5 [ this is a template for a new perldelta file. Any text flagged as XXX needs
6 to be processed before release. ]
8 perldelta - what is new for perl v5.25.8
12 This document describes differences between the 5.25.7 release and the 5.25.8
15 If you are upgrading from an earlier release such as 5.25.6, first read
16 L<perl5257delta>, which describes differences between 5.25.6 and 5.25.7.
20 XXX Any important notices here
22 =head1 Core Enhancements
24 XXX New core language features go here. Summarize user-visible core language
25 enhancements. Particularly prominent performance optimisations could go
26 here, but most should go in the L</Performance Enhancements> section.
28 [ List each enhancement as a =head2 entry ]
30 =head2 New Hash Function For 64-bit Builds
32 We have switched to a hybrid hash function to better balance
33 performance for short and long keys.
35 For short keys, 16 bytes and under, we use an optimised variant of
36 One At A Time Hard, and for longer keys we use Siphash 1-3. For very
37 long keys this is a big improvement in performance. For shorter keys
38 there is a modest improvement.
42 XXX Any security-related notices go here. In particular, any security
43 vulnerabilities closed should be noted here rather than in the
44 L</Selected Bug Fixes> section.
46 [ List each security issue as a =head2 entry ]
48 =head1 Incompatible Changes
50 XXX For a release on a stable branch, this section aspires to be:
52 There are no changes intentionally incompatible with 5.XXX.XXX
53 If any exist, they are bugs, and we request that you submit a
54 report. See L</Reporting Bugs> below.
56 [ List each incompatible change as a =head2 entry ]
60 XXX Any deprecated features, syntax, modules etc. should be listed here.
62 =head2 Module removals
64 XXX Remove this section if inapplicable.
66 The following modules will be removed from the core distribution in a
67 future release, and will at that time need to be installed from CPAN.
68 Distributions on CPAN which require these modules will need to list them as
71 The core versions of these modules will now issue C<"deprecated">-category
72 warnings to alert you to this fact. To silence these deprecation warnings,
73 install the modules in question from CPAN.
75 Note that these are (with rare exceptions) fine modules that you are encouraged
76 to continue to use. Their disinclusion from core primarily hinges on their
77 necessity to bootstrapping a fully functional, CPAN-capable Perl installation,
78 not usually on concerns over their design.
84 XXX Note that deprecated modules should be listed here even if they are listed
85 as an updated module in the L</Modules and Pragmata> section.
89 [ List each other deprecation as a =head2 entry ]
91 =head1 Performance Enhancements
93 XXX Changes which enhance performance without changing behaviour go here.
94 There may well be none in a stable release.
96 [ List each enhancement as a =item entry ]
100 =item * New Faster Hash Function on 64 bit builds
102 We use a different hash function for short and long keys. This should
103 improve performance and security, especially for long keys.
105 =item * readline is faster
107 Reading from a file line-by-line with c<readline()> or C<< <> >> should
108 now typically be faster due to a better implementation of the code that
109 searches for the next newline character.
113 =head1 Modules and Pragmata
115 XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
116 go here. If Module::CoreList is updated, generate an initial draft of the
117 following sections using F<Porting/corelist-perldelta.pl>. A paragraph summary
118 for important changes should then be added by hand. In an ideal world,
119 dual-life modules would have a F<Changes> file that could be cribbed.
121 [ Within each section, list entries as a =item entry ]
123 =head2 New Modules and Pragmata
133 =head2 Updated Modules and Pragmata
139 L<XXX> has been upgraded from version A.xx to B.yy.
143 L<Pod::Simple> has been upgraded from version 3.32 to 3.35.
147 L<Test::Simple> has been upgraded from version 1.302067 to 1.302071.
151 =head2 Removed Modules and Pragmata
163 XXX Changes to files in F<pod/> go here. Consider grouping entries by
164 file and be sure to link to the appropriate page, e.g. L<perlfunc>.
166 =head2 New Documentation
168 XXX Changes which create B<new> files in F<pod/> go here.
172 XXX Description of the purpose of the new file here
174 =head2 Changes to Existing Documentation
176 XXX Changes which significantly change existing files in F<pod/> go here.
177 However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
186 XXX Description of the change here
192 The following additions or changes have been made to diagnostic output,
193 including warnings and fatal error messages. For the complete list of
194 diagnostic messages, see L<perldiag>.
196 XXX New or changed warnings emitted by the core's C<C> code go here. Also
197 include any changes in L<perldiag> that reconcile it to the C<C> code.
199 =head2 New Diagnostics
201 XXX Newly added diagnostic messages go under here, separated into New Errors
210 XXX L<message|perldiag/"message">
220 XXX L<message|perldiag/"message">
224 =head2 Changes to Existing Diagnostics
226 XXX Changes (i.e. rewording) of diagnostic messages go here
232 XXX Describe change here
236 =head1 Utility Changes
238 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here.
239 Most of these are built within the directory F<utils>.
241 [ List utility changes as a =head2 entry for each utility and =item
242 entries for each change
243 Use L<XXX> with program names to get proper documentation linking. ]
255 =head1 Configuration and Compilation
257 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
258 go here. Any other changes to the Perl build process should be listed here.
259 However, any platform-specific changes should be listed in the
260 L</Platform Support> section, instead.
262 [ List changes as a =item entry ].
268 Zero out the alignment bytes when calculating the bytes for 80-bit C<NaN>
269 and C<Inf> to make builds more reproducible. [perl #130133]
273 Since 5.18 for testing purposes we have included support for
274 building perl with a variety of non-standard, and non-recommended
275 hash functions. Since we do not recommend the use of these functions
276 we have removed them and their corresponding build options. Specifically
277 this includes the following build options:
281 PERL_HASH_FUNC_SUPERFAST
282 PERL_HASH_FUNC_MURMUR3
283 PERL_HASH_FUNC_ONE_AT_A_TIME
284 PERL_HASH_FUNC_ONE_AT_A_TIME_OLD
285 PERL_HASH_FUNC_MURMUR_HASH_64A
286 PERL_HASH_FUNC_MURMUR_HASH_64B
292 XXX Any significant changes to the testing of a freshly built perl should be
293 listed here. Changes which create B<new> files in F<t/> go here as do any
294 large changes to the testing harness (e.g. when parallel testing was added).
295 Changes to existing files in F<t/> aren't worth summarizing, although the bugs
296 that they represent may be covered elsewhere.
298 [ List each test improvement as a =item entry ]
308 =head1 Platform Support
310 XXX Any changes to platform support should be listed in the sections below.
312 [ Within the sections, list each platform as a =item entry with specific
313 changes as paragraphs below it. ]
317 XXX List any platforms that this version of perl compiles on, that previous
318 versions did not. These will either be enabled by new files in the F<hints/>
319 directories, or new subdirectories and F<README> files at the top level of the
324 =item XXX-some-platform
330 =head2 Discontinued Platforms
332 XXX List any platforms that this version of perl no longer compiles on.
336 =item XXX-some-platform
342 =head2 Platform-Specific Notes
344 XXX List any changes for specific platforms. This could include configuration
345 and compilation changes or changes in portability/compatibility. However,
346 changes within modules for platforms should generally be listed in the
347 L</Modules and Pragmata> section.
351 =item XXX-some-platform
357 =head1 Internal Changes
359 XXX Changes which affect the interface available to C<XS> code go here. Other
360 significant internal changes for future core maintainers should be noted as
363 [ List each change as a =item entry ]
369 A new API function, C<sv_set_undef(sv)>, has been added. This is
370 equivalent to C<sv_setsv(sv, &PL_sv_undef)>, but is more efficient.
374 =head1 Selected Bug Fixes
376 XXX Important bug fixes in the core language are summarized here. Bug fixes in
377 files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
379 [ List each fix as a =item entry ]
389 =head1 Known Problems
391 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
392 tests that had to be C<TODO>ed for the release would be noted here. Unfixed
393 platform specific bugs also go here.
395 [ List each fix as a =item entry ]
405 =head1 Errata From Previous Releases
411 XXX Add anything here that we forgot to add, or were mistaken about, in
412 the perldelta of a previous release.
418 XXX If any significant core contributor has died, we've added a short obituary
421 =head1 Acknowledgements
423 XXX Generate this with:
425 perl Porting/acknowledgements.pl v5.25.5..HEAD
427 =head1 Reporting Bugs
429 If you find what you think is a bug, you might check the perl bug database
430 at L<https://rt.perl.org/> . There may also be information at
431 L<http://www.perl.org/> , the Perl Home Page.
433 If you believe you have an unreported bug, please run the L<perlbug> program
434 included with your release. Be sure to trim your bug down to a tiny but
435 sufficient test case. Your bug report, along with the output of C<perl -V>,
436 will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
438 If the bug you are reporting has security implications which make it
439 inappropriate to send to a publicly archived mailing list, then see
440 L<perlsec/SECURITY VULNERABILITY CONTACT INFORMATION>
441 for details of how to report the issue.
445 The F<Changes> file for an explanation of how to view exhaustive details on
448 The F<INSTALL> file for how to build Perl.
450 The F<README> file for general stuff.
452 The F<Artistic> and F<Copying> files for copyright information.