5 perl5232delta - what is new for perl v5.23.2
9 This document describes differences between the 5.23.1 release and the 5.23.2
12 If you are upgrading from an earlier release such as 5.23.0, first read
13 L<perl5231delta>, which describes differences between 5.23.0 and 5.23.1.
15 =head1 Incompatible Changes
17 =head2 Nested declarations are now disallowed
19 A C<my>, C<our>, or C<state> declaration is no longer allowed inside
20 of another C<my>, C<our>, or C<state> declaration.
22 For example, these are now fatal:
27 L<[perl #125587]|https://rt.perl.org/Ticket/Display.html?id=125587>
29 L<[perl #121058]|https://rt.perl.org/Ticket/Display.html?id=121058>
33 =head2 sysread(), syswrite(), recv() and send() are deprecated on
36 The sysread(), recv(), syswrite() and send() operators
37 are deprecated on handles that have the C<:utf8> layer, either
38 explicitly, or implicitly, eg., with the C<:encoding(UTF-16LE)> layer.
40 Both sysread() and recv() currently use only the C<:utf8> flag for the
41 stream, ignoring the actual layers. Since sysread() and recv() do no
42 UTF-8 validation they can end up creating invalidly encoded scalars.
44 Similarly, syswrite() and send() use only the C<:utf8> flag, otherwise
45 ignoring any layers. If the flag is set, both write the value UTF-8
46 encoded, even if the layer is some different encoding, such as the
49 Ideally, all of these operators would completely ignore the C<:utf8>
50 state, working only with bytes, but this would result in silently
51 breaking existing code. To avoid this a future version of perl will
52 throw an exception when any of sysread(), recv(), syswrite() or send()
53 are called on handle with the C<:utf8> layer.
55 =head1 Performance Enhancements
61 Creating Perl debugger data structures (see L<perldebguts/"Debugger Internals">)
62 for XSUBs and const subs has been removed. This removed one glob/scalar combo
63 for each unique C<.c> file that XSUBs and const subs came from. On startup
64 (C<perl -e"0">) about half a dozen glob/scalar debugger combos were created.
65 Loading XS modules created more glob/scalar combos. These things were created
66 regardless if the perl debugger was being used or not, unlike for pure perl
67 subs, and ignores that the perl debugger can not debug C code.
71 Single arguments in list assign are now slightly faster:
78 =head1 Modules and Pragmata
80 =head2 Updated Modules and Pragmata
86 The PathTools module collection has been upgraded from version 3.55 to
90 L<[perl #125712]|https://rt.perl.org/Ticket/Display.html?id=125712>
94 L<Attribute::Handlers> has been upgraded from version 0.97 to 0.99.
98 L<CPAN::Meta::YAML> has been upgraded from version 0.016 to 0.017.
102 L<Encode> has been upgraded from version 2.75 to 2.76.
106 L<ExtUtils::ParseXS> has been upgraded from version 3.28 to 3.29.
110 L<ExtUtils::Typemaps> has been upgraded from version 3.28 to 3.29.
114 L<File::Find> has been upgraded from version 1.29 to 1.30.
118 L<File::Spec> has been upgraded from version 3.56 to 3.57.
122 L<Filter::Util::Call> has been upgraded from version 1.54 to 1.55.
126 L<Hash::Util> has been upgraded from version 0.18 to 0.19.
128 C<unlock_hashref_recurse> and C<unlock_hash_recurse> didn't
129 actually unlock parts of the data structures...
135 L<Module::CoreList> has been upgraded from version 5.20150720 to 5.20150820.
139 L<perlfaq> has been upgraded from version 5.021009 to 5.021010.
143 L<POSIX> has been upgraded from version 1.55 to 1.56.
147 L<Term::Cap> has been upgraded from version 1.15 to 1.17.
151 L<Unicode::UCD> has been upgraded from version 0.61 to 0.62.
157 =head2 Changes to Existing Documentation
165 This note has been added to perlpolicy:
167 While civility is required, kindness is encouraged; if you have any doubt
168 about whether you are being civil, simply ask yourself, "Am I being kind?"
179 Use of C<$OLD_PERL_VERSION> is now discouraged.
185 The following additions or changes have been made to diagnostic output,
186 including warnings and fatal error messages. For the complete list of
187 diagnostic messages, see L<perldiag>.
189 =head2 New Diagnostics
197 L<Can't redeclare "%s" in "%s"|perldiag/"Can't redeclare "%s" in "%s"">
199 (F) A "my", "our" or "state" declaration was found within another declaration,
200 such as C<my ($x, my($y), $z)> or C<our (my $x)>.
210 L<%s() is deprecated on :utf8 handles|perldiag/"%s() is deprecated on :utf8 handles">
212 (W deprecated) The sysread(), recv(), syswrite() and send() operators
213 are deprecated on handles that have the C<:utf8> layer, either
214 explicitly, or implicitly, eg., with the C<:encoding(UTF-16LE)> layer.
