reorganize compiler crates

ast/asdl_rs.py

@@ -0,0 +1,726 @@
+#! /usr/bin/env python
+"""Generate Rust code from an ASDL description."""
+
+import sys
+import json
+import textwrap
+
+from argparse import ArgumentParser
+from pathlib import Path
+
+import asdl
+
+TABSIZE = 4
+AUTOGEN_MESSAGE = "// File automatically generated by {}.\n"
+
+builtin_type_mapping = {
+    "identifier": "Ident",
+    "string": "String",
+    "int": "usize",
+    "constant": "Constant",
+}
+assert builtin_type_mapping.keys() == asdl.builtin_types
+
+
+def get_rust_type(name):
+    """Return a string for the C name of the type.
+
+    This function special cases the default types provided by asdl.
+    """
+    if name in asdl.builtin_types:
+        return builtin_type_mapping[name]
+    elif name.islower():
+        return "".join(part.capitalize() for part in name.split("_"))
+    else:
+        return name
+
+
+def is_simple(sum):
+    """Return True if a sum is a simple.
+
+    A sum is simple if its types have no fields, e.g.
+    unaryop = Invert | Not | UAdd | USub
+    """
+    for t in sum.types:
+        if t.fields:
+            return False
+    return True
+
+
+def asdl_of(name, obj):
+    if isinstance(obj, asdl.Product) or isinstance(obj, asdl.Constructor):
+        fields = ", ".join(map(str, obj.fields))
+        if fields:
+            fields = "({})".format(fields)
+        return "{}{}".format(name, fields)
+    else:
+        if is_simple(obj):
+            types = " | ".join(type.name for type in obj.types)
+        else:
+            sep = "\n{}| ".format(" " * (len(name) + 1))
+            types = sep.join(asdl_of(type.name, type) for type in obj.types)
+        return "{} = {}".format(name, types)
+
+
+class EmitVisitor(asdl.VisitorBase):
+    """Visit that emits lines"""
+
+    def __init__(self, file):
+        self.file = file
+        self.identifiers = set()
+        super(EmitVisitor, self).__init__()
+
+    def emit_identifier(self, name):
+        name = str(name)
+        if name in self.identifiers:
+            return
+        self.emit("_Py_IDENTIFIER(%s);" % name, 0)
+        self.identifiers.add(name)
+
+    def emit(self, line, depth):
+        if line:
+            line = (" " * TABSIZE * depth) + line
+        self.file.write(line + "\n")
+
+
+class TypeInfo:
+    def __init__(self, name):
+        self.name = name
+        self.has_userdata = None
+        self.children = set()
+        self.boxed = False
+
+    def __repr__(self):
+        return f"<TypeInfo: {self.name}>"
+
+    def determine_userdata(self, typeinfo, stack):
+        if self.name in stack:
+            return None
+        stack.add(self.name)
+        for child, child_seq in self.children:
+            if child in asdl.builtin_types:
+                continue
+            childinfo = typeinfo[child]
+            child_has_userdata = childinfo.determine_userdata(typeinfo, stack)
+            if self.has_userdata is None and child_has_userdata is True:
+                self.has_userdata = True
+
+        stack.remove(self.name)
+        return self.has_userdata
+
+
+class FindUserdataTypesVisitor(asdl.VisitorBase):
+    def __init__(self, typeinfo):
+        self.typeinfo = typeinfo
+        super().__init__()
+
+    def visitModule(self, mod):
+        for dfn in mod.dfns:
+            self.visit(dfn)
+        stack = set()
+        for info in self.typeinfo.values():
+            info.determine_userdata(self.typeinfo, stack)
+
+    def visitType(self, type):
+        self.typeinfo[type.name] = TypeInfo(type.name)
+        self.visit(type.value, type.name)
