Merge "Sandbox r8retrace genrules" into main
diff --git a/aconfig/init.go b/aconfig/init.go
index 3d62714..626e66d 100644
--- a/aconfig/init.go
+++ b/aconfig/init.go
@@ -40,7 +40,7 @@
 			Restat: true,
 		}, "release_version", "package", "declarations", "values", "default-permission")
 
-	// For java_aconfig_library: Generate java file
+	// For java_aconfig_library: Generate java library
 	javaRule = pctx.AndroidStaticRule("java_aconfig_library",
 		blueprint.RuleParams{
 			Command: `rm -rf ${out}.tmp` +
@@ -58,7 +58,7 @@
 			Restat: true,
 		}, "mode")
 
-	// For java_aconfig_library: Generate java file
+	// For cc_aconfig_library: Generate C++ library
 	cppRule = pctx.AndroidStaticRule("cc_aconfig_library",
 		blueprint.RuleParams{
 			Command: `rm -rf ${gendir}` +
@@ -69,10 +69,10 @@
 				`    --out ${gendir}`,
 			CommandDeps: []string{
 				"$aconfig",
-				"$soong_zip",
 			},
 		}, "gendir", "mode")
 
+	// For rust_aconfig_library: Generate Rust library
 	rustRule = pctx.AndroidStaticRule("rust_aconfig_library",
 		blueprint.RuleParams{
 			Command: `rm -rf ${gendir}` +
@@ -83,11 +83,10 @@
 				`    --out ${gendir}`,
 			CommandDeps: []string{
 				"$aconfig",
-				"$soong_zip",
 			},
 		}, "gendir", "mode")
 
-	// For all_aconfig_declarations
+	// For all_aconfig_declarations: Combine all parsed_flags proto files
 	allDeclarationsRule = pctx.AndroidStaticRule("all_aconfig_declarations_dump",
 		blueprint.RuleParams{
 			Command: `${aconfig} dump --format protobuf --out ${out} ${cache_files}`,
diff --git a/android/module_context.go b/android/module_context.go
index 0b4d28c..a0a4104 100644
--- a/android/module_context.go
+++ b/android/module_context.go
@@ -114,7 +114,7 @@
 	// installed file will be returned by PackagingSpecs() on this module or by
 	// TransitivePackagingSpecs() on modules that depend on this module through dependency tags
 	// for which IsInstallDepNeeded returns true.
-	InstallExecutable(installPath InstallPath, name string, srcPath Path, deps ...Path) InstallPath
+	InstallExecutable(installPath InstallPath, name string, srcPath Path, deps ...InstallPath) InstallPath
 
 	// InstallFile creates a rule to copy srcPath to name in the installPath directory,
 	// with the given additional dependencies.
@@ -123,7 +123,7 @@
 	// installed file will be returned by PackagingSpecs() on this module or by
 	// TransitivePackagingSpecs() on modules that depend on this module through dependency tags
 	// for which IsInstallDepNeeded returns true.
-	InstallFile(installPath InstallPath, name string, srcPath Path, deps ...Path) InstallPath
+	InstallFile(installPath InstallPath, name string, srcPath Path, deps ...InstallPath) InstallPath
 
 	// InstallFileWithExtraFilesZip creates a rule to copy srcPath to name in the installPath
 	// directory, and also unzip a zip file containing extra files to install into the same
@@ -133,7 +133,7 @@
 	// installed file will be returned by PackagingSpecs() on this module or by
 	// TransitivePackagingSpecs() on modules that depend on this module through dependency tags
 	// for which IsInstallDepNeeded returns true.
-	InstallFileWithExtraFilesZip(installPath InstallPath, name string, srcPath Path, extraZip Path, deps ...Path) InstallPath
+	InstallFileWithExtraFilesZip(installPath InstallPath, name string, srcPath Path, extraZip Path, deps ...InstallPath) InstallPath
 
 	// InstallSymlink creates a rule to create a symlink from src srcPath to name in the installPath
 	// directory.
@@ -451,17 +451,17 @@
 }
 
 func (m *moduleContext) InstallFile(installPath InstallPath, name string, srcPath Path,
-	deps ...Path) InstallPath {
+	deps ...InstallPath) InstallPath {
 	return m.installFile(installPath, name, srcPath, deps, false, nil)
 }
 
 func (m *moduleContext) InstallExecutable(installPath InstallPath, name string, srcPath Path,
-	deps ...Path) InstallPath {
+	deps ...InstallPath) InstallPath {
 	return m.installFile(installPath, name, srcPath, deps, true, nil)
 }
 
 func (m *moduleContext) InstallFileWithExtraFilesZip(installPath InstallPath, name string, srcPath Path,
-	extraZip Path, deps ...Path) InstallPath {
+	extraZip Path, deps ...InstallPath) InstallPath {
 	return m.installFile(installPath, name, srcPath, deps, false, &extraFilesZip{
 		zip: extraZip,
 		dir: installPath,
@@ -487,23 +487,23 @@
 	return spec
 }
 
-func (m *moduleContext) installFile(installPath InstallPath, name string, srcPath Path, deps []Path,
+func (m *moduleContext) installFile(installPath InstallPath, name string, srcPath Path, deps []InstallPath,
 	executable bool, extraZip *extraFilesZip) InstallPath {
 
 	fullInstallPath := installPath.Join(m, name)
 	m.module.base().hooks.runInstallHooks(m, srcPath, fullInstallPath, false)
 
 	if !m.skipInstall() {
-		deps = append(deps, InstallPaths(m.module.base().installFilesDepSet.ToList()).Paths()...)
+		deps = append(deps, InstallPaths(m.module.base().installFilesDepSet.ToList())...)
 
 		var implicitDeps, orderOnlyDeps Paths
 
 		if m.Host() {
 			// Installed host modules might be used during the build, depend directly on their
 			// dependencies so their timestamp is updated whenever their dependency is updated
-			implicitDeps = deps
+			implicitDeps = InstallPaths(deps).Paths()
 		} else {
-			orderOnlyDeps = deps
+			orderOnlyDeps = InstallPaths(deps).Paths()
 		}
 
 		if m.Config().KatiEnabled() {
diff --git a/android/paths.go b/android/paths.go
index a6cda38..37504b6 100644
--- a/android/paths.go
+++ b/android/paths.go
@@ -2210,6 +2210,14 @@
 	RelativeInstallPath string
 }
 
+func (d *DataPath) ToRelativeInstallPath() string {
+	relPath := d.SrcPath.Rel()
+	if d.RelativeInstallPath != "" {
+		relPath = filepath.Join(d.RelativeInstallPath, relPath)
+	}
+	return relPath
+}
+
 // PathsIfNonNil returns a Paths containing only the non-nil input arguments.
 func PathsIfNonNil(paths ...Path) Paths {
 	if len(paths) == 0 {
diff --git a/apex/apex.go b/apex/apex.go
index 4c02305..ecc794b 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -1890,7 +1890,7 @@
 		installSuffix = imageCapexSuffix
 	}
 	a.installedFile = ctx.InstallFile(a.installDir, a.Name()+installSuffix, a.outputFile,
-		a.compatSymlinks.Paths()...)
+		a.compatSymlinks...)
 
