micro-optimize: define typing-only objects in TYPE_CHECKING

Union types that exist solely for use as annotations don't need to be
created in normal runs.

mesonbuild/cmake/executor.py

@@ -33,8 +33,8 @@ if T.TYPE_CHECKING:
     from ..mesonlib import MachineChoice
     from ..programs import ExternalProgram
 
-TYPE_result = T.Tuple[int, T.Optional[str], T.Optional[str]]
-TYPE_cache_key = T.Tuple[str, T.Tuple[str, ...], str, T.FrozenSet[T.Tuple[str, str]]]
+    TYPE_result = T.Tuple[int, T.Optional[str], T.Optional[str]]
+    TYPE_cache_key = T.Tuple[str, T.Tuple[str, ...], str, T.FrozenSet[T.Tuple[str, str]]]
 
 class CMakeExecutor:
     # The class's copy of the CMake path. Avoids having to search for it

mesonbuild/cmake/interpreter.py

@@ -59,9 +59,9 @@ if T.TYPE_CHECKING:
     from ..backend.backends import Backend
     from ..environment import Environment
 
-TYPE_mixed = T.Union[str, int, bool, Path, BaseNode]
-TYPE_mixed_list = T.Union[TYPE_mixed, T.Sequence[TYPE_mixed]]
-TYPE_mixed_kwargs = T.Dict[str, TYPE_mixed_list]
+    TYPE_mixed = T.Union[str, int, bool, Path, BaseNode]
+    TYPE_mixed_list = T.Union[TYPE_mixed, T.Sequence[TYPE_mixed]]
+    TYPE_mixed_kwargs = T.Dict[str, TYPE_mixed_list]
 
 # Disable all warnings automatically enabled with --trace and friends
 # See https://cmake.org/cmake/help/latest/variable/CMAKE_POLICY_WARNING_CMPNNNN.html

mesonbuild/dependencies/cuda.py

@@ -29,7 +29,7 @@ if T.TYPE_CHECKING:
     from ..environment import Environment
     from ..compilers import Compiler
 
-TV_ResultTuple = T.Tuple[T.Optional[str], T.Optional[str], bool]
+    TV_ResultTuple = T.Tuple[T.Optional[str], T.Optional[str], bool]
 
 class CudaDependency(SystemDependency):
 

mesonbuild/environment.py

@@ -51,9 +51,10 @@ if T.TYPE_CHECKING:
 
     from .wrap.wrap import Resolver
 
-build_filename = 'meson.build'
+    CompilersDict = T.Dict[str, Compiler]
+
 
-CompilersDict = T.Dict[str, Compiler]
+build_filename = 'meson.build'
 
 
 def _get_env_var(for_machine: MachineChoice, is_cross: bool, var_name: str) -> T.Optional[str]:

mesonbuild/interpreter/type_checking.py

@@ -15,9 +15,8 @@ from ..coredata import UserFeatureOption
 from ..dependencies import Dependency, InternalDependency
 from ..interpreterbase import FeatureNew
 from ..interpreterbase.decorators import KwargInfo, ContainerTypeInfo
-from ..mesonlib import (
-    File, FileMode, MachineChoice, listify, has_path_sep, OptionKey,
-    EnvInitValueType, EnvironmentVariables)
+from ..mesonlib import (File, FileMode, MachineChoice, listify, has_path_sep,
+                        OptionKey, EnvironmentVariables)
 from ..programs import ExternalProgram
 
 # Helper definition for type checks that are `Optional[T]`
@@ -28,6 +27,10 @@ if T.TYPE_CHECKING:
 
     from ..interpreterbase import TYPE_var
     from ..interpreterbase.decorators import FeatureCheckBase
+    from ..mesonlib import EnvInitValueType
+
+    _FullEnvInitValueType = T.Union[EnvironmentVariables, T.List[str], T.List[T.List[str]], EnvInitValueType, str, None]
+
 
 def in_set_validator(choices: T.Set[str]) -> T.Callable[[str], T.Optional[str]]:
     """Check that the choice given was one of the given set."""
@@ -221,8 +224,6 @@ def split_equal_string(input: str) -> T.Tuple[str, str]:
     a, b = input.split('=', 1)
     return (a, b)
 
-_FullEnvInitValueType = T.Union[EnvironmentVariables, T.List[str], T.List[T.List[str]], EnvInitValueType, str, None]
-
 # Split _env_convertor() and env_convertor_with_method() to make mypy happy.
 # It does not want extra arguments in KwargInfo convertor callable.
 def env_convertor_with_method(value: _FullEnvInitValueType,

mesonbuild/interpreterbase/interpreterbase.py

@@ -27,8 +27,6 @@ from .baseobjects import (
     ObjectHolder,
     IterableObject,
 
-    TYPE_var,
-
     HoldableTypes,
 )
 
