1 files changed, 17 insertions, 2 deletions
diff --git a/lib/sqlalchemy/sql/roles.py b/lib/sqlalchemy/sql/roles.py
index 72a0bdc95..b861f721b 100644
--- a/lib/sqlalchemy/sql/roles.py
+++ b/lib/sqlalchemy/sql/roles.py
@@ -19,7 +19,7 @@ class SQLRole(object):
 
 
 class UsesInspection(object):
-    pass
+    _post_inspect = None
 
 
 class ColumnArgumentRole(SQLRole):
@@ -54,6 +54,14 @@ class ByOfRole(ColumnListRole):
     _role_name = "GROUP BY / OF / etc. expression"
 
 
+class GroupByRole(UsesInspection, ByOfRole):
+    # note there's a special case right now where you can pass a whole
+    # ORM entity to group_by() and it splits out.   we may not want to keep
+    # this around
+
+    _role_name = "GROUP BY expression"
+
+
 class OrderByRole(ByOfRole):
     _role_name = "ORDER BY expression"
 
@@ -92,7 +100,14 @@ class InElementRole(SQLRole):
     )
 
 
-class FromClauseRole(ColumnsClauseRole):
+class JoinTargetRole(UsesInspection, StructuralRole):
+    _role_name = (
+        "Join target, typically a FROM expression, or ORM "
+        "relationship attribute"
+    )
+
+
+class FromClauseRole(ColumnsClauseRole, JoinTargetRole):
     _role_name = "FROM expression, such as a Table or alias() object"
 
     _is_subquery = False