xref: /aosp_15_r20/build/soong/android/apex.go (revision 333d2b3687b3a337dbcca9d65000bca186795e39)
1 // Copyright 2018 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 
15 package android
16 
17 import (
18 	"fmt"
19 	"slices"
20 	"sort"
21 	"strconv"
22 	"strings"
23 	"sync"
24 
25 	"github.com/google/blueprint"
26 )
27 
28 var (
29 	// This is the sdk version when APEX was first introduced
30 	SdkVersion_Android10 = uncheckedFinalApiLevel(29)
31 )
32 
33 // ApexInfo describes the metadata about one or more apexBundles that an apex variant of a module is
34 // part of.  When an apex variant is created, the variant is associated with one apexBundle. But
35 // when multiple apex variants are merged for deduping (see mergeApexVariations), this holds the
36 // information about the apexBundles that are merged together.
37 // Accessible via `ctx.Provider(android.ApexInfoProvider).(android.ApexInfo)`
38 type ApexInfo struct {
39 	// Name of the apex variation that this module (i.e. the apex variant of the module) is
40 	// mutated into, or "" for a platform (i.e. non-APEX) variant.
41 	//
42 	// Also note that a module can be included in multiple APEXes, in which case, the module is
43 	// mutated into one or more variants, each of which is for an APEX. The variants then can
44 	// later be deduped if they don't need to be compiled differently. This is an optimization
45 	// done in mergeApexVariations.
46 	ApexVariationName string
47 
48 	// ApiLevel that this module has to support at minimum.
49 	MinSdkVersion ApiLevel
50 
51 	// True if this module comes from an updatable apexBundle.
52 	Updatable bool
53 
54 	// True if this module can use private platform APIs. Only non-updatable APEX can set this
55 	// to true.
56 	UsePlatformApis bool
57 
58 	// List of Apex variant names that this module is associated with. This initially is the
59 	// same as the `ApexVariationName` field.  Then when multiple apex variants are merged in
60 	// mergeApexVariations, ApexInfo struct of the merged variant holds the list of apexBundles
61 	// that are merged together.
62 	InApexVariants []string
63 
64 	// True if this is for a prebuilt_apex.
65 	//
66 	// If true then this will customize the apex processing to make it suitable for handling
67 	// prebuilt_apex, e.g. it will prevent ApexInfos from being merged together.
68 	//
69 	// See Prebuilt.ApexInfoMutator for more information.
70 	ForPrebuiltApex bool
71 
72 	// Returns the name of the test apexes that this module is included in.
73 	TestApexes []string
74 
75 	// Returns the name of the overridden apex (com.android.foo)
76 	BaseApexName string
77 
78 	// Returns the value of `apex_available_name`
79 	ApexAvailableName string
80 }
81 
82 // AllApexInfo holds the ApexInfo of all apexes that include this module.
83 type AllApexInfo struct {
84 	ApexInfos []ApexInfo
85 }
86 
87 var ApexInfoProvider = blueprint.NewMutatorProvider[ApexInfo]("apex_mutate")
88 var AllApexInfoProvider = blueprint.NewMutatorProvider[*AllApexInfo]("apex_info")
89 
90 func (i ApexInfo) AddJSONData(d *map[string]interface{}) {
91 	(*d)["Apex"] = map[string]interface{}{
92 		"ApexVariationName": i.ApexVariationName,
93 		"MinSdkVersion":     i.MinSdkVersion,
94 		"InApexVariants":    i.InApexVariants,
95 		"ForPrebuiltApex":   i.ForPrebuiltApex,
96 	}
97 }
98 
99 // mergedName gives the name of the alias variation that will be used when multiple apex variations
100 // of a module can be deduped into one variation. For example, if libfoo is included in both apex.a
101 // and apex.b, and if the two APEXes have the same min_sdk_version (say 29), then libfoo doesn't
102 // have to be built twice, but only once. In that case, the two apex variations apex.a and apex.b
103 // are configured to have the same alias variation named apex29. Whether platform APIs is allowed
104 // or not also matters; if two APEXes don't have the same allowance, they get different names and
105 // thus wouldn't be merged.
106 func (i ApexInfo) mergedName() string {
107 	name := "apex" + strconv.Itoa(i.MinSdkVersion.FinalOrFutureInt())
108 	return name
109 }
110 
111 // IsForPlatform tells whether this module is for the platform or not. If false is returned, it
112 // means that this apex variant of the module is built for an APEX.
113 func (i ApexInfo) IsForPlatform() bool {
114 	return i.ApexVariationName == ""
115 }
116 
117 // InApexVariant tells whether this apex variant of the module is part of the given apexVariant or
118 // not.
