How to include a library in a Qt project

Question

I'm trying to create a project that uses the TagLib library. I'm not really sure of how exactly to go about it.

I have downloaded TagLib 1.11.1 .

I built it as follows:

Build zlib, by first having CMake create a Visual Studio solution file, then building this solution with Visual Studio:

mkdir build && cd build cmake .. -G"Visual Studio 14 2015 Win64" -DCMAKE_INSTALL_PREFIX="e:\\workspace\\lib\\installed" msbuild /P:Configuration=Debug INSTALL.vcxproj msbuild /P:Configuration=Release INSTALL.vcxproj

Build TagLib much in the same way:

cd ....\\taglib-1.11.1 mkdir build && cd build cmake .. -G"Visual Studio 14 2015 Win64" -DCMAKE_INSTALL_PREFIX="e:\\workspace\\lib\\installed" -DZLIB_INCLUDE_DIR="e:\\workspace\\lib\\installed\\include" -DZLIB_LIBRARY="e:\\workspace\\lib\\installed\\lib\\zlib.lib" -DWITH_ASF=on -DWITH_MP4=on -DBUILD_EXAMPLES=on msbuild /P:Configuration=Release INSTALL.vcxproj

I create a simple Qt Console Application:

I then add tag.lib from the TagLib Build above in E:\\workspace\\lib\\installed\\lib using Qt

Qt -> Add Library -> Library Type (External Library) -> .......

main.cpp :

#include <QCoreApplication>
#include <QDebug>

#include <taglib/fileref.h>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    TagLib::FileRef f("D:/Dire Straits - Sultans of Swing.mp3");
    return a.exec();
}

taglibtest.pro

QT += core
QT -= gui

CONFIG += c++11

TARGET = taglibtest
CONFIG += console
CONFIG -= app_bundle

TEMPLATE = app

SOURCES += main.cpp

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/taglib/builds/ -ltag
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/taglib/builds/ -ltagd
else:unix: LIBS += -L$$PWD/taglib/builds/ -ltag

INCLUDEPATH += $$PWD/taglib/builds
DEPENDPATH += $$PWD/taglib/builds

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/taglib/builds/ -ltag
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/taglib/builds/ -ltagd
else:unix: LIBS += -L$$PWD/taglib/builds/ -ltag

INCLUDEPATH += $$PWD/taglib/builds
DEPENDPATH += $$PWD/taglib/builds

HEADERS += \
    taglib/aifffile.h \
    taglib/aiffproperties.h \
    taglib/apefile.h \
    taglib/apefooter.h \
    taglib/apeitem.h \
    taglib/apeproperties.h \
    taglib/apetag.h \
    taglib/asfattribute.h \
    taglib/asffile.h \
    taglib/asfpicture.h \
    taglib/asfproperties.h \
    etc....
    etc....

I get the following errors whenever I try Building the project in Qt:

F:\taglibtest\main.cpp:-1: error: undefined reference to `_imp___ZN6TagLib8FileNameC1EPKc'  

F:\taglibtest\main.cpp:-1: error: undefined reference to `_imp___ZN6TagLib7FileRefC1ENS_8FileNameEbNS_15AudioProperties9ReadStyleE'  

F:\taglibtest\main.cpp:-1: error: undefined reference to `_imp___ZN6TagLib7FileRefD1Ev'  

F:\taglibtest\main.cpp:-1: error: undefined reference to `_imp___ZN6TagLib7FileRefD1Ev'  

:-1: error: release/main.o: bad reloc address 0x0 in section `.ctors'  

:-1: error: final link failed: Invalid operation  

collect2.exe:-1: error: error: ld returned 1 exit status  

What should I do to fix this and get working with TagLib?

taglibtest.pro

QT += core
QT -= gui

CONFIG += c++11

TARGET = taglibtest
CONFIG += console
CONFIG -= app_bundle

TEMPLATE = app

SOURCES += main.cpp

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/taglib/builds/ -ltag
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/taglib/builds/ -ltagd
else:unix: LIBS += -L$$PWD/taglib/builds/ -ltag

INCLUDEPATH += $$PWD/taglib/builds
DEPENDPATH += $$PWD/taglib/builds

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/taglib/builds/ -ltag
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/taglib/builds/ -ltagd
else:unix: LIBS += -L$$PWD/taglib/builds/ -ltag

INCLUDEPATH += $$PWD/taglib/builds
DEPENDPATH += $$PWD/taglib/builds

HEADERS += \
    taglib/aifffile.h \
    taglib/aiffproperties.h \
    taglib/apefile.h \
    taglib/apefooter.h \
    taglib/apeitem.h \
    taglib/apeproperties.h \
    taglib/apetag.h \
    taglib/asfattribute.h \
    taglib/asffile.h \
    taglib/asfpicture.h \
    taglib/asfproperties.h \
    etc....
    etc....

Answer 1

You have compiled TagLib and zlib with Visual Studio and you compile your project with mingw (at least that's what I can guess from error messages). This won't work. You need to compile all your libraries and apps with the very same compiler.

Visual Studio and gcc have different ABI 's so gcc cannot see Visual 's symbols.