Merge "Revert "Annotate dependency tags for dependencies of installed files""
diff --git a/android/apex.go b/android/apex.go
index e70ec4f..276f7a4 100644
--- a/android/apex.go
+++ b/android/apex.go
@@ -598,36 +598,22 @@
 	var fullContent strings.Builder
 	var flatContent strings.Builder
 
-	fmt.Fprintf(&fullContent, "%s(minSdkVersion:%s):\\n", ctx.ModuleName(), minSdkVersion)
+	fmt.Fprintf(&fullContent, "%s(minSdkVersion:%s):\n", ctx.ModuleName(), minSdkVersion)
 	for _, key := range FirstUniqueStrings(SortedStringKeys(depInfos)) {
 		info := depInfos[key]
 		toName := fmt.Sprintf("%s(minSdkVersion:%s)", info.To, info.MinSdkVersion)
 		if info.IsExternal {
 			toName = toName + " (external)"
 		}
-		fmt.Fprintf(&fullContent, "  %s <- %s\\n", toName, strings.Join(SortedUniqueStrings(info.From), ", "))
-		fmt.Fprintf(&flatContent, "%s\\n", toName)
+		fmt.Fprintf(&fullContent, "  %s <- %s\n", toName, strings.Join(SortedUniqueStrings(info.From), ", "))
+		fmt.Fprintf(&flatContent, "%s\n", toName)
 	}
 
 	d.fullListPath = PathForModuleOut(ctx, "depsinfo", "fulllist.txt").OutputPath
-	ctx.Build(pctx, BuildParams{
-		Rule:        WriteFile,
-		Description: "Full Dependency Info",
-		Output:      d.fullListPath,
-		Args: map[string]string{
-			"content": fullContent.String(),
-		},
-	})
+	WriteFileRule(ctx, d.fullListPath, fullContent.String())
 
 	d.flatListPath = PathForModuleOut(ctx, "depsinfo", "flatlist.txt").OutputPath
-	ctx.Build(pctx, BuildParams{
-		Rule:        WriteFile,
-		Description: "Flat Dependency Info",
-		Output:      d.flatListPath,
-		Args: map[string]string{
-			"content": flatContent.String(),
-		},
-	})
+	WriteFileRule(ctx, d.flatListPath, flatContent.String())
 }
 
 // TODO(b/158059172): remove minSdkVersion allowlist
diff --git a/android/api_levels.go b/android/api_levels.go
index bace3d4..08328e1 100644
--- a/android/api_levels.go
+++ b/android/api_levels.go
@@ -225,14 +225,7 @@
 		ctx.Errorf(err.Error())
 	}
 
-	ctx.Build(pctx, BuildParams{
-		Rule:        WriteFile,
-		Description: "generate " + file.Base(),
-		Output:      file,
-		Args: map[string]string{
-			"content": string(jsonStr[:]),
-		},
-	})
+	WriteFileRule(ctx, file, string(jsonStr))
 }
 
 func GetApiLevelsJson(ctx PathContext) WritablePath {
diff --git a/android/defs.go b/android/defs.go
index 2b1bd85..631dfe8 100644
--- a/android/defs.go
+++ b/android/defs.go
@@ -15,8 +15,12 @@
 package android
 
 import (
+	"strings"
+	"testing"
+
 	"github.com/google/blueprint"
 	_ "github.com/google/blueprint/bootstrap"
+	"github.com/google/blueprint/proptools"
 )
 
 var (
@@ -91,9 +95,9 @@
 	// ubuntu 14.04 offcially use dash for /bin/sh, and its builtin echo command
 	// doesn't support -e option. Therefore we force to use /bin/bash when writing out
 	// content to file.
-	WriteFile = pctx.AndroidStaticRule("WriteFile",
+	writeFile = pctx.AndroidStaticRule("writeFile",
 		blueprint.RuleParams{
-			Command:     "/bin/bash -c 'echo -e $$0 > $out' '$content'",
+			Command:     `/bin/bash -c 'echo -e "$$0" > $out' $content`,
 			Description: "writing file $out",
 		},
 		"content")
@@ -111,3 +115,64 @@
 func init() {
 	pctx.Import("github.com/google/blueprint/bootstrap")
 }
+
+var (
+	// echoEscaper escapes a string such that passing it to "echo -e" will produce the input value.
+	echoEscaper = strings.NewReplacer(
+		`\`, `\\`, // First escape existing backslashes so they aren't interpreted by `echo -e`.
+		"\n", `\n`, // Then replace newlines with \n
+	)
+
+	// echoEscaper reverses echoEscaper.
+	echoUnescaper = strings.NewReplacer(
+		`\n`, "\n",
+		`\\`, `\`,
+	)
+
+	// shellUnescaper reverses the replacer in proptools.ShellEscape
+	shellUnescaper = strings.NewReplacer(`'\''`, `'`)
+)
+
+// WriteFileRule creates a ninja rule to write contents to a file.  The contents will be escaped
+// so that the file contains exactly the contents passed to the function, plus a trailing newline.
+func WriteFileRule(ctx BuilderContext, outputFile WritablePath, content string) {
+	content = echoEscaper.Replace(content)
+	content = proptools.ShellEscape(content)
+	if content == "" {
+		content = "''"
+	}
+	ctx.Build(pctx, BuildParams{
+		Rule:        writeFile,
+		Output:      outputFile,
+		Description: "write " + outputFile.Base(),
+		Args: map[string]string{
+			"content": content,
+		},
+	})
+}
+
+// shellUnescape reverses proptools.ShellEscape
+func shellUnescape(s string) string {
+	// Remove leading and trailing quotes if present
+	if len(s) >= 2 && s[0] == '\'' {
+		s = s[1 : len(s)-1]
+	}
+	s = shellUnescaper.Replace(s)
+	return s
+}
+
+// ContentFromFileRuleForTests returns the content that was passed to a WriteFileRule for use
+// in tests.
+func ContentFromFileRuleForTests(t *testing.T, params TestingBuildParams) string {
+	t.Helper()
+	if g, w := params.Rule, writeFile; g != w {
+		t.Errorf("expected params.Rule to be %q, was %q", w, g)
+		return ""
+	}
+
+	content := params.Args["content"]
+	content = shellUnescape(content)
+	content = echoUnescaper.Replace(content)
+
+	return content
+}
diff --git a/apex/apex.go b/apex/apex.go
index 8268966..91770f4 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -63,7 +63,6 @@
 	testTag        = dependencyTag{name: "test", payload: true}
 	keyTag         = dependencyTag{name: "key"}
 	certificateTag = dependencyTag{name: "certificate"}
-	usesTag        = dependencyTag{name: "uses"}
 	androidAppTag  = dependencyTag{name: "androidApp", payload: true}
 	rroTag         = dependencyTag{name: "rro", payload: true}
 	bpfTag         = dependencyTag{name: "bpf", payload: true}
@@ -764,7 +763,6 @@
 	ctx.BottomUp("apex", apexMutator).Parallel()
 	ctx.BottomUp("apex_directly_in_any", apexDirectlyInAnyMutator).Parallel()
 	ctx.BottomUp("apex_flattened", apexFlattenedMutator).Parallel()
-	ctx.BottomUp("apex_uses", apexUsesMutator).Parallel()
 	ctx.BottomUp("mark_platform_availability", markPlatformAvailability).Parallel()
 }
 
@@ -1007,12 +1005,6 @@
 	}
 }
 
-func apexUsesMutator(mctx android.BottomUpMutatorContext) {
-	if ab, ok := mctx.Module().(*apexBundle); ok {
-		mctx.AddFarVariationDependencies(nil, usesTag, ab.properties.Uses...)
-	}
-}
-
 var (
 	useVendorAllowListKey = android.NewOnceKey("useVendorAllowList")
 )
@@ -1132,12 +1124,6 @@
 
 	HideFromMake bool `blueprint:"mutated"`
 
-	// Indicates this APEX provides C++ shared libaries to other APEXes. Default: false.
-	Provide_cpp_shared_libs *bool
-
-	// List of providing APEXes' names so that this APEX can depend on provided shared libraries.
-	Uses []string
-
 	// package format of this apex variant; could be non-flattened, flattened, or zip.
 	// imageApex, zipApex or flattened
 	ApexType apexPackaging `blueprint:"mutated"`
@@ -2181,30 +2167,6 @@
 	var provideNativeLibs []string
 	var requireNativeLibs []string
 
-	// Check if "uses" requirements are met with dependent apexBundles
-	var providedNativeSharedLibs []string
-	useVendor := proptools.Bool(a.properties.Use_vendor)
-	ctx.VisitDirectDepsBlueprint(func(m blueprint.Module) {
-		if ctx.OtherModuleDependencyTag(m) != usesTag {
-			return
-		}
-		otherName := ctx.OtherModuleName(m)
-		other, ok := m.(*apexBundle)
-		if !ok {
-			ctx.PropertyErrorf("uses", "%q is not a provider", otherName)
-			return
-		}
-		if proptools.Bool(other.properties.Use_vendor) != useVendor {
-			ctx.PropertyErrorf("use_vendor", "%q has different value of use_vendor", otherName)
-			return
-		}
-		if !proptools.Bool(other.properties.Provide_cpp_shared_libs) {
-			ctx.PropertyErrorf("uses", "%q does not provide native_shared_libs", otherName)
-			return
-		}
-		providedNativeSharedLibs = append(providedNativeSharedLibs, other.properties.Native_shared_libs...)
-	})
-
 	var filesInfo []apexFile
 	// TODO(jiyong) do this using WalkPayloadDeps
 	ctx.WalkDepsBlueprint(func(child, parent blueprint.Module) bool {
@@ -2352,11 +2314,6 @@
 				// tags used below are private (e.g. `cc.sharedDepTag`).
 				if cc.IsSharedDepTag(depTag) || cc.IsRuntimeDepTag(depTag) {
 					if cc, ok := child.(*cc.Module); ok {
-						if android.InList(cc.Name(), providedNativeSharedLibs) {
-							// If we're using a shared library which is provided from other APEX,
-							// don't include it in this APEX
-							return false
-						}
 						if cc.UseVndk() && proptools.Bool(a.properties.Use_vndk_as_stable) && cc.IsVndk() {
 							requireNativeLibs = append(requireNativeLibs, ":vndk")
 							return false
diff --git a/apex/apex_test.go b/apex/apex_test.go
index 532a7aa..33e5077 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -149,10 +149,8 @@
 		"system/sepolicy/apex/myapex.updatable-file_contexts": nil,
 		"system/sepolicy/apex/myapex2-file_contexts":          nil,
 		"system/sepolicy/apex/otherapex-file_contexts":        nil,
-		"system/sepolicy/apex/commonapex-file_contexts":       nil,
 		"system/sepolicy/apex/com.android.vndk-file_contexts": nil,
 		"mylib.cpp":                                  nil,
-		"mylib_common.cpp":                           nil,
 		"mytest.cpp":                                 nil,
 		"mytest1.cpp":                                nil,
 		"mytest2.cpp":                                nil,
@@ -4202,131 +4200,6 @@
 	ensureContains(t, androidMk, "LOCAL_REQUIRED_MODULES += myapex.flattened")
 }
 
-func TestApexUsesOtherApex(t *testing.T) {
-	ctx, _ := testApex(t, `
-		apex {
-			name: "myapex",
-			key: "myapex.key",
-			native_shared_libs: ["mylib"],
-			uses: ["commonapex"],
-		}
-
-		apex {
-			name: "commonapex",
-			key: "myapex.key",
-			native_shared_libs: ["libcommon"],
-			provide_cpp_shared_libs: true,
-		}
-
-		apex_key {
-			name: "myapex.key",
-			public_key: "testkey.avbpubkey",
-			private_key: "testkey.pem",
-		}
-
-		cc_library {
-			name: "mylib",
-			srcs: ["mylib.cpp"],
-			shared_libs: ["libcommon"],
-			system_shared_libs: [],
-			stl: "none",
-			apex_available: [ "myapex" ],
-		}
-
-		cc_library {
-			name: "libcommon",
-			srcs: ["mylib_common.cpp"],
-			system_shared_libs: [],
-			stl: "none",
-			// TODO: remove //apex_available:platform
-			apex_available: [
-				"//apex_available:platform",
-				"commonapex",
-				"myapex",
-			],
-		}
-	`)
-
-	module1 := ctx.ModuleForTests("myapex", "android_common_myapex_image")
-	apexRule1 := module1.Rule("apexRule")
-	copyCmds1 := apexRule1.Args["copy_commands"]
-
-	module2 := ctx.ModuleForTests("commonapex", "android_common_commonapex_image")
-	apexRule2 := module2.Rule("apexRule")
-	copyCmds2 := apexRule2.Args["copy_commands"]
-
-	ensureListContains(t, ctx.ModuleVariantsForTests("mylib"), "android_arm64_armv8-a_shared_apex10000")
-	ensureListContains(t, ctx.ModuleVariantsForTests("libcommon"), "android_arm64_armv8-a_shared_apex10000")
-	ensureContains(t, copyCmds1, "image.apex/lib64/mylib.so")
-	ensureContains(t, copyCmds2, "image.apex/lib64/libcommon.so")
-	ensureNotContains(t, copyCmds1, "image.apex/lib64/libcommon.so")
-}
-
-func TestApexUsesFailsIfNotProvided(t *testing.T) {
-	testApexError(t, `uses: "commonapex" does not provide native_shared_libs`, `
-		apex {
-			name: "myapex",
-			key: "myapex.key",
-			uses: ["commonapex"],
-		}
-
-		apex {
-			name: "commonapex",
-			key: "myapex.key",
-		}
-
-		apex_key {
-			name: "myapex.key",
-			public_key: "testkey.avbpubkey",
-			private_key: "testkey.pem",
-		}
-	`)
-	testApexError(t, `uses: "commonapex" is not a provider`, `
-		apex {
-			name: "myapex",
-			key: "myapex.key",
-			uses: ["commonapex"],
-		}
-
-		cc_library {
-			name: "commonapex",
-			system_shared_libs: [],
-			stl: "none",
-		}
-
-		apex_key {
-			name: "myapex.key",
-			public_key: "testkey.avbpubkey",
-			private_key: "testkey.pem",
-		}
-	`)
-}
-
-func TestApexUsesFailsIfUseVenderMismatch(t *testing.T) {
-	testApexError(t, `use_vendor: "commonapex" has different value of use_vendor`, `
-		apex {
-			name: "myapex",
-			key: "myapex.key",
-			use_vendor: true,
-			uses: ["commonapex"],
-		}
-
-		apex {
-			name: "commonapex",
-			key: "myapex.key",
-			provide_cpp_shared_libs: true,
-		}
-
-		apex_key {
-			name: "myapex.key",
-			public_key: "testkey.avbpubkey",
-			private_key: "testkey.pem",
-		}
-	`, func(fs map[string][]byte, config android.Config) {
-		setUseVendorAllowListForTest(config, []string{"myapex"})
-	})
-}
-
 func TestErrorsIfDepsAreNotEnabled(t *testing.T) {
 	testApexError(t, `module "myapex" .* depends on disabled module "libfoo"`, `
 		apex {
@@ -5574,7 +5447,7 @@
 		}
 		`, withManifestPackageNameOverrides([]string{"AppFoo:com.android.foo"}))
 
