5 perl52111delta - what is new for perl v5.21.11
9 This document describes differences between the 5.21.10 release and the 5.21.11
12 If you are upgrading from an earlier release such as 5.21.9, first read
13 L<perl52110delta>, which describes differences between 5.21.9 and 5.21.10.
17 =head2 Making all warnings fatal is discouraged
19 The documentation for L<fatal warnings|warnings/Fatal Warnings> notes that
20 C<< use warnings FATAL => 'all' >> is discouraged and provides stronger
21 language about the risks of fatal warnings in general.
23 =head1 Modules and Pragmata
25 =head2 Updated Modules and Pragmata
31 L<attributes> has been upgraded from version 0.26 to 0.27.
35 L<B> has been upgraded from version 1.57 to 1.58.
39 L<B::Deparse> has been upgraded from version 1.34 to 1.35.
41 C<< <<>> >> is now correctly deparsed.
45 L<Config::Perl::V> has been upgraded from version 0.23 to 0.24.
49 L<CPAN> has been upgraded from version 2.10 to 2.11.
53 L<Cwd> has been upgraded from version 3.55 to 3.56.
57 L<ExtUtils::Miniperl> has been upgraded from version 1.04 to 1.05.
61 L<ExtUtils::ParseXS> has been upgraded from version 3.27 to 3.28.
65 L<ExtUtils::Typemaps> has been upgraded from version 3.25 to 3.28.
69 L<File::Spec> has been upgraded from version 3.55 to 3.56.
73 L<if> has been upgraded from version 0.0603 to 0.0604.
75 The documentation now notes that this module also works with C<no>.
79 L<IO::Socket::IP> has been upgraded from version 0.36 to 0.37.
83 L<Module::CoreList> has been upgraded from version 5.20150320 to 5.20150420.
85 Updated to cover the latest releases of Perl. Also fixes a fencepost error in
86 is_core() and copes with versions that do not match x.yyyzzz.
90 L<perl5db.pl> has been upgraded from 1.48 to 1.49.
92 The debugger would cause an assertion failure.
93 L<[perl #124127]|https://rt.perl.org/Ticket/Display.html?id=124127>
97 L<PerlIO::mmap> has been upgraded from version 0.013 to 0.014.
101 L<utf8> has been upgraded from version 1.15 to 1.16.
103 Minor documentation update only.
107 L<warnings> has been upgraded from version 1.31 to 1.32.
113 =head2 Changes to Existing Documentation
121 This document has been significantly updated in the light of recent
122 improvements to EBCDIC support.
132 Mention that C<study()> is currently a no-op.
142 The OOK example has been updated to account for COW changes and a change in the
143 storage of the offset.
147 =head3 L<perlhacktips>
153 Documentation has been added illustrating the perils of assuming the contents
154 of static memory pointed to by the return values of Perl wrappers for C library
155 functions doesn't change.
165 Out-of-date VMS-specific information has been fixed/simplified.
169 =head3 L<perluniintro>
175 Advice for how to make sure your strings and regular expression patterns are
176 interpreted as Unicode has been revised to account for the new Perl 5.22 EBCDIC
187 Out-of-date and/or incorrect material has been removed.
197 F<t/porting/re_context.t> has been added to test that L<utf8> and its
198 dependencies only use the subset of the C<$1..$n> capture vars that
199 Perl_save_re_context() is hard-coded to localize, because that function has no
200 efficient way of determining at runtime what vars to localize.
204 =head1 Platform Support
206 =head2 Platform-Specific Notes
212 F<miniperl.exe> is now built with C<-fno-strict-aliasing>, allowing 64-bit
213 builds to complete on GCC 4.8.
214 L<[perl #123976]|https://rt.perl.org/Ticket/Display.html?id=123976>
216 C<test-prep> again depends on C<test-prep-gcc> for GCC builds.
217 L<[perl #124221]|https://rt.perl.org/Ticket/Display.html?id=124221>
221 =head1 Internal Changes
227 Perl 5.21.2 introduced a new build option, C<-DPERL_OP_PARENT>, which causes
228 the last C<op_sibling> pointer to refer back to the parent rather than being
229 C<NULL>, and where instead a new flag indicates the end of the chain. In this
230 release, the new implementation has been revised; in particular:
236 On C<PERL_OP_PARENT> builds, the C<op_sibling> field has been renamed
237 C<op_sibparent> to reflect its new dual purpose. Since the intention is that
238 this field should primarily be accessed via macros, this change should be
239 transparent for code written to work under C<PERL_OP_PARENT>.
243 The newly-introduced C<op_lastsib> flag bit has been renamed C<op_moresib> and
244 its logic inverted; i.e. it is initialised to zero in a new op, and is changed
245 to 1 when an op gains a sibling.
249 The function C<Perl_op_parent> is now only available on C<PERL_OP_PARENT>
250 builds. Using it on a plain build will be a compile-timer error.
254 Three new macros, C<OpMORESIB_set>, C<OpLASTSIB_set>, C<OpMAYBESIB_set> have
255 been added, which are intended to be a low-level portable way to set
256 C<op_sibling> / C<op_sibparent> while also updating C<op_moresib>. The first
257 sets the sibling pointer to a new sibling, the second makes the op the last
258 sibling, and the third conditionally does the first or second action. The
259 C<op_sibling_splice()> function is retained as a higher-level interface that
260 can also maintain consistency in the parent at the same time (e.g. by updating
261 C<op_first> and C<op_last> where appropriate).
265 The macro C<OpSIBLING_set>, added in Perl 5.21.2, has been removed. It didn't
266 manipulate C<op_moresib> and has been superseded by C<OpMORESIB_set> et al.
270 The C<op_sibling_splice> function now accepts a null C<parent> argument where
271 the splicing doesn't affect the first or last ops in the sibling chain, and
272 thus where the parent doesn't need to be updated accordingly.