+
+    def visitSum(self, sum, name):
+        info = self.typeinfo[name]
+        if is_simple(sum):
+            info.has_userdata = False
+        else:
+            if len(sum.types) > 1:
+                info.boxed = True
+            if sum.attributes:
+                # attributes means Located, which has the `custom: U` field
+                info.has_userdata = True
+        for variant in sum.types:
+            self.add_children(name, variant.fields)
+
+    def visitProduct(self, product, name):
+        info = self.typeinfo[name]
+        if product.attributes:
+            # attributes means Located, which has the `custom: U` field
+            info.has_userdata = True
+        if len(product.fields) > 2:
+            info.boxed = True
+        self.add_children(name, product.fields)
+
+    def add_children(self, name, fields):
+        self.typeinfo[name].children.update((field.type, field.seq) for field in fields)
+
+
+def rust_field(field_name):
+    if field_name == "type":
+        return "type_"
+    else:
+        return field_name
+
+
+class TypeInfoEmitVisitor(EmitVisitor):
+    def __init__(self, file, typeinfo):
+        self.typeinfo = typeinfo
+        super().__init__(file)
+
+    def has_userdata(self, typ):
+        return self.typeinfo[typ].has_userdata
+
+    def get_generics(self, typ, *generics):
+        if self.has_userdata(typ):
+            return [f"<{g}>" for g in generics]
+        else:
+            return ["" for g in generics]
+
+
+class StructVisitor(TypeInfoEmitVisitor):
+    """Visitor to generate typedefs for AST."""
+
+    def visitModule(self, mod):
+        for dfn in mod.dfns:
+            self.visit(dfn)
+
+    def visitType(self, type, depth=0):
+        self.visit(type.value, type.name, depth)
+
+    def visitSum(self, sum, name, depth):
+        if is_simple(sum):
+            self.simple_sum(sum, name, depth)
+        else:
+            self.sum_with_constructors(sum, name, depth)
+
+    def emit_attrs(self, depth):
+        self.emit("#[derive(Debug, PartialEq)]", depth)
+
+    def simple_sum(self, sum, name, depth):
+        rustname = get_rust_type(name)
+        self.emit_attrs(depth)
+        self.emit(f"pub enum {rustname} {{", depth)
+        for variant in sum.types:
+            self.emit(f"{variant.name},", depth + 1)
+        self.emit("}", depth)
+        self.emit("", depth)
+
+    def sum_with_constructors(self, sum, name, depth):
+        typeinfo = self.typeinfo[name]
+        generics, generics_applied = self.get_generics(name, "U = ()", "U")
+        enumname = rustname = get_rust_type(name)
+        # all the attributes right now are for location, so if it has attrs we
+        # can just wrap it in Located<>
+        if sum.attributes:
+            enumname = rustname + "Kind"
+        self.emit_attrs(depth)
+        self.emit(f"pub enum {enumname}{generics} {{", depth)
+        for t in sum.types:
+            self.visit(t, typeinfo, depth + 1)
+        self.emit("}", depth)
+        if sum.attributes:
+            self.emit(
+                f"pub type {rustname}<U = ()> = Located<{enumname}{generics_applied}, U>;",
+                depth,
+            )
+        self.emit("", depth)
+
+    def visitConstructor(self, cons, parent, depth):
+        if cons.fields:
+            self.emit(f"{cons.name} {{", depth)
+            for f in cons.fields:
+                self.visit(f, parent, "", depth + 1)
+            self.emit("},", depth)
+        else:
+            self.emit(f"{cons.name},", depth)
+
+    def visitField(self, field, parent, vis, depth):
