perl5134delta - what is new for perl v5.13.4
This document describes differences between the 5.13.4 release and the 5.13.3 release.
If you are upgrading from an earlier release such as 5.13.2, first read perl5133delta, which describes differences between 5.13.2 and 5.13.3.
srand() now returns the seedThis allows programs that need to have repeatable results to not have to come
up with their own seed generating mechanism. Instead, they can use srand()
and somehow stash the return for future use. Typical is a test program which
has too many combinations to test comprehensively in the time available to it
each run. It can test a random subset each time, and should there be a failure,
log the seed used for that run so that it can later be used to reproduce the
exact results.
\N{name} and charnames
enhancements\N{}
, charnames::vianame
, charnames::viacode
now know about every
character in Unicode. Previously, they didn't know about the Hangul syllables
nor a number of CJK (Chinese/Japanese/Korean) characters.
Only stable releases (5.10.x, 5.12.x, 5.14.x, ...) guarantee binary
compatibility with each other, while blead releases (5.13.x, 5.15.x, ...) often
break this compatibility. However, prior to perl 5.13.4, all blead releases had
the same PERL_API_REVISION
, PERL_API_VERSION
, and PERL_API_SUBVERSION
,
effectively declaring them as binary compatible, which they weren't. From now
on, blead releases will have a PERL_API_SUBVERSION
equal to their
PERL_SUBVERSION
, explicitly marking them as incompatible with each other.
Maintenance releases of stable perl versions will continue to make no intentionally incompatible API changes.
When perl's API changes in incompatible ways (which usually happens between every major release), XS modules compiled for previous versions of perl will not work anymore. They will need to be recompiled against the new perl.
In order to ensure that modules are recompiled, and to prevent users from
accidentally loading modules compiled for old perls into newer ones, the
XS_APIVERSION_BOOTCHECK
macro has been added. That macro, which is called
when loading every newly compiled extension, compares the API version of the
running perl with the version a module has been compiled for and raises an
exception if they don't match.
Some bit fields have been reordered; therefore, this release will not be binary compatible with any previous Perl release.
Functions declared with the following prototypes now behave correctly as unary functions:
*
\sigil
\[...]
;$
;*
;\sigil
;\[...]
Due to this bug fix, functions using the (*), (;$)
and (;*)
prototypes
are parsed with higher precedence than before. So in the following example:
- sub foo($);
- foo $a < $b;
the second line is now parsed correctly as foo($a) < $b
, rather than
foo($a < $b)
. This happens when one of these operators is used in
an unparenthesised argument:
- < > <= >= lt gt le ge
- == != <=> eq ne cmp ~~
- &
- | ^
- &&
- || //
- .. ...
- ?:
- = += -= *= etc.
$[
After assignment to $[
has been deprecated and started to give warnings in
perl version 5.12.0, this version of perl also starts to emit a warning when
assigning to $[
in list context. This fixes an oversight in 5.12.0.
Make string appending 100 times faster
When doing a lot of string appending, perl could end up allocating a lot more
memory than needed in a very inefficient way, if perl was configured to use the
system's malloc
implementation instead of its own.
sv_grow
, which is what's being used to allocate more memory if necessary when
appending to a string, has now been taught how to round up the memory it
requests to a certain geometric progression, making it much faster on certain
platforms and configurations. On Win32, it's now about 100 times faster.
For weak references, the common case of just a single weak reference per referent has been optimised to reduce the storage required. In this case it saves the equivalent of one small perl array per referent.
XPV
, XPVIV
, and XPVNV
now only allocate the parts of the SV
body
they actually use, saving some space.
This release does not introduce any new modules or pragmata.
Archive::Tar
Upgraded from version 1.64 to 1.68.
Among other things, the new version adds a new option to ptar
to allow safe
creation of tarballs without world-writable files on Windows, allowing those
archives to be uploaded to CPAN.
B::Lint
Upgraded from version 1.11 to 1.12.
Carp
Upgraded from version 1.16 to 1.18.
Carp now detects incomplete caller EXPR overrides and
avoids using bogus @DB::args
. To provide backtraces, Carp relies on
particular behaviour of the caller built-in. Carp now detects if other code has
overridden this with an incomplete implementation, and modifies its backtrace
accordingly. Previously incomplete overrides would cause incorrect values in
backtraces (best case), or obscure fatal errors (worst case)
This fixes certain cases of Bizarre copy of ARRAY
caused by modules
overriding caller() incorrectly.
Compress::Raw::Bzip2
Upgraded from version 2.027 to 2.030.
Compress::Raw::Zlib
Upgraded from version 2.027 to 2.030.
File::Spec
Upgraded from version 3.31 to 3.31_01.
Various issues in File::Spec::VMS have been fixed.
I18N::Langinfo
Upgraded from version 0.03 to 0.04.
langinfo()
now defaults to using $_
if there is no argument given, just
like the documentation always claimed it did.
