java_sdk_library: Control shared library use

Previously, all java_sdk_library instances were assumed to be usable as
shared libraries, i.e. referenced from <uses-library> in Android
manifest. However, that was not true for any instances that specified
api_only: true and will not be true for many of the new Android
modules.

One consequence of this assumption is that use of one of the api_only
instances could (but fortunately does not appear to) have lead to an
invalid library being referenced in an app's manifest which would
prevent the app from loading. That would have been done automatically
by the implicit sdk library tracking and manifest fixing mechanism and
there would have been nothing a developer could have done about it.

Changes:
1) Prevents api_only instances from participating in the automatic
   tracking which will prevent them from being added to Android
   manifests and breaking apps.

2) Add a new shared_library property that can have the same effect as
   api_only while still creating a runtime implementation library.

3) Renamed commonProperties to commonSdkLibraryProperties to
   disambiguate it from the ModuleBase.commonProperties field.

4) Extracts requiresRuntimeImplementationLibrary() to remove duplicate
   code accessing the Api_only property.

5) Tests for the api_only and shared_library behaviours.

Test: m nothing - added tests, tests broke, fixed code, tests passed.
Bug: 156723295
Change-Id: Iccf509e808d5ff53522188541a4c54d8f9ada93c

java/java_test.go

@@ -1157,6 +1157,16 @@ func TestJavaSdkLibrary(t *testing.T) {
 			libs: ["foo", "bar.stubs"],
 			sdk_version: "system_current",
 		}
+		java_sdk_library {
+			name: "barney",
+			srcs: ["c.java"],
+			api_only: true,
+		}
+		java_sdk_library {
+			name: "betty",
+			srcs: ["c.java"],
+			shared_library: false,
+		}
 		java_sdk_library_import {
 		    name: "quuz",
 				public: {
@@ -1169,10 +1179,17 @@ func TestJavaSdkLibrary(t *testing.T) {
 					jars: ["b.jar"],
 				},
 		}
+		java_sdk_library_import {
+		    name: "wilma",
+				public: {
+					jars: ["b.jar"],
+				},
+				shared_library: false,
+		}
 		java_library {
 		    name: "qux",
 		    srcs: ["c.java"],
-		    libs: ["baz", "fred", "quuz.stubs"],
+		    libs: ["baz", "fred", "quuz.stubs", "wilma", "barney", "betty"],
 		    sdk_version: "system_current",
 		}
 		java_library {

java/sdk_library.go

@@ -372,7 +372,10 @@ type sdkLibraryProperties struct {
 	// Defaults to "api".
 	Api_dir *string
 
-	// If set to true there is no runtime library.
+	// Determines whether a runtime implementation library is built; defaults to false.
+	//
+	// If true then it also prevents the module from being used as a shared module, i.e.
+	// it is as is shared_library: false, was set.
 	Api_only *bool
 
 	// local files that are used within user customized droiddoc options.
@@ -532,6 +535,13 @@ type commonToSdkLibraryAndImportProperties struct {
 	//
 	// TODO(b/155480189) - Remove once naming inconsistencies have been resolved.
 	Naming_scheme *string
+
+	// Specifies whether this module can be used as an Android shared library; defaults
+	// to true.
+	//
+	// An Android shared library is one that can be referenced in a <uses-library> element
+	// in an AndroidManifest.xml.
+	Shared_library *bool
 }
 
 // Common code between sdk library and sdk library import
@@ -542,7 +552,7 @@ type commonToSdkLibraryAndImport struct {
 
 	namingScheme sdkLibraryComponentNamingScheme
 
-	commonProperties commonToSdkLibraryAndImportProperties
+	commonSdkLibraryProperties commonToSdkLibraryAndImportProperties
 
 	// Functionality related to this being used as a component of a java_sdk_library.
 	EmbeddableSdkLibraryComponent
@@ -551,14 +561,14 @@ type commonToSdkLibraryAndImport struct {
 func (c *commonToSdkLibraryAndImport) initCommon(moduleBase *android.ModuleBase) {
 	c.moduleBase = moduleBase
 
-	moduleBase.AddProperties(&c.commonProperties)
+	moduleBase.AddProperties(&c.commonSdkLibraryProperties)
 
 	// Initialize this as an sdk library component.
 	c.initSdkLibraryComponent(moduleBase)
 }
 
 func (c *commonToSdkLibraryAndImport) initCommonAfterDefaultsApplied(ctx android.DefaultableHookContext) bool {
-	schemeProperty := proptools.StringDefault(c.commonProperties.Naming_scheme, "default")
+	schemeProperty := proptools.StringDefault(c.commonSdkLibraryProperties.Naming_scheme, "default")
 	switch schemeProperty {
 	case "default":
 		c.namingScheme = &defaultNamingScheme{}
@@ -569,8 +579,11 @@ func (c *commonToSdkLibraryAndImport) initCommonAfterDefaultsApplied(ctx android
 		return false
 	}
 
