compiler: make sure complex ctype is handled properly for typedata

Author: mloubout

devito/symbolics/extended_dtypes.py

@@ -34,6 +34,8 @@ class c_complex(NoDeclStruct):
 
     _fields_ = [('real', ctypes.c_float), ('imag', ctypes.c_float)]
 
+    _base_dtype = True
+
     @classmethod
     def from_param(cls, val):
         return cls(val.real, val.imag)
@@ -44,6 +46,8 @@ class c_double_complex(NoDeclStruct):
 
     _fields_ = [('real', ctypes.c_double), ('imag', ctypes.c_double)]
 
+    _base_dtype = True
+
     @classmethod
     def from_param(cls, val):
         return cls(val.real, val.imag)

devito/types/basic.py

@@ -87,17 +87,20 @@ def _C_typedata(self):
         if isinstance(_type, CustomDtype):
             return _type
 
-        _pointer = False
         while issubclass(_type, _Pointer):
-            _pointer = True
             _type = _type._type_
 
         # `ctypes` treats C strings specially
         if _type is c_char_p:
             _type = c_char
 
-        if issubclass(_type, Structure) and _pointer:
-            _type = f'struct {_type.__name__}'
+        try:
+            # We have internal types such as c_complex that are
+            # Structure too but should be treated as plain c_type
+            _type._base_dtype
+        except AttributeError:
+            if issubclass(_type, Structure):
+                _type = f'struct {_type.__name__}'
 
         return _type