treewide: various cleanups to move imports for mypy into typechecking blocks

Along the way, add __future__ annotations where lacking.

17 files changed, 93 insertions, 59 deletions

diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 178dce9..24b7e3c 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -49,11 +49,12 @@ from ..mesonlib import (
 )
 from ..mesonlib import get_compiler_for_source, has_path_sep, OptionKey
 from .backends import CleanTrees
-from ..build import GeneratedList, InvalidArguments, ExtractedObjects
-from ..interpreter import Interpreter
+from ..build import GeneratedList, InvalidArguments
 
 if T.TYPE_CHECKING:
     from .._typing import ImmutableListProtocol
+    from ..build import ExtractedObjects
+    from ..interpreter import Interpreter
     from ..linkers import DynamicLinker, StaticLinker
     from ..compilers.cs import CsCompiler
 
diff --git a/mesonbuild/backend/vs2010backend.py b/mesonbuild/backend/vs2010backend.py
index 9d3f6c5..fd95a6a 100644
--- a/mesonbuild/backend/vs2010backend.py
+++ b/mesonbuild/backend/vs2010backend.py
@@ -27,12 +27,14 @@ from .. import build
 from .. import dependencies
 from .. import mlog
 from .. import compilers
-from ..interpreter import Interpreter
 from ..mesonlib import (
     File, MesonException, replace_if_different, OptionKey, version_compare, MachineChoice
 )
 from ..environment import Environment, build_filename
 
+if T.TYPE_CHECKING:
+    from ..interpreter import Interpreter
+
 
 def autodetect_vs_version(build: T.Optional[build.Build], interpreter: T.Optional[Interpreter]) -> backends.Backend:
     vs_version = os.getenv('VisualStudioVersion', None)
diff --git a/mesonbuild/backend/vs2012backend.py b/mesonbuild/backend/vs2012backend.py
index ee2f022..af8d5df 100644
--- a/mesonbuild/backend/vs2012backend.py
+++ b/mesonbuild/backend/vs2012backend.py
@@ -11,13 +11,16 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from __future__ import annotations
+
+import typing as T
 
 from .vs2010backend import Vs2010Backend
 from ..mesonlib import MesonException
-from ..interpreter import Interpreter
-from ..build import Build
-import typing as T
 
+if T.TYPE_CHECKING:
+    from ..build import Build
+    from ..interpreter import Interpreter
 
 class Vs2012Backend(Vs2010Backend):
     def __init__(self, build: T.Optional[Build], interpreter: T.Optional[Interpreter]):
diff --git a/mesonbuild/backend/vs2013backend.py b/mesonbuild/backend/vs2013backend.py
index 37724db..44d45d6 100644
--- a/mesonbuild/backend/vs2013backend.py
+++ b/mesonbuild/backend/vs2013backend.py
@@ -11,13 +11,15 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from __future__ import annotations
 
 from .vs2010backend import Vs2010Backend
 from ..mesonlib import MesonException
-from ..interpreter import Interpreter
-from ..build import Build
 import typing as T
 
+if T.TYPE_CHECKING:
+    from ..build import Build
+    from ..interpreter import Interpreter
 
 class Vs2013Backend(Vs2010Backend):
     def __init__(self, build: T.Optional[Build], interpreter: T.Optional[Interpreter]):
diff --git a/mesonbuild/backend/vs2015backend.py b/mesonbuild/backend/vs2015backend.py
index 4952caf..25e0a5e 100644
--- a/mesonbuild/backend/vs2015backend.py
+++ b/mesonbuild/backend/vs2015backend.py
@@ -11,13 +11,16 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from __future__ import annotations
+
+import typing as T
 
 from .vs2010backend import Vs2010Backend
 from ..mesonlib import MesonException
-from ..interpreter import Interpreter
-from ..build import Build
-import typing as T
 
