4 * changelogged up to 38ef960
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
171 =head2 Updated Modules and Pragmata
177 C<blib> has been upgraded from version 1.05 to 1.06.
181 C<bignum>, C<bigint>, and C<bigrat> have been upgraded from version 0.23 to
186 C<warnings> has been upgraded from version 1.10 to 1.11.
188 C<warnings::register> has been upgraded from version 1.01 to 1.02.
190 It is now possible to register warning categories other than the names of
191 packages using warnings::register. See L<perllexwarn> for more information.
195 C<B::Debug> has been upgraded from version 1.12 to 1.14.
199 C<Data::Dumper> has been upgraded from version 2.126 to 2.128.
201 This fixes a crash when using custom sort functions that might cause the stack
206 C<Errno> has been upgraded from version 1.12 to 1.13.
208 On some platforms with unusual header files, like Win32/gcc using mingw64
209 headers, some constants which weren't actually error numbers have been exposed
210 by C<Errno>. This has been fixed (RT#77416).
214 C<ExtUtils::MakeMaker> has been upgraded from version 6.56 to 6.57_05.
218 C<Filter::Simple> has been upgraded from version 0.84 to 0.85.
222 C<Math::BigInt> has been upgraded from version 1.89_01 to 1.95.
223 C<Math::BigInt::Calc> has been upgraded from version 0.52 to 0.54.
225 This fixes, among other things, incorrect results when computing binomial
226 coefficients (RT#77640).
230 C<Math::BigInt::FastCalc> has been upgraded from version 0.19 to 0.22.
234 C<Module::CoreList> has been upgraded from version 2.37 to 2.38.
238 C<POSIX> has been upgraded from version 1.19 to 1.20.
240 It now includes constants for POSIX signal constants.
244 C<Tie::Hash> has been upgraded from version 1.03 to 1.04.
246 Calling C<< Tie::Hash->TIEHASH() >> used to loop forever. Now it C<croak>s.
250 C<Unicode::Collate> has been upgraded from version 0.56 to 0.59.
254 C<XSLoader> has been upgraded from version 0.10 to 0.11.
258 =head2 Removed Modules and Pragmata
270 XXX Changes to files in F<pod/> go here. Consider grouping entries by
271 file and be sure to link to the appropriate page, e.g. L<perlfunc>.
273 =head2 New Documentation
275 XXX Changes which create B<new> files in F<pod/> go here.
279 XXX Description of the purpose of the new file here
281 =head2 Changes to Existing Documentation
283 XXX Changes which significantly change existing files in F<pod/> go here.
284 However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
293 Many of the optree construction functions are now documented.
299 The following additions or changes have been made to diagnostic output,
300 including warnings and fatal error messages. For the complete list of
301 diagnostic messages, see L<perldiag>.
303 XXX New or changed warnings emitted by the core's C<C> code go here. Also
304 include any changes in L<perldiag> that reconcile it to the C<C> code.
306 [ Within each section, list entries as a =item entry ]
308 =head2 New Diagnostics
310 XXX Newly added diagnostic messages go here
316 Use of qw(...) as parentheses is deprecated
320 =head2 Changes to Existing Diagnostics
322 XXX Changes (i.e. rewording) of diagnostic messages go here
332 =head1 Utility Changes
334 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
335 here. Most of these are built within the directories F<utils> and F<x2p>.
337 [ List utility changes as a =head3 entry for each utility and =item
338 entries for each change
339 Use L<XXX> with program names to get proper documentation linking. ]
347 The use of a deprecated C<goto> construct has been removed (RT#74404).
351 =head1 Configuration and Compilation
353 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
354 go here. Any other changes to the Perl build process should be listed here.
355 However, any platform-specific changes should be listed in the
356 L</Platform Support> section, instead.
358 [ List changes as a =item entry ].
370 XXX Any significant changes to the testing of a freshly built perl should be
371 listed here. Changes which create B<new> files in F<t/> go here as do any
372 large changes to the testing harness (e.g. when parallel testing was added).
373 Changes to existing files in F<t/> aren't worth summarising, although the bugs
374 that they represent may be covered elsewhere.
376 [ List each test improvement as a =item entry ]
382 A rare race condition in F<t/op/while_readdir.t> has been fixed, stopping it
383 from failing randomly when running tests in parallel.
387 The new F<t/op/leaky-magic.t> script tests that magic applied to variables in
388 the main packages does not affect other packages.
392 =head1 Platform Support
394 XXX Any changes to platform support should be listed in the sections below.
396 [ Within the sections, list each platform as a =item entry with specific
397 changes as paragraphs below it. ]
401 XXX List any platforms that this version of perl compiles on, that previous
402 versions did not. These will either be enabled by new files in the F<hints/>
403 directories, or new subdirectories and F<README> files at the top level of the
408 =item XXX-some-platform
414 =head2 Discontinued Platforms
416 XXX List any platforms that this version of perl no longer compiles on.
420 =item XXX-some-platform
426 =head2 Platform-Specific Notes
428 XXX List any changes for specific platforms. This could include configuration
429 and compilation changes or changes in portability/compatibility. However,
430 changes within modules for platforms should generally be listed in the
431 L</Modules and Pragmata> section.
441 Make PerlIOUnix_open honor default permissions on VMS.
443 When perlio became the default and unixio became the default bottom layer, the
444 most common path for creating files from Perl became C<PerlIOUnix_open>, which
445 has always explicitly used C<0666> as the permission mask.
447 To avoid this, C<0777> is now passed as the permissions to C<open()>. In the VMS
448 CRTL, C<0777> has a special meaning over and above intersecting with the current
449 umask; specifically, it allows Unix syscalls to preserve native default
456 =head1 Internal Changes
458 XXX Changes which affect the interface available to C<XS> code go here.
459 Other significant internal changes for future core maintainers should
462 [ List each test improvement as a =item entry ]
468 C<CALL_FPTR> and C<CPERLscope> have been removed deprecated.
470 Those are left from an old implementation of C<MULTIPLICITY> using C++ objects,
471 which has been removed in 5.8. Nowadays these macros do exactly nothing, so they
472 shouldn't be used anymore.
474 For compatibility, they are still defined for external C<XS> code. Only
475 extensions defining C<PERL_CORE> must be updated now.
479 C<lex_stuff_pvs()> has been added as a convenience macro wrapping
480 C<lex_stuff_pvn()> for literal strings.
484 The recursive part of the peephole optimizer is how hookable.
486 In addition to C<PL_peepp>, for hooking into the toplevel peephole optimizer, a
487 C<PL_rpeepp> is now available to hook into the optimizer recursing into
488 side-chains of the optree.
492 =head1 Selected Bug Fixes
494 XXX Important bug fixes in the core language are summarised here.
495 Bug fixes in files in F<ext/> and F<lib/> are best summarised in
496 L</Modules and Pragmata>.
498 [ List each fix as a =item entry ]
504 A regression introduced in perl 5.12.0, making
505 C<< my $x = 3; $x = length(undef) >> result in C<$x> set to C<3> has been
506 fixed. C<$x> will now be C<undef>.
510 A fatal error in regular expressions when processing UTF-8 data has been fixed
515 An erroneous regular expression engine optimization, that caused regex verbs
516 like C<*COMMIT> to sometimes be ignored, has been removed.
520 The perl debugger now also works in taint mode (RT#76872).
524 Several memory leaks in cloning and freeing threaded perl interpreters have been
529 A possible string corruption when doing regular expression matches on overloaded
530 objects has been fixed (RT#77084).
534 Magic applied to variables in the main package no longer affects other
535 packages. See L</Magic Variables Outside the Main Package>, above [perl #76138].
539 Opening a glob reference via C<< open $fh, ">", \*glob >> will no longer cause
540 the glob to be corrupted when the file handle is printed to. This would cause
541 perl to crash whenever the glob's contents were accessed [perl #77492].
545 The postincrement and postdecrement operators, C<++> and C<--> used to cause
546 leaks when being used on references. This has now been fixed.
550 A bug when replacing the glob of a loop variable within the loop has been
551 fixed [perl #21469]. This means the following code will no longer crash:
559 Perl would segfault if the undocumented C<Internals> functions that
560 used reference prototypes were called with the C<&foo()> syntax,
561 e.g. C<&Internals::SvREADONLY(undef)> [perl #77776].
563 These functions now call C<SvROK> on their arguments before
564 dereferencing them with C<SvRV>, and we test for this case in
565 F<t/lib/universal.t>.
569 =head1 Known Problems
571 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
572 tests that had to be C<TODO>ed for the release would be noted here, unless
573 they were specific to a particular platform (see below).
575 This is a list of some significant unfixed bugs, which are regressions
576 from either 5.XXX.XXX or 5.XXX.XXX.
578 [ List each fix as a =item entry ]
590 XXX If any significant core contributor has died, we've added a short obituary
593 =head1 Acknowledgements
595 XXX The list of people to thank goes here.
597 =head1 Reporting Bugs
599 If you find what you think is a bug, you might check the articles
600 recently posted to the comp.lang.perl.misc newsgroup and the perl
601 bug database at http://rt.perl.org/perlbug/ . There may also be
602 information at http://www.perl.org/ , the Perl Home Page.
604 If you believe you have an unreported bug, please run the B<perlbug>
605 program included with your release. Be sure to trim your bug down
606 to a tiny but sufficient test case. Your bug report, along with the
607 output of C<perl -V>, will be sent off to perlbug@perl.org to be
608 analysed by the Perl porting team.
610 If the bug you are reporting has security implications, which make it
611 inappropriate to send to a publicly archived mailing list, then please send
612 it to perl5-security-report@perl.org. This points to a closed subscription
613 unarchived mailing list, which includes all the core committers, who be able
614 to help assess the impact of issues, figure out a resolution, and help
615 co-ordinate the release of patches to mitigate or fix the problem across all
616 platforms on which Perl is supported. Please only use this address for
617 security issues in the Perl core, not for modules independently
622 The F<Changes> file for an explanation of how to view exhaustive details
625 The F<INSTALL> file for how to build Perl.
627 The F<README> file for general stuff.
629 The F<Artistic> and F<Copying> files for copyright information.