diff --git a/android/Android.bp b/android/Android.bp
index 4bd272d..f8c1d55 100644
--- a/android/Android.bp
+++ b/android/Android.bp
@@ -23,7 +23,8 @@
         "csuite_config.go",
         "defaults.go",
         "defs.go",
-        "depset.go",
+        "depset_generic.go",
+        "depset_paths.go",
         "deptag.go",
         "expand.go",
         "filegroup.go",
diff --git a/android/androidmk.go b/android/androidmk.go
index 42c5d00..b32048a 100644
--- a/android/androidmk.go
+++ b/android/androidmk.go
@@ -141,7 +141,7 @@
 }
 
 type AndroidMkExtraEntriesFunc func(entries *AndroidMkEntries)
-type AndroidMkExtraFootersFunc func(w io.Writer, name, prefix, moduleDir string, entries *AndroidMkEntries)
+type AndroidMkExtraFootersFunc func(w io.Writer, name, prefix, moduleDir string)
 
 // Utility funcs to manipulate Android.mk variable entries.
 
@@ -554,7 +554,7 @@
 	fmt.Fprintln(&a.footer, "include "+a.Include)
 	blueprintDir := filepath.Dir(bpPath)
 	for _, footerFunc := range a.ExtraFooters {
-		footerFunc(&a.footer, name, prefix, blueprintDir, a)
+		footerFunc(&a.footer, name, prefix, blueprintDir)
 	}
 }
 
diff --git a/android/apex.go b/android/apex.go
index a4ff0f9..4a71b40 100644
--- a/android/apex.go
+++ b/android/apex.go
@@ -257,7 +257,7 @@
 	canHaveApexVariants bool
 
 	apexInfos     []ApexInfo
-	apexInfosLock sync.Mutex // protects apexInfos during parallel apexDepsMutator
+	apexInfosLock sync.Mutex // protects apexInfos during parallel apexInfoMutator
 }
 
 // Initializes ApexModuleBase struct. Not calling this (even when inheriting from ApexModuleBase)
@@ -442,7 +442,7 @@
 	} else {
 		apexInfos = base.apexInfos
 	}
-	// base.apexInfos is only needed to propagate the list of apexes from apexDepsMutator to
+	// base.apexInfos is only needed to propagate the list of apexes from apexInfoMutator to
 	// apexMutator. It is no longer accurate after mergeApexVariations, and won't be copied to
 	// all but the first created variant. Clear it so it doesn't accidentally get used later.
 	base.apexInfos = nil
diff --git a/android/config.go b/android/config.go
index 9882d55..453e074 100644
--- a/android/config.go
+++ b/android/config.go
@@ -1272,6 +1272,10 @@
 	return Bool(c.productVariables.Flatten_apex)
 }
 
+func (c *config) CompressedApex() bool {
+	return Bool(c.productVariables.CompressedApex)
+}
+
 func (c *config) EnforceSystemCertificate() bool {
 	return Bool(c.productVariables.EnforceSystemCertificate)
 }
diff --git a/android/depset.go b/android/depset.go
deleted file mode 100644
index 60ebcac..0000000
--- a/android/depset.go
+++ /dev/null
@@ -1,194 +0,0 @@
-// 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
-
-import "fmt"
-
-// DepSet is designed to be conceptually compatible with Bazel's depsets:
-// https://docs.bazel.build/versions/master/skylark/depsets.html
-
-// 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 {
-	preorder   bool
-	reverse    bool
-	order      DepSetOrder
-	direct     Paths
-	transitive []*DepSet
-}
-
-// DepSetBuilder is used to create an immutable DepSet.
-type DepSetBuilder struct {
-	order      DepSetOrder
-	direct     Paths
-	transitive []*DepSet
-}
-
-type DepSetOrder int
-
-const (
-	PREORDER DepSetOrder = iota
-	POSTORDER
-	TOPOLOGICAL
-)
-
-func (o DepSetOrder) String() string {
-	switch o {
-	case PREORDER:
-		return "PREORDER"
-	case POSTORDER:
-		return "POSTORDER"
-	case TOPOLOGICAL:
-		return "TOPOLOGICAL"
-	default:
-		panic(fmt.Errorf("Invalid DepSetOrder %d", o))
-	}
-}
-
-// NewDepSet returns an immutable DepSet with the given order, direct and transitive contents.
-func NewDepSet(order DepSetOrder, direct Paths, transitive []*DepSet) *DepSet {
-	var directCopy Paths
-	transitiveCopy := make([]*DepSet, 0, len(transitive))
-
-	for _, dep := range transitive {
-		if dep != nil {
-			if dep.order != order {
-				panic(fmt.Errorf("incompatible order, new DepSet is %s but transitive DepSet is %s",
-					order, dep.order))
-			}
-			transitiveCopy = append(transitiveCopy, dep)
-		}
-	}
-
-	if order == TOPOLOGICAL {
-		directCopy = ReversePaths(direct)
-		reverseDepSetsInPlace(transitiveCopy)
-	} else {
-		// Use copy instead of append(nil, ...) to make a slice that is exactly the size of the input
-		// slice.  The DepSet is immutable, there is no need for additional capacity.
-		directCopy = make(Paths, len(direct))
-		copy(directCopy, direct)
-	}
-
-	return &DepSet{
-		preorder:   order == PREORDER,
-		reverse:    order == TOPOLOGICAL,
-		order:      order,
-		direct:     directCopy,
-		transitive: transitiveCopy,
-	}
-}
-
-// NewDepSetBuilder returns a DepSetBuilder to create an immutable DepSet with the given order.
-func NewDepSetBuilder(order DepSetOrder) *DepSetBuilder {
-	return &DepSetBuilder{order: order}
-}
-
-// 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.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.
-func (b *DepSetBuilder) Transitive(transitive ...*DepSet) *DepSetBuilder {
-	b.transitive = append(b.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 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(Paths)) {
-	visited := make(map[*DepSet]bool)
-
-	var dfs func(d *DepSet)
-	dfs = func(d *DepSet) {
-		visited[d] = true
-		if d.preorder {
-			visit(d.direct)
-		}
-		for _, dep := range d.transitive {
-			if !visited[dep] {
-				dfs(dep)
-			}
-		}
-
-		if !d.preorder {
-			visit(d.direct)
-		}
-	}
-
-	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
-// 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
-	}
-	var list Paths
-	d.walk(func(paths Paths) {
-		list = append(list, paths...)
-	})
-	list = FirstUniquePaths(list)
-	if d.reverse {
-		reversePathsInPlace(list)
-	}
-	return list
-}
-
-// ToSortedList returns the direct and transitive contents of a DepSet in lexically sorted order
-// with duplicates removed.
-func (d *DepSet) ToSortedList() Paths {
-	list := d.ToList()
-	return SortedUniquePaths(list)
-}
-
-func reversePathsInPlace(list Paths) {
-	for i, j := 0, len(list)-1; i < j; i, j = i+1, j-1 {
-		list[i], list[j] = list[j], list[i]
-	}
-}
-
-func reverseDepSetsInPlace(list []*DepSet) {
-	for i, j := 0, len(list)-1; i < j; i, j = i+1, j-1 {
-		list[i], list[j] = list[j], list[i]
-	}
-
-}
diff --git a/android/depset_generic.go b/android/depset_generic.go
new file mode 100644
index 0000000..f00e462
--- /dev/null
+++ b/android/depset_generic.go
@@ -0,0 +1,351 @@
+// 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
+
+import (
+	"fmt"
+	"reflect"
+)
+
+// depSet is designed to be conceptually compatible with Bazel's depsets:
+// https://docs.bazel.build/versions/master/skylark/depsets.html
+
+type DepSetOrder int
+
+const (
+	PREORDER DepSetOrder = iota
+	POSTORDER
+	TOPOLOGICAL
+)
+
+func (o DepSetOrder) String() string {
+	switch o {
+	case PREORDER:
+		return "PREORDER"
+	case POSTORDER:
+		return "POSTORDER"
+	case TOPOLOGICAL:
+		return "TOPOLOGICAL"
+	default:
+		panic(fmt.Errorf("Invalid DepSetOrder %d", o))
+	}
+}
+
+// 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
+// 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 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 {
+	preorder   bool
+	reverse    bool
+	order      DepSetOrder
+	direct     interface{}
+	transitive []*depSet
+}
+
+type depSetInterface interface {
+	embeddedDepSet() *depSet
+}
+
+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 {
+		directCopy = reverseSlice(direct)
+		reverseSliceInPlace(transitiveDepSet)
+	} else {
+		directCopy = copySlice(direct)
+	}
+
+	return &depSet{
+		preorder:   order == PREORDER,
+		reverse:    order == TOPOLOGICAL,
+		order:      order,
+		direct:     directCopy,
+		transitive: transitiveDepSet,
+	}
+}
+
+// depSetBuilder is used to create an immutable depSet.
+type depSetBuilder struct {
+	order      DepSetOrder
+	direct     reflect.Value
+	transitive []*depSet
+}
+
+// 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{
+		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))
+	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))
+	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...)
+	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 newDepSet(b.order, b.direct.Interface(), 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)
+
+	var dfs func(d *depSet)
+	dfs = func(d *depSet) {
+		visited[d] = true
+		if d.preorder {
+			visit(d.direct)
+		}
+		for _, dep := range d.transitive {
+			if !visited[dep] {
+				dfs(dep)
+			}
+		}
+
+		if !d.preorder {
+			visit(d.direct)
+		}
+	}
+
+	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
+// 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)
+}
+
+// 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{} {
+	if d == nil {
+		return nil
+	}
+	slice := reflect.Zero(reflect.TypeOf(d.direct))
+	d.walk(func(paths interface{}) {
+		slice = reflect.AppendSlice(slice, reflect.ValueOf(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()
+}
diff --git a/android/depset_paths.go b/android/depset_paths.go
new file mode 100644
index 0000000..ed561ba
--- /dev/null
+++ b/android/depset_paths.go
@@ -0,0 +1,94 @@
+// 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)
+}
diff --git a/android/depset_test.go b/android/depset_test.go
index c328127..955ccb0 100644
--- a/android/depset_test.go
+++ b/android/depset_test.go
@@ -17,6 +17,7 @@
 import (
 	"fmt"
 	"reflect"
+	"strconv"
 	"strings"
 	"testing"
 )
@@ -108,6 +109,7 @@
 			name: "builderReuse",
 			depSet: func(t *testing.T, order DepSetOrder) *DepSet {
 				assertEquals := func(t *testing.T, w, g Paths) {
+					t.Helper()
 					if !reflect.DeepEqual(w, g) {
 						t.Errorf("want %q, got %q", w, g)
 					}
@@ -302,3 +304,87 @@
 		})
 	}
 }
+
+func Test_firstUnique(t *testing.T) {
+	f := func(t *testing.T, imp func([]string) []string, in, want []string) {
+		t.Helper()
+		out := imp(in)
+		if !reflect.DeepEqual(out, want) {
+			t.Errorf("incorrect output:")
+			t.Errorf("     input: %#v", in)
+			t.Errorf("  expected: %#v", want)
+			t.Errorf("       got: %#v", out)
+		}
+	}
+
+	for _, testCase := range firstUniqueStringsTestCases {
+		t.Run("list", func(t *testing.T) {
+			f(t, func(s []string) []string {
+				return firstUniqueList(s).([]string)
+			}, testCase.in, testCase.out)
+		})
+		t.Run("map", func(t *testing.T) {
+			f(t, func(s []string) []string {
+				return firstUniqueMap(s).([]string)
+			}, testCase.in, testCase.out)
+		})
+	}
+}
+
+func Benchmark_firstUnique(b *testing.B) {
+	implementations := []struct {
+		name string
+		f    func([]string) []string
+	}{
+		{
+			name: "list",
+			f: func(slice []string) []string {
+				return firstUniqueList(slice).([]string)
+			},
+		},
+		{
+			name: "map",
+			f: func(slice []string) []string {
+				return firstUniqueMap(slice).([]string)
+			},
+		},
+		{
+			name: "optimal",
+			f: func(slice []string) []string {
+				return firstUnique(slice).([]string)
+			},
+		},
+	}
+	const maxSize = 1024
+	uniqueStrings := make([]string, maxSize)
+	for i := range uniqueStrings {
+		uniqueStrings[i] = strconv.Itoa(i)
+	}
+	sameString := make([]string, maxSize)
+	for i := range sameString {
+		sameString[i] = uniqueStrings[0]
+	}
+
+	f := func(b *testing.B, imp func([]string) []string, s []string) {
+		for i := 0; i < b.N; i++ {
+			b.ReportAllocs()
+			s = append([]string(nil), s...)
+			imp(s)
+		}
+	}
+
+	for n := 1; n <= maxSize; n <<= 1 {
+		b.Run(strconv.Itoa(n), func(b *testing.B) {
+			for _, implementation := range implementations {
+				b.Run(implementation.name, func(b *testing.B) {
+					b.Run("same", func(b *testing.B) {
+						f(b, implementation.f, sameString[:n])
+					})
+					b.Run("unique", func(b *testing.B) {
+						f(b, implementation.f, uniqueStrings[:n])
+					})
+				})
+			}
+		})
+	}
+}
diff --git a/android/makefile_goal.go b/android/makefile_goal.go
index b5d9d69..07354a6 100644
--- a/android/makefile_goal.go
+++ b/android/makefile_goal.go
@@ -80,7 +80,7 @@
 		Class:      "ETC",
 		OutputFile: OptionalPathForPath(p.outputFilePath),
 		ExtraFooters: []AndroidMkExtraFootersFunc{
-			func(w io.Writer, name, prefix, moduleDir string, entries *AndroidMkEntries) {
+			func(w io.Writer, name, prefix, moduleDir string) {
 				// Can't use Cp because inputPath() is not a valid Path.
 				fmt.Fprintf(w, "$(eval $(call copy-one-file,%s,%s))\n", proptools.String(p.inputPath()), p.outputFilePath)
 			},
diff --git a/android/module.go b/android/module.go
index b6729c0..bbdeb27 100644
--- a/android/module.go
+++ b/android/module.go
@@ -441,6 +441,10 @@
 
 	FilesToInstall() InstallPaths
 	PackagingSpecs() []PackagingSpec
+
+	// TransitivePackagingSpecs returns the PackagingSpecs for this module and any transitive
+	// dependencies with dependency tags for which IsInstallDepNeeded() returns true.
+	TransitivePackagingSpecs() []PackagingSpec
 }
 
 // Qualified id for a module
@@ -1003,12 +1007,14 @@
 	// The primary visibility property, may be nil, that controls access to the module.
 	primaryVisibilityProperty visibilityProperty
 
-	noAddressSanitizer bool
-	installFiles       InstallPaths
-	checkbuildFiles    Paths
-	packagingSpecs     []PackagingSpec
-	noticeFiles        Paths
-	phonies            map[string]Paths
+	noAddressSanitizer   bool
+	installFiles         InstallPaths
+	installFilesDepSet   *installPathsDepSet
+	checkbuildFiles      Paths
+	packagingSpecs       []PackagingSpec
+	packagingSpecsDepSet *packagingSpecsDepSet
+	noticeFiles          Paths
+	phonies              map[string]Paths
 
 	// The files to copy to the dist as explicitly specified in the .bp file.
 	distFiles TaggedDistFiles
@@ -1338,19 +1344,17 @@
 
 // computeInstallDeps finds the installed paths of all dependencies that have a dependency
 // tag that is annotated as needing installation via the IsInstallDepNeeded method.
-func (m *ModuleBase) computeInstallDeps(ctx blueprint.ModuleContext) InstallPaths {
-	var result InstallPaths
-	ctx.WalkDeps(func(child, parent blueprint.Module) bool {
-		if a, ok := child.(Module); ok {
-			if IsInstallDepNeeded(ctx.OtherModuleDependencyTag(child)) {
-				result = append(result, a.FilesToInstall()...)
-				return true
-			}
+func (m *ModuleBase) computeInstallDeps(ctx ModuleContext) ([]*installPathsDepSet, []*packagingSpecsDepSet) {
+	var installDeps []*installPathsDepSet
+	var packagingSpecs []*packagingSpecsDepSet
+	ctx.VisitDirectDeps(func(dep Module) {
+		if IsInstallDepNeeded(ctx.OtherModuleDependencyTag(dep)) {
+			installDeps = append(installDeps, dep.base().installFilesDepSet)
+			packagingSpecs = append(packagingSpecs, dep.base().packagingSpecsDepSet)
 		}
-		return false
 	})
 
-	return result
+	return installDeps, packagingSpecs
 }
 
 func (m *ModuleBase) FilesToInstall() InstallPaths {
@@ -1361,6 +1365,10 @@
 	return m.packagingSpecs
 }
 
+func (m *ModuleBase) TransitivePackagingSpecs() []PackagingSpec {
+	return m.packagingSpecsDepSet.ToList()
+}
+
 func (m *ModuleBase) NoAddressSanitizer() bool {
 	return m.noAddressSanitizer
 }
@@ -1587,11 +1595,15 @@
 		module:            m.module,
 		bp:                blueprintCtx,
 		baseModuleContext: m.baseModuleContextFactory(blueprintCtx),
-		installDeps:       m.computeInstallDeps(blueprintCtx),
-		installFiles:      m.installFiles,
 		variables:         make(map[string]string),
 	}
 
+	dependencyInstallFiles, dependencyPackagingSpecs := m.computeInstallDeps(ctx)
+	// set m.installFilesDepSet to only the transitive dependencies to be used as the dependencies
+	// of installed files of this module.  It will be replaced by a depset including the installed
+	// files of this module at the end for use by modules that depend on this one.
+	m.installFilesDepSet = newInstallPathsDepSet(nil, dependencyInstallFiles)
+
 	// Temporarily continue to call blueprintCtx.GetMissingDependencies() to maintain the previous behavior of never
 	// reporting missing dependency errors in Blueprint when AllowMissingDependencies == true.
 	// TODO: This will be removed once defaults modules handle missing dependency errors
@@ -1700,6 +1712,9 @@
 		}
 	}
 
+	m.installFilesDepSet = newInstallPathsDepSet(m.installFiles, dependencyInstallFiles)
+	m.packagingSpecsDepSet = newPackagingSpecsDepSet(m.packagingSpecs, dependencyPackagingSpecs)
+
 	m.buildParams = ctx.buildParams
 	m.ruleParams = ctx.ruleParams
 	m.variables = ctx.variables
@@ -1874,7 +1889,6 @@
 	bp blueprint.ModuleContext
 	baseModuleContext
 	packagingSpecs  []PackagingSpec
-	installDeps     InstallPaths
 	installFiles    InstallPaths
 	checkbuildFiles Paths
 	module          Module
@@ -2420,8 +2434,7 @@
 	m.module.base().hooks.runInstallHooks(m, srcPath, fullInstallPath, false)
 
 	if !m.skipInstall(fullInstallPath) {
-
-		deps = append(deps, m.installDeps.Paths()...)
+		deps = append(deps, m.module.base().installFilesDepSet.ToList().Paths()...)
 
 		var implicitDeps, orderOnlyDeps Paths
 
@@ -2858,3 +2871,23 @@
 	bpctx := ctx.blueprintBaseModuleContext()
 	return blueprint.CheckBlueprintSyntax(bpctx.ModuleFactories(), filename, contents)
 }
+
+// installPathsDepSet is a thin type-safe wrapper around the generic depSet.  It always uses
+// topological order.
+type installPathsDepSet struct {
+	depSet
+}
+
+// newInstallPathsDepSet returns an immutable packagingSpecsDepSet with the given direct and
+// transitive contents.
+func newInstallPathsDepSet(direct InstallPaths, transitive []*installPathsDepSet) *installPathsDepSet {
+	return &installPathsDepSet{*newDepSet(TOPOLOGICAL, direct, transitive)}
+}
+
+// ToList returns the installPathsDepSet flattened to a list in topological order.
+func (d *installPathsDepSet) ToList() InstallPaths {
+	if d == nil {
+		return nil
+	}
+	return d.depSet.ToList().(InstallPaths)
+}
diff --git a/android/mutator.go b/android/mutator.go
index 7a10477..31edea3 100644
--- a/android/mutator.go
+++ b/android/mutator.go
@@ -44,6 +44,11 @@
 	}
 }
 
+func registerMutatorsForBazelConversion(ctx *blueprint.Context) {
+	// FIXME(b/171263886): Start bringing in mutators to make the Bionic
+	// module subgraph suitable for automated conversion.
+}
+
 func registerMutators(ctx *blueprint.Context, preArch, preDeps, postDeps, finalDeps []RegisterMutatorFunc) {
 	mctx := &registerMutatorsContext{}
 
diff --git a/android/packaging.go b/android/packaging.go
index 09432e6..da745ff 100644
--- a/android/packaging.go
+++ b/android/packaging.go
@@ -203,3 +203,23 @@
 	builder.Build("zip_deps", fmt.Sprintf("Zipping deps for %s", ctx.ModuleName()))
 	return entries
 }
+
+// packagingSpecsDepSet is a thin type-safe wrapper around the generic depSet.  It always uses
+// topological order.
+type packagingSpecsDepSet struct {
+	depSet
+}
+
+// newPackagingSpecsDepSet returns an immutable packagingSpecsDepSet with the given direct and
+// transitive contents.
+func newPackagingSpecsDepSet(direct []PackagingSpec, transitive []*packagingSpecsDepSet) *packagingSpecsDepSet {
+	return &packagingSpecsDepSet{*newDepSet(TOPOLOGICAL, direct, transitive)}
+}
+
+// ToList returns the packagingSpecsDepSet flattened to a list in topological order.
+func (d *packagingSpecsDepSet) ToList() []PackagingSpec {
+	if d == nil {
+		return nil
+	}
+	return d.depSet.ToList().([]PackagingSpec)
+}
diff --git a/android/paths.go b/android/paths.go
index 5a41cf1..0238a3f 100644
--- a/android/paths.go
+++ b/android/paths.go
@@ -542,6 +542,45 @@
 	return list[:k]
 }
 
+// FirstUniqueInstallPaths returns all unique elements of an InstallPaths, keeping the first copy of each.  It
+// modifies the InstallPaths slice contents in place, and returns a subslice of the original slice.
+func FirstUniqueInstallPaths(list InstallPaths) InstallPaths {
+	// 128 was chosen based on BenchmarkFirstUniquePaths results.
+	if len(list) > 128 {
+		return firstUniqueInstallPathsMap(list)
+	}
+	return firstUniqueInstallPathsList(list)
+}
+
+func firstUniqueInstallPathsList(list InstallPaths) InstallPaths {
+	k := 0
+outer:
+	for i := 0; i < len(list); i++ {
+		for j := 0; j < k; j++ {
+			if list[i] == list[j] {
+				continue outer
+			}
+		}
+		list[k] = list[i]
+		k++
+	}
+	return list[:k]
+}
+
+func firstUniqueInstallPathsMap(list InstallPaths) InstallPaths {
+	k := 0
+	seen := make(map[InstallPath]bool, len(list))
+	for i := 0; i < len(list); i++ {
+		if seen[list[i]] {
+			continue
+		}
+		seen[list[i]] = true
+		list[k] = list[i]
+		k++
+	}
+	return list[:k]
+}
+
 // LastUniquePaths returns all unique elements of a Paths, keeping the last copy of each.  It
 // modifies the Paths slice contents in place, and returns a subslice of the original slice.
 func LastUniquePaths(list Paths) Paths {
diff --git a/android/prebuilt.go b/android/prebuilt.go
index 294a6e0..bb98ed4 100644
--- a/android/prebuilt.go
+++ b/android/prebuilt.go
@@ -178,6 +178,9 @@
 	srcPropertyName := proptools.PropertyNameForField(srcField)
 
 	srcsSupplier := func(ctx BaseModuleContext) []string {
+		if !module.Enabled() {
+			return nil
+		}
 		value := srcPropsValue.FieldByIndex(srcFieldIndex)
 		if value.Kind() == reflect.Ptr {
 			value = value.Elem()
diff --git a/android/queryview.go b/android/queryview.go
index 970ae01..1b7e77d 100644
--- a/android/queryview.go
+++ b/android/queryview.go
@@ -26,15 +26,40 @@
 // for calling the soong_build primary builder in the main build.ninja file.
 func init() {
 	RegisterSingletonType("bazel_queryview", BazelQueryViewSingleton)
+	RegisterSingletonType("bazel_converter", BazelConverterSingleton)
 }
 
+// BazelQueryViewSingleton is the singleton responsible for registering the
+// soong_build build statement that will convert the Soong module graph after
+// applying *all* mutators, enabing the feature to query the final state of the
+// Soong graph. This mode is meant for querying the build graph state, and not meant
+// for generating BUILD files to be checked in.
 func BazelQueryViewSingleton() Singleton {
 	return &bazelQueryViewSingleton{}
 }
 
-type bazelQueryViewSingleton struct{}
+// BazelConverterSingleton is the singleton responsible for registering the soong_build
+// build statement that will convert the Soong module graph by applying an alternate
+// pipeline of mutators, with the goal of reaching semantic equivalence between the original
+// Blueprint and final BUILD files. Using this mode, the goal is to be able to
+// build with these BUILD files directly in the source tree.
+func BazelConverterSingleton() Singleton {
+	return &bazelConverterSingleton{}
+}
 
-func (c *bazelQueryViewSingleton) GenerateBuildActions(ctx SingletonContext) {
+type bazelQueryViewSingleton struct{}
+type bazelConverterSingleton struct{}
+
+func generateBuildActionsForBazelConversion(ctx SingletonContext, converterMode bool) {
+	name := "queryview"
+	additionalEnvVars := ""
+	descriptionTemplate := "[EXPERIMENTAL, PRE-PRODUCTION] Creating the Bazel QueryView workspace with %s at $outDir"
+	if converterMode {
+		name = "bp2build"
+		additionalEnvVars = "CONVERT_TO_BAZEL=true"
+		descriptionTemplate = "[EXPERIMENTAL, PRE-PRODUCTION] Converting all Android.bp to Bazel BUILD files with %s at $outDir"
+	}
+
 	// Create a build and rule statement, using the Bazel QueryView's WORKSPACE
 	// file as the output file marker.
 	var deps Paths
@@ -42,22 +67,23 @@
 	deps = append(deps, moduleListFilePath)
 	deps = append(deps, pathForBuildToolDep(ctx, ctx.Config().ProductVariablesFileName))
 
-	bazelQueryViewDirectory := PathForOutput(ctx, "queryview")
+	bazelQueryViewDirectory := PathForOutput(ctx, name)
 	bazelQueryViewWorkspaceFile := bazelQueryViewDirectory.Join(ctx, "WORKSPACE")
 	primaryBuilder := primaryBuilderPath(ctx)
 	bazelQueryView := ctx.Rule(pctx, "bazelQueryView",
 		blueprint.RuleParams{
 			Command: fmt.Sprintf(
 				"rm -rf ${outDir}/* && "+
-					"%s --bazel_queryview_dir ${outDir} %s && "+
+					"%s %s --bazel_queryview_dir ${outDir} %s && "+
 					"echo WORKSPACE: `cat %s` > ${outDir}/.queryview-depfile.d",
+				additionalEnvVars,
 				primaryBuilder.String(),
 				strings.Join(os.Args[1:], " "),
 				moduleListFilePath.String(), // Use the contents of Android.bp.list as the depfile.
 			),
 			CommandDeps: []string{primaryBuilder.String()},
 			Description: fmt.Sprintf(
-				"[EXPERIMENTAL, PRE-PRODUCTION] Creating the Bazel QueryView workspace with %s at $outDir",
+				descriptionTemplate,
 				primaryBuilder.Base()),
 			Deps:    blueprint.DepsGCC,
 			Depfile: "${outDir}/.queryview-depfile.d",
@@ -73,6 +99,14 @@
 		},
 	})
 
-	// Add a phony target for building the Bazel QueryView
-	ctx.Phony("queryview", bazelQueryViewWorkspaceFile)
+	// Add a phony target for generating the workspace
+	ctx.Phony(name, bazelQueryViewWorkspaceFile)
+}
+
+func (c *bazelQueryViewSingleton) GenerateBuildActions(ctx SingletonContext) {
+	generateBuildActionsForBazelConversion(ctx, false)
+}
+
+func (c *bazelConverterSingleton) GenerateBuildActions(ctx SingletonContext) {
+	generateBuildActionsForBazelConversion(ctx, true)
 }
diff --git a/android/register.go b/android/register.go
index 08e47b3..b26f9b9 100644
--- a/android/register.go
+++ b/android/register.go
@@ -90,6 +90,21 @@
 	return ctx
 }
 
+// RegisterForBazelConversion registers an alternate shadow pipeline of
+// singletons, module types and mutators to register for converting Blueprint
+// files to semantically equivalent BUILD files.
+func (ctx *Context) RegisterForBazelConversion() {
+	for _, t := range moduleTypes {
+		ctx.RegisterModuleType(t.name, ModuleFactoryAdaptor(t.factory))
+	}
+
+	bazelConverterSingleton := singleton{"bp2build", BazelConverterSingleton}
+	ctx.RegisterSingletonType(bazelConverterSingleton.name,
+		SingletonFactoryAdaptor(ctx, bazelConverterSingleton.factory))
+
+	registerMutatorsForBazelConversion(ctx.Context)
+}
+
 func (ctx *Context) Register() {
 	for _, t := range preSingletons {
 		ctx.RegisterPreSingletonType(t.name, SingletonFactoryAdaptor(ctx, t.factory))
diff --git a/android/util_test.go b/android/util_test.go
index 25b52ca..fa26c77 100644
--- a/android/util_test.go
+++ b/android/util_test.go
@@ -593,6 +593,10 @@
 			name: "map",
 			f:    firstUniqueStringsMap,
 		},
+		{
+			name: "optimal",
+			f:    FirstUniqueStrings,
+		},
 	}
 	const maxSize = 1024
 	uniqueStrings := make([]string, maxSize)
diff --git a/android/variable.go b/android/variable.go
index 0df5272..aed145c 100644
--- a/android/variable.go
+++ b/android/variable.go
@@ -319,8 +319,9 @@
 	Ndk_abis               *bool `json:",omitempty"`
 	Exclude_draft_ndk_apis *bool `json:",omitempty"`
 
-	Flatten_apex *bool `json:",omitempty"`
-	Aml_abis     *bool `json:",omitempty"`
+	Flatten_apex   *bool `json:",omitempty"`
+	CompressedApex *bool `json:",omitempty"`
+	Aml_abis       *bool `json:",omitempty"`
 
 	DexpreoptGlobalConfig *string `json:",omitempty"`
 
diff --git a/androidmk/parser/make_strings.go b/androidmk/parser/make_strings.go
index 4b782a2..3c4815e 100644
--- a/androidmk/parser/make_strings.go
+++ b/androidmk/parser/make_strings.go
@@ -15,8 +15,10 @@
 package parser
 
 import (
+	"fmt"
 	"strings"
 	"unicode"
+	"unicode/utf8"
 )
 
 // A MakeString is a string that may contain variable substitutions in it.
@@ -130,8 +132,85 @@
 	})
 }
 
+// Words splits MakeString into multiple makeStrings separated by whitespace.
+// Thus, " a $(X)b  c " will be split into ["a", "$(X)b", "c"].
+// Splitting a MakeString consisting solely of whitespace yields empty array.
 func (ms *MakeString) Words() []*MakeString {
-	return ms.splitNFunc(-1, splitWords)
+	var ch rune    // current character
+	const EOF = -1 // no more characters
+	const EOS = -2 // at the end of a string chunk
+
+	// Next character's chunk and position
+	iString := 0
+	iChar := 0
+
+	var words []*MakeString
+	word := SimpleMakeString("", ms.Pos())
+
+	nextChar := func() {
+		if iString >= len(ms.Strings) {
+			ch = EOF
+		} else if iChar >= len(ms.Strings[iString]) {
+			iString++
+			iChar = 0
+			ch = EOS
+		} else {
+			var w int
+			ch, w = utf8.DecodeRuneInString(ms.Strings[iString][iChar:])
+			iChar += w
+		}
+	}
+
+	appendVariableAndAdvance := func() {
+		if iString-1 < len(ms.Variables) {
+			word.appendVariable(ms.Variables[iString-1])
+		}
+		nextChar()
+	}
+
+	appendCharAndAdvance := func(c rune) {
+		if c != EOF {
+			word.appendString(string(c))
+		}
+		nextChar()
+	}
+
+	nextChar()
+	for ch != EOF {
+		// Skip whitespace
+		for ch == ' ' || ch == '\t' {
+			nextChar()
+		}
+		if ch == EOS {
+			// "... $(X)... " case. The current word should be empty.
+			if !word.Empty() {
+				panic(fmt.Errorf("%q: EOS while current word %q is not empty, iString=%d",
+					ms.Dump(), word.Dump(), iString))
+			}
+			appendVariableAndAdvance()
+		}
+		// Copy word
+		for ch != EOF {
+			if ch == ' ' || ch == '\t' {
+				words = append(words, word)
+				word = SimpleMakeString("", ms.Pos())
+				break
+			}
+			if ch == EOS {
+				// "...a$(X)..." case. Append variable to the current word
+				appendVariableAndAdvance()
+			} else {
+				if ch == '\\' {
+					appendCharAndAdvance('\\')
+				}
+				appendCharAndAdvance(ch)
+			}
+		}
+	}
+	if !word.Empty() {
+		words = append(words, word)
+	}
+	return words
 }
 
 func (ms *MakeString) splitNFunc(n int, splitFunc func(s string, n int) []string) []*MakeString {
@@ -166,9 +245,7 @@
 		}
 	}
 
-	if !curMs.Empty() {
-		ret = append(ret, curMs)
-	}
+	ret = append(ret, curMs)
 	return ret
 }
 
