3 perl5110delta - what is new for perl v5.11.0
7 This document describes differences between the 5.10.0 release and
8 the 5.11.0 development release.
10 =head1 Incompatible Changes
12 =head2 In @INC, move ARCHLIB and PRIVLIB after the current version's site_perl and vendor_perl.
15 =head2 Switch statement changes
17 The handling of complex expressions by the C<given>/C<when> switch
18 statement has been enhanced. There are two new cases where C<when> now
19 interprets its argument as a boolean, instead of an expression to be used
24 =item flip-flop operators
26 The C<..> and C<...> flip-flop operators are now evaluated in boolean
27 context, following their usual semantics; see L<perlop/"Range Operators">.
29 Note that, as in perl 5.10.0, C<when (1..10)> will not work to test
30 whether a given value is an integer between 1 and 10; you should use
31 C<when ([1..10])> instead (note the array reference).
33 However, contrary to 5.10.0, evaluating the flip-flop operators in boolean
34 context ensures it can now be useful in a C<when()>, notably for
35 implementing bistable conditions, like in:
37 when (/^=begin/ .. /^=end/) {
41 =item defined-or operator
43 A compound expression involving the defined-or operator, as in
44 C<when (expr1 // expr2)>, will be treated as boolean if the first
45 expression is boolean. (This just extends the existing rule that applies
46 to the regular or operator, as in C<when (expr1 || expr2)>.)
50 The next section details more changes brought to the semantics to
51 the smart match operator, that naturally also modify the behaviour
52 of the switch statements where smart matching is implicitly used.
54 =head2 Smart match changes
56 =head3 Changes to type-based dispatch
58 The smart match operator C<~~> is no longer commutative. The behaviour of
59 a smart match now depends primarily on the type of its right hand
60 argument. Moreover, its semantics have been adjusted for greater
61 consistency or usefulness in several cases. While the general backwards
62 compatibility is maintained, several changes must be noted:
68 Code references with an empty prototype are no longer treated specially.
69 They are passed an argument like the other code references (even if they
74 C<%hash ~~ sub {}> and C<@array ~~ sub {}> now test that the subroutine
75 returns a true value for each key of the hash (or element of the
76 array), instead of passing the whole hash or array as a reference to
81 Due to the commutativity breakage, code references are no longer
82 treated specially when appearing on the left of the C<~~> operator,
83 but like any vulgar scalar.
87 C<undef ~~ %hash> is always false (since C<undef> can't be a key in a
88 hash). No implicit conversion to C<""> is done (as was the case in perl
93 C<$scalar ~~ @array> now always distributes the smart match across the
94 elements of the array. It's true if one element in @array verifies
95 C<$scalar ~~ $element>. This is a generalization of the old behaviour
96 that tested whether the array contained the scalar.
100 The full dispatch table for the smart match operator is given in
101 L<perlsyn/"Smart matching in detail">.
103 =head3 Smart match and overloading
105 According to the rule of dispatch based on the rightmost argument type,
106 when an object overloading C<~~> appears on the right side of the
107 operator, the overload routine will always be called (with a 3rd argument
108 set to a true value, see L<overload>.) However, when the object will
109 appear on the left, the overload routine will be called only when the
110 rightmost argument is a simple scalar. This way distributivity of smart match
111 across arrays is not broken, as well as the other behaviours with complex
112 types (coderefs, hashes, regexes). Thus, writers of overloading routines
113 for smart match mostly need to worry only with comparing against a scalar,
114 and possibly with stringification overloading; the other common cases
115 will be automatically handled consistently.
117 C<~~> will now refuse to work on objects that do not overload it (in order
118 to avoid relying on the object's underlying structure). (However, if the
119 object overloads the stringification or the numification operators, and
120 if overload fallback is active, it will be used instead, as usual.)
122 =head2 Labels can't be keywords
124 Labels used as targets for the C<goto>, C<last>, C<next> or C<redo>
125 statements cannot be keywords anymore. This restriction will prevent
126 potential confusion between the C<goto LABEL> and C<goto EXPR> syntaxes:
127 for example, a statement like C<goto print> would jump to a label whose
128 name would be the return value of print(), (usually 1), instead of a
129 label named C<print>. Moreover, the other control flow statements
130 would just ignore any keyword passed to them as a label name. Since
131 such labels cannot be defined anymore, this kind of error will be
134 =head2 Other incompatible changes
140 The semantics of C<use feature :5.10*> have changed slightly.
141 See L<"Modules and Pragmata"> for more information.
145 It is now a run-time error to use the smart match operator C<~~>
146 with an object that has no overload defined for it. (This way
147 C<~~> will not break encapsulation by matching against the
148 object's internal representation as a reference.)
152 The version control system used for the development of the perl
153 interpreter has been switched from Perforce to git. This is mainly an
154 internal issue that only affects people actively working on the perl core;
155 but it may have minor external visibility, for example in some of details
156 of the output of C<perl -V>. See L<perlrepository> for more information.
160 The internal structure of the C<ext/> directory in the perl source has
161 been reorganised. In general, a module C<Foo::Bar> whose source was
162 stored under F<ext/Foo/Bar/> is now located under F<ext/Foo-Bar/>. Also,
163 some modules have been moved from F<lib/> to F<ext/>. This is purely a
164 source tarball change, and should make no difference to the compilation or
165 installation of perl, unless you have a very customised build process that
166 explicitly relies on this structure, or which hard-codes the C<nonxs_ext>
167 F<Configure> parameter. Specifically, this change does not by default
168 alter the location of any files in the final installation.
172 As part of the C<Test::Harness> 2.x to 3.x upgrade, the experimental
173 C<Test::Harness::Straps> module has been removed.
174 See L</"Updated Modules"> for more details.
178 As part of the C<ExtUtils::MakeMaker> upgrade, the
179 C<ExtUtils::MakeMaker::bytes> and C<ExtUtils::MakeMaker::vmsish> modules
180 have been removed from this distribution.
184 C<Module::CoreList> no longer contains the C<%:patchlevel> hash.
188 This one is actually a change introduced in 5.10.0, but it was missed
189 from that release's perldelta, so it is mentioned here instead.
191 A bugfix related to the handling of the C</m> modifier and C<qr> resulted
192 in a change of behaviour between 5.8.x and 5.10.0:
194 # matches in 5.8.x, doesn't match in 5.10.0
195 $re = qr/^bar/; "foo\nbar" =~ /$re/m;
199 C<length undef> now returns undef.
203 =head1 Core Enhancements
205 =head2 Unicode Character Database 5.1.0
207 The copy of the Unicode Character Database included in Perl 5.10.1 has
208 been updated to 5.1.0 from 5.0.0. See
209 L<http://www.unicode.org/versions/Unicode5.1.0/#Notable_Changes> for the
212 =head2 A proper interface for pluggable Method Resolution Orders
214 As of Perl 5.10.1 there is a new interface for plugging and using method
215 resolution orders other than the default (linear depth first search).
216 The C3 method resolution order added in 5.10.0 has been re-implemented as
217 a plugin, without changing its Perl-space interface. See L<perlmroapi> for
220 =head2 The C<overloading> pragma
222 This pragma allows you to lexically disable or enable overloading
223 for some or all operations. (Yuval Kogman)
225 =head2 C<\N> regex escape
227 A new regex escape has been added, C<\N>. It will match any character that
228 is not a newline, independently from the presence or absence of the single
229 line match modifier C</s>. (If C<\N> is followed by an opening brace and
230 by a letter, perl will still assume that a Unicode character name is
231 coming, so compatibility is preserved.) (Rafael Garcia-Suarez)
233 =head2 Implicit strictures
235 Using the C<use VERSION> syntax with a version number greater or equal
236 to 5.11.0 will also lexically enable strictures just like C<use strict>
237 would do (in addition to enabling features.) So, the following:
246 =head2 Parallel tests
248 The core distribution can now run its regression tests in parallel on
249 Unix-like platforms. Instead of running C<make test>, set C<TEST_JOBS> in
250 your environment to the number of tests to run in parallel, and run
251 C<make test_harness>. On a Bourne-like shell, this can be done as
253 TEST_JOBS=3 make test_harness # Run 3 tests in parallel
255 An environment variable is used, rather than parallel make itself, because
256 L<TAP::Harness> needs to be able to schedule individual non-conflicting test
257 scripts itself, and there is no standard interface to C<make> utilities to
258 interact with their job schedulers.
