| perldelta - what is new for perl v5.30.0 |
"n" specifiable in a regular expression quantifier of the form "{m,n}" has been doubled to 65534-Drv now means something on -DDEBUGGING builds$[ is fatal"{" insysread()/syswrite() on :utf8 handles is now fatalmy() in false conditional prohibiteddump()pack() no longer can return malformed UTF-8
perldelta - what is new for perl v5.30.0
This document describes differences between the 5.28.0 release and the 5.30.0 release.
If you are upgrading from an earlier release such as 5.26.0, first read the perl5280delta manpage, which describes differences between 5.26.0 and 5.28.0.
sv_utf8_(downgrade|decode) are no longer marked as experimental.
[perl #133788].
Using a lookbehind assertion (like (?<=foo?) or (?<!ba{1,9}r) previously
would generate an error and refuse to compile. Now it compiles (if the
maximum lookbehind is at most 255 characters), but raises a warning in
the new experimental::vlb warnings category. This is to caution you
that the precise behavior is subject to change based on feedback from
use in the field.
See (?<=pattern) in the perlre manpage and (?<!pattern) in the perlre manpage.
"n" specifiable in a regular expression quantifier of the form "{m,n}" has been doubled to 65534The meaning of an unbounded upper quantifier "{m,}" remains unchanged.
It matches 2**31 - 1 times on most platforms, and more on ones where a C
language short variable is more than 4 bytes long.
Because of a change in Unicode release cycles, Perl jumps from Unicode 10.0 in Perl 5.28 to Unicode 12.1 in Perl 5.30.
For details on the Unicode changes, see https://www.unicode.org/versions/Unicode11.0.0/ for 11.0; https://www.unicode.org/versions/Unicode12.0.0/ for 12.0; and https://www.unicode.org/versions/Unicode12.1.0/ for 12.1. (Unicode 12.1 differs from 12.0 only in the addition of a single character, that for the new Japanese era name.)
The Word_Break property, as in past Perl releases, remains tailored to behave more in line with expectations of Perl users. This means that sequential runs of horizontal white space characters are not broken apart, but kept as a single run. Unicode 11 changed from past versions to be more in line with Perl, but it left several white space characters as causing breaks: TAB, NO BREAK SPACE, and FIGURE SPACE (U+2007). We have decided to continue to use the previous Perl tailoring with regards to these.
You can now do something like this in a regular expression pattern
qr! \p{nv= /(?x) \A [0-5] \z / }!
which matches all Unicode code points whose numeric value is between 0 and 5 inclusive. So, it could match the Thai or Bengali digits whose numeric values are 0, 1, 2, 3, 4, or 5.
This marks another step in implementing the regular expression features the Unicode Consortium suggests.
Most properties are supported, with the remainder planned for 5.32. Details are in Wildcards in Property Values in the perlunicode manpage.
Previously it was an error to evaluate a named character \N{...}
within a single quoted regular expression pattern (whose evaluation is
deferred from the normal place). This restriction is now removed.
Turkic languages have different casing rules than other languages for
the characters "i" and "I". The uppercase of "i" is LATIN
CAPITAL LETTER I WITH DOT ABOVE (U+0130); and the lowercase of "I" is LATIN
SMALL LETTER DOTLESS I (U+0131). Unicode furnishes alternate casing
rules for use with Turkic languages. Previously, Perl ignored these,
but now, it uses them when it detects that it is operating under a
Turkic UTF-8 locale.
Previously, these calls were only used when the perl was compiled to be multi-threaded. To always enable them, add
-Accflags='-DUSE_THREAD_SAFE_LOCALE'
to your Configure flags.
This macro is still defined but no longer used in core
-Drv now means something on -DDEBUGGING buildsNow, adding the verbose flag (-Dv) to the -Dr flag turns on all
possible regular expression debugging.
$[ is fatalSetting $[ to a non-zero value has been deprecated since
Perl 5.12 and now throws a fatal error.
