5 perl5110delta - what is new for perl v5.11.0
9 This document describes differences between the 5.10.0 release and
10 the 5.11.0 development release.
12 =head1 Incompatible Changes
14 =head2 In @INC, move ARCHLIB and PRIVLIB after the current version's site_perl and vendor_perl.
16 =head2 Switch statement changes
18 The handling of complex expressions by the C<given>/C<when> switch
19 statement has been enhanced. These enhancements are also available in
20 5.10.1 and subsequent 5.10 releases. There are two new cases where C<when> now
21 interprets its argument as a boolean, instead of an expression to be used
26 =item flip-flop operators
28 The C<..> and C<...> flip-flop operators are now evaluated in boolean
29 context, following their usual semantics; see L<perlop/"Range Operators">.
31 Note that, as in perl 5.10.0, C<when (1..10)> will not work to test
32 whether a given value is an integer between 1 and 10; you should use
33 C<when ([1..10])> instead (note the array reference).
35 However, contrary to 5.10.0, evaluating the flip-flop operators in boolean
36 context ensures it can now be useful in a C<when()>, notably for
37 implementing bistable conditions, like in:
39 when (/^=begin/ .. /^=end/) {
43 =item defined-or operator
45 A compound expression involving the defined-or operator, as in
46 C<when (expr1 // expr2)>, will be treated as boolean if the first
47 expression is boolean. (This just extends the existing rule that applies
48 to the regular or operator, as in C<when (expr1 || expr2)>.)
52 The next section details more changes brought to the semantics to
53 the smart match operator, that naturally also modify the behaviour
54 of the switch statements where smart matching is implicitly used.
55 These changers were also made for the 5.10.1 release, and will remain in
56 subsequent 5.10 releases.
58 =head2 Smart match changes
60 =head3 Changes to type-based dispatch
62 The smart match operator C<~~> is no longer commutative. The behaviour of
63 a smart match now depends primarily on the type of its right hand
64 argument. Moreover, its semantics have been adjusted for greater
65 consistency or usefulness in several cases. While the general backwards
66 compatibility is maintained, several changes must be noted:
72 Code references with an empty prototype are no longer treated specially.
73 They are passed an argument like the other code references (even if they
78 C<%hash ~~ sub {}> and C<@array ~~ sub {}> now test that the subroutine
79 returns a true value for each key of the hash (or element of the
80 array), instead of passing the whole hash or array as a reference to
85 Due to the commutativity breakage, code references are no longer
86 treated specially when appearing on the left of the C<~~> operator,
87 but like any vulgar scalar.
91 C<undef ~~ %hash> is always false (since C<undef> can't be a key in a
92 hash). No implicit conversion to C<""> is done (as was the case in perl
97 C<$scalar ~~ @array> now always distributes the smart match across the
98 elements of the array. It's true if one element in @array verifies
99 C<$scalar ~~ $element>. This is a generalization of the old behaviour
100 that tested whether the array contained the scalar.
104 The full dispatch table for the smart match operator is given in
105 L<perlsyn/"Smart matching in detail">.
107 =head3 Smart match and overloading
109 According to the rule of dispatch based on the rightmost argument type,
110 when an object overloading C<~~> appears on the right side of the
111 operator, the overload routine will always be called (with a 3rd argument
112 set to a true value, see L<overload>.) However, when the object will
113 appear on the left, the overload routine will be called only when the
114 rightmost argument is a simple scalar. This way distributivity of smart match
115 across arrays is not broken, as well as the other behaviours with complex
116 types (coderefs, hashes, regexes). Thus, writers of overloading routines
117 for smart match mostly need to worry only with comparing against a scalar,
118 and possibly with stringification overloading; the other common cases
119 will be automatically handled consistently.
121 C<~~> will now refuse to work on objects that do not overload it (in order
122 to avoid relying on the object's underlying structure). (However, if the
123 object overloads the stringification or the numification operators, and
124 if overload fallback is active, it will be used instead, as usual.)
126 =head2 Labels can't be keywords
128 Labels used as targets for the C<goto>, C<last>, C<next> or C<redo>
129 statements cannot be keywords anymore. This restriction will prevent
130 potential confusion between the C<goto LABEL> and C<goto EXPR> syntaxes:
131 for example, a statement like C<goto print> would jump to a label whose
132 name would be the return value of print(), (usually 1), instead of a
133 label named C<print>. Moreover, the other control flow statements
134 would just ignore any keyword passed to them as a label name. Since
135 such labels cannot be defined anymore, this kind of error will be
138 =head2 Other incompatible changes
144 The semantics of C<use feature :5.10*> have changed slightly.
145 See L<"Modules and Pragmata"> for more information.
149 It is now a run-time error to use the smart match operator C<~~>
150 with an object that has no overload defined for it. (This way
151 C<~~> will not break encapsulation by matching against the
152 object's internal representation as a reference.)
156 The version control system used for the development of the perl
157 interpreter has been switched from Perforce to git. This is mainly an
158 internal issue that only affects people actively working on the perl core;
159 but it may have minor external visibility, for example in some of details
160 of the output of C<perl -V>. See L<perlrepository> for more information.
164 The internal structure of the C<ext/> directory in the perl source has
165 been reorganised. In general, a module C<Foo::Bar> whose source was
166 stored under F<ext/Foo/Bar/> is now located under F<ext/Foo-Bar/>. Also,
167 some modules have been moved from F<lib/> to F<ext/>. This is purely a
168 source tarball change, and should make no difference to the compilation or
169 installation of perl, unless you have a very customised build process that
170 explicitly relies on this structure, or which hard-codes the C<nonxs_ext>
171 F<Configure> parameter. Specifically, this change does not by default
172 alter the location of any files in the final installation.
176 As part of the C<Test::Harness> 2.x to 3.x upgrade, the experimental
177 C<Test::Harness::Straps> module has been removed.
178 See L</"Updated Modules"> for more details.
182 As part of the C<ExtUtils::MakeMaker> upgrade, the
183 C<ExtUtils::MakeMaker::bytes> and C<ExtUtils::MakeMaker::vmsish> modules
184 have been removed from this distribution.
188 C<Module::CoreList> no longer contains the C<%:patchlevel> hash.
192 This one is actually a change introduced in 5.10.0, but it was missed
193 from that release's perldelta, so it is mentioned here instead.
195 A bugfix related to the handling of the C</m> modifier and C<qr> resulted
196 in a change of behaviour between 5.8.x and 5.10.0:
198 # matches in 5.8.x, doesn't match in 5.10.0
199 $re = qr/^bar/; "foo\nbar" =~ /$re/m;
203 C<length undef> now returns undef.
207 =head1 Core Enhancements
209 =head2 Unicode Character Database 5.1.0
211 The copy of the Unicode Character Database included in Perl 5.11.0 has
212 been updated to 5.1.0 from 5.0.0. See
213 L<http://www.unicode.org/versions/Unicode5.1.0/#Notable_Changes> for the
216 =head2 A proper interface for pluggable Method Resolution Orders
218 As of Perl 5.11.0 there is a new interface for plugging and using method
219 resolution orders other than the default (linear depth first search).
