bazel/properties.go - platform/build/soong - Git at Google

 // Copyright 2020 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 bazel

 import (
 	"fmt"
 	"path/filepath"
 	"regexp"
 	"sort"
 )

 // BazelTargetModuleProperties contain properties and metadata used for
 // Blueprint to BUILD file conversion.
 type BazelTargetModuleProperties struct {
 	// The Bazel rule class for this target.
 	Rule_class string `blueprint:"mutated"`

 	// The target label for the bzl file containing the definition of the rule class.
 	Bzl_load_location string `blueprint:"mutated"`
 }

 const BazelTargetModuleNamePrefix = "__bp2build__"

 var productVariableSubstitutionPattern = regexp.MustCompile("%(d|s)")

 // Label is used to represent a Bazel compatible Label. Also stores the original
 // bp text to support string replacement.
 type Label struct {
 	// The string representation of a Bazel target label. This can be a relative
 	// or fully qualified label. These labels are used for generating BUILD
 	// files with bp2build.
 	Label string

 	// The original Soong/Blueprint module name that the label was derived from.
 	// This is used for replacing references to the original name with the new
 	// label, for example in genrule cmds.
 	//
 	// While there is a reversible 1:1 mapping from the module name to Bazel
 	// label with bp2build that could make computing the original module name
 	// from the label automatic, it is not the case for handcrafted targets,
 	// where modules can have a custom label mapping through the { bazel_module:
 	// { label: <label> } } property.
 	//
 	// With handcrafted labels, those modules don't go through bp2build
 	// conversion, but relies on handcrafted targets in the source tree.
 	OriginalModuleName string
 }

 // LabelList is used to represent a list of Bazel labels.
 type LabelList struct {
 	Includes []Label
 	Excludes []Label
 }

 // uniqueParentDirectories returns a list of the unique parent directories for
 // all files in ll.Includes.
 func (ll *LabelList) uniqueParentDirectories() []string {
 	dirMap := map[string]bool{}
 	for _, label := range ll.Includes {
 		dirMap[filepath.Dir(label.Label)] = true
 	}
 	dirs := []string{}
 	for dir := range dirMap {
 		dirs = append(dirs, dir)
 	}
 	return dirs
 }

 // Append appends the fields of other labelList to the corresponding fields of ll.
 func (ll *LabelList) Append(other LabelList) {
 	if len(ll.Includes) > 0 || len(other.Includes) > 0 {
 		ll.Includes = append(ll.Includes, other.Includes...)
 	}
 	if len(ll.Excludes) > 0 || len(other.Excludes) > 0 {
 		ll.Excludes = append(other.Excludes, other.Excludes...)
 	}
 }

 // UniqueSortedBazelLabels takes a []Label and deduplicates the labels, and returns
 // the slice in a sorted order.
 func UniqueSortedBazelLabels(originalLabels []Label) []Label {
 	uniqueLabelsSet := make(map[Label]bool)
 	for _, l := range originalLabels {
 		uniqueLabelsSet[l] = true
 	}
 	var uniqueLabels []Label
 	for l, _ := range uniqueLabelsSet {
 		uniqueLabels = append(uniqueLabels, l)
 	}
 	sort.SliceStable(uniqueLabels, func(i, j int) bool {
 		return uniqueLabels[i].Label < uniqueLabels[j].Label
 	})
 	return uniqueLabels
 }

 func UniqueBazelLabelList(originalLabelList LabelList) LabelList {
 	var uniqueLabelList LabelList
 	uniqueLabelList.Includes = UniqueSortedBazelLabels(originalLabelList.Includes)
 	uniqueLabelList.Excludes = UniqueSortedBazelLabels(originalLabelList.Excludes)
 	return uniqueLabelList
 }

 // Subtract needle from haystack
 func SubtractStrings(haystack []string, needle []string) []string {
 	// This is really a set
 	remainder := make(map[string]bool)

 	for _, s := range haystack {
 		remainder[s] = true
 	}
 	for _, s := range needle {
 		delete(remainder, s)
 	}

 	var strings []string
 	for s, _ := range remainder {
 		strings = append(strings, s)
 	}

 	sort.SliceStable(strings, func(i, j int) bool {
 		return strings[i] < strings[j]
 	})

 	return strings
 }

 // Subtract needle from haystack
 func SubtractBazelLabels(haystack []Label, needle []Label) []Label {
 	// This is really a set
 	remainder := make(map[Label]bool)

 	for _, label := range haystack {
 		remainder[label] = true
 	}
 	for _, label := range needle {
 		delete(remainder, label)
 	}

 	var labels []Label
 	for label, _ := range remainder {
 		labels = append(labels, label)
 	}

 	sort.SliceStable(labels, func(i, j int) bool {
 		return labels[i].Label < labels[j].Label
 	})

 	return labels
 }

 // Subtract needle from haystack
 func SubtractBazelLabelList(haystack LabelList, needle LabelList) LabelList {
 	var result LabelList
 	result.Includes = SubtractBazelLabels(haystack.Includes, needle.Includes)
 	// NOTE: Excludes are intentionally not subtracted
 	result.Excludes = haystack.Excludes
 	return result
 }

 const (
 	// ArchType names in arch.go
 	ARCH_ARM    = "arm"
 	ARCH_ARM64  = "arm64"
 	ARCH_X86    = "x86"
 	ARCH_X86_64 = "x86_64"

