diff --git a/en_US.ISO8859-1/books/developers-handbook/introduction/chapter.sgml b/en_US.ISO8859-1/books/developers-handbook/introduction/chapter.sgml index 3140878c92..94cc1f5291 100644 --- a/en_US.ISO8859-1/books/developers-handbook/introduction/chapter.sgml +++ b/en_US.ISO8859-1/books/developers-handbook/introduction/chapter.sgml @@ -1,231 +1,231 @@ Murray Stokely Contributed by Jeroen Ruigrok van der Werven Introduction Developing on FreeBSD So here we are. System all installed and you are ready to start programming. But where to start? What does FreeBSD provide? What can it do for me, as a programmer? These are some questions which this chapter tries to answer. Of course, programming has different levels of proficiency like any other trade. For some it is a hobby, for others it is their profession. The information in this chapter might be aimed toward the beginning programmer; indeed, it could serve useful for the programmer unfamiliar with the &os; platform. The BSD Vision To produce the best &unix; like operating system package possible, with due respect to the original software tools ideology as well as usability, performance and stability. Architectural Guidelines Our ideology can be described by the following guidelines Do not add new functionality unless an implementor cannot complete a real application without it. It is as important to decide what a system is not as to decide what it is. Do not serve all the world's needs; rather, make the system extensible so that additional needs can be met in an upwardly compatible fashion. The only thing worse than generalizing from one example is generalizing from no examples at all. If a problem is not completely understood, it is probably best to provide no solution at all. If you can get 90 percent of the desired effect for 10 percent of the work, use the simpler solution. Isolate complexity as much as possible. Provide mechanism, rather than policy. In particular, place user interface policy in the client's hands. From Scheifler & Gettys: "X Window System" The Layout of <filename class="directory">/usr/src</filename> The complete source code to FreeBSD is available from our - public CVS repository. The source code is normally installed in + public repository. The source code is normally installed in /usr/src which contains the following subdirectories: Directory Description bin/ Source for files in /bin cddl/ Utilities covered by the Common Development and Distribution License contrib/ Source for files from contributed software. crypto/ Cryptographical sources etc/ Source for files in /etc games/ Source for files in /usr/games gnu/ Utilities covered by the GNU Public License include/ Source for files in /usr/include kerberos5/ Source for Kerberos version 5 lib/ Source for files in /usr/lib libexec/ Source for files in /usr/libexec release/ Files required to produce a FreeBSD release rescue/ Build system for the /rescue utilities sbin/ Source for files in /sbin secure/ FreeSec sources share/ Source for files in /usr/share sys/ Kernel source files tools/ Tools used for maintenance and testing of FreeBSD usr.bin/ Source for files in /usr/bin usr.sbin/ Source for files in /usr/sbin diff --git a/en_US.ISO8859-1/books/developers-handbook/policies/chapter.sgml b/en_US.ISO8859-1/books/developers-handbook/policies/chapter.sgml index 3c37d8d4dc..c474d3a233 100644 --- a/en_US.ISO8859-1/books/developers-handbook/policies/chapter.sgml +++ b/en_US.ISO8859-1/books/developers-handbook/policies/chapter.sgml @@ -1,709 +1,709 @@ Poul-Henning Kamp Contributed by Giorgos Keramidas Source Tree Guidelines and Policies This chapter documents various guidelines and policies in force for the FreeBSD source tree. <makevar>MAINTAINER</makevar> on Makefiles ports maintainer If a particular portion of the &os; src/ distribution is being maintained by a person or group of persons, this is communicated through an entry in the src/MAINTAINERS file. Maintainers of ports within the Ports Collection express their maintainership to the world by adding a MAINTAINER line to the Makefile of the port in question: MAINTAINER= email-addresses For other parts of the repository, or for sections not listed as having a maintainer, or when you are unsure who the active maintainer is, try looking at the recent commit history of the relevant parts of the source tree. It is quite often the case that a maintainer is not explicitly named, but the people who are actively working in a part of the source tree for, say, the last couple of years are interested in reviewing changes. Even if this is not specifically mentioned in the documentation or the source itself, asking for a review as a form of courtesy is a very reasonable thing to do. The role of the maintainer is as follows: The maintainer owns and is responsible for that code. This means that he or she is responsible for fixing bugs and answering problem reports pertaining to that piece of the code, and in the case of contributed software, for tracking new versions, as appropriate. Changes to directories which have a maintainer defined shall be sent to the maintainer for review before being committed. Only if the maintainer does not respond for an unacceptable period of time, to several emails, will it be acceptable to commit changes without review by the maintainer. However, it is suggested that you try to have the changes reviewed by someone else if at all possible. It