Handle installation rules for co-existing prebuilts

Every module belonging to a single mainline module family will be
hidden from make, except the one which has been flagged using
apex_contributions

Details
- Introduce a new `source_apex_name` property to prebuilt_apex and
  override_apex. This property will be used to identify the source
  equivalent of a prebuilt soong apex module.
- Create an N-ary tree from source to prebuilt(s). The tree wil be
  rooted at the source module.
- In a subsequent mutator, visit every node in the tree(s). Query
  apex_contributions and store the handle of the node which is "active"
  (if any)
- In the same mutator, do another pass over the tree. Invoke
  `HideFromMake` on every node which is not "active". The two-pass
  approach is needed PrebuiltSelectionInfoProvider does not know about
  the inter source-prebuilt dependency, this dependency can only be
  known by doing a graph walk of the N-ary tree.

Some tangential implementation details
- Each prebuilt apex has an internal deapxer module that is responsible
  for generating the deapex ninja rules. The name of this internal
  module uses the BaseModuleName (without the prebuilt_ prefix). Since
  we can have multiple prebuilt soong modules in trunk stable, change
  this to follow the name of the prebuilt module in order to avoid name
  collisions. Update existing unit tests accordingly

Bug: 316179314
Test: go test ./apex -run TestInstallationRulesForMultipleApexPrebuilts
Test: m nothing --no-skip-soong-tests
Test: presubmits

Change-Id: I58aa99d5e6a9859954614e6db9a8e9e2e581642d

1 files changed, 18 insertions, 11 deletions

diff --git a/apex/prebuilt.go b/apex/prebuilt.go
index 188875ac9..9db3b7a9d 100644
--- a/apex/prebuilt.go
+++ b/apex/prebuilt.go
@@ -87,6 +87,12 @@ type PrebuiltCommonProperties struct {
 	// device (/apex/<apex_name>). If unspecified, follows the name property.
 	Apex_name *string
 
+	// Name of the source APEX that gets shadowed by this prebuilt
+	// e.g. com.mycompany.android.myapex
+	// If unspecified, follows the naming convention that the source apex of
+	// the prebuilt is Name() without "prebuilt_" prefix
+	Source_apex_name *string
+
 	ForceDisable bool `blueprint:"mutated"`
 
 	// whether the extracted apex file is installable.
@@ -126,7 +132,11 @@ func (p *prebuiltCommon) initPrebuiltCommon(module android.Module, properties *P
 }
 
 func (p *prebuiltCommon) ApexVariationName() string {
-	return proptools.StringDefault(p.prebuiltCommonProperties.Apex_name, p.ModuleBase.BaseModuleName())
+	return proptools.StringDefault(p.prebuiltCommonProperties.Apex_name, p.BaseModuleName())
+}
+
+func (p *prebuiltCommon) BaseModuleName() string {
+	return proptools.StringDefault(p.prebuiltCommonProperties.Source_apex_name, p.ModuleBase.BaseModuleName())
 }
 
 func (p *prebuiltCommon) Prebuilt() *android.Prebuilt {
@@ -226,6 +236,7 @@ func (p *prebuiltCommon) AndroidMkEntries() []android.AndroidMkEntries {
 			OutputFile:    android.OptionalPathForPath(p.outputApex),
 			Include:       "$(BUILD_PREBUILT)",
 			Host_required: p.hostRequired,
+			OverrideName:  p.BaseModuleName(),
 			ExtraEntries: []android.AndroidMkExtraEntriesFunc{
 				func(ctx android.AndroidMkExtraEntriesContext, entries *android.AndroidMkEntries) {
 					entries.SetString("LOCAL_MODULE_PATH", p.installDir.String())
@@ -436,7 +447,7 @@ func (p *prebuiltCommon) apexInfoMutator(mctx android.TopDownMutatorContext) {
 	apexInfo := android.ApexInfo{
 		ApexVariationName: apexVariationName,
 		InApexVariants:    []string{apexVariationName},
-		InApexModules:     []string{p.ModuleBase.BaseModuleName()}, // BaseModuleName() to avoid the prebuilt_ prefix.
+		InApexModules:     []string{p.BaseModuleName()}, // BaseModuleName() to avoid the prebuilt_ prefix.
 		ApexContents:      []*android.ApexContents{apexContents},
 		ForPrebuiltApex:   true,
 	}
@@ -739,13 +750,11 @@ var _ prebuiltApexModuleCreator = (*Prebuilt)(nil)
 //     V            V            V
 //     selector  <---  deapexer  <---  exported java lib
 func (p *Prebuilt) createPrebuiltApexModules(ctx android.TopDownMutatorContext) {
-	baseModuleName := p.BaseModuleName()
-
-	apexSelectorModuleName := apexSelectorModuleName(baseModuleName)
+	apexSelectorModuleName := apexSelectorModuleName(p.Name())
 	createApexSelectorModule(ctx, apexSelectorModuleName, &p.properties.ApexFileProperties)
 
 	apexFileSource := ":" + apexSelectorModuleName
-	p.createDeapexerModuleIfNeeded(ctx, deapexerModuleName(baseModuleName), apexFileSource)
+	p.createDeapexerModuleIfNeeded(ctx, deapexerModuleName(p.Name()), apexFileSource)
 
 	// Add a source reference to retrieve the selected apex from the selector module.
 	p.prebuiltCommonProperties.Selected_apex = proptools.StringPtr(apexFileSource)
@@ -759,7 +768,7 @@ func (p *prebuiltCommon) DepsMutator(ctx android.BottomUpMutatorContext) {
 	if p.hasExportedDeps() {
 		// Create a dependency from the prebuilt apex (prebuilt_apex/apex_set) to the internal deapexer module
 		// The deapexer will return a provider that will be bubbled up to the rdeps of apexes (e.g. dex_bootjars)
-		ctx.AddDependency(ctx.Module(), android.DeapexerTag, deapexerModuleName(p.BaseModuleName()))
+		ctx.AddDependency(ctx.Module(), android.DeapexerTag, deapexerModuleName(p.Name()))
 	}
 }
 
@@ -997,13 +1006,11 @@ var _ prebuiltApexModuleCreator = (*ApexSet)(nil)
 // from those provided this creates an extractor module which extracts the appropriate .apex file
 // from the zip file containing them.
 func (a *ApexSet) createPrebuiltApexModules(ctx android.TopDownMutatorContext) {
-	baseModuleName := a.BaseModuleName()
-
-	apexExtractorModuleName := apexExtractorModuleName(baseModuleName)
+	apexExtractorModuleName := apexExtractorModuleName(a.Name())
 	createApexExtractorModule(ctx, apexExtractorModuleName, &a.properties.ApexExtractorProperties)
 
 	apexFileSource := ":" + apexExtractorModuleName
-	a.createDeapexerModuleIfNeeded(ctx, deapexerModuleName(baseModuleName), apexFileSource)
+	a.createDeapexerModuleIfNeeded(ctx, deapexerModuleName(a.Name()), apexFileSource)
 
 	// After passing the arch specific src properties to the creating the apex selector module
 	a.prebuiltCommonProperties.Selected_apex = proptools.StringPtr(apexFileSource)