5 perl5312delta - what is new for perl v5.31.2
9 This document describes differences between the 5.31.1 release and the 5.31.2
12 If you are upgrading from an earlier release such as 5.31.0, first read
13 L<perl5311delta>, which describes differences between 5.31.0 and 5.31.1.
15 =head1 Modules and Pragmata
17 =head2 Updated Modules and Pragmata
23 L<Devel::PPPort> has been upgraded from version 3.53 to 3.54.
27 L<Exporter> has been upgraded from version 5.73 to 5.74.
31 L<IPC::Cmd> has been upgraded from version 1.02 to 1.04.
35 L<JSON::PP> has been upgraded from version 4.02 to 4.04.
39 L<Module::CoreList> has been upgraded from version 5.20190620 to 5.20190720.
43 L<Opcode> has been upgraded from version 1.43 to 1.44.
47 L<PerlIO::encoding> has been upgraded from version 0.27 to 0.28.
51 L<Pod::Simple> has been upgraded from version 3.38 to 3.39.
55 L<threads::shared> has been upgraded from version 1.60 to 1.61.
61 =head2 New Diagnostics
69 C<L<No digits found for %s literal|perldiag/"No digits found for %s literal">>
71 (F) No hexadecimal digits were found following C<0x> or no binary digits were
72 found following C<0b>.
76 =head2 Changes to Existing Diagnostics
82 C<\N{} here is restricted to one character> is now emitted in the same
83 circumstances where previously C<\N{} in inverted character class or as a range
84 end-point is restricted to one character> was.
86 This is due to new circumstances having been added in Perl 5.30 that weren't
87 covered by the earlier wording.
91 =head1 Configuration and Compilation
97 The C<ECHO> macro is now defined. This is used in a C<dtrace> rule that was
98 originally changed for FreeBSD, and the FreeBSD make apparently predefines it.
99 The Solaris make does not predefine C<ECHO> which broke this rule on Solaris.
100 L<[perl #134218]|https://rt.perl.org/Ticket/Display.html?id=134218>
104 Bison versions 3.1 through 3.4 are now supported.
108 =head1 Platform Support
110 =head2 Platform-Specific Notes
116 C<cc> will be used to populate C<plibpth> if C<cc> is C<clang>.
117 L<[perl #134189]|https://rt.perl.org/Ticket/Display.html?id=134189>
121 C<-Duse64bitint> is now the default on VMS.
125 =head1 Internal Changes
131 The PERL_DESTRUCT_LEVEL environment variable was formerly only honoured on perl
132 binaries built with DEBUGGING support. It is now checked on all perl builds.
133 Its normal use is to force perl to individually free every block of memory
134 which it has allocated before exiting, which is useful when using automated
135 leak detection tools such as valgrind.
139 The API eval_sv() now accepts a C<G_RETHROW> flag. If this flag is set and an
140 exception is thrown while compiling or executing the supplied code, it will be
141 rethrown, and eval_sv() will not return.
142 L<[perl #134177]|https://rt.perl.org/Ticket/Display.html?id=134177>
146 As part of the fix for
147 L<[perl #2754]|https://rt.perl.org/Ticket/Display.html?id=2754> perl_parse()
148 now returns non-zero if exit(0) is called in a C<BEGIN>, C<UNITCHECK> or
153 Most functions which recursively walked an op tree during compilation have been
154 made non-recursive. This avoids SEGVs from stack overflow when the op tree is
155 deeply nested, such as C<$n == 1 ? "one" : $n == 2 ? "two" : ....> (especially
156 in code which is auto-generated).
158 This is particularly noticeable where the code is compiled within a separate
159 thread, as threads tend to have small stacks by default.
163 =head1 Selected Bug Fixes
169 Parsing incomplete hex or binary literals was changed in 5.31.1 to treat such a
170 literal as just the 0, leaving the following C<x> or C<b> to be parsed as part
171 of the next token. This could lead to some silent changes in behaviour, so now
172 incomplete hex or binary literals produce a fatal error.
