Soong filesystem may install aconfig_flags.pb

By setting aconfig_flags: true, soong filesystem module installs the
aconfig_flags.pb file to its etc directory.

We need to define aconfigFilePaths to ModuleBase to store the list of
aconfig file paths that is generated from the GenerateBuildActions().
The aconfigFilePaths are collected when build the filesystem module
to build the aconfig_flags.pb for the filesystem image.

Bug: 335363964
Test: compare the cache list with those generated from make.
Change-Id: Ia32b566bf43174e94b9e610b9503608c6b583899

android/aconfig_providers.go

@@ -130,6 +130,7 @@ func aconfigUpdateAndroidBuildActions(ctx ModuleContext) {
 			AconfigFiles: mergedAconfigFiles,
 			ModeInfos:    mergedModeInfos,
 		})
+		ctx.Module().base().aconfigFilePaths = getAconfigFilePaths(ctx.Module().base(), mergedAconfigFiles)
 	}
 }
 

android/module.go

@@ -902,6 +902,9 @@ type ModuleBase struct {
 	installedInitRcPaths         InstallPaths
 	installedVintfFragmentsPaths InstallPaths
 
+	// Merged Aconfig files for all transitive deps.
+	aconfigFilePaths Paths
+
 	// set of dependency module:location mappings used to populate the license metadata for
 	// apex containers.
 	licenseInstallMap []string

android/module_context.go

@@ -482,6 +482,10 @@ func (m *moduleContext) PackageFile(installPath InstallPath, name string, srcPat
 	return m.packageFile(fullInstallPath, srcPath, false)
 }
 
+func (m *moduleContext) getAconfigPaths() *Paths {
+	return &m.module.base().aconfigFilePaths
+}
+
 func (m *moduleContext) packageFile(fullInstallPath InstallPath, srcPath Path, executable bool) PackagingSpec {
 	licenseFiles := m.Module().EffectiveLicenseFiles()
 	spec := PackagingSpec{
@@ -492,6 +496,7 @@ func (m *moduleContext) packageFile(fullInstallPath InstallPath, srcPath Path, e
 		effectiveLicenseFiles: &licenseFiles,
 		partition:             fullInstallPath.partition,
 		skipInstall:           m.skipInstall(),
+		aconfigPaths:          m.getAconfigPaths(),
 	}
 	m.packagingSpecs = append(m.packagingSpecs, spec)
 	return spec
@@ -616,6 +621,7 @@ func (m *moduleContext) InstallSymlink(installPath InstallPath, name string, src
 		executable:       false,
 		partition:        fullInstallPath.partition,
 		skipInstall:      m.skipInstall(),
+		aconfigPaths:     m.getAconfigPaths(),
 	})
 
 	return fullInstallPath
@@ -658,6 +664,7 @@ func (m *moduleContext) InstallAbsoluteSymlink(installPath InstallPath, name str
 		executable:       false,
 		partition:        fullInstallPath.partition,
 		skipInstall:      m.skipInstall(),
+		aconfigPaths:     m.getAconfigPaths(),
 	})
 
 	return fullInstallPath

android/packaging.go

@@ -48,6 +48,9 @@ type PackagingSpec struct {
 	// is created via InstallFile or InstallSymlink) or a simple packaging (i.e. created via
 	// PackageFile).
 	skipInstall bool
+
+	// Paths of aconfig files for the built artifact
+	aconfigPaths *Paths
 }
 
 func (p *PackagingSpec) Equals(other *PackagingSpec) bool {
@@ -102,6 +105,11 @@ func (p *PackagingSpec) SkipInstall() bool {
 	return p.skipInstall
 }
 
+// Paths of aconfig files for the built artifact
+func (p *PackagingSpec) GetAconfigPaths() Paths {
+	return *p.aconfigPaths
+}
+
 type PackageModule interface {
 	Module
 	packagingBase() *PackagingBase

filesystem/Android.bp

@@ -15,6 +15,7 @@ bootstrap_go_package {
         "soong-phony", // for testing
     ],
     srcs: [
+        "aconfig_files.go",
         "avb_add_hash_footer.go",
         "avb_gen_vbmeta_image.go",
         "bootimg.go",

filesystem/aconfig_files.go

@@ -0,0 +1,58 @@
+// Copyright (C) 2024 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 filesystem
+
+import (
+	"android/soong/android"
+	"path/filepath"
+	"strings"
+
+	"github.com/google/blueprint/proptools"
+)
+
+func (f *filesystem) buildAconfigFlagsFiles(ctx android.ModuleContext, builder *android.RuleBuilder, specs map[string]android.PackagingSpec, dir android.Path) {
+	if !proptools.Bool(f.properties.Gen_aconfig_flags_pb) {
+		return
+	}
+
+	aconfigFlagsBuilderPath := android.PathForModuleOut(ctx, "aconfig_flags_builder.sh")
+	aconfigToolPath := ctx.Config().HostToolPath(ctx, "aconfig")
+	cmd := builder.Command().Tool(aconfigFlagsBuilderPath).Implicit(aconfigToolPath)
+
+	installAconfigFlags := filepath.Join(dir.String(), "etc", "aconfig_flags_"+f.partitionName()+".pb")
+
+	var sb strings.Builder
+	sb.WriteString("set -e\n")
+	sb.WriteString(aconfigToolPath.String())
+	sb.WriteString(" dump-cache --dedup --format protobuf --out ")
+	sb.WriteString(installAconfigFlags)
+	sb.WriteString(" \\\n")
+
+	var caches []string
+	for _, ps := range specs {
+		cmd.Implicits(ps.GetAconfigPaths())
+		caches = append(caches, ps.GetAconfigPaths().Strings()...)
+	}
+	caches = android.SortedUniqueStrings(caches)
+
+	for _, cache := range caches {
+		sb.WriteString("  --cache ")
+		sb.WriteString(cache)
+		sb.WriteString(" \\\n")
+	}
+	sb.WriteRune('\n')
+
+	android.WriteExecutableFileRuleVerbatim(ctx, aconfigFlagsBuilderPath, sb.String())
+}

filesystem/filesystem.go

@@ -131,6 +131,9 @@ type filesystemProperties struct {
 	// Default is false
 	Build_logtags *bool
 
+	// Install aconfig_flags.pb file for the modules installed in this partition.
+	Gen_aconfig_flags_pb *bool
+
 	Fsverity fsverityProperties
 }
 
@@ -300,6 +303,7 @@ func (f *filesystem) buildImageUsingBuildImage(ctx android.ModuleContext) androi
 	f.addMakeBuiltFiles(ctx, builder, rootDir)
 	f.buildFsverityMetadataFiles(ctx, builder, specs, rootDir, rebasedDir)
 	f.buildEventLogtagsFile(ctx, builder, rebasedDir)
+	f.buildAconfigFlagsFiles(ctx, builder, specs, rebasedDir)
 
 	// run host_init_verifier
 	// Ideally we should have a concept of pluggable linters that verify the generated image.
@@ -441,6 +445,7 @@ func (f *filesystem) buildCpioImage(ctx android.ModuleContext, compressed bool)
 	f.buildNonDepsFiles(ctx, builder, rootDir)
 	f.buildFsverityMetadataFiles(ctx, builder, specs, rootDir, rebasedDir)
 	f.buildEventLogtagsFile(ctx, builder, rebasedDir)
+	f.buildAconfigFlagsFiles(ctx, builder, specs, rebasedDir)
 
 	output := android.PathForModuleOut(ctx, f.installFileName()).OutputPath
 	cmd := builder.Command().