| // Copyright (C) 2019 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 android |
| |
| // This file contains all the foundation components for override modules and their base module |
| // types. Override modules are a kind of opposite of default modules in that they override certain |
| // properties of an existing base module whereas default modules provide base module data to be |
| // overridden. However, unlike default and defaultable module pairs, both override and overridable |
| // modules generate and output build actions, and it is up to product make vars to decide which one |
| // to actually build and install in the end. In other words, default modules and defaultable modules |
| // can be compared to abstract classes and concrete classes in C++ and Java. By the same analogy, |
| // both override and overridable modules act like concrete classes. |
| // |
| // There is one more crucial difference from the logic perspective. Unlike default pairs, most Soong |
| // actions happen in the base (overridable) module by creating a local variant for each override |
| // module based on it. |
| |
| import ( |
| "sort" |
| "sync" |
| |
| "github.com/google/blueprint" |
| "github.com/google/blueprint/proptools" |
| ) |
| |
| // Interface for override module types, e.g. override_android_app, override_apex |
| type OverrideModule interface { |
| Module |
| |
| getOverridingProperties() []interface{} |
| setOverridingProperties(properties []interface{}) |
| |
| getOverrideModuleProperties() *OverrideModuleProperties |
| |
| // Internal funcs to handle interoperability between override modules and prebuilts. |
| // i.e. cases where an overriding module, too, is overridden by a prebuilt module. |
| setOverriddenByPrebuilt(overridden bool) |
| getOverriddenByPrebuilt() bool |
| } |
| |
| // Base module struct for override module types |
| type OverrideModuleBase struct { |
| moduleProperties OverrideModuleProperties |
| |
| overridingProperties []interface{} |
| |
| overriddenByPrebuilt bool |
| } |
| |
| type OverrideModuleProperties struct { |
| // Name of the base module to be overridden |
| Base *string |
| |
| // TODO(jungjw): Add an optional override_name bool flag. |
| } |
| |
| func (o *OverrideModuleBase) getOverridingProperties() []interface{} { |
| return o.overridingProperties |
| } |
| |
| func (o *OverrideModuleBase) setOverridingProperties(properties []interface{}) { |
| o.overridingProperties = properties |
| } |
| |
| func (o *OverrideModuleBase) getOverrideModuleProperties() *OverrideModuleProperties { |
| return &o.moduleProperties |
| } |
| |
| func (o *OverrideModuleBase) GetOverriddenModuleName() string { |
| return proptools.String(o.moduleProperties.Base) |
| } |
| |
| func (o *OverrideModuleBase) setOverriddenByPrebuilt(overridden bool) { |
| o.overriddenByPrebuilt = overridden |
| } |
| |
| func (o *OverrideModuleBase) getOverriddenByPrebuilt() bool { |
| return o.overriddenByPrebuilt |
| } |
| |
| func InitOverrideModule(m OverrideModule) { |
| m.setOverridingProperties(m.GetProperties()) |
| |
| m.AddProperties(m.getOverrideModuleProperties()) |
| } |
| |
| // Interface for overridable module types, e.g. android_app, apex |
| type OverridableModule interface { |
| Module |
| moduleBase() *OverridableModuleBase |
| |
| setOverridableProperties(prop []interface{}) |
| |
| addOverride(o OverrideModule) |
| getOverrides() []OverrideModule |
| |
| override(ctx BaseModuleContext, o OverrideModule) |
| GetOverriddenBy() string |
| |
| setOverridesProperty(overridesProperties *[]string) |
| |
| // Due to complications with incoming dependencies, overrides are processed after DepsMutator. |
| // So, overridable properties need to be handled in a separate, dedicated deps mutator. |
| OverridablePropertiesDepsMutator(ctx BottomUpMutatorContext) |
| } |
| |
| type overridableModuleProperties struct { |
| OverriddenBy string `blueprint:"mutated"` |
| } |
| |
| // Base module struct for overridable module types |
| type OverridableModuleBase struct { |
| // List of OverrideModules that override this base module |
| overrides []OverrideModule |
| // Used to parallelize registerOverrideMutator executions. Note that only addOverride locks this |
