嘗試將Boost與CMake鏈接時出現LNK2019錯誤

Question

我正在制作我的第一個將CMake用於構建系統的項目。 我還決定這是一個嘗試將boost納入我的c ++技能的好時機。 我已經閱讀了文檔並瀏覽了SO和其他網站，但我陷入了LNK2019錯誤。 我在這里讀到這可能是由於32/64位項目/ boost庫不匹配。 但是，我有足夠的信心建立正確的庫。 我將在下面發布相關的cmake，代碼，錯誤和命令

生成命令

b2.exe -a variant=debug,release link=shared,static threading=multi address-model=64

生成項目命令

cmake .. -G"Visual Studio 12 Win64"

CMake文件

cmake_minimum_required (VERSION 2.6)
project (Thoth)

add_definitions( -DBOOST_ALL_NO_LIB )
set(Boost_USE_STATIC_LIBS OFF )
set(Boost_USE_MULTITHREADED ON)
set(Boost_USE_STATIC_RUNTIME OFF)

configure_file (
  "${PROJECT_SOURCE_DIR}/main.h.in"
  "${PROJECT_BINARY_DIR}/main.h"
  )

set(BOOST_ROOT D:/Programs/boost_1_58_0)
set(BOOST_INCLUDEDIR ${BOOST_ROOT})
set(BOOST_LIBRARYDIR ${BOOST_ROOT}/stage/lib/)
find_package(Boost 1.58.0 COMPONENTS system filesystem REQUIRED)

include_directories("${PROJECT_BINARY_DIR}")

add_executable(Thoth main.cpp)

include_directories(${BOOST_INCLUDEDIR})
link_directories(${BOOST_LIBRARYDIR})

target_link_libraries( Thoth $(Boost_LIBRARIES))

C ++文件

#define BOOST_LIB_DIAGNOSTIC

#include <iostream>
#include <fstream>
#include <string>
#include <boost/filesystem.hpp>

#include "main.h"

using namespace std;

int main(int argc, char *argv[]){
    string line;
    ifstream input("../images/source/balls2.nff", ios::in);
    if (!input){
        cout << "Unable to open file";
        exit(1);
    }
    else{
        while (getline(input, line)){
            cout << line << '\n';
        }

        input.close();
    }

    return 0;
}

Visual Studio輸出

------ Build started: Project: ZERO_CHECK, Configuration: Debug x64 ------
------ Build started: Project: Thoth, Configuration: Debug x64 ------
main.obj : error LNK2019: unresolved external symbol "class boost::system::error_category const & __cdecl boost::system::system_category(void)" (?system_category@system@boost@@YAAEBVerror_category@12@XZ) referenced in function "void __cdecl boost::system::`dynamic initializer for 'native_ecat''(void)" (??__Enative_ecat@system@boost@@YAXXZ)
main.obj : error LNK2019: unresolved external symbol "class boost::system::error_category const & __cdecl boost::system::generic_category(void)" (?generic_category@system@boost@@YAAEBVerror_category@12@XZ) referenced in function "void __cdecl boost::system::`dynamic initializer for 'errno_ecat''(void)" (??__Eerrno_ecat@system@boost@@YAXXZ)
C:\Users\JR\Documents\Visual Studio 2013\Projects\thoth\_build64\Debug\Thoth.exe : fatal error LNK1120: 2 unresolved externals
------ Skipped Build: Project: ALL_BUILD, Configuration: Debug x64 ------
Project not selected to build for this solution configuration 
========== Build: 1 succeeded, 1 failed, 0 up-to-date, 1 skipped ==========

希望我忽略了一些愚蠢的事情，但是我一直在閱讀其他人的答案，並且一點也不了解。 我認為是時候尋求幫助了。

反饋后

我將保持最新的CMake並在此處調試輸出。 這樣其他用戶（或我）可以比較原始代碼和最終代碼。

CMake的

cmake_minimum_required (VERSION 2.6)
project (Thoth)

set(Boost_USE_STATIC_LIBS OFF )
set(Boost_USE_MULTITHREADED ON)
set(Boost_USE_STATIC_RUNTIME OFF)

configure_file (
  "${PROJECT_SOURCE_DIR}/main.h.in"
  "${PROJECT_BINARY_DIR}/main.h"
  )

set (Boost_DEBUG ON)
set(BOOST_ROOT D:/Programs/boost_1_58_0)
find_package(Boost 1.58.0 COMPONENTS system filesystem REQUIRED)
set(Boost_INCLUDE_DIRS ${BOOST_ROOT})
set(Boost_LIBRARY_DIRS ${BOOST_ROOT}/stage/lib/)
set(Boost_LIBRARIES ${BOOST_ROOT}/stage/lib/)
include_directories(${Boost_INCLUDE_DIRS})
link_directories(${Boost_LIBRARIES})

include_directories("${PROJECT_BINARY_DIR}")

add_executable(Thoth main.cpp)

if (WIN32)
    add_definitions( -DBOOST_ALL_NO_LIB )
    add_definitions( -DBOOST_ALL_DYN_LINK )
endif()

target_link_libraries( Thoth $(Boost_LIBRARIES))