119 func (i ApexInfo) InApexVariant(apexVariant string) bool {
120 	for _, a := range i.InApexVariants {
121 		if a == apexVariant {
122 			return true
123 		}
124 	}
125 	return false
126 }
127 
128 // To satisfy the comparable interface
129 func (i ApexInfo) Equal(other any) bool {
130 	otherApexInfo, ok := other.(ApexInfo)
131 	return ok && i.ApexVariationName == otherApexInfo.ApexVariationName &&
132 		i.MinSdkVersion == otherApexInfo.MinSdkVersion &&
133 		i.Updatable == otherApexInfo.Updatable &&
134 		i.UsePlatformApis == otherApexInfo.UsePlatformApis &&
135 		slices.Equal(i.InApexVariants, otherApexInfo.InApexVariants)
136 }
137 
138 // ApexBundleInfo contains information about the dependencies of an apex
139 type ApexBundleInfo struct {
140 }
141 
142 var ApexBundleInfoProvider = blueprint.NewMutatorProvider[ApexBundleInfo]("apex_info")
143 
144 // DepIsInSameApex defines an interface that should be used to determine whether a given dependency
145 // should be considered as part of the same APEX as the current module or not. Note: this was
146 // extracted from ApexModule to make it easier to define custom subsets of the ApexModule interface
147 // and improve code navigation within the IDE.
148 type DepIsInSameApex interface {
149 	// DepIsInSameApex tests if the other module 'dep' is considered as part of the same APEX as
150 	// this module. For example, a static lib dependency usually returns true here, while a
151 	// shared lib dependency to a stub library returns false.
152 	//
153 	// This method must not be called directly without first ignoring dependencies whose tags
154 	// implement ExcludeFromApexContentsTag. Calls from within the func passed to WalkPayloadDeps()
155 	// are fine as WalkPayloadDeps() will ignore those dependencies automatically. Otherwise, use
156 	// IsDepInSameApex instead.
157 	DepIsInSameApex(ctx BaseModuleContext, dep Module) bool
158 }
159 
160 func IsDepInSameApex(ctx BaseModuleContext, module, dep Module) bool {
161 	depTag := ctx.OtherModuleDependencyTag(dep)
162 	if _, ok := depTag.(ExcludeFromApexContentsTag); ok {
163 		// The tag defines a dependency that never requires the child module to be part of the same
164 		// apex as the parent.
165 		return false
166 	}
167 	return module.(DepIsInSameApex).DepIsInSameApex(ctx, dep)
168 }
169 
170 // ApexModule is the interface that a module type is expected to implement if the module has to be
171 // built differently depending on whether the module is destined for an APEX or not (i.e., installed
172 // to one of the regular partitions).
173 //
174 // Native shared libraries are one such module type; when it is built for an APEX, it should depend
175 // only on stable interfaces such as NDK, stable AIDL, or C APIs from other APEXes.
176 //
177 // A module implementing this interface will be mutated into multiple variations by apex.apexMutator
178 // if it is directly or indirectly included in one or more APEXes. Specifically, if a module is
179 // included in apex.foo and apex.bar then three apex variants are created: platform, apex.foo and
180 // apex.bar. The platform variant is for the regular partitions (e.g., /system or /vendor, etc.)
181 // while the other two are for the APEXs, respectively. The latter two variations can be merged (see
182 // mergedName) when the two APEXes have the same min_sdk_version requirement.
183 type ApexModule interface {
184 	Module
185 	DepIsInSameApex
186 
187 	apexModuleBase() *ApexModuleBase
188 
189 	// Marks that this module should be built for the specified APEX. Call this BEFORE
190 	// apex.apexMutator is run.
191 	BuildForApex(apex ApexInfo)
192 
193 	// Returns true if this module is present in any APEX either directly or indirectly. Call
194 	// this after apex.apexMutator is run.
195 	InAnyApex() bool
196 
197 	// NotInPlatform returns true if the module is not available to the platform due to
198 	// apex_available being set and not containing "//apex_available:platform".
199 	NotInPlatform() bool
200 
201 	// Tests if this module could have APEX variants. Even when a module type implements
202 	// ApexModule interface, APEX variants are created only for the module instances that return
203 	// true here. This is useful for not creating APEX variants for certain types of shared
204 	// libraries such as NDK stubs.
205 	CanHaveApexVariants() bool
206 
207 	// Tests if this module can be installed to APEX as a file. For example, this would return
208 	// true for shared libs while return false for static libs because static libs are not
209 	// installable module (but it can still be mutated for APEX)
210 	IsInstallableToApex() bool
211 
212 	// Tests if this module is available for the specified APEX or ":platform". This is from the
213 	// apex_available property of the module.
214 	AvailableFor(what string) bool
215 
216 	// AlwaysRequiresPlatformApexVariant allows the implementing module to determine whether an
217 	// APEX mutator should always be created for it.
218 	//
219 	// Returns false by default.
