X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=Porting%2Fpumpkin.pod;h=e397b1f4ec3bdb3a3a94f4dfe9da551161a2d660;hb=6bdd71ef1830fa9fb85306405e4da0222df1321d;hp=1749b22e4b2913467dd9bd180c17f12187a4545d;hpb=05ff1fbb4c37d896ff839b1d2d6c6650cdafae98;p=p5sagit%2Fp5-mst-13.2.git diff --git a/Porting/pumpkin.pod b/Porting/pumpkin.pod index 1749b22..e397b1f 100644 --- a/Porting/pumpkin.pod +++ b/Porting/pumpkin.pod @@ -1,6 +1,6 @@ =head1 NAME -Pumpkin - Notes on handling the Perl Patch Pumpkin +Pumpkin - Notes on handling the Perl Patch Pumpkin And Porting Perl =head1 SYNOPSIS @@ -43,7 +43,7 @@ to perl5-porters-request@perl.org . Archives of the list are held at: - http://www.rosat.mpe-garching.mpg.de/mailing-lists/perl-porters/ + http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/ =head1 How are Perl Releases Numbered? @@ -103,7 +103,7 @@ always match the regular expression: C<$1> in the pattern is always an even number for maintenance versions, and odd for developer releases. -In the past it has been observed that pumkings tend to invent new +In the past it has been observed that pumpkings tend to invent new naming conventions on the fly. If you are a pumpking, before you invent a new name for any of the three types of perl distributions, please inform the guys from the CPAN who are doing indexing and @@ -159,6 +159,8 @@ settled elsewhere. If feasible, try to keep filenames 8.3-compliant to humor those poor souls that get joy from running Perl under such dire limitations. There's a script, check83.pl, for keeping your nose 8.3-clean. +In a similar vein, do not create files or directories which differ only +in case (upper versus lower). =head2 Seek consensus on major changes @@ -590,19 +592,19 @@ to change the version number near the top of the F file. =head2 Todo -The F file contains a roughly-catgorized unordered list of -aspects of Perl that could use enhancement, features that could be -added, areas that could be cleaned up, and so on. During your term as -pumpkin-holder, you will probably address some of these issues, and -perhaps identify others which, while you decide not to address them -this time around, may be tackled in the future. Update the file -reflect the situation as it stands when you hand over the pumpkin. +The F file contains a roughly-categorized unordered +list of aspects of Perl that could use enhancement, features that could +be added, areas that could be cleaned up, and so on. During your term +as pumpkin-holder, you will probably address some of these issues, and +perhaps identify others which, while you decide not to address them this +time around, may be tackled in the future. Update the file to reflect +the situation as it stands when you hand over the pumpkin. You might like, early in your pumpkin-holding career, to see if you can find champions for partiticular issues on the to-do list: an issue owned is an issue more likely to be resolved. -There are also some more porting-specific L items later in this +There are also some more porting-specific L items later in this file. =head2 OS/2-specific updates @@ -755,7 +757,7 @@ and build everything else from that with -DCHECK_FORMAT make clean make miniperl - make all OPTIMIZE=-DCHECK_FORMAT >& make.log + make all OPTIMIZE='-DCHECK_FORMAT -Wformat' >& make.log =item * @@ -769,6 +771,48 @@ clean up, and print warnings from the log files (-Wformat support by Robin Barker.) +=item gcc -ansi -pedantic + +Configure -Dgccansipedantic [ -Dcc=gcc ] will enable (via the cflags script, +not $Config{ccflags}) the gcc strict ANSI C flags -ansi and -pedantic for +the compilation of the core files on platforms where it knows it can +do so (like Linux, see cflags.SH for the full list), and on some +platforms only one (Solaris can do only -pedantic, not -ansi). +The flag -DPERL_GCC_PEDANTIC also gets added, since gcc does not add +any internal cpp flag to signify that -pedantic is being used, as it +does for -ansi (__STRICT_ANSI__). + +Note that the -ansi and -pedantic are enabled only for version 3 (and +later) of gcc, since even gcc version 2.95.4 finds lots of seemingly +false "value computed not used" errors from Perl. + +The -ansi and -pedantic are useful in catching at least the following +nonportable practices: + +=over 4 + +=item * + +gcc-specific extensions + +=item * + +lvalue casts + +=item * + +// C++ comments + +=item * + +enum trailing commas + +=back + +The -Dgccansipedantic should be used only when cleaning up the code, +not for production builds, since otherwise gcc cannot inline certain +things. + =back =head1 Running Purify @@ -1216,12 +1260,18 @@ a mail message from Larry: probably have been named something to do with overriding though. Since it's undocumented we could still change it... :-) -Given that it's already there, you can use it to override -distribution modules. If you do +Given that it's already there, you can use it to override distribution modules. +One way to do that is to add - sh Configure -Dccflags='-DAPPLLIB_EXP=/my/override' + ccflags="$ccflags -DAPPLLIB_EXP=\"/my/override\"" + +to your config.over file. (You have to be particularly careful to get the +double quotes in. APPLLIB_EXP must be a valid C string. It might +actually be easier to just #define it yourself in perl.c.) -then perl.c will put /my/override ahead of ARCHLIB and PRIVLIB. +Then perl.c will put /my/override ahead of ARCHLIB and PRIVLIB. Perl will +also search architecture-specific and version-specific subdirectories of +APPLLIB_EXP. =head2 Shared libperl.so location @@ -1279,6 +1329,21 @@ reflection, I'd say leave libperl.so in $archlib. =back +=head2 Indentation style + +Over the years Perl has become a mishmash of +various indentation styles, but the original "Larry style" can +probably be restored with (GNU) indent somewhat like this: + + indent -kr -nce -psl -sc + +A more ambitious solution would also specify a list of Perl specific +types with -TSV -TAV -THV .. -TMAGIC -TPerlIO ... but that list would +be quite ungainly. Also note that GNU indent also doesn't do aligning +of consecutive assignments, which would truly wreck the layout in +places like sv.c:Perl_sv_upgrade() or sv.c:Perl_clone_using(). +Similarly nicely aligned &&s, ||s and ==s would not be respected. + =head1 Upload Your Work to CPAN You can upload your work to CPAN if you have a CPAN id. Check out @@ -1306,6 +1371,97 @@ Here, in no particular order, are some Configure and build-related items that merit consideration. This list isn't exhaustive, it's just what I came up with off the top of my head. +=head2 Adding missing library functions to Perl + +The perl Configure script automatically determines which headers and +functions you have available on your system and arranges for them to be +included in the compilation and linking process. Occasionally, when porting +perl to an operating system for the first time, you may find that the +operating system is missing a key function. While perl may still build +without this function, no perl program will be able to reference the missing +function. You may be able to write the missing function yourself, or you +may be able to find the missing function in the distribution files for +another software package. In this case, you need to instruct the perl +configure-and-build process to use your function. Perform these steps. + +=over 3 + +=item * + +Code and test the function you wish to add. Test it carefully; you will +have a much easier time debugging your code independently than when it is a +part of perl. + +=item * + +Here is an implementation of the POSIX truncate function for an operating +system (VOS) that does not supply one, but which does supply the ftruncate() +function. + + /* Beginning of modification history */ + /* Written 02-01-02 by Nick Ing-Simmons (nick@ing-simmons.net) */ + /* End of modification history */ + + /* VOS doesn't supply a truncate function, so we build one up + from the available POSIX functions. */ + + #include + #include + #include + + int + truncate(const char *path, off_t len) + { + int fd = open(path,O_WRONLY); + int code = -1; + if (fd >= 0) { + code = ftruncate(fd,len); + close(fd); + } + return code; + } + +Place this file into a subdirectory that has the same name as the operating +system. This file is named perl/vos/vos.c + +=item * + +If your operating system has a hints file (in perl/hints/XXX.sh for an +operating system named XXX), then start with it. If your operating system +has no hints file, then create one. You can use a hints file for a similar +operating system, if one exists, as a