Add get_coreclr_command_line which uses hostfxr_initialize_for_dotnet_command_line (#66)

see https://github.com/dotnet/runtime/blob/main/docs/design/features/native-hosting.md#initializing-host-context

Author: elan-slovelock

clr_loader/__init__.py

@@ -11,6 +11,7 @@
     "get_mono",
     "get_netfx",
     "get_coreclr",
+    "get_coreclr_command_line",
     "find_dotnet_root",
     "find_libmono",
     "find_runtimes",
@@ -152,6 +153,39 @@ def get_coreclr(
     return impl
 
 
+def get_coreclr_command_line(
+    *,
+    entry_dll: StrOrPath,
+    dotnet_root: Optional[StrOrPath] = None,
+    properties: Optional[Dict[str, str]] = None
+) -> Runtime:
+    """Get a CoreCLR (.NET Core) runtime instance
+    The returned ``DotnetCoreRuntimeCommandLine`` also acts as a mapping of the config
+    properties. They can be retrieved using the index operator and can be
+    written until the runtime is initialized. The runtime is initialized when
+    the first function object is retrieved.
+    :param entry_dll:
+        The path to the entry dll.
+    :param dotnet_root:
+        The root directory of the .NET Core installation. If this is not
+        specified, we try to discover it using :py:func:`find_dotnet_root`.
+    :param properties:
+        Additional runtime properties. These can also be passed using the
+        ``configProperties`` section in the runtime config."""
+    from .hostfxr import DotnetCoreCommandRuntime
+
+    dotnet_root = _maybe_path(dotnet_root)
+    if dotnet_root is None:
+        dotnet_root = find_dotnet_root()
+
+    impl = DotnetCoreCommandRuntime(entry_dll=_maybe_path(entry_dll), dotnet_root=dotnet_root)
+    if properties:
+        for key, value in properties.items():
+            impl[key] = value
+
+    return impl
+
+
 def get_netfx(
     *, domain: Optional[str] = None, config_file: Optional[StrOrPath] = None
 ) -> Runtime:

clr_loader/hostfxr.py

@@ -6,29 +6,24 @@
 from .types import Runtime, RuntimeInfo, StrOrPath
 from .util import check_result
 
-__all__ = ["DotnetCoreRuntime"]
+__all__ = ["DotnetCoreRuntime", "DotnetCoreCommandRuntime"]
 
 _IS_SHUTDOWN = False
 
 
-class DotnetCoreRuntime(Runtime):
-    def __init__(self, runtime_config: Path, dotnet_root: Path, **params: str):
+class DotnetCoreRuntimeBase(Runtime):
+    _version: str
+
+    def __init__(self, dotnet_root: Path):
         self._handle = None
 
         if _IS_SHUTDOWN:
             raise RuntimeError("Runtime can not be reinitialized")
 
         self._dotnet_root = Path(dotnet_root)
         self._dll = load_hostfxr(self._dotnet_root)
-        self._handle = _get_handle(self._dll, self._dotnet_root, runtime_config)
         self._load_func = None
 
-        for key, value in params.items():
-            self[key] = value
-
-        # TODO: Get version
-        self._version = "<undefined>"
-
     @property
     def dotnet_root(self) -> Path:
         return self._dotnet_root
@@ -122,7 +117,31 @@ def info(self):
         )
 
 
-def _get_handle(dll, dotnet_root: StrOrPath, runtime_config: StrOrPath):
+class DotnetCoreRuntime(DotnetCoreRuntimeBase):
+    def __init__(self, runtime_config: Path, dotnet_root: Path, **params: str):
+        super().__init__(dotnet_root)
+        self._handle = _get_handle_for_runtime_config(self._dll, self._dotnet_root, runtime_config)
+
+        for key, value in params.items():
+            self[key] = value
+
+        # TODO: Get version
+        self._version = "<undefined>"
+
+
+class DotnetCoreCommandRuntime(DotnetCoreRuntimeBase):
+    def __init__(self, entry_dll: Path, dotnet_root: Path, **params: str):
+        super().__init__(dotnet_root)
+        self._handle = _get_handle_for_dotnet_command_line(self._dll, self._dotnet_root, entry_dll)
+
+        for key, value in params.items():
+            self[key] = value
+
+        # TODO: Get version
+        self._version = "<undefined>"
+
+
+def _get_handle_for_runtime_config(dll, dotnet_root: StrOrPath, runtime_config: StrOrPath):
     params = ffi.new("hostfxr_initialize_parameters*")
     params.size = ffi.sizeof("hostfxr_initialize_parameters")
     # params.host_path = ffi.new("char_t[]", encode(sys.executable))
@@ -140,6 +159,29 @@ def _get_handle(dll, dotnet_root: StrOrPath, runtime_config: StrOrPath):
     return handle_ptr[0]
 
 
+def _get_handle_for_dotnet_command_line(dll, dotnet_root: StrOrPath, entry_dll: StrOrPath):
+    params = ffi.new("hostfxr_initialize_parameters*")
+    params.size = ffi.sizeof("hostfxr_initialize_parameters")
+    params.host_path = ffi.NULL
+    dotnet_root_p = ffi.new("char_t[]", encode(str(Path(dotnet_root))))
+    params.dotnet_root = dotnet_root_p
+
+    handle_ptr = ffi.new("hostfxr_handle*")
+
+    args_ptr = ffi.new("char_t*[1]")
+    arg_ptr = ffi.new("char_t[]", encode(str(Path(entry_dll))))
+    args_ptr[0] = arg_ptr
+    res = dll.hostfxr_initialize_for_dotnet_command_line(
+        1,
+        args_ptr,
+        params, handle_ptr
+    )
+
+    check_result(res)
+
+    return handle_ptr[0]
+
+
 def _get_load_func(dll, handle):
     delegate_ptr = ffi.new("void**")
 

tests/test_common.py

@@ -92,6 +92,19 @@ def test_coreclr(example_netcore: Path):
     run_tests(asm)
 
 
+def test_coreclr_command_line(example_netcore: Path):
+    run_in_subprocess(_do_test_coreclr_command_line, example_netcore)
+
+
+def _do_test_coreclr_command_line(example_netcore):
+    from clr_loader import get_coreclr_command_line
+
+    coreclr = get_coreclr_command_line(entry_dll=example_netcore / "example.dll")
+    asm = coreclr.get_assembly(example_netcore / "example.dll")
+
+    run_tests(asm)
+
+
 def test_coreclr_properties(example_netcore: Path):
     run_in_subprocess(
         _do_test_coreclr_autogenerated_runtimeconfig,