220 	AlwaysRequiresPlatformApexVariant() bool
221 
222 	// Returns true if this module is not available to platform (i.e. apex_available property
223 	// doesn't have "//apex_available:platform"), or shouldn't be available to platform, which
224 	// is the case when this module depends on other module that isn't available to platform.
225 	NotAvailableForPlatform() bool
226 
227 	// Marks that this module is not available to platform. Set by the
228 	// check-platform-availability mutator in the apex package.
229 	SetNotAvailableForPlatform()
230 
231 	// Returns nil (success) if this module should support the given sdk version. Returns an
232 	// error if not. No default implementation is provided for this method. A module type
233 	// implementing this interface should provide an implementation. A module supports an sdk
234 	// version when the module's min_sdk_version is equal to or less than the given sdk version.
235 	ShouldSupportSdkVersion(ctx BaseModuleContext, sdkVersion ApiLevel) error
236 
237 	// Returns true if this module needs a unique variation per apex, effectively disabling the
238 	// deduping. This is turned on when, for example if use_apex_name_macro is set so that each
239 	// apex variant should be built with different macro definitions.
240 	UniqueApexVariations() bool
241 }
242 
243 // Properties that are common to all module types implementing ApexModule interface.
244 type ApexProperties struct {
245 	// Availability of this module in APEXes. Only the listed APEXes can contain this module. If
246 	// the module has stubs then other APEXes and the platform may access it through them
247 	// (subject to visibility).
248 	//
249 	// "//apex_available:anyapex" is a pseudo APEX name that matches to any APEX.
250 	// "//apex_available:platform" refers to non-APEX partitions like "system.img".
251 	// Prefix pattern (com.foo.*) can be used to match with any APEX name with the prefix(com.foo.).
252 	// Default is ["//apex_available:platform"].
253 	Apex_available []string
254 
255 	// See ApexModule.NotAvailableForPlatform()
256 	NotAvailableForPlatform bool `blueprint:"mutated"`
257 
258 	// See ApexModule.UniqueApexVariants()
259 	UniqueApexVariationsForDeps bool `blueprint:"mutated"`
260 
261 	// The test apexes that includes this apex variant
262 	TestApexes []string `blueprint:"mutated"`
263 }
264 
265 // Marker interface that identifies dependencies that are excluded from APEX contents.
266 //
267 // Unless the tag also implements the AlwaysRequireApexVariantTag this will prevent an apex variant
268 // from being created for the module.
269 //
270 // At the moment the sdk.sdkRequirementsMutator relies on the fact that the existing tags which
271 // implement this interface do not define dependencies onto members of an sdk_snapshot. If that
272 // changes then sdk.sdkRequirementsMutator will need fixing.
273 type ExcludeFromApexContentsTag interface {
274 	blueprint.DependencyTag
275 
276 	// Method that differentiates this interface from others.
277 	ExcludeFromApexContents()
278 }
279 
280 // Marker interface that identifies dependencies that always requires an APEX variant to be created.
281 //
282 // It is possible for a dependency to require an apex variant but exclude the module from the APEX
283 // contents. See sdk.sdkMemberDependencyTag.
284 type AlwaysRequireApexVariantTag interface {
285 	blueprint.DependencyTag
286 
287 	// Return true if this tag requires that the target dependency has an apex variant.
288 	AlwaysRequireApexVariant() bool
289 }
290 
291 // Interface that identifies dependencies to skip Apex dependency check
292 type SkipApexAllowedDependenciesCheck interface {
293 	// Returns true to skip the Apex dependency check, which limits the allowed dependency in build.
294 	SkipApexAllowedDependenciesCheck() bool
295 }
296 
297 // ApexModuleBase provides the default implementation for the ApexModule interface. APEX-aware
298 // modules are expected to include this struct and call InitApexModule().
299 type ApexModuleBase struct {
300 	ApexProperties     ApexProperties
301 	apexPropertiesLock sync.Mutex // protects ApexProperties during parallel apexDirectlyInAnyMutator
302 
303 	canHaveApexVariants bool
304 
305 	apexInfos     []ApexInfo
306 	apexInfosLock sync.Mutex // protects apexInfos during parallel apexInfoMutator
307 }
308 
309 // Initializes ApexModuleBase struct. Not calling this (even when inheriting from ApexModuleBase)
310 // prevents the module from being mutated for apexBundle.
