Merge branch 'master' into non-sequence-preallocator

BobTheBuidler · web-flow · commit 90c832470e6a · 2025-09-29T10:54:50.000-04:00
diff --git a/docs/source/command_line.rst b/docs/source/command_line.rst
@@ -372,7 +372,7 @@ definitions or calls.
 
 .. option:: --untyped-calls-exclude
 
-    This flag allows to selectively disable :option:`--disallow-untyped-calls`
+    This flag allows one to selectively disable :option:`--disallow-untyped-calls`
     for functions and methods defined in specific packages, modules, or classes.
     Note that each exclude entry acts as a prefix. For example (assuming there
     are no type annotations for ``third_party_lib`` available):
@@ -562,7 +562,7 @@ potentially problematic or redundant in some way.
 
 .. option:: --deprecated-calls-exclude
 
-    This flag allows to selectively disable :ref:`deprecated<code-deprecated>` warnings
+    This flag allows one to selectively disable :ref:`deprecated<code-deprecated>` warnings
     for functions and methods defined in specific packages, modules, or classes.
     Note that each exclude entry acts as a prefix. For example (assuming ``foo.A.func`` is deprecated):
 
diff --git a/docs/source/error_code_list.rst b/docs/source/error_code_list.rst
@@ -1032,8 +1032,8 @@ Warn about top level await expressions [top-level-await]
 This error code is separate from the general ``[syntax]`` errors, because in
 some environments (e.g. IPython) a top level ``await`` is allowed. In such
 environments a user may want to use ``--disable-error-code=top-level-await``,
-that allows to still have errors for other improper uses of ``await``, for
-example:
+which allows one to still have errors for other improper uses of ``await``,
+for example:
 
 .. code-block:: python
 
diff --git a/docs/source/mypy_daemon.rst b/docs/source/mypy_daemon.rst
@@ -252,16 +252,16 @@ command.
 Statically inspect expressions
 ******************************
 
-The daemon allows to get declared or inferred type of an expression (or other
+The daemon allows one to get the declared or inferred type of an expression (or other
 information about an expression, such as known attributes or definition location)
-using ``dmypy inspect LOCATION`` command. The location of the expression should be
+using the ``dmypy inspect LOCATION`` command. The location of the expression should be
 specified in the format ``path/to/file.py:line:column[:end_line:end_column]``.
 Both line and column are 1-based. Both start and end position are inclusive.
 These rules match how mypy prints the error location in error messages.
 
 If a span is given (i.e. all 4 numbers), then only an exactly matching expression
 is inspected. If only a position is given (i.e. 2 numbers, line and column), mypy
-will inspect all *expressions*, that include this position, starting from the
+will inspect all expressions that include this position, starting from the
 innermost one.
 
 Consider this Python code snippet:
diff --git a/mypy/traverser.py b/mypy/traverser.py
@@ -504,7 +504,7 @@ class ExtendedTraverserVisitor(TraverserVisitor):
     In addition to the base traverser it:
         * has visit_ methods for leaf nodes
         * has common method that is called for all nodes
-        * allows to skip recursing into a node
+        * allows skipping recursing into a node
 
     Note that this traverser still doesn't visit some internal
     mypy constructs like _promote expression and Var.
diff --git a/mypy/type_visitor.py b/mypy/type_visitor.py
@@ -51,7 +51,7 @@
     get_proper_type,
 )
 
-T = TypeVar("T")
+T = TypeVar("T", covariant=True)
 
