Convert oemaids_headers / passwd / group to Soong

Bug: 118089258
Test: m oemaids_header_gen oemaids_headers passwd group
Change-Id: Ie3b92a499b44391e0692da5d9ad067089a62aabb

tools/fs_config/fs_config.go

@@ -0,0 +1,60 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// 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 fs_config
+
+import (
+	"android/soong/android"
+)
+
+var pctx = android.NewPackageContext("android/soong/fs_config")
+
+func init() {
+	android.RegisterModuleType("target_fs_config_gen_filegroup", targetFSConfigGenFactory)
+}
+
+// target_fs_config_gen_filegroup is used to expose the file pointed to by TARGET_FS_CONFIG_GEN to
+// genrules in Soong. If TARGET_FS_CONFIG_GEN is empty, it will export an empty file instead.
+func targetFSConfigGenFactory() android.Module {
+	module := &targetFSConfigGen{}
+	android.InitAndroidModule(module)
+	return module
+}
+
+var _ android.SourceFileProducer = (*targetFSConfigGen)(nil)
+
+type targetFSConfigGen struct {
+	android.ModuleBase
+	path android.Path
+}
+
+func (targetFSConfigGen) DepsMutator(ctx android.BottomUpMutatorContext) {}
+
+func (t *targetFSConfigGen) GenerateAndroidBuildActions(ctx android.ModuleContext) {
+	if ret := ctx.DeviceConfig().TargetFSConfigGen(); ret != nil && *ret != "" {
+		t.path = android.PathForSource(ctx, *ret)
+	} else {
+		path := android.PathForModuleGen(ctx, "empty")
+		t.path = path
+
+		rule := android.NewRuleBuilder()
+		rule.Command().Text("rm -rf").Output(path)
+		rule.Command().Text("touch").Output(path)
+		rule.Build(pctx, ctx, "fs_config_empty", "create empty file")
+	}
+}
+
+func (t *targetFSConfigGen) Srcs() android.Paths {
+	return android.Paths{t.path}
+}