Merge "Add context for invalid extensions for cc compile"
diff --git a/android/androidmk.go b/android/androidmk.go
index 6ab4a24..42c5d00 100644
--- a/android/androidmk.go
+++ b/android/androidmk.go
@@ -499,7 +499,9 @@
 			}
 		}
 
-		a.AddStrings("LOCAL_INIT_RC", amod.commonProperties.Init_rc...)
+		if !amod.InRamdisk() && !amod.InVendorRamdisk() {
+			a.AddStrings("LOCAL_INIT_RC", amod.commonProperties.Init_rc...)
+		}
 		a.AddStrings("LOCAL_VINTF_FRAGMENTS", amod.commonProperties.Vintf_fragments...)
 		a.SetBoolIfTrue("LOCAL_PROPRIETARY_MODULE", Bool(amod.commonProperties.Proprietary))
 		if Bool(amod.commonProperties.Vendor) || Bool(amod.commonProperties.Soc_specific) {
diff --git a/apex/apex.go b/apex/apex.go
index f127757..7ab7454 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -353,6 +353,9 @@
 	lintReports android.Paths
 
 	prebuiltFileToDelete string
+
+	// Path of API coverage generate file
+	coverageOutputPath android.ModuleOutPath
 }
 
 // apexFileClass represents a type of file that can be included in APEX.
@@ -1663,7 +1666,7 @@
 							// system libraries.
 							if !am.DirectlyInAnyApex() {
 								// we need a module name for Make
-								name := cc.ImplementationModuleName(ctx)
+								name := cc.ImplementationModuleNameForMake(ctx)
 
 								if !proptools.Bool(a.properties.Use_vendor) {
 									// we don't use subName(.vendor) for a "use_vendor: true" apex
@@ -2013,7 +2016,9 @@
 			// The dynamic linker and crash_dump tool in the runtime APEX is the only
 			// exception to this rule. It can't make the static dependencies dynamic
 			// because it can't do the dynamic linking for itself.
-			if apexName == "com.android.runtime" && (fromName == "linker" || fromName == "crash_dump") {
+			// Same rule should be applied to linkerconfig, because it should be executed
+			// only with static linked libraries before linker is available with ld.config.txt
+			if apexName == "com.android.runtime" && (fromName == "linker" || fromName == "crash_dump" || fromName == "linkerconfig") {
 				return false
 			}
 
diff --git a/apex/apex_test.go b/apex/apex_test.go
index cc05fd4..0b67ef5 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -6186,6 +6186,57 @@
 	`)
 }
 
+func TestPreferredPrebuiltSharedLibDep(t *testing.T) {
+	ctx, config := testApex(t, `
+		apex {
+			name: "myapex",
+			key: "myapex.key",
+			native_shared_libs: ["mylib"],
+		}
+
+		apex_key {
+			name: "myapex.key",
+			public_key: "testkey.avbpubkey",
+			private_key: "testkey.pem",
+		}
+
+		cc_library {
+			name: "mylib",
+			srcs: ["mylib.cpp"],
+			apex_available: ["myapex"],
+			shared_libs: ["otherlib"],
+			system_shared_libs: [],
+		}
+
+		cc_library {
+			name: "otherlib",
+			srcs: ["mylib.cpp"],
+			stubs: {
+				versions: ["current"],
+			},
+		}
+
+		cc_prebuilt_library_shared {
+			name: "otherlib",
+			prefer: true,
+			srcs: ["prebuilt.so"],
+			stubs: {
+				versions: ["current"],
+			},
+		}
+	`)
+
+	ab := ctx.ModuleForTests("myapex", "android_common_myapex_image").Module().(*apexBundle)
+	data := android.AndroidMkDataForTest(t, config, "", ab)
+	var builder strings.Builder
+	data.Custom(&builder, ab.BaseModuleName(), "TARGET_", "", data)
+	androidMk := builder.String()
+
+	// The make level dependency needs to be on otherlib - prebuilt_otherlib isn't
+	// a thing there.
+	ensureContains(t, androidMk, "LOCAL_REQUIRED_MODULES += otherlib\n")
+}
+
 func TestMain(m *testing.M) {
 	run := func() int {
 		setUp()
diff --git a/apex/builder.go b/apex/builder.go
index dc8e5e0..66eaff1 100644
--- a/apex/builder.go
+++ b/apex/builder.go
@@ -37,6 +37,7 @@
 
 func init() {
 	pctx.Import("android/soong/android")
+	pctx.Import("android/soong/cc/config")
 	pctx.Import("android/soong/java")
 	pctx.HostBinToolVariable("apexer", "apexer")
 	// ART minimal builds (using the master-art manifest) do not have the "frameworks/base"
@@ -65,6 +66,7 @@
 	pctx.HostBinToolVariable("extract_apks", "extract_apks")
 	pctx.HostBinToolVariable("make_f2fs", "make_f2fs")
 	pctx.HostBinToolVariable("sload_f2fs", "sload_f2fs")
+	pctx.SourcePathVariable("genNdkUsedbyApexPath", "build/soong/scripts/gen_ndk_usedby_apex.sh")
 }
 
 var (
@@ -176,6 +178,12 @@
 		Description: "Diff ${image_content_file} and ${allowed_files_file}",
 	}, "image_content_file", "allowed_files_file", "apex_module_name")
 
+	generateAPIsUsedbyApexRule = pctx.StaticRule("generateAPIsUsedbyApexRule", blueprint.RuleParams{
+		Command:     "$genNdkUsedbyApexPath ${image_dir} ${readelf} ${out}",
+		CommandDeps: []string{"${genNdkUsedbyApexPath}"},
+		Description: "Generate symbol list used by Apex",
+	}, "image_dir", "readelf")
+
 	// Don't add more rules here. Consider using android.NewRuleBuilder instead.
 )
 
@@ -675,6 +683,22 @@
 			Description: "apex proto convert",
 		})
 
+		implicitInputs = append(implicitInputs, unsignedOutputFile)
+
+		// Run coverage analysis
+		apisUsedbyOutputFile := android.PathForModuleOut(ctx, a.Name()+".txt")
+		ctx.Build(pctx, android.BuildParams{
+			Rule:        generateAPIsUsedbyApexRule,
+			Implicits:   implicitInputs,
+			Description: "coverage",
+			Output:      apisUsedbyOutputFile,
+			Args: map[string]string{
+				"image_dir": imageDir.String(),
+				"readelf":   "${config.ClangBin}/llvm-readelf",
+			},
+		})
+		a.coverageOutputPath = apisUsedbyOutputFile
+
 		bundleConfig := a.buildBundleConfig(ctx)
 
 		var abis []string
diff --git a/cc/cc.go b/cc/cc.go
index f922ea5..b1c1264 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -1099,6 +1099,19 @@
 	return name
 }
 
