Merge branch 'master' into bugfix/gh-19686-enum-unanotated

Author: sterliakov

.github/workflows/docs.yml

@@ -12,6 +12,9 @@ on:
     # so it's important to do the docs build on all PRs touching mypy/errorcodes.py
     # in case somebody's adding a new error code without any docs
     - 'mypy/errorcodes.py'
+    # Part of the documentation is automatically generated from the options
+    # definitions in mypy/main.py
+    - 'mypy/main.py'
     - 'mypyc/doc/**'
     - '**/*.rst'
     - '**/*.md'

CHANGELOG.md

@@ -378,11 +378,9 @@ class TypeChecker(NodeVisitor[None], TypeCheckerSharedApi):
     inferred_attribute_types: dict[Var, Type] | None = None
     # Don't infer partial None types if we are processing assignment from Union
     no_partial_types: bool = False
-
-    # The set of all dependencies (suppressed or not) that this module accesses, either
-    # directly or indirectly.
+    # Extra module references not detected during semantic analysis (these are rare cases
+    # e.g. access to class-level import via instance).
     module_refs: set[str]
-
     # A map from variable nodes to a snapshot of the frame ids of the
     # frames that were active when the variable was declared. This can
     # be used to determine nearest common ancestor frame of a variable's
@@ -5682,8 +5680,8 @@ def visit_match_stmt(self, s: MatchStmt) -> None:
                 self.push_type_map(else_map, from_assignment=False)
                 unmatched_types = else_map
 
-            if unmatched_types is not None:
-                for typ in list(unmatched_types.values()):
+            if unmatched_types is not None and not self.current_node_deferred:
+                for typ in unmatched_types.values():
                     self.msg.match_statement_inexhaustive_match(typ, s)
 
             # This is needed due to a quirk in frame_context. Without it types will stay narrowed

mypy/build.py

@@ -198,7 +198,6 @@
 )
 from mypy.typestate import type_state
 from mypy.typevars import fill_typevars
-from mypy.util import split_module_names
 from mypy.visitor import ExpressionVisitor
 
 # Type of callback user for checking individual function arguments. See
@@ -248,36 +247,6 @@ def allow_fast_container_literal(t: Type) -> bool:
     )
 
 
-def extract_refexpr_names(expr: RefExpr, output: set[str]) -> None:
-    """Recursively extracts all module references from a reference expression.
-
-    Note that currently, the only two subclasses of RefExpr are NameExpr and
-    MemberExpr."""
-    while isinstance(expr.node, MypyFile) or expr.fullname:
-        if isinstance(expr.node, MypyFile) and expr.fullname:
-            # If it's None, something's wrong (perhaps due to an
-            # import cycle or a suppressed error).  For now we just
-            # skip it.
-            output.add(expr.fullname)
-
-        if isinstance(expr, NameExpr):
-            is_suppressed_import = isinstance(expr.node, Var) and expr.node.is_suppressed_import
-            if isinstance(expr.node, TypeInfo):
-                # Reference to a class or a nested class
-                output.update(split_module_names(expr.node.module_name))
-            elif "." in expr.fullname and not is_suppressed_import:
-                # Everything else (that is not a silenced import within a class)
-                output.add(expr.fullname.rsplit(".", 1)[0])
-            break
-        elif isinstance(expr, MemberExpr):
-            if isinstance(expr.expr, RefExpr):
-                expr = expr.expr
-            else:
-                break
-        else:
-            raise AssertionError(f"Unknown RefExpr subclass: {type(expr)}")
-
-
 class Finished(Exception):
     """Raised if we can terminate overload argument check early (no match)."""
 
@@ -370,7 +339,6 @@ def visit_name_expr(self, e: NameExpr) -> Type:
 
         It can be of any kind: local, member or global.
         """
-        extract_refexpr_names(e, self.chk.module_refs)
         result = self.analyze_ref_expr(e)
         narrowed = self.narrow_type_from_binder(e, result)
         self.chk.check_deprecated(e.node, e)
@@ -3344,7 +3312,6 @@ def check_union_call(
 
     def visit_member_expr(self, e: MemberExpr, is_lvalue: bool = False) -> Type:
         """Visit member expression (of form e.id)."""
-        extract_refexpr_names(e, self.chk.module_refs)
         result = self.analyze_ordinary_member_access(e, is_lvalue)
         narrowed = self.narrow_type_from_binder(e, result)
         self.chk.warn_deprecated(e.node, e)
@@ -6435,7 +6402,7 @@ def visit_type_var(self, t: TypeVarType) -> bool:
 
     def visit_param_spec(self, t: ParamSpecType) -> bool:
         default = [t.default] if t.has_default() else []
-        return self.query_types([t.upper_bound, *default])
+        return self.query_types([t.upper_bound, *default, t.prefix])
 
