wcc

src/
├── main.zig         - Main entry point and compilation pipeline orchestration
├── driver.zig       - Compiler driver handling file I/O and process management
├── lexer.zig        - Lexical analysis (tokenization)
├── Ast.zig          - Abstract Syntax Tree (AST) definitions and operations
├── Parser.zig       - Syntax analysis and AST construction
├── Sema.zig         - Semantic analysis
├── Tacky.zig        - Tacky Intermediate Representation (IR) definitions
├── TackyGen.zig     - Intermediate code generation (Tacky IR)
├── Optimizer        - Optimizer for Tacky IR
├── codegen.zig      - x86_64 assembly code generation
├── RegAllocator.zig - Register allocation and coalescing on assembly instructions
└── emit.zig         - Assembly code emission

pub const Node = struct {
    tag: Tag,
    main_token: TokenIndex,
    data: Data = .{},

    pub const Data = struct {
        lhs: Index = Index.empty,
        rhs: Index = Index.empty,
    };

    pub const Index = enum(u32) {
        empty = 0,
        _,
    };

    pub const Tag = enum(u8) {
        program,
        func_decl,
        func_def,
        func_call,
        block,
        return_stmt,
        ...
    }
}

pub const Instr = struct {
    tag: Tag,
    data: Data,

    pub const Data = packed struct(u64) {
        lhs: Index = Index.empty,
        rhs: Index = Index.empty,
    };

    pub const Index = enum(u32) {
        empty = 0,
        _,
    };

    pub const Tag = enum(u8) {
        constant,
        string_constant,
        copy,
        copyf,
        get_local,
        ...
    }
}

pub const Instr = struct {
    tag: Tag,
    data: Data = .{},

    pub const Data = struct {
        dst: Operand = .empty,
        src: Operand = .empty,
    };

    pub const Index = enum(u32) { empty = 0, _ };

    pub const OperandTag = enum(u8) {
        none,
        val,
        val_index,
        reg,
        stack,
        ...
    };
  
    pub const OperandWidth = enum(u8) {
        none,
        byte,
        word,
        dword,
        qword,
        ...
    };

    pub const Operand = struct {
        tag: OperandTag,
        width: OperandWidth = .none,
        val: u32,

        pub const empty = Operand{ .tag = .none, .val = 0 };
    }
}