Merge pull request #9784 from eric-wieser/fix-void-recursion

BUG: remove voidtype-repr recursion in scalartypes.c/arrayprint.py

4 files changed, 71 insertions, 41 deletions

diff --git a/doc/release/1.14.0-notes.rst b/doc/release/1.14.0-notes.rst
index c9f1cec76..3224b80fd 100644
--- a/doc/release/1.14.0-notes.rst
+++ b/doc/release/1.14.0-notes.rst
@@ -256,17 +256,24 @@ Changes
 0d arrays now use the array2string formatters to print their elements, like
 other arrays. The ``style`` argument of ``array2string`` is now non-functional.
 
+User-defined types now need to implement ``__str__`` and ``__repr__``
+---------------------------------------------------------------------
+Previously, user-defined types could fall back to a default implementation of
+``__str__`` and ``__repr__`` implemented in numpy, but this has now been
+removed. Now user-defined types will fall back to the python default
+``object.__str__`` and ``object.__repr__``.
+
 ``np.linalg.matrix_rank`` is more efficient for hermitian matrices
 ------------------------------------------------------------------
 The keyword argument ``hermitian`` was added to toggle between standard
 SVD-based matrix rank calculation and the more efficient eigenvalue-based
 method for symmetric/hermitian matrices.
 
-Integer scalars are now unaffected by ``np.set_string_function``
-----------------------------------------------------------------
-Previously the str/repr of integer scalars could be controlled by
-``np.set_string_function``, unlike most other numpy scalars. This is no longer
-the case.
+Integer and Void scalars are now unaffected by ``np.set_string_function``
+-------------------------------------------------------------------------
+Previously the ``str`` and ``repr`` of integer and void scalars could be
+controlled by ``np.set_string_function``, unlike most other numpy scalars. This
+is no longer the case.
 
 Multiple-field indexing/assignment of structured arrays
 -------------------------------------------------------
diff --git a/numpy/core/arrayprint.py b/numpy/core/arrayprint.py
index e0da9f81e..e1df556ef 100644
--- a/numpy/core/arrayprint.py
+++ b/numpy/core/arrayprint.py
@@ -309,13 +309,7 @@ def _get_format_function(data, **options):
     """
     dtype_ = data.dtype
     if dtype_.fields is not None:
-        format_functions = []
-        for field_name in dtype_.names:
-            format_function = _get_format_function(data[field_name], **options)
-            if dtype_[field_name].shape != ():
-                format_function = SubArrayFormat(format_function)
-            format_functions.append(format_function)
-        return StructureFormat(format_functions)
+        return StructureFormat.from_data(data, **options)
 
     dtypeobj = dtype_.type
     formatdict = _get_formatdict(data, **options)
@@ -873,6 +867,20 @@ class StructureFormat(object):
         self.format_functions = format_functions
         self.num_fields = len(format_functions)
 
+    @classmethod
+    def from_data(cls, data, **options):
+        """
+        This is a second way to initialize StructureFormat, using the raw data
+        as input. Added to avoid changing the signature of __init__.
+        """
+        format_functions = []
+        for field_name in data.dtype.names:
+            format_function = _get_format_function(data[field_name], **options)
+            if data.dtype[field_name].shape != ():
+                format_function = SubArrayFormat(format_function)
+            format_functions.append(format_function)
+        return cls(format_functions)
+
     def __call__(self, x):
         s = "("
         for field, format_function in zip(x, self.format_functions):
@@ -880,6 +888,15 @@ class StructureFormat(object):
         return (s[:-2] if 1 < self.num_fields else s[:-1]) + ")"
 
 
+def _void_scalar_repr(x):
+    """
+    Implements the repr for structured-void scalars. It is called from the
+    scalartypes.c.src code, and is placed here because it uses the elementwise
+    formatters defined above.
+    """
+    return StructureFormat.from_data(array(x), **_format_options)(x)
+
+
 _typelessdata = [int_, float_, complex_]
 if issubclass(intc, int):
     _typelessdata.append(intc)
diff --git a/numpy/core/src/multiarray/scalartypes.c.src b/numpy/core/src/multiarray/scalartypes.c.src
index 7a6ed6a86..c92d835ed 100644
--- a/numpy/core/src/multiarray/scalartypes.c.src
+++ b/numpy/core/src/multiarray/scalartypes.c.src
@@ -25,6 +25,7 @@
 #include "_datetime.h"
 #include "datetime_strings.h"
 #include "alloc.h"
+#include "npy_import.h"
 
