1// Copyright 2015 Google Inc. All rights reserved. 2// 3// Licensed under the Apache License, Version 2.0 (the "License"); 4// you may not use this file except in compliance with the License. 5// You may obtain a copy of the License at 6// 7// http://www.apache.org/licenses/LICENSE-2.0 8// 9// Unless required by applicable law or agreed to in writing, software 10// distributed under the License is distributed on an "AS IS" BASIS, 11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12// See the License for the specific language governing permissions and 13// limitations under the License. 14 15package android 16 17import ( 18 "reflect" 19 20 "github.com/google/blueprint" 21 "github.com/google/blueprint/proptools" 22) 23 24type defaultsDependencyTag struct { 25 blueprint.BaseDependencyTag 26} 27 28var DefaultsDepTag defaultsDependencyTag 29 30type defaultsProperties struct { 31 Defaults []string 32} 33 34type DefaultableModuleBase struct { 35 defaultsProperties defaultsProperties 36 defaultableProperties []interface{} 37 defaultableVariableProperties interface{} 38 39 // The optional hook to call after any defaults have been applied. 40 hook DefaultableHook 41} 42 43func (d *DefaultableModuleBase) defaults() *defaultsProperties { 44 return &d.defaultsProperties 45} 46 47func (d *DefaultableModuleBase) setProperties(props []interface{}, variableProperties interface{}) { 48 d.defaultableProperties = props 49 d.defaultableVariableProperties = variableProperties 50} 51 52func (d *DefaultableModuleBase) SetDefaultableHook(hook DefaultableHook) { 53 d.hook = hook 54} 55 56func (d *DefaultableModuleBase) callHookIfAvailable(ctx DefaultableHookContext) { 57 if d.hook != nil { 58 d.hook(ctx) 59 } 60} 61 62// Interface that must be supported by any module to which defaults can be applied. 63type Defaultable interface { 64 // Get a pointer to the struct containing the Defaults property. 65 defaults() *defaultsProperties 66 67 // Set the property structures into which defaults will be added. 68 setProperties(props []interface{}, variableProperties interface{}) 69 70 // Apply defaults from the supplied Defaults to the property structures supplied to 71 // setProperties(...). 72 applyDefaults(TopDownMutatorContext, []Defaults) 73 74 // Set the hook to be called after any defaults have been applied. 75 // 76 // Should be used in preference to a AddLoadHook when the behavior of the load 77 // hook is dependent on properties supplied in the Android.bp file. 78 SetDefaultableHook(hook DefaultableHook) 79 80 // Call the hook if specified. 81 callHookIfAvailable(context DefaultableHookContext) 82} 83 84type DefaultableModule interface { 85 Module 86 Defaultable 87} 88 89var _ Defaultable = (*DefaultableModuleBase)(nil) 90 91func InitDefaultableModule(module DefaultableModule) { 92 if module.(Module).base().module == nil { 93 panic("InitAndroidModule must be called before InitDefaultableModule") 94 } 95 module.setProperties(module.(Module).GetProperties(), module.(Module).base().variableProperties) 96 97 module.AddProperties(module.defaults()) 98 99 module.base().customizableProperties = module.GetProperties() 100} 101 102// A restricted subset of context methods, similar to LoadHookContext. 103type DefaultableHookContext interface { 104 EarlyModuleContext 105 106 CreateModule(ModuleFactory, ...interface{}) Module 107} 108 109type DefaultableHook func(ctx DefaultableHookContext) 110 111// The Defaults_visibility property. 112type DefaultsVisibilityProperties struct { 113 114 // Controls the visibility of the defaults module itself. 115 Defaults_visibility []string 116} 117 118type DefaultsModuleBase struct { 119 DefaultableModuleBase 120} 121 122// The common pattern for defaults modules is to register separate instances of 123// the xxxProperties structs in the AddProperties calls, rather than reusing the 124// ones inherited from Module. 125// 126// The effect is that e.g. myDefaultsModuleInstance.base().xxxProperties won't 127// contain the values that have been set for the defaults module. Rather, to 128// retrieve the values it is necessary to iterate over properties(). E.g. to get 129// the commonProperties instance that have the real values: 130// 131// d := myModule.(Defaults) 132// for _, props := range d.properties() { 133// if cp, ok := props.(*commonProperties); ok { 134// ... access property values in cp ... 135// } 136// } 137// 138// The rationale is that the properties on a defaults module apply to the 139// defaultable modules using it, not to the defaults module itself. E.g. setting 140// the "enabled" property false makes inheriting modules disabled by default, 141// rather than disabling the defaults module itself. 142type Defaults interface { 143 Defaultable 144 145 // Although this function is unused it is actually needed to ensure that only modules that embed 146 // DefaultsModuleBase will type-assert to the Defaults interface. 147 isDefaults() bool 148 149 // Get the structures containing the properties for which defaults can be provided. 