+=item *
+
+IO-Compress has been upgraded from version 2.069 to 2.074.
+
+=item *
+
+L<IO::Socket::IP> has been upgraded from version 0.37 to 0.38.
+
+=item *
+
+L<IPC::Cmd> has been upgraded from version 0.92 to 0.96.
+
+=item *
+
+L<IPC::SysV> has been upgraded from version 2.06_01 to 2.07.
+
+=item *
+
+L<JSON::PP> has been upgraded from version 2.27300 to 2.27400_02.
+
+=item *
+
+L<lib> has been upgraded from version 0.63 to 0.64.
+
+It now uses 3-arg C<open()> instead of 2-arg C<open()>. [perl #130122]
+
+=item *
+
+L<List::Util> has been upgraded from version 1.42_02 to 1.46_02.
+
+=item *
+
+L<Locale::Codes> has been upgraded from version 3.37 to 3.42.
+
+=item *
+
+L<Locale::Maketext> has been upgraded from version 1.26 to 1.28.
+
+=item *
+
+L<Locale::Maketext::Simple> has been upgraded from version 0.21 to 0.21_01.
+
+=item *
+
+L<Math::BigInt> has been upgraded from version 1.999715 to 1.999806.
+
+There have also been some core customizations.
+
+=item *
+
+L<Math::BigInt::FastCalc> has been upgraded from version 0.40 to 0.5005.
+
+=item *
+
+L<Math::BigRat> has been upgraded from version 0.260802 to 0.2611.
+
+=item *
+
+L<Math::Complex> has been upgraded from version 1.59 to 1.5901.
+
+=item *
+
+L<Memoize> has been upgraded from version 1.03 to 1.03_01.
+
+=item *
+
+L<Module::CoreList> has been upgraded from version 5.20170420 to 5.20170520.
+
+=item *
+
+L<Module::Load::Conditional> has been upgraded from version 0.64 to 0.68.
+
+=item *
+
+L<Module::Metadata> has been upgraded from version 1.000031 to 1.000033.
+
+=item *
+
+L<mro> has been upgraded from version 1.18 to 1.20.
+
+=item *
+
+L<Net::Ping> has been upgraded from version 2.43 to 2.55.
+
+IPv6 addresses and C<AF_INET6> sockets are now supported, along with several
+other enhancements.
+
+Remove sudo from 500_ping_icmp.t.
+
+Avoid stderr noise in tests
+
+Check for echo in new Net::Ping tests.
+
+=item *
+
+L<NEXT> has been upgraded from version 0.65 to 0.67.
+
+=item *
+
+L<Opcode> has been upgraded from version 1.34 to 1.39.
+
+=item *
+
+L<open> has been upgraded from version 1.10 to 1.11.
+
+=item *
+
+L<OS2::Process> has been upgraded from version 1.11 to 1.12.
+
+It now uses 3-arg C<open()> instead of 2-arg C<open()>. [perl #130122]
+
+=item *
+
+L<overload> has been upgraded from version 1.26 to 1.28.
+
+Its compilation speed has been improved slightly.
+
+=item *
+
+L<parent> has been upgraded from version 0.234 to 0.236.
+
+=item *
+
+L<perl5db.pl> has been upgraded from version 1.50 to 1.51.
+
+Ignore F</dev/tty> on non-Unix systems. [perl #113960]
+
+=item *
+
+L<Perl::OSType> has been upgraded from version 1.009 to 1.010.
+
+=item *
+
+L<perlfaq> has been upgraded from version 5.021010 to 5.021011.
+
+=item *
+
+L<PerlIO> has been upgraded from version 1.09 to 1.10.
+
+=item *
+
+L<PerlIO::encoding> has been upgraded from version 0.24 to 0.25.
+
+=item *
+
+L<PerlIO::scalar> has been upgraded from version 0.24 to 0.26.
+
+=item *
+
+L<Pod::Checker> has been upgraded from version 1.60 to 1.73.
+
+=item *
+
+L<Pod::Functions> has been upgraded from version 1.10 to 1.11.
+
+=item *
+
+L<Pod::Html> has been upgraded from version 1.22 to 1.2202.
+
+=item *
+
+L<Pod::Perldoc> has been upgraded from version 3.25_02 to 3.28.
+
+=item *
+
+L<Pod::Simple> has been upgraded from version 3.32 to 3.35.
+
+=item *
+
+L<Pod::Usage> has been upgraded from version 1.68 to 1.69.
+
+=item *
+
+L<POSIX> has been upgraded from version 1.65 to 1.76. This remedies several
+defects in making its symbols exportable. [perl #127821]
+The C<POSIX::tmpnam()> interface has been removed,
+see L</"POSIX::tmpnam() has been removed">.
+Trying to import POSIX subs that have no real implementations
+(like C<POSIX::atend()>) now fails at import time, instead of
+waiting until runtime.
+
+=item *
+
+L<re> has been upgraded from version 0.32 to 0.34
+
+This adds support for the new L<C<E<47>xx>|perlre/E<sol>x and E<sol>xx>
+regular expression pattern modifier, and a change to the L<S<C<use re
+'strict'>>|re/'strict' mode> experimental feature. When S<C<re
+'strict'>> is enabled, a warning now will be generated for all
+unescaped uses of the two characters C<}> and C<]> in regular
+expression patterns (outside bracketed character classes) that are taken
+literally. This brings them more in line with the C<)> character which
+is always a metacharacter unless escaped. Being a metacharacter only
+sometimes, depending on action at a distance, can lead to silently
+having the pattern mean something quite different than was intended,
+which the S<C<re 'strict'>> mode is intended to minimize.
+
+=item *
+
+L<Safe> has been upgraded from version 2.39 to 2.40.
+
+=item *
+
+L<Scalar::Util> has been upgraded from version 1.42_02 to 1.46_02.
+
+=item *
+
+L<Storable> has been upgraded from version 2.56 to 2.62.
+
+Fixes [perl #130098].
+
+=item *
+
+L<Symbol> has been upgraded from version 1.07 to 1.08.
