Merge "Adds min_sdk_version to device_kernel_headers headers lib."
diff --git a/OWNERS b/OWNERS
index 937a243..0cfb241 100644
--- a/OWNERS
+++ b/OWNERS
@@ -6,6 +6,7 @@
 alexmarquez@google.com
 asmundak@google.com
 ccross@android.com
+colefaust@google.com
 cparsons@google.com
 delmerico@google.com
 dwillemsen@google.com
diff --git a/android/api_levels.go b/android/api_levels.go
index 926d297..de56625 100644
--- a/android/api_levels.go
+++ b/android/api_levels.go
@@ -321,6 +321,7 @@
 			"Q":     29,
 			"R":     30,
 			"S":     31,
+			"S-V2":  32,
 		}
 
 		// TODO: Differentiate "current" and "future".
@@ -364,6 +365,7 @@
 			"Q":     29,
 			"R":     30,
 			"S":     31,
+			"S-V2":  32,
 		}
 		for i, codename := range config.PlatformVersionActiveCodenames() {
 			apiLevelsMap[codename] = previewAPILevelBase + i
diff --git a/android/arch.go b/android/arch.go
index 8aa8d40..6b81022 100644
--- a/android/arch.go
+++ b/android/arch.go
@@ -909,6 +909,7 @@
 			"Glibc",
 			"Musl",
 			"Linux",
+			"Host_linux",
 			"Not_windows",
 			"Arm_on_x86",
 			"Arm_on_x86_64",
@@ -930,6 +931,12 @@
 						targets = append(targets, target)
 					}
 				}
+				if os.Linux() && os.Class == Host {
+					target := "Host_linux_" + archType.Name
+					if !InList(target, targets) {
+						targets = append(targets, target)
+					}
+				}
 				if os.Bionic() {
 					target := "Bionic_" + archType.Name
 					if !InList(target, targets) {
@@ -1162,6 +1169,14 @@
 				}
 			}
 
+			if os.Linux() && os.Class == Host {
+				field := "Host_linux"
+				prefix := "target.host_linux"
+				if linuxProperties, ok := getChildPropertyStruct(ctx, targetProp, field, prefix); ok {
+					mergePropertyStruct(ctx, genProps, linuxProperties)
+				}
+			}
+
 			if os.Bionic() {
 				field := "Bionic"
 				prefix := "target.bionic"
@@ -2127,6 +2142,7 @@
 	linuxStructs := getTargetStructs(ctx, archProperties, "Linux")
 	bionicStructs := getTargetStructs(ctx, archProperties, "Bionic")
 	hostStructs := getTargetStructs(ctx, archProperties, "Host")
+	hostLinuxStructs := getTargetStructs(ctx, archProperties, "Host_linux")
 	hostNotWindowsStructs := getTargetStructs(ctx, archProperties, "Not_windows")
 
 	// For android, linux, ...
@@ -2147,6 +2163,9 @@
 		if os.Bionic() {
 			osStructs = append(osStructs, bionicStructs...)
 		}
+		if os.Linux() && os.Class == Host {
+			osStructs = append(osStructs, hostLinuxStructs...)
+		}
 
 		if os == LinuxMusl {
 			osStructs = append(osStructs, getTargetStructs(ctx, archProperties, "Musl")...)
@@ -2179,6 +2198,16 @@
 				targetStructs := getTargetStructs(ctx, archProperties, targetField)
 				osArchStructs = append(osArchStructs, targetStructs...)
 			}
+			if os == LinuxMusl {
+				targetField := "Musl_" + arch.Name
+				targetStructs := getTargetStructs(ctx, archProperties, targetField)
+				osArchStructs = append(osArchStructs, targetStructs...)
+			}
+			if os == Linux {
+				targetField := "Glibc_" + arch.Name
+				targetStructs := getTargetStructs(ctx, archProperties, targetField)
+				osArchStructs = append(osArchStructs, targetStructs...)
+			}
 
 			targetField := GetCompoundTargetField(os, arch)
 			targetName := fmt.Sprintf("%s_%s", os.Name, arch.Name)
diff --git a/android/arch_test.go b/android/arch_test.go
index 7caf837..68dc7f5 100644
--- a/android/arch_test.go
+++ b/android/arch_test.go
@@ -510,6 +510,7 @@
 				musl: { a:  ["musl"] },
 				linux_bionic: { a:  ["linux_bionic"] },
 				linux: { a:  ["linux"] },
+				host_linux: { a: ["host_linux"] },
 				linux_glibc: { a:  ["linux_glibc"] },
 				linux_musl: { a:  ["linux_musl"] },
 				windows: { a:  ["windows"], enabled: true },
@@ -566,12 +567,12 @@
 				{
 					module:   "foo",
 					variant:  "linux_glibc_x86_64",
-					property: []string{"root", "host", "linux", "glibc", "linux_glibc", "not_windows", "x86_64", "lib64", "linux_x86_64", "linux_glibc_x86_64"},
+					property: []string{"root", "host", "linux", "host_linux", "glibc", "linux_glibc", "not_windows", "x86_64", "lib64", "linux_x86_64", "linux_glibc_x86_64"},
 				},
 				{
 					module:   "foo",
 					variant:  "linux_glibc_x86",
-					property: []string{"root", "host", "linux", "glibc", "linux_glibc", "not_windows", "x86", "lib32", "linux_x86", "linux_glibc_x86"},
+					property: []string{"root", "host", "linux", "host_linux", "glibc", "linux_glibc", "not_windows", "x86", "lib32", "linux_x86", "linux_glibc_x86"},
 				},
 			},
 		},
@@ -605,12 +606,12 @@
 				{
 					module:   "foo",
 					variant:  "linux_musl_x86_64",
-					property: []string{"root", "host", "linux", "musl", "linux_glibc", "linux_musl", "not_windows", "x86_64", "lib64", "linux_x86_64", "linux_musl_x86_64", "linux_glibc_x86_64"},
+					property: []string{"root", "host", "linux", "host_linux", "musl", "linux_glibc", "linux_musl", "not_windows", "x86_64", "lib64", "linux_x86_64", "linux_musl_x86_64", "linux_glibc_x86_64"},
 				},
 				{
 					module:   "foo",
 					variant:  "linux_musl_x86",
-					property: []string{"root", "host", "linux", "musl", "linux_glibc", "linux_musl", "not_windows", "x86", "lib32", "linux_x86", "linux_musl_x86", "linux_glibc_x86"},
+					property: []string{"root", "host", "linux", "host_linux", "musl", "linux_glibc", "linux_musl", "not_windows", "x86", "lib32", "linux_x86", "linux_musl_x86", "linux_glibc_x86"},
 				},
 			},
 		},
diff --git a/android/bazel.go b/android/bazel.go
index 410cec3..0617367 100644
--- a/android/bazel.go
+++ b/android/bazel.go
@@ -208,6 +208,7 @@
 		"build/bazel/tests":/* recursive = */ true,
 		"build/bazel/platforms":/* recursive = */ true,
 		"build/bazel/product_variables":/* recursive = */ true,
+		"build/bazel/vendor/google":/* recursive = */ true,
 		"build/bazel_common_rules":/* recursive = */ true,
 		// build/make/tools/signapk BUILD file is generated, so build/make/tools is not recursive.
 		"build/make/tools":/* recursive = */ false,
@@ -225,6 +226,7 @@
 		"packages/apps/QuickSearchBox":/* recursive = */ true,
 		"packages/apps/WallpaperPicker":/* recursive = */ false,
 
+		"prebuilts/bundletool":/* recursive = */ true,
 		"prebuilts/gcc":/* recursive = */ true,
 		"prebuilts/build-tools":/* recursive = */ false,
 		"prebuilts/jdk/jdk11":/* recursive = */ false,
@@ -291,12 +293,14 @@
 		"development/samples/WiFiDirectDemo":                 Bp2BuildDefaultTrue,
 		"development/sdk":                                    Bp2BuildDefaultTrueRecursively,
 		"external/arm-optimized-routines":                    Bp2BuildDefaultTrueRecursively,
+		"external/auto/android-annotation-stubs":             Bp2BuildDefaultTrueRecursively,
 		"external/auto/common":                               Bp2BuildDefaultTrueRecursively,
 		"external/auto/service":                              Bp2BuildDefaultTrueRecursively,
 		"external/boringssl":                                 Bp2BuildDefaultTrueRecursively,
 		"external/bouncycastle":                              Bp2BuildDefaultTrue,
 		"external/brotli":                                    Bp2BuildDefaultTrue,
 		"external/conscrypt":                                 Bp2BuildDefaultTrue,
+		"external/e2fsprogs":                                 Bp2BuildDefaultTrueRecursively,
 		"external/error_prone":                               Bp2BuildDefaultTrueRecursively,
 		"external/fmtlib":                                    Bp2BuildDefaultTrueRecursively,
 		"external/google-benchmark":                          Bp2BuildDefaultTrueRecursively,
@@ -383,8 +387,36 @@
 	}
 
 	// Per-module allowlist to always opt modules in of both bp2build and mixed builds.
+	// These modules are usually in directories with many other modules that are not ready for
+	// conversion.
+	//
+	// A module can either be in this list or its directory allowlisted entirely
+	// in bp2buildDefaultConfig, but not both at the same time.
 	bp2buildModuleAlwaysConvertList = []string{
 		"junit-params-assertj-core",
+
+		//external/avb
+		"avbtool",
+		"libavb",
+		"avb_headers",
+
+		//external/fec
+		"libfec_rs",
+
+		//system/core/libsparse
+		"libsparse",
+
+		//system/extras/ext4_utils
+		"libext4_utils",
+
+		//system/extras/libfec
+		"libfec",
+
+		//system/extras/squashfs_utils
+		"libsquashfs_utils",
+
+		//system/extras/verity/fec
+		"fec",
 	}
 
 	// Per-module denylist to always opt modules out of both bp2build and mixed builds.
@@ -453,11 +485,12 @@
 		"conscrypt",          // b/210751803, we don't handle path property for filegroups
 		"conscrypt-for-host", // b/210751803, we don't handle path property for filegroups
 
-		"host-libprotobuf-java-lite",  // b/217236083, java_library cannot have deps without srcs
-		"host-libprotobuf-java-micro", // b/217236083, java_library cannot have deps without srcs
-		"host-libprotobuf-java-nano",  // b/217236083, java_library cannot have deps without srcs
-		"error_prone_core",            // b/217236083, java_library cannot have deps without srcs
-		"bouncycastle-host",           // b/217236083, java_library cannot have deps without srcs
+		"host-libprotobuf-java-lite",   // b/217236083, java_library cannot have deps without srcs
+		"host-libprotobuf-java-micro",  // b/217236083, java_library cannot have deps without srcs
+		"host-libprotobuf-java-nano",   // b/217236083, java_library cannot have deps without srcs
+		"error_prone_core",             // b/217236083, java_library cannot have deps without srcs
+		"bouncycastle-host",            // b/217236083, java_library cannot have deps without srcs
+		"mockito-robolectric-prebuilt", // b/217236083, java_library cannot have deps without srcs
 
 		"apex_manifest_proto_java", // b/215230097, we don't handle .proto files in java_library srcs attribute
 
@@ -527,6 +560,8 @@
 		"dex2oat-script", // depends on unconverted modules: dex2oat
 
 		"error_prone_checkerframework_dataflow_nullaway", // TODO(b/219908977): "Error in fail: deps not allowed without srcs; move to runtime_deps?"
+
+		"libprotobuf-java-nano", // b/220869005, depends on non-public_current SDK
 	}
 
 	// Per-module denylist of cc_library modules to only generate the static
@@ -679,14 +714,21 @@
 	}
 
 	packagePath := ctx.OtherModuleDir(module)
-	config := ctx.Config().bp2buildPackageConfig
+	if alwaysConvert && ShouldKeepExistingBuildFileForDir(packagePath) {
+		ctx.(BaseModuleContext).ModuleErrorf("A module cannot be in a directory listed in bp2buildKeepExistingBuildFile"+
+			" and also be in bp2buildModuleAlwaysConvert. Directory: '%s'", packagePath)
 
+		return false
+	}
+
+	config := ctx.Config().bp2buildPackageConfig
 	// This is a tristate value: true, false, or unset.
 	propValue := b.bazelProperties.Bazel_module.Bp2build_available
 	if bp2buildDefaultTrueRecursively(packagePath, config) {
 		if alwaysConvert {
-			ctx.(BaseModuleContext).ModuleErrorf("a module cannot be in a directory marked Bp2BuildDefaultTrue" +
-				" or Bp2BuildDefaultTrueRecursively and also be in bp2buildModuleAlwaysConvert")
+			ctx.(BaseModuleContext).ModuleErrorf("A module cannot be in a directory marked Bp2BuildDefaultTrue"+
+				" or Bp2BuildDefaultTrueRecursively and also be in bp2buildModuleAlwaysConvert. Directory: '%s'",
+				packagePath)
 		}
 
 		// Allow modules to explicitly opt-out.
diff --git a/android/config.go b/android/config.go
index 3d8bc31..e8ca84c 100644
--- a/android/config.go
+++ b/android/config.go
@@ -1256,6 +1256,10 @@
 	return Bool(c.config.productVariables.ClangCoverage)
 }
 
+func (c *deviceConfig) ClangCoverageContinuousMode() bool {
+	return Bool(c.config.productVariables.ClangCoverageContinuousMode)
+}
+
 func (c *deviceConfig) GcovCoverageEnabled() bool {
 	return Bool(c.config.productVariables.GcovCoverage)
 }
diff --git a/android/hooks.go b/android/hooks.go
index bded764..5e3a4a7 100644
--- a/android/hooks.go
+++ b/android/hooks.go
@@ -15,7 +15,10 @@
 package android
 
 import (
+	"fmt"
+	"path"
 	"reflect"
+	"runtime"
 
 	"github.com/google/blueprint"
 	"github.com/google/blueprint/proptools"
@@ -88,7 +91,19 @@
 
 func (l *loadHookContext) CreateModule(factory ModuleFactory, props ...interface{}) Module {
 	inherited := []interface{}{&l.Module().base().commonProperties}
-	module := l.bp.CreateModule(ModuleFactoryAdaptor(factory), append(inherited, props...)...).(Module)
+
+	var typeName string
+	if typeNameLookup, ok := ModuleTypeByFactory()[reflect.ValueOf(factory)]; ok {
+		typeName = typeNameLookup
+	} else {
+		factoryPtr := reflect.ValueOf(factory).Pointer()
+		factoryFunc := runtime.FuncForPC(factoryPtr)
+		filePath, _ := factoryFunc.FileLine(factoryPtr)
+		typeName = fmt.Sprintf("%s_%s", path.Base(filePath), factoryFunc.Name())
+	}
+	typeName = typeName + "_loadHookModule"
+
+	module := l.bp.CreateModule(ModuleFactoryAdaptor(factory), typeName, append(inherited, props...)...).(Module)
 
 	if l.Module().base().variableProperties != nil && module.base().variableProperties != nil {
 		src := l.Module().base().variableProperties
diff --git a/android/module.go b/android/module.go
index 03d3f80..43509c0 100644
--- a/android/module.go
+++ b/android/module.go
@@ -456,6 +456,10 @@
 	// GetMissingDependencies returns the list of dependencies that were passed to AddDependencies or related methods,
 	// but do not exist.
 	GetMissingDependencies() []string
+
+	// LicenseMetadataFile returns the path where the license metadata for this module will be
+	// generated.
+	LicenseMetadataFile() Path
 }
 
 type Module interface {
@@ -3279,6 +3283,10 @@
 	return m.bp
 }
 
+func (m *moduleContext) LicenseMetadataFile() Path {
+	return m.module.base().licenseMetadataFile
+}
+
 // SrcIsModule decodes module references in the format ":unqualified-name" or "//namespace:name"
 // into the module name, or empty string if the input was not a module reference.
 func SrcIsModule(s string) (module string) {
diff --git a/android/paths.go b/android/paths.go
index 05caebd..e7829b9 100644
--- a/android/paths.go
+++ b/android/paths.go
@@ -1474,14 +1474,11 @@
 func PathForVndkRefAbiDump(ctx ModuleInstallPathContext, version, fileName string,
 	isNdk, isLlndkOrVndk, isGzip bool) OptionalPath {
 
-	arches := ctx.DeviceConfig().Arches()
-	if len(arches) == 0 {
-		panic("device build with no primary arch")
-	}
-	currentArch := ctx.Arch()
-	archNameAndVariant := currentArch.ArchType.String()
-	if currentArch.ArchVariant != "" {
-		archNameAndVariant += "_" + currentArch.ArchVariant
+	currentArchType := ctx.Arch().ArchType
+	primaryArchType := ctx.Config().DevicePrimaryArchType()
+	archName := currentArchType.String()
+	if currentArchType != primaryArchType {
+		archName += "_" + primaryArchType.String()
 	}
 
 	var dirName string
@@ -1503,7 +1500,7 @@
 	}
 
 	return ExistentPathForSource(ctx, "prebuilts", "abi-dumps", dirName,
-		version, binderBitness, archNameAndVariant, "source-based",
+		version, binderBitness, archName, "source-based",
 		fileName+ext)
 }
 
diff --git a/android/register.go b/android/register.go
index 10e14e0..c505833 100644
--- a/android/register.go
+++ b/android/register.go
@@ -59,6 +59,7 @@
 
 var moduleTypes []moduleType
 var moduleTypesForDocs = map[string]reflect.Value{}
+var moduleTypeByFactory = map[reflect.Value]string{}
 
 type singleton struct {
 	// True if this should be registered as a pre-singleton, false otherwise.
@@ -140,6 +141,7 @@
 // RegisterModuleType was a lambda.
 func RegisterModuleTypeForDocs(name string, factory reflect.Value) {
 	moduleTypesForDocs[name] = factory
+	moduleTypeByFactory[factory] = name
 }
 
 func RegisterSingletonType(name string, factory SingletonFactory) {
@@ -228,6 +230,10 @@
 	return moduleTypesForDocs
 }
 
+func ModuleTypeByFactory() map[reflect.Value]string {
+	return moduleTypeByFactory
+}
+
 // Interface for registering build components.
 //
 // Provided to allow registration of build components to be shared between the runtime
diff --git a/android/variable.go b/android/variable.go
index 68f19b9..37037eb 100644
--- a/android/variable.go
+++ b/android/variable.go
@@ -306,10 +306,11 @@
 	JavaCoveragePaths        []string `json:",omitempty"`
 	JavaCoverageExcludePaths []string `json:",omitempty"`
 
-	GcovCoverage               *bool    `json:",omitempty"`
-	ClangCoverage              *bool    `json:",omitempty"`
-	NativeCoveragePaths        []string `json:",omitempty"`
-	NativeCoverageExcludePaths []string `json:",omitempty"`
+	GcovCoverage                *bool    `json:",omitempty"`
+	ClangCoverage               *bool    `json:",omitempty"`
+	NativeCoveragePaths         []string `json:",omitempty"`
+	NativeCoverageExcludePaths  []string `json:",omitempty"`
+	ClangCoverageContinuousMode *bool    `json:",omitempty"`
 
 	// Set by NewConfig
 	Native_coverage *bool `json:",omitempty"`
diff --git a/androidmk/androidmk/android.go b/androidmk/androidmk/android.go
index 295b0e5..954f8d0 100644
--- a/androidmk/androidmk/android.go
+++ b/androidmk/androidmk/android.go
@@ -17,6 +17,7 @@
 import (
 	"fmt"
 	"sort"
+	"strconv"
 	"strings"
 
 	mkparser "android/soong/androidmk/parser"
@@ -623,6 +624,16 @@
 	return err
 }
 
+// Assigns a given boolean value to a given variable in the result bp file. See
+// setVariable documentation for more information about prefix and name.
+func makeBlueprintBoolAssignment(ctx variableAssignmentContext, prefix, name string, value bool) error {
+	expressionValue, err := stringToBoolValue(strconv.FormatBool(value))
+	if err == nil {
+		err = setVariable(ctx.file, false, prefix, name, expressionValue, true)
+	}
+	return err
+}
+
 // If variable is a literal variable name, return the name, otherwise return ""
 func varLiteralName(variable mkparser.Variable) string {
 	if len(variable.Name.Variables) == 0 {
@@ -647,7 +658,11 @@
 	varname := ""
 	fixed := ""
 	val := ctx.mkvalue
+
 	if len(val.Variables) == 1 && varLiteralName(val.Variables[0]) != "" && len(val.Strings) == 2 && val.Strings[0] == "" {
+		if varLiteralName(val.Variables[0]) == "PRODUCT_OUT" && val.Strings[1] == "/system/priv-app" {
+			return makeBlueprintBoolAssignment(ctx, "", "privileged", true)
+		}
 		fixed = val.Strings[1]
 		varname = val.Variables[0].Name.Strings[0]
 		// TARGET_OUT_OPTIONAL_EXECUTABLES puts the artifact in xbin, which is
diff --git a/androidmk/androidmk/androidmk.go b/androidmk/androidmk/androidmk.go
index b8316a3..aaafdc7 100644
--- a/androidmk/androidmk/androidmk.go
+++ b/androidmk/androidmk/androidmk.go
@@ -411,6 +411,24 @@
 	return exp, nil
 }
 
