perl5120delta - what is new for perl v5.12.0
This document describes differences between the 5.10.0 release and the 5.12.0 release.
Many of the bug fixes in 5.12.0 are already included in the 5.10.1 maintenance release.
You can see the list of those changes in the 5.10.1 release notes (perl5101delta).
package NAME VERSION syntaxThis new syntax allows a module author to set the $VERSION of a namespace
when the namespace is declared with 'package'. It eliminates the need
for our $VERSION = ...
and similar constructs. E.g.
- package Foo::Bar 1.23;
- # $Foo::Bar::VERSION == 1.23
There are several advantages to this:
$VERSION
is parsed in exactly the same way as use NAME VERSION
$VERSION
is set at compile time
$VERSION
is a version object that provides proper overloading of
comparison operators so comparing $VERSION
to decimal (1.23) or
dotted-decimal (v1.2.3) version numbers works correctly.
Eliminates $VERSION = ...
and eval $VERSION
clutter
As it requires VERSION to be a numeric literal or v-string
literal, it can be statically parsed by toolchain modules
without eval the way MM->parse_version does for $VERSION = ...
It does not break old code with only package NAME, but code that uses
package NAME VERSION will need to be restricted to perl 5.12.0 or newer
This is analogous to the change to open from two-args to three-args.
Users requiring the latest Perl will benefit, and perhaps after several
years, it will become a standard practice.
However, package NAME VERSION requires a new, 'strict' version
number format. See Version number formats for details.
...
operatorA new operator, ...
, nicknamed the Yada Yada operator, has been added.
It is intended to mark placeholder code that is not yet implemented.
See Yada Yada Operator in perlop.
Using the use VERSION
syntax with a version number greater or equal
to 5.11.0 will lexically enable strictures just like use strict
would do (in addition to enabling features.) The following:
- use 5.12.0;
means:
Perl 5.12 comes with Unicode 5.2, the latest version available to us at the time of release. This version of Unicode was released in October 2009. See http://www.unicode.org/versions/Unicode5.2.0 for further details about what's changed in this version of the standard. See perlunicode for instructions on installing and using other versions of Unicode.
Additionally, Perl's developers have significantly improved Perl's Unicode implementation. For full details, see Unicode overhaul below.
Perl's core time-related functions are now Y2038 compliant. (It may not mean much to you, but your kids will love it!)
It is now possible to overload the qr// operator, that is,
conversion to regexp, like it was already possible to overload
conversion to boolean, string or number of objects. It is invoked when
an object appears on the right hand side of the =~
operator or when
it is interpolated into a regexp. See overload.
Extension modules can now cleanly hook into the Perl parser to define new kinds of keyword-headed expression and compound statement. The syntax following the keyword is defined entirely by the extension. This allows a completely non-Perl sublanguage to be parsed inline, with the correct ops cleanly generated.
See PL_keyword_plugin in perlapi for the mechanism. The Perl core source distribution also includes a new module XS::APItest::KeywordRPN, which implements reverse Polish notation arithmetic via pluggable keywords. This module is mainly used for test purposes, and is not normally installed, but also serves as an example of how to use the new mechanism.
Perl's developers consider this feature to be experimental. We may remove it or change it in a backwards-incompatible way in Perl 5.14.
The lowest layers of the lexer and parts of the pad system now have C APIs available to XS extensions. These are necessary to support proper use of pluggable keywords, but have other uses too. The new APIs are experimental, and only cover a small proportion of what would be necessary to take full advantage of the core's facilities in these areas. It is intended that the Perl 5.13 development cycle will see the addition of a full range of clean, supported interfaces.
Perl's developers consider this feature to be experimental. We may remove it or change it in a backwards-incompatible way in Perl 5.14.
Where an extension module hooks the creation of rv2cv ops to modify the
subroutine lookup process, this now works correctly for bareword
subroutine calls. This means that prototypes on subroutines referenced
this way will be processed correctly. (Previously bareword subroutine
names were initially looked up, for parsing purposes, by an unhookable
mechanism, so extensions could only properly influence subroutine names
that appeared with an &
sigil.)
As of Perl 5.12.0 there is a new interface for plugging and using method resolution orders other than the default linear depth first search. The C3 method resolution order added in 5.10.0 has been re-implemented as a plugin, without changing its Perl-space interface. See perlmroapi for more information.
\N
experimental regex escapePerl now supports \N
, a new regex escape which you can think of as
the inverse of \n
. It will match any character that is not a newline,
independently from the presence or absence of the single line match
modifier /s. It is not usable within a character class. \N{3}
means to match 3 non-newlines; \N{5,}
means to match at least 5.
\N{NAME}
still means the character or sequence named NAME
, but
NAME
no longer can be things like 3
, or 5,
.
This will break a custom charnames translator which allows numbers for character names, as \N{3}
will
now mean to match 3 non-newline characters, and not the character whose
name is 3
. (No name defined by the Unicode standard is a number,
so only custom translators might be affected.)
Perl's developers are somewhat concerned about possible user confusion
with the existing \N{...}
construct which matches characters by their
Unicode name. Consequently, this feature is experimental. We may remove
it or change it in a backwards-incompatible way in Perl 5.14.
Perl now has some support for DTrace. See "DTrace support" in INSTALL.
configure_requires
in CPAN module metadataBoth CPAN
and CPANPLUS
now support the configure_requires
keyword in the META.yml metadata file included in most recent CPAN
distributions. This allows distribution authors to specify configuration
prerequisites that must be installed before running Makefile.PL
or Build.PL.
See the documentation for ExtUtils::MakeMaker
or Module::Build
for
more on how to specify configure_requires
when creating a distribution
for CPAN.
each, keys, values are now more flexibleThe each, keys, values function can now operate on arrays.
when
as a statement modifierwhen
is now allowed to be used as a statement modifier.
$,
flexibilityThe variable $,
may now be tied.
// now behaves like || in when clauses
You can now set -W
from the PERL5OPT
environment variable
delete local
delete local
now allows you to locally delete a hash entry.
Abstract namespace sockets are Linux-specific socket type that live in AF_UNIX family, slightly abusing it to be able to use arbitrary character arrays as addresses: They start with nul byte and are not terminated by nul byte, but with the length passed to the socket() system call.
The 32-bit limit on substr arguments has now been removed. The full
range of the system's signed and unsigned integers is now available for
the pos and len
arguments.
Over the years, Perl's developers have deprecated a number of language
features for a variety of reasons. Perl now defaults to issuing a
warning if a deprecated language feature is used. Many of the deprecations
Perl now warns you about have been deprecated for many years. You can
find a list of what was deprecated in a given release of Perl in the
perl5xxdelta.pod
file for that release.
To disable this feature in a given lexical scope, you should use no
warnings 'deprecated';
For information about which language features
are deprecated and explanations of various deprecation warnings, please
see perldiag. See Deprecations below for the list of features
and modules Perl's developers have deprecated as part of this release.
Acceptable version number formats have been formalized into "strict" and
"lax" rules. package NAME VERSION takes a strict version number.
UNIVERSAL::VERSION
and the version object constructors take lax
version numbers. Providing an invalid version will result in a fatal
error. The version argument in use NAME VERSION
is first parsed as a
numeric literal or v-string and then passed to UNIVERSAL::VERSION
(and must then pass the "lax" format test).
These formats are documented fully in the version module. To a first approximation, a "strict" version number is a positive decimal number (integer or decimal-fraction) without exponentiation or else a dotted-decimal v-string with a leading 'v' character and at least three components. A "lax" version number allows v-strings with fewer than three components or without a leading 'v'. Under "lax" rules, both decimal and dotted-decimal versions may have a trailing "alpha" component separated by an underscore character after a fractional or dotted-decimal component.
The version module adds version::is_strict
and version::is_lax
functions to check a scalar against these rules.
In @INC
, ARCHLIB
and PRIVLIB
now occur after the current
version's site_perl
and vendor_perl
. Modules installed into
site_perl
and vendor_perl
will now be loaded in preference to
those installed in ARCHLIB
and PRIVLIB
.
Internally, Perl now treats compiled regular expressions (such as
those created with qr//) as first class entities. Perl modules which
serialize, deserialize or otherwise have deep interaction with Perl's
internal data structures need to be updated for this change. Most
affected CPAN modules have already been updated as of this writing.
The given
/when
switch statement handles complex statements better
than Perl 5.10.0 did (These enhancements are also available in
5.10.1 and subsequent 5.10 releases.) There are two new cases where
when
now interprets its argument as a boolean, instead of an
expression to be used in a smart match:
The ..
and ...
flip-flop operators are now evaluated in boolean
context, following their usual semantics; see Range Operators in perlop.
Note that, as in perl 5.10.0, when (1..10)
will not work to test
whether a given value is an integer between 1 and 10; you should use
when ([1..10])
instead (note the array reference).
