* Regarding FD_ZERO compilation warning
@ 2022-06-20 3:47 Reddy K
2022-06-20 7:31 ` Florian Weimer
0 siblings, 1 reply; 6+ messages in thread
From: Reddy K @ 2022-06-20 3:47 UTC (permalink / raw)
To: libc-help
HI Team,
I have enabled all compilation flags and did "make" build. I got the
warning below and have tried to include required header files ( select.h,
time.h, types.h and unistd.h) but still it shows the warning. So can you
please help me to fix this.
ds_locator.c:930:2: warning: traditional C rejects string constant
concatenation [-Wtraditional]
FD_ZERO(&readfds);
I am pasting the code snippet below to understand how variable readfds
define.
-----------------------------
fd_set readfds;
FD_ZERO(&readfds);
----------------------------
Thanks & Regards
Haritha
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Regarding FD_ZERO compilation warning
2022-06-20 3:47 Regarding FD_ZERO compilation warning Reddy K
@ 2022-06-20 7:31 ` Florian Weimer
2022-06-20 11:04 ` Reddy K
0 siblings, 1 reply; 6+ messages in thread
From: Florian Weimer @ 2022-06-20 7:31 UTC (permalink / raw)
To: Reddy K via Libc-help; +Cc: Reddy K
* Reddy K. via Libc-help:
> I have enabled all compilation flags and did "make" build. I got the
> warning below and have tried to include required header files ( select.h,
> time.h, types.h and unistd.h) but still it shows the warning. So can you
> please help me to fix this.
>
> ds_locator.c:930:2: warning: traditional C rejects string constant
> concatenation [-Wtraditional]
> FD_ZERO(&readfds);
>
> I am pasting the code snippet below to understand how variable readfds
> define.
> -----------------------------
> fd_set readfds;
> FD_ZERO(&readfds);
>
> ----------------------------
I don't see how glibc's FD_ZERO can trigger this compiler warning.
I suggest you generate preprocessed sources with gcc --save-temps or gcc
-E, and show us the macro expansion.
In general, there is no expectation that the glibc headers are clean
with -Wtraditional, quite the opposite actually. We require an ISO C
compiler.
Thanks,
Florian
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Regarding FD_ZERO compilation warning
2022-06-20 7:31 ` Florian Weimer
@ 2022-06-20 11:04 ` Reddy K
2022-06-20 11:09 ` Florian Weimer
0 siblings, 1 reply; 6+ messages in thread
From: Reddy K @ 2022-06-20 11:04 UTC (permalink / raw)
To: Florian Weimer; +Cc: Reddy K via Libc-help
Hi Florian,
Thank you very much for your help.
As you suggested, I have generated preprocessed sources with gcc -E.
Please find macro expansion below.
-------------------
do { int __d0, __d1; __asm__ __volatile__ ("cld; rep; " "stosq" : "=c"
(__d0), "=D" (__d1) : "a" (0), "0" (sizeof (fd_set) / sizeof (__fd_mask)),
"1" (&((&readfds)->__fds_bits)[0]) : "memory"); } while (0);
---------------------
thanks & regards,
Haritha
On Mon, Jun 20, 2022 at 1:01 PM Florian Weimer <fweimer@redhat.com> wrote:
> * Reddy K. via Libc-help:
>
> > I have enabled all compilation flags and did "make" build. I got the
> > warning below and have tried to include required header files ( select.h,
> > time.h, types.h and unistd.h) but still it shows the warning. So can you
> > please help me to fix this.
> >
> > ds_locator.c:930:2: warning: traditional C rejects string constant
> > concatenation [-Wtraditional]
> > FD_ZERO(&readfds);
> >
> > I am pasting the code snippet below to understand how variable readfds
> > define.
> > -----------------------------
> > fd_set readfds;
> > FD_ZERO(&readfds);
> >
> > ----------------------------
>
> I don't see how glibc's FD_ZERO can trigger this compiler warning.
>
> I suggest you generate preprocessed sources with gcc --save-temps or gcc
> -E, and show us the macro expansion.
>
> In general, there is no expectation that the glibc headers are clean
> with -Wtraditional, quite the opposite actually. We require an ISO C
> compiler.