+// If local is set to true, then the variable will be added as a part of the
+// variable at file.bpPos. For example, if file.bpPos references a module,
+// then calling this method will set a property on that module if local is set
+// to true. Otherwise, the Variable will be created at the root of the file.
+//
+// prefix should be populated with the top level value to be assigned, and
+// name with a sub-value. If prefix is empty, then name is the top level value.
+// For example, if prefix is "foo" and name is "bar" with a value of "baz", then
+// the following variable will be generated:
+//
+// foo {
+//   bar: "baz"
+// }
+//
+// If prefix is the empty string and name is "foo" with a value of "bar", the
+// following variable will be generated (if it is a property):
+//
+// foo: "bar"
 func setVariable(file *bpFile, plusequals bool, prefix, name string, value bpparser.Expression, local bool) error {
 	if prefix != "" {
 		name = prefix + "." + name
diff --git a/androidmk/androidmk/androidmk_test.go b/androidmk/androidmk/androidmk_test.go
index e8b6f78..2176361 100644
--- a/androidmk/androidmk/androidmk_test.go
+++ b/androidmk/androidmk/androidmk_test.go
@@ -1675,6 +1675,21 @@
 }
 `,
 	},
+	{
+		desc: "privileged app",
+		in: `
+include $(CLEAR_VARS)
+LOCAL_MODULE := foo
+LOCAL_MODULE_PATH := $(PRODUCT_OUT)/system/priv-app
+include $(BUILD_PACKAGE)
+		`,
+		expected: `
+android_app {
+	name: "foo",
+	privileged: true
+}
+`,
+	},
 }
 
 func TestEndToEnd(t *testing.T) {
diff --git a/androidmk/parser/make_strings.go b/androidmk/parser/make_strings.go
index aac4c4e..8030326 100644
--- a/androidmk/parser/make_strings.go
+++ b/androidmk/parser/make_strings.go
@@ -24,14 +24,24 @@
 // A MakeString is a string that may contain variable substitutions in it.
 // It can be considered as an alternating list of raw Strings and variable
 // substitutions, where the first and last entries in the list must be raw
-// Strings (possibly empty).  A MakeString that starts with a variable
-// will have an empty first raw string, and a MakeString that ends with a
-// variable will have an empty last raw string.  Two sequential Variables
-// will have an empty raw string between them.
+// Strings (possibly empty). The entirety of the text before the first variable,
+// between two variables, and after the last variable will be considered a
+// single String value. A MakeString that starts with a variable will have an
+// empty first raw string, and a MakeString that ends with a  variable will have
+// an empty last raw string.  Two sequential Variables will have an empty raw
+// string between them.
 //
 // The MakeString is stored as two lists, a list of raw Strings and a list
 // of Variables.  The raw string list is always one longer than the variable
 // list.
+//
+// For example, "$(FOO)/bar/baz" will be represented as the
+// following lists:
+//
+// {
+//   Strings: ["", "/bar/baz"],
+//   Variables: ["FOO"]
+// }
 type MakeString struct {
 	StringPos Pos
 	Strings   []string
diff --git a/apex/androidmk.go b/apex/androidmk.go
index 8785ca0..059b4d7 100644
--- a/apex/androidmk.go
+++ b/apex/androidmk.go
@@ -373,8 +373,10 @@
 				}
 				fmt.Fprintln(w, "LOCAL_MODULE_STEM :=", name+stemSuffix)
 				fmt.Fprintln(w, "LOCAL_UNINSTALLABLE_MODULE :=", !a.installable())
-				fmt.Fprintln(w, "LOCAL_SOONG_INSTALLED_MODULE :=", a.installedFile.String())
-				fmt.Fprintln(w, "LOCAL_SOONG_INSTALL_PAIRS :=", a.outputFile.String()+":"+a.installedFile.String())
+				if a.installable() {
+					fmt.Fprintln(w, "LOCAL_SOONG_INSTALLED_MODULE :=", a.installedFile.String())
+					fmt.Fprintln(w, "LOCAL_SOONG_INSTALL_PAIRS :=", a.outputFile.String()+":"+a.installedFile.String())
+				}
 
 				// Because apex writes .mk with Custom(), we need to write manually some common properties
 				// which are available via data.Entries
diff --git a/apex/apex.go b/apex/apex.go
index 9031a4e..ac67fee 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -1415,7 +1415,7 @@
 		for _, target := range ctx.MultiTargets() {
 			if target.Arch.ArchType.Multilib == "lib64" {
 				addDependenciesForNativeModules(ctx, ApexNativeDependencies{
-					Native_shared_libs: []string{"libclang_rt.hwasan-aarch64-android"},
+					Native_shared_libs: []string{"libclang_rt.hwasan"},
 					Tests:              nil,
 					Jni_libs:           nil,
 					Binaries:           nil,
diff --git a/apex/apex_test.go b/apex/apex_test.go
index 1c36c75..4f2a583 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -1415,13 +1415,14 @@
 		}
 
 		cc_prebuilt_library_shared {
-			name: "libclang_rt.hwasan-aarch64-android",
+			name: "libclang_rt.hwasan",
 			no_libcrt: true,
 			nocrt: true,
 			stl: "none",
 			system_shared_libs: [],
 			srcs: [""],
 			stubs: { versions: ["1"] },
+			stem: "libclang_rt.hwasan-aarch64-android",
 
 			sanitize: {
 				never: true,
@@ -1434,7 +1435,7 @@
 		"lib64/bionic/libclang_rt.hwasan-aarch64-android.so",
 	})
 
-	hwasan := ctx.ModuleForTests("libclang_rt.hwasan-aarch64-android", "android_arm64_armv8-a_shared")
+	hwasan := ctx.ModuleForTests("libclang_rt.hwasan", "android_arm64_armv8-a_shared")
 
 	installed := hwasan.Description("install libclang_rt.hwasan")
 	ensureContains(t, installed.Output.String(), "/system/lib64/bootstrap/libclang_rt.hwasan-aarch64-android.so")
@@ -1462,13 +1463,14 @@
 		}
 
 		cc_prebuilt_library_shared {
-			name: "libclang_rt.hwasan-aarch64-android",
+			name: "libclang_rt.hwasan",
 			no_libcrt: true,
 			nocrt: true,
 			stl: "none",
 			system_shared_libs: [],
 			srcs: [""],
 			stubs: { versions: ["1"] },
+			stem: "libclang_rt.hwasan-aarch64-android",
 
 			sanitize: {
 				never: true,
@@ -1482,7 +1484,7 @@
 		"lib64/bionic/libclang_rt.hwasan-aarch64-android.so",
 	})
 
-	hwasan := ctx.ModuleForTests("libclang_rt.hwasan-aarch64-android", "android_arm64_armv8-a_shared")
+	hwasan := ctx.ModuleForTests("libclang_rt.hwasan", "android_arm64_armv8-a_shared")
 
 	installed := hwasan.Description("install libclang_rt.hwasan")
 	ensureContains(t, installed.Output.String(), "/system/lib64/bootstrap/libclang_rt.hwasan-aarch64-android.so")
diff --git a/apex/builder.go b/apex/builder.go
index 183c215..8c5f99b 100644
--- a/apex/builder.go
+++ b/apex/builder.go
@@ -856,6 +856,10 @@
 		installSuffix = imageCapexSuffix
 	}
 
+	if !a.installable() {
+		a.SkipInstall()
+	}
+
 	// Install to $OUT/soong/{target,host}/.../apex.
 	a.installedFile = ctx.InstallFile(a.installDir, a.Name()+installSuffix, a.outputFile,
 		a.compatSymlinks.Paths()...)
diff --git a/bp2build/Android.bp b/bp2build/Android.bp
index b904c35..8a171d4 100644
--- a/bp2build/Android.bp
+++ b/bp2build/Android.bp
@@ -44,9 +44,16 @@
         "cc_library_shared_conversion_test.go",
         "cc_library_static_conversion_test.go",
         "cc_object_conversion_test.go",
+        "cc_prebuilt_library_shared_test.go",
         "conversion_test.go",
         "filegroup_conversion_test.go",
         "genrule_conversion_test.go",
+        "java_binary_host_conversion_test.go",
+        "java_import_conversion_test.go",
+        "java_library_conversion_test.go",
+        "java_library_host_conversion_test.go",
+        "java_plugin_conversion_test.go",
+        "java_proto_conversion_test.go",
         "performance_test.go",
         "prebuilt_etc_conversion_test.go",
         "python_binary_conversion_test.go",
diff --git a/bp2build/android_app_conversion_test.go b/bp2build/android_app_conversion_test.go
index 28de06c..b6095b2 100644
--- a/bp2build/android_app_conversion_test.go
+++ b/bp2build/android_app_conversion_test.go
@@ -51,6 +51,7 @@
 				"srcs":           `["app.java"]`,
 				"manifest":       `"AndroidManifest.xml"`,
 				"resource_files": `["res/res.png"]`,
+				"deps":           `["//prebuilts/sdk:public_current_android_sdk_java_import"]`,
 			}),
 		}})
 }
@@ -86,7 +87,49 @@
         "resb/res.png",
     ]`,
 				"custom_package": `"com.google"`,
-				"deps":           `[":static_lib_dep"]`,
+				"deps": `[
+        "//prebuilts/sdk:public_current_android_sdk_java_import",
+        ":static_lib_dep",
+    ]`,
+			}),
+		}})
+}
+
+func TestAndroidAppArchVariantSrcs(t *testing.T) {
+	runAndroidAppTestCase(t, bp2buildTestCase{
+		description:                "Android app - arch variant srcs",
+		moduleTypeUnderTest:        "android_app",
+		moduleTypeUnderTestFactory: java.AndroidAppFactory,
+		filesystem: map[string]string{
+			"arm.java":            "",
+			"x86.java":            "",
+			"res/res.png":         "",
+			"AndroidManifest.xml": "",
+		},
+		blueprint: `
+android_app {
+        name: "TestApp",
+        sdk_version: "current",
+        arch: {
+			arm: {
+				srcs: ["arm.java"],
+			},
+			x86: {
+				srcs: ["x86.java"],
+			}
+		}
+}
+`,
+		expectedBazelTargets: []string{
+			makeBazelTarget("android_binary", "TestApp", attrNameToString{
+				"srcs": `select({
+        "//build/bazel/platforms/arch:arm": ["arm.java"],
+        "//build/bazel/platforms/arch:x86": ["x86.java"],
+        "//conditions:default": [],
+    })`,
+				"manifest":       `"AndroidManifest.xml"`,
+				"resource_files": `["res/res.png"]`,
+				"deps":           `["//prebuilts/sdk:public_current_android_sdk_java_import"]`,
 			}),
 		}})
 }
diff --git a/bp2build/java_proto_conversion_test.go b/bp2build/java_proto_conversion_test.go
index 93b0677..61a398c 100644
--- a/bp2build/java_proto_conversion_test.go
+++ b/bp2build/java_proto_conversion_test.go
@@ -71,8 +71,7 @@
 }`
 
 	protoLibrary := makeBazelTarget("proto_library", "java-protos_proto", attrNameToString{
-		"srcs":                `["a.proto"]`,
-		"strip_import_prefix": `""`,
+		"srcs": `["a.proto"]`,
 	})
 
 	for _, tc := range testCases {
@@ -107,8 +106,7 @@
 `,
 		expectedBazelTargets: []string{
 			makeBazelTarget("proto_library", "java-protos_proto", attrNameToString{
-				"srcs":                `["a.proto"]`,
-				"strip_import_prefix": `""`,
+				"srcs": `["a.proto"]`,
 			}),
 			makeBazelTarget(
 				"java_lite_proto_library",
diff --git a/cc/binary.go b/cc/binary.go
index 0fe4490..9262f21 100644
--- a/cc/binary.go
+++ b/cc/binary.go
@@ -220,18 +220,18 @@
 func (binary *binaryDecorator) linkerInit(ctx BaseModuleContext) {
 	binary.baseLinker.linkerInit(ctx)
 
-	if !ctx.toolchain().Bionic() && !ctx.toolchain().Musl() {
-		if ctx.Os() == android.Linux {
-			// Unless explicitly specified otherwise, host static binaries are built with -static
-			// if HostStaticBinaries is true for the product configuration.
-			if binary.Properties.Static_executable == nil && ctx.Config().HostStaticBinaries() {
-				binary.Properties.Static_executable = BoolPtr(true)
-			}
-		} else {
-			// Static executables are not supported on Darwin or Windows
-			binary.Properties.Static_executable = nil
+	if ctx.Os().Linux() && ctx.Host() {
+		// Unless explicitly specified otherwise, host static binaries are built with -static
+		// if HostStaticBinaries is true for the product configuration.
+		if binary.Properties.Static_executable == nil && ctx.Config().HostStaticBinaries() {
+			binary.Properties.Static_executable = BoolPtr(true)
 		}
 	}
+
+	if ctx.Darwin() || ctx.Windows() {
+		// Static executables are not supported on Darwin or Windows
+		binary.Properties.Static_executable = nil
+	}
 }
 
 func (binary *binaryDecorator) static() bool {
diff --git a/cc/cc.go b/cc/cc.go
index a8adb0c..58ab28c 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -1383,7 +1383,7 @@
 }
 
 func InstallToBootstrap(name string, config android.Config) bool {
-	if name == "libclang_rt.hwasan-aarch64-android" {
+	if name == "libclang_rt.hwasan" {
 		return true
 	}
 	return isBionic(name)
diff --git a/cc/cc_test.go b/cc/cc_test.go
index 51a6a27..278efa1 100644
--- a/cc/cc_test.go
+++ b/cc/cc_test.go
@@ -2944,13 +2944,13 @@
 	// Check the shared version of lib2.
 	variant := "android_arm64_armv8-a_shared"
 	module := ctx.ModuleForTests("lib2", variant).Module().(*Module)
-	checkStaticLibs(t, []string{"lib1", "libc++demangle", "libclang_rt.builtins-aarch64-android"}, module)
+	checkStaticLibs(t, []string{"lib1", "libc++demangle", "libclang_rt.builtins"}, module)
 
 	// Check the static version of lib2.
 	variant = "android_arm64_armv8-a_static"
 	module = ctx.ModuleForTests("lib2", variant).Module().(*Module)
 	// libc++_static is linked additionally.
-	checkStaticLibs(t, []string{"lib1", "libc++_static", "libc++demangle", "libclang_rt.builtins-aarch64-android"}, module)
+	checkStaticLibs(t, []string{"lib1", "libc++_static", "libc++demangle", "libclang_rt.builtins"}, module)
 }
 
 var compilerFlagsTestCases = []struct {
diff --git a/cc/config/toolchain.go b/cc/config/toolchain.go
index 6cede11..7175fdc 100644
--- a/cc/config/toolchain.go
+++ b/cc/config/toolchain.go
@@ -227,14 +227,7 @@
 }
 
 func LibclangRuntimeLibrary(t Toolchain, library string) string {
-	arch := t.LibclangRuntimeLibraryArch()
-	if arch == "" {
-		return ""
-	}
-	if !t.Bionic() {
-		return "libclang_rt." + library + "-" + arch
-	}
-	return "libclang_rt." + library + "-" + arch + "-android"
+	return "libclang_rt." + library
 }
 
 func BuiltinsRuntimeLibrary(t Toolchain) string {
diff --git a/cc/coverage.go b/cc/coverage.go
index f2b5425..d0902ea 100644
--- a/cc/coverage.go
+++ b/cc/coverage.go
@@ -77,6 +77,10 @@
 	return deps
 }
 
+func EnableContinuousCoverage(ctx android.BaseModuleContext) bool {
+	return ctx.DeviceConfig().ClangCoverageContinuousMode()
+}
+
 func (cov *coverage) flags(ctx ModuleContext, flags Flags, deps PathDeps) (Flags, PathDeps) {
 	clangCoverage := ctx.DeviceConfig().ClangCoverageEnabled()
 	gcovCoverage := ctx.DeviceConfig().GcovCoverageEnabled()
@@ -101,6 +105,9 @@
 			// Override -Wframe-larger-than.  We can expect frame size increase after
 			// coverage instrumentation.
 			flags.Local.CFlags = append(flags.Local.CFlags, "-Wno-frame-larger-than=")
+			if EnableContinuousCoverage(ctx) {
+				flags.Local.CommonFlags = append(flags.Local.CommonFlags, "-mllvm", "-runtime-counter-relocation")
+			}
 		}
 	}
 
@@ -152,6 +159,9 @@
 			flags.Local.LdFlags = append(flags.Local.LdFlags, "-Wl,--wrap,getenv")
 		} else if clangCoverage {
 			flags.Local.LdFlags = append(flags.Local.LdFlags, profileInstrFlag)
+			if EnableContinuousCoverage(ctx) {
+				flags.Local.LdFlags = append(flags.Local.LdFlags, "-Wl,-mllvm=-runtime-counter-relocation")
+			}
 
 			coverage := ctx.GetDirectDepWithTag(getClangProfileLibraryName(ctx), CoverageDepTag).(*Module)
 			deps.WholeStaticLibs = append(deps.WholeStaticLibs, coverage.OutputFile().Path())
diff --git a/cc/sanitize_test.go b/cc/sanitize_test.go
index 0070e40..c1ca034 100644
--- a/cc/sanitize_test.go
+++ b/cc/sanitize_test.go
@@ -24,11 +24,7 @@
 
 var prepareForAsanTest = android.FixtureAddFile("asan/Android.bp", []byte(`
 	cc_library_shared {
-		name: "libclang_rt.asan-aarch64-android",
-	}
-
-	cc_library_shared {
-		name: "libclang_rt.asan-arm-android",
+		name: "libclang_rt.asan",
 	}
 `))
 
diff --git a/cc/testing.go b/cc/testing.go
index a03d147..32f7c60 100644
--- a/cc/testing.go
+++ b/cc/testing.go
@@ -86,54 +86,20 @@
 		}
 
 		cc_prebuilt_library_static {
-			name: "libclang_rt.builtins-arm-android",
-			defaults: ["toolchain_libs_defaults"],
-			native_bridge_supported: true,
-			vendor_ramdisk_available: true,
-		}
-
-		cc_prebuilt_library_static {
-			name: "libclang_rt.builtins-aarch64-android",
-			defaults: ["toolchain_libs_defaults"],
-			native_bridge_supported: true,
-			vendor_ramdisk_available: true,
-		}
-
-		cc_prebuilt_library_static {
-			name: "libclang_rt.builtins-x86_64",
+			name: "libclang_rt.builtins",
 			defaults: ["toolchain_libs_defaults"],
 			host_supported: true,
-		}
-
-		cc_prebuilt_library_static {
-			name: "libclang_rt.builtins-i386",
-			defaults: ["toolchain_libs_defaults"],
-			host_supported: true,
+	        vendor_available: true,
+			vendor_ramdisk_available: true,
+			native_bridge_supported: true,
 		}
 
 		cc_prebuilt_library_shared {
-			name: "libclang_rt.hwasan-aarch64-android",
+			name: "libclang_rt.hwasan",
 			defaults: ["toolchain_libs_defaults"],
 		}
 
 		cc_prebuilt_library_static {
-			name: "libclang_rt.builtins-i686-android",
-			defaults: ["toolchain_libs_defaults"],
-			vendor_ramdisk_available: true,
-			native_bridge_supported: true,
-		}
-
-		cc_prebuilt_library_static {
-			name: "libclang_rt.builtins-x86_64-android",
-			defaults: [
-				"linux_bionic_supported",
-				"toolchain_libs_defaults",
-			],
-			native_bridge_supported: true,
-			vendor_ramdisk_available: true,
-		}
-
-		cc_prebuilt_library_static {
 			name: "libunwind",
 			defaults: [
 				"linux_bionic_supported",
@@ -144,30 +110,7 @@
 		}
 
 		cc_prebuilt_library_static {
-			name: "libclang_rt.fuzzer-arm-android",
-			defaults: ["toolchain_libs_defaults"],
-		}
-
-		cc_prebuilt_library_static {
-			name: "libclang_rt.fuzzer-aarch64-android",
-			defaults: ["toolchain_libs_defaults"],
-		}
-
-		cc_prebuilt_library_static {
-			name: "libclang_rt.fuzzer-i686-android",
-			defaults: ["toolchain_libs_defaults"],
-		}
-
-		cc_prebuilt_library_static {
-			name: "libclang_rt.fuzzer-x86_64-android",
-			defaults: [
-				"linux_bionic_supported",
-				"toolchain_libs_defaults",
-			],
-		}
-
-		cc_prebuilt_library_static {
-			name: "libclang_rt.fuzzer-x86_64",
+			name: "libclang_rt.fuzzer",
 			defaults: [
 				"linux_bionic_supported",
 				"toolchain_libs_defaults",
@@ -176,17 +119,12 @@
 
