move various bits of type-checking only code to TYPE_CHECKING blocks

Mostly detected with flake8-type-checking. Also quote T.cast() first
arguments, since those are not affected by future annotations.

9 files changed, 16 insertions, 12 deletions

diff --git a/mesonbuild/build.py b/mesonbuild/build.py
index d588c9d..6438b83 100644
--- a/mesonbuild/build.py
+++ b/mesonbuild/build.py
@@ -26,7 +26,6 @@ import textwrap
 import typing as T
 
 from . import coredata
-from . import environment
 from . import dependencies
 from . import mlog
 from . import programs
@@ -46,6 +45,8 @@ from .interpreterbase import FeatureNew, FeatureDeprecated
 
 if T.TYPE_CHECKING:
     from typing_extensions import Literal
+
+    from . import environment
     from ._typing import ImmutableListProtocol
     from .backend.backends import Backend
     from .compilers import Compiler
diff --git a/mesonbuild/cargo/builder.py b/mesonbuild/cargo/builder.py
index 49bc65d..fb086d1 100644
--- a/mesonbuild/cargo/builder.py
+++ b/mesonbuild/cargo/builder.py
@@ -8,12 +8,14 @@ build descriptions easier.
 """
 
 from __future__ import annotations
-import builtins
 import dataclasses
 import typing as T
 
 from .. import mparser
 
+if T.TYPE_CHECKING:
+    import builtins
+
 
 def _token(tid: str, filename: str, value: mparser.TV_TokenTypes) -> mparser.Token[mparser.TV_TokenTypes]:
     """Create a Token object, but with the line numbers stubbed out.
diff --git a/mesonbuild/cargo/interpreter.py b/mesonbuild/cargo/interpreter.py
index 59e1a1f..8848a46 100644
--- a/mesonbuild/cargo/interpreter.py
+++ b/mesonbuild/cargo/interpreter.py
@@ -21,7 +21,6 @@ import typing as T
 
 from . import builder
 from . import version
-from .. import mparser
 from .._pathlib import Path
 from ..mesonlib import MesonException, Popen_safe
 
@@ -29,6 +28,7 @@ if T.TYPE_CHECKING:
     from types import ModuleType
 
     from . import manifest
+    from .. import mparser
     from ..environment import Environment
 
 # tomllib is present in python 3.11, before that it is a pypi module called tomli,
diff --git a/mesonbuild/environment.py b/mesonbuild/environment.py
index ce7c9f1..3ec7713 100644
--- a/mesonbuild/environment.py
+++ b/mesonbuild/environment.py
@@ -33,7 +33,6 @@ from .envconfig import (
 )
 from . import compilers
 from .compilers import (
-    Compiler,
     is_assembly,
     is_header,
     is_library,
@@ -49,6 +48,7 @@ if T.TYPE_CHECKING:
     import argparse
     from configparser import ConfigParser
 
+    from .compilers import Compiler
     from .wrap.wrap import Resolver
 
     CompilersDict = T.Dict[str, Compiler]
diff --git a/mesonbuild/interpreterbase/interpreterbase.py b/mesonbuild/interpreterbase/interpreterbase.py
index d039f6d..9aff5b9 100644
--- a/mesonbuild/interpreterbase/interpreterbase.py
+++ b/mesonbuild/interpreterbase/interpreterbase.py
@@ -22,7 +22,6 @@ from .baseobjects import (
     InterpreterObject,
     MesonInterpreterObject,
     MutableInterpreterObject,
-    InterpreterObjectTypeVar,
     ObjectHolder,
     IterableObject,
     ContextManagerObject,
@@ -50,7 +49,7 @@ import typing as T
 import textwrap
 
 if T.TYPE_CHECKING:
-    from .baseobjects import SubProject, TYPE_kwargs, TYPE_var
+    from .baseobjects import InterpreterObjectTypeVar, SubProject, TYPE_kwargs, TYPE_var
     from ..interpreter import Interpreter
 
