Collect kythe, obj and tidy files using ModuleProxy.

Bug: 358427516
Test: Manually compare the generated mk and ninja files.
Change-Id: Ibee605372b1fae48ee9fbd8872b4ea0f6b1d5a7d
diff --git a/cc/cc.go b/cc/cc.go
index 5dee32e..069a861 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -43,6 +43,14 @@
 
 var CcMakeVarsInfoProvider = blueprint.NewProvider[*CcMakeVarsInfo]()
 
+type CcObjectInfo struct {
+	objFiles   android.Paths
+	tidyFiles  android.Paths
+	kytheFiles android.Paths
+}
+
+var CcObjectInfoProvider = blueprint.NewProvider[CcObjectInfo]()
+
 func init() {
 	RegisterCCBuildComponents(android.InitRegistrationContext)
 
@@ -648,10 +656,6 @@
 	installInRoot() bool
 }
 
-type xref interface {
-	XrefCcFiles() android.Paths
-}
-
 type overridable interface {
 	overriddenModules() []string
 }
@@ -900,12 +904,6 @@
 	staticAnalogue *StaticLibraryInfo
 
 	makeLinkType string
-	// Kythe (source file indexer) paths for this compilation module
-	kytheFiles android.Paths
-	// Object .o file output paths for this compilation module
-	objFiles android.Paths
-	// Tidy .tidy file output paths for this compilation module
-	tidyFiles android.Paths
 
 	// For apex variants, this is set as apex.min_sdk_version
 	apexSdkVersion android.ApiLevel
@@ -1473,10 +1471,6 @@
 	return isBionic(name)
 }
 
-func (c *Module) XrefCcFiles() android.Paths {
-	return c.kytheFiles
-}
-
 func (c *Module) isCfiAssemblySupportEnabled() bool {
 	return c.sanitize != nil &&
 		Bool(c.sanitize.Properties.Sanitize.Config.Cfi_assembly_support)
@@ -2048,9 +2042,6 @@
 		if ctx.Failed() {
 			return
 		}
-		c.kytheFiles = objs.kytheFiles
-		c.objFiles = objs.objFiles
-		c.tidyFiles = objs.tidyFiles
 	}
 
 	if c.linker != nil {
@@ -2115,6 +2106,17 @@
 		c.hasYacc = b.hasSrcExt(ctx, ".y") || b.hasSrcExt(ctx, ".yy")
 	}
 
+	ccObjectInfo := CcObjectInfo{
+		kytheFiles: objs.kytheFiles,
+	}
+	if !ctx.Config().KatiEnabled() || !android.ShouldSkipAndroidMkProcessing(ctx, c) {
+		ccObjectInfo.objFiles = objs.objFiles
+		ccObjectInfo.tidyFiles = objs.tidyFiles
+	}
+	if len(ccObjectInfo.kytheFiles)+len(ccObjectInfo.objFiles)+len(ccObjectInfo.tidyFiles) > 0 {
+		android.SetProvider(ctx, CcObjectInfoProvider, ccObjectInfo)
+	}
+
 	c.setOutputFiles(ctx)
 
 	if c.makeVarsInfo != nil {
@@ -2122,6 +2124,12 @@
 	}
 }
 
+func setOutputFilesIfNotEmpty(ctx ModuleContext, files android.Paths, tag string) {
+	if len(files) > 0 {
+		ctx.SetOutputFiles(files, tag)
+	}
+}
+
 func (c *Module) setOutputFiles(ctx ModuleContext) {
 	if c.outputFile.Valid() {
 		ctx.SetOutputFiles(android.Paths{c.outputFile.Path()}, "")
@@ -3958,9 +3966,10 @@
 
 func (ks *kytheExtractAllSingleton) GenerateBuildActions(ctx android.SingletonContext) {
 	var xrefTargets android.Paths
-	ctx.VisitAllModules(func(module android.Module) {
-		if ccModule, ok := module.(xref); ok {
-			xrefTargets = append(xrefTargets, ccModule.XrefCcFiles()...)
+	ctx.VisitAllModuleProxies(func(module android.ModuleProxy) {
+		files := android.OtherModuleProviderOrDefault(ctx, module, CcObjectInfoProvider).kytheFiles
+		if len(files) > 0 {
+			xrefTargets = append(xrefTargets, files...)
 		}
 	})
 	// TODO(asmundak): Perhaps emit a rule to output a warning if there were no xrefTargets
diff --git a/cc/tidy.go b/cc/tidy.go
index ec1e8a2..89bae17 100644
--- a/cc/tidy.go
+++ b/cc/tidy.go
@@ -219,15 +219,11 @@
 	subsetTidyFileGroups := make(map[string]android.Paths) // subset group name => tidy file Paths
 
 	// (1) Collect all obj/tidy files into OS-specific groups.
-	ctx.VisitAllModuleVariants(module, func(variant android.Module) {
-		if ctx.Config().KatiEnabled() && android.ShouldSkipAndroidMkProcessing(ctx, variant) {
-			return
-		}
-		if m, ok := variant.(*Module); ok {
-			osName := variant.Target().Os.Name
-			addToOSGroup(osName, m.objFiles, allObjFileGroups, subsetObjFileGroups)
-			addToOSGroup(osName, m.tidyFiles, allTidyFileGroups, subsetTidyFileGroups)
-		}
+	ctx.VisitAllModuleVariantProxies(module, func(variant android.ModuleProxy) {
+		osName := android.OtherModuleProviderOrDefault(ctx, variant, android.CommonPropertiesProviderKey).CompileTarget.Os.Name
+		info := android.OtherModuleProviderOrDefault(ctx, variant, CcObjectInfoProvider)
+		addToOSGroup(osName, info.objFiles, allObjFileGroups, subsetObjFileGroups)
+		addToOSGroup(osName, info.tidyFiles, allTidyFileGroups, subsetTidyFileGroups)
 	})
 
 	// (2) Add an all-OS group, with "" or "subset" name, to include all os-specific phony targets.