feat: separate main.c

10 files changed, 2704 insertions, 2668 deletions

diff --git a/analyze.c b/analyze.c
new file mode 100644
index 0000000..53ce1b4
--- /dev/null
+++ b/analyze.c
@@ -0,0 +1,2 @@
+void analyze(Program* prog) {
+}
diff --git a/ast.c b/ast.c
new file mode 100644
index 0000000..ad5b83f
--- /dev/null
+++ b/ast.c
@@ -0,0 +1,352 @@
+enum TypeKind {
+    TypeKind_unknown,
+
+    TypeKind_char,
+    TypeKind_int,
+    TypeKind_long,
+    TypeKind_void,
+    TypeKind_ptr,
+    TypeKind_enum,
+    TypeKind_struct,
+};
+typedef enum TypeKind TypeKind;
+
+struct AstNode;
+
+struct Type {
+    TypeKind kind;
+    struct Type* to;
+    struct AstNode* def;
+};
+typedef struct Type Type;
+
+Type* type_new(TypeKind kind) {
+    Type* ty = calloc(1, sizeof(Type));
+    ty->kind = kind;
+    return ty;
+}
+
+Type* type_new_ptr(Type* to) {
+    Type* ty = calloc(1, sizeof(Type));
+    ty->kind = TypeKind_ptr;
+    ty->to = to;
+    return ty;
+}
+
+int type_is_unsized(Type* ty) {
+    return ty->kind != TypeKind_void;
+}
+
+int type_sizeof_struct(Type* ty);
+int type_alignof_struct(Type* ty);
+int type_offsetof(Type* ty, const String* name);
+Type* type_member_typeof(Type* ty, const String* name);
+
+int type_sizeof(Type* ty) {
+    if (!type_is_unsized(ty)) {
+        fatal_error("type_sizeof: type size cannot be determined");
+    }
+
+    if (ty->kind == TypeKind_ptr) {
+        return 8;
+    } else if (ty->kind == TypeKind_char) {
+        return 1;
+    } else if (ty->kind == TypeKind_int) {
+        return 4;
+    } else if (ty->kind == TypeKind_long) {
+        return 8;
+    } else if (ty->kind == TypeKind_enum) {
+        return 4;
+    } else {
+        return type_sizeof_struct(ty);
+    }
+}
+
+int type_alignof(Type* ty) {
+    if (!type_is_unsized(ty)) {
+        fatal_error("type_alignof: type size cannot be determined");
+    }
+
+    if (ty->kind == TypeKind_ptr) {
+        return 8;
+    } else if (ty->kind == TypeKind_char) {
+        return 1;
+    } else if (ty->kind == TypeKind_int) {
+        return 4;
+    } else if (ty->kind == TypeKind_long) {
+        return 8;
+    } else if (ty->kind == TypeKind_enum) {
+        return 4;
+    } else {
+        return type_alignof_struct(ty);
+    }
+}
+
+enum AstNodeKind {
+    AstNodeKind_unknown,
+
+    AstNodeKind_assign_expr,
+    AstNodeKind_binary_expr,
+    AstNodeKind_break_stmt,
+    AstNodeKind_continue_stmt,
+    AstNodeKind_deref_expr,
+    AstNodeKind_do_while_stmt,
+    AstNodeKind_enum_def,
+    AstNodeKind_enum_member,
+    AstNodeKind_expr_stmt,
+    AstNodeKind_for_stmt,
+    AstNodeKind_func_call,
+    AstNodeKind_func_decl,
+    AstNodeKind_func_def,
+    AstNodeKind_gvar,
+    AstNodeKind_gvar_decl,
+    AstNodeKind_if_stmt,
+    AstNodeKind_int_expr,
+    AstNodeKind_list,
+    AstNodeKind_logical_expr,
+    AstNodeKind_lvar,
+    AstNodeKind_lvar_decl,
+    AstNodeKind_param,
+    AstNodeKind_ref_expr,
+    AstNodeKind_return_stmt,
+    AstNodeKind_str_expr,
+    AstNodeKind_struct_decl,
+    AstNodeKind_struct_def,
+    AstNodeKind_struct_member,
+    AstNodeKind_type,
+    AstNodeKind_typedef_decl,
+    AstNodeKind_unary_expr,
+};
+typedef enum AstNodeKind AstNodeKind;
+
+#define node_items __n1
+#define node_len __i
+#define node_expr __n1
+#define node_lhs __n1
+#define node_rhs __n2
+#define node_operand __n1
+#define node_cond __n1
+#define node_init __n2
+#define node_update __n3
+#define node_then __n2
+#define node_else __n3
+#define node_body __n4
+#define node_members __n1
+#define node_params __n1
+#define node_args __n1
+#define node_int_value __i
+#define node_idx __i
+#define node_op __i
+
+struct AstNode {
+    AstNodeKind kind;
+    String name;
+    Type* ty;
+    struct AstNode* __n1;
+    struct AstNode* __n2;
+    struct AstNode* __n3;
+    struct AstNode* __n4;
+    int __i;
+};
+typedef struct AstNode AstNode;
+
+struct Program {
+    AstNode* funcs;
+    char** str_literals;
+};
+typedef struct Program Program;
+
+AstNode* ast_new(AstNodeKind kind) {
+    AstNode* ast = calloc(1, sizeof(AstNode));
+    ast->kind = kind;
+    return ast;
+}
+
+AstNode* ast_new_list(int capacity) {
+    AstNode* list = ast_new(AstNodeKind_list);
+    list->node_items = calloc(capacity, sizeof(AstNode));
+    list->node_len = 0;
+    return list;
+}
+
+void ast_append(AstNode* list, AstNode* item) {
+    if (list->kind != AstNodeKind_list) {
+        fatal_error("ast_append: ast is not a list");
+    }
+    if (!item) {
+        return;
+    }
+    memcpy(list->node_items + list->node_len, item, sizeof(AstNode));
+    ++list->node_len;
+}
+
+AstNode* ast_new_int(int v) {
+    AstNode* e = ast_new(AstNodeKind_int_expr);
+    e->node_int_value = v;
+    e->ty = type_new(TypeKind_int);
+    return e;
+}
+
+AstNode* ast_new_unary_expr(int op, AstNode* operand) {
+    AstNode* e = ast_new(AstNodeKind_unary_expr);
+    e->node_op = op;
+    e->node_operand = operand;
+    e->ty = type_new(TypeKind_int);
+    return e;
+}
+
+AstNode* ast_new_binary_expr(int op, AstNode* lhs, AstNode* rhs) {
+    AstNode* e = ast_new(AstNodeKind_binary_expr);
+    e->node_op = op;
+    e->node_lhs = lhs;
+    e->node_rhs = rhs;
+    if (op == TokenKind_plus) {
+        if (lhs->ty->kind == TypeKind_ptr) {
+            e->ty = lhs->ty;
+        } else if (rhs->ty->kind == TypeKind_ptr) {
+            e->ty = rhs->ty;
+        } else {
+            e->ty = type_new(TypeKind_int);
+        }
+    } else if (op == TokenKind_minus) {
+        if (lhs->ty->kind == TypeKind_ptr) {
+            e->ty = lhs->ty;
+        } else {
+            e->ty = type_new(TypeKind_int);
+        }
+    } else {
+        e->ty = type_new(TypeKind_int);
+    }
+    return e;
+}
+
+AstNode* ast_new_assign_expr(int op, AstNode* lhs, AstNode* rhs) {
+    AstNode* e = ast_new(AstNodeKind_assign_expr);
+    e->node_op = op;
+    e->node_lhs = lhs;
+    e->node_rhs = rhs;
+    e->ty = lhs->ty;
+    return e;
+}
+
+AstNode* ast_new_assign_add_expr(AstNode* lhs, AstNode* rhs) {
+    if (lhs->ty->kind == TypeKind_ptr) {
+        rhs = ast_new_binary_expr(TokenKind_star, rhs, ast_new_int(type_sizeof(lhs->ty->to)));
+    } else if (rhs->ty->kind == TypeKind_ptr) {
+        lhs = ast_new_binary_expr(TokenKind_star, lhs, ast_new_int(type_sizeof(rhs->ty->to)));
+    }
+    return ast_new_assign_expr(TokenKind_assign_add, lhs, rhs);
+}
+
+AstNode* ast_new_assign_sub_expr(AstNode* lhs, AstNode* rhs) {
+    if (lhs->ty->kind == TypeKind_ptr) {
+        rhs = ast_new_binary_expr(TokenKind_star, rhs, ast_new_int(type_sizeof(lhs->ty->to)));
+    }
+    return ast_new_assign_expr(TokenKind_assign_sub, lhs, rhs);
+}
+
+AstNode* ast_new_ref_expr(AstNode* operand) {
+    AstNode* e = ast_new(AstNodeKind_ref_expr);
+    e->node_operand = operand;
+    e->ty = type_new_ptr(operand->ty);
+    return e;
+}
+
+AstNode* ast_new_deref_expr(AstNode* operand) {
+    AstNode* e = ast_new(AstNodeKind_deref_expr);
+    e->node_operand = operand;
+    e->ty = operand->ty->to;
+    return e;
+}
+
+AstNode* ast_new_member_access_expr(AstNode* obj, const String* name) {
+    AstNode* e = ast_new(AstNodeKind_deref_expr);
+    e->node_operand = ast_new_binary_expr(TokenKind_plus, obj, ast_new_int(type_offsetof(obj->ty->to, name)));
+    e->ty = type_member_typeof(obj->ty->to, name);
+    e->node_operand->ty = type_new_ptr(e->ty);
+    return e;
+}
+
+int type_sizeof_struct(Type* ty) {
+    int next_offset = 0;
+    int struct_align = 0;
+    int padding;
+
+    int i;
+    for (i = 0; i < ty->def->node_members->node_len; ++i) {
+        AstNode* member = ty->def->node_members->node_items + i;
+        int size = type_sizeof(member->ty);
+        int align = type_alignof(member->ty);
+
+        if (next_offset % align != 0) {
+            padding = align - next_offset % align;
+            next_offset += padding;
+        }
+        next_offset += size;
+        if (struct_align < align) {
+            struct_align = align;
+        }
+    }
+    if (next_offset % struct_align != 0) {
+        padding = struct_align - next_offset % struct_align;
+        next_offset += padding;
+    }
+    return next_offset;
+}
+
+int type_alignof_struct(Type* ty) {
+    int struct_align = 0;
+
+    int i;
+    for (i = 0; i < ty->def->node_members->node_len; ++i) {
+        AstNode* member = ty->def->node_members->node_items + i;
+        int align = type_alignof(member->ty);
+
+        if (struct_align < align) {
+            struct_align = align;
+        }
+    }
+    return struct_align;
+}
+
+int type_offsetof(Type* ty, const String* name) {
+    if (ty->kind != TypeKind_struct) {
+        fatal_error("type_offsetof: type is not a struct");
+    }
+
+    int next_offset = 0;
+
+    int i;
+    for (i = 0; i < ty->def->node_members->node_len; ++i) {
+        AstNode* member = ty->def->node_members->node_items + i;
+        int size = type_sizeof(member->ty);
+        int align = type_alignof(member->ty);
+
+        if (next_offset % align != 0) {
+            int padding = align - next_offset % align;
+            next_offset += padding;
+        }
+        if (string_equals(&member->name, name)) {
+            return next_offset;
+        }
+        next_offset += size;
+    }
+
+    fatal_error("type_offsetof: member not found");
+}
+
+Type* type_member_typeof(Type* ty, const String* name) {
+    if (ty->kind != TypeKind_struct) {
+        fatal_error("type_offsetof: type is not a struct");
+    }
+
+    int i;
+    for (i = 0; i < ty->def->node_members->node_len; ++i) {
+        AstNode* member = ty->def->node_members->node_items + i;
+        if (string_equals(&member->name, name)) {
+            return member->ty;
+        }
+    }
+
+    fatal_error("type_offsetof: member not found");
+}
diff --git a/codegen.c b/codegen.c
new file mode 100644
index 0000000..26e7604
--- /dev/null
+++ b/codegen.c
@@ -0,0 +1,439 @@
+enum GenMode {
+    GenMode_lval,
+    GenMode_rval,
+};
+typedef enum GenMode GenMode;
+
+struct CodeGen {
+    int next_label;
+    int* loop_labels;
+};
+typedef struct CodeGen CodeGen;
+
+CodeGen* codegen_new() {
+    CodeGen* g = calloc(1, sizeof(CodeGen));
+    g->next_label = 1;
+    g->loop_labels = calloc(1024, sizeof(int));
+    return g;
+}
+
+int codegen_new_label(CodeGen* g) {
+    int new_label = g->next_label;
+    ++g->next_label;
+    return new_label;
+}
+
+void codegen_expr(CodeGen* g, AstNode* ast, GenMode gen_mode);
+void codegen_stmt(CodeGen* g, AstNode* ast);
+
+const char* param_reg(int n) {
+    if (n == 0) {
+        return "rdi";
+    } else if (n == 1) {
+        return "rsi";
+    } else if (n == 2) {
+        return "rdx";
+    } else if (n == 3) {
+        return "rcx";
+    } else if (n == 4) {
+        return "r8";
+    } else if (n == 5) {
+        return "r9";
+    } else {
+        unreachable();
+    }
+}
+
+void codegen_func_prologue(CodeGen* g, AstNode* ast) {
+    printf("  push rbp\n");
+    printf("  mov rbp, rsp\n");
+    int i;
+    for (i = 0; i < ast->node_params->node_len; ++i) {
+        printf("  push %s\n", param_reg(i));
+    }
+    printf("  sub rsp, %d\n", 8 * LVAR_MAX);
+}
+
+void codegen_func_epilogue(CodeGen* g, AstNode* ast) {
+    printf("  mov rsp, rbp\n");
+    printf("  pop rbp\n");
+    printf("  ret\n");
+}
+
+void codegen_int_expr(CodeGen* g, AstNode* ast) {
+    printf("  push %d\n", ast->node_int_value);
+}
+
+void codegen_str_expr(CodeGen* g, AstNode* ast) {
+    printf("  mov rax, OFFSET FLAG:.Lstr__%d\n", ast->node_idx);
+    printf("  push rax\n");
+}
+
+void codegen_unary_expr(CodeGen* g, AstNode* ast) {
+    codegen_expr(g, ast->node_operand, GenMode_rval);
+    if (ast->node_op == TokenKind_not) {
+        printf("  pop rax\n");
+        printf("  mov rdi, 0\n");
+        printf("  cmp rax, rdi\n");
+        printf("  sete al\n");
+        printf("  movzb rax, al\n");
+        printf("  push rax\n");
+    } else {
+        unreachable();
+    }
+}
+
+void codegen_ref_expr(CodeGen* g, AstNode* ast, GenMode gen_mode) {
+    codegen_expr(g, ast->node_operand, GenMode_lval);
+}
+
+void codegen_lval2rval(Type* ty) {
+    int size = type_sizeof(ty);
+
+    printf("  pop rax\n");
+    if (size == 1) {
+        printf("  movsx rax, BYTE PTR [rax]\n");
+    } else if (size == 4) {
+        printf("  movsxd rax, DWORD PTR [rax]\n");
+    } else {
+        printf("  mov rax, [rax]\n");
+    }
+    printf("  push rax\n");
+}
+
+void codegen_deref_expr(CodeGen* g, AstNode* ast, GenMode gen_mode) {
+    codegen_expr(g, ast->node_operand, GenMode_rval);
+    if (gen_mode == GenMode_rval) {
+        codegen_lval2rval(ast->node_operand->ty->to);
+    }
+}
+
+void codegen_logical_expr(CodeGen* g, AstNode* ast) {
+    int label = codegen_new_label(g);
+
+    if (ast->node_op == TokenKind_andand) {
+        codegen_expr(g, ast->node_lhs, GenMode_rval);
+        printf("  pop rax\n");
+        printf("  cmp rax, 0\n");
+        printf("  je .Lelse%d\n", label);
+        codegen_expr(g, ast->node_rhs, GenMode_rval);
+        printf("  jmp .Lend%d\n", label);
+        printf(".Lelse%d:\n", label);
+        printf("  push 0\n");
+        printf(".Lend%d:\n", label);
+    } else {
+        codegen_expr(g, ast->node_lhs, GenMode_rval);
+        printf("  pop rax\n");
+        printf("  cmp rax, 0\n");
+        printf("  je .Lelse%d\n", label);
+        printf("  push 1\n");
+        printf("  jmp .Lend%d\n", label);
+        printf(".Lelse%d:\n", label);
+        codegen_expr(g, ast->node_rhs, GenMode_rval);
+        printf(".Lend%d:\n", label);
+    }
+}
+
+void codegen_binary_expr(CodeGen* g, AstNode* ast, GenMode gen_mode) {
+    codegen_expr(g, ast->node_lhs, gen_mode);
+    codegen_expr(g, ast->node_rhs, gen_mode);
+    printf("  pop rdi\n");
+    printf("  pop rax\n");
+    if (ast->node_op == TokenKind_plus) {
+        printf("  add rax, rdi\n");
+    } else if (ast->node_op == TokenKind_minus) {
+        printf("  sub rax, rdi\n");
+    } else if (ast->node_op == TokenKind_star) {
+        printf("  imul rax, rdi\n");
+    } else if (ast->node_op == TokenKind_slash) {
+        printf("  cqo\n");
+        printf("  idiv rdi\n");
+    } else if (ast->node_op == TokenKind_percent) {
+        printf("  cqo\n");
+        printf("  idiv rdi\n");
+        printf("  mov rax, rdx\n");
+    } else if (ast->node_op == TokenKind_eq) {
+        printf("  cmp rax, rdi\n");
+        printf("  sete al\n");
+        printf("  movzb rax, al\n");
+    } else if (ast->node_op == TokenKind_ne) {
+        printf("  cmp rax, rdi\n");
+        printf("  setne al\n");
+        printf("  movzb rax, al\n");
+    } else if (ast->node_op == TokenKind_lt) {
+        printf("  cmp rax, rdi\n");
+        printf("  setl al\n");
+        printf("  movzb rax, al\n");
+    } else if (ast->node_op == TokenKind_le) {
+        printf("  cmp rax, rdi\n");
+        printf("  setle al\n");
+        printf("  movzb rax, al\n");
+    } else {
+        unreachable();
+    }
+    printf("  push rax\n");
+}
+
+void codegen_assign_expr(CodeGen* g, AstNode* ast) {
+    codegen_expr(g, ast->node_lhs, GenMode_lval);
+    codegen_expr(g, ast->node_rhs, GenMode_rval);
+    if (ast->node_op == TokenKind_assign) {
+    } else if (ast->node_op == TokenKind_assign_add) {
+        printf("  pop rdi\n");
+        printf("  push [rsp]\n");
+        codegen_lval2rval(ast->node_lhs->ty);
+        printf("  pop rax\n");
+        printf("  add rax, rdi\n");
+        printf("  push rax\n");
+    } else if (ast->node_op == TokenKind_assign_sub) {
+        printf("  pop rdi\n");
+        printf("  push [rsp]\n");
+        codegen_lval2rval(ast->node_lhs->ty);
+        printf("  pop rax\n");
+        printf("  sub rax, rdi\n");
+        printf("  push rax\n");
+    } else {
+        unreachable();
+    }
+    printf("  pop rdi\n");
+    printf("  pop rax\n");
+    if (type_sizeof(ast->node_lhs->ty) == 1) {
+        printf("  mov BYTE PTR [rax], dil\n");
+    } else if (type_sizeof(ast->node_lhs->ty) == 4) {
+        printf("  mov DWORD PTR [rax], edi\n");
+    } else {
+        printf("  mov [rax], rdi\n");
+    }
+    printf("  push rdi\n");
+}
+
+void codegen_func_call(CodeGen* g, AstNode* ast) {
+    String* func_name = &ast->name;
+    AstNode* args = ast->node_args;
+    int i;
+    for (i = 0; i < args->node_len; ++i) {
+        AstNode* arg = args->node_items + i;
+        codegen_expr(g, arg, GenMode_rval);
+    }
+    for (i = args->node_len - 1; i >= 0; --i) {
+        printf("  pop %s\n", param_reg(i));
+    }
+
+    int label = codegen_new_label(g);
+
+    printf("  mov rax, rsp\n");
+    printf("  and rax, 15\n");
+    printf("  cmp rax, 0\n");
+    printf("  je .Laligned%d\n", label);
+
+    printf("  mov rax, 0\n");
+    printf("  sub rsp, 8\n");
+    printf("  call %.*s\n", func_name->len, func_name->data);
+    printf("  add rsp, 8\n");
+    printf("  push rax\n");
+
+    printf("  jmp .Lend%d\n", label);
+    printf(".Laligned%d:\n", label);
+
+    printf("  mov rax, 0\n");
+    printf("  call %.*s\n", func_name->len, func_name->data);
+    printf("  push rax\n");
+
+    printf(".Lend%d:\n", label);
+}
+
+void codegen_lvar(CodeGen* g, AstNode* ast, GenMode gen_mode) {
+    int offset = 8 + ast->node_idx * 8;
+    printf("  mov rax, rbp\n");
+    printf("  sub rax, %d\n", offset);
+    printf("  push rax\n");
+    if (gen_mode == GenMode_rval) {
+        codegen_lval2rval(ast->ty);
+    }
+}
+
+void codegen_gvar(CodeGen* g, AstNode* ast, GenMode gen_mode) {
+    if (gen_mode == GenMode_lval) {
+        fatal_error("unimplemented");
+    }
+    if (ast->ty->kind != TypeKind_ptr) {
+        fatal_error("unimplemented");
+    }
+    printf("  mov rax, QWORD PTR %.*s[rip]\n", ast->name.len, ast->name.data);
+    printf("  push rax\n");
+}
+
+void codegen_expr(CodeGen* g, AstNode* ast, GenMode gen_mode) {
+    if (ast->kind == AstNodeKind_int_expr) {
+        codegen_int_expr(g, ast);
+    } else if (ast->kind == AstNodeKind_str_expr) {
+        codegen_str_expr(g, ast);
+    } else if (ast->kind == AstNodeKind_unary_expr) {
+        codegen_unary_expr(g, ast);
+    } else if (ast->kind == AstNodeKind_ref_expr) {
+        codegen_ref_expr(g, ast, gen_mode);
+    } else if (ast->kind == AstNodeKind_deref_expr) {
+        codegen_deref_expr(g, ast, gen_mode);
+    } else if (ast->kind == AstNodeKind_binary_expr) {
+        codegen_binary_expr(g, ast, gen_mode);
+    } else if (ast->kind == AstNodeKind_logical_expr) {
+        codegen_logical_expr(g, ast);
+    } else if (ast->kind == AstNodeKind_assign_expr) {
+        codegen_assign_expr(g, ast);
+    } else if (ast->kind == AstNodeKind_func_call) {
+        codegen_func_call(g, ast);
+    } else if (ast->kind == AstNodeKind_lvar) {
+        codegen_lvar(g, ast, gen_mode);
+    } else if (ast->kind == AstNodeKind_gvar) {
+        codegen_gvar(g, ast, gen_mode);
+    } else {
+        unreachable();
+    }
+}
+
+void codegen_return_stmt(CodeGen* g, AstNode* ast) {
+    if (ast->node_expr) {
+        codegen_expr(g, ast->node_expr, GenMode_rval);
+        printf("  pop rax\n");
+    }
+    codegen_func_epilogue(g, ast);
+}
+
+void codegen_if_stmt(CodeGen* g, AstNode* ast) {
+    int label = codegen_new_label(g);
+
+    codegen_expr(g, ast->node_cond, GenMode_rval);
+    printf("  pop rax\n");
+    printf("  cmp rax, 0\n");
+    printf("  je .Lelse%d\n", label);
+    codegen_stmt(g, ast->node_then);
+    printf("  jmp .Lend%d\n", label);
+    printf(".Lelse%d:\n", label);
+    if (ast->node_else) {
+        codegen_stmt(g, ast->node_else);
+    }
+    printf(".Lend%d:\n", label);
+}
+
+void codegen_for_stmt(CodeGen* g, AstNode* ast) {
+    int label = codegen_new_label(g);
+    ++g->loop_labels;
+    *g->loop_labels = label;
+
+    if (ast->node_init) {
+        codegen_expr(g, ast->node_init, GenMode_rval);
+        printf("  pop rax\n");
+    }
+    printf(".Lbegin%d:\n", label);
+    codegen_expr(g, ast->node_cond, GenMode_rval);
+    printf("  pop rax\n");
+    printf("  cmp rax, 0\n");
+    printf("  je .Lend%d\n", label);
+    codegen_stmt(g, ast->node_body);
+    printf(".Lcontinue%d:\n", label);
+    if (ast->node_update) {
