diff --git a/android/module.go b/android/module.go
index abf2cae..201c27a 100644
--- a/android/module.go
+++ b/android/module.go
@@ -1425,6 +1425,10 @@
 	Srcs() Paths
 }
 
+type HostToolProvider interface {
+	HostToolPath() OptionalPath
+}
+
 // Returns a list of paths expanded from globs and modules referenced using ":module" syntax.  The property must
 // be tagged with `android:"path" to support automatic source module dependency resolution.
 //
diff --git a/android/proto.go b/android/proto.go
index 83dc32a..5247c68 100644
--- a/android/proto.go
+++ b/android/proto.go
@@ -17,6 +17,7 @@
 import (
 	"strings"
 
+	"github.com/google/blueprint"
 	"github.com/google/blueprint/proptools"
 )
 
@@ -35,21 +36,61 @@
 	SubDir                ModuleGenPath
 	OutTypeFlag           string
 	OutParams             []string
+	Deps                  Paths
+}
+
+type protoDependencyTag struct {
+	blueprint.BaseDependencyTag
+	name string
+}
+
+var ProtoPluginDepTag = protoDependencyTag{name: "plugin"}
+
+func ProtoDeps(ctx BottomUpMutatorContext, p *ProtoProperties) {
+	if String(p.Proto.Plugin) != "" && String(p.Proto.Type) != "" {
+		ctx.ModuleErrorf("only one of proto.type and proto.plugin can be specified.")
+	}
+
+	if plugin := String(p.Proto.Plugin); plugin != "" {
+		ctx.AddFarVariationDependencies([]blueprint.Variation{
+			{Mutator: "arch", Variation: ctx.Config().BuildOsVariant},
+		}, ProtoPluginDepTag, "protoc-gen-"+plugin)
+	}
 }
 
 func GetProtoFlags(ctx ModuleContext, p *ProtoProperties) ProtoFlags {
-	var protoFlags []string
+	var flags []string
+	var deps Paths
+
 	if len(p.Proto.Local_include_dirs) > 0 {
 		localProtoIncludeDirs := PathsForModuleSrc(ctx, p.Proto.Local_include_dirs)
-		protoFlags = append(protoFlags, JoinWithPrefix(localProtoIncludeDirs.Strings(), "-I"))
+		flags = append(flags, JoinWithPrefix(localProtoIncludeDirs.Strings(), "-I"))
 	}
 	if len(p.Proto.Include_dirs) > 0 {
 		rootProtoIncludeDirs := PathsForSource(ctx, p.Proto.Include_dirs)
-		protoFlags = append(protoFlags, JoinWithPrefix(rootProtoIncludeDirs.Strings(), "-I"))
+		flags = append(flags, JoinWithPrefix(rootProtoIncludeDirs.Strings(), "-I"))
+	}
+
+	ctx.VisitDirectDepsWithTag(ProtoPluginDepTag, func(dep Module) {
+		if hostTool, ok := dep.(HostToolProvider); !ok || !hostTool.HostToolPath().Valid() {
+			ctx.PropertyErrorf("proto.plugin", "module %q is not a host tool provider",
+				ctx.OtherModuleName(dep))
+		} else {
+			plugin := String(p.Proto.Plugin)
+			deps = append(deps, hostTool.HostToolPath().Path())
+			flags = append(flags, "--plugin=protoc-gen-"+plugin+"="+hostTool.HostToolPath().String())
+		}
+	})
+
+	var protoOutFlag string
+	if plugin := String(p.Proto.Plugin); plugin != "" {
+		protoOutFlag = "--" + plugin + "_out"
 	}
 
 	return ProtoFlags{
-		Flags:                 protoFlags,
+		Flags:                 flags,
+		Deps:                  deps,
+		OutTypeFlag:           protoOutFlag,
 		CanonicalPathFromRoot: proptools.BoolDefault(p.Proto.Canonical_path_from_root, true),
 		Dir:                   PathForModuleGen(ctx, "proto"),
 		SubDir:                PathForModuleGen(ctx, "proto", ctx.ModuleDir()),
@@ -61,6 +102,9 @@
 		// Proto generator type.  C++: full or lite.  Java: micro, nano, stream, or lite.
 		Type *string `android:"arch_variant"`
 
