[Boost-users] [boost.build] multiple definitions of symbols at link since revision 49800.

Subject: [Boost-users] [boost.build] multiple definitions of symbols at link since revision 49800.
From: Nigel Dyer (N.P.Dyer_at_[hidden])
Date: 2008-12-10 08:20:18

Hello

I am using the trunk release of boost, and started having problems with 
multiple definitions of symbols during linking (see example linker output 
below).  I can cure the problem by removing the change to 
tools\build\v2\build\generators.jam introduced in revision 49800.

It only seems to occur if the following headers:

#include <boost/test/floating_point_comparison.hpp>
#include <boost/lambda/lambda.hpp>
#include <boost/lambda/bind.hpp>

are included in precompiled headers which are included in cpp files that are 
created by the antlr parser generator.  It occurs on a compilation with 
darwin, but not msvc.

It is unclear whether the generator.jam change has identified a waekness in 
the boost libraries, or there is a problem with the revision 49800 change 
that only surfaces in obscure circumstances, or the change has highlighted a 
problem in my code.  It can be fixed by removing the includes from the 
precompiled header.  I feel this should not be necessary

As a boost newbie it is unclear whether I should I change my code or raise a bug report. I would be grateful for suggestions.

Nigel

Example linker failures.
/usr/libexec/gcc/i686-apple-darwin8/4.0.1/ld: multiple definitions of symbol 
boost::test_tools::(anonymous namespace)::check_is_close

/Volumes/RAID1/xraid/data/bifa/Dev/Projects/Bio/bin/Bio/darwin-4.0.1/release/link-static/libbio.a(BiobaseLexer.o) 
definition of boost::test_tools::(anonymous namespace)::check_is_close 
in section (__DATA,__const)

/Volumes/RAID1/xraid/data/bifa/Dev/Projects/Bio/bin/Bio/darwin-4.0.1/release/link-static/libbio.a(ArrayLexer.o) 
definition of boost::test_tools::(anonymous namespace)::check_is_close 
in section (__DATA,__const)