+// Similar to ImplementationModuleName, but uses the Make variant of the module
+// name as base name, for use in AndroidMk output. E.g. for a prebuilt module
+// where the Soong name is prebuilt_foo, this returns foo (which works in Make
+// under the premise that the prebuilt module overrides its source counterpart
+// if it is exposed to Make).
+func (c *Module) ImplementationModuleNameForMake(ctx android.BaseModuleContext) string {
+	name := c.BaseModuleName()
+	if versioned, ok := c.linker.(versionedInterface); ok {
+		name = versioned.implementationModuleName(name)
+	}
+	return name
+}
+
 func (c *Module) bootstrap() bool {
 	return Bool(c.Properties.Bootstrap)
 }
@@ -1128,7 +1141,7 @@
 
 func isBionic(name string) bool {
 	switch name {
-	case "libc", "libm", "libdl", "libdl_android", "linker":
+	case "libc", "libm", "libdl", "libdl_android", "linker", "linkerconfig":
 		return true
 	}
 	return false
diff --git a/java/java.go b/java/java.go
index 95a4e88..3d121cc 100644
--- a/java/java.go
+++ b/java/java.go
@@ -1446,6 +1446,9 @@
 		kotlincFlags := j.properties.Kotlincflags
 		CheckKotlincFlags(ctx, kotlincFlags)
 
+		// Dogfood the JVM_IR backend.
+		kotlincFlags = append(kotlincFlags, "-Xuse-ir")
+
 		// If there are kotlin files, compile them first but pass all the kotlin and java files
 		// kotlinc will use the java files to resolve types referenced by the kotlin files, but
 		// won't emit any classes for them.
diff --git a/linkerconfig/proto/Android.bp b/linkerconfig/proto/Android.bp
index c04887e..4d97128 100644
--- a/linkerconfig/proto/Android.bp
+++ b/linkerconfig/proto/Android.bp
@@ -7,6 +7,10 @@
         type: "lite",
     },
     srcs: ["linker_config.proto"],
+    apex_available: [
+        "//apex_available:platform",
+        "//apex_available:anyapex",
+    ],
 }
 
 python_library_host {
diff --git a/python/binary.go b/python/binary.go
index 1d2400e..416a7ee 100644
--- a/python/binary.go
+++ b/python/binary.go
@@ -81,7 +81,7 @@
 func PythonBinaryHostFactory() android.Module {
 	module, _ := NewBinary(android.HostSupported)
 
-	return module.Init()
+	return module.init()
 }
 
 func (binary *binaryDecorator) autorun() bool {
diff --git a/python/library.go b/python/library.go
index 0c8d613..b724d2b 100644
--- a/python/library.go
+++ b/python/library.go
@@ -28,11 +28,11 @@
 func PythonLibraryHostFactory() android.Module {
 	module := newModule(android.HostSupported, android.MultilibFirst)
 
-	return module.Init()
+	return module.init()
 }
 
 func PythonLibraryFactory() android.Module {
 	module := newModule(android.HostAndDeviceSupported, android.MultilibBoth)
 
-	return module.Init()
+	return module.init()
 }
diff --git a/python/python.go b/python/python.go
index 7e376c6..b3e3d13 100644
--- a/python/python.go
+++ b/python/python.go
@@ -20,7 +20,6 @@
 	"fmt"
 	"path/filepath"
 	"regexp"
-	"sort"
 	"strings"
 
 	"github.com/google/blueprint"
@@ -33,33 +32,34 @@
 	android.PreDepsMutators(RegisterPythonPreDepsMutators)
 }
 
+// Exported to support other packages using Python modules in tests.
 func RegisterPythonPreDepsMutators(ctx android.RegisterMutatorsContext) {
 	ctx.BottomUp("python_version", versionSplitMutator()).Parallel()
 }
 
-// the version properties that apply to python libraries and binaries.
+// the version-specific properties that apply to python modules.
 type VersionProperties struct {
-	// true, if the module is required to be built with this version.
+	// whether the module is required to be built with this version.
+	// Defaults to true for Python 3, and false otherwise.
 	Enabled *bool `android:"arch_variant"`
 
-	// non-empty list of .py files under this strict Python version.
-	// srcs may reference the outputs of other modules that produce source files like genrule
-	// or filegroup using the syntax ":module".
+	// list of source files specific to this Python version.
+	// Using the syntax ":module", srcs may reference the outputs of other modules that produce source files,
+	// e.g. genrule or filegroup.
 	Srcs []string `android:"path,arch_variant"`
 
-	// list of source files that should not be used to build the Python module.
-	// This is most useful in the arch/multilib variants to remove non-common files
+	// list of source files that should not be used to build the Python module for this version.
+	// This is most useful to remove files that are not common to all Python versions.
 	Exclude_srcs []string `android:"path,arch_variant"`
 
-	// list of the Python libraries under this Python version.
+	// list of the Python libraries used only for this Python version.
 	Libs []string `android:"arch_variant"`
 
-	// true, if the binary is required to be built with embedded launcher.
-	// TODO(nanzhang): Remove this flag when embedded Python3 is supported later.
-	Embedded_launcher *bool `android:"arch_variant"`
+	// whether the binary is required to be built with embedded launcher for this version, defaults to false.
+	Embedded_launcher *bool `android:"arch_variant"` // TODO(b/174041232): Remove this property
 }
 
-// properties that apply to python libraries and binaries.
+// properties that apply to all python modules
 type BaseProperties struct {
 	// the package path prefix within the output artifact at which to place the source/data
 	// files of the current module.
@@ -93,10 +93,12 @@
 	Libs []string `android:"arch_variant"`
 
 	Version struct {
-		// all the "srcs" or Python dependencies that are to be used only for Python2.
+		// Python2-specific properties, including whether Python2 is supported for this module
+		// and version-specific sources, exclusions and dependencies.
 		Py2 VersionProperties `android:"arch_variant"`
 
-		// all the "srcs" or Python dependencies that are to be used only for Python3.
+		// Python3-specific properties, including whether Python3 is supported for this module
+		// and version-specific sources, exclusions and dependencies.
 		Py3 VersionProperties `android:"arch_variant"`
 	} `android:"arch_variant"`
 
@@ -105,14 +107,16 @@
 	// runtime.
 	Actual_version string `blueprint:"mutated"`
 
-	// true, if the module is required to be built with actual_version.
+	// whether the module is required to be built with actual_version.
+	// this is set by the python version mutator based on version-specific properties
 	Enabled *bool `blueprint:"mutated"`
 
-	// true, if the binary is required to be built with embedded launcher.
-	// TODO(nanzhang): Remove this flag when embedded Python3 is supported later.
+	// whether the binary is required to be built with embedded launcher for this actual_version.
+	// this is set by the python version mutator based on version-specific properties
 	Embedded_launcher *bool `blueprint:"mutated"`
 }
 
+// Used to store files of current module after expanding dependencies
 type pathMapping struct {
 	dest string
 	src  android.Path
@@ -129,11 +133,14 @@
 	hod      android.HostOrDeviceSupported
 	multilib android.Multilib
 
-	// the bootstrapper is used to bootstrap .par executable.
-	// bootstrapper might be nil (Python library module).
+	// interface used to bootstrap .par executable when embedded_launcher is true
+	// this should be set by Python modules which are runnable, e.g. binaries and tests
+	// bootstrapper might be nil (e.g. Python library module).
 	bootstrapper bootstrapper
 
-	// the installer might be nil.
+	// interface that implements functions required for installation
+	// this should be set by Python modules which are runnable, e.g. binaries and tests
+	// installer might be nil (e.g. Python library module).
 	installer installer
 
 	// the Python files of current module after expanding source dependencies.
@@ -153,9 +160,11 @@
 	// (.intermediate) module output path as installation source.
 	installSource android.OptionalPath
 
+	// Map to ensure sub-part of the AndroidMk for this module is only added once
 	subAndroidMkOnce map[subAndroidMkProvider]bool
 }
 
