TST: Account for the platform-specific mapping of numpy- to ctypes-types

2 files changed, 74 insertions, 37 deletions

diff --git a/numpy/typing/tests/data/reveal/ctypeslib.pyi b/numpy/typing/tests/data/reveal/ctypeslib.pyi
index ae0b6b345..461a447d9 100644
--- a/numpy/typing/tests/data/reveal/ctypeslib.pyi
+++ b/numpy/typing/tests/data/reveal/ctypeslib.pyi
@@ -17,6 +17,7 @@ AR_int: npt.NDArray[np.int_]
 AR_longlong: npt.NDArray[np.longlong]
 AR_single: npt.NDArray[np.single]
 AR_double: npt.NDArray[np.double]
+AR_longdouble: npt.NDArray[np.longdouble]
 AR_void: npt.NDArray[np.void]
 
 pointer: ctypes.pointer[Any]
@@ -31,51 +32,54 @@ reveal_type(np.ctypeslib.ndpointer(np.int64, shape=(10, 3)))  # E: Type[numpy.ct
 reveal_type(np.ctypeslib.ndpointer(int, shape=(1,)))  # E: Type[numpy.ctypeslib._concrete_ndptr[numpy.dtype[Any]]]
 
 reveal_type(np.ctypeslib.as_ctypes_type(np.bool_))  # E: Type[ctypes.c_bool]
-reveal_type(np.ctypeslib.as_ctypes_type(np.ubyte))  # E: Type[ctypes.c_ubyte]
-reveal_type(np.ctypeslib.as_ctypes_type(np.ushort))  # E: Type[ctypes.c_ushort]
-reveal_type(np.ctypeslib.as_ctypes_type(np.uintc))  # E: Type[ctypes.c_uint]
-reveal_type(np.ctypeslib.as_ctypes_type(np.uint))  # E: Type[ctypes.c_ulong]
-reveal_type(np.ctypeslib.as_ctypes_type(np.ulonglong))  # E: Type[ctypes.c_ulong]
-reveal_type(np.ctypeslib.as_ctypes_type(np.byte))  # E: Type[ctypes.c_byte]
-reveal_type(np.ctypeslib.as_ctypes_type(np.short))  # E: Type[ctypes.c_short]
-reveal_type(np.ctypeslib.as_ctypes_type(np.intc))  # E: Type[ctypes.c_int]
-reveal_type(np.ctypeslib.as_ctypes_type(np.int_))  # E: Type[ctypes.c_long]
-reveal_type(np.ctypeslib.as_ctypes_type(np.longlong))  # E: Type[ctypes.c_long]
-reveal_type(np.ctypeslib.as_ctypes_type(np.single))  # E: Type[ctypes.c_float]
-reveal_type(np.ctypeslib.as_ctypes_type(np.double))  # E: Type[ctypes.c_double]
-reveal_type(np.ctypeslib.as_ctypes_type(ctypes.c_double))  # E: Type[ctypes.c_double]
+reveal_type(np.ctypeslib.as_ctypes_type(np.ubyte))  # E: Type[{c_ubyte}]
+reveal_type(np.ctypeslib.as_ctypes_type(np.ushort))  # E: Type[{c_ushort}]
+reveal_type(np.ctypeslib.as_ctypes_type(np.uintc))  # E: Type[{c_uint}]
+reveal_type(np.ctypeslib.as_ctypes_type(np.uint))  # E: Type[{c_ulong}]
+reveal_type(np.ctypeslib.as_ctypes_type(np.ulonglong))  # E: Type[{c_ulonglong}]
+reveal_type(np.ctypeslib.as_ctypes_type(np.byte))  # E: Type[{c_byte}]
+reveal_type(np.ctypeslib.as_ctypes_type(np.short))  # E: Type[{c_short}]
+reveal_type(np.ctypeslib.as_ctypes_type(np.intc))  # E: Type[{c_int}]
+reveal_type(np.ctypeslib.as_ctypes_type(np.int_))  # E: Type[{c_long}]
+reveal_type(np.ctypeslib.as_ctypes_type(np.longlong))  # E: Type[{c_longlong}]
+reveal_type(np.ctypeslib.as_ctypes_type(np.single))  # E: Type[{c_float}]
+reveal_type(np.ctypeslib.as_ctypes_type(np.double))  # E: Type[{c_double}]
+reveal_type(np.ctypeslib.as_ctypes_type(np.longdouble))  # E: Type[{c_longdouble}]
+reveal_type(np.ctypeslib.as_ctypes_type(ctypes.c_double))  # E: Type[{c_double}]
 reveal_type(np.ctypeslib.as_ctypes_type("q"))  # E: Type[ctypes.c_longlong]
 reveal_type(np.ctypeslib.as_ctypes_type([("i8", np.int64), ("f8", np.float64)]))  # E: Type[Any]
 reveal_type(np.ctypeslib.as_ctypes_type("i8"))  # E: Type[Any]
 reveal_type(np.ctypeslib.as_ctypes_type("f8"))  # E: Type[Any]
 
