Function PyArray_MapIterCheckIndices

numpy/core/src/multiarray/mapping.c:2558–2696

* Check whether the fancy indices are out of bounds. * Returns 0 on success and -1 on failure. * (Gets operands from the outer iterator, but iterates them independently) */

 * (Gets operands from the outer iterator, but iterates them independently)
 */
NPY_NO_EXPORT int
PyArray_MapIterCheckIndices(PyArrayMapIterObject *mit)
{
    PyArrayObject *op;
    NpyIter *op_iter;
    NpyIter_IterNextFunc *op_iternext;
    npy_intp outer_dim, indval;
    int outer_axis;
    npy_intp itersize, *iterstride;
    char **iterptr;
    PyArray_Descr *intp_type;
    int i;
    NPY_BEGIN_THREADS_DEF;

    if (NpyIter_GetIterSize(mit->outer) == 0) {
        /*
         * When the outer iteration is empty, the indices broadcast to an
         * empty shape, and in this case we do not check if there are out
         * of bounds indices.
         * The code below does use the indices without broadcasting since
         * broadcasting only repeats values.
         */
        return 0;
    }

    intp_type = PyArray_DescrFromType(NPY_INTP);

    NPY_BEGIN_THREADS;

    for (i=0; i < mit->numiter; i++) {
        op = NpyIter_GetOperandArray(mit->outer)[i];

        outer_dim = mit->fancy_dims[i];
        outer_axis = mit->iteraxes[i];

        /* See if it is possible to just trivially iterate the array */
        if (PyArray_TRIVIALLY_ITERABLE(op) &&
                /* Check if the type is equivalent to INTP */
                PyArray_ITEMSIZE(op) == sizeof(npy_intp) &&
                PyArray_DESCR(op)->kind == 'i' &&
                IsUintAligned(op) &&
                PyDataType_ISNOTSWAPPED(PyArray_DESCR(op))) {
            char *data;
            npy_intp stride;
            /* release GIL if it was taken by nditer below */
            if (_save == NULL) {
                NPY_BEGIN_THREADS;
            }

            PyArray_PREPARE_TRIVIAL_ITERATION(op, itersize, data, stride);

            while (itersize--) {
                indval = *((npy_intp*)data);
                if (check_and_adjust_index(&indval,
                                           outer_dim, outer_axis, _save) < 0) {
                    Py_DECREF(intp_type);
                    goto indexing_error;
                }