interpreter: Introduce BooleanHolder for the bool primitive

mesonbuild/ast/interpreter.py

@@ -366,7 +366,8 @@ def quick_resolve(n: BaseNode, loop_detect: T.Optional[T.List[str]] = None) -> T
                 if isinstance(src, str):
                     result = self.string_method_call(src, node.name, margs, mkwargs)
                 elif isinstance(src, bool):
-                    result = self.bool_method_call(src, node.name, margs, mkwargs)
+                    from ..interpreter import Interpreter, BooleanHolder
+                    result = BooleanHolder(src, T.cast(Interpreter, self)).method_call(node.name, margs, mkwargs)
                 elif isinstance(src, int):
                     from ..interpreter import Interpreter, IntegerHolder
                     result = IntegerHolder(src, T.cast(Interpreter, self)).method_call(node.name, margs, mkwargs)

mesonbuild/interpreter/__init__.py

@@ -35,6 +35,7 @@
     'ExternalProgramHolder',
     'extract_required_kwarg',
 
+    'BooleanHolder',
     'IntegerHolder',
 ]
 
@@ -47,5 +48,6 @@
                                  extract_required_kwarg)
 
 from .primitives import (
+    BooleanHolder,
     IntegerHolder,
 )

mesonbuild/interpreter/interpreter.py

@@ -26,7 +26,7 @@
 from ..dependencies import Dependency
 from ..depfile import DepFile
 from ..interpreterbase import ContainerTypeInfo, InterpreterBase, KwargInfo, typed_kwargs, typed_pos_args
-from ..interpreterbase import noPosargs, noKwargs, permittedKwargs, noArgsFlattening, noSecondLevelHolderResolving, permissive_unholder_return
+from ..interpreterbase import noPosargs, noKwargs, permittedKwargs, noArgsFlattening, noSecondLevelHolderResolving, unholder_return
 from ..interpreterbase import InterpreterException, InvalidArguments, InvalidCode, SubdirDoneRequest
 from ..interpreterbase import Disabler, disablerIfNotFound
 from ..interpreterbase import FeatureNew, FeatureDeprecated, FeatureNewKwargs, FeatureDeprecatedKwargs
@@ -381,6 +381,7 @@ def build_holder_map(self) -> None:
         self.holder_map.update({
             # Primitives
             int: P_OBJ.IntegerHolder,
+            bool: P_OBJ.BooleanHolder,
 
             # Meson types
             mesonlib.File: OBJ.FileHolder,

mesonbuild/interpreter/primitives/__init__.py

@@ -2,7 +2,9 @@
 # SPDX-license-identifier: Apache-2.0
 
 __all__ = [
+    'BooleanHolder',
     'IntegerHolder',
 ]
 
+from .boolean import BooleanHolder
 from .integer import IntegerHolder

mesonbuild/interpreter/primitives/boolean.py

@@ -0,0 +1,53 @@
+# Copyright 2021 The Meson development team
+# SPDX-license-identifier: Apache-2.0
+
+from ...interpreterbase import (
+    ObjectHolder,
+    MesonOperator,
+    typed_pos_args,
+    noKwargs,
+    noPosargs,
+
+    TYPE_var,
+    TYPE_kwargs,
+
+    InvalidArguments
+)
+
+import typing as T
+
+if T.TYPE_CHECKING:
+    # Object holders need the actual interpreter
+    from ...interpreter import Interpreter
+
+class BooleanHolder(ObjectHolder[bool]):
+    def __init__(self, obj: bool, interpreter: 'Interpreter') -> None:
+        super().__init__(obj, interpreter)
+        self.methods.update({
+            'to_int': self.to_int_method,
+            'to_string': self.to_string_method,
+        })
+
+        self.trivial_operators.update({
+            MesonOperator.BOOL: (None, lambda x: self.held_object),
+            MesonOperator.NOT: (None, lambda x: not self.held_object),
+            MesonOperator.EQUALS: (bool, lambda x: self.held_object == x),
+            MesonOperator.NOT_EQUALS: (bool, lambda x: self.held_object != x),
+        })
+
+    def display_name(self) -> str:
+        return 'bool'
+
+    @noKwargs
+    @noPosargs
+    def to_int_method(self, args: T.List[TYPE_var], kwargs: TYPE_kwargs) -> int:
+        return 1 if self.held_object else 0
+
+    @noKwargs
+    @typed_pos_args('bool.to_string', optargs=[str, str])
+    def to_string_method(self, args: T.Tuple[T.Optional[str], T.Optional[str]], kwargs: TYPE_kwargs) -> str:
+        true_str = args[0] or 'true'
+        false_str = args[1] or 'false'
+        if any(x is not None for x in args) and not all(x is not None for x in args):
+            raise InvalidArguments('bool.to_string() must have either no arguments or exactly two string arguments that signify what values to return for true and false.')
+        return true_str if self.held_object else false_str

mesonbuild/interpreterbase/baseobjects.py

@@ -129,8 +129,8 @@ class MesonInterpreterObject(InterpreterObject):
 class MutableInterpreterObject:
     ''' Dummy class to mark the object type as mutable '''
 
-HoldableTypes = (HoldableObject, int)
-TYPE_HoldableTypes = T.Union[HoldableObject, int]
+HoldableTypes = (HoldableObject, int, bool)
+TYPE_HoldableTypes = T.Union[HoldableObject, int, bool]
 InterpreterObjectTypeVar = T.TypeVar('InterpreterObjectTypeVar', bound=TYPE_HoldableTypes)
 
 class ObjectHolder(InterpreterObject, T.Generic[InterpreterObjectTypeVar]):

mesonbuild/interpreterbase/decorators.py

@@ -77,11 +77,11 @@ def noSecondLevelHolderResolving(f: TV_func) -> TV_func:
     setattr(f, 'no-second-level-holder-flattening', True)  # noqa: B010
     return f
 
-def permissive_unholder_return(f: TV_func) -> T.Callable[..., TYPE_var]:
+def unholder_return(f: TV_func) -> T.Callable[..., TYPE_var]:
     @wraps(f)
     def wrapped(*wrapped_args: T.Any, **wrapped_kwargs: T.Any) -> T.Any:
         res = f(*wrapped_args, **wrapped_kwargs)
-        return _unholder(res, permissive=True)
+        return _unholder(res)
     return T.cast(T.Callable[..., TYPE_var], wrapped)
 
 def disablerIfNotFound(f: TV_func) -> TV_func: