boost log - undefined reference when using a global logger

Question

I have successfully built a boost example rotating_file (boost 1.63) using my own cmake file instead of jamfile. Then I have add following modification:

#include <boost/log/sources/global_logger_storage.hpp>
...
//before main
BOOST_LOG_GLOBAL_LOGGER(my_logger, src::logger)
...
//src::logger lg;
src::logger& lg = my_logger::get();

A program also contains this line:

#define BOOST_ALL_DYN_LINK

Here are cmake libs:

target_link_libraries(test "libboost_log.so"
                           "libboost_log_setup.so"
                           "libboost_date_time.so"
                           "libboost_filesystem.so"
                           "libboost_system.so"
                           "libboost_thread.so")

This line:

src::logger& lg = my_logger::get();

generates:

global_logger_storage.hpp:154: error: undefined reference to `my_logger::construct_logger()'

What is wrong ?

Edit

I add sink and other attributes this way:

logging::core::get()->add_sink(sink);
logging::core::get()->add_global_attribute("TimeStamp", attrs::local_clock());
logging::core::get()->add_global_attribute("RecordID", attrs::counter< unsigned int >());

so at the end of the BOOST_LOG_GLOBAL_LOGGER_INIT I just add:

src::logger logger;
return logger;

It works.

Answer 1

You need a call to BOOST_LOG_GLOBAL_LOGGER_INIT. In one project I have the following in a header:

// register a global logger
BOOST_LOG_GLOBAL_LOGGER(logger, boost::log::sources::severity_logger_mt<boost::log::trivial::severity_level>)

In the source file I have this:

BOOST_LOG_GLOBAL_LOGGER_INIT(logger, src::severity_logger_mt) {
    src::severity_logger_mt<boost::log::trivial::severity_level> logger;

    // add attributes
    logger.add_attribute("LineID", attrs::counter<unsigned int>(1));    // lines are sequentially numbered
    logger.add_attribute("TimeStamp", attrs::local_clock());             // each log line gets a timestamp

    return logger;
}

When I comment out the BOOST_LOG_GLOBAL_LOGGER_INIT, I get the same error as you do. My powers of deduction tell me that BOOST_LOG_GLOBAL_LOGGER_INIT provides the definition that you (we) need.