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1=encoding utf8
2
3=head1 NAME
4
2c8edc25 5perldelta - what is new for perl v5.26.0
eabfc7bc 6
2cfe9b50 7=head1 DESCRIPTION
eabfc7bc 8
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9This document describes the differences between the 5.24.0 release and the
105.26.0 release.
11
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12=head1 Notice
13
16beba24 14This release includes three updates with widespread effects:
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15
16=over 4
17
df48f9a4 18=item * C<"."> no longer in C<@INC>
89853d76 19
df48f9a4 20For security reasons, the current directory (C<".">) is no longer included
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21by default at the end of the module search path (C<@INC>). This may have
22widespread implications for the building, testing and installing of
23modules, and for the execution of scripts. See the section
48e85ff2 24L<< Removal of the current directory (C<".">) from C<@INC> >>
8ab76fe6 25for the full details.
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26
27=item * C<do> may now warn
28
8928e7db 29C<do> now gives a deprecation warning when it fails to load a file which
df48f9a4 30it would have loaded had C<"."> been in C<@INC>.
89853d76 31
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32=item * In regular expression patterns, a literal left brace C<"{">
33should be escaped
34
35See L</Unescaped literal C<"{"> characters in regular expression patterns are no longer permissible>.
36
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37=back
38
2c8edc25 39=head1 Core Enhancements
f3ed8cbf 40
22a7b456 41=head2 Lexical subroutines are no longer experimental
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43Using the C<lexical_subs> feature introduced in v5.18 no longer emits a warning. Existing
44code that disables the C<experimental::lexical_subs> warning category
45that the feature previously used will continue to work. The
46C<lexical_subs> feature has no effect; all Perl code can use lexical
47subroutines, regardless of what feature declarations are in scope.
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48
49=head2 Indented Here-documents
50
df48f9a4 51This adds a new modifier C<"~"> to here-docs that tells the parser
0f032fe1 52that it should look for C</^\s*$DELIM\n/> as the closing delimiter.
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53
54These syntaxes are all supported:
55
56 <<~EOF;
57 <<~\EOF;
58 <<~'EOF';
59 <<~"EOF";
60 <<~`EOF`;
61 <<~ 'EOF';
62 <<~ "EOF";
63 <<~ `EOF`;
64
df48f9a4 65The C<"~"> modifier will strip, from each line in the here-doc, the
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66same whitespace that appears before the delimiter.
67
fce64130 68Newlines will be copied as-is, and lines that don't include the
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69proper beginning whitespace will cause perl to croak.
70
71For example:
72
73 if (1) {
74 print <<~EOF;
75 Hello there
76 EOF
77 }
78
79prints "Hello there\n" with no leading whitespace.
80
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81=head2 New regular expression modifier C</xx>
82
df48f9a4 83Specifying two C<"x"> characters to modify a regular expression pattern
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84does everything that a single one does, but additionally TAB and SPACE
85characters within a bracketed character class are generally ignored and
86can be added to improve readability, like
87S<C</[ ^ A-Z d-f p-x ]/xx>>. Details are at
88L<perlre/E<sol>x and E<sol>xx>.
89
0f032fe1 90=head2 C<@{^CAPTURE}>, C<%{^CAPTURE}>, and C<%{^CAPTURE_ALL}>
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91
92C<@{^CAPTURE}> exposes the capture buffers of the last match as an
95b17558 93array. So C<$1> is C<${^CAPTURE}[0]>. This is a more efficient equivalent
95013431 94to code like C<substr($matched_string,$-[0],$+[0]-$-[0])>, and you don't
95b17558 95have to keep track of the C<$matched_string> either. This variable has no
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96single character equivalent. Note that, like the other regex magic variables,
97the contents of this variable is dynamic; if you wish to store it beyond
95013431 98the lifetime of the match you must copy it to another array.
2c8edc25 99
fb5d4b1a 100C<%{^CAPTURE}> is equivalent to C<%+> (I<i.e.>, named captures). Other than
95013431 101being more self documenting there is no difference between the two forms.
2c8edc25 102
fb5d4b1a 103C<%{^CAPTURE_ALL}> is equivalent to C<%-> (I<i.e.>, all named captures).
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104Other than being more self documenting there is no difference between the
105two forms.
2c8edc25 106
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107=head2 Declaring a reference to a variable
108
109As an experimental feature, Perl now allows the referencing operator to come
110after L<C<my()>|perlfunc/my>, L<C<state()>|perlfunc/state>,
111L<C<our()>|perlfunc/our>, or L<C<local()>|perlfunc/local>. This syntax must
112be enabled with C<use feature 'declared_refs'>. It is experimental, and will
113warn by default unless C<no warnings 'experimental::refaliasing'> is in effect.
114It is intended mainly for use in assignments to references. For example:
115
116 use experimental 'refaliasing', 'declared_refs';
117 my \$a = \$b;
118
119See L<perlref/Assigning to References> for more details.
120
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121=head2 Unicode 9.0 is now supported
122
123A list of changes is at L<http://www.unicode.org/versions/Unicode9.0.0/>.
124Modules that are shipped with core Perl but not maintained by p5p do not
125necessarily support Unicode 9.0. L<Unicode::Normalize> does work on 9.0.
126
127=head2 Use of C<\p{I<script>}> uses the improved Script_Extensions property
128
129Unicode 6.0 introduced an improved form of the Script (C<sc>) property, and
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130called it Script_Extensions (C<scx>). Perl now uses this improved
131version when a property is specified as just C<\p{I<script>}>. This
132should make programs be more accurate when determining if a character is
133used in a given script, but there is a slight chance of breakage for
134programs that very specifically needed the old behavior. The meaning of
135compound forms, like C<\p{sc=I<script>}> are unchanged. See
136L<perlunicode/Scripts>.
2c8edc25 137
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138=head2 Perl can now do default collation in UTF-8 locales on platforms
139that support it
a049258c 140
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141Some platforms natively do a reasonable job of collating and sorting in
142UTF-8 locales. Perl now works with those. For portability and full
143control, L<Unicode::Collate> is still recommended, but now you may
144not need to do anything special to get good-enough results, depending on
145your application. See
146L<perllocale/Category C<LC_COLLATE>: Collation: Text Comparisons and Sorting>.
147
148=head2 Better locale collation of strings containing embedded C<NUL>
149characters
150
fce64130 151In locales that have multi-level character weights, C<NUL>s are now
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152ignored at the higher priority ones. There are still some gotchas in
153some strings, though. See
154L<perllocale/Collation of strings containing embedded C<NUL> characters>.
155
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156=head2 C<CORE> subroutines for hash and array functions callable via
157reference
158
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159The hash and array functions in the C<CORE> namespace (C<keys>, C<each>,
160C<values>, C<push>, C<pop>, C<shift>, C<unshift> and C<splice>) can now
2c8edc25 161be called with ampersand syntax (C<&CORE::keys(\%hash>) and via reference
e6abae1c 162(C<< my $k = \&CORE::keys; $k-E<gt>(\%hash) >>). Previously they could only be
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163used when inlined.
164
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165=head2 New Hash Function For 64-bit Builds
166
167We have switched to a hybrid hash function to better balance
168performance for short and long keys.
169
170For short keys, 16 bytes and under, we use an optimised variant of
171One At A Time Hard, and for longer keys we use Siphash 1-3. For very
172long keys this is a big improvement in performance. For shorter keys
173there is a modest improvement.
174
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175=head1 Security
176
df48f9a4 177=head2 Removal of the current directory (C<".">) from C<@INC>
2c8edc25 178
95b17558 179The perl binary includes a default set of paths in C<@INC>. Historically
df48f9a4 180it has also included the current directory (C<".">) as the final entry,
95b17558 181unless run with taint mode enabled (C<perl -T>). While convenient, this has
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182security implications: for example, where a script attempts to load an
183optional module when its current directory is untrusted (such as F</tmp>),
184it could load and execute code from under that directory.
185
df48f9a4 186Starting with v5.26, C<"."> is always removed by default, not just under
95b17558 187tainting. This has major implications for installing modules and executing
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188scripts.
189
190The following new features have been added to help ameliorate these
191issues.
192
193=over
194
195=item * C<Configure -Udefault_inc_excludes_dot>
196
197There is a new C<Configure> option, C<default_inc_excludes_dot> (enabled
df48f9a4 198by default) which builds a perl executable without C<".">; unsetting this
95b17558 199option using C<-U> reverts perl to the old behaviour. This may fix your
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200path issues but will reintroduce all the security concerns, so don't
201build a perl executable like this unless you're I<really> confident that
202such issues are not a concern in your environment.
203
409c12ef 204=item * C<PERL_USE_UNSAFE_INC>
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205
206There is a new environment variable recognised by the perl interpreter.
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207If this variable has the value 1 when the perl interpreter starts up,
208then C<"."> will be automatically appended to C<@INC> (except under tainting).
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209
210This allows you restore the old perl interpreter behaviour on a
95b17558 211case-by-case basis. But note that this is intended to be a temporary crutch,
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212and this feature will likely be removed in some future perl version.
213It is currently set by the C<cpan> utility and C<Test::Harness> to
fce64130 214ease installation of CPAN modules which have not been updated to handle the
95b17558 215lack of dot. Once again, don't use this unless you are sure that this
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216will not reintroduce any security concerns.
217
218=item * A new mandatory warning issued by C<do>.
219
220While it is well-known that C<use> and C<require> use C<@INC> to search
221for the file to load, many people don't realise that C<do "file"> also
df48f9a4 222searches C<@INC> if the file is a relative path. With the removal of C<".">,
89853d76 223a simple C<do "file.pl"> will fail to read in and execute C<file.pl> from
95b17558 224the current directory. Since this is commonly expected behaviour, a new
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225mandatory warning is now issued whenever C<do> fails to load a file which
226it otherwise would have found if dot had been in C<@INC>.
227
228=back
229
230Here are some things script and module authors may need to do to make
231their software work in the new regime.
232
233=over
234
235=item * Script authors
236
237If the issue is within your own code (rather than within included
95b17558 238modules), then you have two main options. Firstly, if you are confident
89853d76 239that your script will only be run within a trusted directory (under which
df48f9a4 240you expect to find trusted files and modules), then add C<"."> back into the
fce64130 241path; I<e.g.>:
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242
243 BEGIN {
244 my $dir = "/some/trusted/directory";
245 chdir $dir or die "Can't chdir to $dir: $!\n";
246 # safe now
247 push @INC, '.';
248 }
249 use "Foo::Bar"; # may load /some/trusted/directory/Foo/Bar.pm
250 do "config.pl"; # may load /some/trusted/directory/config.pl
251
252On the other hand, if your script is intended to be run from within
253untrusted directories (such as F</tmp>), then your script suddenly failing
95b17558 254to load files may be indicative of a security issue. You most likely want
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255to replace any relative paths with full paths; for example,
256
257 do ".foo_config.pl"
258
259might become
260
261 do "$ENV{HOME}/.foo_config.pl"
262
263If you are absolutely certain that you want your script to load and
264execute a file from the current directory, then use a C<./> prefix; for
265example:
266
267 do "./.foo_config.pl"
268
269=item * Installing and using CPAN modules
270
271If you install a CPAN module using an automatic tool like C<cpan>, then
272this tool will itself set the C<PERL_USE_UNSAFE_INC> environment variable
273while building and testing the module, which may be sufficient to install
274a distribution which hasn't been updated to be dot-aware. If you want to
275install such a module manually, then you'll need to replace the
276traditional invocation:
277
278 perl Makefile.PL && make && make test && make install
279
280with something like
281
282 (export PERL_USE_UNSAFE_INC=1; \
283 perl Makefile.PL && make && make test && make install)
284
95b17558 285Note that this only helps build and install an unfixed module. It's
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286possible for the tests to pass (since they were run under
287C<PERL_USE_UNSAFE_INC=1>), but for the module itself to fail to perform
95b17558 288correctly in production. In this case you may have to temporarily modify
0f275d26 289your script until such time as a fixed version of the module is released.
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290For example:
291
292 use Foo::Bar;
293 {
294 local @INC = (@INC, '.');
295 # assuming read_config() needs '.' in @INC
296 $config = Foo::Bar->read_config();
297 }
298
95b17558 299This is only rarely expected to be necessary. Again, if doing this,
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300assess the resultant risks first.
301
302=item * Module Authors
303
304If you maintain a CPAN distribution, it may need updating to run in
95b17558 305a dotless environment. Although C<cpan> and other such tools will
0f275d26 306currently set the C<PERL_USE_UNSAFE_INC> during module build, this is a
df48f9a4 307temporary workaround for the set of modules which rely on C<"."> being in
95b17558 308C<@INC> for installation and testing, and this may mask deeper issues. It
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309could result in a module which passes tests and installs, but which
310fails at run time.
311
312During build, test and install, it will normally be the case that any perl
313processes will be executing directly within the root directory of the
95b17558 314untarred distribution, or a known subdirectory of that, such as F<t/>. It
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315may well be that F<Makefile.PL> or F<t/foo.t> will attempt to include
316local modules and configuration files using their direct relative
317filenames, which will now fail.
318
319However, as described above, automatic tools like F<cpan> will (for now)
320set the C<PERL_USE_UNSAFE_INC> environment variable, which introduces
321dot during build.
322
323This makes it likely that your existing build and test code will work, but
324this may mask issues with your code which only manifest when used after
95b17558 325install. It is prudent to try and run your build process with that
89853d76 326variable explicitly disabled:
0f275d26 327
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328 (export PERL_USE_UNSAFE_INC=0; \
329 perl Makefile.PL && make && make test && make install)
330
331This is more likely to show up any potential problems with your module's
95b17558 332build process, or even with the module itself. Fixing such issues will
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333ensure both that your module can again be installed manually, and that
334it will still build once the C<PERL_USE_UNSAFE_INC> crutch goes away.
335
336When fixing issues in tests due to the removal of dot from C<@INC>,
337reinsertion of dot into C<@INC> should be performed with caution, for this
95b17558 338too may suppress real errors in your runtime code. You are encouraged
89853d76 339wherever possible to apply the aforementioned approaches with explicit
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340absolute/relative paths, or to relocate your needed files into a
341subdirectory and insert that subdirectory into C<@INC> instead.
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342
343If your runtime code has problems under the dotless C<@INC>, then the comments
95b17558 344above on how to fix for script authors will mostly apply here too. Bear in
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345mind though that it is considered bad form for a module to globally add dot to
346C<@INC>, since it introduces both a security risk and hides issues of
347accidentally requiring dot in C<@INC>, as explained above.
348
349=back
2c8edc25 350
fb5d4b1a 351=head2 Escaped colons and relative paths in PATH
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352
353On Unix systems, Perl treats any relative paths in the PATH environment
354variable as tainted when starting a new process. Previously, it was
355allowing a backslash to escape a colon (unlike the OS), consequently
356allowing relative paths to be considered safe if the PATH was set to
5aeff080 357something like C</\:.>. The check has been fixed to treat C<"."> as tainted
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358in that example.
359
360=head2 C<-Di> switch is now required for PerlIO debugging output
361
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362This is used for debugging of code within PerlIO to avoid recursive
363calls. Previously this output would be sent to the file specified
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364by the C<PERLIO_DEBUG> environment variable if perl wasn't running
365setuid and the C<-T> or C<-t> switches hadn't been parsed yet.
366
367If perl performed output at a point where it hadn't yet parsed its
368switches this could result in perl creating or overwriting the file
369named by C<PERLIO_DEBUG> even when the C<-T> switch had been supplied.
370
371Perl now requires the C<-Di> switch to produce PerlIO debugging
372output. By default this is written to C<stderr>, but can optionally
373be redirected to a file by setting the C<PERLIO_DEBUG> environment
374variable.
a049258c 375
3ee934f7 376If perl is running setuid or the C<-T> switch was supplied,
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377C<PERLIO_DEBUG> is ignored and the debugging output is sent to
378C<stderr> as for any other C<-D> switch.
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379
380=head1 Incompatible Changes
381
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382=head2 Unescaped literal C<"{"> characters in regular expression
383patterns are no longer permissible
a049258c 384
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385You have to now say something like C<"\{"> or C<"[{]"> to specify to
386match a LEFT CURLY BRACKET; otherwise it is a fatal pattern compilation
387error. This change will allow future extensions to the language.
388
389These have been deprecated since v5.16, with a deprecation message
390raised for some uses starting in v5.22. Unfortunately, the code added
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391to raise the message was buggy, and failed to warn in some cases where
392it should have. Therefore, enforcement of this ban for these cases is
393deferred until Perl 5.30, but the code has been fixed to raise a
394default-on deprecation message for them in the meantime.
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395
396Some uses of literal C<"{"> occur in contexts where we do not foresee
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397the meaning ever being anything but the literal, such as the very first
398character in the pattern, or after a C<"|"> meaning alternation. Thus
399
400 qr/{fee|{fie/
401
402matches either of the strings C<{fee> or C<{fie>. To avoid forcing
403unnecessary code changes, these uses do not need to be escaped, and no
404warning is raised about them, and there are no current plans to change this.
405
406But it is always correct to escape C<"{">, and the simple rule to
407remember is to always do so.
a049258c 408
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409See L<Unescaped left brace in regex is illegal here|perldiag/Unescaped left brace in regex is illegal here in regex; marked by S<E<lt>-- HERE> in mE<sol>%sE<sol>>.
410
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411=head2 C<scalar(%hash)> return signature changed
412
413The value returned for C<scalar(%hash)> will no longer show information about
414the buckets allocated in the hash. It will simply return the count of used
415keys. It is thus equivalent to C<0+keys(%hash)>.
416
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417A form of backwards compatibility is provided via
418L<C<Hash::Util::bucket_ratio()>|Hash::Util/bucket_ratio> which provides
419the same behavior as
420C<scalar(%hash)> provided in Perl 5.24 and earlier.
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421
422=head2 C<keys> returned from an lvalue subroutine
423
424C<keys> returned from an lvalue subroutine can no longer be assigned
425to in list context.
426
427 sub foo : lvalue { keys(%INC) }
428 (foo) = 3; # death
429 sub bar : lvalue { keys(@_) }
430 (bar) = 3; # also an error
431
432This makes the lvalue sub case consistent with C<(keys %hash) = ...> and
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433C<(keys @_) = ...>, which are also errors.
434L<[perl #128187]|https://rt.perl.org/Public/Bug/Display.html?id=128187>
a049258c 435
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436=head2 C<${^ENCODING}> has been removed
437
438Consequently, the L<encoding> pragma's default mode is no longer supported. If
439you still need to write your source code in encodings other than UTF-8, use a
440source filter such as L<Filter::Encoding> on CPAN or L<encoding>'s C<Filter>
441option.
442
0f032fe1 443=head2 C<POSIX::tmpnam()> has been removed
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444
445The fundamentally unsafe C<tmpnam()> interface was deprecated in
53799a91 446Perl 5.22 and has now been removed. In its place you can use,
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447for example, the L<File::Temp> interfaces.
448
449=head2 require ::Foo::Bar is now illegal.
450
95b17558 451Formerly, C<require ::Foo::Bar> would try to read F</Foo/Bar.pm>. Now any
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452bareword require which starts with a double colon dies instead.
453
454=head2 Literal control character variable names are no longer permissible
455
456A variable name may no longer contain a literal control character under
457any circumstances. These previously were allowed in single-character
458names on ASCII platforms, but have been deprecated there since Perl
4595.20. This affects things like C<$I<\cT>>, where I<\cT> is a literal
460control (such as a C<NAK> or C<NEGATIVE ACKNOWLEDGE> character) in the
461source code.
462
463=head2 C<NBSP> is no longer permissible in C<\N{...}>
464
465The name of a character may no longer contain non-breaking spaces. It
53799a91 466has been deprecated to do so since Perl 5.22.
8d25d2f3 467
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468=head1 Deprecations
469
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470=head2 String delimiters that aren't stand-alone graphemes are now deprecated
471
472In order for Perl to eventually allow string delimiters to be Unicode
473grapheme clusters (which look like a single character, but may be
0f275d26 474a sequence of several ones), we have to stop allowing a single character
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475delimiter that isn't a grapheme by itself. These are unlikely to exist
476in actual code, as they would typically display as attached to the
477character in front of them.
478
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479=head2 C<\cI<X>> that maps to a printable is no longer deprecated
480
481This means we have no plans to remove this feature. It still raises a
482warning, but only if syntax warnings are enabled. The feature was
483originally intended to be a way to express non-printable characters that
484don't have a mnemonic (C<\t> and C<\n> are mnemonics for two
485non-printable characters, but most non-printables don't have a
486mnemonic.) But the feature can be used to specify a few printable
487characters, though those are more clearly expressed as the printable
488itself. See
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489L<http://www.nntp.perl.org/group/perl.perl5.porters/2017/02/msg242944.html>.
490
2c8edc25 491=head1 Performance Enhancements
a049258c 492
2c8edc25 493=over 4
a049258c 494
2c8edc25 495=item *
a049258c 496
fce64130 497A hash in boolean context is now sometimes faster, I<e.g.>
a049258c 498
2c8edc25 499 if (!%h) { ... }
a049258c 500
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501This was already special-cased, but some cases were missed (such as
502C<grep %$_, @AoH>, and even the ones which weren't have been improved.
a049258c 503
2c8edc25 504=item * New Faster Hash Function on 64 bit builds
a049258c 505
95b17558 506We use a different hash function for short and long keys. This should
2c8edc25 507improve performance and security, especially for long keys.
a049258c 508
2c8edc25 509=item * readline is faster
a049258c 510
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511Reading from a file line-by-line with C<readline()> or C<< E<lt>E<gt> >> should
512now typically be faster due to a better implementation of the code that
513searches for the next newline character.
514
515=item *
a049258c 516
0f032fe1 517Reduce cost of C<SvVALID()>.
a049258c 518
2c8edc25 519=item *
ad5c8857 520
2c8edc25 521C<$ref1 = $ref2> has been optimized.
5e50eae4 522
4b99a68c 523=item *
f4b40f11 524
fce64130 525Array and hash assignment are now faster, I<e.g.>
ec34c8a4 526
2c8edc25
S
527 (..., @a) = (...);
528 (..., %h) = (...);
f4b40f11 529
2c8edc25 530especially when the RHS is empty.
ec34c8a4 531
2c8edc25 532=item *
a049258c 533
2c8edc25 534Reduce the number of odd special cases for the C<SvSCREAM> flag.
e770df11 535
2c8edc25 536=item *
a049258c 537
0f032fe1 538Avoid C<sv_catpvn()> in C<do_vop()> when unneeded.
2c8edc25
S
539
540=item *
541
542Enhancements in Regex concat COW implementation.
543
544=item *
545
8928e7db
DM
546Better optimise array and hash assignment: where an array or hash appears
547in the LHS of a list assignment, such as C<(..., @a) = (...);>, it's
548likely to be considerably faster, especially if it involves emptying the
549array/hash. For example this code runs about 1/3 faster compared to
d3972b39 550Perl 5.24.0:
d053832c
AB
551
552 my @a;
8928e7db 553 for my $i (1..10_000_000) {
d053832c
AB
554 @a = (1,2,3);
555 @a = ();
556 }
557
2c8edc25
S
558
559=item *
560
561Converting a single-digit string to a number is now substantially faster.
562
563=item *
564
565The internal op implementing the C<split> builtin has been simplified and
95b17558
KW
566sped up. Firstly, it no longer requires a subsidiary internal C<pushre> op
567to do its work. Secondly, code of the form C<my @x = split(...)> is now
2c8edc25
S
568optimised in the same way as C<@x = split(...)>, and is therefore a few
569percent faster.
570
571=item *
572
573The rather slow implementation for the experimental subroutine signatures
574feature has been made much faster; it is now comparable in speed with the
575old-style C<my ($a, $b, @c) = @_>.
7ca0bfc4 576
fbe3f407
S
577=item *
578
2c8edc25 579Bareword constant strings are now permitted to take part in constant
95b17558 580folding. They were originally exempted from constant folding in August 1999,
2c8edc25 581during the development of Perl 5.6, to ensure that C<use strict "subs">
95b17558 582would still apply to bareword constants. That has now been accomplished a
2c8edc25
S
583different way, so barewords, like other constants, now gain the performance
584benefits of constant folding.
585
586This also means that void-context warnings on constant expressions of
587barewords now report the folded constant operand, rather than the operation;
588this matches the behaviour for non-bareword constants.
a049258c
S
589
590=back
591
2c8edc25
S
592=head1 Modules and Pragmata
593
a049258c
S
594=head2 Updated Modules and Pragmata
595
596=over 4
fbe3f407 597
759020c9 598=item *
7ca0bfc4 599
0cc8c746
S
600L<Archive::Tar> has been upgraded from version 2.04 to 2.24.
601
602=item *
603
604L<arybase> has been upgraded from version 0.11 to 0.12.
605
606=item *
607
608L<attributes> has been upgraded from version 0.27 to 0.29.
a049258c 609
2c8edc25 610The deprecation message for the C<:unique> and C<:locked> attributes
0f275d26 611now mention that they will disappear in Perl 5.28.
a049258c 612
2c8edc25 613=item *
a049258c 614
0cc8c746
S
615L<B> has been upgraded from version 1.62 to 1.68.
616
617=item *
618
619L<B::Concise> has been upgraded from version 0.996 to 0.999.
2c8edc25
S
620
621Its output is now more descriptive for C<op_private> flags.
d5c7a4fc 622
759020c9
S
623=item *
624
0cc8c746
S
625L<B::Debug> has been upgraded from version 1.23 to 1.24.
626
627=item *
628
629L<B::Deparse> has been upgraded from version 1.37 to 1.40.
630
631=item *
632
2c8edc25 633L<B::Xref> has been upgraded from version 1.05 to 1.06.
a049258c 634
a3a9a3d2
KW
635It now uses 3-arg C<open()> instead of 2-arg C<open()>.
636L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
a049258c 637
2c8edc25 638=item *
a049258c 639
0cc8c746
S
640L<base> has been upgraded from version 2.23 to 2.25.
641
642=item *
643
644L<bignum> has been upgraded from version 0.42 to 0.47.
645
646=item *
647
648L<Carp> has been upgraded from version 1.40 to 1.42.
649
650=item *
651
652L<charnames> has been upgraded from version 1.43 to 1.44.
653
654=item *
655
656L<Compress::Raw::Bzip2> has been upgraded from version 2.069 to 2.074.
657
658=item *
659
660L<Compress::Raw::Zlib> has been upgraded from version 2.069 to 2.074.
661
662=item *
663
664L<Config::Perl::V> has been upgraded from version 0.25 to 0.28.
665
666=item *
667
668L<CPAN> has been upgraded from version 2.11 to 2.18.
669
670=item *
671
672L<CPAN::Meta> has been upgraded from version 2.150005 to 2.150010.
673
674=item *
675
676L<Data::Dumper> has been upgraded from version 2.160 to 2.167.
a049258c 677
2c8edc25 678The XS implementation now supports Deparse.
a049258c 679
a3a9a3d2
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680This fixes a stack management bug.
681L<[perl #130487]|https://rt.perl.org/Public/Bug/Display.html?id=130487>.
a049258c 682
2c8edc25 683=item *
a049258c 684
0cc8c746
S
685L<DB_File> has been upgraded from version 1.835 to 1.840.
686
687=item *
688
689L<Devel::Peek> has been upgraded from version 1.23 to 1.26.
690
691=item *
692
693L<Devel::PPPort> has been upgraded from version 3.32 to 3.35.
694
695=item *
696
2c8edc25 697L<Devel::SelfStubber> has been upgraded from version 1.05 to 1.06.
a049258c 698
a3a9a3d2
KW
699It now uses 3-arg C<open()> instead of 2-arg C<open()>.
700L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
a049258c 701
2c8edc25 702=item *
a049258c 703
0cc8c746 704L<diagnostics> has been upgraded from version 1.34 to 1.36.
a049258c 705
a3a9a3d2
KW
706It now uses 3-arg C<open()> instead of 2-arg C<open()>.
707L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
7ca0bfc4 708
ad5c8857 709=item *
7ca0bfc4 710
0cc8c746
S
711L<Digest> has been upgraded from version 1.17 to 1.17_01.
712
713=item *
714
715L<Digest::MD5> has been upgraded from version 2.54 to 2.55.
716
717=item *
718
719L<Digest::SHA> has been upgraded from version 5.95 to 5.96.
720
721=item *
722
723L<DynaLoader> has been upgraded from version 1.38 to 1.42.
724
725=item *
726
727L<Encode> has been upgraded from version 2.80 to 2.88.
728
729=item *
730
731L<encoding> has been upgraded from version 2.17 to 2.19.
8f7edc68 732
ee8180b8 733This module's default mode is no longer supported. It now
2c8edc25 734dies when imported, unless the C<Filter> option is being used.
d5c7a4fc 735
2c8edc25 736=item *
d5c7a4fc 737
2c8edc25 738L<encoding::warnings> has been upgraded from version 0.12 to 0.13.
a049258c 739
ee8180b8 740This module is no longer supported. It emits a warning to
2c8edc25 741that effect and then does nothing.
a049258c 742
2c8edc25 743=item *
d5c7a4fc 744
0cc8c746 745L<Errno> has been upgraded from version 1.25 to 1.28.
a049258c 746
2c8edc25 747Document that using C<%!> loads Errno for you.
d5c7a4fc 748
a3a9a3d2
KW
749It now uses 3-arg C<open()> instead of 2-arg C<open()>.
750L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
3abe9611 751
c714fb1f 752=item *
3ce6a296 753
2c8edc25 754L<ExtUtils::Embed> has been upgraded from version 1.33 to 1.34.
a049258c 755
a3a9a3d2
KW
756It now uses 3-arg C<open()> instead of 2-arg C<open()>.
757L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
a049258c 758
2c8edc25 759=item *
a049258c 760
0cc8c746
S
761L<ExtUtils::MakeMaker> has been upgraded from version 7.10_01 to 7.24.
762
763=item *
764
765L<ExtUtils::Miniperl> has been upgraded from version 1.05 to 1.06.
766
767=item *
768
769L<ExtUtils::ParseXS> has been upgraded from version 3.31 to 3.34.
770
771=item *
772
773L<ExtUtils::Typemaps> has been upgraded from version 3.31 to 3.34.
774
775=item *
776
777L<feature> has been upgraded from version 1.42 to 1.47.
2c8edc25
S
778
779Fixes the Unicode Bug in the range operator.
a049258c
S
780
781=item *
5c92a635 782
0cc8c746
S
783L<File::Copy> has been upgraded from version 2.31 to 2.32.
784
785=item *
786
787L<File::Fetch> has been upgraded from version 0.48 to 0.52.
788
789=item *
790
791L<File::Glob> has been upgraded from version 1.26 to 1.28.
d5c7a4fc 792
2c8edc25 793Issue a deprecation message for C<File::Glob::glob()>.
d5c7a4fc 794
2c8edc25 795=item *
d5c7a4fc 796
0cc8c746
S
797L<File::Spec> has been upgraded from version 3.63 to 3.67.
798
799=item *
800
801L<FileHandle> has been upgraded from version 2.02 to 2.03.
802
803=item *
804
2c8edc25 805L<Filter::Simple> has been upgraded from version 0.92 to 0.93.
a049258c 806
2c8edc25 807It no longer treats C<no MyFilter> immediately following C<use MyFilter> as
a3a9a3d2
KW
808end-of-file.
809L<[perl #107726]|https://rt.perl.org/Public/Bug/Display.html?id=107726>
64afbd29
DM
810
811=item *
812
0cc8c746
S
813L<Getopt::Long> has been upgraded from version 2.48 to 2.49.
814
815=item *
816
817L<Getopt::Std> has been upgraded from version 1.11 to 1.12.
818
819=item *
820
821L<Hash::Util> has been upgraded from version 0.19 to 0.22.
822
823=item *
824
825L<HTTP::Tiny> has been upgraded from version 0.056 to 0.070.
a049258c 826
2c8edc25 827Internal 599-series errors now include the redirect history.
a049258c 828
2c8edc25 829=item *
a049258c 830
0cc8c746 831L<I18N::LangTags> has been upgraded from version 0.40 to 0.42.
a049258c 832
a3a9a3d2
KW
833It now uses 3-arg C<open()> instead of 2-arg C<open()>.
834L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
a049258c 835
2c8edc25 836=item *
a049258c 837
0cc8c746
S
838L<IO> has been upgraded from version 1.36 to 1.38.
839
840=item *
841
601d9a87 842IO-Compress has been upgraded from version 2.069 to 2.074.
0cc8c746
S
843
844=item *
845
846L<IO::Socket::IP> has been upgraded from version 0.37 to 0.38.
847
848=item *
849
850L<IPC::Cmd> has been upgraded from version 0.92 to 0.96.
851
852=item *
853
854L<IPC::SysV> has been upgraded from version 2.06_01 to 2.07.