260 Note that currently some test scripts may fail when run in parallel (most
261 notably C<ext/IO/t/io_dir.t>). If necessary run just the failing scripts
262 again sequentially and see if the failures go away.
264 =head2 The C<...> operator
266 A new operator, C<...>, nicknamed the Yada Yada operator, has been added.
267 It is intended to mark placeholder code, that is not yet implemented.
268 See L<perlop/"Yada Yada Operator">. (chromatic)
270 =head2 DTrace support
272 Some support for DTrace has been added. See "DTrace support" in F<INSTALL>.
274 =head2 Support for C<configure_requires> in CPAN module metadata
276 Both C<CPAN> and C<CPANPLUS> now support the C<configure_requires> keyword
277 in the C<META.yml> metadata file included in most recent CPAN distributions.
278 This allows distribution authors to specify configuration prerequisites that
279 must be installed before running F<Makefile.PL> or F<Build.PL>.
281 See the documentation for C<ExtUtils::MakeMaker> or C<Module::Build> for more
282 on how to specify C<configure_requires> when creating a distribution for CPAN.
284 =head2 The C<each> function can now operate on arrays
286 =head2 Perl's core time-related functions are now Y2038 compliand
288 =head2 The variable C<$,> may now be tied
290 =head2 // now behaves like || in when clauses
292 =head2 You can now set C<-W> from the C<PERL5OPT> environment varialbe
296 =head1 Modules and Pragmata
298 =head2 New Modules and Pragmata
304 This is a new lexically-scoped alternative for the C<Fatal> module.
305 The bundled version is 2.06_01. Note that in this release, using a string
306 eval when C<autodie> is in effect can cause the autodie behaviour to leak
307 into the surrounding scope. See L<autodie/"BUGS"> for more details.
309 =item C<Compress::Raw::Bzip2>
311 This has been added to the core (version 2.020).
315 This pragma establishes an ISA relationship with base classes at compile
316 time. It provides the key feature of C<base> without the feature creep.
318 =item C<Parse::CPAN::Meta>
320 This has been added to the core (version 1.39).
324 =head2 Pragmata Changes
330 See L</"The C<overloading> pragma"> above.
334 Upgraded from version 0.08 to 0.09.
338 Upgraded from version 1.02 to 1.03.
342 Upgraded from version 2.13 to 2.14. See L<parent> for a replacement.
346 Upgraded from version 0.22 to 0.23.
350 Upgraded from version 0.22 to 0.23.
354 Upgraded from version 0.22 to 0.23.
358 Upgraded from version 1.06 to 1.07.
360 The Unicode F<NameAliases.txt> database file has been added. This has the
361 effect of adding some extra C<\N> character names that formerly wouldn't
362 have been recognised; for example, C<"\N{LATIN CAPITAL LETTER GHA}">.
366 Upgraded from version 1.13 to 1.17.
370 The meaning of the C<:5.10> and C<:5.10.X> feature bundles has
371 changed slightly. The last component, if any (i.e. C<X>) is simply ignored.
372 This is predicated on the assumption that new features will not, in
373 general, be added to maintenance releases. So C<:5.10> and C<:5.10.X>
374 have identical effect. This is a change to the behaviour documented for
379 Upgraded from version 2.13 to 2.14 (this was just a version bump; there
380 were no functional changes).
384 Upgraded from version 0.5565 to 0.62.
388 Upgraded from version 1.06 to 1.07.
392 Upgraded from version 1.06 to 1.07.
396 See L</"The C<overloading> pragma"> above.
400 Upgraded from version 0.74 to 0.77.
404 =head2 Updated Modules
408 =item C<Archive::Extract>
410 Upgraded from version 0.24 to 0.34.
412 =item C<Archive::Tar>
414 Upgraded from version 1.38 to 1.52.
416 =item C<Attribute::Handlers>
418 Upgraded from version 0.79 to 0.85.
422 Upgraded from version 5.63 to 5.68.
426 Upgraded from version 1.05 to 1.06.
430 Upgraded from version 1.17 to 1.22.
434 Upgraded from version 1.05 to 1.11.
438 Upgraded from version 0.83 to 0.89.
442 Upgraded from version 1.09 to 1.11.
446 Upgraded from version 1.01 to 1.02.
450 Upgraded from version 1.10 to 1.11.
454 Upgraded from version 1.08 to 1.11.
456 L<Carp> now includes all the necessary code to function. Previously, it
457 used to be a lightweight placeholder that loaded the actual code from
458 C<Carp::Heavy> on demand. C<Carp::Heavy> is now a simple, empty module
459 kept for backwards compatibility for programs that used to pre-load it.
464 Upgraded from version 3.29 to 3.43.
465 (also includes the "default_value for popup_menu()" fix from 3.45).
467 =item C<Compress::Zlib>
469 Upgraded from version 2.008 to 2.020.
473 Upgraded from version 1.9205 to 1.9402. C<CPAN::FTP> has a local fix to
474 stop it being too verbose on download failure.
478 Upgraded from version 0.84 to 0.88.
480 =item C<CPANPLUS::Dist::Build>
482 Upgraded from version 0.06_02 to 0.36.
486 Upgraded from version 3.25_01 to 3.30.
488 =item C<Data::Dumper>
490 Upgraded from version 2.121_14 to 2.124.
494 Upgraded from version 1.01 to 1.02.
498 Upgraded from version 1.816_1 to 1.820.
500 =item C<Devel::PPPort>
502 Upgraded from version 3.13 to 3.19.
506 Upgraded from version 2.36_01 to 2.39.
510 Upgraded from version 5.45 to 5.47.
514 Upgraded from version 1.01 to 1.03.
518 Upgraded from version 1.12 to 1.13.
522 Upgraded from version 1.08 to 1.10.
526 Upgraded from version 2.23 to 2.35.
530 Upgraded from version 1.10 to 1.11.
534 Upgraded from version 5.62 to 5.63.
536 =item C<ExtUtils::CBuilder>
538 Upgraded from version 0.21 to 0.2602.
540 =item C<ExtUtils::Command>
542 Upgraded from version 1.13 to 1.16.
544 =item C<ExtUtils::Constant>
546 Upgraded from 0.20 to 0.22. (Note that neither of these versions are
549 =item C<ExtUtils::Embed>
551 Upgraded from version 1.27 to 1.28.
553 =item C<ExtUtils::Install>
555 Upgraded from version 1.44 to 1.54.
557 =item C<ExtUtils::MakeMaker>
559 Upgraded from version 6.42 to 6.55_02.
561 Note that C<ExtUtils::MakeMaker::bytes> and C<ExtUtils::MakeMaker::vmsish>
562 have been removed from this distribution.
