cc/fuzz.go - SHIFTPHONES/android_build_soong - Gitiles

 // Copyright 2016 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 cc

 import (
 	"encoding/json"
 	"path/filepath"
 	"sort"
 	"strings"

 	"android/soong/android"
 	"android/soong/cc/config"
 )

 type FuzzConfig struct {
 	// Email address of people to CC on bugs or contact about this fuzz target.
 	Cc []string `json:"cc,omitempty"`
 	// Boolean specifying whether to disable the fuzz target from running
 	// automatically in continuous fuzzing infrastructure.
 	Disable *bool `json:"disable,omitempty"`
 	// Component in Google's bug tracking system that bugs should be filed to.
 	Componentid *int64 `json:"componentid,omitempty"`
 	// Hotlists in Google's bug tracking system that bugs should be marked with.
 	Hotlists []string `json:"hotlists,omitempty"`
 }

 func (f *FuzzConfig) String() string {
 	b, err := json.Marshal(f)
 	if err != nil {
 		panic(err)
 	}

 	return string(b)
 }

 type FuzzProperties struct {
 	// Optional list of seed files to be installed to the fuzz target's output
 	// directory.
 	Corpus []string `android:"path"`
 	// Optional dictionary to be installed to the fuzz target's output directory.
 	Dictionary *string `android:"path"`
 	// Config for running the target on fuzzing infrastructure.
 	Fuzz_config *FuzzConfig
 }

 func init() {
 	android.RegisterModuleType("cc_fuzz", FuzzFactory)
 	android.RegisterSingletonType("cc_fuzz_packaging", fuzzPackagingFactory)
 }

 // cc_fuzz creates a host/device fuzzer binary. Host binaries can be found at
 // $ANDROID_HOST_OUT/fuzz/, and device binaries can be found at /data/fuzz on
 // your device, or $ANDROID_PRODUCT_OUT/data/fuzz in your build tree.
 func FuzzFactory() android.Module {
 	module := NewFuzz(android.HostAndDeviceSupported)
 	return module.Init()
 }

 func NewFuzzInstaller() *baseInstaller {
 	return NewBaseInstaller("fuzz", "fuzz", InstallInData)
 }

 type fuzzBinary struct {
 	*binaryDecorator
 	*baseCompiler

 	Properties            FuzzProperties
 	dictionary            android.Path
 	corpus                android.Paths
 	corpusIntermediateDir android.Path
 	config                android.Path
 	installedSharedDeps   []string
 }

 func (fuzz *fuzzBinary) linkerProps() []interface{} {
 	props := fuzz.binaryDecorator.linkerProps()
 	props = append(props, &fuzz.Properties)
 	return props
 }

 func (fuzz *fuzzBinary) linkerInit(ctx BaseModuleContext) {
 	fuzz.binaryDecorator.linkerInit(ctx)
 }

 func (fuzz *fuzzBinary) linkerDeps(ctx DepsContext, deps Deps) Deps {
 	deps.StaticLibs = append(deps.StaticLibs,
 		config.LibFuzzerRuntimeLibrary(ctx.toolchain()))
 	deps = fuzz.binaryDecorator.linkerDeps(ctx, deps)
 	return deps
 }

 func (fuzz *fuzzBinary) linkerFlags(ctx ModuleContext, flags Flags) Flags {
 	flags = fuzz.binaryDecorator.linkerFlags(ctx, flags)
 	// RunPaths on devices isn't instantiated by the base linker. `../lib` for
 	// installed fuzz targets (both host and device), and `./lib` for fuzz
 	// target packages.
 	flags.Local.LdFlags = append(flags.Local.LdFlags, `-Wl,-rpath,\$$ORIGIN/../lib`)
 	flags.Local.LdFlags = append(flags.Local.LdFlags, `-Wl,-rpath,\$$ORIGIN/lib`)
 	return flags
 }

 // This function performs a breadth-first search over the provided module's
 // dependencies using `visitDirectDeps` to enumerate all shared library
 // dependencies. We require breadth-first expansion, as otherwise we may
 // incorrectly use the core libraries (sanitizer runtimes, libc, libdl, etc.)
 // from a dependency. This may cause issues when dependencies have explicit
 // sanitizer tags, as we may get a dependency on an unsanitized libc, etc.
 func collectAllSharedDependencies(
 	module android.Module,
 	sharedDeps map[string]android.Path,
 	ctx android.SingletonContext) {
 	var fringe []android.Module