However, contrary to 5.10.0, evaluating the flip-flop operators in
boolean context ensures it can now be useful in a when()
, notably
for implementing bistable conditions, like in:
- when (/^=begin/ .. /^=end/) {
- # do something
- }
A compound expression involving the defined-or operator, as in
when (expr1 // expr2), will be treated as boolean if the first
expression is boolean. (This just extends the existing rule that applies
to the regular or operator, as in when (expr1 || expr2)
.)
Since Perl 5.10.0, Perl's developers have made a number of changes to the smart match operator. These, of course, also alter the behaviour of the switch statements where smart matching is implicitly used. These changes were also made for the 5.10.1 release, and will remain in subsequent 5.10 releases.
The smart match operator ~~
is no longer commutative. The behaviour of
a smart match now depends primarily on the type of its right hand
argument. Moreover, its semantics have been adjusted for greater
consistency or usefulness in several cases. While the general backwards
compatibility is maintained, several changes must be noted:
Code references with an empty prototype are no longer treated specially. They are passed an argument like the other code references (even if they choose to ignore it).
%hash ~~ sub {}
and @array ~~ sub {}
now test that the subroutine
returns a true value for each key of the hash (or element of the
array), instead of passing the whole hash or array as a reference to
the subroutine.
Due to the commutativity breakage, code references are no longer
treated specially when appearing on the left of the ~~
operator,
but like any vulgar scalar.
undef ~~ %hash
is always false (since undef can't be a key in a
hash). No implicit conversion to ""
is done (as was the case in perl
5.10.0).
$scalar ~~ @array
now always distributes the smart match across the
elements of the array. It's true if one element in @array verifies
$scalar ~~ $element
. This is a generalization of the old behaviour
that tested whether the array contained the scalar.
The full dispatch table for the smart match operator is given in Smart matching in detail in perlsyn.
According to the rule of dispatch based on the rightmost argument type,
when an object overloading ~~
appears on the right side of the
operator, the overload routine will always be called (with a 3rd argument
set to a true value, see overload.) However, when the object will
appear on the left, the overload routine will be called only when the
rightmost argument is a simple scalar. This way, distributivity of smart
match across arrays is not broken, as well as the other behaviours with
complex types (coderefs, hashes, regexes). Thus, writers of overloading
routines for smart match mostly need to worry only with comparing
against a scalar, and possibly with stringification overloading; the
other common cases will be automatically handled consistently.
~~
will now refuse to work on objects that do not overload it (in order
to avoid relying on the object's underlying structure). (However, if the
object overloads the stringification or the numification operators, and
if overload fallback is active, it will be used instead, as usual.)
The definitions of a number of Unicode properties have changed to match those of the current Unicode standard. These are listed above under Unicode overhaul. This change may break code that expects the old definitions.
The boolkeys op has moved to the group of hash ops. This breaks binary compatibility.
Filehandles are now always blessed into IO::File
.
The previous behaviour was to bless Filehandles into FileHandle
(an empty proxy class) if it was loaded into memory and otherwise
to bless them into IO::Handle
.
The semantics of use feature :5.10* have changed slightly.
See Modules and Pragmata for more information.
Perl's developers now use git, rather than Perforce. This should be
a purely internal change only relevant to people actively working on
the core. However, you may see minor difference in perl as a consequence
of the change. For example in some of details of the output of perl
-V
. See perlrepository for more information.
As part of the Test::Harness
2.x to 3.x upgrade, the experimental
Test::Harness::Straps
module has been removed.
See Modules and Pragmata for more details.
As part of the ExtUtils::MakeMaker
upgrade, the
ExtUtils::MakeMaker::bytes
and ExtUtils::MakeMaker::vmsish
modules
have been removed from this distribution.
Module::CoreList
no longer contains the %:patchlevel hash.
Unsupported private C API functions are now declared "static" to prevent leakage to Perl's public API.
To support the bootstrapping process, miniperl no longer builds with UTF-8 support in the regexp engine.
This allows a build to complete with PERL_UNICODE set and a UTF-8 locale. Without this there's a bootstrapping problem, as miniperl can't load the UTF-8 components of the regexp engine, because they're not yet built.
miniperl's @INC is now restricted to just -I...
, the split of
$ENV{PERL5LIB}
, and "."
A space or a newline is now required after a "#line XXX"
directive.
Tied filehandles now have an additional method EOF which provides the EOF type.
To better match all other flow control statements, foreach
may no
longer be used as an attribute.
Perl's command-line switch "-P", which was deprecated in version 5.10.0, has
now been removed. The CPAN module Filter::cpp
can be used as an
alternative.
From time to time, Perl's developers find it necessary to deprecate features or modules we've previously shipped as part of the core distribution. We are well aware of the pain and frustration that a backwards-incompatible change to Perl can cause for developers building or maintaining software in Perl. You can be sure that when we deprecate a functionality or syntax, it isn't a choice we make lightly. Sometimes, we choose to deprecate functionality or syntax because it was found to be poorly designed or implemented. Sometimes, this is because they're holding back other features or causing performance problems. Sometimes, the reasons are more complex. Wherever possible, we try to keep deprecated functionality available to developers in its previous form for at least one major release. So long as a deprecated feature isn't actively disrupting our ability to maintain and extend Perl, we'll try to leave it in place as long as possible.
The following items are now deprecated:
suidperl
is no longer part of Perl. It used to provide a mechanism to
emulate setuid permission bits on systems that don't support it properly.
:=
to mean an empty attribute list
An accident of Perl's parser meant that these constructions were all equivalent:
with the :
being treated as the start of an attribute list, which
ends before the =
. As whitespace is not significant here, all are
parsed as an empty attribute list, hence all the above are equivalent
to, and better written as
- my $pi = 4;
because no attribute processing is done for an empty list.
As is, this meant that :=
cannot be used as a new token, without
silently changing the meaning of existing code. Hence that particular
form is now deprecated, and will become a syntax error. If it is
absolutely necessary to have empty attribute lists (for example,
because of a code generator) then avoid the warning by adding a space
before the =
.
UNIVERSAL->import()
The method UNIVERSAL->import()
is now deprecated. Attempting to
pass import arguments to a use UNIVERSAL
statement will result in a
deprecation warning.
Using goto to jump from an outer scope into an inner scope is now
deprecated. This rare use case was causing problems in the
implementation of scopes.
In \N{name}, name can be just about anything. The standard
Unicode names have a very limited domain, but a custom name translator
could create names that are, for example, made up entirely of punctuation
symbols. It is now deprecated to make names that don't begin with an
alphabetic character, and aren't alphanumeric or contain other than
a very few other characters, namely spaces, dashes, parentheses
and colons. Because of the added meaning of \N
(See \N experimental regex escape), names that look like curly brace -enclosed
quantifiers won't work. For example, \N{3,4}
now means to match 3 to
4 non-newlines; before a custom name 3,4
could have been created.
The following modules will be removed from the core distribution in a future release, and should be installed from CPAN instead. Distributions on CPAN which require these should add them to their prerequisites. The core versions of these modules warnings will issue a deprecation warning.
If you ship a packaged version of Perl, either alone or as part of a
larger system, then you should carefully consider the repercussions of
core module deprecations. You may want to consider shipping your default
build of Perl with packages for some or all deprecated modules which
install into vendor
or site
perl library directories. This will
inhibit the deprecation warnings.
Alternatively, you may want to consider patching lib/deprecate.pm to provide deprecation warnings specific to your packaging system or distribution of Perl, consistent with how your packaging system or distribution manages a staged transition from a release where the installation of a single package provides the given functionality, to a later release where the system administrator needs to know to install multiple packages to get that same functionality.
You can silence these deprecation warnings by installing the modules
in question from CPAN. To install the latest version of all of them,
just install Task::Deprecations::5_12
.
Switch is buggy and should be avoided. You may find Perl's new
given
/when
feature a suitable replacement. See Switch statements in perlsyn for more information.
Perl_pmflag
is no longer part of Perl's public API. Calling it now
generates a deprecation warning, and it will be removed in a future
release. Although listed as part of the API, it was never documented,
and only ever used in toke.c, and prior to 5.10, regcomp.c. In
core, it has been replaced by a static function.
termcap.pl, tainted.pl, stat.pl, shellwords.pl, pwd.pl, open3.pl, open2.pl, newgetopt.pl, look.pl, find.pl, finddepth.pl, importenv.pl, hostname.pl, getopts.pl, getopt.pl, getcwd.pl, flush.pl, fastcwd.pl, exceptions.pl, ctime.pl, complete.pl, cacheout.pl, bigrat.pl, bigint.pl, bigfloat.pl, assert.pl, abbrev.pl, dotsh.pl, and timelocal.pl are all now deprecated. Earlier, Perl's developers intended to remove these libraries from Perl's core for the 5.14.0 release.
During final testing before the release of 5.12.0, several developers discovered current production code using these ancient libraries, some inside the Perl core itself. Accordingly, the pumpking granted them a stay of execution. They will begin to warn about their deprecation in the 5.14.0 release and will be removed in the 5.16.0 release.
Perl's developers have made a concerted effort to update Perl to be in sync with the latest Unicode standard. Changes for this include:
Perl can now handle every Unicode character property. New documentation, perluniprops, lists all available non-Unihan character properties. By default, perl does not expose Unihan, deprecated or Unicode-internal properties. See below for more details on these; there is also a section in the pod listing them, and explaining why they are not exposed.
