[HLSL][RootSignature] Implement Lexing of DescriptorTables

clang/include/clang/Basic/DiagnosticLexKinds.td

@@ -1017,4 +1017,15 @@ Error<"'#pragma unsafe_buffer_usage' was not ended">;
 
 def err_pp_pragma_unsafe_buffer_usage_syntax :
 Error<"expected 'begin' or 'end'">;
+
+// HLSL Root Signature Lexing Errors
+let CategoryName = "Root Signature Lexical Issue" in {
+  def err_hlsl_expected_number_literal: Error<"expected numberic literal">;
+  def err_hlsl_number_literal_overflow :
+    Error<"integer literal is too large to be represented in any %select{signed |}0 integer type">;
+  def err_hlsl_invalid_token: Error<"unable to lex a valid Root Signature token">;
+  def err_hlsl_invalid_register_literal: Error<"expected unsigned integer literal as part of register">;
+  def err_hlsl_rootsig_unexpected_eos : Error<"unexpected end to token stream">;
+}
+
 }

clang/include/clang/Parse/HLSLRootSignatureTokenKinds.def

@@ -0,0 +1,122 @@
+//===--- HLSLRootSignature.def - Tokens and Enum Database -------*- C++ -*-===//
+
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the TokenKinds used in the Root Signature DSL. This
+// includes keywords, enums and a small subset of punctuators. Users of this
+// file must optionally #define the TOK, KEYWORD, ENUM or specific ENUM macros
+// to make use of this file.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef TOK
+#define TOK(X)
+#endif
+#ifndef PUNCTUATOR
+#define PUNCTUATOR(X,Y) TOK(pu_ ## X)
+#endif
+#ifndef KEYWORD
+#define KEYWORD(X) TOK(kw_ ## X)
+#endif
+#ifndef ENUM
+#define ENUM(NAME, LIT) TOK(en_ ## NAME)
+#endif
+
+// Defines the various types of enum
+#ifndef DESCRIPTOR_RANGE_OFFSET_ENUM
+#define DESCRIPTOR_RANGE_OFFSET_ENUM(NAME, LIT) ENUM(NAME, LIT)
+#endif
+#ifndef ROOT_DESCRIPTOR_FLAG_ENUM
+#define ROOT_DESCRIPTOR_FLAG_ENUM(NAME, LIT) ENUM(NAME, LIT)
+#endif
+// Note: ON denotes that the flag is unique from the above Root Descriptor
+//  Flags. This is required to avoid token kind enum conflicts.
+#ifndef DESCRIPTOR_RANGE_FLAG_ENUM_OFF
+#define DESCRIPTOR_RANGE_FLAG_ENUM_OFF(NAME, LIT)
+#endif
+#ifndef DESCRIPTOR_RANGE_FLAG_ENUM_ON
+#define DESCRIPTOR_RANGE_FLAG_ENUM_ON(NAME, LIT) ENUM(NAME, LIT)
+#endif
+#ifndef DESCRIPTOR_RANGE_FLAG_ENUM
+#define DESCRIPTOR_RANGE_FLAG_ENUM(NAME, LIT, ON) DESCRIPTOR_RANGE_FLAG_ENUM_##ON(NAME, LIT)
+#endif
+#ifndef SHADER_VISIBILITY_ENUM
+#define SHADER_VISIBILITY_ENUM(NAME, LIT) ENUM(NAME, LIT)
+#endif
+
+// General Tokens:
+TOK(invalid)
+TOK(end_of_stream)
+TOK(int_literal)
+
+// Register Tokens:
+TOK(bReg)
+TOK(tReg)
+TOK(uReg)
+TOK(sReg)
+
+// Punctuators:
+PUNCTUATOR(l_paren, '(')
+PUNCTUATOR(r_paren, ')')
+PUNCTUATOR(comma,   ',')
+PUNCTUATOR(or,      '|')
+PUNCTUATOR(equal,   '=')
+
+// RootElement Keywords:
+KEYWORD(DescriptorTable)
+
+// DescriptorTable Keywords:
+KEYWORD(CBV)
+KEYWORD(SRV)
+KEYWORD(UAV)
+KEYWORD(Sampler)
+
+// General Parameter Keywords:
+KEYWORD(space)
+KEYWORD(visibility)
+KEYWORD(flags)
+
+// View Parameter Keywords:
+KEYWORD(numDescriptors)
+KEYWORD(offset)
+
+// Descriptor Range Offset Enum:
+DESCRIPTOR_RANGE_OFFSET_ENUM(DescriptorRangeOffsetAppend, "DESCRIPTOR_RANGE_OFFSET_APPEND")
+
+// Root Descriptor Flag Enums:
+ROOT_DESCRIPTOR_FLAG_ENUM(DataVolatile, "DATA_VOLATILE")
+ROOT_DESCRIPTOR_FLAG_ENUM(DataStaticWhileSetAtExecute, "DATA_STATIC_WHILE_SET_AT_EXECUTE")
+ROOT_DESCRIPTOR_FLAG_ENUM(DataStatic, "DATA_STATIC")
+
+// Descriptor Range Flag Enums:
+DESCRIPTOR_RANGE_FLAG_ENUM(DescriptorsVolatile, "DESCRIPTORS_VOLATILE", ON)
+DESCRIPTOR_RANGE_FLAG_ENUM(DataVolatile, "DATA_VOLATILE", OFF)
+DESCRIPTOR_RANGE_FLAG_ENUM(DataStaticWhileSetAtExecute, "DATA_STATIC_WHILE_SET_AT_EXECUTE", OFF)
+DESCRIPTOR_RANGE_FLAG_ENUM(DataStatic, "DATA_STATIC", OFF)
+DESCRIPTOR_RANGE_FLAG_ENUM(DescriptorsStaticKeepingBufferBoundsChecks, "DESCRIPTORS_STATIC_KEEPING_BUFFER_BOUNDS_CHECKS", ON)
+
+// Shader Visibiliy Enums:
+SHADER_VISIBILITY_ENUM(All, "SHADER_VISIBILITY_ALL")
+SHADER_VISIBILITY_ENUM(Vertex, "SHADER_VISIBILITY_VERTEX")
+SHADER_VISIBILITY_ENUM(Hull, "SHADER_VISIBILITY_HULL")
+SHADER_VISIBILITY_ENUM(Domain, "SHADER_VISIBILITY_DOMAIN")
+SHADER_VISIBILITY_ENUM(Geometry, "SHADER_VISIBILITY_GEOMETRY")
+SHADER_VISIBILITY_ENUM(Pixel, "SHADER_VISIBILITY_PIXEL")
+SHADER_VISIBILITY_ENUM(Amplification, "SHADER_VISIBILITY_AMPLIFICATION")
+SHADER_VISIBILITY_ENUM(Mesh, "SHADER_VISIBILITY_MESH")
+
+#undef SHADER_VISIBILITY_ENUM
+#undef DESCRIPTOR_RANGE_FLAG_ENUM
+#undef DESCRIPTOR_RANGE_FLAG_ENUM_OFF
+#undef DESCRIPTOR_RANGE_FLAG_ENUM_ON
+#undef ROOT_DESCRIPTOR_FLAG_ENUM
+#undef DESCRIPTOR_RANGE_OFFSET_ENUM
+#undef ENUM
+#undef KEYWORD
+#undef PUNCTUATOR
+#undef TOK

