X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/caec1979d2248e31dd6f584f10772d0aa0d7cf92..edf72ff9d4c8887a03cce52d996b565862ed1630:/pod/perldelta.pod diff --git a/pod/perldelta.pod b/pod/perldelta.pod index 1394824..74a1082 100644 --- a/pod/perldelta.pod +++ b/pod/perldelta.pod @@ -1,72 +1,746 @@ +=encoding utf8 + =head1 NAME -perldelta - what is new for perl v5.9.0 +[ this is a template for a new perldelta file. Any text flagged as +XXX needs to be processed before release. ] + +perldelta - what is new for perl v5.13.6 =head1 DESCRIPTION -This document describes differences between the 5.8.0 release and -the 5.9.0 release. +This document describes differences between the 5.13.5 release and +the 5.13.6 release. -=head1 Incompatible Changes +If you are upgrading from an earlier release such as 5.13.4, first read +L, which describes differences between 5.13.4 and +5.13.5. + +=head1 Notice + +XXX Any important notices here =head1 Core Enhancements -=head2 Tied Arrays with Negative Array Indices +XXX New core language features go here. Summarise user-visible core language +enhancements. Particularly prominent performance optimisations could go +here, but most should go in the L section. + +[ List each enhancement as a =head2 entry ] + +=head2 C<(?^...)> regex construct added to signify default modifiers + +A caret (also called a "cirumflex accent") C<"^"> immediately following +a C<"(?"> in a regular expression now means that the subexpression is to +not inherit the surrounding modifiers such as C, but to revert to the +Perl defaults. Any modifiers following the caret override the defaults. + +The stringification of regular expressions now uses this notation. The +main purpose of this is to allow tests that rely on the stringification +to not have to change when new modifiers are added. See +L. + +=head2 C<"d">, C<"l">, and C<"u"> regex modifiers added + +These modifiers are currently only available within a C<(?...)> construct. + +The C<"l"> modifier says to compile the regular expression as if it were +in the scope of C, even if it is not. + +The C<"u"> modifier currently does nothing. + +The C<"d"> modifier is used in the scope of C to compile the +regular expression as if it were not in that scope. +See L. + +=head2 C<\N{...}> now handles Unicode named character sequences + +Unicode has a number of named character sequences, in which particular sequences +of code points are given names. C<\N{...}> now recognizes these. +See L. + +=head2 New function C + +This function is a run-time version of C<\N{...}>, returning the string +of characters whose Unicode name is its parameter. It can handle +Unicode named character sequences, whereas the pre-existing +C cannot, as the latter returns a single code +point. +See L. + +=head1 Security + +XXX Any security-related notices go here. In particular, any security +vulnerabilities closed should be noted here rather than in the +L section. + +[ List each security issue as a =head2 entry ] + +=head1 Incompatible Changes + +=head2 Stringification of regexes has changed + +Default regular expression modifiers are now notated by using +C<(?^...)>. Code relying on the old stringification will fail. The +purpose of this is so that when new modifiers are added, such code will +not have to change (after this one time), as the stringification will +automatically incorporate the new modifiers. + +Code that needs to work properly with both old- and new-style regexes +can avoid the whole issue by using (for Perls since 5.9.5): + + use re qw(regexp_pattern); + my ($pat, $mods) = regexp_pattern($re_ref); + +where C<$re_ref> is a reference to a compiled regular expression. Upon +return, C<$mods> will be a string containing all the non-default +modifiers used when the regular expression was compiled, and C<$pattern> +the actual pattern. + +If the actual stringification is important, or older Perls need to be +supported, you can use something like the following: + + # Accept both old and new-style stringification + my $modifiers = (qr/foobar/ =~ /\Q(?^/) ? '^' : '-xism'; + +And then use C<$modifiers> instead of C<-xism>. + +=head2 Regular expressions retain their localeness when interpolated + +Regular expressions compiled under C<"use locale"> now retain this when +interpolated into a new regular expression compiled outside a +C<"use locale">, and vice-versa. -Formerly, the indices passed to C, C, C, and -C methods in tied array class were always non-negative. If -the actual argument was negative, Perl would call FETCHSIZE implicitly -and add the result to the index before passing the result to the tied -array method. This behavior is now optional. If the tied array class -contains a package variable named C<$NEGATIVE_INDICES> which is set to -a true value, negative values will be passed to C, C, -C, and C unchanged. +Previously, a regular expression interpolated into another one inherited +the localeness of the surrounding one, losing whatever state it +originally had. This is considered a bug fix, but may trip up code that +has come to rely on the incorrect behavior. -=head2 Fewer parentheses needed with C +[ List each incompatible change as a =head2 entry ] -The grammar of the conditional operator (C<$x ? $y : $z>) has been -broadened so that any operator may appear between the C and the -C<:> without parentheses. Previously, the comma operator and the -low-precedence logical operators had required parentheses in this -context. For