How to install Qt on Windows after building?

I can't find any information on how to install Qt built on Windows.
In wiki article How to set up shadow builds on Mac and Linux there's description of -prefix option in configure script but this option is not available on Windows.
I know I can use Qt right from the build folder but it does not seem the right thing not to perform an install step. One problem with this approach is size; Qt's build folder takes about 4GB space whereas after installing using binary installer Qt takes about 1GB space. I guess the difference is due to temporary files created during building. I hope some install procedure would install (copy) only needed files leaving temporary files in the build folder.

Solution 1:

As İsmail said there's no install step for Qt on Windows. However one can try to approximate it by performing the following operations.

1. Cleaning
   Run make clean in the build folder to remove all temporary files.
2. Moving
   Copy build folder to the place where you want Qt "installed". Let's call it INSTALL_DIR.
3. Fixing paths hardcoded in the qmake.exe executable
   Run qmake -query to see what paths are compiled (hardcoded) into qmake and
   a. Fix paths containing the build folder by replacing it with the INSTALL_DIR using qmake -set (1).
   or
   b. Create a qt.conf file in the bin subfolder of the INSTALL_DIR specifing new Qt paths inside it.
4. Adding current directory to include path
   In Qt's provided binary distributions, the pwd is included in the QMAKE_INCDIR and thus ends up in your projects include path as ".". This does not happen by default in a custom built Qt, so you have to add the following line to mkspecs/YOUR-PLATFORM-HERE/qmake.conf file:
   QMAKE_INCDIR += "."
5. Fixing prl files
   When you add a Qt component to a project file (such as CONFIG += uitools), Qt looks in %QTDIR%/lib/QtUiTools.prl to find the library dependencies of that component. These files will have the hard coded path of the directory in which Qt was configured and built. You have to replace that build directory with the one to which you moved Qt for all lib/*.prl files.
6. Making source available
   If you made a shadow build (build made inside folder other than the one containg sources), headers in the include subfolder only forward to the original headers. For example; BUILD_DIR\include\QtCore\qabstractanimation.h looks like this
   #include "SRC_DIR/src/corelib/animation/qabstractanimation.h"
   If you don't want to depend on the existence of the folder containg sources you have to copy SRC_DIR/src subfolder to your destination folder and fix all headers in the include folder so that they forward to the new location of src subfolder.

The bottom line:
The build process of Qt under Windows makes it really akward to move (install) Qt after building. You should do this only if ... well I can't find any good reason to go through all this trouble.

Remember
The easy way is to place Qt's sources in the folder where you want Qt to stay after building and make a build in this folder. This makes all steps but 1 and 4 above unnecessary.

1)
The variables you set with qmake -set are saved in the registry key
HKEY_CURRENT_USER\Software\Trolltech\QMake\<QMAKE_VERSION>.
Because of this you might have a problem when you would like to have different projects using different versions of Qt which happen to have the same version of qmake. In this case the better solution is to use qt.conf file (actually files as you need one file for each Qt installation) (option 3b).

Many of the information above come from the RelocationTricks wiki page authored by Gabe Rudy. Check out his Qt (Qt4) Opensource Windows Installers of Pre-built Binaries with MSVC 2008 project which gives you easy solution of above problems.

Solution 2:

This answer is a replacement for steps 3 and 5 of Piotr's (currently top rated) answer above, but you may still need the other steps in his answer, depending what you're trying to achieve.

• This is the operation which the official installer uses to fix the hardcoded paths during the installation: qt.520.win32_msvc2012.addons/meta/installscript.qs
• This is how the operation is implemented: qtpatchoperation.cpp
• This is the list of files that it fixes: files-to-patch-windows-qt5
• And this shows how to invoke an installer operation as a standalone command from the commandline: Operations (Qt Installer Framework Manual)

To summarize: after moving your Qt directory to where you want it, download any one of the official Qt installers and run it with the following commandline arguments:

cd <path>
installer.exe --runoperation QtPatch windows <path> qt5

Replace <path> with the full path of your Qt directory after you moved it (the qtbase directory if you are using Qt 5). Omit the final qt5 argument if you are using Qt 4.

This will fix the hardcoded paths in qmake.exe, .prl files, and others. It gives you the exact same behaviour that the official installers have in that respect.

For the initial move, nmake "INSTALL_ROOT=\somewhere" install works for me. So that's steps 1 and 2 of Piotr's answer covered. And I haven't needed steps 4 or 6, FWIW.

Solution 3:

I can configure QT 5 on WINDOWS (Visual Studio build) with the prefix option like:

configure -prefix C:\the\path\I\want ...

then call:

nmake
nmake install

and the latter will install Qt in C:\the\path\I\want.

I did it without problems with Qt 5.2.1 and 5.3.x, so far. So, any earlier problems seem to be fixed by now.

Solution 4:

It's very odd people claim that there is no "make install" on Windows.

I have used it many times, and I agree that it's not what it is on other platforms, but it serves its purpose.

How I use Qt's make install on Windows (from cmd):

configure
(n/mingw32-)make
(n/mingw32-)make docs
(n/mingw32-)make install

The make install bit copies all necessary headers to be able to delete your source directory. Delete all objects and unecessary stuff:

del /S /Q *.obj lib\*.dll
rmdir /S /Q docs-build qmake tools src

This allows you to remove the source directory. I don't know what impact this has on debugging Qt source code, but it sure reduces the size of a shadow build. I use it to maintain 32 and 64 bit builds with minimal size.

Solution 5:

Qt on Windows is not installable with make install, you will notice that Qt installer for Windows just patches dlls & pdbs for the new install location.

What I would suggest is to do a shadow build in the place you would like to install it. You can manually remove *.obj files to save up space.