Merge branch 'master' into feature/gh-19392-decorator-selftypes

Author: sterliakov

docs/source/conf.py

@@ -278,9 +278,9 @@
 intersphinx_mapping = {
     "python": ("https://docs.python.org/3", None),
     "attrs": ("https://www.attrs.org/en/stable/", None),
-    "cython": ("https://docs.cython.org/en/latest", None),
+    "cython": ("https://cython.readthedocs.io/en/stable", None),
     "monkeytype": ("https://monkeytype.readthedocs.io/en/latest", None),
-    "setuptools": ("https://setuptools.readthedocs.io/en/latest", None),
+    "setuptools": ("https://setuptools.pypa.io/en/latest", None),
 }
 
 

mypy/build.py

@@ -194,7 +194,7 @@ def default_flush_errors(
         result.errors = messages
         return result
     except CompileError as e:
-        # CompileErrors raised from an errors object carry all of the
+        # CompileErrors raised from an errors object carry all the
         # messages that have not been reported out by error streaming.
         # Patch it up to contain either none or all none of the messages,
         # depending on whether we are flushing errors.
@@ -802,11 +802,11 @@ def correct_rel_imp(imp: ImportFrom | ImportAll) -> str:
                             res.append((pri, sub_id, imp.line))
                         else:
                             all_are_submodules = False
-                    # Add cur_id as a dependency, even if all of the
+                    # Add cur_id as a dependency, even if all the
                     # imports are submodules. Processing import from will try
                     # to look through cur_id, so we should depend on it.
-                    # As a workaround for for some bugs in cycle handling (#4498),
-                    # if all of the imports are submodules, do the import at a lower
+                    # As a workaround for some bugs in cycle handling (#4498),
+                    # if all the imports are submodules, do the import at a lower
                     # priority.
                     pri = import_priority(imp, PRI_HIGH if not all_are_submodules else PRI_LOW)
                     res.append((pri, cur_id, imp.line))
@@ -929,7 +929,7 @@ def write_deps_cache(
 ) -> None:
     """Write cache files for fine-grained dependencies.
 
-    Serialize fine-grained dependencies map for fine grained mode.
+    Serialize fine-grained dependencies map for fine-grained mode.
 
     Dependencies on some module 'm' is stored in the dependency cache
     file m.deps.json.  This entails some spooky action at a distance:
@@ -943,7 +943,7 @@ def write_deps_cache(
     fine-grained dependencies in a global cache file:
      * We take a snapshot of current sources to later check consistency
        between the fine-grained dependency cache and module cache metadata
-     * We store the mtime of all of the dependency files to verify they
+     * We store the mtime of all the dependency files to verify they
        haven't changed
     """
     metastore = manager.metastore
@@ -1111,7 +1111,7 @@ def read_deps_cache(manager: BuildManager, graph: Graph) -> dict[str, FgDepMeta]
     if deps_meta is None:
         return None
     meta_snapshot = deps_meta["snapshot"]
-    # Take a snapshot of the source hashes from all of the metas we found.
+    # Take a snapshot of the source hashes from all the metas we found.
     # (Including the ones we rejected because they were out of date.)
     # We use this to verify that they match up with the proto_deps.
     current_meta_snapshot = {

mypy/checker.py

@@ -397,6 +397,7 @@ def __init__(
         self.is_stub = tree.is_stub
         self.is_typeshed_stub = tree.is_typeshed_file(options)
         self.inferred_attribute_types = None
+        self.allow_constructor_cache = True
 
         # If True, process function definitions. If False, don't. This is used
         # for processing module top levels in fine-grained incremental mode.
@@ -500,12 +501,16 @@ def check_first_pass(self) -> None:
                         )
 
     def check_second_pass(
-        self, todo: Sequence[DeferredNode | FineGrainedDeferredNode] | None = None
+        self,
+        todo: Sequence[DeferredNode | FineGrainedDeferredNode] | None = None,
+        *,
+        allow_constructor_cache: bool = True,
     ) -> bool:
         """Run second or following pass of type checking.
 
         This goes through deferred nodes, returning True if there were any.
         """
+        self.allow_constructor_cache = allow_constructor_cache
         self.recurse_into_functions = True
         with state.strict_optional_set(self.options.strict_optional), checker_state.set(self):
             if not todo and not self.deferred_nodes:
@@ -5602,6 +5607,8 @@ def infer_variable_types_from_type_maps(
                 previous_type, _, _ = self.check_lvalue(expr)
                 if previous_type is not None:
                     already_exists = True
+                    if isinstance(expr.node, Var) and expr.node.is_final:
+                        self.msg.cant_assign_to_final(expr.name, False, expr)
                     if self.check_subtype(
                         typ,
                         previous_type,

mypy/checker_shared.py

@@ -137,6 +137,7 @@ class TypeCheckerSharedApi(CheckerPluginInterface):
     module_refs: set[str]
     scope: CheckerScope
     checking_missing_await: bool
+    allow_constructor_cache: bool
 