311 func InitApexModule(m ApexModule) {
312 	base := m.apexModuleBase()
313 	base.canHaveApexVariants = true
314 
315 	m.AddProperties(&base.ApexProperties)
316 }
317 
318 // Implements ApexModule
319 func (m *ApexModuleBase) apexModuleBase() *ApexModuleBase {
320 	return m
321 }
322 
323 var (
324 	availableToPlatformList = []string{AvailableToPlatform}
325 )
326 
327 // Implements ApexModule
328 func (m *ApexModuleBase) ApexAvailable() []string {
329 	aa := m.ApexProperties.Apex_available
330 	if len(aa) > 0 {
331 		return aa
332 	}
333 	// Default is availability to platform
334 	return CopyOf(availableToPlatformList)
335 }
336 
337 // Implements ApexModule
338 func (m *ApexModuleBase) BuildForApex(apex ApexInfo) {
339 	m.apexInfosLock.Lock()
340 	defer m.apexInfosLock.Unlock()
341 	if slices.ContainsFunc(m.apexInfos, func(existing ApexInfo) bool {
342 		return existing.ApexVariationName == apex.ApexVariationName
343 	}) {
344 		return
345 	}
346 	m.apexInfos = append(m.apexInfos, apex)
347 }
348 
349 // Implements ApexModule
350 func (m *ApexModuleBase) InAnyApex() bool {
351 	for _, apex_name := range m.ApexProperties.Apex_available {
352 		if apex_name != AvailableToPlatform {
353 			return true
354 		}
355 	}
356 	return false
357 }
358 
359 // Implements ApexModule
360 func (m *ApexModuleBase) NotInPlatform() bool {
361 	return !m.AvailableFor(AvailableToPlatform)
362 }
363 
364 // Implements ApexModule
365 func (m *ApexModuleBase) CanHaveApexVariants() bool {
366 	return m.canHaveApexVariants
367 }
368 
369 // Implements ApexModule
370 func (m *ApexModuleBase) IsInstallableToApex() bool {
371 	// If needed, this will bel overridden by concrete types inheriting
372 	// ApexModuleBase
373 	return false
374 }
375 
376 // Returns the test apexes that this module is included in.
377 func (m *ApexModuleBase) TestApexes() []string {
378 	return m.ApexProperties.TestApexes
379 }
380 
381 // Implements ApexModule
382 func (m *ApexModuleBase) UniqueApexVariations() bool {
383 	// If needed, this will bel overridden by concrete types inheriting
384 	// ApexModuleBase
385 	return false
386 }
387 
388 // Implements ApexModule
389 func (m *ApexModuleBase) DepIsInSameApex(ctx BaseModuleContext, dep Module) bool {
390 	// By default, if there is a dependency from A to B, we try to include both in the same
391 	// APEX, unless B is explicitly from outside of the APEX (i.e. a stubs lib). Thus, returning
392 	// true. This is overridden by some module types like apex.ApexBundle, cc.Module,
393 	// java.Module, etc.
394 	return true
395 }
396 
397 const (
398 	AvailableToPlatform = "//apex_available:platform"
399 	AvailableToAnyApex  = "//apex_available:anyapex"
400 )
401 
402 // CheckAvailableForApex provides the default algorithm for checking the apex availability. When the
403 // availability is empty, it defaults to ["//apex_available:platform"] which means "available to the
404 // platform but not available to any APEX". When the list is not empty, `what` is matched against
405 // the list. If there is any matching element in the list, thus function returns true. The special
406 // availability "//apex_available:anyapex" matches with anything except for
407 // "//apex_available:platform".
408 func CheckAvailableForApex(what string, apex_available []string) bool {
409 	if len(apex_available) == 0 {
410 		return what == AvailableToPlatform
411 	}
412 
413 	// TODO b/248601389
414 	if what == "com.google.mainline.primary.libs" || what == "com.google.mainline.go.primary.libs" {
415 		return true
416 	}
417 
418 	for _, apex_name := range apex_available {
419 		// exact match.
420 		if apex_name == what {
421 			return true
422 		}
423 		// //apex_available:anyapex matches with any apex name, but not //apex_available:platform
424 		if apex_name == AvailableToAnyApex && what != AvailableToPlatform {
425 			return true
426 		}
427 		// prefix match.
428 		if strings.HasSuffix(apex_name, ".*") && strings.HasPrefix(what, strings.TrimSuffix(apex_name, "*")) {
429 			return true
430 		}
431 	}
432 	return false
433 }
434 
435 // Implements ApexModule
436 func (m *ApexModuleBase) AvailableFor(what string) bool {
437 	return CheckAvailableForApex(what, m.ApexProperties.Apex_available)
438 }
439 
440 // Implements ApexModule
441 func (m *ApexModuleBase) AlwaysRequiresPlatformApexVariant() bool {
442 	return false
443 }
444 
445 // Implements ApexModule
446 func (m *ApexModuleBase) NotAvailableForPlatform() bool {
447 	return m.ApexProperties.NotAvailableForPlatform
448 }
449 
450 // Implements ApexModule
451 func (m *ApexModuleBase) SetNotAvailableForPlatform() {
452 	m.ApexProperties.NotAvailableForPlatform = true
453 }
454 
455 // This function makes sure that the apex_available property is valid
456 func (m *ApexModuleBase) checkApexAvailableProperty(mctx BaseModuleContext) {
457 	for _, n := range m.ApexProperties.Apex_available {
458 		if n == AvailableToPlatform || n == AvailableToAnyApex {
459 			continue
460 		}
461 		// Prefix pattern should end with .* and has at least two components.