     def visit_type_var_tuple(self, t: TypeVarTupleType) -> bool:
         default = [t.default] if t.has_default() else []

mypy/checker.py

@@ -543,6 +543,8 @@ def analyze_member_var_access(
     if isinstance(v, FuncDef):
         assert False, "Did not expect a function"
     if isinstance(v, MypyFile):
+        # Special case: accessing module on instances is allowed, but will not
+        # be recorded by semantic analyzer.
         mx.chk.module_refs.add(v.fullname)
 
     if isinstance(vv, (TypeInfo, TypeAlias, MypyFile, TypeVarLikeExpr)):

mypy/checkexpr.py

@@ -21,6 +21,7 @@
     ArgKind,
     TypeInfo,
 )
+from mypy.type_visitor import ALL_STRATEGY, BoolTypeQuery
 from mypy.types import (
     TUPLE_LIKE_INSTANCE_NAMES,
     AnyType,
@@ -41,7 +42,6 @@
     TypeAliasType,
     TypedDictType,
     TypeOfAny,
-    TypeQuery,
     TypeType,
     TypeVarId,
     TypeVarLikeType,
@@ -670,9 +670,9 @@ def is_complete_type(typ: Type) -> bool:
     return typ.accept(CompleteTypeVisitor())
 
 
-class CompleteTypeVisitor(TypeQuery[bool]):
+class CompleteTypeVisitor(BoolTypeQuery):
     def __init__(self) -> None:
-        super().__init__(all)
+        super().__init__(ALL_STRATEGY)
 
     def visit_uninhabited_type(self, t: UninhabitedType) -> bool:
         return False

mypy/checkmember.py

@@ -222,6 +222,7 @@ def visit_type_var_tuple(self, t: TypeVarTupleType) -> Type:
         return t
 
     def visit_param_spec(self, t: ParamSpecType) -> Type:
+        # TODO: we should probably preserve prefix here.
         if self.erase_id is None or self.erase_id(t.id):
             return self.replacement
         return t

mypy/constraints.py

@@ -347,6 +347,7 @@ def visit_type_var(self, tvt: TypeVarType) -> None:
     def visit_param_spec(self, p: ParamSpecType) -> None:
         p.upper_bound.accept(self)
         p.default.accept(self)
+        p.prefix.accept(self)
 
     def visit_type_var_tuple(self, t: TypeVarTupleType) -> None:
         t.tuple_fallback.accept(self)
@@ -440,4 +441,4 @@ def missing_info(modules: dict[str, MypyFile]) -> TypeInfo:
 
 def missing_alias() -> TypeAlias:
     suggestion = _SUGGESTION.format("alias")
-    return TypeAlias(AnyType(TypeOfAny.special_form), suggestion, line=-1, column=-1)
+    return TypeAlias(AnyType(TypeOfAny.special_form), suggestion, "<missing>", line=-1, column=-1)

mypy/erasetype.py

@@ -4,17 +4,6 @@
 
 import mypy.types as types
 from mypy.types import TypeVisitor
-from mypy.util import split_module_names
-
-
-def extract_module_names(type_name: str | None) -> list[str]:
-    """Returns the module names of a fully qualified type name."""
-    if type_name is not None:
-        # Discard the first one, which is just the qualified name of the type
-        possible_module_names = split_module_names(type_name)
-        return possible_module_names[1:]
-    else:
-        return []
 
 
 class TypeIndirectionVisitor(TypeVisitor[None]):
@@ -23,50 +12,57 @@ class TypeIndirectionVisitor(TypeVisitor[None]):
     def __init__(self) -> None:
         # Module references are collected here
         self.modules: set[str] = set()
-        # User to avoid infinite recursion with recursive type aliases
-        self.seen_aliases: set[types.TypeAliasType] = set()
-        # Used to avoid redundant work
-        self.seen_fullnames: set[str] = set()
+        # User to avoid infinite recursion with recursive types
+        self.seen_types: set[types.TypeAliasType | types.Instance] = set()
 
     def find_modules(self, typs: Iterable[types.Type]) -> set[str]:
         self.modules = set()
-        self.seen_fullnames = set()
-        self.seen_aliases = set()
+        self.seen_types = set()
         for typ in typs:
             self._visit(typ)
         return self.modules
 
     def _visit(self, typ: types.Type) -> None:
-        if isinstance(typ, types.TypeAliasType):
-            # Avoid infinite recursion for recursive type aliases.
-            if typ not in self.seen_aliases:
-                self.seen_aliases.add(typ)
+        # Note: instances are needed for `class str(Sequence[str]): ...`
+        if (
+            isinstance(typ, types.TypeAliasType)
+            or isinstance(typ, types.ProperType)
+            and isinstance(typ, types.Instance)
+        ):
+            # Avoid infinite recursion for recursive types.
+            if typ in self.seen_types:
+                return
+            self.seen_types.add(typ)
         typ.accept(self)
 
