Re: [jamboost] strange Solaris/gcc problem

From: Philipp Frauenfelder (pfrauenf_at_[hidden])
Date: 2004-07-22 08:35:04

Dear Volodya

On Thu, Jul 22, 2004 at 05:08:34PM +0400, Vladimir Prus wrote:
> > I changed the way I include the dynamic link path of PETSc (an
> > external library from -Wl,-R -Wl,... to -R... and did apply the
> > attached patch to gcc.jam. I am not too much in the internals of
> > linker-compiler issues that I could guess what side-effects this
> > patch is going to have. However, on Linux/gcc it still works and
> > it works on Solaris/gcc.
> 
> So, you've changed -rpath-link to -R. Hmm... I think that's not really right 
> thing. The rpath-link says: when looking for dynamic libraries at link-time, 
> look at this directory. The -R option says: when looking for dynamic library 
> at link-time and *run-time*, look at this directory.

This is the desired behaviour. I have some dynamic libraries
whith which I do not want to spoil LD_LIBRARY_PATH. Therefore, I
use -R. And also for the dynamic libs generated by the Boost
controlled build, I want to have the correct libs at runtime. I
see that Boost is manipulating LD_LIBRARY_PATH before a test run
(with unit-test), but as a user of an application, I do not want
to do this.

> The reason why the patch is problematic is this. You build an application 
> which uses a library, and install both to /usr/. However, because of the -R 
> option, the application the use the library which is installed in your build 
> tree, not the one in /usr/lib, which is clearly not desirable.

Correct. For something to be installed, -R is not allowed.

> The strange thing is that there are some V2 users on Solaris, and they did not 
> report any problems. Also, you say that copy-pasting the linker command that 
> g++ issues with "-v" works, which is extra strange --- Aha... somehow, when 
> you invoke it manually, GNU ld is used, not solaris one.

Correct.

> Maybe, the problem is that your's Solaris ld is outdated or something, and you 
> should be using GNU one. I wonder how to force using GNU ld, though.

IIRC, this is a compile time option of gcc. Additionally, IIRC,
gcc people advokate the use of the Solaris linker instead of GNU
ld:
http://gcc.gnu.org/install/specific.html#_002a_002d_002a_002dsolaris2_002a
Aha, this only holds for older GNU ld. We have exactly GNU ld
2.11.2 on our Solaris platform. Maybe we should switch to the
newer release. I will look into this.

Regards
-- 
Philipp | work: pfrauenf_at_[hidden] [phone]
Frauenfelder | home: pfrauenf_at_[hidden] [phone]
[PGP] | http://www.math.ethz.ch/~pfrauenf/
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