- Jarkko's How to build Configure tweaked by Nick and Merijn.
+ Jarkko's How to build Configure tweaked by Nick and Merijn, and now
+ maintained by perl5-metaconfig
The Configure script and config_h.SH file in the Perl distribution are
-generated by a program called metaconfig. Metaconfig was originally
+generated by a program called metaconfig. Metaconfig was originally
written by Larry Wall, and was subsequently enhanced and maintained
by Raphael Manfredi. The binary that invokes the generation of the
Configure file is called mconfig.
You have presumably obtained the metaconfig from the repository e.g.
- $ git clone github.com:perl5-metaconfig/metaconfig metaconfig
+ $ git clone github.com:Perl/metaconfig metaconfig
When working with metaconfig you will generally have two git checkouts
next to each other: (1) this metaconfig checkout; and (2) a checkout of
$ cd metaconfig
$ ln -s ../perl perl
+We will do the reverse symlinks later.
+
Contents of this directory:
README: This file.
U: Metaconfig units used for building Perl's Configure
- U.check: Sample directory used for testing new metaconfig units.
- see U.check/README for more information.
dist-git:
a git clone of "dist". Optionally present. See (a) below.
This is where dist/meta resides as of 2016-04-01
These may differ from dist-git, as upstream also moves
on and develops.
-(a) You need to have dist installed so that you have metalint and metaconfig
- in your $PATH. As dist/meta binaries are now included in the git checkout,
- you do NOT need to install dist/meta itself.
+Development workflow:
+
+(a) In order to assemble Configure from its units, you need mlint/metaline and
+ mconfig/metaconfig from the "dist" package installed and available in your
+ $PATH. You can either use the version that comes with your OS (Debian ships
+ it) or the versions that are included in this checkout: just add the full
+ name of this folder/bin to your $PATH. If you are not planning to analyse
+ differences of the current state with upstream dist, you can skip the rest
+ op step (a) now.
If you also want to play with or compare to the original meta/dist, you
can checkout that too.
There are some perl specific "dist units" in the 'U' directory.
The U directory also contains some patches to 'dist' which have already
been applied to dist-3.5-20 directory.
- We have not yet arranged for metaconfig to use perl's versions of the
+
+(aa) We have not yet arranged for metaconfig to use perl's versions of the
'units' by default so you need some housekeeping in the perl directory...
Then add metaconfig/bin to your $PATH or create aliases like
examples in the rest of this README will just refer to mlint and mconfig
as if they appear in your $PATH
-(aa)
+(aaa)
If you plan to make changes to mconfig or mlint locally (and you might
want to, as both are written for perl4), consider installing mconfig and
non-autoloading versions and can easily be changed. As these are used by
all team members, please communicate changes on github first.
-(b) You need to be in the 'perl' checkout directory, which you created the symbolic
- link for in preparation. In this working directory, you need symbolic
- links too, which are already known to perl itself to ignore. Assuming
- you have metaconfig and perl side by side on the same level:
- 1) have a symlink to ../metaconfig/U called U
- 2) have a symlink to ../metaconfig/.package called .package
- 3) have a symlink to MANIFEST called MANIFEST.new
- 4) chmod +w Configure config_h.SH Porting/Glossary Porting/config*
-
-(c) Write the new unit as U/perl/d_bar.U ('perl' can also be 'modified',
- 'compline' or any other existing folder, except for 'all'). Choose
- the best appropriate subdir of U. See U/README for a description of
- the various subdirectories.)
+(b) You need to be in the 'perl' checkout directory, which you created the
+ symbolic link to, in preparation. In this working directory, you need
+ symbolic links too, which are already known to perl itself to ignore.
+ Assuming you have metaconfig and perl side by side on the same level:
+ ln -s ../metaconfig/U U
+ ln -s ../metaconfig/.package .package
+ ln -s MANIFEST MANIFEST.new
+ chmod +w Configure config_h.SH Porting/Glossary Porting/config*
+
+(c) Create a new file for the new unit as U/foo/d_bar.U
+ ('foo' is one of the existing folders in U except for 'all'. It most
+ likely will be 'perl', but it could also be 'modified', 'compline' or any
+ other existing folder). Choose the best appropriate subdir of U. See
+ U/README for a description of the various subdirectories.) You should
+ choose the closest existing unit file as a starting point, and first copy
+ it to the new file. For example, the unit for seeing if strtold_l() exists
+ was created as U/threads/d_strtold_l.U, copied from perl/d_strtold.U, then
+ adjusted. It goes under 'threads' because it is used only on threaded
+ perls.
(d) Run "mlint -O" to see nits: as opposed to lint, the gripings of mlint
are usually serious and need fixing
which is apparently normal ...
--- the next steps are in the perl folder
-
-(e) chmod +w Configure config_h.SH
+-- the next steps are in the perl folder, though the instructions below include
+ a 'cd perl' at each step, as a reminder. If you already are in 'perl',
+ disregard the reminders.
- mlint and mconfig will probly die when these are read-only
+(e) There is a chicken and egg problem for newly created units. To get around
+ this, for such a unit, edit the file metaconfig.h and add to the comment
+ the appropropriate name. To continue the example above, we would add the
+ string HAS_STRTOLD_L at the end of the comment. This can be removed once
+ the code base has actual uses of the unit.