clang/include/clang/Parse/ParseHLSLRootSignature.h

@@ -0,0 +1,99 @@
+//===--- ParseHLSLRootSignature.h -------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the ParseHLSLRootSignature interface.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_PARSE_PARSEHLSLROOTSIGNATURE_H
+#define LLVM_CLANG_PARSE_PARSEHLSLROOTSIGNATURE_H
+
+#include "clang/AST/APValue.h"
+#include "clang/Basic/DiagnosticLex.h"
+#include "clang/Lex/LiteralSupport.h"
+#include "clang/Lex/Preprocessor.h"
+
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/StringSwitch.h"
+
+namespace clang {
+namespace hlsl {
+
+struct RootSignatureToken {
+  enum Kind {
+#define TOK(X) X,
+#include "clang/Parse/HLSLRootSignatureTokenKinds.def"
+  };
+
+  Kind Kind = Kind::invalid;
+
+  // Retain the SouceLocation of the token for diagnostics
+  clang::SourceLocation TokLoc;
+
+  APValue NumLiteral = APValue();
+
+  // Constructors
+  RootSignatureToken() : TokLoc(SourceLocation()) {}
+  RootSignatureToken(clang::SourceLocation TokLoc) : TokLoc(TokLoc) {}
+  RootSignatureToken(enum Kind Kind, clang::SourceLocation TokLoc)
+      : Kind(Kind), TokLoc(TokLoc) {}
+};
+using TokenKind = enum RootSignatureToken::Kind;
+
+class RootSignatureLexer {
+public:
+  RootSignatureLexer(StringRef Signature, clang::SourceLocation SourceLoc,
+                     clang::Preprocessor &PP)
+      : Buffer(Signature), SourceLoc(SourceLoc), PP(PP) {}
+
+  /// Updates CurToken to the next token. Either it will take the previously
+  /// lexed NextToken, or it will lex a token.
+  ///
+  /// The return value denotes if there was a failure.
+  bool ConsumeToken();
+
+  /// Returns the token that comes after CurToken or std::nullopt if an
+  /// error is encountered during lexing of the next token.
+  std::optional<RootSignatureToken> PeekNextToken();
+
+  RootSignatureToken GetCurToken() { return CurToken; }
+
+  /// Check if we have reached the end of input
+  bool EndOfBuffer() {
+    AdvanceBuffer(Buffer.take_while(isspace).size());
+    return Buffer.empty();
+  }
+
+private:
+  // Internal buffer to iterate over
+  StringRef Buffer;
+
+  // Current Token state
+  RootSignatureToken CurToken;
+  std::optional<RootSignatureToken> NextToken = std::nullopt;
+
+  // Passed down parameters from Sema
+  clang::SourceLocation SourceLoc;
+  clang::Preprocessor &PP;
+
+  bool LexNumber(RootSignatureToken &Result);
+  bool LexToken(RootSignatureToken &Result);
+
+  // Advance the buffer by the specified number of characters. Updates the
+  // SourceLocation appropriately.
+  void AdvanceBuffer(unsigned NumCharacters = 1) {
+    Buffer = Buffer.drop_front(NumCharacters);
+    SourceLoc = SourceLoc.getLocWithOffset(NumCharacters);
+  }
+};
+
+} // namespace hlsl
+} // namespace clang
+
+#endif // LLVM_CLANG_PARSE_PARSEHLSLROOTSIGNATURE_H

clang/lib/Parse/CMakeLists.txt

@@ -14,6 +14,7 @@ add_clang_library(clangParse
   ParseExpr.cpp
   ParseExprCXX.cpp
   ParseHLSL.cpp
+  ParseHLSLRootSignature.cpp
   ParseInit.cpp
   ParseObjc.cpp
   ParseOpenMP.cpp