Use @Final for Value and RType subclasses that shouldn't be subclassed

Author: JukkaL

mypyc/ir/ops.py

@@ -27,7 +27,7 @@ class to enable the new behavior. Sometimes adding a new abstract
 
 from abc import abstractmethod
 from collections.abc import Sequence
-from typing import TYPE_CHECKING, Final, Generic, NamedTuple, TypeVar, Union
+from typing import TYPE_CHECKING, Final, Generic, NamedTuple, TypeVar, Union, final
 
 from mypy_extensions import trait
 
@@ -61,6 +61,7 @@ class to enable the new behavior. Sometimes adding a new abstract
 T = TypeVar("T")
 
 
+@final
 class BasicBlock:
     """IR basic block.
 
@@ -156,6 +157,7 @@ def is_void(self) -> bool:
         return isinstance(self.type, RVoid)
 
 
+@final
 class Register(Value):
     """A Register holds a value of a specific type, and it can be read and mutated.
 
@@ -182,6 +184,7 @@ def __repr__(self) -> str:
         return f"<Register {self.name!r} at {hex(id(self))}>"
 
 
+@final
 class Integer(Value):
     """Short integer literal.
 
@@ -212,6 +215,7 @@ def numeric_value(self) -> int:
         return self.value
 
 
+@final
 class Float(Value):
     """Float literal.
 
@@ -278,6 +282,7 @@ def __init__(self, dest: Register, line: int = -1) -> None:
         self.dest = dest
 
 
+@final
 class Assign(BaseAssign):
     """Assign a value to a Register (dest = src)."""
 
@@ -300,6 +305,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_assign(self)
 
 
+@final
 class AssignMulti(BaseAssign):
     """Assign multiple values to a Register (dest = src1, src2, ...).
 
@@ -345,6 +351,7 @@ def set_target(self, i: int, new: BasicBlock) -> None:
         raise AssertionError(f"Invalid set_target({self}, {i})")
 
 
+@final
 class Goto(ControlOp):
     """Unconditional jump."""
 
@@ -374,6 +381,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_goto(self)
 
 
+@final
 class Branch(ControlOp):
     """Branch based on a value.
 
@@ -440,6 +448,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_branch(self)
 
 
+@final
 class Return(ControlOp):
     """Return a value from a function."""
 
@@ -469,6 +478,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_return(self)
 
 
+@final
 class Unreachable(ControlOp):
     """Mark the end of basic block as unreachable.
 
@@ -525,6 +535,7 @@ def can_raise(self) -> bool:
         return self.error_kind != ERR_NEVER
 
 
+@final
 class IncRef(RegisterOp):
     """Increase reference count (inc_ref src)."""
 
@@ -545,6 +556,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_inc_ref(self)
 
 
+@final
 class DecRef(RegisterOp):
     """Decrease reference count and free object if zero (dec_ref src).
 
@@ -573,6 +585,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_dec_ref(self)
 
 
+@final
 class Call(RegisterOp):
     """Native call f(arg, ...).
 
@@ -601,6 +614,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_call(self)
 
 
+@final
 class MethodCall(RegisterOp):
     """Native method call obj.method(arg, ...)"""
 
@@ -632,6 +646,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_method_call(self)
 
 
+@final
 class PrimitiveDescription:
     """Description of a primitive op.
 
@@ -684,6 +699,7 @@ def __repr__(self) -> str:
         return f"<PrimitiveDescription {self.name!r}: {self.arg_types}>"
 
 
+@final
 class PrimitiveOp(RegisterOp):
     """A higher-level primitive operation.
 
@@ -721,6 +737,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_primitive_op(self)
 
 
+@final
 class LoadErrorValue(RegisterOp):
     """Load an error value.
 
@@ -751,6 +768,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_load_error_value(self)
 
 
+@final
 class LoadLiteral(RegisterOp):
     """Load a Python literal object (dest = 'foo' / b'foo' / ...).
 
@@ -786,6 +804,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_load_literal(self)
 
 
+@final
 class GetAttr(RegisterOp):
     """obj.attr (for a native object)"""
 
@@ -813,6 +832,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_get_attr(self)
 
 
+@final
 class SetAttr(RegisterOp):
     """obj.attr = src (for a native object)
 
@@ -864,6 +884,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
 NAMESPACE_TYPE_VAR: Final = "typevar"
 
 
+@final
 class LoadStatic(RegisterOp):
     """Load a static name (name :: static).
 
