Avoid passing around []hiddenAPIModule

Previously, an []android.Module was converted to an []hiddenAPIModule
that was then used to retrieve boot dex jars. That was ok when
obtaining the dex jar files from source modules for
bootclasspath_fragment but does not work well for other use cases as
it would require doing that conversion in multiple places.

This change pushes the use of hiddenAPIModule down to the methods that
retrieve information from it which makes the methods more flexible and
easier to reuse.

Bug: 177892522
Test: m nothing
Change-Id: Ib84aaf03d8f5a63b48232036fe4589646fc23352
Merged-In: Ib84aaf03d8f5a63b48232036fe4589646fc23352
(cherry picked from commit dd5993f6d41efa932c06afef71c40af446c85b4e)
diff --git a/java/bootclasspath_fragment.go b/java/bootclasspath_fragment.go
index 10d2fe2..fc8f557 100644
--- a/java/bootclasspath_fragment.go
+++ b/java/bootclasspath_fragment.go
@@ -140,7 +140,7 @@
 	// produceHiddenAPIAllFlagsFile produces the all-flags.csv and intermediate files.
 	//
 	// Updates the supplied hiddenAPIInfo with the paths to the generated files set.
-	produceHiddenAPIAllFlagsFile(ctx android.ModuleContext, contents []hiddenAPIModule, input HiddenAPIFlagInput) *HiddenAPIFlagOutput
+	produceHiddenAPIAllFlagsFile(ctx android.ModuleContext, contents []android.Module, input HiddenAPIFlagInput) *HiddenAPIFlagOutput
 }
 
 var _ commonBootclasspathFragment = (*BootclasspathFragmentModule)(nil)
@@ -465,7 +465,7 @@
 			if unencodedDex == nil {
 				// This is an error. Sometimes Soong will report the error directly, other times it will
 				// defer the error reporting to happen only when trying to use the missing file in ninja.
-				// Either way it is handled by extractBootDexJarsFromHiddenAPIModules which must have been
+				// Either way it is handled by extractBootDexJarsFromModules which must have been
 				// called before this as it generates the flags that are used to encode these files.
 				continue
 			}
@@ -561,12 +561,9 @@
 	// TODO(b/179354495): Stop hidden API processing being conditional once all bootclasspath_fragment
 	//  modules have been updated to support it.
 	if input.canPerformHiddenAPIProcessing(ctx, b.properties) {
-		// Get the content modules that contribute to the hidden API processing.
-		hiddenAPIModules := gatherHiddenAPIModuleFromContents(ctx, contents)
-
 		// Delegate the production of the hidden API all-flags.csv file to a module type specific method.
 		common := ctx.Module().(commonBootclasspathFragment)
-		output = common.produceHiddenAPIAllFlagsFile(ctx, hiddenAPIModules, input)
+		output = common.produceHiddenAPIAllFlagsFile(ctx, contents, input)
 	}
 
 	// Initialize a HiddenAPIInfo structure.
@@ -620,7 +617,7 @@
 
 // produceHiddenAPIAllFlagsFile produces the hidden API all-flags.csv file (and supporting files)
 // for the fragment.
-func (b *BootclasspathFragmentModule) produceHiddenAPIAllFlagsFile(ctx android.ModuleContext, contents []hiddenAPIModule, input HiddenAPIFlagInput) *HiddenAPIFlagOutput {
+func (b *BootclasspathFragmentModule) produceHiddenAPIAllFlagsFile(ctx android.ModuleContext, contents []android.Module, input HiddenAPIFlagInput) *HiddenAPIFlagOutput {
 	// Generate the rules to create the hidden API flags and update the supplied hiddenAPIInfo with the
 	// paths to the created files.
 	return hiddenAPIGenerateAllFlagsForBootclasspathFragment(ctx, contents, input)
@@ -841,7 +838,7 @@
 
 // produceHiddenAPIAllFlagsFile returns a path to the prebuilt all-flags.csv or nil if none is
 // specified.
-func (module *prebuiltBootclasspathFragmentModule) produceHiddenAPIAllFlagsFile(ctx android.ModuleContext, contents []hiddenAPIModule, _ HiddenAPIFlagInput) *HiddenAPIFlagOutput {
+func (module *prebuiltBootclasspathFragmentModule) produceHiddenAPIAllFlagsFile(ctx android.ModuleContext, contents []android.Module, _ HiddenAPIFlagInput) *HiddenAPIFlagOutput {
 	pathForOptionalSrc := func(src *string) android.Path {
 		if src == nil {
 			// TODO(b/179354495): Fail if this is not provided once prebuilts have been updated.
diff --git a/java/hiddenapi_modular.go b/java/hiddenapi_modular.go
index 5600645..643c5cb 100644
--- a/java/hiddenapi_modular.go
+++ b/java/hiddenapi_modular.go
@@ -679,11 +679,11 @@
 // * metadata.csv
 // * index.csv
 // * all-flags.csv
-func hiddenAPIGenerateAllFlagsForBootclasspathFragment(ctx android.ModuleContext, contents []hiddenAPIModule, input HiddenAPIFlagInput) *HiddenAPIFlagOutput {
+func hiddenAPIGenerateAllFlagsForBootclasspathFragment(ctx android.ModuleContext, contents []android.Module, input HiddenAPIFlagInput) *HiddenAPIFlagOutput {
 	hiddenApiSubDir := "modular-hiddenapi"
 
 	// Gather the dex files for the boot libraries provided by this fragment.
-	bootDexJars := extractBootDexJarsFromHiddenAPIModules(ctx, contents)
+	bootDexJars := extractBootDexJarsFromModules(ctx, contents)
 
