| 1 | =encoding utf8 |
| 2 | |
| 3 | =head1 NAME |
| 4 | |
| 5 | perl5110delta - what is new for perl v5.11.0 |
| 6 | |
| 7 | =head1 DESCRIPTION |
| 8 | |
| 9 | This document describes differences between the 5.10.0 release and |
| 10 | the 5.11.0 development release. |
| 11 | |
| 12 | =head1 Incompatible Changes |
| 13 | |
| 14 | =head2 Unicode interpretation of \w, \d, \s, and the POSIX character classes redefined. |
| 15 | |
| 16 | Previous versions of Perl tried to map POSIX style character class definitions onto |
| 17 | Unicode property names so that patterns would "dwim" when matches were made against latin-1 or |
| 18 | unicode strings. This proved to be a mistake, breaking character class negation, causing |
| 19 | forward compatibility problems (as Unicode keeps updating their property definitions and adding |
| 20 | new characters), and other problems. |
| 21 | |
| 22 | Therefore we have now defined a new set of artificial "unicode" property names which will be |
| 23 | used to do unicode matching of patterns using POSIX style character classes and perl short-form |
| 24 | escape character classes like \w and \d. |
| 25 | |
| 26 | The key change here is that \d will no longer match every digit in the unicode standard |
| 27 | (there are thousands) nor will \w match every word character in the standard, instead they |
| 28 | will match precisely their POSIX or Perl definition. |
| 29 | |
| 30 | Those needing to match based on Unicode properties can continue to do so by using the \p{} syntax |
| 31 | to match whichever property they like, including the new artificial definitions. |
| 32 | |
| 33 | B<NOTE:> This is a backwards incompatible no-warning change in behaviour. If you are upgrading |
| 34 | and you process large volumes of text look for POSIX and Perl style character classes and |
| 35 | change them to the relevent property name (by removing the word 'Posix' from the current name). |
| 36 | |
| 37 | The following table maps the POSIX character class names, the escapes and the old and new |
| 38 | Unicode property mappings: |
| 39 | |
| 40 | POSIX Esc Class New-Property ! Old-Property |
| 41 | ----------------------------------------------+------------- |
| 42 | alnum [0-9A-Za-z] IsPosixAlnum ! IsAlnum |
| 43 | alpha [A-Za-z] IsPosixAlpha ! IsAlpha |
| 44 | ascii [\000-\177] IsASCII = IsASCII |
| 45 | blank [\011 ] IsPosixBlank ! |
| 46 | cntrl [\0-\37\177] IsPosixCntrl ! IsCntrl |
| 47 | digit \d [0-9] IsPosixDigit ! IsDigit |
| 48 | graph [!-~] IsPosixGraph ! IsGraph |
| 49 | lower [a-z] IsPosixLower ! IsLower |
| 50 | print [ -~] IsPosixPrint ! IsPrint |
| 51 | punct [!-/:-@[-`{-~] IsPosixPunct ! IsPunct |
| 52 | space [\11-\15 ] IsPosixSpace ! IsSpace |
| 53 | \s [\11\12\14\15 ] IsPerlSpace ! IsSpacePerl |
| 54 | upper [A-Z] IsPosixUpper ! IsUpper |
| 55 | word \w [0-9A-Z_a-z] IsPerlWord ! IsWord |
| 56 | xdigit [0-9A-Fa-f] IsXDigit = IsXDigit |
| 57 | |
| 58 | If you wish to build perl with the old mapping you may do so by setting |
| 59 | |
| 60 | #define PERL_LEGACY_UNICODE_CHARCLASS_MAPPINGS 1 |
| 61 | |
| 62 | in regcomp.h, and then setting |
| 63 | |
| 64 | PERL_TEST_LEGACY_POSIX_CC |
| 65 | |
| 66 | to true your enviornment when testing. |
| 67 | |
| 68 | |
| 69 | =head2 @INC reorganization |
| 70 | |
| 71 | In @INC, ARCHLIB and PRIVLIB now occur after after the current version's |
| 72 | site_perl and vendor_perl. |
| 73 | |
| 74 | =head2 Switch statement changes |
| 75 | |
| 76 | The handling of complex expressions by the C<given>/C<when> switch |
| 77 | statement has been enhanced. These enhancements are also available in |
| 78 | 5.10.1 and subsequent 5.10 releases. There are two new cases where C<when> now |
| 79 | interprets its argument as a boolean, instead of an expression to be used |
| 80 | in a smart match: |
| 81 | |
| 82 | =over 4 |
| 83 | |
| 84 | =item flip-flop operators |
| 85 | |
| 86 | The C<..> and C<...> flip-flop operators are now evaluated in boolean |
| 87 | context, following their usual semantics; see L<perlop/"Range Operators">. |
| 88 | |
| 89 | Note that, as in perl 5.10.0, C<when (1..10)> will not work to test |
| 90 | whether a given value is an integer between 1 and 10; you should use |
| 91 | C<when ([1..10])> instead (note the array reference). |
| 92 | |
| 93 | However, contrary to 5.10.0, evaluating the flip-flop operators in boolean |
| 94 | context ensures it can now be useful in a C<when()>, notably for |
| 95 | implementing bistable conditions, like in: |
| 96 | |
| 97 | when (/^=begin/ .. /^=end/) { |
| 98 | # do something |
| 99 | } |
| 100 | |
| 101 | =item defined-or operator |
| 102 | |
| 103 | A compound expression involving the defined-or operator, as in |
| 104 | C<when (expr1 // expr2)>, will be treated as boolean if the first |
| 105 | expression is boolean. (This just extends the existing rule that applies |
| 106 | to the regular or operator, as in C<when (expr1 || expr2)>.) |
| 107 | |
| 108 | =back |
| 109 | |
| 110 | The next section details more changes brought to the semantics to |
| 111 | the smart match operator, that naturally also modify the behaviour |
| 112 | of the switch statements where smart matching is implicitly used. |
| 113 | These changers were also made for the 5.10.1 release, and will remain in |
| 114 | subsequent 5.10 releases. |
| 115 | |
| 116 | =head2 Smart match changes |
| 117 | |
| 118 | =head3 Changes to type-based dispatch |
| 119 | |
| 120 | The smart match operator C<~~> is no longer commutative. The behaviour of |
| 121 | a smart match now depends primarily on the type of its right hand |
| 122 | argument. Moreover, its semantics have been adjusted for greater |
| 123 | consistency or usefulness in several cases. While the general backwards |
| 124 | compatibility is maintained, several changes must be noted: |
| 125 | |
| 126 | =over 4 |
| 127 | |
| 128 | =item * |
| 129 | |
| 130 | Code references with an empty prototype are no longer treated specially. |
| 131 | They are passed an argument like the other code references (even if they |
| 132 | choose to ignore it). |
| 133 | |
| 134 | =item * |
| 135 | |
| 136 | C<%hash ~~ sub {}> and C<@array ~~ sub {}> now test that the subroutine |
| 137 | returns a true value for each key of the hash (or element of the |
| 138 | array), instead of passing the whole hash or array as a reference to |
| 139 | the subroutine. |
| 140 | |
| 141 | =item * |
| 142 | |
| 143 | Due to the commutativity breakage, code references are no longer |
| 144 | treated specially when appearing on the left of the C<~~> operator, |
| 145 | but like any vulgar scalar. |
| 146 | |
| 147 | =item * |
| 148 | |
| 149 | C<undef ~~ %hash> is always false (since C<undef> can't be a key in a |
| 150 | hash). No implicit conversion to C<""> is done (as was the case in perl |
| 151 | 5.10.0). |
| 152 | |
| 153 | =item * |
| 154 | |
| 155 | C<$scalar ~~ @array> now always distributes the smart match across the |
| 156 | elements of the array. It's true if one element in @array verifies |
| 157 | C<$scalar ~~ $element>. This is a generalization of the old behaviour |
| 158 | that tested whether the array contained the scalar. |
| 159 | |
| 160 | =back |
| 161 | |
| 162 | The full dispatch table for the smart match operator is given in |
| 163 | L<perlsyn/"Smart matching in detail">. |
| 164 | |
| 165 | =head3 Smart match and overloading |
| 166 | |
| 167 | According to the rule of dispatch based on the rightmost argument type, |
| 168 | when an object overloading C<~~> appears on the right side of the |
| 169 | operator, the overload routine will always be called (with a 3rd argument |
| 170 | set to a true value, see L<overload>.) However, when the object will |
| 171 | appear on the left, the overload routine will be called only when the |
| 172 | rightmost argument is a simple scalar. This way distributivity of smart match |
