Messages in this thread | | | Date | Mon, 18 Jun 2007 08:27:15 -0600 | From | Robert Hancock <> | Subject | Re: [patch] use __asm__ and __volatile__ in i386/arm/s390 byteorder.h |
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David Woodhouse wrote: > On Mon, 2007-06-18 at 01:24 +0200, Arnd Bergmann wrote: >> On Monday 18 June 2007, Arjan van de Ven wrote: >>> On Sun, 2007-06-17 at 18:33 -0400, Mike Frysinger wrote: >>>> This changes asm() to __asm__() and volatile to __volatile__ so that these >>>> headers can be used with gcc's -std=c99. >>> hmm but the kernel doesn't use -std=c99... >> The byteorder headers are exported to user space through >> include/asm-generic/Kbuild.asm, and they are used by a number >> of other exported headers, so they should work with any >> gcc flags that a user might want to use. > > Even those headers which are exported are _still_ kernel headers¹. The > 'caveat emptor' principle still applies to them, and we don't have to be > _that_ anal about it. GNU extensions (and proper C types, for that > matter) should be acceptable, surely?
If we expect userspace apps to include them, then I would vote for no, not for anything outside of #ifdef __KERNEL__ in exported headers. Keep in mind also that C++ apps may need to include these as well and those extensions don't always play well in C++ mode. (Last instance I ran into was the ioctl argument checking macros _IOR, _IOW, etc. that create non-compiling code if you use them in a C++ program.)
-- Robert Hancock Saskatoon, SK, Canada To email, remove "nospam" from hancockr@nospamshaw.ca Home Page: http://www.roberthancock.com/
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