462 		if strings.Contains(n, "*") {
463 			if !strings.HasSuffix(n, ".*") {
464 				mctx.PropertyErrorf("apex_available", "Wildcard should end with .* like com.foo.*")
465 			}
466 			if strings.Count(n, ".") < 2 {
467 				mctx.PropertyErrorf("apex_available", "Wildcard requires two or more components like com.foo.*")
468 			}
469 			if strings.Count(n, "*") != 1 {
470 				mctx.PropertyErrorf("apex_available", "Wildcard is not allowed in the middle.")
471 			}
472 			continue
473 		}
474 		if !mctx.OtherModuleExists(n) && !mctx.Config().AllowMissingDependencies() {
475 			mctx.PropertyErrorf("apex_available", "%q is not a valid module name", n)
476 		}
477 	}
478 }
479 
480 // AvailableToSameApexes returns true if the two modules are apex_available to
481 // exactly the same set of APEXes (and platform), i.e. if their apex_available
482 // properties have the same elements.
483 func AvailableToSameApexes(mod1, mod2 ApexModule) bool {
484 	mod1ApexAvail := SortedUniqueStrings(mod1.apexModuleBase().ApexProperties.Apex_available)
485 	mod2ApexAvail := SortedUniqueStrings(mod2.apexModuleBase().ApexProperties.Apex_available)
486 	if len(mod1ApexAvail) != len(mod2ApexAvail) {
487 		return false
488 	}
489 	for i, v := range mod1ApexAvail {
490 		if v != mod2ApexAvail[i] {
491 			return false
492 		}
493 	}
494 	return true
495 }
496 
497 // mergeApexVariations deduplicates apex variations that would build identically into a common
498 // variation. It returns the reduced list of variations and a list of aliases from the original
499 // variation names to the new variation names.
500 func mergeApexVariations(apexInfos []ApexInfo) (merged []ApexInfo, aliases [][2]string) {
501 	seen := make(map[string]int)
502 	for _, apexInfo := range apexInfos {
503 		// If this is for a prebuilt apex then use the actual name of the apex variation to prevent this
504 		// from being merged with other ApexInfo. See Prebuilt.ApexInfoMutator for more information.
505 		if apexInfo.ForPrebuiltApex {
506 			merged = append(merged, apexInfo)
507 			continue
508 		}
509 
510 		// Merge the ApexInfo together. If a compatible ApexInfo exists then merge the information from
511 		// this one into it, otherwise create a new merged ApexInfo from this one and save it away so
512 		// other ApexInfo instances can be merged into it.
513 		variantName := apexInfo.ApexVariationName
514 		mergedName := apexInfo.mergedName()
515 		if index, exists := seen[mergedName]; exists {
516 			// Variants having the same mergedName are deduped
517 			merged[index].InApexVariants = append(merged[index].InApexVariants, variantName)
518 			merged[index].Updatable = merged[index].Updatable || apexInfo.Updatable
519 			// Platform APIs is allowed for this module only when all APEXes containing
520 			// the module are with `use_platform_apis: true`.
521 			merged[index].UsePlatformApis = merged[index].UsePlatformApis && apexInfo.UsePlatformApis
522 			merged[index].TestApexes = append(merged[index].TestApexes, apexInfo.TestApexes...)
523 		} else {
524 			seen[mergedName] = len(merged)
525 			apexInfo.ApexVariationName = mergedName
526 			apexInfo.InApexVariants = CopyOf(apexInfo.InApexVariants)
527 			apexInfo.TestApexes = CopyOf(apexInfo.TestApexes)
528 			merged = append(merged, apexInfo)
529 		}
530 		aliases = append(aliases, [2]string{variantName, mergedName})
531 	}
532 	return merged, aliases
533 }
534 
535 // IncomingApexTransition is called by apexTransitionMutator.IncomingTransition on modules that can be in apexes.
536 // The incomingVariation can be either the name of an apex if the dependency is coming directly from an apex
537 // module, or it can be the name of an apex variation (e.g. apex10000) if it is coming from another module that
538 // is in the apex.
539 func IncomingApexTransition(ctx IncomingTransitionContext, incomingVariation string) string {
540 	module := ctx.Module().(ApexModule)
541 	base := module.apexModuleBase()
542 
543 	var apexInfos []ApexInfo
544 	if allApexInfos, ok := ModuleProvider(ctx, AllApexInfoProvider); ok {
545 		apexInfos = allApexInfos.ApexInfos
546 	}
547 
548 	// Dependencies from platform variations go to the platform variation.
549 	if incomingVariation == "" {
550 		return ""
551 	}
552 
553 	if len(apexInfos) == 0 {
554 		if ctx.IsAddingDependency() {
555 			// If this module has no apex variations we can't do any mapping on the incoming variation, just return it
556 			// and let the caller get a "missing variant" error.
