Support generating module_info.json in Soong

Generate module_info.json for some Soong modules in Soong in order to
pass fewer properties to Kati, which can prevent Kati reanalysis when
some Android.bp changes are made.

Soong modules can export a ModuleInfoJSONProvider containing the
data that should be included in module-info.json.  During the androidmk
singleton the providers are collected and written to a single JSON
file.  Make then merges the Soong modules into its own modules.

For now, to keep the result as similar as possible to the
module-info.json currently being generated by Make, only modules that
are exported to Make are written to the Soong module-info.json.

Bug: 309006256
Test: Compare module-info.json
Change-Id: I996520eb48e04743d43ac11c9aba0f3ada7745de

android/Android.bp

@@ -62,6 +62,7 @@ bootstrap_go_package {
         "metrics.go",
         "module.go",
         "module_context.go",
+        "module_info_json.go",
         "mutator.go",
         "namespace.go",
         "neverallow.go",

android/androidmk.go

@@ -30,6 +30,7 @@ import (
 	"reflect"
 	"runtime"
 	"sort"
+	"strconv"
 	"strings"
 
 	"github.com/google/blueprint"
@@ -626,6 +627,10 @@ func (a *AndroidMkEntries) fillInEntries(ctx fillInEntriesContext, mod blueprint
 		a.SetPath("LOCAL_SOONG_LICENSE_METADATA", licenseMetadata.LicenseMetadataPath)
 	}
 
+	if _, ok := SingletonModuleProvider(ctx, mod, ModuleInfoJSONProvider); ok {
+		a.SetBool("LOCAL_SOONG_MODULE_INFO_JSON", true)
+	}
+
 	extraCtx := &androidMkExtraEntriesContext{
 		ctx: ctx,
 		mod: mod,
@@ -643,14 +648,14 @@ func (a *AndroidMkEntries) fillInEntries(ctx fillInEntriesContext, mod blueprint
 	}
 }
 
+func (a *AndroidMkEntries) disabled() bool {
+	return a.Disabled || !a.OutputFile.Valid()
+}
+
 // write  flushes the AndroidMkEntries's in-struct data populated by AndroidMkEntries into the
 // given Writer object.
 func (a *AndroidMkEntries) write(w io.Writer) {
-	if a.Disabled {
+	if a.disabled() {
-		return
-	}
-
-	if !a.OutputFile.Valid() {
 		return
 	}
 
@@ -696,7 +701,9 @@ func (c *androidMkSingleton) GenerateBuildActions(ctx SingletonContext) {
 		return
 	}
 
-	err := translateAndroidMk(ctx, absolutePath(transMk.String()), androidMkModulesList)
+	moduleInfoJSON := PathForOutput(ctx, "module-info"+String(ctx.Config().productVariables.Make_suffix)+".json")
+
+	err := translateAndroidMk(ctx, absolutePath(transMk.String()), moduleInfoJSON, androidMkModulesList)
 	if err != nil {
 		ctx.Errorf(err.Error())
 	}
@@ -707,14 +714,16 @@ func (c *androidMkSingleton) GenerateBuildActions(ctx SingletonContext) {
 	})
 }
 
-func translateAndroidMk(ctx SingletonContext, absMkFile string, mods []blueprint.Module) error {
+func translateAndroidMk(ctx SingletonContext, absMkFile string, moduleInfoJSONPath WritablePath, mods []blueprint.Module) error {
 	buf := &bytes.Buffer{}
 
+	var moduleInfoJSONs []*ModuleInfoJSON
+
 	fmt.Fprintln(buf, "LOCAL_MODULE_MAKEFILE := $(lastword $(MAKEFILE_LIST))")
 
 	typeStats := make(map[string]int)
 	for _, mod := range mods {
-		err := translateAndroidMkModule(ctx, buf, mod)
+		err := translateAndroidMkModule(ctx, buf, &moduleInfoJSONs, mod)
 		if err != nil {
 			os.Remove(absMkFile)
 			return err
@@ -736,10 +745,36 @@ func translateAndroidMk(ctx SingletonContext, absMkFile string, mods []blueprint
 		fmt.Fprintf(buf, "STATS.SOONG_MODULE_TYPE.%s := %d\n", mod_type, typeStats[mod_type])
 	}
 
