|  | // Copyright 2021 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 java | 
|  |  | 
|  | import ( | 
|  | "android/soong/android" | 
|  | "android/soong/dexpreopt" | 
|  | ) | 
|  |  | 
|  | func init() { | 
|  | registerPlatformBootclasspathBuildComponents(android.InitRegistrationContext) | 
|  | } | 
|  |  | 
|  | func registerPlatformBootclasspathBuildComponents(ctx android.RegistrationContext) { | 
|  | ctx.RegisterModuleType("platform_bootclasspath", platformBootclasspathFactory) | 
|  | } | 
|  |  | 
|  | // The tags used for the dependencies between the platform bootclasspath and any configured boot | 
|  | // jars. | 
|  | var ( | 
|  | platformBootclasspathArtBootJarDepTag  = bootclasspathDependencyTag{name: "art-boot-jar"} | 
|  | platformBootclasspathBootJarDepTag     = bootclasspathDependencyTag{name: "platform-boot-jar"} | 
|  | platformBootclasspathApexBootJarDepTag = bootclasspathDependencyTag{name: "apex-boot-jar"} | 
|  | platformBootclasspathImplLibDepTag     = dependencyTag{name: "impl-lib-tag"} | 
|  | ) | 
|  |  | 
|  | type platformBootclasspathModule struct { | 
|  | android.ModuleBase | 
|  | ClasspathFragmentBase | 
|  |  | 
|  | properties platformBootclasspathProperties | 
|  |  | 
|  | // The apex:module pairs obtained from the configured modules. | 
|  | configuredModules []android.Module | 
|  |  | 
|  | // The apex:module pairs obtained from the fragments. | 
|  | fragments []android.Module | 
|  |  | 
|  | // Path to the monolithic hiddenapi-flags.csv file. | 
|  | hiddenAPIFlagsCSV android.OutputPath | 
|  |  | 
|  | // Path to the monolithic hiddenapi-index.csv file. | 
|  | hiddenAPIIndexCSV android.OutputPath | 
|  |  | 
|  | // Path to the monolithic hiddenapi-unsupported.csv file. | 
|  | hiddenAPIMetadataCSV android.OutputPath | 
|  | } | 
|  |  | 
|  | type platformBootclasspathProperties struct { | 
|  | BootclasspathFragmentsDepsProperties | 
|  |  | 
|  | HiddenAPIFlagFileProperties | 
|  | } | 
|  |  | 
|  | func platformBootclasspathFactory() android.Module { | 
|  | m := &platformBootclasspathModule{} | 
|  | m.AddProperties(&m.properties) | 
|  | initClasspathFragment(m, BOOTCLASSPATH) | 
|  | android.InitAndroidArchModule(m, android.DeviceSupported, android.MultilibCommon) | 
|  | return m | 
|  | } | 
|  |  | 
|  | func (b *platformBootclasspathModule) AndroidMkEntries() (entries []android.AndroidMkEntries) { | 
|  | entries = append(entries, android.AndroidMkEntries{ | 
|  | Class: "FAKE", | 
|  | // Need at least one output file in order for this to take effect. | 
|  | OutputFile: android.OptionalPathForPath(b.hiddenAPIFlagsCSV), | 
|  | Include:    "$(BUILD_PHONY_PACKAGE)", | 
|  | }) | 
|  | entries = append(entries, b.classpathFragmentBase().androidMkEntries()...) | 
|  | return | 
|  | } | 
|  |  | 
|  | func (b *platformBootclasspathModule) DepsMutator(ctx android.BottomUpMutatorContext) { | 
|  | // Create a dependency on all_apex_contributions to determine the selected mainline module | 
|  | ctx.AddDependency(ctx.Module(), apexContributionsMetadataDepTag, "all_apex_contributions") | 
|  |  | 
|  | b.hiddenAPIDepsMutator(ctx) | 
|  |  | 
|  | if !dexpreopt.IsDex2oatNeeded(ctx) { | 
|  | return | 
|  | } | 
|  |  | 
|  | // Add a dependency onto the dex2oat tool which is needed for creating the boot image. The | 
|  | // path is retrieved from the dependency by GetGlobalSoongConfig(ctx). | 
|  | dexpreopt.RegisterToolDeps(ctx) | 
|  | } | 
|  |  | 
