Fixed gh-998: exception raised while forming an expected TypeError exception message

dpctl/tensor/_types.pxi

@@ -102,28 +102,29 @@ cdef str _make_typestr(int typenum):
     return type_to_str[typenum] + str(type_bytesize(typenum))
 
 
-cdef int typenum_from_format(str s) except *:
+cdef int typenum_from_format(str s):
     """
     Internal utility to convert string describing type format
 
     Format is [<|=>][biufc]#
     Shortcuts for formats are i, u, d, D
     """
     if not s:
-        raise TypeError("Format string '" + s + "' cannot be empty.")
+        return -1
     try:
         dt = np.dtype(s)
-    except Exception as e:
-        raise TypeError("Format '" + s + "' is not understood.") from e
+    except Exception:
+        return -1
     if (dt.byteorder == ">"):
-        raise TypeError("Format '" + s + "' can only have native byteorder.")
+        return -2
     return dt.num
 
+
 cdef int descr_to_typenum(object dtype):
     "Returns typenum for argumentd dtype that has attribute descr, assumed numpy.dtype"
     obj = getattr(dtype, 'descr')
     if (not isinstance(obj, list) or len(obj) != 1):
-        return -1
+        return -1    # token for ValueError
     obj = obj[0]
     if (not isinstance(obj, tuple) or len(obj) != 2 or obj[0]):
         return -1
@@ -133,7 +134,7 @@ cdef int descr_to_typenum(object dtype):
     return typenum_from_format(obj)
 
 
-cdef int dtype_to_typenum(dtype) except *:
+cdef int dtype_to_typenum(dtype):
     if isinstance(dtype, str):
         return typenum_from_format(dtype)
     elif isinstance(dtype, bytes):
@@ -143,9 +144,11 @@ cdef int dtype_to_typenum(dtype) except *:
     else:
         try:
             dt = np.dtype(dtype)
-            if hasattr(dt, 'descr'):
-                return descr_to_typenum(dt)
-            else:
-                return -1
+        except TypeError:
+            return -3
         except Exception:
             return -1
+        if hasattr(dt, 'descr'):
+            return descr_to_typenum(dt)
+        else:
+            return -3  # token for TypeError

dpctl/tensor/_usmarray.pyx

@@ -188,9 +188,15 @@ cdef class usm_ndarray:
                 raise TypeError("Argument shape must be a list or a tuple.")
         nd = len(shape)
         typenum = dtype_to_typenum(dtype)
+        if (typenum < 0):
+            if typenum == -2:
+                raise ValueError("Data type '" + str(dtype) + "' can only have native byteorder.")
+            elif typenum == -1:
+                raise ValueError("Data type '" + str(dtype) + "' is not understood.")
+            raise TypeError(f"Expected string or a dtype object, got {type(dtype)}")
         itemsize = type_bytesize(typenum)
         if (itemsize < 1):
-            raise TypeError("dtype=" + dtype + " is not supported.")
+            raise TypeError("dtype=" + np.dtype(dtype).name + " is not supported.")
         # allocate host C-arrays for shape, strides
         err = _from_input_shape_strides(
             nd, shape, strides, itemsize, <char> ord(order),

dpctl/tests/test_usm_ndarray_ctor.py

@@ -95,13 +95,23 @@ def test_dtypes(dtype):
     assert expected_fmt == actual_fmt
 
 
-@pytest.mark.parametrize("dtype", ["", ">f4", "invalid", 123])
+@pytest.mark.parametrize(
+    "dtype",
+    [
+        "",
+        ">f4",
+        "invalid",
+        123,
+        np.dtype(">f4"),
+        np.dtype([("a", ">f4"), ("b", "i4")]),
+    ],
+)
 def test_dtypes_invalid(dtype):
     with pytest.raises((TypeError, ValueError)):
         dpt.usm_ndarray((1,), dtype=dtype)
 
 
-@pytest.mark.parametrize("dt", ["d", "c16"])
+@pytest.mark.parametrize("dt", ["f", "c8"])
 def test_properties(dt):
     """
     Test that properties execute
@@ -1181,6 +1191,11 @@ def test_empty_like(dt, usm_kind):
     assert X.sycl_queue == Y.sycl_queue
 
 
+def test_empty_unexpected_data_type():
+    with pytest.raises(TypeError):
+        dpt.empty(1, dtype=np.object_)
+
+
 @pytest.mark.parametrize(
     "dt",
     _all_dtypes,