cc/coverage.go - LeafOS-Project/android_build_soong - Gitiles

 // Copyright 2017 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 (
 	"strconv"

 	"github.com/google/blueprint"

 	"android/soong/android"
 )

 var (
  	clangCoverageHostLdFlags = []string{
  		"-Wl,--no-as-needed",
  		"-Wl,--wrap,open",
  	}
  	clangContinuousCoverageFlags = []string{
  		"-mllvm",
  		"-runtime-counter-relocation",
  	}
  	clangCoverageCFlags = []string{
  		"-Wno-frame-larger-than=",
  	}
  	clangCoverageCommonFlags = []string{
  		"-fcoverage-mapping",
  		"-Wno-pass-failed",
  		"-D__ANDROID_CLANG_COVERAGE__",
  	}
  	clangCoverageHWASanFlags = []string{
  		"-mllvm",
  		"-hwasan-globals=0",
  	}
 )

 const profileInstrFlag = "-fprofile-instr-generate=/data/misc/trace/clang-%p-%m.profraw"

 type CoverageProperties struct {
 	Native_coverage *bool

 	NeedCoverageVariant bool `blueprint:"mutated"`
 	NeedCoverageBuild   bool `blueprint:"mutated"`

 	CoverageEnabled   bool `blueprint:"mutated"`
 	IsCoverageVariant bool `blueprint:"mutated"`
 }

 type coverage struct {
 	Properties CoverageProperties

 	// Whether binaries containing this module need --coverage added to their ldflags
 	linkCoverage bool
 }

 func (cov *coverage) props() []interface{} {
 	return []interface{}{&cov.Properties}
 }

 func getGcovProfileLibraryName(ctx ModuleContextIntf) string {
 	// This function should only ever be called for a cc.Module, so the
 	// following statement should always succeed.
 	// LINT.IfChange
 	if ctx.useSdk() {
 		return "libprofile-extras_ndk"
 	} else {
 		return "libprofile-extras"
 	}
 }

 func getClangProfileLibraryName(ctx ModuleContextIntf) string {
 	if ctx.useSdk() {
 		return "libprofile-clang-extras_ndk"
 	} else if ctx.isCfiAssemblySupportEnabled() {
 		return "libprofile-clang-extras_cfi_support"
 	} else {
 		return "libprofile-clang-extras"
 	}
 	// LINT.ThenChange(library.go)
 }

 func (cov *coverage) deps(ctx DepsContext, deps Deps) Deps {
 	if cov.Properties.NeedCoverageVariant && ctx.Device() {
 		ctx.AddVariationDependencies([]blueprint.Variation{
 			{Mutator: "link", Variation: "static"},
 		}, CoverageDepTag, getGcovProfileLibraryName(ctx))
 		ctx.AddVariationDependencies([]blueprint.Variation{
 			{Mutator: "link", Variation: "static"},
 		}, CoverageDepTag, getClangProfileLibraryName(ctx))
 	}
 	return deps
 }

 func EnableContinuousCoverage(ctx android.BaseModuleContext) bool {
 	return ctx.DeviceConfig().ClangCoverageContinuousMode()
 }

 func (cov *coverage) flags(ctx ModuleContext, flags Flags, deps PathDeps) (Flags, PathDeps) {
 	clangCoverage := ctx.DeviceConfig().ClangCoverageEnabled()
 	gcovCoverage := ctx.DeviceConfig().GcovCoverageEnabled()

 	if !gcovCoverage && !clangCoverage {
 		return flags, deps
 	}

 	if cov.Properties.CoverageEnabled {
 		cov.linkCoverage = true

 		if gcovCoverage {
 			flags.GcovCoverage = true
 			flags.Local.CommonFlags = append(flags.Local.CommonFlags, "--coverage", "-O0")