See Assigning non-zero to $[ is fatal in the perldeprecation manpage.
"{" in
regular expression patterns are now illegalBut to avoid breaking code unnecessarily, most instances that issued a deprecation warning, remain legal and now have a non-deprecation warning raised. See Unescaped left braces in regular expressions in the perldeprecation manpage.
sysread()/syswrite() on :utf8 handles is now fatalCalling sysread(), syswrite(), send() or recv() on a :utf8 handle,
whether applied explicitly or implicitly, is now fatal. This was
deprecated in perl 5.24.
There were two problems with calling these functions on :utf8
handles:
:utf8 flag. Other
layers were completely ignored, so a handle with
:encoding(UTF-16LE) layer would be treated as UTF-8. Other layers,
such as compression are completely ignored with or without the
:utf8 flag.
sysread() and recv() would read from the handle, skipping any
validation by the layers, and do no validation of their own. This
could lead to invalidly encoded perl scalars.
[perl #125760].
my() in false conditional prohibitedDeclarations such as my $x if 0 are no longer permitted.
[perl #133543].
These special variables, long deprecated, now throw exceptions when used.
[perl #133583].
dump()The dump() function, long discouraged, may no longer be used unless it is
fully qualified, i.e., CORE::dump().
[perl #133584].
The File::Glob::glob() function, long deprecated, has been removed and now
throws an exception which advises use of File::Glob::bsd_glob() instead.
[perl #133586].
pack() no longer can return malformed UTF-8It croaks if it would otherwise return a UTF-8 string that contains malformed UTF-8. This protects against potential security threats. This is considered a bug fix as well. [perl #131642].
There are several sets of digits in the Common script. [0-9] is the
most familiar. But there are also [\x{FF10}-\x{FF19}] (FULLWIDTH
DIGIT ZERO - FULLWIDTH DIGIT NINE), and several sets for use in
mathematical notation, such as the MATHEMATICAL DOUBLE-STRUCK DIGITs.
Any of these sets should be able to appear in script runs of, say,
Greek. But the design of 5.30 overlooked all but the ASCII digits
[0-9], so the design was flawed. This has been fixed, so is both a
bug fix and an incompatibility.
[perl #133547].
All digits in a run still have to come from the same set of ten digits.
As JSON::XS 4.0 changed its policy and enabled allow_nonref by default, JSON::PP also enabled allow_nonref by default.
This deprecation was scheduled to become fatal in 5.30, but has been delayed to 5.32 due to problems that showed up with some CPAN modules. For details of what's affected, see perldeprecation.
ord("\x7fff") now requires 12% fewer instructions than before. The
performance of checking that a sequence of bytes is valid UTF-8 is similarly
improved, again by using a DFA.
Eliminate recursion from finalize_op().
[perl #108276].
A handful of small optimizations related to character folding
and character classes in regular expressions.
Optimization of IV to UV conversions.
[perl #133677].
Speed up of the integer stringification algorithm by processing
two digits at a time instead of one.
[perl #133691].
Improvements based on LGTM analysis and recommendation.
(https://lgtm.com/projects/g/Perl/perl5/alerts/?mode=tree).
[perl #133686].
[perl #133699].
Code optimizations in regcomp.c, regcomp.h, regexec.c.
Regular expression pattern matching of things like qr/[^a]/ is
significantly sped up, where a is any ASCII character. Other classes
can get this speed up, but which ones is complicated and depends on the
underlying bit patterns of those characters, so differs between ASCII
and EBCDIC platforms, but all case pairs, like qr/[Gg]/ are included,
as is [^01].
USE_THREAD_SAFE_LOCALE.
the CPAN manpage has been upgraded from version 2.20 to 2.22.
the Data::Dumper manpage has been upgraded from version 2.170 to 2.174
the Data::Dumper manpage now avoids leaking when croaking.
OUTLIST parameters are no longer incorrectly included in the
automatically generated function prototype.
