Merge changes Iaca95efc,I7ccd5581

* changes:
  Add RemoveOptionalPrebuiltPrefix() helper function
  Delegate work of apexInfoMutator to ApexInfoMutator interface
diff --git a/android/prebuilt.go b/android/prebuilt.go
index bb98ed4..8114a65 100644
--- a/android/prebuilt.go
+++ b/android/prebuilt.go
@@ -17,6 +17,7 @@
 import (
 	"fmt"
 	"reflect"
+	"strings"
 
 	"github.com/google/blueprint"
 	"github.com/google/blueprint/proptools"
@@ -74,6 +75,12 @@
 	srcsPropertyName string
 }
 
+// RemoveOptionalPrebuiltPrefix returns the result of removing the "prebuilt_" prefix from the
+// supplied name if it has one, or returns the name unmodified if it does not.
+func RemoveOptionalPrebuiltPrefix(name string) string {
+	return strings.TrimPrefix(name, "prebuilt_")
+}
+
 func (p *Prebuilt) Name(name string) string {
 	return "prebuilt_" + name
 }
diff --git a/apex/apex.go b/apex/apex.go
index 2a81b9b..261284c 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -728,7 +728,9 @@
 
 var ApexBundleInfoProvider = blueprint.NewMutatorProvider(ApexBundleInfo{}, "apex_info")
 
-// apexInfoMutator is responsible for collecting modules that need to have apex variants. They are
+var _ ApexInfoMutator = (*apexBundle)(nil)
+
+// ApexInfoMutator is responsible for collecting modules that need to have apex variants. They are
 // identified by doing a graph walk starting from an apexBundle. Basically, all the (direct and
 // indirect) dependencies are collected. But a few types of modules that shouldn't be included in
 // the apexBundle (e.g. stub libraries) are not collected. Note that a single module can be depended
@@ -739,15 +741,7 @@
 // The apexMutator uses that list to create module variants for the apexes to which it belongs.
 // The relationship between module variants and apexes is not one-to-one as variants will be
 // shared between compatible apexes.
-func apexInfoMutator(mctx android.TopDownMutatorContext) {
-	if !mctx.Module().Enabled() {
-		return
-	}
-
-	a, ok := mctx.Module().(*apexBundle)
-	if !ok {
-		return
-	}
+func (a *apexBundle) ApexInfoMutator(mctx android.TopDownMutatorContext) {
 
 	// The VNDK APEX is special. For the APEX, the membership is described in a very different
 	// way. There is no dependency from the VNDK APEX to the VNDK libraries. Instead, VNDK
@@ -826,6 +820,25 @@
 	})
 }
 
+type ApexInfoMutator interface {
+	// ApexInfoMutator implementations must call BuildForApex(ApexInfo) on any modules that are
+	// depended upon by an apex and which require an apex specific variant.
+	ApexInfoMutator(android.TopDownMutatorContext)
+}
+
+// apexInfoMutator delegates the work of identifying which modules need an ApexInfo and apex
+// specific variant to modules that support the ApexInfoMutator.
+func apexInfoMutator(mctx android.TopDownMutatorContext) {
+	if !mctx.Module().Enabled() {
+		return
+	}
+
+	if a, ok := mctx.Module().(ApexInfoMutator); ok {
+		a.ApexInfoMutator(mctx)
+		return
+	}
+}
+
 // apexUniqueVariationsMutator checks if any dependencies use unique apex variations. If so, use
 // unique apex variations for this module. See android/apex.go for more about unique apex variant.
 // TODO(jiyong): move this to android/apex.go?
@@ -2165,7 +2178,7 @@
 func normalizeModuleName(moduleName string) string {
 	// Prebuilt modules (e.g. java_import, etc.) have "prebuilt_" prefix added by the build
 	// system. Trim the prefix for the check since they are confusing
-	moduleName = strings.TrimPrefix(moduleName, "prebuilt_")
+	moduleName = android.RemoveOptionalPrebuiltPrefix(moduleName)
 	if strings.HasPrefix(moduleName, "libclang_rt.") {
 		// This module has many arch variants that depend on the product being built.
 		// We don't want to list them all
diff --git a/cc/cc.go b/cc/cc.go
index 9383e39..d1f5c47 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -2749,7 +2749,7 @@
 func baseLibName(depName string) string {
 	libName := strings.TrimSuffix(depName, llndkLibrarySuffix)
 	libName = strings.TrimSuffix(libName, vendorPublicLibrarySuffix)
-	libName = strings.TrimPrefix(libName, "prebuilt_")
+	libName = android.RemoveOptionalPrebuiltPrefix(libName)
 	return libName
 }