convert java proto libraries with bp2build

Allow java_libraries that depend on protobufs to be converted with
bp2build.

Bug: 215230097
Test: build/bazel/ci/bp2build.sh
Change-Id: I3ce52389e7e4e82755605ee277c1e527a6aebc6b

java/proto.go

@@ -19,6 +19,13 @@ import (
 	"strconv"
 
 	"android/soong/android"
+	"android/soong/bazel"
+
+	"github.com/google/blueprint/proptools"
+)
+
+const (
+	protoTypeDefault = "lite"
 )
 
 func genProto(ctx android.ModuleContext, protoFiles android.Paths, flags android.ProtoFlags) android.Paths {
@@ -134,3 +141,52 @@ func protoFlags(ctx android.ModuleContext, j *CommonProperties, p *android.Proto
 
 	return flags
 }
+
+type protoAttributes struct {
+	Deps bazel.LabelListAttribute
+}
+
+func bp2buildProto(ctx android.Bp2buildMutatorContext, m *Module, protoSrcs bazel.LabelListAttribute) *bazel.Label {
+	protoInfo, ok := android.Bp2buildProtoProperties(ctx, &m.ModuleBase, protoSrcs)
+	if !ok {
+		return nil
+	}
+
+	typ := proptools.StringDefault(protoInfo.Type, protoTypeDefault)
+	var rule_class string
+	suffix := "_java_proto"
+	switch typ {
+	case "nano":
+		suffix += "_nano"
+		rule_class = "java_nano_proto_library"
+	case "micro":
+		suffix += "_micro"
+		rule_class = "java_micro_proto_library"
+	case "lite":
+		suffix += "_lite"
+		rule_class = "java_lite_proto_library"
+	case "stream":
+		suffix += "_stream"
+		rule_class = "java_stream_proto_library"
+	case "full":
+		rule_class = "java_proto_library"
+	default:
+		ctx.PropertyErrorf("proto.type", "cannot handle conversion at this time: %q", typ)
+	}
+
+	protoLabel := bazel.Label{Label: ":" + m.Name() + "_proto"}
+	var protoAttrs protoAttributes
+	protoAttrs.Deps.SetValue(bazel.LabelList{Includes: []bazel.Label{protoLabel}})
+
+	name := m.Name() + suffix
+
+	ctx.CreateBazelTargetModule(
+		bazel.BazelTargetModuleProperties{
+			Rule_class:        rule_class,
+			Bzl_load_location: "//build/bazel/rules/java:proto.bzl",
+		},
+		android.CommonAttributes{Name: name},
+		&protoAttrs)
+
+	return &bazel.Label{Label: ":" + name}
+}