+	fuzzTargets := make([]string, 0, len(s.fuzzTargets))
+	for target, _ := range s.fuzzTargets {
+		fuzzTargets = append(fuzzTargets, target)
+	}
+	sort.Strings(fuzzTargets)
+	ctx.Strict("ALL_FUZZ_TARGETS", strings.Join(fuzzTargets, " "))
 }
diff --git a/java/aar.go b/java/aar.go
index afe860c..d8db192 100644
--- a/java/aar.go
+++ b/java/aar.go
@@ -520,7 +520,7 @@
 }
 
 func (a *AARImport) sdkVersion() string {
-	return proptools.StringDefault(a.properties.Sdk_version, defaultSdkVersion(a))
+	return String(a.properties.Sdk_version)
 }
 
 func (a *AARImport) systemModules() string {
diff --git a/java/app.go b/java/app.go
index de12b73..d53d626 100644
--- a/java/app.go
+++ b/java/app.go
@@ -205,6 +205,7 @@
 
 func (a *AndroidApp) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	a.checkPlatformAPI(ctx)
+	a.checkSdkVersion(ctx)
 	a.generateAndroidBuildActions(ctx)
 }
 
diff --git a/java/app_test.go b/java/app_test.go
index 5b6ed54..7635f3d 100644
--- a/java/app_test.go
+++ b/java/app_test.go
@@ -666,6 +666,44 @@
 	}
 }
 
+func TestAppSdkVersionByPartition(t *testing.T) {
+	testJavaError(t, "sdk_version must have a value when the module is located at vendor or product", `
+		android_app {
+			name: "foo",
+			srcs: ["a.java"],
+			vendor: true,
+			platform_apis: true,
+		}
+	`)
+
+	testJava(t, `
+		android_app {
+			name: "bar",
+			srcs: ["b.java"],
+			platform_apis: true,
+		}
+	`)
+
+	for _, enforce := range []bool{true, false} {
+
+		config := testConfig(nil)
+		config.TestProductVariables.EnforceProductPartitionInterface = proptools.BoolPtr(enforce)
+		bp := `
+			android_app {
+				name: "foo",
+				srcs: ["a.java"],
+				product_specific: true,
+				platform_apis: true,
+			}
+		`
+		if enforce {
+			testJavaErrorWithConfig(t, "sdk_version must have a value when the module is located at vendor or product", bp, config)
+		} else {
+			testJavaWithConfig(t, bp, config)
+		}
+	}
+}
+
 func TestJNIPackaging(t *testing.T) {
 	ctx, _ := testJava(t, cc.GatherRequiredDepsForTest(android.Android)+`
 		cc_library {
diff --git a/java/config/config.go b/java/config/config.go
index 1c55961..333de32 100644
--- a/java/config/config.go
+++ b/java/config/config.go
@@ -87,12 +87,10 @@
 		return ctx.Config().Getenv("ANDROID_JAVA_HOME")
 	})
 	pctx.VariableFunc("JlinkVersion", func(ctx android.PackageVarContext) string {
-		switch ctx.Config().Getenv("EXPERIMENTAL_USE_OPENJDK11_TOOLCHAIN") {
-		case "false":
-			return "9"
-		default:
-			return "11"
+		if override := ctx.Config().Getenv("OVERRIDE_JLINK_VERSION_NUMBER"); override != "" {
+			return override
 		}
+		return "11"
 	})
 
 	pctx.SourcePathVariable("JavaToolchain", "${JavaHome}/bin")
diff --git a/java/dexpreopt_bootjars.go b/java/dexpreopt_bootjars.go
index 74ef667..a29665e 100644
--- a/java/dexpreopt_bootjars.go
+++ b/java/dexpreopt_bootjars.go
@@ -51,6 +51,7 @@
 
 type bootImageConfig struct {
 	name         string
+	stem         string
 	modules      []string
 	dexLocations []string
 	dexPaths     android.WritablePaths
@@ -71,7 +72,7 @@
 	// In addition, each .art file has an associated .oat and .vdex file, and an
 	// unstripped .oat file
 	for i, m := range image.modules {
-		name := image.name
+		name := image.stem
 		if i != 0 {
 			name += "-" + stemOf(m)
 		}
@@ -139,6 +140,12 @@
 	return false
 }
 
