Add diff_flags as a header_abi_checker property

The property allows developers to add extra flags to header-abi-diff for
specific libraries.

Bug: 232891473
Test: m libbinder.vendor
Change-Id: I203af73c784dfc7738bb64f57b224c08d5c595ce

cc/builder.go

@@ -942,9 +942,10 @@ func unzipRefDump(ctx android.ModuleContext, zippedRefDump android.Path, baseNam
 	return outputFile
 }
 
-// sourceAbiDiff registers a build statement to compare linked sAbi dump files (.ldump).
+// sourceAbiDiff registers a build statement to compare linked sAbi dump files (.lsdump).
 func sourceAbiDiff(ctx android.ModuleContext, inputDump android.Path, referenceDump android.Path,
-	baseName, exportedHeaderFlags string, checkAllApis, isLlndk, isNdk, isVndkExt bool) android.OptionalPath {
+	baseName, exportedHeaderFlags string, diffFlags []string,
+	checkAllApis, isLlndk, isNdk, isVndkExt bool) android.OptionalPath {
 
 	outputFile := android.PathForModuleOut(ctx, baseName+".abidiff")
 	libName := strings.TrimSuffix(baseName, filepath.Ext(baseName))
@@ -975,6 +976,8 @@ func sourceAbiDiff(ctx android.ModuleContext, inputDump android.Path, referenceD
 	if isVndkExt {
 		extraFlags = append(extraFlags, "-allow-extensions")
 	}
+	// TODO(b/232891473): Simplify the above logic with diffFlags.
+	extraFlags = append(extraFlags, diffFlags...)
 
 	ctx.Build(pctx, android.BuildParams{
 		Rule:        sAbiDiff,

cc/library.go

@@ -110,6 +110,9 @@ type LibraryProperties struct {
 		// Run checks on all APIs (in addition to the ones referred by
 		// one of exported ELF symbols.)
 		Check_all_apis *bool
+
+		// Extra flags passed to header-abi-diff
+		Diff_flags []string
 	}
 
 	// Inject boringssl hash into the shared library.  This is only intended for use by external/boringssl.
@@ -1638,6 +1641,7 @@ func (library *libraryDecorator) linkSAbiDumpFiles(ctx ModuleContext, objs Objec
 		if refAbiDumpFile != nil {
 			library.sAbiDiff = sourceAbiDiff(ctx, library.sAbiOutputFile.Path(),
 				refAbiDumpFile, fileName, exportedHeaderFlags,
+				library.Properties.Header_abi_checker.Diff_flags,
 				Bool(library.Properties.Header_abi_checker.Check_all_apis),
 				ctx.IsLlndk(), ctx.isNdk(ctx.Config()), ctx.IsVndkExt())
 		}