instance, you may now write +=head2 Directory handles not copied to threads - $x ? $a and $b : $c +On systems that do not have a C function, newly-created threads no +longer inherit directory handles from their parent threads. Such programs +would probably have crashed anyway +L<[perl #75154]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=75154>. -as a shorter version of the more explicit +=head2 Negation treats strings differently from before - $x ? ($a and $b) : $c +The unary negation operator C<-> now treats strings that look like numbers +as numbers +L<[perl #57706]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=57706>. -Perl is now compatible with C in this regard. However, writing the -parentheses is still recommended as a matter of style. +=head2 Negative zero + +Negative zero (-0.0), when converted to a string, now becomes "0" on all +platforms. It used to become "-0" on some, but "0" on others. + +If you still need to determine whether a zero is negative, use +C or the L module on CPAN. + +=head1 Deprecations + +XXX Any deprecated features, syntax, modules etc. should be listed here. +In particular, deprecated modules should be listed here even if they are +listed as an updated module in the L section. + +[ List each deprecation as a =head2 entry ] + +=head1 Performance Enhancements + +XXX Changes which enhance performance without changing behaviour go here. There +may well be none in a stable release. + +[ List each enhancement as a =item entry ] + +=over 4 + +=item * + +XXX + +=back =head1 Modules and Pragmata +XXX All changes to installed files in F, F, F and F +go here. If Module::CoreList is updated, generate an initial draft of the +following sections using F, which prints stub +entries to STDOUT. Results can be pasted in place of the '=head2' entries +below. A paragraph summary for important changes should then be added by hand. +In an ideal world, dual-life modules would have a F file that could be +cribbed. + +[ Within each section, list entries as a =item entry ] + +=head2 New Modules and Pragmata + +=over 4 + +=item * + +XXX + +=back + +=head2 Updated Modules and Pragmata + +=over 4 + +=item * + +C has been upgraded from version 0.42 to 0.44 + +=item * + +C has been upgraded from version 1.18 to 1.19. + +It no longer autovivifies the C<*CORE::GLOBAL::caller> glob, something it +started doing in 1.18, which was released with perl 5.13.4 +L<[perl #78082]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=78082> + +=item * + +C has been upgraded from version 2.128 to 2.129. + +C no longer crashes with globs returned by C<*$io_ref> +L<[perl #72332]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=72332>. + +=item * + +C has been upgraded from version 2.40 to 2.51. + +It is now safe to use this module in combination with threads. + +=item * + +C has been upgraded from version 1.02 to 1.03. + +It allows patterns containing literal parentheses (they no longer need to +be escaped). On Windows, it no longer adds an extra F<./> to the file names +returned when the pattern is a relative glob with a drive specification, +like F +L<[perl #71712]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=71712>. + +=item * + +C has been upgraded from version 1.17 to 1.18. + +It improves handling of backslashes on Windows, so that paths such as +F are no longer generated +L<[perl #71710]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=71710>. + +=item * + +C has been upgraded from version 0.05 to 0.06 + +=item * + +C has been upgraded from version 1.06 to 1.07. + +The internal C routine now knows how to handle file descriptors, as +documented, so duplicating STDIN in a child process using its file +descriptor now works +L<[perl #76474]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=71710>. + +=item * + +C has been upgraded from version 1.15 to 1.16. + +It fixes an infinite loop in C when +working with tainted values +(L). + +C<< ->maketext >> calls will now backup and restore C<$@> so that error +messages are not supressed +(L). + +=item * + +C has been upgraded from version 1.95 to 1.96. + +=item * + +C has been upgraded from version 0.64 to 0.65. + +=item * + +C has been upgraded from version 1.10 to 1.11. + +C can now handle subroutines that are themselves blessed +into overloaded classes +L<[perl #71998]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=71998>. + +=item * + +C has been upgraded from version 3.31_01 to 3.34. + +=item * + +C has been upgraded from version 1.04 to 1.05. + +It no longer tries to modify read-only arguments when generating a +backtrace +L<[perl #72340]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=72340>. + +=item * + +C has been upgrade from version 1.77_03 to 1.81 + +=item * + +C has been upgraded from version 0.59 to 0.61 + +U::C::Locale newly supports locales: de__phonebook, nso, om, tn, vi, hr, ig, sq + +=item * + +C has been upgraded from version 1.06 to 1.07 + +=back + +=head2 Removed Modules and Pragmata + +=over 4 + +=item * + +XXX + +=back + +=head1 Documentation + +XXX Changes to files in F go here. Consider grouping entries by +file and be sure to link to the appropriate page, e.g. L. + +=head2 New Documentation + +XXX Changes which create B files in F go here. + +=head3 L + +XXX Description of the purpose of the new file here + +=head2 Changes to Existing Documentation + +XXX Changes which significantly change existing files in F go here. +However, any changes to F should go in the L +section. + +=head3 L + +=over 4 + +=item * + +The documentation for the C macro was simply wrong in stating that +get-magic is not processed. It has been corrected. + +=back + +=head1 Diagnostics + +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 L. + +XXX New or changed warnings emitted by the core's C code go here. Also +include any changes in L that reconcile it to the C code. + +[ Within each section, list entries as a =item entry ] + +=head2 New Diagnostics + +XXX Newly added diagnostic messages go here + +=over 4 + +=item * + +XXX + +=back + +=head2 Changes to Existing Diagnostics + +XXX Changes (i.e. rewording) of diagnostic messages go here + +=over 4 + +=item * + +The 'Layer does not match this perl' error message has been replaced with +these more helpful messages: + +=over 4 + +=item * + +PerlIO layer function table size (%d) does not match size expected by this +perl (%d) + +=item * + +PerlIO layer instance size (%d) does not match size expected by this perl +(%d) + +=back + +L<[perl #73754]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=73754> + +=back + =head1 Utility Changes -=head1 New Documentation +XXX Changes to installed programs such as F and F go +here. Most of these are built within the directories F and F. -=head1 Performance Enhancements +[ List utility changes as a =head3 entry for each utility and =item +entries for each change +Use L with program names to get proper documentation linking. ] + +=head3 L + +=over 4 + +=item * + +XXX + +=back + +=head1 Configuration and Compilation + +XXX Changes to F, F, F, and analogous tools +go here. Any other changes to the Perl build process should be listed here. +However, any platform-specific changes should be listed in the +L section, instead. + +[ List changes as a =item entry ]. + +=over 4 + +=item * + +XXX + +=back + +=head1 Testing + +XXX Any significant changes to the testing of a freshly built perl should be +listed here. Changes which create B files in F go here as do any +large changes to the testing harness (e.g. when parallel testing was added). +Changes to existing files in F aren't worth summarising, although the bugs +that they represent may be covered elsewhere. + +[ List each test improvement as a =item entry ] + +=over 4 + +=item * + +The script F has been added, which tests interaction +of threads and directory handles. + +=back + +=head1 Platform Support + +XXX Any changes to platform support should be listed in the sections below. + +[ Within the sections, list each platform as a =item entry with specific +changes as paragraphs below it. ] + +=head2 New Platforms + +XXX List any platforms that this version of perl compiles on, that previous +versions did not. These will either be enabled by new files in the F +directories, or new subdirectories and F files at the top level of the +source tree. + +=over 4 + +=item XXX-some-platform + +XXX + +=back + +=head2 Discontinued Platforms + +XXX List any platforms that this version of perl no longer compiles on. + +=over 4 + +=item XXX-some-platform + +XXX + +=back + +=head2 Platform-Specific Notes + +XXX List any changes for specific platforms. This could include configuration +and compilation changes or changes in portability/compatibility. However, +changes within modules for platforms should generally be listed in the +L section. + +=over 4 + +=item IRIX + +Conversion of strings to floating-point numbers is now more accurate on +IRIX systems +L<[perl #32380]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=32380>. + +=item Mac OS X + +Early versions of Mac OS X (Darwin) had buggy implementations of the +C, C, C and C functions, so perl +would pretend they did not exist. + +These functions are now recognised on Mac OS 10.5 (Leopard; Darwin 9) and +higher, as they have been fixed +L<[perl #72990]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=72990>. + +=item OpenVOS + +perl now builds again with OpenVOS (formerly known as Stratus VOS) +L<[perl #78132]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=78132>. + +=item Windows + +C<$Config{gccversion}> is now set correctly when perl is built using the +mingw64 compiler from L +L<[perl #73754]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=73754>. + +The build process proceeds more smoothly with mingw and dmake when +F is in the PATH, due to a C fix. + +=back + +=head1 Internal Changes + +XXX Changes which affect the interface available to C code go here. +Other significant internal changes for future core maintainers should +be noted as well. + +[ List each test improvement as a =item entry ] + +=over 4 + +=item * + +See L, +above. + +=item * -=head1 Installation and Configuration Improvements +The C, C, C and +C functions have been added. These are like their +non-_flags counterparts, but allow one to specify whether get-magic is +processed. + +The C, C, C and C functions have +been replaced with wrappers around the new functions. + +=item * + +A new C function has been added. + +This is like C, but it lets the calling code decide whether +get-magic is handled. C is now a macro that calls the new +function. + +=item * + +A new macro, C, has been added. + +This is like C, except that it does not process magic. It uses the +new C function. + +=item * + +C no longer calls C on its second argument (the +source string) if the flags passed to it do not include SV_GMAGIC. So it +now matches what the documentation says it does. + +=back =head1 Selected Bug Fixes -=head1 