5 perl5260delta - what is new for perl v5.26.0
9 This document describes the differences between the 5.24.0 release and the
14 This release includes three updates with widespread effects:
18 =item * C<"."> no longer in C<@INC>
20 For security reasons, the current directory (C<".">) is no longer included
21 by default at the end of the module search path (C<@INC>). This may have
22 widespread implications for the building, testing and installing of
23 modules, and for the execution of scripts. See the section
24 L<< Removal of the current directory (C<".">) from C<@INC> >>
27 =item * C<do> may now warn
29 C<do> now gives a deprecation warning when it fails to load a file which
30 it would have loaded had C<"."> been in C<@INC>.
32 =item * In regular expression patterns, a literal left brace C<"{">
35 See L</Unescaped literal C<"{"> characters in regular expression patterns are no longer permissible>.
39 =head1 Core Enhancements
41 =head2 Lexical subroutines are no longer experimental
43 Using the C<lexical_subs> feature introduced in v5.18 no longer emits a warning. Existing
44 code that disables the C<experimental::lexical_subs> warning category
45 that the feature previously used will continue to work. The
46 C<lexical_subs> feature has no effect; all Perl code can use lexical
47 subroutines, regardless of what feature declarations are in scope.
49 =head2 Indented Here-documents
51 This adds a new modifier C<"~"> to here-docs that tells the parser
52 that it should look for C</^\s*$DELIM\n/> as the closing delimiter.
54 These syntaxes are all supported:
65 The C<"~"> modifier will strip, from each line in the here-doc, the
66 same whitespace that appears before the delimiter.
68 Newlines will be copied as-is, and lines that don't include the
69 proper beginning whitespace will cause perl to croak.
79 prints "Hello there\n" with no leading whitespace.
81 =head2 New regular expression modifier C</xx>
83 Specifying two C<"x"> characters to modify a regular expression pattern
84 does everything that a single one does, but additionally TAB and SPACE
85 characters within a bracketed character class are generally ignored and
86 can be added to improve readability, like
87 S<C</[ ^ A-Z d-f p-x ]/xx>>. Details are at
88 L<perlre/E<sol>x and E<sol>xx>.
90 =head2 C<@{^CAPTURE}>, C<%{^CAPTURE}>, and C<%{^CAPTURE_ALL}>
92 C<@{^CAPTURE}> exposes the capture buffers of the last match as an
93 array. So C<$1> is C<${^CAPTURE}[0]>. This is a more efficient equivalent
94 to code like C<substr($matched_string,$-[0],$+[0]-$-[0])>, and you don't
95 have to keep track of the C<$matched_string> either. This variable has no
96 single character equivalent. Note that, like the other regex magic variables,
97 the contents of this variable is dynamic; if you wish to store it beyond
98 the lifetime of the match you must copy it to another array.
100 C<%{^CAPTURE}> is equivalent to C<%+> (I<i.e.>, named captures). Other than
101 being more self-documenting there is no difference between the two forms.
103 C<%{^CAPTURE_ALL}> is equivalent to C<%-> (I<i.e.>, all named captures).
104 Other than being more self-documenting there is no difference between the
107 =head2 Declaring a reference to a variable
109 As an experimental feature, Perl now allows the referencing operator to come
110 after L<C<my()>|perlfunc/my>, L<C<state()>|perlfunc/state>,
111 L<C<our()>|perlfunc/our>, or L<C<local()>|perlfunc/local>. This syntax must
112 be enabled with C<use feature 'declared_refs'>. It is experimental, and will
113 warn by default unless C<no warnings 'experimental::refaliasing'> is in effect.
114 It is intended mainly for use in assignments to references. For example:
116 use experimental 'refaliasing', 'declared_refs';
119 See L<perlref/Assigning to References> for more details.
121 =head2 Unicode 9.0 is now supported
123 A list of changes is at L<http://www.unicode.org/versions/Unicode9.0.0/>.
124 Modules that are shipped with core Perl but not maintained by p5p do not
125 necessarily support Unicode 9.0. L<Unicode::Normalize> does work on 9.0.
127 =head2 Use of C<\p{I<script>}> uses the improved Script_Extensions property
129 Unicode 6.0 introduced an improved form of the Script (C<sc>) property, and
130 called it Script_Extensions (C<scx>). Perl now uses this improved
131 version when a property is specified as just C<\p{I<script>}>. This
132 should make programs more accurate when determining if a character is
133 used in a given script, but there is a slight chance of breakage for
134 programs that very specifically needed the old behavior. The meaning of
135 compound forms, like C<\p{sc=I<script>}> are unchanged. See
136 L<perlunicode/Scripts>.
138 =head2 Perl can now do default collation in UTF-8 locales on platforms
141 Some platforms natively do a reasonable job of collating and sorting in
142 UTF-8 locales. Perl now works with those. For portability and full
143 control, L<Unicode::Collate> is still recommended, but now you may
144 not need to do anything special to get good-enough results, depending on
145 your application. See
146 L<perllocale/Category C<LC_COLLATE>: Collation: Text Comparisons and Sorting>.
148 =head2 Better locale collation of strings containing embedded C<NUL>
151 In locales that have multi-level character weights, C<NUL>s are now
152 ignored at the higher priority ones. There are still some gotchas in
153 some strings, though. See
154 L<perllocale/Collation of strings containing embedded C<NUL> characters>.
156 =head2 C<CORE> subroutines for hash and array functions callable via
159 The hash and array functions in the C<CORE> namespace (C<keys>, C<each>,
160 C<values>, C<push>, C<pop>, C<shift>, C<unshift> and C<splice>) can now
161 be called with ampersand syntax (C<&CORE::keys(\%hash>) and via reference
162 (C<< my $k = \&CORE::keys; $k-E<gt>(\%hash) >>). Previously they could only be
165 =head2 New Hash Function For 64-bit Builds
167 We have switched to a hybrid hash function to better balance
168 performance for short and long keys.
170 For short keys, 16 bytes and under, we use an optimised variant of
171 One At A Time Hard, and for longer keys we use Siphash 1-3. For very
172 long keys this is a big improvement in performance. For shorter keys
173 there is a modest improvement.
177 =head2 Removal of the current directory (C<".">) from C<@INC>
179 The perl binary includes a default set of paths in C<@INC>. Historically
180 it has also included the current directory (C<".">) as the final entry,
181 unless run with taint mode enabled (C<perl -T>). While convenient, this has
182 security implications: for example, where a script attempts to load an
183 optional module when its current directory is untrusted (such as F</tmp>),
184 it could load and execute code from under that directory.
186 Starting with v5.26, C<"."> is always removed by default, not just under
187 tainting. This has major implications for installing modules and executing
190 The following new features have been added to help ameliorate these
195 =item * F<Configure -Udefault_inc_excludes_dot>
197 There is a new F<Configure> option, C<default_inc_excludes_dot> (enabled
198 by default) which builds a perl executable without C<".">; unsetting this
199 option using C<-U> reverts perl to the old behaviour. This may fix your
200 path issues but will reintroduce all the security concerns, so don't
201 build a perl executable like this unless you're I<really> confident that
202 such issues are not a concern in your environment.
204 =item * C<PERL_USE_UNSAFE_INC>
206 There is a new environment variable recognised by the perl interpreter.
207 If this variable has the value 1 when the perl interpreter starts up,
208 then C<"."> will be automatically appended to C<@INC> (except under tainting).
210 This allows you restore the old perl interpreter behaviour on a
211 case-by-case basis. But note that this is intended to be a temporary crutch,
212 and this feature will likely be removed in some future perl version.
213 It is currently set by the C<cpan> utility and C<Test::Harness> to
214 ease installation of CPAN modules which have not been updated to handle the
215 lack of dot. Once again, don't use this unless you are sure that this
216 will not reintroduce any security concerns.
218 =item * A new deprecation warning issued by C<do>.
220 While it is well-known that C<use> and C<require> use C<@INC> to search
221 for the file to load, many people don't realise that C<do "file"> also
222 searches C<@INC> if the file is a relative path. With the removal of C<".">,
223 a simple C<do "file.pl"> will fail to read in and execute C<file.pl> from
224 the current directory. Since this is commonly expected behaviour, a new
225 deprecation warning is now issued whenever C<do> fails to load a file which
226 it otherwise would have found if a dot had been in C<@INC>.
230 Here are some things script and module authors may need to do to make
231 their software work in the new regime.
235 =item * Script authors
237 If the issue is within your own code (rather than within included
238 modules), then you have two main options. Firstly, if you are confident
239 that your script will only be run within a trusted directory (under which
240 you expect to find trusted files and modules), then add C<"."> back into the
244 my $dir = "/some/trusted/directory";
245 chdir $dir or die "Can't chdir to $dir: $!\n";
250 use "Foo::Bar"; # may load /some/trusted/directory/Foo/Bar.pm
251 do "config.pl"; # may load /some/trusted/directory/config.pl
253 On the other hand, if your script is intended to be run from within
254 untrusted directories (such as F</tmp>), then your script suddenly failing
255 to load files may be indicative of a security issue. You most likely want
256 to replace any relative paths with full paths; for example,
262 do "$ENV{HOME}/foo_config.pl"
264 If you are absolutely certain that you want your script to load and
265 execute a file from the current directory, then use a C<./> prefix; for
270 =item * Installing and using CPAN modules
272 If you install a CPAN module using an automatic tool like C<cpan>, then
273 this tool will itself set the C<PERL_USE_UNSAFE_INC> environment variable
274 while building and testing the module, which may be sufficient to install
275 a distribution which hasn't been updated to be dot-aware. If you want to
276 install such a module manually, then you'll need to replace the
277 traditional invocation:
279 perl Makefile.PL && make && make test && make install
283 (export PERL_USE_UNSAFE_INC=1; \
284 perl Makefile.PL && make && make test && make install)
286 Note that this only helps build and install an unfixed module. It's
287 possible for the tests to pass (since they were run under
288 C<PERL_USE_UNSAFE_INC=1>), but for the module itself to fail to perform
289 correctly in production. In this case, you may have to temporarily modify
290 your script until a fixed version of the module is released.
295 local @INC = (@INC, '.');
296 # assuming read_config() needs '.' in @INC
297 $config = Foo::Bar->read_config();
300 This is only rarely expected to be necessary. Again, if doing this,
301 assess the resultant risks first.
303 =item * Module Authors
305 If you maintain a CPAN distribution, it may need updating to run in
306 a dotless environment. Although C<cpan> and other such tools will
307 currently set the C<PERL_USE_UNSAFE_INC> during module build, this is a
308 temporary workaround for the set of modules which rely on C<"."> being in
309 C<@INC> for installation and testing, and this may mask deeper issues. It
310 could result in a module which passes tests and installs, but which
313 During build, test, and install, it will normally be the case that any perl
314 processes will be executing directly within the root directory of the
315 untarred distribution, or a known subdirectory of that, such as F<t/>. It
316 may well be that F<Makefile.PL> or F<t/foo.t> will attempt to include
317 local modules and configuration files using their direct relative
318 filenames, which will now fail.
320 However, as described above, automatic tools like F<cpan> will (for now)
321 set the C<PERL_USE_UNSAFE_INC> environment variable, which introduces
324 This makes it likely that your existing build and test code will work, but
325 this may mask issues with your code which only manifest when used after
326 install. It is prudent to try and run your build process with that
327 variable explicitly disabled:
329 (export PERL_USE_UNSAFE_INC=0; \
330 perl Makefile.PL && make && make test && make install)
332 This is more likely to show up any potential problems with your module's
333 build process, or even with the module itself. Fixing such issues will
334 ensure both that your module can again be installed manually, and that
335 it will still build once the C<PERL_USE_UNSAFE_INC> crutch goes away.
337 When fixing issues in tests due to the removal of dot from C<@INC>,
338 reinsertion of dot into C<@INC> should be performed with caution, for this
339 too may suppress real errors in your runtime code. You are encouraged
340 wherever possible to apply the aforementioned approaches with explicit
341 absolute/relative paths, or to relocate your needed files into a
342 subdirectory and insert that subdirectory into C<@INC> instead.
344 If your runtime code has problems under the dotless C<@INC>, then the comments
345 above on how to fix for script authors will mostly apply here too. Bear in
346 mind though that it is considered bad form for a module to globally add a dot to
347 C<@INC>, since it introduces both a security risk and hides issues of
348 accidentally requiring dot in C<@INC>, as explained above.
352 =head2 Escaped colons and relative paths in PATH
354 On Unix systems, Perl treats any relative paths in the C<PATH> environment
355 variable as tainted when starting a new process. Previously, it was
356 allowing a backslash to escape a colon (unlike the OS), consequently
357 allowing relative paths to be considered safe if the PATH was set to
358 something like C</\:.>. The check has been fixed to treat C<"."> as tainted
361 =head2 New C<-Di> switch is now required for PerlIO debugging output
363 This is used for debugging of code within PerlIO to avoid recursive
364 calls. Previously this output would be sent to the file specified
365 by the C<PERLIO_DEBUG> environment variable if perl wasn't running
366 setuid and the C<-T> or C<-t> switches hadn't been parsed yet.
