This is a synonym for C<\p{Any}> and matches the set of Unicode-defined
code points 0 - 0x10FFFF.
+=head2 C<S<use locale>> now compiles on systems without locale ability
+
+Previously doing this caused the program to not compile. Within its
+scope the program behaves as if in the "C" locale. Thus programs
+written for platforms that support locales can run on locale-less
+platforms without change. Attempts to change the locale away from the
+"C" locale will, of course, fail.
+
+=head2 PERL_DEBUG_READONLY_COW
+
+On some operating systems Perl can be compiled in such a way that any
+attempt to modify string buffers shared by multiple SVs will crash. This
+way XS authors can test that their modules handle copy-on-write scalars
+correctly. See L<perlguts/"Copy on Write"> for detail.
+
+This feature was actually added in 5.19.8, but was unintentionally omitted
+from its delta document.
+
+=head2 C<-DL> runtime option now added for tracing locale setting
+
+This is designed for Perl core developers to aid in field debugging bugs
+regarding locales.
+
+=head2 Subroutine signatures
+
+Declarative syntax to unwrap argument list into lexical variables.
+C<sub foo ($a,$b) {...}> checks the number of arguments and puts the
+arguments into lexical variables. Signatures are not equivalent to
+the existing idiom of C<sub foo { my($a,$b) = @_; ... }>. Signatures
+are only available by enabling a non-default feature, and generate
+warnings about being experimental. The syntactic clash with
+prototypes is managed by disabling the short prototype syntax when
+signatures are enabled.
+
+See L<perlsub/Signatures> for details.
+
+=head2 More locale initialization fallback options
+
+If there was an error with locales during Perl start-up, it immediately
+gave up and tried to use the C<"C"> locale. Now it first tries using
+other locales given by the environment variables, as detailed in
+L<perllocale/ENVIRONMENT>. For example, if C<LC_ALL> and C<LANG> are
+both set, and using the C<LC_ALL> locale fails, Perl will now try the
+C<LANG> locale, and only if that fails, will it fall back to C<"C">. On
+Windows machines, Perl will try, ahead of using C<"C">, the system
+default locale if all the locales given by environment variables fail.
+
=head1 Security
=head2 Avoid possible read of free()d memory during parsing
C<\p{All}> is no longer synonymous with C<\p{Any}>, which continues to
match just the Unicode code points, as Unicode says it should.
+=head2 Tainting happens under more circumstances; now conforms to documentation
+
+This affects regular expression matching and changing the case of a
+string (C<lc>, C<"\U">, I<etc>.) within the scope of C<use locale>.
+The result is now tainted based on the operation, no matter what the
+contents of the string were, as the documentation (L<perlsec>,
+L<perllocale/SECURITY>) indicates it should. Previously, for the case
+change operation, if the string contained no characters whose case
+change could be affected by the locale, the result would not be tainted.
+For example, the result of C<uc()> on an empty string or one containing
+only above-Latin1 code points is now tainted, and wasn't before. This
+leads to more consistent tainting results. Regular expression patterns
+taint their non-binary results (like C<$&>, C<$2>) if and only if the
+pattern contains elements whose matching depends on the current
+(potentially tainted) locale. Like the case changing functions, the
+actual contents of the string being matched now do not matter, whereas
+formerly it did. For example, if the pattern contains a C<\w>, the
+results will be tainted even if the match did not have to use that
+portion of the pattern to succeed or fail, because what a C<\w> matches
+depends on locale. However, for example, a C<.> in a pattern will not
+enable tainting, because the dot matches any single character, and what
+the current locale is doesn't change in any way what matches and what
+doesn't.
+
+=head2 Quote-like escape changes
+
+The character after C<\c> in a double-quoted string ("..." or qq(...))
+or regular expression must now be a printable character and may not be
+C<{>.
+
+A literal C<{> after C<\B> or C<\b> is now fatal.
+
+These were deprecated in perl v5.14.
+
=head1 Deprecations
+=head2 The C</\C/> character class
+
The C</\C/> regular expression character class is deprecated. From perl
5.22 onwards it will generate a warning, and from perl 5.24 onwards it
will be a regular expression compiler error. If you need to examine the
their usage not being portable to non-ASCII platforms: While $^T will work
everywhere, \cT is whitespace in EBCDIC. [perl #119123]
+=head2 References to non-integers and non-positive integers in C<$/>
+
+Setting C<$/> to a reference to zero or a reference to a negative integer is
+now deprecated, and will behave B<exactly> as though it was set to C<undef>.