216 Both sysread() and recv() currently use only the C<:utf8> flag for the
217 stream, ignoring the actual layers. Since sysread() and recv() do no
218 UTF-8 validation they can end up creating invalidly encoded scalars.
220 Similarly, syswrite() and send() use only the C<:utf8> flag, otherwise
221 ignoring any layers. If the flag is set, both write the value UTF-8
222 encoded, even if the layer is some different encoding, such as the
225 Ideally, all of these operators would completely ignore the C<:utf8>
226 state, working only with bytes, but this would result in silently
227 breaking existing code. To avoid this a future version of perl will
228 throw an exception when any of sysread(), recv(), syswrite() or send()
229 are called on handle with the C<:utf8> layer.
233 =head2 Changes to Existing Diagnostics
239 The diagnostic C<< Hexadecimal float: internal error >> has been changed to
240 C<< Hexadecimal float: internal error (%s) >> to include more information.
244 =head1 Configuration and Compilation
250 F<Configure> should handle spaces in paths a little better.
260 A new test (F<t/op/aassign.t>) has been added to test the list assignment operator
265 =head1 Internal Changes
271 C<PL_sawalias> and C<GPf_ALIASED_SV> have been removed.
275 C<GvASSIGN_GENERATION> and C<GvASSIGN_GENERATION_set> have been removed.
279 =head1 Selected Bug Fixes
285 Perl can again be compiled with any Unicode version. This used to
286 (mostly) work, but was lost in v5.18 through v5.20. The property
287 C<Name_Alias> did not exist prior to Unicode 5.0. L<Unicode::UCD>
288 incorrectly said it did. This has been fixed.
292 Very large code-points (beyond Unicode) in regular expressions no
293 longer cause a buffer overflow in some cases when converted to UTF-8.
294 L<[perl #125826]|https://rt.perl.org/Ticket/Display.html?id=125826>
298 The integer overflow check for the range operator (...) in list
299 context now correctly handles the case where the size of the range is
300 larger than the address space. This could happen on 32-bits with
302 L<[perl #125781]|https://rt.perl.org/Ticket/Display.html?id=125781>
306 A crash with C<< %::=(); J->${\"::"} >> has been fixed.
307 L<[perl #125541]|https://rt.perl.org/Ticket/Display.html?id=125541>
311 =head1 Acknowledgements
313 Perl 5.23.2 represents approximately 4 weeks of development since Perl 5.23.1
314 and contains approximately 22,000 lines of changes across 240 files from 23
317 Excluding auto-generated files, documentation and release tools, there were
318 approximately 17,000 lines of changes to 140 .pm, .t, .c and .h files.
320 Perl continues to flourish into its third decade thanks to a vibrant community
321 of users and developers. The following people are known to have contributed the
322 improvements that became Perl 5.23.2:
324 Aaron Priven, Aristotle Pagaltzis, Chris 'BinGOs' Williams, Craig A. Berry,
325 Dagfinn Ilmari Mannsåker, Daniel Dragan, David Mitchell, Ed J, Father
326 Chrysostomos, H.Merijn Brand, Ivan Pozdeev, James E Keenan, Jarkko Hietaniemi,
327 Karen Etheridge, Karl Williamson, Ludovic E. R. Tolhurst-Cleaver, Lukas Mai,
328 Matthew Horsfall, Reini Urban, Ricardo Signes, Sisyphus, Steve Hay, Tony Cook.
330 The list above is almost certainly incomplete as it is automatically generated
331 from version control history. In particular, it does not include the names of
332 the (very much appreciated) contributors who reported issues to the Perl bug
335 Many of the changes included in this version originated in the CPAN modules
336 included in Perl's core. We're grateful to the entire CPAN community for
337 helping Perl to flourish.
339 For a more complete list of all of Perl's historical contributors, please see
340 the F<AUTHORS> file in the Perl source distribution.
342 =head1 Reporting Bugs
344 If you find what you think is a bug, you might check the articles recently
345 posted to the comp.lang.perl.misc newsgroup and the perl bug database at
346 L<https://rt.perl.org/> . There may also be information at
347 L<http://www.perl.org/> , the Perl Home Page.
349 If you believe you have an unreported bug, please run the L<perlbug> program
350 included with your release. Be sure to trim your bug down to a tiny but
351 sufficient test case. Your bug report, along with the output of C<perl -V>,
352 will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
354 If the bug you are reporting has security implications, which make it
355 inappropriate to send to a publicly archived mailing list, then please send it
356 to perl5-security-report@perl.org. This points to a closed subscription
357 unarchived mailing list, which includes all the core committers, who will be
358 able to help assess the impact of issues, figure out a resolution, and help
359 co-ordinate the release of patches to mitigate or fix the problem across all
360 platforms on which Perl is supported. Please only use this address for
361 security issues in the Perl core, not for modules independently distributed on
366 The F<Changes> file for an explanation of how to view exhaustive details on
369 The F<INSTALL> file for how to build Perl.
371 The F<README> file for general stuff.
373 The F<Artistic> and F<Copying> files for copyright information.