1// Copyright 2021 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 java
16
17import (
18	"android/soong/android"
19
20	"github.com/google/blueprint"
21	"github.com/google/blueprint/proptools"
22)
23
24// Contains code that is common to both platform_bootclasspath and bootclasspath_fragment.
25
26func init() {
27	registerBootclasspathBuildComponents(android.InitRegistrationContext)
28}
29
30func registerBootclasspathBuildComponents(ctx android.RegistrationContext) {
31	ctx.FinalDepsMutators(func(ctx android.RegisterMutatorsContext) {
32		ctx.BottomUp("bootclasspath_deps", bootclasspathDepsMutator).Parallel()
33	})
34}
35
36// BootclasspathDepsMutator is the interface that a module must implement if it wants to add
37// dependencies onto APEX specific variants of bootclasspath fragments or bootclasspath contents.
38type BootclasspathDepsMutator interface {
39	// BootclasspathDepsMutator implementations should add dependencies using
40	// addDependencyOntoApexModulePair and addDependencyOntoApexVariants.
41	BootclasspathDepsMutator(ctx android.BottomUpMutatorContext)
42}
43
44// bootclasspathDepsMutator is called during the final deps phase after all APEX variants have
45// been created so can add dependencies onto specific APEX variants of modules.
46func bootclasspathDepsMutator(ctx android.BottomUpMutatorContext) {
47	m := ctx.Module()
48	if p, ok := m.(BootclasspathDepsMutator); ok {
49		p.BootclasspathDepsMutator(ctx)
50	}
51}
52
53// addDependencyOntoApexVariants adds dependencies onto the appropriate apex specific variants of
54// the module as specified in the ApexVariantReference list.
55func addDependencyOntoApexVariants(ctx android.BottomUpMutatorContext, propertyName string, refs []ApexVariantReference, tag blueprint.DependencyTag) {
56	for i, ref := range refs {
57		apex := proptools.StringDefault(ref.Apex, "platform")
58
59		if ref.Module == nil {
60			ctx.PropertyErrorf(propertyName, "missing module name at position %d", i)
61			continue
62		}
63		name := proptools.String(ref.Module)
64
65		addDependencyOntoApexModulePair(ctx, apex, name, tag)
66	}
67}
68
69// addDependencyOntoApexModulePair adds a dependency onto the specified APEX specific variant or the
70// specified module.
71//
72// If apex="platform" or "system_ext" then this adds a dependency onto the platform variant of the
73// module. This adds dependencies onto the prebuilt and source modules with the specified name,
74// depending on which ones are available. Visiting must use isActiveModule to select the preferred
75// module when both source and prebuilt modules are available.
76//
77// Use gatherApexModulePairDepsWithTag to retrieve the dependencies.
78func addDependencyOntoApexModulePair(ctx android.BottomUpMutatorContext, apex string, name string, tag blueprint.DependencyTag) {
79	var variations []blueprint.Variation
80	if apex != "platform" && apex != "system_ext" {
81		// Pick the correct apex variant.
82		variations = []blueprint.Variation{
83			{Mutator: "apex", Variation: apex},
84		}
85	}
86
87	addedDep := false
88	if ctx.OtherModuleDependencyVariantExists(variations, name) {
89		ctx.AddFarVariationDependencies(variations, tag, name)
90		addedDep = true
91	}
92
93	// Add a dependency on the prebuilt module if it exists.
94	prebuiltName := android.PrebuiltNameFromSource(name)
95	if ctx.OtherModuleDependencyVariantExists(variations, prebuiltName) {
96		ctx.AddVariationDependencies(variations, tag, prebuiltName)
97		addedDep = true
98	} else if ctx.Config().AlwaysUsePrebuiltSdks() && len(variations) > 0 {
99		// TODO(b/179354495): Remove this code path once the Android build has been fully migrated to
100		//  use bootclasspath_fragment properly.
101		// Some prebuilt java_sdk_library modules do not yet have an APEX variations so try and add a
102		// dependency on the non-APEX variant.
103		if ctx.OtherModuleDependencyVariantExists(nil, prebuiltName) {
104			ctx.AddVariationDependencies(nil, tag, prebuiltName)
105			addedDep = true
106		}
107	}
108
109	// If no appropriate variant existing for this, so no dependency could be added, then it is an
110	// error, unless missing dependencies are allowed. The simplest way to handle that is to add a
111	// dependency that will not be satisfied and the default behavior will handle it.
112	if !addedDep {
113		// Add dependency on the unprefixed (i.e. source or renamed prebuilt) module which we know does
114		// not exist. The resulting error message will contain useful information about the available
115		// variants.
116		reportMissingVariationDependency(ctx, variations, name)
117
118		// Add dependency on the missing prefixed prebuilt variant too if a module with that name exists
119		// so that information about its available variants will be reported too.
120		if ctx.OtherModuleExists(prebuiltName) {
121			reportMissingVariationDependency(ctx, variations, prebuiltName)
122		}
123	}
124}
125
126// reportMissingVariationDependency intentionally adds a dependency on a missing variation in order
127// to generate an appropriate error message with information about the available variations.