+		// Proto plugin to use as the generator.  Must be a cc_binary_host module.
+		Plugin *string `android:"arch_variant"`
+
 		// list of directories that will be added to the protoc include paths.
 		Include_dirs []string
 
diff --git a/cc/builder.go b/cc/builder.go
index 6b139f4..24c9377 100644
--- a/cc/builder.go
+++ b/cc/builder.go
@@ -260,7 +260,6 @@
 	stripAddGnuDebuglink   bool
 	stripUseGnuStrip       bool
 
-	protoDeps        android.Paths
 	proto            android.ProtoFlags
 	protoC           bool
 	protoOptionsFile bool
diff --git a/cc/cc.go b/cc/cc.go
index 8e55553..0668fd9 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -163,7 +163,6 @@
 	GroupStaticLibs bool
 
 	proto            android.ProtoFlags
-	protoDeps        android.Paths
 	protoC           bool // Whether to use C instead of C++
 	protoOptionsFile bool // Whether to look for a .options file next to the .proto
 }
@@ -1594,6 +1593,10 @@
 			return
 		}
 
+		if depTag == android.ProtoPluginDepTag {
+			return
+		}
+
 		if dep.Target().Os != ctx.Os() {
 			ctx.ModuleErrorf("OS mismatch between %q and %q", ctx.ModuleName(), depName)
 			return
diff --git a/cc/cc_test.go b/cc/cc_test.go
index 8c0bcfe..05d74b9 100644
--- a/cc/cc_test.go
+++ b/cc/cc_test.go
@@ -54,6 +54,7 @@
 func createTestContext(t *testing.T, config android.Config, bp string, os android.OsType) *android.TestContext {
 	ctx := android.NewTestArchContext()
 	ctx.RegisterModuleType("cc_binary", android.ModuleFactoryAdaptor(BinaryFactory))
+	ctx.RegisterModuleType("cc_binary_host", android.ModuleFactoryAdaptor(binaryHostFactory))
 	ctx.RegisterModuleType("cc_library", android.ModuleFactoryAdaptor(LibraryFactory))
 	ctx.RegisterModuleType("cc_library_shared", android.ModuleFactoryAdaptor(LibrarySharedFactory))
 	ctx.RegisterModuleType("cc_library_static", android.ModuleFactoryAdaptor(LibraryStaticFactory))
diff --git a/cc/compiler.go b/cc/compiler.go
index fe46a3c..f9af4d8 100644
--- a/cc/compiler.go
+++ b/cc/compiler.go
@@ -221,6 +221,7 @@
 	deps.GeneratedSources = append(deps.GeneratedSources, compiler.Properties.Generated_sources...)
 	deps.GeneratedHeaders = append(deps.GeneratedHeaders, compiler.Properties.Generated_headers...)
 
+	android.ProtoDeps(ctx, &compiler.Proto)
 	if compiler.hasSrcExt(".proto") {
 		deps = protoDeps(ctx, deps, &compiler.Proto, Bool(compiler.Properties.Proto.Static))
 	}
diff --git a/cc/proto.go b/cc/proto.go
index 5a96ae7..f818edc 100644
--- a/cc/proto.go
+++ b/cc/proto.go
@@ -39,7 +39,7 @@
 		headerFile = android.PathForModuleGen(ctx, "proto", pathtools.ReplaceExtension(rel, "pb.h"))
 	}
 
-	protoDeps := flags.protoDeps
+	protoDeps := flags.proto.Deps
 	if flags.protoOptionsFile {
 		optionsFile := pathtools.ReplaceExtension(protoFile.String(), "options")
 		optionsPath := android.PathForSource(ctx, optionsFile)
@@ -59,53 +59,55 @@
 	return ccFile, headerFile
 }
 
-func protoDeps(ctx BaseModuleContext, deps Deps, p *android.ProtoProperties, static bool) Deps {
+func protoDeps(ctx DepsContext, deps Deps, p *android.ProtoProperties, static bool) Deps {
 	var lib string
 
