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more perldelta fixups.
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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
2c8edc25 42
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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
96e0fd86 218=item * A new deprecation warning issued by C<do>.
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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
96e0fd86 225deprecation warning is now issued whenever C<do> fails to load a file which
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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
96e0fd86 360=head2 New C<-Di> switch is now required for PerlIO debugging output
2c8edc25 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
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371Perl now requires the C<-Di> switch to be present before it will produce
372PerlIO debugging
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373output. By default this is written to C<stderr>, but can optionally
374be redirected to a file by setting the C<PERLIO_DEBUG> environment
375variable.
a049258c 376
3ee934f7 377If perl is running setuid or the C<-T> switch was supplied,
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378C<PERLIO_DEBUG> is ignored and the debugging output is sent to
379C<stderr> as for any other C<-D> switch.
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380
381=head1 Incompatible Changes
382
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383=head2 Unescaped literal C<"{"> characters in regular expression
384patterns are no longer permissible
a049258c 385
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386You have to now say something like C<"\{"> or C<"[{]"> to specify to
387match a LEFT CURLY BRACKET; otherwise it is a fatal pattern compilation
388error. This change will allow future extensions to the language.
389
390These have been deprecated since v5.16, with a deprecation message
391raised for some uses starting in v5.22. Unfortunately, the code added
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392to raise the message was buggy, and failed to warn in some cases where
393it should have. Therefore, enforcement of this ban for these cases is
394deferred until Perl 5.30, but the code has been fixed to raise a
395default-on deprecation message for them in the meantime.
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396
397Some uses of literal C<"{"> occur in contexts where we do not foresee
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398the meaning ever being anything but the literal, such as the very first
399character in the pattern, or after a C<"|"> meaning alternation. Thus
400
401 qr/{fee|{fie/
402
403matches either of the strings C<{fee> or C<{fie>. To avoid forcing
404unnecessary code changes, these uses do not need to be escaped, and no
405warning is raised about them, and there are no current plans to change this.
406
407But it is always correct to escape C<"{">, and the simple rule to
408remember is to always do so.
a049258c 409
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410See 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>>.
411
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412=head2 C<scalar(%hash)> return signature changed
413
414The value returned for C<scalar(%hash)> will no longer show information about
415the buckets allocated in the hash. It will simply return the count of used
416keys. It is thus equivalent to C<0+keys(%hash)>.
417
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418A form of backwards compatibility is provided via
419L<C<Hash::Util::bucket_ratio()>|Hash::Util/bucket_ratio> which provides
420the same behavior as
421C<scalar(%hash)> provided in Perl 5.24 and earlier.
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422
423=head2 C<keys> returned from an lvalue subroutine
424
425C<keys> returned from an lvalue subroutine can no longer be assigned
426to in list context.
427
428 sub foo : lvalue { keys(%INC) }
429 (foo) = 3; # death
430 sub bar : lvalue { keys(@_) }
431 (bar) = 3; # also an error
432
433This makes the lvalue sub case consistent with C<(keys %hash) = ...> and
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434C<(keys @_) = ...>, which are also errors.
435L<[perl #128187]|https://rt.perl.org/Public/Bug/Display.html?id=128187>
a049258c 436
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437=head2 C<${^ENCODING}> has been removed
438
439Consequently, the L<encoding> pragma's default mode is no longer supported. If
440you still need to write your source code in encodings other than UTF-8, use a
441source filter such as L<Filter::Encoding> on CPAN or L<encoding>'s C<Filter>
442option.
443
0f032fe1 444=head2 C<POSIX::tmpnam()> has been removed
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445
446The fundamentally unsafe C<tmpnam()> interface was deprecated in
53799a91 447Perl 5.22 and has now been removed. In its place you can use,
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448for example, the L<File::Temp> interfaces.
449
450=head2 require ::Foo::Bar is now illegal.
451
95b17558 452Formerly, C<require ::Foo::Bar> would try to read F</Foo/Bar.pm>. Now any
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453bareword require which starts with a double colon dies instead.
454
455=head2 Literal control character variable names are no longer permissible
456
457A variable name may no longer contain a literal control character under
458any circumstances. These previously were allowed in single-character
459names on ASCII platforms, but have been deprecated there since Perl
4605.20. This affects things like C<$I<\cT>>, where I<\cT> is a literal
461control (such as a C<NAK> or C<NEGATIVE ACKNOWLEDGE> character) in the
462source code.
463
464=head2 C<NBSP> is no longer permissible in C<\N{...}>
465
466The name of a character may no longer contain non-breaking spaces. It
53799a91 467has been deprecated to do so since Perl 5.22.
8d25d2f3 468
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469=head1 Deprecations
470
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471=head2 String delimiters that aren't stand-alone graphemes are now deprecated
472
473In order for Perl to eventually allow string delimiters to be Unicode
474grapheme clusters (which look like a single character, but may be
0f275d26 475a sequence of several ones), we have to stop allowing a single character
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476delimiter that isn't a grapheme by itself. These are unlikely to exist
477in actual code, as they would typically display as attached to the
478character in front of them.
479
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480=head2 C<\cI<X>> that maps to a printable is no longer deprecated
481
482This means we have no plans to remove this feature. It still raises a
483warning, but only if syntax warnings are enabled. The feature was
484originally intended to be a way to express non-printable characters that
485don't have a mnemonic (C<\t> and C<\n> are mnemonics for two
486non-printable characters, but most non-printables don't have a
487mnemonic.) But the feature can be used to specify a few printable
488characters, though those are more clearly expressed as the printable
489itself. See
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490L<http://www.nntp.perl.org/group/perl.perl5.porters/2017/02/msg242944.html>.
491
2c8edc25 492=head1 Performance Enhancements
a049258c 493
2c8edc25 494=over 4
a049258c 495
2c8edc25 496=item *
a049258c 497
fce64130 498A hash in boolean context is now sometimes faster, I<e.g.>
a049258c 499
2c8edc25 500 if (!%h) { ... }
a049258c 501
8928e7db 502This was already special-cased, but some cases were missed (such as
96e0fd86 503C<grep %$_, @AoH>), and even the ones which weren't have been improved.
a049258c 504
2c8edc25 505=item * New Faster Hash Function on 64 bit builds
a049258c 506
95b17558 507We use a different hash function for short and long keys. This should
2c8edc25 508improve performance and security, especially for long keys.
a049258c 509
2c8edc25 510=item * readline is faster
a049258c 511
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512Reading from a file line-by-line with C<readline()> or C<< E<lt>E<gt> >> should
513now typically be faster due to a better implementation of the code that
514searches for the next newline character.
515
516=item *
a049258c 517
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518Assigning one reference to another, I<e.g.> C<$ref1 = $ref2> has been
519optimized in some cases.
a049258c 520
2c8edc25 521=item *
ad5c8857 522
96e0fd86
DM
523Remove some exceptions to creating Copy-on-Write strings. The string
524buffer growth algorithm has been altered slightly so that you're less
525likely to encounter a string which which can't be COWed.
2c8edc25
S
526
527=item *
528
8928e7db
DM
529Better optimise array and hash assignment: where an array or hash appears
530in the LHS of a list assignment, such as C<(..., @a) = (...);>, it's
531likely to be considerably faster, especially if it involves emptying the
96e0fd86 532array/hash. For example this code runs about a third faster compared to
d3972b39 533Perl 5.24.0:
d053832c
AB
534
535 my @a;
8928e7db 536 for my $i (1..10_000_000) {
d053832c
AB
537 @a = (1,2,3);
538 @a = ();
539 }
540
2c8edc25
S
541=item *
542
543Converting a single-digit string to a number is now substantially faster.
544
545=item *
546
96e0fd86
DM
547The C<split> builtin is now slightly faster in many cases: in particular
548for the two specially-handled forms
549
550 my @a = split ...;
551 local @a = split ...;
2c8edc25
S
552
553=item *
554
555The rather slow implementation for the experimental subroutine signatures
556feature has been made much faster; it is now comparable in speed with the
96e0fd86 557traditional C<my ($a, $b, @c) = @_>.
7ca0bfc4 558
fbe3f407
S
559=item *
560
2c8edc25 561Bareword constant strings are now permitted to take part in constant
95b17558 562folding. They were originally exempted from constant folding in August 1999,
2c8edc25 563during the development of Perl 5.6, to ensure that C<use strict "subs">
95b17558 564would still apply to bareword constants. That has now been accomplished a
2c8edc25
S
565different way, so barewords, like other constants, now gain the performance
566benefits of constant folding.
567
568This also means that void-context warnings on constant expressions of
569barewords now report the folded constant operand, rather than the operation;
570this matches the behaviour for non-bareword constants.
a049258c
S
571
572=back
573
2c8edc25
S
574=head1 Modules and Pragmata
575
a049258c
S
576=head2 Updated Modules and Pragmata
577
578=over 4
fbe3f407 579
759020c9 580=item *
7ca0bfc4 581
0cc8c746
S
582L<Archive::Tar> has been upgraded from version 2.04 to 2.24.
583
584=item *
585
586L<arybase> has been upgraded from version 0.11 to 0.12.
587
588=item *
589
590L<attributes> has been upgraded from version 0.27 to 0.29.
a049258c 591
2c8edc25 592The deprecation message for the C<:unique> and C<:locked> attributes
0f275d26 593now mention that they will disappear in Perl 5.28.
a049258c 594
2c8edc25 595=item *
a049258c 596
0cc8c746
S
597L<B> has been upgraded from version 1.62 to 1.68.
598
599=item *
600
601L<B::Concise> has been upgraded from version 0.996 to 0.999.
2c8edc25
S
602
603Its output is now more descriptive for C<op_private> flags.
d5c7a4fc 604
759020c9
S
605=item *
606
0cc8c746
S
607L<B::Debug> has been upgraded from version 1.23 to 1.24.
608
609=item *
610
611L<B::Deparse> has been upgraded from version 1.37 to 1.40.
612
613=item *
614
2c8edc25 615L<B::Xref> has been upgraded from version 1.05 to 1.06.
a049258c 616
a3a9a3d2
KW
617It now uses 3-arg C<open()> instead of 2-arg C<open()>.
618L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
a049258c 619
2c8edc25 620=item *
a049258c 621
0cc8c746
S
622L<base> has been upgraded from version 2.23 to 2.25.
623
624=item *
625
626L<bignum> has been upgraded from version 0.42 to 0.47.
627
628=item *
629
630L<Carp> has been upgraded from version 1.40 to 1.42.
631
632=item *
633
634L<charnames> has been upgraded from version 1.43 to 1.44.
635
636=item *
637
638L<Compress::Raw::Bzip2> has been upgraded from version 2.069 to 2.074.
639
640=item *
641
642L<Compress::Raw::Zlib> has been upgraded from version 2.069 to 2.074.
643
644=item *
645
646L<Config::Perl::V> has been upgraded from version 0.25 to 0.28.
647
648=item *
649
650L<CPAN> has been upgraded from version 2.11 to 2.18.
651
652=item *
653
654L<CPAN::Meta> has been upgraded from version 2.150005 to 2.150010.
655
656=item *
657
658L<Data::Dumper> has been upgraded from version 2.160 to 2.167.
a049258c 659
2c8edc25 660The XS implementation now supports Deparse.
a049258c 661
2c8edc25 662=item *
a049258c 663
0cc8c746
S
664L<DB_File> has been upgraded from version 1.835 to 1.840.
665
666=item *
667
668L<Devel::Peek> has been upgraded from version 1.23 to 1.26.
669
670=item *
671
672L<Devel::PPPort> has been upgraded from version 3.32 to 3.35.
673
674=item *
675
2c8edc25 676L<Devel::SelfStubber> has been upgraded from version 1.05 to 1.06.
a049258c 677
a3a9a3d2
KW
678It now uses 3-arg C<open()> instead of 2-arg C<open()>.
679L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
a049258c 680
2c8edc25 681=item *
a049258c 682
0cc8c746 683L<diagnostics> has been upgraded from version 1.34 to 1.36.
a049258c 684
a3a9a3d2
KW
685It now uses 3-arg C<open()> instead of 2-arg C<open()>.
686L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
7ca0bfc4 687
ad5c8857 688=item *
7ca0bfc4 689
0cc8c746
S
690L<Digest> has been upgraded from version 1.17 to 1.17_01.
691
692=item *
693
694L<Digest::MD5> has been upgraded from version 2.54 to 2.55.
695
696=item *
697
698L<Digest::SHA> has been upgraded from version 5.95 to 5.96.
699
700=item *
701
702L<DynaLoader> has been upgraded from version 1.38 to 1.42.
703
704=item *
705
706L<Encode> has been upgraded from version 2.80 to 2.88.
707
708=item *
709
710L<encoding> has been upgraded from version 2.17 to 2.19.
8f7edc68 711
ee8180b8 712This module's default mode is no longer supported. It now
2c8edc25 713dies when imported, unless the C<Filter> option is being used.
d5c7a4fc 714
2c8edc25 715=item *
d5c7a4fc 716
2c8edc25 717L<encoding::warnings> has been upgraded from version 0.12 to 0.13.
a049258c 718
ee8180b8 719This module is no longer supported. It emits a warning to
2c8edc25 720that effect and then does nothing.
a049258c 721
2c8edc25 722=item *
d5c7a4fc 723
0cc8c746 724L<Errno> has been upgraded from version 1.25 to 1.28.
a049258c 725
96e0fd86 726It now documents that using C<%!> automatically loads Errno for you.
d5c7a4fc 727
a3a9a3d2
KW
728It now uses 3-arg C<open()> instead of 2-arg C<open()>.
729L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
3abe9611 730
c714fb1f 731=item *
3ce6a296 732
2c8edc25 733L<ExtUtils::Embed> has been upgraded from version 1.33 to 1.34.
a049258c 734
a3a9a3d2
KW
735It now uses 3-arg C<open()> instead of 2-arg C<open()>.
736L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
a049258c 737
2c8edc25 738=item *
a049258c 739
0cc8c746
S
740L<ExtUtils::MakeMaker> has been upgraded from version 7.10_01 to 7.24.
741
742=item *
743
744L<ExtUtils::Miniperl> has been upgraded from version 1.05 to 1.06.
745
746=item *
747
748L<ExtUtils::ParseXS> has been upgraded from version 3.31 to 3.34.
749
750=item *
751
752L<ExtUtils::Typemaps> has been upgraded from version 3.31 to 3.34.
753
754=item *
755
756L<feature> has been upgraded from version 1.42 to 1.47.
2c8edc25 757
a049258c 758=item *
5c92a635 759
0cc8c746
S
760L<File::Copy> has been upgraded from version 2.31 to 2.32.