 	// filesInfo in mixed mode must retrieve all information about the apex's
 	// contents completely from the Starlark providers. It should never rely on
diff --git a/apex/builder.go b/apex/builder.go
index ba4df5f..3f358ac 100644
--- a/apex/builder.go
+++ b/apex/builder.go
@@ -344,10 +344,12 @@
 func (a *apexBundle) buildFileContexts(ctx android.ModuleContext) android.OutputPath {
 	var fileContexts android.Path
 	var fileContextsDir string
+	isFileContextsModule := false
 	if a.properties.File_contexts == nil {
 		fileContexts = android.PathForSource(ctx, "system/sepolicy/apex", ctx.ModuleName()+"-file_contexts")
 	} else {
 		if m, t := android.SrcIsModuleWithTag(*a.properties.File_contexts); m != "" {
+			isFileContextsModule = true
 			otherModule := android.GetModuleFromPathDep(ctx, m, t)
 			fileContextsDir = ctx.OtherModuleDir(otherModule)
 		}
@@ -363,7 +365,7 @@
 			ctx.PropertyErrorf("file_contexts", "should be under system/sepolicy, but found in  %q", fileContextsDir)
 		}
 	}
-	if !android.ExistentPathForSource(ctx, fileContexts.String()).Valid() {
+	if !isFileContextsModule && !android.ExistentPathForSource(ctx, fileContexts.String()).Valid() {
 		ctx.PropertyErrorf("file_contexts", "cannot find file_contexts file: %q", fileContexts.String())
 	}
 
@@ -563,13 +565,8 @@
 		// Copy the test files (if any)
 		for _, d := range fi.dataPaths {
 			// TODO(eakammer): This is now the third repetition of ~this logic for test paths, refactoring should be possible
-			relPath := d.SrcPath.Rel()
-			dataPath := d.SrcPath.String()
-			if !strings.HasSuffix(dataPath, relPath) {
-				panic(fmt.Errorf("path %q does not end with %q", dataPath, relPath))
-			}
-
-			dataDest := imageDir.Join(ctx, fi.apexRelativePath(relPath), d.RelativeInstallPath).String()
+			relPath := d.ToRelativeInstallPath()
+			dataDest := imageDir.Join(ctx, fi.apexRelativePath(relPath)).String()
 
 			copyCommands = append(copyCommands, "cp -f "+d.SrcPath.String()+" "+dataDest)
 			implicitInputs = append(implicitInputs, d.SrcPath)
@@ -956,7 +953,7 @@
 
 	// Install to $OUT/soong/{target,host}/.../apex.
 	a.installedFile = ctx.InstallFile(a.installDir, a.Name()+installSuffix, a.outputFile,
-		a.compatSymlinks.Paths()...)
+		a.compatSymlinks...)
 
 	// installed-files.txt is dist'ed
 	a.installedFilesFile = a.buildInstalledFilesFile(ctx, a.outputFile, imageDir)
@@ -1095,7 +1092,8 @@
 		if f.installDir == "bin" || strings.HasPrefix(f.installDir, "bin/") {
 			executablePaths = append(executablePaths, pathInApex)
 			for _, d := range f.dataPaths {
-				readOnlyPaths = append(readOnlyPaths, filepath.Join(f.installDir, d.RelativeInstallPath, d.SrcPath.Rel()))
+				rel := d.ToRelativeInstallPath()
+				readOnlyPaths = append(readOnlyPaths, filepath.Join(f.installDir, rel))
 			}
 			for _, s := range f.symlinks {
 				executablePaths = append(executablePaths, filepath.Join(f.installDir, s))
diff --git a/apex/prebuilt.go b/apex/prebuilt.go
index 7a9d23e..7d339d5 100644
--- a/apex/prebuilt.go
+++ b/apex/prebuilt.go
@@ -794,7 +794,7 @@
 	}
 
 	if p.installable() {
-		p.installedFile = ctx.InstallFile(p.installDir, p.installFilename, p.inputApex, p.compatSymlinks.Paths()...)
+		p.installedFile = ctx.InstallFile(p.installDir, p.installFilename, p.inputApex, p.compatSymlinks...)
 		p.provenanceMetaDataFile = provenance.GenerateArtifactProvenanceMetaData(ctx, p.inputApex, p.installedFile)
 	}
 }
diff --git a/cc/Android.bp b/cc/Android.bp
index 8fa0fbe..77e96db 100644
--- a/cc/Android.bp
+++ b/cc/Android.bp
@@ -19,6 +19,7 @@
         "soong-multitree",
         "soong-snapshot",
         "soong-sysprop-bp2build",
+        "soong-testing",
         "soong-tradefed",
     ],
     srcs: [
diff --git a/cc/builder.go b/cc/builder.go
index 3f582fa..69cf75b 100644
--- a/cc/builder.go
+++ b/cc/builder.go
@@ -681,16 +681,11 @@
 			tidyCmd := "${config.ClangBin}/clang-tidy"
 
 			rule := clangTidy
-			reducedCFlags := moduleFlags
 			if ctx.Config().UseRBE() && ctx.Config().IsEnvTrue("RBE_CLANG_TIDY") {
 				rule = clangTidyRE
-				// b/248371171, work around RBE input processor problem
-				// some cflags rejected by input processor, but usually
-				// do not affect included files or clang-tidy
-				reducedCFlags = config.TidyReduceCFlags(reducedCFlags)
 			}
 
-			sharedCFlags := shareFlags("cFlags", reducedCFlags)
+			sharedCFlags := shareFlags("cFlags", moduleFlags)
 			srcRelPath := srcFile.Rel()
 
 			// Add the .tidy rule
diff --git a/cc/cc.go b/cc/cc.go
index 814a66c..e215438 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -24,6 +24,7 @@
 	"strconv"
 	"strings"
 
+	"android/soong/testing"
 	"android/soong/ui/metrics/bp2build_metrics_proto"
 
 	"github.com/google/blueprint"
@@ -862,9 +863,10 @@
 	Properties       BaseProperties
 
 	// initialize before calling Init
-	hod       android.HostOrDeviceSupported
-	multilib  android.Multilib
-	bazelable bool
+	hod        android.HostOrDeviceSupported
+	multilib   android.Multilib
+	bazelable  bool
+	testModule bool
 
 	// Allowable SdkMemberTypes of this module type.
 	sdkMemberTypes []android.SdkMemberType
@@ -2329,6 +2331,9 @@
 			}
 		}
 	}
+	if c.testModule {
+		ctx.SetProvider(testing.TestModuleProviderKey, testing.TestModuleProviderData{})
+	}
 
 	c.maybeInstall(ctx, apexInfo)
 }
diff --git a/cc/config/tidy.go b/cc/config/tidy.go
index efa4549..b40557a 100644
--- a/cc/config/tidy.go
+++ b/cc/config/tidy.go
@@ -16,7 +16,6 @@
 
 import (
 	"android/soong/android"
-	"regexp"
 	"strings"
 )
 
@@ -281,11 +280,3 @@
 	}
 	return flags
 }
-
-var (
-	removedCFlags = regexp.MustCompile(" -fsanitize=[^ ]*memtag-[^ ]* ")
-)
-
-func TidyReduceCFlags(flags string) string {
-	return removedCFlags.ReplaceAllString(flags, " ")
-}
diff --git a/cc/fuzz.go b/cc/fuzz.go
index df9f21a..8fc4898 100644
--- a/cc/fuzz.go
+++ b/cc/fuzz.go
@@ -96,6 +96,7 @@
 // your device, or $ANDROID_PRODUCT_OUT/data/fuzz in your build tree.
 func LibFuzzFactory() android.Module {
 	module := NewFuzzer(android.HostAndDeviceSupported)
+	module.testModule = true
 	return module.Init()
 }
 
diff --git a/cc/lto.go b/cc/lto.go
index ad1a1b1..30d7b757 100644
--- a/cc/lto.go
+++ b/cc/lto.go
@@ -150,7 +150,6 @@
 		if !ctx.Config().IsEnvFalse("THINLTO_USE_MLGO") {
 			// Register allocation MLGO flags for ARM64.
 			if ctx.Arch().ArchType == android.Arm64 {
-				ltoCFlags = append(ltoCFlags, "-mllvm -regalloc-enable-advisor=release")
 				ltoLdFlags = append(ltoLdFlags, "-Wl,-mllvm,-regalloc-enable-advisor=release")
 			}
 			// Flags for training MLGO model.
diff --git a/cc/test.go b/cc/test.go
index 5b778dc..a4224c3 100644
--- a/cc/test.go
+++ b/cc/test.go
@@ -158,6 +158,7 @@
 // binary.
 func BenchmarkFactory() android.Module {
 	module := NewBenchmark(android.HostAndDeviceSupported)
+	module.testModule = true
 	return module.Init()
 }
 
