From 764b6674912542b7b89d6faf0394e10049ed91d0 Mon Sep 17 00:00:00 2001
From: Sebastian Berg <sebastianb@nvidia.com>
Date: Fri, 19 Jul 2024 10:51:23 +0200
Subject: [PATCH] BUG: Add object cast to avoid warning with limited API

To be honest, I think we should just delete this from the public API.
But I thought I'll start with this, since at least in
principle that isn't a bug-release thing to backport.

I am not sure setting warnings to errors is wise (at least for Cython and
MSVC).  OTOH, the Cython module currently truly does nothing except
include the headers (it doesn't even use the NumPy `.pyd` yet).
---
 numpy/_core/include/numpy/dtype_api.h         |  2 +-
 .../examples/limited_api/limited_api_latest.c | 19 +++++++++++++++++++
 .../tests/examples/limited_api/meson.build    | 10 ++++++++++
 numpy/_core/tests/test_limited_api.py         | 11 +++++++----
 4 files changed, 37 insertions(+), 5 deletions(-)
 create mode 100644 numpy/_core/tests/examples/limited_api/limited_api_latest.c

diff --git a/numpy/_core/include/numpy/dtype_api.h b/numpy/_core/include/numpy/dtype_api.h
index c35577fbbcad..9dd3effa3a80 100644
--- a/numpy/_core/include/numpy/dtype_api.h
+++ b/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;
 }
 
diff --git a/numpy/_core/tests/examples/limited_api/limited_api_latest.c b/numpy/_core/tests/examples/limited_api/limited_api_latest.c
new file mode 100644
index 000000000000..13668f2f0ebf
--- /dev/null
+++ b/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);
+}
diff --git a/numpy/_core/tests/examples/limited_api/meson.build b/numpy/_core/tests/examples/limited_api/meson.build
index a6d290304036..65287d8654f5 100644
--- a/numpy/_core/tests/examples/limited_api/meson.build
+++ b/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',
diff --git a/numpy/_core/tests/test_limited_api.py b/numpy/_core/tests/test_limited_api.py
index c1b2cfcbaff9..9273264a867d 100644
--- a/numpy/_core/tests/test_limited_api.py
+++ b/numpy/_core/tests/test_limited_api.py
@@ -40,16 +40,18 @@ 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=}")
@@ -73,5 +75,6 @@ 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