On 03/19/2014 01:30 PM, Robert P. J. Day wrote: > > another possibly silly observation -- /usr/include/features.h makes > no mention of _ISOC95_SOURCE in the early comment listing all(?) of > the possible feature test macros: > > ... snip ... > __STRICT_ANSI__ ISO Standard C. > _ISOC99_SOURCE Extensions to ISO C89 from ISO C99. > _ISOC11_SOURCE Extensions to ISO C99 from ISO C11. > _POSIX_SOURCE IEEE Std 1003.1. > ... snip ... > > despite its "USE" macro being mentioned further down in the same > comment: > > ... snip ... > __USE_ISOC11 Define ISO C11 things. > __USE_ISOC99 Define ISO C99 things. > __USE_ISOC95 Define ISO C90 AMD1 (C95) things. > ... snip ... > > as well as even further down: > > #undef __USE_ISOC95 > ... > #ifdef _GNU_SOURCE > # undef _ISOC95_SOURCE > # define _ISOC95_SOURCE 1 > ... > /* This is to enable the ISO C90 Amendment 1:1995 extension. */ > #if (defined _ISOC99_SOURCE || defined _ISOC11_SOURCE \ > || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199409L)) > # define __USE_ISOC95 1 > #endif > ... > > i notice in the man pages Changes file the reference that > _ISOC95_SOURCE is now allegedly bogus: > > feature_test_macros.7 > Michael Kerrisk [Joseph S. Myers] > Remove mention of bogus _ISOC95_SOURCE macro > The _ISOC95_SOURCE macro is defined in <features.h>, but it > does nothing. So remove discussion of it, and move some of > the discussion of C95 under the ISOC99_SOURCE subhead. Joseph pointed out to me that defining _ISOC95_SOURCE actually does nothing. So it really is bogus. There is the __USE_ISOC95 macro that is used internally. But, I think for most purposes we can consider that to be subsumed under C99. > but there appear to still be a couple checks for it: > > man3/fwide.3:_ISOC95_SOURCE /* Since glibc 2.12 */ || > man3/wprintf.3:_ISOC95_SOURCE /* Since glibc 2.12 */ || Those to are bogus, and now I've removed them. Thanks for catching that. Cheers, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