@@ -489,6 +490,7 @@
 	module, binary := newBinary(hod, bazelable)
 	module.bazelable = bazelable
 	module.multilib = android.MultilibBoth
+	module.testModule = true
 	binary.baseInstaller = NewTestInstaller()
 
 	test := &testBinary{
diff --git a/genrule/allowlists.go b/genrule/allowlists.go
index c429730..d6620bc 100644
--- a/genrule/allowlists.go
+++ b/genrule/allowlists.go
@@ -27,26 +27,9 @@
 	SandboxingDenyModuleList = []string{
 		// go/keep-sorted start
 		"CtsApkVerityTestDebugFiles",
-		"MultiDexLegacyTestApp_genrule",
 		"ScriptGroupTest-rscript",
-		"TracingVMProtoStub_cc",
-		"TracingVMProtoStub_h",
-		"VehicleServerProtoStub_cc",
-		"VehicleServerProtoStub_cc@2.0-grpc-trout",
-		"VehicleServerProtoStub_cc@default-grpc",
-		"VehicleServerProtoStub_h",
-		"VehicleServerProtoStub_h@2.0-grpc-trout",
-		"VehicleServerProtoStub_h@default-grpc",
 		"aidl-golden-test-build-hook-gen",
 		"aidl_camera_build_version",
-		"android-cts-verifier",
-		"android-support-multidex-instrumentation-version",
-		"android-support-multidex-version",
-		"angle_commit_id",
-		"atest_integration_fake_src",
-		"awkgram.tab.h",
-		"c2hal_test_genc++",
-		"c2hal_test_genc++_headers",
 		"camera-its",
 		"checkIn-service-stub-lite",
 		"chre_atoms_log.h",
@@ -55,24 +38,16 @@
 		"cronet_aml_base_android_runtime_unchecked_jni_headers",
 		"cronet_aml_base_android_runtime_unchecked_jni_headers__testing",
 		"deqp_spvtools_update_build_version",
-		"emp_ematch.yacc.c",
-		"emp_ematch.yacc.h",
-		"fdt_test_tree_empty_memory_range_dtb",
-		"fdt_test_tree_multiple_memory_ranges_dtb",
-		"fdt_test_tree_one_memory_range_dtb",
 		"gen_corrupt_rebootless_apex",
 		"gen_key_mismatch_capex",
 		"libbssl_sys_src_nostd",
 		"libc_musl_sysroot_bits",
-		"libchrome-crypto-include",
-		"libchrome-include",
 		"libcore-non-cts-tests-txt",
 		"pvmfw_fdt_template_rs",
 		"seller-frontend-service-stub-lite",
 		"swiftshader_spvtools_update_build_version",
 		"ue_unittest_erofs_imgs",
 		"vm-tests-tf-lib",
-		"vndk_abi_dump_zip",
 		// go/keep-sorted end
 	}
 
diff --git a/java/Android.bp b/java/Android.bp
index 29c0957..cf96871 100644
--- a/java/Android.bp
+++ b/java/Android.bp
@@ -113,6 +113,7 @@
         "sdk_library_test.go",
         "system_modules_test.go",
         "systemserver_classpath_fragment_test.go",
+        "test_spec_test.go",
     ],
     pluginFor: ["soong_build"],
 }
diff --git a/java/app.go b/java/app.go
index 9b7f4c4..6d7411d 100755
--- a/java/app.go
+++ b/java/app.go
@@ -869,7 +869,7 @@
 			ctx.InstallFile(allowlistInstallPath, allowlistInstallFilename, a.privAppAllowlist.Path())
 		}
 
-		var extraInstalledPaths android.Paths
+		var extraInstalledPaths android.InstallPaths
 		for _, extra := range a.extraOutputFiles {
 			installed := ctx.InstallFile(a.installDir, extra.Base(), extra)
 			extraInstalledPaths = append(extraInstalledPaths, installed)
diff --git a/java/java.go b/java/java.go
index 500ae37..bb9357c 100644
--- a/java/java.go
+++ b/java/java.go
@@ -641,7 +641,7 @@
 
 	exportedProguardFlagFiles android.Paths
 
-	InstallMixin func(ctx android.ModuleContext, installPath android.Path) (extraInstallDeps android.Paths)
+	InstallMixin func(ctx android.ModuleContext, installPath android.Path) (extraInstallDeps android.InstallPaths)
 }
 
 var _ android.ApexModule = (*Library)(nil)
@@ -722,7 +722,7 @@
 
 	exclusivelyForApex := !apexInfo.IsForPlatform()
 	if (Bool(j.properties.Installable) || ctx.Host()) && !exclusivelyForApex {
-		var extraInstallDeps android.Paths
+		var extraInstallDeps android.InstallPaths
 		if j.InstallMixin != nil {
 			extraInstallDeps = j.InstallMixin(ctx, j.outputFile)
 		}
diff --git a/java/resourceshrinker.go b/java/resourceshrinker.go
index bf1b04d..af13aa3 100644
--- a/java/resourceshrinker.go
+++ b/java/resourceshrinker.go
@@ -23,7 +23,8 @@
 var shrinkResources = pctx.AndroidStaticRule("shrinkResources",
 	blueprint.RuleParams{
 		// Note that we suppress stdout to avoid successful log confirmations.
-		Command:     `${config.ResourceShrinkerCmd} --output $out --input $in --raw_resources $raw_resources >/dev/null`,
+		Command: `RESOURCESHRINKER_OPTS=-Dcom.android.tools.r8.dexContainerExperiment ` +
+			`${config.ResourceShrinkerCmd} --output $out --input $in --raw_resources $raw_resources >/dev/null`,
 		CommandDeps: []string{"${config.ResourceShrinkerCmd}"},
 	}, "raw_resources")
 
diff --git a/java/robolectric.go b/java/robolectric.go
index a8e6bfa..a66b310 100644
--- a/java/robolectric.go
+++ b/java/robolectric.go
@@ -226,7 +226,7 @@
 	}
 
 	installPath := android.PathForModuleInstall(ctx, r.BaseModuleName())
-	var installDeps android.Paths
+	var installDeps android.InstallPaths
 
