Disable dexpreopt if optional_uses_libs does not have an impl

At ToT, an optional_uses_libs is not added to the build time CLC if it
does not exist in the tree. One edge case here is
java_sdk_library_import, which might exist in the tree, but without an
implementation. This cause issues during analysis when we try to verify
the correctness of the build time CLC.

This CL disables dexpreopt if a dependency does not have an
implementation. To limit inadvertent side effects, this is restricted to
java_sdk_library(_import) module types. (more precisely, it is restricted
to java_sdk_library_import, since the source module type will always
have an impl)

Bug: 315802285
Test: Added a unit test
Test: m nothing
Test: printf debugging in internal main, verified that this CL does not
disable dexpreopt on any android app inadvertently

Change-Id: I173fc2f3ff654fe4091e9a43322164afd3222ee7

java/aar.go

@@ -808,6 +808,9 @@ func (a *AndroidLibrary) DepsMutator(ctx android.BottomUpMutatorContext) {
 func (a *AndroidLibrary) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	a.aapt.isLibrary = true
 	a.classLoaderContexts = a.usesLibrary.classLoaderContextForUsesLibDeps(ctx)
+	if a.usesLibrary.shouldDisableDexpreopt {
+		a.dexpreopter.disableDexpreopt()
+	}
 	a.aapt.buildActions(ctx,
 		aaptBuildActionOptions{
 			sdkContext:                     android.SdkContext(a),

java/app.go

@@ -777,6 +777,9 @@ func (a *AndroidApp) generateAndroidBuildActions(ctx android.ModuleContext) {
 	a.onDeviceDir = android.InstallPathToOnDevicePath(ctx, a.installDir)
 
 	a.classLoaderContexts = a.usesLibrary.classLoaderContextForUsesLibDeps(ctx)
+	if a.usesLibrary.shouldDisableDexpreopt {
+		a.dexpreopter.disableDexpreopt()
+	}
 
 	var noticeAssetPath android.WritablePath
 	if Bool(a.appProperties.Embed_notices) || ctx.Config().IsEnvTrue("ALWAYS_EMBED_NOTICES") {
@@ -1547,6 +1550,9 @@ type usesLibrary struct {
 
 	// Whether to enforce verify_uses_library check.
 	enforce bool
+
+	// Whether dexpreopt should be disabled
+	shouldDisableDexpreopt bool
 }
 
 func (u *usesLibrary) addLib(lib string, optional bool) {
@@ -1628,6 +1634,15 @@ func (u *usesLibrary) classLoaderContextForUsesLibDeps(ctx android.ModuleContext
 			}
 		}
 
+		// Skip java_sdk_library dependencies that provide stubs, but not an implementation.
+		// This will be restricted to optional_uses_libs
+		if sdklib, ok := m.(SdkLibraryDependency); ok {
+			if tag == usesLibOptTag && sdklib.DexJarBuildPath(ctx).PathOrNil() == nil {
+				u.shouldDisableDexpreopt = true
+				return
+			}
+		}
+
 		if lib, ok := m.(UsesLibraryDependency); ok {
 			libName := dep
 			if ulib, ok := m.(ProvidesUsesLib); ok && ulib.ProvidesUsesLib() != nil {

java/app_import.go

@@ -319,6 +319,9 @@ func (a *AndroidAppImport) generateAndroidBuildActions(ctx android.ModuleContext
 
 	a.dexpreopter.enforceUsesLibs = a.usesLibrary.enforceUsesLibraries()
 	a.dexpreopter.classLoaderContexts = a.usesLibrary.classLoaderContextForUsesLibDeps(ctx)
+	if a.usesLibrary.shouldDisableDexpreopt {
+		a.dexpreopter.disableDexpreopt()
+	}
 
 	if a.usesLibrary.enforceUsesLibraries() {
 		a.usesLibrary.verifyUsesLibrariesAPK(ctx, srcApk)

java/app_test.go

@@ -4378,3 +4378,26 @@ func TestAppFlagsPackages(t *testing.T) {
 		"--feature-flags @out/soong/.intermediates/bar/intermediate.txt --feature-flags @out/soong/.intermediates/baz/intermediate.txt",
 	)
 }
+
+// Test that dexpreopt is disabled if an optional_uses_libs exists, but does not provide an implementation.
+func TestNoDexpreoptOptionalUsesLibDoesNotHaveImpl(t *testing.T) {
+	bp := `
+		java_sdk_library_import {
+			name: "sdklib_noimpl",
+			public: {
+				jars: ["stub.jar"],
+			},
+		}
+		android_app {
+			name: "app",
+			srcs: ["a.java"],
+			sdk_version: "current",
+			optional_uses_libs: [
+				"sdklib_noimpl",
+			],
+		}
+	`
+	result := prepareForJavaTest.RunTestWithBp(t, bp)
+	dexpreopt := result.ModuleForTests("app", "android_common").MaybeRule("dexpreopt").Rule
+	android.AssertBoolEquals(t, "dexpreopt should be disabled if optional_uses_libs does not have an implementation", true, dexpreopt == nil)
+}

java/dexpreopt.go

@@ -102,6 +102,11 @@ type dexpreopter struct {
 	dexpreoptProperties       DexpreoptProperties
 	importDexpreoptProperties ImportDexpreoptProperties
 
+	// If true, the dexpreopt rules will not be generated
+	// Unlike Dex_preopt.Enabled which is user-facing,
+	// shouldDisableDexpreopt is a mutated propery.
+	shouldDisableDexpreopt bool
+
 	installPath         android.InstallPath
 	uncompressedDex     bool
 	isSDKLibrary        bool
@@ -197,6 +202,10 @@ func (d *dexpreopter) dexpreoptDisabled(ctx android.BaseModuleContext, libName s
 		return true
 	}
 
+	if d.shouldDisableDexpreopt {
+		return true
+	}
+
 	// If the module is from a prebuilt APEX, it shouldn't be installable, but it can still be
 	// dexpreopted.
 	if !ctx.Module().(DexpreopterInterface).IsInstallable() && !forPrebuiltApex(ctx) {
@@ -528,3 +537,7 @@ func (d *dexpreopter) AndroidMkEntriesForApex() []android.AndroidMkEntries {
 func (d *dexpreopter) OutputProfilePathOnHost() android.Path {
 	return d.outputProfilePathOnHost
 }
+
+func (d *dexpreopter) disableDexpreopt() {
+	d.shouldDisableDexpreopt = true
+}

java/java.go

@@ -719,6 +719,9 @@ func (j *Library) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 		setUncompressDex(ctx, &j.dexpreopter, &j.dexer)
 		j.dexpreopter.uncompressedDex = *j.dexProperties.Uncompress_dex
 		j.classLoaderContexts = j.usesLibrary.classLoaderContextForUsesLibDeps(ctx)
+		if j.usesLibrary.shouldDisableDexpreopt {
+			j.dexpreopter.disableDexpreopt()
+		}
 	}
 	j.compile(ctx, nil, nil, nil)