Perl now fully supports the Unicode compound-style of using =
and :
in writing regular expressions: \p{property=value}
and
\p{property:value}
(both of which mean the same thing).
Perl now fully supports the Unicode loose matching rules for text between
the braces in \p{...}
constructs. In addition, Perl allows underscores
between digits of numbers.
Perl now accepts all the Unicode-defined synonyms for properties and property values.
qr/\X/, which matches a Unicode logical character, has
been expanded to work better with various Asian languages. It
now is defined as an extended grapheme cluster. (See
http://www.unicode.org/reports/tr29/). Anything matched previously
and that made sense will continue to be accepted. Additionally:
\X
will not break apart a CR LF
sequence.
\X
will now match a sequence which includes the ZWJ
and ZWNJ
characters.
\X
will now always match at least one character, including an initial
mark. Marks generally come after a base character, but it is possible in
Unicode to have them in isolation, and \X
will now handle that case,
for example at the beginning of a line, or after a ZWSP
. And this is
the part where \X
doesn't match the things that it used to that don't
make sense. Formerly, for example, you could have the nonsensical case
of an accented LF.
\X
will now match a (Korean) Hangul syllable sequence, and the Thai
and Lao exception cases.
Otherwise, this change should be transparent for the non-affected languages.
\p{...}
matches using the Canonical_Combining_Class property were
completely broken in previous releases of Perl. They should now work
correctly.
Before Perl 5.12, the Unicode Decomposition_Type=Compat
property
and a Perl extension had the same name, which led to neither matching
all the correct values (with more than 100 mistakes in one, and several
thousand in the other). The Perl extension has now been renamed to be
Decomposition_Type=Noncanonical
(short: dt=noncanon
). It has the
same meaning as was previously intended, namely the union of all the
non-canonical Decomposition types, with Unicode Compat
being just
one of those.
\p{Decomposition_Type=Canonical}
now includes the Hangul syllables.
\p{Uppercase}
and \p{Lowercase}
now work as the Unicode standard
says they should. This means they each match a few more characters than
they used to.
\p{Cntrl}
now matches the same characters as \p{Control}
. This
means it no longer will match Private Use (gc=co), Surrogates (gc=cs),
nor Format (gc=cf) code points. The Format code points represent the
biggest possible problem. All but 36 of them are either officially
deprecated or strongly discouraged from being used. Of those 36, likely
the most widely used are the soft hyphen (U+00AD), and BOM, ZWSP, ZWNJ,
WJ, and similar characters, plus bidirectional controls.
\p{Alpha}
now matches the same characters as \p{Alphabetic}
. Before
5.12, Perl's definition included a number of things that aren't
really alpha (all marks) while omitting many that were. The definitions
of \p{Alnum}
and \p{Word}
depend on Alpha's definition and have
changed accordingly.
\p{Word}
no longer incorrectly matches non-word characters such
as fractions.
\p{Print}
no longer matches the line control characters: Tab, LF,
CR, FF, VT, and NEL. This brings it in line with standards and the
documentation.
\p{XDigit}
now matches the same characters as \p{Hex_Digit}
. This
means that in addition to the characters it currently matches,
[A-Fa-f0-9]
, it will also match the 22 fullwidth equivalents, for
example U+FF10: FULLWIDTH DIGIT ZERO.
The Numeric type property has been extended to include the Unihan characters.
There is a new Perl extension, the 'Present_In', or simply 'In',
property. This is an extension of the Unicode Age property, but
\p{In=5.0}
matches any code point whose usage has been determined
as of Unicode version 5.0. The \p{Age=5.0}
only matches code points
added in precisely version 5.0.
A number of properties now have the correct values for unassigned code points. The affected properties are Bidi_Class, East_Asian_Width, Joining_Type, Decomposition_Type, Hangul_Syllable_Type, Numeric_Type, and Line_Break.
The Default_Ignorable_Code_Point, ID_Continue, and ID_Start properties are now up to date with current Unicode definitions.
Earlier versions of Perl erroneously exposed certain properties that are supposed to be Unicode internal-only. Use of these in regular expressions will now generate, if enabled, a deprecation warning message. The properties are: Other_Alphabetic, Other_Default_Ignorable_Code_Point, Other_Grapheme_Extend, Other_ID_Continue, Other_ID_Start, Other_Lowercase, Other_Math, and Other_Uppercase.
It is now possible to change which Unicode properties Perl understands on a per-installation basis. As mentioned above, certain properties are turned off by default. These include all the Unihan properties (which should be accessible via the CPAN module Unicode::Unihan) and any deprecated or Unicode internal-only property that Perl has never exposed.
The generated files in the lib/unicore/To
directory are now more
clearly marked as being stable, directly usable by applications. New hash
entries in them give the format of the normal entries, which allows for
easier machine parsing. Perl can generate files in this directory for
any property, though most are suppressed. You can find instructions
for changing which are written in perluniprops.
autodie
autodie
is a new lexically-scoped alternative for the Fatal
module.
The bundled version is 2.06_01. Note that in this release, using a string
eval when autodie
is in effect can cause the autodie behaviour to leak
into the surrounding scope. See BUGS in autodie for more details.
Version 2.06_01 has been added to the Perl core.
Compress::Raw::Bzip2
Version 2.024 has been added to the Perl core.
overloading
overloading
allows you to lexically disable or enable overloading
for some or all operations.
Version 0.001 has been added to the Perl core.
parent
parent
establishes an ISA relationship with base classes at compile
time. It provides the key feature of base
without further unwanted
behaviors.
Version 0.223 has been added to the Perl core.
Parse::CPAN::Meta
Version 1.40 has been added to the Perl core.
VMS::DCLsym
Version 1.03 has been added to the Perl core.
VMS::Stdio
Version 2.4 has been added to the Perl core.
XS::APItest::KeywordRPN
Version 0.003 has been added to the Perl core.
base
Upgraded from version 2.13 to 2.15.
bignum
Upgraded from version 0.22 to 0.23.
charnames
charnames
now contains the Unicode NameAliases.txt database file.
This has the effect of adding some extra \N
character names that
formerly wouldn't have been recognised; for example, "\N{LATIN CAPITAL
LETTER GHA}"
.
Upgraded from version 1.06 to 1.07.
constant
Upgraded from version 1.13 to 1.20.
diagnostics
diagnostics
now supports %.0f formatting internally.
diagnostics
no longer suppresses Use of uninitialized value in range
(or flip)
warnings. [perl #71204]
Upgraded from version 1.17 to 1.19.
feature
In feature
, the meaning of the :5.10
and :5.10.X
feature
bundles has changed slightly. The last component, if any (i.e. X
) is
simply ignored. This is predicated on the assumption that new features
will not, in general, be added to maintenance releases. So :5.10
and :5.10.X
have identical effect. This is a change to the behaviour
documented for 5.10.0.
feature
now includes the unicode_strings
feature:
- use feature "unicode_strings";
This pragma turns on Unicode semantics for the case-changing operations
(uc, lc, ucfirst, lcfirst) on strings that don't have the
internal UTF-8 flag set, but that contain single-byte characters between
128 and 255.
Upgraded from version 1.11 to 1.16.
less
less
now includes the stash_name
method to allow subclasses of
less
to pick where in %^H to store their stash.
Upgraded from version 0.02 to 0.03.
lib
Upgraded from version 0.5565 to 0.62.
mro
mro
is now implemented as an XS extension. The documented interface has
not changed. Code relying on the implementation detail that some mro::
methods happened to be available at all times gets to "keep both pieces".
Upgraded from version 1.00 to 1.02.
overload
overload
now allow overloading of 'qr'.
Upgraded from version 1.06 to 1.10.
threads
Upgraded from version 1.67 to 1.75.
threads::shared
Upgraded from version 1.14 to 1.32.
version
version
now has support for Version number formats as described
earlier in this document and in its own documentation.
Upgraded from version 0.74 to 0.82.
warnings
warnings
has a new warnings::fatal_enabled()
function. It also
includes a new illegalproto
warning category. See also New or Changed Diagnostics for this change.
Upgraded from version 1.06 to 1.09.
Archive::Extract
Upgraded from version 0.24 to 0.38.
Archive::Tar
Upgraded from version 1.38 to 1.54.
Attribute::Handlers
Upgraded from version 0.79 to 0.87.
AutoLoader
Upgraded from version 5.63 to 5.70.
B::Concise
Upgraded from version 0.74 to 0.78.
B::Debug
Upgraded from version 1.05 to 1.12.
B::Deparse
Upgraded from version 0.83 to 0.96.
B::Lint
Upgraded from version 1.09 to 1.11_01.
CGI
Upgraded from version 3.29 to 3.48.
Class::ISA
Upgraded from version 0.33 to 0.36.
NOTE: Class::ISA
is deprecated and may be removed from a future
version of Perl.
Compress::Raw::Zlib
Upgraded from version 2.008 to 2.024.
