Use generics for DepSets (c85750bf) · Commits · e / os / android_build_soong

aidl_library/aidl_library.go

+4 −4

Original line number	Diff line number	Diff line
		@@ -108,17 +108,17 @@ type AidlLibraryInfo struct {
		// The direct aidl files of the module
		Srcs android.Paths
		// The include dirs to the direct aidl files and those provided from transitive aidl_library deps
		IncludeDirs android.DepSet
		IncludeDirs android.DepSet[android.Path]
		// The direct hdrs and hdrs from transitive deps
		Hdrs android.DepSet
		Hdrs android.DepSet[android.Path]
		}

		// AidlLibraryProvider provides the srcs and the transitive include dirs
		var AidlLibraryProvider = blueprint.NewProvider(AidlLibraryInfo{})

		func (lib *AidlLibrary) GenerateAndroidBuildActions(ctx android.ModuleContext) {
		includeDirsDepSetBuilder := android.NewDepSetBuilder(android.PREORDER)
		hdrsDepSetBuilder := android.NewDepSetBuilder(android.PREORDER)
		includeDirsDepSetBuilder := android.NewDepSetBuilder[android.Path](android.PREORDER)
		hdrsDepSetBuilder := android.NewDepSetBuilder[android.Path](android.PREORDER)

		if len(lib.properties.Srcs) == 0 && len(lib.properties.Hdrs) == 0 {
		ctx.ModuleErrorf("at least srcs or hdrs prop must be non-empty")

aidl_library/aidl_library_test.go

+2 −2

Original line number	Diff line number	Diff line
		@@ -52,7 +52,7 @@ func TestAidlLibrary(t *testing.T) {
		t,
		"aidl include dirs",
		[]string{"package_foo/a", "package_bar/x"},
		actualInfo.IncludeDirs.ToList().Strings(),
		android.Paths(actualInfo.IncludeDirs.ToList()).Strings(),
		)

		android.AssertPathsRelativeToTopEquals(
		@@ -101,7 +101,7 @@ func TestAidlLibraryWithoutStripImportPrefix(t *testing.T) {
		t,
		"aidl include dirs",
		[]string{"package_foo", "package_bar"},
		actualInfo.IncludeDirs.ToList().Strings(),
		android.Paths(actualInfo.IncludeDirs.ToList()).Strings(),
		)

		android.AssertPathsRelativeToTopEquals(

android/Android.bp

+0 −1

Original line number	Diff line number	Diff line
		@@ -48,7 +48,6 @@ bootstrap_go_package {
		"defaults.go",
		"defs.go",
		"depset_generic.go",
		"depset_paths.go",
		"deptag.go",
		"expand.go",
		"filegroup.go",

android/depset_generic.go

+75 −226

Original line number	Diff line number	Diff line
		@@ -16,10 +16,9 @@ package android

		import (
		"fmt"
		"reflect"
		)

		// depSet is designed to be conceptually compatible with Bazel's depsets:
		// DepSet is designed to be conceptually compatible with Bazel's depsets:
		// https://docs.bazel.build/versions/master/skylark/depsets.html

		type DepSetOrder int
		@@ -43,142 +42,114 @@ func (o DepSetOrder) String() string {
		}
		}

		// A depSet efficiently stores a slice of an arbitrary type from transitive dependencies without
		// copying. It is stored as a DAG of depSet nodes, each of which has some direct contents and a list
		// of dependency depSet nodes.
		type depSettableType comparable

		// A DepSet efficiently stores a slice of an arbitrary type from transitive dependencies without
		// copying. It is stored as a DAG of DepSet nodes, each of which has some direct contents and a list
		// of dependency DepSet nodes.
		//
		// A depSet has an order that will be used to walk the DAG when ToList() is called. The order
		// A DepSet has an order that will be used to walk the DAG when ToList() is called. The order
		// can be POSTORDER, PREORDER, or TOPOLOGICAL. POSTORDER and PREORDER orders return a postordered
		// or preordered left to right flattened list. TOPOLOGICAL returns a list that guarantees that
		// elements of children are listed after all of their parents (unless there are duplicate direct
		// elements in the depSet or any of its transitive dependencies, in which case the ordering of the
		// elements in the DepSet or any of its transitive dependencies, in which case the ordering of the
		// duplicated element is not guaranteed).
		//
		// A depSet is created by newDepSet or newDepSetBuilder.Build from the slice for direct contents
		// and the *depSets of dependencies. A depSet is immutable once created.
		//
		// This object uses reflection to remain agnostic to the type it contains. It should be replaced
		// with generics once those exist in Go. Callers should generally use a thin wrapper around depSet
		// that provides type-safe methods like DepSet for Paths.
		type depSet struct {
		// A DepSet is created by NewDepSet or NewDepSetBuilder.Build from the slice for direct contents
		// and the *DepSets of dependencies. A DepSet is immutable once created.
		type DepSet[T depSettableType] struct {
		preorder bool
		reverse bool
		order DepSetOrder
		direct interface{}
		transitive []*depSet
		direct []T
		transitive []*DepSet[T]
		}

