[Bug libgcc/56482] New: missing -lpthread in configure when checking for pthreads_num_processors_np

[Bug libgcc/56482] New: missing -lpthread in configure when checking for pthreads_num_processors_np

[k2k at narod dot ru]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56482

             Bug #: 56482
           Summary: missing -lpthread in configure when checking for
                    pthreads_num_processors_np
    Classification: Unclassified
           Product: gcc
           Version: 4.7.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libgcc
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: k2k@narod.ru
              Host: mingw32
            Target: mingw32, mingw32-w64


>From configure.log:

configure:20205: checking for pthreads_num_processors_np
configure:20244:  /dvlp/packages/gcc/build/4.7.2-i686-w64-mingw32/./gcc/xgcc
-shared-libgcc -B/dvlp/packages/gcc/build/4.7.2-i686-w64-mingw32/./gcc
-nostdinc++
-L/dvlp/packages/gcc/build/4.7.2-i686-w64-mingw32/i686-w64-mingw32/libstdc++-v3/src
-L/dvlp/packages/gcc/build/4.7.2-i686-w64-mingw32/i686-w64-mingw32/libstdc++-v3/src/.libs
-L/dvlp/mingw-w64-i686/i686-w64-mingw32/lib -L/dvlp/mingw-w64-i686/mingw/lib
-isystem /dvlp/mingw-w64-i686/i686-w64-mingw32/include -isystem
/dvlp/mingw-w64-i686/mingw/include -B/dvlp/mingw-w64-i686/i686-w64-mingw32/bin/
-B/dvlp/mingw-w64-i686/i686-w64-mingw32/lib/ -isystem
/dvlp/mingw-w64-i686/i686-w64-mingw32/include -isystem
/dvlp/mingw-w64-i686/i686-w64-mingw32/sys-include
-L/dvlp/packages/gcc/build/4.7.2-i686-w64-mingw32/./ld    -o conftest.exe -g
-O2 -fno-exceptions   conftest.cpp  >&5
C:\Users\Karlson\AppData\Local\Temp\ccd7ltCc.o: In function `main':
T:\dvlp\packages\gcc\build\4.7.2-i686-w64-mingw32\i686-w64-mingw32\libstdc++-v3/conftest.cpp:76:
undefined reference to `_imp__pthread_num_processors_np'
collect2.exe: error: ld returned 1 exit status
configure:20244: $? = 1
configure: failed program was:
....


Configure didn't try with '-lpthread' flag, so result can't be linked with
libpthread.

[Bug libstdc++/56482] missing -lpthread in configure when checking for pthreads_num_processors_np

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56482

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-02-28
     Ever Confirmed|0                           |1

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2013-02-28 12:27:09 UTC ---
Those tests possibly shouldn't be link tests anyway, just compile tests.

Note to self, the comment on GLIBCXX_CHECK_SYSCTL_HW_NCPU wrongly mentions
<pthread.h>

[Bug libstdc++/56482] missing -lpthread in configure when checking for pthreads_num_processors_np

[k2k at narod dot ru]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56482

--- Comment #2 from Karlson2k <k2k at narod dot ru> 2013-02-28 14:08:02 UTC ---
If it'll be only compile test, how result can be linked when dependence on
libpthread will be unknown?

[Bug libstdc++/56482] missing -lpthread in configure when checking for pthreads_num_processors_np

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56482

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> 2013-02-28 14:27:48 UTC ---
The function is only used in src/c++11/thread.cc which will already be linked
to libpthread.so if needed.

[Bug libstdc++/56482] missing -lpthread in configure when checking for pthreads_num_processors_np

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56482

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> 2013-02-28 14:29:10 UTC ---
Actually that might not be true ... the other functions used in thread.cc could
be linked to weak symbols.

[Bug libstdc++/56482] missing -lpthread in configure when checking for pthreads_num_processors_np

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56482

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Created attachment 32993
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=32993&action=edit
change GCC_TRY_COMPILE_OR_LINK test to AC_TRY_COMPILE

Does this patch (against trunk) solve the problem?

[Bug libstdc++/56482] missing -lpthread in configure when checking for pthreads_num_processors_np

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56482

Eric Gallager <egallager at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |WAITING
                 CC|                            |egallager at gcc dot gnu.org

--- Comment #6 from Eric Gallager <egallager at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #5)
> Created attachment 32993 [details]
> change GCC_TRY_COMPILE_OR_LINK test to AC_TRY_COMPILE
> 
> Does this patch (against trunk) solve the problem?

marking this as WAITING on a reply from the reporter

[Bug libstdc++/56482] missing -lpthread in configure when checking for pthreads_num_processors_np

[k2k at narod dot ru]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56482

--- Comment #7 from Karlson2k <k2k at narod dot ru> ---
Sorry, I can't check it, my build environment was lost a long time ago.