c++ - 引用另一个库的c++静态库的链接器错误

Question

我是C++的新手，调试链接器错误时遇到问题。我在g++编译器中使用wxDev-c++。我创建了一个静态库，该库链接到一个基本项目。该库最初不包含对外部头文件或库的引用，它只是几个简单的测试函数，将两个double值加在一起并返回值。链接到测试项目时，此方法工作正常。但是，我现在正在尝试将FTP合并到该库中，并且出现链接器错误。

目前，测试功能只是试图访问相同的简单加法功能以进行测试，我什至没有调用FTP功能，因为我只是想使测试项目正确编译。

库代码:

DaFTPLib.h:

#ifndef WAVE_H
#define WAVE_H
#ifdef __BORLANDC__
#pragma hdrstop
#endif

#ifndef WX_PRECOMP
#include <wx/wx.h>
#else
#include <wx/wxprec.h>
#endif

#include <wx/protocol/ftp.h>

namespace Wave
{
    class DaFTP
    {
        public:
        DaFTP(char *url, char *login, char *password);
        ~DaFTP();
        const int Download(char* fileName);
        static const void DownloadNCWD(char *url, char *fileName, char *login, char *password);
        static const void DownloadLAMP();
        static double FuncA(double a, double b);
        static double FuncB(double a, double b);

        private:
        char* url, login, password;
        wxFTP ftp;
    };
}

#endif

DaFTP.cpp:

#include "DaFTPLib.h"

using namespace std;
char* _url;
char* _login;
char* _password;
wxFTP ftp;

namespace Wave
{
    DaFTP::DaFTP(char *url, char *login, char *password)
    {
       _url = url;
       _login = login;
       _password = password;
    }

    DaFTP::~DaFTP(){}

    const int DaFTP::Download(char *fileName)
    {
        int fileSize;

        ftp.SetPassive(true);
        ftp.SetUser(_login);
        ftp.SetPassword(_password);
        ftp.Connect(_url);

        fileSize = ftp.GetFileSize(fileName);
        return fileSize;
    }

    const void DaFTP::DownloadNCWD(char *url, char *fileName, char *login, char *password)
    {
        DaFTP daftp(url, login, password);
        daftp.Download(fileName);
    }

    const void DaFTP::DownloadLAMP() {}

    double DaFTP::FuncA(double a, double b)
    {
         return a + b;
    }
    double DaFTP::FuncB(double a, double b)
    {
         return a - b;
    }
}

测试项目代码:

#include <cstdlib>
#include <iostream>

#include "../libDaFTP/DaFTPLib.h"

using namespace std;

int main(int argc, char *argv[])
{
    double a, b, c;

    a = 23.32;
    b = 26.68;

    c = Wave::DaFTP::FuncA(a, b);
    cout << "FuncA val: " << c << endl;

    c = Wave::DaFTP::FuncB(a, b);
    cout << "FuncB val: " << c << endl;
    system("PAUSE");
    return EXIT_SUCCESS;
}

库的编译日志输出(编译正常):

执行make ...
mingw32-make.exe -f“Makefile.win”全部
g++。exe -c DaFTPLib.cpp -o对象/MingW/DaFTPLib.o -I“C:/程序文件(x86)/Dev-Cpp/lib/gcc/mingw32/3.4.5/include” -I“C:/Program Files(x86)/Dev-Cpp/include/c++/3.4.5/backward“-I” C:/Program Files(x86)/Dev-Cpp/include/c++/3.4.5/mingw32“-I” C:/程序文件(x86)/Dev-Cpp/include/c++/3.4.5“-I” C:/程序文件(x86)/Dev-Cpp/include“-I” C:/程序文件(x86)/Dev-Cpp/“-I” C:/程序文件(x86)/Dev-Cpp/include/common/wx/msw“-I” C:/程序文件(x86)/Dev-Cpp/include/common/wx/generic“-I” C:/程序文件(x86)/Dev-Cpp/include/common/wx/html“-I” C:/Program文件(x86)/Dev-Cpp/include/common/wx/协议(protocol)“-I” C:/程序文件(x86)/Dev-Cpp/include/common/wx/xml“-I” C:/程序文件(x86)/Dev-Cpp/include/common/wx/xrc“-I“C:/程序文件(x86)/Dev-Cpp/include/common/wx” -I“C:/程序文件(x86)/Dev-Cpp/include/common”

ar rcu“输出/MingW/libDaFTP.a”“对象/MingW/DaFTPLib.o”

执行终止
编译成功
编译耗时1秒完成

测试项目的编译日志输出(编译失败)

