perl5138delta - what is new for perl v5.13.8
This document describes differences between the 5.13.7 release and the 5.13.8 release.
If you are upgrading from an earlier release such as 5.13.6, first read perl5137delta, which describes differences between 5.13.6 and 5.13.7.
-d:-foo
Devel::foo::unimport
The syntax -d:foo was extended in 5.6.1 to make -d:foo=bar equivalent to -MDevel::foo=bar, which expands internally to use Devel::foo 'bar';. perl now allows prefixing the module name with -, with the same semantics as -M, i.e.
-d:foo
-d:foo=bar
-MDevel::foo=bar
use Devel::foo 'bar';
-
-M
Equivalent to -M-Devel::foo, expands to no Devel::foo;, calls Devel::foo->unimport() if the method exists.
-M-Devel::foo
no Devel::foo;
Devel::foo->unimport()
-d:-foo=bar
Equivalent to -M-Devel::foo=bar, expands to no Devel::foo 'bar';, calls Devel::foo->unimport('bar') if the method exists.
-M-Devel::foo=bar
no Devel::foo 'bar';
Devel::foo->unimport('bar')
This is particularly useful to suppresses the default actions of a Devel::* module's import method whilst still loading it for debugging.
Devel::*
import
When a method call on a filehandle would die because the method cannot be resolved, and IO::File has not been loaded, Perl now loads IO::File via require and attempts method resolution again:
require
open my $fh, ">", $file; $fh->binmode(":raw"); # loads IO::File and succeeds
This also works for globs like STDOUT, STDERR and STDIN:
STDOUT->autoflush(1);
Because this on-demand load only happens if method resolution fails, the legacy approach of manually loading an IO::File parent class for partial method support still works as expected:
use IO::Handle; open my $fh, ">", $file; $fh->autoflush(1); # IO::File not loaded
use feature 'unicode_strings'
This release provides full functionality for use feature 'unicode_strings'. Under its scope, all string operations executed and regular expressions compiled (even if executed outside its scope) have Unicode semantics. See feature.
This feature avoids most forms of the "Unicode Bug" (See "The "Unicode Bug"" in perlunicode for details.) If there is a possibility that your code will process Unicode strings, you are strongly encouraged to use this subpragma to avoid nasty surprises.
The availability of this should strongly affect the whole tone of various documents, such as perlunicode and perluniintro, but this work has not been done yet.
When an exception is thrown in an eval BLOCK, $@ is now set before unwinding, as well as being set after unwinding as the eval block exits. This early setting supports code that has historically treated $@ during unwinding as an indicator of whether the unwinding was due to an exception. These modules had been broken by 5.13.1's change from setting $@ early to setting it late. This double setting arrangement is a stopgap until the reason for unwinding can be made properly introspectable. $@ has never been a reliable indicator of the reason for unwinding.
eval BLOCK
$@
Perl's printf and sprintf operators, and Perl's internal printf replacement function, now understand the C90 size modifiers "hh" (char), "z" (size_t), and "t" (ptrdiff_t). Also, when compiled with a C99 compiler, Perl now understands the size modifier "j" (intmax_t).
char
size_t
ptrdiff_t
intmax_t
So, for example, on any modern machine, sprintf('%hhd', 257) returns '1'.
sprintf('%hhd', 257)
The DTrace probes now include an additional argument (arg3) which contains the package the subroutine being entered or left was compiled in.
arg3
For example using the following DTrace script:
perl$target:::sub-entry { printf("%s::%s\n", copyinstr(arg0), copyinstr(arg3)); }
and then running:
perl -e'sub test { }; test'
DTrace will print:
main::test
Multiple statement labels can now appear before a single statement.
:=
Previously my $pi := 4; was exactly equivalent to my $pi : = 4;, with the : being treated as the start of an attribute list, ending before the =. The use of := to mean : = was deprecated in 5.12.0, and is now a syntax error. This will allow the future use of := as a new token.
my $pi := 4;
my $pi : = 4;
:
=
: =
We find no Perl 5 code on CPAN using this construction, outside the core's tests for it, so we believe that this change will have very little impact on real-world codebases.
If it is absolutely necessary to have empty attribute lists (for example, because of a code generator) then avoid the error by adding a space before the =.
Code blocks in regular expressions ((?{...}) and (??{...})) used not to inherit any pragmata (strict, warnings, etc.) if the regular expression was compiled at run time as happens in cases like these two:
(?{...})
(??{...})
use re 'eval'; $foo =~ $bar; # when $bar contains (?{...}) $foo =~ /$bar(?{ $finished = 1 })/;
This was a bug, which has now been fixed. But it has the potential to break any code that was relying on this bug.
