LNK2019 when including asio headers, solution gene

问题:

I am trying to port a big project from gcc (Linux) to msvc (windows), using cmake and boost libraries.

The project compile and runs fine for gcc but on msvc it returns the following error:

Dyna.obj : error LNK2019: unresolved external symbol "void __cdecl boost::throw_exception(class std::exception const &)" (?throw_exception@boost@@YAXABVexception@std@@@Z) referenced in function "void __cdecl boost::asio::detail::do_throw_error(class boost::system::error_code const &,char const *)" (?do_throw_error@detail@asio@boost@@YAXABVerror_code@system@3@PBD@Z)

I tried running a simple project using boost asio and it worked, which teorethically excludes boost build problems.

The CMakeLists.txt is as follows: (separated the parts of interest)

    .
    .
    .
IF(WIN32)
          # Flags para garantir a compilação em windows
          SET(CMAKE_CXX_COMPILER icpl)
          SET(TPN_WIN32 "/D WIN32")
          SET(TPN_WIN32_LIB ws2_32.lib odbc32.lib odbccp32.lib)
          SET(CMAKE_EXE_LINKER_FLAGS /NODEFAULTLIB:LIBC;LIBCMT)

    ENDIF(WIN32)

    # Comando para se livrar de warning sobre o caminho da library pthread
    IF(COMMAND cmake_policy)
      cmake_policy(SET CMP0003 NEW)
    ENDIF(COMMAND cmake_policy)

    # Configuracao do TPN REALTIME
    # === inicio ===
    IF (REALTIME_YES)
      MESSAGE ("[TPN] REALTIME ENABLED")
      set(Boost_ADDITIONAL_VERSIONS "1.45.0")
      set(Boost_USE_MULTITHREAD ON)
      set(Boost_USE_STATIC_LIBS ON)
      FIND_PACKAGE( Boost "1.45.0" COMPONENTS system filesystem serialization program_options regex thread date_time REQUIRED)
      FIND_PACKAGE( Threads REQUIRED )

      set(HYDRO_CXX_FLAGS "-DREALTIME -DJOYSTICK")
      set(HYDRO_CXX_LFLAGS ${Boost_LIBRARIES})

      INCLUDE_DIRECTORIES(hydro)


       INCLUDE_DIRECTORIES(${Boost_INCLUDE_DIR})
        ENDIF (REALTIME_YES)
        # ===  final ===
        .
        .
        .

    TARGET_LINK_LIBRARIES(Dyna
      tpn
      preadyn
      ${WHERE_PREA3D}
      ${WHERE_WAMIT_IO}
      ${WHERE_WAMIT_CONVERTER}
      ${WHERE_TECLINE}
      ${HYDRO_CXX_LFLAGS}
      ${TPN_WIN32_LIB}
    )

Thanks in advance

回答1:

Try to add the flag "/EHsc" into your TPN_WIN32 variable in cmake. It seems that MSVC is not throwing exceptions and you need to enable it in your vcproj.

回答2:

In my case, the /EHsc flag did not work. Turned out that BOOST_NO_EXCEPTIONS was defined so the compiler was searching for the "user defined" (as in boost/throw_exception.hpp) function.

Therefore, a quick fix is to write your favorite boost::throw_exception() function:

namespace boost
{
#ifdef BOOST_NO_EXCEPTIONS
void throw_exception( std::exception const & e ){
    throw 11; // or whatever
};
#endif
}// namespace boost

回答3:

When running on windows you need (by default) to link to boost.system and boost.regex

As it says here:

Note With MSVC or Borland C++ you may want to add -DBOOST_DATE_TIME_NO_LIB and -DBOOST_REGEX_NO_LIB to your project settings to disable autolinking of the Boost.Date_Time and Boost.Regex libraries respectively. Alternatively, you may choose to build these libraries and link to them.

If you don't want to link to other boost libraries then you can use the identical (non-boost) asio library from here.

In terms of your CMakeLists.txt file, you want a line such as

target_link_libraries (your_application ${Boost_LIBRARIES})

to actually link the library.

EDIT: also, have a look at How to link against boost.system with cmake, it could be that you have to specify the individual boost libraries specifically rather than ${Boost_LIBRARIES}

回答4:

Looks like, to be linking compatible, binary must have same structure exception handling enablement option. MSVC standard library implementation use structured exception handling option on. Looks like this is why boost::system also uses this on. You might see corresponding warnings telling you to add structure exception handling.

IF(MSVC)
    ADD_DEFINITIONS("/EHsc")
ENDIF(MSVC)