 	if r.manifest != nil {
 		r.data = append(r.data, r.manifest)
diff --git a/java/test_spec_test.go b/java/test_spec_test.go
new file mode 100644
index 0000000..39aff4c
--- /dev/null
+++ b/java/test_spec_test.go
@@ -0,0 +1,133 @@
+package java
+
+import (
+	"strings"
+	"testing"
+
+	"android/soong/android"
+	soongTesting "android/soong/testing"
+	"android/soong/testing/test_spec_proto"
+	"google.golang.org/protobuf/proto"
+)
+
+func TestTestSpec(t *testing.T) {
+	bp := `test_spec {
+		name: "module-name",
+		teamId: "12345",
+		tests: [
+			"java-test-module-name-one",
+			"java-test-module-name-two"
+		]
+	}
+
+	java_test {
+		name: "java-test-module-name-one",
+	}
+
+	java_test {
+		name: "java-test-module-name-two",
+	}`
+	result := runTest(t, android.FixtureExpectsNoErrors, bp)
+
+	module := result.ModuleForTests(
+		"module-name", "",
+	).Module().(*soongTesting.TestSpecModule)
+
+	// Check that the provider has the right contents
+	data := result.ModuleProvider(
+		module, soongTesting.TestSpecProviderKey,
+	).(soongTesting.TestSpecProviderData)
+	if !strings.HasSuffix(
+		data.IntermediatePath.String(), "/intermediateTestSpecMetadata.pb",
+	) {
+		t.Errorf(
+			"Missing intermediates path in provider: %s",
+			data.IntermediatePath.String(),
+		)
+	}
+
+	buildParamsSlice := module.BuildParamsForTests()
+	var metadata = ""
+	for _, params := range buildParamsSlice {
+		if params.Rule.String() == "android/soong/android.writeFile" {
+			metadata = params.Args["content"]
+		}
+	}
+
+	metadataList := make([]*test_spec_proto.TestSpec_OwnershipMetadata, 0, 2)
+	teamId := "12345"
+	bpFilePath := "Android.bp"
+	targetNames := []string{
+		"java-test-module-name-one", "java-test-module-name-two",
+	}
+
+	for _, test := range targetNames {
+		targetName := test
+		metadata := test_spec_proto.TestSpec_OwnershipMetadata{
+			TrendyTeamId: &teamId,
+			TargetName:   &targetName,
+			Path:         &bpFilePath,
+		}
+		metadataList = append(metadataList, &metadata)
+	}
+	testSpecMetadata := test_spec_proto.TestSpec{OwnershipMetadataList: metadataList}
+	protoData, _ := proto.Marshal(&testSpecMetadata)
+	rawData := string(protoData)
+	formattedData := strings.ReplaceAll(rawData, "\n", "\\n")
+	expectedMetadata := "'" + formattedData + "\\n'"
+
+	if metadata != expectedMetadata {
+		t.Errorf(
+			"Retrieved metadata: %s is not equal to expectedMetadata: %s", metadata,
+			expectedMetadata,
+		)
+	}
+
+	// Tests for all_test_spec singleton.
+	singleton := result.SingletonForTests("all_test_specs")
+	rule := singleton.Rule("all_test_specs_rule")
+	prebuiltOs := result.Config.PrebuiltOS()
+	expectedCmd := "out/soong/host/" + prebuiltOs + "/bin/metadata -rule test_spec -inputFile out/soong/all_test_spec_paths.rsp -outputFile out/soong/ownership/all_test_specs.pb"
+	expectedOutputFile := "out/soong/ownership/all_test_specs.pb"
+	expectedInputFile := "out/soong/.intermediates/module-name/intermediateTestSpecMetadata.pb"
+	if !strings.Contains(
+		strings.TrimSpace(rule.Output.String()),
+		expectedOutputFile,
+	) {
+		t.Errorf(
+			"Retrieved singletonOutputFile: %s is not equal to expectedSingletonOutputFile: %s",
+			rule.Output.String(), expectedOutputFile,
+		)
+	}
+
+	if !strings.Contains(
+		strings.TrimSpace(rule.Inputs[0].String()),
+		expectedInputFile,
+	) {
+		t.Errorf(
+			"Retrieved singletonInputFile: %s is not equal to expectedSingletonInputFile: %s",
+			rule.Inputs[0].String(), expectedInputFile,
+		)
+	}
+
+	if !strings.Contains(
+		strings.TrimSpace(rule.RuleParams.Command),
+		expectedCmd,
+	) {
+		t.Errorf(
+			"Retrieved cmd: %s is not equal to expectedCmd: %s",
+			rule.RuleParams.Command, expectedCmd,
+		)
+	}
+}
+
+func runTest(
+	t *testing.T, errorHandler android.FixtureErrorHandler, bp string,
+) *android.TestResult {
+	return android.GroupFixturePreparers(
+		soongTesting.PrepareForTestWithTestSpecBuildComponents,
+		PrepareForIntegrationTestWithJava,
+	).
+		ExtendWithErrorHandler(errorHandler).
+		RunTestWithBp(t, bp)
+}
diff --git a/java/tradefed.go b/java/tradefed.go
index ebbdec1..349b327 100644
--- a/java/tradefed.go
+++ b/java/tradefed.go
@@ -30,8 +30,8 @@
 	return module
 }
 
-func tradefedJavaLibraryInstall(ctx android.ModuleContext, path android.Path) android.Paths {
+func tradefedJavaLibraryInstall(ctx android.ModuleContext, path android.Path) android.InstallPaths {
 	installedPath := ctx.InstallFile(android.PathForModuleInstall(ctx, "tradefed"),
 		ctx.ModuleName()+".jar", path)
-	return android.Paths{installedPath}
+	return android.InstallPaths{installedPath}
 }
diff --git a/rust/Android.bp b/rust/Android.bp
index b01a94a..c5b2000 100644
--- a/rust/Android.bp
+++ b/rust/Android.bp
@@ -12,6 +12,7 @@
         "soong-cc",
         "soong-rust-config",
         "soong-snapshot",
+        "soong-testing",
     ],
     srcs: [
         "afdo.go",
diff --git a/rust/binary.go b/rust/binary.go
index 860dc94..5e7e922 100644
--- a/rust/binary.go
+++ b/rust/binary.go
@@ -137,12 +137,7 @@
 	fileName := binary.getStem(ctx) + ctx.toolchain().ExecutableSuffix()
 	outputFile := android.PathForModuleOut(ctx, fileName)
 	ret := buildOutput{outputFile: outputFile}
-	var crateRootPath android.Path
-	if binary.baseCompiler.Properties.Crate_root == nil {
-		crateRootPath, _ = srcPathFromModuleSrcs(ctx, binary.baseCompiler.Properties.Srcs)
-	} else {
-		crateRootPath = android.PathForModuleSrc(ctx, *binary.baseCompiler.Properties.Crate_root)
-	}
+	crateRootPath := crateRootPath(ctx, binary)
 
 	flags.RustFlags = append(flags.RustFlags, deps.depFlags...)
 	flags.LinkFlags = append(flags.LinkFlags, deps.depLinkFlags...)
diff --git a/rust/builder.go b/rust/builder.go
index 162d1aa..c855cfb 100644
--- a/rust/builder.go
+++ b/rust/builder.go
@@ -196,7 +196,7 @@
 	}
 
 	if len(deps.SrcDeps) > 0 {
-		moduleGenDir := ctx.RustModule().compiler.CargoOutDir()
+		moduleGenDir := ctx.RustModule().compiler.cargoOutDir()
 		// We must calculate an absolute path for OUT_DIR since Rust's include! macro (which normally consumes this)
 		// assumes that paths are relative to the source file.
 		var outDirPrefix string
@@ -215,13 +215,13 @@
 
 	envVars = append(envVars, "ANDROID_RUST_VERSION="+config.GetRustVersion(ctx))
 
-	if ctx.RustModule().compiler.CargoEnvCompat() {
+	if ctx.RustModule().compiler.cargoEnvCompat() {
 		if bin, ok := ctx.RustModule().compiler.(*binaryDecorator); ok {
 			envVars = append(envVars, "CARGO_BIN_NAME="+bin.getStem(ctx))
 		}
 		envVars = append(envVars, "CARGO_CRATE_NAME="+ctx.RustModule().CrateName())
 		envVars = append(envVars, "CARGO_PKG_NAME="+ctx.RustModule().CrateName())
-		pkgVersion := ctx.RustModule().compiler.CargoPkgVersion()
+		pkgVersion := ctx.RustModule().compiler.cargoPkgVersion()
 		if pkgVersion != "" {
 			envVars = append(envVars, "CARGO_PKG_VERSION="+pkgVersion)
 
@@ -327,7 +327,7 @@
 	orderOnly = append(orderOnly, deps.SharedLibs...)
 
 	if len(deps.SrcDeps) > 0 {
-		moduleGenDir := ctx.RustModule().compiler.CargoOutDir()
+		moduleGenDir := ctx.RustModule().compiler.cargoOutDir()
 		var outputs android.WritablePaths
 
 		for _, genSrc := range deps.SrcDeps {
diff --git a/rust/compiler.go b/rust/compiler.go
index 4c7961d..d453a5d 100644
--- a/rust/compiler.go
+++ b/rust/compiler.go
@@ -16,6 +16,7 @@
 
 import (
 	"android/soong/cc"
+	"errors"
 	"fmt"
 	"path/filepath"
 	"strings"
@@ -34,6 +35,48 @@
 	DylibLinkage
 )
 