+        codegen_expr(g, ast->node_update, GenMode_rval);
+        printf("  pop rax\n");
+    }
+    printf("  jmp .Lbegin%d\n", label);
+    printf(".Lend%d:\n", label);
+
+    --g->loop_labels;
+}
+
+void codegen_do_while_stmt(CodeGen* g, AstNode* ast) {
+    int label = codegen_new_label(g);
+    ++g->loop_labels;
+    *g->loop_labels = label;
+
+    printf(".Lbegin%d:\n", label);
+    codegen_stmt(g, ast->node_body);
+    printf(".Lcontinue%d:\n", label);
+    codegen_expr(g, ast->node_cond, GenMode_rval);
+    printf("  pop rax\n");
+    printf("  cmp rax, 0\n");
+    printf("  je .Lend%d\n", label);
+    printf("  jmp .Lbegin%d\n", label);
+    printf(".Lend%d:\n", label);
+
+    --g->loop_labels;
+}
+
+void codegen_break_stmt(CodeGen* g, AstNode* ast) {
+    int label = *g->loop_labels;
+    printf("  jmp .Lend%d\n", label);
+}
+
+void codegen_continue_stmt(CodeGen* g, AstNode* ast) {
+    int label = *g->loop_labels;
+    printf("  jmp .Lcontinue%d\n", label);
+}
+
+void codegen_expr_stmt(CodeGen* g, AstNode* ast) {
+    codegen_expr(g, ast->node_expr, GenMode_rval);
+    printf("  pop rax\n");
+}
+
+void codegen_var_decl(CodeGen* g, AstNode* ast) {
+}
+
+void codegen_block_stmt(CodeGen* g, AstNode* ast) {
+    int i;
+    for (i = 0; i < ast->node_len; ++i) {
+        AstNode* stmt = ast->node_items + i;
+        codegen_stmt(g, stmt);
+    }
+}
+
+void codegen_stmt(CodeGen* g, AstNode* ast) {
+    if (ast->kind == AstNodeKind_list) {
+        codegen_block_stmt(g, ast);
+    } else if (ast->kind == AstNodeKind_return_stmt) {
+        codegen_return_stmt(g, ast);
+    } else if (ast->kind == AstNodeKind_if_stmt) {
+        codegen_if_stmt(g, ast);
+    } else if (ast->kind == AstNodeKind_for_stmt) {
+        codegen_for_stmt(g, ast);
+    } else if (ast->kind == AstNodeKind_do_while_stmt) {
+        codegen_do_while_stmt(g, ast);
+    } else if (ast->kind == AstNodeKind_break_stmt) {
+        codegen_break_stmt(g, ast);
+    } else if (ast->kind == AstNodeKind_continue_stmt) {
+        codegen_continue_stmt(g, ast);
+    } else if (ast->kind == AstNodeKind_expr_stmt) {
+        codegen_expr_stmt(g, ast);
+    } else if (ast->kind == AstNodeKind_lvar_decl) {
+        codegen_var_decl(g, ast);
+    } else {
+        unreachable();
+    }
+}
+
+void codegen_func(CodeGen* g, AstNode* ast) {
+    printf("%.*s:\n", ast->name.len, ast->name.data);
+
+    codegen_func_prologue(g, ast);
+    codegen_stmt(g, ast->node_body);
+    codegen_func_epilogue(g, ast);
+
+    printf("\n");
+}
+
+void codegen(Program* prog) {
+    CodeGen* g = codegen_new();
+
+    printf(".intel_syntax noprefix\n\n");
+
+    int i;
+    for (i = 0; prog->str_literals[i]; ++i) {
+        printf(".Lstr__%d:\n", i + 1);
+        printf("  .string \"%s\"\n\n", prog->str_literals[i]);
+    }
+
+    printf(".globl main\n\n");
+
+    for (i = 0; i < prog->funcs->node_len; ++i) {
+        AstNode* func = prog->funcs->node_items + i;
+        codegen_func(g, func);
+    }
+}
diff --git a/common.c b/common.c
new file mode 100644
index 0000000..fcc0790
--- /dev/null
+++ b/common.c
@@ -0,0 +1,41 @@
+void fatal_error(const char* msg) {
+    fprintf(stderr, "%s\n", msg);
+    exit(1);
+}
+
+void unreachable() {
+    fatal_error("unreachable");
+}
+
+char* read_all(FILE* in) {
+    char* buf = calloc(1024 * 1024, sizeof(char));
+    char* cur = buf;
+    char* tmp = calloc(1024, sizeof(char));
+    while (fgets(tmp, 1024, in)) {
+        size_t len = strlen(tmp);
+        memcpy(cur, tmp, len);
+        cur += len;
+    }
+    return buf;
+}
+
+struct String {
+    char* data;
+    size_t len;
+};
+typedef struct String String;
+
+char* string_to_cstr(const String* s) {
+    char* buf = calloc(s->len + 1, sizeof(char));
+    memcpy(buf, s->data, s->len);
+    return buf;
+}
+
+int string_equals(const String* s1, const String* s2) {
+    return s1->len == s2->len && strncmp(s1->data, s2->data, s1->len) == 0;
+}
+
+int string_equals_cstr(const String* s1, const char* s2) {
+    size_t s2_len = strlen(s2);
+    return s1->len == s2_len && strncmp(s1->data, s2, s1->len) == 0;
+}
diff --git a/main.c b/main.c
index 463d4a1..e9a4fa0 100644
--- a/main.c
+++ b/main.c
@@ -1,2671 +1,14 @@
-typedef long size_t;
-
-struct FILE;
-typedef struct FILE FILE;
-
-extern FILE* stdin;
-extern FILE* stdout;
-extern FILE* stderr;
-
-int atoi(const char*);
-void* calloc(size_t, size_t);
-void exit(int);
-int fclose(FILE*);
-int fprintf(FILE*, const char*, ...);
-char* fgets(char*, int, FILE*);
-FILE* fopen(const char*, const char*);
-int getchar(void);
-int isalnum(int);
-int isalpha(int);
-int isdigit(int);
-int isspace(int);
-void* memcpy(void*, void*, size_t);
-void* memmove(void*, void*, size_t);
-int printf(const char*, ...);
-int sprintf(char*, const char*, ...);
-int strcmp(const char*, const char*);
-size_t strlen(const char*);
-int strncmp(const char*, const char*, size_t);
-char* strstr(const char*, const char*);
-
-#define NULL 0
-
-void fatal_error(const char* msg) {
-    fprintf(stderr, "%s\n", msg);
-    exit(1);
-}
-
-void unreachable() {
-    fatal_error("unreachable");
-}
-
-char* read_all(FILE* in) {
-    char* buf = calloc(1024 * 1024, sizeof(char));
-    char* cur = buf;
-    char* tmp = calloc(1024, sizeof(char));
-    while (fgets(tmp, 1024, in)) {
-        size_t len = strlen(tmp);
-        memcpy(cur, tmp, len);
-        cur += len;
-    }
-    return buf;
-}
-
-struct String {
-    char* data;
-    size_t len;
-};
-typedef struct String String;
-
-char* string_to_cstr(const String* s) {
-    char* buf = calloc(s->len + 1, sizeof(char));
-    memcpy(buf, s->data, s->len);
-    return buf;
-}
-
-int string_equals(const String* s1, const String* s2) {
-    return s1->len == s2->len && strncmp(s1->data, s2->data, s1->len) == 0;
-}
-
-int string_equals_cstr(const String* s1, const char* s2) {
-    size_t s2_len = strlen(s2);
-    return s1->len == s2_len && strncmp(s1->data, s2, s1->len) == 0;
-}
-
-enum PpTokenKind {
-    PpTokenKind_eof,
-
-    PpTokenKind_header_name,
-    PpTokenKind_identifier,
-    PpTokenKind_pp_number,
-    PpTokenKind_character_constant,
-    PpTokenKind_string_literal,
-    PpTokenKind_punctuator,
-    PpTokenKind_other,
-    PpTokenKind_whitespace,
-};
-typedef enum PpTokenKind PpTokenKind;
-
-struct PpToken {
-    PpTokenKind kind;
-    String raw;
-};
-typedef struct PpToken PpToken;
-
-struct PpDefine {
-    String name;
-    PpToken* tokens;
-};
-typedef struct PpDefine PpDefine;
-
-struct Preprocessor {
-    char* src;
-    int pos;
-    PpToken* pp_tokens;
-    int n_pp_tokens;
-    PpDefine* pp_defines;
-    int n_pp_defines;
-    int include_depth;
-};
-typedef struct Preprocessor Preprocessor;
-
-PpToken* do_preprocess(char* src, int depth);
-
-Preprocessor* preprocessor_new(char* src, int include_depth) {
-    if (include_depth >= 32) {
-        fatal_error("include depth limit exceeded");
-    }
-
-    Preprocessor* pp = calloc(1, sizeof(Preprocessor));
-    pp->src = src;
-    pp->pp_tokens = calloc(1024 * 1024, sizeof(PpToken));
-    pp->pp_defines = calloc(1024, sizeof(PpDefine));
-    pp->include_depth = include_depth;
-
-    return pp;
-}
-
-int find_pp_define(Preprocessor* pp, String* name) {
-    int i;
-    for (i = 0; i < pp->n_pp_defines; ++i) {
-        if (string_equals(&pp->pp_defines[i].name, name)) {
-            return i;
-        }
-    }
-    return -1;
-}
-
-void pp_tokenize_all(Preprocessor* pp) {
-    char* buf;
-    int ch;
-    int start;
-    while (pp->src[pp->pos]) {
-        PpToken* tok = pp->pp_tokens + pp->n_pp_tokens;
-        char c = pp->src[pp->pos];
-        ++pp->pos;
-        if (c == '(') {
-            tok->kind = PpTokenKind_punctuator;
-            tok->raw.len = 1;
-            tok->raw.data = pp->src + pp->pos - tok->raw.len;
-        } else if (c == ')') {
-            tok->kind = PpTokenKind_punctuator;
-            tok->raw.len = 1;
-            tok->raw.data = pp->src + pp->pos - tok->raw.len;
-        } else if (c == '{') {
-            tok->kind = PpTokenKind_punctuator;
-            tok->raw.len = 1;
-            tok->raw.data = pp->src + pp->pos - tok->raw.len;
-        } else if (c == '}') {
-            tok->kind = PpTokenKind_punctuator;
-            tok->raw.len = 1;
-            tok->raw.data = pp->src + pp->pos - tok->raw.len;
-        } else if (c == '[') {
-            tok->kind = PpTokenKind_punctuator;
-            tok->raw.len = 1;
-            tok->raw.data = pp->src + pp->pos - tok->raw.len;
-        } else if (c == ']') {
-            tok->kind = PpTokenKind_punctuator;
-            tok->raw.len = 1;
-            tok->raw.data = pp->src + pp->pos - tok->raw.len;
-        } else if (c == ',') {
-            tok->kind = PpTokenKind_punctuator;
-            tok->raw.len = 1;
-            tok->raw.data = pp->src + pp->pos - tok->raw.len;
-        } else if (c == ';') {
-            tok->kind = PpTokenKind_punctuator;
-            tok->raw.len = 1;
-            tok->raw.data = pp->src + pp->pos - tok->raw.len;
-        } else if (c == '+') {
-            if (pp->src[pp->pos] == '=') {
-                ++pp->pos;
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 2;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            } else if (pp->src[pp->pos] == '+') {
-                ++pp->pos;
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 2;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            } else {
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 1;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            }
-        } else if (c == '|') {
-            ++pp->pos;
-            tok->kind = PpTokenKind_punctuator;
-            tok->raw.len = 2;
-            tok->raw.data = pp->src + pp->pos - tok->raw.len;
-        } else if (c == '&') {
-            if (pp->src[pp->pos] == '&') {
-                ++pp->pos;
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 2;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            } else {
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 1;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            }
-        } else if (c == '-') {
-            if (pp->src[pp->pos] == '>') {
-                ++pp->pos;
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 2;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            } else if (pp->src[pp->pos] == '=') {
-                ++pp->pos;
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 2;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            } else if (pp->src[pp->pos] == '-') {
-                ++pp->pos;
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 2;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            } else {
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 1;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            }
-        } else if (c == '*') {
-            tok->kind = PpTokenKind_punctuator;
-            tok->raw.len = 1;
-            tok->raw.data = pp->src + pp->pos - tok->raw.len;
-        } else if (c == '/') {
-            if (pp->src[pp->pos] == '/') {
-                start = pp->pos - 1;
-                ++pp->pos;
-                while (pp->src[pp->pos] && pp->src[pp->pos] != '\n' && pp->src[pp->pos] != '\r') {
-                    ++pp->pos;
-                }
-                tok->kind = PpTokenKind_whitespace;
-                tok->raw.len = pp->pos - start;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            } else if (pp->src[pp->pos] == '*') {
-                fatal_error("unimplemented");
-            } else {
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 1;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            }
-        } else if (c == '%') {
-            tok->kind = PpTokenKind_punctuator;
-            tok->raw.len = 1;
-            tok->raw.data = pp->src + pp->pos - tok->raw.len;
-        } else if (c == '.') {
-            if (pp->src[pp->pos] == '.') {
-                ++pp->pos;
-                if (pp->src[pp->pos] == '.') {
-                    ++pp->pos;
-                    tok->kind = PpTokenKind_punctuator;
-                    tok->raw.len = 3;
-                    tok->raw.data = pp->src + pp->pos - tok->raw.len;
-                } else {
-                    --pp->pos;
-                    tok->kind = PpTokenKind_punctuator;
-                    tok->raw.len = 1;
-                    tok->raw.data = pp->src + pp->pos - tok->raw.len;
-                }
-            } else {
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 1;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            }
-        } else if (c == '!') {
-            if (pp->src[pp->pos] == '=') {
-                ++pp->pos;
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 2;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            } else {
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 1;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            }
-        } else if (c == '=') {
-            if (pp->src[pp->pos] == '=') {
-                ++pp->pos;
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 2;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            } else {
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 1;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            }
-        } else if (c == '<') {
-            if (pp->src[pp->pos] == '=') {
-                ++pp->pos;
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 2;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            } else {
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 1;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            }
-        } else if (c == '>') {
-            if (pp->src[pp->pos] == '=') {
-                ++pp->pos;
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 2;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            } else {
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 1;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            }
-        } else if (c == '#') {
-            if (pp->src[pp->pos] == '#') {
-                ++pp->pos;
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 2;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            } else {
-                tok->kind = PpTokenKind_punctuator;
-                tok->raw.len = 1;
-                tok->raw.data = pp->src + pp->pos - tok->raw.len;
-            }
-        } else if (c == '\'') {
-            start = pp->pos - 1;
-            if (pp->src[pp->pos] == '\\') {
-                ++pp->pos;
-            }
-            pp->pos += 2;
-            tok->kind = PpTokenKind_character_constant;
-            tok->raw.data = pp->src + start;
-            tok->raw.len = pp->pos - start;
-        } else if (c == '"') {
-            start = pp->pos - 1;
-            while (1) {
-                ch = pp->src[pp->pos];
-                if (ch == '\\') {
-                    ++pp->pos;
-                } else if (ch == '"') {
-                    break;
-                }
-                ++pp->pos;
-            }
-            ++pp->pos;
-            tok->kind = PpTokenKind_string_literal;
-            tok->raw.data = pp->src + start;
-            tok->raw.len = pp->pos - start;
-        } else if (isdigit(c)) {
-            --pp->pos;
-            start = pp->pos;
-            while (isdigit(pp->src[pp->pos])) {
-                ++pp->pos;
-            }
-            tok->kind = PpTokenKind_pp_number;
-            tok->raw.data = pp->src + start;
-            tok->raw.len = pp->pos - start;
-        } else if (isalpha(c) || c == '_') {
-            --pp->pos;
-            start = pp->pos;
-            while (isalnum(pp->src[pp->pos]) || pp->src[pp->pos] == '_') {
-                ++pp->pos;
-            }
-            tok->raw.data = pp->src + start;
-            tok->raw.len = pp->pos - start;
-            tok->kind = PpTokenKind_identifier;
-        } else if (isspace(c)) {
-            tok->raw.data = pp->src;
-            tok->raw.len = 1;
-            tok->kind = PpTokenKind_whitespace;
-        } else {
-            tok->raw.data = pp->src;
-            tok->raw.len = 1;
-            tok->kind = PpTokenKind_other;
-        }
-        ++pp->n_pp_tokens;
-    }
-}
-
-void process_pp_directives(Preprocessor* pp) {
-    PpToken* tok = pp->pp_tokens;
-    PpToken* define_dest;
-    while (tok->kind != PpTokenKind_eof) {
-        // TODO: check if the token is at the beginning of line.
-        // TODO: check if skipped whitespaces do not contain line breaks.
-        if (tok->kind == PpTokenKind_punctuator && string_equals_cstr(&tok->raw, "#")) {
-            PpToken* tok2 = tok + 1;
-            while (tok2->kind != PpTokenKind_eof && tok2->kind == PpTokenKind_whitespace)
-                ++tok2;
-            if (tok2->kind == PpTokenKind_identifier && string_equals_cstr(&tok2->raw, "define")) {
-                ++tok2;
-                while (tok2->kind != PpTokenKind_eof && tok2->kind == PpTokenKind_whitespace)
-                    ++tok2;
-                if (tok2->kind == PpTokenKind_identifier) {
-                    PpToken* define_name = tok2;
-                    ++tok2;
-                    while (tok2->kind != PpTokenKind_eof && tok2->kind == PpTokenKind_whitespace)
-                        ++tok2;
-                    if (tok2->kind == PpTokenKind_identifier || tok2->kind == PpTokenKind_pp_number) {
-                        define_dest = tok2;
-
-                        pp->pp_defines[pp->n_pp_defines].name.len = define_name->raw.len;
-                        pp->pp_defines[pp->n_pp_defines].name.data = define_name->raw.data;
-                        pp->pp_defines[pp->n_pp_defines].tokens = calloc(1, sizeof(PpToken));
-                        pp->pp_defines[pp->n_pp_defines].tokens[0].kind = define_dest->kind;
-                        pp->pp_defines[pp->n_pp_defines].tokens[0].raw.len = define_dest->raw.len;
-                        pp->pp_defines[pp->n_pp_defines].tokens[0].raw.data = define_dest->raw.data;
-                        ++pp->n_pp_defines;
-                    }
-                }
-                // Remove #define directive.
-                while (tok != tok2 + 1) {
-                    tok->kind = PpTokenKind_whitespace;
-                    tok->raw.len = 0;
-                    tok->raw.data = NULL;
-                    ++tok;
-                }
-            } else if (tok2->kind == PpTokenKind_identifier && string_equals_cstr(&tok2->raw, "include")) {
-                ++tok2;
-                while (tok2->kind != PpTokenKind_eof && tok2->kind == PpTokenKind_whitespace)
-                    ++tok2;
-                if (tok2->kind == PpTokenKind_string_literal) {
-                    // Process #include directive.
-                    PpToken* include_name = tok2;
-                    ++tok2;
-                    char* include_name_buf = calloc(include_name->raw.len - 2 + 1, sizeof(char));
-                    sprintf(include_name_buf, "%.*s", include_name->raw.len - 2, include_name->raw.data + 1);
-
-                    // Remove #include directive itself.
-                    while (tok != tok2 + 1) {
-                        tok->kind = PpTokenKind_whitespace;
-                        tok->raw.len = 0;
-                        tok->raw.data = NULL;
-                        ++tok;
-                    }
-
-                    // Read and preprocess included file.
-                    FILE* include_file = fopen(include_name_buf, "rb");
-                    if (include_file == NULL) {
-                        char* buf = calloc(1024, sizeof(char));
-                        sprintf(buf, "cannot open include file: %s", include_name_buf);
-                        fatal_error(buf);
-                    }
-                    char* include_source = read_all(include_file);
-                    fclose(include_file);
-
-                    PpToken* include_pp_tokens = do_preprocess(include_source, pp->include_depth + 1);
-
-                    // Insert preprocessed tokens into the current token stream.
