Merge pull request #22542 from seberg/dlpack-buffererror

API: Always use BufferError when dlpack export fails

2 files changed, 22 insertions, 19 deletions

diff --git a/numpy/core/src/multiarray/dlpack.c b/numpy/core/src/multiarray/dlpack.c
index 5a46d5a85..b20674f5e 100644
--- a/numpy/core/src/multiarray/dlpack.c
+++ b/numpy/core/src/multiarray/dlpack.c
@@ -133,14 +133,15 @@ array_dlpack(PyArrayObject *self,
     }
 
     if (stream != Py_None) {
-        PyErr_SetString(PyExc_RuntimeError, "NumPy only supports "
-                "stream=None.");
+        PyErr_SetString(PyExc_RuntimeError,
+                "NumPy only supports stream=None.");
         return NULL;
     }
 
     if ( !(PyArray_FLAGS(self) & NPY_ARRAY_WRITEABLE)) {
-        PyErr_SetString(PyExc_TypeError, "NumPy currently only supports "
-                "dlpack for writeable arrays");
+        PyErr_SetString(PyExc_BufferError,
+            "Cannot export readonly array since signalling readonly "
+            "is unsupported by DLPack.");
         return NULL;
     }
 
@@ -152,7 +153,7 @@ array_dlpack(PyArrayObject *self,
     if (!PyArray_IS_C_CONTIGUOUS(self) && PyArray_SIZE(self) != 1) {
         for (int i = 0; i < ndim; ++i) {
             if (shape[i] != 1 && strides[i] % itemsize != 0) {
-                PyErr_SetString(PyExc_RuntimeError,
+                PyErr_SetString(PyExc_BufferError,
                         "DLPack only supports strides which are a multiple of "
                         "itemsize.");
                 return NULL;
@@ -164,8 +165,8 @@ array_dlpack(PyArrayObject *self,
     PyArray_Descr *dtype = PyArray_DESCR(self);
 
     if (PyDataType_ISBYTESWAPPED(dtype)) {
-        PyErr_SetString(PyExc_TypeError, "DLPack only supports native "
-                    "byte swapping.");
+        PyErr_SetString(PyExc_BufferError,
+                "DLPack only supports native byte order.");
             return NULL;
     }
 
@@ -182,8 +183,9 @@ array_dlpack(PyArrayObject *self,
         // We can't be sure that the dtype is
         // IEEE or padded.
         if (itemsize > 8) {
-            PyErr_SetString(PyExc_TypeError, "DLPack only supports IEEE "
-                    "floating point types without padding.");
+            PyErr_SetString(PyExc_BufferError,
+                    "DLPack only supports IEEE floating point types "
+                    "without padding (longdouble typically is not IEEE).");
             return NULL;
         }
         managed_dtype.code = kDLFloat;
@@ -192,16 +194,17 @@ array_dlpack(PyArrayObject *self,
         // We can't be sure that the dtype is
         // IEEE or padded.
         if (itemsize > 16) {
-            PyErr_SetString(PyExc_TypeError, "DLPack only supports IEEE "
-                    "complex point types without padding.");
+            PyErr_SetString(PyExc_BufferError,
+                    "DLPack only supports IEEE floating point types "
+                    "without padding (longdouble typically is not IEEE).");
             return NULL;
         }
         managed_dtype.code = kDLComplex;
     }
     else {
-        PyErr_SetString(PyExc_TypeError,
-                        "DLPack only supports signed/unsigned integers, float "
-                        "and complex dtypes.");
+        PyErr_SetString(PyExc_BufferError,
+                "DLPack only supports signed/unsigned integers, float "
+                "and complex dtypes.");
         return NULL;
     }
 
diff --git a/numpy/core/tests/test_dlpack.py b/numpy/core/tests/test_dlpack.py
index 717210b54..278bdd12d 100644
--- a/numpy/core/tests/test_dlpack.py
+++ b/numpy/core/tests/test_dlpack.py
@@ -26,7 +26,7 @@ class TestDLPack:
         y = np.zeros((5,), dtype=dt)
         z = y['int']
 
-        with pytest.raises(RuntimeError):
+        with pytest.raises(BufferError):
             np.from_dlpack(z)
 
     @pytest.mark.skipif(IS_PYPY, reason="PyPy can't get refcounts.")
@@ -53,14 +53,14 @@ class TestDLPack:
     def test_invalid_dtype(self):
         x = np.asarray(np.datetime64('2021-05-27'))
 
-        with pytest.raises(TypeError):
+        with pytest.raises(BufferError):
             np.from_dlpack(x)
 
     def test_invalid_byte_swapping(self):
         dt = np.dtype('=i8').newbyteorder()
         x = np.arange(5, dtype=dt)
 
-        with pytest.raises(TypeError):
+        with pytest.raises(BufferError):
             np.from_dlpack(x)
 
     def test_non_contiguous(self):
@@ -100,7 +100,7 @@ class TestDLPack:
         x = np.arange(5)
         _ = x.__dlpack__()
         raise RuntimeError
-    
+
     def test_dlpack_destructor_exception(self):
         with pytest.raises(RuntimeError):
             self.dlpack_deleter_exception()
@@ -108,7 +108,7 @@ class TestDLPack:
     def test_readonly(self):
         x = np.arange(5)
         x.flags.writeable = False
-        with pytest.raises(TypeError):
+        with pytest.raises(BufferError):
             x.__dlpack__()
 
     def test_ndim0(self):