+type compiler interface {
+	initialize(ctx ModuleContext)
+	compilerFlags(ctx ModuleContext, flags Flags) Flags
+	cfgFlags(ctx ModuleContext, flags Flags) Flags
+	featureFlags(ctx ModuleContext, flags Flags) Flags
+	compilerProps() []interface{}
+	compile(ctx ModuleContext, flags Flags, deps PathDeps) buildOutput
+	compilerDeps(ctx DepsContext, deps Deps) Deps
+	crateName() string
+	edition() string
+	features() []string
+	rustdoc(ctx ModuleContext, flags Flags, deps PathDeps) android.OptionalPath
+
+	// Output directory in which source-generated code from dependencies is
+	// copied. This is equivalent to Cargo's OUT_DIR variable.
+	cargoOutDir() android.OptionalPath
+
+	// cargoPkgVersion returns the value of the Cargo_pkg_version property.
+	cargoPkgVersion() string
+
+	// cargoEnvCompat returns whether Cargo environment variables should be used.
+	cargoEnvCompat() bool
+
+	inData() bool
+	install(ctx ModuleContext)
+	relativeInstallPath() string
+	everInstallable() bool
+
+	nativeCoverage() bool
+
+	Disabled() bool
+	SetDisabled()
+
+	stdLinkage(ctx *depsContext) RustLinkage
+	noStdlibs() bool
+
+	unstrippedOutputFilePath() android.Path
+	strippedOutputFilePath() android.OptionalPath
+
+	checkedCrateRootPath() (android.Path, error)
+}
+
 func (compiler *baseCompiler) edition() string {
 	return proptools.StringDefault(compiler.Properties.Edition, config.DefaultEdition)
 }
@@ -204,7 +247,16 @@
 
 	// If a crate has a source-generated dependency, a copy of the source file
 	// will be available in cargoOutDir (equivalent to Cargo OUT_DIR).
-	cargoOutDir android.ModuleOutPath
+	// This is stored internally because it may not be available during
+	// singleton-generation passes like rustdoc/rust_project.json, but should
+	// be stashed during initial generation.
+	cachedCargoOutDir android.ModuleOutPath
+	// Calculated crate root cached internally because ModuleContext is not
+	// available to singleton targets like rustdoc/rust_project.json
+	cachedCrateRootPath android.Path
+	// If cachedCrateRootPath is nil after initialization, this will contain
+	// an explanation of why
+	cachedCrateRootError error
 }
 
 func (compiler *baseCompiler) Disabled() bool {
@@ -257,9 +309,13 @@
 	return flags
 }
 
+func (compiler *baseCompiler) features() []string {
+	return compiler.Properties.Features
+}
+
 func (compiler *baseCompiler) featuresToFlags() []string {
 	flags := []string{}
-	for _, feature := range compiler.Properties.Features {
+	for _, feature := range compiler.features() {
 		flags = append(flags, "--cfg 'feature=\""+feature+"\"'")
 	}
 
@@ -355,18 +411,24 @@
 }
 
 func (compiler *baseCompiler) initialize(ctx ModuleContext) {
-	compiler.cargoOutDir = android.PathForModuleOut(ctx, genSubDir)
+	compiler.cachedCargoOutDir = android.PathForModuleOut(ctx, genSubDir)
+	if compiler.Properties.Crate_root == nil {
+		compiler.cachedCrateRootPath, compiler.cachedCrateRootError = srcPathFromModuleSrcs(ctx, compiler.Properties.Srcs)
+	} else {
+		compiler.cachedCrateRootPath = android.PathForModuleSrc(ctx, *compiler.Properties.Crate_root)
+		compiler.cachedCrateRootError = nil
+	}
 }
 
-func (compiler *baseCompiler) CargoOutDir() android.OptionalPath {
-	return android.OptionalPathForPath(compiler.cargoOutDir)
+func (compiler *baseCompiler) cargoOutDir() android.OptionalPath {
+	return android.OptionalPathForPath(compiler.cachedCargoOutDir)
 }
 
-func (compiler *baseCompiler) CargoEnvCompat() bool {
+func (compiler *baseCompiler) cargoEnvCompat() bool {
 	return Bool(compiler.Properties.Cargo_env_compat)
 }
 
-func (compiler *baseCompiler) CargoPkgVersion() string {
+func (compiler *baseCompiler) cargoPkgVersion() string {
 	return String(compiler.Properties.Cargo_pkg_version)
 }
 
@@ -496,12 +558,20 @@
 	return String(compiler.Properties.Relative_install_path)
 }
 
-// Returns the Path for the main source file along with Paths for generated source files from modules listed in srcs.
-func srcPathFromModuleSrcs(ctx ModuleContext, srcs []string) (android.Path, android.Paths) {
-	if len(srcs) == 0 {
-		ctx.PropertyErrorf("srcs", "srcs must not be empty")
-	}
+func (compiler *baseCompiler) checkedCrateRootPath() (android.Path, error) {
+	return compiler.cachedCrateRootPath, compiler.cachedCrateRootError
+}
 
+func crateRootPath(ctx ModuleContext, compiler compiler) android.Path {
+	root, err := compiler.checkedCrateRootPath()
+	if err != nil {
+		ctx.PropertyErrorf("srcs", err.Error())
+	}
+	return root
+}
+
+// Returns the Path for the main source file along with Paths for generated source files from modules listed in srcs.
+func srcPathFromModuleSrcs(ctx ModuleContext, srcs []string) (android.Path, error) {
 	// The srcs can contain strings with prefix ":".
 	// They are dependent modules of this module, with android.SourceDepTag.
 	// They are not the main source file compiled by rustc.
@@ -514,19 +584,22 @@
 		}
 	}
 	if numSrcs > 1 {
-		ctx.PropertyErrorf("srcs", incorrectSourcesError)
+		return nil, errors.New(incorrectSourcesError)
 	}
 
 	// If a main source file is not provided we expect only a single SourceProvider module to be defined
 	// within srcs, with the expectation that the first source it provides is the entry point.
 	if srcIndex != 0 {
-		ctx.PropertyErrorf("srcs", "main source file must be the first in srcs")
+		return nil, errors.New("main source file must be the first in srcs")
 	} else if numSrcs > 1 {
-		ctx.PropertyErrorf("srcs", "only a single generated source module can be defined without a main source file.")
+		return nil, errors.New("only a single generated source module can be defined without a main source file.")
 	}
 
 	// TODO: b/297264540 - once all modules are sandboxed, we need to select the proper
 	// entry point file from Srcs rather than taking the first one
 	paths := android.PathsForModuleSrc(ctx, srcs)
-	return paths[srcIndex], paths[1:]
+	if len(paths) == 0 {
+		return nil, errors.New("srcs must not be empty")
+	}
+	return paths[srcIndex], nil
 }
diff --git a/rust/compiler_test.go b/rust/compiler_test.go
index ec6829a..89f4d1a 100644
--- a/rust/compiler_test.go
+++ b/rust/compiler_test.go
@@ -67,6 +67,7 @@
 func TestEnforceSingleSourceFile(t *testing.T) {
 
 	singleSrcError := "srcs can only contain one path for a rust file and source providers prefixed by \":\""
+	prebuiltSingleSrcError := "prebuilt libraries can only have one entry in srcs"
 
 	// Test libraries
 	testRustError(t, singleSrcError, `
@@ -90,7 +91,7 @@
 		}`)
 