+// newModule generates new Python base module
 func newModule(hod android.HostOrDeviceSupported, multilib android.Multilib) *Module {
 	return &Module{
 		hod:      hod,
@@ -163,6 +172,7 @@
 	}
 }
 
+// bootstrapper interface should be implemented for runnable modules, e.g. binary and test
 type bootstrapper interface {
 	bootstrapperProps() []interface{}
 	bootstrap(ctx android.ModuleContext, ActualVersion string, embeddedLauncher bool,
@@ -172,36 +182,45 @@
 	autorun() bool
 }
 
+// installer interface should be implemented for installable modules, e.g. binary and test
 type installer interface {
 	install(ctx android.ModuleContext, path android.Path)
 	setAndroidMkSharedLibs(sharedLibs []string)
 }
 
-type PythonDependency interface {
-	GetSrcsPathMappings() []pathMapping
-	GetDataPathMappings() []pathMapping
-	GetSrcsZip() android.Path
+// interface implemented by Python modules to provide source and data mappings and zip to python
+// modules that depend on it
+type pythonDependency interface {
+	getSrcsPathMappings() []pathMapping
+	getDataPathMappings() []pathMapping
+	getSrcsZip() android.Path
 }
 
-func (p *Module) GetSrcsPathMappings() []pathMapping {
+// getSrcsPathMappings gets this module's path mapping of src source path : runfiles destination
+func (p *Module) getSrcsPathMappings() []pathMapping {
 	return p.srcsPathMappings
 }
 
-func (p *Module) GetDataPathMappings() []pathMapping {
+// getSrcsPathMappings gets this module's path mapping of data source path : runfiles destination
+func (p *Module) getDataPathMappings() []pathMapping {
 	return p.dataPathMappings
 }
 
-func (p *Module) GetSrcsZip() android.Path {
+// getSrcsZip returns the filepath where the current module's source/data files are zipped.
+func (p *Module) getSrcsZip() android.Path {
 	return p.srcsZip
 }
 
-var _ PythonDependency = (*Module)(nil)
+var _ pythonDependency = (*Module)(nil)
 
 var _ android.AndroidMkEntriesProvider = (*Module)(nil)
 
-func (p *Module) Init() android.Module {
-
+func (p *Module) init(additionalProps ...interface{}) android.Module {
 	p.AddProperties(&p.properties, &p.protoProperties)
+
+	// Add additional properties for bootstrapping/installation
+	// This is currently tied to the bootstrapper interface;
+	// however, these are a combination of properties for the installation and bootstrapping of a module
 	if p.bootstrapper != nil {
 		p.AddProperties(p.bootstrapper.bootstrapperProps()...)
 	}
@@ -212,13 +231,19 @@
 	return p
 }
 
+// Python-specific tag to transfer information on the purpose of a dependency.
+// This is used when adding a dependency on a module, which can later be accessed when visiting
+// dependencies.
 type dependencyTag struct {
 	blueprint.BaseDependencyTag
 	name string
 }
 
+// Python-specific tag that indicates that installed files of this module should depend on installed
+// files of the dependency
 type installDependencyTag struct {
 	blueprint.BaseDependencyTag
+	// embedding this struct provides the installation dependency requirement
 	android.InstallAlwaysNeededDependencyTag
 	name string
 }
@@ -228,7 +253,7 @@
 	javaDataTag          = dependencyTag{name: "javaData"}
 	launcherTag          = dependencyTag{name: "launcher"}
 	launcherSharedLibTag = installDependencyTag{name: "launcherSharedLib"}
-	pyIdentifierRegexp   = regexp.MustCompile(`^[a-zA-Z_][a-zA-Z0-9_-]*$`)
+	pathComponentRegexp  = regexp.MustCompile(`^[a-zA-Z_][a-zA-Z0-9_-]*$`)
 	pyExt                = ".py"
 	protoExt             = ".proto"
 	pyVersion2           = "PY2"
@@ -237,35 +262,37 @@
 	mainFileName         = "__main__.py"
 	entryPointFile       = "entry_point.txt"
 	parFileExt           = ".zip"
-	internal             = "internal"
+	internalPath         = "internal"
 )
 
-// create version variants for modules.
+// versionSplitMutator creates version variants for modules and appends the version-specific
+// properties for a given variant to the properties in the variant module
 func versionSplitMutator() func(android.BottomUpMutatorContext) {
 	return func(mctx android.BottomUpMutatorContext) {
 		if base, ok := mctx.Module().(*Module); ok {
 			versionNames := []string{}
+			// collect version specific properties, so that we can merge version-specific properties
+			// into the module's overall properties
 			versionProps := []VersionProperties{}
 			// PY3 is first so that we alias the PY3 variant rather than PY2 if both
 			// are available
-			if !(base.properties.Version.Py3.Enabled != nil &&
-				*(base.properties.Version.Py3.Enabled) == false) {
+			if proptools.BoolDefault(base.properties.Version.Py3.Enabled, true) {
 				versionNames = append(versionNames, pyVersion3)
 				versionProps = append(versionProps, base.properties.Version.Py3)
 			}
-			if base.properties.Version.Py2.Enabled != nil &&
-				*(base.properties.Version.Py2.Enabled) == true {
+			if proptools.BoolDefault(base.properties.Version.Py2.Enabled, false) {
 				versionNames = append(versionNames, pyVersion2)
 				versionProps = append(versionProps, base.properties.Version.Py2)
 			}
 			modules := mctx.CreateLocalVariations(versionNames...)
+			// Alias module to the first variant
 			if len(versionNames) > 0 {
 				mctx.AliasVariation(versionNames[0])
 			}
 			for i, v := range versionNames {
 				// set the actual version for Python module.
 				modules[i].(*Module).properties.Actual_version = v
-				// append versioned properties for the Python module
+				// append versioned properties for the Python module to the overall properties
 				err := proptools.AppendMatchingProperties([]interface{}{&modules[i].(*Module).properties}, &versionProps[i], nil)
 				if err != nil {
 					panic(err)
@@ -275,14 +302,19 @@
 	}
 }
 
+// HostToolPath returns a path if appropriate such that this module can be used as a host tool,
+// fulfilling HostToolProvider interface.
 func (p *Module) HostToolPath() android.OptionalPath {
 	if p.installer == nil {
 		// python_library is just meta module, and doesn't have any installer.
 		return android.OptionalPath{}
 	}
+	// TODO: This should only be set when building host binaries -- tests built for device would be
+	// setting this incorrectly.
 	return android.OptionalPathForPath(p.installer.(*binaryDecorator).path)
 }
 
+// OutputFiles returns output files based on given tag, returns an error if tag is unsupported.
 func (p *Module) OutputFiles(tag string) (android.Paths, error) {
 	switch tag {
 	case "":
@@ -296,12 +328,12 @@
 }
 
 func (p *Module) isEmbeddedLauncherEnabled() bool {
-	return Bool(p.properties.Embedded_launcher)
+	return p.installer != nil && Bool(p.properties.Embedded_launcher)
 }
 
-func hasSrcExt(srcs []string, ext string) bool {
-	for _, src := range srcs {
-		if filepath.Ext(src) == ext {
+func anyHasExt(paths []string, ext string) bool {
+	for _, p := range paths {
+		if filepath.Ext(p) == ext {
 			return true
 		}
 	}
@@ -309,10 +341,14 @@
 	return false
 }
 
-func (p *Module) hasSrcExt(ctx android.BottomUpMutatorContext, ext string) bool {
-	return hasSrcExt(p.properties.Srcs, ext)
+func (p *Module) anySrcHasExt(ctx android.BottomUpMutatorContext, ext string) bool {
+	return anyHasExt(p.properties.Srcs, ext)
 }
 
+// DepsMutator mutates dependencies for this module:
+//  * handles proto dependencies,
+//  * if required, specifies launcher and adds launcher dependencies,
+//  * applies python version mutations to Python dependencies
 func (p *Module) DepsMutator(ctx android.BottomUpMutatorContext) {
 	android.ProtoDeps(ctx, &p.protoProperties)
 
@@ -320,66 +356,61 @@
 		{"python_version", p.properties.Actual_version},
 	}
 
-	if p.hasSrcExt(ctx, protoExt) && p.Name() != "libprotobuf-python" {
+	// If sources contain a proto file, add dependency on libprotobuf-python
+	if p.anySrcHasExt(ctx, protoExt) && p.Name() != "libprotobuf-python" {
 		ctx.AddVariationDependencies(versionVariation, pythonLibTag, "libprotobuf-python")
 	}
+
+	// Add python library dependencies for this python version variation
 	ctx.AddVariationDependencies(versionVariation, pythonLibTag, android.LastUniqueStrings(p.properties.Libs)...)
 
-	switch p.properties.Actual_version {
-	case pyVersion2:
+	// If this module will be installed and has an embedded launcher, we need to add dependencies for:
+	//   * standard library
+	//   * launcher
+	//   * shared dependencies of the launcher
+	if p.installer != nil && p.isEmbeddedLauncherEnabled() {
+		var stdLib string
+		var launcherModule string
+		// Add launcher shared lib dependencies. Ideally, these should be
+		// derived from the `shared_libs` property of the launcher. However, we
+		// cannot read the property at this stage and it will be too late to add
+		// dependencies later.
+		launcherSharedLibDeps := []string{
+			"libsqlite",
+		}
+		// Add launcher-specific dependencies for bionic
+		if ctx.Target().Os.Bionic() {
+			launcherSharedLibDeps = append(launcherSharedLibDeps, "libc", "libdl", "libm")
+		}
 
-		if p.bootstrapper != nil && p.isEmbeddedLauncherEnabled() {
-			ctx.AddVariationDependencies(versionVariation, pythonLibTag, "py2-stdlib")
+		switch p.properties.Actual_version {
+		case pyVersion2:
+			stdLib = "py2-stdlib"
 
-			launcherModule := "py2-launcher"
+			launcherModule = "py2-launcher"
 			if p.bootstrapper.autorun() {
 				launcherModule = "py2-launcher-autorun"
 			}
-			ctx.AddFarVariationDependencies(ctx.Target().Variations(), launcherTag, launcherModule)
+			launcherSharedLibDeps = append(launcherSharedLibDeps, "libc++")
 
-			// Add py2-launcher shared lib dependencies. Ideally, these should be
-			// derived from the `shared_libs` property of "py2-launcher". However, we
-			// cannot read the property at this stage and it will be too late to add
-			// dependencies later.
-			ctx.AddFarVariationDependencies(ctx.Target().Variations(), launcherSharedLibTag, "libsqlite")
-			ctx.AddFarVariationDependencies(ctx.Target().Variations(), launcherSharedLibTag, "libc++")
+		case pyVersion3:
+			stdLib = "py3-stdlib"
 
-			if ctx.Target().Os.Bionic() {
-				ctx.AddFarVariationDependencies(ctx.Target().Variations(), launcherSharedLibTag,
-					"libc", "libdl", "libm")
-			}
-		}
-
-	case pyVersion3:
-
-		if p.bootstrapper != nil && p.isEmbeddedLauncherEnabled() {
-			ctx.AddVariationDependencies(versionVariation, pythonLibTag, "py3-stdlib")
-
-			launcherModule := "py3-launcher"
+			launcherModule = "py3-launcher"
 			if p.bootstrapper.autorun() {
 				launcherModule = "py3-launcher-autorun"
 			}
-			ctx.AddFarVariationDependencies(ctx.Target().Variations(), launcherTag, launcherModule)
-
-			// Add py3-launcher shared lib dependencies. Ideally, these should be
-			// derived from the `shared_libs` property of "py3-launcher". However, we
-			// cannot read the property at this stage and it will be too late to add
-			// dependencies later.
-			ctx.AddFarVariationDependencies(ctx.Target().Variations(), launcherSharedLibTag, "libsqlite")
 
 			if ctx.Device() {
-				ctx.AddFarVariationDependencies(ctx.Target().Variations(), launcherSharedLibTag,
-					"liblog")
+				launcherSharedLibDeps = append(launcherSharedLibDeps, "liblog")
 			}
-
-			if ctx.Target().Os.Bionic() {
-				ctx.AddFarVariationDependencies(ctx.Target().Variations(), launcherSharedLibTag,
-					"libc", "libdl", "libm")
-			}
+		default:
+			panic(fmt.Errorf("unknown Python Actual_version: %q for module: %q.",
+				p.properties.Actual_version, ctx.ModuleName()))
 		}
-	default:
-		panic(fmt.Errorf("unknown Python Actual_version: %q for module: %q.",
-			p.properties.Actual_version, ctx.ModuleName()))
+		ctx.AddVariationDependencies(versionVariation, pythonLibTag, stdLib)
+		ctx.AddFarVariationDependencies(ctx.Target().Variations(), launcherTag, launcherModule)
+		ctx.AddFarVariationDependencies(ctx.Target().Variations(), launcherSharedLibTag, launcherSharedLibDeps...)
 	}
 
 	// Emulate the data property for java_data but with the arch variation overridden to "common"
@@ -389,19 +420,25 @@
 }
 
 func (p *Module) GenerateAndroidBuildActions(ctx android.ModuleContext) {
-	p.GeneratePythonBuildActions(ctx)
+	p.generatePythonBuildActions(ctx)
 
-	// Only Python binaries and test has non-empty bootstrapper.
+	// Only Python binary and test modules have non-empty bootstrapper.
 	if p.bootstrapper != nil {
-		p.walkTransitiveDeps(ctx)
-		embeddedLauncher := false
-		embeddedLauncher = p.isEmbeddedLauncherEnabled()
+		// if the module is being installed, we need to collect all transitive dependencies to embed in
+		// the final par
+		p.collectPathsFromTransitiveDeps(ctx)
+		// bootstrap the module, including resolving main file, getting launcher path, and
+		// registering actions to build the par file
+		// bootstrap returns the binary output path
 		p.installSource = p.bootstrapper.bootstrap(ctx, p.properties.Actual_version,
-			embeddedLauncher, p.srcsPathMappings, p.srcsZip, p.depsSrcsZips)
+			p.isEmbeddedLauncherEnabled(), p.srcsPathMappings, p.srcsZip, p.depsSrcsZips)
 	}
 
+	// Only Python binary and test modules have non-empty installer.
 	if p.installer != nil {
 		var sharedLibs []string
+		// if embedded launcher is enabled, we need to collect the shared library depenendencies of the
+		// launcher
 		ctx.VisitDirectDeps(func(dep android.Module) {
 			if ctx.OtherModuleDependencyTag(dep) == launcherSharedLibTag {
 				sharedLibs = append(sharedLibs, ctx.OtherModuleName(dep))
@@ -409,18 +446,16 @@
 		})
 		p.installer.setAndroidMkSharedLibs(sharedLibs)
 
+		// Install the par file from installSource
 		if p.installSource.Valid() {
 			p.installer.install(ctx, p.installSource.Path())
 		}
 	}
-
 }
 
-func (p *Module) GeneratePythonBuildActions(ctx android.ModuleContext) {
-	// expand python files from "srcs" property.
-	srcs := p.properties.Srcs
-	exclude_srcs := p.properties.Exclude_srcs
-	expandedSrcs := android.PathsForModuleSrcExcludes(ctx, srcs, exclude_srcs)
+// generatePythonBuildActions performs build actions common to all Python modules
+func (p *Module) generatePythonBuildActions(ctx android.ModuleContext) {
+	expandedSrcs := android.PathsForModuleSrcExcludes(ctx, p.properties.Srcs, p.properties.Exclude_srcs)
 	requiresSrcs := true
 	if p.bootstrapper != nil && !p.bootstrapper.autorun() {
 		requiresSrcs = false
@@ -437,9 +472,10 @@
 		expandedData = append(expandedData, android.OutputFilesForModule(ctx, javaData, "")...)
 	}
 
-	// sanitize pkg_path.
+	// Validate pkg_path property
 	pkgPath := String(p.properties.Pkg_path)
 	if pkgPath != "" {
+		// TODO: export validation from android/paths.go handling to replace this duplicated functionality
 		pkgPath = filepath.Clean(String(p.properties.Pkg_path))
 		if pkgPath == ".." || strings.HasPrefix(pkgPath, "../") ||
 			strings.HasPrefix(pkgPath, "/") {
@@ -448,22 +484,35 @@
 				String(p.properties.Pkg_path))
 			return
 		}
-		if p.properties.Is_internal != nil && *p.properties.Is_internal {
-			pkgPath = filepath.Join(internal, pkgPath)
-		}
-	} else {
-		if p.properties.Is_internal != nil && *p.properties.Is_internal {
-			pkgPath = internal
-		}
+	}
+	// If property Is_internal is set, prepend pkgPath with internalPath
+	if proptools.BoolDefault(p.properties.Is_internal, false) {
+		pkgPath = filepath.Join(internalPath, pkgPath)
 	}
 
+	// generate src:destination path mappings for this module
 	p.genModulePathMappings(ctx, pkgPath, expandedSrcs, expandedData)
 
+	// generate the zipfile of all source and data files
 	p.srcsZip = p.createSrcsZip(ctx, pkgPath)
 }
 
-// generate current module unique pathMappings: <dest: runfiles_path, src: source_path>
-// for python/data files.
+func isValidPythonPath(path string) error {
+	identifiers := strings.Split(strings.TrimSuffix(path, filepath.Ext(path)), "/")
+	for _, token := range identifiers {
+		if !pathComponentRegexp.MatchString(token) {
+			return fmt.Errorf("the path %q contains invalid subpath %q. "+
+				"Subpaths must be at least one character long. "+
+				"The first character must an underscore or letter. "+
+				"Following characters may be any of: letter, digit, underscore, hyphen.",
+				path, token)
+		}
+	}
+	return nil
+}
+
+// For this module, generate unique pathMappings: <dest: runfiles_path, src: source_path>
+// for python/data files expanded from properties.
 func (p *Module) genModulePathMappings(ctx android.ModuleContext, pkgPath string,
 	expandedSrcs, expandedData android.Paths) {
 	// fetch <runfiles_path, source_path> pairs from "src" and "data" properties to
@@ -477,17 +526,11 @@
 			continue
 		}
 		runfilesPath := filepath.Join(pkgPath, s.Rel())
-		identifiers := strings.Split(strings.TrimSuffix(runfilesPath,
-			filepath.Ext(runfilesPath)), "/")
-		for _, token := range identifiers {
-			if !pyIdentifierRegexp.MatchString(token) {
-				ctx.PropertyErrorf("srcs", "the path %q contains invalid token %q.",
-					runfilesPath, token)
-			}
+		if err := isValidPythonPath(runfilesPath); err != nil {
+			ctx.PropertyErrorf("srcs", err.Error())
 		}
-		if fillInMap(ctx, destToPySrcs, runfilesPath, s.String(), p.Name(), p.Name()) {
-			p.srcsPathMappings = append(p.srcsPathMappings,
-				pathMapping{dest: runfilesPath, src: s})
+		if !checkForDuplicateOutputPath(ctx, destToPySrcs, runfilesPath, s.String(), p.Name(), p.Name()) {
+			p.srcsPathMappings = append(p.srcsPathMappings, pathMapping{dest: runfilesPath, src: s})
 		}
 	}
 
@@ -497,22 +540,23 @@
 			continue
 		}
 		runfilesPath := filepath.Join(pkgPath, d.Rel())
-		if fillInMap(ctx, destToPyData, runfilesPath, d.String(), p.Name(), p.Name()) {
+		if !checkForDuplicateOutputPath(ctx, destToPyData, runfilesPath, d.String(), p.Name(), p.Name()) {
 			p.dataPathMappings = append(p.dataPathMappings,
 				pathMapping{dest: runfilesPath, src: d})
 		}
 	}
 }
 
-// register build actions to zip current module's sources.
+// createSrcsZip registers build actions to zip current module's sources and data.
 func (p *Module) createSrcsZip(ctx android.ModuleContext, pkgPath string) android.Path {
 	relativeRootMap := make(map[string]android.Paths)
 	pathMappings := append(p.srcsPathMappings, p.dataPathMappings...)
 
 	var protoSrcs android.Paths
-	// "srcs" or "data" properties may have filegroup so it might happen that
-	// the relative root for each source path is different.
+	// "srcs" or "data" properties may contain filegroup so it might happen that
+	// the root directory for each source path is different.
 	for _, path := range pathMappings {
+		// handle proto sources separately
 		if path.src.Ext() == protoExt {
 			protoSrcs = append(protoSrcs, path.src)
 		} else {
@@ -537,24 +581,21 @@
 	}
 
 	if len(relativeRootMap) > 0 {
-		var keys []string
-
 		// in order to keep stable order of soong_zip params, we sort the keys here.
-		for k := range relativeRootMap {
-			keys = append(keys, k)
-		}
-		sort.Strings(keys)
+		roots := android.SortedStringKeys(relativeRootMap)
 
 		parArgs := []string{}
 		if pkgPath != "" {
+			// use package path as path prefix
 			parArgs = append(parArgs, `-P `+pkgPath)
 		}
-		implicits := android.Paths{}
-		for _, k := range keys {
-			parArgs = append(parArgs, `-C `+k)
-			for _, path := range relativeRootMap[k] {
+		paths := android.Paths{}
+		for _, root := range roots {
+			// specify relative root of file in following -f arguments
+			parArgs = append(parArgs, `-C `+root)
+			for _, path := range relativeRootMap[root] {
 				parArgs = append(parArgs, `-f `+path.String())
-				implicits = append(implicits, path)
+				paths = append(paths, path)
 			}
 		}
 
@@ -563,13 +604,15 @@
 			Rule:        zip,
 			Description: "python library archive",
 			Output:      origSrcsZip,
-			Implicits:   implicits,
+			// as zip rule does not use $in, there is no real need to distinguish between Inputs and Implicits
+			Implicits: paths,
 			Args: map[string]string{
 				"args": strings.Join(parArgs, " "),
 			},
 		})
 		zips = append(zips, origSrcsZip)
 	}
+	// we may have multiple zips due to separate handling of proto source files
 	if len(zips) == 1 {
 		return zips[0]
 	} else {
@@ -584,25 +627,27 @@
 	}
 }
 