+
+=item *
+
+L<Sys::Syslog> has been upgraded from version 0.33 to 0.35.
+
+=item *
+
+L<Term::ANSIColor> has been upgraded from version 4.04 to 4.06.
+
+=item *
+
+L<Term::ReadLine> has been upgraded from version 1.15 to 1.16.
+
+It now uses 3-arg C<open()> instead of 2-arg C<open()>. [perl #130122]
+
+=item *
+
+L<Test> has been upgraded from version 1.28 to 1.30.
+
+It now uses 3-arg C<open()> instead of 2-arg C<open()>. [perl #130122]
+
+=item *
+
+L<Test::Harness> has been upgraded from version 3.36 to 3.38.
+
+=item *
+
+L<Test::Simple> has been upgraded from version 1.001014 to 1.302073.
+
+=item *
+
+L<Thread::Queue> has been upgraded from version 3.09 to 3.12.
+
+=item *
+
+L<Thread::Semaphore> has been upgraded from 2.12 to 2.13.
+
+Added the C<down_timed> method.
+
+=item *
+
+L<threads> has been upgraded from version 2.07 to 2.15.
+
+Compatibility with 5.8 has been restored.
+
+Fixes [perl #130469].
+
+=item *
+
+L<threads::shared> has been upgraded from version 1.51 to 1.56.
+
+This fixes [cpan #119529], [perl #130457]
+
+=item *
+
+L<Tie::Hash::NamedCapture> has been upgraded from version 0.09 to 0.10.
+
+=item *
+
+L<Time::HiRes> has been upgraded from version 1.9733 to 1.9741.
+
+It now builds on systems with C++11 compilers (such as G++ 6 and Clang++
+3.9).
+
+Now uses C<clockid_t>.
+
+=item *
+
+L<Time::Local> has been upgraded from version 1.2300 to 1.25.
+
+=item *
+
+L<Unicode::Collate> has been upgraded from version 1.14 to 1.19.
+
+=item *
+
+L<Unicode::UCD> has been upgraded from version 0.64 to 0.68.
+
+It now uses 3-arg C<open()> instead of 2-arg C<open()>. [perl #130122]
+
+=item *
+
+L<version> has been upgraded from version 0.9916 to 0.9917.
+
+=item *
+
+L<VMS::DCLsym> has been upgraded from version 1.06 to 1.08.
+
+It now uses 3-arg C<open()> instead of 2-arg C<open()>. [perl #130122]
+
+=item *
+
+L<warnings> has been upgraded from version 1.36 to 1.37.
+
+=item *
+
+L<XS::Typemap> has been upgraded from version 0.14 to 0.15.
+
+=item *
+
+L<XSLoader> has been upgraded from version 0.21 to 0.27.
+
+Fixed a security hole in which binary files could be loaded from a path
+outside of L<C<@INC>|perlvar/@INC>.
+
+It now uses 3-arg C<open()> instead of 2-arg C<open()>. [perl #130122]
+
+=back
+
+=head1 Documentation
+
+=head2 New Documentation
+
+=head3 L<perldeprecation>
+
+This file documents all upcoming deprecations, and some of the deprecations
+which already have been removed. The purpose of this documentation is
+two-fold: document what will disappear, and by which version, and serve
+as a guide for people dealing with code which has features that no longer
+work after an upgrade of their perl.
+
+=head2 Changes to Existing Documentation
+
+=head3 L<perlcall>
+
+=over 4
+
+=item *
+
+Use of unassigned code point or non-standalone grapheme for a delimiter will be a fatal error starting in Perl 5.30
+
+This was changed to drop a leading C<v> in C<v5.30>, so it uses the same
+style as other deprecation messages.
+
+=item *
+
+"\c%c" is more clearly written simply as "%s".
+
+It was decided to undeprecate the use of C<\c%c>, see L<http://www.nntp.perl.org/group/perl.perl5.porters/2017/02/msg242944.html>
+
+=item *
+
+Removed redundant C<dSP> from an example.
+
+=back
+
+=head3 L<perlcommunity>
+
+=over 4
+
+=item *
+
+All references to Usenet have been removed.
+
+=back
+
+=head3 L<perldata>
+
+=over 4
+
+=item *
+
+Updated documentation of C<scalar(%hash)>. See L</scalar(%hash) return
+signature changed> above.
+
+=item *
+
+Use of single character variables, with the variable name a non printable
+character in the range C<\x80>-C<\xFF> is no longer allowed. Update the docs to
+reflect this.
+
+=back
+
+=head3 L<perldelta>
+
+=over 4
+
+=item *
+
+All references to Usenet have been removed.
+
+=back
+
+=head3 L<perldiag>
+
+=over 4
+
+=item *
+
+Deprecations are to be marked with a D.
+C<"%s() is deprecated on :utf8 handles"> use a deprecation message, and as
+such, such be marked C<"(D deprecated)"> and not C<"(W deprecated)">.
+
+=back
+
+=head3 L<perlexperiment>
+
+=over 4
+
+=item *
+
+Documented new feature: See L</Declaring a reference to a variable> above.
+
+=back
+
+=head3 L<perlfunc>
+
+=over 4
+
+=item *
+
+Defined on aggregates is no longer allowed. Perlfunc was still reporting it as
+deprecated, and that it will be deleted in the future.
+
+=item *
+
+Clarified documentation of L<C<seek()>|perlfunc/seek>,
+L<C<tell()>|perlfunc/tell> and L<C<sysseek()>|perlfunc/sysseek>.
+L<[perl #128607]|https://rt.perl.org/Public/Bug/Display.html?id=128607>
+
+=item *
+
+Removed obsolete documentation of L<C<study()>|perlfunc/study>.
+
+=back
+
+=head3 L<perlguts>
+
+=over 4
+
+=item *
+
+Add C<pTHX_> to magic method examples.
+
+=back
+
+=head3 L<perlhack>
+
+=over 4
+
+=item *
+
+Document Tab VS Space.
