Add support for os.POSIX_SPAWN_CHDIR and posix_spawn_file_actions_addchdir_np

Author: kulikjak

Lib/subprocess.py

@@ -806,6 +806,7 @@ def _can_use_kqueue():
 # These are primarily fail-safe knobs for negatives. A True value does not
 # guarantee the given libc/syscall API will be used.
 _USE_POSIX_SPAWN = _use_posix_spawn()
+_HAVE_POSIX_SPAWN_CHDIR = hasattr(os, 'POSIX_SPAWN_CHDIR')
 _HAVE_POSIX_SPAWN_CLOSEFROM = hasattr(os, 'POSIX_SPAWN_CLOSEFROM')
 
 
@@ -1836,7 +1837,7 @@ def _get_handles(self, stdin, stdout, stderr):
                     errread, errwrite)
 
 
-        def _posix_spawn(self, args, executable, env, restore_signals, close_fds,
+        def _posix_spawn(self, args, executable, env, restore_signals, close_fds, cwd,
                          p2cread, p2cwrite,
                          c2pread, c2pwrite,
                          errread, errwrite):
@@ -1863,6 +1864,9 @@ def _posix_spawn(self, args, executable, env, restore_signals, close_fds,
                 if fd != -1:
                     file_actions.append((os.POSIX_SPAWN_DUP2, fd, fd2))
 
+            if cwd:
+                file_actions.append((os.POSIX_SPAWN_CHDIR, cwd))
+
             if close_fds:
                 file_actions.append((os.POSIX_SPAWN_CLOSEFROM, 3))
 
@@ -1915,7 +1919,7 @@ def _execute_child(self, args, executable, preexec_fn, close_fds,
                     and preexec_fn is None
                     and (not close_fds or _HAVE_POSIX_SPAWN_CLOSEFROM)
                     and not pass_fds
-                    and cwd is None
+                    and (cwd is None or _HAVE_POSIX_SPAWN_CHDIR)
                     and (p2cread == -1 or p2cread > 2)
                     and (c2pwrite == -1 or c2pwrite > 2)
                     and (errwrite == -1 or errwrite > 2)
@@ -1925,7 +1929,8 @@ def _execute_child(self, args, executable, preexec_fn, close_fds,
                     and gids is None
                     and uid is None
                     and umask < 0):
-                self._posix_spawn(args, executable, env, restore_signals, close_fds,
+                self._posix_spawn(args, executable, env, restore_signals,
+                                  close_fds, cwd,
                                   p2cread, p2cwrite,
                                   c2pread, c2pwrite,
                                   errread, errwrite)

Modules/posixmodule.c

@@ -7606,6 +7606,9 @@ enum posix_spawn_file_actions_identifier {
 #ifdef HAVE_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSEFROM_NP
     ,POSIX_SPAWN_CLOSEFROM
 #endif
+#ifdef HAVE_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR_NP
+    ,POSIX_SPAWN_CHDIR
+#endif
 };
 
 #if defined(HAVE_SCHED_SETPARAM) || defined(HAVE_SCHED_SETSCHEDULER) || defined(POSIX_SPAWN_SETSCHEDULER) || defined(POSIX_SPAWN_SETSCHEDPARAM)
@@ -7864,6 +7867,25 @@ parse_file_actions(PyObject *file_actions,
                 }
                 break;
             }
+#endif
+#ifdef HAVE_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR_NP
+            case POSIX_SPAWN_CHDIR: {
+                PyObject *path;
+                if (!PyArg_ParseTuple(file_action, "OO&"
+                        ";A chdir file_action tuple must have 2 elements",
+                        &tag_obj, PyUnicode_FSConverter, &path))
+                {
+                    goto fail;
+                }
+                errno = posix_spawn_file_actions_addchdir_np(file_actionsp,
+                        PyBytes_AS_STRING(path));
+                if (errno) {
+                    posix_error();
+                    Py_DECREF(path);
+                    goto fail;
+                }
+                Py_DECREF(path);
+                break;
 #endif
             default: {
                 PyErr_SetString(PyExc_TypeError,
@@ -18150,6 +18172,9 @@ all_ins(PyObject *m)
 #ifdef HAVE_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSEFROM_NP
     if (PyModule_AddIntMacro(m, POSIX_SPAWN_CLOSEFROM)) return -1;
 #endif
+#ifdef HAVE_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR_NP
+    if (PyModule_AddIntMacro(m, POSIX_SPAWN_CHDIR)) return -1;
+#endif
 #endif
 
 #if defined(HAVE_SPAWNV) || defined (HAVE_RTPSPAWN)