|  | func (b *platformBootclasspathModule) hiddenAPIDepsMutator(ctx android.BottomUpMutatorContext) { | 
|  | if ctx.Config().DisableHiddenApiChecks() { | 
|  | return | 
|  | } | 
|  |  | 
|  | // Add dependencies onto the stub lib modules. | 
|  | apiLevelToStubLibModules := hiddenAPIComputeMonolithicStubLibModules(ctx.Config()) | 
|  | hiddenAPIAddStubLibDependencies(ctx, apiLevelToStubLibModules) | 
|  | } | 
|  |  | 
|  | func (b *platformBootclasspathModule) BootclasspathDepsMutator(ctx android.BottomUpMutatorContext) { | 
|  | // Add dependencies on all the ART jars. | 
|  | global := dexpreopt.GetGlobalConfig(ctx) | 
|  | addDependenciesOntoSelectedBootImageApexes(ctx, "com.android.art") | 
|  |  | 
|  | var bootImageModuleNames []string | 
|  |  | 
|  | // TODO: b/308174306 - Remove the mechanism of depending on the java_sdk_library(_import) directly | 
|  | addDependenciesOntoBootImageModules(ctx, global.ArtApexJars, platformBootclasspathArtBootJarDepTag) | 
|  | bootImageModuleNames = append(bootImageModuleNames, global.ArtApexJars.CopyOfJars()...) | 
|  |  | 
|  | // Add dependencies on all the non-updatable jars, which are on the platform or in non-updatable | 
|  | // APEXes. | 
|  | platformJars := b.platformJars(ctx) | 
|  | addDependenciesOntoBootImageModules(ctx, platformJars, platformBootclasspathBootJarDepTag) | 
|  | bootImageModuleNames = append(bootImageModuleNames, platformJars.CopyOfJars()...) | 
|  |  | 
|  | // Add dependencies on all the updatable jars, except the ART jars. | 
|  | apexJars := dexpreopt.GetGlobalConfig(ctx).ApexBootJars | 
|  | apexes := []string{} | 
|  | for i := 0; i < apexJars.Len(); i++ { | 
|  | apexes = append(apexes, apexJars.Apex(i)) | 
|  | } | 
|  | addDependenciesOntoSelectedBootImageApexes(ctx, android.FirstUniqueStrings(apexes)...) | 
|  | // TODO: b/308174306 - Remove the mechanism of depending on the java_sdk_library(_import) directly | 
|  | addDependenciesOntoBootImageModules(ctx, apexJars, platformBootclasspathApexBootJarDepTag) | 
|  | bootImageModuleNames = append(bootImageModuleNames, apexJars.CopyOfJars()...) | 
|  |  | 
|  | // Add dependencies on all the fragments. | 
|  | b.properties.BootclasspathFragmentsDepsProperties.addDependenciesOntoFragments(ctx) | 
|  |  | 
|  | for _, bootImageModuleName := range bootImageModuleNames { | 
|  | implLibName := implLibraryModuleName(bootImageModuleName) | 
|  | if ctx.OtherModuleExists(implLibName) { | 
|  | ctx.AddFarVariationDependencies(nil, platformBootclasspathImplLibDepTag, implLibName) | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | func addDependenciesOntoBootImageModules(ctx android.BottomUpMutatorContext, modules android.ConfiguredJarList, tag bootclasspathDependencyTag) { | 
|  | for i := 0; i < modules.Len(); i++ { | 
|  | apex := modules.Apex(i) | 
|  | name := modules.Jar(i) | 
|  |  | 
|  | addDependencyOntoApexModulePair(ctx, apex, name, tag) | 
|  | } | 
|  | } | 
|  |  | 
|  | func (b *platformBootclasspathModule) GenerateAndroidBuildActions(ctx android.ModuleContext) { | 
|  | // Gather all the dependencies from the art, platform, and apex boot jars. | 
|  | artModules := gatherApexModulePairDepsWithTag(ctx, platformBootclasspathArtBootJarDepTag) | 
|  | platformModules := gatherApexModulePairDepsWithTag(ctx, platformBootclasspathBootJarDepTag) | 
|  | apexModules := gatherApexModulePairDepsWithTag(ctx, platformBootclasspathApexBootJarDepTag) | 
|  |  | 
|  | // Concatenate them all, in order as they would appear on the bootclasspath. | 