-	switch String(p.Proto.Type) {
-	case "full":
-		if ctx.useSdk() {
-			lib = "libprotobuf-cpp-full-ndk"
+	if String(p.Proto.Plugin) == "" {
+		switch String(p.Proto.Type) {
+		case "full":
+			if ctx.useSdk() {
+				lib = "libprotobuf-cpp-full-ndk"
+				static = true
+			} else {
+				lib = "libprotobuf-cpp-full"
+			}
+		case "lite", "":
+			if ctx.useSdk() {
+				lib = "libprotobuf-cpp-lite-ndk"
+				static = true
+			} else {
+				lib = "libprotobuf-cpp-lite"
+			}
+		case "nanopb-c":
+			lib = "libprotobuf-c-nano"
 			static = true
-		} else {
-			lib = "libprotobuf-cpp-full"
-		}
-	case "lite", "":
-		if ctx.useSdk() {
-			lib = "libprotobuf-cpp-lite-ndk"
+		case "nanopb-c-enable_malloc":
+			lib = "libprotobuf-c-nano-enable_malloc"
 			static = true
-		} else {
-			lib = "libprotobuf-cpp-lite"
+		case "nanopb-c-16bit":
+			lib = "libprotobuf-c-nano-16bit"
+			static = true
+		case "nanopb-c-enable_malloc-16bit":
+			lib = "libprotobuf-c-nano-enable_malloc-16bit"
+			static = true
+		case "nanopb-c-32bit":
+			lib = "libprotobuf-c-nano-32bit"
+			static = true
+		case "nanopb-c-enable_malloc-32bit":
+			lib = "libprotobuf-c-nano-enable_malloc-32bit"
+			static = true
+		default:
+			ctx.PropertyErrorf("proto.type", "unknown proto type %q",
+				String(p.Proto.Type))
 		}
-	case "nanopb-c":
-		lib = "libprotobuf-c-nano"
-		static = true
-	case "nanopb-c-enable_malloc":
-		lib = "libprotobuf-c-nano-enable_malloc"
-		static = true
-	case "nanopb-c-16bit":
-		lib = "libprotobuf-c-nano-16bit"
-		static = true
-	case "nanopb-c-enable_malloc-16bit":
-		lib = "libprotobuf-c-nano-enable_malloc-16bit"
-		static = true
-	case "nanopb-c-32bit":
-		lib = "libprotobuf-c-nano-32bit"
-		static = true
-	case "nanopb-c-enable_malloc-32bit":
-		lib = "libprotobuf-c-nano-enable_malloc-32bit"
-		static = true
-	default:
-		ctx.PropertyErrorf("proto.type", "unknown proto type %q",
-			String(p.Proto.Type))
-	}
 
-	if static {
-		deps.StaticLibs = append(deps.StaticLibs, lib)
-		deps.ReexportStaticLibHeaders = append(deps.ReexportStaticLibHeaders, lib)
-	} else {
-		deps.SharedLibs = append(deps.SharedLibs, lib)
-		deps.ReexportSharedLibHeaders = append(deps.ReexportSharedLibHeaders, lib)
+		if static {
+			deps.StaticLibs = append(deps.StaticLibs, lib)
+			deps.ReexportStaticLibHeaders = append(deps.ReexportStaticLibHeaders, lib)
+		} else {
+			deps.SharedLibs = append(deps.SharedLibs, lib)
+			deps.ReexportSharedLibHeaders = append(deps.ReexportSharedLibHeaders, lib)
+		}
 	}
 
 	return deps
@@ -120,33 +122,35 @@
 	}
 	flags.GlobalFlags = append(flags.GlobalFlags, "-I"+flags.proto.Dir.String())
 
