Export dex implementation jars from prebuilt_apex
Dexpreopt and boot jars package check all require access to dex
implementation jars created for java_library and java_sdk_library. They
were available when building from source but not when building from
prebuilts, even though they are embedded within the .apex files that
are referenced from prebuilt_apex.
This changes adds support to prebuilt_apex to export the dex
implementation jars and updates java_import to use those exported dex
implementation jars.
In a source build dexpreopt/boot jars package check access the apex (or
platform) specific variant of a java_library, e.g. core-oj, from which
it retrieves the dex implementation jar path.
After this change in a prebuilt build dexpreopt/boot jars package check
behave in the same way except in this case they retrieve the dex
implementation jar path from the apex (or platform) specific variant of
the java_import, e.g. core-oj.
The work to export files from a `.apex` file for use by other modules
is performed by a new `deapexer` module type. It is not used directly
in an `Android.bp` file but instead is created implicitly by
`prebuilt_apex`,
In order to do that this contains the following changes:
* Adds a new `dexapexer` module type to handle the exporting of files
from the `.apex` file.
* Adds an exported_java_libs property to prebuilt_apex to specify the
set of libraries whose dex implementation jars need exporting.
* Creates apex specific variants of the libraries listed in the
exported_java_libs property.
* Adds the set of exported files to the ApexInfo to make them available
to the apex specific variants.
* Prevents the prebuilt_apex variants from being merged together as
they will not be compatible.
* Modifies java_import to use the exported file for variants of a
prebuilt_apex.
* Adds a ninja rule to unpack (using deapexer) the contents of the
prebuilt_apex's apex file, verify that the required files are present
and make them available as outputs for other rules to use.
* Some minor refactorings to support these changes.
* Adds tests to cover prebuilt only, prebuilt with source preferred,
and prebuilt preferred with source.
Test: m nothing
Bug: 171061220
Change-Id: Ic9bed81fb65b92f0d59f64c0bce168a9ed44cfac
diff --git a/apex/prebuilt.go b/apex/prebuilt.go
index 50e892e..c72a9eb 100644
--- a/apex/prebuilt.go
+++ b/apex/prebuilt.go
@@ -158,6 +158,7 @@
type PrebuiltProperties struct {
ApexFileProperties
+ DeapexerProperties
Installable *bool
// Optional name for the installed apex. If unspecified, name of the
@@ -198,19 +199,152 @@
}
// prebuilt_apex imports an `.apex` file into the build graph as if it was built with apex.
+//
+// If this needs to make files from within a `.apex` file available for use by other Soong modules,
+// e.g. make dex implementation jars available for java_import modules isted in exported_java_libs,
+// it does so as follows:
+//
+// 1. It creates a `deapexer` module that actually extracts the files from the `.apex` file and
+// makes them available for use by other modules, at both Soong and ninja levels.
+//
+// 2. It adds a dependency onto those modules and creates an apex specific variant similar to what
+// an `apex` module does. That ensures that code which looks for specific apex variant, e.g.
+// dexpreopt, will work the same way from source and prebuilt.
+//
+// 3. The `deapexer` module adds a dependency from the modules that require the exported files onto
+// itself so that they can retrieve the file paths to those files.
+//
func PrebuiltFactory() android.Module {
module := &Prebuilt{}
module.AddProperties(&module.properties)
android.InitSingleSourcePrebuiltModule(module, &module.properties, "Source")
android.InitAndroidMultiTargetsArchModule(module, android.DeviceSupported, android.MultilibCommon)
+
+ android.AddLoadHook(module, func(ctx android.LoadHookContext) {
+ props := struct {
+ Name *string
+ }{
+ Name: proptools.StringPtr(module.BaseModuleName() + ".deapexer"),
+ }
+ ctx.CreateModule(privateDeapexerFactory,
+ &props,
+ &module.properties.ApexFileProperties,
+ &module.properties.DeapexerProperties,
+ )
+ })
+
return module
}
+func prebuiltApexExportedModuleName(ctx android.BottomUpMutatorContext, name string) string {
+ // The prebuilt_apex should be depending on prebuilt modules but as this runs after
+ // prebuilt_rename the prebuilt module may or may not be using the prebuilt_ prefixed named. So,
+ // check to see if the prefixed name is in use first, if it is then use that, otherwise assume
+ // the unprefixed name is the one to use. If the unprefixed one turns out to be a source module
+ // and not a renamed prebuilt module then that will be detected and reported as an error when
+ // processing the dependency in ApexInfoMutator().
