[exir] Allow verifiers in _transform (#10322)

This is to allow users to transform an ExportedProgram using passes in places where it may result in a dialect that is not compliant with the original creation context.

For example, if an ExportedProgram was created in an edge dialect and now needs to be run and transformed in a way that is not compliant with the EdgeDialectVerifier, such as in a delegate preprocess() function, then the user may want to override the verifier with their own or simply disable it.

Differential Revision: [D73205727](https://our.internmc.facebook.com/intern/diff/D73205727/)

Author: pytorchbot

exir/program/_program.py

@@ -212,7 +212,30 @@ def _get_updated_graph_signature(
     return new_signature
 
 
-def _transform(self, *passes: PassType) -> "ExportedProgram":
+def _transform(
+    self,
+    *passes: PassType,
+    override_verifiers: None | list[Type[Verifier]] = None,
+) -> "ExportedProgram":
+    """
+    Transforms the program according to the provided passes.
+
+    Args:
+        self: The ExportedProgram instance to transform
+        *passes: A sequence of passes to apply to the program
+        override_verifiers: Optional list of verifier classes to use instead of the default verifiers.
+            This is needed if the transforms yields illegal graph that the default verifier cannot handle.
+
+    Returns:
+        ExportedProgram: A new ExportedProgram with the transformations applied, or self if no changes were made
+    """
+    # A user friendly check to avoid vararg surprises, PEP 3102
+    assert not any(
+        isinstance(p, (list, Verifier)) for p in passes
+    ), f"Expected all passes to be of PassType, not list or Verifier. Use override_verifiers kwarg instead. Got: {list(passes)}"
+
+    for p in list(passes):
+        print(type(p))
     pm = PassManager(list(passes))
     res = pm(self.graph_module)
     transformed_gm = res.graph_module if res is not None else self.graph_module
@@ -221,7 +244,9 @@ def _transform(self, *passes: PassType) -> "ExportedProgram":
     if transformed_gm is self.graph_module and not res.modified:
         return self
 
-    return _update_exported_program_graph_module(self, transformed_gm)
+    return _update_exported_program_graph_module(
+        self, transformed_gm, override_verifiers
+    )
 
 
 def _update_exported_program_graph_module(

exir/program/test/test_program.py

@@ -22,6 +22,7 @@
 from executorch.exir.pass_base import ExportPass
 from executorch.exir.passes import MemoryPlanningPass
 from executorch.exir.program._program import (
+    _transform,
     EdgeProgramManager,
     ExecutorchProgramManager,
     to_edge,
@@ -34,6 +35,7 @@
 from executorch.extension.pybindings.portable_lib import (
     _load_for_executorch_from_buffer,
 )
+from torch._export.verifier import Verifier
 from torch.export import Dim, export, ExportedProgram
 from torch.export._trace import _export
 
@@ -273,7 +275,6 @@ def get_executorch_memory_planning_passes() -> Dict[str, MemoryPlanningPass]:
             for output_val in method.outputs:
                 evalue = method.values[output_val]
                 self.assertNotEqual(evalue.val.allocation_info, None)
-        else:
             for input_val in method.inputs:
                 evalue = method.values[input_val]
                 self.assertEqual(evalue.val.allocation_info, None)
@@ -847,3 +848,19 @@ def test_save_fails(self):
         et = edge.to_executorch()
         with self.assertRaises(ValueError):
             _ = et.save("/tmp/test_save.pt")
+
+    def test__transform_override_verifiers(self):
+        """Test that _transform can override verifiers in the exported program."""
+        class MyVerifier(Verifier):
+            dialect: str = "MY_DIALECT"
+            def __init__(self):
+                super().__init__()
+
+        model = TestLinear()
+        program = torch.export.export(model, model._get_random_inputs(), strict=True)
+        self.assertFalse(issubclass(program.verifiers[0], MyVerifier))
+
+        # Apply transformation with custom verifier
+        transformed = _transform(program, AddToMulPassEdge(), override_verifiers=[MyVerifier])
+        self.assertTrue(issubclass(transformed.verifiers[0], MyVerifier))
+        self.assertFalse(issubclass(program.verifiers[0], MyVerifier))