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.base().module == nil { 93 panic("InitAndroidModule must be called before InitDefaultableModule") 94 } 95 96 module.setProperties(module.GetProperties(), module.base().variableProperties) 97 98 module.AddProperties(module.defaults()) 99} 100 101// A restricted subset of context methods, similar to LoadHookContext. 102type DefaultableHookContext interface { 103 EarlyModuleContext 104 105 CreateModule(ModuleFactory, ...interface{}) Module 106 AddMissingDependencies(missingDeps []string) 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 174func InitDefaultsModule(module DefaultsModule) { 175 commonProperties := &commonProperties{} 176 177 module.AddProperties( 178 &hostAndDeviceProperties{}, 179 commonProperties, 180 &ApexProperties{}, 181 &distProperties{}) 182 183 initAndroidModuleBase(module) 184 initProductVariableModule(module) 185 initArchModule(module) 186 InitDefaultableModule(module) 187 188 // Add properties that will not have defaults applied to them. 189 base := module.base() 190 defaultsVisibility := &DefaultsVisibilityProperties{} 191 module.AddProperties(&base.nameProperties, defaultsVisibility) 192 193 // Unlike non-defaults modules the visibility property is not stored in m.base().commonProperties. 194 // Instead it is stored in a separate instance of commonProperties created above so clear the 195 // existing list of properties. 196 clearVisibilityProperties(module) 197 198 // The defaults_visibility property controls the visibility of a defaults module so it must be 199 // set as the primary property, which also adds it to the list. 200 setPrimaryVisibilityProperty(module, "defaults_visibility", &defaultsVisibility.Defaults_visibility) 201 202 // The visibility property needs to be checked (but not parsed) by the visibility module during 203 // its checking phase and parsing phase so add it to the list as a normal property. 204 AddVisibilityProperty(module, "visibility", &commonProperties.Visibility) 205 206 // The applicable licenses property for defaults is 'licenses'. 207 setPrimaryLicensesProperty(module, "licenses", &commonProperties.Licenses) 208} 209 210var _ Defaults = (*DefaultsModuleBase)(nil) 211 212func (defaultable *DefaultableModuleBase) applyDefaults(ctx TopDownMutatorContext, 213 defaultsList []Defaults) { 214 215 for _, defaults := range defaultsList { 216 for _, prop := range defaultable.defaultableProperties { 217 if prop == defaultable.defaultableVariableProperties { 218 defaultable.applyDefaultVariableProperties(ctx, defaults, prop) 219 } else { 220 defaultable.applyDefaultProperties(ctx, defaults, prop) 221 } 222 } 223 } 224} 225 226// Product variable properties need special handling, the type of the filtered product variable 227// property struct may not be identical between the defaults module and the defaultable module. 228// Use PrependMatchingProperties to apply whichever properties match. 229func (defaultable *DefaultableModuleBase) applyDefaultVariableProperties(ctx TopDownMutatorContext, 230 defaults Defaults, defaultableProp interface{}) { 231 if defaultableProp == nil { 232 return 233 } 234 235 defaultsProp := defaults.productVariableProperties() 236 if defaultsProp == nil { 237 return 238 } 239 240 dst := []interface{}{ 241 defaultableProp, 242 // Put an empty copy of the src properties into dst so that properties in src that are not in dst 243 // don't cause a "failed to find property to extend" error. 244 proptools.CloneEmptyProperties(reflect.ValueOf(defaultsProp)).Interface(), 245 } 246 247 err := proptools.PrependMatchingProperties(dst, defaultsProp, nil) 248 if err != nil { 249 if propertyErr, ok := err.(*proptools.ExtendPropertyError); ok { 250 ctx.PropertyErrorf(propertyErr.Property, "%s", propertyErr.Err.Error()) 251 } else { 252 panic(err) 253 } 254 } 255} 256 257func (defaultable *DefaultableModuleBase) applyDefaultProperties(ctx TopDownMutatorContext, 258 defaults Defaults, defaultableProp interface{}) { 259 260 for _, def := range defaults.properties() { 261 if proptools.TypeEqual(defaultableProp, def) { 262 err := proptools.PrependProperties(defaultableProp, def, nil) 263 if err != nil { 264 if propertyErr, ok := err.(*proptools.ExtendPropertyError); ok { 265 ctx.PropertyErrorf(propertyErr.Property, "%s", propertyErr.Err.Error()) 266 } else { 267 panic(err) 268 } 269 } 270 } 271 } 272} 273 274func RegisterDefaultsPreArchMutators(ctx RegisterMutatorsContext) { 275 ctx.BottomUp("defaults_deps", defaultsDepsMutator).Parallel() 276 ctx.TopDown("defaults", defaultsMutator).Parallel() 277} 278 279func defaultsDepsMutator(ctx BottomUpMutatorContext) { 280 if defaultable, ok := ctx.Module().(Defaultable); ok { 281 ctx.AddDependency(ctx.Module(), DefaultsDepTag, defaultable.defaults().Defaults...) 282 } 283} 284 285func defaultsMutator(ctx TopDownMutatorContext) { 286 if defaultable, ok := ctx.Module().(Defaultable); ok { 287 if len(defaultable.defaults().Defaults) > 0 { 288 var defaultsList []Defaults 289 seen := make(map[Defaults]bool) 290 291 ctx.WalkDeps(func(module, parent Module) bool { 292 if ctx.OtherModuleDependencyTag(module) == DefaultsDepTag { 293 if defaults, ok := module.(Defaults); ok { 294 if !seen[defaults] { 295 seen[defaults] = true 296 defaultsList = append(defaultsList, defaults) 297 return len(defaults.defaults().Defaults) > 0 298 } 299 } else { 300 ctx.PropertyErrorf("defaults", "module %s is not an defaults module", 301 ctx.OtherModuleName(module)) 302 } 303 } 304 return false 305 }) 306 defaultable.applyDefaults(ctx, defaultsList) 307 } 308 309 defaultable.CallHookIfAvailable(ctx) 310 } 311} 312