173 L<[perl #134125]|https://rt.perl.org/Ticket/Display.html?id=134125>
177 eval_pv()'s I<croak_on_error> flag will now throw even if the exception is a
178 false overloaded value.
179 L<[perl #134177]|https://rt.perl.org/Ticket/Display.html?id=134177>
183 C<INIT> blocks and the program itself are no longer run if exit(0) is called
184 within a C<BEGIN>, C<UNITCHECK> or C<CHECK> block.
185 L<[perl #2754]|https://rt.perl.org/Ticket/Display.html?id=2754>
189 C<<< open my $fh, ">>+", undef >>> now opens the temporary file in append mode
190 - writes will seek to the end of file before writing.
191 L<[perl #134221]|https://rt.perl.org/Ticket/Display.html?id=134221>
195 Fixed a SEGV when searching for the source of an uninitialized value warning on
196 an op whose subtree includes an OP_MULTIDEREF.
197 L<[perl #134275]|https://rt.perl.org/Ticket/Display.html?id=134275>
201 =head1 Known Problems
207 The VC++ 6.0 build on Windows is currently broken. Support for this compiler
208 is likely to be removed in the near future.
212 Tests 9-11 in F<t/op/blocks.t> currently fail on Windows.
213 L<[perl #134295]|https://rt.perl.org/Ticket/Display.html?id=134295>
217 =head1 Acknowledgements
219 Perl 5.31.2 represents approximately 4 weeks of development since Perl 5.31.1
220 and contains approximately 7,600 lines of changes across 190 files from 16
223 Excluding auto-generated files, documentation and release tools, there were
224 approximately 3,100 lines of changes to 99 .pm, .t, .c and .h files.
226 Perl continues to flourish into its fourth decade thanks to a vibrant community
227 of users and developers. The following people are known to have contributed
228 the improvements that became Perl 5.31.2:
230 Alexandr Savca, Chris 'BinGOs' Williams, Craig A. Berry, Dagfinn Ilmari
231 Mannsåker, David Mitchell, H.Merijn Brand, James E Keenan, Karen Etheridge,
232 Karl Williamson, Nicolas R., Pali, Paul Evans, Richard Leach, Steve Hay,
233 Svyatoslav, Tony Cook.
235 The list above is almost certainly incomplete as it is automatically generated
236 from version control history. In particular, it does not include the names of
237 the (very much appreciated) contributors who reported issues to the Perl bug
240 Many of the changes included in this version originated in the CPAN modules
241 included in Perl's core. We're grateful to the entire CPAN community for
242 helping Perl to flourish.
244 For a more complete list of all of Perl's historical contributors, please see
245 the F<AUTHORS> file in the Perl source distribution.
247 =head1 Reporting Bugs
249 If you find what you think is a bug, you might check the perl bug database at
250 L<https://rt.perl.org/>. There may also be information at
251 L<http://www.perl.org/>, the Perl Home Page.
253 If you believe you have an unreported bug, please run the L<perlbug> program
254 included with your release. Be sure to trim your bug down to a tiny but
255 sufficient test case. Your bug report, along with the output of C<perl -V>,
256 will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
258 If the bug you are reporting has security implications which make it
259 inappropriate to send to a publicly archived mailing list, then see
260 L<perlsec/SECURITY VULNERABILITY CONTACT INFORMATION> for details of how to
265 If you wish to thank the Perl 5 Porters for the work we had done in Perl 5, you
266 can do so by running the C<perlthanks> program:
270 This will send an email to the Perl 5 Porters list with your show of thanks.
274 The F<Changes> file for an explanation of how to view exhaustive details on
277 The F<INSTALL> file for how to build Perl.
279 The F<README> file for general stuff.
281 The F<Artistic> and F<Copying> files for copyright information.