150 properties() []interface{} 151 152 productVariableProperties() interface{} 153} 154 155func (d *DefaultsModuleBase) isDefaults() bool { 156 return true 157} 158 159type DefaultsModule interface { 160 Module 161 Defaults 162} 163 164func (d *DefaultsModuleBase) properties() []interface{} { 165 return d.defaultableProperties 166} 167 168func (d *DefaultsModuleBase) productVariableProperties() interface{} { 169 return d.defaultableVariableProperties 170} 171 172func (d *DefaultsModuleBase) GenerateAndroidBuildActions(ctx ModuleContext) { 173} 174 175func InitDefaultsModule(module DefaultsModule) { 176 commonProperties := &commonProperties{} 177 178 module.AddProperties( 179 &hostAndDeviceProperties{}, 180 commonProperties, 181 &ApexProperties{}, 182 &distProperties{}) 183 184 initAndroidModuleBase(module) 185 initProductVariableModule(module) 186 initArchModule(module) 187 InitDefaultableModule(module) 188 189 // Add properties that will not have defaults applied to them. 190 base := module.base() 191 defaultsVisibility := &DefaultsVisibilityProperties{} 192 module.AddProperties(&base.nameProperties, defaultsVisibility) 193 194 // Unlike non-defaults modules the visibility property is not stored in m.base().commonProperties. 195 // Instead it is stored in a separate instance of commonProperties created above so clear the 196 // existing list of properties. 197 clearVisibilityProperties(module) 198 199 // The defaults_visibility property controls the visibility of a defaults module so it must be 200 // set as the primary property, which also adds it to the list. 201 setPrimaryVisibilityProperty(module, "defaults_visibility", &defaultsVisibility.Defaults_visibility) 202 203 // The visibility property needs to be checked (but not parsed) by the visibility module during 204 // its checking phase and parsing phase so add it to the list as a normal property. 205 AddVisibilityProperty(module, "visibility", &commonProperties.Visibility) 206 207 // The applicable licenses property for defaults is 'licenses'. 208 setPrimaryLicensesProperty(module, "licenses", &commonProperties.Licenses) 209 210 base.module = module 211} 212 213var _ Defaults = (*DefaultsModuleBase)(nil) 214 215func (defaultable *DefaultableModuleBase) applyDefaults(ctx TopDownMutatorContext, 216 defaultsList []Defaults) { 217 218 for _, defaults := range defaultsList { 219 for _, prop := range defaultable.defaultableProperties { 220 if prop == defaultable.defaultableVariableProperties { 221 defaultable.applyDefaultVariableProperties(ctx, defaults, prop) 222 } else { 223 defaultable.applyDefaultProperties(ctx, defaults, prop) 224 } 225 } 226 } 227} 228 229// Product variable properties need special handling, the type of the filtered product variable 230// property struct may not be identical between the defaults module and the defaultable module. 231// Use PrependMatchingProperties to apply whichever properties match. 232func (defaultable *DefaultableModuleBase) applyDefaultVariableProperties(ctx TopDownMutatorContext, 233 defaults Defaults, defaultableProp interface{}) { 234 if defaultableProp == nil { 235 return 236 } 237 238 defaultsProp := defaults.productVariableProperties() 239 if defaultsProp == nil { 240 return 241 } 242 243 dst := []interface{}{ 244 defaultableProp, 245 // Put an empty copy of the src properties into dst so that properties in src that are not in dst 246 // don't cause a "failed to find property to extend" error. 247 proptools.CloneEmptyProperties(reflect.ValueOf(defaultsProp)).Interface(), 248 } 249 250 err := proptools.PrependMatchingProperties(dst, defaultsProp, nil) 251 if err != nil { 252 if propertyErr, ok := err.(*proptools.ExtendPropertyError); ok { 253 ctx.PropertyErrorf(propertyErr.Property, "%s", propertyErr.Err.Error()) 254 } else { 255 panic(err) 256 } 257 } 258} 259 260func (defaultable *DefaultableModuleBase) applyDefaultProperties(ctx TopDownMutatorContext, 261 defaults Defaults, defaultableProp interface{}) { 262 263 for _, def := range defaults.properties() { 264 if proptools.TypeEqual(defaultableProp, def) { 265 err := proptools.PrependProperties(defaultableProp, def, nil) 266 if err != nil { 267 if propertyErr, ok := err.(*proptools.ExtendPropertyError); ok { 268 ctx.PropertyErrorf(propertyErr.Property, "%s", propertyErr.Err.Error()) 269 } else { 270 panic(err) 271 } 272 } 273 } 274 } 275} 276 277func RegisterDefaultsPreArchMutators(ctx RegisterMutatorsContext) { 278 ctx.BottomUp("defaults_deps", defaultsDepsMutator).Parallel() 279 ctx.TopDown("defaults", defaultsMutator).Parallel() 280} 281 282func defaultsDepsMutator(ctx BottomUpMutatorContext) { 283 if defaultable, ok := ctx.Module().(Defaultable); ok { 284 ctx.AddDependency(ctx.Module(), DefaultsDepTag, defaultable.defaults().Defaults...) 285 } 286} 287 288func defaultsMutator(ctx TopDownMutatorContext) { 289 if defaultable, ok := ctx.Module().(Defaultable); ok { 290 if len(defaultable.defaults().Defaults) > 0 { 291 var defaultsList []Defaults 292 seen := make(map[Defaults]bool) 293 294 ctx.WalkDeps(func(module, parent Module) bool { 295 if ctx.OtherModuleDependencyTag(module) == DefaultsDepTag { 296 if defaults, ok := module.(Defaults); ok { 297 if !seen[defaults] { 298 seen[defaults] = true 299 defaultsList = append(defaultsList, defaults) 300 return len(defaults.defaults().Defaults) > 0 301 } 302 } else { 303 ctx.PropertyErrorf("defaults", "module %s is not an defaults module", 304 ctx.OtherModuleName(module)) 305 } 306 } 307 return false 308 }) 309 defaultable.applyDefaults(ctx, defaultsList) 310 } 311 312 defaultable.callHookIfAvailable(ctx) 313 } 314} 315