+func skipDexpreoptArtBootJars(ctx android.BuilderContext) bool {
+	// with EMMA_INSTRUMENT_FRAMEWORK=true ART boot class path libraries have dependencies on framework,
+	// therefore dexpreopt ART libraries cannot be dexpreopted in isolation => no ART boot image
+	return ctx.Config().IsEnvTrue("EMMA_INSTRUMENT_FRAMEWORK")
+}
+
 type dexpreoptBootJars struct {
 	defaultBootImage *bootImage
 	otherImages      []*bootImage
@@ -146,6 +153,14 @@
 	dexpreoptConfigForMake android.WritablePath
 }
 
+// Accessor function for the apex package. Returns nil if dexpreopt is disabled.
+func DexpreoptedArtApexJars(ctx android.BuilderContext) map[android.ArchType]android.Paths {
+	if skipDexpreoptBootJars(ctx) || skipDexpreoptArtBootJars(ctx) {
+		return nil
+	}
+	return artBootImageConfig(ctx).imagesDeps
+}
+
 // dexpreoptBoot singleton rules
 func (d *dexpreoptBootJars) GenerateBuildActions(ctx android.SingletonContext) {
 	if skipDexpreoptBootJars(ctx) {
@@ -169,7 +184,12 @@
 
 	// Always create the default boot image first, to get a unique profile rule for all images.
 	d.defaultBootImage = buildBootImage(ctx, defaultBootImageConfig(ctx))
+	if !skipDexpreoptArtBootJars(ctx) {
+		// Create boot image for the ART apex (build artifacts are accessed via the global boot image config).
+		buildBootImage(ctx, artBootImageConfig(ctx))
+	}
 	if global.GenerateApexImage {
+		// Create boot images for the JIT-zygote experiment.
 		d.otherImages = append(d.otherImages, buildBootImage(ctx, apexBootImageConfig(ctx)))
 	}
 
@@ -178,8 +198,6 @@
 
 // buildBootImage takes a bootImageConfig, creates rules to build it, and returns a *bootImage.
 func buildBootImage(ctx android.SingletonContext, config bootImageConfig) *bootImage {
-	global := dexpreoptGlobalConfig(ctx)
-
 	image := newBootImage(ctx, config)
 
 	bootDexJars := make(android.Paths, len(image.modules))
@@ -223,12 +241,9 @@
 	bootFrameworkProfileRule(ctx, image, missingDeps)
 
 	var allFiles android.Paths
-
-	if !global.DisablePreopt {
-		for _, target := range image.targets {
-			files := buildBootImageRuleForArch(ctx, image, target.Arch.ArchType, profile, missingDeps)
-			allFiles = append(allFiles, files.Paths()...)
-		}
+	for _, target := range image.targets {
+		files := buildBootImageRuleForArch(ctx, image, target.Arch.ArchType, profile, missingDeps)
+		allFiles = append(allFiles, files.Paths()...)
 	}
 
 	if image.zip != nil {
@@ -251,7 +266,7 @@
 	global := dexpreoptGlobalConfig(ctx)
 
 	symbolsDir := image.symbolsDir.Join(ctx, "system/framework", arch.String())
-	symbolsFile := symbolsDir.Join(ctx, image.name+".oat")
+	symbolsFile := symbolsDir.Join(ctx, image.stem+".oat")
 	outputDir := image.dir.Join(ctx, "system/framework", arch.String())
 	outputPath := image.images[arch]
 	oatLocation := pathtools.ReplaceExtension(dexpreopt.PathToLocation(outputPath, arch), "oat")
@@ -381,8 +396,9 @@
 	if global.DisableGenerateProfile || ctx.Config().IsPdkBuild() || ctx.Config().UnbundledBuild() {
 		return nil
 	}
-	return ctx.Config().Once(bootImageProfileRuleKey, func() interface{} {
+	profile := ctx.Config().Once(bootImageProfileRuleKey, func() interface{} {
 		tools := global.Tools
+		defaultProfile := "frameworks/base/config/boot-image-profile.txt"
 