+        typ = get_rust_type(field.type)
+        fieldtype = self.typeinfo.get(field.type)
+        if fieldtype and fieldtype.has_userdata:
+            typ = f"{typ}<U>"
+        # don't box if we're doing Vec<T>, but do box if we're doing Vec<Option<Box<T>>>
+        if fieldtype and fieldtype.boxed and (not field.seq or field.opt):
+            typ = f"Box<{typ}>"
+        if field.opt:
+            typ = f"Option<{typ}>"
+        if field.seq:
+            typ = f"Vec<{typ}>"
+        name = rust_field(field.name)
+        self.emit(f"{vis}{name}: {typ},", depth)
+
+    def visitProduct(self, product, name, depth):
+        typeinfo = self.typeinfo[name]
+        generics, generics_applied = self.get_generics(name, "U = ()", "U")
+        dataname = rustname = get_rust_type(name)
+        if product.attributes:
+            dataname = rustname + "Data"
+        self.emit_attrs(depth)
+        has_expr = any(f.type != "identifier" for f in product.fields)
+        if has_expr:
+            datadef = f"{dataname}{generics}"
+        else:
+            datadef = dataname
+        self.emit(f"pub struct {datadef} {{", depth)
+        for f in product.fields:
+            self.visit(f, typeinfo, "pub ", depth + 1)
+        self.emit("}", depth)
+        if product.attributes:
+            # attributes should just be location info
+            if not has_expr:
+                generics_applied = ""
+            self.emit(
+                f"pub type {rustname}<U = ()> = Located<{dataname}{generics_applied}, U>;",
+                depth,
+            )
+        self.emit("", depth)
+
+
+class FoldTraitDefVisitor(TypeInfoEmitVisitor):
+    def visitModule(self, mod, depth):
+        self.emit("pub trait Fold<U> {", depth)
+        self.emit("type TargetU;", depth + 1)
+        self.emit("type Error;", depth + 1)
+        self.emit(
+            "fn map_user(&mut self, user: U) -> Result<Self::TargetU, Self::Error>;",
+            depth + 2,
+        )
+        for dfn in mod.dfns:
+            self.visit(dfn, depth + 2)
+        self.emit("}", depth)
+
+    def visitType(self, type, depth):
+        name = type.name
+        apply_u, apply_target_u = self.get_generics(name, "U", "Self::TargetU")
+        enumname = get_rust_type(name)
+        self.emit(
+            f"fn fold_{name}(&mut self, node: {enumname}{apply_u}) -> Result<{enumname}{apply_target_u}, Self::Error> {{",
+            depth,
+        )
+        self.emit(f"fold_{name}(self, node)", depth + 1)
+        self.emit("}", depth)
+
+
+class FoldImplVisitor(TypeInfoEmitVisitor):
+    def visitModule(self, mod, depth):
+        self.emit(
+            "fn fold_located<U, F: Fold<U> + ?Sized, T, MT>(folder: &mut F, node: Located<T, U>, f: impl FnOnce(&mut F, T) -> Result<MT, F::Error>) -> Result<Located<MT, F::TargetU>, F::Error> {",
+            depth,
+        )
+        self.emit(
+            "Ok(Located { custom: folder.map_user(node.custom)?, location: node.location, node: f(folder, node.node)? })",
+            depth + 1,
+        )
+        self.emit("}", depth)
+        for dfn in mod.dfns:
+            self.visit(dfn, depth)
+
+    def visitType(self, type, depth=0):
+        self.visit(type.value, type.name, depth)
+
+    def visitSum(self, sum, name, depth):
+        apply_t, apply_u, apply_target_u = self.get_generics(
+            name, "T", "U", "F::TargetU"
+        )
+        enumname = get_rust_type(name)
+        is_located = bool(sum.attributes)
+
+        self.emit(f"impl<T, U> Foldable<T, U> for {enumname}{apply_t} {{", depth)