368 If perl performed output at a point where it hadn't yet parsed its
369 switches this could result in perl creating or overwriting the file
370 named by C<PERLIO_DEBUG> even when the C<-T> switch had been supplied.
372 Perl now requires the C<-Di> switch to be present before it will produce
374 output. By default this is written to C<stderr>, but can optionally
375 be redirected to a file by setting the C<PERLIO_DEBUG> environment
378 If perl is running setuid or the C<-T> switch was supplied,
379 C<PERLIO_DEBUG> is ignored and the debugging output is sent to
380 C<stderr> as for any other C<-D> switch.
382 =head1 Incompatible Changes
384 =head2 Unescaped literal C<"{"> characters in regular expression
385 patterns are no longer permissible
387 You have to now say something like C<"\{"> or C<"[{]"> to specify to
388 match a LEFT CURLY BRACKET; otherwise, it is a fatal pattern compilation
389 error. This change will allow future extensions to the language.
391 These have been deprecated since v5.16, with a deprecation message
392 raised for some uses starting in v5.22. Unfortunately, the code added
393 to raise the message was buggy and failed to warn in some cases where
394 it should have. Therefore, enforcement of this ban for these cases is
395 deferred until Perl 5.30, but the code has been fixed to raise a
396 default-on deprecation message for them in the meantime.
398 Some uses of literal C<"{"> occur in contexts where we do not foresee
399 the meaning ever being anything but the literal, such as the very first
400 character in the pattern, or after a C<"|"> meaning alternation. Thus
404 matches either of the strings C<{fee> or C<{fie>. To avoid forcing
405 unnecessary code changes, these uses do not need to be escaped, and no
406 warning is raised about them, and there are no current plans to change this.
408 But it is always correct to escape C<"{">, and the simple rule to
409 remember is to always do so.
411 See L<Unescaped left brace in regex is illegal here|perldiag/Unescaped left brace in regex is illegal here in regex; marked by S<E<lt>-- HERE> in mE<sol>%sE<sol>>.
413 =head2 C<scalar(%hash)> return signature changed
415 The value returned for C<scalar(%hash)> will no longer show information about
416 the buckets allocated in the hash. It will simply return the count of used
417 keys. It is thus equivalent to C<0+keys(%hash)>.
419 A form of backward compatibility is provided via
420 L<C<Hash::Util::bucket_ratio()>|Hash::Util/bucket_ratio> which provides
422 C<scalar(%hash)> provided in Perl 5.24 and earlier.
424 =head2 C<keys> returned from an lvalue subroutine
426 C<keys> returned from an lvalue subroutine can no longer be assigned
429 sub foo : lvalue { keys(%INC) }
431 sub bar : lvalue { keys(@_) }
432 (bar) = 3; # also an error
434 This makes the lvalue sub case consistent with C<(keys %hash) = ...> and
435 C<(keys @_) = ...>, which are also errors.
436 L<[perl #128187]|https://rt.perl.org/Public/Bug/Display.html?id=128187>
438 =head2 The C<${^ENCODING}> facility has been removed
440 The special behaviour associated with assigning a value to this variable
441 has been removed. As a consequence, the L<encoding> pragma's default mode
442 is no longer supported. If
443 you still need to write your source code in encodings other than UTF-8, use a
444 source filter such as L<Filter::Encoding> on CPAN or L<encoding>'s C<Filter>
447 =head2 C<POSIX::tmpnam()> has been removed
449 The fundamentally unsafe C<tmpnam()> interface was deprecated in
450 Perl 5.22 and has now been removed. In its place, you can use,
451 for example, the L<File::Temp> interfaces.
453 =head2 require ::Foo::Bar is now illegal.
455 Formerly, C<require ::Foo::Bar> would try to read F</Foo/Bar.pm>. Now any
456 bareword require which starts with a double colon dies instead.
458 =head2 Literal control character variable names are no longer permissible
460 A variable name may no longer contain a literal control character under
461 any circumstances. These previously were allowed in single-character
462 names on ASCII platforms, but have been deprecated there since Perl
463 5.20. This affects things like C<$I<\cT>>, where I<\cT> is a literal
464 control (such as a C<NAK> or C<NEGATIVE ACKNOWLEDGE> character) in the
467 =head2 C<NBSP> is no longer permissible in C<\N{...}>
469 The name of a character may no longer contain non-breaking spaces. It
470 has been deprecated to do so since Perl 5.22.
474 =head2 String delimiters that aren't stand-alone graphemes are now deprecated
476 For Perl to eventually allow string delimiters to be Unicode
477 grapheme clusters (which look like a single character, but may be
478 a sequence of several ones), we have to stop allowing a single character
479 delimiter that isn't a grapheme by itself. These are unlikely to exist
480 in actual code, as they would typically display as attached to the
481 character in front of them.
483 =head2 C<\cI<X>> that maps to a printable is no longer deprecated
485 This means we have no plans to remove this feature. It still raises a
486 warning, but only if syntax warnings are enabled. The feature was
487 originally intended to be a way to express non-printable characters that
488 don't have a mnemonic (C<\t> and C<\n> are mnemonics for two
489 non-printable characters, but most non-printables don't have a
490 mnemonic.) But the feature can be used to specify a few printable
491 characters, though those are more clearly expressed as the printable
493 L<http://www.nntp.perl.org/group/perl.perl5.porters/2017/02/msg242944.html>.
495 =head1 Performance Enhancements
501 A hash in boolean context is now sometimes faster, I<e.g.>
505 This was already special-cased, but some cases were missed (such as
506 C<grep %$_, @AoH>), and even the ones which weren't have been improved.
508 =item * New Faster Hash Function on 64 bit builds
510 We use a different hash function for short and long keys. This should
511 improve performance and security, especially for long keys.
513 =item * readline is faster
515 Reading from a file line-by-line with C<readline()> or C<< E<lt>E<gt> >> should
516 now typically be faster due to a better implementation of the code that
517 searches for the next newline character.
521 Assigning one reference to another, I<e.g.> C<$ref1 = $ref2> has been
522 optimized in some cases.
526 Remove some exceptions to creating Copy-on-Write strings. The string
527 buffer growth algorithm has been slightly altered so that you're less
528 likely to encounter a string which can't be COWed.
532 Better optimise array and hash assignment: where an array or hash appears
533 in the LHS of a list assignment, such as C<(..., @a) = (...);>, it's
534 likely to be considerably faster, especially if it involves emptying the
535 array/hash. For example, this code runs about a third faster compared to
539 for my $i (1..10_000_000) {
546 Converting a single-digit string to a number is now substantially faster.
550 The C<split> builtin is now slightly faster in many cases: in particular
551 for the two specially-handled forms
554 local @a = split ...;
558 The rather slow implementation for the experimental subroutine signatures
559 feature has been made much faster; it is now comparable in speed with the
560 traditional C<my ($a, $b, @c) = @_>.
564 Bareword constant strings are now permitted to take part in constant
565 folding. They were originally exempted from constant folding in August 1999,
566 during the development of Perl 5.6, to ensure that C<use strict "subs">
567 would still apply to bareword constants. That has now been accomplished a
568 different way, so barewords, like other constants, now gain the performance
569 benefits of constant folding.
571 This also means that void-context warnings on constant expressions of
572 barewords now report the folded constant operand, rather than the operation;
573 this matches the behaviour for non-bareword constants.
577 =head1 Modules and Pragmata
579 =head2 Updated Modules and Pragmata
585 IO::Compress has been upgraded from version 2.069 to 2.074.
589 L<Archive::Tar> has been upgraded from version 2.04 to 2.24.
593 L<arybase> has been upgraded from version 0.11 to 0.12.
597 L<attributes> has been upgraded from version 0.27 to 0.29.
599 The deprecation message for the C<:unique> and C<:locked> attributes
600 now mention that they will disappear in Perl 5.28.
604 L<B> has been upgraded from version 1.62 to 1.68.
608 L<B::Concise> has been upgraded from version 0.996 to 0.999.
610 Its output is now more descriptive for C<op_private> flags.
614 L<B::Debug> has been upgraded from version 1.23 to 1.24.
618 L<B::Deparse> has been upgraded from version 1.37 to 1.40.
622 L<B::Xref> has been upgraded from version 1.05 to 1.06.
624 It now uses 3-arg C<open()> instead of 2-arg C<open()>.
625 L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
629 L<base> has been upgraded from version 2.23 to 2.25.
633 L<bignum> has been upgraded from version 0.42 to 0.47.
637 L<Carp> has been upgraded from version 1.40 to 1.42.
641 L<charnames> has been upgraded from version 1.43 to 1.44.
645 L<Compress::Raw::Bzip2> has been upgraded from version 2.069 to 2.074.
649 L<Compress::Raw::Zlib> has been upgraded from version 2.069 to 2.074.
653 L<Config::Perl::V> has been upgraded from version 0.25 to 0.28.
657 L<CPAN> has been upgraded from version 2.11 to 2.18.
661 L<CPAN::Meta> has been upgraded from version 2.150005 to 2.150010.
665 L<Data::Dumper> has been upgraded from version 2.160 to 2.167.
667 The XS implementation now supports Deparse.
671 L<DB_File> has been upgraded from version 1.835 to 1.840.
675 L<Devel::Peek> has been upgraded from version 1.23 to 1.26.
679 L<Devel::PPPort> has been upgraded from version 3.32 to 3.35.
683 L<Devel::SelfStubber> has been upgraded from version 1.05 to 1.06.
685 It now uses 3-arg C<open()> instead of 2-arg C<open()>.
686 L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
690 L<diagnostics> has been upgraded from version 1.34 to 1.36.
692 It now uses 3-arg C<open()> instead of 2-arg C<open()>.
693 L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
697 L<Digest> has been upgraded from version 1.17 to 1.17_01.
701 L<Digest::MD5> has been upgraded from version 2.54 to 2.55.
705 L<Digest::SHA> has been upgraded from version 5.95 to 5.96.
709 L<DynaLoader> has been upgraded from version 1.38 to 1.42.
713 L<Encode> has been upgraded from version 2.80 to 2.88.
717 L<encoding> has been upgraded from version 2.17 to 2.19.
719 This module's default mode is no longer supported. It now
720 dies when imported, unless the C<Filter> option is being used.
724 L<encoding::warnings> has been upgraded from version 0.12 to 0.13.
726 This module is no longer supported. It emits a warning to
727 that effect and then does nothing.
