type_checking: add a type checking helper for strings in include_directories

mesonbuild/interpreter/type_checking.py

@@ -13,6 +13,7 @@ from ..build import (CustomTarget, BuildTarget,
                      BothLibraries, SharedLibrary, StaticLibrary, Jar, Executable)
 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,
@@ -26,6 +27,7 @@ if T.TYPE_CHECKING:
     from typing_extensions import Literal
 
     from ..interpreterbase import TYPE_var
+    from ..interpreterbase.decorators import FeatureCheckBase
 
 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."""
@@ -373,6 +375,13 @@ INCLUDE_DIRECTORIES: KwargInfo[T.List[T.Union[str, IncludeDirs]]] = KwargInfo(
     default=[],
 )
 
+def include_dir_string_new(val: T.List[T.Union[str, IncludeDirs]]) -> T.Iterable[FeatureCheckBase]:
+    strs = [v for v in val if isinstance(v, str)]
+    if strs:
+        str_msg = ", ".join(f"'{s}'" for s in strs)
+        yield FeatureNew('include_directories kwarg of type string', '1.0.0',
+                         f'Use include_directories({str_msg}) instead')
+
 # for cases like default_options and override_options
 DEFAULT_OPTIONS: KwargInfo[T.List[str]] = KwargInfo(
     'default_options',