278 =head1 Selected Bug Fixes
284 C<pack("D", $x)> and C<pack("F", $x)> now zero the padding on x86 long double
285 builds. GCC 4.8 and later, under some build options, would either overwrite
286 the zero-initialized padding, or bypass the initialized buffer entirely. This
287 caused F<op/pack.t> to fail.
288 L<[perl #123971]|https://rt.perl.org/Ticket/Display.html?id=123971>
292 Extending an array cloned from a parent thread could result in "Modification of
293 a read-only value attempted" errors when attempting to modify the new elements.
294 L<[perl #124127]|https://rt.perl.org/Ticket/Display.html?id=124127>
298 An assertion failure and subsequent crash with C<< *x=<y> >> has been fixed.
299 L<[perl #123790]|https://rt.perl.org/Ticket/Display.html?id=123790>
303 An optimization for state variable initialization introduced in Perl 5.21.6 has
304 been reverted because it was found to exacerbate some other existing buggy
306 L<[perl #124160]|https://rt.perl.org/Ticket/Display.html?id=124160>
310 The extension of another optimization to cover more ops in Perl 5.21 has also
311 been reverted to its Perl 5.20 state as a temporary fix for regression issues
313 L<[perl #123790]|https://rt.perl.org/Ticket/Display.html?id=123790>
317 New bitwise ops added in Perl 5.21.9 accidentally caused C<$^H |= 0x1c020000>
318 to enable all features. This has now been fixed.
322 A possible crashing/looping bug has been fixed.
323 L<[perl #124099]|https://rt.perl.org/Ticket/Display.html?id=124099>
327 UTF-8 variable names used in array indexes, unquoted UTF-8 HERE-document
328 terminators and UTF-8 function names all now work correctly.
329 L<[perl #124113]|https://rt.perl.org/Ticket/Display.html?id=124113>
333 Breakage in C<require(VERSION)> (with parentheses), introduced in Perl 5.21.6,
335 L<[perl #124135]|https://rt.perl.org/Ticket/Display.html?id=124135>
339 Wide char warnings, wrongly raised in UTF-8 locales since Perl 5.21.8, are now
341 L<[perl #123527]|https://rt.perl.org/Ticket/Display.html?id=123527>
345 A subtle bug introduced in Perl 5.21.4 involving UTF-8 in regular expressions
346 and sometimes causing a crash has been fixed. A new test script has been added
347 to test this fix; see under L</Testing>.
348 L<[perl #124109]|https://rt.perl.org/Ticket/Display.html?id=124109>
352 A change introduced in Perl 5.21.10 that broke the autovivification CPAN module
357 A bug whereby C<< 'FOO'->f() >> lost the read-only status of C<FOO>, introduced
358 in Perl 5.21.7, has been fixed.
359 L<[perl #123619]|https://rt.perl.org/Ticket/Display.html?id=123619>
363 A regression in Perl 5.21 in the matching of C</[A-Z]/ai> has been fixed.
367 =head1 Acknowledgements
369 Perl 5.21.11 represents approximately 4 weeks of development since Perl 5.21.10
370 and contains approximately 5,800 lines of changes across 240 files from 24
373 Excluding auto-generated files, documentation and release tools, there were
374 approximately 1,700 lines of changes to 160 .pm, .t, .c and .h files.
376 Perl continues to flourish into its third decade thanks to a vibrant community
377 of users and developers. The following people are known to have contributed
378 the improvements that became Perl 5.21.11:
380 Alex Vandiver, Andreas König, Craig A. Berry, Dagfinn Ilmari Mannsåker, Daniel
381 Dragan, David Golden, David Mitchell, Father Chrysostomos, H.Merijn Brand,
382 Herbert Breunung, Hugo van der Sanden, James E Keenan, James McCoy, Karl
383 Williamson, Matthew Horsfall, Max Maischein, Nicholas Clark, Rafael
384 Garcia-Suarez, Randy Stauner, Ricardo Signes, Shirakata Kentaro, Steffen
385 Müller, Steve Hay, Tony Cook.
387 The list above is almost certainly incomplete as it is automatically generated
388 from version control history. In particular, it does not include the names of
389 the (very much appreciated) contributors who reported issues to the Perl bug
392 Many of the changes included in this version originated in the CPAN modules
393 included in Perl's core. We're grateful to the entire CPAN community for
394 helping Perl to flourish.
396 For a more complete list of all of Perl's historical contributors, please see
397 the F<AUTHORS> file in the Perl source distribution.
399 =head1 Reporting Bugs
401 If you find what you think is a bug, you might check the articles recently
402 posted to the comp.lang.perl.misc newsgroup and the perl bug database at
403 https://rt.perl.org/ . There may also be information at
404 http://www.perl.org/ , the Perl Home Page.
406 If you believe you have an unreported bug, please run the L<perlbug> program
407 included with your release. Be sure to trim your bug down to a tiny but
408 sufficient test case. Your bug report, along with the output of C<perl -V>,
409 will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
411 If the bug you are reporting has security implications, which make it
412 inappropriate to send to a publicly archived mailing list, then please send it
413 to perl5-security-report@perl.org. This points to a closed subscription
414 unarchived mailing list, which includes all the core committers, who will be
415 able to help assess the impact of issues, figure out a resolution, and help
416 co-ordinate the release of patches to mitigate or fix the problem across all
417 platforms on which Perl is supported. Please only use this address for
418 security issues in the Perl core, not for modules independently distributed on
423 The F<Changes> file for an explanation of how to view exhaustive details on
426 The F<INSTALL> file for how to build Perl.
428 The F<README> file for general stuff.
430 The F<Artistic> and F<Copying> files for copyright information.