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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 | |
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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 | =head2 64-bit platforms and malloc |
33 | |
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34 | If your pointers are 64 bits wide, the Perl malloc is no more being |
35 | used because it simply does not work with 8-byte pointers. Also, |
36 | usually the system malloc on such platforms are much better optimized |
37 | for such large memory models than the Perl malloc. |
38 | |
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39 | =head2 Future Deprecations |
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40 | |
41 | The current user-visible implementation of pseudo-hashes (the weird |
42 | use of the first array element) is deprecated starting from Perl 5.8.0 |
43 | and will be removed in Perl 5.10.0, and the feature will be implemented |
44 | differently. Not only is the current interface rather ugly, but the |
45 | current implementation slows down normal array and hash use quite |
46 | noticeably. The 'fields' pragma interface will remain available. |
47 | |
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48 | The suidperl is also considered to be too much a risk to continue |
49 | maintaining and the suidperl code is likely to be removed in a future |
50 | release. |
51 | |
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52 | =head1 Core Enhancements |
53 | |
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54 | In general a lot of fixing has happened in the area of Perl's understanding |
55 | of numbers, both integer and floating point. Since in many systems the |
56 | standard number parsing functions like C<strtoul()> and C<atof()> seem |
57 | to have bugs, Perl tries to work around their deficiencies. This results |
58 | hopefully in more accurate numbers. |
59 | |
60 | =over 4 |
61 | |
62 | =item * |
63 | |
64 | The rules for allowing underscores (underbars) in numeric constants |
65 | have been relaxed and simplified: now you can have an underscore |
66 | B<between digits>. |
67 | |
68 | =item * |
69 | |
70 | VMS now works under PerlIO. |
71 | |
72 | =item * |
73 | |
74 | GMAGIC (right-hand side magic) could in many cases such as concatenation |
75 | of string be invoked too many times. |
76 | |
77 | =item * |
78 | |
79 | The MAGIC constants (e.g. C<'P'>) have been macrofied |
80 | (e.g. C<PERL_MAGIC_TIED>) for better source code readability |
81 | and maintainability. |
82 | |
83 | =item * |
84 | |
85 | The C<op_clear> and C<op_null> are now exported. |
86 | |
87 | =item * |
88 | |
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89 | L<utime> now supports C<utime undef, undef, @files> to change the |
90 | times to the current time. |
91 | |
92 | =item * |
93 | |
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94 | The Perl parser has been stress tested using both random input and |
95 | Markov chain input. |
96 | |
97 | =back |
98 | |
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99 | =head1 Modules and Pragmata |
100 | |
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101 | =head2 New Modules and Distribution |
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102 | |
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103 | =over 4 |
104 | |
105 | =item * |
106 | |
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107 | L<Attribute::Handlers> - Simpler definition of attribute handlers |
108 | |
109 | =item * |
110 | |
111 | L<ExtUtils::Constant> - generate XS code to import C header constants |
112 | |
113 | =item * |
114 | |
115 | L<I18N::LangTags> - functions for dealing with RFC3066-style language tags |
116 | |
117 | =item * |
118 | |
119 | L<libnet> - a collection of perl5 modules related to network programming |
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120 | |
121 | =item * |
122 | |
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123 | L<List::Util> - selection of general-utility list subroutines |
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124 | |
125 | =item * |
126 | |
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127 | L<Locale::Maketext> - framework for localization |
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128 | |
129 | =item * |
130 | |
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131 | L<Memoize> - Make your functions faster by trading space for time |
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132 | |
133 | =item * |
134 | |
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135 | L<NEXT> - pseudo-class for method redispatch |
