Merge pull request #11480 from mhvk/ufunc-override-move-code-closer-to-use

MAINT: move ufunc override code to umath and multiarray as much as possible.

2 files changed, 34 insertions, 181 deletions

diff --git a/numpy/core/src/common/ufunc_override.c b/numpy/core/src/common/ufunc_override.c
index 33b54c665..b67422132 100644
--- a/numpy/core/src/common/ufunc_override.c
+++ b/numpy/core/src/common/ufunc_override.c
@@ -1,10 +1,9 @@
 #define NPY_NO_DEPRECATED_API NPY_API_VERSION
-#define NO_IMPORT_ARRAY
+#define _MULTIARRAYMODULE
 
 #include "npy_pycompat.h"
 #include "get_attr_string.h"
 #include "npy_import.h"
-
 #include "ufunc_override.h"
 
 /*
@@ -12,45 +11,39 @@
  * is not the default, i.e., the object is not an ndarray, and its
  * __array_ufunc__ is not the same as that of ndarray.
  *
- * Returns a new reference, the value of type(obj).__array_ufunc__
- *
- * If the __array_ufunc__ matches that of ndarray, or does not exist, return
- * NULL.
- *
- * Note that since this module is used with both multiarray and umath, we do
- * not have access to PyArray_Type and therewith neither to PyArray_CheckExact
- * nor to the default __array_ufunc__ method, so instead we import locally.
- * TODO: Can this really not be done more smartly?
+ * Returns a new reference, the value of type(obj).__array_ufunc__ if it
+ * exists and is different from that of ndarray, and NULL otherwise.
  */
 NPY_NO_EXPORT PyObject *
-get_non_default_array_ufunc(PyObject *obj)
+PyUFuncOverride_GetNonDefaultArrayUfunc(PyObject *obj)
 {
-    static PyObject *ndarray = NULL;
     static PyObject *ndarray_array_ufunc = NULL;
     PyObject *cls_array_ufunc;
 
-    /* on first entry, import and cache ndarray and its __array_ufunc__ */
-    if (ndarray == NULL) {
-        npy_cache_import("numpy.core.multiarray", "ndarray", &ndarray);
-        ndarray_array_ufunc = PyObject_GetAttrString(ndarray,
+    /* On first entry, cache ndarray's __array_ufunc__ */
+    if (ndarray_array_ufunc == NULL) {
+        ndarray_array_ufunc = PyObject_GetAttrString((PyObject *)&PyArray_Type,
                                                      "__array_ufunc__");
     }
 
     /* Fast return for ndarray */
-    if ((PyObject *)Py_TYPE(obj) == ndarray) {
+    if (PyArray_CheckExact(obj)) {
         return NULL;
     }
-    /* does the class define __array_ufunc__? */
+    /*
+     * Does the class define __array_ufunc__? (Note that LookupSpecial has fast
+     * return for basic python types, so no need to worry about those here)
+     */
     cls_array_ufunc = PyArray_LookupSpecial(obj, "__array_ufunc__");
     if (cls_array_ufunc == NULL) {
         return NULL;
     }
-    /* is it different from ndarray.__array_ufunc__? */
-    if (cls_array_ufunc != ndarray_array_ufunc) {
-        return cls_array_ufunc;
+    /* Ignore if the same as ndarray.__array_ufunc__ */
+    if (cls_array_ufunc == ndarray_array_ufunc) {
+        Py_DECREF(cls_array_ufunc);
+        return NULL;
     }
-    Py_DECREF(cls_array_ufunc);
-    return NULL;
+    return cls_array_ufunc;
 }
 
