Re: [Qemu-trivial] [Qemu-devel] [PATCH 1/4] fix implicit declaration of syscall() in linux-user/mmap.c

[Stefan Weil <sw@weilnetz.de>]

Am 10.12.2012 07:59, schrieb John Spencer:
> on glibc, this header is getting pulled in automatically via
> another header, however on musl we need to include it explicitly.
>
> linux-user/mmap.c:705:9: warning: implicit declaration of function 'syscall'
> linux-user/mmap.c:705:9: warning: nested extern declaration of 'syscall'
>
> Signed-off-by: John Spencer<maillist-qemu@barfooze.de>
>
> ---
>   linux-user/mmap.c |    1 +
>   1 files changed, 1 insertions(+), 0 deletions(-)
>
> diff --git a/linux-user/mmap.c b/linux-user/mmap.c
> index b412e3f..171b449 100644
> --- a/linux-user/mmap.c
> +++ b/linux-user/mmap.c
> @@ -25,6 +25,7 @@
>   #include<sys/types.h>
>   #include<sys/stat.h>
>   #include<sys/mman.h>
> +#include<sys/syscall.h>
>   #include<linux/mman.h>
>   #include<linux/unistd.h>


According to the Linux man-page SYSCALL(2), syscall
is declared in unistd.h. On my Debian Linux with glibc,
this information is correct. Here is the result of grep:

/usr/include/unistd.h:extern long int syscall (long int __sysno, ...) 
__THROW;

unistd.h is included implicitly via qemu-common.h,
so if you don't get the declaration, there is a buggy
implementation of the header files in musl:

http://git.musl-libc.org/cgit/musl/plain/include/unistd.h
does not match the Linux documentation.

Please report this to the musl developers.

Regards
Stefan Weil