-	return pathtools.WriteFileIfChanged(absMkFile, buf.Bytes(), 0666)
+	err := pathtools.WriteFileIfChanged(absMkFile, buf.Bytes(), 0666)
+	if err != nil {
+		return err
+	}
+
+	return writeModuleInfoJSON(ctx, moduleInfoJSONs, moduleInfoJSONPath)
 }
 
-func translateAndroidMkModule(ctx SingletonContext, w io.Writer, mod blueprint.Module) error {
+func writeModuleInfoJSON(ctx SingletonContext, moduleInfoJSONs []*ModuleInfoJSON, moduleInfoJSONPath WritablePath) error {
+	moduleInfoJSONBuf := &strings.Builder{}
+	moduleInfoJSONBuf.WriteString("[")
+	for i, moduleInfoJSON := range moduleInfoJSONs {
+		if i != 0 {
+			moduleInfoJSONBuf.WriteString(",\n")
+		}
+		moduleInfoJSONBuf.WriteString("{")
+		moduleInfoJSONBuf.WriteString(strconv.Quote(moduleInfoJSON.core.RegisterName))
+		moduleInfoJSONBuf.WriteString(":")
+		err := encodeModuleInfoJSON(moduleInfoJSONBuf, moduleInfoJSON)
+		moduleInfoJSONBuf.WriteString("}")
+		if err != nil {
+			return err
+		}
+	}
+	moduleInfoJSONBuf.WriteString("]")
+	WriteFileRule(ctx, moduleInfoJSONPath, moduleInfoJSONBuf.String())
+	return nil
+}
+
+func translateAndroidMkModule(ctx SingletonContext, w io.Writer, moduleInfoJSONs *[]*ModuleInfoJSON, mod blueprint.Module) error {
 	defer func() {
 		if r := recover(); r != nil {
 			panic(fmt.Errorf("%s in translateAndroidMkModule for module %s variant %s",
@@ -748,17 +783,23 @@ func translateAndroidMkModule(ctx SingletonContext, w io.Writer, mod blueprint.M
 	}()
 
 	// Additional cases here require review for correct license propagation to make.
+	var err error
 	switch x := mod.(type) {
 	case AndroidMkDataProvider:
-		return translateAndroidModule(ctx, w, mod, x)
+		err = translateAndroidModule(ctx, w, moduleInfoJSONs, mod, x)
 	case bootstrap.GoBinaryTool:
-		return translateGoBinaryModule(ctx, w, mod, x)
+		err = translateGoBinaryModule(ctx, w, mod, x)
 	case AndroidMkEntriesProvider:
-		return translateAndroidMkEntriesModule(ctx, w, mod, x)
+		err = translateAndroidMkEntriesModule(ctx, w, moduleInfoJSONs, mod, x)
 	default:
 		// Not exported to make so no make variables to set.
-		return nil
 	}
+
+	if err != nil {
+		return err
+	}
+
+	return err
 }
 
 // A simple, special Android.mk entry output func to make it possible to build blueprint tools using
@@ -801,8 +842,8 @@ func (data *AndroidMkData) fillInData(ctx fillInEntriesContext, mod blueprint.Mo
 
 // A support func for the deprecated AndroidMkDataProvider interface. Use AndroidMkEntryProvider
 // instead.
-func translateAndroidModule(ctx SingletonContext, w io.Writer, mod blueprint.Module,
+func translateAndroidModule(ctx SingletonContext, w io.Writer, moduleInfoJSONs *[]*ModuleInfoJSON,
-	provider AndroidMkDataProvider) error {
+	mod blueprint.Module, provider AndroidMkDataProvider) error {
 
 	amod := mod.(Module).base()
 	if shouldSkipAndroidMkProcessing(amod) {
@@ -864,17 +905,19 @@ func translateAndroidModule(ctx SingletonContext, w io.Writer, mod blueprint.Mod
 		WriteAndroidMkData(w, data)
 	}
 
