1=encoding utf8 2 3=head1 NAME 4 5perl5120delta - what is new for perl v5.12.0 6 7=head1 DESCRIPTION 8 9This document describes differences between the 5.10.0 release and the 105.12.0 release. 11 12Many of the bug fixes in 5.12.0 are already included in the 5.10.1 13maintenance release. 14 15You can see the list of those changes in the 5.10.1 release notes 16(L<perl5101delta>). 17 18 19=head1 Core Enhancements 20 21=head2 New C<package NAME VERSION> syntax 22 23This new syntax allows a module author to set the $VERSION of a namespace 24when the namespace is declared with 'package'. It eliminates the need 25for C<our $VERSION = ...> and similar constructs. E.g. 26 27 package Foo::Bar 1.23; 28 # $Foo::Bar::VERSION == 1.23 29 30There are several advantages to this: 31 32=over 33 34=item * 35 36C<$VERSION> is parsed in exactly the same way as C<use NAME VERSION> 37 38=item * 39 40C<$VERSION> is set at compile time 41 42=item * 43 44C<$VERSION> is a version object that provides proper overloading of 45comparison operators so comparing C<$VERSION> to decimal (1.23) or 46dotted-decimal (v1.2.3) version numbers works correctly. 47 48=item * 49 50Eliminates C<$VERSION = ...> and C<eval $VERSION> clutter 51 52=item * 53 54As it requires VERSION to be a numeric literal or v-string 55literal, it can be statically parsed by toolchain modules 56without C<eval> the way MM-E<gt>parse_version does for C<$VERSION = ...> 57 58=back 59 60It does not break old code with only C<package NAME>, but code that uses 61C<package NAME VERSION> will need to be restricted to perl 5.12.0 or newer 62This is analogous to the change to C<open> from two-args to three-args. 63Users requiring the latest Perl will benefit, and perhaps after several 64years, it will become a standard practice. 65 66 67However, C<package NAME VERSION> requires a new, 'strict' version 68number format. See L</"Version number formats"> for details. 69 70 71=head2 The C<...> operator 72 73A new operator, C<...>, nicknamed the Yada Yada operator, has been added. 74It is intended to mark placeholder code that is not yet implemented. 75See L<perlop/"Yada Yada Operator">. 76 77=head2 Implicit strictures 78 79Using the C<use VERSION> syntax with a version number greater or equal 80to 5.11.0 will lexically enable strictures just like C<use strict> 81would do (in addition to enabling features.) The following: 82 83 use 5.12.0; 84 85means: 86 87 use strict; 88 use feature ':5.12'; 89 90=head2 Unicode improvements 91 92Perl 5.12 comes with Unicode 5.2, the latest version available to 93us at the time of release. This version of Unicode was released in 94October 2009. See L<http://www.unicode.org/versions/Unicode5.2.0> for 95further details about what's changed in this version of the standard. 96See L<perlunicode> for instructions on installing and using other versions 97of Unicode. 98 99Additionally, Perl's developers have significantly improved Perl's Unicode 100implementation. For full details, see L</Unicode overhaul> below. 101 102=head2 Y2038 compliance 103 104Perl's core time-related functions are now Y2038 compliant. (It may not mean much to you, but your kids will love it!) 105 106=head2 qr overloading 107 108It is now possible to overload the C<qr//> operator, that is, 109conversion to regexp, like it was already possible to overload 110conversion to boolean, string or number of objects. It is invoked when 111an object appears on the right hand side of the C<=~> operator or when 112it is interpolated into a regexp. See L<overload>. 113 114=head2 Pluggable keywords 115 116Extension modules can now cleanly hook into the Perl parser to define 117new kinds of keyword-headed expression and compound statement. The 118syntax following the keyword is defined entirely by the extension. This 119allows a completely non-Perl sublanguage to be parsed inline, with the 120correct ops cleanly generated. 121 122See L<perlapi/PL_keyword_plugin> for the mechanism. The Perl core 123source distribution also includes a new module 124L<XS::APItest::KeywordRPN>, which implements reverse Polish notation 125arithmetic via pluggable keywords. This module is mainly used for test 126purposes, and is not normally installed, but also serves as an example 127of how to use the new mechanism. 128 129Perl's developers consider this feature to be experimental. We may remove 130it or change it in a backwards-incompatible way in Perl 5.14. 131 132=head2 APIs for more internals 133 134The lowest layers of the lexer and parts of the pad system now have C 135APIs available to XS extensions. These are necessary to support proper 136use of pluggable keywords, but have other uses too. The new APIs are 137experimental, and only cover a small proportion of what would be 138necessary to take full advantage of the core's facilities in these 139areas. It is intended that the Perl 5.13 development cycle will see the 140addition of a full range of clean, supported interfaces. 141 142Perl's developers consider this feature to be experimental. We may remove 143it or change it in a backwards-incompatible way in Perl 5.14. 144 145=head2 Overridable function lookup 146 147Where an extension module hooks the creation of rv2cv ops to modify the 148subroutine lookup process, this now works correctly for bareword 149subroutine calls. This means that prototypes on subroutines referenced 150this way will be processed correctly. (Previously bareword subroutine 151names were initially looked up, for parsing purposes, by an unhookable 152mechanism, so extensions could only properly influence subroutine names 153that appeared with an C<&> sigil.) 154 155=head2 A proper interface for pluggable Method Resolution Orders 156 157As of Perl 5.12.0 there is a new interface for plugging and using method 158resolution orders other than the default linear depth first search. 159The C3 method resolution order added in 5.10.0 has been re-implemented as 160a plugin, without changing its Perl-space interface. See L<perlmroapi> for 161more information. 162 163 164 165=head2 C<\N> experimental regex escape 166 167Perl now supports C<\N>, a new regex escape which you can think of as 168the inverse of C<\n>. It will match any character that is not a newline, 169independently from the presence or absence of the single line match 170modifier C</s>. It is not usable within a character class. C<\N{3}> 171means to match 3 non-newlines; C<\N{5,}> means to match at least 5. 172C<\N{NAME}> still means the character or sequence named C<NAME>, but 173C<NAME> no longer can be things like C<3>, or C<5,>. 174 175This will break a L<custom charnames translator|charnames/CUSTOM 176TRANSLATORS> which allows numbers for character names, as C<\N{3}> will 177now mean to match 3 non-newline characters, and not the character whose 178name is C<3>. (No name defined by the Unicode standard is a number, 179so only custom translators might be affected.) 180 181Perl's developers are somewhat concerned about possible user confusion 182with the existing C<\N{...}> construct which matches characters by their 183Unicode name. Consequently, this feature is experimental. We may remove 184it or change it in a backwards-incompatible way in Perl 5.14. 185 186=head2 DTrace support 187 188Perl now has some support for DTrace. See "DTrace support" in F<INSTALL>. 189 190=head2 Support for C<configure_requires> in CPAN module metadata 191 192Both C<CPAN> and C<CPANPLUS> now support the C<configure_requires> 193keyword in the F<META.yml> metadata file included in most recent CPAN 194distributions. This allows distribution authors to specify configuration 195prerequisites that must be installed before running F<Makefile.PL> 196or F<Build.PL>. 197 198See the documentation for C<ExtUtils::MakeMaker> or C<Module::Build> for 199more on how to specify C<configure_requires> when creating a distribution 200for CPAN. 201 202=head2 C<each>, C<keys>, C<values> are now more flexible 203 204The C<each>, C<keys>, C<values> function can now operate on arrays. 205 206=head2 C<when> as a statement modifier 207 208C<when> is now allowed to be used as a statement modifier. 209 210=head2 C<$,> flexibility 211 212The variable C<$,> may now be tied. 213 214=head2 // in when clauses 215 216// now behaves like || in when clauses 217 218=head2 Enabling warnings from your shell environment 219 220You can now set C<-W> from the C<PERL5OPT> environment variable 221 222=head2 C<delete local> 223 224C<delete local> now allows you to locally delete a hash entry. 225 226=head2 New support for Abstract namespace sockets 227 228Abstract namespace sockets are Linux-specific socket type that live in 229AF_UNIX family, slightly abusing it to be able to use arbitrary 230character arrays as addresses: They start with nul byte and are not 231terminated by nul byte, but with the length passed to the socket() 232system call. 233 234=head2 32-bit limit on substr arguments removed 235 236The 32-bit limit on C<substr> arguments has now been removed. The full 237range of the system's signed and unsigned integers is now available for 238the C<pos> and C<len> arguments. 239 240=head1 Potentially Incompatible Changes 241 242=head2 Deprecations warn by default 243 244Over the years, Perl's developers have deprecated a number of language 245features for a variety of reasons. Perl now defaults to issuing a 246warning if a deprecated language feature is used. Many of the deprecations 247Perl now warns you about have been deprecated for many years. You can 248find a list of what was deprecated in a given release of Perl in the 249C<perl5xxdelta.pod> file for that release. 250 251To disable this feature in a given lexical scope, you should use C<no 252warnings 'deprecated';> For information about which language features 253are deprecated and explanations of various deprecation warnings, please 254see L<perldiag>. See L</Deprecations> below for the list of features 255and modules Perl's developers have deprecated as part of this release. 256 257=head2 Version number formats 258 259Acceptable version number formats have been formalized into "strict" and 260"lax" rules. C<package NAME VERSION> takes a strict version number. 261C<UNIVERSAL::VERSION> and the L<version> object constructors take lax 262version numbers. Providing an invalid version will result in a fatal 263error. The version argument in C<use NAME VERSION> is first parsed as a 264numeric literal or v-string and then passed to C<UNIVERSAL::VERSION> 265(and must then pass the "lax" format test). 266 267These formats are documented fully in the L<version> module. To a first 268approximation, a "strict" version number is a positive decimal number 269(integer or decimal-fraction) without exponentiation or else a 270dotted-decimal v-string with a leading 'v' character and at least three 271components. A "lax" version number allows v-strings with fewer than 272three components or without a leading 'v'. Under "lax" rules, both 273decimal and dotted-decimal versions may have a trailing "alpha" 274component separated by an underscore character after a fractional or 275dotted-decimal component. 276 277The L<version> module adds C<version::is_strict> and C<version::is_lax> 278functions to check a scalar against these rules. 279 280=head2 @INC reorganization 281 282In C<@INC>, C<ARCHLIB> and C<PRIVLIB> now occur after the current 283version's C<site_perl> and C<vendor_perl>. Modules installed into 284C<site_perl> and C<vendor_perl> will now be loaded in preference to 285those installed in C<ARCHLIB> and C<PRIVLIB>. 286 287 288=head2 REGEXPs are now first class 289 290Internally, Perl now treats compiled regular expressions (such as 291those created with C<qr//>) as first class entities. Perl modules which 292serialize, deserialize or otherwise have deep interaction with Perl's 293internal data structures need to be updated for this change. Most 294affected CPAN modules have already been updated as of this writing. 295 296=head2 Switch statement changes 297 298The C<given>/C<when> switch statement handles complex statements better 299than Perl 5.10.0 did (These enhancements are also available in 3005.10.1 and subsequent 5.10 releases.) There are two new cases where 301C<when> now interprets its argument as a boolean, instead of an 302expression to be used in a smart match: 303 304=over 305 306=item flip-flop operators 307 308The C<..> and C<...> flip-flop operators are now evaluated in boolean 309context, following their usual semantics; see L<perlop/"Range Operators">. 