Parser and Assembler implementations

Source/Core/Common/Assembler/GekkoParser.h

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+// Copyright 2023 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <optional>
+#include <string>
+#include <string_view>
+
+#include "Common/Assembler/AssemblerShared.h"
+#include "Common/Assembler/GekkoLexer.h"
+#include "Common/CommonTypes.h"
+
+namespace Common::GekkoAssembler::detail
+{
+class ParsePlugin;
+
+struct ParseState
+{
+  ParseState(std::string_view input_str, ParsePlugin& plugin);
+
+  bool HasToken(TokenType tp) const;
+  void ParseToken(TokenType tp);
+  void EmitErrorHere(std::string&& message);
+
+  Lexer lexer;
+  ParsePlugin& plugin;
+
+  std::optional<AssemblerError> error;
+  bool eof;
+};
+
+enum class AsmOp
+{
+  Or,
+  Xor,
+  And,
+  Lsh,
+  Rsh,
+  Add,
+  Sub,
+  Mul,
+  Div,
+  Neg,
+  Not
+};
+
+enum class Terminal
+{
+  Hex,
+  Dec,
+  Oct,
+  Bin,
+  Flt,
+  Str,
+  Id,
+  GPR,
+  FPR,
+  SPR,
+  CRField,
+  Lt,
+  Gt,
+  Eq,
+  So,
+  Dot,
+};
+
+enum class ParenType
+{
+  Normal,
+  RelConv,
+};
+
+// Overridable plugin class supporting a series of skeleton functions which get called when
+// the parser parses a given point of interest
+class ParsePlugin
+{
+public:
+  ParsePlugin() : m_owner(nullptr) {}
+  virtual ~ParsePlugin() = default;
+
+  void SetOwner(ParseState* o) { m_owner = o; }
+  void ForwardError(AssemblerError&& err) { m_owner_error = std::move(err); }
+  std::optional<AssemblerError>& Error() { return m_owner_error; }
+
+  virtual void PostParseAction() {}
+
+  // Nonterminal callouts
+  // Pre occurs prior to the head nonterminal being parsed
+  // Post occurs after the nonterminal has been fully parsed
+  virtual void OnDirectivePre(GekkoDirective directive) {}
+  virtual void OnDirectivePost(GekkoDirective directive) {}
+  virtual void OnInstructionPre(const ParseInfo& mnemonic_info, bool extended) {}
+  virtual void OnInstructionPost(const ParseInfo& mnemonic_info, bool extended) {}
+  virtual void OnOperandPre() {}
+  virtual void OnOperandPost() {}
+  virtual void OnResolvedExprPre() {}
+  virtual void OnResolvedExprPost() {}
+
+  // Operator callouts
+  // All occur after the relevant operands have been parsed
+  virtual void OnOperator(AsmOp operation) {}
+
+  // Individual token callouts
+  // All occur prior to the token being parsed
+  // Due to ambiguity of some tokens, an explicit operation is provided
+  virtual void OnTerminal(Terminal type, const AssemblerToken& val) {}
+  virtual void OnHiaddr(std::string_view id) {}
+  virtual void OnLoaddr(std::string_view id) {}
+  virtual void OnOpenParen(ParenType type) {}
+  virtual void OnCloseParen(ParenType type) {}
+  virtual void OnError() {}
+  virtual void OnLabelDecl(std::string_view name) {}
+  virtual void OnVarDecl(std::string_view name) {}
+
+protected:
+  ParseState* m_owner;
+  std::optional<AssemblerError> m_owner_error;
+};
+
+// Parse the provided input with a plugin to handle what to do with certain points of interest
+// e.g. Convert to an IR for generating final machine code, picking up syntactical information
+void ParseWithPlugin(ParsePlugin* plugin, std::string_view input);
+}  // namespace Common::GekkoAssembler::detail