perl5240delta - what is new for perl v5.24.0
This document describes the differences between the 5.22.0 release and the 5.24.0 release.
Using the postderef
and postderef_qq
features no longer emits a
warning. Existing code that disables the experimental::postderef
warning
category that they previously used will continue to work. The postderef
feature has no effect; all Perl code can use postfix dereferencing,
regardless of what feature declarations are in scope. The 5.24
feature
bundle now includes the postderef_qq
feature.
For details on what is in this release, see http://www.unicode.org/versions/Unicode8.0.0/.
Until now, failure to close the output file for an in-place edit was not detected, meaning that the input file could be clobbered without the edit being successfully completed. Now, when the output file cannot be closed successfully, an exception is raised.
\b{lb}
boundary in regular expressionslb
stands for Line Break. It is a Unicode property
that determines where a line of text is suitable to break (typically so
that it can be output without overflowing the available horizontal
space). This capability has long been furnished by the
Unicode::LineBreak module, but now a light-weight, non-customizable
version that is suitable for many purposes is in core Perl.
qr/(?[ ])/
now works in UTF-8 localesExtended Bracketed Character Classes
now will successfully compile when use locale
is in effect. The compiled
pattern will use standard Unicode rules. If the runtime locale is not a
UTF-8 one, a warning is raised and standard Unicode rules are used
anyway. No tainting is done since the outcome does not actually depend
on the locale.
<<
and >>
) now more explicitly definedNegative shifts are reverse shifts: left shift becomes right shift, and right shift becomes left shift.
Shifting by the number of bits in a native integer (or more) is zero,
except when the "overshift" is right shifting a negative value under
use integer
, in which case the result is -1 (arithmetic shift).
Until now negative shifting and overshifting have been undefined because they have relied on whatever the C implementation happens to do. For example, for the overshift a common C behavior is "modulo shift":
- 1 >> 64 == 1 >> (64 % 64) == 1 >> 0 == 1 # Common C behavior.
- # And the same for <<, while Perl now produces 0 for both.
Now these behaviors are well-defined under Perl, regardless of what the underlying C implementation does. Note, however, that you are still constrained by the native integer width: you need to know how far left you can go. You can use for example:
If you need a more bits on the left shift, you can use for example
the bigint
pragma, or the Bit::Vector
module from CPAN.
That is, sprintf '|%.*2$d|', 2, 3
now returns |002|
. This extends
the existing reordering mechanism (which allows reordering for arguments
that are used as format fields, widths, and vector separators).
sigaction
callback with SA_SIGINFO
When passing the SA_SIGINFO
flag to sigaction, the
errno
, status
, uid
, pid
, addr
and band
fields are now
included in the hash passed to the handler, if supported by the
platform.
Previously perl would redirect to another interpreter if it found a hashbang path unless the path contains "perl" (see perlrun). To improve compatability with Perl 6 this behavior has been extended to also redirect if "perl" is followed by "6".
mkstemp(3)
In 5.22 perl started setting umask to 0600 before calling mkstemp(3)
and restoring it afterwards. This wrongfully tells open(2)
to strip
the owner read and write bits from the given mode before applying it,
rather than the intended negation of leaving only those bits in place.
Systems that use mode 0666 in mkstemp(3)
(like old versions of
glibc) create a file with permissions 0066, leaving world read and
write permissions regardless of current umask.
This has been fixed by using umask 0177 instead. [perl #127322]
This is CVE-2015-8608. For more information see [perl #126755]
This is CVE-2015-8607. For more information see [perl #126862]
crypt()
Added validation that will detect both a short salt and invalid characters in the salt. [perl #126922]
environ
Previously, if an environment variable appeared more than once in
environ[]
, %ENV
would contain the last entry for that name,
while a typical getenv()
would return the first entry. We now
make sure %ENV
contains the same as what getenv
returns.
Second, we remove duplicates from environ[]
, so if a setting
with that name is set in %ENV
, we won't pass an unsafe value
to a child process.
[CVE-2016-2381]
autoderef
feature has been removedThe experimental autoderef
feature (which allowed calling push
,
pop
, shift
, unshift
, splice
, keys
, values
, and each
on
a scalar argument) has been deemed unsuccessful. It has now been removed;
trying to use the feature (or to disable the experimental::autoderef
warning it previously triggered) now yields an exception.
my $_
was introduced in Perl 5.10, and subsequently caused much confusion
with no obvious solution. In Perl 5.18.0, it was made experimental on the
theory that it would either be removed or redesigned in a less confusing (but
backward-incompatible) way. Over the following years, no alternatives were
proposed. The feature has now been removed and will fail to compile.
qr/\b{wb}/
is now tailored to Perl expectationsThis is now more suited to be a drop-in replacement for plain \b
, but
giving better results for parsing natural language. Previously it
strictly followed the current Unicode rules which calls for it to match
between each white space character. Now it doesn't generally match
within spans of white space, behaving like \b
does. See
\b{wb} in perlrebackslash
Some regular expression patterns that had runtime errors now don't compile at all.
Almost all Unicode properties using the \p{}
and \P{}
regular
expression pattern constructs are now checked for validity at pattern
compilation time, and invalid ones will cause the program to not
compile. In earlier releases, this check was often deferred until run
time. Whenever an error check is moved from run- to compile time,
erroneous code is caught 100% of the time, whereas before it would only
get caught if and when the offending portion actually gets executed,
which for unreachable code might be never.
qr/\N{}/
now disallowed under use re "strict"
An empty \N{}
makes no sense, but for backwards compatibility is
accepted as doing nothing, though a deprecation warning is raised by
default. But now this is a fatal error under the experimental feature
'strict' mode in re.
A my
, our
, or state
declaration is no longer allowed inside
of another my
, our
, or state
declaration.
For example, these are now fatal:
/\C/
character class has been removed.This regular expression character class was deprecated in v5.20.0 and has
produced a deprecation warning since v5.22.0. It is now a compile-time
error. If you need to examine the individual bytes that make up a
UTF8-encoded character, then use utf8::encode()
on the string (or a
copy) first.
chdir('')
no longer chdirs homeUsing chdir('')
or chdir(undef)
to chdir home has been deprecated since
perl v5.8, and will now fail. Use chdir()
instead.