 			// Override -Wframe-larger-than and non-default optimization
 			// flags that the module may use.
 			flags.Local.CFlags = append(flags.Local.CFlags, "-Wno-frame-larger-than=", "-O0")
 		} else if clangCoverage {
 			flags.Local.CommonFlags = append(flags.Local.CommonFlags, profileInstrFlag)
 			flags.Local.CommonFlags = append(flags.Local.CommonFlags, clangCoverageCommonFlags...)
 			// Override -Wframe-larger-than.  We can expect frame size increase after
 			// coverage instrumentation.
 			flags.Local.CFlags = append(flags.Local.CFlags, clangCoverageCFlags...)
 			if EnableContinuousCoverage(ctx) {
 				flags.Local.CommonFlags = append(flags.Local.CommonFlags, clangContinuousCoverageFlags...)
 			}

 			// http://b/248022906, http://b/247941801  enabling coverage and hwasan-globals
 			// instrumentation together causes duplicate-symbol errors for __llvm_profile_filename.
 			if c, ok := ctx.Module().(*Module); ok && c.sanitize.isSanitizerEnabled(Hwasan) {
 				flags.Local.CommonFlags = append(flags.Local.CommonFlags, clangCoverageHWASanFlags...)
 			}
 		}
 	}

 	// Even if we don't have coverage enabled, if any of our object files were compiled
 	// with coverage, then we need to add --coverage to our ldflags.
 	if !cov.linkCoverage {
 		if ctx.static() && !ctx.staticBinary() {
 			// For static libraries, the only thing that changes our object files
 			// are included whole static libraries, so check to see if any of
 			// those have coverage enabled.
 			ctx.VisitDirectDeps(func(m android.Module) {
 				if depTag, ok := ctx.OtherModuleDependencyTag(m).(libraryDependencyTag); ok {
 					if depTag.static() && depTag.wholeStatic {
 						if cc, ok := m.(*Module); ok && cc.coverage != nil {
 							if cc.coverage.linkCoverage {
 								cov.linkCoverage = true
 							}
 						}
 					}
 				}
 			})
 		} else {
 			// For executables and shared libraries, we need to check all of
 			// our static dependencies.
 			ctx.VisitDirectDeps(func(m android.Module) {
 				cc, ok := m.(*Module)
 				if !ok || cc.coverage == nil {
 					return
 				}

 				if static, ok := cc.linker.(libraryInterface); !ok || !static.static() {
 					return
 				}

 				if cc.coverage.linkCoverage {
 					cov.linkCoverage = true
 				}
 			})
 		}
 	}

 	if cov.linkCoverage {
 		if gcovCoverage {
 			flags.Local.LdFlags = append(flags.Local.LdFlags, "--coverage")

 			if ctx.Device() {
 				coverage := ctx.GetDirectDepWithTag(getGcovProfileLibraryName(ctx), CoverageDepTag).(*Module)
 				deps.WholeStaticLibs = append(deps.WholeStaticLibs, coverage.OutputFile().Path())
 				flags.Local.LdFlags = append(flags.Local.LdFlags, "-Wl,--wrap,getenv")
 			}
 		} else if clangCoverage {
 			flags.Local.LdFlags = append(flags.Local.LdFlags, profileInstrFlag)
 			if EnableContinuousCoverage(ctx) {
 				flags.Local.LdFlags = append(flags.Local.LdFlags, "-Wl,-mllvm=-runtime-counter-relocation")
 			}

 			if ctx.Device() {
 				coverage := ctx.GetDirectDepWithTag(getClangProfileLibraryName(ctx), CoverageDepTag).(*Module)
 				deps.WholeStaticLibs = append(deps.WholeStaticLibs, coverage.OutputFile().Path())
 				flags.Local.LdFlags = append(flags.Local.LdFlags, "-Wl,--wrap,open")
 			}
 		}
 	}

 	return flags, deps
 }

 func (cov *coverage) begin(ctx BaseModuleContext) {
 	if ctx.Host() && !ctx.Os().Linux() {
 		// TODO(dwillemsen): because of -nodefaultlibs, we must depend on libclang_rt.profile-*.a
 		// Just turn off for now.
 	} else {
 		cov.Properties = SetCoverageProperties(ctx, cov.Properties, ctx.nativeCoverage(), ctx.useSdk(), ctx.sdkVersion())
 	}
 }