 reveal_type(np.ctypeslib.as_ctypes(AR_bool.take(0)))  # E: ctypes.c_bool
-reveal_type(np.ctypeslib.as_ctypes(AR_ubyte.take(0)))  # E: ctypes.c_ubyte
-reveal_type(np.ctypeslib.as_ctypes(AR_ushort.take(0)))  # E: ctypes.c_ushort
-reveal_type(np.ctypeslib.as_ctypes(AR_uintc.take(0)))  # E: ctypes.c_uint
-reveal_type(np.ctypeslib.as_ctypes(AR_uint.take(0)))  # E: ctypes.c_ulong
-reveal_type(np.ctypeslib.as_ctypes(AR_ulonglong.take(0)))  # E: ctypes.c_ulong
-reveal_type(np.ctypeslib.as_ctypes(AR_byte.take(0)))  # E: ctypes.c_byte
-reveal_type(np.ctypeslib.as_ctypes(AR_short.take(0)))  # E: ctypes.c_short
-reveal_type(np.ctypeslib.as_ctypes(AR_intc.take(0)))  # E: ctypes.c_int
-reveal_type(np.ctypeslib.as_ctypes(AR_int.take(0)))  # E: ctypes.c_long
-reveal_type(np.ctypeslib.as_ctypes(AR_longlong.take(0)))  # E: ctypes.c_long
-reveal_type(np.ctypeslib.as_ctypes(AR_single.take(0)))  # E: ctypes.c_float
-reveal_type(np.ctypeslib.as_ctypes(AR_double.take(0)))  # E: ctypes.c_double
+reveal_type(np.ctypeslib.as_ctypes(AR_ubyte.take(0)))  # E: {c_ubyte}
+reveal_type(np.ctypeslib.as_ctypes(AR_ushort.take(0)))  # E: {c_ushort}
+reveal_type(np.ctypeslib.as_ctypes(AR_uintc.take(0)))  # E: {c_uint}
+reveal_type(np.ctypeslib.as_ctypes(AR_uint.take(0)))  # E: {c_ulong}
+reveal_type(np.ctypeslib.as_ctypes(AR_ulonglong.take(0)))  # E: {c_ulonglong}
+reveal_type(np.ctypeslib.as_ctypes(AR_byte.take(0)))  # E: {c_byte}
+reveal_type(np.ctypeslib.as_ctypes(AR_short.take(0)))  # E: {c_short}
+reveal_type(np.ctypeslib.as_ctypes(AR_intc.take(0)))  # E: {c_int}
+reveal_type(np.ctypeslib.as_ctypes(AR_int.take(0)))  # E: {c_long}
+reveal_type(np.ctypeslib.as_ctypes(AR_longlong.take(0)))  # E: {c_longlong}
+reveal_type(np.ctypeslib.as_ctypes(AR_single.take(0)))  # E: {c_float}
+reveal_type(np.ctypeslib.as_ctypes(AR_double.take(0)))  # E: {c_double}
+reveal_type(np.ctypeslib.as_ctypes(AR_longdouble.take(0)))  # E: {c_longdouble}
 reveal_type(np.ctypeslib.as_ctypes(AR_void.take(0)))  # E: Any
 reveal_type(np.ctypeslib.as_ctypes(AR_bool))  # E: ctypes.Array[ctypes.c_bool]
-reveal_type(np.ctypeslib.as_ctypes(AR_ubyte))  # E: ctypes.Array[ctypes.c_ubyte]
-reveal_type(np.ctypeslib.as_ctypes(AR_ushort))  # E: ctypes.Array[ctypes.c_ushort]
-reveal_type(np.ctypeslib.as_ctypes(AR_uintc))  # E: ctypes.Array[ctypes.c_uint]
-reveal_type(np.ctypeslib.as_ctypes(AR_uint))  # E: ctypes.Array[ctypes.c_ulong]
-reveal_type(np.ctypeslib.as_ctypes(AR_ulonglong))  # E: ctypes.Array[ctypes.c_ulong]
-reveal_type(np.ctypeslib.as_ctypes(AR_byte))  # E: ctypes.Array[ctypes.c_byte]
-reveal_type(np.ctypeslib.as_ctypes(AR_short))  # E: ctypes.Array[ctypes.c_short]
-reveal_type(np.ctypeslib.as_ctypes(AR_intc))  # E: ctypes.Array[ctypes.c_int]
-reveal_type(np.ctypeslib.as_ctypes(AR_int))  # E: ctypes.Array[ctypes.c_long]
-reveal_type(np.ctypeslib.as_ctypes(AR_longlong))  # E: ctypes.Array[ctypes.c_long]
-reveal_type(np.ctypeslib.as_ctypes(AR_single))  # E: ctypes.Array[ctypes.c_float]
-reveal_type(np.ctypeslib.as_ctypes(AR_double))  # E: ctypes.Array[ctypes.c_double]
+reveal_type(np.ctypeslib.as_ctypes(AR_ubyte))  # E: ctypes.Array[{c_ubyte}]
+reveal_type(np.ctypeslib.as_ctypes(AR_ushort))  # E: ctypes.Array[{c_ushort}]
+reveal_type(np.ctypeslib.as_ctypes(AR_uintc))  # E: ctypes.Array[{c_uint}]
+reveal_type(np.ctypeslib.as_ctypes(AR_uint))  # E: ctypes.Array[{c_ulong}]
+reveal_type(np.ctypeslib.as_ctypes(AR_ulonglong))  # E: ctypes.Array[{c_ulonglong}]
+reveal_type(np.ctypeslib.as_ctypes(AR_byte))  # E: ctypes.Array[{c_byte}]
+reveal_type(np.ctypeslib.as_ctypes(AR_short))  # E: ctypes.Array[{c_short}]
+reveal_type(np.ctypeslib.as_ctypes(AR_intc))  # E: ctypes.Array[{c_int}]
+reveal_type(np.ctypeslib.as_ctypes(AR_int))  # E: ctypes.Array[{c_long}]
+reveal_type(np.ctypeslib.as_ctypes(AR_longlong))  # E: ctypes.Array[{c_longlong}]
+reveal_type(np.ctypeslib.as_ctypes(AR_single))  # E: ctypes.Array[{c_float}]
+reveal_type(np.ctypeslib.as_ctypes(AR_double))  # E: ctypes.Array[{c_double}]
+reveal_type(np.ctypeslib.as_ctypes(AR_longdouble))  # E: ctypes.Array[{c_longdouble}]
 reveal_type(np.ctypeslib.as_ctypes(AR_void))  # E: ctypes.Array[Any]
 