761
762=item *
763
764L<File::Fetch> has been upgraded from version 0.48 to 0.52.
765
766=item *
767
768L<File::Glob> has been upgraded from version 1.26 to 1.28.
d5c7a4fc 769
96e0fd86 770It now Issues a deprecation message for C<File::Glob::glob()>.
d5c7a4fc 771
2c8edc25 772=item *
d5c7a4fc 773
0cc8c746
S
774L<File::Spec> has been upgraded from version 3.63 to 3.67.
775
776=item *
777
778L<FileHandle> has been upgraded from version 2.02 to 2.03.
779
780=item *
781
2c8edc25 782L<Filter::Simple> has been upgraded from version 0.92 to 0.93.
a049258c 783
2c8edc25 784It no longer treats C<no MyFilter> immediately following C<use MyFilter> as
a3a9a3d2
KW
785end-of-file.
786L<[perl #107726]|https://rt.perl.org/Public/Bug/Display.html?id=107726>
64afbd29
DM
787
788=item *
789
0cc8c746
S
790L<Getopt::Long> has been upgraded from version 2.48 to 2.49.
791
792=item *
793
794L<Getopt::Std> has been upgraded from version 1.11 to 1.12.
795
796=item *
797
798L<Hash::Util> has been upgraded from version 0.19 to 0.22.
799
800=item *
801
802L<HTTP::Tiny> has been upgraded from version 0.056 to 0.070.
a049258c 803
2c8edc25 804Internal 599-series errors now include the redirect history.
a049258c 805
2c8edc25 806=item *
a049258c 807
0cc8c746 808L<I18N::LangTags> has been upgraded from version 0.40 to 0.42.
a049258c 809
a3a9a3d2
KW
810It now uses 3-arg C<open()> instead of 2-arg C<open()>.
811L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
a049258c 812
2c8edc25 813=item *
a049258c 814
0cc8c746
S
815L<IO> has been upgraded from version 1.36 to 1.38.
816
817=item *
818
96e0fd86 819IO::Compress has been upgraded from version 2.069 to 2.074.
0cc8c746
S
820
821=item *
822
823L<IO::Socket::IP> has been upgraded from version 0.37 to 0.38.
824
825=item *
826
827L<IPC::Cmd> has been upgraded from version 0.92 to 0.96.
828
829=item *
830
831L<IPC::SysV> has been upgraded from version 2.06_01 to 2.07.
832
833=item *
834
835L<JSON::PP> has been upgraded from version 2.27300 to 2.27400_02.
836
837=item *
838
2c8edc25
S
839L<lib> has been upgraded from version 0.63 to 0.64.
840
a3a9a3d2
KW
841It now uses 3-arg C<open()> instead of 2-arg C<open()>.
842L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
faab9793 843
c714fb1f 844=item *
ad5c8857 845
0cc8c746
S
846L<List::Util> has been upgraded from version 1.42_02 to 1.46_02.
847
848=item *
849
850L<Locale::Codes> has been upgraded from version 3.37 to 3.42.
851
852=item *
853
854L<Locale::Maketext> has been upgraded from version 1.26 to 1.28.
855
856=item *
857
858L<Locale::Maketext::Simple> has been upgraded from version 0.21 to 0.21_01.
859
860=item *
861
862L<Math::BigInt> has been upgraded from version 1.999715 to 1.999806.
ad5c8857 863
2c8edc25 864=item *
2e0dcc12 865
0cc8c746
S
866L<Math::BigInt::FastCalc> has been upgraded from version 0.40 to 0.5005.
867
868=item *
869
870L<Math::BigRat> has been upgraded from version 0.260802 to 0.2611.
871
872=item *
873
874L<Math::Complex> has been upgraded from version 1.59 to 1.5901.
875
876=item *
877
878L<Memoize> has been upgraded from version 1.03 to 1.03_01.
879
880=item *
881
882L<Module::CoreList> has been upgraded from version 5.20170420 to 5.20170520.
883
884=item *
885
886L<Module::Load::Conditional> has been upgraded from version 0.64 to 0.68.
887
888=item *
889
890L<Module::Metadata> has been upgraded from version 1.000031 to 1.000033.
891
892=item *
893
894L<mro> has been upgraded from version 1.18 to 1.20.
895
896=item *
897
898L<Net::Ping> has been upgraded from version 2.43 to 2.55.
d5c7a4fc 899
2c8edc25
S
900IPv6 addresses and C<AF_INET6> sockets are now supported, along with several
901other enhancements.
d5c7a4fc 902
a049258c 903=item *
d5c7a4fc 904
0cc8c746
S
905L<NEXT> has been upgraded from version 0.65 to 0.67.
906
907=item *
908
909L<Opcode> has been upgraded from version 1.34 to 1.39.
910
911=item *
912
913L<open> has been upgraded from version 1.10 to 1.11.
914
915=item *
916
2c8edc25 917L<OS2::Process> has been upgraded from version 1.11 to 1.12.
a049258c 918
a3a9a3d2
KW
919It now uses 3-arg C<open()> instead of 2-arg C<open()>.
920L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
a049258c 921
2c8edc25 922=item *
a049258c 923
2c8edc25 924L<overload> has been upgraded from version 1.26 to 1.28.
a049258c 925
2c8edc25 926Its compilation speed has been improved slightly.
a049258c 927
2c8edc25
S
928=item *
929
0cc8c746
S
930L<parent> has been upgraded from version 0.234 to 0.236.
931
932=item *
933
2c8edc25
S
934L<perl5db.pl> has been upgraded from version 1.50 to 1.51.
935
96e0fd86 936It now ignores F</dev/tty> on non-Unix systems.
a3a9a3d2 937L<[perl #113960]|https://rt.perl.org/Public/Bug/Display.html?id=113960>
2c8edc25
S
938
939=item *
940
0cc8c746
S
941L<Perl::OSType> has been upgraded from version 1.009 to 1.010.
942
943=item *
944
945L<perlfaq> has been upgraded from version 5.021010 to 5.021011.
946
947=item *
948
949L<PerlIO> has been upgraded from version 1.09 to 1.10.
950
951=item *
952
953L<PerlIO::encoding> has been upgraded from version 0.24 to 0.25.
954
955=item *
956
957L<PerlIO::scalar> has been upgraded from version 0.24 to 0.26.
958
959=item *
960
961L<Pod::Checker> has been upgraded from version 1.60 to 1.73.
962
963=item *
964
965L<Pod::Functions> has been upgraded from version 1.10 to 1.11.
966
967=item *
968
969L<Pod::Html> has been upgraded from version 1.22 to 1.2202.
970
971=item *
972
973L<Pod::Perldoc> has been upgraded from version 3.25_02 to 3.28.
974
975=item *
976
977L<Pod::Simple> has been upgraded from version 3.32 to 3.35.
978
979=item *
980
981L<Pod::Usage> has been upgraded from version 1.68 to 1.69.
982
983=item *
984
96e0fd86
DM
985L<POSIX> has been upgraded from version 1.65 to 1.76.
986
987This remedies several defects in making its symbols exportable.
a3a9a3d2 988L<[perl #127821]|https://rt.perl.org/Public/Bug/Display.html?id=127821>
96e0fd86 989
2c8edc25
S
990The C<POSIX::tmpnam()> interface has been removed,
991see L</"POSIX::tmpnam() has been removed">.
96e0fd86 992
2c8edc25
S
993Trying to import POSIX subs that have no real implementations
994(like C<POSIX::atend()>) now fails at import time, instead of
995waiting until runtime.
996
997=item *
998
0cc8c746 999L<re> has been upgraded from version 0.32 to 0.34
2c8edc25
S
1000
1001This adds support for the new L<C<E<47>xx>|perlre/E<sol>x and E<sol>xx>
1002regular expression pattern modifier, and a change to the L<S<C<use re
1003'strict'>>|re/'strict' mode> experimental feature. When S<C<re
1004'strict'>> is enabled, a warning now will be generated for all
df48f9a4 1005unescaped uses of the two characters C<"}"> and C<"]"> in regular
2c8edc25 1006expression patterns (outside bracketed character classes) that are taken
df48f9a4 1007literally. This brings them more in line with the C<")"> character which
2c8edc25
S
1008is always a metacharacter unless escaped. Being a metacharacter only
1009sometimes, depending on action at a distance, can lead to silently
1010having the pattern mean something quite different than was intended,
1011which the S<C<re 'strict'>> mode is intended to minimize.
1012
1013=item *
1014
0cc8c746
S
1015L<Safe> has been upgraded from version 2.39 to 2.40.
1016
1017=item *
1018
1019L<Scalar::Util> has been upgraded from version 1.42_02 to 1.46_02.
1020
1021=item *
1022
1023L<Storable> has been upgraded from version 2.56 to 2.62.
2c8edc25 1024
a3a9a3d2
KW
1025Fixes
1026L<[perl #130098]|https://rt.perl.org/Public/Bug/Display.html?id=130098>.
2c8edc25
S
1027
1028=item *
1029
0cc8c746
S
1030L<Symbol> has been upgraded from version 1.07 to 1.08.
1031
1032=item *
1033
1034L<Sys::Syslog> has been upgraded from version 0.33 to 0.35.
1035
1036=item *
1037
1038L<Term::ANSIColor> has been upgraded from version 4.04 to 4.06.
1039
1040=item *
1041
2c8edc25
S
1042L<Term::ReadLine> has been upgraded from version 1.15 to 1.16.
1043
a3a9a3d2
KW
1044It now uses 3-arg C<open()> instead of 2-arg C<open()>.
1045L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
2c8edc25
S
1046
1047=item *
1048
0cc8c746 1049L<Test> has been upgraded from version 1.28 to 1.30.
2c8edc25 1050
a3a9a3d2
KW
1051It now uses 3-arg C<open()> instead of 2-arg C<open()>.
1052L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
2c8edc25
S
1053
1054=item *
1055
0cc8c746
S
1056L<Test::Harness> has been upgraded from version 3.36 to 3.38.
1057
1058=item *
1059
1060L<Test::Simple> has been upgraded from version 1.001014 to 1.302073.
1061
1062=item *
1063
1064L<Thread::Queue> has been upgraded from version 3.09 to 3.12.
1065
1066=item *
1067
2c8edc25
S
1068L<Thread::Semaphore> has been upgraded from 2.12 to 2.13.
1069
1070Added the C<down_timed> method.
1071
1072=item *
1073
0cc8c746 1074L<threads> has been upgraded from version 2.07 to 2.15.
2c8edc25 1075
2c8edc25
S
1076=item *
1077
0cc8c746 1078L<threads::shared> has been upgraded from version 1.51 to 1.56.
2c8edc25 1079
2c8edc25
S
1080=item *
1081
0cc8c746
S
1082L<Tie::Hash::NamedCapture> has been upgraded from version 0.09 to 0.10.
1083
1084=item *
1085
1086L<Time::HiRes> has been upgraded from version 1.9733 to 1.9741.
2c8edc25
S
1087
1088It now builds on systems with C++11 compilers (such as G++ 6 and Clang++
10893.9).
1090
1091Now uses C<clockid_t>.
1092
1093=item *
1094
0cc8c746
S
1095L<Time::Local> has been upgraded from version 1.2300 to 1.25.
1096
1097=item *
1098
1099L<Unicode::Collate> has been upgraded from version 1.14 to 1.19.
1100
1101=item *
1102
1103L<Unicode::UCD> has been upgraded from version 0.64 to 0.68.
2c8edc25 1104
a3a9a3d2
KW
1105It now uses 3-arg C<open()> instead of 2-arg C<open()>.
1106L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
2c8edc25
S
1107
1108=item *
1109
0cc8c746
S
1110L<version> has been upgraded from version 0.9916 to 0.9917.
1111
1112=item *
1113
1114L<VMS::DCLsym> has been upgraded from version 1.06 to 1.08.
2c8edc25 1115
a3a9a3d2
KW
1116It now uses 3-arg C<open()> instead of 2-arg C<open()>.
1117L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
a049258c
S
1118
1119=item *
1120
0cc8c746
S
1121L<warnings> has been upgraded from version 1.36 to 1.37.
1122
1123=item *
1124
1125L<XS::Typemap> has been upgraded from version 0.14 to 0.15.
1126
1127=item *
1128
1129L<XSLoader> has been upgraded from version 0.21 to 0.27.
2c8edc25
S
1130
1131Fixed a security hole in which binary files could be loaded from a path
1132outside of L<C<@INC>|perlvar/@INC>.
1133
a3a9a3d2
KW
1134It now uses 3-arg C<open()> instead of 2-arg C<open()>.
1135L<[perl #130122]|https://rt.perl.org/Public/Bug/Display.html?id=130122>
a049258c
S
1136
1137=back
1138
2c8edc25
S
1139=head1 Documentation
1140
1141=head2 New Documentation
a049258c 1142
2c8edc25 1143=head3 L<perldeprecation>
a049258c 1144
2c8edc25 1145This file documents all upcoming deprecations, and some of the deprecations
95b17558 1146which already have been removed. The purpose of this documentation is
2c8edc25
S
1147two-fold: document what will disappear, and by which version, and serve
1148as a guide for people dealing with code which has features that no longer
1149work after an upgrade of their perl.
a049258c 1150
2c8edc25 1151=head2 Changes to Existing Documentation
a049258c 1152
b10de59c
KW
1153We have attempted to update the documentation to reflect the changes
1154listed in this document. If you find any we have missed, send email to
bfe8fcbb 1155L<perlbug@perl.org|mailto:perlbug@perl.org>.
a049258c 1156
b10de59c
KW
1157Additionally all references to Usenet have been removed, and the
1158following selected changes have been made:
2c8edc25 1159
b10de59c 1160=head3 L<perlfunc>
a049258c 1161
b10de59c 1162=over 4
a049258c 1163
2c8edc25
S
1164=item *
1165
b10de59c
KW
1166Removed obsolete text about L<C<defined()>|perlfunc/defined>
1167on aggregates that should have been deleted earlier, when the feature
1168was removed.
2c8edc25
S
1169
1170=item *
1171
b10de59c
KW
1172Corrected documentation of L<C<eval()>|perlfunc/eval>,
1173and L<C<evalbytes()>|perlfunc/evalbytes>.
a049258c 1174
2c8edc25 1175=item *
a049258c 1176
b10de59c
KW
1177Clarified documentation of L<C<seek()>|perlfunc/seek>,
1178L<C<tell()>|perlfunc/tell> and L<C<sysseek()>|perlfunc/sysseek>
f9b6dffc 1179emphasizing that positions are in bytes and not characters.
b10de59c 1180L<[perl #128607]|https://rt.perl.org/Public/Bug/Display.html?id=128607>
2c8edc25
S
1181
1182=item *
1183
b10de59c
KW
1184Clarified documentation of L<C<sort()>|perlfunc/sort LIST> concerning
1185the variables C<$a> and C<$b>.