-	bundleConfigRule := ctx.ModuleForTests("myapex", "android_common_myapex_image").Description("Bundle Config")
+	bundleConfigRule := ctx.ModuleForTests("myapex", "android_common_myapex_image").Output("bundle_config.json")
 	content := bundleConfigRule.Args["content"]
 
 	ensureContains(t, content, `"compression":{"uncompressed_glob":["apex_payload.img","apex_manifest.*"]}`)
@@ -5600,7 +5473,7 @@
 			set: "AppSet.apks",
 		}`)
 	mod := ctx.ModuleForTests("myapex", "android_common_myapex_image")
-	bundleConfigRule := mod.Description("Bundle Config")
+	bundleConfigRule := mod.Output("bundle_config.json")
 	content := bundleConfigRule.Args["content"]
 	ensureContains(t, content, `"compression":{"uncompressed_glob":["apex_payload.img","apex_manifest.*"]}`)
 	s := mod.Rule("apexRule").Args["copy_commands"]
diff --git a/apex/builder.go b/apex/builder.go
index ad673d6..acfb8c5 100644
--- a/apex/builder.go
+++ b/apex/builder.go
@@ -373,14 +373,7 @@
 		panic(fmt.Errorf("error while marshalling to %q: %#v", output, err))
 	}
 
-	ctx.Build(pctx, android.BuildParams{
-		Rule:        android.WriteFile,
-		Output:      output,
-		Description: "Bundle Config " + output.String(),
-		Args: map[string]string{
-			"content": string(j),
-		},
-	})
+	android.WriteFileRule(ctx, output, string(j))
 
 	return output.OutputPath
 }
diff --git a/apex/key.go b/apex/key.go
index d2d5786..43764da 100644
--- a/apex/key.go
+++ b/apex/key.go
@@ -116,7 +116,7 @@
 		partition             string
 	}
 	toString := func(e apexKeyEntry) string {
-		format := "name=%q public_key=%q private_key=%q container_certificate=%q container_private_key=%q partition=%q\\n"
+		format := "name=%q public_key=%q private_key=%q container_certificate=%q container_private_key=%q partition=%q\n"
 		if e.presigned {
 			return fmt.Sprintf(format, e.name, "PRESIGNED", "PRESIGNED", "PRESIGNED", "PRESIGNED", e.partition)
 		} else {
@@ -173,17 +173,9 @@
 
 	var filecontent strings.Builder
 	for _, name := range moduleNames {
-		fmt.Fprintf(&filecontent, "%s", toString(apexKeyMap[name]))
+		filecontent.WriteString(toString(apexKeyMap[name]))
 	}
-
-	ctx.Build(pctx, android.BuildParams{
-		Rule:        android.WriteFile,
-		Description: "apexkeys.txt",
-		Output:      s.output,
-		Args: map[string]string{
-			"content": filecontent.String(),
-		},
-	})
+	android.WriteFileRule(ctx, s.output, filecontent.String())
 }
 
 func apexKeysTextFactory() android.Singleton {
diff --git a/cc/cc_test.go b/cc/cc_test.go
index b803cba..f616cf3 100644
--- a/cc/cc_test.go
+++ b/cc/cc_test.go
@@ -296,8 +296,8 @@
 
 func checkWriteFileOutput(t *testing.T, params android.TestingBuildParams, expected []string) {
 	t.Helper()
-	assertString(t, params.Rule.String(), android.WriteFile.String())
-	actual := strings.FieldsFunc(strings.ReplaceAll(params.Args["content"], "\\n", "\n"), func(r rune) bool { return r == '\n' })
+	content := android.ContentFromFileRuleForTests(t, params)
+	actual := strings.FieldsFunc(content, func(r rune) bool { return r == '\n' })
 	assertArrayString(t, actual, expected)
 }
 
diff --git a/cc/fuzz.go b/cc/fuzz.go
index fe3c12b..dddfe94 100644
--- a/cc/fuzz.go
+++ b/cc/fuzz.go
@@ -278,14 +278,7 @@
 
 	if fuzz.Properties.Fuzz_config != nil {
 		configPath := android.PathForModuleOut(ctx, "config").Join(ctx, "config.json")
-		ctx.Build(pctx, android.BuildParams{
-			Rule:        android.WriteFile,
-			Description: "fuzzer infrastructure configuration",
-			Output:      configPath,
-			Args: map[string]string{
-				"content": fuzz.Properties.Fuzz_config.String(),
-			},
-		})
+		android.WriteFileRule(ctx, configPath, fuzz.Properties.Fuzz_config.String())
 		fuzz.config = configPath
 	}
 
diff --git a/cc/snapshot_utils.go b/cc/snapshot_utils.go
index 238508d..05c06ac 100644
--- a/cc/snapshot_utils.go
+++ b/cc/snapshot_utils.go
@@ -93,13 +93,6 @@
 
 func writeStringToFile(ctx android.SingletonContext, content, out string) android.OutputPath {
 	outPath := android.PathForOutput(ctx, out)
-	ctx.Build(pctx, android.BuildParams{
-		Rule:        android.WriteFile,
-		Output:      outPath,
-		Description: "WriteFile " + out,
-		Args: map[string]string{
-			"content": content,
-		},
-	})
+	android.WriteFileRule(ctx, outPath, content)
 	return outPath
 }
diff --git a/cc/vndk.go b/cc/vndk.go
index 2cac03c..4a005f3 100644
--- a/cc/vndk.go
+++ b/cc/vndk.go
@@ -487,14 +487,7 @@
 	}
 
 	txt.outputFile = android.PathForModuleOut(ctx, filename).OutputPath
-	ctx.Build(pctx, android.BuildParams{
-		Rule:        android.WriteFile,
-		Output:      txt.outputFile,
-		Description: "Writing " + txt.outputFile.String(),
-		Args: map[string]string{
-			"content": strings.Join(list, "\\n"),
-		},
-	})
+	android.WriteFileRule(ctx, txt.outputFile, strings.Join(list, "\n"))
 
 	installPath := android.PathForModuleInstall(ctx, "etc")
 	ctx.InstallFile(installPath, filename, txt.outputFile)
@@ -825,14 +818,7 @@
 	merged = append(merged, addPrefix(filterOutLibClangRt(vndkcore), "VNDK-core: ")...)
 	merged = append(merged, addPrefix(vndkprivate, "VNDK-private: ")...)
 	c.vndkLibrariesFile = android.PathForOutput(ctx, "vndk", "vndk.libraries.txt")
-	ctx.Build(pctx, android.BuildParams{
-		Rule:        android.WriteFile,
-		Output:      c.vndkLibrariesFile,
-		Description: "Writing " + c.vndkLibrariesFile.String(),
-		Args: map[string]string{
-			"content": strings.Join(merged, "\\n"),
-		},
-	})
+	android.WriteFileRule(ctx, c.vndkLibrariesFile, strings.Join(merged, "\n"))
 }
 
 func (c *vndkSnapshotSingleton) MakeVars(ctx android.MakeVarsContext) {
diff --git a/dexpreopt/class_loader_context.go b/dexpreopt/class_loader_context.go
index 6d77812..77d6ee9 100644
--- a/dexpreopt/class_loader_context.go
+++ b/dexpreopt/class_loader_context.go
@@ -16,7 +16,7 @@
 
 import (
 	"fmt"
-	"path/filepath"
+	"strconv"
 	"strings"
 
 	"android/soong/android"
@@ -49,39 +49,39 @@
 
 const UnknownInstallLibraryPath = "error"
 
-const AnySdkVersion int = 9999 // should go last in class loader context
+// AnySdkVersion means that the class loader context is needed regardless of the targetSdkVersion
+// of the app. The numeric value affects the key order in the map and, as a result, the order of
+// arguments passed to construct_context.py (high value means that the unconditional context goes
+// last). We use the converntional "current" SDK level (10000), but any big number would do as well.
+const AnySdkVersion int = android.FutureApiLevelInt
 
-// LibraryPath contains paths to the library DEX jar on host and on device.
-type LibraryPath struct {
-	Host   android.Path
+// ClassLoaderContext is a tree of libraries used by the dexpreopted module with their dependencies.
+// The context is used by dex2oat to compile the module and recorded in the AOT-compiled files, so
+// that it can be checked agains the run-time class loader context on device. If there is a mismatch
+// at runtime, AOT-compiled code is rejected.
+type ClassLoaderContext struct {
+	// The name of the library (same as the name of the module that contains it).
+	Name string
+
+	// On-host build path to the library dex file (used in dex2oat argument --class-loader-context).
+	Host android.Path
+
+	// On-device install path (used in dex2oat argument --stored-class-loader-context).
 	Device string
+
+	// Nested class loader subcontexts for dependencies.
+	Subcontexts []*ClassLoaderContext
 }
 
-// LibraryPaths is a map from library name to on-host and on-device paths to its DEX jar.
-type LibraryPaths map[string]*LibraryPath
+// ClassLoaderContextMap is a map from SDK version to a class loader context.
+// There is a special entry with key AnySdkVersion that stores unconditional class loader context.
+// Other entries store conditional contexts that should be added for some apps that have
+// targetSdkVersion in the manifest lower than the key SDK version.
+type ClassLoaderContextMap map[int][]*ClassLoaderContext
 
-type classLoaderContext struct {
-	// Library names
-	Names []string
-
-	// The class loader context using paths in the build.
-	Host android.Paths
-
-	// The class loader context using paths as they will be on the device.
-	Target []string
-}
-
-// A map of class loader contexts for each SDK version.
-// A map entry for "any" version contains libraries that are unconditionally added to class loader
-// context. Map entries for existing versions contains libraries that were in the default classpath
-// until that API version, and should be added to class loader context if and only if the
-// targetSdkVersion in the manifest or APK is less than that API version.
-type classLoaderContextMap map[int]*classLoaderContext
-
-// Add a new library path to the map, unless a path for this library already exists.
-// If necessary, check that the build and install paths exist.
-func (libPaths LibraryPaths) addLibraryPath(ctx android.ModuleInstallPathContext, lib string,
-	hostPath, installPath android.Path, strict bool) error {
+// Add class loader context for the given library to the map entry for the given SDK version.
+func (clcMap ClassLoaderContextMap) addContext(ctx android.ModuleInstallPathContext, sdkVer int, lib string,
+	hostPath, installPath android.Path, strict bool, nestedClcMap ClassLoaderContextMap) error {
 
 	// If missing dependencies are allowed, the build shouldn't fail when a <uses-library> is
 	// not found. However, this is likely to result is disabling dexpreopt, as it won't be
@@ -89,263 +89,277 @@
 	strict = strict && !ctx.Config().AllowMissingDependencies()
 
 	if hostPath == nil && strict {
-		return fmt.Errorf("unknown build path to <uses-library> '%s'", lib)
+		return fmt.Errorf("unknown build path to <uses-library> \"%s\"", lib)
 	}
 
+	devicePath := UnknownInstallLibraryPath
 	if installPath == nil {
 		if android.InList(lib, CompatUsesLibs) || android.InList(lib, OptionalCompatUsesLibs) {
 			// Assume that compatibility libraries are installed in /system/framework.
 			installPath = android.PathForModuleInstall(ctx, "framework", lib+".jar")
 		} else if strict {
-			return fmt.Errorf("unknown install path to <uses-library> '%s'", lib)
-		}
-	}
-
-	// Add a library only if the build and install path to it is known.
-	if _, present := libPaths[lib]; !present {
-		var devicePath string
-		if installPath != nil {
-			devicePath = android.InstallPathToOnDevicePath(ctx, installPath.(android.InstallPath))
+			return fmt.Errorf("unknown install path to <uses-library> \"%s\"", lib)
 		} else {
 			// For some stub libraries the only known thing is the name of their implementation
 			// library, but the library itself is unavailable (missing or part of a prebuilt). In
 			// such cases we still need to add the library to <uses-library> tags in the manifest,
-			// but we cannot use if for dexpreopt.
-			devicePath = UnknownInstallLibraryPath
+			// but we cannot use it for dexpreopt.
 		}
-		libPaths[lib] = &LibraryPath{hostPath, devicePath}
 	}
+	if installPath != nil {
+		devicePath = android.InstallPathToOnDevicePath(ctx, installPath.(android.InstallPath))
+	}
+
+	// Nested class loader context shouldn't have conditional part (it is allowed only at the top level).
+	for ver, _ := range nestedClcMap {
+		if ver != AnySdkVersion {
+			clcStr, _ := ComputeClassLoaderContext(nestedClcMap)
+			return fmt.Errorf("nested class loader context shouldn't have conditional part: %s", clcStr)
+		}
+	}
+	subcontexts := nestedClcMap[AnySdkVersion]
+
+	// If the library with this name is already present as one of the unconditional top-level
+	// components, do not re-add it.
+	for _, clc := range clcMap[sdkVer] {
+		if clc.Name == lib {
+			return nil
+		}
+	}
+
+	clcMap[sdkVer] = append(clcMap[sdkVer], &ClassLoaderContext{
+		Name:        lib,
+		Host:        hostPath,
+		Device:      devicePath,
+		Subcontexts: subcontexts,
+	})
 	return nil
 }
 
-// Wrapper around addLibraryPath that does error reporting.
-func (libPaths LibraryPaths) addLibraryPathOrReportError(ctx android.ModuleInstallPathContext, lib string,
-	hostPath, installPath android.Path, strict bool) {
+// Wrapper around addContext that reports errors.
+func (clcMap ClassLoaderContextMap) addContextOrReportError(ctx android.ModuleInstallPathContext, sdkVer int, lib string,
+	hostPath, installPath android.Path, strict bool, nestedClcMap ClassLoaderContextMap) {
 
-	err := libPaths.addLibraryPath(ctx, lib, hostPath, installPath, strict)
+	err := clcMap.addContext(ctx, sdkVer, lib, hostPath, installPath, strict, nestedClcMap)
 	if err != nil {
+		ctx.ModuleErrorf(err.Error())
 		android.ReportPathErrorf(ctx, err.Error())
 	}
 }
 
-// Add a new library path to the map. Enforce checks that the library paths exist.
-func (libPaths LibraryPaths) AddLibraryPath(ctx android.ModuleInstallPathContext, lib string, hostPath, installPath android.Path) {
-	libPaths.addLibraryPathOrReportError(ctx, lib, hostPath, installPath, true)
+// Add class loader context. Fail on unknown build/install paths.
+func (clcMap ClassLoaderContextMap) AddContext(ctx android.ModuleInstallPathContext, lib string,
+	hostPath, installPath android.Path) {
+
+	clcMap.addContextOrReportError(ctx, AnySdkVersion, lib, hostPath, installPath, true, nil)
 }
 