+// isPythonLibModule returns whether the given module is a Python library Module or not
+// This is distinguished by the fact that Python libraries are not installable, while other Python
+// modules are.
 func isPythonLibModule(module blueprint.Module) bool {
 	if m, ok := module.(*Module); ok {
-		// Python library has no bootstrapper or installer.
-		if m.bootstrapper != nil || m.installer != nil {
-			return false
+		// Python library has no bootstrapper or installer
+		if m.bootstrapper == nil && m.installer == nil {
+			return true
 		}
-		return true
 	}
 	return false
 }
 
-// check Python source/data files duplicates for whole runfiles tree since Python binary/test
-// need collect and zip all srcs of whole transitive dependencies to a final par file.
-func (p *Module) walkTransitiveDeps(ctx android.ModuleContext) {
+// collectPathsFromTransitiveDeps checks for source/data files for duplicate paths
+// for module and its transitive dependencies and collects list of data/source file
+// zips for transitive dependencies.
+func (p *Module) collectPathsFromTransitiveDeps(ctx android.ModuleContext) {
 	// fetch <runfiles_path, source_path> pairs from "src" and "data" properties to
 	// check duplicates.
 	destToPySrcs := make(map[string]string)
 	destToPyData := make(map[string]string)
-
 	for _, path := range p.srcsPathMappings {
 		destToPySrcs[path.dest] = path.src.String()
 	}
@@ -614,6 +659,7 @@
 
 	// visit all its dependencies in depth first.
 	ctx.WalkDeps(func(child, parent android.Module) bool {
+		// we only collect dependencies tagged as python library deps
 		if ctx.OtherModuleDependencyTag(child) != pythonLibTag {
 			return false
 		}
@@ -623,44 +669,46 @@
 		seen[child] = true
 		// Python modules only can depend on Python libraries.
 		if !isPythonLibModule(child) {
-			panic(fmt.Errorf(
+			ctx.PropertyErrorf("libs",
 				"the dependency %q of module %q is not Python library!",
-				ctx.ModuleName(), ctx.OtherModuleName(child)))
+				ctx.ModuleName(), ctx.OtherModuleName(child))
 		}
-		if dep, ok := child.(PythonDependency); ok {
-			srcs := dep.GetSrcsPathMappings()
+		// collect source and data paths, checking that there are no duplicate output file conflicts
+		if dep, ok := child.(pythonDependency); ok {
+			srcs := dep.getSrcsPathMappings()
 			for _, path := range srcs {
-				if !fillInMap(ctx, destToPySrcs,
-					path.dest, path.src.String(), ctx.ModuleName(), ctx.OtherModuleName(child)) {
-					continue
-				}
-			}
-			data := dep.GetDataPathMappings()
-			for _, path := range data {
-				fillInMap(ctx, destToPyData,
+				checkForDuplicateOutputPath(ctx, destToPySrcs,
 					path.dest, path.src.String(), ctx.ModuleName(), ctx.OtherModuleName(child))
 			}
-			p.depsSrcsZips = append(p.depsSrcsZips, dep.GetSrcsZip())
+			data := dep.getDataPathMappings()
+			for _, path := range data {
+				checkForDuplicateOutputPath(ctx, destToPyData,
+					path.dest, path.src.String(), ctx.ModuleName(), ctx.OtherModuleName(child))
+			}
+			p.depsSrcsZips = append(p.depsSrcsZips, dep.getSrcsZip())
 		}
 		return true
 	})
 }
 
-func fillInMap(ctx android.ModuleContext, m map[string]string,
-	key, value, curModule, otherModule string) bool {
-	if oldValue, found := m[key]; found {
+// chckForDuplicateOutputPath checks whether outputPath has already been included in map m, which
+// would result in two files being placed in the same location.
+// If there is a duplicate path, an error is thrown and true is returned
+// Otherwise, outputPath: srcPath is added to m and returns false
+func checkForDuplicateOutputPath(ctx android.ModuleContext, m map[string]string, outputPath, srcPath, curModule, otherModule string) bool {
+	if oldSrcPath, found := m[outputPath]; found {
 		ctx.ModuleErrorf("found two files to be placed at the same location within zip %q."+
 			" First file: in module %s at path %q."+
 			" Second file: in module %s at path %q.",
-			key, curModule, oldValue, otherModule, value)
-		return false
-	} else {
-		m[key] = value
+			outputPath, curModule, oldSrcPath, otherModule, srcPath)
+		return true
 	}
+	m[outputPath] = srcPath
 
-	return true
+	return false
 }
 
+// InstallInData returns true as Python is not supported in the system partition
 func (p *Module) InstallInData() bool {
 	return true
 }
diff --git a/python/python_test.go b/python/python_test.go
index 64bc4f6..5c4efa7 100644
--- a/python/python_test.go
+++ b/python/python_test.go
@@ -44,7 +44,7 @@
 	pkgPathErrTemplate       = moduleVariantErrTemplate +
 		"pkg_path: %q must be a relative path contained in par file."
 	badIdentifierErrTemplate = moduleVariantErrTemplate +
-		"srcs: the path %q contains invalid token %q."
+		"srcs: the path %q contains invalid subpath %q."
 	dupRunfileErrTemplate = moduleVariantErrTemplate +
 		"found two files to be placed at the same location within zip %q." +
 		" First file: in module %s at path %q." +
@@ -370,7 +370,7 @@
 	} else {
 		sort.Strings(expErrs)
 		for i, v := range actErrStrs {
-			if v != expErrs[i] {
+			if !strings.Contains(v, expErrs[i]) {
 				testErrs = append(testErrs, errors.New(v))
 			}
 		}
diff --git a/python/test.go b/python/test.go
index 4df71c1..b7cd475 100644
--- a/python/test.go
+++ b/python/test.go
@@ -108,12 +108,12 @@
 func PythonTestHostFactory() android.Module {
 	module := NewTest(android.HostSupportedNoCross)
 
-	return module.Init()
+	return module.init()
 }
 
 func PythonTestFactory() android.Module {
 	module := NewTest(android.HostAndDeviceSupported)
 	module.multilib = android.MultilibBoth
 
-	return module.Init()
+	return module.init()
 }
diff --git a/rust/project_json.go b/rust/project_json.go
index 8d9e50c..c4d60ad 100644
--- a/rust/project_json.go
+++ b/rust/project_json.go
@@ -75,12 +75,16 @@
 	android.RegisterSingletonType("rust_project_generator", rustProjectGeneratorSingleton)
 }
 
