4 * changelogged up to 95544aa
5 * the mauve module will not be part of the release, so it's not changelogged
6 yet. it also added some new api functions. those aren't covered either, as they
7 might go away again in case mauve gets rolled back for 5.13.5.
11 [ this is a template for a new perldelta file. Any text flagged as
12 XXX needs to be processed before release. ]
14 perldelta - what is new for perl v5.13.5
18 This document describes differences between the 5.13.4 release and
21 If you are upgrading from an earlier release such as 5.13.3, first read
22 L<perl5134delta>, which describes differences between 5.13.3 and
27 XXX Any important notices here
29 =head1 Core Enhancements
31 XXX New core language features go here. Summarise user-visible core language
32 enhancements. Particularly prominent performance optimisations could go
33 here, but most should go in the L</Performance Enhancements> section.
35 =head2 Adjacent pairs of nextstate opcodes are now optimized away
37 Previously, in code such as
39 use constant DEBUG => 0;
46 the ops for C<warn if DEBUG;> would be folded to a C<null> op (C<ex-const>), but
47 the C<nextstate> op would remain, resulting in a runtime op dispatch of
48 C<nextstate>, C<nextstate>, ...
50 The execution of a sequence of C<nexstate> ops is indistinguishable from just
51 the last C<nextstate> op, so teach the peephole optimiser to eliminate the first
52 of a pair of C<nextstate> ops. (Except where the first carries a label, as
53 labels mustn't be eliminated by the optimiser, and label usage isn't
54 conclusively known at compile time.)
56 =head2 API function to parse statements
58 The C<parse_fullstmt> function has been added to allow parsing of a single
59 complete Perl statement. See L<perlapi> for details.
61 =head2 API functions for accessing the runtime hinthash
63 A new C API for introspecting the hinthash C<%^H> at runtime has been added. See
64 C<cop_hints_2hv>, C<cop_hints_fetchpvn>, C<cop_hints_fetchpvs>, and
65 C<cop_hints_fetchsv> in L<perlapi> for details.
67 =head2 C interface to C<caller()>
69 The C<caller_cx> function has been added as an XSUB-writer's equivalent of
70 C<caller()>. See L<perlapi> for details.
74 XXX Any security-related notices go here. In particular, any security
75 vulnerabilities closed should be noted here rather than in the
76 L</Selected Bug Fixes> section.
78 [ List each security issue as a =head2 entry ]
80 =head1 Incompatible Changes
82 =head2 Magic Variables Outside the Main Package
84 In previous versions of perl, magic variables like C<$!>, C<%SIG>, etc. would
85 'leak' into other packages. So C<%foo::SIG> could be used to access signals,
86 C<${"foo::!"}> (with strict mode off) to access C's C<errno>, etc.
88 This was a bug, or an 'unintentional' feature, which caused various ill
89 effects, such as signal handlers being wiped when modules were loaded, etc.
91 This has been fixed (or the feature has been removed, depending on how you
94 =head2 Smart-matching against array slices
96 Previously, the following code resulted in a successful match:
102 This odd behaviour has now been fixed [perl #77468].
106 The first argument of the C API function C<Perl_fetch_cop_label> has changed
107 from C<struct refcounted he *> to C<COP *>, to better insulate the user from
108 implementation details.
110 This API function was marked as "may change", and likely isn't in use outside
111 the core. (Neither an unpacked CPAN, nor Google's codesearch, finds any other
116 XXX Any deprecated features, syntax, modules etc. should be listed here.
117 In particular, deprecated modules should be listed here even if they are
118 listed as an updated module in the L</Modules and Pragmata> section.
120 =head2 Use of qw(...) as parentheses
122 Historically the parser fooled itself into thinking that C<qw(...)> literals
123 were always enclosed in parentheses, and as a result you could sometimes omit
124 parentheses around them:
126 for $x qw(a b c) { ... }
128 The parser no longer lies to itself in this way. Wrap the list literal in
131 for $x (qw(a b c)) { ... }
133 =head1 Performance Enhancements
135 XXX Changes which enhance performance without changing behaviour go here. There
136 may well be none in a stable release.
138 [ List each enhancement as a =item entry ]
144 Scalars containing regular expressions now only allocate the part of the C<SV>
145 body they actually use, saving some space.
149 =head1 Modules and Pragmata
151 XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
152 go here. If Module::CoreList is updated, generate an initial draft of the
153 following sections using F<Porting/corelist-perldelta.pl>, which prints stub
154 entries to STDOUT. Results can be pasted in place of the '=head2' entries
155 below. A paragraph summary for important changes should then be added by hand.