@@ -219,44 +296,6 @@
 	return ret
 }
 
-func splitWords(s string, n int) []string {
-	ret := []string{}
-	preserve := ""
-	for n == -1 || n > 1 {
-		index := strings.IndexAny(s, " \t")
-		if index == 0 && len(preserve) == 0 {
-			s = s[1:]
-		} else if index >= 0 {
-			escapeCount := 0
-			for i := index - 1; i >= 0; i-- {
-				if s[i] != '\\' {
-					break
-				}
-				escapeCount += 1
-			}
-
-			if escapeCount%2 == 1 {
-				preserve += s[0 : index+1]
-				s = s[index+1:]
-				continue
-			}
-
-			ret = append(ret, preserve+s[0:index])
-			s = s[index+1:]
-			preserve = ""
-			if n > 0 {
-				n--
-			}
-		} else {
-			break
-		}
-	}
-	if preserve != "" || s != "" || len(ret) == 0 {
-		ret = append(ret, preserve+s)
-	}
-	return ret
-}
-
 func unescape(s string) string {
 	ret := ""
 	for {
diff --git a/androidmk/parser/make_strings_test.go b/androidmk/parser/make_strings_test.go
index 6995e89..fbb289b 100644
--- a/androidmk/parser/make_strings_test.go
+++ b/androidmk/parser/make_strings_test.go
@@ -26,64 +26,53 @@
 	n        int
 }{
 	{
-		in: &MakeString{
-			Strings: []string{
-				"a b c",
-				"d e f",
-				" h i j",
-			},
-			Variables: []Variable{
-				Variable{Name: SimpleMakeString("var1", NoPos)},
-				Variable{Name: SimpleMakeString("var2", NoPos)},
-			},
-		},
+		// "a b c$(var1)d e f$(var2) h i j"
+		in:  genMakeString("a b c", "var1", "d e f", "var2", " h i j"),
 		sep: " ",
 		n:   -1,
 		expected: []*MakeString{
-			SimpleMakeString("a", NoPos),
-			SimpleMakeString("b", NoPos),
-			&MakeString{
-				Strings: []string{"c", "d"},
-				Variables: []Variable{
-					Variable{Name: SimpleMakeString("var1", NoPos)},
-				},
-			},
-			SimpleMakeString("e", NoPos),
-			&MakeString{
-				Strings: []string{"f", ""},
-				Variables: []Variable{
-					Variable{Name: SimpleMakeString("var2", NoPos)},
-				},
-			},
-			SimpleMakeString("h", NoPos),
-			SimpleMakeString("i", NoPos),
-			SimpleMakeString("j", NoPos),
+			genMakeString("a"),
+			genMakeString("b"),
+			genMakeString("c", "var1", "d"),
+			genMakeString("e"),
+			genMakeString("f", "var2", ""),
+			genMakeString("h"),
+			genMakeString("i"),
+			genMakeString("j"),
 		},
 	},
 	{
-		in: &MakeString{
-			Strings: []string{
-				"a b c",
-				"d e f",
-				" h i j",
-			},
-			Variables: []Variable{
-				Variable{Name: SimpleMakeString("var1", NoPos)},
-				Variable{Name: SimpleMakeString("var2", NoPos)},
-			},
-		},
+		// "a b c$(var1)d e f$(var2) h i j"
+		in:  genMakeString("a b c", "var1", "d e f", "var2", " h i j"),
 		sep: " ",
 		n:   3,
 		expected: []*MakeString{
-			SimpleMakeString("a", NoPos),
-			SimpleMakeString("b", NoPos),
-			&MakeString{
-				Strings: []string{"c", "d e f", " h i j"},
-				Variables: []Variable{
-					Variable{Name: SimpleMakeString("var1", NoPos)},
-					Variable{Name: SimpleMakeString("var2", NoPos)},
-				},
-			},
+			genMakeString("a"),
+			genMakeString("b"),
+			genMakeString("c", "var1", "d e f", "var2", " h i j"),
+		},
+	},
+	{
+		// "$(var1) $(var2)"
+		in:  genMakeString("", "var1", " ", "var2", ""),
+		sep: " ",
+		n:   -1,
+		expected: []*MakeString{
+			genMakeString("", "var1", ""),
+			genMakeString("", "var2", ""),
+		},
+	},
+	{
+		// "a,,b,c,"
+		in:  genMakeString("a,,b,c,"),
+		sep: ",",
+		n:   -1,
+		expected: []*MakeString{
+			genMakeString("a"),
+			genMakeString(""),
+			genMakeString("b"),
+			genMakeString("c"),
+			genMakeString(""),
 		},
 	},
 }
@@ -104,15 +93,15 @@
 	expected string
 }{
 	{
-		in:       SimpleMakeString("a b", NoPos),
+		in:       genMakeString("a b"),
 		expected: "a b",
 	},
 	{
-		in:       SimpleMakeString("a\\ \\\tb\\\\", NoPos),
+		in:       genMakeString("a\\ \\\tb\\\\"),
 		expected: "a \tb\\",
 	},
 	{
-		in:       SimpleMakeString("a\\b\\", NoPos),
+		in:       genMakeString("a\\b\\"),
 		expected: "a\\b\\",
 	},
 }
@@ -131,31 +120,88 @@
 	expected []*MakeString
 }{
 	{
-		in:       SimpleMakeString("", NoPos),
+		in:       genMakeString(""),
 		expected: []*MakeString{},
 	},
 	{
-		in: SimpleMakeString(" a b\\ c d", NoPos),
+		in: genMakeString(` a b\ c d`),
 		expected: []*MakeString{
-			SimpleMakeString("a", NoPos),
-			SimpleMakeString("b\\ c", NoPos),
-			SimpleMakeString("d", NoPos),
+			genMakeString("a"),
+			genMakeString(`b\ c`),
+			genMakeString("d"),
 		},
 	},
 	{
-		in: SimpleMakeString("  a\tb\\\t\\ c d  ", NoPos),
+		in: SimpleMakeString("  a\tb"+`\`+"\t"+`\ c d  `, NoPos),
 		expected: []*MakeString{
-			SimpleMakeString("a", NoPos),
-			SimpleMakeString("b\\\t\\ c", NoPos),
-			SimpleMakeString("d", NoPos),
+			genMakeString("a"),
+			genMakeString("b" + `\` + "\t" + `\ c`),
+			genMakeString("d"),
 		},
 	},
 	{
-		in: SimpleMakeString(`a\\ b\\\ c d`, NoPos),
+		in: genMakeString(`a\\ b\\\ c d`),
 		expected: []*MakeString{
-			SimpleMakeString(`a\\`, NoPos),
-			SimpleMakeString(`b\\\ c`, NoPos),
-			SimpleMakeString("d", NoPos),
+			genMakeString(`a\\`),
+			genMakeString(`b\\\ c`),
+			genMakeString("d"),
+		},
+	},
+	{
+		in: genMakeString(`\\ a`),
+		expected: []*MakeString{
+			genMakeString(`\\`),
+			genMakeString("a"),
+		},
+	},
+	{
+		// "  "
+		in: &MakeString{
+			Strings:   []string{" \t \t"},
+			Variables: nil,
+		},
+		expected: []*MakeString{},
+	},
+	{
+		// " a $(X)b c "
+		in: genMakeString(" a ", "X", "b c "),
+		expected: []*MakeString{
+			genMakeString("a"),
+			genMakeString("", "X", "b"),
+			genMakeString("c"),
+		},
+	},
+	{
+		// " a b$(X)c d"
+		in: genMakeString(" a b", "X", "c d"),
+		expected: []*MakeString{
+			genMakeString("a"),
+			genMakeString("b", "X", "c"),
+			genMakeString("d"),
+		},
+	},
+	{
+		// "$(X) $(Y)"
+		in: genMakeString("", "X", " ", "Y", ""),
+		expected: []*MakeString{
+			genMakeString("", "X", ""),
+			genMakeString("", "Y", ""),
+		},
+	},
+	{
+		// " a$(X) b"
+		in: genMakeString(" a", "X", " b"),
+		expected: []*MakeString{
+			genMakeString("a", "X", ""),
+			genMakeString("b"),
+		},
+	},
+	{
+		// "a$(X) b$(Y) "
+		in: genMakeString("a", "X", " b", "Y", " "),
+		expected: []*MakeString{
+			genMakeString("a", "X", ""),
+			genMakeString("b", "Y", ""),
 		},
 	},
 }
@@ -180,3 +226,20 @@
 
 	return strings.Join(ret, "|||")
 }
+
+// generates MakeString from alternating string chunks and variable names,
+// e.g., genMakeString("a", "X", "b") returns MakeString for "a$(X)b"
+func genMakeString(items ...string) *MakeString {
+	n := len(items) / 2
+	if len(items) != (2*n + 1) {
+		panic("genMakeString expects odd number of arguments")
+	}
+
+	ms := &MakeString{Strings: make([]string, n+1), Variables: make([]Variable, n)}
+	ms.Strings[0] = items[0]
+	for i := 1; i <= n; i++ {
+		ms.Variables[i-1] = Variable{Name: SimpleMakeString(items[2*i-1], NoPos)}
+		ms.Strings[i] = items[2*i]
+	}
+	return ms
+}
diff --git a/androidmk/parser/parser.go b/androidmk/parser/parser.go
index c14910a..5afef65 100644
--- a/androidmk/parser/parser.go
+++ b/androidmk/parser/parser.go
@@ -553,12 +553,14 @@
 	"else",
 	"endef",
 	"endif",
+	"export",
 	"ifdef",
 	"ifeq",
 	"ifndef",
 	"ifneq",
 	"include",
 	"-include",
+	"unexport",
 }
 
 var functions = [...]string{
diff --git a/apex/allowed_deps.txt b/apex/allowed_deps.txt
index 5b8563d..a2f8797 100644
--- a/apex/allowed_deps.txt
+++ b/apex/allowed_deps.txt
@@ -132,6 +132,7 @@
 brotli-java(minSdkVersion:current)
 captiveportal-lib(minSdkVersion:29)
 car-ui-lib(minSdkVersion:28)
+car-ui-lib-overlayable(minSdkVersion:28)
 CellBroadcastApp(minSdkVersion:29)
 CellBroadcastServiceModule(minSdkVersion:29)
 codecs_g711dec(minSdkVersion:29)
@@ -333,6 +334,7 @@
 libminijail_gen_syscall_obj(minSdkVersion:29)
 libminijail_generated(minSdkVersion:29)
 libmkvextractor(minSdkVersion:29)
+libmodules-utils-build(minSdkVersion:29)
 libmp3extractor(minSdkVersion:29)
 libmp4extractor(minSdkVersion:29)
 libmpeg2dec(minSdkVersion:29)
@@ -446,6 +448,7 @@
 neuralnetworks_utils_hal_1_2(minSdkVersion:30)
 neuralnetworks_utils_hal_1_3(minSdkVersion:30)
 neuralnetworks_utils_hal_common(minSdkVersion:30)
+neuralnetworks_utils_hal_service(minSdkVersion:30)
 PermissionController(minSdkVersion:28)
 permissioncontroller-statsd(minSdkVersion:current)
 philox_random(minSdkVersion:(no version))
diff --git a/apex/androidmk.go b/apex/androidmk.go
index da38c2a..6c76ad3f 100644
--- a/apex/androidmk.go
+++ b/apex/androidmk.go
@@ -360,7 +360,11 @@
 				fmt.Fprintln(w, "LOCAL_MODULE_CLASS := ETC") // do we need a new class?
 				fmt.Fprintln(w, "LOCAL_PREBUILT_MODULE_FILE :=", a.outputFile.String())
 				fmt.Fprintln(w, "LOCAL_MODULE_PATH :=", a.installDir.ToMakePath().String())
-				fmt.Fprintln(w, "LOCAL_MODULE_STEM :=", name+apexType.suffix())
+				stemSuffix := apexType.suffix()
+				if a.isCompressed {
+					stemSuffix = ".capex"
+				}
+				fmt.Fprintln(w, "LOCAL_MODULE_STEM :=", name+stemSuffix)
 				fmt.Fprintln(w, "LOCAL_UNINSTALLABLE_MODULE :=", !a.installable())
 
 				// Because apex writes .mk with Custom(), we need to write manually some common properties
diff --git a/apex/apex.go b/apex/apex.go
index 7ab7454..2a81b9b 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -55,7 +55,7 @@
 }
 
 func RegisterPostDepsMutators(ctx android.RegisterMutatorsContext) {
-	ctx.TopDown("apex_deps", apexDepsMutator).Parallel()
+	ctx.TopDown("apex_info", apexInfoMutator).Parallel()
 	ctx.BottomUp("apex_unique", apexUniqueVariationsMutator).Parallel()
 	ctx.BottomUp("apex_test_for_deps", apexTestForDepsMutator).Parallel()
 	ctx.BottomUp("apex_test_for", apexTestForMutator).Parallel()
@@ -120,6 +120,12 @@
 	// Default: true.
 	Installable *bool
 
+	// Whether this APEX can be compressed or not. Setting this property to false means this
+	// APEX will never be compressed. When set to true, APEX will be compressed if other
+	// conditions, e.g, target device needs to support APEX compression, are also fulfilled.
+	// Default: true.
+	Compressible *bool
+
 	// For native libraries and binaries, use the vendor variant instead of the core (platform)
 	// variant. Default is false. DO NOT use this for APEXes that are installed to the system or
 	// system_ext partition.
@@ -354,6 +360,8 @@
 
 	prebuiltFileToDelete string
 
+	isCompressed bool
+
 	// Path of API coverage generate file
 	coverageOutputPath android.ModuleOutPath
 }
@@ -483,12 +491,12 @@
 // 1) DepsMutator: from the properties like native_shared_libs, java_libs, etc., modules are added
 // to the (direct) dependencies of this APEX bundle.
 //
-// 2) apexDepsMutator: this is a post-deps mutator, so runs after DepsMutator. Its goal is to
+// 2) apexInfoMutator: this is a post-deps mutator, so runs after DepsMutator. Its goal is to
 // collect modules that are direct and transitive dependencies of each APEX bundle. The collected
 // modules are marked as being included in the APEX via BuildForApex().
 //
-// 3) apexMutator: this is a post-deps mutator that runs after apexDepsMutator. For each module that
-// are marked by the apexDepsMutator, apex variations are created using CreateApexVariations().
+// 3) apexMutator: this is a post-deps mutator that runs after apexInfoMutator. For each module that
+// are marked by the apexInfoMutator, apex variations are created using CreateApexVariations().
 
 type dependencyTag struct {
 	blueprint.BaseDependencyTag
@@ -522,11 +530,8 @@
 
 	if ctx.Device() {
 		binVariations = append(binVariations, blueprint.Variation{Mutator: "image", Variation: imageVariation})
-		libVariations = append(libVariations,
-			blueprint.Variation{Mutator: "image", Variation: imageVariation},
-			blueprint.Variation{Mutator: "version", Variation: ""}) // "" is the non-stub variant
-		rustLibVariations = append(rustLibVariations,
-			blueprint.Variation{Mutator: "image", Variation: imageVariation})
+		libVariations = append(libVariations, blueprint.Variation{Mutator: "image", Variation: imageVariation})
+		rustLibVariations = append(rustLibVariations, blueprint.Variation{Mutator: "image", Variation: imageVariation})
 	}
 
 	// Use *FarVariation* to be able to depend on modules having conflicting variations with
@@ -721,14 +726,20 @@
 	Contents *android.ApexContents
 }
 
-var ApexBundleInfoProvider = blueprint.NewMutatorProvider(ApexBundleInfo{}, "apex_deps")
+var ApexBundleInfoProvider = blueprint.NewMutatorProvider(ApexBundleInfo{}, "apex_info")
 
-// apexDepsMutator is responsible for collecting modules that need to have apex variants. They are
+// apexInfoMutator is responsible for collecting modules that need to have apex variants. They are
 // identified by doing a graph walk starting from an apexBundle. Basically, all the (direct and
 // indirect) dependencies are collected. But a few types of modules that shouldn't be included in
 // the apexBundle (e.g. stub libraries) are not collected. Note that a single module can be depended
 // on by multiple apexBundles. In that case, the module is collected for all of the apexBundles.
-func apexDepsMutator(mctx android.TopDownMutatorContext) {
+//
+// For each dependency between an apex and an ApexModule an ApexInfo object describing the apex
+// is passed to that module's BuildForApex(ApexInfo) method which collates them all in a list.
+// The apexMutator uses that list to create module variants for the apexes to which it belongs.
+// The relationship between module variants and apexes is not one-to-one as variants will be
+// shared between compatible apexes.
+func apexInfoMutator(mctx android.TopDownMutatorContext) {
 	if !mctx.Module().Enabled() {
 		return
 	}
@@ -910,7 +921,7 @@
 }
 
 // apexMutator visits each module and creates apex variations if the module was marked in the
-// previous run of apexDepsMutator.
+// previous run of apexInfoMutator.
 func apexMutator(mctx android.BottomUpMutatorContext) {
 	if !mctx.Module().Enabled() {
 		return
@@ -1522,6 +1533,9 @@
 						provideNativeLibs = append(provideNativeLibs, fi.stem())
 					}
 					return true // track transitive dependencies
+				} else if r, ok := child.(*rust.Module); ok {
+					fi := apexFileForRustLibrary(ctx, r)
+					filesInfo = append(filesInfo, fi)
 				} else {
 					propertyName := "native_shared_libs"
 					if isJniLib {
@@ -1681,6 +1695,24 @@
 							// Don't track further
 							return false
 						}
+
+						// If the dep is not considered to be in the same
+						// apex, don't add it to filesInfo so that it is not
+						// included in this APEX.
+						// TODO(jiyong): move this to at the top of the
+						// else-if clause for the indirect dependencies.
+						// Currently, that's impossible because we would
+						// like to record requiredNativeLibs even when
+						// DepIsInSameAPex is false.
+						if !am.DepIsInSameApex(ctx, am) {
+							return false
+						}
+
+						filesInfo = append(filesInfo, af)
+						return true // track transitive dependencies
+					} else if rm, ok := child.(*rust.Module); ok {
+						af := apexFileForRustLibrary(ctx, rm)
+						af.transitiveDep = true
 						filesInfo = append(filesInfo, af)
 						return true // track transitive dependencies
 					}
@@ -1697,6 +1729,8 @@
 						filesInfo = append(filesInfo, af)
 						return true // track transitive dependencies
 					}
+				} else if cc.IsHeaderDepTag(depTag) {
+					// nothing
 				} else if java.IsJniDepTag(depTag) {
 					// Because APK-in-APEX embeds jni_libs transitively, we don't need to track transitive deps
 					return false
diff --git a/apex/apex_test.go b/apex/apex_test.go
index 0b67ef5..ab8ae16 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -346,6 +346,13 @@
 	}
 }
 
+func ensureListNotEmpty(t *testing.T, result []string) {
+	t.Helper()
+	if len(result) == 0 {
+		t.Errorf("%q is expected to be not empty", result)
+	}
+}
+
 // Minimal test
 func TestBasicApex(t *testing.T) {
 	ctx, config := testApex(t, `
@@ -355,7 +362,10 @@
 			androidManifest: ":myapex.androidmanifest",
 			key: "myapex.key",
 			binaries: ["foo.rust"],
-			native_shared_libs: ["mylib"],
+			native_shared_libs: [
+				"mylib",
+				"libfoo.ffi",
+			],
 			rust_dyn_libs: ["libfoo.dylib.rust"],
 			multilib: {
 				both: {
@@ -392,7 +402,10 @@
 		cc_library {
 			name: "mylib",
 			srcs: ["mylib.cpp"],
-			shared_libs: ["mylib2"],
+			shared_libs: [
+				"mylib2",
+				"libbar.ffi",
+			],
 			system_shared_libs: [],
 			stl: "none",
 			// TODO: remove //apex_available:platform
@@ -444,6 +457,20 @@
 			apex_available: ["myapex"],
 		}
 
+		rust_ffi_shared {
+			name: "libfoo.ffi",
+			srcs: ["foo.rs"],
+			crate_name: "foo",
+			apex_available: ["myapex"],
+		}
+
+		rust_ffi_shared {
+			name: "libbar.ffi",
+			srcs: ["foo.rs"],
+			crate_name: "bar",
+			apex_available: ["myapex"],
+		}
+
 		apex {
 			name: "com.android.gki.fake",
 			binaries: ["foo"],
@@ -559,12 +586,14 @@
 	ensureListContains(t, ctx.ModuleVariantsForTests("myjar"), "android_common_apex10000")
 	ensureListContains(t, ctx.ModuleVariantsForTests("myjar_dex"), "android_common_apex10000")
 	ensureListContains(t, ctx.ModuleVariantsForTests("foo.rust"), "android_arm64_armv8-a_apex10000")
+	ensureListContains(t, ctx.ModuleVariantsForTests("libfoo.ffi"), "android_arm64_armv8-a_shared_apex10000")
 
 	// Ensure that apex variant is created for the indirect dep
 	ensureListContains(t, ctx.ModuleVariantsForTests("mylib2"), "android_arm64_armv8-a_shared_apex10000")
 	ensureListContains(t, ctx.ModuleVariantsForTests("myotherjar"), "android_common_apex10000")
 	ensureListContains(t, ctx.ModuleVariantsForTests("libfoo.rlib.rust"), "android_arm64_armv8-a_rlib_dylib-std_apex10000")
 	ensureListContains(t, ctx.ModuleVariantsForTests("libfoo.dylib.rust"), "android_arm64_armv8-a_dylib_apex10000")
+	ensureListContains(t, ctx.ModuleVariantsForTests("libbar.ffi"), "android_arm64_armv8-a_shared_apex10000")
 
 	// Ensure that both direct and indirect deps are copied into apex
 	ensureContains(t, copyCmds, "image.apex/lib64/mylib.so")
@@ -572,6 +601,8 @@
 	ensureContains(t, copyCmds, "image.apex/javalib/myjar_stem.jar")
 	ensureContains(t, copyCmds, "image.apex/javalib/myjar_dex.jar")
 	ensureContains(t, copyCmds, "image.apex/lib64/libfoo.dylib.rust.dylib.so")
+	ensureContains(t, copyCmds, "image.apex/lib64/libfoo.ffi.so")
+	ensureContains(t, copyCmds, "image.apex/lib64/libbar.ffi.so")
 	// .. but not for java libs
 	ensureNotContains(t, copyCmds, "image.apex/javalib/myotherjar.jar")
 	ensureNotContains(t, copyCmds, "image.apex/javalib/msharedjar.jar")
@@ -1782,6 +1813,31 @@
 			min_sdk_version: "30",
 		}
 	`)
+
+	testApexError(t, `module "libfoo.ffi".*: should support min_sdk_version\(29\)`, `
+		apex {
+			name: "myapex",
+			key: "myapex.key",
+			native_shared_libs: ["libfoo.ffi"],
+			min_sdk_version: "29",
+		}
+
+		apex_key {
+			name: "myapex.key",
+			public_key: "testkey.avbpubkey",
+			private_key: "testkey.pem",
+		}
+
+		rust_ffi_shared {
+			name: "libfoo.ffi",
+			srcs: ["foo.rs"],
+			crate_name: "foo",
+			apex_available: [
+				"myapex",
+			],
+			min_sdk_version: "30",
+		}
+	`)
 }
 
 func TestApexMinSdkVersion_Okay(t *testing.T) {
@@ -5635,6 +5691,13 @@
 			],
 		}
 	`
+
+	testDexpreoptWithApexes(t, bp, errmsg, transformDexpreoptConfig)
+}
+
+func testDexpreoptWithApexes(t *testing.T, bp, errmsg string, transformDexpreoptConfig func(*dexpreopt.GlobalConfig)) {
+	t.Helper()
+
 	bp += cc.GatherRequiredDepsForTest(android.Android)
 	bp += java.GatherRequiredDepsForTest()
 	bp += dexpreopt.BpToolModulesForTest()
@@ -5964,9 +6027,27 @@
 			srcs: ["mylib.cpp"],
 			system_shared_libs: [],
 			stl: "none",
-			shared_libs: ["mylib", "myprivlib"],
+			shared_libs: ["mylib", "myprivlib", "mytestlib"],
 			test_for: ["myapex"]
 		}
+
+		cc_library {
+			name: "mytestlib",
+			srcs: ["mylib.cpp"],
+			system_shared_libs: [],
+			shared_libs: ["mylib", "myprivlib"],
+			stl: "none",
+			test_for: ["myapex"],
+		}
+
+		cc_benchmark {
+			name: "mybench",
+			srcs: ["mylib.cpp"],
+			system_shared_libs: [],
+			shared_libs: ["mylib", "myprivlib"],
+			stl: "none",
+			test_for: ["myapex"],
+		}
 	`)
 
 	// the test 'mytest' is a test for the apex, therefore is linked to the
@@ -5974,6 +6055,16 @@
 	ldFlags := ctx.ModuleForTests("mytest", "android_arm64_armv8-a").Rule("ld").Args["libFlags"]
 	ensureContains(t, ldFlags, "mylib/android_arm64_armv8-a_shared/mylib.so")
 	ensureNotContains(t, ldFlags, "mylib/android_arm64_armv8-a_shared_1/mylib.so")
+
+	// The same should be true for cc_library
+	ldFlags = ctx.ModuleForTests("mytestlib", "android_arm64_armv8-a_shared").Rule("ld").Args["libFlags"]
+	ensureContains(t, ldFlags, "mylib/android_arm64_armv8-a_shared/mylib.so")
+	ensureNotContains(t, ldFlags, "mylib/android_arm64_armv8-a_shared_1/mylib.so")
+
+	// ... and for cc_benchmark
+	ldFlags = ctx.ModuleForTests("mybench", "android_arm64_armv8-a").Rule("ld").Args["libFlags"]
+	ensureContains(t, ldFlags, "mylib/android_arm64_armv8-a_shared/mylib.so")
+	ensureNotContains(t, ldFlags, "mylib/android_arm64_armv8-a_shared_1/mylib.so")
 }
 
 // TODO(jungjw): Move this to proptools
@@ -6186,6 +6277,40 @@
 	`)
 }
 
+func TestCompressedApex(t *testing.T) {
+	ctx, config := testApex(t, `
+		apex {
+			name: "myapex",
+			key: "myapex.key",
+			compressible: true,
+		}
+		apex_key {
+			name: "myapex.key",
+			public_key: "testkey.avbpubkey",
+			private_key: "testkey.pem",
+		}
+	`, func(fs map[string][]byte, config android.Config) {
+		config.TestProductVariables.CompressedApex = proptools.BoolPtr(true)
+	})
+
+	compressRule := ctx.ModuleForTests("myapex", "android_common_myapex_image").Rule("compressRule")
+	ensureContains(t, compressRule.Output.String(), "myapex.capex.unsigned")
+
+	signApkRule := ctx.ModuleForTests("myapex", "android_common_myapex_image").Description("sign compressedApex")
+	ensureEquals(t, signApkRule.Input.String(), compressRule.Output.String())
+
+	// Make sure output of bundle is .capex
+	ab := ctx.ModuleForTests("myapex", "android_common_myapex_image").Module().(*apexBundle)
+	ensureContains(t, ab.outputFile.String(), "myapex.capex")
+
+	// Verify android.mk rules
+	data := android.AndroidMkDataForTest(t, config, "", ab)
+	var builder strings.Builder
+	data.Custom(&builder, ab.BaseModuleName(), "TARGET_", "", data)
+	androidMk := builder.String()
+	ensureContains(t, androidMk, "LOCAL_MODULE_STEM := myapex.capex\n")
+}
+
 func TestPreferredPrebuiltSharedLibDep(t *testing.T) {
 	ctx, config := testApex(t, `
 		apex {
@@ -6237,6 +6362,55 @@
 	ensureContains(t, androidMk, "LOCAL_REQUIRED_MODULES += otherlib\n")
 }
 
+func TestExcludeDependency(t *testing.T) {
+	ctx, _ := testApex(t, `
+		apex {
+			name: "myapex",
+			key: "myapex.key",
+			native_shared_libs: ["mylib"],
+		}
+
+		apex_key {
+			name: "myapex.key",
+			public_key: "testkey.avbpubkey",
+			private_key: "testkey.pem",
+		}
+
+		cc_library {
+			name: "mylib",
+			srcs: ["mylib.cpp"],
+			system_shared_libs: [],
+			stl: "none",
+			apex_available: ["myapex"],
+			shared_libs: ["mylib2"],
+			target: {
+				apex: {
+					exclude_shared_libs: ["mylib2"],
+				},
+			},
+		}
+
+		cc_library {
+			name: "mylib2",
+			srcs: ["mylib.cpp"],
+			system_shared_libs: [],
+			stl: "none",
+		}
+	`)
+
+	// Check if mylib is linked to mylib2 for the non-apex target
+	ldFlags := ctx.ModuleForTests("mylib", "android_arm64_armv8-a_shared").Rule("ld").Args["libFlags"]
+	ensureContains(t, ldFlags, "mylib2/android_arm64_armv8-a_shared/mylib2.so")
+
+	// Make sure that the link doesn't occur for the apex target
+	ldFlags = ctx.ModuleForTests("mylib", "android_arm64_armv8-a_shared_apex10000").Rule("ld").Args["libFlags"]
+	ensureNotContains(t, ldFlags, "mylib2/android_arm64_armv8-a_shared_apex10000/mylib2.so")
+
+	// It shouldn't appear in the copy cmd as well.
+	copyCmds := ctx.ModuleForTests("myapex", "android_common_myapex_image").Rule("apexRule").Args["copy_commands"]
+	ensureNotContains(t, copyCmds, "image.apex/lib64/mylib2.so")
+}
+
 func TestMain(m *testing.M) {
 	run := func() int {
 		setUp()
diff --git a/apex/builder.go b/apex/builder.go
index 66eaff1..9db8e59 100644
--- a/apex/builder.go
+++ b/apex/builder.go
@@ -66,6 +66,7 @@
 	pctx.HostBinToolVariable("extract_apks", "extract_apks")
 	pctx.HostBinToolVariable("make_f2fs", "make_f2fs")
 	pctx.HostBinToolVariable("sload_f2fs", "sload_f2fs")
+	pctx.HostBinToolVariable("apex_compression_tool", "apex_compression_tool")
 	pctx.SourcePathVariable("genNdkUsedbyApexPath", "build/soong/scripts/gen_ndk_usedby_apex.sh")
 }
 
@@ -738,7 +739,7 @@
 
 	////////////////////////////////////////////////////////////////////////////////////
 	// Step 4: Sign the APEX using signapk
-	a.outputFile = android.PathForModuleOut(ctx, a.Name()+suffix)
+	signedOutputFile := android.PathForModuleOut(ctx, a.Name()+suffix)
 
 	pem, key := a.getCertificateAndPrivateKey(ctx)
 	rule := java.Signapk
@@ -750,16 +751,47 @@
 	if ctx.Config().UseRBE() && ctx.Config().IsEnvTrue("RBE_SIGNAPK") {
 		rule = java.SignapkRE
 		args["implicits"] = strings.Join(implicits.Strings(), ",")
-		args["outCommaList"] = a.outputFile.String()
+		args["outCommaList"] = signedOutputFile.String()
 	}
 	ctx.Build(pctx, android.BuildParams{
 		Rule:        rule,
 		Description: "signapk",
-		Output:      a.outputFile,
+		Output:      signedOutputFile,
 		Input:       unsignedOutputFile,
 		Implicits:   implicits,
 		Args:        args,
 	})
+	a.outputFile = signedOutputFile
+
+	// Process APEX compression if enabled
+	compressionEnabled := ctx.Config().CompressedApex() && proptools.BoolDefault(a.properties.Compressible, true)
+	if compressionEnabled && apexType == imageApex {
+		a.isCompressed = true
+		unsignedCompressedOutputFile := android.PathForModuleOut(ctx, a.Name()+".capex.unsigned")
+
+		compressRule := android.NewRuleBuilder(pctx, ctx)
+		compressRule.Command().
+			Text("rm").
+			FlagWithOutput("-f ", unsignedCompressedOutputFile)
+		compressRule.Command().
+			BuiltTool("apex_compression_tool").
+			Flag("compress").
+			FlagWithArg("--apex_compression_tool ", outHostBinDir+":"+prebuiltSdkToolsBinDir).
+			FlagWithInput("--input ", signedOutputFile).
+			FlagWithOutput("--output ", unsignedCompressedOutputFile)
+		compressRule.Build("compressRule", "Generate unsigned compressed APEX file")
+
+		signedCompressedOutputFile := android.PathForModuleOut(ctx, a.Name()+".capex")
+		ctx.Build(pctx, android.BuildParams{
+			Rule:        rule,
+			Description: "sign compressedApex",
+			Output:      signedCompressedOutputFile,
+			Input:       unsignedCompressedOutputFile,
+			Implicits:   implicits,
+			Args:        args,
+		})
+		a.outputFile = signedCompressedOutputFile
+	}
 
 	// Install to $OUT/soong/{target,host}/.../apex
 	if a.installable() {
diff --git a/cc/Android.bp b/cc/Android.bp
index 88104e2..33f3db2 100644
--- a/cc/Android.bp
+++ b/cc/Android.bp
@@ -31,6 +31,7 @@
         "sanitize.go",
         "sabi.go",
         "sdk.go",
+        "snapshot_prebuilt.go",
         "snapshot_utils.go",
         "stl.go",
         "strip.go",
diff --git a/cc/androidmk.go b/cc/androidmk.go
index 3619fd8..4f4b047 100644
--- a/cc/androidmk.go
+++ b/cc/androidmk.go
@@ -130,7 +130,7 @@
 			},
 		},
 		ExtraFooters: []android.AndroidMkExtraFootersFunc{
-			func(w io.Writer, name, prefix, moduleDir string, entries *android.AndroidMkEntries) {
+			func(w io.Writer, name, prefix, moduleDir string) {
 				if c.Properties.IsSdkVariant && c.Properties.SdkAndPlatformVariantVisibleToMake &&
 					c.CcLibraryInterface() && c.Shared() {
 					// Using the SDK variant as a JNI library needs a copy of the .so that
@@ -296,7 +296,7 @@
 func (object *objectLinker) AndroidMkEntries(ctx AndroidMkContext, entries *android.AndroidMkEntries) {
 	entries.Class = "STATIC_LIBRARIES"
 	entries.ExtraFooters = append(entries.ExtraFooters,
-		func(w io.Writer, name, prefix, moduleDir string, entries *android.AndroidMkEntries) {
+		func(w io.Writer, name, prefix, moduleDir string) {
 			out := entries.OutputFile.Path()
 			varname := fmt.Sprintf("SOONG_%sOBJECT_%s%s", prefix, name, entries.SubName)
 
@@ -574,7 +574,7 @@
 	}
 
 	entries.ExtraFooters = append(entries.ExtraFooters,
-		func(w io.Writer, name, prefix, moduleDir string, entries *android.AndroidMkEntries) {
+		func(w io.Writer, name, prefix, moduleDir string) {
 			out := entries.OutputFile.Path()
 			varname := fmt.Sprintf("SOONG_%sOBJECT_%s%s", prefix, name, entries.SubName)
 
diff --git a/cc/builder.go b/cc/builder.go
index 5545a5b..9cd78d5 100644
--- a/cc/builder.go
+++ b/cc/builder.go
@@ -235,6 +235,7 @@
 		}, &remoteexec.REParams{
 			Labels:       map[string]string{"type": "abi-dump", "tool": "header-abi-dumper"},
 			ExecStrategy: "${config.REAbiDumperExecStrategy}",
+			Inputs:       []string{"$sAbiLinkerLibs"},
 			Platform: map[string]string{
 				remoteexec.PoolKey: "${config.RECXXPool}",
 			},
diff --git a/cc/cc.go b/cc/cc.go
index ffba579..9383e39 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -129,6 +129,9 @@
 	// Used for host bionic
 	LinkerFlagsFile string
 	DynamicLinker   string
+
+	// List of libs that need to be excluded for APEX variant
+	ExcludeLibsForApex []string
 }
 
 // PathDeps is a struct containing file paths to dependencies of a module.
@@ -332,6 +335,11 @@
 	// framework module from a snapshot.
 	Exclude_from_vendor_snapshot   *bool
 	Exclude_from_recovery_snapshot *bool
+
+	// List of APEXes that this module has private access to for testing purpose. The module
+	// can depend on libraries that are not exported by the APEXes and use private symbols
+	// from the exported libraries.
+	Test_for []string
 }
 
 type VendorProperties struct {
@@ -572,6 +580,9 @@
 	staticUnwinder bool
 
 	makeSuffix string
+
+	// Whether or not this dependency has to be followed for the apex variants
+	excludeInApex bool
 }
 
 // header returns true if the libraryDependencyTag is tagging a header lib dependency.
@@ -1590,7 +1601,7 @@
 
 		// glob exported headers for snapshot, if BOARD_VNDK_VERSION is current.
 		if i, ok := c.linker.(snapshotLibraryInterface); ok && ctx.DeviceConfig().VndkVersion() == "current" {
-			if isSnapshotAware(ctx, c, apexInfo) {
+			if shouldCollectHeadersForSnapshot(ctx, c, apexInfo) {
 				i.collectHeadersForSnapshot(ctx)
 			}
 		}
@@ -1881,13 +1892,6 @@
 		}
 	}
 
