如何讓VS2008在C++項目中使用__cdecl而不是__thiscall？

Question

我想在Visual Studio 2008中構建一個開源C++項目。我加載解決方案文件並編譯所有內容，但由於未找到某些方法，我收到了一堆鏈接錯誤。使用DUMPBIN.EXE檢查有問題的.lib文件後，我可以看到問題所在：.lib中的方法在它們的簽名中都有__cdecl，而鏈接器正在尋找與__thiscall相同的方法。

如何讓VS 2008使用__cdecl代替？

注意：該項目是a fork of CCV，基於OpenCV的多點觸控跟蹤程序。此叉的目的是通過相機制造商提供的FlyCapture2庫爲稱爲Flea3的相機提供支持。這裏是鏈接錯誤：

1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall FlyCapture2::Image::Image(void)" (__imp_??0Image@FlyCapture2@@QAE@XZ) referenced in function "public: __thiscall ofxFlea3::ofxFlea3(void)" (??0ofxFlea3@@QAE@XZ) 
1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual __thiscall FlyCapture2::Image::~Image(void)" (__imp_??1Image@FlyCapture2@@UAE@XZ) referenced in function "public: __thiscall ofxFlea3::ofxFlea3(void)" (??0ofxFlea3@@QAE@XZ) 
1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall FlyCapture2::Camera::Camera(void)" (__imp_??0Camera@FlyCapture2@@QAE@XZ) referenced in function "public: __thiscall ofxFlea3::ofxFlea3(void)" (??0ofxFlea3@@QAE@XZ) 
1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual __thiscall FlyCapture2::Camera::~Camera(void)" (__imp_??1Camera@FlyCapture2@@UAE@XZ) referenced in function "public: __thiscall ofxFlea3::ofxFlea3(void)" (??0ofxFlea3@@QAE@XZ) 
1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual __thiscall FlyCapture2::Error::~Error(void)" (__imp_??1Error@FlyCapture2@@UAE@XZ) referenced in function "void __cdecl PrintError(class FlyCapture2::Error)" (?PrintError@@YAXVError@FlyCapture2@@@Z) 
1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual void __thiscall FlyCapture2::Error::PrintErrorTrace(void)const " (__imp_?PrintErrorTrace@Error@FlyCapture2@@UBEXXZ) referenced in function "void __cdecl PrintError(class FlyCapture2::Error)" (?PrintError@@YAXVError@FlyCapture2@@@Z) 
1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual class FlyCapture2::Error __thiscall FlyCapture2::BusManager::GetCameraFromIndex(unsigned int,class FlyCapture2::PGRGuid *)" (__imp_?GetCameraFromIndex@BusManager@FlyCapture2@@UAE?AVError@2@IPAVPGRGuid@2@@Z) referenced in function "public: void __thiscall ofxFlea3::listDevices(void)" (?listDevices@ofxFlea3@@QAEXXZ) 
1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual __thiscall FlyCapture2::BusManager::~BusManager(void)" (__imp_??1BusManager@FlyCapture2@@UAE@XZ) referenced in function "public: void __thiscall ofxFlea3::listDevices(void)" (?listDevices@ofxFlea3@@QAEXXZ) 
1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall FlyCapture2::Error::Error(class FlyCapture2::Error const &)" (__imp_??0Error@FlyCapture2@@QAE@ABV01@@Z) referenced in function "public: void __thiscall ofxFlea3::listDevices(void)" (?listDevices@ofxFlea3@@QAEXXZ) 
1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual class FlyCapture2::Error __thiscall FlyCapture2::BusManager::GetNumOfCameras(unsigned int *)" (__imp_?GetNumOfCameras@BusManager@FlyCapture2@@UAE?AVError@2@PAI@Z) referenced in function "public: void __thiscall ofxFlea3::listDevices(void)" (?listDevices@ofxFlea3@@QAEXXZ) 