-	var plugin string
+	if String(p.Proto.Plugin) == "" {
+		var plugin string
 
-	switch String(p.Proto.Type) {
-	case "nanopb-c", "nanopb-c-enable_malloc", "nanopb-c-16bit", "nanopb-c-enable_malloc-16bit", "nanopb-c-32bit", "nanopb-c-enable_malloc-32bit":
-		flags.protoC = true
-		flags.protoOptionsFile = true
-		flags.proto.OutTypeFlag = "--nanopb_out"
-		plugin = "protoc-gen-nanopb"
-	case "full":
-		flags.proto.OutTypeFlag = "--cpp_out"
-	case "lite":
-		flags.proto.OutTypeFlag = "--cpp_out"
-		flags.proto.OutParams = append(flags.proto.OutParams, "lite")
-	case "":
-		// TODO(b/119714316): this should be equivalent to "lite" in
-		// order to match protoDeps, but some modules are depending on
-		// this behavior
-		flags.proto.OutTypeFlag = "--cpp_out"
-	default:
-		ctx.PropertyErrorf("proto.type", "unknown proto type %q",
-			String(p.Proto.Type))
-	}
+		switch String(p.Proto.Type) {
+		case "nanopb-c", "nanopb-c-enable_malloc", "nanopb-c-16bit", "nanopb-c-enable_malloc-16bit", "nanopb-c-32bit", "nanopb-c-enable_malloc-32bit":
+			flags.protoC = true
+			flags.protoOptionsFile = true
+			flags.proto.OutTypeFlag = "--nanopb_out"
+			plugin = "protoc-gen-nanopb"
+		case "full":
+			flags.proto.OutTypeFlag = "--cpp_out"
+		case "lite":
+			flags.proto.OutTypeFlag = "--cpp_out"
+			flags.proto.OutParams = append(flags.proto.OutParams, "lite")
+		case "":
+			// TODO(b/119714316): this should be equivalent to "lite" in
+			// order to match protoDeps, but some modules are depending on
+			// this behavior
+			flags.proto.OutTypeFlag = "--cpp_out"
+		default:
+			ctx.PropertyErrorf("proto.type", "unknown proto type %q",
+				String(p.Proto.Type))
+		}
 
-	if plugin != "" {
-		path := ctx.Config().HostToolPath(ctx, plugin)
-		flags.protoDeps = append(flags.protoDeps, path)
-		flags.proto.Flags = append(flags.proto.Flags, "--plugin="+path.String())
+		if plugin != "" {
+			path := ctx.Config().HostToolPath(ctx, plugin)
+			flags.proto.Deps = append(flags.proto.Deps, path)
+			flags.proto.Flags = append(flags.proto.Flags, "--plugin="+path.String())
+		}
 	}
 
 	return flags
diff --git a/cc/proto_test.go b/cc/proto_test.go
index 6fee924..4f0de78 100644
--- a/cc/proto_test.go
+++ b/cc/proto_test.go
@@ -17,6 +17,8 @@
 import (
 	"strings"
 	"testing"
+
+	"android/soong/android"
 )
 
 func TestProto(t *testing.T) {
@@ -33,4 +35,37 @@
 			t.Errorf("expected '--cpp_out' in %q", cmd)
 		}
 	})
+
+	t.Run("plugin", func(t *testing.T) {
+		ctx := testCc(t, `
+		cc_binary_host {
+			name: "protoc-gen-foobar",
+			stl: "none",
+		}
+
+		cc_library_shared {
+			name: "libfoo",
+			srcs: ["a.proto"],
+			proto: {
+				plugin: "foobar",
+			},
+		}`)
+
+		buildOS := android.BuildOs.String()
+
+		proto := ctx.ModuleForTests("libfoo", "android_arm_armv7-a-neon_core_shared").Output("proto/a.pb.cc")
+		foobar := ctx.ModuleForTests("protoc-gen-foobar", buildOS+"_x86_64")
+
+		cmd := proto.RuleParams.Command
+		if w := "--foobar_out="; !strings.Contains(cmd, w) {
+			t.Errorf("expected %q in %q", w, cmd)
+		}
+
+		foobarPath := foobar.Module().(android.HostToolProvider).HostToolPath().String()
+
+		if w := "--plugin=protoc-gen-foobar=" + foobarPath; !strings.Contains(cmd, w) {
+			t.Errorf("expected %q in %q", w, cmd)
+		}
+	})
+
 }
diff --git a/cc/util.go b/cc/util.go
index 30a77a4..5dcbaef 100644
--- a/cc/util.go
+++ b/cc/util.go
@@ -84,7 +84,6 @@
 
 		groupStaticLibs: in.GroupStaticLibs,
 
-		protoDeps:        in.protoDeps,
 		proto:            in.proto,
 		protoC:           in.protoC,
 		protoOptionsFile: in.protoOptionsFile,
diff --git a/genrule/genrule.go b/genrule/genrule.go
index 32acd8c..e259b1d 100644
--- a/genrule/genrule.go
+++ b/genrule/genrule.go
@@ -49,8 +49,10 @@
 	GeneratedDeps() android.Paths
 }
 