+if T.TYPE_CHECKING:
+    from ..build import Build
+    from ..interpreter import Interpreter
 
 class Vs2015Backend(Vs2010Backend):
     def __init__(self, build: T.Optional[Build], interpreter: T.Optional[Interpreter]):
diff --git a/mesonbuild/backend/vs2017backend.py b/mesonbuild/backend/vs2017backend.py
index e9f949d..4ed5e48 100644
--- a/mesonbuild/backend/vs2017backend.py
+++ b/mesonbuild/backend/vs2017backend.py
@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from __future__ import annotations
 
 import os
 import typing as T
@@ -18,8 +19,10 @@ import xml.etree.ElementTree as ET
 
 from .vs2010backend import Vs2010Backend
 from ..mesonlib import MesonException
-from ..interpreter import Interpreter
-from ..build import Build
+
+if T.TYPE_CHECKING:
+    from ..build import Build
+    from ..interpreter import Interpreter
 
 
 class Vs2017Backend(Vs2010Backend):
diff --git a/mesonbuild/backend/vs2019backend.py b/mesonbuild/backend/vs2019backend.py
index 1efadcd..0734336 100644
--- a/mesonbuild/backend/vs2019backend.py
+++ b/mesonbuild/backend/vs2019backend.py
@@ -11,14 +11,17 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from __future__ import annotations
 
 import os
 import typing as T
 import xml.etree.ElementTree as ET
 
 from .vs2010backend import Vs2010Backend
-from ..interpreter import Interpreter
-from ..build import Build
+
+if T.TYPE_CHECKING:
+    from ..build import Build
+    from ..interpreter import Interpreter
 
 
 class Vs2019Backend(Vs2010Backend):
diff --git a/mesonbuild/backend/vs2022backend.py b/mesonbuild/backend/vs2022backend.py
index b0925a4..b1f93c3 100644
--- a/mesonbuild/backend/vs2022backend.py
+++ b/mesonbuild/backend/vs2022backend.py
@@ -11,14 +11,17 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from __future__ import annotations
 
 import os
 import typing as T
 import xml.etree.ElementTree as ET
 
 from .vs2010backend import Vs2010Backend
-from ..interpreter import Interpreter
-from ..build import Build
+
+if T.TYPE_CHECKING:
+    from ..build import Build
+    from ..interpreter import Interpreter
 
 
 class Vs2022Backend(Vs2010Backend):
diff --git a/mesonbuild/backend/xcodebackend.py b/mesonbuild/backend/xcodebackend.py
index 46f3b14..326c4b6 100644
--- a/mesonbuild/backend/xcodebackend.py
+++ b/mesonbuild/backend/xcodebackend.py
@@ -11,17 +11,20 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from __future__ import annotations
+
+import uuid, os, operator
+import typing as T
 
 from . import backends
 from .. import build
 from .. import dependencies
 from .. import mesonlib
 from .. import mlog
-import uuid, os, operator
-import typing as T
-
 from ..mesonlib import MesonException, OptionKey
-from ..interpreter import Interpreter
+
+if T.TYPE_CHECKING:
+    from ..interpreter import Interpreter
 
 INDENT = '\t'
 XCODETYPEMAP = {'c': 'sourcecode.c.c',
diff --git a/mesonbuild/compilers/rust.py b/mesonbuild/compilers/rust.py
index 0967ada..296c539 100644
--- a/mesonbuild/compilers/rust.py
+++ b/mesonbuild/compilers/rust.py
@@ -11,16 +11,14 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from __future__ import annotations
 
 import subprocess, os.path
 import textwrap
 import typing as T
 
 from .. import coredata
-from ..mesonlib import (
-    EnvironmentException, MachineChoice, MesonException, Popen_safe,
-    OptionKey,
-)
+from ..mesonlib import EnvironmentException, MesonException, Popen_safe, OptionKey
 from .compilers import Compiler, rust_buildtype_args, clike_debug_args
 
 if T.TYPE_CHECKING:
@@ -28,6 +26,7 @@ if T.TYPE_CHECKING:
     from ..envconfig import MachineInfo
     from ..environment import Environment  # noqa: F401
     from ..linkers import DynamicLinker
+    from ..mesonlib import MachineChoice
     from ..programs import ExternalProgram
 
 
diff --git a/mesonbuild/dependencies/boost.py b/mesonbuild/dependencies/boost.py
index 8c552f5..cb432a3 100644
--- a/mesonbuild/dependencies/boost.py
+++ b/mesonbuild/dependencies/boost.py
@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from __future__ import annotations
 
 import re
 import dataclasses
@@ -20,14 +21,13 @@ from pathlib import Path
 
 from .. import mlog
 from .. import mesonlib
-from ..environment import Environment
 
 from .base import DependencyException, SystemDependency
 from .pkgconfig import PkgConfigDependency
 from .misc import threads_factory
 
 if T.TYPE_CHECKING:
-    from ..environment import Properties
+    from ..environment import Environment, Properties
 
