Automatically add system and system_ext autogen RRO to vendor/product

This CL creates a dependency edge from vendor/product to system and
system_ext. A post deps mutator will walk the transitive closure and add
the corresponding autogenerated RROs to deps.

Bug: 374371755
Bug: 375277835

Test: m soong_generated_vendor_filesystem_test
NOTICE is the last diff

Change-Id: Iffe64174a0d639dc224505a08eccd0a1dedc9f39
diff --git a/filesystem/filesystem.go b/filesystem/filesystem.go
index 5b217ae..eb34180 100644
--- a/filesystem/filesystem.go
+++ b/filesystem/filesystem.go
@@ -25,6 +25,7 @@
 
 	"android/soong/android"
 	"android/soong/cc"
+	"android/soong/java"
 	"android/soong/linkerconfig"
 
 	"github.com/google/blueprint"
@@ -33,6 +34,7 @@
 
 func init() {
 	registerBuildComponents(android.InitRegistrationContext)
+	registerMutators(android.InitRegistrationContext)
 }
 
 func registerBuildComponents(ctx android.RegistrationContext) {
@@ -45,6 +47,12 @@
 	ctx.RegisterModuleType("avb_gen_vbmeta_image_defaults", avbGenVbmetaImageDefaultsFactory)
 }
 
+func registerMutators(ctx android.RegistrationContext) {
+	ctx.PostDepsMutators(func(ctx android.RegisterMutatorsContext) {
+		ctx.BottomUp("add_autogenerated_rro_deps", addAutogeneratedRroDeps)
+	})
+}
+
 type filesystem struct {
 	android.ModuleBase
 	android.PackagingBase
@@ -170,6 +178,14 @@
 	// Path to the dev nodes description file. This is only needed for building the ramdisk
 	// partition and should not be explicitly specified.
 	Dev_nodes_description_file *string `android:"path" blueprint:"mutated"`
+
+	// Additional dependencies used for building android products
+	Android_filesystem_deps AndroidFilesystemDeps
+}
+
+type AndroidFilesystemDeps struct {
+	System     *string
+	System_ext *string
 }
 
 // Additional properties required to generate erofs FS partitions.
@@ -235,6 +251,12 @@
 	depTag
 }
 
+type interPartitionDepTag struct {
+	blueprint.BaseDependencyTag
+}
+
+var interPartitionDependencyTag = interPartitionDepTag{}
+
 var _ android.ExcludeFromVisibilityEnforcementTag = (*depTagWithVisibilityEnforcementBypass)(nil)
 
 func (t depTagWithVisibilityEnforcementBypass) ExcludeFromVisibilityEnforcement() {}
@@ -257,6 +279,12 @@
 	} else {
 		f.AddDeps(ctx, dependencyTag)
 	}
+	if f.properties.Android_filesystem_deps.System != nil {
+		ctx.AddDependency(ctx.Module(), interPartitionDependencyTag, proptools.String(f.properties.Android_filesystem_deps.System))
+	}
+	if f.properties.Android_filesystem_deps.System_ext != nil {
+		ctx.AddDependency(ctx.Module(), interPartitionDependencyTag, proptools.String(f.properties.Android_filesystem_deps.System_ext))
+	}
 }
 
 type fsType int
@@ -1004,3 +1032,30 @@
 		image, maxSize)
 	cmd.Implicit(image)
 }
+
+// addAutogeneratedRroDeps walks the transitive closure of vendor and product partitions.
+// It visits apps installed in system and system_ext partitions, and adds the autogenerated
+// RRO modules to its own deps.
+func addAutogeneratedRroDeps(ctx android.BottomUpMutatorContext) {
+	f, ok := ctx.Module().(*filesystem)
+	if !ok {
+		return
+	}
+	thisPartition := f.PartitionType()
+	if thisPartition != "vendor" && thisPartition != "product" {
+		return
+	}
+	ctx.WalkDeps(func(child, parent android.Module) bool {
+		depTag := ctx.OtherModuleDependencyTag(child)
+		if parent.Name() == f.Name() && depTag != interPartitionDependencyTag {
+			return false // This is a module listed in deps of vendor/product filesystem
+		}
+		if vendorOverlay := java.AutogeneratedRroModuleName(ctx, child.Name(), "vendor"); ctx.OtherModuleExists(vendorOverlay) && thisPartition == "vendor" {
+			ctx.AddFarVariationDependencies(nil, dependencyTagWithVisibilityEnforcementBypass, vendorOverlay)
+		}
+		if productOverlay := java.AutogeneratedRroModuleName(ctx, child.Name(), "product"); ctx.OtherModuleExists(productOverlay) && thisPartition == "product" {
+			ctx.AddFarVariationDependencies(nil, dependencyTagWithVisibilityEnforcementBypass, productOverlay)
+		}
+		return true
+	})
+}