------- Comment #11 from joseph at codesourcery dot com 2006-04-18 11:17 ------- Subject: Re: function result is dereferenced error
On Tue, 18 Apr 2006, falk at debian dot org wrote: > Uhm, this has nothing to do at all with evaluation order. Evaluation > order of arguments is unspecified (not undefined, which wouldn't make a > lot of sense), but that is in fact irrelevant here, it could lead to, > say, 3 1 2, but not 1 1 1. > > The actual problem is that val is modified more than once without an > intervening sequence point, which makes the behavior undefined. No, this testcase is unspecified, not undefined. There are intervening sequence points at the start and end of each call to function, and function calls do not overlap (DR#087); each call to func suspends the execution of main until func returns. However, the evaluation of the arguments to printf may overlap and the order is unspecified, so there are many possible outputs from the program (but "3 2 1" and "3 1 1", for example, are not possible). -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27153