564 =item C<ExtUtils::Manifest>
566 Upgraded from version 1.51_01 to 1.56.
568 =item C<ExtUtils::ParseXS>
570 Upgraded from version 2.18_02 to 2.2002.
574 Upgraded from version 1.05 to 2.06_01. See also the new pragma C<autodie>.
576 =item C<File::Basename>
578 Upgraded from version 2.76 to 2.77.
580 =item C<File::Compare>
582 Upgraded from version 1.1005 to 1.1006.
586 Upgraded from version 2.11 to 2.14.
588 File::Copy now always return 0 (not "") on failure.
592 Upgraded from version 0.14 to 0.20.
596 Upgraded from version 1.12 to 1.14.
600 Upgraded from version 2.04 to 2.07_03.
604 Upgraded from version 3.2501 to 3.30.
608 Upgraded from version 1.00 to 1.01.
610 Added -X overloading, -M, -C and -A.
614 Upgraded from version 0.18 to 0.22.
618 Upgraded from version 1.07 to 1.08.
622 Upgraded from version 2.01 to 2.02.
624 =item C<Filter::Simple>
626 Upgraded from version 0.82 to 0.84.
628 =item C<Filter::Util::Call>
630 Upgraded from version 1.07 to 1.08.
634 Upgraded from version 1.49 to 1.50.
638 Upgraded from version 1.08 to 1.09.
640 =item C<Getopt::Long>
642 Upgraded from version 2.37 to 2.38.
644 =item C<Hash::Util::FieldHash>
646 Upgraded from version 1.03 to 1.04. This fixes a memory leak.
648 =item C<I18N::Collate>
650 Upgraded from version 1.00 to 1.01.
654 Upgraded from version 1.23_01 to 1.25.
656 This makes non-blocking mode work on Windows in C<IO::Socket::INET>
659 =item C<IO::Compress::*>
661 Upgraded from version 2.008 to 2.020.
665 Upgraded from version 1.06 to 1.07.
669 Upgraded from version 1.27 to 1.28.
673 Upgraded from version 1.30_01 to 1.31.
677 Upgraded from version 1.07 to 1.09.
681 Upgraded from version 0.40_1 to 0.46.
685 Upgraded from version 1.02 to 1.04.
689 Upgraded from version 1.05 to 2.01.
693 Upgraded from version 0.5565 to 0.62.
697 Upgraded from version 1.19 to 1.21.
699 =item C<Locale::MakeText>
701 Upgraded from version 1.12 to 1.13.
703 =item C<Log::Message>
705 Upgraded from version 0.01 to 0.02.
707 =item C<Math::BigFloat>
709 Upgraded from version 1.59 to 1.60.
711 =item C<Math::BigInt>
713 Upgraded from version 1.88 to 1.89.
715 =item C<Math::BigInt::FastCalc>
717 Upgraded from version 0.16 to 0.19.
719 =item C<Math::BigRat>
721 Upgraded from version 0.21 to 0.22.
723 =item C<Math::Complex>
725 Upgraded from version 1.37 to 1.56.
729 Upgraded from version 1.04 to 1.20.
733 Upgraded from version 1.01_02 to 1.01_03 (just a minor documentation
736 =item C<Module::Build>
738 Upgraded from version 0.2808_01 to 0.34_02.
740 =item C<Module::CoreList>
742 Upgraded from version 2.13 to 2.18. This release no longer contains the
743 C<%Module::CoreList::patchlevel> hash.
745 =item C<Module::Load>
747 Upgraded from version 0.12 to 0.16.
749 =item C<Module::Load::Conditional>
751 Upgraded from version 0.22 to 0.30.
753 =item C<Module::Loaded>
755 Upgraded from version 0.01 to 0.02.
757 =item C<Module::Pluggable>
759 Upgraded from version 3.6 to 3.9.
763 Upgraded from version 1.07 to 1.08.
767 Upgraded from version 2.33 to 2.36.
771 Upgraded from version 0.60_01 to 0.64.
773 =item C<Object::Accessor>
775 Upgraded from version 0.32 to 0.34.
779 Upgraded from version 1.03 to 1.04.
781 =item C<Package::Constants>
783 Upgraded from version 0.01 to 0.02.
787 Upgraded from version 1.04 to 1.06.
791 Upgraded from version 0.04 to 0.07.
795 Upgraded from version 2.16 to 2.22.
799 Upgraded from version 1.35 to 1.37.
803 Upgrade from version 3.14_02 to 3.15.
807 Upgraded from version 3.05 to 3.07.
811 Upgraded from version 3.08 to 3.13.
815 Upgraded from version 1.13 to 1.17.
819 Upgraded from 2.12 to 2.18.
821 =item C<Scalar::Util>
823 Upgraded from version 1.19 to 1.21.
827 Upgraded from 1.01 to 1.02.
831 Upgraded from 1.11 to 1.17.
835 Upgraded from 1.80 to 1.82.
839 Upgraded from 2.18 to 2.20.
843 Upgraded from version 2.13 to 2.14. Please see L</Deprecations>.
847 Upgraded from version 1.06 to 1.07.
851 Upgraded from version 0.22 to 0.27.
853 =item C<Term::ANSIColor>
855 Upgraded from version 1.12 to 2.01.
857 =item C<Term::ReadLine>
859 Upgraded from version 1.03 to 1.04.
863 Upgraded from version 0.18 to 0.20.
865 =item C<Test::Harness>
867 Upgraded from version 2.64 to 3.17.
869 Note that one side-effect of the 2.x to 3.x upgrade is that the
870 experimental C<Test::Harness::Straps> module (and its supporting
871 C<Assert>, C<Iterator>, C<Point> and C<Results> modules) have been
872 removed. If you still need this, then they are available in the
873 (unmaintained) C<Test-Harness-Straps> distribution on CPAN.
875 =item C<Test::Simple>
877 Upgraded from version 0.72 to 0.92.
879 =item C<Text::ParseWords>
881 Upgraded from version 3.26 to 3.27.
885 Upgraded from version 2007.1117 to 2009.0305.
889 Upgraded from version 2006.1117 to 2009.0305.
891 =item C<Thread::Queue>
893 Upgraded from version 2.00 to 2.11.
895 =item C<Thread::Semaphore>
897 Upgraded from version 2.01 to 2.09.
901 Upgraded from version 1.67 to 1.73.
903 =item C<threads::shared>
905 Upgraded from version 1.14 to 1.29.
907 =item C<Tie::RefHash>
909 Upgraded from version 1.37 to 1.38.
911 =item C<Tie::StdHandle>
913 This has documentation changes, and has been assigned a version for the
914 first time: version 4.2.
918 Upgraded from version 1.9711 to 1.9719.
922 Upgraded from version 1.18 to 1.1901.
926 Upgraded from version 1.12 to 1.15.
928 =item C<Unicode::Normalize>
930 Upgraded from version 1.02 to 1.03.
932 =item C<Unicode::UCD>
934 Upgraded from version 0.25 to 0.27.
936 C<charinfo()> now works on Unified CJK code points added to later versions
939 C<casefold()> has new fields returned to provide both a simpler interface
940 and previously missing information. The old fields are retained for
941 backwards compatibility. Information about Turkic-specific code points is
944 The documentation has been corrected and expanded.
948 Upgraded from version 1.04 to 1.05.
950 UNIVERSAL->import() is now deprecated.
955 Upgraded from version 0.34 to 0.39.
957 =item C<Win32API::File>
959 Upgraded from version 0.1001_01 to 0.1101.
963 Upgraded from version 0.08 to 0.10.
967 =head1 Utility Changes
973 Now looks in C<include-fixed> too, which is a recent addition to gcc's
978 No longer incorrectly treats enum values like macros (Daniel Burr).
980 Now handles C++ style constants (C<//>) properly in enums. (A patch from
981 Rainer Weikusat was used; Daniel Burr also proposed a similar fix).
985 C<LVALUE> subroutines now work under the debugger.
987 The debugger now correctly handles proxy constant subroutines, and
993 Perlbug now uses %Module::CoreList::bug_tracker to print out upstream bug tracker URLs.
995 Where the user names a module that their bug report is about, and we know the
996 URL for its upstream bug tracker, provide a message to the user explaining
997 that the core copies the CPAN version directly, and provide the URL for
998 reporting the bug directly to upstream.