[perl #133654].
the feature manpage has been upgraded from version 1.52 to 1.54.
the File::Copy manpage has been upgraded from version 2.33 to 2.34.
the File::Find manpage has been upgraded from version 1.34 to 1.36.
$File::Find::dont_use_nlink now defaults to 1 on all
platforms.
[perl #133673].
Variables $Is_Win32 and $Is_VMS are being initialized.
Silence the Cwd manpage warning on Android builds if targetsh is not defined.
Adds support for IO::Uncompress::Zstd and
IO::Uncompress::UnLzip.
The BinModeIn and BinModeOut options are now no-ops.
ALL files will be read/written in binmode.
the JSON::PP manpage as JSON::XS 4.0 enables allow_nonref by default.
bnok() now supports the full Kronenburg extension.
[cpan #95628].
Changes to B::Op_private and Config
the Module::Load manpage has been upgraded from version 0.32 to 0.34. the Module::Metadata manpage has been upgraded from version 1.000033 to 1.000036.Properly clean up temporary directories after testing.
the NDBM_File manpage has been upgraded from version 1.14 to 1.15. the Net::Ping manpage has been upgraded from version 2.62 to 2.71. the ODBM_File manpage has been upgraded from version 1.15 to 1.16. PathTools has been upgraded from version 3.74 to 3.78. the parent manpage has been upgraded from version 0.236 to 0.237. perl5db.pl has been upgraded from version 1.54 to 1.55.Debugging threaded code no longer deadlocks in DB::sub nor
DB::lsub.
Warnings enabled by setting the WARN_ON_ERR flag in
$PerlIO::encoding::fallback are now only produced if warnings are
enabled with use warnings "utf8"; or setting $^W.
Storable no longer probes for recursion limits at build time. [perl #133708] and others.
Metasploit exploit code was included to test for CVE-2015-1992 detection, this caused anti-virus detections on at least one AV suite. The exploit code has been removed and replaced with a simple functional test. [perl #133706]
the Test::Simple manpage has been upgraded from version 1.302133 to 1.302162. the Thread::Queue manpage has been upgraded from version 3.12 to 3.13. the threads::shared manpage has been upgraded from version 1.58 to 1.60.Added support for extra tracing of locking, this requires a
-DDEBUGGING and extra compilation flags.
vars.pm no longer disables non-vars strict when checking if strict
vars is enabled.
[perl #130674].
The following modules will be removed from the core distribution in a future release, and will at that time need to be installed from CPAN. Distributions on CPAN which require these modules will need to list them as prerequisites.
The core versions of these modules will now issue "deprecated"-category
warnings to alert you to this fact. To silence these deprecation warnings,
install the modules in question from CPAN.
Note that these are (with rare exceptions) fine modules that you are encouraged to continue to use. Their disinclusion from core primarily hinges on their necessity to bootstrapping a fully functional, CPAN-capable Perl installation, not usually on concerns over their design.
B::Debug|https://metacpan.org/pod/B::Debug.
Locale::Codes has been removed at the request of its author. It
continues to be available on CPAN as
Locale::Codes|https://metacpan.org/pod/Locale::Codes
[perl #133458].
We have attempted to update the documentation to reflect the changes listed in this document. If you find any we have missed, send email to perlbug@perl.org.
AvFILL() was wrongly listed as deprecated. This has been corrected.
[perl #133278]
tr when the delimiter is an apostrophe has been clarified.
In particular, hyphens aren't special, and \x{} isn't interpolated.
[perl #130679]
reset EXPR.
Try to clarify that ref(qr/xx/) returns Regexp rather than
REGEXP and why.
[perl #133751].
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 the perldiag manpage.
\o{} without anything between the braces now yields the
fatal error message ``Empty \o{}''. Previously it was ``Number with no
digits''. This means the same wording is used for this kind of error as
with similar constructs such as \p{}.