855
856=item *
857
858L<JSON::PP> has been upgraded from version 2.27300 to 2.27400_02.
859
860=item *
861
2c8edc25
S
862L<lib> has been upgraded from version 0.63 to 0.64.
863
a3a9a3d2
KW
864It now uses 3-arg C<open()> instead of 2-arg C<open()>.
865L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
faab9793 866
c714fb1f 867=item *
ad5c8857 868
0cc8c746
S
869L<List::Util> has been upgraded from version 1.42_02 to 1.46_02.
870
871=item *
872
873L<Locale::Codes> has been upgraded from version 3.37 to 3.42.
874
875=item *
876
877L<Locale::Maketext> has been upgraded from version 1.26 to 1.28.
878
879=item *
880
881L<Locale::Maketext::Simple> has been upgraded from version 0.21 to 0.21_01.
882
883=item *
884
885L<Math::BigInt> has been upgraded from version 1.999715 to 1.999806.
ad5c8857 886
2c8edc25 887There have also been some core customizations.
ad5c8857 888
2c8edc25 889=item *
2e0dcc12 890
0cc8c746
S
891L<Math::BigInt::FastCalc> has been upgraded from version 0.40 to 0.5005.
892
893=item *
894
895L<Math::BigRat> has been upgraded from version 0.260802 to 0.2611.
896
897=item *
898
899L<Math::Complex> has been upgraded from version 1.59 to 1.5901.
900
901=item *
902
903L<Memoize> has been upgraded from version 1.03 to 1.03_01.
904
905=item *
906
907L<Module::CoreList> has been upgraded from version 5.20170420 to 5.20170520.
908
909=item *
910
911L<Module::Load::Conditional> has been upgraded from version 0.64 to 0.68.
912
913=item *
914
915L<Module::Metadata> has been upgraded from version 1.000031 to 1.000033.
916
917=item *
918
919L<mro> has been upgraded from version 1.18 to 1.20.
920
921=item *
922
923L<Net::Ping> has been upgraded from version 2.43 to 2.55.
d5c7a4fc 924
2c8edc25
S
925IPv6 addresses and C<AF_INET6> sockets are now supported, along with several
926other enhancements.
d5c7a4fc 927
2c8edc25
S
928Remove sudo from 500_ping_icmp.t.
929
930Avoid stderr noise in tests
931
0f275d26 932Check for echo in new L<Net::Ping> tests.
d5c7a4fc 933
a049258c 934=item *
d5c7a4fc 935
0cc8c746
S
936L<NEXT> has been upgraded from version 0.65 to 0.67.
937
938=item *
939
940L<Opcode> has been upgraded from version 1.34 to 1.39.
941
942=item *
943
944L<open> has been upgraded from version 1.10 to 1.11.
945
946=item *
947
2c8edc25 948L<OS2::Process> has been upgraded from version 1.11 to 1.12.
a049258c 949
a3a9a3d2
KW
950It now uses 3-arg C<open()> instead of 2-arg C<open()>.
951L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
a049258c 952
2c8edc25 953=item *
a049258c 954
2c8edc25 955L<overload> has been upgraded from version 1.26 to 1.28.
a049258c 956
2c8edc25 957Its compilation speed has been improved slightly.
a049258c 958
2c8edc25
S
959=item *
960
0cc8c746
S
961L<parent> has been upgraded from version 0.234 to 0.236.
962
963=item *
964
2c8edc25
S
965L<perl5db.pl> has been upgraded from version 1.50 to 1.51.
966
a3a9a3d2
KW
967Ignore F</dev/tty> on non-Unix systems.
968L<[perl #113960]|https://rt.perl.org/Public/Bug/Display.html?id=113960>
2c8edc25
S
969
970=item *
971
0cc8c746
S
972L<Perl::OSType> has been upgraded from version 1.009 to 1.010.
973
974=item *
975
976L<perlfaq> has been upgraded from version 5.021010 to 5.021011.
977
978=item *
979
980L<PerlIO> has been upgraded from version 1.09 to 1.10.
981
982=item *
983
984L<PerlIO::encoding> has been upgraded from version 0.24 to 0.25.
985
986=item *
987
988L<PerlIO::scalar> has been upgraded from version 0.24 to 0.26.
989
990=item *
991
992L<Pod::Checker> has been upgraded from version 1.60 to 1.73.
993
994=item *
995
996L<Pod::Functions> has been upgraded from version 1.10 to 1.11.
997
998=item *
999
1000L<Pod::Html> has been upgraded from version 1.22 to 1.2202.
1001
1002=item *
1003
1004L<Pod::Perldoc> has been upgraded from version 3.25_02 to 3.28.
1005
1006=item *
1007
1008L<Pod::Simple> has been upgraded from version 3.32 to 3.35.
1009
1010=item *
1011
1012L<Pod::Usage> has been upgraded from version 1.68 to 1.69.
1013
1014=item *
1015
95b17558 1016L<POSIX> has been upgraded from version 1.65 to 1.76. This remedies several
a3a9a3d2
KW
1017defects in making its symbols exportable.
1018L<[perl #127821]|https://rt.perl.org/Public/Bug/Display.html?id=127821>
2c8edc25
S
1019The C<POSIX::tmpnam()> interface has been removed,
1020see L</"POSIX::tmpnam() has been removed">.
1021Trying to import POSIX subs that have no real implementations
1022(like C<POSIX::atend()>) now fails at import time, instead of
1023waiting until runtime.
1024
1025=item *
1026
0cc8c746 1027L<re> has been upgraded from version 0.32 to 0.34
2c8edc25
S
1028
1029This adds support for the new L<C<E<47>xx>|perlre/E<sol>x and E<sol>xx>
1030regular expression pattern modifier, and a change to the L<S<C<use re
1031'strict'>>|re/'strict' mode> experimental feature. When S<C<re
1032'strict'>> is enabled, a warning now will be generated for all
df48f9a4 1033unescaped uses of the two characters C<"}"> and C<"]"> in regular
2c8edc25 1034expression patterns (outside bracketed character classes) that are taken
df48f9a4 1035literally. This brings them more in line with the C<")"> character which
2c8edc25
S
1036is always a metacharacter unless escaped. Being a metacharacter only
1037sometimes, depending on action at a distance, can lead to silently
1038having the pattern mean something quite different than was intended,
1039which the S<C<re 'strict'>> mode is intended to minimize.
1040
1041=item *
1042
0cc8c746
S
1043L<Safe> has been upgraded from version 2.39 to 2.40.
1044
1045=item *
1046
1047L<Scalar::Util> has been upgraded from version 1.42_02 to 1.46_02.
1048
1049=item *
1050
1051L<Storable> has been upgraded from version 2.56 to 2.62.
2c8edc25 1052
a3a9a3d2
KW
1053Fixes
1054L<[perl #130098]|https://rt.perl.org/Public/Bug/Display.html?id=130098>.
2c8edc25
S
1055
1056=item *
1057
0cc8c746
S
1058L<Symbol> has been upgraded from version 1.07 to 1.08.
1059
1060=item *
1061
1062L<Sys::Syslog> has been upgraded from version 0.33 to 0.35.
1063
1064=item *
1065
1066L<Term::ANSIColor> has been upgraded from version 4.04 to 4.06.
1067
1068=item *
1069
2c8edc25
S
1070L<Term::ReadLine> has been upgraded from version 1.15 to 1.16.
1071
a3a9a3d2
KW
1072It now uses 3-arg C<open()> instead of 2-arg C<open()>.
1073L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
2c8edc25
S
1074
1075=item *
1076
0cc8c746 1077L<Test> has been upgraded from version 1.28 to 1.30.
2c8edc25 1078
a3a9a3d2
KW
1079It now uses 3-arg C<open()> instead of 2-arg C<open()>.
1080L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
2c8edc25
S
1081
1082=item *
1083
0cc8c746
S
1084L<Test::Harness> has been upgraded from version 3.36 to 3.38.
1085
1086=item *
1087
1088L<Test::Simple> has been upgraded from version 1.001014 to 1.302073.
1089
1090=item *
1091
1092L<Thread::Queue> has been upgraded from version 3.09 to 3.12.
1093
1094=item *
1095
2c8edc25
S
1096L<Thread::Semaphore> has been upgraded from 2.12 to 2.13.
1097
1098Added the C<down_timed> method.
1099
1100=item *
1101
0cc8c746 1102L<threads> has been upgraded from version 2.07 to 2.15.
2c8edc25
S
1103
1104Compatibility with 5.8 has been restored.
1105
a3a9a3d2
KW
1106Fixes
1107L<[perl #130469]|https://rt.perl.org/Public/Bug/Display.html?id=130469>.
2c8edc25
S
1108
1109=item *
1110
0cc8c746 1111L<threads::shared> has been upgraded from version 1.51 to 1.56.
2c8edc25 1112
a3a9a3d2
KW
1113This fixes [cpan #119529],
1114L<[perl #130457]|https://rt.perl.org/Public/Bug/Display.html?id=130457>
2c8edc25
S
1115
1116=item *
1117
0cc8c746
S
1118L<Tie::Hash::NamedCapture> has been upgraded from version 0.09 to 0.10.
1119
1120=item *
1121
1122L<Time::HiRes> has been upgraded from version 1.9733 to 1.9741.
2c8edc25
S
1123
1124It now builds on systems with C++11 compilers (such as G++ 6 and Clang++
11253.9).
1126
1127Now uses C<clockid_t>.
1128
1129=item *
1130
0cc8c746
S
1131L<Time::Local> has been upgraded from version 1.2300 to 1.25.
1132
1133=item *
1134
1135L<Unicode::Collate> has been upgraded from version 1.14 to 1.19.
1136
1137=item *
1138
1139L<Unicode::UCD> has been upgraded from version 0.64 to 0.68.
2c8edc25 1140
a3a9a3d2
KW
1141It now uses 3-arg C<open()> instead of 2-arg C<open()>.
1142L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
2c8edc25
S
1143
1144=item *
1145
0cc8c746
S
1146L<version> has been upgraded from version 0.9916 to 0.9917.
1147
1148=item *
1149
1150L<VMS::DCLsym> has been upgraded from version 1.06 to 1.08.
2c8edc25 1151
a3a9a3d2
KW
1152It now uses 3-arg C<open()> instead of 2-arg C<open()>.
1153L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
a049258c
S
1154
1155=item *
1156
0cc8c746
S
1157L<warnings> has been upgraded from version 1.36 to 1.37.
1158
1159=item *
1160
1161L<XS::Typemap> has been upgraded from version 0.14 to 0.15.
1162
1163=item *
1164
1165L<XSLoader> has been upgraded from version 0.21 to 0.27.
2c8edc25
S
1166
1167Fixed a security hole in which binary files could be loaded from a path
1168outside of L<C<@INC>|perlvar/@INC>.
1169
a3a9a3d2
KW
1170It now uses 3-arg C<open()> instead of 2-arg C<open()>.
1171L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
a049258c
S
1172
1173=back
1174
2c8edc25
S
1175=head1 Documentation
1176
1177=head2 New Documentation
a049258c 1178
2c8edc25 1179=head3 L<perldeprecation>
a049258c 1180
2c8edc25 1181This file documents all upcoming deprecations, and some of the deprecations
95b17558 1182which already have been removed. The purpose of this documentation is
2c8edc25
S
1183two-fold: document what will disappear, and by which version, and serve
1184as a guide for people dealing with code which has features that no longer
1185work after an upgrade of their perl.
a049258c 1186
2c8edc25 1187=head2 Changes to Existing Documentation
a049258c 1188
b10de59c
KW
1189We have attempted to update the documentation to reflect the changes
1190listed in this document. If you find any we have missed, send email to
bfe8fcbb 1191L<perlbug@perl.org|mailto:perlbug@perl.org>.
a049258c 1192
b10de59c
KW
1193Additionally all references to Usenet have been removed, and the
1194following selected changes have been made:
2c8edc25 1195
b10de59c 1196=head3 L<perlfunc>
a049258c 1197
b10de59c 1198=over 4
a049258c 1199
2c8edc25
S
1200=item *
1201
b10de59c
KW
1202Removed obsolete text about L<C<defined()>|perlfunc/defined>
1203on aggregates that should have been deleted earlier, when the feature
1204was removed.
2c8edc25
S
1205
1206=item *
1207
b10de59c
KW
1208Corrected documentation of L<C<eval()>|perlfunc/eval>,
1209and L<C<evalbytes()>|perlfunc/evalbytes>.
a049258c 1210
2c8edc25 1211=item *
a049258c 1212
b10de59c
KW
1213Clarified documentation of L<C<seek()>|perlfunc/seek>,
1214L<C<tell()>|perlfunc/tell> and L<C<sysseek()>|perlfunc/sysseek>
f9b6dffc 1215emphasizing that positions are in bytes and not characters.
b10de59c 1216L<[perl #128607]|https://rt.perl.org/Public/Bug/Display.html?id=128607>
2c8edc25
S
1217
1218=item *
1219
b10de59c
KW
1220Clarified documentation of L<C<sort()>|perlfunc/sort LIST> concerning
1221the variables C<$a> and C<$b>.
2c8edc25
S
1222
1223=item *
a049258c 1224
de7be789
KW
1225In L<C<split()>|perlfunc/split> noted that certain pattern modifiers are
1226legal, and added a caution about its use in Perls before v5.11,
a049258c 1227
2c8edc25 1228=item *
a049258c 1229
b10de59c
KW
1230Removed obsolete documentation of L<C<study()>|perlfunc/study>, noting
1231that it is now a no-op.
2c8edc25
S
1232
1233=item *
1234
b10de59c
KW
1235Noted that L<C<vec()>|perlfunc/vec> doesn't work well when the string
1236contains characters whose code points are above 255.
a049258c 1237
2c8edc25 1238=back
a049258c 1239
b10de59c 1240=head3 L<perlguts>
a049258c
S
1241
1242=over 4
1243
1244=item *
1245
b10de59c
KW
1246Added advice on
1247L<formatted printing of operands of C<Size_t> and C<SSize_t>|perlguts/Formatted Printing of Size_t and SSize_t>
a049258c
S
1248
1249=back
1250
b10de59c 1251=head3 L<perlhack>
2c8edc25
S
1252
1253=over 4
1254
1255=item *
1256
7964b3a0
KW
1257Clarify what editor tab stop rules to use, and note that we are
1258migrating away from using tabs, replacing them with sequences of SPACE
1259characters.
2c8edc25
S
1260
1261=back
a049258c 1262
b10de59c 1263=head3 L<perlhacktips>
a049258c
S
1264
1265=over 4
1266
1267=item *
1268
b10de59c 1269Give another reason to use C<cBOOL> to cast an expression to boolean.
2c8edc25
S
1270
1271=item *
1272
b10de59c
KW
1273Note that there are macros C<TRUE> and C<FALSE> available to express
1274boolean values.
a049258c 1275
2c8edc25 1276=back
a049258c 1277
2c8edc25 1278=head3 L<perlinterp>
a049258c
S
1279
1280=over 4
1281
1282=item *
1283
2c8edc25
S
1284L<perlinterp> has been expanded to give a more detailed example of how to
1285hunt around in the parser for how a given operator is handled.
a049258c
S
1286
1287=back
1288
2c8edc25 1289=head3 L<perllocale>
a049258c
S
1290
1291=over 4
1292
a6733086
S
1293=item *
1294
b10de59c
KW
1295Some locales aren't compatible with Perl. Note that these can cause
1296core dumps.
a049258c
S
1297
1298=back
1299
15a20477 1300=head3 L<perlmod>
2c8edc25
S
1301
1302=over 4
1303
1304=item *
1305
b10de59c 1306Various clarifications have been added.
2c8edc25
S
1307
1308=back
1309
1310=head3 L<perlmodlib>
1311
1312=over 4
1313
1314=item *
1315
b10de59c 1316Updated the site mirror list.
2c8edc25
S
1317
1318=back
1319
1320=head3 L<perlobj>
1321
1322=over 4
1323
1324=item *
1325
1326Added a section on calling methods using their fully qualified names.
1327
1328=item *
1329
0f032fe1 1330Do not discourage manual C<@ISA>.
2c8edc25
S
1331
1332=back
1333
1334=head3 L<perlootut>
1335
1336=over 4
1337
1338=item *
1339
2c8edc25
S
1340Mention C<Moo> more.
1341
1342=back
1343
1344=head3 L<perlop>
1345
1346=over 4
1347
1348=item *
1349
b072a8ef
KW
1350Note that white space must be used for quoting operators if the
1351delimiter is a word character (I<i.e.>, matches C<\w>).
1352
1353=item *
1354
1355Clarify that in regular expression patterns delimited by single quotes,
1356no variable interpolation is done.
2c8edc25
S
1357
1358=back
1359
1360=head3 L<perlre>
1361
1362=over 4
1363
1364=item *
1365
1c34b59a
KW
1366The first part was extensively rewritten to incorporate various basic
1367points, that in earlier versions were mentioned in sort of an appendix
1368on Version 8 regular expressions.
1369
0cbd1ffa
KW
1370=item *
1371
b10de59c
KW
1372Note that it is common to have the C</x> modifier and forget that this
1373means that C<"#"> has to be escaped.
2c8edc25
S
1374
1375=back
1376
b10de59c 1377=head3 L<perlretut>
2c8edc25
S
1378
1379=over 4
1380
1381=item *
1382
b10de59c 1383Add introductory material
2c8edc25
S
1384
1385=item *
1386
b10de59c
KW
1387Note that a metacharacter occurring in a context where it can't mean
1388that, silently loses its meta-ness and matches literally.
1389L<C<use re 'strict'>|re/'strict' mode> can catch some of these.
2c8edc25
S
1390
1391=back
1392
1393=head3 L<perlunicode>
1394
1395=over 4
1396
1397=item *
1398
b10de59c 1399Corrected the text about Unicode BYTE ORDER MARK handling.
2c8edc25
S
1400
1401=item *
1402
1403Updated the text to correspond with changes in Unicode UTS#18, concerning
1404regular expressions, and Perl compatibility with what it says.
1405
1406=back
1407
1408=head3 L<perlvar>
1409
1410=over 4
1411
1412=item *
1413
95b17558 1414Document C<@ISA>. Was documented other places, not not in L<perlvar>.
2c8edc25
S
1415
1416=back
1417
1418=head1 Diagnostics
1419
1420=head2 New Diagnostics
1421
1422=head3 New Errors
1423
1424=over 4
1425
1426=item *
1427
df48f9a4 1428Since C<"."> is now removed from C<@INC> by default, C<do> will now trigger
2c8edc25
S
1429a warning recommending to fix the C<do> statement:
1430
1431L<do "%s" failed, '.' is no longer in @INC|perldiag/do "%s" failed, '.' is no longer in @INC; did you mean do ".E<sol>%s"?>
1432
1433=item *
1434
1435Using the empty pattern (which re-executes the last successfully-matched
1436pattern) inside a code block in another regex, as in C</(?{ s!!new! })/>, has
95b17558 1437always previously yielded a segfault. It now produces an error:
4f73c567 1438L<Infinite recursion in regex|perldiag/"Infinite recursion in regex">.
2c8edc25
S
1439
1440=item *
1441
1442L<The experimental declared_refs feature is not enabled|perldiag/"The experimental declared_refs feature is not enabled">
1443
1444(F) To declare references to variables, as in C<my \%x>, you must first enable
1445the feature:
1446
1447 no warnings "experimental::declared_refs";
1448 use feature "declared_refs";
1449
473ac7a0
KW
1450See L</Declaring a reference to a variable>.
1451
2c8edc25
S
1452=item *
1453
1454L<Version control conflict marker|perldiag/"Version control conflict marker">
1455
e6abae1c 1456(F) The parser found a line starting with C<E<lt>E<lt>E<lt>E<lt>E<lt>E<lt>E<lt>>,
95b17558 1457C<E<gt>E<gt>E<gt>E<gt>E<gt>E<gt>E<gt>>, or C<=======>. These may be left by a
2c8edc25
S
1458version control system to mark conflicts after a failed merge operation.
1459
1460=item *
1461
1462L<%s: command not found|perldiag/"%s: command not found">
1463
1464(A) You've accidentally run your script through B<bash> or another shell
068a1201
KW
1465instead of Perl. Check the C<#!> line, or manually feed your script into
1466Perl yourself. The C<#!> line at the top of your file could look like:
2c8edc25
S
1467
1468 #!/usr/bin/perl
1469
1470=item *
1471
1472L<%s: command not found: %s|perldiag/"%s: command not found: %s">
1473
1474(A) You've accidentally run your script through B<zsh> or another shell
068a1201
KW
1475instead of Perl. Check the C<#!> line, or manually feed your script into
1476Perl yourself. The C<#!> line at the top of your file could look like:
2c8edc25
S
1477
1478 #!/usr/bin/perl
1479
1480=item *
1481
a6733086 1482L<Unescaped left brace in regex is illegal here|perldiag/Unescaped left brace in regex is illegal here in regex; marked by S<E<lt>-- HERE> in mE<sol>%sE<sol>>
2c8edc25 1483
d8362e1b
KW
1484Unescaped left braces are now illegal in some contexts in regular expression
1485patterns. In other contexts, they are still just deprecated; they will
1486be illegal in Perl 5.30.
2c8edc25
S
1487
1488=item *
1489
1490L<Bareword in require contains "%s"|perldiag/"Bareword in require contains "%s"">
1491
1492=item *
1493
1494L<Bareword in require maps to empty filename|perldiag/"Bareword in require maps to empty filename">
1495
1496=item *
1497
1498L<Bareword in require maps to disallowed filename "%s"|perldiag/"Bareword in require maps to disallowed filename "%s"">
1499
1500=item *
1501
1502L<Bareword in require must not start with a double-colon: "%s"|perldiag/"Bareword in require must not start with a double-colon: "%s"">
1503
1504=back
1505
1506=head3 New Warnings
1507
1508=over 4
1509
1510=item *
1511
4f73c567 1512L<Use of unassigned code point or non-standalone grapheme for a delimiter will be a fatal error starting in Perl 5.30|perldiag/"Use of unassigned code point or non-standalone grapheme for a delimiter will be a fatal error starting in Perl 5.30">
2c8edc25
S
1513
1514See L</Deprecations>
1515
1516=item *
1517
1518L<Declaring references is experimental|perldiag/"Declaring references is experimental">
1519
1520(S experimental::declared_refs) This warning is emitted if you use a reference
1521constructor on the right-hand side of C<my()>, C<state()>, C<our()>, or
1522C<local()>. Simply suppress the warning if you want to use the feature, but
1523know that in doing so you are taking the risk of using an experimental feature
1524which may change or be removed in a future Perl version:
1525
1526 no warnings "experimental::declared_refs";
1527 use feature "declared_refs";
1528 $fooref = my \$foo;
1529
473ac7a0
KW
1530See L</Declaring a reference to a variable>.
1531
2c8edc25
S
1532=item *
1533
4f73c567 1534L<C<${^ENCODING}> is no longer supported. Its use will be fatal in Perl 5.28|perldiag/"${^ENCODING} is no longer supported. Its use will be fatal in Perl 5.28">
2c8edc25 1535
0f275d26 1536The special variable C<${^ENCODING}>, formerly used to implement
53799a91 1537the C<encoding> pragma, is no longer supported as of Perl 5.26.
2c8edc25 1538
89853d76
DH
1539=item *
1540
df48f9a4 1541Since C<"."> is now removed from C<@INC> by default, C<do> will now trigger
89853d76
DH
1542a warning recommending to fix the C<do> statement:
1543
fc902710 1544L<do "%s" failed, '.' is no longer in @INC|perldiag/do "%s" failed, '.' is no longer in @INC; did you mean do ".E<sol>%s"?>
89853d76 1545
2c8edc25
S
1546=back
1547
1548=head2 Changes to Existing Diagnostics
1549
1550=over 4
1551
1552=item *
1553
1554When a C<require> fails, we now do not provide C<@INC> when the C<require>
1555is for a file instead of a module.
1556
1557=item *
1558
1559When C<@INC> is not scanned for a C<require> call, we no longer display
1560C<@INC> to avoid confusion.
1561
1562=item *
1563
02e0a8e8
KW
1564Details as to the exact problem have been added to the diagnostics that
1565occur when malformed UTF-8 is encountered when trying to convert to a
1566code point.
1567
1568=item *
1569
cf3a543f
KW
1570L<Attribute "locked" is deprecated, and will disappear in Perl 5.28
1571|perldiag/Attribute "locked" is deprecated, and will disappear in Perl 5.28>
2c8edc25
S
1572
1573=item *
1574
cf3a543f
KW
1575L<Attribute "unique" is deprecated, and will disappear in Perl 5.28
1576|perldiag/Attribute "unique" is deprecated, and will disappear in Perl 5.28>
2c8edc25
S
1577
1578=item *
1579
cf3a543f
KW
1580L<Constants from lexical variables potentially modified elsewhere are deprecated. This will not be allowed in Perl 5.32
1581|perldiag/Constants from lexical variables potentially modified elsewhere are deprecated. This will not be allowed in Perl 5.32>
2c8edc25
S
1582
1583=item *
1584
cf3a543f
KW
1585L<Deprecated use of C<my()> in false conditional. This will be a fatal error in Perl 5.30
1586|perldiag/Deprecated use of C<my()> in false conditional. This will be a fatal error in Perl 5.30>
2c8edc25
S
1587
1588=item *
1589
cf3a543f
KW
1590L<C<dump()> better written as C<CORE::dump()>. C<dump()> will no longer be available in Perl 5.30
1591|perldiag/C<dump()> better written as C<CORE::dump()>. C<dump()> will no longer be available in Perl 5.30>
2c8edc25
S
1592
1593=item *
1594
cf3a543f
KW
1595L<C<${^ENCODING}> is no longer supported. Its use will be fatal in Perl 5.28
1596|perldiag/C<${^ENCODING}> is no longer supported. Its use will be fatal in Perl 5.28>
2c8edc25
S
1597
1598=item *
1599
a3a9a3d2
KW
1600L<Experimental %s on scalar is now forbidden This message now is followed by more helpful text.
1601L<[perl #127976]|https://rt.perl.org/Public/Bug/Display.html?id=127976>
cf3a543f 1602|perldiag/Experimental %s on scalar is now forbidden>.
a3a9a3d2
KW
1603This message now is followed by more helpful text.
1604L<[perl #127976]|https://rt.perl.org/Public/Bug/Display.html?id=127976>
906e28fb
KW
1605
1606=item *
1607
cf3a543f
KW
1608L<C<File::Glob::glob()> will disappear in perl 5.30. Use C<File::Glob::bsd_glob()> instead.
1609|perldiag/C<File::Glob::glob()> will disappear in perl 5.30. Use C<File::Glob::bsd_glob()> instead.>
2c8edc25
S
1610
1611=item *
1612
cf3a543f
KW
1613L<%s() is deprecated on C<:utf8> handles. This will be a fatal error in Perl 5.30
1614|perldiag/%s() is deprecated on C<:utf8> handles. This will be a fatal error in Perl 5.30>.
d0d6ad19 1615"%s" is one of C<sysread>, C<recv>, C<syswrite>, or C<send>.
2c8edc25
S
1616
1617=item *
1618
cf3a543f
KW
1619L<C<$*> is no longer supported. Its use will be fatal in Perl 5.30
1620|perldiag/C<$*> is no longer supported. Its use will be fatal in Perl 5.30>
2c8edc25
S
1621
1622=item *
1623
cf3a543f
KW
1624L<Opening dirhandle %s also as a file. This will be a fatal error in Perl 5.28
1625|perldiag/Opening dirhandle %s also as a file. This will be a fatal error in Perl 5.28>
2c8edc25
S
1626
1627=item *
1628
cf3a543f
KW
1629L<Opening filehandle %s also as a directory. This will be a fatal error in Perl 5.28
1630|perldiag/Opening filehandle %s also as a directory. This will be a fatal error in Perl 5.28>
2c8edc25
S
1631
1632=item *
1633
cf3a543f
KW
1634L<Setting C<$/> to a reference to %s as a form of slurp is deprecated, treating as undef. This will be fatal in Perl 5.28
1635|perldiag/Setting C<$/> to a reference to %s as a form of slurp is deprecated, treating as undef. This will be fatal in Perl 5.28>
2c8edc25
S
1636
1637=item *
1638
cf3a543f
KW
1639L<Unescaped left brace in regex is deprecated here (and will be fatal in Perl 5.30), passed through in regex; marked by S<< E<lt>-- HERE >> in mE<sol>%sE<sol>
1640|perldiag/Unescaped left brace in regex is deprecated here (and will be fatal in Perl 5.30), passed through in regex; marked by S<< E<lt>-- HERE >> in m/%s/>
2c8edc25
S
1641
1642=item *
1643
cf3a543f
KW
1644L<Unknown charname '' is deprecated. Its use will be fatal in Perl 5.28
1645|perldiag/Unknown charname '' is deprecated. Its use will be fatal in Perl 5.28>
2c8edc25
S
1646
1647=item *
1648
cf3a543f
KW
1649L<Use of bare E<lt>E<lt> to mean E<lt>E<lt>"" is deprecated. Its use will be fatal in Perl 5.28
1650|perldiag/Use of bare E<lt>E<lt> to mean E<lt>E<lt>"" is deprecated. Its use will be fatal in Perl 5.28>
2c8edc25
S
1651
1652=item *
1653
cf3a543f
KW
1654L<Use of code point 0x%s is deprecated; the permissible max is 0x%s. This will be fatal in Perl 5.28
1655|perldiag/Use of code point 0x%s is deprecated; the permissible max is 0x%s. This will be fatal in Perl 5.28>
2c8edc25
S
1656
1657=item *
1658
cf3a543f
KW
1659L<Use of comma-less variable list is deprecated. Its use will be fatal in Perl 5.28
1660|perldiag/Use of comma-less variable list is deprecated. Its use will be fatal in Perl 5.28>
2c8edc25
S
1661
1662=item *
1663
cf3a543f
KW
1664L<Use of inherited C<AUTOLOAD> for non-method %s() is deprecated. This will be fatal in Perl 5.28
1665|perldiag/Use of inherited C<AUTOLOAD> for non-method %s() is deprecated. This will be fatal in Perl 5.28>
2c8edc25
S
1666
1667=item *
1668
cf3a543f
KW
1669L<Use of strings with code points over 0xFF as arguments to %s operator is deprecated. This will be a fatal error in Perl 5.28
1670|perldiag/Use of strings with code points over 0xFF as arguments to %s operator is deprecated. This will be a fatal error in Perl 5.28>
2c8edc25 1671
2c8edc25
S
1672=back
1673
1674=head1 Utility Changes
1675
1676=head2 F<c2ph> and F<pstruct>
1677
1678=over 4
1679
1680=item *
1681
1682These old utilities have long since superceded by L<h2xs>, and are
1683now gone from the distribution.
1684
1685=back
1686
1687=head2 F<Porting/pod_lib.pl>
1688
1689=over 4
1690
1691=item *
1692
1693Removed spurious executable bit.
1694
1695=item *
1696
fb5d4b1a 1697Account for the possibility of DOS file endings.
2c8edc25
S
1698
1699=back
1700
1701=head2 F<Porting/sync-with-cpan>
1702
1703=over 4
1704
1705=item *
1706
1707Many improvements
1708
1709=back
1710
1711=head2 F<perf/benchmarks>
1712
1713=over 4
1714
1715=item *
1716
1717Tidy file, rename some symbols.
1718
1719=back
1720
1721=head2 F<Porting/checkAUTHORS.pl>
1722
1723=over 4
1724
1725=item *
1726
0f275d26 1727Replace obscure character range with C<\w>.
2c8edc25
S
1728
1729=back
1730
1731=head2 F<t/porting/regen.t>
1732
1733=over 4
1734
1735=item *
1736
1737try to be more helpful when tests fail.
1738
1739=back
1740
1741=head2 F<utils/h2xs.PL>
1742
1743=over 4
1744
1745=item *
1746
1747Avoid infinite loop for enums.
1748
1749=back
1750
1751=head2 L<perlbug>
1752
1753=over 4
1754
1755=item *
1756
1757Long lines in the message body are now wrapped at 900 characters, to stay
1758well within the 1000-character limit imposed by SMTP mail transfer agents.
1759This is particularly likely to be important for the list of arguments to
1760C<Configure>, which can readily exceed the limit if, for example, it names
95b17558 1761several non-default installation paths. This change also adds the first unit
a3a9a3d2
KW
1762tests for perlbug.
1763L<[perl #128020]|https://rt.perl.org/Public/Bug/Display.html?id=128020>
2c8edc25
S
1764
1765=back
1766
1767=head1 Configuration and Compilation
1768
1769=over 4
1770
1771=item *
1772
89853d76 1773C<-Ddefault_inc_excludes_dot> has been turned on by default.
2c8edc25
S
1774
1775=item *
1776
a3a9a3d2
KW
1777The C<dtrace> build process has further changes
1778L<[perl #130108]|https://rt.perl.org/Public/Bug/Display.html?id=130108>:
2c8edc25
S
1779
1780=over
1781
1782=item *
1783
1784If the C<-xnolibs> is available, use that so a F<dtrace> perl can be
1785built within a FreeBSD jail.
1786
1787=item *
1788
1789On systems that build a dtrace object file (FreeBSD, Solaris and
1790SystemTap's dtrace emulation), copy the input objects to a separate
1791directory and process them there, and use those objects in the link,
1792since C<dtrace -G> also modifies these objects.
1793
1794=item *
1795
1796Add libelf to the build on FreeBSD 10.x, since dtrace adds references
1797to libelf symbols.
1798
1799=item *
1800
1801Generate a dummy dtrace_main.o if C<dtrace -G> fails to build it. A
1802default build on Solaris generates probes from the unused inline
1803functions, while they don't on FreeBSD, which causes C<dtrace -G> to
1804fail.
1805
1806=back
1807
2c8edc25
S
1808=item *
1809
0f032fe1
KW
1810You can now disable perl's use of the C<PERL_HASH_SEED> and
1811C<PERL_PERTURB_KEYS> environment variables by configuring perl with
2c8edc25
S
1812C<-Accflags=NO_PERL_HASH_ENV>.
1813
1814=item *
1815
0f032fe1 1816You can now disable perl's use of the C<PERL_HASH_SEED_DEBUG> environment
2c8edc25
S
1817variable by configuring perl with
1818C<-Accflags=-DNO_PERL_HASH_SEED_DEBUG>.
1819
1820=item *
1821
1822Zero out the alignment bytes when calculating the bytes for 80-bit C<NaN>
a3a9a3d2
KW
1823and C<Inf> to make builds more reproducible.
1824L<[perl #130133]|https://rt.perl.org/Public/Bug/Display.html?id=130133>
2c8edc25
S
1825
1826=item *
1827
fb5d4b1a 1828Since v5.18 for testing purposes, we have included support for
2c8edc25 1829building perl with a variety of non-standard, and non-recommended
95b17558
KW
1830hash functions. Since we do not recommend the use of these functions
1831we have removed them and their corresponding build options. Specifically
2c8edc25
S
1832this includes the following build options:
1833
1834 PERL_HASH_FUNC_SDBM
1835 PERL_HASH_FUNC_DJB2
1836 PERL_HASH_FUNC_SUPERFAST
1837 PERL_HASH_FUNC_MURMUR3
1838 PERL_HASH_FUNC_ONE_AT_A_TIME
1839 PERL_HASH_FUNC_ONE_AT_A_TIME_OLD
1840 PERL_HASH_FUNC_MURMUR_HASH_64A
1841 PERL_HASH_FUNC_MURMUR_HASH_64B
1842
1843=item *
1844
1845Remove "Warning: perl appears in your path"
1846
1847This install warning is more or less obsolete, since most platforms already
0f032fe1 1848B<will> have a F</usr/bin/perl> or similar provided by the OS.
2c8edc25
S
1849
1850=item *
1851
0f032fe1 1852Reduce verbosity of C<make install.man>
2c8edc25
S
1853
1854Previously, two progress messages were emitted for each manpage: one by
1855installman itself, and one by the function in install_lib.pl that it calls to
95b17558 1856actually install the file. Disabling the second of those in each case saves
2c8edc25
S
1857over 750 lines of unhelpful output.
1858
1859=item *
1860
a3a9a3d2
KW
1861Cleanup for C<clang -Weverything> support.
1862L<[perl #129961]|https://rt.perl.org/Public/Bug/Display.html?id=129961>
2c8edc25
S
1863
1864=item *
1865
1866Configure: signbit scan was assuming too much, stop assuming negative 0.
1867
1868=item *
1869
1870Various compiler warnings have been silenced.
1871
1872=item *
1873
1874Several smaller changes have been made to remove impediments to compiling under
1875C++11.
1876
1877=item *
1878
1879Builds using C<USE_PAD_RESET> now work again; this configuration had
1880bit-rotted.
1881
1882=item *
1883
1884A probe for C<gai_strerror> was added to F<Configure> that checks if the
0f032fe1
KW
1885the C<gai_strerror()> routine is available and can be used to
1886translate error codes returned by C<getaddrinfo()> into human
2c8edc25
S
1887readable strings.
1888
1889=item *
1890
0f032fe1 1891F<Configure> now aborts if both C<-Duselongdouble> and C<-Dusequadmath> are
2c8edc25
S
1892requested.
1893L<[perl #126203]|https://rt.perl.org/Public/Bug/Display.html?id=126203>
1894
1895=item *
1896
0f032fe1 1897Fixed a bug in which F<Configure> could append C<-quadmath> to the archname even
2c8edc25
S
1898if it was already present.
1899L<[perl #128538]|https://rt.perl.org/Public/Bug/Display.html?id=128538>
1900
1901=item *
1902
0f032fe1
KW
1903Clang builds with C<-DPERL_GLOBAL_STRUCT> or
1904C<-DPERL_GLOBAL_STRUCT_PRIVATE> have
2c8edc25
S
1905been fixed (by disabling Thread Safety Analysis for these configurations).
1906
1907=item *
1908
1909F<make_ext.pl> no longer updates a module's F<pm_to_blib> file when no
1910files require updates. This could cause dependencies, F<perlmain.c>
a3a9a3d2
KW
1911in particular, to be rebuilt unnecessarily.
1912L<[perl #126710]|https://rt.perl.org/Public/Bug/Display.html?id=126710>
2c8edc25
S
1913
1914=item *
1915
1916The output of C<perl -V> has been reformatted so that each configuration
1917and compile-time option is now listed one per line, to improve
1918readability.
1919
1920=item *
1921
1922C<Configure> now builds C<miniperl> and C<generate_uudmap> if you
1923invoke it with C<-Dusecrosscompiler> but not C<-Dtargethost=somehost>.
1924This means you can supply your target platform C<config.sh>, generate
a3a9a3d2
KW
1925the headers and proceed to build your cross-target perl.
1926L<[perl #127234]|https://rt.perl.org/Public/Bug/Display.html?id=127234>
2c8edc25
S
1927
1928=item *
1929
1930Builds with C<-Accflags=-DPERL_TRACE_OPS> now only dump the operator
1931counts when the environment variable C<PERL_TRACE_OPS> to be set to a
1932non-zero integer. This allows C<make test> to pass on such a build.
1933
1934=item *
1935
1936When building with GCC 6 and link-time optimization (the C<-flto> option to
1937C<gcc>), C<Configure> was treating all probed symbols as present on the
95b17558 1938system, regardless of whether they actually exist. This has been fixed.
a3a9a3d2 1939L<[perl #128131]|https://rt.perl.org/Public/Bug/Display.html?id=128131>
2c8edc25
S
1940
1941=item *
1942
1943The F<t/test.pl> library is used for internal testing of Perl itself, and
95b17558 1944also copied by several CPAN modules. Some of those modules must work on
2c8edc25 1945older versions of Perl, so F<t/test.pl> must in turn avoid newer Perl
95b17558 1946features. Compatibility with Perl 5.8 was inadvertently removed some time
a3a9a3d2
KW
1947ago; it has now been restored.
1948L<[perl #128052]|https://rt.perl.org/Public/Bug/Display.html?id=128052>
2c8edc25
S
1949
1950=item *
1951
1952The build process no longer emits an extra blank line before building each
1953"simple" extension (those with only F<*.pm> and F<*.pod> files).
1954
1955=back
1956
1957=head1 Testing
1958
dd84ba97
KW
1959Tests were added and changed to reflect the other additions and changes
1960in this release. In addition, these substantive changes were made:
1961
2c8edc25
S
1962=over 4
1963
1964=item *
1965
dd84ba97
KW
1966A new test script, F<comp/parser_run.t>, has been added to test
1967reads through invalid pointers.
2c8edc25
S
1968
1969=item *
1970
1971Tests for locales were erroneously using locales incompatible with Perl.
1972
1973=item *
1974
1975Some parts of the test suite that try to exhaustively test edge cases in the
1976regex implementation have been restricted to running for a maximum of five
95b17558 1977minutes. On slow systems they could otherwise take several hours, without
2c8edc25
S
1978significantly improving our understanding of the correctness of the code
1979under test.
1980
1981In addition, some of those test cases have been split into more files, to
1982allow them to be run in parallel on suitable systems.
1983
1984=item *
1985
1986A new internal facility allows analysing the time taken by the individual
1987tests in Perl's own test suite; see F<Porting/harness-timer-report.pl>.
1988
1989=item *
1990
1991F<t/re/regexp_nonull.t> has been added to test that the regular expression
1992engine can handle scalars that do not have a null byte just past the end of
1993the string.
1994
1995=item *
1996
0ebc1fcf
KW
1997A new test script, F<t/op/decl-refs.t>, has been added to test the new feature
1998L</Declaring a reference to a variable>.
2c8edc25
S
1999
2000=item *
2001
dd84ba97
KW
2002A new test script, F<t/re/keep_tabs.t> has been added to contain tests
2003where C<\t> characters should not be expanded into spaces.
2004
2005=item *
2006
2c8edc25
S
2007A new test script, F<t/re/anyof.t>, has been added to test that the ANYOF nodes
2008generated by bracketed character classes are as expected.
2009
2010=item *
2011
dd84ba97
KW
2012There is now more extensive testing of the Unicode-related API macros
2013and functions.
2014
2015=item *
2016
2017Several of the longer running API test files have been split into
2018multiple test files so that they can be run in parallel.
2019
2020=item *
2021
2c8edc25 2022F<t/harness> now tries really hard not to run tests outside of the Perl
a3a9a3d2
KW
2023source tree.
2024L<[perl #124050]|https://rt.perl.org/Public/Bug/Display.html?id=124050>
2c8edc25
S
2025
2026=back
2027
2028=head1 Platform Support
2029
2030=head2 New Platforms
2031
2032=over 4
2033
2034=item NetBSD/VAX
2035
2036Perl now compiles under NetBSD on VAX machines. However, it's not
2037possible for that platform to implement floating-point infinities and
2038NaNs compatibly with most modern systems, which implement the IEEE-754
2039floating point standard. The hexadecimal floating point (C<0x...p[+-]n>
2040literals, C<printf %a>) is not implemented, either.
2041The C<make test> passes 98% of tests.
2042
2043=over 4
2044
2045=item *
2046
2047Test fixes and minor updates.
2048
2049=item *
2050
2051Account for lack of C<inf>, C<nan>, and C<-0.0> support.
2052
2053=back
2054
2055=back
2056
2057=head2 Platform-Specific Notes
2058
2059=over 4
2060
2061=item Darwin
2062
0f032fe1
KW
2063don't treat C<-Dprefix=/usr> as special, instead require an extra option
2064C<-Ddarwin_distribution> to produce the same results.
2c8edc25
S
2065
2066=item POSIX
2067
2068Finish removing POSIX deprecated functions.
2069
2070=item OS X
2071
0f032fe1
KW
2072OS X El Capitan doesn't implement the C<clock_gettime()> or
2073C<clock_getres()> APIs; emulate them as necessary.
2c8edc25
S
2074
2075=item macOS
2076
0f032fe1 2077Deprecated C<syscall(2)> on macOS 10.12.
2c8edc25
S
2078
2079=item EBCDIC
2080
2081Several tests have been updated to work (or be skipped) on EBCDIC platforms.
2082
2083=item HP-UX
2084
2085L<Net::Ping> UDP test is skipped on HP-UX.
2086
2087=item Hurd
2088
2089The hints for Hurd have been improved enabling malloc wrap and reporting the
2090GNU libc used (previously it was an empty string when reported).
2091
2092=item VAX
2093
29ce4d71 2094VAX floating point formats are now supported on NetBSD.
2c8edc25
S
2095
2096=item VMS
2097
2098=over 4
2099
2100=item *
2101
2102The path separator for the C<PERL5LIB> and C<PERLLIB> environment entries is
df48f9a4
KW
2103now a colon (C<":">) when running under a Unix shell. There is no change when
2104running under DCL (it's still C<"|">).
2c8edc25
S
2105
2106=item *
2107
29ce4d71
CB
2108C<configure.com> now recognizes the VSI-branded C compiler and no longer
2109recognizes the "DEC"-branded C compiler (as there hasn't been such a thing for
211015 or more years).
2c8edc25
S
2111
2112=back
2113
2114=item Windows
2115
2116=over 4
2117
2118=item *
2119
2120Support for compiling perl on Windows using Microsoft Visual Studio 2015
2121(containing Visual C++ 14.0) has been added.
2122
2123This version of VC++ includes a completely rewritten C run-time library, some
0f032fe1
KW
2124of the changes in which mean that work done to resolve a socket
2125C<close()> bug in
2c8edc25
S
2126perl #120091 and perl #118059 is not workable in its current state with this
2127version of VC++. Therefore, we have effectively reverted that bug fix for
2128VS2015 onwards on the basis that being able to build with VS2015 onwards is
2129more important than keeping the bug fix. We may revisit this in the future to
2130attempt to fix the bug again in a way that is compatible with VS2015.
2131
2132These changes do not affect compilation with GCC or with Visual Studio versions
fce64130 2133up to and including VS2013, I<i.e.>, the bug fix is retained (unchanged) for those
2c8edc25
S
2134compilers.
2135
2136Note that you may experience compatibility problems if you mix a perl built
2137with GCC or VS E<lt>= VS2013 with XS modules built with VS2015, or if you mix a
2138perl built with VS2015 with XS modules built with GCC or VS E<lt>= VS2013.
2139Some incompatibility may arise because of the bug fix that has been reverted
2140for VS2015 builds of perl, but there may well be incompatibility anyway because
fce64130 2141of the rewritten CRT in VS2015 (I<e.g.>, see discussion at
bdd37d82 2142L<http://stackoverflow.com/questions/30412951>).
2c8edc25
S
2143
2144=back
2145
2146=item Win32
2147
2148=over 4
2149
2150=item *
2151
95b17558 2152Tweaks for Win32 VC vs GCC detection makefile code. This fixes issue that CCHOME
2c8edc25 2153depends on CCTYPE, which in auto detect mode is set after CCHOME, so CCHOME uses
95b17558 2154the uninit CCTYPE var. Also fix else vs .ELSE in makefile.mk
2c8edc25
S
2155
2156=item *
2157
2158fp definitions have been updated.
2159
2160=back
2161
2c8edc25
S
2162=item Linux
2163
2164Drop support for Linux a.out Linux has used ELF for over twenty years.
2165
2166=item OpenBSD 6
2167
2168OpenBSD 6 still does not support returning pid, gid or uid with SA_SIGINFO.
2169Make sure this is accounted for.
2170
2171=item FreeBSD
2172
0f032fe1 2173F<t/uni/overload.t>: Skip hanging test on FreeBSD.
2c8edc25
S
2174
2175=back
2176
2177=head1 Internal Changes
2178
2179=over 4
2180
2181=item *
2182
0ebc1fcf
KW
2183A new API function L<C<sv_setpv_bufsize()>|perlapi/sv_setpv_bufsize>
2184allows simultaneously setting the
c2ef64b1
DM
2185length and allocated size of the buffer in an C<SV>, growing the buffer if
2186necessary.
2c8edc25
S
2187
2188=item *
2189
0ebc1fcf
KW
2190A new API macro L<C<SvPVCLEAR()>|perlapi/SvPVCLEAR> sets its C<SV>
2191argument to an empty string,
c2ef64b1 2192like Perl-space C<$x = ''>, but with several optimisations.
2c8edc25
S
2193
2194=item *
2195
c11f9206 2196Several new macros and functions for dealing with Unicode and
fb5d4b1a
KW
2197UTF-8-encoded strings have been added to the API, as well as some
2198changes in
c11f9206
DM
2199functionality of existing functions (see L<perlapi/Unicode Support> for
2200more details):
2201
2202=over
2203
2204=item *
2205
0ebc1fcf
KW
2206New versions of the API macros like C<isALPHA_utf8> and C<toLOWER_utf8>
2207have been added, each with the suffix C<_safe>, like
2208L<C<isSPACE_utf8_safe>|perlapi/isSPACE>. These take an extra
2209parameter, giving an upper
2210limit of how far into the string it is safe to read. Using the old
2211versions could cause attempts to read beyond the end of the input buffer
2212if the UTF-8 is not well-formed, and their use now raises a deprecation
2213warning. Details are at L<perlapi/Character classification>.
2c8edc25
S
2214
2215=item *
2216
0ebc1fcf
KW
2217Macros like L<C<isALPHA_utf8>|perlapi/isALPHA> and
2218L<C<toLOWER_utf8>|perlapi/toLOWER_utf8> now die if they detect
ac6c7175
KW
2219that their input UTF-8 is malformed. A deprecation warning had been
2220issued since Perl 5.18.
2c8edc25
S
2221
2222=item *
2223
c11f9206
DM
2224Several new macros for analysing the validity of utf8 sequences. These
2225are:
2226
bfe8fcbb
KW
2227L<C<UTF8_GOT_ABOVE_31_BIT>|perlapi/UTF8_GOT_ABOVE_31_BIT>
2228L<C<UTF8_GOT_CONTINUATION>|perlapi/UTF8_GOT_CONTINUATION>
2229L<C<UTF8_GOT_EMPTY>|perlapi/UTF8_GOT_EMPTY>
2230L<C<UTF8_GOT_LONG>|perlapi/UTF8_GOT_LONG>
2231L<C<UTF8_GOT_NONCHAR>|perlapi/UTF8_GOT_NONCHAR>
2232L<C<UTF8_GOT_NON_CONTINUATION>|perlapi/UTF8_GOT_NON_CONTINUATION>
2233L<C<UTF8_GOT_OVERFLOW>|perlapi/UTF8_GOT_OVERFLOW>
2234L<C<UTF8_GOT_SHORT>|perlapi/UTF8_GOT_SHORT>
2235L<C<UTF8_GOT_SUPER>|perlapi/UTF8_GOT_SUPER>
2236L<C<UTF8_GOT_SURROGATE>|perlapi/UTF8_GOT_SURROGATE>
2237L<C<UTF8_IS_INVARIANT>|perlapi/UTF8_IS_INVARIANT>
2238L<C<UTF8_IS_NONCHAR>|perlapi/UTF8_IS_NONCHAR>
2239L<C<UTF8_IS_SUPER>|perlapi/UTF8_IS_SUPER>
2240L<C<UTF8_IS_SURROGATE>|perlapi/UTF8_IS_SURROGATE>
2241L<C<UVCHR_IS_INVARIANT>|perlapi/UVCHR_IS_INVARIANT>
2242L<C<isUTF8_CHAR_flags>|perlapi/isUTF8_CHAR_flags>
2243L<C<isSTRICT_UTF8_CHAR>|perlapi/isSTRICT_UTF8_CHAR>
2244L<C<isC9_STRICT_UTF8_CHAR>|perlapi/isC9_STRICT_UTF8_CHAR>
2c8edc25
S
2245
2246=item *
2247
0f032fe1 2248Functions that are all extensions of the C<is_utf8_string_I<*>()> functions,
c11f9206
DM
2249that apply various restrictions to the UTF-8 recognized as valid:
2250
bfe8fcbb
KW
2251L<C<is_strict_utf8_string>|perlapi/is_strict_utf8_string>,
2252L<C<is_strict_utf8_string_loc>|perlapi/is_strict_utf8_string_loc>,
2253L<C<is_strict_utf8_string_loclen>|perlapi/is_strict_utf8_string_loclen>,
c11f9206 2254
bfe8fcbb
KW
2255L<C<is_c9strict_utf8_string>|perlapi/is_c9strict_utf8_string>,
2256L<C<is_c9strict_utf8_string_loc>|perlapi/is_c9strict_utf8_string_loc>,
2257L<C<is_c9strict_utf8_string_loclen>|perlapi/is_c9strict_utf8_string_loclen>,
c11f9206 2258
bfe8fcbb
KW
2259L<C<is_utf8_string_flags>|perlapi/is_utf8_string_flags>,
2260L<C<is_utf8_string_loc_flags>|perlapi/is_utf8_string_loc_flags>,
2261L<C<is_utf8_string_loclen_flags>|perlapi/is_utf8_string_loclen_flags>,
c11f9206 2262
bfe8fcbb
KW
2263L<C<is_utf8_fixed_width_buf_flags>|perlapi/is_utf8_fixed_width_buf_flags>,
2264L<C<is_utf8_fixed_width_buf_loc_flags>|perlapi/is_utf8_fixed_width_buf_loc_flags>,
2265L<C<is_utf8_fixed_width_buf_loclen_flags>|perlapi/is_utf8_fixed_width_buf_loclen_flags>.
c11f9206 2266
bfe8fcbb
KW
2267L<C<is_utf8_invariant_string>|perlapi/is_utf8_invariant_string>.
2268L<C<is_utf8_valid_partial_char>|perlapi/is_utf8_valid_partial_char>.
2269L<C<is_utf8_valid_partial_char_flags>|perlapi/is_utf8_valid_partial_char_flags>.
2c8edc25
S
2270
2271=item *
2272
bfe8fcbb
KW
2273The functions L<C<utf8n_to_uvchr>|perlapi/utf8n_to_uvchr> and its
2274derivatives have had several changes of behaviour.
c11f9206
DM
2275
2276Calling them, while passing a string length of 0 is now asserted against
2277in DEBUGGING builds, and otherwise returns the Unicode REPLACEMENT
2278CHARACTER. If you have nothing to decode, you shouldn't call the decode
2279function.
2280
2281They now return the Unicode REPLACEMENT CHARACTER if called with UTF-8
2282that has the overlong malformation, and that malformation is allowed by
2283the input parameters. This malformation is where the UTF-8 looks valid
2284syntactically, but there is a shorter sequence that yields the same code
2285point. This has been forbidden since Unicode version 3.1.
2286
2287They now accept an input
2c8edc25
S
2288flag to allow the overflow malformation. This malformation is when the
2289UTF-8 may be syntactically valid, but the code point it represents is
2290not capable of being represented in the word length on the platform.
2291What "allowed" means in this case is that the function doesn't return an
fb5d4b1a
KW
2292error, and it advances the parse pointer to beyond the UTF-8 in
2293question, but it returns the Unicode REPLACEMENT CHARACTER as the value
2294of the code point (since the real value is not representable).
2c8edc25 2295
55b0afa5
KW
2296They no longer abandon searching for other malformations when the first
2297one is encountered. A call to one of these functions thus can generate
2298multiple diagnostics, instead of just one.
2c8edc25
S
2299
2300=item *
2301
0ebc1fcf
KW
2302L<C<valid_utf8_to_uvchr()>|perlapi/valid_utf8_to_uvchr> has been added
2303to the API (although it was
c11f9206 2304present in core earlier). Like C<utf8_to_uvchr_buf()>, but assumes that
fb5d4b1a 2305the next character is well-formed. Use with caution.
c11f9206
DM
2306
2307=item *
2308
bfe8fcbb
KW
2309A new function, L<C<utf8n_to_uvchr_error>|perlapi/utf8n_to_uvchr_error>,
2310has been added for
2c8edc25
S
2311use by modules that need to know the details of UTF-8 malformations
2312beyond pass/fail. Previously, the only ways to know why a sequence was
2313ill-formed was to capture and parse the generated diagnostics, or to do
2314your own analysis.
2315
2316=item *
2317
0ebc1fcf
KW
2318There is now a safer version of utf8_hop(), called
2319L<C<utf8_hop_safe()>|perlapi/utf8_hop_safe>.
c11f9206
DM
2320Unlike utf8_hop(), utf8_hop_safe() won't navigate before the beginning or
2321after the end of the supplied buffer.
2c8edc25
S
2322
2323=item *
2324
0ebc1fcf
KW
2325Two new functions, L<C<utf8_hop_forward()>|perlapi/utf8_hop_forward> and
2326L<C<utf8_hop_back()>|perlapi/utf8_hop_back> are
c11f9206
DM
2327similar to C<utf8_hop_safe()> but are for when you know which direction
2328you wish to travel.
2c8edc25
S
2329
2330=item *
2331
c11f9206
DM
2332Two new macros which return useful utf8 byte sequences:
2333
bfe8fcbb
KW
2334L<C<BOM_UTF8>|perlapi/BOM_UTF8>
2335L<C<REPLACEMENT_CHARACTER_UTF8>|perlapi/REPLACEMENT_CHARACTER_UTF8>
c11f9206
DM
2336
2337=back
c2ef64b1
DM
2338
2339=item *
2340
2341Perl is now built with the C<PERL_OP_PARENT> compiler define enabled by
2342default. To disable it, use the C<PERL_NO_OP_PARENT> compiler define.
2343This flag alters how the C<op_sibling> field is used in C<OP> structures,
2344and has been available optionally since perl 5.22.
2345
2346See L<perl5220delta/"Internal Changes"> for more details of what this
2347build option does.
2348
2349=item *
2350
2351Three new ops, C<OP_ARGELEM>, C<OP_ARGDEFELEM> and C<OP_ARGCHECK> have
2352been added. These are intended principally to implement the individual
2353elements of a subroutine signature, plus any overall checking required.
2354
2355=item *
2356
0ebc1fcf
KW
2357The L<C<op_class()>|perlapi/op_class> API function has been added. This
2358is like the existing
c2ef64b1
DM
2359C<OP_CLASS()> macro, but can more accurately determine what struct an op
2360has been allocated as. For example C<OP_CLASS()> might return
2361C<OA_BASEOP_OR_UNOP> indicating that ops of this type are usually
2362allocated as an C<OP> or C<UNOP>; while C<op_class()> will return
2363C<OPclass_BASEOP> or C<OPclass_UNOP> as appropriate.
2c8edc25
S
2364
2365=item *
2366
2367All parts of the internals now agree that the C<sassign> op is a C<BINOP>;
2368previously it was listed as a C<BASEOP> in F<regen/opcodes>, which meant
2369that several parts of the internals had to be special-cased to accommodate
95b17558 2370it. This oddity's original motivation was to handle code like C<$x ||= 1>;
2c8edc25
S
2371that is now handled in a simpler way.
2372
2373=item *
2374
0ebc1fcf
KW
2375The output format of the L<C<op_dump()>|perlapi/op_dump> function (as
2376used by C<perl -Dx>)
c2ef64b1
DM
2377has changed: it now displays an "ASCII-art" tree structure, and shows more
2378low-level details about each op, such as its address and class.
2c8edc25
S
2379
2380=item *
2381
c2ef64b1
DM
2382The C<PADOFFSET> type has changed from being unsigned to signed, and
2383several pad-related variables such as C<PL_padix> have changed from being
2384of type C<I32> to type C<PADOFFSET>.
2c8edc25
S
2385
2386=item *
2387
c2ef64b1
DM
2388The C<DEBUGGING>-mode output for regex compilation and execution has been
2389enhanced.
2c8edc25
S
2390
2391=item *
2392
74ca8c9e
DM
2393Several obscure SV flags have been eliminated, sometimes along with the
2394macros which manipulate them: C<SVpbm_VALID>, C<SVpbm_TAIL>, C<SvTAIL_on>,
2395C<SvTAIL_off>, C<SVrepl_EVAL>, C<SvEVALED>
2c8edc25
S
2396
2397=item *
2398
74ca8c9e
DM
2399An OP op_private flag has been eliminated: C<OPpRUNTIME>. This used to
2400often get set on C<PMOP>s, but had become meaningless over time.
2c8edc25
S
2401
2402=back
2403
2404=head1 Selected Bug Fixes
2405
2406=over 4
2407
2408=item *
2409
5573eafe 2410Perl no longer panics when switching into some locales on machines with
a3a9a3d2
KW
2411buggy C<strxfrm()> implementations in their libc.
2412L<[perl #121734]|https://rt.perl.org/Public/Bug/Display.html?id=121734>
5573eafe
DM
2413
2414=item *
2415
2c8edc25
S
2416C< $-{$name} > would leak an C<AV> on each access if the regular
2417expression had no named captures. The same applies to access to any
2418hash tied with L<Tie::Hash::NamedCapture> and C<< all =E<gt> 1 >>. [perl
2419#130822]
2420
2421=item *
2422
2423Attempting to use the deprecated variable C<$#> as the object in an
2424indirect object method call could cause a heap use after free or
a3a9a3d2
KW
2425buffer overflow.
2426L<[perl #129274]|https://rt.perl.org/Public/Bug/Display.html?id=129274>
2c8edc25
S
2427
2428=item *
2429
2430When checking for an indirect object method call in some rare cases
2431the parser could reallocate the line buffer but then continue to use
a3a9a3d2
KW
2432pointers to the old buffer.
2433L<[perl #129190]|https://rt.perl.org/Public/Bug/Display.html?id=129190>
2c8edc25
S
2434
2435=item *
2436
0f032fe1
KW
2437Supplying a glob as the format argument to
2438L<C<formline>|perlfunc/formline> would
a3a9a3d2
KW
2439cause an assertion failure.
2440L<[perl #130722]|https://rt.perl.org/Public/Bug/Display.html?id=130722>
2c8edc25
S
2441
2442=item *
2443
2444Code like C< $value1 =~ qr/.../ ~~ $value2 > would have the match
0f032fe1 2445converted into a C<qr//> operator, leaving extra elements on the stack to
a3a9a3d2
KW
2446confuse any surrounding expression.
2447L<[perl #130705]|https://rt.perl.org/Public/Bug/Display.html?id=130705>
2c8edc25
S
2448
2449=item *
2450
d3972b39 2451Since v5.24 in some obscure cases, a regex which included code blocks
0f032fe1 2452from multiple sources (I<e.g.>, via embedded via C<qr//> objects) could end up
a3a9a3d2
KW
2453with the wrong current pad and crash or give weird results.
2454L<[perl #129881]|https://rt.perl.org/Public/Bug/Display.html?id=129881>
2c8edc25
S
2455
2456=item *
2457
2458Occasionally C<local()>s in a code block within a patterns weren't being
2459undone when the pattern matching backtracked over the code block.
a3a9a3d2 2460L<[perl #126697]|https://rt.perl.org/Public/Bug/Display.html?id=126697>
2c8edc25
S
2461
2462=item *
2463
2464Using C<substr()> to modify a magic variable could access freed memory
a3a9a3d2
KW
2465in some cases.
2466L<[perl #129340]|https://rt.perl.org/Public/Bug/Display.html?id=129340>
2c8edc25
S
2467
2468=item *
2469
2c8edc25 2470Under C<use utf8>, the entire Perl program is now checked that the UTF-8
a3a9a3d2
KW
2471is wellformed.
2472L<[perl #126310]|https://rt.perl.org/Public/Bug/Display.html?id=126310>.
2c8edc25
S
2473
2474=item *
2475
df48f9a4 2476The range operator C<".."> on strings now handles its arguments correctly when in
2c8edc25 2477the scope of the L<< C<unicode_strings>|feature/"The 'unicode_strings' feature" >>
95b17558 2478feature. The previous behaviour was sufficiently unexpected that we believe no
2c8edc25
S
2479correct program could have made use of it.
2480
2481=item *
2482
0f032fe1 2483The C<split> operator did not ensure enough space was allocated for
2c8edc25
S
2484its return value in scalar context. It could then write a single
2485pointer immediately beyond the end of the memory block allocated for
a3a9a3d2
KW
2486the stack.
2487L<[perl #130262]|https://rt.perl.org/Public/Bug/Display.html?id=130262>
2c8edc25
S
2488
2489=item *
2490
df48f9a4 2491Using a large code point with the C<"W"> pack template character with
2c8edc25
S
2492the current output position aligned at just the right point could
2493cause a write a single zero byte immediately beyond the end of an
a3a9a3d2
KW
2494allocated buffer.
2495L<[perl #129149]|https://rt.perl.org/Public/Bug/Display.html?id=129149>
2c8edc25
S
2496
2497=item *
2498
2499Supplying the form picture argument as part of the form argument list
2500where the picture specifies modifying the argument could cause an
a3a9a3d2
KW
2501access to the new freed compiled form.
2502L<[perl #129125]|https://rt.perl.org/Public/Bug/Display.html?id=129125>
2c8edc25
S
2503
2504=item *
2505
2506Fix a problem with sort's build-in compare, where it would not sort
a3a9a3d2
KW
2507correctly with 64-bit integers, and non-long doubles.
2508L<[perl #130335]|https://rt.perl.org/Public/Bug/Display.html?id=130335>
2c8edc25
S
2509
2510=item *
2511
0ebc1fcf 2512Fix issues with C</(?{ ... E<lt>E<lt>EOF })/> that broke
a3a9a3d2
KW
2513L<Method::Signatures>.
2514L<[perl #130398]|https://rt.perl.org/Public/Bug/Display.html?id=130398>
2c8edc25
S
2515
2516=item *
2517
a3a9a3d2
KW
2518Prevent tests from getting hung up on 'NonStop' option.
2519L<[perl #130445]|https://rt.perl.org/Public/Bug/Display.html?id=130445>
2c8edc25
S
2520
2521=item *
2522
2523Fixed an assertion failure with C<chop> and C<chomp>, which
a3a9a3d2
KW
2524could be triggered by C<chop(@x =~ tr/1/1/)>.
2525L<[perl #130198]|https://rt.perl.org/Public/Bug/Display.html?id=130198>.
2c8edc25
S
2526
2527=item *
2528
fb5d4b1a
KW
2529Fixed a comment skipping error in patterns under C</x>; it could stop
2530skipping a byte early, which could be in the middle of a UTF-8
a3a9a3d2
KW
2531character.
2532L<[perl #130495]|https://rt.perl.org/Public/Bug/Display.html?id=130495>.
2c8edc25
S
2533
2534=item *
2535
a3a9a3d2
KW
2536F<perldb> now ignores F</dev/tty> on non-Unix systems.
2537L<[perl #113960]|https://rt.perl.org/Public/Bug/Display.html?id=113960>;
2c8edc25
S
2538
2539=item *
2540
a3a9a3d2
KW
2541Fix assertion failure for C<{}-E<gt>$x> when C<$x> isn't defined.
2542L<[perl #130496]|https://rt.perl.org/Public/Bug/Display.html?id=130496>.
2c8edc25
S
2543
2544=item *
2545
a3a9a3d2
KW
2546DragonFly BSD now has support for C<setproctitle()>.
2547L<[perl #130068]|https://rt.perl.org/Public/Bug/Display.html?id=130068>.
2c8edc25
S
2548
2549=item *
2550
fb5d4b1a 2551Fix an assertion error which could be triggered when a lookahead string
a3a9a3d2
KW
2552in patterns exceeded a minimum length.
2553L<[perl #130522]|https://rt.perl.org/Public/Bug/Display.html?id=130522>.
2c8edc25
S
2554
2555=item *
2556
a3a9a3d2
KW
2557Only warn once per literal about a misplaced C<"_">.
2558L<[perl #70878]|https://rt.perl.org/Public/Bug/Display.html?id=70878>.
2c8edc25
S
2559
2560=item *
2561
a3a9a3d2
KW
2562Ensure range-start is set after error in C<tr///>.
2563L<[perl #129342]|https://rt.perl.org/Public/Bug/Display.html?id=129342>.
2c8edc25
S
2564
2565=item *
2566
2567Don't read past start of string for unmatched backref; otherwise,
a3a9a3d2
KW
2568we may have heap buffer overflow.
2569L<[perl #129377]|https://rt.perl.org/Public/Bug/Display.html?id=129377>.
2c8edc25
S
2570
2571=item *
2572
2c8edc25 2573C<use re 'strict'> is supposed to warn if you use a range whose start
95b17558 2574and end digit aren't from the same group of 10. It didn't do that
2c8edc25
S
2575for five groups of mathematical digits starting at U+1D7E.
2576
2577=item *
2578
fce64130 2579A sub containing a "forward" declaration with the same name (I<e.g.>,
2c8edc25
S
2580C<sub c { sub c; }>) could sometimes crash or loop infinitely. [perl
2581#129090]
2582
2583=item *
2584
fb5d4b1a 2585A crash in executing a regex with a non-anchored UTF-8 substring against a
a3a9a3d2
KW
2586target string that also used UTF-8 has been fixed.
2587L<[perl #129350]|https://rt.perl.org/Public/Bug/Display.html?id=129350>
2c8edc25
S
2588
2589=item *
2590
2591Previously, a shebang line like C<#!perl -i u> could be erroneously
95b17558 2592interpreted as requesting the C<-u> option. This has been fixed. [perl
2c8edc25
S
2593#129336]
2594
2595=item *
2596
2597The regex engine was previously producing incorrect results in some rare
2598situations when backtracking past a trie that matches only one thing; this
0f032fe1 2599showed up as capture buffers (C<$1>, C<$2>, I<etc.>) erroneously containing data
2c8edc25 2600from regex execution paths that weren't actually executed for the final
a3a9a3d2
KW
2601match.
2602L<[perl #129897]|https://rt.perl.org/Public/Bug/Display.html?id=129897>
2c8edc25
S
2603
2604=item *
2605
2606Certain regexes making use of the experimental C<regex_sets> feature could
a3a9a3d2
KW
2607trigger an assertion failure. This has been fixed.
2608L<[perl #129322]|https://rt.perl.org/Public/Bug/Display.html?id=129322>
2c8edc25
S
2609
2610=item *
2611
fce64130 2612Invalid assignments to a reference constructor (I<e.g.>, C<\eval=time>) could
a3a9a3d2
KW
2613sometimes crash in addition to giving a syntax error.
2614L<[perl #125679]|https://rt.perl.org/Public/Bug/Display.html?id=125679>
2c8edc25
S
2615
2616=item *
2617
2618The parser could sometimes crash if a bareword came after C<evalbytes>.
a3a9a3d2 2619L<[perl #129196]|https://rt.perl.org/Public/Bug/Display.html?id=129196>
2c8edc25
S
2620
2621=item *
2622
2623Autoloading via a method call would warn erroneously ("Use of inherited
2624AUTOLOAD for non-method") if there was a stub present in the package into
2625which the invocant had been blessed. The warning is no longer emitted in
a3a9a3d2
KW
2626such circumstances.
2627L<[perl #47047]|https://rt.perl.org/Public/Bug/Display.html?id=47047>
2c8edc25
S
2628
2629=item *
2630
2c8edc25 2631The use of C<splice> on arrays with nonexistent elements could cause other
a3a9a3d2
KW
2632operators to crash.
2633L<[perl #129164]|https://rt.perl.org/Public/Bug/Display.html?id=129164>
2c8edc25
S
2634
2635=item *
2636
2637Fixed case where C<re_untuit_start> will overshoot the length of a utf8
a3a9a3d2
KW
2638string.
2639L<[perl #129012]|https://rt.perl.org/Public/Bug/Display.html?id=129012>
2c8edc25
S
2640
2641=item *
2642
2643Handle C<CXt_SUBST> better in C<Perl_deb_stack_all>, previously it wasn't
2644checking that the I<current> C<cx> is the right type, and instead was always
a3a9a3d2
KW
2645checking the base C<cx> (effectively a noop).
2646L<[perl #129029]|https://rt.perl.org/Public/Bug/Display.html?id=129029>
2c8edc25
S
2647
2648=item *
2649
95b17558 2650Fixed two possible use-after-free bugs in C<Perl_yylex>. C<Perl_yylex>
2c8edc25 2651maintains up to two pointers into the parser buffer, one of which can
a3a9a3d2
KW
2652become stale under the right conditions.
2653L<[perl #129069]|https://rt.perl.org/Public/Bug/Display.html?id=129069>
2c8edc25
S
2654
2655=item *
2656
2657Fixed a crash with C<s///l> where it thought it was dealing with UTF-8
a3a9a3d2
KW
2658when it wasn't.
2659L<[perl #129038]|https://rt.perl.org/Public/Bug/Display.html?id=129038>
2c8edc25
S
2660
2661=item *
2662
2663Fixed place where regex was not setting the syntax error correctly.
a3a9a3d2 2664L<[perl #129122]|https://rt.perl.org/Public/Bug/Display.html?id=129122>
2c8edc25
S
2665
2666=item *
2667
df48f9a4 2668The C<&.> operator (and the C<"&"> operator, when it treats its arguments as
2c8edc25
S
2669strings) were failing to append a trailing null byte if at least one string
2670was marked as utf8 internally. Many code paths (system calls, regexp
2671compilation) still expect there to be a null byte in the string buffer
2672just past the end of the logical string. An assertion failure was the
a3a9a3d2
KW
2673result.
2674L<[perl #129287]|https://rt.perl.org/Public/Bug/Display.html?id=129287>
2c8edc25
S
2675
2676=item *
2677
2678Check C<pack_sockaddr_un()>'s return value because C<pack_sockaddr_un()>
2679silently truncates the supplied path if it won't fit into the C<sun_path>
95b17558 2680member of C<sockaddr_un>. This may change in the future, but for now
2c8edc25 2681check the path in theC<sockaddr> matches the desired path, and skip if
a3a9a3d2
KW
2682it doesn't.
2683L<[perl #128095]|https://rt.perl.org/Public/Bug/Display.html?id=128095>
2c8edc25
S
2684
2685=item *
2686
95b17558 2687Make sure C<PL_oldoldbufptr> is preserved in C<scan_heredoc()>. In some
a3a9a3d2
KW
2688cases this is used in building error messages.
2689L<[perl #128988]|https://rt.perl.org/Public/Bug/Display.html?id=128988>
2c8edc25
S
2690
2691=item *
2692
570ce26a 2693Fix segfault when run with C<-DC> options on DEBUGGING builds.
a3a9a3d2 2694L<[perl #129106]|https://rt.perl.org/Public/Bug/Display.html?id=129106>
2c8edc25
S
2695
2696=item *
2697
2698Fixed the parser error handling for an 'C<:attr(foo>' that does not have
df48f9a4 2699an ending 'C<")">'.
2c8edc25
S
2700
2701=item *
2702
2703Fix C<Perl_delimcpy()> to handle a backslash as last char, this
a3a9a3d2
KW
2704actually fixed two bugs,
2705L<[perl #129064]|https://rt.perl.org/Public/Bug/Display.html?id=129064> and
2706L<[perl #129176]|https://rt.perl.org/Public/Bug/Display.html?id=129176>.
2c8edc25
S
2707
2708=item *
2709
a3a9a3d2 2710L<[perl #129267]|https://rt.perl.org/Public/Bug/Display.html?id=129267> rework C<gv_fetchmethod_pvn_flags> separator parsing to
0f032fe1 2711prevent possible string overrun with invalid len in F<gv.c>
2c8edc25
S
2712
2713=item *
2714
2715Problems with in-place array sorts: code like C<@a = sort { ... } @a>,
2716where the source and destination of the sort are the same plain array, are
95b17558 2717optimised to do less copying around. Two side-effects of this optimisation
2c8edc25
S
2718were that the contents of C<@a> as visible to to sort routine were
2719partially sorted, and under some circumstances accessing C<@a> during the
95b17558 2720sort could crash the interpreter. Both these issues have been fixed, and
2c8edc25
S
2721Sort functions see the original value of C<@a>.
2722
2723=item *
2724
2725Non-ASCII string delimiters are now reported correctly in error messages
a3a9a3d2
KW
2726for unterminated strings.
2727L<[perl #128701]|https://rt.perl.org/Public/Bug/Display.html?id=128701>
2c8edc25
S
2728
2729=item *
2730
2731C<pack("p", ...)> used to emit its warning ("Attempt to pack pointer to
2732temporary value") erroneously in some cases, but has been fixed.
2733
2734=item *
2735
2736C<@DB::args> is now exempt from "used once" warnings. The warnings only
2737occurred under B<-w>, because F<warnings.pm> itself uses C<@DB::args>
2738multiple times.
2739
2740=item *
2741
2742The use of built-in arrays or hash slices in a double-quoted string no
2743longer issues a warning ("Possible unintended interpolation...") if the
2744variable has not been mentioned before. This affected code like
2745C<qq|@DB::args|> and C<qq|@SIG{'CHLD', 'HUP'}|>. (The special variables
2746C<@-> and C<@+> were already exempt from the warning.)
2747
2748=item *
2749
2750C<gethostent> and similar functions now perform a null check internally, to
d3972b39 2751avoid crashing with torsocks. This was a regression from v5.22. [perl
2c8edc25
S
2752#128740]
2753
2754=item *
2755
2756C<defined *{'!'}>, C<defined *{'['}>, and C<defined *{'-'}> no longer leak
2757memory if the typeglob in question has never been accessed before.
2758
2759=item *
2760
2c8edc25
S
2761Mentioning the same constant twice in a row (which is a syntax error) no
2762longer fails an assertion under debugging builds. This was a regression
a3a9a3d2
KW
2763from v5.20.
2764L<[perl #126482]|https://rt.perl.org/Public/Bug/Display.html?id=126482>
2c8edc25
S
2765
2766=item *
2767
2768Many issues relating to C<printf "%a"> of hexadecimal floating point
2769were fixed. In addition, the "subnormals" (formerly known as "denormals")
fb5d4b1a 2770floating point numbers are now supported both with the plain IEEE 754
2c8edc25
S
2771floating point numbers (64-bit or 128-bit) and the x86 80-bit
2772"extended precision". Note that subnormal hexadecimal floating
2773point literals will give a warning about "exponent underflow".
2774[perl #128843, #128889, #128890, #128893, #128909, #128919]
2775
2776=item *
2777
d3972b39 2778A regression in v5.24 with C<tr/\N{U+...}/foo/> when the code point was between
a3a9a3d2
KW
2779128 and 255 has been fixed.
2780L<[perl #128734]|https://rt.perl.org/Public/Bug/Display.html?id=128734>.
2c8edc25
S
2781
2782=item *
2783
2c8edc25
S
2784Use of a string delimiter whose code point is above 2**31 now works
2785correctly on platforms that allow this. Previously, certain characters,
2786due to truncation, would be confused with other delimiter characters
df48f9a4 2787with special meaning (such as C<"?"> in C<m?...?>), resulting
2c8edc25
S
2788in inconsistent behaviour. Note that this is non-portable,
2789and is based on Perl's extension to UTF-8, and is probably not
a3a9a3d2
KW
2790displayable nor enterable by any editor.
2791L<[perl #128738]|https://rt.perl.org/Public/Bug/Display.html?id=128738>
2c8edc25
S
2792
2793=item *
2794
df48f9a4 2795C<@{x> followed by a newline where C<"x"> represents a control or non-ASCII
2c8edc25 2796character no longer produces a garbled syntax error message or a crash.
a3a9a3d2 2797L<[perl #128951]|https://rt.perl.org/Public/Bug/Display.html?id=128951>
2c8edc25
S
2798
2799=item *
2800
2801An assertion failure with C<%: = 0> has been fixed.
2802L<[perl #128238]|https://rt.perl.org/Public/Bug/Display.html?id=128238>
2803
2804=item *
2805
2806In Perl 5.18, the parsing of C<"$foo::$bar"> was accidentally changed, such
2807that it would be treated as C<$foo."::".$bar>. The previous behavior, which
2808was to parse it as C<$foo:: . $bar>, has been restored.
2809L<[perl #128478]|https://rt.perl.org/Public/Bug/Display.html?id=128478>
2810
2811=item *
2812
2813Since Perl 5.20, line numbers have been off by one when perl is invoked with
2814the B<-x> switch. This has been fixed.
2815L<[perl #128508]|https://rt.perl.org/Public/Bug/Display.html?id=128508>
2816
2817=item *
2818
fce64130 2819Vivifying a subroutine stub in a deleted stash (I<e.g.>, C<delete $My::{"Foo::"};
2c8edc25
S
2820\&My::Foo::foo>) no longer crashes. It had begun crashing in Perl 5.18.
2821L<[perl #128532]|https://rt.perl.org/Public/Bug/Display.html?id=128532>
2822
2823=item *
2824
2825Some obscure cases of subroutines and file handles being freed at the same time
2826could result in crashes, but have been fixed. The crash was introduced in Perl
28275.22.
2828L<[perl #128597]|https://rt.perl.org/Public/Bug/Display.html?id=128597>
2829
2830=item *
2831
2832Code that looks for a variable name associated with an uninitialized value
fb5d4b1a 2833could cause an assertion failure in cases where magic is involved, such as
2c8edc25
S
2834C<$ISA[0][0]>. This has now been fixed.
2835L<[perl #128253]|https://rt.perl.org/Public/Bug/Display.html?id=128253>
2836
2837=item *
2838
2839A crash caused by code generating the warning "Subroutine STASH::NAME
2840redefined" in cases such as C<sub P::f{} undef *P::; *P::f =sub{};> has been
2841fixed. In these cases, where the STASH is missing, the warning will now appear
2842as "Subroutine NAME redefined".
2843L<[perl #128257]|https://rt.perl.org/Public/Bug/Display.html?id=128257>
2844
2845=item *
2846
2847Fixed an assertion triggered by some code that handles deprecated behavior in
fce64130 2848formats, I<e.g.>, in cases like this:
2c8edc25
S
2849
2850 format STDOUT =
2851 @
2852 0"$x"
2853
2854L<[perl #128255]|https://rt.perl.org/Public/Bug/Display.html?id=128255>
2855
2856=item *
2857
2858A possible divide by zero in string transformation code on Windows has been
2859avoided, fixing a crash when collating an empty string.