1002 Perl 5.10.1 added a new utility F<perlthanks>, which is a variant of
1003 F<perlbug>, but for sending non-bug-reports to the authors and maintainers
1004 of Perl. Getting nothing but bug reports can become a bit demoralising:
1005 we'll see if this changes things.
1009 =head1 New Documentation
1015 This contains instructions on how to build perl for the Haiku platform.
1019 This describes the new interface for pluggable Method Resolution Orders.
1023 This document, by Richard Foley, provides an introduction to the use of
1024 performance and optimization techniques which can be used with particular
1025 reference to perl programs.
1027 =item L<perlrepository>
1029 This describes how to access the perl source using the I<git> version
1034 This describes the new F<perlthanks> utility.
1038 =head1 Changes to Existing Documentation
1040 The various large C<Changes*> files (which listed every change made to perl
1041 over the last 18 years) have been removed, and replaced by a small file,
1042 also called C<Changes>, which just explains how that same information may
1043 be extracted from the git version control system.
1045 The file F<Porting/patching.pod> has been deleted, as it mainly described
1046 interacting with the old Perforce-based repository, which is now obsolete.
1047 Information still relevant has been moved to L<perlrepository>.
1049 L<perlapi>, L<perlintern>, L<perlmodlib> and L<perltoc> are now all
1050 generated at build time, rather than being shipped as part of the release.
1052 =head2 Documented -X overloading.
1054 =head2 Documented that when() treats specially most of the filetest operators
1056 =head2 Documented that DESTROY is subject to AUTOLOAD, and the related optimisations.
1058 =head2 Documented when as a syntax modifier
1060 =head2 Eliminated "Old Perl threads tutorial", which describes 5005 threads.
1062 pod/perlthrtut.pod is the same material reworked for ithreads.
1064 =head2 Removed a link to the attrs pragma, which has now been removed.
1066 =head2 update PERL_MEM_LOG in perlhack.pod
1068 =head2 Correct previous documentation: v-strings are not deprecated
1070 With version objects, we need them to use MODULE VERSION syntax. This
1071 patch removes the deprecation note.
1074 =head1 Performance Enhancements
1080 A new internal cache means that C<isa()> will often be faster.
1084 Under C<use locale>, the locale-relevant information is now cached on
1085 read-only values, such as the list returned by C<keys %hash>. This makes
1086 operations such as C<sort keys %hash> in the scope of C<use locale> much
1091 Empty C<DESTROY> methods are no longer called.
1095 Faster sv_utf8_upgrade()
1099 Speed up keys() on empty hash
1103 =head1 Installation and Configuration Improvements
1105 =head2 F<ext/> reorganisation
1107 The layout of directories in F<ext> has been revised. Specifically, all
1108 extensions are now flat, and at the top level, with C</> in pathnames
1109 replaced by C<->, so that F<ext/Data/Dumper/> is now F<ext/Data-Dumper/>,
1110 etc. The names of the extensions as specified to F<Configure>, and as
1111 reported by C<%Config::Config> under the keys C<dynamic_ext>,
1112 C<known_extensions>, C<nonxs_ext> and C<static_ext> have not changed, and
1113 still use C</>. Hence this change will not have any affect once perl is
1114 installed. However, C<Attribute::Handlers>, C<Safe> and C<mro> have now
1115 become extensions in their own right, so if you run F<Configure> with
1116 options to specify an exact list of extensions to build, you will need to
1117 change it to account for this.
1119 For 5.10.2, it is planned that many dual-life modules will have been moved
1120 from F<lib> to F<ext>; again this will have no effect on an installed
1121 perl, but will matter if you invoke F<Configure> with a pre-canned list of
1122 extensions to build.
1124 =head2 Configuration improvements
1126 If C<vendorlib> and C<vendorarch> are the same, then they are only added to
1129 C<$Config{usedevel}> and the C-level C<PERL_USE_DEVEL> are now defined if
1130 perl is built with C<-Dusedevel>.
1132 F<Configure> will enable use of C<-fstack-protector>, to provide protection
1133 against stack-smashing attacks, if the compiler supports it.
1135 F<Configure> will now determine the correct prototypes for re-entrant
1136 functions, and for C<gconvert>, if you are using a C++ compiler rather
1139 On Unix, if you build from a tree containing a git repository, the
1140 configuration process will note the commit hash you have checked out, for
1141 display in the output of C<perl -v> and C<perl -V>. Unpushed local commits
1142 are automatically added to the list of local patches displayed by
1145 =head2 Compilation improvements
1147 As part of the flattening of F<ext>, all extensions on all platforms are
1148 built by F<make_ext.pl>. This replaces the Unix-specific
1149 F<ext/util/make_ext>, VMS-specific F<make_ext.com> and Win32-specific
1150 F<win32/buildext.pl>.
1152 =head2 Platform Specific Changes
1158 Removed F<libbsd> for AIX 5L and 6.1. Only flock() was used from F<libbsd>.
1160 Removed F<libgdbm> for AIX 5L and 6.1. The F<libgdbm> is delivered as an
1161 optional package with the AIX Toolbox. Unfortunately the 64 bit version
1164 Hints changes mean that AIX 4.2 should work again.
1168 On Cygwin we now strip the last number from the DLL. This has been the
1169 behaviour in the cygwin.com build for years. The hints files have been
1174 The hints files now identify the correct threading libraries on FreeBSD 7
1179 We now work around a bizarre preprocessor bug in the Irix 6.5 compiler:
1180 C<cc -E -> unfortunately goes into K&R mode, but C<cc -E file.c> doesn't.
1184 Patches from the Haiku maintainers have been merged in. Perl should now
1189 Perl should now build on MirOS BSD.
1193 Hints now supports versions 5.*.
1197 Various changes from Stratus have been merged in.
1201 There is now support for Symbian S60 3.2 SDK and S60 5.0 SDK.
1205 Improved message window handling means that C<alarm> and C<kill> messages
1206 will no longer be dropped under race conditions.
1210 Reads from the in-memory temporary files of C<PerlIO::scalar> used to fail
1211 if C<$/> was set to a numeric reference (to indicate record-style reads).
1214 VMS now supports C<getgrgid>.
1216 Many improvements and cleanups have been made to the VMS file name handling
1217 and conversion code.
1219 Enabling the C<PERL_VMS_POSIX_EXIT> logical name now encodes a POSIX exit
1220 status in a VMS condition value for better interaction with GNV's bash
1221 shell and other utilities that depend on POSIX exit values. See
1222 L<perlvms/"$?"> for details.
1224 File::Copy now detects Unix compatibility mode on VMS.
1228 =head1 Selected Bug Fixes
1234 =item C<-I> on shebang line now adds directories in front of @INC.
1235 as documented, and as does C<-I> when specified on the command-line.
1240 * C<kill> is now fatal when called on non-numeric process identifiers.
1241 Previously, an 'undef' process identifier would be interpreted as a request to
1242 kill process "0", which would terminate the current process group on POSIX
1243 systems. Since process identifiers are always integers, killing a non-numeric
1244 process is now fatal.
1248 5.10.0 inadvertently disabled an optimisation, which caused a measurable
1249 performance drop in list assignment, such as is often used to assign
1250 function parameters from C<@_>. The optimisation has been re-instated, and
1251 the performance regression fixed.
1255 Fixed memory leak on C<while (1) { map 1, 1 }> [RT #53038].
1259 Some potential coredumps in PerlIO fixed [RT #57322,54828].
1263 The debugger now works with lvalue subroutines.
1267 The debugger's C<m> command was broken on modules that defined constants
1272 C<crypt()> and string complement could return tainted values for untainted
1273 arguments [RT #59998].
