where l is one of any, basic, weak, layout, strict, std, or strong. See Table B–11 for a detailed explanation of the different levels of disambiguation.
If you do not specify -Xalias_level, the default of the flag is -Xalias_level=any. This means that there is no type-based alias-analysis. If you specify -Xalias_level but do not supply a level, the default is -Xalias_level=layout.
Be sure to run lint at a level of disambiguation that is no more strict than the level at which you ran the compiler. If you run lint at a level of disambiguation that is more strict than the level at which you compiled, the results will be difficult to interpret and possibly misleading.
See 4.6.3 lint Filters for a detailed explanation of disambiguation as well as a list of pragmas designed to help with disambiguation.