 	// Enumerate the first level of dependencies, as we discard all non-library
 	// modules in the BFS loop below.
 	ctx.VisitDirectDeps(module, func(dep android.Module) {
 		if isValidSharedDependency(dep, sharedDeps) {
 			fringe = append(fringe, dep)
 		}
 	})

 	for i := 0; i < len(fringe); i++ {
 		module := fringe[i]
 		if _, exists := sharedDeps[module.Name()]; exists {
 			continue
 		}

 		ccModule := module.(*Module)
 		sharedDeps[ccModule.Name()] = ccModule.UnstrippedOutputFile()
 		ctx.VisitDirectDeps(module, func(dep android.Module) {
 			if isValidSharedDependency(dep, sharedDeps) {
 				fringe = append(fringe, dep)
 			}
 		})
 	}
 }

 // This function takes a module and determines if it is a unique shared library
 // that should be installed in the fuzz target output directories. This function
 // returns true, unless:
 //  - The module already exists in `sharedDeps`, or
 //  - The module is not a shared library, or
 //  - The module is a header, stub, or vendor-linked library.
 func isValidSharedDependency(
 	dependency android.Module,
 	sharedDeps map[string]android.Path) bool {
 	// TODO(b/144090547): We should be parsing these modules using
 	// ModuleDependencyTag instead of the current brute-force checking.

 	if linkable, ok := dependency.(LinkableInterface); !ok || // Discard non-linkables.
 		!linkable.CcLibraryInterface() || !linkable.Shared() || // Discard static libs.
 		linkable.UseVndk() || // Discard vendor linked libraries.
 		// Discard stubs libs (only CCLibrary variants). Prebuilt libraries should not
 		// be excluded on the basis of they're not CCLibrary()'s.
 		(linkable.CcLibrary() && linkable.BuildStubs()) {
 		return false
 	}

 	// We discarded module stubs libraries above, but the LLNDK prebuilts stubs
 	// libraries must be handled differently - by looking for the stubDecorator.
 	// Discard LLNDK prebuilts stubs as well.
 	if ccLibrary, isCcLibrary := dependency.(*Module); isCcLibrary {
 		if _, isLLndkStubLibrary := ccLibrary.linker.(*stubDecorator); isLLndkStubLibrary {
 			return false
 		}
 	}

 	// If this library has already been traversed, we don't need to do any more work.
 	if _, exists := sharedDeps[dependency.Name()]; exists {
 		return false
 	}
 	return true
 }

 func sharedLibraryInstallLocation(
 	libraryPath android.Path, isHost bool, archString string) string {
 	installLocation := "$(PRODUCT_OUT)/data"
 	if isHost {
 		installLocation = "$(HOST_OUT)"
 	}
 	installLocation = filepath.Join(
 		installLocation, "fuzz", archString, "lib", libraryPath.Base())
 	return installLocation
 }

 func (fuzz *fuzzBinary) install(ctx ModuleContext, file android.Path) {
 	fuzz.binaryDecorator.baseInstaller.dir = filepath.Join(
 		"fuzz", ctx.Target().Arch.ArchType.String(), ctx.ModuleName())
 	fuzz.binaryDecorator.baseInstaller.dir64 = filepath.Join(
 		"fuzz", ctx.Target().Arch.ArchType.String(), ctx.ModuleName())
 	fuzz.binaryDecorator.baseInstaller.install(ctx, file)

 	fuzz.corpus = android.PathsForModuleSrc(ctx, fuzz.Properties.Corpus)
 	builder := android.NewRuleBuilder()
 	intermediateDir := android.PathForModuleOut(ctx, "corpus")
 	for _, entry := range fuzz.corpus {
 		builder.Command().Text("cp").
 			Input(entry).
 			Output(intermediateDir.Join(ctx, entry.Base()))
 	}
 	builder.Build(pctx, ctx, "copy_corpus", "copy corpus")
 	fuzz.corpusIntermediateDir = intermediateDir

 	if fuzz.Properties.Dictionary != nil {
 		fuzz.dictionary = android.PathForModuleSrc(ctx, *fuzz.Properties.Dictionary)
 		if fuzz.dictionary.Ext() != ".dict" {
 			ctx.PropertyErrorf("dictionary",
 				"Fuzzer dictionary %q does not have '.dict' extension",
 				fuzz.dictionary.String())
 		}
 	}

 	if fuzz.Properties.Fuzz_config != nil {
 		configPath := android.PathForModuleOut(ctx, "config").Join(ctx, "config.json")
 		ctx.Build(pctx, android.BuildParams{
 			Rule:        android.WriteFile,
 			Description: "fuzzer infrastructure configuration",
 			Output:      configPath,
 			Args: map[string]string{
 				"content": fuzz.Properties.Fuzz_config.String(),
 			},
 		})
 		fuzz.config = configPath
 	}