 		// Needed for sanitizer
 		cc_prebuilt_library_shared {
-			name: "libclang_rt.ubsan_standalone-aarch64-android",
+			name: "libclang_rt.ubsan_standalone",
 			defaults: ["toolchain_libs_defaults"],
 		}
 
 		cc_prebuilt_library_static {
-			name: "libclang_rt.ubsan_minimal-aarch64-android",
-			defaults: ["toolchain_libs_defaults"],
-		}
-
-		cc_prebuilt_library_static {
-			name: "libclang_rt.ubsan_minimal-arm-android",
+			name: "libclang_rt.ubsan_minimal",
 			defaults: ["toolchain_libs_defaults"],
 		}
 
diff --git a/cc/vendor_snapshot.go b/cc/vendor_snapshot.go
index 8a17e2e..e7c05ac 100644
--- a/cc/vendor_snapshot.go
+++ b/cc/vendor_snapshot.go
@@ -146,6 +146,7 @@
 	// binary flags
 	Symlinks         []string `json:",omitempty"`
 	StaticExecutable bool     `json:",omitempty"`
+	InstallInRoot    bool     `json:",omitempty"`
 
 	// dependencies
 	SharedLibs  []string `json:",omitempty"`
@@ -320,6 +321,7 @@
 			// binary flags
 			prop.Symlinks = m.Symlinks()
 			prop.StaticExecutable = m.StaticExecutable()
+			prop.InstallInRoot = m.InstallInRoot()
 			prop.SharedLibs = m.SnapshotSharedLibs()
 			// static libs dependencies are required to collect the NOTICE files.
 			prop.StaticLibs = m.SnapshotStaticLibs()
diff --git a/cc/vndk.go b/cc/vndk.go
index c9c9f2c..bf6148b 100644
--- a/cc/vndk.go
+++ b/cc/vndk.go
@@ -450,7 +450,7 @@
 // Therefore, by removing the library here, we cause it to only be installed if libc
 // depends on it.
 func llndkLibrariesTxtFactory() android.SingletonModule {
-	return newVndkLibrariesWithMakeVarFilter(llndkLibraries, "LLNDK_LIBRARIES", "libclang_rt.hwasan-")
+	return newVndkLibrariesWithMakeVarFilter(llndkLibraries, "LLNDK_LIBRARIES", "libclang_rt.hwasan")
 }
 
 // vndksp_libraries_txt is a singleton module whose content is a list of VNDKSP libraries
diff --git a/dexpreopt/DEXPREOPT_IMPLEMENTATION.md b/dexpreopt/DEXPREOPT_IMPLEMENTATION.md
new file mode 100644
index 0000000..c3a1730
--- /dev/null
+++ b/dexpreopt/DEXPREOPT_IMPLEMENTATION.md
@@ -0,0 +1,258 @@
+## Dexpreopt implementation
+
+### Introduction
+
+All dexpreopted Java code falls into three categories:
+
+- bootclasspath
+- system server
+- apps and libraries
+
+Dexpreopt implementation for bootclasspath libraries (boot images) is located in
+[soong/java] (see e.g. [soong/java/dexpreopt_bootjars.go]), and install rules
+are in [make/core/dex_preopt.mk].
+
+Dexpreopt implementation for system server, libraries and apps is located in
+[soong/dexpreopt]. For the rest of this section we focus primarily on it (and
+not boot images).
+
+Dexpeopt implementation is split across the Soong part and the Make part. The
+core logic is in Soong, and Make only generates configs and scripts to pass
+information to Soong.
+
+### Global and module dexpreopt.config
+
+The build system generates a global JSON dexpreopt config that is populated from
+product variables. This is static configuration that is passed to both Soong and
+Make. The `$OUT/soong/dexpreopt.config` file is generated in
+[make/core/dex_preopt_config.mk]. Soong reads it in [soong/dexpreopt/config.go]
+and makes a device-specific copy (this is needed to ensure incremental build
+correctness). The global config contains lists of bootclasspath jars, system
+server jars, dex2oat options, global switches that enable and disable parts of
+dexpreopt and so on.
+
+The build system also generates a module config for each dexpreopted package. It
+contains package-specific configuration that is derived from the global
+configuration and Android.bp or Android.mk module for the package.
+
+Module configs for Make packages are generated in
+[make/core/dex_preopt_odex_install.mk]; they are materialized as per-package
+JSON dexpreopt.config files.
+
+Module configs in Soong are not materialized as dexpreopt.config files and exist
+as Go structures in memory, unless it is necessary to materialize them as a file
+for dependent Make packages or for post-dexpreopting. Module configs are defined
+in [soong/dexpreopt/config.go].
+
+### Dexpreopt in Soong
+
+The Soong implementation of dexpreopt consists roughly of the following steps:
+
+- Read global dexpreopt config passed from Make ([soong/dexpreopt/config.go]).
+
+- Construct a static boot image config ([soong/java/dexpreopt_config.go]).
+
+- During dependency mutator pass, for each suitable module:
+    - add uses-library dependencies (e.g. for apps: [soong/java/app.go:deps])
+
+- During rule generation pass, for each suitable module:
+    - compute transitive uses-library dependency closure
+      ([soong/java/java.go:addCLCFromDep])
+
+    - construct CLC from the dependency closure
+      ([soong/dexpreopt/class_loader_context.go])
+
+    - construct module config with CLC, boot image locations, etc.
+      ([soong/java/dexpreopt.go])
+
+    - generate build rules to verify build-time CLC against the manifest (e.g.
+      for apps: [soong/java/app.go:verifyUsesLibraries])
+
+    - generate dexpreopt build rule ([soong/dexpreopt/dexpreopt.go])
+
+- At the end of rule generation pass:
+    - generate build rules for boot images ([soong/java/dexpreopt_bootjars.go],
+      [soong/java/bootclasspath_fragment.go] and
+      [soong/java/platform_bootclasspath.go])
+
+### Dexpreopt in Make - dexpreopt_gen
+
+In order to reuse the same dexpreopt implementation for both Soong and Make
+packages, part of Soong is compiled into a standalone binary dexpreopt_gen. It
+runs during the Ninja stage of the build and generates shell scripts with
+dexpreopt build rules for Make packages, and then executes them.
+
+This setup causes many inconveniences. To name a few:
+
+- Errors in the build rules are only revealed at the late stage of the build.
+
+- These rules are not tested by the presubmit builds that run `m nothing` on
+  many build targets/products.
+
+- It is impossible to find dexpreopt build rules in the generated Ninja files.
+
+However all these issues are a lesser evil compared to having a duplicate
+dexpreopt implementation in Make. Also note that it would be problematic to
+reimplement the logic in Make anyway, because Android.mk modules are not
+processed in the order of uses-library dependencies and propagating dependency
+information from one module to another would require a similar workaround with
+a script.
+
+Dexpreopt for Make packages involves a few steps:
+
+- At Soong phase (during `m nothing`), see dexpreopt_gen:
+    - generate build rules for dexpreopt_gen binary
+
+- At Make/Kati phase (during `m nothing`), see
+  [make/core/dex_preopt_odex_install.mk]:
+    - generate build rules for module dexpreopt.config
+
+    - generate build rules for merging dependency dexpreopt.config files (see
+      [make/core/dex_preopt_config_merger.py])
+
+    - generate build rules for dexpreopt_gen invocation
+
+    - generate build rules for executing dexpreopt.sh scripts
+
+- At Ninja phase (during `m`):
+    - generate dexpreopt.config files
+
+    - execute dexpreopt_gen rules (generate dexpreopt.sh scripts)
+
+    - execute dexpreopt.sh scripts (this runs the actual dexpreopt)
+
+The Make/Kati phase adds all the necessary dependencies that trigger
+dexpreopt_gen and dexpreopt.sh rules. The real dexpreopt command (dex2oat
+invocation that will be executed to AOT-compile a package) is in the
+dexpreopt.sh script, which is generated close to the end of the build.
+
+### Indirect build rules
+
+The process described above for Make packages involves "indirect build rules",
+i.e. build rules that are generated not at the time when the build system is
+created (which is a small step at the very beginning of the build triggered with
+`m nothing`), but at the time when the actual build is done (`m` phase).
+
+Some build systems, such as Make, allow modifications of the build graph during
+the build. Other build systems, such as Soong, have a clear separation into the
+first "generation phase" (this is when build rules are created) and the second
+"build phase" (this is when the build rules are executed), and they do not allow
+modifications of the dependency graph during the second phase. The Soong
+approach is better from performance standpoint, because with the Make approach
+there are no guarantees regarding the time of the build --- recursive build
+graph modfications continue until fixpoint. However the Soong approach is also
+more restictive, as it can only generate build rules from the information that
+is passed to the build system via global configuration, Android.bp files or
+encoded in the Go code. Any other information (such as the contents of the Java
+manifest files) are not accessible and cannot be used to generate build rules.
+
+Hence the need for the "indirect build rules": during the generation phase only
+stubs of the build rules are generated, and the real rules are generated by the
+stub rules during the build phase (and executed immediately). Note that the
+build system still has to add all the necessary dependencies during the
+generation phase, because it will not be possible to change build order during
+the build phase.
+
+Indirect buils rules are used in a couple of places in dexpreopt:
+
+- [soong/scripts/manifest_check.py]: first to extract targetSdkVersion from the
+  manifest, and later to extract `<uses-library/>` tags from the manifest and
+  compare them to the uses-library list known to the build system
+
+- [soong/scripts/construct_context.py]: to trim compatibility libraries in CLC
+
+- [make/core/dex_preopt_config_merger.py]: to merge information from
+  dexpreopt.config files for uses-library dependencies into the dependent's
+  dexpreopt.config file (mostly the CLC)
+
+- autogenerated dexpreopt.sh scripts: to call dexpreopt_gen
+
+### Consistency check - manifest_check.py
+
+Because the information from the manifests has to be duplicated in the
+Android.bp/Android.mk files, there is a danger that it may get out of sync. To
+guard against that, the build system generates a rule that verifies
+uses-libraries: checks the metadata in the build files against the contents of a
+manifest. The manifest can be available as a source file, or as part of a
+prebuilt APK.
+
+The check is implemented in [soong/scripts/manifest_check.py].
+
+It is possible to turn off the check globally for a product by setting
+`PRODUCT_BROKEN_VERIFY_USES_LIBRARIES := true` in a product makefile, or for a
+particular build by setting `RELAX_USES_LIBRARY_CHECK=true`.
+
+### Compatibility libraries - construct_context.py
+
+Compatibility libraries are libraries that didn’t exist prior to a certain SDK
+version (say, `N`), but classes in them were in the bootclasspath jars, etc.,
+and in version `N` they have been separated into a standalone uses-library.
+Compatibility libraries should only be in the CLC of an app if its
+`targetSdkVersion` in the manifest is less than `N`.
+
+Currently compatibility libraries only affect apps (but not other libraries).
+
+The build system cannot see `targetSdkVersion` of an app at the time it
+generates dexpreopt build rules, so it doesn't know whether to add compatibility
+libaries to CLC or not. As a workaround, the build system includes all
+compatibility libraries regardless of the app version, and appends some extra
+logic to the dexpreopt rule that will extract `targetSdkVersion` from the
+manifest and filter CLC based on that version during Ninja stage of the build,
+immediately before executing the dexpreopt command (see the
+soong/scripts/construct_context.py script).
+
+As of the time of writing (January 2022), there are the following compatibility
+libraries:
+
+- org.apache.http.legacy (SDK 28)
+- android.hidl.base-V1.0-java (SDK 29)
+- android.hidl.manager-V1.0-java (SDK 29)
+- android.test.base (SDK 30)
+- android.test.mock (SDK 30)
+
+### Manifest fixer
+
+Sometimes uses-library tags are missing from the source manifest of a
+library/app. This may happen for example if one of the transitive dependencies
+of the library/app starts using another uses-library, and the library/app's
+manifest isn't updated to include it.
+
+Soong can compute some of the missing uses-library tags for a given library/app
+automatically as SDK libraries in the transitive dependency closure of the
+library/app. The closure is needed because a library/app may depend on a static
+library that may in turn depend on an SDK library (possibly transitively via
+another library).
+
+Not all uses-library tags can be computed in this way, because some of the
+uses-library dependencies are not SDK libraries, or they are not reachable via
+transitive dependency closure. But when possible, allowing Soong to calculate
+the manifest entries is less prone to errors and simplifies maintenance. For
+example, consider a situation when many apps use some static library that adds a
+new uses-library dependency -- all the apps will have to be updated. That is
+difficult to maintain.
+
+There is also a manifest merger, because sometimes the final manifest of an app
+is merged from a few dependency manifests, so the final manifest installed on
+devices contains a superset of uses-library tags of the source manifest of the
+app.
+
+
+[make/core/dex_preopt.mk]: https://cs.android.com/android/platform/superproject/+/master:build/make/core/dex_preopt.mk
+[make/core/dex_preopt_config.mk]: https://cs.android.com/android/platform/superproject/+/master:build/make/core/dex_preopt_config.mk
+[make/core/dex_preopt_config_merger.py]: https://cs.android.com/android/platform/superproject/+/master:build/make/core/dex_preopt_config_merger.py
+[make/core/dex_preopt_odex_install.mk]: https://cs.android.com/android/platform/superproject/+/master:build/make/core/dex_preopt_odex_install.mk
+[soong/dexpreopt]: https://cs.android.com/android/platform/superproject/+/master:build/soong/dexpreopt
+[soong/dexpreopt/class_loader_context.go]: https://cs.android.com/android/platform/superproject/+/master:build/soong/dexpreopt/class_loader_context.go
+[soong/dexpreopt/config.go]: https://cs.android.com/android/platform/superproject/+/master:build/soong/dexpreopt/config.go
+[soong/dexpreopt/dexpreopt.go]: https://cs.android.com/android/platform/superproject/+/master:build/soong/dexpreopt/dexpreopt.go
+[soong/java]: https://cs.android.com/android/platform/superproject/+/master:build/soong/java
+[soong/java/app.go:deps]: https://cs.android.com/android/platform/superproject/+/master:build/soong/java/app.go?q=%22func%20\(u%20*usesLibrary\)%20deps%22
+[soong/java/app.go:verifyUsesLibraries]: https://cs.android.com/android/platform/superproject/+/master:build/soong/java/app.go?q=%22func%20\(u%20*usesLibrary\)%20verifyUsesLibraries%22
+[soong/java/bootclasspath_fragment.go]: https://cs.android.com/android/platform/superproject/+/master:build/soong/java/bootclasspath_fragment.go
+[soong/java/dexpreopt.go]: https://cs.android.com/android/platform/superproject/+/master:build/soong/java/dexpreopt.go
+[soong/java/dexpreopt_bootjars.go]: https://cs.android.com/android/platform/superproject/+/master:build/soong/java/dexpreopt_bootjars.go
+[soong/java/dexpreopt_config.go]: https://cs.android.com/android/platform/superproject/+/master:build/soong/java/dexpreopt_config.go
+[soong/java/java.go:addCLCFromDep]: https://cs.android.com/android/platform/superproject/+/master:build/soong/java/java.go?q=%22func%20addCLCfromDep%22
+[soong/java/platform_bootclasspath.go]: https://cs.android.com/android/platform/superproject/+/master:build/soong/java/platform_bootclasspath.go
+[soong/scripts/construct_context.py]: https://cs.android.com/android/platform/superproject/+/master:build/soong/scripts/construct_context.py
+[soong/scripts/manifest_check.py]: https://cs.android.com/android/platform/superproject/+/master:build/soong/scripts/manifest_check.py
diff --git a/docs/rbe.json b/docs/rbe.json
new file mode 100644
index 0000000..f6ff107
--- /dev/null
+++ b/docs/rbe.json
@@ -0,0 +1,24 @@
+{
+    "env": {
+        "USE_RBE": "1",
+
+        "RBE_R8_EXEC_STRATEGY": "remote_local_fallback",
+        "RBE_CXX_EXEC_STRATEGY": "remote_local_fallback",
+        "RBE_D8_EXEC_STRATEGY": "remote_local_fallback",
+        "RBE_JAVAC_EXEC_STRATEGY": "remote_local_fallback",
+        "RBE_JAVAC": "1",
+        "RBE_R8": "1",
+        "RBE_D8": "1",
+
+        "RBE_instance": "[replace with your RBE instance]",
+        "RBE_service": "[replace with your RBE service endpoint]",
+
+        "RBE_DIR": "prebuilts/remoteexecution-client/live",
+
+        "RBE_use_application_default_credentials": "true",
+
+        "RBE_log_dir": "/tmp",
+        "RBE_output_dir": "/tmp",
+        "RBE_proxy_log_dir": "/tmp"
+    }
+}
diff --git a/docs/rbe.md b/docs/rbe.md
new file mode 100644
index 0000000..cfe86d7
--- /dev/null
+++ b/docs/rbe.md
@@ -0,0 +1,70 @@
+# Build Android Platform on Remote Build Execution
+
+Soong is integrated with Google's Remote Build Execution(RBE) service, which
+implements the
+[Remote Executaion API](https://github.com/bazelbuild/remote-apis).
+
+With RBE enabled, it can speed up the Android Platform builds by distributing
+build actions through a worker pool sharing a central cache of build results.
+
+## Configuration
+
+To enable RBE, you need to set several environment variables before triggering
+the build. You can set them through a
+[environment variables config file](https://android.googlesource.com/platform/build/soong/+/master/README.md#environment-variables-config-file).
+As an example, [build/soong/docs/rbe.json](rbe.json) is a config that enables
+RBE in the build. Once the config file is created, you need to let Soong load
+the config file by specifying `ANDROID_BUILD_ENVIRONMENT_CONFIG_DIR` environment
+variable and `ANDROID_BUILD_ENVIRONMENT_CONFIG` environment variable. The
+following command starts Soong with [build/soong/docs/rbe.json](rbe.json)
+loaded:
+
+```shell
+ANDROID_BUILD_ENVIRONMENT_CONFIG=rbe \
+ANDROID_BUILD_ENVIRONMENT_CONFIG_DIR=build/soong/doc \
+  build/soong/soong_ui.bash
+```
+
+### Configuration Explanation
+
+Below a brief explanation of each field in
+[build/soong/docs/rbe.json](rbe.json):
+
+##### USE\_RBE:
+If set to 1, enable RBE for the build.
+
+##### RBE\_CXX\_EXEC\_STRATEGY / RBE\_JAVAC\_EXEC\_STRATEGY / RBE\_R8\_EXEC\_STRATEGY / RBE\_D8\_EXEC\_STRATEGY:
+
+Sets strategies for C++/javac/r8/d8 action types. Available options are
+(**Note**: all options will update the remote cache if the right permissions to
+update cache are given to the user.):
+
+*   **local**: Only execute locally.
+*   **remote**: Only execute remotely.
+*   **remote_local_fallback**: Try executing remotely and fall back to local
+    execution if failed.
+*   **racing**: Race remote execution and local execution and use the earlier
+    result.
+
+##### RBE\_JAVAC / RBE\_R8 / RBE\_D8
+
+If set to 1, enable javac/r8/d8 support. C++ compilation is enabled by default.
+
+##### RBE\_service / RBE\_instance
+
+The remote execution service endpoint and instance ID to target when calling
+remote execution via gRPC to execute actions.
+
+##### RBE\_DIR
+
+Where to find remote client binaries (rewrapper, reproxy)
+
+##### RBE\_use\_application\_default\_credentials
+
+reclient uses
+[application default credentials](https://cloud.google.com/sdk/gcloud/reference/auth/application-default/login)
+for autentication, as generated by `gcloud auth application-default login`
+
+##### RBE\_log\_dir/RBE\_proxy\_log\_dir/RBE\_output\_dir
+
+Logs generated by rewrapper and reproxy will go here.
diff --git a/java/base.go b/java/base.go
index 8747039..9978a66 100644
--- a/java/base.go
+++ b/java/base.go
@@ -481,6 +481,8 @@
 	sdkVersion    android.SdkSpec
 	minSdkVersion android.SdkSpec
 	maxSdkVersion android.SdkSpec
+
+	sourceExtensions []string
 }
 
 func (j *Module) CheckStableSdkVersion(ctx android.BaseModuleContext) error {
@@ -982,6 +984,14 @@
 	return flags
 }
 