is of course not acceptable to add a person or group as maintainer unless they agree to assume this duty. On the other hand it does not have to be a committer and it can easily be a group of people. Poul-Henning Kamp Contributed by David O'Brien Gavin Atkinson Contributed Software contributed software Some parts of the FreeBSD distribution consist of software that is actively being maintained outside the FreeBSD project. For historical reasons, we call this contributed software. Some examples are sendmail, gcc and patch. Over the last couple of years, various methods have been used in dealing with this type of software and all have some number of advantages and drawbacks. No clear winner has emerged. Since this is the case, after some debate one of these methods has been selected as the official method and will be required for future imports of software of this kind. Furthermore, it is strongly suggested that existing contributed software converge on this model over time, as it has significant advantages over the old method, including the ability to easily obtain diffs relative to the official versions of the source by everyone (even without direct repository access). This will make it significantly easier to return changes to the primary developers of the contributed software. Ultimately, however, it comes down to the people actually doing the work. If using this model is particularly unsuited to the package being dealt with, exceptions to these rules may be granted only with the approval of the core team and with the general consensus of the other developers. The ability to maintain the package in the future will be a key issue in the decisions. Because of some unfortunate design limitations with the RCS file format and the use of vendor branches, minor, trivial and/or cosmetic changes are strongly discouraged on files that are still tracking the vendor branch. Spelling fixes are explicitly included here under the cosmetic category and are to be avoided. The repository bloat impact from a single character change can be rather dramatic. Vendor Imports with CVS The file utility, used to identify the format of a file, will be used as example of how this model works: src/contrib/file contains the source as distributed by the maintainers of this package. Parts that are entirely not applicable for &os; can be removed. In the case of &man.file.1;, the python subdirectory and files with the lt prefix were eliminated before the import, amongst others. src/lib/libmagic contains a bmake style Makefile that uses the standard bsd.lib.mk makefile rules to produce the library and install the documentation. src/usr.bin/file contains a bmake style Makefile which will produce and install the file program and its associated man-pages using the standard bsd.prog.mk rules. The important thing here is that the src/contrib/file directory is created according to the rules: it is supposed to contain the sources as distributed (on a proper vendor-branch and without RCS keyword expansion) with as few FreeBSD-specific changes as possible. If there are any doubts on how to go about it, it is imperative that you ask first and not blunder ahead and hope it works out. Because of the previously mentioned design limitations with vendor branches, it is required that official patches from the vendor be applied to the original distributed sources and the result re-imported onto the vendor branch again. Official patches should never be patched into the FreeBSD checked out version and committed, as this destroys the vendor branch coherency and makes importing future versions rather difficult as there will be conflicts. Since many packages contain files that are meant for compatibility with other architectures and environments than FreeBSD, it is permissible to remove parts of the distribution tree that are of no interest to FreeBSD in order to save space. Files containing copyright notices and release-note kind of information applicable to the remaining files shall not be removed. If it seems easier, the bmake Makefiles can be produced from the dist tree automatically by some utility, something which would hopefully make it even easier to upgrade to a new version. If this is done, be sure to check in such utilities (as necessary) in the src/tools directory along with the port itself so that it is available to future maintainers. In the src/contrib/file level directory, a file called FREEBSD-upgrade should be added and it should state things like: Which files have been left out. Where the original distribution was obtained from and/or the official master site. Where to send patches back to the original authors. Perhaps an overview of the FreeBSD-specific changes that have been made. Example wording from src/contrib/groff/FREEBSD-upgrade is below: $FreeBSD: src/contrib/groff/FREEBSD-upgrade,v 1.5.12.1 2005/11/15 22:06:18 ru Exp $ This directory contains virgin copies of the original distribution files on a "vendor" branch. Do not, under any circumstances, attempt to upgrade the files in this directory via patches and a cvs commit. To upgrade to a newer version of groff, when it is available: 1. Unpack the new version into an empty directory. [Do not make ANY changes to the files.] 