 	// Grab the list of required shared libraries.
 	sharedLibraries := make(map[string]android.Path)
 	ctx.WalkDeps(func(child, parent android.Module) bool {
 		if isValidSharedDependency(child, sharedLibraries) {
 			sharedLibraries[child.Name()] = child.(*Module).UnstrippedOutputFile()
 			return true
 		}
 		return false
 	})

 	for _, lib := range sharedLibraries {
 		fuzz.installedSharedDeps = append(fuzz.installedSharedDeps,
 			sharedLibraryInstallLocation(
 				lib, ctx.Host(), ctx.Arch().ArchType.String()))
 	}

 	sort.Strings(fuzz.installedSharedDeps)
 }

 func NewFuzz(hod android.HostOrDeviceSupported) *Module {
 	module, binary := NewBinary(hod)

 	binary.baseInstaller = NewFuzzInstaller()
 	module.sanitize.SetSanitizer(fuzzer, true)

 	fuzz := &fuzzBinary{
 		binaryDecorator: binary,
 		baseCompiler:    NewBaseCompiler(),
 	}
 	module.compiler = fuzz
 	module.linker = fuzz
 	module.installer = fuzz

 	// The fuzzer runtime is not present for darwin host modules, disable cc_fuzz modules when targeting darwin.
 	android.AddLoadHook(module, func(ctx android.LoadHookContext) {
 		disableDarwinAndLinuxBionic := struct {
 			Target struct {
 				Darwin struct {
 					Enabled *bool
 				}
 				Linux_bionic struct {
 					Enabled *bool
 				}
 			}
 		}{}
 		disableDarwinAndLinuxBionic.Target.Darwin.Enabled = BoolPtr(false)
 		disableDarwinAndLinuxBionic.Target.Linux_bionic.Enabled = BoolPtr(false)
 		ctx.AppendProperties(&disableDarwinAndLinuxBionic)
 	})

 	return module
 }

 // Responsible for generating GNU Make rules that package fuzz targets into
 // their architecture & target/host specific zip file.
 type fuzzPackager struct {
 	packages                android.Paths
 	sharedLibInstallStrings []string
 	fuzzTargets             map[string]bool
 }

 func fuzzPackagingFactory() android.Singleton {
 	return &fuzzPackager{}
 }

 type fileToZip struct {
 	SourceFilePath        android.Path
 	DestinationPathPrefix string
 }

 type archAndLibraryKey struct {
 	ArchDir android.OutputPath
 	Library android.Path
 }

 func (s *fuzzPackager) GenerateBuildActions(ctx android.SingletonContext) {
 	// Map between each architecture + host/device combination, and the files that
 	// need to be packaged (in the tuple of {source file, destination folder in
 	// archive}).
 	archDirs := make(map[android.OutputPath][]fileToZip)

 	// List of shared library dependencies for each architecture + host/device combo.
 	archSharedLibraryDeps := make(map[archAndLibraryKey]bool)

 	// List of individual fuzz targets, so that 'make fuzz' also installs the targets
 	// to the correct output directories as well.
 	s.fuzzTargets = make(map[string]bool)

 	ctx.VisitAllModules(func(module android.Module) {
 		// Discard non-fuzz targets.
 		ccModule, ok := module.(*Module)
 		if !ok {
 			return
 		}

 		fuzzModule, ok := ccModule.compiler.(*fuzzBinary)
 		if !ok {
 			return
 		}

 		// Discard vendor-NDK-linked + recovery modules, they're duplicates of
 		// fuzz targets we're going to package anyway.
 		if !ccModule.Enabled() || ccModule.Properties.PreventInstall ||
 			ccModule.UseVndk() || ccModule.InRecovery() {
 			return
 		}

 		s.fuzzTargets[module.Name()] = true

 		hostOrTargetString := "target"
 		if ccModule.Host() {
 			hostOrTargetString = "host"
 		}

 		archString := ccModule.Arch().ArchType.String()
 		archDir := android.PathForIntermediates(ctx, "fuzz", hostOrTargetString, archString)

 		// Grab the list of required shared libraries.
 		sharedLibraries := make(map[string]android.Path)
 		collectAllSharedDependencies(module, sharedLibraries, ctx)

 		var files []fileToZip
 		builder := android.NewRuleBuilder()

