Bob Friesenhahn wrote (on Sun 17-Jun-2012 at 20:13 +0100): > On Sun, 17 Jun 2012, 'Chris Hall' wrote: > > So, my first question is: am I mistaken in thinking that using > > -std=c99 will help, portability-wise ? > It is often expected that requesting a specific standard at > compile-time will aid with portability. Usually the results are the > opposite of that because the standard requires that interfaces not > specified by the standard are not exposed and are therefore not > usable. Likewise, if a system does not support the standard, the > result is usually utter failure. It is typical that there are > multiple conflicting standards supported by the OS and requesting > one breaks use of the other. I'm sorry, but I don't understand: if some interface is not supported by the standard, I don't want it... because if I use something outside the standard I cannot reasonably expect some other c99 compiler to support it. Surely ? I try to be reasonably conservative and I wouldn't have much sympathy with a compiler that doesn't cover the c99 things I do use. Since I spend most of the time using gcc, I want to avoid inadvertently using gnu99 extensions. So, what I currently do is avoid AC_PROG_CC_C99 for the compilers I know about, and for gcc, in particular, set -std=c99 "by hand". Breaking some other compiler by using gcc specific extensions seems to me to be a greater risk than using some part of c99 which is not supported by that compiler. Or, at least, if I break things by issuing code which is not Standard c99 that's my fault, where finding that some compiler is not very good at c99 is not ! If I have to take steps to cope with some compiler that doesn't support c99 well enough, then I so be it. It seems to me that taking steps to "escape" Standard <whatever>, if required, is preferable to having to take steps to "force" Standard <whatever>. On the other hand, if gnu99 is in practice a more widely followed standard than ISO C99, then I can stop worrying and let AC_PROG_CC_C99 select gnu99 for me. Chris _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx https://lists.gnu.org/mailman/listinfo/autoconf
