Add support for self.parent

compiler/passes/src/type_checking/check_expressions.rs

@@ -116,6 +116,16 @@ impl<'a> ExpressionVisitor<'a> for TypeChecker<'a> {
                                 ))
                             }
                             return Some(Type::Address);
+                        },
+                        sym::parent => {
+                            // Check that operation is not invoked in a `finalize` block.
+                            if self.is_finalize {
+                                self.handler.emit_err(TypeCheckerError::invalid_operation_inside_finalize(
+                                    "self.parent",
+                                    access.name.span(),
+                                ))
+                            }
+                            return Some(Type::Address)
                         }
                         _ => {
                             self.emit_err(TypeCheckerError::invalid_self_access(access.name.span()));

compiler/span/src/symbol.rs

@@ -252,6 +252,7 @@ symbols! {
     main,
     mapping,
     Mut: "mut",
+    parent,
     Return: "return",
     SelfLower: "self",
     SelfUpper: "Self",

errors/src/errors/type_checker/type_checker_error.rs

@@ -387,7 +387,7 @@ create_messages!(
     @formatted
     invalid_self_access {
         args: (),
-        msg: format!("The allowed accesses to `self` are `self.caller`."),
+        msg: format!("The allowed accesses to `self` are `self.caller` and `self.parent`."),
         help: None,
     }