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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	// Included to support setting bazel_module.label for multiple Soong modules to the same Bazel
122	// target. This is primarily useful for modules that were architecture specific and instead are
123	// handled in Bazel as a select().
124	BazelModuleBase
125}
126
127// The common pattern for defaults modules is to register separate instances of
128// the xxxProperties structs in the AddProperties calls, rather than reusing the
129// ones inherited from Module.
130//
131// The effect is that e.g. myDefaultsModuleInstance.base().xxxProperties won't
132// contain the values that have been set for the defaults module. Rather, to
133// retrieve the values it is necessary to iterate over properties(). E.g. to get
134// the commonProperties instance that have the real values:
135//
136//   d := myModule.(Defaults)
137//   for _, props := range d.properties() {
138//     if cp, ok := props.(*commonProperties); ok {
139//       ... access property values in cp ...
140//     }
141//   }
142//
143// The rationale is that the properties on a defaults module apply to the
144// defaultable modules using it, not to the defaults module itself. E.g. setting
145// the "enabled" property false makes inheriting modules disabled by default,
146// rather than disabling the defaults module itself.
147type Defaults interface {
148	Defaultable
149
150	// Although this function is unused it is actually needed to ensure that only modules that embed
151	// DefaultsModuleBase will type-assert to the Defaults interface.
152	isDefaults() bool
153
154	// Get the structures containing the properties for which defaults can be provided.
155	properties() []interface{}
156
157	productVariableProperties() interface{}
158}
159
160func (d *DefaultsModuleBase) isDefaults() bool {
161	return true
162}
163
164type DefaultsModule interface {
165	Module
166	Defaults
167	Bazelable
168}
169
170func (d *DefaultsModuleBase) properties() []interface{} {
171	return d.defaultableProperties
172}
173
174func (d *DefaultsModuleBase) productVariableProperties() interface{} {
175	return d.defaultableVariableProperties
176}
177
178func (d *DefaultsModuleBase) GenerateAndroidBuildActions(ctx ModuleContext) {}
179
180// ConvertWithBp2build to fulfill Bazelable interface; however, at this time defaults module are
181// *NOT* converted with bp2build
182func (defaultable *DefaultsModuleBase) ConvertWithBp2build(ctx TopDownMutatorContext) {}
183
184func InitDefaultsModule(module DefaultsModule) {
185	commonProperties := &commonProperties{}
186
187	module.AddProperties(
188		&hostAndDeviceProperties{},
189		commonProperties,
190		&ApexProperties{},
191		&distProperties{})
192
193	// Bazel module must be initialized _before_ Defaults to be included in cc_defaults module.
194	InitBazelModule(module)
195	initAndroidModuleBase(module)
196	initProductVariableModule(module)
197	initArchModule(module)
198	InitDefaultableModule(module)
199
200	// Add properties that will not have defaults applied to them.
201	base := module.base()
202	defaultsVisibility := &DefaultsVisibilityProperties{}
203	module.AddProperties(&base.nameProperties, defaultsVisibility)
204
205	// Unlike non-defaults modules the visibility property is not stored in m.base().commonProperties.
206	// Instead it is stored in a separate instance of commonProperties created above so clear the
207	// existing list of properties.
208	clearVisibilityProperties(module)
209
210	// The defaults_visibility property controls the visibility of a defaults module so it must be
211	// set as the primary property, which also adds it to the list.
212	setPrimaryVisibilityProperty(module, "defaults_visibility", &defaultsVisibility.Defaults_visibility)
213
214	// The visibility property needs to be checked (but not parsed) by the visibility module during
215	// its checking phase and parsing phase so add it to the list as a normal property.
216	AddVisibilityProperty(module, "visibility", &commonProperties.Visibility)
217
218	// The applicable licenses property for defaults is 'licenses'.
219	setPrimaryLicensesProperty(module, "licenses", &commonProperties.Licenses)
220
221}
222
223var _ Defaults = (*DefaultsModuleBase)(nil)
224
225// applyNamespacedVariableDefaults only runs in bp2build mode for
226// defaultable/defaults modules. Its purpose is to merge namespaced product
227// variable props from defaults deps, even if those defaults are custom module
228// types created from soong_config_module_type, e.g. one that's wrapping a
229// cc_defaults or java_defaults.
230func applyNamespacedVariableDefaults(defaultDep Defaults, ctx TopDownMutatorContext) {
231	var dep, b Bazelable
232
233	dep, ok := defaultDep.(Bazelable)
234	if !ok {
235		if depMod, ok := defaultDep.(Module); ok {
236			// Track that this dependency hasn't been converted to bp2build yet.
237			ctx.AddUnconvertedBp2buildDep(depMod.Name())
238			return
239		} else {
240			panic("Expected default dep to be a Module.")
