Merge branch 'python:master' into missing-args-callable

Author: lesliehuh

docs/source/command_line.rst

@@ -749,8 +749,19 @@ of the above sections.
 
 .. option:: --strict
 
-    This flag mode enables all optional error checking flags.  You can see the
-    list of flags enabled by strict mode in the full :option:`mypy --help` output.
+    This flag mode enables a defined subset of optional error-checking flags.
+    This subset primarily includes checks for inadvertent type unsoundness (i.e
+    strict will catch type errors as long as intentional methods like type ignore
+    or casting were not used.)
+
+    Note: the :option:`--warn-unreachable` flag
+    is not automatically enabled by the strict flag.
+
+    The strict flag does not take precedence over other strict-related flags.
+    Directly specifying a flag of alternate behavior will override the
+    behavior of strict, regardless of the order in which they are passed.
+    You can see the list of flags enabled by strict mode in the full
+    :option:`mypy --help` output.
 
     Note: the exact list of flags enabled by running :option:`--strict` may change
     over time.

mypy/checkexpr.py

@@ -4732,8 +4732,8 @@ def visit_cast_expr(self, expr: CastExpr) -> Type:
         options = self.chk.options
         if (
             options.warn_redundant_casts
-            and not isinstance(get_proper_type(target_type), AnyType)
-            and source_type == target_type
+            and not is_same_type(target_type, AnyType(TypeOfAny.special_form))
+            and is_same_type(source_type, target_type)
         ):
             self.msg.redundant_cast(target_type, expr)
         if options.disallow_any_unimported and has_any_from_unimported_type(target_type):

mypy/dmypy/client.py

@@ -20,6 +20,7 @@
 from mypy.dmypy_os import alive, kill
 from mypy.dmypy_util import DEFAULT_STATUS_FILE, receive, send
 from mypy.ipc import IPCClient, IPCException
+from mypy.main import RECURSION_LIMIT
 from mypy.util import check_python_version, get_terminal_width, should_force_color
 from mypy.version import __version__
 
@@ -268,6 +269,10 @@ class BadStatus(Exception):
 def main(argv: list[str]) -> None:
     """The code is top-down."""
     check_python_version("dmypy")
+
+    # set recursion limit consistent with mypy/main.py
+    sys.setrecursionlimit(RECURSION_LIMIT)
+
     args = parser.parse_args(argv)
     if not args.action:
         parser.print_usage()

mypy/fastparse.py

@@ -239,6 +239,29 @@ def parse(
             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"):
@@ -381,7 +404,7 @@ def __init__(
     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 = True) -> None:
+    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(
@@ -406,6 +429,7 @@ def visit(self, node: AST | None) -> Any:
             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:
@@ -921,7 +945,12 @@ def do_func_def(
                 ):
                     if n.returns:
                         # PEP 484 disallows both type annotations and type comments
-                        self.fail(message_registry.DUPLICATE_TYPE_SIGNATURES, lineno, n.col_offset)
+                        self.fail(
+                            message_registry.DUPLICATE_TYPE_SIGNATURES,
+                            lineno,
+                            n.col_offset,
+                            blocker=False,
+                        )
                     arg_types = [
                         (
                             a.type_annotation
@@ -933,7 +962,12 @@ def do_func_def(
                 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)
+                        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)
@@ -948,7 +982,7 @@ def do_func_def(
             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)
+                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
@@ -970,7 +1004,12 @@ def do_func_def(
         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)
+                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,
@@ -1097,7 +1136,12 @@ def make_argument(
             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)
+                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)
@@ -1118,7 +1162,7 @@ def make_argument(
         return argument
 
     def fail_arg(self, msg: str, arg: ast3.arg) -> None:
-        self.fail(ErrorMessage(msg), arg.lineno, arg.col_offset)
+        self.fail(ErrorMessage(msg), arg.lineno, arg.col_offset, blocker=True)
 
     # ClassDef(identifier name,
     #  expr* bases,
@@ -1164,18 +1208,21 @@ def validate_type_param(self, type_param: ast_TypeVar) -> None:
                 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]:
@@ -1790,11 +1837,26 @@ def validate_type_alias(self, n: ast_TypeAlias) -> None:
         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)
+            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)
+            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)
+            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:

mypy/main.py

@@ -42,6 +42,7 @@
 
 orig_stat: Final = os.stat
 MEM_PROFILE: Final = False  # If True, dump memory profile
+RECURSION_LIMIT: Final = 2**14
 
 
 def stat_proxy(path: str) -> os.stat_result:
@@ -76,7 +77,7 @@ def main(
     util.check_python_version("mypy")
     t0 = time.time()
     # To log stat() calls: os.stat = stat_proxy
-    sys.setrecursionlimit(2**14)
+    sys.setrecursionlimit(RECURSION_LIMIT)
     if args is None:
         args = sys.argv[1:]
 