|  | var allModules []android.Module | 
|  | allModules = append(allModules, artModules...) | 
|  | allModules = append(allModules, platformModules...) | 
|  | allModules = append(allModules, apexModules...) | 
|  | b.configuredModules = allModules | 
|  |  | 
|  | // Do not add implLibModule to allModules as the impl lib is only used to collect the | 
|  | // transitive source files | 
|  | var implLibModule []android.Module | 
|  | ctx.VisitDirectDepsWithTag(implLibraryTag, func(m android.Module) { | 
|  | implLibModule = append(implLibModule, m) | 
|  | }) | 
|  |  | 
|  | var transitiveSrcFiles android.Paths | 
|  | for _, module := range append(allModules, implLibModule...) { | 
|  | if depInfo, ok := android.OtherModuleProvider(ctx, module, JavaInfoProvider); ok { | 
|  | transitiveSrcFiles = append(transitiveSrcFiles, depInfo.TransitiveSrcFiles.ToList()...) | 
|  | } | 
|  | } | 
|  | jarArgs := resourcePathsToJarArgs(transitiveSrcFiles) | 
|  | jarArgs = append(jarArgs, "-srcjar") // Move srcfiles to the right package | 
|  | srcjar := android.PathForModuleOut(ctx, ctx.ModuleName()+"-transitive.srcjar") | 
|  | TransformResourcesToJar(ctx, srcjar, jarArgs, transitiveSrcFiles) | 
|  |  | 
|  | // Gather all the fragments dependencies. | 
|  | b.fragments = gatherApexModulePairDepsWithTag(ctx, bootclasspathFragmentDepTag) | 
|  |  | 
|  | // Check the configuration of the boot modules. | 
|  | // ART modules are checked by the art-bootclasspath-fragment. | 
|  | b.checkPlatformModules(ctx, platformModules) | 
|  | b.checkApexModules(ctx, apexModules) | 
|  |  | 
|  | b.generateClasspathProtoBuildActions(ctx) | 
|  |  | 
|  | bootDexJarByModule := b.generateHiddenAPIBuildActions(ctx, b.configuredModules, b.fragments) | 
|  | buildRuleForBootJarsPackageCheck(ctx, bootDexJarByModule) | 
|  |  | 
|  | ctx.SetOutputFiles(android.Paths{b.hiddenAPIFlagsCSV}, "hiddenapi-flags.csv") | 
|  | ctx.SetOutputFiles(android.Paths{b.hiddenAPIIndexCSV}, "hiddenapi-index.csv") | 
|  | ctx.SetOutputFiles(android.Paths{b.hiddenAPIMetadataCSV}, "hiddenapi-metadata.csv") | 
|  | ctx.SetOutputFiles(android.Paths{srcjar}, ".srcjar") | 
|  | } | 
|  |  | 
|  | // Generate classpaths.proto config | 
|  | func (b *platformBootclasspathModule) generateClasspathProtoBuildActions(ctx android.ModuleContext) { | 
|  | configuredJars := b.configuredJars(ctx) | 
|  | // ART and platform boot jars must have a corresponding entry in DEX2OATBOOTCLASSPATH | 
|  | classpathJars := configuredJarListToClasspathJars(ctx, configuredJars, BOOTCLASSPATH, DEX2OATBOOTCLASSPATH) | 
|  | b.classpathFragmentBase().generateClasspathProtoBuildActions(ctx, configuredJars, classpathJars) | 
|  | b.classpathFragmentBase().installClasspathProto(ctx) | 
|  | } | 
|  |  | 
|  | func (b *platformBootclasspathModule) configuredJars(ctx android.ModuleContext) android.ConfiguredJarList { | 
|  | // Include all non APEX jars | 
|  | jars := b.platformJars(ctx) | 
|  |  | 
|  | // Include jars from APEXes that don't populate their classpath proto config. | 
|  | remainingJars := dexpreopt.GetGlobalConfig(ctx).ApexBootJars | 
|  | for _, fragment := range b.fragments { | 
|  | info, _ := android.OtherModuleProvider(ctx, fragment, ClasspathFragmentProtoContentInfoProvider) | 
|  | if info.ClasspathFragmentProtoGenerated { | 
|  | remainingJars = remainingJars.RemoveList(info.ClasspathFragmentProtoContents) | 
|  | } | 
|  | } | 
|  | for i := 0; i < remainingJars.Len(); i++ { | 