2c8edc25
S
1186
1187=item *
a049258c 1188
de7be789
KW
1189In L<C<split()>|perlfunc/split> noted that certain pattern modifiers are
1190legal, and added a caution about its use in Perls before v5.11,
a049258c 1191
2c8edc25 1192=item *
a049258c 1193
b10de59c
KW
1194Removed obsolete documentation of L<C<study()>|perlfunc/study>, noting
1195that it is now a no-op.
2c8edc25
S
1196
1197=item *
1198
b10de59c
KW
1199Noted that L<C<vec()>|perlfunc/vec> doesn't work well when the string
1200contains characters whose code points are above 255.
a049258c 1201
2c8edc25 1202=back
a049258c 1203
b10de59c 1204=head3 L<perlguts>
a049258c
S
1205
1206=over 4
1207
1208=item *
1209
b10de59c
KW
1210Added advice on
1211L<formatted printing of operands of C<Size_t> and C<SSize_t>|perlguts/Formatted Printing of Size_t and SSize_t>
a049258c
S
1212
1213=back
1214
b10de59c 1215=head3 L<perlhack>
2c8edc25
S
1216
1217=over 4
1218
1219=item *
1220
7964b3a0
KW
1221Clarify what editor tab stop rules to use, and note that we are
1222migrating away from using tabs, replacing them with sequences of SPACE
1223characters.
2c8edc25
S
1224
1225=back
a049258c 1226
b10de59c 1227=head3 L<perlhacktips>
a049258c
S
1228
1229=over 4
1230
1231=item *
1232
b10de59c 1233Give another reason to use C<cBOOL> to cast an expression to boolean.
2c8edc25
S
1234
1235=item *
1236
b10de59c
KW
1237Note that there are macros C<TRUE> and C<FALSE> available to express
1238boolean values.
a049258c 1239
2c8edc25 1240=back
a049258c 1241
2c8edc25 1242=head3 L<perlinterp>
a049258c
S
1243
1244=over 4
1245
1246=item *
1247
2c8edc25
S
1248L<perlinterp> has been expanded to give a more detailed example of how to
1249hunt around in the parser for how a given operator is handled.
a049258c
S
1250
1251=back
1252
2c8edc25 1253=head3 L<perllocale>
a049258c
S
1254
1255=over 4
1256
a6733086
S
1257=item *
1258
b10de59c
KW
1259Some locales aren't compatible with Perl. Note that these can cause
1260core dumps.
a049258c
S
1261
1262=back
1263
15a20477 1264=head3 L<perlmod>
2c8edc25
S
1265
1266=over 4
1267
1268=item *
1269
b10de59c 1270Various clarifications have been added.
2c8edc25
S
1271
1272=back
1273
1274=head3 L<perlmodlib>
1275
1276=over 4
1277
1278=item *
1279
b10de59c 1280Updated the site mirror list.
2c8edc25
S
1281
1282=back
1283
1284=head3 L<perlobj>
1285
1286=over 4
1287
1288=item *
1289
1290Added a section on calling methods using their fully qualified names.
1291
1292=item *
1293
0f032fe1 1294Do not discourage manual C<@ISA>.
2c8edc25
S
1295
1296=back
1297
1298=head3 L<perlootut>
1299
1300=over 4
1301
1302=item *
1303
2c8edc25
S
1304Mention C<Moo> more.
1305
1306=back
1307
1308=head3 L<perlop>
1309
1310=over 4
1311
1312=item *
1313
b072a8ef
KW
1314Note that white space must be used for quoting operators if the
1315delimiter is a word character (I<i.e.>, matches C<\w>).
1316
1317=item *
1318
1319Clarify that in regular expression patterns delimited by single quotes,
1320no variable interpolation is done.
2c8edc25
S
1321
1322=back
1323
1324=head3 L<perlre>
1325
1326=over 4
1327
1328=item *
1329
1c34b59a
KW
1330The first part was extensively rewritten to incorporate various basic
1331points, that in earlier versions were mentioned in sort of an appendix
1332on Version 8 regular expressions.
1333
0cbd1ffa
KW
1334=item *
1335
b10de59c
KW
1336Note that it is common to have the C</x> modifier and forget that this
1337means that C<"#"> has to be escaped.
2c8edc25
S
1338
1339=back
1340
b10de59c 1341=head3 L<perlretut>
2c8edc25
S
1342
1343=over 4
1344
1345=item *
1346
b10de59c 1347Add introductory material
2c8edc25
S
1348
1349=item *
1350
b10de59c
KW
1351Note that a metacharacter occurring in a context where it can't mean
1352that, silently loses its meta-ness and matches literally.
1353L<C<use re 'strict'>|re/'strict' mode> can catch some of these.
2c8edc25
S
1354
1355=back
1356
1357=head3 L<perlunicode>
1358
1359=over 4
1360
1361=item *
1362
b10de59c 1363Corrected the text about Unicode BYTE ORDER MARK handling.
2c8edc25
S
1364
1365=item *
1366
1367Updated the text to correspond with changes in Unicode UTS#18, concerning
1368regular expressions, and Perl compatibility with what it says.
1369
1370=back
1371
1372=head3 L<perlvar>
1373
1374=over 4
1375
1376=item *
1377
95b17558 1378Document C<@ISA>. Was documented other places, not not in L<perlvar>.
2c8edc25
S
1379
1380=back
1381
1382=head1 Diagnostics
1383
1384=head2 New Diagnostics
1385
1386=head3 New Errors
1387
1388=over 4
1389
1390=item *
1391
6ebc3119
KW
1392L<A signature parameter must start with C<'$'>, C<'@'> or C<'%'>
1393|perldiag/A signature parameter must start with C<'$'>, C<'@'> or C<'%'>>
1394
1395=item *
1396
25d191b5 1397L<Bareword in require contains "%s"|perldiag/"Bareword in require contains "%s"">
2c8edc25
S
1398
1399=item *
1400
25d191b5 1401L<Bareword in require maps to empty filename|perldiag/"Bareword in require maps to empty filename">
2c8edc25
S
1402
1403=item *
1404
25d191b5 1405L<Bareword in require maps to disallowed filename "%s"|perldiag/"Bareword in require maps to disallowed filename "%s"">
473ac7a0 1406
2c8edc25
S
1407=item *
1408
25d191b5 1409L<Bareword in require must not start with a double-colon: "%s"|perldiag/"Bareword in require must not start with a double-colon: "%s"">
2c8edc25
S
1410
1411=item *
1412
1413L<%s: command not found|perldiag/"%s: command not found">
1414
1415(A) You've accidentally run your script through B<bash> or another shell
068a1201
KW
1416instead of Perl. Check the C<#!> line, or manually feed your script into
1417Perl yourself. The C<#!> line at the top of your file could look like:
2c8edc25
S
1418
1419 #!/usr/bin/perl
1420
1421=item *
1422
1423L<%s: command not found: %s|perldiag/"%s: command not found: %s">
1424
1425(A) You've accidentally run your script through B<zsh> or another shell
068a1201
KW
1426instead of Perl. Check the C<#!> line, or manually feed your script into
1427Perl yourself. The C<#!> line at the top of your file could look like:
2c8edc25
S
1428
1429 #!/usr/bin/perl
1430
1431=item *
1432
25d191b5 1433L<The experimental declared_refs feature is not enabled|perldiag/"The experimental declared_refs feature is not enabled">
2c8edc25 1434
25d191b5
KW
1435(F) To declare references to variables, as in C<my \%x>, you must first enable
1436the feature:
2c8edc25 1437
25d191b5
KW
1438 no warnings "experimental::declared_refs";
1439 use feature "declared_refs";
2c8edc25 1440
25d191b5 1441See L</Declaring a reference to a variable>.
2c8edc25
S
1442
1443=item *
1444
6ebc3119
KW
1445L<Illegal character following sigil in a subroutine signature
1446|perldiag/Illegal character following sigil in a subroutine signature>
1447
1448=item *
1449
1450L<Indentation on line %d of here-doc doesn't match delimiter
1451|perldiag/Indentation on line %d of here-doc doesn't match delimiter>
1452
1453=item *
1454
25d191b5
KW
1455L<Infinite recursion in regex|perldiag/"Infinite recursion in regex">.
1456
1457Using the empty pattern (which re-executes the last successfully-matched
1458pattern) inside a code block in another regex, as in C</(?{ s!!new! })/>, has
1459always previously yielded a segfault. It now produces this error.
2c8edc25
S
1460
1461=item *
1462
6ebc3119
KW
1463L<Malformed UTF-8 string in "%s"
1464|perldiag/Malformed UTF-8 string in "%s">
1465
1466=item *
1467
1468L<Multiple slurpy parameters not allowed
1469|perldiag/Multiple slurpy parameters not allowed>
1470
1471=item *
1472
1473L<C<'#'> not allowed immediately following a sigil in a subroutine signature
1474|perldiag/C<'#'> not allowed immediately following a sigil in a subroutine signature>
1475
1476=item *
1477
1478L<panic: unknown OA_*: %x
1479|perldiag/panic: unknown OA_*: %x>
1480
1481=item *
1482
1483L<The %s function is unimplemented
1484|perldiag/The %s function is unimplemented>
1485
1486=item *
1487
25d191b5
KW
1488L<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>>
1489
1490Unescaped left braces are now illegal in some contexts in regular expression
1491patterns. In other contexts, they are still just deprecated; they will
1492be illegal in Perl 5.30.
2c8edc25
S
1493
1494=item *
1495
25d191b5
KW
1496L<Version control conflict marker|perldiag/"Version control conflict marker">
1497
1498(F) The parser found a line starting with C<E<lt>E<lt>E<lt>E<lt>E<lt>E<lt>E<lt>>,
1499C<E<gt>E<gt>E<gt>E<gt>E<gt>E<gt>E<gt>>, or C<=======>. These may be left by a
1500version control system to mark conflicts after a failed merge operation.
2c8edc25
S
1501
1502=back
1503
1504=head3 New Warnings
1505
1506=over 4
1507
1508=item *
1509
6ebc3119
KW
1510L<Can't determine class of operator %s, assuming C<BASEOP>
1511|perldiag/Can't determine class of operator %s, assuming C<BASEOP>>
1512
1513=item *
1514
2c8edc25
S
1515L<Declaring references is experimental|perldiag/"Declaring references is experimental">
1516
1517(S experimental::declared_refs) This warning is emitted if you use a reference
1518constructor on the right-hand side of C<my()>, C<state()>, C<our()>, or
1519C<local()>. Simply suppress the warning if you want to use the feature, but
1520know that in doing so you are taking the risk of using an experimental feature
1521which may change or be removed in a future Perl version:
1522
1523 no warnings "experimental::declared_refs";
1524 use feature "declared_refs";
1525 $fooref = my \$foo;
1526
473ac7a0
KW
1527See L</Declaring a reference to a variable>.
1528
2c8edc25
S
1529=item *
1530
ef94516c
KW
1531L<do "%s" failed, '.' is no longer in @INC|perldiag/do "%s" failed, '.' is no longer in @INC; did you mean do ".E<sol>%s"?>
1532
1533Since C<"."> is now removed from C<@INC> by default, C<do> will now trigger a warning recommending to fix the C<do> statement.
1534
1535=item *
1536
4f73c567 1537L<C<${^ENCODING}> is no longer supported. Its use will be fatal in Perl 5.28|perldiag/"${^ENCODING} is no longer supported. Its use will be fatal in Perl 5.28">
2c8edc25 1538
0f275d26 1539The special variable C<${^ENCODING}>, formerly used to implement
53799a91 1540the C<encoding> pragma, is no longer supported as of Perl 5.26.
2c8edc25 1541
89853d76
DH
1542=item *
1543
6ebc3119
KW
1544L<Unescaped literal '%c' in regex; marked by <-- HERE in mE<sol>%sE<sol>
1545|perldiag/Unescaped literal '%c' in regex; marked by <-- HERE in mE<sol>%sE<sol>>
1546
1547=item *
1548
ef94516c 1549L<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">
89853d76 1550
ef94516c 1551See L</Deprecations>
89853d76 1552
2c8edc25
S
1553=back
1554
1555=head2 Changes to Existing Diagnostics
1556
1557=over 4
1558
1559=item *
1560
1561When a C<require> fails, we now do not provide C<@INC> when the C<require>
1562is for a file instead of a module.
1563
1564=item *
1565
1566When C<@INC> is not scanned for a C<require> call, we no longer display
1567C<@INC> to avoid confusion.
1568
1569=item *
1570
cf3a543f
KW
1571L<Attribute "locked" is deprecated, and will disappear in Perl 5.28
1572|perldiag/Attribute "locked" is deprecated, and will disappear in Perl 5.28>
2c8edc25
S
1573
1574=item *
1575
cf3a543f
KW
1576L<Attribute "unique" is deprecated, and will disappear in Perl 5.28
1577|perldiag/Attribute "unique" is deprecated, and will disappear in Perl 5.28>
2c8edc25
S
1578
1579=item *
1580
cf3a543f
KW
1581L<Constants from lexical variables potentially modified elsewhere are deprecated. This will not be allowed in Perl 5.32
1582|perldiag/Constants from lexical variables potentially modified elsewhere are deprecated. This will not be allowed in Perl 5.32>
2c8edc25
S
1583
1584=item *
1585
cf3a543f
KW
1586L<Deprecated use of C<my()> in false conditional. This will be a fatal error in Perl 5.30
1587|perldiag/Deprecated use of C<my()> in false conditional. This will be a fatal error in Perl 5.30>
2c8edc25
S
1588
1589=item *
1590
cf3a543f
KW
1591L<C<dump()> better written as C<CORE::dump()>. C<dump()> will no longer be available in Perl 5.30
1592|perldiag/C<dump()> better written as C<CORE::dump()>. C<dump()> will no longer be available in Perl 5.30>
2c8edc25
S
1593
1594=item *
1595
cf3a543f
KW
1596L<C<${^ENCODING}> is no longer supported. Its use will be fatal in Perl 5.28
1597|perldiag/C<${^ENCODING}> is no longer supported. Its use will be fatal in Perl 5.28>
2c8edc25
S
1598
1599=item *
1600
a3a9a3d2
KW
1601L<Experimental %s on scalar is now forbidden This message now is followed by more helpful text.