 		rule := android.NewRuleBuilder()
 		rule.MissingDeps(missingDeps)
@@ -394,18 +410,13 @@
 			bootImageProfile = combinedBootImageProfile
 		} else if len(global.BootImageProfiles) == 1 {
 			bootImageProfile = global.BootImageProfiles[0]
+		} else if path := android.ExistentPathForSource(ctx, defaultProfile); path.Valid() {
+			bootImageProfile = path.Path()
 		} else {
-			// If not set, use the default.  Some branches like master-art-host don't have frameworks/base, so manually
-			// handle the case that the default is missing.  Those branches won't attempt to build the profile rule,
-			// and if they do they'll get a missing deps error.
-			defaultProfile := "frameworks/base/config/boot-image-profile.txt"
-			path := android.ExistentPathForSource(ctx, defaultProfile)
-			if path.Valid() {
-				bootImageProfile = path.Path()
-			} else {
-				missingDeps = append(missingDeps, defaultProfile)
-				bootImageProfile = android.PathForOutput(ctx, "missing")
-			}
+			// No profile (not even a default one, which is the case on some branches
+			// like master-art-host that don't have frameworks/base).
+			// Return nil and continue without profile.
+			return nil
 		}
 
 		profile := image.dir.Join(ctx, "boot.prof")
@@ -425,7 +436,11 @@
 		image.profileInstalls = rule.Installs()
 
 		return profile
-	}).(android.WritablePath)
+	})
+	if profile == nil {
+		return nil // wrap nil into a typed pointer with value nil
+	}
+	return profile.(android.WritablePath)
 }
 
 var bootImageProfileRuleKey = android.NewOnceKey("bootImageProfileRule")
diff --git a/java/dexpreopt_bootjars_test.go b/java/dexpreopt_bootjars_test.go
index 244bd52..a684ab2 100644
--- a/java/dexpreopt_bootjars_test.go
+++ b/java/dexpreopt_bootjars_test.go
@@ -62,7 +62,6 @@
 	bootArt := dexpreoptBootJars.Output("boot.art")
 
 	expectedInputs := []string{
-		"dex_bootjars/boot.prof",
 		"dex_bootjars_input/foo.jar",
 		"dex_bootjars_input/bar.jar",
 		"dex_bootjars_input/baz.jar",
diff --git a/java/dexpreopt_config.go b/java/dexpreopt_config.go
index b3b1317..a6661b3 100644
--- a/java/dexpreopt_config.go
+++ b/java/dexpreopt_config.go
@@ -106,15 +106,20 @@
 	return moduleName
 }
 
-func getBootImageConfig(ctx android.PathContext, key android.OnceKey, name string,
-	needZip bool) bootImageConfig {
+// Construct a variant of the global config for dexpreopted bootclasspath jars. The variants differ
+// in the list of input jars (libcore, framework, or both), in the naming scheme for the dexpreopt
+// files (ART recognizes "apex" names as special), and whether to include a zip archive.
+//
+// 'name' is a string unique for each profile (used in directory names and ninja rule names)
+// 'stem' is the basename of the image: the resulting filenames are <stem>[-<jar>].{art,oat,vdex}.
+func getBootImageConfig(ctx android.PathContext, key android.OnceKey, name string, stem string,
+	needZip bool, artApexJarsOnly bool) bootImageConfig {
+
 	return ctx.Config().Once(key, func() interface{} {
 		global := dexpreoptGlobalConfig(ctx)
 
 		artModules := global.ArtApexJars
-		nonFrameworkModules := concat(artModules, global.ProductUpdatableBootModules)
-		frameworkModules := android.RemoveListFromList(global.BootJars, nonFrameworkModules)
-		imageModules := concat(artModules, frameworkModules)
+		imageModules := artModules
 
 		var bootLocations []string
 
@@ -123,9 +128,15 @@
 				filepath.Join("/apex/com.android.art/javalib", stemOf(m)+".jar"))
 		}
 