It was legal until now on ASCII platforms for variable names to contain
non-graphical ASCII control characters (ordinals 0 through 31, and 127,
which are the C0 controls and DELETE
). This usage has been
deprecated since v5.20, and as of now causes a syntax error. The
variables these names referred to are special, reserved by Perl for
whatever use it may choose, now, or in the future. Each such variable
has an alternative way of spelling it. Instead of the single
non-graphic control character, a two character sequence beginning with a
caret is used, like $^]
and ${^GLOBAL_PHASE}
. Details are at
perlvar. It remains legal, though unwise and deprecated (raising a
deprecation warning), to use certain non-graphic non-ASCII characters in
variables names when not under use utf8
. No code should do this,
as all such variables are reserved by Perl, and Perl doesn't currently
define any of them (but could at any time, without notice).
$Carp::MaxArgNums
has been fixed$Carp::MaxArgNums
is supposed to be the number of arguments to display.
Prior to this version, it was instead showing $Carp::MaxArgNums
+ 1 arguments,
contrary to the documentation.
[...]
within (?[...])
.The experimental Extended Bracketed Character Classes can contain regular
bracketed character classes within them. These differ from regular ones in
that white space is generally ignored, unless escaped by preceding it with a
backslash. The white space that is ignored is now limited to just tab \t
and SPACE characters. Previously, it was any white space. See
Extended Bracketed Character Classes in perlrecharclass.
IV_MAX
is now deprecatedUnicode defines code points in the range 0..0x10FFFF
. Some standards
at one time defined them up to 2**31 - 1, but Perl has allowed them to
be as high as anything that will fit in a word on the platform being
used. However, use of those above the platform's IV_MAX
is broken in
some constructs, notably tr///
, regular expression patterns involving
quantifiers, and in some arithmetic and comparison operations, such as
being the upper limit of a loop. Now the use of such code points raises
a deprecation warning, unless that warning category is turned off.
IV_MAX
is typically 2**31 -1 on 32-bit platforms, and 2**63-1 on
64-bit ones.
The string bitwise operators treat their operands as strings of bytes,
and values beyond 0xFF are nonsensical in this context. To operate on
encoded bytes, first encode the strings. To operate on code points'
numeric values, use split
and map ord
. In the future, this
warning will be replaced by an exception.
sysread()
, syswrite()
, recv()
and send()
are deprecated on
:utf8 handlesThe sysread()
, recv()
, syswrite()
and send()
operators
are deprecated on handles that have the :utf8
layer, either
explicitly, or implicitly, eg., with the :encoding(UTF-16LE)
layer.
Both sysread()
and recv()
currently use only the :utf8
flag for the
stream, ignoring the actual layers. Since sysread()
and recv()
do no
UTF-8 validation they can end up creating invalidly encoded scalars.
Similarly, syswrite()
and send()
use only the :utf8
flag, otherwise
ignoring any layers. If the flag is set, both write the value UTF-8
encoded, even if the layer is some different encoding, such as the
example above.
Ideally, all of these operators would completely ignore the :utf8
state, working only with bytes, but this would result in silently
breaking existing code. To avoid this a future version of perl will
throw an exception when any of sysread()
, recv()
, syswrite()
or send()
are called on handle with the :utf8
layer.
The overhead of scope entry and exit has been considerably reduced, so for example subroutine calls, loops and basic blocks are all faster now. This empty function call now takes about a third less time to execute:
Many languages, such as Chinese, are caseless. Perl now knows about
most common ones, and skips much of the work when
a program tries to change case in them (like ucfirst()
) or match
caselessly (qr//i
). This will speed up a program, such as a web
server, that can operate on multiple languages, while it is operating on a
caseless one.
/fixed-substr/
has been made much faster.
On platforms with a libc memchr()
implementation which makes good use of
underlying hardware support, patterns which include fixed substrings will now
often be much faster; for example with glibc on a recent x86_64 CPU, this:
- $s = "a" x 1000 . "wxyz";
- $s =~ /wxyz/ for 1..30000
is now about 7 times faster. On systems with slow memchr()
, e.g. 32-bit ARM
Raspberry Pi, there will be a small or little speedup. Conversely, some
pathological cases, such as "ab" x 1000 =~ /aa/
will be slower now; up to 3
times slower on the rPi, 1.5x slower on x86_64.
Faster addition, subtraction and multiplication.
Since 5.8.0, arithmetic became slower due to the need to support 64-bit integers. To deal with 64-bit integers, a lot more corner cases need to be checked, which adds time. We now detect common cases where there is no need to check for those corner cases, and special-case them.
Preincrement, predecrement, postincrement, and postdecrement have been made faster by internally splitting the functions which handled multiple cases into different functions.
Creating Perl debugger data structures (see Debugger Internals in perldebguts)
for XSUBs and const subs has been removed. This removed one glob/scalar combo
for each unique .c
file that XSUBs and const subs came from. On startup
(perl -e"0"
) about half a dozen glob/scalar debugger combos were created.
Loading XS modules created more glob/scalar combos. These things were
being created regardless of whether the perl debugger was being used,
and despite the fact that it can't debug C code anyway
On Win32, stat
ing or -X
ing a path, if the file or directory does not
exist, is now 3.5x faster than before.
Single arguments in list assign are now slightly faster:
- ($x) = (...);
- (...) = ($x);
Less peak memory is now used when compiling regular expression patterns.
arybase has been upgraded from version 0.10 to 0.11.
Attribute::Handlers has been upgraded from version 0.97 to 0.99.
autodie has been upgraded from version 2.26 to 2.29.
autouse has been upgraded from version 1.08 to 1.11.
B has been upgraded from version 1.58 to 1.62.
B::Deparse has been upgraded from version 1.35 to 1.37.
base has been upgraded from version 2.22 to 2.23.
Benchmark has been upgraded from version 1.2 to 1.22.
bignum has been upgraded from version 0.39 to 0.42.
bytes has been upgraded from version 1.04 to 1.05.
Carp has been upgraded from version 1.36 to 1.40.
Compress::Raw::Bzip2 has been upgraded from version 2.068 to 2.069.
Compress::Raw::Zlib has been upgraded from version 2.068 to 2.069.