CPAN
Upgraded from version 1.9205 to 1.94_56.
CPANPLUS
Upgraded from version 0.84 to 0.90.
CPANPLUS::Dist::Build
Upgraded from version 0.06_02 to 0.46.
Data::Dumper
Upgraded from version 2.121_14 to 2.125.
DB_File
Upgraded from version 1.816_1 to 1.820.
Devel::PPPort
Upgraded from version 3.13 to 3.19.
Digest
Upgraded from version 1.15 to 1.16.
Digest::MD5
Upgraded from version 2.36_01 to 2.39.
Digest::SHA
Upgraded from version 5.45 to 5.47.
Encode
Upgraded from version 2.23 to 2.39.
Exporter
Upgraded from version 5.62 to 5.64_01.
ExtUtils::CBuilder
Upgraded from version 0.21 to 0.27.
ExtUtils::Command
Upgraded from version 1.13 to 1.16.
ExtUtils::Constant
Upgraded from version 0.2 to 0.22.
ExtUtils::Install
Upgraded from version 1.44 to 1.55.
ExtUtils::MakeMaker
Upgraded from version 6.42 to 6.56.
ExtUtils::Manifest
Upgraded from version 1.51_01 to 1.57.
ExtUtils::ParseXS
Upgraded from version 2.18_02 to 2.21.
File::Fetch
Upgraded from version 0.14 to 0.24.
File::Path
Upgraded from version 2.04 to 2.08_01.
File::Temp
Upgraded from version 0.18 to 0.22.
Filter::Simple
Upgraded from version 0.82 to 0.84.
Filter::Util::Call
Upgraded from version 1.07 to 1.08.
Getopt::Long
Upgraded from version 2.37 to 2.38.
IO
Upgraded from version 1.23_01 to 1.25_02.
IO::Zlib
Upgraded from version 1.07 to 1.10.
IPC::Cmd
Upgraded from version 0.40_1 to 0.54.
IPC::SysV
Upgraded from version 1.05 to 2.01.
Locale::Maketext
Upgraded from version 1.12 to 1.14.
Locale::Maketext::Simple
Upgraded from version 0.18 to 0.21.
Log::Message
Upgraded from version 0.01 to 0.02.
Log::Message::Simple
Upgraded from version 0.04 to 0.06.
Math::BigInt
Upgraded from version 1.88 to 1.89_01.
Math::BigInt::FastCalc
Upgraded from version 0.16 to 0.19.
Math::BigRat
Upgraded from version 0.21 to 0.24.
Math::Complex
Upgraded from version 1.37 to 1.56.
Memoize
Upgraded from version 1.01_02 to 1.01_03.
MIME::Base64
Upgraded from version 3.07_01 to 3.08.
Module::Build
Upgraded from version 0.2808_01 to 0.3603.
Module::CoreList
Upgraded from version 2.12 to 2.29.
Module::Load
Upgraded from version 0.12 to 0.16.
Module::Load::Conditional
Upgraded from version 0.22 to 0.34.
Module::Loaded
Upgraded from version 0.01 to 0.06.
Module::Pluggable
Upgraded from version 3.6 to 3.9.
Net::Ping
Upgraded from version 2.33 to 2.36.
NEXT
Upgraded from version 0.60_01 to 0.64.
Object::Accessor
Upgraded from version 0.32 to 0.36.
Package::Constants
Upgraded from version 0.01 to 0.02.
PerlIO
Upgraded from version 1.04 to 1.06.
Pod::Parser
Upgraded from version 1.35 to 1.37.
Pod::Perldoc
Upgraded from version 3.14_02 to 3.15_02.
Pod::Plainer
Upgraded from version 0.01 to 1.02.
NOTE: Pod::Plainer
is deprecated and may be removed from a future
version of Perl.
Pod::Simple
Upgraded from version 3.05 to 3.13.
Safe
Upgraded from version 2.12 to 2.22.
SelfLoader
Upgraded from version 1.11 to 1.17.
Storable
Upgraded from version 2.18 to 2.22.
Switch
Upgraded from version 2.13 to 2.16.
NOTE: Switch
is deprecated and may be removed from a future version
of Perl.
Sys::Syslog
Upgraded from version 0.22 to 0.27.
Term::ANSIColor
Upgraded from version 1.12 to 2.02.
Term::UI
Upgraded from version 0.18 to 0.20.
Test
Upgraded from version 1.25 to 1.25_02.
Test::Harness
Upgraded from version 2.64 to 3.17.
Test::Simple
Upgraded from version 0.72 to 0.94.
Text::Balanced
Upgraded from version 2.0.0 to 2.02.
Text::ParseWords
Upgraded from version 3.26 to 3.27.
Text::Soundex
Upgraded from version 3.03 to 3.03_01.
Thread::Queue
Upgraded from version 2.00 to 2.11.
Thread::Semaphore
Upgraded from version 2.01 to 2.09.
Tie::RefHash
Upgraded from version 1.37 to 1.38.
Time::HiRes
Upgraded from version 1.9711 to 1.9719.
Time::Local
Upgraded from version 1.18 to 1.1901_01.
Time::Piece
Upgraded from version 1.12 to 1.15.
Unicode::Collate
Upgraded from version 0.52 to 0.52_01.
Unicode::Normalize
Upgraded from version 1.02 to 1.03.
Win32
Upgraded from version 0.34 to 0.39.
Win32API::File
Upgraded from version 0.1001_01 to 0.1101.
XSLoader
Upgraded from version 0.08 to 0.10.
attrs
Removed from the Perl core. Prior version was 1.02.
CPAN::API::HOWTO
Removed from the Perl core. Prior version was 'undef'.
CPAN::DeferedCode
Removed from the Perl core. Prior version was 5.50.
CPANPLUS::inc
Removed from the Perl core. Prior version was 'undef'.
DCLsym
Removed from the Perl core. Prior version was 1.03.
ExtUtils::MakeMaker::bytes
Removed from the Perl core. Prior version was 6.42.
ExtUtils::MakeMaker::vmsish
Removed from the Perl core. Prior version was 6.42.
Stdio
Removed from the Perl core. Prior version was 2.3.
Test::Harness::Assert
Removed from the Perl core. Prior version was 0.02.
Test::Harness::Iterator
Removed from the Perl core. Prior version was 0.02.
Test::Harness::Point
Removed from the Perl core. Prior version was 0.01.
Test::Harness::Results
Removed from the Perl core. Prior version was 0.01.
Test::Harness::Straps
Removed from the Perl core. Prior version was 0.26_01.
Test::Harness::Util
Removed from the Perl core. Prior version was 0.01.
XSSymSet
Removed from the Perl core. Prior version was 1.1.
See Deprecated Modules above.
perlhaiku contains instructions on how to build perl for the Haiku platform.
perlmroapi describes the new interface for pluggable Method Resolution Orders.
perlperf, by Richard Foley, provides an introduction to the use of performance and optimization techniques which can be used with particular reference to perl programs.
perlrepository describes how to access the perl source using the git version control system.
perlpolicy extends the "Social contract about contributed modules" into the beginnings of a document on Perl porting policies.
The various large Changes* files (which listed every change made to perl over the last 18 years) have been removed, and replaced by a small file, also called Changes, which just explains how that same information may be extracted from the git version control system.
Porting/patching.pod has been deleted, as it mainly described interacting with the old Perforce-based repository, which is now obsolete. Information still relevant has been moved to perlrepository.
The syntax unless (EXPR) BLOCK else BLOCK is now documented as valid,
as is the syntax unless (EXPR) BLOCK elsif (EXPR) BLOCK ... else
BLOCK, although actually using the latter may not be the best idea for
the readability of your source code.
Documented -X overloading.
Documented that when()
treats specially most of the filetest operators
Documented when
as a syntax modifier.
Eliminated "Old Perl threads tutorial", which described 5005 threads.
pod/perlthrtut.pod is the same material reworked for ithreads.
Correct previous documentation: v-strings are not deprecated
With version objects, we need them to use MODULE VERSION syntax. This patch removes the deprecation notice.
Security contact information is now part of perlsec.
A significant fraction of the core documentation has been updated to clarify the behavior of Perl's Unicode handling.
Much of the remaining core documentation has been reviewed and edited for clarity, consistent use of language, and to fix the spelling of Tom Christiansen's name.
The Pod specification (perlpodspec) has been updated to bring the
specification in line with modern usage already supported by most Pod
systems. A parameter string may now follow the format name in a
"begin/end" region. Links to URIs with a text description are now
allowed. The usage of L<"section">
has been marked as
deprecated.
if.pm has been documented in use as a means to get
conditional loading of modules despite the implicit BEGIN block around
use.
The documentation for $1
in perlvar.pod has been clarified.
\N{U+code point} is now documented.
A new internal cache means that isa()
will often be faster.
The implementation of C3
Method Resolution Order has been
optimised - linearisation for classes with single inheritance is 40%
faster. Performance for multiple inheritance is unchanged.
