5 perldelta - what is new for perl v5.17.8
9 This document describes differences between the 5.17.7 release and the 5.17.8
12 If you are upgrading from an earlier release such as 5.17.6, first read
13 L<perl5177delta>, which describes differences between 5.17.6 and 5.17.7.
15 =head1 Core Enhancements
17 =head2 Regular Expression Set Operations
19 This is an experimental feature to allow matching against the the union,
20 intersection, etc., of sets of code points, similar to
21 L<Unicode::Regex::Set>. It can also be used to extend C</x> processing
22 to [bracketed] character classes, and as a replacement of user-defined
23 properties, allowing more complex expressions than they do. See
28 =head2 Deprecated modules
30 The Pod::LaTeX module is now deprecated, and due to be moved out of the Perl
31 core in 5.20. Until then, using the core-installed version will produce a
32 warning. You can suppress the warning by installing the module from CPAN.
34 =head2 User-defined charnames with surprising whitespace
36 A user-defined character name with trailing or multiple spaces in a row is
37 likely a typo. This now generates a warning when defined, on the assumption
38 that uses of it will be unlikely to include the excess whitespace.
40 =head2 Various XS-callable functions are now deprecated
42 All the functions used to classify characters will be removed from a
43 future version of Perl, and should not be used. With participating C
44 compilers (e.g., gcc), compiling any file that uses any of these will
45 generate a warning. These were not intended for public use; there are
46 equivalent, faster, macros for most of them.
47 See L<perlapi/Character classes>. The complete list (including some
48 that were deprecated in 5.17.7) is:
49 C<is_uni_alnum>, C<is_uni_alnumc>, C<is_uni_alnumc_lc>,
50 C<is_uni_alnum_lc>, C<is_uni_alpha>, C<is_uni_alpha_lc>,
51 C<is_uni_ascii>, C<is_uni_ascii_lc>, C<is_uni_blank>,
52 C<is_uni_blank_lc>, C<is_uni_cntrl>, C<is_uni_cntrl_lc>,
53 C<is_uni_digit>, C<is_uni_digit_lc>, C<is_uni_graph>,
54 C<is_uni_graph_lc>, C<is_uni_idfirst>, C<is_uni_idfirst_lc>,
55 C<is_uni_lower>, C<is_uni_lower_lc>, C<is_uni_print>,
56 C<is_uni_print_lc>, C<is_uni_punct>, C<is_uni_punct_lc>,
57 C<is_uni_space>, C<is_uni_space_lc>, C<is_uni_upper>,
58 C<is_uni_upper_lc>, C<is_uni_xdigit>, C<is_uni_xdigit_lc>,
59 C<is_utf8_alnum>, C<is_utf8_alnumc>, C<is_utf8_alpha>,
60 C<is_utf8_ascii>, C<is_utf8_blank>, C<is_utf8_char>,
61 C<is_utf8_cntrl>, C<is_utf8_digit>, C<is_utf8_graph>,
62 C<is_utf8_idcont>, C<is_utf8_idfirst>, C<is_utf8_lower>,
63 C<is_utf8_mark>, C<is_utf8_perl_space>, C<is_utf8_perl_word>,
64 C<is_utf8_posix_digit>, C<is_utf8_print>, C<is_utf8_punct>,
65 C<is_utf8_space>, C<is_utf8_upper>, C<is_utf8_xdigit>,
66 C<is_utf8_xidcont>, C<is_utf8_xidfirst>.
68 In addition these three functions that have never worked properly are
70 C<to_uni_lower_lc>, C<to_uni_title_lc>, and C<to_uni_upper_lc>.
72 =head2 Certain rare uses of backslashes within regexes are now deprectated
74 There are three pairs of characters that Perl recognizes as
75 metacharacters in regular expression patterns: C<{}>, C<[]>, and C<()>.
76 These can be used as well to delimit patterns, as in:
81 Since they are metacharacters, they have special meaning to regular
82 expression patterns, and it turns out that you can't turn off that
83 special meaning by the normal means of preceding them with a backslash,
84 if you use them, paired, within a pattern delimitted by them. For
89 the backslashes do not change the behavior, and this matches
90 S<C<"f o">> followed by one to three more occurrences of C<"o">.
92 Usages like this, where they are interpreted as metacharacters, are
93 exceedingly rare; we think there are none, for example, in all of CPAN.
94 Hence, this deprecation should affect very little code. It does give
95 notice, however, that any such code needs to change, which will in turn
96 allow us to change the behavior in future Perl versions so that the
97 backslashes do have an effect, and without fear that we are silently
98 breaking any existing code.
100 =head1 Modules and Pragmata
102 =head2 Selected Updates to Modules and Pragmata
108 Several modules have had their version number changed to one with no
109 underscore, since such version numbers are usually interpreted to mean
110 "development-only version". No other changes have been made in these cases.
111 The affected modules are:
117 L<I18N::Langinfo> was 0.08_02 and is now 0.09
121 L<I18N::LangTags::List> was 0.35_01 and is now 0.39
125 L<IO> was 1.25_08 and is now 1.26
129 L<Safe> was 2.33_01 and is now 2.34
133 L<Test> was 1.25_02 and is now 1.26.
139 L<Digest::SHA> has been upgraded from version 5.80 to 5.81. This fixes a
140 double-free bug, which might have caused vulnerabilities in some cases.
144 L<Socket> has been upgraded from 2.006_001 to 2.009. This fixes an
145 uninitialized memory read.