+        self.emit(f"type Mapped = {enumname}{apply_u};", depth + 1)
+        self.emit(
+            "fn fold<F: Fold<T, TargetU = U> + ?Sized>(self, folder: &mut F) -> Result<Self::Mapped, F::Error> {",
+            depth + 1,
+        )
+        self.emit(f"folder.fold_{name}(self)", depth + 2)
+        self.emit("}", depth + 1)
+        self.emit("}", depth)
+
+        self.emit(
+            f"pub fn fold_{name}<U, F: Fold<U> + ?Sized>(#[allow(unused)] folder: &mut F, node: {enumname}{apply_u}) -> Result<{enumname}{apply_target_u}, F::Error> {{",
+            depth,
+        )
+        if is_located:
+            self.emit("fold_located(folder, node, |folder, node| {", depth)
+            enumname += "Kind"
+        self.emit("match node {", depth + 1)
+        for cons in sum.types:
+            fields_pattern = self.make_pattern(cons.fields)
+            self.emit(
+                f"{enumname}::{cons.name} {{ {fields_pattern} }} => {{", depth + 2
+            )
+            self.gen_construction(f"{enumname}::{cons.name}", cons.fields, depth + 3)
+            self.emit("}", depth + 2)
+        self.emit("}", depth + 1)
+        if is_located:
+            self.emit("})", depth)
+        self.emit("}", depth)
+
+    def visitProduct(self, product, name, depth):
+        apply_t, apply_u, apply_target_u = self.get_generics(
+            name, "T", "U", "F::TargetU"
+        )
+        structname = get_rust_type(name)
+        is_located = bool(product.attributes)
+
+        self.emit(f"impl<T, U> Foldable<T, U> for {structname}{apply_t} {{", depth)
+        self.emit(f"type Mapped = {structname}{apply_u};", depth + 1)
+        self.emit(
+            "fn fold<F: Fold<T, TargetU = U> + ?Sized>(self, folder: &mut F) -> Result<Self::Mapped, F::Error> {",
+            depth + 1,
+        )
+        self.emit(f"folder.fold_{name}(self)", depth + 2)
+        self.emit("}", depth + 1)
+        self.emit("}", depth)
+
+        self.emit(
+            f"pub fn fold_{name}<U, F: Fold<U> + ?Sized>(#[allow(unused)] folder: &mut F, node: {structname}{apply_u}) -> Result<{structname}{apply_target_u}, F::Error> {{",
+            depth,
+        )
+        if is_located:
+            self.emit("fold_located(folder, node, |folder, node| {", depth)
+            structname += "Data"
+        fields_pattern = self.make_pattern(product.fields)
+        self.emit(f"let {structname} {{ {fields_pattern} }} = node;", depth + 1)
+        self.gen_construction(structname, product.fields, depth + 1)
+        if is_located:
+            self.emit("})", depth)
+        self.emit("}", depth)
+
+    def make_pattern(self, fields):
+        return ",".join(rust_field(f.name) for f in fields)
+
+    def gen_construction(self, cons_path, fields, depth):
+        self.emit(f"Ok({cons_path} {{", depth)
+        for field in fields:
+            name = rust_field(field.name)
+            self.emit(f"{name}: Foldable::fold({name}, folder)?,", depth + 1)
+        self.emit("})", depth)
+
+
+class FoldModuleVisitor(TypeInfoEmitVisitor):
+    def visitModule(self, mod):
+        depth = 0
+        self.emit('#[cfg(feature = "fold")]', depth)
+        self.emit("pub mod fold {", depth)
+        self.emit("use super::*;", depth + 1)
+        self.emit("use crate::fold_helpers::Foldable;", depth + 1)
+        FoldTraitDefVisitor(self.file, self.typeinfo).visit(mod, depth + 1)
+        FoldImplVisitor(self.file, self.typeinfo).visit(mod, depth + 1)
+        self.emit("}", depth)
+
+
+class ClassDefVisitor(EmitVisitor):
+    def visitModule(self, mod):
+        for dfn in mod.dfns:
+            self.visit(dfn)