 
 @trait
diff --git a/mypy/types.py b/mypy/types.py
@@ -3938,8 +3938,12 @@ def visit_type_alias_type(self, t: TypeAliasType, /) -> list[mypy.nodes.TypeAlia
         assert t.alias is not None
         if t.alias not in self.seen_alias_nodes:
             self.seen_alias_nodes.add(t.alias)
-            return [t.alias] + t.alias.target.accept(self)
-        return []
+            res = [t.alias] + t.alias.target.accept(self)
+        else:
+            res = []
+        for arg in t.args:
+            res.extend(arg.accept(self))
+        return res
 
 
 def is_named_instance(t: Type, fullnames: str | tuple[str, ...]) -> TypeGuard[Instance]:
diff --git a/mypyc/codegen/emitclass.py b/mypyc/codegen/emitclass.py
@@ -62,6 +62,7 @@ def dunder_attr_slot(cl: ClassIR, fn: FuncIR, emitter: Emitter) -> str:
     "__hash__": ("tp_hash", generate_hash_wrapper),
     "__get__": ("tp_descr_get", generate_get_wrapper),
     "__getattr__": ("tp_getattro", dunder_attr_slot),
+    "__setattr__": ("tp_setattro", dunder_attr_slot),
 }
 
 AS_MAPPING_SLOT_DEFS: SlotTable = {
diff --git a/mypyc/irbuild/builder.py b/mypyc/irbuild/builder.py
@@ -76,6 +76,7 @@
     Integer,
     IntOp,
     LoadStatic,
+    MethodCall,
     Op,
     PrimitiveDescription,
     RaiseStandardError,
@@ -700,7 +701,12 @@ def get_assignment_target(
         assert False, "Unsupported lvalue: %r" % lvalue
 
     def read(
-        self, target: Value | AssignmentTarget, line: int = -1, can_borrow: bool = False
+        self,
+        target: Value | AssignmentTarget,
+        line: int = -1,
+        *,
+        can_borrow: bool = False,
+        allow_error_value: bool = False,
     ) -> Value:
         if isinstance(target, Value):
             return target
@@ -716,7 +722,15 @@ def read(
         if isinstance(target, AssignmentTargetAttr):
             if isinstance(target.obj.type, RInstance) and target.obj.type.class_ir.is_ext_class:
                 borrow = can_borrow and target.can_borrow
-                return self.add(GetAttr(target.obj, target.attr, line, borrow=borrow))
+                return self.add(
+                    GetAttr(
+                        target.obj,
+                        target.attr,
+                        line,
+                        borrow=borrow,
+                        allow_error_value=allow_error_value,
+                    )
+                )
             else:
                 return self.py_get_attr(target.obj, target.attr, line)
 
@@ -735,8 +749,15 @@ def assign(self, target: Register | AssignmentTarget, rvalue_reg: Value, line: i
             self.add(Assign(target.register, rvalue_reg))
         elif isinstance(target, AssignmentTargetAttr):
             if isinstance(target.obj_type, RInstance):
-                rvalue_reg = self.coerce_rvalue(rvalue_reg, target.type, line)
-                self.add(SetAttr(target.obj, target.attr, rvalue_reg, line))
+                setattr = target.obj_type.class_ir.get_method("__setattr__")
+                if setattr:
+                    key = self.load_str(target.attr)
+                    boxed_reg = self.builder.box(rvalue_reg)
+                    call = MethodCall(target.obj, setattr.name, [key, boxed_reg], line)
+                    self.add(call)
+                else:
+                    rvalue_reg = self.coerce_rvalue(rvalue_reg, target.type, line)
+                    self.add(SetAttr(target.obj, target.attr, rvalue_reg, line))
             else:
                 key = self.load_str(target.attr)
                 boxed_reg = self.builder.box(rvalue_reg)
diff --git a/mypyc/irbuild/expression.py b/mypyc/irbuild/expression.py
@@ -101,6 +101,7 @@
     apply_function_specialization,
     apply_method_specialization,
     translate_object_new,
+    translate_object_setattr,
 )
 from mypyc.primitives.bytes_ops import bytes_slice_op
 from mypyc.primitives.dict_ops import dict_get_item_op, dict_new_op, exact_dict_set_item_op
@@ -480,6 +481,12 @@ def translate_super_method_call(builder: IRBuilder, expr: CallExpr, callee: Supe
             result = translate_object_new(builder, expr, MemberExpr(callee.call, "__new__"))
             if result:
                 return result
+        elif callee.name == "__setattr__":
+            result = translate_object_setattr(
+                builder, expr, MemberExpr(callee.call, "__setattr__")
+            )
+            if result:
+                return result
         if ir.is_ext_class and ir.builtin_base is None and not ir.inherits_python:
             if callee.name == "__init__" and len(expr.args) == 0:
                 # Call translates to object.__init__(self), which is a
diff --git a/mypyc/irbuild/for_helpers.py b/mypyc/irbuild/for_helpers.py
@@ -184,7 +184,12 @@ def for_loop_helper_with_index(
 