Config::Perl::V has been upgraded from version 0.24 to 0.25.
CPAN::Meta has been upgraded from version 2.150001 to 2.150005.
CPAN::Meta::Requirements has been upgraded from version 2.132 to 2.140.
CPAN::Meta::YAML has been upgraded from version 0.012 to 0.018.
Data::Dumper has been upgraded from version 2.158 to 2.160.
Devel::Peek has been upgraded from version 1.22 to 1.23.
Devel::PPPort has been upgraded from version 3.31 to 3.32.
Dumpvalue has been upgraded from version 1.17 to 1.18.
DynaLoader has been upgraded from version 1.32 to 1.38.
Encode has been upgraded from version 2.72 to 2.80.
encoding has been upgraded from version 2.14 to 2.17.
encoding::warnings has been upgraded from version 0.11 to 0.12.
English has been upgraded from version 1.09 to 1.10.
Errno has been upgraded from version 1.23 to 1.25.
experimental has been upgraded from version 0.013 to 0.016.
ExtUtils::CBuilder has been upgraded from version 0.280221 to 0.280225.
ExtUtils::Embed has been upgraded from version 1.32 to 1.33.
ExtUtils::MakeMaker has been upgraded from version 7.04_01 to 7.10_01.
ExtUtils::ParseXS has been upgraded from version 3.28 to 3.31.
ExtUtils::Typemaps has been upgraded from version 3.28 to 3.31.
feature has been upgraded from version 1.40 to 1.42.
fields has been upgraded from version 2.17 to 2.23.
File::Find has been upgraded from version 1.29 to 1.34.
File::Glob has been upgraded from version 1.24 to 1.26.
File::Path has been upgraded from version 2.09 to 2.12_01.
File::Spec has been upgraded from version 3.56 to 3.63.
Filter::Util::Call has been upgraded from version 1.54 to 1.55.
Getopt::Long has been upgraded from version 2.45 to 2.48.
Hash::Util has been upgraded from version 0.18 to 0.19.
Hash::Util::FieldHash has been upgraded from version 1.15 to 1.19.
HTTP::Tiny has been upgraded from version 0.054 to 0.056.
I18N::Langinfo has been upgraded from version 0.12 to 0.13.
if has been upgraded from version 0.0604 to 0.0606.
IO has been upgraded from version 1.35 to 1.36.
IO-Compress has been upgraded from version 2.068 to 2.069.
IPC::Open3 has been upgraded from version 1.18 to 1.20.
IPC::SysV has been upgraded from version 2.04 to 2.06_01.
List::Util has been upgraded from version 1.41 to 1.42_02.
locale has been upgraded from version 1.06 to 1.08.
Locale::Codes has been upgraded from version 3.34 to 3.37.
Math::BigInt has been upgraded from version 1.9997 to 1.999715.
Math::BigInt::FastCalc has been upgraded from version 0.31 to 0.40.
Math::BigRat has been upgraded from version 0.2608 to 0.260802.
Module::CoreList has been upgraded from version 5.20150520 to 5.20160320.
Module::Metadata has been upgraded from version 1.000026 to 1.000031.
mro has been upgraded from version 1.17 to 1.18.
ODBM_File has been upgraded from version 1.12 to 1.14.
Opcode has been upgraded from version 1.32 to 1.34.
parent has been upgraded from version 0.232 to 0.234.
Parse::CPAN::Meta has been upgraded from version 1.4414 to 1.4417.
Perl::OSType has been upgraded from version 1.008 to 1.009.
perlfaq has been upgraded from version 5.021009 to 5.021010.
PerlIO::encoding has been upgraded from version 0.21 to 0.24.
PerlIO::mmap has been upgraded from version 0.014 to 0.016.
PerlIO::scalar has been upgraded from version 0.22 to 0.24.
PerlIO::via has been upgraded from version 0.15 to 0.16.
Pod::Functions has been upgraded from version 1.09 to 1.10.
Pod::Perldoc has been upgraded from version 3.25 to 3.25_02.
Pod::Simple has been upgraded from version 3.29 to 3.32.
Pod::Usage has been upgraded from version 1.64 to 1.68.
POSIX has been upgraded from version 1.53 to 1.65.
Scalar::Util has been upgraded from version 1.41 to 1.42_02.
SDBM_File has been upgraded from version 1.13 to 1.14.
SelfLoader has been upgraded from version 1.22 to 1.23.
Socket has been upgraded from version 2.018 to 2.020_03.
Storable has been upgraded from version 2.53 to 2.56.
strict has been upgraded from version 1.09 to 1.11.
Term::ANSIColor has been upgraded from version 4.03 to 4.04.
Term::Cap has been upgraded from version 1.15 to 1.17.
Test has been upgraded from version 1.26 to 1.28.
Test::Harness has been upgraded from version 3.35 to 3.36.
Thread::Queue has been upgraded from version 3.05 to 3.08.
threads has been upgraded from version 2.01 to 2.06.
threads::shared has been upgraded from version 1.48 to 1.50.
Tie::File has been upgraded from version 1.01 to 1.02.
Tie::Scalar has been upgraded from version 1.03 to 1.04.
Time::HiRes has been upgraded from version 1.9726 to 1.9732.
Time::Piece has been upgraded from version 1.29 to 1.31.
Unicode::Collate has been upgraded from version 1.12 to 1.14.
Unicode::Normalize has been upgraded from version 1.18 to 1.25.
Unicode::UCD has been upgraded from version 0.61 to 0.64.
UNIVERSAL has been upgraded from version 1.12 to 1.13.
utf8 has been upgraded from version 1.17 to 1.19.
version has been upgraded from version 0.9909 to 0.9916.
warnings has been upgraded from version 1.32 to 1.36.
Win32 has been upgraded from version 0.51 to 0.52.
Win32API::File has been upgraded from version 0.1202 to 0.1203.
XS::Typemap has been upgraded from version 0.13 to 0.14.
XSLoader has been upgraded from version 0.20 to 0.21.
The process of using undocumented globals has been documented, namely, that one should send email to [email protected] first to get the go-ahead for documenting and using an undocumented function or global variable.
