Date: Sun, 21 Oct 2012 02:38:17 +0200 From: Abdoulaye Walsimou GAYE <awg@...toolkit.org> To: musl@...ts.openwall.com Subject: Re: [PATCH 2/4] Add basic sys/cdefs.h found on most unix On 10/21/2012 02:11 AM, Rich Felker wrote: > On Sun, Oct 21, 2012 at 02:13:47AM +0200, Abdoulaye Walsimou GAYE wrote: >> On 10/21/2012 01:38 AM, Rich Felker wrote: >>> On Sun, Oct 21, 2012 at 01:38:52AM +0200, Abdoulaye Walsimou GAYE wrote: >>>> On 10/21/2012 01:18 AM, Isaac Dunham wrote: >>>>> On Sat, 20 Oct 2012 22:15:43 +0200 >>>>> Abdoulaye Walsimou Gaye <awg@...toolkit.org> wrote: >>>>> >>>>>> Signed-off-by: Abdoulaye Walsimou Gaye <awg@...toolkit.org> >>>>>> --- >>>>>> include/sys/cdefs.h | 22 ++++++++++++++++++++++ >>>>>> 1 file changed, 22 insertions(+) >>>>>> create mode 100644 include/sys/cdefs.h >>>>> I'm pretty sure that the last three times sys/cdefs.h was proposed, >>>>> it was rejected. >>>> Unfortunately many packages (wrongly?) use to rely on macros defined there, >>> I've found it's really very few; an equivalent sys/cdefs.h does not >>> exist on most systems. It was never intended for use by applications; >>> it's an internal part of glibc (and perhaps also some BSDs?) used for >>> handling backwardsness like pre-ANSI C compilers (abstracting const >>> away as __const, or abstracting away prototypes with __P()) and >>> optional use of GCC-specific features. >> But applications borrowed from systems internal and ported to others >> systems tend to use these macros (libtirpc, libbsd come in mind). >> Major BSD systems have it (FreeBSD, NetBSD, OpenBSD, PCBSD), it not >> a reason to have it on linux systems but it helps/simplifies packages porting >> from these OS. > As it stands, these libraries/apps won't work anywhere but GNU/Linux > (by "GNU/" I mean glibc-based) or BSD. If the offending code is > removed and replaced with what should be there, they'd be a lot more > portable. So I would not say sys/cdefs.h aids in porting them; I'd say > its presence gives these libs/apps a way to be lazy and > non-portable... I am not the writer of these applications and going to patch old applications that are there for a while is just not an option. > >>> For things like 'extern "C"', there's no reason to use sys/cdefs.h; >>> the just writing the code it expands to inline is much more >>> clear/informative and provides better performance as a nice side >>> effect. >>> >>>> sometimes indirectly via <features.h>. >>> I don't see what you mean by this. >> some applications use <features.h> to get macros defined in <sys/cdefs.h> >> as on glibc, eglibc, uClibc <features.h> have a #include <sys/cdefs.h> > Both of these usages are incorrect and could easily be fixed (both are > implementation-internal headers). > > Rich May be it is incorrect, unfortunately it there for a while and some applications rely on it. cheers, AWG
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.