310 311Note that, as in perl 5.10.0, C<when (1..10)> will not work to test 312whether a given value is an integer between 1 and 10; you should use 313C<when ([1..10])> instead (note the array reference). 314 315However, contrary to 5.10.0, evaluating the flip-flop operators in 316boolean context ensures it can now be useful in a C<when()>, notably 317for implementing bistable conditions, like in: 318 319 when (/^=begin/ .. /^=end/) { 320 # do something 321 } 322 323=item defined-or operator 324 325A compound expression involving the defined-or operator, as in 326C<when (expr1 // expr2)>, will be treated as boolean if the first 327expression is boolean. (This just extends the existing rule that applies 328to the regular or operator, as in C<when (expr1 || expr2)>.) 329 330=back 331 332=head2 Smart match changes 333 334Since Perl 5.10.0, Perl's developers have made a number of changes to 335the smart match operator. These, of course, also alter the behaviour 336of the switch statements where smart matching is implicitly used. 337These changes were also made for the 5.10.1 release, and will remain in 338subsequent 5.10 releases. 339 340=head3 Changes to type-based dispatch 341 342The smart match operator C<~~> is no longer commutative. The behaviour of 343a smart match now depends primarily on the type of its right hand 344argument. Moreover, its semantics have been adjusted for greater 345consistency or usefulness in several cases. While the general backwards 346compatibility is maintained, several changes must be noted: 347 348=over 4 349 350=item * 351 352Code references with an empty prototype are no longer treated specially. 353They are passed an argument like the other code references (even if they 354choose to ignore it). 355 356=item * 357 358C<%hash ~~ sub {}> and C<@array ~~ sub {}> now test that the subroutine 359returns a true value for each key of the hash (or element of the 360array), instead of passing the whole hash or array as a reference to 361the subroutine. 362 363=item * 364 365Due to the commutativity breakage, code references are no longer 366treated specially when appearing on the left of the C<~~> operator, 367but like any vulgar scalar. 368 369=item * 370 371C<undef ~~ %hash> is always false (since C<undef> can't be a key in a 372hash). No implicit conversion to C<""> is done (as was the case in perl 3735.10.0). 374 375=item * 376 377C<$scalar ~~ @array> now always distributes the smart match across the 378elements of the array. It's true if one element in @array verifies 379C<$scalar ~~ $element>. This is a generalization of the old behaviour 380that tested whether the array contained the scalar. 381 382=back 383 384The full dispatch table for the smart match operator is given in 385L<perlsyn/"Smart matching in detail">. 386 387=head3 Smart match and overloading 388 389According to the rule of dispatch based on the rightmost argument type, 390when an object overloading C<~~> appears on the right side of the 391operator, the overload routine will always be called (with a 3rd argument 392set to a true value, see L<overload>.) However, when the object will 393appear on the left, the overload routine will be called only when the 394rightmost argument is a simple scalar. This way, distributivity of smart 395match across arrays is not broken, as well as the other behaviours with 396complex types (coderefs, hashes, regexes). Thus, writers of overloading 397routines for smart match mostly need to worry only with comparing 398against a scalar, and possibly with stringification overloading; the 399other common cases will be automatically handled consistently. 400 401C<~~> will now refuse to work on objects that do not overload it (in order 402to avoid relying on the object's underlying structure). (However, if the 403object overloads the stringification or the numification operators, and 404if overload fallback is active, it will be used instead, as usual.) 405 406=head2 Other potentially incompatible changes 407 408=over 4 409 410=item * 411 412The definitions of a number of Unicode properties have changed to match 413those of the current Unicode standard. These are listed above under 414L</Unicode overhaul>. This change may break code that expects the old 415definitions. 416 417=item * 418 419The boolkeys op has moved to the group of hash ops. This breaks binary 420compatibility. 421 422=item * 423 424Filehandles are now always blessed into C<IO::File>. 425 426The previous behaviour was to bless Filehandles into L<FileHandle> 427(an empty proxy class) if it was loaded into memory and otherwise 428to bless them into C<IO::Handle>. 429 430=item * 431 432The semantics of C<use feature :5.10*> have changed slightly. 433See L</"Modules and Pragmata"> for more information. 434 435=item * 436 437Perl's developers now use git, rather than Perforce. This should be 438a purely internal change only relevant to people actively working on 439the core. However, you may see minor difference in perl as a consequence 440of the change. For example in some of details of the output of C<perl 441-V>. See L<perlrepository> for more information. 442 443=item * 444 445As part of the C<Test::Harness> 2.x to 3.x upgrade, the experimental 446C<Test::Harness::Straps> module has been removed. 447See L</"Modules and Pragmata"> for more details. 448 449=item * 450 451As part of the C<ExtUtils::MakeMaker> upgrade, the 452C<ExtUtils::MakeMaker::bytes> and C<ExtUtils::MakeMaker::vmsish> modules 453have been removed from this distribution. 454 455=item * 456 457C<Module::CoreList> no longer contains the C<%:patchlevel> hash. 458 459=item * 460 461C<length undef> now returns undef. 462 463=item * 464 465Unsupported private C API functions are now declared "static" to prevent 466leakage to Perl's public API. 467 468=item * 469 470To support the bootstrapping process, F<miniperl> no longer builds with 471UTF-8 support in the regexp engine. 472 473This allows a build to complete with PERL_UNICODE set and a UTF-8 locale. 474Without this there's a bootstrapping problem, as miniperl can't load 475the UTF-8 components of the regexp engine, because they're not yet built. 476 477=item * 478 479F<miniperl>'s @INC is now restricted to just C<-I...>, the split of 480C<$ENV{PERL5LIB}>, and "C<.>" 481 482=item * 483 484A space or a newline is now required after a C<"#line XXX"> directive. 485 486=item * 487 488Tied filehandles now have an additional method EOF which provides the 489EOF type. 490 491=item * 492 493To better match all other flow control statements, C<foreach> may no 494longer be used as an attribute. 495 496=item * 497 498Perl's command-line switch "-P", which was deprecated in version 5.10.0, has 499now been removed. The CPAN module C<< Filter::cpp >> can be used as an 500alternative. 501 502=back 503 504 505=head1 Deprecations 506 507From time to time, Perl's developers find it necessary to deprecate 508features or modules we've previously shipped as part of the core 509distribution. We are well aware of the pain and frustration that a 510backwards-incompatible change to Perl can cause for developers building 511or maintaining software in Perl. You can be sure that when we deprecate 512a functionality or syntax, it isn't a choice we make lightly. Sometimes, 513we choose to deprecate functionality or syntax because it was found to 514be poorly designed or implemented. Sometimes, this is because they're 515holding back other features or causing performance problems. Sometimes, 516the reasons are more complex. Wherever possible, we try to keep deprecated 517functionality available to developers in its previous form for at least 518one major release. So long as a deprecated feature isn't actively 519disrupting our ability to maintain and extend Perl, we'll try to leave 520it in place as long as possible. 521 522The following items are now deprecated: 523 524=over 525 526=item suidperl 527 528C<suidperl> is no longer part of Perl. It used to provide a mechanism to 529emulate setuid permission bits on systems that don't support it properly. 530 531=item Use of C<:=> to mean an empty attribute list 532 533An accident of Perl's parser meant that these constructions were all 534equivalent: 535 536 my $pi := 4; 537 my $pi : = 4; 538 my $pi : = 4; 539 540with the C<:> being treated as the start of an attribute list, which 541ends before the C<=>. As whitespace is not significant here, all are 542parsed as an empty attribute list, hence all the above are equivalent 543to, and better written as 544 545 my $pi = 4; 546 547because no attribute processing is done for an empty list. 548 549As is, this meant that C<:=> cannot be used as a new token, without 550silently changing the meaning of existing code. Hence that particular 551form is now deprecated, and will become a syntax error. If it is 552absolutely necessary to have empty attribute lists (for example, 553because of a code generator) then avoid the warning by adding a space 554before the C<=>. 555 556=item C<< UNIVERSAL->import() >> 557 558The method C<< UNIVERSAL->import() >> is now deprecated. Attempting to 559pass import arguments to a C<use UNIVERSAL> statement will result in a 560deprecation warning. 561 562=item Use of "goto" to jump into a construct 563 564Using C<goto> to jump from an outer scope into an inner scope is now 565deprecated. This rare use case was causing problems in the 566implementation of scopes. 567 568=item Custom character names in \N{name} that don't look like names 569 570In C<\N{I<name>}>, I<name> can be just about anything. The standard 571Unicode names have a very limited domain, but a custom name translator 572could create names that are, for example, made up entirely of punctuation 573symbols. It is now deprecated to make names that don't begin with an 574alphabetic character, and aren't alphanumeric or contain other than 575a very few other characters, namely spaces, dashes, parentheses 576and colons. Because of the added meaning of C<\N> (See L</C<\N> 577experimental regex escape>), names that look like curly brace -enclosed 578quantifiers won't work. For example, C<\N{3,4}> now means to match 3 to 5794 non-newlines; before a custom name C<3,4> could have been created. 580 581=item Deprecated Modules 582 583The following modules will be removed from the core distribution in a 584future release, and should be installed from CPAN instead. Distributions 585on CPAN which require these should add them to their prerequisites. The 586core versions of these modules warnings will issue a deprecation warning. 587 588If you ship a packaged version of Perl, either alone or as part of a 589larger system, then you should carefully consider the repercussions of 590core module deprecations. You may want to consider shipping your default 591build of Perl with packages for some or all deprecated modules which 592install into C<vendor> or C<site> perl library directories. This will 593inhibit the deprecation warnings. 594 595Alternatively, you may want to consider patching F<lib/deprecate.pm> 596to provide deprecation warnings specific to your packaging system 597or distribution of Perl, consistent with how your packaging system 598or distribution manages a staged transition from a release where the 599installation of a single package provides the given functionality, to 600a later release where the system administrator needs to know to install 601multiple packages to get that same functionality. 602 603You can silence these deprecation warnings by installing the modules 604in question from CPAN. To install the latest version of all of them, 605just install C<Task::Deprecations::5_12>. 606 607=over 608 609=item L<Class::ISA> 610 611=item L<Pod::Plainer> 612 613=item L<Shell> 614 615=item L<Switch> 616 617Switch is buggy and should be avoided. You may find Perl's new 618C<given>/C<when> feature a suitable replacement. See L<perlsyn/"Switch 619statements"> for more information. 620 621=back 622 623=item Assignment to $[ 624 625=item Use of the attribute :locked on subroutines 626 627=item Use of "locked" with the attributes pragma 628 629=item Use of "unique" with the attributes pragma 630 631=item Perl_pmflag 632 633C<Perl_pmflag> is no longer part of Perl's public API. Calling it now 634generates a deprecation warning, and it will be removed in a future 635release. Although listed as part of the API, it was never documented, 636and only ever used in F<toke.c>, and prior to 5.10, F<regcomp.c>. In 637core, it has been replaced by a static function. 