Add aconfig dump of all aconfig_declarations modules.

Bug: 283910439
Test: m dist ; m all_aconfig_declarations ; gqui from all_aconfig_declarations.pb proto /source/aosp-master-with-phones/build/make/tools/aconfig/protos/aconfig.proto:android.aconfig.parsed_flags
Change-Id: Ia89c7f9c53fa1600fa2f9c8ea01319e949e09f58

aconfig/Android.bp

@@ -19,6 +19,7 @@ bootstrap_go_package {
         "aconfig_declarations.go",
         "aconfig_values.go",
         "aconfig_value_set.go",
+        "all_aconfig_declarations.go",
         "init.go",
         "java_aconfig_library.go",
         "testing.go",

aconfig/all_aconfig_declarations.go

@@ -0,0 +1,63 @@
+// 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 aconfig
+
+import (
+	"android/soong/android"
+)
+
+// A singleton module that collects all of the aconfig flags declared in the
+// tree into a single combined file for export to the external flag setting
+// server (inside Google it's Gantry).
+//
+// Note that this is ALL aconfig_declarations modules present in the tree, not just
+// ones that are relevant to the product currently being built, so that that infra
+// doesn't need to pull from multiple builds and merge them.
+func AllAconfigDeclarationsFactory() android.Singleton {
+	return &allAconfigDeclarationsSingleton{}
+}
+
+type allAconfigDeclarationsSingleton struct {
+	intermediatePath android.OutputPath
+}
+
+func (this *allAconfigDeclarationsSingleton) GenerateBuildActions(ctx android.SingletonContext) {
+	// Find all of the aconfig_declarations modules
+	var cacheFiles android.Paths
+	ctx.VisitAllModules(func(module android.Module) {
+		if !ctx.ModuleHasProvider(module, declarationsProviderKey) {
+			return
+		}
+		decl := ctx.ModuleProvider(module, declarationsProviderKey).(declarationsProviderData)
+		cacheFiles = append(cacheFiles, decl.IntermediatePath)
+	})
+
+	// Generate build action for aconfig
+	this.intermediatePath = android.PathForIntermediates(ctx, "all_aconfig_declarations.pb")
+	ctx.Build(pctx, android.BuildParams{
+		Rule:        allDeclarationsRule,
+		Inputs:      cacheFiles,
+		Output:      this.intermediatePath,
+		Description: "all_aconfig_declarations",
+		Args: map[string]string{
+			"cache_files": android.JoinPathsWithPrefix(cacheFiles, "--cache "),
+		},
+	})
+	ctx.Phony("all_aconfig_declarations", this.intermediatePath)
+}
+
+func (this *allAconfigDeclarationsSingleton) MakeVars(ctx android.MakeVarsContext) {
+	ctx.DistForGoal("droid", this.intermediatePath)
+}

aconfig/init.go

@@ -54,6 +54,15 @@ var (
 			},
 			Restat: true,
 		})
+
+	// For all_aconfig_declarations
+	allDeclarationsRule = pctx.AndroidStaticRule("all_aconfig_declarations_dump",
+		blueprint.RuleParams{
+			Command: `${aconfig} dump --format protobuf --out ${out} ${cache_files}`,
+			CommandDeps: []string{
+				"${aconfig}",
+			},
+		}, "cache_files")
 )
 
 func init() {
@@ -67,4 +76,5 @@ func registerBuildComponents(ctx android.RegistrationContext) {
 	ctx.RegisterModuleType("aconfig_values", ValuesFactory)
 	ctx.RegisterModuleType("aconfig_value_set", ValueSetFactory)
 	ctx.RegisterModuleType("java_aconfig_library", JavaDeclarationsLibraryFactory)
+	ctx.RegisterParallelSingletonType("all_aconfig_declarations", AllAconfigDeclarationsFactory)
 }

android/util.go

@@ -42,6 +42,16 @@ func Concat[T any](s1, s2 []T) []T {
 	return res
 }
 
+// JoinPathsWithPrefix converts the paths to strings, prefixes them
+// with prefix and then joins them separated by " ".
+func JoinPathsWithPrefix(paths []Path, prefix string) string {
+	strs := make([]string, len(paths))
+	for i := range paths {
+		strs[i] = paths[i].String()
+	}
+	return JoinWithPrefixAndSeparator(strs, prefix, " ")
+}
+
 // JoinWithPrefix prepends the prefix to each string in the list and
 // returns them joined together with " " as separator.
 func JoinWithPrefix(strs []string, prefix string) string {