-// Add a new library path to the map, if the library exists (name is not nil).
-// Don't enforce checks that the library paths exist. Some libraries may be missing from the build,
-// but their names still need to be added to <uses-library> tags in the manifest.
-func (libPaths LibraryPaths) MaybeAddLibraryPath(ctx android.ModuleInstallPathContext, lib *string, hostPath, installPath android.Path) {
+// Add class loader context if the library exists. Don't fail on unknown build/install paths.
+func (clcMap ClassLoaderContextMap) MaybeAddContext(ctx android.ModuleInstallPathContext, lib *string,
+	hostPath, installPath android.Path) {
+
 	if lib != nil {
-		libPaths.addLibraryPathOrReportError(ctx, *lib, hostPath, installPath, false)
+		clcMap.addContextOrReportError(ctx, AnySdkVersion, *lib, hostPath, installPath, false, nil)
 	}
 }
 
-// Add library paths from the second map to the first map (do not override existing entries).
-func (libPaths LibraryPaths) AddLibraryPaths(otherPaths LibraryPaths) {
-	for lib, path := range otherPaths {
-		if _, present := libPaths[lib]; !present {
-			libPaths[lib] = path
+// Add class loader context for the given SDK version. Fail on unknown build/install paths.
+func (clcMap ClassLoaderContextMap) AddContextForSdk(ctx android.ModuleInstallPathContext, sdkVer int,
+	lib string, hostPath, installPath android.Path, nestedClcMap ClassLoaderContextMap) {
+
+	clcMap.addContextOrReportError(ctx, sdkVer, lib, hostPath, installPath, true, nestedClcMap)
+}
+
+// Merge the other class loader context map into this one, do not override existing entries.
+// The implicitRootLib parameter is the name of the library for which the other class loader
+// context map was constructed. If the implicitRootLib is itself a <uses-library>, it should be
+// already present in the class loader context (with the other context as its subcontext) -- in
+// that case do not re-add the other context. Otherwise add the other context at the top-level.
+func (clcMap ClassLoaderContextMap) AddContextMap(otherClcMap ClassLoaderContextMap, implicitRootLib string) {
+	if otherClcMap == nil {
+		return
+	}
+
+	// If the implicit root of the merged map is already present as one of top-level subtrees, do
+	// not merge it second time.
+	for _, clc := range clcMap[AnySdkVersion] {
+		if clc.Name == implicitRootLib {
+			return
 		}
 	}
-}
 
-func (m classLoaderContextMap) getValue(sdkVer int) *classLoaderContext {
-	if _, ok := m[sdkVer]; !ok {
-		m[sdkVer] = &classLoaderContext{}
-	}
-	return m[sdkVer]
-}
-
-func (clc *classLoaderContext) addLib(lib string, hostPath android.Path, targetPath string) {
-	clc.Names = append(clc.Names, lib)
-	clc.Host = append(clc.Host, hostPath)
-	clc.Target = append(clc.Target, targetPath)
-}
-
-func (m classLoaderContextMap) addLibs(ctx android.PathContext, sdkVer int, module *ModuleConfig,
-	libs ...string) (bool, error) {
-
-	clc := m.getValue(sdkVer)
-	for _, lib := range libs {
-		if p, ok := module.LibraryPaths[lib]; ok && p.Host != nil && p.Device != UnknownInstallLibraryPath {
-			clc.addLib(lib, p.Host, p.Device)
-		} else {
-			if sdkVer == AnySdkVersion {
-				// Fail the build if dexpreopt doesn't know paths to one of the <uses-library>
-				// dependencies. In the future we may need to relax this and just disable dexpreopt.
-				return false, fmt.Errorf("dexpreopt cannot find path for <uses-library> '%s'", lib)
-			} else {
-				// No error for compatibility libraries, as Soong doesn't know if they are needed
-				// (this depends on the targetSdkVersion in the manifest).
-				return false, nil
+	for sdkVer, otherClcs := range otherClcMap {
+		for _, otherClc := range otherClcs {
+			alreadyHave := false
+			for _, clc := range clcMap[sdkVer] {
+				if clc.Name == otherClc.Name {
+					alreadyHave = true
+					break
+				}
+			}
+			if !alreadyHave {
+				clcMap[sdkVer] = append(clcMap[sdkVer], otherClc)
 			}
 		}
 	}
-	return true, nil
 }
 
-func (m classLoaderContextMap) addSystemServerLibs(sdkVer int, ctx android.PathContext, module *ModuleConfig, libs ...string) {
-	clc := m.getValue(sdkVer)
-	for _, lib := range libs {
-		clc.addLib(lib, SystemServerDexJarHostPath(ctx, lib), filepath.Join("/system/framework", lib+".jar"))
+// List of libraries in the unconditional class loader context, excluding dependencies of shared libraries.
+func (clcMap ClassLoaderContextMap) UsesLibs() (ulibs []string) {
+	if clcMap != nil {
+		// compatibility libraries (those in conditional context) are not added to <uses-library> tags
+		ulibs = usesLibsRec(clcMap[AnySdkVersion])
+		ulibs = android.FirstUniqueStrings(ulibs)
 	}
+	return ulibs
 }
 
-func (m classLoaderContextMap) usesLibs() []string {
-	if clc, ok := m[AnySdkVersion]; ok {
-		return clc.Names
+func usesLibsRec(clcs []*ClassLoaderContext) (ulibs []string) {
+	for _, clc := range clcs {
+		ulibs = append(ulibs, clc.Name)
+		ulibs = append(ulibs, usesLibsRec(clc.Subcontexts)...)
 	}
-	return nil
-}
-
-// genClassLoaderContext generates host and target class loader context to be passed to the dex2oat
-// command for the dexpreopted module. There are three possible cases:
-//
-// 1. System server jars. They have a special class loader context that includes other system
-//    server jars.
-//
-// 2. Library jars or APKs which have precise list of their <uses-library> libs. Their class loader
-//    context includes build and on-device paths to these libs. In some cases it may happen that
-//    the path to a <uses-library> is unknown (e.g. the dexpreopted module may depend on stubs
-//    library, whose implementation library is missing from the build altogether). In such case
-//    dexpreopting with the <uses-library> is impossible, and dexpreopting without it is pointless,
-//    as the runtime classpath won't match and the dexpreopted code will be discarded. Therefore in
-//    such cases the function returns nil, which disables dexpreopt.
-//
-// 3. All other library jars or APKs for which the exact <uses-library> list is unknown. They use
-//    the unsafe &-classpath workaround that means empty class loader context and absence of runtime
-//    check that the class loader context provided by the PackageManager agrees with the stored
-//    class loader context recorded in the .odex file.
-//
-func genClassLoaderContext(ctx android.PathContext, global *GlobalConfig, module *ModuleConfig) (*classLoaderContextMap, error) {
-	classLoaderContexts := make(classLoaderContextMap)
-	systemServerJars := NonUpdatableSystemServerJars(ctx, global)
-
-	if jarIndex := android.IndexList(module.Name, systemServerJars); jarIndex >= 0 {
-		// System server jars should be dexpreopted together: class loader context of each jar
-		// should include all preceding jars on the system server classpath.
-		classLoaderContexts.addSystemServerLibs(AnySdkVersion, ctx, module, systemServerJars[:jarIndex]...)
-
-	} else if module.EnforceUsesLibraries {
-		// Unconditional class loader context.
-		usesLibs := append(copyOf(module.UsesLibraries), module.OptionalUsesLibraries...)
-		if ok, err := classLoaderContexts.addLibs(ctx, AnySdkVersion, module, usesLibs...); !ok {
-			return nil, err
-		}
-
-		// Conditional class loader context for API version < 28.
-		const httpLegacy = "org.apache.http.legacy"
-		if ok, err := classLoaderContexts.addLibs(ctx, 28, module, httpLegacy); !ok {
-			return nil, err
-		}
-
-		// Conditional class loader context for API version < 29.
-		usesLibs29 := []string{
-			"android.hidl.base-V1.0-java",
-			"android.hidl.manager-V1.0-java",
-		}
-		if ok, err := classLoaderContexts.addLibs(ctx, 29, module, usesLibs29...); !ok {
-			return nil, err
-		}
-
-		// Conditional class loader context for API version < 30.
-		if ok, err := classLoaderContexts.addLibs(ctx, 30, module, OptionalCompatUsesLibs30...); !ok {
-			return nil, err
-		}
-
-	} else {
-		// Pass special class loader context to skip the classpath and collision check.
-		// This will get removed once LOCAL_USES_LIBRARIES is enforced.
-		// Right now LOCAL_USES_LIBRARIES is opt in, for the case where it's not specified we still default
-		// to the &.
-	}
-
-	fixConditionalClassLoaderContext(classLoaderContexts)
-
-	return &classLoaderContexts, nil
+	return ulibs
 }
 
 // Now that the full unconditional context is known, reconstruct conditional context.
 // Apply filters for individual libraries, mirroring what the PackageManager does when it
 // constructs class loader context on device.
 //
-// TODO(b/132357300):
-//   - remove android.hidl.manager and android.hidl.base unless the app is a system app.
+// TODO(b/132357300): remove "android.hidl.manager" and "android.hidl.base" for non-system apps.
 //
-func fixConditionalClassLoaderContext(clcMap classLoaderContextMap) {
-	usesLibs := clcMap.usesLibs()
+func fixClassLoaderContext(clcMap ClassLoaderContextMap) {
+	usesLibs := clcMap.UsesLibs()
 
-	for sdkVer, clc := range clcMap {
+	for sdkVer, clcs := range clcMap {
 		if sdkVer == AnySdkVersion {
 			continue
 		}
-		clcMap[sdkVer] = &classLoaderContext{}
-		for i, lib := range clc.Names {
-			if android.InList(lib, usesLibs) {
+		fixedClcs := []*ClassLoaderContext{}
+		for _, clc := range clcs {
+			if android.InList(clc.Name, usesLibs) {
 				// skip compatibility libraries that are already included in unconditional context
-			} else if lib == AndroidTestMock && !android.InList("android.test.runner", usesLibs) {
+			} else if clc.Name == AndroidTestMock && !android.InList("android.test.runner", usesLibs) {
 				// android.test.mock is only needed as a compatibility library (in conditional class
 				// loader context) if android.test.runner is used, otherwise skip it
 			} else {
-				clcMap[sdkVer].addLib(lib, clc.Host[i], clc.Target[i])
+				fixedClcs = append(fixedClcs, clc)
 			}
+			clcMap[sdkVer] = fixedClcs
 		}
 	}
 }
 
-// Return the class loader context as a string and a slice of build paths for all dependencies.
-func computeClassLoaderContext(ctx android.PathContext, clcMap classLoaderContextMap) (clcStr string, paths android.Paths) {
-	for _, ver := range android.SortedIntKeys(clcMap) {
-		clc := clcMap.getValue(ver)
-
-		clcLen := len(clc.Names)
-		if clcLen != len(clc.Host) || clcLen != len(clc.Target) {
-			android.ReportPathErrorf(ctx, "ill-formed class loader context")
+// Return true if all build/install library paths are valid (including recursive subcontexts),
+// otherwise return false. A build path is valid if it's not nil. An install path is valid if it's
+// not equal to a special "error" value.
+func validateClassLoaderContext(clcMap ClassLoaderContextMap) (bool, error) {
+	for sdkVer, clcs := range clcMap {
+		if valid, err := validateClassLoaderContextRec(sdkVer, clcs); !valid || err != nil {
+			return valid, err
 		}
+	}
+	return true, nil
+}
 
-		var hostClc, targetClc []string
-		var hostPaths android.Paths
-
-		for i := 0; i < clcLen; i++ {
-			hostStr := "PCL[" + clc.Host[i].String() + "]"
-			targetStr := "PCL[" + clc.Target[i] + "]"
-
-			hostClc = append(hostClc, hostStr)
-			targetClc = append(targetClc, targetStr)
-			hostPaths = append(hostPaths, clc.Host[i])
+func validateClassLoaderContextRec(sdkVer int, clcs []*ClassLoaderContext) (bool, error) {
+	for _, clc := range clcs {
+		if clc.Host == nil || clc.Device == UnknownInstallLibraryPath {
+			if sdkVer == AnySdkVersion {
+				// Return error if dexpreopt doesn't know paths to one of the <uses-library>
+				// dependencies. In the future we may need to relax this and just disable dexpreopt.
+				return false, fmt.Errorf("invalid path for <uses-library> \"%s\"", clc.Name)
+			} else {
+				// No error for compatibility libraries, as Soong doesn't know if they are needed
+				// (this depends on the targetSdkVersion in the manifest), but the CLC is invalid.
+				return false, nil
+			}
 		}
+		if valid, err := validateClassLoaderContextRec(sdkVer, clc.Subcontexts); !valid || err != nil {
+			return valid, err
+		}
+	}
+	return true, nil
+}
 
+// Return the class loader context as a string, and a slice of build paths for all dependencies.
+// Perform a depth-first preorder traversal of the class loader context tree for each SDK version.
+// Return the resulting string and a slice of on-host build paths to all library dependencies.
+func ComputeClassLoaderContext(clcMap ClassLoaderContextMap) (clcStr string, paths android.Paths) {
+	for _, sdkVer := range android.SortedIntKeys(clcMap) { // determinisitc traversal order
+		sdkVerStr := fmt.Sprintf("%d", sdkVer)
+		if sdkVer == AnySdkVersion {
+			sdkVerStr = "any" // a special keyword that means any SDK version
+		}
+		hostClc, targetClc, hostPaths := computeClassLoaderContextRec(clcMap[sdkVer])
 		if hostPaths != nil {
-			sdkVerStr := fmt.Sprintf("%d", ver)
-			if ver == AnySdkVersion {
-				sdkVerStr = "any" // a special keyword that means any SDK version
-			}
-			clcStr += fmt.Sprintf(" --host-context-for-sdk %s %s", sdkVerStr, strings.Join(hostClc, "#"))
-			clcStr += fmt.Sprintf(" --target-context-for-sdk %s %s", sdkVerStr, strings.Join(targetClc, "#"))
-			paths = append(paths, hostPaths...)
+			clcStr += fmt.Sprintf(" --host-context-for-sdk %s %s", sdkVerStr, hostClc)
+			clcStr += fmt.Sprintf(" --target-context-for-sdk %s %s", sdkVerStr, targetClc)
 		}
+		paths = append(paths, hostPaths...)
 	}
-
-	return clcStr, paths
+	return clcStr, android.FirstUniquePaths(paths)
 }
 