-	buildStubs := false
-	if versioned, ok := c.linker.(versionedInterface); ok {
-		if versioned.buildStubs() {
-			buildStubs = true
-		}
-	}
-
 	rewriteSnapshotLibs := func(lib string, snapshotMap *snapshotMap) string {
 		// only modules with BOARD_VNDK_VERSION uses snapshot.
 		if c.VndkVersion() != actx.DeviceConfig().VndkVersion() {
@@ -1910,7 +1914,7 @@
 
 		lib = rewriteSnapshotLibs(lib, vendorSnapshotHeaderLibs)
 
-		if buildStubs {
+		if c.IsStubs() {
 			actx.AddFarVariationDependencies(append(ctx.Target().Variations(), c.ImageVariation()),
 				depTag, lib)
 		} else {
@@ -1918,12 +1922,6 @@
 		}
 	}
 
-	if buildStubs {
-		// Stubs lib does not have dependency to other static/shared libraries.
-		// Don't proceed.
-		return
-	}
-
 	// sysprop_library has to support both C++ and Java. So sysprop_library internally creates one
 	// C++ implementation library and one Java implementation library. When a module links against
 	// sysprop_library, the C++ implementation library has to be linked. syspropImplLibraries is a
@@ -1950,6 +1948,9 @@
 		if inList(lib, deps.ReexportStaticLibHeaders) {
 			depTag.reexportFlags = true
 		}
+		if inList(lib, deps.ExcludeLibsForApex) {
+			depTag.excludeInApex = true
+		}
 
 		if impl, ok := syspropImplLibraries[lib]; ok {
 			lib = impl
@@ -1987,6 +1988,9 @@
 		if inList(lib, deps.ReexportSharedLibHeaders) {
 			depTag.reexportFlags = true
 		}
+		if inList(lib, deps.ExcludeLibsForApex) {
+			depTag.excludeInApex = true
+		}
 
 		if impl, ok := syspropImplLibraries[lib]; ok {
 			lib = impl
@@ -2242,6 +2246,11 @@
 			return false
 		}
 
+		depTag := ctx.OtherModuleDependencyTag(child)
+		if IsHeaderDepTag(depTag) {
+			return false
+		}
+
 		// Even if target lib has no vendor variant, keep checking dependency
 		// graph in case it depends on vendor_available or product_available
 		// but not double_loadable transtively.
@@ -2275,8 +2284,8 @@
 // For example, with maxSdkVersion is 10 and versionList is [9,11]
 // it returns 9 as string.  The list of stubs must be in order from
 // oldest to newest.
-func (c *Module) chooseSdkVersion(ctx android.PathContext, stubsInfo []SharedLibraryStubsInfo,
-	maxSdkVersion android.ApiLevel) (SharedLibraryStubsInfo, error) {
+func (c *Module) chooseSdkVersion(ctx android.PathContext, stubsInfo []SharedStubLibrary,
+	maxSdkVersion android.ApiLevel) (SharedStubLibrary, error) {
 
 	for i := range stubsInfo {
 		stubInfo := stubsInfo[len(stubsInfo)-i-1]
@@ -2287,7 +2296,7 @@
 			var err error
 			ver, err = android.ApiLevelFromUser(ctx, stubInfo.Version)
 			if err != nil {
-				return SharedLibraryStubsInfo{}, err
+				return SharedStubLibrary{}, err
 			}
 		}
 		if ver.LessThanOrEqualTo(maxSdkVersion) {
@@ -2298,7 +2307,7 @@
 	for _, stubInfo := range stubsInfo {
 		versionList = append(versionList, stubInfo.Version)
 	}
-	return SharedLibraryStubsInfo{}, fmt.Errorf("not found a version(<=%s) in versionList: %v", maxSdkVersion.String(), versionList)
+	return SharedStubLibrary{}, fmt.Errorf("not found a version(<=%s) in versionList: %v", maxSdkVersion.String(), versionList)
 }
 
 // Convert dependencies to paths.  Returns a PathDeps containing paths
@@ -2421,6 +2430,10 @@
 				return
 			}
 
+			if !apexInfo.IsForPlatform() && libDepTag.excludeInApex {
+				return
+			}
+
 			depExporterInfo := ctx.OtherModuleProvider(dep, FlagExporterInfoProvider).(FlagExporterInfo)
 
 			var ptr *android.Paths
@@ -2440,10 +2453,11 @@
 					}
 					return
 				}
-				sharedLibraryInfo := ctx.OtherModuleProvider(dep, SharedLibraryInfoProvider).(SharedLibraryInfo)
-				sharedLibraryStubsInfo := ctx.OtherModuleProvider(dep, SharedLibraryImplementationStubsInfoProvider).(SharedLibraryImplementationStubsInfo)
 
-				if !libDepTag.explicitlyVersioned && len(sharedLibraryStubsInfo.SharedLibraryStubsInfos) > 0 {
+				sharedLibraryInfo := ctx.OtherModuleProvider(dep, SharedLibraryInfoProvider).(SharedLibraryInfo)
+				sharedLibraryStubsInfo := ctx.OtherModuleProvider(dep, SharedLibraryStubsProvider).(SharedLibraryStubsInfo)
+
+				if !libDepTag.explicitlyVersioned && len(sharedLibraryStubsInfo.SharedStubLibraries) > 0 {
 					useStubs := false
 
 					if lib := moduleLibraryInterface(dep); lib.buildStubs() && c.UseVndk() { // LLNDK
@@ -2478,7 +2492,7 @@
 					// when to use (unspecified) stubs, check min_sdk_version and choose the right one
 					if useStubs {
 						sharedLibraryStubsInfo, err :=
-							c.chooseSdkVersion(ctx, sharedLibraryStubsInfo.SharedLibraryStubsInfos, c.apexSdkVersion)
+							c.chooseSdkVersion(ctx, sharedLibraryStubsInfo.SharedStubLibraries, c.apexSdkVersion)
 						if err != nil {
 							ctx.OtherModuleErrorf(dep, err.Error())
 							return
@@ -2488,6 +2502,12 @@
 					}
 				}
 
+				// Stubs lib doesn't link to the shared lib dependencies. Don't set
+				// linkFile, depFile, and ptr.
+				if c.IsStubs() {
+					break
+				}
+
 				linkFile = android.OptionalPathForPath(sharedLibraryInfo.SharedLibrary)
 				depFile = sharedLibraryInfo.TableOfContents
 
@@ -2515,6 +2535,13 @@
 					}
 					return
 				}
+
+				// Stubs lib doesn't link to the static lib dependencies. Don't set
+				// linkFile, depFile, and ptr.
+				if c.IsStubs() {
+					break
+				}
+
 				staticLibraryInfo := ctx.OtherModuleProvider(dep, StaticLibraryInfoProvider).(StaticLibraryInfo)
 				linkFile = android.OptionalPathForPath(staticLibraryInfo.StaticLibrary)
 				if libDepTag.wholeStatic {
@@ -2642,7 +2669,9 @@
 						c.Properties.AndroidMkStaticLibs, makeLibName)
 				}
 			}
-		} else {
+		} else if !c.IsStubs() {
+			// Stubs lib doesn't link to the runtime lib, object, crt, etc. dependencies.
+
 			switch depTag {
 			case runtimeDepTag:
 				c.Properties.AndroidMkRuntimeLibs = append(
@@ -2942,13 +2971,7 @@
 }
 
 func (c *Module) TestFor() []string {
-	if test, ok := c.linker.(interface {
-		testFor() []string
-	}); ok {
-		return test.testFor()
-	} else {
-		return c.ApexModuleBase.TestFor()
-	}
+	return c.Properties.Test_for
 }
 
 func (c *Module) UniqueApexVariations() bool {
@@ -3022,6 +3045,10 @@
 			// linked; the dependency is used only during the compilation phase.
 			return false
 		}
+
+		if isLibDepTag && libDepTag.excludeInApex {
+			return false
+		}
 	}
 	if depTag == stubImplDepTag || depTag == llndkImplDep {
 		// We don't track beyond LLNDK or from an implementation library to its stubs.
diff --git a/cc/cc_test.go b/cc/cc_test.go
index 456ce53..c16cce8 100644
--- a/cc/cc_test.go
+++ b/cc/cc_test.go
@@ -4056,3 +4056,35 @@
 	}
 
 }
+
+func TestStubsLibReexportsHeaders(t *testing.T) {
+	ctx := testCc(t, `
+		cc_library_shared {
+			name: "libclient",
+			srcs: ["foo.c"],
+			shared_libs: ["libfoo#1"],
+		}
+
+		cc_library_shared {
+			name: "libfoo",
+			srcs: ["foo.c"],
+			shared_libs: ["libbar"],
+			export_shared_lib_headers: ["libbar"],
+			stubs: {
+				symbol_file: "foo.map.txt",
+				versions: ["1", "2", "3"],
+			},
+		}
+
+		cc_library_shared {
+			name: "libbar",
+			export_include_dirs: ["include/libbar"],
+			srcs: ["foo.c"],
+		}`)
+
+	cFlags := ctx.ModuleForTests("libclient", "android_arm64_armv8-a_shared").Rule("cc").Args["cFlags"]
+
+	if !strings.Contains(cFlags, "-Iinclude/libbar") {
+		t.Errorf("expected %q in cflags, got %q", "-Iinclude/libbar", cFlags)
+	}
+}
diff --git a/cc/config/vndk.go b/cc/config/vndk.go
index 563ce76..a548452 100644
--- a/cc/config/vndk.go
+++ b/cc/config/vndk.go
@@ -21,7 +21,6 @@
 	"android.hardware.automotive.occupant_awareness-ndk_platform",
 	"android.hardware.light-ndk_platform",
 	"android.hardware.identity-ndk_platform",
-	"android.hardware.keymint-ndk_platform",
 	"android.hardware.keymint-unstable-ndk_platform",
 	"android.hardware.nfc@1.2",
 	"android.hardware.power-ndk_platform",
diff --git a/cc/library.go b/cc/library.go
index 00bb4bc..06b9905 100644
--- a/cc/library.go
+++ b/cc/library.go
@@ -28,6 +28,7 @@
 	"android/soong/cc/config"
 )
 
+// LibraryProperties is a collection of properties shared by cc library rules.
 type LibraryProperties struct {
 	// local file name to pass to the linker as -unexported_symbols_list
 	Unexported_symbols_list *string `android:"path,arch_variant"`
@@ -115,14 +116,23 @@
 	Llndk_stubs *string
 }
 
+// StaticProperties is a properties stanza to affect only attributes of the "static" variants of a
+// library module.
 type StaticProperties struct {
 	Static StaticOrSharedProperties `android:"arch_variant"`
 }
 
+// SharedProperties is a properties stanza to affect only attributes of the "shared" variants of a
+// library module.
 type SharedProperties struct {
 	Shared StaticOrSharedProperties `android:"arch_variant"`
 }
 
+// StaticOrSharedProperties is an embedded struct representing properties to affect attributes of
+// either only the "static" variants or only the "shared" variants of a library module. These override
+// the base properties of the same name.
+// Use `StaticProperties` or `SharedProperties`, depending on which variant is needed.
+// `StaticOrSharedProperties` exists only to avoid duplication.
 type StaticOrSharedProperties struct {
 	Srcs []string `android:"path,arch_variant"`
 
@@ -242,16 +252,23 @@
 	return module.Init()
 }
 
+// flagExporter is a separated portion of libraryDecorator pertaining to exported
+// include paths and flags. Keeping this dependency-related information separate
+// from the rest of library information is helpful in keeping data more structured
+// and explicit.
 type flagExporter struct {
 	Properties FlagExporterProperties
 
-	dirs       android.Paths
-	systemDirs android.Paths
-	flags      []string
+	dirs       android.Paths // Include directories to be included with -I
+	systemDirs android.Paths // System include directories to be included with -isystem
+	flags      []string      // Exported raw flags.
 	deps       android.Paths
 	headers    android.Paths
 }
 
+// exportedIncludes returns the effective include paths for this module and
+// any module that links against this module. This is obtained from
+// the export_include_dirs property in the appropriate target stanza.
 func (f *flagExporter) exportedIncludes(ctx ModuleContext) android.Paths {
 	// TODO(b/150902910): product variant must use Target.Product
 	if ctx.useVndk() && f.Properties.Target.Vendor.Override_export_include_dirs != nil {
@@ -261,25 +278,35 @@
 	}
 }
 
+// exportIncludes registers the include directories and system include directories to be exported
+// transitively to modules depending on this module.
 func (f *flagExporter) exportIncludes(ctx ModuleContext) {
 	f.dirs = append(f.dirs, f.exportedIncludes(ctx)...)
 	f.systemDirs = append(f.systemDirs, android.PathsForModuleSrc(ctx, f.Properties.Export_system_include_dirs)...)
 }
 
+// exportIncludesAsSystem registers the include directories and system include directories to be
+// exported transitively both as system include directories to modules depending on this module.
 func (f *flagExporter) exportIncludesAsSystem(ctx ModuleContext) {
 	// all dirs are force exported as system
 	f.systemDirs = append(f.systemDirs, f.exportedIncludes(ctx)...)
 	f.systemDirs = append(f.systemDirs, android.PathsForModuleSrc(ctx, f.Properties.Export_system_include_dirs)...)
 }
 
+// reexportDirs registers the given directories as include directories to be exported transitively
+// to modules depending on this module.
 func (f *flagExporter) reexportDirs(dirs ...android.Path) {
 	f.dirs = append(f.dirs, dirs...)
 }
 
+// reexportSystemDirs registers the given directories as system include directories
+// to be exported transitively to modules depending on this module.
 func (f *flagExporter) reexportSystemDirs(dirs ...android.Path) {
 	f.systemDirs = append(f.systemDirs, dirs...)
 }
 
+// reexportFlags registers the flags to be exported transitively to modules depending on this
+// module.
 func (f *flagExporter) reexportFlags(flags ...string) {
 	if android.PrefixInList(flags, "-I") || android.PrefixInList(flags, "-isystem") {
 		panic(fmt.Errorf("Exporting invalid flag %q: "+
@@ -457,6 +484,8 @@
 	return l.collectedSnapshotHeaders
 }
 
+// linkerProps returns the list of properties structs relevant for this library. (For example, if
+// the library is cc_shared_library, then static-library properties are omitted.)
 func (library *libraryDecorator) linkerProps() []interface{} {
 	var props []interface{}
 	props = append(props, library.baseLinker.linkerProps()...)
@@ -476,6 +505,9 @@
 	return props
 }
 
+// linkerFlags takes a Flags struct and augments it to contain linker flags that are defined by this
+// library, or that are implied by attributes of this library (such as whether this library is a
+// shared library).
 func (library *libraryDecorator) linkerFlags(ctx ModuleContext, flags Flags) Flags {
 	flags = library.baseLinker.linkerFlags(ctx, flags)
 
@@ -526,6 +558,9 @@
 	return flags
 }
 
+// compilerFlags takes a Flags and augments it to contain compile flags from global values,
+// per-target values, module type values, per-module Blueprints properties, extra flags from
+// `flags`, and generated sources from `deps`.
 func (library *libraryDecorator) compilerFlags(ctx ModuleContext, flags Flags, deps PathDeps) Flags {
 	exportIncludeDirs := library.flagExporter.exportedIncludes(ctx)
 	if len(exportIncludeDirs) > 0 {
@@ -727,6 +762,8 @@
 	return name + suffix
 }
 
+// getLibName returns the actual canonical name of the library (the name which
+// should be passed to the linker via linker flags).
 func (library *libraryDecorator) getLibName(ctx BaseModuleContext) string {
 	name := library.getLibNameHelper(ctx.baseModuleName(), ctx.useVndk())
 
@@ -1058,18 +1095,18 @@
 
 	stubs := ctx.GetDirectDepsWithTag(stubImplDepTag)
 	if len(stubs) > 0 {
-		var stubsInfo []SharedLibraryStubsInfo
+		var stubsInfo []SharedStubLibrary
 		for _, stub := range stubs {
 			stubInfo := ctx.OtherModuleProvider(stub, SharedLibraryInfoProvider).(SharedLibraryInfo)
 			flagInfo := ctx.OtherModuleProvider(stub, FlagExporterInfoProvider).(FlagExporterInfo)
-			stubsInfo = append(stubsInfo, SharedLibraryStubsInfo{
+			stubsInfo = append(stubsInfo, SharedStubLibrary{
 				Version:           moduleLibraryInterface(stub).stubsVersion(),
 				SharedLibraryInfo: stubInfo,
 				FlagExporterInfo:  flagInfo,
 			})
 		}
-		ctx.SetProvider(SharedLibraryImplementationStubsInfoProvider, SharedLibraryImplementationStubsInfo{
-			SharedLibraryStubsInfos: stubsInfo,
+		ctx.SetProvider(SharedLibraryStubsProvider, SharedLibraryStubsInfo{
+			SharedStubLibraries: stubsInfo,
 
 			IsLLNDK: ctx.isLlndk(ctx.Config()),
 		})
@@ -1158,9 +1195,15 @@
 	}
 }
 
+// link registers actions to link this library, and sets various fields
+// on this library to reflect information that should be exported up the build
+// tree (for example, exported flags and include paths).
 func (library *libraryDecorator) link(ctx ModuleContext,
 	flags Flags, deps PathDeps, objs Objects) android.Path {
 
+	// Linking this library consists of linking `deps.Objs` (.o files in dependencies
+	// of this library), together with `objs` (.o files created by compiling this
+	// library).
 	objs = deps.Objs.Copy().Append(objs)
 	var out android.Path
 	if library.static() || library.header() {
@@ -1169,6 +1212,7 @@
 		out = library.linkShared(ctx, flags, deps, objs)
 	}
 
+	// Export include paths and flags to be propagated up the tree.
 	library.exportIncludes(ctx)
 	library.reexportDirs(deps.ReexportedDirs...)
 	library.reexportSystemDirs(deps.ReexportedSystemDirs...)
@@ -1176,6 +1220,7 @@
 	library.reexportDeps(deps.ReexportedDeps...)
 	library.addExportedGeneratedHeaders(deps.ReexportedGeneratedHeaders...)
 
+	// Optionally export aidl headers.
 	if Bool(library.Properties.Aidl.Export_aidl_headers) {
 		if library.baseCompiler.hasSrcExt(".aidl") {
 			dir := android.PathForModuleGen(ctx, "aidl")
@@ -1187,6 +1232,7 @@
 		}
 	}
 
+	// Optionally export proto headers.
 	if Bool(library.Properties.Proto.Export_proto_headers) {
 		if library.baseCompiler.hasSrcExt(".proto") {
 			var includes android.Paths
@@ -1221,25 +1267,30 @@
 			}
 		}
 
+		// Add sysprop-related directories to the exported directories of this library.
 		library.reexportDirs(dir)
 		library.reexportDeps(library.baseCompiler.pathDeps...)
 		library.addExportedGeneratedHeaders(library.baseCompiler.pathDeps...)
 	}
 
+	// Add stub-related flags if this library is a stub library.
 	if library.buildStubs() && !library.skipAPIDefine {
 		library.reexportFlags("-D" + versioningMacroName(ctx.Module().(*Module).ImplementationModuleName(ctx)) + "=" + library.stubsVersion())
 	}
 
+	// Propagate a Provider containing information about exported flags, deps, and include paths.
 	library.flagExporter.setProvider(ctx)
 
 	return out
 }
 
+// buildStatic returns true if this library should be built as a static library.
 func (library *libraryDecorator) buildStatic() bool {
 	return library.MutatedProperties.BuildStatic &&
 		BoolDefault(library.StaticProperties.Static.Enabled, true)
 }
 
+// buildShared returns true if this library should be built as a shared library.
 func (library *libraryDecorator) buildShared() bool {
 	return library.MutatedProperties.BuildShared &&
 		BoolDefault(library.SharedProperties.Shared.Enabled, true)
@@ -1346,36 +1397,46 @@
 	return library.shared() || library.static()
 }
 
+// static returns true if this library is for a "static' variant.
 func (library *libraryDecorator) static() bool {
 	return library.MutatedProperties.VariantIsStatic
 }
 
+// shared returns true if this library is for a "shared' variant.
 func (library *libraryDecorator) shared() bool {
 	return library.MutatedProperties.VariantIsShared
 }
 
+// header returns true if this library is for a header-only variant.
 func (library *libraryDecorator) header() bool {
+	// Neither "static" nor "shared" implies this library is header-only.
 	return !library.static() && !library.shared()
 }
 
+// setStatic marks the library variant as "static".
 func (library *libraryDecorator) setStatic() {
 	library.MutatedProperties.VariantIsStatic = true
 	library.MutatedProperties.VariantIsShared = false
 }
 
+// setShared marks the library variant as "shared".
 func (library *libraryDecorator) setShared() {
 	library.MutatedProperties.VariantIsStatic = false
 	library.MutatedProperties.VariantIsShared = true
 }
 
+// BuildOnlyStatic disables building this library as a shared library.
 func (library *libraryDecorator) BuildOnlyStatic() {
 	library.MutatedProperties.BuildShared = false
 }
 
+// BuildOnlyShared disables building this library as a static library.
 func (library *libraryDecorator) BuildOnlyShared() {
 	library.MutatedProperties.BuildStatic = false
 }
 
+// HeaderOnly disables building this library as a shared or static library;
+// the library only exists to propagate header file dependencies up the build graph.
 func (library *libraryDecorator) HeaderOnly() {
 	library.MutatedProperties.BuildShared = false
 	library.MutatedProperties.BuildStatic = false
@@ -1458,6 +1519,17 @@
 
 var versioningMacroNamesListKey = android.NewOnceKey("versioningMacroNamesList")
 
+// versioningMacroNamesList returns a singleton map, where keys are "version macro names",
+// and values are the module name responsible for registering the version macro name.
+//
+// Version macros are used when building against stubs, to provide version information about
+// the stub. Only stub libraries should have an entry in this list.
+//
+// For example, when building against libFoo#ver, __LIBFOO_API__ macro is set to ver so
+// that headers from libFoo can be conditionally compiled (this may hide APIs
+// that are not available for the version).
+//
+// This map is used to ensure that there aren't conflicts between these version macro names.
 func versioningMacroNamesList(config android.Config) *map[string]string {
 	return config.Once(versioningMacroNamesListKey, func() interface{} {
 		m := make(map[string]string)
@@ -1469,12 +1541,17 @@
 // other characters are all converted to _
 var charsNotForMacro = regexp.MustCompile("[^a-zA-Z0-9_]+")
 
+// versioningMacroName returns the canonical version macro name for the given module.
 func versioningMacroName(moduleName string) string {
 	macroName := charsNotForMacro.ReplaceAllString(moduleName, "_")
 	macroName = strings.ToUpper(macroName)
 	return "__" + macroName + "_API__"
 }
 
+// NewLibrary builds and returns a new Module corresponding to a C++ library.
+// Individual module implementations which comprise a C++ library (or something like
+// a C++ library) should call this function, set some fields on the result, and
+// then call the Init function.
 func NewLibrary(hod android.HostOrDeviceSupported) (*Module, *libraryDecorator) {
 	module := newModule(hod, android.MultilibBoth)
 
@@ -1530,6 +1607,8 @@
 	}
 }
 
+// LinkageMutator adds "static" or "shared" variants for modules depending
+// on whether the module can be built as a static library or a shared library.
 func LinkageMutator(mctx android.BottomUpMutatorContext) {
 	cc_prebuilt := false
 	if m, ok := mctx.Module().(*Module); ok && m.linker != nil {
@@ -1607,6 +1686,9 @@
 	}
 }
 
+// normalizeVersions modifies `versions` in place, so that each raw version
+// string becomes its normalized canonical form.
+// Validates that the versions in `versions` are specified in least to greatest order.
 func normalizeVersions(ctx android.BaseModuleContext, versions []string) {
 	var previous android.ApiLevel
 	for i, v := range versions {
diff --git a/cc/linkable.go b/cc/linkable.go
index e5dc2b3..4efe2a7 100644
--- a/cc/linkable.go
+++ b/cc/linkable.go
@@ -6,6 +6,7 @@
 	"github.com/google/blueprint"
 )
 
+// LinkableInterface is an interface for a type of module that is linkable in a C++ library.
 type LinkableInterface interface {
 	android.Module
 
@@ -56,23 +57,30 @@
 }
 
 var (
+	// Dependency tag for crtbegin, an object file responsible for initialization.
 	CrtBeginDepTag = dependencyTag{name: "crtbegin"}
-	CrtEndDepTag   = dependencyTag{name: "crtend"}
+	// Dependency tag for crtend, an object file responsible for program termination.
+	CrtEndDepTag = dependencyTag{name: "crtend"}
+	// Dependency tag for coverage library.
 	CoverageDepTag = dependencyTag{name: "coverage"}
 )
 
+// SharedDepTag returns the dependency tag for any C++ shared libraries.
 func SharedDepTag() blueprint.DependencyTag {
 	return libraryDependencyTag{Kind: sharedLibraryDependency}
 }
 
+// StaticDepTag returns the dependency tag for any C++ static libraries.
 func StaticDepTag() blueprint.DependencyTag {
 	return libraryDependencyTag{Kind: staticLibraryDependency}
 }
 
+// HeaderDepTag returns the dependency tag for any C++ "header-only" libraries.
 func HeaderDepTag() blueprint.DependencyTag {
 	return libraryDependencyTag{Kind: headerLibraryDependency}
 }
 
+// SharedLibraryInfo is a provider to propagate information about a shared C++ library.
 type SharedLibraryInfo struct {
 	SharedLibrary           android.Path
 	UnstrippedSharedLibrary android.Path
@@ -85,22 +93,30 @@
 
 var SharedLibraryInfoProvider = blueprint.NewProvider(SharedLibraryInfo{})
 
-type SharedLibraryImplementationStubsInfo struct {
-	SharedLibraryStubsInfos []SharedLibraryStubsInfo
-
-	IsLLNDK bool
-}
-
-var SharedLibraryImplementationStubsInfoProvider = blueprint.NewProvider(SharedLibraryImplementationStubsInfo{})
-
-type SharedLibraryStubsInfo struct {
+// SharedStubLibrary is a struct containing information about a stub shared library.
+// Stub libraries are used for cross-APEX dependencies; when a library is to depend on a shared
+// library in another APEX, it must depend on the stub version of that library.
+type SharedStubLibrary struct {
+	// The version of the stub (corresponding to the stable version of the shared library being
+	// stubbed).
 	Version           string
 	SharedLibraryInfo SharedLibraryInfo
 	FlagExporterInfo  FlagExporterInfo
 }
 
-var SharedLibraryStubsInfoProvider = blueprint.NewProvider(SharedLibraryStubsInfo{})
+// SharedLibraryStubsInfo is a provider to propagate information about all shared library stubs
+// which are dependencies of a library.
+// Stub libraries are used for cross-APEX dependencies; when a library is to depend on a shared
+// library in another APEX, it must depend on the stub version of that library.
+type SharedLibraryStubsInfo struct {
+	SharedStubLibraries []SharedStubLibrary
 
+	IsLLNDK bool
+}
+
+var SharedLibraryStubsProvider = blueprint.NewProvider(SharedLibraryStubsInfo{})
+
+// StaticLibraryInfo is a provider to propagate information about a static C++ library.
 type StaticLibraryInfo struct {
 	StaticLibrary android.Path
 	Objects       Objects
@@ -114,10 +130,12 @@
 
 var StaticLibraryInfoProvider = blueprint.NewProvider(StaticLibraryInfo{})
 
+// FlagExporterInfo is a provider to propagate transitive library information
+// pertaining to exported include paths and flags.
 type FlagExporterInfo struct {
-	IncludeDirs       android.Paths
-	SystemIncludeDirs android.Paths
-	Flags             []string
+	IncludeDirs       android.Paths // Include directories to be included with -I
+	SystemIncludeDirs android.Paths // System include directories to be included with -isystem
+	Flags             []string      // Exported raw flags.
 	Deps              android.Paths
 	GeneratedHeaders  android.Paths
 }
diff --git a/cc/linker.go b/cc/linker.go
index 9d4a643..7bc4105 100644
--- a/cc/linker.go
+++ b/cc/linker.go
@@ -174,6 +174,15 @@
 			// variants.
 			Shared_libs []string
 		}
+		Apex struct {
+			// list of shared libs that should not be used to build the apex variant of
+			// the C/C++ module.
+			Exclude_shared_libs []string
+
+			// list of static libs that should not be used to build the apex ramdisk
+			// variant of the C/C++ module.
+			Exclude_static_libs []string
+		}
 	}
 
 	// make android::build:GetBuildNumber() available containing the build ID.
@@ -240,6 +249,16 @@
 	deps.StaticLibs = removeListFromList(deps.StaticLibs, linker.Properties.Exclude_static_libs)
 	deps.WholeStaticLibs = removeListFromList(deps.WholeStaticLibs, linker.Properties.Exclude_static_libs)
 