1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall FlyCapture2::Error::Error(void)" (__imp_??0Error@FlyCapture2@@QAE@XZ) referenced in function "public: void __thiscall ofxFlea3::listDevices(void)" (?listDevices@ofxFlea3@@QAEXXZ) 
1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall FlyCapture2::BusManager::BusManager(void)" (__imp_??0BusManager@FlyCapture2@@QAE@XZ) referenced in function "public: void __thiscall ofxFlea3::listDevices(void)" (?listDevices@ofxFlea3@@QAEXXZ) 
1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual class FlyCapture2::Error __thiscall FlyCapture2::Image::Save(char const *,enum FlyCapture2::ImageFileFormat)" (__imp_?Save@Image@FlyCapture2@@UAE?AVError@2@PBDW4ImageFileFormat@2@@Z) referenced in function "public: void __thiscall ofxFlea3::initFlea3(int,int,int,int)" (?initFlea3@ofxFlea3@@QAEXHHHH@Z) 
1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual class FlyCapture2::Error __thiscall FlyCapture2::Image::Convert(enum FlyCapture2::PixelFormat,class FlyCapture2::Image *)const " (__imp_?Convert@Image@FlyCapture2@@UBE?AVError@2@W4PixelFormat@2@PAV12@@Z) referenced in function "public: void __thiscall ofxFlea3::initFlea3(int,int,int,int)" (?initFlea3@ofxFlea3@@QAEXHHHH@Z) 
1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual class FlyCapture2::Error __thiscall FlyCapture2::Image::ReleaseBuffer(void)" (__imp_?ReleaseBuffer@Image@FlyCapture2@@UAE?AVError@2@XZ) referenced in function "protected: virtual void __thiscall ofxFlea3::getNewFrame(unsigned char *)" (?getNewFrame@ofxFlea3@@MAEXPAE@Z) 
1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual struct FlyCapture2::TimeStamp __thiscall FlyCapture2::Image::GetTimeStamp(void)const " (__imp_?GetTimeStamp@Image@FlyCapture2@@UBE?AUTimeStamp@2@XZ) referenced in function "protected: virtual void __thiscall ofxFlea3::getNewFrame(unsigned char *)" (?getNewFrame@ofxFlea3@@MAEXPAE@Z) 
1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual unsigned char * __thiscall FlyCapture2::Image::GetData(void)" (__imp_?GetData@Image@FlyCapture2@@UAEPAEXZ) referenced in function "protected: virtual void __thiscall ofxFlea3::getNewFrame(unsigned char *)" (?getNewFrame@ofxFlea3@@MAEXPAE@Z) 
1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual unsigned int __thiscall FlyCapture2::Image::GetDataSize(void)const " (__imp_?GetDataSize@Image@FlyCapture2@@UBEIXZ) referenced in function "protected: virtual void __thiscall ofxFlea3::getNewFrame(unsigned char *)" (?getNewFrame@ofxFlea3@@MAEXPAE@Z) 
1>ofxFlea3.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual void __thiscall FlyCapture2::Image::GetDimensions(unsigned int *,unsigned int *,unsigned int *,enum FlyCapture2::PixelFormat *,enum FlyCapture2::BayerTileFormat *)const " (__imp_?GetDimensions@Image@FlyCapture2@@UBEXPAI00PAW4PixelFormat@2@PAW4BayerTileFormat@2@@Z) referenced in function "protected: virtual void __thiscall ofxFlea3::getNewFrame(unsigned char *)" (?getNewFrame@ofxFlea3@@MAEXPAE@Z) 

Answer 1

默認情況下，Visual Studio將使用__thiscall成員函數。由於它編譯正確，看起來庫中的頭文件並沒有顯式聲明調用約定。

這聽起來像你需要使用C鏈接庫。嘗試用庫包頭標頭

extern "C" { } 

Answer 2

問題是我連接到64位版本的外部FlyCapture2庫。切換到32位版本解決了這個問題。