extend invalid_token diagnostic to RootFlags enum

Author: inbelic

clang/lib/Parse/ParseHLSLRootSignature.cpp

@@ -93,6 +93,10 @@ std::optional<llvm::dxbc::RootFlags> RootSignatureParser::parseRootFlags() {
 
   std::optional<llvm::dxbc::RootFlags> Flags = llvm::dxbc::RootFlags::None;
 
+  // Handle valid empty case
+  if (tryConsumeExpectedToken(TokenKind::pu_r_paren))
+    return Flags;
+
   // Handle the edge-case of '0' to specify no flags set
   if (tryConsumeExpectedToken(TokenKind::int_literal)) {
     if (!verifyZeroFlag()) {
@@ -118,6 +122,11 @@ std::optional<llvm::dxbc::RootFlags> RootSignatureParser::parseRootFlags() {
         default:
           llvm_unreachable("Switch for consumed enum token was not provided");
         }
+      } else {
+        consumeNextToken(); // consume token to point at invalid token
+        reportDiag(diag::err_hlsl_invalid_token)
+            << /*value=*/1 << /*value of*/ TokenKind::kw_RootFlags;
+        return std::nullopt;
       }
     } while (tryConsumeExpectedToken(TokenKind::pu_or));
   }

clang/test/SemaHLSL/RootSignature-err.hlsl

@@ -99,3 +99,7 @@ void bad_root_signature_21() {}
 // expected-error@+1 {{invalid value of flags}}
 [RootSignature("DescriptorTable(SRV(t0, flags = descriptor_range_flag_typo)")]
 void bad_root_signature_22() {}
+
+// expected-error@+1 {{invalid value of RootFlags}}
+[RootSignature("RootFlags(local_root_signature | root_flag_typo)")]
+void bad_root_signature_23() {}