+	// Record the libraries that need to be excluded when building for APEX. Unlike other
+	// target.*.exclude_* properties, SharedLibs and StaticLibs are not modified here because
+	// this module hasn't yet passed the apexMutator. Therefore, we can't tell whether this is
+	// an apex variant of not. Record the exclude list in the deps struct for now. The info is
+	// used to mark the dependency tag when adding dependencies to the deps. Then inside
+	// GenerateAndroidBuildActions, the marked dependencies are ignored (i.e. not used) for APEX
+	// variants.
+	deps.ExcludeLibsForApex = append(deps.ExcludeLibsForApex, linker.Properties.Target.Apex.Exclude_shared_libs...)
+	deps.ExcludeLibsForApex = append(deps.ExcludeLibsForApex, linker.Properties.Target.Apex.Exclude_static_libs...)
+
 	if Bool(linker.Properties.Use_version_lib) {
 		deps.WholeStaticLibs = append(deps.WholeStaticLibs, "libbuildversion")
 	}
diff --git a/cc/snapshot_prebuilt.go b/cc/snapshot_prebuilt.go
new file mode 100644
index 0000000..b291bd0
--- /dev/null
+++ b/cc/snapshot_prebuilt.go
@@ -0,0 +1,844 @@
+// Copyright 2020 The Android Open Source Project
+//
+// 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
+
+// This file defines snapshot prebuilt modules, e.g. vendor snapshot and recovery snapshot. Such
+// snapshot modules will override original source modules with setting BOARD_VNDK_VERSION, with
+// snapshot mutators and snapshot information maps which are also defined in this file.
+
+import (
+	"strings"
+	"sync"
+
+	"android/soong/android"
+)
+
+// Defines the specifics of different images to which the snapshot process is applicable, e.g.,
+// vendor, recovery, ramdisk.
+type snapshotImage interface {
+	// Used to register callbacks with the build system.
+	init()
+
+	// Function that returns true if the module is included in this image.
+	// Using a function return instead of a value to prevent early
+	// evalution of a function that may be not be defined.
+	inImage(m *Module) func() bool
+
+	// Returns the value of the "available" property for a given module for
+	// and snapshot, e.g., "vendor_available", "recovery_available", etc.
+	// or nil if the property is not defined.
+	available(m *Module) *bool
+
+	// Returns true if a dir under source tree is an SoC-owned proprietary
+	// directory, such as device/, vendor/, etc.
+	//
+	// For a given snapshot (e.g., vendor, recovery, etc.) if
+	// isProprietaryPath(dir) returns true, then the module in dir will be
+	// built from sources.
+	isProprietaryPath(dir string) bool
+
+	// Whether to include VNDK in the snapshot for this image.
+	includeVndk() bool
+
+	// Whether a given module has been explicitly excluded from the
+	// snapshot, e.g., using the exclude_from_vendor_snapshot or
+	// exclude_from_recovery_snapshot properties.
+	excludeFromSnapshot(m *Module) bool
+}
+
+type vendorSnapshotImage struct{}
+type recoverySnapshotImage struct{}
+
+func (vendorSnapshotImage) init() {
+	android.RegisterSingletonType("vendor-snapshot", VendorSnapshotSingleton)
+	android.RegisterModuleType("vendor_snapshot_shared", VendorSnapshotSharedFactory)
+	android.RegisterModuleType("vendor_snapshot_static", VendorSnapshotStaticFactory)
+	android.RegisterModuleType("vendor_snapshot_header", VendorSnapshotHeaderFactory)
+	android.RegisterModuleType("vendor_snapshot_binary", VendorSnapshotBinaryFactory)
+	android.RegisterModuleType("vendor_snapshot_object", VendorSnapshotObjectFactory)
+}
+
+func (vendorSnapshotImage) inImage(m *Module) func() bool {
+	return m.inVendor
+}
+
+func (vendorSnapshotImage) available(m *Module) *bool {
+	return m.VendorProperties.Vendor_available
+}
+
+func (vendorSnapshotImage) isProprietaryPath(dir string) bool {
+	return isVendorProprietaryPath(dir)
+}
+
+// vendor snapshot includes static/header libraries with vndk: {enabled: true}.
+func (vendorSnapshotImage) includeVndk() bool {
+	return true
+}
+
+func (vendorSnapshotImage) excludeFromSnapshot(m *Module) bool {
+	return m.ExcludeFromVendorSnapshot()
+}
+
+func (recoverySnapshotImage) init() {
+	android.RegisterSingletonType("recovery-snapshot", RecoverySnapshotSingleton)
+	android.RegisterModuleType("recovery_snapshot_shared", RecoverySnapshotSharedFactory)
+	android.RegisterModuleType("recovery_snapshot_static", RecoverySnapshotStaticFactory)
+	android.RegisterModuleType("recovery_snapshot_header", RecoverySnapshotHeaderFactory)
+	android.RegisterModuleType("recovery_snapshot_binary", RecoverySnapshotBinaryFactory)
+	android.RegisterModuleType("recovery_snapshot_object", RecoverySnapshotObjectFactory)
+}
+
+func (recoverySnapshotImage) inImage(m *Module) func() bool {
+	return m.InRecovery
+}
+
+func (recoverySnapshotImage) available(m *Module) *bool {
+	return m.Properties.Recovery_available
+}
+
+func (recoverySnapshotImage) isProprietaryPath(dir string) bool {
+	return isRecoveryProprietaryPath(dir)
+}
+
+// recovery snapshot does NOT treat vndk specially.
+func (recoverySnapshotImage) includeVndk() bool {
+	return false
+}
+
+func (recoverySnapshotImage) excludeFromSnapshot(m *Module) bool {
+	return m.ExcludeFromRecoverySnapshot()
+}
+
+var vendorSnapshotImageSingleton vendorSnapshotImage
+var recoverySnapshotImageSingleton recoverySnapshotImage
+
+func init() {
+	vendorSnapshotImageSingleton.init()
+	recoverySnapshotImageSingleton.init()
+}
+
+const (
+	vendorSnapshotHeaderSuffix = ".vendor_header."
+	vendorSnapshotSharedSuffix = ".vendor_shared."
+	vendorSnapshotStaticSuffix = ".vendor_static."
+	vendorSnapshotBinarySuffix = ".vendor_binary."
+	vendorSnapshotObjectSuffix = ".vendor_object."
+)
+
+const (
+	recoverySnapshotHeaderSuffix = ".recovery_header."
+	recoverySnapshotSharedSuffix = ".recovery_shared."
+	recoverySnapshotStaticSuffix = ".recovery_static."
+	recoverySnapshotBinarySuffix = ".recovery_binary."
+	recoverySnapshotObjectSuffix = ".recovery_object."
+)
+
+var (
+	vendorSnapshotsLock         sync.Mutex
+	vendorSuffixModulesKey      = android.NewOnceKey("vendorSuffixModules")
+	vendorSnapshotHeaderLibsKey = android.NewOnceKey("vendorSnapshotHeaderLibs")
+	vendorSnapshotStaticLibsKey = android.NewOnceKey("vendorSnapshotStaticLibs")
+	vendorSnapshotSharedLibsKey = android.NewOnceKey("vendorSnapshotSharedLibs")
+	vendorSnapshotBinariesKey   = android.NewOnceKey("vendorSnapshotBinaries")
+	vendorSnapshotObjectsKey    = android.NewOnceKey("vendorSnapshotObjects")
+)
+
+// vendorSuffixModules holds names of modules whose vendor variants should have the vendor suffix.
+// This is determined by source modules, and then this will be used when exporting snapshot modules
+// to Makefile.
+//
+// For example, if libbase has "vendor_available: true", the name of core variant will be "libbase"
+// while the name of vendor variant will be "libbase.vendor". In such cases, the vendor snapshot of
+// "libbase" should be exported with the name "libbase.vendor".
+//
+// Refer to VendorSnapshotSourceMutator and makeLibName which use this.
+func vendorSuffixModules(config android.Config) map[string]bool {
+	return config.Once(vendorSuffixModulesKey, func() interface{} {
+		return make(map[string]bool)
+	}).(map[string]bool)
+}
+
+// these are vendor snapshot maps holding names of vendor snapshot modules
+func vendorSnapshotHeaderLibs(config android.Config) *snapshotMap {
+	return config.Once(vendorSnapshotHeaderLibsKey, func() interface{} {
+		return newSnapshotMap()
+	}).(*snapshotMap)
+}
+
+func vendorSnapshotSharedLibs(config android.Config) *snapshotMap {
+	return config.Once(vendorSnapshotSharedLibsKey, func() interface{} {
+		return newSnapshotMap()
+	}).(*snapshotMap)
+}
+
+func vendorSnapshotStaticLibs(config android.Config) *snapshotMap {
+	return config.Once(vendorSnapshotStaticLibsKey, func() interface{} {
+		return newSnapshotMap()
+	}).(*snapshotMap)
+}
+
+func vendorSnapshotBinaries(config android.Config) *snapshotMap {
+	return config.Once(vendorSnapshotBinariesKey, func() interface{} {
+		return newSnapshotMap()
+	}).(*snapshotMap)
+}
+
+func vendorSnapshotObjects(config android.Config) *snapshotMap {
+	return config.Once(vendorSnapshotObjectsKey, func() interface{} {
+		return newSnapshotMap()
+	}).(*snapshotMap)
+}
+
+type baseSnapshotDecoratorProperties struct {
+	// snapshot version.
+	Version string
+
+	// Target arch name of the snapshot (e.g. 'arm64' for variant 'aosp_arm64')
+	Target_arch string
+}
+
+// baseSnapshotDecorator provides common basic functions for all snapshot modules, such as snapshot
+// version, snapshot arch, etc. It also adds a special suffix to Soong module name, so it doesn't
+// collide with source modules. e.g. the following example module,
+//
+// vendor_snapshot_static {
+//     name: "libbase",
+//     arch: "arm64",
+//     version: 30,
+//     ...
+// }
+//
+// will be seen as "libbase.vendor_static.30.arm64" by Soong.
+type baseSnapshotDecorator struct {
+	baseProperties baseSnapshotDecoratorProperties
+	moduleSuffix   string
+}
+
+func (p *baseSnapshotDecorator) Name(name string) string {
+	return name + p.NameSuffix()
+}
+
+func (p *baseSnapshotDecorator) NameSuffix() string {
+	versionSuffix := p.version()
+	if p.arch() != "" {
+		versionSuffix += "." + p.arch()
+	}
+
+	return p.moduleSuffix + versionSuffix
+}
+
+func (p *baseSnapshotDecorator) version() string {
+	return p.baseProperties.Version
+}
+
+func (p *baseSnapshotDecorator) arch() string {
+	return p.baseProperties.Target_arch
+}
+
+func (p *baseSnapshotDecorator) isSnapshotPrebuilt() bool {
+	return true
+}
+
+// Call this with a module suffix after creating a snapshot module, such as
+// vendorSnapshotSharedSuffix, recoverySnapshotBinarySuffix, etc.
+func (p *baseSnapshotDecorator) init(m *Module, suffix string) {
+	p.moduleSuffix = suffix
+	m.AddProperties(&p.baseProperties)
+	android.AddLoadHook(m, func(ctx android.LoadHookContext) {
+		vendorSnapshotLoadHook(ctx, p)
+	})
+}
+
+// vendorSnapshotLoadHook disables snapshots if it's not BOARD_VNDK_VERSION.
+// As vendor snapshot is only for vendor, such modules won't be used at all.
+func vendorSnapshotLoadHook(ctx android.LoadHookContext, p *baseSnapshotDecorator) {
+	if p.version() != ctx.DeviceConfig().VndkVersion() {
+		ctx.Module().Disable()
+		return
+	}
+}
+
+//
+// Module definitions for snapshots of libraries (shared, static, header).
+//
+// Modules (vendor|recovery)_snapshot_(shared|static|header) are defined here. Shared libraries and
+// static libraries have their prebuilt library files (.so for shared, .a for static) as their src,
+// which can be installed or linked against. Also they export flags needed when linked, such as
+// include directories, c flags, sanitize dependency information, etc.
+//
+// These modules are auto-generated by development/vendor_snapshot/update.py.
+type snapshotLibraryProperties struct {
+	// Prebuilt file for each arch.
+	Src *string `android:"arch_variant"`
+
+	// list of directories that will be added to the include path (using -I).
+	Export_include_dirs []string `android:"arch_variant"`
+
+	// list of directories that will be added to the system path (using -isystem).
+	Export_system_include_dirs []string `android:"arch_variant"`
+
+	// list of flags that will be used for any module that links against this module.
+	Export_flags []string `android:"arch_variant"`
+
+	// Whether this prebuilt needs to depend on sanitize ubsan runtime or not.
+	Sanitize_ubsan_dep *bool `android:"arch_variant"`
+
+	// Whether this prebuilt needs to depend on sanitize minimal runtime or not.
+	Sanitize_minimal_dep *bool `android:"arch_variant"`
+}
+
+type snapshotSanitizer interface {
+	isSanitizerEnabled(t sanitizerType) bool
+	setSanitizerVariation(t sanitizerType, enabled bool)
+}
+
+type snapshotLibraryDecorator struct {
+	baseSnapshotDecorator
+	*libraryDecorator
+	properties          snapshotLibraryProperties
+	sanitizerProperties struct {
+		CfiEnabled bool `blueprint:"mutated"`
+
+		// Library flags for cfi variant.
+		Cfi snapshotLibraryProperties `android:"arch_variant"`
+	}
+	androidMkVendorSuffix bool
+}
+
+func (p *snapshotLibraryDecorator) linkerFlags(ctx ModuleContext, flags Flags) Flags {
+	p.libraryDecorator.libName = strings.TrimSuffix(ctx.ModuleName(), p.NameSuffix())
+	return p.libraryDecorator.linkerFlags(ctx, flags)
+}
+
+func (p *snapshotLibraryDecorator) matchesWithDevice(config android.DeviceConfig) bool {
+	arches := config.Arches()
+	if len(arches) == 0 || arches[0].ArchType.String() != p.arch() {
+		return false
+	}
+	if !p.header() && p.properties.Src == nil {
+		return false
+	}
+	return true
+}
+
+// cc modules' link functions are to link compiled objects into final binaries.
+// As snapshots are prebuilts, this just returns the prebuilt binary after doing things which are
+// done by normal library decorator, e.g. exporting flags.
+func (p *snapshotLibraryDecorator) link(ctx ModuleContext, flags Flags, deps PathDeps, objs Objects) android.Path {
+	m := ctx.Module().(*Module)
+	p.androidMkVendorSuffix = vendorSuffixModules(ctx.Config())[m.BaseModuleName()]
+
+	if p.header() {
+		return p.libraryDecorator.link(ctx, flags, deps, objs)
+	}
+
+	if p.sanitizerProperties.CfiEnabled {
+		p.properties = p.sanitizerProperties.Cfi
+	}
+
+	if !p.matchesWithDevice(ctx.DeviceConfig()) {
+		return nil
+	}
+
+	p.libraryDecorator.reexportDirs(android.PathsForModuleSrc(ctx, p.properties.Export_include_dirs)...)
+	p.libraryDecorator.reexportSystemDirs(android.PathsForModuleSrc(ctx, p.properties.Export_system_include_dirs)...)
+	p.libraryDecorator.reexportFlags(p.properties.Export_flags...)
+
+	in := android.PathForModuleSrc(ctx, *p.properties.Src)
+	p.unstrippedOutputFile = in
+
+	if p.shared() {
+		libName := in.Base()
+		builderFlags := flagsToBuilderFlags(flags)
+
+		// Optimize out relinking against shared libraries whose interface hasn't changed by
+		// depending on a table of contents file instead of the library itself.
+		tocFile := android.PathForModuleOut(ctx, libName+".toc")
+		p.tocFile = android.OptionalPathForPath(tocFile)
+		transformSharedObjectToToc(ctx, in, tocFile, builderFlags)
+
+		ctx.SetProvider(SharedLibraryInfoProvider, SharedLibraryInfo{
+			SharedLibrary:           in,
+			UnstrippedSharedLibrary: p.unstrippedOutputFile,
+
+			TableOfContents: p.tocFile,
+		})
+	}
+
+	if p.static() {
+		depSet := android.NewDepSetBuilder(android.TOPOLOGICAL).Direct(in).Build()
+		ctx.SetProvider(StaticLibraryInfoProvider, StaticLibraryInfo{
+			StaticLibrary: in,
+
+			TransitiveStaticLibrariesForOrdering: depSet,
+		})
+	}
+
+	p.libraryDecorator.flagExporter.setProvider(ctx)
+
+	return in
+}
+
+func (p *snapshotLibraryDecorator) install(ctx ModuleContext, file android.Path) {
+	if p.matchesWithDevice(ctx.DeviceConfig()) && (p.shared() || p.static()) {
+		p.baseInstaller.install(ctx, file)
+	}
+}
+
+func (p *snapshotLibraryDecorator) nativeCoverage() bool {
+	return false
+}
+
+func (p *snapshotLibraryDecorator) isSanitizerEnabled(t sanitizerType) bool {
+	switch t {
+	case cfi:
+		return p.sanitizerProperties.Cfi.Src != nil
+	default:
+		return false
+	}
+}
+
+func (p *snapshotLibraryDecorator) setSanitizerVariation(t sanitizerType, enabled bool) {
+	if !enabled {
+		return
+	}
+	switch t {
+	case cfi:
+		p.sanitizerProperties.CfiEnabled = true
+	default:
+		return
+	}
+}
+
+func snapshotLibraryFactory(suffix string) (*Module, *snapshotLibraryDecorator) {
+	module, library := NewLibrary(android.DeviceSupported)
+
+	module.stl = nil
+	module.sanitize = nil
+	library.disableStripping()
+
+	prebuilt := &snapshotLibraryDecorator{
+		libraryDecorator: library,
+	}
+
+	prebuilt.baseLinker.Properties.No_libcrt = BoolPtr(true)
+	prebuilt.baseLinker.Properties.Nocrt = BoolPtr(true)
+
+	// Prevent default system libs (libc, libm, and libdl) from being linked
+	if prebuilt.baseLinker.Properties.System_shared_libs == nil {
+		prebuilt.baseLinker.Properties.System_shared_libs = []string{}
+	}
+
+	module.compiler = nil
+	module.linker = prebuilt
+	module.installer = prebuilt
+
+	prebuilt.init(module, suffix)
+	module.AddProperties(
+		&prebuilt.properties,
+		&prebuilt.sanitizerProperties,
+	)
+
+	return module, prebuilt
+}
+
+// vendor_snapshot_shared is a special prebuilt shared library which is auto-generated by
+// development/vendor_snapshot/update.py. As a part of vendor snapshot, vendor_snapshot_shared
+// overrides the vendor variant of the cc shared library with the same name, if BOARD_VNDK_VERSION
+// is set.
+func VendorSnapshotSharedFactory() android.Module {
+	module, prebuilt := snapshotLibraryFactory(vendorSnapshotSharedSuffix)
+	prebuilt.libraryDecorator.BuildOnlyShared()
+	return module.Init()
+}
+
+// recovery_snapshot_shared is a special prebuilt shared library which is auto-generated by
+// development/vendor_snapshot/update.py. As a part of recovery snapshot, recovery_snapshot_shared
+// overrides the recovery variant of the cc shared library with the same name, if BOARD_VNDK_VERSION
+// is set.
+func RecoverySnapshotSharedFactory() android.Module {
+	module, prebuilt := snapshotLibraryFactory(recoverySnapshotSharedSuffix)
+	prebuilt.libraryDecorator.BuildOnlyShared()
+	return module.Init()
+}
+
+// vendor_snapshot_static is a special prebuilt static library which is auto-generated by
+// development/vendor_snapshot/update.py. As a part of vendor snapshot, vendor_snapshot_static
+// overrides the vendor variant of the cc static library with the same name, if BOARD_VNDK_VERSION
+// is set.
+func VendorSnapshotStaticFactory() android.Module {
+	module, prebuilt := snapshotLibraryFactory(vendorSnapshotStaticSuffix)
+	prebuilt.libraryDecorator.BuildOnlyStatic()
+	return module.Init()
+}
+
+// recovery_snapshot_static is a special prebuilt static library which is auto-generated by
+// development/vendor_snapshot/update.py. As a part of recovery snapshot, recovery_snapshot_static
+// overrides the recovery variant of the cc static library with the same name, if BOARD_VNDK_VERSION
+// is set.
+func RecoverySnapshotStaticFactory() android.Module {
+	module, prebuilt := snapshotLibraryFactory(recoverySnapshotStaticSuffix)
+	prebuilt.libraryDecorator.BuildOnlyStatic()
+	return module.Init()
+}
+
+// vendor_snapshot_header is a special header library which is auto-generated by
+// development/vendor_snapshot/update.py. As a part of vendor snapshot, vendor_snapshot_header
+// overrides the vendor variant of the cc header library with the same name, if BOARD_VNDK_VERSION
+// is set.
+func VendorSnapshotHeaderFactory() android.Module {
+	module, prebuilt := snapshotLibraryFactory(vendorSnapshotHeaderSuffix)
+	prebuilt.libraryDecorator.HeaderOnly()
+	return module.Init()
+}
+
+// recovery_snapshot_header is a special header library which is auto-generated by
+// development/vendor_snapshot/update.py. As a part of recovery snapshot, recovery_snapshot_header
+// overrides the recovery variant of the cc header library with the same name, if BOARD_VNDK_VERSION
+// is set.
+func RecoverySnapshotHeaderFactory() android.Module {
+	module, prebuilt := snapshotLibraryFactory(recoverySnapshotHeaderSuffix)
+	prebuilt.libraryDecorator.HeaderOnly()
+	return module.Init()
+}
+
+var _ snapshotSanitizer = (*snapshotLibraryDecorator)(nil)
+
+//
+// Module definitions for snapshots of executable binaries.
+//
+// Modules (vendor|recovery)_snapshot_binary are defined here. They have their prebuilt executable
+// binaries (e.g. toybox, sh) as their src, which can be installed.
+//
+// These modules are auto-generated by development/vendor_snapshot/update.py.
+type snapshotBinaryProperties struct {
+	// Prebuilt file for each arch.
+	Src *string `android:"arch_variant"`
+}
+
+type snapshotBinaryDecorator struct {
+	baseSnapshotDecorator
+	*binaryDecorator
+	properties            snapshotBinaryProperties
+	androidMkVendorSuffix bool
+}
+
+func (p *snapshotBinaryDecorator) matchesWithDevice(config android.DeviceConfig) bool {
+	if config.DeviceArch() != p.arch() {
+		return false
+	}
+	if p.properties.Src == nil {
+		return false
+	}
+	return true
+}
+
+// cc modules' link functions are to link compiled objects into final binaries.
+// As snapshots are prebuilts, this just returns the prebuilt binary
+func (p *snapshotBinaryDecorator) link(ctx ModuleContext, flags Flags, deps PathDeps, objs Objects) android.Path {
+	if !p.matchesWithDevice(ctx.DeviceConfig()) {
+		return nil
+	}
+
+	in := android.PathForModuleSrc(ctx, *p.properties.Src)
+	p.unstrippedOutputFile = in
+	binName := in.Base()
+
+	m := ctx.Module().(*Module)
+	p.androidMkVendorSuffix = vendorSuffixModules(ctx.Config())[m.BaseModuleName()]
+
+	// use cpExecutable to make it executable
+	outputFile := android.PathForModuleOut(ctx, binName)
+	ctx.Build(pctx, android.BuildParams{
+		Rule:        android.CpExecutable,
+		Description: "prebuilt",
+		Output:      outputFile,
+		Input:       in,
+	})
+
+	return outputFile
+}
+
+func (p *snapshotBinaryDecorator) nativeCoverage() bool {
+	return false
+}
+
+// vendor_snapshot_binary is a special prebuilt executable binary which is auto-generated by
+// development/vendor_snapshot/update.py. As a part of vendor snapshot, vendor_snapshot_binary
+// overrides the vendor variant of the cc binary with the same name, if BOARD_VNDK_VERSION is set.
+func VendorSnapshotBinaryFactory() android.Module {
+	return snapshotBinaryFactory(vendorSnapshotBinarySuffix)
+}
+
+// recovery_snapshot_binary is a special prebuilt executable binary which is auto-generated by
+// development/vendor_snapshot/update.py. As a part of recovery snapshot, recovery_snapshot_binary
+// overrides the recovery variant of the cc binary with the same name, if BOARD_VNDK_VERSION is set.
+func RecoverySnapshotBinaryFactory() android.Module {
+	return snapshotBinaryFactory(recoverySnapshotBinarySuffix)
+}
+
+func snapshotBinaryFactory(suffix string) android.Module {
+	module, binary := NewBinary(android.DeviceSupported)
+	binary.baseLinker.Properties.No_libcrt = BoolPtr(true)
+	binary.baseLinker.Properties.Nocrt = BoolPtr(true)
+
+	// Prevent default system libs (libc, libm, and libdl) from being linked
+	if binary.baseLinker.Properties.System_shared_libs == nil {
+		binary.baseLinker.Properties.System_shared_libs = []string{}
+	}
+
+	prebuilt := &snapshotBinaryDecorator{
+		binaryDecorator: binary,
+	}
+
+	module.compiler = nil
+	module.sanitize = nil
+	module.stl = nil
+	module.linker = prebuilt
+
+	prebuilt.init(module, suffix)
+	module.AddProperties(&prebuilt.properties)
+	return module.Init()
+}
+
+//
+// Module definitions for snapshots of object files (*.o).
+//
+// Modules (vendor|recovery)_snapshot_object are defined here. They have their prebuilt object
+// files (*.o) as their src.
+//
+// These modules are auto-generated by development/vendor_snapshot/update.py.
+type vendorSnapshotObjectProperties struct {
+	// Prebuilt file for each arch.
+	Src *string `android:"arch_variant"`
+}
+
+type snapshotObjectLinker struct {
+	baseSnapshotDecorator
+	objectLinker
+	properties            vendorSnapshotObjectProperties
+	androidMkVendorSuffix bool
+}
+
+func (p *snapshotObjectLinker) matchesWithDevice(config android.DeviceConfig) bool {
+	if config.DeviceArch() != p.arch() {
+		return false
+	}
+	if p.properties.Src == nil {
+		return false
+	}
+	return true
+}
+
+// cc modules' link functions are to link compiled objects into final binaries.
+// As snapshots are prebuilts, this just returns the prebuilt binary
+func (p *snapshotObjectLinker) link(ctx ModuleContext, flags Flags, deps PathDeps, objs Objects) android.Path {
+	if !p.matchesWithDevice(ctx.DeviceConfig()) {
+		return nil
+	}
+
+	m := ctx.Module().(*Module)
+	p.androidMkVendorSuffix = vendorSuffixModules(ctx.Config())[m.BaseModuleName()]
+
+	return android.PathForModuleSrc(ctx, *p.properties.Src)
+}
+
+func (p *snapshotObjectLinker) nativeCoverage() bool {
+	return false
+}
+
+// vendor_snapshot_object is a special prebuilt compiled object file which is auto-generated by
+// development/vendor_snapshot/update.py. As a part of vendor snapshot, vendor_snapshot_object
+// overrides the vendor variant of the cc object with the same name, if BOARD_VNDK_VERSION is set.
+func VendorSnapshotObjectFactory() android.Module {
+	module := newObject()
+
+	prebuilt := &snapshotObjectLinker{
+		objectLinker: objectLinker{
+			baseLinker: NewBaseLinker(nil),
+		},
+	}
+	module.linker = prebuilt
+
+	prebuilt.init(module, vendorSnapshotObjectSuffix)
+	module.AddProperties(&prebuilt.properties)
+	return module.Init()
+}
+
+// recovery_snapshot_object is a special prebuilt compiled object file which is auto-generated by
+// development/vendor_snapshot/update.py. As a part of recovery snapshot, recovery_snapshot_object
+// overrides the recovery variant of the cc object with the same name, if BOARD_VNDK_VERSION is set.
+func RecoverySnapshotObjectFactory() android.Module {
+	module := newObject()
+
+	prebuilt := &snapshotObjectLinker{
+		objectLinker: objectLinker{
+			baseLinker: NewBaseLinker(nil),
+		},
+	}
+	module.linker = prebuilt
+
+	prebuilt.init(module, recoverySnapshotObjectSuffix)
+	module.AddProperties(&prebuilt.properties)
+	return module.Init()
+}
+
+type snapshotInterface interface {
+	matchesWithDevice(config android.DeviceConfig) bool
+}
+
+var _ snapshotInterface = (*vndkPrebuiltLibraryDecorator)(nil)
+var _ snapshotInterface = (*snapshotLibraryDecorator)(nil)
+var _ snapshotInterface = (*snapshotBinaryDecorator)(nil)
+var _ snapshotInterface = (*snapshotObjectLinker)(nil)
+
+//
+// Mutators that helps vendor snapshot modules override source modules.
+//
+
+// VendorSnapshotMutator gathers all snapshots for vendor, and disable all snapshots which don't
+// match with device, e.g.
+//   - snapshot version is different with BOARD_VNDK_VERSION
+//   - snapshot arch is different with device's arch (e.g. arm vs x86)
+//
+// This also handles vndk_prebuilt_shared, except for they won't be disabled in any cases, given
+// that any versions of VNDK might be packed into vndk APEX.
+//
+// TODO(b/145966707): remove mutator and utilize android.Prebuilt to override source modules
+func VendorSnapshotMutator(ctx android.BottomUpMutatorContext) {
+	vndkVersion := ctx.DeviceConfig().VndkVersion()
+	// don't need snapshot if current
+	if vndkVersion == "current" || vndkVersion == "" {
+		return
+	}
+
+	module, ok := ctx.Module().(*Module)
+	if !ok || !module.Enabled() || module.VndkVersion() != vndkVersion {
+		return
+	}
+
+	if !module.isSnapshotPrebuilt() {
+		return
+	}
+
+	// isSnapshotPrebuilt ensures snapshotInterface
+	if !module.linker.(snapshotInterface).matchesWithDevice(ctx.DeviceConfig()) {
+		// Disable unnecessary snapshot module, but do not disable
+		// vndk_prebuilt_shared because they might be packed into vndk APEX
+		if !module.IsVndk() {
+			module.Disable()
+		}
+		return
+	}
+
+	var snapshotMap *snapshotMap
+
+	if lib, ok := module.linker.(libraryInterface); ok {
+		if lib.static() {
+			snapshotMap = vendorSnapshotStaticLibs(ctx.Config())
+		} else if lib.shared() {
+			snapshotMap = vendorSnapshotSharedLibs(ctx.Config())
+		} else {
+			// header
+			snapshotMap = vendorSnapshotHeaderLibs(ctx.Config())
+		}
+	} else if _, ok := module.linker.(*snapshotBinaryDecorator); ok {
+		snapshotMap = vendorSnapshotBinaries(ctx.Config())
+	} else if _, ok := module.linker.(*snapshotObjectLinker); ok {
+		snapshotMap = vendorSnapshotObjects(ctx.Config())
+	} else {
+		return
+	}
+
+	vendorSnapshotsLock.Lock()
+	defer vendorSnapshotsLock.Unlock()
+	snapshotMap.add(module.BaseModuleName(), ctx.Arch().ArchType, ctx.ModuleName())
+}
+
+// VendorSnapshotSourceMutator disables source modules which have corresponding snapshots.
+func VendorSnapshotSourceMutator(ctx android.BottomUpMutatorContext) {
+	if !ctx.Device() {
+		return
+	}
+
+	vndkVersion := ctx.DeviceConfig().VndkVersion()
+	// don't need snapshot if current
+	if vndkVersion == "current" || vndkVersion == "" {
+		return
+	}
+
+	module, ok := ctx.Module().(*Module)
+	if !ok {
+		return
+	}
+
+	// vendor suffix should be added to snapshots if the source module isn't vendor: true.
+	if !module.SocSpecific() {
+		// But we can't just check SocSpecific() since we already passed the image mutator.
+		// Check ramdisk and recovery to see if we are real "vendor: true" module.
+		ramdisk_available := module.InRamdisk() && !module.OnlyInRamdisk()
+		vendor_ramdisk_available := module.InVendorRamdisk() && !module.OnlyInVendorRamdisk()
+		recovery_available := module.InRecovery() && !module.OnlyInRecovery()
+
+		if !ramdisk_available && !recovery_available && !vendor_ramdisk_available {
+			vendorSnapshotsLock.Lock()
+			defer vendorSnapshotsLock.Unlock()
+
+			vendorSuffixModules(ctx.Config())[ctx.ModuleName()] = true
+		}
+	}
+
+	if module.isSnapshotPrebuilt() || module.VndkVersion() != ctx.DeviceConfig().VndkVersion() {
+		// only non-snapshot modules with BOARD_VNDK_VERSION
+		return
+	}
+
+	// .. and also filter out llndk library
+	if module.isLlndk(ctx.Config()) {
+		return
+	}
+
+	var snapshotMap *snapshotMap
+
+	if lib, ok := module.linker.(libraryInterface); ok {
+		if lib.static() {
+			snapshotMap = vendorSnapshotStaticLibs(ctx.Config())
+		} else if lib.shared() {
+			snapshotMap = vendorSnapshotSharedLibs(ctx.Config())
+		} else {
+			// header
+			snapshotMap = vendorSnapshotHeaderLibs(ctx.Config())
+		}
+	} else if module.binary() {
+		snapshotMap = vendorSnapshotBinaries(ctx.Config())
+	} else if module.object() {
+		snapshotMap = vendorSnapshotObjects(ctx.Config())
+	} else {
+		return
+	}
+
+	if _, ok := snapshotMap.get(ctx.ModuleName(), ctx.Arch().ArchType); !ok {
+		// Corresponding snapshot doesn't exist
+		return
+	}
+
+	// Disables source modules if corresponding snapshot exists.
+	if lib, ok := module.linker.(libraryInterface); ok && lib.buildStatic() && lib.buildShared() {
+		// But do not disable because the shared variant depends on the static variant.
+		module.SkipInstall()
+		module.Properties.HideFromMake = true
+	} else {
+		module.Disable()
+	}
+}
diff --git a/cc/snapshot_utils.go b/cc/snapshot_utils.go
index a3d52e6..e841a54 100644
--- a/cc/snapshot_utils.go
+++ b/cc/snapshot_utils.go
@@ -13,6 +13,8 @@
 // limitations under the License.
 package cc
 
+// This file contains utility types and functions for VNDK / vendor snapshot.
+
 import (
 	"android/soong/android"
 )
@@ -21,15 +23,24 @@
 	headerExts = []string{".h", ".hh", ".hpp", ".hxx", ".h++", ".inl", ".inc", ".ipp", ".h.generic"}
 )
 
+// snapshotLibraryInterface is an interface for libraries captured to VNDK / vendor snapshots.
 type snapshotLibraryInterface interface {
 	libraryInterface
+
+	// collectHeadersForSnapshot is called in GenerateAndroidBuildActions for snapshot aware
+	// modules (See isSnapshotAware below).
+	// This function should gather all headers needed for snapshot.
 	collectHeadersForSnapshot(ctx android.ModuleContext)
+
+	// snapshotHeaders should return collected headers by collectHeadersForSnapshot.
+	// Calling snapshotHeaders before collectHeadersForSnapshot is an error.
 	snapshotHeaders() android.Paths
 }
 
 var _ snapshotLibraryInterface = (*prebuiltLibraryLinker)(nil)
 var _ snapshotLibraryInterface = (*libraryDecorator)(nil)
 
+// snapshotMap is a helper wrapper to a map from base module name to snapshot module name.
 type snapshotMap struct {
 	snapshots map[string]string
 }
@@ -57,43 +68,14 @@
 	return snapshot, found
 }
 
-func isSnapshotAware(ctx android.ModuleContext, m *Module, apexInfo android.ApexInfo) bool {
-	if _, _, ok := isVndkSnapshotLibrary(ctx.DeviceConfig(), m, apexInfo); ok {
+// shouldCollectHeadersForSnapshot determines if the module is a possible candidate for snapshot.
+// If it's true, collectHeadersForSnapshot will be called in GenerateAndroidBuildActions.
+func shouldCollectHeadersForSnapshot(ctx android.ModuleContext, m *Module, apexInfo android.ApexInfo) bool {
+	if _, _, ok := isVndkSnapshotAware(ctx.DeviceConfig(), m, apexInfo); ok {
 		return ctx.Config().VndkSnapshotBuildArtifacts()
-	} else if isVendorSnapshotModule(m, isVendorProprietaryPath(ctx.ModuleDir()), apexInfo) ||
-		isRecoverySnapshotModule(m, isVendorProprietaryPath(ctx.ModuleDir()), apexInfo) {
+	} else if isVendorSnapshotAware(m, isVendorProprietaryPath(ctx.ModuleDir()), apexInfo) ||
+		isRecoverySnapshotAware(m, isRecoveryProprietaryPath(ctx.ModuleDir()), apexInfo) {
 		return true
 	}
 	return false
 }
-
-func copyFile(ctx android.SingletonContext, path android.Path, out string) android.OutputPath {
-	outPath := android.PathForOutput(ctx, out)
-	ctx.Build(pctx, android.BuildParams{
-		Rule:        android.Cp,
-		Input:       path,
-		Output:      outPath,
-		Description: "Cp " + out,
-		Args: map[string]string{
-			"cpFlags": "-f -L",
-		},
-	})
-	return outPath
-}
-
-func combineNotices(ctx android.SingletonContext, paths android.Paths, out string) android.OutputPath {
-	outPath := android.PathForOutput(ctx, out)
-	ctx.Build(pctx, android.BuildParams{
-		Rule:        android.Cat,
-		Inputs:      paths,
-		Output:      outPath,
-		Description: "combine notices for " + out,
-	})
-	return outPath
-}
-
-func writeStringToFile(ctx android.SingletonContext, content, out string) android.OutputPath {
-	outPath := android.PathForOutput(ctx, out)
-	android.WriteFileRule(ctx, outPath, content)
-	return outPath
-}
diff --git a/cc/test.go b/cc/test.go
index 3772691..a9be6f9 100644
--- a/cc/test.go
+++ b/cc/test.go
@@ -29,11 +29,6 @@
 
 	// if set, use the isolated gtest runner. Defaults to false.
 	Isolated *bool
-
-	// List of APEXes that this module tests. The module has access to
-	// the private part of the listed APEXes even when it is not included in the
-	// APEXes.
-	Test_for []string
 }
 
 // Test option struct.
@@ -241,10 +236,6 @@
 	return BoolDefault(test.Properties.Gtest, true)
 }
 
-func (test *testDecorator) testFor() []string {
-	return test.Properties.Test_for
-}
-
 func (test *testDecorator) linkerFlags(ctx ModuleContext, flags Flags) Flags {
 	if !test.gtest() {
 		return flags
diff --git a/cc/testing.go b/cc/testing.go
index 95a93a0..fc5b030 100644
--- a/cc/testing.go
+++ b/cc/testing.go
@@ -29,6 +29,7 @@
 
 	ctx.RegisterModuleType("toolchain_library", ToolchainLibraryFactory)
 	ctx.RegisterModuleType("llndk_library", LlndkLibraryFactory)
+	ctx.RegisterModuleType("cc_benchmark", BenchmarkFactory)
 	ctx.RegisterModuleType("cc_object", ObjectFactory)
 	ctx.RegisterModuleType("cc_genrule", genRuleFactory)
 	ctx.RegisterModuleType("ndk_prebuilt_shared_stl", NdkPrebuiltSharedStlFactory)
@@ -334,7 +335,7 @@
 			},
 			apex_available: [
 				"//apex_available:platform",
-				"myapex"
+				"//apex_available:anyapex",
 			],
 		}
 		cc_library {
@@ -437,6 +438,13 @@
 		ndk_prebuilt_shared_stl {
 			name: "ndk_libc++_shared",
 		}
+
+		cc_library_static {
+			name: "libgoogle-benchmark",
+			sdk_version: "current",
+			stl: "none",
+			system_shared_libs: [],
+		}
 	`
 
 	supportLinuxBionic := false
diff --git a/cc/util.go b/cc/util.go
index 40374bf..1220d84 100644
--- a/cc/util.go
+++ b/cc/util.go
@@ -125,3 +125,52 @@
 	return "mkdir -p " + dir + " && " +
 		"ln -sf " + target + " " + filepath.Join(dir, linkName)
 }
+
+func copyFileRule(ctx android.SingletonContext, path android.Path, out string) android.OutputPath {
+	outPath := android.PathForOutput(ctx, out)
+	ctx.Build(pctx, android.BuildParams{
+		Rule:        android.Cp,
+		Input:       path,
+		Output:      outPath,
+		Description: "copy " + path.String() + " -> " + out,
+		Args: map[string]string{
+			"cpFlags": "-f -L",
+		},
+	})
+	return outPath
+}
+
+func combineNoticesRule(ctx android.SingletonContext, paths android.Paths, out string) android.OutputPath {
+	outPath := android.PathForOutput(ctx, out)
+	ctx.Build(pctx, android.BuildParams{
+		Rule:        android.Cat,
+		Inputs:      paths,
+		Output:      outPath,
+		Description: "combine notices for " + out,
+	})
+	return outPath
+}
+
+func writeStringToFileRule(ctx android.SingletonContext, content, out string) android.OutputPath {
+	outPath := android.PathForOutput(ctx, out)
+	android.WriteFileRule(ctx, outPath, content)
+	return outPath
+}
+
+// Dump a map to a list file as:
+//
+// {key1} {value1}
+// {key2} {value2}
+// ...
+func installMapListFileRule(ctx android.SingletonContext, m map[string]string, path string) android.OutputPath {
+	var txtBuilder strings.Builder
+	for idx, k := range android.SortedStringKeys(m) {
+		if idx > 0 {
+			txtBuilder.WriteString("\n")
+		}
+		txtBuilder.WriteString(k)
+		txtBuilder.WriteString(" ")
+		txtBuilder.WriteString(m[k])
+	}
+	return writeStringToFileRule(ctx, txtBuilder.String(), path)
+}
diff --git a/cc/vendor_snapshot.go b/cc/vendor_snapshot.go
index 7f7a1fd..da37d0f 100644
--- a/cc/vendor_snapshot.go
+++ b/cc/vendor_snapshot.go
@@ -13,625 +13,27 @@
 // limitations under the License.
 package cc
 