 func SetCoverageProperties(ctx android.BaseModuleContext, properties CoverageProperties, moduleTypeHasCoverage bool,
 	useSdk bool, sdkVersion string) CoverageProperties {
 	// Coverage is disabled globally
 	if !ctx.DeviceConfig().NativeCoverageEnabled() {
 		return properties
 	}

 	var needCoverageVariant bool
 	var needCoverageBuild bool

 	if moduleTypeHasCoverage {
 		// Check if Native_coverage is set to false.  This property defaults to true.
 		needCoverageVariant = BoolDefault(properties.Native_coverage, true)
 		if useSdk && sdkVersion != "current" {
 			// Native coverage is not supported for SDK versions < 23
 			if fromApi, err := strconv.Atoi(sdkVersion); err == nil && fromApi < 23 {
 				needCoverageVariant = false
 			}
 		}

 		if needCoverageVariant {
 			// Coverage variant is actually built with coverage if enabled for its module path
 			needCoverageBuild = ctx.DeviceConfig().NativeCoverageEnabledForPath(ctx.ModuleDir())
 		}
 	}

 	properties.NeedCoverageBuild = needCoverageBuild
 	properties.NeedCoverageVariant = needCoverageVariant

 	return properties
 }

 type UseCoverage interface {
 	android.Module
 	IsNativeCoverageNeeded(ctx android.IncomingTransitionContext) bool
 }

 // Coverage is an interface for non-CC modules to implement to be mutated for coverage
 type Coverage interface {
 	UseCoverage
 	SetPreventInstall()
 	HideFromMake()
 	MarkAsCoverageVariant(bool)
 	EnableCoverageIfNeeded()
 }

 type coverageTransitionMutator struct{}

 var _ android.TransitionMutator = (*coverageTransitionMutator)(nil)

 func (c coverageTransitionMutator) Split(ctx android.BaseModuleContext) []string {
 	if c, ok := ctx.Module().(*Module); ok && c.coverage != nil {
 		if c.coverage.Properties.NeedCoverageVariant {
 			return []string{"", "cov"}
 		}
 	} else if cov, ok := ctx.Module().(Coverage); ok && cov.IsNativeCoverageNeeded(ctx) {
 		// APEX and Rust modules fall here

 		// Note: variant "" is also created because an APEX can be depended on by another
 		// module which are split into "" and "cov" variants. e.g. when cc_test refers
 		// to an APEX via 'data' property.
 		return []string{"", "cov"}
 	} else if cov, ok := ctx.Module().(UseCoverage); ok && cov.IsNativeCoverageNeeded(ctx) {
 		// Module itself doesn't have to have "cov" variant, but it should use "cov" variants of
 		// deps.
 		return []string{"cov"}
 	}

 	return []string{""}
 }

 func (c coverageTransitionMutator) OutgoingTransition(ctx android.OutgoingTransitionContext, sourceVariation string) string {
 	return sourceVariation
 }

 func (c coverageTransitionMutator) IncomingTransition(ctx android.IncomingTransitionContext, incomingVariation string) string {
 	if c, ok := ctx.Module().(*Module); ok && c.coverage != nil {
 		if !c.coverage.Properties.NeedCoverageVariant {
 			return ""
 		}
 	} else if cov, ok := ctx.Module().(Coverage); ok {
 		if !cov.IsNativeCoverageNeeded(ctx) {
 			return ""
 		}
 	} else if cov, ok := ctx.Module().(UseCoverage); ok && cov.IsNativeCoverageNeeded(ctx) {
 		// Module only has a "cov" variation, so all incoming variations should use "cov".
 		return "cov"
 	} else {
 		return ""
 	}

