bp2build: support full/lite protos in cc libs

Test: bp2build.sh
Bug: 200601772
Change-Id: I3a7e00546726bc63b5eb8d5604557c5988a5320b

android/proto.go

@@ -15,12 +15,17 @@
 package android
 
 import (
+	"android/soong/bazel"
 	"strings"
 
 	"github.com/google/blueprint"
 	"github.com/google/blueprint/proptools"
 )
 
+const (
+	canonicalPathFromRootDefault = true
+)
+
 // TODO(ccross): protos are often used to communicate between multiple modules.  If the only
 // way to convert a proto to source is to reference it as a source file, and external modules cannot
 // reference source files in other modules, then every module that owns a proto file will need to
@@ -90,7 +95,7 @@ func GetProtoFlags(ctx ModuleContext, p *ProtoProperties) ProtoFlags {
 		Flags:                 flags,
 		Deps:                  deps,
 		OutTypeFlag:           protoOutFlag,
-		CanonicalPathFromRoot: proptools.BoolDefault(p.Proto.Canonical_path_from_root, true),
+		CanonicalPathFromRoot: proptools.BoolDefault(p.Proto.Canonical_path_from_root, canonicalPathFromRootDefault),
 		Dir:                   PathForModuleGen(ctx, "proto"),
 		SubDir:                PathForModuleGen(ctx, "proto", ctx.ModuleDir()),
 	}
@@ -146,3 +151,57 @@ func ProtoRule(rule *RuleBuilder, protoFile Path, flags ProtoFlags, deps Paths,
 	rule.Command().
 		BuiltTool("dep_fixer").Flag(depFile.String())
 }
+
+// Bp2buildProtoInfo contains information necessary to pass on to language specific conversion.
+type Bp2buildProtoInfo struct {
+	Type *string
+	Name string
+}
+
+type protoAttrs struct {
+	Srcs                bazel.LabelListAttribute
+	Strip_import_prefix *string
+}
+
+// Bp2buildProtoProperties converts proto properties, creating a proto_library and returning the
+// information necessary for language-specific handling.
+func Bp2buildProtoProperties(ctx Bp2buildMutatorContext, module Module, srcs bazel.LabelListAttribute) (Bp2buildProtoInfo, bool) {
+	var info Bp2buildProtoInfo
+	if srcs.IsEmpty() {
+		return info, false
+	}
+	m := module.base()
+
+	info.Name = m.Name() + "_proto"
+	attrs := protoAttrs{
+		Srcs: srcs,
+	}
+
+	for axis, configToProps := range m.GetArchVariantProperties(ctx, &ProtoProperties{}) {
+		for _, rawProps := range configToProps {
+			var props *ProtoProperties
+			var ok bool
+			if props, ok = rawProps.(*ProtoProperties); !ok {
+				ctx.ModuleErrorf("Could not cast ProtoProperties to expected type")
+			}
+			if axis == bazel.NoConfigAxis {
+				info.Type = props.Proto.Type
+
+				if proptools.BoolDefault(props.Proto.Canonical_path_from_root, canonicalPathFromRootDefault) {
+					// an empty string indicates to strips the package path
+					path := ""
+					attrs.Strip_import_prefix = &path
+				}
+			} else if props.Proto.Type != info.Type && props.Proto.Type != nil {
+				ctx.ModuleErrorf("Cannot handle arch-variant types for protos at this time.")
+			}
+		}
+	}
+
+	ctx.CreateBazelTargetModule(
+		bazel.BazelTargetModuleProperties{Rule_class: "proto_library"},
+		CommonAttributes{Name: info.Name},
+		&attrs)
+
+	return info, true
+}