 		// Package the corpora into a zipfile.
 		if fuzzModule.corpus != nil {
 			corpusZip := archDir.Join(ctx, module.Name()+"_seed_corpus.zip")
 			command := builder.Command().BuiltTool(ctx, "soong_zip").
 				Flag("-j").
 				FlagWithOutput("-o ", corpusZip)
 			command.FlagWithRspFileInputList("-l ", fuzzModule.corpus)
 			files = append(files, fileToZip{corpusZip, ""})
 		}

 		// Find and mark all the transiently-dependent shared libraries for
 		// packaging.
 		for _, library := range sharedLibraries {
 			files = append(files, fileToZip{library, "lib"})

 			if _, exists := archSharedLibraryDeps[archAndLibraryKey{archDir, library}]; exists {
 				continue
 			}

 			// For each architecture-specific shared library dependency, we need to
 			// install it to the output directory. Setup the install destination here,
 			// which will be used by $(copy-many-files) in the Make backend.
 			archSharedLibraryDeps[archAndLibraryKey{archDir, library}] = true
 			installDestination := sharedLibraryInstallLocation(
 				library, ccModule.Host(), archString)
 			// Escape all the variables, as the install destination here will be called
 			// via. $(eval) in Make.
 			installDestination = strings.ReplaceAll(
 				installDestination, "$", "$$")
 			s.sharedLibInstallStrings = append(s.sharedLibInstallStrings,
 				library.String()+":"+installDestination)
 		}

 		// The executable.
 		files = append(files, fileToZip{ccModule.UnstrippedOutputFile(), ""})

 		// The dictionary.
 		if fuzzModule.dictionary != nil {
 			files = append(files, fileToZip{fuzzModule.dictionary, ""})
 		}

 		// Additional fuzz config.
 		if fuzzModule.config != nil {
 			files = append(files, fileToZip{fuzzModule.config, ""})
 		}

 		fuzzZip := archDir.Join(ctx, module.Name()+".zip")
 		command := builder.Command().BuiltTool(ctx, "soong_zip").
 			Flag("-j").
 			FlagWithOutput("-o ", fuzzZip)
 		for _, file := range files {
 			if file.DestinationPathPrefix != "" {
 				command.FlagWithArg("-P ", file.DestinationPathPrefix)
 			} else {
 				command.Flag("-P ''")
 			}
 			command.FlagWithInput("-f ", file.SourceFilePath)
 		}

 		builder.Build(pctx, ctx, "create-"+fuzzZip.String(),
 			"Package "+module.Name()+" for "+archString+"-"+hostOrTargetString)

 		archDirs[archDir] = append(archDirs[archDir], fileToZip{fuzzZip, ""})
 	})

 	for archDir, filesToZip := range archDirs {
 		arch := archDir.Base()
 		hostOrTarget := filepath.Base(filepath.Dir(archDir.String()))
 		builder := android.NewRuleBuilder()
 		outputFile := android.PathForOutput(ctx, "fuzz-"+hostOrTarget+"-"+arch+".zip")
 		s.packages = append(s.packages, outputFile)

 		command := builder.Command().BuiltTool(ctx, "soong_zip").
 			Flag("-j").
 			FlagWithOutput("-o ", outputFile).
 			Flag("-L 0") // No need to try and re-compress the zipfiles.

 		for _, fileToZip := range filesToZip {
 			if fileToZip.DestinationPathPrefix != "" {
 				command.FlagWithArg("-P ", fileToZip.DestinationPathPrefix)
 			} else {
 				command.Flag("-P ''")
 			}
 			command.FlagWithInput("-f ", fileToZip.SourceFilePath)
 		}

 		builder.Build(pctx, ctx, "create-fuzz-package-"+arch+"-"+hostOrTarget,
 			"Create fuzz target packages for "+arch+"-"+hostOrTarget)
 	}
 }

 func (s *fuzzPackager) MakeVars(ctx android.MakeVarsContext) {
 	packages := s.packages.Strings()
 	sort.Strings(packages)
 	sort.Strings(s.sharedLibInstallStrings)
 	// TODO(mitchp): Migrate this to use MakeVarsContext::DistForGoal() when it's
 	// ready to handle phony targets created in Soong. In the meantime, this
 	// exports the phony 'fuzz' target and dependencies on packages to
 	// core/main.mk so that we can use dist-for-goals.
 	ctx.Strict("SOONG_FUZZ_PACKAGING_ARCH_MODULES", strings.Join(packages, " "))
 	ctx.Strict("FUZZ_TARGET_SHARED_DEPS_INSTALL_PAIRS",
 		strings.Join(s.sharedLibInstallStrings, " "))

 	// Preallocate the slice of fuzz targets to minimise memory allocations.
 	fuzzTargets := make([]string, 0, len(s.fuzzTargets))
 	for target, _ := range s.fuzzTargets {
 		fuzzTargets = append(fuzzTargets, target)
 	}
 	sort.Strings(fuzzTargets)
 	ctx.Strict("ALL_FUZZ_TARGETS", strings.Join(fuzzTargets, " "))
 }
	// Copyright 2016 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 cc

	import (
	"encoding/json"
	"path/filepath"
	"sort"
	"strings"

	"android/soong/android"
	"android/soong/cc/config"
	)

	type FuzzConfig struct {
	// Email address of people to CC on bugs or contact about this fuzz target.
	Cc []string `json:"cc,omitempty"`
	// Boolean specifying whether to disable the fuzz target from running
	// automatically in continuous fuzzing infrastructure.
	Disable *bool `json:"disable,omitempty"`
	// Component in Google's bug tracking system that bugs should be filed to.
	Componentid *int64 `json:"componentid,omitempty"`
	// Hotlists in Google's bug tracking system that bugs should be marked with.
	Hotlists []string `json:"hotlists,omitempty"`
	}

	func (f *FuzzConfig) String() string {
	b, err := json.Marshal(f)
	if err != nil {
	panic(err)
	}

	return string(b)
	}

	type FuzzProperties struct {
	// Optional list of seed files to be installed to the fuzz target's output
	// directory.
	Corpus []string `android:"path"`
	// Optional dictionary to be installed to the fuzz target's output directory.
	Dictionary *string `android:"path"`
	// Config for running the target on fuzzing infrastructure.
	Fuzz_config *FuzzConfig
	}

	func init() {
	android.RegisterModuleType("cc_fuzz", FuzzFactory)
	android.RegisterSingletonType("cc_fuzz_packaging", fuzzPackagingFactory)
	}

	// cc_fuzz creates a host/device fuzzer binary. Host binaries can be found at
	// $ANDROID_HOST_OUT/fuzz/, and device binaries can be found at /data/fuzz on
	// your device, or $ANDROID_PRODUCT_OUT/data/fuzz in your build tree.
	func FuzzFactory() android.Module {
	module := NewFuzz(android.HostAndDeviceSupported)
	return module.Init()
	}

	func NewFuzzInstaller() *baseInstaller {
	return NewBaseInstaller("fuzz", "fuzz", InstallInData)
	}

	type fuzzBinary struct {
	*binaryDecorator
	*baseCompiler

	Properties FuzzProperties
	dictionary android.Path
	corpus android.Paths
	corpusIntermediateDir android.Path
	config android.Path
	installedSharedDeps []string
	}

	func (fuzz *fuzzBinary) linkerProps() []interface{} {
	props := fuzz.binaryDecorator.linkerProps()
	props = append(props, &fuzz.Properties)
	return props
	}

	func (fuzz *fuzzBinary) linkerInit(ctx BaseModuleContext) {
	fuzz.binaryDecorator.linkerInit(ctx)
	}

	func (fuzz *fuzzBinary) linkerDeps(ctx DepsContext, deps Deps) Deps {
	deps.StaticLibs = append(deps.StaticLibs,
	config.LibFuzzerRuntimeLibrary(ctx.toolchain()))
	deps = fuzz.binaryDecorator.linkerDeps(ctx, deps)
	return deps
	}

	func (fuzz *fuzzBinary) linkerFlags(ctx ModuleContext, flags Flags) Flags {
	flags = fuzz.binaryDecorator.linkerFlags(ctx, flags)
	// RunPaths on devices isn't instantiated by the base linker. `../lib` for
	// installed fuzz targets (both host and device), and `./lib` for fuzz
	// target packages.
	flags.Local.LdFlags = append(flags.Local.LdFlags, `-Wl,-rpath,\$$ORIGIN/../lib`)
	flags.Local.LdFlags = append(flags.Local.LdFlags, `-Wl,-rpath,\$$ORIGIN/lib`)
	return flags
	}

	// This function performs a breadth-first search over the provided module's
	// dependencies using `visitDirectDeps` to enumerate all shared library
	// dependencies. We require breadth-first expansion, as otherwise we may
	// incorrectly use the core libraries (sanitizer runtimes, libc, libdl, etc.)
	// from a dependency. This may cause issues when dependencies have explicit
	// sanitizer tags, as we may get a dependency on an unsanitized libc, etc.
	func collectAllSharedDependencies(
	module android.Module,
	sharedDeps map[string]android.Path,
	ctx android.SingletonContext) {
	var fringe []android.Module

