extmod/vfs_posix_file: Implement finaliser for files.

Prevent handle leaks when file objects aren't closed explicitly and
fix some MICROPY_CPYTHON_COMPAT issues: this wasn't properly adhered
to because #ifdef was used so it was always on, and closing files
multiple times should be avoided unconditionally.

1 files changed, 8 insertions, 7 deletions

diff --git a/extmod/vfs_posix_file.c b/extmod/vfs_posix_file.c
index 4a3748968..ea19de7fd 100644
--- a/extmod/vfs_posix_file.c
+++ b/extmod/vfs_posix_file.c
@@ -46,7 +46,7 @@ typedef struct _mp_obj_vfs_posix_file_t {
     int fd;
 } mp_obj_vfs_posix_file_t;
 
-#ifdef MICROPY_CPYTHON_COMPAT
+#if MICROPY_CPYTHON_COMPAT
 STATIC void check_fd_is_open(const mp_obj_vfs_posix_file_t *o) {
     if (o->fd < 0) {
         mp_raise_ValueError(MP_ERROR_TEXT("I/O operation on closed file"));
@@ -63,7 +63,7 @@ STATIC void vfs_posix_file_print(const mp_print_t *print, mp_obj_t self_in, mp_p
 }
 
 mp_obj_t mp_vfs_posix_file_open(const mp_obj_type_t *type, mp_obj_t file_in, mp_obj_t mode_in) {
-    mp_obj_vfs_posix_file_t *o = m_new_obj(mp_obj_vfs_posix_file_t);
+    mp_obj_vfs_posix_file_t *o = m_new_obj_with_finaliser(mp_obj_vfs_posix_file_t);
     const char *mode_s = mp_obj_str_get_str(mode_in);
 
     int mode_rw = 0, mode_x = 0;
@@ -185,12 +185,12 @@ STATIC mp_uint_t vfs_posix_file_ioctl(mp_obj_t o_in, mp_uint_t request, uintptr_
             return 0;
         }
         case MP_STREAM_CLOSE:
-            MP_THREAD_GIL_EXIT();
-            close(o->fd);
-            MP_THREAD_GIL_ENTER();
-            #ifdef MICROPY_CPYTHON_COMPAT
+            if (o->fd >= 0) {
+                MP_THREAD_GIL_EXIT();
+                close(o->fd);
+                MP_THREAD_GIL_ENTER();
+            }
             o->fd = -1;
-            #endif
             return 0;
         case MP_STREAM_GET_FILENO:
             return o->fd;
@@ -237,6 +237,7 @@ STATIC const mp_rom_map_elem_t vfs_posix_rawfile_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_tell), MP_ROM_PTR(&mp_stream_tell_obj) },
     { MP_ROM_QSTR(MP_QSTR_flush), MP_ROM_PTR(&mp_stream_flush_obj) },
     { MP_ROM_QSTR(MP_QSTR_close), MP_ROM_PTR(&mp_stream_close_obj) },
+    { MP_ROM_QSTR(MP_QSTR___del__), MP_ROM_PTR(&mp_stream_close_obj) },
     { MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&mp_identity_obj) },
     { MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&vfs_posix_file___exit___obj) },
 };