220 The C3 method resolution order added in 5.10.0 has been re-implemented as
221 a plugin, without changing its Perl-space interface. See L<perlmroapi> for
224 =head2 The C<overloading> pragma
226 This pragma allows you to lexically disable or enable overloading
227 for some or all operations. (Yuval Kogman)
229 =head2 C<\N> regex escape
231 A new regex escape has been added, C<\N>. It will match any character that
232 is not a newline, independently from the presence or absence of the single
233 line match modifier C</s>. (If C<\N> is followed by an opening brace and
234 by a letter, perl will still assume that a Unicode character name is
235 coming, so compatibility is preserved.) (Rafael Garcia-Suarez)
237 =head2 Implicit strictures
239 Using the C<use VERSION> syntax with a version number greater or equal
240 to 5.11.0 will also lexically enable strictures just like C<use strict>
241 would do (in addition to enabling features.) So, the following:
250 =head2 Parallel tests
252 The core distribution can now run its regression tests in parallel on
253 Unix-like platforms. Instead of running C<make test>, set C<TEST_JOBS> in
254 your environment to the number of tests to run in parallel, and run
255 C<make test_harness>. On a Bourne-like shell, this can be done as
257 TEST_JOBS=3 make test_harness # Run 3 tests in parallel
259 An environment variable is used, rather than parallel make itself, because
260 L<TAP::Harness> needs to be able to schedule individual non-conflicting test
261 scripts itself, and there is no standard interface to C<make> utilities to
262 interact with their job schedulers.
264 Note that currently some test scripts may fail when run in parallel (most
265 notably C<ext/IO/t/io_dir.t>). If necessary run just the failing scripts
266 again sequentially and see if the failures go away.
268 =head2 The C<...> operator
270 A new operator, C<...>, nicknamed the Yada Yada operator, has been added.
271 It is intended to mark placeholder code, that is not yet implemented.
272 See L<perlop/"Yada Yada Operator">. (chromatic)
274 =head2 DTrace support
276 Some support for DTrace has been added. See "DTrace support" in F<INSTALL>.
278 =head2 Support for C<configure_requires> in CPAN module metadata
280 Both C<CPAN> and C<CPANPLUS> now support the C<configure_requires> keyword
281 in the F<META.yml> metadata file included in most recent CPAN distributions.
282 This allows distribution authors to specify configuration prerequisites that
283 must be installed before running F<Makefile.PL> or F<Build.PL>.
285 See the documentation for C<ExtUtils::MakeMaker> or C<Module::Build> for more
286 on how to specify C<configure_requires> when creating a distribution for CPAN.
288 =head2 The C<each> function can now operate on arrays
290 =head2 Perl's core time-related functions are now Y2038 compliand
292 =head2 The variable C<$,> may now be tied
294 =head2 // now behaves like || in when clauses
296 =head2 You can now set C<-W> from the C<PERL5OPT> environment varialbe
298 =head1 Modules and Pragmata
300 =head2 New Modules and Pragmata
306 This is a new lexically-scoped alternative for the C<Fatal> module.
307 The bundled version is 2.06_01. Note that in this release, using a string
308 eval when C<autodie> is in effect can cause the autodie behaviour to leak
309 into the surrounding scope. See L<autodie/"BUGS"> for more details.
311 =item C<Compress::Raw::Bzip2>
313 This has been added to the core (version 2.020).
317 This pragma establishes an ISA relationship with base classes at compile
318 time. It provides the key feature of C<base> without the feature creep.
320 =item C<Parse::CPAN::Meta>
322 This has been added to the core (version 1.39).
326 =head2 Pragmata Changes
332 See L</"The C<overloading> pragma"> above.
336 Upgraded from version 0.08 to 0.09.
340 The C<attrs> pragma has been removed. It had been marked as deprecated since
345 Upgraded from version 2.13 to 2.14. See L<parent> for a replacement.
349 Upgraded from version 0.22 to 0.23.
353 Upgraded from version 0.22 to 0.23.
357 Upgraded from version 0.22 to 0.23.
361 Upgraded from version 1.06 to 1.07.
363 The Unicode F<NameAliases.txt> database file has been added. This has the
364 effect of adding some extra C<\N> character names that formerly wouldn't
365 have been recognised; for example, C<"\N{LATIN CAPITAL LETTER GHA}">.
369 Upgraded from version 1.13 to 1.19. Some code has been shifted from run time to
370 compile time, and the amount of MRO cache flushing has been minimised.
374 The meaning of the C<:5.10> and C<:5.10.X> feature bundles has
375 changed slightly. The last component, if any (i.e. C<X>) is simply ignored.
376 This is predicated on the assumption that new features will not, in
377 general, be added to maintenance releases. So C<:5.10> and C<:5.10.X>
378 have identical effect. This is a change to the behaviour documented for
383 Upgraded from version 2.13 to 2.14 (this was just a version bump; there
384 were no functional changes).
388 Upgraded from version 0.5565 to 0.62.
392 Upgraded from version 1.06 to 1.07.
396 Upgraded from version 1.06 to 1.07.
400 See L</"The C<overloading> pragma"> above.
404 Upgraded from version 0.74 to 0.77.
408 =head2 Updated Modules
412 =item C<Archive::Extract>
414 Upgraded from version 0.24 to 0.34.
416 =item C<Archive::Tar>
418 Upgraded from version 1.38 to 1.52.
420 =item C<Attribute::Handlers>
422 Upgraded from version 0.79 to 0.85.
426 Upgraded from version 5.63 to 5.68.
430 Upgraded from version 1.05 to 1.06.
434 Upgraded from version 1.17 to 1.22.
438 Upgraded from version 1.05 to 1.11.
442 Upgraded from version 0.83 to 0.89.
446 Upgraded from version 1.09 to 1.11.
450 Upgraded from version 1.01 to 1.02.
454 Upgraded from version 1.10 to 1.11.
458 Upgraded from version 1.08 to 1.11.
460 L<Carp> now includes all the necessary code to function. Previously, it
461 used to be a lightweight placeholder that loaded the actual code from
462 C<Carp::Heavy> on demand. C<Carp::Heavy> is now a simple, empty module
463 kept for backwards compatibility for programs that used to pre-load it.
467 Upgraded from version 3.29 to 3.43.
468 (also includes the "default_value for popup_menu()" fix from 3.45).
470 =item C<Compress::Zlib>
472 Upgraded from version 2.008 to 2.020.
476 Upgraded from version 1.9205 to 1.9402. C<CPAN::FTP> has a local fix to
477 stop it being too verbose on download failure.
481 Upgraded from version 0.84 to 0.88.
483 =item C<CPANPLUS::Dist::Build>
485 Upgraded from version 0.06_02 to 0.36.
489 Upgraded from version 3.25_01 to 3.30.
491 =item C<Data::Dumper>
493 Upgraded from version 2.121_14 to 2.124.
497 Upgraded from version 1.01 to 1.02.
501 Upgraded from version 1.816_1 to 1.820.
503 =item C<Devel::PPPort>
505 Upgraded from version 3.13 to 3.19.
509 Upgraded from version 2.36_01 to 2.39.
513 Upgraded from version 5.45 to 5.47.
517 Upgraded from version 1.01 to 1.03.
521 Upgraded from version 1.12 to 1.13.
525 Upgraded from version 1.08 to 1.10.
529 Upgraded from version 2.23 to 2.35.
533 Upgraded from version 1.10 to 1.11.
537 Upgraded from version 5.62 to 5.63.
539 =item C<ExtUtils::CBuilder>
541 Upgraded from version 0.21 to 0.2602.
543 =item C<ExtUtils::Command>
545 Upgraded from version 1.13 to 1.16.
547 =item C<ExtUtils::Constant>
549 Upgraded from 0.20 to 0.22. (Note that neither of these versions are
552 =item C<ExtUtils::Embed>
554 Upgraded from version 1.27 to 1.28.
556 =item C<ExtUtils::Install>
558 Upgraded from version 1.44 to 1.54.
560 =item C<ExtUtils::MakeMaker>
562 Upgraded from version 6.42 to 6.55_02.
564 Note that C<ExtUtils::MakeMaker::bytes> and C<ExtUtils::MakeMaker::vmsish>
565 have been removed from this distribution.
