Deprecate unused dpnp.config settings

CHANGELOG.md

@@ -62,6 +62,7 @@ This release is compatible with NumPy 2.5.
 ### Deprecated
 
 * Deprecated setting the shape via the `shape` attribute of `dpnp.ndarray` and `dpnp.tensor.usm_ndarray`. Use `dpnp.reshape`/`dpnp.tensor.reshape` (or the `reshape` method) instead [#2967](https://github.com/IntelPython/dpnp/pull/2967)
+* Deprecated `dpnp.config.__DPNP_QUEUE_GPU__`, `dpnp.config.__DPNP_OUTPUT_NUMPY__` and `dpnp.config.__DPNP_OUTPUT_DPCTL_DEFAULT_SHARED__`, which have no effect; reading them now emits a `DeprecationWarning` [#3107](https://github.com/IntelPython/dpnp/pull/3107)
 
 ### Removed
 

dpnp/config.py

@@ -28,32 +28,37 @@
 
 
 import os
+import warnings
 
 __DPNP_ORIGIN__ = int(os.getenv("DPNP_ORIGIN", 0))
 """
 Explicitly use original host Python NumPy
 """
 
-__DPNP_QUEUE_GPU__ = int(os.getenv("DPNP_QUEUE_GPU", 0))
-"""
-Explicitly use GPU for SYCL queue
-"""
-
-__DPNP_OUTPUT_NUMPY__ = int(os.getenv("DPNP_OUTPUT_NUMPY", 0))
-"""
-Explicitly use NumPy.ndarray as return type for creation functions
-"""
-
-__DPNP_OUTPUT_DPCTL_DEFAULT_SHARED__ = int(
-    os.getenv("DPNP_OUTPUT_DPCTL_DEFAULT_SHARED", 0)
-)
-"""
-Explicitly use SYCL shared memory parameter in DPCtl array constructor for creation functions
-"""
-
 __DPNP_RAISE_EXCEPION_ON_NUMPY_FALLBACK__ = int(
     os.getenv("DPNP_RAISE_EXCEPION_ON_NUMPY_FALLBACK", 1)
 )
 """
 Trigger non-implemented exception when DPNP fallbacks on NumPy implementation
 """
+
+# settings that no longer have any effect, kept as deprecated attributes
+_DEPRECATED_SETTINGS = {
+    "__DPNP_QUEUE_GPU__": int(os.getenv("DPNP_QUEUE_GPU", 0)),
+    "__DPNP_OUTPUT_NUMPY__": int(os.getenv("DPNP_OUTPUT_NUMPY", 0)),
+    "__DPNP_OUTPUT_DPCTL_DEFAULT_SHARED__": int(
+        os.getenv("DPNP_OUTPUT_DPCTL_DEFAULT_SHARED", 0)
+    ),
+}
+
+
+def __getattr__(name):
+    if name in _DEPRECATED_SETTINGS:
+        warnings.warn(
+            f"`dpnp.config.{name}` is deprecated, and will be removed in a "
+            "future release. It has no effect.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        return _DEPRECATED_SETTINGS[name]
+    raise AttributeError(f"module {__name__!r} has no attribute {name!r}")

dpnp/tests/test_config.py

@@ -0,0 +1,22 @@
+import pytest
+
+import dpnp
+
+
+class TestDeprecatedSettings:
+    @pytest.mark.parametrize(
+        "name",
+        [
+            "__DPNP_QUEUE_GPU__",
+            "__DPNP_OUTPUT_NUMPY__",
+            "__DPNP_OUTPUT_DPCTL_DEFAULT_SHARED__",
+        ],
+    )
+    def test_warns(self, name):
+        with pytest.warns(DeprecationWarning, match="has no effect"):
+            value = getattr(dpnp.config, name)
+        assert isinstance(value, int)
+
+    def test_unknown_name(self):
+        with pytest.raises(AttributeError, match="has no attribute"):
+            getattr(dpnp.config, "__DPNP_UNKNOWN__")