| // mutex. It is because addOverride and getOverride are used in different mutators, and so are |
| // guaranteed to be not mixed. (And, getOverride only reads from overrides, and so don't require |
| // mutex locking.) |
| overridesLock sync.Mutex |
| |
| overridableProperties []interface{} |
| |
| // If an overridable module has a property to list other modules that itself overrides, it should |
| // set this to a pointer to the property through the InitOverridableModule function, so that |
| // override information is propagated and aggregated correctly. |
| overridesProperty *[]string |
| |
| overridableModuleProperties overridableModuleProperties |
| } |
| |
| func InitOverridableModule(m OverridableModule, overridesProperty *[]string) { |
| m.setOverridableProperties(m.(Module).GetProperties()) |
| m.setOverridesProperty(overridesProperty) |
| m.AddProperties(&m.moduleBase().overridableModuleProperties) |
| } |
| |
| func (o *OverridableModuleBase) moduleBase() *OverridableModuleBase { |
| return o |
| } |
| |
| func (b *OverridableModuleBase) setOverridableProperties(prop []interface{}) { |
| b.overridableProperties = prop |
| } |
| |
| func (b *OverridableModuleBase) addOverride(o OverrideModule) { |
| b.overridesLock.Lock() |
| b.overrides = append(b.overrides, o) |
| b.overridesLock.Unlock() |
| } |
| |
| // Should NOT be used in the same mutator as addOverride. |
| func (b *OverridableModuleBase) getOverrides() []OverrideModule { |
| b.overridesLock.Lock() |
| sort.Slice(b.overrides, func(i, j int) bool { |
| return b.overrides[i].Name() < b.overrides[j].Name() |
| }) |
| b.overridesLock.Unlock() |
| return b.overrides |
| } |
| |
| func (b *OverridableModuleBase) setOverridesProperty(overridesProperty *[]string) { |
| b.overridesProperty = overridesProperty |
| } |
| |
| // Overrides a base module with the given OverrideModule. |
| func (b *OverridableModuleBase) override(ctx BaseModuleContext, o OverrideModule) { |
| for _, p := range b.overridableProperties { |
| for _, op := range o.getOverridingProperties() { |
| if proptools.TypeEqual(p, op) { |
| err := proptools.ExtendProperties(p, op, nil, proptools.OrderReplace) |
| if err != nil { |
| if propertyErr, ok := err.(*proptools.ExtendPropertyError); ok { |
| ctx.PropertyErrorf(propertyErr.Property, "%s", propertyErr.Err.Error()) |
| } else { |
| panic(err) |
| } |
| } |
| } |
| } |
| } |
| // Adds the base module to the overrides property, if exists, of the overriding module. See the |
| // comment on OverridableModuleBase.overridesProperty for details. |
| if b.overridesProperty != nil { |
| *b.overridesProperty = append(*b.overridesProperty, ctx.ModuleName()) |
| } |
| b.overridableModuleProperties.OverriddenBy = o.Name() |
| } |
| |
| // GetOverriddenBy returns the name of the override module that has overridden this module. |
| // For example, if an override module foo has its 'base' property set to bar, then another local variant |
| // of bar is created and its properties are overriden by foo. This method returns bar when called from |
| // the new local variant. It returns "" when called from the original variant of bar. |
| func (b *OverridableModuleBase) GetOverriddenBy() string { |
| return b.overridableModuleProperties.OverriddenBy |
| } |
| |
| func (b *OverridableModuleBase) OverridablePropertiesDepsMutator(ctx BottomUpMutatorContext) { |
| } |
| |
| // Mutators for override/overridable modules. All the fun happens in these functions. It is critical |
| // to keep them in this order and not put any order mutators between them. |
| func RegisterOverridePostDepsMutators(ctx RegisterMutatorsContext) { |
| ctx.BottomUp("override_deps", overrideModuleDepsMutator).Parallel() |
| ctx.BottomUp("perform_override", performOverrideMutator).Parallel() |
| // overridableModuleDepsMutator calls OverridablePropertiesDepsMutator so that overridable modules can |
| // add deps from overridable properties. |
| ctx.BottomUp("overridable_deps", overridableModuleDepsMutator).Parallel() |
| // Because overridableModuleDepsMutator is run after PrebuiltPostDepsMutator, |
| // prebuilt's ReplaceDependencies doesn't affect to those deps added by overridable properties. |
| // By running PrebuiltPostDepsMutator again after overridableModuleDepsMutator, deps via overridable properties |