| 173 | across arrays is not broken, as well as the other behaviours with complex |
| 174 | types (coderefs, hashes, regexes). Thus, writers of overloading routines |
| 175 | for smart match mostly need to worry only with comparing against a scalar, |
| 176 | and possibly with stringification overloading; the other common cases |
| 177 | will be automatically handled consistently. |
| 178 | |
| 179 | C<~~> will now refuse to work on objects that do not overload it (in order |
| 180 | to avoid relying on the object's underlying structure). (However, if the |
| 181 | object overloads the stringification or the numification operators, and |
| 182 | if overload fallback is active, it will be used instead, as usual.) |
| 183 | |
| 184 | =head2 Labels can't be keywords |
| 185 | |
| 186 | Labels used as targets for the C<goto>, C<last>, C<next> or C<redo> |
| 187 | statements cannot be keywords anymore. This restriction will prevent |
| 188 | potential confusion between the C<goto LABEL> and C<goto EXPR> syntaxes: |
| 189 | for example, a statement like C<goto print> would jump to a label whose |
| 190 | name would be the return value of C<print()>, (usually 1), instead of a |
| 191 | label named C<print>. Moreover, the other control flow statements |
| 192 | would just ignore any keyword passed to them as a label name. Since |
| 193 | such labels cannot be defined anymore, this kind of error will be |
| 194 | avoided. |
| 195 | |
| 196 | =head2 Other incompatible changes |
| 197 | |
| 198 | =over 4 |
| 199 | |
| 200 | =item * |
| 201 | |
| 202 | The semantics of C<use feature :5.10*> have changed slightly. |
| 203 | See L<"Modules and Pragmata"> for more information. |
| 204 | |
| 205 | =item * |
| 206 | |
| 207 | It is now a run-time error to use the smart match operator C<~~> |
| 208 | with an object that has no overload defined for it. (This way |
| 209 | C<~~> will not break encapsulation by matching against the |
| 210 | object's internal representation as a reference.) |
| 211 | |
| 212 | =item * |
| 213 | |
| 214 | The version control system used for the development of the perl |
| 215 | interpreter has been switched from Perforce to git. This is mainly an |
| 216 | internal issue that only affects people actively working on the perl core; |
| 217 | but it may have minor external visibility, for example in some of details |
| 218 | of the output of C<perl -V>. See L<perlrepository> for more information. |
| 219 | |
| 220 | =item * |
| 221 | |
| 222 | The internal structure of the C<ext/> directory in the perl source has |
| 223 | been reorganised. In general, a module C<Foo::Bar> whose source was |
| 224 | stored under F<ext/Foo/Bar/> is now located under F<ext/Foo-Bar/>. Also, |
| 225 | nearly all dual-life modules have been moved from F<lib/> to F<ext/>. This |
| 226 | is purely a source tarball change, and should make no difference to the |
| 227 | compilation or installation of perl, unless you have a very customised build |
| 228 | process that explicitly relies on this structure, or which hard-codes the |
| 229 | C<nonxs_ext> F<Configure> parameter. Specifically, this change does not by |
| 230 | default alter the location of any files in the final installation. |
| 231 | |
| 232 | =item * |
| 233 | |
| 234 | As part of the C<Test::Harness> 2.x to 3.x upgrade, the experimental |
| 235 | C<Test::Harness::Straps> module has been removed. |
| 236 | See L</"Updated Modules"> for more details. |
| 237 | |
| 238 | =item * |
| 239 | |
| 240 | As part of the C<ExtUtils::MakeMaker> upgrade, the |
| 241 | C<ExtUtils::MakeMaker::bytes> and C<ExtUtils::MakeMaker::vmsish> modules |
| 242 | have been removed from this distribution. |
| 243 | |
| 244 | =item * |
| 245 | |
| 246 | C<Module::CoreList> no longer contains the C<%:patchlevel> hash. |
| 247 | |
| 248 | =item * |
| 249 | |
| 250 | This one is actually a change introduced in 5.10.0, but it was missed |
| 251 | from that release's perldelta, so it is mentioned here instead. |
| 252 | |
| 253 | A bugfix related to the handling of the C</m> modifier and C<qr> resulted |
| 254 | in a change of behaviour between 5.8.x and 5.10.0: |
| 255 | |
| 256 | # matches in 5.8.x, doesn't match in 5.10.0 |
| 257 | $re = qr/^bar/; "foo\nbar" =~ /$re/m; |
| 258 | |
| 259 | =item * |
| 260 | |
| 261 | C<length undef> now returns undef. |
| 262 | |
| 263 | =item * |
| 264 | |
| 265 | Unsupported private C API functions are now declared "static" to prevent |
| 266 | leakage to Perl's public API. |
| 267 | |
| 268 | =item * |
| 269 | |
| 270 | To support the bootstrapping process, F<miniperl> no longer builds with |
| 271 | UTF-8 support in the regexp engine. |
| 272 | |
| 273 | This allows a build to complete with PERL_UNICODE set and a UTF-8 locale. |
| 274 | Without this there's a bootstrapping problem, as miniperl can't load the UTF-8 |
| 275 | components of the regexp engine, because they're not yet built. |
| 276 | |
| 277 | =item * |
| 278 | |
| 279 | F<miniperl>'s @INC is now restricted to just -I..., the split of $ENV{PERL5LIB}, and "." |
| 280 | |
| 281 | =item * |
| 282 | |
| 283 | A space or a newline is now required after a C<"#line XXX"> directive. |
| 284 | |
| 285 | =item * |
| 286 | |
| 287 | Tied filehandles now have an additional method EOF which provides the EOF type |
| 288 | |
| 289 | =item * |
| 290 | |
| 291 | To better match all other flow control statements, C<foreach> may no longer be used as an attribute. |
| 292 | |
| 293 | =back |
| 294 | |
| 295 | =head1 Core Enhancements |
| 296 | |
| 297 | =head2 Unicode Character Database 5.1.0 |
| 298 | |
| 299 | The copy of the Unicode Character Database included in Perl 5.11.0 has |
| 300 | been updated to 5.1.0 from 5.0.0. See |
| 301 | L<http://www.unicode.org/versions/Unicode5.1.0/#Notable_Changes> for the |
| 302 | notable changes. |
| 303 | |
| 304 | =head2 A proper interface for pluggable Method Resolution Orders |
| 305 | |
| 306 | As of Perl 5.11.0 there is a new interface for plugging and using method |
| 307 | resolution orders other than the default (linear depth first search). |
| 308 | The C3 method resolution order added in 5.10.0 has been re-implemented as |
| 309 | a plugin, without changing its Perl-space interface. See L<perlmroapi> for |
| 310 | more information. |
| 311 | |
| 312 | =head2 The C<overloading> pragma |
| 313 | |
| 314 | This pragma allows you to lexically disable or enable overloading |
| 315 | for some or all operations. (Yuval Kogman) |
| 316 | |
| 317 | =head2 C<\N> regex escape |
| 318 | |
| 319 | A new regex escape has been added, C<\N>. It will match any character that |
| 320 | is not a newline, independently from the presence or absence of the single |
| 321 | line match modifier C</s>. (If C<\N> is followed by an opening brace and |
| 322 | by a letter, perl will still assume that a Unicode character name is |
| 323 | coming, so compatibility is preserved.) (Rafael Garcia-Suarez) |
| 324 | |
| 325 | =head2 Implicit strictures |
| 326 | |
| 327 | Using the C<use VERSION> syntax with a version number greater or equal |
| 328 | to 5.11.0 will also lexically enable strictures just like C<use strict> |
| 329 | would do (in addition to enabling features.) So, the following: |
| 330 | |
| 331 | use 5.11.0; |
| 332 | |
| 333 | will now imply: |
| 334 | |
| 335 | use strict; |
| 336 | use feature ':5.11'; |
| 337 | |
| 338 | =head2 Parallel tests |
| 339 | |
| 340 | The core distribution can now run its regression tests in parallel on |
| 341 | Unix-like platforms. Instead of running C<make test>, set C<TEST_JOBS> in |
| 342 | your environment to the number of tests to run in parallel, and run |
| 343 | C<make test_harness>. On a Bourne-like shell, this can be done as |
| 344 | |
| 345 | TEST_JOBS=3 make test_harness # Run 3 tests in parallel |
| 346 | |