+func computeClassLoaderContextRec(clcs []*ClassLoaderContext) (string, string, android.Paths) {
+	var paths android.Paths
+	var clcsHost, clcsTarget []string
+
+	for _, clc := range clcs {
+		subClcHost, subClcTarget, subPaths := computeClassLoaderContextRec(clc.Subcontexts)
+		if subPaths != nil {
+			subClcHost = "{" + subClcHost + "}"
+			subClcTarget = "{" + subClcTarget + "}"
+		}
+
+		clcsHost = append(clcsHost, "PCL["+clc.Host.String()+"]"+subClcHost)
+		clcsTarget = append(clcsTarget, "PCL["+clc.Device+"]"+subClcTarget)
+
+		paths = append(paths, clc.Host)
+		paths = append(paths, subPaths...)
+	}
+
+	clcHost := strings.Join(clcsHost, "#")
+	clcTarget := strings.Join(clcsTarget, "#")
+
+	return clcHost, clcTarget, paths
+}
+
+// Paths to a <uses-library> on host and on device.
 type jsonLibraryPath struct {
 	Host   string
 	Device string
 }
 
-type jsonLibraryPaths map[string]jsonLibraryPath
+// Class loader contexts that come from Make (via JSON dexpreopt.config) files have simpler
+// structure than Soong class loader contexts: they are flat maps from a <uses-library> name to its
+// on-host and on-device paths. There are no nested subcontexts. It is a limitation of the current
+// Make implementation.
+type jsonClassLoaderContext map[string]jsonLibraryPath
 
-// convert JSON map of library paths to LibraryPaths
-func constructLibraryPaths(ctx android.PathContext, paths jsonLibraryPaths) LibraryPaths {
-	m := LibraryPaths{}
-	for lib, path := range paths {
-		m[lib] = &LibraryPath{
-			constructPath(ctx, path.Host),
-			path.Device,
+// A map from SDK version (represented with a JSON string) to JSON class loader context.
+type jsonClassLoaderContextMap map[string]jsonClassLoaderContext
+
+// Convert JSON class loader context map to ClassLoaderContextMap.
+func fromJsonClassLoaderContext(ctx android.PathContext, jClcMap jsonClassLoaderContextMap) ClassLoaderContextMap {
+	clcMap := make(ClassLoaderContextMap)
+	for sdkVerStr, clc := range jClcMap {
+		sdkVer, ok := strconv.Atoi(sdkVerStr)
+		if ok != nil {
+			if sdkVerStr == "any" {
+				sdkVer = AnySdkVersion
+			} else {
+				android.ReportPathErrorf(ctx, "failed to parse SDK version in dexpreopt.config: '%s'", sdkVerStr)
+			}
+		}
+		for lib, path := range clc {
+			clcMap[sdkVer] = append(clcMap[sdkVer], &ClassLoaderContext{
+				Name:        lib,
+				Host:        constructPath(ctx, path.Host),
+				Device:      path.Device,
+				Subcontexts: nil,
+			})
 		}
 	}
-	return m
+	return clcMap
 }
diff --git a/dexpreopt/class_loader_context_test.go b/dexpreopt/class_loader_context_test.go
index 51c1a0a..e0a75bf 100644
--- a/dexpreopt/class_loader_context_test.go
+++ b/dexpreopt/class_loader_context_test.go
@@ -37,91 +37,79 @@
 	//     ├── b
 	//     ├── c
 	//     ├── d
-	//     ├── a2
-	//     ├── b2
-	//     ├── c2
-	//     ├── a1
-	//     ├── b1
+	//     │   ├── a2
+	//     │   ├── b2
+	//     │   └── c2
+	//     │       ├── a1
+	//     │       └── b1
 	//     ├── f
 	//     ├── a3
 	//     └── b3
 	//
 	ctx := testContext()
 
-	lp := make(LibraryPaths)
+	m := make(ClassLoaderContextMap)
 
-	lp.AddLibraryPath(ctx, "a", buildPath(ctx, "a"), installPath(ctx, "a"))
-	lp.AddLibraryPath(ctx, "b", buildPath(ctx, "b"), installPath(ctx, "b"))
+	m.AddContext(ctx, "a", buildPath(ctx, "a"), installPath(ctx, "a"))
+	m.AddContext(ctx, "b", buildPath(ctx, "b"), installPath(ctx, "b"))
 
 	// "Maybe" variant in the good case: add as usual.
 	c := "c"
-	lp.MaybeAddLibraryPath(ctx, &c, buildPath(ctx, "c"), installPath(ctx, "c"))
+	m.MaybeAddContext(ctx, &c, buildPath(ctx, "c"), installPath(ctx, "c"))
 
 	// "Maybe" variant in the bad case: don't add library with unknown name, keep going.
-	lp.MaybeAddLibraryPath(ctx, nil, nil, nil)
+	m.MaybeAddContext(ctx, nil, nil, nil)
 
 	// Add some libraries with nested subcontexts.
 
-	lp1 := make(LibraryPaths)
-	lp1.AddLibraryPath(ctx, "a1", buildPath(ctx, "a1"), installPath(ctx, "a1"))
-	lp1.AddLibraryPath(ctx, "b1", buildPath(ctx, "b1"), installPath(ctx, "b1"))
+	m1 := make(ClassLoaderContextMap)
+	m1.AddContext(ctx, "a1", buildPath(ctx, "a1"), installPath(ctx, "a1"))
+	m1.AddContext(ctx, "b1", buildPath(ctx, "b1"), installPath(ctx, "b1"))
 
-	lp2 := make(LibraryPaths)
-	lp2.AddLibraryPath(ctx, "a2", buildPath(ctx, "a2"), installPath(ctx, "a2"))
-	lp2.AddLibraryPath(ctx, "b2", buildPath(ctx, "b2"), installPath(ctx, "b2"))
-	lp2.AddLibraryPath(ctx, "c2", buildPath(ctx, "c2"), installPath(ctx, "c2"))
-	lp2.AddLibraryPaths(lp1)
+	m2 := make(ClassLoaderContextMap)
+	m2.AddContext(ctx, "a2", buildPath(ctx, "a2"), installPath(ctx, "a2"))
+	m2.AddContext(ctx, "b2", buildPath(ctx, "b2"), installPath(ctx, "b2"))
+	m2.AddContextForSdk(ctx, AnySdkVersion, "c2", buildPath(ctx, "c2"), installPath(ctx, "c2"), m1)
 
-	lp.AddLibraryPath(ctx, "d", buildPath(ctx, "d"), installPath(ctx, "d"))
-	lp.AddLibraryPaths(lp2)
+	m3 := make(ClassLoaderContextMap)
+	m3.AddContext(ctx, "a3", buildPath(ctx, "a3"), installPath(ctx, "a3"))
+	m3.AddContext(ctx, "b3", buildPath(ctx, "b3"), installPath(ctx, "b3"))
 
-	lp3 := make(LibraryPaths)
-	lp3.AddLibraryPath(ctx, "f", buildPath(ctx, "f"), installPath(ctx, "f"))
-	lp3.AddLibraryPath(ctx, "a3", buildPath(ctx, "a3"), installPath(ctx, "a3"))
-	lp3.AddLibraryPath(ctx, "b3", buildPath(ctx, "b3"), installPath(ctx, "b3"))
-	lp.AddLibraryPaths(lp3)
+	m.AddContextForSdk(ctx, AnySdkVersion, "d", buildPath(ctx, "d"), installPath(ctx, "d"), m2)
+	// When the same library is both in conditional and unconditional context, it should be removed
+	// from conditional context.
+	m.AddContextForSdk(ctx, 42, "f", buildPath(ctx, "f"), installPath(ctx, "f"), nil)
+	m.AddContextForSdk(ctx, AnySdkVersion, "f", buildPath(ctx, "f"), installPath(ctx, "f"), nil)
+
+	// Merge map with implicit root library that is among toplevel contexts => does nothing.
+	m.AddContextMap(m1, "c")
+	// Merge map with implicit root library that is not among toplevel contexts => all subcontexts
+	// of the other map are added as toplevel contexts.
+	m.AddContextMap(m3, "m_g")
 
 	// Compatibility libraries with unknown install paths get default paths.
-	lp.AddLibraryPath(ctx, AndroidHidlBase, buildPath(ctx, AndroidHidlBase), nil)
-	lp.AddLibraryPath(ctx, AndroidHidlManager, buildPath(ctx, AndroidHidlManager), nil)
-	lp.AddLibraryPath(ctx, AndroidTestMock, buildPath(ctx, AndroidTestMock), nil)
-
-	module := testSystemModuleConfig(ctx, "test")
-	module.LibraryPaths = lp
-
-	m := make(classLoaderContextMap)
-	valid := true
-
-	ok, err := m.addLibs(ctx, AnySdkVersion, module, "a", "b", "c", "d", "a2", "b2", "c2", "a1", "b1", "f", "a3", "b3")
-	valid = valid && ok && err == nil
-
-	// Add compatibility libraries to conditional CLC for SDK level 29.
-	ok, err = m.addLibs(ctx, 29, module, AndroidHidlManager, AndroidHidlBase)
-	valid = valid && ok && err == nil
+	m.AddContextForSdk(ctx, 29, AndroidHidlManager, buildPath(ctx, AndroidHidlManager), nil, nil)
+	m.AddContextForSdk(ctx, 29, AndroidHidlBase, buildPath(ctx, AndroidHidlBase), nil, nil)
 
 	// Add "android.test.mock" to conditional CLC, observe that is gets removed because it is only
 	// needed as a compatibility library if "android.test.runner" is in CLC as well.
-	ok, err = m.addLibs(ctx, 30, module, AndroidTestMock)
-	valid = valid && ok && err == nil
+	m.AddContextForSdk(ctx, 30, AndroidTestMock, buildPath(ctx, AndroidTestMock), nil, nil)
 
-	// When the same library is both in conditional and unconditional context, it should be removed
-	// from conditional context.
-	ok, err = m.addLibs(ctx, 42, module, "f")
-	valid = valid && ok && err == nil
+	valid, validationError := validateClassLoaderContext(m)
 
-	fixConditionalClassLoaderContext(m)
+	fixClassLoaderContext(m)
 
 	var haveStr string
 	var havePaths android.Paths
 	var haveUsesLibs []string
-	if valid {
-		haveStr, havePaths = computeClassLoaderContext(ctx, m)
-		haveUsesLibs = m.usesLibs()
+	if valid && validationError == nil {
+		haveStr, havePaths = ComputeClassLoaderContext(m)
+		haveUsesLibs = m.UsesLibs()
 	}
 
 	// Test that validation is successful (all paths are known).
 	t.Run("validate", func(t *testing.T) {
-		if !valid {
+		if !(valid && validationError == nil) {
 			t.Errorf("invalid class loader context")
 		}
 	})
@@ -135,14 +123,14 @@
 			"PCL[/system/framework/" + AndroidHidlManager + ".jar]#" +
 			"PCL[/system/framework/" + AndroidHidlBase + ".jar]" +
 			" --host-context-for-sdk any " +
-			"PCL[out/a.jar]#PCL[out/b.jar]#PCL[out/c.jar]#PCL[out/d.jar]#" +
-			"PCL[out/a2.jar]#PCL[out/b2.jar]#PCL[out/c2.jar]#" +
-			"PCL[out/a1.jar]#PCL[out/b1.jar]#" +
+			"PCL[out/a.jar]#PCL[out/b.jar]#PCL[out/c.jar]#PCL[out/d.jar]" +
+			"{PCL[out/a2.jar]#PCL[out/b2.jar]#PCL[out/c2.jar]" +
+			"{PCL[out/a1.jar]#PCL[out/b1.jar]}}#" +
 			"PCL[out/f.jar]#PCL[out/a3.jar]#PCL[out/b3.jar]" +
 			" --target-context-for-sdk any " +
-			"PCL[/system/a.jar]#PCL[/system/b.jar]#PCL[/system/c.jar]#PCL[/system/d.jar]#" +
-			"PCL[/system/a2.jar]#PCL[/system/b2.jar]#PCL[/system/c2.jar]#" +
-			"PCL[/system/a1.jar]#PCL[/system/b1.jar]#" +
+			"PCL[/system/a.jar]#PCL[/system/b.jar]#PCL[/system/c.jar]#PCL[/system/d.jar]" +
+			"{PCL[/system/a2.jar]#PCL[/system/b2.jar]#PCL[/system/c2.jar]" +
+			"{PCL[/system/a1.jar]#PCL[/system/b1.jar]}}#" +
 			"PCL[/system/f.jar]#PCL[/system/a3.jar]#PCL[/system/b3.jar]"
 		if wantStr != haveStr {
 			t.Errorf("\nwant class loader context: %s\nhave class loader context: %s", wantStr, haveStr)
@@ -175,32 +163,50 @@
 // Test that an unexpected unknown build path causes immediate error.
 func TestCLCUnknownBuildPath(t *testing.T) {
 	ctx := testContext()
-	lp := make(LibraryPaths)
-	err := lp.addLibraryPath(ctx, "a", nil, nil, true)
-	checkError(t, err, "unknown build path to <uses-library> 'a'")
+	m := make(ClassLoaderContextMap)
+	err := m.addContext(ctx, AnySdkVersion, "a", nil, nil, true, nil)
+	checkError(t, err, "unknown build path to <uses-library> \"a\"")
 }
 
 // Test that an unexpected unknown install path causes immediate error.
 func TestCLCUnknownInstallPath(t *testing.T) {
 	ctx := testContext()
-	lp := make(LibraryPaths)
-	err := lp.addLibraryPath(ctx, "a", buildPath(ctx, "a"), nil, true)
-	checkError(t, err, "unknown install path to <uses-library> 'a'")
+	m := make(ClassLoaderContextMap)
+	err := m.addContext(ctx, AnySdkVersion, "a", buildPath(ctx, "a"), nil, true, nil)
+	checkError(t, err, "unknown install path to <uses-library> \"a\"")
 }
 
 func TestCLCMaybeAdd(t *testing.T) {
 	ctx := testContext()
 
-	lp := make(LibraryPaths)
+	m := make(ClassLoaderContextMap)
 	a := "a"
-	lp.MaybeAddLibraryPath(ctx, &a, nil, nil)
+	m.MaybeAddContext(ctx, &a, nil, nil)
 
-	module := testSystemModuleConfig(ctx, "test")
-	module.LibraryPaths = lp
+	// The library should be added to <uses-library> tags by the manifest_fixer.
+	t.Run("maybe add", func(t *testing.T) {
+		haveUsesLibs := m.UsesLibs()
+		wantUsesLibs := []string{"a"}
+		if !reflect.DeepEqual(wantUsesLibs, haveUsesLibs) {
+			t.Errorf("\nwant uses libs: %s\nhave uses libs: %s", wantUsesLibs, haveUsesLibs)
+		}
+	})
 