-		for _, m := range frameworkModules {
-			bootLocations = append(bootLocations,
-				filepath.Join("/system/framework", stemOf(m)+".jar"))
+		if !artApexJarsOnly {
+			nonFrameworkModules := concat(artModules, global.ProductUpdatableBootModules)
+			frameworkModules := android.RemoveListFromList(global.BootJars, nonFrameworkModules)
+			imageModules = concat(imageModules, frameworkModules)
+
+			for _, m := range frameworkModules {
+				bootLocations = append(bootLocations,
+					filepath.Join("/system/framework", stemOf(m)+".jar"))
+			}
 		}
 
 		// The path to bootclasspath dex files needs to be known at module GenerateAndroidBuildAction time, before
@@ -143,13 +154,14 @@
 
 		var zip android.WritablePath
 		if needZip {
-			zip = dir.Join(ctx, name+".zip")
+			zip = dir.Join(ctx, stem+".zip")
 		}
 
 		targets := dexpreoptTargets(ctx)
 
 		imageConfig := bootImageConfig{
 			name:         name,
+			stem:         stem,
 			modules:      imageModules,
 			dexLocations: bootLocations,
 			dexPaths:     bootDexPaths,
@@ -163,7 +175,7 @@
 
 		for _, target := range targets {
 			imageDir := dir.Join(ctx, "system/framework", target.Arch.ArchType.String())
-			imageConfig.images[target.Arch.ArchType] = imageDir.Join(ctx, name+".art")
+			imageConfig.images[target.Arch.ArchType] = imageDir.Join(ctx, stem+".art")
 
 			imagesDeps := make([]android.Path, 0, len(imageConfig.modules)*3)
 			for _, dep := range imageConfig.moduleFiles(ctx, imageDir, ".art", ".oat", ".vdex") {
@@ -176,15 +188,25 @@
 	}).(bootImageConfig)
 }
 
+// Default config is the one that goes in the system image. It includes both libcore and framework.
 var defaultBootImageConfigKey = android.NewOnceKey("defaultBootImageConfig")
-var apexBootImageConfigKey = android.NewOnceKey("apexBootImageConfig")
 
 func defaultBootImageConfig(ctx android.PathContext) bootImageConfig {
-	return getBootImageConfig(ctx, defaultBootImageConfigKey, "boot", true)
+	return getBootImageConfig(ctx, defaultBootImageConfigKey, "boot", "boot", true, false)
 }
 
+// Apex config is used for the JIT-zygote experiment. It includes both libcore and framework, but AOT-compiles only libcore.
+var apexBootImageConfigKey = android.NewOnceKey("apexBootImageConfig")
+
 func apexBootImageConfig(ctx android.PathContext) bootImageConfig {
-	return getBootImageConfig(ctx, apexBootImageConfigKey, "apex", false)
+	return getBootImageConfig(ctx, apexBootImageConfigKey, "apex", "apex", false, false)
+}
+
+// ART config is the one used for the ART apex. It includes only libcore.
+var artBootImageConfigKey = android.NewOnceKey("artBootImageConfig")
+
+func artBootImageConfig(ctx android.PathContext) bootImageConfig {
+	return getBootImageConfig(ctx, artBootImageConfigKey, "art", "boot", false, true)
 }
 
 func defaultBootclasspath(ctx android.PathContext) []string {
diff --git a/java/droiddoc.go b/java/droiddoc.go
index 5d01b54..54f93fe 100644
--- a/java/droiddoc.go
+++ b/java/droiddoc.go
@@ -404,7 +404,7 @@
 var _ android.OutputFileProducer = (*Javadoc)(nil)
 
 func (j *Javadoc) sdkVersion() string {
-	return proptools.StringDefault(j.properties.Sdk_version, defaultSdkVersion(j))
+	return String(j.properties.Sdk_version)
 }
 