Under use locale
, the locale-relevant information is now cached on
read-only values, such as the list returned by keys %hash
. This makes
operations such as sort keys %hash
in the scope of use locale
much faster.
Empty DESTROY
methods are no longer called.
Perl_sv_utf8_upgrade()
is now faster.
keys on empty hash is now faster.
if (%foo)
has been optimized to be faster than if (keys %foo)
.
The string repetition operator ($str x $num
) is now several times
faster when $str
has length one or $num
is large.
Reversing an array to itself (as in @a = reverse @a
) in void context
now happens in-place and is several orders of magnitude faster than
it used to be. It will also preserve non-existent elements whenever
possible, i.e. for non magical arrays or tied arrays with EXISTS
and DELETE
methods.
perlapi, perlintern, perlmodlib and perltoc are now all generated at build time, rather than being shipped as part of the release.
If vendorlib
and vendorarch
are the same, then they are only added
to @INC
once.
$Config{usedevel}
and the C-level PERL_USE_DEVEL
are now defined if
perl is built with -Dusedevel
.
Configure will enable use of -fstack-protector
, to provide protection
against stack-smashing attacks, if the compiler supports it.
Configure will now determine the correct prototypes for re-entrant
functions and for gconvert
if you are using a C++ compiler rather
than a C compiler.
On Unix, if you build from a tree containing a git repository, the
configuration process will note the commit hash you have checked out, for
display in the output of perl -v
and perl -V
. Unpushed local commits
are automatically added to the list of local patches displayed by
perl -V
.
Perl now supports SystemTap's dtrace
compatibility layer and an
issue with linking miniperl
has been fixed in the process.
perldoc now uses less -R
instead of less
for improved behaviour
in the face of groff
's new usage of ANSI escape codes.
perl -V
now reports use of the compile-time options USE_PERL_ATOF
and
USE_ATTRIBUTES_FOR_PERLIO
.
As part of the flattening of ext, all extensions on all platforms are built by make_ext.pl. This replaces the Unix-specific ext/util/make_ext, VMS-specific make_ext.com and Win32-specific win32/buildext.pl.
Each release of Perl sees numerous internal changes which shouldn't affect day to day usage but may still be notable for developers working with Perl's source code.
The J.R.R. Tolkien quotes at the head of C source file have been checked and proper citations added, thanks to a patch from Tom Christiansen.
The internal structure of the dual-life modules traditionally found in the lib/ and ext/ directories in the perl source has changed significantly. Where possible, dual-lifed modules have been extracted from lib/ and ext/.
Dual-lifed modules maintained by Perl's developers as part of the Perl core now live in dist/. Dual-lifed modules maintained primarily on CPAN now live in cpan/. When reporting a bug in a module located under cpan/, please send your bug report directly to the module's bug tracker or author, rather than Perl's bug tracker.
\N{...}
now compiles better, always forces UTF-8 internal representation
Perl's developers have fixed several problems with the recognition of
\N{...}
constructs. As part of this, perl will store any scalar
or regex containing \N{name} or \N{U+code point} in its
definition in UTF-8 format. (This was true previously for all occurrences
of \N{name} that did not use a custom translator, but now it's
always true.)
Perl_magic_setmglob now knows about globs, fixing RT #71254.
SVt_RV
no longer exists. RVs are now stored in IVs.
Perl_vcroak()
now accepts a null first argument. In addition, a full
audit was made of the "not NULL" compiler annotations, and those for
several other internal functions were corrected.
New macros dSAVEDERRNO
, dSAVE_ERRNO
, SAVE_ERRNO
, RESTORE_ERRNO
have been added to formalise the temporary saving of the errno
variable.
The function Perl_sv_insert_flags
has been added to augment
Perl_sv_insert
.
The function Perl_newSV_type(type)
has been added, equivalent to
Perl_newSV()
followed by Perl_sv_upgrade(type)
.
The function Perl_newSVpvn_flags()
has been added, equivalent to
Perl_newSVpvn()
and then performing the action relevant to the flag.
Two flag bits are currently supported.
SVf_UTF8
will call SvUTF8_on()
for you. (Note that this does
not convert an sequence of ISO 8859-1 characters to UTF-8). A wrapper,
newSVpvn_utf8()
is available for this.
SVs_TEMP
now calls Perl_sv_2mortal()
on the new SV.
There is also a wrapper that takes constant strings, newSVpvs_flags()
.
The function Perl_croak_xs_usage
has been added as a wrapper to
Perl_croak
.
Perl now exports the functions PerlIO_find_layer
and PerlIO_list_alloc
.
PL_na
has been exterminated from the core code, replaced by local
STRLEN temporaries, or *_nolen()
calls. Either approach is faster than
PL_na
, which is a pointer dereference into the interpreter structure
under ithreads, and a global variable otherwise.
Perl_mg_free()
used to leave freed memory accessible via SvMAGIC()
on the scalar. It now updates the linked list to remove each piece of
magic as it is freed.
Under ithreads, the regex in PL_reg_curpm
is now reference
counted. This eliminates a lot of hackish workarounds to cope with it
not being reference counted.
Perl_mg_magical()
would sometimes incorrectly turn on SvRMAGICAL()
.
This has been fixed.
The public IV and NV flags are now not set if the string value has trailing "garbage". This behaviour is consistent with not setting the public IV or NV flags if the value is out of range for the type.
Uses of Nullav
, Nullcv
, Nullhv
, Nullop
, Nullsv
etc have
been replaced by NULL
in the core code, and non-dual-life modules,
as NULL
is clearer to those unfamiliar with the core code.
A macro MUTABLE_PTR(p)
has been added, which on (non-pedantic) gcc will
not cast away const
, returning a void *
. Macros MUTABLE_SV(av)
,
MUTABLE_SV(cv)
etc build on this, casting to AV *
etc without
casting away const
. This allows proper compile-time auditing of
const
correctness in the core, and helped picked up some errors
(now fixed).
Macros mPUSHs()
and mXPUSHs()
have been added, for pushing SVs on the
stack and mortalizing them.
Use of the private structure mro_meta
has changed slightly. Nothing
outside the core should be accessing this directly anyway.
A new tool, Porting/expand-macro.pl has been added, that allows you to view how a C preprocessor macro would be expanded when compiled. This is handy when trying to decode the macro hell that is the perl guts.
The core distribution can now run its regression tests in parallel on
Unix-like platforms. Instead of running make test
, set TEST_JOBS
in
your environment to the number of tests to run in parallel, and run
make test_harness
. On a Bourne-like shell, this can be done as
- TEST_JOBS=3 make test_harness # Run 3 tests in parallel
An environment variable is used, rather than parallel make itself, because
TAP::Harness needs to be able to schedule individual non-conflicting test
scripts itself, and there is no standard interface to make
utilities to
interact with their job schedulers.
Note that currently some test scripts may fail when run in parallel (most
notably ext/IO/t/io_dir.t
). If necessary run just the failing scripts
again sequentially and see if the failures go away.
It's now possible to override PERL5OPT
and friends in t/TEST
Several tests that have the potential to hang forever if they fail now
incorporate a "watchdog" functionality that will kill them after a timeout,
which helps ensure that make test
and make test_harness
run to
completion automatically.
Perl's developers have added a number of new tests to the core. In addition to the items listed below, many modules updated from CPAN incorporate new tests.
Significant cleanups to core tests to ensure that language and interpreter features are not used before they're tested.
make test_porting
now runs a number of important pre-commit checks
which might be of use to anyone working on the Perl core.
t/porting/podcheck.t automatically checks the well-formedness of POD found in all .pl, .pm and .pod files in the MANIFEST, other than in dual-lifed modules which are primarily maintained outside the Perl core.
t/porting/manifest.t now tests that all files listed in MANIFEST are present.
t/op/while_readdir.t tests that a bare readdir in while loop sets $_.
t/comp/retainedlines.t checks that the debugger can retain source
lines from eval.
t/io/perlio_fail.t checks that bad layers fail.
t/io/perlio_leaks.t checks that PerlIO layers are not leaking.
t/io/perlio_open.t checks that certain special forms of open work.
t/io/perlio.t includes general PerlIO tests.
t/io/pvbm.t checks that there is no unexpected interaction between
the internal types PVBM
and PVGV
.
t/mro/package_aliases.t checks that mro works properly in the presence of aliased packages.
t/op/index_thr.t tests the interaction of index and threads.
t/op/pat_thr.t tests the interaction of esoteric patterns and threads.
t/op/qr_gc.t tests that qr doesn't leak.
t/op/reg_email_thr.t tests the interaction of regex recursion and threads.
t/op/regexp_qr_embed_thr.t tests the interaction of patterns with
embedded qr// and threads.
t/op/regexp_unicode_prop.t tests Unicode properties in regular expressions.
t/op/regexp_unicode_prop_thr.t tests the interaction of Unicode properties and threads.
t/op/reg_nc_tie.t tests the tied methods of Tie::Hash::NamedCapture
.
t/op/reg_posixcc.t checks that POSIX character classes behave consistently.
t/op/re.t checks that exportable re
functions in universal.c work.
t/op/setpgrpstack.t checks that setpgrp works.
t/op/substr_thr.t tests the interaction of substr and threads.
t/op/upgrade.t checks that upgrading and assigning scalars works.
t/uni/lex_utf8.t checks that Unicode in the lexer works.
t/uni/tie.t checks that Unicode and tie work.
t/comp/final_line_num.t tests whether line numbers are correct at EOF
t/comp/form_scope.t tests format scoping.
t/comp/line_debug.t tests whether @{"_<$file"}
works.
t/op/filetest_t.t tests if -t file test works.
t/op/qr.t tests qr.
t/op/utf8cache.t tests malfunctions of the utf8 cache.
t/re/uniprops.t test unicodes \p{}
regex constructs.
t/op/filehandle.t tests some suitably portable filetest operators to check that they work as expected, particularly in the light of some internal changes made in how filehandles are blessed.
t/op/time_loop.t tests that unix times greater than 2**63
, which
can now be handed to gmtime and localtime, do not cause an internal
overflow or an excessively long loop.
