[llvm-branch-commits] [clang] [llvm] [HLSL][RootSignature] Implement Parsing of Descriptor Tables (PR #122982)

[Damyan Pepper via llvm-branch-commits]

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@@ -89,6 +91,75 @@ class RootSignatureLexer {
   }
 };
 
+class RootSignatureParser {
+public:
+  RootSignatureParser(SmallVector<RootElement> &Elements,
+                      const SmallVector<RootSignatureToken> &Tokens);
+
+  // Iterates over the provided tokens and constructs the in-memory
+  // representations of the RootElements.
+  //
+  // The return value denotes if there was a failure and the method will
+  // return on the first encountered failure, or, return false if it
+  // can sucessfully reach the end of the tokens.
+  bool Parse();
+
+private:
+  bool ReportError(); // TODO: Implement this to report error through Diags
+
+  // Root Element helpers
+  bool ParseRootElement();
+  bool ParseDescriptorTable();
+  bool ParseDescriptorTableClause();
+
+  // Common parsing helpers
+  bool ParseRegister(Register &Register);
+
+  // Various flags/enum parsing helpers
+  bool ParseDescriptorRangeFlags(DescriptorRangeFlags &Flags);
+  bool ParseShaderVisibility(ShaderVisibility &Flag);
+
+  // Increment the token iterator if we have not reached the end.
+  // Return value denotes if we were already at the last token.
+  bool ConsumeNextToken();
+
+  // Attempt to retrieve the next token, if TokenKind is invalid then there was
+  // no next token.
+  RootSignatureToken PeekNextToken();
+
+  // Is the current token one of the expected kinds
+  bool IsCurExpectedToken(ArrayRef<TokenKind> AnyExpected);
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damyanp wrote:

Any reason this doesn't have an overload that takes a single `Expected` like all the ones below?

Alternatively, if this one doesn't need the overload then do we need the other ones?

https://github.com/llvm/llvm-project/pull/122982