[CIL users] Cil.constFoldBinOp bug

[Benjamin M. <ben...@ce...>]

Hello,

Cil.constFoldBinOp may compute unspecified shifts.
For example shifting a char by more than 8 is unspecified and should be l=
eft=20
unchanged by Cil.

Here is a patch to fix this: just replace shiftInBounds in constFoldBinOp=
 by

let shiftInBounds i2 =3D
         (* We only try to fold shifts if the second arg is positive and
            less than the size of the type of the first argument.
            Otherwise, the semantics are processor-dependent, so let the =
compiler
	   sort it out. *)
         if machdep then
           try
             i2 >=3D Int64.zero && i2 < (Int64.of_int (bitsSizeOf (typeOf=
 e1')))
           with SizeOfError _ -> false
         else false
in

Is this patch correct ?

Cheers,
--=20
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