731 L<Errno> has been upgraded from version 1.25 to 1.28.
733 It now documents that using C<%!> automatically loads Errno for you.
735 It now uses 3-arg C<open()> instead of 2-arg C<open()>.
736 L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
740 L<ExtUtils::Embed> has been upgraded from version 1.33 to 1.34.
742 It now uses 3-arg C<open()> instead of 2-arg C<open()>.
743 L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
747 L<ExtUtils::MakeMaker> has been upgraded from version 7.10_01 to 7.24.
751 L<ExtUtils::Miniperl> has been upgraded from version 1.05 to 1.06.
755 L<ExtUtils::ParseXS> has been upgraded from version 3.31 to 3.34.
759 L<ExtUtils::Typemaps> has been upgraded from version 3.31 to 3.34.
763 L<feature> has been upgraded from version 1.42 to 1.47.
767 L<File::Copy> has been upgraded from version 2.31 to 2.32.
771 L<File::Fetch> has been upgraded from version 0.48 to 0.52.
775 L<File::Glob> has been upgraded from version 1.26 to 1.28.
777 It now Issues a deprecation message for C<File::Glob::glob()>.
781 L<File::Spec> has been upgraded from version 3.63 to 3.67.
785 L<FileHandle> has been upgraded from version 2.02 to 2.03.
789 L<Filter::Simple> has been upgraded from version 0.92 to 0.93.
791 It no longer treats C<no MyFilter> immediately following C<use MyFilter> as
793 L<[perl #107726]|https://rt.perl.org/Public/Bug/Display.html?id=107726>
797 L<Getopt::Long> has been upgraded from version 2.48 to 2.49.
801 L<Getopt::Std> has been upgraded from version 1.11 to 1.12.
805 L<Hash::Util> has been upgraded from version 0.19 to 0.22.
809 L<HTTP::Tiny> has been upgraded from version 0.056 to 0.070.
811 Internal 599-series errors now include the redirect history.
815 L<I18N::LangTags> has been upgraded from version 0.40 to 0.42.
817 It now uses 3-arg C<open()> instead of 2-arg C<open()>.
818 L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
822 L<IO> has been upgraded from version 1.36 to 1.38.
826 L<IO::Socket::IP> has been upgraded from version 0.37 to 0.38.
830 L<IPC::Cmd> has been upgraded from version 0.92 to 0.96.
834 L<IPC::SysV> has been upgraded from version 2.06_01 to 2.07.
838 L<JSON::PP> has been upgraded from version 2.27300 to 2.27400_02.
842 L<lib> has been upgraded from version 0.63 to 0.64.
844 It now uses 3-arg C<open()> instead of 2-arg C<open()>.
845 L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
849 L<List::Util> has been upgraded from version 1.42_02 to 1.46_02.
853 L<Locale::Codes> has been upgraded from version 3.37 to 3.42.
857 L<Locale::Maketext> has been upgraded from version 1.26 to 1.28.
861 L<Locale::Maketext::Simple> has been upgraded from version 0.21 to 0.21_01.
865 L<Math::BigInt> has been upgraded from version 1.999715 to 1.999806.
869 L<Math::BigInt::FastCalc> has been upgraded from version 0.40 to 0.5005.
873 L<Math::BigRat> has been upgraded from version 0.260802 to 0.2611.
877 L<Math::Complex> has been upgraded from version 1.59 to 1.5901.
881 L<Memoize> has been upgraded from version 1.03 to 1.03_01.
885 L<Module::CoreList> has been upgraded from version 5.20170420 to 5.20170530.
889 L<Module::Load::Conditional> has been upgraded from version 0.64 to 0.68.
893 L<Module::Metadata> has been upgraded from version 1.000031 to 1.000033.
897 L<mro> has been upgraded from version 1.18 to 1.20.
901 L<Net::Ping> has been upgraded from version 2.43 to 2.55.
903 IPv6 addresses and C<AF_INET6> sockets are now supported, along with several
908 L<NEXT> has been upgraded from version 0.65 to 0.67.
912 L<Opcode> has been upgraded from version 1.34 to 1.39.
916 L<open> has been upgraded from version 1.10 to 1.11.
920 L<OS2::Process> has been upgraded from version 1.11 to 1.12.
922 It now uses 3-arg C<open()> instead of 2-arg C<open()>.
923 L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
927 L<overload> has been upgraded from version 1.26 to 1.28.
929 Its compilation speed has been improved slightly.
933 L<parent> has been upgraded from version 0.234 to 0.236.
937 L<perl5db.pl> has been upgraded from version 1.50 to 1.51.
939 It now ignores F</dev/tty> on non-Unix systems.
940 L<[perl #113960]|https://rt.perl.org/Public/Bug/Display.html?id=113960>
944 L<Perl::OSType> has been upgraded from version 1.009 to 1.010.
948 L<perlfaq> has been upgraded from version 5.021010 to 5.021011.
952 L<PerlIO> has been upgraded from version 1.09 to 1.10.
956 L<PerlIO::encoding> has been upgraded from version 0.24 to 0.25.
960 L<PerlIO::scalar> has been upgraded from version 0.24 to 0.26.
964 L<Pod::Checker> has been upgraded from version 1.60 to 1.73.
968 L<Pod::Functions> has been upgraded from version 1.10 to 1.11.
972 L<Pod::Html> has been upgraded from version 1.22 to 1.2202.
976 L<Pod::Perldoc> has been upgraded from version 3.25_02 to 3.28.
980 L<Pod::Simple> has been upgraded from version 3.32 to 3.35.
984 L<Pod::Usage> has been upgraded from version 1.68 to 1.69.
988 L<POSIX> has been upgraded from version 1.65 to 1.76.
990 This remedies several defects in making its symbols exportable.
991 L<[perl #127821]|https://rt.perl.org/Public/Bug/Display.html?id=127821>
993 The C<POSIX::tmpnam()> interface has been removed,
994 see L</"POSIX::tmpnam() has been removed">.
996 The following deprecated functions have been removed:
1012 Trying to import POSIX subs that have no real implementations
1013 (like C<POSIX::atend()>) now fails at import time, instead of
1014 waiting until runtime.
1018 L<re> has been upgraded from version 0.32 to 0.34
1020 This adds support for the new L<C<E<47>xx>|perlre/E<sol>x and E<sol>xx>
1021 regular expression pattern modifier, and a change to the L<S<C<use re
1022 'strict'>>|re/'strict' mode> experimental feature. When S<C<re
1023 'strict'>> is enabled, a warning now will be generated for all
1024 unescaped uses of the two characters C<"}"> and C<"]"> in regular
1025 expression patterns (outside bracketed character classes) that are taken
1026 literally. This brings them more in line with the C<")"> character which
1027 is always a metacharacter unless escaped. Being a metacharacter only
1028 sometimes, depending on an action at a distance, can lead to silently
1029 having the pattern mean something quite different than was intended,
1030 which the S<C<re 'strict'>> mode is intended to minimize.
1034 L<Safe> has been upgraded from version 2.39 to 2.40.
1038 L<Scalar::Util> has been upgraded from version 1.42_02 to 1.46_02.
1042 L<Storable> has been upgraded from version 2.56 to 2.62.
1045 L<[perl #130098]|https://rt.perl.org/Public/Bug/Display.html?id=130098>.
1049 L<Symbol> has been upgraded from version 1.07 to 1.08.
1053 L<Sys::Syslog> has been upgraded from version 0.33 to 0.35.
1057 L<Term::ANSIColor> has been upgraded from version 4.04 to 4.06.
1061 L<Term::ReadLine> has been upgraded from version 1.15 to 1.16.
1063 It now uses 3-arg C<open()> instead of 2-arg C<open()>.
1064 L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
1068 L<Test> has been upgraded from version 1.28 to 1.30.
1070 It now uses 3-arg C<open()> instead of 2-arg C<open()>.
1071 L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
1075 L<Test::Harness> has been upgraded from version 3.36 to 3.38.
1079 L<Test::Simple> has been upgraded from version 1.001014 to 1.302073.
1083 L<Thread::Queue> has been upgraded from version 3.09 to 3.12.
1087 L<Thread::Semaphore> has been upgraded from 2.12 to 2.13.
1089 Added the C<down_timed> method.
1093 L<threads> has been upgraded from version 2.07 to 2.15.
1097 L<threads::shared> has been upgraded from version 1.51 to 1.56.
1101 L<Tie::Hash::NamedCapture> has been upgraded from version 0.09 to 0.10.
1105 L<Time::HiRes> has been upgraded from version 1.9733 to 1.9741.
1107 It now builds on systems with C++11 compilers (such as G++ 6 and Clang++
1110 Now uses C<clockid_t>.
1114 L<Time::Local> has been upgraded from version 1.2300 to 1.25.
1118 L<Unicode::Collate> has been upgraded from version 1.14 to 1.19.
1122 L<Unicode::UCD> has been upgraded from version 0.64 to 0.68.
1124 It now uses 3-arg C<open()> instead of 2-arg C<open()>.
1125 L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
1129 L<version> has been upgraded from version 0.9916 to 0.9917.
1133 L<VMS::DCLsym> has been upgraded from version 1.06 to 1.08.
1135 It now uses 3-arg C<open()> instead of 2-arg C<open()>.
1136 L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
1140 L<warnings> has been upgraded from version 1.36 to 1.37.
1144 L<XS::Typemap> has been upgraded from version 0.14 to 0.15.
1148 L<XSLoader> has been upgraded from version 0.21 to 0.27.
1150 Fixed a security hole in which binary files could be loaded from a path
1151 outside of L<C<@INC>|perlvar/@INC>.
1153 It now uses 3-arg C<open()> instead of 2-arg C<open()>.
1154 L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
1158 =head1 Documentation
1160 =head2 New Documentation
1162 =head3 L<perldeprecation>
1164 This file documents all upcoming deprecations, and some of the deprecations
1165 which already have been removed. The purpose of this documentation is
1166 two-fold: document what will disappear, and by which version, and serve
1167 as a guide for people dealing with code which has features that no longer
1168 work after an upgrade of their perl.
1170 =head2 Changes to Existing Documentation
1172 We have attempted to update the documentation to reflect the changes
1173 listed in this document. If you find any we have missed, send email to
1174 L<perlbug@perl.org|mailto:perlbug@perl.org>.
1176 Additionally, all references to Usenet have been removed, and the
1177 following selected changes have been made:
1185 Removed obsolete text about L<C<defined()>|perlfunc/defined>
1186 on aggregates that should have been deleted earlier, when the feature
1191 Corrected documentation of L<C<eval()>|perlfunc/eval>,
1192 and L<C<evalbytes()>|perlfunc/evalbytes>.
1196 Clarified documentation of L<C<seek()>|perlfunc/seek>,
1197 L<C<tell()>|perlfunc/tell> and L<C<sysseek()>|perlfunc/sysseek>
1198 emphasizing that positions are in bytes and not characters.
1199 L<[perl #128607]|https://rt.perl.org/Public/Bug/Display.html?id=128607>
1203 Clarified documentation of L<C<sort()>|perlfunc/sort LIST> concerning
1204 the variables C<$a> and C<$b>.
1208 In L<C<split()>|perlfunc/split> noted that certain pattern modifiers are
1209 legal, and added a caution about its use in Perls before v5.11.
1213 Removed obsolete documentation of L<C<study()>|perlfunc/study>, noting
1214 that it is now a no-op.
1218 Noted that L<C<vec()>|perlfunc/vec> doesn't work well when the string
1219 contains characters whose code points are above 255.
1230 L<formatted printing of operands of C<Size_t> and C<SSize_t>|perlguts/Formatted Printing of Size_t and SSize_t>
1240 Clarify what editor tab stop rules to use, and note that we are
1241 migrating away from using tabs, replacing them with sequences of SPACE
1246 =head3 L<perlhacktips>
1252 Give another reason to use C<cBOOL> to cast an expression to boolean.
1256 Note that the macros C<TRUE> and C<FALSE> are available to express
1261 =head3 L<perlinterp>
1267 L<perlinterp> has been expanded to give a more detailed example of how to
1268 hunt around in the parser for how a given operator is handled.
1272 =head3 L<perllocale>
1278 Some locales aren't compatible with Perl. Note that these can cause
1289 Various clarifications have been added.
1293 =head3 L<perlmodlib>
1299 Updated the site mirror list.
1309 Added a section on calling methods using their fully qualified names.
1313 Do not discourage manual C<@ISA>.
1323 Mention C<Moo> more.
1333 Note that white space must be used for quoting operators if the
1334 delimiter is a word character (I<i.e.>, matches C<\w>).
1338 Clarify that in regular expression patterns delimited by single quotes,
1339 no variable interpolation is done.
1349 The first part was extensively rewritten to incorporate various basic
1350 points, that in earlier versions were mentioned in sort of an appendix
1351 on Version 8 regular expressions.
1355 Note that it is common to have the C</x> modifier and forget that this
1356 means that C<"#"> has to be escaped.
1366 Add introductory material.
1370 Note that a metacharacter occurring in a context where it can't mean
1371 that, silently loses its meta-ness and matches literally.
1372 L<C<use re 'strict'>|re/'strict' mode> can catch some of these.
1376 =head3 L<perlunicode>
1382 Corrected the text about Unicode BYTE ORDER MARK handling.
1386 Updated the text to correspond with changes in Unicode UTS#18, concerning
1387 regular expressions, and Perl compatibility with what it says.
1397 Document C<@ISA>. It was documented in other places, but not in L<perlvar>.
1403 =head2 New Diagnostics
1411 L<A signature parameter must start with C<'$'>, C<'@'> or C<'%'>
1412 |perldiag/A signature parameter must start with C<'$'>, C<'@'> or C<'%'>>
1416 L<Bareword in require contains "%s"|perldiag/"Bareword in require contains "%s"">
1420 L<Bareword in require maps to empty filename|perldiag/"Bareword in require maps to empty filename">
1424 L<Bareword in require maps to disallowed filename "%s"|perldiag/"Bareword in require maps to disallowed filename "%s"">
1428 L<Bareword in require must not start with a double-colon: "%s"|perldiag/"Bareword in require must not start with a double-colon: "%s"">
1432 L<%s: command not found|perldiag/"%s: command not found">
1434 (A) You've accidentally run your script through B<bash> or another shell
1435 instead of Perl. Check the C<#!> line, or manually feed your script into
1436 Perl yourself. The C<#!> line at the top of your file could look like:
1442 L<%s: command not found: %s|perldiag/"%s: command not found: %s">
1444 (A) You've accidentally run your script through B<zsh> or another shell
1445 instead of Perl. Check the C<#!> line, or manually feed your script into
1446 Perl yourself. The C<#!> line at the top of your file could look like:
1452 L<The experimental declared_refs feature is not enabled|perldiag/"The experimental declared_refs feature is not enabled">
1454 (F) To declare references to variables, as in C<my \%x>, you must first enable
1457 no warnings "experimental::declared_refs";
1458 use feature "declared_refs";
1460 See L</Declaring a reference to a variable>.
1464 L<Illegal character following sigil in a subroutine signature
1465 |perldiag/Illegal character following sigil in a subroutine signature>
1469 L<Indentation on line %d of here-doc doesn't match delimiter
1470 |perldiag/Indentation on line %d of here-doc doesn't match delimiter>
1474 L<Infinite recursion via empty pattern|perldiag/"Infinite recursion via empty pattern">.
1476 Using the empty pattern (which re-executes the last successfully-matched
1477 pattern) inside a code block in another regex, as in C</(?{ s!!new! })/>, has
1478 always previously yielded a segfault. It now produces this error.