+
+=back
+
+=head3 L<perlinterp>
+
+=over 4
+
+=item *
+
+L<perlinterp> has been expanded to give a more detailed example of how to
+hunt around in the parser for how a given operator is handled.
+
+=back
+
+=head3 L<perllocale>
+
+=over 4
+
+=item *
+
+Document C<NUL> collation handling.
+
+=item *
+
+Some locales aren't compatible with Perl. Note the potential bad
+consequences of using them.
+
+=back
+
+=head3 L<perlmodinstall>
+
+=over 4
+
+=item *
+
+All references to Usenet have been removed.
+
+=back
+
+=head3 L<perlmodlib>
+
+=over 4
+
+=item *
+
+Updated the mirror list.
+
+=item *
+
+All references to Usenet have been removed.
+
+=back
+
+=head3 L<perlnewmod>
+
+=over 4
+
+=item *
+
+All references to Usenet have been removed.
+
+=back
+
+=head3 L<perlobj>
+
+=over 4
+
+=item *
+
+Added a section on calling methods using their fully qualified names.
+
+=item *
+
+Do not discourage manual @ISA.
+
+=back
+
+=head3 L<perlootut>
+
+=over 4
+
+=item *
+
+Tidy the document.
+
+=item *
+
+Mention C<Moo> more.
+
+=back
+
+=head3 L<perlop>
+
+=over 4
+
+=item *
+
+Clarify behavior single quote regexps.
+
+=back
+
+=head3 L<perlre>
+
+=over 4
+
+=item *
+
+Several minor enhancements to the documentation.
+
+=back
+
+=head3 L<perlsec>
+
+=over 4
+
+=item *
+
+Fixed link to Crosby paper on hash complexity attack.
+
+=back
+
+=head3 L<perlref>
+
+=over 4
+
+=item *
+
+Documented new feature: See L</Declaring a reference to a variable> above.
+
+=back
+
+=head3 L<perltie>
+
+=over 4
+
+=item *
+
+Updated documentation of C<scalar(%hash)>. See L</scalar(%hash) return
+signature changed> above.
+
+=back
+
+=head3 L<perlunicode>
+
+=over 4
+
+=item *
+
+Documented change to C<\p{I<script>}> to now use the improved Script_Extensions
+property. See L</Use of \p{script} uses the improved Script_Extensions
+property> above.
+
+=item *
+
+Updated the text to correspond with changes in Unicode UTS#18, concerning
+regular expressions, and Perl compatibility with what it says.
+
+=back
+
+=head3 L<perlvar>
+
+=over 4
+
+=item *
+
+Removed obsolete documentation of C<${^ENCODING}>. See L</${^ENCODING} has
+been removed> above.
+
+=item *
+
+Document C<@ISA>. Was documented other places, not not in L<perlvar>.
+
+=back
+
+=head1 Diagnostics
+
+=head2 New Diagnostics
+
+=head3 New Errors
+
+=over 4
+
+=item *
+
+Since C<.> is now removed from C<@INC> by default, C<do> will now trigger
+a warning recommending to fix the C<do> statement:
+
+L<do "%s" failed, '.' is no longer in @INC|perldiag/do "%s" failed, '.' is no longer in @INC; did you mean do ".E<sol>%s"?>
+
+=item *
+
+Using the empty pattern (which re-executes the last successfully-matched
+pattern) inside a code block in another regex, as in C</(?{ s!!new! })/>, has
+always previously yielded a segfault. It now produces an error:
+L<Infinite recursion in regex|perldiag/"Infinite recursion in regex">.
+
+=item *
+
+L<The experimental declared_refs feature is not enabled|perldiag/"The experimental declared_refs feature is not enabled">
+
+(F) To declare references to variables, as in C<my \%x>, you must first enable
+the feature:
+
+ no warnings "experimental::declared_refs";
+ use feature "declared_refs";
+
+=item *
+
+L<Version control conflict marker|perldiag/"Version control conflict marker">
+
+(F) The parser found a line starting with C<E<lt>E<lt>E<lt>E<lt>E<lt>E<lt>E<lt>>,
+C<E<gt>E<gt>E<gt>E<gt>E<gt>E<gt>E<gt>>, or C<=======>. These may be left by a
+version control system to mark conflicts after a failed merge operation.
+
+=item *
+
+L<%s: command not found|perldiag/"%s: command not found">
+
+(A) You've accidentally run your script through B<bash> or another shell
+instead of Perl. Check the #! line, or manually feed your script into
+Perl yourself. The #! line at the top of your file could look like:
+
+ #!/usr/bin/perl
+
+=item *
+
+L<%s: command not found: %s|perldiag/"%s: command not found: %s">
+
+(A) You've accidentally run your script through B<zsh> or another shell
+instead of Perl. Check the #! line, or manually feed your script into
+Perl yourself. The #! line at the top of your file could look like:
+
+ #!/usr/bin/perl
+
+=item *
+
+L<Unescaped left brace in regex is deprecated here (and will be fatal in Perl 5.30), passed through in regex; marked by S<E<lt>-- HERE> in mE<sol>%sE<sol>|perldiag/"Unescaped left brace in regex is deprecated here (and will be fatal in Perl 5.30), passed through in regex; marked by S<<-- HERE> in m/%s/">
+
+Unescaped left braces are already illegal in some contexts in regular
+expression patterns, but, due to an oversight, no deprecation warning
+was raised in other contexts where they are intended to become illegal.
+This warning is now raised in these contexts.
