1PERL5260DELTA(1) Perl Programmers Reference Guide PERL5260DELTA(1)
2
6 perl5260delta - what is new for perl v5.26.0
7
9 This document describes the differences between the 5.24.0 release and
10 the 5.26.0 release.
11
13 This release includes three updates with widespread effects:
14 · "." no longer in @INC
16 For security reasons, the current directory (".") is no longer
18 included by default at the end of the module search path (@INC).
19 This may have widespread implications for the building, testing and
20 installing of modules, and for the execution of scripts. See the
21 section "Removal of the current directory (".") from @INC" for the
22 full details.
23 · "do" may now warn
25 "do" now gives a deprecation warning when it fails to load a file
27 which it would have loaded had "." been in @INC.
28 · In regular expression patterns, a literal left brace "{" should be
30 escaped
31 See "Unescaped literal "{" characters in regular expression
33 patterns are no longer permissible".
34
36 Lexical subroutines are no longer experimental
37 Using the "lexical_subs" feature introduced in v5.18 no longer emits a
38 warning. Existing code that disables the "experimental::lexical_subs"
39 warning category that the feature previously used will continue to
40 work. The "lexical_subs" feature has no effect; all Perl code can use
41 lexical subroutines, regardless of what feature declarations are in
42 scope.
43 Indented Here-documents
45 This adds a new modifier "~" to here-docs that tells the parser that it
46 should look for "/^\s*$DELIM\n/" as the closing delimiter.
47 These syntaxes are all supported:
49 <<~EOF;
51 <<~\EOF;
52 <<~'EOF';
53 <<~"EOF";
54 <<~`EOF`;
55 <<~ 'EOF';
56 <<~ "EOF";
57 <<~ `EOF`;
58 The "~" modifier will strip, from each line in the here-doc, the same
60 whitespace that appears before the delimiter.
61 Newlines will be copied as-is, and lines that don't include the proper
63 beginning whitespace will cause perl to croak.
64 For example:
66 if (1) {
68 print <<~EOF;
69 Hello there
70 EOF
71 }
72 prints "Hello there\n" with no leading whitespace.
74 New regular expression modifier "/xx"
76 Specifying two "x" characters to modify a regular expression pattern
77 does everything that a single one does, but additionally TAB and SPACE
78 characters within a bracketed character class are generally ignored and
79 can be added to improve readability, like "/[ ^ A-Z d-f p-x ]/xx".
80 Details are at "/x and /xx" in perlre.
81 "@{^CAPTURE}", "%{^CAPTURE}", and "%{^CAPTURE_ALL}"
83 "@{^CAPTURE}" exposes the capture buffers of the last match as an
84 array. So $1 is "${^CAPTURE}[0]". This is a more efficient equivalent
85 to code like "substr($matched_string,$-[0],$+[0]-$-[0])", and you don't
86 have to keep track of the $matched_string either. This variable has no
87 single character equivalent. Note that, like the other regex magic
88 variables, the contents of this variable is dynamic; if you wish to
89 store it beyond the lifetime of the match you must copy it to another
90 array.
91 "%{^CAPTURE}" is equivalent to "%+" (i.e., named captures). Other than
93 being more self-documenting there is no difference between the two
94 forms.
95 "%{^CAPTURE_ALL}" is equivalent to "%-" (i.e., all named captures).
97 Other than being more self-documenting there is no difference between
98 the two forms.
99 Declaring a reference to a variable
101 As an experimental feature, Perl now allows the referencing operator to
102 come after "my()", "state()", "our()", or "local()". This syntax must
103 be enabled with "use feature 'declared_refs'". It is experimental, and
104 will warn by default unless "no warnings 'experimental::refaliasing'"
105 is in effect. It is intended mainly for use in assignments to
106 references. For example:
107 use experimental 'refaliasing', 'declared_refs';
109 my \$a = \$b;
110 See "Assigning to References" in perlref for more details.
112 Unicode 9.0 is now supported
114 A list of changes is at
115 <http://www.unicode.org/versions/Unicode9.0.0/>. Modules that are
116 shipped with core Perl but not maintained by p5p do not necessarily
117 support Unicode 9.0. Unicode::Normalize does work on 9.0.
118 Use of "\p{script}" uses the improved Script_Extensions property
120 Unicode 6.0 introduced an improved form of the Script ("sc") property,
121 and called it Script_Extensions ("scx"). Perl now uses this improved
122 version when a property is specified as just "\p{script}". This should
123 make programs more accurate when determining if a character is used in
124 a given script, but there is a slight chance of breakage for programs
125 that very specifically needed the old behavior. The meaning of
126 compound forms, like "\p{sc=script}" are unchanged. See "Scripts" in
127 perlunicode.
128 Perl can now do default collation in UTF-8 locales on platforms that
130 support it
131 Some platforms natively do a reasonable job of collating and sorting in
132 UTF-8 locales. Perl now works with those. For portability and full
133 control, Unicode::Collate is still recommended, but now you may not
134 need to do anything special to get good-enough results, depending on
135 your application. See "Category "LC_COLLATE": Collation: Text
136 Comparisons and Sorting" in perllocale.
137 Better locale collation of strings containing embedded "NUL" characters
139 In locales that have multi-level character weights, "NUL"s are now
140 ignored at the higher priority ones. There are still some gotchas in
141 some strings, though. See "Collation of strings containing embedded
142 "NUL" characters" in perllocale.
143 "CORE" subroutines for hash and array functions callable via reference
145 The hash and array functions in the "CORE" namespace ("keys", "each",
146 "values", "push", "pop", "shift", "unshift" and "splice") can now be
147 called with ampersand syntax ("&CORE::keys(\%hash") and via reference
148 ("my $k = \&CORE::keys; $k->(\%hash)"). Previously they could only be
149 used when inlined.
150 New Hash Function For 64-bit Builds
152 We have switched to a hybrid hash function to better balance
153 performance for short and long keys.
154 For short keys, 16 bytes and under, we use an optimised variant of One
156 At A Time Hard, and for longer keys we use Siphash 1-3. For very long
157 keys this is a big improvement in performance. For shorter keys there
158 is a modest improvement.
159
161 Removal of the current directory (".") from @INC
162 The perl binary includes a default set of paths in @INC. Historically
163 it has also included the current directory (".") as the final entry,
164 unless run with taint mode enabled ("perl -T"). While convenient, this
165 has security implications: for example, where a script attempts to load
166 an optional module when its current directory is untrusted (such as
167 /tmp), it could load and execute code from under that directory.
168 Starting with v5.26, "." is always removed by default, not just under
170 tainting. This has major implications for installing modules and
171 executing scripts.
172 The following new features have been added to help ameliorate these
174 issues.
175 · Configure -Udefault_inc_excludes_dot
177 There is a new Configure option, "default_inc_excludes_dot"
179 (enabled by default) which builds a perl executable without ".";
180 unsetting this option using "-U" reverts perl to the old behaviour.
181 This may fix your path issues but will reintroduce all the security
182 concerns, so don't build a perl executable like this unless you're
183 really confident that such issues are not a concern in your
184 environment.
185 · "PERL_USE_UNSAFE_INC"
187 There is a new environment variable recognised by the perl
189 interpreter. If this variable has the value 1 when the perl
190 interpreter starts up, then "." will be automatically appended to
191 @INC (except under tainting).
192 This allows you restore the old perl interpreter behaviour on a
194 case-by-case basis. But note that this is intended to be a
195 temporary crutch, and this feature will likely be removed in some
196 future perl version. It is currently set by the "cpan" utility and
197 "Test::Harness" to ease installation of CPAN modules which have not
198 been updated to handle the lack of dot. Once again, don't use this
199 unless you are sure that this will not reintroduce any security
200 concerns.
201 · A new deprecation warning issued by "do".
203 While it is well-known that "use" and "require" use @INC to search
205 for the file to load, many people don't realise that "do "file""
206 also searches @INC if the file is a relative path. With the
207 removal of ".", a simple "do "file.pl"" will fail to read in and
208 execute "file.pl" from the current directory. Since this is
209 commonly expected behaviour, a new deprecation warning is now
210 issued whenever "do" fails to load a file which it otherwise would
211 have found if a dot had been in @INC.
212 Here are some things script and module authors may need to do to make
214 their software work in the new regime.
215 · Script authors
217 If the issue is within your own code (rather than within included
219 modules), then you have two main options. Firstly, if you are
220 confident that your script will only be run within a trusted
221 directory (under which you expect to find trusted files and
222 modules), then add "." back into the path; e.g.:
223 BEGIN {
225 my $dir = "/some/trusted/directory";
226 chdir $dir or die "Can't chdir to $dir: $!\n";
227 # safe now
228 push @INC, '.';
229 }
230 use "Foo::Bar"; # may load /some/trusted/directory/Foo/Bar.pm
232 do "config.pl"; # may load /some/trusted/directory/config.pl
233 On the other hand, if your script is intended to be run from within
235 untrusted directories (such as /tmp), then your script suddenly
236 failing to load files may be indicative of a security issue. You
237 most likely want to replace any relative paths with full paths; for
238 example,
239 do "foo_config.pl"
241 might become
243 do "$ENV{HOME}/foo_config.pl"
245 If you are absolutely certain that you want your script to load and
247 execute a file from the current directory, then use a "./" prefix;
248 for example:
249 do "./foo_config.pl"
251 · Installing and using CPAN modules
253 If you install a CPAN module using an automatic tool like "cpan",
255 then this tool will itself set the "PERL_USE_UNSAFE_INC"
256 environment variable while building and testing the module, which
257 may be sufficient to install a distribution which hasn't been
258 updated to be dot-aware. If you want to install such a module
259 manually, then you'll need to replace the traditional invocation:
260 perl Makefile.PL && make && make test && make install
262 with something like
264 (export PERL_USE_UNSAFE_INC=1; \
266 perl Makefile.PL && make && make test && make install)
267 Note that this only helps build and install an unfixed module.
269 It's possible for the tests to pass (since they were run under
270 "PERL_USE_UNSAFE_INC=1"), but for the module itself to fail to
271 perform correctly in production. In this case, you may have to
272 temporarily modify your script until a fixed version of the module
273 is released. For example:
274 use Foo::Bar;
276 {
277 local @INC = (@INC, '.');
278 # assuming read_config() needs '.' in @INC
279 $config = Foo::Bar->read_config();
280 }
281 This is only rarely expected to be necessary. Again, if doing
283 this, assess the resultant risks first.
284 · Module Authors
286 If you maintain a CPAN distribution, it may need updating to run in
288 a dotless environment. Although "cpan" and other such tools will
289 currently set the "PERL_USE_UNSAFE_INC" during module build, this
290 is a temporary workaround for the set of modules which rely on "."
291 being in @INC for installation and testing, and this may mask
292 deeper issues. It could result in a module which passes tests and
293 installs, but which fails at run time.
294 During build, test, and install, it will normally be the case that
296 any perl processes will be executing directly within the root
297 directory of the untarred distribution, or a known subdirectory of
298 that, such as t/. It may well be that Makefile.PL or t/foo.t will
299 attempt to include local modules and configuration files using
300 their direct relative filenames, which will now fail.
301 However, as described above, automatic tools like cpan will (for
303 now) set the "PERL_USE_UNSAFE_INC" environment variable, which
304 introduces dot during a build.
305 This makes it likely that your existing build and test code will
307 work, but this may mask issues with your code which only manifest
308 when used after install. It is prudent to try and run your build
309 process with that variable explicitly disabled:
310 (export PERL_USE_UNSAFE_INC=0; \
312 perl Makefile.PL && make && make test && make install)
313 This is more likely to show up any potential problems with your
315 module's build process, or even with the module itself. Fixing
316 such issues will ensure both that your module can again be
317 installed manually, and that it will still build once the
318 "PERL_USE_UNSAFE_INC" crutch goes away.
319 When fixing issues in tests due to the removal of dot from @INC,
321 reinsertion of dot into @INC should be performed with caution, for
322 this too may suppress real errors in your runtime code. You are
323 encouraged wherever possible to apply the aforementioned approaches
324 with explicit absolute/relative paths, or to relocate your needed
325 files into a subdirectory and insert that subdirectory into @INC
326 instead.
327 If your runtime code has problems under the dotless @INC, then the
329 comments above on how to fix for script authors will mostly apply
330 here too. Bear in mind though that it is considered bad form for a
331 module to globally add a dot to @INC, since it introduces both a
332 security risk and hides issues of accidentally requiring dot in
333 @INC, as explained above.
334 Escaped colons and relative paths in PATH
336 On Unix systems, Perl treats any relative paths in the "PATH"
337 environment variable as tainted when starting a new process.
338 Previously, it was allowing a backslash to escape a colon (unlike the
339 OS), consequently allowing relative paths to be considered safe if the
340 PATH was set to something like "/\:.". The check has been fixed to
341 treat "." as tainted in that example.
342 New "-Di" switch is now required for PerlIO debugging output
344 This is used for debugging of code within PerlIO to avoid recursive
345 calls. Previously this output would be sent to the file specified by
346 the "PERLIO_DEBUG" environment variable if perl wasn't running setuid
347 and the "-T" or "-t" switches hadn't been parsed yet.
348 If perl performed output at a point where it hadn't yet parsed its
350 switches this could result in perl creating or overwriting the file
351 named by "PERLIO_DEBUG" even when the "-T" switch had been supplied.
352 Perl now requires the "-Di" switch to be present before it will produce
354 PerlIO debugging output. By default this is written to "stderr", but
355 can optionally be redirected to a file by setting the "PERLIO_DEBUG"
356 environment variable.
357 If perl is running setuid or the "-T" switch was supplied,
359 "PERLIO_DEBUG" is ignored and the debugging output is sent to "stderr"
360 as for any other "-D" switch.
361
363 Unescaped literal "{" characters in regular expression patterns are no
364 longer permissible
365 You have to now say something like "\{" or "[{]" to specify to match a
366 LEFT CURLY BRACKET; otherwise, it is a fatal pattern compilation error.
367 This change will allow future extensions to the language.
368 These have been deprecated since v5.16, with a deprecation message
370 raised for some uses starting in v5.22. Unfortunately, the code added
371 to raise the message was buggy and failed to warn in some cases where
372 it should have. Therefore, enforcement of this ban for these cases is
373 deferred until Perl 5.30, but the code has been fixed to raise a
374 default-on deprecation message for them in the meantime.
375 Some uses of literal "{" occur in contexts where we do not foresee the
377 meaning ever being anything but the literal, such as the very first
378 character in the pattern, or after a "|" meaning alternation. Thus
379 qr/{fee|{fie/
381 matches either of the strings "{fee" or "{fie". To avoid forcing
383 unnecessary code changes, these uses do not need to be escaped, and no
384 warning is raised about them, and there are no current plans to change
385 this.
386 But it is always correct to escape "{", and the simple rule to remember
388 is to always do so.
389 See Unescaped left brace in regex is illegal here.
391 "scalar(%hash)" return signature changed
393 The value returned for "scalar(%hash)" will no longer show information
394 about the buckets allocated in the hash. It will simply return the
395 count of used keys. It is thus equivalent to "0+keys(%hash)".
396 A form of backward compatibility is provided via
398 "Hash::Util::bucket_ratio()" which provides the same behavior as
399 "scalar(%hash)" provided in Perl 5.24 and earlier.
400 "keys" returned from an lvalue subroutine
402 "keys" returned from an lvalue subroutine can no longer be assigned to
403 in list context.
404 sub foo : lvalue { keys(%INC) }
406 (foo) = 3; # death
407 sub bar : lvalue { keys(@_) }
408 (bar) = 3; # also an error
409 This makes the lvalue sub case consistent with "(keys %hash) = ..." and
411 "(keys @_) = ...", which are also errors. [perl #128187]
412 <https://rt.perl.org/Public/Bug/Display.html?id=128187>
413 The "${^ENCODING}" facility has been removed
415 The special behaviour associated with assigning a value to this
416 variable has been removed. As a consequence, the encoding pragma's
417 default mode is no longer supported. If you still need to write your
418 source code in encodings other than UTF-8, use a source filter such as
419 Filter::Encoding on CPAN or encoding's "Filter" option.
420 "POSIX::tmpnam()" has been removed
422 The fundamentally unsafe "tmpnam()" interface was deprecated in Perl
423 5.22 and has now been removed. In its place, you can use, for example,
424 the File::Temp interfaces.
425 require ::Foo::Bar is now illegal.
427 Formerly, "require ::Foo::Bar" would try to read /Foo/Bar.pm. Now any
428 bareword require which starts with a double colon dies instead.
429 Literal control character variable names are no longer permissible
431 A variable name may no longer contain a literal control character under
432 any circumstances. These previously were allowed in single-character
433 names on ASCII platforms, but have been deprecated there since Perl
434 5.20. This affects things like "$\cT", where \cT is a literal control
435 (such as a "NAK" or "NEGATIVE ACKNOWLEDGE" character) in the source
436 code.
437 "NBSP" is no longer permissible in "\N{...}"
439 The name of a character may no longer contain non-breaking spaces. It
440 has been deprecated to do so since Perl 5.22.
441
443 String delimiters that aren't stand-alone graphemes are now deprecated
444 For Perl to eventually allow string delimiters to be Unicode grapheme
445 clusters (which look like a single character, but may be a sequence of
446 several ones), we have to stop allowing a single character delimiter
447 that isn't a grapheme by itself. These are unlikely to exist in actual
448 code, as they would typically display as attached to the character in
449 front of them.
450 "\cX" that maps to a printable is no longer deprecated
452 This means we have no plans to remove this feature. It still raises a
453 warning, but only if syntax warnings are enabled. The feature was
454 originally intended to be a way to express non-printable characters
455 that don't have a mnemonic ("\t" and "\n" are mnemonics for two non-
456 printable characters, but most non-printables don't have a mnemonic.)
457 But the feature can be used to specify a few printable characters,
458 though those are more clearly expressed as the printable itself. See
459 <http://www.nntp.perl.org/group/perl.perl5.porters/2017/02/msg242944.html>.
460
462 · A hash in boolean context is now sometimes faster, e.g.
463 if (!%h) { ... }
465 This was already special-cased, but some cases were missed (such as
467 "grep %$_, @AoH"), and even the ones which weren't have been
468 improved.
469 · New Faster Hash Function on 64 bit builds
471 We use a different hash function for short and long keys. This
473 should improve performance and security, especially for long keys.
474 · readline is faster
476 Reading from a file line-by-line with "readline()" or "<>" should
478 now typically be faster due to a better implementation of the code
479 that searches for the next newline character.
480 · Assigning one reference to another, e.g. "$ref1 = $ref2" has been
482 optimized in some cases.
483 · Remove some exceptions to creating Copy-on-Write strings. The
485 string buffer growth algorithm has been slightly altered so that
486 you're less likely to encounter a string which can't be COWed.
487 · Better optimise array and hash assignment: where an array or hash
489 appears in the LHS of a list assignment, such as "(..., @a) =
490 (...);", it's likely to be considerably faster, especially if it
491 involves emptying the array/hash. For example, this code runs about
492 a third faster compared to Perl 5.24.0:
493 my @a;
495 for my $i (1..10_000_000) {
496 @a = (1,2,3);
497 @a = ();
498 }
499 · Converting a single-digit string to a number is now substantially
501 faster.
502 · The "split" builtin is now slightly faster in many cases: in
504 particular for the two specially-handled forms
505 my @a = split ...;
507 local @a = split ...;
508 · The rather slow implementation for the experimental subroutine
510 signatures feature has been made much faster; it is now comparable
511 in speed with the traditional "my ($a, $b, @c) = @_".
512 · Bareword constant strings are now permitted to take part in
514 constant folding. They were originally exempted from constant
515 folding in August 1999, during the development of Perl 5.6, to
516 ensure that "use strict "subs"" would still apply to bareword
517 constants. That has now been accomplished a different way, so
518 barewords, like other constants, now gain the performance benefits
519 of constant folding.
520 This also means that void-context warnings on constant expressions
522 of barewords now report the folded constant operand, rather than
523 the operation; this matches the behaviour for non-bareword
524 constants.
525
527 Updated Modules and Pragmata
528 · IO::Compress has been upgraded from version 2.069 to 2.074.
529 · Archive::Tar has been upgraded from version 2.04 to 2.24.
531 · arybase has been upgraded from version 0.11 to 0.12.
533 · attributes has been upgraded from version 0.27 to 0.29.
535 The deprecation message for the ":unique" and ":locked" attributes
537 now mention that they will disappear in Perl 5.28.
538 · B has been upgraded from version 1.62 to 1.68.
540 · B::Concise has been upgraded from version 0.996 to 0.999.
542 Its output is now more descriptive for "op_private" flags.
544 · B::Debug has been upgraded from version 1.23 to 1.24.
546 · B::Deparse has been upgraded from version 1.37 to 1.40.
548 · B::Xref has been upgraded from version 1.05 to 1.06.
550 It now uses 3-arg "open()" instead of 2-arg "open()". [perl
552 #130122] <https://rt.perl.org/Public/Bug/Display.html?id=130122>
553 · base has been upgraded from version 2.23 to 2.25.
555 · bignum has been upgraded from version 0.42 to 0.47.
557 · Carp has been upgraded from version 1.40 to 1.42.
559 · charnames has been upgraded from version 1.43 to 1.44.
561 · Compress::Raw::Bzip2 has been upgraded from version 2.069 to 2.074.
563 · Compress::Raw::Zlib has been upgraded from version 2.069 to 2.074.
565 · Config::Perl::V has been upgraded from version 0.25 to 0.28.
567 · CPAN has been upgraded from version 2.11 to 2.18.
569 · CPAN::Meta has been upgraded from version 2.150005 to 2.150010.
571 · Data::Dumper has been upgraded from version 2.160 to 2.167.
573 The XS implementation now supports Deparse.
575 · DB_File has been upgraded from version 1.835 to 1.840.
577 · Devel::Peek has been upgraded from version 1.23 to 1.26.
579 · Devel::PPPort has been upgraded from version 3.32 to 3.35.
581 · Devel::SelfStubber has been upgraded from version 1.05 to 1.06.
583 It now uses 3-arg "open()" instead of 2-arg "open()". [perl
585 #130122] <https://rt.perl.org/Public/Bug/Display.html?id=130122>
586 · diagnostics has been upgraded from version 1.34 to 1.36.
588 It now uses 3-arg "open()" instead of 2-arg "open()". [perl
590 #130122] <https://rt.perl.org/Public/Bug/Display.html?id=130122>
591 · Digest has been upgraded from version 1.17 to 1.17_01.
593 · Digest::MD5 has been upgraded from version 2.54 to 2.55.
595 · Digest::SHA has been upgraded from version 5.95 to 5.96.
597 · DynaLoader has been upgraded from version 1.38 to 1.42.
599 · Encode has been upgraded from version 2.80 to 2.88.
601 · encoding has been upgraded from version 2.17 to 2.19.
603 This module's default mode is no longer supported. It now dies
605 when imported, unless the "Filter" option is being used.
606 · encoding::warnings has been upgraded from version 0.12 to 0.13.
608 This module is no longer supported. It emits a warning to that
610 effect and then does nothing.
611 · Errno has been upgraded from version 1.25 to 1.28.
613 It now documents that using "%!" automatically loads Errno for you.
615 It now uses 3-arg "open()" instead of 2-arg "open()". [perl
617 #130122] <https://rt.perl.org/Public/Bug/Display.html?id=130122>
618 · ExtUtils::Embed has been upgraded from version 1.33 to 1.34.
620 It now uses 3-arg "open()" instead of 2-arg "open()". [perl
622 #130122] <https://rt.perl.org/Public/Bug/Display.html?id=130122>
623 · ExtUtils::MakeMaker has been upgraded from version 7.10_01 to 7.24.
