Coding Practice This chapter describes the relevant coding practices in Wine, that you should be aware of before doing any serious development in Wine. Patch Format Patches are submitted via email to the Wine patches mailing list, wine-patches@winehq.org. Your patch should include: A meaningful subject (very short description of patch) A long (paragraph) description of what was wrong and what is now better. (recommended) A change log entry (short description of what was changed). The patch in diff -u format cvs diff -u works great for the common case where a file is edited. However, if you add or remove a file cvs diff will not report that correctly so make sure you explicitly take care of this rare case. For additions simply include them by appending the diff -u /dev/null /my/new/file output of them to any cvs diff -u output you may have. Alternatively, use diff -Nu olddir/ newdir/ in case of multiple new files to add. For removals, clearly list the files in the description of the patch. Since wine is constantly changing due to development it is strongly recommended that you use cvs for patches, if you cannot use cvs for some reason, you can submit patches against the latest tarball. To do this make a copy of the files that you will be modifying and diff -u against the old file. I.E. diff -u file.old file.c > file.txt Some notes about style There are a few conventions that about coding style that have been adopted over the years of development. The rational for these rules is explained for each one. No HTML mail, since patches should be in-lined and HTML turns the patch into garbage. Also it is considered bad etiquette as it uglifies the message, and is not viewable by many of the subscribers. Only one change set per patch. Patches should address only one bug/problem at a time. If a lot of changes need to be made then it is preferred to break it into a series of patches. This makes it easier to find regressions. Tabs are not forbidden but discouraged. A tab is defined as 8 characters and the usual amount of indentation is 4 characters. C++ style comments are discouraged since some compilers choke on them. Commenting out a block of code is usually done by enclosing it in #if 0 ... #endif Statements. For example. /* note about reason for commenting block */ #if 0 code code /* comments */ code #endif The reason for using this method is that it does not require that you edit comments that may be inside the block of code. Patches should be in-lined (if you can configure your email client to not wrap lines), or attached as plain text attachments so they can be read inline. This may mean some more work for you. However it allows others to review your patch easily and decreases the chances of it being overlooked or forgotten. Code is usually limited to 80 columns. This helps prevent mailers mangling patches by line wrap. Also it generally makes code easier to read. If the patch fixes a bug in Bugzilla please provide a link to the bug in the comments of the patch. This will make it easier for the maintainers of Bugzilla. Inline attachments with Outlook Express Outlook Express is notorious for mangling attachments. Giving the patch a .txt extension and attaching will solve the problem for most mailers including Outlook. Also, there is a way to enable Outlook Express send .diff attachments. You need following two things to make it work. Make sure that .diff files have \r\n line ends, because if OE detects that there is no \r\n line endings it switches to quoted-printable format attachments. Using regedit add key "Content Type" with value "text/plain" to the .diff extension under HKEY_CLASSES_ROOT (same as for .txt extension). This tells OE to use Content-Type: text/plain instead of application/octet-stream. Item #1 is important. After you hit "Send" button, go to "Outbox" and using "Properties" verify the message source to make sure that the mail has correct format. You might want to send several test emails to yourself too. Alexandre's Bottom Line The basic rules are: no attachments, no MIME crap, no line wrapping, a single patch per mail. Basically if I can't do "cat raw_mail | patch -p0" it's in the wrong format. Quality Assurance (Or, "How do I get Alexandre to apply my patch quickly so I can build on it and it will not go stale?") Make sure your patch applies to the current CVS head revisions. If a bunch of patches are committed to CVS that may affect whether your patch will apply cleanly then verify that your patch does apply! cvs update is your friend! Save yourself some embarrassment and run your patched code against more than just your current test example. Experience will tell you how much effort to apply here. If there are any conformance tests for the code you're working on, run them and make sure they still pass after your patch is applied. Running tests can be done by running make test. You may need to run make testclean to undo the results of a previous test run. See the testing guide for more details on Wine's conformance tests. Porting Wine to new Platforms This document provides a few tips on porting Wine to your favorite (UNIX-based) operating