	// Enumerate the first level of dependencies, as we discard all non-library
	// modules in the BFS loop below.
	ctx.VisitDirectDeps(module, func(dep android.Module) {
	if isValidSharedDependency(dep, sharedDeps) {
	fringe = append(fringe, dep)
	}
	})

	for i := 0; i < len(fringe); i++ {
	module := fringe[i]
	if _, exists := sharedDeps[module.Name()]; exists {
	continue
	}

	ccModule := module.(*Module)
	sharedDeps[ccModule.Name()] = ccModule.UnstrippedOutputFile()
	ctx.VisitDirectDeps(module, func(dep android.Module) {
	if isValidSharedDependency(dep, sharedDeps) {
	fringe = append(fringe, dep)
	}
	})
	}
	}

	// This function takes a module and determines if it is a unique shared library
	// that should be installed in the fuzz target output directories. This function
	// returns true, unless:
	// - The module already exists in `sharedDeps`, or
	// - The module is not a shared library, or
	// - The module is a header, stub, or vendor-linked library.
	func isValidSharedDependency(
	dependency android.Module,
	sharedDeps map[string]android.Path) bool {
	// TODO(b/144090547): We should be parsing these modules using
	// ModuleDependencyTag instead of the current brute-force checking.

	if linkable, ok := dependency.(LinkableInterface); !ok \|\| // Discard non-linkables.
	!linkable.CcLibraryInterface() \|\| !linkable.Shared() \|\| // Discard static libs.
	linkable.UseVndk() \|\| // Discard vendor linked libraries.
	// Discard stubs libs (only CCLibrary variants). Prebuilt libraries should not
	// be excluded on the basis of they're not CCLibrary()'s.
	(linkable.CcLibrary() && linkable.BuildStubs()) {
	return false
	}

	// We discarded module stubs libraries above, but the LLNDK prebuilts stubs
	// libraries must be handled differently - by looking for the stubDecorator.
	// Discard LLNDK prebuilts stubs as well.
	if ccLibrary, isCcLibrary := dependency.(*Module); isCcLibrary {
	if _, isLLndkStubLibrary := ccLibrary.linker.(*stubDecorator); isLLndkStubLibrary {
	return false
	}
	}

	// If this library has already been traversed, we don't need to do any more work.
	if _, exists := sharedDeps[dependency.Name()]; exists {
	return false
	}
	return true
	}

	func sharedLibraryInstallLocation(
	libraryPath android.Path, isHost bool, archString string) string {
	installLocation := "$(PRODUCT_OUT)/data"
	if isHost {
	installLocation = "$(HOST_OUT)"
	}
	installLocation = filepath.Join(
	installLocation, "fuzz", archString, "lib", libraryPath.Base())
	return installLocation
	}

	func (fuzz *fuzzBinary) install(ctx ModuleContext, file android.Path) {
	fuzz.binaryDecorator.baseInstaller.dir = filepath.Join(
	"fuzz", ctx.Target().Arch.ArchType.String(), ctx.ModuleName())
	fuzz.binaryDecorator.baseInstaller.dir64 = filepath.Join(
	"fuzz", ctx.Target().Arch.ArchType.String(), ctx.ModuleName())
	fuzz.binaryDecorator.baseInstaller.install(ctx, file)

	fuzz.corpus = android.PathsForModuleSrc(ctx, fuzz.Properties.Corpus)
	builder := android.NewRuleBuilder()
	intermediateDir := android.PathForModuleOut(ctx, "corpus")
	for _, entry := range fuzz.corpus {
	builder.Command().Text("cp").
	Input(entry).
	Output(intermediateDir.Join(ctx, entry.Base()))
	}
	builder.Build(pctx, ctx, "copy_corpus", "copy corpus")
	fuzz.corpusIntermediateDir = intermediateDir

	if fuzz.Properties.Dictionary != nil {
	fuzz.dictionary = android.PathForModuleSrc(ctx, *fuzz.Properties.Dictionary)
	if fuzz.dictionary.Ext() != ".dict" {
	ctx.PropertyErrorf("dictionary",
	"Fuzzer dictionary %q does not have '.dict' extension",
	fuzz.dictionary.String())
	}
	}

	if fuzz.Properties.Fuzz_config != nil {
	configPath := android.PathForModuleOut(ctx, "config").Join(ctx, "config.json")
	ctx.Build(pctx, android.BuildParams{
	Rule: android.WriteFile,
	Description: "fuzzer infrastructure configuration",
	Output: configPath,
	Args: map[string]string{
	"content": fuzz.Properties.Fuzz_config.String(),
	},
	})
	fuzz.config = configPath
	}