1277 The C<-i.suffix> command-line switch now recreates the file using
1278 restricted permissions, before changing its mode to match the original
1279 file. This eliminates a potential race condition [RT #60904].
1283 On some UNIX systems, the value in C<$?> would not have the top bit set
1284 (C<$? & 128>) even if the child core dumped.
1288 Under some circumstances, $^R could incorrectly become undefined
1293 (XS) In various hash functions, passing a pre-computed hash to when the
1294 key is UTF-8 might result in an incorrect lookup.
1298 (XS) Including F<XSUB.h> before F<perl.h> gave a compile-time error
1303 C<< $object->isa('Foo') >> would report false if the package C<Foo> didn't
1304 exist, even if the object's C<@ISA> contained C<Foo>.
1308 Various bugs in the new-to 5.10.0 mro code, triggered by manipulating
1309 C<@ISA>, have been found and fixed.
1313 Bitwise operations on references could crash the interpreter, e.g.
1314 C<$x=\$y; $x |= "foo"> [RT #54956].
1318 Patterns including alternation might be sensitive to the internal UTF-8
1319 representation, e.g.
1321 my $byte = chr(192);
1322 my $utf8 = chr(192); utf8::upgrade($utf8);
1323 $utf8 =~ /$byte|X}/i; # failed in 5.10.0
1327 Within UTF8-encoded Perl source files (i.e. where C<use utf8> is in
1328 effect), double-quoted literal strings could be corrupted where a C<\xNN>,
1329 C<\0NNN> or C<\N{}> is followed by a literal character with ordinal value
1330 greater than 255 [RT #59908].
1334 C<B::Deparse> failed to correctly deparse various constructs:
1335 C<readpipe STRING> [RT #62428], C<CORE::require(STRING)> [RT #62488],
1336 C<sub foo(_)> [RT #62484].
1340 Using C<setpgrp()> with no arguments could corrupt the perl stack.
1344 The block form of C<eval> is now specifically trappable by C<Safe> and
1345 C<ops>. Previously it was erroneously treated like string C<eval>.
1349 In 5.10.0, the two characters C<[~> were sometimes parsed as the smart
1350 match operator (C<~~>) [RT #63854].
1354 In 5.10.0, the C<*> quantifier in patterns was sometimes treated as
1355 C<{0,32767}> [RT #60034, #60464]. For example, this match would fail:
1357 ("ab" x 32768) =~ /^(ab)*$/
1361 C<shmget> was limited to a 32 bit segment size on a 64 bit OS [RT #63924].
1365 Using C<next> or C<last> to exit a C<given> block no longer produces a
1366 spurious warning like the following:
1368 Exiting given via last at foo.pl line 123
1372 On Windows, C<'.\foo'> and C<'..\foo'> were treated differently than
1373 C<'./foo'> and C<'../foo'> by C<do> and C<require> [RT #63492].
1377 Assigning a format to a glob could corrupt the format; e.g.:
1379 *bar=*foo{FORMAT}; # foo format now bad
1383 Attempting to coerce a typeglob to a string or number could cause an
1384 assertion failure. The correct error message is now generated,
1385 C<Can't coerce GLOB to I<$type>>.
1389 Under C<use filetest 'access'>, C<-x> was using the wrong access mode. This
1390 has been fixed [RT #49003].
1394 C<length> on a tied scalar that returned a Unicode value would not be
1395 correct the first time. This has been fixed.
1399 Using an array C<tie> inside in array C<tie> could SEGV. This has been
1404 A race condition inside C<PerlIOStdio_close()> has been identified and
1405 fixed. This used to cause various threading issues, including SEGVs.
1409 In C<unpack>, the use of C<()> groups in scalar context was internally
1410 placing a list on the interpreter's stack, which manifested in various
1411 ways, including SEGVs. This is now fixed [RT #50256].
1415 Magic was called twice in C<substr>, C<\&$x>, C<tie $x, $m> and C<chop>.
1416 These have all been fixed.
1420 A 5.10.0 optimisation to clear the temporary stack within the implicit
1421 loop of C<s///ge> has been reverted, as it turned out to be the cause of
1422 obscure bugs in seemingly unrelated parts of the interpreter [commit
1427 The line numbers for warnings inside C<elsif> are now correct.
1431 The C<..> operator now works correctly with ranges whose ends are at or
1432 close to the values of the smallest and largest integers.
1436 C<binmode STDIN, ':raw'> could lead to segmentation faults on some platforms.
1437 This has been fixed [RT #54828].
1441 An off-by-one error meant that C<index $str, ...> was effectively being
1442 executed as C<index "$str\0", ...>. This has been fixed [RT #53746].
1446 Various leaks associated with named captures in regexes have been fixed
1451 A weak reference to a hash would leak. This was affecting C<DBI>
1456 Using (?|) in a regex could cause a segfault [RT #59734].
1460 Use of a UTF-8 C<tr//> within a closure could cause a segfault [RT #61520].
1464 Calling C<sv_chop()> or otherwise upgrading an SV could result in an
1465 unaligned 64-bit access on the SPARC architecture [RT #60574].
1469 In the 5.10.0 release, C<inc_version_list> would incorrectly list
1470 C<5.10.*> after C<5.8.*>; this affected the C<@INC> search order
1475 In 5.10.0, C<pack "a*", $tainted_value> returned a non-tainted value
1480 In 5.10.0, C<printf> and C<sprintf> could produce the fatal error
1481 C<panic: utf8_mg_pos_cache_update> when printing UTF-8 strings
1486 In the 5.10.0 release, a dynamically created C<AUTOLOAD> method might be
1487 missed (method cache issue) [RT #60220,60232].
1491 In the 5.10.0 release, a combination of C<use feature> and C<//ee> could
1492 cause a memory leak [RT #63110].
1496 C<-C> on the shebang (C<#!>) line is once more permitted if it is also
1497 specified on the command line. C<-C> on the shebang line used to be a
1498 silent no-op I<if> it was not also on the command line, so perl 5.10.0
1499 disallowed it, which broke some scripts. Now perl checks whether it is
1500 also on the command line and only dies if it is not [RT #67880].
1504 In 5.10.0, certain types of re-entrant regular expression could crash,
1505 or cause the following assertion failure [RT #60508]:
1507 Assertion rx->sublen >= (s - rx->subbeg) + i failed
1511 =head1 New or Changed Diagnostics
1515 =item C<panic: sv_chop %s>
1517 This new fatal error occurs when the C routine C<Perl_sv_chop()> was
1518 passed a position that is not within the scalar's string buffer. This
1519 could be caused by buggy XS code, and at this point recovery is not
1522 =item C<Can't locate package %s for the parents of %s>
1524 This warning has been removed. In general, it only got produced in
1525 conjunction with other warnings, and removing it allowed an ISA lookup
1526 optimisation to be added.
1528 =item C<v-string in use/require is non-portable>
1530 This warning has been removed.
1532 =item C<Deep recursion on subroutine "%s">
1534 It is now possible to change the depth threshold for this warning from the
1535 default of 100, by recompiling the F<perl> binary, setting the C
1536 pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value.
1540 =head1 Changed Internals
1546 The J.R.R. Tolkien quotes at the head of C source file have been checked and
1547 proper citations added, thanks to a patch from Tom Christiansen.
1551 C<vcroak()> now accepts a null first argument. In addition, a full audit
1552 was made of the "not NULL" compiler annotations, and those for several
1553 other internal functions were corrected.
1557 New macros C<dSAVEDERRNO>, C<dSAVE_ERRNO>, C<SAVE_ERRNO>, C<RESTORE_ERRNO>
1558 have been added to formalise the temporary saving of the C<errno>
1563 The function C<Perl_sv_insert_flags> has been added to augment
1568 The function C<Perl_newSV_type(type)> has been added, equivalent to
1569 C<Perl_newSV()> followed by C<Perl_sv_upgrade(type)>.
1573 The function C<Perl_newSVpvn_flags()> has been added, equivalent to
1574 C<Perl_newSVpvn()> and then performing the action relevant to the flag.
1576 Two flag bits are currently supported.
1582 This will call C<SvUTF8_on()> for you. (Note that this does not convert an
1583 sequence of ISO 8859-1 characters to UTF-8). A wrapper, C<newSVpvn_utf8()>
1584 is available for this.
1588 Call C<sv_2mortal()> on the new SV.
1592 There is also a wrapper that takes constant strings, C<newSVpvs_flags()>.
1596 The function C<Perl_croak_xs_usage> has been added as a wrapper to
1601 The functions C<PerlIO_find_layer> and C<PerlIO_list_alloc> are now
1606 C<PL_na> has been exterminated from the core code, replaced by local STRLEN
1607 temporaries, or C<*_nolen()> calls. Either approach is faster than C<PL_na>,
1608 which is a pointer deference into the interpreter structure under ithreads,
1609 and a global variable otherwise.
1613 C<Perl_mg_free()> used to leave freed memory accessible via SvMAGIC() on
1614 the scalar. It now updates the linked list to remove each piece of magic
1619 Under ithreads, the regex in C<PL_reg_curpm> is now reference counted. This
1620 eliminates a lot of hackish workarounds to cope with it not being reference
1625 C<Perl_mg_magical()> would sometimes incorrectly turn on C<SvRMAGICAL()>.
1626 This has been fixed.
1630 The I<public> IV and NV flags are now not set if the string value has
1631 trailing "garbage". This behaviour is consistent with not setting the
1632 public IV or NV flags if the value is out of range for the type.
1636 SV allocation tracing has been added to the diagnostics enabled by C<-Dm>.
1637 The tracing can alternatively output via the C<PERL_MEM_LOG> mechanism, if
1638 that was enabled when the F<perl> binary was compiled.
1642 Uses of C<Nullav>, C<Nullcv>, C<Nullhv>, C<Nullop>, C<Nullsv> etc have been
1643 replaced by C<NULL> in the core code, and non-dual-life modules, as C<NULL>
1644 is clearer to those unfamiliar with the core code.
1648 A macro C<MUTABLE_PTR(p)> has been added, which on (non-pedantic) gcc will
1649 not cast away C<const>, returning a C<void *>. Macros C<MUTABLE_SV(av)>,
1650 C<MUTABLE_SV(cv)> etc build on this, casting to C<AV *> etc without
1651 casting away C<const>. This allows proper compile-time auditing of
1652 C<const> correctness in the core, and helped picked up some errors (now
1657 Macros C<mPUSHs()> and C<mXPUSHs()> have been added, for pushing SVs on the
1658 stack and mortalizing them.
1662 Use of the private structure C<mro_meta> has changed slightly. Nothing
1663 outside the core should be accessing this directly anyway.
1667 A new tool, C<Porting/expand-macro.pl> has been added, that allows you
1668 to view how a C preprocessor macro would be expanded when compiled.
1669 This is handy when trying to decode the macro hell that is the perl
1676 Many modules updated from CPAN incorporate new tests.
1678 Several tests that have the potential to hang forever if they fail now
1679 incorporate a "watchdog" functionality that will kill them after a timeout,
1680 which helps ensure that C<make test> and C<make test_harness> run to
1681 completion automatically. (Jerry Hedden).
1683 Some core-specific tests have been added:
1687 =item t/comp/retainedlines.t
1689 Check that the debugger can retain source lines from C<eval>.
1691 =item t/io/perlio_fail.t
1693 Check that bad layers fail.
1695 =item t/io/perlio_leaks.t
1697 Check that PerlIO layers are not leaking.
1699 =item t/io/perlio_open.t
1701 Check that certain special forms of open work.
1705 General PerlIO tests.
1709 Check that there is no unexpected interaction between the internal types
1710 C<PVBM> and C<PVGV>.
1712 =item t/mro/package_aliases.t
1714 Check that mro works properly in the presence of aliased packages.
1718 Tests for C<dbmopen> and C<dbmclose>.
1720 =item t/op/index_thr.t
1722 Tests for the interaction of C<index> and threads.
1724 =item t/op/pat_thr.t
1726 Tests for the interaction of esoteric patterns and threads.
1730 Test that C<qr> doesn't leak.
1732 =item t/op/reg_email_thr.t
1734 Tests for the interaction of regex recursion and threads.
1736 =item t/op/regexp_qr_embed_thr.t
1738 Tests for the interaction of patterns with embedded C<qr//> and threads.
1740 =item t/op/regexp_unicode_prop.t
1742 Tests for Unicode properties in regular expressions.
1744 =item t/op/regexp_unicode_prop_thr.t
1746 Tests for the interaction of Unicode properties and threads.
1748 =item t/op/reg_nc_tie.t
1750 Test the tied methods of C<Tie::Hash::NamedCapture>.
1752 =item t/op/reg_posixcc.t
1754 Check that POSIX character classes behave consistently.
1758 Check that exportable C<re> functions in F<universal.c> work.
1760 =item t/op/setpgrpstack.t
1762 Check that C<setpgrp> works.
1764 =item t/op/substr_thr.t
1766 Tests for the interaction of C<substr> and threads.
1768 =item t/op/upgrade.t
1770 Check that upgrading and assigning scalars works.
1772 =item t/uni/lex_utf8.t
1774 Check that Unicode in the lexer works.
1778 Check that Unicode and C<tie> work.
1782 =head1 Known Problems
1784 This is a list of some significant unfixed bugs, which are regressions
1785 from either 5.10.0 or 5.8.x.
1791 C<List::Util::first> misbehaves in the presence of a lexical C<$_>
1792 (typically introduced by C<my $_> or implicitly by C<given>). The variable
1793 which gets set for each iteration is the package variable C<$_>, not the
1794 lexical C<$_> [RT #67694].
1796 A similar issue may occur in other modules that provide functions which
1797 take a block as their first argument, like
1799 foo { ... $_ ...} list
1803 The C<charnames> pragma may generate a run-time error when a regex is
1804 interpolated [RT #56444]:
1806 use charnames ':full';
1807 my $r1 = qr/\N{THAI CHARACTER SARA I}/;
1808 "foo" =~ $r1; # okay
1809 "foo" =~ /$r1+/; # runtime error
1811 A workaround is to generate the character outside of the regex:
1813 my $a = "\N{THAI CHARACTER SARA I}";
1818 Some regexes may run much more slowly when run in a child thread compared
1819 with the thread the pattern was compiled into [RT #55600].
1826 The following items are now deprecated.
1832 C<Switch> is buggy and should be avoided. From perl 5.11.0 onwards, it is
1833 intended that any use of the core version of this module will emit a
1834 warning, and that the module will eventually be removed from the core
1835 (probably in perl 5.14.0). See L<perlsyn/"Switch statements"> for its
1840 C<suidperl> has been removed. It used to provide a mechanism to
1841 emulate setuid permission bits on systems that don't support it properly.