New or Changed Diagnostics +XXX Important bug fixes in the core language are summarised here. +Bug fixes in files in F and F are best summarised in +L. + +[ List each fix as a =item entry ] + +=over 4 + +=item * + +A regular expression match in the right-hand side of a global substitution +(C) that is in the same scope will no longer cause match variables +to have the wrong values on subsequent iterations. This can happen when an +array or hash subscript is interpolated in the right-hand side, as in +C +L<[perl #19078]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=19078>. + +=item * + +Constant-folding used to cause + + $text =~ ( 1 ? /phoo/ : /bear/) + +to turn into + + $text =~ /phoo/ + +at compile time. Now it correctly matches against C<$_> +L<[perl #20444]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=20444>. + +=item * + +Parsing Perl code (either with string C or by loading modules) from +within a C block no longer causes the interpreter to crash +L<[perl #70614]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=70614>. + +=item * + +When C<-d> is used on the shebang (C<#!>) line, the debugger now has access +to the lines of the main program. In the past, this sometimes worked and +sometimes did not, depending on what order things happened to be arranged +in memory +L<[perl #71806]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=71806>. + +=item * + +The C or C operator now calls get-magic (e.g., the C +method of a tie) on its left-hand side just once, not twice +L<[perl #76814]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=76814>. + +=item * + +String comparison (C, C, C, C, C, C and +C) and logical not (C and C) operators no longer call magic +(e.g., tie methods) twice on their operands +L<[perl #76814]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=76814>. + +This bug was introduced in an earlier 5.13 release, and does not affect +perl 5.12. + +=item * + +When a tied (or other magic) variable is used as, or in, a regular +expression, it no longer has its C method called twice +L<[perl #76814]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=76814>. + +This bug was introduced in an earlier 5.13 release, and does not affect +perl 5.12. + +=item * -=head1 Changed Internals +The C<-C> command line option can now be followed by other options +L<[perl #72434]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=72434>. -=head1 New Tests +=item * + +Assigning a glob to a PVLV used to convert it to a plain string. Now it +works correctly, and a PVLV can hold a glob. This would happen when a +nonexistent hash or array element was passed to a subroutine: + + sub { $_[0] = *foo }->($hash{key}); + # $_[0] would have been the string "*main::foo" + +It also happened when a glob was assigned to, or returned from, an element +of a tied array or hash +L<[perl #36051]|http://rt.perl.org/rt3//Public/Bug/Display.html?id=36051>. + +=item * + +Creating a new thread when directory handles were open used to cause a +crash, because the handles were not cloned, but simply passed to the new +thread, resulting in a double free. + +Now directory handles are properly, on systems that have a C +function. On other systems, new threads simply do not inherit directory +handles from their parent threads +L<[perl #75154]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=75154>. + +=item * + +The regular expression parser no longer hangs when parsing C<\18> and +C<\88>. + +This bug was introduced in version 5.13.5 and did not affect earlier +versions +L<[perl #78058]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=78058>. + +=item * + +Subroutine redefinition works once more in the debugger +L<[perl #48332]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=48332>. + +=item * + +The C<&> C<|> C<^> bitwise operators no longer coerce read-only arguments +L<[perl #20661]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=20661>. + +=item * + +Stringifying a scalar containing -0.0 no longer has the affect of turning +false into true +L<[perl #45133]|http://rt.perl.org/rt3/Public/Bug/Display.html?id=45133>. + +=back =head1 Known Problems -=head1 Platform Specific Problems +XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any +tests that had to be Ced for the release would be noted here, unless +they were specific to a particular platform (see below). + +This is a list of some significant unfixed bugs, which are regressions +from either 5.XXX.XXX or 5.XXX.XXX. + +[ List each fix as a =item entry ] + +=over 4 + +=item * + +XXX + +=back + +=head1 Obituary + +XXX If any significant core contributor has died, we've added a short obituary +here. + +=head1 Errata + +=over 4 + +=item * + +Fixed a typo in L regarding array slices and smart matching + +=back + +=head1 Acknowledgements + +XXX The list of people to thank goes here. =head1 Reporting Bugs 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://bugs.perl.org/ . There may also be -information at http://www.perl.com/ , the Perl Home Page. +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 B program included with your release. Be sure to trim your bug down @@ -74,9 +748,20 @@ to a tiny but sufficient test case. Your bug report, along with the output of C, 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. + =head1 SEE ALSO -The F file for exhaustive details on what changed. +The F file for an explanation of how to view exhaustive details +on what changed. The F file for how to build Perl.