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1 | =head1 NAME |
2 | |
3 | perl571delta - what's new for perl v5.7.2 |
4 | |
5 | =head1 DESCRIPTION |
6 | |
7 | This document describes differences between the 5.7.1 release and the |
8 | 5.7.2 release. |
9 | |
10 | (To view the differences between the 5.6.0 release and the 5.7.0 |
11 | release, see L<perl570delta>. To view the differences between the |
12 | 5.7.0 release and the 5.7.1 release, see L<perl571delta>.) |
13 | |
14 | =head1 Security Vulnerability Closed |
15 | |
16 | (This change was already made in 5.7.0 but bears repeating here.) |
17 | |
18 | A security vulnerability affecting all Perl versions prior to 5.6.1 |
19 | was found in August 2000. The vulnerability does not affect default |
20 | installations and as far as is known affects only the Linux platform. |
21 | |
22 | You should upgrade your Perl to 5.6.1 as soon as possible. Patches |
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23 | for earlier releases exist but using the patches require full |
24 | recompilation from the source code anyway, so 5.6.1 is your best |
25 | choice. |
26 | |
43d4bbc8 |
27 | See http://www.cpan.org/src/5.0/sperl-2000-08-05/sperl-2000-08-05.txt |
28 | for more information. |
29 | |
30 | =head1 Incompatible Changes |
31 | |
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32 | If your pointers are 64 bits wide, the Perl malloc is no more being |
33 | used because it simply does not work with 8-byte pointers. Also, |
34 | usually the system malloc on such platforms are much better optimized |
35 | for such large memory models than the Perl malloc. |
36 | |
cbb3fa72 |
37 | =head1 Future Deprecations |
38 | |
39 | The current user-visible implementation of pseudo-hashes (the weird |
40 | use of the first array element) is deprecated starting from Perl 5.8.0 |
41 | and will be removed in Perl 5.10.0, and the feature will be implemented |
42 | differently. Not only is the current interface rather ugly, but the |
43 | current implementation slows down normal array and hash use quite |
44 | noticeably. The 'fields' pragma interface will remain available. |
45 | |
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46 | The suidperl is also considered to be too much a risk to continue |
47 | maintaining and the suidperl code is likely to be removed in a future |
48 | release. |
49 | |
43d4bbc8 |
50 | =head1 Core Enhancements |
51 | |
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52 | In general a lot of fixing has happened in the area of Perl's understanding |
53 | of numbers, both integer and floating point. Since in many systems the |
54 | standard number parsing functions like C<strtoul()> and C<atof()> seem |
55 | to have bugs, Perl tries to work around their deficiencies. This results |
56 | hopefully in more accurate numbers. |
57 | |
58 | =over 4 |
59 | |
60 | =item * |
61 | |
62 | The rules for allowing underscores (underbars) in numeric constants |
63 | have been relaxed and simplified: now you can have an underscore |
64 | B<between digits>. |
65 | |
66 | =item * |
67 | |
68 | VMS now works under PerlIO. |
69 | |
70 | =item * |
71 | |
72 | GMAGIC (right-hand side magic) could in many cases such as concatenation |
73 | of string be invoked too many times. |
74 | |
75 | =item * |
76 | |
77 | The MAGIC constants (e.g. C<'P'>) have been macrofied |
78 | (e.g. C<PERL_MAGIC_TIED>) for better source code readability |
79 | and maintainability. |
80 | |
81 | =item * |
82 | |
83 | The C<op_clear> and C<op_null> are now exported. |
84 | |
85 | =item * |
86 | |
87 | The Perl parser has been stress tested using both random input and |
88 | Markov chain input. |
89 | |
90 | =back |
91 | |
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92 | =head1 Modules and Pragmata |
93 | |
94 | =head2 New Modules |
95 | |
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96 | =over 4 |
97 | |
98 | =item * |
99 | |
100 | Attribute::Handlers - Simpler definition of attribute handlers |
101 | |
102 | =item * |
103 | |
104 | ExtUtils::Constant - generate XS code to import C header constants |
105 | |
106 | =item * |
107 | |
108 | I18N::LangTags - functions for dealing with RFC3066-style language tags |
109 | |
110 | =item * |
111 | |
112 | List::Util - selection of general-utility list subroutines |
113 | |
114 | =item * |
115 | |
116 | Locale::Maketext - framework for localization |
117 | |
118 | =item * |
119 | |
120 | NEXT - pseudo-class for method redispatch |
121 | |
122 | =item * |
123 | |
124 | Scalar::Util - selection of general-utility scalar subroutines |
125 | |
126 | =item * |
127 | |
128 | Time::HiRes - high resolution ualarm, usleep, and gettimeofday |
129 | |
130 | =back |
131 | |