A number of cleanups have been made to perlcall, including:
use EXTEND(SP, n)
and PUSHs()
instead of XPUSHs()
where applicable
and update prose to match
add POPu, POPul and POPpbytex to the "complete list of POP macros" and clarify the documentation for some of the existing entries, and a note about side-effects
add API documentation for POPu and POPul
use ERRSV more efficiently
approaches to thread-safety storage of SVs.
The documentation of hex
has been revised to clarify valid inputs.
Better explain meaning of negative PIDs in waitpid
.
[perl #127080]
General cleanup: there's more consistency now (in POD usage, grammar, code
examples), better practices in code examples (use of my
, removal of bareword
filehandles, dropped usage of &
when calling subroutines, ...), etc.
A new section has been added, Dynamic Scope and the Context Stack in perlguts, which explains how the perl context stack works.
A stronger caution about using locales in threaded applications is given. Locales are not thread-safe, and you can get wrong results or even segfaults if you use them there.
We now recommend contacting the module-authors list or PAUSE in seeking guidance on the naming of modules.
The documentation of qx//
now describes how $?
is affected.
This note has been added to perlpolicy:
Fix some examples to be strict clean.
Clarify that in languages like Japanese and Thai, dictionary lookup is required to determine word boundaries.
Updated to note that anonymous subroutines can have signatures.
Fixed a broken example where =
was used instead of
==
in conditional in do/while example.
The usage of FIRSTKEY
and NEXTKEY
has been clarified.
Discourage use of 'In' as a prefix signifying the Unicode Block property.
The documentation of $@
was reworded to clarify that it is not just for
syntax errors in eval
.
[perl #124034]
The specific true value of $!{E...}
is now documented, noting that it is
subject to change and not guaranteed.
Use of $OLD_PERL_VERSION
is now discouraged.
The documentation of PROTOTYPES
has been corrected; they are disabled
by default, not enabled.
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.
Character following \p must be '{' or a single-character Unicode property name in regex;
Sequence (?... not terminated in regex; marked by <-- HERE in m/%s/
Sequence (?P<... not terminated in regex; marked by <-- HERE in m/%s/
Sequence (?P>... not terminated in regex; marked by <-- HERE in m/%s/
Accessing the IO
part of a glob as FILEHANDLE
instead of IO
is no
longer deprecated. It is discouraged to encourage uniformity (so that, for
example, one can grep more easily) but it will not be removed.
[perl #127060]
The diagnostic Hexadecimal float: internal error
has been changed to
Hexadecimal float: internal error (%s)
to include more information.
Can't modify non-lvalue subroutine call of &%s
This error now reports the name of the non-lvalue subroutine you attempted to use as an lvalue.
When running out of memory during an attempt the increase the stack
size, previously, perl would die using the cryptic message
panic: av_extend_guts() negative count (-9223372036854775681)
.
This has been fixed to show the prettier message:
Out of memory during stack extend
Configure
now acts as if the -O
option is always passed, allowing command
line options to override saved configuration. This should eliminate confusion
when command line options are ignored for no obvious reason. -O
is now
permitted, but ignored.
Bison 3.0 is now supported.
Configure no longer probes for libnm by default. Originally this was the "New Math" library, but the name has been re-used by the GNOME NetworkManager. [perl #127131]
Added Configure probes for newlocale
, freelocale
, and uselocale
.
PPPort.so/PPPort.dll
no longer get installed, as they are
not used by PPPort.pm
, only by its test files.
It is now possible to specify which compilation date to show on
perl -V
output, by setting the macro PERL_BUILD_DATE
.
Using the NO_HASH_SEED
define in combination with the default hash algorithm
PERL_HASH_FUNC_ONE_AT_A_TIME_HARD
resulted in a fatal error while compiling
the interpreter, since Perl 5.17.10. This has been fixed.
Configure should handle spaces in paths a little better.
No longer generate EBCDIC POSIX-BC tables. We don't believe anyone is using Perl and POSIX-BC at this time, and by not generating these tables it saves time during development, and makes the resulting tar ball smaller.
The GNU Make makefile for Win32 now supports parallel builds. [perl #126632]
You can now build perl with MSVC++ on Win32 using GNU Make. [perl #126632]
The Win32 miniperl now has a real getcwd
which increases build performance
resulting in getcwd()
being 605x faster in Win32 miniperl.
Configure now takes -Dusequadmath
into account when calculating the
alignbytes
configuration variable. Previously the mis-calculated
alignbytes
could cause alignment errors on debugging builds. [perl
#127894]
A new test (t/op/aassign.t) has been added to test the list assignment operator
OP_AASSIGN
.
Parallel building has been added to the dmake makefile.mk
makefile. All
Win32 compilers are supported.
The AmigaOS port has been reintegrated into the main tree, based off of Perl 5.22.1.
Tests are more robust against unusual cygdrive prefixes. [perl #126834]
UTF-EBCDIC is like UTF-8, but for EBCDIC platforms. It now has been extended so that it can represent code points up to 2 ** 64 - 1 on platforms with 64-bit words. This brings it into parity with UTF-8. This enhancement requires an incompatible change to the representation of code points in the range 2 ** 30 to 2 ** 31 -1 (the latter was the previous maximum representable code point). This means that a file that contains one of these code points, written out with previous versions of perl cannot be read in, without conversion, by a perl containing this change. We do not believe any such files are in existence, but if you do have one, submit a ticket at [email protected], and we will write a conversion script for you.
cmp()
and sort()
fixed for UTF-EBCDIC strings
Comparing two strings that were both encoded in UTF-8 (or more
precisely, UTF-EBCDIC) did not work properly until now. Since sort()
uses cmp()
, this fixes that as well.
tr///
and y///
fixed for \N{}
, and use utf8
ranges
Perl v5.22 introduced the concept of portable ranges to regular
expression patterns. A portable range matches the same set of
characters no matter what platform is being run on. This concept is now
extended to tr///
. See
tr///
.
There were also some problems with these operations under use
utf8
, which are now fixed
Use the fdclose()
function from FreeBSD if it is available.
[perl #126847]
Under some circumstances IRIX stdio fgetc()
and fread()
set the errno to
ENOENT
, which made no sense according to either IRIX or POSIX docs. Errno
is now cleared in such cases.