		type depSetInterface interface {
		embeddedDepSet() *depSet
		// NewDepSet returns an immutable DepSet with the given order, direct and transitive contents.
		func NewDepSet[T depSettableType](order DepSetOrder, direct []T, transitive []DepSet[T]) DepSet[T] {
		var directCopy []T
		var transitiveCopy []*DepSet[T]
		for _, t := range transitive {
		if t.order != order {
		panic(fmt.Errorf("incompatible order, new DepSet is %s but transitive DepSet is %s",
		order, t.order))
		}

		func (d depSet) embeddedDepSet() depSet {
		return d
		}

		var _ depSetInterface = (*depSet)(nil)

		// newDepSet returns an immutable depSet with the given order, direct and transitive contents.
		// direct must be a slice, but is not type-safe due to the lack of generics in Go. It can be a
		// nil slice, but not a nil interface{}, i.e. []string(nil) but not nil.
		func newDepSet(order DepSetOrder, direct interface{}, transitive interface{}) *depSet {
		var directCopy interface{}
		transitiveDepSet := sliceToDepSets(transitive, order)

		if order == TOPOLOGICAL {
		// TOPOLOGICAL is implemented as a postorder traversal followed by reversing the output.
		// Pre-reverse the inputs here so their order is maintained in the output.
		directCopy = reverseSlice(direct)
		reverseSliceInPlace(transitiveDepSet)
		transitiveCopy = reverseSlice(transitive)
		} else {
		directCopy = copySlice(direct)
		directCopy = append([]T(nil), direct...)
		transitiveCopy = append([]*DepSet[T](nil), transitive...)
		}

		return &depSet{
		return &DepSet[T]{
		preorder: order == PREORDER,
		reverse: order == TOPOLOGICAL,
		order: order,
		direct: directCopy,
		transitive: transitiveDepSet,
		transitive: transitiveCopy,
		}
		}

		// depSetBuilder is used to create an immutable depSet.
		type depSetBuilder struct {
		// DepSetBuilder is used to create an immutable DepSet.
		type DepSetBuilder[T depSettableType] struct {
		order DepSetOrder
		direct reflect.Value
		transitive []*depSet
		direct []T
		transitive []*DepSet[T]
		}

		// newDepSetBuilder returns a depSetBuilder to create an immutable depSet with the given order and
		// type, represented by a slice of type that will be in the depSet.
		func newDepSetBuilder(order DepSetOrder, typ interface{}) *depSetBuilder {
		empty := reflect.Zero(reflect.TypeOf(typ))
		return &depSetBuilder{
		// NewDepSetBuilder returns a DepSetBuilder to create an immutable DepSet with the given order and
		// type, represented by a slice of type that will be in the DepSet.
		func NewDepSetBuilder[T depSettableType](order DepSetOrder) *DepSetBuilder[T] {
		return &DepSetBuilder[T]{
		order: order,
		direct: empty,
		}
		}

		// sliceToDepSets converts a slice of any type that implements depSetInterface (by having a depSet
		// embedded in it) into a []*depSet.
		func sliceToDepSets(in interface{}, order DepSetOrder) []*depSet {
		slice := reflect.ValueOf(in)
		length := slice.Len()
		out := make([]*depSet, length)
		for i := 0; i < length; i++ {
		vi := slice.Index(i)
		depSetIntf, ok := vi.Interface().(depSetInterface)
		if !ok {
		panic(fmt.Errorf("element %d is a %s, not a depSetInterface", i, vi.Type()))
		}
		depSet := depSetIntf.embeddedDepSet()
		if depSet.order != order {
		panic(fmt.Errorf("incompatible order, new depSet is %s but transitive depSet is %s",
		order, depSet.order))
		}
		out[i] = depSet
		}
		return out
		}