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132 | =head2 Updated And Improved Modules and Pragmata |
133 | |
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134 | =over 4 |
135 | |
136 | =item * |
137 | |
138 | L<B::Deparse> module has been significantly enhanced. It now |
139 | can deparse almost all of the standard test suite (so that the |
140 | tests still succeed). |
141 | |
142 | =item * |
143 | |
144 | L<Class::Struct> now assigns the array/hash element if the accessor |
145 | is called with an array/hash element as the B<sole> argument. |
146 | |
147 | =item * |
148 | |
149 | L<Cwd> extension is now (even) faster. |
150 | |
151 | =item * |
152 | |
153 | L<DB_File> extension has been updated to version 1.77. |
154 | |
155 | =item * |
156 | |
157 | L<Fcntl>, L<Socket>, and L<Sys::Syslog> have been rewritten to use the |
158 | new-style constant dispatch section (see L<ExtUtils::Constant>). |
159 | |
160 | =item * |
161 | |
162 | L<File::Glob> now supports C<GLOB_LIMIT> constant to limit the |
163 | size of the returned list of filenames. |
164 | |
165 | =back |
166 | |
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167 | =head1 Performance Enhancements |
168 | |
169 | =head1 Utility Changes |
170 | |
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171 | =over 4 |
172 | |
173 | =item * |
174 | |
175 | L<h2xs> uses the new L<ExtUtils::Constant> module which will affect |
176 | newly created extensions that define constants. Since the new code is |
177 | more correct (if you have two constants where the first one is a |
178 | prefix of the second one, the first constant B<never> gets defined), |
179 | less lossy (it uses integers for integer constant, as opposed to the |
180 | old code that used floating point numbers even for integer constants), |
181 | and slightly faster, you might want to consider regenerating your |
182 | extension code (the new scheme makes regenerating easy). |
183 | |
184 | =item * |
185 | |
186 | The F<emacs/e2ctags.pl> is now much faster. |
187 | |
188 | =item * |
189 | |
190 | The F<Pod::Html> (and thusly L<pod2html>) now allows specifying |
191 | a cache directory. |
192 | |
193 | =back |
194 | |
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195 | =head1 New Documentation |
196 | |
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197 | =over 4 |
198 | |
199 | =item * |
200 | |
201 | L<Locale::Maketext::TPJ13> is an article about software localization, |
202 | originally published in The Perl Journal #13, republished here with |
203 | kind permission. |
204 | |
205 | =item * |
206 | |
207 | More README.$PLATFORM files have been converted into pod, which also |
208 | means that they also be installed as perl$PLATFORM documentation |
209 | files. The new files are L<perlapollo>, L<perlbeos>, L<perldgux>, |
210 | L<perlhurd>, L<perlmint>, L<perlplan9>, L<perlqnx>, and L<perltru64>. |
211 | |
212 | =item * |
213 | |
214 | The F<Todo> and F<Todo-5.6> files have been merged into L<perltodo>. |
215 | |
216 | =item * |
217 | |
218 | Use of the F<gprof> tool to profile Perl has been documented in L<perlhack>. |
219 | |
220 | =back |
221 | |
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222 | =head1 Installation and Configuration Improvements |
223 | |
224 | =head2 New Or Improved Platforms |
225 | |
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226 | =over 4 |
227 | |
228 | =item * |
229 | |
230 | AIX should now work better with gcc. Also longdouble support in |
231 | AIX should be better now. |
232 | |
233 | =item * |
234 | |
235 | AtheOS (http://www.atheos.cx/) is a new platform. |
236 | |
237 | =item * |
238 | |
239 | DG/UX platform now supports the 5.005-style threads. |
240 | |
241 | =item * |
242 | |
243 | MacOS (Classic) [HOPEFULLY] |
244 | |
245 | =item * |
246 | |
247 | MacOS X (or Darwin) should now be able to build Perl even on HFS+ filesystem. |
248 | (The case-insensitivity confused the Perl build process.) |
249 | |
250 | =item * |
251 | |
252 | Netware [HOPEFULLY] |
253 | |
254 | =item * |
255 | |
256 | The Amdahl UTS UNIX mainframe platform is now supported. |
257 | |
258 | =back |
259 | |
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260 | =head2 Generic Improvements |
261 | |
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262 | =over 4 |
263 | |
264 | =item * |
265 | |
266 | The C code has been made much more C<gcc -Wall> clean. Some warning |
267 | messages still remain, though, so if you are compiling with gcc you |
268 | will see some warnings about dubious practices. The warnings are |
269 | being worked on. |
270 | |
271 | =item * |
272 | |
273 | In AFS installations one can configure the root of the AFS to be |
274 | somewhere else than the default F</afs> by using the Configure |