     builder.push_loop_stack(step_block, exit_block)
 
-    builder.goto_and_activate(condition_block)
+    if isinstance(length, Integer) and length.value > 0:
+        builder.goto(body_block)
+        builder.activate_block(condition_block)
+    else:
+        builder.goto_and_activate(condition_block)
+
     for_gen.gen_condition()
 
     builder.activate_block(body_block)
diff --git a/mypyc/irbuild/function.py b/mypyc/irbuild/function.py
@@ -57,6 +57,7 @@
 from mypyc.ir.rtypes import (
     RInstance,
     bool_rprimitive,
+    c_int_rprimitive,
     dict_rprimitive,
     int_rprimitive,
     object_rprimitive,
@@ -415,6 +416,34 @@ def generate_getattr_wrapper(builder: IRBuilder, cdef: ClassDef, getattr: FuncDe
         builder.add(Return(getattr_result, line))
 
 
+def generate_setattr_wrapper(builder: IRBuilder, cdef: ClassDef, setattr: FuncDef) -> None:
+    """
+    Generate a wrapper function for __setattr__ that can be put into the tp_setattro slot.
+    The wrapper takes two arguments besides self - attribute name and the new value.
+    Returns 0 on success and -1 on failure. Restrictions are similar to the __getattr__
+    wrapper above.
+
+    This one is simpler because to match interpreted python semantics it's enough to always
+    call the user-provided function, including for names matching regular attributes.
+    """
+    name = setattr.name + "__wrapper"
+    ir = builder.mapper.type_to_ir[cdef.info]
+    line = setattr.line
+
+    error_base = f'"__setattr__" not supported in class "{cdef.name}" because '
+    if ir.allow_interpreted_subclasses:
+        builder.error(error_base + "it allows interpreted subclasses", line)
+    if ir.inherits_python:
+        builder.error(error_base + "it inherits from a non-native class", line)
+
+    with builder.enter_method(ir, name, c_int_rprimitive, internal=True):
+        attr_arg = builder.add_argument("attr", object_rprimitive)
+        value_arg = builder.add_argument("value", object_rprimitive)
+
+        builder.gen_method_call(builder.self(), setattr.name, [attr_arg, value_arg], None, line)
+        builder.add(Return(Integer(0, c_int_rprimitive), line))
+
+
 def handle_ext_method(builder: IRBuilder, cdef: ClassDef, fdef: FuncDef) -> None:
     # Perform the function of visit_method for methods inside extension classes.
     name = fdef.name
@@ -483,6 +512,8 @@ def handle_ext_method(builder: IRBuilder, cdef: ClassDef, fdef: FuncDef) -> None
 
     if fdef.name == "__getattr__":
         generate_getattr_wrapper(builder, cdef, fdef)
+    elif fdef.name == "__setattr__":
+        generate_setattr_wrapper(builder, cdef, fdef)
 
 
 def handle_non_ext_method(
diff --git a/mypyc/irbuild/specialize.py b/mypyc/irbuild/specialize.py
@@ -42,6 +42,7 @@
     Integer,
     RaiseStandardError,
     Register,
+    SetAttr,
     Truncate,
     Unreachable,
     Value,
@@ -97,6 +98,7 @@
     isinstance_dict,
 )
 from mypyc.primitives.float_ops import isinstance_float
+from mypyc.primitives.generic_ops import generic_setattr
 from mypyc.primitives.int_ops import isinstance_int
 from mypyc.primitives.list_ops import isinstance_list, new_list_set_item_op
 from mypyc.primitives.misc_ops import isinstance_bool
@@ -1007,19 +1009,24 @@ def translate_ord(builder: IRBuilder, expr: CallExpr, callee: RefExpr) -> Value
     return None
 