SV allocation tracing has been added to the diagnostics enabled by -Dm
.
The tracing can alternatively output via the PERL_MEM_LOG
mechanism, if
that was enabled when the perl binary was compiled.
Smartmatch resolution tracing has been added as a new diagnostic. Use
-DM
to enable it.
A new debugging flag -DB
now dumps subroutine definitions, leaving
-Dx
for its original purpose of dumping syntax trees.
Perl 5.12 provides a number of new diagnostic messages to help you write better code. See perldiag for details of these new messages.
Bad plugin affecting keyword '%s'
gmtime(%.0f) too large
Lexing code attempted to stuff non-Latin-1 character into Latin-1 input
Lexing code internal error (%s)
localtime(%.0f) too large
Overloaded dereference did not return a reference
Overloaded qr did not return a REGEXP
Perl_pmflag() is deprecated, and will be removed from the XS API
lvalue attribute ignored after the subroutine has been defined
This new warning is issued when one attempts to mark a subroutine as lvalue after it has been defined.
Perl now warns you if ++
or --
are unable to change the value
because it's beyond the limit of representation.
This uses a new warnings category: "imprecision".
Show constant in "Useless use of a constant in void context"
Prototype after '%s'
panic: sv_chop %s
This new fatal error occurs when the C routine Perl_sv_chop()
was
passed a position that is not within the scalar's string buffer. This
could be caused by buggy XS code, and at this point recovery is not
possible.
The fatal error Malformed UTF-8 returned by \N is now produced if the
charnames
handler returns malformed UTF-8.
If an unresolved named character or sequence was encountered when
compiling a regex pattern then the fatal error \N{NAME} must be resolved
by the lexer
is now produced. This can happen, for example, when using a
single-quotish context like $re = '\N{SPACE}'; /$re/;
. See perldiag
for more examples of how the lexer can get bypassed.
Invalid hexadecimal number in \N{U+...}
is a new fatal error
triggered when the character constant represented by ...
is not a
valid hexadecimal number.
The new meaning of \N
as [^\n] is not valid in a bracketed character
class, just like . in a character class loses its special meaning,
and will cause the fatal error \N in a character class must be a named
character: \N{...}.
The rules on what is legal for the ...
in \N{...}
have been
tightened up so that unless the ...
begins with an alphabetic
character and continues with a combination of alphanumerics, dashes,
spaces, parentheses or colons then the warning Deprecated character(s)
in \N{...} starting at '%s' is now issued.
The warning Using just the first characters returned by \N{}
will
be issued if the charnames
handler returns a sequence of characters
which exceeds the limit of the number of characters that can be used. The
message will indicate which characters were used and which were discarded.
A number of existing diagnostic messages have been improved or corrected:
A new warning category illegalproto
allows finer-grained control of
warnings around function prototypes.
The two warnings:
have been moved from the syntax
top-level warnings category into a new
first-level category, illegalproto
. These two warnings are currently
the only ones emitted during parsing of an invalid/illegal prototype,
so one can now use
- no warnings 'illegalproto';
to suppress only those, but not other syntax-related warnings. Warnings
where prototypes are changed, ignored, or not met are still in the
prototype category as before.
Deep recursion on subroutine "%s"
It is now possible to change the depth threshold for this warning from the
default of 100, by recompiling the perl binary, setting the C
pre-processor macro PERL_SUB_DEPTH_WARN
to the desired value.
Illegal character in prototype
warning is now more precise
when reporting illegal characters after _
mro merging error messages are now very similar to those produced by Algorithm::C3.
Amelioration of the error message "Unrecognized character %s in column %d"
Changes the error message to "Unrecognized character %s; marked by <-- HERE after %s<-- HERE near column %d". This should make it a little simpler to spot and correct the suspicious character.
Perl now explicitly points to $.
when it causes an uninitialized
warning for ranges in scalar context.
split now warns when called in void context.
printf-style functions called with too few arguments will now issue the
warning "Missing argument in %s"
[perl #71000]
Perl now properly returns a syntax error instead of segfaulting
if each, keys, or values is used without an argument.
tell() now fails properly if called without an argument and when no
previous file was read.
tell() now returns -1
, and sets errno to EBADF
, thus restoring
the 5.8.x behaviour.
overload
no longer implicitly unsets fallback on repeated 'use
overload' lines.
POSIX::strftime() can now handle Unicode characters in the format string.
The syntax
category was removed from 5 warnings that should only be in
deprecated
.
Three fatal pack/unpack error messages have been normalized to
panic: %s
Unicode character is illegal
has been rephrased to be more accurate
It now reads Unicode non-character is illegal in interchange
and the
perldiag documentation has been expanded a bit.
Currently, all but the first of the several characters that the
charnames
handler may return are discarded when used in a regular
expression pattern bracketed character class. If this happens then the
warning Using just the first character returned by \N{} in character
class
will be issued.
The warning Missing right brace on \N{} or unescaped left brace after
\N. Assuming the latter
will be issued if Perl encounters a \N{
but doesn't find a matching }. In this case Perl doesn't know if it
was mistakenly omitted, or if "match non-newline" followed by "match
a {" was desired. It assumes the latter because that is actually a
valid interpretation as written, unlike the other case. If you meant
the former, you need to add the matching right brace. If you did mean
the latter, you can silence this warning by writing instead \N\{.
gmtime and localtime called with numbers smaller than they can
reliably handle will now issue the warnings gmtime(%.0f) too small
and localtime(%.0f) too small.
The following diagnostic messages have been removed:
Runaway format
Can't locate package %s for the parents of %s
In general this warning it only got produced in conjunction with other warnings, and removing it allowed an ISA lookup optimisation to be added.
v-string in use/require is non-portable
h2ph now looks in include-fixed
too, which is a recent addition
to gcc's search path.
h2xs no longer incorrectly treats enum values like macros.
It also now handles C++ style comments (//
) properly in enums.
perl5db.pl now supports LVALUE
subroutines. Additionally, the
debugger now correctly handles proxy constant subroutines, and
subroutine stubs.
perlbug now uses %Module::CoreList::bug_tracker
to print out
upstream bug tracker URLs. If a user identifies a particular module
as the topic of their bug report and we're able to divine the URL for
its upstream bug tracker, perlbug now provide a message to the user
explaining that the core copies the CPAN version directly, and provide
the URL for reporting the bug directly to the upstream author.
perlbug no longer reports "Message sent" when it hasn't actually sent the message
perlthanks is a new utility for sending non-bug-reports to the authors and maintainers of Perl. Getting nothing but bug reports can become a bit demoralising. If Perl 5.12 works well for you, please try out perlthanks. It will make the developers smile.
Perl's developers have fixed bugs in a2p having to do with the
match()
operator in list context. Additionally, a2p no longer
generates code that uses the $[
variable.
U+0FFFF is now a legal character in regular expressions.
pp_qr now always returns a new regexp SV. Resolves RT #69852.
Instead of returning a(nother) reference to the (pre-compiled) regexp in the optree, use reg_temp_copy() to create a copy of it, and return a reference to that. This resolves issues about Regexp::DESTROY not being called in a timely fashion (the original bug tracked by RT #69852), as well as bugs related to blessing regexps, and of assigning to regexps, as described in correspondence added to the ticket.
It transpires that we also need to undo the SvPVX() sharing when ithreads cloning a Regexp SV, because mother_re is set to NULL, instead of a cloned copy of the mother_re. This change might fix bugs with regexps and threads in certain other situations, but as yet neither tests nor bug reports have indicated any problems, so it might not actually be an edge case that it's possible to reach.
Several compilation errors and segfaults when perl was built with -Dmad
were fixed.
Fixes for lexer API changes in 5.11.2 which broke NYTProf's savesrc option.
-t
should only return TRUE for file handles connected to a TTY
The Microsoft C version of isatty()
returns TRUE for all character mode
devices, including the /dev/null-style "nul" device and printers like
"lpt1".
Fixed a regression caused by commit fafafbaf which caused a panic during parameter passing [perl #70171]
On systems which in-place edits without backup files, -i'*' now works as the documentation says it does [perl #70802]
Saving and restoring magic flags no longer loses readonly flag.