 reveal_type(np.ctypeslib.as_array(AR_ubyte))  # E: numpy.ndarray[Any, numpy.dtype[{ubyte}]]
diff --git a/numpy/typing/tests/test_typing.py b/numpy/typing/tests/test_typing.py
index 71e459df6..e0bcacd06 100644
--- a/numpy/typing/tests/test_typing.py
+++ b/numpy/typing/tests/test_typing.py
@@ -187,6 +187,38 @@ def _test_fail(
         raise AssertionError(_FAIL_MSG2.format(lineno, expression, expected_error, error))
 
 
+def _construct_ctypes_dict() -> dict[str, str]:
+    dct = {
+        "ubyte": "c_ubyte",
+        "ushort": "c_ushort",
+        "uintc": "c_uint",
+        "uint": "c_ulong",
+        "ulonglong": "c_ulonglong",
+        "byte": "c_byte",
+        "short": "c_short",
+        "intc": "c_int",
+        "int_": "c_long",
+        "longlong": "c_longlong",
+        "single": "c_float",
+        "double": "c_double",
+        "longdouble": "c_longdouble",
+    }
+
+    # Match `ctypes` names to the first ctypes type with a given kind and
+    # precision, e.g. {"c_double": "c_double", "c_longdouble": "c_double"}
+    # if both types represent 64-bit floats.
+    # In this context "first" is defined by the order of `dct`
+    ret = {}
+    visited: dict[tuple[str, int], str] = {}
+    for np_name, ct_name in dct.items():
+        np_scalar = getattr(np, np_name)()
+
+        # Find the first `ctypes` type for a given `kind`/`itemsize` combo
+        key = (np_scalar.dtype.kind, np_scalar.dtype.itemsize)
+        ret[ct_name] = visited.setdefault(key, f"ctypes.{ct_name}")
+    return ret
+
+
 def _construct_format_dict() -> dict[str, str]:
     dct = {k.split(".")[-1]: v.replace("numpy", "numpy.typing") for
            k, v in _PRECISION_DICT.items()}
@@ -261,6 +293,7 @@ def _construct_format_dict() -> dict[str, str]:
 #: A dictionary with all supported format keys (as keys)
 #: and matching values
 FORMAT_DICT: dict[str, str] = _construct_format_dict()
+FORMAT_DICT.update(_construct_ctypes_dict())
 
 
 def _parse_reveals(file: IO[str]) -> tuple[npt.NDArray[np.str_], list[str]]: