define ActOnStartRootSignatureDecl

Author: inbelic

clang/include/clang/Sema/Sema.h

@@ -3619,6 +3619,9 @@ class Sema final : public SemaBase {
                                       SourceLocation NameLoc,
                                       bool IsTemplateTypeArg);
 
+  std::pair<IdentifierInfo *, bool>
+  ActOnStartRootSignatureDecl(StringRef Signature);
+
   class NameClassification {
     NameClassificationKind Kind;
     union {

clang/lib/Parse/ParseDeclCXX.cpp

@@ -4942,18 +4942,13 @@ void Parser::ParseMicrosoftRootSignatureAttributeArgs(ParsedAttributes &Attrs) {
 
   // Construct our identifier
   StringRef Signature = StrLiteral.value()->getString();
-  auto Hash = llvm::hash_value(Signature);
-  std::string IdStr = "__hlsl_rootsig_decl_" + std::to_string(Hash);
-  IdentifierInfo *DeclIdent = &(Actions.getASTContext().Idents.get(IdStr));
-
-  LookupResult R(Actions, DeclIdent, SourceLocation(),
-                 Sema::LookupOrdinaryName);
-  // Check if we have already found a decl of the same name, if we haven't
-  // then parse the root signature string and construct the in-memory elements
-  if (!Actions.LookupQualifiedName(R, Actions.CurContext)) {
+  auto [DeclIdent, Found] = Actions.ActOnStartRootSignatureDecl(Signature);
+  // If we haven't found an already defined DeclIdent then parse the root
+  // signature string and construct the in-memory elements
+  if (!Found) {
+    // Offset location 1 to account for '"'
     SourceLocation SignatureLoc =
-        StrLiteral.value()->getExprLoc().getLocWithOffset(
-            1); // offset 1 for '"'
+        StrLiteral.value()->getExprLoc().getLocWithOffset(1);
     // Invoke the root signature parser to construct the in-memory constructs
     hlsl::RootSignatureLexer Lexer(Signature, SignatureLoc);
     SmallVector<llvm::hlsl::rootsig::RootElement> RootElements;

clang/lib/Sema/SemaDecl.cpp

@@ -653,6 +653,19 @@ ParsedType Sema::ActOnMSVCUnknownTypeName(const IdentifierInfo &II,
   return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
 }
 
+std::pair<IdentifierInfo *, bool>
+Sema::ActOnStartRootSignatureDecl(StringRef Signature) {
+  auto Hash = llvm::hash_value(Signature);
+  std::string IdStr = "__hlsl_rootsig_decl_" + std::to_string(Hash);
+  IdentifierInfo *DeclIdent = &(getASTContext().Idents.get(IdStr));
+
+  // Check if we have already found a decl of the same name
+  LookupResult R(Actions, DeclIdent, SourceLocation(),
+                 Sema::LookupOrdinaryName);
+  bool Found = LookupQualifiedName(R, Actions.CurContext);
+  return {DeclIdent, Found};
+}
+
 DeclSpec::TST Sema::isTagName(IdentifierInfo &II, Scope *S) {
   // Do a tag name lookup in this scope.
   LookupResult R(*this, &II, SourceLocation(), LookupTagName);