567 =item C<ExtUtils::Manifest>
569 Upgraded from version 1.51_01 to 1.56.
571 =item C<ExtUtils::ParseXS>
573 Upgraded from version 2.18_02 to 2.2002.
577 Upgraded from version 1.05 to 2.06_01. See also the new pragma C<autodie>.
579 =item C<File::Basename>
581 Upgraded from version 2.76 to 2.77.
583 =item C<File::Compare>
585 Upgraded from version 1.1005 to 1.1006.
589 Upgraded from version 2.11 to 2.16.
591 File::Copy now always return 0 (not "") on failure.
593 FIXME - describe C<cp>
597 Upgraded from version 0.14 to 0.20.
601 Upgraded from version 1.12 to 1.14.
605 Upgraded from version 2.04 to 2.07_03.
609 Upgraded from version 3.2501 to 3.30.
613 Upgraded from version 1.00 to 1.01.
615 Added -X overloading, -M, -C and -A.
619 Upgraded from version 0.18 to 0.22.
623 Upgraded from version 1.07 to 1.08.
627 Upgraded from version 2.01 to 2.02.
629 =item C<Filter::Simple>
631 Upgraded from version 0.82 to 0.84.
633 =item C<Filter::Util::Call>
635 Upgraded from version 1.07 to 1.08.
639 Upgraded from version 1.49 to 1.50.
643 Upgraded from version 1.08 to 1.09.
645 =item C<Getopt::Long>
647 Upgraded from version 2.37 to 2.38.
649 =item C<Hash::Util::FieldHash>
651 Upgraded from version 1.03 to 1.04. This fixes a memory leak.
653 =item C<I18N::Collate>
655 Upgraded from version 1.00 to 1.01.
659 Upgraded from version 1.23_01 to 1.25.
661 This makes non-blocking mode work on Windows in C<IO::Socket::INET>
664 =item C<IO::Compress::*>
666 Upgraded from version 2.008 to 2.020.
670 Upgraded from version 1.06 to 1.07.
674 Upgraded from version 1.27 to 1.28.
678 Upgraded from version 1.30_01 to 1.31.
682 Upgraded from version 1.07 to 1.09.
686 Upgraded from version 0.40_1 to 0.46.
690 Upgraded from version 1.02 to 1.04.
694 Upgraded from version 1.05 to 2.01.
698 Upgraded from version 0.5565 to 0.62.
702 Upgraded from version 1.19 to 1.21.
704 =item C<Locale::MakeText>
706 Upgraded from version 1.12 to 1.13.
708 =item C<Log::Message>
710 Upgraded from version 0.01 to 0.02.
712 =item C<Math::BigFloat>
714 Upgraded from version 1.59 to 1.60.
716 =item C<Math::BigInt>
718 Upgraded from version 1.88 to 1.89.
720 =item C<Math::BigInt::FastCalc>
722 Upgraded from version 0.16 to 0.19.
724 =item C<Math::BigRat>
726 Upgraded from version 0.21 to 0.22.
728 =item C<Math::Complex>
730 Upgraded from version 1.37 to 1.56.
734 Upgraded from version 1.04 to 1.20.
738 Upgraded from version 1.01_02 to 1.01_03 (just a minor documentation
741 =item C<Module::Build>
743 Upgraded from version 0.2808_01 to 0.34_02.
745 =item C<Module::CoreList>
747 Upgraded from version 2.13 to 2.18. This release no longer contains the
748 C<%Module::CoreList::patchlevel> hash.
750 =item C<Module::Load>
752 Upgraded from version 0.12 to 0.16.
754 =item C<Module::Load::Conditional>
756 Upgraded from version 0.22 to 0.30.
758 =item C<Module::Loaded>
760 Upgraded from version 0.01 to 0.02.
762 =item C<Module::Pluggable>
764 Upgraded from version 3.6 to 3.9.
768 Upgraded from version 1.07 to 1.08.
772 Upgraded from version 2.33 to 2.36.
776 Upgraded from version 0.60_01 to 0.64.
778 =item C<Object::Accessor>
780 Upgraded from version 0.32 to 0.34.
784 Upgraded from version 1.03 to 1.04.
786 =item C<Package::Constants>
788 Upgraded from version 0.01 to 0.02.
792 Upgraded from version 1.04 to 1.06.
796 Upgraded from version 0.04 to 0.07.
800 Upgraded from version 2.16 to 2.22.
804 Upgraded from version 1.35 to 1.37.
808 Upgrade from version 3.14_02 to 3.15.
812 Upgraded from version 3.05 to 3.07.
816 Upgraded from version 3.08 to 3.13.
820 Upgraded from version 1.13 to 1.17.
824 Upgraded from 2.12 to 2.18.
826 =item C<Scalar::Util>
828 Upgraded from version 1.19 to 1.21.
832 Upgraded from 1.01 to 1.02.
836 Upgraded from 1.11 to 1.17.
840 Upgraded from 1.80 to 1.82.
844 Upgraded from 2.18 to 2.20.
848 Upgraded from version 2.13 to 2.14. Please see L</Deprecations>.
852 Upgraded from version 1.06 to 1.07.
856 Upgraded from version 0.22 to 0.27.
858 =item C<Term::ANSIColor>
860 Upgraded from version 1.12 to 2.01.
862 =item C<Term::ReadLine>
864 Upgraded from version 1.03 to 1.04.
868 Upgraded from version 0.18 to 0.20.
870 =item C<Test::Harness>
872 Upgraded from version 2.64 to 3.17.
874 Note that one side-effect of the 2.x to 3.x upgrade is that the
875 experimental C<Test::Harness::Straps> module (and its supporting
876 C<Assert>, C<Iterator>, C<Point> and C<Results> modules) have been
877 removed. If you still need this, then they are available in the
878 (unmaintained) C<Test-Harness-Straps> distribution on CPAN.
880 =item C<Test::Simple>
882 Upgraded from version 0.72 to 0.92.
884 =item C<Text::ParseWords>
886 Upgraded from version 3.26 to 3.27.
890 Upgraded from version 2007.1117 to 2009.0305.
894 Upgraded from version 2006.1117 to 2009.0305.
896 =item C<Thread::Queue>
898 Upgraded from version 2.00 to 2.11.
900 =item C<Thread::Semaphore>
902 Upgraded from version 2.01 to 2.09.
906 Upgraded from version 1.67 to 1.73.
908 =item C<threads::shared>
910 Upgraded from version 1.14 to 1.29.
912 =item C<Tie::RefHash>
914 Upgraded from version 1.37 to 1.38.
916 =item C<Tie::StdHandle>
918 This has documentation changes, and has been assigned a version for the
919 first time: version 4.2.
923 Upgraded from version 1.9711 to 1.9719.
927 Upgraded from version 1.18 to 1.1901.
931 Upgraded from version 1.12 to 1.15.
933 =item C<Unicode::Normalize>
935 Upgraded from version 1.02 to 1.03.
937 =item C<Unicode::UCD>
939 Upgraded from version 0.25 to 0.27.
941 C<charinfo()> now works on Unified CJK code points added to later versions
944 C<casefold()> has new fields returned to provide both a simpler interface
945 and previously missing information. The old fields are retained for
946 backwards compatibility. Information about Turkic-specific code points is
949 The documentation has been corrected and expanded.
953 Upgraded from version 1.04 to 1.05.
955 UNIVERSAL->import() is now deprecated.
959 Upgraded from version 0.34 to 0.39.
961 =item C<Win32API::File>
963 Upgraded from version 0.1001_01 to 0.1101.
967 Upgraded from version 0.08 to 0.10.
971 =head1 Utility Changes
977 Now looks in C<include-fixed> too, which is a recent addition to gcc's
982 No longer incorrectly treats enum values like macros (Daniel Burr).
984 Now handles C++ style constants (C<//>) properly in enums. (A patch from
985 Rainer Weikusat was used; Daniel Burr also proposed a similar fix).
989 C<LVALUE> subroutines now work under the debugger.
991 The debugger now correctly handles proxy constant subroutines, and
996 F<perlbug> now uses C<%Module::CoreList::bug_tracker> to print out upstream bug
999 Where the user names a module that their bug report is about, and we know the
1000 URL for its upstream bug tracker, provide a message to the user explaining
1001 that the core copies the CPAN version directly, and provide the URL for
1002 reporting the bug directly to upstream.