-// librarySource finds the main source file (.rs) for a crate.
-func librarySource(ctx android.SingletonContext, rModule *Module, rustLib *libraryDecorator) (string, bool) {
-	srcs := rustLib.baseCompiler.Properties.Srcs
+// crateSource finds the main source file (.rs) for a crate.
+func crateSource(ctx android.SingletonContext, rModule *Module, comp *baseCompiler) (string, bool) {
+	srcs := comp.Properties.Srcs
 	if len(srcs) != 0 {
 		return path.Join(ctx.ModuleDir(rModule), srcs[0]), true
 	}
+	rustLib, ok := rModule.compiler.(*libraryDecorator)
+	if !ok {
+		return "", false
+	}
 	if !rustLib.source() {
 		return "", false
 	}
@@ -132,8 +136,15 @@
 	if rModule.compiler == nil {
 		return 0, "", false
 	}
-	rustLib, ok := rModule.compiler.(*libraryDecorator)
-	if !ok {
+	var comp *baseCompiler
+	switch c := rModule.compiler.(type) {
+	case *libraryDecorator:
+		comp = c.baseCompiler
+	case *binaryDecorator:
+		comp = c.baseCompiler
+	case *testDecorator:
+		comp = c.binaryDecorator.baseCompiler
+	default:
 		return 0, "", false
 	}
 	moduleName := ctx.ModuleName(module)
@@ -146,12 +157,12 @@
 		return cInfo.ID, crateName, true
 	}
 	crate := rustProjectCrate{Deps: make([]rustProjectDep, 0), Cfgs: make([]string, 0)}
-	rootModule, ok := librarySource(ctx, rModule, rustLib)
+	rootModule, ok := crateSource(ctx, rModule, comp)
 	if !ok {
 		return 0, "", false
 	}
 	crate.RootModule = rootModule
-	crate.Edition = rustLib.baseCompiler.edition()
+	crate.Edition = comp.edition()
 
 	deps := make(map[string]int)
 	singleton.mergeDependencies(ctx, module, &crate, deps)
diff --git a/rust/project_json_test.go b/rust/project_json_test.go
index 16699c1..aff1697 100644
--- a/rust/project_json_test.go
+++ b/rust/project_json_test.go
@@ -67,6 +67,37 @@
 	return crates
 }
 
+// validateCrate ensures that a crate can be parsed as a map.
+func validateCrate(t *testing.T, crate interface{}) map[string]interface{} {
+	c, ok := crate.(map[string]interface{})
+	if !ok {
+		t.Fatalf("Unexpected type for crate: %v", c)
+	}
+	return c
+}
+
+// validateDependencies parses the dependencies for a crate. It returns a list
+// of the dependencies name.
+func validateDependencies(t *testing.T, crate map[string]interface{}) []string {
+	var dependencies []string
+	deps, ok := crate["deps"].([]interface{})
+	if !ok {
+		t.Errorf("Unexpected format for deps: %v", crate["deps"])
+	}
+	for _, dep := range deps {
+		d, ok := dep.(map[string]interface{})
+		if !ok {
+			t.Errorf("Unexpected format for dependency: %v", dep)
+		}
+		name, ok := d["name"].(string)
+		if !ok {
+			t.Errorf("Dependency is missing the name key: %v", d)
+		}
+		dependencies = append(dependencies, name)
+	}
+	return dependencies
+}
+
 func TestProjectJsonDep(t *testing.T) {
 	bp := `
 	rust_library {
@@ -85,6 +116,29 @@
 	validateJsonCrates(t, jsonContent)
 }
 
+func TestProjectJsonBinary(t *testing.T) {
+	bp := `
+	rust_binary {
+		name: "liba",
+		srcs: ["a/src/lib.rs"],
+		crate_name: "a"
+	}
+	`
+	jsonContent := testProjectJson(t, bp)
+	crates := validateJsonCrates(t, jsonContent)
+	for _, c := range crates {
+		crate := validateCrate(t, c)
+		rootModule, ok := crate["root_module"].(string)
+		if !ok {
+			t.Fatalf("Unexpected type for root_module: %v", crate["root_module"])
+		}
+		if rootModule == "a/src/lib.rs" {
+			return
+		}
+	}
+	t.Errorf("Entry for binary %q not found: %s", "a", jsonContent)
+}
+
 func TestProjectJsonBindGen(t *testing.T) {
 	bp := `
 	rust_library {
@@ -116,10 +170,7 @@
 	jsonContent := testProjectJson(t, bp)
 	crates := validateJsonCrates(t, jsonContent)
 	for _, c := range crates {
-		crate, ok := c.(map[string]interface{})
-		if !ok {
-			t.Fatalf("Unexpected type for crate: %v", c)
-		}
+		crate := validateCrate(t, c)
 		rootModule, ok := crate["root_module"].(string)
 		if !ok {
 			t.Fatalf("Unexpected type for root_module: %v", crate["root_module"])
@@ -133,16 +184,8 @@
 		}
 		// Check that libbindings1 does not depend on itself.
 		if strings.Contains(rootModule, "libbindings1") {
-			deps, ok := crate["deps"].([]interface{})
-			if !ok {
-				t.Errorf("Unexpected format for deps: %v", crate["deps"])
-			}
-			for _, dep := range deps {
-				d, ok := dep.(map[string]interface{})
-				if !ok {
-					t.Errorf("Unexpected format for dep: %v", dep)
-				}
-				if d["name"] == "bindings1" {
+			for _, depName := range validateDependencies(t, crate) {
+				if depName == "bindings1" {
 					t.Errorf("libbindings1 depends on itself")
 				}
 			}
@@ -171,20 +214,18 @@
 	`
 	jsonContent := testProjectJson(t, bp)
 	crates := validateJsonCrates(t, jsonContent)
-	for _, crate := range crates {
-		c := crate.(map[string]interface{})
-		if c["root_module"] == "b/src/lib.rs" {
-			deps, ok := c["deps"].([]interface{})
-			if !ok {
-				t.Errorf("Unexpected format for deps: %v", c["deps"])
-			}
+	for _, c := range crates {
+		crate := validateCrate(t, c)
+		rootModule, ok := crate["root_module"].(string)
+		if !ok {
+			t.Fatalf("Unexpected type for root_module: %v", crate["root_module"])
+		}
+		// Make sure that b has 2 different dependencies.
+		if rootModule == "b/src/lib.rs" {
 			aCount := 0
-			for _, dep := range deps {
-				d, ok := dep.(map[string]interface{})
-				if !ok {
-					t.Errorf("Unexpected format for dep: %v", dep)
-				}
-				if d["name"] == "a" {
+			deps := validateDependencies(t, crate)
+			for _, depName := range deps {
+				if depName == "a" {
 					aCount++
 				}
 			}
diff --git a/scripts/gen_ndk_usedby_apex.sh b/scripts/gen_ndk_usedby_apex.sh
new file mode 100755
index 0000000..f143161
--- /dev/null
+++ b/scripts/gen_ndk_usedby_apex.sh
@@ -0,0 +1,72 @@
+#!/bin/bash -e
+
+# Copyright 2020 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Generates NDK API txt file used by Mainline modules. NDK APIs would have value
+# "UND" in Ndx column and have suffix "@LIB_NAME" in Name column.
+# For example, current line llvm-readelf output is:
+# 1: 00000000     0     FUNC      GLOBAL  DEFAULT   UND   dlopen@LIBC
+# After the parse function below "dlopen" would be write to the output file.
+printHelp() {
+    echo "**************************** Usage Instructions ****************************"
+    echo "This script is used to generate the Mainline modules used-by NDK symbols."
+    echo ""
+    echo "To run this script use: ./ndk_usedby_module.sh \$BINARY_IMAGE_DIRECTORY \$BINARY_LLVM_PATH \$OUTPUT_FILE_PATH"
+    echo "For example: If all the module image files that you would like to run is under directory '/myModule' and output write to /myModule.txt then the command would be:"
+    echo "./ndk_usedby_module.sh /myModule \$BINARY_LLVM_PATH /myModule.txt"
+}
+
+parseReadelfOutput() {
+  while IFS= read -r line
+  do
+      if [[ $line = *FUNC*GLOBAL*UND*@* ]] ;
+      then
+          echo "$line" | sed -r 's/.*UND (.*)@.*/\1/g' >> "$2"
+      fi
+  done < "$1"
+  echo "" >> "$2"
+}
+
+unzipJarAndApk() {
+  tmpUnzippedDir="$1"/tmpUnzipped
+  [[ -e "$tmpUnzippedDir" ]] && rm -rf "$tmpUnzippedDir"
+  mkdir -p "$tmpUnzippedDir"
+  find "$1" -name "*.jar" -exec unzip -o {} -d "$tmpUnzippedDir" \;
+  find "$1" -name "*.apk" -exec unzip -o {} -d "$tmpUnzippedDir" \;
+  find "$tmpUnzippedDir" -name "*.MF" -exec rm {} \;
+}
+
+lookForExecFile() {
+  dir="$1"
+  readelf="$2"
+  find "$dir" -type f -name "*.so"  -exec "$2" --dyn-symbols {} >> "$dir"/../tmpReadelf.txt \;
+  find "$dir" -type f -perm /111 ! -name "*.so"  -exec "$2" --dyn-symbols {} >> "$dir"/../tmpReadelf.txt \;
+}
+
+if [[ "$1" == "help" ]]
+then
+  printHelp
+elif [[ "$#" -ne 3 ]]
+then
+  echo "Wrong argument length. Expecting 3 argument representing image file directory, llvm-readelf tool path, output path."
+else
+  unzipJarAndApk "$1"
+  lookForExecFile "$1" "$2"
+  tmpReadelfOutput="$1/../tmpReadelf.txt"
+  [[ -e "$3" ]] && rm "$3"
+  parseReadelfOutput "$tmpReadelfOutput" "$3"
+  [[ -e "$tmpReadelfOutput" ]] && rm "$tmpReadelfOutput"
+  rm -rf "$1/tmpUnzipped"
+fi
\ No newline at end of file
diff --git a/ui/build/bazel.go b/ui/build/bazel.go
index 2d36f67..fac0461 100644
--- a/ui/build/bazel.go
+++ b/ui/build/bazel.go
@@ -24,6 +24,28 @@
 	"android/soong/ui/metrics"
 )
 