 	// OsType names in arch.go
 	OS_ANDROID      = "android"
 	OS_DARWIN       = "darwin"
 	OS_FUCHSIA      = "fuchsia"
 	OS_LINUX        = "linux_glibc"
 	OS_LINUX_BIONIC = "linux_bionic"
 	OS_WINDOWS      = "windows"

 	// This is the string representation of the default condition wherever a
 	// configurable attribute is used in a select statement, i.e.
 	// //conditions:default for Bazel.
 	//
 	// This is consistently named "conditions_default" to mirror the Soong
 	// config variable default key in an Android.bp file, although there's no
 	// integration with Soong config variables (yet).
 	CONDITIONS_DEFAULT = "conditions_default"
 )

 var (
 	// These are the list of OSes and architectures with a Bazel config_setting
 	// and constraint value equivalent. These exist in arch.go, but the android
 	// package depends on the bazel package, so a cyclic dependency prevents
 	// using those variables here.

 	// A map of architectures to the Bazel label of the constraint_value
 	// for the @platforms//cpu:cpu constraint_setting
 	PlatformArchMap = map[string]string{
 		ARCH_ARM:           "//build/bazel/platforms/arch:arm",
 		ARCH_ARM64:         "//build/bazel/platforms/arch:arm64",
 		ARCH_X86:           "//build/bazel/platforms/arch:x86",
 		ARCH_X86_64:        "//build/bazel/platforms/arch:x86_64",
 		CONDITIONS_DEFAULT: "//conditions:default", // The default condition of as arch select map.
 	}

 	// A map of target operating systems to the Bazel label of the
 	// constraint_value for the @platforms//os:os constraint_setting
 	PlatformOsMap = map[string]string{
 		OS_ANDROID:         "//build/bazel/platforms/os:android",
 		OS_DARWIN:          "//build/bazel/platforms/os:darwin",
 		OS_FUCHSIA:         "//build/bazel/platforms/os:fuchsia",
 		OS_LINUX:           "//build/bazel/platforms/os:linux",
 		OS_LINUX_BIONIC:    "//build/bazel/platforms/os:linux_bionic",
 		OS_WINDOWS:         "//build/bazel/platforms/os:windows",
 		CONDITIONS_DEFAULT: "//conditions:default", // The default condition of an os select map.
 	}
 )

 type Attribute interface {
 	HasConfigurableValues() bool
 }

 // Represents an attribute whose value is a single label
 type LabelAttribute struct {
 	Value  Label
 	X86    Label
 	X86_64 Label
 	Arm    Label
 	Arm64  Label
 }

 func (attr *LabelAttribute) GetValueForArch(arch string) Label {
 	switch arch {
 	case ARCH_ARM:
 		return attr.Arm
 	case ARCH_ARM64:
 		return attr.Arm64
 	case ARCH_X86:
 		return attr.X86
 	case ARCH_X86_64:
 		return attr.X86_64
 	case CONDITIONS_DEFAULT:
 		return attr.Value
 	default:
 		panic("Invalid arch type")
 	}
 }

 func (attr *LabelAttribute) SetValueForArch(arch string, value Label) {
 	switch arch {
 	case ARCH_ARM:
 		attr.Arm = value
 	case ARCH_ARM64:
 		attr.Arm64 = value
 	case ARCH_X86:
 		attr.X86 = value
 	case ARCH_X86_64:
 		attr.X86_64 = value
 	default:
 		panic("Invalid arch type")
 	}
 }

 func (attr LabelAttribute) HasConfigurableValues() bool {
 	return attr.Arm.Label != "" || attr.Arm64.Label != "" || attr.X86.Label != "" || attr.X86_64.Label != ""
 }

 // Arch-specific label_list typed Bazel attribute values. This should correspond
 // to the types of architectures supported for compilation in arch.go.
 type labelListArchValues struct {
 	X86    LabelList
 	X86_64 LabelList
 	Arm    LabelList
 	Arm64  LabelList
 	Common LabelList

 	ConditionsDefault LabelList
 }

 type labelListOsValues struct {
 	Android     LabelList
 	Darwin      LabelList
 	Fuchsia     LabelList
 	Linux       LabelList
 	LinuxBionic LabelList
 	Windows     LabelList

 	ConditionsDefault LabelList
 }

 // LabelListAttribute is used to represent a list of Bazel labels as an
 // attribute.
 type LabelListAttribute struct {
 	// The non-arch specific attribute label list Value. Required.
 	Value LabelList