+// This file contains singletons to capture vendor and recovery snapshot. They consist of prebuilt
+// modules under AOSP so older vendor and recovery can be built with a newer system in a single
+// source tree.
+
 import (
 	"encoding/json"
 	"path/filepath"
 	"sort"
 	"strings"
-	"sync"
 
 	"github.com/google/blueprint/proptools"
 
 	"android/soong/android"
 )
 
-// Defines the specifics of different images to which the snapshot process is
-// applicable, e.g., vendor, recovery, ramdisk.
-type image interface {
-	// Used to register callbacks with the build system.
-	init()
-
-	// Function that returns true if the module is included in this image.
-	// Using a function return instead of a value to prevent early
-	// evalution of a function that may be not be defined.
-	inImage(m *Module) func() bool
-
-	// Returns the value of the "available" property for a given module for
-	// and snapshot, e.g., "vendor_available", "recovery_available", etc.
-	// or nil if the property is not defined.
-	available(m *Module) *bool
-
-	// Returns true if a dir under source tree is an SoC-owned proprietary
-	// directory, such as device/, vendor/, etc.
-	//
-	// For a given snapshot (e.g., vendor, recovery, etc.) if
-	// isProprietaryPath(dir) returns true, then the module in dir will be
-	// built from sources.
-	isProprietaryPath(dir string) bool
-
-	// Whether to include VNDK in the snapshot for this image.
-	includeVndk() bool
-
-	// Whether a given module has been explicitly excluded from the
-	// snapshot, e.g., using the exclude_from_vendor_snapshot or
-	// exclude_from_recovery_snapshot properties.
-	excludeFromSnapshot(m *Module) bool
-}
-
-type vendorImage struct{}
-type recoveryImage struct{}
-
-func (vendorImage) init() {
-	android.RegisterSingletonType(
-		"vendor-snapshot", VendorSnapshotSingleton)
-	android.RegisterModuleType(
-		"vendor_snapshot_shared", VendorSnapshotSharedFactory)
-	android.RegisterModuleType(
-		"vendor_snapshot_static", VendorSnapshotStaticFactory)
-	android.RegisterModuleType(
-		"vendor_snapshot_header", VendorSnapshotHeaderFactory)
-	android.RegisterModuleType(
-		"vendor_snapshot_binary", VendorSnapshotBinaryFactory)
-	android.RegisterModuleType(
-		"vendor_snapshot_object", VendorSnapshotObjectFactory)
-}
-
-func (vendorImage) inImage(m *Module) func() bool {
-	return m.inVendor
-}
-
-func (vendorImage) available(m *Module) *bool {
-	return m.VendorProperties.Vendor_available
-}
-
-func (vendorImage) isProprietaryPath(dir string) bool {
-	return isVendorProprietaryPath(dir)
-}
-
-func (vendorImage) includeVndk() bool {
-	return true
-}
-
-func (vendorImage) excludeFromSnapshot(m *Module) bool {
-	return m.ExcludeFromVendorSnapshot()
-}
-
-func (recoveryImage) init() {
-	android.RegisterSingletonType(
-		"recovery-snapshot", RecoverySnapshotSingleton)
-	android.RegisterModuleType(
-		"recovery_snapshot_shared", RecoverySnapshotSharedFactory)
-	android.RegisterModuleType(
-		"recovery_snapshot_static", RecoverySnapshotStaticFactory)
-	android.RegisterModuleType(
-		"recovery_snapshot_header", RecoverySnapshotHeaderFactory)
-	android.RegisterModuleType(
-		"recovery_snapshot_binary", RecoverySnapshotBinaryFactory)
-	android.RegisterModuleType(
-		"recovery_snapshot_object", RecoverySnapshotObjectFactory)
-}
-
-func (recoveryImage) inImage(m *Module) func() bool {
-	return m.InRecovery
-}
-
-func (recoveryImage) available(m *Module) *bool {
-	return m.Properties.Recovery_available
-}
-
-func (recoveryImage) isProprietaryPath(dir string) bool {
-	return isRecoveryProprietaryPath(dir)
-}
-
-func (recoveryImage) includeVndk() bool {
-	return false
-}
-
-func (recoveryImage) excludeFromSnapshot(m *Module) bool {
-	return m.ExcludeFromRecoverySnapshot()
-}
-
-var vendorImageSingleton vendorImage
-var recoveryImageSingleton recoveryImage
-
-const (
-	vendorSnapshotHeaderSuffix = ".vendor_header."
-	vendorSnapshotSharedSuffix = ".vendor_shared."
-	vendorSnapshotStaticSuffix = ".vendor_static."
-	vendorSnapshotBinarySuffix = ".vendor_binary."
-	vendorSnapshotObjectSuffix = ".vendor_object."
-)
-
-const (
-	recoverySnapshotHeaderSuffix = ".recovery_header."
-	recoverySnapshotSharedSuffix = ".recovery_shared."
-	recoverySnapshotStaticSuffix = ".recovery_static."
-	recoverySnapshotBinarySuffix = ".recovery_binary."
-	recoverySnapshotObjectSuffix = ".recovery_object."
-)
-
-var (
-	vendorSnapshotsLock         sync.Mutex
-	vendorSuffixModulesKey      = android.NewOnceKey("vendorSuffixModules")
-	vendorSnapshotHeaderLibsKey = android.NewOnceKey("vendorSnapshotHeaderLibs")
-	vendorSnapshotStaticLibsKey = android.NewOnceKey("vendorSnapshotStaticLibs")
-	vendorSnapshotSharedLibsKey = android.NewOnceKey("vendorSnapshotSharedLibs")
-	vendorSnapshotBinariesKey   = android.NewOnceKey("vendorSnapshotBinaries")
-	vendorSnapshotObjectsKey    = android.NewOnceKey("vendorSnapshotObjects")
-)
-
-// vendor snapshot maps hold names of vendor snapshot modules per arch
-func vendorSuffixModules(config android.Config) map[string]bool {
-	return config.Once(vendorSuffixModulesKey, func() interface{} {
-		return make(map[string]bool)
-	}).(map[string]bool)
-}
-
-func vendorSnapshotHeaderLibs(config android.Config) *snapshotMap {
-	return config.Once(vendorSnapshotHeaderLibsKey, func() interface{} {
-		return newSnapshotMap()
-	}).(*snapshotMap)
-}
-
-func vendorSnapshotSharedLibs(config android.Config) *snapshotMap {
-	return config.Once(vendorSnapshotSharedLibsKey, func() interface{} {
-		return newSnapshotMap()
-	}).(*snapshotMap)
-}
-
-func vendorSnapshotStaticLibs(config android.Config) *snapshotMap {
-	return config.Once(vendorSnapshotStaticLibsKey, func() interface{} {
-		return newSnapshotMap()
-	}).(*snapshotMap)
-}
-
-func vendorSnapshotBinaries(config android.Config) *snapshotMap {
-	return config.Once(vendorSnapshotBinariesKey, func() interface{} {
-		return newSnapshotMap()
-	}).(*snapshotMap)
-}
-
-func vendorSnapshotObjects(config android.Config) *snapshotMap {
-	return config.Once(vendorSnapshotObjectsKey, func() interface{} {
-		return newSnapshotMap()
-	}).(*snapshotMap)
-}
-
-type vendorSnapshotBaseProperties struct {
-	// snapshot version.
-	Version string
-
-	// Target arch name of the snapshot (e.g. 'arm64' for variant 'aosp_arm64')
-	Target_arch string
-}
-
-// vendorSnapshotModuleBase provides common basic functions for all snapshot modules.
-type vendorSnapshotModuleBase struct {
-	baseProperties vendorSnapshotBaseProperties
-	moduleSuffix   string
-}
-
-func (p *vendorSnapshotModuleBase) Name(name string) string {
-	return name + p.NameSuffix()
-}
-
-func (p *vendorSnapshotModuleBase) NameSuffix() string {
-	versionSuffix := p.version()
-	if p.arch() != "" {
-		versionSuffix += "." + p.arch()
-	}
-
-	return p.moduleSuffix + versionSuffix
-}
-
-func (p *vendorSnapshotModuleBase) version() string {
-	return p.baseProperties.Version
-}
-
-func (p *vendorSnapshotModuleBase) arch() string {
-	return p.baseProperties.Target_arch
-}
-
-func (p *vendorSnapshotModuleBase) isSnapshotPrebuilt() bool {
-	return true
-}
-
-// Call this after creating a snapshot module with module suffix
-// such as vendorSnapshotSharedSuffix
-func (p *vendorSnapshotModuleBase) init(m *Module, suffix string) {
-	p.moduleSuffix = suffix
-	m.AddProperties(&p.baseProperties)
-	android.AddLoadHook(m, func(ctx android.LoadHookContext) {
-		vendorSnapshotLoadHook(ctx, p)
-	})
-}
-
-func vendorSnapshotLoadHook(ctx android.LoadHookContext, p *vendorSnapshotModuleBase) {
-	if p.version() != ctx.DeviceConfig().VndkVersion() {
-		ctx.Module().Disable()
-		return
-	}
-}
-
-type snapshotLibraryProperties struct {
-	// Prebuilt file for each arch.
-	Src *string `android:"arch_variant"`
-
-	// list of directories that will be added to the include path (using -I).
-	Export_include_dirs []string `android:"arch_variant"`
-
-	// list of directories that will be added to the system path (using -isystem).
-	Export_system_include_dirs []string `android:"arch_variant"`
-
-	// list of flags that will be used for any module that links against this module.
-	Export_flags []string `android:"arch_variant"`
-
-	// Whether this prebuilt needs to depend on sanitize ubsan runtime or not.
-	Sanitize_ubsan_dep *bool `android:"arch_variant"`
-
-	// Whether this prebuilt needs to depend on sanitize minimal runtime or not.
-	Sanitize_minimal_dep *bool `android:"arch_variant"`
-}
-
-type snapshotSanitizer interface {
-	isSanitizerEnabled(t sanitizerType) bool
-	setSanitizerVariation(t sanitizerType, enabled bool)
-}
-
-type snapshotLibraryDecorator struct {
-	vendorSnapshotModuleBase
-	*libraryDecorator
-	properties          snapshotLibraryProperties
-	sanitizerProperties struct {
-		CfiEnabled bool `blueprint:"mutated"`
-
-		// Library flags for cfi variant.
-		Cfi snapshotLibraryProperties `android:"arch_variant"`
-	}
-	androidMkVendorSuffix bool
-}
-
-func (p *snapshotLibraryDecorator) linkerFlags(ctx ModuleContext, flags Flags) Flags {
-	p.libraryDecorator.libName = strings.TrimSuffix(ctx.ModuleName(), p.NameSuffix())
-	return p.libraryDecorator.linkerFlags(ctx, flags)
-}
-
-func (p *snapshotLibraryDecorator) matchesWithDevice(config android.DeviceConfig) bool {
-	arches := config.Arches()
-	if len(arches) == 0 || arches[0].ArchType.String() != p.arch() {
-		return false
-	}
-	if !p.header() && p.properties.Src == nil {
-		return false
-	}
-	return true
-}
-
-func (p *snapshotLibraryDecorator) link(ctx ModuleContext,
-	flags Flags, deps PathDeps, objs Objects) android.Path {
-	m := ctx.Module().(*Module)
-	p.androidMkVendorSuffix = vendorSuffixModules(ctx.Config())[m.BaseModuleName()]
-
-	if p.header() {
-		return p.libraryDecorator.link(ctx, flags, deps, objs)
-	}
-
-	if p.sanitizerProperties.CfiEnabled {
-		p.properties = p.sanitizerProperties.Cfi
-	}
-
-	if !p.matchesWithDevice(ctx.DeviceConfig()) {
-		return nil
-	}
-
-	p.libraryDecorator.reexportDirs(android.PathsForModuleSrc(ctx, p.properties.Export_include_dirs)...)
-	p.libraryDecorator.reexportSystemDirs(android.PathsForModuleSrc(ctx, p.properties.Export_system_include_dirs)...)
-	p.libraryDecorator.reexportFlags(p.properties.Export_flags...)
-
-	in := android.PathForModuleSrc(ctx, *p.properties.Src)
-	p.unstrippedOutputFile = in
-
-	if p.shared() {
-		libName := in.Base()
-		builderFlags := flagsToBuilderFlags(flags)
-
-		// Optimize out relinking against shared libraries whose interface hasn't changed by
-		// depending on a table of contents file instead of the library itself.
-		tocFile := android.PathForModuleOut(ctx, libName+".toc")
-		p.tocFile = android.OptionalPathForPath(tocFile)
-		transformSharedObjectToToc(ctx, in, tocFile, builderFlags)
-
-		ctx.SetProvider(SharedLibraryInfoProvider, SharedLibraryInfo{
-			SharedLibrary:           in,
-			UnstrippedSharedLibrary: p.unstrippedOutputFile,
-
-			TableOfContents: p.tocFile,
-		})
-	}
-
-	if p.static() {
-		depSet := android.NewDepSetBuilder(android.TOPOLOGICAL).Direct(in).Build()
-		ctx.SetProvider(StaticLibraryInfoProvider, StaticLibraryInfo{
-			StaticLibrary: in,
-
-			TransitiveStaticLibrariesForOrdering: depSet,
-		})
-	}
-
-	p.libraryDecorator.flagExporter.setProvider(ctx)
-
-	return in
-}
-
-func (p *snapshotLibraryDecorator) install(ctx ModuleContext, file android.Path) {
-	if p.matchesWithDevice(ctx.DeviceConfig()) && (p.shared() || p.static()) {
-		p.baseInstaller.install(ctx, file)
-	}
-}
-
-func (p *snapshotLibraryDecorator) nativeCoverage() bool {
-	return false
-}
-
-func (p *snapshotLibraryDecorator) isSanitizerEnabled(t sanitizerType) bool {
-	switch t {
-	case cfi:
-		return p.sanitizerProperties.Cfi.Src != nil
-	default:
-		return false
-	}
-}
-
-func (p *snapshotLibraryDecorator) setSanitizerVariation(t sanitizerType, enabled bool) {
-	if !enabled {
-		return
-	}
-	switch t {
-	case cfi:
-		p.sanitizerProperties.CfiEnabled = true
-	default:
-		return
-	}
-}
-
-func snapshotLibrary(suffix string) (*Module, *snapshotLibraryDecorator) {
-	module, library := NewLibrary(android.DeviceSupported)
-
-	module.stl = nil
-	module.sanitize = nil
-	library.disableStripping()
-
-	prebuilt := &snapshotLibraryDecorator{
-		libraryDecorator: library,
-	}
-
-	prebuilt.baseLinker.Properties.No_libcrt = BoolPtr(true)
-	prebuilt.baseLinker.Properties.Nocrt = BoolPtr(true)
-
-	// Prevent default system libs (libc, libm, and libdl) from being linked
-	if prebuilt.baseLinker.Properties.System_shared_libs == nil {
-		prebuilt.baseLinker.Properties.System_shared_libs = []string{}
-	}
-
-	module.compiler = nil
-	module.linker = prebuilt
-	module.installer = prebuilt
-
-	prebuilt.init(module, suffix)
-	module.AddProperties(
-		&prebuilt.properties,
-		&prebuilt.sanitizerProperties,
-	)
-
-	return module, prebuilt
-}
-
-func VendorSnapshotSharedFactory() android.Module {
-	module, prebuilt := snapshotLibrary(vendorSnapshotSharedSuffix)
-	prebuilt.libraryDecorator.BuildOnlyShared()
-	return module.Init()
-}
-
-func RecoverySnapshotSharedFactory() android.Module {
-	module, prebuilt := snapshotLibrary(recoverySnapshotSharedSuffix)
-	prebuilt.libraryDecorator.BuildOnlyShared()
-	return module.Init()
-}
-
-func VendorSnapshotStaticFactory() android.Module {
-	module, prebuilt := snapshotLibrary(vendorSnapshotStaticSuffix)
-	prebuilt.libraryDecorator.BuildOnlyStatic()
-	return module.Init()
-}
-
-func RecoverySnapshotStaticFactory() android.Module {
-	module, prebuilt := snapshotLibrary(recoverySnapshotStaticSuffix)
-	prebuilt.libraryDecorator.BuildOnlyStatic()
-	return module.Init()
-}
-
-func VendorSnapshotHeaderFactory() android.Module {
-	module, prebuilt := snapshotLibrary(vendorSnapshotHeaderSuffix)
-	prebuilt.libraryDecorator.HeaderOnly()
-	return module.Init()
-}
-
-func RecoverySnapshotHeaderFactory() android.Module {
-	module, prebuilt := snapshotLibrary(recoverySnapshotHeaderSuffix)
-	prebuilt.libraryDecorator.HeaderOnly()
-	return module.Init()
-}
-
-var _ snapshotSanitizer = (*snapshotLibraryDecorator)(nil)
-
-type snapshotBinaryProperties struct {
-	// Prebuilt file for each arch.
-	Src *string `android:"arch_variant"`
-}
-
-type snapshotBinaryDecorator struct {
-	vendorSnapshotModuleBase
-	*binaryDecorator
-	properties            snapshotBinaryProperties
-	androidMkVendorSuffix bool
-}
-
-func (p *snapshotBinaryDecorator) matchesWithDevice(config android.DeviceConfig) bool {
-	if config.DeviceArch() != p.arch() {
-		return false
-	}
-	if p.properties.Src == nil {
-		return false
-	}
-	return true
-}
-
-func (p *snapshotBinaryDecorator) link(ctx ModuleContext,
-	flags Flags, deps PathDeps, objs Objects) android.Path {
-	if !p.matchesWithDevice(ctx.DeviceConfig()) {
-		return nil
-	}
-
-	in := android.PathForModuleSrc(ctx, *p.properties.Src)
-	stripFlags := flagsToStripFlags(flags)
-	p.unstrippedOutputFile = in
-	binName := in.Base()
-	if p.stripper.NeedsStrip(ctx) {
-		stripped := android.PathForModuleOut(ctx, "stripped", binName)
-		p.stripper.StripExecutableOrSharedLib(ctx, in, stripped, stripFlags)
-		in = stripped
-	}
-
-	m := ctx.Module().(*Module)
-	p.androidMkVendorSuffix = vendorSuffixModules(ctx.Config())[m.BaseModuleName()]
-
-	// use cpExecutable to make it executable
-	outputFile := android.PathForModuleOut(ctx, binName)
-	ctx.Build(pctx, android.BuildParams{
-		Rule:        android.CpExecutable,
-		Description: "prebuilt",
-		Output:      outputFile,
-		Input:       in,
-	})
-
-	return outputFile
-}
-
-func (p *snapshotBinaryDecorator) nativeCoverage() bool {
-	return false
-}
-
-func VendorSnapshotBinaryFactory() android.Module {
-	return snapshotBinaryFactory(vendorSnapshotBinarySuffix)
-}
-
-func RecoverySnapshotBinaryFactory() android.Module {
-	return snapshotBinaryFactory(recoverySnapshotBinarySuffix)
-}
-
-func snapshotBinaryFactory(suffix string) android.Module {
-	module, binary := NewBinary(android.DeviceSupported)
-	binary.baseLinker.Properties.No_libcrt = BoolPtr(true)
-	binary.baseLinker.Properties.Nocrt = BoolPtr(true)
-
-	// Prevent default system libs (libc, libm, and libdl) from being linked
-	if binary.baseLinker.Properties.System_shared_libs == nil {
-		binary.baseLinker.Properties.System_shared_libs = []string{}
-	}
-
-	prebuilt := &snapshotBinaryDecorator{
-		binaryDecorator: binary,
-	}
-
-	module.compiler = nil
-	module.sanitize = nil
-	module.stl = nil
-	module.linker = prebuilt
-
-	prebuilt.init(module, suffix)
-	module.AddProperties(&prebuilt.properties)
-	return module.Init()
-}
-
-type vendorSnapshotObjectProperties struct {
-	// Prebuilt file for each arch.
-	Src *string `android:"arch_variant"`
-}
-
-type snapshotObjectLinker struct {
-	vendorSnapshotModuleBase
-	objectLinker
-	properties            vendorSnapshotObjectProperties
-	androidMkVendorSuffix bool
-}
-
-func (p *snapshotObjectLinker) matchesWithDevice(config android.DeviceConfig) bool {
-	if config.DeviceArch() != p.arch() {
-		return false
-	}
-	if p.properties.Src == nil {
-		return false
-	}
-	return true
-}
-
-func (p *snapshotObjectLinker) link(ctx ModuleContext,
-	flags Flags, deps PathDeps, objs Objects) android.Path {
-	if !p.matchesWithDevice(ctx.DeviceConfig()) {
-		return nil
-	}
-
-	m := ctx.Module().(*Module)
-	p.androidMkVendorSuffix = vendorSuffixModules(ctx.Config())[m.BaseModuleName()]
-
-	return android.PathForModuleSrc(ctx, *p.properties.Src)
-}
-
-func (p *snapshotObjectLinker) nativeCoverage() bool {
-	return false
-}
-
-func VendorSnapshotObjectFactory() android.Module {
-	module := newObject()
-
-	prebuilt := &snapshotObjectLinker{
-		objectLinker: objectLinker{
-			baseLinker: NewBaseLinker(nil),
-		},
-	}
-	module.linker = prebuilt
-
-	prebuilt.init(module, vendorSnapshotObjectSuffix)
-	module.AddProperties(&prebuilt.properties)
-	return module.Init()
-}
-
-func RecoverySnapshotObjectFactory() android.Module {
-	module := newObject()
-
-	prebuilt := &snapshotObjectLinker{
-		objectLinker: objectLinker{
-			baseLinker: NewBaseLinker(nil),
-		},
-	}
-	module.linker = prebuilt
-
-	prebuilt.init(module, recoverySnapshotObjectSuffix)
-	module.AddProperties(&prebuilt.properties)
-	return module.Init()
-}
-
-func init() {
-	vendorImageSingleton.init()
-	recoveryImageSingleton.init()
-}
-
 var vendorSnapshotSingleton = snapshotSingleton{
 	"vendor",
 	"SOONG_VENDOR_SNAPSHOT_ZIP",
 	android.OptionalPath{},
 	true,
-	vendorImageSingleton,
+	vendorSnapshotImageSingleton,
 }
 
 var recoverySnapshotSingleton = snapshotSingleton{
@@ -639,7 +41,7 @@
 	"SOONG_RECOVERY_SNAPSHOT_ZIP",
 	android.OptionalPath{},
 	false,
-	recoveryImageSingleton,
+	recoverySnapshotImageSingleton,
 }
 
 func VendorSnapshotSingleton() android.Singleton {
@@ -667,13 +69,12 @@
 	// Implementation of the image interface specific to the image
 	// associated with this snapshot (e.g., specific to the vendor image,
 	// recovery image, etc.).
-	image image
+	image snapshotImage
 }
 
 var (
 	// Modules under following directories are ignored. They are OEM's and vendor's
 	// proprietary modules(device/, kernel/, vendor/, and hardware/).
-	// TODO(b/65377115): Clean up these with more maintainable way
 	vendorProprietaryDirs = []string{
 		"device",
 		"kernel",
@@ -683,7 +84,6 @@
 
 	// Modules under following directories are ignored. They are OEM's and vendor's
 	// proprietary modules(device/, kernel/, vendor/, and hardware/).
-	// TODO(b/65377115): Clean up these with more maintainable way
 	recoveryProprietaryDirs = []string{
 		"bootable/recovery",
 		"device",
@@ -694,7 +94,6 @@
 
 	// Modules under following directories are included as they are in AOSP,
 	// although hardware/ and kernel/ are normally for vendor's own.
-	// TODO(b/65377115): Clean up these with more maintainable way
 	aospDirsUnderProprietary = []string{
 		"kernel/configs",
 		"kernel/prebuilts",
@@ -738,10 +137,8 @@
 }
 
 func isVendorProprietaryModule(ctx android.BaseModuleContext) bool {
-
 	// Any module in a vendor proprietary path is a vendor proprietary
 	// module.
-
 	if isVendorProprietaryPath(ctx.ModuleDir()) {
 		return true
 	}
@@ -750,7 +147,6 @@
 	// still be a vendor proprietary module. This happens for cc modules
 	// that are excluded from the vendor snapshot, and it means that the
 	// vendor has assumed control of the framework-provided module.
-
 	if c, ok := ctx.Module().(*Module); ok {
 		if c.ExcludeFromVendorSnapshot() {
 			return true
@@ -766,15 +162,21 @@
 // AOSP. They are not guaranteed to be compatible with older vendor images. (e.g. might
 // depend on newer VNDK) So they are captured as vendor snapshot To build older vendor
 // image and newer system image altogether.
-func isVendorSnapshotModule(m *Module, inVendorProprietaryPath bool, apexInfo android.ApexInfo) bool {
-	return isSnapshotModule(m, inVendorProprietaryPath, apexInfo, vendorImageSingleton)
+func isVendorSnapshotAware(m *Module, inVendorProprietaryPath bool, apexInfo android.ApexInfo) bool {
+	return isSnapshotAware(m, inVendorProprietaryPath, apexInfo, vendorSnapshotImageSingleton)
 }
 
-func isRecoverySnapshotModule(m *Module, inRecoveryProprietaryPath bool, apexInfo android.ApexInfo) bool {
-	return isSnapshotModule(m, inRecoveryProprietaryPath, apexInfo, recoveryImageSingleton)
+// Determine if a module is going to be included in recovery snapshot or not.
+//
+// Targets of recovery snapshot are "recovery: true" or "recovery_available: true"
+// modules in AOSP. They are not guaranteed to be compatible with older recovery images.
+// So they are captured as recovery snapshot To build older recovery image.
+func isRecoverySnapshotAware(m *Module, inRecoveryProprietaryPath bool, apexInfo android.ApexInfo) bool {
+	return isSnapshotAware(m, inRecoveryProprietaryPath, apexInfo, recoverySnapshotImageSingleton)
 }
 
-func isSnapshotModule(m *Module, inProprietaryPath bool, apexInfo android.ApexInfo, image image) bool {
+// Determines if the module is a candidate for snapshot.
+func isSnapshotAware(m *Module, inProprietaryPath bool, apexInfo android.ApexInfo, image snapshotImage) bool {
 	if !m.Enabled() || m.Properties.HideFromMake {
 		return false
 	}
@@ -799,7 +201,7 @@
 	if m.Target().NativeBridge == android.NativeBridgeEnabled {
 		return false
 	}
-	// the module must be installed in /vendor
+	// the module must be installed in target image
 	if !apexInfo.IsForPlatform() || m.isSnapshotPrebuilt() || !image.inImage(m)() {
 		return false
 	}
@@ -817,7 +219,6 @@
 
 	// Libraries
 	if l, ok := m.linker.(snapshotLibraryInterface); ok {
-		// TODO(b/65377115): add full support for sanitizer
 		if m.sanitize != nil {
 			// scs and hwasan export both sanitized and unsanitized variants for static and header
 			// Always use unsanitized variants of them.
@@ -827,6 +228,8 @@
 				}
 			}
 			// cfi also exports both variants. But for static, we capture both.
+			// This is because cfi static libraries can't be linked from non-cfi modules,
+			// and vice versa. This isn't the case for scs and hwasan sanitizers.
 			if !l.static() && !l.shared() && m.sanitize.isSanitizerEnabled(cfi) {
 				return false
 			}
@@ -856,6 +259,33 @@
 	return false
 }
 
+// This is to be saved as .json files, which is for development/vendor_snapshot/update.py.
+// These flags become Android.bp snapshot module properties.
+type snapshotJsonFlags struct {
+	ModuleName          string `json:",omitempty"`
+	RelativeInstallPath string `json:",omitempty"`
+
+	// library flags
+	ExportedDirs       []string `json:",omitempty"`
+	ExportedSystemDirs []string `json:",omitempty"`
+	ExportedFlags      []string `json:",omitempty"`
+	Sanitize           string   `json:",omitempty"`
+	SanitizeMinimalDep bool     `json:",omitempty"`
+	SanitizeUbsanDep   bool     `json:",omitempty"`
+
+	// binary flags
+	Symlinks []string `json:",omitempty"`
+
+	// dependencies
+	SharedLibs  []string `json:",omitempty"`
+	RuntimeLibs []string `json:",omitempty"`
+	Required    []string `json:",omitempty"`
+
+	// extra config files
+	InitRc         []string `json:",omitempty"`
+	VintfFragments []string `json:",omitempty"`
+}
+
 func (c *snapshotSingleton) GenerateBuildActions(ctx android.SingletonContext) {
 	// BOARD_VNDK_VERSION must be set to 'current' in order to generate a vendor snapshot.
 	if ctx.DeviceConfig().VndkVersion() != "current" {
@@ -909,6 +339,8 @@
 
 	var headers android.Paths
 
+	// installSnapshot function copies prebuilt file (.so, .a, or executable) and json flag file.
+	// For executables, init_rc and vintf_fragments files are also copied.
 	installSnapshot := func(m *Module) android.Paths {
 		targetArch := "arch-" + m.Target().Arch.ArchType.String()
 		if m.Target().Arch.ArchVariant != "" {
@@ -917,30 +349,7 @@
 
 		var ret android.Paths
 
-		prop := struct {
-			ModuleName          string `json:",omitempty"`
-			RelativeInstallPath string `json:",omitempty"`
-
-			// library flags
-			ExportedDirs       []string `json:",omitempty"`
-			ExportedSystemDirs []string `json:",omitempty"`
-			ExportedFlags      []string `json:",omitempty"`
-			Sanitize           string   `json:",omitempty"`
-			SanitizeMinimalDep bool     `json:",omitempty"`
-			SanitizeUbsanDep   bool     `json:",omitempty"`
-
-			// binary flags
-			Symlinks []string `json:",omitempty"`
-
-			// dependencies
-			SharedLibs  []string `json:",omitempty"`
-			RuntimeLibs []string `json:",omitempty"`
-			Required    []string `json:",omitempty"`
-
-			// extra config files
-			InitRc         []string `json:",omitempty"`
-			VintfFragments []string `json:",omitempty"`
-		}{}
+		prop := snapshotJsonFlags{}
 
 		// Common properties among snapshots.
 		prop.ModuleName = ctx.ModuleName(m)
@@ -968,7 +377,7 @@
 			out := filepath.Join(configsDir, path.Base())
 			if !installedConfigs[out] {
 				installedConfigs[out] = true
-				ret = append(ret, copyFile(ctx, path, out))
+				ret = append(ret, copyFileRule(ctx, path, out))
 			}
 		}
 
@@ -1019,7 +428,7 @@
 					prop.ModuleName += ".cfi"
 				}
 				snapshotLibOut := filepath.Join(snapshotArchDir, targetArch, libType, stem)
-				ret = append(ret, copyFile(ctx, libPath, snapshotLibOut))
+				ret = append(ret, copyFileRule(ctx, libPath, snapshotLibOut))
 			} else {
 				stem = ctx.ModuleName(m)
 			}
@@ -1033,7 +442,7 @@
 			// install bin
 			binPath := m.outputFile.Path()
 			snapshotBinOut := filepath.Join(snapshotArchDir, targetArch, "binary", binPath.Base())
-			ret = append(ret, copyFile(ctx, binPath, snapshotBinOut))
+			ret = append(ret, copyFileRule(ctx, binPath, snapshotBinOut))
 			propOut = snapshotBinOut + ".json"
 		} else if m.object() {
 			// object files aren't installed to the device, so their names can conflict.
@@ -1041,7 +450,7 @@
 			objPath := m.outputFile.Path()
 			snapshotObjOut := filepath.Join(snapshotArchDir, targetArch, "object",
 				ctx.ModuleName(m)+filepath.Ext(objPath.Base()))
-			ret = append(ret, copyFile(ctx, objPath, snapshotObjOut))
+			ret = append(ret, copyFileRule(ctx, objPath, snapshotObjOut))
 			propOut = snapshotObjOut + ".json"
 		} else {
 			ctx.Errorf("unknown module %q in vendor snapshot", m.String())
@@ -1053,7 +462,7 @@
 			ctx.Errorf("json marshal to %q failed: %#v", propOut, err)
 			return nil
 		}
-		ret = append(ret, writeStringToFile(ctx, string(j), propOut))
+		ret = append(ret, writeStringToFileRule(ctx, string(j), propOut))
 
 		return ret
 	}
@@ -1088,11 +497,14 @@
 			}
 		}
 
-		if !isSnapshotModule(m, inProprietaryPath, apexInfo, c.image) {
+		if !isSnapshotAware(m, inProprietaryPath, apexInfo, c.image) {
 			return
 		}
 
+		// installSnapshot installs prebuilts and json flag files
 		snapshotOutputs = append(snapshotOutputs, installSnapshot(m)...)
+
+		// just gather headers and notice files here, because they are to be deduplicated
 		if l, ok := m.linker.(snapshotLibraryInterface); ok {
 			headers = append(headers, l.snapshotHeaders()...)
 		}
@@ -1103,7 +515,7 @@
 			// skip already copied notice file
 			if !installedNotices[noticeOut] {
 				installedNotices[noticeOut] = true
-				snapshotOutputs = append(snapshotOutputs, combineNotices(
+				snapshotOutputs = append(snapshotOutputs, combineNoticesRule(
 					ctx, m.NoticeFiles(), noticeOut))
 			}
 		}
@@ -1111,7 +523,7 @@
 
 	// install all headers after removing duplicates
 	for _, header := range android.FirstUniquePaths(headers) {
-		snapshotOutputs = append(snapshotOutputs, copyFile(
+		snapshotOutputs = append(snapshotOutputs, copyFileRule(
 			ctx, header, filepath.Join(includeDir, header.String())))
 	}
 
