  Attribute grammars (AGs) are known to be a useful formalism for semantic
analysis and translation. However, debugging AGs is complex owing to inherent
difficulties of AGs, such as recursive grammar structure and attribute
dependency. In this paper, a new systematic method of debugging AGs is
proposed. Our approach is, in principle, based on previously proposed
algorithmic debugging of AGs, but is more general. This easily enables
integration of various query-based systematic debugging methods, including the
slice-based method. The proposed method has been implemented in Aki, a debugger
for AG description. We evaluated our new approach experimentally using Aki,
which demonstrates the usability of our debugging method.