-	m := make(classLoaderContextMap)
-	_, err := m.addLibs(ctx, AnySdkVersion, module, "a")
-	checkError(t, err, "dexpreopt cannot find path for <uses-library> 'a'")
+	// But class loader context in such cases should raise an error on validation.
+	t.Run("validate", func(t *testing.T) {
+		_, err := validateClassLoaderContext(m)
+		checkError(t, err, "invalid path for <uses-library> \"a\"")
+	})
+}
+
+// An attempt to add conditional nested subcontext should fail.
+func TestCLCNestedConditional(t *testing.T) {
+	ctx := testContext()
+	m1 := make(ClassLoaderContextMap)
+	m1.AddContextForSdk(ctx, 42, "a", buildPath(ctx, "a"), installPath(ctx, "a"), nil)
+	m := make(ClassLoaderContextMap)
+	err := m.addContext(ctx, AnySdkVersion, "b", buildPath(ctx, "b"), installPath(ctx, "b"), true, m1)
+	checkError(t, err, "nested class loader context shouldn't have conditional part")
 }
 
 func checkError(t *testing.T, have error, want string) {
diff --git a/dexpreopt/config.go b/dexpreopt/config.go
index 03accc8..f52ecb4 100644
--- a/dexpreopt/config.go
+++ b/dexpreopt/config.go
@@ -114,10 +114,8 @@
 	ProfileIsTextListing bool
 	ProfileBootListing   android.OptionalPath
 
-	EnforceUsesLibraries  bool
-	OptionalUsesLibraries []string
-	UsesLibraries         []string
-	LibraryPaths          LibraryPaths
+	EnforceUsesLibraries bool
+	ClassLoaderContexts  ClassLoaderContextMap
 
 	Archs                   []android.ArchType
 	DexPreoptImages         []android.Path
@@ -265,7 +263,7 @@
 		DexPath                     string
 		ManifestPath                string
 		ProfileClassListing         string
-		LibraryPaths                jsonLibraryPaths
+		ClassLoaderContexts         jsonClassLoaderContextMap
 		DexPreoptImages             []string
 		DexPreoptImageLocations     []string
 		PreoptBootClassPathDexFiles []string
@@ -283,7 +281,7 @@
 	config.ModuleConfig.DexPath = constructPath(ctx, config.DexPath)
 	config.ModuleConfig.ManifestPath = constructPath(ctx, config.ManifestPath)
 	config.ModuleConfig.ProfileClassListing = android.OptionalPathForPath(constructPath(ctx, config.ProfileClassListing))
-	config.ModuleConfig.LibraryPaths = constructLibraryPaths(ctx, config.LibraryPaths)
+	config.ModuleConfig.ClassLoaderContexts = fromJsonClassLoaderContext(ctx, config.ClassLoaderContexts)
 	config.ModuleConfig.DexPreoptImages = constructPaths(ctx, config.DexPreoptImages)
 	config.ModuleConfig.DexPreoptImageLocations = config.DexPreoptImageLocations
 	config.ModuleConfig.PreoptBootClassPathDexFiles = constructPaths(ctx, config.PreoptBootClassPathDexFiles)
@@ -488,13 +486,7 @@
 		return
 	}
 
-	ctx.Build(pctx, android.BuildParams{
-		Rule:   android.WriteFile,
-		Output: android.PathForOutput(ctx, "dexpreopt_soong.config"),
-		Args: map[string]string{
-			"content": string(data),
-		},
-	})
+	android.WriteFileRule(ctx, android.PathForOutput(ctx, "dexpreopt_soong.config"), string(data))
 }
 
 func (s *globalSoongConfigSingleton) MakeVars(ctx android.MakeVarsContext) {
diff --git a/dexpreopt/dexpreopt.go b/dexpreopt/dexpreopt.go
index a07f1fa..65380fe 100644
--- a/dexpreopt/dexpreopt.go
+++ b/dexpreopt/dexpreopt.go
@@ -81,16 +81,18 @@
 	}
 
 	if !dexpreoptDisabled(ctx, global, module) {
-		if clc, err := genClassLoaderContext(ctx, global, module); err != nil {
+		if valid, err := validateClassLoaderContext(module.ClassLoaderContexts); err != nil {
 			android.ReportPathErrorf(ctx, err.Error())
-		} else if clc != nil {
+		} else if valid {
+			fixClassLoaderContext(module.ClassLoaderContexts)
+
 			appImage := (generateProfile || module.ForceCreateAppImage || global.DefaultAppImages) &&
 				!module.NoCreateAppImage
 
 			generateDM := shouldGenerateDM(module, global)
 
 			for archIdx, _ := range module.Archs {
-				dexpreoptCommand(ctx, globalSoong, global, module, rule, archIdx, *clc, profile, appImage, generateDM)
+				dexpreoptCommand(ctx, globalSoong, global, module, rule, archIdx, profile, appImage, generateDM)
 			}
 		}
 	}
@@ -197,8 +199,8 @@
 }
 
 func dexpreoptCommand(ctx android.PathContext, globalSoong *GlobalSoongConfig, global *GlobalConfig,
-	module *ModuleConfig, rule *android.RuleBuilder, archIdx int, classLoaderContexts classLoaderContextMap,
-	profile android.WritablePath, appImage bool, generateDM bool) {
+	module *ModuleConfig, rule *android.RuleBuilder, archIdx int, profile android.WritablePath,
+	appImage bool, generateDM bool) {
 
 	arch := module.Archs[archIdx]
 
@@ -235,6 +237,16 @@
 	rule.Command().FlagWithOutput("rm -f ", odexPath)
 
 	if jarIndex := android.IndexList(module.Name, systemServerJars); jarIndex >= 0 {
+		// System server jars should be dexpreopted together: class loader context of each jar
+		// should include all preceding jars on the system server classpath.
+
+		var clcHost android.Paths
+		var clcTarget []string
+		for _, lib := range systemServerJars[:jarIndex] {
+			clcHost = append(clcHost, SystemServerDexJarHostPath(ctx, lib))
+			clcTarget = append(clcTarget, filepath.Join("/system/framework", lib+".jar"))
+		}
+
 		// Copy the system server jar to a predefined location where dex2oat will find it.
 		dexPathHost := SystemServerDexJarHostPath(ctx, module.Name)
 		rule.Command().Text("mkdir -p").Flag(filepath.Dir(dexPathHost.String()))
@@ -242,11 +254,11 @@
 
 		checkSystemServerOrder(ctx, jarIndex)
 
-		clc := classLoaderContexts[AnySdkVersion]
 		rule.Command().
-			Text("class_loader_context_arg=--class-loader-context=PCL[" + strings.Join(clc.Host.Strings(), ":") + "]").
-			Implicits(clc.Host).
-			Text("stored_class_loader_context_arg=--stored-class-loader-context=PCL[" + strings.Join(clc.Target, ":") + "]")
+			Text("class_loader_context_arg=--class-loader-context=PCL[" + strings.Join(clcHost.Strings(), ":") + "]").
+			Implicits(clcHost).
+			Text("stored_class_loader_context_arg=--stored-class-loader-context=PCL[" + strings.Join(clcTarget, ":") + "]")
+
 	} else if module.EnforceUsesLibraries {
 		// Generate command that saves target SDK version in a shell variable.
 		if module.ManifestPath != nil {
@@ -266,13 +278,15 @@
 		}
 
 		// Generate command that saves host and target class loader context in shell variables.
-		clc, paths := computeClassLoaderContext(ctx, classLoaderContexts)
+		clc, paths := ComputeClassLoaderContext(module.ClassLoaderContexts)
 		cmd := rule.Command().
 			Text(`eval "$(`).Tool(globalSoong.ConstructContext).
 			Text(` --target-sdk-version ${target_sdk_version}`).
 			Text(clc).Implicits(paths)
 		cmd.Text(`)"`)
+
 	} else {
+		// Other libraries or APKs for which the exact <uses-library> list is unknown.
 		// Pass special class loader context to skip the classpath and collision check.
 		// This will get removed once LOCAL_USES_LIBRARIES is enforced.
 		// Right now LOCAL_USES_LIBRARIES is opt in, for the case where it's not specified we still default
diff --git a/dexpreopt/dexpreopt_test.go b/dexpreopt/dexpreopt_test.go
index ec31549..feabd70 100644
--- a/dexpreopt/dexpreopt_test.go
+++ b/dexpreopt/dexpreopt_test.go
@@ -44,9 +44,7 @@
 		ProfileClassListing:             android.OptionalPath{},
 		ProfileIsTextListing:            false,
 		EnforceUsesLibraries:            false,
-		OptionalUsesLibraries:           nil,
-		UsesLibraries:                   nil,
-		LibraryPaths:                    nil,
+		ClassLoaderContexts:             nil,
 		Archs:                           []android.ArchType{android.Arm},
 		DexPreoptImages:                 android.Paths{android.PathForTesting("system/framework/arm/boot.art")},
 		DexPreoptImagesDeps:             []android.OutputPaths{android.OutputPaths{}},
diff --git a/java/aar.go b/java/aar.go
index 157d677..7c3840b 100644
--- a/java/aar.go
+++ b/java/aar.go
@@ -109,7 +109,6 @@
 	useEmbeddedNativeLibs   bool
 	useEmbeddedDex          bool
 	usesNonSdkApis          bool
-	sdkLibraries            dexpreopt.LibraryPaths
 	hasNoCode               bool
 	LoggingParent           string
 	resourceFiles           android.Paths
@@ -259,12 +258,11 @@
 		CommandDeps: []string{"${config.Zip2ZipCmd}"},
 	})
 
-func (a *aapt) buildActions(ctx android.ModuleContext, sdkContext sdkContext, extraLinkFlags ...string) {
+func (a *aapt) buildActions(ctx android.ModuleContext, sdkContext sdkContext,
+	sdkLibraries dexpreopt.ClassLoaderContextMap, extraLinkFlags ...string) {
 
-	transitiveStaticLibs, transitiveStaticLibManifests, staticRRODirs, assetPackages, libDeps, libFlags, sdkLibraries :=
-		aaptLibs(ctx, sdkContext)
-
-	a.sdkLibraries = sdkLibraries
+	transitiveStaticLibs, transitiveStaticLibManifests, staticRRODirs, assetPackages, libDeps, libFlags :=
+		aaptLibs(ctx, sdkContext, sdkLibraries)
 
 	// App manifest file
 	manifestFile := proptools.StringDefault(a.aaptProperties.Manifest, "AndroidManifest.xml")
@@ -391,29 +389,31 @@
 }
 
 // aaptLibs collects libraries from dependencies and sdk_version and converts them into paths
-func aaptLibs(ctx android.ModuleContext, sdkContext sdkContext) (transitiveStaticLibs, transitiveStaticLibManifests android.Paths,
-	staticRRODirs []rroDir, assets, deps android.Paths, flags []string, sdkLibraries dexpreopt.LibraryPaths) {
+func aaptLibs(ctx android.ModuleContext, sdkContext sdkContext, sdkLibraries dexpreopt.ClassLoaderContextMap) (
+	transitiveStaticLibs, transitiveStaticLibManifests android.Paths, staticRRODirs []rroDir, assets, deps android.Paths, flags []string) {
 
 	var sharedLibs android.Paths
 
+	if sdkLibraries == nil {
+		// Not all callers need to compute class loader context, those who don't just pass nil.
+		// Create a temporary class loader context here (it will be computed, but not used).
+		sdkLibraries = make(dexpreopt.ClassLoaderContextMap)
+	}
+
 	sdkDep := decodeSdkDep(ctx, sdkContext)
 	if sdkDep.useFiles {
 		sharedLibs = append(sharedLibs, sdkDep.jars...)
 	}
 
-	sdkLibraries = make(dexpreopt.LibraryPaths)
-
 	ctx.VisitDirectDeps(func(module android.Module) {
+		depName := ctx.OtherModuleName(module)
+
 		var exportPackage android.Path
 		aarDep, _ := module.(AndroidLibraryDependency)
 		if aarDep != nil {
 			exportPackage = aarDep.ExportPackage()
 		}
 
-		if dep, ok := module.(Dependency); ok {
-			sdkLibraries.AddLibraryPaths(dep.ExportedSdkLibs())
-		}
-
 		switch ctx.OtherModuleDependencyTag(module) {
 		case instrumentationForTag:
 			// Nothing, instrumentationForTag is treated as libTag for javac but not for aapt2.
@@ -426,7 +426,7 @@
 			// (including the java_sdk_library) itself then append any implicit sdk library
 			// names to the list of sdk libraries to be added to the manifest.
 			if component, ok := module.(SdkLibraryComponentDependency); ok {
-				sdkLibraries.MaybeAddLibraryPath(ctx, component.OptionalImplicitSdkLibrary(),
+				sdkLibraries.MaybeAddContext(ctx, component.OptionalImplicitSdkLibrary(),
 					component.DexJarBuildPath(), component.DexJarInstallPath())
 			}
 
@@ -439,7 +439,7 @@
 				transitiveStaticLibs = append(transitiveStaticLibs, aarDep.ExportedStaticPackages()...)
 				transitiveStaticLibs = append(transitiveStaticLibs, exportPackage)
 				transitiveStaticLibManifests = append(transitiveStaticLibManifests, aarDep.ExportedManifests()...)
-				sdkLibraries.AddLibraryPaths(aarDep.ExportedSdkLibs())
+				sdkLibraries.AddContextMap(aarDep.ExportedSdkLibs(), depName)
 				if aarDep.ExportedAssets().Valid() {
 					assets = append(assets, aarDep.ExportedAssets().Path())
 				}
@@ -457,6 +457,12 @@
 				}
 			}
 		}
+
+		// Add nested dependencies after processing the direct dependency: if it is a <uses-library>,
+		// nested context is added as its subcontext, and should not be re-added at the top-level.
+		if dep, ok := module.(Dependency); ok {
+			sdkLibraries.AddContextMap(dep.ExportedSdkLibs(), depName)
+		}
 	})
 
 	deps = append(deps, sharedLibs...)
@@ -473,7 +479,7 @@
 	transitiveStaticLibs = android.FirstUniquePaths(transitiveStaticLibs)
 	transitiveStaticLibManifests = android.FirstUniquePaths(transitiveStaticLibManifests)
 
-	return transitiveStaticLibs, transitiveStaticLibManifests, staticRRODirs, assets, deps, flags, sdkLibraries
+	return transitiveStaticLibs, transitiveStaticLibManifests, staticRRODirs, assets, deps, flags
 }
 
 type AndroidLibrary struct {
@@ -508,8 +514,8 @@
 
 func (a *AndroidLibrary) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	a.aapt.isLibrary = true
-	a.aapt.buildActions(ctx, sdkContext(a))
-	a.exportedSdkLibs = a.aapt.sdkLibraries
+	a.exportedSdkLibs = make(dexpreopt.ClassLoaderContextMap)
+	a.aapt.buildActions(ctx, sdkContext(a), a.exportedSdkLibs)
 
 	a.hideApexVariantFromMake = !ctx.Provider(android.ApexInfoProvider).(android.ApexInfo).IsForPlatform()
 
@@ -781,12 +787,11 @@
 	linkFlags = append(linkFlags, "--manifest "+a.manifest.String())
 	linkDeps = append(linkDeps, a.manifest)
 