-                    int n_include_pp_tokens = 0;
-                    while (include_pp_tokens[n_include_pp_tokens].kind != PpTokenKind_eof) {
-                        ++n_include_pp_tokens;
-                    }
-
-                    // Shift existing tokens to make room for include tokens
-                    int n_pp_tokens_after_include = pp->n_pp_tokens - (tok - pp->pp_tokens);
-
-                    memmove(tok + n_include_pp_tokens, tok, n_pp_tokens_after_include * sizeof(PpToken));
-
-                    // Copy include tokens into the current position
-                    memcpy(tok, include_pp_tokens, n_include_pp_tokens * sizeof(PpToken));
-
-                    pp->n_pp_tokens += n_include_pp_tokens;
-                }
-            }
-        } else if (tok->kind == PpTokenKind_identifier) {
-            int pp_define_idx = find_pp_define(pp, &tok->raw);
-            if (pp_define_idx != -1) {
-                define_dest = pp->pp_defines[pp_define_idx].tokens;
-                tok->kind = define_dest->kind;
-                tok->raw.data = define_dest->raw.data;
-                tok->raw.len = define_dest->raw.len;
-            }
-        }
-        ++tok;
-    }
-}
-
-PpToken* do_preprocess(char* src, int depth) {
-    Preprocessor* pp = preprocessor_new(src, depth);
-    pp_tokenize_all(pp);
-    process_pp_directives(pp);
-    return pp->pp_tokens;
-}
-
-PpToken* preprocess(char* src) {
-    return do_preprocess(src, 0);
-}
-
-enum TokenKind {
-    TokenKind_eof,
-
-    TokenKind_and,
-    TokenKind_andand,
-    TokenKind_arrow,
-    TokenKind_assign,
-    TokenKind_assign_add,
-    TokenKind_assign_sub,
-    TokenKind_brace_l,
-    TokenKind_brace_r,
-    TokenKind_bracket_l,
-    TokenKind_bracket_r,
-    TokenKind_comma,
-    TokenKind_dot,
-    TokenKind_ellipsis,
-    TokenKind_eq,
-    TokenKind_ge,
-    TokenKind_gt,
-    TokenKind_ident,
-    TokenKind_keyword_break,
-    TokenKind_keyword_char,
-    TokenKind_keyword_const,
-    TokenKind_keyword_continue,
-    TokenKind_keyword_do,
-    TokenKind_keyword_else,
-    TokenKind_keyword_enum,
-    TokenKind_keyword_extern,
-    TokenKind_keyword_for,
-    TokenKind_keyword_if,
-    TokenKind_keyword_int,
-    TokenKind_keyword_long,
-    TokenKind_keyword_return,
-    TokenKind_keyword_sizeof,
-    TokenKind_keyword_struct,
-    TokenKind_keyword_typeof,
-    TokenKind_keyword_void,
-    TokenKind_keyword_while,
-    TokenKind_le,
-    TokenKind_lt,
-    TokenKind_literal_int,
-    TokenKind_literal_str,
-    TokenKind_minus,
-    TokenKind_minusminus,
-    TokenKind_ne,
-    TokenKind_not,
-    TokenKind_oror,
-    TokenKind_paren_l,
-    TokenKind_paren_r,
-    TokenKind_percent,
-    TokenKind_plus,
-    TokenKind_plusplus,
-    TokenKind_semicolon,
-    TokenKind_slash,
-    TokenKind_star,
-};
-typedef enum TokenKind TokenKind;
-
-struct Token {
-    TokenKind kind;
-    String raw;
-};
-typedef struct Token Token;
-
-const char* token_kind_stringify(TokenKind k) {
-    if (k == TokenKind_eof)
-        return "<eof>";
-    else if (k == TokenKind_and)
-        return "&";
-    else if (k == TokenKind_andand)
-        return "&&";
-    else if (k == TokenKind_arrow)
-        return "->";
-    else if (k == TokenKind_assign)
-        return "=";
-    else if (k == TokenKind_assign_add)
-        return "+=";
-    else if (k == TokenKind_assign_sub)
-        return "-=";
-    else if (k == TokenKind_brace_l)
-        return "{";
-    else if (k == TokenKind_brace_r)
-        return "}";
-    else if (k == TokenKind_bracket_l)
-        return "[";
-    else if (k == TokenKind_bracket_r)
-        return "]";
-    else if (k == TokenKind_comma)
-        return ",";
-    else if (k == TokenKind_dot)
-        return ".";
-    else if (k == TokenKind_ellipsis)
-        return "...";
-    else if (k == TokenKind_eq)
-        return "==";
-    else if (k == TokenKind_ge)
-        return ">=";
-    else if (k == TokenKind_gt)
-        return ">";
-    else if (k == TokenKind_ident)
-        return "<identifier>";
-    else if (k == TokenKind_keyword_break)
-        return "break";
-    else if (k == TokenKind_keyword_char)
-        return "char";
-    else if (k == TokenKind_keyword_const)
-        return "const";
-    else if (k == TokenKind_keyword_continue)
-        return "continue";
-    else if (k == TokenKind_keyword_do)
-        return "do";
-    else if (k == TokenKind_keyword_else)
-        return "else";
-    else if (k == TokenKind_keyword_enum)
-        return "enum";
-    else if (k == TokenKind_keyword_extern)
-        return "extern";
-    else if (k == TokenKind_keyword_for)
-        return "for";
-    else if (k == TokenKind_keyword_if)
-        return "if";
-    else if (k == TokenKind_keyword_int)
-        return "int";
-    else if (k == TokenKind_keyword_long)
-        return "long";
-    else if (k == TokenKind_keyword_return)
-        return "return";
-    else if (k == TokenKind_keyword_sizeof)
-        return "sizeof";
-    else if (k == TokenKind_keyword_struct)
-        return "struct";
-    else if (k == TokenKind_keyword_typeof)
-        return "typeof";
-    else if (k == TokenKind_keyword_void)
-        return "void";
-    else if (k == TokenKind_keyword_while)
-        return "while";
-    else if (k == TokenKind_le)
-        return "le";
-    else if (k == TokenKind_lt)
-        return "lt";
-    else if (k == TokenKind_literal_int)
-        return "<integer>";
-    else if (k == TokenKind_literal_str)
-        return "<string>";
-    else if (k == TokenKind_minus)
-        return "-";
-    else if (k == TokenKind_minusminus)
-        return "--";
-    else if (k == TokenKind_ne)
-        return "!=";
-    else if (k == TokenKind_not)
-        return "!";
-    else if (k == TokenKind_oror)
-        return "||";
-    else if (k == TokenKind_paren_l)
-        return "(";
-    else if (k == TokenKind_paren_r)
-        return ")";
-    else if (k == TokenKind_percent)
-        return "%";
-    else if (k == TokenKind_plus)
-        return "+";
-    else if (k == TokenKind_plusplus)
-        return "++";
-    else if (k == TokenKind_semicolon)
-        return ";";
-    else if (k == TokenKind_slash)
-        return "/";
-    else if (k == TokenKind_star)
-        return "*";
-    else
-        unreachable();
-}
-
-const char* token_stringify(Token* t) {
-    TokenKind k = t->kind;
-    if (k == TokenKind_ident || k == TokenKind_literal_int || k == TokenKind_literal_str) {
-        char* buf = calloc(t->raw.len + 1, sizeof(char));
-        sprintf(buf, "%.*s (%s)", t->raw.len, t->raw.data, token_kind_stringify(k));
-        return buf;
-    } else {
-        return token_kind_stringify(k);
-    }
-}
-
-struct Lexer {
-    PpToken* src;
-    int pos;
-    Token* tokens;
-    int n_tokens;
-};
-typedef struct Lexer Lexer;
-
-Lexer* lexer_new(PpToken* pp_tokens) {
-    Lexer* l = calloc(1, sizeof(Lexer));
-    l->src = pp_tokens;
-    l->tokens = calloc(1024 * 1024, sizeof(Token));
-    return l;
-}
-
-void tokenize_all(Lexer* l) {
-    char* buf;
-    int ch;
-    int start;
-    while (l->src[l->pos].kind != PpTokenKind_eof) {
-        PpToken* pp_tok = l->src + l->pos;
-        Token* tok = l->tokens + l->n_tokens;
-        PpTokenKind k = pp_tok->kind;
-        ++l->pos;
-        if (k == PpTokenKind_header_name) {
-            fatal_error("not implemented yet");
-        } else if (k == PpTokenKind_identifier) {
-            if (string_equals_cstr(&pp_tok->raw, "break")) {
-                tok->kind = TokenKind_keyword_break;
-            } else if (string_equals_cstr(&pp_tok->raw, "char")) {
-                tok->kind = TokenKind_keyword_char;
-            } else if (string_equals_cstr(&pp_tok->raw, "const")) {
-                tok->kind = TokenKind_keyword_const;
-            } else if (string_equals_cstr(&pp_tok->raw, "continue")) {
-                tok->kind = TokenKind_keyword_continue;
-            } else if (string_equals_cstr(&pp_tok->raw, "do")) {
-                tok->kind = TokenKind_keyword_do;
-            } else if (string_equals_cstr(&pp_tok->raw, "else")) {
-                tok->kind = TokenKind_keyword_else;
-            } else if (string_equals_cstr(&pp_tok->raw, "enum")) {
-                tok->kind = TokenKind_keyword_enum;
-            } else if (string_equals_cstr(&pp_tok->raw, "extern")) {
-                tok->kind = TokenKind_keyword_extern;
-            } else if (string_equals_cstr(&pp_tok->raw, "for")) {
-                tok->kind = TokenKind_keyword_for;
-            } else if (string_equals_cstr(&pp_tok->raw, "if")) {
-                tok->kind = TokenKind_keyword_if;
-            } else if (string_equals_cstr(&pp_tok->raw, "int")) {
-                tok->kind = TokenKind_keyword_int;
-            } else if (string_equals_cstr(&pp_tok->raw, "long")) {
-                tok->kind = TokenKind_keyword_long;
-            } else if (string_equals_cstr(&pp_tok->raw, "return")) {
-                tok->kind = TokenKind_keyword_return;
-            } else if (string_equals_cstr(&pp_tok->raw, "sizeof")) {
-                tok->kind = TokenKind_keyword_sizeof;
-            } else if (string_equals_cstr(&pp_tok->raw, "struct")) {
-                tok->kind = TokenKind_keyword_struct;
-            } else if (string_equals_cstr(&pp_tok->raw, "typedef")) {
-                tok->kind = TokenKind_keyword_typeof;
-            } else if (string_equals_cstr(&pp_tok->raw, "void")) {
-                tok->kind = TokenKind_keyword_void;
-            } else if (string_equals_cstr(&pp_tok->raw, "while")) {
-                tok->kind = TokenKind_keyword_while;
-            } else {
-                tok->kind = TokenKind_ident;
-            }
-            tok->raw.data = pp_tok->raw.data;
-            tok->raw.len = pp_tok->raw.len;
-        } else if (k == PpTokenKind_pp_number) {
-            tok->kind = TokenKind_literal_int;
-            tok->raw.data = pp_tok->raw.data;
-            tok->raw.len = pp_tok->raw.len;
-        } else if (k == PpTokenKind_character_constant) {
-            tok->kind = TokenKind_literal_int;
-            ch = pp_tok->raw.data[1];
-            if (ch == '\\') {
-                ch = pp_tok->raw.data[2];
-                if (ch == 'a') {
-                    ch = '\a';
-                } else if (ch == 'b') {
-                    ch = '\b';
-                } else if (ch == 'f') {
-                    ch = '\f';
-                } else if (ch == 'n') {
-                    ch = '\n';
-                } else if (ch == 'r') {
-                    ch = '\r';
-                } else if (ch == 't') {
-                    ch = '\t';
-                } else if (ch == 'v') {
-                    ch = '\v';
-                }
-            }
-            buf = calloc(4, sizeof(char));
-            sprintf(buf, "%d", ch);
-            tok->raw.data = buf;
-            tok->raw.len = strlen(buf);
-        } else if (k == PpTokenKind_string_literal) {
-            tok->kind = TokenKind_literal_str;
-            tok->raw.data = pp_tok->raw.data + 1;
-            tok->raw.len = pp_tok->raw.len - 2;
-        } else if (k == PpTokenKind_punctuator || k == PpTokenKind_other) {
-            if (string_equals_cstr(&pp_tok->raw, "(")) {
-                tok->kind = TokenKind_paren_l;
-            } else if (string_equals_cstr(&pp_tok->raw, ")")) {
-                tok->kind = TokenKind_paren_r;
-            } else if (string_equals_cstr(&pp_tok->raw, "{")) {
-                tok->kind = TokenKind_brace_l;
-            } else if (string_equals_cstr(&pp_tok->raw, "}")) {
-                tok->kind = TokenKind_brace_r;
-            } else if (string_equals_cstr(&pp_tok->raw, "[")) {
-                tok->kind = TokenKind_bracket_l;
-            } else if (string_equals_cstr(&pp_tok->raw, "]")) {
-                tok->kind = TokenKind_bracket_r;
-            } else if (string_equals_cstr(&pp_tok->raw, ",")) {
-                tok->kind = TokenKind_comma;
-            } else if (string_equals_cstr(&pp_tok->raw, ";")) {
-                tok->kind = TokenKind_semicolon;
-            } else if (string_equals_cstr(&pp_tok->raw, "+=")) {
-                tok->kind = TokenKind_assign_add;
-            } else if (string_equals_cstr(&pp_tok->raw, "++")) {
-                tok->kind = TokenKind_plusplus;
-            } else if (string_equals_cstr(&pp_tok->raw, "+")) {
-                tok->kind = TokenKind_plus;
-            } else if (string_equals_cstr(&pp_tok->raw, "||")) {
-                tok->kind = TokenKind_oror;
-            } else if (string_equals_cstr(&pp_tok->raw, "&&")) {
-                tok->kind = TokenKind_andand;
-            } else if (string_equals_cstr(&pp_tok->raw, "&")) {
-                tok->kind = TokenKind_and;
-            } else if (string_equals_cstr(&pp_tok->raw, "->")) {
-                tok->kind = TokenKind_arrow;
-            } else if (string_equals_cstr(&pp_tok->raw, "-=")) {
-                tok->kind = TokenKind_assign_sub;
-            } else if (string_equals_cstr(&pp_tok->raw, "--")) {
-                tok->kind = TokenKind_minusminus;
-            } else if (string_equals_cstr(&pp_tok->raw, "-")) {
-                tok->kind = TokenKind_minus;
-            } else if (string_equals_cstr(&pp_tok->raw, "*")) {
-                tok->kind = TokenKind_star;
-            } else if (string_equals_cstr(&pp_tok->raw, "/")) {
-                tok->kind = TokenKind_slash;
-            } else if (string_equals_cstr(&pp_tok->raw, "%")) {
-                tok->kind = TokenKind_percent;
-            } else if (string_equals_cstr(&pp_tok->raw, "...")) {
-                tok->kind = TokenKind_ellipsis;
-            } else if (string_equals_cstr(&pp_tok->raw, ".")) {
-                tok->kind = TokenKind_dot;
-            } else if (string_equals_cstr(&pp_tok->raw, "!=")) {
-                tok->kind = TokenKind_ne;
-            } else if (string_equals_cstr(&pp_tok->raw, "!")) {
-                tok->kind = TokenKind_not;
-            } else if (string_equals_cstr(&pp_tok->raw, "==")) {
-                tok->kind = TokenKind_eq;
-            } else if (string_equals_cstr(&pp_tok->raw, "=")) {
-                tok->kind = TokenKind_assign;
-            } else if (string_equals_cstr(&pp_tok->raw, "<=")) {
-                tok->kind = TokenKind_le;
-            } else if (string_equals_cstr(&pp_tok->raw, "<")) {
-                tok->kind = TokenKind_lt;
-            } else if (string_equals_cstr(&pp_tok->raw, ">=")) {
-                tok->kind = TokenKind_ge;
-            } else if (string_equals_cstr(&pp_tok->raw, ">")) {
-                tok->kind = TokenKind_gt;
-            } else {
-                sprintf(buf, "unknown token: %.*s", pp_tok->raw.len, pp_tok->raw.data);
-                fatal_error(buf);
-            }
-            tok->raw.data = pp_tok->raw.data;
-            tok->raw.len = pp_tok->raw.len;
-        } else if (k == PpTokenKind_whitespace) {
-            continue;
-        }
-        ++l->n_tokens;
-    }
-}
-
-Token* tokenize(PpToken* pp_tokens) {
-    Lexer* l = lexer_new(pp_tokens);
-    tokenize_all(l);
-    return l->tokens;
-}
-
-enum TypeKind {
-    TypeKind_unknown,
-
-    TypeKind_char,
-    TypeKind_int,
-    TypeKind_long,
-    TypeKind_void,
-    TypeKind_ptr,
-    TypeKind_enum,
-    TypeKind_struct,
-};
-typedef enum TypeKind TypeKind;
-
-struct AstNode;
-
-struct Type {
-    TypeKind kind;
-    struct Type* to;
-    struct AstNode* def;
-};
-typedef struct Type Type;
-
-Type* type_new(TypeKind kind) {
-    Type* ty = calloc(1, sizeof(Type));
-    ty->kind = kind;
-    return ty;
-}
-
-Type* type_new_ptr(Type* to) {
-    Type* ty = calloc(1, sizeof(Type));
-    ty->kind = TypeKind_ptr;
-    ty->to = to;
-    return ty;
-}
-
-int type_is_unsized(Type* ty) {
-    return ty->kind != TypeKind_void;
-}
-
-int type_sizeof_struct(Type* ty);
-int type_alignof_struct(Type* ty);
-int type_offsetof(Type* ty, const String* name);
-Type* type_member_typeof(Type* ty, const String* name);
-
-int type_sizeof(Type* ty) {
-    if (!type_is_unsized(ty)) {
-        fatal_error("type_sizeof: type size cannot be determined");
-    }
-
-    if (ty->kind == TypeKind_ptr) {
-        return 8;
-    } else if (ty->kind == TypeKind_char) {
-        return 1;
-    } else if (ty->kind == TypeKind_int) {
-        return 4;
-    } else if (ty->kind == TypeKind_long) {
-        return 8;
-    } else if (ty->kind == TypeKind_enum) {
-        return 4;
-    } else {
-        return type_sizeof_struct(ty);
-    }
-}
-
-int type_alignof(Type* ty) {
-    if (!type_is_unsized(ty)) {
-        fatal_error("type_alignof: type size cannot be determined");
-    }
-
-    if (ty->kind == TypeKind_ptr) {
-        return 8;
-    } else if (ty->kind == TypeKind_char) {
-        return 1;
-    } else if (ty->kind == TypeKind_int) {
-        return 4;
-    } else if (ty->kind == TypeKind_long) {
-        return 8;
-    } else if (ty->kind == TypeKind_enum) {
-        return 4;
-    } else {
-        return type_alignof_struct(ty);
-    }
-}
-
-enum AstNodeKind {
-    AstNodeKind_unknown,
-
-    AstNodeKind_assign_expr,
-    AstNodeKind_binary_expr,
-    AstNodeKind_break_stmt,
-    AstNodeKind_continue_stmt,
-    AstNodeKind_deref_expr,
-    AstNodeKind_do_while_stmt,
-    AstNodeKind_enum_def,
-    AstNodeKind_enum_member,
-    AstNodeKind_expr_stmt,
-    AstNodeKind_for_stmt,
-    AstNodeKind_func_call,
-    AstNodeKind_func_decl,
-    AstNodeKind_func_def,
-    AstNodeKind_gvar,
-    AstNodeKind_gvar_decl,
-    AstNodeKind_if_stmt,
-    AstNodeKind_int_expr,
-    AstNodeKind_list,
-    AstNodeKind_logical_expr,
-    AstNodeKind_lvar,
-    AstNodeKind_lvar_decl,
-    AstNodeKind_param,
-    AstNodeKind_ref_expr,
-    AstNodeKind_return_stmt,
-    AstNodeKind_str_expr,
-    AstNodeKind_struct_decl,
-    AstNodeKind_struct_def,
-    AstNodeKind_struct_member,
-    AstNodeKind_type,
-    AstNodeKind_typedef_decl,
-    AstNodeKind_unary_expr,
-};
-typedef enum AstNodeKind AstNodeKind;
-
-#define node_items __n1
-#define node_len __i
-#define node_expr __n1
-#define node_lhs __n1
-#define node_rhs __n2
-#define node_operand __n1
-#define node_cond __n1
-#define node_init __n2
-#define node_update __n3
-#define node_then __n2
-#define node_else __n3
-#define node_body __n4
-#define node_members __n1
-#define node_params __n1
-#define node_args __n1
-#define node_int_value __i
-#define node_idx __i
-#define node_op __i
-
-struct AstNode {
-    AstNodeKind kind;
-    String name;
-    Type* ty;
-    struct AstNode* __n1;
-    struct AstNode* __n2;
-    struct AstNode* __n3;
-    struct AstNode* __n4;
-    int __i;
-};
-typedef struct AstNode AstNode;
-
-struct Program {
-    AstNode* funcs;
-    char** str_literals;
-};
-typedef struct Program Program;
-
-AstNode* ast_new(AstNodeKind kind) {
-    AstNode* ast = calloc(1, sizeof(AstNode));
-    ast->kind = kind;
-    return ast;
-}
-
-AstNode* ast_new_list(int capacity) {
-    AstNode* list = ast_new(AstNodeKind_list);
-    list->node_items = calloc(capacity, sizeof(AstNode));
-    list->node_len = 0;
-    return list;
-}
-
-void ast_append(AstNode* list, AstNode* item) {
-    if (list->kind != AstNodeKind_list) {
-        fatal_error("ast_append: ast is not a list");
-    }
-    if (!item) {
-        return;
-    }
-    memcpy(list->node_items + list->node_len, item, sizeof(AstNode));
-    ++list->node_len;
-}
-
-AstNode* ast_new_int(int v) {
-    AstNode* e = ast_new(AstNodeKind_int_expr);
-    e->node_int_value = v;
-    e->ty = type_new(TypeKind_int);
-    return e;
-}
-
-AstNode* ast_new_unary_expr(int op, AstNode* operand) {
-    AstNode* e = ast_new(AstNodeKind_unary_expr);
-    e->node_op = op;
-    e->node_operand = operand;
-    e->ty = type_new(TypeKind_int);
-    return e;
-}
-
-AstNode* ast_new_binary_expr(int op, AstNode* lhs, AstNode* rhs) {
-    AstNode* e = ast_new(AstNodeKind_binary_expr);
-    e->node_op = op;
-    e->node_lhs = lhs;
-    e->node_rhs = rhs;
-    if (op == TokenKind_plus) {
-        if (lhs->ty->kind == TypeKind_ptr) {
-            e->ty = lhs->ty;
-        } else if (rhs->ty->kind == TypeKind_ptr) {
-            e->ty = rhs->ty;
-        } else {
-            e->ty = type_new(TypeKind_int);
-        }
-    } else if (op == TokenKind_minus) {
-        if (lhs->ty->kind == TypeKind_ptr) {
-            e->ty = lhs->ty;
-        } else {
-            e->ty = type_new(TypeKind_int);
-        }
-    } else {
-        e->ty = type_new(TypeKind_int);
-    }
-    return e;
-}
-
-AstNode* ast_new_assign_expr(int op, AstNode* lhs, AstNode* rhs) {
-    AstNode* e = ast_new(AstNodeKind_assign_expr);
-    e->node_op = op;
-    e->node_lhs = lhs;
-    e->node_rhs = rhs;
-    e->ty = lhs->ty;
-    return e;
-}
-
-AstNode* ast_new_assign_add_expr(AstNode* lhs, AstNode* rhs) {
-    if (lhs->ty->kind == TypeKind_ptr) {
-        rhs = ast_new_binary_expr(TokenKind_star, rhs, ast_new_int(type_sizeof(lhs->ty->to)));
-    } else if (rhs->ty->kind == TypeKind_ptr) {
-        lhs = ast_new_binary_expr(TokenKind_star, lhs, ast_new_int(type_sizeof(rhs->ty->to)));
-    }
-    return ast_new_assign_expr(TokenKind_assign_add, lhs, rhs);
-}
-
-AstNode* ast_new_assign_sub_expr(AstNode* lhs, AstNode* rhs) {
-    if (lhs->ty->kind == TypeKind_ptr) {
-        rhs = ast_new_binary_expr(TokenKind_star, rhs, ast_new_int(type_sizeof(lhs->ty->to)));
-    }
-    return ast_new_assign_expr(TokenKind_assign_sub, lhs, rhs);
-}
-
-AstNode* ast_new_ref_expr(AstNode* operand) {
-    AstNode* e = ast_new(AstNodeKind_ref_expr);
-    e->node_operand = operand;
-    e->ty = type_new_ptr(operand->ty);
-    return e;
-}
-
-AstNode* ast_new_deref_expr(AstNode* operand) {
-    AstNode* e = ast_new(AstNodeKind_deref_expr);
-    e->node_operand = operand;
-    e->ty = operand->ty->to;
-    return e;
-}
-
-AstNode* ast_new_member_access_expr(AstNode* obj, const String* name) {
-    AstNode* e = ast_new(AstNodeKind_deref_expr);
-    e->node_operand = ast_new_binary_expr(TokenKind_plus, obj, ast_new_int(type_offsetof(obj->ty->to, name)));
-    e->ty = type_member_typeof(obj->ty->to, name);
-    e->node_operand->ty = type_new_ptr(e->ty);
-    return e;
-}
-
-int type_sizeof_struct(Type* ty) {
-    int next_offset = 0;
-    int struct_align = 0;
-    int padding;
-
-    int i;
-    for (i = 0; i < ty->def->node_members->node_len; ++i) {
-        AstNode* member = ty->def->node_members->node_items + i;
-        int size = type_sizeof(member->ty);
-        int align = type_alignof(member->ty);
-
-        if (next_offset % align != 0) {
-            padding = align - next_offset % align;
-            next_offset += padding;
-        }
-        next_offset += size;
-        if (struct_align < align) {
-            struct_align = align;
-        }
-    }
-    if (next_offset % struct_align != 0) {
-        padding = struct_align - next_offset % struct_align;
-        next_offset += padding;
-    }
-    return next_offset;
-}
-
-int type_alignof_struct(Type* ty) {
-    int struct_align = 0;
-
-    int i;