625 · ExtUtils::Miniperl has been upgraded from version 1.05 to 1.06.
627 · ExtUtils::ParseXS has been upgraded from version 3.31 to 3.34.
629 · ExtUtils::Typemaps has been upgraded from version 3.31 to 3.34.
631 · feature has been upgraded from version 1.42 to 1.47.
633 · File::Copy has been upgraded from version 2.31 to 2.32.
635 · File::Fetch has been upgraded from version 0.48 to 0.52.
637 · File::Glob has been upgraded from version 1.26 to 1.28.
639 It now Issues a deprecation message for "File::Glob::glob()".
641 · File::Spec has been upgraded from version 3.63 to 3.67.
643 · FileHandle has been upgraded from version 2.02 to 2.03.
645 · Filter::Simple has been upgraded from version 0.92 to 0.93.
647 It no longer treats "no MyFilter" immediately following "use
649 MyFilter" as end-of-file. [perl #107726]
650 <https://rt.perl.org/Public/Bug/Display.html?id=107726>
651 · Getopt::Long has been upgraded from version 2.48 to 2.49.
653 · Getopt::Std has been upgraded from version 1.11 to 1.12.
655 · Hash::Util has been upgraded from version 0.19 to 0.22.
657 · HTTP::Tiny has been upgraded from version 0.056 to 0.070.
659 Internal 599-series errors now include the redirect history.
661 · I18N::LangTags has been upgraded from version 0.40 to 0.42.
663 It now uses 3-arg "open()" instead of 2-arg "open()". [perl
665 #130122] <https://rt.perl.org/Public/Bug/Display.html?id=130122>
666 · IO has been upgraded from version 1.36 to 1.38.
668 · IO::Socket::IP has been upgraded from version 0.37 to 0.38.
670 · IPC::Cmd has been upgraded from version 0.92 to 0.96.
672 · IPC::SysV has been upgraded from version 2.06_01 to 2.07.
674 · JSON::PP has been upgraded from version 2.27300 to 2.27400_02.
676 · lib has been upgraded from version 0.63 to 0.64.
678 It now uses 3-arg "open()" instead of 2-arg "open()". [perl
680 #130122] <https://rt.perl.org/Public/Bug/Display.html?id=130122>
681 · List::Util has been upgraded from version 1.42_02 to 1.46_02.
683 · Locale::Codes has been upgraded from version 3.37 to 3.42.
685 · Locale::Maketext has been upgraded from version 1.26 to 1.28.
687 · Locale::Maketext::Simple has been upgraded from version 0.21 to
689 0.21_01.
690 · Math::BigInt has been upgraded from version 1.999715 to 1.999806.
692 · Math::BigInt::FastCalc has been upgraded from version 0.40 to
694 0.5005.
695 · Math::BigRat has been upgraded from version 0.260802 to 0.2611.
697 · Math::Complex has been upgraded from version 1.59 to 1.5901.
699 · Memoize has been upgraded from version 1.03 to 1.03_01.
701 · Module::CoreList has been upgraded from version 5.20170420 to
703 5.20170530.
704 · Module::Load::Conditional has been upgraded from version 0.64 to
706 0.68.
707 · Module::Metadata has been upgraded from version 1.000031 to
709 1.000033.
710 · mro has been upgraded from version 1.18 to 1.20.
712 · Net::Ping has been upgraded from version 2.43 to 2.55.
714 IPv6 addresses and "AF_INET6" sockets are now supported, along with
716 several other enhancements.
717 · NEXT has been upgraded from version 0.65 to 0.67.
719 · Opcode has been upgraded from version 1.34 to 1.39.
721 · open has been upgraded from version 1.10 to 1.11.
723 · OS2::Process has been upgraded from version 1.11 to 1.12.
725 It now uses 3-arg "open()" instead of 2-arg "open()". [perl
727 #130122] <https://rt.perl.org/Public/Bug/Display.html?id=130122>
728 · overload has been upgraded from version 1.26 to 1.28.
730 Its compilation speed has been improved slightly.
732 · parent has been upgraded from version 0.234 to 0.236.
734 · perl5db.pl has been upgraded from version 1.50 to 1.51.
736 It now ignores /dev/tty on non-Unix systems. [perl #113960]
738 <https://rt.perl.org/Public/Bug/Display.html?id=113960>
739 · Perl::OSType has been upgraded from version 1.009 to 1.010.
741 · perlfaq has been upgraded from version 5.021010 to 5.021011.
743 · PerlIO has been upgraded from version 1.09 to 1.10.
745 · PerlIO::encoding has been upgraded from version 0.24 to 0.25.
747 · PerlIO::scalar has been upgraded from version 0.24 to 0.26.
749 · Pod::Checker has been upgraded from version 1.60 to 1.73.
751 · Pod::Functions has been upgraded from version 1.10 to 1.11.
753 · Pod::Html has been upgraded from version 1.22 to 1.2202.
755 · Pod::Perldoc has been upgraded from version 3.25_02 to 3.28.
757 · Pod::Simple has been upgraded from version 3.32 to 3.35.
759 · Pod::Usage has been upgraded from version 1.68 to 1.69.
761 · POSIX has been upgraded from version 1.65 to 1.76.
763 This remedies several defects in making its symbols exportable.
765 [perl #127821]
766 <https://rt.perl.org/Public/Bug/Display.html?id=127821>
767 The "POSIX::tmpnam()" interface has been removed, see
769 "POSIX::tmpnam() has been removed".
770 The following deprecated functions have been removed:
772 POSIX::isalnum
774 POSIX::isalpha
775 POSIX::iscntrl
776 POSIX::isdigit
777 POSIX::isgraph
778 POSIX::islower
779 POSIX::isprint
780 POSIX::ispunct
781 POSIX::isspace
782 POSIX::isupper
783 POSIX::isxdigit
784 POSIX::tolower
785 POSIX::toupper
786 Trying to import POSIX subs that have no real implementations (like
788 "POSIX::atend()") now fails at import time, instead of waiting
789 until runtime.
790 · re has been upgraded from version 0.32 to 0.34
792 This adds support for the new "/xx" regular expression pattern
794 modifier, and a change to the "use re 'strict'" experimental
795 feature. When "re 'strict'" is enabled, a warning now will be
796 generated for all unescaped uses of the two characters "}" and "]"
797 in regular expression patterns (outside bracketed character
798 classes) that are taken literally. This brings them more in line
799 with the ")" character which is always a metacharacter unless
800 escaped. Being a metacharacter only sometimes, depending on an
801 action at a distance, can lead to silently having the pattern mean
802 something quite different than was intended, which the
803 "re 'strict'" mode is intended to minimize.
804 · Safe has been upgraded from version 2.39 to 2.40.
806 · Scalar::Util has been upgraded from version 1.42_02 to 1.46_02.
808 · Storable has been upgraded from version 2.56 to 2.62.
810 Fixes [perl #130098]
812 <https://rt.perl.org/Public/Bug/Display.html?id=130098>.
813 · Symbol has been upgraded from version 1.07 to 1.08.
815 · Sys::Syslog has been upgraded from version 0.33 to 0.35.
817 · Term::ANSIColor has been upgraded from version 4.04 to 4.06.
819 · Term::ReadLine has been upgraded from version 1.15 to 1.16.
821 It now uses 3-arg "open()" instead of 2-arg "open()". [perl
823 #130122] <https://rt.perl.org/Public/Bug/Display.html?id=130122>
824 · Test has been upgraded from version 1.28 to 1.30.
826 It now uses 3-arg "open()" instead of 2-arg "open()". [perl
828 #130122] <https://rt.perl.org/Public/Bug/Display.html?id=130122>
829 · Test::Harness has been upgraded from version 3.36 to 3.38.
831 · Test::Simple has been upgraded from version 1.001014 to 1.302073.
833 · Thread::Queue has been upgraded from version 3.09 to 3.12.
835 · Thread::Semaphore has been upgraded from 2.12 to 2.13.
837 Added the "down_timed" method.
839 · threads has been upgraded from version 2.07 to 2.15.
841 · threads::shared has been upgraded from version 1.51 to 1.56.
843 · Tie::Hash::NamedCapture has been upgraded from version 0.09 to
845 0.10.
846 · Time::HiRes has been upgraded from version 1.9733 to 1.9741.
848 It now builds on systems with C++11 compilers (such as G++ 6 and
850 Clang++ 3.9).
851 Now uses "clockid_t".
853 · Time::Local has been upgraded from version 1.2300 to 1.25.
855 · Unicode::Collate has been upgraded from version 1.14 to 1.19.
857 · Unicode::UCD has been upgraded from version 0.64 to 0.68.
859 It now uses 3-arg "open()" instead of 2-arg "open()". [perl
861 #130122] <https://rt.perl.org/Public/Bug/Display.html?id=130122>
862 · version has been upgraded from version 0.9916 to 0.9917.
864 · VMS::DCLsym has been upgraded from version 1.06 to 1.08.
866 It now uses 3-arg "open()" instead of 2-arg "open()". [perl
868 #130122] <https://rt.perl.org/Public/Bug/Display.html?id=130122>
869 · warnings has been upgraded from version 1.36 to 1.37.
871 · XS::Typemap has been upgraded from version 0.14 to 0.15.
873 · XSLoader has been upgraded from version 0.21 to 0.27.
875 Fixed a security hole in which binary files could be loaded from a
877 path outside of @INC.
878 It now uses 3-arg "open()" instead of 2-arg "open()". [perl
880 #130122] <https://rt.perl.org/Public/Bug/Display.html?id=130122>
881
883 New Documentation
884 perldeprecation
885 This file documents all upcoming deprecations, and some of the
887 deprecations which already have been removed. The purpose of this
888 documentation is two-fold: document what will disappear, and by which
889 version, and serve as a guide for people dealing with code which has
890 features that no longer work after an upgrade of their perl.
891 Changes to Existing Documentation
893 We have attempted to update the documentation to reflect the changes
894 listed in this document. If you find any we have missed, send email to
895 perlbug@perl.org <mailto:perlbug@perl.org>.
896 Additionally, all references to Usenet have been removed, and the
898 following selected changes have been made:
899 perlfunc
901 · Removed obsolete text about "defined()" on aggregates that should
903 have been deleted earlier, when the feature was removed.
904 · Corrected documentation of "eval()", and "evalbytes()".
906 · Clarified documentation of "seek()", "tell()" and "sysseek()"
908 emphasizing that positions are in bytes and not characters. [perl
909 #128607] <https://rt.perl.org/Public/Bug/Display.html?id=128607>
910 · Clarified documentation of "sort()" concerning the variables $a and
912 $b.
913 · In "split()" noted that certain pattern modifiers are legal, and
915 added a caution about its use in Perls before v5.11.
916 · Removed obsolete documentation of "study()", noting that it is now
918 a no-op.
919 · Noted that "vec()" doesn't work well when the string contains
921 characters whose code points are above 255.
922 perlguts
924 · Added advice on formatted printing of operands of "Size_t" and
926 "SSize_t"
927 perlhack
929 · Clarify what editor tab stop rules to use, and note that we are
931 migrating away from using tabs, replacing them with sequences of
932 SPACE characters.
933 perlhacktips
935 · Give another reason to use "cBOOL" to cast an expression to
937 boolean.
938 · Note that the macros "TRUE" and "FALSE" are available to express
940 boolean values.
941 perlinterp
943 · perlinterp has been expanded to give a more detailed example of how
945 to hunt around in the parser for how a given operator is handled.
946 perllocale
948 · Some locales aren't compatible with Perl. Note that these can
950 cause core dumps.
951 perlmod
953 · Various clarifications have been added.
955 perlmodlib
957 · Updated the site mirror list.
959 perlobj
961 · Added a section on calling methods using their fully qualified
963 names.
964 · Do not discourage manual @ISA.
966 perlootut
968 · Mention "Moo" more.
970 perlop
972 · Note that white space must be used for quoting operators if the
974 delimiter is a word character (i.e., matches "\w").
975 · Clarify that in regular expression patterns delimited by single
977 quotes, no variable interpolation is done.
978 perlre
980 · The first part was extensively rewritten to incorporate various
982 basic points, that in earlier versions were mentioned in sort of an
983 appendix on Version 8 regular expressions.
984 · Note that it is common to have the "/x" modifier and forget that
986 this means that "#" has to be escaped.
987 perlretut
989 · Add introductory material.
991 · Note that a metacharacter occurring in a context where it can't
993 mean that, silently loses its meta-ness and matches literally.
994 "use re 'strict'" can catch some of these.
995 perlunicode
997 · Corrected the text about Unicode BYTE ORDER MARK handling.
999 · Updated the text to correspond with changes in Unicode UTS#18,
1001 concerning regular expressions, and Perl compatibility with what it
1002 says.
1003 perlvar
1005 · Document @ISA. It was documented in other places, but not in
1007 perlvar.
1008
1010 New Diagnostics
1011 New Errors
1012 · A signature parameter must start with '$', '@' or '%'
1014 · Bareword in require contains "%s"
1016 · Bareword in require maps to empty filename
1018 · Bareword in require maps to disallowed filename "%s"
1020 · Bareword in require must not start with a double-colon: "%s"
1022 · %s: command not found
1024 (A) You've accidentally run your script through bash or another
1026 shell instead of Perl. Check the "#!" line, or manually feed your
1027 script into Perl yourself. The "#!" line at the top of your file
1028 could look like:
1029 #!/usr/bin/perl
1031 · %s: command not found: %s
1033 (A) You've accidentally run your script through zsh or another
1035 shell instead of Perl. Check the "#!" line, or manually feed your
1036 script into Perl yourself. The "#!" line at the top of your file
1037 could look like:
1038 #!/usr/bin/perl
1040 · The experimental declared_refs feature is not enabled
1042 (F) To declare references to variables, as in "my \%x", you must
1044 first enable the feature:
1045 no warnings "experimental::declared_refs";
1047 use feature "declared_refs";
1048 See "Declaring a reference to a variable".
1050 · Illegal character following sigil in a subroutine signature
1052 · Indentation on line %d of here-doc doesn't match delimiter
1054 · Infinite recursion via empty pattern.
1056 Using the empty pattern (which re-executes the last successfully-
1058 matched pattern) inside a code block in another regex, as in "/(?{
1059 s!!new! })/", has always previously yielded a segfault. It now
1060 produces this error.
1061 · Malformed UTF-8 string in "%s"
1063 · Multiple slurpy parameters not allowed
1065 · '#' not allowed immediately following a sigil in a subroutine
1067 signature
1068 · panic: unknown OA_*: %x
1070 · Unescaped left brace in regex is illegal here
1072 Unescaped left braces are now illegal in some contexts in regular
1074 expression patterns. In other contexts, they are still just
1075 deprecated; they will be illegal in Perl 5.30.
1076 · Version control conflict marker
1078 (F) The parser found a line starting with "<<<<<<<", ">>>>>>>", or
1080 "=======". These may be left by a version control system to mark
1081 conflicts after a failed merge operation.
1082 New Warnings
1084 · Can't determine class of operator %s, assuming "BASEOP"
1086 · Declaring references is experimental
1088 (S experimental::declared_refs) This warning is emitted if you use
1090 a reference constructor on the right-hand side of "my()",
1091 "state()", "our()", or "local()". Simply suppress the warning if
1092 you want to use the feature, but know that in doing so you are
1093 taking the risk of using an experimental feature which may change
1094 or be removed in a future Perl version:
1095 no warnings "experimental::declared_refs";
1097 use feature "declared_refs";
1098 $fooref = my \$foo;
1099 See "Declaring a reference to a variable".
1101 · do "%s" failed, '.' is no longer in @INC
1103 Since "." is now removed from @INC by default, "do" will now
1105 trigger a warning recommending to fix the "do" statement.
1106 · "File::Glob::glob()" will disappear in perl 5.30. Use
1108 "File::Glob::bsd_glob()" instead.
1109 · Unescaped literal '%c' in regex; marked by <-- HERE in m/%s/
1111 · Use of unassigned code point or non-standalone grapheme for a
1113 delimiter will be a fatal error starting in Perl 5.30
1114 See "Deprecations"
1116 Changes to Existing Diagnostics
1118 · When a "require" fails, we now do not provide @INC when the
1119 "require" is for a file instead of a module.
1120 · When @INC is not scanned for a "require" call, we no longer display
1122 @INC to avoid confusion.
1123 · Attribute "locked" is deprecated, and will disappear in Perl 5.28
1125 This existing warning has had the and will disappear text added in
1127 this release.
1128 · Attribute "unique" is deprecated, and will disappear in Perl 5.28
1130 This existing warning has had the and will disappear text added in
1132 this release.
1133 · Calling POSIX::%s() is deprecated
1135 This warning has been removed, as the deprecated functions have
1137 been removed from POSIX.
1138 · Constants from lexical variables potentially modified elsewhere are
1140 deprecated. This will not be allowed in Perl 5.32
1141 This existing warning has had the this will not be allowed text
1143 added in this release.
1144 · Deprecated use of "my()" in false conditional. This will be a fatal
1146 error in Perl 5.30
1147 This existing warning has had the this will be a fatal error text
1149 added in this release.
1150 · "dump()" better written as "CORE::dump()". "dump()" will no longer
1152 be available in Perl 5.30
1153 This existing warning has had the no longer be available text added
1155 in this release.
1156 · Experimental %s on scalar is now forbidden
1158 This message is now followed by more helpful text. [perl #127976]
1160 <https://rt.perl.org/Public/Bug/Display.html?id=127976>
1161 · Experimental "%s" subs not enabled
1163 This warning was been removed, as lexical subs are no longer
1165 experimental.
1166 · Having more than one /%c regexp modifier is deprecated
1168 This deprecation warning has been removed, since "/xx" now has a
1170 new meaning.
1171 · %s() is deprecated on ":utf8" handles. This will be a fatal error
1173 in Perl 5.30 .
1174 where "%s" is one of "sysread", "recv", "syswrite", or "send".
1176 This existing warning has had the this will be a fatal error text
1178 added in this release.
1179 This warning is now enabled by default, as all "deprecated"
1181 category warnings should be.
1182 · $* is no longer supported. Its use will be fatal in Perl 5.30
1184 This existing warning has had the its use will be fatal text added
1186 in this release.
1187 · $# is no longer supported. Its use will be fatal in Perl 5.30
1189 This existing warning has had the its use will be fatal text added
1191 in this release.
1192 · Malformed UTF-8 character%s
1194 Details as to the exact problem have been added at the end of this
1196 message
1197 · Missing or undefined argument to %s
1199 This warning used to warn about "require", even if it was actually
1201 "do" which being executed. It now gets the operation name right.
1202 · NO-BREAK SPACE in a charnames alias definition is deprecated
1204 This warning has been removed as the behavior is now an error.
1206 · Odd name/value argument for subroutine '%s'
1208 This warning now includes the name of the offending subroutine.
1210 · Opening dirhandle %s also as a file. This will be a fatal error in
1212 Perl 5.28
1213 This existing warning has had the this will be a fatal error text
1215 added in this release.
1216 · Opening filehandle %s also as a directory. This will be a fatal
1218 error in Perl 5.28
1219 This existing warning has had the this will be a fatal error text
1221 added in this release.
1222 · panic: ck_split, type=%u
1224 panic: pp_split, pm=%p, s=%p
1226 These panic errors have been removed.
1228 · Passing malformed UTF-8 to "%s" is deprecated
1230 This warning has been changed to the fatal Malformed UTF-8 string
1232 in "%s"
1233 · Setting $/ to a reference to %s as a form of slurp is deprecated,
1235 treating as undef. This will be fatal in Perl 5.28
1236 This existing warning has had the this will be fatal text added in
1238 this release.
1239 · "${^ENCODING}" is no longer supported. Its use will be fatal in
1241 Perl 5.28
1242 This warning used to be: "Setting "${^ENCODING}" is deprecated".
1244 The special action of the variable "${^ENCODING}" was formerly used
1246 to implement the "encoding" pragma. As of Perl 5.26, rather than
1247 being deprecated, assigning to this variable now has no effect
1248 except to issue the warning.
1249 · Too few arguments for subroutine '%s'
1251 This warning now includes the name of the offending subroutine.
1253 · Too many arguments for subroutine '%s'
1255 This warning now includes the name of the offending subroutine.
1257 · Unescaped left brace in regex is deprecated here (and will be fatal
1259 in Perl 5.30), passed through in regex; marked by <-- HERE in m/%s/
1260 This existing warning has had the here (and will be fatal...) text
1262 added in this release.
1263 · Unknown charname '' is deprecated. Its use will be fatal in Perl
1265 5.28
1266 This existing warning has had the its use will be fatal text added
1268 in this release.
1269 · Use of bare << to mean <<"" is deprecated. Its use will be fatal in
1271 Perl 5.28
1272 This existing warning has had the its use will be fatal text added
1274 in this release.
1275 · Use of code point 0x%s is deprecated; the permissible max is 0x%s.
1277 This will be fatal in Perl 5.28
1278 This existing warning has had the this will be fatal text added in
1280 this release.
1281 · Use of comma-less variable list is deprecated. Its use will be
1283 fatal in Perl 5.28
1284 This existing warning has had the its use will be fatal text added
1286 in this release.
1287 · Use of inherited "AUTOLOAD" for non-method %s() is deprecated. This
1289 will be fatal in Perl 5.28
1290 This existing warning has had the this will be fatal text added in
1292 this release.
1293 · Use of strings with code points over 0xFF as arguments to %s
1295 operator is deprecated. This will be a fatal error in Perl 5.28
1296 This existing warning has had the this will be a fatal error text
1298 added in this release.
1299
1301 c2ph and pstruct
1302 · These old utilities have long since superceded by h2xs, and are now
1303 gone from the distribution.
1304 Porting/pod_lib.pl
1306 · Removed spurious executable bit.
1307 · Account for the possibility of DOS file endings.
1309 Porting/sync-with-cpan
1311 · Many improvements.
1312 perf/benchmarks
1314 · Tidy file, rename some symbols.
1315 Porting/checkAUTHORS.pl
1317 · Replace obscure character range with "\w".
1318 t/porting/regen.t
1320 · Try to be more helpful when tests fail.
1321 utils/h2xs.PL
1323 · Avoid infinite loop for enums.
1324 perlbug
1326 · Long lines in the message body are now wrapped at 900 characters,
1327 to stay well within the 1000-character limit imposed by SMTP mail
1328 transfer agents. This is particularly likely to be important for
1329 the list of arguments to Configure, which can readily exceed the
1330 limit if, for example, it names several non-default installation
1331 paths. This change also adds the first unit tests for perlbug.
1332 [perl #128020]
1333 <https://rt.perl.org/Public/Bug/Display.html?id=128020>
1334
1336 · "-Ddefault_inc_excludes_dot" has added, and enabled by default.
1337 · The "dtrace" build process has further changes [perl #130108]
1339 <https://rt.perl.org/Public/Bug/Display.html?id=130108>:
1340 · If the "-xnolibs" is available, use that so a dtrace perl can
1342 be built within a FreeBSD jail.
1343 · On systems that build a dtrace object file (FreeBSD, Solaris,
1345 and SystemTap's dtrace emulation), copy the input objects to a
1346 separate directory and process them there, and use those
1347 objects in the link, since "dtrace -G" also modifies these
1348 objects.
1349 · Add libelf to the build on FreeBSD 10.x, since dtrace adds
1351 references to libelf symbols.
1352 · Generate a dummy dtrace_main.o if "dtrace -G" fails to build
1354 it. A default build on Solaris generates probes from the
1355 unused inline functions, while they don't on FreeBSD, which
1356 causes "dtrace -G" to fail.
1357 · You can now disable perl's use of the "PERL_HASH_SEED" and
1359 "PERL_PERTURB_KEYS" environment variables by configuring perl with
1360 "-Accflags=NO_PERL_HASH_ENV".
1361 · You can now disable perl's use of the "PERL_HASH_SEED_DEBUG"
1363 environment variable by configuring perl with
1364 "-Accflags=-DNO_PERL_HASH_SEED_DEBUG".
1365 · Configure now zeroes out the alignment bytes when calculating the
1367 bytes for 80-bit "NaN" and "Inf" to make builds more reproducible.
1368 [perl #130133]
1369 <https://rt.perl.org/Public/Bug/Display.html?id=130133>
1370 · Since v5.18, for testing purposes we have included support for
1372 building perl with a variety of non-standard, and non-recommended
1373 hash functions. Since we do not recommend the use of these
1374 functions, we have removed them and their corresponding build
1375 options. Specifically this includes the following build options:
1376 PERL_HASH_FUNC_SDBM
1378 PERL_HASH_FUNC_DJB2
1379 PERL_HASH_FUNC_SUPERFAST
1380 PERL_HASH_FUNC_MURMUR3
1381 PERL_HASH_FUNC_ONE_AT_A_TIME
1382 PERL_HASH_FUNC_ONE_AT_A_TIME_OLD
1383 PERL_HASH_FUNC_MURMUR_HASH_64A
1384 PERL_HASH_FUNC_MURMUR_HASH_64B
1385 · Remove "Warning: perl appears in your path"
1387 This install warning is more or less obsolete, since most platforms
1389 already will have a /usr/bin/perl or similar provided by the OS.
1390 · Reduce verbosity of "make install.man"
1392 Previously, two progress messages were emitted for each manpage:
1394 one by installman itself, and one by the function in install_lib.pl
1395 that it calls to actually install the file. Disabling the second
1396 of those in each case saves over 750 lines of unhelpful output.
1397 · Cleanup for "clang -Weverything" support. [perl #129961]
1399 <https://rt.perl.org/Public/Bug/Display.html?id=129961>
1400 · Configure: signbit scan was assuming too much, stop assuming
1402 negative 0.
1403 · Various compiler warnings have been silenced.
1405 · Several smaller changes have been made to remove impediments to
1407 compiling under C++11.
1408 · Builds using "USE_PAD_RESET" now work again; this configuration had
1410 bit-rotted.
1411 · A probe for "gai_strerror" was added to Configure that checks if
1413 the "gai_strerror()" routine is available and can be used to
1414 translate error codes returned by "getaddrinfo()" into human
1415 readable strings.
1416 · Configure now aborts if both "-Duselongdouble" and "-Dusequadmath"
1418 are requested. [perl #126203]
1419 <https://rt.perl.org/Public/Bug/Display.html?id=126203>
1420 · Fixed a bug in which Configure could append "-quadmath" to the
1422 archname even if it was already present. [perl #128538]
1423 <https://rt.perl.org/Public/Bug/Display.html?id=128538>
1424 · Clang builds with "-DPERL_GLOBAL_STRUCT" or
1426 "-DPERL_GLOBAL_STRUCT_PRIVATE" have been fixed (by disabling Thread
1427 Safety Analysis for these configurations).
1428 · make_ext.pl no longer updates a module's pm_to_blib file when no
1430 files require updates. This could cause dependencies, perlmain.c
1431 in particular, to be rebuilt unnecessarily. [perl #126710]
1432 <https://rt.perl.org/Public/Bug/Display.html?id=126710>
1433 · The output of "perl -V" has been reformatted so that each
1435 configuration and compile-time option is now listed one per line,
1436 to improve readability.
1437 · Configure now builds "miniperl" and "generate_uudmap" if you invoke
1439 it with "-Dusecrosscompiler" but not "-Dtargethost=somehost". This
1440 means you can supply your target platform "config.sh", generate the
1441 headers and proceed to build your cross-target perl. [perl
1442 #127234] <https://rt.perl.org/Public/Bug/Display.html?id=127234>
1443 · Perl built with "-Accflags=-DPERL_TRACE_OPS" now only dumps the
1445 operator counts when the environment variable "PERL_TRACE_OPS" is
1446 set to a non-zero integer. This allows "make test" to pass on such
1447 a build.
1448 · When building with GCC 6 and link-time optimization (the "-flto"
1450 option to "gcc"), Configure was treating all probed symbols as
1451 present on the system, regardless of whether they actually exist.
1452 This has been fixed. [perl #128131]
1453 <https://rt.perl.org/Public/Bug/Display.html?id=128131>
1454 · The t/test.pl library is used for internal testing of Perl itself,
1456 and also copied by several CPAN modules. Some of those modules
1457 must work on older versions of Perl, so t/test.pl must in turn
1458 avoid newer Perl features. Compatibility with Perl 5.8 was
1459 inadvertently removed some time ago; it has now been restored.
1460 [perl #128052]
1461 <https://rt.perl.org/Public/Bug/Display.html?id=128052>
1462 · The build process no longer emits an extra blank line before
1464 building each "simple" extension (those with only *.pm and *.pod
1465 files).
1466
1468 Tests were added and changed to reflect the other additions and changes
1469 in this release. Furthermore, these substantive changes were made:
1470 · A new test script, comp/parser_run.t, has been added that is like
1472 comp/parser.t but with test.pl included so that "runperl()" and the
1473 like are available for use.
1474 · Tests for locales were erroneously using locales incompatible with
1476 Perl.
1477 · Some parts of the test suite that try to exhaustively test edge
1479 cases in the regex implementation have been restricted to running
1480 for a maximum of five minutes. On slow systems they could
1481 otherwise take several hours, without significantly improving our
1482 understanding of the correctness of the code under test.
1483 · A new internal facility allows analysing the time taken by the
1485 individual tests in Perl's own test suite; see
1486 Porting/harness-timer-report.pl.
1487 · t/re/regexp_nonull.t has been added to test that the regular
1489 expression engine can handle scalars that do not have a null byte
1490 just past the end of the string.
1491 · A new test script, t/op/decl-refs.t, has been added to test the new
1493 feature "Declaring a reference to a variable".
1494 · A new test script, t/re/keep_tabs.t has been added to contain tests
1496 where "\t" characters should not be expanded into spaces.
1497 · A new test script, t/re/anyof.t, has been added to test that the
1499 ANYOF nodes generated by bracketed character classes are as
1500 expected.
1501 · There is now more extensive testing of the Unicode-related API
1503 macros and functions.
1504 · Several of the longer running API test files have been split into
1506 multiple test files so that they can be run in parallel.
1507 · t/harness now tries really hard not to run tests which are located
1509 outside of the Perl source tree. [perl #124050]
1510 <https://rt.perl.org/Public/Bug/Display.html?id=124050>
1511 · Prevent debugger tests (lib/perl5db.t) from failing due to the
1513 contents of $ENV{PERLDB_OPTS}. [perl #130445]
1514 <https://rt.perl.org/Public/Bug/Display.html?id=130445>
1515
1517 New Platforms
1518 NetBSD/VAX
1519 Perl now compiles under NetBSD on VAX machines. However, it's not
1520 possible for that platform to implement floating-point infinities
1521 and NaNs compatible with most modern systems, which implement the
1522 IEEE-754 floating point standard. The hexadecimal floating point
1523 ("0x...p[+-]n" literals, "printf %a") is not implemented, either.
1524 The "make test" passes 98% of tests.
1525 · Test fixes and minor updates.
1527 · Account for lack of "inf", "nan", and "-0.0" support.
1529 Platform-Specific Notes
1531 Darwin
1532 · Don't treat "-Dprefix=/usr" as special: instead require an
1533 extra option "-Ddarwin_distribution" to produce the same
1534 results.
1535 · OS X El Capitan doesn't implement the "clock_gettime()" or
1537 "clock_getres()" APIs; emulate them as necessary.
1538 · Deprecated syscall(2) on macOS 10.12.
1540 EBCDIC
1542 Several tests have been updated to work (or be skipped) on EBCDIC
1543 platforms.
1544 HP-UX
1546 The Net::Ping UDP test is now skipped on HP-UX.
1547 Hurd
1549 The hints for Hurd have been improved, enabling malloc wrap and
1550 reporting the GNU libc used (previously it was an empty string when
1551 reported).
1552 VAX VAX floating point formats are now supported on NetBSD.
1554 VMS
1556 · The path separator for the "PERL5LIB" and "PERLLIB" environment
1557 entries is now a colon (":") when running under a Unix shell.
1558 There is no change when running under DCL (it's still "|").
1559 · configure.com now recognizes the VSI-branded C compiler and no
1561 longer recognizes the "DEC"-branded C compiler (as there hasn't
1562 been such a thing for 15 or more years).
1563 Windows
1565 · Support for compiling perl on Windows using Microsoft Visual
1566 Studio 2015 (containing Visual C++ 14.0) has been added.
1567 This version of VC++ includes a completely rewritten C run-time
1569 library, some of the changes in which mean that work done to
1570 resolve a socket "close()" bug in perl #120091 and perl #118059
1571 is not workable in its current state with this version of VC++.
1572 Therefore, we have effectively reverted that bug fix for VS2015
1573 onwards on the basis that being able to build with VS2015
1574 onwards is more important than keeping the bug fix. We may
1575 revisit this in the future to attempt to fix the bug again in a
1576 way that is compatible with VS2015.
1577 These changes do not affect compilation with GCC or with Visual
1579 Studio versions up to and including VS2013, i.e., the bug fix
1580 is retained (unchanged) for those compilers.
1581 Note that you may experience compatibility problems if you mix
1583 a perl built with GCC or VS <= VS2013 with XS modules built
1584 with VS2015, or if you mix a perl built with VS2015 with XS
1585 modules built with GCC or VS <= VS2013. Some incompatibility
1586 may arise because of the bug fix that has been reverted for
1587 VS2015 builds of perl, but there may well be incompatibility
1588 anyway because of the rewritten CRT in VS2015 (e.g., see
1589 discussion at <http://stackoverflow.com/questions/30412951>).
1590 · It now automatically detects GCC versus Visual C and sets the
1592 VC version number on Win32.
1593 Linux
1595 Drop support for Linux a.out executable format. Linux has used ELF
1596 for over twenty years.
1597 OpenBSD 6
1599 OpenBSD 6 still does not support returning "pid", "gid", or "uid"
1600 with "SA_SIGINFO". Make sure to account for it.
1601 FreeBSD
1603 t/uni/overload.t: Skip hanging test on FreeBSD.
1604 DragonFly BSD
1606 DragonFly BSD now has support for "setproctitle()". [perl #130068]
1607 <https://rt.perl.org/Public/Bug/Display.html?id=130068>.
1608
1610 · A new API function "sv_setpv_bufsize()" allows simultaneously
1611 setting the length and the allocated size of the buffer in an "SV",
1612 growing the buffer if necessary.
1613 · A new API macro "SvPVCLEAR()" sets its "SV" argument to an empty
1615 string, like Perl-space "$x = ''", but with several optimisations.
1616 · Several new macros and functions for dealing with Unicode and
1618 UTF-8-encoded strings have been added to the API, as well as some
1619 changes in the functionality of existing functions (see "Unicode
1620 Support" in perlapi for more details):
1621 · New versions of the API macros like "isALPHA_utf8" and
1623 "toLOWER_utf8" have been added, each with the suffix "_safe",
1624 like "isSPACE_utf8_safe". These take an extra parameter,
1625 giving an upper limit of how far into the string it is safe to
1626 read. Using the old versions could cause attempts to read
1627 beyond the end of the input buffer if the UTF-8 is not well-
1628 formed, and their use now raises a deprecation warning.
1629 Details are at "Character classification" in perlapi.
1630 · Macros like "isALPHA_utf8" and "toLOWER_utf8" now die if they
1632 detect that their input UTF-8 is malformed. A deprecation
1633 warning had been issued since Perl 5.18.