+func (j *Module) AddJSONData(d *map[string]interface{}) {
+	(&j.ModuleBase).AddJSONData(d)
+	(*d)["Java"] = map[string]interface{}{
+		"SourceExtensions": j.sourceExtensions,
+	}
+
+}
+
 func (j *Module) compile(ctx android.ModuleContext, aaptSrcJar android.Path) {
 	j.exportAidlIncludeDirs = android.PathsForModuleSrc(ctx, j.deviceProperties.Aidl.Export_include_dirs)
 
@@ -993,6 +1003,12 @@
 	}
 
 	srcFiles := android.PathsForModuleSrcExcludes(ctx, j.properties.Srcs, j.properties.Exclude_srcs)
+	j.sourceExtensions = []string{}
+	for _, ext := range []string{".kt", ".proto", ".aidl", ".java", ".logtags"} {
+		if hasSrcExt(srcFiles.Strings(), ext) {
+			j.sourceExtensions = append(j.sourceExtensions, ext)
+		}
+	}
 	if hasSrcExt(srcFiles.Strings(), ".proto") {
 		flags = protoFlags(ctx, &j.properties, &j.protoProperties, flags)
 	}
diff --git a/java/bootclasspath_fragment.go b/java/bootclasspath_fragment.go
index 5fe409e..c3a5d5f 100644
--- a/java/bootclasspath_fragment.go
+++ b/java/bootclasspath_fragment.go
@@ -16,6 +16,7 @@
 
 import (
 	"fmt"
+	"io"
 	"path/filepath"
 	"reflect"
 	"strings"
@@ -139,7 +140,7 @@
 	BootclasspathFragmentsDepsProperties
 }
 
-type SourceOnlyBootclasspathProperties struct {
+type HiddenApiPackageProperties struct {
 	Hidden_api struct {
 		// Contains prefixes of a package hierarchy that is provided solely by this
 		// bootclasspath_fragment.
@@ -148,6 +149,14 @@
 		// hidden API flags. See split_packages property for more details.
 		Package_prefixes []string
 
+		// A list of individual packages that are provided solely by this
+		// bootclasspath_fragment but which cannot be listed in package_prefixes
+		// because there are sub-packages which are provided by other modules.
+		//
+		// This should only be used for legacy packages. New packages should be
+		// covered by a package prefix.
+		Single_packages []string
+
 		// The list of split packages provided by this bootclasspath_fragment.
 		//
 		// A split package is one that contains classes which are provided by multiple
@@ -207,6 +216,11 @@
 	}
 }
 
+type SourceOnlyBootclasspathProperties struct {
+	HiddenApiPackageProperties
+	Coverage HiddenApiPackageProperties
+}
+
 type BootclasspathFragmentModule struct {
 	android.ModuleBase
 	android.ApexModuleBase
@@ -270,6 +284,12 @@
 				ctx.PropertyErrorf("coverage", "error trying to append coverage specific properties: %s", err)
 				return
 			}
+
+			err = proptools.AppendProperties(&m.sourceOnlyProperties.HiddenApiPackageProperties, &m.sourceOnlyProperties.Coverage, nil)
+			if err != nil {
+				ctx.PropertyErrorf("coverage", "error trying to append hidden api coverage specific properties: %s", err)
+				return
+			}
 		}
 
 		// Initialize the contents property from the image_name.
@@ -588,6 +608,19 @@
 			// Provide the apex content info.
 			b.provideApexContentInfo(ctx, imageConfig, hiddenAPIOutput, bootImageFilesByArch)
 		}
+	} else {
+		// Versioned fragments are not needed by make.
+		b.HideFromMake()
+	}
+
+	// In order for information about bootclasspath_fragment modules to be added to module-info.json
+	// it is necessary to output an entry to Make. As bootclasspath_fragment modules are part of an
+	// APEX there can be multiple variants, including the default/platform variant and only one can
+	// be output to Make but it does not really matter which variant is output. The default/platform
+	// variant is the first (ctx.PrimaryModule()) and is usually hidden from make so this just picks
+	// the last variant (ctx.FinalModule()).
+	if ctx.Module() != ctx.FinalModule() {
+		b.HideFromMake()
 	}
 }
 
@@ -717,7 +750,8 @@
 	// TODO(b/192868581): Remove once the source and prebuilts provide a signature patterns file of
 	//  their own.
 	if output.SignaturePatternsPath == nil {
-		output.SignaturePatternsPath = buildRuleSignaturePatternsFile(ctx, output.AllFlagsPath, []string{"*"}, nil)
+		output.SignaturePatternsPath = buildRuleSignaturePatternsFile(
+			ctx, output.AllFlagsPath, []string{"*"}, nil, nil)
 	}
 
 	// Initialize a HiddenAPIInfo structure.
@@ -792,11 +826,13 @@
 	// signature patterns.
 	splitPackages := b.sourceOnlyProperties.Hidden_api.Split_packages
 	packagePrefixes := b.sourceOnlyProperties.Hidden_api.Package_prefixes
-	if splitPackages != nil || packagePrefixes != nil {
+	singlePackages := b.sourceOnlyProperties.Hidden_api.Single_packages
+	if splitPackages != nil || packagePrefixes != nil || singlePackages != nil {
 		if splitPackages == nil {
 			splitPackages = []string{"*"}
 		}
-		output.SignaturePatternsPath = buildRuleSignaturePatternsFile(ctx, output.AllFlagsPath, splitPackages, packagePrefixes)
+		output.SignaturePatternsPath = buildRuleSignaturePatternsFile(
+			ctx, output.AllFlagsPath, splitPackages, packagePrefixes, singlePackages)
 	}
 
 	return output
@@ -849,7 +885,22 @@
 }
 
 func (b *BootclasspathFragmentModule) AndroidMkEntries() []android.AndroidMkEntries {
-	var entriesList []android.AndroidMkEntries
+	// Use the generated classpath proto as the output.
+	outputFile := b.outputFilepath
+	// Create a fake entry that will cause this to be added to the module-info.json file.
+	entriesList := []android.AndroidMkEntries{{
+		Class:      "FAKE",
+		OutputFile: android.OptionalPathForPath(outputFile),
+		Include:    "$(BUILD_PHONY_PACKAGE)",
+		ExtraFooters: []android.AndroidMkExtraFootersFunc{
+			func(w io.Writer, name, prefix, moduleDir string) {
+				// Allow the bootclasspath_fragment to be built by simply passing its name on the command
+				// line.
+				fmt.Fprintln(w, ".PHONY:", b.Name())
+				fmt.Fprintln(w, b.Name()+":", outputFile.String())
+			},
+		},
+	}}
 	for _, install := range b.bootImageDeviceInstalls {
 		entriesList = append(entriesList, install.ToMakeEntries())
 	}
diff --git a/java/config/config.go b/java/config/config.go
index 39584cb..05dfde6 100644
--- a/java/config/config.go
+++ b/java/config/config.go
@@ -105,7 +105,12 @@
 		if override := ctx.Config().Getenv("OVERRIDE_JLINK_VERSION_NUMBER"); override != "" {
 			return override
 		}
-		return "11"
+		switch ctx.Config().Getenv("EXPERIMENTAL_USE_OPENJDK17_TOOLCHAIN") {
+		case "true":
+			return "17"
+		default:
+			return "11"
+		}
 	})
 
 	pctx.SourcePathVariable("JavaToolchain", "${JavaHome}/bin")
diff --git a/java/dexpreopt_bootjars.go b/java/dexpreopt_bootjars.go
index cad9c33..3d91aec 100644
--- a/java/dexpreopt_bootjars.go
+++ b/java/dexpreopt_bootjars.go
@@ -276,11 +276,17 @@
 	// Rules which should be used in make to install the outputs.
 	profileInstalls android.RuleBuilderInstalls
 
+	// Path to the license metadata file for the module that built the profile.
+	profileLicenseMetadataFile android.OptionalPath
+
 	// Path to the image profile file on host (or empty, if profile is not generated).
 	profilePathOnHost android.Path
 
 	// Target-dependent fields.
 	variants []*bootImageVariant
+
+	// Path of the preloaded classes file.
+	preloadedClassesFile string
 }
 
 // Target-dependent description of a boot image.
@@ -320,6 +326,9 @@
 
 	// Rules which should be used in make to install the outputs on device.
 	deviceInstalls android.RuleBuilderInstalls
+
+	// Path to the license metadata file for the module that built the image.
+	licenseMetadataFile android.OptionalPath
 }
 
 // Get target-specific boot image variant for the given boot image config and target.
@@ -680,6 +689,13 @@
 		cmd.FlagWithArg("--base=", ctx.Config().LibartImgDeviceBaseAddress())
 	}
 
+	// We always expect a preloaded classes file to be available. However, if we cannot find it, it's
+	// OK to not pass the flag to dex2oat.
+	preloadedClassesPath := android.ExistentPathForSource(ctx, image.preloadedClassesFile)
+	if preloadedClassesPath.Valid() {
+		cmd.FlagWithInput("--preloaded-classes=", preloadedClassesPath.Path())
+	}
+
 	cmd.
 		FlagForEachInput("--dex-file=", image.dexPaths.Paths()).
 		FlagForEachArg("--dex-location=", image.dexLocations).
@@ -759,6 +775,7 @@
 	image.vdexInstalls = vdexInstalls
 	image.unstrippedInstalls = unstrippedInstalls
 	image.deviceInstalls = deviceInstalls
+	image.licenseMetadataFile = android.OptionalPathForPath(ctx.LicenseMetadataFile())
 }
 
 const failureMessage = `ERROR: Dex2oat failed to compile a boot image.
@@ -807,6 +824,7 @@
 	if image == defaultBootImageConfig(ctx) {
 		rule.Install(profile, "/system/etc/boot-image.prof")
 		image.profileInstalls = append(image.profileInstalls, rule.Installs()...)
+		image.profileLicenseMetadataFile = android.OptionalPathForPath(ctx.LicenseMetadataFile())
 	}
 
 	rule.Build("bootJarsProfile", "profile boot jars")
@@ -844,6 +862,7 @@
 	rule.Install(profile, "/system/etc/boot-image.bprof")
 	rule.Build("bootFrameworkProfile", "profile boot framework jars")
 	image.profileInstalls = append(image.profileInstalls, rule.Installs()...)
+	image.profileLicenseMetadataFile = android.OptionalPathForPath(ctx.LicenseMetadataFile())
 
 	return profile
 }
@@ -909,6 +928,9 @@
 	image := d.defaultBootImage
 	if image != nil {
 		ctx.Strict("DEXPREOPT_IMAGE_PROFILE_BUILT_INSTALLED", image.profileInstalls.String())
+		if image.profileLicenseMetadataFile.Valid() {
+			ctx.Strict("DEXPREOPT_IMAGE_PROFILE_LICENSE_METADATA", image.profileLicenseMetadataFile.String())
+		}
 
 		global := dexpreopt.GetGlobalConfig(ctx)
 		dexPaths, dexLocations := bcpForDexpreopt(ctx, global.PreoptWithUpdatableBcp)
@@ -934,6 +956,9 @@
 				ctx.Strict("DEXPREOPT_IMAGE_DEPS_"+sfx, strings.Join(variant.imagesDeps.Strings(), " "))
 				ctx.Strict("DEXPREOPT_IMAGE_BUILT_INSTALLED_"+sfx, variant.installs.String())
 				ctx.Strict("DEXPREOPT_IMAGE_UNSTRIPPED_BUILT_INSTALLED_"+sfx, variant.unstrippedInstalls.String())
+				if variant.licenseMetadataFile.Valid() {
+					ctx.Strict("DEXPREOPT_IMAGE_LICENSE_METADATA_"+sfx, variant.licenseMetadataFile.String())
+				}
 			}
 			imageLocationsOnHost, imageLocationsOnDevice := current.getAnyAndroidVariant().imageLocations()
 			ctx.Strict("DEXPREOPT_IMAGE_LOCATIONS_ON_HOST"+current.name, strings.Join(imageLocationsOnHost, ":"))
diff --git a/java/dexpreopt_config.go b/java/dexpreopt_config.go
index 21e1d12..4d0bd09 100644
--- a/java/dexpreopt_config.go
+++ b/java/dexpreopt_config.go
@@ -62,18 +62,20 @@
 			installDirOnDevice:       "system/framework",
 			profileInstallPathInApex: "etc/boot-image.prof",
 			modules:                  artModules,
+			preloadedClassesFile:     "art/build/boot/preloaded-classes",
 		}
 
 		// Framework config for the boot image extension.
 		// It includes framework libraries and depends on the ART config.
 		frameworkSubdir := "system/framework"
 		frameworkCfg := bootImageConfig{
-			extends:            &artCfg,
-			name:               frameworkBootImageName,
-			stem:               "boot",
-			installDirOnHost:   frameworkSubdir,
-			installDirOnDevice: frameworkSubdir,
-			modules:            frameworkModules,
+			extends:              &artCfg,
+			name:                 frameworkBootImageName,
+			stem:                 "boot",
+			installDirOnHost:     frameworkSubdir,
+			installDirOnDevice:   frameworkSubdir,
+			modules:              frameworkModules,
+			preloadedClassesFile: "frameworks/base/config/preloaded-classes",
 		}
 
 		return map[string]*bootImageConfig{
diff --git a/java/droidstubs.go b/java/droidstubs.go
index 5dc7bc9..2921c3e 100644
--- a/java/droidstubs.go
+++ b/java/droidstubs.go
@@ -334,7 +334,11 @@
 		// TODO(tnorbye): find owners to fix these warnings when annotation was enabled.
 		cmd.FlagWithArg("--hide ", "HiddenTypedefConstant").
 			FlagWithArg("--hide ", "SuperfluousPrefix").
-			FlagWithArg("--hide ", "AnnotationExtraction")
+			FlagWithArg("--hide ", "AnnotationExtraction").
+			// b/222738070
+			FlagWithArg("--hide ", "BannedThrow").
+			// b/223382732
+			FlagWithArg("--hide ", "ChangedDefault")
 	}
 }
 
@@ -473,7 +477,9 @@
 		Flag("--format=v2").
 		FlagWithArg("--repeat-errors-max ", "10").
 		FlagWithArg("--hide ", "UnresolvedImport").
-		FlagWithArg("--hide ", "InvalidNullability")
+		FlagWithArg("--hide ", "InvalidNullability").
+		// b/223382732
+		FlagWithArg("--hide ", "ChangedDefault")
 
 	return cmd
 }
diff --git a/java/hiddenapi_modular.go b/java/hiddenapi_modular.go
index 0cc960d..95ded34 100644
--- a/java/hiddenapi_modular.go
+++ b/java/hiddenapi_modular.go
@@ -943,7 +943,9 @@
 
 // buildRuleSignaturePatternsFile creates a rule to generate a file containing the set of signature
 // patterns that will select a subset of the monolithic flags.
-func buildRuleSignaturePatternsFile(ctx android.ModuleContext, flagsPath android.Path, splitPackages []string, packagePrefixes []string) android.Path {
+func buildRuleSignaturePatternsFile(
+	ctx android.ModuleContext, flagsPath android.Path,
+	splitPackages []string, packagePrefixes []string, singlePackages []string) android.Path {
 	patternsFile := android.PathForModuleOut(ctx, "modular-hiddenapi", "signature-patterns.csv")
 	// Create a rule to validate the output from the following rule.
 	rule := android.NewRuleBuilder(pctx, ctx)
@@ -959,6 +961,7 @@
 		FlagWithInput("--flags ", flagsPath).
 		FlagForEachArg("--split-package ", quotedSplitPackages).
 		FlagForEachArg("--package-prefix ", packagePrefixes).
+		FlagForEachArg("--single-package ", singlePackages).
 		FlagWithOutput("--output ", patternsFile)
 	rule.Build("hiddenAPISignaturePatterns", "hidden API signature patterns")
 
diff --git a/java/java.go b/java/java.go
index d0f0abc..895ce7a 100644
--- a/java/java.go
+++ b/java/java.go
@@ -2011,8 +2011,16 @@
 }
 
 func (m *Library) convertLibraryAttrsBp2Build(ctx android.TopDownMutatorContext) *javaLibraryAttributes {
-	//TODO(b/209577426): Support multiple arch variants
-	srcs := bazel.MakeLabelListAttribute(android.BazelLabelForModuleSrcExcludes(ctx, m.properties.Srcs, m.properties.Exclude_srcs))
+	var srcs bazel.LabelListAttribute
+	archVariantProps := m.GetArchVariantProperties(ctx, &CommonProperties{})
+	for axis, configToProps := range archVariantProps {
+		for config, _props := range configToProps {
+			if archProps, ok := _props.(*CommonProperties); ok {
+				archSrcs := android.BazelLabelForModuleSrcExcludes(ctx, archProps.Srcs, archProps.Exclude_srcs)
+				srcs.SetSelectValue(axis, config, archSrcs)
+			}
+		}
+	}
 
 	javaSrcPartition := "java"
 	protoSrcPartition := "proto"
@@ -2030,6 +2038,11 @@
 	}
 
 	var deps bazel.LabelList
+	sdkVersion := m.SdkVersion(ctx)
+	if sdkVersion.Kind == android.SdkPublic && sdkVersion.ApiLevel == android.FutureApiLevel {
+		// TODO(b/220869005) remove forced dependency on current public android.jar
+		deps.Add(&bazel.Label{Label: "//prebuilts/sdk:public_current_android_sdk_java_import"})
+	}
 	if m.properties.Libs != nil {
 		deps.Append(android.BazelLabelForModuleDeps(ctx, m.properties.Libs))
 	}
diff --git a/java/legacy_core_platform_api_usage.go b/java/legacy_core_platform_api_usage.go
index e3396c1..8e22491 100644
--- a/java/legacy_core_platform_api_usage.go
+++ b/java/legacy_core_platform_api_usage.go
@@ -81,7 +81,6 @@
 	"ds-car-docs", // for AAOS API documentation only
 	"DynamicSystemInstallationService",
 	"EmergencyInfo-lib",
-	"ethernet-service",
 	"EthernetServiceTests",
 	"ExternalStorageProvider",
 	"face-V1-0-javalib",
diff --git a/linkerconfig/linkerconfig.go b/linkerconfig/linkerconfig.go
index dbc112e..003b275 100644
--- a/linkerconfig/linkerconfig.go
+++ b/linkerconfig/linkerconfig.go
@@ -158,7 +158,6 @@
 				entries.SetString("LOCAL_MODULE_PATH", l.installDirPath.String())
 				entries.SetString("LOCAL_INSTALLED_MODULE_STEM", l.outputFilePath.Base())
 				entries.SetBoolIfTrue("LOCAL_UNINSTALLABLE_MODULE", !installable)
-				entries.SetString("LINKER_CONFIG_PATH_"+l.Name(), l.OutputFile().String())
 			},
 		},
 	}}
diff --git a/mk2rbc/mk2rbc.go b/mk2rbc/mk2rbc.go
index 74053fe..212b7f6 100644
--- a/mk2rbc/mk2rbc.go
+++ b/mk2rbc/mk2rbc.go
@@ -50,15 +50,12 @@
 	soongNsPrefix = "SOONG_CONFIG_"
 
 	// And here are the functions and variables:
-	cfnGetCfg          = baseName + ".cfg"
-	cfnMain            = baseName + ".product_configuration"
-	cfnBoardMain       = baseName + ".board_configuration"
-	cfnPrintVars       = baseName + ".printvars"
-	cfnWarning         = baseName + ".warning"
-	cfnLocalAppend     = baseName + ".local_append"
-	cfnLocalSetDefault = baseName + ".local_set_default"
-	cfnInherit         = baseName + ".inherit"
-	cfnSetListDefault  = baseName + ".setdefault"
+	cfnGetCfg         = baseName + ".cfg"
+	cfnMain           = baseName + ".product_configuration"
+	cfnBoardMain      = baseName + ".board_configuration"
+	cfnPrintVars      = baseName + ".printvars"
+	cfnInherit        = baseName + ".inherit"
+	cfnSetListDefault = baseName + ".setdefault"
 )
 
 const (
@@ -410,6 +407,8 @@
 	dependentModules map[string]*moduleInfo
 	soongNamespaces  map[string]map[string]bool
 	includeTops      []string
+	typeHints        map[string]starlarkType
+	atTopOfMakefile  bool
 }
 
 func newParseContext(ss *StarlarkScript, nodes []mkparser.Node) *parseContext {
@@ -453,6 +452,8 @@
 		dependentModules: make(map[string]*moduleInfo),
 		soongNamespaces:  make(map[string]map[string]bool),
 		includeTops:      []string{},
+		typeHints:        make(map[string]starlarkType),
+		atTopOfMakefile:  true,
 	}
 	ctx.pushVarAssignments()
 	for _, item := range predefined {
@@ -465,17 +466,17 @@
 	return ctx
 }
 