Within the scope of the experimental feature use re 'strict',
specifying \x{} without anything between the braces now yields the
fatal error message ``Empty \x{}''. Previously it was ``Number with no
digits''. This means the same wording is used for this kind of error as
with similar constructs such as \p{}. It is legal, though not wise
to have an empty \x outside of re 'strict'; it silently generates
a NUL character.
Type of arg %d to %s must be %s (not %s)
Attempts to push, pop, etc on a hash or glob now produce this message rather than complaining that they no longer work on scalars. [perl #130367].
Prototype not terminatedThe file and line number is now reported for this error. [perl #133524]
Under-Dr (or use re 'Debug') the compiled regex engine
program is displayed. It used to use two different spellings for <
infinity >,
INFINITY, and INFTY. It now uses the latter exclusively,
as that spelling has been around the longest.
PROTOTYPES: ENABLE) would include
OUTLIST parameters, but these aren't arguments to the perl function.
This has been rectified.
[perl #133654].
-Accflags='-DUSE_THREAD_SAFE_LOCALE' option to Configure.
Improve detection of memrchr, strlcat, and strlcpy
Improve Configure detection of memmem().
[perl #133760].
Multiple improvements and fixes for -DPERL_GLOBAL_STRUCT build option.
Fix -DPERL_GLOBAL_STRUCT_PRIVATE build option.
separate error for push, etc. on hash/glob.
Add test for goto &sub in overload leaking.
pack() when compiling with HP C-ANSI-C has been fixed
by disabling optimizations in pp_pack.c.
-Duseshrplib
builds is now compatible with Mac OS X System Integrity Protection
(SIP).
SIP prevents binaries in /bin (and a few other places) being passed
the DYLD_LIBRARY_PATH environment variable. For our purposes this
prevents DYLD_LIBRARY_PATH from being passed to the shell, which
prevents that variable being passed to the testing or build process,
so running perl couldn't find libperl.dylib.
To work around that, the initial build of the perl executable expects to find libperl.dylib in the build directory, and the library path is then adjusted during installation to point to the installed library.
[perl #126706].
cuserid visible.
USE_CPLUSPLUS build option which has long been available in
win32/Makefile (for nmake) and win32/makefile.mk (for dmake) is now
also available in win32/GNUmakefile (for gmake).
The nmake makefile no longer defaults to Visual C++ 6.0 (a very old version
which is unlikely to be widely used today). As a result, it is now a
requirement to specify the CCTYPE since there is no obvious choice of which
modern version to default to instead. Failure to specify CCTYPE will result
in an error being output and the build will stop.
(The dmake and gmake makefiles will automatically detect which compiler
is being used, so do not require CCTYPE to be set. This feature has not yet
been added to the nmake makefile.)
sleep() with warnings enabled for a USE_IMP_SYS build no longer
warns about the sleep timeout being too large.
[perl #133376].
Support for compiling perl on Windows using Microsoft Visual Studio 2019
(containing Visual C++ 14.2) has been added.
socket() now sets $! if the protocol, address family and socket
type combination is not found.
[perl #133853].
The Windows Server 2003 SP1 Platform SDK build, with its early x64 compiler and
tools, was accidentally broken in Perl 5.27.9. This has now been fixed.
my_strtod in the perlapi manpage or its synonym, Strtod(), is
now available with the same signature as the libc strtod(). It provides
strotod() equivalent behavior on all platforms, using the best available
precision, depending on platform capabilities and Configure options,
while handling locale-related issues, such as if the radix character
should be a dot or comma.
Added newSVsv_nomg() to copy a SV without processing get magic on
the source.
[perl #132964].
It is now forbidden to malloc more than PTRDIFF_T_MAX bytes. Much
code (including C optimizers) assumes that all data structures will not
be larger than this, so this catches such attempts before overflow
happens.