1482 L<Malformed UTF-8 string in "%s"
1483 |perldiag/Malformed UTF-8 string in "%s">
1487 L<Multiple slurpy parameters not allowed
1488 |perldiag/Multiple slurpy parameters not allowed>
1492 L<C<'#'> not allowed immediately following a sigil in a subroutine signature
1493 |perldiag/C<'#'> not allowed immediately following a sigil in a subroutine signature>
1497 L<panic: unknown OA_*: %x
1498 |perldiag/panic: unknown OA_*: %x>
1502 L<Unescaped left brace in regex is illegal here|perldiag/Unescaped left brace in regex is illegal here in regex; marked by S<E<lt>-- HERE> in mE<sol>%sE<sol>>
1504 Unescaped left braces are now illegal in some contexts in regular expression
1505 patterns. In other contexts, they are still just deprecated; they will
1506 be illegal in Perl 5.30.
1510 L<Version control conflict marker|perldiag/"Version control conflict marker">
1512 (F) The parser found a line starting with C<E<lt>E<lt>E<lt>E<lt>E<lt>E<lt>E<lt>>,
1513 C<E<gt>E<gt>E<gt>E<gt>E<gt>E<gt>E<gt>>, or C<=======>. These may be left by a
1514 version control system to mark conflicts after a failed merge operation.
1524 L<Can't determine class of operator %s, assuming C<BASEOP>
1525 |perldiag/Can't determine class of operator %s, assuming C<BASEOP>>
1529 L<Declaring references is experimental|perldiag/"Declaring references is experimental">
1531 (S experimental::declared_refs) This warning is emitted if you use a reference
1532 constructor on the right-hand side of C<my()>, C<state()>, C<our()>, or
1533 C<local()>. Simply suppress the warning if you want to use the feature, but
1534 know that in doing so you are taking the risk of using an experimental feature
1535 which may change or be removed in a future Perl version:
1537 no warnings "experimental::declared_refs";
1538 use feature "declared_refs";
1541 See L</Declaring a reference to a variable>.
1545 L<do "%s" failed, '.' is no longer in @INC|perldiag/do "%s" failed, '.' is no longer in @INC; did you mean do ".E<sol>%s"?>
1547 Since C<"."> is now removed from C<@INC> by default, C<do> will now trigger a warning recommending to fix the C<do> statement.
1551 L<C<File::Glob::glob()> will disappear in perl 5.30. Use C<File::Glob::bsd_glob()> instead.
1552 |perldiag/C<File::Glob::glob()> will disappear in perl 5.30. Use C<File::Glob::bsd_glob()> instead.>
1556 L<Unescaped literal '%c' in regex; marked by E<lt>-- HERE in mE<sol>%sE<sol>
1557 |perldiag/Unescaped literal '%c' in regex; marked by <-- HERE in mE<sol>%sE<sol>>
1561 L<Use of unassigned code point or non-standalone grapheme for a delimiter will be a fatal error starting in Perl 5.30|perldiag/"Use of unassigned code point or non-standalone grapheme for a delimiter will be a fatal error starting in Perl 5.30">
1563 See L</Deprecations>
1567 =head2 Changes to Existing Diagnostics
1573 When a C<require> fails, we now do not provide C<@INC> when the C<require>
1574 is for a file instead of a module.
1578 When C<@INC> is not scanned for a C<require> call, we no longer display
1579 C<@INC> to avoid confusion.
1583 L<Attribute "locked" is deprecated, and will disappear in Perl 5.28
1584 |perldiag/Attribute "locked" is deprecated, and will disappear in Perl 5.28>
1586 This existing warning has had the I<and will disappear> text added in this
1591 L<Attribute "unique" is deprecated, and will disappear in Perl 5.28
1592 |perldiag/Attribute "unique" is deprecated, and will disappear in Perl 5.28>
1594 This existing warning has had the I<and will disappear> text added in this
1599 Calling POSIX::%s() is deprecated
1601 This warning has been removed, as the deprecated functions have been
1606 L<Constants from lexical variables potentially modified elsewhere are deprecated. This will not be allowed in Perl 5.32
1607 |perldiag/Constants from lexical variables potentially modified elsewhere are deprecated. This will not be allowed in Perl 5.32>
1609 This existing warning has had the I<this will not be allowed> text added
1614 L<Deprecated use of C<my()> in false conditional. This will be a fatal error in Perl 5.30
1615 |perldiag/Deprecated use of C<my()> in false conditional. This will be a fatal error in Perl 5.30>
1617 This existing warning has had the I<this will be a fatal error> text added
1622 L<C<dump()> better written as C<CORE::dump()>. C<dump()> will no longer be available in Perl 5.30
1623 |perldiag/C<dump()> better written as C<CORE::dump()>. C<dump()> will no longer be available in Perl 5.30>
1625 This existing warning has had the I<no longer be available> text added in
1630 L<Experimental %s on scalar is now forbidden
1631 |perldiag/Experimental %s on scalar is now forbidden>
1633 This message is now followed by more helpful text.
1634 L<[perl #127976]|https://rt.perl.org/Public/Bug/Display.html?id=127976>
1638 Experimental "%s" subs not enabled
1640 This warning was been removed, as lexical subs are no longer experimental.
1644 Having more than one /%c regexp modifier is deprecated
1646 This deprecation warning has been removed, since C</xx> now has a new
1651 L<%s() is deprecated on C<:utf8> handles. This will be a fatal error in Perl 5.30
1652 |perldiag/%s() is deprecated on C<:utf8> handles. This will be a fatal error in Perl 5.30>.
1654 where "%s" is one of C<sysread>, C<recv>, C<syswrite>, or C<send>.
1656 This existing warning has had the I<this will be a fatal error> text added
1659 This warning is now enabled by default, as all C<deprecated> category
1664 L<C<$*> is no longer supported. Its use will be fatal in Perl 5.30
1665 |perldiag/C<$*> is no longer supported. Its use will be fatal in Perl 5.30>
1667 This existing warning has had the I<its use will be fatal> text added in
1672 L<C<$#> is no longer supported. Its use will be fatal in Perl 5.30
1673 |perldiag/C<$#> is no longer supported. Its use will be fatal in Perl 5.30>
1675 This existing warning has had the I<its use will be fatal> text added in
1680 L<Malformed UTF-8 character%s
1681 |perldiag/Malformed UTF-8 character%s>
1683 Details as to the exact problem have been added at the end of this
1688 L<Missing or undefined argument to %s
1689 |perldiag/Missing or undefined argument to %s>
1691 This warning used to warn about C<require>, even if it was actually C<do>
1692 which being executed. It now gets the operation name right.
1696 NO-BREAK SPACE in a charnames alias definition is deprecated
1698 This warning has been removed as the behavior is now an error.
1702 L<Odd nameE<sol>value argument for subroutine '%s'
1703 |perldiag/"Odd nameE<sol>value argument for subroutine '%s'">
1705 This warning now includes the name of the offending subroutine.
1709 L<Opening dirhandle %s also as a file. This will be a fatal error in Perl 5.28
1710 |perldiag/Opening dirhandle %s also as a file. This will be a fatal error in Perl 5.28>
1712 This existing warning has had the I<this will be a fatal error> text added
1717 L<Opening filehandle %s also as a directory. This will be a fatal error in Perl 5.28
1718 |perldiag/Opening filehandle %s also as a directory. This will be a fatal error in Perl 5.28>
1720 This existing warning has had the I<this will be a fatal error> text added
1725 panic: ck_split, type=%u
1727 panic: pp_split, pm=%p, s=%p
1729 These panic errors have been removed.
1733 Passing malformed UTF-8 to "%s" is deprecated
1735 This warning has been changed to the fatal
1736 L<Malformed UTF-8 string in "%s"
1737 |perldiag/Malformed UTF-8 string in "%s">
1741 L<Setting C<< $E<sol> >> to a reference to %s as a form of slurp is deprecated, treating as undef. This will be fatal in Perl 5.28
1742 |perldiag/Setting C<< $E<sol> >> to a reference to %s as a form of slurp is deprecated, treating as undef. This will be fatal in Perl 5.28>
1744 This existing warning has had the I<this will be fatal> text added in
1749 L<C<${^ENCODING}> is no longer supported. Its use will be fatal in Perl 5.28|perldiag/"${^ENCODING} is no longer supported. Its use will be fatal in Perl 5.28">
1751 This warning used to be: "Setting C<${^ENCODING}> is deprecated".
1753 The special action of the variable C<${^ENCODING}> was formerly used to
1754 implement the C<encoding> pragma. As of Perl 5.26, rather than being
1755 deprecated, assigning to this variable now has no effect except to issue
1760 L<Too few arguments for subroutine '%s'
1761 |perldiag/Too few arguments for subroutine '%s'>
1763 This warning now includes the name of the offending subroutine.
1767 L<Too many arguments for subroutine '%s'
1768 |perldiag/Too many arguments for subroutine '%s'>
1770 This warning now includes the name of the offending subroutine.
1774 L<Unescaped left brace in regex is deprecated here (and will be fatal in Perl 5.30), passed through in regex; marked by S<< E<lt>-- HERE >> in mE<sol>%sE<sol>
1775 |perldiag/Unescaped left brace in regex is deprecated here (and will be fatal in Perl 5.30), passed through in regex; marked by S<< E<lt>-- HERE >> in mE<sol>%sE<sol>>
1777 This existing warning has had the I<here (and will be fatal...)> text
1778 added in this release.
1782 L<Unknown charname '' is deprecated. Its use will be fatal in Perl 5.28
1783 |perldiag/Unknown charname '' is deprecated. Its use will be fatal in Perl 5.28>
1785 This existing warning has had the I<its use will be fatal> text added in
1790 L<Use of bare E<lt>E<lt> to mean E<lt>E<lt>"" is deprecated. Its use will be fatal in Perl 5.28
1791 |perldiag/Use of bare E<lt>E<lt> to mean E<lt>E<lt>"" is deprecated. Its use will be fatal in Perl 5.28>
1793 This existing warning has had the I<its use will be fatal> text added in
1798 L<Use of code point 0x%s is deprecated; the permissible max is 0x%s. This will be fatal in Perl 5.28
1799 |perldiag/Use of code point 0x%s is deprecated; the permissible max is 0x%s. This will be fatal in Perl 5.28>
1801 This existing warning has had the I<this will be fatal> text added in
1806 L<Use of comma-less variable list is deprecated. Its use will be fatal in Perl 5.28
1807 |perldiag/Use of comma-less variable list is deprecated. Its use will be fatal in Perl 5.28>
1809 This existing warning has had the I<its use will be fatal> text added in
1814 L<Use of inherited C<AUTOLOAD> for non-method %s() is deprecated. This will be fatal in Perl 5.28
1815 |perldiag/Use of inherited C<AUTOLOAD> for non-method %s() is deprecated. This will be fatal in Perl 5.28>
1817 This existing warning has had the I<this will be fatal> text added in
1822 L<Use of strings with code points over 0xFF as arguments to %s operator is deprecated. This will be a fatal error in Perl 5.28
1823 |perldiag/Use of strings with code points over 0xFF as arguments to %s operator is deprecated. This will be a fatal error in Perl 5.28>
1825 This existing warning has had the I<this will be a fatal error> text added in
1830 =head1 Utility Changes
1832 =head2 F<c2ph> and F<pstruct>
1838 These old utilities have long since superceded by L<h2xs>, and are
1839 now gone from the distribution.
1843 =head2 F<Porting/pod_lib.pl>
1849 Removed spurious executable bit.
1853 Account for the possibility of DOS file endings.
1857 =head2 F<Porting/sync-with-cpan>
1867 =head2 F<perf/benchmarks>
1873 Tidy file, rename some symbols.
1877 =head2 F<Porting/checkAUTHORS.pl>
1883 Replace obscure character range with C<\w>.
1887 =head2 F<t/porting/regen.t>
1893 Try to be more helpful when tests fail.
1897 =head2 F<utils/h2xs.PL>
1903 Avoid infinite loop for enums.
1913 Long lines in the message body are now wrapped at 900 characters, to stay
1914 well within the 1000-character limit imposed by SMTP mail transfer agents.
1915 This is particularly likely to be important for the list of arguments to
1916 F<Configure>, which can readily exceed the limit if, for example, it names
1917 several non-default installation paths. This change also adds the first unit
1919 L<[perl #128020]|https://rt.perl.org/Public/Bug/Display.html?id=128020>
1923 =head1 Configuration and Compilation
1929 C<-Ddefault_inc_excludes_dot> has added, and enabled by default.
1933 The C<dtrace> build process has further changes
1934 L<[perl #130108]|https://rt.perl.org/Public/Bug/Display.html?id=130108>:
1940 If the C<-xnolibs> is available, use that so a F<dtrace> perl can be
1941 built within a FreeBSD jail.