[perl #123977]
Problems when multiplying long doubles by infinity have been fixed. [perl #126396]
Until now OS X builds of perl have specified a link target of 10.3 (Panther,
2003) but have not specified a compiler target. From now on, builds of perl on
OS X 10.6 or later (Snow Leopard, 2008) by default capture the current OS X
version and specify that as the explicit build target in both compiler and
linker flags, thus preserving binary compatibility for extensions built later
regardless of changes in OS X, SDK, or compiler and linker versions. To
override the default value used in the build and preserved in the flags,
specify export MACOSX_DEPLOYMENT_TARGET=10.N
before configuring and building
perl, where 10.N is the version of OS X you wish to target. In OS X 10.5 or
earlier there is no change to the behavior present when those systems were
current; the link target is still OS X 10.3 and there is no explicit compiler
target.
Builds with both -DDEBUGGING and threading enabled would fail with a
"panic: free from wrong pool" error when built or tested from Terminal
on OS X. This was caused by perl's internal management of the
environment conflicting with an atfork handler using the libc
setenv()
function to update the environment.
Perl now uses setenv()
/unsetenv()
to update the environment on OS X.
[perl #126240]
All Solaris variants now build a shared libperl
Solaris and variants like OpenIndiana now always build with the shared Perl library (Configure -Duseshrplib). This was required for the OpenIndiana builds, but this has also been the setting for Oracle/Sun Perl builds for several years.
Workaround where Tru64 balks when prototypes are listed as
PERL_STATIC_INLINE
, but where the test is build with
-DPERL_NO_INLINE_FUNCTIONS
.
On VMS, the math function prototypes in math.h
are now visible under C++.
Now building the POSIX extension with C++ will no longer crash.
VMS has had setenv
/unsetenv
since v7.0 (released in 1996),
Perl_vmssetenv
now always uses setenv
/unsetenv
.
Perl now implements its own killpg
by scanning for processes in the
specified process group, which may not mean exactly the same thing as a Unix
process group, but allows us to send a signal to a parent (or master) process
and all of its sub-processes. At the perl level, this means we can now send a
negative pid like so:
- kill SIGKILL, -$pid;
to signal all processes in the same group as $pid
.
For those %ENV
elements based on the CRTL environ array, we've always
preserved case when setting them but did look-ups only after upcasing the
key first, which made lower- or mixed-case entries go missing. This problem
has been corrected by making %ENV
elements derived from the environ array
case-sensitive on look-up as well as case-preserving on store.
Environment look-ups for PERL5LIB
and PERLLIB
previously only
considered logical names, but now consider all sources of %ENV
as
determined by PERL_ENV_TABLES
and as documented in %ENV in perlvms.
The minimum supported version of VMS is now v7.3-2, released in 2003. As a side effect of this change, VAX is no longer supported as the terminal release of OpenVMS VAX was v7.3 in 2001.
A new build option USE_NO_REGISTRY
has been added to the makefiles. This
option is off by default, meaning the default is to do Windows registry
lookups. This option stops Perl from looking inside the registry for anything.
For what values are looked up in the registry see perlwin32. Internally, in
C, the name of this option is WIN32_NO_REGISTRY
.
The behavior of Perl using HKEY_CURRENT_USER\Software\Perl
and
HKEY_LOCAL_MACHINE\Software\Perl
to lookup certain values, including %ENV
vars starting with PERL
has changed. Previously, the 2 keys were checked
for entries at all times through the perl process's life time even if
they did not
exist. For performance reasons, now, if the root key (i.e.
HKEY_CURRENT_USER\Software\Perl
or HKEY_LOCAL_MACHINE\Software\Perl
) does
not exist at process start time, it will not be checked again for %ENV
override entries for the remainder of the perl process's life. This more
closely matches Unix behavior in that the environment is copied or inherited
on startup and changing the variable in the parent process or another process
or editing .bashrc will not change the environmental variable in other
existing, running, processes.
One glob fetch was removed for each -X
or stat
call whether done from
Perl code or internally from Perl's C code. The glob being looked up was
${^WIN32_SLOPPY_STAT}
which is a special variable. This makes -X
and
stat
slightly faster.
During miniperl's process startup, during the build process, 4 to 8 IO calls related to the process starting .pl and the buildcustomize.pl file were removed from the code opening and executing the first 1 or 2 .pl files.
Builds using Microsoft Visual C++ 2003 and earlier no longer produce an "INTERNAL COMPILER ERROR" message. [perl #126045]
Visual C++ 2013 builds will now execute on XP and higher. Previously they would only execute on Vista and higher.
You can now build perl with GNU Make and GCC. [perl #123440]
truncate($filename, $size)
now works for files over 4GB in size.
[perl #125347]
Parallel building has been added to the dmake makefile.mk
makefile. All
Win32 compilers are supported.
Building a 64-bit perl with a 64-bit GCC but a 32-bit gmake would
result in an invalid $Config{archname}
for the resulting perl.
[perl #127584]
Errors set by Winsock functions are now put directly into $^E
, and the
relevant WSAE*
error codes are now exported from the Errno and POSIX
modules for testing this against.
The previous behavior of putting the errors (converted to POSIX-style E*
error codes since Perl 5.20.0) into $!
was buggy due to the non-equivalence
of like-named Winsock and POSIX error constants, a relationship between which
has unfortunately been established in one way or another since Perl 5.8.0.
The new behavior provides a much more robust solution for checking Winsock errors in portable software without accidentally matching POSIX tests that were intended for other OSes and may have different meanings for Winsock.
The old behavior is currently retained, warts and all, for backwards
compatibility, but users are encouraged to change any code that tests $!
against E*
constants for Winsock errors to instead test $^E
against
WSAE*
constants. After a suitable deprecation period, the old behavior may
be removed, leaving $!
unchanged after Winsock function calls, to avoid any
possible confusion over which error variable to check.
The implementation of perl's context stack system, and its internal API, have been heavily reworked. Note that no significant changes have been made to any external APIs, but XS code which relies on such internal details may need to be fixed. The main changes are:
The PUSHBLOCK()
, POPSUB()
etc. macros have been replaced with static
inline functions such as cx_pushblock()
, cx_popsub()
etc. These use
function args rather than implicitly relying on local vars such as
gimme
and newsp
being available. Also their functionality has
changed: in particular, cx_popblock()
no longer decrements
cxstack_ix
. The ordering of the steps in the pp_leave*
functions
involving cx_popblock()
, cx_popsub()
etc. has changed. See the new
documentation, Dynamic Scope and the Context Stack in perlguts, for
details on how to use them.
