Messages in this thread | | | From | Kyle Moffett <> | Subject | Re: Linux Kernel include files | Date | Tue, 26 Jun 2007 21:32:39 -0400 |
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On Jun 22, 2007, at 11:00:38, Adrian Bunk wrote: > It would certainly help if Joerg would tell what exactly breaks, > but I spot one likely problem in include/asm-i386/types.h: > > #if defined(__GNUC__) && !defined(__STRICT_ANSI__) > typedef __signed__ long long __s64; > typedef unsigned long long __u64; > #endif > > It might make sense to remove the #if and simply require that a C > compiler under Linux must know about the C99 "long long"?
Gah, this particular topic and a few other similar header- compatibility ones show up once a month on LKML; I should probably just make a patch to fix all the types.h files and be done with it. The proper solution is this:
# if __STDC_VERSION__ >= 19901L typedef signed long long __s64; typedef unsigned long long __u64; # elif defined(__GNUC__) __extension__ typedef signed long long __s64; __extension__ typedef unsigned long long __u64; # else # error "Your compiler doesn't support long long (IOW: It sucks). Please get a new one" # endif
That way if you have any kind of vaguely-long-long-compatible compiler then it will work, and otherwise you'll get a nice useful error message. It also makes sure that GCC doesn't spew warnings/ errors when in c89-pedantic mode. The "__extension__" keyword is designed for use in implementation header files which want to use GCC- isms unconditionally.
Cheers, Kyle Moffett
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