2860L<[perl #128618]|https://rt.perl.org/Public/Bug/Display.html?id=128618>
2861
2862=item *
2863
2864Some regular expression parsing glitches could lead to assertion failures with
e6abae1c 2865regular expressions such as C</(?E<lt>=/> and C</(?E<lt>!/>. This has now been fixed.
2c8edc25
S
2866L<[perl #128170]|https://rt.perl.org/Public/Bug/Display.html?id=128170>
2867
2868=item *
2869
2870C< until ($x = 1) { ... } > and C< ... until $x = 1 > now properly
a3a9a3d2
KW
2871warn when syntax warnings are enabled.
2872L<[perl #127333]|https://rt.perl.org/Public/Bug/Display.html?id=127333>
2c8edc25
S
2873
2874=item *
2875
2876socket() now leaves the error code returned by the system in C<$!> on
a3a9a3d2
KW
2877failure.
2878L<[perl #128316]|https://rt.perl.org/Public/Bug/Display.html?id=128316>
2c8edc25
S
2879
2880=item *
2881
2882Assignment variants of any bitwise ops under the C<bitwise> feature would
a3a9a3d2
KW
2883crash if the left-hand side was an array or hash.
2884L<[perl #128204]|https://rt.perl.org/Public/Bug/Display.html?id=128204>
2c8edc25
S
2885
2886=item *
2887
2888C<require> followed by a single colon (as in C<foo() ? require : ...> is
0f032fe1 2889now parsed correctly as C<require> with implicit C<$_>, rather than
a3a9a3d2
KW
2890C<require "">.
2891L<[perl #128307]|https://rt.perl.org/Public/Bug/Display.html?id=128307>
2c8edc25
S
2892
2893=item *
2894
2895Scalar C<keys %hash> can now be assigned to consistently in all scalar
2896lvalue contexts. Previously it worked for some contexts but not others.
2897
2898=item *
2899
2900List assignment to C<vec> or C<substr> with an array or hash for its first
2901argument used to result in crashes or "Can't coerce" error messages at run
2902time, unlike scalar assignment, which would give an error at compile time.
a3a9a3d2
KW
2903List assignment now gives a compile-time error, too.
2904L<[perl #128260]|https://rt.perl.org/Public/Bug/Display.html?id=128260>
2c8edc25
S
2905
2906=item *
2907
2908Expressions containing an C<&&> or C<||> operator (or their synonyms C<and>
95b17558 2909and C<or>) were being compiled incorrectly in some cases. If the left-hand
2c8edc25
S
2910side consisted of either a negated bareword constant or a negated C<do {}>
2911block containing a constant expression, and the right-hand side consisted of
2912a negated non-foldable expression, one of the negations was effectively
95b17558
KW
2913ignored. The same was true of C<if> and C<unless> statement modifiers,
2914though with the left-hand and right-hand sides swapped. This long-standing
a3a9a3d2
KW
2915bug has now been fixed.
2916L<[perl #127952]|https://rt.perl.org/Public/Bug/Display.html?id=127952>
2c8edc25
S
2917
2918=item *
2919
2920C<reset> with an argument no longer crashes when encountering stash entries
a3a9a3d2
KW
2921other than globs.
2922L<[perl #128106]|https://rt.perl.org/Public/Bug/Display.html?id=128106>
2c8edc25
S
2923
2924=item *
2925
2926Assignment of hashes to, and deletion of, typeglobs named C<*::::::> no
a3a9a3d2
KW
2927longer causes crashes.
2928L<[perl #128086]|https://rt.perl.org/Public/Bug/Display.html?id=128086>
2c8edc25
S
2929
2930=item *
2931
a3a9a3d2
KW
2932Handle C<SvIMMORTALs> in LHS of list assign.
2933L<[perl #129991]|https://rt.perl.org/Public/Bug/Display.html?id=129991>
2c8edc25
S
2934
2935=item *
2936
a3a9a3d2
KW
2937Assertion failure with user-defined Unicode-like properties.
2938L<[perl #130010]|https://rt.perl.org/Public/Bug/Display.html?id=130010>
2c8edc25
S
2939
2940=item *
2941
2942Fix error message for unclosed C<\N{> in regcomp.
2943
2944An unclosed C<\N{> could give the wrong error message
2945C<"\N{NAME} must be resolved by the lexer">.
2946
2947=item *
2948
2949List assignment in list context where the LHS contained aggregates and
2950where there were not enough RHS elements, used to skip scalar lvalues.
2951Previously, C<(($a,$b,@c,$d) = (1))> in list context returned C<($a)>; now
95b17558
KW
2952it returns C<($a,$b,$d)>. C<(($a,$b,$c) = (1))> is unchanged: it still
2953returns C<($a,$b,$c)>. This can be seen in the following:
2c8edc25
S
2954
2955 sub inc { $_++ for @_ }
2956 inc(($a,$b,@c,$d) = (10))
2957
2958Formerly, the values of C<($a,$b,$d)> would be left as C<(11,undef,undef)>;
2959now they are C<(11,1,1)>.
2960
2961=item *
2962
f632cffa
KW
2963Code like this: C</(?{ s!!! })/> can trigger infinite recursion on the C
2964stack (not the normal perl stack) when the last successful pattern in
2965scope is itself. We avoid the segfault by simply forbidding the use of
2966the empty pattern when it would resolve to the currently executing
a3a9a3d2
KW
2967pattern.
2968L<[perl #129903]|https://rt.perl.org/Public/Bug/Display.html?id=129903>
2c8edc25
S
2969
2970=item *
2971
0c092f6b 2972Avoid reading beyond the end of the line buffer when there's a
a3a9a3d2
KW
2973short UTF-8 character at the end.
2974L<[perl #128997]|https://rt.perl.org/Public/Bug/Display.html?id=128997>
2c8edc25
S
2975
2976=item *
2977
a3a9a3d2
KW
2978Fix firstchar bitmap under utf8 with prefix optimisation.
2979L<[perl #129950]|https://rt.perl.org/Public/Bug/Display.html?id=129950>
2c8edc25
S
2980
2981=item *
2982
a3a9a3d2
KW
2983Make F<Carp/t/arg_string.t>: be liberal in C<f>/C<p> formats.
2984L<[perl #129954]|https://rt.perl.org/Public/Bug/Display.html?id=129954>
2c8edc25
S
2985
2986=item *
2987
a3a9a3d2
KW
2988Make C<do "a\0b"> fail silently instead of throwing an error.
2989L<[perl #129928]|https://rt.perl.org/Public/Bug/Display.html?id=129928>
2c8edc25
S
2990
2991=item *
2992
a3a9a3d2
KW
2993Make C<chdir> allocate the stack it needs.
2994L<[perl #129130]|https://rt.perl.org/Public/Bug/Display.html?id=129130>
2c8edc25 2995
acea3104
KW
2996=item *
2997
2998C<do> errors now refer to C<do> (not C<require>).
2999
3000=item *
3001
3002Executing C<undef $x> where C<$x> is tied or magical no longer incorrectly
3003blames the variable for an uninitialized-value warning encountered by the
3004tied/magical code.
3005
3006=item *
3007
3008Code like C<$x = $x . "a"> was incorrectly failing to yield a
3009L<use of uninitialized value|perldiag/"Use of uninitialized value%s">
3010warning when C<$x> was a lexical variable with an undefined value. That has
a3a9a3d2
KW
3011now been fixed.
3012L<[perl #127877]|https://rt.perl.org/Public/Bug/Display.html?id=127877>
acea3104
KW
3013
3014=item *
3015
3016C<undef *_; shift> or C<undef *_; pop> inside a subroutine, with no
3017argument to C<shift> or C<pop>, began crashing in Perl 5.14, but has now
3018been fixed.
3019
3020=item *
3021
3022C<< "string$scalar-E<gt>$*" >> now correctly prefers concat overloading to
3023string overloading if C<< $scalar-E<gt>$* >> returns an overloaded object,
3024bringing it into consistency with C<$$scalar>.
3025
3026=item *
3027
3028C<< /@0{0*-E<gt>@*/*0 >> and similar contortions used to crash, but no longer
a3a9a3d2
KW
3029do, but merely produce a syntax error.
3030L<[perl #128171]|https://rt.perl.org/Public/Bug/Display.html?id=128171>
acea3104
KW
3031
3032=item *
3033
3034C<do> or C<require> with a reference or typeglob which, when stringified,
3035contains a null character started crashing in Perl 5.20, but has now been
a3a9a3d2
KW
3036fixed.
3037L<[perl #128182]|https://rt.perl.org/Public/Bug/Display.html?id=128182>
acea3104
KW
3038
3039=item *
3040
3041Improve error for missing C<tie()> package/method. This brings the error messages
3042in line with the ones used for normal method calls, despite not using
3043call_method().
3044
2c8edc25
S
3045=back
3046
3047=head1 Known Problems
3048
3049=over 4
3050
3051=item *
3052
3053Some modules have been broken by the L<context stack rework|/Internal Changes>.
fb5d4b1a
KW
3054These modules were relying on non-guaranteed implementation details in
3055the perl interpreter.
2c8edc25
S
3056Their maintainers have been informed, and should contact perl5-porters for
3057advice if needed. Below is a subset of these modules:
3058
3059=over 4
3060
3061=item * L<Algorithm::Permute>
3062
3063=item * L<Coro>
3064
fb5d4b1a
KW
3065L<Coro> and Perl 5.22 were already incompatible due to a change in the perl
3066interpreter,
2c8edc25
S
3067and the reworking on the perl context stack creates a further incompatibility.
3068perl5-porters has L<discussed the issue on the mailing
3069list|http://www.nntp.perl.org/group/perl.perl5.porters/2016/05/msg236174.html>.
3070
3071=item * L<Data::Alias>
3072
3073=item * L<RPerl>
3074
3075=item * L<Scope::Upper>
3076
3077=item * L<TryCatch>
3078
3079=back
3080
3081=item *
3082
53799a91 3083The module L<lexical::underscore> no longer works on Perl 5.24, because perl
2c8edc25
S
3084no longer has a lexical C<$_>!
3085
3086=item *
3087
53799a91 3088C<mod_perl> has been patched for compatibility for v5.22 and later but no
2c8edc25
S
3089release has been made. The relevant patch (and other changes) can be found in
3090their source code repository, L<mirrored at
3091GitHub|https://github.com/apache/mod_perl/commit/82827132efd3c2e25cc413c85af61bb63375da6e>.
3092
3093=back
3094
3095=head1 Errata From Previous Releases
3096
3097=over 4
3098
3099=item *
3100
ee8180b8 3101Parsing bad POSIX charclasses no longer leaks memory.
2c8edc25
S
3102L<[perl #128313]|https://rt.perl.org/Public/Bug/Display.html?id=128313>
3103
3104=item *
3105
53799a91 3106Fixed issues with recursive regexes. The behavior was fixed in Perl 5.24.
2c8edc25
S
3107L<[perl #126182]|https://rt.perl.org/Public/Bug/Display.html?id=126182>
3108
3109=back
3110
3111=head1 Obituary
3112
3113Jon Portnoy (AVENJ), a prolific Perl author and admired Gentoo community
95b17558 3114member, has passed away on August 10, 2016. He will be remembered and
c94c0e4f 3115missed by all those who he came in contact with, and enriched with his
2c8edc25
S
3116intellect, wit, and spirit.
3117
c94c0e4f 3118It is with great sadness that we also note Kip Hampton's passing. Probably
2c8edc25
S
3119best known as the author of the Perl & XML column on XML.com, he was a
3120core contributor to AxKit, an XML server platform that became an Apache
95b17558
KW
3121Foundation project. He was a frequent speaker in the early days at
3122OSCON, and most recently at YAPC::NA in Madison. He was frequently on
2c8edc25
S
3123irc.perl.org as `ubu`, generally in the #axkit-dahut community, the
3124group responsible for YAPC::NA Asheville in 2011.
a049258c 3125
2c8edc25
S
3126Kip and his constant contributions to the community will be greatly
3127missed.
a049258c
S
3128
3129=head1 Acknowledgements
2e0dcc12 3130
0cc8c746 3131Perl 5.26.0 represents approximately 12 months of development since Perl 5.24.0
c2948ced 3132and contains approximately 370,000 lines of changes across 2,600 files from 86
0cc8c746
S
3133authors.
3134
3135Excluding auto-generated files, documentation and release tools, there were
3136approximately 230,000 lines of changes to 1,800 .pm, .t, .c and .h files.
3137
3138Perl continues to flourish into its third decade thanks to a vibrant community
95b17558 3139of users and developers. The following people are known to have contributed the
ad543fb2 3140improvements that became Perl 5.26.0:
0cc8c746
S
3141
3142Aaron Crane, Abigail, Ævar Arnfjörð Bjarmason, Alex Vandiver, Andreas
3143König, Andreas Voegele, Andrew Fresh, Andy Lester, Aristotle Pagaltzis, Chad
3144Granum, Chase Whitener, Chris 'BinGOs' Williams, Chris Lamb, Christian Hansen,
3145Christian Millour, Colin Newell, Craig A. Berry, Dagfinn Ilmari Mannsåker, Dan
c2948ced
S
3146Collins, Daniel Dragan, Dave Cross, Dave Rolsky, David Golden, David H.
3147Gutteridge, David Mitchell, Dominic Hargreaves, Doug Bell, E. Choroba, Ed Avis,
3148Father Chrysostomos, François Perrad, Hauke D, H.Merijn Brand, Hugo van der
3149Sanden, Ivan Pozdeev, James E Keenan, James Raspass, Jarkko Hietaniemi, Jerry
3150D. Hedden, Jim Cromie, J. Nick Koston, John Lightsey, Karen Etheridge, Karl
3151Williamson, Leon Timmermans, Lukas Mai, Matthew Horsfall, Maxwell Carey, Misty
3152De Meo, Neil Bowers, Nicholas Clark, Nicolas R., Niko Tyni, Pali, Paul
3153Marquess, Peter Avalos, Petr Písař, Pino Toscano, Rafael Garcia-Suarez, Reini
3154Urban, Renee Baecker, Ricardo Signes, Richard Levitte, Rick Delaney, Salvador
3155Fandiño, Samuel Thibault, Sawyer X, Sébastien Aperghis-Tramoni, Sergey
3156Aleynikov, Shlomi Fish, Smylers, Stefan Seifert, Steffen Müller, Stevan
3157Little, Steve Hay, Steven Humphrey, Sullivan Beck, Theo Buehler, Thomas Sibley,
3158Todd Rinaldo, Tomasz Konojacki, Tony Cook, Unicode Consortium, Yaroslav Kuzmin,
3159Yves Orton, Zefram.
0cc8c746
S
3160
3161The list above is almost certainly incomplete as it is automatically generated
95b17558 3162from version control history. In particular, it does not include the names of
0cc8c746
S
3163the (very much appreciated) contributors who reported issues to the Perl bug
3164tracker.
3165
3166Many of the changes included in this version originated in the CPAN modules
95b17558 3167included in Perl's core. We're grateful to the entire CPAN community for
0cc8c746
S
3168helping Perl to flourish.
3169
3170For a more complete list of all of Perl's historical contributors, please see
3171the F<AUTHORS> file in the Perl source distribution.
f5b73711 3172
44691e6f
AB
3173=head1 Reporting Bugs
3174
2c8edc25
S
3175If you find what you think is a bug, you might check the articles recently
3176posted to the comp.lang.perl.misc newsgroup and the perl bug database at
3177L<https://rt.perl.org/> . There may also be information at
4b8803f0 3178L<http://www.perl.org/> , the Perl Home Page.
44691e6f 3179
e08634c5
SH
3180If you believe you have an unreported bug, please run the L<perlbug> program
3181included with your release. Be sure to trim your bug down to a tiny but
3182sufficient test case. Your bug report, along with the output of C<perl -V>,
7c825fca 3183will be sent off to C<perlbug@perl.org> to be analysed by the Perl porting team.
44691e6f 3184
87c118b9
DM
3185If the bug you are reporting has security implications which make it
3186inappropriate to send to a publicly archived mailing list, then see
c0ea3294
SH
3187L<perlsec/SECURITY VULNERABILITY CONTACT INFORMATION>
3188for details of how to report the issue.
44691e6f
AB
3189
3190=head1 SEE ALSO
3191
e08634c5
SH
3192The F<Changes> file for an explanation of how to view exhaustive details on
3193what changed.
44691e6f
AB
3194
3195The F<INSTALL> file for how to build Perl.
3196
3197The F<README> file for general stuff.
3198
3199The F<Artistic> and F<Copying> files for copyright information.
3200
3201=cut