 	// The arch-specific attribute label list values. Optional. If used, these
 	// are generated in a select statement and appended to the non-arch specific
 	// label list Value.
 	ArchValues labelListArchValues

 	// The os-specific attribute label list values. Optional. If used, these
 	// are generated in a select statement and appended to the non-os specific
 	// label list Value.
 	OsValues labelListOsValues
 }

 // MakeLabelListAttribute initializes a LabelListAttribute with the non-arch specific value.
 func MakeLabelListAttribute(value LabelList) LabelListAttribute {
 	return LabelListAttribute{Value: UniqueBazelLabelList(value)}
 }

 // Append all values, including os and arch specific ones, from another
 // LabelListAttribute to this LabelListAttribute.
 func (attrs *LabelListAttribute) Append(other LabelListAttribute) {
 	for arch := range PlatformArchMap {
 		this := attrs.GetValueForArch(arch)
 		that := other.GetValueForArch(arch)
 		this.Append(that)
 		attrs.SetValueForArch(arch, this)
 	}

 	for os := range PlatformOsMap {
 		this := attrs.GetValueForOS(os)
 		that := other.GetValueForOS(os)
 		this.Append(that)
 		attrs.SetValueForOS(os, this)
 	}

 	attrs.Value.Append(other.Value)
 }

 // HasArchSpecificValues returns true if the attribute contains
 // architecture-specific label_list values.
 func (attrs LabelListAttribute) HasConfigurableValues() bool {
 	for arch := range PlatformArchMap {
 		if len(attrs.GetValueForArch(arch).Includes) > 0 {
 			return true
 		}
 	}

 	for os := range PlatformOsMap {
 		if len(attrs.GetValueForOS(os).Includes) > 0 {
 			return true
 		}
 	}
 	return false
 }

 func (attrs *LabelListAttribute) archValuePtrs() map[string]*LabelList {
 	return map[string]*LabelList{
 		ARCH_X86:           &attrs.ArchValues.X86,
 		ARCH_X86_64:        &attrs.ArchValues.X86_64,
 		ARCH_ARM:           &attrs.ArchValues.Arm,
 		ARCH_ARM64:         &attrs.ArchValues.Arm64,
 		CONDITIONS_DEFAULT: &attrs.ArchValues.ConditionsDefault,
 	}
 }

 // GetValueForArch returns the label_list attribute value for an architecture.
 func (attrs *LabelListAttribute) GetValueForArch(arch string) LabelList {
 	var v *LabelList
 	if v = attrs.archValuePtrs()[arch]; v == nil {
 		panic(fmt.Errorf("Unknown arch: %s", arch))
 	}
 	return *v
 }

 // SetValueForArch sets the label_list attribute value for an architecture.
 func (attrs *LabelListAttribute) SetValueForArch(arch string, value LabelList) {
 	var v *LabelList
 	if v = attrs.archValuePtrs()[arch]; v == nil {
 		panic(fmt.Errorf("Unknown arch: %s", arch))
 	}
 	*v = value
 }

 func (attrs *LabelListAttribute) osValuePtrs() map[string]*LabelList {
 	return map[string]*LabelList{
 		OS_ANDROID:         &attrs.OsValues.Android,
 		OS_DARWIN:          &attrs.OsValues.Darwin,
 		OS_FUCHSIA:         &attrs.OsValues.Fuchsia,
 		OS_LINUX:           &attrs.OsValues.Linux,
 		OS_LINUX_BIONIC:    &attrs.OsValues.LinuxBionic,
 		OS_WINDOWS:         &attrs.OsValues.Windows,
 		CONDITIONS_DEFAULT: &attrs.OsValues.ConditionsDefault,
 	}
 }

 // GetValueForOS returns the label_list attribute value for an OS target.
 func (attrs *LabelListAttribute) GetValueForOS(os string) LabelList {
 	var v *LabelList
 	if v = attrs.osValuePtrs()[os]; v == nil {
 		panic(fmt.Errorf("Unknown os: %s", os))
 	}
 	return *v
 }

 // SetValueForArch sets the label_list attribute value for an OS target.
 func (attrs *LabelListAttribute) SetValueForOS(os string, value LabelList) {
 	var v *LabelList
 	if v = attrs.osValuePtrs()[os]; v == nil {
 		panic(fmt.Errorf("Unknown os: %s", os))
 	}
 	*v = value
 }

 // StringListAttribute corresponds to the string_list Bazel attribute type with
 // support for additional metadata, like configurations.
 type StringListAttribute struct {
 	// The base value of the string list attribute.
 	Value []string

 	// The arch-specific attribute string list values. Optional. If used, these
 	// are generated in a select statement and appended to the non-arch specific
 	// label list Value.
 	ArchValues stringListArchValues

 	// The os-specific attribute string list values. Optional. If used, these
 	// are generated in a select statement and appended to the non-os specific
 	// label list Value.
 	OsValues stringListOsValues
 }