Various macros, which now consistently have a CX_ prefix, have been added:
- CX_CUR(), CX_LEAVE_SCOPE(), CX_POP()
or renamed:
- CX_POP_SAVEARRAY(), CX_DEBUG(), CX_PUSHSUBST(), CX_POPSUBST()
cx_pushblock()
now saves PL_savestack_ix
and PL_tmps_floor
, so
pp_enter*
and pp_leave*
no longer do
- ENTER; SAVETMPS; ....; LEAVE
cx_popblock()
now also restores PL_curpm
.
In dounwind()
for every context type, the current savestack frame is
now processed before each context is popped; formerly this was only done
for sub-like context frames. This action has been removed from
cx_popsub()
and placed into its own macro, CX_LEAVE_SCOPE(cx)
, which
must be called before cx_popsub()
etc.
dounwind()
now also does a cx_popblock()
on the last popped frame
(formerly it only did the cx_popsub()
etc. actions on each frame).
The temps stack is now freed on scope exit; previously, temps created
during the last statement of a block wouldn't be freed until the next
nextstate
following the block (apart from an existing hack that did
this for recursive subs in scalar context); and in something like
f(g())
, the temps created by the last statement in g()
would
formerly not be freed until the statement following the return from
f()
.
Most values that were saved on the savestack on scope entry are now
saved in suitable new fields in the context struct, and saved and
restored directly by cx_pushfoo()
and cx_popfoo()
, which is much
faster.
Various context struct fields have been added, removed or modified.
The handling of @_
in cx_pushsub()
and cx_popsub()
has been
considerably tidied up, including removing the argarray
field from the
context struct, and extracting out some common (but rarely used) code into
a separate function, clear_defarray()
. Also, useful subsets of
cx_popsub()
which had been unrolled in places like pp_goto
have been
gathered into the new functions cx_popsub_args()
and
cx_popsub_common()
.
pp_leavesub
and pp_leavesublv
now use the same function as the rest
of the pp_leave*
's to process return args.
CXp_FOR_PAD
and CXp_FOR_GV
flags have been added, and
CXt_LOOP_FOR
has been split into CXt_LOOP_LIST
, CXt_LOOP_ARY
.
Some variables formerly declared by dMULTICALL
(but not documented) have
been removed.
The obscure PL_timesbuf
variable, effectively a vestige of Perl 1, has
been removed. It was documented as deprecated in Perl 5.20, with a statement
that it would be removed early in the 5.21.x series; that has now finally
happened.
[perl #121351]
An unwarranted assertion in Perl_newATTRSUB_x()
has been removed. If
a stub subroutine
definition with a prototype has been seen, then any subsequent stub (or
definition) of the same subroutine with an attribute was causing an assertion
failure because of a null pointer.
[perl #126845]
::
has been replaced by __
in ExtUtils::ParseXS
, like it's done for
parameters/return values. This is more consistent, and simplifies writing XS
code wrapping C++ classes into a nested Perl namespace (it requires only
a typedef for Foo__Bar
rather than two, one for Foo_Bar
and the other
for Foo::Bar
).
The to_utf8_case()
function is now deprecated. Instead use
toUPPER_utf8
, toTITLE_utf8
, toLOWER_utf8
, and toFOLD_utf8
.
(See http://nntp.perl.org/group/perl.perl5.porters/233287.)
Perl core code and the threads extension have been annotated so that, if Perl is configured to use threads, then during compile-time clang (3.6 or later) will warn about suspicious uses of mutexes. See http://clang.llvm.org/docs/ThreadSafetyAnalysis.html for more information.
The signbit()
emulation has been enhanced. This will help older
and/or more exotic platforms or configurations.
Most EBCDIC-specific code in the core has been unified with non-EBCDIC code, to avoid repetition and make maintenance easier.
MSWin32 code for $^X
has been moved out of the win32 directory to
caretx.c, where other operating systems set that variable.
sv_ref()
is now part of the API.
sv_backoff in perlapi had its return type changed from int
to void
. It
previously has always returned 0
since Perl 5.000 stable but that was
undocumented. Although sv_backoff
is marked as public API, XS code is not
expected to be impacted since the proper API call would be through public API
sv_setsv(sv, &PL_sv_undef)
, or quasi-public SvOOK_off
, or non-public
SvOK_off
calls, and the return value of sv_backoff
was previously a
meaningless constant that can be rewritten as (sv_backoff(sv),0)
.
The EXTEND
and MEXTEND
macros have been improved to avoid various issues
with integer truncation and wrapping. In particular, some casts formerly used
within the macros have been removed. This means for example that passing an
unsigned nitems
argument is likely to raise a compiler warning now
(it's always been documented to require a signed value; formerly int,
lately SSize_t).
PL_sawalias
and GPf_ALIASED_SV
have been removed.
GvASSIGN_GENERATION
and GvASSIGN_GENERATION_set
have been removed.
It now works properly to specify a user-defined property, such as
- qr/\p{mypkg1::IsMyProperty}/i
with /i
caseless matching, an explicit package name, and
IsMyProperty not defined at the time of the pattern compilation.
Perl's memcpy()
, memmove()
, memset()
and memcmp()
fallbacks are now
more compatible with the originals. [perl #127619]
Fixed the issue where a s///r
) with -DPERL_NO_COW attempts
to modify the source SV, resulting in the program dying. [perl #127635]
Fixed an EBCDIC-platform-only case where a pattern could fail to match. This occurred when matching characters from the set of C1 controls when the target matched string was in UTF-8.
Narrow the filename check in strict.pm and warnings.pm. Previously,
it assumed that if the filename (without the .pmc? extension) differed
from the package name, if was a misspelled use statement (i.e. use Strict
instead of use strict
). We now check whether there's really a
miscapitalization happening, and not some other issue.
Turn an assertion into a more user friendly failure when parsing regexes. [perl #127599]
Correctly raise an error when trying to compile patterns with unterminated character classes while there are trailing backslashes. [perl #126141].