|  | jars = jars.Append(remainingJars.Apex(i), remainingJars.Jar(i)) | 
|  | } | 
|  |  | 
|  | return jars | 
|  | } | 
|  |  | 
|  | func (b *platformBootclasspathModule) platformJars(ctx android.PathContext) android.ConfiguredJarList { | 
|  | global := dexpreopt.GetGlobalConfig(ctx) | 
|  | return global.BootJars.RemoveList(global.ArtApexJars) | 
|  | } | 
|  |  | 
|  | // checkPlatformModules ensures that the non-updatable modules supplied are not part of an | 
|  | // apex module. | 
|  | func (b *platformBootclasspathModule) checkPlatformModules(ctx android.ModuleContext, modules []android.Module) { | 
|  | // TODO(satayev): change this check to only allow core-icu4j, all apex jars should not be here. | 
|  | for _, m := range modules { | 
|  | apexInfo, _ := android.OtherModuleProvider(ctx, m, android.ApexInfoProvider) | 
|  | fromUpdatableApex := apexInfo.Updatable | 
|  | if fromUpdatableApex { | 
|  | // error: this jar is part of an updatable apex | 
|  | ctx.ModuleErrorf("module %q from updatable apexes %q is not allowed in the platform bootclasspath", ctx.OtherModuleName(m), apexInfo.InApexVariants) | 
|  | } else { | 
|  | // ok: this jar is part of the platform or a non-updatable apex | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | // checkApexModules ensures that the apex modules supplied are not from the platform. | 
|  | func (b *platformBootclasspathModule) checkApexModules(ctx android.ModuleContext, modules []android.Module) { | 
|  | for _, m := range modules { | 
|  | apexInfo, _ := android.OtherModuleProvider(ctx, m, android.ApexInfoProvider) | 
|  | fromUpdatableApex := apexInfo.Updatable | 
|  | if fromUpdatableApex { | 
|  | // ok: this jar is part of an updatable apex | 
|  | } else { | 
|  | name := ctx.OtherModuleName(m) | 
|  | if apexInfo.IsForPlatform() { | 
|  | // If AlwaysUsePrebuiltSdks() returns true then it is possible that the updatable list will | 
|  | // include platform variants of a prebuilt module due to workarounds elsewhere. In that case | 
|  | // do not treat this as an error. | 
|  | // TODO(b/179354495): Always treat this as an error when migration to bootclasspath_fragment | 
|  | //  modules is complete. | 
|  | if !ctx.Config().AlwaysUsePrebuiltSdks() { | 
|  | // error: this jar is part of the platform | 
|  | ctx.ModuleErrorf("module %q from platform is not allowed in the apex boot jars list", name) | 
|  | } | 
|  | } else { | 
|  | // TODO(b/177892522): Treat this as an error. | 
|  | // Cannot do that at the moment because framework-wifi and framework-tethering are in the | 
|  | // PRODUCT_APEX_BOOT_JARS but not marked as updatable in AOSP. | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | // generateHiddenAPIBuildActions generates all the hidden API related build rules. | 
|  | func (b *platformBootclasspathModule) generateHiddenAPIBuildActions(ctx android.ModuleContext, modules []android.Module, fragments []android.Module) bootDexJarByModule { | 
|  | createEmptyHiddenApiFiles := func() { | 
|  | paths := android.OutputPaths{b.hiddenAPIFlagsCSV, b.hiddenAPIIndexCSV, b.hiddenAPIMetadataCSV} | 
|  | for _, path := range paths { | 
|  | ctx.Build(pctx, android.BuildParams{ | 
|  | Rule:   android.Touch, | 
|  | Output: path, | 
|  | }) | 
|  | } | 
|  | } | 
|  |  | 
|  | // Save the paths to the monolithic files for retrieval via OutputFiles(). | 
|  | b.hiddenAPIFlagsCSV = hiddenAPISingletonPaths(ctx).flags | 
|  | b.hiddenAPIIndexCSV = hiddenAPISingletonPaths(ctx).index | 
