Derive deapexer module properties from transitive dependencies

Previously, the deapexer module properties were simply passed through
from the prebuilt_apex/apex_set modules. This change derives the
properties from the transitive dependencies of the modules so that it
can automatically include the contents of a bootclasspath_fragment
module without having to duplicate them in the exported_java_libs
property.

Part of this change involves moving the addition of dependencies onto
the prebuilt apex's contents from DepsMutator to ComponentDepsMutator
so that they can be visited in the createDeapexerModule() function. The
ComponentDepsMutator runs before prebuilts without matching sources are
renamed to match the source name which simplifies the process of adding
dependencies directly onto the prebuilts.

The deapexerDeps method was renamed as the dependencies are added both
for use by deapexer and also to create APEX variants for access by
platform_bootclasspath so the name was confusing.

Bug: 187266082
Test: m nothing
      m SOONG_CONFIG_art_module_source_build=false nothing
      - this fails but not because of missing APEX variants
Change-Id: Icb4f883e7d2b63739e5ff0dc6edb8a906d80189b

apex/prebuilt.go

@@ -114,19 +114,21 @@ func prebuiltApexModuleCreatorMutator(ctx android.TopDownMutatorContext) {
 	}
 }
 
-func (p *prebuiltCommon) deapexerDeps(ctx android.BottomUpMutatorContext) {
+// prebuiltApexContentsDeps adds dependencies onto the prebuilt apex module's contents.
+func (p *prebuiltCommon) prebuiltApexContentsDeps(ctx android.BottomUpMutatorContext) {
+	module := ctx.Module()
 	// Add dependencies onto the java modules that represent the java libraries that are provided by
 	// and exported from this prebuilt apex.
 	for _, exported := range p.deapexerProperties.Exported_java_libs {
-		dep := prebuiltApexExportedModuleName(ctx, exported)
-		ctx.AddFarVariationDependencies(ctx.Config().AndroidCommonTarget.Variations(), exportedJavaLibTag, dep)
+		dep := android.PrebuiltNameFromSource(exported)
+		ctx.AddDependency(module, exportedJavaLibTag, dep)
 	}
 
 	// Add dependencies onto the bootclasspath fragment modules that are exported from this prebuilt
 	// apex.
 	for _, exported := range p.deapexerProperties.Exported_bootclasspath_fragments {
-		dep := prebuiltApexExportedModuleName(ctx, exported)
-		ctx.AddFarVariationDependencies(ctx.Config().AndroidCommonTarget.Variations(), exportedBootclasspathFragmentTag, dep)
+		dep := android.PrebuiltNameFromSource(exported)
+		ctx.AddDependency(module, exportedBootclasspathFragmentTag, dep)
 	}
 }
 
@@ -398,15 +400,36 @@ func createApexSelectorModule(ctx android.TopDownMutatorContext, name string, ap
 
 // createDeapexerModuleIfNeeded will create a deapexer module if it is needed.
 //
-// A deapexer module is only needed when the prebuilt apex specifies an `exported_java_libs`
-// property as that indicates that the listed modules need access to files from within the prebuilt
-// .apex file.
+// A deapexer module is only needed when the prebuilt apex specifies one or more modules in either
+// the `exported_java_libs` or `exported_bootclasspath_fragments` properties as that indicates that
+// the listed modules need access to files from within the prebuilt .apex file.
 func createDeapexerModuleIfNeeded(ctx android.TopDownMutatorContext, deapexerName string, apexFileSource string, deapexerProperties *DeapexerProperties) {
 	// Only create the deapexer module if it is needed.
-	if len(deapexerProperties.Exported_java_libs) == 0 {
+	if len(deapexerProperties.Exported_java_libs)+len(deapexerProperties.Exported_bootclasspath_fragments) == 0 {
 		return
 	}
 
+	// Compute the deapexer properties from the transitive dependencies of this module.
+	deapexerProperties = &DeapexerProperties{}
+	ctx.WalkDeps(func(child, parent android.Module) bool {
+		tag := ctx.OtherModuleDependencyTag(child)
+
+		name := android.RemoveOptionalPrebuiltPrefix(ctx.OtherModuleName(child))
+		if java.IsBootclasspathFragmentContentDepTag(tag) || tag == exportedJavaLibTag {
+			deapexerProperties.Exported_java_libs = append(deapexerProperties.Exported_java_libs, name)
+		} else if tag == exportedBootclasspathFragmentTag {
+			deapexerProperties.Exported_bootclasspath_fragments = append(deapexerProperties.Exported_bootclasspath_fragments, name)
+			// Only visit the children of the bootclasspath_fragment for now.
+			return true
+		}
+
+		return false
+	})
+
+	// Remove any duplicates from the deapexer lists.
+	deapexerProperties.Exported_bootclasspath_fragments = android.FirstUniqueStrings(deapexerProperties.Exported_bootclasspath_fragments)
+	deapexerProperties.Exported_java_libs = android.FirstUniqueStrings(deapexerProperties.Exported_java_libs)
+
 	props := struct {
 		Name          *string
 		Selected_apex *string
@@ -511,8 +534,8 @@ func (p *Prebuilt) createPrebuiltApexModules(ctx android.TopDownMutatorContext)
 	p.selectedApexProperties.Selected_apex = proptools.StringPtr(apexFileSource)
 }
 
-func (p *Prebuilt) DepsMutator(ctx android.BottomUpMutatorContext) {
-	p.deapexerDeps(ctx)
+func (p *Prebuilt) ComponentDepsMutator(ctx android.BottomUpMutatorContext) {
+	p.prebuiltApexContentsDeps(ctx)
 }
 
 var _ ApexInfoMutator = (*Prebuilt)(nil)
@@ -772,8 +795,8 @@ func (a *ApexSet) createPrebuiltApexModules(ctx android.TopDownMutatorContext) {
 	a.selectedApexProperties.Selected_apex = proptools.StringPtr(apexFileSource)
 }
 
-func (a *ApexSet) DepsMutator(ctx android.BottomUpMutatorContext) {
-	a.deapexerDeps(ctx)
+func (a *ApexSet) ComponentDepsMutator(ctx android.BottomUpMutatorContext) {
+	a.prebuiltApexContentsDeps(ctx)
 }
 
 var _ ApexInfoMutator = (*ApexSet)(nil)

sdk/bootclasspath_fragment_sdk_test.go

@@ -95,9 +95,6 @@ func TestSnapshotWithBootclasspathFragment_ImageName(t *testing.T) {
 				prebuilt_apex {
 					name: "com.android.art",
 					src: "art.apex",
-					exported_java_libs: [
-						"mybootlib",
-					],
 					exported_bootclasspath_fragments: [
 						"mybootclasspathfragment",
 					],