-func (ctx *parseContext) lastAssignment(name string) *assignmentNode {
+func (ctx *parseContext) lastAssignment(v variable) *assignmentNode {
 	for va := ctx.varAssignments; va != nil; va = va.outer {
-		if v, ok := va.vars[name]; ok {
+		if v, ok := va.vars[v.name()]; ok {
 			return v
 		}
 	}
 	return nil
 }
 
-func (ctx *parseContext) setLastAssignment(name string, asgn *assignmentNode) {
-	ctx.varAssignments.vars[name] = asgn
+func (ctx *parseContext) setLastAssignment(v variable, asgn *assignmentNode) {
+	ctx.varAssignments.vars[v.name()] = asgn
 }
 
 func (ctx *parseContext) pushVarAssignments() {
@@ -532,7 +533,7 @@
 	if lhs == nil {
 		return []starlarkNode{ctx.newBadNode(a, "unknown variable %s", name)}
 	}
-	_, isTraced := ctx.tracedVariables[name]
+	_, isTraced := ctx.tracedVariables[lhs.name()]
 	asgn := &assignmentNode{lhs: lhs, mkValue: a.Value, isTraced: isTraced, location: ctx.errorLocation(a)}
 	if lhs.valueType() == starlarkTypeUnknown {
 		// Try to divine variable type from the RHS
@@ -565,17 +566,19 @@
 		}
 	}
 
-	asgn.previous = ctx.lastAssignment(name)
-	ctx.setLastAssignment(name, asgn)
+	if asgn.lhs.valueType() == starlarkTypeString &&
+		asgn.value.typ() != starlarkTypeUnknown &&
+		asgn.value.typ() != starlarkTypeString {
+		asgn.value = &toStringExpr{expr: asgn.value}
+	}
+
+	asgn.previous = ctx.lastAssignment(lhs)
+	ctx.setLastAssignment(lhs, asgn)
 	switch a.Type {
 	case "=", ":=":
 		asgn.flavor = asgnSet
 	case "+=":
-		if asgn.previous == nil && !asgn.lhs.isPreset() {
-			asgn.flavor = asgnMaybeAppend
-		} else {
-			asgn.flavor = asgnAppend
-		}
+		asgn.flavor = asgnAppend
 	case "?=":
 		asgn.flavor = asgnMaybeSet
 	default:
@@ -1268,12 +1271,12 @@
 				args: []starlarkExpr{
 					&stringLiteralExpr{literal: substParts[0]},
 					&stringLiteralExpr{literal: substParts[1]},
-					NewVariableRefExpr(v, ctx.lastAssignment(v.name()) != nil),
+					NewVariableRefExpr(v, ctx.lastAssignment(v) != nil),
 				},
 			}
 		}
 		if v := ctx.addVariable(refDump); v != nil {
-			return NewVariableRefExpr(v, ctx.lastAssignment(v.name()) != nil)
+			return NewVariableRefExpr(v, ctx.lastAssignment(v) != nil)
 		}
 		return ctx.newBadExpr(node, "unknown variable %s", refDump)
 	}
@@ -1687,7 +1690,8 @@
 	// Clear the includeTops after each non-comment statement
 	// so that include annotations placed on certain statements don't apply
 	// globally for the rest of the makefile was well.
-	if _, wasComment := node.(*mkparser.Comment); !wasComment && len(ctx.includeTops) > 0 {
+	if _, wasComment := node.(*mkparser.Comment); !wasComment {
+		ctx.atTopOfMakefile = false
 		ctx.includeTops = []string{}
 	}
 
@@ -1697,6 +1701,12 @@
 	return result
 }
 
+// The types allowed in a type_hint
+var typeHintMap = map[string]starlarkType{
+	"string": starlarkTypeString,
+	"list":   starlarkTypeList,
+}
+
 // Processes annotation. An annotation is a comment that starts with #RBC# and provides
 // a conversion hint -- say, where to look for the dynamically calculated inherit/include
 // paths. Returns true if the comment was a successfully-handled annotation.
@@ -1721,6 +1731,35 @@
 		}
 		ctx.includeTops = append(ctx.includeTops, p)
 		return nil, true
+	} else if p, ok := maybeTrim(annotation, "type_hint"); ok {
+		// Type hints must come at the beginning the file, to avoid confusion
+		// if a type hint was specified later and thus only takes effect for half
+		// of the file.
+		if !ctx.atTopOfMakefile {
+			return ctx.newBadNode(cnode, "type_hint annotations must come before the first Makefile statement"), true
+		}
+
+		parts := strings.Fields(p)
+		if len(parts) <= 1 {
+			return ctx.newBadNode(cnode, "Invalid type_hint annotation: %s. Must be a variable type followed by a list of variables of that type", p), true
+		}
+
+		var varType starlarkType
+		if varType, ok = typeHintMap[parts[0]]; !ok {
+			varType = starlarkTypeUnknown
+		}
+		if varType == starlarkTypeUnknown {
+			return ctx.newBadNode(cnode, "Invalid type_hint annotation. Only list/string types are accepted, found %s", parts[0]), true
+		}
+
+		for _, name := range parts[1:] {
+			// Don't allow duplicate type hints
+			if _, ok := ctx.typeHints[name]; ok {
+				return ctx.newBadNode(cnode, "Duplicate type hint for variable %s", name), true
+			}
+			ctx.typeHints[name] = varType
+		}
+		return nil, true
 	}
 	return ctx.newBadNode(cnode, "unsupported annotation %s", cnode.Comment), true
 }
diff --git a/mk2rbc/mk2rbc_test.go b/mk2rbc/mk2rbc_test.go
index 55d48ff..08926e5 100644
--- a/mk2rbc/mk2rbc_test.go
+++ b/mk2rbc/mk2rbc_test.go
@@ -65,6 +65,10 @@
 PRODUCT_NAME := Pixel 3
 PRODUCT_MODEL :=
 local_var = foo
+local-var-with-dashes := bar
+$(warning local-var-with-dashes: $(local-var-with-dashes))
+GLOBAL-VAR-WITH-DASHES := baz
+$(warning GLOBAL-VAR-WITH-DASHES: $(GLOBAL-VAR-WITH-DASHES))
 `,
 		expected: `load("//build/make/core:product_config.rbc", "rblf")
 
@@ -73,6 +77,10 @@
   cfg["PRODUCT_NAME"] = "Pixel 3"
   cfg["PRODUCT_MODEL"] = ""
   _local_var = "foo"
+  _local_var_with_dashes = "bar"
+  rblf.mkwarning("pixel3.mk", "local-var-with-dashes: %s" % _local_var_with_dashes)
+  g["GLOBAL-VAR-WITH-DASHES"] = "baz"
+  rblf.mkwarning("pixel3.mk", "GLOBAL-VAR-WITH-DASHES: %s" % g["GLOBAL-VAR-WITH-DASHES"])
 `,
 	},
 	{
@@ -893,6 +901,43 @@
 `,
 	},
 	{
+		desc:   "assigment setdefaults",
+		mkname: "product.mk",
+		in: `
+# All of these should have a setdefault because they're self-referential and not defined before
+PRODUCT_LIST1 = a $(PRODUCT_LIST1)
+PRODUCT_LIST2 ?= a $(PRODUCT_LIST2)
+PRODUCT_LIST3 += a
+
+# Now doing them again should not have a setdefault because they've already been set
+PRODUCT_LIST1 = a $(PRODUCT_LIST1)
+PRODUCT_LIST2 ?= a $(PRODUCT_LIST2)
+PRODUCT_LIST3 += a
+`,
+		expected: `# All of these should have a setdefault because they're self-referential and not defined before
+load("//build/make/core:product_config.rbc", "rblf")
+
+def init(g, handle):
+  cfg = rblf.cfg(handle)
+  rblf.setdefault(handle, "PRODUCT_LIST1")
+  cfg["PRODUCT_LIST1"] = (["a"] +
+      cfg.get("PRODUCT_LIST1", []))
+  if cfg.get("PRODUCT_LIST2") == None:
+    rblf.setdefault(handle, "PRODUCT_LIST2")
+    cfg["PRODUCT_LIST2"] = (["a"] +
+        cfg.get("PRODUCT_LIST2", []))
+  rblf.setdefault(handle, "PRODUCT_LIST3")
+  cfg["PRODUCT_LIST3"] += ["a"]
+  # Now doing them again should not have a setdefault because they've already been set
+  cfg["PRODUCT_LIST1"] = (["a"] +
+      cfg["PRODUCT_LIST1"])
+  if cfg.get("PRODUCT_LIST2") == None:
+    cfg["PRODUCT_LIST2"] = (["a"] +
+        cfg["PRODUCT_LIST2"])
+  cfg["PRODUCT_LIST3"] += ["a"]
+`,
+	},
+	{
 		desc:   "soong namespace assignments",
 		mkname: "product.mk",
 		in: `
@@ -985,6 +1030,7 @@
 def init(g, handle):
   cfg = rblf.cfg(handle)
   if "hwaddress" not in cfg.get("PRODUCT_PACKAGES", []):
+    rblf.setdefault(handle, "PRODUCT_PACKAGES")
     cfg["PRODUCT_PACKAGES"] = (rblf.mkstrip("%s hwaddress" % " ".join(cfg.get("PRODUCT_PACKAGES", [])))).split()
 `,
 	},
@@ -1219,7 +1265,7 @@
 TEST_VAR_LIST += bar
 TEST_VAR_2 := $(if $(TEST_VAR),bar)
 TEST_VAR_3 := $(if $(TEST_VAR),bar,baz)
-TEST_VAR_3 := $(if $(TEST_VAR),$(TEST_VAR_LIST))
+TEST_VAR_4 := $(if $(TEST_VAR),$(TEST_VAR_LIST))
 `,
 		expected: `load("//build/make/core:product_config.rbc", "rblf")
 
@@ -1230,7 +1276,7 @@
   g["TEST_VAR_LIST"] += ["bar"]
   g["TEST_VAR_2"] = ("bar" if g["TEST_VAR"] else "")
   g["TEST_VAR_3"] = ("bar" if g["TEST_VAR"] else "baz")
-  g["TEST_VAR_3"] = (g["TEST_VAR_LIST"] if g["TEST_VAR"] else [])
+  g["TEST_VAR_4"] = (g["TEST_VAR_LIST"] if g["TEST_VAR"] else [])
 `,
 	},
 	{
@@ -1360,6 +1406,57 @@
     pass
 `,
 	},
+	{
+		desc:   "Type hints",
+		mkname: "product.mk",
+		in: `
+# Test type hints
+#RBC# type_hint list MY_VAR MY_VAR_2
+# Unsupported type
+#RBC# type_hint bool MY_VAR_3
+# Invalid syntax
+#RBC# type_hint list
+# Duplicated variable
+#RBC# type_hint list MY_VAR_2
+#RBC# type_hint list my-local-var-with-dashes
+#RBC# type_hint string MY_STRING_VAR
+
+MY_VAR := foo
+MY_VAR_UNHINTED := foo
+
+# Vars set after other statements still get the hint
+MY_VAR_2 := foo
+
+# You can't specify a type hint after the first statement
+#RBC# type_hint list MY_VAR_4
+MY_VAR_4 := foo
+
+my-local-var-with-dashes := foo
+
+MY_STRING_VAR := $(wildcard foo/bar.mk)
+`,
+		expected: `# Test type hints
+# Unsupported type
+load("//build/make/core:product_config.rbc", "rblf")
+
+def init(g, handle):
+  cfg = rblf.cfg(handle)
+  rblf.mk2rbc_error("product.mk:5", "Invalid type_hint annotation. Only list/string types are accepted, found bool")
+  # Invalid syntax
+  rblf.mk2rbc_error("product.mk:7", "Invalid type_hint annotation: list. Must be a variable type followed by a list of variables of that type")
+  # Duplicated variable
+  rblf.mk2rbc_error("product.mk:9", "Duplicate type hint for variable MY_VAR_2")
+  g["MY_VAR"] = ["foo"]
+  g["MY_VAR_UNHINTED"] = "foo"
+  # Vars set after other statements still get the hint
+  g["MY_VAR_2"] = ["foo"]
+  # You can't specify a type hint after the first statement
+  rblf.mk2rbc_error("product.mk:20", "type_hint annotations must come before the first Makefile statement")
+  g["MY_VAR_4"] = "foo"
+  _my_local_var_with_dashes = ["foo"]
+  g["MY_STRING_VAR"] = " ".join(rblf.expand_wildcard("foo/bar.mk"))
+`,
+	},
 }
 
 var known_variables = []struct {
diff --git a/mk2rbc/node.go b/mk2rbc/node.go
index 5d98d7b..9d5af91 100644
--- a/mk2rbc/node.go
+++ b/mk2rbc/node.go
@@ -184,10 +184,9 @@
 
 const (
 	// Assignment flavors
-	asgnSet         assignmentFlavor = iota // := or =
-	asgnMaybeSet    assignmentFlavor = iota // ?= and variable may be unset
-	asgnAppend      assignmentFlavor = iota // += and variable has been set before
-	asgnMaybeAppend assignmentFlavor = iota // += and variable may be unset
+	asgnSet      assignmentFlavor = iota // := or =
+	asgnMaybeSet assignmentFlavor = iota // ?=
+	asgnAppend   assignmentFlavor = iota // +=
 )
 
 type assignmentNode struct {
@@ -215,6 +214,20 @@
 	}
 }
 
+func (asgn *assignmentNode) isSelfReferential() bool {
+	if asgn.flavor == asgnAppend {
+		return true
+	}
+	isSelfReferential := false
+	asgn.value.transform(func(expr starlarkExpr) starlarkExpr {
+		if ref, ok := expr.(*variableRefExpr); ok && ref.ref.name() == asgn.lhs.name() {
+			isSelfReferential = true
+		}
+		return nil
+	})
+	return isSelfReferential
+}
+
 type exprNode struct {
 	expr starlarkExpr
 }
diff --git a/mk2rbc/variable.go b/mk2rbc/variable.go
index f7adca5..506266a 100644
--- a/mk2rbc/variable.go
+++ b/mk2rbc/variable.go
@@ -88,25 +88,36 @@
 		}
 		value.emit(gctx)
 	}
-
-	switch asgn.flavor {
-	case asgnSet:
-		emitAssignment()
-	case asgnAppend:
-		emitAppend()
-	case asgnMaybeAppend:
-		// If we are not sure variable has been assigned before, emit setdefault
+	emitSetDefault := func() {
 		if pcv.typ == starlarkTypeList {
 			gctx.writef("%s(handle, %q)", cfnSetListDefault, pcv.name())
 		} else {
 			gctx.writef("cfg.setdefault(%q, %s)", pcv.name(), pcv.defaultValueString())
 		}
 		gctx.newLine()
+	}
+
+	// If we are not sure variable has been assigned before, emit setdefault
+	needsSetDefault := asgn.previous == nil && !pcv.isPreset() && asgn.isSelfReferential()
+
+	switch asgn.flavor {
+	case asgnSet:
+		if needsSetDefault {
+			emitSetDefault()
+		}
+		emitAssignment()
+	case asgnAppend:
+		if needsSetDefault {
+			emitSetDefault()
+		}
 		emitAppend()
 	case asgnMaybeSet:
 		gctx.writef("if cfg.get(%q) == None:", pcv.nam)
 		gctx.indentLevel++
 		gctx.newLine()
+		if needsSetDefault {
+			emitSetDefault()
+		}
 		emitAssignment()
 		gctx.indentLevel--
 	}
@@ -121,7 +132,7 @@
 }
 
 func (pcv productConfigVariable) emitDefined(gctx *generationContext) {
-	gctx.writef("g.get(%q) != None", pcv.name())
+	gctx.writef("cfg.get(%q) != None", pcv.name())
 }
 
 type otherGlobalVariable struct {
@@ -146,20 +157,30 @@
 		value.emit(gctx)
 	}
 
+	// If we are not sure variable has been assigned before, emit setdefault
+	needsSetDefault := asgn.previous == nil && !scv.isPreset() && asgn.isSelfReferential()
+
 	switch asgn.flavor {
 	case asgnSet:
+		if needsSetDefault {
+			gctx.writef("g.setdefault(%q, %s)", scv.name(), scv.defaultValueString())
+			gctx.newLine()
+		}
 		emitAssignment()
 	case asgnAppend:
-		emitAppend()
-	case asgnMaybeAppend:
-		// If we are not sure variable has been assigned before, emit setdefault
-		gctx.writef("g.setdefault(%q, %s)", scv.name(), scv.defaultValueString())
-		gctx.newLine()
+		if needsSetDefault {
+			gctx.writef("g.setdefault(%q, %s)", scv.name(), scv.defaultValueString())
+			gctx.newLine()
+		}
 		emitAppend()
 	case asgnMaybeSet:
 		gctx.writef("if g.get(%q) == None:", scv.nam)
 		gctx.indentLevel++
 		gctx.newLine()
+		if needsSetDefault {
+			gctx.writef("g.setdefault(%q, %s)", scv.name(), scv.defaultValueString())
+			gctx.newLine()
+		}
 		emitAssignment()
 		gctx.indentLevel--
 	}
@@ -191,7 +212,7 @@
 
 func (lv localVariable) emitSet(gctx *generationContext, asgn *assignmentNode) {
 	switch asgn.flavor {
-	case asgnSet:
+	case asgnSet, asgnMaybeSet:
 		gctx.writef("%s = ", lv)
 		asgn.value.emitListVarCopy(gctx)
 	case asgnAppend:
@@ -203,14 +224,6 @@
 			value = &toStringExpr{expr: value}
 		}
 		value.emit(gctx)
-	case asgnMaybeAppend:
-		gctx.writef("%s(%q, ", cfnLocalAppend, lv)
-		asgn.value.emit(gctx)
-		gctx.write(")")
-	case asgnMaybeSet:
-		gctx.writef("%s(%q, ", cfnLocalSetDefault, lv)
-		asgn.value.emit(gctx)
-		gctx.write(")")
 	}
 }
 
@@ -278,23 +291,35 @@
 // addVariable returns a variable with a given name. A variable is
 // added if it does not exist yet.
 func (ctx *parseContext) addVariable(name string) variable {
+	// Get the hintType before potentially changing the variable name
+	var hintType starlarkType
+	var ok bool
+	if hintType, ok = ctx.typeHints[name]; !ok {
+		hintType = starlarkTypeUnknown
+	}
+	// Heuristics: if variable's name is all lowercase, consider it local
+	// string variable.
+	isLocalVariable := name == strings.ToLower(name)
+	// Local variables can't have special characters in them, because they
+	// will be used as starlark identifiers
+	if isLocalVariable {
+		name = strings.ReplaceAll(strings.TrimSpace(name), "-", "_")
+	}
 	v, found := ctx.variables[name]
 	if !found {
-		_, preset := presetVariables[name]
 		if vi, found := KnownVariables[name]; found {
+			_, preset := presetVariables[name]
 			switch vi.class {
 			case VarClassConfig:
 				v = &productConfigVariable{baseVariable{nam: name, typ: vi.valueType, preset: preset}}
 			case VarClassSoong:
 				v = &otherGlobalVariable{baseVariable{nam: name, typ: vi.valueType, preset: preset}}
 			}
-		} else if name == strings.ToLower(name) {
-			// Heuristics: if variable's name is all lowercase, consider it local
-			// string variable.
-			v = &localVariable{baseVariable{nam: name, typ: starlarkTypeUnknown}}
+		} else if isLocalVariable {
+			v = &localVariable{baseVariable{nam: name, typ: hintType}}
 		} else {
-			vt := starlarkTypeUnknown
-			if strings.HasPrefix(name, "LOCAL_") {
+			vt := hintType
+			if strings.HasPrefix(name, "LOCAL_") && vt == starlarkTypeUnknown {
 				// Heuristics: local variables that contribute to corresponding config variables
 				if cfgVarName, found := localProductConfigVariables[name]; found {
 					vi, found2 := KnownVariables[cfgVarName]
diff --git a/python/python.go b/python/python.go
index 734ac57..b100cc3 100644
--- a/python/python.go
+++ b/python/python.go
@@ -423,6 +423,9 @@
 		if ctx.Target().Os.Bionic() {
 			launcherSharedLibDeps = append(launcherSharedLibDeps, "libc", "libdl", "libm")
 		}
+		if ctx.Target().Os == android.LinuxMusl && !ctx.Config().HostStaticBinaries() {
+			launcherSharedLibDeps = append(launcherSharedLibDeps, "libc_musl")
+		}
 
 		switch p.properties.Actual_version {
 		case pyVersion2:
@@ -432,6 +435,7 @@
 			if p.bootstrapper.autorun() {
 				launcherModule = "py2-launcher-autorun"
 			}
+
 			launcherSharedLibDeps = append(launcherSharedLibDeps, "libc++")
 
 		case pyVersion3:
@@ -441,6 +445,9 @@
 			if p.bootstrapper.autorun() {
 				launcherModule = "py3-launcher-autorun"
 			}
+			if ctx.Config().HostStaticBinaries() && ctx.Target().Os == android.LinuxMusl {
+				launcherModule += "-static"
+			}
 
 			if ctx.Device() {
 				launcherSharedLibDeps = append(launcherSharedLibDeps, "liblog")
diff --git a/rust/compiler.go b/rust/compiler.go
index c5d40f4..19499fa 100644
--- a/rust/compiler.go
+++ b/rust/compiler.go
@@ -121,6 +121,12 @@
 	// include all of the static libraries symbols in any dylibs or binaries which use this rlib as well.
 	Whole_static_libs []string `android:"arch_variant"`
 