 # On windows 3 directory layouts are supported:
 # * The default layout (versioned) installed:
diff --git a/mesonbuild/dependencies/cmake.py b/mesonbuild/dependencies/cmake.py
index 1ae7071..5c4edd4 100644
--- a/mesonbuild/dependencies/cmake.py
+++ b/mesonbuild/dependencies/cmake.py
@@ -11,10 +11,11 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from __future__ import annotations
 
 from .base import ExternalDependency, DependencyException, DependencyTypeName
 from ..mesonlib import is_windows, MesonException, PerMachine, stringlistify, extract_as_list
-from ..cmake import CMakeExecutor, CMakeTraceParser, CMakeException, CMakeToolchain, CMakeExecScope, check_cmake_args, CMakeTarget, resolve_cmake_trace_targets, cmake_is_debug
+from ..cmake import CMakeExecutor, CMakeTraceParser, CMakeException, CMakeToolchain, CMakeExecScope, check_cmake_args, resolve_cmake_trace_targets, cmake_is_debug
 from .. import mlog
 import importlib.resources
 from pathlib import Path
@@ -26,6 +27,7 @@ import textwrap
 import typing as T
 
 if T.TYPE_CHECKING:
+    from ..cmake import CMakeTarget
     from ..environment import Environment
     from ..envconfig import MachineInfo
 
diff --git a/mesonbuild/dependencies/factory.py b/mesonbuild/dependencies/factory.py
index 48cd5ab..8474b51 100644
--- a/mesonbuild/dependencies/factory.py
+++ b/mesonbuild/dependencies/factory.py
@@ -18,7 +18,6 @@ import functools
 import typing as T
 
 from .base import DependencyException, DependencyMethods
-from .base import ExternalDependency
 from .base import process_method_kw
 from .base import BuiltinDependency, SystemDependency
 from .cmake import CMakeDependency
@@ -26,6 +25,7 @@ from .framework import ExtraFrameworkDependency
 from .pkgconfig import PkgConfigDependency
 
 if T.TYPE_CHECKING:
+    from .base import ExternalDependency
     from .configtool import ConfigToolDependency
     from ..environment import Environment
     from ..mesonlib import MachineChoice
diff --git a/mesonbuild/minstall.py b/mesonbuild/minstall.py
index 1531be4..0c69126 100644
--- a/mesonbuild/minstall.py
+++ b/mesonbuild/minstall.py
@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from __future__ import annotations
 
 from glob import glob
 from pathlib import Path
@@ -26,10 +27,7 @@ import typing as T
 
 from . import build
 from . import environment
-from .backend.backends import (
-    InstallData, InstallDataBase, InstallEmptyDir, InstallSymlinkData,
-    TargetInstallData, ExecutableSerialisation
-)
+from .backend.backends import InstallData
 from .coredata import major_versions_differ, MesonVersionMismatchException
 from .coredata import version as coredata_version
 from .mesonlib import MesonException, Popen_safe, RealPathAction, is_windows, setup_vsenv
@@ -43,6 +41,10 @@ except ImportError:
     main_file = None
 
 if T.TYPE_CHECKING:
+    from .backend.backends import (
+            ExecutableSerialisation, InstallDataBase, InstallEmptyDir,
+            InstallSymlinkData, TargetInstallData
+    )
     from .mesonlib import FileMode
 
     try:
diff --git a/mesonbuild/modules/unstable_cuda.py b/mesonbuild/modules/unstable_cuda.py
index 9ab2fd7..6d7f82d 100644
--- a/mesonbuild/modules/unstable_cuda.py
+++ b/mesonbuild/modules/unstable_cuda.py
@@ -11,12 +11,13 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from __future__ import annotations
 
 import typing as T
 import re
 
 from ..mesonlib import version_compare
-from ..compilers import CudaCompiler, Compiler
+from ..compilers import CudaCompiler
 
 from . import NewExtensionModule
 
@@ -27,6 +28,7 @@ from ..interpreterbase import (
 
 if T.TYPE_CHECKING:
     from . import ModuleState
+    from ..compilers import Compiler
 
