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perldelta - Documentation and Diagnostics
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1=encoding utf8
2
3=head1 NAME
4
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5[ this is a template for a new perldelta file. Any text flagged as XXX needs
6to be processed before release. ]
7
8perldelta - what is new for perl v5.31.5
d407e309 9
862f380b 10=head1 DESCRIPTION
261e14b0 11
74c14c97 12This document describes differences between the 5.31.4 release and the 5.31.5
862f380b 13release.
261e14b0 14
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15If you are upgrading from an earlier release such as 5.31.3, first read
16L<perl5314delta>, which describes differences between 5.31.3 and 5.31.4.
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17
18=head1 Notice
19
74c14c97 20XXX Any important notices here
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21
22=head1 Core Enhancements
23
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24XXX New core language features go here. Summarize user-visible core language
25enhancements. Particularly prominent performance optimisations could go
26here, but most should go in the L</Performance Enhancements> section.
27
28[ List each enhancement as a =head2 entry ]
29
30=head1 Security
fd41b2d1 31
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32XXX Any security-related notices go here. In particular, any security
33vulnerabilities closed should be noted here rather than in the
34L</Selected Bug Fixes> section.
35
36[ List each security issue as a =head2 entry ]
fd41b2d1 37
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38=head1 Incompatible Changes
39
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40XXX For a release on a stable branch, this section aspires to be:
41
42 There are no changes intentionally incompatible with 5.XXX.XXX
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43 If any exist, they are bugs, and we request that you submit a
44 report. See L</Reporting Bugs> below.
e6132dc0 45
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46[ List each incompatible change as a =head2 entry ]
47
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48=head2 Modifiable variables are no longer permitted in constants
49
50Code like:
51
52 my $var;
53 $sub = sub () { $var };
54
55where C<$var> is referenced elsewhere in some sort of modiable context
56now produces an exception when the sub is defined.
57
58This error can be avoided by adding a return to the sub definition:
59
60 $sub = sub () { return $var };
61
62This has been deprecated since perl 5.22.
63
64[perl #131138]
65
fcbec156 66=head1 Deprecations
e6132dc0 67
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68XXX Any deprecated features, syntax, modules etc. should be listed here.
69
fcbec156 70=head2 Module removals
befef368 71
74c14c97 72XXX Remove this section if not applicable.
befef368 73
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74The following modules will be removed from the core distribution in a
75future release, and will at that time need to be installed from CPAN.
76Distributions on CPAN which require these modules will need to list them as
77prerequisites.
fcbec156 78
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79The core versions of these modules will now issue C<"deprecated">-category
80warnings to alert you to this fact. To silence these deprecation warnings,
81install the modules in question from CPAN.
fcbec156 82
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83Note that these are (with rare exceptions) fine modules that you are encouraged
84to continue to use. Their disinclusion from core primarily hinges on their
85necessity to bootstrapping a fully functional, CPAN-capable Perl installation,
86not usually on concerns over their design.
fcbec156 87
74c14c97 88=over
fcbec156 89
74c14c97 90=item XXX
fcbec156 91
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92XXX Note that deprecated modules should be listed here even if they are listed
93as an updated module in the L</Modules and Pragmata> section.
94
95=back
96
97[ List each other deprecation as a =head2 entry ]
98
99=head1 Performance Enhancements
100
101XXX Changes which enhance performance without changing behaviour go here.
102There may well be none in a stable release.
103
104[ List each enhancement as an =item entry ]
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105
106=over 4
a0348300 107
9c600b76 108=item *
a0348300 109
74c14c97 110XXX
be2eb09e 111
74c14c97 112=back
fcbec156 113
74c14c97 114=head1 Modules and Pragmata
be2eb09e 115
ced2c819 116=head2 Updated Modules and Pragmata
03b7d279 117
74c14c97 118=over 4
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119
120=item *
121
ced2c819 122L<B> has been upgraded from version 1.76 to 1.77.
03b7d279 123
ced2c819 124=item *
74c14c97 125
ced2c819 126L<B::Deparse> has been upgraded from version 1.49 to 1.50.
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127
128=item *
129
ced2c819 130L<Devel::PPPort> has been upgraded from version 3.55 to 3.54.
c8d86fdc 131
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132=item *
133
134L<Digest::MD5> has been upgraded from version 2.55 to 2.55_01.
74c14c97 135
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136=item *
137
138L<Dumpvalue> has been upgraded from version 1.18 to 1.21.
139
140Previously, when dumping elements of an array and encountering an undefined
141value, the string printed would have been C<empty array>. This has been
142changed to what was apparently originally intended: C<empty slot>.
143
ced2c819 144=item *
c8d86fdc 145
ced2c819 146L<ExtUtils::CBuilder> has been upgraded from version 0.280232 to 0.280233.
74c14c97 147
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148=item *
149
150L<Math::BigInt> has been upgraded from version 1.999816 to 1.999817_01.