1006 Perl 5.11.0 added a new utility F<perlthanks>, which is a variant of
1007 F<perlbug>, but for sending non-bug-reports to the authors and maintainers
1008 of Perl. Getting nothing but bug reports can become a bit demoralising:
1009 we'll see if this changes things.
1013 =head1 New Documentation
1019 This contains instructions on how to build perl for the Haiku platform.
1023 This describes the new interface for pluggable Method Resolution Orders.
1027 This document, by Richard Foley, provides an introduction to the use of
1028 performance and optimization techniques which can be used with particular
1029 reference to perl programs.
1031 =item L<perlrepository>
1033 This describes how to access the perl source using the I<git> version
1038 This describes the new F<perlthanks> utility.
1042 =head1 Changes to Existing Documentation
1044 The various large F<Changes*> files (which listed every change made to perl
1045 over the last 18 years) have been removed, and replaced by a small file,
1046 also called F<Changes>, which just explains how that same information may
1047 be extracted from the git version control system.
1049 The file F<Porting/patching.pod> has been deleted, as it mainly described
1050 interacting with the old Perforce-based repository, which is now obsolete.
1051 Information still relevant has been moved to L<perlrepository>.
1053 L<perlapi>, L<perlintern>, L<perlmodlib> and L<perltoc> are now all
1054 generated at build time, rather than being shipped as part of the release.
1056 =head2 Documented -X overloading.
1058 =head2 Documented that when() treats specially most of the filetest operators
1060 =head2 Documented that DESTROY is subject to AUTOLOAD, and the related optimisations.
1062 =head2 Documented when as a syntax modifier
1064 =head2 Eliminated "Old Perl threads tutorial", which describes 5005 threads.
1066 pod/perlthrtut.pod is the same material reworked for ithreads.
1068 =head2 Removed a link to the attrs pragma, which has now been removed.
1070 =head2 update PERL_MEM_LOG in perlhack.pod
1072 =head2 Correct previous documentation: v-strings are not deprecated
1074 With version objects, we need them to use MODULE VERSION syntax. This
1075 patch removes the deprecation note.
1077 =head1 Performance Enhancements
1083 A new internal cache means that C<isa()> will often be faster.
1087 The implementation of C<C3> Method Resolution Order has been optimised -
1088 linearisation for classes with single inheritance is 40% faster. Performance
1089 for multiple inheritance is unchanged.
1093 Under C<use locale>, the locale-relevant information is now cached on
1094 read-only values, such as the list returned by C<keys %hash>. This makes
1095 operations such as C<sort keys %hash> in the scope of C<use locale> much
1100 Empty C<DESTROY> methods are no longer called.
1104 Faster sv_utf8_upgrade()
1108 Speed up keys() on empty hash
1112 =head1 Installation and Configuration Improvements
1114 =head2 F<ext/> reorganisation
1116 The layout of directories in F<ext> has been revised. Specifically, all
1117 extensions are now flat, and at the top level, with C</> in pathnames
1118 replaced by C<->, so that F<ext/Data/Dumper/> is now F<ext/Data-Dumper/>,
1119 etc. The names of the extensions as specified to F<Configure>, and as
1120 reported by C<%Config::Config> under the keys C<dynamic_ext>,
1121 C<known_extensions>, C<nonxs_ext> and C<static_ext> have not changed, and
1122 still use C</>. Hence this change will not have any affect once perl is
1123 installed. However, C<Attribute::Handlers>, C<Safe> and C<mro> have now
1124 become extensions in their own right, so if you run F<Configure> with
1125 options to specify an exact list of extensions to build, you will need to
1126 change it to account for this.
1128 For 5.11.1, it is planned that many dual-life modules will have been moved
1129 from F<lib> to F<ext>; again this will have no effect on an installed
1130 perl, but will matter if you invoke F<Configure> with a pre-canned list of
1131 extensions to build.
1133 =head2 Configuration improvements
1135 If C<vendorlib> and C<vendorarch> are the same, then they are only added to
1138 C<$Config{usedevel}> and the C-level C<PERL_USE_DEVEL> are now defined if
1139 perl is built with C<-Dusedevel>.
1141 F<Configure> will enable use of C<-fstack-protector>, to provide protection
1142 against stack-smashing attacks, if the compiler supports it.
1144 F<Configure> will now determine the correct prototypes for re-entrant
1145 functions, and for C<gconvert>, if you are using a C++ compiler rather
1148 On Unix, if you build from a tree containing a git repository, the
1149 configuration process will note the commit hash you have checked out, for
1150 display in the output of C<perl -v> and C<perl -V>. Unpushed local commits
1151 are automatically added to the list of local patches displayed by
1154 =head2 Compilation improvements
1156 As part of the flattening of F<ext>, all extensions on all platforms are
1157 built by F<make_ext.pl>. This replaces the Unix-specific
1158 F<ext/util/make_ext>, VMS-specific F<make_ext.com> and Win32-specific
1159 F<win32/buildext.pl>.
1161 =head2 Platform Specific Changes
1167 Removed F<libbsd> for AIX 5L and 6.1. Only flock() was used from F<libbsd>.
1169 Removed F<libgdbm> for AIX 5L and 6.1. The F<libgdbm> is delivered as an
1170 optional package with the AIX Toolbox. Unfortunately the 64 bit version
1173 Hints changes mean that AIX 4.2 should work again.
1177 On Cygwin we now strip the last number from the DLL. This has been the
1178 behaviour in the cygwin.com build for years. The hints files have been
1183 Support for Apollo DomainOS was removed in Perl 5.11.0
1187 The hints files now identify the correct threading libraries on FreeBSD 7
1192 We now work around a bizarre preprocessor bug in the Irix 6.5 compiler:
1193 C<cc -E -> unfortunately goes into K&R mode, but C<cc -E file.c> doesn't.
1197 Patches from the Haiku maintainers have been merged in. Perl should now
1202 Support for Atari MiNT was removed in Perl 5.11.0.
1206 Perl should now build on MirOS BSD.
1210 Hints now supports versions 5.*.
1214 Various changes from Stratus have been merged in.
1218 There is now support for Symbian S60 3.2 SDK and S60 5.0 SDK.
1222 Improved message window handling means that C<alarm> and C<kill> messages
1223 will no longer be dropped under race conditions.
1227 Reads from the in-memory temporary files of C<PerlIO::scalar> used to fail
1228 if C<$/> was set to a numeric reference (to indicate record-style reads).
1231 VMS now supports C<getgrgid>.
1233 Many improvements and cleanups have been made to the VMS file name handling
1234 and conversion code.
1236 Enabling the C<PERL_VMS_POSIX_EXIT> logical name now encodes a POSIX exit
1237 status in a VMS condition value for better interaction with GNV's bash
1238 shell and other utilities that depend on POSIX exit values. See
1239 L<perlvms/"$?"> for details.
1241 C<File::Copy> now detects Unix compatibility mode on VMS.
1245 =head1 Selected Bug Fixes
1251 C<-I> on shebang line now adds directories in front of @INC.
1252 as documented, and as does C<-I> when specified on the command-line.
1257 C<kill> is now fatal when called on non-numeric process identifiers.
1258 Previously, an 'undef' process identifier would be interpreted as a request to
1259 kill process "0", which would terminate the current process group on POSIX
1260 systems. Since process identifiers are always integers, killing a non-numeric
1261 process is now fatal.
1265 5.10.0 inadvertently disabled an optimisation, which caused a measurable
1266 performance drop in list assignment, such as is often used to assign
1267 function parameters from C<@_>. The optimisation has been re-instated, and
1268 the performance regression fixed.
