[PATCH] disable de-duplication of postdeps on Solaris

[Fabian Groffen]

Hi,

I tracked down an issue on Solaris/OpenSolaris/OpenIndiana where C++
libraries built by libtool would cause abort/traps when an exception was
being thrown.

The underlying cause is that the C-library was linked before libgcc,
leading to the C-library generating the abort before libgcc could do
what it was supposed to do.

I only observed this problem on x86-based Solaris, not on Sparc.  The
reason for this follows from what GCC does to link an object.  It
specifies by default -lgcc -lc -lgcc, however on Sparc systems
(unrelated to Solaris) it adds another -lc because libgcc might need the
C-library in turn. [1]

Libtool apparently figures out what libs to link to by watching what the
compiler does.  It applies duplicate elimination on the result of that
(don't know why) causing -lgcc_s -lc -lgcc_s to be turned into -lc
-lgcc_s.  As result, the library aborts on Solaris when it throws an
exception because -lc comes before -lgcc_s.  On Sparc, the result is
-lgcc_s -lc, probably because both were double.

I'm not sure this can be properly fixed by making sure -lgcc_s -lc
remains, since GCC purposely emits the same library multiple times, so I
decided to just disable the duplicate elimination for Solaris.


[1] http://gcc.gnu.org/ml/gcc-patches/2002-04/msg00176.html

-- 
Fabian Groffen
Gentoo on a different level

libtool-2.4.2-solaris-postdeps-no-dedup.patch
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