------- Comment #2 from yuri at rawbw dot com 2009-06-26 17:16 ------- Subject: Re: Erroneous aliasing rules message
pinskia at gcc dot gnu dot org wrote: > ------- Comment #1 from pinskia at gcc dot gnu dot org 2009-06-26 16:47 > ------- > I don't think this is a bogus warning message as you reading a character via Z > which is undefined. (the opposite way is defined though) ISO/IEC 9899, chapter 6.5 paragraph 7 says: --- begin quote --- An object shall have its stored value accessed only by an lvalue expression that has one of the following types:74) a type compatible with the effective type of the object, a qualified version of a type compatible with the effective type of the object, a type that is the signed or unsigned type corresponding to the effective type of the object, a type that is the signed or unsigned type corresponding to a qualified version of the effective type of the object, an aggregate or union type that includes one of the aforementioned types among its members (including, recursively, a member of a subaggregate or contained union), or a character type. --- end quote --- So in my example char and Z are unioned. Therefore I believe typecast should be allowed. Yuri -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40560
