Messages in this thread | | | Date | Wed, 31 Jul 2013 09:53:30 +0800 | From | Chen Gang <> | Subject | Re: [PATCH trivial] include/linux/coda.h: remove useless '#else' |
| |
On 07/31/2013 09:44 AM, Chen Gang wrote: > On 07/30/2013 08:29 PM, Joe Perches wrote: >> On Tue, 2013-07-30 at 15:30 +0800, Chen Gang wrote: >>> '#else' is useless, need remove. >>> >>> Signed-off-by: Chen Gang <gang.chen@asianux.com> >>> --- >>> include/linux/coda.h | 1 - >>> 1 files changed, 0 insertions(+), 1 deletions(-) >>> >>> diff --git a/include/linux/coda.h b/include/linux/coda.h >>> index cff544f..d30209b 100644 >>> --- a/include/linux/coda.h >>> +++ b/include/linux/coda.h >>> @@ -60,7 +60,6 @@ Mellon the rights to redistribute these changes without encumbrance. >>> >>> #if defined(__linux__) >>> typedef unsigned long long u_quad_t; >>> -#else >>> #endif >>> #include <uapi/linux/coda.h> >>> #endif >> >> Why have the #if at all? >> >> >> > > Hmm... some old version compilers do not define __linux__ automatically > (e.g. or32-linux-gcc 4.5.1-or32-1.0rc1, which is the latest cross > compiler for openrisc, though). > > If not define __linux__, the compiler will report error (u_quad_t is > not defined). > > When we remove "#if defined(__linux__)" from "include/linux/coda.h", > the compiler will not report error, and 'cdev_t' will be defined as > 'dev_t', not 'u_quad_t' (I guess, it is an implicit bug). > > > In "uapi/include/*", only "coda.h" has "#if defined(__linux__)", maybe > they want multiple OS can share the same "coda.h" file (at least, we > can not say it is a bad idea). > > Neither suitable to define __linux__ in "include/linux/coda.h". > > > All together, I think: > > the direct cause: > "uapi/include/coda.h" wants to share itself for multiple OS (so they need check __linux__). > (in "uapi/include/*", only coda.h need check __linux__) > > the root cause: > the compiler for linux should define __linux__ automatically, the latest version of gcc has done, but some of the old version is not. > most of cross compilers have merged their code into gcc main tree, but still left some (e.g. openrisc). > (at least, I can not build openrisc from gcc main tree correctly, but most of others can) > some of latest cross compilers still use old version of gcc, (still not define __linux__ automatically). >
Maybe what I said is incorrect (it is just my current understanding).
Welcome any other members' suggestions or completions for discussing and checking.
Thanks.
> > The related code in "uapi/linux/coda.h" is below: > > -------------------------------code begin------------------------------- > > 73 #if defined(DJGPP) || defined(__CYGWIN32__) > 74 #ifdef KERNEL > 75 typedef unsigned long u_long; > 76 typedef unsigned int u_int; > 77 typedef unsigned short u_short; > 78 typedef u_long ino_t; > 79 typedef u_long dev_t; > 80 typedef void * caddr_t; > 81 #ifdef DOS > 82 typedef unsigned __int64 u_quad_t; > 83 #else > 84 typedef unsigned long long u_quad_t; > 85 #endif > 86 > 87 #define inline > 88 > 89 struct timespec { > 90 long ts_sec; > 91 long ts_nsec; > 92 }; > 93 #else /* DJGPP but not KERNEL */ > 94 #include <sys/time.h> > 95 typedef unsigned long long u_quad_t; > 96 #endif /* !KERNEL */ > 97 #endif /* !DJGPP */ > 98 > 99 > 100 #if defined(__linux__) > 101 #include <linux/time.h> > 102 #define cdev_t u_quad_t > 103 #ifndef __KERNEL__ > 104 #if !defined(_UQUAD_T_) && (!defined(__GLIBC__) || __GLIBC__ < 2) > 105 #define _UQUAD_T_ 1 > 106 typedef unsigned long long u_quad_t; > 107 #endif > 108 #endif /* __KERNEL__ */ > 109 #else > 110 #define cdev_t dev_t > 111 #endif > 112 > > -------------------------------code end--------------------------------- > > > Thanks. >
-- Chen Gang
| |