Merge pull request numpy#26985 from seberg/issue-26756

BUG: Add object cast to avoid warning with limited API

Author: ngoldbaum

numpy/_core/include/numpy/dtype_api.h

@@ -449,7 +449,7 @@ typedef PyArray_DTypeMeta *(PyArrayDTypeMeta_CommonDType)(
 
 static inline PyArray_DTypeMeta *
 NPY_DT_NewRef(PyArray_DTypeMeta *o) {
-    Py_INCREF(o);
+    Py_INCREF((PyObject *)o);
     return o;
 }
 

numpy/_core/tests/examples/limited_api/limited_api_latest.c

@@ -0,0 +1,19 @@
+#if Py_LIMITED_API != PY_VERSION_HEX & 0xffff0000
+    # error "Py_LIMITED_API not defined to Python major+minor version"
+#endif
+
+#include <Python.h>
+#include <numpy/arrayobject.h>
+#include <numpy/ufuncobject.h>
+
+static PyModuleDef moduledef = {
+    .m_base = PyModuleDef_HEAD_INIT,
+    .m_name = "limited_api_latest"
+};
+
+PyMODINIT_FUNC PyInit_limited_api_latest(void)
+{
+    import_array();
+    import_umath();
+    return PyModule_Create(&moduledef);
+}

numpy/_core/tests/examples/limited_api/meson.build

@@ -34,6 +34,16 @@ py.extension_module(
     limited_api: '3.6',
 )
 
+py.extension_module(
+    'limited_api_latest',
+    'limited_api_latest.c',
+    c_args: [
+      '-DNPY_NO_DEPRECATED_API=NPY_1_21_API_VERSION',
+    ],
+    include_directories: [npy_include_path],
+    limited_api: py.language_version(),
+)
+
 py.extension_module(
     'limited_api2',
     'limited_api2.pyx',

numpy/_core/tests/test_limited_api.py

@@ -47,16 +47,18 @@ def install_temp(tmpdir_factory):
         pytest.skip("No usable 'meson' found")
     if sys.platform == "win32":
         subprocess.check_call(["meson", "setup",
+                               "--werror",
                                "--buildtype=release",
                                "--vsenv", str(srcdir)],
                               cwd=build_dir,
                               )
     else:
-        subprocess.check_call(["meson", "setup", str(srcdir)],
+        subprocess.check_call(["meson", "setup", "--werror", str(srcdir)],
                               cwd=build_dir
                               )
     try:
-        subprocess.check_call(["meson", "compile", "-vv"], cwd=build_dir)
+        subprocess.check_call(
+            ["meson", "compile", "-vv"], cwd=build_dir)
     except subprocess.CalledProcessError as p:
         print(f"{p.stdout=}")
         print(f"{p.stderr=}")
@@ -84,5 +86,6 @@ def test_limited_api(install_temp):
     and building a cython extension with the limited API
     """
 
-    import limited_api1
-    import limited_api2
+    import limited_api1  # Earliest (3.6)
+    import limited_api_latest  # Latest version (current Python)
+    import limited_api2  # cython