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// Copyright 2016 Google Inc. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package android
import (
"fmt"
"reflect"
"github.com/google/blueprint"
"github.com/google/blueprint/proptools"
)
// This file implements common functionality for handling modules that may exist as prebuilts,
// source, or both.
func RegisterPrebuiltMutators(ctx RegistrationContext) {
ctx.PreArchMutators(RegisterPrebuiltsPreArchMutators)
ctx.PostDepsMutators(RegisterPrebuiltsPostDepsMutators)
}
// Marks a dependency tag as possibly preventing a reference to a source from being
// replaced with the prebuilt.
type ReplaceSourceWithPrebuilt interface {
blueprint.DependencyTag
// Return true if the dependency defined by this tag should be replaced with the
// prebuilt.
ReplaceSourceWithPrebuilt() bool
}
type prebuiltDependencyTag struct {
blueprint.BaseDependencyTag
}
var PrebuiltDepTag prebuiltDependencyTag
// Mark this tag so dependencies that use it are excluded from visibility enforcement.
func (t prebuiltDependencyTag) ExcludeFromVisibilityEnforcement() {}
// Mark this tag so dependencies that use it are excluded from APEX contents.
func (t prebuiltDependencyTag) ExcludeFromApexContents() {}
var _ ExcludeFromVisibilityEnforcementTag = PrebuiltDepTag
var _ ExcludeFromApexContentsTag = PrebuiltDepTag
type PrebuiltProperties struct {
// When prefer is set to true the prebuilt will be used instead of any source module with
// a matching name.
Prefer *bool `android:"arch_variant"`
SourceExists bool `blueprint:"mutated"`
UsePrebuilt bool `blueprint:"mutated"`
// Set if the module has been renamed to remove the "prebuilt_" prefix.
PrebuiltRenamedToSource bool `blueprint:"mutated"`
}
type Prebuilt struct {
properties PrebuiltProperties
srcsSupplier PrebuiltSrcsSupplier
srcsPropertyName string
}
func (p *Prebuilt) Name(name string) string {
return "prebuilt_" + name
}
func (p *Prebuilt) ForcePrefer() {
p.properties.Prefer = proptools.BoolPtr(true)
}
func (p *Prebuilt) Prefer() bool {
return proptools.Bool(p.properties.Prefer)
}
// The below source-related functions and the srcs, src fields are based on an assumption that
// prebuilt modules have a static source property at the moment. Currently there is only one
// exception, android_app_import, which chooses a source file depending on the product's DPI
// preference configs. We'll want to add native support for dynamic source cases if we end up having
// more modules like this.
func (p *Prebuilt) SingleSourcePath(ctx ModuleContext) Path {
if p.srcsSupplier != nil {
srcs := p.srcsSupplier()
if len(srcs) == 0 {
ctx.PropertyErrorf(p.srcsPropertyName, "missing prebuilt source file")
return nil
}
if len(srcs) > 1 {
ctx.PropertyErrorf(p.srcsPropertyName, "multiple prebuilt source files")
return nil
}
// Return the singleton source after expanding any filegroup in the
// sources.
src := srcs[0]
return PathForModuleSrc(ctx, src)
} else {
ctx.ModuleErrorf("prebuilt source was not set")
return nil
}
}
func (p *Prebuilt) UsePrebuilt() bool {
return p.properties.UsePrebuilt
}
// Called to provide the srcs value for the prebuilt module.
//
// Return the src value or nil if it is not available.
type PrebuiltSrcsSupplier func() []string
// Initialize the module as a prebuilt module that uses the provided supplier to access the
// prebuilt sources of the module.
//
// The supplier will be called multiple times and must return the same values each time it
// is called. If it returns an empty array (or nil) then the prebuilt module will not be used
// as a replacement for a source module with the same name even if prefer = true.
//
// If the Prebuilt.SingleSourcePath() is called on the module then this must return an array
// containing exactly one source file.
//
// The provided property name is used to provide helpful error messages in the event that
// a problem arises, e.g. calling SingleSourcePath() when more than one source is provided.