+	if !data.Entries.disabled() {
+		if moduleInfoJSON, ok := SingletonModuleProvider(ctx, mod, ModuleInfoJSONProvider); ok {
+			*moduleInfoJSONs = append(*moduleInfoJSONs, moduleInfoJSON)
+		}
+	}
+
 	return nil
 }
 
 // A support func for the deprecated AndroidMkDataProvider interface. Use AndroidMkEntryProvider
 // instead.
 func WriteAndroidMkData(w io.Writer, data AndroidMkData) {
-	if data.Disabled {
+	if data.Entries.disabled() {
-		return
-	}
-
-	if !data.OutputFile.Valid() {
 		return
 	}
 
@@ -889,18 +932,26 @@ func WriteAndroidMkData(w io.Writer, data AndroidMkData) {
 	fmt.Fprintln(w, "include "+data.Include)
 }
 
-func translateAndroidMkEntriesModule(ctx SingletonContext, w io.Writer, mod blueprint.Module,
+func translateAndroidMkEntriesModule(ctx SingletonContext, w io.Writer, moduleInfoJSONs *[]*ModuleInfoJSON,
-	provider AndroidMkEntriesProvider) error {
+	mod blueprint.Module, provider AndroidMkEntriesProvider) error {
 	if shouldSkipAndroidMkProcessing(mod.(Module).base()) {
 		return nil
 	}
 
+	entriesList := provider.AndroidMkEntries()
+
 	// Any new or special cases here need review to verify correct propagation of license information.
-	for _, entries := range provider.AndroidMkEntries() {
+	for _, entries := range entriesList {
 		entries.fillInEntries(ctx, mod)
 		entries.write(w)
 	}
 
+	if len(entriesList) > 0 && !entriesList[0].disabled() {
+		if moduleInfoJSON, ok := SingletonModuleProvider(ctx, mod, ModuleInfoJSONProvider); ok {
+			*moduleInfoJSONs = append(*moduleInfoJSONs, moduleInfoJSON)
+		}
+	}
+
 	return nil
 }
 

android/module.go

@@ -23,6 +23,7 @@ import (
 	"net/url"
 	"path/filepath"
 	"reflect"
+	"slices"
 	"sort"
 	"strings"
 
@@ -876,6 +877,10 @@ type ModuleBase struct {
 
 	// The path to the generated license metadata file for the module.
 	licenseMetadataFile WritablePath
+
+	// moduleInfoJSON can be filled out by GenerateAndroidBuildActions to write a JSON file that will
+	// be included in the final module-info.json produced by Make.
+	moduleInfoJSON *ModuleInfoJSON
 }
 
 func (m *ModuleBase) AddJSONData(d *map[string]interface{}) {
@@ -1771,11 +1776,90 @@ func (m *ModuleBase) GenerateBuildActions(blueprintCtx blueprint.ModuleContext)
 
 	buildLicenseMetadata(ctx, m.licenseMetadataFile)
 
