Merge logtags from cc modules too

Merged logtags files will be used for Soong built filesystem images.

Bug: 336189540
Test: m out/soong/.intermediates/all-event-log-tags.txt
Test: m out/target/common/obj/all-event-log-tags.txt
Change-Id: Ib590c2bc8073e9acee6b45ef08092768237cf9d3
diff --git a/android/Android.bp b/android/Android.bp
index f130d3a..f0be44b 100644
--- a/android/Android.bp
+++ b/android/Android.bp
@@ -60,6 +60,7 @@
         "license_metadata.go",
         "license_sdk_member.go",
         "licenses.go",
+        "logtags.go",
         "makevars.go",
         "metrics.go",
         "module.go",
diff --git a/android/logtags.go b/android/logtags.go
new file mode 100644
index 0000000..d11cccf
--- /dev/null
+++ b/android/logtags.go
@@ -0,0 +1,56 @@
+// Copyright 2024 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 android
+
+import "github.com/google/blueprint"
+
+func init() {
+	RegisterParallelSingletonType("logtags", LogtagsSingleton)
+}
+
+type LogtagsInfo struct {
+	Logtags Paths
+}
+
+var LogtagsProviderKey = blueprint.NewProvider[*LogtagsInfo]()
+
+func LogtagsSingleton() Singleton {
+	return &logtagsSingleton{}
+}
+
+type logtagsSingleton struct{}
+
+func MergedLogtagsPath(ctx PathContext) OutputPath {
+	return PathForIntermediates(ctx, "all-event-log-tags.txt")
+}
+
+func (l *logtagsSingleton) GenerateBuildActions(ctx SingletonContext) {
+	var allLogtags Paths
+	ctx.VisitAllModules(func(module Module) {
+		if !module.ExportedToMake() {
+			return
+		}
+		if logtagsInfo, ok := SingletonModuleProvider(ctx, module, LogtagsProviderKey); ok {
+			allLogtags = append(allLogtags, logtagsInfo.Logtags...)
+		}
+	})
+
+	builder := NewRuleBuilder(pctx, ctx)
+	builder.Command().
+		BuiltTool("merge-event-log-tags").
+		FlagWithOutput("-o ", MergedLogtagsPath(ctx)).
+		Inputs(SortedUniquePaths(allLogtags))
+	builder.Build("all-event-log-tags.txt", "merge logtags")
+}