IO::Compress
Upgraded from version 2.027 to 2.030.
Module::CoreList
Upgraded from version 2.36 to 2.37.
Besides listing the updated core modules of this release, it also stops listing
the Filespec
module. That module never existed in core. The scripts
generating Module::CoreList
confused it with VMS::Filespec
, which actually
is a core module, since the time of perl 5.8.7.
Test::Harness
Upgraded from version 3.21 to 3.22.
Test::Simple
Upgraded from version 0.94 to 0.96.
Among many other things, subtests without a plan
or no_plan
now have an
implicit done_testing()
added to them.
Unicode::Collate
Upgraded from version 0.53 to 0.56.
Among other things, it is now using UCA Revision 20 (based on Unicode 5.2.0) and supports a couple of new locales.
feature
Upgraded from version 1.17 to 1.18.
This release does not remove any modules or pragmata.
The following existing diagnostics are now documented:
Documented a limitation of alarm SECONDS on Win32.
Minor fix to a multiple scalar match example.
Compatibility with C++
compilers has been improved.
On compilers that support it, -Wwrite-strings
is now added to cflags by
default.
t/op/print.t has been added to test implicit printing of $_
.
t/io/errnosig.t has been added to test for restoration of of $!
when
leaving signal handlers.
t/op/tie_fetch_count.t has been added to see if FETCH
is only called once
on tied variables.
lib/Tie/ExtraHash.t has been added to make sure the, previously untested, Tie::ExtraHash keeps working.
t/re/overload.t has been added to test against string corruption in pattern matches on overloaded objects. This is a TODO test.
Fixed a possible hang in t/op/readline.t.
Fixed build process for SDK2003SP1 compilers.
When using old 32-bit compilers, the define _USE_32BIT_TIME_T
will now be set
in $Config{ccflags}
. This improves portability when compiling XS extensions
using new compilers, but for a perl compiled with old 32-bit compilers.
PERL_POLLUTE
The option to define PERL_POLLUTE
to expose older 5.005 symbols for backwards
compatibility has been removed. It's use was always discouraged, and MakeMaker
contains a more specific escape hatch:
- perl Makefile.PL POLLUTE=1
This can be used for modules that have not been upgraded to 5.6 naming conventions (and really should be completely obsolete by now).
PERL_STATIC_INLINE
The PERL_STATIC_INLINE
define has been added to provide the best-guess
incantation to use for static inline functions, if the C compiler supports
C99-style static inline. If it doesn't, it'll give a plain static
.
HAS_STATIC_INLINE
can be used to check if the compiler actually supports
inline functions.
A possible memory leak when using caller EXPR to set
@DB::args
has been fixed.
Several memory leaks when loading XS modules were fixed.
A panic in the regular expression optimizer has been fixed (RT#75762).
Assignments to lvalue subroutines now honor copy-on-write behavior again, which has been broken since version 5.10.0 (RT#75656).
Assignments to glob copies now behave just like assignments to regular globs (RT#1804).
Within signal handlers, $!
is now implicitly localized.
readline EXPR now honors <>
overloading on tied
arguments.
substr EXPR,OFFSET,LENGTH,REPLACEMENT, index STR,SUBSTR,POSITION, keys HASH, and vec EXPR,OFFSET,BITS could, when used in combination with lvalues, result in leaking the scalar value they operate on, and cause its destruction to happen too late. This has now been fixed.
Building with PERL_GLOBAL_STRUCT
, which has been broken accidentally in
5.13.3, now works again.
The changes in substr EXPR,OFFSET,LENGTH,REPLACEMENT
broke HTML::Parser
<= 3.66. A fixed HTML::Parser
is available as version
3.67 on CPAN.
The changes in prototype handling break Switch
. A patch has been sent
upstream and will hopefully appear on CPAN soon.
Perl 5.13.4 represents approximately one month of development since Perl 5.13.3, and contains 91,200 lines of changes across 436 files from 34 authors and committers.
Thank you to the following for contributing to this release:
Abigail, Andy Armstrong, Andy Dougherty, Chas. Owens, Chip Salzenberg, Chris 'BinGOs' Williams, Craig A. Berry, David Cantrell, David Golden, David Mitchell, Eric Brine, Father Chrysostomos, Florian Ragwitz, George Greer, Gerard Goossen, H.Merijn Brand, James Mastros, Jan Dubois, Jerry D. Hedden, Joshua ben Jore, Karl Williamson, Lars Dɪᴇᴄᴋᴏᴡ 迪拉斯, Leon Brocard, Lubomir Rintel, Nicholas Clark, Paul Marquess, Rafael Garcia-Suarez, Reini Urban, Robin Barker, Slaven Rezic, Steve Peters, Tony Cook, Wolfram Humann, 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.
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.