     def _visit_type_tuple(self, typs: tuple[types.Type, ...]) -> None:
         # Micro-optimization: Specialized version of _visit for lists
         for typ in typs:
-            if isinstance(typ, types.TypeAliasType):
-                # Avoid infinite recursion for recursive type aliases.
-                if typ in self.seen_aliases:
+            if (
+                isinstance(typ, types.TypeAliasType)
+                or isinstance(typ, types.ProperType)
+                and isinstance(typ, types.Instance)
+            ):
+                # Avoid infinite recursion for recursive types.
+                if typ in self.seen_types:
                     continue
-                self.seen_aliases.add(typ)
+                self.seen_types.add(typ)
             typ.accept(self)
 
     def _visit_type_list(self, typs: list[types.Type]) -> None:
         # Micro-optimization: Specialized version of _visit for tuples
         for typ in typs:
-            if isinstance(typ, types.TypeAliasType):
-                # Avoid infinite recursion for recursive type aliases.
-                if typ in self.seen_aliases:
+            if (
+                isinstance(typ, types.TypeAliasType)
+                or isinstance(typ, types.ProperType)
+                and isinstance(typ, types.Instance)
+            ):
+                # Avoid infinite recursion for recursive types.
+                if typ in self.seen_types:
                     continue
-                self.seen_aliases.add(typ)
+                self.seen_types.add(typ)
             typ.accept(self)
 
-    def _visit_module_name(self, module_name: str) -> None:
-        if module_name not in self.modules:
-            self.modules.update(split_module_names(module_name))
-
     def visit_unbound_type(self, t: types.UnboundType) -> None:
         self._visit_type_tuple(t.args)
 
@@ -93,6 +89,7 @@ def visit_type_var(self, t: types.TypeVarType) -> None:
     def visit_param_spec(self, t: types.ParamSpecType) -> None:
         self._visit(t.upper_bound)
         self._visit(t.default)
+        self._visit(t.prefix)
 
     def visit_type_var_tuple(self, t: types.TypeVarTupleType) -> None:
         self._visit(t.upper_bound)
@@ -105,27 +102,36 @@ def visit_parameters(self, t: types.Parameters) -> None:
         self._visit_type_list(t.arg_types)
 
     def visit_instance(self, t: types.Instance) -> None:
+        # Instance is named, record its definition and continue digging into
+        # components that constitute semantic meaning of this type: bases, metaclass,
+        # tuple type, and typeddict type.
+        # Note: we cannot simply record the MRO, in case an intermediate base contains
+        # a reference to type alias, this affects meaning of map_instance_to_supertype(),
+        # see e.g. testDoubleReexportGenericUpdated.
         self._visit_type_tuple(t.args)
         if t.type:
-            # Uses of a class depend on everything in the MRO,
-            # as changes to classes in the MRO can add types to methods,
-            # change property types, change the MRO itself, etc.
+            # Important optimization: instead of simply recording the definition and
+            # recursing into bases, record the MRO and only traverse generic bases.
             for s in t.type.mro:
-                self._visit_module_name(s.module_name)
-            if t.type.metaclass_type is not None:
-                self._visit_module_name(t.type.metaclass_type.type.module_name)
+                self.modules.add(s.module_name)
+                for base in s.bases:
+                    if base.args:
+                        self._visit_type_tuple(base.args)
+            if t.type.metaclass_type:
+                self._visit(t.type.metaclass_type)
+            if t.type.typeddict_type:
+                self._visit(t.type.typeddict_type)
+            if t.type.tuple_type:
+                self._visit(t.type.tuple_type)
 
     def visit_callable_type(self, t: types.CallableType) -> None:
         self._visit_type_list(t.arg_types)
         self._visit(t.ret_type)
-        if t.definition is not None:
-            fullname = t.definition.fullname
-            if fullname not in self.seen_fullnames:
-                self.modules.update(extract_module_names(t.definition.fullname))
-                self.seen_fullnames.add(fullname)
+        self._visit_type_tuple(t.variables)
 
     def visit_overloaded(self, t: types.Overloaded) -> None:
-        self._visit_type_list(list(t.items))
+        for item in t.items:
+            self._visit(item)
         self._visit(t.fallback)
 
     def visit_tuple_type(self, t: types.TupleType) -> None:
@@ -149,4 +155,9 @@ def visit_type_type(self, t: types.TypeType) -> None:
         self._visit(t.item)
 
     def visit_type_alias_type(self, t: types.TypeAliasType) -> None:
-        self._visit(types.get_proper_type(t))
+        # Type alias is named, record its definition and continue digging into
+        # components that constitute semantic meaning of this type: target and args.
+        if t.alias:
+            self.modules.add(t.alias.module)
+            self._visit(t.alias.target)
+        self._visit_type_list(t.args)