		// DirectSlice adds direct contents to the depSet being built by a depSetBuilder. Newly added direct
		// contents are to the right of any existing direct contents. The argument must be a slice, but
		// is not type-safe due to the lack of generics in Go.
		func (b depSetBuilder) DirectSlice(direct interface{}) depSetBuilder {
		b.direct = reflect.AppendSlice(b.direct, reflect.ValueOf(direct))
		// DirectSlice adds direct contents to the DepSet being built by a DepSetBuilder. Newly added direct
		// contents are to the right of any existing direct contents.
		func (b DepSetBuilder[T]) DirectSlice(direct []T) DepSetBuilder[T] {
		b.direct = append(b.direct, direct...)
		return b
		}

		// Direct adds direct contents to the depSet being built by a depSetBuilder. Newly added direct
		// contents are to the right of any existing direct contents. The argument must be the same type
		// as the element of the slice passed to newDepSetBuilder, but is not type-safe due to the lack of
		// generics in Go.
		func (b depSetBuilder) Direct(direct interface{}) depSetBuilder {
		b.direct = reflect.Append(b.direct, reflect.ValueOf(direct))
		// Direct adds direct contents to the DepSet being built by a DepSetBuilder. Newly added direct
		// contents are to the right of any existing direct contents.
		func (b DepSetBuilder[T]) Direct(direct ...T) DepSetBuilder[T] {
		b.direct = append(b.direct, direct...)
		return b
		}

		// Transitive adds transitive contents to the DepSet being built by a DepSetBuilder. Newly added
		// transitive contents are to the right of any existing transitive contents. The argument can
		// be any slice of type that has depSet embedded in it.
		func (b depSetBuilder) Transitive(transitive interface{}) depSetBuilder {
		depSets := sliceToDepSets(transitive, b.order)
		b.transitive = append(b.transitive, depSets...)
		// transitive contents are to the right of any existing transitive contents.
		func (b DepSetBuilder[T]) Transitive(transitive ...DepSet[T]) *DepSetBuilder[T] {
		for _, t := range transitive {
		if t.order != b.order {
		panic(fmt.Errorf("incompatible order, new DepSet is %s but transitive DepSet is %s",
		b.order, t.order))
		}
		}
		b.transitive = append(b.transitive, transitive...)
		return b
		}

		// Returns the depSet being built by this depSetBuilder. The depSetBuilder retains its contents
		// Returns the DepSet being built by this DepSetBuilder. The DepSetBuilder retains its contents
		// for creating more depSets.
		func (b depSetBuilder) Build() depSet {
		return newDepSet(b.order, b.direct.Interface(), b.transitive)
		func (b DepSetBuilder[T]) Build() DepSet[T] {
		return NewDepSet(b.order, b.direct, b.transitive)
		}

		// walk calls the visit method in depth-first order on a DepSet, preordered if d.preorder is set,
		// otherwise postordered.
		func (d *depSet) walk(visit func(interface{})) {
		visited := make(map[*depSet]bool)
		func (d *DepSet[T]) walk(visit func([]T)) {
		visited := make(map[*DepSet[T]]bool)

		var dfs func(d *depSet)
		dfs = func(d *depSet) {
		var dfs func(d *DepSet[T])
		dfs = func(d *DepSet[T]) {
		visited[d] = true
		if d.preorder {
		visit(d.direct)
		@@ -197,155 +168,33 @@ func (d *depSet) walk(visit func(interface{})) {
		dfs(d)
		}

		// ToList returns the depSet flattened to a list. The order in the list is based on the order
		// of the depSet. POSTORDER and PREORDER orders return a postordered or preordered left to right
		// ToList returns the DepSet flattened to a list. The order in the list is based on the order
		// of the DepSet. POSTORDER and PREORDER orders return a postordered or preordered left to right
		// flattened list. TOPOLOGICAL returns a list that guarantees that elements of children are listed
		// after all of their parents (unless there are duplicate direct elements in the DepSet or any of
		// its transitive dependencies, in which case the ordering of the duplicated element is not
		// guaranteed).
		//
		// This method uses a reflection-based implementation to find the unique elements in slice, which
		// is around 3x slower than a concrete implementation. Type-safe wrappers around depSet can
		// provide their own implementation of ToList that calls depSet.toList with a method that
		// uses a concrete implementation.
		func (d *depSet) ToList() interface{} {
		return d.toList(firstUnique)
		func (d *DepSet[T]) ToList() []T {
		return d.toList(firstUnique[T])
		}

