dev-lang/perl: Add unkeyworded -r2 version with WIP features

This is a work in-progress experiment, hence, it is unkeyworded until
I can get more eyes on the changes, and fully test the consequences at
scale.

Important Changes:
- Convert to EAPI7
- Remove inherit on eutils
- Replace calls to "epatch" to "eapply", but resulting in a loss of
  nice output
- Add new hidden feature PERL_SINGLE_SLOT, which, when set, installs
  perl into a directory named after SUBSLOT (eg: 5.30) as opposed to one
  following the explicit name (eg: 5.30.2), which aims to pre-emptively
  solve (in both direction) the problem faced by shipping binpkg's,
  where the built perl has only one set of INC dirs (eg: 5.30.2), but a
  binpkg was built with a different, but compatible perl (eg: 5.30.1),
  and subsequently, installs to an @INC dir that is not visible to the
  built perl. Instead, all perl's that are defined to be
  inter-compatible share the same directory for both arch-dependent and
  arch-independent code, so binpkg's only need to be regenerated when:
  - Upgrading/downgrading between major revisions
  - Flipping USE="debug" or USE="ithreads".
  Under PERL_SINGLE_SLOT, directories that should be compatible, and are
  available, but built under the previous scheme, are also inhaled into
  @INC for ease of transition.
  The name of this flag is subject to change, and may become a USE flag.
- Add a new hidden feature PERL_SUPPORT_SINGLE_SLOT, which builds perl
  the same way as in previous versions, but also probes for version'd
  directories generated by installing packages on perl's built with
  PERL_SINGLE_SLOT, as a fallback mechaism for transitioning away from a
  perl built with PERL_SINGLE_SLOT.
  The name of this flag is subject to change, and may become a USE flag
- Add a patch to various parts of Configure, perl.c, and friends, to
  facilitate the above, which exposes itself as -Dgentoolibdirs=, and
  has the same syntax as -Dotherlibdirs, but doesn't pollute everything
  by adding its own arch-dirs when they weren't asked for. This patch
  may also later help facilitate building perl's without
  PERL_SINGLE_SLOT, but with other @INC dirs forced into place, for the
  same purpose, but implemented differently, as the previous mechanism,
  -Dinc_version_list is limited in that it:
    - Excludes internally directories that don't exist
    - Mangles directories sometimes trashing @INC entirely, throwing
      away litterally all the versions you passed.

- Fixed a very embarrasing typo in the einfo code, ${EROO%/T} ...
- Restructured the @INC discovery/cleanup logic into dedicated functions
- Add more error handling in the discovery path, especially adding loud
  error output if directories that *need* to be traversed for compat
  discovery cannot be traversed, due to misconfigured permissions.
- Fix an embarrasing bug in @INC list stripping, that due to inherently
  being a *substring* match, not a *fullstring* match, could have
  excluded 5.30.20 from the @INC path for 5.30.2, even though they're
  intercompatible. This became more obvious, when one was trying to
  strip '5.30' from a list that contained '5.30.1', '5.30.2', because it
  just ate everything!

Questions:
- Why do we have bzip2 in RDEPEND? Surely, that should be BDEPEND-only
- Are we even using bzip2 anymore?
- Should we migrate the patch ball to being a more-common-these-days set
  of numerically ordered patches, and potentially reduce the handling
  complexity in the ebuild as a result?

Package-Manager: Portage-2.3.100, Repoman-2.3.22
Signed-off-by: Kent Fredric <kentnl@gentoo.org>