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136 | |
137 | =item * |
138 | |
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139 | L<Scalar::Util> - selection of general-utility scalar subroutines |
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140 | |
141 | =item * |
142 | |
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143 | L<Time::HiRes> - high resolution ualarm, usleep, and gettimeofday |
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144 | |
145 | =item * |
146 | |
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147 | L<Time::Piece> - Object Oriented time objects |
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148 | |
149 | =back |
150 | |
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151 | =head2 Updated And Improved Modules and Pragmata |
152 | |
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153 | =over 4 |
154 | |
155 | =item * |
156 | |
157 | L<B::Deparse> module has been significantly enhanced. It now |
158 | can deparse almost all of the standard test suite (so that the |
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159 | tests still succeed). There is a make target "test.deparse" |
160 | for trying this out. |
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161 | |
162 | =item * |
163 | |
164 | L<Class::Struct> now assigns the array/hash element if the accessor |
165 | is called with an array/hash element as the B<sole> argument. |
166 | |
167 | =item * |
168 | |
169 | L<Cwd> extension is now (even) faster. |
170 | |
171 | =item * |
172 | |
173 | L<DB_File> extension has been updated to version 1.77. |
174 | |
175 | =item * |
176 | |
177 | L<Fcntl>, L<Socket>, and L<Sys::Syslog> have been rewritten to use the |
178 | new-style constant dispatch section (see L<ExtUtils::Constant>). |
179 | |
180 | =item * |
181 | |
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182 | L<File::Find> is now (again) reentrant. It also has been made |
183 | more portable. |
184 | |
185 | =item * |
186 | |
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187 | L<File::Glob> now supports C<GLOB_LIMIT> constant to limit the |
188 | size of the returned list of filenames. |
189 | |
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190 | =item * |
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191 | |
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192 | L<vars> now supports declaring qualified variables. |
193 | |
194 | =back |
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195 | |
196 | =head1 Utility Changes |
197 | |
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198 | =over 4 |
199 | |
200 | =item * |
201 | |
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202 | The F<emacs/e2ctags.pl> is now much faster. |
203 | |
204 | =item * |
205 | |
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206 | L<h2xs> uses the new L<ExtUtils::Constant> module which will affect |
207 | newly created extensions that define constants. Since the new code is |
208 | more correct (if you have two constants where the first one is a |
209 | prefix of the second one, the first constant B<never> gets defined), |
210 | less lossy (it uses integers for integer constant, as opposed to the |
211 | old code that used floating point numbers even for integer constants), |
212 | and slightly faster, you might want to consider regenerating your |
213 | extension code (the new scheme makes regenerating easy). |
214 | |
215 | =item * |
216 | |
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217 | L<libnetcfg> has been added to configure the libnet. |
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218 | |
219 | =item * |
220 | |
221 | The F<Pod::Html> (and thusly L<pod2html>) now allows specifying |
222 | a cache directory. |
223 | |
224 | =back |
225 | |
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226 | =head1 New Documentation |
227 | |
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228 | =over 4 |
229 | |
230 | =item * |
231 | |
232 | L<Locale::Maketext::TPJ13> is an article about software localization, |
233 | originally published in The Perl Journal #13, republished here with |
234 | kind permission. |
235 | |
236 | =item * |
237 | |
238 | More README.$PLATFORM files have been converted into pod, which also |
239 | means that they also be installed as perl$PLATFORM documentation |
240 | files. The new files are L<perlapollo>, L<perlbeos>, L<perldgux>, |
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241 | L<perlhurd>, L<perlmint>, L<perlnetware>, L<perlplan9>, L<perlqnx>, |
242 | and L<perltru64>. |