 // MakeStringListAttribute initializes a StringListAttribute with the non-arch specific value.
 func MakeStringListAttribute(value []string) StringListAttribute {
 	// NOTE: These strings are not necessarily unique or sorted.
 	return StringListAttribute{Value: value}
 }

 // Arch-specific string_list typed Bazel attribute values. This should correspond
 // to the types of architectures supported for compilation in arch.go.
 type stringListArchValues struct {
 	X86    []string
 	X86_64 []string
 	Arm    []string
 	Arm64  []string
 	Common []string

 	ConditionsDefault []string
 }

 type stringListOsValues struct {
 	Android     []string
 	Darwin      []string
 	Fuchsia     []string
 	Linux       []string
 	LinuxBionic []string
 	Windows     []string

 	ConditionsDefault []string
 }

 // HasConfigurableValues returns true if the attribute contains
 // architecture-specific string_list values.
 func (attrs StringListAttribute) HasConfigurableValues() bool {
 	for arch := range PlatformArchMap {
 		if len(attrs.GetValueForArch(arch)) > 0 {
 			return true
 		}
 	}

 	for os := range PlatformOsMap {
 		if len(attrs.GetValueForOS(os)) > 0 {
 			return true
 		}
 	}
 	return false
 }

 func (attrs *StringListAttribute) archValuePtrs() map[string]*[]string {
 	return map[string]*[]string{
 		ARCH_X86:           &attrs.ArchValues.X86,
 		ARCH_X86_64:        &attrs.ArchValues.X86_64,
 		ARCH_ARM:           &attrs.ArchValues.Arm,
 		ARCH_ARM64:         &attrs.ArchValues.Arm64,
 		CONDITIONS_DEFAULT: &attrs.ArchValues.ConditionsDefault,
 	}
 }

 // GetValueForArch returns the string_list attribute value for an architecture.
 func (attrs *StringListAttribute) GetValueForArch(arch string) []string {
 	var v *[]string
 	if v = attrs.archValuePtrs()[arch]; v == nil {
 		panic(fmt.Errorf("Unknown arch: %s", arch))
 	}
 	return *v
 }

 // SetValueForArch sets the string_list attribute value for an architecture.
 func (attrs *StringListAttribute) SetValueForArch(arch string, value []string) {
 	var v *[]string
 	if v = attrs.archValuePtrs()[arch]; v == nil {
 		panic(fmt.Errorf("Unknown arch: %s", arch))
 	}
 	*v = value
 }

 func (attrs *StringListAttribute) osValuePtrs() map[string]*[]string {
 	return map[string]*[]string{
 		OS_ANDROID:         &attrs.OsValues.Android,
 		OS_DARWIN:          &attrs.OsValues.Darwin,
 		OS_FUCHSIA:         &attrs.OsValues.Fuchsia,
 		OS_LINUX:           &attrs.OsValues.Linux,
 		OS_LINUX_BIONIC:    &attrs.OsValues.LinuxBionic,
 		OS_WINDOWS:         &attrs.OsValues.Windows,
 		CONDITIONS_DEFAULT: &attrs.OsValues.ConditionsDefault,
 	}
 }

 // GetValueForOS returns the string_list attribute value for an OS target.
 func (attrs *StringListAttribute) GetValueForOS(os string) []string {
 	var v *[]string
 	if v = attrs.osValuePtrs()[os]; v == nil {
 		panic(fmt.Errorf("Unknown os: %s", os))
 	}
 	return *v
 }

 // SetValueForArch sets the string_list attribute value for an OS target.
 func (attrs *StringListAttribute) SetValueForOS(os string, value []string) {
 	var v *[]string
 	if v = attrs.osValuePtrs()[os]; v == nil {
 		panic(fmt.Errorf("Unknown os: %s", os))
 	}
 	*v = value
 }

 // Append appends all values, including os and arch specific ones, from another
 // StringListAttribute to this StringListAttribute
 func (attrs *StringListAttribute) Append(other StringListAttribute) {
 	for arch := range PlatformArchMap {
 		this := attrs.GetValueForArch(arch)
 		that := other.GetValueForArch(arch)
 		this = append(this, that...)
 		attrs.SetValueForArch(arch, this)
 	}

 	for os := range PlatformOsMap {
 		this := attrs.GetValueForOS(os)
 		that := other.GetValueForOS(os)
 		this = append(this, that...)
 		attrs.SetValueForOS(os, this)
 	}

 	attrs.Value = append(attrs.Value, other.Value...)
 }

 // TryVariableSubstitution, replace string substitution formatting within each string in slice with
 // Starlark string.format compatible tag for productVariable.
 func TryVariableSubstitutions(slice []string, productVariable string) ([]string, bool) {
 	ret := make([]string, 0, len(slice))
 	changesMade := false
 	for _, s := range slice {
 		newS, changed := TryVariableSubstitution(s, productVariable)
 		ret = append(ret, newS)
 		changesMade = changesMade || changed
 	}
 	return ret, changesMade
 }