	// Grab the list of required shared libraries.
	sharedLibraries := make(map[string]android.Path)
	ctx.WalkDeps(func(child, parent android.Module) bool {
	if isValidSharedDependency(child, sharedLibraries) {
	sharedLibraries[child.Name()] = child.(*Module).UnstrippedOutputFile()
	return true
	}
	return false
	})

	for _, lib := range sharedLibraries {
	fuzz.installedSharedDeps = append(fuzz.installedSharedDeps,
	sharedLibraryInstallLocation(
	lib, ctx.Host(), ctx.Arch().ArchType.String()))
	}

	sort.Strings(fuzz.installedSharedDeps)
	}

	func NewFuzz(hod android.HostOrDeviceSupported) *Module {
	module, binary := NewBinary(hod)

	binary.baseInstaller = NewFuzzInstaller()
	module.sanitize.SetSanitizer(fuzzer, true)

	fuzz := &fuzzBinary{
	binaryDecorator: binary,
	baseCompiler: NewBaseCompiler(),
	}
	module.compiler = fuzz
	module.linker = fuzz
	module.installer = fuzz

	// The fuzzer runtime is not present for darwin host modules, disable cc_fuzz modules when targeting darwin.
	android.AddLoadHook(module, func(ctx android.LoadHookContext) {
	disableDarwinAndLinuxBionic := struct {
	Target struct {
	Darwin struct {
	Enabled *bool
	}
	Linux_bionic struct {
	Enabled *bool
	}
	}
	}{}
	disableDarwinAndLinuxBionic.Target.Darwin.Enabled = BoolPtr(false)
	disableDarwinAndLinuxBionic.Target.Linux_bionic.Enabled = BoolPtr(false)
	ctx.AppendProperties(&disableDarwinAndLinuxBionic)
	})

	return module
	}

	// Responsible for generating GNU Make rules that package fuzz targets into
	// their architecture & target/host specific zip file.
	type fuzzPackager struct {
	packages android.Paths
	sharedLibInstallStrings []string
	fuzzTargets map[string]bool
	}

	func fuzzPackagingFactory() android.Singleton {
	return &fuzzPackager{}
	}

	type fileToZip struct {
	SourceFilePath android.Path
	DestinationPathPrefix string
	}

	type archAndLibraryKey struct {
	ArchDir android.OutputPath
	Library android.Path
	}

	func (s *fuzzPackager) GenerateBuildActions(ctx android.SingletonContext) {
	// Map between each architecture + host/device combination, and the files that
	// need to be packaged (in the tuple of {source file, destination folder in
	// archive}).
	archDirs := make(map[android.OutputPath][]fileToZip)

	// List of shared library dependencies for each architecture + host/device combo.
	archSharedLibraryDeps := make(map[archAndLibraryKey]bool)

	// List of individual fuzz targets, so that 'make fuzz' also installs the targets
	// to the correct output directories as well.
	s.fuzzTargets = make(map[string]bool)

	ctx.VisitAllModules(func(module android.Module) {
	// Discard non-fuzz targets.
	ccModule, ok := module.(*Module)
	if !ok {
	return
	}

	fuzzModule, ok := ccModule.compiler.(*fuzzBinary)
	if !ok {
	return
	}

	// Discard vendor-NDK-linked + recovery modules, they're duplicates of
	// fuzz targets we're going to package anyway.
	if !ccModule.Enabled() \|\| ccModule.Properties.PreventInstall \|\|
	ccModule.UseVndk() \|\| ccModule.InRecovery() {
	return
	}

	s.fuzzTargets[module.Name()] = true

	hostOrTargetString := "target"
	if ccModule.Host() {
	hostOrTargetString = "host"
	}

	archString := ccModule.Arch().ArchType.String()
	archDir := android.PathForIntermediates(ctx, "fuzz", hostOrTargetString, archString)

	// Grab the list of required shared libraries.
	sharedLibraries := make(map[string]android.Path)
	collectAllSharedDependencies(module, sharedLibraries, ctx)

	var files []fileToZip
	builder := android.NewRuleBuilder()

	// Package the corpora into a zipfile.
	if fuzzModule.corpus != nil {
	corpusZip := archDir.Join(ctx, module.Name()+"_seed_corpus.zip")
	command := builder.Command().BuiltTool(ctx, "soong_zip").
	Flag("-j").
	FlagWithOutput("-o ", corpusZip)
	command.FlagWithRspFileInputList("-l ", fuzzModule.corpus)
	files = append(files, fileToZip{corpusZip, ""})
	}