template. + +=item * + +Add lines like the following to your hints file. The first line +(d_truncate="define") instructs Configure that the truncate() function +exists. The second line (archobjs="vos.o") instructs the makefiles that the +perl executable depends on the existence of a file named "vos.o". (Make +will automatically look for "vos.c" and compile it with the same options as +the perl source code). The final line ("test -h...") adds a symbolic link +to the top-level directory so that make can find vos.c. Of course, you +should use your own operating system name for the source file of extensions, +not "vos.c". + + # VOS does not have truncate() but we supply one in vos.c + d_truncate="define" + archobjs="vos.o" + + # Help gmake find vos.c + test -h vos.c || ln -s vos/vos.c vos.c + +The hints file is a series of shell commands that are run in the top-level +directory (the "perl" directory). Thus, these commands are simply executed +by Configure at an appropriate place during its execution. + +=item * + +At this point, you can run the Configure script and rebuild perl. Carefully +test the newly-built perl to ensure that normal paths, and error paths, +behave as you expect. + +=back + =head2 Good ideas waiting for round tuits =over 4 @@ -1400,9 +1556,80 @@ in recent config.sh files though. =back +=head2 Copyright Issues + +The following is based on the consensus of a couple of IPR lawyers, +but it is of course not a legally binding statement, just a common +sense summary. + +=over 4 + +=item * + +Tacking on copyright statements is unnecessary to begin with because +of the Berne convention. But assuming you want to go ahead... + +=item * + +The right form of a copyright statement is + + Copyright (C) Year, Year, ... by Someone + +The (C) is not required everywhere but it doesn't hurt and in certain +jurisdictions it is required, so let's leave it in. (Yes, it's true +that in some jurisdictions the "(C)" is not legally binding, one should +use the true ringed-C. But we don't have that character available for +Perl's source code.) + +The years must be listed out separately. Year-Year is not correct. +Only the years when the piece has changed 'significantly' may be added. + +=item * + +One cannot give away one's copyright trivially. One can give one's +copyright away by using public domain, but even that requires a little +bit more than just saying 'this is in public domain'. (What it +exactly requires depends on your jurisdiction.) But barring public +domain, one cannot "transfer" one's copyright to another person or +entity. In the context of software, it means that contributors cannot +give away their copyright or "transfer" it to the "owner" of the software. + +Also remember that in many cases if you are employed by someone, +your work may be copyrighted to your employer, even when you are +contributing on your own time (this all depends on too many things +to list here). But the bottom line is that you definitely can't give +away a copyright you may not even have. + +What is possible, however, is that the software can simply state + + Copyright (C) Year, Year, ... by Someone and others + +and then list the "others" somewhere in the distribution. +And this is exactly what Perl does. (The "somewhere" is +AUTHORS and the Changes* files.) + +=item * + +Split files, merged files, and generated files are problematic. +The rule of thumb: in split files, copy the copyright years of +the original file to all the new files; in merged files make +an union of the copyright years of all the old files; in generated +files propagate the copyright years of the generating file(s). + +=item * + +The files of Perl source code distribution do carry a lot of +copyrights, by various people. (There are many copyrights embedded in +perl.c, for example.) The most straightforward thing for pumpkings to +do is to simply update Larry's copyrights at the beginning of the +*.[hcy], x2p/*.[hcy], *.pl, and README files, and leave all other +copyrights alone. Doing more than that requires quite a bit of tracking. + +=back + =head1 AUTHORS -Original author: Andy Dougherty doughera@lafcol.lafayette.edu . +Original author: Andy Dougherty doughera@lafayette.edu . Additions by Chip Salzenberg chip@perl.com and Tim Bunce Tim.Bunce@ig.co.uk .