1602L<[perl #127976]|https://rt.perl.org/Public/Bug/Display.html?id=127976>
cf3a543f 1603|perldiag/Experimental %s on scalar is now forbidden>.
29480ba4 1604
a3a9a3d2
KW
1605This message now is followed by more helpful text.
1606L<[perl #127976]|https://rt.perl.org/Public/Bug/Display.html?id=127976>
906e28fb
KW
1607
1608=item *
1609
cf3a543f
KW
1610L<C<File::Glob::glob()> will disappear in perl 5.30. Use C<File::Glob::bsd_glob()> instead.
1611|perldiag/C<File::Glob::glob()> will disappear in perl 5.30. Use C<File::Glob::bsd_glob()> instead.>
2c8edc25
S
1612
1613=item *
1614
cf3a543f
KW
1615L<%s() is deprecated on C<:utf8> handles. This will be a fatal error in Perl 5.30
1616|perldiag/%s() is deprecated on C<:utf8> handles. This will be a fatal error in Perl 5.30>.
2c8edc25 1617
29480ba4 1618"%s" is one of C<sysread>, C<recv>, C<syswrite>, or C<send>.
3c6ddc9f
TC
1619This warning is now enabled by default, as all C<deprecated> category
1620warnings should be.
1621
2c8edc25
S
1622=item *
1623
cf3a543f
KW
1624L<C<$*> is no longer supported. Its use will be fatal in Perl 5.30
1625|perldiag/C<$*> is no longer supported. Its use will be fatal in Perl 5.30>
2c8edc25
S
1626
1627=item *
1628
6ebc3119
KW
1629L<C<$#> is no longer supported. Its use will be fatal in Perl 5.30
1630|perldiag/C<$#> is no longer supported. Its use will be fatal in Perl 5.30>
1631
1632=item *
1633
a72cf578
KW
1634L<Malformed UTF-8 character%s
1635|perldiag/Malformed UTF-8 character%s>
1636
1637Details as to the exact problem have been added at the end of this
1638message
1639
1640=item *
1641
cf3a543f
KW
1642L<Opening dirhandle %s also as a file. This will be a fatal error in Perl 5.28
1643|perldiag/Opening dirhandle %s also as a file. This will be a fatal error in Perl 5.28>
2c8edc25
S
1644
1645=item *
1646
cf3a543f
KW
1647L<Opening filehandle %s also as a directory. This will be a fatal error in Perl 5.28
1648|perldiag/Opening filehandle %s also as a directory. This will be a fatal error in Perl 5.28>
2c8edc25
S
1649
1650=item *
1651
cf3a543f
KW
1652L<Setting C<$/> to a reference to %s as a form of slurp is deprecated, treating as undef. This will be fatal in Perl 5.28
1653|perldiag/Setting C<$/> 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
1654
1655=item *
1656
cf3a543f
KW
1657L<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>
1658|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
1659
1660=item *
1661
cf3a543f
KW
1662L<Unknown charname '' is deprecated. Its use will be fatal in Perl 5.28
1663|perldiag/Unknown charname '' is deprecated. Its use will be fatal in Perl 5.28>
2c8edc25
S
1664
1665=item *
1666
cf3a543f
KW
1667L<Use of bare E<lt>E<lt> to mean E<lt>E<lt>"" is deprecated. Its use will be fatal in Perl 5.28
1668|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
1669
1670=item *
1671
cf3a543f
KW
1672L<Use of code point 0x%s is deprecated; the permissible max is 0x%s. This will be fatal in Perl 5.28
1673|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
1674
1675=item *
1676
cf3a543f
KW
1677L<Use of comma-less variable list is deprecated. Its use will be fatal in Perl 5.28
1678|perldiag/Use of comma-less variable list is deprecated. Its use will be fatal in Perl 5.28>
2c8edc25
S
1679
1680=item *
1681
cf3a543f
KW
1682L<Use of inherited C<AUTOLOAD> for non-method %s() is deprecated. This will be fatal in Perl 5.28
1683|perldiag/Use of inherited C<AUTOLOAD> for non-method %s() is deprecated. This will be fatal in Perl 5.28>
2c8edc25
S
1684
1685=item *
1686
cf3a543f
KW
1687L<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
1688|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 1689
2c8edc25
S
1690=back
1691
1692=head1 Utility Changes
1693
1694=head2 F<c2ph> and F<pstruct>
1695
1696=over 4
1697
1698=item *
1699
1700These old utilities have long since superceded by L<h2xs>, and are
1701now gone from the distribution.
1702
1703=back
1704
1705=head2 F<Porting/pod_lib.pl>
1706
1707=over 4
1708
1709=item *
1710
1711Removed spurious executable bit.
1712
1713=item *
1714
fb5d4b1a 1715Account for the possibility of DOS file endings.
2c8edc25
S
1716
1717=back
1718
1719=head2 F<Porting/sync-with-cpan>
1720
1721=over 4
1722
1723=item *
1724
1725Many improvements
1726
1727=back
1728
1729=head2 F<perf/benchmarks>
1730
1731=over 4
1732
1733=item *
1734
1735Tidy file, rename some symbols.
1736
1737=back
1738
1739=head2 F<Porting/checkAUTHORS.pl>
1740
1741=over 4
1742
1743=item *
1744
0f275d26 1745Replace obscure character range with C<\w>.
2c8edc25
S
1746
1747=back
1748
1749=head2 F<t/porting/regen.t>
1750
1751=over 4
1752
1753=item *
1754
1755try to be more helpful when tests fail.
1756
1757=back
1758
1759=head2 F<utils/h2xs.PL>
1760
1761=over 4
1762
1763=item *
1764
1765Avoid infinite loop for enums.
1766
1767=back
1768
1769=head2 L<perlbug>
1770
1771=over 4
1772
1773=item *
1774
1775Long lines in the message body are now wrapped at 900 characters, to stay
1776well within the 1000-character limit imposed by SMTP mail transfer agents.
1777This is particularly likely to be important for the list of arguments to
1778C<Configure>, which can readily exceed the limit if, for example, it names
95b17558 1779several non-default installation paths. This change also adds the first unit
a3a9a3d2
KW
1780tests for perlbug.
1781L<[perl #128020]|https://rt.perl.org/Public/Bug/Display.html?id=128020>
2c8edc25
S
1782
1783=back
1784
1785=head1 Configuration and Compilation
1786
1787=over 4
1788
1789=item *
1790
89853d76 1791C<-Ddefault_inc_excludes_dot> has been turned on by default.
2c8edc25
S
1792
1793=item *
1794
a3a9a3d2
KW
1795The C<dtrace> build process has further changes
1796L<[perl #130108]|https://rt.perl.org/Public/Bug/Display.html?id=130108>:
2c8edc25
S
1797
1798=over
1799
1800=item *
1801
1802If the C<-xnolibs> is available, use that so a F<dtrace> perl can be
1803built within a FreeBSD jail.
1804
1805=item *
1806
1807On systems that build a dtrace object file (FreeBSD, Solaris and
1808SystemTap's dtrace emulation), copy the input objects to a separate
1809directory and process them there, and use those objects in the link,
1810since C<dtrace -G> also modifies these objects.
1811
1812=item *
1813
1814Add libelf to the build on FreeBSD 10.x, since dtrace adds references
1815to libelf symbols.
1816
1817=item *
1818
1819Generate a dummy dtrace_main.o if C<dtrace -G> fails to build it. A
1820default build on Solaris generates probes from the unused inline
1821functions, while they don't on FreeBSD, which causes C<dtrace -G> to
1822fail.
1823
1824=back
1825
2c8edc25
S
1826=item *
1827
0f032fe1
KW
1828You can now disable perl's use of the C<PERL_HASH_SEED> and
1829C<PERL_PERTURB_KEYS> environment variables by configuring perl with
2c8edc25
S
1830C<-Accflags=NO_PERL_HASH_ENV>.
1831
1832=item *
1833
0f032fe1 1834You can now disable perl's use of the C<PERL_HASH_SEED_DEBUG> environment
2c8edc25
S
1835variable by configuring perl with
1836C<-Accflags=-DNO_PERL_HASH_SEED_DEBUG>.
1837
1838=item *
1839
1840Zero out the alignment bytes when calculating the bytes for 80-bit C<NaN>
a3a9a3d2
KW
1841and C<Inf> to make builds more reproducible.
1842L<[perl #130133]|https://rt.perl.org/Public/Bug/Display.html?id=130133>
2c8edc25
S
1843
1844=item *
1845
fb5d4b1a 1846Since v5.18 for testing purposes, we have included support for
2c8edc25 1847building perl with a variety of non-standard, and non-recommended
95b17558
KW
1848hash functions. Since we do not recommend the use of these functions
1849we have removed them and their corresponding build options. Specifically
2c8edc25
S
1850this includes the following build options:
1851
1852 PERL_HASH_FUNC_SDBM
1853 PERL_HASH_FUNC_DJB2
1854 PERL_HASH_FUNC_SUPERFAST
1855 PERL_HASH_FUNC_MURMUR3
1856 PERL_HASH_FUNC_ONE_AT_A_TIME
1857 PERL_HASH_FUNC_ONE_AT_A_TIME_OLD
1858 PERL_HASH_FUNC_MURMUR_HASH_64A
1859 PERL_HASH_FUNC_MURMUR_HASH_64B
1860
1861=item *
1862
1863Remove "Warning: perl appears in your path"
1864
1865This install warning is more or less obsolete, since most platforms already
0f032fe1 1866B<will> have a F</usr/bin/perl> or similar provided by the OS.
2c8edc25
S
1867
1868=item *
1869
0f032fe1 1870Reduce verbosity of C<make install.man>
2c8edc25
S
1871
1872Previously, two progress messages were emitted for each manpage: one by
1873installman itself, and one by the function in install_lib.pl that it calls to
95b17558 1874actually install the file. Disabling the second of those in each case saves
2c8edc25
S
1875over 750 lines of unhelpful output.
1876
1877=item *
1878
a3a9a3d2
KW
1879Cleanup for C<clang -Weverything> support.
1880L<[perl #129961]|https://rt.perl.org/Public/Bug/Display.html?id=129961>
2c8edc25
S
1881
1882=item *
1883
1884Configure: signbit scan was assuming too much, stop assuming negative 0.
1885
1886=item *
1887
1888Various compiler warnings have been silenced.
1889
1890=item *
1891
1892Several smaller changes have been made to remove impediments to compiling under
1893C++11.
1894
1895=item *
1896
1897Builds using C<USE_PAD_RESET> now work again; this configuration had
1898bit-rotted.
1899
1900=item *
1901
1902A probe for C<gai_strerror> was added to F<Configure> that checks if the
0f032fe1
KW
1903the C<gai_strerror()> routine is available and can be used to
1904translate error codes returned by C<getaddrinfo()> into human
2c8edc25
S
1905readable strings.
1906
1907=item *
1908
0f032fe1 1909F<Configure> now aborts if both C<-Duselongdouble> and C<-Dusequadmath> are
2c8edc25
S
1910requested.
1911L<[perl #126203]|https://rt.perl.org/Public/Bug/Display.html?id=126203>
1912
1913=item *
1914
0f032fe1 1915Fixed a bug in which F<Configure> could append C<-quadmath> to the archname even
2c8edc25
S
1916if it was already present.
1917L<[perl #128538]|https://rt.perl.org/Public/Bug/Display.html?id=128538>
1918
1919=item *
1920
0f032fe1
KW
1921Clang builds with C<-DPERL_GLOBAL_STRUCT> or
1922C<-DPERL_GLOBAL_STRUCT_PRIVATE> have
2c8edc25
S
1923been fixed (by disabling Thread Safety Analysis for these configurations).
1924
1925=item *
1926
1927F<make_ext.pl> no longer updates a module's F<pm_to_blib> file when no
1928files require updates. This could cause dependencies, F<perlmain.c>
a3a9a3d2
KW
1929in particular, to be rebuilt unnecessarily.
1930L<[perl #126710]|https://rt.perl.org/Public/Bug/Display.html?id=126710>
2c8edc25
S
1931
1932=item *
1933
1934The output of C<perl -V> has been reformatted so that each configuration
1935and compile-time option is now listed one per line, to improve
1936readability.
1937
1938=item *
1939
1940C<Configure> now builds C<miniperl> and C<generate_uudmap> if you
1941invoke it with C<-Dusecrosscompiler> but not C<-Dtargethost=somehost>.
1942This means you can supply your target platform C<config.sh>, generate
a3a9a3d2
KW
1943the headers and proceed to build your cross-target perl.
1944L<[perl #127234]|https://rt.perl.org/Public/Bug/Display.html?id=127234>
2c8edc25
S
1945
1946=item *
1947
1948Builds with C<-Accflags=-DPERL_TRACE_OPS> now only dump the operator
1949counts when the environment variable C<PERL_TRACE_OPS> to be set to a
1950non-zero integer. This allows C<make test> to pass on such a build.
1951
1952=item *
1953
1954When building with GCC 6 and link-time optimization (the C<-flto> option to
1955C<gcc>), C<Configure> was treating all probed symbols as present on the
95b17558 1956system, regardless of whether they actually exist. This has been fixed.
a3a9a3d2 1957L<[perl #128131]|https://rt.perl.org/Public/Bug/Display.html?id=128131>
2c8edc25
S
1958
1959=item *
1960
1961The F<t/test.pl> library is used for internal testing of Perl itself, and
95b17558 1962also copied by several CPAN modules. Some of those modules must work on
2c8edc25 1963older versions of Perl, so F<t/test.pl> must in turn avoid newer Perl
95b17558 1964features. Compatibility with Perl 5.8 was inadvertently removed some time
a3a9a3d2
KW
1965ago; it has now been restored.
1966L<[perl #128052]|https://rt.perl.org/Public/Bug/Display.html?id=128052>
2c8edc25
S
1967
1968=item *
1969
1970The build process no longer emits an extra blank line before building each
1971"simple" extension (those with only F<*.pm> and F<*.pod> files).
1972
1973=back
1974
1975=head1 Testing
1976
dd84ba97
KW
1977Tests were added and changed to reflect the other additions and changes
1978in this release. In addition, these substantive changes were made:
1979
2c8edc25
S
1980=over 4
1981
1982=item *
1983
dd84ba97
KW
1984A new test script, F<comp/parser_run.t>, has been added to test
1985reads through invalid pointers.
2c8edc25
S
1986
1987=item *
1988
1989Tests for locales were erroneously using locales incompatible with Perl.