638 639=item Numerous Perl 4-era libraries 640 641F<termcap.pl>, F<tainted.pl>, F<stat.pl>, F<shellwords.pl>, F<pwd.pl>, 642F<open3.pl>, F<open2.pl>, F<newgetopt.pl>, F<look.pl>, F<find.pl>, 643F<finddepth.pl>, F<importenv.pl>, F<hostname.pl>, F<getopts.pl>, 644F<getopt.pl>, F<getcwd.pl>, F<flush.pl>, F<fastcwd.pl>, F<exceptions.pl>, 645F<ctime.pl>, F<complete.pl>, F<cacheout.pl>, F<bigrat.pl>, F<bigint.pl>, 646F<bigfloat.pl>, F<assert.pl>, F<abbrev.pl>, F<dotsh.pl>, and 647F<timelocal.pl> are all now deprecated. Earlier, Perl's developers 648intended to remove these libraries from Perl's core for the 5.14.0 release. 649 650During final testing before the release of 5.12.0, several developers 651discovered current production code using these ancient libraries, some 652inside the Perl core itself. Accordingly, the pumpking granted them 653a stay of execution. They will begin to warn about their deprecation 654in the 5.14.0 release and will be removed in the 5.16.0 release. 655 656 657=back 658 659=head1 Unicode overhaul 660 661Perl's developers have made a concerted effort to update Perl to be in 662sync with the latest Unicode standard. Changes for this include: 663 664Perl can now handle every Unicode character property. New documentation, 665L<perluniprops>, lists all available non-Unihan character properties. By 666default, perl does not expose Unihan, deprecated or Unicode-internal 667properties. See below for more details on these; there is also a section 668in the pod listing them, and explaining why they are not exposed. 669 670Perl now fully supports the Unicode compound-style of using C<=> 671and C<:> in writing regular expressions: C<\p{property=value}> and 672C<\p{property:value}> (both of which mean the same thing). 673 674Perl now fully supports the Unicode loose matching rules for text between 675the braces in C<\p{...}> constructs. In addition, Perl allows underscores 676between digits of numbers. 677 678Perl now accepts all the Unicode-defined synonyms for properties and 679property values. 680 681C<qr/\X/>, which matches a Unicode logical character, has 682been expanded to work better with various Asian languages. It 683now is defined as an I<extended grapheme cluster>. (See 684L<http://www.unicode.org/reports/tr29/>). Anything matched previously 685and that made sense will continue to be accepted. Additionally: 686 687=over 688 689=item * 690 691C<\X> will not break apart a C<S<CR LF>> sequence. 692 693=item * 694 695C<\X> will now match a sequence which includes the C<ZWJ> and C<ZWNJ> 696characters. 697 698=item * 699 700C<\X> will now always match at least one character, including an initial 701mark. Marks generally come after a base character, but it is possible in 702Unicode to have them in isolation, and C<\X> will now handle that case, 703for example at the beginning of a line, or after a C<ZWSP>. And this is 704the part where C<\X> doesn't match the things that it used to that don't 705make sense. Formerly, for example, you could have the nonsensical case 706of an accented LF. 707 708=item * 709 710C<\X> will now match a (Korean) Hangul syllable sequence, and the Thai 711and Lao exception cases. 712 713=back 714 715Otherwise, this change should be transparent for the non-affected 716languages. 717 718C<\p{...}> matches using the Canonical_Combining_Class property were 719completely broken in previous releases of Perl. They should now work 720correctly. 721 722Before Perl 5.12, the Unicode C<Decomposition_Type=Compat> property 723and a Perl extension had the same name, which led to neither matching 724all the correct values (with more than 100 mistakes in one, and several 725thousand in the other). The Perl extension has now been renamed to be 726C<Decomposition_Type=Noncanonical> (short: C<dt=noncanon>). It has the 727same meaning as was previously intended, namely the union of all the 728non-canonical Decomposition types, with Unicode C<Compat> being just 729one of those. 730 731C<\p{Decomposition_Type=Canonical}> now includes the Hangul syllables. 732 733C<\p{Uppercase}> and C<\p{Lowercase}> now work as the Unicode standard 734says they should. This means they each match a few more characters than 735they used to. 736 737C<\p{Cntrl}> now matches the same characters as C<\p{Control}>. This 738means it no longer will match Private Use (gc=co), Surrogates (gc=cs), 739nor Format (gc=cf) code points. The Format code points represent the 740biggest possible problem. All but 36 of them are either officially 741deprecated or strongly discouraged from being used. Of those 36, likely 742the most widely used are the soft hyphen (U+00AD), and BOM, ZWSP, ZWNJ, 743WJ, and similar characters, plus bidirectional controls. 744 745C<\p{Alpha}> now matches the same characters as C<\p{Alphabetic}>. Before 7465.12, Perl's definition included a number of things that aren't 747really alpha (all marks) while omitting many that were. The definitions 748of C<\p{Alnum}> and C<\p{Word}> depend on Alpha's definition and have 749changed accordingly. 750 751C<\p{Word}> no longer incorrectly matches non-word characters such 752as fractions. 753 754C<\p{Print}> no longer matches the line control characters: Tab, LF, 755CR, FF, VT, and NEL. This brings it in line with standards and the 756documentation. 757 758C<\p{XDigit}> now matches the same characters as C<\p{Hex_Digit}>. This 759means that in addition to the characters it currently matches, 760C<[A-Fa-f0-9]>, it will also match the 22 fullwidth equivalents, for 761example U+FF10: FULLWIDTH DIGIT ZERO. 762 763The Numeric type property has been extended to include the Unihan 764characters. 765 766There is a new Perl extension, the 'Present_In', or simply 'In', 767property. This is an extension of the Unicode Age property, but 768C<\p{In=5.0}> matches any code point whose usage has been determined 769I<as of> Unicode version 5.0. The C<\p{Age=5.0}> only matches code points 770added in I<precisely> version 5.0. 771 772A number of properties now have the correct values for unassigned 773code points. The affected properties are Bidi_Class, East_Asian_Width, 774Joining_Type, Decomposition_Type, Hangul_Syllable_Type, Numeric_Type, 775and Line_Break. 776 777The Default_Ignorable_Code_Point, ID_Continue, and ID_Start properties 778are now up to date with current Unicode definitions. 779 780Earlier versions of Perl erroneously exposed certain properties that 781are supposed to be Unicode internal-only. Use of these in regular 782expressions will now generate, if enabled, a deprecation warning message. 783The properties are: Other_Alphabetic, Other_Default_Ignorable_Code_Point, 784Other_Grapheme_Extend, Other_ID_Continue, Other_ID_Start, Other_Lowercase, 785Other_Math, and Other_Uppercase. 786 787It is now possible to change which Unicode properties Perl understands 788on a per-installation basis. As mentioned above, certain properties 789are turned off by default. These include all the Unihan properties 790(which should be accessible via the CPAN module Unicode::Unihan) and any 791deprecated or Unicode internal-only property that Perl has never exposed. 792 793The generated files in the C<lib/unicore/To> directory are now more 794clearly marked as being stable, directly usable by applications. New hash 795entries in them give the format of the normal entries, which allows for 796easier machine parsing. Perl can generate files in this directory for 797any property, though most are suppressed. You can find instructions 798for changing which are written in L<perluniprops>. 799 800=head1 Modules and Pragmata 801 802=head2 New Modules and Pragmata 803 804=over 4 805 806=item C<autodie> 807 808C<autodie> is a new lexically-scoped alternative for the C<Fatal> module. 809The bundled version is 2.06_01. Note that in this release, using a string 810eval when C<autodie> is in effect can cause the autodie behaviour to leak 811into the surrounding scope. See L<autodie/"BUGS"> for more details. 812 813Version 2.06_01 has been added to the Perl core. 814 815=item C<Compress::Raw::Bzip2> 816 817Version 2.024 has been added to the Perl core. 818 819=item C<overloading> 820 821C<overloading> allows you to lexically disable or enable overloading 822for some or all operations. 823 824Version 0.001 has been added to the Perl core. 825 826=item C<parent> 827 828C<parent> establishes an ISA relationship with base classes at compile 829time. It provides the key feature of C<base> without further unwanted 830behaviors. 831 832Version 0.223 has been added to the Perl core. 833 834=item C<Parse::CPAN::Meta> 835 836Version 1.40 has been added to the Perl core. 837 838=item C<VMS::DCLsym> 839 840Version 1.03 has been added to the Perl core. 841 842=item C<VMS::Stdio> 843 844Version 2.4 has been added to the Perl core. 845 846=item C<XS::APItest::KeywordRPN> 847 848Version 0.003 has been added to the Perl core. 849 850=back 851 852=head2 Updated Pragmata 853 854=over 4 855 856=item C<base> 857 858Upgraded from version 2.13 to 2.15. 859 860=item C<bignum> 861 862Upgraded from version 0.22 to 0.23. 863 864=item C<charnames> 865 866C<charnames> now contains the Unicode F<NameAliases.txt> database file. 867This has the effect of adding some extra C<\N> character names that 868formerly wouldn't have been recognised; for example, C<"\N{LATIN CAPITAL 869LETTER GHA}">. 870 871Upgraded from version 1.06 to 1.07. 872 873=item C<constant> 874 875Upgraded from version 1.13 to 1.20. 876 877=item C<diagnostics> 878 879C<diagnostics> now supports %.0f formatting internally. 880 881C<diagnostics> no longer suppresses C<Use of uninitialized value in range 882(or flip)> warnings. [perl #71204] 883 884Upgraded from version 1.17 to 1.19. 885 886=item C<feature> 887 888In C<feature>, the meaning of the C<:5.10> and C<:5.10.X> feature 889bundles has changed slightly. The last component, if any (i.e. C<X>) is 890simply ignored. This is predicated on the assumption that new features 891will not, in general, be added to maintenance releases. So C<:5.10> 892and C<:5.10.X> have identical effect. This is a change to the behaviour 893documented for 5.10.0. 894 895C<feature> now includes the C<unicode_strings> feature: 896 897 use feature "unicode_strings"; 898 899This pragma turns on Unicode semantics for the case-changing operations 900(C<uc>, C<lc>, C<ucfirst>, C<lcfirst>) on strings that don't have the 901internal UTF-8 flag set, but that contain single-byte characters between 902128 and 255. 903 904Upgraded from version 1.11 to 1.16. 905 906=item C<less> 907 908C<less> now includes the C<stash_name> method to allow subclasses of 909C<less> to pick where in %^H to store their stash. 910 911Upgraded from version 0.02 to 0.03. 912 913=item C<lib> 914 915Upgraded from version 0.5565 to 0.62. 916 917=item C<mro> 918 919C<mro> is now implemented as an XS extension. The documented interface has 920not changed. Code relying on the implementation detail that some C<mro::> 921methods happened to be available at all times gets to "keep both pieces". 922 923Upgraded from version 1.00 to 1.02. 924 925=item C<overload> 926 927C<overload> now allow overloading of 'qr'. 928 929Upgraded from version 1.06 to 1.10. 930 931=item C<threads> 932 933Upgraded from version 1.67 to 1.75. 934 935=item C<threads::shared> 936 937Upgraded from version 1.14 to 1.32. 938 939=item C<version> 940 941C<version> now has support for L</Version number formats> as described 942earlier in this document and in its own documentation. 943 944Upgraded from version 0.74 to 0.82. 945 946=item C<warnings> 947 948C<warnings> has a new C<warnings::fatal_enabled()> function. It also 949includes a new C<illegalproto> warning category. See also L</New or 950Changed Diagnostics> for this change. 951 952Upgraded from version 1.06 to 1.09. 953 954=back 955 956=head2 Updated Modules 957 958=over 4 959 960=item C<Archive::Extract> 961 962Upgraded from version 0.24 to 0.38. 963 964=item C<Archive::Tar> 965 966Upgraded from version 1.38 to 1.54. 967 968=item C<Attribute::Handlers> 969 970Upgraded from version 0.79 to 0.87. 971 972=item C<AutoLoader> 973 974Upgraded from version 5.63 to 5.70. 975 976=item C<B::Concise> 977 978Upgraded from version 0.74 to 0.78. 979 980=item C<B::Debug> 981 982Upgraded from version 1.05 to 1.12. 983 984=item C<B::Deparse> 985 986Upgraded from version 0.83 to 0.96. 987 988=item C<B::Lint> 989 990Upgraded from version 1.09 to 1.11_01. 991 992=item C<CGI> 993 994Upgraded from version 3.29 to 3.48. 995 996=item C<Class::ISA> 997 998Upgraded from version 0.33 to 0.36. 999 1000NOTE: C<Class::ISA> is deprecated and may be removed from a future 1001version of Perl. 1002 1003=item C<Compress::Raw::Zlib> 1004 1005Upgraded from version 2.008 to 2.024. 