1272 Fixed memory leak on C<while (1) { map 1, 1 }> [RT #53038].
1276 Some potential coredumps in PerlIO fixed [RT #57322,54828].
1280 The debugger now works with lvalue subroutines.
1284 The debugger's C<m> command was broken on modules that defined constants
1289 C<crypt()> and string complement could return tainted values for untainted
1290 arguments [RT #59998].
1294 The C<-i>I<.suffix> command-line switch now recreates the file using
1295 restricted permissions, before changing its mode to match the original
1296 file. This eliminates a potential race condition [RT #60904].
1300 On some UNIX systems, the value in C<$?> would not have the top bit set
1301 (C<$? & 128>) even if the child core dumped.
1305 Under some circumstances, C<$^R> could incorrectly become undefined
1310 (XS) In various hash functions, passing a pre-computed hash to when the
1311 key is UTF-8 might result in an incorrect lookup.
1315 (XS) Including F<XSUB.h> before F<perl.h> gave a compile-time error
1320 C<< $object->isa('Foo') >> would report false if the package C<Foo> didn't
1321 exist, even if the object's C<@ISA> contained C<Foo>.
1325 Various bugs in the new-to 5.10.0 mro code, triggered by manipulating
1326 C<@ISA>, have been found and fixed.
1330 Bitwise operations on references could crash the interpreter, e.g.
1331 C<$x=\$y; $x |= "foo"> [RT #54956].
1335 Patterns including alternation might be sensitive to the internal UTF-8
1336 representation, e.g.
1338 my $byte = chr(192);
1339 my $utf8 = chr(192); utf8::upgrade($utf8);
1340 $utf8 =~ /$byte|X}/i; # failed in 5.10.0
1344 Within UTF8-encoded Perl source files (i.e. where C<use utf8> is in
1345 effect), double-quoted literal strings could be corrupted where a C<\xNN>,
1346 C<\0NNN> or C<\N{}> is followed by a literal character with ordinal value
1347 greater than 255 [RT #59908].
1351 C<B::Deparse> failed to correctly deparse various constructs:
1352 C<readpipe STRING> [RT #62428], C<CORE::require(STRING)> [RT #62488],
1353 C<sub foo(_)> [RT #62484].
1357 Using C<setpgrp()> with no arguments could corrupt the perl stack.
1361 The block form of C<eval> is now specifically trappable by C<Safe> and
1362 C<ops>. Previously it was erroneously treated like string C<eval>.
1366 In 5.10.0, the two characters C<[~> were sometimes parsed as the smart
1367 match operator (C<~~>) [RT #63854].
1371 In 5.10.0, the C<*> quantifier in patterns was sometimes treated as
1372 C<{0,32767}> [RT #60034, #60464]. For example, this match would fail:
1374 ("ab" x 32768) =~ /^(ab)*$/
1378 C<shmget> was limited to a 32 bit segment size on a 64 bit OS [RT #63924].
1382 Using C<next> or C<last> to exit a C<given> block no longer produces a
1383 spurious warning like the following:
1385 Exiting given via last at foo.pl line 123
1389 On Windows, C<'.\foo'> and C<'..\foo'> were treated differently than
1390 C<'./foo'> and C<'../foo'> by C<do> and C<require> [RT #63492].
1394 Assigning a format to a glob could corrupt the format; e.g.:
1396 *bar=*foo{FORMAT}; # foo format now bad
1400 Attempting to coerce a typeglob to a string or number could cause an
1401 assertion failure. The correct error message is now generated,
1402 C<Can't coerce GLOB to I<$type>>.
1406 Under C<use filetest 'access'>, C<-x> was using the wrong access mode. This
1407 has been fixed [RT #49003].
1411 C<length> on a tied scalar that returned a Unicode value would not be
1412 correct the first time. This has been fixed.
1416 Using an array C<tie> inside in array C<tie> could SEGV. This has been
1421 A race condition inside C<PerlIOStdio_close()> has been identified and
1422 fixed. This used to cause various threading issues, including SEGVs.
1426 In C<unpack>, the use of C<()> groups in scalar context was internally
1427 placing a list on the interpreter's stack, which manifested in various
1428 ways, including SEGVs. This is now fixed [RT #50256].
1432 Magic was called twice in C<substr>, C<\&$x>, C<tie $x, $m> and C<chop>.
1433 These have all been fixed.
1437 A 5.10.0 optimisation to clear the temporary stack within the implicit
1438 loop of C<s///ge> has been reverted, as it turned out to be the cause of
1439 obscure bugs in seemingly unrelated parts of the interpreter [commit
1444 The line numbers for warnings inside C<elsif> are now correct.
1448 The C<..> operator now works correctly with ranges whose ends are at or
1449 close to the values of the smallest and largest integers.
1453 C<binmode STDIN, ':raw'> could lead to segmentation faults on some platforms.
1454 This has been fixed [RT #54828].
1458 An off-by-one error meant that C<index $str, ...> was effectively being
1459 executed as C<index "$str\0", ...>. This has been fixed [RT #53746].
1463 Various leaks associated with named captures in regexes have been fixed
1468 A weak reference to a hash would leak. This was affecting C<DBI>
1473 Using (?|) in a regex could cause a segfault [RT #59734].
1477 Use of a UTF-8 C<tr//> within a closure could cause a segfault [RT #61520].
1481 Calling C<sv_chop()> or otherwise upgrading an SV could result in an
1482 unaligned 64-bit access on the SPARC architecture [RT #60574].
1486 In the 5.10.0 release, C<inc_version_list> would incorrectly list
1487 C<5.10.*> after C<5.8.*>; this affected the C<@INC> search order
1492 In 5.10.0, C<pack "a*", $tainted_value> returned a non-tainted value
1497 In 5.10.0, C<printf> and C<sprintf> could produce the fatal error
1498 C<panic: utf8_mg_pos_cache_update> when printing UTF-8 strings
1503 In the 5.10.0 release, a dynamically created C<AUTOLOAD> method might be
1504 missed (method cache issue) [RT #60220,60232].
1508 In the 5.10.0 release, a combination of C<use feature> and C<//ee> could
1509 cause a memory leak [RT #63110].
1513 C<-C> on the shebang (C<#!>) line is once more permitted if it is also
1514 specified on the command line. C<-C> on the shebang line used to be a
1515 silent no-op I<if> it was not also on the command line, so perl 5.10.0
1516 disallowed it, which broke some scripts. Now perl checks whether it is
1517 also on the command line and only dies if it is not [RT #67880].
1521 In 5.10.0, certain types of re-entrant regular expression could crash,
1522 or cause the following assertion failure [RT #60508]:
1524 Assertion rx->sublen >= (s - rx->subbeg) + i failed
1528 =head1 New or Changed Diagnostics
1532 =item C<panic: sv_chop %s>
1534 This new fatal error occurs when the C routine C<Perl_sv_chop()> was
1535 passed a position that is not within the scalar's string buffer. This
1536 could be caused by buggy XS code, and at this point recovery is not
1539 =item C<Can't locate package %s for the parents of %s>
1541 This warning has been removed. In general, it only got produced in
1542 conjunction with other warnings, and removing it allowed an ISA lookup
1543 optimisation to be added.
1545 =item C<v-string in use/require is non-portable>
1547 This warning has been removed.
1549 =item C<Deep recursion on subroutine "%s">
1551 It is now possible to change the depth threshold for this warning from the
1552 default of 100, by recompiling the F<perl> binary, setting the C
1553 pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value.
1557 =head1 Changed Internals
1563 The J.R.R. Tolkien quotes at the head of C source file have been checked and
1564 proper citations added, thanks to a patch from Tom Christiansen.
1568 C<vcroak()> now accepts a null first argument. In addition, a full audit
1569 was made of the "not NULL" compiler annotations, and those for several
1570 other internal functions were corrected.