|  | b.hiddenAPIMetadataCSV = hiddenAPISingletonPaths(ctx).metadata | 
|  |  | 
|  | bootDexJarByModule := extractBootDexJarsFromModules(ctx, modules) | 
|  |  | 
|  | // Don't run any hiddenapi rules if hidden api checks are disabled. This is a performance | 
|  | // optimization that can be used to reduce the incremental build time but as its name suggests it | 
|  | // can be unsafe to use, e.g. when the changes affect anything that goes on the bootclasspath. | 
|  | if ctx.Config().DisableHiddenApiChecks() { | 
|  | createEmptyHiddenApiFiles() | 
|  | return bootDexJarByModule | 
|  | } | 
|  |  | 
|  | // Construct a list of ClasspathElement objects from the modules and fragments. | 
|  | classpathElements := CreateClasspathElements(ctx, modules, fragments) | 
|  |  | 
|  | monolithicInfo := b.createAndProvideMonolithicHiddenAPIInfo(ctx, classpathElements) | 
|  |  | 
|  | // Extract the classes jars only from those libraries that do not have corresponding fragments as | 
|  | // the fragments will have already provided the flags that are needed. | 
|  | classesJars := monolithicInfo.ClassesJars | 
|  |  | 
|  | if len(classesJars) == 0 { | 
|  | // This product does not include any monolithic jars. Monolithic hiddenapi flag generation is not required. | 
|  | // However, generate an empty file so that the dist tags in f/b/boot/Android.bp can be resolved, and `m dist` works. | 
|  | createEmptyHiddenApiFiles() | 
|  | return bootDexJarByModule | 
|  | } | 
|  |  | 
|  | // Create the input to pass to buildRuleToGenerateHiddenAPIStubFlagsFile | 
|  | input := newHiddenAPIFlagInput() | 
|  |  | 
|  | // Gather stub library information from the dependencies on modules provided by | 
|  | // hiddenAPIComputeMonolithicStubLibModules. | 
|  | input.gatherStubLibInfo(ctx, nil) | 
|  |  | 
|  | // Use the flag files from this module and all the fragments. | 
|  | input.FlagFilesByCategory = monolithicInfo.FlagsFilesByCategory | 
|  |  | 
|  | // Generate the monolithic stub-flags.csv file. | 
|  | stubFlags := hiddenAPISingletonPaths(ctx).stubFlags | 
|  | buildRuleToGenerateHiddenAPIStubFlagsFile(ctx, "platform-bootclasspath-monolithic-hiddenapi-stub-flags", "monolithic hidden API stub flags", stubFlags, bootDexJarByModule.bootDexJars(), input, monolithicInfo.StubFlagSubsets) | 
|  |  | 
|  | // Generate the annotation-flags.csv file from all the module annotations. | 
|  | annotationFlags := android.PathForModuleOut(ctx, "hiddenapi-monolithic", "annotation-flags-from-classes.csv") | 
|  | buildRuleToGenerateAnnotationFlags(ctx, "intermediate hidden API flags", classesJars, stubFlags, annotationFlags) | 
|  |  | 
|  | // Generate the monolithic hiddenapi-flags.csv file. | 
|  | // | 
|  | // Use annotation flags generated directly from the classes jars as well as annotation flag files | 
|  | // provided by prebuilts. | 
|  | allAnnotationFlagFiles := android.Paths{annotationFlags} | 
|  | allAnnotationFlagFiles = append(allAnnotationFlagFiles, monolithicInfo.AnnotationFlagsPaths...) | 
|  | allFlags := hiddenAPISingletonPaths(ctx).flags | 
|  | buildRuleToGenerateHiddenApiFlags(ctx, "hiddenAPIFlagsFile", "monolithic hidden API flags", allFlags, stubFlags, allAnnotationFlagFiles, monolithicInfo.FlagsFilesByCategory, monolithicInfo.FlagSubsets, android.OptionalPath{}) | 
|  |  | 
|  | // Generate an intermediate monolithic hiddenapi-metadata.csv file directly from the annotations | 
|  | // in the source code. | 