1006 1007=item C<CPAN> 1008 1009Upgraded from version 1.9205 to 1.94_56. 1010 1011=item C<CPANPLUS> 1012 1013Upgraded from version 0.84 to 0.90. 1014 1015=item C<CPANPLUS::Dist::Build> 1016 1017Upgraded from version 0.06_02 to 0.46. 1018 1019=item C<Data::Dumper> 1020 1021Upgraded from version 2.121_14 to 2.125. 1022 1023=item C<DB_File> 1024 1025Upgraded from version 1.816_1 to 1.820. 1026 1027=item C<Devel::PPPort> 1028 1029Upgraded from version 3.13 to 3.19. 1030 1031=item C<Digest> 1032 1033Upgraded from version 1.15 to 1.16. 1034 1035=item C<Digest::MD5> 1036 1037Upgraded from version 2.36_01 to 2.39. 1038 1039=item C<Digest::SHA> 1040 1041Upgraded from version 5.45 to 5.47. 1042 1043=item C<Encode> 1044 1045Upgraded from version 2.23 to 2.39. 1046 1047=item C<Exporter> 1048 1049Upgraded from version 5.62 to 5.64_01. 1050 1051=item C<ExtUtils::CBuilder> 1052 1053Upgraded from version 0.21 to 0.27. 1054 1055=item C<ExtUtils::Command> 1056 1057Upgraded from version 1.13 to 1.16. 1058 1059=item C<ExtUtils::Constant> 1060 1061Upgraded from version 0.2 to 0.22. 1062 1063=item C<ExtUtils::Install> 1064 1065Upgraded from version 1.44 to 1.55. 1066 1067=item C<ExtUtils::MakeMaker> 1068 1069Upgraded from version 6.42 to 6.56. 1070 1071=item C<ExtUtils::Manifest> 1072 1073Upgraded from version 1.51_01 to 1.57. 1074 1075=item C<ExtUtils::ParseXS> 1076 1077Upgraded from version 2.18_02 to 2.21. 1078 1079=item C<File::Fetch> 1080 1081Upgraded from version 0.14 to 0.24. 1082 1083=item C<File::Path> 1084 1085Upgraded from version 2.04 to 2.08_01. 1086 1087=item C<File::Temp> 1088 1089Upgraded from version 0.18 to 0.22. 1090 1091=item C<Filter::Simple> 1092 1093Upgraded from version 0.82 to 0.84. 1094 1095=item C<Filter::Util::Call> 1096 1097Upgraded from version 1.07 to 1.08. 1098 1099=item C<Getopt::Long> 1100 1101Upgraded from version 2.37 to 2.38. 1102 1103=item C<IO> 1104 1105Upgraded from version 1.23_01 to 1.25_02. 1106 1107=item C<IO::Zlib> 1108 1109Upgraded from version 1.07 to 1.10. 1110 1111=item C<IPC::Cmd> 1112 1113Upgraded from version 0.40_1 to 0.54. 1114 1115=item C<IPC::SysV> 1116 1117Upgraded from version 1.05 to 2.01. 1118 1119=item C<Locale::Maketext> 1120 1121Upgraded from version 1.12 to 1.14. 1122 1123=item C<Locale::Maketext::Simple> 1124 1125Upgraded from version 0.18 to 0.21. 1126 1127=item C<Log::Message> 1128 1129Upgraded from version 0.01 to 0.02. 1130 1131=item C<Log::Message::Simple> 1132 1133Upgraded from version 0.04 to 0.06. 1134 1135=item C<Math::BigInt> 1136 1137Upgraded from version 1.88 to 1.89_01. 1138 1139=item C<Math::BigInt::FastCalc> 1140 1141Upgraded from version 0.16 to 0.19. 1142 1143=item C<Math::BigRat> 1144 1145Upgraded from version 0.21 to 0.24. 1146 1147=item C<Math::Complex> 1148 1149Upgraded from version 1.37 to 1.56. 1150 1151=item C<Memoize> 1152 1153Upgraded from version 1.01_02 to 1.01_03. 1154 1155=item C<MIME::Base64> 1156 1157Upgraded from version 3.07_01 to 3.08. 1158 1159=item C<Module::Build> 1160 1161Upgraded from version 0.2808_01 to 0.3603. 1162 1163=item C<Module::CoreList> 1164 1165Upgraded from version 2.12 to 2.29. 1166 1167=item C<Module::Load> 1168 1169Upgraded from version 0.12 to 0.16. 1170 1171=item C<Module::Load::Conditional> 1172 1173Upgraded from version 0.22 to 0.34. 1174 1175=item C<Module::Loaded> 1176 1177Upgraded from version 0.01 to 0.06. 1178 1179=item C<Module::Pluggable> 1180 1181Upgraded from version 3.6 to 3.9. 1182 1183=item C<Net::Ping> 1184 1185Upgraded from version 2.33 to 2.36. 1186 1187=item C<NEXT> 1188 1189Upgraded from version 0.60_01 to 0.64. 1190 1191=item C<Object::Accessor> 1192 1193Upgraded from version 0.32 to 0.36. 1194 1195=item C<Package::Constants> 1196 1197Upgraded from version 0.01 to 0.02. 1198 1199=item C<PerlIO> 1200 1201Upgraded from version 1.04 to 1.06. 1202 1203=item C<Pod::Parser> 1204 1205Upgraded from version 1.35 to 1.37. 1206 1207=item C<Pod::Perldoc> 1208 1209Upgraded from version 3.14_02 to 3.15_02. 1210 1211=item C<Pod::Plainer> 1212 1213Upgraded from version 0.01 to 1.02. 1214 1215NOTE: C<Pod::Plainer> is deprecated and may be removed from a future 1216version of Perl. 1217 1218=item C<Pod::Simple> 1219 1220Upgraded from version 3.05 to 3.13. 1221 1222=item C<Safe> 1223 1224Upgraded from version 2.12 to 2.22. 1225 1226=item C<SelfLoader> 1227 1228Upgraded from version 1.11 to 1.17. 1229 1230=item C<Storable> 1231 1232Upgraded from version 2.18 to 2.22. 1233 1234=item C<Switch> 1235 1236Upgraded from version 2.13 to 2.16. 1237 1238NOTE: C<Switch> is deprecated and may be removed from a future version 1239of Perl. 1240 1241=item C<Sys::Syslog> 1242 1243Upgraded from version 0.22 to 0.27. 1244 1245=item C<Term::ANSIColor> 1246 1247Upgraded from version 1.12 to 2.02. 1248 1249=item C<Term::UI> 1250 1251Upgraded from version 0.18 to 0.20. 1252 1253=item C<Test> 1254 1255Upgraded from version 1.25 to 1.25_02. 1256 1257=item C<Test::Harness> 1258 1259Upgraded from version 2.64 to 3.17. 1260 1261=item C<Test::Simple> 1262 1263Upgraded from version 0.72 to 0.94. 1264 1265=item C<Text::Balanced> 1266 1267Upgraded from version 2.0.0 to 2.02. 1268 1269=item C<Text::ParseWords> 1270 1271Upgraded from version 3.26 to 3.27. 1272 1273=item C<Text::Soundex> 1274 1275Upgraded from version 3.03 to 3.03_01. 1276 1277=item C<Thread::Queue> 1278 1279Upgraded from version 2.00 to 2.11. 1280 1281=item C<Thread::Semaphore> 1282 1283Upgraded from version 2.01 to 2.09. 1284 1285=item C<Tie::RefHash> 1286 1287Upgraded from version 1.37 to 1.38. 1288 1289=item C<Time::HiRes> 1290 1291Upgraded from version 1.9711 to 1.9719. 1292 1293=item C<Time::Local> 1294 1295Upgraded from version 1.18 to 1.1901_01. 1296 1297=item C<Time::Piece> 1298 1299Upgraded from version 1.12 to 1.15. 1300 1301=item C<Unicode::Collate> 1302 1303Upgraded from version 0.52 to 0.52_01. 1304 1305=item C<Unicode::Normalize> 1306 1307Upgraded from version 1.02 to 1.03. 1308 1309=item C<Win32> 1310 1311Upgraded from version 0.34 to 0.39. 1312 1313=item C<Win32API::File> 1314 1315Upgraded from version 0.1001_01 to 0.1101. 1316 1317=item C<XSLoader> 1318 1319Upgraded from version 0.08 to 0.10. 1320 1321=back 1322 1323=head2 Removed Modules and Pragmata 1324 1325=over 4 1326 1327=item C<attrs> 1328 1329Removed from the Perl core. Prior version was 1.02. 1330 1331=item C<CPAN::API::HOWTO> 1332 1333Removed from the Perl core. Prior version was 'undef'. 1334 1335=item C<CPAN::DeferedCode> 1336 1337Removed from the Perl core. Prior version was 5.50. 1338 1339=item C<CPANPLUS::inc> 1340 1341Removed from the Perl core. Prior version was 'undef'. 1342 1343=item C<DCLsym> 1344 1345Removed from the Perl core. Prior version was 1.03. 1346 1347=item C<ExtUtils::MakeMaker::bytes> 1348 1349Removed from the Perl core. Prior version was 6.42. 1350 1351=item C<ExtUtils::MakeMaker::vmsish> 1352 1353Removed from the Perl core. Prior version was 6.42. 1354 1355=item C<Stdio> 1356 1357Removed from the Perl core. Prior version was 2.3. 1358 1359=item C<Test::Harness::Assert> 1360 1361Removed from the Perl core. Prior version was 0.02. 1362 1363=item C<Test::Harness::Iterator> 1364 1365Removed from the Perl core. Prior version was 0.02. 1366 1367=item C<Test::Harness::Point> 1368 1369Removed from the Perl core. Prior version was 0.01. 1370 1371=item C<Test::Harness::Results> 1372 1373Removed from the Perl core. Prior version was 0.01. 1374 1375=item C<Test::Harness::Straps> 1376 1377Removed from the Perl core. Prior version was 0.26_01. 1378 1379=item C<Test::Harness::Util> 1380 1381Removed from the Perl core. Prior version was 0.01. 1382 1383=item C<XSSymSet> 1384 1385Removed from the Perl core. Prior version was 1.1. 1386 1387=back 1388 1389=head2 Deprecated Modules and Pragmata 1390 1391See L</Deprecated Modules> above. 1392 1393 1394=head1 Documentation 1395 1396=head2 New Documentation 1397 1398=over 4 1399 1400=item * 1401 1402L<perlhaiku> contains instructions on how to build perl for the Haiku 1403platform. 1404 1405=item * 1406 1407L<perlmroapi> describes the new interface for pluggable Method Resolution 1408Orders. 1409 1410=item * 1411 1412L<perlperf>, by Richard Foley, provides an introduction to the use of 1413performance and optimization techniques which can be used with particular 1414reference to perl programs. 1415 1416=item * 1417 1418L<perlrepository> describes how to access the perl source using the I<git> 1419version control system. 1420 1421=item * 1422 1423L<perlpolicy> extends the "Social contract about contributed modules" into 1424the beginnings of a document on Perl porting policies. 1425 1426=back 1427 1428=head2 Changes to Existing Documentation 1429 1430 1431=over 1432 1433=item * 1434 1435The various large F<Changes*> files (which listed every change made 1436to perl over the last 18 years) have been removed, and replaced by a 1437small file, also called F<Changes>, which just explains how that same 1438information may be extracted from the git version control system. 1439 1440=item * 1441 1442F<Porting/patching.pod> has been deleted, as it mainly described 1443interacting with the old Perforce-based repository, which is now obsolete. 1444Information still relevant has been moved to L<perlrepository>. 1445 1446=item * 1447 1448The syntax C<unless (EXPR) BLOCK else BLOCK> is now documented as valid, 1449as is the syntax C<unless (EXPR) BLOCK elsif (EXPR) BLOCK ... else 1450BLOCK>, although actually using the latter may not be the best idea for 1451the readability of your source code. 1452 1453=item * 1454 1455Documented -X overloading. 1456 1457=item * 1458 1459Documented that C<when()> treats specially most of the filetest operators 1460 1461=item * 1462 1463Documented C<when> as a syntax modifier. 1464 1465=item * 1466 1467Eliminated "Old Perl threads tutorial", which described 5005 threads. 1468 1469F<pod/perlthrtut.pod> is the same material reworked for ithreads. 1470 1471=item * 1472 1473Correct previous documentation: v-strings are not deprecated 1474 1475With version objects, we need them to use MODULE VERSION syntax. This 1476patch removes the deprecation notice. 1477 1478=item * 1479 1480Security contact information is now part of L<perlsec>. 1481 1482=item * 1483 1484A significant fraction of the core documentation has been updated to 1485clarify the behavior of Perl's Unicode handling. 1486 1487Much of the remaining core documentation has been reviewed and edited 1488for clarity, consistent use of language, and to fix the spelling of Tom 1489Christiansen's name. 1490 1491=item * 1492 1493The Pod specification (L<perlpodspec>) has been updated to bring the 1494specification in line with modern usage already supported by most Pod 1495systems. A parameter string may now follow the format name in a 1496"begin/end" region. Links to URIs with a text description are now 1497allowed. The usage of C<LE<lt>"section"E<gt>> has been marked as 1498deprecated. 1499 1500=item * 1501 1502L<if.pm|if> has been documented in L<perlfunc/use> as a means to get 1503conditional loading of modules despite the implicit BEGIN block around 1504C<use>. 1505 1506=item * 1507 1508The documentation for C<$1> in perlvar.pod has been clarified. 1509 1510=item * 1511 1512C<\N{U+I<code point>}> is now documented. 1513 1514=back 1515 1516=head1 Selected Performance Enhancements 1517 1518=over 4 1519 1520=item * 1521 1522A new internal cache means that C<isa()> will often be faster. 1523 1524=item * 1525 1526The implementation of C<C3> Method Resolution Order has been 1527optimised - linearisation for classes with single inheritance is 40% 1528faster. Performance for multiple inheritance is unchanged. 1529 1530=item * 1531 1532Under C<use locale>, the locale-relevant information is now cached on 1533read-only values, such as the list returned by C<keys %hash>. This makes 1534operations such as C<sort keys %hash> in the scope of C<use locale> 1535much faster. 1536 1537=item * 1538 1539Empty C<DESTROY> methods are no longer called. 1540 1541=item * 1542 1543C<Perl_sv_utf8_upgrade()> is now faster. 1544 1545=item * 1546 1547C<keys> on empty hash is now faster. 1548 1549=item * 1550 1551C<if (%foo)> has been optimized to be faster than C<if (keys %foo)>. 1552 1553=item * 1554 1555The string repetition operator (C<$str x $num>) is now several times 1556faster when C<$str> has length one or C<$num> is large. 1557 1558=item * 1559 1560Reversing an array to itself (as in C<@a = reverse @a>) in void context 1561now happens in-place and is several orders of magnitude faster than 1562it used to be. It will also preserve non-existent elements whenever 1563possible, i.e. for non magical arrays or tied arrays with C<EXISTS> 1564and C<DELETE> methods. 