| 347 | An environment variable is used, rather than parallel make itself, because |
| 348 | L<TAP::Harness> needs to be able to schedule individual non-conflicting test |
| 349 | scripts itself, and there is no standard interface to C<make> utilities to |
| 350 | interact with their job schedulers. |
| 351 | |
| 352 | Note that currently some test scripts may fail when run in parallel (most |
| 353 | notably C<ext/IO/t/io_dir.t>). If necessary run just the failing scripts |
| 354 | again sequentially and see if the failures go away. |
| 355 | |
| 356 | =head2 The C<...> operator |
| 357 | |
| 358 | A new operator, C<...>, nicknamed the Yada Yada operator, has been added. |
| 359 | It is intended to mark placeholder code, that is not yet implemented. |
| 360 | See L<perlop/"Yada Yada Operator">. (chromatic) |
| 361 | |
| 362 | =head2 DTrace support |
| 363 | |
| 364 | Some support for DTrace has been added. See "DTrace support" in F<INSTALL>. |
| 365 | |
| 366 | =head2 Support for C<configure_requires> in CPAN module metadata |
| 367 | |
| 368 | Both C<CPAN> and C<CPANPLUS> now support the C<configure_requires> keyword |
| 369 | in the F<META.yml> metadata file included in most recent CPAN distributions. |
| 370 | This allows distribution authors to specify configuration prerequisites that |
| 371 | must be installed before running F<Makefile.PL> or F<Build.PL>. |
| 372 | |
| 373 | See the documentation for C<ExtUtils::MakeMaker> or C<Module::Build> for more |
| 374 | on how to specify C<configure_requires> when creating a distribution for CPAN. |
| 375 | |
| 376 | =head2 C<each> is now more flexible |
| 377 | |
| 378 | The C<each> function can now operate on arrays. |
| 379 | |
| 380 | =head2 Y2038 compliance |
| 381 | |
| 382 | Perl's core time-related functions are now Y2038 compliant. (With 29 |
| 383 | years to spare!) |
| 384 | |
| 385 | =head2 C<$,> flexibility |
| 386 | |
| 387 | The variable C<$,> may now be tied. |
| 388 | |
| 389 | =head2 // in where clauses |
| 390 | |
| 391 | // now behaves like || in when clauses |
| 392 | |
| 393 | =head2 Enabling warnings from your shell environment |
| 394 | |
| 395 | You can now set C<-W> from the C<PERL5OPT> environment variable |
| 396 | |
| 397 | =head2 C<delete local> |
| 398 | |
| 399 | C<delete local> now allows you to locally delete a hash entry. |
| 400 | |
| 401 | =head2 New support for Abstract namespace sockets |
| 402 | |
| 403 | Abstract namespace sockets are Linux-specific socket type that live in |
| 404 | AF_UNIX family, slightly abusing it to be able to use arbitrary |
| 405 | character arrays as addresses: They start with nul byte and are not |
| 406 | terminated by nul byte, but with the length passed to the socket() |
| 407 | system call. |
| 408 | |
| 409 | =head1 Modules and Pragmata |
| 410 | |
| 411 | =head2 Dual-lifed modules moved |
| 412 | |
| 413 | Dual-lifed modules maintained primarily in the Perl core now live in dist/. |
| 414 | Dual-lifed modules maintained primarily on CPAN now live in cpan/ |
| 415 | |
| 416 | In previous releases of Perl, it was customary to enumerate all module |
| 417 | changes in this section of the C<perldelta> file. From 5.11.0 forward |
| 418 | only notable updates (such as new or deprecated modules ) will be |
| 419 | listed in this section. For a complete reference to the versions of |
| 420 | modules shipped in a given release of perl, please see L<Module::CoreList>. |
| 421 | |
| 422 | =head2 New Modules and Pragmata |
| 423 | |
| 424 | =over 4 |
| 425 | |
| 426 | =item C<autodie> |
| 427 | |
| 428 | This is a new lexically-scoped alternative for the C<Fatal> module. |
| 429 | The bundled version is 2.06_01. Note that in this release, using a string |
| 430 | eval when C<autodie> is in effect can cause the autodie behaviour to leak |
| 431 | into the surrounding scope. See L<autodie/"BUGS"> for more details. |
| 432 | |
| 433 | =item C<Compress::Raw::Bzip2> |
| 434 | |
| 435 | This has been added to the core (version 2.020). |
| 436 | |
| 437 | =item C<parent> |
| 438 | |
| 439 | This pragma establishes an ISA relationship with base classes at compile |
| 440 | time. It provides the key feature of C<base> without the feature creep. |
| 441 | |
| 442 | =item C<Parse::CPAN::Meta> |
| 443 | |
| 444 | This has been added to the core (version 1.39). |
| 445 | |
| 446 | =back |
| 447 | |
| 448 | =head2 Pragmata Changes |
| 449 | |
| 450 | =over 4 |
| 451 | |
| 452 | =item C<overloading> |
| 453 | |
| 454 | See L</"The C<overloading> pragma"> above. |
| 455 | |
| 456 | =item C<attrs> |
| 457 | |
| 458 | The C<attrs> pragma has been removed. It had been marked as deprecated since |
| 459 | 5.6.0. |
| 460 | |
| 461 | =item C<charnames> |
| 462 | |
| 463 | The Unicode F<NameAliases.txt> database file has been added. This has the |
| 464 | effect of adding some extra C<\N> character names that formerly wouldn't |
| 465 | have been recognised; for example, C<"\N{LATIN CAPITAL LETTER GHA}">. |
| 466 | |
| 467 | =item C<feature> |
| 468 | |
| 469 | The meaning of the C<:5.10> and C<:5.10.X> feature bundles has |
| 470 | changed slightly. The last component, if any (i.e. C<X>) is simply ignored. |
| 471 | This is predicated on the assumption that new features will not, in |
| 472 | general, be added to maintenance releases. So C<:5.10> and C<:5.10.X> |
| 473 | have identical effect. This is a change to the behaviour documented for |
| 474 | 5.10.0. |
| 475 | |
| 476 | =item C<mro> |
| 477 | |
| 478 | Upgraded from version 1.00 to 1.01. Performance for single inheritance is 40% |
| 479 | faster - see L</"Performance Enhancements"> below. |
| 480 | |
| 481 | C<mro> is now implemented as an XS extension. The documented interface has not |
| 482 | changed. Code relying on the implementation detail that some C<mro::> |
| 483 | methods happened to be available at all times gets to "keep both pieces". |
| 484 | |
| 485 | =back |
| 486 | |
| 487 | =head2 Updated Modules |
| 488 | |
| 489 | =over 4 |
| 490 | |
| 491 | =item C<ExtUtils::MakeMaker> |
| 492 | |
| 493 | Upgraded from version 6.42 to 6.55_02. |
| 494 | |
| 495 | Note that C<ExtUtils::MakeMaker::bytes> and C<ExtUtils::MakeMaker::vmsish> |
| 496 | have been removed from this distribution. |
| 497 | |
| 498 | =item C<Test::Harness> |
| 499 | |
| 500 | Upgraded from version 2.64 to 3.17. |
| 501 | |
| 502 | Note that one side-effect of the 2.x to 3.x upgrade is that the |
| 503 | experimental C<Test::Harness::Straps> module (and its supporting |
| 504 | C<Assert>, C<Iterator>, C<Point> and C<Results> modules) have been |
| 505 | removed. If you still need this, then they are available in the |
| 506 | (unmaintained) C<Test-Harness-Straps> distribution on CPAN. |
| 507 | |
| 508 | =item C<UNIVERSAL> |
| 509 | |
| 510 | Upgraded from version 1.04 to 1.05. |
| 511 | |
| 512 | C<< UNIVERSAL-E<gt>import() >> is now deprecated. |
| 513 | |
| 514 | =back |
| 515 | |
| 516 | =head1 Utility Changes |
| 517 | |
| 518 | =over 4 |
| 519 | |
| 520 | =item F<h2ph> |
| 521 | |
| 522 | Now looks in C<include-fixed> too, which is a recent addition to gcc's |
| 523 | search path. |
| 524 | |
| 525 | =item F<h2xs> |
| 526 | |
| 527 | No longer incorrectly treats enum values like macros (Daniel Burr). |
| 528 | |
| 529 | Now handles C++ style constants (C<//>) properly in enums. (A patch from |
| 530 | Rainer Weikusat was used; Daniel Burr also proposed a similar fix). |
| 531 | |
| 532 | =item F<perl5db.pl> |
| 533 | |
| 534 | C<LVALUE> subroutines now work under the debugger. |
| 535 | |
| 536 | The debugger now correctly handles proxy constant subroutines, and |
| 537 | subroutine stubs. |
| 538 | |
| 539 | =item F<perlbug> |
| 540 | |
| 541 | F<perlbug> now uses C<%Module::CoreList::bug_tracker> to print out upstream bug |
| 542 | tracker URLs. |
| 543 | |
| 544 | Where the user names a module that their bug report is about, and we know the |
