from __future__ import annotations import re import sys import warnings from collections.abc import Sequence from typing import Any, Callable, Final, Literal, Optional, TypeVar, Union, cast, overload from mypy import defaults, errorcodes as codes, message_registry from mypy.errors import Errors from mypy.message_registry import ErrorMessage from mypy.nodes import ( ARG_NAMED, ARG_NAMED_OPT, ARG_OPT, ARG_POS, ARG_STAR, ARG_STAR2, MISSING_FALLBACK, PARAM_SPEC_KIND, TYPE_VAR_KIND, TYPE_VAR_TUPLE_KIND, ArgKind, Argument, AssertStmt, AssignmentExpr, AssignmentStmt, AwaitExpr, Block, BreakStmt, BytesExpr, CallExpr, ClassDef, ComparisonExpr, ComplexExpr, ConditionalExpr, ContinueStmt, Decorator, DelStmt, DictExpr, DictionaryComprehension, EllipsisExpr, Expression, ExpressionStmt, FloatExpr, ForStmt, FuncDef, GeneratorExpr, GlobalDecl, IfStmt, Import, ImportAll, ImportBase, ImportFrom, IndexExpr, IntExpr, LambdaExpr, ListComprehension, ListExpr, MatchStmt, MemberExpr, MypyFile, NameExpr, Node, NonlocalDecl, OperatorAssignmentStmt, OpExpr, OverloadedFuncDef, OverloadPart, PassStmt, RaiseStmt, RefExpr, ReturnStmt, SetComprehension, SetExpr, SliceExpr, StarExpr, Statement, StrExpr, SuperExpr, TempNode, TryStmt, TupleExpr, TypeAliasStmt, TypeParam, UnaryExpr, Var, WhileStmt, WithStmt, YieldExpr, YieldFromExpr, check_arg_names, ) from mypy.options import Options from mypy.patterns import ( AsPattern, ClassPattern, MappingPattern, OrPattern, SequencePattern, SingletonPattern, StarredPattern, ValuePattern, ) from mypy.reachability import infer_reachability_of_if_statement, mark_block_unreachable from mypy.sharedparse import argument_elide_name, special_function_elide_names from mypy.traverser import TraverserVisitor from mypy.types import ( AnyType, CallableArgument, CallableType, EllipsisType, Instance, ProperType, RawExpressionType, TupleType, Type, TypedDictType, TypeList, TypeOfAny, UnboundType, UnionType, UnpackType, ) from mypy.util import bytes_to_human_readable_repr, unnamed_function # pull this into a final variable to make mypyc be quiet about the # the default argument warning PY_MINOR_VERSION: Final = sys.version_info[1] import ast as ast3 # TODO: Index, ExtSlice are deprecated in 3.9. from ast import AST, Attribute, Call, FunctionType, Index, Name, Starred, UAdd, UnaryOp, USub def ast3_parse( source: str | bytes, filename: str, mode: str, feature_version: int = PY_MINOR_VERSION ) -> AST: return ast3.parse( source, filename, mode, type_comments=True, # This works the magic feature_version=feature_version, ) NamedExpr = ast3.NamedExpr Constant = ast3.Constant if sys.version_info >= (3, 10): Match = ast3.Match MatchValue = ast3.MatchValue MatchSingleton = ast3.MatchSingleton MatchSequence = ast3.MatchSequence MatchStar = ast3.MatchStar MatchMapping = ast3.MatchMapping MatchClass = ast3.MatchClass MatchAs = ast3.MatchAs MatchOr = ast3.MatchOr AstNode = Union[ast3.expr, ast3.stmt, ast3.pattern, ast3.ExceptHandler] else: Match = Any MatchValue = Any MatchSingleton = Any MatchSequence = Any MatchStar = Any MatchMapping = Any MatchClass = Any MatchAs = Any MatchOr = Any AstNode = Union[ast3.expr, ast3.stmt, ast3.ExceptHandler] if sys.version_info >= (3, 11): TryStar = ast3.TryStar else: TryStar = Any if sys.version_info >= (3, 12): ast_TypeAlias = ast3.TypeAlias ast_ParamSpec = ast3.ParamSpec ast_TypeVar = ast3.TypeVar ast_TypeVarTuple = ast3.TypeVarTuple else: ast_TypeAlias = Any ast_ParamSpec = Any ast_TypeVar = Any ast_TypeVarTuple = Any N = TypeVar("N", bound=Node) # There is no way to create reasonable fallbacks at this stage, # they must be patched later. _dummy_fallback: Final = Instance(MISSING_FALLBACK, [], -1) TYPE_IGNORE_PATTERN: Final = re.compile(r"[^#]*#\s*type:\s*ignore\s*(.*)") def parse( source: str | bytes, fnam: str, module: str | None, errors: Errors, options: Options | None = None, ) -> MypyFile: """Parse a source file, without doing any semantic analysis. Return the parse tree. If errors is not provided, raise ParseError on failure. Otherwise, use the errors object to report parse errors. """ ignore_errors = (options is not None and options.ignore_errors) or ( fnam in errors.ignored_files ) # If errors are ignored, we can drop many function bodies to speed up type checking. strip_function_bodies = ignore_errors and (options is None or not options.preserve_asts) if options is None: options = Options() errors.set_file(fnam, module, options=options) is_stub_file = fnam.endswith(".pyi") if is_stub_file: feature_version = defaults.PYTHON3_VERSION[1] if options.python_version[0] == 3 and options.python_version[1] > feature_version: feature_version = options.python_version[1] else: assert options.python_version[0] >= 3 feature_version = options.python_version[1] try: # Disable deprecation warnings about \u with warnings.catch_warnings(): warnings.filterwarnings("ignore", category=DeprecationWarning) ast = ast3_parse(source, fnam, "exec", feature_version=feature_version) tree = ASTConverter( options=options, is_stub=is_stub_file, errors=errors, strip_function_bodies=strip_function_bodies, path=fnam, ).visit(ast) except RecursionError as e: # For very complex expressions it is possible to hit recursion limit # before reaching a leaf node. # Should reject at top level instead at bottom, since bottom would already # be at the threshold of the recursion limit, and may fail again later. # E.G. x1+x2+x3+...+xn -> BinOp(left=BinOp(left=BinOp(left=... try: # But to prove that is the cause of this particular recursion error, # try to walk the tree using builtin visitor ast3.NodeVisitor().visit(ast) except RecursionError: errors.report( -1, -1, "Source expression too complex to parse", blocker=False, code=codes.MISC ) tree = MypyFile([], [], False, {}) else: # re-raise original recursion error if it *can* be unparsed, # maybe this is some other issue that shouldn't be silenced/misdirected raise e except SyntaxError as e: message = e.msg if feature_version > sys.version_info.minor and message.startswith("invalid syntax"): python_version_str = f"{options.python_version[0]}.{options.python_version[1]}" message += f"; you likely need to run mypy using Python {python_version_str} or newer" errors.report( e.lineno if e.lineno is not None else -1, e.offset, message, blocker=True, code=codes.SYNTAX, ) tree = MypyFile([], [], False, {}) assert isinstance(tree, MypyFile) return tree def parse_type_ignore_tag(tag: str | None) -> list[str] | None: """Parse optional "[code, ...]" tag after "# type: ignore". Return: * [] if no tag was found (ignore all errors) * list of ignored error codes if a tag was found * None if the tag was invalid. """ if not tag or tag.strip() == "" or tag.strip().startswith("#"): # No tag -- ignore all errors. return [] m = re.match(r"\s*\[([^]#]*)\]\s*(#.*)?$", tag) if m is None: # Invalid "# type: ignore" comment. return None return [code.strip() for code in m.group(1).split(",")] def parse_type_comment( type_comment: str, line: int, column: int, errors: Errors | None ) -> tuple[list[str] | None, ProperType | None]: """Parse type portion of a type comment (+ optional type ignore). Return (ignore info, parsed type). """ try: typ = ast3_parse(type_comment, "", "eval") except SyntaxError: if errors is not None: stripped_type = type_comment.split("#", 2)[0].strip() err_msg = message_registry.TYPE_COMMENT_SYNTAX_ERROR_VALUE.format(stripped_type) errors.report(line, column, err_msg.value, blocker=True, code=err_msg.code) return None, None else: raise else: extra_ignore = TYPE_IGNORE_PATTERN.match(type_comment) if extra_ignore: tag: str | None = extra_ignore.group(1) ignored: list[str] | None = parse_type_ignore_tag(tag) if ignored is None: if errors is not None: errors.report( line, column, message_registry.INVALID_TYPE_IGNORE.value, code=codes.SYNTAX ) else: raise SyntaxError else: ignored = None assert isinstance(typ, ast3.Expression) converted = TypeConverter( errors, line=line, override_column=column, is_evaluated=False ).visit(typ.body) return ignored, converted def parse_type_string( expr_string: str, expr_fallback_name: str, line: int, column: int ) -> ProperType: """Parses a type that was originally present inside of an explicit string. For example, suppose we have the type `Foo["blah"]`. We should parse the string expression "blah" using this function. """ try: _, node = parse_type_comment(f"({expr_string})", line=line, column=column, errors=None) if isinstance(node, (UnboundType, UnionType)) and node.original_str_expr is None: node.original_str_expr = expr_string node.original_str_fallback = expr_fallback_name return node else: return RawExpressionType(expr_string, expr_fallback_name, line, column) except (SyntaxError, ValueError): # Note: the parser will raise a `ValueError` instead of a SyntaxError if # the string happens to contain things like \x00. return RawExpressionType(expr_string, expr_fallback_name, line, column) def is_no_type_check_decorator(expr: ast3.expr) -> bool: if isinstance(expr, Name): return expr.id == "no_type_check" elif isinstance(expr, Attribute): if isinstance(expr.value, Name): return expr.value.id == "typing" and expr.attr == "no_type_check" return False def find_disallowed_expression_in_annotation_scope(expr: ast3.expr | None) -> ast3.expr | None: if expr is None: return None for node in ast3.walk(expr): if isinstance(node, (ast3.Yield, ast3.YieldFrom, ast3.NamedExpr, ast3.Await)): return node return None class ASTConverter: def __init__( self, options: Options, is_stub: bool, errors: Errors, *, strip_function_bodies: bool, path: str, ) -> None: # 'C' for class, 'D' for function signature, 'F' for function, 'L' for lambda self.class_and_function_stack: list[Literal["C", "D", "F", "L"]] = [] self.imports: list[ImportBase] = [] self.options = options self.is_stub = is_stub self.errors = errors self.strip_function_bodies = strip_function_bodies self.path = path self.type_ignores: dict[int, list[str]] = {} # Cache of visit_X methods keyed by type of visited object self.visitor_cache: dict[type, Callable[[AST | None], Any]] = {} def note(self, msg: str, line: int, column: int) -> None: self.errors.report(line, column, msg, severity="note", code=codes.SYNTAX) def fail(self, msg: ErrorMessage, line: int, column: int, blocker: bool) -> None: if blocker or not self.options.ignore_errors: # Make sure self.errors reflects any type ignores that we have parsed self.errors.set_file_ignored_lines( self.path, self.type_ignores, self.options.ignore_errors ) self.errors.report(line, column, msg.value, blocker=blocker, code=msg.code) def fail_merge_overload(self, node: IfStmt) -> None: self.fail( message_registry.FAILED_TO_MERGE_OVERLOADS, line=node.line, column=node.column, blocker=False, ) def visit(self, node: AST | None) -> Any: if node is None: return None typeobj = type(node) visitor = self.visitor_cache.get(typeobj) if visitor is None: method = "visit_" + node.__class__.__name__ visitor = getattr(self, method) self.visitor_cache[typeobj] = visitor return visitor(node) def set_line(self, node: N, n: AstNode) -> N: node.line = n.lineno node.column = n.col_offset node.end_line = getattr(n, "end_lineno", None) node.end_column = getattr(n, "end_col_offset", None) return node def translate_opt_expr_list(self, l: Sequence[AST | None]) -> list[Expression | None]: res: list[Expression | None] = [] for e in l: exp = self.visit(e) res.append(exp) return res def translate_expr_list(self, l: Sequence[AST]) -> list[Expression]: return cast(list[Expression], self.translate_opt_expr_list(l)) def get_lineno(self, node: ast3.expr | ast3.stmt) -> int: if ( isinstance(node, (ast3.AsyncFunctionDef, ast3.ClassDef, ast3.FunctionDef)) and node.decorator_list ): return node.decorator_list[0].lineno return node.lineno def translate_stmt_list( self, stmts: Sequence[ast3.stmt], *, ismodule: bool = False, can_strip: bool = False, is_coroutine: bool = False, ) -> list[Statement]: # A "# type: ignore" comment before the first statement of a module # ignores the whole module: if ( ismodule and stmts and self.type_ignores and min(self.type_ignores) < self.get_lineno(stmts[0]) ): ignores = self.type_ignores[min(self.type_ignores)] if ignores: joined_ignores = ", ".join(ignores) self.fail( message_registry.TYPE_IGNORE_WITH_ERRCODE_ON_MODULE.format(joined_ignores), line=min(self.type_ignores), column=0, blocker=False, ) self.errors.used_ignored_lines[self.errors.file][min(self.type_ignores)].append( codes.FILE.code ) block = Block(self.fix_function_overloads(self.translate_stmt_list(stmts))) self.set_block_lines(block, stmts) mark_block_unreachable(block) return [block] stack = self.class_and_function_stack # Fast case for stripping function bodies if ( can_strip and self.strip_function_bodies and len(stack) == 1 and stack[0] == "F" and not is_coroutine ): return [] res: list[Statement] = [] for stmt in stmts: node = self.visit(stmt) res.append(node) # Slow case for stripping function bodies if can_strip and self.strip_function_bodies: if stack[-2:] == ["C", "F"]: if is_possible_trivial_body(res): can_strip = False else: # We only strip method bodies if they don't assign to an attribute, as # this may define an attribute which has an externally visible effect. visitor = FindAttributeAssign() for s in res: s.accept(visitor) if visitor.found: can_strip = False break if can_strip and stack[-1] == "F" and is_coroutine: # Yields inside an async function affect the return type and should not # be stripped. yield_visitor = FindYield() for s in res: s.accept(yield_visitor) if yield_visitor.found: can_strip = False break if can_strip: return [] return res def translate_type_comment( self, n: ast3.stmt | ast3.arg, type_comment: str | None ) -> ProperType | None: if type_comment is None: return None else: lineno = n.lineno extra_ignore, typ = parse_type_comment(type_comment, lineno, n.col_offset, self.errors) if extra_ignore is not None: self.type_ignores[lineno] = extra_ignore return typ op_map: Final[dict[type[AST], str]] = { ast3.Add: "+", ast3.Sub: "-", ast3.Mult: "*", ast3.MatMult: "@", ast3.Div: "/", ast3.Mod: "%", ast3.Pow: "**", ast3.LShift: "<<", ast3.RShift: ">>", ast3.BitOr: "|", ast3.BitXor: "^", ast3.BitAnd: "&", ast3.FloorDiv: "//", } def from_operator(self, op: ast3.operator) -> str: op_name = ASTConverter.op_map.get(type(op)) if op_name is None: raise RuntimeError("Unknown operator " + str(type(op))) else: return op_name comp_op_map: Final[dict[type[AST], str]] = { ast3.Gt: ">", ast3.Lt: "<", ast3.Eq: "==", ast3.GtE: ">=", ast3.LtE: "<=", ast3.NotEq: "!=", ast3.Is: "is", ast3.IsNot: "is not", ast3.In: "in", ast3.NotIn: "not in", # codespell:ignore notin } def from_comp_operator(self, op: ast3.cmpop) -> str: op_name = ASTConverter.comp_op_map.get(type(op)) if op_name is None: raise RuntimeError("Unknown comparison operator " + str(type(op))) else: return op_name def set_block_lines(self, b: Block, stmts: Sequence[ast3.stmt]) -> None: first, last = stmts[0], stmts[-1] b.line = first.lineno b.column = first.col_offset b.end_line = getattr(last, "end_lineno", None) b.end_column = getattr(last, "end_col_offset", None) if not b.body: return new_first = b.body[0] if isinstance(new_first, (Decorator, OverloadedFuncDef)): # Decorated function lines are different between Python versions. # copy the normalization we do for them to block first lines. b.line = new_first.line b.column = new_first.column def as_block(self, stmts: list[ast3.stmt]) -> Block | None: b = None if stmts: b = Block(self.fix_function_overloads(self.translate_stmt_list(stmts))) self.set_block_lines(b, stmts) return b def as_required_block( self, stmts: list[ast3.stmt], *, can_strip: bool = False, is_coroutine: bool = False ) -> Block: assert stmts # must be non-empty b = Block( self.fix_function_overloads( self.translate_stmt_list(stmts, can_strip=can_strip, is_coroutine=is_coroutine) ) ) self.set_block_lines(b, stmts) return b def fix_function_overloads(self, stmts: list[Statement]) -> list[Statement]: ret: list[Statement] = [] current_overload: list[OverloadPart] = [] current_overload_name: str | None = None seen_unconditional_func_def = False last_if_stmt: IfStmt | None = None last_if_overload: Decorator | FuncDef | OverloadedFuncDef | None = None last_if_stmt_overload_name: str | None = None last_if_unknown_truth_value: IfStmt | None = None skipped_if_stmts: list[IfStmt] = [] for stmt in stmts: if_overload_name: str | None = None if_block_with_overload: Block | None = None if_unknown_truth_value: IfStmt | None = None if isinstance(stmt, IfStmt) and seen_unconditional_func_def is False: # Check IfStmt block to determine if function overloads can be merged if_overload_name = self._check_ifstmt_for_overloads(stmt, current_overload_name) if if_overload_name is not