python · vstinner · Oct 14, 2021 · Oct 14, 2021
@@ -565,6 +565,13 @@ Porting to Python 3.11
  ``exit()`` and ``abort()``.
  (Contributed by Victor Stinner in :issue:`45434`.)

+* The ``<Python.h>`` header file no longer includes ``<stdio.h>`` if the
+  ``Py_LIMITED_API`` macro is defined. Functions expecting ``FILE*`` are
+  excluded from the limited C API (:pep:`384`). C extensions using
+  ``<stdio.h>`` must now include it explicitly.  The system ``<stdio.h>``
+  header provides functions like ``printf()`` and ``fopen()``.
+  (Contributed by Victor Stinner in :issue:`45434`.)
+
 Deprecated
 ----------


diff --git a/Include/Python.h b/Include/Python.h
@@ -16,21 +16,18 @@
 #  define _SGI_MP_SOURCE
 #endif

-#include <stdio.h>                // NULL, FILE*
-#ifndef NULL
-#   error "Python.h requires that stdio.h define NULL."
-#endif
-
 #include <string.h>               // memcpy()
+#ifndef Py_LIMITED_API
+#  include <stdio.h>              // FILE*
+#endif
 #ifdef HAVE_ERRNO_H
 #  include <errno.h>              // errno
 #endif
 #ifndef MS_WINDOWS
 #  include <unistd.h>
 #endif
 #ifdef HAVE_STDDEF_H
-   // For size_t
-#  include <stddef.h>
+#  include <stddef.h>             // size_t
 #endif

 #include <assert.h>               // assert()

diff --git a/Misc/NEWS.d/next/C API/2021-10-15-00-30-45.bpo-45434.XLtsbK.rst b/Misc/NEWS.d/next/C API/2021-10-15-00-30-45.bpo-45434.XLtsbK.rst
@@ -0,0 +1,5 @@
+The ``<Python.h>`` header file no longer includes ``<stdio.h>`` if the
+``Py_LIMITED_API`` macro is defined. Functions expecting ``FILE*`` are excluded
+from the limited C API (:pep:`384`). C extensions using ``<stdio.h>`` must now
+include it explicitly.
+Patch by Victor Stinner.