[SYCL] Move accessor_impl to source directory (#6698)

Moving impl part of host accessor implementation to avoid exposing
implementation details in the headers. This allows for more changes
in accessor without breaking ABI.

Also updated the gdb xmethods since it was relying on the
impl details which are not available for gdb(unless libsycl.so is
built with debug symbols) anymore. Instead of accessing members of
impl directly gdb printers now accessing helper methods. To prevent
compiler discarding these methods there are dummy references which
are active when NDEBUG is not defined.

Author: romanovvlad

sycl/gdb/libsycl.so-gdb.py

@@ -51,37 +51,35 @@ def value(self, arg):
 class HostAccessor(Accessor):
     """For Host device memory layout"""
 
-    def payload(self):
-        return self.obj["impl"]["_M_ptr"].dereference()
-
     def memory_range(self, dim):
-        return self.payload()["MMemoryRange"]["common_array"][dim]
+        eval_string = "((" + str(self.obj.type) + ")" + str(self.obj) + ")->getMemoryRange()"
+        return gdb.parse_and_eval(eval_string)["common_array"][dim];
 
     def offset(self, dim):
-        return self.payload()["MOffset"]["common_array"][dim]
+        eval_string = "((" + str(self.obj.type) + ")" + str(self.obj) + ")->getOffset()"
+        return gdb.parse_and_eval(eval_string)["common_array"][dim];
 
     def data(self):
-        return self.payload()["MData"]
-
+        eval_string = "((" + str(self.obj.type) + ")" + str(self.obj) + ")->getPtr()"
+        return gdb.parse_and_eval(eval_string);
 
 class HostAccessorLocal(HostAccessor):
     """For Host device memory layout"""
 
+    def memory_range(self, dim):
+        eval_string = "((" + str(self.obj.type) + ")" + str(self.obj) + ")->getSize()"
+        return gdb.parse_and_eval(eval_string)["common_array"][dim];
+
     def index(self, arg):
         if arg.type.code == gdb.TYPE_CODE_INT:
             return int(arg)
         result = 0
         for dim in range(self.depth):
             result = (
-                result * self.payload()["MSize"]["common_array"][dim]
-                + arg["common_array"][dim]
+                result * self.memory_range() + arg["common_array"][dim]
             )
         return result
 
-    def data(self):
-        return self.payload()["MMem"]
-
-
 class DeviceAccessor(Accessor):
     """For CPU/GPU memory layout"""
 
@@ -104,7 +102,11 @@ def __init__(self, class_type, result_type, depth):
         self.depth = depth
 
     def get_arg_types(self):
-        return gdb.lookup_type("sycl::_V1::id<%s>" % self.depth)
+        try:
+            return gdb.lookup_type("sycl::_V1::id<%s>" % self.depth)
+        except:
+            pass
+        return None
 
     def get_result_type(self, *args):
         return self.result_type