MAINT: Rename allow_copy to never_copy in never-copy machinery

The first name was `do_copy`, which was confusing because it sounds
like a copy is forced (opposite is the case!)  `allow_copy` would
have been better, but corrects it into the wrong direction.
`never_copy` is correct, and aligns with the Python side names

Author: seberg

numpy/core/src/multiarray/array_coercion.c

@@ -858,7 +858,7 @@ PyArray_AdaptDescriptorToArray(PyArrayObject *arr, PyObject *dtype)
  *        (Initially it is a pointer to the user-provided head pointer).
  * @param fixed_DType User provided fixed DType class
  * @param flags Discovery flags (reporting and behaviour flags, see def.)
- * @param allow_copy Specifies if a copy is allowed during array creation.
+ * @param never_copy Specifies if a copy is allowed during array creation.
  * @return The updated number of maximum dimensions (i.e. scalars will set
  *         this to the current dimensions).
  */
@@ -868,7 +868,7 @@ PyArray_DiscoverDTypeAndShape_Recursive(
         npy_intp out_shape[NPY_MAXDIMS],
         coercion_cache_obj ***coercion_cache_tail_ptr,
         PyArray_DTypeMeta *fixed_DType, enum _dtype_discovery_flags *flags,
-        int allow_copy)
+        int never_copy)
 {
     PyArrayObject *arr = NULL;
     PyObject *seq;
@@ -926,7 +926,7 @@ PyArray_DiscoverDTypeAndShape_Recursive(
             requested_descr = *out_descr;
         }
         arr = (PyArrayObject *)_array_from_array_like(obj,
-                requested_descr, 0, NULL, allow_copy);
+                requested_descr, 0, NULL, never_copy);
         if (arr == NULL) {
             return -1;
         }
@@ -1120,7 +1120,7 @@ PyArray_DiscoverDTypeAndShape_Recursive(
         max_dims = PyArray_DiscoverDTypeAndShape_Recursive(
                 objects[i], curr_dims + 1, max_dims,
                 out_descr, out_shape, coercion_cache_tail_ptr, fixed_DType,
-                flags, allow_copy);
+                flags, never_copy);
 
         if (max_dims < 0) {
             return -1;
@@ -1160,7 +1160,7 @@ PyArray_DiscoverDTypeAndShape_Recursive(
  *        The result may be unchanged (remain NULL) when converting a
  *        sequence with no elements. In this case it is callers responsibility
  *        to choose a default.
- * @param allow_copy Specifies if a copy is allowed during array creation.
+ * @param never_copy Specifies that a copy is not allowed.
  * @return dimensions of the discovered object or -1 on error.
  *         WARNING: If (and only if) the output is a single array, the ndim
  *         returned _can_ exceed the maximum allowed number of dimensions.
@@ -1173,7 +1173,7 @@ PyArray_DiscoverDTypeAndShape(
         npy_intp out_shape[NPY_MAXDIMS],
         coercion_cache_obj **coercion_cache,
         PyArray_DTypeMeta *fixed_DType, PyArray_Descr *requested_descr,
-        PyArray_Descr **out_descr, int allow_copy)
+        PyArray_Descr **out_descr, int never_copy)
 {
     coercion_cache_obj **coercion_cache_head = coercion_cache;
     *coercion_cache = NULL;
@@ -1218,7 +1218,7 @@ PyArray_DiscoverDTypeAndShape(
 
     int ndim = PyArray_DiscoverDTypeAndShape_Recursive(
             obj, 0, max_dims, out_descr, out_shape, &coercion_cache,
-            fixed_DType, &flags, allow_copy);
+            fixed_DType, &flags, never_copy);
     if (ndim < 0) {
         goto fail;
     }

numpy/core/src/multiarray/array_coercion.h

@@ -31,7 +31,7 @@ PyArray_DiscoverDTypeAndShape(
         npy_intp out_shape[NPY_MAXDIMS],
         coercion_cache_obj **coercion_cache,
         PyArray_DTypeMeta *fixed_DType, PyArray_Descr *requested_descr,
-        PyArray_Descr **out_descr, int allow_copy);
+        PyArray_Descr **out_descr, int never_copy);
 
 NPY_NO_EXPORT int
 PyArray_ExtractDTypeAndDescriptor(PyObject *dtype,

numpy/core/src/multiarray/ctors.c

@@ -1284,7 +1284,7 @@ _array_from_buffer_3118(PyObject *memoryview)
  *                       DType may be used, but is not enforced.
  * @param writeable whether the result must be writeable.
  * @param context Unused parameter, must be NULL (should be removed later).
- * @param allow_copy Specifies if a copy is allowed during array creation.
+ * @param never_copy Specifies that a copy is not allowed.
  *
  * @returns The array object, Py_NotImplemented if op is not array-like,
  *          or NULL with an error set. (A new reference to Py_NotImplemented
@@ -1293,7 +1293,7 @@ _array_from_buffer_3118(PyObject *memoryview)
 NPY_NO_EXPORT PyObject *
 _array_from_array_like(PyObject *op,
         PyArray_Descr *requested_dtype, npy_bool writeable, PyObject *context,
-        int allow_copy) {
+        int never_copy) {
     PyObject* tmp;
 
     /*
@@ -1349,7 +1349,7 @@ _array_from_array_like(PyObject *op,
      *      this should be changed!
      */
     if (!writeable && tmp == Py_NotImplemented) {
-        tmp = PyArray_FromArrayAttr_int(op, requested_dtype, allow_copy);
+        tmp = PyArray_FromArrayAttr_int(op, requested_dtype, never_copy);
         if (tmp == NULL) {
             return NULL;
         }
@@ -2467,7 +2467,7 @@ PyArray_FromInterface(PyObject *origin)
  * @param op The Python object to convert to an array.
  * @param descr The desired `arr.dtype`, passed into the `__array__` call,
  *        as information but is not checked/enforced!
- * @param never_copy Indicator that a copy is not allowed.
+ * @param never_copy Specifies that a copy is not allowed.
  *        NOTE: Currently, this means an error is raised instead of calling
  *        `op.__array__()`.  In the future we could call for example call
  *        `op.__array__(never_copy=True)` instead.

numpy/core/src/multiarray/ctors.h

@@ -33,7 +33,7 @@ PyArray_New(
 NPY_NO_EXPORT PyObject *
 _array_from_array_like(PyObject *op,
         PyArray_Descr *requested_dtype, npy_bool writeable, PyObject *context,
-        int allow_copy);
+        int never_copy);
 
 NPY_NO_EXPORT PyObject *
 PyArray_FromAny(PyObject *op, PyArray_Descr *newtype, int min_depth,