@@ -1155,141 +567,3 @@
 		c.makeVar,
 		c.snapshotZipFile.String())
 }
-
-type snapshotInterface interface {
-	matchesWithDevice(config android.DeviceConfig) bool
-}
-
-var _ snapshotInterface = (*vndkPrebuiltLibraryDecorator)(nil)
-var _ snapshotInterface = (*snapshotLibraryDecorator)(nil)
-var _ snapshotInterface = (*snapshotBinaryDecorator)(nil)
-var _ snapshotInterface = (*snapshotObjectLinker)(nil)
-
-// gathers all snapshot modules for vendor, and disable unnecessary snapshots
-// TODO(b/145966707): remove mutator and utilize android.Prebuilt to override source modules
-func VendorSnapshotMutator(ctx android.BottomUpMutatorContext) {
-	vndkVersion := ctx.DeviceConfig().VndkVersion()
-	// don't need snapshot if current
-	if vndkVersion == "current" || vndkVersion == "" {
-		return
-	}
-
-	module, ok := ctx.Module().(*Module)
-	if !ok || !module.Enabled() || module.VndkVersion() != vndkVersion {
-		return
-	}
-
-	if !module.isSnapshotPrebuilt() {
-		return
-	}
-
-	// isSnapshotPrebuilt ensures snapshotInterface
-	if !module.linker.(snapshotInterface).matchesWithDevice(ctx.DeviceConfig()) {
-		// Disable unnecessary snapshot module, but do not disable
-		// vndk_prebuilt_shared because they might be packed into vndk APEX
-		if !module.IsVndk() {
-			module.Disable()
-		}
-		return
-	}
-
-	var snapshotMap *snapshotMap
-
-	if lib, ok := module.linker.(libraryInterface); ok {
-		if lib.static() {
-			snapshotMap = vendorSnapshotStaticLibs(ctx.Config())
-		} else if lib.shared() {
-			snapshotMap = vendorSnapshotSharedLibs(ctx.Config())
-		} else {
-			// header
-			snapshotMap = vendorSnapshotHeaderLibs(ctx.Config())
-		}
-	} else if _, ok := module.linker.(*snapshotBinaryDecorator); ok {
-		snapshotMap = vendorSnapshotBinaries(ctx.Config())
-	} else if _, ok := module.linker.(*snapshotObjectLinker); ok {
-		snapshotMap = vendorSnapshotObjects(ctx.Config())
-	} else {
-		return
-	}
-
-	vendorSnapshotsLock.Lock()
-	defer vendorSnapshotsLock.Unlock()
-	snapshotMap.add(module.BaseModuleName(), ctx.Arch().ArchType, ctx.ModuleName())
-}
-
-// Disables source modules which have snapshots
-func VendorSnapshotSourceMutator(ctx android.BottomUpMutatorContext) {
-	if !ctx.Device() {
-		return
-	}
-
-	vndkVersion := ctx.DeviceConfig().VndkVersion()
-	// don't need snapshot if current
-	if vndkVersion == "current" || vndkVersion == "" {
-		return
-	}
-
-	module, ok := ctx.Module().(*Module)
-	if !ok {
-		return
-	}
-
-	// vendor suffix should be added to snapshots if the source module isn't vendor: true.
-	if !module.SocSpecific() {
-		// But we can't just check SocSpecific() since we already passed the image mutator.
-		// Check ramdisk and recovery to see if we are real "vendor: true" module.
-		ramdisk_available := module.InRamdisk() && !module.OnlyInRamdisk()
-		vendor_ramdisk_available := module.InVendorRamdisk() && !module.OnlyInVendorRamdisk()
-		recovery_available := module.InRecovery() && !module.OnlyInRecovery()
-
-		if !ramdisk_available && !recovery_available && !vendor_ramdisk_available {
-			vendorSnapshotsLock.Lock()
-			defer vendorSnapshotsLock.Unlock()
-
-			vendorSuffixModules(ctx.Config())[ctx.ModuleName()] = true
-		}
-	}
-
-	if module.isSnapshotPrebuilt() || module.VndkVersion() != ctx.DeviceConfig().VndkVersion() {
-		// only non-snapshot modules with BOARD_VNDK_VERSION
-		return
-	}
-
-	// .. and also filter out llndk library
-	if module.isLlndk(ctx.Config()) {
-		return
-	}
-
-	var snapshotMap *snapshotMap
-
-	if lib, ok := module.linker.(libraryInterface); ok {
-		if lib.static() {
-			snapshotMap = vendorSnapshotStaticLibs(ctx.Config())
-		} else if lib.shared() {
-			snapshotMap = vendorSnapshotSharedLibs(ctx.Config())
-		} else {
-			// header
-			snapshotMap = vendorSnapshotHeaderLibs(ctx.Config())
-		}
-	} else if module.binary() {
-		snapshotMap = vendorSnapshotBinaries(ctx.Config())
-	} else if module.object() {
-		snapshotMap = vendorSnapshotObjects(ctx.Config())
-	} else {
-		return
-	}
-
-	if _, ok := snapshotMap.get(ctx.ModuleName(), ctx.Arch().ArchType); !ok {
-		// Corresponding snapshot doesn't exist
-		return
-	}
-
-	// Disables source modules if corresponding snapshot exists.
-	if lib, ok := module.linker.(libraryInterface); ok && lib.buildStatic() && lib.buildShared() {
-		// But do not disable because the shared variant depends on the static variant.
-		module.SkipInstall()
-		module.Properties.HideFromMake = true
-	} else {
-		module.Disable()
-	}
-}
diff --git a/cc/vndk.go b/cc/vndk.go
index cdd66a8..1529ac5 100644
--- a/cc/vndk.go
+++ b/cc/vndk.go
@@ -533,7 +533,7 @@
 	vndkSnapshotZipFile android.OptionalPath
 }
 
-func isVndkSnapshotLibrary(config android.DeviceConfig, m *Module,
+func isVndkSnapshotAware(config android.DeviceConfig, m *Module,
 	apexInfo android.ApexInfo) (i snapshotLibraryInterface, vndkType string, isVndkSnapshotLib bool) {
 
 	if m.Target().NativeBridge == android.NativeBridgeEnabled {
@@ -622,6 +622,9 @@
 
 	var headers android.Paths
 
+	// installVndkSnapshotLib copies built .so file from the module.
+	// Also, if the build artifacts is on, write a json file which contains all exported flags
+	// with FlagExporterInfo.
 	installVndkSnapshotLib := func(m *Module, vndkType string) (android.Paths, bool) {
 		var ret android.Paths
 
@@ -632,7 +635,7 @@
 
 		libPath := m.outputFile.Path()
 		snapshotLibOut := filepath.Join(snapshotArchDir, targetArch, "shared", vndkType, libPath.Base())
-		ret = append(ret, copyFile(ctx, libPath, snapshotLibOut))
+		ret = append(ret, copyFileRule(ctx, libPath, snapshotLibOut))
 
 		if ctx.Config().VndkSnapshotBuildArtifacts() {
 			prop := struct {
@@ -654,7 +657,7 @@
 				ctx.Errorf("json marshal to %q failed: %#v", propOut, err)
 				return nil, false
 			}
-			ret = append(ret, writeStringToFile(ctx, string(j), propOut))
+			ret = append(ret, writeStringToFileRule(ctx, string(j), propOut))
 		}
 		return ret, true
 	}
@@ -667,11 +670,21 @@
 
 		apexInfo := ctx.ModuleProvider(module, android.ApexInfoProvider).(android.ApexInfo)
 
-		l, vndkType, ok := isVndkSnapshotLibrary(ctx.DeviceConfig(), m, apexInfo)
+		l, vndkType, ok := isVndkSnapshotAware(ctx.DeviceConfig(), m, apexInfo)
 		if !ok {
 			return
 		}
 
+		// For all snapshot candidates, the followings are captured.
+		//   - .so files
+		//   - notice files
+		//
+		// The followings are also captured if VNDK_SNAPSHOT_BUILD_ARTIFACTS.
+		//   - .json files containing exported flags
+		//   - exported headers from collectHeadersForSnapshot()
+		//
+		// Headers are deduplicated after visiting all modules.
+
 		// install .so files for appropriate modules.
 		// Also install .json files if VNDK_SNAPSHOT_BUILD_ARTIFACTS
 		libs, ok := installVndkSnapshotLib(m, vndkType)
@@ -690,7 +703,7 @@
 			// skip already copied notice file
 			if _, ok := noticeBuilt[noticeName]; !ok {
 				noticeBuilt[noticeName] = true
-				snapshotOutputs = append(snapshotOutputs, combineNotices(
+				snapshotOutputs = append(snapshotOutputs, combineNoticesRule(
 					ctx, m.NoticeFiles(), filepath.Join(noticeDir, noticeName)))
 			}
 		}
@@ -702,7 +715,7 @@
 
 	// install all headers after removing duplicates
 	for _, header := range android.FirstUniquePaths(headers) {
-		snapshotOutputs = append(snapshotOutputs, copyFile(
+		snapshotOutputs = append(snapshotOutputs, copyFileRule(
 			ctx, header, filepath.Join(includeDir, header.String())))
 	}
 
@@ -712,38 +725,18 @@
 		if !ok || !m.Enabled() || m.Name() == vndkUsingCoreVariantLibrariesTxt {
 			return
 		}
-		snapshotOutputs = append(snapshotOutputs, copyFile(
+		snapshotOutputs = append(snapshotOutputs, copyFileRule(
 			ctx, m.OutputFile(), filepath.Join(configsDir, m.Name())))
 	})
 
 	/*
-		Dump a map to a list file as:
-
-		{key1} {value1}
-		{key2} {value2}
-		...
-	*/
-	installMapListFile := func(m map[string]string, path string) android.OutputPath {
-		var txtBuilder strings.Builder
-		for idx, k := range android.SortedStringKeys(m) {
-			if idx > 0 {
-				txtBuilder.WriteString("\n")
-			}
-			txtBuilder.WriteString(k)
-			txtBuilder.WriteString(" ")
-			txtBuilder.WriteString(m[k])
-		}
-		return writeStringToFile(ctx, txtBuilder.String(), path)
-	}
-
-	/*
 		module_paths.txt contains paths on which VNDK modules are defined.
 		e.g.,
 			libbase.so system/libbase
 			libc.so bionic/libc
 			...
 	*/
-	snapshotOutputs = append(snapshotOutputs, installMapListFile(modulePaths, filepath.Join(configsDir, "module_paths.txt")))
+	snapshotOutputs = append(snapshotOutputs, installMapListFileRule(ctx, modulePaths, filepath.Join(configsDir, "module_paths.txt")))
 
 	/*
 		module_names.txt contains names as which VNDK modules are defined,
@@ -754,7 +747,7 @@
 			libprotobuf-cpp-full-3.9.2.so libprotobuf-cpp-full
 			...
 	*/
-	snapshotOutputs = append(snapshotOutputs, installMapListFile(moduleNames, filepath.Join(configsDir, "module_names.txt")))
+	snapshotOutputs = append(snapshotOutputs, installMapListFileRule(ctx, moduleNames, filepath.Join(configsDir, "module_names.txt")))
 
 	// All artifacts are ready. Sort them to normalize ninja and then zip.
 	sort.Slice(snapshotOutputs, func(i, j int) bool {
@@ -764,7 +757,7 @@
 	zipPath := android.PathForOutput(ctx, snapshotDir, "android-vndk-"+ctx.DeviceConfig().DeviceArch()+".zip")
 	zipRule := android.NewRuleBuilder(pctx, ctx)
 
-	// filenames in rspfile from FlagWithRspFileInputList might be single-quoted. Remove it with xargs
+	// filenames in rspfile from FlagWithRspFileInputList might be single-quoted. Remove it with tr
 	snapshotOutputList := android.PathForOutput(ctx, snapshotDir, "android-vndk-"+ctx.DeviceConfig().DeviceArch()+"_list")
 	zipRule.Command().
 		Text("tr").
diff --git a/cmd/multiproduct_kati/main.go b/cmd/multiproduct_kati/main.go
index 0a9b156..c079e83 100644
--- a/cmd/multiproduct_kati/main.go
+++ b/cmd/multiproduct_kati/main.go
@@ -185,7 +185,11 @@
 		Status:  stat,
 	}}
 
-	config := build.NewConfig(buildCtx)
+	args := ""
+	if *alternateResultDir {
+		args = "dist"
+	}
+	config := build.NewConfig(buildCtx, args)
 	if *outDir == "" {
 		name := "multiproduct"
 		if !*incremental {
@@ -212,15 +216,10 @@
 	os.MkdirAll(logsDir, 0777)
 
 	build.SetupOutDir(buildCtx, config)
-	if *alternateResultDir {
-		distLogsDir := filepath.Join(config.DistDir(), "logs")
-		os.MkdirAll(distLogsDir, 0777)
-		log.SetOutput(filepath.Join(distLogsDir, "soong.log"))
-		trace.SetOutput(filepath.Join(distLogsDir, "build.trace"))
-	} else {
-		log.SetOutput(filepath.Join(config.OutDir(), "soong.log"))
-		trace.SetOutput(filepath.Join(config.OutDir(), "build.trace"))
-	}
+
+	os.MkdirAll(config.LogsDir(), 0777)
+	log.SetOutput(filepath.Join(config.LogsDir(), "soong.log"))
+	trace.SetOutput(filepath.Join(config.LogsDir(), "build.trace"))
 
 	var jobs = *numJobs
 	if jobs < 1 {
@@ -344,7 +343,7 @@
 			FileArgs: []zip.FileArg{
 				{GlobDir: logsDir, SourcePrefixToStrip: logsDir},
 			},
-			OutputFilePath:   filepath.Join(config.DistDir(), "logs.zip"),
+			OutputFilePath:   filepath.Join(config.RealDistDir(), "logs.zip"),
 			NumParallelJobs:  runtime.NumCPU(),
 			CompressionLevel: 5,
 		}
diff --git a/cmd/sbox/sbox.go b/cmd/sbox/sbox.go
index a4f57ea..f8919a4 100644
--- a/cmd/sbox/sbox.go
+++ b/cmd/sbox/sbox.go
@@ -337,7 +337,7 @@
 	for _, copyPair := range copies {
 		fromPath := joinPath(fromDir, copyPair.GetFrom())
 		toPath := joinPath(toDir, copyPair.GetTo())
-		err := copyOneFile(fromPath, toPath)
+		err := copyOneFile(fromPath, toPath, copyPair.GetExecutable())
 		if err != nil {
 			return fmt.Errorf("error copying %q to %q: %w", fromPath, toPath, err)
 		}
@@ -346,7 +346,7 @@
 }
 
 // copyOneFile copies a file.
-func copyOneFile(from string, to string) error {
+func copyOneFile(from string, to string, executable bool) error {
 	err := os.MkdirAll(filepath.Dir(to), 0777)
 	if err != nil {
 		return err
@@ -358,6 +358,9 @@
 	}
 
 	perm := stat.Mode()
+	if executable {
+		perm = perm | 0100 // u+x
+	}
 
 	in, err := os.Open(from)
 	if err != nil {
diff --git a/cmd/sbox/sbox_proto/sbox.pb.go b/cmd/sbox/sbox_proto/sbox.pb.go
index 6584bdf..79bb90c 100644
--- a/cmd/sbox/sbox_proto/sbox.pb.go
+++ b/cmd/sbox/sbox_proto/sbox.pb.go
@@ -156,8 +156,10 @@
 // are relative to is specific to the context the Copy is used in and will be different for
 // from and to.
 type Copy struct {
-	From                 *string  `protobuf:"bytes,1,req,name=from" json:"from,omitempty"`
-	To                   *string  `protobuf:"bytes,2,req,name=to" json:"to,omitempty"`
+	From *string `protobuf:"bytes,1,req,name=from" json:"from,omitempty"`
+	To   *string `protobuf:"bytes,2,req,name=to" json:"to,omitempty"`
+	// If true, make the file executable after copying it.
+	Executable           *bool    `protobuf:"varint,3,opt,name=executable" json:"executable,omitempty"`
 	XXX_NoUnkeyedLiteral struct{} `json:"-"`
 	XXX_unrecognized     []byte   `json:"-"`
 	XXX_sizecache        int32    `json:"-"`
@@ -202,6 +204,13 @@
 	return ""
 }
 
+func (m *Copy) GetExecutable() bool {
+	if m != nil && m.Executable != nil {
+		return *m.Executable
+	}
+	return false
+}
+
 func init() {
 	proto.RegisterType((*Manifest)(nil), "sbox.Manifest")
 	proto.RegisterType((*Command)(nil), "sbox.Command")
@@ -213,21 +222,22 @@
 }
 
 var fileDescriptor_9d0425bf0de86ed1 = []byte{
-	// 252 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x64, 0x90, 0x41, 0x4b, 0xc3, 0x40,
-	0x10, 0x85, 0x49, 0x9a, 0xd2, 0x66, 0x6a, 0x7b, 0x18, 0x3c, 0xec, 0x45, 0x08, 0x01, 0x21, 0x55,
-	0xe8, 0xc1, 0x7f, 0x60, 0xf5, 0xe0, 0xc5, 0xcb, 0x1e, 0x45, 0x08, 0xdb, 0x64, 0x97, 0x04, 0x4c,
-	0x66, 0xd9, 0xdd, 0x82, 0xfd, 0x57, 0xfe, 0x44, 0xd9, 0x49, 0xea, 0xc5, 0xdb, 0xcc, 0xfb, 0x78,
-	0xf3, 0x1e, 0x03, 0xe0, 0x4f, 0xf4, 0x7d, 0xb0, 0x8e, 0x02, 0x61, 0x16, 0xe7, 0xf2, 0x13, 0xd6,
-	0xef, 0x6a, 0xec, 0x8d, 0xf6, 0x01, 0xf7, 0xb0, 0x6e, 0x68, 0x18, 0xd4, 0xd8, 0x7a, 0x91, 0x14,
-	0x8b, 0x6a, 0xf3, 0xb4, 0x3d, 0xb0, 0xe1, 0x65, 0x52, 0xe5, 0x1f, 0xc6, 0x7b, 0xd8, 0xd1, 0x39,
-	0xd8, 0x73, 0xa8, 0x5b, 0x6d, 0x4d, 0xff, 0xa5, 0x45, 0x5a, 0x24, 0x55, 0x2e, 0xb7, 0x93, 0xfa,
-	0x3a, 0x89, 0xe5, 0x4f, 0x02, 0xab, 0xd9, 0x8c, 0x8f, 0xb0, 0x69, 0xc8, 0x5e, 0xea, 0x93, 0x36,
-	0xe4, 0xf4, 0x1c, 0x00, 0xd7, 0x00, 0x7b, 0x91, 0x10, 0xf1, 0x91, 0x29, 0xde, 0xc2, 0xb2, 0xe9,
-	0xda, 0xde, 0xf1, 0xd9, 0xb5, 0x9c, 0x16, 0x14, 0xb0, 0x9a, 0x1b, 0x88, 0x45, 0x91, 0x56, 0xb9,
-	0xbc, 0xae, 0xb8, 0x07, 0x76, 0xd7, 0xca, 0x04, 0xed, 0x44, 0xf6, 0xef, 0x76, 0x1e, 0xe9, 0x73,
-	0x84, 0x78, 0x07, 0xd0, 0x8f, 0xb1, 0x79, 0xa7, 0x7c, 0x27, 0x96, 0x5c, 0x3b, 0x67, 0xe5, 0x4d,
-	0xf9, 0xae, 0x7c, 0x80, 0x2c, 0x3a, 0x10, 0x21, 0x33, 0x8e, 0x06, 0x91, 0x70, 0x10, 0xcf, 0xb8,
-	0x83, 0x34, 0x90, 0x48, 0x59, 0x49, 0x03, 0x1d, 0x6f, 0x3e, 0xf8, 0xa1, 0x35, 0x3f, 0xf4, 0x37,
-	0x00, 0x00, 0xff, 0xff, 0x95, 0x4d, 0xee, 0x7d, 0x5d, 0x01, 0x00, 0x00,
+	// 268 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x64, 0x90, 0x4f, 0x4b, 0xc3, 0x40,
+	0x10, 0xc5, 0xc9, 0x9f, 0xd2, 0x64, 0x6a, 0x7b, 0x18, 0x3c, 0xec, 0x45, 0x09, 0x01, 0x21, 0x45,
+	0xe8, 0xc1, 0x6f, 0x60, 0xf5, 0x20, 0x82, 0x97, 0x1c, 0x45, 0x08, 0x9b, 0x64, 0x43, 0x02, 0x4d,
+	0x26, 0xec, 0x6e, 0xa0, 0xfd, 0x56, 0x7e, 0x44, 0xd9, 0x49, 0x2a, 0x82, 0xb7, 0x99, 0xdf, 0xe3,
+	0xcd, 0x7b, 0x0c, 0x80, 0x29, 0xe9, 0x7c, 0x18, 0x35, 0x59, 0xc2, 0xd0, 0xcd, 0xe9, 0x17, 0x44,
+	0x1f, 0x72, 0xe8, 0x1a, 0x65, 0x2c, 0xee, 0x21, 0xaa, 0xa8, 0xef, 0xe5, 0x50, 0x1b, 0xe1, 0x25,
+	0x41, 0xb6, 0x79, 0xda, 0x1e, 0xd8, 0xf0, 0x32, 0xd3, 0xfc, 0x57, 0xc6, 0x07, 0xd8, 0xd1, 0x64,
+	0xc7, 0xc9, 0x16, 0xb5, 0x1a, 0x9b, 0xee, 0xa4, 0x84, 0x9f, 0x78, 0x59, 0x9c, 0x6f, 0x67, 0xfa,
+	0x3a, 0xc3, 0xf4, 0xdb, 0x83, 0xf5, 0x62, 0xc6, 0x47, 0xd8, 0x54, 0x34, 0x5e, 0x8a, 0x52, 0x35,
+	0xa4, 0xd5, 0x12, 0x00, 0xd7, 0x80, 0xf1, 0x92, 0x83, 0x93, 0x8f, 0xac, 0xe2, 0x2d, 0xac, 0xaa,
+	0xb6, 0xee, 0x34, 0x9f, 0x8d, 0xf2, 0x79, 0x41, 0x01, 0xeb, 0xa5, 0x81, 0x08, 0x12, 0x3f, 0x8b,
+	0xf3, 0xeb, 0x8a, 0x7b, 0x60, 0x77, 0x21, 0x1b, 0xab, 0xb4, 0x08, 0xff, 0xdd, 0x8e, 0x9d, 0xfa,
+	0xec, 0x44, 0xbc, 0x03, 0xe8, 0x06, 0xd7, 0xbc, 0x95, 0xa6, 0x15, 0x2b, 0xae, 0x1d, 0x33, 0x79,
+	0x93, 0xa6, 0x4d, 0xdf, 0x21, 0x74, 0x0e, 0x44, 0x08, 0x1b, 0x4d, 0xbd, 0xf0, 0x38, 0x88, 0x67,
+	0xdc, 0x81, 0x6f, 0x49, 0xf8, 0x4c, 0x7c, 0x4b, 0x78, 0x0f, 0xa0, 0xce, 0xaa, 0x9a, 0xac, 0x2c,
+	0x4f, 0x4a, 0x04, 0x5c, 0xf5, 0x0f, 0x39, 0xde, 0x7c, 0xf2, 0xc3, 0x0b, 0x7e, 0xf8, 0x4f, 0x00,
+	0x00, 0x00, 0xff, 0xff, 0x78, 0x37, 0x3e, 0x6a, 0x7d, 0x01, 0x00, 0x00,
 }
diff --git a/cmd/sbox/sbox_proto/sbox.proto b/cmd/sbox/sbox_proto/sbox.proto
index ab95545..695b0e8 100644
--- a/cmd/sbox/sbox_proto/sbox.proto
+++ b/cmd/sbox/sbox_proto/sbox.proto
@@ -55,4 +55,7 @@
 message Copy {
   required string from = 1;
   required string to = 2;
+
+  // If true, make the file executable after copying it.
+  optional bool executable = 3;
 }
\ No newline at end of file
diff --git a/cmd/soong_build/main.go b/cmd/soong_build/main.go
index d758de2..907bed3 100644
--- a/cmd/soong_build/main.go
+++ b/cmd/soong_build/main.go
@@ -51,10 +51,22 @@
 	return android.NewNameResolver(exportFilter)
 }
 
+// bazelConversionRequested checks that the user is intending to convert
+// Blueprint to Bazel BUILD files.
+func bazelConversionRequested(configuration android.Config) bool {
+	return configuration.IsEnvTrue("CONVERT_TO_BAZEL")
+}
+
 func newContext(srcDir string, configuration android.Config) *android.Context {
 	ctx := android.NewContext(configuration)
-	ctx.Register()
-	if !shouldPrepareBuildActions() {
+	if bazelConversionRequested(configuration) {
+		// Register an alternate set of singletons and mutators for bazel
+		// conversion for Bazel conversion.
+		ctx.RegisterForBazelConversion()
+	} else {
+		ctx.Register()
+	}
+	if !shouldPrepareBuildActions(configuration) {
 		configuration.SetStopBefore(bootstrap.StopBeforePrepareBuildActions)
 	}
 	ctx.SetNameInterface(newNameResolver(configuration))
@@ -114,6 +126,8 @@
 		ctx = newContext(srcDir, configuration)
 		bootstrap.Main(ctx.Context, configuration, extraNinjaDeps...)
 	}
+
+	// Convert the Soong module graph into Bazel BUILD files.
 	if bazelQueryViewDir != "" {
 		if err := createBazelQueryView(ctx, bazelQueryViewDir); err != nil {
 			fmt.Fprintf(os.Stderr, "%s", err)
@@ -130,7 +144,7 @@
 
 	// TODO(ccross): make this a command line argument.  Requires plumbing through blueprint
 	//  to affect the command line of the primary builder.
-	if shouldPrepareBuildActions() {
+	if shouldPrepareBuildActions(configuration) {
 		metricsFile := filepath.Join(bootstrap.BuildDir, "soong_build_metrics.pb")
 		err := android.WriteMetrics(configuration, metricsFile)
 		if err != nil {
@@ -140,8 +154,19 @@
 	}
 }
 
-func shouldPrepareBuildActions() bool {
-	// If we're writing soong_docs or queryview, don't write build.ninja or
-	// collect metrics.
-	return docFile == "" && bazelQueryViewDir == ""
+// shouldPrepareBuildActions reads configuration and flags if build actions
+// should be generated.
+func shouldPrepareBuildActions(configuration android.Config) bool {
+	// Generating Soong docs
+	if docFile != "" {
+		return false
+	}
+
+	// Generating a directory for Soong query (queryview)
+	if bazelQueryViewDir != "" {
+		return false
+	}
+
+	// Generating a directory for converted Bazel BUILD files
+	return !bazelConversionRequested(configuration)
 }
diff --git a/cmd/soong_build/writedocs.go b/cmd/soong_build/writedocs.go
index 5fb6e6b..253979e 100644
--- a/cmd/soong_build/writedocs.go
+++ b/cmd/soong_build/writedocs.go
@@ -44,9 +44,10 @@
 	"name":             0,
 	"src":              1,
 	"srcs":             2,
-	"defaults":         3,
-	"host_supported":   4,
-	"device_supported": 5,
+	"exclude_srcs":     3,
+	"defaults":         4,
+	"host_supported":   5,
+	"device_supported": 6,
 }
 
 // For each module type, extract its documentation and convert it to the template data.
diff --git a/cmd/soong_ui/main.go b/cmd/soong_ui/main.go
index 29030d6..bd1d450 100644
--- a/cmd/soong_ui/main.go
+++ b/cmd/soong_ui/main.go
@@ -18,6 +18,7 @@
 	"context"
 	"flag"
 	"fmt"
+	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -173,16 +174,18 @@
 
 	build.SetupOutDir(buildCtx, config)
 
-	// Set up files to be outputted in the log directory.
-	logsDir := config.OutDir()
-	if config.Dist() {
-		logsDir = filepath.Join(config.DistDir(), "logs")
+	if config.UseBazel() {
+		defer populateExternalDistDir(buildCtx, config)
 	}
 
+	// Set up files to be outputted in the log directory.
+	logsDir := config.LogsDir()
+
+	// Common list of metric file definition.
 	buildErrorFile := filepath.Join(logsDir, c.logsPrefix+"build_error")
 	rbeMetricsFile := filepath.Join(logsDir, c.logsPrefix+"rbe_metrics.pb")
 	soongMetricsFile := filepath.Join(logsDir, c.logsPrefix+"soong_metrics")
-	defer build.UploadMetrics(buildCtx, config, c.simpleOutput, buildStarted, buildErrorFile, rbeMetricsFile, soongMetricsFile)
+
 	build.PrintOutDirWarning(buildCtx, config)
 
 	os.MkdirAll(logsDir, 0777)
@@ -198,8 +201,22 @@
 	buildCtx.Verbosef("Parallelism (local/remote/highmem): %v/%v/%v",
 		config.Parallel(), config.RemoteParallel(), config.HighmemParallel())
 
-	defer met.Dump(soongMetricsFile)
-	defer build.DumpRBEMetrics(buildCtx, config, rbeMetricsFile)
+	{
+		// The order of the function calls is important. The last defer function call
+		// is the first one that is executed to save the rbe metrics to a protobuf
+		// file. The soong metrics file is then next. Bazel profiles are written
+		// before the uploadMetrics is invoked. The written files are then uploaded
+		// if the uploading of the metrics is enabled.
+		files := []string{
+			buildErrorFile,           // build error strings
+			rbeMetricsFile,           // high level metrics related to remote build execution.
+			soongMetricsFile,         // high level metrics related to this build system.
+			config.BazelMetricsDir(), // directory that contains a set of bazel metrics.
+		}
+		defer build.UploadMetrics(buildCtx, config, c.simpleOutput, buildStarted, files...)
+		defer met.Dump(soongMetricsFile)
+		defer build.DumpRBEMetrics(buildCtx, config, rbeMetricsFile)
+	}
 
 	// Read the time at the starting point.
 	if start, ok := os.LookupEnv("TRACE_BEGIN_SOONG"); ok {
@@ -513,3 +530,72 @@
 	// command not found
 	return nil, nil, fmt.Errorf("Command not found: %q", args)
 }
+
+// For Bazel support, this moves files and directories from e.g. out/dist/$f to DIST_DIR/$f if necessary.
+func populateExternalDistDir(ctx build.Context, config build.Config) {
+	// Make sure that internalDistDirPath and externalDistDirPath are both absolute paths, so we can compare them
+	var err error
+	var internalDistDirPath string
+	var externalDistDirPath string
+	if internalDistDirPath, err = filepath.Abs(config.DistDir()); err != nil {
+		ctx.Fatalf("Unable to find absolute path of %s: %s", internalDistDirPath, err)
+	}
+	if externalDistDirPath, err = filepath.Abs(config.RealDistDir()); err != nil {
+		ctx.Fatalf("Unable to find absolute path of %s: %s", externalDistDirPath, err)
+	}
+	if externalDistDirPath == internalDistDirPath {
+		return
+	}
+
+	// Make sure the external DIST_DIR actually exists before trying to write to it
+	if err = os.MkdirAll(externalDistDirPath, 0755); err != nil {
+		ctx.Fatalf("Unable to make directory %s: %s", externalDistDirPath, err)
+	}
+
+	ctx.Println("Populating external DIST_DIR...")
+
+	populateExternalDistDirHelper(ctx, config, internalDistDirPath, externalDistDirPath)
+}
+
+func populateExternalDistDirHelper(ctx build.Context, config build.Config, internalDistDirPath string, externalDistDirPath string) {
+	files, err := ioutil.ReadDir(internalDistDirPath)
+	if err != nil {
+		ctx.Fatalf("Can't read internal distdir %s: %s", internalDistDirPath, err)
+	}
+	for _, f := range files {
+		internalFilePath := filepath.Join(internalDistDirPath, f.Name())
+		externalFilePath := filepath.Join(externalDistDirPath, f.Name())
+
+		if f.IsDir() {
+			// Moving a directory - check if there is an existing directory to merge with
+			externalLstat, err := os.Lstat(externalFilePath)
+			if err != nil {
+				if !os.IsNotExist(err) {
+					ctx.Fatalf("Can't lstat external %s: %s", externalDistDirPath, err)
+				}
+				// Otherwise, if the error was os.IsNotExist, that's fine and we fall through to the rename at the bottom
+			} else {
+				if externalLstat.IsDir() {
+					// Existing dir - try to merge the directories?
+					populateExternalDistDirHelper(ctx, config, internalFilePath, externalFilePath)
+					continue
+				} else {
+					// Existing file being replaced with a directory. Delete the existing file...
+					if err := os.RemoveAll(externalFilePath); err != nil {
+						ctx.Fatalf("Unable to remove existing %s: %s", externalFilePath, err)
+					}
+				}
+			}
+		} else {
+			// Moving a file (not a dir) - delete any existing file or directory
+			if err := os.RemoveAll(externalFilePath); err != nil {
+				ctx.Fatalf("Unable to remove existing %s: %s", externalFilePath, err)
+			}
+		}
+
+		// The actual move - do a rename instead of a copy in order to save disk space.
+		if err := os.Rename(internalFilePath, externalFilePath); err != nil {
+			ctx.Fatalf("Unable to rename %s -> %s due to error %s", internalFilePath, externalFilePath, err)
+		}
+	}
+}
diff --git a/dexpreopt/class_loader_context.go b/dexpreopt/class_loader_context.go
index 3759217..deaf77f 100644
--- a/dexpreopt/class_loader_context.go
+++ b/dexpreopt/class_loader_context.go
@@ -437,7 +437,11 @@
 			if sdkVer == AnySdkVersion {
 				// Return error if dexpreopt doesn't know paths to one of the <uses-library>
 				// dependencies. In the future we may need to relax this and just disable dexpreopt.
-				return false, fmt.Errorf("invalid path for <uses-library> \"%s\"", clc.Name)
+				if clc.Host == nil {
+					return false, fmt.Errorf("invalid build path for <uses-library> \"%s\"", clc.Name)
+				} else {
+					return false, fmt.Errorf("invalid install path for <uses-library> \"%s\"", clc.Name)
+				}
 			} else {
 				// No error for compatibility libraries, as Soong doesn't know if they are needed
 				// (this depends on the targetSdkVersion in the manifest), but the CLC is invalid.
diff --git a/dexpreopt/class_loader_context_test.go b/dexpreopt/class_loader_context_test.go
index df68563..be7d4c6 100644
--- a/dexpreopt/class_loader_context_test.go
+++ b/dexpreopt/class_loader_context_test.go
@@ -195,7 +195,7 @@
 	// But class loader context in such cases should raise an error on validation.
 	t.Run("validate", func(t *testing.T) {
 		_, err := validateClassLoaderContext(m)
-		checkError(t, err, "invalid path for <uses-library> \"a\"")
+		checkError(t, err, "invalid build path for <uses-library> \"a\"")
 	})
 }
 
diff --git a/java/aar.go b/java/aar.go
index 1940d7f..3b6b34e 100644
--- a/java/aar.go
+++ b/java/aar.go
@@ -407,6 +407,7 @@
 
 	ctx.VisitDirectDeps(func(module android.Module) {
 		depName := ctx.OtherModuleName(module)
+		depTag := ctx.OtherModuleDependencyTag(module)
 
 		var exportPackage android.Path
 		aarDep, _ := module.(AndroidLibraryDependency)
@@ -414,7 +415,7 @@
 			exportPackage = aarDep.ExportPackage()
 		}
 
-		switch ctx.OtherModuleDependencyTag(module) {
+		switch depTag {
 		case instrumentationForTag:
 			// Nothing, instrumentationForTag is treated as libTag for javac but not for aapt2.
 		case libTag:
@@ -439,7 +440,6 @@
 				transitiveStaticLibs = append(transitiveStaticLibs, aarDep.ExportedStaticPackages()...)
 				transitiveStaticLibs = append(transitiveStaticLibs, exportPackage)
 				transitiveStaticLibManifests = append(transitiveStaticLibManifests, aarDep.ExportedManifests()...)
-				classLoaderContexts.AddContextMap(aarDep.ClassLoaderContexts(), depName)
 				if aarDep.ExportedAssets().Valid() {
 					assets = append(assets, aarDep.ExportedAssets().Path())
 				}
@@ -458,11 +458,8 @@
 			}
 		}
 
