Add override_module.

This new module type replaces the inherit-package function in make by
allowing developers to override the name, the certificate, and the
manifest package name of an android_app module.

Bug: 122957760
Fixes: 123640028
Test: app_test.go + BrowserGoogle
Change-Id: Iefe447e7078b25039233221361ef95c83a29973a

Android.bp

@@ -55,6 +55,7 @@ bootstrap_go_package {
         "android/namespace.go",
         "android/neverallow.go",
         "android/onceper.go",
+        "android/override_module.go",
         "android/package_ctx.go",
         "android/paths.go",
         "android/prebuilt.go",

android/config.go

@@ -895,16 +895,30 @@ func (c *deviceConfig) PlatPrivateSepolicyDirs() []string {
 }
 
 func (c *deviceConfig) OverrideManifestPackageNameFor(name string) (manifestName string, overridden bool) {
+	if newManifestName, overridden := c.manifestPackageNameOverrides().Load(name); overridden {
+		return newManifestName.(string), true
+	}
 	return findOverrideValue(c.config.productVariables.ManifestPackageNameOverrides, name,
 		"invalid override rule %q in PRODUCT_MANIFEST_PACKAGE_NAME_OVERRIDES should be <module_name>:<manifest_name>")
 }
 
 func (c *deviceConfig) OverrideCertificateFor(name string) (certificatePath string, overridden bool) {
-	return findOverrideValue(c.config.productVariables.CertificateOverrides, name,
+	if newCert, overridden := c.certificateOverrides().Load(name); overridden {
+		return newCert.(string), true
+	}
+	newCert, overridden := findOverrideValue(c.config.productVariables.CertificateOverrides, name,
 		"invalid override rule %q in PRODUCT_CERTIFICATE_OVERRIDES should be <module_name>:<certificate_module_name>")
+	if overridden {
+		// PRODUCT_CERTIFICATE_OVERRIDES only supports cert modules.
+		newCert = ":" + newCert
+	}
+	return newCert, overridden
 }
 
 func (c *deviceConfig) OverridePackageNameFor(name string) string {
+	if newName, overridden := c.moduleNameOverrides().Load(name); overridden {
+		return newName.(string)
+	}
 	newName, overridden := findOverrideValue(
 		c.config.productVariables.PackageNameOverrides,
 		name,

android/override_module.go

@@ -0,0 +1,97 @@
+package android
+
+import (
+	"github.com/google/blueprint/proptools"
+	"sync"
+)
+
+func init() {
+	RegisterModuleType("override_module", OverrideModuleFactory)
+}
+
+type OverrideModule struct {
+	ModuleBase
+	properties OverrideModuleProperties
+}
+
+type OverrideModuleProperties struct {
+	// base module to override
+	Base *string
+
+	// file path or module name (in the form ":module") of a certificate to override with
+	Certificate *string
+
+	// manifest package name to override with
+	Manifest_package_name *string
+}
+
+// TODO(jungjw): Work with the mainline team to see if we can deprecate all PRODUCT_*_OVERRIDES vars
+// and hand over overriding values directly to base module code.
+func processOverrides(ctx LoadHookContext, p *OverrideModuleProperties) {
+	base := proptools.String(p.Base)
+	if base == "" {
+		ctx.PropertyErrorf("base", "base module name must be provided")
+	}
+
+	config := ctx.DeviceConfig()
+	if other, loaded := config.moduleNameOverrides().LoadOrStore(base, ctx.ModuleName()); loaded {
+		ctx.ModuleErrorf("multiple overriding modules for %q, the other: %q", base, other.(string))
+	}
+
+	if p.Certificate != nil {
+		config.certificateOverrides().Store(base, *p.Certificate)
+	}
+
+	if p.Manifest_package_name != nil {
+		config.manifestPackageNameOverrides().Store(base, *p.Manifest_package_name)
+	}
+}
+
+func (i *OverrideModule) DepsMutator(ctx BottomUpMutatorContext) {
+	base := *i.properties.Base
+	// Right now, we add a dependency only to check the base module exists, and so are not using a tag here.
+	// TODO(jungjw): Add a tag and check the base module type once we finalize supported base module types.
+	ctx.AddDependency(ctx.Module(), nil, base)
+}
+
+func (i *OverrideModule) GenerateAndroidBuildActions(ctx ModuleContext) {
+	// All the overrides happen in the base module.
+	// TODO(jungjw): Check the base module type.
+}
+
+// override_module overrides an existing module with the specified properties.
+//
+// Currently, only android_app is officially supported.
+func OverrideModuleFactory() Module {
+	m := &OverrideModule{}
+	AddLoadHook(m, func(ctx LoadHookContext) {
+		processOverrides(ctx, &m.properties)
+	})
+	m.AddProperties(&m.properties)
+	InitAndroidModule(m)
+	return m
+}
+
+var moduleNameOverridesKey = NewOnceKey("moduleNameOverrides")
+
+func (c *deviceConfig) moduleNameOverrides() *sync.Map {
+	return c.Once(moduleNameOverridesKey, func() interface{} {
+		return &sync.Map{}
+	}).(*sync.Map)
+}
+
+var certificateOverridesKey = NewOnceKey("certificateOverrides")
+
+func (c *deviceConfig) certificateOverrides() *sync.Map {
+	return c.Once(certificateOverridesKey, func() interface{} {
+		return &sync.Map{}
+	}).(*sync.Map)
+}
+
+var manifestPackageNameOverridesKey = NewOnceKey("manifestPackageNameOverrides")
+
+func (c *deviceConfig) manifestPackageNameOverrides() *sync.Map {
+	return c.Once(manifestPackageNameOverridesKey, func() interface{} {
+		return &sync.Map{}
+	}).(*sync.Map)
+}