-	transitiveStaticLibs, staticLibManifests, staticRRODirs, transitiveAssets, libDeps, libFlags, sdkLibraries :=
-		aaptLibs(ctx, sdkContext(a))
+	transitiveStaticLibs, staticLibManifests, staticRRODirs, transitiveAssets, libDeps, libFlags :=
+		aaptLibs(ctx, sdkContext(a), nil)
 
 	_ = staticLibManifests
 	_ = staticRRODirs
-	_ = sdkLibraries
 
 	linkDeps = append(linkDeps, libDeps...)
 	linkFlags = append(linkFlags, libFlags...)
@@ -827,7 +832,7 @@
 	return nil
 }
 
-func (a *AARImport) ExportedSdkLibs() dexpreopt.LibraryPaths {
+func (a *AARImport) ExportedSdkLibs() dexpreopt.ClassLoaderContextMap {
 	return nil
 }
 
diff --git a/java/android_manifest.go b/java/android_manifest.go
index 62cd112..6b39c35 100644
--- a/java/android_manifest.go
+++ b/java/android_manifest.go
@@ -43,8 +43,9 @@
 	"args", "libs")
 
 // Uses manifest_fixer.py to inject minSdkVersion, etc. into an AndroidManifest.xml
-func manifestFixer(ctx android.ModuleContext, manifest android.Path, sdkContext sdkContext, sdkLibraries dexpreopt.LibraryPaths,
-	isLibrary, useEmbeddedNativeLibs, usesNonSdkApis, useEmbeddedDex, hasNoCode bool, loggingParent string) android.Path {
+func manifestFixer(ctx android.ModuleContext, manifest android.Path, sdkContext sdkContext,
+	sdkLibraries dexpreopt.ClassLoaderContextMap, isLibrary, useEmbeddedNativeLibs, usesNonSdkApis,
+	useEmbeddedDex, hasNoCode bool, loggingParent string) android.Path {
 
 	var args []string
 	if isLibrary {
@@ -70,7 +71,7 @@
 		args = append(args, "--use-embedded-dex")
 	}
 
-	for _, usesLib := range android.SortedStringKeys(sdkLibraries) {
+	for _, usesLib := range sdkLibraries.UsesLibs() {
 		if inList(usesLib, dexpreopt.OptionalCompatUsesLibs) {
 			args = append(args, "--optional-uses-library", usesLib)
 		} else {
diff --git a/java/androidmk.go b/java/androidmk.go
index e1a661f..c606245 100644
--- a/java/androidmk.go
+++ b/java/androidmk.go
@@ -115,7 +115,7 @@
 						entries.SetPath("LOCAL_SOONG_JACOCO_REPORT_CLASSES_JAR", library.jacocoReportClassesFile)
 					}
 
-					entries.AddStrings("LOCAL_EXPORT_SDK_LIBRARIES", android.SortedStringKeys(library.exportedSdkLibs)...)
+					entries.AddStrings("LOCAL_EXPORT_SDK_LIBRARIES", library.exportedSdkLibs.UsesLibs()...)
 
 					if len(library.additionalCheckedModules) != 0 {
 						entries.AddStrings("LOCAL_ADDITIONAL_CHECKED_MODULE", library.additionalCheckedModules.Strings()...)
diff --git a/java/app.go b/java/app.go
index c24e0c5..9ff413c 100755
--- a/java/app.go
+++ b/java/app.go
@@ -565,9 +565,8 @@
 	aaptLinkFlags = append(aaptLinkFlags, a.additionalAaptFlags...)
 
 	a.aapt.splitNames = a.appProperties.Package_splits
-	a.aapt.sdkLibraries = a.exportedSdkLibs
 	a.aapt.LoggingParent = String(a.overridableAppProperties.Logging_parent)
-	a.aapt.buildActions(ctx, sdkContext(a), aaptLinkFlags...)
+	a.aapt.buildActions(ctx, sdkContext(a), a.exportedSdkLibs, aaptLinkFlags...)
 
 	// apps manifests are handled by aapt, don't let Module see them
 	a.properties.Manifest = nil
@@ -601,7 +600,7 @@
 	return android.PathForModuleInstall(ctx, installDir, a.installApkName+".apk")
 }
 
-func (a *AndroidApp) dexBuildActions(ctx android.ModuleContext, sdkLibs dexpreopt.LibraryPaths) android.Path {
+func (a *AndroidApp) dexBuildActions(ctx android.ModuleContext) android.Path {
 	a.dexpreopter.installPath = a.installPath(ctx)
 	if a.dexProperties.Uncompress_dex == nil {
 		// If the value was not force-set by the user, use reasonable default based on the module.
@@ -609,12 +608,8 @@
 	}
 	a.dexpreopter.uncompressedDex = *a.dexProperties.Uncompress_dex
 	a.dexpreopter.enforceUsesLibs = a.usesLibrary.enforceUsesLibraries()
-	a.dexpreopter.usesLibs = a.usesLibrary.usesLibraryProperties.Uses_libs
-	a.dexpreopter.optionalUsesLibs = a.usesLibrary.presentOptionalUsesLibs(ctx)
-	a.dexpreopter.libraryPaths = a.usesLibrary.usesLibraryPaths(ctx)
-	a.dexpreopter.libraryPaths.AddLibraryPaths(sdkLibs)
+	a.dexpreopter.classLoaderContexts = a.exportedSdkLibs
 	a.dexpreopter.manifestFile = a.mergedManifestFile
-	a.exportedSdkLibs = make(dexpreopt.LibraryPaths)
 
 	if ctx.ModuleName() != "framework-res" {
 		a.Module.compile(ctx, a.aaptSrcJar)
@@ -784,6 +779,8 @@
 		a.aapt.noticeFile = a.noticeOutputs.HtmlGzOutput
 	}
 
+	a.exportedSdkLibs = a.usesLibrary.classLoaderContextForUsesLibDeps(ctx)
+
 	// Process all building blocks, from AAPT to certificates.
 	a.aaptBuildActions(ctx)
 
@@ -791,7 +788,7 @@
 	a.usesLibrary.freezeEnforceUsesLibraries()
 
 	// Add implicit SDK libraries to <uses-library> list.
-	for _, usesLib := range android.SortedStringKeys(a.aapt.sdkLibraries) {
+	for _, usesLib := range a.exportedSdkLibs.UsesLibs() {
 		a.usesLibrary.addLib(usesLib, inList(usesLib, dexpreopt.OptionalCompatUsesLibs))
 	}
 
@@ -808,7 +805,7 @@
 	a.linter.resources = a.aapt.resourceFiles
 	a.linter.buildModuleReportZip = ctx.Config().UnbundledBuildApps()
 
-	dexJarFile := a.dexBuildActions(ctx, a.aapt.sdkLibraries)
+	dexJarFile := a.dexBuildActions(ctx)
 
 	jniLibs, certificateDeps := collectAppDeps(ctx, a, a.shouldEmbedJnis(ctx), !Bool(a.appProperties.Jni_uses_platform_apis))
 	jniJarFile := a.jniBuildActions(jniLibs, ctx)
@@ -1540,9 +1537,7 @@
 	a.dexpreopter.uncompressedDex = a.shouldUncompressDex(ctx)
 
 	a.dexpreopter.enforceUsesLibs = a.usesLibrary.enforceUsesLibraries()
-	a.dexpreopter.usesLibs = a.usesLibrary.usesLibraryProperties.Uses_libs
-	a.dexpreopter.optionalUsesLibs = a.usesLibrary.presentOptionalUsesLibs(ctx)
-	a.dexpreopter.libraryPaths = a.usesLibrary.usesLibraryPaths(ctx)
+	a.dexpreopter.classLoaderContexts = a.usesLibrary.classLoaderContextForUsesLibDeps(ctx)
 
 	dexOutput := a.dexpreopter.dexpreopt(ctx, jnisUncompressed)
 	if a.dexpreopter.uncompressedDex {
@@ -1852,7 +1847,7 @@
 		aaptLinkFlags = append(aaptLinkFlags,
 			"--rename-overlay-target-package "+*r.overridableProperties.Target_package_name)
 	}
-	r.aapt.buildActions(ctx, r, aaptLinkFlags...)
+	r.aapt.buildActions(ctx, r, nil, aaptLinkFlags...)
 
 	// Sign the built package
 	_, certificates := collectAppDeps(ctx, r, false, false)
@@ -1976,17 +1971,18 @@
 	return optionalUsesLibs
 }
 
-// usesLibraryPaths returns a map of module names of shared library dependencies to the paths
+// Returns a map of module names of shared library dependencies to the paths
 // to their dex jars on host and on device.
-func (u *usesLibrary) usesLibraryPaths(ctx android.ModuleContext) dexpreopt.LibraryPaths {
-	usesLibPaths := make(dexpreopt.LibraryPaths)
+func (u *usesLibrary) classLoaderContextForUsesLibDeps(ctx android.ModuleContext) dexpreopt.ClassLoaderContextMap {
+	clcMap := make(dexpreopt.ClassLoaderContextMap)
 
 	if !ctx.Config().UnbundledBuild() {
 		ctx.VisitDirectDeps(func(m android.Module) {
-			if _, ok := ctx.OtherModuleDependencyTag(m).(usesLibraryDependencyTag); ok {
+			if tag, ok := ctx.OtherModuleDependencyTag(m).(usesLibraryDependencyTag); ok {
 				dep := ctx.OtherModuleName(m)
 				if lib, ok := m.(Dependency); ok {
-					usesLibPaths.AddLibraryPath(ctx, dep, lib.DexJarBuildPath(), lib.DexJarInstallPath())
+					clcMap.AddContextForSdk(ctx, tag.sdkVersion, dep,
+						lib.DexJarBuildPath(), lib.DexJarInstallPath(), lib.ExportedSdkLibs())
 				} else if ctx.Config().AllowMissingDependencies() {
 					ctx.AddMissingDependencies([]string{dep})
 				} else {
@@ -1996,7 +1992,7 @@
 		})
 	}
 
-	return usesLibPaths
+	return clcMap
 }
 
 // enforceUsesLibraries returns true of <uses-library> tags should be checked against uses_libs and optional_uses_libs
diff --git a/java/app_test.go b/java/app_test.go
index 446050d..6429ab8 100644
--- a/java/app_test.go
+++ b/java/app_test.go
@@ -2815,11 +2815,11 @@
 	// Test that all present libraries are preopted, including implicit SDK dependencies, possibly stubs
 	cmd = app.Rule("dexpreopt").RuleParams.Command
 	w := `--target-context-for-sdk any ` +
-		`PCL[/system/framework/foo.jar]#` +
-		`PCL[/system/framework/quuz.jar]#` +
 		`PCL[/system/framework/qux.jar]#` +
-		`PCL[/system/framework/runtime-library.jar]#` +
-		`PCL[/system/framework/bar.jar]`
+		`PCL[/system/framework/quuz.jar]#` +
+		`PCL[/system/framework/foo.jar]#` +
+		`PCL[/system/framework/bar.jar]#` +
+		`PCL[/system/framework/runtime-library.jar]`
 	if !strings.Contains(cmd, w) {
 		t.Errorf("wanted %q in %q", w, cmd)
 	}
diff --git a/java/builder.go b/java/builder.go
index 3043e46..cd35245 100644
--- a/java/builder.go
+++ b/java/builder.go
@@ -572,14 +572,7 @@
 }
 
 func GenerateMainClassManifest(ctx android.ModuleContext, outputFile android.WritablePath, mainClass string) {
-	ctx.Build(pctx, android.BuildParams{
-		Rule:        android.WriteFile,
-		Description: "manifest",
-		Output:      outputFile,
-		Args: map[string]string{
-			"content": "Main-Class: " + mainClass + "\n",
-		},
-	})
+	android.WriteFileRule(ctx, outputFile, "Main-Class: "+mainClass+"\n")
 }
 
 func TransformZipAlign(ctx android.ModuleContext, outputFile android.WritablePath, inputFile android.Path) {
diff --git a/java/device_host_converter.go b/java/device_host_converter.go
index 40a2280..d8b617e 100644
--- a/java/device_host_converter.go
+++ b/java/device_host_converter.go
@@ -163,7 +163,7 @@
 	return nil
 }
 
-func (d *DeviceHostConverter) ExportedSdkLibs() dexpreopt.LibraryPaths {
+func (d *DeviceHostConverter) ExportedSdkLibs() dexpreopt.ClassLoaderContextMap {
 	return nil
 }
 
diff --git a/java/dexpreopt.go b/java/dexpreopt.go
index 20dbc66..a21fb76 100644
--- a/java/dexpreopt.go
+++ b/java/dexpreopt.go
@@ -33,11 +33,9 @@
 	isTest              bool
 	isPresignedPrebuilt bool
 
-	manifestFile     android.Path
-	usesLibs         []string
-	optionalUsesLibs []string
-	enforceUsesLibs  bool
-	libraryPaths     dexpreopt.LibraryPaths
+	manifestFile        android.Path
+	enforceUsesLibs     bool
+	classLoaderContexts dexpreopt.ClassLoaderContextMap
 
 	builtInstalled string
 }
@@ -193,10 +191,8 @@
 		ProfileIsTextListing: profileIsTextListing,
 		ProfileBootListing:   profileBootListing,
 
-		EnforceUsesLibraries:  d.enforceUsesLibs,
-		OptionalUsesLibraries: d.optionalUsesLibs,
-		UsesLibraries:         d.usesLibs,
-		LibraryPaths:          d.libraryPaths,
+		EnforceUsesLibraries: d.enforceUsesLibs,
+		ClassLoaderContexts:  d.classLoaderContexts,
 
 		Archs:                   archs,
 		DexPreoptImages:         images,
diff --git a/java/dexpreopt_bootjars.go b/java/dexpreopt_bootjars.go
index 629d34f..f9975ba 100644
--- a/java/dexpreopt_bootjars.go
+++ b/java/dexpreopt_bootjars.go
@@ -651,14 +651,8 @@
 		updatableBcpPackagesName := "updatable-bcp-packages.txt"
 		updatableBcpPackages := image.dir.Join(ctx, updatableBcpPackagesName)
 
-		ctx.Build(pctx, android.BuildParams{
-			Rule:   android.WriteFile,
-			Output: updatableBcpPackages,
-			Args: map[string]string{
-				// WriteFile automatically adds the last end-of-line.
-				"content": strings.Join(updatablePackages, "\\n"),
-			},
-		})
+		// WriteFileRule automatically adds the last end-of-line.
+		android.WriteFileRule(ctx, updatableBcpPackages, strings.Join(updatablePackages, "\n"))
 
 		rule := android.NewRuleBuilder()
 		rule.MissingDeps(missingDeps)
@@ -720,13 +714,7 @@
 func writeGlobalConfigForMake(ctx android.SingletonContext, path android.WritablePath) {
 	data := dexpreopt.GetGlobalConfigRawData(ctx)
 
-	ctx.Build(pctx, android.BuildParams{
-		Rule:   android.WriteFile,
-		Output: path,
-		Args: map[string]string{
-			"content": string(data),
-		},
-	})
+	android.WriteFileRule(ctx, path, string(data))
 }
 