 	return incomingVariation
 }

 func (c coverageTransitionMutator) Mutate(ctx android.BottomUpMutatorContext, variation string) {
 	if c, ok := ctx.Module().(*Module); ok && c.coverage != nil {
 		if variation == "" && c.coverage.Properties.NeedCoverageVariant {
 			// Setup the non-coverage version and set HideFromMake and
 			// PreventInstall to true.
 			c.coverage.Properties.CoverageEnabled = false
 			c.coverage.Properties.IsCoverageVariant = false
 			c.Properties.HideFromMake = true
 			c.Properties.PreventInstall = true
 		} else if variation == "cov" {
 			// The coverage-enabled version inherits HideFromMake,
 			// PreventInstall from the original module.
 			c.coverage.Properties.CoverageEnabled = c.coverage.Properties.NeedCoverageBuild
 			c.coverage.Properties.IsCoverageVariant = true
 		}
 	} else if cov, ok := ctx.Module().(Coverage); ok && cov.IsNativeCoverageNeeded(ctx) {
 		// APEX and Rust modules fall here

 		// Note: variant "" is also created because an APEX can be depended on by another
 		// module which are split into "" and "cov" variants. e.g. when cc_test refers
 		// to an APEX via 'data' property.
 		if variation == "" {
 			cov.MarkAsCoverageVariant(false)
 			cov.SetPreventInstall()
 			cov.HideFromMake()
 		} else if variation == "cov" {
 			cov.MarkAsCoverageVariant(true)
 			cov.EnableCoverageIfNeeded()
 		}
 	} else if cov, ok := ctx.Module().(UseCoverage); ok && cov.IsNativeCoverageNeeded(ctx) {
 		// Module itself doesn't have to have "cov" variant, but it should use "cov" variants of
 		// deps.
 	}
 }

 func parseSymbolFileForAPICoverage(ctx ModuleContext, symbolFile string) android.ModuleOutPath {
 	apiLevelsJson := android.GetApiLevelsJson(ctx)
 	symbolFilePath := android.PathForModuleSrc(ctx, symbolFile)
 	outputFile := ctx.baseModuleName() + ".xml"
 	parsedApiCoveragePath := android.PathForModuleOut(ctx, outputFile)
 	rule := android.NewRuleBuilder(pctx, ctx)
 	rule.Command().
 		BuiltTool("ndk_api_coverage_parser").
 		Input(symbolFilePath).
 		Output(parsedApiCoveragePath).
 		Implicit(apiLevelsJson).
 		FlagWithArg("--api-map ", apiLevelsJson.String())
 	rule.Build("native_library_api_list", "Generate native API list based on symbol files for coverage measurement")
 	return parsedApiCoveragePath
 }
	// Copyright 2017 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 (
	"strconv"

	"github.com/google/blueprint"

	"android/soong/android"
	)

	var (
	clangCoverageHostLdFlags = []string{
	"-Wl,--no-as-needed",
	"-Wl,--wrap,open",
	}
	clangContinuousCoverageFlags = []string{
	"-mllvm",
	"-runtime-counter-relocation",
	}
	clangCoverageCFlags = []string{
	"-Wno-frame-larger-than=",
	}
	clangCoverageCommonFlags = []string{
	"-fcoverage-mapping",
	"-Wno-pass-failed",
	"-D__ANDROID_CLANG_COVERAGE__",
	}
	clangCoverageHWASanFlags = []string{
	"-mllvm",
	"-hwasan-globals=0",
	}
	)

	const profileInstrFlag = "-fprofile-instr-generate=/data/misc/trace/clang-%p-%m.profraw"

	type CoverageProperties struct {
	Native_coverage *bool

	NeedCoverageVariant bool `blueprint:"mutated"`
	NeedCoverageBuild bool `blueprint:"mutated"`