		// toList returns the depSet flattened to a list. The order in the list is based on the order
		// of the depSet. POSTORDER and PREORDER orders return a postordered or preordered left to right
		// toList returns the DepSet flattened to a list. The order in the list is based on the order
		// of the DepSet. POSTORDER and PREORDER orders return a postordered or preordered left to right
		// flattened list. TOPOLOGICAL returns a list that guarantees that elements of children are listed
		// after all of their parents (unless there are duplicate direct elements in the DepSet or any of
		// its transitive dependencies, in which case the ordering of the duplicated element is not
		// guaranteed). The firstUniqueFunc is used to remove duplicates from the list.
		func (d *depSet) toList(firstUniqueFunc func(interface{}) interface{}) interface{} {
		func (d *DepSet[T]) toList(firstUniqueFunc func([]T) []T) []T {
		if d == nil {
		return nil
		}
		slice := reflect.Zero(reflect.TypeOf(d.direct))
		d.walk(func(paths interface{}) {
		slice = reflect.AppendSlice(slice, reflect.ValueOf(paths))
		var list []T
		d.walk(func(paths []T) {
		list = append(list, paths...)
		})
		list := slice.Interface()
		list = firstUniqueFunc(list)
		if d.reverse {
		reverseSliceInPlace(list)
		}
		return list
		}

		// firstUnique returns all unique elements of a slice, keeping the first copy of each. It
		// modifies the slice contents in place, and returns a subslice of the original slice. The
		// argument must be a slice, but is not type-safe due to the lack of reflection in Go.
		//
		// Performance of the reflection-based firstUnique is up to 3x slower than a concrete type
		// version such as FirstUniqueStrings.
		func firstUnique(slice interface{}) interface{} {
		// 4 was chosen based on Benchmark_firstUnique results.
		if reflect.ValueOf(slice).Len() > 4 {
		return firstUniqueMap(slice)
		}
		return firstUniqueList(slice)
		}

		// firstUniqueList is an implementation of firstUnique using an O(N^2) list comparison to look for
		// duplicates.
		func firstUniqueList(in interface{}) interface{} {
		writeIndex := 0
		slice := reflect.ValueOf(in)
		length := slice.Len()
		outer:
		for readIndex := 0; readIndex < length; readIndex++ {
		readValue := slice.Index(readIndex)
		for compareIndex := 0; compareIndex < writeIndex; compareIndex++ {
		compareValue := slice.Index(compareIndex)
		// These two Interface() calls seem to cause an allocation and significantly
		// slow down this list-based implementation. The map implementation below doesn't
		// have this issue because reflect.Value.MapIndex takes a Value and appears to be
		// able to do the map lookup without an allocation.
		if readValue.Interface() == compareValue.Interface() {
		// The value at readIndex already exists somewhere in the output region
		// of the slice before writeIndex, skip it.
		continue outer
		}
		}
		if readIndex != writeIndex {
		writeValue := slice.Index(writeIndex)
		writeValue.Set(readValue)
		}
		writeIndex++
		}
		return slice.Slice(0, writeIndex).Interface()
		}

		var trueValue = reflect.ValueOf(true)

		// firstUniqueList is an implementation of firstUnique using an O(N) hash set lookup to look for
		// duplicates.
		func firstUniqueMap(in interface{}) interface{} {
		writeIndex := 0
		slice := reflect.ValueOf(in)
		length := slice.Len()
		seen := reflect.MakeMapWithSize(reflect.MapOf(slice.Type().Elem(), trueValue.Type()), slice.Len())
		for readIndex := 0; readIndex < length; readIndex++ {
		readValue := slice.Index(readIndex)
		if seen.MapIndex(readValue).IsValid() {
		continue
		}
		seen.SetMapIndex(readValue, trueValue)
		if readIndex != writeIndex {
		writeValue := slice.Index(writeIndex)
		writeValue.Set(readValue)
		}
		writeIndex++
		}
		return slice.Slice(0, writeIndex).Interface()
		}

		// reverseSliceInPlace reverses the elements of a slice in place. The argument must be a slice, but
		// is not type-safe due to the lack of reflection in Go.
		func reverseSliceInPlace(in interface{}) {
		swapper := reflect.Swapper(in)
		slice := reflect.ValueOf(in)
		length := slice.Len()
		for i, j := 0, length-1; i < j; i, j = i+1, j-1 {
		swapper(i, j)
		}
		}

