Run reference fix pass on SDFG after deepcopy

dace/sdfg/sdfg.py

@@ -491,7 +491,14 @@ def __deepcopy__(self, memo):
             setattr(result, '_transformation_hist', copy.deepcopy(self._transformation_hist, memo))
         result._sdfg_list = []
         if self._parent_sdfg is None:
+            # Avoid import loops
+            from dace.transformation.passes.fusion_inline import FixNestedSDFGReferences
+
             result._sdfg_list = result.reset_sdfg_list()
+            fixed = FixNestedSDFGReferences().apply_pass(result, {})
+            if fixed:
+                warnings.warn(f'Fixed {fixed} nested SDFG parent references during deep copy.')
+
         return result
 
     @property
@@ -2615,7 +2622,8 @@ def apply_gpu_transformations(self,
 
         self.apply_transformations(GPUTransformSDFG,
                                    options=dict(sequential_innermaps=sequential_innermaps,
-                                                register_trans=register_transients, simplify=simplify),
+                                                register_trans=register_transients,
+                                                simplify=simplify),
                                    validate=validate,
                                    validate_all=validate_all,
                                    permissive=permissive,

dace/transformation/passes/fusion_inline.py

@@ -7,6 +7,7 @@
 from typing import Any, Dict, Optional
 
 from dace import SDFG, properties
+from dace.sdfg import nodes
 from dace.sdfg.utils import fuse_states, inline_sdfgs
 from dace.transformation import pass_pipeline as ppl
 
@@ -20,7 +21,7 @@ class FuseStates(ppl.Pass):
 
     CATEGORY: str = 'Simplification'
 
-    permissive = properties.Property(dtype=bool, default=False, desc='If True, ignores some race conditions checks.')
+    permissive = properties.Property(dtype=bool, default=False, desc='If True, ignores some race condition checks.')
     progress = properties.Property(dtype=bool,
                                    default=None,
                                    allow_none=True,
@@ -82,3 +83,43 @@ def apply_pass(self, sdfg: SDFG, _: Dict[str, Any]) -> Optional[int]:
 
     def report(self, pass_retval: int) -> str:
         return f'Inlined {pass_retval} SDFGs.'
+
+
+@dataclass(unsafe_hash=True)
+@properties.make_properties
+class FixNestedSDFGReferences(ppl.Pass):
+    """
+    Fixes nested SDFG references to parent state/SDFG/node
+    """
+
+    CATEGORY: str = 'Simplification'
+
+    def should_reapply(self, modified: ppl.Modifies) -> bool:
+        return modified & (ppl.Modifies.States | ppl.Modifies.NestedSDFGs)
+
+    def modifies(self) -> ppl.Modifies:
+        return ppl.Modifies.NestedSDFGs
+
+    def apply_pass(self, sdfg: SDFG, _: Dict[str, Any]) -> Optional[int]:
+        modified = 0
+        for node, state in sdfg.all_nodes_recursive():
+            if not isinstance(node, nodes.NestedSDFG):
+                continue
+            was_modified = False
+            if node.sdfg.parent_nsdfg_node is not node:
+                was_modified = True
+                node.sdfg.parent_nsdfg_node = node
+            if node.sdfg.parent is not state:
+                was_modified = True
+                node.sdfg.parent = state
+            if node.sdfg.parent_sdfg is not state.parent:
+                was_modified = True
+                node.sdfg.parent_sdfg = state.parent
+
+            if was_modified:
+                modified += 1
+
+        return modified or None
+
+    def report(self, pass_retval: int) -> str:
+        return f'Fixed {pass_retval} nested SDFG references.'