 // TryVariableSubstitution, replace string substitution formatting within s with Starlark
 // string.format compatible tag for productVariable.
 func TryVariableSubstitution(s string, productVariable string) (string, bool) {
 	sub := productVariableSubstitutionPattern.ReplaceAllString(s, "{"+productVariable+"}")
 	return sub, s != sub
 }
	// Copyright 2020 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 bazel

	import (
	"fmt"
	"path/filepath"
	"regexp"
	"sort"
	)

	// BazelTargetModuleProperties contain properties and metadata used for
	// Blueprint to BUILD file conversion.
	type BazelTargetModuleProperties struct {
	// The Bazel rule class for this target.
	Rule_class string `blueprint:"mutated"`

	// The target label for the bzl file containing the definition of the rule class.
	Bzl_load_location string `blueprint:"mutated"`
	}

	const BazelTargetModuleNamePrefix = "__bp2build__"

	var productVariableSubstitutionPattern = regexp.MustCompile("%(d\|s)")

	// Label is used to represent a Bazel compatible Label. Also stores the original
	// bp text to support string replacement.
	type Label struct {
	// The string representation of a Bazel target label. This can be a relative
	// or fully qualified label. These labels are used for generating BUILD
	// files with bp2build.
	Label string

	// The original Soong/Blueprint module name that the label was derived from.
	// This is used for replacing references to the original name with the new
	// label, for example in genrule cmds.
	//
	// While there is a reversible 1:1 mapping from the module name to Bazel
	// label with bp2build that could make computing the original module name
	// from the label automatic, it is not the case for handcrafted targets,
	// where modules can have a custom label mapping through the { bazel_module:
	// { label: <label> } } property.
	//
	// With handcrafted labels, those modules don't go through bp2build
	// conversion, but relies on handcrafted targets in the source tree.
	OriginalModuleName string
	}

	// LabelList is used to represent a list of Bazel labels.
	type LabelList struct {
	Includes []Label
	Excludes []Label
	}

	// uniqueParentDirectories returns a list of the unique parent directories for
	// all files in ll.Includes.
	func (ll *LabelList) uniqueParentDirectories() []string {
	dirMap := map[string]bool{}
	for _, label := range ll.Includes {
	dirMap[filepath.Dir(label.Label)] = true
	}
	dirs := []string{}
	for dir := range dirMap {
	dirs = append(dirs, dir)
	}
	return dirs
	}

	// Append appends the fields of other labelList to the corresponding fields of ll.
	func (ll *LabelList) Append(other LabelList) {
	if len(ll.Includes) > 0 \|\| len(other.Includes) > 0 {
	ll.Includes = append(ll.Includes, other.Includes...)
	}
	if len(ll.Excludes) > 0 \|\| len(other.Excludes) > 0 {
	ll.Excludes = append(other.Excludes, other.Excludes...)
	}
	}

	// UniqueSortedBazelLabels takes a []Label and deduplicates the labels, and returns
	// the slice in a sorted order.
	func UniqueSortedBazelLabels(originalLabels []Label) []Label {
	uniqueLabelsSet := make(map[Label]bool)
	for _, l := range originalLabels {
	uniqueLabelsSet[l] = true
	}
	var uniqueLabels []Label
	for l, _ := range uniqueLabelsSet {
	uniqueLabels = append(uniqueLabels, l)
	}
	sort.SliceStable(uniqueLabels, func(i, j int) bool {
	return uniqueLabels[i].Label < uniqueLabels[j].Label
	})
	return uniqueLabels
	}

	func UniqueBazelLabelList(originalLabelList LabelList) LabelList {
	var uniqueLabelList LabelList
	uniqueLabelList.Includes = UniqueSortedBazelLabels(originalLabelList.Includes)
	uniqueLabelList.Excludes = UniqueSortedBazelLabels(originalLabelList.Excludes)
	return uniqueLabelList
	}

	// Subtract needle from haystack
	func SubtractStrings(haystack []string, needle []string) []string {
	// This is really a set
	remainder := make(map[string]bool)

	for _, s := range haystack {
	remainder[s] = true
	}
	for _, s := range needle {
	delete(remainder, s)
	}

	var strings []string
	for s, _ := range remainder {
	strings = append(strings, s)
	}

	sort.SliceStable(strings, func(i, j int) bool {
	return strings[i] < strings[j]
	})

	return strings
	}

	// Subtract needle from haystack
	func SubtractBazelLabels(haystack []Label, needle []Label) []Label {
	// This is really a set
	remainder := make(map[Label]bool)

	for _, label := range haystack {
	remainder[label] = true
	}
	for _, label := range needle {
	delete(remainder, label)
	}

	var labels []Label
	for label, _ := range remainder {
	labels = append(labels, label)
	}

	sort.SliceStable(labels, func(i, j int) bool {
	return labels[i].Label < labels[j].Label
	})

	return labels
	}

	// Subtract needle from haystack
	func SubtractBazelLabelList(haystack LabelList, needle LabelList) LabelList {
	var result LabelList
	result.Includes = SubtractBazelLabels(haystack.Includes, needle.Includes)
	// NOTE: Excludes are intentionally not subtracted
	result.Excludes = haystack.Excludes
	return result
	}

	const (
	// ArchType names in arch.go
	ARCH_ARM = "arm"
	ARCH_ARM64 = "arm64"
	ARCH_X86 = "x86"
	ARCH_X86_64 = "x86_64"

