[WIP] Tighten file-api dataclasses

src/scikit_build_core/cmake.py

@@ -13,9 +13,12 @@
 from typing import TYPE_CHECKING, Any
 
 from . import __version__
+from ._compat.builtins import ExceptionGroup
 from ._logging import logger
 from ._shutil import Run
 from .errors import CMakeConfigError, CMakeNotFoundError, FailedLiveProcessError
+from .file_api.query import stateless_query
+from .file_api.reply import load_reply_dir
 from .program_search import Program, best_program, get_cmake_program, get_cmake_programs
 
 if TYPE_CHECKING:
@@ -25,6 +28,7 @@
     from packaging.version import Version
 
     from ._compat.typing import Self
+    from .file_api.model.index import Index
 
 __all__ = ["CMake", "CMaker"]
 
@@ -83,6 +87,8 @@
     init_cache_file: Path = dataclasses.field(init=False, default=Path())
     env: dict[str, str] = dataclasses.field(init=False, default_factory=os.environ.copy)
     single_config: bool = not sysconfig.get_platform().startswith("win")
+    file_api: Index | None = None
+    _file_api_query: Path = dataclasses.field(init=False)
 
     def __post_init__(self) -> None:
         self.init_cache_file = self.build_dir / "CMakeInit.txt"
@@ -97,6 +103,8 @@
             msg = f"build directory {self.build_dir} must be a (creatable) directory"
             raise CMakeConfigError(msg)
 
+        # TODO: This could be stateful instead
+        self._file_api_query = stateless_query(self.build_dir)
         skbuild_info = self.build_dir / ".skbuild-info.json"
         stale = False
 
@@ -253,6 +261,13 @@
             msg = "CMake configuration failed"
             raise FailedLiveProcessError(msg) from None
 
+        try:
+            if self._file_api_query.exists():
+                self.file_api = load_reply_dir(self._file_api_query)
+        except ExceptionGroup:
+            logger.error("Could not parse CMake file-api")
+            raise
+
     def _compute_build_args(
         self,
         *,

src/scikit_build_core/file_api/_cattrs_converter.py

@@ -2,15 +2,22 @@
 
 import builtins
 import json
+from importlib.metadata import version
 from pathlib import Path
-from typing import Any, Callable, Dict, Type, TypeVar  # noqa: TID251
+from typing import Any, Callable, Dict, Type, TypeVar, Union  # noqa: TID251
 
 import cattr
 import cattr.preconf.json
+from cattrs import ClassValidationError
+from packaging.version import Version
 
+from .._compat.typing import get_args
 from .model.cache import Cache
 from .model.cmakefiles import CMakeFiles
 from .model.codemodel import CodeModel, Target
+from .model.codemodel import Directory as CodeModelDirectory
+from .model.common import Paths
+from .model.directory import Directory
 from .model.index import Index, Reply
 
 T = TypeVar("T")
@@ -37,16 +44,33 @@
     converter.register_structure_hook(Reply, st_hook)
 
     def from_json_file(with_path: Dict[str, Any], t: Type[T]) -> T:
+        if "jsonFile" not in with_path and t is CodeModelDirectory:
+            return converter.structure_attrs_fromdict(with_path, t)
         if with_path["jsonFile"] is None:
             return converter.structure_attrs_fromdict({}, t)
         path = base_dir / Path(with_path["jsonFile"])
         raw = json.loads(path.read_text(encoding="utf-8"))
+        if t is CodeModelDirectory:
+            t = Directory  # type: ignore[assignment]
         return converter.structure_attrs_fromdict(raw, t)
 
+    def from_union(obj: Dict[str, Any], t: Type[T]) -> T:
+        for try_type in get_args(t):
+            try:
+                return converter.structure(obj, try_type)  # type: ignore[no-any-return]
+            except ClassValidationError:  # noqa: PERF203
+                continue
+        msg = f"Could not convert {obj} into {t}"
+        raise TypeError(msg)
+
     converter.register_structure_hook(CodeModel, from_json_file)
     converter.register_structure_hook(Target, from_json_file)
     converter.register_structure_hook(Cache, from_json_file)
     converter.register_structure_hook(CMakeFiles, from_json_file)
+    converter.register_structure_hook(CodeModelDirectory, from_json_file)
+    # Workaround for cattrs < 23.2.0 not handling Union with dataclass properly
+    if Version(version("cattrs")) < Version("23.2.0"):
+        converter.register_structure_hook(Union[str, Paths], from_union)
     return converter
 
 

src/scikit_build_core/file_api/model/codemodel.py

@@ -94,7 +94,7 @@ class Sysroot:
 @dataclasses.dataclass(frozen=True)
 class Link:
     language: str
-    commandFragments: List[CommandFragment]
+    commandFragments: List[CommandFragment] = dataclasses.field(default_factory=list)
     lto: Optional[bool] = None
     sysroot: Optional[Sysroot] = None
 

src/scikit_build_core/file_api/reply.py

@@ -11,6 +11,7 @@
 from .model.cache import Cache
 from .model.cmakefiles import CMakeFiles
 from .model.codemodel import CodeModel, Target
+from .model.codemodel import Directory as CodeModelDirectory
 from .model.directory import Directory
 from .model.index import Index
 
@@ -51,10 +52,14 @@ def make_class(self, data: InputDict, target: Type[T]) -> T:
         Convert a dict to a dataclass. Automatically load a few nested jsonFile classes.
         """
         if (
-            target in {CodeModel, Target, Cache, CMakeFiles, Directory}
+            target in {CodeModel, Target, Cache, CMakeFiles, CodeModelDirectory}
             and "jsonFile" in data
             and data["jsonFile"] is not None
         ):
+            # Transform CodeModelDirectory to Directory object
+            # TODO: inherit the fields from CodeModel counterparts
+            if target is CodeModelDirectory:
+                target = Directory  # type: ignore[assignment]
             return self._load_from_json(Path(data["jsonFile"]), target)
 
         input_dict: Dict[str, Type[Any]] = {}