=head1 DESCRIPTION
-This document describes the layout of the Perl source tree. If you're hacking
-on the Perl core, this will help you find what you're looking for.
+This document describes the layout of the Perl source tree. If you're
+hacking on the Perl core, this will help you find what you're looking
+for.
=head1 FINDING YOUR WAY AROUND
-The Perl source tree is big. Here's some of the thing you'll find in it:
+The Perl source tree is big. Here's some of the thing you'll find in
+it:
=head2 C code
-The C source code and header files mostly live in the root of the source
-tree. There are a few platform-specific directories which contain C code. In
-addition, some of the modules shipped with Perl include C or XS code.
+The C source code and header files mostly live in the root of the
+source tree. There are a few platform-specific directories which
+contain C code. In addition, some of the modules shipped with Perl
+include C or XS code.
See L<perlinterp> for more details on the files that make up the Perl
interpreter, as well as details on how it works.
=head2 Core modules
-Modules shipped as part of the Perl core live in four subdirectories. Two of
-these directories contain modules that live in the core, and two contain
-modules that can also be released separately on CPAN. Modules which can be
-released on cpan are known as "dual-life" modules.
+Modules shipped as part of the Perl core live in four subdirectories.
+Two of these directories contain modules that live in the core, and two
+contain modules that can also be released separately on CPAN. Modules
+which can be released on cpan are known as "dual-life" modules.
=over 4
=item * F<lib/>
-This directory contains pure-Perl modules which are only released as part of
-the core. This directory contains I<all> of the modules and their tests,
-unlike other core modules.
+This directory contains pure-Perl modules which are only released as
+part of the core. This directory contains I<all> of the modules and
+their tests, unlike other core modules.
=item * F<ext/>
-This directory contains XS-using modules which are only released as part of
-the core. These modules generally have their F<Makefile.PL> and are laid out
-more like a typical CPAN module.
+Like F<lib/>, this directory contains modules which are only released
+as part of the core. Unlike F<lib/>, however, a module under F<ext/>
+generally has a CPAN-style directory- and file-layout and its own
+F<Makefile.PL>. There is no expectation that a module under F<ext/>
+will work with earlier versions of Perl 5. Hence, such a module may
+take full advantage of syntactical and other improvements in Perl 5
+blead.
=item * F<dist/>
This directory is for dual-life modules where the blead source is
-canonical. Note that some modules in this directory may not yet have been
-released separately on CPAN.
+canonical. Note that some modules in this directory may not yet have
+been released separately on CPAN. Modules under F<dist/> should make
+an effort to work with earlier versions of Perl 5.
=item * F<cpan/>
This directory contains dual-life modules where the CPAN module is
-canonical. Do not patch these modules directly! Changes to these modules
-should be submitted to the maintainer of the CPAN module. Once those changes
-are applied and released, the new version of the module will be incorporated
-into the core.
+canonical. Do not patch these modules directly! Changes to these
+modules should be submitted to the maintainer of the CPAN module. Once
+those changes are applied and released, the new version of the module
+will be incorporated into the core.
=back
-For some dual-life modules, it has not yet been determined if the CPAN version
-or the blead source is canonical. Until that is done, those modules should be
-in F<cpan/>.
+For some dual-life modules, it has not yet been determined if the CPAN
+version or the blead source is canonical. Until that is done, those
+modules should be in F<cpan/>.
=head2 Tests
The Perl core has an extensive test suite. If you add new tests (or new
-modules with tests), you may need to update the F<t/TEST> file so that the
-tests are run.
+modules with tests), you may need to update the F<t/TEST> file so that
+the tests are run.
=over 4
=item * Module tests
-Tests for core modules in the F<lib/> directory are right next to the module
-itself. For example, we have F<lib/strict.pm> and F<lib/strict.t>.
+Tests for core modules in the F<lib/> directory are right next to the
+module itself. For example, we have F<lib/strict.pm> and
+F<lib/strict.t>.
Tests for modules in F<ext/> and the dual-life modules are in F<t/>
subdirectories for each module, like a standard CPAN distribution.
=item * F<t/base/>
-Tests for the absolute basic functionality of Perl. This includes C<if>, basic
-file reads and writes, simple regexes, etc. These are run first in the test
-suite and if any of them fail, something is I<really> broken.
+Tests for the absolute basic functionality of Perl. This includes
+C<if>, basic file reads and writes, simple regexes, etc. These are run
+first in the test suite and if any of them fail, something is I<really>
+broken.