+	// Only track this sdk library if this can be used as a shared library.
+	if c.sharedLibrary() {
 		// Use the name specified in the module definition as the owner.
 		c.sdkLibraryComponentProperties.SdkLibraryToImplicitlyTrack = proptools.StringPtr(c.moduleBase.BaseModuleName())
+	}
 
 	return true
 }
@@ -740,17 +753,24 @@ func (c *commonToSdkLibraryAndImport) selectHeaderJarsForSdkVersion(ctx android.
 func (c *commonToSdkLibraryAndImport) sdkComponentPropertiesForChildLibrary() interface{} {
 	componentProps := &struct {
 		SdkLibraryToImplicitlyTrack *string
-	}{
+	}{}
+
+	if c.sharedLibrary() {
 		// Mark the stubs library as being components of this java_sdk_library so that
 		// any app that includes code which depends (directly or indirectly) on the stubs
 		// library will have the appropriate <uses-library> invocation inserted into its
 		// manifest if necessary.
-		SdkLibraryToImplicitlyTrack: proptools.StringPtr(c.moduleBase.BaseModuleName()),
+		componentProps.SdkLibraryToImplicitlyTrack = proptools.StringPtr(c.moduleBase.BaseModuleName())
 	}
 
 	return componentProps
 }
 
+// Check if this can be used as a shared library.
+func (c *commonToSdkLibraryAndImport) sharedLibrary() bool {
+	return proptools.BoolDefault(c.commonSdkLibraryProperties.Shared_library, true)
+}
+
 // Properties related to the use of a module as an component of a java_sdk_library.
 type SdkLibraryComponentProperties struct {
 
@@ -907,12 +927,15 @@ func (module *SdkLibrary) DepsMutator(ctx android.BottomUpMutatorContext) {
 		}
 	}
 
-	if !proptools.Bool(module.sdkLibraryProperties.Api_only) {
+	if module.requiresRuntimeImplementationLibrary() {
+		if module.sharedLibrary() {
 			// Add dependency to the rule for generating the xml permissions file
 			ctx.AddDependency(module, xmlPermissionsFileTag, module.xmlFileName())
 		}
 
+		// Only add the deps for the library if it is actually going to be built.
 		module.Library.deps(ctx)
+	}
 }
 
 func (module *SdkLibrary) OutputFiles(tag string) (android.Paths, error) {
@@ -925,8 +948,8 @@ func (module *SdkLibrary) OutputFiles(tag string) (android.Paths, error) {
 }
 
 func (module *SdkLibrary) GenerateAndroidBuildActions(ctx android.ModuleContext) {
-	// Don't build an implementation library if this is api only.
+	// Only build an implementation library if required.
-	if !proptools.Bool(module.sdkLibraryProperties.Api_only) {
+	if module.requiresRuntimeImplementationLibrary() {
 		module.Library.GenerateAndroidBuildActions(ctx)
 	}
 
@@ -949,7 +972,7 @@ func (module *SdkLibrary) GenerateAndroidBuildActions(ctx android.ModuleContext)
 }
 
 func (module *SdkLibrary) AndroidMkEntries() []android.AndroidMkEntries {
-	if proptools.Bool(module.sdkLibraryProperties.Api_only) {
+	if !module.requiresRuntimeImplementationLibrary() {
 		return nil
 	}
 	entriesList := module.Library.AndroidMkEntries()
@@ -1387,9 +1410,12 @@ func (module *SdkLibrary) CreateInternalModules(mctx android.DefaultableHookCont
 		module.createStubsLibrary(mctx, scope)
 	}
 
-	if !proptools.Bool(module.sdkLibraryProperties.Api_only) {
+	if module.requiresRuntimeImplementationLibrary() {
-		// for runtime
+		// Only create an XML permissions file that declares the library as being usable
+		// as a shared library if required.
+		if module.sharedLibrary() {
 			module.createXmlFile(mctx)
+		}
 
 		// record java_sdk_library modules so that they are exported to make
 		javaSdkLibraries := javaSdkLibraries(mctx.Config())
@@ -1414,6 +1440,10 @@ func (module *SdkLibrary) InitSdkLibraryProperties() {
 	module.deviceProperties.IsSDKLibrary = true
 }
 
+func (module *SdkLibrary) requiresRuntimeImplementationLibrary() bool {
+	return !proptools.Bool(module.sdkLibraryProperties.Api_only)
+}
+
 // Defines how to name the individual component modules the sdk library creates.
 type sdkLibraryComponentNamingScheme interface {
 	stubsLibraryModuleName(scope *apiScope, baseName string) string
@@ -1492,6 +1522,18 @@ func SdkLibraryFactory() android.Module {
 	android.AddVisibilityProperty(module, "stubs_source_visibility", &module.sdkLibraryProperties.Stubs_source_visibility)
 
 	module.SetDefaultableHook(func(ctx android.DefaultableHookContext) {
+		// If no implementation is required then it cannot be used as a shared library
+		// either.
+		if !module.requiresRuntimeImplementationLibrary() {
+			// If shared_library has been explicitly set to true then it is incompatible
+			// with api_only: true.
+			if proptools.Bool(module.commonSdkLibraryProperties.Shared_library) {
+				ctx.PropertyErrorf("api_only/shared_library", "inconsistent settings, shared_library and api_only cannot both be true")
+			}
+			// Set shared_library: false.
+			module.commonSdkLibraryProperties.Shared_library = proptools.BoolPtr(false)
+		}
+
 		if module.initCommonAfterDefaultsApplied(ctx) {
 			module.CreateInternalModules(ctx)
 		}
@@ -1916,7 +1958,7 @@ func (s *sdkLibrarySdkMemberProperties) PopulateFromVariant(ctx android.SdkMembe
 	}
 
 	s.Libs = sdk.properties.Libs
-	s.Naming_scheme = sdk.commonProperties.Naming_scheme
+	s.Naming_scheme = sdk.commonSdkLibraryProperties.Naming_scheme
 }
 
 func (s *sdkLibrarySdkMemberProperties) AddToPropertySet(ctx android.SdkMemberContext, propertySet android.BpPropertySet) {