+
+    def visitType(self, type, depth=0):
+        self.visit(type.value, type.name, depth)
+
+    def visitSum(self, sum, name, depth):
+        structname = "NodeKind" + get_rust_type(name)
+        self.emit(
+            f'#[pyclass(module = "_ast", name = {json.dumps(name)}, base = "AstNode")]',
+            depth,
+        )
+        self.emit(f"struct {structname};", depth)
+        self.emit("#[pyclass(flags(HAS_DICT, BASETYPE))]", depth)
+        self.emit(f"impl {structname} {{}}", depth)
+        for cons in sum.types:
+            self.visit(cons, sum.attributes, structname, depth)
+
+    def visitConstructor(self, cons, attrs, base, depth):
+        self.gen_classdef(cons.name, cons.fields, attrs, depth, base)
+
+    def visitProduct(self, product, name, depth):
+        self.gen_classdef(name, product.fields, product.attributes, depth)
+
+    def gen_classdef(self, name, fields, attrs, depth, base="AstNode"):
+        structname = "Node" + get_rust_type(name)
+        self.emit(
+            f'#[pyclass(module = "_ast", name = {json.dumps(name)}, base = {json.dumps(base)})]',
+            depth,
+        )
+        self.emit(f"struct {structname};", depth)
+        self.emit("#[pyclass(flags(HAS_DICT, BASETYPE))]", depth)
+        self.emit(f"impl {structname} {{", depth)
+        self.emit(f"#[extend_class]", depth + 1)
+        self.emit(
+            "fn extend_class_with_fields(ctx: &Context, class: &'static Py<PyType>) {",
+            depth + 1,
+        )
+        fields = ",".join(
+            f"ctx.new_str(ascii!({json.dumps(f.name)})).into()" for f in fields
+        )
+        self.emit(
+            f"class.set_attr(identifier!(ctx, _fields), ctx.new_list(vec![{fields}]).into());",
+            depth + 2,
+        )
+        attrs = ",".join(
+            f"ctx.new_str(ascii!({json.dumps(attr.name)})).into()" for attr in attrs
+        )
+        self.emit(
+            f"class.set_attr(identifier!(ctx, _attributes), ctx.new_list(vec![{attrs}]).into());",
+            depth + 2,
+        )
+        self.emit("}", depth + 1)
+        self.emit("}", depth)
+
+
+class ExtendModuleVisitor(EmitVisitor):
+    def visitModule(self, mod):
+        depth = 0
+        self.emit(
+            "pub fn extend_module_nodes(vm: &VirtualMachine, module: &PyObject) {",
+            depth,
+        )
+        self.emit("extend_module!(vm, module, {", depth + 1)
+        for dfn in mod.dfns:
+            self.visit(dfn, depth + 2)
+        self.emit("})", depth + 1)
+        self.emit("}", depth)
+
+    def visitType(self, type, depth):
+        self.visit(type.value, type.name, depth)
+
+    def visitSum(self, sum, name, depth):
+        rust_name = get_rust_type(name)
+        self.emit(
+            f"{json.dumps(name)} => NodeKind{rust_name}::make_class(&vm.ctx),", depth
+        )
+        for cons in sum.types:
+            self.visit(cons, depth)
+
+    def visitConstructor(self, cons, depth):
+        self.gen_extension(cons.name, depth)
+
+    def visitProduct(self, product, name, depth):
+        self.gen_extension(name, depth)
+
+    def gen_extension(self, name, depth):
+        rust_name = get_rust_type(name)
+        self.emit(f"{json.dumps(name)} => Node{rust_name}::make_class(&vm.ctx),", depth)
+
+
+class TraitImplVisitor(EmitVisitor):
+    def visitModule(self, mod):
+        for dfn in mod.dfns:
+            self.visit(dfn)
+
+    def visitType(self, type, depth=0):
+        self.visit(type.value, type.name, depth)
+
+    def visitSum(self, sum, name, depth):
+        enumname = get_rust_type(name)
