bpo-46176: mmap module adding MAP_STACK constant. (GH-30252)

Author: devnexen

Doc/library/mmap.rst

@@ -367,8 +367,12 @@ MAP_* Constants
           MAP_ANON
           MAP_ANONYMOUS
           MAP_POPULATE
+          MAP_STACK
 
     These are the various flags that can be passed to :meth:`mmap.mmap`. Note that some options might not be present on some systems.
 
     .. versionchanged:: 3.10
        Added MAP_POPULATE constant.
+
+    .. versionadded:: 3.11
+       Added MAP_STACK constant.

Misc/NEWS.d/next/Library/2021-12-25-11-11-21.bpo-46176.EOY9wd.rst

@@ -0,0 +1 @@
+Adding the ``MAP_STACK`` constant for the mmap module.

Modules/mmapmodule.c

@@ -1637,6 +1637,11 @@ mmap_exec(PyObject *module)
 #endif
 #ifdef MAP_POPULATE
     ADD_INT_MACRO(module, MAP_POPULATE);
+#endif
+#ifdef MAP_STACK
+    // Mostly a no-op on Linux and NetBSD, but useful on OpenBSD
+    // for stack usage (even on x86 arch)
+    ADD_INT_MACRO(module, MAP_STACK);
 #endif
     if (PyModule_AddIntConstant(module, "PAGESIZE", (long)my_getpagesize()) < 0 ) {
         return -1;