557 			return incomingVariation
558 		} else {
559 			// If this module has no apex variations the use the platform variation.
560 			return ""
561 		}
562 	}
563 
564 	// Convert the list of apex infos into from the AllApexInfoProvider into the merged list
565 	// of apex variations and the aliases from apex names to apex variations.
566 	var aliases [][2]string
567 	if !module.UniqueApexVariations() && !base.ApexProperties.UniqueApexVariationsForDeps {
568 		apexInfos, aliases = mergeApexVariations(apexInfos)
569 	}
570 
571 	// Check if the incoming variation matches an apex name, and if so use the corresponding
572 	// apex variation.
573 	aliasIndex := slices.IndexFunc(aliases, func(alias [2]string) bool {
574 		return alias[0] == incomingVariation
575 	})
576 	if aliasIndex >= 0 {
577 		return aliases[aliasIndex][1]
578 	}
579 
580 	// Check if the incoming variation matches an apex variation.
581 	apexIndex := slices.IndexFunc(apexInfos, func(info ApexInfo) bool {
582 		return info.ApexVariationName == incomingVariation
583 	})
584 	if apexIndex >= 0 {
585 		return incomingVariation
586 	}
587 
588 	return ""
589 }
590 
591 func MutateApexTransition(ctx BaseModuleContext, variation string) {
592 	module := ctx.Module().(ApexModule)
593 	base := module.apexModuleBase()
594 	platformVariation := variation == ""
595 
596 	var apexInfos []ApexInfo
597 	if allApexInfos, ok := ModuleProvider(ctx, AllApexInfoProvider); ok {
598 		apexInfos = allApexInfos.ApexInfos
599 	}
600 
601 	// Shortcut
602 	if len(apexInfos) == 0 {
603 		return
604 	}
605 
606 	// Do some validity checks.
607 	// TODO(jiyong): is this the right place?
608 	base.checkApexAvailableProperty(ctx)
609 
610 	if !module.UniqueApexVariations() && !base.ApexProperties.UniqueApexVariationsForDeps {
611 		apexInfos, _ = mergeApexVariations(apexInfos)
612 	}
613 
614 	if platformVariation && !ctx.Host() && !module.AvailableFor(AvailableToPlatform) && module.NotAvailableForPlatform() {
615 		// Do not install the module for platform, but still allow it to output
616 		// uninstallable AndroidMk entries in certain cases when they have side
617 		// effects.  TODO(jiyong): move this routine to somewhere else
618 		module.MakeUninstallable()
619 	}
620 	if !platformVariation {
621 		var thisApexInfo ApexInfo
622 
623 		apexIndex := slices.IndexFunc(apexInfos, func(info ApexInfo) bool {
624 			return info.ApexVariationName == variation
625 		})
626 		if apexIndex >= 0 {
627 			thisApexInfo = apexInfos[apexIndex]
628 		} else {
629 			panic(fmt.Errorf("failed to find apexInfo for incoming variation %q", variation))
630 		}
631 
632 		SetProvider(ctx, ApexInfoProvider, thisApexInfo)
633 	}
634 
635 	// Set the value of TestApexes in every single apex variant.
636 	// This allows each apex variant to be aware of the test apexes in the user provided apex_available.
637 	var testApexes []string
638 	for _, a := range apexInfos {
639 		testApexes = append(testApexes, a.TestApexes...)
640 	}
641 	base.ApexProperties.TestApexes = testApexes
642 
643 }
644 
645 func ApexInfoMutator(ctx TopDownMutatorContext, module ApexModule) {
646 	base := module.apexModuleBase()
647 	if len(base.apexInfos) > 0 {
648 		apexInfos := slices.Clone(base.apexInfos)
649 		slices.SortFunc(apexInfos, func(a, b ApexInfo) int {
650 			return strings.Compare(a.ApexVariationName, b.ApexVariationName)
651 		})
652 		SetProvider(ctx, AllApexInfoProvider, &AllApexInfo{apexInfos})
653 		// base.apexInfos is only needed to propagate the list of apexes from the apex module to its
654 		// contents within apexInfoMutator. Clear it so it doesn't accidentally get used later.
655 		base.apexInfos = nil
656 	}
657 }
658 
659 // UpdateUniqueApexVariationsForDeps sets UniqueApexVariationsForDeps if any dependencies that are
660 // in the same APEX have unique APEX variations so that the module can link against the right
661 // variant.
662 func UpdateUniqueApexVariationsForDeps(mctx BottomUpMutatorContext, am ApexModule) {
663 	// anyInSameApex returns true if the two ApexInfo lists contain any values in an
664 	// InApexVariants list in common. It is used instead of DepIsInSameApex because it needs to
665 	// determine if the dep is in the same APEX due to being directly included, not only if it
666 	// is included _because_ it is a dependency.