+If you want slurp behavior set C<$/> to C<undef> explicitly.
+
+Setting C<$/> to a reference to a non integer is now forbidden and will
+throw an error. Perl has never documented what would happen in this
+context and while it used to behave the same as setting C<$/> to
+the address of the references in future it may behave differently, so we
+have forbidden this usage.
+
+=head2 Character matching routines in POSIX
+
+Use of any of these functions in the C<POSIX> module is now deprecated:
+C<isalnum>, C<isalpha>, C<iscntrl>, C<isdigit>, C<isgraph>, C<islower>,
+C<isprint>, C<ispunct>, C<isspace>, C<isupper>, and C<isxdigit>. The
+functions are buggy and don't work on UTF-8 encoded strings. See their
+entries in L<POSIX> for more information.
+
+A warning is raised on the first call to any of them from each place in
+the code that they are called. (Hence a repeated statement in a loop
+will raise just the one warning.)
+
=head2 Module removals
The following modules will be removed from the core distribution in a
[perl #120765]
+=item *
+
+Code like:
+
+ my $x; # or @x, %x
+ my $y;
+
+is now optimized to:
+
+ my ($x, $y);
+
+In combination with the padrange optimization, this means longer
+uninitialized my variable statements are also optimized, so:
+
+ my $x; my @y; my %z;
+
+becomes:
+
+ my ($x, @y, %z);
+
+[perl #121077]
+
=back
=head1 Modules and Pragmata
C<blessed>, C<isa> and C<reftype> when dealing with references to blessed
objects.
+=item *
+
+L<perlfunc/exec>'s handling of arguments is now more clearly
+documented.
+
=back
=head3 L<perlguts>
Numerous minor changes have been made to reflect changes made to the perl
internals in this release.
+=item *
+
+New sections on L<Read-Only Values|perlguts/"Read-Only Values"> and
+L<Copy on Write|perlguts/"Copy on Write"> have been added. They were
+actually added in 5.19.8 but accidentally omitted from its delta document.
+
=back
=head3 L<perlhack>
subroutine from the same slot. You are asking Perl to do something it cannot
do, details subject to change between Perl versions.
+=item *
+
+Added L<Setting $E<sol> to a %s reference is forbidden|perldiag/"Setting $E<sol> to %s reference is forbidden">
+
=back
=head3 New Warnings
This replaces the message "Code point 0x%X is not Unicode, all \p{}
matches fail; all \P{} matches succeed".
+=item *
+
+Added L<Setting $E<sol> to a reference to %s as a form of slurp is deprecated, treating as undef|perldiag/"Setting $E<sol> to a reference to %s as a form of slurp is deprecated, treating as undef">
+
=back
=head1 Utility Changes
This is a huge time saver if cross-compiling, but can also help
on native builds if your toolchain's files have non-standard locations.
+=item *
+
+The cross-compilation model has been renovated.
+There's several new options, and some backwards-incompatible changes:
+
+We now build binaries for miniperl and generate_uudmap to be used on the host, rather than running
+every miniperl call on the target; this means that, short of 'make test',
+we no longer need access to the target system once Configure is done.
+You can provide already-built binaries through the C<hostperl> and
+C<hostgenerate> options to Configure.
+
+Additionally, if targeting an EBCDIC platform from an ASCII host,
+or viceversa, you'll need to run Configure with C<-Uhostgenerate>, to
+indicate that generate_uudmap should be run on the target.
+
+Finally, there's also a way of having Configure end early, right after
+building the host binaries, by cross-compiling without specifying a
+C<targethost>.
+
+The incompatible changes include no longer using xconfig.h, xlib, or
+Cross.pm, so canned config files and Makefiles will have to be updated.
+
+=item *
+
+Related to the above, there is now a way of specifying the location of sh
+(or equivalent) on the target system: C<targetsh>.
+
+For example, Android has its sh in /system/bin/sh, so if cross-compiling
+from a more normal Unixy system with sh in /bin/sh, "targetsh" would end
+up as /system/bin/sh, and "sh" as /bin/sh.