	// Find and mark all the transiently-dependent shared libraries for
	// packaging.
	for _, library := range sharedLibraries {
	files = append(files, fileToZip{library, "lib"})

	if _, exists := archSharedLibraryDeps[archAndLibraryKey{archDir, library}]; exists {
	continue
	}

	// For each architecture-specific shared library dependency, we need to
	// install it to the output directory. Setup the install destination here,
	// which will be used by $(copy-many-files) in the Make backend.
	archSharedLibraryDeps[archAndLibraryKey{archDir, library}] = true
	installDestination := sharedLibraryInstallLocation(
	library, ccModule.Host(), archString)
	// Escape all the variables, as the install destination here will be called
	// via. $(eval) in Make.
	installDestination = strings.ReplaceAll(
	installDestination, "$", "$$")
	s.sharedLibInstallStrings = append(s.sharedLibInstallStrings,
	library.String()+":"+installDestination)
	}

	// The executable.
	files = append(files, fileToZip{ccModule.UnstrippedOutputFile(), ""})

	// The dictionary.
	if fuzzModule.dictionary != nil {
	files = append(files, fileToZip{fuzzModule.dictionary, ""})
	}

	// Additional fuzz config.
	if fuzzModule.config != nil {
	files = append(files, fileToZip{fuzzModule.config, ""})
	}

	fuzzZip := archDir.Join(ctx, module.Name()+".zip")
	command := builder.Command().BuiltTool(ctx, "soong_zip").
	Flag("-j").
	FlagWithOutput("-o ", fuzzZip)
	for _, file := range files {
	if file.DestinationPathPrefix != "" {
	command.FlagWithArg("-P ", file.DestinationPathPrefix)
	} else {
	command.Flag("-P ''")
	}
	command.FlagWithInput("-f ", file.SourceFilePath)
	}

	builder.Build(pctx, ctx, "create-"+fuzzZip.String(),
	"Package "+module.Name()+" for "+archString+"-"+hostOrTargetString)

	archDirs[archDir] = append(archDirs[archDir], fileToZip{fuzzZip, ""})
	})

	for archDir, filesToZip := range archDirs {
	arch := archDir.Base()
	hostOrTarget := filepath.Base(filepath.Dir(archDir.String()))
	builder := android.NewRuleBuilder()
	outputFile := android.PathForOutput(ctx, "fuzz-"+hostOrTarget+"-"+arch+".zip")
	s.packages = append(s.packages, outputFile)

	command := builder.Command().BuiltTool(ctx, "soong_zip").
	Flag("-j").
	FlagWithOutput("-o ", outputFile).
	Flag("-L 0") // No need to try and re-compress the zipfiles.

	for _, fileToZip := range filesToZip {
	if fileToZip.DestinationPathPrefix != "" {
	command.FlagWithArg("-P ", fileToZip.DestinationPathPrefix)
	} else {
	command.Flag("-P ''")
	}
	command.FlagWithInput("-f ", fileToZip.SourceFilePath)
	}

	builder.Build(pctx, ctx, "create-fuzz-package-"+arch+"-"+hostOrTarget,
	"Create fuzz target packages for "+arch+"-"+hostOrTarget)
	}
	}

	func (s *fuzzPackager) MakeVars(ctx android.MakeVarsContext) {
	packages := s.packages.Strings()
	sort.Strings(packages)
	sort.Strings(s.sharedLibInstallStrings)
	// TODO(mitchp): Migrate this to use MakeVarsContext::DistForGoal() when it's
	// ready to handle phony targets created in Soong. In the meantime, this
	// exports the phony 'fuzz' target and dependencies on packages to
	// core/main.mk so that we can use dist-for-goals.
	ctx.Strict("SOONG_FUZZ_PACKAGING_ARCH_MODULES", strings.Join(packages, " "))
	ctx.Strict("FUZZ_TARGET_SHARED_DEPS_INSTALL_PAIRS",
	strings.Join(s.sharedLibInstallStrings, " "))

	// Preallocate the slice of fuzz targets to minimise memory allocations.
	fuzzTargets := make([]string, 0, len(s.fuzzTargets))
	for target, _ := range s.fuzzTargets {
	fuzzTargets = append(fuzzTargets, target)
	}
	sort.Strings(fuzzTargets)
	ctx.Strict("ALL_FUZZ_TARGETS", strings.Join(fuzzTargets, " "))
	}