667 	anyInSameApex := func(a, b ApexModule) bool {
668 		collectApexes := func(m ApexModule) []string {
669 			if allApexInfo, ok := OtherModuleProvider(mctx, m, AllApexInfoProvider); ok {
670 				var ret []string
671 				for _, info := range allApexInfo.ApexInfos {
672 					ret = append(ret, info.InApexVariants...)
673 				}
674 				return ret
675 			}
676 			return nil
677 		}
678 
679 		aApexes := collectApexes(a)
680 		bApexes := collectApexes(b)
681 		sort.Strings(bApexes)
682 		for _, aApex := range aApexes {
683 			index := sort.SearchStrings(bApexes, aApex)
684 			if index < len(bApexes) && bApexes[index] == aApex {
685 				return true
686 			}
687 		}
688 		return false
689 	}
690 
691 	// If any of the dependencies requires unique apex variations, so does this module.
692 	mctx.VisitDirectDeps(func(dep Module) {
693 		if depApexModule, ok := dep.(ApexModule); ok {
694 			if anyInSameApex(depApexModule, am) &&
695 				(depApexModule.UniqueApexVariations() ||
696 					depApexModule.apexModuleBase().ApexProperties.UniqueApexVariationsForDeps) {
697 				am.apexModuleBase().ApexProperties.UniqueApexVariationsForDeps = true
698 			}
699 		}
700 	})
701 }
702 
703 ////////////////////////////////////////////////////////////////////////////////////////////////////
704 //Below are routines for extra safety checks.
705 //
706 // BuildDepsInfoLists is to flatten the dependency graph for an apexBundle into a text file
707 // (actually two in slightly different formats). The files are mostly for debugging, for example to
708 // see why a certain module is included in an APEX via which dependency path.
709 //
710 // CheckMinSdkVersion is to make sure that all modules in an apexBundle satisfy the min_sdk_version
711 // requirement of the apexBundle.
712 
713 // A dependency info for a single ApexModule, either direct or transitive.
714 type ApexModuleDepInfo struct {
715 	// Name of the dependency
716 	To string
717 	// List of dependencies To belongs to. Includes APEX itself, if a direct dependency.
718 	From []string
719 	// Whether the dependency belongs to the final compiled APEX.
720 	IsExternal bool
721 	// min_sdk_version of the ApexModule
722 	MinSdkVersion string
723 }
724 
725 // A map of a dependency name to its ApexModuleDepInfo
726 type DepNameToDepInfoMap map[string]ApexModuleDepInfo
727 
728 type ApexBundleDepsInfo struct {
729 	flatListPath Path
730 	fullListPath Path
731 }
732 
733 type ApexBundleDepsInfoIntf interface {
734 	Updatable() bool
735 	FlatListPath() Path
736 	FullListPath() Path
737 }
738 
739 func (d *ApexBundleDepsInfo) FlatListPath() Path {
740 	return d.flatListPath
741 }
742 
743 func (d *ApexBundleDepsInfo) FullListPath() Path {
744 	return d.fullListPath
745 }
746 
747 // Generate two module out files:
748 // 1. FullList with transitive deps and their parents in the dep graph
749 // 2. FlatList with a flat list of transitive deps
750 // In both cases transitive deps of external deps are not included. Neither are deps that are only
751 // available to APEXes; they are developed with updatability in mind and don't need manual approval.
752 func (d *ApexBundleDepsInfo) BuildDepsInfoLists(ctx ModuleContext, minSdkVersion string, depInfos DepNameToDepInfoMap) {
753 	var fullContent strings.Builder
754 	var flatContent strings.Builder
755 
756 	fmt.Fprintf(&fullContent, "%s(minSdkVersion:%s):\n", ctx.ModuleName(), minSdkVersion)
757 	for _, key := range FirstUniqueStrings(SortedKeys(depInfos)) {
758 		info := depInfos[key]
759 		toName := fmt.Sprintf("%s(minSdkVersion:%s)", info.To, info.MinSdkVersion)
760 		if info.IsExternal {
761 			toName = toName + " (external)"
762 		}
763 		fmt.Fprintf(&fullContent, "  %s <- %s\n", toName, strings.Join(SortedUniqueStrings(info.From), ", "))
764 		fmt.Fprintf(&flatContent, "%s\n", toName)
765 	}
766 
767 	fullListPath := PathForModuleOut(ctx, "depsinfo", "fulllist.txt")
768 	WriteFileRule(ctx, fullListPath, fullContent.String())
769 	d.fullListPath = fullListPath
770 
771 	flatListPath := PathForModuleOut(ctx, "depsinfo", "flatlist.txt")
772 	WriteFileRule(ctx, flatListPath, flatContent.String())
773 	d.flatListPath = flatListPath
774 
775 	ctx.Phony(fmt.Sprintf("%s-depsinfo", ctx.ModuleName()), fullListPath, flatListPath)
776 }
777 
778 // Function called while walking an APEX's payload dependencies.