| 545 | URL for its upstream bug tracker, provide a message to the user explaining |
| 546 | that the core copies the CPAN version directly, and provide the URL for |
| 547 | reporting the bug directly to upstream. |
| 548 | |
| 549 | =item F<perlthanks> |
| 550 | |
| 551 | Perl 5.11.0 added a new utility F<perlthanks>, which is a variant of |
| 552 | F<perlbug>, but for sending non-bug-reports to the authors and maintainers |
| 553 | of Perl. Getting nothing but bug reports can become a bit demoralising: |
| 554 | we'll see if this changes things. |
| 555 | |
| 556 | =back |
| 557 | |
| 558 | =head1 New Documentation |
| 559 | |
| 560 | =over 4 |
| 561 | |
| 562 | =item L<perlhaiku> |
| 563 | |
| 564 | This contains instructions on how to build perl for the Haiku platform. |
| 565 | |
| 566 | =item L<perlmroapi> |
| 567 | |
| 568 | This describes the new interface for pluggable Method Resolution Orders. |
| 569 | |
| 570 | =item L<perlperf> |
| 571 | |
| 572 | This document, by Richard Foley, provides an introduction to the use of |
| 573 | performance and optimization techniques which can be used with particular |
| 574 | reference to perl programs. |
| 575 | |
| 576 | =item L<perlrepository> |
| 577 | |
| 578 | This describes how to access the perl source using the I<git> version |
| 579 | control system. |
| 580 | |
| 581 | =back |
| 582 | |
| 583 | =head1 Changes to Existing Documentation |
| 584 | |
| 585 | The various large F<Changes*> files (which listed every change made to perl |
| 586 | over the last 18 years) have been removed, and replaced by a small file, |
| 587 | also called F<Changes>, which just explains how that same information may |
| 588 | be extracted from the git version control system. |
| 589 | |
| 590 | The file F<Porting/patching.pod> has been deleted, as it mainly described |
| 591 | interacting with the old Perforce-based repository, which is now obsolete. |
| 592 | Information still relevant has been moved to L<perlrepository>. |
| 593 | |
| 594 | L<perlapi>, L<perlintern>, L<perlmodlib> and L<perltoc> are now all |
| 595 | generated at build time, rather than being shipped as part of the release. |
| 596 | |
| 597 | =over |
| 598 | |
| 599 | =item * |
| 600 | |
| 601 | Documented -X overloading. |
| 602 | |
| 603 | =item * |
| 604 | |
| 605 | Documented that C<when()> treats specially most of the filetest operators |
| 606 | |
| 607 | =item * |
| 608 | |
| 609 | Documented when as a syntax modifier |
| 610 | |
| 611 | =item * |
| 612 | |
| 613 | Eliminated "Old Perl threads tutorial", which describes 5005 threads. |
| 614 | |
| 615 | F<pod/perlthrtut.pod> is the same material reworked for ithreads. |
| 616 | |
| 617 | =item * |
| 618 | |
| 619 | Correct previous documentation: v-strings are not deprecated |
| 620 | |
| 621 | With version objects, we need them to use MODULE VERSION syntax. This |
| 622 | patch removes the deprecation note. |
| 623 | |
| 624 | =item * |
| 625 | |
| 626 | Added security contact information to L<perlsec> |
| 627 | |
| 628 | =back |
| 629 | |
| 630 | =head1 Performance Enhancements |
| 631 | |
| 632 | |
| 633 | =over 4 |
| 634 | |
| 635 | =item * |
| 636 | |
| 637 | A new internal cache means that C<isa()> will often be faster. |
| 638 | |
| 639 | =item * |
| 640 | |
| 641 | The implementation of C<C3> Method Resolution Order has been optimised - |
| 642 | linearisation for classes with single inheritance is 40% faster. Performance |
| 643 | for multiple inheritance is unchanged. |
| 644 | |
| 645 | =item * |
| 646 | |
| 647 | Under C<use locale>, the locale-relevant information is now cached on |
| 648 | read-only values, such as the list returned by C<keys %hash>. This makes |
| 649 | operations such as C<sort keys %hash> in the scope of C<use locale> much |
| 650 | faster. |
| 651 | |
| 652 | =item * |
| 653 | |
| 654 | Empty C<DESTROY> methods are no longer called. |
| 655 | |
| 656 | =item * |
| 657 | |
| 658 | Faster C<Perl_sv_utf8_upgrade()> |
| 659 | |
| 660 | =item * |
| 661 | |
| 662 | Speed up C<keys> on empty hash |
| 663 | |
| 664 | =back |
| 665 | |
| 666 | =head1 Installation and Configuration Improvements |
| 667 | |
| 668 | =head2 F<ext/> reorganisation |
| 669 | |
| 670 | The layout of directories in F<ext> has been revised. Specifically, all |
| 671 | extensions are now flat, and at the top level, with C</> in pathnames |
| 672 | replaced by C<->, so that F<ext/Data/Dumper/> is now F<ext/Data-Dumper/>, |
| 673 | etc. The names of the extensions as specified to F<Configure>, and as |
| 674 | reported by C<%Config::Config> under the keys C<dynamic_ext>, |
| 675 | C<known_extensions>, C<nonxs_ext> and C<static_ext> have not changed, and |
| 676 | still use C</>. Hence this change will not have any affect once perl is |
| 677 | installed. C<Safe> has been split out from being part of C<Opcode>, and |
| 678 | C<mro> is now an extension in its own right. |
| 679 | |
| 680 | Nearly all dual-life modules have been moved from F<lib> to F<ext>, and will |
| 681 | now appear as known C<nonxs_ext>. This will made no difference to the |
| 682 | structure of an installed perl, nor will the modules installed differ, |
| 683 | unless you run F<Configure> with options to specify an exact list of |
| 684 | extensions to build. In this case, you will rapidly become aware that you |
| 685 | need to add to your list, because various modules needed to complete the |
| 686 | build, such as C<ExtUtils::ParseXS>, have now become extensions, and |
| 687 | without them the build will fail well before it attempts to run the |
| 688 | regression tests. |
| 689 | |
| 690 | =head2 Configuration improvements |
| 691 | |
| 692 | If C<vendorlib> and C<vendorarch> are the same, then they are only added to |
| 693 | C<@INC> once. |
| 694 | |
| 695 | C<$Config{usedevel}> and the C-level C<PERL_USE_DEVEL> are now defined if |
| 696 | perl is built with C<-Dusedevel>. |
| 697 | |
| 698 | F<Configure> will enable use of C<-fstack-protector>, to provide protection |
| 699 | against stack-smashing attacks, if the compiler supports it. |
| 700 | |
| 701 | F<Configure> will now determine the correct prototypes for re-entrant |
| 702 | functions, and for C<gconvert>, if you are using a C++ compiler rather |
| 703 | than a C compiler. |
| 704 | |
| 705 | On Unix, if you build from a tree containing a git repository, the |
| 706 | configuration process will note the commit hash you have checked out, for |
| 707 | display in the output of C<perl -v> and C<perl -V>. Unpushed local commits |
| 708 | are automatically added to the list of local patches displayed by |
| 709 | C<perl -V>. |
| 710 | |
| 711 | =head2 Compilation improvements |
| 712 | |
| 713 | As part of the flattening of F<ext>, all extensions on all platforms are |
| 714 | built by F<make_ext.pl>. This replaces the Unix-specific |
| 715 | F<ext/util/make_ext>, VMS-specific F<make_ext.com> and Win32-specific |
| 716 | F<win32/buildext.pl>. |
| 717 | |
| 718 | =head2 Platform Specific Changes |
| 719 | |
| 720 | =over 4 |
| 721 | |
| 722 | =item AIX |
| 723 | |
| 724 | Removed F<libbsd> for AIX 5L and 6.1. Only C<flock()> was used from F<libbsd>. |
| 725 | |
| 726 | Removed F<libgdbm> for AIX 5L and 6.1. The F<libgdbm> is delivered as an |
| 727 | optional package with the AIX Toolbox. Unfortunately the 64 bit version |
| 728 | is broken. |
| 729 | |
| 730 | Hints changes mean that AIX 4.2 should work again. |
| 731 | |
| 732 | =item Cygwin |
| 733 | |
| 734 | On Cygwin we now strip the last number from the DLL. This has been the |
| 735 | behaviour in the cygwin.com build for years. The hints files have been |
| 736 | updated. |
| 737 | |
| 738 | =item DomainOS |
| 739 | |
| 740 | Support for Apollo DomainOS was removed in Perl 5.11.0 |
| 741 | |
| 742 | =item FreeBSD |
| 743 | |
| 744 | The hints files now identify the correct threading libraries on FreeBSD 7 |
