Add Code Metadata rule to soong/testing.

This Cl adds a new rule to Soong to generate code ownership metadata. Also, this CL adds a provider in the Java SDK library to provide generated source files to the Code_metadata rule. Will add providers to other libraries in the future changes.

Bug: 296873595
Change-Id: Ic2e43aa9b161231fea4416d1f0d36b778361d7c5

testing/code_metadata.go

@@ -0,0 +1,139 @@
+// Copyright 2020 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package testing
+
+import (
+	"path/filepath"
+
+	"android/soong/android"
+	"android/soong/testing/code_metadata_internal_proto"
+	"github.com/google/blueprint"
+	"google.golang.org/protobuf/proto"
+)
+
+func CodeMetadataFactory() android.Module {
+	module := &CodeMetadataModule{}
+
+	android.InitAndroidModule(module)
+	android.InitDefaultableModule(module)
+	module.AddProperties(&module.properties)
+
+	return module
+}
+
+type CodeMetadataModule struct {
+	android.ModuleBase
+	android.DefaultableModuleBase
+	android.BazelModuleBase
+
+	// Properties for "code_metadata"
+	properties struct {
+		// Specifies the name of the code_config.
+		Name string
+		// Specifies the team ID.
+		TeamId string
+		// Specifies the list of modules that this code_metadata covers.
+		Code []string
+		// An optional field to specify if multiple ownerships for source files is allowed.
+		MultiOwnership bool
+	}
+}
+
+type codeDepTagType struct {
+	blueprint.BaseDependencyTag
+}
+
+var codeDepTag = codeDepTagType{}
+
+func (module *CodeMetadataModule) DepsMutator(ctx android.BottomUpMutatorContext) {
+	// Validate Properties
+	if len(module.properties.TeamId) == 0 {
+		ctx.PropertyErrorf(
+			"TeamId",
+			"Team Id not found in the code_metadata module. Hint: Maybe the teamId property hasn't been properly specified.",
+		)
+	}
+	if !isInt(module.properties.TeamId) {
+		ctx.PropertyErrorf(
+			"TeamId", "Invalid value for Team ID. The Team ID must be an integer.",
+		)
+	}
+	if len(module.properties.Code) == 0 {
+		ctx.PropertyErrorf(
+			"Code",
+			"Targets to be attributed cannot be empty. Hint: Maybe the code property hasn't been properly specified.",
+		)
+	}
+	ctx.AddDependency(ctx.Module(), codeDepTag, module.properties.Code...)
+}
+
+// Provider published by CodeMetadata
+type CodeMetadataProviderData struct {
+	IntermediatePath android.WritablePath
+}
+
+var CodeMetadataProviderKey = blueprint.NewProvider(CodeMetadataProviderData{})
+
+func (module *CodeMetadataModule) GenerateAndroidBuildActions(ctx android.ModuleContext) {
+	metadataList := make(
+		[]*code_metadata_internal_proto.CodeMetadataInternal_TargetOwnership, 0,
+		len(module.properties.Code),
+	)
+	bpFilePath := filepath.Join(ctx.ModuleDir(), ctx.BlueprintsFile())
+
+	for _, m := range ctx.GetDirectDepsWithTag(codeDepTag) {
+		targetName := m.Name()
+		var moduleSrcs android.Paths
+		if ctx.OtherModuleHasProvider(m, android.SrcsFileProviderKey) {
+			moduleSrcs = ctx.OtherModuleProvider(
+				m, android.SrcsFileProviderKey,
+			).(android.SrcsFileProviderData).SrcPaths
+		}
+		if module.properties.MultiOwnership {
+			metadata := &code_metadata_internal_proto.CodeMetadataInternal_TargetOwnership{
+				TargetName:     &targetName,
+				TrendyTeamId:   &module.properties.TeamId,
+				Path:           &bpFilePath,
+				MultiOwnership: &module.properties.MultiOwnership,
+				SourceFiles:    moduleSrcs.Strings(),
+			}
+			metadataList = append(metadataList, metadata)
+		} else {
+			metadata := &code_metadata_internal_proto.CodeMetadataInternal_TargetOwnership{
+				TargetName:   &targetName,
+				TrendyTeamId: &module.properties.TeamId,
+				Path:         &bpFilePath,
+				SourceFiles:  moduleSrcs.Strings(),
+			}
+			metadataList = append(metadataList, metadata)
+		}
+
+	}
+	codeMetadata := &code_metadata_internal_proto.CodeMetadataInternal{TargetOwnershipList: metadataList}
+	protoData, err := proto.Marshal(codeMetadata)
+	if err != nil {
+		ctx.ModuleErrorf("Error marshaling code metadata: %s", err.Error())
+		return
+	}
+	intermediatePath := android.PathForModuleOut(
+		ctx, "intermediateCodeMetadata.pb",
+	)
+	android.WriteFileRule(ctx, intermediatePath, string(protoData))
+
+	ctx.SetProvider(
+		CodeMetadataProviderKey,
+		CodeMetadataProviderData{IntermediatePath: intermediatePath},
+	)
+}