Merge remote-tracking branch 'upstream/master' into bugfix/st-match-case-crash-name-reuse

Author: sterliakov

CHANGELOG.md

@@ -4,7 +4,10 @@
 
 ### Performance improvements
 
-TODO
+Mypy may be 5-30% faster. This improvement comes largely from tuning the performance of the
+garbage collector.
+
+Contributed by Jukka Lehtosalo (PR [18306](https://github.com/python/mypy/pull/18306)).
 
 ### Drop Support for Python 3.8
 
@@ -33,13 +36,14 @@ Use this flag to disable this behavior. `--strict-bytes` will be enabled by defa
 Contributed by Ali Hamdan (PR [18137](https://github.com/python/mypy/pull/18263/)) and
 Shantanu Jain (PR [13952](https://github.com/python/mypy/pull/13952)).
 
-### Improvements to partial type handling in loops
+### Improvements to reachability analysis and partial type handling in loops
 
 This change results in mypy better modelling control flow within loops and hence detecting several
 issues it previously did not detect. In some cases, this change may require use of an additional
 explicit annotation of a variable.
 
-Contributed by Christoph Tyralla (PR [18180](https://github.com/python/mypy/pull/18180)).
+Contributed by Christoph Tyralla (PR [18180](https://github.com/python/mypy/pull/18180),
+[PR](https://github.com/python/mypy/pull/18433)).
 
 (Speaking of partial types, another reminder that mypy plans on enabling `--local-partial-types`
 by default in **mypy 2.0**).

docs/source/common_issues.rst

@@ -427,8 +427,8 @@ More specifically, mypy will understand the use of :py:data:`sys.version_info` a
    import sys
 
    # Distinguishing between different versions of Python:
-   if sys.version_info >= (3, 8):
-       # Python 3.8+ specific definitions and imports
+   if sys.version_info >= (3, 13):
+       # Python 3.13+ specific definitions and imports
    else:
        # Other definitions and imports
 

docs/source/runtime_troubles.rst

@@ -335,29 +335,25 @@ Using new additions to the typing module
 ----------------------------------------
 
 You may find yourself wanting to use features added to the :py:mod:`typing`
-module in earlier versions of Python than the addition, for example, using any
-of ``Literal``, ``Protocol``, ``TypedDict`` with Python 3.6.
+module in earlier versions of Python than the addition.
 
 The easiest way to do this is to install and use the ``typing_extensions``
 package from PyPI for the relevant imports, for example:
 
 .. code-block:: python
 
-   from typing_extensions import Literal
-   x: Literal["open", "close"]
+   from typing_extensions import TypeIs
 
 If you don't want to rely on ``typing_extensions`` being installed on newer
 Pythons, you could alternatively use:
 
 .. code-block:: python
 
    import sys
-   if sys.version_info >= (3, 8):
-       from typing import Literal
+   if sys.version_info >= (3, 13):
+       from typing import TypeIs
    else:
-       from typing_extensions import Literal
-
-   x: Literal["open", "close"]
+       from typing_extensions import TypeIs
 
 This plays nicely well with following :pep:`508` dependency specification:
-``typing_extensions; python_version<"3.8"``
+``typing_extensions; python_version<"3.13"``

mypy/checker.py

@@ -584,24 +584,43 @@ def accept_loop(
         *,
         exit_condition: Expression | None = None,
     ) -> None:
-        """Repeatedly type check a loop body until the frame doesn't change.
-        If exit_condition is set, assume it must be False on exit from the loop.
+        """Repeatedly type check a loop body until the frame doesn't change."""
 
-        Then check the else_body.
-        """
-        # The outer frame accumulates the results of all iterations
+        # The outer frame accumulates the results of all iterations:
         with self.binder.frame_context(can_skip=False, conditional_frame=True):
+
+            # Check for potential decreases in the number of partial types so as not to stop the
+            # iteration too early:
             partials_old = sum(len(pts.map) for pts in self.partial_types)
+
+            # Disable error types that we cannot safely identify in intermediate iteration steps:
+            warn_unreachable = self.options.warn_unreachable
+            warn_redundant = codes.REDUNDANT_EXPR in self.options.enabled_error_codes
+            self.options.warn_unreachable = False
+            self.options.enabled_error_codes.discard(codes.REDUNDANT_EXPR)
+
             while True:
                 with self.binder.frame_context(can_skip=True, break_frame=2, continue_frame=1):
                     self.accept(body)
                 partials_new = sum(len(pts.map) for pts in self.partial_types)
                 if (partials_new == partials_old) and not self.binder.last_pop_changed:
                     break
                 partials_old = partials_new
+
+            # If necessary, reset the modified options and make up for the postponed error checks:
+            self.options.warn_unreachable = warn_unreachable
+            if warn_redundant:
+                self.options.enabled_error_codes.add(codes.REDUNDANT_EXPR)
+            if warn_unreachable or warn_redundant:
+                with self.binder.frame_context(can_skip=True, break_frame=2, continue_frame=1):
+                    self.accept(body)
+
+            # If exit_condition is set, assume it must be False on exit from the loop:
             if exit_condition:
                 _, else_map = self.find_isinstance_check(exit_condition)
                 self.push_type_map(else_map)
+
+            # Check the else body:
             if else_body:
                 self.accept(else_body)
 