执行make ...
mingw32-make.exe -f“Makefile.win”全部
g++。exe -c main.cpp -o对象/MingW/main.o -I“C:/程序文件(x86)/Dev-Cpp/lib/gcc/mingw32/3.4.5/include” -I“C:/Program Files(x86)/Dev-Cpp/include/c++/3.4.5/backward“-I” C:/Program Files(x86)/Dev-Cpp/include/c++/3.4.5/mingw32“-I” C:/程序文件(x86)/Dev-Cpp/include/c++/3.4.5“-I” C:/程序文件(x86)/Dev-Cpp/include“-I” C:/程序文件(x86)/Dev-Cpp/“-I” C:/程序文件(x86)/Dev-Cpp/include/common/wx/msw“-I” C:/程序文件(x86)/Dev-Cpp/include/common/wx/generic“-I” C:/程序文件(x86)/Dev-Cpp/include/common/wx/html“-I” C:/Program文件(x86)/Dev-Cpp/include/common/wx/协议(protocol)“-I” C:/程序文件(x86)/Dev-Cpp/include/common/wx/xml“-I” C:/程序文件(x86)/Dev-Cpp/include/common/wx/xrc“-I“C:/程序文件(x86)/Dev-Cpp/include/common/wx” -I“C:/程序文件(x86)/Dev-Cpp/include/common”

g++。exe“Objects/MingW/main.o” -o“Output/MingW/LibTest.exe” -L“C:/Program Files(x86)/Dev-Cpp/Lib” ../libDaFTP/Output/MingW/libDaFTP.a

对象/MingW/main.o:main.cpp:(.rdata$_ZTV20wxThreadHelperThread[wxThreadHelperThread的vtable] + 0xc):对 wxThread::TestDestroy()'
Objects/MingW/main.o:main.cpp:(.text$_ZN20wxThreadHelperThreadD1Ev[wxThreadHelperThread::~wxThreadHelperThread()]+0x16): undefined reference to的 undefined reference wxThread::〜wxThread()'
对象/MingW/main.o:main.cpp:(.text$_ZN20wxThreadHelperThreadD0Ev[wxThreadHelperThread::~wxThreadHelperThread()]+0x16):对 wxThread::~wxThread()'
../libDaFTP/Output/MingW/libDaFTP.a(DaFTPLib.o):DaFTPLib.cpp:(.text+0x10): undefined reference to的 undefined reference wxFTP::wxFTP()'
../libDaFTP/Output/MingW/libDaFTP.a(DaFTPLib.o):DaFTPLib.cpp:(.text+0x3e):对 wxFTP::wxFTP()'
../libDaFTP/Output/MingW/libDaFTP.a(DaFTPLib.o):DaFTPLib.cpp:(.text+0x6c): undefined reference to wxFTP::〜wxFTP()的 undefined reference
../libDaFTP/Output/MingW/libDaFTP.a(DaFTPLib.o):DaFTPLib.cpp:(.text+0x82):未定义对 wxFTP::~wxFTP()'
../libDaFTP/Output/MingW/libDaFTP.a(DaFTPLib.o):DaFTPLib.cpp:(.text+0x1e3): undefined reference to的引用wxFTP::Connect(wxString const＆)'
../libDaFTP/Output/MingW/libDaFTP.a(DaFTPLib.o):DaFTPLib.cpp:(.text+0x24e):对 wxFTP::GetFileSize(wxString const&)'
../libDaFTP/Output/MingW/libDaFTP.a(DaFTPLib.o):DaFTPLib.cpp:(.text+0x43f): undefined reference to wxFTP::wxFTP()的 undefined reference
../libDaFTP/Output/MingW/libDaFTP.a(DaFTPLib.o):DaFTPLib.cpp:(.text+0x45a):未定义对 wxFTP::~wxFTP()'
../libDaFTP/Output/MingW/libDaFTP.a(DaFTPLib.o):DaFTPLib.cpp:(.text$_ZN8wxStringaSERKS_[wxString::operator=(wxString const&)]+0x14): undefined reference to的引用wxStringBase::operator =(wxStringBase const＆)'
../libDaFTP/Output/MingW/libDaFTP.a(DaFTPLib.o):DaFTPLib.cpp:(.text$_ZN12wxStringBaseC2EPKc[wxStringBase::wxStringBase(char const *)] + 0x7):对 wxStringBase::npos'
../libDaFTP/Output/MingW/libDaFTP.a(DaFTPLib.o):DaFTPLib.cpp:(.text$_ZN12wxStringBaseC2EPKc[wxStringBase::wxStringBase(char const*)]+0x25): undefined reference to wxStringBase::InitWith的 undefined reference (字符const *，unsigned int，unsigned int)'
collect2:ld返回1退出状态

mingw32-make.exe:* [Output/MingW/LibTest.exe]错误1

执行终止
编译失败。退货2

对于冗长的帖子，我深表歉意，但希望这对于有人向我指出正确的方向提供了足够的信息。我以为问题在于合并wx/protocol/ftp库，但是我的假设是，在编译我的库时，任何支持的库(例如ftp东西)都将与之一起编译。

Answer 1

but I was under the assumption that when compiling my library any supporting libraries such as the ftp stuff would be compiled in with it.

您所说的仅适用于动态链接的库:如果您构建引用其他库的静态库，则链接到您的静态库的应用程序或DLL仍必须链接到其他库。静态库只不过是编译的目标代码的集合。库代码中引用的外部函数尚未链接。

使您的帮助程序库成为DLL并将其链接到wx库，或者使其保持静态并将使用该静态库的每个应用程序链接到wx库。