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151
152=item *
153
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154L<Math::BigInt::FastCalc> has been upgraded from version 0.5008 to 0.5009.
155
156=item *
157
158L<Module::CoreList> has been upgraded from version 5.20190920 to 5.20191020.
159
160=item *
161
162L<Safe> has been upgraded from version 2.40 to 2.41.
163
164=item *
165
166L<threads> has been upgraded from version 2.22 to 2.23.
167
168=item *
169
170L<Time::HiRes> has been upgraded from version 1.9763 to 1.9764.
171
172=item *
173
174L<XS::APItest> has been upgraded from version 1.03 to 1.04.
175
176If there was something important to note about this change, include that here.
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177
178=back
179
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180=head1 Documentation
181
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182=head2 Changes to Existing Documentation
183
184We have attempted to update the documentation to reflect the changes
185listed in this document. If you find any we have missed, send email
186to L<perlbug@perl.org|mailto:perlbug@perl.org>.
187
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188=head3 L<perlguts>
189
190=over 4
191
192=item *
193
194Details of the various stacks within the perl interpreter are now explained
195here.
196
197=back
74c14c97 198
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199Additionally, the following selected changes have been made:
200
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201=head3 URLs have been changed to https://, stale links updated
202
203=over 4
204
205=item *
206
207Where applicable, the URLs in the documentation have been moved from
208using the http:// protocol to https:// . This also affects the location
209of the bug tracker at L<https://rt.perl.org>.
210
211=item *
212
213Some links to OS/2 libraries, Address Sanitizer and other system tools
214had gone stale. These have been updated with working links.
215
216=item *
217
218Some links to old mails on perl5-porters had gone stale. These have been
219updated with working links.
220
221=back
222
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223=head1 Diagnostics
224
225The following additions or changes have been made to diagnostic output,
226including warnings and fatal error messages. For the complete list of
227diagnostic messages, see L<perldiag>.
228
336e728b 229=head2 Changes to Existing Diagnostics
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230
231=over 4
232
233=item *
234
336e728b 235L<Can't use global %s in %s|perldiag/"Can't use global %s in %s">
74c14c97 236
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237This error message has been slightly reformatted from the original C<Can't use
238global %s in "%s">, and in particular misleading error messages like C<Can't
239use global $_ in "my"> are now rendered as C<Can't use global $_ in subroutine
240signature>.
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241
242=item *
243
336e728b 244L<Constants from lexical variables potentially modified elsewhere are no longer permitted|perldiag/"Constants from lexical variables potentially modified elsewhere are no longer permitted">
74c14c97 245
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246This error message replaces the former C<Constants from lexical variables
247potentially modified elsewhere are deprecated. This will not be allowed in Perl
2485.32> to reflect the fact that this previously deprecated usage has now been
249transformed into an exception. The message's classification has also been
250updated from D (deprecated) to F (fatal).
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251
252=back
253
254=head1 Utility Changes
255
256XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go here.
257Most of these are built within the directory F<utils>.
258
259[ List utility changes as a =head2 entry for each utility and =item
260entries for each change
261Use L<XXX> with program names to get proper documentation linking. ]
262
263=head2 L<XXX>
264
265=over 4
266
267=item *
268
269XXX
270
271=back
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272
273=head1 Configuration and Compilation
274
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275XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
276go here. Any other changes to the Perl build process should be listed here.
277However, any platform-specific changes should be listed in the
278L</Platform Support> section, instead.
279
280[ List changes as an =item entry ].
281
fcbec156 282=over 4
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283
284=item *
285
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286Perl now no longer probes for C<d_u32align>, defaulting to C<define>
287on all platforms. This check was error prone when it was done, which
288was on 32-bit platforms only. [perl #133495]
06bfb2b1 289
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290=item *
291
292Documentation and hints for building perl on Z/OS (native EBCDIC) have
293been updated. Still work in progress.
294
295=item *
296
297New probe for malloc_usable_size
298
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299=back
300
301=head1 Testing
302
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303XXX Any significant changes to the testing of a freshly built perl should be
304listed here. Changes which create B<new> files in F<t/> go here as do any
305large changes to the testing harness (e.g. when parallel testing was added).
306Changes to existing files in F<t/> aren't worth summarizing, although the bugs
307that they represent may be covered elsewhere.
308
309XXX If there were no significant test changes, say this:
310
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311Tests were added and changed to reflect the other additions and changes
312in this release.
313
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314XXX If instead there were significant changes, say this:
315
316Tests were added and changed to reflect the other additions and
317changes in this release. Furthermore, these significant changes were
318made:
319
320[ List each test improvement as an =item entry ]
321
322=over 4
323
324=item *
325
326XXX
327
328=back
329
dad02c36 330=head1 Platform Support
8424e368 331
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332XXX Any changes to platform support should be listed in the sections below.