 // Export paths for default boot image to Make
diff --git a/java/java.go b/java/java.go
index 9f09051..d6dc148 100644
--- a/java/java.go
+++ b/java/java.go
@@ -416,8 +416,8 @@
 	// manifest file to use instead of properties.Manifest
 	overrideManifest android.OptionalPath
 
-	// map of SDK libs exported by this java module to their build and install paths
-	exportedSdkLibs dexpreopt.LibraryPaths
+	// map of SDK version to class loader context
+	exportedSdkLibs dexpreopt.ClassLoaderContextMap
 
 	// list of plugins that this java module is exporting
 	exportedPluginJars android.Paths
@@ -509,7 +509,7 @@
 	ImplementationJars() android.Paths
 	ResourceJars() android.Paths
 	AidlIncludeDirs() android.Paths
-	ExportedSdkLibs() dexpreopt.LibraryPaths
+	ExportedSdkLibs() dexpreopt.ClassLoaderContextMap
 	ExportedPlugins() (android.Paths, []string)
 	SrcJarArgs() ([]string, android.Paths)
 	BaseModuleName() string
@@ -1027,7 +1027,8 @@
 			case libTag:
 				deps.classpath = append(deps.classpath, dep.SdkHeaderJars(ctx, j.sdkVersion())...)
 				// names of sdk libs that are directly depended are exported
-				j.exportedSdkLibs.MaybeAddLibraryPath(ctx, dep.OptionalImplicitSdkLibrary(), dep.DexJarBuildPath(), dep.DexJarInstallPath())
+				j.exportedSdkLibs.MaybeAddContext(ctx, dep.OptionalImplicitSdkLibrary(),
+					dep.DexJarBuildPath(), dep.DexJarInstallPath())
 			case staticLibTag:
 				ctx.ModuleErrorf("dependency on java_sdk_library %q can only be in libs", otherName)
 			}
@@ -1038,7 +1039,7 @@
 			case libTag, instrumentationForTag:
 				deps.classpath = append(deps.classpath, dep.HeaderJars()...)
 				// sdk lib names from dependencies are re-exported
-				j.exportedSdkLibs.AddLibraryPaths(dep.ExportedSdkLibs())
+				j.exportedSdkLibs.AddContextMap(dep.ExportedSdkLibs(), otherName)
 				deps.aidlIncludeDirs = append(deps.aidlIncludeDirs, dep.AidlIncludeDirs()...)
 				pluginJars, pluginClasses := dep.ExportedPlugins()
 				addPlugins(&deps, pluginJars, pluginClasses...)
@@ -1050,7 +1051,7 @@
 				deps.staticHeaderJars = append(deps.staticHeaderJars, dep.HeaderJars()...)
 				deps.staticResourceJars = append(deps.staticResourceJars, dep.ResourceJars()...)
 				// sdk lib names from dependencies are re-exported
-				j.exportedSdkLibs.AddLibraryPaths(dep.ExportedSdkLibs())
+				j.exportedSdkLibs.AddContextMap(dep.ExportedSdkLibs(), otherName)
 				deps.aidlIncludeDirs = append(deps.aidlIncludeDirs, dep.AidlIncludeDirs()...)
 				pluginJars, pluginClasses := dep.ExportedPlugins()
 				addPlugins(&deps, pluginJars, pluginClasses...)
@@ -1902,7 +1903,7 @@
 	return j.exportAidlIncludeDirs
 }
 
-func (j *Module) ExportedSdkLibs() dexpreopt.LibraryPaths {
+func (j *Module) ExportedSdkLibs() dexpreopt.ClassLoaderContextMap {
 	return j.exportedSdkLibs
 }
 
@@ -2041,7 +2042,7 @@
 		j.dexProperties.Uncompress_dex = proptools.BoolPtr(shouldUncompressDex(ctx, &j.dexpreopter))
 	}
 	j.dexpreopter.uncompressedDex = *j.dexProperties.Uncompress_dex
-	j.exportedSdkLibs = make(dexpreopt.LibraryPaths)
+	j.exportedSdkLibs = make(dexpreopt.ClassLoaderContextMap)
 	j.compile(ctx, nil)
 
 	// Collect the module directory for IDE info in java/jdeps.go.
@@ -2061,11 +2062,12 @@
 	// add the name of that java_sdk_library to the exported sdk libs to make sure
 	// that, if necessary, a <uses-library> element for that java_sdk_library is
 	// added to the Android manifest.
-	j.exportedSdkLibs.MaybeAddLibraryPath(ctx, j.OptionalImplicitSdkLibrary(), j.DexJarBuildPath(), j.DexJarInstallPath())
+	j.exportedSdkLibs.MaybeAddContext(ctx, j.OptionalImplicitSdkLibrary(),
+		j.DexJarBuildPath(), j.DexJarInstallPath())
 
 	// A non-SDK library may provide a <uses-library> (the name may be different from the module name).
 	if lib := proptools.String(j.usesLibraryProperties.Provides_uses_lib); lib != "" {
-		j.exportedSdkLibs.AddLibraryPath(ctx, lib, j.DexJarBuildPath(), j.DexJarInstallPath())
+		j.exportedSdkLibs.AddContext(ctx, lib, j.DexJarBuildPath(), j.DexJarInstallPath())
 	}
 
 	j.distFiles = j.GenerateTaggedDistFiles(ctx)
@@ -2644,7 +2646,7 @@
 	dexJarFile android.Path
 
 	combinedClasspathFile android.Path
-	exportedSdkLibs       dexpreopt.LibraryPaths
+	exportedSdkLibs       dexpreopt.ClassLoaderContextMap
 	exportAidlIncludeDirs android.Paths
 
 	hideApexVariantFromMake bool
@@ -2719,7 +2721,7 @@
 		TransformJetifier(ctx, outputFile, inputFile)
 	}
 	j.combinedClasspathFile = outputFile
-	j.exportedSdkLibs = make(dexpreopt.LibraryPaths)
+	j.exportedSdkLibs = make(dexpreopt.ClassLoaderContextMap)
 
 	var flags javaBuilderFlags
 
@@ -2733,7 +2735,7 @@
 			case libTag, staticLibTag:
 				flags.classpath = append(flags.classpath, dep.HeaderJars()...)
 				// sdk lib names from dependencies are re-exported
-				j.exportedSdkLibs.AddLibraryPaths(dep.ExportedSdkLibs())
+				j.exportedSdkLibs.AddContextMap(dep.ExportedSdkLibs(), otherName)
 			case bootClasspathTag:
 				flags.bootClasspath = append(flags.bootClasspath, dep.HeaderJars()...)
 			}
@@ -2742,7 +2744,8 @@
 			case libTag:
 				flags.classpath = append(flags.classpath, dep.SdkHeaderJars(ctx, j.sdkVersion())...)
 				// names of sdk libs that are directly depended are exported
-				j.exportedSdkLibs.AddLibraryPath(ctx, otherName, dep.DexJarBuildPath(), dep.DexJarInstallPath())
+				j.exportedSdkLibs.AddContext(ctx, otherName,
+					dep.DexJarBuildPath(), dep.DexJarInstallPath())
 			}
 		}
 	})
@@ -2757,7 +2760,8 @@
 	// add the name of that java_sdk_library to the exported sdk libs to make sure
 	// that, if necessary, a <uses-library> element for that java_sdk_library is
 	// added to the Android manifest.
-	j.exportedSdkLibs.MaybeAddLibraryPath(ctx, j.OptionalImplicitSdkLibrary(), outputFile, installFile)
+	j.exportedSdkLibs.MaybeAddContext(ctx, j.OptionalImplicitSdkLibrary(),
+		outputFile, installFile)
 
 	j.exportAidlIncludeDirs = android.PathsForModuleSrc(ctx, j.properties.Aidl.Export_include_dirs)
 
@@ -2839,7 +2843,7 @@
 	return j.exportAidlIncludeDirs
 }
 
-func (j *Import) ExportedSdkLibs() dexpreopt.LibraryPaths {
+func (j *Import) ExportedSdkLibs() dexpreopt.ClassLoaderContextMap {
 	return j.exportedSdkLibs
 }
 
diff --git a/java/java_test.go b/java/java_test.go
index 2a27922..4594b81 100644
--- a/java/java_test.go
+++ b/java/java_test.go
@@ -1593,8 +1593,8 @@
 	// test if baz has exported SDK lib names foo and bar to qux
 	qux := ctx.ModuleForTests("qux", "android_common")
 	if quxLib, ok := qux.Module().(*Library); ok {
-		sdkLibs := android.SortedStringKeys(quxLib.ExportedSdkLibs())
-		if w := []string{"bar", "foo", "fred", "quuz"}; !reflect.DeepEqual(w, sdkLibs) {
+		sdkLibs := quxLib.ExportedSdkLibs().UsesLibs()
+		if w := []string{"foo", "bar", "fred", "quuz"}; !reflect.DeepEqual(w, sdkLibs) {
 			t.Errorf("qux should export %q but exports %q", w, sdkLibs)
 		}
 	}
diff --git a/java/robolectric.go b/java/robolectric.go
index 04fc117..62d1d99 100644
--- a/java/robolectric.go
+++ b/java/robolectric.go
@@ -389,8 +389,10 @@
 		}
 		runtimeFromSourceJar := android.OutputFileForModule(ctx, runtimeFromSourceModule, "")
 
+		// TODO(murj) Update this to ctx.Config().PlatformSdkCodename() once the platform
+		// classes like android.os.Build are updated to S.
 		runtimeName := fmt.Sprintf("android-all-%s-robolectric-r0.jar",
-			ctx.Config().PlatformSdkCodename())
+			"R")
 		installedRuntime := ctx.InstallFile(androidAllDir, runtimeName, runtimeFromSourceJar)
 		r.runtimes = append(r.runtimes, installedRuntime)
 	}
diff --git a/python/python.go b/python/python.go
index 945e264..e4c8e94 100644
--- a/python/python.go
+++ b/python/python.go
@@ -300,7 +300,7 @@
 }
 
 func (p *Module) hasSrcExt(ctx android.BottomUpMutatorContext, ext string) bool {
-	return hasSrcExt(p.properties.Srcs, protoExt)
+	return hasSrcExt(p.properties.Srcs, ext)
 }
 