+
+=item *
+
+L<Bareword in require contains "%s"|perldiag/"Bareword in require contains "%s"">
+
+=item *
+
+L<Bareword in require maps to empty filename|perldiag/"Bareword in require maps to empty filename">
+
+=item *
+
+L<Bareword in require maps to disallowed filename "%s"|perldiag/"Bareword in require maps to disallowed filename "%s"">
+
+=item *
+
+L<Bareword in require must not start with a double-colon: "%s"|perldiag/"Bareword in require must not start with a double-colon: "%s"">
+
+=back
+
+=head3 New Warnings
+
+=over 4
+
+=item *
+
+L<Use of unassigned code point or non-standalone grapheme for a delimiter will be a fatal error starting in Perl 5.30|perldiag/"Use of unassigned code point or non-standalone grapheme for a delimiter will be a fatal error starting in Perl 5.30">
+
+See L</Deprecations>
+
+=item *
+
+L<Declaring references is experimental|perldiag/"Declaring references is experimental">
+
+(S experimental::declared_refs) This warning is emitted if you use a reference
+constructor on the right-hand side of C<my()>, C<state()>, C<our()>, or
+C<local()>. Simply suppress the warning if you want to use the feature, but
+know that in doing so you are taking the risk of using an experimental feature
+which may change or be removed in a future Perl version:
+
+ no warnings "experimental::declared_refs";
+ use feature "declared_refs";
+ $fooref = my \$foo;
+
+=item *
+
+L<C<${^ENCODING}> is no longer supported. Its use will be fatal in Perl 5.28|perldiag/"${^ENCODING} is no longer supported. Its use will be fatal in Perl 5.28">
+
+(D deprecated) The special variable C<${^ENCODING}>, formerly used to implement
+the C<encoding> pragma, is no longer supported as of Perl 5.26.0.
+
+=item *
+
+Since C<.> is now removed from C<@INC> by default, C<do> will now trigger
+a warning recommending to fix the C<do> statement:
+
+L<do "%s" failed, '.' is no longer in @INC|perldiag/do "%s" failed, '.' is no
+longer in @INC; did you mean do ".\/%s"?>
+
+=back
+
+=head2 Changes to Existing Diagnostics
+
+=over 4
+
+=item *
+
+When a C<require> fails, we now do not provide C<@INC> when the C<require>
+is for a file instead of a module.
+
+=item *
+
+When C<@INC> is not scanned for a C<require> call, we no longer display
+C<@INC> to avoid confusion.
+
+=item *
+
+Attribute "locked" is deprecated, and will disappear in Perl 5.28
+
+=item *
+
+Attribute "unique" is deprecated, and will disappear in Perl 5.28
+
+=item *
+
+Constants from lexical variables potentially modified elsewhere are
+deprecated. This will not be allowed in Perl 5.32
+
+=item *
+
+Deprecated use of my() in false conditional. This will be a fatal error
+in Perl 5.30
+
+=item *
+
+dump() better written as CORE::dump(). dump() will no longer be available
+in Perl 5.30
+
+=item *
+
+${^ENCODING} is no longer supported. Its use will be fatal in Perl 5.28
+
+=item *
+
+File::Glob::glob() will disappear in perl 5.30. Use File::Glob::bsd_glob()
+instead.
+
+=item *
+
+%s() is deprecated on :utf8 handles. This will be a fatal error in Perl 5.30
+
+=item *
+
+$* is no longer supported. Its use will be fatal in Perl 5.30
+
+=item *
+
+$* is no longer supported. Its use will be fatal in Perl 5.30
+
+=item *
+
+Opening dirhandle %s also as a file. This will be a fatal error in Perl 5.28
+
+=item *
+
+Opening filehandle %s also as a directory. This will be a fatal
+error in Perl 5.28
+
+=item *
+
+Setting $/ to a reference to %s as a form of slurp is deprecated,
+treating as undef. This will be fatal in Perl 5.28
+
+=item *
+
+Unescaped left brace in regex is deprecated here (and will be fatal
+in Perl 5.30), passed through in regex; marked by S<< E<lt>-- HERE >> in m/%s/
+
+=item *
+
+Unknown charname '' is deprecated. Its use will be fatal in Perl 5.28
+
+=item *
+
+Use of bare E<lt>E<lt> to mean E<lt>E<lt>"" is deprecated. Its use will be fatal in Perl 5.28
+
+=item *
+
+Use of code point 0x%s is deprecated; the permissible max is 0x%s.
+This will be fatal in Perl 5.28
+
+=item *
+
+Use of comma-less variable list is deprecated. Its use will be fatal
+in Perl 5.28
+
+=item *
+
+Use of inherited AUTOLOAD for non-method %s() is deprecated. This
+will be fatal in Perl 5.28
+
+=item *
+
+Use of strings with code points over 0xFF as arguments to %s operator
+is deprecated. This will be a fatal error in Perl 5.28
+
+=item *
+
+Improve error for missing tie() package/method. This brings the error messages
+in line with the ones used for normal method calls, despite not using
+call_method().
+
+=item *
+
+Make the sysread()/syswrite/() etc :utf8 handle warnings default. These
+warnings were under 'deprecated' previously.
+
+=item *
+
+'do' errors now refer to 'do' (not 'require').
+
+=item *
+
+Details as to the exact problem have been added to the diagnostics that
+occur when malformed UTF-8 is encountered when trying to convert to a
+code point.
+
+=item *
+
+Executing C<undef $x> where C<$x> is tied or magical no longer incorrectly
+blames the variable for an uninitialized-value warning encountered by the
+tied/magical code.
+
+=item *
+
+L<Unescaped left brace in regex is illegal here in regex; marked by S<E<lt>-- HERE> in mE<sol>%sE<sol>|perldiag/"Unescaped left brace in regex is illegal here in regex; marked by S<<-- HERE> in m/%s/">
+
+The word "here" has been added to the message that was raised in
+v5.25.1. This is to indicate that there are contexts in which unescaped
+left braces are not (yet) illegal.
+
+=item *
+
+Code like C<$x = $x . "a"> was incorrectly failing to yield a
+L<use of uninitialized value|perldiag/"Use of uninitialized value%s">
+warning when C<$x> was a lexical variable with an undefined value. That has
+now been fixed. [perl #127877]
+
+=item *
+
+When the error "Experimental push on scalar is now forbidden" is raised for
+the hash functions C<keys>, C<each>, and C<values>, it is now followed by
+the more helpful message, "Type of arg 1 to whatever must be hash or
+array". [perl #127976]
+
+=item *
+
+C<undef *_; shift> or C<undef *_; pop> inside a subroutine, with no
+argument to C<shift> or C<pop>, began crashing in Perl 5.14.0, but has now
+been fixed.
