api: fix c_datatype hack

Author: mloubout

devito/ir/iet/visitors.py

@@ -477,7 +477,7 @@ def visit_Break(self, o):
     def visit_Return(self, o):
         v = 'return'
         if o.value is not None:
-            v += ' %s' % o.value
+            v += f' {ccode(o.value)}'
         return c.Statement(v)
 
     def visit_Definition(self, o):

devito/symbolics/extended_sympy.py

@@ -418,7 +418,6 @@ def _C_ctype(self):
             ctype = dtype_to_ctype(ctype)
         except:
             pass
-
         return ctype
 
     @property

devito/symbolics/printer.py

@@ -1,7 +1,6 @@
 """
 Utilities to turn SymPy objects into C strings.
 """
-
 import numpy as np
 import sympy
 

devito/tools/dtypes_lowering.py

@@ -144,7 +144,7 @@ def dtype_to_ctype(dtype):
 
     if isinstance(dtype, CustomDtype):
         return dtype
-    elif issubclass(dtype, ctypes._SimpleCData):
+    elif issubclass(dtype, (ctypes._Pointer, ctypes.Structure, ctypes._SimpleCData)):
         # Bypass np.ctypeslib's normalization rules such as
         # `np.ctypeslib.as_ctypes_type(ctypes.c_void_p) -> ctypes.c_ulong`
         return dtype

devito/types/basic.py

@@ -1,7 +1,7 @@
 import abc
 import inspect
 from collections import namedtuple
-from ctypes import POINTER, _Pointer, c_char_p, c_char, Structure
+from ctypes import POINTER, _Pointer, c_char_p, c_char
 from functools import reduce, cached_property
 from operator import mul
 
@@ -81,7 +81,7 @@ def _C_name(self):
     @property
     def _C_typedata(self):
         """
-        The type of the object in the generated code as a `str`.
+        The type of the object's data in the generated code.
         """
         _type = self._C_ctype
         if isinstance(_type, CustomDtype):
@@ -94,10 +94,6 @@ def _C_typedata(self):
         if _type is c_char_p:
             _type = c_char
 
-        # ctypes Structures such as dense/array use directly the struct name
-        if issubclass(_type, Structure):
-            _type = f'struct {_type.__name__}'
-
         return _type
 
     @abc.abstractproperty