bpo-45434: pyport.h no longer includes <stdlib.h> (GH-28914)

Include <stdlib.h> explicitly in C files.

Python.h includes <wchar.h>.

Author: vstinner

Doc/whatsnew/3.11.rst

@@ -556,6 +556,9 @@ Porting to Python 3.11
 
 * The ``<Python.h>`` header file no longer includes ``<stdlib.h>``. C
   extensions using ``<stdlib.h>`` must now include it explicitly.
+  The system ``<stdlib.h>`` header provides functions like:
+  ``malloc()``/``free()``, ``getenv()``, ``strtol()``, ``abs()``, ``strtol()``,
+  ``exit()`` and ``abort()``.
   (Contributed by Victor Stinner in :issue:`45434`.)
 
 Deprecated

Include/Python.h

@@ -33,7 +33,8 @@
 #  include <stddef.h>
 #endif
 
-#include <assert.h>
+#include <assert.h>               // assert()
+#include <wchar.h>                // wchar_t
 
 #include "pyport.h"
 #include "pymacro.h"

Include/internal/pycore_fileutils.h

@@ -88,6 +88,9 @@ extern int _Py_add_relfile(wchar_t *dirname,
 //      ...
 //      _Py_END_SUPPRESS_IPH
 #if defined _MSC_VER && _MSC_VER >= 1900
+
+#  include <stdlib.h>   // _set_thread_local_invalid_parameter_handler()
+
    extern _invalid_parameter_handler _Py_silent_invalid_parameter_handler;
 #  define _Py_BEGIN_SUPPRESS_IPH \
     { _invalid_parameter_handler _Py_old_handler = \

Include/pyport.h

@@ -205,8 +205,6 @@ typedef Py_ssize_t Py_ssize_clean_t;
  * see https://bugs.python.org/issue28126 */
 #define Py_MEMCPY memcpy
 
-#include <stdlib.h>
-
 #ifdef HAVE_IEEEFP_H
 #include <ieeefp.h>  /* needed for 'finite' declaration on some platforms */
 #endif

Misc/NEWS.d/next/C API/2021-10-11-23-03-49.bpo-45434.tsS8I_.rst

@@ -1,3 +1,6 @@
 The ``<Python.h>`` header file no longer includes ``<stdlib.h>``. C
-extensions using ``<stdlib.h>`` must now include it explicitly. Patch by
-Victor Stinner.
+extensions using ``<stdlib.h>`` must now include it explicitly.
+The system ``<stdlib.h>`` header provides functions like:
+``malloc()``/``free()``, ``getenv()``, ``strtol()``, ``abs()``, ``strtol()``,
+``exit()`` and ``abort()``.
+Patch by Victor Stinner.

Modules/_ctypes/_ctypes_test.c

@@ -4,6 +4,8 @@
 #include <windows.h>
 #endif
 
+#include <stdlib.h>               // qsort()
+
 #define EXPORT(x) Py_EXPORTED_SYMBOL x
 
 /* some functions handy for testing */

Modules/_gdbmmodule.c

@@ -5,11 +5,12 @@
 
 #define PY_SSIZE_T_CLEAN
 #include "Python.h"
+#include "gdbm.h"
 
-#include <sys/types.h>
-#include <sys/stat.h>
 #include <fcntl.h>
-#include "gdbm.h"
+#include <stdlib.h>               // free()
+#include <sys/stat.h>
+#include <sys/types.h>
 
 #if defined(WIN32) && !defined(__CYGWIN__)
 #include "gdbmerrno.h"

Modules/_lzmamodule.c

@@ -10,6 +10,7 @@
 #include "Python.h"
 #include "structmember.h"         // PyMemberDef
 
+#include <stdlib.h>               // free()
 #include <string.h>
 
 #include <lzma.h>

Modules/_pickle.c

@@ -12,6 +12,8 @@
 #include "pycore_moduleobject.h"  // _PyModule_GetState()
 #include "structmember.h"         // PyMemberDef
 
+#include <stdlib.h>               // strtol()
+
 PyDoc_STRVAR(pickle_module_doc,
 "Optimized C implementation for the Python pickle module.");
 

Modules/_tracemalloc.c

@@ -5,7 +5,10 @@
 #include "pycore_hashtable.h"
 #include <pycore_frame.h>
 
+#include <stdlib.h>               // malloc()
+
 #include "clinic/_tracemalloc.c.h"
+
 /*[clinic input]
 module _tracemalloc
 [clinic start generated code]*/