		// reverseSlice returns a copy of a slice in reverse order. The argument must be a slice, but is
		// not type-safe due to the lack of reflection in Go.
		func reverseSlice(in interface{}) interface{} {
		slice := reflect.ValueOf(in)
		if !slice.IsValid() \|\| slice.IsNil() {
		return in
		}
		if slice.Kind() != reflect.Slice {
		panic(fmt.Errorf("%t is not a slice", in))
		}
		length := slice.Len()
		if length == 0 {
		return in
		}
		out := reflect.MakeSlice(slice.Type(), length, length)
		for i := 0; i < length; i++ {
		out.Index(i).Set(slice.Index(length - 1 - i))
		}
		return out.Interface()
		}

		// copySlice returns a copy of a slice. The argument must be a slice, but is not type-safe due to
		// the lack of reflection in Go.
		func copySlice(in interface{}) interface{} {
		slice := reflect.ValueOf(in)
		if !slice.IsValid() \|\| slice.IsNil() {
		return in
		}
		length := slice.Len()
		if length == 0 {
		return in
		}
		out := reflect.MakeSlice(slice.Type(), length, length)
		reflect.Copy(out, slice)
		return out.Interface()
		}

android/depset_paths.go

deleted100644 → 0

+0 −94

Original line number	Diff line number	Diff line
		// 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 android

		// This file implements DepSet, a thin type-safe wrapper around depSet that contains Paths.

		// A DepSet efficiently stores Paths from transitive dependencies without copying. It is stored
		// as a DAG of DepSet nodes, each of which has some direct contents and a list of dependency
		// DepSet nodes.
		//
		// A DepSet has an order that will be used to walk the DAG when ToList() is called. The order
		// can be POSTORDER, PREORDER, or TOPOLOGICAL. POSTORDER and PREORDER orders return a postordered
		// or preordered left to right flattened list. TOPOLOGICAL returns a list that guarantees that
		// elements of children are listed after all of their parents (unless there are duplicate direct
		// elements in the DepSet or any of its transitive dependencies, in which case the ordering of the
		// duplicated element is not guaranteed).
		//
		// A DepSet is created by NewDepSet or NewDepSetBuilder.Build from the Paths for direct contents
		// and the *DepSets of dependencies. A DepSet is immutable once created.
		type DepSet struct {
		depSet
		}

		// DepSetBuilder is used to create an immutable DepSet.
		type DepSetBuilder struct {
		depSetBuilder
		}

		// NewDepSet returns an immutable DepSet with the given order, direct and transitive contents.
		func NewDepSet(order DepSetOrder, direct Paths, transitive []DepSet) DepSet {
		return &DepSet{*newDepSet(order, direct, transitive)}
		}

		// NewDepSetBuilder returns a DepSetBuilder to create an immutable DepSet with the given order.
		func NewDepSetBuilder(order DepSetOrder) *DepSetBuilder {
		return &DepSetBuilder{*newDepSetBuilder(order, Paths(nil))}
		}

		// Direct adds direct contents to the DepSet being built by a DepSetBuilder. Newly added direct
		// contents are to the right of any existing direct contents.
		func (b DepSetBuilder) Direct(direct ...Path) DepSetBuilder {
		b.depSetBuilder.DirectSlice(direct)
		return b
		}

		// Transitive adds transitive contents to the DepSet being built by a DepSetBuilder. Newly added
		// transitive contents are to the right of any existing transitive contents.
		func (b DepSetBuilder) Transitive(transitive ...DepSet) *DepSetBuilder {
		b.depSetBuilder.Transitive(transitive)
		return b
		}

		// Returns the DepSet being built by this DepSetBuilder. The DepSetBuilder retains its contents
		// for creating more DepSets.
		func (b DepSetBuilder) Build() DepSet {
		return &DepSet{*b.depSetBuilder.Build()}
		}

		// ToList returns the DepSet flattened to a list. The order in the list is based on the order
		// of the DepSet. POSTORDER and PREORDER orders return a postordered or preordered left to right
		// flattened list. TOPOLOGICAL returns a list that guarantees that elements of children are listed
		// after all of their parents (unless there are duplicate direct elements in the DepSet or any of
		// its transitive dependencies, in which case the ordering of the duplicated element is not
		// guaranteed).
		func (d *DepSet) ToList() Paths {
		if d == nil {
		return nil
		}
		return d.toList(func(paths interface{}) interface{} {
		return FirstUniquePaths(paths.(Paths))
		}).(Paths)
		}

		// ToSortedList returns the direct and transitive contents of a DepSet in lexically sorted order
		// with duplicates removed.
		func (d *DepSet) ToSortedList() Paths {
		if d == nil {
		return nil
		}
		paths := d.ToList()
		return SortedUniquePaths(paths)
		}