1634 · Several new macros for analysing the validity of utf8
1636 sequences. These are:
1637 "UTF8_GOT_ABOVE_31_BIT" "UTF8_GOT_CONTINUATION"
1639 "UTF8_GOT_EMPTY" "UTF8_GOT_LONG" "UTF8_GOT_NONCHAR"
1640 "UTF8_GOT_NON_CONTINUATION" "UTF8_GOT_OVERFLOW"
1641 "UTF8_GOT_SHORT" "UTF8_GOT_SUPER" "UTF8_GOT_SURROGATE"
1642 "UTF8_IS_INVARIANT" "UTF8_IS_NONCHAR" "UTF8_IS_SUPER"
1643 "UTF8_IS_SURROGATE" "UVCHR_IS_INVARIANT" "isUTF8_CHAR_flags"
1644 "isSTRICT_UTF8_CHAR" "isC9_STRICT_UTF8_CHAR"
1645 · Functions that are all extensions of the "is_utf8_string_*()"
1647 functions, that apply various restrictions to the UTF-8
1648 recognized as valid:
1649 "is_strict_utf8_string", "is_strict_utf8_string_loc",
1651 "is_strict_utf8_string_loclen",
1652 "is_c9strict_utf8_string", "is_c9strict_utf8_string_loc",
1654 "is_c9strict_utf8_string_loclen",
1655 "is_utf8_string_flags", "is_utf8_string_loc_flags",
1657 "is_utf8_string_loclen_flags",
1658 "is_utf8_fixed_width_buf_flags",
1660 "is_utf8_fixed_width_buf_loc_flags",
1661 "is_utf8_fixed_width_buf_loclen_flags".
1662 "is_utf8_invariant_string". "is_utf8_valid_partial_char".
1664 "is_utf8_valid_partial_char_flags".
1665 · The functions "utf8n_to_uvchr" and its derivatives have had
1667 several changes of behaviour.
1668 Calling them, while passing a string length of 0 is now
1670 asserted against in DEBUGGING builds, and otherwise, returns
1671 the Unicode REPLACEMENT CHARACTER. If you have nothing to
1672 decode, you shouldn't call the decode function.
1673 They now return the Unicode REPLACEMENT CHARACTER if called
1675 with UTF-8 that has the overlong malformation and that
1676 malformation is allowed by the input parameters. This
1677 malformation is where the UTF-8 looks valid syntactically, but
1678 there is a shorter sequence that yields the same code point.
1679 This has been forbidden since Unicode version 3.1.
1680 They now accept an input flag to allow the overflow
1682 malformation. This malformation is when the UTF-8 may be
1683 syntactically valid, but the code point it represents is not
1684 capable of being represented in the word length on the
1685 platform. What "allowed" means, in this case, is that the
1686 function doesn't return an error, and it advances the parse
1687 pointer to beyond the UTF-8 in question, but it returns the
1688 Unicode REPLACEMENT CHARACTER as the value of the code point
1689 (since the real value is not representable).
1690 They no longer abandon searching for other malformations when
1692 the first one is encountered. A call to one of these functions
1693 thus can generate multiple diagnostics, instead of just one.
1694 · "valid_utf8_to_uvchr()" has been added to the API (although it
1696 was present in core earlier). Like "utf8_to_uvchr_buf()", but
1697 assumes that the next character is well-formed. Use with
1698 caution.
1699 · A new function, "utf8n_to_uvchr_error", has been added for use
1701 by modules that need to know the details of UTF-8 malformations
1702 beyond pass/fail. Previously, the only ways to know why a
1703 sequence was ill-formed was to capture and parse the generated
1704 diagnostics or to do your own analysis.
1705 · There is now a safer version of utf8_hop(), called
1707 "utf8_hop_safe()". Unlike utf8_hop(), utf8_hop_safe() won't
1708 navigate before the beginning or after the end of the supplied
1709 buffer.
1710 · Two new functions, "utf8_hop_forward()" and "utf8_hop_back()"
1712 are similar to "utf8_hop_safe()" but are for when you know
1713 which direction you wish to travel.
1714 · Two new macros which return useful utf8 byte sequences:
1716 "BOM_UTF8"
1718 "REPLACEMENT_CHARACTER_UTF8"
1720 · Perl is now built with the "PERL_OP_PARENT" compiler define enabled
1722 by default. To disable it, use the "PERL_NO_OP_PARENT" compiler
1723 define. This flag alters how the "op_sibling" field is used in
1724 "OP" structures, and has been available optionally since perl 5.22.
1725 See "Internal Changes" in perl5220delta for more details of what
1727 this build option does.
1728 · Three new ops, "OP_ARGELEM", "OP_ARGDEFELEM", and "OP_ARGCHECK"
1730 have been added. These are intended principally to implement the
1731 individual elements of a subroutine signature, plus any overall
1732 checking required.
1733 · The "OP_PUSHRE" op has been eliminated and the "OP_SPLIT" op has
1735 been changed from class "LISTOP" to "PMOP".
1736 Formerly the first child of a split would be a "pushre", which
1738 would have the "split"'s regex attached to it. Now the regex is
1739 attached directly to the "split" op, and the "pushre" has been
1740 eliminated.
1741 · The "op_class()" API function has been added. This is like the
1743 existing "OP_CLASS()" macro, but can more accurately determine what
1744 struct an op has been allocated as. For example "OP_CLASS()" might
1745 return "OA_BASEOP_OR_UNOP" indicating that ops of this type are
1746 usually allocated as an "OP" or "UNOP"; while "op_class()" will
1747 return "OPclass_BASEOP" or "OPclass_UNOP" as appropriate.
1748 · All parts of the internals now agree that the "sassign" op is a
1750 "BINOP"; previously it was listed as a "BASEOP" in regen/opcodes,
1751 which meant that several parts of the internals had to be special-
1752 cased to accommodate it. This oddity's original motivation was to
1753 handle code like "$x ||= 1"; that is now handled in a simpler way.
1754 · The output format of the "op_dump()" function (as used by "perl
1756 -Dx") has changed: it now displays an "ASCII-art" tree structure,
1757 and shows more low-level details about each op, such as its address
1758 and class.
1759 · The "PADOFFSET" type has changed from being unsigned to signed, and
1761 several pad-related variables such as "PL_padix" have changed from
1762 being of type "I32" to type "PADOFFSET".
1763 · The "DEBUGGING"-mode output for regex compilation and execution has
1765 been enhanced.
1766 · Several obscure SV flags have been eliminated, sometimes along with
1768 the macros which manipulate them: "SVpbm_VALID", "SVpbm_TAIL",
1769 "SvTAIL_on", "SvTAIL_off", "SVrepl_EVAL", "SvEVALED".
1770 · An OP "op_private" flag has been eliminated: "OPpRUNTIME". This
1772 used to often get set on "PMOP" ops, but had become meaningless
1773 over time.
1774
1776 · Perl no longer panics when switching into some locales on machines
1777 with buggy "strxfrm()" implementations in their libc. [perl
1778 #121734] <https://rt.perl.org/Public/Bug/Display.html?id=121734>
1779 · " $-{$name} " would leak an "AV" on each access if the regular
1781 expression had no named captures. The same applies to access to
1782 any hash tied with Tie::Hash::NamedCapture and "all => 1". [perl
1783 #130822] <https://rt.perl.org/Public/Bug/Display.html?id=130822>
1784 · Attempting to use the deprecated variable $# as the object in an
1786 indirect object method call could cause a heap use after free or
1787 buffer overflow. [perl #129274]
1788 <https://rt.perl.org/Public/Bug/Display.html?id=129274>
1789 · When checking for an indirect object method call, in some rare
1791 cases the parser could reallocate the line buffer but then continue
1792 to use pointers to the old buffer. [perl #129190]
1793 <https://rt.perl.org/Public/Bug/Display.html?id=129190>
1794 · Supplying a glob as the format argument to "formline" would cause
1796 an assertion failure. [perl #130722]
1797 <https://rt.perl.org/Public/Bug/Display.html?id=130722>
1798 · Code like " $value1 =~ qr/.../ ~~ $value2 " would have the match
1800 converted into a "qr//" operator, leaving extra elements on the
1801 stack to confuse any surrounding expression. [perl #130705]
1802 <https://rt.perl.org/Public/Bug/Display.html?id=130705>
1803 · Since v5.24 in some obscure cases, a regex which included code
1805 blocks from multiple sources (e.g., via embedded via "qr//"
1806 objects) could end up with the wrong current pad and crash or give
1807 weird results. [perl #129881]
1808 <https://rt.perl.org/Public/Bug/Display.html?id=129881>
1809 · Occasionally "local()"s in a code block within a patterns weren't
1811 being undone when the pattern matching backtracked over the code
1812 block. [perl #126697]
1813 <https://rt.perl.org/Public/Bug/Display.html?id=126697>
1814 · Using "substr()" to modify a magic variable could access freed
1816 memory in some cases. [perl #129340]
1817 <https://rt.perl.org/Public/Bug/Display.html?id=129340>
1818 · Under "use utf8", the entire source code is now checked for being
1820 UTF-8 well formed, not just quoted strings as before. [perl
1821 #126310] <https://rt.perl.org/Public/Bug/Display.html?id=126310>.
1822 · The range operator ".." on strings now handles its arguments
1824 correctly when in the scope of the "unicode_strings" feature. The
1825 previous behaviour was sufficiently unexpected that we believe no
1826 correct program could have made use of it.
1827 · The "split" operator did not ensure enough space was allocated for
1829 its return value in scalar context. It could then write a single
1830 pointer immediately beyond the end of the memory block allocated
1831 for the stack. [perl #130262]
1832 <https://rt.perl.org/Public/Bug/Display.html?id=130262>
1833 · Using a large code point with the "W" pack template character with
1835 the current output position aligned at just the right point could
1836 cause a write of a single zero byte immediately beyond the end of
1837 an allocated buffer. [perl #129149]
1838 <https://rt.perl.org/Public/Bug/Display.html?id=129149>
1839 · Supplying a format's picture argument as part of the format
1841 argument list where the picture specifies modifying the argument
1842 could cause an access to the new freed compiled form.at. [perl
1843 #129125] <https://rt.perl.org/Public/Bug/Display.html?id=129125>
1844 · The sort() operator's built-in numeric comparison function didn't
1846 handle large integers that weren't exactly representable by a
1847 double. This now uses the same code used to implement the "<=>"
1848 operator. [perl #130335]
1849 <https://rt.perl.org/Public/Bug/Display.html?id=130335>
1850 · Fix issues with "/(?{ ... <<EOF })/" that broke Method::Signatures.
1852 [perl #130398]
1853 <https://rt.perl.org/Public/Bug/Display.html?id=130398>
1854 · Fixed an assertion failure with "chop" and "chomp", which could be
1856 triggered by "chop(@x =~ tr/1/1/)". [perl #130198]
1857 <https://rt.perl.org/Public/Bug/Display.html?id=130198>.
1858 · Fixed a comment skipping error in patterns under "/x"; it could
1860 stop skipping a byte early, which could be in the middle of a UTF-8
1861 character. [perl #130495]
1862 <https://rt.perl.org/Public/Bug/Display.html?id=130495>.
1863 · perldb now ignores /dev/tty on non-Unix systems. [perl #113960]
1865 <https://rt.perl.org/Public/Bug/Display.html?id=113960>;
1866 · Fix assertion failure for "{}->$x" when $x isn't defined. [perl
1868 #130496] <https://rt.perl.org/Public/Bug/Display.html?id=130496>.
1869 · Fix an assertion error which could be triggered when a lookahead
1871 string in patterns exceeded a minimum length. [perl #130522]
1872 <https://rt.perl.org/Public/Bug/Display.html?id=130522>.
1873 · Only warn once per literal number about a misplaced "_". [perl
1875 #70878] <https://rt.perl.org/Public/Bug/Display.html?id=70878>.
1876 · The "tr///" parse code could be looking at uninitialized data after
1878 a perse error. [perl #129342]
1879 <https://rt.perl.org/Public/Bug/Display.html?id=129342>.
1880 · In a pattern match, a back-reference ("\1") to an unmatched capture
1882 could read back beyond the start of the string being matched.
