Separate monolithic hidden API processing from hiddenAPIFlagFileInfo

The hiddenAPIFlagFileInfo was being used for both the input and output
of bootclasspath_fragment and platform_bootclasspath and also to pass
information around to various hidden API rule methods. Supporting
multiple different uses in this way made it hard to reason about.

This change creates a separate structure for use by the
platform_bootclasspath. Follow up changes will split out other
functionality into separate types.

Bug: 179354495
Test: m com.android.art com.android.ipsec com.android.os.statsd com.android.conscrypt
      - verify that this does not change the contents of the apex files
Change-Id: Ia5c5f65ae5645486c42819c669a8601588217f88

java/hiddenapi_monolithic.go

@@ -0,0 +1,91 @@
+// Copyright (C) 2021 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 java
+
+import (
+	"android/soong/android"
+	"github.com/google/blueprint"
+)
+
+// MonolithicHiddenAPIInfo contains information needed/provided by the hidden API generation of the
+// monolithic hidden API files.
+//
+// Each list of paths includes all the equivalent paths from each of the bootclasspath_fragment
+// modules that contribute to the platform-bootclasspath.
+type MonolithicHiddenAPIInfo struct {
+	// FlagsFilesByCategory maps from the flag file category to the paths containing information for
+	// that category.
+	FlagsFilesByCategory FlagFilesByCategory
+
+	// The paths to the generated stub-flags.csv files.
+	StubFlagsPaths android.Paths
+
+	// The paths to the generated annotation-flags.csv files.
+	AnnotationFlagsPaths android.Paths
+
+	// The paths to the generated metadata.csv files.
+	MetadataPaths android.Paths
+
+	// The paths to the generated index.csv files.
+	IndexPaths android.Paths
+
+	// The paths to the generated all-flags.csv files.
+	AllFlagsPaths android.Paths
+}
+
+// newMonolithicHiddenAPIInfo creates a new MonolithicHiddenAPIInfo from the flagFilesByCategory
+// plus information provided by each of the fragments.
+func newMonolithicHiddenAPIInfo(ctx android.ModuleContext, flagFilesByCategory FlagFilesByCategory, fragments []android.Module) MonolithicHiddenAPIInfo {
+	monolithicInfo := MonolithicHiddenAPIInfo{}
+
+	monolithicInfo.FlagsFilesByCategory = flagFilesByCategory
+
+	// Merge all the information from the fragments. The fragments form a DAG so it is possible that
+	// this will introduce duplicates so they will be resolved after processing all the fragments.
+	for _, fragment := range fragments {
+		if ctx.OtherModuleHasProvider(fragment, hiddenAPIFlagFileInfoProvider) {
+			info := ctx.OtherModuleProvider(fragment, hiddenAPIFlagFileInfoProvider).(hiddenAPIFlagFileInfo)
+			monolithicInfo.append(&info)
+		}
+	}
+
+	// Dedup paths.
+	monolithicInfo.dedup()
+
+	return monolithicInfo
+}
+
+// append appends all the files from the supplied info to the corresponding files in this struct.
+func (i *MonolithicHiddenAPIInfo) append(other *hiddenAPIFlagFileInfo) {
+	i.FlagsFilesByCategory.append(other.FlagFilesByCategory)
+	i.StubFlagsPaths = append(i.StubFlagsPaths, other.StubFlagsPaths...)
+	i.AnnotationFlagsPaths = append(i.AnnotationFlagsPaths, other.AnnotationFlagsPaths...)
+	i.MetadataPaths = append(i.MetadataPaths, other.MetadataPaths...)
+	i.IndexPaths = append(i.IndexPaths, other.IndexPaths...)
+	i.AllFlagsPaths = append(i.AllFlagsPaths, other.AllFlagsPaths...)
+}
+
+// dedup removes duplicates in all the paths, while maintaining the order in which they were
+// appended.
+func (i *MonolithicHiddenAPIInfo) dedup() {
+	i.FlagsFilesByCategory.dedup()
+	i.StubFlagsPaths = android.FirstUniquePaths(i.StubFlagsPaths)
+	i.AnnotationFlagsPaths = android.FirstUniquePaths(i.AnnotationFlagsPaths)
+	i.MetadataPaths = android.FirstUniquePaths(i.MetadataPaths)
+	i.IndexPaths = android.FirstUniquePaths(i.IndexPaths)
+	i.AllFlagsPaths = android.FirstUniquePaths(i.AllFlagsPaths)
+}
+
+var monolithicHiddenAPIInfoProvider = blueprint.NewProvider(MonolithicHiddenAPIInfo{})