1 files changed, 181 insertions, 0 deletions
diff --git a/backend/include/rcc/MIR/MILexer.h b/backend/include/rcc/MIR/MILexer.h
new file mode 100644
index 0000000..f54f255
--- /dev/null
+++ b/backend/include/rcc/MIR/MILexer.h
@@ -0,0 +1,181 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef RCC_MIR_MILEXER_H
+#define RCC_MIR_MILEXER_H
+
+#include "rcc/Support/TextDiagnostic.h"
+
+#include <cstddef>
+#include <cstdint>
+#include <memory>
+#include <span>
+#include <string>
+#include <string_view>
+#include <utility>
+#include <variant>
+
+namespace rcc::mir {
+
+enum class MITokenKind : std::uint8_t {
+  EndOfFile,
+  Error,
+  Newline,
+
+  Comma,
+  Equal,
+  Underscore,
+  Colon,
+  DoubleColon,
+  Dot,
+  Exclaim,
+  LeftParen,
+  RightParen,
+  LeftBrace,
+  RightBrace,
+  Plus,
+  Minus,
+  Less,
+  Greater,
+
+  Keyword,
+  MetadataKeyword,
+  Identifier,
+  NamedRegister,
+  NamedVirtualRegister,
+  MachineBasicBlockLabel,
+  MachineBasicBlock,
+  StackObject,
+  FixedStackObject,
+  NamedGlobalValue,
+  GlobalValue,
+  ExternalSymbol,
+  MCSymbol,
+  IntegerLiteral,
+  FloatingPointLiteral,
+  HexLiteral,
+  VirtualRegister,
+  ConstantPoolItem,
+  JumpTableIndex,
+  NamedIRBlock,
+  IRBlock,
+  NamedIRValue,
+  IRValue,
+  QuotedIRValue,
+  SubRegisterIndex,
+  StringConstant,
+};
+
+[[nodiscard]] std::string_view getMITokenKindName(MITokenKind Kind) noexcept;
+[[nodiscard]] bool isMIKeyword(std::string_view Spelling) noexcept;
+[[nodiscard]] bool isMIMetadataKeyword(std::string_view Spelling) noexcept;
+
+class MIToken final {
+public:
+  [[nodiscard]] MITokenKind kind() const noexcept {
+    return Kind;
+  }
+
+  [[nodiscard]] const TextRange &range() const noexcept {
+    return Range;
+  }
+
+  [[nodiscard]] std::string_view spelling() const noexcept {
+    return Spelling;
+  }
+
+  [[nodiscard]] bool hasStringValue() const noexcept {
+    return !std::holds_alternative<std::monostate>(StringValue);
+  }
+
+  [[nodiscard]] std::string_view stringValue() const noexcept;
+
+  [[nodiscard]] bool hasIntegerValue() const noexcept {
+    return !IntegerValue.empty();
+  }
+
+  [[nodiscard]] std::string_view integerValue() const noexcept {
+    return IntegerValue;
+  }
+
+  [[nodiscard]] bool is(MITokenKind Expected) const noexcept {
+    return Kind == Expected;
+  }
+
+  [[nodiscard]] bool isKeyword(std::string_view Expected) const noexcept {
+    return Kind == MITokenKind::Keyword && stringValue() == Expected;
+  }
+
+  [[nodiscard]] bool isMetadataKeyword(std::string_view Expected) const noexcept {
+    return Kind == MITokenKind::MetadataKeyword && stringValue() == Expected;
+  }
+
+  [[nodiscard]] bool isNewlineOrEnd() const noexcept {
+    return Kind == MITokenKind::Newline || Kind == MITokenKind::EndOfFile;
+  }
+
+  [[nodiscard]] bool isErrorOrEnd() const noexcept {
+    return Kind == MITokenKind::Error || Kind == MITokenKind::EndOfFile;
+  }
+
+  [[nodiscard]] bool isRegister() const noexcept;
+  [[nodiscard]] bool isRegisterFlag() const noexcept;
+  [[nodiscard]] bool isMemoryOperandFlag() const noexcept;
+
+private:
+  using StringValueStorage = std::variant<std::monostate, std::string_view, std::string>;
+
+  MIToken(MITokenKind Kind, TextRange Range, std::string_view Spelling,
+          StringValueStorage StringValue = {}, std::string_view IntegerValue = {})
+      : Kind(Kind), Range(Range), Spelling(Spelling), StringValue(std::move(StringValue)),
+        IntegerValue(IntegerValue) {}
+
+  MITokenKind Kind = MITokenKind::Error;
+  TextRange Range;
+  std::string_view Spelling;
+  StringValueStorage StringValue;
+  std::string_view IntegerValue;
+
+  friend class MILexer;
+};
+
+struct MILexerOptions final {
+  std::size_t MaximumTokenLength = std::size_t{1} << 24U;
+  std::size_t MaximumTokens = std::size_t{1} << 24U;
+};
+
+class MILexer final {
+public:
+  MILexer(std::string SourceName, std::string SourceText, MILexerOptions Options = {});
+  MILexer(const MILexer &) = delete;
+  MILexer &operator=(const MILexer &) = delete;
+  MILexer(MILexer &&) noexcept;
+  MILexer &operator=(MILexer &&) noexcept;
+  ~MILexer();
+
+  [[nodiscard]] MIToken next();
+
+  [[nodiscard]] const TextSource &source() const noexcept;
+  [[nodiscard]] std::span<const TextDiagnostic> diagnostics() const noexcept;
+  [[nodiscard]] bool failed() const noexcept;
+  [[nodiscard]] std::size_t tokenCount() const noexcept;
+
+private:
+  [[nodiscard]] static MIToken makeToken(MITokenKind Kind, TextRange Range,
+                                         std::string_view Spelling,
+                                         std::string_view IntegerValue = {});
+  [[nodiscard]] static MIToken makeStringToken(MITokenKind Kind, TextRange Range,
+                                               std::string_view Spelling,
+                                               std::string_view StringValue,
+                                               std::string_view IntegerValue = {});
+  [[nodiscard]] static MIToken makeOwnedStringToken(MITokenKind Kind, TextRange Range,
+                                                    std::string_view Spelling,
+                                                    std::string StringValue,
+                                                    std::string_view IntegerValue = {});
+
+  class Impl;
+  std::unique_ptr<Impl> Implementation;
+};
+
+} // namespace rcc::mir
+
+#endif // RCC_MIR_MILEXER_H