On Fri, 2009-08-14 at 08:05 +0200, Christoph Spiel wrote: > Hi Elnatan! > > > CIL mistakenly casts the operands of && and || to intType, when in > > fact they are only required to have scalar type. This can lead to a > > bug if the operands have type larger than int and have values which > > truncate to 0 when cast to an int (and if useLogicalOperators is set > > to true). > > IIRC, the C Standard says both operands of the logical > operators _separately_ undergo the "usual unary conversions". > Sloppily phrased, this means all integers with a conversion > rank (CR) less than 40 get promoted to those with CR 40, > i.e. "int" or "unsigned int", and any with a higher CR are left > untouched.
I think you mean the "usual arithmetic conversions" but, at least as I read the Standard, these do *not* apply to operands of && and ||. (For almost every other operator, the Standard seems to make it explicit when conversions are applied to operands, and nothing is said for && and ||.) > > I believe removing the cast solves the problem, but I'm not > > sure whether enumerations should still be cast to intType. > > The Standard only requires that enumerations are > represented as an implementation-defined integer type. I know > compilers that use "char", "short int", or "int" depending on the > number of elements in a particular enum. However, it is > conceivable that a compiler wants to encode a huge enum (think of > auto-generated parser jump tables) as "long int", i.e. at CR 50. > In this case a cast-to-int could be fatal. > > If we can rely on the ekind field of enuminfo, we could trivially > cast the enum to its ekind and then perform the "usual unary > conversions". What do you think about that? Even in this case, I don't they should be cast. Enumerations types *are* scalar types, and that's all the operands of && and || are supposed to be. -Elnatan ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ CIL-users mailing list CIL-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/cil-users