?PATTERN?
?PATTERN? (without the initial m) has been deprecated and now produces a warning. This is to allow future use of ? in new operators. The match-once functionality is still available in the form of m?PATTERN?.
?
m?PATTERN?
sv_compile_2op()
The sv_compile_2op() API function is now deprecated. Searches suggest that nothing on CPAN is using it, so this should have zero impact.
It attempted to provide an API to compile code down to an optree, but failed to bind correctly to lexicals in the enclosing scope. It's not possible to fix this problem within the constraints of its parameters and return value.
Calling a tie function (tie, tied, untie) with a scalar argument acts on a file handle if the scalar happens to hold a typeglob.
tie
tied
untie
This is a long-standing bug that will be removed in Perl 5.16, as there is currently no way to tie the scalar itself when it holds a typeglob, and no way to untie a scalar that has had a typeglob assigned to it.
This bug was fixed in 5.13.7 but, because of the breakage it caused, the fix has been reverted. Now there is a deprecation warning whenever a tie function is used on a handle without an explicit *.
*
Archive::Tar has been upgraded from version 1.72 to 1.74.
Archive::Tar
Skip extracting pax extended headers.
autodie has been upgraded from version 2.10 to 2.1001.
autodie
Test fix in blead for VMS.
B has been upgraded from version 1.26 to 1.27.
B
Avoid compiler warnings.
B::Concise has been upgraded from version 0.81 to 0.82.
B::Concise
It no longer produces mangled output with the -tree option [perl #80632].
-tree
B::Deparse has been upgraded from version 1.01 to 1.02.
B::Deparse
Test improvements.
Cwd has been upgraded from version 3.34 to 3.35.
Cwd
Data::Dumper has been upgraded from version 2.130_01 to 2.130_02.
Data::Dumper
Devel::Peek has been upgraded from version 1.05 to 1.06.
Devel::Peek
Devel::SelfStubber has been upgraded from version 1.03 to 1.05.
Devel::SelfStubber
Whitespace changes.
Digest::SHA has been upgraded from 5.48 to 5.50.
Digest::SHA
shasum now more closely mimics sha1sum/md5sum.
shasum
sha1sum
md5sum
Addfile accepts all POSIX filenames.
Addfile
Dumpvalue has been upgraded from version 1.14 to 1.15.
Dumpvalue
DynaLoader has been upgraded from version 1.11 to 1.12.
DynaLoader
Remove obsolete RCS keywords.
Env has been upgraded from version 1.01 to 1.02.
Env
ExtUtils::CBuilder has been upgraded from 0.2703 to 0.280201.
ExtUtils::CBuilder
Handle C and C++ compilers separately.
Preserves exit status on VMS.
ExtUtils::Constant::Utils has been upgraded from 0.02 to 0.03.
ExtUtils::Constant::Utils
Refactoring and fixing of backcompat code, preparing for resynchronisation with CPAN.
ExtUtils::Embed has been upgraded from 1.29 to 1.30.
ExtUtils::Embed
ExtUtils::ParseXS has been upgraded from 2.2207 to 2.2208.
ExtUtils::ParseXS
Fcntl has been upgraded from 1.10 to 1.11.
Fcntl
feature has been upgraded from 1.18 to 1.19.
feature
Documentation and test updates for the unicode_strings feature. See "Full functionality for use feature 'unicode_strings'".
unicode_strings
File::CheckTree has been upgraded from 4.4 to 4.41.
File::CheckTree
File::Glob has been upgraded from 1.10 to 1.11.
File::Glob
GDBM_File has been upgraded from 1.12 to 1.13.
GDBM_File
Hash::Util::FieldHash has been upgraded from 1.06 to 1.07.
Hash::Util::FieldHash
I18N::Collate has been upgraded from 1.01 to 1.02.
I18N::Collate
if has been upgraded from 0.06 to 0.0601.
if
IO has been upgraded from 1.25_02 to 1.25_03.
IO
IPC::Cmd has been upgraded from 0.64 to 0.66.
IPC::Cmd
Resolves an issue with splitting Win32 command lines.
Documentation enhancements.
IPC::Open3 has been upgraded from 1.07 to 1.08.
IPC::Open3
Locale::Codes has been upgraded from version 3.14 to 3.15.
Locale::Codes
Adds some codes.
Math::BigInt has been upgraded from 1.99_01 to 1.99_02.
Math::BigInt
Documentation and comment spelling fixes.
Memoize has been upgraded from version 1.01_03 to 1.02.
Memoize
MIME::Base64 has been upgraded from 3.10 to 3.13.