+	if m.moduleInfoJSON != nil {
+		var installed InstallPaths
+		installed = append(installed, m.katiInstalls.InstallPaths()...)
+		installed = append(installed, m.katiSymlinks.InstallPaths()...)
+		installed = append(installed, m.katiInitRcInstalls.InstallPaths()...)
+		installed = append(installed, m.katiVintfInstalls.InstallPaths()...)
+		installedStrings := installed.Strings()
+
+		var targetRequired, hostRequired []string
+		if ctx.Host() {
+			targetRequired = m.commonProperties.Target_required
+		} else {
+			hostRequired = m.commonProperties.Host_required
+		}
+
+		var data []string
+		for _, d := range m.testData {
+			data = append(data, d.ToRelativeInstallPath())
+		}
+
+		if m.moduleInfoJSON.Uninstallable {
+			installedStrings = nil
+			if len(m.moduleInfoJSON.CompatibilitySuites) == 1 && m.moduleInfoJSON.CompatibilitySuites[0] == "null-suite" {
+				m.moduleInfoJSON.CompatibilitySuites = nil
+				m.moduleInfoJSON.TestConfig = nil
+				m.moduleInfoJSON.AutoTestConfig = nil
+				data = nil
+			}
+		}
+
+		m.moduleInfoJSON.core = CoreModuleInfoJSON{
+			RegisterName:       m.moduleInfoRegisterName(ctx, m.moduleInfoJSON.SubName),
+			Path:               []string{ctx.ModuleDir()},
+			Installed:          installedStrings,
+			ModuleName:         m.BaseModuleName() + m.moduleInfoJSON.SubName,
+			SupportedVariants:  []string{m.moduleInfoVariant(ctx)},
+			TargetDependencies: targetRequired,
+			HostDependencies:   hostRequired,
+			Data:               data,
+		}
+		SetProvider(ctx, ModuleInfoJSONProvider, m.moduleInfoJSON)
+	}
+
 	m.buildParams = ctx.buildParams
 	m.ruleParams = ctx.ruleParams
 	m.variables = ctx.variables
 }
 
+func (m *ModuleBase) moduleInfoRegisterName(ctx ModuleContext, subName string) string {
+	name := m.BaseModuleName()
+
+	prefix := ""
+	if ctx.Host() {
+		if ctx.Os() != ctx.Config().BuildOS {
+			prefix = "host_cross_"
+		}
+	}
+	suffix := ""
+	arches := slices.Clone(ctx.Config().Targets[ctx.Os()])
+	arches = slices.DeleteFunc(arches, func(target Target) bool {
+		return target.NativeBridge != ctx.Target().NativeBridge
+	})
+	if len(arches) > 0 && ctx.Arch().ArchType != arches[0].Arch.ArchType {
+		if ctx.Arch().ArchType.Multilib == "lib32" {
+			suffix = "_32"
+		} else {
+			suffix = "_64"
+		}
+	}
+	return prefix + name + subName + suffix
+}
+
+func (m *ModuleBase) moduleInfoVariant(ctx ModuleContext) string {
+	variant := "DEVICE"
+	if ctx.Host() {
+		if ctx.Os() != ctx.Config().BuildOS {
+			variant = "HOST_CROSS"
+		} else {
+			variant = "HOST"
+		}
+	}
+	return variant
+}
+
 // Check the supplied dist structure to make sure that it is valid.
 //
 // property - the base property, e.g. dist or dists[1], which is combined with the

android/module_context.go

@@ -210,6 +210,11 @@ type ModuleContext interface {
 	// LicenseMetadataFile returns the path where the license metadata for this module will be
 	// generated.
 	LicenseMetadataFile() Path
+
+	// ModuleInfoJSON returns a pointer to the ModuleInfoJSON struct that can be filled out by
+	// GenerateAndroidBuildActions.  If it is called then the struct will be written out and included in
+	// the module-info.json generated by Make, and Make will not generate its own data for this module.
+	ModuleInfoJSON() *ModuleInfoJSON
 }
 
 type moduleContext struct {
@@ -518,6 +523,8 @@ func (m *moduleContext) installFile(installPath InstallPath, name string, srcPat
 
 	if !m.skipInstall() {
 		deps = append(deps, InstallPaths(m.module.base().installFilesDepSet.ToList())...)
+		deps = append(deps, m.module.base().installedInitRcPaths...)
+		deps = append(deps, m.module.base().installedVintfFragmentsPaths...)
 