333
334[ Within the sections, list each platform as an =item entry with specific
335changes as paragraphs below it. ]
336
337=head2 New Platforms
338
339XXX List any platforms that this version of perl compiles on, that previous
340versions did not. These will either be enabled by new files in the F<hints/>
341directories, or new subdirectories and F<README> files at the top level of the
342source tree.
343
344=over 4
345
346=item XXX-some-platform
347
348XXX
349
350=back
351
352=head2 Discontinued Platforms
353
354XXX List any platforms that this version of perl no longer compiles on.
fcbec156 355
fcbec156 356=over 4
061637ca 357
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358=item XXX-some-platform
359
360XXX
361
362=back
363
364=head2 Platform-Specific Notes
fcbec156 365
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366XXX List any changes for specific platforms. This could include configuration
367and compilation changes or changes in portability/compatibility. However,
368changes within modules for platforms should generally be listed in the
369L</Modules and Pragmata> section.
370
371=over 4
0076a047 372
2e1181e2 373=item Windows
74c14c97 374
2e1181e2 375Support for building perl with Visual C++ 6.0 has now been removed.
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376
377=back
378
379=head1 Internal Changes
380
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381XXX Changes which affect the interface available to C<XS> code go here. Other
382significant internal changes for future core maintainers should be noted as
383well.
384
385[ List each change as an =item entry ]
386
fcbec156 387=over 4
061637ca 388
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389=item *
390
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391Added the C<<PL_curstackinfo->si_cxsubix>> field. This records the stack
392index of the most recently pushed sub/format/eval context. It is set and
393restored automatically by C<cx_pushsub()>, C<cx_popsub()> etc., but would
394need to be manually managed if you do any unusual manipulation of the
395context stack.
285db695 396
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397=item *
398
399Various macros dealing with character type classification and changing
400case where the input is encoded in UTF-8 now require an extra parameter
401to prevent potential reads beyond the end of the buffer. Use of these
402has generated a deprecation warning since 5.26. Details are in
403L<perldeprecation/In XS code, use of various macros dealing with UTF-8.>
404
9064626f 405=back
ed0cf058 406
9064626f 407=head1 Selected Bug Fixes
ed0cf058 408
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409XXX Important bug fixes in the core language are summarized here. Bug fixes in
410files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
411
412[ List each fix as an =item entry ]
413
9064626f 414=over 4
973ae088 415
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416=item *
417
74c14c97 418XXX
f7faf2ad 419
74c14c97 420=back
8714ff4f 421
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422=head1 Known Problems
423
424XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
425tests that had to be C<TODO>ed for the release would be noted here. Unfixed
426platform specific bugs also go here.
427
428[ List each fix as an =item entry ]
429
430=over 4
8714ff4f 431
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432=item *
433
74c14c97 434XXX
7118f704 435
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436=back
437
74c14c97 438=head1 Errata From Previous Releases
fcbec156 439
74c14c97 440=over 4
a3c77565 441
74c14c97 442=item *
fcbec156 443
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444XXX Add anything here that we forgot to add, or were mistaken about, in
445the perldelta of a previous release.
bd833cba 446
74c14c97 447=back
bd833cba 448
74c14c97 449=head1 Obituary
bd833cba 450
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451XXX If any significant core contributor or member of the CPAN community has
452died, add a short obituary here.
bd833cba 453
74c14c97 454=head1 Acknowledgements
bd833cba 455
74c14c97 456XXX Generate this with:
bd833cba 457
74c14c97 458 perl Porting/acknowledgements.pl v5.31.4..HEAD
8424e368 459
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460=head1 Reporting Bugs
461
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462If you find what you think is a bug, you might check the perl bug database
463at L<https://rt.perl.org/>. There may also be information at
71c89d21 464L<https://www.perl.org/>, the Perl Home Page.
44691e6f 465
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466If you believe you have an unreported bug, please run the L<perlbug> program
467included with your release. Be sure to trim your bug down to a tiny but
468sufficient test case. Your bug report, along with the output of C<perl -V>,
0e18d1c4 469will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
44691e6f 470
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471If the bug you are reporting has security implications which make it
472inappropriate to send to a publicly archived mailing list, then see
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473L<perlsec/SECURITY VULNERABILITY CONTACT INFORMATION>
474for details of how to report the issue.
44691e6f 475
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476=head1 Give Thanks
477
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478If you wish to thank the Perl 5 Porters for the work we had done in Perl 5,
479you can do so by running the C<perlthanks> program:
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480
481 perlthanks
482
483This will send an email to the Perl 5 Porters list with your show of thanks.
484
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485=head1 SEE ALSO
486
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487The F<Changes> file for an explanation of how to view exhaustive details on
488what changed.
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489
490The F<INSTALL> file for how to build Perl.
491
492The F<README> file for general stuff.
493
494The F<Artistic> and F<Copying> files for copyright information.
495
496=cut