Re: [ERROR] perf build failure on current tip:perf/core

[Ingo Molnar <mingo@elte.hu>]

* Namhyung Kim <namhyung@gmail.com> wrote:

> >>   $ map pwrite
> >>   The program 'map' is currently not installed.  You can install it by
> >> typing:
> >>   sudo apt-get install sgt-puzzles
> >> 
> >> I don't think this is the package what you said. Anyway quick grep'ing
> >> pwrite tells me it's in the unistd.h:
> >> 
> >>   $ grep pwrite /usr/include/unistd.h
> >>   extern ssize_t pwrite (int __fd, __const void *__buf, size_t __n,
> >>   extern ssize_t __REDIRECT (pwrite, (int __fd, __const void *__buf,
> >> 			     pwrite64) __wur;
> >>   #   define pwrite pwrite64
> >
> > There's multiple definitions there, and we get lost somehow - as 
> > unistd.h is included:
> >
> >   ~/tip/tools/perf> grep -n unistd.h util/trace-event-info.c
> >   34:#include <unistd.h>
> >
> > Thanks,
> >
> > 	Ingo
> 
> This is the content of my /usr/include/unistd.h:
> 
> #ifdef __USE_UNIX98
> # ifndef __USE_FILE_OFFSET64
> extern ssize_t pread (int __fd, void *__buf, size_t __nbytes,
> 		      __off_t __offset) __wur;
> extern ssize_t pwrite (int __fd, __const void *__buf, size_t __n,
> 		       __off_t __offset) __wur;
> # else
> #  ifdef __REDIRECT
> extern ssize_t __REDIRECT (pread, (int __fd, void *__buf, size_t __nbytes,
> 				   __off64_t __offset),
> 			   pread64) __wur;
> extern ssize_t __REDIRECT (pwrite, (int __fd, __const void *__buf,
> 				    size_t __nbytes, __off64_t __offset),
> 			   pwrite64) __wur;
> #  else
> #   define pread pread64
> #   define pwrite pwrite64
> #  endif
> # endif
> 
> # ifdef __USE_LARGEFILE64
> extern ssize_t pread64 (int __fd, void *__buf, size_t __nbytes,
> 			__off64_t __offset) __wur;
> extern ssize_t pwrite64 (int __fd, __const void *__buf, size_t __n,
> 			 __off64_t __offset) __wur;
> # endif
> #endif
> 
> I think all of pread/write functions are properly defined here:
> 
>   $ echo '#include <unistd.h>' | \
>   > gcc -xc -E -dM -D_GNU_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 - | \
>   > grep -e UNIX98 -e LARGEFILE64 -e FILE_OFFSET
>   #define __ILP32_OFFBIG_CFLAGS "-m32 -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64"
>   #define _LARGEFILE64_SOURCE 1
>   #define __USE_UNIX98 1
>   #define __USE_LARGEFILE64 1
>   #define _FILE_OFFSET_BITS 64
>   #define __USE_FILE_OFFSET64 1

So which preprocessor branch within unistd.h does it get into on 
your system and why isnt there a pwrite()/pwrite64() prototype 
once it goes along that path?

You could try an ugly approach and edit your unistd.h and put in 
debug lines like this:

#warn got here: __LINE__

and thus see which branch it really gets into.

(save a backup copy of unistd.h first ;-)

Thanks,

	Ingo