Merge from bittboy/buildroot@db180c0

docs/manual/adding-packages-perl.txt

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+// -*- mode:doc; -*-
+// vim: set syntax=asciidoc:
+
+=== Infrastructure for Perl/CPAN packages
+
+[[perl-package-tutorial]]
+
+==== +perl-package+ tutorial
+
+First, let's see how to write a +.mk+ file for a Perl/CPAN package,
+with an example :
+
+------------------------
+01: ################################################################################
+02: #
+03: # perl-foo-bar
+04: #
+05: ################################################################################
+06:
+07: PERL_FOO_BAR_VERSION = 0.02
+08: PERL_FOO_BAR_SOURCE = Foo-Bar-$(PERL_FOO_BAR_VERSION).tar.gz
+09: PERL_FOO_BAR_SITE = $(BR2_CPAN_MIRROR)/authors/id/M/MO/MONGER
+10: PERL_FOO_BAR_DEPENDENCIES = perl-strictures
+11: PERL_FOO_BAR_LICENSE = Artistic or GPL-1.0+
+12: PERL_FOO_BAR_LICENSE_FILES = LICENSE
+13: PERL_FOO_BAR_DISTNAME = Foo-Bar
+14:
+15: $(eval $(perl-package))
+------------------------
+
+On line 7, we declare the version of the package.
+
+On line 8 and 9, we declare the name of the tarball and the location
+of the tarball on a CPAN server. Buildroot will automatically download
+the tarball from this location.
+
+On line 10, we declare our dependencies, so that they are built
+before the build process of our package starts.
+
+On line 11 and 12, we give licensing details about the package (its
+license on line 11, and the file containing the license text on line
+12).
+
+On line 13, the name of the distribution as needed by the script
++utils/scancpan+ (in order to regenerate/upgrade these package files).
+
+Finally, on line 15, we invoke the +perl-package+ macro that
+generates all the Makefile rules that actually allow the package to be
+built.
+
+Most of these data can be retrieved from https://metacpan.org/.
+So, this file and the Config.in can be generated by running
+the script +utils/scancpan Foo-Bar+ in the Buildroot directory
+(or in a br2-external tree).
+This script creates a Config.in file and foo-bar.mk file for the
+requested package, and also recursively for all dependencies specified by
+CPAN. You should still manually edit the result. In particular, the
+following things should be checked.
+
+* If the perl module links with a shared library that is provided by
+  another (non-perl) package, this dependency is not added automatically.
+  It has to be added manually to +PERL_FOO_BAR_DEPENDENCIES+.
+* The +package/Config.in+ file has to be updated manually to include the
+  generated Config.in files. As a hint, the +scancpan+ script prints out
+  the required +source "..."+ statements, sorted alphabetically.
+
+[[perl-package-reference]]
+
+==== +perl-package+ reference
+
+As a policy, packages that provide Perl/CPAN modules should all be
+named +perl-<something>+ in Buildroot.
+
+This infrastructure handles various Perl build systems :
++ExtUtils-MakeMaker+ (EUMM), +Module-Build+ (MB) and +Module-Build-Tiny+.
++Build.PL+ is preferred by default when a package provides a +Makefile.PL+
+and a +Build.PL+.
+
+The main macro of the Perl/CPAN package infrastructure is
++perl-package+. It is similar to the +generic-package+ macro. The ability to
+have target and host packages is also available, with the
++host-perl-package+ macro.
+
+Just like the generic infrastructure, the Perl/CPAN infrastructure
+works by defining a number of variables before calling the
++perl-package+ macro.
+
+First, all the package metadata information variables that exist in the
+generic infrastructure also exist in the Perl/CPAN infrastructure:
++PERL_FOO_VERSION+, +PERL_FOO_SOURCE+,
++PERL_FOO_PATCH+, +PERL_FOO_SITE+,
++PERL_FOO_SUBDIR+, +PERL_FOO_DEPENDENCIES+,
++PERL_FOO_INSTALL_TARGET+.
+
+Note that setting +PERL_FOO_INSTALL_STAGING+ to +YES+ has no effect
+unless a +PERL_FOO_INSTALL_STAGING_CMDS+ variable is defined. The perl
+infrastructure doesn't define these commands since Perl modules generally
+don't need to be installed to the +staging+ directory.
+
+A few additional variables, specific to the Perl/CPAN infrastructure,
+can also be defined. Many of them are only useful in very specific
+cases, typical packages will therefore only use a few of them.
+
+* +PERL_FOO_PREFER_INSTALLER+/+HOST_PERL_FOO_PREFER_INSTALLER+,
+  specifies the preferred installation method. Possible values are
+  +EUMM+ (for +Makefile.PL+ based installation using
+  +ExtUtils-MakeMaker+) and +MB+ (for +Build.PL+ based installation
+  using +Module-Build+). This variable is only used when the package
+  provides both installation methods.
+
+* +PERL_FOO_CONF_ENV+/+HOST_PERL_FOO_CONF_ENV+, to specify additional
+  environment variables to pass to the +perl Makefile.PL+ or +perl Build.PL+.
+  By default, empty.
+
+* +PERL_FOO_CONF_OPTS+/+HOST_PERL_FOO_CONF_OPTS+, to specify additional
+  configure options to pass to the +perl Makefile.PL+ or +perl Build.PL+.
+  By default, empty.
+
+* +PERL_FOO_BUILD_OPTS+/+HOST_PERL_FOO_BUILD_OPTS+, to specify additional
+  options to pass to +make pure_all+ or +perl Build build+ in the build step.
+  By default, empty.
+
+* +PERL_FOO_INSTALL_TARGET_OPTS+, to specify additional options to
+  pass to +make pure_install+ or +perl Build install+ in the install step.
+  By default, empty.
+
+* +HOST_PERL_FOO_INSTALL_OPTS+, to specify additional options to
+  pass to +make pure_install+ or +perl Build install+ in the install step.
+  By default, empty.