+        if sum.attributes:
+            enumname += "Kind"
+
+        self.emit(f"impl NamedNode for ast::{enumname} {{", depth)
+        self.emit(f"const NAME: &'static str = {json.dumps(name)};", depth + 1)
+        self.emit("}", depth)
+        self.emit(f"impl Node for ast::{enumname} {{", depth)
+        self.emit(
+            "fn ast_to_object(self, _vm: &VirtualMachine) -> PyObjectRef {", depth + 1
+        )
+        self.emit("match self {", depth + 2)
+        for variant in sum.types:
+            self.constructor_to_object(variant, enumname, depth + 3)
+        self.emit("}", depth + 2)
+        self.emit("}", depth + 1)
+        self.emit(
+            "fn ast_from_object(_vm: &VirtualMachine, _object: PyObjectRef) -> PyResult<Self> {",
+            depth + 1,
+        )
+        self.gen_sum_fromobj(sum, name, enumname, depth + 2)
+        self.emit("}", depth + 1)
+        self.emit("}", depth)
+
+    def constructor_to_object(self, cons, enumname, depth):
+        fields_pattern = self.make_pattern(cons.fields)
+        self.emit(f"ast::{enumname}::{cons.name} {{ {fields_pattern} }} => {{", depth)
+        self.make_node(cons.name, cons.fields, depth + 1)
+        self.emit("}", depth)
+
+    def visitProduct(self, product, name, depth):
+        structname = get_rust_type(name)
+        if product.attributes:
+            structname += "Data"
+
+        self.emit(f"impl NamedNode for ast::{structname} {{", depth)
+        self.emit(f"const NAME: &'static str = {json.dumps(name)};", depth + 1)
+        self.emit("}", depth)
+        self.emit(f"impl Node for ast::{structname} {{", depth)
+        self.emit(
+            "fn ast_to_object(self, _vm: &VirtualMachine) -> PyObjectRef {", depth + 1
+        )
+        fields_pattern = self.make_pattern(product.fields)
+        self.emit(f"let ast::{structname} {{ {fields_pattern} }} = self;", depth + 2)
+        self.make_node(name, product.fields, depth + 2)
+        self.emit("}", depth + 1)
+        self.emit(
+            "fn ast_from_object(_vm: &VirtualMachine, _object: PyObjectRef) -> PyResult<Self> {",
+            depth + 1,
+        )
+        self.gen_product_fromobj(product, name, structname, depth + 2)
+        self.emit("}", depth + 1)
+        self.emit("}", depth)
+
+    def make_node(self, variant, fields, depth):
+        rust_variant = get_rust_type(variant)
+        self.emit(
+            f"let _node = AstNode.into_ref_with_type(_vm, Node{rust_variant}::static_type().to_owned()).unwrap();",
+            depth,
+        )
+        if fields:
+            self.emit("let _dict = _node.as_object().dict().unwrap();", depth)
+        for f in fields:
+            self.emit(
+                f"_dict.set_item({json.dumps(f.name)}, {rust_field(f.name)}.ast_to_object(_vm), _vm).unwrap();",
+                depth,
+            )
+        self.emit("_node.into()", depth)
+
+    def make_pattern(self, fields):
+        return ",".join(rust_field(f.name) for f in fields)
+
+    def gen_sum_fromobj(self, sum, sumname, enumname, depth):
+        if sum.attributes:
+            self.extract_location(sumname, depth)
+
+        self.emit("let _cls = _object.class();", depth)
+        self.emit("Ok(", depth)
+        for cons in sum.types:
+            self.emit(f"if _cls.is(Node{cons.name}::static_type()) {{", depth)
+            self.gen_construction(f"{enumname}::{cons.name}", cons, sumname, depth + 1)
+            self.emit("} else", depth)
+
+        self.emit("{", depth)
+        msg = f'format!("expected some sort of {sumname}, but got {{}}",_object.repr(_vm)?)'