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243 | |
244 | =item * |
245 | |
246 | The F<Todo> and F<Todo-5.6> files have been merged into L<perltodo>. |
247 | |
248 | =item * |
249 | |
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250 | Use of the F<gprof> tool to profile Perl has been documented in |
251 | L<perlhack>. There is a make target "perl.gprof" for generating a |
252 | gprofiled Perl executable. |
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253 | |
254 | =back |
255 | |
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256 | =head1 Installation and Configuration Improvements |
257 | |
258 | =head2 New Or Improved Platforms |
259 | |
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260 | =over 4 |
261 | |
262 | =item * |
263 | |
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264 | AIX should now work better with gcc. Also longdouble support in AIX |
265 | should be better now. See L<perlaix>. |
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266 | |
267 | =item * |
268 | |
269 | AtheOS (http://www.atheos.cx/) is a new platform. |
270 | |
271 | =item * |
272 | |
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273 | DG/UX platform now supports the 5.005-style threads. See L<perldgux>. |
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274 | |
275 | =item * |
276 | |
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277 | Several MacOS (Classic) portability patches have been applied. We |
278 | hope to get a fully working port by 5.8.0. (The remaining problems |
279 | relate to the changed IO model of Perl.) See L<perlmacos>. |
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280 | |
281 | =item * |
282 | |
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283 | MacOS X (or Darwin) should now be able to build Perl even on HFS+ |
284 | filesystems. (The case-insensitivity confused the Perl build process.) |
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285 | |
286 | =item * |
287 | |
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288 | NetWare from Novell is now supported. See L<perlnetware>. |
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289 | |
290 | =item * |
291 | |
292 | The Amdahl UTS UNIX mainframe platform is now supported. |
293 | |
294 | =back |
295 | |
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296 | =head2 Generic Improvements |
297 | |
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298 | =over 4 |
299 | |
300 | =item * |
301 | |
302 | The C code has been made much more C<gcc -Wall> clean. Some warning |
303 | messages still remain, though, so if you are compiling with gcc you |
304 | will see some warnings about dubious practices. The warnings are |
305 | being worked on. |
306 | |
307 | =item * |
308 | |
309 | In AFS installations one can configure the root of the AFS to be |
310 | somewhere else than the default F</afs> by using the Configure |
311 | parameter C<-Dafsroot=/some/where/else>. |
312 | |
313 | =item * |
314 | |
315 | The version of Berkeley DB used when the Perl (and, presumably, the |
316 | DB_File extension) was built is now available as |
317 | C<@Config{qw(db_version_major db_version_minor db_version_patch)}> |
318 | from Perl and as C<DB_VERSION_MAJOR_CFG DB_VERSION_MINOR_CFG |
319 | DB_VERSION_PATCH_CFG> from C. |
320 | |
321 | =item * |
322 | |
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323 | The Thread extension is now not built at all under ithreads |
324 | (C<Configure -Duseithreads>) because it wouldn't work anyway (the |
325 | Thread extension requires being Configured with C<-Duse5005threads>). |
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326 | |
327 | =item * |
328 | |
329 | The C<B::Deparse> compiler backend has been so significantly improved |
330 | that almost the whole Perl test suite passes after being deparsed. A |
331 | make target has been added to help in further testing: C<make test.deparse>. |
332 | |
333 | =back |
334 | |
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335 | =head1 Selected Bug Fixes |
336 | |
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337 | =over 5 |
338 | |
339 | =item * |
340 | |
341 | The autouse pragma didn't work for Multi::Part::Function::Names. |
342 | |
343 | =item * |
344 | |
345 | The behaviour of non-decimal but numeric string constants such as |
346 | "0x23" was platform-dependent: in some platforms that was seen as 35, |
347 | in some as 0, in some as a floating point number (don't ask). This |
348 | was caused by Perl using the operating system libraries in a situation |
349 | where the result of the string to number conversion is undefined: now |