+
+=item *
+
+C<< "string$scalar-E<gt>$*" >> now correctly prefers concat overloading to
+string overloading if C<< $scalar-E<gt>$* >> returns an overloaded object,
+bringing it into consistency with C<$$scalar>.
+
+=item *
+
+C<< /@0{0*-E<gt>@*/*0 >> and similar contortions used to crash, but no longer
+do, but merely produce a syntax error. [perl #128171]
+
+=item *
+
+C<do> or C<require> with a reference or typeglob which, when stringified,
+contains a null character started crashing in Perl 5.20.0, but has now been
+fixed. [perl #128182]
+
+=back
+
+=head1 Utility Changes
+
+=head2 F<c2ph> and F<pstruct>
+
+=over 4
+
+=item *
+
+These old utilities have long since superceded by L<h2xs>, and are
+now gone from the distribution.
+
+=back
+
+=head2 F<Porting/pod_lib.pl>
+
+=over 4
+
+=item *
+
+Removed spurious executable bit.
+
+=item *
+
+Account for possibility of DOS file endings.
+
+=back
+
+=head2 F<Porting/sync-with-cpan>
+
+=over 4
+
+=item *
+
+Many improvements
+
+=back
+
+=head2 F<perf/benchmarks>
+
+=over 4
+
+=item *
+
+Tidy file, rename some symbols.
+
+=back
+
+=head2 F<Porting/checkAUTHORS.pl>
+
+=over 4
+
+=item *
+
+Replace obscure character range with \w.
+
+=back
+
+=head2 F<t/porting/regen.t>
+
+=over 4
+
+=item *
+
+try to be more helpful when tests fail.
+
+=back
+
+=head2 F<utils/h2xs.PL>
+
+=over 4
+
+=item *
+
+Avoid infinite loop for enums.
+
+=back
+
+=head2 L<perlbug>
+
+=over 4
+
+=item *
+
+Long lines in the message body are now wrapped at 900 characters, to stay
+well within the 1000-character limit imposed by SMTP mail transfer agents.
+This is particularly likely to be important for the list of arguments to
+C<Configure>, which can readily exceed the limit if, for example, it names
+several non-default installation paths. This change also adds the first unit
+tests for perlbug. [perl #128020]
+
+=back
+
+=head1 Configuration and Compilation
+
+=over 4
+
+=item *
+
+C<-Ddefault_inc_excludes_dot> has been turned on by default.
+
+=item *
+
+The C<dtrace> build process has further changes:
+
+=over
+
+=item *
+
+If the C<-xnolibs> is available, use that so a F<dtrace> perl can be
+built within a FreeBSD jail.
+
+=item *
+
+On systems that build a dtrace object file (FreeBSD, Solaris and
+SystemTap's dtrace emulation), copy the input objects to a separate
+directory and process them there, and use those objects in the link,
+since C<dtrace -G> also modifies these objects.
+
+=item *
+
+Add libelf to the build on FreeBSD 10.x, since dtrace adds references
+to libelf symbols.
+
+=item *
+
+Generate a dummy dtrace_main.o if C<dtrace -G> fails to build it. A
+default build on Solaris generates probes from the unused inline
+functions, while they don't on FreeBSD, which causes C<dtrace -G> to
+fail.
+
+=back
+
+[perl #130108]
+
+=item *
+
+You can now disable perl's use of the PERL_HASH_SEED and
+PERL_PERTURB_KEYS environment variables by configuring perl with
+C<-Accflags=NO_PERL_HASH_ENV>.
+
+=item *
+
+You can now disable perl's use of the PERL_HASH_SEED_DEBUG environment
+variable by configuring perl with
+C<-Accflags=-DNO_PERL_HASH_SEED_DEBUG>.
+
+=item *
+
+Zero out the alignment bytes when calculating the bytes for 80-bit C<NaN>
+and C<Inf> to make builds more reproducible. [perl #130133]
+
+=item *
+
+Since 5.18 for testing purposes we have included support for
+building perl with a variety of non-standard, and non-recommended
+hash functions. Since we do not recommend the use of these functions
+we have removed them and their corresponding build options. Specifically
+this includes the following build options:
+
+ PERL_HASH_FUNC_SDBM
+ PERL_HASH_FUNC_DJB2
+ PERL_HASH_FUNC_SUPERFAST
+ PERL_HASH_FUNC_MURMUR3
+ PERL_HASH_FUNC_ONE_AT_A_TIME
+ PERL_HASH_FUNC_ONE_AT_A_TIME_OLD
+ PERL_HASH_FUNC_MURMUR_HASH_64A
+ PERL_HASH_FUNC_MURMUR_HASH_64B
+
+=item *
+
+Remove "Warning: perl appears in your path"
+
+This install warning is more or less obsolete, since most platforms already
+*will* have a /usr/bin/perl or similar provided by the OS.
+
+=item *
+
+Reduce verbosity of "make install.man"
+
+Previously, two progress messages were emitted for each manpage: one by
+installman itself, and one by the function in install_lib.pl that it calls to
+actually install the file. Disabling the second of those in each case saves
+over 750 lines of unhelpful output.
+
+=item *
+
+Cleanup for clang -Weverything support. [perl 129961]
+
+=item *
+
+Configure: signbit scan was assuming too much, stop assuming negative 0.
+
+=item *
+
+Various compiler warnings have been silenced.
+
+=item *
+
+Several smaller changes have been made to remove impediments to compiling under
+C++11.
+
+=item *
+
+Builds using C<USE_PAD_RESET> now work again; this configuration had
+bit-rotted.
+
+=item *
+
+A probe for C<gai_strerror> was added to F<Configure> that checks if the
+the gai_strerror() routine is available and can be used to
+translate error codes returned by getaddrinfo() into human
+readable strings.
+
+=item *
+
+F<Configure> now aborts if both "-Duselongdouble" and "-Dusequadmath" are
+requested.