-    for (i = 0; i < ty->def->node_members->node_len; ++i) {
-        AstNode* member = ty->def->node_members->node_items + i;
-        int align = type_alignof(member->ty);
-
-        if (struct_align < align) {
-            struct_align = align;
-        }
-    }
-    return struct_align;
-}
-
-int type_offsetof(Type* ty, const String* name) {
-    if (ty->kind != TypeKind_struct) {
-        fatal_error("type_offsetof: type is not a struct");
-    }
-
-    int next_offset = 0;
-
-    int i;
-    for (i = 0; i < ty->def->node_members->node_len; ++i) {
-        AstNode* member = ty->def->node_members->node_items + i;
-        int size = type_sizeof(member->ty);
-        int align = type_alignof(member->ty);
-
-        if (next_offset % align != 0) {
-            int padding = align - next_offset % align;
-            next_offset += padding;
-        }
-        if (string_equals(&member->name, name)) {
-            return next_offset;
-        }
-        next_offset += size;
-    }
-
-    fatal_error("type_offsetof: member not found");
-}
-
-Type* type_member_typeof(Type* ty, const String* name) {
-    if (ty->kind != TypeKind_struct) {
-        fatal_error("type_offsetof: type is not a struct");
-    }
-
-    int i;
-    for (i = 0; i < ty->def->node_members->node_len; ++i) {
-        AstNode* member = ty->def->node_members->node_items + i;
-        if (string_equals(&member->name, name)) {
-            return member->ty;
-        }
-    }
-
-    fatal_error("type_offsetof: member not found");
-}
-
-#define LVAR_MAX 32
-
-struct LocalVar {
-    String name;
-    Type* ty;
-};
-typedef struct LocalVar LocalVar;
-
-struct GlobalVar {
-    String name;
-    Type* ty;
-};
-typedef struct GlobalVar GlobalVar;
-
-struct Func {
-    String name;
-    Type* ty;
-};
-typedef struct Func Func;
-
-struct Parser {
-    Token* tokens;
-    int pos;
-    LocalVar* lvars;
-    int n_lvars;
-    GlobalVar* gvars;
-    int n_gvars;
-    Func* funcs;
-    int n_funcs;
-    AstNode* structs;
-    int n_structs;
-    AstNode* enums;
-    int n_enums;
-    AstNode* typedefs;
-    int n_typedefs;
-    char** str_literals;
-    int n_str_literals;
-};
-typedef struct Parser Parser;
-
-Parser* parser_new(Token* tokens) {
-    Parser* p = calloc(1, sizeof(Parser));
-    p->tokens = tokens;
-    p->gvars = calloc(128, sizeof(GlobalVar));
-    p->funcs = calloc(256, sizeof(Func));
-    p->structs = calloc(64, sizeof(AstNode));
-    p->enums = calloc(16, sizeof(AstNode));
-    p->typedefs = calloc(64, sizeof(AstNode));
-    p->str_literals = calloc(1024, sizeof(char*));
-    return p;
-}
-
-Token* peek_token(Parser* p) {
-    return p->tokens + p->pos;
-}
-
-Token* next_token(Parser* p) {
-    ++p->pos;
-    return p->tokens + p->pos - 1;
-}
-
-int eof(Parser* p) {
-    return peek_token(p)->kind != TokenKind_eof;
-}
-
-Token* expect(Parser* p, int expected) {
-    Token* t = next_token(p);
-    if (t->kind == expected) {
-        return t;
-    }
-
-    char* buf = calloc(1024, sizeof(char));
-    sprintf(buf, "expected '%s', but got '%s'", token_kind_stringify(expected), token_stringify(t));
-    fatal_error(buf);
-}
-
-int find_lvar(Parser* p, const String* name) {
-    int i;
-    for (i = 0; i < p->n_lvars; ++i) {
-        if (string_equals(&p->lvars[i].name, name)) {
-            return i;
-        }
-    }
-    return -1;
-}
-
-int find_gvar(Parser* p, const String* name) {
-    int i;
-    for (i = 0; i < p->n_gvars; ++i) {
-        if (string_equals(&p->gvars[i].name, name)) {
-            return i;
-        }
-    }
-    return -1;
-}
-
-int find_func(Parser* p, const String* name) {
-    int i;
-    for (i = 0; i < p->n_funcs; ++i) {
-        if (string_equals(&p->funcs[i].name, name)) {
-            return i;
-        }
-    }
-    return -1;
-}
-
-int find_struct(Parser* p, const String* name) {
-    int i;
-    for (i = 0; i < p->n_structs; ++i) {
-        if (string_equals(&p->structs[i].name, name)) {
-            return i;
-        }
-    }
-    return -1;
-}
-
-int find_enum(Parser* p, const String* name) {
-    int i;
-    for (i = 0; i < p->n_enums; ++i) {
-        if (string_equals(&p->enums[i].name, name)) {
-            return i;
-        }
-    }
-    return -1;
-}
-
-int find_enum_member(Parser* p, const String* name) {
-    int i;
-    int j;
-    for (i = 0; i < p->n_enums; ++i) {
-        for (j = 0; j < p->enums[i].node_members->node_len; ++j) {
-            if (string_equals(&p->enums[i].node_members->node_items[j].name, name)) {
-                return i * 1000 + j;
-            }
-        }
-    }
-    return -1;
-}
-
-int find_typedef(Parser* p, const String* name) {
-    int i;
-    for (i = 0; i < p->n_typedefs; ++i) {
-        if (string_equals(&p->typedefs[i].name, name)) {
-            return i;
-        }
-    }
-    return -1;
-}
-
-AstNode* parse_expr(Parser* p);
-AstNode* parse_stmt(Parser* p);
-
-String* parse_ident(Parser* p) {
-    return &expect(p, TokenKind_ident)->raw;
-}
-
-int register_str_literal(Parser* p, char* s) {
-    p->str_literals[p->n_str_literals] = s;
-    ++p->n_str_literals;
-    return p->n_str_literals;
-}
-
-AstNode* parse_primary_expr(Parser* p) {
-    Token* t = next_token(p);
-    AstNode* e;
-    char* buf;
-    if (t->kind == TokenKind_literal_int) {
-        return ast_new_int(atoi(string_to_cstr(&t->raw)));
-    } else if (t->kind == TokenKind_literal_str) {
-        e = ast_new(AstNodeKind_str_expr);
-        e->node_idx = register_str_literal(p, string_to_cstr(&t->raw));
-        return e;
-    } else if (t->kind == TokenKind_paren_l) {
-        e = parse_expr(p);
-        expect(p, TokenKind_paren_r);
-        return e;
-    } else if (t->kind == TokenKind_ident) {
-        String* name = &t->raw;
-
-        if (peek_token(p)->kind == TokenKind_paren_l) {
-            e = ast_new(AstNodeKind_func_call);
-            int func_idx = find_func(p, name);
-            if (func_idx == -1) {
-                buf = calloc(1024, sizeof(char));
-                sprintf(buf, "undefined function: %.*s", name->len, name->data);
-                fatal_error(buf);
-            }
-            e->name.data = name->data;
-            e->name.len = name->len;
-            e->ty = p->funcs[func_idx].ty;
-            return e;
-        }
-
-        int lvar_idx = find_lvar(p, name);
-        if (lvar_idx == -1) {
-            int gvar_idx = find_gvar(p, name);
-            if (gvar_idx == -1) {
-                int enum_member_idx = find_enum_member(p, name);
-                if (enum_member_idx == -1) {
-                    buf = calloc(1024, sizeof(char));
-                    sprintf(buf, "undefined variable: %.*s", name->len, name->data);
-                    fatal_error(buf);
-                }
-                int enum_idx = enum_member_idx / 1000;
-                int n = enum_member_idx % 1000;
-                e = ast_new_int(p->enums[enum_idx].node_members->node_items[n].node_int_value);
-                e->ty = type_new(TypeKind_enum);
-                e->ty->def = p->enums + enum_idx;
-                return e;
-            }
-            e = ast_new(AstNodeKind_gvar);
-            e->name.data = name->data;
-            e->name.len = name->len;
-            e->ty = p->gvars[gvar_idx].ty;
-            return e;
-        }
-
-        e = ast_new(AstNodeKind_lvar);
-        e->name.data = name->data;
-        e->name.len = name->len;
-        e->node_idx = lvar_idx;
-        e->ty = p->lvars[lvar_idx].ty;
-        return e;
-    } else {
-        buf = calloc(1024, sizeof(char));
-        sprintf(buf, "expected primary expression, but got '%s'", token_stringify(t));
-        fatal_error(buf);
-    }
-}
-
-AstNode* parse_arg_list(Parser* p) {
-    AstNode* list = ast_new_list(6);
-    while (peek_token(p)->kind != TokenKind_paren_r) {
-        AstNode* arg = parse_expr(p);
-        ast_append(list, arg);
-        if (peek_token(p)->kind == TokenKind_comma) {
-            next_token(p);
-        } else {
-            break;
-        }
-    }
-    if (list->node_len > 6) {
-        fatal_error("too many arguments");
-    }
-    return list;
-}
-
-AstNode* parse_postfix_expr(Parser* p) {
-    AstNode* ret = parse_primary_expr(p);
-    String* name;
-    while (1) {
-        TokenKind tk = peek_token(p)->kind;
-        if (tk == TokenKind_paren_l) {
-            next_token(p);
-            AstNode* args = parse_arg_list(p);
-            expect(p, TokenKind_paren_r);
-            ret->node_args = args;
-        } else if (tk == TokenKind_bracket_l) {
-            next_token(p);
-            AstNode* idx = parse_expr(p);
-            expect(p, TokenKind_bracket_r);
-            idx = ast_new_binary_expr(TokenKind_star, idx, ast_new_int(type_sizeof(ret->ty->to)));
-            ret = ast_new_deref_expr(ast_new_binary_expr(TokenKind_plus, ret, idx));
-        } else if (tk == TokenKind_dot) {
-            next_token(p);
-            name = parse_ident(p);
-            ret = ast_new_member_access_expr(ast_new_ref_expr(ret), name);
-        } else if (tk == TokenKind_arrow) {
-            next_token(p);
-            name = parse_ident(p);
-            ret = ast_new_member_access_expr(ret, name);
-        } else {
-            break;
-        }
-    }
-    return ret;
-}
-
-int is_type_token(Parser* p, Token* token) {
-    if (token->kind == TokenKind_keyword_int || token->kind == TokenKind_keyword_long ||
-        token->kind == TokenKind_keyword_char || token->kind == TokenKind_keyword_void ||
-        token->kind == TokenKind_keyword_enum || token->kind == TokenKind_keyword_struct ||
-        token->kind == TokenKind_keyword_const) {
-        return 1;
-    }
-    if (token->kind != TokenKind_ident) {
-        return 0;
-    }
-    return find_typedef(p, &token->raw) != -1;
-}
-
-Type* parse_type(Parser* p) {
-    Token* t = next_token(p);
-    char* buf;
-    String* name;
-    if (t->kind == TokenKind_keyword_const) {
-        t = next_token(p);
-    }
-    if (!is_type_token(p, t)) {
-        buf = calloc(1024, sizeof(char));
-        sprintf(buf, "parse_type: expected type, but got '%s'", token_stringify(t));
-        fatal_error(buf);
-    }
-    Type* ty;
-    if (t->kind == TokenKind_ident) {
-        int typedef_idx = find_typedef(p, &t->raw);
-        if (typedef_idx == -1) {
-            buf = calloc(1024, sizeof(char));
-            sprintf(buf, "parse_type: unknown typedef, %.*s", t->raw.len, t->raw.data);
-            fatal_error(buf);
-        }
-        ty = p->typedefs[typedef_idx].ty;
-    } else {
-        ty = type_new(TypeKind_unknown);
-        if (t->kind == TokenKind_keyword_int) {
-            ty->kind = TypeKind_int;
-        } else if (t->kind == TokenKind_keyword_long) {
-            ty->kind = TypeKind_long;
-        } else if (t->kind == TokenKind_keyword_char) {
-            ty->kind = TypeKind_char;
-        } else if (t->kind == TokenKind_keyword_void) {
-            ty->kind = TypeKind_void;
-        } else if (t->kind == TokenKind_keyword_enum) {
-            ty->kind = TypeKind_enum;
-            name = parse_ident(p);
-            int enum_idx = find_enum(p, name);
-            if (enum_idx == -1) {
-                buf = calloc(1024, sizeof(char));
-                sprintf(buf, "parse_type: unknown enum, %.*s", name->len, name->data);
-                fatal_error(buf);
-            }
-            ty->def = p->enums + enum_idx;
-        } else if (t->kind == TokenKind_keyword_struct) {
-            ty->kind = TypeKind_struct;
-            name = parse_ident(p);
-            int struct_idx = find_struct(p, name);
-            if (struct_idx == -1) {
-                buf = calloc(1024, sizeof(char));
-                sprintf(buf, "parse_type: unknown struct, %.*s", name->len, name->data);
-                fatal_error(buf);
-            }
-            ty->def = p->structs + struct_idx;
-        } else {
-            unreachable();
-        }
-    }
-    while (1) {
-        if (peek_token(p)->kind == TokenKind_star) {
-            next_token(p);
-            ty = type_new_ptr(ty);
-        } else {
-            break;
-        }
-    }
-    return ty;
-}
-
-AstNode* parse_prefix_expr(Parser* p) {
-    AstNode* operand;
-    TokenKind op = peek_token(p)->kind;
-    if (op == TokenKind_minus) {
-        next_token(p);
-        operand = parse_prefix_expr(p);
-        return ast_new_binary_expr(op, ast_new_int(0), operand);
-    } else if (op == TokenKind_not) {
-        next_token(p);
-        operand = parse_prefix_expr(p);
-        return ast_new_unary_expr(op, operand);
-    } else if (op == TokenKind_and) {
-        next_token(p);
-        operand = parse_prefix_expr(p);
-        return ast_new_ref_expr(operand);
-    } else if (op == TokenKind_star) {
-        next_token(p);
-        operand = parse_prefix_expr(p);
-        return ast_new_deref_expr(operand);
-    } else if (op == TokenKind_plusplus) {
-        next_token(p);
-        operand = parse_prefix_expr(p);
-        return ast_new_assign_add_expr(operand, ast_new_int(1));
-    } else if (op == TokenKind_minusminus) {
-        next_token(p);
-        operand = parse_prefix_expr(p);
-        return ast_new_assign_sub_expr(operand, ast_new_int(1));
-    } else if (op == TokenKind_keyword_sizeof) {
-        next_token(p);
-        expect(p, TokenKind_paren_l);
-        Type* ty = parse_type(p);
-        expect(p, TokenKind_paren_r);
-        return ast_new_int(type_sizeof(ty));
-    }
-    return parse_postfix_expr(p);
-}
-
-AstNode* parse_multiplicative_expr(Parser* p) {
-    AstNode* lhs = parse_prefix_expr(p);
-    while (1) {
-        TokenKind op = peek_token(p)->kind;
-        if (op == TokenKind_star || op == TokenKind_slash || op == TokenKind_percent) {
-            next_token(p);
-            AstNode* rhs = parse_prefix_expr(p);
-            lhs = ast_new_binary_expr(op, lhs, rhs);
-        } else {
-            break;
-        }
-    }
-    return lhs;
-}
-
-AstNode* parse_additive_expr(Parser* p) {
-    AstNode* lhs = parse_multiplicative_expr(p);
-    AstNode* rhs;
-    while (1) {
-        TokenKind op = peek_token(p)->kind;
-        if (op == TokenKind_plus) {
-            next_token(p);
-            rhs = parse_multiplicative_expr(p);
-            if (lhs->ty->kind == TypeKind_ptr) {
-                lhs = ast_new_binary_expr(
-                    op, lhs, ast_new_binary_expr(TokenKind_star, rhs, ast_new_int(type_sizeof(lhs->ty->to))));
-            } else if (rhs->ty->kind == TypeKind_ptr) {
-                lhs = ast_new_binary_expr(
-                    op, ast_new_binary_expr(TokenKind_star, lhs, ast_new_int(type_sizeof(rhs->ty->to))), rhs);
-            } else {
-                lhs = ast_new_binary_expr(op, lhs, rhs);
-            }
-        } else if (op == TokenKind_minus) {
-            next_token(p);
-            rhs = parse_multiplicative_expr(p);
-            if (lhs->ty->kind == TypeKind_ptr) {
-                if (rhs->ty->kind == TypeKind_ptr) {
-                    // (a - b) / sizeof(a)
-                    lhs = ast_new_binary_expr(TokenKind_slash, ast_new_binary_expr(op, lhs, rhs),
-                                              ast_new_int(type_sizeof(lhs->ty->to)));
-                } else {
-                    // a - b*sizeof(a)
-                    lhs = ast_new_binary_expr(
-                        op, lhs, ast_new_binary_expr(TokenKind_star, rhs, ast_new_int(type_sizeof(lhs->ty->to))));
-                }
-            } else {
-                lhs = ast_new_binary_expr(op, lhs, rhs);
-            }
-        } else {
-            break;
-        }
-    }
-    return lhs;
-}
-
-AstNode* parse_relational_expr(Parser* p) {
-    AstNode* lhs = parse_additive_expr(p);
-    AstNode* rhs;
-    while (1) {
-        TokenKind op = peek_token(p)->kind;
-        if (op == TokenKind_lt || op == TokenKind_le) {
-            next_token(p);
-            rhs = parse_additive_expr(p);
-            lhs = ast_new_binary_expr(op, lhs, rhs);
-        } else if (op == TokenKind_gt) {
-            next_token(p);
-            rhs = parse_additive_expr(p);
-            lhs = ast_new_binary_expr(TokenKind_lt, rhs, lhs);
-        } else if (op == TokenKind_ge) {
-            next_token(p);
-            rhs = parse_additive_expr(p);
-            lhs = ast_new_binary_expr(TokenKind_le, rhs, lhs);
-        } else {
-            break;
-        }
-    }
-    return lhs;
-}
-
-AstNode* parse_equality_expr(Parser* p) {
-    AstNode* lhs = parse_relational_expr(p);
-    while (1) {
-        TokenKind op = peek_token(p)->kind;
-        if (op == TokenKind_eq || op == TokenKind_ne) {
-            next_token(p);
-            AstNode* rhs = parse_relational_expr(p);
-            lhs = ast_new_binary_expr(op, lhs, rhs);
-        } else {
-            break;
-        }
-    }
-    return lhs;
-}
-
-AstNode* parse_logical_and_expr(Parser* p) {
-    AstNode* lhs = parse_equality_expr(p);
-    while (1) {
-        TokenKind op = peek_token(p)->kind;
-        if (op == TokenKind_andand) {
-            next_token(p);
-            AstNode* rhs = parse_equality_expr(p);
-            AstNode* e = ast_new(AstNodeKind_logical_expr);
-            e->node_op = op;
-            e->node_lhs = lhs;
-            e->node_rhs = rhs;
-            e->ty = type_new(TypeKind_int);
-            lhs = e;
-        } else {
-            break;
-        }
-    }
-    return lhs;
-}
-
-AstNode* parse_logical_or_expr(Parser* p) {
-    AstNode* lhs = parse_logical_and_expr(p);
-    while (1) {
-        TokenKind op = peek_token(p)->kind;
-        if (op == TokenKind_oror) {
-            next_token(p);
-            AstNode* rhs = parse_logical_and_expr(p);
-            AstNode* e = ast_new(AstNodeKind_logical_expr);
-            e->node_op = op;
-            e->node_lhs = lhs;
-            e->node_rhs = rhs;
-            e->ty = type_new(TypeKind_int);
-            lhs = e;
-        } else {
-            break;
-        }
-    }
-    return lhs;
-}
-
-AstNode* parse_assignment_expr(Parser* p) {
-    AstNode* lhs = parse_logical_or_expr(p);
-    AstNode* rhs;
-    while (1) {
-        TokenKind op = peek_token(p)->kind;
-        if (op == TokenKind_assign) {
-            next_token(p);
-            rhs = parse_logical_or_expr(p);
-            lhs = ast_new_assign_expr(op, lhs, rhs);
-        } else if (op == TokenKind_assign_add) {
-            next_token(p);
-            rhs = parse_logical_or_expr(p);
-            lhs = ast_new_assign_add_expr(lhs, rhs);
-        } else if (op == TokenKind_assign_sub) {
-            next_token(p);
-            rhs = parse_logical_or_expr(p);
-            lhs = ast_new_assign_sub_expr(lhs, rhs);
-        } else {
-            break;
-        }
-    }
-    return lhs;
-}
-
-AstNode* parse_expr(Parser* p) {
-    return parse_assignment_expr(p);
-}
-
-AstNode* parse_return_stmt(Parser* p) {
-    expect(p, TokenKind_keyword_return);
-    if (peek_token(p)->kind == TokenKind_semicolon) {
-        next_token(p);
-        return ast_new(AstNodeKind_return_stmt);
-    }
-
-    AstNode* expr = parse_expr(p);
-    expect(p, TokenKind_semicolon);
-
-    AstNode* ret = ast_new(AstNodeKind_return_stmt);
-    ret->node_expr = expr;
-    return ret;
-}
-
-AstNode* parse_if_stmt(Parser* p) {
-    expect(p, TokenKind_keyword_if);
-    expect(p, TokenKind_paren_l);
-    AstNode* cond = parse_expr(p);
-    expect(p, TokenKind_paren_r);
-    AstNode* then_body = parse_stmt(p);
-    AstNode* else_body = NULL;
-    if (peek_token(p)->kind == TokenKind_keyword_else) {
-        next_token(p);
-        else_body = parse_stmt(p);
-    }
-
-    AstNode* stmt = ast_new(AstNodeKind_if_stmt);
-    stmt->node_cond = cond;
-    stmt->node_then = then_body;
-    stmt->node_else = else_body;
-    return stmt;
-}
-
-AstNode* parse_for_stmt(Parser* p) {
-    expect(p, TokenKind_keyword_for);
-    expect(p, TokenKind_paren_l);
-    AstNode* init = NULL;
-    AstNode* cond = NULL;
-    AstNode* update = NULL;
-    if (peek_token(p)->kind != TokenKind_semicolon) {
-        init = parse_expr(p);
-    }
-    expect(p, TokenKind_semicolon);
-    if (peek_token(p)->kind != TokenKind_semicolon) {
-        cond = parse_expr(p);
-    } else {
-        cond = ast_new_int(1);
-    }
-    expect(p, TokenKind_semicolon);
-    if (peek_token(p)->kind != TokenKind_paren_r) {
-        update = parse_expr(p);
-    }
-    expect(p, TokenKind_paren_r);
-    AstNode* body = parse_stmt(p);
-
-    AstNode* stmt = ast_new(AstNodeKind_for_stmt);
-    stmt->node_cond = cond;
-    stmt->node_init = init;
-    stmt->node_update = update;
-    stmt->node_body = body;
-    return stmt;
-}
-
-AstNode* parse_while_stmt(Parser* p) {
-    expect(p, TokenKind_keyword_while);
-    expect(p, TokenKind_paren_l);
-    AstNode* cond = parse_expr(p);
-    expect(p, TokenKind_paren_r);
-    AstNode* body = parse_stmt(p);
-
-    AstNode* stmt = ast_new(AstNodeKind_for_stmt);
-    stmt->node_cond = cond;
-    stmt->node_body = body;
-    return stmt;
-}
-
-AstNode* parse_do_while_stmt(Parser* p) {
-    expect(p, TokenKind_keyword_do);
-    AstNode* body = parse_stmt(p);
-    expect(p, TokenKind_keyword_while);
-    expect(p, TokenKind_paren_l);
-    AstNode* cond = parse_expr(p);
-    expect(p, TokenKind_paren_r);
-    expect(p, TokenKind_semicolon);
-
-    AstNode* stmt = ast_new(AstNodeKind_do_while_stmt);
-    stmt->node_cond = cond;
-    stmt->node_body = body;
-    return stmt;
-}
-
-AstNode* parse_break_stmt(Parser* p) {
-    expect(p, TokenKind_keyword_break);
-    expect(p, TokenKind_semicolon);
-    return ast_new(AstNodeKind_break_stmt);
-}
-
-AstNode* parse_continue_stmt(Parser* p) {
-    expect(p, TokenKind_keyword_continue);
-    expect(p, TokenKind_semicolon);
-    return ast_new(AstNodeKind_continue_stmt);
-}
-
-AstNode* parse_var_decl(Parser* p) {
-    Type* ty = parse_type(p);
-    if (!type_is_unsized(ty)) {
-        fatal_error("parse_var_decl: invalid type for variable");
-    }
-    String* name = parse_ident(p);
-
-    AstNode* init = NULL;
-    if (peek_token(p)->kind == TokenKind_assign) {
-        next_token(p);
-        init = parse_expr(p);
-    }
-    expect(p, TokenKind_semicolon);
-
-    if (find_lvar(p, name) != -1 || find_gvar(p, name) != -1) {
-        char* buf = calloc(1024, sizeof(char));
-        sprintf(buf, "parse_var_decl: %.*s redeclared", name->len, name->data);
-        fatal_error(buf);
-    }
-    p->lvars[p->n_lvars].name.data = name->data;
-    p->lvars[p->n_lvars].name.len = name->len;
-    p->lvars[p->n_lvars].ty = ty;
-    ++p->n_lvars;
-
-    AstNode* ret;
-    if (init) {
-        AstNode* lhs = ast_new(AstNodeKind_lvar);
-        lhs->name.data = name->data;
-        lhs->name.len = name->len;
-        lhs->node_idx = p->n_lvars - 1;
-        lhs->ty = ty;
-        AstNode* assign = ast_new_assign_expr(TokenKind_assign, lhs, init);
-        ret = ast_new(AstNodeKind_expr_stmt);
-        ret->node_expr = assign;
-    } else {
-        ret = ast_new(AstNodeKind_lvar_decl);
-    }
-    return ret;
-}
-
-AstNode* parse_expr_stmt(Parser* p) {