     HolderMapType = T.Dict[
diff --git a/mesonbuild/mintro.py b/mesonbuild/mintro.py
index 1d1e858..063c5cd 100644
--- a/mesonbuild/mintro.py
+++ b/mesonbuild/mintro.py
@@ -429,7 +429,7 @@ def list_deps(coredata: cdata.CoreData, backend: backends.Backend) -> T.List[T.D
             d = holder.held_object
             if isinstance(d, Dependency) and d.found():
                 if d.name in result:
-                    T.cast(T.List[str], result[d.name]['meson_variables']).append(varname)
+                    T.cast('T.List[str]', result[d.name]['meson_variables']).append(varname)
                 else:
                     result[d.name] = _create_result(d, varname)
 
diff --git a/mesonbuild/modules/python.py b/mesonbuild/modules/python.py
index 1f05f08..f6c82e0 100644
--- a/mesonbuild/modules/python.py
+++ b/mesonbuild/modules/python.py
@@ -333,7 +333,7 @@ class PythonModule(ExtensionModule):
 
         for i in self.installations.values():
             if isinstance(i, PythonExternalProgram) and i.run_bytecompile[i.info['version']]:
-                i = T.cast(PythonExternalProgram, i)
+                i = T.cast('PythonExternalProgram', i)
                 manifest = f'python-{i.info["version"]}-installed.json'
                 manifest_json = []
                 for name, f in py_files:
diff --git a/mesonbuild/modules/rust.py b/mesonbuild/modules/rust.py
index 3514412..4f5494a 100644
--- a/mesonbuild/modules/rust.py
+++ b/mesonbuild/modules/rust.py
@@ -18,16 +18,16 @@ import typing as T
 
 from . import ExtensionModule, ModuleReturnValue, ModuleInfo
 from .. import mlog
-from ..build import BothLibraries, BuildTarget, CustomTargetIndex, Executable, ExtractedObjects, GeneratedList, IncludeDirs, CustomTarget, InvalidArguments, Jar, StructuredSources
+from ..build import BothLibraries, BuildTarget, CustomTargetIndex, Executable, ExtractedObjects, GeneratedList, CustomTarget, InvalidArguments, Jar, StructuredSources
 from ..compilers.compilers import are_asserts_disabled
-from ..dependencies import Dependency, ExternalLibrary
 from ..interpreter.type_checking import DEPENDENCIES_KW, LINK_WITH_KW, TEST_KWS, OUTPUT_KW, INCLUDE_DIRECTORIES
 from ..interpreterbase import ContainerTypeInfo, InterpreterException, KwargInfo, typed_kwargs, typed_pos_args, noPosargs
 from ..mesonlib import File
 
 if T.TYPE_CHECKING:
     from . import ModuleState
-    from ..build import LibTypes
+    from ..build import IncludeDirs, LibTypes
+    from ..dependencies import Dependency, ExternalLibrary
     from ..interpreter import Interpreter
     from ..interpreter import kwargs as _kwargs
     from ..interpreter.interpreter import SourceInputs, SourceOutputs
diff --git a/mesonbuild/msubprojects.py b/mesonbuild/msubprojects.py
index 3ecfba1..d1b51f0 100755
--- a/mesonbuild/msubprojects.py
+++ b/mesonbuild/msubprojects.py
@@ -16,12 +16,14 @@ import zipfile
 from . import mlog
 from .ast import IntrospectionInterpreter, AstIDGenerator
 from .mesonlib import quiet_git, GitException, Popen_safe, MesonException, windows_proof_rmtree
-from .wrap.wrap import (Resolver, WrapException, ALL_TYPES, PackageDefinition,
+from .wrap.wrap import (Resolver, WrapException, ALL_TYPES,
                         parse_patch_url, update_wrap_file, get_releases)
 
 if T.TYPE_CHECKING:
     from typing_extensions import Protocol
 
+    from .wrap.wrap import PackageDefinition
+
     SubParsers = argparse._SubParsersAction[argparse.ArgumentParser]
 
     class Arguments(Protocol):