Re: [Chicken-users] Sendfile error on Red Hat 5.5 64 Bit

[David Krentzlin]

Hello Vok,

thanks for trying this. This really helped. I somehow feared that this 
would be the case. The problem is that _XOPEN_SOURCE is used to add 
another define (usally in feature.h) which is then used in bit/fcntl.h 
to decide if POSIX_FADV_* constants shall be defined.

However the c-file that chicken generates includes chicken.h before any 
other code so there is no chance for a generated program to add this in 
front of it, which would fix the problem.

I could set this define directly but i don't know how portable that is.

The code that is affected by all this is not vital for the overall 
functionality. I've removed that code and released 1.7.14, so that the 
egg can be installed.

I'll try to find another way to get the feature back later.

Please give 1.7.14 a try and let me know if it works

Cheers David


On 01.12.2011 21:23, Vok Vojwo wrote:
> 2011/12/1 David Krentzlin<address@hidden>:
> > Could you please try again the current tip and tell me if it changed?
> > Also if it didn't change, could you please include your chicken.h in the
> > probing code and see if it still gets selected?
>
> The chicken header seems to be evil.
>
> This probe disables fadvise:
>
> (define posix-fadvise-test #<<CODE
> #define _XOPEN_SOURCE 600
> #include<chicken.h>
> #include<fcntl.h>
> int main(){
>    int fake_fd = 0;
>    posix_fadvise(fake_fd,0,0,POSIX_FADV_SEQUENTIAL);
>    return posix_fadvise(fake_fd,0,0,POSIX_FADV_NOREUSE);
> }
> CODE
> )
>
> Compiles fine but without fadvise.
>
> Switching the order of chicken.h and fcntl.h does not change anything.
>
> If you use gcc -E you can see that the part with the fadvice
> definitions gets removed from the bits/fcntl.h header.
>
> But when I write the probe to a single file it compiles fine:
>
> # cat probe.c
> #define _XOPEN_SOURCE 600
> #include<chicken.h>
> #include<fcntl.h>
> int main(){
>    int fake_fd = 0;
>    posix_fadvise(fake_fd,0,0,POSIX_FADV_SEQUENTIAL);
>    return posix_fadvise(fake_fd,0,0,POSIX_FADV_NOREUSE);
> }
>
> # gcc -c probe.c -fno-strict-aliasing -fwrapv -DHAVE_CHICKEN_CONFIG_H
> -DC_ENABLE_PTABLES -Os -fomit-frame-pointer -fPIC -DPIC -DC_SHARED
> -I"/usr/local/include/chicken"
> # echo $?
> 0
>
> But when I run the gcc command on sendfile with the _XOPEN_SOURCE
> definition it compiles:
>
> # gcc sendfile.c -o sendfile.o -c  -fno-strict-aliasing -fwrapv
> -DHAVE_CHICKEN_CONFIG_H -DC_ENABLE_PTABLES -Os -fomit-frame-pointer
> -fPIC -DPIC -DC_SHARED -I"/usr/local/include/chicken"
> -D_XOPEN_SOURCE=600
>
> Without the definition it fails:
>
> # gcc sendfile.c -o sendfile.o -c  -fno-strict-aliasing -fwrapv
> -DHAVE_CHICKEN_CONFIG_H -DC_ENABLE_PTABLES -Os -fomit-frame-pointer
> -fPIC -DPIC -DC_SHARED -I"/usr/local/include/chicken"
> sendfile.c: In function `stub205':
> sendfile.c:79: error: `POSIX_FADV_SEQUENTIAL' undeclared (first use in
> this function)
> sendfile.c:79: error: (Each undeclared identifier is reported only once
> sendfile.c:79: error: for each function it appears in.)
> sendfile.c:79: error: `POSIX_FADV_NOREUSE' undeclared (first use in
> this function)
>
> The C file starts with the following lines:
>
> #include "chicken.h"
>
> #define _XOPEN_SOURCE 600
> #include<sys/mman.h>
>
> #include<sys/sendfile.h>
> #include<fcntl.h>
>
> So the only difference is that the definition is in front of the
> chicken header include.
>
> Including chicken.h makes the _XOPEN_SOURCE definition useless if it
> is done after the include. Even putting it in the first line of
> sendfile.scm does not help, because chicken.h comes always first in
> the c file.
>
> The chicken header seems to be broken. If I change my standalone probe
> it fails too:
> # cat probe.c
> #include "chicken.h"
> #define _XOPEN_SOURCE 600
> #include<fcntl.h>
> int main(){
>    int fake_fd = 0;
>    posix_fadvise(fake_fd,0,0,POSIX_FADV_SEQUENTIAL);
>    return posix_fadvise(fake_fd,0,0,POSIX_FADV_NOREUSE);
> }
>
> # gcc -c probe.c -fno-strict-aliasing -fwrapv -DHAVE_CHICKEN_CONFIG_H
> -DC_ENABLE_PTABLES -Os -fomit-frame-pointer -fPIC -DPIC -DC_SHARED
> -I"/usr/local/include/chicken"
> probe.c: In function `main':
> probe.c:6: error: `POSIX_FADV_SEQUENTIAL' undeclared (first use in
> this function)
> probe.c:6: error: (Each undeclared identifier is reported only once
> probe.c:6: error: for each function it appears in.)
> probe.c:7: error: `POSIX_FADV_NOREUSE' undeclared (first use in this function)
>
> Hope this helps.