1574 New macros C<dSAVEDERRNO>, C<dSAVE_ERRNO>, C<SAVE_ERRNO>, C<RESTORE_ERRNO>
1575 have been added to formalise the temporary saving of the C<errno>
1580 The function C<Perl_sv_insert_flags> has been added to augment
1585 The function C<Perl_newSV_type(type)> has been added, equivalent to
1586 C<Perl_newSV()> followed by C<Perl_sv_upgrade(type)>.
1590 The function C<Perl_newSVpvn_flags()> has been added, equivalent to
1591 C<Perl_newSVpvn()> and then performing the action relevant to the flag.
1593 Two flag bits are currently supported.
1599 This will call C<SvUTF8_on()> for you. (Note that this does not convert an
1600 sequence of ISO 8859-1 characters to UTF-8). A wrapper, C<newSVpvn_utf8()>
1601 is available for this.
1605 Call C<sv_2mortal()> on the new SV.
1609 There is also a wrapper that takes constant strings, C<newSVpvs_flags()>.
1613 The function C<Perl_croak_xs_usage> has been added as a wrapper to
1618 The functions C<PerlIO_find_layer> and C<PerlIO_list_alloc> are now
1623 C<PL_na> has been exterminated from the core code, replaced by local STRLEN
1624 temporaries, or C<*_nolen()> calls. Either approach is faster than C<PL_na>,
1625 which is a pointer deference into the interpreter structure under ithreads,
1626 and a global variable otherwise.
1630 C<Perl_mg_free()> used to leave freed memory accessible via SvMAGIC() on
1631 the scalar. It now updates the linked list to remove each piece of magic
1636 Under ithreads, the regex in C<PL_reg_curpm> is now reference counted. This
1637 eliminates a lot of hackish workarounds to cope with it not being reference
1642 C<Perl_mg_magical()> would sometimes incorrectly turn on C<SvRMAGICAL()>.
1643 This has been fixed.
1647 The I<public> IV and NV flags are now not set if the string value has
1648 trailing "garbage". This behaviour is consistent with not setting the
1649 public IV or NV flags if the value is out of range for the type.
1653 SV allocation tracing has been added to the diagnostics enabled by C<-Dm>.
1654 The tracing can alternatively output via the C<PERL_MEM_LOG> mechanism, if
1655 that was enabled when the F<perl> binary was compiled.
1659 Uses of C<Nullav>, C<Nullcv>, C<Nullhv>, C<Nullop>, C<Nullsv> etc have been
1660 replaced by C<NULL> in the core code, and non-dual-life modules, as C<NULL>
1661 is clearer to those unfamiliar with the core code.
1665 A macro C<MUTABLE_PTR(p)> has been added, which on (non-pedantic) gcc will
1666 not cast away C<const>, returning a C<void *>. Macros C<MUTABLE_SV(av)>,
1667 C<MUTABLE_SV(cv)> etc build on this, casting to C<AV *> etc without
1668 casting away C<const>. This allows proper compile-time auditing of
1669 C<const> correctness in the core, and helped picked up some errors (now
1674 Macros C<mPUSHs()> and C<mXPUSHs()> have been added, for pushing SVs on the
1675 stack and mortalizing them.
1679 Use of the private structure C<mro_meta> has changed slightly. Nothing
1680 outside the core should be accessing this directly anyway.
1684 A new tool, F<Porting/expand-macro.pl> has been added, that allows you
1685 to view how a C preprocessor macro would be expanded when compiled.
1686 This is handy when trying to decode the macro hell that is the perl
1693 Many modules updated from CPAN incorporate new tests.
1695 Several tests that have the potential to hang forever if they fail now
1696 incorporate a "watchdog" functionality that will kill them after a timeout,
1697 which helps ensure that C<make test> and C<make test_harness> run to
1698 completion automatically. (Jerry Hedden).
1700 Some core-specific tests have been added:
1704 =item t/comp/retainedlines.t
1706 Check that the debugger can retain source lines from C<eval>.
1708 =item t/io/perlio_fail.t
1710 Check that bad layers fail.
1712 =item t/io/perlio_leaks.t
1714 Check that PerlIO layers are not leaking.
1716 =item t/io/perlio_open.t
1718 Check that certain special forms of open work.
1722 General PerlIO tests.
1726 Check that there is no unexpected interaction between the internal types
1727 C<PVBM> and C<PVGV>.
1729 =item t/mro/package_aliases.t
1731 Check that mro works properly in the presence of aliased packages.
1735 Tests for C<dbmopen> and C<dbmclose>.
1737 =item t/op/index_thr.t
1739 Tests for the interaction of C<index> and threads.
1741 =item t/op/pat_thr.t
1743 Tests for the interaction of esoteric patterns and threads.
1747 Test that C<qr> doesn't leak.
1749 =item t/op/reg_email_thr.t
1751 Tests for the interaction of regex recursion and threads.
1753 =item t/op/regexp_qr_embed_thr.t
1755 Tests for the interaction of patterns with embedded C<qr//> and threads.
1757 =item t/op/regexp_unicode_prop.t
1759 Tests for Unicode properties in regular expressions.
1761 =item t/op/regexp_unicode_prop_thr.t
1763 Tests for the interaction of Unicode properties and threads.
1765 =item t/op/reg_nc_tie.t
1767 Test the tied methods of C<Tie::Hash::NamedCapture>.
1769 =item t/op/reg_posixcc.t
1771 Check that POSIX character classes behave consistently.
1775 Check that exportable C<re> functions in F<universal.c> work.
1777 =item t/op/setpgrpstack.t
1779 Check that C<setpgrp> works.
1781 =item t/op/substr_thr.t
1783 Tests for the interaction of C<substr> and threads.
1785 =item t/op/upgrade.t
1787 Check that upgrading and assigning scalars works.
1789 =item t/uni/lex_utf8.t
1791 Check that Unicode in the lexer works.
1795 Check that Unicode and C<tie> work.
1799 =head1 Known Problems
1801 This is a list of some significant unfixed bugs, which are regressions
1802 from either 5.10.0 or 5.8.x.
1808 C<List::Util::first> misbehaves in the presence of a lexical C<$_>
1809 (typically introduced by C<my $_> or implicitly by C<given>). The variable
1810 which gets set for each iteration is the package variable C<$_>, not the
1811 lexical C<$_> [RT #67694].
1813 A similar issue may occur in other modules that provide functions which
1814 take a block as their first argument, like
1816 foo { ... $_ ...} list
1820 The C<charnames> pragma may generate a run-time error when a regex is
1821 interpolated [RT #56444]:
1823 use charnames ':full';
1824 my $r1 = qr/\N{THAI CHARACTER SARA I}/;
1825 "foo" =~ $r1; # okay
1826 "foo" =~ /$r1+/; # runtime error
1828 A workaround is to generate the character outside of the regex:
1830 my $a = "\N{THAI CHARACTER SARA I}";
1835 Some regexes may run much more slowly when run in a child thread compared
1836 with the thread the pattern was compiled into [RT #55600].
1842 The following items are now deprecated.
1848 C<Switch> is buggy and should be avoided. From perl 5.11.0 onwards, it is
1849 intended that any use of the core version of this module will emit a
1850 warning, and that the module will eventually be removed from the core
1851 (probably in perl 5.14.0). See L<perlsyn/"Switch statements"> for its
1856 C<suidperl> has been removed. It used to provide a mechanism to
1857 emulate setuid permission bits on systems that don't support it properly.