2. Use the command: cvs import -m 'Virgin import of FSF groff v<version>' \ src/contrib/groff FSF v<version> For example, to do the import of version 1.19.2, I typed: cvs import -m 'Virgin import of FSF groff v1.19.2' \ src/contrib/groff FSF v1_19_2 3. Follow the instructions printed out in step 2 to resolve any conflicts between local FreeBSD changes and the newer version. Do not, under any circumstances, deviate from this procedure. To make local changes to groff, simply patch and commit to the main branch (aka HEAD). Never make local changes on the FSF branch. All local changes should be submitted to Werner Lemberg <wl@gnu.org> or Ted Harding <ted.harding@nessie.mcc.ac.uk> for inclusion in the next vendor release. ru@FreeBSD.org - 20 October 2005 Another approach my also be taken for the list of files to be excluded, which is especially useful when the list is large or complicated or where imports happen frequently. By creating a file FREEBSD-Xlist in the same directory the vendor source is imported into, containing a list of filename patterns to be excluded one per line, future imports can often performed with: &prompt.user; tar FREEBSD-Xlist vendor-source.tgz An example of a FREEBSD-Xlist file, from src/contrib/tcsh, is here: */BUGS */config/a* */config/bs2000 */config/bsd */config/bsdreno */config/[c-z]* */tests */win32 Please do not import FREEBSD-upgrade or FREEBSD-Xlist with the contributed source. Rather you should add these files after the initial import. Dag-Erling Smørgrav Contributed by Vendor Imports with SVN This section describes the vendor import procedure with Subversion in details. Preparing the Tree If this is your first import after the switch to SVN, you will have to flatten and clean up the vendor tree, and bootstrap merge history in the main tree. If not, you can safely omit this step. During the conversion from CVS to SVN, vendor branches were imported with the same layout as the main tree. For example, the foo vendor sources ended up in vendor/foo/dist/contrib/foo, but it is pointless and rather inconvenient. What we really want is to have the vendor source directly in vendor/foo/dist, like this: &prompt.user; cd vendor/foo/dist/contrib/foo &prompt.user; svn move $(svn list) ../.. &prompt.user; cd ../.. &prompt.user; svn remove contrib &prompt.user; svn propdel svn:mergeinfo &prompt.user; svn commit Note that, the propdel bit is necessary because starting with 1.5, Subversion will automatically add svn:mergeinfo to any directory you copy or move. In this case, you will not need this information, since you are not going to merge anything from the tree you deleted. You may want to flatten the tags as well. The procedure is exactly the same. If you do this, put off the commit until the end. Check the dist tree and perform any cleanup that is deemed to be necessary. You may want to disable keyword expansion, as it makes no sense on unmodified vendor code. In some cases, it can be even be harmful. &prompt.user; svn propdel svn:keywords . &prompt.user; svn commit Bootstrapping of svn:mergeinfo on the target directory (in the main tree) to the revision that corresponds to the last change was made to the vendor tree prior to importing new sources is also needed: &prompt.user; cd head/contrib/foo &prompt.user; svn merge svn_base/vendor/foo/dist@12345678 . &prompt.user; svn commit where svn_base is the base directory of your SVN repository, e.g. svn+ssh://svn.FreeBSD.org/base. Importing New Sources Prepare a full, clean tree of the vendor sources. With SVN, we can keep a full distribution in the vendor tree without bloating the main tree. Import everything but merge only what is needed. Note that you will need to add any files that were added since the last vendor import, and remove any that were removed. To facilitate this, you should prepare sorted lists of the contents of the vendor tree and of the sources you are about to import: &prompt.user; cd vendor/foo/dist &prompt.user; svn list | grep '/$' | sort > ../old &prompt.user; cd ../foo-9.9 &prompt.user; find . f | cut 3- | sort > ../new With these two files, the following command will list list removed files (files only in old): &prompt.user; comm ../old ../new While the command below will list added files (files only in new): &prompt.user; comm ../old ../new Let's put this together: &prompt.user; cd vendor/foo/foo-9.9 &prompt.user; tar cf - . | tar xf - ../dist &prompt.user; cd ../dist &prompt.user; comm ../old ../new | xargs svn remove &prompt.user; comm ../old ../new | xargs svn add If there are new directories in the new distribution, the last command will fail. You will have to add the directories, and run it again. Conversely, if any directories were removed, you will have to remove them manually. Check properties on any new files: All text files should have svn:eol-style set to native. All binary files should have svn:mime-type set to application/octet-stream, unless there is a more appropriate media type. Executable files should have svn:executable set to *. There should be no other properties on any file in the tree. You are ready to commit, but you should first check the output of svn stat and svn diff to make sure everything is in order. Once you have committed the new vendor release, you should tag it for future reference. The best and quickest way is to do it directly in the repository: &prompt.user; svn copy svn_base/vendor/foo/dist svn_base/vendor/foo/9.9 To get the new tag, you can update your working copy of vendor/foo. If you choose to do the copy in the checkout instead, do not forget to remove the generated svn:mergeinfo