 		var implicitDeps, orderOnlyDeps Paths
 
@@ -695,6 +702,15 @@ func (m *moduleContext) LicenseMetadataFile() Path {
 	return m.module.base().licenseMetadataFile
 }
 
+func (m *moduleContext) ModuleInfoJSON() *ModuleInfoJSON {
+	if moduleInfoJSON := m.module.base().moduleInfoJSON; moduleInfoJSON != nil {
+		return moduleInfoJSON
+	}
+	moduleInfoJSON := &ModuleInfoJSON{}
+	m.module.base().moduleInfoJSON = moduleInfoJSON
+	return moduleInfoJSON
+}
+
 // Returns a list of paths expanded from globs and modules referenced using ":module" syntax.  The property must
 // be tagged with `android:"path" to support automatic source module dependency resolution.
 //

android/module_info_json.go

@@ -0,0 +1,103 @@
+package android
+
+import (
+	"encoding/json"
+	"io"
+	"slices"
+
+	"github.com/google/blueprint"
+)
+
+type CoreModuleInfoJSON struct {
+	RegisterName       string   `json:"-"`
+	Path               []string `json:"path,omitempty"`                // $(sort $(ALL_MODULES.$(m).PATH))
+	Installed          []string `json:"installed,omitempty"`           // $(sort $(ALL_MODULES.$(m).INSTALLED))
+	ModuleName         string   `json:"module_name,omitempty"`         // $(ALL_MODULES.$(m).MODULE_NAME)
+	SupportedVariants  []string `json:"supported_variants,omitempty"`  // $(sort $(ALL_MODULES.$(m).SUPPORTED_VARIANTS))
+	HostDependencies   []string `json:"host_dependencies,omitempty"`   // $(sort $(ALL_MODULES.$(m).HOST_REQUIRED_FROM_TARGET))
+	TargetDependencies []string `json:"target_dependencies,omitempty"` // $(sort $(ALL_MODULES.$(m).TARGET_REQUIRED_FROM_HOST))
+	Data               []string `json:"data,omitempty"`                // $(sort $(ALL_MODULES.$(m).TEST_DATA))
+}
+
+type ModuleInfoJSON struct {
+	core                CoreModuleInfoJSON
+	SubName             string   `json:"-"`
+	Uninstallable       bool     `json:"-"`
+	Class               []string `json:"class,omitempty"`                 // $(sort $(ALL_MODULES.$(m).CLASS))
+	Tags                []string `json:"tags,omitempty"`                  // $(sort $(ALL_MODULES.$(m).TAGS))
+	Dependencies        []string `json:"dependencies,omitempty"`          // $(sort $(ALL_DEPS.$(m).ALL_DEPS))
+	SharedLibs          []string `json:"shared_libs,omitempty"`           // $(sort $(ALL_MODULES.$(m).SHARED_LIBS))
+	StaticLibs          []string `json:"static_libs,omitempty"`           // $(sort $(ALL_MODULES.$(m).STATIC_LIBS))
+	SystemSharedLibs    []string `json:"system_shared_libs,omitempty"`    // $(sort $(ALL_MODULES.$(m).SYSTEM_SHARED_LIBS))
+	Srcs                []string `json:"srcs,omitempty"`                  // $(sort $(ALL_MODULES.$(m).SRCS))
+	SrcJars             []string `json:"srcjars,omitempty"`               // $(sort $(ALL_MODULES.$(m).SRCJARS))
+	ClassesJar          []string `json:"classes_jar,omitempty"`           // $(sort $(ALL_MODULES.$(m).CLASSES_JAR))
+	TestMainlineModules []string `json:"test_mainline_modules,omitempty"` // $(sort $(ALL_MODULES.$(m).TEST_MAINLINE_MODULES))
+	IsUnitTest          bool     `json:"is_unit_test,omitempty"`          // $(ALL_MODULES.$(m).IS_UNIT_TEST)