+
=back
=head1 Platform Support
=over 4
+=item Android
+
+Perl can now be built for Android, either natively or through
+cross-compilation, for all three currently available architectures (ARM,
+MIPS, and x86), on a wide range of versions.
+
=item Bitrig
Compile support has been added for Bitrig, a fork of OpenBSD.
an empty string when recvfrom(2) doesn't modify the supplied address
length. [perl #118843]
+=item VMS
+
+Skip access checks on remotes in opendir(). [perl #121002]
+
+=item Cygwin
+
+Fixed a build error in cygwin.c on Cygwin 1.7.28.
+
+Tests now handle the errors that occur when C<cygserver> isn't
+running.
+
=back
=head1 Internal Changes
machine. Previously it always displayed raw bytes, which is what it
still does for non-representable code points.
+=item *
+
+Regexp Engine Changes That Affect The Pluggable Regex Engine Interface
+
+Many flags that used to be exposed via regexp.h and used to populate the
+extflags member of struct regexp have been removed. These fields were
+technically private to Perl's own regexp engine and should not have been
+exposed there in the first place.
+
+The affected flags are:
+
+ RXf_NOSCAN
+ RXf_CANY_SEEN
+ RXf_GPOS_SEEN
+ RXf_GPOS_FLOAT
+ RXf_ANCH_BOL
+ RXf_ANCH_MBOL
+ RXf_ANCH_SBOL
+ RXf_ANCH_GPOS
+
+As well as the follow flag masks:
+
+ RXf_ANCH_SINGLE
+ RXf_ANCH
+
+All have been renamed to PREGf_ equivalents and moved to regcomp.h.
+
+The behavior previously achieved by setting one or more of the RXf_ANCH_
+flags (via the RXf_ANCH mask) have now been replaced by a *single* flag bit
+in extflags:
+
+ RXf_IS_ANCHORED
+
+pluggable regex engines which previously used to set these flags should
+now set this flag ALONE.
+
=back
=head1 Selected Bug Fixes
In Perl v5.18 C<undef *_; goto &sub> and C<local *_; goto &sub> started
crashing. This has been fixed. [perl #119949]
+=item *
+
+Backticks (C< `` > or C< qx// >) combined with multiple threads on
+Win32 could result in output sent to stdout on one thread being
+captured by backticks of an external command in another thread.
+
+This could occur for pseudo-forked processes too, as Win32's
+pseudo-fork is implemented in terms of threads. [perl #77672]
+
+=item *
+
+C<< open $fh, ">+", undef >> no longer leaks memory when TMPDIR is set
+but points to a directory a temporary file cannot be created in. [perl
+#120951]
+
+=item *
+
+C<$^R> wasn't available outside of the regular expression that
+initialized it. [perl #121070]
+
+=item *
+
+Fixed a regular expression bug introduced in 5.19.5 where \S, \W etc
+could fail for above ASCII. [perl #121144]
+
+=item *
+
+A large set of fixes and refactoring for re_intuit_start() was merged,
+the highlights are:
+
+=over
+
+=item *
+
+Fixed a panic when compiling the regular expression
+C</\x{100}[xy]\x{100}{2}/>.
+
+=item *
+
+Fixed a performance regression when performing a global pattern match
+against a UTF-8 string. [perl #120692]
+
+=item *
+
+Fixed another performance issue where matching a regular expression
+like C</ab.{1,2}x/> against a long UTF-8 string would unnecessarily
+calculate byte offsets for a large portion of the string. [perl
+#120692]
+
+=back
+
+=item *
+
+C< for ( $h{k} || '' ) > no longer auto-vivifies C<$h{k}>. [perl
+#120374]
+
+=item *
+
+On Windows machines, Perl now emulates the POSIX use of the environment
+for locale initialization. Previously, the environment was ignored.
+See L<perllocale/ENVIRONMENT>.
+
+=item *
+
+Fixed a crash when destroying a self-referencing GLOB. [perl #121242]
+
+=item *
+
+Call set-magic when setting $DB::sub. [perl #121255]
+
+=item *
+
+Fixed an alignment error when compiling regular expressions when built
+with GCC on HP-UX 64-bit.
+
=back
=head1 Known Problems
projects / platform / upstream / perl.git / commitdiff