Sweden-Number/documentation/winelib-mfc.sgml

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<chapter id="mfc">
<title id="mfc.title">Dealing with the MFC</title>
<sect1 id="mfc-introduction">
<title id="mfc-introduction.title">Introduction</title>
<para>
To use the MFC in a Winelib application you will first have to
recompile the MFC with Winelib. In theory it should be possible to
write a wrapper for the Windows MFC as described in
<xref linkend="bindlls" endterm="bindlls.title">. But in practice
it does not seem to be a realistic approach for the MFC:
</para>
<itemizedlist>
<listitem>
<para>
the huge number of APIs makes writing the wrapper a big task in
itself.
</para>
</listitem>
<listitem>
<para>
furthermore the MFC contain a huge number of APIs which are tricky
to deal with when making a wrapper.
</para>
</listitem>
<listitem>
<para>
even once you have written the wrapper you will need to modify
the MFC headers so that the compiler does not choke on them.
</para>
</listitem>
<listitem>
<para>
a big part of the MFC code is actually in your application in
the form of macros. This means even more of the MFC headers have
to actually work to in order for you to be able to compile an
MFC based application.
</para>
</listitem>
</itemizedlist>
<para>
This is why this guide includes a section dedicated to helping you
compile the MFC with Winelib.
</para>
</sect1>
<sect1 id="mfc-legal-issues">
<title id="mfc-legal-issues.title">Legal issues</title>
<para>
The purpose of this section is to make you aware of potential legal
problems. Be sure to read your licenses and to consult your lawyers.
In any case you should not consider the remainder of this section to
be authoritative since it has not been written by a lawyer.
</para>
<para>
During the compilation of your program, you will be combining code
from several sources: your code, Winelib code, Microsoft MFC code,
and possibly code from other vendor sources. As a result, you must
ensure that the licenses of all code sources are obeyed. What you are
allowed and not allowed to do can vary depending on how you combine
the code and if you will be distributing it. For example, if you
are releasing your code under the GPL or LGPL, you cannot use MFC
because these licenses do not allow covered code to depend on
libraries with non-compatible licenses.
There is a workaround - in the license for your
code you can make an exception for the MFC library.
For details see
<ulink url="http://www.gnu.org/licenses/gpl-faq.html">The GNU GPL FAQ</ulink>.
</para>
<para>
Wine/Winelib is distributed under the GNU Lesser General Public
License. See the license for restrictions on the modification and
distribution of Wine/Winelib code. In general it is possible to
satisfy these restrictions in any type of application.
On the other hand, MFC
is distributed under a very restrictive license and the restrictions
vary from version to version and between service packs. There are
basically three aspects you must be aware of when using the MFC.
</para>
<para>
First you must legally get MFC source code on your computer. The MFC
source code comes as a part of Visual Studio. The license for
Visual Studio implies it is a single product that can not
be broken up into its components. So the cleanest way to get MFC on
your system is to buy Visual Studio and install it on a dual boot
Linux box.
</para>
<para>
Then you must check that you are allowed to recompile MFC on a
non-Microsoft operating system! This varies with the version of MFC.
The MFC license from Visual Studio 6.0 reads in part:
</para>
<blockquote>
<para>
1.1 General License Grant. Microsoft grants to you as an
individual, a personal, nonexclusive license to make and use
copies of the SOFTWARE PRODUCT for the sole purposes of designing,
developing, and testing your software product(s) that are designed
to operate in conjunction with any Microsoft operating system
product. [Other unrelated stuff deleted.]
</para>
</blockquote>
<para>
So it appears you cannot even compile MFC for Winelib using this
license. Fortunately the Visual Studio 6.0 service pack 3 license
reads (the Visual Studio 5.0 license is similar):
</para>
<blockquote>
<para>
1.1 General License Grant. Microsoft grants to you as an
individual, a personal, nonexclusive license to make and use
copies of the SOFTWARE PRODUCT for the purpose of designing,
developing, and testing your software product(s). [Other unrelated
stuff deleted]
</para>
</blockquote>
<para>
So under this license it appears you can compile MFC for Winelib.
</para>
<para>
Finally you must check whether you have the right to distribute an
MFC library. Check the relevant section of the license on
<quote>redistributables and your redistribution rights</quote>. The
license seems to specify that you only have the right to distribute
binaries of the MFC library if it has no debug information and if
you distribute it with an application that provides significant
added functionality to the MFC library.
<!-- FIXME: quote relevant sections of EULA in above paragraph. -->
</para>
</sect1>
<sect1 id="mfc-compiling">
<title id="mfc-compiling.title">Compiling the MFC</title>
<para>
Here is a set of recommendations for getting the MFC compiled with
WineLib:
</para>
<para>
We recommend running winemaker in
'<option>--interactive</option>' mode to specify the right
options for the MFC and the ATL part (to get the include paths
right, to not consider the MFC MFC-based, and to get it to
build libraries, not executables).
</para>
<para>
Then when compiling it you will indeed need a number of
<literal>_AFX_NO_XXX</literal> macros. But this is not enough
and there are other things you will need to
'<literal>#ifdef</literal>-out'. For instance Wine's richedit
support is not very good. Here are the AFX options I use:
</para>
<para>
<programlisting>
#define _AFX_PORTABLE
#define _FORCENAMELESSUNION
#define _AFX_NO_DAO_SUPPORT
#define _AFX_NO_DHTML_SUPPORT
#define _AFX_NO_OLEDB_SUPPORT
#define _AFX_NO_RICHEDIT_SUPPORT
</programlisting>
</para>
<para>
You will also need custom ones for
<function>CMonikerFile</function>, <function>OleDB</function>,
<function>HtmlView</function>, ...
</para>
<para>
We recommend using Wine's msvcrt headers (<literal>-isystem
$(WINE_INCLUDE_ROOT)/msvcrt</literal>), though it means you
will have to temporarily disable winsock support
(<literal>#ifdef</literal> it out in
<filename>windows.h</filename>).
</para>
<para>
You should use g++ compiler more recent than g++ 2.95. g++
2.95 does not support unnamed structs while the more recent
ones do, and this helps a lot. Here are the options worth
mentioning:
<itemizedlist>
<listitem>
<para>
<literal>-fms-extensions</literal> (helps get more code
to compile)
</para>
</listitem>
<listitem>
<para>
<literal>-fshort-wchar -DWINE_UNICODE_NATIVE</literal>
(helps with Unicode support)
</para>
</listitem>
<listitem>
<para>
<literal>-DICOM_USE_COM_INTERFACE_ATTRIBUTE</literal>
(to get the COM code to work)
</para>
</listitem>
</itemizedlist>
</para>
<para>
When you first reach the link stage you will get a lot of
undefined symbol errors. To fix these you will need to go back
to the source and <literal>#ifdef</literal>-out more code
until you reach a 'closure'. There are also some files that
don't need to be compiled.
</para>
<para>
Maybe we will have ready-made makefile here someday...
</para>
</sect1>
<sect1 id="mfc-using">
<title id="mfc-using.title">Using the MFC</title>
<para>
</para>
<para>
Specific winemaker options,
the configure options,
the initialization problem...
</para>
</sect1>
</chapter>
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