=item * F<t/cmd/>
-Tests for basic control structures, C<if/else>, C<while>,
-subroutines, etc.
+Tests for basic control structures, C<if>/C<else>, C<while>, subroutines,
+etc.
=item * F<t/comp/>
Tests for perl's built in functions that don't fit into any of the
other directories.
+=item * F<t/opbasic/>
+
+Tests for perl's built in functions which, like those in F<t/op/>, do
+not fit into any of the other directories, but which, in addition,
+cannot use F<t/test.pl>,as that program depends on functionality which
+the test file itself is testing.
+
=item * F<t/re/>
Tests for regex related functions or behaviour. (These used to live in
=item * F<t/porting/>
-Tests the state of the source tree for various common errors. For example, it
-tests that everyone who is listed in the git log has a corresponding entry in
-the F<AUTHORS> file.
+Tests the state of the source tree for various common errors. For
+example, it tests that everyone who is listed in the git log has a
+
corresponding entry in the F<AUTHORS> file.
=item * F<t/lib/>
here. There are still some bits and pieces hanging around in here that
need to be moved. Perhaps you could move them? Thanks!
-=item * F<t/x2p>
-
-A test suite for the s2p converter.
-
=back
=head2 Documentation
-All of the core documentation intended for end users lives in
-F<pod/>. Individual modules in F<lib/>, F<ext/>, F<dist/>, and F<cpan/>
-usually have their own documentation, either in the F<Module.pm> file or an
+All of the core documentation intended for end users lives in F<pod/>.
+Individual modules in F<lib/>, F<ext/>, F<dist/>, and F<cpan/> usually
+have their own documentation, either in the F<Module.pm> file or an
accompanying F<Module.pod> file.
Finally, documentation intended for core Perl developers lives in the
=item * F<check*>
-These are scripts which will check the source things like ANSI C violations,
-POD encoding issues, etc.
+These are scripts which will check the source things like ANSI C
+violations, POD encoding issues, etc.
=item * F<Maintainers>, F<Maintainers.pl>, and F<Maintainers.pm>
-These files contain information on who maintains which modules. Run C<perl
-Porting/Maintainers -M Module::Name> to find out more information about a
-dual-life module.
+These files contain information on who maintains which modules. Run
+C<perl Porting/Maintainers -M Module::Name> to find out more
+information about a dual-life module.
=item * F<podtidy>
-Tidies a pod file. It's a good idea to run this on a pod file you've patched.
+Tidies a pod file. It's a good idea to run this on a pod file you've
+patched.
=back
=head2 Build system
-The Perl build system starts with the F<Configure> script in the root
-directory.
+The Perl build system on *nix-like systems starts with the F<Configure>
+script in the root directory.
-Platform-specific pieces of the build system also live in platform-specific
-directories like F<win32/>, F<vms/>, etc.
+Platform-specific pieces of the build system also live in
+platform-specific directories like F<win32/>, F<vms/>, etc.
+Windows and VMS have their own Configure-like scripts, in their
+respective directories.
-The F<Configure> script is ultimately responsible for generating a
-F<Makefile>.
+The F<Configure> script (or a platform-specific similar script) is
+ultimately responsible for generating a F<Makefile> from F<Makefile.SH>.
The build system that Perl uses is called metaconfig. This system is
-maintained separately from the Perl core.
+maintained separately from the Perl core, and knows about the
+platform-specific Configure-like scripts, as well as F<Configure>
+itself.
-The metaconfig system has its own git repository. Please see its README file
-in L<http://perl5.git.perl.org/metaconfig.git/> for more details.
+The metaconfig system has its own git repository. Please see its README
+file in L<https://github.com/Perl/metaconfig> for more details.
-The F<Cross> directory contains various files related to cross-compiling
-Perl. See F<Cross/README> for more details.
+The F<Cross> directory contains various files related to
+cross-compiling Perl. See F<Cross/README> for more details.
=head2 F<AUTHORS>
-This file lists everyone who's contributed to Perl. If you submit a patch, you
-should add your name to this file as part of the patch.
+This file lists everyone who's contributed to Perl. If you submit a
+patch, you should add your name to this file as part of the patch.
=head2 F<MANIFEST>
-The F<MANIFEST> file in the root of the source tree contains a list of every
-file in the Perl core, as well as a brief description of each file.
+The F<MANIFEST> file in the root of the source tree contains a list of
+every file in the Perl core, as well as a brief description of each
+file.
You can get an overview of all the files with this command:
https://perl5.git.perl.org / perl5.git / blobdiff