1565 1566=back 1567 1568=head1 Installation and Configuration Improvements 1569 1570=over 4 1571 1572=item * 1573 1574L<perlapi>, L<perlintern>, L<perlmodlib> and L<perltoc> are now all 1575generated at build time, rather than being shipped as part of the release. 1576 1577=item * 1578 1579If C<vendorlib> and C<vendorarch> are the same, then they are only added 1580to C<@INC> once. 1581 1582=item * 1583 1584C<$Config{usedevel}> and the C-level C<PERL_USE_DEVEL> are now defined if 1585perl is built with C<-Dusedevel>. 1586 1587=item * 1588 1589F<Configure> will enable use of C<-fstack-protector>, to provide protection 1590against stack-smashing attacks, if the compiler supports it. 1591 1592=item * 1593 1594F<Configure> will now determine the correct prototypes for re-entrant 1595functions and for C<gconvert> if you are using a C++ compiler rather 1596than a C compiler. 1597 1598=item * 1599 1600On Unix, if you build from a tree containing a git repository, the 1601configuration process will note the commit hash you have checked out, for 1602display in the output of C<perl -v> and C<perl -V>. Unpushed local commits 1603are automatically added to the list of local patches displayed by 1604C<perl -V>. 1605 1606=item * 1607 1608Perl now supports SystemTap's C<dtrace> compatibility layer and an 1609issue with linking C<miniperl> has been fixed in the process. 1610 1611=item * 1612 1613perldoc now uses C<less -R> instead of C<less> for improved behaviour 1614in the face of C<groff>'s new usage of ANSI escape codes. 1615 1616=item * 1617 1618 1619C<perl -V> now reports use of the compile-time options C<USE_PERL_ATOF> and 1620C<USE_ATTRIBUTES_FOR_PERLIO>. 1621 1622=item * 1623 1624As part of the flattening of F<ext>, all extensions on all platforms are 1625built by F<make_ext.pl>. This replaces the Unix-specific 1626F<ext/util/make_ext>, VMS-specific F<make_ext.com> and Win32-specific 1627F<win32/buildext.pl>. 1628 1629=back 1630 1631=head1 Internal Changes 1632 1633Each release of Perl sees numerous internal changes which shouldn't 1634affect day to day usage but may still be notable for developers working 1635with Perl's source code. 1636 1637=over 1638 1639=item * 1640 1641The J.R.R. Tolkien quotes at the head of C source file have been checked 1642and proper citations added, thanks to a patch from Tom Christiansen. 1643 1644=item * 1645 1646The internal structure of the dual-life modules traditionally found in 1647the F<lib/> and F<ext/> directories in the perl source has changed 1648significantly. Where possible, dual-lifed modules have been extracted 1649from F<lib/> and F<ext/>. 1650 1651Dual-lifed modules maintained by Perl's developers as part of the Perl 1652core now live in F<dist/>. Dual-lifed modules maintained primarily on 1653CPAN now live in F<cpan/>. When reporting a bug in a module located 1654under F<cpan/>, please send your bug report directly to the module's 1655bug tracker or author, rather than Perl's bug tracker. 1656 1657=item * 1658 1659C<\N{...}> now compiles better, always forces UTF-8 internal representation 1660 1661Perl's developers have fixed several problems with the recognition of 1662C<\N{...}> constructs. As part of this, perl will store any scalar 1663or regex containing C<\N{I<name>}> or C<\N{U+I<code point>}> in its 1664definition in UTF-8 format. (This was true previously for all occurrences 1665of C<\N{I<name>}> that did not use a custom translator, but now it's 1666always true.) 1667 1668=item * 1669 1670Perl_magic_setmglob now knows about globs, fixing RT #71254. 1671 1672=item * 1673 1674C<SVt_RV> no longer exists. RVs are now stored in IVs. 1675 1676=item * 1677 1678C<Perl_vcroak()> now accepts a null first argument. In addition, a full 1679audit was made of the "not NULL" compiler annotations, and those for 1680several other internal functions were corrected. 1681 1682=item * 1683 1684New macros C<dSAVEDERRNO>, C<dSAVE_ERRNO>, C<SAVE_ERRNO>, C<RESTORE_ERRNO> 1685have been added to formalise the temporary saving of the C<errno> 1686variable. 1687 1688=item * 1689 1690The function C<Perl_sv_insert_flags> has been added to augment 1691C<Perl_sv_insert>. 1692 1693=item * 1694 1695The function C<Perl_newSV_type(type)> has been added, equivalent to 1696C<Perl_newSV()> followed by C<Perl_sv_upgrade(type)>. 1697 1698=item * 1699 1700The function C<Perl_newSVpvn_flags()> has been added, equivalent to 1701C<Perl_newSVpvn()> and then performing the action relevant to the flag. 1702 1703Two flag bits are currently supported. 1704 1705=over 4 1706 1707=item * 1708 1709C<SVf_UTF8> will call C<SvUTF8_on()> for you. (Note that this does 1710not convert a sequence of ISO 8859-1 characters to UTF-8). A wrapper, 1711C<newSVpvn_utf8()> is available for this. 1712 1713=item * 1714 1715C<SVs_TEMP> now calls C<Perl_sv_2mortal()> on the new SV. 1716 1717=back 1718 1719There is also a wrapper that takes constant strings, C<newSVpvs_flags()>. 1720 1721=item * 1722 1723The function C<Perl_croak_xs_usage> has been added as a wrapper to 1724C<Perl_croak>. 1725 1726=item * 1727 1728Perl now exports the functions C<PerlIO_find_layer> and C<PerlIO_list_alloc>. 1729 1730=item * 1731 1732C<PL_na> has been exterminated from the core code, replaced by local 1733STRLEN temporaries, or C<*_nolen()> calls. Either approach is faster than 1734C<PL_na>, which is a pointer dereference into the interpreter structure 1735under ithreads, and a global variable otherwise. 1736 1737=item * 1738 1739C<Perl_mg_free()> used to leave freed memory accessible via C<SvMAGIC()> 1740on the scalar. It now updates the linked list to remove each piece of 1741magic as it is freed. 1742 1743=item * 1744 1745Under ithreads, the regex in C<PL_reg_curpm> is now reference 1746counted. This eliminates a lot of hackish workarounds to cope with it 1747not being reference counted. 1748 1749=item * 1750 1751C<Perl_mg_magical()> would sometimes incorrectly turn on C<SvRMAGICAL()>. 1752This has been fixed. 1753 1754=item * 1755 1756The I<public> IV and NV flags are now not set if the string value has 1757trailing "garbage". This behaviour is consistent with not setting the 1758public IV or NV flags if the value is out of range for the type. 1759 1760=item * 1761 1762Uses of C<Nullav>, C<Nullcv>, C<Nullhv>, C<Nullop>, C<Nullsv> etc have 1763been replaced by C<NULL> in the core code, and non-dual-life modules, 1764as C<NULL> is clearer to those unfamiliar with the core code. 1765 1766=item * 1767 1768A macro C<MUTABLE_PTR(p)> has been added, which on (non-pedantic) gcc will 1769not cast away C<const>, returning a C<void *>. Macros C<MUTABLE_SV(av)>, 1770C<MUTABLE_SV(cv)> etc build on this, casting to C<AV *> etc without 1771casting away C<const>. This allows proper compile-time auditing of 1772C<const> correctness in the core, and helped picked up some errors 1773(now fixed). 1774 1775=item * 1776 1777Macros C<mPUSHs()> and C<mXPUSHs()> have been added, for pushing SVs on the 1778stack and mortalizing them. 1779 1780=item * 1781 1782Use of the private structure C<mro_meta> has changed slightly. Nothing 1783outside the core should be accessing this directly anyway. 1784 1785=item * 1786 1787A new tool, F<Porting/expand-macro.pl> has been added, that allows you 1788to view how a C preprocessor macro would be expanded when compiled. 1789This is handy when trying to decode the macro hell that is the perl 1790guts. 1791 1792=back 1793 1794=head1 Testing 1795 1796=head2 Testing improvements 1797 1798=over 4 1799 1800=item Parallel tests 1801 1802The core distribution can now run its regression tests in parallel on 1803Unix-like platforms. Instead of running C<make test>, set C<TEST_JOBS> in 1804your environment to the number of tests to run in parallel, and run 1805C<make test_harness>. On a Bourne-like shell, this can be done as 1806 1807 TEST_JOBS=3 make test_harness # Run 3 tests in parallel 1808 1809An environment variable is used, rather than parallel make itself, because 1810L<TAP::Harness> needs to be able to schedule individual non-conflicting test 1811scripts itself, and there is no standard interface to C<make> utilities to 1812interact with their job schedulers. 1813 1814Note that currently some test scripts may fail when run in parallel (most 1815notably C<ext/IO/t/io_dir.t>). If necessary run just the failing scripts 1816again sequentially and see if the failures go away. 1817 1818=item Test harness flexibility 1819 1820It's now possible to override C<PERL5OPT> and friends in F<t/TEST> 1821 1822=item Test watchdog 1823 1824Several tests that have the potential to hang forever if they fail now 1825incorporate a "watchdog" functionality that will kill them after a timeout, 1826which helps ensure that C<make test> and C<make test_harness> run to 1827completion automatically. 1828 1829 1830=back 1831 1832=head2 New Tests 1833 1834Perl's developers have added a number of new tests to the core. 1835In addition to the items listed below, many modules updated from CPAN 1836incorporate new tests. 1837 1838=over 4 1839 1840=item * 1841 1842Significant cleanups to core tests to ensure that language and 1843interpreter features are not used before they're tested. 1844 1845=item * 1846 1847C<make test_porting> now runs a number of important pre-commit checks 1848which might be of use to anyone working on the Perl core. 1849 1850=item * 1851 1852F<t/porting/podcheck.t> automatically checks the well-formedness of 1853POD found in all .pl, .pm and .pod files in the F<MANIFEST>, other than in 1854dual-lifed modules which are primarily maintained outside the Perl core. 1855 1856=item * 1857 1858F<t/porting/manifest.t> now tests that all files listed in MANIFEST 1859are present. 1860 1861=item * 1862 1863F<t/op/while_readdir.t> tests that a bare readdir in while loop sets $_. 1864 1865=item * 1866 1867F<t/comp/retainedlines.t> checks that the debugger can retain source 1868lines from C<eval>. 1869 1870=item * 1871 1872F<t/io/perlio_fail.t> checks that bad layers fail. 1873 1874=item * 1875 1876F<t/io/perlio_leaks.t> checks that PerlIO layers are not leaking. 1877 1878=item * 1879 1880F<t/io/perlio_open.t> checks that certain special forms of open work. 1881 1882=item * 1883 1884F<t/io/perlio.t> includes general PerlIO tests. 1885 1886=item * 1887 1888F<t/io/pvbm.t> checks that there is no unexpected interaction between 1889the internal types C<PVBM> and C<PVGV>. 1890 1891=item * 1892 1893F<t/mro/package_aliases.t> checks that mro works properly in the presence 1894of aliased packages. 1895 1896=item * 1897 1898F<t/op/dbm.t> tests C<dbmopen> and C<dbmclose>. 1899 1900=item * 1901 1902F<t/op/index_thr.t> tests the interaction of C<index> and threads. 1903 1904=item * 1905 1906F<t/op/pat_thr.t> tests the interaction of esoteric patterns and threads. 1907 1908=item * 1909 1910F<t/op/qr_gc.t> tests that C<qr> doesn't leak. 1911 1912=item * 1913 1914F<t/op/reg_email_thr.t> tests the interaction of regex recursion and threads. 1915 1916=item * 1917 1918F<t/op/regexp_qr_embed_thr.t> tests the interaction of patterns with 1919embedded C<qr//> and threads. 1920 1921=item * 1922 1923F<t/op/regexp_unicode_prop.t> tests Unicode properties in regular 1924expressions. 1925 1926=item * 1927 1928F<t/op/regexp_unicode_prop_thr.t> tests the interaction of Unicode 1929properties and threads. 1930 1931=item * 1932 1933F<t/op/reg_nc_tie.t> tests the tied methods of C<Tie::Hash::NamedCapture>. 1934 1935=item * 1936 1937F<t/op/reg_posixcc.t> checks that POSIX character classes behave 1938consistently. 1939 1940=item * 1941 1942F<t/op/re.t> checks that exportable C<re> functions in F<universal.c> work. 1943 1944=item * 1945 1946F<t/op/setpgrpstack.t> checks that C<setpgrp> works. 1947 1948=item * 1949 1950F<t/op/substr_thr.t> tests the interaction of C<substr> and threads. 1951 1952=item * 1953 1954F<t/op/upgrade.t> checks that upgrading and assigning scalars works. 1955 1956=item * 1957 1958F<t/uni/lex_utf8.t> checks that Unicode in the lexer works. 1959 1960=item * 1961 1962F<t/uni/tie.t> checks that Unicode and C<tie> work. 1963 1964=item * 1965 1966F<t/comp/final_line_num.t> tests whether line numbers are correct at EOF 1967 1968=item * 1969 1970F<t/comp/form_scope.t> tests format scoping. 1971 1972=item * 1973 1974F<t/comp/line_debug.t> tests whether C<< @{"_<$file"} >> works. 1975 1976=item * 1977 1978F<t/op/filetest_t.t> tests if -t file test works. 1979 1980=item * 1981 1982F<t/op/qr.t> tests C<qr>. 