Implement aidl_library module type
We currently specifies aidl files directly to the srcs prop on a filegroup or other module types such as cc_library or java_library. We use aidl.include_dirs prop to specify paths to aidl headers. This include_dirs pattern isn't migratable to Bazel because Bazel requires explicit dependencies.
This CL introduces aidl_library to better map with Bazel's aidl_library rule and to enable aidl headers to be specified in a separate aidl_library or the hdrs prop. A follow-up CL will turn on inputs sandbox to enforce all aidl headers be explicitly specified in Android.bp
Test: go test
Bug: 278704136
Change-Id: I2c99af080525bf8a6c5724ed5ee2001842969098
diff --git a/aidl_library/aidl_library.go b/aidl_library/aidl_library.go
new file mode 100644
index 0000000..2a42170
--- /dev/null
+++ b/aidl_library/aidl_library.go
@@ -0,0 +1,120 @@
+// Copyright 2023 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 aidl_library
+
+import (
+ "android/soong/android"
+
+ "github.com/google/blueprint"
+ "github.com/google/blueprint/proptools"
+)
+
+func init() {
+ registerAidlLibraryBuildComponents(android.InitRegistrationContext)
+}
+
+func registerAidlLibraryBuildComponents(ctx android.RegistrationContext) {
+ ctx.RegisterModuleType("aidl_library", AidlLibraryFactory)
+}
+
+type aidlLibraryProperties struct {
+ // srcs lists files that are included in this module for aidl compilation
+ Srcs []string `android:"path"`
+
+ // hdrs lists the headers that are imported by srcs but are not compiled by aidl to language binding code
+ // hdrs is provided to support Bazel migration. It is a no-op until
+ // we enable input sandbox in aidl compilation action
+ Hdrs []string `android:"path"`
+
+ // The prefix to strip from the paths of the .aidl files
+ // The remaining path is the package path of the aidl interface
+ Strip_import_prefix *string
+
+ // List of aidl files or aidl_library depended on by the module
+ Deps []string `android:"arch_variant"`
+}
+
+type AidlLibrary struct {
+ android.ModuleBase
+ properties aidlLibraryProperties
+}
+
+type AidlLibraryInfo struct {
+ // The direct aidl files of the module
+ Srcs android.Paths
+ // The include dirs to the direct aidl files and those provided from aidl_library deps
+ IncludeDirs android.DepSet
+}
+
+// AidlLibraryProvider provides the srcs and the transitive include dirs
+var AidlLibraryProvider = blueprint.NewProvider(AidlLibraryInfo{})
+
+func (lib *AidlLibrary) GenerateAndroidBuildActions(ctx android.ModuleContext) {
+ includeDirsDepSetBuilder := android.NewDepSetBuilder(android.PREORDER)
+
+ if len(lib.properties.Srcs) == 0 && len(lib.properties.Hdrs) == 0 {
+ ctx.ModuleErrorf("at least srcs or hdrs prop must be non-empty")
+ }
+
+ srcs := android.PathsForModuleSrc(ctx, lib.properties.Srcs)
+ if lib.properties.Strip_import_prefix != nil {
+ srcs = android.PathsWithModuleSrcSubDir(
+ ctx,
+ srcs,
+ android.String(lib.properties.Strip_import_prefix))
+ }
+
+ includeDir := android.PathForModuleSrc(
+ ctx,
+ proptools.StringDefault(lib.properties.Strip_import_prefix, ""),
+ )
+
+ includeDirsDepSetBuilder.Direct(includeDir)
+
+ for _, dep := range ctx.GetDirectDepsWithTag(aidlLibraryTag) {
+ if ctx.OtherModuleHasProvider(dep, AidlLibraryProvider) {
+ info := ctx.OtherModuleProvider(dep, AidlLibraryProvider).(AidlLibraryInfo)
+ includeDirsDepSetBuilder.Transitive(&info.IncludeDirs)
+ }
+ }
+
+ // TODO(b/279960133) Propagate direct and transitive headers/srcs when aidl action sandboxes inputs
+ ctx.SetProvider(AidlLibraryProvider, AidlLibraryInfo{
+ Srcs: srcs,
+ IncludeDirs: *includeDirsDepSetBuilder.Build(),
+ })
+}
+
+// aidl_library contains a list of .aidl files and the strip_import_prefix to
+// to strip from the paths of the .aidl files. The sub-path left-over after stripping
+// corresponds to the aidl package path the aidl interfaces are scoped in
+func AidlLibraryFactory() android.Module {
+ module := &AidlLibrary{}
+ module.AddProperties(&module.properties)
+ android.InitAndroidModule(module)
+ return module
+}
+
+type aidlDependencyTag struct {
+ blueprint.BaseDependencyTag
+}
+
+var aidlLibraryTag = aidlDependencyTag{}
+
+func (lib *AidlLibrary) DepsMutator(ctx android.BottomUpMutatorContext) {
+ for _, dep := range lib.properties.Deps {
+ ctx.AddDependency(lib, aidlLibraryTag, dep)
+ }
+}