128func reportMissingVariationDependency(ctx android.BottomUpMutatorContext, variations []blueprint.Variation, name string) {
129	ctx.AddFarVariationDependencies(variations, nil, name)
130}
131
132// gatherApexModulePairDepsWithTag returns the list of dependencies with the supplied tag that was
133// added by addDependencyOntoApexModulePair.
134func gatherApexModulePairDepsWithTag(ctx android.BaseModuleContext, tag blueprint.DependencyTag) []android.Module {
135	var modules []android.Module
136	ctx.VisitDirectDepsIf(isActiveModule, func(module android.Module) {
137		t := ctx.OtherModuleDependencyTag(module)
138		if t == tag {
139			modules = append(modules, module)
140		}
141	})
142	return modules
143}
144
145// ApexVariantReference specifies a particular apex variant of a module.
146type ApexVariantReference struct {
147	// The name of the module apex variant, i.e. the apex containing the module variant.
148	//
149	// If this is not specified then it defaults to "platform" which will cause a dependency to be
150	// added to the module's platform variant.
151	//
152	// A value of system_ext should be used for any module that will be part of the system_ext
153	// partition.
154	Apex *string
155
156	// The name of the module.
157	Module *string
158}
159
160// BootclasspathFragmentsDepsProperties contains properties related to dependencies onto fragments.
161type BootclasspathFragmentsDepsProperties struct {
162	// The names of the bootclasspath_fragment modules that form part of this module.
163	Fragments []ApexVariantReference
164}
165
166// addDependenciesOntoFragments adds dependencies to the fragments specified in this properties
167// structure.
168func (p *BootclasspathFragmentsDepsProperties) addDependenciesOntoFragments(ctx android.BottomUpMutatorContext) {
169	addDependencyOntoApexVariants(ctx, "fragments", p.Fragments, bootclasspathFragmentDepTag)
170}
171
172// bootclasspathDependencyTag defines dependencies from/to bootclasspath_fragment,
173// prebuilt_bootclasspath_fragment and platform_bootclasspath onto either source or prebuilt
174// modules.
175type bootclasspathDependencyTag struct {
176	blueprint.BaseDependencyTag
177
178	name string
179}
180
181func (t bootclasspathDependencyTag) ExcludeFromVisibilityEnforcement() {
182}
183
184// Dependencies that use the bootclasspathDependencyTag instances are only added after all the
185// visibility checking has been done so this has no functional effect. However, it does make it
186// clear that visibility is not being enforced on these tags.
187var _ android.ExcludeFromVisibilityEnforcementTag = bootclasspathDependencyTag{}
188
189// The tag used for dependencies onto bootclasspath_fragments.
190var bootclasspathFragmentDepTag = bootclasspathDependencyTag{name: "fragment"}
191
192// BootclasspathNestedAPIProperties defines properties related to the API provided by parts of the
193// bootclasspath that are nested within the main BootclasspathAPIProperties.
194type BootclasspathNestedAPIProperties struct {
195	// java_library or preferably, java_sdk_library modules providing stub classes that define the
196	// APIs provided by this bootclasspath_fragment.
197	Stub_libs []string
198}
199
200// BootclasspathAPIProperties defines properties for defining the API provided by parts of the
201// bootclasspath.
202type BootclasspathAPIProperties struct {
203	// Api properties provide information about the APIs provided by the bootclasspath_fragment.
204	// Properties in this section apply to public, system and test api scopes. They DO NOT apply to
205	// core_platform as that is a special, ART specific scope, that does not follow the pattern and so
206	// has its own section. It is in the process of being deprecated and replaced by the system scope
207	// but this will remain for the foreseeable future to maintain backwards compatibility.
208	//
209	// Every bootclasspath_fragment must specify at least one stubs_lib in this section and must
210	// specify stubs for all the APIs provided by its contents. Failure to do so will lead to those
211	// methods being inaccessible to other parts of Android, including but not limited to
212	// applications.
213	Api BootclasspathNestedAPIProperties
214
215	// Properties related to the core platform API surface.
216	//
217	// This must only be used by the following modules:
218	// * ART
219	// * Conscrypt
220	// * I18N
221	//
222	// The bootclasspath_fragments for each of the above modules must specify at least one stubs_lib
223	// and must specify stubs for all the APIs provided by its contents. Failure to do so will lead to
224	// those methods being inaccessible to the other modules in the list.
225	Core_platform_api BootclasspathNestedAPIProperties
226}
227
228// apiScopeToStubLibs calculates the stub library modules for each relevant *HiddenAPIScope from the
229// Stub_libs properties.
230func (p BootclasspathAPIProperties) apiScopeToStubLibs() map[*HiddenAPIScope][]string {
231	m := map[*HiddenAPIScope][]string{}
232	for _, apiScope := range hiddenAPISdkLibrarySupportedScopes {
233		m[apiScope] = p.Api.Stub_libs
234	}
235	m[CorePlatformHiddenAPIScope] = p.Core_platform_api.Stub_libs
236	return m
237}
238