interpreter: make trivial_operators per-class

Do not call update() and Enum.__hash__ a gazillion times; trivial
operators are the same for every instance of the class.

Introduce the infrastructure to build the MRO-resolved operators (so
the outcome same as if one called super().__init__) for each subclass
of InterpreterObject.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

6 files changed, 81 insertions, 63 deletions

diff --git a/mesonbuild/interpreter/primitives/array.py b/mesonbuild/interpreter/primitives/array.py
index 6582d4b60..088f1758b 100644
--- a/mesonbuild/interpreter/primitives/array.py
+++ b/mesonbuild/interpreter/primitives/array.py
@@ -27,6 +27,14 @@ if T.TYPE_CHECKING:
     from ...interpreterbase import TYPE_kwargs
 
 class ArrayHolder(ObjectHolder[T.List[TYPE_var]], IterableObject):
+    # Operators that only require type checks
+    TRIVIAL_OPERATORS = {
+        MesonOperator.EQUALS: (list, lambda obj, x: obj.held_object == x),
+        MesonOperator.NOT_EQUALS: (list, lambda obj, x: obj.held_object != x),
+        MesonOperator.IN: (object, lambda obj, x: x in obj.held_object),
+        MesonOperator.NOT_IN: (object, lambda obj, x: x not in obj.held_object),
+    }
+
     def __init__(self, obj: T.List[TYPE_var], interpreter: 'Interpreter') -> None:
         super().__init__(obj, interpreter)
         self.methods.update({
@@ -35,13 +43,6 @@ class ArrayHolder(ObjectHolder[T.List[TYPE_var]], IterableObject):
             'get': self.get_method,
         })
 
-        self.trivial_operators.update({
-            MesonOperator.EQUALS: (list, lambda obj, x: obj.held_object == x),
-            MesonOperator.NOT_EQUALS: (list, lambda obj, x: obj.held_object != x),
-            MesonOperator.IN: (object, lambda obj, x: x in obj.held_object),
-            MesonOperator.NOT_IN: (object, lambda obj, x: x not in obj.held_object),
-        })
-
         # Use actual methods for functions that require additional checks
         self.operators.update({
             MesonOperator.PLUS: ArrayHolder.op_plus,
diff --git a/mesonbuild/interpreter/primitives/boolean.py b/mesonbuild/interpreter/primitives/boolean.py
index 0695e2dd5..c5d6fe028 100644
--- a/mesonbuild/interpreter/primitives/boolean.py
+++ b/mesonbuild/interpreter/primitives/boolean.py
@@ -20,6 +20,13 @@ if T.TYPE_CHECKING:
     from ...interpreterbase import TYPE_var, TYPE_kwargs
 
 class BooleanHolder(ObjectHolder[bool]):
+    TRIVIAL_OPERATORS = {
+        MesonOperator.BOOL: (None, lambda obj, x: obj.held_object),
+        MesonOperator.NOT: (None, lambda obj, x: not obj.held_object),
+        MesonOperator.EQUALS: (bool, lambda obj, x: obj.held_object == x),
+        MesonOperator.NOT_EQUALS: (bool, lambda obj, x: obj.held_object != x),
+    }
+
     def __init__(self, obj: bool, interpreter: 'Interpreter') -> None:
         super().__init__(obj, interpreter)
         self.methods.update({
@@ -27,13 +34,6 @@ class BooleanHolder(ObjectHolder[bool]):
             'to_string': self.to_string_method,
         })
 
-        self.trivial_operators.update({
-            MesonOperator.BOOL: (None, lambda obj, x: obj.held_object),
-            MesonOperator.NOT: (None, lambda obj, x: not obj.held_object),
-            MesonOperator.EQUALS: (bool, lambda obj, x: obj.held_object == x),
-            MesonOperator.NOT_EQUALS: (bool, lambda obj, x: obj.held_object != x),
-        })
-
     def display_name(self) -> str:
         return 'bool'
 
diff --git a/mesonbuild/interpreter/primitives/dict.py b/mesonbuild/interpreter/primitives/dict.py
index ed2986da7..587a3015a 100644
--- a/mesonbuild/interpreter/primitives/dict.py
+++ b/mesonbuild/interpreter/primitives/dict.py
@@ -25,6 +25,18 @@ if T.TYPE_CHECKING:
     from ...interpreterbase import TYPE_kwargs
 
 class DictHolder(ObjectHolder[T.Dict[str, TYPE_var]], IterableObject):
+    # Operators that only require type checks
+    TRIVIAL_OPERATORS = {
+        # Arithmetic
+        MesonOperator.PLUS: (dict, lambda obj, x: {**obj.held_object, **x}),
+
+        # Comparison
+        MesonOperator.EQUALS: (dict, lambda obj, x: obj.held_object == x),
+        MesonOperator.NOT_EQUALS: (dict, lambda obj, x: obj.held_object != x),
+        MesonOperator.IN: (str, lambda obj, x: x in obj.held_object),
+        MesonOperator.NOT_IN: (str, lambda obj, x: x not in obj.held_object),
+    }
+
     def __init__(self, obj: T.Dict[str, TYPE_var], interpreter: 'Interpreter') -> None:
         super().__init__(obj, interpreter)
         self.methods.update({
@@ -33,17 +45,6 @@ class DictHolder(ObjectHolder[T.Dict[str, TYPE_var]], IterableObject):
             'get': self.get_method,
         })
 
