On Mon, Mar 4, 2013 at 8:27 PM, Rob Landley <rob@xxxxxxxxxxx> wrote: > On 03/03/2013 10:03:55 PM, Eric W. Biederman wrote: >> >> Rob Landley <rob@xxxxxxxxxxx> writes: >> >> > On 03/01/2013 03:57:40 AM, Michael Kerrisk (man-pages) wrote: >> >> > And yet the glibc guys insist on #define >> >> GNU_GNU_GNU_ALL_HAIL_STALLMAN in >> >> > order to access this Linux-specific feature which has nothing >> >> whatsoever to >> >> > do with the FSF. >> >> >> >> This is a misunderstanding. _GNU_SOURCE is the standard way to expose >> >> Linux-specific functionality from POSIX header files. >> > >> > What standard? The Linux kernel is not, and never was, part of the GNU >> > project. >> >> Is the argument that there should be a _LINUX_SOURCE directive in glibc >> for this? > > > If you don't #define any feature test macros at all, you get a bunch of > macros (_BSD_SOURCE, _SVID_SOURCE, _POSIX_SOURCE, _POSIX_C_SOURCE=200809L, > and so on) defined by default in features.h. If you start defining macros, > several of the default ones _go_away_, and you start missing things that are > defined by posix-2008. Yes, defining feature test macros makes definitions > _vanish_ out of the headers, which means feature test macros can actually > reduce code portability. This has nothing to do with reducing portability; have a (careful) read of feature_test_macros(7). [...] > The new musl-libc.org did an _ALL_SOURCE macro that just enables every > feature test macro they implemented. (That's its definition, it's the > feature test macro that says feature test macros area bad idea.) > > >> Although come to think of it I can't imagine how <sched.h> is a POSIX >> header. Last I looked it only had linux specific bits in it. Which >> makes needing any kind of #define strange. > > > My objection is that Linux system calls are not part of the GNU project. > Requiring that macro to get Linux system calls out of bionic, uClibc, klibc, > musl, olibc, dietlibc, or newlib is _silly_. It's the "GNU/Linux" prefix > imposed on the source level, and it's a fairly recent development (I've only > noticed it since 2008 or so). The macro has been present since at least glibc 2.0 (1997). Cheers, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Author of "The Linux Programming Interface"; http://man7.org/tlpi/ -- 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