275 | parameter C<-Dafsroot=/some/where/else>. |
276 | |
277 | =item * |
278 | |
279 | The version of Berkeley DB used when the Perl (and, presumably, the |
280 | DB_File extension) was built is now available as |
281 | C<@Config{qw(db_version_major db_version_minor db_version_patch)}> |
282 | from Perl and as C<DB_VERSION_MAJOR_CFG DB_VERSION_MINOR_CFG |
283 | DB_VERSION_PATCH_CFG> from C. |
284 | |
285 | =item * |
286 | |
287 | The Thread extension is not built at all under ithreads (C<Configure |
288 | -Duseithreads>) because it wouldn't work anyway (the Thread extension |
289 | requires being Configured with C<-Duse5005threads>). |
290 | |
291 | =item * |
292 | |
293 | The C<B::Deparse> compiler backend has been so significantly improved |
294 | that almost the whole Perl test suite passes after being deparsed. A |
295 | make target has been added to help in further testing: C<make test.deparse>. |
296 | |
297 | =back |
298 | |
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299 | =head1 Selected Bug Fixes |
300 | |
301 | =head2 Platform Specific Changes and Fixes |
302 | |
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303 | =over 4 |
304 | |
305 | =item * |
306 | |
307 | Some versions of glibc have a broken modfl(). This affects builds |
308 | with C<-Duselongdouble>. This version of Perl detects this brokenness |
309 | and has a workaround for it. The glibc release 2.2.2 is known to have |
310 | fixed the modfl() bug. |
311 | |
312 | =back |
313 | |
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314 | =head1 New or Changed Diagnostics |
315 | |
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316 | =over 4 |
317 | |
318 | =item * |
319 | |
320 | In the regular expression diagnostics the C<E<lt>E<lt> HERE> marker |
321 | introduced in 5.7.0 has been changed to be C<E<lt>-- HERE> since too |
322 | many people found the C<E<lt>E<lt>> to be too similar to here-document |
323 | starters. |
324 | |
325 | =item * |
326 | |
327 | If you try to L<perlfunc/pack> a number less than 0 or larger than 255 |
328 | using the C<"C"> format you will get an optional warning. Similarly |
329 | for the C<"c"> format and a number less than -128 or more than 127. |
330 | |
331 | =item * |
332 | |
333 | Certain regex modifiers such as C<(?o)> make sense only if applied to |
334 | the entire regex. You will an optional warning if you try to do otherwise. |
335 | |
336 | =item * |
337 | |
338 | Using arrays or hashes as references (e.g. C<%foo->{bar}> has been |
339 | deprecated for a while. Now you will get an optional warning. |
340 | |
341 | =back |
342 | |
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343 | =head1 Changed Internals |
344 | |
345 | =head2 Regex pre-/post-compilation items matched up |
346 | |
347 | The regex compiler now maintains a structure that identifies nodes in |
348 | the compiled bytecode with the corresponding syntactic features of the |
349 | original regex expression. The information is attached to the new |
350 | C<offsets> member of the C<struct regexp>. See L<perldebguts> for more |
351 | complete information. |
352 | |
353 | =head1 New Tests |
354 | |
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355 | Several new tests have been added, especially for the F<lib> subsection. |
356 | |
357 | =back |
358 | |
359 | The test F<camel-III/vstring> has been merged with F<op/ver>. |
360 | |
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361 | =head1 Known Problems |
362 | |
363 | Note that unlike other sections in this document (which describe |
364 | changes since 5.7.0) this section is cumulative containing known |
365 | problems for all the 5.7 releases. |
366 | |
367 | =head2 AIX vac 5.0.0.0 May Produce Buggy Code For Perl |
368 | |
369 | The AIX C compiler vac version 5.0.0.0 may produce buggy code, |
370 | resulting in few random tests failing, but when the failing tests |
371 | are run by hand, they succeed. We suggest upgrading to at least |
372 | vac version 5.0.1.0, that has been known to compile Perl correctly. |
373 | "lslpp -L|grep vac.C" will tell you the vac version. |
374 | |
375 | =head2 lib/ftmp-security tests warn 'system possibly insecure' |
376 | |
377 | Don't panic. Read INSTALL 'make test' section instead. |
378 | |
379 | =head2 lib/io_multihomed Fails In LP64-Configured HP-UX |
380 | |
381 | The lib/io_multihomed test may hang in HP-UX if Perl has been |
382 | configured to be 64-bit. Because other 64-bit platforms do not hang in |
383 | this test, HP-UX is suspect. All other tests pass in 64-bit HP-UX. The |
384 | test attempts to create and connect to "multihomed" sockets (sockets |
385 | which have multiple IP addresses). |
386 | |