-    AstNode* e = parse_expr(p);
-    expect(p, TokenKind_semicolon);
-    AstNode* stmt = ast_new(AstNodeKind_expr_stmt);
-    stmt->node_expr = e;
-    return stmt;
-}
-
-AstNode* parse_block_stmt(Parser* p) {
-    AstNode* list = ast_new_list(1024);
-    expect(p, TokenKind_brace_l);
-    while (peek_token(p)->kind != TokenKind_brace_r) {
-        AstNode* stmt = parse_stmt(p);
-        ast_append(list, stmt);
-    }
-    expect(p, TokenKind_brace_r);
-    return list;
-}
-
-AstNode* parse_stmt(Parser* p) {
-    Token* t = peek_token(p);
-    if (t->kind == TokenKind_keyword_return) {
-        return parse_return_stmt(p);
-    } else if (t->kind == TokenKind_keyword_if) {
-        return parse_if_stmt(p);
-    } else if (t->kind == TokenKind_keyword_for) {
-        return parse_for_stmt(p);
-    } else if (t->kind == TokenKind_keyword_while) {
-        return parse_while_stmt(p);
-    } else if (t->kind == TokenKind_keyword_do) {
-        return parse_do_while_stmt(p);
-    } else if (t->kind == TokenKind_keyword_break) {
-        return parse_break_stmt(p);
-    } else if (t->kind == TokenKind_keyword_continue) {
-        return parse_continue_stmt(p);
-    } else if (t->kind == TokenKind_brace_l) {
-        return parse_block_stmt(p);
-    } else if (is_type_token(p, t)) {
-        return parse_var_decl(p);
-    } else {
-        return parse_expr_stmt(p);
-    }
-}
-
-void enter_func(Parser* p) {
-    p->lvars = calloc(LVAR_MAX, sizeof(LocalVar));
-    p->n_lvars = 0;
-}
-
-void register_params(Parser* p, AstNode* params) {
-    int i;
-    for (i = 0; i < params->node_len; ++i) {
-        AstNode* param = params->node_items + i;
-        p->lvars[p->n_lvars].name.data = param->name.data;
-        p->lvars[p->n_lvars].name.len = param->name.len;
-        p->lvars[p->n_lvars].ty = param->ty;
-        ++p->n_lvars;
-    }
-}
-
-void register_func(Parser* p, const String* name, Type* ty) {
-    p->funcs[p->n_funcs].name.data = name->data;
-    p->funcs[p->n_funcs].name.len = name->len;
-    p->funcs[p->n_funcs].ty = ty;
-    ++p->n_funcs;
-}
-
-AstNode* parse_param(Parser* p) {
-    Type* ty = parse_type(p);
-    String* name = NULL;
-    TokenKind tk = peek_token(p)->kind;
-    if (tk != TokenKind_comma && tk != TokenKind_paren_r) {
-        name = parse_ident(p);
-    }
-    AstNode* param = ast_new(AstNodeKind_param);
-    param->ty = ty;
-    if (name) {
-        param->name.data = name->data;
-        param->name.len = name->len;
-    }
-    return param;
-}
-
-AstNode* parse_param_list(Parser* p) {
-    int has_void = 0;
-    AstNode* list = ast_new_list(6);
-    while (peek_token(p)->kind != TokenKind_paren_r) {
-        if (peek_token(p)->kind == TokenKind_ellipsis) {
-            next_token(p);
-            break;
-        }
-        AstNode* param = parse_param(p);
-        has_void = has_void || param->ty->kind == TypeKind_void;
-        ast_append(list, param);
-        if (peek_token(p)->kind == TokenKind_comma) {
-            next_token(p);
-        } else {
-            break;
-        }
-    }
-    if (list->node_len > 6) {
-        fatal_error("too many parameters");
-    }
-    if (has_void) {
-        if (list->node_len != 1) {
-            fatal_error("invalid use of void param");
-        }
-        list->node_len = 0;
-    }
-    return list;
-}
-
-AstNode* parse_func_decl_or_def(Parser* p) {
-    Type* ty = parse_type(p);
-    String* name = parse_ident(p);
-    register_func(p, name, ty);
-    expect(p, TokenKind_paren_l);
-    AstNode* params = parse_param_list(p);
-    expect(p, TokenKind_paren_r);
-    if (peek_token(p)->kind == TokenKind_semicolon) {
-        next_token(p);
-        return ast_new(AstNodeKind_func_decl);
-    }
-    enter_func(p);
-    register_params(p, params);
-    AstNode* body = parse_block_stmt(p);
-    AstNode* func = ast_new(AstNodeKind_func_def);
-    func->ty = ty;
-    func->name.data = name->data;
-    func->name.len = name->len;
-    func->node_params = params;
-    func->node_body = body;
-    return func;
-}
-
-AstNode* parse_struct_member(Parser* p) {
-    Type* ty = parse_type(p);
-    String* name = parse_ident(p);
-    expect(p, TokenKind_semicolon);
-    AstNode* member = ast_new(AstNodeKind_struct_member);
-    member->name.data = name->data;
-    member->name.len = name->len;
-    member->ty = ty;
-    return member;
-}
-
-AstNode* parse_struct_members(Parser* p) {
-    AstNode* list = ast_new_list(16);
-    while (peek_token(p)->kind != TokenKind_brace_r) {
-        AstNode* member = parse_struct_member(p);
-        ast_append(list, member);
-    }
-    return list;
-}
-
-AstNode* parse_struct_decl_or_def(Parser* p) {
-    expect(p, TokenKind_keyword_struct);
-    String* name = parse_ident(p);
-
-    if (peek_token(p)->kind != TokenKind_semicolon && peek_token(p)->kind != TokenKind_brace_l) {
-        p->pos = p->pos - 2;
-        return parse_func_decl_or_def(p);
-    }
-
-    int struct_idx = find_struct(p, name);
-    if (struct_idx == -1) {
-        struct_idx = p->n_structs;
-        p->structs[struct_idx].kind = AstNodeKind_struct_def;
-        p->structs[struct_idx].name.data = name->data;
-        p->structs[struct_idx].name.len = name->len;
-        ++p->n_structs;
-    }
-    if (peek_token(p)->kind == TokenKind_semicolon) {
-        next_token(p);
-        return ast_new(AstNodeKind_struct_decl);
-    }
-    if (p->structs[struct_idx].node_members) {
-        char* buf = calloc(1024, sizeof(char));
-        sprintf(buf, "parse_struct_decl_or_def: struct %.*s redefined", name->len, name->data);
-        fatal_error(buf);
-    }
-    expect(p, TokenKind_brace_l);
-    AstNode* members = parse_struct_members(p);
-    expect(p, TokenKind_brace_r);
-    expect(p, TokenKind_semicolon);
-    p->structs[struct_idx].node_members = members;
-    return p->structs + struct_idx;
-}
-
-AstNode* parse_enum_member(Parser* p) {
-    String* name = parse_ident(p);
-    AstNode* member = ast_new(AstNodeKind_enum_member);
-    member->name.data = name->data;
-    member->name.len = name->len;
-    return member;
-}
-
-AstNode* parse_enum_members(Parser* p) {
-    int next_value = 0;
-    AstNode* list = ast_new_list(256);
-    while (peek_token(p)->kind != TokenKind_brace_r) {
-        AstNode* member = parse_enum_member(p);
-        member->node_int_value = next_value;
-        ++next_value;
-        ast_append(list, member);
-        if (peek_token(p)->kind != TokenKind_comma) {
-            break;
-        }
-        next_token(p);
-    }
-    return list;
-}
-
-AstNode* parse_enum_def(Parser* p) {
-    expect(p, TokenKind_keyword_enum);
-    String* name = parse_ident(p);
-
-    if (peek_token(p)->kind != TokenKind_brace_l) {
-        p->pos = p->pos - 2;
-        return parse_func_decl_or_def(p);
-    }
-
-    int enum_idx = find_enum(p, name);
-    if (enum_idx == -1) {
-        enum_idx = p->n_enums;
-        p->enums[enum_idx].kind = AstNodeKind_enum_def;
-        p->enums[enum_idx].name.data = name->data;
-        p->enums[enum_idx].name.len = name->len;
-        ++p->n_enums;
-    } else {
-        char* buf = calloc(1024, sizeof(char));
-        sprintf(buf, "parse_enum_def: enum %.*s redefined", name->len, name->data);
-        fatal_error(buf);
-    }
-    expect(p, TokenKind_brace_l);
-    AstNode* members = parse_enum_members(p);
-    expect(p, TokenKind_brace_r);
-    expect(p, TokenKind_semicolon);
-    p->enums[enum_idx].node_members = members;
-    return p->enums + enum_idx;
-}
-
-AstNode* parse_typedef_decl(Parser* p) {
-    expect(p, TokenKind_keyword_typeof);
-    Type* ty = parse_type(p);
-    String* name = parse_ident(p);
-    expect(p, TokenKind_semicolon);
-    AstNode* decl = ast_new(AstNodeKind_typedef_decl);
-    decl->name.data = name->data;
-    decl->name.len = name->len;
-    decl->ty = ty;
-    p->typedefs[p->n_typedefs].name.data = name->data;
-    p->typedefs[p->n_typedefs].name.len = name->len;
-    p->typedefs[p->n_typedefs].ty = ty;
-    ++p->n_typedefs;
-    return decl;
-}
-
-AstNode* parse_extern_var_decl(Parser* p) {
-    expect(p, TokenKind_keyword_extern);
-    Type* ty = parse_type(p);
-    if (!type_is_unsized(ty)) {
-        fatal_error("parse_extern_var_decl: invalid type for variable");
-    }
-    String* name = parse_ident(p);
-    expect(p, TokenKind_semicolon);
-
-    if (find_lvar(p, name) != -1 || find_gvar(p, name) != -1) {
-        char* buf = calloc(1024, sizeof(char));
-        sprintf(buf, "parse_extern_var_decl: %.*s redeclared", name->len, name->data);
-        fatal_error(buf);
-    }
-    p->gvars[p->n_gvars].name.data = name->data;
-    p->gvars[p->n_gvars].name.len = name->len;
-    p->gvars[p->n_gvars].ty = ty;
-    ++p->n_gvars;
-
-    return ast_new(AstNodeKind_gvar_decl);
-}
-
-AstNode* parse_toplevel(Parser* p) {
-    TokenKind tk = peek_token(p)->kind;
-    if (tk == TokenKind_keyword_struct) {
-        return parse_struct_decl_or_def(p);
-    } else if (tk == TokenKind_keyword_enum) {
-        return parse_enum_def(p);
-    } else if (tk == TokenKind_keyword_typeof) {
-        return parse_typedef_decl(p);
-    } else if (tk == TokenKind_keyword_extern) {
-        return parse_extern_var_decl(p);
-    } else {
-        return parse_func_decl_or_def(p);
-    }
-}
-
-Program* parse(Token* tokens) {
-    Parser* p = parser_new(tokens);
-    AstNode* funcs = ast_new_list(1024);
-    while (eof(p)) {
-        AstNode* n = parse_toplevel(p);
-        if (n->kind == AstNodeKind_func_def) {
-            ast_append(funcs, n);
-        }
-    }
-    Program* prog = calloc(1, sizeof(Program));
-    prog->funcs = funcs;
-    prog->str_literals = p->str_literals;
-    return prog;
-}
-
-void analyze(Program* prog) {
-}
-
-enum GenMode {
-    GenMode_lval,
-    GenMode_rval,
-};
-typedef enum GenMode GenMode;
-
-struct CodeGen {
-    int next_label;
-    int* loop_labels;
-};
-typedef struct CodeGen CodeGen;
-
-CodeGen* codegen_new() {
-    CodeGen* g = calloc(1, sizeof(CodeGen));
-    g->next_label = 1;
-    g->loop_labels = calloc(1024, sizeof(int));
-    return g;
-}
-
-int codegen_new_label(CodeGen* g) {
-    int new_label = g->next_label;
-    ++g->next_label;
-    return new_label;
-}
-
-void codegen_expr(CodeGen* g, AstNode* ast, GenMode gen_mode);
-void codegen_stmt(CodeGen* g, AstNode* ast);
-
-const char* param_reg(int n) {
-    if (n == 0) {
-        return "rdi";
-    } else if (n == 1) {
-        return "rsi";
-    } else if (n == 2) {
-        return "rdx";
-    } else if (n == 3) {
-        return "rcx";
-    } else if (n == 4) {
-        return "r8";
-    } else if (n == 5) {
-        return "r9";
-    } else {
-        unreachable();
-    }
-}
-
-void codegen_func_prologue(CodeGen* g, AstNode* ast) {
-    printf("  push rbp\n");
-    printf("  mov rbp, rsp\n");
-    int i;
-    for (i = 0; i < ast->node_params->node_len; ++i) {
-        printf("  push %s\n", param_reg(i));
-    }
-    printf("  sub rsp, %d\n", 8 * LVAR_MAX);
-}
-
-void codegen_func_epilogue(CodeGen* g, AstNode* ast) {
-    printf("  mov rsp, rbp\n");
-    printf("  pop rbp\n");
-    printf("  ret\n");
-}
-
-void codegen_int_expr(CodeGen* g, AstNode* ast) {
-    printf("  push %d\n", ast->node_int_value);
-}
-
-void codegen_str_expr(CodeGen* g, AstNode* ast) {
-    printf("  mov rax, OFFSET FLAG:.Lstr__%d\n", ast->node_idx);
-    printf("  push rax\n");
-}
-
-void codegen_unary_expr(CodeGen* g, AstNode* ast) {
-    codegen_expr(g, ast->node_operand, GenMode_rval);
-    if (ast->node_op == TokenKind_not) {
-        printf("  pop rax\n");
-        printf("  mov rdi, 0\n");
-        printf("  cmp rax, rdi\n");
-        printf("  sete al\n");
-        printf("  movzb rax, al\n");
-        printf("  push rax\n");
-    } else {
-        unreachable();
-    }
-}
-
-void codegen_ref_expr(CodeGen* g, AstNode* ast, GenMode gen_mode) {
-    codegen_expr(g, ast->node_operand, GenMode_lval);
-}
-
-void codegen_lval2rval(Type* ty) {
-    int size = type_sizeof(ty);
-
-    printf("  pop rax\n");
-    if (size == 1) {
-        printf("  movsx rax, BYTE PTR [rax]\n");
-    } else if (size == 4) {
-        printf("  movsxd rax, DWORD PTR [rax]\n");
-    } else {
-        printf("  mov rax, [rax]\n");
-    }
-    printf("  push rax\n");
-}
-
-void codegen_deref_expr(CodeGen* g, AstNode* ast, GenMode gen_mode) {
-    codegen_expr(g, ast->node_operand, GenMode_rval);
-    if (gen_mode == GenMode_rval) {
-        codegen_lval2rval(ast->node_operand->ty->to);
-    }
-}
-
-void codegen_logical_expr(CodeGen* g, AstNode* ast) {
-    int label = codegen_new_label(g);
-
-    if (ast->node_op == TokenKind_andand) {
-        codegen_expr(g, ast->node_lhs, GenMode_rval);
-        printf("  pop rax\n");
-        printf("  cmp rax, 0\n");
-        printf("  je .Lelse%d\n", label);
-        codegen_expr(g, ast->node_rhs, GenMode_rval);
-        printf("  jmp .Lend%d\n", label);
-        printf(".Lelse%d:\n", label);
-        printf("  push 0\n");
-        printf(".Lend%d:\n", label);
-    } else {
-        codegen_expr(g, ast->node_lhs, GenMode_rval);
-        printf("  pop rax\n");
-        printf("  cmp rax, 0\n");
-        printf("  je .Lelse%d\n", label);
-        printf("  push 1\n");
-        printf("  jmp .Lend%d\n", label);
-        printf(".Lelse%d:\n", label);
-        codegen_expr(g, ast->node_rhs, GenMode_rval);
-        printf(".Lend%d:\n", label);
-    }
-}
-
-void codegen_binary_expr(CodeGen* g, AstNode* ast, GenMode gen_mode) {
-    codegen_expr(g, ast->node_lhs, gen_mode);
-    codegen_expr(g, ast->node_rhs, gen_mode);
-    printf("  pop rdi\n");
-    printf("  pop rax\n");
-    if (ast->node_op == TokenKind_plus) {
-        printf("  add rax, rdi\n");
-    } else if (ast->node_op == TokenKind_minus) {
-        printf("  sub rax, rdi\n");
-    } else if (ast->node_op == TokenKind_star) {
-        printf("  imul rax, rdi\n");
-    } else if (ast->node_op == TokenKind_slash) {
-        printf("  cqo\n");
-        printf("  idiv rdi\n");
-    } else if (ast->node_op == TokenKind_percent) {
-        printf("  cqo\n");
-        printf("  idiv rdi\n");
-        printf("  mov rax, rdx\n");
-    } else if (ast->node_op == TokenKind_eq) {
-        printf("  cmp rax, rdi\n");
-        printf("  sete al\n");
-        printf("  movzb rax, al\n");
-    } else if (ast->node_op == TokenKind_ne) {
-        printf("  cmp rax, rdi\n");
-        printf("  setne al\n");
-        printf("  movzb rax, al\n");
-    } else if (ast->node_op == TokenKind_lt) {
-        printf("  cmp rax, rdi\n");
-        printf("  setl al\n");
-        printf("  movzb rax, al\n");
-    } else if (ast->node_op == TokenKind_le) {
-        printf("  cmp rax, rdi\n");
-        printf("  setle al\n");
-        printf("  movzb rax, al\n");
-    } else {
-        unreachable();
-    }
-    printf("  push rax\n");
-}
-
-void codegen_assign_expr(CodeGen* g, AstNode* ast) {
-    codegen_expr(g, ast->node_lhs, GenMode_lval);
-    codegen_expr(g, ast->node_rhs, GenMode_rval);
-    if (ast->node_op == TokenKind_assign) {
-    } else if (ast->node_op == TokenKind_assign_add) {
-        printf("  pop rdi\n");
-        printf("  push [rsp]\n");
-        codegen_lval2rval(ast->node_lhs->ty);
-        printf("  pop rax\n");
-        printf("  add rax, rdi\n");
-        printf("  push rax\n");
-    } else if (ast->node_op == TokenKind_assign_sub) {
-        printf("  pop rdi\n");
-        printf("  push [rsp]\n");
-        codegen_lval2rval(ast->node_lhs->ty);
-        printf("  pop rax\n");
-        printf("  sub rax, rdi\n");
-        printf("  push rax\n");
-    } else {
-        unreachable();
-    }
-    printf("  pop rdi\n");
-    printf("  pop rax\n");
-    if (type_sizeof(ast->node_lhs->ty) == 1) {
-        printf("  mov BYTE PTR [rax], dil\n");
-    } else if (type_sizeof(ast->node_lhs->ty) == 4) {
-        printf("  mov DWORD PTR [rax], edi\n");
-    } else {
-        printf("  mov [rax], rdi\n");
-    }
-    printf("  push rdi\n");
-}
-
-void codegen_func_call(CodeGen* g, AstNode* ast) {
-    String* func_name = &ast->name;
-    AstNode* args = ast->node_args;
-    int i;
-    for (i = 0; i < args->node_len; ++i) {
-        AstNode* arg = args->node_items + i;
-        codegen_expr(g, arg, GenMode_rval);
-    }
-    for (i = args->node_len - 1; i >= 0; --i) {
-        printf("  pop %s\n", param_reg(i));
-    }
-
-    int label = codegen_new_label(g);
-
-    printf("  mov rax, rsp\n");
-    printf("  and rax, 15\n");
-    printf("  cmp rax, 0\n");
-    printf("  je .Laligned%d\n", label);
-
-    printf("  mov rax, 0\n");
-    printf("  sub rsp, 8\n");
-    printf("  call %.*s\n", func_name->len, func_name->data);
-    printf("  add rsp, 8\n");
-    printf("  push rax\n");
-
-    printf("  jmp .Lend%d\n", label);
-    printf(".Laligned%d:\n", label);
-
-    printf("  mov rax, 0\n");
-    printf("  call %.*s\n", func_name->len, func_name->data);
-    printf("  push rax\n");
-
-    printf(".Lend%d:\n", label);
-}
-
-void codegen_lvar(CodeGen* g, AstNode* ast, GenMode gen_mode) {
-    int offset = 8 + ast->node_idx * 8;
-    printf("  mov rax, rbp\n");
-    printf("  sub rax, %d\n", offset);
-    printf("  push rax\n");
-    if (gen_mode == GenMode_rval) {
-        codegen_lval2rval(ast->ty);
-    }
-}
-
-void codegen_gvar(CodeGen* g, AstNode* ast, GenMode gen_mode) {
-    if (gen_mode == GenMode_lval) {
-        fatal_error("unimplemented");
-    }
-    if (ast->ty->kind != TypeKind_ptr) {
-        fatal_error("unimplemented");
-    }
-    printf("  mov rax, QWORD PTR %.*s[rip]\n", ast->name.len, ast->name.data);
-    printf("  push rax\n");
-}
-
-void codegen_expr(CodeGen* g, AstNode* ast, GenMode gen_mode) {
-    if (ast->kind == AstNodeKind_int_expr) {
-        codegen_int_expr(g, ast);
-    } else if (ast->kind == AstNodeKind_str_expr) {
-        codegen_str_expr(g, ast);
-    } else if (ast->kind == AstNodeKind_unary_expr) {
-        codegen_unary_expr(g, ast);
-    } else if (ast->kind == AstNodeKind_ref_expr) {
-        codegen_ref_expr(g, ast, gen_mode);
-    } else if (ast->kind == AstNodeKind_deref_expr) {
-        codegen_deref_expr(g, ast, gen_mode);
-    } else if (ast->kind == AstNodeKind_binary_expr) {
-        codegen_binary_expr(g, ast, gen_mode);
-    } else if (ast->kind == AstNodeKind_logical_expr) {
-        codegen_logical_expr(g, ast);
-    } else if (ast->kind == AstNodeKind_assign_expr) {
-        codegen_assign_expr(g, ast);
-    } else if (ast->kind == AstNodeKind_func_call) {
-        codegen_func_call(g, ast);
-    } else if (ast->kind == AstNodeKind_lvar) {
-        codegen_lvar(g, ast, gen_mode);
-    } else if (ast->kind == AstNodeKind_gvar) {
-        codegen_gvar(g, ast, gen_mode);
-    } else {
-        unreachable();
-    }
-}
-
-void codegen_return_stmt(CodeGen* g, AstNode* ast) {
-    if (ast->node_expr) {
-        codegen_expr(g, ast->node_expr, GenMode_rval);
-        printf("  pop rax\n");
-    }
-    codegen_func_epilogue(g, ast);
-}
-
-void codegen_if_stmt(CodeGen* g, AstNode* ast) {
-    int label = codegen_new_label(g);
-
-    codegen_expr(g, ast->node_cond, GenMode_rval);
-    printf("  pop rax\n");
-    printf("  cmp rax, 0\n");
-    printf("  je .Lelse%d\n", label);
-    codegen_stmt(g, ast->node_then);
-    printf("  jmp .Lend%d\n", label);
-    printf(".Lelse%d:\n", label);
-    if (ast->node_else) {
-        codegen_stmt(g, ast->node_else);
-    }
-    printf(".Lend%d:\n", label);
-}
-
-void codegen_for_stmt(CodeGen* g, AstNode* ast) {
-    int label = codegen_new_label(g);
-    ++g->loop_labels;
-    *g->loop_labels = label;
-
-    if (ast->node_init) {
-        codegen_expr(g, ast->node_init, GenMode_rval);
-        printf("  pop rax\n");
-    }
-    printf(".Lbegin%d:\n", label);
-    codegen_expr(g, ast->node_cond, GenMode_rval);
-    printf("  pop rax\n");
-    printf("  cmp rax, 0\n");
-    printf("  je .Lend%d\n", label);
-    codegen_stmt(g, ast->node_body);
-    printf(".Lcontinue%d:\n", label);
-    if (ast->node_update) {
-        codegen_expr(g, ast->node_update, GenMode_rval);
-        printf("  pop rax\n");
-    }
-    printf("  jmp .Lbegin%d\n", label);
-    printf(".Lend%d:\n", label);
-
-    --g->loop_labels;
-}
-
-void codegen_do_while_stmt(CodeGen* g, AstNode* ast) {
-    int label = codegen_new_label(g);
-    ++g->loop_labels;
-    *g->loop_labels = label;
-
-    printf(".Lbegin%d:\n", label);
-    codegen_stmt(g, ast->node_body);
-    printf(".Lcontinue%d:\n", label);
-    codegen_expr(g, ast->node_cond, GenMode_rval);
-    printf("  pop rax\n");
-    printf("  cmp rax, 0\n");
-    printf("  je .Lend%d\n", label);
-    printf("  jmp .Lbegin%d\n", label);
-    printf(".Lend%d:\n", label);
-
-    --g->loop_labels;
-}
-
-void codegen_break_stmt(CodeGen* g, AstNode* ast) {
-    int label = *g->loop_labels;
-    printf("  jmp .Lend%d\n", label);
-}
-
-void codegen_continue_stmt(CodeGen* g, AstNode* ast) {
-    int label = *g->loop_labels;
-    printf("  jmp .Lcontinue%d\n", label);
-}
-
-void codegen_expr_stmt(CodeGen* g, AstNode* ast) {
-    codegen_expr(g, ast->node_expr, GenMode_rval);
-    printf("  pop rax\n");
-}
-
-void codegen_var_decl(CodeGen* g, AstNode* ast) {
-}
-
-void codegen_block_stmt(CodeGen* g, AstNode* ast) {
-    int i;
-    for (i = 0; i < ast->node_len; ++i) {
-        AstNode* stmt = ast->node_items + i;
-        codegen_stmt(g, stmt);
-    }
-}
-
-void codegen_stmt(CodeGen* g, AstNode* ast) {
-    if (ast->kind == AstNodeKind_list) {
-        codegen_block_stmt(g, ast);
-    } else if (ast->kind == AstNodeKind_return_stmt) {
-        codegen_return_stmt(g, ast);
-    } else if (ast->kind == AstNodeKind_if_stmt) {
-        codegen_if_stmt(g, ast);
-    } else if (ast->kind == AstNodeKind_for_stmt) {
-        codegen_for_stmt(g, ast);
-    } else if (ast->kind == AstNodeKind_do_while_stmt) {
-        codegen_do_while_stmt(g, ast);
-    } else if (ast->kind == AstNodeKind_break_stmt) {
-        codegen_break_stmt(g, ast);
-    } else if (ast->kind == AstNodeKind_continue_stmt) {
-        codegen_continue_stmt(g, ast);
-    } else if (ast->kind == AstNodeKind_expr_stmt) {
-        codegen_expr_stmt(g, ast);
-    } else if (ast->kind == AstNodeKind_lvar_decl) {
-        codegen_var_decl(g, ast);
-    } else {
-        unreachable();
-    }
-}
-
-void codegen_func(CodeGen* g, AstNode* ast) {
-    printf("%.*s:\n", ast->name.len, ast->name.data);
-
-    codegen_func_prologue(g, ast);
-    codegen_stmt(g, ast->node_body);
-    codegen_func_epilogue(g, ast);
-
-    printf("\n");
-}
-
-void codegen(Program* prog) {
-    CodeGen* g = codegen_new();
-
-    printf(".intel_syntax noprefix\n\n");
-
-    int i;
-    for (i = 0; prog->str_literals[i]; ++i) {
-        printf(".Lstr__%d:\n", i + 1);
-        printf("  .string \"%s\"\n\n", prog->str_literals[i]);
-    }
-
-    printf(".globl main\n\n");
-
-    for (i = 0; i < prog->funcs->node_len; ++i) {
-        AstNode* func = prog->funcs->node_items + i;
-        codegen_func(g, func);
-    }
-}
+// Currently the source code depends on the #include order.