	CoverageEnabled bool `blueprint:"mutated"`
	IsCoverageVariant bool `blueprint:"mutated"`
	}

	type coverage struct {
	Properties CoverageProperties

	// Whether binaries containing this module need --coverage added to their ldflags
	linkCoverage bool
	}

	func (cov *coverage) props() []interface{} {
	return []interface{}{&cov.Properties}
	}

	func getGcovProfileLibraryName(ctx ModuleContextIntf) string {
	// This function should only ever be called for a cc.Module, so the
	// following statement should always succeed.
	// LINT.IfChange
	if ctx.useSdk() {
	return "libprofile-extras_ndk"
	} else {
	return "libprofile-extras"
	}
	}

	func getClangProfileLibraryName(ctx ModuleContextIntf) string {
	if ctx.useSdk() {
	return "libprofile-clang-extras_ndk"
	} else if ctx.isCfiAssemblySupportEnabled() {
	return "libprofile-clang-extras_cfi_support"
	} else {
	return "libprofile-clang-extras"
	}
	// LINT.ThenChange(library.go)
	}

	func (cov *coverage) deps(ctx DepsContext, deps Deps) Deps {
	if cov.Properties.NeedCoverageVariant && ctx.Device() {
	ctx.AddVariationDependencies([]blueprint.Variation{
	{Mutator: "link", Variation: "static"},
	}, CoverageDepTag, getGcovProfileLibraryName(ctx))
	ctx.AddVariationDependencies([]blueprint.Variation{
	{Mutator: "link", Variation: "static"},
	}, CoverageDepTag, getClangProfileLibraryName(ctx))
	}
	return deps
	}

	func EnableContinuousCoverage(ctx android.BaseModuleContext) bool {
	return ctx.DeviceConfig().ClangCoverageContinuousMode()
	}

	func (cov *coverage) flags(ctx ModuleContext, flags Flags, deps PathDeps) (Flags, PathDeps) {
	clangCoverage := ctx.DeviceConfig().ClangCoverageEnabled()
	gcovCoverage := ctx.DeviceConfig().GcovCoverageEnabled()

	if !gcovCoverage && !clangCoverage {
	return flags, deps
	}

	if cov.Properties.CoverageEnabled {
	cov.linkCoverage = true

	if gcovCoverage {
	flags.GcovCoverage = true
	flags.Local.CommonFlags = append(flags.Local.CommonFlags, "--coverage", "-O0")

	// Override -Wframe-larger-than and non-default optimization
	// flags that the module may use.
	flags.Local.CFlags = append(flags.Local.CFlags, "-Wno-frame-larger-than=", "-O0")
	} else if clangCoverage {
	flags.Local.CommonFlags = append(flags.Local.CommonFlags, profileInstrFlag)
	flags.Local.CommonFlags = append(flags.Local.CommonFlags, clangCoverageCommonFlags...)
	// Override -Wframe-larger-than. We can expect frame size increase after
	// coverage instrumentation.
	flags.Local.CFlags = append(flags.Local.CFlags, clangCoverageCFlags...)
	if EnableContinuousCoverage(ctx) {
	flags.Local.CommonFlags = append(flags.Local.CommonFlags, clangContinuousCoverageFlags...)
	}

	// http://b/248022906, http://b/247941801 enabling coverage and hwasan-globals
	// instrumentation together causes duplicate-symbol errors for __llvm_profile_filename.
	if c, ok := ctx.Module().(*Module); ok && c.sanitize.isSanitizerEnabled(Hwasan) {
	flags.Local.CommonFlags = append(flags.Local.CommonFlags, clangCoverageHWASanFlags...)
	}
	}
	}

	// Even if we don't have coverage enabled, if any of our object files were compiled
	// with coverage, then we need to add --coverage to our ldflags.
	if !cov.linkCoverage {
	if ctx.static() && !ctx.staticBinary() {
	// For static libraries, the only thing that changes our object files
	// are included whole static libraries, so check to see if any of
	// those have coverage enabled.
	ctx.VisitDirectDeps(func(m android.Module) {
	if depTag, ok := ctx.OtherModuleDependencyTag(m).(libraryDependencyTag); ok {
	if depTag.static() && depTag.wholeStatic {
	if cc, ok := m.(*Module); ok && cc.coverage != nil {
	if cc.coverage.linkCoverage {
	cov.linkCoverage = true
	}
	}
	}
	}
	})
	} else {
	// For executables and shared libraries, we need to check all of
	// our static dependencies.
	ctx.VisitDirectDeps(func(m android.Module) {
	cc, ok := m.(*Module)
	if !ok \|\| cc.coverage == nil {
	return
	}