1945 On systems that build a F<dtrace> object file (FreeBSD, Solaris, and
1946 SystemTap's dtrace emulation), copy the input objects to a separate
1947 directory and process them there, and use those objects in the link,
1948 since C<dtrace -G> also modifies these objects.
1952 Add F<libelf> to the build on FreeBSD 10.x, since F<dtrace> adds
1953 references to F<libelf> symbols.
1957 Generate a dummy F<dtrace_main.o> if C<dtrace -G> fails to build it. A
1958 default build on Solaris generates probes from the unused inline
1959 functions, while they don't on FreeBSD, which causes C<dtrace -G> to
1966 You can now disable perl's use of the C<PERL_HASH_SEED> and
1967 C<PERL_PERTURB_KEYS> environment variables by configuring perl with
1968 C<-Accflags=NO_PERL_HASH_ENV>.
1972 You can now disable perl's use of the C<PERL_HASH_SEED_DEBUG> environment
1973 variable by configuring perl with
1974 C<-Accflags=-DNO_PERL_HASH_SEED_DEBUG>.
1978 F<Configure> now zeroes out the alignment bytes when calculating the bytes
1979 for 80-bit C<NaN> and C<Inf> to make builds more reproducible.
1980 L<[perl #130133]|https://rt.perl.org/Public/Bug/Display.html?id=130133>
1984 Since v5.18, for testing purposes we have included support for
1985 building perl with a variety of non-standard, and non-recommended
1986 hash functions. Since we do not recommend the use of these functions,
1987 we have removed them and their corresponding build options. Specifically
1988 this includes the following build options:
1992 PERL_HASH_FUNC_SUPERFAST
1993 PERL_HASH_FUNC_MURMUR3
1994 PERL_HASH_FUNC_ONE_AT_A_TIME
1995 PERL_HASH_FUNC_ONE_AT_A_TIME_OLD
1996 PERL_HASH_FUNC_MURMUR_HASH_64A
1997 PERL_HASH_FUNC_MURMUR_HASH_64B
2001 Remove "Warning: perl appears in your path"
2003 This install warning is more or less obsolete, since most platforms already
2004 B<will> have a F</usr/bin/perl> or similar provided by the OS.
2008 Reduce verbosity of C<make install.man>
2010 Previously, two progress messages were emitted for each manpage: one by
2011 installman itself, and one by the function in F<install_lib.pl> that it calls to
2012 actually install the file. Disabling the second of those in each case saves
2013 over 750 lines of unhelpful output.
2017 Cleanup for C<clang -Weverything> support.
2018 L<[perl #129961]|https://rt.perl.org/Public/Bug/Display.html?id=129961>
2022 F<Configure>: signbit scan was assuming too much, stop assuming negative 0.
2026 Various compiler warnings have been silenced.
2030 Several smaller changes have been made to remove impediments to compiling
2035 Builds using C<USE_PAD_RESET> now work again; this configuration had
2040 A probe for C<gai_strerror> was added to F<Configure> that checks if
2041 the C<gai_strerror()> routine is available and can be used to
2042 translate error codes returned by C<getaddrinfo()> into human
2047 F<Configure> now aborts if both C<-Duselongdouble> and C<-Dusequadmath> are
2049 L<[perl #126203]|https://rt.perl.org/Public/Bug/Display.html?id=126203>
2053 Fixed a bug in which F<Configure> could append C<-quadmath> to the
2054 archname even if it was already present.
2055 L<[perl #128538]|https://rt.perl.org/Public/Bug/Display.html?id=128538>
2059 Clang builds with C<-DPERL_GLOBAL_STRUCT> or
2060 C<-DPERL_GLOBAL_STRUCT_PRIVATE> have
2061 been fixed (by disabling Thread Safety Analysis for these configurations).
2065 F<make_ext.pl> no longer updates a module's F<pm_to_blib> file when no
2066 files require updates. This could cause dependencies, F<perlmain.c>
2067 in particular, to be rebuilt unnecessarily.
2068 L<[perl #126710]|https://rt.perl.org/Public/Bug/Display.html?id=126710>
2072 The output of C<perl -V> has been reformatted so that each configuration
2073 and compile-time option is now listed one per line, to improve
2078 F<Configure> now builds C<miniperl> and C<generate_uudmap> if you
2079 invoke it with C<-Dusecrosscompiler> but not C<-Dtargethost=somehost>.
2080 This means you can supply your target platform C<config.sh>, generate
2081 the headers and proceed to build your cross-target perl.
2082 L<[perl #127234]|https://rt.perl.org/Public/Bug/Display.html?id=127234>
2086 Perl built with C<-Accflags=-DPERL_TRACE_OPS> now only dumps the operator
2087 counts when the environment variable C<PERL_TRACE_OPS> is set to a
2088 non-zero integer. This allows C<make test> to pass on such a build.
2092 When building with GCC 6 and link-time optimization (the C<-flto> option to
2093 C<gcc>), F<Configure> was treating all probed symbols as present on the
2094 system, regardless of whether they actually exist. This has been fixed.
2095 L<[perl #128131]|https://rt.perl.org/Public/Bug/Display.html?id=128131>
2099 The F<t/test.pl> library is used for internal testing of Perl itself, and
2100 also copied by several CPAN modules. Some of those modules must work on
2101 older versions of Perl, so F<t/test.pl> must in turn avoid newer Perl
2102 features. Compatibility with Perl 5.8 was inadvertently removed some time
2103 ago; it has now been restored.
2104 L<[perl #128052]|https://rt.perl.org/Public/Bug/Display.html?id=128052>
2108 The build process no longer emits an extra blank line before building each
2109 "simple" extension (those with only F<*.pm> and F<*.pod> files).
2115 Tests were added and changed to reflect the other additions and changes
2116 in this release. Furthermore, these substantive changes were made:
2122 A new test script, F<comp/parser_run.t>, has been added that is like
2123 F<comp/parser.t> but with F<test.pl> included so that C<runperl()> and the
2124 like are available for use.
2128 Tests for locales were erroneously using locales incompatible with Perl.
2132 Some parts of the test suite that try to exhaustively test edge cases in the
2133 regex implementation have been restricted to running for a maximum of five
2134 minutes. On slow systems they could otherwise take several hours, without
2135 significantly improving our understanding of the correctness of the code
2140 A new internal facility allows analysing the time taken by the individual
2141 tests in Perl's own test suite; see F<Porting/harness-timer-report.pl>.
2145 F<t/re/regexp_nonull.t> has been added to test that the regular expression
2146 engine can handle scalars that do not have a null byte just past the end of
2151 A new test script, F<t/op/decl-refs.t>, has been added to test the new feature
2152 L</Declaring a reference to a variable>.
2156 A new test script, F<t/re/keep_tabs.t> has been added to contain tests
2157 where C<\t> characters should not be expanded into spaces.
2161 A new test script, F<t/re/anyof.t>, has been added to test that the ANYOF nodes
2162 generated by bracketed character classes are as expected.
2166 There is now more extensive testing of the Unicode-related API macros
2171 Several of the longer running API test files have been split into
2172 multiple test files so that they can be run in parallel.
2176 F<t/harness> now tries really hard not to run tests which are located
2177 outside of the Perl source tree.
2178 L<[perl #124050]|https://rt.perl.org/Public/Bug/Display.html?id=124050>
2182 Prevent debugger tests (F<lib/perl5db.t>) from failing due to the contents
2183 of C<$ENV{PERLDB_OPTS}>.
2184 L<[perl #130445]|https://rt.perl.org/Public/Bug/Display.html?id=130445>
2188 =head1 Platform Support
2190 =head2 New Platforms
2196 Perl now compiles under NetBSD on VAX machines. However, it's not
2197 possible for that platform to implement floating-point infinities and
2198 NaNs compatible with most modern systems, which implement the IEEE-754
2199 floating point standard. The hexadecimal floating point (C<0x...p[+-]n>
2200 literals, C<printf %a>) is not implemented, either.
2201 The C<make test> passes 98% of tests.
2207 Test fixes and minor updates.
2211 Account for lack of C<inf>, C<nan>, and C<-0.0> support.
2217 =head2 Platform-Specific Notes
2227 Don't treat C<-Dprefix=/usr> as special: instead require an extra option
2228 C<-Ddarwin_distribution> to produce the same results.
2232 OS X El Capitan doesn't implement the C<clock_gettime()> or
2233 C<clock_getres()> APIs; emulate them as necessary.
2237 Deprecated C<syscall(2)> on macOS 10.12.
2243 Several tests have been updated to work (or be skipped) on EBCDIC platforms.
2247 The L<Net::Ping> UDP test is now skipped on HP-UX.
2251 The hints for Hurd have been improved, enabling malloc wrap and reporting the
2252 GNU libc used (previously it was an empty string when reported).
2256 VAX floating point formats are now supported on NetBSD.
2264 The path separator for the C<PERL5LIB> and C<PERLLIB> environment entries is
2265 now a colon (C<":">) when running under a Unix shell. There is no change when
2266 running under DCL (it's still C<"|">).
2270 F<configure.com> now recognizes the VSI-branded C compiler and no longer
2271 recognizes the "DEC"-branded C compiler (as there hasn't been such a thing for
2282 Support for compiling perl on Windows using Microsoft Visual Studio 2015
2283 (containing Visual C++ 14.0) has been added.
2285 This version of VC++ includes a completely rewritten C run-time library, some
2286 of the changes in which mean that work done to resolve a socket
2288 perl #120091 and perl #118059 is not workable in its current state with this
2289 version of VC++. Therefore, we have effectively reverted that bug fix for
2290 VS2015 onwards on the basis that being able to build with VS2015 onwards is
2291 more important than keeping the bug fix. We may revisit this in the future to
2292 attempt to fix the bug again in a way that is compatible with VS2015.
2294 These changes do not affect compilation with GCC or with Visual Studio versions
2295 up to and including VS2013, I<i.e.>, the bug fix is retained (unchanged) for those
2298 Note that you may experience compatibility problems if you mix a perl built
2299 with GCC or VS E<lt>= VS2013 with XS modules built with VS2015, or if you mix a
2300 perl built with VS2015 with XS modules built with GCC or VS E<lt>= VS2013.
2301 Some incompatibility may arise because of the bug fix that has been reverted
2302 for VS2015 builds of perl, but there may well be incompatibility anyway because
2303 of the rewritten CRT in VS2015 (I<e.g.>, see discussion at
2304 L<http://stackoverflow.com/questions/30412951>).
2308 It now automatically detects GCC versus Visual C and sets the VC version
2315 Drop support for Linux F<a.out> executable format. Linux has used ELF for
2320 OpenBSD 6 still does not support returning C<pid>, C<gid>, or C<uid> with
2321 C<SA_SIGINFO>. Make sure to account for it.
2325 F<t/uni/overload.t>: Skip hanging test on FreeBSD.
2329 DragonFly BSD now has support for C<setproctitle()>.
2330 L<[perl #130068]|https://rt.perl.org/Public/Bug/Display.html?id=130068>.
2334 =head1 Internal Changes
2340 A new API function L<C<sv_setpv_bufsize()>|perlapi/sv_setpv_bufsize>
2341 allows simultaneously setting the
2342 length and the allocated size of the buffer in an C<SV>, growing the
2343 buffer if necessary.
2347 A new API macro L<C<SvPVCLEAR()>|perlapi/SvPVCLEAR> sets its C<SV>
2348 argument to an empty string,
2349 like Perl-space C<$x = ''>, but with several optimisations.
2353 Several new macros and functions for dealing with Unicode and
2354 UTF-8-encoded strings have been added to the API, as well as some
2356 functionality of existing functions (see L<perlapi/Unicode Support> for
2363 New versions of the API macros like C<isALPHA_utf8> and C<toLOWER_utf8>
2364 have been added, each with the suffix C<_safe>, like
2365 L<C<isSPACE_utf8_safe>|perlapi/isSPACE>. These take an extra
2366 parameter, giving an upper
2367 limit of how far into the string it is safe to read. Using the old
2368 versions could cause attempts to read beyond the end of the input buffer
2369 if the UTF-8 is not well-formed, and their use now raises a deprecation
2370 warning. Details are at L<perlapi/Character classification>.
2374 Macros like L<C<isALPHA_utf8>|perlapi/isALPHA> and
2375 L<C<toLOWER_utf8>|perlapi/toLOWER_utf8> now die if they detect
2376 that their input UTF-8 is malformed. A deprecation warning had been
2377 issued since Perl 5.18.
