Many refactoring tools need the AST (and more) from a frontend to do type-aware refactoring, among other things. If we have, for example, struct a { int x;

Many refactoring tools need the AST (and more) from a frontend to do type-aware refactoring, among other things. If we have, for example, struct a { int x; } sa; struct b { float x; } sb; and we want to rename sa.x into sa.y, then the refactoring tool needs to understand types in order to leave sb.x alone. And if sa.x - sa.x is not in the AST, it will not be changed into sa.y - sa.y which will yield errors.