	if static, ok := cc.linker.(libraryInterface); !ok \|\| !static.static() {
	return
	}

	if cc.coverage.linkCoverage {
	cov.linkCoverage = true
	}
	})
	}
	}

	if cov.linkCoverage {
	if gcovCoverage {
	flags.Local.LdFlags = append(flags.Local.LdFlags, "--coverage")

	if ctx.Device() {
	coverage := ctx.GetDirectDepWithTag(getGcovProfileLibraryName(ctx), CoverageDepTag).(*Module)
	deps.WholeStaticLibs = append(deps.WholeStaticLibs, coverage.OutputFile().Path())
	flags.Local.LdFlags = append(flags.Local.LdFlags, "-Wl,--wrap,getenv")
	}
	} else if clangCoverage {
	flags.Local.LdFlags = append(flags.Local.LdFlags, profileInstrFlag)
	if EnableContinuousCoverage(ctx) {
	flags.Local.LdFlags = append(flags.Local.LdFlags, "-Wl,-mllvm=-runtime-counter-relocation")
	}

	if ctx.Device() {
	coverage := ctx.GetDirectDepWithTag(getClangProfileLibraryName(ctx), CoverageDepTag).(*Module)
	deps.WholeStaticLibs = append(deps.WholeStaticLibs, coverage.OutputFile().Path())
	flags.Local.LdFlags = append(flags.Local.LdFlags, "-Wl,--wrap,open")
	}
	}
	}

	return flags, deps
	}

	func (cov *coverage) begin(ctx BaseModuleContext) {
	if ctx.Host() && !ctx.Os().Linux() {
	// TODO(dwillemsen): because of -nodefaultlibs, we must depend on libclang_rt.profile-*.a
	// Just turn off for now.
	} else {
	cov.Properties = SetCoverageProperties(ctx, cov.Properties, ctx.nativeCoverage(), ctx.useSdk(), ctx.sdkVersion())
	}
	}

	func SetCoverageProperties(ctx android.BaseModuleContext, properties CoverageProperties, moduleTypeHasCoverage bool,
	useSdk bool, sdkVersion string) CoverageProperties {
	// Coverage is disabled globally
	if !ctx.DeviceConfig().NativeCoverageEnabled() {
	return properties
	}

	var needCoverageVariant bool
	var needCoverageBuild bool

	if moduleTypeHasCoverage {
	// Check if Native_coverage is set to false. This property defaults to true.
	needCoverageVariant = BoolDefault(properties.Native_coverage, true)
	if useSdk && sdkVersion != "current" {
	// Native coverage is not supported for SDK versions < 23
	if fromApi, err := strconv.Atoi(sdkVersion); err == nil && fromApi < 23 {
	needCoverageVariant = false
	}
	}

	if needCoverageVariant {
	// Coverage variant is actually built with coverage if enabled for its module path
	needCoverageBuild = ctx.DeviceConfig().NativeCoverageEnabledForPath(ctx.ModuleDir())
	}
	}

	properties.NeedCoverageBuild = needCoverageBuild
	properties.NeedCoverageVariant = needCoverageVariant

	return properties
	}

	type UseCoverage interface {
	android.Module
	IsNativeCoverageNeeded(ctx android.IncomingTransitionContext) bool
	}

	// Coverage is an interface for non-CC modules to implement to be mutated for coverage
	type Coverage interface {
	UseCoverage
	SetPreventInstall()
	HideFromMake()
	MarkAsCoverageVariant(bool)
	EnableCoverageIfNeeded()
	}

	type coverageTransitionMutator struct{}

	var _ android.TransitionMutator = (*coverageTransitionMutator)(nil)

	func (c coverageTransitionMutator) Split(ctx android.BaseModuleContext) []string {
	if c, ok := ctx.Module().(*Module); ok && c.coverage != nil {
	if c.coverage.Properties.NeedCoverageVariant {
	return []string{"", "cov"}
	}
	} else if cov, ok := ctx.Module().(Coverage); ok && cov.IsNativeCoverageNeeded(ctx) {
	// APEX and Rust modules fall here