1990
1991=item *
1992
1993Some parts of the test suite that try to exhaustively test edge cases in the
1994regex implementation have been restricted to running for a maximum of five
95b17558 1995minutes. On slow systems they could otherwise take several hours, without
2c8edc25
S
1996significantly improving our understanding of the correctness of the code
1997under test.
1998
1999In addition, some of those test cases have been split into more files, to
2000allow them to be run in parallel on suitable systems.
2001
2002=item *
2003
2004A new internal facility allows analysing the time taken by the individual
2005tests in Perl's own test suite; see F<Porting/harness-timer-report.pl>.
2006
2007=item *
2008
2009F<t/re/regexp_nonull.t> has been added to test that the regular expression
2010engine can handle scalars that do not have a null byte just past the end of
2011the string.
2012
2013=item *
2014
0ebc1fcf
KW
2015A new test script, F<t/op/decl-refs.t>, has been added to test the new feature
2016L</Declaring a reference to a variable>.
2c8edc25
S
2017
2018=item *
2019
dd84ba97
KW
2020A new test script, F<t/re/keep_tabs.t> has been added to contain tests
2021where C<\t> characters should not be expanded into spaces.
2022
2023=item *
2024
2c8edc25
S
2025A new test script, F<t/re/anyof.t>, has been added to test that the ANYOF nodes
2026generated by bracketed character classes are as expected.
2027
2028=item *
2029
dd84ba97
KW
2030There is now more extensive testing of the Unicode-related API macros
2031and functions.
2032
2033=item *
2034
2035Several of the longer running API test files have been split into
2036multiple test files so that they can be run in parallel.
2037
2038=item *
2039
2c8edc25 2040F<t/harness> now tries really hard not to run tests outside of the Perl
a3a9a3d2
KW
2041source tree.
2042L<[perl #124050]|https://rt.perl.org/Public/Bug/Display.html?id=124050>
2c8edc25
S
2043
2044=back
2045
2046=head1 Platform Support
2047
2048=head2 New Platforms
2049
2050=over 4
2051
2052=item NetBSD/VAX
2053
2054Perl now compiles under NetBSD on VAX machines. However, it's not
2055possible for that platform to implement floating-point infinities and
2056NaNs compatibly with most modern systems, which implement the IEEE-754
2057floating point standard. The hexadecimal floating point (C<0x...p[+-]n>
2058literals, C<printf %a>) is not implemented, either.
2059The C<make test> passes 98% of tests.
2060
2061=over 4
2062
2063=item *
2064
2065Test fixes and minor updates.
2066
2067=item *
2068
2069Account for lack of C<inf>, C<nan>, and C<-0.0> support.
2070
2071=back
2072
2073=back
2074
2075=head2 Platform-Specific Notes
2076
2077=over 4
2078
2079=item Darwin
2080
0f032fe1
KW
2081don't treat C<-Dprefix=/usr> as special, instead require an extra option
2082C<-Ddarwin_distribution> to produce the same results.
2c8edc25
S
2083
2084=item POSIX
2085
2086Finish removing POSIX deprecated functions.
2087
2088=item OS X
2089
0f032fe1
KW
2090OS X El Capitan doesn't implement the C<clock_gettime()> or
2091C<clock_getres()> APIs; emulate them as necessary.
2c8edc25
S
2092
2093=item macOS
2094
0f032fe1 2095Deprecated C<syscall(2)> on macOS 10.12.
2c8edc25
S
2096
2097=item EBCDIC
2098
2099Several tests have been updated to work (or be skipped) on EBCDIC platforms.
2100
2101=item HP-UX
2102
2103L<Net::Ping> UDP test is skipped on HP-UX.
2104
2105=item Hurd
2106
2107The hints for Hurd have been improved enabling malloc wrap and reporting the
2108GNU libc used (previously it was an empty string when reported).
2109
2110=item VAX
2111
29ce4d71 2112VAX floating point formats are now supported on NetBSD.
2c8edc25
S
2113
2114=item VMS
2115
2116=over 4
2117
2118=item *
2119
2120The path separator for the C<PERL5LIB> and C<PERLLIB> environment entries is
df48f9a4
KW
2121now a colon (C<":">) when running under a Unix shell. There is no change when
2122running under DCL (it's still C<"|">).
2c8edc25
S
2123
2124=item *
2125
29ce4d71
CB
2126C<configure.com> now recognizes the VSI-branded C compiler and no longer
2127recognizes the "DEC"-branded C compiler (as there hasn't been such a thing for
212815 or more years).
2c8edc25
S
2129
2130=back
2131
2132=item Windows
2133
2134=over 4
2135
2136=item *
2137
2138Support for compiling perl on Windows using Microsoft Visual Studio 2015
2139(containing Visual C++ 14.0) has been added.
2140
2141This version of VC++ includes a completely rewritten C run-time library, some
0f032fe1
KW
2142of the changes in which mean that work done to resolve a socket
2143C<close()> bug in
2c8edc25
S
2144perl #120091 and perl #118059 is not workable in its current state with this
2145version of VC++. Therefore, we have effectively reverted that bug fix for
2146VS2015 onwards on the basis that being able to build with VS2015 onwards is
2147more important than keeping the bug fix. We may revisit this in the future to
2148attempt to fix the bug again in a way that is compatible with VS2015.
2149
2150These changes do not affect compilation with GCC or with Visual Studio versions
fce64130 2151up to and including VS2013, I<i.e.>, the bug fix is retained (unchanged) for those
2c8edc25
S
2152compilers.
2153
2154Note that you may experience compatibility problems if you mix a perl built
2155with GCC or VS E<lt>= VS2013 with XS modules built with VS2015, or if you mix a
2156perl built with VS2015 with XS modules built with GCC or VS E<lt>= VS2013.
2157Some incompatibility may arise because of the bug fix that has been reverted
2158for VS2015 builds of perl, but there may well be incompatibility anyway because
fce64130 2159of the rewritten CRT in VS2015 (I<e.g.>, see discussion at
bdd37d82 2160L<http://stackoverflow.com/questions/30412951>).
2c8edc25
S
2161
2162=back
2163
2164=item Win32
2165
2166=over 4
2167
2168=item *
2169
95b17558 2170Tweaks for Win32 VC vs GCC detection makefile code. This fixes issue that CCHOME
2c8edc25 2171depends on CCTYPE, which in auto detect mode is set after CCHOME, so CCHOME uses
95b17558 2172the uninit CCTYPE var. Also fix else vs .ELSE in makefile.mk
2c8edc25
S
2173
2174=item *
2175
2176fp definitions have been updated.
2177
2178=back
2179
2c8edc25
S
2180=item Linux
2181
2182Drop support for Linux a.out Linux has used ELF for over twenty years.
2183
2184=item OpenBSD 6
2185
2186OpenBSD 6 still does not support returning pid, gid or uid with SA_SIGINFO.
2187Make sure this is accounted for.
2188
2189=item FreeBSD
2190
0f032fe1 2191F<t/uni/overload.t>: Skip hanging test on FreeBSD.
2c8edc25
S
2192
2193=back
2194
2195=head1 Internal Changes
2196
2197=over 4
2198
2199=item *
2200
0ebc1fcf
KW
2201A new API function L<C<sv_setpv_bufsize()>|perlapi/sv_setpv_bufsize>
2202allows simultaneously setting the
c2ef64b1
DM
2203length and allocated size of the buffer in an C<SV>, growing the buffer if
2204necessary.
2c8edc25
S
2205
2206=item *
2207
0ebc1fcf
KW
2208A new API macro L<C<SvPVCLEAR()>|perlapi/SvPVCLEAR> sets its C<SV>
2209argument to an empty string,
c2ef64b1 2210like Perl-space C<$x = ''>, but with several optimisations.
2c8edc25
S
2211
2212=item *
2213
c11f9206 2214Several new macros and functions for dealing with Unicode and
fb5d4b1a
KW
2215UTF-8-encoded strings have been added to the API, as well as some
2216changes in
c11f9206
DM
2217functionality of existing functions (see L<perlapi/Unicode Support> for
2218more details):
2219
2220=over
2221
2222=item *
2223
0ebc1fcf
KW
2224New versions of the API macros like C<isALPHA_utf8> and C<toLOWER_utf8>
2225have been added, each with the suffix C<_safe>, like
2226L<C<isSPACE_utf8_safe>|perlapi/isSPACE>. These take an extra
2227parameter, giving an upper
2228limit of how far into the string it is safe to read. Using the old
2229versions could cause attempts to read beyond the end of the input buffer
2230if the UTF-8 is not well-formed, and their use now raises a deprecation
2231warning. Details are at L<perlapi/Character classification>.
2c8edc25
S
2232
2233=item *
2234
0ebc1fcf
KW
2235Macros like L<C<isALPHA_utf8>|perlapi/isALPHA> and
2236L<C<toLOWER_utf8>|perlapi/toLOWER_utf8> now die if they detect
ac6c7175
KW
2237that their input UTF-8 is malformed. A deprecation warning had been
2238issued since Perl 5.18.
2c8edc25
S
2239
2240=item *
2241
c11f9206
DM
2242Several new macros for analysing the validity of utf8 sequences. These
2243are:
2244
bfe8fcbb
KW
2245L<C<UTF8_GOT_ABOVE_31_BIT>|perlapi/UTF8_GOT_ABOVE_31_BIT>
2246L<C<UTF8_GOT_CONTINUATION>|perlapi/UTF8_GOT_CONTINUATION>
2247L<C<UTF8_GOT_EMPTY>|perlapi/UTF8_GOT_EMPTY>
2248L<C<UTF8_GOT_LONG>|perlapi/UTF8_GOT_LONG>
2249L<C<UTF8_GOT_NONCHAR>|perlapi/UTF8_GOT_NONCHAR>
2250L<C<UTF8_GOT_NON_CONTINUATION>|perlapi/UTF8_GOT_NON_CONTINUATION>
2251L<C<UTF8_GOT_OVERFLOW>|perlapi/UTF8_GOT_OVERFLOW>
2252L<C<UTF8_GOT_SHORT>|perlapi/UTF8_GOT_SHORT>
2253L<C<UTF8_GOT_SUPER>|perlapi/UTF8_GOT_SUPER>
2254L<C<UTF8_GOT_SURROGATE>|perlapi/UTF8_GOT_SURROGATE>
2255L<C<UTF8_IS_INVARIANT>|perlapi/UTF8_IS_INVARIANT>
2256L<C<UTF8_IS_NONCHAR>|perlapi/UTF8_IS_NONCHAR>
2257L<C<UTF8_IS_SUPER>|perlapi/UTF8_IS_SUPER>
2258L<C<UTF8_IS_SURROGATE>|perlapi/UTF8_IS_SURROGATE>
2259L<C<UVCHR_IS_INVARIANT>|perlapi/UVCHR_IS_INVARIANT>
2260L<C<isUTF8_CHAR_flags>|perlapi/isUTF8_CHAR_flags>
2261L<C<isSTRICT_UTF8_CHAR>|perlapi/isSTRICT_UTF8_CHAR>
2262L<C<isC9_STRICT_UTF8_CHAR>|perlapi/isC9_STRICT_UTF8_CHAR>
2c8edc25
S
2263
2264=item *
2265
0f032fe1 2266Functions that are all extensions of the C<is_utf8_string_I<*>()> functions,
c11f9206
DM
2267that apply various restrictions to the UTF-8 recognized as valid:
2268
bfe8fcbb
KW
2269L<C<is_strict_utf8_string>|perlapi/is_strict_utf8_string>,
2270L<C<is_strict_utf8_string_loc>|perlapi/is_strict_utf8_string_loc>,
2271L<C<is_strict_utf8_string_loclen>|perlapi/is_strict_utf8_string_loclen>,
c11f9206 2272
bfe8fcbb
KW
2273L<C<is_c9strict_utf8_string>|perlapi/is_c9strict_utf8_string>,
2274L<C<is_c9strict_utf8_string_loc>|perlapi/is_c9strict_utf8_string_loc>,
2275L<C<is_c9strict_utf8_string_loclen>|perlapi/is_c9strict_utf8_string_loclen>,
c11f9206 2276
bfe8fcbb
KW
2277L<C<is_utf8_string_flags>|perlapi/is_utf8_string_flags>,
2278L<C<is_utf8_string_loc_flags>|perlapi/is_utf8_string_loc_flags>,
2279L<C<is_utf8_string_loclen_flags>|perlapi/is_utf8_string_loclen_flags>,
c11f9206 2280
bfe8fcbb
KW
2281L<C<is_utf8_fixed_width_buf_flags>|perlapi/is_utf8_fixed_width_buf_flags>,
2282L<C<is_utf8_fixed_width_buf_loc_flags>|perlapi/is_utf8_fixed_width_buf_loc_flags>,
2283L<C<is_utf8_fixed_width_buf_loclen_flags>|perlapi/is_utf8_fixed_width_buf_loclen_flags>.
c11f9206 2284
bfe8fcbb
KW
2285L<C<is_utf8_invariant_string>|perlapi/is_utf8_invariant_string>.
2286L<C<is_utf8_valid_partial_char>|perlapi/is_utf8_valid_partial_char>.
2287L<C<is_utf8_valid_partial_char_flags>|perlapi/is_utf8_valid_partial_char_flags>.
2c8edc25
S
2288
2289=item *
2290
bfe8fcbb
KW
2291The functions L<C<utf8n_to_uvchr>|perlapi/utf8n_to_uvchr> and its
2292derivatives have had several changes of behaviour.
c11f9206
DM
2293
2294Calling them, while passing a string length of 0 is now asserted against
2295in DEBUGGING builds, and otherwise returns the Unicode REPLACEMENT
2296CHARACTER. If you have nothing to decode, you shouldn't call the decode
2297function.
2298
2299They now return the Unicode REPLACEMENT CHARACTER if called with UTF-8
2300that has the overlong malformation, and that malformation is allowed by
2301the input parameters. This malformation is where the UTF-8 looks valid
2302syntactically, but there is a shorter sequence that yields the same code
2303point. This has been forbidden since Unicode version 3.1.
2304
2305They now accept an input
2c8edc25
S
2306flag to allow the overflow malformation. This malformation is when the
2307UTF-8 may be syntactically valid, but the code point it represents is
2308not capable of being represented in the word length on the platform.
2309What "allowed" means in this case is that the function doesn't return an
fb5d4b1a
KW
2310error, and it advances the parse pointer to beyond the UTF-8 in
2311question, but it returns the Unicode REPLACEMENT CHARACTER as the value
2312of the code point (since the real value is not representable).
2c8edc25 2313
55b0afa5
KW
2314They no longer abandon searching for other malformations when the first
2315one is encountered. A call to one of these functions thus can generate
2316multiple diagnostics, instead of just one.
