PERL5232DELTA(1) Perl Programmers Reference Guide PERL5232DELTA(1)NAMEperl5232delta - what is new for perl v5.23.2
DESCRIPTION
This document describes differences between the 5.23.1 release and the
5.23.2 release.
If you are upgrading from an earlier release such as 5.23.0, first read
perl5231delta, which describes differences between 5.23.0 and 5.23.1.
Incompatible Changes
Nested declarations are now disallowed
A "my", "our", or "state" declaration is no longer allowed inside of
another "my", "our", or "state" declaration.
For example, these are now fatal:
my ($x, my($y));
our (my $x);
[perl #125587] <https://rt.perl.org/Ticket/Display.html?id=125587>
[perl #121058] <https://rt.perl.org/Ticket/Display.html?id=121058>
Deprecationssysread(), syswrite(), recv() and send() are deprecated on :utf8 handles
The sysread(), recv(), syswrite() and send() operators are deprecated
on handles that have the ":utf8" layer, either explicitly, or
implicitly, eg., with the ":encoding(UTF-16LE)" layer.
Both sysread() and recv() currently use only the ":utf8" flag for the
stream, ignoring the actual layers. Since sysread() and recv() do no
UTF-8 validation they can end up creating invalidly encoded scalars.
Similarly, syswrite() and send() use only the ":utf8" flag, otherwise
ignoring any layers. If the flag is set, both write the value UTF-8
encoded, even if the layer is some different encoding, such as the
example above.
Ideally, all of these operators would completely ignore the ":utf8"
state, working only with bytes, but this would result in silently
breaking existing code. To avoid this a future version of perl will
throw an exception when any of sysread(), recv(), syswrite() or send()
are called on handle with the ":utf8" layer.
Performance Enhancements
· Creating Perl debugger data structures (see "Debugger Internals" in
perldebguts) for XSUBs and const subs has been removed. This
removed one glob/scalar combo for each unique ".c" file that XSUBs
and const subs came from. On startup ("perl -e"0"") about half a
dozen glob/scalar debugger combos were created. Loading XS modules
created more glob/scalar combos. These things were created
regardless if the perl debugger was being used or not, unlike for
pure perl subs, and ignores that the perl debugger can not debug C
code.
· Single arguments in list assign are now slightly faster:
($x) = (...);
(...) = ($x);
Modules and Pragmata
Updated Modules and Pragmata
· The PathTools module collection has been upgraded from version 3.55
to 3.56.
Minor optimizations. [perl #125712]
<https://rt.perl.org/Ticket/Display.html?id=125712>
· Attribute::Handlers has been upgraded from version 0.97 to 0.99.
· CPAN::Meta::YAML has been upgraded from version 0.016 to 0.017.
· Encode has been upgraded from version 2.75 to 2.76.
· ExtUtils::ParseXS has been upgraded from version 3.28 to 3.29.
· ExtUtils::Typemaps has been upgraded from version 3.28 to 3.29.
· File::Find has been upgraded from version 1.29 to 1.30.
· File::Spec has been upgraded from version 3.56 to 3.57.
· Filter::Util::Call has been upgraded from version 1.54 to 1.55.
· Hash::Util has been upgraded from version 0.18 to 0.19.
"unlock_hashref_recurse" and "unlock_hash_recurse" didn't actually
unlock parts of the data structures...
...now they do.
· Module::CoreList has been upgraded from version 5.20150720 to
5.20150820.
· perlfaq has been upgraded from version 5.021009 to 5.021010.
· POSIX has been upgraded from version 1.55 to 1.56.
· Term::Cap has been upgraded from version 1.15 to 1.17.
· Unicode::UCD has been upgraded from version 0.61 to 0.62.
Documentation
Changes to Existing Documentation
perlpolicy
· This note has been added to perlpolicy:
While civility is required, kindness is encouraged; if you have any doubt
about whether you are being civil, simply ask yourself, "Am I being kind?"
and aspire to that.
perlvar
· Use of $OLD_PERL_VERSION is now discouraged.
Diagnostics
The following additions or changes have been made to diagnostic output,
including warnings and fatal error messages. For the complete list of
diagnostic messages, see perldiag.
New Diagnostics
New Errors
· Can't redeclare "%s" in "%s"
(F) A "my", "our" or "state" declaration was found within another
declaration, such as "my ($x, my($y), $z)" or "our (my $x)".
New Warnings
· %s() is deprecated on :utf8 handles
(W deprecated) The sysread(), recv(), syswrite() and send()
operators are deprecated on handles that have the ":utf8" layer,
either explicitly, or implicitly, eg., with the
":encoding(UTF-16LE)" layer.