mypy/checkpattern.py

@@ -713,6 +713,8 @@ def should_self_match(self, typ: Type) -> bool:
         return False
 
     def can_match_sequence(self, typ: ProperType) -> bool:
+        if isinstance(typ, AnyType):
+            return True
         if isinstance(typ, UnionType):
             return any(self.can_match_sequence(get_proper_type(item)) for item in typ.items)
         for other in self.non_sequence_match_types:
@@ -763,6 +765,8 @@ def construct_sequence_child(self, outer_type: Type, inner_type: Type) -> Type:
         or class T(Sequence[Tuple[T, T]]), there is no way any of those can map to Sequence[str].
         """
         proper_type = get_proper_type(outer_type)
+        if isinstance(proper_type, AnyType):
+            return outer_type
         if isinstance(proper_type, UnionType):
             types = [
                 self.construct_sequence_child(item, inner_type)
@@ -772,7 +776,6 @@ def construct_sequence_child(self, outer_type: Type, inner_type: Type) -> Type:
             return make_simplified_union(types)
         sequence = self.chk.named_generic_type("typing.Sequence", [inner_type])
         if is_subtype(outer_type, self.chk.named_type("typing.Sequence")):
-            proper_type = get_proper_type(outer_type)
             if isinstance(proper_type, TupleType):
                 proper_type = tuple_fallback(proper_type)
             assert isinstance(proper_type, Instance)

