Linker error when using Spirit Classic

[janis.ruksans@…]

After upgrading to Boost 1.60, my project using Spirit Classic no longer builds, failing with a linker error complaining about undefined references to boost::system::generic_category() and boost::system::system_category().

The minimal test case is:

#include <boost/spirit/include/classic.hpp>

int
main (int argc, char ** argv)
{
   return 0;
}

which gives results in the following compiler output:

$ g++ -Wall test.cxx
/tmp/ccpjbwj6.o: In function `__static_initialization_and_destruction_0(int, int)':
test.cxx:(.text+0x23f): undefined reference to `boost::system::generic_category()'
test.cxx:(.text+0x249): undefined reference to `boost::system::generic_category()'
test.cxx:(.text+0x253): undefined reference to `boost::system::system_category()'
collect2: error: ld returned 1 exit status

[janis.ruksans@…]

A workaround is to define BOOST_SYSTEM_NO_DEPRECATED before including any Spirit headers.

[Joel de Guzman]

I don't think this is a Spirit bug. Is boost::system advertised to be header only?

[janis.ruksans@…]

Boost.System isn't, but Spirit is, right? At least it is not listed among the libraries that are not header only here.

[Nikita Kniazev <nok.raven@…>]

The first thing I should say: Boost 1.60 is pretty old (released 2+ years ago).

Spirit does not use Boost.System directly, but I suspect it is used by Boost.Thread that may be included even if BOOST_SPIRIT_THREADSAFE is not defined. Please try to apply manually ​https://github.com/boostorg/spirit/pull/323.patch or better grab the latest Spirit from the git develop branch.

The simplest solution for you is to add -lboost_system to you compile command.

[Nikita Kniazev <nok.raven@…>]

The boost/spirit/home/classic/core/non_terminal/impl/static.hpp might still be a problem even on the latest Spirit. Try to also apply the attached patch ​`thread_unsafe.patch​`.

[Nikita Kniazev <nok.raven@…>]

Oh, I missed that boost/spirit/home/classic/core/non_terminal/impl/static.hpp will be included only if BOOST_SPIRIT_THREADSAFE is defined. So the problem should have been fixed in ​PR 323.