| 745 | and later. |
| 746 | |
| 747 | =item Irix |
| 748 | |
| 749 | We now work around a bizarre preprocessor bug in the Irix 6.5 compiler: |
| 750 | C<cc -E -> unfortunately goes into K&R mode, but C<cc -E file.c> doesn't. |
| 751 | |
| 752 | =item Haiku |
| 753 | |
| 754 | Patches from the Haiku maintainers have been merged in. Perl should now |
| 755 | build on Haiku. |
| 756 | |
| 757 | =item MachTen |
| 758 | |
| 759 | Support for Tenon Intersystems MachTen Unix layer for MacOS Classic was |
| 760 | removed in Perl 5.11.0 |
| 761 | |
| 762 | =item MiNT |
| 763 | |
| 764 | Support for Atari MiNT was removed in Perl 5.11.0. |
| 765 | |
| 766 | =item MirOS BSD |
| 767 | |
| 768 | Perl should now build on MirOS BSD. |
| 769 | |
| 770 | =item NetBSD |
| 771 | |
| 772 | Hints now supports versions 5.*. |
| 773 | |
| 774 | =item Stratus VOS |
| 775 | |
| 776 | Various changes from Stratus have been merged in. |
| 777 | |
| 778 | =item Symbian |
| 779 | |
| 780 | There is now support for Symbian S60 3.2 SDK and S60 5.0 SDK. |
| 781 | |
| 782 | =item Win32 |
| 783 | |
| 784 | Improved message window handling means that C<alarm> and C<kill> messages |
| 785 | will no longer be dropped under race conditions. |
| 786 | |
| 787 | =item VMS |
| 788 | |
| 789 | Reads from the in-memory temporary files of C<PerlIO::scalar> used to fail |
| 790 | if C<$/> was set to a numeric reference (to indicate record-style reads). |
| 791 | This is now fixed. |
| 792 | |
| 793 | VMS now supports C<getgrgid>. |
| 794 | |
| 795 | Many improvements and cleanups have been made to the VMS file name handling |
| 796 | and conversion code. |
| 797 | |
| 798 | Enabling the C<PERL_VMS_POSIX_EXIT> logical name now encodes a POSIX exit |
| 799 | status in a VMS condition value for better interaction with GNV's bash |
| 800 | shell and other utilities that depend on POSIX exit values. See |
| 801 | L<perlvms/"$?"> for details. |
| 802 | |
| 803 | C<File::Copy> now detects Unix compatibility mode on VMS. |
| 804 | |
| 805 | =back |
| 806 | |
| 807 | =head1 Selected Bug Fixes |
| 808 | |
| 809 | =over 4 |
| 810 | |
| 811 | =item * |
| 812 | |
| 813 | C<-I> on shebang line now adds directories in front of @INC |
| 814 | as documented, and as does C<-I> when specified on the command-line. |
| 815 | |
| 816 | =item * |
| 817 | |
| 818 | C<kill> is now fatal when called on non-numeric process identifiers. |
| 819 | Previously, an 'undef' process identifier would be interpreted as a request to |
| 820 | kill process "0", which would terminate the current process group on POSIX |
| 821 | systems. Since process identifiers are always integers, killing a non-numeric |
| 822 | process is now fatal. |
| 823 | |
| 824 | =item * |
| 825 | |
| 826 | 5.10.0 inadvertently disabled an optimisation, which caused a measurable |
| 827 | performance drop in list assignment, such as is often used to assign |
| 828 | function parameters from C<@_>. The optimisation has been re-instated, and |
| 829 | the performance regression fixed. |
| 830 | |
| 831 | =item * |
| 832 | |
| 833 | Fixed memory leak on C<while (1) { map 1, 1 }> [RT #53038]. |
| 834 | |
| 835 | =item * |
| 836 | |
| 837 | Some potential coredumps in PerlIO fixed [RT #57322,54828]. |
| 838 | |
| 839 | =item * |
| 840 | |
| 841 | The debugger now works with lvalue subroutines. |
| 842 | |
| 843 | =item * |
| 844 | |
| 845 | The debugger's C<m> command was broken on modules that defined constants |
| 846 | [RT #61222]. |
| 847 | |
| 848 | =item * |
| 849 | |
| 850 | C<crypt> and string complement could return tainted values for untainted |
| 851 | arguments [RT #59998]. |
| 852 | |
| 853 | =item * |
| 854 | |
| 855 | The C<-i>I<.suffix> command-line switch now recreates the file using |
| 856 | restricted permissions, before changing its mode to match the original |
| 857 | file. This eliminates a potential race condition [RT #60904]. |
| 858 | |
| 859 | =item * |
| 860 | |
| 861 | On some UNIX systems, the value in C<$?> would not have the top bit set |
| 862 | (C<$? & 128>) even if the child core dumped. |
| 863 | |
| 864 | =item * |
| 865 | |
| 866 | Under some circumstances, C<$^R> could incorrectly become undefined |
| 867 | [RT #57042]. |
| 868 | |
| 869 | =item * |
| 870 | |
| 871 | In the XS API, various hash functions, when passed a pre-computed hash where |
| 872 | the key is UTF-8, might result in an incorrect lookup. |
| 873 | |
| 874 | =item * |
| 875 | |
| 876 | XS code including F<XSUB.h> before F<perl.h> gave a compile-time error |
| 877 | [RT #57176]. |
| 878 | |
| 879 | =item * |
| 880 | |
| 881 | C<< $object-E<gt>isa('Foo') >> would report false if the package C<Foo> didn't |
| 882 | exist, even if the object's C<@ISA> contained C<Foo>. |
| 883 | |
| 884 | =item * |
| 885 | |
| 886 | Various bugs in the new-to 5.10.0 mro code, triggered by manipulating |
| 887 | C<@ISA>, have been found and fixed. |
| 888 | |
| 889 | =item * |
| 890 | |
| 891 | Bitwise operations on references could crash the interpreter, e.g. |
| 892 | C<$x=\$y; $x |= "foo"> [RT #54956]. |
| 893 | |
| 894 | =item * |
| 895 | |
| 896 | Patterns including alternation might be sensitive to the internal UTF-8 |
| 897 | representation, e.g. |
| 898 | |
| 899 | my $byte = chr(192); |
| 900 | my $utf8 = chr(192); utf8::upgrade($utf8); |
| 901 | $utf8 =~ /$byte|X}/i; # failed in 5.10.0 |
| 902 | |
| 903 | =item * |
| 904 | |
| 905 | Within UTF8-encoded Perl source files (i.e. where C<use utf8> is in |
| 906 | effect), double-quoted literal strings could be corrupted where a C<\xNN>, |
| 907 | C<\0NNN> or C<\N{}> is followed by a literal character with ordinal value |
| 908 | greater than 255 [RT #59908]. |
| 909 | |
| 910 | =item * |
| 911 | |
| 912 | C<B::Deparse> failed to correctly deparse various constructs: |
| 913 | C<readpipe STRING> [RT #62428], C<CORE::require(STRING)> [RT #62488], |
| 914 | C<sub foo(_)> [RT #62484]. |
| 915 | |
| 916 | =item * |
| 917 | |
| 918 | Using C<setpgrp> with no arguments could corrupt the perl stack. |
| 919 | |
| 920 | =item * |
| 921 | |
| 922 | The block form of C<eval> is now specifically trappable by C<Safe> and |
| 923 | C<ops>. Previously it was erroneously treated like string C<eval>. |
| 924 | |
| 925 | =item * |
| 926 | |
| 927 | In 5.10.0, the two characters C<[~> were sometimes parsed as the smart |
| 928 | match operator (C<~~>) [RT #63854]. |
| 929 | |
| 930 | =item * |
| 931 | |
| 932 | In 5.10.0, the C<*> quantifier in patterns was sometimes treated as |
| 933 | C<{0,32767}> [RT #60034, #60464]. For example, this match would fail: |
| 934 | |
| 935 | ("ab" x 32768) =~ /^(ab)*$/ |
| 936 | |
| 937 | =item * |
| 938 | |
| 939 | C<shmget> was limited to a 32 bit segment size on a 64 bit OS [RT #63924]. |
| 940 | |
| 941 | =item * |
| 942 | |
| 943 | Using C<next> or C<last> to exit a C<given> block no longer produces a |
| 944 | spurious warning like the following: |
| 945 | |
| 946 | Exiting given via last at foo.pl line 123 |
| 947 | |
| 948 | =item * |
| 949 | |
| 950 | On Windows, C<'.\foo'> and C<'..\foo'> were treated differently than |
| 951 | C<'./foo'> and C<'../foo'> by C<do> and C<require> [RT #63492]. |
| 952 | |
| 953 | =item * |
| 954 | |
| 955 | Assigning a format to a glob could corrupt the format; e.g.: |
| 956 | |
| 957 | *bar=*foo{FORMAT}; # foo format now bad |
| 958 | |
| 959 | =item * |
| 960 | |
| 961 | Attempting to coerce a typeglob to a string or number could cause an |
| 962 | assertion failure. The correct error message is now generated, |
| 963 | C<Can't coerce GLOB to I<$type>>. |
| 964 | |
| 965 | =item * |
| 966 | |
| 967 | Under C<use filetest 'access'>, C<-x> was using the wrong access mode. This |
| 968 | has been fixed [RT #49003]. |
| 969 | |
| 970 | =item * |
| 971 | |
| 972 | C<length> on a tied scalar that returned a Unicode value would not be |