Two new regnodes have been introduced EXACT_ONLY8, and
EXACTFU_ONLY8. They're equivalent to EXACT and EXACTFU,
except that they contain a code point which requires UTF-8 to
represent/match. Hence, if the target string isn't UTF-8, we know
it can't possibly match, without needing to try.
print_bytes_for_locale() is now defined if DEBUGGING,
Prior, it didn't get defined unless LC_COLLATE was defined
on the platform.
-DPERL_MEM_LOG and -DNO_LOCALE have been fixed.
Perl 5.28 introduced an index() optimization when comparing to -1 (or
indirectly, e.g. >= 0). When this optimization was triggered inside a when
clause it caused a warning (``Argument %s isn't numeric in smart match''). This
has now been fixed.
[perl #133368]
The new in-place editing code no longer leaks directory handles.
[perl #133314].
Warnings produced from constant folding operations on overloaded
values no longer produce spurious ``Use of uninitialized value''
warnings.
[perl #132683].
Fix for ``mutator not seen in (lex = ...) .= ...''
[perl #133441].
pack "u", "invalid uuencoding" now properly NUL terminates the
zero-length SV produced.
[perl #132655].
Improve the debugging output for calloc() calls with -Dm.
[perl #133439].
Regexp script runs were failing to permit ASCII digits in some cases.
[perl #133547].
On Unix-like systems supporting a platform-specific technique for
determining $^X, Perl failed to fall back to the
generic technique when the platform-specific one fails (for example, a Linux
system with /proc not mounted). This was a regression in Perl 5.28.0.
[perl #133573].
the SDBM_File manpage is now more robust with corrupt database files. The
improvements do not make SDBM files suitable as an interchange format.
[perl #132147].
binmode($fh); or binmode($fh, ':raw'); now properly removes the
:utf8 flag from the default :crlf I/O layer on Win32.
[perl #133604].
The experimental reference aliasing feature was misinterpreting array and
hash slice assignment as being localised, e.g.
\(@a[3,5,7]) = \(....);
was being interpreted as:
local \(@a[3,5,7]) = \(....);
[perl #133538].
sort SUBNAME within an eval EXPR when EXPR was UTF-8 upgraded
could panic if the SUBNAME was non-ASCII.
[perl #134061].
Correctly handle realloc() modifying errno on success so that the
modification isn't visible to the perl user, since realloc() is called
implicitly by the interpreter. This modification is permitted by the
C standard, but has only been observed on FreeBSD 13.0-CURRENT.
[perl #133958].
Perl now exposes POSIX getcwd as Internals::getcwd() if
available. This is intended for use by Cwd.pm during bootstrapping
and may be removed or changed without notice. This fixes some
bootstrapping issues while building perl in a directory where some
ancestor directory isn't readable.
[perl #133951].
pack() no longer can return malformed UTF-8. It croaks if it would
otherwise return a UTF-8 string that contains malformed UTF-8. This
protects against potential security threats.
[perl #131642].
See Any set of digits in the Common script are legal in a script run of another script.
Regular expression matching no longer leaves stale UTF-8 length magic
when updating $^R. This could result in length($^R) returning
an incorrect value.
Reduce recursion on ops
[perl #108276].
This can prevent stack overflow when processing extremely deep op trees.
Avoid leak in multiconcat with overloading. [perl #133789]. The handling of user-defined\p{} properties (see
User-Defined Character Properties in the perlunicode manpage) has been rewritten to
be in C (instead of Perl). This speeds things up, but in the process
several inconsistencies and bug fixes are made.
IsA() whose definition is known at compile
time, and it in turn calls isB() whose definition is not yet known.
isA() will be called each time a pattern it appears in is compiled. If
isA() also calls isC() and that definition is known, isC() will be
called just once.
There were some races and very long hangs should one thread be compiling
the same property as another simultaneously. These have now been fixed.