151 The following additions or changes have been made to diagnostic output,
152 including warnings and fatal error messages. For the complete list of
153 diagnostic messages, see L<perldiag>.
155 =head2 New Diagnostics
163 L<'%s' resolved to '\o{%s}%d'|perldiag/"'%s' resolved to '\o{%s}%d'">
167 L<'Trailing white-space in a charnames alias definition is deprecated'|perldiag/"Trailing white-space in a charnames alias definition is deprecated">
171 L<'A sequence of multiple spaces in a charnames alias definition is deprecated'|perldiag/"A sequence of multiple spaces in a charnames alias definition is deprecated">
175 L<'Passing malformed UTF-8 to "%s" is deprecated'|perldiag/"Passing malformed UTF-8 to "%s" is deprecated">
185 Many more of the core's tests now have descriptions.
189 Thread stress-tests now adapt to the speed of the machine running the tests,
190 thus reducing the incidence of false failures.
194 =head1 Platform Support
196 =head2 Discontinued Platforms
202 Support for Rhapsody has been removed.
206 =head2 Platform-Specific Notes
212 Perl can now be built using Microsoft's Visual C++ 2012 compiler by specifying
213 CCTYPE=MSVC110 (or MSVC110FREE if you are using the free Express edition for
214 Windows Desktop) in F<win32/Makefile>.
218 Perl should now work out of the box on Haiku R1 Alpha 4.
222 =head1 Internal Changes
228 A synonym for the misleadingly named C<av_len()> has been created:
229 C<av_top()>. Both of these return the number of the highest index in
230 the array, not the number of elements it contains.
234 =head1 Selected Bug Fixes
240 A bug in the core typemap caused any C types that map to the T_BOOL core
241 typemap entry to not be set, updated, or modified when the T_BOOL variable was
242 used in an OUTPUT: section with an exception for RETVAL. T_BOOL in an INPUT:
243 section was not affected. Using a T_BOOL return type for an XSUB (RETVAL)
244 was not affected. A side effect of fixing this bug is, if a T_BOOL is specified
245 in the OUTPUT: section (which previous did nothing to the SV), and a read only
246 SV (literal) is passed to the XSUB, croaks like "Modification of a read-only
247 value attempted" will happen. [perl #115796]
251 On many platforms, providing a directory name as the script name caused perl
252 to do nothing and report success. It should now universally report an error
253 and exit nonzero. [perl #61362]
257 =head1 Known Problems
263 Perl 5.17.7 introduced a new internal copy-on-write mechanism, in the
264 interests of speed. An flaw in the implementation means that some regexp
265 matches which previously completed very fast, without invoking the full
266 regexp engine, now run much slower than before. We expect this performance
267 problem to be resolved before 5.18.0 is released.
271 The C<POSIX> module may yield test failures when building on a ZFS
272 filesystem under FreeBSD.
276 =head1 Acknowledgements
278 Perl 5.17.8 represents approximately 5 weeks of development since Perl 5.17.7
279 and contains approximately 18,000 lines of changes across 280 files from 24
282 Perl continues to flourish into its third decade thanks to a vibrant community
283 of users and developers. The following people are known to have contributed the
284 improvements that became Perl 5.17.8:
286 Aaron Crane, Andy Dougherty, Augustina Blair, Chris 'BinGOs' Williams, Craig
287 A. Berry, Daniel Dragan, Dave Rolsky, David Mitchell, Eric Brine, Father
288 Chrysostomos, H.Merijn Brand, James E Keenan, Jerry D. Hedden, Jesse Luehrs,
289 Karl Williamson, Matthew Horsfall, Nicholas Clark, Renee Baecker, Ricardo
290 Signes, Shlomi Fish, Steffen Müller, Steve Hay, Steven Schubiger, Tony Cook.
292 The list above is almost certainly incomplete as it is automatically generated
293 from version control history. In particular, it does not include the names of
294 the (very much appreciated) contributors who reported issues to the Perl bug
297 Many of the changes included in this version originated in the CPAN modules
298 included in Perl's core. We're grateful to the entire CPAN community for
299 helping Perl to flourish.
301 For a more complete list of all of Perl's historical contributors, please see
302 the F<AUTHORS> file in the Perl source distribution.
304 =head1 Reporting Bugs
306 If you find what you think is a bug, you might check the articles recently
307 posted to the comp.lang.perl.misc newsgroup and the perl bug database at
308 http://rt.perl.org/perlbug/ . There may also be information at
309 http://www.perl.org/ , the Perl Home Page.
311 If you believe you have an unreported bug, please run the L<perlbug> program
312 included with your release. Be sure to trim your bug down to a tiny but
313 sufficient test case. Your bug report, along with the output of C<perl -V>,
314 will be sent off to perlbug@perl.org to be analysed by the Perl porting team.
316 If the bug you are reporting has security implications, which make it
317 inappropriate to send to a publicly archived mailing list, then please send it
318 to perl5-security-report@perl.org. This points to a closed subscription
319 unarchived mailing list, which includes all the core committers, who will be
320 able to help assess the impact of issues, figure out a resolution, and help
321 co-ordinate the release of patches to mitigate or fix the problem across all
322 platforms on which Perl is supported. Please only use this address for
323 security issues in the Perl core, not for modules independently distributed on
328 The F<Changes> file for an explanation of how to view exhaustive details on
331 The F<INSTALL> file for how to build Perl.
333 The F<README> file for general stuff.
335 The F<Artistic> and F<Copying> files for copyright information.