	// Note: variant "" is also created because an APEX can be depended on by another
	// module which are split into "" and "cov" variants. e.g. when cc_test refers
	// to an APEX via 'data' property.
	return []string{"", "cov"}
	} else if cov, ok := ctx.Module().(UseCoverage); ok && cov.IsNativeCoverageNeeded(ctx) {
	// Module itself doesn't have to have "cov" variant, but it should use "cov" variants of
	// deps.
	return []string{"cov"}
	}

	return []string{""}
	}

	func (c coverageTransitionMutator) OutgoingTransition(ctx android.OutgoingTransitionContext, sourceVariation string) string {
	return sourceVariation
	}

	func (c coverageTransitionMutator) IncomingTransition(ctx android.IncomingTransitionContext, incomingVariation string) string {
	if c, ok := ctx.Module().(*Module); ok && c.coverage != nil {
	if !c.coverage.Properties.NeedCoverageVariant {
	return ""
	}
	} else if cov, ok := ctx.Module().(Coverage); ok {
	if !cov.IsNativeCoverageNeeded(ctx) {
	return ""
	}
	} else if cov, ok := ctx.Module().(UseCoverage); ok && cov.IsNativeCoverageNeeded(ctx) {
	// Module only has a "cov" variation, so all incoming variations should use "cov".
	return "cov"
	} else {
	return ""
	}

	return incomingVariation
	}

	func (c coverageTransitionMutator) Mutate(ctx android.BottomUpMutatorContext, variation string) {
	if c, ok := ctx.Module().(*Module); ok && c.coverage != nil {
	if variation == "" && c.coverage.Properties.NeedCoverageVariant {
	// Setup the non-coverage version and set HideFromMake and
	// PreventInstall to true.
	c.coverage.Properties.CoverageEnabled = false
	c.coverage.Properties.IsCoverageVariant = false
	c.Properties.HideFromMake = true
	c.Properties.PreventInstall = true
	} else if variation == "cov" {
	// The coverage-enabled version inherits HideFromMake,
	// PreventInstall from the original module.
	c.coverage.Properties.CoverageEnabled = c.coverage.Properties.NeedCoverageBuild
	c.coverage.Properties.IsCoverageVariant = true
	}
	} else if cov, ok := ctx.Module().(Coverage); ok && cov.IsNativeCoverageNeeded(ctx) {
	// APEX and Rust modules fall here

	// Note: variant "" is also created because an APEX can be depended on by another
	// module which are split into "" and "cov" variants. e.g. when cc_test refers
	// to an APEX via 'data' property.
	if variation == "" {
	cov.MarkAsCoverageVariant(false)
	cov.SetPreventInstall()
	cov.HideFromMake()
	} else if variation == "cov" {
	cov.MarkAsCoverageVariant(true)
	cov.EnableCoverageIfNeeded()
	}
	} else if cov, ok := ctx.Module().(UseCoverage); ok && cov.IsNativeCoverageNeeded(ctx) {
	// Module itself doesn't have to have "cov" variant, but it should use "cov" variants of
	// deps.
	}
	}

	func parseSymbolFileForAPICoverage(ctx ModuleContext, symbolFile string) android.ModuleOutPath {
	apiLevelsJson := android.GetApiLevelsJson(ctx)
	symbolFilePath := android.PathForModuleSrc(ctx, symbolFile)
	outputFile := ctx.baseModuleName() + ".xml"
	parsedApiCoveragePath := android.PathForModuleOut(ctx, outputFile)
	rule := android.NewRuleBuilder(pctx, ctx)
	rule.Command().
	BuiltTool("ndk_api_coverage_parser").
	Input(symbolFilePath).
	Output(parsedApiCoveragePath).
	Implicit(apiLevelsJson).
	FlagWithArg("--api-map ", apiLevelsJson.String())
	rule.Build("native_library_api_list", "Generate native API list based on symbol files for coverage measurement")
	return parsedApiCoveragePath
	}