	// OsType names in arch.go
	OS_ANDROID = "android"
	OS_DARWIN = "darwin"
	OS_FUCHSIA = "fuchsia"
	OS_LINUX = "linux_glibc"
	OS_LINUX_BIONIC = "linux_bionic"
	OS_WINDOWS = "windows"

	// This is the string representation of the default condition wherever a
	// configurable attribute is used in a select statement, i.e.
	// //conditions:default for Bazel.
	//
	// This is consistently named "conditions_default" to mirror the Soong
	// config variable default key in an Android.bp file, although there's no
	// integration with Soong config variables (yet).
	CONDITIONS_DEFAULT = "conditions_default"
	)

	var (
	// These are the list of OSes and architectures with a Bazel config_setting
	// and constraint value equivalent. These exist in arch.go, but the android
	// package depends on the bazel package, so a cyclic dependency prevents
	// using those variables here.

	// A map of architectures to the Bazel label of the constraint_value
	// for the @platforms//cpu:cpu constraint_setting
	PlatformArchMap = map[string]string{
	ARCH_ARM: "//build/bazel/platforms/arch:arm",
	ARCH_ARM64: "//build/bazel/platforms/arch:arm64",
	ARCH_X86: "//build/bazel/platforms/arch:x86",
	ARCH_X86_64: "//build/bazel/platforms/arch:x86_64",
	CONDITIONS_DEFAULT: "//conditions:default", // The default condition of as arch select map.
	}

	// A map of target operating systems to the Bazel label of the
	// constraint_value for the @platforms//os:os constraint_setting
	PlatformOsMap = map[string]string{
	OS_ANDROID: "//build/bazel/platforms/os:android",
	OS_DARWIN: "//build/bazel/platforms/os:darwin",
	OS_FUCHSIA: "//build/bazel/platforms/os:fuchsia",
	OS_LINUX: "//build/bazel/platforms/os:linux",
	OS_LINUX_BIONIC: "//build/bazel/platforms/os:linux_bionic",
	OS_WINDOWS: "//build/bazel/platforms/os:windows",
	CONDITIONS_DEFAULT: "//conditions:default", // The default condition of an os select map.
	}
	)

	type Attribute interface {
	HasConfigurableValues() bool
	}

	// Represents an attribute whose value is a single label
	type LabelAttribute struct {
	Value Label
	X86 Label
	X86_64 Label
	Arm Label
	Arm64 Label
	}

	func (attr *LabelAttribute) GetValueForArch(arch string) Label {
	switch arch {
	case ARCH_ARM:
	return attr.Arm
	case ARCH_ARM64:
	return attr.Arm64
	case ARCH_X86:
	return attr.X86
	case ARCH_X86_64:
	return attr.X86_64
	case CONDITIONS_DEFAULT:
	return attr.Value
	default:
	panic("Invalid arch type")
	}
	}

	func (attr *LabelAttribute) SetValueForArch(arch string, value Label) {
	switch arch {
	case ARCH_ARM:
	attr.Arm = value
	case ARCH_ARM64:
	attr.Arm64 = value
	case ARCH_X86:
	attr.X86 = value
	case ARCH_X86_64:
	attr.X86_64 = value
	default:
	panic("Invalid arch type")
	}
	}

	func (attr LabelAttribute) HasConfigurableValues() bool {
	return attr.Arm.Label != "" \|\| attr.Arm64.Label != "" \|\| attr.X86.Label != "" \|\| attr.X86_64.Label != ""
	}

	// Arch-specific label_list typed Bazel attribute values. This should correspond
	// to the types of architectures supported for compilation in arch.go.
	type labelListArchValues struct {
	X86 LabelList
	X86_64 LabelList
	Arm LabelList
	Arm64 LabelList
	Common LabelList

	ConditionsDefault LabelList
	}

	type labelListOsValues struct {
	Android LabelList
	Darwin LabelList
	Fuchsia LabelList
	Linux LabelList
	LinuxBionic LabelList
	Windows LabelList

	ConditionsDefault LabelList
	}

	// LabelListAttribute is used to represent a list of Bazel labels as an
	// attribute.
	type LabelListAttribute struct {
	// The non-arch specific attribute label list Value. Required.
	Value LabelList