+	TestOptionsTags     []string `json:"test_options_tags,omitempty"`     // $(sort $(ALL_MODULES.$(m).TEST_OPTIONS_TAGS))
+	RuntimeDependencies []string `json:"runtime_dependencies,omitempty"`  // $(sort $(ALL_MODULES.$(m).LOCAL_RUNTIME_LIBRARIES))
+	StaticDependencies  []string `json:"static_dependencies,omitempty"`   // $(sort $(ALL_MODULES.$(m).LOCAL_STATIC_LIBRARIES))
+	DataDependencies    []string `json:"data_dependencies,omitempty"`     // $(sort $(ALL_MODULES.$(m).TEST_DATA_BINS))
+
+	CompatibilitySuites []string `json:"compatibility_suites,omitempty"` // $(sort $(ALL_MODULES.$(m).COMPATIBILITY_SUITES))
+	AutoTestConfig      []string `json:"auto_test_config,omitempty"`     // $(ALL_MODULES.$(m).auto_test_config)
+	TestConfig          []string `json:"test_config,omitempty"`          // $(strip $(ALL_MODULES.$(m).TEST_CONFIG) $(ALL_MODULES.$(m).EXTRA_TEST_CONFIGS)
+}
+
+//ALL_DEPS.$(LOCAL_MODULE).ALL_DEPS := $(sort \
+//$(ALL_DEPS.$(LOCAL_MODULE).ALL_DEPS) \
+//$(LOCAL_STATIC_LIBRARIES) \
+//$(LOCAL_WHOLE_STATIC_LIBRARIES) \
+//$(LOCAL_SHARED_LIBRARIES) \
+//$(LOCAL_DYLIB_LIBRARIES) \
+//$(LOCAL_RLIB_LIBRARIES) \
+//$(LOCAL_PROC_MACRO_LIBRARIES) \
+//$(LOCAL_HEADER_LIBRARIES) \
+//$(LOCAL_STATIC_JAVA_LIBRARIES) \
+//$(LOCAL_JAVA_LIBRARIES) \
+//$(LOCAL_JNI_SHARED_LIBRARIES))
+
+type combinedModuleInfoJSON struct {
+	*CoreModuleInfoJSON
+	*ModuleInfoJSON
+}
+
+func encodeModuleInfoJSON(w io.Writer, moduleInfoJSON *ModuleInfoJSON) error {
+	moduleInfoJSONCopy := *moduleInfoJSON
+
+	sortAndUnique := func(s *[]string) {
+		*s = slices.Clone(*s)
+		slices.Sort(*s)
+		*s = slices.Compact(*s)
+	}
+
+	sortAndUnique(&moduleInfoJSONCopy.core.Path)
+	sortAndUnique(&moduleInfoJSONCopy.core.Installed)
+	sortAndUnique(&moduleInfoJSONCopy.core.SupportedVariants)
+	sortAndUnique(&moduleInfoJSONCopy.core.HostDependencies)
+	sortAndUnique(&moduleInfoJSONCopy.core.TargetDependencies)
+	sortAndUnique(&moduleInfoJSONCopy.core.Data)
+
+	sortAndUnique(&moduleInfoJSONCopy.Class)
+	sortAndUnique(&moduleInfoJSONCopy.Tags)
+	sortAndUnique(&moduleInfoJSONCopy.Dependencies)
+	sortAndUnique(&moduleInfoJSONCopy.SharedLibs)
+	sortAndUnique(&moduleInfoJSONCopy.StaticLibs)
+	sortAndUnique(&moduleInfoJSONCopy.SystemSharedLibs)
+	sortAndUnique(&moduleInfoJSONCopy.Srcs)
+	sortAndUnique(&moduleInfoJSONCopy.SrcJars)
+	sortAndUnique(&moduleInfoJSONCopy.ClassesJar)
+	sortAndUnique(&moduleInfoJSONCopy.TestMainlineModules)
+	sortAndUnique(&moduleInfoJSONCopy.TestOptionsTags)
+	sortAndUnique(&moduleInfoJSONCopy.RuntimeDependencies)
+	sortAndUnique(&moduleInfoJSONCopy.StaticDependencies)
+	sortAndUnique(&moduleInfoJSONCopy.DataDependencies)
+	sortAndUnique(&moduleInfoJSONCopy.CompatibilitySuites)
+	sortAndUnique(&moduleInfoJSONCopy.AutoTestConfig)
+	sortAndUnique(&moduleInfoJSONCopy.TestConfig)
+
+	encoder := json.NewEncoder(w)
+	return encoder.Encode(combinedModuleInfoJSON{&moduleInfoJSONCopy.core, &moduleInfoJSONCopy})
+}
+
+var ModuleInfoJSONProvider = blueprint.NewProvider[*ModuleInfoJSON]()