 /*
@@ -62,9 +55,9 @@ get_non_default_array_ufunc(PyObject *obj)
  */
 
 NPY_NO_EXPORT int
-has_non_default_array_ufunc(PyObject * obj)
+PyUFunc_HasOverride(PyObject * obj)
 {
-    PyObject *method = get_non_default_array_ufunc(obj);
+    PyObject *method = PyUFuncOverride_GetNonDefaultArrayUfunc(obj);
     if (method) {
         Py_DECREF(method);
         return 1;
@@ -80,17 +73,17 @@ has_non_default_array_ufunc(PyObject * obj)
  * The out argument itself is returned in out_kwd_obj, and the outputs
  * in the out_obj array (all as borrowed references).
  *
- * Returns -1 if kwds is not a dict, 0 if no outputs found.
+ * Returns 0 if no outputs found, -1 if kwds is not a dict (with an error set).
  */
-static int
-get_out_objects(PyObject *kwds, PyObject **out_kwd_obj, PyObject ***out_objs)
+NPY_NO_EXPORT int
+PyUFuncOverride_GetOutObjects(PyObject *kwds, PyObject **out_kwd_obj, PyObject ***out_objs)
 {
     if (kwds == NULL) {
         return 0;
     }
     if (!PyDict_CheckExact(kwds)) {
         PyErr_SetString(PyExc_TypeError,
-                        "Internal Numpy error: call to PyUFunc_WithOverride "
+                        "Internal Numpy error: call to PyUFuncOverride_GetOutObjects "
                         "with non-dict kwds");
         return -1;
     }
@@ -108,134 +101,3 @@ get_out_objects(PyObject *kwds, PyObject **out_kwd_obj, PyObject ***out_objs)
         return 1;
     }
 }
-
-/*
- * For each positional argument and each argument in a possible "out"
- * keyword, look for overrides of the standard ufunc behaviour, i.e.,
- * non-default __array_ufunc__ methods.
- *
- * Returns the number of overrides, setting corresponding objects
- * in PyObject array ``with_override`` and the corresponding
- * __array_ufunc__ methods in ``methods`` (both using new references).
- *
- * Only the first override for a given class is returned.
- *
- * returns -1 on failure.
- */
-NPY_NO_EXPORT int
-PyUFunc_WithOverride(PyObject *args, PyObject *kwds,
-                     PyObject **with_override, PyObject **methods)
-{
-    int i;
-    int num_override_args = 0;
-    int narg, nout = 0;
-    PyObject *out_kwd_obj;
-    PyObject **arg_objs, **out_objs;
-
-    narg = PyTuple_Size(args);
-    if (narg < 0) {
-        return -1;
-    }
-    arg_objs = PySequence_Fast_ITEMS(args);
-
-    nout = get_out_objects(kwds, &out_kwd_obj, &out_objs);
-    if (nout < 0) {
-        return -1;
-    }
-
-    for (i = 0; i < narg + nout; ++i) {
-        PyObject *obj;
-        int j;
-        int new_class = 1;
-
-        if (i < narg) {
-            obj = arg_objs[i];
-        }
-        else {
-            obj = out_objs[i - narg];
-        }
-        /*
-         * Have we seen this class before?  If so, ignore.
-         */
-        for (j = 0; j < num_override_args; j++) {
-            new_class = (Py_TYPE(obj) != Py_TYPE(with_override[j]));
-            if (!new_class) {
-                break;
-            }
-        }
-        if (new_class) {
-            /*
-             * Now see if the object provides an __array_ufunc__. However, we should
-             * ignore the base ndarray.__ufunc__, so we skip any ndarray as well as
-             * any ndarray subclass instances that did not override __array_ufunc__.
-             */
-            PyObject *method = get_non_default_array_ufunc(obj);
-            if (method == NULL) {
-                continue;
-            }
-            if (method == Py_None) {
-                PyErr_Format(PyExc_TypeError,
-                             "operand '%.200s' does not support ufuncs "
-                             "(__array_ufunc__=None)",
-                             obj->ob_type->tp_name);
-                Py_DECREF(method);
-                goto fail;
-            }
-            Py_INCREF(obj);
-            with_override[num_override_args] = obj;
-            methods[num_override_args] = method;
-            ++num_override_args;
-        }
-    }
-    return num_override_args;
-
-fail:
-    for (i = 0; i < num_override_args; i++) {
-        Py_DECREF(with_override[i]);
-        Py_DECREF(methods[i]);
-    }
-    return -1;
-}
-
-/*
- * Check whether any of a set of input and output args have a non-default
- * __array_ufunc__ method. Return 1 if so, 0 if not.
- *
- * This function primarily exists to help ndarray.__array_ufunc__ determine
- * whether it can support a ufunc (which is the case only if none of the
- * operands have an override).  Thus, unlike in PyUFunc_CheckOverride, the
- * actual overrides are not needed and one can stop looking once one is found.
- *
- * TODO: move this function and has_non_default_array_ufunc closer to ndarray.
- */
-NPY_NO_EXPORT int
-PyUFunc_HasOverride(PyObject *args, PyObject *kwds)
-{
-    int i;
-    int nin, nout;
-    PyObject *out_kwd_obj;
-    PyObject **in_objs, **out_objs;
-
-    /* check inputs */
-    nin = PyTuple_Size(args);
-    if (nin < 0) {
-        return -1;
-    }
-    in_objs = PySequence_Fast_ITEMS(args);
-    for (i = 0; i < nin; ++i) {
-        if (has_non_default_array_ufunc(in_objs[i])) {
-            return 1;
-        }
-    }
-    /* check outputs, if any */
-    nout = get_out_objects(kwds, &out_kwd_obj, &out_objs);
-    if (nout < 0) {
-        return -1;
-    }
-    for (i = 0; i < nout; i++) {
-        if (has_non_default_array_ufunc(out_objs[i])) {
-            return 1;
-        }
-    }
-    return 0;
-}
diff --git a/numpy/core/src/common/ufunc_override.h b/numpy/core/src/common/ufunc_override.h
index 5b269d270..cc39166b3 100644
--- a/numpy/core/src/common/ufunc_override.h
+++ b/numpy/core/src/common/ufunc_override.h
@@ -8,18 +8,11 @@
  * is not the default, i.e., the object is not an ndarray, and its
  * __array_ufunc__ is not the same as that of ndarray.
  *
- * Returns a new reference, the value of type(obj).__array_ufunc__
- *
- * If the __array_ufunc__ matches that of ndarray, or does not exist, return
- * NULL.
- *
- * Note that since this module is used with both multiarray and umath, we do
- * not have access to PyArray_Type and therewith neither to PyArray_CheckExact
- * nor to the default __array_ufunc__ method, so instead we import locally.
- * TODO: Can this really not be done more smartly?
+ * Returns a new reference, the value of type(obj).__array_ufunc__ if it
+ * exists and is different from that of ndarray, and NULL otherwise.
  */
 NPY_NO_EXPORT PyObject *
-get_non_default_array_ufunc(PyObject *obj);
+PyUFuncOverride_GetNonDefaultArrayUfunc(PyObject *obj);
 
 /*
  * Check whether an object has __array_ufunc__ defined on its class and it
@@ -29,18 +22,16 @@ get_non_default_array_ufunc(PyObject *obj);
  * Returns 1 if this is the case, 0 if not.
  */
 NPY_NO_EXPORT int
-has_non_default_array_ufunc(PyObject * obj);
+PyUFunc_HasOverride(PyObject *obj);
 
 /*
- * Check whether a set of input and output args have a non-default
- *  `__array_ufunc__` method. Returns the number of overrides, setting
- * corresponding objects in PyObject array with_override (if not NULL).
- * returns -1 on failure.
+ * Get possible out argument from kwds, and returns the number of outputs
+ * contained within it: if a tuple, the number of elements in it, 1 otherwise.
+ * The out argument itself is returned in out_kwd_obj, and the outputs
+ * in the out_obj array (all as borrowed references).
+ *
+ * Returns 0 if no outputs found, -1 if kwds is not a dict (with an error set).
  */
 NPY_NO_EXPORT int
-PyUFunc_WithOverride(PyObject *args, PyObject *kwds,
-                     PyObject **with_override, PyObject **methods);
-
-NPY_NO_EXPORT int
-PyUFunc_HasOverride(PyObject *args, PyObject *kwds);
+PyUFuncOverride_GetOutObjects(PyObject *kwds, PyObject **out_kwd_obj, PyObject ***out_objs);
 #endif