+        self.emit(f"return Err(_vm.new_type_error({msg}));", depth + 1)
+        self.emit("})", depth)
+
+    def gen_product_fromobj(self, product, prodname, structname, depth):
+        if product.attributes:
+            self.extract_location(prodname, depth)
+
+        self.emit("Ok(", depth)
+        self.gen_construction(structname, product, prodname, depth + 1)
+        self.emit(")", depth)
+
+    def gen_construction(self, cons_path, cons, name, depth):
+        self.emit(f"ast::{cons_path} {{", depth)
+        for field in cons.fields:
+            self.emit(
+                f"{rust_field(field.name)}: {self.decode_field(field, name)},",
+                depth + 1,
+            )
+        self.emit("}", depth)
+
+    def extract_location(self, typename, depth):
+        row = self.decode_field(asdl.Field("int", "lineno"), typename)
+        column = self.decode_field(asdl.Field("int", "col_offset"), typename)
+        self.emit(f"let _location = ast::Location::new({row}, {column});", depth)
+
+    def wrap_located_node(self, depth):
+        self.emit(f"let node = ast::Located::new(_location, node);", depth)
+
+    def decode_field(self, field, typename):
+        name = json.dumps(field.name)
+        if field.opt and not field.seq:
+            return f"get_node_field_opt(_vm, &_object, {name})?.map(|obj| Node::ast_from_object(_vm, obj)).transpose()?"
+        else:
+            return f"Node::ast_from_object(_vm, get_node_field(_vm, &_object, {name}, {json.dumps(typename)})?)?"
+
+
+class ChainOfVisitors:
+    def __init__(self, *visitors):
+        self.visitors = visitors
+
+    def visit(self, object):
+        for v in self.visitors:
+            v.visit(object)
+            v.emit("", 0)
+
+
+def write_ast_def(mod, typeinfo, f):
+    f.write(
+        textwrap.dedent(
+            """
+        #![allow(clippy::derive_partial_eq_without_eq)]
+        
+        pub use crate::constant::*;
+        pub use crate::location::Location;
+
+        type Ident = String;
+        \n
+    """
+        )
+    )
+    StructVisitor(f, typeinfo).emit_attrs(0)
+    f.write(
+        textwrap.dedent(
+            """
+        pub struct Located<T, U = ()> {
+            pub location: Location,
+            pub custom: U,
+            pub node: T,
+        }
+    
+        impl<T> Located<T> {
+            pub fn new(location: Location, node: T) -> Self {
+                Self { location, custom: (), node }
+            }
+        }
+        \n
+    """.lstrip()
+        )
+    )
+
+    c = ChainOfVisitors(StructVisitor(f, typeinfo), FoldModuleVisitor(f, typeinfo))
+    c.visit(mod)
+
+
+def write_ast_mod(mod, f):
+    f.write(
+        textwrap.dedent(
+            """
+        #![allow(clippy::all)]
+
+        use super::*;
+        use crate::common::ascii;
+
+    """
+        )
+    )
+
+    c = ChainOfVisitors(ClassDefVisitor(f), TraitImplVisitor(f), ExtendModuleVisitor(f))
+    c.visit(mod)
+
+
+def main(input_filename, ast_mod_filename, ast_def_filename, dump_module=False):
+    auto_gen_msg = AUTOGEN_MESSAGE.format("/".join(Path(__file__).parts[-2:]))
+    mod = asdl.parse(input_filename)
+    if dump_module:
+        print("Parsed Module:")
+        print(mod)
+    if not asdl.check(mod):
+        sys.exit(1)
+
+    typeinfo = {}
+    FindUserdataTypesVisitor(typeinfo).visit(mod)
+
+    with ast_def_filename.open("w") as def_file, ast_mod_filename.open("w") as mod_file:
+        def_file.write(auto_gen_msg)
+        write_ast_def(mod, typeinfo, def_file)
+
+        mod_file.write(auto_gen_msg)
+        write_ast_mod(mod, mod_file)
+
+    print(f"{ast_def_filename}, {ast_mod_filename} regenerated.")
+
+
+if __name__ == "__main__":
+    parser = ArgumentParser()
+    parser.add_argument("input_file", type=Path)
+    parser.add_argument("-M", "--mod-file", type=Path, required=True)
+    parser.add_argument("-D", "--def-file", type=Path, required=True)
+    parser.add_argument("-d", "--dump-module", action="store_true")
+
+    args = parser.parse_args()
+    main(args.input_file, args.mod_file, args.def_file, args.dump_module)