 #include <stdlib.h>
 
@@ -339,33 +340,6 @@ gentype_nonzero_number(PyObject *m1)
 }
 
 static PyObject *
-gentype_str(PyObject *self)
-{
-    PyObject *arr, *ret = NULL;
-
-    arr = PyArray_FromScalar(self, NULL);
-    if (arr != NULL) {
-        ret = PyObject_Str((PyObject *)arr);
-        Py_DECREF(arr);
-    }
-    return ret;
-}
-
-static PyObject *
-gentype_repr(PyObject *self)
-{
-    PyObject *arr, *ret = NULL;
-
-    arr = PyArray_FromScalar(self, NULL);
-    if (arr != NULL) {
-        /* XXX: Why are we using str here? */
-        ret = PyObject_Str((PyObject *)arr);
-        Py_DECREF(arr);
-    }
-    return ret;
-}
-
-static PyObject *
 genint_type_str(PyObject *self)
 {
     PyObject  *item, *item_str;
@@ -634,6 +608,34 @@ static PyObject *
 /**end repeat**/
 
 static PyObject *
+voidtype_str(PyObject *self)
+{
+    if (PyDataType_HASFIELDS(((PyVoidScalarObject*)self)->descr)) {
+        static PyObject *reprfunc = NULL;
+
+        npy_cache_import("numpy.core.arrayprint",
+                         "_void_scalar_repr", &reprfunc);
+        if (reprfunc == NULL) {
+            return NULL;
+        }
+
+        return PyObject_CallFunction(reprfunc, "O", self);
+    }
+    else {
+        PyObject *item, *item_str;
+
+        item = gentype_generic_method(self, NULL, NULL, "item");
+        if (item == NULL) {
+            return NULL;
+        }
+
+        item_str = PyObject_Str(item);
+        Py_DECREF(item);
+        return item_str;
+    }
+}
+
+static PyObject *
 datetimetype_repr(PyObject *self)
 {
     PyDatetimeScalarObject *scal;
@@ -4073,8 +4075,6 @@ initialize_numeric_types(void)
     PyGenericArrType_Type.tp_new = NULL;
     PyGenericArrType_Type.tp_alloc = gentype_alloc;
     PyGenericArrType_Type.tp_free = (freefunc)gentype_free;
-    PyGenericArrType_Type.tp_repr = gentype_repr;
-    PyGenericArrType_Type.tp_str = gentype_str;
     PyGenericArrType_Type.tp_richcompare = gentype_richcompare;
 
     PyBoolArrType_Type.tp_as_number = &bool_arrtype_as_number;
@@ -4122,6 +4122,8 @@ initialize_numeric_types(void)
     PyVoidArrType_Type.tp_getset = voidtype_getsets;
     PyVoidArrType_Type.tp_as_mapping = &voidtype_as_mapping;
     PyVoidArrType_Type.tp_as_sequence = &voidtype_as_sequence;
+    PyVoidArrType_Type.tp_repr = voidtype_str;
+    PyVoidArrType_Type.tp_str = voidtype_str;
 
     PyIntegerArrType_Type.tp_getset = inttype_getsets;
 
diff --git a/numpy/core/tests/test_arrayprint.py b/numpy/core/tests/test_arrayprint.py
index b03229447..26faabfb8 100644
--- a/numpy/core/tests/test_arrayprint.py
+++ b/numpy/core/tests/test_arrayprint.py
@@ -60,6 +60,10 @@ class TestArrayRepr(object):
         assert_equal(repr(arr1d),
             'array([list([1, 2]), list([3])], dtype=object)')
 
+    def test_void_scalar_recursion(self):
+        # gh-9345
+        repr(np.void(b'test'))  # RecursionError ?
+
 
 class TestComplexArray(object):
     def test_str(self):