move a bunch of imports into TYPE_CHECKING blocks

These are only used for type checking, so don't bother importing them at
runtime.

Generally add future annotations at the same time, to make sure that
existing uses of these imports don't need to be quoted.

1 files changed, 5 insertions, 3 deletions

diff --git a/mesonbuild/linkers/detect.py b/mesonbuild/linkers/detect.py
index 0bfd7083b..80e0948b9 100644
--- a/mesonbuild/linkers/detect.py
+++ b/mesonbuild/linkers/detect.py
@@ -12,14 +12,14 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from __future__ import annotations
+
 from ..mesonlib import (
-    EnvironmentException, MachineChoice, OptionKey,
+    EnvironmentException, OptionKey,
     Popen_safe, search_version
 )
 from .linkers import (
-    DynamicLinker,
     AppleDynamicLinker,
-    GnuDynamicLinker,
     GnuGoldDynamicLinker,
     GnuBFDDynamicLinker,
     LLVMDynamicLinker,
@@ -36,8 +36,10 @@ import shlex
 import typing as T
 
 if T.TYPE_CHECKING:
+    from .linkers import DynamicLinker, GnuDynamicLinker
     from ..environment import Environment
     from ..compilers import Compiler
+    from ..mesonlib import MachineChoice
 
 defaults: T.Dict[str, T.List[str]] = {}
 defaults['static_linker'] = ['ar', 'gar']