387 | =head2 Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX |
388 | |
389 | If perl is configured with -Duse64bitall, the successful result of the |
390 | subtest 10 of lib/posix may arrive before the successful result of the |
391 | subtest 9, which confuses the test harness so much that it thinks the |
392 | subtest 9 failed. |
393 | |
394 | =head2 lib/b test 19 |
395 | |
396 | The test fails on various platforms (PA64 and IA64 are known), but the |
397 | exact cause is still being investigated. |
398 | |
399 | =head2 Linux With Sfio Fails op/misc Test 48 |
400 | |
401 | No known fix. |
402 | |
403 | =head2 sigaction test 13 in VMS |
404 | |
405 | The test is known to fail; whether it's because of VMS of because |
406 | of faulty test is not known. |
407 | |
408 | =head2 sprintf tests 129 and 130 |
409 | |
410 | The op/sprintf tests 129 and 130 are known to fail on some platforms. |
411 | Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX. |
412 | The failing platforms do not comply with the ANSI C Standard, line |
413 | 19ff on page 134 of ANSI X3.159 1989 to be exact. (They produce |
414 | something else than "1" and "-1" when formatting 0.6 and -0.6 using |
415 | the printf format "%.0f", most often they produce "0" and "-0".) |
416 | |
417 | =head2 Failure of Thread tests |
418 | |
419 | The subtests 19 and 20 of lib/thr5005.t test are known to fail due to |
420 | fundamental problems in the 5.005 threading implementation. These are |
421 | not new failures--Perl 5.005_0x has the same bugs, but didn't have |
422 | these tests. (Note that support for 5.005-style threading remains |
423 | experimental.) |
424 | |
425 | =head2 Localising a Tied Variable Leaks Memory |
426 | |
427 | use Tie::Hash; |
428 | tie my %tie_hash => 'Tie::StdHash'; |
429 | |
430 | ... |
431 | |
432 | local($tie_hash{Foo}) = 1; # leaks |
433 | |
434 | Code like the above is known to leak memory every time the local() |
435 | is executed. |
436 | |
437 | =head2 Self-tying of Arrays and Hashes Is Forbidden |
438 | |
439 | Self-tying of arrays and hashes is broken in rather deep and |
440 | hard-to-fix ways. As a stop-gap measure to avoid people from getting |
441 | frustrated at the mysterious results (core dumps, most often) it is |
442 | for now forbidden (you will get a fatal error even from an attempt). |
443 | |
444 | =head2 Building Extensions Can Fail Because Of Largefiles |
445 | |
446 | Some extensions like mod_perl are known to have issues with |
447 | `largefiles', a change brought by Perl 5.6.0 in which file offsets |
448 | default to 64 bits wide, where supported. Modules may fail to compile |
449 | at all or compile and work incorrectly. Currently there is no good |
450 | solution for the problem, but Configure now provides appropriate |
451 | non-largefile ccflags, ldflags, libswanted, and libs in the %Config |
452 | hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are |
453 | having problems can try configuring themselves without the |
454 | largefileness. This is admittedly not a clean solution, and the |
455 | solution may not even work at all. One potential failure is whether |
456 | one can (or, if one can, whether it's a good idea) link together at |
457 | all binaries with different ideas about file offsets, all this is |
458 | platform-dependent. |
459 | |
460 | =head2 The Compiler Suite Is Still Experimental |
461 | |
462 | The compiler suite is slowly getting better but is nowhere near |
463 | working order yet. |
464 | |
465 | =head1 Reporting Bugs |
466 | |
467 | If you find what you think is a bug, you might check the articles |
468 | recently posted to the comp.lang.perl.misc newsgroup and the perl |
469 | bug database at http://bugs.perl.org. There may also be |
470 | information at http://www.perl.com/perl/, the Perl Home Page. |
471 | |
472 | If you believe you have an unreported bug, please run the B<perlbug> |
473 | program included with your release. Be sure to trim your bug down |
474 | to a tiny but sufficient test case. Your bug report, along with the |
475 | output of C<perl -V>, will be sent off to perlbug@perl.org to be |
476 | analysed by the Perl porting team. |
477 | |
478 | =head1 SEE ALSO |
479 | |
480 | The F<Changes> file for exhaustive details on what changed. |
481 | |
482 | The F<INSTALL> file for how to build Perl. |
483 | |
484 | The F<README> file for general stuff. |
485 | |
486 | The F<Artistic> and F<Copying> files for copyright information. |
487 | |
488 | =head1 HISTORY |
489 | |
490 | Written by Jarkko Hietaniemi <F<jhi@iki.fi>>, with many contributions |
491 | from The Perl Porters and Perl Users submitting feedback and patches. |
492 | |
493 | Send omissions or corrections to <F<perlbug@perl.org>>. |
494 | |
495 | =cut |