1983 1984=item * 1985 1986F<t/op/utf8cache.t> tests malfunctions of the utf8 cache. 1987 1988=item * 1989 1990F<t/re/uniprops.t> test unicodes C<\p{}> regex constructs. 1991 1992=item * 1993 1994F<t/op/filehandle.t> tests some suitably portable filetest operators 1995to check that they work as expected, particularly in the light of some 1996internal changes made in how filehandles are blessed. 1997 1998=item * 1999 2000F<t/op/time_loop.t> tests that unix times greater than C<2**63>, which 2001can now be handed to C<gmtime> and C<localtime>, do not cause an internal 2002overflow or an excessively long loop. 2003 2004=back 2005 2006 2007=head1 New or Changed Diagnostics 2008 2009=head2 New Diagnostics 2010 2011=over 2012 2013=item * 2014 2015SV allocation tracing has been added to the diagnostics enabled by C<-Dm>. 2016The tracing can alternatively output via the C<PERL_MEM_LOG> mechanism, if 2017that was enabled when the F<perl> binary was compiled. 2018 2019=item * 2020 2021Smartmatch resolution tracing has been added as a new diagnostic. Use 2022C<-DM> to enable it. 2023 2024=item * 2025 2026A new debugging flag C<-DB> now dumps subroutine definitions, leaving 2027C<-Dx> for its original purpose of dumping syntax trees. 2028 2029=item * 2030 2031Perl 5.12 provides a number of new diagnostic messages to help you write 2032better code. See L<perldiag> for details of these new messages. 2033 2034=over 4 2035 2036=item * 2037 2038C<Bad plugin affecting keyword '%s'> 2039 2040=item * 2041 2042C<gmtime(%.0f) too large> 2043 2044=item * 2045 2046C<Lexing code attempted to stuff non-Latin-1 character into Latin-1 input> 2047 2048=item * 2049 2050C<Lexing code internal error (%s)> 2051 2052=item * 2053 2054C<localtime(%.0f) too large> 2055 2056=item * 2057 2058C<Overloaded dereference did not return a reference> 2059 2060=item * 2061 2062C<Overloaded qr did not return a REGEXP> 2063 2064=item * 2065 2066C<Perl_pmflag() is deprecated, and will be removed from the XS API> 2067 2068=item * 2069 2070C<lvalue attribute ignored after the subroutine has been defined> 2071 2072This new warning is issued when one attempts to mark a subroutine as 2073lvalue after it has been defined. 2074 2075=item * 2076 2077Perl now warns you if C<++> or C<--> are unable to change the value 2078because it's beyond the limit of representation. 2079 2080This uses a new warnings category: "imprecision". 2081 2082=item * 2083 2084C<lc>, C<uc>, C<lcfirst>, and C<ucfirst> warn when passed undef. 2085 2086=item * 2087 2088C<Show constant in "Useless use of a constant in void context"> 2089 2090=item * 2091 2092C<Prototype after '%s'> 2093 2094=item * 2095 2096C<panic: sv_chop %s> 2097 2098This new fatal error occurs when the C routine C<Perl_sv_chop()> was 2099passed a position that is not within the scalar's string buffer. This 2100could be caused by buggy XS code, and at this point recovery is not 2101possible. 2102 2103=item * 2104 2105The fatal error C<Malformed UTF-8 returned by \N> is now produced if the 2106C<charnames> handler returns malformed UTF-8. 2107 2108=item * 2109 2110If an unresolved named character or sequence was encountered when 2111compiling a regex pattern then the fatal error C<\N{NAME} must be resolved 2112by the lexer> is now produced. This can happen, for example, when using a 2113single-quotish context like C<$re = '\N{SPACE}'; /$re/;>. See L<perldiag> 2114for more examples of how the lexer can get bypassed. 2115 2116=item * 2117 2118C<Invalid hexadecimal number in \N{U+...}> is a new fatal error 2119triggered when the character constant represented by C<...> is not a 2120valid hexadecimal number. 2121 2122=item * 2123 2124The new meaning of C<\N> as C<[^\n]> is not valid in a bracketed character 2125class, just like C<.> in a character class loses its special meaning, 2126and will cause the fatal error C<\N in a character class must be a named 2127character: \N{...}>. 2128 2129=item * 2130 2131The rules on what is legal for the C<...> in C<\N{...}> have been 2132tightened up so that unless the C<...> begins with an alphabetic 2133character and continues with a combination of alphanumerics, dashes, 2134spaces, parentheses or colons then the warning C<Deprecated character(s) 2135in \N{...} starting at '%s'> is now issued. 2136 2137=item * 2138 2139The warning C<Using just the first characters returned by \N{}> will 2140be issued if the C<charnames> handler returns a sequence of characters 2141which exceeds the limit of the number of characters that can be used. The 2142message will indicate which characters were used and which were discarded. 2143 2144=back 2145 2146=back 2147 2148=head2 Changed Diagnostics 2149 2150A number of existing diagnostic messages have been improved or corrected: 2151 2152=over 2153 2154=item * 2155 2156A new warning category C<illegalproto> allows finer-grained control of 2157warnings around function prototypes. 2158 2159The two warnings: 2160 2161=over 2162 2163=item C<Illegal character in prototype for %s : %s> 2164 2165=item C<Prototype after '%c' for %s : %s> 2166 2167=back 2168 2169have been moved from the C<syntax> top-level warnings category into a new 2170first-level category, C<illegalproto>. These two warnings are currently 2171the only ones emitted during parsing of an invalid/illegal prototype, 2172so one can now use 2173 2174 no warnings 'illegalproto'; 2175 2176to suppress only those, but not other syntax-related warnings. Warnings 2177where prototypes are changed, ignored, or not met are still in the 2178C<prototype> category as before. 2179 2180=item * 2181 2182C<Deep recursion on subroutine "%s"> 2183 2184It is now possible to change the depth threshold for this warning from the 2185default of 100, by recompiling the F<perl> binary, setting the C 2186pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value. 2187 2188=item * 2189 2190C<Illegal character in prototype> warning is now more precise 2191when reporting illegal characters after _ 2192 2193=item * 2194 2195mro merging error messages are now very similar to those produced by 2196L<Algorithm::C3>. 2197 2198=item * 2199 2200Amelioration of the error message "Unrecognized character %s in column %d" 2201 2202Changes the error message to "Unrecognized character %s; marked by E<lt>-- 2203HERE after %sE<lt>-- HERE near column %d". This should make it a little 2204simpler to spot and correct the suspicious character. 2205 2206=item * 2207 2208Perl now explicitly points to C<$.> when it causes an uninitialized 2209warning for ranges in scalar context. 2210 2211=item * 2212 2213C<split> now warns when called in void context. 2214 2215=item * 2216 2217C<printf>-style functions called with too few arguments will now issue the 2218warning C<"Missing argument in %s"> [perl #71000] 2219 2220=item * 2221 2222Perl now properly returns a syntax error instead of segfaulting 2223if C<each>, C<keys>, or C<values> is used without an argument. 2224 2225=item * 2226 2227C<tell()> now fails properly if called without an argument and when no 2228previous file was read. 2229 2230C<tell()> now returns C<-1>, and sets errno to C<EBADF>, thus restoring 2231the 5.8.x behaviour. 2232 2233=item * 2234 2235C<overload> no longer implicitly unsets fallback on repeated 'use 2236overload' lines. 2237 2238=item * 2239 2240POSIX::strftime() can now handle Unicode characters in the format string. 2241 2242=item * 2243 2244The C<syntax> category was removed from 5 warnings that should only be in 2245C<deprecated>. 2246 2247=item * 2248 2249Three fatal C<pack>/C<unpack> error messages have been normalized to 2250C<panic: %s> 2251 2252=item * 2253 2254C<Unicode character is illegal> has been rephrased to be more accurate 2255 2256It now reads C<Unicode non-character is illegal in interchange> and the 2257perldiag documentation has been expanded a bit. 2258 2259=item * 2260 2261Currently, all but the first of the several characters that the 2262C<charnames> handler may return are discarded when used in a regular 2263expression pattern bracketed character class. If this happens then the 2264warning C<Using just the first character returned by \N{} in character 2265class> will be issued. 2266 2267=item * 2268 2269The warning C<Missing right brace on \N{} or unescaped left brace after 2270\N. Assuming the latter> will be issued if Perl encounters a C<\N{> 2271but doesn't find a matching C<}>. In this case Perl doesn't know if it 2272was mistakenly omitted, or if "match non-newline" followed by "match 2273a C<{>" was desired. It assumes the latter because that is actually a 2274valid interpretation as written, unlike the other case. If you meant 2275the former, you need to add the matching right brace. If you did mean 2276the latter, you can silence this warning by writing instead C<\N\{>. 2277 2278=item * 2279 2280C<gmtime> and C<localtime> called with numbers smaller than they can 2281reliably handle will now issue the warnings C<gmtime(%.0f) too small> 2282and C<localtime(%.0f) too small>. 2283 2284=back 2285 2286The following diagnostic messages have been removed: 2287 2288=over 4 2289 2290=item * 2291 2292C<Runaway format> 2293 2294=item * 2295 2296C<Can't locate package %s for the parents of %s> 2297 2298In general this warning it only got produced in 2299conjunction with other warnings, and removing it allowed an ISA lookup 2300optimisation to be added. 2301 2302=item * 2303 2304C<v-string in use/require is non-portable> 2305 2306=back 2307 2308=head1 Utility Changes 2309 2310=over 4 2311 2312=item * 2313 2314F<h2ph> now looks in C<include-fixed> too, which is a recent addition 2315to gcc's search path. 2316 2317=item * 2318 2319F<h2xs> no longer incorrectly treats enum values like macros. 2320It also now handles C++ style comments (C<//>) properly in enums. 2321 2322=item * 2323 2324F<perl5db.pl> now supports C<LVALUE> subroutines. Additionally, the 2325debugger now correctly handles proxy constant subroutines, and 2326subroutine stubs. 2327 2328=item * 2329 2330F<perlbug> now uses C<%Module::CoreList::bug_tracker> to print out 2331upstream bug tracker URLs. If a user identifies a particular module 2332as the topic of their bug report and we're able to divine the URL for 2333its upstream bug tracker, perlbug now provide a message to the user 2334explaining that the core copies the CPAN version directly, and provide 2335the URL for reporting the bug directly to the upstream author. 2336 2337F<perlbug> no longer reports "Message sent" when it hasn't actually sent 2338the message 2339 2340=item * 2341 2342F<perlthanks> is a new utility for sending non-bug-reports to the 2343authors and maintainers of Perl. Getting nothing but bug reports can 2344become a bit demoralising. If Perl 5.12 works well for you, please try 2345out F<perlthanks>. It will make the developers smile. 2346 2347=item * 2348 2349Perl's developers have fixed bugs in F<a2p> having to do with the 2350C<match()> operator in list context. Additionally, F<a2p> no longer 2351generates code that uses the C<$[> variable. 2352 2353=back 2354 2355=head1 Selected Bug Fixes 2356 2357=over 4 2358 2359=item * 2360 2361U+0FFFF is now a legal character in regular expressions. 2362 2363=item * 2364 2365pp_qr now always returns a new regexp SV. Resolves RT #69852. 2366 2367Instead of returning a(nother) reference to the (pre-compiled) regexp 2368in the optree, use reg_temp_copy() to create a copy of it, and return a 2369reference to that. This resolves issues about Regexp::DESTROY not being 2370called in a timely fashion (the original bug tracked by RT #69852), as 2371well as bugs related to blessing regexps, and of assigning to regexps, 2372as described in correspondence added to the ticket. 2373 2374It transpires that we also need to undo the SvPVX() sharing when ithreads 2375cloning a Regexp SV, because mother_re is set to NULL, instead of a 2376cloned copy of the mother_re. This change might fix bugs with regexps 2377and threads in certain other situations, but as yet neither tests nor 2378bug reports have indicated any problems, so it might not actually be an 2379edge case that it's possible to reach. 2380 2381=item * 2382 2383Several compilation errors and segfaults when perl was built with C<-Dmad> 2384were fixed. 2385 2386=item * 2387 2388Fixes for lexer API changes in 5.11.2 which broke NYTProf's savesrc option. 2389 2390=item * 2391 2392C<-t> should only return TRUE for file handles connected to a TTY 2393 2394The Microsoft C version of C<isatty()> returns TRUE for all character mode 2395devices, including the F</dev/null>-style "nul" device and printers like 2396"lpt1". 