+	// list of Rust system library dependencies.
+	//
+	// This is usually only needed when `no_stdlibs` is true, in which case it can be used to depend on system crates
+	// like `core` and `alloc`.
+	Stdlibs []string `android:"arch_variant"`
+
 	// crate name, required for modules which produce Rust libraries: rust_library, rust_ffi and SourceProvider
 	// modules which create library variants (rust_bindgen). This must be the expected extern crate name used in
 	// source, and is required to conform to an enforced format matching library output files (if the output file is
@@ -360,6 +366,7 @@
 	deps.StaticLibs = append(deps.StaticLibs, compiler.Properties.Static_libs...)
 	deps.WholeStaticLibs = append(deps.WholeStaticLibs, compiler.Properties.Whole_static_libs...)
 	deps.SharedLibs = append(deps.SharedLibs, compiler.Properties.Shared_libs...)
+	deps.Stdlibs = append(deps.Stdlibs, compiler.Properties.Stdlibs...)
 
 	if !Bool(compiler.Properties.No_stdlibs) {
 		for _, stdlib := range config.Stdlibs {
diff --git a/rust/config/allowed_list.go b/rust/config/allowed_list.go
index 14fcb02..bc36b20 100644
--- a/rust/config/allowed_list.go
+++ b/rust/config/allowed_list.go
@@ -24,6 +24,7 @@
 		"packages/modules/DnsResolver",
 		"packages/modules/Uwb",
 		"packages/modules/Virtualization",
+		"platform_testing/tests/codecoverage/native/rust",
 		"prebuilts/rust",
 		"system/core/libstats/pull_rust",
 		"system/extras/profcollectd",
diff --git a/rust/config/toolchain.go b/rust/config/toolchain.go
index a769f12..9c9d572 100644
--- a/rust/config/toolchain.go
+++ b/rust/config/toolchain.go
@@ -121,14 +121,7 @@
 }
 
 func LibclangRuntimeLibrary(t Toolchain, library string) string {
-	arch := t.LibclangRuntimeLibraryArch()
-	if arch == "" {
-		return ""
-	}
-	if !t.Bionic() {
-		return "libclang_rt." + library + "-" + arch
-	}
-	return "libclang_rt." + library + "-" + arch + "-android"
+	return "libclang_rt." + library
 }
 
 func LibRustRuntimeLibrary(t Toolchain, library string) string {
diff --git a/rust/coverage.go b/rust/coverage.go
index 050b811..651ce6e 100644
--- a/rust/coverage.go
+++ b/rust/coverage.go
@@ -22,6 +22,7 @@
 
 var CovLibraryName = "libprofile-clang-extras"
 
+// Add '%c' to default specifier after we resolve http://b/210012154
 const profileInstrFlag = "-fprofile-instr-generate=/data/misc/trace/clang-%p-%m.profraw"
 
 type coverage struct {
@@ -59,6 +60,10 @@
 		flags.LinkFlags = append(flags.LinkFlags,
 			profileInstrFlag, "-g", coverage.OutputFile().Path().String(), "-Wl,--wrap,open")
 		deps.StaticLibs = append(deps.StaticLibs, coverage.OutputFile().Path())
+		if cc.EnableContinuousCoverage(ctx) {
+			flags.RustFlags = append(flags.RustFlags, "-C llvm-args=--runtime-counter-relocation")
+			flags.LinkFlags = append(flags.LinkFlags, "-Wl,-mllvm,-runtime-counter-relocation")
+		}
 	}
 
 	return flags, deps
diff --git a/rust/image.go b/rust/image.go
index 5d57f15..dfc7f74 100644
--- a/rust/image.go
+++ b/rust/image.go
@@ -149,6 +149,10 @@
 	return mod.ModuleBase.InRecovery() || mod.ModuleBase.InstallInRecovery()
 }
 
+func (mod *Module) InRamdisk() bool {
+	return mod.ModuleBase.InRamdisk() || mod.ModuleBase.InstallInRamdisk()
+}
+
 func (mod *Module) InVendorRamdisk() bool {
 	return mod.ModuleBase.InVendorRamdisk() || mod.ModuleBase.InstallInVendorRamdisk()
 }
diff --git a/rust/rust.go b/rust/rust.go
index f40f1a8..1c718a4 100644
--- a/rust/rust.go
+++ b/rust/rust.go
@@ -968,6 +968,7 @@
 	deps.ProcMacros = android.LastUniqueStrings(deps.ProcMacros)
 	deps.SharedLibs = android.LastUniqueStrings(deps.SharedLibs)
 	deps.StaticLibs = android.LastUniqueStrings(deps.StaticLibs)
+	deps.Stdlibs = android.LastUniqueStrings(deps.Stdlibs)
 	deps.WholeStaticLibs = android.LastUniqueStrings(deps.WholeStaticLibs)
 	return deps
 
diff --git a/rust/testing.go b/rust/testing.go
index 1b34dfe..cb98bed 100644
--- a/rust/testing.go
+++ b/rust/testing.go
@@ -88,13 +88,13 @@
 			export_include_dirs: ["libprotobuf-cpp-full-includes"],
 		}
 		cc_library {
-			name: "libclang_rt.asan-aarch64-android",
+			name: "libclang_rt.asan",
 			no_libcrt: true,
 			nocrt: true,
 			system_shared_libs: [],
 		}
 		cc_library {
-			name: "libclang_rt.hwasan_static-aarch64-android",
+			name: "libclang_rt.hwasan_static",
 			no_libcrt: true,
 			nocrt: true,
 			system_shared_libs: [],
diff --git a/rust/vendor_snapshot_test.go b/rust/vendor_snapshot_test.go
index 03bd867..7be0042 100644
--- a/rust/vendor_snapshot_test.go
+++ b/rust/vendor_snapshot_test.go
@@ -561,7 +561,7 @@
 				static_libs: [
 					"libvendor",
 					"libvndk",
-					"libclang_rt.builtins-aarch64-android",
+					"libclang_rt.builtins",
 					"note_memtag_heap_sync",
 				],
 				shared_libs: [
@@ -589,7 +589,7 @@
 				static_libs: [
 					"libvendor",
 					"libvndk",
-					"libclang_rt.builtins-arm-android",
+					"libclang_rt.builtins",
 				],
 				shared_libs: [
 					"libvendor_available",
@@ -731,19 +731,7 @@
 	}
 
 	vendor_snapshot_static {
-		name: "libclang_rt.builtins-aarch64-android",
-		version: "30",
-		target_arch: "arm64",
-		vendor: true,
-		arch: {
-			arm64: {
-				src: "libclang_rt.builtins-aarch64-android.a",
-			},
-		},
-    }
-
-    vendor_snapshot_static {
-		name: "libclang_rt.builtins-arm-android",
+		name: "libclang_rt.builtins",
 		version: "30",
 		target_arch: "arm64",
 		vendor: true,
@@ -751,6 +739,9 @@
 			arm: {
 				src: "libclang_rt.builtins-arm-android.a",
 			},
+			arm64: {
+				src: "libclang_rt.builtins-aarch64-android.a",
+			},
 		},
     }
 
@@ -967,7 +958,7 @@
 	}
 
 	libclientAndroidMkStaticLibs := ctx.ModuleForTests("libclient", sharedVariant).Module().(*Module).Properties.AndroidMkStaticLibs
-	if g, w := libclientAndroidMkStaticLibs, []string{"libvendor", "libvendor_without_snapshot", "libclang_rt.builtins-aarch64-android.vendor"}; !reflect.DeepEqual(g, w) {
+	if g, w := libclientAndroidMkStaticLibs, []string{"libvendor", "libvendor_without_snapshot", "libclang_rt.builtins.vendor"}; !reflect.DeepEqual(g, w) {
 		t.Errorf("wanted libclient AndroidMkStaticLibs %q, got %q", w, g)
 	}
 
@@ -1024,7 +1015,7 @@
 	}
 
 	memtagStaticLibs := ctx.ModuleForTests("memtag_binary", "android_vendor.30_arm64_armv8-a").Module().(*Module).Properties.AndroidMkStaticLibs
-	if g, w := memtagStaticLibs, []string{"libclang_rt.builtins-aarch64-android.vendor", "note_memtag_heap_sync.vendor"}; !reflect.DeepEqual(g, w) {
+	if g, w := memtagStaticLibs, []string{"libclang_rt.builtins.vendor", "note_memtag_heap_sync.vendor"}; !reflect.DeepEqual(g, w) {
 		t.Errorf("wanted memtag_binary AndroidMkStaticLibs %q, got %q", w, g)
 	}
 }
diff --git a/scripts/hiddenapi/Android.bp b/scripts/hiddenapi/Android.bp
index 7ffda62..8a47c5d 100644
--- a/scripts/hiddenapi/Android.bp
+++ b/scripts/hiddenapi/Android.bp
@@ -69,10 +69,37 @@
     },
 }
 
+python_library_host {
+    name: "signature_trie",
+    srcs: ["signature_trie.py"],
+}
+
+python_test_host {
+    name: "signature_trie_test",
+    main: "signature_trie_test.py",
+    srcs: ["signature_trie_test.py"],
+    libs: ["signature_trie"],
+    version: {
+        py2: {
+            enabled: false,
+        },
+        py3: {
+            enabled: true,
+            embedded_launcher: true,
+        },
+    },
+    test_options: {
+        unit_test: true,
+    },
+}
+
 python_binary_host {
     name: "verify_overlaps",
     main: "verify_overlaps.py",
     srcs: ["verify_overlaps.py"],
+    libs: [
+        "signature_trie",
+    ],
     version: {
         py2: {
             enabled: false,
@@ -91,6 +118,9 @@
         "verify_overlaps.py",
         "verify_overlaps_test.py",
     ],
+    libs: [
+        "signature_trie",
+    ],
     version: {
         py2: {
             enabled: false,
diff --git a/scripts/hiddenapi/signature_patterns.py b/scripts/hiddenapi/signature_patterns.py
index e75ee95..5a82be7 100755
--- a/scripts/hiddenapi/signature_patterns.py
+++ b/scripts/hiddenapi/signature_patterns.py
@@ -25,92 +25,138 @@
 import sys
 
 
-def dict_reader(csvfile):
+def dict_reader(csv_file):
     return csv.DictReader(
-        csvfile, delimiter=',', quotechar='|', fieldnames=['signature'])
+        csv_file, delimiter=',', quotechar='|', fieldnames=['signature'])
 
 
-def dotPackageToSlashPackage(pkg):
+def dot_package_to_slash_package(pkg):
     return pkg.replace('.', '/')
 
 
-def slashPackageToDotPackage(pkg):
+def dot_packages_to_slash_packages(pkgs):
+    return [dot_package_to_slash_package(p) for p in pkgs]
+
+
+def slash_package_to_dot_package(pkg):
     return pkg.replace('/', '.')
 
 
-def isSplitPackage(splitPackages, pkg):
-    return splitPackages and (pkg in splitPackages or '*' in splitPackages)
+def slash_packages_to_dot_packages(pkgs):
+    return [slash_package_to_dot_package(p) for p in pkgs]
 
 
-def matchedByPackagePrefixPattern(packagePrefixes, prefix):
-    for packagePrefix in packagePrefixes:
+def is_split_package(split_packages, pkg):
+    return split_packages and (pkg in split_packages or '*' in split_packages)
+
+
+def matched_by_package_prefix_pattern(package_prefixes, prefix):
+    for packagePrefix in package_prefixes:
         if prefix == packagePrefix:
             return packagePrefix
-        elif prefix.startswith(packagePrefix) and prefix[len(
-                packagePrefix)] == '/':
+        if (prefix.startswith(packagePrefix) and
+                prefix[len(packagePrefix)] == '/'):
             return packagePrefix
     return False
 
 
-def validate_package_prefixes(splitPackages, packagePrefixes):
+def validate_package_is_not_matched_by_package_prefix(package_type, pkg,
+                                                      package_prefixes):
+    package_prefix = matched_by_package_prefix_pattern(package_prefixes, pkg)
+    if package_prefix:
+        # A package prefix matches the package.
+        package_for_output = slash_package_to_dot_package(pkg)
+        package_prefix_for_output = slash_package_to_dot_package(package_prefix)
+        return [
+            f'{package_type} {package_for_output} is matched by '
+            f'package prefix {package_prefix_for_output}'
+        ]
+    return []
+
+
+def validate_package_prefixes(split_packages, single_packages,
+                              package_prefixes):
     # If there are no package prefixes then there is no possible conflict
     # between them and the split packages.
-    if len(packagePrefixes) == 0:
-        return
+    if len(package_prefixes) == 0:
+        return []
 
     # Check to make sure that the split packages and package prefixes do not
     # overlap.
     errors = []
-    for splitPackage in splitPackages:
-        if splitPackage == '*':
+    for split_package in split_packages:
+        if split_package == '*':
             # A package prefix matches a split package.
-            packagePrefixesForOutput = ', '.join(
-                map(slashPackageToDotPackage, packagePrefixes))
+            package_prefixes_for_output = ', '.join(
+                slash_packages_to_dot_packages(package_prefixes))
             errors.append(
-                'split package "*" conflicts with all package prefixes %s\n'
-                '    add split_packages:[] to fix' % packagePrefixesForOutput)
+                "split package '*' conflicts with all package prefixes "
+                f'{package_prefixes_for_output}\n'
+                '    add split_packages:[] to fix')
         else:
-            packagePrefix = matchedByPackagePrefixPattern(
-                packagePrefixes, splitPackage)
-            if packagePrefix:
-                # A package prefix matches a split package.
-                splitPackageForOutput = slashPackageToDotPackage(splitPackage)
-                packagePrefixForOutput = slashPackageToDotPackage(packagePrefix)
-                errors.append(
-                    'split package %s is matched by package prefix %s' %
-                    (splitPackageForOutput, packagePrefixForOutput))
+            errs = validate_package_is_not_matched_by_package_prefix(
+                'split package', split_package, package_prefixes)
+            errors.extend(errs)
+
+    # Check to make sure that the single packages and package prefixes do not
+    # overlap.
+    for single_package in single_packages:
+        errs = validate_package_is_not_matched_by_package_prefix(
+            'single package', single_package, package_prefixes)
+        errors.extend(errs)
     return errors
 
 
-def validate_split_packages(splitPackages):
+def validate_split_packages(split_packages):
     errors = []
-    if '*' in splitPackages and len(splitPackages) > 1:
+    if '*' in split_packages and len(split_packages) > 1:
         errors.append('split packages are invalid as they contain both the'
                       ' wildcard (*) and specific packages, use the wildcard or'
                       ' specific packages, not a mixture')
     return errors
 
 
-def produce_patterns_from_file(file, splitPackages=None, packagePrefixes=None):
-    with open(file, 'r') as f:
-        return produce_patterns_from_stream(f, splitPackages, packagePrefixes)
+def validate_single_packages(split_packages, single_packages):
+    overlaps = []
+    for single_package in single_packages:
+        if single_package in split_packages:
+            overlaps.append(single_package)
+    if overlaps:
+        indented = ''.join([f'\n    {o}' for o in overlaps])
+        return [
+            f'single_packages and split_packages overlap, please ensure the '
+            f'following packages are only present in one:{indented}'
+        ]
+    return []
+
+
+def produce_patterns_from_file(file,
+                               split_packages=None,
+                               single_packages=None,
+                               package_prefixes=None):
+    with open(file, 'r', encoding='utf8') as f:
+        return produce_patterns_from_stream(f, split_packages, single_packages,
+                                            package_prefixes)
 
 
 def produce_patterns_from_stream(stream,
-                                 splitPackages=None,
-                                 packagePrefixes=None):
-    splitPackages = set(splitPackages or [])
-    packagePrefixes = list(packagePrefixes or [])
+                                 split_packages=None,
+                                 single_packages=None,
+                                 package_prefixes=None):
+    split_packages = set(split_packages or [])
+    single_packages = set(single_packages or [])
+    package_prefixes = list(package_prefixes or [])
     # Read in all the signatures into a list and remove any unnecessary class
     # and member names.
     patterns = set()
+    unmatched_packages = set()
     for row in dict_reader(stream):
         signature = row['signature']
         text = signature.removeprefix('L')
         # Remove the class specific member signature
         pieces = text.split(';->')
-        qualifiedClassName = pieces[0]
-        pieces = qualifiedClassName.rsplit('/', maxsplit=1)
+        qualified_class_name = pieces[0]
+        pieces = qualified_class_name.rsplit('/', maxsplit=1)
         pkg = pieces[0]
         # If the package is split across multiple modules then it cannot be used
         # to select the subset of the monolithic flags that this module
@@ -121,27 +167,54 @@
         # If the package is not split then every class in the package must be
         # provided by this module so there is no need to list the classes
         # explicitly so just use the package name instead.
-        if isSplitPackage(splitPackages, pkg):
+        if is_split_package(split_packages, pkg):
             # Remove inner class names.
-            pieces = qualifiedClassName.split('$', maxsplit=1)
+            pieces = qualified_class_name.split('$', maxsplit=1)
             pattern = pieces[0]
-        else:
+            patterns.add(pattern)
+        elif pkg in single_packages:
             # Add a * to ensure that the pattern matches the classes in that
             # package.
             pattern = pkg + '/*'
-        patterns.add(pattern)
+            patterns.add(pattern)
+        else:
+            unmatched_packages.add(pkg)
+
+    # Remove any unmatched packages that would be matched by a package prefix
+    # pattern.
+    unmatched_packages = [
+        p for p in unmatched_packages
+        if not matched_by_package_prefix_pattern(package_prefixes, p)
+    ]
+    errors = []
+    if unmatched_packages:
+        unmatched_packages.sort()
+        indented = ''.join([
+            f'\n    {slash_package_to_dot_package(p)}'
+            for p in unmatched_packages
+        ])
+        errors.append('The following packages were unexpected, please add them '
+                      'to one of the hidden_api properties, split_packages, '
+                      f'single_packages or package_prefixes:{indented}')
 
     # Remove any patterns that would be matched by a package prefix pattern.
-    patterns = list(
-        filter(lambda p: not matchedByPackagePrefixPattern(packagePrefixes, p),
-               patterns))
+    patterns = [
+        p for p in patterns
+        if not matched_by_package_prefix_pattern(package_prefixes, p)
+    ]
     # Add the package prefix patterns to the list. Add a ** to ensure that each
     # package prefix pattern will match the classes in that package and all
     # sub-packages.
-    patterns = patterns + list(map(lambda x: x + '/**', packagePrefixes))
+    patterns = patterns + [f'{p}/**' for p in package_prefixes]
     # Sort the patterns.
     patterns.sort()
-    return patterns
+    return patterns, errors
+
+
+def print_and_exit(errors):
+    for error in errors:
+        print(error)
+    sys.exit(1)
 
 
 def main(args):
@@ -155,35 +228,50 @@
     args_parser.add_argument(
         '--split-package',
         action='append',
-        help='A package that is split across multiple bootclasspath_fragment modules'
-    )
+        help='A package that is split across multiple bootclasspath_fragment '
+        'modules')
     args_parser.add_argument(
         '--package-prefix',
         action='append',
         help='A package prefix unique to this set of flags')
+    args_parser.add_argument(
+        '--single-package',
+        action='append',
+        help='A single package unique to this set of flags')
     args_parser.add_argument('--output', help='Generated signature prefixes')
     args = args_parser.parse_args(args)
 
-    splitPackages = set(map(dotPackageToSlashPackage, args.split_package or []))
-    errors = validate_split_packages(splitPackages)
+    split_packages = set(
+        dot_packages_to_slash_packages(args.split_package or []))
+    errors = validate_split_packages(split_packages)
+    if errors:
+        print_and_exit(errors)
 
-    packagePrefixes = list(
-        map(dotPackageToSlashPackage, args.package_prefix or []))
+    single_packages = list(
+        dot_packages_to_slash_packages(args.single_package or []))
 