-(f) mconfig -m -O to regenerate Configure and config_h.SH
+(f) "mconfig -m -O" to regenerate Configure and config_h.SH
Make *sure* your mconfig is the correct one in your $PATH, as the mono-web
package will install /usr/bin/mconfig which will do something completely
reorganization is needed.
$ cd perl
- $ perl Porting/config_h.SH
+ $ perl Porting/config_h.pl
will fix the ordering
-
+
(h) The messy semi-automated part is that the knowledge of the new symbol
needs to be propagated to non-Configure lands like Win32, WinCE, Netware,
- VMS, VOS, EPOC, ... see previous Configure changes to see which are these
+ VMS, VOS, ... see previous Configure changes to see which are these
heathen lands. Files to take care of are
{win32,wince,NetWare}/config_[hH]*, (Win32, WinCE, NetWare),
- configure.com (VMS), epoc/config.sh (EPOC). Depending on the kind of
- patch djgpp/config* might also need adjusting (for example when
- adding/changing the list of extensions)
+ configure.com (VMS). Depending on the kind of patch djgpp/config* might
+ also need adjusting (for example when adding/changing the list of
+ extensions)
Most can be checked and updated by a tool Nicholas provided:
- $ cd perl
- $ perl Porting/Porting/checkcfgvar.pl
+ $ cd perl
+ $ perl Porting/checkcfgvar.pl
+
+ and if it shows differences, use one of:
+
+ $ perl Porting/checkcfgvar.pl --regen --default=undef
+ $ perl Porting/checkcfgvar.pl --regen --default=define
- and if it shows differences,
+ based on the changes you made. For safety, probes should probably be
+ 'undef', whereas some other things unconditionally should default to
+ 'define'. For example, 'default_inc_excludes_dot' should be 'define'
+ except in very limited circumstances, because it closes a security hole.
- $ perl Porting/checkcfgvar.pl --regen --default=define
+ For Win32 the process is semi-automated. You have to have a Win32
+ machine to run dmake on to complete the process, but that can be done
+ later by someone with such access.
- (of course "define" can also be "undef" based on the changes you made
+ For VMS, ('configure.com'), it may be best to add the units as 'undef' and
+ let the VMS experts deal with them later. However, you can set them to
+ 'define' if they are non-tricky (such as being basic functions having
+ standard signatures across architectures), and are in the oldest release of
+ VMS that perl can be compiled on, which is 7.3-2. Appendix A of "HP C
+ Run-Time Library Reference Manual for OpenVMS Systems" gives you that
+ information. As of October 2017, the latest version online is available
+ at: http://h41379.www4.hpe.com/doc/84final/5763/5763profile.html
- For Win32 the process is semi-automated - if you have a Win32
- machine to run dmake on ...
+ In configure.com, if there is an existing probe that is essentially the
+ same (except for the names) as the one you're adding, you can copy, paste,
+ and adjust to create a new one, but note that it's easy to run afoul of the
+ quoting rules in configure.com. New probed-for units likely will require
+ at least 2 groups of changes.
+
+ Rerun checkcfgvar.pl until you've fixed everything it finds.
(i) Check if U/mkglossary (right near the top) points to where you keep
dist's standard metaconfig units as well as your perl-specific ones.
(j) Run the perl build chain
$ cd perl
- $ make veryclean
+ $ make veryclean # Only if Configure already has been run
$ ./Configure -Duse64bitall -Dusethreads -Dusedevel -des
-
- The dependency for uconfig.h isn't carved in stone, so you might
- need to regenerate it
-
$ perl regen/uconfig_h.pl
Then make and make test or make test_harness
$ make -j12
$ env TEST_JOBS=13 make test_harness
- Before you start committing, make sure that the other developers
- are happy and run
+ Before you start committing, make sure that
$ make test_porting
- again
+ still passes
-(k) Run U/mksample to freshen the Porting/config* and Porting/Glossary.
+(k) Optionally, run Porting/mksample to freshen the Porting/config*.
Adjust the various compile-time options (e.g. 64bit, threads) as
you see fit.
- You can skip this phase, it's not essential, just good housekeeping.
+ You can skip this step, it's not essential, just good housekeeping.
Most of this only works if you have run the core-tests with the new
generated files
+(kk) Run U/mkgloss.pl to freshen Porting/Glossary
+
You should at least check
$ perl U/mkgloss.pl | diff Porting/Glossary -
-- the next steps are in the metaconfig folder again
-(l) git add U/perl/foo/bar.U when you are ready ...
+(l) git add U/foo/bar.U when you are ready ...
(m) git commit -m "Your commit description"
(n) When all patches are applied, tested and committed, and you are happy,
git push
+
+References:
+
+Documentation on 'dist' may be found at these locations:
+https://github.com/rmanfredi/dist/blob/master/mcon/man/mconfig.SH
+https://manpages.debian.org/stretch/dist/metaconfig.1.en.html
+
+Git tags:
+
+Tags are maintained in this git repository mapping the version of the
+units that were used for the Configure in a given release of perl,
+named simply after the version of perl in question (for example, at
+the time of writing the current stable release is 5.26.1). This provides
+a stable reference for downstreams wishing to import the metaconfig units
+into their own packaging. Therefore, at minimum tags for each stable
+release should be made (adding tags for development releases being an
+optional extra).
https://perl5.git.perl.org / metaconfig.git / blobdiff