2c8edc25
S
2317
2318=item *
2319
0ebc1fcf
KW
2320L<C<valid_utf8_to_uvchr()>|perlapi/valid_utf8_to_uvchr> has been added
2321to the API (although it was
c11f9206 2322present in core earlier). Like C<utf8_to_uvchr_buf()>, but assumes that
fb5d4b1a 2323the next character is well-formed. Use with caution.
c11f9206
DM
2324
2325=item *
2326
bfe8fcbb
KW
2327A new function, L<C<utf8n_to_uvchr_error>|perlapi/utf8n_to_uvchr_error>,
2328has been added for
2c8edc25
S
2329use by modules that need to know the details of UTF-8 malformations
2330beyond pass/fail. Previously, the only ways to know why a sequence was
2331ill-formed was to capture and parse the generated diagnostics, or to do
2332your own analysis.
2333
2334=item *
2335
0ebc1fcf
KW
2336There is now a safer version of utf8_hop(), called
2337L<C<utf8_hop_safe()>|perlapi/utf8_hop_safe>.
c11f9206
DM
2338Unlike utf8_hop(), utf8_hop_safe() won't navigate before the beginning or
2339after the end of the supplied buffer.
2c8edc25
S
2340
2341=item *
2342
0ebc1fcf
KW
2343Two new functions, L<C<utf8_hop_forward()>|perlapi/utf8_hop_forward> and
2344L<C<utf8_hop_back()>|perlapi/utf8_hop_back> are
c11f9206
DM
2345similar to C<utf8_hop_safe()> but are for when you know which direction
2346you wish to travel.
2c8edc25
S
2347
2348=item *
2349
c11f9206
DM
2350Two new macros which return useful utf8 byte sequences:
2351
bfe8fcbb
KW
2352L<C<BOM_UTF8>|perlapi/BOM_UTF8>
2353L<C<REPLACEMENT_CHARACTER_UTF8>|perlapi/REPLACEMENT_CHARACTER_UTF8>
c11f9206
DM
2354
2355=back
c2ef64b1
DM
2356
2357=item *
2358
2359Perl is now built with the C<PERL_OP_PARENT> compiler define enabled by
2360default. To disable it, use the C<PERL_NO_OP_PARENT> compiler define.
2361This flag alters how the C<op_sibling> field is used in C<OP> structures,
2362and has been available optionally since perl 5.22.
2363
2364See L<perl5220delta/"Internal Changes"> for more details of what this
2365build option does.
2366
2367=item *
2368
2369Three new ops, C<OP_ARGELEM>, C<OP_ARGDEFELEM> and C<OP_ARGCHECK> have
2370been added. These are intended principally to implement the individual
2371elements of a subroutine signature, plus any overall checking required.
2372
2373=item *
2374
96e0fd86
DM
2375The C<OP_PUSHRE> op has been eliminated and the C<OP_SPLIT> op has been
2376changed from class C<LISTOP> to C<PMOP>.
2377
2378Formerly the first child of a split would be a pushre, which would have the
2379split's regex attached to it. Now the regex is attached directly to the
2380split op, and the pushre has been eliminated.
2381
2382=item *
2383
0ebc1fcf
KW
2384The L<C<op_class()>|perlapi/op_class> API function has been added. This
2385is like the existing
c2ef64b1
DM
2386C<OP_CLASS()> macro, but can more accurately determine what struct an op
2387has been allocated as. For example C<OP_CLASS()> might return
2388C<OA_BASEOP_OR_UNOP> indicating that ops of this type are usually
2389allocated as an C<OP> or C<UNOP>; while C<op_class()> will return
2390C<OPclass_BASEOP> or C<OPclass_UNOP> as appropriate.
2c8edc25
S
2391
2392=item *
2393
2394All parts of the internals now agree that the C<sassign> op is a C<BINOP>;
2395previously it was listed as a C<BASEOP> in F<regen/opcodes>, which meant
2396that several parts of the internals had to be special-cased to accommodate
95b17558 2397it. This oddity's original motivation was to handle code like C<$x ||= 1>;
2c8edc25
S
2398that is now handled in a simpler way.
2399
2400=item *
2401
0ebc1fcf
KW
2402The output format of the L<C<op_dump()>|perlapi/op_dump> function (as
2403used by C<perl -Dx>)
c2ef64b1
DM
2404has changed: it now displays an "ASCII-art" tree structure, and shows more
2405low-level details about each op, such as its address and class.
2c8edc25
S
2406
2407=item *
2408
c2ef64b1
DM
2409The C<PADOFFSET> type has changed from being unsigned to signed, and
2410several pad-related variables such as C<PL_padix> have changed from being
2411of type C<I32> to type C<PADOFFSET>.
2c8edc25
S
2412
2413=item *
2414
c2ef64b1
DM
2415The C<DEBUGGING>-mode output for regex compilation and execution has been
2416enhanced.
2c8edc25
S
2417
2418=item *
2419
74ca8c9e
DM
2420Several obscure SV flags have been eliminated, sometimes along with the
2421macros which manipulate them: C<SVpbm_VALID>, C<SVpbm_TAIL>, C<SvTAIL_on>,
2422C<SvTAIL_off>, C<SVrepl_EVAL>, C<SvEVALED>
2c8edc25
S
2423
2424=item *
2425
74ca8c9e
DM
2426An OP op_private flag has been eliminated: C<OPpRUNTIME>. This used to
2427often get set on C<PMOP>s, but had become meaningless over time.
2c8edc25
S
2428
2429=back
2430
2431=head1 Selected Bug Fixes
2432
2433=over 4
2434
2435=item *
2436
5573eafe 2437Perl no longer panics when switching into some locales on machines with
a3a9a3d2
KW
2438buggy C<strxfrm()> implementations in their libc.
2439L<[perl #121734]|https://rt.perl.org/Public/Bug/Display.html?id=121734>
5573eafe
DM
2440
2441=item *
2442
2c8edc25
S
2443C< $-{$name} > would leak an C<AV> on each access if the regular
2444expression had no named captures. The same applies to access to any
2445hash tied with L<Tie::Hash::NamedCapture> and C<< all =E<gt> 1 >>. [perl
2446#130822]
2447
2448=item *
2449
2450Attempting to use the deprecated variable C<$#> as the object in an
2451indirect object method call could cause a heap use after free or
a3a9a3d2
KW
2452buffer overflow.
2453L<[perl #129274]|https://rt.perl.org/Public/Bug/Display.html?id=129274>
2c8edc25
S
2454
2455=item *
2456
2457When checking for an indirect object method call in some rare cases
2458the parser could reallocate the line buffer but then continue to use
a3a9a3d2
KW
2459pointers to the old buffer.
2460L<[perl #129190]|https://rt.perl.org/Public/Bug/Display.html?id=129190>
2c8edc25
S
2461
2462=item *
2463
0f032fe1
KW
2464Supplying a glob as the format argument to
2465L<C<formline>|perlfunc/formline> would
a3a9a3d2
KW
2466cause an assertion failure.
2467L<[perl #130722]|https://rt.perl.org/Public/Bug/Display.html?id=130722>
2c8edc25
S
2468
2469=item *
2470
2471Code like C< $value1 =~ qr/.../ ~~ $value2 > would have the match
0f032fe1 2472converted into a C<qr//> operator, leaving extra elements on the stack to
a3a9a3d2
KW
2473confuse any surrounding expression.
2474L<[perl #130705]|https://rt.perl.org/Public/Bug/Display.html?id=130705>
2c8edc25
S
2475
2476=item *
2477
d3972b39 2478Since v5.24 in some obscure cases, a regex which included code blocks
0f032fe1 2479from multiple sources (I<e.g.>, via embedded via C<qr//> objects) could end up
a3a9a3d2
KW
2480with the wrong current pad and crash or give weird results.
2481L<[perl #129881]|https://rt.perl.org/Public/Bug/Display.html?id=129881>
2c8edc25
S
2482
2483=item *
2484
2485Occasionally C<local()>s in a code block within a patterns weren't being
2486undone when the pattern matching backtracked over the code block.
a3a9a3d2 2487L<[perl #126697]|https://rt.perl.org/Public/Bug/Display.html?id=126697>
2c8edc25
S
2488
2489=item *
2490
2491Using C<substr()> to modify a magic variable could access freed memory
a3a9a3d2
KW
2492in some cases.
2493L<[perl #129340]|https://rt.perl.org/Public/Bug/Display.html?id=129340>
2c8edc25
S
2494
2495=item *
2496
2c8edc25 2497Under C<use utf8>, the entire Perl program is now checked that the UTF-8
a3a9a3d2
KW
2498is wellformed.
2499L<[perl #126310]|https://rt.perl.org/Public/Bug/Display.html?id=126310>.
2c8edc25
S
2500
2501=item *
2502
df48f9a4 2503The range operator C<".."> on strings now handles its arguments correctly when in
2c8edc25 2504the scope of the L<< C<unicode_strings>|feature/"The 'unicode_strings' feature" >>
95b17558 2505feature. The previous behaviour was sufficiently unexpected that we believe no
2c8edc25
S
2506correct program could have made use of it.
2507
2508=item *
2509
0f032fe1 2510The C<split> operator did not ensure enough space was allocated for
2c8edc25
S
2511its return value in scalar context. It could then write a single
2512pointer immediately beyond the end of the memory block allocated for
a3a9a3d2
KW
2513the stack.
2514L<[perl #130262]|https://rt.perl.org/Public/Bug/Display.html?id=130262>
2c8edc25
S
2515
2516=item *
2517
df48f9a4 2518Using a large code point with the C<"W"> pack template character with
2c8edc25
S
2519the current output position aligned at just the right point could
2520cause a write a single zero byte immediately beyond the end of an
a3a9a3d2
KW
2521allocated buffer.
2522L<[perl #129149]|https://rt.perl.org/Public/Bug/Display.html?id=129149>
2c8edc25
S
2523
2524=item *
2525
2526Supplying the form picture argument as part of the form argument list
2527where the picture specifies modifying the argument could cause an
a3a9a3d2
KW
2528access to the new freed compiled form.
2529L<[perl #129125]|https://rt.perl.org/Public/Bug/Display.html?id=129125>
2c8edc25
S
2530
2531=item *
2532
03c6d75f
TC
2533The L<sort()|perlfunc/sort> operator's built-in numeric comparison
2534function didn't handle large integers that weren't exactly
2535representable by a double. This now uses the same code used to
2536implement the C<< <=> >> operator.
a3a9a3d2 2537L<[perl #130335]|https://rt.perl.org/Public/Bug/Display.html?id=130335>
2c8edc25
S
2538
2539=item *
2540
0ebc1fcf 2541Fix issues with C</(?{ ... E<lt>E<lt>EOF })/> that broke
a3a9a3d2
KW
2542L<Method::Signatures>.
2543L<[perl #130398]|https://rt.perl.org/Public/Bug/Display.html?id=130398>
2c8edc25
S
2544
2545=item *
2546
a3a9a3d2
KW
2547Prevent tests from getting hung up on 'NonStop' option.
2548L<[perl #130445]|https://rt.perl.org/Public/Bug/Display.html?id=130445>
2c8edc25
S
2549
2550=item *
2551
2552Fixed an assertion failure with C<chop> and C<chomp>, which
a3a9a3d2
KW
2553could be triggered by C<chop(@x =~ tr/1/1/)>.
2554L<[perl #130198]|https://rt.perl.org/Public/Bug/Display.html?id=130198>.
2c8edc25
S
2555
2556=item *
2557
fb5d4b1a
KW
2558Fixed a comment skipping error in patterns under C</x>; it could stop
2559skipping a byte early, which could be in the middle of a UTF-8
a3a9a3d2
KW
2560character.
2561L<[perl #130495]|https://rt.perl.org/Public/Bug/Display.html?id=130495>.
2c8edc25
S
2562
2563=item *
2564
a3a9a3d2
KW
2565F<perldb> now ignores F</dev/tty> on non-Unix systems.
2566L<[perl #113960]|https://rt.perl.org/Public/Bug/Display.html?id=113960>;
2c8edc25
S
2567
2568=item *
2569
a3a9a3d2
KW
2570Fix assertion failure for C<{}-E<gt>$x> when C<$x> isn't defined.
2571L<[perl #130496]|https://rt.perl.org/Public/Bug/Display.html?id=130496>.
2c8edc25
S
2572
2573=item *
2574
a3a9a3d2
KW
2575DragonFly BSD now has support for C<setproctitle()>.
2576L<[perl #130068]|https://rt.perl.org/Public/Bug/Display.html?id=130068>.
2c8edc25
S
2577
2578=item *
2579
fb5d4b1a 2580Fix an assertion error which could be triggered when a lookahead string
a3a9a3d2
KW
2581in patterns exceeded a minimum length.
2582L<[perl #130522]|https://rt.perl.org/Public/Bug/Display.html?id=130522>.
2c8edc25
S
2583
2584=item *
2585
a3a9a3d2
KW
2586Only warn once per literal about a misplaced C<"_">.
2587L<[perl #70878]|https://rt.perl.org/Public/Bug/Display.html?id=70878>.
2c8edc25
S
2588
2589=item *
2590
a3a9a3d2
KW
2591Ensure range-start is set after error in C<tr///>.
2592L<[perl #129342]|https://rt.perl.org/Public/Bug/Display.html?id=129342>.
2c8edc25
S
2593
2594=item *
2595
2596Don't read past start of string for unmatched backref; otherwise,
a3a9a3d2
KW
2597we may have heap buffer overflow.
2598L<[perl #129377]|https://rt.perl.org/Public/Bug/Display.html?id=129377>.
2c8edc25
S
2599
2600=item *
2601
2c8edc25 2602C<use re 'strict'> is supposed to warn if you use a range whose start
95b17558 2603and end digit aren't from the same group of 10. It didn't do that
2c8edc25
S
2604for five groups of mathematical digits starting at U+1D7E.
2605
2606=item *
2607
fce64130 2608A sub containing a "forward" declaration with the same name (I<e.g.>,
2c8edc25
S
2609C<sub c { sub c; }>) could sometimes crash or loop infinitely. [perl
2610#129090]
2611
2612=item *
2613
fb5d4b1a 2614A crash in executing a regex with a non-anchored UTF-8 substring against a
a3a9a3d2
KW
2615target string that also used UTF-8 has been fixed.