 	// Test prebuilts
-	testRustError(t, singleSrcError, `
+	testRustError(t, prebuiltSingleSrcError, `
 		rust_prebuilt_dylib {
 			name: "foo-bar-prebuilt",
 			srcs: ["liby.so", "libz.so"],
diff --git a/rust/library.go b/rust/library.go
index 18bf0a0..c0ff741 100644
--- a/rust/library.go
+++ b/rust/library.go
@@ -15,6 +15,7 @@
 package rust
 
 import (
+	"errors"
 	"fmt"
 	"regexp"
 	"strings"
@@ -489,7 +490,7 @@
 	var outputFile android.ModuleOutPath
 	var ret buildOutput
 	var fileName string
-	crateRootPath := library.crateRootPath(ctx, deps)
+	crateRootPath := crateRootPath(ctx, library)
 
 	if library.sourceProvider != nil {
 		deps.srcProviderFiles = append(deps.srcProviderFiles, library.sourceProvider.Srcs()...)
@@ -584,15 +585,16 @@
 	return ret
 }
 
-func (library *libraryDecorator) crateRootPath(ctx ModuleContext, _ PathDeps) android.Path {
+func (library *libraryDecorator) checkedCrateRootPath() (android.Path, error) {
 	if library.sourceProvider != nil {
+		srcs := library.sourceProvider.Srcs()
+		if len(srcs) == 0 {
+			return nil, errors.New("Source provider generated 0 sources")
+		}
 		// Assume the first source from the source provider is the library entry point.
-		return library.sourceProvider.Srcs()[0]
-	} else if library.baseCompiler.Properties.Crate_root == nil {
-		path, _ := srcPathFromModuleSrcs(ctx, library.baseCompiler.Properties.Srcs)
-		return path
+		return srcs[0], nil
 	} else {
-		return android.PathForModuleSrc(ctx, *library.baseCompiler.Properties.Crate_root)
+		return library.baseCompiler.checkedCrateRootPath()
 	}
 }
 
@@ -607,7 +609,7 @@
 		return android.OptionalPath{}
 	}
 
-	return android.OptionalPathForPath(Rustdoc(ctx, library.crateRootPath(ctx, deps),
+	return android.OptionalPathForPath(Rustdoc(ctx, crateRootPath(ctx, library),
 		deps, flags))
 }
 
diff --git a/rust/prebuilt.go b/rust/prebuilt.go
index fe9d0b5..e35e510 100644
--- a/rust/prebuilt.go
+++ b/rust/prebuilt.go
@@ -76,6 +76,17 @@
 var _ exportedFlagsProducer = (*prebuiltProcMacroDecorator)(nil)
 var _ rustPrebuilt = (*prebuiltProcMacroDecorator)(nil)
 
+func prebuiltPath(ctx ModuleContext, prebuilt rustPrebuilt) android.Path {
+	srcs := android.PathsForModuleSrc(ctx, prebuilt.prebuiltSrcs())
+	if len(srcs) == 0 {
+		ctx.PropertyErrorf("srcs", "srcs must not be empty")
+	}
+	if len(srcs) > 1 {
+		ctx.PropertyErrorf("srcs", "prebuilt libraries can only have one entry in srcs (the prebuilt path)")
+	}
+	return srcs[0]
+}
+
 func PrebuiltLibraryFactory() android.Module {
 	module, _ := NewPrebuiltLibrary(android.HostAndDeviceSupported)
 	return module.Init()
@@ -148,11 +159,7 @@
 func (prebuilt *prebuiltLibraryDecorator) compile(ctx ModuleContext, flags Flags, deps PathDeps) buildOutput {
 	prebuilt.flagExporter.exportLinkDirs(android.PathsForModuleSrc(ctx, prebuilt.Properties.Link_dirs).Strings()...)
 	prebuilt.flagExporter.setProvider(ctx)
-
-	srcPath, paths := srcPathFromModuleSrcs(ctx, prebuilt.prebuiltSrcs())
-	if len(paths) > 0 {
-		ctx.PropertyErrorf("srcs", "prebuilt libraries can only have one entry in srcs (the prebuilt path)")
-	}
+	srcPath := prebuiltPath(ctx, prebuilt)
 	prebuilt.baseCompiler.unstrippedOutputFile = srcPath
 	return buildOutput{outputFile: srcPath}
 }
@@ -205,11 +212,7 @@
 func (prebuilt *prebuiltProcMacroDecorator) compile(ctx ModuleContext, flags Flags, deps PathDeps) buildOutput {
 	prebuilt.flagExporter.exportLinkDirs(android.PathsForModuleSrc(ctx, prebuilt.Properties.Link_dirs).Strings()...)
 	prebuilt.flagExporter.setProvider(ctx)
-
-	srcPath, paths := srcPathFromModuleSrcs(ctx, prebuilt.prebuiltSrcs())
-	if len(paths) > 0 {
-		ctx.PropertyErrorf("srcs", "prebuilt libraries can only have one entry in srcs (the prebuilt path)")
-	}
+	srcPath := prebuiltPath(ctx, prebuilt)
 	prebuilt.baseCompiler.unstrippedOutputFile = srcPath
 	return buildOutput{outputFile: srcPath}
 }
diff --git a/rust/proc_macro.go b/rust/proc_macro.go
index b93b24f..c18d5ec 100644
--- a/rust/proc_macro.go
+++ b/rust/proc_macro.go
@@ -78,8 +78,7 @@
 func (procMacro *procMacroDecorator) compile(ctx ModuleContext, flags Flags, deps PathDeps) buildOutput {
 	fileName := procMacro.getStem(ctx) + ctx.toolchain().ProcMacroSuffix()
 	outputFile := android.PathForModuleOut(ctx, fileName)
-
-	srcPath, _ := srcPathFromModuleSrcs(ctx, procMacro.baseCompiler.Properties.Srcs)
+	srcPath := crateRootPath(ctx, procMacro)
 	ret := TransformSrctoProcMacro(ctx, srcPath, deps, flags, outputFile)
 	procMacro.baseCompiler.unstrippedOutputFile = outputFile
 	return ret
diff --git a/rust/project_json.go b/rust/project_json.go
index 40aa7c7..83c16ca 100644
--- a/rust/project_json.go
+++ b/rust/project_json.go
@@ -17,7 +17,6 @@
 import (
 	"encoding/json"
 	"fmt"
-	"path"
 
 	"android/soong/android"
 )
@@ -60,8 +59,9 @@
 
 // crateInfo is used during the processing to keep track of the known crates.
 type crateInfo struct {
-	Idx  int            // Index of the crate in rustProjectJson.Crates slice.
-	Deps map[string]int // The keys are the module names and not the crate names.
+	Idx    int            // Index of the crate in rustProjectJson.Crates slice.
+	Deps   map[string]int // The keys are the module names and not the crate names.
+	Device bool           // True if the crate at idx was a device crate
 }
 
 type projectGeneratorSingleton struct {
@@ -77,85 +77,6 @@
 	android.RegisterParallelSingletonType("rust_project_generator", rustProjectGeneratorSingleton)
 }
 