     @property
     @abstractmethod

mypy/checkexpr.py

@@ -3468,7 +3468,7 @@ def visit_op_expr(self, e: OpExpr) -> Type:
             # It's actually a type expression X | Y.
             return self.accept(e.analyzed)
         if e.op == "and" or e.op == "or":
-            return self.check_boolean_op(e, e)
+            return self.check_boolean_op(e)
         if e.op == "*" and isinstance(e.left, ListExpr):
             # Expressions of form [...] * e get special type inference.
             return self.check_list_multiply(e)
@@ -4255,20 +4255,18 @@ def check_op(
                 context=context,
             )
 
-    def check_boolean_op(self, e: OpExpr, context: Context) -> Type:
+    def check_boolean_op(self, e: OpExpr) -> Type:
         """Type check a boolean operation ('and' or 'or')."""
 
         # A boolean operation can evaluate to either of the operands.
 
-        # We use the current type context to guide the type inference of of
+        # We use the current type context to guide the type inference of
         # the left operand. We also use the left operand type to guide the type
         # inference of the right operand so that expressions such as
         # '[1] or []' are inferred correctly.
         ctx = self.type_context[-1]
         left_type = self.accept(e.left, ctx)
-        expanded_left_type = try_expanding_sum_type_to_union(
-            self.accept(e.left, ctx), "builtins.bool"
-        )
+        expanded_left_type = try_expanding_sum_type_to_union(left_type, "builtins.bool")
 
         assert e.op in ("and", "or")  # Checked by visit_op_expr
 

mypy/nodes.py

@@ -3022,6 +3022,7 @@ class is generic then it will be a type constructor of higher kind.
         "dataclass_transform_spec",
         "is_type_check_only",
         "deprecated",
+        "type_object_type",
     )
 
     _fullname: str  # Fully qualified name
@@ -3178,6 +3179,10 @@ class is generic then it will be a type constructor of higher kind.
     # The type's deprecation message (in case it is deprecated)
     deprecated: str | None
 
+    # Cached value of class constructor type, i.e. the type of class object when it
+    # appears in runtime context.
+    type_object_type: mypy.types.FunctionLike | None
+
     FLAGS: Final = [
         "is_abstract",
         "is_enum",
@@ -3236,6 +3241,7 @@ def __init__(self, names: SymbolTable, defn: ClassDef, module_name: str) -> None
         self.dataclass_transform_spec = None
         self.is_type_check_only = False
         self.deprecated = None
+        self.type_object_type = None
 
     def add_type_vars(self) -> None:
         self.has_type_var_tuple_type = False

mypy/semanal_infer.py

@@ -31,6 +31,7 @@ def infer_decorator_signature_if_simple(
     """
     if dec.var.is_property:
         # Decorators are expected to have a callable type (it's a little odd).
+        # TODO: this may result in wrong type if @property is applied to decorated method.
         if dec.func.type is None:
             dec.var.type = CallableType(
                 [AnyType(TypeOfAny.special_form)],
@@ -47,6 +48,8 @@ def infer_decorator_signature_if_simple(
     for expr in dec.decorators:
         preserve_type = False
         if isinstance(expr, RefExpr) and isinstance(expr.node, FuncDef):
+            if expr.fullname == "typing.no_type_check":
+                return
             if expr.node.type and is_identity_signature(expr.node.type):
                 preserve_type = True
         if not preserve_type:

mypy/server/update.py

@@ -1025,10 +1025,12 @@ def key(node: FineGrainedDeferredNode) -> int:
     # We seem to need additional passes in fine-grained incremental mode.
     checker.pass_num = 0
     checker.last_pass = 3
-    more = checker.check_second_pass(nodes)
+    # It is tricky to reliably invalidate constructor cache in fine-grained increments.
+    # See PR 19514 description for details.
+    more = checker.check_second_pass(nodes, allow_constructor_cache=False)
     while more:
         more = False
-        if graph[module_id].type_checker().check_second_pass():
+        if graph[module_id].type_checker().check_second_pass(allow_constructor_cache=False):
             more = True
 
     if manager.options.export_types:

mypy/typeops.py

@@ -11,6 +11,7 @@
 from collections.abc import Iterable, Sequence
 from typing import Any, Callable, TypeVar, cast
 
+from mypy.checker_state import checker_state
 from mypy.copytype import copy_type
 from mypy.expandtype import expand_type, expand_type_by_instance
 from mypy.maptype import map_instance_to_supertype
@@ -145,6 +146,15 @@ def type_object_type(info: TypeInfo, named_type: Callable[[str], Instance]) -> P
     where ... are argument types for the __init__/__new__ method (without the self
     argument). Also, the fallback type will be 'type' instead of 'function'.
     """
+    allow_cache = (
+        checker_state.type_checker is not None
+        and checker_state.type_checker.allow_constructor_cache
+    )
+
+    if info.type_object_type is not None:
+        if allow_cache:
+            return info.type_object_type
+        info.type_object_type = None
 