2616L<[perl #129350]|https://rt.perl.org/Public/Bug/Display.html?id=129350>
2c8edc25
S
2617
2618=item *
2619
2620Previously, a shebang line like C<#!perl -i u> could be erroneously
95b17558 2621interpreted as requesting the C<-u> option. This has been fixed. [perl
2c8edc25
S
2622#129336]
2623
2624=item *
2625
2626The regex engine was previously producing incorrect results in some rare
2627situations when backtracking past a trie that matches only one thing; this
0f032fe1 2628showed up as capture buffers (C<$1>, C<$2>, I<etc.>) erroneously containing data
2c8edc25 2629from regex execution paths that weren't actually executed for the final
a3a9a3d2
KW
2630match.
2631L<[perl #129897]|https://rt.perl.org/Public/Bug/Display.html?id=129897>
2c8edc25
S
2632
2633=item *
2634
2635Certain regexes making use of the experimental C<regex_sets> feature could
a3a9a3d2
KW
2636trigger an assertion failure. This has been fixed.
2637L<[perl #129322]|https://rt.perl.org/Public/Bug/Display.html?id=129322>
2c8edc25
S
2638
2639=item *
2640
fce64130 2641Invalid assignments to a reference constructor (I<e.g.>, C<\eval=time>) could
a3a9a3d2
KW
2642sometimes crash in addition to giving a syntax error.
2643L<[perl #125679]|https://rt.perl.org/Public/Bug/Display.html?id=125679>
2c8edc25
S
2644
2645=item *
2646
2647The parser could sometimes crash if a bareword came after C<evalbytes>.
a3a9a3d2 2648L<[perl #129196]|https://rt.perl.org/Public/Bug/Display.html?id=129196>
2c8edc25
S
2649
2650=item *
2651
2652Autoloading via a method call would warn erroneously ("Use of inherited
2653AUTOLOAD for non-method") if there was a stub present in the package into
2654which the invocant had been blessed. The warning is no longer emitted in
a3a9a3d2
KW
2655such circumstances.
2656L<[perl #47047]|https://rt.perl.org/Public/Bug/Display.html?id=47047>
2c8edc25
S
2657
2658=item *
2659
2c8edc25 2660The use of C<splice> on arrays with nonexistent elements could cause other
a3a9a3d2
KW
2661operators to crash.
2662L<[perl #129164]|https://rt.perl.org/Public/Bug/Display.html?id=129164>
2c8edc25
S
2663
2664=item *
2665
2666Fixed case where C<re_untuit_start> will overshoot the length of a utf8
a3a9a3d2
KW
2667string.
2668L<[perl #129012]|https://rt.perl.org/Public/Bug/Display.html?id=129012>
2c8edc25
S
2669
2670=item *
2671
2672Handle C<CXt_SUBST> better in C<Perl_deb_stack_all>, previously it wasn't
2673checking that the I<current> C<cx> is the right type, and instead was always
a3a9a3d2
KW
2674checking the base C<cx> (effectively a noop).
2675L<[perl #129029]|https://rt.perl.org/Public/Bug/Display.html?id=129029>
2c8edc25
S
2676
2677=item *
2678
95b17558 2679Fixed two possible use-after-free bugs in C<Perl_yylex>. C<Perl_yylex>
2c8edc25 2680maintains up to two pointers into the parser buffer, one of which can
a3a9a3d2
KW
2681become stale under the right conditions.
2682L<[perl #129069]|https://rt.perl.org/Public/Bug/Display.html?id=129069>
2c8edc25
S
2683
2684=item *
2685
2686Fixed a crash with C<s///l> where it thought it was dealing with UTF-8
a3a9a3d2
KW
2687when it wasn't.
2688L<[perl #129038]|https://rt.perl.org/Public/Bug/Display.html?id=129038>
2c8edc25
S
2689
2690=item *
2691
2692Fixed place where regex was not setting the syntax error correctly.
a3a9a3d2 2693L<[perl #129122]|https://rt.perl.org/Public/Bug/Display.html?id=129122>
2c8edc25
S
2694
2695=item *
2696
df48f9a4 2697The C<&.> operator (and the C<"&"> operator, when it treats its arguments as
2c8edc25
S
2698strings) were failing to append a trailing null byte if at least one string
2699was marked as utf8 internally. Many code paths (system calls, regexp
2700compilation) still expect there to be a null byte in the string buffer
2701just past the end of the logical string. An assertion failure was the
a3a9a3d2
KW
2702result.
2703L<[perl #129287]|https://rt.perl.org/Public/Bug/Display.html?id=129287>
2c8edc25
S
2704
2705=item *
2706
95b17558 2707Make sure C<PL_oldoldbufptr> is preserved in C<scan_heredoc()>. In some
a3a9a3d2
KW
2708cases this is used in building error messages.
2709L<[perl #128988]|https://rt.perl.org/Public/Bug/Display.html?id=128988>
2c8edc25
S
2710
2711=item *
2712
570ce26a 2713Fix segfault when run with C<-DC> options on DEBUGGING builds.
a3a9a3d2 2714L<[perl #129106]|https://rt.perl.org/Public/Bug/Display.html?id=129106>
2c8edc25
S
2715
2716=item *
2717
2718Fixed the parser error handling for an 'C<:attr(foo>' that does not have
df48f9a4 2719an ending 'C<")">'.
2c8edc25
S
2720
2721=item *
2722
2723Fix C<Perl_delimcpy()> to handle a backslash as last char, this
a3a9a3d2
KW
2724actually fixed two bugs,
2725L<[perl #129064]|https://rt.perl.org/Public/Bug/Display.html?id=129064> and
2726L<[perl #129176]|https://rt.perl.org/Public/Bug/Display.html?id=129176>.
2c8edc25
S
2727
2728=item *
2729
a3a9a3d2 2730L<[perl #129267]|https://rt.perl.org/Public/Bug/Display.html?id=129267> rework C<gv_fetchmethod_pvn_flags> separator parsing to
0f032fe1 2731prevent possible string overrun with invalid len in F<gv.c>
2c8edc25
S
2732
2733=item *
2734
2735Problems with in-place array sorts: code like C<@a = sort { ... } @a>,
2736where the source and destination of the sort are the same plain array, are
95b17558 2737optimised to do less copying around. Two side-effects of this optimisation
2c8edc25
S
2738were that the contents of C<@a> as visible to to sort routine were
2739partially sorted, and under some circumstances accessing C<@a> during the
95b17558 2740sort could crash the interpreter. Both these issues have been fixed, and
2c8edc25
S
2741Sort functions see the original value of C<@a>.
2742
2743=item *
2744
2745Non-ASCII string delimiters are now reported correctly in error messages
a3a9a3d2
KW
2746for unterminated strings.
2747L<[perl #128701]|https://rt.perl.org/Public/Bug/Display.html?id=128701>
2c8edc25
S
2748
2749=item *
2750
2751C<pack("p", ...)> used to emit its warning ("Attempt to pack pointer to
2752temporary value") erroneously in some cases, but has been fixed.
2753
2754=item *
2755
2756C<@DB::args> is now exempt from "used once" warnings. The warnings only
2757occurred under B<-w>, because F<warnings.pm> itself uses C<@DB::args>
2758multiple times.
2759
2760=item *
2761
2762The use of built-in arrays or hash slices in a double-quoted string no
2763longer issues a warning ("Possible unintended interpolation...") if the
2764variable has not been mentioned before. This affected code like
2765C<qq|@DB::args|> and C<qq|@SIG{'CHLD', 'HUP'}|>. (The special variables
2766C<@-> and C<@+> were already exempt from the warning.)
2767
2768=item *
2769
2770C<gethostent> and similar functions now perform a null check internally, to
d3972b39 2771avoid crashing with torsocks. This was a regression from v5.22. [perl
2c8edc25
S
2772#128740]
2773
2774=item *
2775
2776C<defined *{'!'}>, C<defined *{'['}>, and C<defined *{'-'}> no longer leak
2777memory if the typeglob in question has never been accessed before.
2778
2779=item *
2780
2c8edc25
S
2781Mentioning the same constant twice in a row (which is a syntax error) no
2782longer fails an assertion under debugging builds. This was a regression
a3a9a3d2
KW
2783from v5.20.
2784L<[perl #126482]|https://rt.perl.org/Public/Bug/Display.html?id=126482>
2c8edc25
S
2785
2786=item *
2787
2788Many issues relating to C<printf "%a"> of hexadecimal floating point
2789were fixed. In addition, the "subnormals" (formerly known as "denormals")
fb5d4b1a 2790floating point numbers are now supported both with the plain IEEE 754
2c8edc25
S
2791floating point numbers (64-bit or 128-bit) and the x86 80-bit
2792"extended precision". Note that subnormal hexadecimal floating
2793point literals will give a warning about "exponent underflow".
2794[perl #128843, #128889, #128890, #128893, #128909, #128919]
2795
2796=item *
2797
d3972b39 2798A regression in v5.24 with C<tr/\N{U+...}/foo/> when the code point was between
a3a9a3d2
KW
2799128 and 255 has been fixed.
2800L<[perl #128734]|https://rt.perl.org/Public/Bug/Display.html?id=128734>.
2c8edc25
S
2801
2802=item *
2803
2c8edc25
S
2804Use of a string delimiter whose code point is above 2**31 now works
2805correctly on platforms that allow this. Previously, certain characters,
2806due to truncation, would be confused with other delimiter characters
df48f9a4 2807with special meaning (such as C<"?"> in C<m?...?>), resulting
2c8edc25
S
2808in inconsistent behaviour. Note that this is non-portable,
2809and is based on Perl's extension to UTF-8, and is probably not
a3a9a3d2
KW
2810displayable nor enterable by any editor.
2811L<[perl #128738]|https://rt.perl.org/Public/Bug/Display.html?id=128738>
2c8edc25
S
2812
2813=item *
2814
df48f9a4 2815C<@{x> followed by a newline where C<"x"> represents a control or non-ASCII
2c8edc25 2816character no longer produces a garbled syntax error message or a crash.
a3a9a3d2 2817L<[perl #128951]|https://rt.perl.org/Public/Bug/Display.html?id=128951>
2c8edc25
S
2818
2819=item *
2820
2821An assertion failure with C<%: = 0> has been fixed.
2822L<[perl #128238]|https://rt.perl.org/Public/Bug/Display.html?id=128238>
2823
2824=item *
2825
2826In Perl 5.18, the parsing of C<"$foo::$bar"> was accidentally changed, such
2827that it would be treated as C<$foo."::".$bar>. The previous behavior, which
2828was to parse it as C<$foo:: . $bar>, has been restored.
2829L<[perl #128478]|https://rt.perl.org/Public/Bug/Display.html?id=128478>
2830
2831=item *
2832
2833Since Perl 5.20, line numbers have been off by one when perl is invoked with
2834the B<-x> switch. This has been fixed.
2835L<[perl #128508]|https://rt.perl.org/Public/Bug/Display.html?id=128508>
2836
2837=item *
2838
fce64130 2839Vivifying a subroutine stub in a deleted stash (I<e.g.>, C<delete $My::{"Foo::"};
2c8edc25
S
2840\&My::Foo::foo>) no longer crashes. It had begun crashing in Perl 5.18.
2841L<[perl #128532]|https://rt.perl.org/Public/Bug/Display.html?id=128532>
2842
2843=item *
2844
2845Some obscure cases of subroutines and file handles being freed at the same time
2846could result in crashes, but have been fixed. The crash was introduced in Perl
28475.22.
2848L<[perl #128597]|https://rt.perl.org/Public/Bug/Display.html?id=128597>
2849
2850=item *
2851
2852Code that looks for a variable name associated with an uninitialized value
fb5d4b1a 2853could cause an assertion failure in cases where magic is involved, such as
2c8edc25
S
2854C<$ISA[0][0]>. This has now been fixed.
2855L<[perl #128253]|https://rt.perl.org/Public/Bug/Display.html?id=128253>
2856
2857=item *
2858
2859A crash caused by code generating the warning "Subroutine STASH::NAME
2860redefined" in cases such as C<sub P::f{} undef *P::; *P::f =sub{};> has been
2861fixed. In these cases, where the STASH is missing, the warning will now appear
2862as "Subroutine NAME redefined".
2863L<[perl #128257]|https://rt.perl.org/Public/Bug/Display.html?id=128257>
2864
2865=item *
2866
2867Fixed an assertion triggered by some code that handles deprecated behavior in
fce64130 2868formats, I<e.g.>, in cases like this:
2c8edc25
S
2869
2870 format STDOUT =
2871 @
2872 0"$x"
2873
2874L<[perl #128255]|https://rt.perl.org/Public/Bug/Display.html?id=128255>
2875
2876=item *
2877
2878A possible divide by zero in string transformation code on Windows has been
2879avoided, fixing a crash when collating an empty string.
2880L<[perl #128618]|https://rt.perl.org/Public/Bug/Display.html?id=128618>
2881
2882=item *
2883
2884Some regular expression parsing glitches could lead to assertion failures with
e6abae1c 2885regular expressions such as C</(?E<lt>=/> and C</(?E<lt>!/>. This has now been fixed.
2c8edc25
S
2886L<[perl #128170]|https://rt.perl.org/Public/Bug/Display.html?id=128170>
2887
2888=item *
2889
2890C< until ($x = 1) { ... } > and C< ... until $x = 1 > now properly
a3a9a3d2
KW
2891warn when syntax warnings are enabled.
2892L<[perl #127333]|https://rt.perl.org/Public/Bug/Display.html?id=127333>
2c8edc25
S
2893
2894=item *
2895
2896socket() now leaves the error code returned by the system in C<$!> on
a3a9a3d2
KW
2897failure.
2898L<[perl #128316]|https://rt.perl.org/Public/Bug/Display.html?id=128316>
2c8edc25
S
2899
2900=item *
2901
2902Assignment variants of any bitwise ops under the C<bitwise> feature would
a3a9a3d2
KW
2903crash if the left-hand side was an array or hash.
2904L<[perl #128204]|https://rt.perl.org/Public/Bug/Display.html?id=128204>
2c8edc25
S
2905
2906=item *
2907
2908C<require> followed by a single colon (as in C<foo() ? require : ...> is
0f032fe1 2909now parsed correctly as C<require> with implicit C<$_>, rather than
a3a9a3d2
KW
2910C<require "">.
2911L<[perl #128307]|https://rt.perl.org/Public/Bug/Display.html?id=128307>
2c8edc25
S
2912
2913=item *
2914
2915Scalar C<keys %hash> can now be assigned to consistently in all scalar
2916lvalue contexts. Previously it worked for some contexts but not others.
2917
2918=item *
2919
2920List assignment to C<vec> or C<substr> with an array or hash for its first
2921argument used to result in crashes or "Can't coerce" error messages at run
2922time, unlike scalar assignment, which would give an error at compile time.
a3a9a3d2
KW
2923List assignment now gives a compile-time error, too.