as described above. Merging to <emphasis>-HEAD</emphasis> After you have prepared your import, it is time to merge. Option tells SVN not to handle merge conflicts yet, because they will be taken care of manually: &prompt.user; cd head/contrib/foo &prompt.user; svn update &prompt.user; svn merge svn_base/vendor/foo/dist Resolve any conflicts, and make sure that any files that were added or removed in the vendor tree have been properly added or removed in the main tree. It is always a good idea to check differences against the vendor branch: &prompt.user; svn diff svn_base/vendor/foo/dist . The option tells SVN not to check files that are in the vendor tree but not in the main tree. With SVN, there is no concept of on or off the vendor branch. If a file that previously had local modifications no longer does, just remove any left-over cruft, such as &os; version tags, so it no longer shows up in diffs against the vendor tree. If any changes are required for the world to build with the new sources, make them now — and test until you are satisfied that everything build and runs correctly. Commit Now, you are ready to commit. Make sure you get everything in one go. Ideally, you would have done all steps in a clean tree, in which case you can just commit from the top of that tree. That is the best way to avoid surprises. If you do it properly, the tree will move atomically from a consistent state with the old code to a consistent state with the new code. Encumbered Files It might occasionally be necessary to include an encumbered file in the FreeBSD source tree. For example, if a device requires a small piece of binary code to be loaded to it before the device will operate, and we do not have the source to that code, then the binary file is said to be encumbered. The following policies apply to including encumbered files in the FreeBSD source tree. Any file which is interpreted or executed by the system CPU(s) and not in source format is encumbered. Any file with a license more restrictive than BSD or GNU is encumbered. A file which contains downloadable binary data for use by the hardware is not encumbered, unless (1) or (2) apply to it. It must be stored in an architecture neutral ASCII format (file2c or uuencoding is recommended). Any encumbered file requires specific approval from the Core Team before it is added to the - CVS repository. + repository. Encumbered files go in src/contrib or src/sys/contrib. The entire module should be kept together. There is no point in splitting it, unless there is code-sharing with non-encumbered code. Object files are named arch/filename.o.uu>. Kernel files: Should always be referenced in conf/files.* (for build simplicity). Should always be in LINT, but the Core Team decides per case if it should be commented out or not. The Core Team can, of course, change their minds later on. The Release Engineer decides whether or not it goes into the release. User-land files: core team The Core team decides if the code should be part of make world. release engineering The Release Engineering decides if it goes into the release. Satoshi Asami Contributed by Peter Wemm David O'Brien Shared Libraries If you are adding shared library support to a port or other piece of software that does not have one, the version numbers should follow these rules. Generally, the resulting numbers will have nothing to do with the release version of the software. The three principles of shared library building are: Start from 1.0 If there is a change that is backwards compatible, bump minor number (note that ELF systems ignore the minor number) If there is an incompatible change, bump major number For instance, added functions and bugfixes result in the minor version number being bumped, while deleted functions, changed function call syntax, etc. will force the major version number to change. Stick to version numbers of the form major.minor (x.y). Our a.out dynamic linker does not handle version numbers of the form x.y.z well. Any version number after the y (i.e. the third digit) is totally ignored when comparing shared lib version numbers to decide which library to link with. Given two shared libraries that differ only in the micro revision, ld.so will link with the higher one. That is, if you link with libfoo.so.3.3.3, the linker only records 3.3 in the headers, and will link with anything starting with libfoo.so.3.(anything >= 3).(highest available). ld.so will always use the highest minor revision. For instance, it will use libc.so.2.2 in preference to libc.so.2.0, even if the program was initially linked with libc.so.2.0. In addition, our ELF dynamic linker does not handle minor version numbers at all. However, one should still specify a major and minor version number as our Makefiles do the right thing based on the type of system. For non-port libraries, it is also our policy to change the shared library version number only once between releases. In addition, it is our policy to change the major shared library version number only once between major OS releases (i.e. from 6.0 to 7.0). When you make a change to a system library that requires the version number to be bumped, check the Makefile's commit logs. It is the responsibility of the committer to ensure that the first such change since the release will result in the shared library version number in the Makefile to be updated, and any subsequent changes will not.