mypyc/test-data/irbuild-match.test

@@ -1378,14 +1378,15 @@ def f(x):
     r15 :: bit
     r16 :: bool
     r17 :: native_int
-    r18, rest :: object
-    r19 :: str
-    r20 :: object
-    r21 :: str
-    r22 :: object
-    r23 :: object[1]
-    r24 :: object_ptr
-    r25, r26 :: object
+    r18 :: object
+    r19, rest :: list
+    r20 :: str
+    r21 :: object
+    r22 :: str
+    r23 :: object
+    r24 :: object[1]
+    r25 :: object_ptr
+    r26, r27 :: object
 L0:
     r0 = CPySequence_Check(x)
     r1 = r0 != 0
@@ -1414,21 +1415,23 @@ L3:
 L4:
     r17 = r2 - 0
     r18 = PySequence_GetSlice(x, 2, r17)
-    rest = r18
+    r19 = cast(list, r18)
+    rest = r19
 L5:
-    r19 = 'matched'
-    r20 = builtins :: module
-    r21 = 'print'
-    r22 = CPyObject_GetAttr(r20, r21)
-    r23 = [r19]
-    r24 = load_address r23
-    r25 = _PyObject_Vectorcall(r22, r24, 1, 0)
-    keep_alive r19
+    r20 = 'matched'
+    r21 = builtins :: module
+    r22 = 'print'
+    r23 = CPyObject_GetAttr(r21, r22)
+    r24 = [r20]
+    r25 = load_address r24
+    r26 = _PyObject_Vectorcall(r23, r25, 1, 0)
+    keep_alive r20
     goto L7
 L6:
 L7:
-    r26 = box(None, 1)
-    return r26
+    r27 = box(None, 1)
+    return r27
+
 [case testMatchSequenceWithStarPatternInTheMiddle_python3_10]
 def f(x):
     match x:
@@ -1455,14 +1458,15 @@ def f(x):
     r16 :: bit
     r17 :: bool
     r18 :: native_int
-    r19, rest :: object
-    r20 :: str
-    r21 :: object
-    r22 :: str
-    r23 :: object
-    r24 :: object[1]
-    r25 :: object_ptr
-    r26, r27 :: object
+    r19 :: object
+    r20, rest :: list
+    r21 :: str
+    r22 :: object
+    r23 :: str
+    r24 :: object
+    r25 :: object[1]
+    r26 :: object_ptr
+    r27, r28 :: object
 L0:
     r0 = CPySequence_Check(x)
     r1 = r0 != 0
@@ -1492,21 +1496,23 @@ L3:
 L4:
     r18 = r2 - 1
     r19 = PySequence_GetSlice(x, 1, r18)
-    rest = r19
+    r20 = cast(list, r19)
+    rest = r20
 L5:
-    r20 = 'matched'
-    r21 = builtins :: module
-    r22 = 'print'
-    r23 = CPyObject_GetAttr(r21, r22)
-    r24 = [r20]
-    r25 = load_address r24
-    r26 = _PyObject_Vectorcall(r23, r25, 1, 0)
-    keep_alive r20
+    r21 = 'matched'
+    r22 = builtins :: module
+    r23 = 'print'
+    r24 = CPyObject_GetAttr(r22, r23)
+    r25 = [r21]
+    r26 = load_address r25
+    r27 = _PyObject_Vectorcall(r24, r26, 1, 0)
+    keep_alive r21
     goto L7
 L6:
 L7:
-    r27 = box(None, 1)
-    return r27
+    r28 = box(None, 1)
+    return r28
+
 [case testMatchSequenceWithStarPatternAtTheStart_python3_10]
 def f(x):
     match x:
@@ -1530,14 +1536,15 @@ def f(x):
     r17 :: bit
     r18 :: bool
     r19 :: native_int
-    r20, rest :: object
-    r21 :: str
-    r22 :: object
-    r23 :: str
-    r24 :: object
-    r25 :: object[1]
-    r26 :: object_ptr
-    r27, r28 :: object
+    r20 :: object
+    r21, rest :: list
+    r22 :: str
+    r23 :: object
+    r24 :: str
+    r25 :: object
+    r26 :: object[1]
+    r27 :: object_ptr
+    r28, r29 :: object
 L0:
     r0 = CPySequence_Check(x)
     r1 = r0 != 0
@@ -1568,21 +1575,23 @@ L3:
 L4:
     r19 = r2 - 2
     r20 = PySequence_GetSlice(x, 0, r19)
-    rest = r20
+    r21 = cast(list, r20)
+    rest = r21
 L5:
-    r21 = 'matched'
-    r22 = builtins :: module
-    r23 = 'print'
-    r24 = CPyObject_GetAttr(r22, r23)
-    r25 = [r21]
-    r26 = load_address r25
-    r27 = _PyObject_Vectorcall(r24, r26, 1, 0)
-    keep_alive r21
+    r22 = 'matched'
+    r23 = builtins :: module
+    r24 = 'print'
+    r25 = CPyObject_GetAttr(r23, r24)
+    r26 = [r22]
+    r27 = load_address r26
+    r28 = _PyObject_Vectorcall(r25, r27, 1, 0)
+    keep_alive r22
     goto L7
 L6:
 L7:
-    r28 = box(None, 1)
-    return r28
+    r29 = box(None, 1)
+    return r29
+
 [case testMatchBuiltinClassPattern_python3_10]
 def f(x):
     match x:
@@ -1634,14 +1643,15 @@ def f(x):
     r2 :: native_int
     r3, r4 :: bit
     r5 :: native_int
-    r6, rest :: object
-    r7 :: str
-    r8 :: object
-    r9 :: str
-    r10 :: object
-    r11 :: object[1]
-    r12 :: object_ptr
-    r13, r14 :: object
+    r6 :: object
+    r7, rest :: list
+    r8 :: str
+    r9 :: object
+    r10 :: str
+    r11 :: object
+    r12 :: object[1]
+    r13 :: object_ptr
+    r14, r15 :: object
 L0:
     r0 = CPySequence_Check(x)
     r1 = r0 != 0
@@ -1654,21 +1664,23 @@ L1:
 L2:
     r5 = r2 - 0
     r6 = PySequence_GetSlice(x, 0, r5)
-    rest = r6
+    r7 = cast(list, r6)
+    rest = r7
 L3:
-    r7 = 'matched'
-    r8 = builtins :: module
-    r9 = 'print'
-    r10 = CPyObject_GetAttr(r8, r9)
-    r11 = [r7]
-    r12 = load_address r11
-    r13 = _PyObject_Vectorcall(r10, r12, 1, 0)
-    keep_alive r7
+    r8 = 'matched'
+    r9 = builtins :: module
+    r10 = 'print'
+    r11 = CPyObject_GetAttr(r9, r10)
+    r12 = [r8]
+    r13 = load_address r12
+    r14 = _PyObject_Vectorcall(r11, r13, 1, 0)
+    keep_alive r8
     goto L5
 L4:
 L5:
-    r14 = box(None, 1)
-    return r14
+    r15 = box(None, 1)
+    return r15
+
 [case testMatchTypeAnnotatedNativeClass_python3_10]
 class A:
     a: int