2924L<[perl #128260]|https://rt.perl.org/Public/Bug/Display.html?id=128260>
2c8edc25
S
2925
2926=item *
2927
2928Expressions containing an C<&&> or C<||> operator (or their synonyms C<and>
95b17558 2929and C<or>) were being compiled incorrectly in some cases. If the left-hand
2c8edc25
S
2930side consisted of either a negated bareword constant or a negated C<do {}>
2931block containing a constant expression, and the right-hand side consisted of
2932a negated non-foldable expression, one of the negations was effectively
95b17558
KW
2933ignored. The same was true of C<if> and C<unless> statement modifiers,
2934though with the left-hand and right-hand sides swapped. This long-standing
a3a9a3d2
KW
2935bug has now been fixed.
2936L<[perl #127952]|https://rt.perl.org/Public/Bug/Display.html?id=127952>
2c8edc25
S
2937
2938=item *
2939
2940C<reset> with an argument no longer crashes when encountering stash entries
a3a9a3d2
KW
2941other than globs.
2942L<[perl #128106]|https://rt.perl.org/Public/Bug/Display.html?id=128106>
2c8edc25
S
2943
2944=item *
2945
2946Assignment of hashes to, and deletion of, typeglobs named C<*::::::> no
a3a9a3d2
KW
2947longer causes crashes.
2948L<[perl #128086]|https://rt.perl.org/Public/Bug/Display.html?id=128086>
2c8edc25
S
2949
2950=item *
2951
a3a9a3d2
KW
2952Handle C<SvIMMORTALs> in LHS of list assign.
2953L<[perl #129991]|https://rt.perl.org/Public/Bug/Display.html?id=129991>
2c8edc25
S
2954
2955=item *
2956
a3a9a3d2
KW
2957Assertion failure with user-defined Unicode-like properties.
2958L<[perl #130010]|https://rt.perl.org/Public/Bug/Display.html?id=130010>
2c8edc25
S
2959
2960=item *
2961
2962Fix error message for unclosed C<\N{> in regcomp.
2963
2964An unclosed C<\N{> could give the wrong error message
2965C<"\N{NAME} must be resolved by the lexer">.
2966
2967=item *
2968
2969List assignment in list context where the LHS contained aggregates and
2970where there were not enough RHS elements, used to skip scalar lvalues.
2971Previously, C<(($a,$b,@c,$d) = (1))> in list context returned C<($a)>; now
95b17558
KW
2972it returns C<($a,$b,$d)>. C<(($a,$b,$c) = (1))> is unchanged: it still
2973returns C<($a,$b,$c)>. This can be seen in the following:
2c8edc25
S
2974
2975 sub inc { $_++ for @_ }
2976 inc(($a,$b,@c,$d) = (10))
2977
2978Formerly, the values of C<($a,$b,$d)> would be left as C<(11,undef,undef)>;
2979now they are C<(11,1,1)>.
2980
2981=item *
2982
f632cffa
KW
2983Code like this: C</(?{ s!!! })/> can trigger infinite recursion on the C
2984stack (not the normal perl stack) when the last successful pattern in
2985scope is itself. We avoid the segfault by simply forbidding the use of
2986the empty pattern when it would resolve to the currently executing
a3a9a3d2
KW
2987pattern.
2988L<[perl #129903]|https://rt.perl.org/Public/Bug/Display.html?id=129903>
2c8edc25
S
2989
2990=item *
2991
0c092f6b 2992Avoid reading beyond the end of the line buffer when there's a
a3a9a3d2
KW
2993short UTF-8 character at the end.
2994L<[perl #128997]|https://rt.perl.org/Public/Bug/Display.html?id=128997>
2c8edc25
S
2995
2996=item *
2997
a3a9a3d2
KW
2998Fix firstchar bitmap under utf8 with prefix optimisation.
2999L<[perl #129950]|https://rt.perl.org/Public/Bug/Display.html?id=129950>
2c8edc25
S
3000
3001=item *
3002
a3a9a3d2
KW
3003Make F<Carp/t/arg_string.t>: be liberal in C<f>/C<p> formats.
3004L<[perl #129954]|https://rt.perl.org/Public/Bug/Display.html?id=129954>
2c8edc25
S
3005
3006=item *
3007
a3a9a3d2
KW
3008Make C<do "a\0b"> fail silently instead of throwing an error.
3009L<[perl #129928]|https://rt.perl.org/Public/Bug/Display.html?id=129928>
2c8edc25
S
3010
3011=item *
3012
a3a9a3d2
KW
3013Make C<chdir> allocate the stack it needs.
3014L<[perl #129130]|https://rt.perl.org/Public/Bug/Display.html?id=129130>
2c8edc25 3015
acea3104
KW
3016=item *
3017
3018C<do> errors now refer to C<do> (not C<require>).
3019
3020=item *
3021
3022Executing C<undef $x> where C<$x> is tied or magical no longer incorrectly
3023blames the variable for an uninitialized-value warning encountered by the
3024tied/magical code.
3025
3026=item *
3027
3028Code like C<$x = $x . "a"> was incorrectly failing to yield a
3029L<use of uninitialized value|perldiag/"Use of uninitialized value%s">
3030warning when C<$x> was a lexical variable with an undefined value. That has
a3a9a3d2
KW
3031now been fixed.
3032L<[perl #127877]|https://rt.perl.org/Public/Bug/Display.html?id=127877>
acea3104
KW
3033
3034=item *
3035
3036C<undef *_; shift> or C<undef *_; pop> inside a subroutine, with no
3037argument to C<shift> or C<pop>, began crashing in Perl 5.14, but has now
3038been fixed.
3039
3040=item *
3041
3042C<< "string$scalar-E<gt>$*" >> now correctly prefers concat overloading to
3043string overloading if C<< $scalar-E<gt>$* >> returns an overloaded object,
3044bringing it into consistency with C<$$scalar>.
3045
3046=item *
3047
3048C<< /@0{0*-E<gt>@*/*0 >> and similar contortions used to crash, but no longer
a3a9a3d2
KW
3049do, but merely produce a syntax error.
3050L<[perl #128171]|https://rt.perl.org/Public/Bug/Display.html?id=128171>
acea3104
KW
3051
3052=item *
3053
3054C<do> or C<require> with a reference or typeglob which, when stringified,
3055contains a null character started crashing in Perl 5.20, but has now been
a3a9a3d2
KW
3056fixed.
3057L<[perl #128182]|https://rt.perl.org/Public/Bug/Display.html?id=128182>
acea3104
KW
3058
3059=item *
3060
3061Improve error for missing C<tie()> package/method. This brings the error messages
3062in line with the ones used for normal method calls, despite not using
3063call_method().
3064
2c8edc25
S
3065=back
3066
3067=head1 Known Problems
3068
3069=over 4
3070
3071=item *
3072
3073Some modules have been broken by the L<context stack rework|/Internal Changes>.
fb5d4b1a
KW
3074These modules were relying on non-guaranteed implementation details in
3075the perl interpreter.
2c8edc25
S
3076Their maintainers have been informed, and should contact perl5-porters for
3077advice if needed. Below is a subset of these modules:
3078
3079=over 4
3080
3081=item * L<Algorithm::Permute>
3082
3083=item * L<Coro>
3084
fb5d4b1a
KW
3085L<Coro> and Perl 5.22 were already incompatible due to a change in the perl
3086interpreter,
2c8edc25
S
3087and the reworking on the perl context stack creates a further incompatibility.
3088perl5-porters has L<discussed the issue on the mailing
3089list|http://www.nntp.perl.org/group/perl.perl5.porters/2016/05/msg236174.html>.
3090
3091=item * L<Data::Alias>
3092
3093=item * L<RPerl>
3094
3095=item * L<Scope::Upper>
3096
3097=item * L<TryCatch>
3098
3099=back
3100
3101=item *
3102
53799a91 3103The module L<lexical::underscore> no longer works on Perl 5.24, because perl
2c8edc25
S
3104no longer has a lexical C<$_>!
3105
3106=item *
3107
53799a91 3108C<mod_perl> has been patched for compatibility for v5.22 and later but no
2c8edc25
S
3109release has been made. The relevant patch (and other changes) can be found in
3110their source code repository, L<mirrored at
3111GitHub|https://github.com/apache/mod_perl/commit/82827132efd3c2e25cc413c85af61bb63375da6e>.
3112
3113=back
3114
3115=head1 Errata From Previous Releases
3116
3117=over 4
3118
3119=item *
3120
ee8180b8 3121Parsing bad POSIX charclasses no longer leaks memory.
2c8edc25
S
3122L<[perl #128313]|https://rt.perl.org/Public/Bug/Display.html?id=128313>
3123
3124=item *
3125
53799a91 3126Fixed issues with recursive regexes. The behavior was fixed in Perl 5.24.
2c8edc25
S
3127L<[perl #126182]|https://rt.perl.org/Public/Bug/Display.html?id=126182>
3128
3129=back
3130
3131=head1 Obituary
3132
3133Jon Portnoy (AVENJ), a prolific Perl author and admired Gentoo community
95b17558 3134member, has passed away on August 10, 2016. He will be remembered and
c94c0e4f 3135missed by all those who he came in contact with, and enriched with his
2c8edc25
S
3136intellect, wit, and spirit.
3137
c94c0e4f 3138It is with great sadness that we also note Kip Hampton's passing. Probably
2c8edc25
S
3139best known as the author of the Perl & XML column on XML.com, he was a
3140core contributor to AxKit, an XML server platform that became an Apache
95b17558
KW
3141Foundation project. He was a frequent speaker in the early days at
3142OSCON, and most recently at YAPC::NA in Madison. He was frequently on
2c8edc25
S
3143irc.perl.org as `ubu`, generally in the #axkit-dahut community, the
3144group responsible for YAPC::NA Asheville in 2011.
a049258c 3145
2c8edc25
S
3146Kip and his constant contributions to the community will be greatly
3147missed.
a049258c
S
3148
3149=head1 Acknowledgements
2e0dcc12 3150
0cc8c746 3151Perl 5.26.0 represents approximately 12 months of development since Perl 5.24.0
c2948ced 3152and contains approximately 370,000 lines of changes across 2,600 files from 86
0cc8c746
S
3153authors.
3154
3155Excluding auto-generated files, documentation and release tools, there were
3156approximately 230,000 lines of changes to 1,800 .pm, .t, .c and .h files.
3157
3158Perl continues to flourish into its third decade thanks to a vibrant community
95b17558 3159of users and developers. The following people are known to have contributed the
ad543fb2 3160improvements that became Perl 5.26.0:
0cc8c746
S
3161
3162Aaron Crane, Abigail, Ævar Arnfjörð Bjarmason, Alex Vandiver, Andreas
3163König, Andreas Voegele, Andrew Fresh, Andy Lester, Aristotle Pagaltzis, Chad
3164Granum, Chase Whitener, Chris 'BinGOs' Williams, Chris Lamb, Christian Hansen,
3165Christian Millour, Colin Newell, Craig A. Berry, Dagfinn Ilmari Mannsåker, Dan
c2948ced
S
3166Collins, Daniel Dragan, Dave Cross, Dave Rolsky, David Golden, David H.
3167Gutteridge, David Mitchell, Dominic Hargreaves, Doug Bell, E. Choroba, Ed Avis,
3168Father Chrysostomos, François Perrad, Hauke D, H.Merijn Brand, Hugo van der
3169Sanden, Ivan Pozdeev, James E Keenan, James Raspass, Jarkko Hietaniemi, Jerry
3170D. Hedden, Jim Cromie, J. Nick Koston, John Lightsey, Karen Etheridge, Karl
3171Williamson, Leon Timmermans, Lukas Mai, Matthew Horsfall, Maxwell Carey, Misty
3172De Meo, Neil Bowers, Nicholas Clark, Nicolas R., Niko Tyni, Pali, Paul
3173Marquess, Peter Avalos, Petr Písař, Pino Toscano, Rafael Garcia-Suarez, Reini
3174Urban, Renee Baecker, Ricardo Signes, Richard Levitte, Rick Delaney, Salvador
3175Fandiño, Samuel Thibault, Sawyer X, Sébastien Aperghis-Tramoni, Sergey
3176Aleynikov, Shlomi Fish, Smylers, Stefan Seifert, Steffen Müller, Stevan
3177Little, Steve Hay, Steven Humphrey, Sullivan Beck, Theo Buehler, Thomas Sibley,
3178Todd Rinaldo, Tomasz Konojacki, Tony Cook, Unicode Consortium, Yaroslav Kuzmin,
3179Yves Orton, Zefram.
0cc8c746
S
3180
3181The list above is almost certainly incomplete as it is automatically generated
95b17558 3182from version control history. In particular, it does not include the names of
0cc8c746
S
3183the (very much appreciated) contributors who reported issues to the Perl bug
3184tracker.
3185
3186Many of the changes included in this version originated in the CPAN modules
95b17558 3187included in Perl's core. We're grateful to the entire CPAN community for
0cc8c746
S
3188helping Perl to flourish.
3189
3190For a more complete list of all of Perl's historical contributors, please see
3191the F<AUTHORS> file in the Perl source distribution.
f5b73711 3192
44691e6f
AB
3193=head1 Reporting Bugs
3194
2c8edc25
S
3195If you find what you think is a bug, you might check the articles recently
3196posted to the comp.lang.perl.misc newsgroup and the perl bug database at
3197L<https://rt.perl.org/> . There may also be information at
4b8803f0 3198L<http://www.perl.org/> , the Perl Home Page.
44691e6f 3199
e08634c5
SH
3200If you believe you have an unreported bug, please run the L<perlbug> program
3201included with your release. Be sure to trim your bug down to a tiny but
3202sufficient test case. Your bug report, along with the output of C<perl -V>,
7c825fca 3203will be sent off to C<perlbug@perl.org> to be analysed by the Perl porting team.
44691e6f 3204
87c118b9
DM
3205If the bug you are reporting has security implications which make it
3206inappropriate to send to a publicly archived mailing list, then see
c0ea3294
SH
3207L<perlsec/SECURITY VULNERABILITY CONTACT INFORMATION>
3208for details of how to report the issue.
44691e6f
AB
3209
3210=head1 SEE ALSO
3211
e08634c5
SH
3212The F<Changes> file for an explanation of how to view exhaustive details on
3213what changed.
44691e6f
AB
3214
3215The F<INSTALL> file for how to build Perl.
3216
3217The F<README> file for general stuff.
3218
3219The F<Artistic> and F<Copying> files for copyright information.
3220
3221=cut