>
> Thanks,
> Florian
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Regarding FD_ZERO compilation warning
2022-06-20 11:04 ` Reddy K
@ 2022-06-20 11:09 ` Florian Weimer
2022-06-20 11:23 ` Reddy K
0 siblings, 1 reply; 6+ messages in thread
From: Florian Weimer @ 2022-06-20 11:09 UTC (permalink / raw)
To: Reddy K; +Cc: Reddy K via Libc-help
* Reddy K.:
> Hi Florian,
> Thank you very much for your help.
>
> As you suggested, I have generated preprocessed sources with gcc -E. Please find macro
> expansion below.
> -------------------
> do { int __d0, __d1; __asm__ __volatile__ ("cld; rep; " "stosq" : "=c" (__d0), "=D" (__d1) :
> "a" (0), "0" (sizeof (fd_set) / sizeof (__fd_mask)), "1" (&((&readfds)->__fds_bits)[0]) :
> "memory"); } while (0);
> ---------------------
Ahh, that code was removed upstream in:
commit 3430ed09d3bef58dbf3fe18d87716236883599d8
Author: Florian Weimer <fweimer@redhat.com>
Date: Sun Feb 9 11:01:39 2020 +0100
x86: Remove <bits/select.h> and use the generic version
Particularly on CPUs without ERMS, the string instructions are slow,
so it is unclear whether this architecture-specific implementation is
in fact an optimization.
If you need this backported in a distribution build, please contact your
distribution about backporting the change.
Thanks,
Florian
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Regarding FD_ZERO compilation warning
2022-06-20 11:09 ` Florian Weimer
@ 2022-06-20 11:23 ` Reddy K
2022-06-20 11:26 ` Florian Weimer
0 siblings, 1 reply; 6+ messages in thread
From: Reddy K @ 2022-06-20 11:23 UTC (permalink / raw)
To: Florian Weimer; +Cc: Reddy K via Libc-help
Hi Florian,
I am including the below header files.
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/select.h>
Thanks & Regards
Haritha
On Mon, Jun 20, 2022 at 4:39 PM Florian Weimer <fweimer@redhat.com> wrote:
> * Reddy K.:
>
> > Hi Florian,
> > Thank you very much for your help.
> >
> > As you suggested, I have generated preprocessed sources with gcc -E.
> Please find macro
> > expansion below.
> > -------------------
> > do { int __d0, __d1; __asm__ __volatile__ ("cld; rep; " "stosq" : "=c"
> (__d0), "=D" (__d1) :
> > "a" (0), "0" (sizeof (fd_set) / sizeof (__fd_mask)), "1"
> (&((&readfds)->__fds_bits)[0]) :
> > "memory"); } while (0);
> > ---------------------
>
> Ahh, that code was removed upstream in:
>
> commit 3430ed09d3bef58dbf3fe18d87716236883599d8
> Author: Florian Weimer <fweimer@redhat.com>
> Date: Sun Feb 9 11:01:39 2020 +0100
>
> x86: Remove <bits/select.h> and use the generic version
>
> Particularly on CPUs without ERMS, the string instructions are slow,
> so it is unclear whether this architecture-specific implementation is
> in fact an optimization.
>
> If you need this backported in a distribution build, please contact your
> distribution about backporting the change.
>
> Thanks,
> Florian
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Regarding FD_ZERO compilation warning
2022-06-20 11:23 ` Reddy K
@ 2022-06-20 11:26 ` Florian Weimer
0 siblings, 0 replies; 6+ messages in thread
From: Florian Weimer @ 2022-06-20 11:26 UTC (permalink / raw)
To: Reddy K; +Cc: Reddy K via Libc-help
* Reddy K.:
> I am including the below header files.
>
> #include <sys/types.h>
> #include <sys/socket.h>
> #include <unistd.h>
> #include <sys/time.h>
> #include <sys/select.h>
I guessed as much. Given that the issue is already fixed upstream,
you really need to contact your distribution regarding this issue.
Thanks,
Florian
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-06-20 11:26 UTC | newest]
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2022-06-20 3:47 Regarding FD_ZERO compilation warning Reddy K
2022-06-20 7:31 ` Florian Weimer
2022-06-20 11:04 ` Reddy K
2022-06-20 11:09 ` Florian Weimer
2022-06-20 11:23 ` Reddy K
2022-06-20 11:26 ` Florian Weimer
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