An EXACTFish regnode has a finite length it can hold for the string being matched. If that length is exceeded, a second node is used for the next segment of the string, for as many regnodes as are needed. Care has to be taken where to break the string, in order to deal multi-character folds in Unicode correctly. If we want to break a string at a place which could potentially be in the middle of a multi-character fold, we back off one (or more) characters, leaving a shorter EXACTFish regnode. This backing off mechanism contained an off-by-one error. [perl #133756].
A bareeof call with no previous file handle now returns true.
[perl #133721]
Failing to compile a format now aborts compilation. Like other errors
in sub-parses this could leave the parser in a strange state, possibly
crashing perl if compilation continued.
[perl #132158]
If an in-place edit is still in progress during global destruction and
the process exit code (as stored in $?) is zero, perl will now
treat the in-place edit as successful, replacing the input file with
any output produced.
This allows code like:
perl -i -ne 'print "Foo"; last'
to replace the input file, while code like:
perl -i -ne 'print "Foo"; die'
will not. Partly resolves [perl #133659].
A regression in 5.28 caused the following code to failclose(STDIN); open(CHILD, "|wc -l")'
because the child's stdin would be closed on exec. This has now been fixed.
Fixed an issue where compiling a regexp containing both compile-time and run-time code blocks could lead to trying to compile something which is invalid syntax. Fixed build failures with-DNO_LOCALE_NUMERIC and
-DNO_LOCALE_COLLATE.
[perl #133696].
Prevent the tests in ext/B/t/strict.t > from being skipped.
[perl #133713].
/di nodes ending or beginning in s are now EXACTF. We do not
want two EXACTFU to be joined together during optimization,
and to form a ss, sS, Ss or SS sequence;
they are the only multi-character sequences which may match differently
under /ui and /di.
Perl 5.30.0 represents approximately 11 months of development since Perl 5.28.0 and contains approximately 620,000 lines of changes across 1,300 files from 58 authors.
Excluding auto-generated files, documentation and release tools, there were approximately 510,000 lines of changes to 750 .pm, .t, .c and .h files.
Perl continues to flourish into its fourth decade thanks to a vibrant community of users and developers. The following people are known to have contributed the improvements that became Perl 5.30.0:
Aaron Crane, Abigail, Alberto Simões, Alexandr Savca, Andreas König, Andy Dougherty, Aristotle Pagaltzis, Brian Greenfield, Chad Granum, Chris 'BinGOs' Williams, Craig A. Berry, Dagfinn Ilmari Mannsåker, Dan Book, Dan Dedrick, Daniel Dragan, Dan Kogai, David Cantrell, David Mitchell, Dominic Hargreaves, E. Choroba, Ed J, Eugen Konkov, François Perrad, Graham Knop, Hauke D, H.Merijn Brand, Hugo van der Sanden, Jakub Wilk, James Clarke, James E Keenan, Jerry D. Hedden, Jim Cromie, John SJ Anderson, Karen Etheridge, Karl Williamson, Leon Timmermans, Matthias Bethke, Nicholas Clark, Nicolas R., Niko Tyni, Pali, Petr Písař, Phil Pearl (Lobbes), Richard Leach, Ryan Voots, Sawyer X, Shlomi Fish, Sisyphus, Slaven Rezic, Steve Hay, Sullivan Beck, Tina Müller, Tomasz Konojacki, Tom Wyant, Tony Cook, Unicode Consortium, Yves Orton, Zak B. Elep.
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 most of the (very much appreciated) contributors who reported issues to the Perl bug tracker. Noteworthy in this release were the large number of bug fixes made possible by Sergey Aleynikov's high quality perlbug reports for issues he discovered by fuzzing with AFL.
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.
If you find what you think is a bug, you might check 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 see SECURITY VULNERABILITY CONTACT INFORMATION in the perlsec manpage for details of how to report the issue.
If you wish to thank the Perl 5 Porters for the work we had done in Perl 5,
you can do so by running the perlthanks program:
perlthanks
This will send an email to the Perl 5 Porters list with your show of thanks.
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.
| perldelta - what is new for perl v5.30.0 |