	// The arch-specific attribute label list values. Optional. If used, these
	// are generated in a select statement and appended to the non-arch specific
	// label list Value.
	ArchValues labelListArchValues

	// The os-specific attribute label list values. Optional. If used, these
	// are generated in a select statement and appended to the non-os specific
	// label list Value.
	OsValues labelListOsValues
	}

	// MakeLabelListAttribute initializes a LabelListAttribute with the non-arch specific value.
	func MakeLabelListAttribute(value LabelList) LabelListAttribute {
	return LabelListAttribute{Value: UniqueBazelLabelList(value)}
	}

	// Append all values, including os and arch specific ones, from another
	// LabelListAttribute to this LabelListAttribute.
	func (attrs *LabelListAttribute) Append(other LabelListAttribute) {
	for arch := range PlatformArchMap {
	this := attrs.GetValueForArch(arch)
	that := other.GetValueForArch(arch)
	this.Append(that)
	attrs.SetValueForArch(arch, this)
	}

	for os := range PlatformOsMap {
	this := attrs.GetValueForOS(os)
	that := other.GetValueForOS(os)
	this.Append(that)
	attrs.SetValueForOS(os, this)
	}

	attrs.Value.Append(other.Value)
	}

	// HasArchSpecificValues returns true if the attribute contains
	// architecture-specific label_list values.
	func (attrs LabelListAttribute) HasConfigurableValues() bool {
	for arch := range PlatformArchMap {
	if len(attrs.GetValueForArch(arch).Includes) > 0 {
	return true
	}
	}

	for os := range PlatformOsMap {
	if len(attrs.GetValueForOS(os).Includes) > 0 {
	return true
	}
	}
	return false
	}

	func (attrs LabelListAttribute) archValuePtrs() map[string]LabelList {
	return map[string]*LabelList{
	ARCH_X86: &attrs.ArchValues.X86,
	ARCH_X86_64: &attrs.ArchValues.X86_64,
	ARCH_ARM: &attrs.ArchValues.Arm,
	ARCH_ARM64: &attrs.ArchValues.Arm64,
	CONDITIONS_DEFAULT: &attrs.ArchValues.ConditionsDefault,
	}
	}

	// GetValueForArch returns the label_list attribute value for an architecture.
	func (attrs *LabelListAttribute) GetValueForArch(arch string) LabelList {
	var v *LabelList
	if v = attrs.archValuePtrs()[arch]; v == nil {
	panic(fmt.Errorf("Unknown arch: %s", arch))
	}
	return *v
	}

	// SetValueForArch sets the label_list attribute value for an architecture.
	func (attrs *LabelListAttribute) SetValueForArch(arch string, value LabelList) {
	var v *LabelList
	if v = attrs.archValuePtrs()[arch]; v == nil {
	panic(fmt.Errorf("Unknown arch: %s", arch))
	}
	*v = value
	}

	func (attrs LabelListAttribute) osValuePtrs() map[string]LabelList {
	return map[string]*LabelList{
	OS_ANDROID: &attrs.OsValues.Android,
	OS_DARWIN: &attrs.OsValues.Darwin,
	OS_FUCHSIA: &attrs.OsValues.Fuchsia,
	OS_LINUX: &attrs.OsValues.Linux,
	OS_LINUX_BIONIC: &attrs.OsValues.LinuxBionic,
	OS_WINDOWS: &attrs.OsValues.Windows,
	CONDITIONS_DEFAULT: &attrs.OsValues.ConditionsDefault,
	}
	}

	// GetValueForOS returns the label_list attribute value for an OS target.
	func (attrs *LabelListAttribute) GetValueForOS(os string) LabelList {
	var v *LabelList
	if v = attrs.osValuePtrs()[os]; v == nil {
	panic(fmt.Errorf("Unknown os: %s", os))
	}
	return *v
	}

	// SetValueForArch sets the label_list attribute value for an OS target.
	func (attrs *LabelListAttribute) SetValueForOS(os string, value LabelList) {
	var v *LabelList
	if v = attrs.osValuePtrs()[os]; v == nil {
	panic(fmt.Errorf("Unknown os: %s", os))
	}
	*v = value
	}

	// StringListAttribute corresponds to the string_list Bazel attribute type with
	// support for additional metadata, like configurations.
	type StringListAttribute struct {
	// The base value of the string list attribute.
	Value []string

	// The arch-specific attribute string list values. Optional. If used, these
	// are generated in a select statement and appended to the non-arch specific
	// label list Value.
	ArchValues stringListArchValues

	// The os-specific attribute string list values. Optional. If used, these
	// are generated in a select statement and appended to the non-os specific
	// label list Value.
	OsValues stringListOsValues
	}

	// MakeStringListAttribute initializes a StringListAttribute with the non-arch specific value.
	func MakeStringListAttribute(value []string) StringListAttribute {
	// NOTE: These strings are not necessarily unique or sorted.
	return StringListAttribute{Value: value}
	}