The malformed syntax grep EXPR LIST
(note the missing comma) no longer
causes abrupt and total failure.
Regular expressions compiled with qr{} literals properly set $'
when
matching again.
Using named subroutines with sort should no longer lead to bus errors
[perl #71076]
Numerous bugfixes catch small issues caused by the recently-added Lexer API.
Smart match against @_
sometimes gave false negatives. [perl #71078]
$@
may now be assigned a read-only value (without error or busting
the stack).
sort called recursively from within an active comparison subroutine no
longer causes a bus error if run multiple times. [perl #71076]
Tie::Hash::NamedCapture::* will not abort if passed bad input (RT #71828)
@_ and $_ no longer leak under threads (RT #34342 and #41138, also #70602, #70974)
-I
on shebang line now adds directories in front of @INC
as documented, and as does -I
when specified on the command-line.
kill is now fatal when called on non-numeric process identifiers.
Previously, an undef process identifier would be interpreted as a
request to kill process 0, which would terminate the current process
group on POSIX systems. Since process identifiers are always integers,
killing a non-numeric process is now fatal.
5.10.0 inadvertently disabled an optimisation, which caused a measurable
performance drop in list assignment, such as is often used to assign
function parameters from @_
. The optimisation has been re-instated, and
the performance regression fixed. (This fix is also present in 5.10.1)
Fixed memory leak on while (1) { map 1, 1 }
[RT #53038].
Some potential coredumps in PerlIO fixed [RT #57322,54828].
The debugger now works with lvalue subroutines.
The debugger's m command was broken on modules that defined constants
[RT #61222].
crypt and string complement could return tainted values for untainted
arguments [RT #59998].
The -i
.suffix command-line switch now recreates the file using
restricted permissions, before changing its mode to match the original
file. This eliminates a potential race condition [RT #60904].
On some Unix systems, the value in $?
would not have the top bit set
($? & 128
) even if the child core dumped.
Under some circumstances, $^R
could incorrectly become undefined
[RT #57042].
In the XS API, various hash functions, when passed a pre-computed hash where the key is UTF-8, might result in an incorrect lookup.
XS code including XSUB.h before perl.h gave a compile-time error [RT #57176].
$object->isa('Foo')
would report false if the package Foo
didn't exist, even if the object's @ISA
contained Foo
.
Various bugs in the new-to 5.10.0 mro code, triggered by manipulating
@ISA
, have been found and fixed.
Bitwise operations on references could crash the interpreter, e.g.
$x=\$y; $x |= "foo"
[RT #54956].
Patterns including alternation might be sensitive to the internal UTF-8 representation, e.g.
Within UTF8-encoded Perl source files (i.e. where use utf8
is in
effect), double-quoted literal strings could be corrupted where a \xNN
,
\0NNN or \N{}
is followed by a literal character with ordinal value
greater than 255 [RT #59908].
B::Deparse
failed to correctly deparse various constructs:
readpipe STRING
[RT #62428], CORE::require(STRING)
[RT #62488],
sub foo(_)
[RT #62484].
Using setpgrp with no arguments could corrupt the perl stack.
The block form of eval is now specifically trappable by Safe
and
ops
. Previously it was erroneously treated like string eval.
In 5.10.0, the two characters [~ were sometimes parsed as the smart
match operator (~~
) [RT #63854].
In 5.10.0, the *
quantifier in patterns was sometimes treated as
{0,32767}
[RT #60034, #60464]. For example, this match would fail:
- ("ab" x 32768) =~ /^(ab)*$/
shmget was limited to a 32 bit segment size on a 64 bit OS [RT #63924].
Using next or last to exit a given
block no longer produces a
spurious warning like the following:
- Exiting given via last at foo.pl line 123
Assigning a format to a glob could corrupt the format; e.g.:
- *bar=*foo{FORMAT}; # foo format now bad
Attempting to coerce a typeglob to a string or number could cause an
assertion failure. The correct error message is now generated,
Can't coerce GLOB to $type.
Under use filetest 'access'
, -x
was using the wrong access
mode. This has been fixed [RT #49003].
length on a tied scalar that returned a Unicode value would not be
correct the first time. This has been fixed.
Using an array tie inside in array tie could SEGV. This has been
fixed. [RT #51636]
A race condition inside PerlIOStdio_close()
has been identified and
fixed. This used to cause various threading issues, including SEGVs.
In unpack, the use of ()
groups in scalar context was internally
placing a list on the interpreter's stack, which manifested in various
ways, including SEGVs. This is now fixed [RT #50256].
Magic was called twice in substr, \&$x
, tie $x, $m
and chop.
These have all been fixed.
A 5.10.0 optimisation to clear the temporary stack within the implicit
loop of s///ge has been reverted, as it turned out to be the cause of
obscure bugs in seemingly unrelated parts of the interpreter [commit
ef0d4e17921ee3de].
The line numbers for warnings inside elsif
are now correct.
The ..
operator now works correctly with ranges whose ends are at or
close to the values of the smallest and largest integers.
binmode STDIN, ':raw'
could lead to segmentation faults on some platforms.
This has been fixed [RT #54828].
An off-by-one error meant that index $str, ...
was effectively being
executed as index "$str\0", ...
. This has been fixed [RT #53746].
Various leaks associated with named captures in regexes have been fixed [RT #57024].
A weak reference to a hash would leak. This was affecting DBI
[RT #56908].
Using (?|) in a regex could cause a segfault [RT #59734].
Use of a UTF-8 tr// within a closure could cause a segfault [RT #61520].
Calling Perl_sv_chop()
or otherwise upgrading an SV could result in an
unaligned 64-bit access on the SPARC architecture [RT #60574].
In the 5.10.0 release, inc_version_list
would incorrectly list
5.10.*
after 5.8.*
; this affected the @INC
search order
[RT #67628].
In 5.10.0, pack "a*", $tainted_value
returned a non-tainted value
[RT #52552].
In 5.10.0, printf and sprintf could produce the fatal error
panic: utf8_mg_pos_cache_update
when printing UTF-8 strings
[RT #62666].
In the 5.10.0 release, a dynamically created AUTOLOAD
method might be
missed (method cache issue) [RT #60220,60232].
In the 5.10.0 release, a combination of use feature
and //ee could
cause a memory leak [RT #63110].
-C
on the shebang (#!
) line is once more permitted if it is also
specified on the command line. -C
on the shebang line used to be a
silent no-op if it was not also on the command line, so perl 5.10.0
disallowed it, which broke some scripts. Now perl checks whether it is
also on the command line and only dies if it is not [RT #67880].
In 5.10.0, certain types of re-entrant regular expression could crash, or cause the following assertion failure [RT #60508]:
- Assertion rx->sublen >= (s - rx->subbeg) + i failed
Perl now includes previously missing files from the Unicode Character Database.
Perl now honors TMPDIR
when opening an anonymous temporary file.
Perl is incredibly portable. In general, if a platform has a C compiler, someone has ported Perl to it (or will soon). We're happy to announce that Perl 5.12 includes support for several new platforms. At the same time, it's time to bid farewell to some (very) old friends.
Perl's developers have merged patches from Haiku's maintainers. Perl should now build on Haiku.
Perl should now build on MirOS BSD.
Removed libbsd for AIX 5L and 6.1. Only flock() was used from
libbsd.
Removed libgdbm for AIX 5L and 6.1 if libgdbm < 1.8.3-5 is installed. The libgdbm is delivered as an optional package with the AIX Toolbox. Unfortunately the versions below 1.8.3-5 are broken.
Hints changes mean that AIX 4.2 should work again.
Perl now supports IPv6 on Cygwin 1.7 and newer.
On Cygwin we now strip the last number from the DLL. This has been the behaviour in the cygwin.com build for years. The hints files have been updated.
Skip testing the be_BY.CP1131 locale on Darwin 10 (Mac OS X 10.6), as it's still buggy.
Correct infelicities in the regexp used to identify buggy locales on Darwin 8 and 9 (Mac OS X 10.4 and 10.5, respectively).
Fix thread library selection [perl #69686]
The hints files now identify the correct threading libraries on FreeBSD 7 and later.
We now work around a bizarre preprocessor bug in the Irix 6.5 compiler:
cc -E -
unfortunately goes into K&R mode, but cc -E file.c
doesn't.
Hints now supports versions 5.*.
-UDEBUGGING
is now the default on VMS.
Like it has been everywhere else for ages and ages. Also make command-line selection of -UDEBUGGING and -DDEBUGGING work in configure.com; before the only way to turn it off was by saying no in answer to the interactive question.
The default pipe buffer size on VMS has been updated to 8192 on 64-bit systems.
Reads from the in-memory temporary files of PerlIO::scalar
used to fail
if $/
was set to a numeric reference (to indicate record-style reads).
This is now fixed.
VMS now supports getgrgid.
Many improvements and cleanups have been made to the VMS file name handling and conversion code.