@@ -52,26 +50,26 @@ import typing as T
 import textwrap
 
 if T.TYPE_CHECKING:
-    from .baseobjects import SubProject, TYPE_kwargs
+    from .baseobjects import SubProject, TYPE_kwargs, TYPE_var
     from ..interpreter import Interpreter
 
-HolderMapType = T.Dict[
-    T.Union[
-        T.Type[mesonlib.HoldableObject],
-        T.Type[int],
-        T.Type[bool],
-        T.Type[str],
-        T.Type[list],
-        T.Type[dict],
-    ],
-    # For some reason, this has to be a callable and can't just be ObjectHolder[InterpreterObjectTypeVar]
-    T.Callable[[InterpreterObjectTypeVar, 'Interpreter'], ObjectHolder[InterpreterObjectTypeVar]]
-]
-
-FunctionType = T.Dict[
-    str,
-    T.Callable[[mparser.BaseNode, T.List[TYPE_var], T.Dict[str, TYPE_var]], TYPE_var]
-]
+    HolderMapType = T.Dict[
+        T.Union[
+            T.Type[mesonlib.HoldableObject],
+            T.Type[int],
+            T.Type[bool],
+            T.Type[str],
+            T.Type[list],
+            T.Type[dict],
+        ],
+        # For some reason, this has to be a callable and can't just be ObjectHolder[InterpreterObjectTypeVar]
+        T.Callable[[InterpreterObjectTypeVar, 'Interpreter'], ObjectHolder[InterpreterObjectTypeVar]]
+    ]
+
+    FunctionType = T.Dict[
+        str,
+        T.Callable[[mparser.BaseNode, T.List[TYPE_var], T.Dict[str, TYPE_var]], TYPE_var]
+    ]
 
 class InterpreterBase:
     def __init__(self, source_root: str, subdir: str, subproject: 'SubProject'):

mesonbuild/mlog.py

@@ -31,6 +31,8 @@ if T.TYPE_CHECKING:
 
     from .mparser import BaseNode
 
+    TV_Loggable = T.Union[str, 'AnsiDecorator', StringProtocol]
+    TV_LoggableList = T.List[TV_Loggable]
 
 """This is (mostly) a standalone module used to write logging
 information about Meson runs. Some output goes to screen,
@@ -153,9 +155,6 @@ class AnsiDecorator:
     def __str__(self) -> str:
         return self.get_text(colorize_console())
 
-TV_Loggable = T.Union[str, AnsiDecorator, 'StringProtocol']
-TV_LoggableList = T.List[TV_Loggable]
-
 class AnsiText:
     def __init__(self, *args: 'SizedStringProtocol'):
         self.args = args

mesonbuild/mtest.py

@@ -51,6 +51,15 @@ from .mintro import get_infodir, load_info_file
 from .programs import ExternalProgram
 from .backend.backends import TestProtocol, TestSerialisation
 
+if T.TYPE_CHECKING:
+    TYPE_TAPResult = T.Union['TAPParser.Test',
+                             'TAPParser.Error',
+                             'TAPParser.Version',
+                             'TAPParser.Plan',
+                             'TAPParser.UnknownLine',
+                             'TAPParser.Bailout']
+
+
 # GNU autotools interprets a return code of 77 from tests it executes to
 # mean that the test should be skipped.
 GNU_SKIP_RETURNCODE = 77
@@ -272,13 +281,6 @@ class TestResult(enum.Enum):
         return str(self.colorize('>>> '))
 
 
-TYPE_TAPResult = T.Union['TAPParser.Test',
-                         'TAPParser.Error',
-                         'TAPParser.Version',
-                         'TAPParser.Plan',
-                         'TAPParser.UnknownLine',
-                         'TAPParser.Bailout']
-
 class TAPParser:
     class Plan(T.NamedTuple):
         num_tests: int

mesonbuild/utils/core.py

@@ -34,15 +34,7 @@ if T.TYPE_CHECKING:
 
     EnvironOrDict = T.Union[T.Dict[str, str], os._Environ[str]]
 
-
-__all__ = [
-    'MesonException',
-    'MesonBugException',
-    'HoldableObject',
-    'EnvInitValueType',
-    'EnvironmentVariables',
-    'ExecutableSerialisation',
-]
+    EnvInitValueType = T.Dict[str, T.Union[str, T.List[str]]]
 
 
 class MesonException(Exception):
@@ -76,8 +68,6 @@ class HoldableObject(metaclass=abc.ABCMeta):
     ''' Dummy base class for all objects that can be
         held by an interpreter.baseobjects.ObjectHolder '''
 
-EnvInitValueType = T.Dict[str, T.Union[str, T.List[str]]]
-
 class EnvironmentVariables(HoldableObject):
     def __init__(self, values: T.Optional[EnvInitValueType] = None,
                  init_method: Literal['set', 'prepend', 'append'] = 'set', separator: str = os.pathsep) -> None: