Surface Java APIs Used By APK-only Modules.

Previously we were only generating used-by API-coverage for APEX modules.
This change adds support for APK-only modules such as NetworkStack and DocumentsUI.

Bug: b/216313756
Forrest Run: https://android-build.googleplex.com/builds/abtd/run/L10800000953846781

Test: TARGET_BUILD_VARIANT=userdebug PRODUCT=mainline_modules_x86 ./vendor/google/build/build_unbundled_coverage_mainline_module.sh -j16

Change-Id: Id17e4a55c2a52e9903632a654e778f8d54982dfc
Merged-In: Id17e4a55c2a52e9903632a654e778f8d54982dfc
(cherry picked from commit 56d75785bd52c8a8f684935eed67fceb2c0e6850)
diff --git a/java/androidmk.go b/java/androidmk.go
index e3e85a9..f51e072 100644
--- a/java/androidmk.go
+++ b/java/androidmk.go
@@ -409,7 +409,15 @@
 				entries.SetOptionalPaths("LOCAL_SOONG_LINT_REPORTS", app.linter.reports)
 			},
 		},
-	}}
+		ExtraFooters: []android.AndroidMkExtraFootersFunc{
+			func(w io.Writer, name, prefix, moduleDir string) {
+				if app.javaApiUsedByOutputFile.String() != "" {
+					fmt.Fprintf(w, "$(call dist-for-goals,%s,%s:%s/$(notdir %s))\n",
+						app.installApkName, app.javaApiUsedByOutputFile.String(), "java_apis_used_by_apex", app.javaApiUsedByOutputFile.String())
+				}
+			},
+		}},
+	}
 }
 
 func (a *AndroidApp) getOverriddenPackages() []string {
diff --git a/java/app.go b/java/app.go
index a1a854e..1b65f33 100755
--- a/java/app.go
+++ b/java/app.go
@@ -169,6 +169,8 @@
 	overriddenManifestPackageName string
 
 	android.ApexBundleDepsInfo
+
+	javaApiUsedByOutputFile android.ModuleOutPath
 }
 
 func (a *AndroidApp) IsInstallable() bool {
@@ -277,6 +279,7 @@
 func (a *AndroidApp) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	a.checkAppSdkVersions(ctx)
 	a.generateAndroidBuildActions(ctx)
+	a.generateJavaUsedByApex(ctx)
 }
 
 func (a *AndroidApp) checkAppSdkVersions(ctx android.ModuleContext) {
diff --git a/java/app_builder.go b/java/app_builder.go
index 74cd85c..31023cb 100644
--- a/java/app_builder.go
+++ b/java/app_builder.go
@@ -258,6 +258,18 @@
 	})
 }
 
+func (a *AndroidApp) generateJavaUsedByApex(ctx android.ModuleContext) {
+	javaApiUsedByOutputFile := android.PathForModuleOut(ctx, a.installApkName+"_using.xml")
+	javaUsedByRule := android.NewRuleBuilder(pctx, ctx)
+	javaUsedByRule.Command().
+		Tool(android.PathForSource(ctx, "build/soong/scripts/gen_java_usedby_apex.sh")).
+		BuiltTool("dexdeps").
+		Output(javaApiUsedByOutputFile).
+		Input(a.Library.Module.outputFile)
+	javaUsedByRule.Build("java_usedby_list", "Generate Java APIs used by Apex")
+	a.javaApiUsedByOutputFile = javaApiUsedByOutputFile
+}
+
 func targetToJniDir(target android.Target) string {
 	return filepath.Join("lib", target.Arch.Abi[0])
 }
diff --git a/java/testing.go b/java/testing.go
index 82aa29b..9178b16 100644
--- a/java/testing.go
+++ b/java/testing.go
@@ -54,6 +54,8 @@
 		"build/soong/java/lint_defaults.txt": nil,
 		// Needed for apps that do not provide their own.
 		"build/make/target/product/security": nil,
+		// Required to generate Java used-by API coverage
+		"build/soong/scripts/gen_java_usedby_apex.sh": nil,
 	}.AddToFixture(),
 )