documentation/winelib-mfc.sgml

  <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>

  </chapter>

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