 func (j *Javadoc) systemModules() string {
@@ -1325,13 +1325,8 @@
 		validatingNullability :=
 			strings.Contains(d.Javadoc.args, "--validate-nullability-from-merged-stubs") ||
 				String(d.properties.Validate_nullability_from_list) != ""
+
 		migratingNullability := String(d.properties.Previous_api) != ""
-
-		if !(migratingNullability || validatingNullability) {
-			ctx.PropertyErrorf("previous_api",
-				"has to be non-empty if annotations was enabled (unless validating nullability)")
-		}
-
 		if migratingNullability {
 			previousApi := android.PathForModuleSrc(ctx, String(d.properties.Previous_api))
 			cmd.FlagWithInput("--migrate-nullness ", previousApi)
diff --git a/java/java.go b/java/java.go
index 88f5d87..9bbdff7 100644
--- a/java/java.go
+++ b/java/java.go
@@ -54,6 +54,18 @@
 	android.RegisterSingletonType("kythe_java_extract", kytheExtractJavaFactory)
 }
 
+func (j *Module) checkSdkVersion(ctx android.ModuleContext) {
+	if j.SocSpecific() || j.DeviceSpecific() ||
+		(j.ProductSpecific() && ctx.Config().EnforceProductPartitionInterface()) {
+		if sc, ok := ctx.Module().(sdkContext); ok {
+			if sc.sdkVersion() == "" {
+				ctx.PropertyErrorf("sdk_version",
+					"sdk_version must have a value when the module is located at vendor or product(only if PRODUCT_ENFORCE_PRODUCT_PARTITION_INTERFACE is set).")
+			}
+		}
+	}
+}
+
 func (j *Module) checkPlatformAPI(ctx android.ModuleContext) {
 	if sc, ok := ctx.Module().(sdkContext); ok {
 		usePlatformAPI := proptools.Bool(j.deviceProperties.Platform_apis)
@@ -430,6 +442,11 @@
 	target android.Target
 }
 
+func IsJniDepTag(depTag blueprint.DependencyTag) bool {
+	_, ok := depTag.(*jniDependencyTag)
+	return ok
+}
+
 var (
 	staticLibTag          = dependencyTag{name: "staticlib"}
 	libTag                = dependencyTag{name: "javalib"}
@@ -447,18 +464,6 @@
 	usesLibTag            = dependencyTag{name: "uses-library"}
 )
 
-func defaultSdkVersion(ctx checkVendorModuleContext) string {
-	if ctx.SocSpecific() || ctx.DeviceSpecific() {
-		return "system_current"
-	}
-	return ""
-}
-
-type checkVendorModuleContext interface {
-	SocSpecific() bool
-	DeviceSpecific() bool
-}
-
 type sdkDep struct {
 	useModule, useFiles, useDefaultLibs, invalidVersion bool
 
@@ -505,7 +510,7 @@
 }
 
 func (j *Module) sdkVersion() string {
-	return proptools.StringDefault(j.deviceProperties.Sdk_version, defaultSdkVersion(j))
+	return String(j.deviceProperties.Sdk_version)
 }
 
 func (j *Module) systemModules() string {
@@ -1636,6 +1641,7 @@
 }
 
 func (j *Library) GenerateAndroidBuildActions(ctx android.ModuleContext) {
+	j.checkSdkVersion(ctx)
 	j.dexpreopter.installPath = android.PathForModuleInstall(ctx, "framework", j.Stem()+".jar")
 	j.dexpreopter.isSDKLibrary = j.deviceProperties.IsSDKLibrary
 	j.dexpreopter.isInstallable = Bool(j.properties.Installable)
@@ -1979,7 +1985,7 @@
 }
 
 func (j *Import) sdkVersion() string {
-	return proptools.StringDefault(j.properties.Sdk_version, defaultSdkVersion(j))
+	return String(j.properties.Sdk_version)
 }
 
 func (j *Import) minSdkVersion() string {
diff --git a/java/java_test.go b/java/java_test.go
index a6ae503..e7b68dd 100644
--- a/java/java_test.go
+++ b/java/java_test.go
@@ -23,6 +23,8 @@
 	"strings"
 	"testing"
 
+	"github.com/google/blueprint/proptools"
+
 	"android/soong/android"
 	"android/soong/cc"
 	"android/soong/dexpreopt"
@@ -228,9 +230,13 @@
 	android.FailIfErrored(t, errs)
 }
 