system. Why <symbol>#ifdef MyOS</symbol> is probably a mistake. Operating systems change. Maybe yours doesn't have the foo.h header, but maybe a future version will have it. If you want to #include <foo.h>, it doesn't matter what operating system you are using; it only matters whether foo.h is there. Furthermore, operating systems change names or "fork" into several ones. An #ifdef MyOs will break over time. If you use the feature of autoconf -- the Gnu auto-configuration utility -- wisely, you will help future porters automatically because your changes will test for features, not names of operating systems. A feature can be many things: existence of a header file existence of a library function existence of libraries bugs in header files, library functions, the compiler, ... You will need Gnu Autoconf, which you can get from your friendly Gnu mirror. This program takes Wine's configure.ac file and produces a configure shell script that users use to configure Wine to their system. There are exceptions to the "avoid #ifdef MyOS" rule. Wine, for example, needs the internals of the signal stack -- that cannot easily be described in terms of features. Moreover, you can not use autoconf's HAVE_* symbols in Wine's headers, as these may be used by Winelib users who may not be using a configure script. Let's now turn to specific porting problems and how to solve them. MyOS doesn't have the <filename>foo.h</filename> header! This first step is to make autoconf check for this header. In configure.in you add a segment like this in the section that checks for header files (search for "header files"): AC_CHECK_HEADER(foo.h, AC_DEFINE(HAVE_FOO_H)) If your operating system supports a header file with the same contents but a different name, say bar.h, add a check for that also. Now you can change #include <foo.h> to #ifdef HAVE_FOO_H #include <foo.h> #elif defined (HAVE_BAR_H) #include <bar.h> #endif If your system doesn't have a corresponding header file even though it has the library functions being used, you might have to add an #else section to the conditional. Avoid this if you can. You will also need to add #undef HAVE_FOO_H (etc.) to include/config.h.in Finish up with make configure and ./configure. MyOS doesn't have the <function>bar</function> function! A typical example of this is the memmove function. To solve this problem you would add memmove to the list of functions that autoconf checks for. In configure.in you search for AC_CHECK_FUNCS and add memmove. (You will notice that someone already did this for this particular function.) Secondly, you will also need to add #undef HAVE_BAR to include/config.h.in The next step depends on the nature of the missing function. Case 1: It's easy to write a complete implementation of the function. (memmove belongs to this case.) You add your implementation in misc/port.c surrounded by #ifndef HAVE_MEMMOVE and #endif. You might have to add a prototype for your function. If so, include/miscemu.h might be the place. Don't forget to protect that definition by #ifndef HAVE_MEMMOVE and #endif also! Case 2: A general implementation is hard, but Wine is only using a special case. An example is the various wait calls used in SIGNAL_child from loader/signal.c. Here we have a multi-branch case on features: #ifdef HAVE_THIS ... #elif defined (HAVE_THAT) ... #elif defined (HAVE_SOMETHING_ELSE) ... #endif Note that this is very different from testing on operating systems. If a new version of your operating systems comes out and adds a new function, this code will magically start using it. Finish up with make configure and ./configure. Adding New Languages This file documents the necessary procedure for adding a new language to the list of languages that Wine can display system menus and forms in. Adding new translations is not hard as it requires no programming knowledge or special skills. Language dependent resources reside in files named somefile_Xx.rc or Xx.rc, where Xx is your language abbreviation (look for it in include/winnls.h). These are included in a master file named somefile.rc or rsrc.rc, located in the same directory as the language files. To add a new language to one of these resources you need to make a copy of the English resource (located in the somefile_En.rc file) over to your somefile_Xx.rc file, include this file in the master somefile.rc file, and edit the new file to translate the English text. You may also need to rearrange some of the controls to better fit the newly translated strings. Test your changes to make sure they properly layout on the screen. In menus, the character "&" means that the next character will be highlighted and that pressing that letter will select the item. You should place these "&" characters suitably for your language, not just copy the positions from English. In particular, items within one menu should have different highlighted letters. To get a list of the files that need translating, run the following command in the root of your Wine tree: find -name "*En.rc". When adding a new language, also make sure the parameters defined in ./dlls/kernel/nls/*.nls fit your local habits and language.