-// sourceProviderVariantSource returns the path to the source file if this
-// module variant should be used as a priority.
-//
-// SourceProvider modules may have multiple variants considered as source
-// (e.g., x86_64 and armv8). For a module available on device, use the source
-// generated for the target. For a host-only module, use the source generated
-// for the host.
-func sourceProviderVariantSource(ctx android.SingletonContext, rModule *Module) (string, bool) {
-	rustLib, ok := rModule.compiler.(*libraryDecorator)
-	if !ok {
-		return "", false
-	}
-	if rustLib.source() {
-		switch rModule.hod {
-		case android.HostSupported, android.HostSupportedNoCross:
-			if rModule.Target().String() == ctx.Config().BuildOSTarget.String() {
-				src := rustLib.sourceProvider.Srcs()[0]
-				return src.String(), true
-			}
-		default:
-			if rModule.Target().String() == ctx.Config().AndroidFirstDeviceTarget.String() {
-				src := rustLib.sourceProvider.Srcs()[0]
-				return src.String(), true
-			}
-		}
-	}
-	return "", false
-}
-
-// sourceProviderSource finds the main source file of a source-provider crate.
-func sourceProviderSource(ctx android.SingletonContext, rModule *Module) (string, bool) {
-	rustLib, ok := rModule.compiler.(*libraryDecorator)
-	if !ok {
-		return "", false
-	}
-	if rustLib.source() {
-		// This is a source-variant, check if we are the right variant
-		// depending on the module configuration.
-		if src, ok := sourceProviderVariantSource(ctx, rModule); ok {
-			return src, true
-		}
-	}
-	foundSource := false
-	sourceSrc := ""
-	// Find the variant with the source and return its.
-	ctx.VisitAllModuleVariants(rModule, func(variant android.Module) {
-		if foundSource {
-			return
-		}
-		// All variants of a source provider library are libraries.
-		rVariant, _ := variant.(*Module)
-		variantLib, _ := rVariant.compiler.(*libraryDecorator)
-		if variantLib.source() {
-			sourceSrc, ok = sourceProviderVariantSource(ctx, rVariant)
-			if ok {
-				foundSource = true
-			}
-		}
-	})
-	if !foundSource {
-		ctx.Errorf("No valid source for source provider found: %v\n", rModule)
-	}
-	return sourceSrc, foundSource
-}
-
-// crateSource finds the main source file (.rs) for a crate.
-func crateSource(ctx android.SingletonContext, rModule *Module, comp *baseCompiler) (string, bool) {
-	// Basic libraries, executables and tests.
-	srcs := comp.Properties.Srcs
-	if len(srcs) != 0 {
-		return path.Join(ctx.ModuleDir(rModule), srcs[0]), true
-	}
-	// SourceProvider libraries.
-	if rModule.sourceProvider != nil {
-		return sourceProviderSource(ctx, rModule)
-	}
-	return "", false
-}
-
 // mergeDependencies visits all the dependencies for module and updates crate and deps
 // with any new dependency.
 func (singleton *projectGeneratorSingleton) mergeDependencies(ctx android.SingletonContext,
@@ -167,7 +88,7 @@
 			return
 		}
 		// Skip unsupported modules.
-		rChild, compChild, ok := isModuleSupported(ctx, child)
+		rChild, ok := isModuleSupported(ctx, child)
 		if !ok {
 			return
 		}
@@ -175,7 +96,7 @@
 		var childId int
 		cInfo, known := singleton.knownCrates[rChild.Name()]
 		if !known {
-			childId, ok = singleton.addCrate(ctx, rChild, compChild)
+			childId, ok = singleton.addCrate(ctx, rChild, make(map[string]int))
 			if !ok {
 				return
 			}
@@ -191,41 +112,22 @@
 	})
 }
 
-// isModuleSupported returns the RustModule and baseCompiler if the module
+// isModuleSupported returns the RustModule if the module
 // should be considered for inclusion in rust-project.json.
-func isModuleSupported(ctx android.SingletonContext, module android.Module) (*Module, *baseCompiler, bool) {
+func isModuleSupported(ctx android.SingletonContext, module android.Module) (*Module, bool) {
 	rModule, ok := module.(*Module)
 	if !ok {
-		return nil, nil, false
+		return nil, false
 	}
-	if rModule.compiler == nil {
-		return nil, nil, false
-	}
-	var comp *baseCompiler
-	switch c := rModule.compiler.(type) {
-	case *libraryDecorator:
-		comp = c.baseCompiler
-	case *binaryDecorator:
-		comp = c.baseCompiler
-	case *testDecorator:
-		comp = c.binaryDecorator.baseCompiler
-	case *procMacroDecorator:
-		comp = c.baseCompiler
-	case *toolchainLibraryDecorator:
-		comp = c.baseCompiler
-	default:
-		return nil, nil, false
-	}
-	return rModule, comp, true
+	return rModule, true
 }
 
 // addCrate adds a crate to singleton.project.Crates ensuring that required
 // dependencies are also added. It returns the index of the new crate in
 // singleton.project.Crates
-func (singleton *projectGeneratorSingleton) addCrate(ctx android.SingletonContext, rModule *Module, comp *baseCompiler) (int, bool) {
-	rootModule, ok := crateSource(ctx, rModule, comp)
-	if !ok {
-		ctx.Errorf("Unable to find source for valid module: %v", rModule)
+func (singleton *projectGeneratorSingleton) addCrate(ctx android.SingletonContext, rModule *Module, deps map[string]int) (int, bool) {
+	rootModule, err := rModule.compiler.checkedCrateRootPath()
+	if err != nil {
 		return 0, false
 	}
 
@@ -233,28 +135,33 @@
 
 	crate := rustProjectCrate{
 		DisplayName: rModule.Name(),
-		RootModule:  rootModule,
-		Edition:     comp.edition(),
+		RootModule:  rootModule.String(),
+		Edition:     rModule.compiler.edition(),
 		Deps:        make([]rustProjectDep, 0),
 		Cfg:         make([]string, 0),
 		Env:         make(map[string]string),
 		ProcMacro:   procMacro,
 	}
 
-	if comp.CargoOutDir().Valid() {
-		crate.Env["OUT_DIR"] = comp.CargoOutDir().String()
+	if rModule.compiler.cargoOutDir().Valid() {
+		crate.Env["OUT_DIR"] = rModule.compiler.cargoOutDir().String()
 	}
 
-	for _, feature := range comp.Properties.Features {
+	for _, feature := range rModule.compiler.features() {
 		crate.Cfg = append(crate.Cfg, "feature=\""+feature+"\"")
 	}
 
-	deps := make(map[string]int)
 	singleton.mergeDependencies(ctx, rModule, &crate, deps)
 
-	idx := len(singleton.project.Crates)
-	singleton.knownCrates[rModule.Name()] = crateInfo{Idx: idx, Deps: deps}
-	singleton.project.Crates = append(singleton.project.Crates, crate)
+	var idx int
+	if cInfo, ok := singleton.knownCrates[rModule.Name()]; ok {
+		idx = cInfo.Idx
+		singleton.project.Crates[idx] = crate
+	} else {
+		idx = len(singleton.project.Crates)
+		singleton.project.Crates = append(singleton.project.Crates, crate)
+	}
+	singleton.knownCrates[rModule.Name()] = crateInfo{Idx: idx, Deps: deps, Device: rModule.Device()}
 	return idx, true
 }
 
@@ -262,18 +169,23 @@
 // It visits the dependencies of the module depth-first so the dependency ID can be added to the current module. If the
 // current module is already in singleton.knownCrates, its dependencies are merged.
 func (singleton *projectGeneratorSingleton) appendCrateAndDependencies(ctx android.SingletonContext, module android.Module) {
-	rModule, comp, ok := isModuleSupported(ctx, module)
+	rModule, ok := isModuleSupported(ctx, module)
 	if !ok {
 		return
 	}
 	// If we have seen this crate already; merge any new dependencies.
 	if cInfo, ok := singleton.knownCrates[module.Name()]; ok {
+		// If we have a new device variant, override the old one
+		if !cInfo.Device && rModule.Device() {
+			singleton.addCrate(ctx, rModule, cInfo.Deps)
+			return
+		}
 		crate := singleton.project.Crates[cInfo.Idx]
 		singleton.mergeDependencies(ctx, rModule, &crate, cInfo.Deps)
 		singleton.project.Crates[cInfo.Idx] = crate
 		return
 	}
-	singleton.addCrate(ctx, rModule, comp)
+	singleton.addCrate(ctx, rModule, make(map[string]int))
 }
 
 func (singleton *projectGeneratorSingleton) GenerateBuildActions(ctx android.SingletonContext) {
diff --git a/rust/rust.go b/rust/rust.go
index 19c5230..d4d33c7 100644
--- a/rust/rust.go
+++ b/rust/rust.go
@@ -20,6 +20,7 @@
 