| 973 | correct the first time. This has been fixed. |
| 974 | |
| 975 | =item * |
| 976 | |
| 977 | Using an array C<tie> inside in array C<tie> could SEGV. This has been |
| 978 | fixed. [RT #51636] |
| 979 | |
| 980 | =item * |
| 981 | |
| 982 | A race condition inside C<PerlIOStdio_close()> has been identified and |
| 983 | fixed. This used to cause various threading issues, including SEGVs. |
| 984 | |
| 985 | =item * |
| 986 | |
| 987 | In C<unpack>, the use of C<()> groups in scalar context was internally |
| 988 | placing a list on the interpreter's stack, which manifested in various |
| 989 | ways, including SEGVs. This is now fixed [RT #50256]. |
| 990 | |
| 991 | =item * |
| 992 | |
| 993 | Magic was called twice in C<substr>, C<\&$x>, C<tie $x, $m> and C<chop>. |
| 994 | These have all been fixed. |
| 995 | |
| 996 | =item * |
| 997 | |
| 998 | A 5.10.0 optimisation to clear the temporary stack within the implicit |
| 999 | loop of C<s///ge> has been reverted, as it turned out to be the cause of |
| 1000 | obscure bugs in seemingly unrelated parts of the interpreter [commit |
| 1001 | ef0d4e17921ee3de]. |
| 1002 | |
| 1003 | =item * |
| 1004 | |
| 1005 | The line numbers for warnings inside C<elsif> are now correct. |
| 1006 | |
| 1007 | =item * |
| 1008 | |
| 1009 | The C<..> operator now works correctly with ranges whose ends are at or |
| 1010 | close to the values of the smallest and largest integers. |
| 1011 | |
| 1012 | =item * |
| 1013 | |
| 1014 | C<binmode STDIN, ':raw'> could lead to segmentation faults on some platforms. |
| 1015 | This has been fixed [RT #54828]. |
| 1016 | |
| 1017 | =item * |
| 1018 | |
| 1019 | An off-by-one error meant that C<index $str, ...> was effectively being |
| 1020 | executed as C<index "$str\0", ...>. This has been fixed [RT #53746]. |
| 1021 | |
| 1022 | =item * |
| 1023 | |
| 1024 | Various leaks associated with named captures in regexes have been fixed |
| 1025 | [RT #57024]. |
| 1026 | |
| 1027 | =item * |
| 1028 | |
| 1029 | A weak reference to a hash would leak. This was affecting C<DBI> |
| 1030 | [RT #56908]. |
| 1031 | |
| 1032 | =item * |
| 1033 | |
| 1034 | Using (?|) in a regex could cause a segfault [RT #59734]. |
| 1035 | |
| 1036 | =item * |
| 1037 | |
| 1038 | Use of a UTF-8 C<tr//> within a closure could cause a segfault [RT #61520]. |
| 1039 | |
| 1040 | =item * |
| 1041 | |
| 1042 | Calling C<Perl_sv_chop()> or otherwise upgrading an SV could result in an |
| 1043 | unaligned 64-bit access on the SPARC architecture [RT #60574]. |
| 1044 | |
| 1045 | =item * |
| 1046 | |
| 1047 | In the 5.10.0 release, C<inc_version_list> would incorrectly list |
| 1048 | C<5.10.*> after C<5.8.*>; this affected the C<@INC> search order |
| 1049 | [RT #67628]. |
| 1050 | |
| 1051 | =item * |
| 1052 | |
| 1053 | In 5.10.0, C<pack "a*", $tainted_value> returned a non-tainted value |
| 1054 | [RT #52552]. |
| 1055 | |
| 1056 | =item * |
| 1057 | |
| 1058 | In 5.10.0, C<printf> and C<sprintf> could produce the fatal error |
| 1059 | C<panic: utf8_mg_pos_cache_update> when printing UTF-8 strings |
| 1060 | [RT #62666]. |
| 1061 | |
| 1062 | =item * |
| 1063 | |
| 1064 | In the 5.10.0 release, a dynamically created C<AUTOLOAD> method might be |
| 1065 | missed (method cache issue) [RT #60220,60232]. |
| 1066 | |
| 1067 | =item * |
| 1068 | |
| 1069 | In the 5.10.0 release, a combination of C<use feature> and C<//ee> could |
| 1070 | cause a memory leak [RT #63110]. |
| 1071 | |
| 1072 | =item * |
| 1073 | |
| 1074 | C<-C> on the shebang (C<#!>) line is once more permitted if it is also |
| 1075 | specified on the command line. C<-C> on the shebang line used to be a |
| 1076 | silent no-op I<if> it was not also on the command line, so perl 5.10.0 |
| 1077 | disallowed it, which broke some scripts. Now perl checks whether it is |
| 1078 | also on the command line and only dies if it is not [RT #67880]. |
| 1079 | |
| 1080 | =item * |
| 1081 | |
| 1082 | In 5.10.0, certain types of re-entrant regular expression could crash, |
| 1083 | or cause the following assertion failure [RT #60508]: |
| 1084 | |
| 1085 | Assertion rx->sublen >= (s - rx->subbeg) + i failed |
| 1086 | |
| 1087 | =item * |
| 1088 | |
| 1089 | Previously missing files from Unicode 5.1 Character Database are now included. |
| 1090 | |
| 1091 | =item * |
| 1092 | |
| 1093 | C<TMPDIR> is now honored when opening an anonymous temporary file |
| 1094 | |
| 1095 | =back |
| 1096 | |
| 1097 | =head1 New or Changed Diagnostics |
| 1098 | |
| 1099 | =over 4 |
| 1100 | |
| 1101 | =item C<panic: sv_chop %s> |
| 1102 | |
| 1103 | This new fatal error occurs when the C routine C<Perl_sv_chop()> was |
| 1104 | passed a position that is not within the scalar's string buffer. This |
| 1105 | could be caused by buggy XS code, and at this point recovery is not |
| 1106 | possible. |
| 1107 | |
| 1108 | =item C<Can't locate package %s for the parents of %s> |
| 1109 | |
| 1110 | This warning has been removed. In general, it only got produced in |
| 1111 | conjunction with other warnings, and removing it allowed an ISA lookup |
| 1112 | optimisation to be added. |
| 1113 | |
| 1114 | =item C<v-string in use/require is non-portable> |
| 1115 | |
| 1116 | This warning has been removed. |
| 1117 | |
| 1118 | =item C<Deep recursion on subroutine "%s"> |
| 1119 | |
| 1120 | It is now possible to change the depth threshold for this warning from the |
| 1121 | default of 100, by recompiling the F<perl> binary, setting the C |
| 1122 | pre-processor macro C<PERL_SUB_DEPTH_WARN> to the desired value. |
| 1123 | |
| 1124 | =back |
| 1125 | |
| 1126 | =head1 Changed Internals |
| 1127 | |
| 1128 | =over 4 |
| 1129 | |
| 1130 | =item * |
| 1131 | |
| 1132 | TODO: C<SVt_RV> is gone. RVs are now stored in IVs |
| 1133 | |
| 1134 | =item * |
| 1135 | |
| 1136 | TODO: REGEXPs are first class |
| 1137 | |
| 1138 | =item * |
| 1139 | |
| 1140 | TODO: OOK is reworked, such that an OOKed scalar is PV not PVIV |
| 1141 | |
| 1142 | =item * |
| 1143 | |
| 1144 | The J.R.R. Tolkien quotes at the head of C source file have been checked and |
| 1145 | proper citations added, thanks to a patch from Tom Christiansen. |
| 1146 | |
| 1147 | =item * |
| 1148 | |
| 1149 | C<Perl_vcroak()> now accepts a null first argument. In addition, a full audit |
| 1150 | was made of the "not NULL" compiler annotations, and those for several |
| 1151 | other internal functions were corrected. |
| 1152 | |
| 1153 | =item * |
| 1154 | |
| 1155 | New macros C<dSAVEDERRNO>, C<dSAVE_ERRNO>, C<SAVE_ERRNO>, C<RESTORE_ERRNO> |
| 1156 | have been added to formalise the temporary saving of the C<errno> |
| 1157 | variable. |
| 1158 | |
| 1159 | =item * |
| 1160 | |
| 1161 | The function C<Perl_sv_insert_flags> has been added to augment |
| 1162 | C<Perl_sv_insert>. |
| 1163 | |
| 1164 | =item * |
| 1165 | |
| 1166 | The function C<Perl_newSV_type(type)> has been added, equivalent to |
| 1167 | C<Perl_newSV()> followed by C<Perl_sv_upgrade(type)>. |
| 1168 | |
| 1169 | =item * |
| 1170 | |
| 1171 | The function C<Perl_newSVpvn_flags()> has been added, equivalent to |
| 1172 | C<Perl_newSVpvn()> and then performing the action relevant to the flag. |
| 1173 | |
| 1174 | Two flag bits are currently supported. |
| 1175 | |
| 1176 | =over 4 |
| 1177 | |
| 1178 | =item C<SVf_UTF8> |
| 1179 | |
| 1180 | This will call C<SvUTF8_on()> for you. (Note that this does not convert an |
| 1181 | sequence of ISO 8859-1 characters to UTF-8). A wrapper, C<newSVpvn_utf8()> |
| 1182 | is available for this. |
| 1183 | |
| 1184 | =item C<SVs_TEMP> |
| 1185 | |
| 1186 | Call C<Perl_sv_2mortal()> on the new SV. |
| 1187 | |
| 1188 | =back |
| 1189 | |
| 1190 | There is also a wrapper that takes constant strings, C<newSVpvs_flags()>. |
| 1191 | |
| 1192 | =item * |
| 1193 | |