1883 [perl #129377]
1884 <https://rt.perl.org/Public/Bug/Display.html?id=129377>.
1885 · "use re 'strict'" is supposed to warn if you use a range (such as
1887 "/(?[ [ X-Y ] ])/") whose start and end digit aren't from the same
1888 group of 10. It didn't do that for five groups of mathematical
1889 digits starting at "U+1D7E".
1890 · A sub containing a "forward" declaration with the same name (e.g.,
1892 "sub c { sub c; }") could sometimes crash or loop infinitely.
1893 [perl #129090]
1894 <https://rt.perl.org/Public/Bug/Display.html?id=129090>
1895 · A crash in executing a regex with a non-anchored UTF-8 substring
1897 against a target string that also used UTF-8 has been fixed. [perl
1898 #129350] <https://rt.perl.org/Public/Bug/Display.html?id=129350>
1899 · Previously, a shebang line like "#!perl -i u" could be erroneously
1901 interpreted as requesting the "-u" option. This has been fixed.
1902 [perl #129336]
1903 <https://rt.perl.org/Public/Bug/Display.html?id=129336>
1904 · The regex engine was previously producing incorrect results in some
1906 rare situations when backtracking past an alternation that matches
1907 only one thing; this showed up as capture buffers ($1, $2, etc.)
1908 erroneously containing data from regex execution paths that weren't
1909 actually executed for the final match. [perl #129897]
1910 <https://rt.perl.org/Public/Bug/Display.html?id=129897>
1911 · Certain regexes making use of the experimental "regex_sets" feature
1913 could trigger an assertion failure. This has been fixed. [perl
1914 #129322] <https://rt.perl.org/Public/Bug/Display.html?id=129322>
1915 · Invalid assignments to a reference constructor (e.g., "\eval=time")
1917 could sometimes crash in addition to giving a syntax error. [perl
1918 #125679] <https://rt.perl.org/Public/Bug/Display.html?id=125679>
1919 · The parser could sometimes crash if a bareword came after
1921 "evalbytes". [perl #129196]
1922 <https://rt.perl.org/Public/Bug/Display.html?id=129196>
1923 · Autoloading via a method call would warn erroneously ("Use of
1925 inherited AUTOLOAD for non-method") if there was a stub present in
1926 the package into which the invocant had been blessed. The warning
1927 is no longer emitted in such circumstances. [perl #47047]
1928 <https://rt.perl.org/Public/Bug/Display.html?id=47047>
1929 · The use of "splice" on arrays with non-existent elements could
1931 cause other operators to crash. [perl #129164]
1932 <https://rt.perl.org/Public/Bug/Display.html?id=129164>
1933 · A possible buffer overrun when a pattern contains a fixed utf8
1935 substring. [perl #129012]
1936 <https://rt.perl.org/Public/Bug/Display.html?id=129012>
1937 · Fixed two possible use-after-free bugs in perl's lexer. [perl
1939 #129069] <https://rt.perl.org/Public/Bug/Display.html?id=129069>
1940 · Fixed a crash with "s///l" where it thought it was dealing with
1942 UTF-8 when it wasn't. [perl #129038]
1943 <https://rt.perl.org/Public/Bug/Display.html?id=129038>
1944 · Fixed a place where the regex parser was not setting the syntax
1946 error correctly on a syntactically incorrect pattern. [perl
1947 #129122] <https://rt.perl.org/Public/Bug/Display.html?id=129122>
1948 · The "&." operator (and the "&" operator, when it treats its
1950 arguments as strings) were failing to append a trailing null byte
1951 if at least one string was marked as utf8 internally. Many code
1952 paths (system calls, regexp compilation) still expect there to be a
1953 null byte in the string buffer just past the end of the logical
1954 string. An assertion failure was the result. [perl #129287]
1955 <https://rt.perl.org/Public/Bug/Display.html?id=129287>
1956 · Avoid a heap-after-use error in the parser when creating an error
1958 messge for a syntactically invalid heredoc. [perl #128988]
1959 <https://rt.perl.org/Public/Bug/Display.html?id=128988>
1960 · Fix a segfault when run with "-DC" options on DEBUGGING builds.
1962 [perl #129106]
1963 <https://rt.perl.org/Public/Bug/Display.html?id=129106>
1964 · Fixed the parser error handling in subroutine attributes for an
1966 '":attr(foo"' that does not have an ending '")"'.
1967 · Fix the perl lexer to correctly handle a backslash as the last char
1969 in quoted-string context. This actually fixed two bugs, [perl
1970 #129064] <https://rt.perl.org/Public/Bug/Display.html?id=129064>
1971 and [perl #129176]
1972 <https://rt.perl.org/Public/Bug/Display.html?id=129176>.
1973 · In the API function "gv_fetchmethod_pvn_flags", rework separator
1975 parsing to prevent possible string overrun with an invalid "len"
1976 argument. [perl #129267]
1977 <https://rt.perl.org/Public/Bug/Display.html?id=129267>
1978 · Problems with in-place array sorts: code like "@a = sort { ... }
1980 @a", where the source and destination of the sort are the same
1981 plain array, are optimised to do less copying around. Two side-
1982 effects of this optimisation were that the contents of @a as seen
1983 by sort routines were partially sorted; and under some
1984 circumstances accessing @a during the sort could crash the
1985 interpreter. Both these issues have been fixed, and Sort functions
1986 see the original value of @a. [perl #128340]
1987 <https://rt.perl.org/Public/Bug/Display.html?id=128340>
1988 · Non-ASCII string delimiters are now reported correctly in error
1990 messages for unterminated strings. [perl #128701]
1991 <https://rt.perl.org/Public/Bug/Display.html?id=128701>
1992 · "pack("p", ...)" used to emit its warning ("Attempt to pack pointer
1994 to temporary value") erroneously in some cases, but has been fixed.
1995 · @DB::args is now exempt from "used once" warnings. The warnings
1997 only occurred under -w, because warnings.pm itself uses @DB::args
1998 multiple times.
1999 · The use of built-in arrays or hash slices in a double-quoted string
2001 no longer issues a warning ("Possible unintended interpolation...")
2002 if the variable has not been mentioned before. This affected code
2003 like "qq|@DB::args|" and "qq|@SIG{'CHLD', 'HUP'}|". (The special
2004 variables "@-" and "@+" were already exempt from the warning.)
2005 · "gethostent" and similar functions now perform a null check
2007 internally, to avoid crashing with the torsocks library. This was
2008 a regression from v5.22. [perl #128740]
2009 <https://rt.perl.org/Public/Bug/Display.html?id=128740>
2010 · "defined *{'!'}", "defined *{'['}", and "defined *{'-'}" no longer
2012 leak memory if the typeglob in question has never been accessed
2013 before.
2014 · Mentioning the same constant twice in a row (which is a syntax
2016 error) no longer fails an assertion under debugging builds. This
2017 was a regression from v5.20. [perl #126482]
2018 <https://rt.perl.org/Public/Bug/Display.html?id=126482>
2019 · Many issues relating to "printf "%a"" of hexadecimal floating point
2021 were fixed. In addition, the "subnormals" (formerly known as
2022 "denormals") floating point numbers are now supported both with the
2023 plain IEEE 754 floating point numbers (64-bit or 128-bit) and the
2024 x86 80-bit "extended precision". Note that subnormal hexadecimal
2025 floating point literals will give a warning about "exponent
2026 underflow". [perl #128843]
2027 <https://rt.perl.org/Public/Bug/Display.html?id=128843> [perl
2028 #128889] <https://rt.perl.org/Public/Bug/Display.html?id=128889>
2029 [perl #128890]
2030 <https://rt.perl.org/Public/Bug/Display.html?id=128890> [perl
2031 #128893] <https://rt.perl.org/Public/Bug/Display.html?id=128893>
2032 [perl #128909]
2033 <https://rt.perl.org/Public/Bug/Display.html?id=128909> [perl
2034 #128919] <https://rt.perl.org/Public/Bug/Display.html?id=128919>
2035 · A regression in v5.24 with "tr/\N{U+...}/foo/" when the code point
2037 was between 128 and 255 has been fixed. [perl #128734]
2038 <https://rt.perl.org/Public/Bug/Display.html?id=128734>.
2039 · Use of a string delimiter whose code point is above 2**31 now works
2041 correctly on platforms that allow this. Previously, certain
2042 characters, due to truncation, would be confused with other
2043 delimiter characters with special meaning (such as "?" in
2044 "m?...?"), resulting in inconsistent behaviour. Note that this is
2045 non-portable, and is based on Perl's extension to UTF-8, and is
2046 probably not displayable nor enterable by any editor. [perl
2047 #128738] <https://rt.perl.org/Public/Bug/Display.html?id=128738>
2048 · "@{x" followed by a newline where "x" represents a control or non-
2050 ASCII character no longer produces a garbled syntax error message
2051 or a crash. [perl #128951]
2052 <https://rt.perl.org/Public/Bug/Display.html?id=128951>
2053 · An assertion failure with "%: = 0" has been fixed. [perl #128238]
2055 <https://rt.perl.org/Public/Bug/Display.html?id=128238>
2056 · In Perl 5.18, the parsing of "$foo::$bar" was accidentally changed,
2058 such that it would be treated as "$foo."::".$bar". The previous
2059 behavior, which was to parse it as "$foo:: . $bar", has been
2060 restored. [perl #128478]
2061 <https://rt.perl.org/Public/Bug/Display.html?id=128478>
2062 · Since Perl 5.20, line numbers have been off by one when perl is
2064 invoked with the -x switch. This has been fixed. [perl #128508]
2065 <https://rt.perl.org/Public/Bug/Display.html?id=128508>
2066 · Vivifying a subroutine stub in a deleted stash (e.g., "delete
2068 $My::{"Foo::"}; \&My::Foo::foo") no longer crashes. It had begun
2069 crashing in Perl 5.18. [perl #128532]
2070 <https://rt.perl.org/Public/Bug/Display.html?id=128532>
2071 · Some obscure cases of subroutines and file handles being freed at
2073 the same time could result in crashes, but have been fixed. The
2074 crash was introduced in Perl 5.22. [perl #128597]
2075 <https://rt.perl.org/Public/Bug/Display.html?id=128597>
2076 · Code that looks for a variable name associated with an
2078 uninitialized value could cause an assertion failure in cases where
2079 magic is involved, such as $ISA[0][0]. This has now been fixed.
2080 [perl #128253]
2081 <https://rt.perl.org/Public/Bug/Display.html?id=128253>
2082 · A crash caused by code generating the warning "Subroutine
2084 STASH::NAME redefined" in cases such as "sub P::f{} undef *P::;
2085 *P::f =sub{};" has been fixed. In these cases, where the STASH is
2086 missing, the warning will now appear as "Subroutine NAME
2087 redefined". [perl #128257]
2088 <https://rt.perl.org/Public/Bug/Display.html?id=128257>
2089 · Fixed an assertion triggered by some code that handles deprecated
2091 behavior in formats, e.g., in cases like this:
2092 format STDOUT =
2094 @
2095 0"$x"
2096 [perl #128255]
2098 <https://rt.perl.org/Public/Bug/Display.html?id=128255>
2099 · A possible divide by zero in string transformation code on Windows
2101 has been avoided, fixing a crash when collating an empty string.
2102 [perl #128618]
2103 <https://rt.perl.org/Public/Bug/Display.html?id=128618>
2104 · Some regular expression parsing glitches could lead to assertion
2106 failures with regular expressions such as "/(?<=/" and "/(?<!/".
2107 This has now been fixed. [perl #128170]
2108 <https://rt.perl.org/Public/Bug/Display.html?id=128170>
2109 · " until ($x = 1) { ... } " and " ... until $x = 1 " now properly
2111 warn when syntax warnings are enabled. [perl #127333]
2112 <https://rt.perl.org/Public/Bug/Display.html?id=127333>
2113 · socket() now leaves the error code returned by the system in $! on
2115 failure. [perl #128316]
2116 <https://rt.perl.org/Public/Bug/Display.html?id=128316>
2117 · Assignment variants of any bitwise ops under the "bitwise" feature
2119 would crash if the left-hand side was an array or hash. [perl
2120 #128204] <https://rt.perl.org/Public/Bug/Display.html?id=128204>
2121 · "require" followed by a single colon (as in "foo() ? require : ..."