 	// Generate the stub-flags.csv.
 	stubFlagsCSV := android.PathForModuleOut(ctx, hiddenApiSubDir, "stub-flags.csv")
@@ -691,7 +691,7 @@
 	rule.Build("modularHiddenAPIStubFlagsFile", "modular hiddenapi stub flags")
 
 	// Extract the classes jars from the contents.
-	classesJars := extractClassJarsFromHiddenAPIModules(ctx, contents)
+	classesJars := extractClassesJarsFromModules(contents)
 
 	// Generate the set of flags from the annotations in the source code.
 	annotationFlagsCSV := android.PathForModuleOut(ctx, hiddenApiSubDir, "annotation-flags.csv")
@@ -746,26 +746,15 @@
 	return android.OptionalPathForPath(output)
 }
 
-// gatherHiddenAPIModuleFromContents gathers the hiddenAPIModule from the supplied contents.
-func gatherHiddenAPIModuleFromContents(ctx android.ModuleContext, contents []android.Module) []hiddenAPIModule {
-	hiddenAPIModules := []hiddenAPIModule{}
-	for _, module := range contents {
-		if hiddenAPI, ok := module.(hiddenAPIModule); ok {
-			hiddenAPIModules = append(hiddenAPIModules, hiddenAPI)
-		} else if _, ok := module.(*DexImport); ok {
-			// Ignore this for the purposes of hidden API processing
-		} else {
-			ctx.ModuleErrorf("module %s does not implement hiddenAPIModule", module)
-		}
-	}
-	return hiddenAPIModules
-}
-
-// extractBootDexJarsFromHiddenAPIModules extracts the boot dex jars from the supplied modules.
-func extractBootDexJarsFromHiddenAPIModules(ctx android.ModuleContext, contents []hiddenAPIModule) android.Paths {
+// extractBootDexJarsFromModules extracts the boot dex jars from the supplied modules.
+func extractBootDexJarsFromModules(ctx android.ModuleContext, contents []android.Module) android.Paths {
 	bootDexJars := android.Paths{}
 	for _, module := range contents {
-		bootDexJar := module.bootDexJar()
+		hiddenAPIModule := hiddenAPIModuleFromModule(ctx, module)
+		if hiddenAPIModule == nil {
+			continue
+		}
+		bootDexJar := hiddenAPIModule.bootDexJar()
 		if bootDexJar == nil {
 			if ctx.Config().AlwaysUsePrebuiltSdks() {
 				// TODO(b/179354495): Remove this workaround when it is unnecessary.
@@ -793,15 +782,36 @@
 	return bootDexJars
 }
 
-// extractClassJarsFromHiddenAPIModules extracts the class jars from the supplied modules.
-func extractClassJarsFromHiddenAPIModules(ctx android.ModuleContext, contents []hiddenAPIModule) android.Paths {
+func hiddenAPIModuleFromModule(ctx android.BaseModuleContext, module android.Module) hiddenAPIModule {
+	if hiddenAPIModule, ok := module.(hiddenAPIModule); ok {
+		return hiddenAPIModule
+	} else if _, ok := module.(*DexImport); ok {
+		// Ignore this for the purposes of hidden API processing
+	} else {
+		ctx.ModuleErrorf("module %s does not implement hiddenAPIModule", module)
+	}
+
+	return nil
+}
+
+// extractClassesJarsFromModules extracts the class jars from the supplied modules.
+func extractClassesJarsFromModules(contents []android.Module) android.Paths {
 	classesJars := android.Paths{}
 	for _, module := range contents {
-		classesJars = append(classesJars, module.classesJars()...)
+		classesJars = append(classesJars, retrieveClassesJarsFromModule(module)...)
 	}
 	return classesJars
 }
 
+// retrieveClassesJarsFromModule retrieves the classes jars from the supplied module.
+func retrieveClassesJarsFromModule(module android.Module) android.Paths {
+	if hiddenAPIModule, ok := module.(hiddenAPIModule); ok {
+		return hiddenAPIModule.classesJars()
+	}
+
+	return nil
+}
+
 // deferReportingMissingBootDexJar returns true if a missing boot dex jar should not be reported by
 // Soong but should instead only be reported in ninja if the file is actually built.
 func deferReportingMissingBootDexJar(ctx android.ModuleContext, module android.Module) bool {
diff --git a/java/platform_bootclasspath.go b/java/platform_bootclasspath.go
index a4beb89..fba73d0 100644
--- a/java/platform_bootclasspath.go
+++ b/java/platform_bootclasspath.go
@@ -290,16 +290,14 @@
 	// Use the flag files from this module and all the fragments.
 	input.FlagFilesByCategory = monolithicInfo.FlagsFilesByCategory
 
-	hiddenAPIModules := gatherHiddenAPIModuleFromContents(ctx, modules)
-
 	// Generate the monolithic stub-flags.csv file.
-	bootDexJars := extractBootDexJarsFromHiddenAPIModules(ctx, hiddenAPIModules)
+	bootDexJars := extractBootDexJarsFromModules(ctx, modules)
 	stubFlags := hiddenAPISingletonPaths(ctx).stubFlags
 	rule := ruleToGenerateHiddenAPIStubFlagsFile(ctx, stubFlags, bootDexJars, input)
 	rule.Build("platform-bootclasspath-monolithic-hiddenapi-stub-flags", "monolithic hidden API stub flags")
 
 	// Extract the classes jars from the contents.
-	classesJars := extractClassJarsFromHiddenAPIModules(ctx, hiddenAPIModules)
+	classesJars := extractClassesJarsFromModules(modules)
 
 	// Generate the annotation-flags.csv file from all the module annotations.
 	annotationFlags := android.PathForModuleOut(ctx, "hiddenapi-monolithic", "annotation-flags.csv")