cmd/merge_module_info_json/Android.bp

@@ -0,0 +1,30 @@
+// Copyright 2021 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 {
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+blueprint_go_binary {
+    name: "merge_module_info_json",
+    srcs: [
+        "merge_module_info_json.go",
+    ],
+    deps: [
+        "soong-response",
+    ],
+    testSrcs: [
+        "merge_module_info_json_test.go",
+    ],
+}

cmd/merge_module_info_json/merge_module_info_json.go

@@ -0,0 +1,223 @@
+// Copyright 2021 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.
+
+// merge_module_info_json is a utility that merges module_info.json files generated by
+// Soong and Make.
+
+package main
+
+import (
+	"android/soong/response"
+	"cmp"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"os"
+	"slices"
+)
+
+var (
+	out      = flag.String("o", "", "output file")
+	listFile = flag.String("l", "", "input file list file")
+)
+
+func usage() {
+	fmt.Fprintf(os.Stderr, "usage: %s -o <output file> <input files>\n", os.Args[0])
+	flag.PrintDefaults()
+	fmt.Fprintln(os.Stderr, "merge_module_info_json reads input files that each contain an array of json objects")
+	fmt.Fprintln(os.Stderr, "and writes them out as a single json array to the output file.")
+
+	os.Exit(2)
+}
+
+func main() {
+	flag.Usage = usage
+	flag.Parse()
+
+	if *out == "" {
+		fmt.Fprintf(os.Stderr, "%s: error: -o is required\n", os.Args[0])
+		usage()
+	}
+
+	inputs := flag.Args()
+	if *listFile != "" {
+		listFileInputs, err := readListFile(*listFile)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "failed to read list file %s: %s", *listFile, err)
+			os.Exit(1)
+		}
+		inputs = append(inputs, listFileInputs...)
+	}
+
+	err := mergeJsonObjects(*out, inputs)
+
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "%s: error: %s\n", os.Args[0], err.Error())
+		os.Exit(1)
+	}
+}
+
+func readListFile(file string) ([]string, error) {
+	f, err := os.Open(*listFile)
+	if err != nil {
+		return nil, err
+	}
+	return response.ReadRspFile(f)
+}
+
+func mergeJsonObjects(output string, inputs []string) error {
+	combined := make(map[string]any)
+	for _, input := range inputs {
+		objects, err := decodeObjectFromJson(input)
+		if err != nil {
+			return err
+		}
+
+		for _, object := range objects {
+			for k, v := range object {
+				if old, exists := combined[k]; exists {
+					v = combine(old, v)
+				}
+				combined[k] = v
+			}
+		}
+	}
+
+	f, err := os.Create(output)
+	if err != nil {
+		return fmt.Errorf("failed to open output file: %w", err)
+	}
+	encoder := json.NewEncoder(f)
+	encoder.SetIndent("", "  ")
+	err = encoder.Encode(combined)
+	if err != nil {
+		return fmt.Errorf("failed to encode to output file: %w", err)
+	}
+
+	return nil
+}
+
+func decodeObjectFromJson(input string) ([]map[string]any, error) {
+	f, err := os.Open(input)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open input file: %w", err)
+	}
+
+	decoder := json.NewDecoder(f)
+	var object any
+	err = decoder.Decode(&object)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse input file %q: %w", input, err)
+	}
+
+	switch o := object.(type) {
+	case []any:
+		var ret []map[string]any
+		for _, arrayElement := range o {