|  | intermediateMetadataCSV := android.PathForModuleOut(ctx, "hiddenapi-monolithic", "metadata-from-classes.csv") | 
|  | buildRuleToGenerateMetadata(ctx, "intermediate hidden API metadata", classesJars, stubFlags, intermediateMetadataCSV) | 
|  |  | 
|  | // Generate the monolithic hiddenapi-metadata.csv file. | 
|  | // | 
|  | // Use metadata files generated directly from the classes jars as well as metadata files provided | 
|  | // by prebuilts. | 
|  | // | 
|  | // This has the side effect of ensuring that the output file uses | quotes just in case that is | 
|  | // important for the tools that consume the metadata file. | 
|  | allMetadataFlagFiles := android.Paths{intermediateMetadataCSV} | 
|  | allMetadataFlagFiles = append(allMetadataFlagFiles, monolithicInfo.MetadataPaths...) | 
|  | metadataCSV := hiddenAPISingletonPaths(ctx).metadata | 
|  | b.buildRuleMergeCSV(ctx, "monolithic hidden API metadata", allMetadataFlagFiles, metadataCSV) | 
|  |  | 
|  | // Generate an intermediate monolithic hiddenapi-index.csv file directly from the CSV files in the | 
|  | // classes jars. | 
|  | intermediateIndexCSV := android.PathForModuleOut(ctx, "hiddenapi-monolithic", "index-from-classes.csv") | 
|  | buildRuleToGenerateIndex(ctx, "intermediate hidden API index", classesJars, intermediateIndexCSV) | 
|  |  | 
|  | // Generate the monolithic hiddenapi-index.csv file. | 
|  | // | 
|  | // Use index files generated directly from the classes jars as well as index files provided | 
|  | // by prebuilts. | 
|  | allIndexFlagFiles := android.Paths{intermediateIndexCSV} | 
|  | allIndexFlagFiles = append(allIndexFlagFiles, monolithicInfo.IndexPaths...) | 
|  | indexCSV := hiddenAPISingletonPaths(ctx).index | 
|  | b.buildRuleMergeCSV(ctx, "monolithic hidden API index", allIndexFlagFiles, indexCSV) | 
|  |  | 
|  | return bootDexJarByModule | 
|  | } | 
|  |  | 
|  | // createAndProvideMonolithicHiddenAPIInfo creates a MonolithicHiddenAPIInfo and provides it for | 
|  | // testing. | 
|  | func (b *platformBootclasspathModule) createAndProvideMonolithicHiddenAPIInfo(ctx android.ModuleContext, classpathElements ClasspathElements) MonolithicHiddenAPIInfo { | 
|  | // Create a temporary input structure in which to collate information provided directly by this | 
|  | // module, either through properties or direct dependencies. | 
|  | temporaryInput := newHiddenAPIFlagInput() | 
|  |  | 
|  | // Create paths to the flag files specified in the properties. | 
|  | temporaryInput.extractFlagFilesFromProperties(ctx, &b.properties.HiddenAPIFlagFileProperties) | 
|  |  | 
|  | // Create the monolithic info, by starting with the flag files specified on this and then merging | 
|  | // in information from all the fragment dependencies of this. | 
|  | monolithicInfo := newMonolithicHiddenAPIInfo(ctx, temporaryInput.FlagFilesByCategory, classpathElements) | 
|  |  | 
|  | // Store the information for testing. | 
|  | android.SetProvider(ctx, MonolithicHiddenAPIInfoProvider, monolithicInfo) | 
|  | return monolithicInfo | 
|  | } | 
|  |  | 
|  | func (b *platformBootclasspathModule) buildRuleMergeCSV(ctx android.ModuleContext, desc string, inputPaths android.Paths, outputPath android.WritablePath) { | 
|  | rule := android.NewRuleBuilder(pctx, ctx) | 
|  | rule.Command(). | 
|  | BuiltTool("merge_csv"). | 
|  | Flag("--key_field signature"). | 
|  | FlagWithOutput("--output=", outputPath). | 
|  | Inputs(inputPaths) | 
|  |  | 
|  | rule.Build(desc, desc) | 
|  | } |