-func testJavaError(t *testing.T, pattern string, bp string) {
+func testJavaError(t *testing.T, pattern string, bp string) (*android.TestContext, android.Config) {
 	t.Helper()
-	config := testConfig(nil)
+	return testJavaErrorWithConfig(t, pattern, bp, testConfig(nil))
+}
+
+func testJavaErrorWithConfig(t *testing.T, pattern string, bp string, config android.Config) (*android.TestContext, android.Config) {
+	t.Helper()
 	ctx := testContext(bp, nil)
 
 	pathCtx := android.PathContextForTesting(config, nil)
@@ -240,20 +246,26 @@
 	_, errs := ctx.ParseBlueprintsFiles("Android.bp")
 	if len(errs) > 0 {
 		android.FailIfNoMatchingErrors(t, pattern, errs)
-		return
+		return ctx, config
 	}
 	_, errs = ctx.PrepareBuildActions(config)
 	if len(errs) > 0 {
 		android.FailIfNoMatchingErrors(t, pattern, errs)
-		return
+		return ctx, config
 	}
 
 	t.Fatalf("missing expected error %q (0 errors are returned)", pattern)
+
+	return ctx, config
 }
 
 func testJava(t *testing.T, bp string) (*android.TestContext, android.Config) {
 	t.Helper()
-	config := testConfig(nil)
+	return testJavaWithConfig(t, bp, testConfig(nil))
+}
+
+func testJavaWithConfig(t *testing.T, bp string, config android.Config) (*android.TestContext, android.Config) {
+	t.Helper()
 	ctx := testContext(bp, nil)
 	run(t, ctx, config)
 
@@ -315,29 +327,38 @@
 	}
 }
 
-func TestSdkVersion(t *testing.T) {
-	ctx, _ := testJava(t, `
+func TestSdkVersionByPartition(t *testing.T) {
+	testJavaError(t, "sdk_version must have a value when the module is located at vendor or product", `
 		java_library {
 			name: "foo",
 			srcs: ["a.java"],
 			vendor: true,
 		}
+	`)
 
+	testJava(t, `
 		java_library {
 			name: "bar",
 			srcs: ["b.java"],
 		}
 	`)
 
-	foo := ctx.ModuleForTests("foo", "android_common").Module().(*Library)
-	bar := ctx.ModuleForTests("bar", "android_common").Module().(*Library)
+	for _, enforce := range []bool{true, false} {
 
-	if foo.sdkVersion() != "system_current" {
-		t.Errorf("If sdk version of vendor module is empty, it must change to system_current.")
-	}
-
-	if bar.sdkVersion() != "" {
-		t.Errorf("If sdk version of non-vendor module is empty, it keeps empty.")
+		config := testConfig(nil)
+		config.TestProductVariables.EnforceProductPartitionInterface = proptools.BoolPtr(enforce)
+		bp := `
+			java_library {
+				name: "foo",
+				srcs: ["a.java"],
+				product_specific: true,
+			}
+		`
+		if enforce {
+			testJavaErrorWithConfig(t, "sdk_version must have a value when the module is located at vendor or product", bp, config)
+		} else {
+			testJavaWithConfig(t, bp, config)
+		}
 	}
 }
 
diff --git a/ui/build/config.go b/ui/build/config.go
index 686ca3e..92aee4d 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -219,8 +219,8 @@
 		if override, ok := ret.environ.Get("OVERRIDE_ANDROID_JAVA_HOME"); ok {
 			return override
 		}
-		if toolchain9, ok := ret.environ.Get("EXPERIMENTAL_USE_OPENJDK11_TOOLCHAIN"); ok && toolchain9 == "false" {
-			return java9Home
+		if toolchain11, ok := ret.environ.Get("EXPERIMENTAL_USE_OPENJDK11_TOOLCHAIN"); ok && toolchain11 != "true" {
+			ctx.Fatalln("The environment variable EXPERIMENTAL_USE_OPENJDK11_TOOLCHAIN is no longer supported. An OpenJDK 11 toolchain is now the global default.")
 		}
 		return java11Home
 	}()