Use modular removed-dex.txt files for greylisting.

Use droidstubs for public and system stubs to provide a list of @removed APIs. As these APIs are not present in the stubs, they are not whitelisted / greylised automatically. Keep them on greylist manually.

Bug: 143864733
Test: diff out/soong/hiddenapi/hiddenapi-flags.csv
Change-Id: I4c8e6899fadfdfd1da82f6f453cc92e71aa9b78c
Merged-In: I4c8e6899fadfdfd1da82f6f453cc92e71aa9b78c
Exempt-From-Owner-Approval: clean cherry-pick
(cherry picked from commit c7fb5c99644d2434c9e6c957f7366d0467284211)

1 files changed, 16 insertions, 10 deletions

diff --git a/java/hiddenapi_singleton.go b/java/hiddenapi_singleton.go
index 7e7e955f5..c7f7cbdfe 100644
--- a/java/hiddenapi_singleton.go
+++ b/java/hiddenapi_singleton.go
@@ -211,23 +211,30 @@ func stubFlagsRule(ctx android.SingletonContext) {
 // the greylists.
 func flagsRule(ctx android.SingletonContext) android.Path {
 	var flagsCSV android.Paths
-
-	var greylistIgnoreConflicts android.Path
+	var greylistRemovedApis android.Paths
 
 	ctx.VisitAllModules(func(module android.Module) {
 		if h, ok := module.(hiddenAPIIntf); ok {
 			if csv := h.flagsCSV(); csv != nil {
 				flagsCSV = append(flagsCSV, csv)
 			}
-		} else if ds, ok := module.(*Droidstubs); ok && ctx.ModuleName(module) == "hiddenapi-lists-docs" {
-			greylistIgnoreConflicts = ds.removedDexApiFile
+		} else if ds, ok := module.(*Droidstubs); ok {
+			// Track @removed public and system APIs via corresponding droidstubs targets.
+			// These APIs are not present in the stubs, however, we have to keep allowing access
+			// to them at runtime.
+			if m := ctx.ModuleName(module); m == "api-stubs-docs" || m == "system-api-stubs-docs" {
+				greylistRemovedApis = append(greylistRemovedApis, ds.removedDexApiFile)
+			}
 		}
 	})
 
-	if greylistIgnoreConflicts == nil {
-		ctx.Errorf("failed to find removed_dex_api_filename from hiddenapi-lists-docs module")
-		return nil
-	}
+	combinedRemovedApis := android.PathForOutput(ctx, "hiddenapi", "combined-removed-dex.txt")
+	ctx.Build(pctx, android.BuildParams{
+		Rule:        android.Cat,
+		Inputs:      greylistRemovedApis,
+		Output:      combinedRemovedApis,
+		Description: "Combine removed apis for " + combinedRemovedApis.String(),
+	})
 
 	rule := android.NewRuleBuilder()
 
@@ -242,8 +249,7 @@ func flagsRule(ctx android.SingletonContext) android.Path {
 		Inputs(flagsCSV).
 		FlagWithInput("--greylist ",
 			android.PathForSource(ctx, "frameworks/base/config/hiddenapi-greylist.txt")).
-		FlagWithInput("--greylist-ignore-conflicts ",
-			greylistIgnoreConflicts).
+		FlagWithInput("--greylist-ignore-conflicts ", combinedRemovedApis).
 		FlagWithInput("--greylist-max-q ",
 			android.PathForSource(ctx, "frameworks/base/config/hiddenapi-greylist-max-q.txt")).
 		FlagWithInput("--greylist-max-p ",