241		}
242	}
243
244	b, ok = ctx.Module().(Bazelable)
245	if !ok {
246		return
247	}
248
249	// namespacedVariableProps is a map from namespaces (e.g. acme, android,
250	// vendor_foo) to a slice of soong_config_variable struct pointers,
251	// containing properties for that particular module.
252	src := dep.namespacedVariableProps()
253	dst := b.namespacedVariableProps()
254	if dst == nil {
255		dst = make(namespacedVariableProperties)
256	}
257
258	// Propagate all soong_config_variable structs from the dep. We'll merge the
259	// actual property values later in variable.go.
260	for namespace := range src {
261		if dst[namespace] == nil {
262			dst[namespace] = []interface{}{}
263		}
264		for _, i := range src[namespace] {
265			dst[namespace] = append(dst[namespace], i)
266		}
267	}
268
269	b.setNamespacedVariableProps(dst)
270}
271
272func (defaultable *DefaultableModuleBase) applyDefaults(ctx TopDownMutatorContext,
273	defaultsList []Defaults) {
274
275	for _, defaults := range defaultsList {
276		if ctx.Config().runningAsBp2Build {
277			applyNamespacedVariableDefaults(defaults, ctx)
278		}
279		for _, prop := range defaultable.defaultableProperties {
280			if prop == defaultable.defaultableVariableProperties {
281				defaultable.applyDefaultVariableProperties(ctx, defaults, prop)
282			} else {
283				defaultable.applyDefaultProperties(ctx, defaults, prop)
284			}
285		}
286	}
287}
288
289// Product variable properties need special handling, the type of the filtered product variable
290// property struct may not be identical between the defaults module and the defaultable module.
291// Use PrependMatchingProperties to apply whichever properties match.
292func (defaultable *DefaultableModuleBase) applyDefaultVariableProperties(ctx TopDownMutatorContext,
293	defaults Defaults, defaultableProp interface{}) {
294	if defaultableProp == nil {
295		return
296	}
297
298	defaultsProp := defaults.productVariableProperties()
299	if defaultsProp == nil {
300		return
301	}
302
303	dst := []interface{}{
304		defaultableProp,
305		// Put an empty copy of the src properties into dst so that properties in src that are not in dst
306		// don't cause a "failed to find property to extend" error.
307		proptools.CloneEmptyProperties(reflect.ValueOf(defaultsProp)).Interface(),
308	}
309
310	err := proptools.PrependMatchingProperties(dst, defaultsProp, nil)
311	if err != nil {
312		if propertyErr, ok := err.(*proptools.ExtendPropertyError); ok {
313			ctx.PropertyErrorf(propertyErr.Property, "%s", propertyErr.Err.Error())
314		} else {
315			panic(err)
316		}
317	}
318}
319
320func (defaultable *DefaultableModuleBase) applyDefaultProperties(ctx TopDownMutatorContext,
321	defaults Defaults, defaultableProp interface{}) {
322
323	for _, def := range defaults.properties() {
324		if proptools.TypeEqual(defaultableProp, def) {
325			err := proptools.PrependProperties(defaultableProp, def, nil)
326			if err != nil {
327				if propertyErr, ok := err.(*proptools.ExtendPropertyError); ok {
328					ctx.PropertyErrorf(propertyErr.Property, "%s", propertyErr.Err.Error())
329				} else {
330					panic(err)
331				}
332			}
333		}
334	}
335}
336
337func RegisterDefaultsPreArchMutators(ctx RegisterMutatorsContext) {
338	ctx.BottomUp("defaults_deps", defaultsDepsMutator).Parallel()
339	ctx.TopDown("defaults", defaultsMutator).Parallel()
340}
341
342func defaultsDepsMutator(ctx BottomUpMutatorContext) {
343	if defaultable, ok := ctx.Module().(Defaultable); ok {
344		ctx.AddDependency(ctx.Module(), DefaultsDepTag, defaultable.defaults().Defaults...)
345	}
346}
347
348func defaultsMutator(ctx TopDownMutatorContext) {
349	if defaultable, ok := ctx.Module().(Defaultable); ok {
350		if len(defaultable.defaults().Defaults) > 0 {
351			var defaultsList []Defaults
352			seen := make(map[Defaults]bool)
353
354			ctx.WalkDeps(func(module, parent Module) bool {
355				if ctx.OtherModuleDependencyTag(module) == DefaultsDepTag {
356					if defaults, ok := module.(Defaults); ok {
357						if !seen[defaults] {
358							seen[defaults] = true
359							defaultsList = append(defaultsList, defaults)
360							return len(defaults.defaults().Defaults) > 0
361						}
362					} else {
363						ctx.PropertyErrorf("defaults", "module %s is not an defaults module",
364							ctx.OtherModuleName(module))
365					}
366				}
367				return false
368			})
369			defaultable.applyDefaults(ctx, defaultsList)
370		}
371
372		defaultable.callHookIfAvailable(ctx)
373	}
374}
375