| 1194 | The function C<Perl_croak_xs_usage> has been added as a wrapper to |
| 1195 | C<Perl_croak>. |
| 1196 | |
| 1197 | =item * |
| 1198 | |
| 1199 | The functions C<PerlIO_find_layer> and C<PerlIO_list_alloc> are now |
| 1200 | exported. |
| 1201 | |
| 1202 | =item * |
| 1203 | |
| 1204 | C<PL_na> has been exterminated from the core code, replaced by local STRLEN |
| 1205 | temporaries, or C<*_nolen()> calls. Either approach is faster than C<PL_na>, |
| 1206 | which is a pointer deference into the interpreter structure under ithreads, |
| 1207 | and a global variable otherwise. |
| 1208 | |
| 1209 | =item * |
| 1210 | |
| 1211 | C<Perl_mg_free()> used to leave freed memory accessible via C<SvMAGIC()> on |
| 1212 | the scalar. It now updates the linked list to remove each piece of magic |
| 1213 | as it is freed. |
| 1214 | |
| 1215 | =item * |
| 1216 | |
| 1217 | Under ithreads, the regex in C<PL_reg_curpm> is now reference counted. This |
| 1218 | eliminates a lot of hackish workarounds to cope with it not being reference |
| 1219 | counted. |
| 1220 | |
| 1221 | =item * |
| 1222 | |
| 1223 | C<Perl_mg_magical()> would sometimes incorrectly turn on C<SvRMAGICAL()>. |
| 1224 | This has been fixed. |
| 1225 | |
| 1226 | =item * |
| 1227 | |
| 1228 | The I<public> IV and NV flags are now not set if the string value has |
| 1229 | trailing "garbage". This behaviour is consistent with not setting the |
| 1230 | public IV or NV flags if the value is out of range for the type. |
| 1231 | |
| 1232 | =item * |
| 1233 | |
| 1234 | SV allocation tracing has been added to the diagnostics enabled by C<-Dm>. |
| 1235 | The tracing can alternatively output via the C<PERL_MEM_LOG> mechanism, if |
| 1236 | that was enabled when the F<perl> binary was compiled. |
| 1237 | |
| 1238 | =item * |
| 1239 | |
| 1240 | Smartmatch resolution tracing has been added as a new diagnostic. Use C<-DM> to |
| 1241 | enable it. |
| 1242 | |
| 1243 | |
| 1244 | =item * |
| 1245 | |
| 1246 | A new debugging flag C<-DB> now dumps subroutine definitions, leaving |
| 1247 | C<-Dx> for its original purpose of dumping syntax trees. |
| 1248 | |
| 1249 | =item * |
| 1250 | |
| 1251 | Uses of C<Nullav>, C<Nullcv>, C<Nullhv>, C<Nullop>, C<Nullsv> etc have been |
| 1252 | replaced by C<NULL> in the core code, and non-dual-life modules, as C<NULL> |
| 1253 | is clearer to those unfamiliar with the core code. |
| 1254 | |
| 1255 | =item * |
| 1256 | |
| 1257 | A macro C<MUTABLE_PTR(p)> has been added, which on (non-pedantic) gcc will |
| 1258 | not cast away C<const>, returning a C<void *>. Macros C<MUTABLE_SV(av)>, |
| 1259 | C<MUTABLE_SV(cv)> etc build on this, casting to C<AV *> etc without |
| 1260 | casting away C<const>. This allows proper compile-time auditing of |
| 1261 | C<const> correctness in the core, and helped picked up some errors (now |
| 1262 | fixed). |
| 1263 | |
| 1264 | =item * |
| 1265 | |
| 1266 | Macros C<mPUSHs()> and C<mXPUSHs()> have been added, for pushing SVs on the |
| 1267 | stack and mortalizing them. |
| 1268 | |
| 1269 | =item * |
| 1270 | |
| 1271 | Use of the private structure C<mro_meta> has changed slightly. Nothing |
| 1272 | outside the core should be accessing this directly anyway. |
| 1273 | |
| 1274 | =item * |
| 1275 | |
| 1276 | A new tool, F<Porting/expand-macro.pl> has been added, that allows you |
| 1277 | to view how a C preprocessor macro would be expanded when compiled. |
| 1278 | This is handy when trying to decode the macro hell that is the perl |
| 1279 | guts. |
| 1280 | |
| 1281 | =back |
| 1282 | |
| 1283 | =head1 New Tests |
| 1284 | |
| 1285 | Many modules updated from CPAN incorporate new tests. |
| 1286 | |
| 1287 | Several tests that have the potential to hang forever if they fail now |
| 1288 | incorporate a "watchdog" functionality that will kill them after a timeout, |
| 1289 | which helps ensure that C<make test> and C<make test_harness> run to |
| 1290 | completion automatically. (Jerry Hedden). |
| 1291 | |
| 1292 | Some core-specific tests have been added: |
| 1293 | |
| 1294 | =over 4 |
| 1295 | |
| 1296 | =item t/comp/retainedlines.t |
| 1297 | |
| 1298 | Check that the debugger can retain source lines from C<eval>. |
| 1299 | |
| 1300 | =item t/io/perlio_fail.t |
| 1301 | |
| 1302 | Check that bad layers fail. |
| 1303 | |
| 1304 | =item t/io/perlio_leaks.t |
| 1305 | |
| 1306 | Check that PerlIO layers are not leaking. |
| 1307 | |
| 1308 | =item t/io/perlio_open.t |
| 1309 | |
| 1310 | Check that certain special forms of open work. |
| 1311 | |
| 1312 | =item t/io/perlio.t |
| 1313 | |
| 1314 | General PerlIO tests. |
| 1315 | |
| 1316 | =item t/io/pvbm.t |
| 1317 | |
| 1318 | Check that there is no unexpected interaction between the internal types |
| 1319 | C<PVBM> and C<PVGV>. |
| 1320 | |
| 1321 | =item t/mro/package_aliases.t |
| 1322 | |
| 1323 | Check that mro works properly in the presence of aliased packages. |
| 1324 | |
| 1325 | =item t/op/dbm.t |
| 1326 | |
| 1327 | Tests for C<dbmopen> and C<dbmclose>. |
| 1328 | |
| 1329 | =item t/op/index_thr.t |
| 1330 | |
| 1331 | Tests for the interaction of C<index> and threads. |
| 1332 | |
| 1333 | =item t/op/pat_thr.t |
| 1334 | |
| 1335 | Tests for the interaction of esoteric patterns and threads. |
| 1336 | |
| 1337 | =item t/op/qr_gc.t |
| 1338 | |
| 1339 | Test that C<qr> doesn't leak. |
| 1340 | |
| 1341 | =item t/op/reg_email_thr.t |
| 1342 | |
| 1343 | Tests for the interaction of regex recursion and threads. |
| 1344 | |
| 1345 | =item t/op/regexp_qr_embed_thr.t |
| 1346 | |
| 1347 | Tests for the interaction of patterns with embedded C<qr//> and threads. |
| 1348 | |
| 1349 | =item t/op/regexp_unicode_prop.t |
| 1350 | |
| 1351 | Tests for Unicode properties in regular expressions. |
| 1352 | |
| 1353 | =item t/op/regexp_unicode_prop_thr.t |
| 1354 | |
| 1355 | Tests for the interaction of Unicode properties and threads. |
| 1356 | |
| 1357 | =item t/op/reg_nc_tie.t |
| 1358 | |
| 1359 | Test the tied methods of C<Tie::Hash::NamedCapture>. |
| 1360 | |
| 1361 | =item t/op/reg_posixcc.t |
| 1362 | |
| 1363 | Check that POSIX character classes behave consistently. |
| 1364 | |
| 1365 | =item t/op/re.t |
| 1366 | |
| 1367 | Check that exportable C<re> functions in F<universal.c> work. |
| 1368 | |
| 1369 | =item t/op/setpgrpstack.t |
| 1370 | |
| 1371 | Check that C<setpgrp> works. |
| 1372 | |
| 1373 | =item t/op/substr_thr.t |
| 1374 | |
| 1375 | Tests for the interaction of C<substr> and threads. |
| 1376 | |
| 1377 | =item t/op/upgrade.t |
| 1378 | |
| 1379 | Check that upgrading and assigning scalars works. |
| 1380 | |
| 1381 | =item t/uni/lex_utf8.t |
| 1382 | |
| 1383 | Check that Unicode in the lexer works. |
| 1384 | |
| 1385 | =item t/uni/tie.t |
| 1386 | |
| 1387 | Check that Unicode and C<tie> work. |
| 1388 | |
| 1389 | =back |
| 1390 | |
| 1391 | =head1 Known Problems |
| 1392 | |
| 1393 | This is a list of some significant unfixed bugs, which are regressions |
| 1394 | from either 5.10.0 or 5.8.x. |
| 1395 | |
| 1396 | =over 4 |
| 1397 | |
| 1398 | =item * |
| 1399 | |
| 1400 | C<List::Util::first> misbehaves in the presence of a lexical C<$_> |
| 1401 | (typically introduced by C<my $_> or implicitly by C<given>). The variable |
| 1402 | which gets set for each iteration is the package variable C<$_>, not the |
| 1403 | lexical C<$_> [RT #67694]. |
| 1404 | |
| 1405 | A similar issue may occur in other modules that provide functions which |
| 1406 | take a block as their first argument, like |
| 1407 | |
| 1408 | foo { ... $_ ...} list |
| 1409 | |
| 1410 | =item * |
| 1411 | |
| 1412 | The C<charnames> pragma may generate a run-time error when a regex is |
| 1413 | interpolated [RT #56444]: |
| 1414 | |
| 1415 | use charnames ':full'; |
| 1416 | my $r1 = qr/\N{THAI CHARACTER SARA I}/; |
| 1417 | "foo" =~ $r1; # okay |
| 1418 | "foo" =~ /$r1+/; # runtime error |