-    if not errors:
-        errors = validate_package_prefixes(splitPackages, packagePrefixes)
+    errors = validate_single_packages(split_packages, single_packages)
+    if errors:
+        print_and_exit(errors)
+
+    package_prefixes = dot_packages_to_slash_packages(args.package_prefix or [])
+
+    errors = validate_package_prefixes(split_packages, single_packages,
+                                       package_prefixes)
+    if errors:
+        print_and_exit(errors)
+
+    patterns = []
+    # Read in all the patterns into a list.
+    patterns, errors = produce_patterns_from_file(args.flags, split_packages,
+                                                  single_packages,
+                                                  package_prefixes)
 
     if errors:
-        for error in errors:
-            print(error)
-        sys.exit(1)
-
-    # Read in all the patterns into a list.
-    patterns = produce_patterns_from_file(args.flags, splitPackages,
-                                          packagePrefixes)
+        print_and_exit(errors)
 
     # Write out all the patterns.
-    with open(args.output, 'w') as outputFile:
+    with open(args.output, 'w', encoding='utf8') as outputFile:
         for pattern in patterns:
             outputFile.write(pattern)
             outputFile.write('\n')
diff --git a/scripts/hiddenapi/signature_patterns_test.py b/scripts/hiddenapi/signature_patterns_test.py
index b59dfd7..90b3d0b 100755
--- a/scripts/hiddenapi/signature_patterns_test.py
+++ b/scripts/hiddenapi/signature_patterns_test.py
@@ -17,37 +17,52 @@
 import io
 import unittest
 
-from signature_patterns import *  #pylint: disable=unused-wildcard-import,wildcard-import
+import signature_patterns
 
 
 class TestGeneratedPatterns(unittest.TestCase):
 
-    csvFlags = """
+    csv_flags = """
 Ljava/lang/ProcessBuilder$Redirect$1;-><init>()V,blocked
 Ljava/lang/Character$UnicodeScript;->of(I)Ljava/lang/Character$UnicodeScript;,public-api
 Ljava/lang/Object;->hashCode()I,public-api,system-api,test-api
 Ljava/lang/Object;->toString()Ljava/lang/String;,blocked
 """
 
-    def produce_patterns_from_string(self,
-                                     csv,
-                                     splitPackages=None,
-                                     packagePrefixes=None):
-        with io.StringIO(csv) as f:
-            return produce_patterns_from_stream(f, splitPackages,
-                                                packagePrefixes)
+    @staticmethod
+    def produce_patterns_from_string(csv_text,
+                                     split_packages=None,
+                                     single_packages=None,
+                                     package_prefixes=None):
+        with io.StringIO(csv_text) as f:
+            return signature_patterns.produce_patterns_from_stream(
+                f, split_packages, single_packages, package_prefixes)
+
+    def test_generate_unmatched(self):
+        _, errors = self.produce_patterns_from_string(
+            TestGeneratedPatterns.csv_flags)
+        self.assertEqual([
+            'The following packages were unexpected, please add them to one of '
+            'the hidden_api properties, split_packages, single_packages or '
+            'package_prefixes:\n'
+            '    java.lang'
+        ], errors)
 
     def test_generate_default(self):
-        patterns = self.produce_patterns_from_string(
-            TestGeneratedPatterns.csvFlags)
+        patterns, errors = self.produce_patterns_from_string(
+            TestGeneratedPatterns.csv_flags, single_packages=['java/lang'])
+        self.assertEqual([], errors)
+
         expected = [
             'java/lang/*',
         ]
         self.assertEqual(expected, patterns)
 
     def test_generate_split_package(self):
-        patterns = self.produce_patterns_from_string(
-            TestGeneratedPatterns.csvFlags, splitPackages={'java/lang'})
+        patterns, errors = self.produce_patterns_from_string(
+            TestGeneratedPatterns.csv_flags, split_packages={'java/lang'})
+        self.assertEqual([], errors)
+
         expected = [
             'java/lang/Character',
             'java/lang/Object',
@@ -56,8 +71,10 @@
         self.assertEqual(expected, patterns)
 
     def test_generate_split_package_wildcard(self):
-        patterns = self.produce_patterns_from_string(
-            TestGeneratedPatterns.csvFlags, splitPackages={'*'})
+        patterns, errors = self.produce_patterns_from_string(
+            TestGeneratedPatterns.csv_flags, split_packages={'*'})
+        self.assertEqual([], errors)
+
         expected = [
             'java/lang/Character',
             'java/lang/Object',
@@ -66,23 +83,27 @@
         self.assertEqual(expected, patterns)
 
     def test_generate_package_prefix(self):
-        patterns = self.produce_patterns_from_string(
-            TestGeneratedPatterns.csvFlags, packagePrefixes={'java/lang'})
+        patterns, errors = self.produce_patterns_from_string(
+            TestGeneratedPatterns.csv_flags, package_prefixes={'java/lang'})
+        self.assertEqual([], errors)
+
         expected = [
             'java/lang/**',
         ]
         self.assertEqual(expected, patterns)
 
     def test_generate_package_prefix_top_package(self):
-        patterns = self.produce_patterns_from_string(
-            TestGeneratedPatterns.csvFlags, packagePrefixes={'java'})
+        patterns, errors = self.produce_patterns_from_string(
+            TestGeneratedPatterns.csv_flags, package_prefixes={'java'})
+        self.assertEqual([], errors)
+
         expected = [
             'java/**',
         ]
         self.assertEqual(expected, patterns)
 
     def test_split_package_wildcard_conflicts_with_other_split_packages(self):
-        errors = validate_split_packages({'*', 'java'})
+        errors = signature_patterns.validate_split_packages({'*', 'java'})
         expected = [
             'split packages are invalid as they contain both the wildcard (*)'
             ' and specific packages, use the wildcard or specific packages,'
@@ -91,21 +112,39 @@
         self.assertEqual(expected, errors)
 
     def test_split_package_wildcard_conflicts_with_package_prefixes(self):
-        errors = validate_package_prefixes({'*'}, packagePrefixes={'java'})
+        errors = signature_patterns.validate_package_prefixes(
+            {'*'}, [], package_prefixes={'java'})
         expected = [
-            'split package "*" conflicts with all package prefixes java\n'
+            "split package '*' conflicts with all package prefixes java\n"
             '    add split_packages:[] to fix',
         ]
         self.assertEqual(expected, errors)
 
-    def test_split_package_conflict(self):
-        errors = validate_package_prefixes({'java/split'},
-                                           packagePrefixes={'java'})
+    def test_split_package_conflicts_with_package_prefixes(self):
+        errors = signature_patterns.validate_package_prefixes(
+            {'java/split'}, [], package_prefixes={'java'})
         expected = [
             'split package java.split is matched by package prefix java',
         ]
         self.assertEqual(expected, errors)
 
+    def test_single_package_conflicts_with_package_prefixes(self):
+        errors = signature_patterns.validate_package_prefixes(
+            {}, ['java/single'], package_prefixes={'java'})
+        expected = [
+            'single package java.single is matched by package prefix java',
+        ]
+        self.assertEqual(expected, errors)
+
+    def test_single_package_conflicts_with_split_packages(self):
+        errors = signature_patterns.validate_single_packages({'java/pkg'},
+                                                             ['java/pkg'])
+        expected = [
+            'single_packages and split_packages overlap, please ensure the '
+            'following packages are only present in one:\n    java/pkg'
+        ]
+        self.assertEqual(expected, errors)
+
 
 if __name__ == '__main__':
     unittest.main(verbosity=2)
diff --git a/scripts/hiddenapi/signature_trie.py b/scripts/hiddenapi/signature_trie.py
new file mode 100644
index 0000000..e813a97
--- /dev/null
+++ b/scripts/hiddenapi/signature_trie.py
@@ -0,0 +1,350 @@
+#!/usr/bin/env python
+#
+# 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.
+"""Verify that one set of hidden API flags is a subset of another."""
+import dataclasses
+import typing
+
+from itertools import chain
+
+
+@dataclasses.dataclass()
+class Node:
+    """A node in the signature trie."""
+
+    # The type of the node.
+    #
+    # Leaf nodes are of type "member".
+    # Interior nodes can be either "package", or "class".
+    type: str
+
+    # The selector of the node.
+    #
+    # That is a string that can be used to select the node, e.g. in a pattern
+    # that is passed to InteriorNode.get_matching_rows().
+    selector: str
+
+    def values(self, selector):
+        """Get the values from a set of selected nodes.
+
+        :param selector: a function that can be applied to a key in the nodes
+            attribute to determine whether to return its values.
+
+        :return: A list of iterables of all the values associated with
+            this node and its children.
+        """
+        raise NotImplementedError("Please Implement this method")
+
+    def append_values(self, values, selector):
+        """Append the values associated with this node and its children.
+
+        For each item (key, child) in nodes the child node's values are returned
+        if and only if the selector returns True when called on its key. A child
+        node's values are all the values associated with it and all its
+        descendant nodes.
+
+        :param selector: a function that can be applied to a key in the nodes
+        attribute to determine whether to return its values.
+        :param values: a list of a iterables of values.
+        """
+        raise NotImplementedError("Please Implement this method")
+
+    def child_nodes(self):
+        """Get an iterable of the child nodes of this node."""
+        raise NotImplementedError("Please Implement this method")
+
+
+# pylint: disable=line-too-long
+@dataclasses.dataclass()
+class InteriorNode(Node):
+    """An interior node in a trie.
+
+    Each interior node has a dict that maps from an element of a signature to
+    either another interior node or a leaf. Each interior node represents either
+    a package, class or nested class. Class members are represented by a Leaf.
+
+    Associating the set of flags [public-api] with the signature
+    "Ljava/lang/Object;->String()Ljava/lang/String;" will cause the following
+    nodes to be created:
+    Node()
+    ^- package:java -> Node()
+       ^- package:lang -> Node()
+           ^- class:Object -> Node()
+              ^- member:String()Ljava/lang/String; -> Leaf([public-api])
+
+    Associating the set of flags [blocked,core-platform-api] with the signature
+    "Ljava/lang/Character$UnicodeScript;->of(I)Ljava/lang/Character$UnicodeScript;"
+    will cause the following nodes to be created:
+    Node()
+    ^- package:java -> Node()
+       ^- package:lang -> Node()
+           ^- class:Character -> Node()
+              ^- class:UnicodeScript -> Node()
+                 ^- member:of(I)Ljava/lang/Character$UnicodeScript;
+                    -> Leaf([blocked,core-platform-api])
+    """
+
+    # pylint: enable=line-too-long
+
+    # A dict from an element of the signature to the Node/Leaf containing the
+    # next element/value.
+    nodes: typing.Dict[str, Node] = dataclasses.field(default_factory=dict)
+
+    # pylint: disable=line-too-long
+    @staticmethod
+    def signature_to_elements(signature):
+        """Split a signature or a prefix into a number of elements:
+
+        1. The packages (excluding the leading L preceding the first package).
+        2. The class names, from outermost to innermost.
+        3. The member signature.
+        e.g.
+        Ljava/lang/Character$UnicodeScript;->of(I)Ljava/lang/Character$UnicodeScript;
+        will be broken down into these elements:
+        1. package:java
+        2. package:lang
+        3. class:Character
+        4. class:UnicodeScript
+        5. member:of(I)Ljava/lang/Character$UnicodeScript;
+        """
+        # Remove the leading L.
+        #  - java/lang/Character$UnicodeScript;->of(I)Ljava/lang/Character$UnicodeScript;
+        text = signature.removeprefix("L")
+        # Split the signature between qualified class name and the class member
+        # signature.
+        #  0 - java/lang/Character$UnicodeScript
+        #  1 - of(I)Ljava/lang/Character$UnicodeScript;
+        parts = text.split(";->")
+        # If there is no member then this will be an empty list.
+        member = parts[1:]
+        # Split the qualified class name into packages, and class name.
+        #  0 - java
+        #  1 - lang
+        #  2 - Character$UnicodeScript
+        elements = parts[0].split("/")
+        last_element = elements[-1]
+        wildcard = []
+        classes = []
+        if "*" in last_element:
+            if last_element not in ("*", "**"):
+                raise Exception(f"Invalid signature '{signature}': invalid "
+                                f"wildcard '{last_element}'")
+            packages = elements[0:-1]
+            # Cannot specify a wildcard and target a specific member
+            if member:
+                raise Exception(f"Invalid signature '{signature}': contains "
+                                f"wildcard '{last_element}' and "
+                                f"member signature '{member[0]}'")
+            wildcard = [last_element]
+        elif last_element.islower():
+            raise Exception(f"Invalid signature '{signature}': last element "
+                            f"'{last_element}' is lower case but should be an "
+                            f"upper case class name or wildcard")
+        else:
+            packages = elements[0:-1]
+            # Split the class name into outer / inner classes
+            #  0 - Character
+            #  1 - UnicodeScript
+            classes = last_element.removesuffix(";").split("$")
+
+        # Assemble the parts into a single list, adding prefixes to identify
+        # the different parts. If a wildcard is provided then it looks something
+        # like this:
+        #  0 - package:java
+        #  1 - package:lang
+        #  2 - *
+        #
+        # Otherwise, it looks something like this:
+        #  0 - package:java
+        #  1 - package:lang
+        #  2 - class:Character
+        #  3 - class:UnicodeScript
+        #  4 - member:of(I)Ljava/lang/Character$UnicodeScript;
+        return list(
+            chain([("package", x) for x in packages],
+                  [("class", x) for x in classes],
+                  [("member", x) for x in member],
+                  [("wildcard", x) for x in wildcard]))
+
+    # pylint: enable=line-too-long
+
+    @staticmethod
+    def split_element(element):
+        element_type, element_value = element
+        return element_type, element_value
+
+    @staticmethod
+    def element_type(element):
+        element_type, _ = InteriorNode.split_element(element)
+        return element_type
+
+    @staticmethod
+    def elements_to_selector(elements):
+        """Compute a selector for a set of elements.
+
+        A selector uniquely identifies a specific Node in the trie. It is
+        essentially a prefix of a signature (without the leading L).
+
+        e.g. a trie containing "Ljava/lang/Object;->String()Ljava/lang/String;"
+        would contain nodes with the following selectors:
+        * "java"
+        * "java/lang"
+        * "java/lang/Object"
+        * "java/lang/Object;->String()Ljava/lang/String;"
+        """
+        signature = ""
+        preceding_type = ""
+        for element in elements:
+            element_type, element_value = InteriorNode.split_element(element)
+            separator = ""
+            if element_type == "package":
+                separator = "/"
+            elif element_type == "class":
+                if preceding_type == "class":
+                    separator = "$"
+                else:
+                    separator = "/"
+            elif element_type == "wildcard":
+                separator = "/"
+            elif element_type == "member":
+                separator += ";->"
+
+            if signature:
+                signature += separator
+
+            signature += element_value
+
+            preceding_type = element_type
+
+        return signature
+
+    def add(self, signature, value, only_if_matches=False):
+        """Associate the value with the specific signature.
+
+        :param signature: the member signature
+        :param value: the value to associated with the signature
+        :param only_if_matches: True if the value is added only if the signature
+             matches at least one of the existing top level packages.
+        :return: n/a
+        """
+        # Split the signature into elements.
+        elements = self.signature_to_elements(signature)
+        # Find the Node associated with the deepest class.
+        node = self
+        for index, element in enumerate(elements[:-1]):
+            if element in node.nodes:
+                node = node.nodes[element]
+            elif only_if_matches and index == 0:
+                return
+            else:
+                selector = self.elements_to_selector(elements[0:index + 1])
+                next_node = InteriorNode(
+                    type=InteriorNode.element_type(element), selector=selector)
+                node.nodes[element] = next_node
+                node = next_node
+        # Add a Leaf containing the value and associate it with the member
+        # signature within the class.
+        last_element = elements[-1]
+        last_element_type = self.element_type(last_element)
+        if last_element_type != "member":
+            raise Exception(
+                f"Invalid signature: {signature}, does not identify a "
+                "specific member")
+        if last_element in node.nodes:
+            raise Exception(f"Duplicate signature: {signature}")
+        leaf = Leaf(
+            type=last_element_type,
+            selector=signature,
+            value=value,
+        )
+        node.nodes[last_element] = leaf
+
+    def get_matching_rows(self, pattern):
+        """Get the values (plural) associated with the pattern.
+
+        e.g. If the pattern is a full signature then this will return a list
+        containing the value associated with that signature.
+
+        If the pattern is a class then this will return a list containing the
+        values associated with all members of that class.
+
+        If the pattern ends with "*" then the preceding part is treated as a
+        package and this will return a list containing the values associated
+        with all the members of all the classes in that package.
+
+        If the pattern ends with "**" then the preceding part is treated
+        as a package and this will return a list containing the values
+        associated with all the members of all the classes in that package and
+        all sub-packages.
+
+        :param pattern: the pattern which could be a complete signature or a
+        class, or package wildcard.
+        :return: an iterable containing all the values associated with the
+        pattern.
+        """
+        elements = self.signature_to_elements(pattern)
+        node = self
+
+        # Include all values from this node and all its children.
+        selector = lambda x: True
+
+        last_element = elements[-1]
+        last_element_type, last_element_value = self.split_element(last_element)
+        if last_element_type == "wildcard":
+            elements = elements[:-1]
+            if last_element_value == "*":
+                # Do not include values from sub-packages.
+                selector = lambda x: InteriorNode.element_type(x) != "package"
+
+        for element in elements:
+            if element in node.nodes:
+                node = node.nodes[element]
+            else:
+                return []
+        return chain.from_iterable(node.values(selector))
+
+    def values(self, selector):
+        values = []
+        self.append_values(values, selector)
+        return values
+
+    def append_values(self, values, selector):
+        for key, node in self.nodes.items():
+            if selector(key):
+                node.append_values(values, lambda x: True)
+
+    def child_nodes(self):
+        return self.nodes.values()
+
+
+@dataclasses.dataclass()
+class Leaf(Node):
+    """A leaf of the trie"""
+
+    # The value associated with this leaf.
+    value: typing.Any
+
+    def values(self, selector):
+        return [[self.value]]
+
+    def append_values(self, values, selector):
+        values.append([self.value])
+
+    def child_nodes(self):
+        return []
+
+
+def signature_trie():
+    return InteriorNode(type="root", selector="")
diff --git a/scripts/hiddenapi/signature_trie_test.py b/scripts/hiddenapi/signature_trie_test.py
new file mode 100755
index 0000000..1295691
--- /dev/null
+++ b/scripts/hiddenapi/signature_trie_test.py
@@ -0,0 +1,232 @@
+#!/usr/bin/env python
+#
+# 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.
+"""Unit tests for verify_overlaps_test.py."""
+import io
+import unittest
+
+from signature_trie import InteriorNode
+from signature_trie import signature_trie
+
+
+class TestSignatureToElements(unittest.TestCase):
+
+    @staticmethod
+    def signature_to_elements(signature):
+        return InteriorNode.signature_to_elements(signature)
+
+    @staticmethod
+    def elements_to_signature(elements):
+        return InteriorNode.elements_to_selector(elements)
+
+    def test_nested_inner_classes(self):
+        elements = [
+            ("package", "java"),
+            ("package", "lang"),
+            ("class", "ProcessBuilder"),
+            ("class", "Redirect"),
+            ("class", "1"),
+            ("member", "<init>()V"),
+        ]
+        signature = "Ljava/lang/ProcessBuilder$Redirect$1;-><init>()V"
+        self.assertEqual(elements, self.signature_to_elements(signature))
+        self.assertEqual(signature, "L" + self.elements_to_signature(elements))
+
+    def test_basic_member(self):
+        elements = [
+            ("package", "java"),
+            ("package", "lang"),
+            ("class", "Object"),
+            ("member", "hashCode()I"),
+        ]
+        signature = "Ljava/lang/Object;->hashCode()I"
+        self.assertEqual(elements, self.signature_to_elements(signature))
+        self.assertEqual(signature, "L" + self.elements_to_signature(elements))
+
+    def test_double_dollar_class(self):
+        elements = [
+            ("package", "java"),
+            ("package", "lang"),
+            ("class", "CharSequence"),
+            ("class", ""),
+            ("class", "ExternalSyntheticLambda0"),
+            ("member", "<init>(Ljava/lang/CharSequence;)V"),
+        ]
+        signature = "Ljava/lang/CharSequence$$ExternalSyntheticLambda0;" \
+                    "-><init>(Ljava/lang/CharSequence;)V"
+        self.assertEqual(elements, self.signature_to_elements(signature))
+        self.assertEqual(signature, "L" + self.elements_to_signature(elements))
+
+    def test_no_member(self):
+        elements = [
+            ("package", "java"),
+            ("package", "lang"),
+            ("class", "CharSequence"),
+            ("class", ""),
+            ("class", "ExternalSyntheticLambda0"),
+        ]
+        signature = "Ljava/lang/CharSequence$$ExternalSyntheticLambda0"
+        self.assertEqual(elements, self.signature_to_elements(signature))
+        self.assertEqual(signature, "L" + self.elements_to_signature(elements))
+
+    def test_wildcard(self):
+        elements = [
+            ("package", "java"),
+            ("package", "lang"),
+            ("wildcard", "*"),
+        ]
+        signature = "java/lang/*"
+        self.assertEqual(elements, self.signature_to_elements(signature))
+        self.assertEqual(signature, self.elements_to_signature(elements))
+
+    def test_recursive_wildcard(self):
+        elements = [
+            ("package", "java"),
+            ("package", "lang"),
+            ("wildcard", "**"),
+        ]
+        signature = "java/lang/**"
+        self.assertEqual(elements, self.signature_to_elements(signature))
+        self.assertEqual(signature, self.elements_to_signature(elements))
+
+    def test_no_packages_wildcard(self):
+        elements = [
+            ("wildcard", "*"),
+        ]
+        signature = "*"
+        self.assertEqual(elements, self.signature_to_elements(signature))
+        self.assertEqual(signature, self.elements_to_signature(elements))
+
+    def test_no_packages_recursive_wildcard(self):
+        elements = [
+            ("wildcard", "**"),
+        ]
+        signature = "**"
+        self.assertEqual(elements, self.signature_to_elements(signature))
+        self.assertEqual(signature, self.elements_to_signature(elements))
+
+    def test_invalid_no_class_or_wildcard(self):
+        signature = "java/lang"
+        with self.assertRaises(Exception) as context:
+            self.signature_to_elements(signature)
+        self.assertIn(
+            "last element 'lang' is lower case but should be an "
+            "upper case class name or wildcard", str(context.exception))
+
+    def test_non_standard_class_name(self):
+        elements = [
+            ("package", "javax"),
+            ("package", "crypto"),
+            ("class", "extObjectInputStream"),
+        ]
+        signature = "Ljavax/crypto/extObjectInputStream"
+        self.assertEqual(elements, self.signature_to_elements(signature))
+        self.assertEqual(signature, "L" + self.elements_to_signature(elements))
+
+    def test_invalid_pattern_wildcard(self):
+        pattern = "Ljava/lang/Class*"
+        with self.assertRaises(Exception) as context:
+            self.signature_to_elements(pattern)
+        self.assertIn("invalid wildcard 'Class*'", str(context.exception))
+
+    def test_invalid_pattern_wildcard_and_member(self):
+        pattern = "Ljava/lang/*;->hashCode()I"
+        with self.assertRaises(Exception) as context:
+            self.signature_to_elements(pattern)
+        self.assertIn(
+            "contains wildcard '*' and member signature 'hashCode()I'",
+            str(context.exception))
+
+
+class TestGetMatchingRows(unittest.TestCase):
+    extractInput = """
+Ljava/lang/Character$UnicodeScript;->of(I)Ljava/lang/Character$UnicodeScript;
+Ljava/lang/Character;->serialVersionUID:J
+Ljava/lang/Object;->hashCode()I
+Ljava/lang/Object;->toString()Ljava/lang/String;
+Ljava/lang/ProcessBuilder$Redirect$1;-><init>()V
+Ljava/util/zip/ZipFile;-><clinit>()V
+"""
+
+    def read_trie(self):
+        trie = signature_trie()
+        with io.StringIO(self.extractInput.strip()) as f:
+            for line in iter(f.readline, ""):
+                line = line.rstrip()
+                trie.add(line, line)
+        return trie
+
+    def check_patterns(self, pattern, expected):
+        trie = self.read_trie()
+        self.check_node_patterns(trie, pattern, expected)
+
+    def check_node_patterns(self, node, pattern, expected):
+        actual = list(node.get_matching_rows(pattern))
+        actual.sort()
+        self.assertEqual(expected, actual)
+
+    def test_member_pattern(self):
+        self.check_patterns("java/util/zip/ZipFile;-><clinit>()V",
+                            ["Ljava/util/zip/ZipFile;-><clinit>()V"])
+
+    def test_class_pattern(self):
+        self.check_patterns("java/lang/Object", [
+            "Ljava/lang/Object;->hashCode()I",
+            "Ljava/lang/Object;->toString()Ljava/lang/String;",
+        ])
+
+    # pylint: disable=line-too-long
+    def test_nested_class_pattern(self):
+        self.check_patterns("java/lang/Character", [
+            "Ljava/lang/Character$UnicodeScript;->of(I)Ljava/lang/Character$UnicodeScript;",
+            "Ljava/lang/Character;->serialVersionUID:J",
+        ])
+
+    def test_wildcard(self):
+        self.check_patterns("java/lang/*", [
+            "Ljava/lang/Character$UnicodeScript;->of(I)Ljava/lang/Character$UnicodeScript;",
+            "Ljava/lang/Character;->serialVersionUID:J",
+            "Ljava/lang/Object;->hashCode()I",
+            "Ljava/lang/Object;->toString()Ljava/lang/String;",
+            "Ljava/lang/ProcessBuilder$Redirect$1;-><init>()V",
+        ])
+
+    def test_recursive_wildcard(self):
+        self.check_patterns("java/**", [
+            "Ljava/lang/Character$UnicodeScript;->of(I)Ljava/lang/Character$UnicodeScript;",
+            "Ljava/lang/Character;->serialVersionUID:J",
+            "Ljava/lang/Object;->hashCode()I",
+            "Ljava/lang/Object;->toString()Ljava/lang/String;",
+            "Ljava/lang/ProcessBuilder$Redirect$1;-><init>()V",
+            "Ljava/util/zip/ZipFile;-><clinit>()V",
+        ])
+
+    def test_node_wildcard(self):
+        trie = self.read_trie()
+        node = list(trie.child_nodes())[0]
+        self.check_node_patterns(node, "**", [
+            "Ljava/lang/Character$UnicodeScript;->of(I)Ljava/lang/Character$UnicodeScript;",
+            "Ljava/lang/Character;->serialVersionUID:J",
+            "Ljava/lang/Object;->hashCode()I",
+            "Ljava/lang/Object;->toString()Ljava/lang/String;",
+            "Ljava/lang/ProcessBuilder$Redirect$1;-><init>()V",
+            "Ljava/util/zip/ZipFile;-><clinit>()V",
+        ])
+
+    # pylint: enable=line-too-long
+
+
+if __name__ == "__main__":
+    unittest.main(verbosity=2)
diff --git a/scripts/hiddenapi/verify_overlaps.py b/scripts/hiddenapi/verify_overlaps.py
index 4cd7e63..e5214df 100755
--- a/scripts/hiddenapi/verify_overlaps.py
+++ b/scripts/hiddenapi/verify_overlaps.py
@@ -13,239 +13,14 @@
 # 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.
-"""Verify that one set of hidden API flags is a subset of another.
-"""
+"""Verify that one set of hidden API flags is a subset of another."""
 
