lexer review: handle parsing of unsigned integers

Author: inbelic

clang/lib/Parse/ParseHLSLRootSignature.cpp

@@ -416,6 +416,8 @@ bool RootSignatureParser::ParseDescriptorRangeOffset(DescriptorRangeOffset *X) {
 }
 
 bool RootSignatureParser::ParseUInt(uint32_t *X) {
+  // Treat a postively signed integer as though it is unsigned to match DXC
+  TryConsumeExpectedToken(TokenKind::pu_plus);
   if (ConsumeExpectedToken(TokenKind::int_literal))
     return true;
 

clang/unittests/Parse/ParseHLSLRootSignatureTest.cpp

@@ -334,7 +334,7 @@ TEST_F(ParseHLSLRootSignatureTest, ValidParseDTClausesTest) {
     DescriptorTable(
       visibility = SHADER_VISIBILITY_PIXEL,
       CBV(b0),
-      SRV(t42, space = 3, offset = 32, numDescriptors = 4, flags = 0),
+      SRV(t42, space = +3, offset = 32, numDescriptors = 4, flags = 0),
       Sampler(s987, space = 2, offset = DESCRIPTOR_RANGE_OFFSET_APPEND),
       UAV(u987234,
         flags = Descriptors_Volatile | Data_Volatile