779 //
780 // Return true if the `to` module should be visited, false otherwise.
781 type PayloadDepsCallback func(ctx BaseModuleContext, from blueprint.Module, to ApexModule, externalDep bool) bool
782 type WalkPayloadDepsFunc func(ctx BaseModuleContext, do PayloadDepsCallback)
783 
784 // ModuleWithMinSdkVersionCheck represents a module that implements min_sdk_version checks
785 type ModuleWithMinSdkVersionCheck interface {
786 	Module
787 	MinSdkVersion(ctx EarlyModuleContext) ApiLevel
788 	CheckMinSdkVersion(ctx ModuleContext)
789 }
790 
791 // CheckMinSdkVersion checks if every dependency of an updatable module sets min_sdk_version
792 // accordingly
793 func CheckMinSdkVersion(ctx ModuleContext, minSdkVersion ApiLevel, walk WalkPayloadDepsFunc) {
794 	// do not enforce min_sdk_version for host
795 	if ctx.Host() {
796 		return
797 	}
798 
799 	// do not enforce for coverage build
800 	if ctx.Config().IsEnvTrue("EMMA_INSTRUMENT") || ctx.DeviceConfig().NativeCoverageEnabled() || ctx.DeviceConfig().ClangCoverageEnabled() {
801 		return
802 	}
803 
804 	// do not enforce deps.min_sdk_version if APEX/APK doesn't set min_sdk_version
805 	if minSdkVersion.IsNone() {
806 		return
807 	}
808 
809 	walk(ctx, func(ctx BaseModuleContext, from blueprint.Module, to ApexModule, externalDep bool) bool {
810 		if externalDep {
811 			// external deps are outside the payload boundary, which is "stable"
812 			// interface. We don't have to check min_sdk_version for external
813 			// dependencies.
814 			return false
815 		}
816 		if am, ok := from.(DepIsInSameApex); ok && !am.DepIsInSameApex(ctx, to) {
817 			return false
818 		}
819 		if m, ok := to.(ModuleWithMinSdkVersionCheck); ok {
820 			// This dependency performs its own min_sdk_version check, just make sure it sets min_sdk_version
821 			// to trigger the check.
822 			if !m.MinSdkVersion(ctx).Specified() {
823 				ctx.OtherModuleErrorf(m, "must set min_sdk_version")
824 			}
825 			return false
826 		}
827 		if err := to.ShouldSupportSdkVersion(ctx, minSdkVersion); err != nil {
828 			toName := ctx.OtherModuleName(to)
829 			ctx.OtherModuleErrorf(to, "should support min_sdk_version(%v) for %q: %v."+
830 				"\n\nDependency path: %s\n\n"+
831 				"Consider adding 'min_sdk_version: %q' to %q",
832 				minSdkVersion, ctx.ModuleName(), err.Error(),
833 				ctx.GetPathString(false),
834 				minSdkVersion, toName)
835 			return false
836 		}
837 		return true
838 	})
839 }
840 
841 // Construct ApiLevel object from min_sdk_version string value
842 func MinSdkVersionFromValue(ctx EarlyModuleContext, value string) ApiLevel {
843 	if value == "" {
844 		return NoneApiLevel
845 	}
846 	apiLevel, err := ApiLevelFromUser(ctx, value)
847 	if err != nil {
848 		ctx.PropertyErrorf("min_sdk_version", "%s", err.Error())
849 		return NoneApiLevel
850 	}
851 	return apiLevel
852 }
853 
854 var ApexExportsInfoProvider = blueprint.NewProvider[ApexExportsInfo]()
855 
856 // ApexExportsInfo contains information about the artifacts provided by apexes to dexpreopt and hiddenapi
857 type ApexExportsInfo struct {
858 	// Canonical name of this APEX. Used to determine the path to the activated APEX on
859 	// device (/apex/<apex_name>)
860 	ApexName string
861 
862 	// Path to the image profile file on host (or empty, if profile is not generated).
863 	ProfilePathOnHost Path
864 
865 	// Map from the apex library name (without prebuilt_ prefix) to the dex file path on host
866 	LibraryNameToDexJarPathOnHost map[string]Path
867 }
868 
869 var PrebuiltInfoProvider = blueprint.NewProvider[PrebuiltInfo]()
870 
871 // contents of prebuilt_info.json
872 type PrebuiltInfo struct {
873 	// Name of the apex, without the prebuilt_ prefix
874 	Name string
875 
876 	Is_prebuilt bool
877 
878 	// This is relative to root of the workspace.
879 	// In case of mainline modules, this file contains the build_id that was used
880 	// to generate the mainline module prebuilt.
881 	Prebuilt_info_file_path string `json:",omitempty"`
882 }
883