+// clang-format off
+#include "std.h"
+#include "common.c"
+#include "preprocess.c"
+#include "tokenize.c"
+#include "ast.c"
+#include "parse.c"
+#include "codegen.c"
+#include "analyze.c"
+// clang-format on
 
 int main(int argc, char** argv) {
     if (argc == 1) {
diff --git a/parse.c b/parse.c
new file mode 100644
index 0000000..b056077
--- /dev/null
+++ b/parse.c
@@ -0,0 +1,1009 @@
+#define LVAR_MAX 32
+
+struct LocalVar {
+    String name;
+    Type* ty;
+};
+typedef struct LocalVar LocalVar;
+
+struct GlobalVar {
+    String name;
+    Type* ty;
+};
+typedef struct GlobalVar GlobalVar;
+
+struct Func {
+    String name;
+    Type* ty;
+};
+typedef struct Func Func;
+
+struct Parser {
+    Token* tokens;
+    int pos;
+    LocalVar* lvars;
+    int n_lvars;
+    GlobalVar* gvars;
+    int n_gvars;
+    Func* funcs;
+    int n_funcs;
+    AstNode* structs;
+    int n_structs;
+    AstNode* enums;
+    int n_enums;
+    AstNode* typedefs;
+    int n_typedefs;
+    char** str_literals;
+    int n_str_literals;
+};
+typedef struct Parser Parser;
+
+Parser* parser_new(Token* tokens) {
+    Parser* p = calloc(1, sizeof(Parser));
+    p->tokens = tokens;
+    p->gvars = calloc(128, sizeof(GlobalVar));
+    p->funcs = calloc(256, sizeof(Func));
+    p->structs = calloc(64, sizeof(AstNode));
+    p->enums = calloc(16, sizeof(AstNode));
+    p->typedefs = calloc(64, sizeof(AstNode));
+    p->str_literals = calloc(1024, sizeof(char*));
+    return p;
+}
+
+Token* peek_token(Parser* p) {
+    return p->tokens + p->pos;
+}
+
+Token* next_token(Parser* p) {
+    ++p->pos;
+    return p->tokens + p->pos - 1;
+}
+
+int eof(Parser* p) {
+    return peek_token(p)->kind != TokenKind_eof;
+}
+
+Token* expect(Parser* p, int expected) {
+    Token* t = next_token(p);
+    if (t->kind == expected) {
+        return t;
+    }
+
+    char* buf = calloc(1024, sizeof(char));
+    sprintf(buf, "expected '%s', but got '%s'", token_kind_stringify(expected), token_stringify(t));
+    fatal_error(buf);
+}
+
+int find_lvar(Parser* p, const String* name) {
+    int i;
+    for (i = 0; i < p->n_lvars; ++i) {
+        if (string_equals(&p->lvars[i].name, name)) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+int find_gvar(Parser* p, const String* name) {
+    int i;
+    for (i = 0; i < p->n_gvars; ++i) {
+        if (string_equals(&p->gvars[i].name, name)) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+int find_func(Parser* p, const String* name) {
+    int i;
+    for (i = 0; i < p->n_funcs; ++i) {
+        if (string_equals(&p->funcs[i].name, name)) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+int find_struct(Parser* p, const String* name) {
+    int i;
+    for (i = 0; i < p->n_structs; ++i) {
+        if (string_equals(&p->structs[i].name, name)) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+int find_enum(Parser* p, const String* name) {
+    int i;
+    for (i = 0; i < p->n_enums; ++i) {
+        if (string_equals(&p->enums[i].name, name)) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+int find_enum_member(Parser* p, const String* name) {
+    int i;
+    int j;
+    for (i = 0; i < p->n_enums; ++i) {
+        for (j = 0; j < p->enums[i].node_members->node_len; ++j) {
+            if (string_equals(&p->enums[i].node_members->node_items[j].name, name)) {
+                return i * 1000 + j;
+            }
+        }
+    }
+    return -1;
+}
+
+int find_typedef(Parser* p, const String* name) {
+    int i;
+    for (i = 0; i < p->n_typedefs; ++i) {
+        if (string_equals(&p->typedefs[i].name, name)) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+AstNode* parse_expr(Parser* p);
+AstNode* parse_stmt(Parser* p);
+
+String* parse_ident(Parser* p) {
+    return &expect(p, TokenKind_ident)->raw;
+}
+
+int register_str_literal(Parser* p, char* s) {
+    p->str_literals[p->n_str_literals] = s;
+    ++p->n_str_literals;
+    return p->n_str_literals;
+}
+
+AstNode* parse_primary_expr(Parser* p) {
+    Token* t = next_token(p);
+    AstNode* e;
+    char* buf;
+    if (t->kind == TokenKind_literal_int) {
+        return ast_new_int(atoi(string_to_cstr(&t->raw)));
+    } else if (t->kind == TokenKind_literal_str) {
+        e = ast_new(AstNodeKind_str_expr);
+        e->node_idx = register_str_literal(p, string_to_cstr(&t->raw));
+        return e;
+    } else if (t->kind == TokenKind_paren_l) {
+        e = parse_expr(p);
+        expect(p, TokenKind_paren_r);
+        return e;
+    } else if (t->kind == TokenKind_ident) {
+        String* name = &t->raw;
+
+        if (peek_token(p)->kind == TokenKind_paren_l) {
+            e = ast_new(AstNodeKind_func_call);
+            int func_idx = find_func(p, name);
+            if (func_idx == -1) {
+                buf = calloc(1024, sizeof(char));
+                sprintf(buf, "undefined function: %.*s", name->len, name->data);
+                fatal_error(buf);
+            }
+            e->name.data = name->data;
+            e->name.len = name->len;
+            e->ty = p->funcs[func_idx].ty;
+            return e;
+        }
+
+        int lvar_idx = find_lvar(p, name);
+        if (lvar_idx == -1) {
+            int gvar_idx = find_gvar(p, name);
+            if (gvar_idx == -1) {
+                int enum_member_idx = find_enum_member(p, name);
+                if (enum_member_idx == -1) {
+                    buf = calloc(1024, sizeof(char));
+                    sprintf(buf, "undefined variable: %.*s", name->len, name->data);
+                    fatal_error(buf);
+                }
+                int enum_idx = enum_member_idx / 1000;
+                int n = enum_member_idx % 1000;
+                e = ast_new_int(p->enums[enum_idx].node_members->node_items[n].node_int_value);
+                e->ty = type_new(TypeKind_enum);
+                e->ty->def = p->enums + enum_idx;
+                return e;
+            }
+            e = ast_new(AstNodeKind_gvar);
+            e->name.data = name->data;
+            e->name.len = name->len;
+            e->ty = p->gvars[gvar_idx].ty;
+            return e;
+        }
+
+        e = ast_new(AstNodeKind_lvar);
+        e->name.data = name->data;
+        e->name.len = name->len;
+        e->node_idx = lvar_idx;
+        e->ty = p->lvars[lvar_idx].ty;
+        return e;
+    } else {
+        buf = calloc(1024, sizeof(char));
+        sprintf(buf, "expected primary expression, but got '%s'", token_stringify(t));
+        fatal_error(buf);
+    }
+}
+
+AstNode* parse_arg_list(Parser* p) {
+    AstNode* list = ast_new_list(6);
+    while (peek_token(p)->kind != TokenKind_paren_r) {
+        AstNode* arg = parse_expr(p);
+        ast_append(list, arg);
+        if (peek_token(p)->kind == TokenKind_comma) {
+            next_token(p);
+        } else {
+            break;
+        }
+    }
+    if (list->node_len > 6) {
+        fatal_error("too many arguments");
+    }
+    return list;
+}
+
+AstNode* parse_postfix_expr(Parser* p) {
+    AstNode* ret = parse_primary_expr(p);
+    String* name;
+    while (1) {
+        TokenKind tk = peek_token(p)->kind;
+        if (tk == TokenKind_paren_l) {
+            next_token(p);
+            AstNode* args = parse_arg_list(p);
+            expect(p, TokenKind_paren_r);
+            ret->node_args = args;
+        } else if (tk == TokenKind_bracket_l) {
+            next_token(p);
+            AstNode* idx = parse_expr(p);
+            expect(p, TokenKind_bracket_r);
+            idx = ast_new_binary_expr(TokenKind_star, idx, ast_new_int(type_sizeof(ret->ty->to)));
+            ret = ast_new_deref_expr(ast_new_binary_expr(TokenKind_plus, ret, idx));
+        } else if (tk == TokenKind_dot) {
+            next_token(p);
+            name = parse_ident(p);
+            ret = ast_new_member_access_expr(ast_new_ref_expr(ret), name);
+        } else if (tk == TokenKind_arrow) {
+            next_token(p);
+            name = parse_ident(p);
+            ret = ast_new_member_access_expr(ret, name);
+        } else {
+            break;
+        }
+    }
+    return ret;
+}
+
+int is_type_token(Parser* p, Token* token) {
+    if (token->kind == TokenKind_keyword_int || token->kind == TokenKind_keyword_long ||
+        token->kind == TokenKind_keyword_char || token->kind == TokenKind_keyword_void ||
+        token->kind == TokenKind_keyword_enum || token->kind == TokenKind_keyword_struct ||
+        token->kind == TokenKind_keyword_const) {
+        return 1;
+    }
+    if (token->kind != TokenKind_ident) {
+        return 0;
+    }
+    return find_typedef(p, &token->raw) != -1;
+}
+
+Type* parse_type(Parser* p) {
+    Token* t = next_token(p);
+    char* buf;
+    String* name;
+    if (t->kind == TokenKind_keyword_const) {
+        t = next_token(p);
+    }
+    if (!is_type_token(p, t)) {
+        buf = calloc(1024, sizeof(char));
+        sprintf(buf, "parse_type: expected type, but got '%s'", token_stringify(t));
+        fatal_error(buf);
+    }
+    Type* ty;
+    if (t->kind == TokenKind_ident) {
+        int typedef_idx = find_typedef(p, &t->raw);
+        if (typedef_idx == -1) {
+            buf = calloc(1024, sizeof(char));
+            sprintf(buf, "parse_type: unknown typedef, %.*s", t->raw.len, t->raw.data);
+            fatal_error(buf);
+        }
+        ty = p->typedefs[typedef_idx].ty;
+    } else {
+        ty = type_new(TypeKind_unknown);
+        if (t->kind == TokenKind_keyword_int) {
+            ty->kind = TypeKind_int;
+        } else if (t->kind == TokenKind_keyword_long) {
+            ty->kind = TypeKind_long;
+        } else if (t->kind == TokenKind_keyword_char) {
+            ty->kind = TypeKind_char;
+        } else if (t->kind == TokenKind_keyword_void) {
+            ty->kind = TypeKind_void;
+        } else if (t->kind == TokenKind_keyword_enum) {
+            ty->kind = TypeKind_enum;
+            name = parse_ident(p);
+            int enum_idx = find_enum(p, name);
+            if (enum_idx == -1) {
+                buf = calloc(1024, sizeof(char));
+                sprintf(buf, "parse_type: unknown enum, %.*s", name->len, name->data);
+                fatal_error(buf);
+            }
+            ty->def = p->enums + enum_idx;
+        } else if (t->kind == TokenKind_keyword_struct) {
+            ty->kind = TypeKind_struct;
+            name = parse_ident(p);
+            int struct_idx = find_struct(p, name);
+            if (struct_idx == -1) {
+                buf = calloc(1024, sizeof(char));
+                sprintf(buf, "parse_type: unknown struct, %.*s", name->len, name->data);
+                fatal_error(buf);
+            }
+            ty->def = p->structs + struct_idx;
+        } else {
+            unreachable();
+        }
+    }
+    while (1) {
+        if (peek_token(p)->kind == TokenKind_star) {
+            next_token(p);
+            ty = type_new_ptr(ty);
+        } else {
+            break;
+        }
+    }
+    return ty;
+}
+
+AstNode* parse_prefix_expr(Parser* p) {
+    AstNode* operand;
+    TokenKind op = peek_token(p)->kind;
+    if (op == TokenKind_minus) {
+        next_token(p);
+        operand = parse_prefix_expr(p);
+        return ast_new_binary_expr(op, ast_new_int(0), operand);
+    } else if (op == TokenKind_not) {
+        next_token(p);
+        operand = parse_prefix_expr(p);
+        return ast_new_unary_expr(op, operand);
+    } else if (op == TokenKind_and) {
+        next_token(p);
+        operand = parse_prefix_expr(p);
+        return ast_new_ref_expr(operand);
+    } else if (op == TokenKind_star) {
+        next_token(p);
+        operand = parse_prefix_expr(p);
+        return ast_new_deref_expr(operand);
+    } else if (op == TokenKind_plusplus) {
+        next_token(p);
+        operand = parse_prefix_expr(p);
+        return ast_new_assign_add_expr(operand, ast_new_int(1));
+    } else if (op == TokenKind_minusminus) {
+        next_token(p);
+        operand = parse_prefix_expr(p);
+        return ast_new_assign_sub_expr(operand, ast_new_int(1));
+    } else if (op == TokenKind_keyword_sizeof) {
+        next_token(p);
+        expect(p, TokenKind_paren_l);
+        Type* ty = parse_type(p);
+        expect(p, TokenKind_paren_r);
+        return ast_new_int(type_sizeof(ty));
+    }
+    return parse_postfix_expr(p);
+}
+
+AstNode* parse_multiplicative_expr(Parser* p) {
+    AstNode* lhs = parse_prefix_expr(p);
+    while (1) {
+        TokenKind op = peek_token(p)->kind;
+        if (op == TokenKind_star || op == TokenKind_slash || op == TokenKind_percent) {
+            next_token(p);
+            AstNode* rhs = parse_prefix_expr(p);
+            lhs = ast_new_binary_expr(op, lhs, rhs);
+        } else {
+            break;
+        }
+    }
+    return lhs;
+}
+
+AstNode* parse_additive_expr(Parser* p) {
+    AstNode* lhs = parse_multiplicative_expr(p);
+    AstNode* rhs;
+    while (1) {
+        TokenKind op = peek_token(p)->kind;
+        if (op == TokenKind_plus) {
+            next_token(p);
+            rhs = parse_multiplicative_expr(p);
+            if (lhs->ty->kind == TypeKind_ptr) {
+                lhs = ast_new_binary_expr(
+                    op, lhs, ast_new_binary_expr(TokenKind_star, rhs, ast_new_int(type_sizeof(lhs->ty->to))));
+            } else if (rhs->ty->kind == TypeKind_ptr) {
+                lhs = ast_new_binary_expr(
+                    op, ast_new_binary_expr(TokenKind_star, lhs, ast_new_int(type_sizeof(rhs->ty->to))), rhs);
+            } else {
+                lhs = ast_new_binary_expr(op, lhs, rhs);
+            }
+        } else if (op == TokenKind_minus) {
+            next_token(p);
+            rhs = parse_multiplicative_expr(p);
+            if (lhs->ty->kind == TypeKind_ptr) {
+                if (rhs->ty->kind == TypeKind_ptr) {
+                    // (a - b) / sizeof(a)
+                    lhs = ast_new_binary_expr(TokenKind_slash, ast_new_binary_expr(op, lhs, rhs),
+                                              ast_new_int(type_sizeof(lhs->ty->to)));
+                } else {
+                    // a - b*sizeof(a)
+                    lhs = ast_new_binary_expr(
+                        op, lhs, ast_new_binary_expr(TokenKind_star, rhs, ast_new_int(type_sizeof(lhs->ty->to))));
+                }
+            } else {
+                lhs = ast_new_binary_expr(op, lhs, rhs);
+            }
+        } else {
+            break;
+        }
+    }
+    return lhs;
+}
+
+AstNode* parse_relational_expr(Parser* p) {
+    AstNode* lhs = parse_additive_expr(p);
+    AstNode* rhs;
+    while (1) {
+        TokenKind op = peek_token(p)->kind;
+        if (op == TokenKind_lt || op == TokenKind_le) {
+            next_token(p);
+            rhs = parse_additive_expr(p);
+            lhs = ast_new_binary_expr(op, lhs, rhs);
+        } else if (op == TokenKind_gt) {
+            next_token(p);
+            rhs = parse_additive_expr(p);
+            lhs = ast_new_binary_expr(TokenKind_lt, rhs, lhs);
+        } else if (op == TokenKind_ge) {
+            next_token(p);
+            rhs = parse_additive_expr(p);
+            lhs = ast_new_binary_expr(TokenKind_le, rhs, lhs);
+        } else {
+            break;
+        }
+    }
+    return lhs;
+}
+
+AstNode* parse_equality_expr(Parser* p) {
+    AstNode* lhs = parse_relational_expr(p);
+    while (1) {
+        TokenKind op = peek_token(p)->kind;
+        if (op == TokenKind_eq || op == TokenKind_ne) {
+            next_token(p);
+            AstNode* rhs = parse_relational_expr(p);
+            lhs = ast_new_binary_expr(op, lhs, rhs);
+        } else {
+            break;
+        }
+    }
+    return lhs;
+}
+
+AstNode* parse_logical_and_expr(Parser* p) {
+    AstNode* lhs = parse_equality_expr(p);
+    while (1) {
+        TokenKind op = peek_token(p)->kind;
+        if (op == TokenKind_andand) {
+            next_token(p);
+            AstNode* rhs = parse_equality_expr(p);
+            AstNode* e = ast_new(AstNodeKind_logical_expr);
+            e->node_op = op;
+            e->node_lhs = lhs;
+            e->node_rhs = rhs;
+            e->ty = type_new(TypeKind_int);
+            lhs = e;
+        } else {
+            break;
+        }
+    }
+    return lhs;
+}
+
+AstNode* parse_logical_or_expr(Parser* p) {
+    AstNode* lhs = parse_logical_and_expr(p);
+    while (1) {
+        TokenKind op = peek_token(p)->kind;
+        if (op == TokenKind_oror) {
+            next_token(p);
+            AstNode* rhs = parse_logical_and_expr(p);
+            AstNode* e = ast_new(AstNodeKind_logical_expr);
+            e->node_op = op;
+            e->node_lhs = lhs;
+            e->node_rhs = rhs;
+            e->ty = type_new(TypeKind_int);
+            lhs = e;
+        } else {
+            break;
+        }
+    }
+    return lhs;
+}
+
+AstNode* parse_assignment_expr(Parser* p) {
+    AstNode* lhs = parse_logical_or_expr(p);
+    AstNode* rhs;
+    while (1) {
+        TokenKind op = peek_token(p)->kind;
+        if (op == TokenKind_assign) {
+            next_token(p);
+            rhs = parse_logical_or_expr(p);
+            lhs = ast_new_assign_expr(op, lhs, rhs);
+        } else if (op == TokenKind_assign_add) {
+            next_token(p);
+            rhs = parse_logical_or_expr(p);
+            lhs = ast_new_assign_add_expr(lhs, rhs);
+        } else if (op == TokenKind_assign_sub) {
+            next_token(p);
+            rhs = parse_logical_or_expr(p);
+            lhs = ast_new_assign_sub_expr(lhs, rhs);
+        } else {
+            break;
+        }
+    }
+    return lhs;
+}
+
+AstNode* parse_expr(Parser* p) {
+    return parse_assignment_expr(p);
+}
+
+AstNode* parse_return_stmt(Parser* p) {
+    expect(p, TokenKind_keyword_return);
+    if (peek_token(p)->kind == TokenKind_semicolon) {
+        next_token(p);
+        return ast_new(AstNodeKind_return_stmt);
+    }
+
+    AstNode* expr = parse_expr(p);
+    expect(p, TokenKind_semicolon);
+
+    AstNode* ret = ast_new(AstNodeKind_return_stmt);
+    ret->node_expr = expr;
+    return ret;
+}
+
+AstNode* parse_if_stmt(Parser* p) {
+    expect(p, TokenKind_keyword_if);
+    expect(p, TokenKind_paren_l);
+    AstNode* cond = parse_expr(p);
+    expect(p, TokenKind_paren_r);
+    AstNode* then_body = parse_stmt(p);
+    AstNode* else_body = NULL;
+    if (peek_token(p)->kind == TokenKind_keyword_else) {
+        next_token(p);
+        else_body = parse_stmt(p);
+    }
+
+    AstNode* stmt = ast_new(AstNodeKind_if_stmt);
+    stmt->node_cond = cond;
+    stmt->node_then = then_body;
+    stmt->node_else = else_body;
+    return stmt;
+}
+
+AstNode* parse_for_stmt(Parser* p) {
+    expect(p, TokenKind_keyword_for);
+    expect(p, TokenKind_paren_l);
+    AstNode* init = NULL;
+    AstNode* cond = NULL;
+    AstNode* update = NULL;
+    if (peek_token(p)->kind != TokenKind_semicolon) {
+        init = parse_expr(p);
+    }
+    expect(p, TokenKind_semicolon);
+    if (peek_token(p)->kind != TokenKind_semicolon) {
+        cond = parse_expr(p);
+    } else {
+        cond = ast_new_int(1);
+    }
+    expect(p, TokenKind_semicolon);
+    if (peek_token(p)->kind != TokenKind_paren_r) {
+        update = parse_expr(p);
+    }
+    expect(p, TokenKind_paren_r);
+    AstNode* body = parse_stmt(p);
+
+    AstNode* stmt = ast_new(AstNodeKind_for_stmt);
+    stmt->node_cond = cond;
+    stmt->node_init = init;
+    stmt->node_update = update;
+    stmt->node_body = body;
+    return stmt;
+}
+
+AstNode* parse_while_stmt(Parser* p) {
+    expect(p, TokenKind_keyword_while);
+    expect(p, TokenKind_paren_l);
+    AstNode* cond = parse_expr(p);
+    expect(p, TokenKind_paren_r);
+    AstNode* body = parse_stmt(p);
+
+    AstNode* stmt = ast_new(AstNodeKind_for_stmt);
+    stmt->node_cond = cond;
+    stmt->node_body = body;
+    return stmt;
+}
+
+AstNode* parse_do_while_stmt(Parser* p) {
+    expect(p, TokenKind_keyword_do);
+    AstNode* body = parse_stmt(p);
+    expect(p, TokenKind_keyword_while);
+    expect(p, TokenKind_paren_l);
+    AstNode* cond = parse_expr(p);
+    expect(p, TokenKind_paren_r);
+    expect(p, TokenKind_semicolon);
+
+    AstNode* stmt = ast_new(AstNodeKind_do_while_stmt);
+    stmt->node_cond = cond;
+    stmt->node_body = body;
+    return stmt;
+}
+
+AstNode* parse_break_stmt(Parser* p) {
+    expect(p, TokenKind_keyword_break);
+    expect(p, TokenKind_semicolon);
+    return ast_new(AstNodeKind_break_stmt);
+}
+
+AstNode* parse_continue_stmt(Parser* p) {
+    expect(p, TokenKind_keyword_continue);
+    expect(p, TokenKind_semicolon);
+    return ast_new(AstNodeKind_continue_stmt);
+}
+
+AstNode* parse_var_decl(Parser* p) {
+    Type* ty = parse_type(p);
+    if (!type_is_unsized(ty)) {
+        fatal_error("parse_var_decl: invalid type for variable");
+    }
+    String* name = parse_ident(p);
+
+    AstNode* init = NULL;
+    if (peek_token(p)->kind == TokenKind_assign) {
+        next_token(p);
+        init = parse_expr(p);
+    }
+    expect(p, TokenKind_semicolon);
+
+    if (find_lvar(p, name) != -1 || find_gvar(p, name) != -1) {
+        char* buf = calloc(1024, sizeof(char));
+        sprintf(buf, "parse_var_decl: %.*s redeclared", name->len, name->data);
+        fatal_error(buf);
+    }
+    p->lvars[p->n_lvars].name.data = name->data;