2123 is now parsed correctly as "require" with implicit $_, rather than
2124 "require """. [perl #128307]
2125 <https://rt.perl.org/Public/Bug/Display.html?id=128307>
2126 · Scalar "keys %hash" can now be assigned to consistently in all
2128 scalar lvalue contexts. Previously it worked for some contexts but
2129 not others.
2130 · List assignment to "vec" or "substr" with an array or hash for its
2132 first argument used to result in crashes or "Can't coerce" error
2133 messages at run time, unlike scalar assignment, which would give an
2134 error at compile time. List assignment now gives a compile-time
2135 error, too. [perl #128260]
2136 <https://rt.perl.org/Public/Bug/Display.html?id=128260>
2137 · Expressions containing an "&&" or "||" operator (or their synonyms
2139 "and" and "or") were being compiled incorrectly in some cases. If
2140 the left-hand side consisted of either a negated bareword constant
2141 or a negated "do {}" block containing a constant expression, and
2142 the right-hand side consisted of a negated non-foldable expression,
2143 one of the negations was effectively ignored. The same was true of
2144 "if" and "unless" statement modifiers, though with the left-hand
2145 and right-hand sides swapped. This long-standing bug has now been
2146 fixed. [perl #127952]
2147 <https://rt.perl.org/Public/Bug/Display.html?id=127952>
2148 · "reset" with an argument no longer crashes when encountering stash
2150 entries other than globs. [perl #128106]
2151 <https://rt.perl.org/Public/Bug/Display.html?id=128106>
2152 · Assignment of hashes to, and deletion of, typeglobs named *::::::
2154 no longer causes crashes. [perl #128086]
2155 <https://rt.perl.org/Public/Bug/Display.html?id=128086>
2156 · Perl wasn't correctly handling true/false values in the LHS of a
2158 list assign; specifically the truth values returned by boolean
2159 operators. This could trigger an assertion failure in something
2160 like the following:
2161 for ($x > $y) {
2163 ($_, ...) = (...); # here $_ is aliased to a truth value
2164 }
2165 This was a regression from v5.24. [perl #129991]
2167 <https://rt.perl.org/Public/Bug/Display.html?id=129991>
2168 · Assertion failure with user-defined Unicode-like properties. [perl
2170 #130010] <https://rt.perl.org/Public/Bug/Display.html?id=130010>
2171 · Fix error message for unclosed "\N{" in a regex. An unclosed "\N{"
2173 could give the wrong error message: "\N{NAME} must be resolved by
2174 the lexer".
2175 · List assignment in list context where the LHS contained aggregates
2177 and where there were not enough RHS elements, used to skip scalar
2178 lvalues. Previously, "(($a,$b,@c,$d) = (1))" in list context
2179 returned "($a)"; now it returns "($a,$b,$d)". "(($a,$b,$c) = (1))"
2180 is unchanged: it still returns "($a,$b,$c)". This can be seen in
2181 the following:
2182 sub inc { $_++ for @_ }
2184 inc(($a,$b,@c,$d) = (10))
2185 Formerly, the values of "($a,$b,$d)" would be left as
2187 "(11,undef,undef)"; now they are "(11,1,1)".
2188 · Code like this: "/(?{ s!!! })/" could trigger infinite recursion on
2190 the C stack (not the normal perl stack) when the last successful
2191 pattern in scope is itself. We avoid the segfault by simply
2192 forbidding the use of the empty pattern when it would resolve to
2193 the currently executing pattern. [perl #129903]
2194 <https://rt.perl.org/Public/Bug/Display.html?id=129903>
2195 · Avoid reading beyond the end of the line buffer in perl's lexer
2197 when there's a short UTF-8 character at the end. [perl #128997]
2198 <https://rt.perl.org/Public/Bug/Display.html?id=128997>
2199 · Alternations in regular expressions were sometimes failing to match
2201 a utf8 string against a utf8 alternate. [perl #129950]
2202 <https://rt.perl.org/Public/Bug/Display.html?id=129950>
2203 · Make "do "a\0b"" fail silently (and return "undef" and set $!)
2205 instead of throwing an error. [perl #129928]
2206 <https://rt.perl.org/Public/Bug/Display.html?id=129928>
2207 · "chdir" with no argument didn't ensure that there was stack space
2209 available for returning its result. [perl #129130]
2210 <https://rt.perl.org/Public/Bug/Display.html?id=129130>
2211 · All error messages related to "do" now refer to "do"; some formerly
2213 claimed to be from "require" instead.
2214 · Executing "undef $x" where $x is tied or magical no longer
2216 incorrectly blames the variable for an uninitialized-value warning
2217 encountered by the tied/magical code.
2218 · Code like "$x = $x . "a"" was incorrectly failing to yield a use of
2220 uninitialized value warning when $x was a lexical variable with an
2221 undefined value. That has now been fixed. [perl #127877]
2222 <https://rt.perl.org/Public/Bug/Display.html?id=127877>
2223 · "undef *_; shift" or "undef *_; pop" inside a subroutine, with no
2225 argument to "shift" or "pop", began crashing in Perl 5.14, but has
2226 now been fixed.
2227 · "string$scalar->$*" now correctly prefers concatenation overloading
2229 to string overloading if "$scalar->$*" returns an overloaded
2230 object, bringing it into consistency with $$scalar.
2231 · "/@0{0*->@*/*0" and similar contortions used to crash, but no
2233 longer do, but merely produce a syntax error. [perl #128171]
2234 <https://rt.perl.org/Public/Bug/Display.html?id=128171>
2235 · "do" or "require" with an argument which is a reference or typeglob
2237 which, when stringified, contains a null character, started
2238 crashing in Perl 5.20, but has now been fixed. [perl #128182]
2239 <https://rt.perl.org/Public/Bug/Display.html?id=128182>
2240 · Improve the error message for a missing "tie()" package/method.
2242 This brings the error messages in line with the ones used for
2243 normal method calls.
2244 · Parsing bad POSIX charclasses no longer leaks memory. [perl
2246 #128313] <https://rt.perl.org/Public/Bug/Display.html?id=128313>
2247
2249 · G++ 6 handles subnormal (denormal) floating point values
2250 differently than gcc 6 or g++ 5 resulting in "flush-to-zero". The
2251 end result is that if you specify very small values using the
2252 hexadecimal floating point format, like "0x1.fffffffffffffp-1022",
2253 they become zeros. [perl #131388]
2254 <https://rt.perl.org/Ticket/Display.html?id=131388>
2255
2257 · Fixed issues with recursive regexes. The behavior was fixed in
2258 Perl 5.24. [perl #126182]
2259 <https://rt.perl.org/Public/Bug/Display.html?id=126182>
2260
2262 Jon Portnoy (AVENJ), a prolific Perl author and admired Gentoo
2263 community member, has passed away on August 10, 2016. He will be
2264 remembered and missed by all those who he came in contact with, and
2265 enriched with his intellect, wit, and spirit.
2266 It is with great sadness that we also note Kip Hampton's passing.
2268 Probably best known as the author of the Perl & XML column on XML.com,
2269 he was a core contributor to AxKit, an XML server platform that became
2270 an Apache Foundation project. He was a frequent speaker in the early
2271 days at OSCON, and most recently at YAPC::NA in Madison. He was
2272 frequently on irc.perl.org as ubu, generally in the #axkit-dahut
2273 community, the group responsible for YAPC::NA Asheville in 2011.
2274 Kip and his constant contributions to the community will be greatly
2276 missed.
2277
2279 Perl 5.26.0 represents approximately 13 months of development since
2280 Perl 5.24.0 and contains approximately 360,000 lines of changes across
2281 2,600 files from 86 authors.
2282 Excluding auto-generated files, documentation and release tools, there
2284 were approximately 230,000 lines of changes to 1,800 .pm, .t, .c and .h
2285 files.
2286 Perl continues to flourish into its third decade thanks to a vibrant
2288 community of users and developers. The following people are known to
2289 have contributed the improvements that became Perl 5.26.0:
2290 Aaron Crane, Abigail, AEvar Arnfjoerd` Bjarmason, Alex Vandiver, Andreas
2292 Koenig, Andreas Voegele, Andrew Fresh, Andy Lester, Aristotle
2293 Pagaltzis, Chad Granum, Chase Whitener, Chris 'BinGOs' Williams, Chris
2294 Lamb, Christian Hansen, Christian Millour, Colin Newell, Craig A.
2295 Berry, Dagfinn Ilmari Mannsaaker, Dan Collins, Daniel Dragan, Dave
2296 Cross, Dave Rolsky, David Golden, David H. Gutteridge, David Mitchell,
2297 Dominic Hargreaves, Doug Bell, E. Choroba, Ed Avis, Father
2298 Chrysostomos, Francois Perrad, Hauke D, H.Merijn Brand, Hugo van der
2299 Sanden, Ivan Pozdeev, James E Keenan, James Raspass, Jarkko Hietaniemi,
2300 Jerry D. Hedden, Jim Cromie, J. Nick Koston, John Lightsey, Karen
2301 Etheridge, Karl Williamson, Leon Timmermans, Lukas Mai, Matthew
2302 Horsfall, Maxwell Carey, Misty De Meo, Neil Bowers, Nicholas Clark,
2303 Nicolas R., Niko Tyni, Pali, Paul Marquess, Peter Avalos, Petr PisaX,
2304 Pino Toscano, Rafael Garcia-Suarez, Reini Urban, Renee Baecker, Ricardo
2305 Signes, Richard Levitte, Rick Delaney, Salvador Fandin~o, Samuel
2306 Thibault, Sawyer X, Sebastien Aperghis-Tramoni, Sergey Aleynikov,
2307 Shlomi Fish, Smylers, Stefan Seifert, Steffen Mueller, Stevan Little,
2308 Steve Hay, Steven Humphrey, Sullivan Beck, Theo Buehler, Thomas Sibley,
2309 Todd Rinaldo, Tomasz Konojacki, Tony Cook, Unicode Consortium, Yaroslav
2310 Kuzmin, Yves Orton, Zefram.
2311 The list above is almost certainly incomplete as it is automatically
2313 generated from version control history. In particular, it does not
2314 include the names of the (very much appreciated) contributors who
2315 reported issues to the Perl bug tracker.
2316 Many of the changes included in this version originated in the CPAN
2318 modules included in Perl's core. We're grateful to the entire CPAN
2319 community for helping Perl to flourish.
2320 For a more complete list of all of Perl's historical contributors,
2322 please see the AUTHORS file in the Perl source distribution.
2323
2325 If you find what you think is a bug, you might check the perl bug
2326 database at <https://rt.perl.org/>. There may also be information at
2327 <http://www.perl.org/>, the Perl Home Page.
2328 If you believe you have an unreported bug, please run the perlbug
2330 program included with your release. Be sure to trim your bug down to a
2331 tiny but sufficient test case. Your bug report, along with the output
2332 of "perl -V", will be sent off to "perlbug@perl.org" to be analysed by
2333 the Perl porting team.
2334 If the bug you are reporting has security implications which make it
2336 inappropriate to send to a publicly archived mailing list, then see
2337 "SECURITY VULNERABILITY CONTACT INFORMATION" in perlsec for details of
2338 how to report the issue.
2339
2341 If you wish to thank the Perl 5 Porters for the work we had done in
2342 Perl 5, you can do so by running the "perlthanks" program:
2343 perlthanks
2345 This will send an email to the Perl 5 Porters list with your show of
2347 thanks.
2348
2350 The Changes file for an explanation of how to view exhaustive details
2351 on what changed.
2352 The INSTALL file for how to build Perl.
2354 The README file for general stuff.
2356 The Artistic and Copying files for copyright information.
2358perl v5.26.3 2018-03-23 PERL5260DELTA(1)