[Bug libgomp/28482] New: Cannot use libgomp in shared library

[Bug libgomp/28482] New: Cannot use libgomp in shared library

[mozilla at weilbacher dot org]

I made some tests using gcc version 4.2.0 20060708 (experimental) to see if I
can make use of the OpenMP feature and libgomp in my data processing
environment. This environment runs on Unix systems (here: Linux) and consists
of a main program and several .so plugins that do the actual work. If I use
libgomp I cannot load these plugins any more because libgomp is built with "-z
nodlopen". From libgomp/configure.tgt:

   # Optimize TLS usage by avoiding the overhead of dynamic allocation.
   # This does require that the library be present during process
   # startup, so mark the library as not to be dlopened.
   if test $have_tls = yes && test "$with_gnu_ld" = "yes"; then
           XCFLAGS="${XCFLAGS} -ftls-model=initial-exec"
           XLDFLAGS="${XLDFLAGS} -Wl,-z,nodlopen"
   fi

I guess that for some uses this really makes sense but I didn't find this
documented anywhere and had to post to newsgroups to get someone to help me
find this.

I suggest you remove this and add a configure switch instead.


-- 
           Summary: Cannot use libgomp in shared library
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libgomp
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: mozilla at weilbacher dot org
 GCC build triplet: x86_64-unknown-linux-gnu
  GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28482

[Bug libgomp/28482] Cannot use libgomp in shared library

[rguenth at gcc dot gnu dot org]

------- Comment #1 from rguenth at gcc dot gnu dot org  2006-07-25 15:48 -------
You can link your main program against libgomp.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28482

[Bug libgomp/28482] Cannot use libgomp in shared library

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2006-07-25 15:53 -------
(In reply to comment #1)
> You can link your main program against libgomp.

If you controll your main program, you can, but for an example a pluggin into
say Photoshop, you cannot.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2006-07-25 15:53:30
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28482

[Bug libgomp/28482] Cannot use libgomp in shared library

[jakub at gcc dot gnu dot org]

------- Comment #3 from jakub at gcc dot gnu dot org  2007-05-04 20:21 -------
Subject: Bug 28482

Author: jakub
Date: Fri May  4 19:21:18 2007
New Revision: 124445

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=124445
Log:
        PR libgomp/28482
        * configure.tgt: Don't link with -Wl,-z,nodlopen even on Linux.

Modified:
    trunk/libgomp/ChangeLog
    trunk/libgomp/configure.tgt


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28482

[Bug libgomp/28482] Cannot use libgomp in shared library

[mozilla at weilbacher dot org]

------- Comment #4 from mozilla at weilbacher dot org  2007-05-10 09:44 -------
Thanks Jakub. I downloaded snapshot "4.3.0 20070503 (experimental)" (the
gcc-4.3-20070504.tar.bz2 package) and confirmed that the issue with my data
processing plugins is fixed when compiling with this gcc and libgomp.

Not sure what the GCC policy is for marking bugs fixed but I am happy. :-)
Any chance to get this into 4.2 (or one of the later 4.2.x releases)?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28482

[Bug libgomp/28482] Cannot use libgomp in shared library

[tiago at forked dot de]

------- Comment #5 from tiago at forked dot de  2007-06-15 15:48 -------
The above changes still don't solve the problem for me, since I still can't
load a  python module which is dynamically linked to libgomp (from GCC 4.2.0).
Below, graph-tool is a python program and libgraph_tool.so is a dynamic library
linked with libgomp:

Traceback (most recent call last):
  File "./graph-tool", line 22, in ?
    from libgraph_tool import *
ImportError: /home/count0/stuff/misc/src/gcc-root/lib/libgomp.so.1: cannot
allocate memory in static TLS block

Only when I also remove the line 
   XCFLAGS="${XCFLAGS} -ftls-model=initial-exec"
from configure.tgt, does the module get loaded properly.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28482

[Bug libgomp/28482] Cannot use libgomp in shared library

[aldot at gcc dot gnu dot org]

-- 

aldot at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.2.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28482

[Bug libgomp/28482] Cannot use libgomp in shared library

[mmitchel at gcc dot gnu dot org]

------- Comment #6 from mmitchel at gcc dot gnu dot org  2007-10-09 19:21 -------
Change target milestone to 4.2.3, as 4.2.2 has been released.


-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.2.2                       |4.2.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28482

[Bug libgomp/28482] Cannot use libgomp in shared library

[tiago at forked dot de]

------- Comment #7 from tiago at forked dot de  2007-12-18 00:14 -------
Created an attachment (id=14788)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=14788&action=view)
trivial patch that fixes the problem

This is just a ping... Any chance of getting this fixed in the next release? It
seems so simple. :) Attached is a patch that fixes it completely for me.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28482

[Bug libgomp/28482] Cannot use libgomp in shared library

[peter dot waller at gmail dot com]

------- Comment #8 from peter dot waller at gmail dot com  2008-01-23 21:15 -------
Still no sign of 4.2 fix?


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peter dot waller at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |peter dot waller at gmail
                   |                            |dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28482

[Bug libgomp/28482] Cannot use libgomp in shared library

[jsm28 at gcc dot gnu dot org]

------- Comment #9 from jsm28 at gcc dot gnu dot org  2008-02-01 16:53 -------
4.2.3 is being released now, changing milestones of open bugs to 4.2.4.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.2.3                       |4.2.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28482

[Bug libgomp/28482] Cannot use libgomp in shared library

[ilmarw at simula dot no]

------- Comment #10 from ilmarw at simula dot no  2008-02-06 15:37 -------
Can confirm this on 32-bit platform as well:
Linux multiboot 2.6.22-14-generic #1 SMP Fri Feb 1 04:59:50 UTC 2008 i686
GNU/Linux

gcc version 4.2.1 (Ubuntu 4.2.1-5ubuntu4)

I recompiled after patching as suggested above, successfully.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28482

[Bug libgomp/28482] Cannot use libgomp in shared library

[ilmarw at simula dot no]

------- Comment #11 from ilmarw at simula dot no  2008-04-29 13:36 -------
Fixed in version 4.3.0.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28482

[Bug libgomp/28482] Cannot use libgomp in shared library

[jsm28 at gcc dot gnu dot org]

------- Comment #12 from jsm28 at gcc dot gnu dot org  2008-05-19 20:22 -------
4.2.4 is being released, changing milestones to 4.2.5.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.2.4                       |4.2.5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28482

[Bug libgomp/28482] Cannot use libgomp in shared library

[jsm28 at gcc dot gnu dot org]

------- Comment #13 from jsm28 at gcc dot gnu dot org  2008-07-04 19:47 -------
No indication that this is a regression; marking fixed.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|4.2.5                       |4.3.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28482