-        self.trivial_operators.update({
-            # Arithmetic
-            MesonOperator.PLUS: (dict, lambda obj, x: {**obj.held_object, **x}),
-
-            # Comparison
-            MesonOperator.EQUALS: (dict, lambda obj, x: obj.held_object == x),
-            MesonOperator.NOT_EQUALS: (dict, lambda obj, x: obj.held_object != x),
-            MesonOperator.IN: (str, lambda obj, x: x in obj.held_object),
-            MesonOperator.NOT_IN: (str, lambda obj, x: x not in obj.held_object),
-        })
-
         # Use actual methods for functions that require additional checks
         self.operators.update({
             MesonOperator.INDEX: DictHolder.op_index,
diff --git a/mesonbuild/interpreter/primitives/integer.py b/mesonbuild/interpreter/primitives/integer.py
index 2d0915f7b..48ada78ad 100644
--- a/mesonbuild/interpreter/primitives/integer.py
+++ b/mesonbuild/interpreter/primitives/integer.py
@@ -15,6 +15,23 @@ if T.TYPE_CHECKING:
     from ...interpreterbase import TYPE_var, TYPE_kwargs
 
 class IntegerHolder(ObjectHolder[int]):
+    # Operators that only require type checks
+    TRIVIAL_OPERATORS = {
+        # Arithmetic
+        MesonOperator.UMINUS: (None, lambda obj, x: -obj.held_object),
+        MesonOperator.PLUS: (int, lambda obj, x: obj.held_object + x),
+        MesonOperator.MINUS: (int, lambda obj, x: obj.held_object - x),
+        MesonOperator.TIMES: (int, lambda obj, x: obj.held_object * x),
+
+        # Comparison
+        MesonOperator.EQUALS: (int, lambda obj, x: obj.held_object == x),
+        MesonOperator.NOT_EQUALS: (int, lambda obj, x: obj.held_object != x),
+        MesonOperator.GREATER: (int, lambda obj, x: obj.held_object > x),
+        MesonOperator.LESS: (int, lambda obj, x: obj.held_object < x),
+        MesonOperator.GREATER_EQUALS: (int, lambda obj, x: obj.held_object >= x),
+        MesonOperator.LESS_EQUALS: (int, lambda obj, x: obj.held_object <= x),
+    }
+
     def __init__(self, obj: int, interpreter: 'Interpreter') -> None:
         super().__init__(obj, interpreter)
         self.methods.update({
@@ -23,22 +40,6 @@ class IntegerHolder(ObjectHolder[int]):
             'to_string': self.to_string_method,
         })
 
-        self.trivial_operators.update({
-            # Arithmetic
-            MesonOperator.UMINUS: (None, lambda obj, x: -obj.held_object),
-            MesonOperator.PLUS: (int, lambda obj, x: obj.held_object + x),
-            MesonOperator.MINUS: (int, lambda obj, x: obj.held_object - x),
-            MesonOperator.TIMES: (int, lambda obj, x: obj.held_object * x),
-
-            # Comparison
-            MesonOperator.EQUALS: (int, lambda obj, x: obj.held_object == x),
-            MesonOperator.NOT_EQUALS: (int, lambda obj, x: obj.held_object != x),
-            MesonOperator.GREATER: (int, lambda obj, x: obj.held_object > x),
-            MesonOperator.LESS: (int, lambda obj, x: obj.held_object < x),
-            MesonOperator.GREATER_EQUALS: (int, lambda obj, x: obj.held_object >= x),
-            MesonOperator.LESS_EQUALS: (int, lambda obj, x: obj.held_object <= x),
-        })
-
         # Use actual methods for functions that require additional checks
         self.operators.update({
             MesonOperator.DIV: IntegerHolder.op_div,
diff --git a/mesonbuild/interpreter/primitives/string.py b/mesonbuild/interpreter/primitives/string.py
index 3cb78b310..673adcdc5 100644
--- a/mesonbuild/interpreter/primitives/string.py
+++ b/mesonbuild/interpreter/primitives/string.py
@@ -29,6 +29,19 @@ if T.TYPE_CHECKING:
     from ...interpreterbase import TYPE_var, TYPE_kwargs
 