+L<[perl #126203]|https://rt.perl.org/Public/Bug/Display.html?id=126203>
+
+=item *
+
+Fixed a bug in which F<Configure> could append "-quadmath" to the archname even
+if it was already present.
+L<[perl #128538]|https://rt.perl.org/Public/Bug/Display.html?id=128538>
+
+=item *
+
+Clang builds with "-DPERL_GLOBAL_STRUCT" or "-DPERL_GLOBAL_STRUCT_PRIVATE" have
+been fixed (by disabling Thread Safety Analysis for these configurations).
+
+=item *
+
+F<make_ext.pl> no longer updates a module's F<pm_to_blib> file when no
+files require updates. This could cause dependencies, F<perlmain.c>
+in particular, to be rebuilt unnecessarily. [perl #126710]
+
+=item *
+
+The output of C<perl -V> has been reformatted so that each configuration
+and compile-time option is now listed one per line, to improve
+readability.
+
+=item *
+
+C<Configure> now builds C<miniperl> and C<generate_uudmap> if you
+invoke it with C<-Dusecrosscompiler> but not C<-Dtargethost=somehost>.
+This means you can supply your target platform C<config.sh>, generate
+the headers and proceed to build your cross-target perl. [perl #127234]
+
+=item *
+
+Builds with C<-Accflags=-DPERL_TRACE_OPS> now only dump the operator
+counts when the environment variable C<PERL_TRACE_OPS> to be set to a
+non-zero integer. This allows C<make test> to pass on such a build.
+
+=item *
+
+When building with GCC 6 and link-time optimization (the C<-flto> option to
+C<gcc>), C<Configure> was treating all probed symbols as present on the
+system, regardless of whether they actually exist. This has been fixed.
+[perl #128131]
+
+=item *
+
+The F<t/test.pl> library is used for internal testing of Perl itself, and
+also copied by several CPAN modules. Some of those modules must work on
+older versions of Perl, so F<t/test.pl> must in turn avoid newer Perl
+features. Compatibility with Perl 5.8 was inadvertently removed some time
+ago; it has now been restored. [perl #128052]
+
+=item *
+
+The build process no longer emits an extra blank line before building each
+"simple" extension (those with only F<*.pm> and F<*.pod> files).
+
+=back
+
+=head1 Testing
+
+=over 4
+
+=item *
+
+F<XS-APItest/t/utf8.t>: Several small fixes and enhancements.
+
+=item *
+
+Tests for locales were erroneously using locales incompatible with Perl.
+
+=item *
+
+Some parts of the test suite that try to exhaustively test edge cases in the
+regex implementation have been restricted to running for a maximum of five
+minutes. On slow systems they could otherwise take several hours, without
+significantly improving our understanding of the correctness of the code
+under test.
+
+In addition, some of those test cases have been split into more files, to
+allow them to be run in parallel on suitable systems.
+
+=item *
+
+A new internal facility allows analysing the time taken by the individual
+tests in Perl's own test suite; see F<Porting/harness-timer-report.pl>.
+
+=item *
+
+F<t/re/regexp_nonull.t> has been added to test that the regular expression
+engine can handle scalars that do not have a null byte just past the end of
+the string.
+
+=item *
+
+A new test script, F<t/op/decl-refs.t>, has been added to test the new feature,
+"Declaring a reference to a variable".
+
+=item *
+
+A new test script, F<t/re/anyof.t>, has been added to test that the ANYOF nodes
+generated by bracketed character classes are as expected.
+
+=item *
+
+F<t/harness> now tries really hard not to run tests outside of the Perl
+source tree. [perl #124050]
+
+=back
+
+=head1 Platform Support
+
+=head2 New Platforms
+
+=over 4
+
+=item NetBSD/VAX
+
+Perl now compiles under NetBSD on VAX machines. However, it's not
+possible for that platform to implement floating-point infinities and
+NaNs compatibly with most modern systems, which implement the IEEE-754
+floating point standard. The hexadecimal floating point (C<0x...p[+-]n>
+literals, C<printf %a>) is not implemented, either.
+The C<make test> passes 98% of tests.
+
+=over 4
+
+=item *
+
+Test fixes and minor updates.
+
+=item *
+
+Account for lack of C<inf>, C<nan>, and C<-0.0> support.
+
+=back
+
+=back
+
+=head2 Platform-Specific Notes
+
+=over 4
+
+=item Darwin
+
+don't treat -Dprefix=/usr as special, instead require an extra option
+-Ddarwin_distribution to produce the same results.
+
+=item POSIX
+
+Finish removing POSIX deprecated functions.
+
+=item OS X
+
+OS X El Capitan doesn't implement the clock_gettime() or clock_getres() APIs,
+emulate them as necessary.
+
+=item macOS
+
+Deprecated syscall(2) on macOS 10.12.
+
+=item EBCDIC
+
+Several tests have been updated to work (or be skipped) on EBCDIC platforms.
+
+=item HP-UX
+
+L<Net::Ping> UDP test is skipped on HP-UX.
+
+=item Hurd
+
+The hints for Hurd have been improved enabling malloc wrap and reporting the
+GNU libc used (previously it was an empty string when reported).
+
+=item VAX
+
+VAX floating point formats are now supported.
+
+=item VMS
+
+=over 4
+
+=item *
+
+The path separator for the C<PERL5LIB> and C<PERLLIB> environment entries is
+now a colon (C<:>) when running under a Unix shell. There is no change when
+running under DCL (it's still C<|>).
+
+=item *
+
+Remove some VMS-specific hacks from C<showlex.t>. These were added 15 years
+ago, and are no longer necessary for any VMS version now supported.
+
+=item *
+
+Move C<_pDEPTH> and C<_aDEPTH> after F<config.h> otherwise DEBUGGING
+may not be defined yet.
+
+=item *
+
+VAXC has not been a possibility for a good long while, and the versions of the
+DEC/Compaq/HP/VSI C compiler that report themselves as "DEC" in a listing file
+are 15 years or more out-of-date and can be safely desupported.