1861 Deprecate assignment to $[
1865 Remove attrs, which has been deprecated since 1999/10/02.
1869 Deprecate use of the attribute :locked on subroutines.
1873 Deprecate using "locked" with the attributes pragma.
1877 Deprecate using "unique" with the attributes pragma.
1881 warn if ++ or -- are unable to change the value because it's beyond the limit of representation
1883 This uses a new warnings category: "imprecision".
1887 Make lc/uc/lcfirst/ucfirst warn when passed undef.
1891 Show constant in "Useless use of a constant in void context"
1895 Make the new warning report undef constants as undef
1899 Add a new warning, "Prototype after '%s'"
1903 Tweak the "Illegal character in prototype" warning so it's more precise when reporting illegal characters after _
1907 Unintented interpolation of $\ in regex
1911 Make overflow warnings in gmtime/localtime only occur when warnings are on
1915 Improve mro merging error messages.
1917 They are now very similar to those produced by Algorithm::C3.
1921 Amelioration of the error message "Unrecognized character %s in column %d"
1923 Changes the error message to "Unrecognized character %s; marked by <--
1924 HERE after %s<-- HERE near column %d". This should make it a little
1925 simpler to spot and correct the suspicious character.
1929 Explicitely point to $. when it causes an uninitialized warning for ranges in scalar context
1933 =head1 Acknowledgements
1935 Some of the work in this release was funded by a TPF grant.
1937 Nicholas Clark officially retired from maintenance pumpking duty at the
1938 end of 2008; however in reality he has put much effort in since then to
1939 help get 5.10.1 into a fit state to be released, including writing a
1940 considerable chunk of this perldelta.
1942 Steffen Mueller and David Golden in particular helped getting CPAN modules
1943 polished and synchronised with their in-core equivalents.
1945 Craig Berry was tireless in getting maint to run under VMS, no matter how
1946 many times we broke it for him.
1948 The other core committers contributed most of the changes, and applied most
1949 of the patches sent in by the hundreds of contributors listed in F<AUTHORS>.
1951 Much of the work of categorizing changes in this perldelta file was contributed
1952 by the following porters using changelogger.bestpractical.com:
1954 Nicholas Clark, leon, shawn, alexm, rjbs, rafl, Pedro Melo, brunorc,
1955 anonymous, ☄, Tom Hukins, anonymous, Jesse, dagolden, Moritz Onken,
1956 Mark Fowler, chorny, anonymous, tmtm
1958 Finally, thanks to Larry Wall, without whom none of this would be
1961 =head1 Reporting Bugs
1963 If you find what you think is a bug, you might check the articles
1964 recently posted to the comp.lang.perl.misc newsgroup and the perl
1965 bug database at http://rt.perl.org/perlbug/ . There may also be
1966 information at http://www.perl.org/ , the Perl Home Page.
1968 If you believe you have an unreported bug, please run the B<perlbug>
1969 program included with your release. Be sure to trim your bug down
1970 to a tiny but sufficient test case. Your bug report, along with the
1971 output of C<perl -V>, will be sent off to perlbug@perl.org to be
1972 analysed by the Perl porting team.
1974 If the bug you are reporting has security implications, which make it
1975 inappropriate to send to a publicly archived mailing list, then please send
1976 it to perl5-security-report@perl.org. This points to a closed subscription
1977 unarchived mailing list, which includes all the core committers, who be able
1978 to help assess the impact of issues, figure out a resolution, and help
1979 co-ordinate the release of patches to mitigate or fix the problem across all
1980 platforms on which Perl is supported. Please only use this address for
1981 security issues in the Perl core, not for modules independently
1982 distributed on CPAN.
1986 The F<Changes> file for an explanation of how to view exhaustive details
1989 The F<INSTALL> file for how to build Perl.
1991 The F<README> file for general stuff.
1993 The F<Artistic> and F<Copying> files for copyright information.
2000 The following changes are a filtered list of changes which weren't backported
2001 to 5.10.1. They were run through changelogger.bestpractical.com and triaged
2002 by a set of Perl 5 Porters. Changes to blead after 5945e41e have not yet
2003 been triaged or integrated.
2005 The following changes need to be
2007 1) deleted if they don't merit inclusion
2011 2) lightly copyedited and integrated into the perldelta above. Unfortunately, many of our
2012 commit messages are somewhat terse and require a bit more help to turn into something readable
2019 =head2 Move the reg_stringify logic to Perl_sv_2pv_flags
2021 =head2 mg_copy ought to take an I32
2023 =head2 Perl_store_cop_label() isn't meant to be part of the public API.
2025 =head2 Perl_gv_fetchmethod{,_autoload,_flags} are actually never* called with a non-NULL stash.
2026 So change the parameter to NN.
2029 =head2 Promote Perl_setdefout() to the public API.
2031 =head2 Add get_cvs() as a shortcut for STR_WITH_LEN() and Perl_get_cvn_flags()
2033 =head2 In Perl_newCONSTSUB(), sv should not be NULL.
2035 =head2 GvUNIQUE* have been defined as 0 since 2005/06/30 - high time to remove them.
2037 =head2 invert and rename PERL_MEM_LOG_STDERR to PERL_MEM_LOG_NOIMPL
2039 Most users who want PERL_MEM_LOG want the default implementation,
2040 give it to them. Users providing their own implementation can
2041 obtain current behavior by adding -DPERL_MEM_LOG_NOIMPL.
2042 Frankly, the average user probably wants _ENV by default too.
2044 =head2 simplify PERL_MEM_LOG
2046 This combines multiple environment variable reads into 1,
2047 where it looks for values like "2mst"
2048 -2 leading digits are atoi()d to get FD
2049 -m memory logging please
2051 -t timestamp those please.
2053 Combining these reduces overhead such that it seemed
2054 worthwhile to drop all the ifdefs. TBD whether this works
2055 in the environment that drove the original tradeoffs.
2057 If it isnt enough, Id be tempted by a global static ptr,
2058 and on 1st use, is read, seen 0, a lock is taken, and getenvar
2059 run to populate it, unlocked, proceed. This would remove
2060 iterative overheads.
2062 =head2 Add a parameter "destructing" to Gv_AMupdate()
2064 This boolean parameter indicates if the function has been called
2065 to update the overload magic table while looking up the DESTROY
2066 method. In this case, it's probably best to avoid croaking if
2067 those tables could not be updated (for example due to a method
2068 that could not be loaded.)
2070 =head2 Modify the return value of Gv_AMupdate to indicate a compilation error
2072 This way we'll restore most of the performance on object desctruction
2073 lost by the previous commit
2076 =head2 local $SIG{FOO} = sub {...}; sets signal handler to SIG_DFL
2078 Re: [perl #60360] [PATCH] UPDATED: local $SIG{FOO} = sub {...}; sets signal handler to SIG_DFL
2079 Message-ID: <20081112234504.GI2062@tytlal.topaz.cx>
2081 Updated patch to retain source compatibility.
2083 Plus using the correct PERL_ARGS_ASSERT_SAVE_HELEM_FLAGS
2084 macro and running make regen.
2086 =head2 Respecting inc_version_list while processing PERL_VENDORLIB_STEM
2088 Respecting inc_version_list while processing PERL_VENDORLIB_STEM
2089 From: "Mandalemula, Rajesh" <Rajesh.Mandalemula@deshaw.com>
2091 =head2 Change PL_debug behaviour
2094 String eval lines are now saved whenever
2095 a subroutine is defined, even if the eval'd string has subsequent
2096 syntax errors. This allows the debugger to single step into these
2100 =head2 Tied filehandles now have an additional method EOF which provides the EOF type
2102 =head2 Perl is now smarter about adding a -I dir to the beginning or end of @INC
2104 =head2 On scope end, delete localized array elements that should not exist anymore, so that the array recovers its previous length. Honour EXISTS and DELETE for tied arrays.
2106 =head2 When a glob is deleted, mark its sub as ANON.
2108 =head2 Require a space or a newline after a "#line XXX" directive
2110 =head2 Forbid using "foreach" as an attribute
2112 (like all other control flow statements)
2115 =head2 Unregister signal handlers before destroying my_perl
2117 If the signal handler runs after perl_destruct() has been called, it
2118 will get an invalid (or NULL) my_perl when it asks for the
2119 thread-specific interpreter struct. This patch resets the signal
2120 handler for any signal previously handled by PL_csighandlerp to SIG_DFL
2121 before calling perl_destruct().