+    p->lvars[p->n_lvars].name.len = name->len;
+    p->lvars[p->n_lvars].ty = ty;
+    ++p->n_lvars;
+
+    AstNode* ret;
+    if (init) {
+        AstNode* lhs = ast_new(AstNodeKind_lvar);
+        lhs->name.data = name->data;
+        lhs->name.len = name->len;
+        lhs->node_idx = p->n_lvars - 1;
+        lhs->ty = ty;
+        AstNode* assign = ast_new_assign_expr(TokenKind_assign, lhs, init);
+        ret = ast_new(AstNodeKind_expr_stmt);
+        ret->node_expr = assign;
+    } else {
+        ret = ast_new(AstNodeKind_lvar_decl);
+    }
+    return ret;
+}
+
+AstNode* parse_expr_stmt(Parser* p) {
+    AstNode* e = parse_expr(p);
+    expect(p, TokenKind_semicolon);
+    AstNode* stmt = ast_new(AstNodeKind_expr_stmt);
+    stmt->node_expr = e;
+    return stmt;
+}
+
+AstNode* parse_block_stmt(Parser* p) {
+    AstNode* list = ast_new_list(1024);
+    expect(p, TokenKind_brace_l);
+    while (peek_token(p)->kind != TokenKind_brace_r) {
+        AstNode* stmt = parse_stmt(p);
+        ast_append(list, stmt);
+    }
+    expect(p, TokenKind_brace_r);
+    return list;
+}
+
+AstNode* parse_stmt(Parser* p) {
+    Token* t = peek_token(p);
+    if (t->kind == TokenKind_keyword_return) {
+        return parse_return_stmt(p);
+    } else if (t->kind == TokenKind_keyword_if) {
+        return parse_if_stmt(p);
+    } else if (t->kind == TokenKind_keyword_for) {
+        return parse_for_stmt(p);
+    } else if (t->kind == TokenKind_keyword_while) {
+        return parse_while_stmt(p);
+    } else if (t->kind == TokenKind_keyword_do) {
+        return parse_do_while_stmt(p);
+    } else if (t->kind == TokenKind_keyword_break) {
+        return parse_break_stmt(p);
+    } else if (t->kind == TokenKind_keyword_continue) {
+        return parse_continue_stmt(p);
+    } else if (t->kind == TokenKind_brace_l) {
+        return parse_block_stmt(p);
+    } else if (is_type_token(p, t)) {
+        return parse_var_decl(p);
+    } else {
+        return parse_expr_stmt(p);
+    }
+}
+
+void enter_func(Parser* p) {
+    p->lvars = calloc(LVAR_MAX, sizeof(LocalVar));
+    p->n_lvars = 0;
+}
+
+void register_params(Parser* p, AstNode* params) {
+    int i;
+    for (i = 0; i < params->node_len; ++i) {
+        AstNode* param = params->node_items + i;
+        p->lvars[p->n_lvars].name.data = param->name.data;
+        p->lvars[p->n_lvars].name.len = param->name.len;
+        p->lvars[p->n_lvars].ty = param->ty;
+        ++p->n_lvars;
+    }
+}
+
+void register_func(Parser* p, const String* name, Type* ty) {
+    p->funcs[p->n_funcs].name.data = name->data;
+    p->funcs[p->n_funcs].name.len = name->len;
+    p->funcs[p->n_funcs].ty = ty;
+    ++p->n_funcs;
+}
+
+AstNode* parse_param(Parser* p) {
+    Type* ty = parse_type(p);
+    String* name = NULL;
+    TokenKind tk = peek_token(p)->kind;
+    if (tk != TokenKind_comma && tk != TokenKind_paren_r) {
+        name = parse_ident(p);
+    }
+    AstNode* param = ast_new(AstNodeKind_param);
+    param->ty = ty;
+    if (name) {
+        param->name.data = name->data;
+        param->name.len = name->len;
+    }
+    return param;
+}
+
+AstNode* parse_param_list(Parser* p) {
+    int has_void = 0;
+    AstNode* list = ast_new_list(6);
+    while (peek_token(p)->kind != TokenKind_paren_r) {
+        if (peek_token(p)->kind == TokenKind_ellipsis) {
+            next_token(p);
+            break;
+        }
+        AstNode* param = parse_param(p);
+        has_void = has_void || param->ty->kind == TypeKind_void;
+        ast_append(list, param);
+        if (peek_token(p)->kind == TokenKind_comma) {
+            next_token(p);
+        } else {
+            break;
+        }
+    }
+    if (list->node_len > 6) {
+        fatal_error("too many parameters");
+    }
+    if (has_void) {
+        if (list->node_len != 1) {
+            fatal_error("invalid use of void param");
+        }
+        list->node_len = 0;
+    }
+    return list;
+}
+
+AstNode* parse_func_decl_or_def(Parser* p) {
+    Type* ty = parse_type(p);
+    String* name = parse_ident(p);
+    register_func(p, name, ty);
+    expect(p, TokenKind_paren_l);
+    AstNode* params = parse_param_list(p);
+    expect(p, TokenKind_paren_r);
+    if (peek_token(p)->kind == TokenKind_semicolon) {
+        next_token(p);
+        return ast_new(AstNodeKind_func_decl);
+    }
+    enter_func(p);
+    register_params(p, params);
+    AstNode* body = parse_block_stmt(p);
+    AstNode* func = ast_new(AstNodeKind_func_def);
+    func->ty = ty;
+    func->name.data = name->data;
+    func->name.len = name->len;
+    func->node_params = params;
+    func->node_body = body;
+    return func;
+}
+
+AstNode* parse_struct_member(Parser* p) {
+    Type* ty = parse_type(p);
+    String* name = parse_ident(p);
+    expect(p, TokenKind_semicolon);
+    AstNode* member = ast_new(AstNodeKind_struct_member);
+    member->name.data = name->data;
+    member->name.len = name->len;
+    member->ty = ty;
+    return member;
+}
+
+AstNode* parse_struct_members(Parser* p) {
+    AstNode* list = ast_new_list(16);
+    while (peek_token(p)->kind != TokenKind_brace_r) {
+        AstNode* member = parse_struct_member(p);
+        ast_append(list, member);
+    }
+    return list;
+}
+
+AstNode* parse_struct_decl_or_def(Parser* p) {
+    expect(p, TokenKind_keyword_struct);
+    String* name = parse_ident(p);
+
+    if (peek_token(p)->kind != TokenKind_semicolon && peek_token(p)->kind != TokenKind_brace_l) {
+        p->pos = p->pos - 2;
+        return parse_func_decl_or_def(p);
+    }
+
+    int struct_idx = find_struct(p, name);
+    if (struct_idx == -1) {
+        struct_idx = p->n_structs;
+        p->structs[struct_idx].kind = AstNodeKind_struct_def;
+        p->structs[struct_idx].name.data = name->data;
+        p->structs[struct_idx].name.len = name->len;
+        ++p->n_structs;
+    }
+    if (peek_token(p)->kind == TokenKind_semicolon) {
+        next_token(p);
+        return ast_new(AstNodeKind_struct_decl);
+    }
+    if (p->structs[struct_idx].node_members) {
+        char* buf = calloc(1024, sizeof(char));
+        sprintf(buf, "parse_struct_decl_or_def: struct %.*s redefined", name->len, name->data);
+        fatal_error(buf);
+    }
+    expect(p, TokenKind_brace_l);
+    AstNode* members = parse_struct_members(p);
+    expect(p, TokenKind_brace_r);
+    expect(p, TokenKind_semicolon);
+    p->structs[struct_idx].node_members = members;
+    return p->structs + struct_idx;
+}
+
+AstNode* parse_enum_member(Parser* p) {
+    String* name = parse_ident(p);
+    AstNode* member = ast_new(AstNodeKind_enum_member);
+    member->name.data = name->data;
+    member->name.len = name->len;
+    return member;
+}
+
+AstNode* parse_enum_members(Parser* p) {
+    int next_value = 0;
+    AstNode* list = ast_new_list(256);
+    while (peek_token(p)->kind != TokenKind_brace_r) {
+        AstNode* member = parse_enum_member(p);
+        member->node_int_value = next_value;
+        ++next_value;
+        ast_append(list, member);
+        if (peek_token(p)->kind != TokenKind_comma) {
+            break;
+        }
+        next_token(p);
+    }
+    return list;
+}
+
+AstNode* parse_enum_def(Parser* p) {
+    expect(p, TokenKind_keyword_enum);
+    String* name = parse_ident(p);
+
+    if (peek_token(p)->kind != TokenKind_brace_l) {
+        p->pos = p->pos - 2;
+        return parse_func_decl_or_def(p);
+    }
+
+    int enum_idx = find_enum(p, name);
+    if (enum_idx == -1) {
+        enum_idx = p->n_enums;
+        p->enums[enum_idx].kind = AstNodeKind_enum_def;
+        p->enums[enum_idx].name.data = name->data;
+        p->enums[enum_idx].name.len = name->len;
+        ++p->n_enums;
+    } else {
+        char* buf = calloc(1024, sizeof(char));
+        sprintf(buf, "parse_enum_def: enum %.*s redefined", name->len, name->data);
+        fatal_error(buf);
+    }
+    expect(p, TokenKind_brace_l);
+    AstNode* members = parse_enum_members(p);
+    expect(p, TokenKind_brace_r);
+    expect(p, TokenKind_semicolon);
+    p->enums[enum_idx].node_members = members;
+    return p->enums + enum_idx;
+}
+
+AstNode* parse_typedef_decl(Parser* p) {
+    expect(p, TokenKind_keyword_typeof);
+    Type* ty = parse_type(p);
+    String* name = parse_ident(p);
+    expect(p, TokenKind_semicolon);
+    AstNode* decl = ast_new(AstNodeKind_typedef_decl);
+    decl->name.data = name->data;
+    decl->name.len = name->len;
+    decl->ty = ty;
+    p->typedefs[p->n_typedefs].name.data = name->data;
+    p->typedefs[p->n_typedefs].name.len = name->len;
+    p->typedefs[p->n_typedefs].ty = ty;
+    ++p->n_typedefs;
+    return decl;
+}
+
+AstNode* parse_extern_var_decl(Parser* p) {
+    expect(p, TokenKind_keyword_extern);
+    Type* ty = parse_type(p);
+    if (!type_is_unsized(ty)) {
+        fatal_error("parse_extern_var_decl: invalid type for variable");
+    }
+    String* name = parse_ident(p);
+    expect(p, TokenKind_semicolon);
+
+    if (find_lvar(p, name) != -1 || find_gvar(p, name) != -1) {
+        char* buf = calloc(1024, sizeof(char));
+        sprintf(buf, "parse_extern_var_decl: %.*s redeclared", name->len, name->data);
+        fatal_error(buf);
+    }
+    p->gvars[p->n_gvars].name.data = name->data;
+    p->gvars[p->n_gvars].name.len = name->len;
+    p->gvars[p->n_gvars].ty = ty;
+    ++p->n_gvars;
+
+    return ast_new(AstNodeKind_gvar_decl);
+}
+
+AstNode* parse_toplevel(Parser* p) {
+    TokenKind tk = peek_token(p)->kind;
+    if (tk == TokenKind_keyword_struct) {
+        return parse_struct_decl_or_def(p);
+    } else if (tk == TokenKind_keyword_enum) {
+        return parse_enum_def(p);
+    } else if (tk == TokenKind_keyword_typeof) {
+        return parse_typedef_decl(p);
+    } else if (tk == TokenKind_keyword_extern) {
+        return parse_extern_var_decl(p);
+    } else {
+        return parse_func_decl_or_def(p);
+    }
+}
+
+Program* parse(Token* tokens) {
+    Parser* p = parser_new(tokens);
+    AstNode* funcs = ast_new_list(1024);
+    while (eof(p)) {
+        AstNode* n = parse_toplevel(p);
+        if (n->kind == AstNodeKind_func_def) {
+            ast_append(funcs, n);
+        }
+    }
+    Program* prog = calloc(1, sizeof(Program));
+    prog->funcs = funcs;
+    prog->str_literals = p->str_literals;
+    return prog;
+}
diff --git a/preprocess.c b/preprocess.c
new file mode 100644
index 0000000..202ff40
--- /dev/null
+++ b/preprocess.c
@@ -0,0 +1,431 @@
+enum PpTokenKind {
+    PpTokenKind_eof,
+
+    PpTokenKind_header_name,
+    PpTokenKind_identifier,
+    PpTokenKind_pp_number,
+    PpTokenKind_character_constant,
+    PpTokenKind_string_literal,
+    PpTokenKind_punctuator,
+    PpTokenKind_other,
+    PpTokenKind_whitespace,
+};
+typedef enum PpTokenKind PpTokenKind;
+
+struct PpToken {
+    PpTokenKind kind;
+    String raw;
+};
+typedef struct PpToken PpToken;
+
+struct PpDefine {
+    String name;
+    PpToken* tokens;
+};
+typedef struct PpDefine PpDefine;
+
+struct PpDefines {
+    PpDefine* data;
+    size_t len;
+};
+typedef struct PpDefines PpDefines;
+
+struct Preprocessor {
+    char* src;
+    int pos;
+    PpToken* pp_tokens;
+    int n_pp_tokens;
+    PpDefines* pp_defines;
+    int include_depth;
+};
+typedef struct Preprocessor Preprocessor;
+
+PpToken* do_preprocess(char* src, int depth, PpDefines* pp_defines);
+
+PpDefines* pp_defines_new() {
+    PpDefines* pp_defines = calloc(1, sizeof(PpDefines));
+    pp_defines->data = calloc(1024, sizeof(PpDefine));
+    return pp_defines;
+}
+
+Preprocessor* preprocessor_new(char* src, int include_depth, PpDefines* pp_defines) {
+    if (include_depth >= 32) {
+        fatal_error("include depth limit exceeded");
+    }
+
+    Preprocessor* pp = calloc(1, sizeof(Preprocessor));
+    pp->src = src;
+    pp->pp_tokens = calloc(1024 * 1024, sizeof(PpToken));
+    pp->pp_defines = pp_defines;
+    pp->include_depth = include_depth;
+
+    return pp;
+}
+
+int find_pp_define(Preprocessor* pp, String* name) {
+    int i;
+    for (i = 0; i < pp->pp_defines->len; ++i) {
+        if (string_equals(&pp->pp_defines->data[i].name, name)) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+void pp_tokenize_all(Preprocessor* pp) {
+    char* buf;
+    int ch;
+    int start;
+    while (pp->src[pp->pos]) {
+        PpToken* tok = pp->pp_tokens + pp->n_pp_tokens;
+        char c = pp->src[pp->pos];
+        ++pp->pos;
+        if (c == '(') {
+            tok->kind = PpTokenKind_punctuator;
+            tok->raw.len = 1;
+            tok->raw.data = pp->src + pp->pos - tok->raw.len;
+        } else if (c == ')') {
+            tok->kind = PpTokenKind_punctuator;
+            tok->raw.len = 1;
+            tok->raw.data = pp->src + pp->pos - tok->raw.len;
+        } else if (c == '{') {
+            tok->kind = PpTokenKind_punctuator;
+            tok->raw.len = 1;
+            tok->raw.data = pp->src + pp->pos - tok->raw.len;
+        } else if (c == '}') {
+            tok->kind = PpTokenKind_punctuator;
+            tok->raw.len = 1;
+            tok->raw.data = pp->src + pp->pos - tok->raw.len;
+        } else if (c == '[') {
+            tok->kind = PpTokenKind_punctuator;
+            tok->raw.len = 1;
+            tok->raw.data = pp->src + pp->pos - tok->raw.len;
+        } else if (c == ']') {
+            tok->kind = PpTokenKind_punctuator;
+            tok->raw.len = 1;
+            tok->raw.data = pp->src + pp->pos - tok->raw.len;
+        } else if (c == ',') {
+            tok->kind = PpTokenKind_punctuator;
+            tok->raw.len = 1;
+            tok->raw.data = pp->src + pp->pos - tok->raw.len;
+        } else if (c == ';') {
+            tok->kind = PpTokenKind_punctuator;
+            tok->raw.len = 1;
+            tok->raw.data = pp->src + pp->pos - tok->raw.len;
+        } else if (c == '+') {
+            if (pp->src[pp->pos] == '=') {
+                ++pp->pos;
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 2;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            } else if (pp->src[pp->pos] == '+') {
+                ++pp->pos;
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 2;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            } else {
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 1;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            }
+        } else if (c == '|') {
+            ++pp->pos;
+            tok->kind = PpTokenKind_punctuator;
+            tok->raw.len = 2;
+            tok->raw.data = pp->src + pp->pos - tok->raw.len;
+        } else if (c == '&') {
+            if (pp->src[pp->pos] == '&') {
+                ++pp->pos;
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 2;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            } else {
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 1;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            }
+        } else if (c == '-') {
+            if (pp->src[pp->pos] == '>') {
+                ++pp->pos;
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 2;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            } else if (pp->src[pp->pos] == '=') {
+                ++pp->pos;
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 2;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            } else if (pp->src[pp->pos] == '-') {
+                ++pp->pos;
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 2;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            } else {
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 1;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            }
+        } else if (c == '*') {
+            tok->kind = PpTokenKind_punctuator;
+            tok->raw.len = 1;
+            tok->raw.data = pp->src + pp->pos - tok->raw.len;
+        } else if (c == '/') {
+            if (pp->src[pp->pos] == '/') {
+                start = pp->pos - 1;
+                ++pp->pos;
+                while (pp->src[pp->pos] && pp->src[pp->pos] != '\n' && pp->src[pp->pos] != '\r') {
+                    ++pp->pos;
+                }
+                tok->kind = PpTokenKind_whitespace;
+                tok->raw.len = pp->pos - start;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            } else if (pp->src[pp->pos] == '*') {
+                fatal_error("unimplemented");
+            } else {
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 1;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            }
+        } else if (c == '%') {
+            tok->kind = PpTokenKind_punctuator;
+            tok->raw.len = 1;
+            tok->raw.data = pp->src + pp->pos - tok->raw.len;
+        } else if (c == '.') {
+            if (pp->src[pp->pos] == '.') {
+                ++pp->pos;
+                if (pp->src[pp->pos] == '.') {
+                    ++pp->pos;
+                    tok->kind = PpTokenKind_punctuator;
+                    tok->raw.len = 3;
+                    tok->raw.data = pp->src + pp->pos - tok->raw.len;
+                } else {
+                    --pp->pos;
+                    tok->kind = PpTokenKind_punctuator;
+                    tok->raw.len = 1;
+                    tok->raw.data = pp->src + pp->pos - tok->raw.len;
+                }
+            } else {
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 1;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            }
+        } else if (c == '!') {
+            if (pp->src[pp->pos] == '=') {
+                ++pp->pos;
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 2;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            } else {
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 1;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            }
+        } else if (c == '=') {
+            if (pp->src[pp->pos] == '=') {
+                ++pp->pos;
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 2;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            } else {
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 1;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            }
+        } else if (c == '<') {
+            if (pp->src[pp->pos] == '=') {
+                ++pp->pos;
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 2;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            } else {
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 1;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            }
+        } else if (c == '>') {
+            if (pp->src[pp->pos] == '=') {
+                ++pp->pos;
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 2;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            } else {
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 1;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            }
+        } else if (c == '#') {
+            if (pp->src[pp->pos] == '#') {
+                ++pp->pos;
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 2;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            } else {
+                tok->kind = PpTokenKind_punctuator;
+                tok->raw.len = 1;
+                tok->raw.data = pp->src + pp->pos - tok->raw.len;
+            }
+        } else if (c == '\'') {
+            start = pp->pos - 1;
+            if (pp->src[pp->pos] == '\\') {
+                ++pp->pos;
+            }
+            pp->pos += 2;
+            tok->kind = PpTokenKind_character_constant;
+            tok->raw.data = pp->src + start;
+            tok->raw.len = pp->pos - start;
+        } else if (c == '"') {
+            start = pp->pos - 1;
+            while (1) {
+                ch = pp->src[pp->pos];
+                if (ch == '\\') {
+                    ++pp->pos;
+                } else if (ch == '"') {
+                    break;
+                }
+                ++pp->pos;
+            }
+            ++pp->pos;
+            tok->kind = PpTokenKind_string_literal;
+            tok->raw.data = pp->src + start;
+            tok->raw.len = pp->pos - start;
+        } else if (isdigit(c)) {
+            --pp->pos;
+            start = pp->pos;
+            while (isdigit(pp->src[pp->pos])) {
+                ++pp->pos;
+            }
+            tok->kind = PpTokenKind_pp_number;
+            tok->raw.data = pp->src + start;
+            tok->raw.len = pp->pos - start;
+        } else if (isalpha(c) || c == '_') {
+            --pp->pos;
+            start = pp->pos;
+            while (isalnum(pp->src[pp->pos]) || pp->src[pp->pos] == '_') {
+                ++pp->pos;
+            }
+            tok->raw.data = pp->src + start;
+            tok->raw.len = pp->pos - start;
+            tok->kind = PpTokenKind_identifier;
+        } else if (isspace(c)) {
+            tok->raw.data = pp->src;
+            tok->raw.len = 1;
+            tok->kind = PpTokenKind_whitespace;
+        } else {
+            tok->raw.data = pp->src;
+            tok->raw.len = 1;
+            tok->kind = PpTokenKind_other;
+        }
+        ++pp->n_pp_tokens;
+    }
+}
+
+void process_pp_directives(Preprocessor* pp) {
+    PpToken* tok = pp->pp_tokens;
+    PpToken* define_dest;
+    while (tok->kind != PpTokenKind_eof) {
+        // TODO: check if the token is at the beginning of line.