+
+=back
+
+=item Windows
+
+=over 4
+
+=item *
+
+Support for compiling perl on Windows using Microsoft Visual Studio 2015
+(containing Visual C++ 14.0) has been added.
+
+This version of VC++ includes a completely rewritten C run-time library, some
+of the changes in which mean that work done to resolve a socket close() bug in
+perl #120091 and perl #118059 is not workable in its current state with this
+version of VC++. Therefore, we have effectively reverted that bug fix for
+VS2015 onwards on the basis that being able to build with VS2015 onwards is
+more important than keeping the bug fix. We may revisit this in the future to
+attempt to fix the bug again in a way that is compatible with VS2015.
+
+These changes do not affect compilation with GCC or with Visual Studio versions
+up to and including VS2013, i.e. the bug fix is retained (unchanged) for those
+compilers.
+
+Note that you may experience compatibility problems if you mix a perl built
+with GCC or VS E<lt>= VS2013 with XS modules built with VS2015, or if you mix a
+perl built with VS2015 with XS modules built with GCC or VS E<lt>= VS2013.
+Some incompatibility may arise because of the bug fix that has been reverted
+for VS2015 builds of perl, but there may well be incompatibility anyway because
+of the rewritten CRT in VS2015 (e.g. see discussion at
+http://stackoverflow.com/questions/30412951).
+
+=back
+
+=item Win32
+
+=over 4
+
+=item *
+
+Tweaks for Win32 VC vs GCC detection makefile code. This fixes issue that CCHOME
+depends on CCTYPE, which in auto detect mode is set after CCHOME, so CCHOME uses
+the uninit CCTYPE var. Also fix else vs .ELSE in makefile.mk
+
+=item *
+
+fp definitions have been updated.
+
+=back
+
+=item VMS And Win32
+
+Fix some breakage, add 'undef' value for default_inc_excludes_dot in build
+scripts.
+
+=item Linux
+
+Drop support for Linux a.out Linux has used ELF for over twenty years.
+
+=item OpenBSD 6
+
+OpenBSD 6 still does not support returning pid, gid or uid with SA_SIGINFO.
+Make sure this is accounted for.
+
+=item FreeBSD
+
+t/uni/overload.t: Skip hanging test on FreeBSD.
+
+=back
+
+=head1 Internal Changes
+
+=over 4
+
+=item *
+
+The C<op_class()> API function has been added. This is like the existing
+C<OP_CLASS()> macro, but can more accurately determine what struct an op
+has been allocated as. For example C<OP_CLASS()> might return
+C<OA_BASEOP_OR_UNOP> indicating that ops of this type are usually
+allocated as an C<OP> or C<UNOP>; while C<op_class()> will return
+C<OPclass_BASEOP> or C<OPclass_UNOP> as appropriate.
+
+=item *
+
+The output format of the C<op_dump()> function (as used by C<perl -Dx>)
+has changed: it now displays an "ASCII-art" tree structure, and shows more
+low-level details about each op, such as its address and class.
+
+=item *
+
+New versions of macros like C<isALPHA_utf8> and C<toLOWER_utf8> have
+been added, each with the
+suffix C<_safe>, like C<isSPACE_utf8_safe>. These take an extra
+parameter, giving an upper limit of how far into the string it is safe
+to read. Using the old versions could cause attempts to read beyond the
+end of the input buffer if the UTF-8 is not well-formed, and their use
+now raises a deprecation warning. Details are at
+L<perlapi/Character classification>.
+
+=item *
+
+Calling macros like C<isALPHA_utf8> on malformed UTF-8 have issued a
+deprecation warning since Perl v5.18. They now die.
+Similarly, macros like C<toLOWER_utf8> on malformed UTF-8 now die.
+
+=item *
+
+Calling the functions C<utf8n_to_uvchr> and its derivatives, while
+passing a string length of 0 is now asserted against in DEBUGGING
+builds, and otherwise returns the Unicode REPLACEMENT CHARACTER. If
+you have nothing to decode, you shouldn't call the decode function.
+
+=item *
+
+The functions C<utf8n_to_uvchr> and its derivatives now return the
+Unicode REPLACEMENT CHARACTER if called with UTF-8 that has the overlong
+malformation, and that malformation is allowed by the input parameters.
+This malformation is where the UTF-8 looks valid syntactically, but
+there is a shorter sequence that yields the same code point. This has
+been forbidden since Unicode version 3.1.
+
+=item *
+
+The functions C<utf8n_to_uvchr> and its derivatives now accept an input
+flag to allow the overflow malformation. This malformation is when the
+UTF-8 may be syntactically valid, but the code point it represents is
+not capable of being represented in the word length on the platform.
+What "allowed" means in this case is that the function doesn't return an
+error, and advances the parse pointer to beyond the UTF-8 in question,
+but it returns the Unicode REPLACEMENT CHARACTER as the value of the
+code point (since the real value is not representable).
+
+=item *
+
+The C<PADOFFSET> type has changed from being unsigned to signed, and
+several pad-related variables such as C<PL_padix> have changed from being
+of type C<I32> to type C<PADOFFSET>.
+
+=item *
+
+The function C<L<perlapi/utf8n_to_uvchr>> has been changed to not
+abandon searching for other malformations when the first one is
+encountered. A call to it thus can generate multiple diagnostics,
+instead of just one.
+
+=item *
+
+A new function, C<L<perlapi/utf8n_to_uvchr_error>>, has been added for
+use by modules that need to know the details of UTF-8 malformations
+beyond pass/fail. Previously, the only ways to know why a sequence was
+ill-formed was to capture and parse the generated diagnostics, or to do
+your own analysis.