-		// Add nested dependencies after processing the direct dependency: if it is a <uses-library>,
-		// nested context is added as its subcontext, and should not be re-added at the top-level.
-		if dep, ok := module.(Dependency); ok {
-			classLoaderContexts.AddContextMap(dep.ClassLoaderContexts(), depName)
-		}
+		// Merge dep's CLC after processing the dep itself (which may add its own <uses-library>).
+		maybeAddCLCFromDep(module, depTag, depName, classLoaderContexts)
 	})
 
 	deps = append(deps, sharedLibs...)
diff --git a/java/androidmk.go b/java/androidmk.go
index fc573c8..aaad44f 100644
--- a/java/androidmk.go
+++ b/java/androidmk.go
@@ -274,7 +274,7 @@
 				},
 			},
 			ExtraFooters: []android.AndroidMkExtraFootersFunc{
-				func(w io.Writer, name, prefix, moduleDir string, entries *android.AndroidMkEntries) {
+				func(w io.Writer, name, prefix, moduleDir string) {
 					fmt.Fprintln(w, "jar_installed_module := $(LOCAL_INSTALLED_MODULE)")
 				},
 			},
@@ -289,7 +289,7 @@
 				},
 			},
 			ExtraFooters: []android.AndroidMkExtraFootersFunc{
-				func(w io.Writer, name, prefix, moduleDir string, entries *android.AndroidMkEntries) {
+				func(w io.Writer, name, prefix, moduleDir string) {
 					// Ensure that the wrapper script timestamp is always updated when the jar is updated
 					fmt.Fprintln(w, "$(LOCAL_INSTALLED_MODULE): $(jar_installed_module)")
 					fmt.Fprintln(w, "jar_installed_module :=")
@@ -393,7 +393,7 @@
 			},
 		},
 		ExtraFooters: []android.AndroidMkExtraFootersFunc{
-			func(w io.Writer, name, prefix, moduleDir string, entries *android.AndroidMkEntries) {
+			func(w io.Writer, name, prefix, moduleDir string) {
 				if app.noticeOutputs.Merged.Valid() {
 					fmt.Fprintf(w, "$(call dist-for-goals,%s,%s:%s)\n",
 						app.installApkName, app.noticeOutputs.Merged.String(), app.installApkName+"_NOTICE")
@@ -548,7 +548,7 @@
 			},
 		},
 		ExtraFooters: []android.AndroidMkExtraFootersFunc{
-			func(w io.Writer, name, prefix, moduleDir string, entries *android.AndroidMkEntries) {
+			func(w io.Writer, name, prefix, moduleDir string) {
 				if dstubs.apiFile != nil {
 					fmt.Fprintf(w, ".PHONY: %s %s.txt\n", dstubs.Name(), dstubs.Name())
 					fmt.Fprintf(w, "%s %s.txt: %s\n", dstubs.Name(), dstubs.Name(), dstubs.apiFile)
diff --git a/java/app.go b/java/app.go
index 4bf9d33..e6d9550 100755
--- a/java/app.go
+++ b/java/app.go
@@ -1400,6 +1400,13 @@
 	archProps := reflect.ValueOf(a.archVariants).Elem().FieldByName("Arch")
 	archType := ctx.Config().AndroidFirstDeviceTarget.Arch.ArchType
 	MergePropertiesFromVariant(ctx, &a.properties, archProps, archType.Name)
+
+	if String(a.properties.Apk) == "" {
+		// Disable this module since the apk property is still empty after processing all matching
+		// variants. This likely means there is no matching variant, and the default variant doesn't
+		// have an apk property value either.
+		a.Disable()
+	}
 }
 
 func MergePropertiesFromVariant(ctx android.EarlyModuleContext,
diff --git a/java/app_builder.go b/java/app_builder.go
index 69e462c..b53c15a 100644
--- a/java/app_builder.go
+++ b/java/app_builder.go
@@ -32,7 +32,7 @@
 var (
 	Signapk, SignapkRE = remoteexec.StaticRules(pctx, "signapk",
 		blueprint.RuleParams{
-			Command: `$reTemplate${config.JavaCmd} ${config.JavaVmFlags} -Djava.library.path=$$(dirname ${config.SignapkJniLibrary}) ` +
+			Command: `rm -f $out && $reTemplate${config.JavaCmd} ${config.JavaVmFlags} -Djava.library.path=$$(dirname ${config.SignapkJniLibrary}) ` +
 				`-jar ${config.SignapkCmd} $flags $certificates $in $out`,
 			CommandDeps: []string{"${config.SignapkCmd}", "${config.SignapkJniLibrary}"},
 		},
diff --git a/java/app_test.go b/java/app_test.go
index 6efb0dc..e13c6b9 100644
--- a/java/app_test.go
+++ b/java/app_test.go
@@ -2524,6 +2524,24 @@
 			`,
 			expected: "prebuilts/apk/app.apk",
 		},
+		{
+			name: "no matching arch without default",
+			bp: `
+				android_app_import {
+					name: "foo",
+					arch: {
+						arm: {
+							apk: "prebuilts/apk/app_arm.apk",
+						},
+					},
+					presigned: true,
+					dex_preopt: {
+						enabled: true,
+					},
+				}
+			`,
+			expected: "",
+		},
 	}
 
 	jniRuleRe := regexp.MustCompile("^if \\(zipinfo (\\S+)")
@@ -2531,6 +2549,12 @@
 		ctx, _ := testJava(t, test.bp)
 
 		variant := ctx.ModuleForTests("foo", "android_common")
+		if test.expected == "" {
+			if variant.Module().Enabled() {
+				t.Error("module should have been disabled, but wasn't")
+			}
+			continue
+		}
 		jniRuleCommand := variant.Output("jnis-uncompressed/foo.apk").RuleParams.Command
 		matches := jniRuleRe.FindStringSubmatch(jniRuleCommand)
 		if len(matches) != 2 {
@@ -2542,6 +2566,34 @@
 	}
 }
 
+func TestAndroidAppImport_overridesDisabledAndroidApp(t *testing.T) {
+	ctx, _ := testJava(t, `
+		android_app {
+			name: "foo",
+			srcs: ["a.java"],
+			enabled: false,
+		}
+ 
+ 		android_app_import {
+			name: "foo",
+			apk: "prebuilts/apk/app.apk",
+			certificate: "platform",
+			prefer: true,
+		}
+		`)
+
+	variant := ctx.ModuleForTests("prebuilt_foo", "android_common")
+	a := variant.Module().(*AndroidAppImport)
+	// The prebuilt module should still be enabled and active even if the source-based counterpart
+	// is disabled.
+	if !a.prebuilt.UsePrebuilt() {
+		t.Errorf("prebuilt foo module is not active")
+	}
+	if !a.Enabled() {
+		t.Errorf("prebuilt foo module is disabled")
+	}
+}
+
 func TestAndroidTestImport(t *testing.T) {
 	ctx, config := testJava(t, `
 		android_test_import {
@@ -2730,6 +2782,13 @@
 		}
 
 		java_sdk_library {
+			name: "fred",
+			srcs: ["a.java"],
+			api_packages: ["fred"],
+			sdk_version: "current",
+		}
+
+		java_sdk_library {
 			name: "bar",
 			srcs: ["a.java"],
 			api_packages: ["bar"],
@@ -2753,7 +2812,12 @@
 			name: "app",
 			srcs: ["a.java"],
 			libs: ["qux", "quuz.stubs"],
-			static_libs: ["static-runtime-helper"],
+			static_libs: [
+				"static-runtime-helper",
+				// statically linked component libraries should not pull their SDK libraries,
+				// so "fred" should not be added to class loader context
+				"fred.stubs",
+			],
 			uses_libs: ["foo"],
 			sdk_version: "current",
 			optional_uses_libs: [
diff --git a/java/builder.go b/java/builder.go
index cd35245..995160d 100644
--- a/java/builder.go
+++ b/java/builder.go
@@ -42,7 +42,7 @@
 	// TODO(b/143658984): goma can't handle the --system argument to javac.
 	javac, javacRE = remoteexec.MultiCommandStaticRules(pctx, "javac",
 		blueprint.RuleParams{
-			Command: `rm -rf "$outDir" "$annoDir" "$srcJarDir" && mkdir -p "$outDir" "$annoDir" "$srcJarDir" && ` +
+			Command: `rm -rf "$outDir" "$annoDir" "$srcJarDir" "$out" && mkdir -p "$outDir" "$annoDir" "$srcJarDir" && ` +
 				`${config.ZipSyncCmd} -d $srcJarDir -l $srcJarDir/list -f "*.java" $srcJars && ` +
 				`(if [ -s $srcJarDir/list ] || [ -s $out.rsp ] ; then ` +
 				`${config.SoongJavacWrapper} $javaTemplate${config.JavacCmd} ` +
diff --git a/java/dexpreopt_bootjars.go b/java/dexpreopt_bootjars.go
index f16ddf1..062005b 100644
--- a/java/dexpreopt_bootjars.go
+++ b/java/dexpreopt_bootjars.go
@@ -418,43 +418,53 @@
 	dumpOatRules(ctx, d.defaultBootImage)
 }
 
-func isHostdex(module android.Module) bool {
-	if lib, ok := module.(*Library); ok {
-		return Bool(lib.deviceProperties.Hostdex)
-	}
-	return false
-}
-
 // Inspect this module to see if it contains a bootclasspath dex jar.
 // Note that the same jar may occur in multiple modules.
 // This logic is tested in the apex package to avoid import cycle apex <-> java.
 func getBootImageJar(ctx android.SingletonContext, image *bootImageConfig, module android.Module) (int, android.Path) {
-	// All apex Java libraries have non-installable platform variants, skip them.
-	if module.IsSkipInstall() {
-		return -1, nil
-	}
-
-	jar, hasJar := module.(interface{ DexJarBuildPath() android.Path })
-	if !hasJar {
-		return -1, nil
-	}
-
+	// Ignore any module that is not listed in the boot image configuration.
 	name := ctx.ModuleName(module)
 	index := image.modules.IndexOfJar(name)
 	if index == -1 {
 		return -1, nil
 	}
 
-	// Check that this module satisfies constraints for a particular boot image.
-	_, isApexModule := module.(android.ApexModule)
+	// It is an error if a module configured in the boot image does not support
+	// accessing the dex jar. This is safe because every module that has the same
+	// name has to have the same module type.
+	jar, hasJar := module.(interface{ DexJarBuildPath() android.Path })
+	if !hasJar {
+		ctx.Errorf("module %q configured in boot image %q does not support accessing dex jar", module, image.name)
+		return -1, nil
+	}
+
+	// It is also an error if the module is not an ApexModule.
+	if _, ok := module.(android.ApexModule); !ok {
+		ctx.Errorf("module %q configured in boot image %q does not support being added to an apex", module, image.name)
+		return -1, nil
+	}
+
 	apexInfo := ctx.ModuleProvider(module, android.ApexInfoProvider).(android.ApexInfo)
-	fromUpdatableApex := isApexModule && apexInfo.Updatable
-	if image.name == artBootImageName {
-		if isApexModule && len(apexInfo.InApexes) > 0 && allHavePrefix(apexInfo.InApexes, "com.android.art") {
-			// ok: found the jar in the ART apex
-		} else if isApexModule && apexInfo.IsForPlatform() && isHostdex(module) {
-			// exception (skip and continue): special "hostdex" platform variant
+
+	// Now match the apex part of the boot image configuration.
+	requiredApex := image.modules.Apex(index)
+	if requiredApex == "platform" {
+		if len(apexInfo.InApexes) != 0 {
+			// A platform variant is required but this is for an apex so ignore it.
 			return -1, nil
+		}
+	} else if !android.InList(requiredApex, apexInfo.InApexes) {
+		// An apex variant for a specific apex is required but this is the wrong apex.
+		return -1, nil
+	}
+
+	// Check that this module satisfies any boot image specific constraints.
+	fromUpdatableApex := apexInfo.Updatable
+
+	switch image.name {
+	case artBootImageName:
+		if len(apexInfo.InApexes) > 0 && allHavePrefix(apexInfo.InApexes, "com.android.art") {
+			// ok: found the jar in the ART apex
 		} else if name == "jacocoagent" && ctx.Config().IsEnvTrue("EMMA_INSTRUMENT_FRAMEWORK") {
 			// exception (skip and continue): Jacoco platform variant for a coverage build
 			return -1, nil
@@ -465,14 +475,15 @@
 			// error: this jar is part of the platform or a non-updatable apex
 			ctx.Errorf("module %q is not allowed in the ART boot image", name)
 		}
-	} else if image.name == frameworkBootImageName {
+
+	case frameworkBootImageName:
 		if !fromUpdatableApex {
 			// ok: this jar is part of the platform or a non-updatable apex
 		} else {
 			// error: this jar is part of an updatable apex
 			ctx.Errorf("module %q from updatable apexes %q is not allowed in the framework boot image", name, apexInfo.InApexes)
 		}
-	} else {
+	default:
 		panic("unknown boot image: " + image.name)
 	}
 
@@ -495,6 +506,12 @@
 	bootDexJars := make(android.Paths, image.modules.Len())
 	ctx.VisitAllModules(func(module android.Module) {
 		if i, j := getBootImageJar(ctx, image, module); i != -1 {
+			if existing := bootDexJars[i]; existing != nil {
+				ctx.Errorf("Multiple dex jars found for %s:%s - %s and %s",
+					image.modules.Apex(i), image.modules.Jar(i), existing, j)
+				return
+			}
+
 			bootDexJars[i] = j
 		}
 	})
@@ -506,7 +523,7 @@
 			m := image.modules.Jar(i)
 			if ctx.Config().AllowMissingDependencies() {
 				missingDeps = append(missingDeps, m)
-				bootDexJars[i] = android.PathForOutput(ctx, "missing")
+				bootDexJars[i] = android.PathForOutput(ctx, "missing/module", m, "from/apex", image.modules.Apex(i))
 			} else {
 				ctx.Errorf("failed to find a dex jar path for module '%s'"+
 					", note that some jars may be filtered out by module constraints", m)
@@ -779,7 +796,7 @@
 			bootFrameworkProfile = path.Path()
 		} else {
 			missingDeps = append(missingDeps, defaultProfile)
-			bootFrameworkProfile = android.PathForOutput(ctx, "missing")
+			bootFrameworkProfile = android.PathForOutput(ctx, "missing", defaultProfile)
 		}
 
 		profile := image.dir.Join(ctx, "boot.bprof")
diff --git a/java/hiddenapi_singleton.go b/java/hiddenapi_singleton.go
index ce8410e..419dc34 100644
--- a/java/hiddenapi_singleton.go
+++ b/java/hiddenapi_singleton.go
@@ -177,12 +177,13 @@
 	for moduleList, pathList := range moduleListToPathList {
 		for i := range pathList {
 			if pathList[i] == nil {
-				pathList[i] = android.PathForOutput(ctx, "missing")
+				moduleName := (*moduleList)[i]
+				pathList[i] = android.PathForOutput(ctx, "missing/module", moduleName)
 				if ctx.Config().AllowMissingDependencies() {
-					missingDeps = append(missingDeps, (*moduleList)[i])
+					missingDeps = append(missingDeps, moduleName)
 				} else {
 					ctx.Errorf("failed to find dex jar path for module %q",
-						(*moduleList)[i])
+						moduleName)
 				}
 			}
 		}
diff --git a/java/java.go b/java/java.go
index 3d121cc..d44719e 100644
--- a/java/java.go
+++ b/java/java.go
@@ -1081,7 +1081,6 @@
 			switch tag {
 			case libTag:
 				deps.classpath = append(deps.classpath, dep.SdkHeaderJars(ctx, j.sdkVersion())...)
-				// names of sdk libs that are directly depended are exported
 				j.classLoaderContexts.MaybeAddContext(ctx, dep.OptionalImplicitSdkLibrary(),
 					dep.DexJarBuildPath(), dep.DexJarInstallPath())
 			case staticLibTag:
@@ -1093,7 +1092,6 @@
 				deps.bootClasspath = append(deps.bootClasspath, dep.HeaderJars()...)
 			case libTag, instrumentationForTag:
 				deps.classpath = append(deps.classpath, dep.HeaderJars()...)
-				// sdk lib names from dependencies are re-exported
 				j.classLoaderContexts.AddContextMap(dep.ClassLoaderContexts(), otherName)
 				deps.aidlIncludeDirs = append(deps.aidlIncludeDirs, dep.AidlIncludeDirs()...)
 				pluginJars, pluginClasses, disableTurbine := dep.ExportedPlugins()
@@ -1106,8 +1104,6 @@
 				deps.staticJars = append(deps.staticJars, dep.ImplementationJars()...)
 				deps.staticHeaderJars = append(deps.staticHeaderJars, dep.HeaderJars()...)
 				deps.staticResourceJars = append(deps.staticResourceJars, dep.ResourceJars()...)
-				// sdk lib names from dependencies are re-exported
-				j.classLoaderContexts.AddContextMap(dep.ClassLoaderContexts(), otherName)
 				deps.aidlIncludeDirs = append(deps.aidlIncludeDirs, dep.AidlIncludeDirs()...)
 				pluginJars, pluginClasses, disableTurbine := dep.ExportedPlugins()
 				addPlugins(&deps, pluginJars, pluginClasses...)
@@ -1182,6 +1178,9 @@
 				deps.systemModules = &systemModules{outputDir, outputDeps}
 			}
 		}
+
+		// Merge dep's CLC after processing the dep itself (which may add its own <uses-library>).
+		maybeAddCLCFromDep(module, tag, otherName, j.classLoaderContexts)
 	})
 
 	return deps
@@ -2815,8 +2814,6 @@
 			switch tag {
 			case libTag, staticLibTag:
 				flags.classpath = append(flags.classpath, dep.HeaderJars()...)
-				// sdk lib names from dependencies are re-exported
-				j.classLoaderContexts.AddContextMap(dep.ClassLoaderContexts(), otherName)
 			case bootClasspathTag:
 				flags.bootClasspath = append(flags.bootClasspath, dep.HeaderJars()...)
 			}
@@ -2824,10 +2821,12 @@
 			switch tag {
 			case libTag:
 				flags.classpath = append(flags.classpath, dep.SdkHeaderJars(ctx, j.sdkVersion())...)
-				// names of sdk libs that are directly depended are exported
 				j.classLoaderContexts.AddContext(ctx, otherName, dep.DexJarBuildPath(), dep.DexJarInstallPath())
 			}
 		}
+
+		// Merge dep's CLC after processing the dep itself (which may add its own <uses-library>).
+		maybeAddCLCFromDep(module, tag, otherName, j.classLoaderContexts)
 	})
 
 	var installFile android.Path
@@ -3248,3 +3247,31 @@
 var BoolDefault = proptools.BoolDefault
 var String = proptools.String
 var inList = android.InList
+
+// Add class loader context of a given dependency to the given class loader context, provided that
+// all the necessary conditions are met.
+func maybeAddCLCFromDep(depModule android.Module, depTag blueprint.DependencyTag,
+	depName string, clcMap dexpreopt.ClassLoaderContextMap) {
+
+	if dep, ok := depModule.(Dependency); ok {
+		if depTag == libTag {
+			// Ok, propagate <uses-library> through non-static library dependencies.
+		} else if depTag == staticLibTag {
+			// Propagate <uses-library> through static library dependencies, unless it is a
+			// component library (such as stubs). Component libraries have a dependency on their
+			// SDK library, which should not be pulled just because of a static component library.
+			if comp, isComp := depModule.(SdkLibraryComponentDependency); isComp {
+				if compName := comp.OptionalImplicitSdkLibrary(); compName != nil {
+					dep = nil
+				}
+			}
+		} else {
+			// Don't propagate <uses-library> for other dependency tags.
+			dep = nil
+		}
+
+		if dep != nil {
+			clcMap.AddContextMap(dep.ClassLoaderContexts(), depName)
+		}
+	}
+}
diff --git a/java/robolectric.go b/java/robolectric.go
index 419efda..c821e5b 100644
--- a/java/robolectric.go
+++ b/java/robolectric.go
@@ -260,7 +260,7 @@
 	entries := &entriesList[0]
 
 	entries.ExtraFooters = []android.AndroidMkExtraFootersFunc{
-		func(w io.Writer, name, prefix, moduleDir string, entries *android.AndroidMkEntries) {
+		func(w io.Writer, name, prefix, moduleDir string) {
 			if s := r.robolectricProperties.Test_options.Shards; s != nil && *s > 1 {
 				numShards := int(*s)
 				shardSize := (len(r.tests) + numShards - 1) / numShards
diff --git a/rust/binary.go b/rust/binary.go
index af39d38..c2d97f3 100644
--- a/rust/binary.go
+++ b/rust/binary.go
@@ -24,11 +24,6 @@
 }
 
 type BinaryCompilerProperties struct {
-	// Change the rustlibs linkage to select rlib linkage by default for device targets.
-	// Also link libstd as an rlib as well on device targets.
-	// Note: This is the default behavior for host targets.
-	Prefer_rlib *bool `android:"arch_variant"`
-
 	// Builds this binary as a static binary. Implies prefer_rlib true.
 	//
 	// Static executables currently only support for bionic targets. Non-bionic targets will not produce a fully static
@@ -115,7 +110,7 @@
 }
 
 func (binary *binaryDecorator) preferRlib() bool {
-	return Bool(binary.Properties.Prefer_rlib) || Bool(binary.Properties.Static_executable)
+	return Bool(binary.baseCompiler.Properties.Prefer_rlib) || Bool(binary.Properties.Static_executable)
 }
 
 func (binary *binaryDecorator) compile(ctx ModuleContext, flags Flags, deps PathDeps) android.Path {
@@ -156,8 +151,7 @@
 	// Binaries default to dylib dependencies for device, rlib for host.
 	if binary.preferRlib() {
 		return rlibAutoDep
-	}
-	if ctx.Device() {
+	} else if ctx.Device() {
 		return dylibAutoDep
 	} else {
 		return rlibAutoDep
diff --git a/rust/compiler.go b/rust/compiler.go
index 8d2f09c..4312452 100644
--- a/rust/compiler.go
+++ b/rust/compiler.go
@@ -122,6 +122,17 @@
 
 	// whether to suppress inclusion of standard crates - defaults to false
 	No_stdlibs *bool
+
+	// Change the rustlibs linkage to select rlib linkage by default for device targets.
+	// Also link libstd as an rlib as well on device targets.
+	// Note: This is the default behavior for host targets.
+	//
+	// This is primarily meant for rust_binary and rust_ffi modules where the default
+	// linkage of libstd might need to be overridden in some use cases. This should
+	// generally be avoided with other module types since it may cause collisions at
+	// linkage if all dependencies of the root binary module do not link against libstd\
+	// the same way.
+	Prefer_rlib *bool `android:"arch_variant"`
 }
 
 type baseCompiler struct {
@@ -154,9 +165,15 @@
 	panic("baseCompiler does not implement coverageOutputZipPath()")
 }
 
+func (compiler *baseCompiler) preferRlib() bool {
+	return Bool(compiler.Properties.Prefer_rlib)
+}
+
 func (compiler *baseCompiler) stdLinkage(ctx *depsContext) RustLinkage {
 	// For devices, we always link stdlibs in as dylibs by default.
-	if ctx.Device() {
+	if compiler.preferRlib() {
+		return RlibLinkage
+	} else if ctx.Device() {
 		return DylibLinkage
 	} else {
 		return RlibLinkage
diff --git a/rust/config/Android.bp b/rust/config/Android.bp
index e0cc4ce..1f0109f 100644
--- a/rust/config/Android.bp
+++ b/rust/config/Android.bp
@@ -13,6 +13,7 @@
         "toolchain.go",
         "allowed_list.go",
         "x86_darwin_host.go",
+        "x86_linux_bionic_host.go",
         "x86_linux_host.go",
         "x86_device.go",
         "x86_64_device.go",
diff --git a/rust/config/allowed_list.go b/rust/config/allowed_list.go
index e6643f5..df31d60 100644
--- a/rust/config/allowed_list.go
+++ b/rust/config/allowed_list.go
@@ -13,6 +13,7 @@
 		"external/rust",
 		"external/vm_tools/p9",
 		"frameworks/native/libs/binder/rust",
+		"packages/modules/DnsResolver",
 		"packages/modules/Virtualization",
 		"prebuilts/rust",
 		"system/bt",
diff --git a/rust/config/x86_linux_bionic_host.go b/rust/config/x86_linux_bionic_host.go
new file mode 100644
index 0000000..b1a2c17
--- /dev/null
+++ b/rust/config/x86_linux_bionic_host.go
@@ -0,0 +1,73 @@
+// Copyright 2020 The Android Open Source Project
+//
+// 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 config
+
+import (
+	"strings"
+
+	"android/soong/android"
+)
+
+var (
+	LinuxBionicRustFlags     = []string{}
+	LinuxBionicRustLinkFlags = []string{
+		"-B${cc_config.ClangBin}",
+		"-fuse-ld=lld",
+		"-Wl,--undefined-version",
+		"-nostdlib",
+	}
+)
+
+func init() {
+	registerToolchainFactory(android.LinuxBionic, android.X86_64, linuxBionicX8664ToolchainFactory)
+
+	pctx.StaticVariable("LinuxBionicToolchainRustFlags", strings.Join(LinuxBionicRustFlags, " "))
+	pctx.StaticVariable("LinuxBionicToolchainLinkFlags", strings.Join(LinuxBionicRustLinkFlags, " "))
+}
+
+type toolchainLinuxBionicX8664 struct {
+	toolchain64Bit
+}
+
+func (toolchainLinuxBionicX8664) Supported() bool {
+	return true
+}
+
+func (toolchainLinuxBionicX8664) Bionic() bool {
+	return true
+}
+
+func (t *toolchainLinuxBionicX8664) Name() string {
+	return "x86_64"
+}
+
+func (t *toolchainLinuxBionicX8664) RustTriple() string {
+	return "x86_64-linux-android"
+}
+
+func (t *toolchainLinuxBionicX8664) ToolchainLinkFlags() string {
+	// Prepend the lld flags from cc_config so we stay in sync with cc
+	return "${cc_config.LinuxBionicLldflags} ${config.LinuxBionicToolchainLinkFlags}"
+}
+
+func (t *toolchainLinuxBionicX8664) ToolchainRustFlags() string {
+	return "${config.LinuxBionicToolchainRustFlags}"
+}
+
+func linuxBionicX8664ToolchainFactory(arch android.Arch) Toolchain {
+	return toolchainLinuxBionicX8664Singleton
+}
+
+var toolchainLinuxBionicX8664Singleton Toolchain = &toolchainLinuxBionicX8664{}
diff --git a/rust/library.go b/rust/library.go
index 971588d..9d731e6 100644
--- a/rust/library.go
+++ b/rust/library.go
@@ -159,14 +159,6 @@
 	return library.MutatedProperties.VariantIsStatic
 }
 
-func (library *libraryDecorator) stdLinkage(ctx *depsContext) RustLinkage {
-	// libraries should only request the RlibLinkage when building a static FFI or when variant is StaticStd
-	if library.static() || library.MutatedProperties.VariantIsStaticStd {
-		return RlibLinkage
-	}
-	return DefaultLinkage
-}
-
 func (library *libraryDecorator) source() bool {
 	return library.MutatedProperties.VariantIsSource
 }
@@ -228,7 +220,9 @@
 }
 
 func (library *libraryDecorator) autoDep(ctx BaseModuleContext) autoDep {
-	if library.rlib() || library.static() {
+	if library.preferRlib() {
+		return rlibAutoDep
+	} else if library.rlib() || library.static() {
 		return rlibAutoDep
 	} else if library.dylib() || library.shared() {
 		return dylibAutoDep
@@ -237,6 +231,15 @@
 	}
 }
 
+func (library *libraryDecorator) stdLinkage(ctx *depsContext) RustLinkage {
+	if library.static() || library.MutatedProperties.VariantIsStaticStd {
+		return RlibLinkage
+	} else if library.baseCompiler.preferRlib() {
+		return RlibLinkage
+	}
+	return DefaultLinkage
+}
+
 var _ compiler = (*libraryDecorator)(nil)
 var _ libraryInterface = (*libraryDecorator)(nil)
 var _ exportedFlagsProducer = (*libraryDecorator)(nil)
diff --git a/rust/library_test.go b/rust/library_test.go
index fec3992..54cd2a5 100644
--- a/rust/library_test.go
+++ b/rust/library_test.go
@@ -251,6 +251,13 @@
 			srcs: ["foo.rs"],
 			crate_name: "bar",
 			rustlibs: ["libfoo"],
+		}
+		rust_ffi {
+			name: "libbar.prefer_rlib",
+			srcs: ["foo.rs"],
+			crate_name: "bar",
+			rustlibs: ["libfoo"],
+			prefer_rlib: true,
 		}`)
 
 	libfooDylib := ctx.ModuleForTests("libfoo", "android_arm64_armv8-a_dylib").Module().(*Module)
@@ -260,6 +267,9 @@
 	libbarShared := ctx.ModuleForTests("libbar", "android_arm64_armv8-a_shared").Module().(*Module)
 	libbarStatic := ctx.ModuleForTests("libbar", "android_arm64_armv8-a_static").Module().(*Module)
 
+	// prefer_rlib works the same for both rust_library and rust_ffi, so a single check is sufficient here.
+	libbarRlibStd := ctx.ModuleForTests("libbar.prefer_rlib", "android_arm64_armv8-a_shared").Module().(*Module)
+
 	if !android.InList("libstd", libfooRlibStatic.Properties.AndroidMkRlibs) {
 		t.Errorf("rlib-std variant for device rust_library_rlib does not link libstd as an rlib")
 	}
@@ -279,4 +289,8 @@
 	if !android.InList("libfoo.rlib-std", libbarStatic.Properties.AndroidMkRlibs) {
 		t.Errorf("Device rust_ffi_static does not link dependent rustlib rlib-std variant")
 	}
+	if !android.InList("libstd", libbarRlibStd.Properties.AndroidMkRlibs) {
+		t.Errorf("rust_ffi with prefer_rlib does not link libstd as an rlib")
+	}
+
 }
diff --git a/rust/project_json.go b/rust/project_json.go
index c4d60ad..32ce6f4 100644
--- a/rust/project_json.go
+++ b/rust/project_json.go
@@ -45,10 +45,11 @@
 }
 
 type rustProjectCrate struct {
-	RootModule string           `json:"root_module"`
-	Edition    string           `json:"edition,omitempty"`
-	Deps       []rustProjectDep `json:"deps"`
-	Cfgs       []string         `json:"cfgs"`
+	DisplayName string           `json:"display_name"`
+	RootModule  string           `json:"root_module"`
+	Edition     string           `json:"edition,omitempty"`
+	Deps        []rustProjectDep `json:"deps"`
+	Cfgs        []string         `json:"cfgs"`
 }
 
 type rustProjectJson struct {
@@ -58,13 +59,13 @@
 
 // crateInfo is used during the processing to keep track of the known crates.
 type crateInfo struct {
-	ID   int
-	Deps map[string]int
+	Idx  int            // Index of the crate in rustProjectJson.Crates slice.
+	Deps map[string]int // The keys are the module names and not the crate names.
 }
 
 type projectGeneratorSingleton struct {
 	project     rustProjectJson
-	knownCrates map[string]crateInfo
+	knownCrates map[string]crateInfo // Keys are module names.
 }
 
 func rustProjectGeneratorSingleton() android.Singleton {
@@ -75,66 +76,129 @@
 	android.RegisterSingletonType("rust_project_generator", rustProjectGeneratorSingleton)
 }
 
-// crateSource finds the main source file (.rs) for a crate.
-func crateSource(ctx android.SingletonContext, rModule *Module, comp *baseCompiler) (string, bool) {
-	srcs := comp.Properties.Srcs
-	if len(srcs) != 0 {
-		return path.Join(ctx.ModuleDir(rModule), srcs[0]), true
-	}
+// sourceProviderVariantSource returns the path to the source file if this
+// module variant should be used as a priority.
+//
+// SourceProvider modules may have multiple variants considered as source
+// (e.g., x86_64 and armv8). For a module available on device, use the source
+// generated for the target. For a host-only module, use the source generated
+// for the host.
+func sourceProviderVariantSource(ctx android.SingletonContext, rModule *Module) (string, bool) {
 	rustLib, ok := rModule.compiler.(*libraryDecorator)
 	if !ok {
 		return "", false
 	}
-	if !rustLib.source() {
-		return "", false
-	}
-	// It is a SourceProvider module. If this module is host only, uses the variation for the host.
-	// Otherwise, use the variation for the primary target.
-	switch rModule.hod {
-	case android.HostSupported:
-	case android.HostSupportedNoCross:
-		if rModule.Target().String() != ctx.Config().BuildOSTarget.String() {
-			return "", false
-		}
-	default:
-		if rModule.Target().String() != ctx.Config().AndroidFirstDeviceTarget.String() {
-			return "", false
+	if rustLib.source() {
+		switch rModule.hod {
+		case android.HostSupported, android.HostSupportedNoCross:
+			if rModule.Target().String() == ctx.Config().BuildOSTarget.String() {
+				src := rustLib.sourceProvider.Srcs()[0]
+				return src.String(), true
+			}
+		default:
+			if rModule.Target().String() == ctx.Config().AndroidFirstDeviceTarget.String() {
+				src := rustLib.sourceProvider.Srcs()[0]
+				return src.String(), true
+			}
 		}
 	}
-	src := rustLib.sourceProvider.Srcs()[0]
-	return src.String(), true
+	return "", false
 }
 
-func (singleton *projectGeneratorSingleton) mergeDependencies(ctx android.SingletonContext,
-	module android.Module, crate *rustProjectCrate, deps map[string]int) {
-
-	ctx.VisitDirectDeps(module, func(child android.Module) {
-		childId, childCrateName, ok := singleton.appendLibraryAndDeps(ctx, child)
-		if !ok {
+// sourceProviderSource finds the main source file of a source-provider crate.
+func sourceProviderSource(ctx android.SingletonContext, rModule *Module) (string, bool) {
+	rustLib, ok := rModule.compiler.(*libraryDecorator)
+	if !ok {
+		return "", false
+	}
+	if rustLib.source() {
+		// This is a source-variant, check if we are the right variant
+		// depending on the module configuration.
+		if src, ok := sourceProviderVariantSource(ctx, rModule); ok {
+			return src, true
+		}
+	}
+	foundSource := false
+	sourceSrc := ""
+	// Find the variant with the source and return its.
+	ctx.VisitAllModuleVariants(rModule, func(variant android.Module) {
+		if foundSource {
 			return
 		}
+		// All variants of a source provider library are libraries.
+		rVariant, _ := variant.(*Module)
+		variantLib, _ := rVariant.compiler.(*libraryDecorator)
+		if variantLib.source() {
+			sourceSrc, ok = sourceProviderVariantSource(ctx, rVariant)
+			if ok {
+				foundSource = true
+			}
+		}
+	})
+	if !foundSource {
+		fmt.Errorf("No valid source for source provider found: %v\n", rModule)
+	}
+	return sourceSrc, foundSource
+}
+
+// crateSource finds the main source file (.rs) for a crate.
+func crateSource(ctx android.SingletonContext, rModule *Module, comp *baseCompiler) (string, bool) {
+	// Basic libraries, executables and tests.
+	srcs := comp.Properties.Srcs
+	if len(srcs) != 0 {
+		return path.Join(ctx.ModuleDir(rModule), srcs[0]), true
+	}
+	// SourceProvider libraries.
+	if rModule.sourceProvider != nil {
+		return sourceProviderSource(ctx, rModule)
+	}
+	return "", false
+}
+
+// mergeDependencies visits all the dependencies for module and updates crate and deps
+// with any new dependency.
+func (singleton *projectGeneratorSingleton) mergeDependencies(ctx android.SingletonContext,
+	module *Module, crate *rustProjectCrate, deps map[string]int) {
+
+	ctx.VisitDirectDeps(module, func(child android.Module) {
 		// Skip intra-module dependencies (i.e., generated-source library depending on the source variant).
 		if module.Name() == child.Name() {
 			return
 		}
-		if _, ok = deps[ctx.ModuleName(child)]; ok {
+		// Skip unsupported modules.
+		rChild, compChild, ok := isModuleSupported(ctx, child)
+		if !ok {
 			return
 		}
-		crate.Deps = append(crate.Deps, rustProjectDep{Crate: childId, Name: childCrateName})
-		deps[ctx.ModuleName(child)] = childId
+		// For unknown dependency, add it first.
+		var childId int
+		cInfo, known := singleton.knownCrates[rChild.Name()]
+		if !known {
+			childId, ok = singleton.addCrate(ctx, rChild, compChild)
+			if !ok {
+				return
+			}
+		} else {
+			childId = cInfo.Idx
+		}
+		// Is this dependency known already?
+		if _, ok = deps[child.Name()]; ok {
+			return
+		}
+		crate.Deps = append(crate.Deps, rustProjectDep{Crate: childId, Name: rChild.CrateName()})
+		deps[child.Name()] = childId
 	})
 }
 
