adafruit · dhalbert · Feb 4, 2020 · Feb 4, 2020 · Feb 4, 2020 · Feb 4, 2020
diff --git a/extmod/vfs_fat_file.c b/extmod/vfs_fat_file.c
@@ -28,6 +28,7 @@
 #if MICROPY_VFS && MICROPY_VFS_FAT
 
 #include <stdio.h>
+#include <string.h>
 
 #include "py/runtime.h"
 #include "py/stream.h"
@@ -199,7 +200,7 @@ STATIC mp_obj_t file_open(fs_user_mount_t *vfs, const mp_obj_type_t *type, mp_ar
     FRESULT res = f_open(&vfs->fatfs, &o->fp, fname, mode);
     if (res != FR_OK) {
         m_del_obj(pyb_file_obj_t, o);
-        mp_raise_OSError(fresult_to_errno_table[res]);
+        mp_raise_OSError_errno_str(fresult_to_errno_table[res], args[0].u_obj);
     }
     // If we're reading, turn on fast seek.
     if (mode == FA_READ) {

diff --git a/py/objexcept.c b/py/objexcept.c
@@ -112,17 +112,23 @@ void mp_obj_exception_print(const mp_print_t *print, mp_obj_t o_in, mp_print_kin
         if (o->args == NULL || o->args->len == 0) {
             mp_print_str(print, "");
             return;
-        } else if (o->args->len == 1) {
+        }
+        if (MP_OBJ_IS_SMALL_INT(o->args->items[0]) &&
+            mp_obj_is_subclass_fast(MP_OBJ_FROM_PTR(o->base.type), MP_OBJ_FROM_PTR(&mp_type_OSError)) &&
+            o->args->len <= 2) {
             // try to provide a nice OSError error message
-            if (MP_OBJ_IS_SMALL_INT(o->args->items[0]) &&
-                mp_obj_is_subclass_fast(MP_OBJ_FROM_PTR(o->base.type), MP_OBJ_FROM_PTR(&mp_type_OSError))) {
-                char decompressed[50];
-                const char *msg = mp_common_errno_to_str(o->args->items[0], decompressed, sizeof(decompressed));
-                if (msg != NULL) {
-                    mp_printf(print, "[Errno " INT_FMT "] %s", MP_OBJ_SMALL_INT_VALUE(o->args->items[0]), msg);
-                    return;
+            char decompressed[50];
+            const char *msg = mp_common_errno_to_str(o->args->items[0], decompressed, sizeof(decompressed));
+            if (msg != NULL) {
+                mp_printf(print, "[Errno " INT_FMT "] %s", MP_OBJ_SMALL_INT_VALUE(o->args->items[0]), msg);
+                // if second arg exists, it is filename.
+                if (o->args->len == 2) {
+                    mp_printf(print, ": '%s'", mp_obj_str_get_str(o->args->items[1]));
                 }
+                return;
             }
+        }
+        if (o->args->len == 1) {
             mp_obj_print_helper(print, o->args->items[0], PRINT_STR);
             return;
         }

diff --git a/py/runtime.c b/py/runtime.c
@@ -29,10 +29,12 @@
 #include <string.h>
 #include <assert.h>
 
+
 #include "extmod/vfs.h"
 
 #include "py/parsenum.h"
 #include "py/compile.h"
+#include "py/mperrno.h"
 #include "py/objstr.h"
 #include "py/objtuple.h"
 #include "py/objtype.h"
@@ -1576,6 +1578,14 @@ NORETURN void mp_raise_OSError_msg(const compressed_string_t *msg) {
     mp_raise_msg(&mp_type_OSError, msg);
 }
 
+NORETURN void mp_raise_OSError_errno_str(int errno_, mp_obj_t str) {
+    mp_obj_t args[2] = {
+        MP_OBJ_NEW_SMALL_INT(errno_),
+        str,
+    };
+    nlr_raise(mp_obj_new_exception_args(&mp_type_OSError, 2, args));
+}
+
 NORETURN void mp_raise_OSError_msg_varg(const compressed_string_t *fmt, ...) {
     va_list argptr;
     va_start(argptr,fmt);

diff --git a/py/runtime.h b/py/runtime.h
@@ -161,6 +161,7 @@ NORETURN void mp_raise_RuntimeError(const compressed_string_t *msg);
 NORETURN void mp_raise_ImportError(const compressed_string_t *msg);
 NORETURN void mp_raise_IndexError(const compressed_string_t *msg);
 NORETURN void mp_raise_OSError(int errno_);
+NORETURN void mp_raise_OSError_errno_str(int errno_, mp_obj_t str);
 NORETURN void mp_raise_OSError_msg(const compressed_string_t *msg);
 NORETURN void mp_raise_OSError_msg_varg(const compressed_string_t *fmt, ...);
 NORETURN void mp_raise_NotImplementedError(const compressed_string_t *msg);