+func getBazelInfo(ctx Context, config Config, bazelExecutable string, query string) string {
+	infoCmd := Command(ctx, config, "bazel", bazelExecutable)
+
+	if extraStartupArgs, ok := infoCmd.Environment.Get("BAZEL_STARTUP_ARGS"); ok {
+		infoCmd.Args = append(infoCmd.Args, strings.Fields(extraStartupArgs)...)
+	}
+
+	// Obtain the output directory path in the execution root.
+	infoCmd.Args = append(infoCmd.Args,
+		"info",
+		query,
+	)
+
+	infoCmd.Environment.Set("DIST_DIR", config.DistDir())
+	infoCmd.Environment.Set("SHELL", "/bin/bash")
+
+	infoCmd.Dir = filepath.Join(config.OutDir(), "..")
+
+	queryResult := strings.TrimSpace(string(infoCmd.OutputOrFatal()))
+	return queryResult
+}
+
 // 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) {
@@ -76,16 +98,36 @@
 		"--slim_profile=true",
 	)
 
-	// Append custom build flags to the Bazel command. Changes to these flags
-	// may invalidate Bazel's analysis cache.
-	if extraBuildArgs, ok := cmd.Environment.Get("BAZEL_BUILD_ARGS"); ok {
-		cmd.Args = append(cmd.Args, strings.Fields(extraBuildArgs)...)
-	}
+	if config.UseRBE() {
+		for _, envVar := range []string{
+			// RBE client
+			"RBE_compare",
+			"RBE_exec_strategy",
+			"RBE_invocation_id",
+			"RBE_log_dir",
+			"RBE_platform",
+			"RBE_remote_accept_cache",
+			"RBE_remote_update_cache",
+			"RBE_server_address",
+			// TODO: remove old FLAG_ variables.
+			"FLAG_compare",
+			"FLAG_exec_root",
+			"FLAG_exec_strategy",
+			"FLAG_invocation_id",
+			"FLAG_log_dir",
+			"FLAG_platform",
+			"FLAG_remote_accept_cache",
+			"FLAG_remote_update_cache",
+			"FLAG_server_address",
+		} {
+			cmd.Args = append(cmd.Args,
+				"--action_env="+envVar)
+		}
 
-	// Append the label of the default ninja_build target.
-	cmd.Args = append(cmd.Args,
-		"//:"+config.TargetProduct()+"-"+config.TargetBuildVariant(),
-	)
+		// We need to calculate --RBE_exec_root ourselves
+		ctx.Println("Getting Bazel execution_root...")
+		cmd.Args = append(cmd.Args, "--action_env=RBE_exec_root="+getBazelInfo(ctx, config, bazelExecutable, "execution_root"))
+	}
 
 	// Ensure that the PATH environment variable value used in the action
 	// environment is the restricted set computed from soong_ui, and not a
@@ -95,6 +137,18 @@
 		cmd.Args = append(cmd.Args, "--action_env=PATH="+pathEnvValue)
 	}
 
+	// Append custom build flags to the Bazel command. Changes to these flags
+	// may invalidate Bazel's analysis cache.
+	// These should be appended as the final args, so that they take precedence.
+	if extraBuildArgs, ok := cmd.Environment.Get("BAZEL_BUILD_ARGS"); ok {
+		cmd.Args = append(cmd.Args, strings.Fields(extraBuildArgs)...)
+	}
+
+	// Append the label of the default ninja_build target.
+	cmd.Args = append(cmd.Args,
+		"//:"+config.TargetProduct()+"-"+config.TargetBuildVariant(),
+	)
+
 	cmd.Environment.Set("DIST_DIR", config.DistDir())
 	cmd.Environment.Set("SHELL", "/bin/bash")
 
@@ -113,24 +167,8 @@
 	// Ensure that the $OUT_DIR contains the expected set of files by symlinking
 	// the files from the execution root's output direction into $OUT_DIR.
 
-	// Obtain the Bazel output directory for ninja_build.
-	infoCmd := Command(ctx, config, "bazel", bazelExecutable)
-
-	if extraStartupArgs, ok := infoCmd.Environment.Get("BAZEL_STARTUP_ARGS"); ok {
-		infoCmd.Args = append(infoCmd.Args, strings.Fields(extraStartupArgs)...)
-	}
-
-	// Obtain the output directory path in the execution root.
-	infoCmd.Args = append(infoCmd.Args,
-		"info",
-		"output_path",
-	)
-
-	infoCmd.Environment.Set("DIST_DIR", config.DistDir())
-	infoCmd.Environment.Set("SHELL", "/bin/bash")
-	infoCmd.Dir = filepath.Join(config.OutDir(), "..")
-	ctx.Status.Status("Getting Bazel Info..")
-	outputBasePath := string(infoCmd.OutputOrFatal())
+	ctx.Println("Getting Bazel output_path...")
+	outputBasePath := getBazelInfo(ctx, config, bazelExecutable, "output_path")
 	// TODO: Don't hardcode out/ as the bazel output directory. This is
 	// currently hardcoded as ninja_build.output_root.
 	bazelNinjaBuildOutputRoot := filepath.Join(outputBasePath, "..", "out")