     # We take the type from whichever of __init__ and __new__ is first
     # in the MRO, preferring __init__ if there is a tie.
@@ -167,7 +177,15 @@ def type_object_type(info: TypeInfo, named_type: Callable[[str], Instance]) -> P
     init_index = info.mro.index(init_method.node.info)
     new_index = info.mro.index(new_method.node.info)
 
-    fallback = info.metaclass_type or named_type("builtins.type")
+    if info.metaclass_type is not None:
+        fallback = info.metaclass_type
+    elif checker_state.type_checker:
+        # Prefer direct call when it is available. It is faster, and,
+        # unfortunately, some callers provide bogus callback.
+        fallback = checker_state.type_checker.named_type("builtins.type")
+    else:
+        fallback = named_type("builtins.type")
+
     if init_index < new_index:
         method: FuncBase | Decorator = init_method.node
         is_new = False
@@ -189,7 +207,10 @@ def type_object_type(info: TypeInfo, named_type: Callable[[str], Instance]) -> P
                     is_bound=True,
                     fallback=named_type("builtins.function"),
                 )
-                return class_callable(sig, info, fallback, None, is_new=False)
+                result: FunctionLike = class_callable(sig, info, fallback, None, is_new=False)
+                if allow_cache:
+                    info.type_object_type = result
+                return result
 
         # Otherwise prefer __init__ in a tie. It isn't clear that this
         # is the right thing, but __new__ caused problems with
@@ -199,12 +220,19 @@ def type_object_type(info: TypeInfo, named_type: Callable[[str], Instance]) -> P
     # Construct callable type based on signature of __init__. Adjust
     # return type and insert type arguments.
     if isinstance(method, FuncBase):
+        if isinstance(method, OverloadedFuncDef) and not method.type:
+            # Do not cache if the type is not ready. Same logic for decorators is
+            # achieved in early return above because is_valid_constructor() is False.
+            allow_cache = False
         t = function_type(method, fallback)
     else:
         assert isinstance(method.type, ProperType)
         assert isinstance(method.type, FunctionLike)  # is_valid_constructor() ensures this
         t = method.type
-    return type_object_type_from_function(t, info, method.info, fallback, is_new)
+    result = type_object_type_from_function(t, info, method.info, fallback, is_new)
+    if allow_cache:
+        info.type_object_type = result
+    return result
 
 
 def is_valid_constructor(n: SymbolNode | None) -> bool:
@@ -865,8 +893,8 @@ def function_type(func: FuncBase, fallback: Instance) -> FunctionLike:
         if isinstance(func, FuncItem):
             return callable_type(func, fallback)
         else:
-            # Broken overloads can have self.type set to None.
-            # TODO: should we instead always set the type in semantic analyzer?
+            # Either a broken overload, or decorated overload type is not ready.
+            # TODO: make sure the caller defers if possible.
             assert isinstance(func, OverloadedFuncDef)
             any_type = AnyType(TypeOfAny.from_error)
             dummy = CallableType(
@@ -1254,6 +1282,8 @@ def get_protocol_member(
     if member == "__call__" and class_obj:
         # Special case: class objects always have __call__ that is just the constructor.
 
+        # TODO: this is wrong, it creates callables that are not recognized as type objects.
+        # Long-term, we should probably get rid of this callback argument altogether.
         def named_type(fullname: str) -> Instance:
             return Instance(left.type.mro[-1], [])
 

mypyc/build.py

@@ -270,12 +270,12 @@ def build_using_shared_lib(
 ) -> list[Extension]:
     """Produce the list of extension modules when a shared library is needed.
 
-    This creates one shared library extension module that all of the
-    others import and then one shim extension module for each
-    module in the build, that simply calls an initialization function
+    This creates one shared library extension module that all the
+    others import, and one shim extension module for each
+    module in the build. Each shim simply calls an initialization function
     in the shared library.
 
-    The shared library (which lib_name is the name of) is a python
+    The shared library (which lib_name is the name of) is a Python
     extension module that exports the real initialization functions in
     Capsules stored in module attributes.
     """
@@ -511,7 +511,7 @@ def mypycify(
         separate: Should compiled modules be placed in separate extension modules.
                   If False, all modules are placed in a single shared library.
                   If True, every module is placed in its own library.
-                  Otherwise separate should be a list of
+                  Otherwise, separate should be a list of
                   (file name list, optional shared library name) pairs specifying
                   groups of files that should be placed in the same shared library
                   (while all other modules will be placed in its own library).