 import argparse
 import csv
 import sys
 from itertools import chain
 
-#pylint: disable=line-too-long
-class InteriorNode:
-    """An interior node in a trie.
-
-    Each interior node has a dict that maps from an element of a signature to
-    either another interior node or a leaf. Each interior node represents either
-    a package, class or nested class. Class members are represented by a Leaf.
-
-    Associating the set of flags [public-api] with the signature
-    "Ljava/lang/Object;->String()Ljava/lang/String;" will cause the following
-    nodes to be created:
-    Node()
-    ^- package:java -> Node()
-       ^- package:lang -> Node()
-           ^- class:Object -> Node()
-              ^- member:String()Ljava/lang/String; -> Leaf([public-api])
-
-    Associating the set of flags [blocked,core-platform-api] with the signature
-    "Ljava/lang/Character$UnicodeScript;->of(I)Ljava/lang/Character$UnicodeScript;"
-    will cause the following nodes to be created:
-    Node()
-    ^- package:java -> Node()
-       ^- package:lang -> Node()
-           ^- class:Character -> Node()
-              ^- class:UnicodeScript -> Node()
-                 ^- member:of(I)Ljava/lang/Character$UnicodeScript;
-                    -> Leaf([blocked,core-platform-api])
-
-    Attributes:
-        nodes: a dict from an element of the signature to the Node/Leaf
-          containing the next element/value.
-    """
-    #pylint: enable=line-too-long
-
-    def __init__(self):
-        self.nodes = {}
-
-    #pylint: disable=line-too-long
-    def signatureToElements(self, signature):
-        """Split a signature or a prefix into a number of elements:
-        1. The packages (excluding the leading L preceding the first package).
-        2. The class names, from outermost to innermost.
-        3. The member signature.
-        e.g.
-        Ljava/lang/Character$UnicodeScript;->of(I)Ljava/lang/Character$UnicodeScript;
-        will be broken down into these elements:
-        1. package:java
-        2. package:lang
-        3. class:Character
-        4. class:UnicodeScript
-        5. member:of(I)Ljava/lang/Character$UnicodeScript;
-        """
-        # Remove the leading L.
-        #  - java/lang/Character$UnicodeScript;->of(I)Ljava/lang/Character$UnicodeScript;
-        text = signature.removeprefix("L")
-        # Split the signature between qualified class name and the class member
-        # signature.
-        #  0 - java/lang/Character$UnicodeScript
-        #  1 - of(I)Ljava/lang/Character$UnicodeScript;
-        parts = text.split(";->")
-        member = parts[1:]
-        # Split the qualified class name into packages, and class name.
-        #  0 - java
-        #  1 - lang
-        #  2 - Character$UnicodeScript
-        elements = parts[0].split("/")
-        packages = elements[0:-1]
-        className = elements[-1]
-        if className in ("*" , "**"): #pylint: disable=no-else-return
-            # Cannot specify a wildcard and target a specific member
-            if len(member) != 0:
-                raise Exception(
-                    "Invalid signature %s: contains wildcard %s and member " \
-                    "signature %s"
-                    % (signature, className, member[0]))
-            wildcard = [className]
-            # Assemble the parts into a single list, adding prefixes to identify
-            # the different parts.
-            #  0 - package:java
-            #  1 - package:lang
-            #  2 - *
-            return list(
-                chain(["package:" + x for x in packages], wildcard))
-        else:
-            # Split the class name into outer / inner classes
-            #  0 - Character
-            #  1 - UnicodeScript
-            classes = className.split("$")
-            # Assemble the parts into a single list, adding prefixes to identify
-            # the different parts.
-            #  0 - package:java
-            #  1 - package:lang
-            #  2 - class:Character
-            #  3 - class:UnicodeScript
-            #  4 - member:of(I)Ljava/lang/Character$UnicodeScript;
-            return list(
-                chain(
-                    ["package:" + x for x in packages],
-                    ["class:" + x for x in classes],
-                    ["member:" + x for x in member]))
-    #pylint: enable=line-too-long
-
-    def add(self, signature, value):
-        """Associate the value with the specific signature.
-
-        :param signature: the member signature
-        :param value: the value to associated with the signature
-        :return: n/a
-        """
-        # Split the signature into elements.
-        elements = self.signatureToElements(signature)
-        # Find the Node associated with the deepest class.
-        node = self
-        for element in elements[:-1]:
-            if element in node.nodes:
-                node = node.nodes[element]
-            else:
-                next_node = InteriorNode()
-                node.nodes[element] = next_node
-                node = next_node
-        # Add a Leaf containing the value and associate it with the member
-        # signature within the class.
-        lastElement = elements[-1]
-        if not lastElement.startswith("member:"):
-            raise Exception(
-                "Invalid signature: %s, does not identify a specific member" %
-                signature)
-        if lastElement in node.nodes:
-            raise Exception("Duplicate signature: %s" % signature)
-        node.nodes[lastElement] = Leaf(value)
-
-    def getMatchingRows(self, pattern):
-        """Get the values (plural) associated with the pattern.
-
-        e.g. If the pattern is a full signature then this will return a list
-        containing the value associated with that signature.
-
-        If the pattern is a class then this will return a list containing the
-        values associated with all members of that class.
-
-        If the pattern is a package then this will return a list containing the
-        values associated with all the members of all the classes in that
-        package and sub-packages.
-
-        If the pattern ends with "*" then the preceding part is treated as a
-        package and this will return a list containing the values associated
-        with all the members of all the classes in that package.
-
-        If the pattern ends with "**" then the preceding part is treated
-        as a package and this will return a list containing the values
-        associated with all the members of all the classes in that package and
-        all sub-packages.
-
-        :param pattern: the pattern which could be a complete signature or a
-        class, or package wildcard.
-        :return: an iterable containing all the values associated with the
-        pattern.
-        """
-        elements = self.signatureToElements(pattern)
-        node = self
-        # Include all values from this node and all its children.
-        selector = lambda x: True
-        lastElement = elements[-1]
-        if lastElement in ("*", "**"):
-            elements = elements[:-1]
-            if lastElement == "*":
-                # Do not include values from sub-packages.
-                selector = lambda x: not x.startswith("package:")
-        for element in elements:
-            if element in node.nodes:
-                node = node.nodes[element]
-            else:
-                return []
-        return chain.from_iterable(node.values(selector))
-
-    def values(self, selector):
-        """:param selector: a function that can be applied to a key in the nodes
-        attribute to determine whether to return its values.
-
-        :return: A list of iterables of all the values associated with
-        this node and its children.
-        """
-        values = []
-        self.appendValues(values, selector)
-        return values
-
-    def appendValues(self, values, selector):
-        """Append the values associated with this node and its children to the
-        list.
-
-        For each item (key, child) in nodes the child node's values are returned
-        if and only if the selector returns True when called on its key. A child
-        node's values are all the values associated with it and all its
-        descendant nodes.
-
-        :param selector: a function that can be applied to a key in the nodes
-        attribute to determine whether to return its values.
-        :param values: a list of a iterables of values.
-        """
-        for key, node in self.nodes.items():
-            if selector(key):
-                node.appendValues(values, lambda x: True)
-
-
-class Leaf:
-    """A leaf of the trie
-
-    Attributes:
-        value: the value associated with this leaf.
-    """
-
-    def __init__(self, value):
-        self.value = value
-
-    def values(self, selector): #pylint: disable=unused-argument
-        """:return: A list of a list of the value associated with this node.
-        """
-        return [[self.value]]
-
-    def appendValues(self, values, selector): #pylint: disable=unused-argument
-        """Appends a list of the value associated with this node to the list.
-
-        :param values: a list of a iterables of values.
-        """
-        values.append([self.value])
+from signature_trie import signature_trie
 
 
 def dict_reader(csvfile):
@@ -259,7 +34,7 @@
 
 
 def read_flag_trie_from_stream(stream):
-    trie = InteriorNode()
+    trie = signature_trie()
     reader = dict_reader(stream)
     for row in reader:
         signature = row["signature"]
@@ -269,8 +44,7 @@
 
 def extract_subset_from_monolithic_flags_as_dict_from_file(
         monolithicTrie, patternsFile):
-    """Extract a subset of flags from the dict containing all the monolithic
-    flags.
+    """Extract a subset of flags from the dict of monolithic flags.
 
     :param monolithicFlagsDict: the dict containing all the monolithic flags.
     :param patternsFile: a file containing a list of signature patterns that
@@ -284,8 +58,7 @@
 
 def extract_subset_from_monolithic_flags_as_dict_from_stream(
         monolithicTrie, stream):
-    """Extract a subset of flags from the trie containing all the monolithic
-    flags.
+    """Extract a subset of flags from the trie of monolithic flags.
 
     :param monolithicTrie: the trie containing all the monolithic flags.
     :param stream: a stream containing a list of signature patterns that define
@@ -295,7 +68,7 @@
     dict_signature_to_row = {}
     for pattern in stream:
         pattern = pattern.rstrip()
-        rows = monolithicTrie.getMatchingRows(pattern)
+        rows = monolithicTrie.get_matching_rows(pattern)
         for row in rows:
             signature = row["signature"]
             dict_signature_to_row[signature] = row
@@ -303,8 +76,10 @@
 
 
 def read_signature_csv_from_stream_as_dict(stream):
-    """Read the csv contents from the stream into a dict. The first column is
-    assumed to be the signature and used as the key.
+    """Read the csv contents from the stream into a dict.
+
+    The first column is assumed to be the signature and used as the
+    key.
 
     The whole row is stored as the value.
     :param stream: the csv contents to read
@@ -319,8 +94,10 @@
 
 
 def read_signature_csv_from_file_as_dict(csvFile):
-    """Read the csvFile into a dict. The first column is assumed to be the
-    signature and used as the key.
+    """Read the csvFile into a dict.
+
+    The first column is assumed to be the signature and used as the
+    key.
 
     The whole row is stored as the value.
     :param csvFile: the csv file to read
@@ -363,8 +140,7 @@
 def main(argv):
     args_parser = argparse.ArgumentParser(
         description="Verify that sets of hidden API flags are each a subset of "
-        "the monolithic flag file."
-    )
+        "the monolithic flag file.")
     args_parser.add_argument("monolithicFlags", help="The monolithic flag file")
     args_parser.add_argument(
         "modularFlags",
diff --git a/scripts/hiddenapi/verify_overlaps_test.py b/scripts/hiddenapi/verify_overlaps_test.py
index 22a1cdf..8cf2959 100755
--- a/scripts/hiddenapi/verify_overlaps_test.py
+++ b/scripts/hiddenapi/verify_overlaps_test.py
@@ -17,54 +17,9 @@
 import io
 import unittest
 
-from verify_overlaps import * #pylint: disable=unused-wildcard-import,wildcard-import
+from verify_overlaps import *  #pylint: disable=unused-wildcard-import,wildcard-import
 
 
-class TestSignatureToElements(unittest.TestCase):
-
-    def signatureToElements(self, signature):
-        return InteriorNode().signatureToElements(signature)
-
-    def test_signatureToElements_1(self):
-        expected = [
-            'package:java',
-            'package:lang',
-            'class:ProcessBuilder',
-            'class:Redirect',
-            'class:1',
-            'member:<init>()V',
-        ]
-        self.assertEqual(
-            expected,
-            self.signatureToElements(
-                'Ljava/lang/ProcessBuilder$Redirect$1;-><init>()V'))
-
-    def test_signatureToElements_2(self):
-        expected = [
-            'package:java',
-            'package:lang',
-            'class:Object',
-            'member:hashCode()I',
-        ]
-        self.assertEqual(
-            expected,
-            self.signatureToElements('Ljava/lang/Object;->hashCode()I'))
-
-    def test_signatureToElements_3(self):
-        expected = [
-            'package:java',
-            'package:lang',
-            'class:CharSequence',
-            'class:',
-            'class:ExternalSyntheticLambda0',
-            'member:<init>(Ljava/lang/CharSequence;)V',
-        ]
-        self.assertEqual(
-            expected,
-            self.signatureToElements(
-                'Ljava/lang/CharSequence$$ExternalSyntheticLambda0;'
-                '-><init>(Ljava/lang/CharSequence;)V'))
-
 #pylint: disable=line-too-long
 class TestDetectOverlaps(unittest.TestCase):
 
@@ -239,18 +194,6 @@
         }
         self.assertEqual(expected, subset)
 
-    def test_extract_subset_invalid_pattern_wildcard_and_member(self):
-        monolithic = self.read_flag_trie_from_string(
-            TestDetectOverlaps.extractInput)
-
-        patterns = 'Ljava/lang/*;->hashCode()I'
-
-        with self.assertRaises(Exception) as context:
-            self.extract_subset_from_monolithic_flags_as_dict_from_string(
-                monolithic, patterns)
-        self.assertTrue('contains wildcard * and member signature hashCode()I'
-                        in str(context.exception))
-
     def test_read_trie_duplicate(self):
         with self.assertRaises(Exception) as context:
             self.read_flag_trie_from_string("""
@@ -369,6 +312,8 @@
         mismatches = compare_signature_flags(monolithic, modular)
         expected = []
         self.assertEqual(expected, mismatches)
+
+
 #pylint: enable=line-too-long
 
 if __name__ == '__main__':
diff --git a/ui/build/config.go b/ui/build/config.go
index 077a4d1..01fe8fa 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -368,10 +368,14 @@
 	java8Home := filepath.Join("prebuilts/jdk/jdk8", ret.HostPrebuiltTag())
 	java9Home := filepath.Join("prebuilts/jdk/jdk9", ret.HostPrebuiltTag())
 	java11Home := filepath.Join("prebuilts/jdk/jdk11", ret.HostPrebuiltTag())
+	java17Home := filepath.Join("prebuilts/jdk/jdk17", ret.HostPrebuiltTag())
 	javaHome := func() string {
 		if override, ok := ret.environ.Get("OVERRIDE_ANDROID_JAVA_HOME"); ok {
 			return override
 		}
+		if ret.environ.IsEnvTrue("EXPERIMENTAL_USE_OPENJDK17_TOOLCHAIN") {
+			return java17Home
+		}
 		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.")
 		}