| 1419 | |
| 1420 | A workaround is to generate the character outside of the regex: |
| 1421 | |
| 1422 | my $a = "\N{THAI CHARACTER SARA I}"; |
| 1423 | my $r1 = qr/$a/; |
| 1424 | |
| 1425 | =item * |
| 1426 | |
| 1427 | Some regexes may run much more slowly when run in a child thread compared |
| 1428 | with the thread the pattern was compiled into [RT #55600]. |
| 1429 | |
| 1430 | =back |
| 1431 | |
| 1432 | =head1 Deprecations |
| 1433 | |
| 1434 | The following items are now deprecated. |
| 1435 | |
| 1436 | =over 4 |
| 1437 | |
| 1438 | =item * |
| 1439 | |
| 1440 | C<Switch> is buggy and should be avoided. From perl 5.11.0 onwards, it is |
| 1441 | intended that any use of the core version of this module will emit a |
| 1442 | warning, and that the module will eventually be removed from the core |
| 1443 | (probably in perl 5.14.0). See L<perlsyn/"Switch statements"> for its |
| 1444 | replacement. |
| 1445 | |
| 1446 | =item * |
| 1447 | |
| 1448 | The following modules will be removed from the core distribution in a future |
| 1449 | release, and should be installed from CPAN instead. Distributions on CPAN |
| 1450 | which require these should add them to their prerequisites. The core versions |
| 1451 | of these modules warnings will issue a deprecation warning. |
| 1452 | |
| 1453 | =over |
| 1454 | |
| 1455 | =item * |
| 1456 | |
| 1457 | C<Class::ISA> |
| 1458 | |
| 1459 | =item * |
| 1460 | |
| 1461 | C<Pod::Plainer> |
| 1462 | |
| 1463 | =item * |
| 1464 | |
| 1465 | C<Shell> |
| 1466 | |
| 1467 | =back |
| 1468 | |
| 1469 | Currently support to install from CPAN without a I<force> is C<TODO> in CPAN |
| 1470 | and CPANPLUS. This will be addressed before 5.12.0 ships. |
| 1471 | |
| 1472 | =item * |
| 1473 | |
| 1474 | C<suidperl> has been removed. It used to provide a mechanism to |
| 1475 | emulate setuid permission bits on systems that don't support it properly. |
| 1476 | |
| 1477 | =item * |
| 1478 | |
| 1479 | Deprecate assignment to $[ |
| 1480 | |
| 1481 | =item * |
| 1482 | |
| 1483 | Remove attrs, which has been deprecated since 1999/10/02. |
| 1484 | |
| 1485 | =item * |
| 1486 | |
| 1487 | Deprecate use of the attribute :locked on subroutines. |
| 1488 | |
| 1489 | =item * |
| 1490 | |
| 1491 | Deprecate using "locked" with the attributes pragma. |
| 1492 | |
| 1493 | =item * |
| 1494 | |
| 1495 | Deprecate using "unique" with the attributes pragma. |
| 1496 | |
| 1497 | =item * |
| 1498 | |
| 1499 | warn if ++ or -- are unable to change the value because it's beyond the limit of representation |
| 1500 | |
| 1501 | This uses a new warnings category: "imprecision". |
| 1502 | |
| 1503 | =item * |
| 1504 | |
| 1505 | Make lc/uc/lcfirst/ucfirst warn when passed undef. |
| 1506 | |
| 1507 | =item * |
| 1508 | |
| 1509 | Show constant in "Useless use of a constant in void context" |
| 1510 | |
| 1511 | =item * |
| 1512 | |
| 1513 | Make the new warning report undef constants as undef |
| 1514 | |
| 1515 | =item * |
| 1516 | |
| 1517 | Add a new warning, "Prototype after '%s'" |
| 1518 | |
| 1519 | =item * |
| 1520 | |
| 1521 | Tweak the "Illegal character in prototype" warning so it's more precise when reporting illegal characters after _ |
| 1522 | |
| 1523 | =item * |
| 1524 | |
| 1525 | Unintended interpolation of $\ in regex |
| 1526 | |
| 1527 | =item * |
| 1528 | |
| 1529 | Make overflow warnings in gmtime/localtime only occur when warnings are on |
| 1530 | |
| 1531 | =item * |
| 1532 | |
| 1533 | Improve mro merging error messages. |
| 1534 | |
| 1535 | They are now very similar to those produced by Algorithm::C3. |
| 1536 | |
| 1537 | =item * |
| 1538 | |
| 1539 | Amelioration of the error message "Unrecognized character %s in column %d" |
| 1540 | |
| 1541 | Changes the error message to "Unrecognized character %s; marked by E<lt>-- |
| 1542 | HERE after %sE<lt>-- HERE near column %d". This should make it a little |
| 1543 | simpler to spot and correct the suspicious character. |
| 1544 | |
| 1545 | =item * |
| 1546 | |
| 1547 | Explicitely point to $. when it causes an uninitialized warning for ranges in scalar context |
| 1548 | |
| 1549 | |
| 1550 | =item * |
| 1551 | |
| 1552 | Deprecated numerous Perl 4-era libraries: |
| 1553 | |
| 1554 | F<termcap.pl>, F<tainted.pl>, F<stat.pl>, F<shellwords.pl>, F<pwd.pl>, |
| 1555 | F<open3.pl>, F<open2.pl>, F<newgetopt.pl>, F<look.pl>, F<find.pl>, |
| 1556 | F<finddepth.pl>, F<importenv.pl>, F<hostname.pl>, F<getopts.pl>, |
| 1557 | F<getopt.pl>, F<getcwd.pl>, F<flush.pl>, F<fastcwd.pl>, F<exceptions.pl>, |
| 1558 | F<ctime.pl>, F<complete.pl>, F<cacheout.pl>, F<bigrat.pl>, F<bigint.pl>, |
| 1559 | F<bigfloat.pl>, F<assert.pl>, F<abbrev.pl>, F<dotsh.pl>, and |
| 1560 | F<timelocal.pl> are all now deprecated. Using them will incur a warning. |
| 1561 | |
| 1562 | =back |
| 1563 | |
| 1564 | =head1 Acknowledgements |
| 1565 | |
| 1566 | Some of the work in this release was funded by a TPF grant funded by |
| 1567 | Dijkmat BV, The Netherlands. |
| 1568 | |
| 1569 | Steffen Mueller and David Golden in particular helped getting CPAN modules |
| 1570 | polished and synchronised with their in-core equivalents. |
| 1571 | |
| 1572 | Craig Berry was tireless in getting maint to run under VMS, no matter how |
| 1573 | many times we broke it for him. |
| 1574 | |
| 1575 | The other core committers contributed most of the changes, and applied most |
| 1576 | of the patches sent in by the hundreds of contributors listed in F<AUTHORS>. |
| 1577 | |
| 1578 | Much of the work of categorizing changes in this perldelta file was contributed |
| 1579 | by the following porters using changelogger.bestpractical.com: |
| 1580 | |
| 1581 | Nicholas Clark, leon, shawn, alexm, rjbs, rafl, Pedro Melo, brunorc, |
| 1582 | anonymous, ☄, Tom Hukins, anonymous, Jesse, dagolden, Moritz Onken, |
| 1583 | Mark Fowler, chorny, anonymous, tmtm |
| 1584 | |
| 1585 | Finally, thanks to Larry Wall, without whom none of this would be |
| 1586 | necessary. |
| 1587 | |
| 1588 | =head1 Reporting Bugs |
| 1589 | |
| 1590 | If you find what you think is a bug, you might check the articles |
| 1591 | recently posted to the comp.lang.perl.misc newsgroup and the perl |
| 1592 | bug database at http://rt.perl.org/perlbug/ . There may also be |
| 1593 | information at http://www.perl.org/ , the Perl Home Page. |
| 1594 | |
| 1595 | If you believe you have an unreported bug, please run the B<perlbug> |
| 1596 | program included with your release. Be sure to trim your bug down |
| 1597 | to a tiny but sufficient test case. Your bug report, along with the |
| 1598 | output of C<perl -V>, will be sent off to perlbug@perl.org to be |
| 1599 | analysed by the Perl porting team. |
| 1600 | |
| 1601 | If the bug you are reporting has security implications, which make it |
| 1602 | inappropriate to send to a publicly archived mailing list, then please send |
| 1603 | it to perl5-security-report@perl.org. This points to a closed subscription |
| 1604 | unarchived mailing list, which includes all the core committers, who be able |
| 1605 | to help assess the impact of issues, figure out a resolution, and help |
| 1606 | co-ordinate the release of patches to mitigate or fix the problem across all |
| 1607 | platforms on which Perl is supported. Please only use this address for |
| 1608 | security issues in the Perl core, not for modules independently |
| 1609 | distributed on CPAN. |
| 1610 | |
| 1611 | =head1 SEE ALSO |
| 1612 | |
| 1613 | The F<Changes> file for an explanation of how to view exhaustive details |
| 1614 | on what changed. |
| 1615 | |
| 1616 | The F<INSTALL> file for how to build Perl. |
| 1617 | |
| 1618 | The F<README> file for general stuff. |
| 1619 | |
| 1620 | The F<Artistic> and F<Copying> files for copyright information. |
| 1621 | |
| 1622 | =cut |
| 1623 | |
| 1624 | |