 class CudaModule(NewExtensionModule):
 
diff --git a/mesonbuild/msubprojects.py b/mesonbuild/msubprojects.py
index 8a58d7d..21f0853 100755
--- a/mesonbuild/msubprojects.py
+++ b/mesonbuild/msubprojects.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from dataclasses import dataclass, InitVar
 import os, subprocess
 import argparse
@@ -13,12 +15,14 @@ import zipfile
 
 from . import mlog
 from .mesonlib import quiet_git, GitException, Popen_safe, MesonException, windows_proof_rmtree
-from .wrap.wrap import PackageDefinition, Resolver, WrapException, ALL_TYPES
+from .wrap.wrap import Resolver, WrapException, ALL_TYPES
 from .wrap import wraptool
 
 if T.TYPE_CHECKING:
     from typing_extensions import Protocol
 
+    from .wrap.wrap import PackageDefinition
+
     class Arguments(Protocol):
         sourcedir: str
         num_processes: int
diff --git a/mesonbuild/scripts/env2mfile.py b/mesonbuild/scripts/env2mfile.py
index 645b953..299fcc9 100755
--- a/mesonbuild/scripts/env2mfile.py
+++ b/mesonbuild/scripts/env2mfile.py
@@ -11,15 +11,17 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from __future__ import annotations
 
 import sys, os, subprocess, shutil
 import shlex
-
-import argparse
-from typing import TextIO, Dict, List, Union, Tuple, Any, Optional
+import typing as T
 
 from .. import mlog
 
+if T.TYPE_CHECKING:
+    import argparse
+
 UNIXY_ENVVARS_COMPILER = {'c': 'CC',
                           'cpp': 'CXX',
                           'objc': 'OBJCC',
@@ -86,16 +88,16 @@ def add_arguments(parser: 'argparse.ArgumentParser') -> None:
 
 class MachineInfo:
     def __init__(self) -> None:
-        self.compilers: Dict[str, List[str]] = {}
-        self.binaries: Dict[str, List[str]] = {}
-        self.properties: Dict[str, Union[str, List[str]]] = {}
-        self.compile_args: Dict[str, List[str]] = {}
-        self.link_args: Dict[str, List[str]] = {}
+        self.compilers: T.Dict[str, T.List[str]] = {}
+        self.binaries: T.Dict[str, T.List[str]] = {}
+        self.properties: T.Dict[str, T.Union[str, T.List[str]]] = {}
+        self.compile_args: T.Dict[str, T.List[str]] = {}
+        self.link_args: T.Dict[str, T.List[str]] = {}
 
-        self.system: Optional[str] = None
-        self.cpu: Optional[str] = None
-        self.cpu_family: Optional[str] = None
-        self.endian: Optional[str] = None
+        self.system: T.Optional[str] = None
+        self.cpu: T.Optional[str] = None
+        self.cpu_family: T.Optional[str] = None
+        self.endian: T.Optional[str] = None
 
 #parser = argparse.ArgumentParser(description='''Generate cross compilation definition file for the Meson build system.
 #
@@ -108,7 +110,7 @@ class MachineInfo:
 #'''
 #)
 
-def locate_path(program: str) -> List[str]:
+def locate_path(program: str) -> T.List[str]:
     if os.path.isabs(program):
         return [program]
     for d in os.get_exec_path():
@@ -117,7 +119,7 @@ def locate_path(program: str) -> List[str]:
             return [f]
     raise ValueError("%s not found on $PATH" % program)
 
-def write_args_line(ofile: TextIO, name: str, args: List[str]) -> None:
+def write_args_line(ofile: T.TextIO, name: str, args: T.List[str]) -> None:
     if len(args) == 0:
         return
     ostr = name + ' = ['
@@ -165,7 +167,7 @@ cpu_family_map = dict(mips64el="mips64",
 cpu_map = dict(armhf="arm7hlf",
                mips64el="mips64",)
 
-def deb_compiler_lookup(infos: MachineInfo, compilerstems: List[Tuple[str, str]], host_arch: str, gccsuffix: str) -> None:
+def deb_compiler_lookup(infos: MachineInfo, compilerstems: T.List[T.Tuple[str, str]], host_arch: str, gccsuffix: str) -> None:
     for langname, stem in compilerstems:
         compilername = f'{host_arch}-{stem}{gccsuffix}'
         try:
@@ -174,7 +176,7 @@ def deb_compiler_lookup(infos: MachineInfo, compilerstems: List[Tuple[str, str]]
         except ValueError:
             pass
 
-def detect_cross_debianlike(options: Any) -> MachineInfo:
+def detect_cross_debianlike(options: T.Any) -> MachineInfo:
     if options.debarch is None:
         cmd = ['dpkg-architecture']
     else:
@@ -258,7 +260,7 @@ def write_machine_file(infos: MachineInfo, ofilename: str, write_system_info: bo
             ofile.write(f"system = '{infos.system}'\n")
     os.replace(tmpfilename, ofilename)
 
-def detect_language_args_from_envvars(langname: str, envvar_suffix: str ='') -> Tuple[List[str], List[str]]:
+def detect_language_args_from_envvars(langname: str, envvar_suffix: str ='') -> T.Tuple[T.List[str], T.List[str]]:
     ldflags = tuple(shlex.split(os.environ.get('LDFLAGS' + envvar_suffix, '')))
     compile_args = shlex.split(os.environ.get(UNIXY_ENVVARS_FLAGS[langname] + envvar_suffix, ''))
     if langname in LANGS_USING_CPPFLAGS:
@@ -291,7 +293,7 @@ def detect_binaries_from_envvars(infos: MachineInfo, envvar_suffix:str ='') -> N
         if binstr:
             infos.binaries[binname] = shlex.split(binstr)
 
-def detect_cross_system(infos: MachineInfo, options: Any) -> None:
+def detect_cross_system(infos: MachineInfo, options: T.Any) -> None:
     for optname in ('system', 'cpu', 'cpu_family', 'endian'):
         v = getattr(options, optname)
         if not v:
@@ -299,7 +301,7 @@ def detect_cross_system(infos: MachineInfo, options: Any) -> None:
             sys.exit(1)
         setattr(infos, optname, v)
 
-def detect_cross_env(options: Any) -> MachineInfo:
+def detect_cross_env(options: T.Any) -> MachineInfo:
     if options.debarch:
         print('Detecting cross environment via dpkg-reconfigure.')
         infos = detect_cross_debianlike(options)
@@ -309,7 +311,7 @@ def detect_cross_env(options: Any) -> MachineInfo:
         detect_cross_system(infos, options)
     return infos
 
-def add_compiler_if_missing(infos: MachineInfo, langname: str, exe_names: List[str]) -> None:
+def add_compiler_if_missing(infos: MachineInfo, langname: str, exe_names: T.List[str]) -> None:
     if langname in infos.compilers:
         return
     for exe_name in exe_names:
@@ -325,12 +327,12 @@ def add_compiler_if_missing(infos: MachineInfo, langname: str, exe_names: List[s
         return
 
 def detect_missing_native_compilers(infos: MachineInfo) -> None:
-    # Any per-platform special detection should go here.
+    # T.Any per-platform special detection should go here.
     for langname, exes in TYPICAL_UNIXY_COMPILER_NAMES.items():
         add_compiler_if_missing(infos, langname, exes)
 
 def detect_missing_native_binaries(infos: MachineInfo) -> None:
-    # Any per-platform special detection should go here.
+    # T.Any per-platform special detection should go here.
     for toolname in sorted(UNIXY_ENVVARS_TOOLS.keys()):
         if toolname in infos.binaries:
             continue
@@ -338,7 +340,7 @@ def detect_missing_native_binaries(infos: MachineInfo) -> None:
         if exe:
             infos.binaries[toolname] = [exe]
 
-def detect_native_env(options: Any) -> MachineInfo:
+def detect_native_env(options: T.Any) -> MachineInfo:
     use_for_build = has_for_build()
     if use_for_build:
         mlog.log('Using FOR_BUILD envvars for detection')
@@ -352,7 +354,7 @@ def detect_native_env(options: Any) -> MachineInfo:
     detect_missing_native_binaries(infos)
     return infos
 
-def run(options: Any) -> None:
+def run(options: T.Any) -> None:
     if options.cross and options.native:
         sys.exit('You can only specify either --cross or --native, not both.')
     if not options.cross and not options.native: