misc: Clean up

devito/ir/iet/nodes.py

@@ -1,6 +1,7 @@
 """The Iteration/Expression Tree (IET) hierarchy."""
 
 import abc
+import ctypes
 import inspect
 from functools import cached_property
 from collections import OrderedDict, namedtuple
@@ -1059,6 +1060,7 @@ def functions(self):
     def expr_symbols(self):
         ret = []
         if self.pointer.is_Object:
+            assert issubclass(self.pointer._C_ctype, ctypes._Pointer)
             ret.extend([self.pointer._C_symbol, self.pointee._C_symbol])
         elif self.pointer.is_PointerArray or self.pointer.is_TempFunction:
             ret.extend([self.pointer.indexed, self.pointee.indexed])

devito/petsc/iet/routines.py

@@ -138,11 +138,13 @@ def create_matvec_body(self, injectsolve, body, solver_objs, objs):
             dmda, solver_objs['Y_local'], 'INSERT_VALUES', solver_objs['Y_global']
         ])
 
-        # NOTE: Question: I have placed a chunk of the calls in the `stacks` argument
-        # of the `CallableBody` to ensure that these calls precede the `cast` statements.
-        # The 'casts' depend on the calls, so this order is necessary. By doing this,
-        # I avoid having to manually construct the 'casts' and can allow Devito to handle
-        # their construction. Are there any potential issues with this approach?
+        # TODO: Some of the calls are placed in the `stacks` argument of the
+        # `CallableBody` to ensure that they precede the `cast` statements. The
+        # 'casts' depend on the calls, so this order is necessary. By doing this,
+        # you avoid having to manually construct the `casts` and can allow
+        # Devito to handle their construction. This is a temporary solution and
+        # should be revisited
+
         body = [body,
                 vec_restore_array_y,
                 vec_restore_array_x,
@@ -402,6 +404,7 @@ def runsolve(self, solver_objs, objs, rhs_callback, injectsolve):
 
 def build_petsc_struct(iet, name, liveness):
     # Place all context data required by the shell routines into a struct
+    # TODO: Clean this search up
     basics = FindSymbols('basics').visit(iet)
     avoid0 = [i for i in FindSymbols('indexedbases').visit(iet)
               if isinstance(i.function, PETScArray)]

devito/petsc/types/array.py

@@ -16,8 +16,7 @@
 class PETScArray(ArrayBasic, Differentiable):
     """
     PETScArrays are generated by the compiler only and represent
-    a customised variant of ArrayBasic. They are designed to
-    avoid generating a cast in the low-level code.
+    a customised variant of ArrayBasic.
     Differentiable enables compatability with standard Function objects,
     allowing for the use of the `subs` method.
     TODO: Potentially re-evaluate and separate into PETScFunction(Differentiable)