+// Alias for android.HostToolProvider
+// Deprecated: use android.HostToolProvider instead.
 type HostToolProvider interface {
-	HostToolPath() android.OptionalPath
+	android.HostToolProvider
 }
 
 type hostToolDependencyTag struct {
@@ -193,7 +195,7 @@
 				tool := ctx.OtherModuleName(module)
 				var path android.OptionalPath
 
-				if t, ok := module.(HostToolProvider); ok {
+				if t, ok := module.(android.HostToolProvider); ok {
 					if !t.(android.Module).Enabled() {
 						if ctx.Config().AllowMissingDependencies() {
 							ctx.AddMissingDependencies([]string{tool})
diff --git a/genrule/genrule_test.go b/genrule/genrule_test.go
index 19b22f7..5cb51b8 100644
--- a/genrule/genrule_test.go
+++ b/genrule/genrule_test.go
@@ -527,4 +527,4 @@
 	return android.OptionalPathForPath(t.outputFile)
 }
 
-var _ HostToolProvider = (*testTool)(nil)
+var _ android.HostToolProvider = (*testTool)(nil)
diff --git a/java/gen.go b/java/gen.go
index 8362556..500d887 100644
--- a/java/gen.go
+++ b/java/gen.go
@@ -118,7 +118,7 @@
 			javaFile := genLogtags(ctx, srcFile)
 			outSrcFiles = append(outSrcFiles, javaFile)
 		case ".proto":
-			srcJarFile := genProto(ctx, srcFile, flags)
+			srcJarFile := genProto(ctx, srcFile, flags.proto)
 			outSrcFiles = append(outSrcFiles, srcJarFile)
 		case ".sysprop":
 			srcJarFile := genSysprop(ctx, srcFile)
diff --git a/java/java.go b/java/java.go
index beee1a5..0417dee 100644
--- a/java/java.go
+++ b/java/java.go
@@ -481,6 +481,7 @@
 		{Mutator: "arch", Variation: ctx.Config().BuildOsCommonVariant},
 	}, pluginTag, j.properties.Plugins...)
 
+	android.ProtoDeps(ctx, &j.protoProperties)
 	if j.hasSrcExt(".proto") {
 		protoDeps(ctx, &j.protoProperties)
 	}
@@ -768,12 +769,6 @@
 				deps.classpath = append(deps.classpath, dep.Srcs()...)
 				deps.staticJars = append(deps.staticJars, dep.Srcs()...)
 				deps.staticHeaderJars = append(deps.staticHeaderJars, dep.Srcs()...)
-			case android.DefaultsDepTag, android.SourceDepTag:
-				// Nothing to do
-			case publicApiFileTag, systemApiFileTag, testApiFileTag:
-				// Nothing to do
-			default:
-				ctx.ModuleErrorf("dependency on genrule %q may only be in srcs, libs, or static_libs", otherName)
 			}
 		default:
 			switch tag {
diff --git a/java/proto.go b/java/proto.go
index 8de9e26..37de1d2 100644
--- a/java/proto.go
+++ b/java/proto.go
@@ -18,7 +18,7 @@
 	"android/soong/android"
 )
 
-func genProto(ctx android.ModuleContext, protoFile android.Path, flags javaBuilderFlags) android.Path {
+func genProto(ctx android.ModuleContext, protoFile android.Path, flags android.ProtoFlags) android.Path {
 	srcJarFile := android.GenPathWithExt(ctx, "proto", protoFile, "srcjar")
 
 	outDir := srcJarFile.ReplaceExtension(ctx, "tmp")
@@ -29,7 +29,7 @@
 	rule.Command().Text("rm -rf").Flag(outDir.String())
 	rule.Command().Text("mkdir -p").Flag(outDir.String())
 
-	android.ProtoRule(ctx, rule, protoFile, flags.proto, nil, outDir, depFile, nil)
+	android.ProtoRule(ctx, rule, protoFile, flags, flags.Deps, outDir, depFile, nil)
 