+
+=item *
+
+Several new functions for handling Unicode have been added to the API:
+C<L<perlapi/is_strict_utf8_string>>,
+C<L<perlapi/is_c9strict_utf8_string>>,
+C<L<perlapi/is_utf8_string_flags>>,
+C<L<perlapi/is_strict_utf8_string_loc>>,
+C<L<perlapi/is_strict_utf8_string_loclen>>,
+C<L<perlapi/is_c9strict_utf8_string_loc>>,
+C<L<perlapi/is_c9strict_utf8_string_loclen>>,
+C<L<perlapi/is_utf8_string_loc_flags>>,
+C<L<perlapi/is_utf8_string_loclen_flags>>,
+C<L<perlapi/is_utf8_fixed_width_buf_flags>>,
+C<L<perlapi/is_utf8_fixed_width_buf_loc_flags>>,
+C<L<perlapi/is_utf8_fixed_width_buf_loclen_flags>>.
+
+These functions are all extensions of the C<is_utf8_string_*()> functions,
+that apply various restrictions to the UTF-8 recognized as valid.
+
+=item *
+
+A new API function C<sv_setvpv_bufsize()> allows simultaneously setting the
+length and allocated size of the buffer in an C<SV>, growing the buffer if
+necessary.
+
+=item *
+
+A new API macro C<SvPVCLEAR()> sets its C<SV> argument to an empty string,
+like Perl-space C<$x = ''>, but with several optimisations.
+
+=item *
+
+All parts of the internals now agree that the C<sassign> op is a C<BINOP>;
+previously it was listed as a C<BASEOP> in F<regen/opcodes>, which meant
+that several parts of the internals had to be special-cased to accommodate
+it. This oddity's original motivation was to handle code like C<$x ||= 1>;
+that is now handled in a simpler way.
+
+=item *
+
+Several new internal C macros have been added that take a string literal as
+arguments, alongside existing routines that take the equivalent value as two
+arguments, a character pointer and a length. The advantage of this is that
+the length of the string is calculated automatically, rather than having to
+be done manually. These routines are now used where appropriate across the
+entire codebase.
+
+=item *
+
+The code in F<gv.c> that determines whether a variable has a special meaning
+to Perl has been simplified.
+
+=item *
+
+The C<DEBUGGING>-mode output for regex compilation and execution has been
+enhanced.
+
+=item *
+
+Several macros and functions have been added to the public API for
+dealing with Unicode and UTF-8-encoded strings. See
+L<perlapi/Unicode Support>.
+
+=item *
+
+Use C<my_strlcat()> in C<locale.c>. While C<strcat()> is safe in this context,
+some compilers were optimizing this to C<strcpy()> causing a porting test to
+fail that looks for unsafe code. Rather than fighting this, we just use
+C<my_strlcat()> instead.
+
+=item *
+
+Three new ops, C<OP_ARGELEM>, C<OP_ARGDEFELEM> and C<OP_ARGCHECK> have
+been added. These are intended principally to implement the individual
+elements of a subroutine signature, plus any overall checking required.
+
+=item *
+
+Perl no longer panics when switching into some locales on machines with
+buggy C<strxfrm()> implementations in their libc. [perl #121734]
+
+=item *
+
+Perl is now built with the C<PERL_OP_PARENT> compiler define enabled by
+default. To disable it, use the C<PERL_NO_OP_PARENT> compiler define.
+This flag alters how the C<op_sibling> field is used in C<OP> structures,
+and has been available optionally since perl 5.22.0.
+
+See L<perl5220delta/"Internal Changes"> for more details of what this
+build option does.
+
+=item *
+
+The meanings of some internal SV flags have been changed
+
+OPpRUNTIME, SVpbm_VALID, SVpbm_TAIL, SvTAIL_on, SvTAIL_off, SVrepl_EVAL,
+SvEVALED
+
+=item *
+
+Change C<hv_fetch(…, "…", …, …)> to C<hv_fetchs(…, "…", …)>
+
+The dual-life dists all use Devel::PPPort, so they can use this function even
+though it was only added in 5.10.
+
+=back
+
+=head1 Selected Bug Fixes
+
+=over 4
+
+=item *
+
+C< $-{$name} > would leak an C<AV> on each access if the regular
+expression had no named captures. The same applies to access to any
+hash tied with L<Tie::Hash::NamedCapture> and C<< all =E<gt> 1 >>. [perl
+#130822]
+
+=item *
+
+Attempting to use the deprecated variable C<$#> as the object in an
+indirect object method call could cause a heap use after free or
+buffer overflow. [perl #129274]
+
+=item *
+
+When checking for an indirect object method call in some rare cases
+the parser could reallocate the line buffer but then continue to use
+pointers to the old buffer. [perl #129190]
+
+=item *
+
+Supplying a glob as the format argument to L<perlfunc/formline> would
+cause an assertion failure. [perl #130722]
+
+=item *
+
+Code like C< $value1 =~ qr/.../ ~~ $value2 > would have the match
+converted into a qr// operator, leaving extra elements on the stack to
+confuse any surrounding expression. [perl #130705]
+
+=item *
+
+Since 5.24.0 in some obscure cases, a regex which included code blocks
+from multiple sources (e.g. via embedded via qr// objects) could end up
+with the wrong current pad and crash or give weird results. [perl #129881]
+
+=item *
+
+Occasionally C<local()>s in a code block within a patterns weren't being
+undone when the pattern matching backtracked over the code block.
+[perl #126697]
+
+=item *
+
+Using C<substr()> to modify a magic variable could access freed memory
+in some cases. [perl #129340]
+
+=item *
+
+Perl 5.25.9 was fixed so that under C<use utf8>, the entire Perl program
+is checked that the UTF-8 is wellformed. It turns out that several edge
+cases were missed, and are now fixed. [perl #126310] was the original
+ticket.
+
+=item *
+
+Under C<use utf8>, the entire Perl program is now checked that the UTF-8
+is wellformed. This resolves [perl #126310].
+
+=item *
+
+The range operator C<..> on strings now handles its arguments correctly when in
+the scope of the L<< C<unicode_strings>|feature/"The 'unicode_strings' feature" >>
+feature. The previous behaviour was sufficiently unexpected that we believe no
+correct program could have made use of it.
+
+=item *
https://perl5.git.perl.org / perl5.git / blobdiff