2381 Several new macros for analysing the validity of utf8 sequences. These
2384 L<C<UTF8_GOT_ABOVE_31_BIT>|perlapi/UTF8_GOT_ABOVE_31_BIT>
2385 L<C<UTF8_GOT_CONTINUATION>|perlapi/UTF8_GOT_CONTINUATION>
2386 L<C<UTF8_GOT_EMPTY>|perlapi/UTF8_GOT_EMPTY>
2387 L<C<UTF8_GOT_LONG>|perlapi/UTF8_GOT_LONG>
2388 L<C<UTF8_GOT_NONCHAR>|perlapi/UTF8_GOT_NONCHAR>
2389 L<C<UTF8_GOT_NON_CONTINUATION>|perlapi/UTF8_GOT_NON_CONTINUATION>
2390 L<C<UTF8_GOT_OVERFLOW>|perlapi/UTF8_GOT_OVERFLOW>
2391 L<C<UTF8_GOT_SHORT>|perlapi/UTF8_GOT_SHORT>
2392 L<C<UTF8_GOT_SUPER>|perlapi/UTF8_GOT_SUPER>
2393 L<C<UTF8_GOT_SURROGATE>|perlapi/UTF8_GOT_SURROGATE>
2394 L<C<UTF8_IS_INVARIANT>|perlapi/UTF8_IS_INVARIANT>
2395 L<C<UTF8_IS_NONCHAR>|perlapi/UTF8_IS_NONCHAR>
2396 L<C<UTF8_IS_SUPER>|perlapi/UTF8_IS_SUPER>
2397 L<C<UTF8_IS_SURROGATE>|perlapi/UTF8_IS_SURROGATE>
2398 L<C<UVCHR_IS_INVARIANT>|perlapi/UVCHR_IS_INVARIANT>
2399 L<C<isUTF8_CHAR_flags>|perlapi/isUTF8_CHAR_flags>
2400 L<C<isSTRICT_UTF8_CHAR>|perlapi/isSTRICT_UTF8_CHAR>
2401 L<C<isC9_STRICT_UTF8_CHAR>|perlapi/isC9_STRICT_UTF8_CHAR>
2405 Functions that are all extensions of the C<is_utf8_string_I<*>()> functions,
2406 that apply various restrictions to the UTF-8 recognized as valid:
2408 L<C<is_strict_utf8_string>|perlapi/is_strict_utf8_string>,
2409 L<C<is_strict_utf8_string_loc>|perlapi/is_strict_utf8_string_loc>,
2410 L<C<is_strict_utf8_string_loclen>|perlapi/is_strict_utf8_string_loclen>,
2412 L<C<is_c9strict_utf8_string>|perlapi/is_c9strict_utf8_string>,
2413 L<C<is_c9strict_utf8_string_loc>|perlapi/is_c9strict_utf8_string_loc>,
2414 L<C<is_c9strict_utf8_string_loclen>|perlapi/is_c9strict_utf8_string_loclen>,
2416 L<C<is_utf8_string_flags>|perlapi/is_utf8_string_flags>,
2417 L<C<is_utf8_string_loc_flags>|perlapi/is_utf8_string_loc_flags>,
2418 L<C<is_utf8_string_loclen_flags>|perlapi/is_utf8_string_loclen_flags>,
2420 L<C<is_utf8_fixed_width_buf_flags>|perlapi/is_utf8_fixed_width_buf_flags>,
2421 L<C<is_utf8_fixed_width_buf_loc_flags>|perlapi/is_utf8_fixed_width_buf_loc_flags>,
2422 L<C<is_utf8_fixed_width_buf_loclen_flags>|perlapi/is_utf8_fixed_width_buf_loclen_flags>.
2424 L<C<is_utf8_invariant_string>|perlapi/is_utf8_invariant_string>.
2425 L<C<is_utf8_valid_partial_char>|perlapi/is_utf8_valid_partial_char>.
2426 L<C<is_utf8_valid_partial_char_flags>|perlapi/is_utf8_valid_partial_char_flags>.
2430 The functions L<C<utf8n_to_uvchr>|perlapi/utf8n_to_uvchr> and its
2431 derivatives have had several changes of behaviour.
2433 Calling them, while passing a string length of 0 is now asserted against
2434 in DEBUGGING builds, and otherwise, returns the Unicode REPLACEMENT
2435 CHARACTER. If you have nothing to decode, you shouldn't call the decode
2438 They now return the Unicode REPLACEMENT CHARACTER if called with UTF-8
2439 that has the overlong malformation and that malformation is allowed by
2440 the input parameters. This malformation is where the UTF-8 looks valid
2441 syntactically, but there is a shorter sequence that yields the same code
2442 point. This has been forbidden since Unicode version 3.1.
2444 They now accept an input
2445 flag to allow the overflow malformation. This malformation is when the
2446 UTF-8 may be syntactically valid, but the code point it represents is
2447 not capable of being represented in the word length on the platform.
2448 What "allowed" means, in this case, is that the function doesn't return an
2449 error, and it advances the parse pointer to beyond the UTF-8 in
2450 question, but it returns the Unicode REPLACEMENT CHARACTER as the value
2451 of the code point (since the real value is not representable).
2453 They no longer abandon searching for other malformations when the first
2454 one is encountered. A call to one of these functions thus can generate
2455 multiple diagnostics, instead of just one.
2459 L<C<valid_utf8_to_uvchr()>|perlapi/valid_utf8_to_uvchr> has been added
2460 to the API (although it was
2461 present in core earlier). Like C<utf8_to_uvchr_buf()>, but assumes that
2462 the next character is well-formed. Use with caution.
2466 A new function, L<C<utf8n_to_uvchr_error>|perlapi/utf8n_to_uvchr_error>,
2468 use by modules that need to know the details of UTF-8 malformations
2469 beyond pass/fail. Previously, the only ways to know why a sequence was
2470 ill-formed was to capture and parse the generated diagnostics or to do
2475 There is now a safer version of utf8_hop(), called
2476 L<C<utf8_hop_safe()>|perlapi/utf8_hop_safe>.
2477 Unlike utf8_hop(), utf8_hop_safe() won't navigate before the beginning or
2478 after the end of the supplied buffer.
2482 Two new functions, L<C<utf8_hop_forward()>|perlapi/utf8_hop_forward> and
2483 L<C<utf8_hop_back()>|perlapi/utf8_hop_back> are
2484 similar to C<utf8_hop_safe()> but are for when you know which direction
2489 Two new macros which return useful utf8 byte sequences:
2491 L<C<BOM_UTF8>|perlapi/BOM_UTF8>
2493 L<C<REPLACEMENT_CHARACTER_UTF8>|perlapi/REPLACEMENT_CHARACTER_UTF8>
2499 Perl is now built with the C<PERL_OP_PARENT> compiler define enabled by
2500 default. To disable it, use the C<PERL_NO_OP_PARENT> compiler define.
2501 This flag alters how the C<op_sibling> field is used in C<OP> structures,
2502 and has been available optionally since perl 5.22.
2504 See L<perl5220delta/"Internal Changes"> for more details of what this
2509 Three new ops, C<OP_ARGELEM>, C<OP_ARGDEFELEM>, and C<OP_ARGCHECK> have
2510 been added. These are intended principally to implement the individual
2511 elements of a subroutine signature, plus any overall checking required.
2515 The C<OP_PUSHRE> op has been eliminated and the C<OP_SPLIT> op has been
2516 changed from class C<LISTOP> to C<PMOP>.
2518 Formerly the first child of a split would be a C<pushre>, which would have the
2519 C<split>'s regex attached to it. Now the regex is attached directly to the
2520 C<split> op, and the C<pushre> has been eliminated.
2524 The L<C<op_class()>|perlapi/op_class> API function has been added. This
2525 is like the existing
2526 C<OP_CLASS()> macro, but can more accurately determine what struct an op
2527 has been allocated as. For example C<OP_CLASS()> might return
2528 C<OA_BASEOP_OR_UNOP> indicating that ops of this type are usually
2529 allocated as an C<OP> or C<UNOP>; while C<op_class()> will return
2530 C<OPclass_BASEOP> or C<OPclass_UNOP> as appropriate.
2534 All parts of the internals now agree that the C<sassign> op is a C<BINOP>;
2535 previously it was listed as a C<BASEOP> in F<regen/opcodes>, which meant
2536 that several parts of the internals had to be special-cased to accommodate
2537 it. This oddity's original motivation was to handle code like C<$x ||= 1>;
2538 that is now handled in a simpler way.
2542 The output format of the L<C<op_dump()>|perlapi/op_dump> function (as
2543 used by C<perl -Dx>)
2544 has changed: it now displays an "ASCII-art" tree structure, and shows more
2545 low-level details about each op, such as its address and class.
2549 The C<PADOFFSET> type has changed from being unsigned to signed, and
2550 several pad-related variables such as C<PL_padix> have changed from being
2551 of type C<I32> to type C<PADOFFSET>.
2555 The C<DEBUGGING>-mode output for regex compilation and execution has been
2560 Several obscure SV flags have been eliminated, sometimes along with the
2561 macros which manipulate them: C<SVpbm_VALID>, C<SVpbm_TAIL>, C<SvTAIL_on>,
2562 C<SvTAIL_off>, C<SVrepl_EVAL>, C<SvEVALED>.
2566 An OP C<op_private> flag has been eliminated: C<OPpRUNTIME>. This used to
2567 often get set on C<PMOP> ops, but had become meaningless over time.
2571 =head1 Selected Bug Fixes
2577 Perl no longer panics when switching into some locales on machines with
2578 buggy C<strxfrm()> implementations in their F<libc>.
2579 L<[perl #121734]|https://rt.perl.org/Public/Bug/Display.html?id=121734>
2583 C< $-{$name} > would leak an C<AV> on each access if the regular
2584 expression had no named captures. The same applies to access to any
2585 hash tied with L<Tie::Hash::NamedCapture> and C<< all =E<gt> 1 >>.
2586 L<[perl #130822]|https://rt.perl.org/Public/Bug/Display.html?id=130822>
2590 Attempting to use the deprecated variable C<$#> as the object in an
2591 indirect object method call could cause a heap use after free or
2593 L<[perl #129274]|https://rt.perl.org/Public/Bug/Display.html?id=129274>
2597 When checking for an indirect object method call, in some rare cases
2598 the parser could reallocate the line buffer but then continue to use
2599 pointers to the old buffer.
2600 L<[perl #129190]|https://rt.perl.org/Public/Bug/Display.html?id=129190>
2604 Supplying a glob as the format argument to
2605 L<C<formline>|perlfunc/formline> would
2606 cause an assertion failure.
2607 L<[perl #130722]|https://rt.perl.org/Public/Bug/Display.html?id=130722>
2611 Code like C< $value1 =~ qr/.../ ~~ $value2 > would have the match
2612 converted into a C<qr//> operator, leaving extra elements on the stack to
2613 confuse any surrounding expression.
2614 L<[perl #130705]|https://rt.perl.org/Public/Bug/Display.html?id=130705>
2618 Since v5.24 in some obscure cases, a regex which included code blocks
2619 from multiple sources (I<e.g.>, via embedded via C<qr//> objects) could end up
2620 with the wrong current pad and crash or give weird results.
2621 L<[perl #129881]|https://rt.perl.org/Public/Bug/Display.html?id=129881>
2625 Occasionally C<local()>s in a code block within a patterns weren't being
2626 undone when the pattern matching backtracked over the code block.
2627 L<[perl #126697]|https://rt.perl.org/Public/Bug/Display.html?id=126697>
2631 Using C<substr()> to modify a magic variable could access freed memory
2633 L<[perl #129340]|https://rt.perl.org/Public/Bug/Display.html?id=129340>
2637 Under C<use utf8>, the entire source code is now checked for being UTF-8
2638 well formed, not just quoted strings as before.
2639 L<[perl #126310]|https://rt.perl.org/Public/Bug/Display.html?id=126310>.
2643 The range operator C<".."> on strings now handles its arguments correctly when in
2644 the scope of the L<< C<unicode_strings>|feature/"The 'unicode_strings' feature" >>
2645 feature. The previous behaviour was sufficiently unexpected that we believe no
2646 correct program could have made use of it.
2650 The C<split> operator did not ensure enough space was allocated for
2651 its return value in scalar context. It could then write a single
2652 pointer immediately beyond the end of the memory block allocated for
2654 L<[perl #130262]|https://rt.perl.org/Public/Bug/Display.html?id=130262>
2658 Using a large code point with the C<"W"> pack template character with
2659 the current output position aligned at just the right point could
2660 cause a write of a single zero byte immediately beyond the end of an
2662 L<[perl #129149]|https://rt.perl.org/Public/Bug/Display.html?id=129149>
2666 Supplying a format's picture argument as part of the format argument list
2667 where the picture specifies modifying the argument could cause an
2668 access to the new freed compiled form.at.
2669 L<[perl #129125]|https://rt.perl.org/Public/Bug/Display.html?id=129125>
2673 The L<sort()|perlfunc/sort> operator's built-in numeric comparison
2674 function didn't handle large integers that weren't exactly
2675 representable by a double. This now uses the same code used to
2676 implement the C<< E<lt>=E<gt> >> operator.
2677 L<[perl #130335]|https://rt.perl.org/Public/Bug/Display.html?id=130335>
2681 Fix issues with C</(?{ ... E<lt>E<lt>EOF })/> that broke
2682 L<Method::Signatures>.
2683 L<[perl #130398]|https://rt.perl.org/Public/Bug/Display.html?id=130398>
2687 Fixed an assertion failure with C<chop> and C<chomp>, which
2688 could be triggered by C<chop(@x =~ tr/1/1/)>.
2689 L<[perl #130198]|https://rt.perl.org/Public/Bug/Display.html?id=130198>.
2693 Fixed a comment skipping error in patterns under C</x>; it could stop
2694 skipping a byte early, which could be in the middle of a UTF-8
2696 L<[perl #130495]|https://rt.perl.org/Public/Bug/Display.html?id=130495>.
2700 F<perldb> now ignores F</dev/tty> on non-Unix systems.
2701 L<[perl #113960]|https://rt.perl.org/Public/Bug/Display.html?id=113960>;
2705 Fix assertion failure for C<{}-E<gt>$x> when C<$x> isn't defined.
2706 L<[perl #130496]|https://rt.perl.org/Public/Bug/Display.html?id=130496>.
2710 Fix an assertion error which could be triggered when a lookahead string
2711 in patterns exceeded a minimum length.
2712 L<[perl #130522]|https://rt.perl.org/Public/Bug/Display.html?id=130522>.
2716 Only warn once per literal number about a misplaced C<"_">.
2717 L<[perl #70878]|https://rt.perl.org/Public/Bug/Display.html?id=70878>.
2721 The C<tr///> parse code could be looking at uninitialized data after a
2723 L<[perl #129342]|https://rt.perl.org/Public/Bug/Display.html?id=129342>.
2727 In a pattern match, a back-reference (C<\1>) to an unmatched capture could
2728 read back beyond the start of the string being matched.
2729 L<[perl #129377]|https://rt.perl.org/Public/Bug/Display.html?id=129377>.
2733 C<use re 'strict'> is supposed to warn if you use a range (such as
2734 C</(?[ [ X-Y ] ])/>) whose start and end digit aren't from the same group
2735 of 10. It didn't do that for five groups of mathematical digits starting
2740 A sub containing a "forward" declaration with the same name (I<e.g.>,
2741 C<sub c { sub c; }>) could sometimes crash or loop infinitely.
2742 L<[perl #129090]|https://rt.perl.org/Public/Bug/Display.html?id=129090>
2746 A crash in executing a regex with a non-anchored UTF-8 substring against a
2747 target string that also used UTF-8 has been fixed.
2748 L<[perl #129350]|https://rt.perl.org/Public/Bug/Display.html?id=129350>
2752 Previously, a shebang line like C<#!perl -i u> could be erroneously
2753 interpreted as requesting the C<-u> option. This has been fixed.
2754 L<[perl #129336]|https://rt.perl.org/Public/Bug/Display.html?id=129336>
2758 The regex engine was previously producing incorrect results in some rare
2759 situations when backtracking past an alternation that matches only one
2761 showed up as capture buffers (C<$1>, C<$2>, I<etc.>) erroneously containing data
2762 from regex execution paths that weren't actually executed for the final
2764 L<[perl #129897]|https://rt.perl.org/Public/Bug/Display.html?id=129897>
2768 Certain regexes making use of the experimental C<regex_sets> feature could
2769 trigger an assertion failure. This has been fixed.
2770 L<[perl #129322]|https://rt.perl.org/Public/Bug/Display.html?id=129322>
2774 Invalid assignments to a reference constructor (I<e.g.>, C<\eval=time>) could
2775 sometimes crash in addition to giving a syntax error.
2776 L<[perl #125679]|https://rt.perl.org/Public/Bug/Display.html?id=125679>
2780 The parser could sometimes crash if a bareword came after C<evalbytes>.
2781 L<[perl #129196]|https://rt.perl.org/Public/Bug/Display.html?id=129196>
2785 Autoloading via a method call would warn erroneously ("Use of inherited
2786 AUTOLOAD for non-method") if there was a stub present in the package into
2787 which the invocant had been blessed. The warning is no longer emitted in
2789 L<[perl #47047]|https://rt.perl.org/Public/Bug/Display.html?id=47047>
2793 The use of C<splice> on arrays with non-existent elements could cause other
2795 L<[perl #129164]|https://rt.perl.org/Public/Bug/Display.html?id=129164>
2799 A possible buffer overrun when a pattern contains a fixed utf8 substring.
2800 L<[perl #129012]|https://rt.perl.org/Public/Bug/Display.html?id=129012>
2804 Fixed two possible use-after-free bugs in perl's lexer.
2805 L<[perl #129069]|https://rt.perl.org/Public/Bug/Display.html?id=129069>
2809 Fixed a crash with C<s///l> where it thought it was dealing with UTF-8
2811 L<[perl #129038]|https://rt.perl.org/Public/Bug/Display.html?id=129038>
2815 Fixed a place where the regex parser was not setting the syntax error
2816 correctly on a syntactically incorrect pattern.
2817 L<[perl #129122]|https://rt.perl.org/Public/Bug/Display.html?id=129122>
2821 The C<&.> operator (and the C<"&"> operator, when it treats its arguments as
2822 strings) were failing to append a trailing null byte if at least one string
2823 was marked as utf8 internally. Many code paths (system calls, regexp
2824 compilation) still expect there to be a null byte in the string buffer
2825 just past the end of the logical string. An assertion failure was the
2827 L<[perl #129287]|https://rt.perl.org/Public/Bug/Display.html?id=129287>
2831 Avoid a heap-after-use error in the parser when creating an error messge
2832 for a syntactically invalid heredoc.
2833 L<[perl #128988]|https://rt.perl.org/Public/Bug/Display.html?id=128988>
2837 Fix a segfault when run with C<-DC> options on DEBUGGING builds.
2838 L<[perl #129106]|https://rt.perl.org/Public/Bug/Display.html?id=129106>
2842 Fixed the parser error handling in subroutine attributes for an
2843 'C<:attr(foo>' that does not have an ending 'C<")">'.
2847 Fix the perl lexer to correctly handle a backslash as the last char in
2848 quoted-string context. This actually fixed two bugs,
2849 L<[perl #129064]|https://rt.perl.org/Public/Bug/Display.html?id=129064> and
2850 L<[perl #129176]|https://rt.perl.org/Public/Bug/Display.html?id=129176>.
2854 In the API function C<gv_fetchmethod_pvn_flags>, rework separator parsing
2855 to prevent possible string overrun with an invalid C<len> argument.
2856 L<[perl #129267]|https://rt.perl.org/Public/Bug/Display.html?id=129267>
2860 Problems with in-place array sorts: code like C<@a = sort { ... } @a>,
2861 where the source and destination of the sort are the same plain array, are
2862 optimised to do less copying around. Two side-effects of this optimisation
2863 were that the contents of C<@a> as seen by sort routines were
2864 partially sorted; and under some circumstances accessing C<@a> during the
2865 sort could crash the interpreter. Both these issues have been fixed, and
2866 Sort functions see the original value of C<@a>.
2867 L<[perl #128340]|https://rt.perl.org/Public/Bug/Display.html?id=128340>
2871 Non-ASCII string delimiters are now reported correctly in error messages
2872 for unterminated strings.
2873 L<[perl #128701]|https://rt.perl.org/Public/Bug/Display.html?id=128701>
2877 C<pack("p", ...)> used to emit its warning ("Attempt to pack pointer to
2878 temporary value") erroneously in some cases, but has been fixed.
2882 C<@DB::args> is now exempt from "used once" warnings. The warnings only
2883 occurred under B<-w>, because F<warnings.pm> itself uses C<@DB::args>
2888 The use of built-in arrays or hash slices in a double-quoted string no
2889 longer issues a warning ("Possible unintended interpolation...") if the
2890 variable has not been mentioned before. This affected code like
2891 C<qq|@DB::args|> and C<qq|@SIG{'CHLD', 'HUP'}|>. (The special variables
2892 C<@-> and C<@+> were already exempt from the warning.)
2896 C<gethostent> and similar functions now perform a null check internally, to
2897 avoid crashing with the torsocks library. This was a regression from v5.22.
2898 L<[perl #128740]|https://rt.perl.org/Public/Bug/Display.html?id=128740>
2902 C<defined *{'!'}>, C<defined *{'['}>, and C<defined *{'-'}> no longer leak
2903 memory if the typeglob in question has never been accessed before.
2907 Mentioning the same constant twice in a row (which is a syntax error) no
2908 longer fails an assertion under debugging builds. This was a regression
2910 L<[perl #126482]|https://rt.perl.org/Public/Bug/Display.html?id=126482>
2914 Many issues relating to C<printf "%a"> of hexadecimal floating point
2915 were fixed. In addition, the "subnormals" (formerly known as "denormals")
2916 floating point numbers are now supported both with the plain IEEE 754
2917 floating point numbers (64-bit or 128-bit) and the x86 80-bit
2918 "extended precision". Note that subnormal hexadecimal floating
2919 point literals will give a warning about "exponent underflow".
2920 L<[perl #128843]|https://rt.perl.org/Public/Bug/Display.html?id=128843>
2921 L<[perl #128889]|https://rt.perl.org/Public/Bug/Display.html?id=128889>
2922 L<[perl #128890]|https://rt.perl.org/Public/Bug/Display.html?id=128890>
2923 L<[perl #128893]|https://rt.perl.org/Public/Bug/Display.html?id=128893>
2924 L<[perl #128909]|https://rt.perl.org/Public/Bug/Display.html?id=128909>
2925 L<[perl #128919]|https://rt.perl.org/Public/Bug/Display.html?id=128919>
2929 A regression in v5.24 with C<tr/\N{U+...}/foo/> when the code point was between
2930 128 and 255 has been fixed.
2931 L<[perl #128734]|https://rt.perl.org/Public/Bug/Display.html?id=128734>.
2935 Use of a string delimiter whose code point is above 2**31 now works
2936 correctly on platforms that allow this. Previously, certain characters,
2937 due to truncation, would be confused with other delimiter characters
2938 with special meaning (such as C<"?"> in C<m?...?>), resulting
2939 in inconsistent behaviour. Note that this is non-portable,
2940 and is based on Perl's extension to UTF-8, and is probably not
2941 displayable nor enterable by any editor.
2942 L<[perl #128738]|https://rt.perl.org/Public/Bug/Display.html?id=128738>
2946 C<@{x> followed by a newline where C<"x"> represents a control or non-ASCII
2947 character no longer produces a garbled syntax error message or a crash.
2948 L<[perl #128951]|https://rt.perl.org/Public/Bug/Display.html?id=128951>
2952 An assertion failure with C<%: = 0> has been fixed.
2953 L<[perl #128238]|https://rt.perl.org/Public/Bug/Display.html?id=128238>
2957 In Perl 5.18, the parsing of C<"$foo::$bar"> was accidentally changed, such
2958 that it would be treated as C<$foo."::".$bar>. The previous behavior, which
2959 was to parse it as C<$foo:: . $bar>, has been restored.
2960 L<[perl #128478]|https://rt.perl.org/Public/Bug/Display.html?id=128478>
2964 Since Perl 5.20, line numbers have been off by one when perl is invoked with
2965 the B<-x> switch. This has been fixed.
2966 L<[perl #128508]|https://rt.perl.org/Public/Bug/Display.html?id=128508>
2970 Vivifying a subroutine stub in a deleted stash (I<e.g.>,
2971 C<delete $My::{"Foo::"}; \&My::Foo::foo>) no longer crashes. It had begun
2972 crashing in Perl 5.18.
2973 L<[perl #128532]|https://rt.perl.org/Public/Bug/Display.html?id=128532>
2977 Some obscure cases of subroutines and file handles being freed at the same time
2978 could result in crashes, but have been fixed. The crash was introduced in Perl
2980 L<[perl #128597]|https://rt.perl.org/Public/Bug/Display.html?id=128597>
2984 Code that looks for a variable name associated with an uninitialized value
2985 could cause an assertion failure in cases where magic is involved, such as
2986 C<$ISA[0][0]>. This has now been fixed.
2987 L<[perl #128253]|https://rt.perl.org/Public/Bug/Display.html?id=128253>
2991 A crash caused by code generating the warning "Subroutine STASH::NAME
2992 redefined" in cases such as C<sub P::f{} undef *P::; *P::f =sub{};> has been
2993 fixed. In these cases, where the STASH is missing, the warning will now appear
2994 as "Subroutine NAME redefined".