+			if m, ok := arrayElement.(map[string]any); ok {
+				ret = append(ret, m)
+			} else {
+				return nil, fmt.Errorf("unknown JSON type in array %T", arrayElement)
+			}
+		}
+		return ret, nil
+
+	case map[string]any:
+		return []map[string]any{o}, nil
+	}
+
+	return nil, fmt.Errorf("unknown JSON type %T", object)
+}
+
+func combine(old, new any) any {
+	//	fmt.Printf("%#v %#v\n", old, new)
+	switch oldTyped := old.(type) {
+	case map[string]any:
+		if newObject, ok := new.(map[string]any); ok {
+			return combineObjects(oldTyped, newObject)
+		} else {
+			panic(fmt.Errorf("expected map[string]any, got %#v", new))
+		}
+	case []any:
+		if newArray, ok := new.([]any); ok {
+			return combineArrays(oldTyped, newArray)
+		} else {
+			panic(fmt.Errorf("expected []any, got %#v", new))
+		}
+	case string:
+		if newString, ok := new.(string); ok {
+			if oldTyped != newString {
+				panic(fmt.Errorf("strings %q and %q don't match", oldTyped, newString))
+			}
+			return oldTyped
+		} else {
+			panic(fmt.Errorf("expected []any, got %#v", new))
+		}
+	default:
+		panic(fmt.Errorf("can't combine type %T", old))
+	}
+}
+
+func combineObjects(old, new map[string]any) map[string]any {
+	for k, newField := range new {
+		// HACK: Don't merge "test_config" field.  This matches the behavior in base_rules.mk that overwrites
+		// instead of appending ALL_MODULES.$(my_register_name).TEST_CONFIG, keeping the
+		if k == "test_config" {
+			old[k] = newField
+			continue
+		}
+		if oldField, exists := old[k]; exists {
+			oldField = combine(oldField, newField)
+			old[k] = oldField
+		} else {
+			old[k] = newField
+		}
+	}
+
+	return old
+}
+
+func combineArrays(old, new []any) []any {
+	containsNonStrings := false
+	for _, oldElement := range old {
+		switch oldElement.(type) {
+		case string:
+		default:
+			containsNonStrings = true
+		}
+	}
+	for _, newElement := range new {
+		found := false
+		for _, oldElement := range old {
+			if oldElement == newElement {
+				found = true
+				break
+			}
+		}
+		if !found {
+			switch newElement.(type) {
+			case string:
+			default:
+				containsNonStrings = true
+			}
+			old = append(old, newElement)
+		}
+	}
+	if !containsNonStrings {
+		slices.SortFunc(old, func(a, b any) int {
+			return cmp.Compare(a.(string), b.(string))
+		})
+	}
+	return old
+}

cmd/merge_module_info_json/merge_module_info_json_test.go

@@ -0,0 +1,58 @@
+// Copyright 2021 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 main
+
+import (
+	"reflect"
+	"testing"
+)
+
+func Test_combine(t *testing.T) {
+	tests := []struct {
+		name string
+		old  any
+		new  any
+		want any
+	}{
+		{
+			name: "objects",
+			old: map[string]any{
+				"foo": "bar",
+				"baz": []any{"a"},
+			},
+			new: map[string]any{
+				"foo": "bar",
+				"baz": []any{"b"},
+			},
+			want: map[string]any{
+				"foo": "bar",
+				"baz": []any{"a", "b"},
+			},
+		},
+		{
+			name: "arrays",
+			old:  []any{"foo", "bar"},
+			new:  []any{"foo", "baz"},
+			want: []any{"bar", "baz", "foo"},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := combine(tt.old, tt.new); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("combine() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}