2123 =head2 Perl_magic_clearsig() needs to remove magic, else delete $SIG{INT} returns undef
2125 Perl_magic_clearsig() needs to remove magic, else delete $SIG{INT} returns undef
2126 instead of the now-removed INT handler.
2128 =head2 [perl #66452] TMPDIR not honored when opening an anonymous temporary file
2130 [perl #66452] TMPDIR not honored when opening an anonymous temporary file
2132 =head2 The attached patch to perlio.c fixes the problem of errno getting set.
2134 While I am firmly in the school of "do not look at $! except immediately
2135 after a failure", I also agree that spuriously setting it is messy. But
2136 there is just no way of knowing where your errno might have been.
2138 The problem was that PerlIO_fast_gets() (and other nearby similar
2139 capability-checking PerlIO routines) set the errno (and it was being
2140 called a lot, from sv_gets()). I think setting the errno here was
2141 a mistake: checking for "can has FOO" should not set external state,
2142 such as the errno. The patch removes that errno trashing from all those
2145 =head2 Trim all trailing / from "." in @INC when filling %INC
2147 This fixes bug #66942 : as a / was left in the directory name,
2148 $INC{"Foo.pm"} for a file loaded from the current directory
2149 was given the incorrect value "/Foo.pm".
2151 =head2 Don't enqueue pending signals during global destruction
2153 Global destruction is not signal-safe. PL_psig_pend may already
2154 be gone when the signal handler is called (with destruct_level > 0).
2155 NULL it before freeing it to prevent a race condition.
2157 =head2 Eliminate struct regexp_allocated and xpvio_allocated.
2159 Calculate memory allocation using regexp and XPVIO, and the offset of the first
2160 real structure member. This avoids tripping over alignment differences between
2161 X* and x*_allocated, because x*_allocated doesn't have a double in it.
2166 =head2 [perl #47047] Use of inherited AUTOLOAD for non-method is deprecated
2168 =head2 Remove the definitions of Null(), Nullch, Nullfp, Nullsv and PL_na when code is within the perl source tree
2170 =head2 Replace our assert-which-can-be-caught-by-eval with the real deal from the standard C library.
2172 =head2 Tweak Perl_sv_upgrade() so that references can upgrade to SVt_PV
2174 =head2 Eliminate prelen from struct regexp.
2176 =head2 Change Perl_av_iter_p() to return IV* rather than I32* (which means
2178 =head2 Reorder the external regexp flags to get RXf_PMf_STD_PMMOD into the
2180 lowest 4 bits (which saves a shift), and the "flags indicating special
2181 patterns" into contiguous bits. This makes everything a little tidier,
2182 and saves 88 bytes (woohoo!) of object file with -Os on x86 FreeBSD.
2185 =head2 Re-implement the SvOOK() hack to store the offset as a BER encoded number in the part of the PVX that is being released.
2187 fit, as chopping off 1 byte gives just enough space for recording a
2188 delta of up to 127). This allows SvOOK() to co-exist with SvIOK_on(),
2189 which means all the calls to SvOOK_off() [with the possibility of a
2190 call to sv_backoff()] in SvIOK_on() can be removed. This ought to make
2191 a lot of straight line code a little bit simpler.
2192 OOK()d scalars can now be SVt_PV, as the IVX isn't needed.
2194 =head2 Abolish wraplen from struct regexp. We're already storing it in SvCUR.
2196 =head2 Make Perl_pregcomp() use SvUTF8() of the pattern, rather than the flag bit in pmflags, to decide whether the pattern is UTF-8.
2198 =head2 Abolish RXf_UTF8. Store the UTF-8-ness of the pattern with SvUTF8().
2200 =head2 In struct regexp move the member paren_names to the IV union.
2202 =head2 Make REGEXP a type distinct from SV. (Much like AV, CV, GV, HV).
2204 =head2 Allow sv_setsv_flags() to copy SVt_REGEXP much like it copies SVt_FORMAT - the just string buffer.
2207 =head2 Correct a long-standing ithreads reference counting anonamly
2209 The reference count only needs "doubling" when the scalar is pushed onto
2210 PL_regex_padav for the second time.
2213 =head2 In PL_regexp_padav, store regexps via real references, rather than hiding them within IVs.
2215 We can do this now that they are real SV pointers.
2217 =head2 With regexps stored as real RVs, we can eliminate SvREPADTMP().
2219 =head2 REGEXPs are now stored directly in PL_regex_padav, rather than indirectly via RVs.
2221 =head2 Remove code that protected pp_qr against REGEXPs going away during global destruction whilst they were stored via true references in PL_regex_padav.
2223 =head2 Remove PM_GETRE_SAFE and PM_SETRE_SAFE as nothing uses them.
2225 =head2 Note the U8 sized space created by removing -P, and check that it is now an illegal command line flag.
2227 =head2 Pack the recycled pad offsets into an SV at PL_regex_pad[0].
2229 =head2 Re-order so that the !SvOK() case is last (which should be rare)
2231 =head2 Extend PUSHFORMAT() to take a second parameter to set retop, to save NULLing it and then reassigning.
2233 =head2 Split struct block_sub into struct block_sub and struct block_format.
2235 Split struct block_sub into struct block_sub and struct block_format.
2236 (CXt_SUB and CXt_FORMAT were using some comon members, but some members
2237 were only for one or the other.)
2239 =head2 Change the wantarray result from caller from IV to bool for the SCALAR/ARRAY case.
2241 This doesn't contradict the documentation, as there isn't any. Oops.
2244 =head2 Give G_VOID, G_SCALAR and G_ARRAY the same numeric values as OPf_WANT_VOID, OPf_WANT_SCALAR and OPf_WANT_LIST.
2247 =head2 Squeeze the context type down to 4 bits, and move the private flags to fit within the next 4 bits.
2250 =head2 In struct block change blku_type from U8 to U16, and the "spare" U8 to U16, with the lockstep changes in struct subst.
2252 struct block_sub, and instead store it in the U16 in struct block.
2255 =head2 In struct block_eval, eliminate old_in_eval and old_op_type by storing the data in blk_u16.
2258 =head2 The layout for struct block_loop under ithreads can be simplified.
2260 Instead of wedging the pad offset into a void* iterdata, and always
2261 storing PL_comppad even when it isn't used, instead do this:
2263 PAD *oldcomppad; /* Also used for the GV, if targoffset is 0 */
2264 /* This is also accesible via cx->blk_loop.my_op->op_targ */
2265 PADOFFSET targoffset;
2267 and store the GV pointer in oldcompad. Pointers to pointers seems
2268 cleaner. This also allows us to eliminate the flag bit CXp_PADVAR.
2271 =head2 In XS_PerlIO_get_layers() take advantage of the implementation of
2273 In XS_PerlIO_get_layers() take advantage of the implementation of
2274 PerlIO_get_layers(), by co-opting the new SVs it creates, rather than
2278 =head2 Micro-optimise the order of the context types. [Because I can :-)]
2280 =head2 [patch] optimize OP_IS_(FILETEST|SOCKET) macros
2282 =head2 Eliminate ck_lengthconst.
2284 =head2 Chainsaw DEBUG_S out, as suggested by Vincent Pit.
2286 =head2 Unsupported private API functions are now declared "static" to prevent leakage to the public API
2288 =head2 Perl_cv_ckproto() is not part of the public API, and not used anywhere. It has been removed
2290 =head2 Remove all the 5005threads specific mutex macros, which are now vestigial.
2292 =head2 Do not honor TMPDIR for anonymous temporary files when tainting
2294 Use a default of /tmp on Unixes when TMPDIR is unset or empty, or
2295 when creation of a temporary file in it fails
2297 =head2 Add a pluggable hook in op_free()