2995 L<[perl #128257]|https://rt.perl.org/Public/Bug/Display.html?id=128257>
2999 Fixed an assertion triggered by some code that handles deprecated behavior in
3000 formats, I<e.g.>, in cases like this:
3006 L<[perl #128255]|https://rt.perl.org/Public/Bug/Display.html?id=128255>
3010 A possible divide by zero in string transformation code on Windows has been
3011 avoided, fixing a crash when collating an empty string.
3012 L<[perl #128618]|https://rt.perl.org/Public/Bug/Display.html?id=128618>
3016 Some regular expression parsing glitches could lead to assertion failures with
3017 regular expressions such as C</(?E<lt>=/> and C</(?E<lt>!/>. This has now been fixed.
3018 L<[perl #128170]|https://rt.perl.org/Public/Bug/Display.html?id=128170>
3022 C< until ($x = 1) { ... } > and C< ... until $x = 1 > now properly
3023 warn when syntax warnings are enabled.
3024 L<[perl #127333]|https://rt.perl.org/Public/Bug/Display.html?id=127333>
3028 socket() now leaves the error code returned by the system in C<$!> on
3030 L<[perl #128316]|https://rt.perl.org/Public/Bug/Display.html?id=128316>
3034 Assignment variants of any bitwise ops under the C<bitwise> feature would
3035 crash if the left-hand side was an array or hash.
3036 L<[perl #128204]|https://rt.perl.org/Public/Bug/Display.html?id=128204>
3040 C<require> followed by a single colon (as in C<foo() ? require : ...> is
3041 now parsed correctly as C<require> with implicit C<$_>, rather than
3043 L<[perl #128307]|https://rt.perl.org/Public/Bug/Display.html?id=128307>
3047 Scalar C<keys %hash> can now be assigned to consistently in all scalar
3048 lvalue contexts. Previously it worked for some contexts but not others.
3052 List assignment to C<vec> or C<substr> with an array or hash for its first
3053 argument used to result in crashes or "Can't coerce" error messages at run
3054 time, unlike scalar assignment, which would give an error at compile time.
3055 List assignment now gives a compile-time error, too.
3056 L<[perl #128260]|https://rt.perl.org/Public/Bug/Display.html?id=128260>
3060 Expressions containing an C<&&> or C<||> operator (or their synonyms C<and>
3061 and C<or>) were being compiled incorrectly in some cases. If the left-hand
3062 side consisted of either a negated bareword constant or a negated C<do {}>
3063 block containing a constant expression, and the right-hand side consisted of
3064 a negated non-foldable expression, one of the negations was effectively
3065 ignored. The same was true of C<if> and C<unless> statement modifiers,
3066 though with the left-hand and right-hand sides swapped. This long-standing
3067 bug has now been fixed.
3068 L<[perl #127952]|https://rt.perl.org/Public/Bug/Display.html?id=127952>
3072 C<reset> with an argument no longer crashes when encountering stash entries
3074 L<[perl #128106]|https://rt.perl.org/Public/Bug/Display.html?id=128106>
3078 Assignment of hashes to, and deletion of, typeglobs named C<*::::::> no
3079 longer causes crashes.
3080 L<[perl #128086]|https://rt.perl.org/Public/Bug/Display.html?id=128086>
3084 Perl wasn't correctly handling true/false values in the LHS of a list
3085 assign; specifically the truth values returned by boolean operators.
3086 This could trigger an assertion failure in something like the following:
3089 ($_, ...) = (...); # here $_ is aliased to a truth value
3092 This was a regression from v5.24.
3093 L<[perl #129991]|https://rt.perl.org/Public/Bug/Display.html?id=129991>
3097 Assertion failure with user-defined Unicode-like properties.
3098 L<[perl #130010]|https://rt.perl.org/Public/Bug/Display.html?id=130010>
3102 Fix error message for unclosed C<\N{> in a regex. An unclosed C<\N{>
3103 could give the wrong error message:
3104 C<"\N{NAME} must be resolved by the lexer">.
3108 List assignment in list context where the LHS contained aggregates and
3109 where there were not enough RHS elements, used to skip scalar lvalues.
3110 Previously, C<(($a,$b,@c,$d) = (1))> in list context returned C<($a)>; now
3111 it returns C<($a,$b,$d)>. C<(($a,$b,$c) = (1))> is unchanged: it still
3112 returns C<($a,$b,$c)>. This can be seen in the following:
3114 sub inc { $_++ for @_ }
3115 inc(($a,$b,@c,$d) = (10))
3117 Formerly, the values of C<($a,$b,$d)> would be left as C<(11,undef,undef)>;
3118 now they are C<(11,1,1)>.
3122 Code like this: C</(?{ s!!! })/> could trigger infinite recursion on the C
3123 stack (not the normal perl stack) when the last successful pattern in
3124 scope is itself. We avoid the segfault by simply forbidding the use of
3125 the empty pattern when it would resolve to the currently executing
3127 L<[perl #129903]|https://rt.perl.org/Public/Bug/Display.html?id=129903>
3131 Avoid reading beyond the end of the line buffer in perl's lexer when
3132 there's a short UTF-8 character at the end.
3133 L<[perl #128997]|https://rt.perl.org/Public/Bug/Display.html?id=128997>
3137 Alternations in regular expressions were sometimes failing to match
3138 a utf8 string against a utf8 alternate.
3139 L<[perl #129950]|https://rt.perl.org/Public/Bug/Display.html?id=129950>
3143 Make C<do "a\0b"> fail silently (and return C<undef> and set C<$!>)
3144 instead of throwing an error.
3145 L<[perl #129928]|https://rt.perl.org/Public/Bug/Display.html?id=129928>
3149 C<chdir> with no argument didn't ensure that there was stack space
3150 available for returning its result.
3151 L<[perl #129130]|https://rt.perl.org/Public/Bug/Display.html?id=129130>
3155 All error messages related to C<do> now refer to C<do>; some formerly
3156 claimed to be from C<require> instead.
3160 Executing C<undef $x> where C<$x> is tied or magical no longer incorrectly
3161 blames the variable for an uninitialized-value warning encountered by the
3166 Code like C<$x = $x . "a"> was incorrectly failing to yield a
3167 L<use of uninitialized value|perldiag/"Use of uninitialized value%s">
3168 warning when C<$x> was a lexical variable with an undefined value. That has
3170 L<[perl #127877]|https://rt.perl.org/Public/Bug/Display.html?id=127877>
3174 C<undef *_; shift> or C<undef *_; pop> inside a subroutine, with no
3175 argument to C<shift> or C<pop>, began crashing in Perl 5.14, but has now
3180 C<< "string$scalar-E<gt>$*" >> now correctly prefers concatenation
3181 overloading to string overloading if C<< $scalar-E<gt>$* >> returns an
3182 overloaded object, bringing it into consistency with C<$$scalar>.
3186 C<< /@0{0*-E<gt>@*/*0 >> and similar contortions used to crash, but no longer
3187 do, but merely produce a syntax error.
3188 L<[perl #128171]|https://rt.perl.org/Public/Bug/Display.html?id=128171>
3192 C<do> or C<require> with an argument which is a reference or typeglob
3193 which, when stringified,
3194 contains a null character, started crashing in Perl 5.20, but has now been
3196 L<[perl #128182]|https://rt.perl.org/Public/Bug/Display.html?id=128182>
3200 Improve the error message for a missing C<tie()> package/method. This
3201 brings the error messages in line with the ones used for normal method
3206 Parsing bad POSIX charclasses no longer leaks memory.
3207 L<[perl #128313]|https://rt.perl.org/Public/Bug/Display.html?id=128313>
3211 =head1 Known Problems
3217 G++ 6 handles subnormal (denormal) floating point values differently
3218 than gcc 6 or g++ 5 resulting in "flush-to-zero". The end result is
3219 that if you specify very small values using the hexadecimal floating
3220 point format, like C<0x1.fffffffffffffp-1022>, they become zeros.
3221 L<[perl #131388]|https://rt.perl.org/Ticket/Display.html?id=131388>
3225 =head1 Errata From Previous Releases
3231 Fixed issues with recursive regexes. The behavior was fixed in Perl 5.24.
3232 L<[perl #126182]|https://rt.perl.org/Public/Bug/Display.html?id=126182>
3238 Jon Portnoy (AVENJ), a prolific Perl author and admired Gentoo community
3239 member, has passed away on August 10, 2016. He will be remembered and
3240 missed by all those who he came in contact with, and enriched with his
3241 intellect, wit, and spirit.
3243 It is with great sadness that we also note Kip Hampton's passing. Probably
3244 best known as the author of the Perl & XML column on XML.com, he was a
3245 core contributor to AxKit, an XML server platform that became an Apache
3246 Foundation project. He was a frequent speaker in the early days at
3247 OSCON, and most recently at YAPC::NA in Madison. He was frequently on
3248 irc.perl.org as ubu, generally in the #axkit-dahut community, the
3249 group responsible for YAPC::NA Asheville in 2011.
3251 Kip and his constant contributions to the community will be greatly
3254 =head1 Acknowledgements
3256 Perl 5.26.0 represents approximately 13 months of development since Perl 5.24.0
3257 and contains approximately 360,000 lines of changes across 2,600 files from 86
3260 Excluding auto-generated files, documentation and release tools, there were
3261 approximately 230,000 lines of changes to 1,800 .pm, .t, .c and .h files.
3263 Perl continues to flourish into its third decade thanks to a vibrant community
3264 of users and developers. The following people are known to have contributed the
3265 improvements that became Perl 5.26.0:
3267 Aaron Crane, Abigail, Ævar Arnfjörð Bjarmason, Alex Vandiver, Andreas
3268 König, Andreas Voegele, Andrew Fresh, Andy Lester, Aristotle Pagaltzis, Chad
3269 Granum, Chase Whitener, Chris 'BinGOs' Williams, Chris Lamb, Christian Hansen,
3270 Christian Millour, Colin Newell, Craig A. Berry, Dagfinn Ilmari Mannsåker, Dan
3271 Collins, Daniel Dragan, Dave Cross, Dave Rolsky, David Golden, David H.
3272 Gutteridge, David Mitchell, Dominic Hargreaves, Doug Bell, E. Choroba, Ed Avis,
3273 Father Chrysostomos, François Perrad, Hauke D, H.Merijn Brand, Hugo van der
3274 Sanden, Ivan Pozdeev, James E Keenan, James Raspass, Jarkko Hietaniemi, Jerry
3275 D. Hedden, Jim Cromie, J. Nick Koston, John Lightsey, Karen Etheridge, Karl
3276 Williamson, Leon Timmermans, Lukas Mai, Matthew Horsfall, Maxwell Carey, Misty
3277 De Meo, Neil Bowers, Nicholas Clark, Nicolas R., Niko Tyni, Pali, Paul
3278 Marquess, Peter Avalos, Petr Písař, Pino Toscano, Rafael Garcia-Suarez, Reini
3279 Urban, Renee Baecker, Ricardo Signes, Richard Levitte, Rick Delaney, Salvador
3280 Fandiño, Samuel Thibault, Sawyer X, Sébastien Aperghis-Tramoni, Sergey
3281 Aleynikov, Shlomi Fish, Smylers, Stefan Seifert, Steffen Müller, Stevan
3282 Little, Steve Hay, Steven Humphrey, Sullivan Beck, Theo Buehler, Thomas Sibley,
3283 Todd Rinaldo, Tomasz Konojacki, Tony Cook, Unicode Consortium, Yaroslav Kuzmin,
3286 The list above is almost certainly incomplete as it is automatically generated
3287 from version control history. In particular, it does not include the names of
3288 the (very much appreciated) contributors who reported issues to the Perl bug
3291 Many of the changes included in this version originated in the CPAN modules
3292 included in Perl's core. We're grateful to the entire CPAN community for
3293 helping Perl to flourish.
3295 For a more complete list of all of Perl's historical contributors, please see
3296 the F<AUTHORS> file in the Perl source distribution.
3298 =head1 Reporting Bugs
3300 If you find what you think is a bug, you might check the perl bug database at
3301 L<https://rt.perl.org/>. There may also be information at
3302 L<http://www.perl.org/>, the Perl Home Page.
3304 If you believe you have an unreported bug, please run the L<perlbug> program
3305 included with your release. Be sure to trim your bug down to a tiny but
3306 sufficient test case. Your bug report, along with the output of C<perl -V>,
3307 will be sent off to C<perlbug@perl.org> to be analysed by the Perl porting team.
3309 If the bug you are reporting has security implications which make it
3310 inappropriate to send to a publicly archived mailing list, then see
3311 L<perlsec/SECURITY VULNERABILITY CONTACT INFORMATION>
3312 for details of how to report the issue.
3316 If you wish to thank the Perl 5 Porters for the work we had done in Perl 5,
3317 you can do so by running the C<perlthanks> program:
3321 This will send an email to the Perl 5 Porters list with your show of thanks.
3325 The F<Changes> file for an explanation of how to view exhaustive details on
3328 The F<INSTALL> file for how to build Perl.
3330 The F<README> file for general stuff.
3332 The F<Artistic> and F<Copying> files for copyright information.