 
-@specialize_function("__new__", object_rprimitive)
-def translate_object_new(builder: IRBuilder, expr: CallExpr, callee: RefExpr) -> Value | None:
-    fn = builder.fn_info
-    if fn.name != "__new__":
-        return None
-
-    is_super_new = isinstance(expr.callee, SuperExpr)
-    is_object_new = (
+def is_object(callee: RefExpr) -> bool:
+    """Returns True for object.<name> calls."""
+    return (
         isinstance(callee, MemberExpr)
         and isinstance(callee.expr, NameExpr)
         and callee.expr.fullname == "builtins.object"
     )
-    if not (is_super_new or is_object_new):
+
+
+def is_super_or_object(expr: CallExpr, callee: RefExpr) -> bool:
+    """Returns True for super().<name> or object.<name> calls."""
+    return isinstance(expr.callee, SuperExpr) or is_object(callee)
+
+
+@specialize_function("__new__", object_rprimitive)
+def translate_object_new(builder: IRBuilder, expr: CallExpr, callee: RefExpr) -> Value | None:
+    fn = builder.fn_info
+    if fn.name != "__new__" or not is_super_or_object(expr, callee):
         return None
 
     ir = builder.get_current_class_ir()
@@ -1046,3 +1053,30 @@ def translate_object_new(builder: IRBuilder, expr: CallExpr, callee: RefExpr) ->
         return builder.add(Call(ir.setup, [subtype], expr.line))
 
     return None
+
+
+@specialize_function("__setattr__", object_rprimitive)
+def translate_object_setattr(builder: IRBuilder, expr: CallExpr, callee: RefExpr) -> Value | None:
+    is_super = isinstance(expr.callee, SuperExpr)
+    is_object_callee = is_object(callee)
+    if not ((is_super and len(expr.args) >= 2) or (is_object_callee and len(expr.args) >= 3)):
+        return None
+
+    self_reg = builder.accept(expr.args[0]) if is_object_callee else builder.self()
+    ir = builder.get_current_class_ir()
+    if ir and (not ir.is_ext_class or ir.builtin_base or ir.inherits_python):
+        return None
+    # Need to offset by 1 for super().__setattr__ calls because there is no self arg in this case.
+    name_idx = 0 if is_super else 1
+    value_idx = 1 if is_super else 2
+    attr_name = expr.args[name_idx]
+    attr_value = expr.args[value_idx]
+    value = builder.accept(attr_value)
+
+    if isinstance(attr_name, StrExpr) and ir and ir.has_attr(attr_name.value):
+        name = attr_name.value
+        value = builder.coerce(value, ir.attributes[name], expr.line)
+        return builder.add(SetAttr(self_reg, name, value, expr.line))
+
+    name_reg = builder.accept(attr_name)
+    return builder.call_c(generic_setattr, [self_reg, name_reg, value], expr.line)
diff --git a/mypyc/irbuild/statement.py b/mypyc/irbuild/statement.py
@@ -829,7 +829,14 @@ def transform_try_finally_stmt_async(
     # Check if we have a return value
     if ret_reg:
         return_block, check_old_exc = BasicBlock(), BasicBlock()
-        builder.add(Branch(builder.read(ret_reg), check_old_exc, return_block, Branch.IS_ERROR))
+        builder.add(
+            Branch(
+                builder.read(ret_reg, allow_error_value=True),
+                check_old_exc,
+                return_block,
+                Branch.IS_ERROR,
+            )
+        )
 