2397 2398=item * 2399 2400Fixed a regression caused by commit fafafbaf which caused a panic during 2401parameter passing [perl #70171] 2402 2403=item * 2404 2405On systems which in-place edits without backup files, -i'*' now works as 2406the documentation says it does [perl #70802] 2407 2408=item * 2409 2410Saving and restoring magic flags no longer loses readonly flag. 2411 2412=item * 2413 2414The malformed syntax C<grep EXPR LIST> (note the missing comma) no longer 2415causes abrupt and total failure. 2416 2417=item * 2418 2419Regular expressions compiled with C<qr{}> literals properly set C<$'> when 2420matching again. 2421 2422=item * 2423 2424Using named subroutines with C<sort> should no longer lead to bus errors 2425[perl #71076] 2426 2427=item * 2428 2429Numerous bugfixes catch small issues caused by the recently-added Lexer API. 2430 2431=item * 2432 2433Smart match against C<@_> sometimes gave false negatives. [perl #71078] 2434 2435=item * 2436 2437C<$@> may now be assigned a read-only value (without error or busting 2438the stack). 2439 2440=item * 2441 2442C<sort> called recursively from within an active comparison subroutine no 2443longer causes a bus error if run multiple times. [perl #71076] 2444 2445=item * 2446 2447Tie::Hash::NamedCapture::* will not abort if passed bad input (RT #71828) 2448 2449=item * 2450 2451@_ and $_ no longer leak under threads (RT #34342 and #41138, also 2452#70602, #70974) 2453 2454=item * 2455 2456C<-I> on shebang line now adds directories in front of @INC 2457as documented, and as does C<-I> when specified on the command-line. 2458 2459=item * 2460 2461C<kill> is now fatal when called on non-numeric process identifiers. 2462Previously, an C<undef> process identifier would be interpreted as a 2463request to kill process 0, which would terminate the current process 2464group on POSIX systems. Since process identifiers are always integers, 2465killing a non-numeric process is now fatal. 2466 2467=item * 2468 24695.10.0 inadvertently disabled an optimisation, which caused a measurable 2470performance drop in list assignment, such as is often used to assign 2471function parameters from C<@_>. The optimisation has been re-instated, and 2472the performance regression fixed. (This fix is also present in 5.10.1) 2473 2474=item * 2475 2476Fixed memory leak on C<while (1) { map 1, 1 }> [RT #53038]. 2477 2478=item * 2479 2480Some potential coredumps in PerlIO fixed [RT #57322,54828]. 2481 2482=item * 2483 2484The debugger now works with lvalue subroutines. 2485 2486=item * 2487 2488The debugger's C<m> command was broken on modules that defined constants 2489[RT #61222]. 2490 2491=item * 2492 2493C<crypt> and string complement could return tainted values for untainted 2494arguments [RT #59998]. 2495 2496=item * 2497 2498The C<-i>I<.suffix> command-line switch now recreates the file using 2499restricted permissions, before changing its mode to match the original 2500file. This eliminates a potential race condition [RT #60904]. 2501 2502=item * 2503 2504On some Unix systems, the value in C<$?> would not have the top bit set 2505(C<$? & 128>) even if the child core dumped. 2506 2507=item * 2508 2509Under some circumstances, C<$^R> could incorrectly become undefined 2510[RT #57042]. 2511 2512=item * 2513 2514In the XS API, various hash functions, when passed a pre-computed hash where 2515the key is UTF-8, might result in an incorrect lookup. 2516 2517=item * 2518 2519XS code including F<XSUB.h> before F<perl.h> gave a compile-time error 2520[RT #57176]. 2521 2522=item * 2523 2524C<< $object-E<gt>isa('Foo') >> would report false if the package C<Foo> 2525didn't exist, even if the object's C<@ISA> contained C<Foo>. 2526 2527=item * 2528 2529Various bugs in the new-to 5.10.0 mro code, triggered by manipulating 2530C<@ISA>, have been found and fixed. 2531 2532=item * 2533 2534Bitwise operations on references could crash the interpreter, e.g. 2535C<$x=\$y; $x |= "foo"> [RT #54956]. 2536 2537=item * 2538 2539Patterns including alternation might be sensitive to the internal UTF-8 2540representation, e.g. 2541 2542 my $byte = chr(192); 2543 my $utf8 = chr(192); utf8::upgrade($utf8); 2544 $utf8 =~ /$byte|X}/i; # failed in 5.10.0 2545 2546=item * 2547 2548Within UTF8-encoded Perl source files (i.e. where C<use utf8> is in 2549effect), double-quoted literal strings could be corrupted where a C<\xNN>, 2550C<\0NNN> or C<\N{}> is followed by a literal character with ordinal value 2551greater than 255 [RT #59908]. 2552 2553=item * 2554 2555C<B::Deparse> failed to correctly deparse various constructs: 2556C<readpipe STRING> [RT #62428], C<CORE::require(STRING)> [RT #62488], 2557C<sub foo(_)> [RT #62484]. 2558 2559=item * 2560 2561Using C<setpgrp> with no arguments could corrupt the perl stack. 2562 2563=item * 2564 2565The block form of C<eval> is now specifically trappable by C<Safe> and 2566C<ops>. Previously it was erroneously treated like string C<eval>. 2567 2568=item * 2569 2570In 5.10.0, the two characters C<[~> were sometimes parsed as the smart 2571match operator (C<~~>) [RT #63854]. 2572 2573=item * 2574 2575In 5.10.0, the C<*> quantifier in patterns was sometimes treated as 2576C<{0,32767}> [RT #60034, #60464]. For example, this match would fail: 2577 2578 ("ab" x 32768) =~ /^(ab)*$/ 2579 2580=item * 2581 2582C<shmget> was limited to a 32 bit segment size on a 64 bit OS [RT #63924]. 2583 2584=item * 2585 2586Using C<next> or C<last> to exit a C<given> block no longer produces a 2587spurious warning like the following: 2588 2589 Exiting given via last at foo.pl line 123 2590 2591=item * 2592 2593Assigning a format to a glob could corrupt the format; e.g.: 2594 2595 *bar=*foo{FORMAT}; # foo format now bad 2596 2597=item * 2598 2599Attempting to coerce a typeglob to a string or number could cause an 2600assertion failure. The correct error message is now generated, 2601C<Can't coerce GLOB to I<$type>>. 2602 2603=item * 2604 2605Under C<use filetest 'access'>, C<-x> was using the wrong access 2606mode. This has been fixed [RT #49003]. 2607 2608=item * 2609 2610C<length> on a tied scalar that returned a Unicode value would not be 2611correct the first time. This has been fixed. 2612 2613=item * 2614 2615Using an array C<tie> inside in array C<tie> could SEGV. This has been 2616fixed. [RT #51636] 2617 2618=item * 2619 2620A race condition inside C<PerlIOStdio_close()> has been identified and 2621fixed. This used to cause various threading issues, including SEGVs. 2622 2623=item * 2624 2625In C<unpack>, the use of C<()> groups in scalar context was internally 2626placing a list on the interpreter's stack, which manifested in various 2627ways, including SEGVs. This is now fixed [RT #50256]. 2628 2629=item * 2630 2631Magic was called twice in C<substr>, C<\&$x>, C<tie $x, $m> and C<chop>. 2632These have all been fixed. 2633 2634=item * 2635 2636A 5.10.0 optimisation to clear the temporary stack within the implicit 2637loop of C<s///ge> has been reverted, as it turned out to be the cause of 2638obscure bugs in seemingly unrelated parts of the interpreter [commit 2639ef0d4e17921ee3de]. 2640 2641=item * 2642 2643The line numbers for warnings inside C<elsif> are now correct. 2644 2645=item * 2646 2647The C<..> operator now works correctly with ranges whose ends are at or 2648close to the values of the smallest and largest integers. 2649 2650=item * 2651 2652C<binmode STDIN, ':raw'> could lead to segmentation faults on some platforms. 2653This has been fixed [RT #54828]. 2654 2655=item * 2656 2657An off-by-one error meant that C<index $str, ...> was effectively being 2658executed as C<index "$str\0", ...>. This has been fixed [RT #53746]. 2659 2660=item * 2661 2662Various leaks associated with named captures in regexes have been fixed 2663[RT #57024]. 2664 2665=item * 2666 2667A weak reference to a hash would leak. This was affecting C<DBI> 2668[RT #56908]. 2669 2670=item * 2671 2672Using (?|) in a regex could cause a segfault [RT #59734]. 2673 2674=item * 2675 2676Use of a UTF-8 C<tr//> within a closure could cause a segfault [RT #61520]. 2677 2678=item * 2679 2680Calling C<Perl_sv_chop()> or otherwise upgrading an SV could result in an 2681unaligned 64-bit access on the SPARC architecture [RT #60574]. 2682 2683=item * 2684 2685In the 5.10.0 release, C<inc_version_list> would incorrectly list 2686C<5.10.*> after C<5.8.*>; this affected the C<@INC> search order 2687[RT #67628]. 2688 2689=item * 2690 2691In 5.10.0, C<pack "a*", $tainted_value> returned a non-tainted value 2692[RT #52552]. 2693 2694=item * 2695 2696In 5.10.0, C<printf> and C<sprintf> could produce the fatal error 2697C<panic: utf8_mg_pos_cache_update> when printing UTF-8 strings 2698[RT #62666]. 2699 2700=item * 2701 2702In the 5.10.0 release, a dynamically created C<AUTOLOAD> method might be 2703missed (method cache issue) [RT #60220,60232]. 2704 2705=item * 2706 2707In the 5.10.0 release, a combination of C<use feature> and C<//ee> could 2708cause a memory leak [RT #63110]. 2709 2710=item * 2711 2712C<-C> on the shebang (C<#!>) line is once more permitted if it is also 2713specified on the command line. C<-C> on the shebang line used to be a 2714silent no-op I<if> it was not also on the command line, so perl 5.10.0 2715disallowed it, which broke some scripts. Now perl checks whether it is 2716also on the command line and only dies if it is not [RT #67880]. 2717 2718=item * 2719 2720In 5.10.0, certain types of re-entrant regular expression could crash, 2721or cause the following assertion failure [RT #60508]: 2722 2723 Assertion rx->sublen >= (s - rx->subbeg) + i failed 2724 2725=item * 2726 2727Perl now includes previously missing files from the Unicode Character 2728Database. 2729 2730=item * 2731 2732Perl now honors C<TMPDIR> when opening an anonymous temporary file. 2733 2734=back 2735 2736 2737=head1 Platform Specific Changes 2738 2739Perl is incredibly portable. In general, if a platform has a C compiler, 2740someone has ported Perl to it (or will soon). We're happy to announce 2741that Perl 5.12 includes support for several new platforms. At the same 2742time, it's time to bid farewell to some (very) old friends. 2743 2744=head2 New Platforms 2745 2746=over 2747 2748=item Haiku 2749 2750Perl's developers have merged patches from Haiku's maintainers. Perl 2751should now build on Haiku. 2752 2753=item MirOS BSD 2754 2755Perl should now build on MirOS BSD. 2756 2757=back 2758 2759=head2 Discontinued Platforms 2760 2761=over 2762 2763=item Domain/OS 2764 2765=item MiNT 2766 2767=item Tenon MachTen 2768 2769=back 2770 2771=head2 Updated Platforms 2772 2773=over 4 2774 2775=item AIX 2776 2777=over 4 2778 2779=item * 2780 2781Removed F<libbsd> for AIX 5L and 6.1. Only C<flock()> was used from 2782F<libbsd>. 2783 2784=item * 2785 2786Removed F<libgdbm> for AIX 5L and 6.1 if F<libgdbm> < 1.8.3-5 is 2787installed. The F<libgdbm> is delivered as an optional package with the 2788AIX Toolbox. Unfortunately the versions below 1.8.3-5 are broken. 2789 2790=item * 2791 2792Hints changes mean that AIX 4.2 should work again. 2793 2794=back 2795 2796=item Cygwin 2797 2798=over 4 2799 2800=item * 2801 2802Perl now supports IPv6 on Cygwin 1.7 and newer. 2803 2804=item * 2805 2806On Cygwin we now strip the last number from the DLL. This has been the 2807behaviour in the cygwin.com build for years. The hints files have been 2808updated. 2809 2810=back 2811 2812=item Darwin (Mac OS X) 2813 2814=over 4 2815 2816=item * 2817 2818Skip testing the be_BY.CP1131 locale on Darwin 10 (Mac OS X 10.6), 2819as it's still buggy. 2820 2821=item * 2822 2823Correct infelicities in the regexp used to identify buggy locales 2824on Darwin 8 and 9 (Mac OS X 10.4 and 10.5, respectively). 2825 2826=back 2827 2828=item DragonFly BSD 2829 2830=over 4 2831 2832=item * 2833 2834Fix thread library selection [perl #69686] 2835 2836=back 2837 2838=item FreeBSD 2839 2840=over 4 2841 2842=item * 2843 2844The hints files now identify the correct threading libraries on FreeBSD 7 2845and later. 2846 2847=back 2848 2849=item Irix 2850 2851=over 4 2852 2853=item * 2854 2855We now work around a bizarre preprocessor bug in the Irix 6.5 compiler: 2856C<cc -E -> unfortunately goes into K&R mode, but C<cc -E file.c> doesn't. 2857 2858=back 2859 2860=item NetBSD 2861 2862=over 4 2863 2864=item * 2865 2866Hints now supports versions 5.*. 2867 2868=back 2869 2870=item OpenVMS 2871 2872=over 4 2873 2874=item * 2875 2876C<-UDEBUGGING> is now the default on VMS. 2877 2878Like it has been everywhere else for ages and ages. Also make command-line 2879selection of -UDEBUGGING and -DDEBUGGING work in configure.com; before 2880the only way to turn it off was by saying no in answer to the interactive 2881question. 