 func (p *Module) DepsMutator(ctx android.BottomUpMutatorContext) {
diff --git a/sdk/cc_sdk_test.go b/sdk/cc_sdk_test.go
index 84e4f28..b1eebe9 100644
--- a/sdk/cc_sdk_test.go
+++ b/sdk/cc_sdk_test.go
@@ -109,6 +109,7 @@
     name: "mysdk_sdkmember@current",
     sdk_member_name: "sdkmember",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     host_supported: true,
     installable: false,
     stl: "none",
@@ -131,6 +132,7 @@
     name: "sdkmember",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     host_supported: true,
     stl: "none",
     compile_multilib: "64",
@@ -353,6 +355,7 @@
     name: "mysdk_crtobj@current",
     sdk_member_name: "crtobj",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     stl: "none",
     compile_multilib: "both",
     sanitize: {
@@ -372,6 +375,7 @@
     name: "crtobj",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     stl: "none",
     compile_multilib: "both",
     sanitize: {
@@ -480,6 +484,7 @@
     name: "mysdk_mynativelib@current",
     sdk_member_name: "mynativelib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     installable: false,
     stl: "none",
     compile_multilib: "both",
@@ -511,6 +516,7 @@
     name: "mynativelib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     stl: "none",
     compile_multilib: "both",
     export_include_dirs: ["include/include"],
@@ -575,6 +581,7 @@
     name: "mymodule_exports_mynativebinary@current",
     sdk_member_name: "mynativebinary",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     installable: false,
     compile_multilib: "both",
     arch: {
@@ -591,6 +598,7 @@
     name: "mynativebinary",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     compile_multilib: "both",
     arch: {
         arm64: {
@@ -654,6 +662,7 @@
     name: "myexports_mynativebinary@current",
     sdk_member_name: "mynativebinary",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     installable: false,
@@ -687,6 +696,7 @@
     name: "mynativebinary",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     stl: "none",
@@ -802,6 +812,7 @@
     name: "myexports_mynativebinary@current",
     sdk_member_name: "mynativebinary",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     installable: false,
@@ -822,6 +833,7 @@
     name: "mynativebinary",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     stl: "none",
@@ -841,6 +853,7 @@
     name: "myexports_mynativelib@current",
     sdk_member_name: "mynativelib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     installable: false,
@@ -861,6 +874,7 @@
     name: "mynativelib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     stl: "none",
@@ -933,6 +947,7 @@
     name: "mymodule_exports_linker@current",
     sdk_member_name: "linker",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     installable: false,
@@ -959,6 +974,7 @@
     name: "linker",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     stl: "none",
@@ -1167,6 +1183,7 @@
     name: "mysdk_mynativelib@current",
     sdk_member_name: "mynativelib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     installable: false,
     stl: "none",
     compile_multilib: "both",
@@ -1188,6 +1205,7 @@
     name: "mynativelib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     stl: "none",
     compile_multilib: "both",
     shared_libs: [
@@ -1208,6 +1226,7 @@
     name: "mysdk_myothernativelib@current",
     sdk_member_name: "myothernativelib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     installable: false,
     stl: "none",
     compile_multilib: "both",
@@ -1226,6 +1245,7 @@
     name: "myothernativelib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     stl: "none",
     compile_multilib: "both",
     system_shared_libs: ["libm"],
@@ -1243,6 +1263,7 @@
     name: "mysdk_mysystemnativelib@current",
     sdk_member_name: "mysystemnativelib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     installable: false,
     stl: "none",
     compile_multilib: "both",
@@ -1260,6 +1281,7 @@
     name: "mysystemnativelib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     stl: "none",
     compile_multilib: "both",
     arch: {
@@ -1327,6 +1349,7 @@
     name: "mysdk_mynativelib@current",
     sdk_member_name: "mynativelib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     installable: false,
@@ -1355,6 +1378,7 @@
     name: "mynativelib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     sdk_version: "minimum",
@@ -1449,6 +1473,7 @@
     name: "mysdk_mynativelib@current",
     sdk_member_name: "mynativelib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     installable: false,
@@ -1482,6 +1507,7 @@
     name: "mynativelib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     stl: "none",
@@ -1572,6 +1598,7 @@
     name: "myexports_mynativelib@current",
     sdk_member_name: "mynativelib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     installable: false,
     stl: "none",
     compile_multilib: "both",
@@ -1592,6 +1619,7 @@
     name: "mynativelib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     stl: "none",
     compile_multilib: "both",
     export_include_dirs: ["include/include"],
@@ -1660,6 +1688,7 @@
     name: "myexports_mynativelib@current",
     sdk_member_name: "mynativelib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     installable: false,
@@ -1687,6 +1716,7 @@
     name: "mynativelib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     stl: "none",
@@ -1769,6 +1799,7 @@
     name: "myexports_mynativelib@current",
     sdk_member_name: "mynativelib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     installable: false,
     recovery_available: true,
     vendor_available: true,
@@ -1799,6 +1830,7 @@
     name: "mynativelib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     recovery_available: true,
     vendor_available: true,
     stl: "none",
@@ -1877,6 +1909,7 @@
     name: "myexports_mynativelib@current",
     sdk_member_name: "mynativelib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     installable: false,
@@ -1899,6 +1932,7 @@
     name: "mynativelib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     stl: "none",
@@ -1964,6 +1998,7 @@
     name: "mysdk_mynativeheaders@current",
     sdk_member_name: "mynativeheaders",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     stl: "none",
     compile_multilib: "both",
     export_include_dirs: ["include/include"],
@@ -1973,6 +2008,7 @@
     name: "mynativeheaders",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     stl: "none",
     compile_multilib: "both",
     export_include_dirs: ["include/include"],
@@ -2016,6 +2052,7 @@
     name: "mysdk_mynativeheaders@current",
     sdk_member_name: "mynativeheaders",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     stl: "none",
@@ -2038,6 +2075,7 @@
     name: "mynativeheaders",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     stl: "none",
@@ -2113,6 +2151,7 @@
     name: "mysdk_mynativeheaders@current",
     sdk_member_name: "mynativeheaders",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     host_supported: true,
     stl: "none",
     compile_multilib: "both",
@@ -2140,6 +2179,7 @@
     name: "mynativeheaders",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     host_supported: true,
     stl: "none",
     compile_multilib: "both",
@@ -2220,6 +2260,7 @@
     name: "mysdk_sslnil@current",
     sdk_member_name: "sslnil",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     installable: false,
     compile_multilib: "both",
     arch: {
@@ -2236,6 +2277,7 @@
     name: "sslnil",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     compile_multilib: "both",
     arch: {
         arm64: {
@@ -2251,6 +2293,7 @@
     name: "mysdk_sslempty@current",
     sdk_member_name: "sslempty",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     installable: false,
     compile_multilib: "both",
     system_shared_libs: [],
@@ -2268,6 +2311,7 @@
     name: "sslempty",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     compile_multilib: "both",
     system_shared_libs: [],
     arch: {
@@ -2284,6 +2328,7 @@
     name: "mysdk_sslnonempty@current",
     sdk_member_name: "sslnonempty",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     installable: false,
     compile_multilib: "both",
     system_shared_libs: ["mysdk_sslnil@current"],
@@ -2301,6 +2346,7 @@
     name: "sslnonempty",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     compile_multilib: "both",
     system_shared_libs: ["sslnil"],
     arch: {
@@ -2350,6 +2396,7 @@
     name: "mysdk_sslvariants@current",
     sdk_member_name: "sslvariants",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     host_supported: true,
     installable: false,
     compile_multilib: "both",
@@ -2381,6 +2428,7 @@
     name: "sslvariants",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     host_supported: true,
     compile_multilib: "both",
     target: {
@@ -2456,6 +2504,7 @@
     name: "mysdk_stubslib@current",
     sdk_member_name: "stubslib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     installable: false,
     compile_multilib: "both",
     stubs: {
@@ -2479,6 +2528,7 @@
     name: "stubslib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     compile_multilib: "both",
     stubs: {
         versions: [
@@ -2537,6 +2587,7 @@
     name: "mysdk_stubslib@current",
     sdk_member_name: "stubslib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     host_supported: true,
     installable: false,
     compile_multilib: "both",
@@ -2572,6 +2623,7 @@
     name: "stubslib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     host_supported: true,
     compile_multilib: "both",
     stubs: {
@@ -2645,6 +2697,7 @@
     name: "mysdk_mylib@current",
     sdk_member_name: "mylib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     host_supported: true,
     installable: false,
     unique_host_soname: true,
@@ -2674,6 +2727,7 @@
     name: "mylib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     host_supported: true,
     unique_host_soname: true,
     compile_multilib: "both",
@@ -2755,6 +2809,7 @@
     name: "mysdk_mynativelib@current",
     sdk_member_name: "mynativelib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     installable: false,
     compile_multilib: "both",
     export_include_dirs: ["include/include"],
@@ -2772,6 +2827,7 @@
     name: "mynativelib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     compile_multilib: "both",
     export_include_dirs: ["include/include"],
     arch: {
diff --git a/sdk/exports_test.go b/sdk/exports_test.go
index aa1200f..1c59244 100644
--- a/sdk/exports_test.go
+++ b/sdk/exports_test.go
@@ -50,6 +50,7 @@
     name: "myexports_myjavalib@current",
     sdk_member_name: "myjavalib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/myjavalib.jar"],
 }
 
@@ -57,6 +58,7 @@
     name: "myjavalib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/myjavalib.jar"],
 }
 
diff --git a/sdk/java_sdk_test.go b/sdk/java_sdk_test.go
index 731e528..ec8ebb3 100644
--- a/sdk/java_sdk_test.go
+++ b/sdk/java_sdk_test.go
@@ -122,6 +122,7 @@
     name: "mysdk_sdkmember@current",
     sdk_member_name: "sdkmember",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/sdkmember.jar"],
 }
 
@@ -129,6 +130,7 @@
     name: "sdkmember",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/sdkmember.jar"],
 }
 
@@ -247,6 +249,7 @@
     name: "mysdk_myjavalib@current",
     sdk_member_name: "myjavalib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/myjavalib.jar"],
 }
 
@@ -254,6 +257,7 @@
     name: "myjavalib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/myjavalib.jar"],
 }
 
@@ -302,6 +306,7 @@
     name: "mysdk_myjavalib@current",
     sdk_member_name: "myjavalib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     jars: ["java/myjavalib.jar"],
@@ -311,6 +316,7 @@
     name: "myjavalib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     jars: ["java/myjavalib.jar"],
@@ -357,6 +363,7 @@
     name: "mysdk_myjavalib@current",
     sdk_member_name: "myjavalib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     host_supported: true,
     target: {
         android: {
@@ -372,6 +379,7 @@
     name: "myjavalib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     host_supported: true,
     target: {
         android: {
@@ -426,6 +434,7 @@
     name: "myexports_myjavalib@current",
     sdk_member_name: "myjavalib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/myjavalib.jar"],
 }
 
@@ -433,6 +442,7 @@
     name: "myjavalib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/myjavalib.jar"],
 }
 
@@ -481,6 +491,7 @@
     name: "myexports_myjavalib@current",
     sdk_member_name: "myjavalib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     jars: ["java/myjavalib.jar"],
@@ -490,6 +501,7 @@
     name: "myjavalib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     jars: ["java/myjavalib.jar"],
@@ -535,6 +547,7 @@
     name: "myexports_myjavatests@current",
     sdk_member_name: "myjavatests",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/myjavatests.jar"],
     test_config: "java/myjavatests-AndroidTest.xml",
 }
@@ -543,6 +556,7 @@
     name: "myjavatests",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/myjavatests.jar"],
     test_config: "java/myjavatests-AndroidTest.xml",
 }
@@ -588,6 +602,7 @@
     name: "myexports_myjavatests@current",
     sdk_member_name: "myjavatests",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     jars: ["java/myjavatests.jar"],
@@ -598,6 +613,7 @@
     name: "myjavatests",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     jars: ["java/myjavatests.jar"],
@@ -655,6 +671,7 @@
     name: "mysdk_exported-system-module@current",
     sdk_member_name: "exported-system-module",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/exported-system-module.jar"],
 }
 
@@ -662,6 +679,7 @@
     name: "exported-system-module",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/exported-system-module.jar"],
 }
 
@@ -669,6 +687,7 @@
     name: "mysdk_system-module@current",
     sdk_member_name: "system-module",
     visibility: ["//visibility:private"],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/system-module.jar"],
 }
 
@@ -676,6 +695,7 @@
     name: "mysdk_system-module",
     prefer: false,
     visibility: ["//visibility:private"],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/system-module.jar"],
 }
 
@@ -747,6 +767,7 @@
     name: "mysdk_system-module@current",
     sdk_member_name: "system-module",
     visibility: ["//visibility:private"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     jars: ["java/system-module.jar"],
@@ -756,6 +777,7 @@
     name: "mysdk_system-module",
     prefer: false,
     visibility: ["//visibility:private"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     jars: ["java/system-module.jar"],
@@ -836,6 +858,7 @@
     name: "myexports_hostjavalib@current",
     sdk_member_name: "hostjavalib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     jars: ["java/hostjavalib.jar"],
@@ -845,6 +868,7 @@
     name: "hostjavalib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     device_supported: false,
     host_supported: true,
     jars: ["java/hostjavalib.jar"],
@@ -854,6 +878,7 @@
     name: "myexports_androidjavalib@current",
     sdk_member_name: "androidjavalib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/androidjavalib.jar"],
 }
 
@@ -861,6 +886,7 @@
     name: "androidjavalib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/androidjavalib.jar"],
 }
 
@@ -868,6 +894,7 @@
     name: "myexports_myjavalib@current",
     sdk_member_name: "myjavalib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     host_supported: true,
     target: {
         android: {
@@ -883,6 +910,7 @@
     name: "myjavalib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     host_supported: true,
     target: {
         android: {
@@ -1045,6 +1073,7 @@
     name: "mysdk_myjavalib@current",
     sdk_member_name: "myjavalib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     shared_library: true,
     public: {
         jars: ["sdk_library/public/myjavalib-stubs.jar"],
@@ -1059,6 +1088,7 @@
     name: "myjavalib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     shared_library: true,
     public: {
         jars: ["sdk_library/public/myjavalib-stubs.jar"],
@@ -1112,6 +1142,7 @@
     name: "mysdk_myjavalib@current",
     sdk_member_name: "myjavalib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     shared_library: true,
     public: {
         jars: ["sdk_library/public/myjavalib-stubs.jar"],
@@ -1126,6 +1157,7 @@
     name: "myjavalib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     shared_library: true,
     public: {
         jars: ["sdk_library/public/myjavalib-stubs.jar"],
@@ -1547,6 +1579,7 @@
     name: "mysdk_myjavalib@current",
     sdk_member_name: "myjavalib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     shared_library: true,
     doctag_files: ["doctags/docs/known_doctags"],
     public: {
@@ -1562,6 +1595,7 @@
     name: "myjavalib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     shared_library: true,
     doctag_files: ["doctags/docs/known_doctags"],
     public: {
diff --git a/sdk/sdk_test.go b/sdk/sdk_test.go
index 2e6c62a..c4dc41b 100644
--- a/sdk/sdk_test.go
+++ b/sdk/sdk_test.go
@@ -181,6 +181,7 @@
         "//package",
         "//prebuilts/mysdk",
     ],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/myjavalib.jar"],
 }
 
@@ -192,6 +193,7 @@
         "//package",
         "//prebuilts/mysdk",
     ],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/myjavalib.jar"],
 }
 
@@ -199,6 +201,7 @@
     name: "mysdk_mypublicjavalib@current",
     sdk_member_name: "mypublicjavalib",
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/mypublicjavalib.jar"],
 }
 
@@ -206,6 +209,7 @@
     name: "mypublicjavalib",
     prefer: false,
     visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/mypublicjavalib.jar"],
 }
 
@@ -217,6 +221,7 @@
         "//package",
         "//prebuilts/mysdk",
     ],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/mydefaultedjavalib.jar"],
 }
 
@@ -228,6 +233,7 @@
         "//package",
         "//prebuilts/mysdk",
     ],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/mydefaultedjavalib.jar"],
 }
 
@@ -238,6 +244,7 @@
         "//package",
         "//prebuilts/mysdk",
     ],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/myprivatejavalib.jar"],
 }
 
@@ -248,6 +255,7 @@
         "//package",
         "//prebuilts/mysdk",
     ],
+    apex_available: ["//apex_available:platform"],
     jars: ["java/myprivatejavalib.jar"],
 }
 
diff --git a/sdk/update.go b/sdk/update.go
index 7bf5dea..ba63542 100644
--- a/sdk/update.go
+++ b/sdk/update.go
@@ -735,6 +735,24 @@
 		}
 	}
 
+	// Where available copy apex_available properties from the member.
+	if apexAware, ok := variant.(interface{ ApexAvailable() []string }); ok {
+		apexAvailable := apexAware.ApexAvailable()
+		if len(apexAvailable) == 0 {
+			// //apex_available:platform is the default.
+			apexAvailable = []string{android.AvailableToPlatform}
+		}
+
+		// Add in any baseline apex available settings.
+		apexAvailable = append(apexAvailable, apex.BaselineApexAvailable(member.Name())...)
+
+		// Remove duplicates and sort.
+		apexAvailable = android.FirstUniqueStrings(apexAvailable)
+		sort.Strings(apexAvailable)
+
+		m.AddProperty("apex_available", apexAvailable)
+	}
+
 	deviceSupported := false
 	hostSupported := false
 
@@ -749,22 +767,6 @@
 
 	addHostDeviceSupportedProperties(deviceSupported, hostSupported, m)
 
-	// Where available copy apex_available properties from the member.
-	if apexAware, ok := variant.(interface{ ApexAvailable() []string }); ok {
-		apexAvailable := apexAware.ApexAvailable()
-
-		// Add in any baseline apex available settings.
-		apexAvailable = append(apexAvailable, apex.BaselineApexAvailable(member.Name())...)
-
-		if len(apexAvailable) > 0 {
-			// Remove duplicates and sort.
-			apexAvailable = android.FirstUniqueStrings(apexAvailable)
-			sort.Strings(apexAvailable)
-
-			m.AddProperty("apex_available", apexAvailable)
-		}
-	}
-
 	// Disable installation in the versioned module of those modules that are ever installable.
 	if installable, ok := variant.(interface{ EverInstallable() bool }); ok {
 		if installable.EverInstallable() {
diff --git a/ui/build/bazel.go b/ui/build/bazel.go
index 4b03bc1..7cc7caf 100644
--- a/ui/build/bazel.go
+++ b/ui/build/bazel.go
@@ -24,6 +24,8 @@
 	"android/soong/ui/metrics"
 )
 
+// Main entry point to construct the Bazel build command line, environment variables
+// and post-processing steps (e.g. converge output directories)
 func runBazel(ctx Context, config Config) {
 	ctx.BeginTrace(metrics.RunBazel, "bazel")
 	defer ctx.EndTrace()
@@ -67,6 +69,10 @@
 		"//:"+config.TargetProduct()+"-"+config.TargetBuildVariant(),
 	)
 
+	if pathEnvValue, ok := config.environ.Get("PATH"); ok {
+		cmd.Environment.Set("PATH", pathEnvValue)
+		cmd.Args = append(cmd.Args, "--action_env=PATH="+pathEnvValue)
+	}
 	cmd.Environment.Set("DIST_DIR", config.DistDir())
 	cmd.Environment.Set("SHELL", "/bin/bash")