         builder.activate_block(return_block)
         builder.nonlocal_control[-1].gen_return(builder, builder.read(ret_reg), -1)
diff --git a/mypyc/lib-rt/CPy.h b/mypyc/lib-rt/CPy.h
@@ -952,6 +952,9 @@ void CPyTrace_LogEvent(const char *location, const char *line, const char *op, c
 static inline PyObject *CPyObject_GenericGetAttr(PyObject *self, PyObject *name) {
     return _PyObject_GenericGetAttrWithDict(self, name, NULL, 1);
 }
+static inline int CPyObject_GenericSetAttr(PyObject *self, PyObject *name, PyObject *value) {
+    return _PyObject_GenericSetAttrWithDict(self, name, value, NULL);
+}
 
 #if CPY_3_11_FEATURES
 PyObject *CPy_GetName(PyObject *obj);
diff --git a/mypyc/primitives/generic_ops.py b/mypyc/primitives/generic_ops.py
@@ -410,3 +410,10 @@
     error_kind=ERR_NEVER,
     returns_null=True,
 )
+
+generic_setattr = custom_op(
+    arg_types=[object_rprimitive, object_rprimitive, object_rprimitive],
+    return_type=c_int_rprimitive,
+    c_function_name="CPyObject_GenericSetAttr",
+    error_kind=ERR_NEG_INT,
+)
diff --git a/mypyc/test-data/fixtures/ir.py b/mypyc/test-data/fixtures/ir.py
@@ -45,6 +45,7 @@ def __init__(self) -> None: pass
     def __eq__(self, x: object) -> bool: pass
     def __ne__(self, x: object) -> bool: pass
     def __str__(self) -> str: pass
+    def __setattr__(self, k: str, v: object) -> None: pass
 
 class type:
     def __init__(self, o: object) -> None: ...
diff --git a/mypyc/test-data/fixtures/testutil.py b/mypyc/test-data/fixtures/testutil.py
@@ -44,7 +44,7 @@
 def assertRaises(typ: type, msg: str = '') -> Iterator[None]:
     try:
         yield
-    except Exception as e:
+    except BaseException as e:
         assert type(e) is typ, f"{e!r} is not a {typ.__name__}"
         assert msg in str(e), f'Message "{e}" does not match "{msg}"'
     else:
diff --git a/mypyc/test-data/irbuild-classes.test b/mypyc/test-data/irbuild-classes.test
diff --git a/mypyc/test-data/irbuild-lists.test b/mypyc/test-data/irbuild-lists.test
diff --git a/mypyc/test-data/irbuild-tuple.test b/mypyc/test-data/irbuild-tuple.test
diff --git a/mypyc/test-data/run-async.test b/mypyc/test-data/run-async.test
diff --git a/mypyc/test-data/run-classes.test b/mypyc/test-data/run-classes.test
diff --git a/test-data/unit/check-recursive-types.test b/test-data/unit/check-recursive-types.test

Original file line number	Diff line number	Diff line change
`@@ -51,7 +51,7 @@`
`51`	`51`	`get_proper_type,`
`52`	`52`	`)`
`53`	`53`
`54`		`-T = TypeVar("T")`
	`54`	`+T = TypeVar("T", covariant=True)`
`55`	`55`
`56`	`56`
`57`	`57`	`@trait`
Original file line number	Diff line number	Diff line change
`@@ -62,6 +62,7 @@ def dunder_attr_slot(cl: ClassIR, fn: FuncIR, emitter: Emitter) -> str:`
`62`	`62`	`"__hash__": ("tp_hash", generate_hash_wrapper),`
`63`	`63`	`"__get__": ("tp_descr_get", generate_get_wrapper),`
`64`	`64`	`"__getattr__": ("tp_getattro", dunder_attr_slot),`
	`65`	`+ "__setattr__": ("tp_setattro", dunder_attr_slot),`
`65`	`66`	`}`
`66`	`67`
`67`	`68`	`AS_MAPPING_SLOT_DEFS: SlotTable = {`