Редактирование: Part 3

<h1>Cross compiling Qt/Win Apps on Linux</h1>

<p>
Important note: this how-to is written for Qt 4.x - it should work for both the commercial and the free versions (I tested it with commercial).
</p>

<p>
In order to run these tests you'll need a cross compiler. How to create one is described in [[Part 1]] of this series.
</p>

<p>
If you want to use this for a commercial (non-GPL) project, you have to make sure you own the right licenses. According to Trolltech's support you need one for each developer on the platforms he/she actually develops on and at least one for each target platform - so that you can link against the correct runtime libs. Eg. if you have three developers, two working on Linux and one on Windows and your target platforms are Linux, Windows, and MacOS/X then you will need four licenses: one for each developer (twice X11, once Win32) and an extra one for the additional target platform MacOS/X.
</p>

<h2>Preparing Qt</h2>

<p>
You have two options of building Qt:
</p>

<ul>
<li>pre-compile Qt on Windows, this is much more stress free, since Qt builds some tools it needs for building first. Use the same MinGW version for building that you use on Linux!</li>
<li>go the adventurous road and cross-compiler Qt, see [[Part 2]] of this series.</li>
</ul>

<p>
Then build the same version of Qt for Linux - you will need the tools (qmake,
uic, moc, etc.).
</p>

<p>
You will need the include and library files of Qt for compiling and linking, so
if you built Qt on Windows: either mount the Windows disk on Linux or copy the full tree over to your Linux disk. It is not recommended to mix the directories.
</p>

<p>
On your Linux copy of Qt go into the mkspecs directory and copy the win32-g++ spec to win32-x-g++ and correct the qmake.conf file - you'll find an example for 4.0.1 in <a href="http://silmor.de/29/image/win32-x-g++-qmake.conf">win32-x-g++-qmake.conf</a>.
</p>

<p>
The important part is to replace all references to gcc/g++ with references to the cross compiler and to replace the cmd.exe shell utilities with their Linux counterparts.
</p>

<p>
Also make sure &quot;-mwindows&quot; is in the spec otherwise you
will be bothered with a console window snapping open everytime a Qt-App starts
(replace that with &quot;-mconsole&quot; if you actually plan to create console apps).
</p>

<p>
These are the important lines for an installation that has MinGW in /usr/local/mingw and Qt/Win in /usr/local/Trolltech/Qt-Win-4.0.1:
</p>

<pre>
QMAKE_CXX		= /usr/local/mingw/bin/i586-mingw32-g++

QMAKE_INCDIR		= /usr/local/mingw/include
QMAKE_INCDIR_QT		= /usr/local/Trolltech/Qt-Win-4.0.1/include
QMAKE_LIBDIR_QT		= /usr/local/Trolltech/Qt-Win-4.0.1/lib

QMAKE_LINK		= /usr/local/mingw/bin/i586-mingw32-g++
QMAKE_LFLAGS		= -mthreads -Wl,-enable-stdcall-fixup -Wl,-enable-auto-import \
   -Wl,-enable-runtime-pseudo-reloc -mwindows

QMAKE_DIR_SEP		= /
QMAKE_COPY		= cp
QMAKE_COPY_DIR		= cp -r
QMAKE_MOVE		= mv
QMAKE_DEL_FILE		= rm -f
QMAKE_MKDIR		= mkdir -p
QMAKE_DEL_DIR		= rm -rf

QMAKE_RC		= /usr/local/mingw/bin/i586-mingw32-windres

QMAKE_ZIP		= zip -r -9

QMAKE_STRIP		= /usr/local/mingw/i586-mingw32-strip

</pre>

<h2>Cross-Compiling</h2>

<p>
Call QMake with the new cross-compile spec (<tt>qmake -spec win32-x-g++</tt>), then it will set
the remainder automagically. You even don't need to set PATH if the spec contains
absolute paths to the MinGW cross compiler.
</p>

<h2>Left to be wished</h2>

<ul>
<li>I did not manage to configure [http://www.winehq.org Wine] in a way so that it does not crash loading complex apps.</li>
</ul>

<ul>
<li>I do not own the necessary hardware and licenses to test the same thing with MacOS/X. If you do and you find out how to do this, please let me know.</li>
</ul>