#77 Cant compile with gcc 11.2.1 - on Gentoo

[Psilovybin]

here's the error I get a few minutes into compilation:

make[1]: Leaving directory '/home/doc/Downloads/syncterm-20220104/src/hash'
Linking gcc.linux.x64.exe.debug/syncterm
/usr/lib/gcc/x86_64-pc-linux-gnu/11.2.1/../../../../x86_64-pc-linux-gnu/bin/ld: /home/doc/Downloads/syncterm-20220104/src/../3rdp/gcc.linux.x64.debug/cl/libcl.a(sendmsg.o): in function `waitForObject':
sendmsg.c:(.text+0x10c6): undefined reference to `pthread_yield'
collect2: error: ld returned 1 exit status
make: *** [GNUmakefile:111: gcc.linux.x64.exe.debug/syncterm] Error 1

[Stephen James Hurd]

Could you rebuild with VERBOSE=1 passed on the make command-line and provide the ld command used? The manpage for pthread_yield on Gentoo may help as well.

pthread_yield() is a terrible non-portable function, but it's always been available on Linux as far as I've seen.

[Psilovybin]

man page for pthread_yield shows this":

VERSIONS
Since glibc 2.34, this function is marked as deprecated.

Full Build Log at https://pastebin.com/V0Pxyqk3

[Psilovybin]

Ah, just realized i could upload attachment

[chrll]

I also have this problem, but I'm using Arch Linux. I'm including my log.

(my man page also says "Since glibc 2.34, this function is marked as deprecated.")

[Aaron Brown]

Also failing on Fedora35

[Anonymous]

Failing here too, also on Arch.

[Paul Dufresne]

I believe the problem is that for Linux with GNU, PTHREAD_YIELD is wrongly defined as pthread_yield, but man pthread_yield say it is deprecated, and sched_yield() should be used instead. As explained in the thread.h of cl (cryptlib), sched_yield is the right choice after the standard confusion (two parralel versions, they were unsure which would be standardized).
/syncterm-1.1/3rdp/src/cl/kernel/thread.h:3015 have:

else

#if defined( linux ) && !defined( __USE_GNU )
void pthread_yield( void );
#endif / Present but not prototyped unless GNU extensions are enabled /
#define THREAD_YIELD() pthread_yield()

should be #define THREAD_YIELD sched_yield()

I believe some compatibility define has been removed in Ubuntu lately:
https://sourceware.org/git/?p=glibc.git;a=commit;h=c2fd60a5861efef48252f5cc7efc70e1d8a0da9a
and so in Ubuntu 22.04 it does not compile anymore.

That said, I tried to change the file directly, and remove syncterm-1.1-src/syncterm-1.1/3rdp/gcc.linux.x64.debug/cl/libcl.a, but that does not work, because I believe the .zip is redecompress and so a new patch file must be made.

[Paul Dufresne]

cryptlib 3.4.6 (release candidate) have:

elif defined( linux )

/ Under newer versions of Linux, once they got the threading model sorted
out via the NPTL vs. earlier LinuxThreads and others, sched_yield() ==
pthread_yield() (that is, pthread_yield() is just a wrapper for
sched_yield() in pthread_yield.c). In addition some newer distros
mangle the wrapper in glibc so that linking fails if we use
pthread_yield() but not if we use sched_yield(). To deal with this, if
the OS version is new enough that threading is standardised via NPTL we
use sched_yield() rather than pthread_yield() /
#if ( OSVERSION > 3 )
#include <sched.h>
#define THREAD_YIELD() sched_yield()
#else
#ifndef __USE_GNU
void pthread_yield( void );
#endif / Present but not prototyped unless GNU extensions are enabled /
#define THREAD_YIELD() pthread_yield()
#endif / Linux > 3.x /</sched.h>

else

#define THREAD_YIELD() pthread_yield()

endif / Not-very-portable Posix portability /

I tried to replace the zip file by the new version but then some patch does not apply anymore.

[Paul Dufresne]

I was not using git clone https://gitlab.synchro.net/main/sbbs.git
and it seems fixed there (I change hard disk since yesterday, but using Xubuntu 22.04, yesterday Ubuntu 22.04). I looked at the modified thread.h file and it seems ok:

paul@kasparno:~/sbbs/3rdp/build$ git log cl-linux-yield.patch
commit 53264f2b0f20d28508ecdc611b7dfba385e27350
Author: Rob Swindell rob@synchro.net
Date: Tue Oct 19 12:55:56 2021 -0700

Use shed_yield() instead of pthread_yield() on Linux

Per https://man7.org/linux/man-pages/man3/pthread_yield.3.html
        This call is nonstandard, but present on several other systems.
        Use the standardized sched_yield(2) instead.

Should fix #299.