platform_build_soong/android/prebuilt.go

155 lines
4.5 KiB
Go

// 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"
"github.com/google/blueprint"
)
// This file implements common functionality for handling modules that may exist as prebuilts,
// source, or both.
type prebuiltDependencyTag struct {
blueprint.BaseDependencyTag
}
var prebuiltDepTag prebuiltDependencyTag
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"`
}
type Prebuilt struct {
properties PrebuiltProperties
module Module
srcs *[]string
}
func (p *Prebuilt) Name(name string) string {
return "prebuilt_" + name
}
func (p *Prebuilt) SingleSourcePath(ctx ModuleContext) Path {
if len(*p.srcs) == 0 {
ctx.PropertyErrorf("srcs", "missing prebuilt source file")
return nil
}
if len(*p.srcs) > 1 {
ctx.PropertyErrorf("srcs", "multiple prebuilt source files")
return nil
}
return PathForModuleSrc(ctx, (*p.srcs)[0])
}
func InitPrebuiltModule(module PrebuiltInterface, srcs *[]string) {
p := module.Prebuilt()
module.AddProperties(&p.properties)
p.srcs = srcs
}
type PrebuiltInterface interface {
Module
Prebuilt() *Prebuilt
}
func RegisterPrebuiltsPreArchMutators(ctx RegisterMutatorsContext) {
ctx.BottomUp("prebuilts", prebuiltMutator).Parallel()
}
func RegisterPrebuiltsPostDepsMutators(ctx RegisterMutatorsContext) {
ctx.TopDown("prebuilt_select", PrebuiltSelectModuleMutator).Parallel()
ctx.BottomUp("prebuilt_replace", PrebuiltReplaceMutator).Parallel()
}
// prebuiltMutator ensures that there is always a module with an undecorated name, and marks
// prebuilt modules that have both a prebuilt and a source module.
func prebuiltMutator(ctx BottomUpMutatorContext) {
if m, ok := ctx.Module().(PrebuiltInterface); ok && m.Prebuilt() != nil {
p := m.Prebuilt()
name := m.base().BaseModuleName()
if ctx.OtherModuleExists(name) {
ctx.AddReverseDependency(ctx.Module(), prebuiltDepTag, name)
p.properties.SourceExists = true
} else {
ctx.Rename(name)
}
}
}
// 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.srcs == 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.VisitDirectDeps(func(m blueprint.Module) {
if ctx.OtherModuleDependencyTag(m) == prebuiltDepTag {
p := m.(PrebuiltInterface).Prebuilt()
if p.usePrebuilt(ctx, s) {
p.properties.UsePrebuilt = true
s.SkipInstall()
}
}
})
}
}
// PrebuiltReplaceMutator replaces 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.
func PrebuiltReplaceMutator(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.ReplaceDependencies(name)
}
} 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 len(*p.srcs) == 0 {
return false
}
// TODO: use p.Properties.Name and ctx.ModuleDir to override preference
if p.properties.Prefer {
return true
}
return source == nil || !source.Enabled()
}