apex/apex.go

@@ -534,7 +534,7 @@ func (a *apexBundle) DepsMutator(ctx android.BottomUpMutatorContext) {
 func (a *apexBundle) getCertString(ctx android.BaseContext) string {
 	certificate, overridden := ctx.DeviceConfig().OverrideCertificateFor(ctx.ModuleName())
 	if overridden {
-		return ":" + certificate
+		return certificate
 	}
 	return String(a.properties.Certificate)
 }

java/app.go

@@ -392,7 +392,7 @@ func (a *AndroidApp) collectAppDeps(ctx android.ModuleContext) ([]jniLib, []Cert
 func (a *AndroidApp) getCertString(ctx android.BaseContext) string {
 	certificate, overridden := ctx.DeviceConfig().OverrideCertificateFor(ctx.ModuleName())
 	if overridden {
-		return ":" + certificate
+		return certificate
 	}
 	return String(a.appProperties.Certificate)
 }

java/app_test.go

@@ -747,3 +747,57 @@ func TestPackageNameOverride(t *testing.T) {
 		})
 	}
 }
+
+func TestOverrideModule(t *testing.T) {
+	ctx := testJava(t, `
+		android_app {
+			name: "foo",
+			srcs: ["a.java"],
+		}
+
+		override_module {
+			name: "bar",
+			base: "foo",
+			certificate: ":new_certificate",
+			manifest_package_name: "org.dandroid.bp",
+		}
+
+		android_app_certificate {
+			name: "new_certificate",
+	    certificate: "cert/new_cert",
+		}
+		`)
+
+	// The base module still contains all the final outputs after overrides.
+	foo := ctx.ModuleForTests("foo", "android_common")
+
+	// Check the final apk name
+	outputs := foo.AllOutputs()
+	e := buildDir + "/target/product/test_device/system/app/bar/bar.apk"
+	found := false
+	for _, o := range outputs {
+		if o == e {
+			found = true
+			break
+		}
+	}
+	if !found {
+		t.Errorf("Can't find %q in output files.\nAll outputs:%v", e, outputs)
+	}
+
+	// Check the certificate paths
+	signapk := foo.Output("foo.apk")
+	signFlags := signapk.Args["certificates"]
+	e = "cert/new_cert.x509.pem cert/new_cert.pk8"
+	if e != signFlags {
+		t.Errorf("Incorrect signing flags, expected: %q, got: %q", e, signFlags)
+	}
+
+	// Check the manifest package name
+	res := foo.Output("package-res.apk")
+	aapt2Flags := res.Args["flags"]
+	e = "--rename-manifest-package org.dandroid.bp"
+	if !strings.Contains(aapt2Flags, e) {
+		t.Errorf("package renaming flag, %q is missing in aapt2 link flags, %q", e, aapt2Flags)
+	}
+}

java/java_test.go

@@ -81,11 +81,13 @@ func testContext(config android.Config, bp string,
 	ctx.RegisterModuleType("droiddoc_host", android.ModuleFactoryAdaptor(DroiddocHostFactory))
 	ctx.RegisterModuleType("droiddoc_template", android.ModuleFactoryAdaptor(ExportedDroiddocDirFactory))
 	ctx.RegisterModuleType("java_sdk_library", android.ModuleFactoryAdaptor(SdkLibraryFactory))
+	ctx.RegisterModuleType("override_module", android.ModuleFactoryAdaptor(android.OverrideModuleFactory))
 	ctx.RegisterModuleType("prebuilt_apis", android.ModuleFactoryAdaptor(PrebuiltApisFactory))
 	ctx.PreArchMutators(android.RegisterPrebuiltsPreArchMutators)
 	ctx.PreArchMutators(android.RegisterPrebuiltsPostDepsMutators)
 	ctx.PreArchMutators(android.RegisterDefaultsPreArchMutators)
 	ctx.PreArchMutators(func(ctx android.RegisterMutatorsContext) {
+		ctx.TopDown("load_hooks", android.LoadHookMutator).Parallel()
 		ctx.TopDown("prebuilt_apis", PrebuiltApisMutator).Parallel()
 		ctx.TopDown("java_sdk_library", SdkLibraryMutator).Parallel()
 	})