1845 Deprecate assignment to $[
1849 Remove attrs, which has been deprecated since 1999/10/02.
1853 Deprecate use of the attribute :locked on subroutines.
1857 Deprecate using "locked" with the attributes pragma.
1861 Deprecate using "unique" with the attributes pragma.
1865 warn if ++ or -- are unable to change the value because it's beyond the limit of representation
1867 This uses a new warnings category: "imprecision".
1872 Make lc/uc/lcfirst/ucfirst warn when passed undef.
1876 Show constant in "Useless use of a constant in void context"
1880 Make the new warning report undef constants as undef
1884 Add a new warning, "Prototype after '%s'"
1888 Tweak the "Illegal character in prototype" warning so it's more precise when reporting illegal characters after _
1892 Unintented interpolation of $\ in regex
1896 Make overflow warnings in gmtime/localtime only occur when warnings are on
1900 Improve mro merging error messages.
1902 They are now very similar to those produced by Algorithm::C3.
1906 Amelioration of the error message "Unrecognized character %s in column %d"
1908 Changes the error message to "Unrecognized character %s; marked by <--
1909 HERE after %s<-- HERE near column %d". This should make it a little
1910 simpler to spot and correct the suspicious character.
1914 Explicitely point to $. when it causes an uninitialized warning for ranges in scalar context
1918 =head1 Acknowledgements
1920 Some of the work in this release was funded by a TPF grant.
1922 Nicholas Clark officially retired from maintenance pumpking duty at the
1923 end of 2008; however in reality he has put much effort in since then to
1924 help get 5.10.1 into a fit state to be released, including writing a
1925 considerable chunk of this perldelta.
1927 Steffen Mueller and David Golden in particular helped getting CPAN modules
1928 polished and synchronised with their in-core equivalents.
1930 Craig Berry was tireless in getting maint to run under VMS, no matter how
1931 many times we broke it for him.
1933 The other core committers contributed most of the changes, and applied most
1934 of the patches sent in by the hundreds of contributors listed in F<AUTHORS>.
1936 Much of the work of categorizing changes in this perldelta file was contributed
1937 by the following porters using changelogger.bestpractical.com:
1939 Nicholas Clark, leon, shawn, alexm, rjbs, rafl, Pedro Melo, brunorc,
1940 anonymous, ☄, Tom Hukins, anonymous, Jesse, dagolden, Moritz Onken,
1941 Mark Fowler, chorny, anonymous, tmtm
1944 Finally, thanks to Larry Wall, without whom none of this would be
1947 =head1 Reporting Bugs
1949 If you find what you think is a bug, you might check the articles
1950 recently posted to the comp.lang.perl.misc newsgroup and the perl
1951 bug database at http://rt.perl.org/perlbug/ . There may also be
1952 information at http://www.perl.org/ , the Perl Home Page.
1954 If you believe you have an unreported bug, please run the B<perlbug>
1955 program included with your release. Be sure to trim your bug down
1956 to a tiny but sufficient test case. Your bug report, along with the
1957 output of C<perl -V>, will be sent off to perlbug@perl.org to be
1958 analysed by the Perl porting team.
1960 If the bug you are reporting has security implications, which make it
1961 inappropriate to send to a publicly archived mailing list, then please send
1962 it to perl5-security-report@perl.org. This points to a closed subscription
1963 unarchived mailing list, which includes all the core committers, who be able
1964 to help assess the impact of issues, figure out a resolution, and help
1965 co-ordinate the release of patches to mitigate or fix the problem across all
1966 platforms on which Perl is supported. Please only use this address for
1967 security issues in the Perl core, not for modules independently
1968 distributed on CPAN.
1972 The F<Changes> file for an explanation of how to view exhaustive details
1975 The F<INSTALL> file for how to build Perl.
1977 The F<README> file for general stuff.
1979 The F<Artistic> and F<Copying> files for copyright information.
1986 The following changes are a filtered list of changes which weren't backported
1987 to 5.10.1. They were run through changelogger.bestpractical.com and triaged
1988 by a set of Perl 5 Porters. Changes to blead after 5945e41e have not yet
1989 been triaged or integrated.
1991 The following changes need to be
1993 1) deleted if they don't merit inclusion
1997 2) lightly copyedited and integrated into the perldelta above. Unfortunately, many of our
1998 commit messages are somewhat terse and require a bit more help to turn into something readable
2005 =head2 Move the reg_stringify logic to Perl_sv_2pv_flags
2007 =head2 mg_copy ought to take an I32
2009 =head2 Perl_store_cop_label() isn't meant to be part of the public API.
2011 =head2 Perl_gv_fetchmethod{,_autoload,_flags} are actually never* called with a non-NULL stash.
2012 So change the parameter to NN.
2015 =head2 Promote Perl_setdefout() to the public API.
2017 =head2 Add get_cvs() as a shortcut for STR_WITH_LEN() and Perl_get_cvn_flags()
2019 =head2 In Perl_newCONSTSUB(), sv should not be NULL.
2021 =head2 GvUNIQUE* have been defined as 0 since 2005/06/30 - high time to remove them.
2023 =head2 invert and rename PERL_MEM_LOG_STDERR to PERL_MEM_LOG_NOIMPL
2025 Most users who want PERL_MEM_LOG want the default implementation,
2026 give it to them. Users providing their own implementation can
2027 obtain current behavior by adding -DPERL_MEM_LOG_NOIMPL.
2028 Frankly, the average user probably wants _ENV by default too.
2030 =head2 simplify PERL_MEM_LOG
2032 This combines multiple environment variable reads into 1,
2033 where it looks for values like "2mst"
2034 -2 leading digits are atoi()d to get FD
2035 -m memory logging please
2037 -t timestamp those please.
2039 Combining these reduces overhead such that it seemed
2040 worthwhile to drop all the ifdefs. TBD whether this works
2041 in the environment that drove the original tradeoffs.
2043 If it isnt enough, Id be tempted by a global static ptr,
2044 and on 1st use, is read, seen 0, a lock is taken, and getenvar
2045 run to populate it, unlocked, proceed. This would remove
2046 iterative overheads.
2048 =head2 Add a parameter "destructing" to Gv_AMupdate()
2050 This boolean parameter indicates if the function has been called
2051 to update the overload magic table while looking up the DESTROY
2052 method. In this case, it's probably best to avoid croaking if
2053 those tables could not be updated (for example due to a method
2054 that could not be loaded.)
2056 =head2 Modify the return value of Gv_AMupdate to indicate a compilation error
2058 This way we'll restore most of the performance on object desctruction
2059 lost by the previous commit
2062 =head2 local $SIG{FOO} = sub {...}; sets signal handler to SIG_DFL
2064 Re: [perl #60360] [PATCH] UPDATED: local $SIG{FOO} = sub {...}; sets signal handler to SIG_DFL
2065 Message-ID: <20081112234504.GI2062@tytlal.topaz.cx>
2067 Updated patch to retain source compatibility.
2069 Plus using the correct PERL_ARGS_ASSERT_SAVE_HELEM_FLAGS
2070 macro and running make regen.
2072 =head2 Respecting inc_version_list while processing PERL_VENDORLIB_STEM
2074 Respecting inc_version_list while processing PERL_VENDORLIB_STEM
2075 From: "Mandalemula, Rajesh" <Rajesh.Mandalemula@deshaw.com>
2077 =head2 Change PL_debug behaviour
2080 String eval lines are now saved whenever
2081 a subroutine is defined, even if the eval'd string has subsequent
2082 syntax errors. This allows the debugger to single step into these
2086 =head2 Tied filehandles now have an additional method EOF which provides the EOF type
2088 =head2 Perl is now smarter about adding a -I dir to the beginning or end of @INC
2090 =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.
2092 =head2 When a glob is deleted, mark its sub as ANON.
2094 =head2 Require a space or a newline after a "#line XXX" directive
2096 =head2 Forbid using "foreach" as an attribute
2098 (like all other control flow statements)
2101 =head2 Unregister signal handlers before destroying my_perl
2103 If the signal handler runs after perl_destruct() has been called, it
2104 will get an invalid (or NULL) my_perl when it asks for the
2105 thread-specific interpreter struct. This patch resets the signal
2106 handler for any signal previously handled by PL_csighandlerp to SIG_DFL
2107 before calling perl_destruct().
2109 =head2 Perl_magic_clearsig() needs to remove magic, else delete $SIG{INT} returns undef
2111 Perl_magic_clearsig() needs to remove magic, else delete $SIG{INT} returns undef
2112 instead of the now-removed INT handler.
2114 =head2 [perl #66452] TMPDIR not honored when opening an anonymous temporary file
2116 [perl #66452] TMPDIR not honored when opening an anonymous temporary file
2118 =head2 The attached patch to perlio.c fixes the problem of errno getting set.
2120 While I am firmly in the school of "do not look at $! except immediately
2121 after a failure", I also agree that spuriously setting it is messy. But
2122 there is just no way of knowing where your errno might have been.
2124 The problem was that PerlIO_fast_gets() (and other nearby similar
2125 capability-checking PerlIO routines) set the errno (and it was being
2126 called a lot, from sv_gets()). I think setting the errno here was
2127 a mistake: checking for "can has FOO" should not set external state,
2128 such as the errno. The patch removes that errno trashing from all those
2131 =head2 Trim all trailing / from "." in @INC when filling %INC
2133 This fixes bug #66942 : as a / was left in the directory name,
2134 $INC{"Foo.pm"} for a file loaded from the current directory
2135 was given the incorrect value "/Foo.pm".
2137 =head2 Don't enqueue pending signals during global destruction
2139 Global destruction is not signal-safe. PL_psig_pend may already
2140 be gone when the signal handler is called (with destruct_level > 0).
2141 NULL it before freeing it to prevent a race condition.
2143 =head2 Eliminate struct regexp_allocated and xpvio_allocated.
2145 Calculate memory allocation using regexp and XPVIO, and the offset of the first
2146 real structure member. This avoids tripping over alignment differences between
2147 X* and x*_allocated, because x*_allocated doesn't have a double in it.
2152 =head2 [perl #47047] Use of inherited AUTOLOAD for non-method is deprecated
2154 =head2 Remove the definitions of Null(), Nullch, Nullfp, Nullsv and PL_na when code is within the perl source tree
2156 =head2 Replace our assert-which-can-be-caught-by-eval with the real deal from the standard C library.
2158 =head2 Tweak Perl_sv_upgrade() so that references can upgrade to SVt_PV
2160 =head2 Eliminate prelen from struct regexp.
2162 =head2 Change Perl_av_iter_p() to return IV* rather than I32* (which means
2164 =head2 Reorder the external regexp flags to get RXf_PMf_STD_PMMOD into the
2166 lowest 4 bits (which saves a shift), and the "flags indicating special
2167 patterns" into contiguous bits. This makes everything a little tidier,
2168 and saves 88 bytes (woohoo!) of object file with -Os on x86 FreeBSD.
2171 =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.
2173 fit, as chopping off 1 byte gives just enough space for recording a
2174 delta of up to 127). This allows SvOOK() to co-exist with SvIOK_on(),
2175 which means all the calls to SvOOK_off() [with the possibility of a
2176 call to sv_backoff()] in SvIOK_on() can be removed. This ought to make
2177 a lot of straight line code a little bit simpler.
2178 OOK()d scalars can now be SVt_PV, as the IVX isn't needed.
2180 =head2 Abolish wraplen from struct regexp. We're already storing it in SvCUR.
2182 =head2 Make Perl_pregcomp() use SvUTF8() of the pattern, rather than the flag bit in pmflags, to decide whether the pattern is UTF-8.
2184 =head2 Abolish RXf_UTF8. Store the UTF-8-ness of the pattern with SvUTF8().
2186 =head2 In struct regexp move the member paren_names to the IV union.
2188 =head2 Make REGEXP a type distinct from SV. (Much like AV, CV, GV, HV).
2190 =head2 Allow sv_setsv_flags() to copy SVt_REGEXP much like it copies SVt_FORMAT - the just string buffer.
2193 =head2 Correct a long-standing ithreads reference counting anonamly
2195 The reference count only needs "doubling" when the scalar is pushed onto
2196 PL_regex_padav for the second time.
2199 =head2 In PL_regexp_padav, store regexps via real references, rather than hiding them within IVs.
2201 We can do this now that they are real SV pointers.
2203 =head2 With regexps stored as real RVs, we can eliminate SvREPADTMP().
2205 =head2 REGEXPs are now stored directly in PL_regex_padav, rather than indirectly via RVs.
2207 =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.
2209 =head2 Remove PM_GETRE_SAFE and PM_SETRE_SAFE as nothing uses them.
2211 =head2 Note the U8 sized space created by removing -P, and check that it is now an illegal command line flag.
2213 =head2 Pack the recycled pad offsets into an SV at PL_regex_pad[0].
2215 =head2 Re-order so that the !SvOK() case is last (which should be rare)
2217 =head2 Extend PUSHFORMAT() to take a second parameter to set retop, to save NULLing it and then reassigning.
2219 =head2 Split struct block_sub into struct block_sub and struct block_format.
2221 Split struct block_sub into struct block_sub and struct block_format.
2222 (CXt_SUB and CXt_FORMAT were using some comon members, but some members
2223 were only for one or the other.)
2225 =head2 Change the wantarray result from caller from IV to bool for the SCALAR/ARRAY case.
2227 This doesn't contradict the documentation, as there isn't any. Oops.
2230 =head2 Give G_VOID, G_SCALAR and G_ARRAY the same numeric values as OPf_WANT_VOID, OPf_WANT_SCALAR and OPf_WANT_LIST.
2233 =head2 Squeeze the context type down to 4 bits, and move the private flags to fit within the next 4 bits.
2236 =head2 In struct block change blku_type from U8 to U16, and the "spare" U8 to U16, with the lockstep changes in struct subst.
2238 struct block_sub, and instead store it in the U16 in struct block.
2241 =head2 In struct block_eval, eliminate old_in_eval and old_op_type by storing the data in blk_u16.
2244 =head2 The layout for struct block_loop under ithreads can be simplified.
2246 Instead of wedging the pad offset into a void* iterdata, and always
2247 storing PL_comppad even when it isn't used, instead do this:
2249 PAD *oldcomppad; /* Also used for the GV, if targoffset is 0 */
2250 /* This is also accesible via cx->blk_loop.my_op->op_targ */
2251 PADOFFSET targoffset;
2253 and store the GV pointer in oldcompad. Pointers to pointers seems
2254 cleaner. This also allows us to eliminate the flag bit CXp_PADVAR.
2257 =head2 In XS_PerlIO_get_layers() take advantage of the implementation of
2259 In XS_PerlIO_get_layers() take advantage of the implementation of
2260 PerlIO_get_layers(), by co-opting the new SVs it creates, rather than
2264 =head2 Micro-optimise the order of the context types. [Because I can :-)]
2266 =head2 [patch] optimize OP_IS_(FILETEST|SOCKET) macros
2268 =head2 Eliminate ck_lengthconst.
2270 =head2 Chainsaw DEBUG_S out, as suggested by Vincent Pit.
2272 =head2 Unsupported private API functions are now declared "static" to prevent leakage to the public API
2274 =head2 Perl_cv_ckproto() is not part of the public API, and not used anywhere. It has been removed
2276 =head2 Remove all the 5005threads specific mutex macros, which are now vestigial.
2278 =head2 Do not honor TMPDIR for anonymous temporary files when tainting
2280 Use a default of /tmp on Unixes when TMPDIR is unset or empty, or
2281 when creation of a temporary file in it fails
2283 =head2 Add a pluggable hook in op_free()