 class StringHolder(ObjectHolder[str]):
+    TRIVIAL_OPERATORS = {
+        # Arithmetic
+        MesonOperator.PLUS: (str, lambda obj, x: obj.held_object + x),
+
+        # Comparison
+        MesonOperator.EQUALS: (str, lambda obj, x: obj.held_object == x),
+        MesonOperator.NOT_EQUALS: (str, lambda obj, x: obj.held_object != x),
+        MesonOperator.GREATER: (str, lambda obj, x: obj.held_object > x),
+        MesonOperator.LESS: (str, lambda obj, x: obj.held_object < x),
+        MesonOperator.GREATER_EQUALS: (str, lambda obj, x: obj.held_object >= x),
+        MesonOperator.LESS_EQUALS: (str, lambda obj, x: obj.held_object <= x),
+    }
+
     def __init__(self, obj: str, interpreter: 'Interpreter') -> None:
         super().__init__(obj, interpreter)
         self.methods.update({
@@ -49,19 +62,6 @@ class StringHolder(ObjectHolder[str]):
             'version_compare': self.version_compare_method,
         })
 
-        self.trivial_operators.update({
-            # Arithmetic
-            MesonOperator.PLUS: (str, lambda obj, x: obj.held_object + x),
-
-            # Comparison
-            MesonOperator.EQUALS: (str, lambda obj, x: obj.held_object == x),
-            MesonOperator.NOT_EQUALS: (str, lambda obj, x: obj.held_object != x),
-            MesonOperator.GREATER: (str, lambda obj, x: obj.held_object > x),
-            MesonOperator.LESS: (str, lambda obj, x: obj.held_object < x),
-            MesonOperator.GREATER_EQUALS: (str, lambda obj, x: obj.held_object >= x),
-            MesonOperator.LESS_EQUALS: (str, lambda obj, x: obj.held_object <= x),
-        })
-
         # Use actual methods for functions that require additional checks
         self.operators.update({
             MesonOperator.DIV: StringHolder.op_div,
diff --git a/mesonbuild/interpreterbase/baseobjects.py b/mesonbuild/interpreterbase/baseobjects.py
index 32c36f538..928d03861 100644
--- a/mesonbuild/interpreterbase/baseobjects.py
+++ b/mesonbuild/interpreterbase/baseobjects.py
@@ -35,19 +35,34 @@ TYPE_op_func = T.Callable[[TYPE_op_arg, TYPE_op_arg], TYPE_var]
 SubProject = T.NewType('SubProject', str)
 
 class InterpreterObject:
+    TRIVIAL_OPERATORS: T.Dict[
+        MesonOperator,
+        T.Tuple[
+            T.Union[T.Type, T.Tuple[T.Type, ...]],
+            TYPE_op_func
+        ]
+    ] = {}
+
+    def __init_subclass__(cls: T.Type[InterpreterObject], **kwargs: T.Any) -> None:
+        super().__init_subclass__(**kwargs)
+        saved_trivial_operators = cls.TRIVIAL_OPERATORS
+        cls.TRIVIAL_OPERATORS = {}
+
+        # Compute inherited operators according to the Python resolution order
+        # Reverse the result of mro() because update() will overwrite operators
+        # that are set by the superclass with those that are set by the subclass
+        for superclass in reversed(cls.mro()[1:]):
+            if issubclass(superclass, InterpreterObject):
+                cls.TRIVIAL_OPERATORS.update(superclass.TRIVIAL_OPERATORS)
+
+        cls.TRIVIAL_OPERATORS.update(saved_trivial_operators)
+
     def __init__(self, *, subproject: T.Optional['SubProject'] = None) -> None:
         self.methods: T.Dict[
             str,
             T.Callable[[T.List[TYPE_var], TYPE_kwargs], TYPE_var]
         ] = {}
         self.operators: T.Dict[MesonOperator, TYPE_op_func] = {}
-        self.trivial_operators: T.Dict[
-            MesonOperator,
-            T.Tuple[
-                T.Union[T.Type, T.Tuple[T.Type, ...]],
-                TYPE_op_func
-            ]
-        ] = {}
         # Current node set during a method call. This can be used as location
         # when printing a warning message during a method call.
         self.current_node:  mparser.BaseNode = None
@@ -79,8 +94,8 @@ class InterpreterObject:
         raise InvalidCode(f'Unknown method "{method_name}" in object {self} of type {type(self).__name__}.')
 
     def operator_call(self, operator: MesonOperator, other: TYPE_var) -> TYPE_var:
-        if operator in self.trivial_operators:
-            op = self.trivial_operators[operator]
+        if operator in self.TRIVIAL_OPERATORS:
+            op = self.TRIVIAL_OPERATORS[operator]
             if op[0] is None and other is not None:
                 raise MesonBugException(f'The unary operator `{operator.value}` of {self.display_name()} was passed the object {other} of type {type(other).__name__}')
             if op[0] is not None and not isinstance(other, op[0]):