None: (if_block_with_overload, if_unknown_truth_value) = ( self._get_executable_if_block_with_overloads(stmt) ) if ( current_overload_name is not None and isinstance(stmt, (Decorator, FuncDef)) and stmt.name == current_overload_name ): if last_if_stmt is not None: skipped_if_stmts.append(last_if_stmt) if last_if_overload is not None: # Last stmt was an IfStmt with same overload name # Add overloads to current_overload if isinstance(last_if_overload, OverloadedFuncDef): current_overload.extend(last_if_overload.items) else: current_overload.append(last_if_overload) last_if_stmt, last_if_overload = None, None if last_if_unknown_truth_value: self.fail_merge_overload(last_if_unknown_truth_value) last_if_unknown_truth_value = None current_overload.append(stmt) if isinstance(stmt, FuncDef): seen_unconditional_func_def = True elif ( current_overload_name is not None and isinstance(stmt, IfStmt) and if_overload_name == current_overload_name ): # IfStmt only contains stmts relevant to current_overload. # Check if stmts are reachable and add them to current_overload, # otherwise skip IfStmt to allow subsequent overload # or function definitions. skipped_if_stmts.append(stmt) if if_block_with_overload is None: if if_unknown_truth_value is not None: self.fail_merge_overload(if_unknown_truth_value) continue if last_if_overload is not None: # Last stmt was an IfStmt with same overload name # Add overloads to current_overload if isinstance(last_if_overload, OverloadedFuncDef): current_overload.extend(last_if_overload.items) else: current_overload.append(last_if_overload) last_if_stmt, last_if_overload = None, None if isinstance(if_block_with_overload.body[-1], OverloadedFuncDef): skipped_if_stmts.extend(cast(list[IfStmt], if_block_with_overload.body[:-1])) current_overload.extend(if_block_with_overload.body[-1].items) else: current_overload.append( cast(Union[Decorator, FuncDef], if_block_with_overload.body[0]) ) else: if last_if_stmt is not None: ret.append(last_if_stmt) last_if_stmt_overload_name = current_overload_name last_if_stmt, last_if_overload = None, None last_if_unknown_truth_value = None if current_overload and current_overload_name == last_if_stmt_overload_name: # Remove last stmt (IfStmt) from ret if the overload names matched # Only happens if no executable block had been found in IfStmt popped = ret.pop() assert isinstance(popped, IfStmt) skipped_if_stmts.append(popped) if current_overload and skipped_if_stmts: # Add bare IfStmt (without overloads) to ret # Required for mypy to be able to still check conditions for if_stmt in skipped_if_stmts: self._strip_contents_from_if_stmt(if_stmt) ret.append(if_stmt) skipped_if_stmts = [] if len(current_overload) == 1: ret.append(current_overload[0]) elif len(current_overload) > 1: ret.append(OverloadedFuncDef(current_overload)) # If we have multiple decorated functions named "_" next to each, we want to treat # them as a series of regular FuncDefs instead of one OverloadedFuncDef because # most of mypy/mypyc assumes that all the functions in an OverloadedFuncDef are # related, but multiple underscore functions next to each other aren't necessarily # related seen_unconditional_func_def = False if isinstance(stmt, Decorator) and not unnamed_function(stmt.name): current_overload = [stmt] current_overload_name = stmt.name elif isinstance(stmt, IfStmt) and if_overload_name is not None: current_overload = [] current_overload_name = if_overload_name last_if_stmt = stmt last_if_stmt_overload_name = None if if_block_with_overload is not None: skipped_if_stmts.extend( cast(list[IfStmt], if_block_with_overload.body[:-1]) ) last_if_overload = cast( Union[Decorator, FuncDef, OverloadedFuncDef], if_block_with_overload.body[-1], ) last_if_unknown_truth_value = if_unknown_truth_value else: current_overload = [] current_overload_name = None ret.append(stmt) if current_overload and skipped_if_stmts: # Add bare IfStmt (without overloads) to ret # Required for mypy to be able to still check conditions for if_stmt in skipped_if_stmts: self._strip_contents_from_if_stmt(if_stmt) ret.append(if_stmt) if len(current_overload) == 1: ret.append(current_overload[0]) elif len(current_overload) > 1: ret.append(OverloadedFuncDef(current_overload)) elif last_if_overload is not None: ret.append(last_if_overload) elif last_if_stmt is not None: ret.append(last_if_stmt) return ret def _check_ifstmt_for_overloads( self, stmt: IfStmt, current_overload_name: str | None = None ) -> str | None: """Check if IfStmt contains only overloads with the same name. Return overload_name if found, None otherwise. """ # Check that block only contains a single Decorator, FuncDef, or OverloadedFuncDef. # Multiple overloads have already been merged as OverloadedFuncDef. if not ( len(stmt.body[0].body) == 1 and ( isinstance(stmt.body[0].body[0], (Decorator, OverloadedFuncDef)) or current_overload_name is not None and isinstance(stmt.body[0].body[0], FuncDef) ) or len(stmt.body[0].body) > 1 and isinstance(stmt.body[0].body[-1], OverloadedFuncDef) and all(self._is_stripped_if_stmt(if_stmt) for if_stmt in stmt.body[0].body[:-1]) ): return None overload_name = cast( Union[Decorator, FuncDef, OverloadedFuncDef], stmt.body[0].body[-1] ).name if stmt.else_body is None: return overload_name if len(stmt.else_body.body) == 1: # For elif: else_body contains an IfStmt itself -> do a recursive check. if ( isinstance(stmt.else_body.body[0], (Decorator, FuncDef, OverloadedFuncDef)) and stmt.else_body.body[0].name == overload_name ): return overload_name if ( isinstance(stmt.else_body.body[0], IfStmt) and self._check_ifstmt_for_overloads(stmt.else_body.body[0], current_overload_name) == overload_name ): return overload_name return None def _get_executable_if_block_with_overloads( self, stmt: IfStmt ) -> tuple[Block | None, IfStmt | None]: """Return block from IfStmt that will get executed. Return 0 -> A block if sure that alternative blocks are unreachable. 1 -> An IfStmt if the reachability of it can't be inferred, i.e. the truth value is unknown. """ infer_reachability_of_if_statement(stmt, self.options) if stmt.else_body is None and stmt.body[0].is_unreachable is True: # always False condition with no else return None, None if ( stmt.else_body is None or stmt.body[0].is_unreachable is False and stmt.else_body.is_unreachable is False ): # The truth value is unknown, thus not conclusive return None, stmt if stmt.else_body.is_unreachable is True: # else_body will be set unreachable if condition is always True return stmt.body[0], None if stmt.body[0].is_unreachable is True: # body will be set unreachable if condition is always False # else_body can contain an IfStmt itself (for elif) -> do a recursive check if isinstance(stmt.else_body.body[0], IfStmt): return self._get_executable_if_block_with_overloads(stmt.else_body.body[0]) return stmt.else_body, None return None, stmt def _strip_contents_from_if_stmt(self, stmt: IfStmt) -> None: """Remove contents from IfStmt. Needed to still be able to check the conditions after the contents have been merged with the surrounding function overloads. """ if len(stmt.body) == 1: stmt.body[0].body = [] if stmt.else_body and len(stmt.else_body.body) == 1: if isinstance(stmt.else_body.body[0], IfStmt): self._strip_contents_from_if_stmt(stmt.else_body.body[0]) else: stmt.else_body.body = [] def _is_stripped_if_stmt(self, stmt: Statement) -> bool: """Check stmt to make sure it is a stripped IfStmt. See also: _strip_contents_from_if_stmt """ if not isinstance(stmt, IfStmt): return False if not (len(stmt.body) == 1 and len(stmt.body[0].body) == 0): # Body not empty return False if not stmt.else_body or len(stmt.else_body.body) == 0: # No or empty else_body return True # For elif, IfStmt are stored recursively in else_body return self._is_stripped_if_stmt(stmt.else_body.body[0]) def translate_module_id(self, id: str) -> str: """Return the actual, internal module id for a source text id.""" if id == self.options.custom_typing_module: return "typing" return id def visit_Module(self, mod: ast3.Module) -> MypyFile: self.type_ignores = {} for ti in mod.type_ignores: parsed = parse_type_ignore_tag(ti.tag) if parsed is not None: self.type_ignores[ti.lineno] = parsed else: self.fail(message_registry.INVALID_TYPE_IGNORE, ti.lineno, -1, blocker=False) body = self.fix_function_overloads(self.translate_stmt_list(mod.body, ismodule=True)) ret = MypyFile(body, self.imports, False, ignored_lines=self.type_ignores) ret.is_stub = self.is_stub ret.path = self.path return ret # --- stmt --- # FunctionDef(identifier name, arguments args, # stmt* body, expr* decorator_list, expr? returns, string? type_comment) # arguments = (arg* args, arg? vararg, arg* kwonlyargs, expr* kw_defaults, # arg? kwarg, expr* defaults) def visit_FunctionDef(self, n: ast3.FunctionDef) -> FuncDef | Decorator: return self.do_func_def(n) # AsyncFunctionDef(identifier name, arguments args, # stmt* body, expr* decorator_list, expr? returns, string? type_comment) def visit_AsyncFunctionDef(self, n: ast3.AsyncFunctionDef) -> FuncDef | Decorator: return self.do_func_def(n, is_coroutine=True) def do_func_def( self, n: ast3.FunctionDef | ast3.AsyncFunctionDef, is_coroutine: bool = False ) -> FuncDef | Decorator: """Helper shared between visit_FunctionDef and visit_AsyncFunctionDef.""" self.class_and_function_stack.append("D") no_type_check = bool( n.decorator_list and any(is_no_type_check_decorator(d) for d in n.decorator_list) ) lineno = n.lineno args = self.transform_args(n.args, lineno, no_type_check=no_type_check) if special_function_elide_names(n.name): for arg in args: arg.pos_only = True arg_kinds = [arg.kind for arg in args] arg_names = [None if arg.pos_only else arg.variable.name for arg in args] # Type parameters, if using new syntax for generics (PEP 695) explicit_type_params: list[TypeParam] | None = None arg_types: list[Type | None] = [] if no_type_check: arg_types = [None] * len(args) return_type = None elif n.type_comment is not None: try: func_type_ast = ast3_parse(n.type_comment, "", "func_type") assert isinstance(func_type_ast, FunctionType) # for ellipsis arg if ( len(func_type_ast.argtypes) == 1 and isinstance(func_type_ast.argtypes[0], Constant) and func_type_ast.argtypes[0].value is Ellipsis ): if n.returns: # PEP 484 disallows both type annotations and type comments self.fail( message_registry.DUPLICATE_TYPE_SIGNATURES, lineno, n.col_offset, blocker=False, ) arg_types = [ ( a.type_annotation if a.type_annotation is not None else AnyType(TypeOfAny.unannotated) ) for a in args ] else: # PEP 484 disallows both type annotations and type comments if n.returns or any(a.type_annotation is not None for a in args): self.fail( message_registry.DUPLICATE_TYPE_SIGNATURES, lineno, n.col_offset, blocker=False, ) translated_args: list[Type] = TypeConverter( self.errors, line=lineno, override_column=n.col_offset ).translate_expr_list(func_type_ast.argtypes) # Use a cast to work around `list` invariance arg_types = cast(list[Optional[Type]], translated_args) return_type = TypeConverter(self.errors, line=lineno).visit(func_type_ast.returns) # add implicit self type in_method_scope = self.class_and_function_stack[-2:] == ["C", "D"] if in_method_scope and len(arg_types) < len(args): arg_types.insert(0, AnyType(TypeOfAny.special_form)) except SyntaxError: stripped_type = n.type_comment.split("#", 2)[0].strip() err_msg = message_registry.TYPE_COMMENT_SYNTAX_ERROR_VALUE.format(stripped_type) self.fail(err_msg, lineno, n.col_offset, blocker=False) if n.type_comment and n.type_comment[0] not in ["(", "#"]: self.note( "Suggestion: wrap argument types in parentheses", lineno, n.col_offset ) arg_types = [AnyType(TypeOfAny.from_error)] * len(args) return_type = AnyType(TypeOfAny.from_error) else: if sys.version_info >= (3, 12) and n.type_params: explicit_type_params = self.translate_type_params(n.type_params) arg_types = [a.type_annotation for a in args] return_type = TypeConverter( self.errors, line=n.returns.lineno if n.returns else lineno ).visit(n.returns) for arg, arg_type in zip(args, arg_types): self.set_type_optional(arg_type, arg.initializer) func_type = None if any(arg_types) or return_type: if len(arg_types) != 1 and any(isinstance(t, EllipsisType) for t in arg_types): self.fail( message_registry.ELLIPSIS_WITH_OTHER_TYPEARGS, lineno, n.col_offset, blocker=False, ) elif len(arg_types) > len(arg_kinds): self.fail( message_registry.TYPE_SIGNATURE_TOO_MANY_ARGS, lineno, n.col_offset, blocker=False, ) elif len(arg_types) < len(arg_kinds): self.fail( message_registry.TYPE_SIGNATURE_TOO_FEW_ARGS, lineno, n.col_offset, blocker=False, ) else: func_type = CallableType( [a if a is not None else AnyType(TypeOfAny.unannotated) for a in arg_types], arg_kinds, arg_names, return_type if return_type is not None else AnyType(TypeOfAny.unannotated), _dummy_fallback, ) # End position is always the same. end_line = getattr(n, "end_lineno", None) end_column = getattr(n, "end_col_offset", None) self.class_and_function_stack.pop() self.class_and_function_stack.append("F") body = self.as_required_block(n.body, can_strip=True, is_coroutine=is_coroutine) func_def = FuncDef(n.name, args, body, func_type, explicit_type_params) if isinstance(func_def.type, CallableType): # semanal.py does some in-place modifications we want to avoid func_def.unanalyzed_type = func_def.type.copy_modified() if is_coroutine: func_def.is_coroutine = True if func_type is not None: func_type.definition = func_def func_type.set_line(lineno) if n.decorator_list: var = Var(func_def.name) var.is_ready = False var.set_line(lineno) func_def.is_decorated = True self.set_line(func_def, n) deco = Decorator(func_def, self.translate_expr_list(n.decorator_list), var) first = n.decorator_list[0] deco.set_line(first.lineno, first.col_offset, end_line, end_column) retval: FuncDef | Decorator = deco else: self.set_line(func_def, n) retval = func_def if self.options.include_docstrings: func_def.docstring = ast3.get_docstring(n, clean=False) self.class_and_function_stack.pop() return retval def set_type_optional(self, type: Type | None, initializer: Expression | None) -> None: if not self.options.implicit_optional: return # Indicate that type should be wrapped in an Optional if arg is initialized to None. optional = isinstance(initializer, NameExpr) and initializer.name == "None" if isinstance(type, UnboundType): type.optional = optional def transform_args( self, args: ast3.arguments, line: int, no_type_check: bool = False ) -> list[Argument]: new_args = [] names: list[ast3.arg] = [] posonlyargs = getattr(args, "posonlyargs", cast(list[ast3.arg], [])) args_args = posonlyargs + args.args args_defaults = args.defaults num_no_defaults = len(args_args) - len(args_defaults) # positional arguments without defaults for i, a in enumerate(args_args[:num_no_defaults]): pos_only = i < len(posonlyargs) new_args.append(self.make_argument(a, None, ARG_POS, no_type_check, pos_only)) names.append(a) # positional arguments with defaults for i, (a, d) in enumerate(zip(args_args[num_no_defaults:], args_defaults)): pos_only = num_no_defaults + i < len(posonlyargs) new_args.append(self.make_argument(a, d, ARG_OPT, no_type_check, pos_only)) names.append(a) # *arg if args.vararg is not None: new_args.append(self.make_argument(args.vararg, None, ARG_STAR, no_type_check)) names.append(args.vararg) # keyword-only arguments with defaults for a, kd in zip(args.kwonlyargs, args.kw_defaults): new_args.append( self.make_argument( a, kd, ARG_NAMED if kd is None else ARG_NAMED_OPT, no_type_check ) ) names.append(a) # **kwarg if args.kwarg is not None: new_args.append(self.make_argument(args.kwarg, None, ARG_STAR2, no_type_check)) names.append(args.kwarg) check_arg_names([arg.variable.name for arg in new_args], names, self.fail_arg) return new_args def make_argument( self, arg: ast3.arg, default: ast3.expr | None, kind: ArgKind, no_type_check: bool, pos_only: bool = False, ) -> Argument: if no_type_check: arg_type = None else: annotation = arg.annotation type_comment = arg.type_comment if annotation is not None and type_comment is not None: self.fail( message_registry.DUPLICATE_TYPE_SIGNATURES, arg.lineno, arg.col_offset, blocker=False, ) arg_type = None if annotation is not None: arg_type = TypeConverter(self.errors, line=arg.lineno).visit(annotation) else: arg_type = self.translate_type_comment(arg, type_comment) if argument_elide_name(arg.arg): pos_only = True var = Var(arg.arg, arg_type) var.is_inferred = False argument = Argument(var, arg_type, self.visit(default), kind, pos_only) argument.set_line( arg.lineno, arg.col_offset, getattr(arg, "end_lineno", None), getattr(arg, "end_col_offset", None), ) return argument def fail_arg(self, msg: str, arg: ast3.arg) -> None: self.fail(ErrorMessage(msg), arg.lineno, arg.col_offset, blocker=True) # ClassDef(identifier name, # expr* bases, # keyword* keywords, # stmt* body, # expr* decorator_list) def visit_ClassDef(self, n: ast3.ClassDef) -> ClassDef: self.class_and_function_stack.append("C") keywords = [(kw.arg, self.visit(kw.value)) for kw in n.keywords if kw.arg] # Type parameters, if using new syntax for generics (PEP 695) explicit_type_params: list[TypeParam] | None = None if sys.version_info >= (3, 12) and n.type_params: explicit_type_params = self.translate_type_params(n.type_params) cdef = ClassDef( n.name, self.as_required_block(n.body), None, self.translate_expr_list(n.bases), metaclass=dict(keywords).get("metaclass"), keywords=keywords, type_args=explicit_type_params, ) cdef.decorators = self.translate_expr_list(n.decorator_list) self.set_line(cdef, n) if self.options.include_docstrings: cdef.docstring = ast3.get_docstring(n, clean=False) cdef.column = n.col_offset cdef.end_line = getattr(n, "end_lineno", None) cdef.end_column = getattr(n, "end_col_offset", None) self.class_and_function_stack.pop() return cdef def validate_type_param(self, type_param: ast_TypeVar) -> None: incorrect_expr = find_disallowed_expression_in_annotation_scope(type_param.bound) if incorrect_expr is None: return if isinstance(incorrect_expr, (ast3.Yield, ast3.YieldFrom)): self.fail( message_registry.TYPE_VAR_YIELD_EXPRESSION_IN_BOUND, type_param.lineno, type_param.col_offset, blocker=True, ) if isinstance(incorrect_expr, ast3.NamedExpr): self.fail( message_registry.TYPE_VAR_NAMED_EXPRESSION_IN_BOUND, type_param.lineno, type_param.col_offset, blocker=True, ) if isinstance(incorrect_expr, ast3.Await): self.fail( message_registry.TYPE_VAR_AWAIT_EXPRESSION_IN_BOUND, type_param.lineno, type_param.col_offset, blocker=True, ) def translate_type_params(self, type_params: list[Any]) -> list[TypeParam]: explicit_type_params = [] for p in type_params: bound: Type | None = None values: list[Type] = [] default: Type | None = None if sys.version_info >= (3, 13): default = TypeConverter(self.errors, line=p.lineno).visit(p.default_value) if isinstance(p, ast_ParamSpec): # type: ignore[misc] explicit_type_params.append(TypeParam(p.name, PARAM_SPEC_KIND, None, [], default)) elif isinstance(p, ast_TypeVarTuple): # type: ignore[misc] explicit_type_params.append( TypeParam(p.name, TYPE_VAR_TUPLE_KIND, None, [], default) ) else: if isinstance(p.bound, ast3.Tuple): if len(p.bound.elts) < 2: self.fail( message_registry.TYPE_VAR_TOO_FEW_CONSTRAINED_TYPES, p.lineno, p.col_offset, blocker=False, ) else: conv = TypeConverter(self.errors, line=p.lineno) values = [conv.visit(t) for t in p.bound.elts] elif p.bound is not None: self.validate_type_param(p) bound = TypeConverter(self.errors, line=p.lineno).visit(p.bound) explicit_type_params.append( TypeParam(p.name, TYPE_VAR_KIND, bound, values, default) ) return explicit_type_params # Return(expr? value) def visit_Return(self, n: ast3.Return) -> ReturnStmt: node = ReturnStmt(self.visit(n.value)) return self.set_line(node, n) # Delete(expr* targets) def visit_Delete(self, n: ast3.Delete) -> DelStmt: if len(n.targets) > 1: tup = TupleExpr(self.translate_expr_list(n.targets)) tup.set_line(n.lineno) node = DelStmt(tup) else: node = DelStmt(self.visit(n.targets[0])) return self.set_line(node, n) # Assign(expr* targets, expr? value, string? type_comment, expr? annotation) def visit_Assign(self, n: ast3.Assign) -> AssignmentStmt: lvalues = self.translate_expr_list(n.targets) rvalue = self.visit(n.value) typ = self.translate_type_comment(n, n.type_comment) s = AssignmentStmt(lvalues, rvalue, type=typ, new_syntax=False) return self.set_line(s, n) # AnnAssign(expr target, expr annotation, expr? value, int simple) def visit_AnnAssign(self, n: ast3.AnnAssign) -> AssignmentStmt: line = n.lineno if n.value is None: # always allow 'x: int' rvalue: Expression = TempNode(AnyType(TypeOfAny.special_form), no_rhs=True) self.set_line(rvalue, n) else: rvalue = self.visit(n.value) typ = TypeConverter(self.errors, line=line).visit(n.annotation) assert typ is not None typ.column = n.annotation.col_offset s = AssignmentStmt([self.visit(n.target)], rvalue, type=typ, new_syntax=True) return self.set_line(s, n) # AugAssign(expr target, operator op, expr value) def visit_AugAssign(self, n: ast3.AugAssign) -> OperatorAssignmentStmt: s = OperatorAssignmentStmt( self.from_operator(n.op), self.visit(n.target), self.visit(n.value) ) return self.set_line(s, n) # For(expr target, expr iter, stmt* body, stmt* orelse, string? type_comment) def visit_For(self, n: ast3.For) -> ForStmt: target_type = self.translate_type_comment(n, n.type_comment) node = ForStmt( self.visit(n.target), self.visit(n.iter), self.as_required_block(n.body), self.as_block(n.orelse), target_type, ) return self.set_line(node, n) # AsyncFor(expr target, expr iter, stmt* body, stmt* orelse, string? type_comment) def visit_AsyncFor(self, n: ast3.AsyncFor) -> ForStmt: target_type = self.translate_type_comment(n, n.type_comment) node = ForStmt( self.visit(n.target), self.visit(n.iter), self.as_required_block(n.body), self.as_block(n.orelse), target_type, ) node.is_async = True return self.set_line(node, n) # While(expr test, stmt* body, stmt* orelse) def visit_While(self, n: ast3.While) -> WhileStmt: node = WhileStmt( self.visit(n.test), self.as_required_block(n.body), self.as_block(n.orelse) ) return self.set_line(node, n) # If(expr test, stmt* body, stmt* orelse) def visit_If(self, n: ast3.If) -> IfStmt: node = IfStmt( [self.visit(n.test)], [self.as_required_block(n.body)], self.as_block(n.orelse) ) return self.set_line(node, n) # With(withitem* items, stmt* body, string? type_comment) def visit_With(self, n: ast3.With) -> WithStmt: target_type = self.translate_type_comment(n, n.type_comment) node = WithStmt( [self.visit(i.context_expr) for i in n.items], [self.visit(i.optional_vars) for i in n.items], self.as_required_block(n.body), target_type, ) return self.set_line(node, n) # AsyncWith(withitem* items, stmt* body, string? type_comment) def visit_AsyncWith(self, n: ast3.AsyncWith) -> WithStmt: target_type = self.translate_type_comment(n, n.type_comment) s = WithStmt( [self.visit(i.context_expr) for i in n.items], [self.visit(i.optional_vars) for i in n.items], self.as_required_block(n.body), target_type, ) s.is_async = True return self.set_line(s, n) # Raise(expr? exc, expr? cause) def visit_Raise(self, n: ast3.Raise) -> RaiseStmt: node = RaiseStmt(self.visit(n.exc), self.visit(n.cause)) return self.set_line(node, n) # Try(stmt* body, excepthandler* handlers, stmt* orelse, stmt* finalbody) def visit_Try(self, n: ast3.Try) -> TryStmt: vs = [ self.set_line(NameExpr(h.name), h) if h.name is not None else None for h in n.handlers ] types = [self.visit(h.type) for h in n.handlers] handlers = [self.as_required_block(h.body) for h in n.handlers] node = TryStmt( self.as_required_block(n.body), vs, types, handlers, self.as_block(n.orelse), self.as_block(n.finalbody), ) return self.set_line(node, n) def visit_TryStar(self, n: TryStar) -> TryStmt: vs = [ self.set_line(NameExpr(h.name), h) if h.name is not None else None for h in n.handlers ] types = [self.visit(h.type) for h in n.handlers] handlers = [self.as_required_block(h.body) for h in n.handlers] node = TryStmt( self.as_required_block(n.body), vs, types, handlers, self.as_block(n.orelse), self.as_block(n.finalbody), ) node.is_star = True return self.set_line(node, n) # Assert(expr test, expr? msg) def visit_Assert(self, n: ast3.Assert) -> AssertStmt: node = AssertStmt(self.visit(n.test), self.visit(n.msg)) return self.set_line(node, n) # Import(alias* names) def visit_Import(self, n: ast3.Import) -> Import: names: list[tuple[str, str | None]] = [] for alias in n.names: name = self.translate_module_id(alias.name) asname = alias.asname if asname is None and name != alias.name: # if the module name has been translated (and it's not already # an explicit import-as), make it an implicit import-as the # original name asname = alias.name names.append((name, asname)) i = Import(names) self.imports.append(i) return self.set_line(i, n) # ImportFrom(identifier? module, alias* names, int? level) def visit_ImportFrom(self, n: ast3.ImportFrom) -> ImportBase: assert n.level is not None if len(n.names) == 1 and n.names[0].name == "*": mod = n.module if n.module is not None else "" i: ImportBase = ImportAll(mod, n.level) else: i = ImportFrom( self.translate_module_id(n.module) if n.module is not None else "", n.level, [(a.name, a.asname) for a in n.names], ) self.imports.append(i) return self.set_line(i, n) # Global(identifier* names) def visit_Global(self, n: ast3.Global) -> GlobalDecl: g = GlobalDecl(n.names) return self.set_line(g, n) # Nonlocal(identifier* names) def visit_Nonlocal(self, n: ast3.Nonlocal) -> NonlocalDecl: d = NonlocalDecl(n.names) return self.set_line(d, n) # Expr(expr value) def visit_Expr(self, n: ast3.Expr) -> ExpressionStmt: value = self.visit(n.value) node = ExpressionStmt(value) return self.set_line(node, n) # Pass def visit_Pass(self, n: ast3.Pass) -> PassStmt: s = PassStmt() return self.set_line(s, n) # Break def visit_Break(self, n: ast3.Break) -> BreakStmt: s = BreakStmt() return self.set_line(s, n) # Continue def visit_Continue(self, n: ast3.Continue) -> ContinueStmt: s = ContinueStmt() return self.set_line(s, n) # --- expr --- def visit_NamedExpr(self, n: NamedExpr) -> AssignmentExpr: s = AssignmentExpr(self.visit(n.target), self.visit(n.value)) return self.set_line(s, n) # BoolOp(boolop op, expr* values) def visit_BoolOp(self, n: ast3.BoolOp) -> OpExpr: # mypy translates (1 and 2 and 3) as (1 and (2 and 3)) assert len(n.values) >= 2 op_node = n.op if isinstance(op_node, ast3.And): op = "and" elif isinstance(op_node, ast3.Or): op = "or" else: raise RuntimeError("unknown BoolOp " + str(type(n))) # potentially inefficient! return self.group(op, self.translate_expr_list(n.values), n) def group(self, op: str, vals: list[Expression], n: ast3.expr) -> OpExpr: if len(vals) == 2: e = OpExpr(op, vals[0], vals[1]) else: e = OpExpr(op, vals[0], self.group(op, vals[1:], n)) return self.set_line(e, n) # BinOp(expr left, operator op, expr right) def visit_BinOp(self, n: ast3.BinOp) -> OpExpr: op = self.from_operator(n.op) if op is None: raise RuntimeError("cannot translate BinOp " + str(type(n.op))) e = OpExpr(op, self.visit(n.left), self.visit(n.right)) return self.set_line(e, n) # UnaryOp(unaryop op, expr operand) def visit_UnaryOp(self, n: ast3.UnaryOp) -> UnaryExpr: op = None if isinstance(n.op, ast3.Invert): op = "~" elif isinstance(n.op, ast3.Not): op = "not" elif isinstance(n.op, ast3.UAdd): op = "+" elif isinstance(n.op, ast3.USub): op = "-" if op is None: raise RuntimeError("cannot translate UnaryOp " + str(type(n.op))) e = UnaryExpr(op, self.visit(n.operand)) return self.set_line(e, n) # Lambda(arguments args, expr body) def visit_Lambda(self, n: ast3.Lambda) -> LambdaExpr: body = ast3.Return(n.body) body.lineno = n.body.lineno body.col_offset = n.body.col_offset self.class_and_function_stack.append("L") e = LambdaExpr(self.transform_args(n.args, n.lineno), self.as_required_block([body])) self.class_and_function_stack.pop() e.set_line(n.lineno, n.col_offset) # Overrides set_line -- can't use self.set_line return e # IfExp(expr test, expr body, expr orelse) def visit_IfExp(self, n: ast3.IfExp) -> ConditionalExpr: e = ConditionalExpr(self.visit(n.test), self.visit(n.body), self.visit(n.orelse)) return self.set_line(e, n) # Dict(expr* keys, expr* values) def visit_Dict(self, n: ast3.Dict) -> DictExpr: e = DictExpr( list(zip(self.translate_opt_expr_list(n.keys), self.translate_expr_list(n.values))) ) return self.set_line(e, n) # Set(expr* elts) def visit_Set(self, n: ast3.Set) -> SetExpr: e = SetExpr(self.translate_expr_list(n.elts)) return self.set_line(e, n) # ListComp(expr elt, comprehension* generators) def visit_ListComp(self, n: ast3.ListComp) -> ListComprehension: e = ListComprehension(self.visit_GeneratorExp(cast(ast3.GeneratorExp, n))) return self.set_line(e, n) # SetComp(expr elt, comprehension* generators) def visit_SetComp(self, n: ast3.SetComp) -> SetComprehension: e = SetComprehension(self.visit_GeneratorExp(cast(ast3.GeneratorExp, n))) return self.set_line(e, n) # DictComp(expr key, expr value, comprehension* generators) def visit_DictComp(self, n: ast3.DictComp) -> DictionaryComprehension: targets = [self.visit(c.target) for c in n.generators] iters = [self.visit(c.iter) for c in n.generators] ifs_list = [self.translate_expr_list(c.ifs) for c in n.generators] is_async = [bool(c.is_async) for c in n.generators] e = DictionaryComprehension( self.visit(n.key), self.visit(n.value), targets, iters, ifs_list, is_async ) return self.set_line(e, n) # GeneratorExp(expr elt, comprehension* generators) def visit_GeneratorExp(self, n: ast3.GeneratorExp) -> GeneratorExpr: targets = [self.visit(c.target) for c in n.generators] iters = [self.visit(c.iter) for c in n.generators] ifs_list = [self.translate_expr_list(c.ifs) for c in n.generators] is_async = [bool(c.is_async) for c in n.generators] e = GeneratorExpr(self.visit(n.elt), targets, iters, ifs_list, is_async) return self.set_line(e, n) # Await(expr value) def visit_Await(self, n: ast3.Await) -> AwaitExpr: v = self.visit(n.value) e = AwaitExpr(v) return self.set_line(e, n) # Yield(expr? value) def visit_Yield(self, n: ast3.Yield) -> YieldExpr: e = YieldExpr(self.visit(n.value)) return self.set_line(e, n) # YieldFrom(expr value) def visit_YieldFrom(self, n: ast3.YieldFrom) -> YieldFromExpr: e = YieldFromExpr(self.visit(n.value)) return self.set_line(e, n) # Compare(expr left, cmpop* ops, expr* comparators) def visit_Compare(self, n: ast3.Compare) -> ComparisonExpr: operators = [self.from_comp_operator(o) for o in n.ops] operands = self.translate_expr_list([n.left] + n.comparators) e = ComparisonExpr(operators, operands) return self.set_line(e, n) # Call(expr func, expr* args, keyword* keywords) # keyword = (identifier? arg, expr value) def visit_Call(self, n: Call) -> CallExpr: args = n.args keywords = n.keywords keyword_names = [k.arg for k in keywords] arg_types = self.translate_expr_list( [a.value if isinstance(a, Starred) else a for a in args] + [k.value for k in keywords] ) arg_kinds = [ARG_STAR if type(a) is Starred else ARG_POS for a in args] + [ ARG_STAR2 if arg is None else ARG_NAMED for arg in keyword_names ] e = CallExpr( self.visit(n.func), arg_types, arg_kinds, cast("list[Optional[str]]", [None] * len(args)) + keyword_names, ) return self.set_line(e, n) # Constant(object value) -- a constant, in Python 3.8. def visit_Constant(self, n: Constant) -> Any: val = n.value e: Any = None if val is None: e = NameExpr("None") elif isinstance(val, str): e = StrExpr(val) elif isinstance(val, bytes): e = BytesExpr(bytes_to_human_readable_repr(val)) elif isinstance(val, bool): # Must check before int! e = NameExpr(str(val)) elif isinstance(val, int): e = IntExpr(val) elif isinstance(val, float): e = FloatExpr(val) elif isinstance(val, complex): e = ComplexExpr(val) elif val is Ellipsis: e = EllipsisExpr() else: raise RuntimeError("Constant not implemented for " + str(type(val))) return self.set_line(e, n) # JoinedStr(expr* values) def visit_JoinedStr(self, n: ast3.JoinedStr) -> Expression: # Each of n.values is a str or FormattedValue; we just concatenate # them all using ''.join. empty_string = StrExpr("") empty_string.set_line(n.lineno, n.col_offset) strs_to_join = ListExpr(self.translate_expr_list(n.values)) strs_to_join.set_line(empty_string) # Don't make unnecessary join call if there is only one str to join if len(strs_to_join.items) == 1: return self.set_line(strs_to_join.items[0], n) elif len(strs_to_join.items) > 1: last = strs_to_join.items[-1] if isinstance(last, StrExpr) and last.value == "": # 3.12 can add an empty literal at the end. Delete it for consistency # between Python versions. del strs_to_join.items[-1:] join_method = MemberExpr(empty_string, "join") join_method.set_line(empty_string) result_expression = CallExpr(join_method, [strs_to_join], [ARG_POS], [None]) return self.set_line(result_expression, n) # FormattedValue(expr value) def visit_FormattedValue(self, n: ast3.FormattedValue) -> Expression: # A FormattedValue is a component of a JoinedStr, or it can exist # on its own. We translate them to individual '{}'.format(value) # calls. Format specifier and conversion information is passed along # to allow mypyc to support f-strings with format specifiers and conversions. val_exp = self.visit(n.value) val_exp.set_line(n.lineno, n.col_offset) conv_str = "" if n.conversion < 0 else "!" + chr(n.conversion) format_string = StrExpr("{" + conv_str + ":{}}") format_spec_exp = self.visit(n.format_spec) if