調試打開時的CMake命令輸出（已刪除FindBoost的完整路徑以提高可讀性）

cmake .. -G"Visual Studio 12 Win64"
-- [ FindBoost.cmake:513 ] _boost_TEST_VERSIONS =
-- [ FindBoost.cmake:515 ] Boost_USE_MULTITHREADED = ON
-- [ FindBoost.cmake:517 ] Boost_USE_STATIC_LIBS = OFF
-- [ FindBoost.cmake:519 ] Boost_USE_STATIC_RUNTIME = OFF
-- [ FindBoost.cmake:521 ] Boost_ADDITIONAL_VERSIONS =
-- [ FindBoost.cmake:523 ] Boost_NO_SYSTEM_PATHS =
-- [ FindBoost.cmake:575 ] Declared as CMake or Environmental Variables:
-- [ FindBoost.cmake:577 ]   BOOST_ROOT = D:/Programs/boost_1_58_0
-- [ FindBoost.cmake:579 ]   BOOST_INCLUDEDIR =
-- [ FindBoost.cmake:581 ]   BOOST_LIBRARYDIR =
-- [ FindBoost.cmake:583 ] _boost_TEST_VERSIONS =
-- [ FindBoost.cmake:652 ] Include debugging info:
-- [ FindBoost.cmake:654 ]   _boost_INCLUDE_SEARCH_DIRS =
D:/Programs/boost_1_58_0/include;D:/Programs/boost_1_58_0;PATHS;C:/boost/include;C:/boost;/sw/local/include
-- [ C:/Program Files (x86)/CMake/share/cmake-3.0/Modules/FindBoost.cmake:656 ]   _boost_PATH_SUFFIXES =
-- [ FindBoost.cmake:676 ] location of version.hpp: D:/Programs/boost_1_58_0/boost/version.hpp
-- [ FindBoost.cmake:700 ] version.hpp reveals boost 1.58.0
-- [ FindBoost.cmake:785 ] guessed _boost_COMPILER = -vc120
-- [ FindBoost.cmake:795 ] _boost_MULTITHREADED = -mt
-- [ FindBoost.cmake:838 ] _boost_RELEASE_ABI_TAG = -
-- [ FindBoost.cmake:840 ] _boost_DEBUG_ABI_TAG = -gd
-- [ FindBoost.cmake:888 ] _boost_LIBRARY_SEARCH_DIRS = D:/Programs/boost_1_58_0/lib;D:/Programs/boost_1_58_0/stage/lib;D:/Programs/boost_1_58_0/lib;D:/Programs/boost_1_58_0/../lib;D:/Programs/boost_1_58_0/stage/lib;PATHS;C:/boost/lib;C:/boost;/sw/local/lib
-- [ FindBoost.cmake:998 ] Searching for SYSTEM_LIBRARY_RELEASE: boost_system-vc120-mt-1_58;boost_system-vc120-mt;boost_system-mt-1_58;boost_system-mt;boost_system
-- [ FindBoost.cmake:1034 ] Searching for SYSTEM_LIBRARY_DEBUG: boost_system-vc120-mt-gd-1_58;boost_system-vc120-mt-gd;boost_system-mt-gd-1_58;boost_system-mt-gd;boost_system-mt;boost_system
-- [ FindBoost.cmake:998 ] Searching for FILESYSTEM_LIBRARY_RELEASE: boost_filesystem-vc120-mt-1_58;boost_filesystem-vc120-mt;boost_filesystem-mt-1_58;boost_filesystem-mt;boost_filesystem
-- [ FindBoost.cmake:1034 ] Searching for FILESYSTEM_LIBRARY_DEBUG: boost_filesystem-vc120-mt-gd-1_58;boost_filesystem-vc120-mt-gd;boost_filesystem-mt-gd-1_58;boost_filesystem-mt-gd;boost_filesystem-mt;boost_filesystem
-- [ FindBoost.cmake:1085 ] Boost_FOUND = 1
-- Boost version: 1.58.0
-- Found the following Boost libraries:
  --   system
  --   filesystem
-- Configuring done
-- Generating done
-- Build files have been written to: C:/Users/JR/Documents/Visual Studio 2013/Projects/thoth/_build64

Answer 1

這里有兩個相當瑣碎的問題，希望應該很容易解決。

首先是find_package(Boost ...)可能正在正確地執行其工作，即它正在為Boost_INCLUDE_DIRS ， Boost_LIBRARY_DIRS和Boost_LIBRARIES設置良好的值。 但是，您可以通過調用三個set命令立即覆蓋這些變量！ 因此，您應該刪除這三個命令。

另一個問題在您的target_link_libraries調用中-在嘗試取消引用Boost_LIBRARIES時，您不小心使用了括號而不是大括號- $(Boost_LIBRARIES)更改為${Boost_LIBRARIES} 。

順便說一下，還有其他一些與該問題無關的要點：

1. 通常，您不應該在CMakeLists.txt中設置BOOST_ROOT 。 真正的目的是通過在命令行上（或通過CMake GUI）將其作為-D arg傳遞來進行設置，從而不會將其硬編碼為特定於您自己的計算機的值。

2. 您不需要link_directories調用。 它自己的文檔不鼓勵其使用：

   請注意，此命令很少需要。 find_package()和find_library()返回的庫位置是絕對路徑。 將這些絕對庫文件路徑直接傳遞給target_link_libraries()命令。 CMake將確保鏈接器找到它們。