+        // TODO: check if skipped whitespaces do not contain line breaks.
+        if (tok->kind == PpTokenKind_punctuator && string_equals_cstr(&tok->raw, "#")) {
+            PpToken* tok2 = tok + 1;
+            while (tok2->kind != PpTokenKind_eof && tok2->kind == PpTokenKind_whitespace)
+                ++tok2;
+            if (tok2->kind == PpTokenKind_identifier && string_equals_cstr(&tok2->raw, "define")) {
+                ++tok2;
+                while (tok2->kind != PpTokenKind_eof && tok2->kind == PpTokenKind_whitespace)
+                    ++tok2;
+                if (tok2->kind == PpTokenKind_identifier) {
+                    PpToken* define_name = tok2;
+                    ++tok2;
+                    while (tok2->kind != PpTokenKind_eof && tok2->kind == PpTokenKind_whitespace)
+                        ++tok2;
+                    if (tok2->kind == PpTokenKind_identifier || tok2->kind == PpTokenKind_pp_number) {
+                        define_dest = tok2;
+
+                        PpDefine* pp_define = pp->pp_defines->data + pp->pp_defines->len;
+                        pp_define->name.len = define_name->raw.len;
+                        pp_define->name.data = define_name->raw.data;
+                        pp_define->tokens = calloc(1, sizeof(PpToken));
+                        pp_define->tokens[0].kind = define_dest->kind;
+                        pp_define->tokens[0].raw.len = define_dest->raw.len;
+                        pp_define->tokens[0].raw.data = define_dest->raw.data;
+                        ++pp->pp_defines->len;
+                    }
+                }
+                // Remove #define directive.
+                while (tok != tok2 + 1) {
+                    tok->kind = PpTokenKind_whitespace;
+                    tok->raw.len = 0;
+                    tok->raw.data = NULL;
+                    ++tok;
+                }
+            } else if (tok2->kind == PpTokenKind_identifier && string_equals_cstr(&tok2->raw, "include")) {
+                ++tok2;
+                while (tok2->kind != PpTokenKind_eof && tok2->kind == PpTokenKind_whitespace)
+                    ++tok2;
+                if (tok2->kind == PpTokenKind_string_literal) {
+                    // Process #include directive.
+                    PpToken* include_name = tok2;
+                    ++tok2;
+                    char* include_name_buf = calloc(include_name->raw.len - 2 + 1, sizeof(char));
+                    sprintf(include_name_buf, "%.*s", include_name->raw.len - 2, include_name->raw.data + 1);
+
+                    // Remove #include directive itself.
+                    while (tok != tok2 + 1) {
+                        tok->kind = PpTokenKind_whitespace;
+                        tok->raw.len = 0;
+                        tok->raw.data = NULL;
+                        ++tok;
+                    }
+
+                    // Read and preprocess included file.
+                    FILE* include_file = fopen(include_name_buf, "rb");
+                    if (include_file == NULL) {
+                        char* buf = calloc(1024, sizeof(char));
+                        sprintf(buf, "cannot open include file: %s", include_name_buf);
+                        fatal_error(buf);
+                    }
+                    char* include_source = read_all(include_file);
+                    fclose(include_file);
+
+                    PpToken* include_pp_tokens = do_preprocess(include_source, pp->include_depth + 1, pp->pp_defines);
+
+                    // Insert preprocessed tokens into the current token stream.
+                    int n_include_pp_tokens = 0;
+                    while (include_pp_tokens[n_include_pp_tokens].kind != PpTokenKind_eof) {
+                        ++n_include_pp_tokens;
+                    }
+
+                    // Shift existing tokens to make room for include tokens
+                    int n_pp_tokens_after_include = pp->n_pp_tokens - (tok - pp->pp_tokens);
+
+                    memmove(tok + n_include_pp_tokens, tok, n_pp_tokens_after_include * sizeof(PpToken));
+
+                    // Copy include tokens into the current position
+                    memcpy(tok, include_pp_tokens, n_include_pp_tokens * sizeof(PpToken));
+
+                    pp->n_pp_tokens += n_include_pp_tokens;
+                }
+            }
+        } else if (tok->kind == PpTokenKind_identifier) {
+            int pp_define_idx = find_pp_define(pp, &tok->raw);
+            if (pp_define_idx != -1) {
+                define_dest = pp->pp_defines->data[pp_define_idx].tokens;
+                tok->kind = define_dest->kind;
+                tok->raw.data = define_dest->raw.data;
+                tok->raw.len = define_dest->raw.len;
+            }
+        }
+        ++tok;
+    }
+}
+
+PpToken* do_preprocess(char* src, int depth, PpDefines* pp_defines) {
+    Preprocessor* pp = preprocessor_new(src, depth, pp_defines);
+    pp_tokenize_all(pp);
+    process_pp_directives(pp);
+    return pp->pp_tokens;
+}
+
+PpToken* preprocess(char* src) {
+    return do_preprocess(src, 0, pp_defines_new());
+}
diff --git a/std.h b/std.h
new file mode 100644
index 0000000..23a2e9a
--- /dev/null
+++ b/std.h
@@ -0,0 +1,31 @@
+typedef long size_t;
+
+struct FILE;
+typedef struct FILE FILE;
+
+extern FILE* stdin;
+extern FILE* stdout;
+extern FILE* stderr;
+
+int atoi(const char*);
+void* calloc(size_t, size_t);
+void exit(int);
+int fclose(FILE*);
+int fprintf(FILE*, const char*, ...);
+char* fgets(char*, int, FILE*);
+FILE* fopen(const char*, const char*);
+int getchar(void);
+int isalnum(int);
+int isalpha(int);
+int isdigit(int);
+int isspace(int);
+void* memcpy(void*, void*, size_t);
+void* memmove(void*, void*, size_t);
+int printf(const char*, ...);
+int sprintf(char*, const char*, ...);
+int strcmp(const char*, const char*);
+size_t strlen(const char*);
+int strncmp(const char*, const char*, size_t);
+char* strstr(const char*, const char*);
+
+#define NULL 0
diff --git a/tests/060.sh b/tests/060.sh
new file mode 100644
index 0000000..03d65b7
--- /dev/null
+++ b/tests/060.sh
@@ -0,0 +1,20 @@
+set -e
+
+cat <<'EOF' > expected
+42
+EOF
+
+cat <<'EOF' > header.h
+#define A 42
+EOF
+
+bash ../../test_diff.sh <<'EOF'
+#include "header.h"
+
+int printf();
+
+int main() {
+    printf("%d\n", A);
+    return 0;
+}
+EOF
diff --git a/tokenize.c b/tokenize.c
new file mode 100644
index 0000000..71427d0
--- /dev/null
+++ b/tokenize.c
@@ -0,0 +1,368 @@
+enum TokenKind {
+    TokenKind_eof,
+
+    TokenKind_and,
+    TokenKind_andand,
+    TokenKind_arrow,
+    TokenKind_assign,
+    TokenKind_assign_add,
+    TokenKind_assign_sub,
+    TokenKind_brace_l,
+    TokenKind_brace_r,
+    TokenKind_bracket_l,
+    TokenKind_bracket_r,
+    TokenKind_comma,
+    TokenKind_dot,
+    TokenKind_ellipsis,
+    TokenKind_eq,
+    TokenKind_ge,
+    TokenKind_gt,
+    TokenKind_ident,
+    TokenKind_keyword_break,
+    TokenKind_keyword_char,
+    TokenKind_keyword_const,
+    TokenKind_keyword_continue,
+    TokenKind_keyword_do,
+    TokenKind_keyword_else,
+    TokenKind_keyword_enum,
+    TokenKind_keyword_extern,
+    TokenKind_keyword_for,
+    TokenKind_keyword_if,
+    TokenKind_keyword_int,
+    TokenKind_keyword_long,
+    TokenKind_keyword_return,
+    TokenKind_keyword_sizeof,
+    TokenKind_keyword_struct,
+    TokenKind_keyword_typeof,
+    TokenKind_keyword_void,
+    TokenKind_keyword_while,
+    TokenKind_le,
+    TokenKind_lt,
+    TokenKind_literal_int,
+    TokenKind_literal_str,
+    TokenKind_minus,
+    TokenKind_minusminus,
+    TokenKind_ne,
+    TokenKind_not,
+    TokenKind_oror,
+    TokenKind_paren_l,
+    TokenKind_paren_r,
+    TokenKind_percent,
+    TokenKind_plus,
+    TokenKind_plusplus,
+    TokenKind_semicolon,
+    TokenKind_slash,
+    TokenKind_star,
+};
+typedef enum TokenKind TokenKind;
+
+struct Token {
+    TokenKind kind;
+    String raw;
+};
+typedef struct Token Token;
+
+const char* token_kind_stringify(TokenKind k) {
+    if (k == TokenKind_eof)
+        return "<eof>";
+    else if (k == TokenKind_and)
+        return "&";
+    else if (k == TokenKind_andand)
+        return "&&";
+    else if (k == TokenKind_arrow)
+        return "->";
+    else if (k == TokenKind_assign)
+        return "=";
+    else if (k == TokenKind_assign_add)
+        return "+=";
+    else if (k == TokenKind_assign_sub)
+        return "-=";
+    else if (k == TokenKind_brace_l)
+        return "{";
+    else if (k == TokenKind_brace_r)
+        return "}";
+    else if (k == TokenKind_bracket_l)
+        return "[";
+    else if (k == TokenKind_bracket_r)
+        return "]";
+    else if (k == TokenKind_comma)
+        return ",";
+    else if (k == TokenKind_dot)
+        return ".";
+    else if (k == TokenKind_ellipsis)
+        return "...";
+    else if (k == TokenKind_eq)
+        return "==";
+    else if (k == TokenKind_ge)
+        return ">=";
+    else if (k == TokenKind_gt)
+        return ">";
+    else if (k == TokenKind_ident)
+        return "<identifier>";
+    else if (k == TokenKind_keyword_break)
+        return "break";
+    else if (k == TokenKind_keyword_char)
+        return "char";
+    else if (k == TokenKind_keyword_const)
+        return "const";
+    else if (k == TokenKind_keyword_continue)
+        return "continue";
+    else if (k == TokenKind_keyword_do)
+        return "do";
+    else if (k == TokenKind_keyword_else)
+        return "else";
+    else if (k == TokenKind_keyword_enum)
+        return "enum";
+    else if (k == TokenKind_keyword_extern)
+        return "extern";
+    else if (k == TokenKind_keyword_for)
+        return "for";
+    else if (k == TokenKind_keyword_if)
+        return "if";
+    else if (k == TokenKind_keyword_int)
+        return "int";
+    else if (k == TokenKind_keyword_long)
+        return "long";
+    else if (k == TokenKind_keyword_return)
+        return "return";
+    else if (k == TokenKind_keyword_sizeof)
+        return "sizeof";
+    else if (k == TokenKind_keyword_struct)
+        return "struct";
+    else if (k == TokenKind_keyword_typeof)
+        return "typeof";
+    else if (k == TokenKind_keyword_void)
+        return "void";
+    else if (k == TokenKind_keyword_while)
+        return "while";
+    else if (k == TokenKind_le)
+        return "le";
+    else if (k == TokenKind_lt)
+        return "lt";
+    else if (k == TokenKind_literal_int)
+        return "<integer>";
+    else if (k == TokenKind_literal_str)
+        return "<string>";
+    else if (k == TokenKind_minus)
+        return "-";
+    else if (k == TokenKind_minusminus)
+        return "--";
+    else if (k == TokenKind_ne)
+        return "!=";
+    else if (k == TokenKind_not)
+        return "!";
+    else if (k == TokenKind_oror)
+        return "||";
+    else if (k == TokenKind_paren_l)
+        return "(";
+    else if (k == TokenKind_paren_r)
+        return ")";
+    else if (k == TokenKind_percent)
+        return "%";
+    else if (k == TokenKind_plus)
+        return "+";
+    else if (k == TokenKind_plusplus)
+        return "++";
+    else if (k == TokenKind_semicolon)
+        return ";";
+    else if (k == TokenKind_slash)
+        return "/";
+    else if (k == TokenKind_star)
+        return "*";
+    else
+        unreachable();
+}
+
+const char* token_stringify(Token* t) {
+    TokenKind k = t->kind;
+    if (k == TokenKind_ident || k == TokenKind_literal_int || k == TokenKind_literal_str) {
+        char* buf = calloc(t->raw.len + 1, sizeof(char));
+        sprintf(buf, "%.*s (%s)", t->raw.len, t->raw.data, token_kind_stringify(k));
+        return buf;
+    } else {
+        return token_kind_stringify(k);
+    }
+}
+
+struct Lexer {
+    PpToken* src;
+    int pos;
+    Token* tokens;
+    int n_tokens;
+};
+typedef struct Lexer Lexer;
+
+Lexer* lexer_new(PpToken* pp_tokens) {
+    Lexer* l = calloc(1, sizeof(Lexer));
+    l->src = pp_tokens;
+    l->tokens = calloc(1024 * 1024, sizeof(Token));
+    return l;
+}
+
+void tokenize_all(Lexer* l) {
+    char* buf;
+    int ch;
+    int start;
+    while (l->src[l->pos].kind != PpTokenKind_eof) {
+        PpToken* pp_tok = l->src + l->pos;
+        Token* tok = l->tokens + l->n_tokens;
+        PpTokenKind k = pp_tok->kind;
+        ++l->pos;
+        if (k == PpTokenKind_header_name) {
+            fatal_error("not implemented yet");
+        } else if (k == PpTokenKind_identifier) {
+            if (string_equals_cstr(&pp_tok->raw, "break")) {
+                tok->kind = TokenKind_keyword_break;
+            } else if (string_equals_cstr(&pp_tok->raw, "char")) {
+                tok->kind = TokenKind_keyword_char;
+            } else if (string_equals_cstr(&pp_tok->raw, "const")) {
+                tok->kind = TokenKind_keyword_const;
+            } else if (string_equals_cstr(&pp_tok->raw, "continue")) {
+                tok->kind = TokenKind_keyword_continue;
+            } else if (string_equals_cstr(&pp_tok->raw, "do")) {
+                tok->kind = TokenKind_keyword_do;
+            } else if (string_equals_cstr(&pp_tok->raw, "else")) {
+                tok->kind = TokenKind_keyword_else;
+            } else if (string_equals_cstr(&pp_tok->raw, "enum")) {
+                tok->kind = TokenKind_keyword_enum;
+            } else if (string_equals_cstr(&pp_tok->raw, "extern")) {
+                tok->kind = TokenKind_keyword_extern;
+            } else if (string_equals_cstr(&pp_tok->raw, "for")) {
+                tok->kind = TokenKind_keyword_for;
+            } else if (string_equals_cstr(&pp_tok->raw, "if")) {
+                tok->kind = TokenKind_keyword_if;
+            } else if (string_equals_cstr(&pp_tok->raw, "int")) {
+                tok->kind = TokenKind_keyword_int;
+            } else if (string_equals_cstr(&pp_tok->raw, "long")) {
+                tok->kind = TokenKind_keyword_long;
+            } else if (string_equals_cstr(&pp_tok->raw, "return")) {
+                tok->kind = TokenKind_keyword_return;
+            } else if (string_equals_cstr(&pp_tok->raw, "sizeof")) {
+                tok->kind = TokenKind_keyword_sizeof;
+            } else if (string_equals_cstr(&pp_tok->raw, "struct")) {
+                tok->kind = TokenKind_keyword_struct;
+            } else if (string_equals_cstr(&pp_tok->raw, "typedef")) {
+                tok->kind = TokenKind_keyword_typeof;
+            } else if (string_equals_cstr(&pp_tok->raw, "void")) {
+                tok->kind = TokenKind_keyword_void;
+            } else if (string_equals_cstr(&pp_tok->raw, "while")) {
+                tok->kind = TokenKind_keyword_while;
+            } else {
+                tok->kind = TokenKind_ident;
+            }
+            tok->raw.data = pp_tok->raw.data;
+            tok->raw.len = pp_tok->raw.len;
+        } else if (k == PpTokenKind_pp_number) {
+            tok->kind = TokenKind_literal_int;
+            tok->raw.data = pp_tok->raw.data;
+            tok->raw.len = pp_tok->raw.len;
+        } else if (k == PpTokenKind_character_constant) {
+            tok->kind = TokenKind_literal_int;
+            ch = pp_tok->raw.data[1];
+            if (ch == '\\') {
+                ch = pp_tok->raw.data[2];
+                if (ch == 'a') {
+                    ch = '\a';
+                } else if (ch == 'b') {
+                    ch = '\b';
+                } else if (ch == 'f') {
+                    ch = '\f';
+                } else if (ch == 'n') {
+                    ch = '\n';
+                } else if (ch == 'r') {
+                    ch = '\r';
+                } else if (ch == 't') {
+                    ch = '\t';
+                } else if (ch == 'v') {
+                    ch = '\v';
+                }
+            }
+            buf = calloc(4, sizeof(char));
+            sprintf(buf, "%d", ch);
+            tok->raw.data = buf;
+            tok->raw.len = strlen(buf);
+        } else if (k == PpTokenKind_string_literal) {
+            tok->kind = TokenKind_literal_str;
+            tok->raw.data = pp_tok->raw.data + 1;
+            tok->raw.len = pp_tok->raw.len - 2;
+        } else if (k == PpTokenKind_punctuator || k == PpTokenKind_other) {
+            if (string_equals_cstr(&pp_tok->raw, "(")) {
+                tok->kind = TokenKind_paren_l;
+            } else if (string_equals_cstr(&pp_tok->raw, ")")) {
+                tok->kind = TokenKind_paren_r;
+            } else if (string_equals_cstr(&pp_tok->raw, "{")) {
+                tok->kind = TokenKind_brace_l;
+            } else if (string_equals_cstr(&pp_tok->raw, "}")) {
+                tok->kind = TokenKind_brace_r;
+            } else if (string_equals_cstr(&pp_tok->raw, "[")) {
+                tok->kind = TokenKind_bracket_l;
+            } else if (string_equals_cstr(&pp_tok->raw, "]")) {
+                tok->kind = TokenKind_bracket_r;
+            } else if (string_equals_cstr(&pp_tok->raw, ",")) {
+                tok->kind = TokenKind_comma;
+            } else if (string_equals_cstr(&pp_tok->raw, ";")) {
+                tok->kind = TokenKind_semicolon;
+            } else if (string_equals_cstr(&pp_tok->raw, "+=")) {
+                tok->kind = TokenKind_assign_add;
+            } else if (string_equals_cstr(&pp_tok->raw, "++")) {
+                tok->kind = TokenKind_plusplus;
+            } else if (string_equals_cstr(&pp_tok->raw, "+")) {
+                tok->kind = TokenKind_plus;
+            } else if (string_equals_cstr(&pp_tok->raw, "||")) {
+                tok->kind = TokenKind_oror;
+            } else if (string_equals_cstr(&pp_tok->raw, "&&")) {
+                tok->kind = TokenKind_andand;
+            } else if (string_equals_cstr(&pp_tok->raw, "&")) {
+                tok->kind = TokenKind_and;
+            } else if (string_equals_cstr(&pp_tok->raw, "->")) {
+                tok->kind = TokenKind_arrow;
+            } else if (string_equals_cstr(&pp_tok->raw, "-=")) {
+                tok->kind = TokenKind_assign_sub;
+            } else if (string_equals_cstr(&pp_tok->raw, "--")) {
+                tok->kind = TokenKind_minusminus;
+            } else if (string_equals_cstr(&pp_tok->raw, "-")) {
+                tok->kind = TokenKind_minus;
+            } else if (string_equals_cstr(&pp_tok->raw, "*")) {
+                tok->kind = TokenKind_star;
+            } else if (string_equals_cstr(&pp_tok->raw, "/")) {
+                tok->kind = TokenKind_slash;
+            } else if (string_equals_cstr(&pp_tok->raw, "%")) {
+                tok->kind = TokenKind_percent;
+            } else if (string_equals_cstr(&pp_tok->raw, "...")) {
+                tok->kind = TokenKind_ellipsis;
+            } else if (string_equals_cstr(&pp_tok->raw, ".")) {
+                tok->kind = TokenKind_dot;
+            } else if (string_equals_cstr(&pp_tok->raw, "!=")) {
+                tok->kind = TokenKind_ne;
+            } else if (string_equals_cstr(&pp_tok->raw, "!")) {
+                tok->kind = TokenKind_not;
+            } else if (string_equals_cstr(&pp_tok->raw, "==")) {
+                tok->kind = TokenKind_eq;
+            } else if (string_equals_cstr(&pp_tok->raw, "=")) {
+                tok->kind = TokenKind_assign;
+            } else if (string_equals_cstr(&pp_tok->raw, "<=")) {
+                tok->kind = TokenKind_le;
+            } else if (string_equals_cstr(&pp_tok->raw, "<")) {
+                tok->kind = TokenKind_lt;
+            } else if (string_equals_cstr(&pp_tok->raw, ">=")) {
+                tok->kind = TokenKind_ge;
+            } else if (string_equals_cstr(&pp_tok->raw, ">")) {
+                tok->kind = TokenKind_gt;
+            } else {
+                sprintf(buf, "unknown token: %.*s", pp_tok->raw.len, pp_tok->raw.data);
+                fatal_error(buf);
+            }
+            tok->raw.data = pp_tok->raw.data;
+            tok->raw.len = pp_tok->raw.len;
+        } else if (k == PpTokenKind_whitespace) {
+            continue;
+        }
+        ++l->n_tokens;
+    }
+}
+
+Token* tokenize(PpToken* pp_tokens) {
+    Lexer* l = lexer_new(pp_tokens);
+    tokenize_all(l);
+    return l->tokens;
+}