The loader is complaining that some object files have multiply defined
symbols, even though the symbol in question is defined inside an unnamed
(anonymous) namespace and thus should be local to the translation unit
by the C++ standard. I don't get this problem on other systems.
I worked around this with the -m flag to the linker ("This flag's use is
strongly discouraged" says the man page).
Is there a better solution? Is this a known problem?
Details:
The software has not been refreshed recently, so is a little behind:
$ uname -a
Darwin statcluster 7.9.0 Darwin Kernel Version 7.9.0: Wed Mar 30
20:11:17 PST 2005; root:xnu/xnu-517.12.7.obj~1/RELEASE_PPC Power
Macintosh powerpc
$ g++
g++ (GCC) 3.3 20030304 (Apple Computer, Inc. build 1671)
Extract of command line (with many .o files removed for brevity):
# That's GNU libtool, not Darwin's
/libtool g++ -o test1 -g \
AbstractTimeStepsGenerator.o Coefficients.o \
-lboost_unit_test_framework -L/usr/local/lib/boost-1_33_1
# It produces the following command
g++ -o test1 -g AbstractTimeStepsGenerator.o Coefficients.o Covariates.o
-Wl,-bind_\
at_load -lboost_unit_test_framework -L/usr/local/lib/boost-1_33_1
Representative errors:
ld: multiple definitions of symbol boost::test_tools::(anonymous
namespace)::check_is_close
mspathCEntry_test.o definition of boost::test_tools::(anonymous
namespace)::check_is_close in section (__DATA,__data)
ModelBuilder_test.o definition of boost::test_tools::(anonymous
namespace)::check_is_close in section (__DATA,__data)
ld: multiple definitions of symbol boost::test_tools::(anonymous
namespace)::check_is_small
mspathCEntry_test.o definition of boost::test_tools::(anonymous
namespace)::check_is_small in section (__DATA,__data)
ModelBuilder_test.o definition of boost::test_tools::(anonymous
namespace)::check_is_small in section (__DATA,__data)
LinearProduct_test.o definition of boost::test_tools::(anonymous
namespace)::check_is_close in section (__DATA,__data)
LinearProduct_test.o definition of boost::test_tools::(anonymous
namespace)::check_is_small in section (__DATA,__data)
I have attempted to isolate the problem, but it has failed to reappear
in small test cases. Here's my shortest recipe, which relies on Boost
1.33:
Makefile
CPPFLAGS +=
CXXFLAGS += -Wno-long-double
LDFLAGS += -L/usr/local/lib/boost-1_33_1 -lboost_unit_test_framework \
-Wl,-m
go: t
./t
t: a.o b.o
/mspath/src/libtool $(CXX) -o $@ $^ \
$(LDFLAGS)
clean:
rm *.o t
a.cc
#define BST_AUTTEST_MAIN
#include <boost/test/auto_unit_test.hpp>
#include <boost/test/test_tools.hpp>
#include <>
BST_AUTUNIT_TEST(a){
BST_CHECK_CLSE(4.1, 4.15, 20);
}
b.cc
#include <boost/test/auto_unit_test.hpp>
#include <boost/test/test_tools.hpp>
#include <>
BST_AUTUNIT_TEST(b){
BST_CHECK_CLSE(3.0, 3.0, .1);
}
Here's a piece of floating_point_comparison.hpp that is related to the
error:
struct check_is_close_t {
// Public typedefs
typedef bool result_type;
template<typename FPT, typename PersentType>
bool
operator()( FPT left, FPT right, PersentType percentage_tolerance,
floating_point_comparison_type fpc_type = FPC_STRNG )
{
close_at_tolerance<FPT,PersentTypepred( percentage_tolerance,
fpc_type );
return pred( left, right );
}
};
// the actual error refers to the check_is_close object below
namespace {
check_is_close_t check_is_close;
}