Line numbers larger than 2**31-1 but less than 2**32 are no longer
returned by caller()
as negative numbers. [perl #126991]
unless ( assignment )
now properly warns when syntax
warnings are enabled. [perl #127122]
Setting an ISA
glob to an array reference now properly adds
isaelem
magic to any existing elements. Previously modifying such
an element would not update the ISA cache, so method calls would call
the wrong function. Perl would also crash if the ISA
glob was
destroyed, since new code added in 5.23.7 would try to release the
isaelem
magic from the elements. [perl #127351]
If a here-doc was found while parsing another operator, the parser had already read end of file, and the here-doc was not terminated, perl could produce an assertion or a segmentation fault. This now reliably complains about the unterminated here-doc. [perl #125540]
untie()
would sometimes return the last value returned by the UNTIE()
handler as well as it's normal value, messing up the stack. [perl
#126621]
Fixed an operator precedence problem when castflags & 2
is true.
[perl #127474]
Caching of DESTROY methods could result in a non-pointer or a
non-STASH stored in the SvSTASH()
slot of a stash, breaking the B
STASH()
method. The DESTROY method is now cached in the MRO metadata
for the stash. [perl #126410]
The AUTOLOAD method is now called when searching for a DESTROY method,
and correctly sets $AUTOLOAD
too. [perl #124387] [perl #127494]
Avoid parsing beyond the end of the buffer when processing a #line
directive with no filename. [perl #127334]
Perl now raises a warning when a regular expression pattern looks like
it was supposed to contain a POSIX class, like qr/[[:alpha:]]/
, but
there was some slight defect in its specification which causes it to
instead be treated as a regular bracketed character class. An example
would be missing the second colon in the above like this:
qr/[[:alpha]]/
. This compiles to match a sequence of two characters.
The second is "]"
, and the first is any of: "["
, ":"
, "a"
,
"h"
, "l"
, or "p"
. This is unlikely to be the intended
meaning, and now a warning is raised. No warning is raised unless the
specification is very close to one of the 14 legal POSIX classes. (See
POSIX Character Classes in perlrecharclass.)
[perl #8904]
Certain regex patterns involving a complemented POSIX class in an
inverted bracketed character class, and matching something else
optionally would improperly fail to match. An example of one that could
fail is qr/_?[^\Wbar]\x{100}/
. This has been fixed.
[perl #127537]
Perl 5.22 added support to the C99 hexadecimal floating point notation, but sometimes misparses hex floats. This has been fixed. [perl #127183]
A regression that allowed undeclared barewords in hash keys to work despite strictures has been fixed. [perl #126981]
Calls to the placeholder &PL_sv_yes
used internally when an import()
or unimport()
method isn't found now correctly handle scalar context.
[perl #126042]
Report more context when we see an array where we expect to see an operator and avoid an assertion failure. [perl #123737]
Modifying an array that was previously a package @ISA
no longer
causes assertion failures or crashes.
[perl #123788]
Retain binary compatibility across plain and DEBUGGING perl builds. [perl #127212]
Avoid leaking memory when setting $ENV{foo}
on darwin.
[perl #126240]
/...\G/
no longer crashes on utf8 strings. When \G
is a fixed number
of characters from the start of the regex, perl needs to count back that
many characters from the current pos()
position and start matching from
there. However, it was counting back bytes rather than characters, which
could lead to panics on utf8 strings.
In some cases operators that return integers would return negative integers as large positive integers. [perl #126635]
The pipe()
operator would assert for DEBUGGING builds instead of
producing the correct error message. The condition asserted on is
detected and reported on correctly without the assertions, so the
assertions were removed.
[perl #126480]
In some cases, failing to parse a here-doc would attempt to use freed memory. This was caused by a pointer not being restored correctly. [perl #126443]
@x = sort { *a = 0; $a <=> $b } 0 .. 1
no longer frees the GP
for *a before restoring its SV slot.
[perl #124097]
Multiple problems with the new hexadecimal floating point printf
format %a
were fixed:
[perl #126582],
[perl #126586],
[perl #126822]
Calling mg_set()
in leave_scope()
no longer leaks.
A regression from Perl v5.20 was fixed in which debugging output of regular expression compilation was wrong. (The pattern was correctly compiled, but what got displayed for it was wrong.)
\b{sb}
works much better. In Perl v5.22.0, this new construct didn't
seem to give the expected results, yet passed all the tests in the
extensive suite furnished by Unicode. It turns out that it was because
these were short input strings, and the failures had to do with longer
inputs.
Certain syntax errors in Extended Bracketed Character Classes in perlrecharclass caused panics instead of the proper error message. This has now been fixed. [perl #126481]
Perl 5.20 added a message when a quantifier in a regular expression was useless, but then caused the parser to skip it; this caused the surplus quantifier to be silently ignored, instead of throwing an error. This is now fixed. [perl #126253]
The switch to building non-XS modules last in win32/makefile.mk (introduced by design as part of the changes to enable parallel building) caused the build of POSIX to break due to problems with the version module. This is now fixed.
Improved parsing of hex float constants.
Fixed an issue with pack
where pack "H"
(and pack "h"
)
could read past the source when given a non-utf8 source, and a utf8 target.
[perl #126325]
Fixed several cases where perl would abort due to a segmentation fault, or a C-level assert. [perl #126615], [perl #126602], [perl #126193].
There were places in regular expression patterns where comments ((?#...)
)
weren't allowed, but should have been. This is now fixed.
[perl #116639]
Some regressions from Perl 5.20 have been fixed, in which some syntax errors in (?[...]) constructs within regular expression patterns could cause a segfault instead of a proper error message. [perl #126180] [perl #126404]
Another problem with
(?[...])
constructs has been fixed wherein things like \c]
could cause panics.
[perl #126181]
Some problems with attempting to extend the perl stack to around 2G or 4G entries have been fixed. This was particularly an issue on 32-bit perls built to use 64-bit integers, and was easily noticeable with the list repetition operator, e.g.
- @a = (1) x $big_number
Formerly perl may have crashed, depending on the exact value of $big_number
;
now it will typically raise an exception.