+ prebuiltName := "prebuilt_" + name
+ if ctx.OtherModuleExists(prebuiltName) {
+ name = prebuiltName
+ }
+ return name
+}
+
func (p *Prebuilt) DepsMutator(ctx android.BottomUpMutatorContext) {
if err := p.properties.selectSource(ctx); err != nil {
ctx.ModuleErrorf("%s", err)
return
}
+
+ // Add dependencies onto the java modules that represent the java libraries that are provided by
+ // and exported from this prebuilt apex.
+ for _, lib := range p.properties.Exported_java_libs {
+ dep := prebuiltApexExportedModuleName(ctx, lib)
+ ctx.AddFarVariationDependencies(ctx.Config().AndroidCommonTarget.Variations(), javaLibTag, dep)
+ }
+}
+
+var _ ApexInfoMutator = (*Prebuilt)(nil)
+
+// ApexInfoMutator marks any modules for which this apex exports a file as requiring an apex
+// specific variant and checks that they are supported.
+//
+// The apexMutator will ensure that the ApexInfo objects passed to BuildForApex(ApexInfo) are
+// associated with the apex specific variant using the ApexInfoProvider for later retrieval.
+//
+// Unlike the source apex module type the prebuilt_apex module type cannot share compatible variants
+// across prebuilt_apex modules. That is because there is no way to determine whether two
+// prebuilt_apex modules that export files for the same module are compatible. e.g. they could have
+// been built from different source at different times or they could have been built with different
+// build options that affect the libraries.
+//
+// While it may be possible to provide sufficient information to determine whether two prebuilt_apex
+// modules were compatible it would be a lot of work and would not provide much benefit for a couple
+// of reasons:
+// * The number of prebuilt_apex modules that will be exporting files for the same module will be
+// low as the prebuilt_apex only exports files for the direct dependencies that require it and
+// very few modules are direct dependencies of multiple prebuilt_apex modules, e.g. there are a
+// few com.android.art* apex files that contain the same contents and could export files for the
+// same modules but only one of them needs to do so. Contrast that with source apex modules which
+// need apex specific variants for every module that contributes code to the apex, whether direct
+// or indirect.
+// * The build cost of a prebuilt_apex variant is generally low as at worst it will involve some
+// extra copying of files. Contrast that with source apex modules that has to build each variant
+// from source.
+func (p *Prebuilt) ApexInfoMutator(mctx android.TopDownMutatorContext) {
+
+ // Collect direct dependencies into contents.
+ contents := make(map[string]android.ApexMembership)
+
+ // Collect the list of dependencies.
+ var dependencies []android.ApexModule
+ mctx.VisitDirectDeps(func(m android.Module) {
+ tag := mctx.OtherModuleDependencyTag(m)
+ if tag == javaLibTag {
+ depName := mctx.OtherModuleName(m)
+
+ // It is an error if the other module is not a prebuilt.
+ if _, ok := m.(android.PrebuiltInterface); !ok {
+ mctx.PropertyErrorf("exported_java_libs", "%q is not a prebuilt module", depName)
+ return
+ }
+
+ // It is an error if the other module is not an ApexModule.
+ if _, ok := m.(android.ApexModule); !ok {
+ mctx.PropertyErrorf("exported_java_libs", "%q is not usable within an apex", depName)
+ return
+ }
+
+ // Strip off the prebuilt_ prefix if present before storing content to ensure consistent
+ // behavior whether there is a corresponding source module present or not.
+ depName = android.RemoveOptionalPrebuiltPrefix(depName)
+
+ // Remember that this module was added as a direct dependency.
+ contents[depName] = contents[depName].Add(true)
+
+ // Add the module to the list of dependencies that need to have an APEX variant.
+ dependencies = append(dependencies, m.(android.ApexModule))
+ }
+ })
+
+ // Create contents for the prebuilt_apex and store it away for later use.
+ apexContents := android.NewApexContents(contents)
+ mctx.SetProvider(ApexBundleInfoProvider, ApexBundleInfo{
+ Contents: apexContents,
+ })
+
+ // Create an ApexInfo for the prebuilt_apex.
+ apexInfo := android.ApexInfo{
+ ApexVariationName: mctx.ModuleName(),
+ InApexes: []string{mctx.ModuleName()},
+ ApexContents: []*android.ApexContents{apexContents},
+ ForPrebuiltApex: true,
+ }
+
+ // Mark the dependencies of this module as requiring a variant for this module.
+ for _, am := range dependencies {
+ am.BuildForApex(apexInfo)
+ }
}
func (p *Prebuilt) GenerateAndroidBuildActions(ctx android.ModuleContext) {