func InitPrebuiltModuleWithSrcSupplier(module PrebuiltInterface, srcsSupplier PrebuiltSrcsSupplier, srcsPropertyName string) {
p := module.Prebuilt()
module.AddProperties(&p.properties)
if srcsSupplier == nil {
panic(fmt.Errorf("srcsSupplier must not be nil"))
}
if srcsPropertyName == "" {
panic(fmt.Errorf("srcsPropertyName must not be empty"))
}
p.srcsSupplier = srcsSupplier
p.srcsPropertyName = srcsPropertyName
}
func InitPrebuiltModule(module PrebuiltInterface, srcs *[]string) {
if srcs == nil {
panic(fmt.Errorf("srcs must not be nil"))
}
srcsSupplier := func() []string {
return *srcs
}
InitPrebuiltModuleWithSrcSupplier(module, srcsSupplier, "srcs")
}
func InitSingleSourcePrebuiltModule(module PrebuiltInterface, srcProps interface{}, srcField string) {
srcPropsValue := reflect.ValueOf(srcProps).Elem()
srcStructField, _ := srcPropsValue.Type().FieldByName(srcField)
if !srcPropsValue.IsValid() || srcStructField.Name == "" {
panic(fmt.Errorf("invalid single source prebuilt %+v", module))
}
if srcPropsValue.Kind() != reflect.Struct && srcPropsValue.Kind() != reflect.Interface {
panic(fmt.Errorf("invalid single source prebuilt %+v", srcProps))
}
srcFieldIndex := srcStructField.Index
srcPropertyName := proptools.PropertyNameForField(srcField)
srcsSupplier := func() []string {
value := srcPropsValue.FieldByIndex(srcFieldIndex)
if value.Kind() == reflect.Ptr {
value = value.Elem()
}
if value.Kind() != reflect.String {
panic(fmt.Errorf("prebuilt src field %q should be a string or a pointer to one but was %d %q", srcPropertyName, value.Kind(), value))
}
src := value.String()
if src == "" {
return nil
}
return []string{src}
}
InitPrebuiltModuleWithSrcSupplier(module, srcsSupplier, srcPropertyName)
}
type PrebuiltInterface interface {
Module
Prebuilt() *Prebuilt
}
func RegisterPrebuiltsPreArchMutators(ctx RegisterMutatorsContext) {
ctx.BottomUp("prebuilt_rename", PrebuiltRenameMutator).Parallel()
}
func RegisterPrebuiltsPostDepsMutators(ctx RegisterMutatorsContext) {
ctx.BottomUp("prebuilt_source", PrebuiltSourceDepsMutator).Parallel()
ctx.TopDown("prebuilt_select", PrebuiltSelectModuleMutator).Parallel()
ctx.BottomUp("prebuilt_postdeps", PrebuiltPostDepsMutator).Parallel()
}
// PrebuiltRenameMutator ensures that there always is a module with an
// undecorated name.
func PrebuiltRenameMutator(ctx BottomUpMutatorContext) {
if m, ok := ctx.Module().(PrebuiltInterface); ok && m.Prebuilt() != nil {
name := m.base().BaseModuleName()
if !ctx.OtherModuleExists(name) {
ctx.Rename(name)
m.Prebuilt().properties.PrebuiltRenamedToSource = true
}
}
}
// PrebuiltSourceDepsMutator adds dependencies to the prebuilt module from the
// corresponding source module, if one exists for the same variant.
func PrebuiltSourceDepsMutator(ctx BottomUpMutatorContext) {
if m, ok := ctx.Module().(PrebuiltInterface); ok && m.Enabled() && m.Prebuilt() != nil {
p := m.Prebuilt()
if !p.properties.PrebuiltRenamedToSource {
name := m.base().BaseModuleName()
if ctx.OtherModuleReverseDependencyVariantExists(name) {
ctx.AddReverseDependency(ctx.Module(), PrebuiltDepTag, name)
p.properties.SourceExists = true
}
}
}
}
// PrebuiltSelectModuleMutator marks prebuilts that are used, either overriding source modules or
// because the source module doesn't exist. It also disables installing overridden source modules.
func PrebuiltSelectModuleMutator(ctx TopDownMutatorContext) {
if m, ok := ctx.Module().(PrebuiltInterface); ok && m.Prebuilt() != nil {
p := m.Prebuilt()
if p.srcsSupplier == nil {
panic(fmt.Errorf("prebuilt module did not have InitPrebuiltModule called on it"))
}
if !p.properties.SourceExists {
p.properties.UsePrebuilt = p.usePrebuilt(ctx, nil)
}
} else if s, ok := ctx.Module().(Module); ok {
ctx.VisitDirectDepsWithTag(PrebuiltDepTag, func(m Module) {
p := m.(PrebuiltInterface).Prebuilt()
if p.usePrebuilt(ctx, s) {
p.properties.UsePrebuilt = true
s.SkipInstall()
}
})
}
}
// PrebuiltPostDepsMutator does two operations. It replace dependencies on the
// source module with dependencies on the prebuilt when both modules exist and
// the prebuilt should be used. When the prebuilt should not be used, disable
// installing it. Secondly, it also adds a sourcegroup to any filegroups found
// in the prebuilt's 'Srcs' property.
func PrebuiltPostDepsMutator(ctx BottomUpMutatorContext) {
if m, ok := ctx.Module().(PrebuiltInterface); ok && m.Prebuilt() != nil {
p := m.Prebuilt()
name := m.base().BaseModuleName()
if p.properties.UsePrebuilt {
if p.properties.SourceExists {
ctx.ReplaceDependenciesIf(name, func(from blueprint.Module, tag blueprint.DependencyTag, to blueprint.Module) bool {
if t, ok := tag.(ReplaceSourceWithPrebuilt); ok {
return t.ReplaceSourceWithPrebuilt()
}
return true
})
}
} else {
m.SkipInstall()
}
}
}
// usePrebuilt returns true if a prebuilt should be used instead of the source module. The prebuilt
// will be used if it is marked "prefer" or if the source module is disabled.
func (p *Prebuilt) usePrebuilt(ctx TopDownMutatorContext, source Module) bool {
if p.srcsSupplier != nil && len(p.srcsSupplier()) == 0 {
return false
}
// TODO: use p.Properties.Name and ctx.ModuleDir to override preference
if Bool(p.properties.Prefer) {
return true
}
return source == nil || !source.Enabled()
}
func (p *Prebuilt) SourceExists() bool {
return p.properties.SourceExists
}