156 In an ideal world, dual-life modules would have a F<Changes> file that could be
159 [ Within each section, list entries as a =item entry ]
161 =head2 New Modules and Pragmata
167 L<warnings> and L<warnings::register> can now register categories other than
168 the names of packages using warnings::register. See L<perllexwarn> for more
173 =head2 Updated Modules and Pragmata
179 C<blib> has been upgraded from version 1.05 to 1.06.
183 C<bignum>, C<bigint>, and C<bigrat> have been upgraded from version 0.23 to
188 C<Data::Dumper> has been upgraded from version 2.126 to 2.128.
190 This fixes a crash when using custom sort functions that might cause the stack
195 C<Errno> has been upgraded from version 1.12 to 1.13.
197 On some platforms with unusual header files, like Win32/gcc using mingw64
198 headers, some constants which weren't actually error numbers have been exposed
199 by C<Errno>. This has been fixed (RT#77416).
203 C<ExtUtils::MakeMaker> has been upgraded from version 6.56 to 6.57_01.
207 C<Filter::Simple> has been upgraded from version 0.84 to 0.85.
211 C<Math::BigInt> has been upgraded from version 1.89_01 to 1.92.
212 C<Math::BigInt::Calc> has been upgraded from version 0.52 to 0.53.
214 This fixes incorrect results when computing binomial coefficients (RT#77640).
218 C<Math::BigInt::FastCalc> has been upgraded from version 0.19 to 0.21.
222 C<Module::CoreList> has been upgraded from version 2.37 to 2.38.
226 C<Tie::Hash> has been upgraded from version 1.03 to 1.04.
228 Calling C<< Tie::Hash->TIEHASH() >> used to loop forever. Now it C<croak>s.
232 C<Unicode::Collate> has been upgraded from version 0.56 to 0.59.
236 C<XSLoader> has been upgraded from version 0.10 to 0.11.
240 =head2 Removed Modules and Pragmata
252 XXX Changes to files in F<pod/> go here. Consider grouping entries by
253 file and be sure to link to the appropriate page, e.g. L<perlfunc>.
255 =head2 New Documentation
257 XXX Changes which create B<new> files in F<pod/> go here.
261 XXX Description of the purpose of the new file here
263 =head2 Changes to Existing Documentation
265 XXX Changes which significantly change existing files in F<pod/> go here.
266 However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
275 Many of the optree construction functions are now documented.
281 The following additions or changes have been made to diagnostic output,
282 including warnings and fatal error messages. For the complete list of
283 diagnostic messages, see L<perldiag>.
285 XXX New or changed warnings emitted by the core's C<C> code go here. Also
286 include any changes in L<perldiag> that reconcile it to the C<C> code.
288 [ Within each section, list entries as a =item entry ]
290 =head2 New Diagnostics
292 XXX Newly added diagnostic messages go here
298 Use of qw(...) as parentheses is deprecated
302 =head2 Changes to Existing Diagnostics
304 XXX Changes (i.e. rewording) of diagnostic messages go here
314 =head1 Utility Changes
316 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
317 here. Most of these are built within the directories F<utils> and F<x2p>.
319 [ List utility changes as a =head3 entry for each utility and =item
320 entries for each change
321 Use L<XXX> with program names to get proper documentation linking. ]
329 The use of a deprecated C<goto> construct has been removed (RT#74404).
333 =head1 Configuration and Compilation
335 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
336 go here. Any other changes to the Perl build process should be listed here.
337 However, any platform-specific changes should be listed in the
338 L</Platform Support> section, instead.
340 [ List changes as a =item entry ].
352 XXX Any significant changes to the testing of a freshly built perl should be
353 listed here. Changes which create B<new> files in F<t/> go here as do any
354 large changes to the testing harness (e.g. when parallel testing was added).
355 Changes to existing files in F<t/> aren't worth summarising, although the bugs
356 that they represent may be covered elsewhere.
358 [ List each test improvement as a =item entry ]
364 A rare race condition in F<t/op/while_readdir.t> has been fixed, stopping it
365 from failing randomly when running tests in parallel.
369 The new F<t/op/leaky-magic.t> script tests that magic applied to variables in
370 the main packages does not affect other packages.
374 =head1 Platform Support
376 XXX Any changes to platform support should be listed in the sections below.
378 [ Within the sections, list each platform as a =item entry with specific
379 changes as paragraphs below it. ]
383 XXX List any platforms that this version of perl compiles on, that previous
384 versions did not. These will either be enabled by new files in the F<hints/>
385 directories, or new subdirectories and F<README> files at the top level of the
390 =item XXX-some-platform
396 =head2 Discontinued Platforms
398 XXX List any platforms that this version of perl no longer compiles on.
402 =item XXX-some-platform
408 =head2 Platform-Specific Notes
410 XXX List any changes for specific platforms. This could include configuration
411 and compilation changes or changes in portability/compatibility. However,
412 changes within modules for platforms should generally be listed in the
413 L</Modules and Pragmata> section.
423 Make PerlIOUnix_open honor default permissions on VMS.
425 When perlio became the default and unixio became the default bottom layer, the
426 most common path for creating files from Perl became C<PerlIOUnix_open>, which
427 has always explicitly used C<0666> as the permission mask.
429 To avoid this, C<0777> is now passed as the permissions to C<open()>. In the VMS
430 CRTL, C<0777> has a special meaning over and above intersecting with the current
431 umask; specifically, it allows Unix syscalls to preserve native default
438 =head1 Internal Changes
440 XXX Changes which affect the interface available to C<XS> code go here.
441 Other significant internal changes for future core maintainers should
444 [ List each test improvement as a =item entry ]
450 C<CALL_FPTR> and C<CPERLscope> have been removed deprecated.
452 Those are left from an old implementation of C<MULTIPLICITY> using C++ objects,
453 which has been removed in 5.8. Nowadays these macros do exactly nothing, so they
454 shouldn't be used anymore.
456 For compatibility, they are still defined for external C<XS> code. Only
457 extensions defining C<PERL_CORE> must be updated now.
461 C<lex_stuff_pvs()> has been added as a convenience macro wrapping
462 C<lex_stuff_pvn()> for literal strings.
466 The recursive part of the peephole optimizer is how hookable.
468 In addition to C<PL_peepp>, for hooking into the toplevel peephole optimizer, a
469 C<PL_rpeepp> is now available to hook into the optimizer recursing into
470 side-chains of the optree.
474 =head1 Selected Bug Fixes
476 XXX Important bug fixes in the core language are summarised here.
477 Bug fixes in files in F<ext/> and F<lib/> are best summarised in
478 L</Modules and Pragmata>.
480 [ List each fix as a =item entry ]
486 A regression introduced in perl 5.12.0, making
487 C<< my $x = 3; $x = length(undef) >> result in C<$x> set to C<3> has been
488 fixed. C<$x> will now be C<undef>.
492 A fatal error in regular expressions when processing UTF-8 data has been fixed
497 An erroneous regular expression engine optimization, that caused regex verbs
498 like C<*COMMIT> to sometimes be ignored, has been removed.
502 The perl debugger now also works in taint mode (RT#76872).
506 Several memory leaks in cloning and freeing threaded perl interpreters have been
511 A possible string corruption when doing regular expression matches on overloaded
512 objects has been fixed (RT#77084).
516 Magic applied to variables in the main package no longer affects other
517 packages. See L</Magic Variables Outside the Main Package>, above [perl #76138].
521 Opening a glob reference via C<< open $fh, ">", \*glob >> will no longer cause
522 the glob to be corrupted when the file handle is printed to. This would cause
523 perl to crash whenever the glob's contents were accessed [perl #77492].
527 The postincrement and postdecrement operators, C<++> and C<--> used to cause
528 leaks when being used on references. This has now been fixed.
532 A bug when replacing the glob of a loop variable within the loop has been
533 fixed [perl #21469]. This means the following code will no longer crash:
541 =head1 Known Problems
543 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
544 tests that had to be C<TODO>ed for the release would be noted here, unless
545 they were specific to a particular platform (see below).
547 This is a list of some significant unfixed bugs, which are regressions
548 from either 5.XXX.XXX or 5.XXX.XXX.
550 [ List each fix as a =item entry ]
562 XXX If any significant core contributor has died, we've added a short obituary
565 =head1 Acknowledgements
567 XXX The list of people to thank goes here.
569 =head1 Reporting Bugs
571 If you find what you think is a bug, you might check the articles
572 recently posted to the comp.lang.perl.misc newsgroup and the perl
573 bug database at http://rt.perl.org/perlbug/ . There may also be
574 information at http://www.perl.org/ , the Perl Home Page.
576 If you believe you have an unreported bug, please run the B<perlbug>
577 program included with your release. Be sure to trim your bug down
578 to a tiny but sufficient test case. Your bug report, along with the
579 output of C<perl -V>, will be sent off to perlbug@perl.org to be
580 analysed by the Perl porting team.
582 If the bug you are reporting has security implications, which make it
583 inappropriate to send to a publicly archived mailing list, then please send
584 it to perl5-security-report@perl.org. This points to a closed subscription
585 unarchived mailing list, which includes all the core committers, who be able
586 to help assess the impact of issues, figure out a resolution, and help
587 co-ordinate the release of patches to mitigate or fix the problem across all
588 platforms on which Perl is supported. Please only use this address for
589 security issues in the Perl core, not for modules independently
594 The F<Changes> file for an explanation of how to view exhaustive details
597 The F<INSTALL> file for how to build Perl.
599 The F<README> file for general stuff.
601 The F<Artistic> and F<Copying> files for copyright information.