1 files changed, 135 insertions, 0 deletions

diff --git a/dev-lang/perl/files/perl-5.30.3-gentoo-libdirs.patch b/dev-lang/perl/files/perl-5.30.3-gentoo-libdirs.patch
new file mode 100644
index 000000000000..b9e36223a941
--- /dev/null
+++ b/dev-lang/perl/files/perl-5.30.3-gentoo-libdirs.patch
@@ -0,0 +1,135 @@
+From 7572be1afb16621a537e9da02f96cf04cb10b655 Mon Sep 17 00:00:00 2001
+From: Kent Fredric <kentnl@gentoo.org>
+Date: Sat, 20 Jun 2020 22:14:22 +1200
+Subject: Add support for -Dgentoolibdirs
+
+Which just adds the libdirs verbatim in the right place without
+having perl molest it in the process.
+---
+ Configure        | 26 ++++++++++++++++++++++++++
+ config_h.SH      |  5 +++++
+ perl.c           |  1 +
+ perl_inc_macro.h |  8 ++++++++
+ uconfig.sh       |  1 +
+ 5 files changed, 41 insertions(+)
+
+diff --git a/Configure b/Configure
+index cef8c3c078..77258e8f43 100755
+--- a/Configure
++++ b/Configure
+@@ -1181,6 +1181,8 @@ orderlib=''
+ ranlib=''
+ d_perl_otherlibdirs=''
+ otherlibdirs=''
++gentoolibdirs=''
++d_gentoolibdirs=''
+ package=''
+ spackage=''
+ pager=''
+@@ -8101,6 +8103,28 @@ esac
+ set d_perl_otherlibdirs
+ eval $setvar
+ 
++case "$gentoolibdirs" in
++''|' ') dflt='none' ;;
++*) dflt="$gentoolibdirs" ;;
++esac
++$cat <<EOM
++Enter a colon-seperated list of explicit gentoo paths to stuff in @INC
++unmolested, or enter 'none' for no extra paths
++
++EOM
++rp='Colon-seperated list of gentoo-specific perl library search dirs?'
++. ./myread
++case "$ans" in
++' '|''|none) gentoolibdirs=' ';;
++*) gentoolibdirs="$ans" ;;
++esac
++case "$gentoolibdirs" in
++' ') val=$undef ;;
++*) val=$define ;;
++esac
++set d_gentoolibdirs
++eval $setvar
++
+ : DTrace support
+ dflt_dtrace='/usr/sbin/dtrace'
+ $test -x /usr/bin/dtrace && dflt_dtrace='/usr/bin/dtrace'
+@@ -24402,6 +24426,7 @@ d_openat='$d_openat'
+ d_pathconf='$d_pathconf'
+ d_pause='$d_pause'
+ d_perl_otherlibdirs='$d_perl_otherlibdirs'
++d_gentoolibdirs='$d_gentoolibdirs'
+ d_phostname='$d_phostname'
+ d_pipe2='$d_pipe2'
+ d_pipe='$d_pipe'
+@@ -24937,6 +24962,7 @@ orderlib='$orderlib'
+ osname='$osname'
+ osvers='$osvers'
+ otherlibdirs='$otherlibdirs'
++gentoolibdirs='$gentoolibdirs'
+ package='$package'
+ pager='$pager'
+ passcat='$passcat'
+diff --git a/config_h.SH b/config_h.SH
+index 08c5923ef8..5563082969 100755
+--- a/config_h.SH
++++ b/config_h.SH
+@@ -1308,6 +1308,11 @@ sed <<!GROK!THIS! >$CONFIG_H -e 's!^#undef\(.*/\)\*!/\*#define\1 \*!' -e 's!^#un
+  */
+ #$d_perl_otherlibdirs PERL_OTHERLIBDIRS "$otherlibdirs"		/**/
+ 
++/* GENTOO_LIBDIRS:
++ * Like PERL_OTHERLIBDIRS, but doesn't stuff ARCH dirs in when not wanted
++ */
++#$d_gentoolibdirs GENTOO_LIBDIRS "$gentoolibdirs"		/**/
++
+ /* PRIVLIB:
+  *	This symbol contains the name of the private library for this package.
+  *	The library is private in the sense that it needn't be in anyone's
+diff --git a/perl.c b/perl.c
+index 2013a76026..62e67cfaa2 100644
+--- a/perl.c
++++ b/perl.c
+@@ -4750,6 +4750,7 @@ S_init_perllib(pTHX)
+     INCPUSH_ARCHLIB_EXP
+     INCPUSH_PRIVLIB_EXP
+     INCPUSH_PERL_OTHERLIBDIRS
++    INCPUSH_GENTOO_LIBDIRS
+     INCPUSH_PERL5LIB
+     INCPUSH_APPLLIB_OLD_EXP
+     INCPUSH_SITELIB_STEM
+diff --git a/perl_inc_macro.h b/perl_inc_macro.h
+index 5a2f20dfae..4b69b39199 100644
+--- a/perl_inc_macro.h
++++ b/perl_inc_macro.h
+@@ -143,6 +143,14 @@
+ 		      INCPUSH_ADD_OLD_VERS|INCPUSH_CAN_RELOCATE);
+ #endif
+ 
++#ifdef GENTOO_LIBDIRS
++# define INCPUSH_GENTOO_LIBDIRS S_incpush_use_sep(aTHX_ STR_WITH_LEN(GENTOO_LIBDIRS), \
++    INCPUSH_ADD_OLD_VERS|INCPUSH_CAN_RELOCATE);
++#endif
++#ifndef INCPUSH_GENTOO_LIBDIRS
++# define INCPUSH_GENTOO_LIBDIRS
++#endif
++
+ #ifdef PERL_OTHERLIBDIRS
+ #	define INCPUSH_PERL_OTHERLIBDIRS_ARCHONLY  S_incpush_use_sep(aTHX_ STR_WITH_LEN(PERL_OTHERLIBDIRS), \
+ 		      INCPUSH_ADD_OLD_VERS|INCPUSH_ADD_ARCHONLY_SUB_DIRS|INCPUSH_CAN_RELOCATE);
+diff --git a/uconfig.sh b/uconfig.sh
+index 1d4a0f4a57..fba825acad 100644
+--- a/uconfig.sh
++++ b/uconfig.sh
+@@ -185,6 +185,7 @@ d_futimes='undef'
+ d_gai_strerror='undef'
+ d_gdbm_ndbm_h_uses_prototypes='undef'
+ d_gdbmndbm_h_uses_prototypes='undef'
++d_gentoolibdirs='undef'
+ d_getaddrinfo='undef'
+ d_getcwd='undef'
+ d_getespwnam='undef'
+-- 
+2.27.0
+