MIME::Base64
Now provides encode_base64url and decode_base64url functions to process the base64 scheme for "URL applications".
encode_base64url
decode_base64url
mro has been upgraded from version 1.05 to 1.06.
mro
next::method et al. now take into account that every class inherits from UNIVERSAL [perl #68654].
next::method
NDBM_File has been upgraded from 1.10 to 1.11.
NDBM_File
Net::Ping has been upgraded from 2.36 to 2.37.
Net::Ping
ODBM_File has been upgraded from 1.09 to 1.10.
ODBM_File
Opcode has been upgraded from 1.17 to 1.18.
Opcode
overload has been upgraded from 1.11 to 1.12.
overload
Avoid a taint problem in use of sprintf.
Test asymmetric fallback cases [perl #71286].
PerlIO::encoding has been upgraded from 0.13 to 0.14.
PerlIO::encoding
PerlIO::scalar has been upgraded from 0.10 to 0.11.
PerlIO::scalar
A read after a seek beyond the end of the string no longer thinks it has data to read [perl #78716].
read
seek
PerlIO::via has been upgraded from 0.10 to 0.11.
PerlIO::via
POSIX has been upgraded from 1.22 to 1.23.
POSIX
re has been upgraded from 0.14 to 0.15.
re
Enforce that /d, /u, and /l are mutually exclusive.
/d
/u
/l
SDBM_File has been upgraded from 1.08 to 1.09.
SDBM_File
Socket has been upgraded from 1.91 to 1.92.
Socket
It has several new functions for handling IPv6 addresses.
Storable has been upgraded from 2.24 to 2.25.
Storable
This adds support for serialising code references that contain UTF-8 strings correctly. The Storable minor version number changed as a result, meaning that Storable users who set $Storable::accept_future_minor to a FALSE value will see errors (see "FORWARD COMPATIBILITY" in Storable for more details).
$Storable::accept_future_minor
FALSE
Freezing no longer gets confused if the Perl stack gets reallocated during freezing [perl #80074].
threads has been upgraded from 1.81_02 to 1.81_03.
threads
threads::shared has been upgraded from 1.34 to 1.35.
threads::shared
Time::HiRes has been upgraded from 1.9721 to 1.9721_01.
Time::HiRes
Build fix in blead for VMS.
Unicode::Collate has been upgraded from 0.67 to 0.6801.
Unicode::Collate
Documentation clarification.
Unicode::Normalize has been upgraded from 1.07 to 1.08.
Unicode::Normalize
Unicode::UCD has been upgraded from 0.29 to 0.30.
Unicode::UCD
Add info about named sequence alternatives.
Don't use CompositionExclusions.txt.
CompositionExclusions.txt
version has been upgraded from 0.82 to 0.86.
version
Modify export logic for is_strict and is_lax.
is_strict
is_lax
Various backcompat fixes.
Win32 has been upgraded from 0.39 to 0.41.
Win32
Add several functions.
Corrections to names returned by Win32::GetOSName and Win32::GetOSDisplayName.
Win32::GetOSName
Win32::GetOSDisplayName
XS::APItest has been upgraded from 0.26 to 0.27.
XS::APItest
Test new API functions.
These modules were formerly distributed only in the Perl core distribution, and are now dual-lifed (meaning they are now also available separately on CPAN):
autouse
The following additions or changes have been made to diagnostic output, including warnings and fatal error messages. For the complete list of diagnostic messages, see perldiag.
There is a new "Closure prototype called" error [perl #68560].
The "Found = in conditional" warning that is emitted when a constant is assigned to a variable in a condition is now withheld if the constant is actually a subroutine or one generated by use constant, since the value of the constant may not be known at the time the program is written [perl #77762].
use constant
The Encode module can now (once again) be included in a static Perl build. The special-case handling for this situation got broken in Perl 5.11.0, and has now been repaired.
Encode
Tests for Fcntl, File::Glob, GDBM_File, IPC::Open3, NDBM_File, ODBM_File, Opcode, PerlIO::encoding, SDBM_File, and Storable now use the Test::More framework.
The NetBSD hints file has been changed to make the system's malloc the default.
The option to use an externally-supplied crypt(), or to build with no crypt() at all, has been removed. Perl supplies its own crypt() implementation for Windows, and the political situation that required this part of the distribution to sometimes be omitted is long gone.
crypt()
The mg_findext() and sv_unmagicext() functions have been added to the API. They allow extension authors to find and remove magic attached to scalars based on both the magic type and the magic virtual table, similar to how sv_magicext() attaches magic of a certain type and with a given virtual table to a scalar. This eliminates the need for extensions to walk the list of MAGIC pointers of an SV to find the magic that belongs to them.
mg_findext()
sv_unmagicext()
sv_magicext()
MAGIC
SV
The parse_fullexpr(), parse_listexpr(), parse_termexpr(), and parse_arithexpr() functions have been added to the API. They perform recursive-descent parsing of expressions at various precedence levels. They are expected to be used by syntax plugins.
parse_fullexpr()
parse_listexpr()
parse_termexpr()
parse_arithexpr()
BEGIN {require 5.12.0} now behaves as documented, rather than behaving identically to use 5.12.0;. Previously, require in a BEGIN block was erroneously executing the use feature ':5.12.0' and use strict; use warnings; behaviour, which only use was documented to provide [perl #69050].