| // can be replaced with prebuilts. |
| ctx.BottomUp("replace_deps_on_prebuilts_for_overridable_deps_again", PrebuiltPostDepsMutator).Parallel() |
| ctx.BottomUp("replace_deps_on_override", replaceDepsOnOverridingModuleMutator).Parallel() |
| } |
| |
| type overrideBaseDependencyTag struct { |
| blueprint.BaseDependencyTag |
| } |
| |
| var overrideBaseDepTag overrideBaseDependencyTag |
| |
| // Adds dependency on the base module to the overriding module so that they can be visited in the |
| // next phase. |
| func overrideModuleDepsMutator(ctx BottomUpMutatorContext) { |
| if module, ok := ctx.Module().(OverrideModule); ok { |
| base := String(module.getOverrideModuleProperties().Base) |
| if !ctx.OtherModuleExists(base) { |
| ctx.PropertyErrorf("base", "%q is not a valid module name", base) |
| return |
| } |
| // See if there's a prebuilt module that overrides this override module with prefer flag, |
| // in which case we call HideFromMake on the corresponding variant later. |
| ctx.VisitDirectDepsWithTag(PrebuiltDepTag, func(dep Module) { |
| prebuilt := GetEmbeddedPrebuilt(dep) |
| if prebuilt == nil { |
| panic("PrebuiltDepTag leads to a non-prebuilt module " + dep.Name()) |
| } |
| if prebuilt.UsePrebuilt() { |
| module.setOverriddenByPrebuilt(true) |
| return |
| } |
| }) |
| baseModule := ctx.AddDependency(ctx.Module(), overrideBaseDepTag, *module.getOverrideModuleProperties().Base)[0] |
| if o, ok := baseModule.(OverridableModule); ok { |
| o.addOverride(ctx.Module().(OverrideModule)) |
| } |
| } |
| } |
| |
| // Now, goes through all overridable modules, finds all modules overriding them, creates a local |
| // variant for each of them, and performs the actual overriding operation by calling override(). |
| func performOverrideMutator(ctx BottomUpMutatorContext) { |
| if b, ok := ctx.Module().(OverridableModule); ok { |
| overrides := b.getOverrides() |
| if len(overrides) == 0 { |
| return |
| } |
| variants := make([]string, len(overrides)+1) |
| // The first variant is for the original, non-overridden, base module. |
| variants[0] = "" |
| for i, o := range overrides { |
| variants[i+1] = o.(Module).Name() |
| } |
| mods := ctx.CreateLocalVariations(variants...) |
| // Make the original variation the default one to depend on if no other override module variant |
| // is specified. |
| ctx.AliasVariation(variants[0]) |
| for i, o := range overrides { |
| mods[i+1].(OverridableModule).override(ctx, o) |
| if o.getOverriddenByPrebuilt() { |
| // The overriding module itself, too, is overridden by a prebuilt. Skip its installation. |
| mods[i+1].HideFromMake() |
| } |
| } |
| } else if o, ok := ctx.Module().(OverrideModule); ok { |
| // Create a variant of the overriding module with its own name. This matches the above local |
| // variant name rule for overridden modules, and thus allows ReplaceDependencies to match the |
| // two. |
| ctx.CreateLocalVariations(o.Name()) |
| // To allow dependencies to be added without having to know the above variation. |
| ctx.AliasVariation(o.Name()) |
| } |
| } |
| |
| func overridableModuleDepsMutator(ctx BottomUpMutatorContext) { |
| if b, ok := ctx.Module().(OverridableModule); ok && b.Enabled() { |
| b.OverridablePropertiesDepsMutator(ctx) |
| } |
| } |
| |
| func replaceDepsOnOverridingModuleMutator(ctx BottomUpMutatorContext) { |
| if b, ok := ctx.Module().(OverridableModule); ok { |
| if o := b.GetOverriddenBy(); o != "" { |
| // Redirect dependencies on the overriding module to this overridden module. Overriding |
| // modules are basically pseudo modules, and all build actions are associated to overridden |
| // modules. Therefore, dependencies on overriding modules need to be forwarded there as well. |
| ctx.ReplaceDependencies(o) |
| } |
| } |
| } |
| |
| // ModuleNameWithPossibleOverride returns the name of the OverrideModule that overrides the current |
| // variant of this OverridableModule, or ctx.ModuleName() if this module is not an OverridableModule |
| // or if this variant is not overridden. |
| func ModuleNameWithPossibleOverride(ctx ModuleContext) string { |
| if overridable, ok := ctx.Module().(OverridableModule); ok { |
| if o := overridable.GetOverriddenBy(); o != "" { |
| return o |
| } |
| } |
| return ctx.ModuleName() |
| } |