Enabling the PERL_VMS_POSIX_EXIT
logical name now encodes a POSIX exit
status in a VMS condition value for better interaction with GNV's bash
shell and other utilities that depend on POSIX exit values. See
$? in perlvms for details.
File::Copy
now detects Unix compatibility mode on VMS.
Various changes from Stratus have been merged in.
There is now support for Symbian S60 3.2 SDK and S60 5.0 SDK.
Perl 5.12 supports Windows 2000 and later. The supporting code for legacy versions of Windows is still included, but will be removed during the next development cycle.
Initial support for building Perl with MinGW-w64 is now available.
perl.exe now includes a manifest resource to specify the trustInfo
settings for Windows Vista and later. Without this setting Windows
would treat perl.exe as a legacy application and apply various
heuristics like redirecting access to protected file system areas
(like the "Program Files" folder) to the users "VirtualStore"
instead of generating a proper "permission denied" error.
The manifest resource also requests the Microsoft Common-Controls version 6.0 (themed controls introduced in Windows XP). Check out the Win32::VisualStyles module on CPAN to switch back to old style unthemed controls for legacy applications.
The -t
filetest operator now only returns true if the filehandle
is connected to a console window. In previous versions of Perl it
would return true for all character mode devices, including NUL
and LPT1.
The -p
filetest operator now works correctly, and the
Fcntl::S_IFIFO constant is defined when Perl is compiled with
Microsoft Visual C. In previous Perl versions -p
always
returned a false value, and the Fcntl::S_IFIFO constant
was not defined.
This bug is specific to Microsoft Visual C and never affected Perl binaries built with MinGW.
The socket error codes are now more widely supported: The POSIX module will define the symbolic names, like POSIX::EWOULDBLOCK, and stringification of socket error codes in $! works as well now;
- C:\>perl -MPOSIX -E "$!=POSIX::EWOULDBLOCK; say $!"
- A non-blocking socket operation could not be completed immediately.
flock() will now set sensible error codes in $!. Previous Perl versions copied the value of $^E into $!, which caused much confusion.
select() now supports all empty fd_set
s more correctly.
'.\foo'
and '..\foo'
were treated differently than
'./foo'
and '../foo'
by do and require [RT #63492].
Improved message window handling means that alarm and kill messages
will no longer be dropped under race conditions.
Various bits of Perl's build infrastructure are no longer converted to win32 line endings at release time. If this hurts you, please report the problem with the perlbug program included with perl.
This is a list of some significant unfixed bugs, which are regressions from either 5.10.x or 5.8.x.
Some CPANPLUS tests may fail if there is a functioning file ../../cpanp-run-perl outside your build directory. The failure shouldn't imply there's a problem with the actual functional software. The bug is already fixed in [RT #74188] and is scheduled for inclusion in perl-v5.12.1.
List::Util::first
misbehaves in the presence of a lexical $_
(typically introduced by my $_
or implicitly by given
). The variable
which gets set for each iteration is the package variable $_
, not the
lexical $_
[RT #67694].
A similar issue may occur in other modules that provide functions which take a block as their first argument, like
- foo { ... $_ ...} list
Some regexes may run much more slowly when run in a child thread compared with the thread the pattern was compiled into [RT #55600].
Things like "\N{LATIN SMALL LIGATURE FF}" =~ /\N{LATIN SMALL LETTER F}+/
will appear to hang as they get into a very long running loop [RT #72998].
Several porters have reported mysterious crashes when Perl's entire test suite is run after a build on certain Windows 2000 systems. When run by hand, the individual tests reportedly work fine.
This one is actually a change introduced in 5.10.0, but it was missed from that release's perldelta, so it is mentioned here instead.
A bugfix related to the handling of the /m modifier and qr resulted
in a change of behaviour between 5.8.x and 5.10.0:
- # matches in 5.8.x, doesn't match in 5.10.0
- $re = qr/^bar/; "foo\nbar" =~ /$re/m;
Perl 5.12.0 represents approximately two years of development since Perl 5.10.0 and contains over 750,000 lines of changes across over 3,000 files from over 200 authors and committers.
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 5.12.0:
Aaron Crane, Abe Timmerman, Abhijit Menon-Sen, Abigail, Adam Russell, Adriano Ferreira, Ævar Arnfjörð Bjarmason, Alan Grover, Alexandr Ciornii, Alex Davies, Alex Vandiver, Andreas Koenig, Andrew Rodland, andrew@sundale.net, Andy Armstrong, Andy Dougherty, Jose AUGUSTE-ETIENNE, Benjamin Smith, Ben Morrow, bharanee rathna, Bo Borgerson, Bo Lindbergh, Brad Gilbert, Bram, Brendan O'Dea, brian d foy, Charles Bailey, Chip Salzenberg, Chris 'BinGOs' Williams, Christoph Lamprecht, Chris Williams, chromatic, Claes Jakobsson, Craig A. Berry, Dan Dascalescu, Daniel Frederick Crisman, Daniel M. Quinlan, Dan Jacobson, Dan Kogai, Dave Mitchell, Dave Rolsky, David Cantrell, David Dick, David Golden, David Mitchell, David M. Syzdek, David Nicol, David Wheeler, Dennis Kaarsemaker, Dintelmann, Peter, Dominic Dunlop, Dr.Ruud, Duke Leto, Enrico Sorcinelli, Eric Brine, Father Chrysostomos, Florian Ragwitz, Frank Wiegand, Gabor Szabo, Gene Sullivan, Geoffrey T. Dairiki, George Greer, Gerard Goossen, Gisle Aas, Goro Fuji, Graham Barr, Green, Paul, Hans Dieter Pearcey, Harmen, H. Merijn Brand, Hugo van der Sanden, Ian Goodacre, Igor Sutton, Ingo Weinhold, James Bence, James Mastros, Jan Dubois, Jari Aalto, Jarkko Hietaniemi, Jay Hannah, Jerry Hedden, Jesse Vincent, Jim Cromie, Jody Belka, John E. Malmberg, John Malmberg, John Peacock, John Peacock via RT, John P. Linderman, John Wright, Josh ben Jore, Jos I. Boumans, Karl Williamson, Kenichi Ishigaki, Ken Williams, Kevin Brintnall, Kevin Ryde, Kurt Starsinic, Leon Brocard, Lubomir Rintel, Luke Ross, Marcel Grünauer, Marcus Holland-Moritz, Mark Jason Dominus, Marko Asplund, Martin Hasch, Mashrab Kuvatov, Matt Kraai, Matt S Trout, Max Maischein, Michael Breen, Michael Cartmell, Michael G Schwern, Michael Witten, Mike Giroux, Milosz Tanski, Moritz Lenz, Nicholas Clark, Nick Cleaton, Niko Tyni, Offer Kaye, Osvaldo Villalon, Paul Fenwick, Paul Gaborit, Paul Green, Paul Johnson, Paul Marquess, Philip Hazel, Philippe Bruhat, Rafael Garcia-Suarez, Rainer Tammer, Rajesh Mandalemula, Reini Urban, Renée Bäcker, Ricardo Signes, Ricardo SIGNES, Richard Foley, Rich Rauenzahn, Rick Delaney, Risto Kankkunen, Robert May, Roberto C. Sanchez, Robin Barker, SADAHIRO Tomoyuki, Salvador Ortiz Garcia, Sam Vilain, Scott Lanning, Sébastien Aperghis-Tramoni, Sérgio Durigan Júnior, Shlomi Fish, Simon 'corecode' Schubert, Sisyphus, Slaven Rezic, Smylers, Steffen Müller, Steffen Ullrich, Stepan Kasal, Steve Hay, Steven Schubiger, Steve Peters, Tels, The Doctor, Tim Bunce, Tim Jenness, Todd Rinaldo, Tom Christiansen, Tom Hukins, Tom Wyant, Tony Cook, Torsten Schoenfeld, Tye McQueen, Vadim Konovalov, Vincent Pit, Hio YAMASHINA, Yasuhiro Matsumoto, Yitzchak Scott-Thoennes, Yuval Kogman, Yves Orton, Zefram, Zsban Ambrus
This is woefully incomplete as it's automatically generated from version
control history. In particular, it doesn't include the names of the
(very much appreciated) contributors who reported issues in previous
versions of Perl that helped make Perl 5.12.0 better. For a more complete
list of all of Perl's historical contributors, please see the AUTHORS
file in the Perl 5.12.0 distribution.
Our "retired" pumpkings Nicholas Clark and Rafael Garcia-Suarez deserve special thanks for their brilliant and substantive ongoing contributions. Nicholas personally authored over 30% of the patches since 5.10.0. Rafael comes in second in patch authorship with 11%, but is first by a long shot in committing patches authored by others, pushing 44% of the commits since 5.10.0 in this category, often after providing considerable coaching to the patch authors. These statistics in no way comprise all of their contributions, but express in shorthand that we couldn't have done it without them.
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.
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 http://rt.perl.org/perlbug/. 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
analyzed 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.
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.
http://dev.perl.org/perl5/errata.html for a list of issues found after this release, as well as a list of CPAN modules known to be incompatible with this release.