2882 2883=item * 2884 2885The default pipe buffer size on VMS has been updated to 8192 on 64-bit 2886systems. 2887 2888=item * 2889 2890Reads from the in-memory temporary files of C<PerlIO::scalar> used to fail 2891if C<$/> was set to a numeric reference (to indicate record-style reads). 2892This is now fixed. 2893 2894=item * 2895 2896VMS now supports C<getgrgid>. 2897 2898=item * 2899 2900Many improvements and cleanups have been made to the VMS file name handling 2901and conversion code. 2902 2903=item * 2904 2905Enabling the C<PERL_VMS_POSIX_EXIT> logical name now encodes a POSIX exit 2906status in a VMS condition value for better interaction with GNV's bash 2907shell and other utilities that depend on POSIX exit values. See 2908L<perlvms/"$?"> for details. 2909 2910=item * 2911 2912C<File::Copy> now detects Unix compatibility mode on VMS. 2913 2914=back 2915 2916=item Stratus VOS 2917 2918=over 4 2919 2920=item * 2921 2922Various changes from Stratus have been merged in. 2923 2924=back 2925 2926=item Symbian 2927 2928=over 4 2929 2930=item * 2931 2932There is now support for Symbian S60 3.2 SDK and S60 5.0 SDK. 2933 2934=back 2935 2936=item Windows 2937 2938=over 4 2939 2940=item * 2941 2942Perl 5.12 supports Windows 2000 and later. The supporting code for 2943legacy versions of Windows is still included, but will be removed 2944during the next development cycle. 2945 2946=item * 2947 2948Initial support for building Perl with MinGW-w64 is now available. 2949 2950=item * 2951 2952F<perl.exe> now includes a manifest resource to specify the C<trustInfo> 2953settings for Windows Vista and later. Without this setting Windows 2954would treat F<perl.exe> as a legacy application and apply various 2955heuristics like redirecting access to protected file system areas 2956(like the "Program Files" folder) to the users "VirtualStore" 2957instead of generating a proper "permission denied" error. 2958 2959The manifest resource also requests the Microsoft Common-Controls 2960version 6.0 (themed controls introduced in Windows XP). Check out the 2961Win32::VisualStyles module on CPAN to switch back to old style 2962unthemed controls for legacy applications. 2963 2964=item * 2965 2966The C<-t> filetest operator now only returns true if the filehandle 2967is connected to a console window. In previous versions of Perl it 2968would return true for all character mode devices, including F<NUL> 2969and F<LPT1>. 2970 2971=item * 2972 2973The C<-p> filetest operator now works correctly, and the 2974Fcntl::S_IFIFO constant is defined when Perl is compiled with 2975Microsoft Visual C. In previous Perl versions C<-p> always 2976returned a false value, and the Fcntl::S_IFIFO constant 2977was not defined. 2978 2979This bug is specific to Microsoft Visual C and never affected 2980Perl binaries built with MinGW. 2981 2982=item * 2983 2984The socket error codes are now more widely supported: The POSIX 2985module will define the symbolic names, like POSIX::EWOULDBLOCK, 2986and stringification of socket error codes in $! works as well 2987now; 2988 2989 C:\>perl -MPOSIX -E "$!=POSIX::EWOULDBLOCK; say $!" 2990 A non-blocking socket operation could not be completed immediately. 2991 2992=item * 2993 2994flock() will now set sensible error codes in $!. Previous Perl versions 2995copied the value of $^E into $!, which caused much confusion. 2996 2997=item * 2998 2999select() now supports all empty C<fd_set>s more correctly. 3000 3001=item * 3002 3003C<'.\foo'> and C<'..\foo'> were treated differently than 3004C<'./foo'> and C<'../foo'> by C<do> and C<require> [RT #63492]. 3005 3006=item * 3007 3008Improved message window handling means that C<alarm> and C<kill> messages 3009will no longer be dropped under race conditions. 3010 3011=item * 3012 3013Various bits of Perl's build infrastructure are no longer converted to 3014win32 line endings at release time. If this hurts you, please report the 3015problem with the L<perlbug> program included with perl. 3016 3017=back 3018 3019=back 3020 3021 3022=head1 Known Problems 3023 3024This is a list of some significant unfixed bugs, which are regressions 3025from either 5.10.x or 5.8.x. 3026 3027=over 4 3028 3029=item * 3030 3031Some CPANPLUS tests may fail if there is a functioning file 3032F<../../cpanp-run-perl> outside your build directory. The failure 3033shouldn't imply there's a problem with the actual functional 3034software. The bug is already fixed in [RT #74188] and is scheduled for 3035inclusion in perl-v5.12.1. 3036 3037=item * 3038 3039C<List::Util::first> misbehaves in the presence of a lexical C<$_> 3040(typically introduced by C<my $_> or implicitly by C<given>). The variable 3041which gets set for each iteration is the package variable C<$_>, not the 3042lexical C<$_> [RT #67694]. 3043 3044A similar issue may occur in other modules that provide functions which 3045take a block as their first argument, like 3046 3047 foo { ... $_ ...} list 3048 3049=item * 3050 3051Some regexes may run much more slowly when run in a child thread compared 3052with the thread the pattern was compiled into [RT #55600]. 3053 3054=item * 3055 3056Things like C<"\N{LATIN SMALL LIGATURE FF}" =~ /\N{LATIN SMALL LETTER F}+/> 3057will appear to hang as they get into a very long running loop [RT #72998]. 3058 3059=item * 3060 3061Several porters have reported mysterious crashes when Perl's entire 3062test suite is run after a build on certain Windows 2000 systems. When 3063run by hand, the individual tests reportedly work fine. 3064 3065=back 3066 3067=head1 Errata 3068 3069=over 3070 3071=item * 3072 3073This one is actually a change introduced in 5.10.0, but it was missed 3074from that release's perldelta, so it is mentioned here instead. 3075 3076A bugfix related to the handling of the C</m> modifier and C<qr> resulted 3077in a change of behaviour between 5.8.x and 5.10.0: 3078 3079 # matches in 5.8.x, doesn't match in 5.10.0 3080 $re = qr/^bar/; "foo\nbar" =~ /$re/m; 3081 3082=back 3083 3084=head1 Acknowledgements 3085 3086Perl 5.12.0 represents approximately two years of development since 3087Perl 5.10.0 and contains over 750,000 lines of changes across over 30883,000 files from over 200 authors and committers. 3089 3090Perl continues to flourish into its third decade thanks to a vibrant 3091community of users and developers. The following people are known to 3092have contributed the improvements that became Perl 5.12.0: 3093 3094Aaron Crane, Abe Timmerman, Abhijit Menon-Sen, Abigail, Adam Russell, 3095Adriano Ferreira, Ævar Arnfjörð Bjarmason, Alan Grover, Alexandr 3096Ciornii, Alex Davies, Alex Vandiver, Andreas Koenig, Andrew Rodland, 3097andrew@sundale.net, Andy Armstrong, Andy Dougherty, Jose AUGUSTE-ETIENNE, 3098Benjamin Smith, Ben Morrow, bharanee rathna, Bo Borgerson, Bo Lindbergh, 3099Brad Gilbert, Bram, Brendan O'Dea, brian d foy, Charles Bailey, 3100Chip Salzenberg, Chris 'BinGOs' Williams, Christoph Lamprecht, Chris 3101Williams, chromatic, Claes Jakobsson, Craig A. Berry, Dan Dascalescu, 3102Daniel Frederick Crisman, Daniel M. Quinlan, Dan Jacobson, Dan Kogai, 3103Dave Mitchell, Dave Rolsky, David Cantrell, David Dick, David Golden, 3104David Mitchell, David M. Syzdek, David Nicol, David Wheeler, Dennis 3105Kaarsemaker, Dintelmann, Peter, Dominic Dunlop, Dr.Ruud, Duke Leto, 3106Enrico Sorcinelli, Eric Brine, Father Chrysostomos, Florian Ragwitz, 3107Frank Wiegand, Gabor Szabo, Gene Sullivan, Geoffrey T. Dairiki, George 3108Greer, Gerard Goossen, Gisle Aas, Goro Fuji, Graham Barr, Green, Paul, 3109Hans Dieter Pearcey, Harmen, H. Merijn Brand, Hugo van der Sanden, 3110Ian Goodacre, Igor Sutton, Ingo Weinhold, James Bence, James Mastros, 3111Jan Dubois, Jari Aalto, Jarkko Hietaniemi, Jay Hannah, Jerry Hedden, 3112Jesse Vincent, Jim Cromie, Jody Belka, John E. Malmberg, John Malmberg, 3113John Peacock, John Peacock via RT, John P. Linderman, John Wright, 3114Josh ben Jore, Jos I. Boumans, Karl Williamson, Kenichi Ishigaki, Ken 3115Williams, Kevin Brintnall, Kevin Ryde, Kurt Starsinic, Leon Brocard, 3116Lubomir Rintel, Luke Ross, Marcel Grünauer, Marcus Holland-Moritz, Mark 3117Jason Dominus, Marko Asplund, Martin Hasch, Mashrab Kuvatov, Matt Kraai, 3118Matt S Trout, Max Maischein, Michael Breen, Michael Cartmell, Michael 3119G Schwern, Michael Witten, Mike Giroux, Milosz Tanski, Moritz Lenz, 3120Nicholas Clark, Nick Cleaton, Niko Tyni, Offer Kaye, Osvaldo Villalon, 3121Paul Fenwick, Paul Gaborit, Paul Green, Paul Johnson, Paul Marquess, 3122Philip Hazel, Philippe Bruhat, Rafael Garcia-Suarez, Rainer Tammer, 3123Rajesh Mandalemula, Reini Urban, Renée Bäcker, Ricardo Signes, 3124Ricardo SIGNES, Richard Foley, Rich Rauenzahn, Rick Delaney, Risto 3125Kankkunen, Robert May, Roberto C. Sanchez, Robin Barker, SADAHIRO 3126Tomoyuki, Salvador Ortiz Garcia, Sam Vilain, Scott Lanning, Sébastien 3127Aperghis-Tramoni, Sérgio Durigan Júnior, Shlomi Fish, Simon 'corecode' 3128Schubert, Sisyphus, Slaven Rezic, Smylers, Steffen Müller, Steffen 3129Ullrich, Stepan Kasal, Steve Hay, Steven Schubiger, Steve Peters, Tels, 3130The Doctor, Tim Bunce, Tim Jenness, Todd Rinaldo, Tom Christiansen, 3131Tom Hukins, Tom Wyant, Tony Cook, Torsten Schoenfeld, Tye McQueen, 3132Vadim Konovalov, Vincent Pit, Hio YAMASHINA, Yasuhiro Matsumoto, 3133Yitzchak Scott-Thoennes, Yuval Kogman, Yves Orton, Zefram, Zsban Ambrus 3134 3135This is woefully incomplete as it's automatically generated from version 3136control history. In particular, it doesn't include the names of the 3137(very much appreciated) contributors who reported issues in previous 3138versions of Perl that helped make Perl 5.12.0 better. For a more complete 3139list of all of Perl's historical contributors, please see the C<AUTHORS> 3140file in the Perl 5.12.0 distribution. 3141 3142Our "retired" pumpkings Nicholas Clark and Rafael Garcia-Suarez 3143deserve special thanks for their brilliant and substantive ongoing 3144contributions. Nicholas personally authored over 30% of the patches 3145since 5.10.0. Rafael comes in second in patch authorship with 11%, 3146but is first by a long shot in committing patches authored by others, 3147pushing 44% of the commits since 5.10.0 in this category, often after 3148providing considerable coaching to the patch authors. These statistics 3149in no way comprise all of their contributions, but express in shorthand 3150that we couldn't have done it without them. 3151 3152Many of the changes included in this version originated in the CPAN 3153modules included in Perl's core. We're grateful to the entire CPAN 3154community for helping Perl to flourish. 3155 3156=head1 Reporting Bugs 3157 3158If you find what you think is a bug, you might check the articles 3159recently posted to the comp.lang.perl.misc newsgroup and the perl 3160bug database at L<http://rt.perl.org/perlbug/>. There may also be 3161information at L<http://www.perl.org/>, the Perl Home Page. 3162 3163If you believe you have an unreported bug, please run the B<perlbug> 3164program included with your release. Be sure to trim your bug down 3165to a tiny but sufficient test case. Your bug report, along with the 3166output of C<perl -V>, will be sent off to perlbug@perl.org to be 3167analyzed by the Perl porting team. 3168 3169If the bug you are reporting has security implications, which make it 3170inappropriate to send to a publicly archived mailing list, then please send 3171it to perl5-security-report@perl.org. This points to a closed subscription 3172unarchived mailing list, which includes 3173all the core committers, who will be able 3174to help assess the impact of issues, figure out a resolution, and help 3175co-ordinate the release of patches to mitigate or fix the problem across all 3176platforms on which Perl is supported. Please only use this address for 3177security issues in the Perl core, not for modules independently 3178distributed on CPAN. 3179 3180=head1 SEE ALSO 3181 3182The F<Changes> file for an explanation of how to view exhaustive details 3183on what changed. 3184 3185The F<INSTALL> file for how to build Perl. 3186 3187The F<README> file for general stuff. 3188 3189The F<Artistic> and F<Copying> files for copyright information. 3190 3191L<http://dev.perl.org/perl5/errata.html> for a list of issues 3192found after this release, as well as a list of CPAN modules known 3193to be incompatible with this release. 3194 3195=cut 3196