Both sysread() and recv() currently use only the ":utf8" flag for
the stream, ignoring the actual layers. Since sysread() and recv()
do no UTF-8 validation they can end up creating invalidly encoded
scalars.
Similarly, syswrite() and send() use only the ":utf8" flag,
otherwise ignoring any layers. If the flag is set, both write the
value UTF-8 encoded, even if the layer is some different encoding,
such as the example above.
Ideally, all of these operators would completely ignore the ":utf8"
state, working only with bytes, but this would result in silently
breaking existing code. To avoid this a future version of perl
will throw an exception when any of sysread(), recv(), syswrite()
or send() are called on handle with the ":utf8" layer.
Changes to Existing Diagnostics
· The diagnostic "Hexadecimal float: internal error" has been changed
to "Hexadecimal float: internal error (%s)" to include more
information.
Configuration and Compilation
· Configure should handle spaces in paths a little better.
Testing
· A new test (t/op/aassign.t) has been added to test the list
assignment operator "OP_AASSIGN".
Internal Changes
· "PL_sawalias" and "GPf_ALIASED_SV" have been removed.
· "GvASSIGN_GENERATION" and "GvASSIGN_GENERATION_set" have been
removed.
Selected Bug Fixes
· Perl can again be compiled with any Unicode version. This used to
(mostly) work, but was lost in v5.18 through v5.20. The property
"Name_Alias" did not exist prior to Unicode 5.0. Unicode::UCD
incorrectly said it did. This has been fixed.
· Very large code-points (beyond Unicode) in regular expressions no
longer cause a buffer overflow in some cases when converted to
UTF-8. [perl #125826]
<https://rt.perl.org/Ticket/Display.html?id=125826>
· The integer overflow check for the range operator (...) in list
context now correctly handles the case where the size of the range
is larger than the address space. This could happen on 32-bits
with -Duse64bitint. [perl #125781]
<https://rt.perl.org/Ticket/Display.html?id=125781>
· A crash with "%::=(); J->${\"::"}" has been fixed. [perl #125541]
<https://rt.perl.org/Ticket/Display.html?id=125541>
Acknowledgements
Perl 5.23.2 represents approximately 4 weeks of development since Perl
5.23.1 and contains approximately 22,000 lines of changes across 240
files from 23 authors.
Excluding auto-generated files, documentation and release tools, there
were approximately 17,000 lines of changes to 140 .pm, .t, .c and .h
files.
Perl continues to flourish into its third decade thanks to a vibrant
community of users and developers. The following people are known to
have contributed the improvements that became Perl 5.23.2:
Aaron Priven, Aristotle Pagaltzis, Chris 'BinGOs' Williams, Craig A.
Berry, Dagfinn Ilmari Mannsaaker, Daniel Dragan, David Mitchell, Ed J,
Father Chrysostomos, H.Merijn Brand, Ivan Pozdeev, James E Keenan,
Jarkko Hietaniemi, Karen Etheridge, Karl Williamson, Ludovic E. R.
Tolhurst-Cleaver, Lukas Mai, Matthew Horsfall, Reini Urban, Ricardo
Signes, Sisyphus, Steve Hay, Tony Cook.
The list above is almost certainly incomplete as it is automatically
generated from version control history. In particular, it does not
include the names of the (very much appreciated) contributors who
reported issues to the Perl bug tracker.
Many of the changes included in this version originated in the CPAN
modules included in Perl's core. We're grateful to the entire CPAN
community for helping Perl to flourish.
For a more complete list of all of Perl's historical contributors,
please see the AUTHORS file in the Perl source distribution.
Reporting Bugs
If you find what you think is a bug, you might check the articles
recently posted to the comp.lang.perl.misc newsgroup and the perl bug
database at <https://rt.perl.org/> . There may also be information at
<http://www.perl.org/> , the Perl Home Page.
If you believe you have an unreported bug, please run the perlbug
program included with your release. Be sure to trim your bug down to a
tiny but sufficient test case. Your bug report, along with the output
of "perl -V", will be sent off to perlbug@perl.org to be analysed by
the Perl porting team.
If the bug you are reporting has security implications, which make it
inappropriate to send to a publicly archived mailing list, then please
send it to perl5-security-report@perl.org. This points to a closed
subscription unarchived mailing list, which includes all the core
committers, who will be able to help assess the impact of issues,
figure out a resolution, and help co-ordinate the release of patches to
mitigate or fix the problem across all platforms on which Perl is
supported. Please only use this address for security issues in the
Perl core, not for modules independently distributed on CPAN.
SEE ALSO
The Changes file for an explanation of how to view exhaustive details
on what changed.
The INSTALL file for how to build Perl.
The README file for general stuff.
The Artistic and Copying files for copyright information.
perl v5.23.3 2015-09-08 PERL5232DELTA(1)