	// Arch-specific string_list typed Bazel attribute values. This should correspond
	// to the types of architectures supported for compilation in arch.go.
	type stringListArchValues struct {
	X86 []string
	X86_64 []string
	Arm []string
	Arm64 []string
	Common []string

	ConditionsDefault []string
	}

	type stringListOsValues struct {
	Android []string
	Darwin []string
	Fuchsia []string
	Linux []string
	LinuxBionic []string
	Windows []string

	ConditionsDefault []string
	}

	// HasConfigurableValues returns true if the attribute contains
	// architecture-specific string_list values.
	func (attrs StringListAttribute) HasConfigurableValues() bool {
	for arch := range PlatformArchMap {
	if len(attrs.GetValueForArch(arch)) > 0 {
	return true
	}
	}

	for os := range PlatformOsMap {
	if len(attrs.GetValueForOS(os)) > 0 {
	return true
	}
	}
	return false
	}

	func (attrs StringListAttribute) archValuePtrs() map[string][]string {
	return map[string]*[]string{
	ARCH_X86: &attrs.ArchValues.X86,
	ARCH_X86_64: &attrs.ArchValues.X86_64,
	ARCH_ARM: &attrs.ArchValues.Arm,
	ARCH_ARM64: &attrs.ArchValues.Arm64,
	CONDITIONS_DEFAULT: &attrs.ArchValues.ConditionsDefault,
	}
	}

	// GetValueForArch returns the string_list attribute value for an architecture.
	func (attrs *StringListAttribute) GetValueForArch(arch string) []string {
	var v *[]string
	if v = attrs.archValuePtrs()[arch]; v == nil {
	panic(fmt.Errorf("Unknown arch: %s", arch))
	}
	return *v
	}

	// SetValueForArch sets the string_list attribute value for an architecture.
	func (attrs *StringListAttribute) SetValueForArch(arch string, value []string) {
	var v *[]string
	if v = attrs.archValuePtrs()[arch]; v == nil {
	panic(fmt.Errorf("Unknown arch: %s", arch))
	}
	*v = value
	}

	func (attrs StringListAttribute) osValuePtrs() map[string][]string {
	return map[string]*[]string{
	OS_ANDROID: &attrs.OsValues.Android,
	OS_DARWIN: &attrs.OsValues.Darwin,
	OS_FUCHSIA: &attrs.OsValues.Fuchsia,
	OS_LINUX: &attrs.OsValues.Linux,
	OS_LINUX_BIONIC: &attrs.OsValues.LinuxBionic,
	OS_WINDOWS: &attrs.OsValues.Windows,
	CONDITIONS_DEFAULT: &attrs.OsValues.ConditionsDefault,
	}
	}

	// GetValueForOS returns the string_list attribute value for an OS target.
	func (attrs *StringListAttribute) GetValueForOS(os string) []string {
	var v *[]string
	if v = attrs.osValuePtrs()[os]; v == nil {
	panic(fmt.Errorf("Unknown os: %s", os))
	}
	return *v
	}

	// SetValueForArch sets the string_list attribute value for an OS target.
	func (attrs *StringListAttribute) SetValueForOS(os string, value []string) {
	var v *[]string
	if v = attrs.osValuePtrs()[os]; v == nil {
	panic(fmt.Errorf("Unknown os: %s", os))
	}
	*v = value
	}

	// Append appends all values, including os and arch specific ones, from another
	// StringListAttribute to this StringListAttribute
	func (attrs *StringListAttribute) Append(other StringListAttribute) {
	for arch := range PlatformArchMap {
	this := attrs.GetValueForArch(arch)
	that := other.GetValueForArch(arch)
	this = append(this, that...)
	attrs.SetValueForArch(arch, this)
	}

	for os := range PlatformOsMap {
	this := attrs.GetValueForOS(os)
	that := other.GetValueForOS(os)
	this = append(this, that...)
	attrs.SetValueForOS(os, this)
	}

	attrs.Value = append(attrs.Value, other.Value...)
	}

	// TryVariableSubstitution, replace string substitution formatting within each string in slice with
	// Starlark string.format compatible tag for productVariable.
	func TryVariableSubstitutions(slice []string, productVariable string) ([]string, bool) {
	ret := make([]string, 0, len(slice))
	changesMade := false
	for _, s := range slice {
	newS, changed := TryVariableSubstitution(s, productVariable)
	ret = append(ret, newS)
	changesMade = changesMade \|\| changed
	}
	return ret, changesMade
	}

	// TryVariableSubstitution, replace string substitution formatting within s with Starlark
	// string.format compatible tag for productVariable.
	func TryVariableSubstitution(s string, productVariable string) (string, bool) {
	sub := productVariableSubstitutionPattern.ReplaceAllString(s, "{"+productVariable+"}")
	return sub, s != sub
	}