 	// Proto generated java files have an unknown package name in the path, so package the entire output directory
 	// into a srcjar.
@@ -48,22 +48,24 @@
 }
 
 func protoDeps(ctx android.BottomUpMutatorContext, p *android.ProtoProperties) {
-	switch String(p.Proto.Type) {
-	case "micro":
-		ctx.AddVariationDependencies(nil, staticLibTag, "libprotobuf-java-micro")
-	case "nano":
-		ctx.AddVariationDependencies(nil, staticLibTag, "libprotobuf-java-nano")
-	case "lite", "":
-		ctx.AddVariationDependencies(nil, staticLibTag, "libprotobuf-java-lite")
-	case "full":
-		if ctx.Host() {
-			ctx.AddVariationDependencies(nil, staticLibTag, "libprotobuf-java-full")
-		} else {
-			ctx.PropertyErrorf("proto.type", "full java protos only supported on the host")
+	if String(p.Proto.Plugin) == "" {
+		switch String(p.Proto.Type) {
+		case "micro":
+			ctx.AddVariationDependencies(nil, staticLibTag, "libprotobuf-java-micro")
+		case "nano":
+			ctx.AddVariationDependencies(nil, staticLibTag, "libprotobuf-java-nano")
+		case "lite", "":
+			ctx.AddVariationDependencies(nil, staticLibTag, "libprotobuf-java-lite")
+		case "full":
+			if ctx.Host() {
+				ctx.AddVariationDependencies(nil, staticLibTag, "libprotobuf-java-full")
+			} else {
+				ctx.PropertyErrorf("proto.type", "full java protos only supported on the host")
+			}
+		default:
+			ctx.PropertyErrorf("proto.type", "unknown proto type %q",
+				String(p.Proto.Type))
 		}
-	default:
-		ctx.PropertyErrorf("proto.type", "unknown proto type %q",
-			String(p.Proto.Type))
 	}
 }
 
@@ -72,19 +74,21 @@
 
 	flags.proto = android.GetProtoFlags(ctx, p)
 
-	switch String(p.Proto.Type) {
-	case "micro":
-		flags.proto.OutTypeFlag = "--javamicro_out"
-	case "nano":
-		flags.proto.OutTypeFlag = "--javanano_out"
-	case "lite":
-		flags.proto.OutTypeFlag = "--java_out"
-		flags.proto.OutParams = append(flags.proto.OutParams, "lite")
-	case "full", "":
-		flags.proto.OutTypeFlag = "--java_out"
-	default:
-		ctx.PropertyErrorf("proto.type", "unknown proto type %q",
-			String(p.Proto.Type))
+	if String(p.Proto.Plugin) == "" {
+		switch String(p.Proto.Type) {
+		case "micro":
+			flags.proto.OutTypeFlag = "--javamicro_out"
+		case "nano":
+			flags.proto.OutTypeFlag = "--javanano_out"
+		case "lite":
+			flags.proto.OutTypeFlag = "--java_out"
+			flags.proto.OutParams = append(flags.proto.OutParams, "lite")
+		case "full", "":
+			flags.proto.OutTypeFlag = "--java_out"
+		default:
+			ctx.PropertyErrorf("proto.type", "unknown proto type %q",
+				String(p.Proto.Type))
+		}
 	}
 
 	flags.proto.OutParams = append(flags.proto.OutParams, j.Proto.Output_params...)
diff --git a/python/proto.go b/python/proto.go
index 813e91d..b3ffaa6 100644
--- a/python/proto.go
+++ b/python/proto.go
@@ -29,7 +29,7 @@
 	rule.Command().Text("rm -rf").Flag(outDir.String())
 	rule.Command().Text("mkdir -p").Flag(outDir.String())
 
-	android.ProtoRule(ctx, rule, protoFile, flags, nil, outDir, depFile, nil)
+	android.ProtoRule(ctx, rule, protoFile, flags, flags.Deps, outDir, depFile, nil)
 
 	// Proto generated python files have an unknown package name in the path, so package the entire output directory
 	// into a srcszip.
diff --git a/python/python.go b/python/python.go
index 3c3c396..ad08909 100644
--- a/python/python.go
+++ b/python/python.go
@@ -288,6 +288,8 @@
 }
 
 func (p *Module) DepsMutator(ctx android.BottomUpMutatorContext) {
+	android.ProtoDeps(ctx, &p.protoProperties)
+
 	if p.hasSrcExt(ctx, protoExt) && p.Name() != "libprotobuf-python" {
 		ctx.AddVariationDependencies(nil, pythonLibTag, "libprotobuf-python")
 	}