n.format_spec is not None else StrExpr("") format_string.set_line(n.lineno, n.col_offset) format_method = MemberExpr(format_string, "format") format_method.set_line(format_string) result_expression = CallExpr( format_method, [val_exp, format_spec_exp], [ARG_POS, ARG_POS], [None, None] ) return self.set_line(result_expression, n) # Attribute(expr value, identifier attr, expr_context ctx) def visit_Attribute(self, n: Attribute) -> MemberExpr | SuperExpr: value = n.value member_expr = MemberExpr(self.visit(value), n.attr) obj = member_expr.expr if ( isinstance(obj, CallExpr) and isinstance(obj.callee, NameExpr) and obj.callee.name == "super" ): e: MemberExpr | SuperExpr = SuperExpr(member_expr.name, obj) else: e = member_expr return self.set_line(e, n) # Subscript(expr value, slice slice, expr_context ctx) def visit_Subscript(self, n: ast3.Subscript) -> IndexExpr: e = IndexExpr(self.visit(n.value), self.visit(n.slice)) return self.set_line(e, n) # Starred(expr value, expr_context ctx) def visit_Starred(self, n: Starred) -> StarExpr: e = StarExpr(self.visit(n.value)) return self.set_line(e, n) # Name(identifier id, expr_context ctx) def visit_Name(self, n: Name) -> NameExpr: e = NameExpr(n.id) return self.set_line(e, n) # List(expr* elts, expr_context ctx) def visit_List(self, n: ast3.List) -> ListExpr | TupleExpr: expr_list: list[Expression] = [self.visit(e) for e in n.elts] if isinstance(n.ctx, ast3.Store): # [x, y] = z and (x, y) = z means exactly the same thing e: ListExpr | TupleExpr = TupleExpr(expr_list) else: e = ListExpr(expr_list) return self.set_line(e, n) # Tuple(expr* elts, expr_context ctx) def visit_Tuple(self, n: ast3.Tuple) -> TupleExpr: e = TupleExpr(self.translate_expr_list(n.elts)) return self.set_line(e, n) # --- slice --- # Slice(expr? lower, expr? upper, expr? step) def visit_Slice(self, n: ast3.Slice) -> SliceExpr: e = SliceExpr(self.visit(n.lower), self.visit(n.upper), self.visit(n.step)) return self.set_line(e, n) # ExtSlice(slice* dims) def visit_ExtSlice(self, n: ast3.ExtSlice) -> TupleExpr: # cast for mypyc's benefit on Python 3.9 return TupleExpr(self.translate_expr_list(cast(Any, n).dims)) # Index(expr value) def visit_Index(self, n: Index) -> Node: # cast for mypyc's benefit on Python 3.9 value = self.visit(cast(Any, n).value) assert isinstance(value, Node) return value # Match(expr subject, match_case* cases) # python 3.10 and later def visit_Match(self, n: Match) -> MatchStmt: node = MatchStmt( self.visit(n.subject), [self.visit(c.pattern) for c in n.cases], [self.visit(c.guard) for c in n.cases], [self.as_required_block(c.body) for c in n.cases], ) return self.set_line(node, n) def visit_MatchValue(self, n: MatchValue) -> ValuePattern: node = ValuePattern(self.visit(n.value)) return self.set_line(node, n) def visit_MatchSingleton(self, n: MatchSingleton) -> SingletonPattern: node = SingletonPattern(n.value) return self.set_line(node, n) def visit_MatchSequence(self, n: MatchSequence) -> SequencePattern: patterns = [self.visit(p) for p in n.patterns] stars = [p for p in patterns if isinstance(p, StarredPattern)] assert len(stars) < 2 node = SequencePattern(patterns) return self.set_line(node, n) def visit_MatchStar(self, n: MatchStar) -> StarredPattern: if n.name is None: node = StarredPattern(None) else: name = self.set_line(NameExpr(n.name), n) node = StarredPattern(name) return self.set_line(node, n) def visit_MatchMapping(self, n: MatchMapping) -> MappingPattern: keys = [self.visit(k) for k in n.keys] values = [self.visit(v) for v in n.patterns] if n.rest is None: rest = None else: rest = NameExpr(n.rest) node = MappingPattern(keys, values, rest) return self.set_line(node, n) def visit_MatchClass(self, n: MatchClass) -> ClassPattern: class_ref = self.visit(n.cls) assert isinstance(class_ref, RefExpr) positionals = [self.visit(p) for p in n.patterns] keyword_keys = n.kwd_attrs keyword_values = [self.visit(p) for p in n.kwd_patterns] node = ClassPattern(class_ref, positionals, keyword_keys, keyword_values) return self.set_line(node, n) # MatchAs(expr pattern, identifier name) def visit_MatchAs(self, n: MatchAs) -> AsPattern: if n.name is None: name = None else: name = NameExpr(n.name) name = self.set_line(name, n) node = AsPattern(self.visit(n.pattern), name) return self.set_line(node, n) # MatchOr(expr* pattern) def visit_MatchOr(self, n: MatchOr) -> OrPattern: node = OrPattern([self.visit(pattern) for pattern in n.patterns]) return self.set_line(node, n) def validate_type_alias(self, n: ast_TypeAlias) -> None: incorrect_expr = find_disallowed_expression_in_annotation_scope(n.value) if incorrect_expr is None: return if isinstance(incorrect_expr, (ast3.Yield, ast3.YieldFrom)): self.fail( message_registry.TYPE_ALIAS_WITH_YIELD_EXPRESSION, n.lineno, n.col_offset, blocker=True, ) if isinstance(incorrect_expr, ast3.NamedExpr): self.fail( message_registry.TYPE_ALIAS_WITH_NAMED_EXPRESSION, n.lineno, n.col_offset, blocker=True, ) if isinstance(incorrect_expr, ast3.Await): self.fail( message_registry.TYPE_ALIAS_WITH_AWAIT_EXPRESSION, n.lineno, n.col_offset, blocker=True, ) # TypeAlias(identifier name, type_param* type_params, expr value) def visit_TypeAlias(self, n: ast_TypeAlias) -> TypeAliasStmt | AssignmentStmt: node: TypeAliasStmt | AssignmentStmt type_params = self.translate_type_params(n.type_params) self.validate_type_alias(n) value = self.visit(n.value) # Since the value is evaluated lazily, wrap the value inside a lambda. # This helps mypyc. ret = ReturnStmt(value) self.set_line(ret, n.value) value_func = LambdaExpr(body=Block([ret])) self.set_line(value_func, n.value) node = TypeAliasStmt(self.visit_Name(n.name), type_params, value_func) return self.set_line(node, n) class TypeConverter: def __init__( self, errors: Errors | None, line: int = -1, override_column: int = -1, is_evaluated: bool = True, ) -> None: self.errors = errors self.line = line self.override_column = override_column self.node_stack: list[AST] = [] self.is_evaluated = is_evaluated def convert_column(self, column: int) -> int: """Apply column override if defined; otherwise return column. Column numbers are sometimes incorrect in the AST and the column override can be used to work around that. """ if self.override_column < 0: return column else: return self.override_column def invalid_type(self, node: AST, note: str | None = None) -> RawExpressionType: """Constructs a type representing some expression that normally forms an invalid type. For example, if we see a type hint that says "3 + 4", we would transform that expression into a RawExpressionType. The semantic analysis layer will report an "Invalid type" error when it encounters this type, along with the given note if one is provided. See RawExpressionType's docstring for more details on how it's used. """ return RawExpressionType( None, "typing.Any", line=self.line, column=getattr(node, "col_offset", -1), note=note ) @overload def visit(self, node: ast3.expr) -> ProperType: ... @overload def visit(self, node: AST | None) -> ProperType | None: ... def visit(self, node: AST | None) -> ProperType | None: """Modified visit -- keep track of the stack of nodes""" if node is None: return None self.node_stack.append(node) try: method = "visit_" + node.__class__.