[one-cmds] Revise one-import-onnx with new force_ext (#13921)

This will revise one-import-onnx with new force_ext option.
- added some comments how extension is called with force_ext and
disable_ext options

ONE-DCO-1.0-Signed-off-by: SaeHie Park <[email protected]>

compiler/one-cmds/one-import-onnx

@@ -172,10 +172,30 @@ def _get_parser():
         'Ensure generated circle model preserves the I/O order of the original onnx model.'
     )
 
-    # force use onnx-tf for one-import-onnx-ext is installed
-    parser.add_argument('--disable_ext',
-                        action='store_true',
-                        help='Disable one-import-onnx-ext and use legacy onnx-tf package')
+    # NOTE How one-import-onnx-ext is called;
+    # - applies only when one-import-onnx-ext is installed
+    # - default onnx-tf is called for conversion
+    # - if onnx-tf fails, one-import-onnx-ext is called
+    # - if 'force_ext' is given, skip onnx-tf and call one-import-onnx-ext
+    # - if 'disable_ext' is given, one-import-onnx-ext is not called
+    # - both 'force_ext', 'disable_ext' should not be set
+
+    # converter version
+    extension_group = parser.add_argument_group('extension arguments')
+    use_extension = extension_group.add_mutually_exclusive_group()
+
+    # use one-import-onnx-ext in the first place
+    use_extension.add_argument(
+        '--force_ext',
+        action='store_true',
+        help='Use one-import-onnx-ext in first attempt and skip default tool')
+
+    # do not call one-import-onnx-ext when default one-import-onnx fails
+    use_extension.add_argument('--disable_ext',
+                               action='store_true',
+                               help='Disable one-import-onnx-ext for second attempt')
+
+    parser.add_argument('--use_extension', type=str, help=argparse.SUPPRESS)
 
     # save intermediate file(s)
     parser.add_argument('--save_intermediate',
@@ -244,6 +264,15 @@ def _remap_io_names(onnx_model):
     remapper.update()
 
 
+def _force_ext(args):
+    if oneutils.is_valid_attr(args, 'force_ext'):
+        return True
+    env_force_ext = os.getenv('ONE_IMPORT_ONNX_EXT_FORCE')
+    if env_force_ext == '1' or env_force_ext == 'Y':
+        return True
+    return False
+
+
 def _disable_ext(args):
     if oneutils.is_valid_attr(args, 'disable_ext'):
         return True