 	"android/soong/bazel"
 	"android/soong/bloaty"
+	"android/soong/testing"
 	"android/soong/ui/metrics/bp2build_metrics_proto"
 
 	"github.com/google/blueprint"
@@ -144,8 +145,9 @@
 
 	Properties BaseProperties
 
-	hod      android.HostOrDeviceSupported
-	multilib android.Multilib
+	hod        android.HostOrDeviceSupported
+	multilib   android.Multilib
+	testModule bool
 
 	makeLinkType string
 
@@ -485,44 +487,6 @@
 	CrateName string
 }
 
-type compiler interface {
-	initialize(ctx ModuleContext)
-	compilerFlags(ctx ModuleContext, flags Flags) Flags
-	cfgFlags(ctx ModuleContext, flags Flags) Flags
-	featureFlags(ctx ModuleContext, flags Flags) Flags
-	compilerProps() []interface{}
-	compile(ctx ModuleContext, flags Flags, deps PathDeps) buildOutput
-	compilerDeps(ctx DepsContext, deps Deps) Deps
-	crateName() string
-	rustdoc(ctx ModuleContext, flags Flags, deps PathDeps) android.OptionalPath
-
-	// Output directory in which source-generated code from dependencies is
-	// copied. This is equivalent to Cargo's OUT_DIR variable.
-	CargoOutDir() android.OptionalPath
-
-	// CargoPkgVersion returns the value of the Cargo_pkg_version property.
-	CargoPkgVersion() string
-
-	// CargoEnvCompat returns whether Cargo environment variables should be used.
-	CargoEnvCompat() bool
-
-	inData() bool
-	install(ctx ModuleContext)
-	relativeInstallPath() string
-	everInstallable() bool
-
-	nativeCoverage() bool
-
-	Disabled() bool
-	SetDisabled()
-
-	stdLinkage(ctx *depsContext) RustLinkage
-	noStdlibs() bool
-
-	unstrippedOutputFilePath() android.Path
-	strippedOutputFilePath() android.OptionalPath
-}
-
 type exportedFlagsProducer interface {
 	exportLinkDirs(...string)
 	exportLinkObjects(...string)
@@ -1038,6 +1002,9 @@
 
 		ctx.Phony("rust", ctx.RustModule().OutputFile().Path())
 	}
+	if mod.testModule {
+		ctx.SetProvider(testing.TestModuleProviderKey, testing.TestModuleProviderData{})
+	}
 }
 
 func (mod *Module) deps(ctx DepsContext) Deps {
diff --git a/rust/test.go b/rust/test.go
index 4b5296e..7ffc367 100644
--- a/rust/test.go
+++ b/rust/test.go
@@ -222,11 +222,13 @@
 	// rustTestHostMultilib load hook to set MultilibFirst for the
 	// host target.
 	android.AddLoadHook(module, rustTestHostMultilib)
+	module.testModule = true
 	return module.Init()
 }
 
 func RustTestHostFactory() android.Module {
 	module, _ := NewRustTest(android.HostSupported)
+	module.testModule = true
 	return module.Init()
 }
 
diff --git a/testing/Android.bp b/testing/Android.bp
index 26a7d93..18dccb3 100644
--- a/testing/Android.bp
+++ b/testing/Android.bp
@@ -12,8 +12,10 @@
 
     ],
     srcs: [
+        "all_test_specs.go",
         "test_spec.go",
         "init.go",
+        "test.go",
     ],
     pluginFor: ["soong_build"],
 }
diff --git a/testing/all_test_specs.go b/testing/all_test_specs.go
new file mode 100644
index 0000000..9d4645b
--- /dev/null
+++ b/testing/all_test_specs.go
@@ -0,0 +1,45 @@
+package testing
+
+import (
+	"android/soong/android"
+)
+
+const ownershipDirectory = "ownership"
+const fileContainingFilePaths = "all_test_spec_paths.rsp"
+const allTestSpecsFile = "all_test_specs.pb"
+
+func AllTestSpecsFactory() android.Singleton {
+	return &allTestSpecsSingleton{}
+}
+
+type allTestSpecsSingleton struct {
+	// Path where the collected metadata is stored after successful validation.
+	outputPath android.OutputPath
+}
+
+func (this *allTestSpecsSingleton) GenerateBuildActions(ctx android.SingletonContext) {
+	var intermediateMetadataPaths android.Paths
+
+	ctx.VisitAllModules(func(module android.Module) {
+		if !ctx.ModuleHasProvider(module, TestSpecProviderKey) {
+			return
+		}
+		intermediateMetadataPaths = append(intermediateMetadataPaths, ctx.ModuleProvider(module, TestSpecProviderKey).(TestSpecProviderData).IntermediatePath)
+	})
+
+	rspFile := android.PathForOutput(ctx, fileContainingFilePaths)
+	this.outputPath = android.PathForOutput(ctx, ownershipDirectory, allTestSpecsFile)
+
+	rule := android.NewRuleBuilder(pctx, ctx)
+	cmd := rule.Command().
+		BuiltTool("metadata").
+		FlagWithArg("-rule ", "test_spec").
+		FlagWithRspFileInputList("-inputFile ", rspFile, intermediateMetadataPaths)
+	cmd.FlagWithOutput("-outputFile ", this.outputPath)
+	rule.Build("all_test_specs_rule", "Generate all test specifications")
+	ctx.Phony("all_test_specs", this.outputPath)
+}
+
+func (this *allTestSpecsSingleton) MakeVars(ctx android.MakeVarsContext) {
+	ctx.DistForGoal("test_specs", this.outputPath)
+}
diff --git a/testing/init.go b/testing/init.go
index 8820a60..206b430 100644
--- a/testing/init.go
+++ b/testing/init.go
@@ -18,10 +18,16 @@
 	"android/soong/android"
 )
 
+var (
+	pctx = android.NewPackageContext("android/soong/testing")
+)
+
 func init() {
 	RegisterBuildComponents(android.InitRegistrationContext)
+	pctx.HostBinToolVariable("metadata", "metadata")
 }
 
 func RegisterBuildComponents(ctx android.RegistrationContext) {
 	ctx.RegisterModuleType("test_spec", TestSpecFactory)
+	ctx.RegisterParallelSingletonType("all_test_specs", AllTestSpecsFactory)
 }
diff --git a/testing/test.go b/testing/test.go
new file mode 100644
index 0000000..44824e4
--- /dev/null
+++ b/testing/test.go
@@ -0,0 +1,21 @@
+// Copyright 2023 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.
+
+package testing
+
+import (
+	"android/soong/android"
+)
+
+var PrepareForTestWithTestSpecBuildComponents = android.FixtureRegisterWithContext(RegisterBuildComponents)
diff --git a/testing/test_spec.go b/testing/test_spec.go
index 1ad2768..c370f71 100644
--- a/testing/test_spec.go
+++ b/testing/test_spec.go
@@ -78,11 +78,11 @@
 }
 
 // Provider published by TestSpec
-type testSpecProviderData struct {
+type TestSpecProviderData struct {
 	IntermediatePath android.WritablePath
 }
 
-var testSpecProviderKey = blueprint.NewProvider(testSpecProviderData{})
+var TestSpecProviderKey = blueprint.NewProvider(TestSpecProviderData{})
 
 type TestModuleProviderData struct {
 }
@@ -120,7 +120,7 @@
 	android.WriteFileRule(ctx, intermediatePath, string(protoData))
 
 	ctx.SetProvider(
-		testSpecProviderKey, testSpecProviderData{
+		TestSpecProviderKey, TestSpecProviderData{
 			IntermediatePath: intermediatePath,
 		},
 	)