@@ -904,6 +925,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_load_static(self)
 
 
+@final
 class InitStatic(RegisterOp):
     """static = value :: static
 
@@ -936,6 +958,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_init_static(self)
 
 
+@final
 class TupleSet(RegisterOp):
     """dest = (reg, ...) (for fixed-length tuple)"""
 
@@ -968,6 +991,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_tuple_set(self)
 
 
+@final
 class TupleGet(RegisterOp):
     """Get item of a fixed-length tuple (src[index])."""
 
@@ -992,6 +1016,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_tuple_get(self)
 
 
+@final
 class Cast(RegisterOp):
     """cast(type, src)
 
@@ -1023,6 +1048,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_cast(self)
 
 
+@final
 class Box(RegisterOp):
     """box(type, src)
 
@@ -1057,6 +1083,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_box(self)
 
 
+@final
 class Unbox(RegisterOp):
     """unbox(type, src)
 
@@ -1083,6 +1110,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_unbox(self)
 
 
+@final
 class RaiseStandardError(RegisterOp):
     """Raise built-in exception with an optional error string.
 
@@ -1122,6 +1150,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
 StealsDescription = Union[bool, list[bool]]
 
 
+@final
 class CallC(RegisterOp):
     """result = function(arg0, arg1, ...)
 
@@ -1176,6 +1205,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_call_c(self)
 
 
+@final
 class Truncate(RegisterOp):
     """result = truncate src from src_type to dst_type
 
@@ -1206,6 +1236,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_truncate(self)
 
 
+@final
 class Extend(RegisterOp):
     """result = extend src from src_type to dst_type
 
@@ -1240,6 +1271,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_extend(self)
 
 
+@final
 class LoadGlobal(RegisterOp):
     """Load a low-level global variable/pointer.
 
@@ -1267,6 +1299,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_load_global(self)
 
 
+@final
 class IntOp(RegisterOp):
     """Binary arithmetic or bitwise op on integer operands (e.g., r1 = r2 + r3).
 
@@ -1331,6 +1364,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
 int_op_to_id: Final = {op: op_id for op_id, op in IntOp.op_str.items()}
 
 
+@final
 class ComparisonOp(RegisterOp):
     """Low-level comparison op for integers and pointers.
 
@@ -1392,6 +1426,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_comparison_op(self)
 
 
+@final
 class FloatOp(RegisterOp):
     """Binary float arithmetic op (e.g., r1 = r2 + r3).
 
@@ -1433,6 +1468,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
 float_op_to_id: Final = {op: op_id for op_id, op in FloatOp.op_str.items()}
 
 
+@final
 class FloatNeg(RegisterOp):
     """Float negation op (r1 = -r2)."""
 
@@ -1453,6 +1489,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_float_neg(self)
 
 
+@final
 class FloatComparisonOp(RegisterOp):
     """Low-level comparison op for floats."""
 
@@ -1489,6 +1526,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
 float_comparison_op_to_id: Final = {op: op_id for op_id, op in FloatComparisonOp.op_str.items()}
 
 
+@final
 class LoadMem(RegisterOp):
     """Read a memory location: result = *(type *)src.
 
@@ -1518,6 +1556,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_load_mem(self)
 
 
+@final
 class SetMem(Op):
     """Write to a memory location: *(type *)dest = src
 
@@ -1549,6 +1588,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_set_mem(self)
 
 
+@final
 class GetElementPtr(RegisterOp):
     """Get the address of a struct element.
 
@@ -1575,6 +1615,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_get_element_ptr(self)
 
 
+@final
 class LoadAddress(RegisterOp):
     """Get the address of a value: result = (type)&src
 
@@ -1609,6 +1650,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_load_address(self)
 
 
+@final
 class KeepAlive(RegisterOp):
     """A no-op operation that ensures source values aren't freed.
 
@@ -1656,6 +1698,7 @@ def accept(self, visitor: OpVisitor[T]) -> T:
         return visitor.visit_keep_alive(self)
 
 
+@final
 class Unborrow(RegisterOp):
     """A no-op op to create a regular reference from a borrowed one.