@@ -1127,6 +1128,11 @@ def add_invertible_flag(
     report_group.add_argument(
         "-a", dest="mypyc_annotation_file", type=str, default=None, help=argparse.SUPPRESS
     )
+    # Hidden mypyc feature: do not write any C files (keep existing ones and assume they exist).
+    # This can be useful when debugging mypyc bugs.
+    report_group.add_argument(
+        "--skip-c-gen", dest="mypyc_skip_c_generation", action="store_true", help=argparse.SUPPRESS
+    )
 
     other_group = parser.add_argument_group(title="Miscellaneous")
     other_group.add_argument("--quickstart-file", help=argparse.SUPPRESS)

mypy/options.py

@@ -408,6 +408,9 @@ def __init__(self) -> None:
 
         # Output html file for mypyc -a
         self.mypyc_annotation_file: str | None = None
+        # Skip writing C output files, but perform all other steps of a build (allows
+        # preserving manual tweaks to generated C file)
+        self.mypyc_skip_c_generation = False
 
     def use_lowercase_names(self) -> bool:
         if self.python_version >= (3, 9):

mypy/plugins/dataclasses.py

@@ -359,12 +359,12 @@ def transform(self) -> bool:
 
         if decorator_arguments["frozen"]:
             if any(not parent["frozen"] for parent in parent_decorator_arguments):
-                self._api.fail("Cannot inherit frozen dataclass from a non-frozen one", info)
+                self._api.fail("Frozen dataclass cannot inherit from a non-frozen dataclass", info)
             self._propertize_callables(attributes, settable=False)
             self._freeze(attributes)
         else:
             if any(parent["frozen"] for parent in parent_decorator_arguments):
-                self._api.fail("Cannot inherit non-frozen dataclass from a frozen one", info)
+                self._api.fail("Non-frozen dataclass cannot inherit from a frozen dataclass", info)
             self._propertize_callables(attributes)
 
         if decorator_arguments["slots"]:

mypy/semanal.py

@@ -5591,7 +5591,7 @@ def visit_type_alias_stmt(self, s: TypeAliasStmt) -> None:
                 self.msg.unimported_type_becomes_any("Type alias target", res, s)
                 res = make_any_non_unimported(res)
             eager = self.is_func_scope()
-            if isinstance(res, ProperType) and isinstance(res, Instance) and not res.args:
+            if isinstance(res, ProperType) and isinstance(res, Instance):
                 fix_instance(res, self.fail, self.note, disallow_any=False, options=self.options)
             alias_node = TypeAlias(
                 res,

mypy/subtypes.py

@@ -1091,6 +1091,11 @@ def visit_type_type(self, left: TypeType) -> bool:
         right = self.right
         if isinstance(right, TypeType):
             return self._is_subtype(left.item, right.item)
+        if isinstance(right, Overloaded) and right.is_type_obj():
+            # Same as in other direction: if it's a constructor callable, all
+            # items should belong to the same class' constructor, so it's enough
+            # to check one of them.
+            return self._is_subtype(left, right.items[0])
         if isinstance(right, CallableType):
             if self.proper_subtype and not right.is_type_obj():
                 # We can't accept `Type[X]` as a *proper* subtype of Callable[P, X]

mypyc/analysis/dataflow.py

@@ -17,6 +17,7 @@
     Cast,
     ComparisonOp,
     ControlOp,
+    DecRef,
     Extend,
     Float,
     FloatComparisonOp,
@@ -25,6 +26,7 @@
     GetAttr,
     GetElementPtr,
     Goto,
+    IncRef,
     InitStatic,
     Integer,
     IntOp,
@@ -77,12 +79,11 @@ def __str__(self) -> str:
         return f"exits: {exits}\nsucc: {self.succ}\npred: {self.pred}"
 
 
-def get_cfg(blocks: list[BasicBlock]) -> CFG:
+def get_cfg(blocks: list[BasicBlock], *, use_yields: bool = False) -> CFG:
     """Calculate basic block control-flow graph.
 
-    The result is a dictionary like this:
-
-         basic block index -> (successors blocks, predecesssor blocks)
+    If use_yields is set, then we treat returns inserted by yields as gotos
+    instead of exits.
     """
     succ_map = {}
     pred_map: dict[BasicBlock, list[BasicBlock]] = {}
@@ -92,7 +93,10 @@ def get_cfg(blocks: list[BasicBlock]) -> CFG:
             isinstance(op, ControlOp) for op in block.ops[:-1]
         ), "Control-flow ops must be at the end of blocks"
 
-        succ = list(block.terminator.targets())
+        if use_yields and isinstance(block.terminator, Return) and block.terminator.yield_target:
+            succ = [block.terminator.yield_target]
+        else:
+            succ = list(block.terminator.targets())
         if not succ:
             exits.add(block)
 
@@ -474,6 +478,12 @@ def visit_assign_multi(self, op: AssignMulti) -> GenAndKill[Value]:
     def visit_set_mem(self, op: SetMem) -> GenAndKill[Value]:
         return non_trivial_sources(op), set()
 
+    def visit_inc_ref(self, op: IncRef) -> GenAndKill[Value]:
+        return set(), set()
+
+    def visit_dec_ref(self, op: DecRef) -> GenAndKill[Value]:
+        return set(), set()
+
 
 def analyze_live_regs(blocks: list[BasicBlock], cfg: CFG) -> AnalysisResult[Value]:
     """Calculate live registers at each CFG location.