BEGIN {require 5.12.0}
use 5.12.0;
BEGIN
use feature ':5.12.0'
use strict; use warnings;
use
use 5.42 [perl #69050], use 6 and no 5 no longer leak memory.
use 5.42
use 6
no 5
eval "BEGIN{die}" no longer leaks memory on non-threaded builds.
eval "BEGIN{die}"
PerlIO no longer crashes when called recursively, e.g., from a signal handler. Now it just leaks memory [perl #75556].
Defining a constant with the same name as one of perl's special blocks (e.g., INIT) stopped working in 5.12.0, but has now been fixed [perl #78634].
A reference to a literal value used as a hash key ($hash{\"foo"}) used to be stringified, even if the hash was tied [perl #79178].
$hash{\"foo"}
A closure containing an if statement followed by a constant or variable is no longer treated as a constant [perl #63540].
Calling a closure prototype (what is passed to an attribute handler for a closure) now results in a "Closure prototype called" error message instead of a crash [perl #68560].
A regular expression optimisation would sometimes cause a match with a {n,m} quantifier to fail when it should match [perl #79152].
{n,m}
What has become known as the "Unicode Bug" is mostly resolved in this release. Under use feature 'unicode_strings', the internal storage format of a string no longer affects the external semantics. There are two known exceptions. User-defined case changing functions, which are planned to be deprecated in 5.14, require utf8-encoded strings to function; and the character LATIN SMALL LETTER SHARP S in regular expression case-insensitive matching has a somewhat different set of bugs depending on the internal storage format. Case-insensitive matching of all characters that have multi-character matches, as this one does, is problematical in Perl. [perl #58182].
LATIN SMALL LETTER SHARP S
Mentioning a read-only lexical variable from the enclosing scope in a string eval no longer causes the variable to become writable [perl #19135].
eval
state can now be used with attributes. It used to mean the same thing as my if attributes were present [perl #68658].
state
my
Expressions like @$a > 3 no longer cause $a to be mentioned in the "Use of uninitialized value in numeric gt" warning when $a is undefined (since it is not part of the > expression, but the operand of the @) [perl #72090].
@$a > 3
$a
>
@
require no longer causes caller to return the wrong file name for the scope that called require and other scopes higher up that had the same file name [perl #68712].
caller
The ref types in the typemap for XS bindings now support magical variables [perl #72684].
Match variables (e.g., $1) no longer persist between calls to a sort subroutine [perl #76026].
$1
The B module was returning B::OPs instead of B::LOGOPs for entertry [perl #80622]. This was due to a bug in the perl core, not in B itself.
B::OP
B::LOGOP
entertry
Some numeric operators were converting integers to floating point, resulting in loss of precision on 64-bit platforms [perl #77456].
The fallback behaviour of overloading on binary operators was asymmetric [perl #71286].
Perl 5.13.8 represents approximately one month of development since Perl 5.13.7 and contains 38715 lines of changes across 546 files from 38 authors and committers.
Thank you to the following for contributing to this release:
Abhijit Menon-Sen, Abigail, Andreas König, Ben Morrow, Brad Gilbert, brian d foy, Chip Salzenberg, Chris 'BinGOs' Williams, Craig A. Berry, David Golden, David Leadbeater, David Mitchell, Father Chrysostomos, Florian Ragwitz, Goro Fuji, H.Merijn Brand, Jan Dubois, Jerry D. Hedden, Jesse Vincent, John Peacock, Karl Williamson, Lukas Mai, Marvin Humphrey, Max Maischein, Michael Breen, Michael Fig, Nicholas Clark, Nick Cleaton, Paul Evans, Peter J. Holzer, Peter John Acklam, Rafael Garcia-Suarez, Reini Urban, Renee Baecker, Ricardo Signes, Tony Cook, Yves Orton, Zefram
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 analysed by the Perl porting team.
perl -V
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 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.
To install P5re, copy and paste the appropriate command in to your terminal.
cpanm
cpanm P5re
CPAN shell
perl -MCPAN -e shell install P5re
For more information on module installation, please visit the detailed CPAN module installation guide.