Compiling C++ code with Qt components

Question

I'm trying to build a GUI for a set of C++ files that I've been writing, and I decided to try Qt. However, trying to compile the files that I have added Qt components to has proven to be difficult. I'm using clang, with the invocation

clang++ -std=c++0x -stdlib=libc++ -framework QtGui F/Users/[uname]/Qt5.1.0/5.1.0/clang_64/lib -I/Users/[uname]/Qt5.1.0/5.1.0/clang_64/include -L/Users/[uname]/Qt5.1.0/5.1.0/clang_64/lib  -o QT qt.cpp

And this works if I include just

#include "QtGui/QGuiApplication"

It seems like I should be should be using, though,

#include <QtGui/QApplication>

which fails with the error

fatal error: 'QtGui/QApplication' file not found

If I try to include the qpushbutton.h file, with

#include "QtWidgets/QPushButton"

I get an error:

clang++ -std=c++0x -stdlib=libc++ -framework QtGui -F/Users/[uname]/Qt5.1.0/5.1.0/clang_64/lib -I/Users/[uname]/Qt5.1.0/5.1.0/clang_64/include -L/Users/[uname]/Qt5.1.0/5.1.0/clang_64/lib -v  -o QT qt.cpp
Apple LLVM version 4.2 (clang-425.0.28) (based on LLVM 3.2svn)
Target: x86_64-apple-darwin11.4.2
Thread model: posix
"/usr/bin/clang" -cc1 -triple x86_64-apple-macosx10.7.0 -emit-obj -mrelax-all -disable-free -disable-llvm-verifier -main-file-name qt.cpp -pic-level 2 -mdisable-fp-elim -masm-verbose -munwind-tables -target-cpu core2 -target-linker-version 136 -v -resource-dir /usr/bin/../lib/clang/4.2 -F/Users/[uname]/Qt5.1.0/5.1.0/clang_64/lib -I /Users/[uname]/Qt5.1.0/5.1.0/clang_64/include -fmodule-cache-path /var/folders/lw/wq_l1f1936q0dmc1b_tkp94m0000gn/T/clang-module-cache -stdlib=libc++ -std=c++0x -fdeprecated-macro -fdebug-compilation-dir "[path]" -ferror-limit 19 -fmessage-length 204 -stack-protector 1 -mstackrealign -fblocks -fobjc-runtime=macosx-10.7.0 -fobjc-dispatch-method=mixed -fobjc-default-synthesize-properties -fcxx-exceptions -fexceptions -fdiagnostics-show-option -fcolor-diagnostics -o /var/folders/lw/wq_l1f1936q0dmc1b_tkp94m0000gn/T/qt-YxX3PY.o -x c++ qt.cpp
clang -cc1 version 4.2 based upon LLVM 3.2svn default target x86_64-apple-darwin11.4.2
ignoring nonexistent directory "/usr/include/c++/v1"
#include "..." search starts here:
#include <...> search starts here:
 /Users/[uname]/Qt5.1.0/5.1.0/clang_64/lib (framework directory)
 /Users/[uname]/Qt5.1.0/5.1.0/clang_64/include
 /usr/bin/../lib/c++/v1
 /usr/local/include
 /usr/bin/../lib/clang/4.2/include
 /usr/include
 /System/Library/Frameworks (framework directory)
 /Library/Frameworks (framework directory)
End of search list.
 "/usr/bin/ld" -demangle -dynamic -arch x86_64 -macosx_version_min 10.7.0 -o QT -lcrt1.10.6.o -L/Users/[uname]/Qt5.1.0/5.1.0/clang_64/lib -framework QtGui /var/folders/lw/wq_l1f1936q0dmc1b_tkp94m0000gn/T/qt-YxX3PY.o -lc++ -lSystem /usr/bin/../lib/clang/4.2/lib/darwin/libclang_rt.osx.a -F/Users/[uname]/Qt5.1.0/5.1.0/clang_64/lib
Undefined symbols for architecture x86_64:
  "QArrayData::deallocate(QArrayData*, unsigned long, unsigned long)", referenced from:
  QTypedArrayData<unsigned short>::deallocate(QArrayData*) in qt-YxX3PY.o
  "QPushButton::QPushButton(QString const&, QWidget*)", referenced from:
  _main in qt-YxX3PY.o
  "QPushButton::~QPushButton()", referenced from:
  _main in qt-YxX3PY.o
  "QString::fromAscii_helper(char const*, int)", referenced from:
  QString::QString(char const*) in qt-YxX3PY.o
  "QWidget::show()", referenced from:
  _main in qt-YxX3PY.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

I also have been trying qmake, which fails from the same missing symbols from the x86_64 architecture as above, with the qt.pro file being

QT += core
QT += gui
SOURCE += qt.cpp

The qt.cpp file itself is just a sample:

#include <QtGui/QApplication>
#include <QtGui/QPushButton>

int main(int argc, char* argv[]){

    QApplication app(argc, argv);

    QPushButton but ("Button");
    but.show();

    return app.exec();
}

The files I'm working with need to be compiled in the C++11 standard and I really don't want to switch IDEs, so Qt Creator is not an ideal solution (Qt Creator also generates the missing symbols error).

I'm sure there's something obvious I'm missing, but I need to continue work on the non-GUI aspects of the project ASAP.

I'm running Mac OS 10.7.5 on a MacBook Air 64bit. I installed Qt5.1.0 from the Mac Installer offered on the Qt site. My clang++ version is 4.2 (clang-425.0.28), installed via command line tools in XCode.

Thanks in advance.

Answer 1

You seem to be trying to build with Qt 5 where the Widgets were moved to QtWidgets.

That is why you need to change the includes from QtGui to QtWidgets.

On top of that, you need add "widgets" to Qt. Also, core and gui are present by default, so you should write: QT += widgets in this particular scenario.

Not sure if this fixes your architecture related issue, but those things are at least wrong.