[perl #125937]
In a regex conditional expression (?(condition)yes-pattern|no-pattern)
, if
the condition is (?!)
then perl failed the match outright instead of
matching the no-pattern. This has been fixed.
[perl #126222]
The special backtracking control verbs (*VERB:ARG)
now all allow an optional
argument and set REGERROR
/REGMARK
appropriately as well.
[perl #126186]
Several bugs, including a segmentation fault, have been fixed with the boundary
checking constructs (introduced in Perl 5.22) \b{gcb}
, \b{sb}
, \b{wb}
,
\B{gcb}
, \B{sb}
, and \B{wb}
. All the \B{}
ones now match an empty
string; none of the \b{}
ones do.
[perl #126319]
Duplicating a closed file handle for write no longer creates a filename of the form GLOB(0xXXXXXXXX). [perl #125115]
Warning fatality is now ignored when rewinding the stack. This prevents infinite recursion when the now fatal error also causes rewinding of the stack. [perl #123398]
In perl v5.22.0, the logic changed when parsing a numeric parameter to the -C option, such that the successfully parsed number was not saved as the option value if it parsed to the end of the argument. [perl #125381]
The PadlistNAMES macro is an lvalue again.
Zero -DPERL_TRACE_OPS memory for sub-threads.
perl_clone_using()
was missing Zero init of PL_op_exec_cnt[]. This
caused sub-threads in threaded -DPERL_TRACE_OPS builds to spew exceedingly
large op-counts at destruct. These counts would print %x as "ABABABAB",
clearly a mem-poison value.
A leak in the XS typemap caused one scalar to be leaked each time a FILE *
or a PerlIO *
was OUTPUT:
ed or imported to Perl, since perl 5.000. These
particular typemap entries are thought to be extremely rarely used by XS
modules. [perl #124181]
alarm()
and sleep()
will now warn if the argument is a negative number
and return undef. Previously they would pass the negative value to the
underlying C function which may have set up a timer with a surprising value.
Perl can again be compiled with any Unicode version. This used to
(mostly) work, but was lost in v5.18 through v5.20. The property
Name_Alias
did not exist prior to Unicode 5.0. Unicode::UCD
incorrectly said it did. This has been fixed.
Very large code-points (beyond Unicode) in regular expressions no longer cause a buffer overflow in some cases when converted to UTF-8. [perl #125826]
The integer overflow check for the range operator (...) in list context now correctly handles the case where the size of the range is larger than the address space. This could happen on 32-bits with -Duse64bitint. [perl #125781]
A crash with %::=(); J->${\"::"}
has been fixed.
[perl #125541]
qr/(?[ () ])/
no longer segfaults, giving a syntax error message instead.
[perl #125805]
Regular expression possessive quantifier v5.20 regression now fixed.
qr/
PAT{
min,max}+
/
is supposed to behave identically
to qr/(?>
PAT{
min,max})/
. Since v5.20, this didn't
work if min and max were equal. [perl #125825]
BEGIN <>
no longer segfaults and properly produces an error
message. [perl #125341]
In tr///
an illegal backwards range like tr/\x{101}-\x{100}//
was
not always detected, giving incorrect results. This is now fixed.
Perl 5.24.0 represents approximately 11 months of development since Perl 5.24.0 and contains approximately 360,000 lines of changes across 1,800 files from 75 authors.
Excluding auto-generated files, documentation and release tools, there were approximately 250,000 lines of changes to 1,200 .pm, .t, .c and .h files.
Perl continues to flourish into its third decade thanks to a vibrant community of users and developers. The following people are known to have contributed the improvements that became Perl 5.24.0:
Aaron Crane, Aaron Priven, Abigail, Achim Gratz, Alexander D'Archangel, Alex Vandiver, Andreas König, Andy Broad, Andy Dougherty, Aristotle Pagaltzis, Chase Whitener, Chas. Owens, Chris 'BinGOs' Williams, Craig A. Berry, Dagfinn Ilmari Mannsåker, Dan Collins, Daniel Dragan, David Golden, David Mitchell, Doug Bell, Dr.Ruud, Ed Avis, Ed J, Father Chrysostomos, Herbert Breunung, H.Merijn Brand, Hugo van der Sanden, Ivan Pozdeev, James E Keenan, Jan Dubois, Jarkko Hietaniemi, Jerry D. Hedden, Jim Cromie, John Peacock, John SJ Anderson, Karen Etheridge, Karl Williamson, kmx, Leon Timmermans, Ludovic E. R. Tolhurst-Cleaver, Lukas Mai, Martijn Lievaart, Matthew Horsfall, Mattia Barbon, Max Maischein, Mohammed El-Afifi, Nicholas Clark, Nicolas R., Niko Tyni, Peter John Acklam, Peter Martini, Peter Rabbitson, Pip Cet, Rafael Garcia-Suarez, Reini Urban, Ricardo Signes, Sawyer X, Shlomi Fish, Sisyphus, Stanislaw Pusep, Steffen Müller, Stevan Little, Steve Hay, Sullivan Beck, Thomas Sibley, Todd Rinaldo, Tom Hukins, Tony Cook, Unicode Consortium, Victor Adam, Vincent Pit, Vladimir Timofeev, Yves Orton, Zachary Storer, Zefram.
The list above is almost certainly incomplete as it is automatically generated from version control history. In particular, it does not include the names of the (very much appreciated) contributors who reported issues to the Perl bug tracker.
Many of the changes included in this version originated in the CPAN modules included in Perl's core. We're grateful to the entire CPAN community for helping Perl to flourish.
For a more complete list of all of Perl's historical contributors, please see the AUTHORS file in the Perl source distribution.
If you find what you think is a bug, you might check the articles recently posted to the comp.lang.perl.misc newsgroup and the perl bug database at https://rt.perl.org/ . There may also be information at http://www.perl.org/ , the Perl Home Page.
If you believe you have an unreported bug, please run the perlbug program
included with your release. Be sure to trim your bug down to a tiny but
sufficient test case. Your bug report, along with the output of perl -V
,
will be sent off to [email protected] to be analysed by the Perl porting team.
If the bug you are reporting has security implications which make it inappropriate to send to a publicly archived mailing list, then see SECURITY VULNERABILITY CONTACT INFORMATION in perlsec for details of how to report the issue.
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.