-// appendLibraryAndDeps creates a rustProjectCrate for the module argument and appends it to singleton.project.
-// It visits the dependencies of the module depth-first so the dependency ID can be added to the current module. If the
-// current module is already in singleton.knownCrates, its dependencies are merged. Returns a tuple (id, crate_name, ok).
-func (singleton *projectGeneratorSingleton) appendLibraryAndDeps(ctx android.SingletonContext, module android.Module) (int, string, bool) {
+// isModuleSupported returns the RustModule and baseCompiler if the module
+// should be considered for inclusion in rust-project.json.
+func isModuleSupported(ctx android.SingletonContext, module android.Module) (*Module, *baseCompiler, bool) {
 	rModule, ok := module.(*Module)
 	if !ok {
-		return 0, "", false
+		return nil, nil, false
 	}
 	if rModule.compiler == nil {
-		return 0, "", false
+		return nil, nil, false
 	}
 	var comp *baseCompiler
 	switch c := rModule.compiler.(type) {
@@ -145,35 +209,57 @@
 	case *testDecorator:
 		comp = c.binaryDecorator.baseCompiler
 	default:
-		return 0, "", false
+		return nil, nil, false
 	}
-	moduleName := ctx.ModuleName(module)
-	crateName := rModule.CrateName()
-	if cInfo, ok := singleton.knownCrates[moduleName]; ok {
-		// We have seen this crate already; merge any new dependencies.
-		crate := singleton.project.Crates[cInfo.ID]
-		singleton.mergeDependencies(ctx, module, &crate, cInfo.Deps)
-		singleton.project.Crates[cInfo.ID] = crate
-		return cInfo.ID, crateName, true
-	}
-	crate := rustProjectCrate{Deps: make([]rustProjectDep, 0), Cfgs: make([]string, 0)}
+	return rModule, comp, true
+}
+
+// addCrate adds a crate to singleton.project.Crates ensuring that required
+// dependencies are also added. It returns the index of the new crate in
+// singleton.project.Crates
+func (singleton *projectGeneratorSingleton) addCrate(ctx android.SingletonContext, rModule *Module, comp *baseCompiler) (int, bool) {
 	rootModule, ok := crateSource(ctx, rModule, comp)
 	if !ok {
-		return 0, "", false
+		fmt.Errorf("Unable to find source for valid module: %v", rModule)
+		return 0, false
 	}
-	crate.RootModule = rootModule
-	crate.Edition = comp.edition()
+
+	crate := rustProjectCrate{
+		DisplayName: rModule.Name(),
+		RootModule:  rootModule,
+		Edition:     comp.edition(),
+		Deps:        make([]rustProjectDep, 0),
+		Cfgs:        make([]string, 0),
+	}
 
 	deps := make(map[string]int)
-	singleton.mergeDependencies(ctx, module, &crate, deps)
+	singleton.mergeDependencies(ctx, rModule, &crate, deps)
 
-	id := len(singleton.project.Crates)
-	singleton.knownCrates[moduleName] = crateInfo{ID: id, Deps: deps}
+	idx := len(singleton.project.Crates)
+	singleton.knownCrates[rModule.Name()] = crateInfo{Idx: idx, Deps: deps}
 	singleton.project.Crates = append(singleton.project.Crates, crate)
 	// rust-analyzer requires that all crates belong to at least one root:
 	// https://github.com/rust-analyzer/rust-analyzer/issues/4735.
 	singleton.project.Roots = append(singleton.project.Roots, path.Dir(crate.RootModule))
-	return id, crateName, true
+	return idx, true
+}
+
+// appendCrateAndDependencies creates a rustProjectCrate for the module argument and appends it to singleton.project.
+// It visits the dependencies of the module depth-first so the dependency ID can be added to the current module. If the
+// current module is already in singleton.knownCrates, its dependencies are merged.
+func (singleton *projectGeneratorSingleton) appendCrateAndDependencies(ctx android.SingletonContext, module android.Module) {
+	rModule, comp, ok := isModuleSupported(ctx, module)
+	if !ok {
+		return
+	}
+	// If we have seen this crate already; merge any new dependencies.
+	if cInfo, ok := singleton.knownCrates[module.Name()]; ok {
+		crate := singleton.project.Crates[cInfo.Idx]
+		singleton.mergeDependencies(ctx, rModule, &crate, cInfo.Deps)
+		singleton.project.Crates[cInfo.Idx] = crate
+		return
+	}
+	singleton.addCrate(ctx, rModule, comp)
 }
 
 func (singleton *projectGeneratorSingleton) GenerateBuildActions(ctx android.SingletonContext) {
@@ -183,7 +269,7 @@
 
 	singleton.knownCrates = make(map[string]crateInfo)
 	ctx.VisitAllModules(func(module android.Module) {
-		singleton.appendLibraryAndDeps(ctx, module)
+		singleton.appendCrateAndDependencies(ctx, module)
 	})
 
 	path := android.PathForOutput(ctx, rustProjectJsonFileName)
diff --git a/rust/project_json_test.go b/rust/project_json_test.go
index aff1697..ba66215 100644
--- a/rust/project_json_test.go
+++ b/rust/project_json_test.go
@@ -119,9 +119,9 @@
 func TestProjectJsonBinary(t *testing.T) {
 	bp := `
 	rust_binary {
-		name: "liba",
-		srcs: ["a/src/lib.rs"],
-		crate_name: "a"
+		name: "libz",
+		srcs: ["z/src/lib.rs"],
+		crate_name: "z"
 	}
 	`
 	jsonContent := testProjectJson(t, bp)
@@ -132,7 +132,7 @@
 		if !ok {
 			t.Fatalf("Unexpected type for root_module: %v", crate["root_module"])
 		}
-		if rootModule == "a/src/lib.rs" {
+		if rootModule == "z/src/lib.rs" {
 			return
 		}
 	}
@@ -142,10 +142,10 @@
 func TestProjectJsonBindGen(t *testing.T) {
 	bp := `
 	rust_library {
-		name: "liba",
-		srcs: ["src/lib.rs"],
+		name: "libd",
+		srcs: ["d/src/lib.rs"],
 		rlibs: ["libbindings1"],
-		crate_name: "a"
+		crate_name: "d"
 	}
 	rust_bindgen {
 		name: "libbindings1",
@@ -155,10 +155,10 @@
 		wrapper_src: "src/any.h",
 	}
 	rust_library_host {
-		name: "libb",
-		srcs: ["src/lib.rs"],
+		name: "libe",
+		srcs: ["e/src/lib.rs"],
 		rustlibs: ["libbindings2"],
-		crate_name: "b"
+		crate_name: "e"
 	}
 	rust_bindgen_host {
 		name: "libbindings2",
@@ -190,6 +190,19 @@
 				}
 			}
 		}
+		// Check that liba depends on libbindings1
+		if strings.Contains(rootModule, "d/src/lib.rs") {
+			found := false
+			for _, depName := range validateDependencies(t, crate) {
+				if depName == "bindings1" {
+					found = true
+					break
+				}
+			}
+			if !found {
+				t.Errorf("liba does not depend on libbindings1: %v", crate)
+			}
+		}
 	}
 }
 
diff --git a/rust/rust.go b/rust/rust.go
index 4094094..c1388d5 100644
--- a/rust/rust.go
+++ b/rust/rust.go
@@ -67,6 +67,9 @@
 
 	SubName string `blueprint:"mutated"`
 
+	// Minimum sdk version that the artifact should support when it runs as part of mainline modules(APEX).
+	Min_sdk_version *string
+
 	PreventInstall bool
 	HideFromMake   bool
 }
@@ -1088,7 +1091,29 @@
 
 var _ android.ApexModule = (*Module)(nil)
 
+func (mod *Module) minSdkVersion() string {
+	return String(mod.Properties.Min_sdk_version)
+}
+
 func (mod *Module) ShouldSupportSdkVersion(ctx android.BaseModuleContext, sdkVersion android.ApiLevel) error {
+	minSdkVersion := mod.minSdkVersion()
+	if minSdkVersion == "apex_inherit" {
+		return nil
+	}
+	if minSdkVersion == "" {
+		return fmt.Errorf("min_sdk_version is not specificed")
+	}
+
+	// Not using nativeApiLevelFromUser because the context here is not
+	// necessarily a native context.
+	ver, err := android.ApiLevelFromUser(ctx, minSdkVersion)
+	if err != nil {
+		return err
+	}
+
+	if ver.GreaterThan(sdkVersion) {
+		return fmt.Errorf("newer SDK(%v)", ver)
+	}
 	return nil
 }
 
diff --git a/rust/testing.go b/rust/testing.go
index a8496d9..8648dc3 100644
--- a/rust/testing.go
+++ b/rust/testing.go
@@ -78,6 +78,7 @@
 			nocrt: true,
 			system_shared_libs: [],
 			apex_available: ["//apex_available:platform", "//apex_available:anyapex"],
+			min_sdk_version: "29",
 		}
 		cc_library {
 			name: "libprotobuf-cpp-full",
@@ -95,6 +96,7 @@
                         native_coverage: false,
 			sysroot: true,
 			apex_available: ["//apex_available:platform", "//apex_available:anyapex"],
+			min_sdk_version: "29",
 		}
 		rust_library {
 			name: "libtest",
@@ -105,6 +107,7 @@
                         native_coverage: false,
 			sysroot: true,
 			apex_available: ["//apex_available:platform", "//apex_available:anyapex"],
+			min_sdk_version: "29",
 		}
 		rust_library {
 			name: "libprotobuf",
diff --git a/scripts/build-aml-prebuilts.sh b/scripts/build-aml-prebuilts.sh
index 0c868ea..de22c45 100755
--- a/scripts/build-aml-prebuilts.sh
+++ b/scripts/build-aml-prebuilts.sh
@@ -94,7 +94,13 @@
 
     "Allow_missing_dependencies": ${SOONG_ALLOW_MISSING_DEPENDENCIES:-false},
     "Unbundled_build": ${TARGET_BUILD_UNBUNDLED:-false},
-    "UseGoma": ${USE_GOMA}
+    "UseGoma": ${USE_GOMA},
+
+    "VendorVars": {
+        "art_module": {
+            "source_build": "${ENABLE_ART_SOURCE_BUILD:-false}"
+        }
+    }
 }
 EOF
 
diff --git a/sdk/sdk.go b/sdk/sdk.go
index 50b0886..f3d0750 100644
--- a/sdk/sdk.go
+++ b/sdk/sdk.go
@@ -311,7 +311,7 @@
 		DistFiles:  android.MakeDefaultDistFiles(s.snapshotFile.Path()),
 		Include:    "$(BUILD_PHONY_PACKAGE)",
 		ExtraFooters: []android.AndroidMkExtraFootersFunc{
-			func(w io.Writer, name, prefix, moduleDir string, entries *android.AndroidMkEntries) {
+			func(w io.Writer, name, prefix, moduleDir string) {
 				// Allow the sdk to be built by simply passing its name on the command line.
 				fmt.Fprintln(w, ".PHONY:", s.Name())
 				fmt.Fprintln(w, s.Name()+":", s.snapshotFile.String())
diff --git a/shared/paths.go b/shared/paths.go
index 24ba057..f5dc5dd 100644
--- a/shared/paths.go
+++ b/shared/paths.go
@@ -20,21 +20,23 @@
 	"path/filepath"
 )
 
+// A SharedPaths represents a list of paths that are shared between
+// soong_ui and soong.
+type SharedPaths interface {
+	// BazelMetricsDir returns the path where a set of bazel profile
+	// files are stored for later processed by the metrics pipeline.
+	BazelMetricsDir() string
+}
+
 // Given the out directory, returns the root of the temp directory (to be cleared at the start of each execution of Soong)
 func TempDirForOutDir(outDir string) (tempPath string) {
 	return filepath.Join(outDir, ".temp")
 }
 
-// BazelMetricsDir returns the path where a set of bazel profile
-// files are stored for later processed by the metrics pipeline.
-func BazelMetricsDir(outDir string) string {
-	return filepath.Join(outDir, "bazel_metrics")
-}
-
 // BazelMetricsFilename returns the bazel profile filename based
 // on the action name. This is to help to store a set of bazel
 // profiles since bazel may execute multiple times during a single
 // build.
-func BazelMetricsFilename(outDir, actionName string) string {
-	return filepath.Join(BazelMetricsDir(outDir), actionName+"_bazel_profile.gz")
+func BazelMetricsFilename(s SharedPaths, actionName string) string {
+	return filepath.Join(s.BazelMetricsDir(), actionName+"_bazel_profile.gz")
 }
diff --git a/ui/build/bazel.go b/ui/build/bazel.go
index fac0461..4f2d645 100644
--- a/ui/build/bazel.go
+++ b/ui/build/bazel.go
@@ -15,6 +15,8 @@
 package build
 
 import (
+	"bytes"
+	"fmt"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -24,7 +26,7 @@
 	"android/soong/ui/metrics"
 )
 
-func getBazelInfo(ctx Context, config Config, bazelExecutable string, query string) string {
+func getBazelInfo(ctx Context, config Config, bazelExecutable string, bazelEnv map[string]string, query string) string {
 	infoCmd := Command(ctx, config, "bazel", bazelExecutable)
 
 	if extraStartupArgs, ok := infoCmd.Environment.Get("BAZEL_STARTUP_ARGS"); ok {
@@ -37,8 +39,9 @@
 		query,
 	)
 
-	infoCmd.Environment.Set("DIST_DIR", config.DistDir())
-	infoCmd.Environment.Set("SHELL", "/bin/bash")
+	for k, v := range bazelEnv {
+		infoCmd.Environment.Set(k, v)
+	}
 
 	infoCmd.Dir = filepath.Join(config.OutDir(), "..")
 
@@ -65,14 +68,21 @@
 
 	// Environment variables are the primary mechanism to pass information from
 	// soong_ui configuration or context to Bazel.
-	//
+	bazelEnv := make(map[string]string)
+
 	// Use *_NINJA variables to pass the root-relative path of the combined,
 	// kati-generated, soong-generated, and packaging Ninja files to Bazel.
 	// Bazel reads these from the lunch() repository rule.
-	config.environ.Set("COMBINED_NINJA", config.CombinedNinjaFile())
-	config.environ.Set("KATI_NINJA", config.KatiBuildNinjaFile())
-	config.environ.Set("PACKAGE_NINJA", config.KatiPackageNinjaFile())
-	config.environ.Set("SOONG_NINJA", config.SoongNinjaFile())
+	bazelEnv["COMBINED_NINJA"] = config.CombinedNinjaFile()
+	bazelEnv["KATI_NINJA"] = config.KatiBuildNinjaFile()
+	bazelEnv["PACKAGE_NINJA"] = config.KatiPackageNinjaFile()
+	bazelEnv["SOONG_NINJA"] = config.SoongNinjaFile()
+
+	// NOTE: When Bazel is used, config.DistDir() is rigged to return a fake distdir under config.OutDir()
+	// This is to ensure that Bazel can actually write there. See config.go for more details.
+	bazelEnv["DIST_DIR"] = config.DistDir()
+
+	bazelEnv["SHELL"] = "/bin/bash"
 
 	// `tools/bazel` is the default entry point for executing Bazel in the AOSP
 	// source tree.
@@ -94,7 +104,7 @@
 		// ninja_build target.
 		"--output_groups="+outputGroups,
 		// Generate a performance profile
-		"--profile="+filepath.Join(shared.BazelMetricsFilename(config.OutDir(), actionName)),
+		"--profile="+filepath.Join(shared.BazelMetricsFilename(config, actionName)),
 		"--slim_profile=true",
 	)
 
@@ -126,7 +136,7 @@
 
 		// We need to calculate --RBE_exec_root ourselves
 		ctx.Println("Getting Bazel execution_root...")
-		cmd.Args = append(cmd.Args, "--action_env=RBE_exec_root="+getBazelInfo(ctx, config, bazelExecutable, "execution_root"))
+		cmd.Args = append(cmd.Args, "--action_env=RBE_exec_root="+getBazelInfo(ctx, config, bazelExecutable, bazelEnv, "execution_root"))
 	}
 
 	// Ensure that the PATH environment variable value used in the action
@@ -149,15 +159,24 @@
 		"//:"+config.TargetProduct()+"-"+config.TargetBuildVariant(),
 	)
 
-	cmd.Environment.Set("DIST_DIR", config.DistDir())
-	cmd.Environment.Set("SHELL", "/bin/bash")
-
-	// Print the full command line for debugging purposes.
-	ctx.Println(cmd.Cmd)
-
 	// Execute the command at the root of the directory.
 	cmd.Dir = filepath.Join(config.OutDir(), "..")
-	ctx.Status.Status("Starting Bazel..")
+
+	for k, v := range bazelEnv {
+		cmd.Environment.Set(k, v)
+	}
+
+	// Make a human-readable version of the bazelEnv map
+	bazelEnvStringBuffer := new(bytes.Buffer)
+	for k, v := range bazelEnv {
+		fmt.Fprintf(bazelEnvStringBuffer, "%s=%s ", k, v)
+	}
+
+	// Print the implicit command line
+	ctx.Println("Bazel implicit command line: " + strings.Join(cmd.Environment.Environ(), " ") + " " + cmd.Cmd.String() + "\n")
+
+	// Print the explicit command line too
+	ctx.Println("Bazel explicit command line: " + bazelEnvStringBuffer.String() + cmd.Cmd.String() + "\n")
 
 	// Execute the build command.
 	cmd.RunAndStreamOrFatal()
@@ -168,44 +187,66 @@
 	// the files from the execution root's output direction into $OUT_DIR.
 
 	ctx.Println("Getting Bazel output_path...")
-	outputBasePath := getBazelInfo(ctx, config, bazelExecutable, "output_path")
+	outputBasePath := getBazelInfo(ctx, config, bazelExecutable, bazelEnv, "output_path")
 	// TODO: Don't hardcode out/ as the bazel output directory. This is
 	// currently hardcoded as ninja_build.output_root.
 	bazelNinjaBuildOutputRoot := filepath.Join(outputBasePath, "..", "out")
 
-	symlinkOutdir(ctx, config, bazelNinjaBuildOutputRoot, ".")
+	ctx.Println("Populating output directory...")
+	populateOutdir(ctx, config, bazelNinjaBuildOutputRoot, ".")
 }
 
 // For all files F recursively under rootPath/relativePath, creates symlinks
 // such that OutDir/F resolves to rootPath/F via symlinks.
-func symlinkOutdir(ctx Context, config Config, rootPath string, relativePath string) {
+// NOTE: For distdir paths we rename files instead of creating symlinks, so that the distdir is independent.
+func populateOutdir(ctx Context, config Config, rootPath string, relativePath string) {
 	destDir := filepath.Join(rootPath, relativePath)
 	os.MkdirAll(destDir, 0755)
 	files, err := ioutil.ReadDir(destDir)
 	if err != nil {
 		ctx.Fatal(err)
 	}
+
 	for _, f := range files {
+		// The original Bazel file path
 		destPath := filepath.Join(destDir, f.Name())
+
+		// The desired Soong file path
 		srcPath := filepath.Join(config.OutDir(), relativePath, f.Name())
-		if statResult, err := os.Stat(srcPath); err == nil {
-			if statResult.Mode().IsDir() && f.IsDir() {
-				// Directory under OutDir already exists, so recurse on its contents.
-				symlinkOutdir(ctx, config, rootPath, filepath.Join(relativePath, f.Name()))
-			} else if !statResult.Mode().IsDir() && !f.IsDir() {
-				// File exists both in source and destination, and it's not a directory
-				// in either location. Do nothing.
-				// This can arise for files which are generated under OutDir outside of
-				// soong_build, such as .bootstrap files.
+
+		destLstatResult, destLstatErr := os.Lstat(destPath)
+		if destLstatErr != nil {
+			ctx.Fatalf("Unable to Lstat dest %s: %s", destPath, destLstatErr)
+		}
+
+		srcLstatResult, srcLstatErr := os.Lstat(srcPath)
+
+		if srcLstatErr == nil {
+			if srcLstatResult.IsDir() && destLstatResult.IsDir() {
+				// src and dest are both existing dirs - recurse on the dest dir contents...
+				populateOutdir(ctx, config, rootPath, filepath.Join(relativePath, f.Name()))
 			} else {
-				// File is a directory in one location but not the other. Raise an error.
-				ctx.Fatalf("Could not link %s to %s due to conflict", srcPath, destPath)
+				// Ignore other pre-existing src files (could be pre-existing files, directories, symlinks, ...)
+				// This can arise for files which are generated under OutDir outside of soong_build, such as .bootstrap files.
+				// FIXME: This might cause a problem later e.g. if a symlink in the build graph changes...
 			}
-		} else if os.IsNotExist(err) {
-			// Create symlink srcPath -> fullDestPath.
-			os.Symlink(destPath, srcPath)
 		} else {
-			ctx.Fatalf("Unable to stat %s: %s", srcPath, err)
+			if !os.IsNotExist(srcLstatErr) {
+				ctx.Fatalf("Unable to Lstat src %s: %s", srcPath, srcLstatErr)
+			}
+
+			if strings.Contains(destDir, config.DistDir()) {
+				// We need to make a "real" file/dir instead of making a symlink (because the distdir can't have symlinks)
+				// Rename instead of copy in order to save disk space.
+				if err := os.Rename(destPath, srcPath); err != nil {
+					ctx.Fatalf("Unable to rename %s -> %s due to error %s", srcPath, destPath, err)
+				}
+			} else {
+				// src does not exist, so try to create a src -> dest symlink (i.e. a Soong path -> Bazel path symlink)
+				if err := os.Symlink(destPath, srcPath); err != nil {
+					ctx.Fatalf("Unable to create symlink %s -> %s due to error %s", srcPath, destPath, err)
+				}
+			}
 		}
 	}
 }
diff --git a/ui/build/build.go b/ui/build/build.go
index e8f0fc4..926da31 100644
--- a/ui/build/build.go
+++ b/ui/build/build.go
@@ -302,7 +302,7 @@
 	}
 
 	subDir := filepath.Join(subDirs...)
-	destDir := filepath.Join(config.DistDir(), "soong_ui", subDir)
+	destDir := filepath.Join(config.RealDistDir(), "soong_ui", subDir)
 
 	if err := os.MkdirAll(destDir, 0777); err != nil { // a+rwx
 		ctx.Printf("failed to mkdir %s: %s", destDir, err.Error())
@@ -321,7 +321,7 @@
 	}
 
 	subDir := filepath.Join(subDirs...)
-	destDir := filepath.Join(config.DistDir(), "soong_ui", subDir)
+	destDir := filepath.Join(config.RealDistDir(), "soong_ui", subDir)
 
 	if err := os.MkdirAll(destDir, 0777); err != nil { // a+rwx
 		ctx.Printf("failed to mkdir %s: %s", destDir, err.Error())
diff --git a/ui/build/config.go b/ui/build/config.go
index c9911f3..ecca4de 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -65,6 +65,12 @@
 	brokenNinjaEnvVars []string
 
 	pathReplaced bool
+
+	useBazel bool
+
+	// During Bazel execution, Bazel cannot write outside OUT_DIR.
+	// So if DIST_DIR is set to an external dir (outside of OUT_DIR), we need to rig it temporarily and then migrate files at the end of the build.
+	riggedDistDirForBazel string
 }
 
 const srcDirFileCheck = "build/soong/root.bp"
@@ -221,7 +227,7 @@
 		ctx.Fatalln("Directory names containing spaces are not supported")
 	}
 
-	if distDir := ret.DistDir(); strings.ContainsRune(distDir, ' ') {
+	if distDir := ret.RealDistDir(); strings.ContainsRune(distDir, ' ') {
 		ctx.Println("The absolute path of your dist directory ($DIST_DIR) contains a space character:")
 		ctx.Println()
 		ctx.Printf("%q\n", distDir)
@@ -275,16 +281,26 @@
 		}
 	}
 
-	bpd := shared.BazelMetricsDir(ret.OutDir())
+	bpd := ret.BazelMetricsDir()
 	if err := os.RemoveAll(bpd); err != nil {
 		ctx.Fatalf("Unable to remove bazel profile directory %q: %v", bpd, err)
 	}
+
+	ret.useBazel = ret.environ.IsEnvTrue("USE_BAZEL")
+
 	if ret.UseBazel() {
 		if err := os.MkdirAll(bpd, 0777); err != nil {
 			ctx.Fatalf("Failed to create bazel profile directory %q: %v", bpd, err)
 		}
 	}
 
+	if ret.UseBazel() {
+		ret.riggedDistDirForBazel = filepath.Join(ret.OutDir(), "dist")
+	} else {
+		// Not rigged
+		ret.riggedDistDirForBazel = ret.distDir
+	}
+
 	c := Config{ret}
 	storeConfigMetrics(ctx, c)
 	return c
@@ -697,6 +713,14 @@
 }
 
 func (c *configImpl) DistDir() string {
+	if c.UseBazel() {
+		return c.riggedDistDirForBazel
+	} else {
+		return c.distDir
+	}
+}
+
+func (c *configImpl) RealDistDir() string {
 	return c.distDir
 }
 
@@ -863,13 +887,7 @@
 }
 
 func (c *configImpl) UseBazel() bool {
-	if v, ok := c.environ.Get("USE_BAZEL"); ok {
-		v = strings.TrimSpace(v)
-		if v != "" && v != "false" {
-			return true
-		}
-	}
-	return false
+	return c.useBazel
 }
 
 func (c *configImpl) StartRBE() bool {
@@ -886,14 +904,14 @@
 	return true
 }
 
-func (c *configImpl) logDir() string {
+func (c *configImpl) rbeLogDir() string {
 	for _, f := range []string{"RBE_log_dir", "FLAG_log_dir"} {
 		if v, ok := c.environ.Get(f); ok {
 			return v
 		}
 	}
 	if c.Dist() {
-		return filepath.Join(c.DistDir(), "logs")
+		return c.LogsDir()
 	}
 	return c.OutDir()
 }
@@ -904,7 +922,7 @@
 			return v
 		}
 	}
-	return c.logDir()
+	return c.rbeLogDir()
 }
 
 func (c *configImpl) rbeLogPath() string {
@@ -913,7 +931,7 @@
 			return v
 		}
 	}
-	return fmt.Sprintf("text://%v/reproxy_log.txt", c.logDir())
+	return fmt.Sprintf("text://%v/reproxy_log.txt", c.rbeLogDir())
 }
 
 func (c *configImpl) rbeExecRoot() string {
@@ -1121,3 +1139,21 @@
 	}
 	return ""
 }
+
+// LogsDir returns the logs directory where build log and metrics
+// files are located. By default, the logs directory is the out
+// directory. If the argument dist is specified, the logs directory
+// is <dist_dir>/logs.
+func (c *configImpl) LogsDir() string {
+	if c.Dist() {
+		// Always write logs to the real dist dir, even if Bazel is using a rigged dist dir for other files
+		return filepath.Join(c.RealDistDir(), "logs")
+	}
+	return c.OutDir()
+}
+
+// BazelMetricsDir returns the <logs dir>/bazel_metrics directory
+// where the bazel profiles are located.
+func (c *configImpl) BazelMetricsDir() string {
+	return filepath.Join(c.LogsDir(), "bazel_metrics")
+}
diff --git a/ui/build/ninja.go b/ui/build/ninja.go
index ffd1ab9..7799766 100644
--- a/ui/build/ninja.go
+++ b/ui/build/ninja.go
@@ -139,15 +139,6 @@
 			// b/147197813 - used by art-check-debug-apex-gen
 			"EMMA_INSTRUMENT_FRAMEWORK",
 
-			// Goma -- gomacc may not need all of these
-			"GOMA_DIR",
-			"GOMA_DISABLED",
-			"GOMA_FAIL_FAST",
-			"GOMA_FALLBACK",
-			"GOMA_GCE_SERVICE_ACCOUNT",
-			"GOMA_TMP_DIR",
-			"GOMA_USE_LOCAL",
-
 			// RBE client
 			"RBE_compare",
 			"RBE_exec_root",
diff --git a/ui/build/rbe.go b/ui/build/rbe.go
index 64f3d4c..d9c33f6 100644
--- a/ui/build/rbe.go
+++ b/ui/build/rbe.go
@@ -74,7 +74,7 @@
 func getRBEVars(ctx Context, config Config) map[string]string {
 	vars := map[string]string{
 		"RBE_log_path":   config.rbeLogPath(),
-		"RBE_log_dir":    config.logDir(),
+		"RBE_log_dir":    config.rbeLogDir(),
 		"RBE_re_proxy":   config.rbeReproxy(),
 		"RBE_exec_root":  config.rbeExecRoot(),
 		"RBE_output_dir": config.rbeStatsOutputDir(),
diff --git a/ui/build/test_build.go b/ui/build/test_build.go
index 3164680..41acc26 100644
--- a/ui/build/test_build.go
+++ b/ui/build/test_build.go
@@ -68,6 +68,7 @@
 	miniBootstrapDir := filepath.Join(outDir, "soong", ".minibootstrap")
 	modulePathsDir := filepath.Join(outDir, ".module_paths")
 	variablesFilePath := filepath.Join(outDir, "soong", "soong.variables")
+
 	// dexpreopt.config is an input to the soong_docs action, which runs the
 	// soong_build primary builder. However, this file is created from $(shell)
 	// invocation at Kati parse time, so it's not an explicit output of any
@@ -75,6 +76,9 @@
 	// treated as an source file.
 	dexpreoptConfigFilePath := filepath.Join(outDir, "soong", "dexpreopt.config")
 
+	// out/build_date.txt is considered a "source file"
+	buildDatetimeFilePath := filepath.Join(outDir, "build_date.txt")
+
 	danglingRules := make(map[string]bool)
 
 	scanner := bufio.NewScanner(stdout)
@@ -88,7 +92,8 @@
 			strings.HasPrefix(line, miniBootstrapDir) ||
 			strings.HasPrefix(line, modulePathsDir) ||
 			line == variablesFilePath ||
-			line == dexpreoptConfigFilePath {
+			line == dexpreoptConfigFilePath ||
+			line == buildDatetimeFilePath {
 			// Leaf node is in one of Soong's bootstrap directories, which do not have
 			// full build rules in the primary build.ninja file.
 			continue
diff --git a/ui/build/upload.go b/ui/build/upload.go
index 4f30136..55ca800 100644
--- a/ui/build/upload.go
+++ b/ui/build/upload.go
@@ -40,13 +40,42 @@
 	tmpDir = ioutil.TempDir
 )
 
+// pruneMetricsFiles iterates the list of paths, checking if a path exist.
+// If a path is a file, it is added to the return list. If the path is a
+// directory, a recursive call is made to add the children files of the
+// path.
+func pruneMetricsFiles(paths []string) []string {
+	var metricsFiles []string
+	for _, p := range paths {
+		fi, err := os.Stat(p)
+		// Some paths passed may not exist. For example, build errors protobuf
+		// file may not exist since the build was successful.
+		if err != nil {
+			continue
+		}
+
+		if fi.IsDir() {
+			if l, err := ioutil.ReadDir(p); err == nil {
+				files := make([]string, 0, len(l))
+				for _, fi := range l {
+					files = append(files, filepath.Join(p, fi.Name()))
+				}
+				metricsFiles = append(metricsFiles, pruneMetricsFiles(files)...)
+			}
+		} else {
+			metricsFiles = append(metricsFiles, p)
+		}
+	}
+	return metricsFiles
+}
+
 // UploadMetrics uploads a set of metrics files to a server for analysis. An
 // uploader full path is specified in ANDROID_ENABLE_METRICS_UPLOAD environment
 // variable in order to upload the set of metrics files. The metrics files are
 // first copied to a temporary directory and the uploader is then executed in
 // the background to allow the user/system to continue working. Soong communicates
 // to the uploader through the upload_proto raw protobuf file.
-func UploadMetrics(ctx Context, config Config, simpleOutput bool, buildStarted time.Time, files ...string) {
+func UploadMetrics(ctx Context, config Config, simpleOutput bool, buildStarted time.Time, paths ...string) {
 	ctx.BeginTrace(metrics.RunSetupTool, "upload_metrics")
 	defer ctx.EndTrace()
 
@@ -56,15 +85,8 @@
 		return
 	}
 
-	// Some files passed in to this function may not exist. For example,
-	// build errors protobuf file may not exist since the build was successful.
-	var metricsFiles []string
-	for _, f := range files {
-		if _, err := os.Stat(f); err == nil {
-			metricsFiles = append(metricsFiles, f)
-		}
-	}
-
+	// Several of the files might be directories.
+	metricsFiles := pruneMetricsFiles(paths)
 	if len(metricsFiles) == 0 {
 		return
 	}
diff --git a/ui/build/upload_test.go b/ui/build/upload_test.go
index 768b031..b740c11 100644
--- a/ui/build/upload_test.go
+++ b/ui/build/upload_test.go
@@ -19,6 +19,8 @@
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"reflect"
+	"sort"
 	"strconv"
 	"strings"
 	"testing"
@@ -27,6 +29,49 @@
 	"android/soong/ui/logger"
 )
 
+func TestPruneMetricsFiles(t *testing.T) {
+	rootDir := t.TempDir()
+
+	dirs := []string{
+		filepath.Join(rootDir, "d1"),
+		filepath.Join(rootDir, "d1", "d2"),
+		filepath.Join(rootDir, "d1", "d2", "d3"),
+	}
+
+	files := []string{
+		filepath.Join(rootDir, "d1", "f1"),
+		filepath.Join(rootDir, "d1", "d2", "f1"),
+		filepath.Join(rootDir, "d1", "d2", "d3", "f1"),
+	}
+
+	for _, d := range dirs {
+		if err := os.MkdirAll(d, 0777); err != nil {
+			t.Fatalf("got %v, expecting nil error for making directory %q", err, d)
+		}
+	}
+
+	for _, f := range files {
+		if err := ioutil.WriteFile(f, []byte{}, 0777); err != nil {
+			t.Fatalf("got %v, expecting nil error on writing file %q", err, f)
+		}
+	}
+
+	want := []string{
+		filepath.Join(rootDir, "d1", "f1"),
+		filepath.Join(rootDir, "d1", "d2", "f1"),
+		filepath.Join(rootDir, "d1", "d2", "d3", "f1"),
+	}
+
+	got := pruneMetricsFiles([]string{rootDir})
+
+	sort.Strings(got)
+	sort.Strings(want)
+
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("got %q, want %q after pruning metrics files", got, want)
+	}
+}
+
 func TestUploadMetrics(t *testing.T) {
 	ctx := testContext()
 	tests := []struct {