__name__ visitor = getattr(self, method, None) if visitor is not None: typ = visitor(node) assert isinstance(typ, ProperType) return typ else: return self.invalid_type(node) finally: self.node_stack.pop() def parent(self) -> AST | None: """Return the AST node above the one we are processing""" if len(self.node_stack) < 2: return None return self.node_stack[-2] def fail(self, msg: ErrorMessage, line: int, column: int) -> None: if self.errors: self.errors.report(line, column, msg.value, blocker=True, code=msg.code) def note(self, msg: str, line: int, column: int) -> None: if self.errors: self.errors.report(line, column, msg, severity="note", code=codes.SYNTAX) def translate_expr_list(self, l: Sequence[ast3.expr]) -> list[Type]: return [self.visit(e) for e in l] def visit_Call(self, e: Call) -> Type: # Parse the arg constructor f = e.func constructor = stringify_name(f) if not isinstance(self.parent(), ast3.List): note = None if constructor: note = "Suggestion: use {0}[...] instead of {0}(...)".format(constructor) return self.invalid_type(e, note=note) if not constructor: self.fail(message_registry.ARG_CONSTRUCTOR_NAME_EXPECTED, e.lineno, e.col_offset) name: str | None = None default_type = AnyType(TypeOfAny.special_form) typ: Type = default_type for i, arg in enumerate(e.args): if i == 0: converted = self.visit(arg) assert converted is not None typ = converted elif i == 1: name = self._extract_argument_name(arg) else: self.fail(message_registry.ARG_CONSTRUCTOR_TOO_MANY_ARGS, f.lineno, f.col_offset) for k in e.keywords: value = k.value if k.arg == "name": if name is not None: self.fail( message_registry.MULTIPLE_VALUES_FOR_NAME_KWARG.format(constructor), f.lineno, f.col_offset, ) name = self._extract_argument_name(value) elif k.arg == "type": if typ is not default_type: self.fail( message_registry.MULTIPLE_VALUES_FOR_TYPE_KWARG.format(constructor), f.lineno, f.col_offset, ) converted = self.visit(value) assert converted is not None typ = converted else: self.fail( message_registry.ARG_CONSTRUCTOR_UNEXPECTED_ARG.format(k.arg), value.lineno, value.col_offset, ) return CallableArgument(typ, name, constructor, e.lineno, e.col_offset) def translate_argument_list(self, l: Sequence[ast3.expr]) -> TypeList: return TypeList([self.visit(e) for e in l], line=self.line) def _extract_argument_name(self, n: ast3.expr) -> str | None: if isinstance(n, Constant) and isinstance(n.value, str): return n.value.strip() elif isinstance(n, Constant) and n.value is None: return None self.fail( message_registry.ARG_NAME_EXPECTED_STRING_LITERAL.format(type(n).__name__), self.line, 0, ) return None def visit_Name(self, n: Name) -> Type: return UnboundType(n.id, line=self.line, column=self.convert_column(n.col_offset)) def visit_BinOp(self, n: ast3.BinOp) -> Type: if not isinstance(n.op, ast3.BitOr): return self.invalid_type(n) left = self.visit(n.left) right = self.visit(n.right) return UnionType( [left, right], line=self.line, column=self.convert_column(n.col_offset), is_evaluated=self.is_evaluated, uses_pep604_syntax=True, ) def visit_Constant(self, n: Constant) -> Type: val = n.value if val is None: # None is a type. return UnboundType("None", line=self.line) if isinstance(val, str): # Parse forward reference. return parse_type_string(val, "builtins.str", self.line, n.col_offset) if val is Ellipsis: # '...' is valid in some types. return EllipsisType(line=self.line) if isinstance(val, bool): # Special case for True/False. return RawExpressionType(val, "builtins.bool", line=self.line) if isinstance(val, (int, float, complex)): return self.numeric_type(val, n) if isinstance(val, bytes): contents = bytes_to_human_readable_repr(val) return RawExpressionType(contents, "builtins.bytes", self.line, column=n.col_offset) # Everything else is invalid. return self.invalid_type(n) # UnaryOp(op, operand) def visit_UnaryOp(self, n: UnaryOp) -> Type: # We support specifically Literal[-4], Literal[+4], and nothing else. # For example, Literal[~6] or Literal[not False] is not supported. typ = self.visit(n.operand) if ( isinstance(typ, RawExpressionType) # Use type() because we do not want to allow bools. and type(typ.literal_value) is int ): if isinstance(n.op, USub): typ.literal_value *= -1 return typ if isinstance(n.op, UAdd): return typ return self.invalid_type(n) def numeric_type(self, value: object, n: AST) -> Type: # The node's field has the type complex, but complex isn't *really* # a parent of int and float, and this causes isinstance below # to think that the complex branch is always picked. Avoid # this by throwing away the type. if isinstance(value, int): numeric_value: int | None = value type_name = "builtins.int" else: # Other kinds of numbers (floats, complex) are not valid parameters for # RawExpressionType so we just pass in 'None' for now. We'll report the # appropriate error at a later stage. numeric_value = None type_name = f"builtins.{type(value).__name__}" return RawExpressionType( numeric_value, type_name, line=self.line, column=getattr(n, "col_offset", -1) ) def visit_Index(self, n: ast3.Index) -> Type: # cast for mypyc's benefit on Python 3.9 value = self.visit(cast(Any, n).value) assert isinstance(value, Type) return value def visit_Slice(self, n: ast3.Slice) -> Type: return self.invalid_type(n, note="did you mean to use ',' instead of ':' ?") # Subscript(expr value, expr slice, expr_context ctx) # Python 3.9 and later def visit_Subscript(self, n: ast3.Subscript) -> Type: empty_tuple_index = False if isinstance(n.slice, ast3.Tuple): params = self.translate_expr_list(n.slice.elts) if len(n.slice.elts) == 0: empty_tuple_index = True else: params = [self.visit(n.slice)] value = self.visit(n.value) if isinstance(value, UnboundType) and not value.args: result = UnboundType( value.name, params, line=self.line, column=value.column, empty_tuple_index=empty_tuple_index, ) result.end_column = getattr(n, "end_col_offset", None) result.end_line = getattr(n, "end_lineno", None) return result else: return self.invalid_type(n) def visit_Tuple(self, n: ast3.Tuple) -> Type: return TupleType( self.translate_expr_list(n.elts), _dummy_fallback, implicit=True, line=self.line, column=self.convert_column(n.col_offset), ) def visit_Dict(self, n: ast3.Dict) -> Type: if not n.keys: return self.invalid_type(n) items: dict[str, Type] = {} extra_items_from = [] for item_name, value in zip(n.keys, n.values): if not isinstance(item_name, ast3.Constant) or not isinstance(item_name.value, str): if item_name is None: extra_items_from.append(self.visit(value)) continue return self.invalid_type(n) items[item_name.value] = self.visit(value) result = TypedDictType(items, set(), set(), _dummy_fallback, n.lineno, n.col_offset) result.extra_items_from = extra_items_from return result # Attribute(expr value, identifier attr, expr_context ctx) def visit_Attribute(self, n: Attribute) -> Type: before_dot = self.visit(n.value) if isinstance(before_dot, UnboundType) and not before_dot.args: return UnboundType(f"{before_dot.name}.{n.attr}", line=self.line, column=n.col_offset) else: return self.invalid_type(n) # Used for Callable[[X *Ys, Z], R] etc. def visit_Starred(self, n: ast3.Starred) -> Type: return UnpackType(self.visit(n.value), from_star_syntax=True) # List(expr* elts, expr_context ctx) def visit_List(self, n: ast3.List) -> Type: assert isinstance(n.ctx, ast3.Load) result = self.translate_argument_list(n.elts) return result def stringify_name(n: AST) -> str | None: if isinstance(n, Name): return n.id elif isinstance(n, Attribute): sv = stringify_name(n.value) if sv is not None: return f"{sv}.{n.attr}" return None # Can't do it. class FindAttributeAssign(TraverserVisitor): """Check if an AST contains attribute assignments (e.g. self.x = 0).""" def __init__(self) -> None: self.lvalue = False self.found = False def visit_assignment_stmt(self, s: AssignmentStmt) -> None: self.lvalue = True for lv in s.lvalues: lv.accept(self) self.lvalue = False def visit_with_stmt(self, s: WithStmt) -> None: self.lvalue = True for lv in s.target: if lv is not None: lv.accept(self) self.lvalue = False s.body.accept(self) def visit_for_stmt(self, s: ForStmt) -> None: self.lvalue = True s.index.accept(self) self.lvalue = False s.body.accept(self) if s.else_body: s.else_body.accept(self) def visit_expression_stmt(self, s: ExpressionStmt) -> None: # No need to look inside these pass def visit_call_expr(self, e: CallExpr) -> None: # No need to look inside these pass def visit_index_expr(self, e: IndexExpr) -> None: # No need to look inside these pass def visit_member_expr(self, e: MemberExpr) -> None: if self.lvalue: self.found = True class FindYield(TraverserVisitor): """Check if an AST contains yields or yield froms.""" # codespell:ignore froms def __init__(self) -> None: self.found = False def visit_yield_expr(self, e: YieldExpr) -> None: self.found = True def visit_yield_from_expr(self, e: YieldFromExpr) -> None: self.found = True def is_possible_trivial_body(s: list[Statement]) -> bool: """Could the statements form a "trivial" function body, such as 'pass'? This mimics mypy.semanal.is_trivial_body, but this runs before semantic analysis so some checks must be conservative. """ l = len(s) if l == 0: return False i = 0 if isinstance(s[0], ExpressionStmt) and isinstance(s[0].expr, StrExpr): # Skip docstring i += 1 if i == l: return True if l > i + 1: return False stmt = s[i] return isinstance(stmt, (PassStmt, RaiseStmt)) or ( isinstance(stmt, ExpressionStmt) and isinstance(stmt.expr, EllipsisExpr) )