Fix used_symbols for the case of a symbol that is in SDFG.symbols but…

… never used

dace/sdfg/sdfg.py

@@ -62,7 +62,7 @@ def __getitem__(self, key):
             token = tokens.pop(0)
             result = result.members[token]
         return result
-    
+
     def __setitem__(self, key, val):
         if isinstance(key, str) and '.' in key:
             raise KeyError('NestedDict does not support setting nested keys')
@@ -1335,24 +1335,12 @@ def used_symbols(self, all_symbols: bool) -> Set[str]:
         defined_syms = set()
         free_syms = set()
 
-        # Exclude data descriptor names, constants, and shapes of global data descriptors
-        not_strictly_necessary_global_symbols = set()
-        for name, desc in self.arrays.items():
+        # Exclude data descriptor names and constants
+        for name in self.arrays.keys():
             defined_syms.add(name)
 
-            if not all_symbols:
-                used_desc_symbols = desc.used_symbols(all_symbols)
-                not_strictly_necessary = (desc.used_symbols(all_symbols=True) - used_desc_symbols)
-                not_strictly_necessary_global_symbols |= set(map(str, not_strictly_necessary))
-
         defined_syms |= set(self.constants_prop.keys())
 
-        # Start with the set of SDFG free symbols
-        if all_symbols:
-            free_syms |= set(self.symbols.keys())
-        else:
-            free_syms |= set(s for s in self.symbols.keys() if s not in not_strictly_necessary_global_symbols)
-
         # Add free state symbols
         used_before_assignment = set()
 
@@ -1378,6 +1366,11 @@ def used_symbols(self, all_symbols: bool) -> Set[str]:
         # Remove symbols that were used before they were assigned
         defined_syms -= used_before_assignment
 
+        # Add the set of SDFG symbol parameters
+        # If all_symbols is False, those symbols would only be added in the case of non-Python tasklets
+        if all_symbols:
+            free_syms |= set(self.symbols.keys())
+
         # Subtract symbols defined in inter-state edges and constants
         return free_syms - defined_syms
 
@@ -1498,7 +1491,7 @@ def signature_arglist(self, with_types=True, for_call=False, with_arrays=True, a
         """
         arglist = arglist or self.arglist(scalars_only=not with_arrays)
         return [v.as_arg(name=k, with_types=with_types, for_call=for_call) for k, v in arglist.items()]
-    
+
     def python_signature_arglist(self, with_types=True, for_call=False, with_arrays=True, arglist=None) -> List[str]:
         """ Returns a list of arguments necessary to call this SDFG,
             formatted as a list of Data-Centric Python definitions.
@@ -1528,7 +1521,7 @@ def signature(self, with_types=True, for_call=False, with_arrays=True, arglist=N
             :param arglist: An optional cached argument list.
         """
         return ", ".join(self.signature_arglist(with_types, for_call, with_arrays, arglist))
-    
+
     def python_signature(self, with_types=True, for_call=False, with_arrays=True, arglist=None) -> str:
         """ Returns a Data-Centric Python signature of this SDFG, used when generating code.
 

dace/transformation/passes/constant_propagation.py

@@ -118,7 +118,7 @@ def apply_pass(self, sdfg: SDFG, _, initial_symbols: Optional[Dict[str, Any]] =
                     del edge.data.assignments[sym]
 
             # If symbols are never unknown any longer, remove from SDFG
-            fsyms = sdfg.free_symbols
+            fsyms = sdfg.used_symbols(all_symbols=False)
             result = {k: v for k, v in result.items() if k not in fsyms}
             for sym in result:
                 if sym in sdfg.symbols: