1 files changed, 113 insertions, 2 deletions

diff --git a/numpy/core/src/umathmodule.c.src b/numpy/core/src/umathmodule.c.src
index d2b4b9c8a..c8c897275 100644
--- a/numpy/core/src/umathmodule.c.src
+++ b/numpy/core/src/umathmodule.c.src
@@ -17,6 +17,8 @@
  */
 #define _UMATHMODULE
 
+#define PY_ARRAY_UNIQUE_SYMBOL _npy_umathmodule_ARRAY_API
+
 #include "Python.h"
 #include "numpy/noprefix.h"
 #include "numpy/ufuncobject.h"
@@ -31,11 +33,120 @@
  *****************************************************************************
  */
 #include "umath_funcs.inc"
-#include "umath_loops.inc"
-#include "umath_ufunc_object.inc"
+#include "umath_loops.h"
+#include "umath_ufunc_object.h"
 #include "__umath_generated.c"
 #include "__ufunc_api.c"
 
+static PyUFuncGenericFunction pyfunc_functions[] = {PyUFunc_On_Om};
+
+static char
+doc_frompyfunc[] = "frompyfunc(func, nin, nout) take an arbitrary python\n"   \
+                   "function that takes nin objects as input and returns\n"   \
+                   "nout objects and return a universal function (ufunc).\n"  \
+                   "This ufunc always returns PyObject arrays\n";
+
+static PyObject *
+ufunc_frompyfunc(PyObject *NPY_UNUSED(dummy), PyObject *args, PyObject *NPY_UNUSED(kwds)) {
+    /* Keywords are ignored for now */
+
+    PyObject *function, *pyname = NULL;
+    int nin, nout, i;
+    PyUFunc_PyFuncData *fdata;
+    PyUFuncObject *self;
+    char *fname, *str;
+    Py_ssize_t fname_len = -1;
+    int offset[2];
+
+    if (!PyArg_ParseTuple(args, "Oii", &function, &nin, &nout)) {
+        return NULL;
+    }
+    if (!PyCallable_Check(function)) {
+        PyErr_SetString(PyExc_TypeError, "function must be callable");
+        return NULL;
+    }
+    self = _pya_malloc(sizeof(PyUFuncObject));
+    if (self == NULL) {
+        return NULL;
+    }
+    PyObject_Init((PyObject *)self, &PyUFunc_Type);
+
+    self->userloops = NULL;
+    self->nin = nin;
+    self->nout = nout;
+    self->nargs = nin + nout;
+    self->identity = PyUFunc_None;
+    self->functions = pyfunc_functions;
+    self->ntypes = 1;
+    self->check_return = 0;
+
+    /* generalized ufunc */
+    self->core_enabled = 0;
+    self->core_num_dim_ix = 0;
+    self->core_num_dims = NULL;
+    self->core_dim_ixs = NULL;
+    self->core_offsets = NULL;
+    self->core_signature = NULL;
+
+    pyname = PyObject_GetAttrString(function, "__name__");
+    if (pyname) {
+        (void) PyString_AsStringAndSize(pyname, &fname, &fname_len);
+    }
+    if (PyErr_Occurred()) {
+        fname = "?";
+        fname_len = 1;
+        PyErr_Clear();
+    }
+    Py_XDECREF(pyname);
+
+    /*
+     * self->ptr holds a pointer for enough memory for
+     * self->data[0] (fdata)
+     * self->data
+     * self->name
+     * self->types
+     *
+     * To be safest, all of these need their memory aligned on void * pointers
+     * Therefore, we may need to allocate extra space.
+     */
+    offset[0] = sizeof(PyUFunc_PyFuncData);
+    i = (sizeof(PyUFunc_PyFuncData) % sizeof(void *));
+    if (i) {
+        offset[0] += (sizeof(void *) - i);
+    }
+    offset[1] = self->nargs;
+    i = (self->nargs % sizeof(void *));
+    if (i) {
+        offset[1] += (sizeof(void *)-i);
+    }
+    self->ptr = _pya_malloc(offset[0] + offset[1] + sizeof(void *) +
+                            (fname_len + 14));
+    if (self->ptr == NULL) {
+        return PyErr_NoMemory();
+    }
+    Py_INCREF(function);
+    self->obj = function;
+    fdata = (PyUFunc_PyFuncData *)(self->ptr);
+    fdata->nin = nin;
+    fdata->nout = nout;
+    fdata->callable = function;
+
+    self->data = (void **)(((char *)self->ptr) + offset[0]);
+    self->data[0] = (void *)fdata;
+    self->types = (char *)self->data + sizeof(void *);
+    for (i = 0; i < self->nargs; i++) {
+        self->types[i] = PyArray_OBJECT;
+    }
+    str = self->types + offset[1];
+    memcpy(str, fname, fname_len);
+    memcpy(str+fname_len, " (vectorized)", 14);
+    self->name = str;
+
+    /* Do a better job someday */
+    self->doc = "dynamic ufunc based on a python function";
+
+    return (PyObject *)self;
+}
 
 /*
  *****************************************************************************