350 | Perl consistently handles such strings as zero in numeric contexts. |
351 | |
352 | =item * |
353 | |
354 | L<dprofpp> -R didn't work. |
355 | |
356 | =item * |
357 | |
358 | PERL5OPT with embedded spaces didn't work. |
359 | |
360 | =item * |
361 | |
362 | L<Sys::Syslog> ignored the C<LOG_AUTH> constant. |
363 | |
364 | =back |
365 | |
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366 | =head2 Platform Specific Changes and Fixes |
367 | |
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368 | =over 4 |
369 | |
370 | =item * |
371 | |
372 | Some versions of glibc have a broken modfl(). This affects builds |
373 | with C<-Duselongdouble>. This version of Perl detects this brokenness |
374 | and has a workaround for it. The glibc release 2.2.2 is known to have |
375 | fixed the modfl() bug. |
376 | |
377 | =back |
378 | |
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379 | =head1 New or Changed Diagnostics |
380 | |
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381 | =over 4 |
382 | |
383 | =item * |
384 | |
385 | In the regular expression diagnostics the C<E<lt>E<lt> HERE> marker |
386 | introduced in 5.7.0 has been changed to be C<E<lt>-- HERE> since too |
387 | many people found the C<E<lt>E<lt>> to be too similar to here-document |
388 | starters. |
389 | |
390 | =item * |
391 | |
392 | If you try to L<perlfunc/pack> a number less than 0 or larger than 255 |
393 | using the C<"C"> format you will get an optional warning. Similarly |
394 | for the C<"c"> format and a number less than -128 or more than 127. |
395 | |
396 | =item * |
397 | |
398 | Certain regex modifiers such as C<(?o)> make sense only if applied to |
399 | the entire regex. You will an optional warning if you try to do otherwise. |
400 | |
401 | =item * |
402 | |
403 | Using arrays or hashes as references (e.g. C<%foo->{bar}> has been |
404 | deprecated for a while. Now you will get an optional warning. |
405 | |
406 | =back |
407 | |
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408 | =head1 Changed Internals |
409 | |
410 | =head2 Regex pre-/post-compilation items matched up |
411 | |
412 | The regex compiler now maintains a structure that identifies nodes in |
413 | the compiled bytecode with the corresponding syntactic features of the |
414 | original regex expression. The information is attached to the new |
415 | C<offsets> member of the C<struct regexp>. See L<perldebguts> for more |
416 | complete information. |
417 | |
418 | =head1 New Tests |
419 | |
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420 | Several new tests have been added, especially for the F<lib> subsection. |
421 | |
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422 | The tests are now reported in a different order than in earlier Perls. |
423 | (This happens because the test scripts from under t/lib have been moved |
424 | to be closer to the library/extension they are testing.) |
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425 | |
43d4bbc8 |
426 | =head1 Known Problems |
427 | |
428 | Note that unlike other sections in this document (which describe |
429 | changes since 5.7.0) this section is cumulative containing known |
430 | problems for all the 5.7 releases. |
431 | |
432 | =head2 AIX vac 5.0.0.0 May Produce Buggy Code For Perl |
433 | |
434 | The AIX C compiler vac version 5.0.0.0 may produce buggy code, |
435 | resulting in few random tests failing, but when the failing tests |
436 | are run by hand, they succeed. We suggest upgrading to at least |
437 | vac version 5.0.1.0, that has been known to compile Perl correctly. |
438 | "lslpp -L|grep vac.C" will tell you the vac version. |
439 | |
440 | =head2 lib/ftmp-security tests warn 'system possibly insecure' |
441 | |
442 | Don't panic. Read INSTALL 'make test' section instead. |
443 | |
444 | =head2 lib/io_multihomed Fails In LP64-Configured HP-UX |
445 | |
446 | The lib/io_multihomed test may hang in HP-UX if Perl has been |
447 | configured to be 64-bit. Because other 64-bit platforms do not hang in |
448 | this test, HP-UX is suspect. All other tests pass in 64-bit HP-UX. The |
449 | test attempts to create and connect to "multihomed" sockets (sockets |
450 | which have multiple IP addresses). |
451 | |
452 | =head2 Test lib/posix Subtest 9 Fails In LP64-Configured HP-UX |
453 | |
454 | If perl is configured with -Duse64bitall, the successful result of the |
455 | subtest 10 of lib/posix may arrive before the successful result of the |
456 | subtest 9, which confuses the test harness so much that it thinks the |
457 | subtest 9 failed. |
458 | |
459 | =head2 lib/b test 19 |
460 | |
461 | The test fails on various platforms (PA64 and IA64 are known), but the |
462 | exact cause is still being investigated. |
463 | |
464 | =head2 Linux With Sfio Fails op/misc Test 48 |
465 | |
466 | No known fix. |
467 | |
468 | =head2 sigaction test 13 in VMS |
469 | |
470 | The test is known to fail; whether it's because of VMS of because |
471 | of faulty test is not known. |
472 | |
473 | =head2 sprintf tests 129 and 130 |
474 | |
475 | The op/sprintf tests 129 and 130 are known to fail on some platforms. |
476 | Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX. |
477 | The failing platforms do not comply with the ANSI C Standard, line |
478 | 19ff on page 134 of ANSI X3.159 1989 to be exact. (They produce |
479 | something else than "1" and "-1" when formatting 0.6 and -0.6 using |
480 | the printf format "%.0f", most often they produce "0" and "-0".) |
481 | |
482 | =head2 Failure of Thread tests |
483 | |
45215428 |
484 | B<Note that support for 5.005-style threading remains experimental.> |
485 | |
486 | The following tests are known to fail due to fundamental problems in |
487 | the 5.005 threading implementation. These are not new failures--Perl |
488 | 5.005_0x has the same bugs, but didn't have these tests. |
489 | |
490 | lib/Memoize/t/correctness.t 23-25 |
491 | lib/Memoize/t/unmemoize.t 2-5 |
492 | t/pragma/autouse.t 4 |
493 | t/lib/thr5005.t 19-20 |
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494 | |
495 | =head2 Localising a Tied Variable Leaks Memory |
496 | |
497 | use Tie::Hash; |
498 | tie my %tie_hash => 'Tie::StdHash'; |
499 | |
500 | ... |
501 | |
502 | local($tie_hash{Foo}) = 1; # leaks |
503 | |
504 | Code like the above is known to leak memory every time the local() |
505 | is executed. |
506 | |
507 | =head2 Self-tying of Arrays and Hashes Is Forbidden |
508 | |
509 | Self-tying of arrays and hashes is broken in rather deep and |
510 | hard-to-fix ways. As a stop-gap measure to avoid people from getting |
511 | frustrated at the mysterious results (core dumps, most often) it is |
512 | for now forbidden (you will get a fatal error even from an attempt). |
513 | |
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514 | =head2 Variable Attributes are not Currently Usable for Tieing |
515 | |
516 | This limitation will hopefully be fixed in future. (Subroutine |
517 | attributes work fine for tieing, see L<Attribute::Handlers>). |
518 | |
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519 | =head2 Building Extensions Can Fail Because Of Largefiles |
520 | |
521 | Some extensions like mod_perl are known to have issues with |
522 | `largefiles', a change brought by Perl 5.6.0 in which file offsets |
523 | default to 64 bits wide, where supported. Modules may fail to compile |
524 | at all or compile and work incorrectly. Currently there is no good |
525 | solution for the problem, but Configure now provides appropriate |
526 | non-largefile ccflags, ldflags, libswanted, and libs in the %Config |
527 | hash (e.g., $Config{ccflags_nolargefiles}) so the extensions that are |
528 | having problems can try configuring themselves without the |
529 | largefileness. This is admittedly not a clean solution, and the |
530 | solution may not even work at all. One potential failure is whether |
531 | one can (or, if one can, whether it's a good idea) link together at |
532 | all binaries with different ideas about file offsets, all this is |
533 | platform-dependent. |
534 | |
535 | =head2 The Compiler Suite Is Still Experimental |
536 | |
537 | The compiler suite is slowly getting better but is nowhere near |
538 | working order yet. |
539 | |
540 | =head1 Reporting Bugs |
541 | |
542 | If you find what you think is a bug, you might check the articles |
543 | recently posted to the comp.lang.perl.misc newsgroup and the perl |
544 | bug database at http://bugs.perl.org. There may also be |
545 | information at http://www.perl.com/perl/, the Perl Home Page. |
546 | |
547 | If you believe you have an unreported bug, please run the B<perlbug> |
548 | program included with your release. Be sure to trim your bug down |
549 | to a tiny but sufficient test case. Your bug report, along with the |
550 | output of C<perl -V>, will be sent off to perlbug@perl.org to be |
551 | analysed by the Perl porting team. |
552 | |
553 | =head1 SEE ALSO |
554 | |
555 | The F<Changes> file for exhaustive details on what changed. |
556 | |
557 | The F<INSTALL> file for how to build Perl. |
558 | |
559 | The F<README> file for general stuff. |
560 | |
561 | The F<Artistic> and F<Copying> files for copyright information. |
562 | |
563 | =head1 HISTORY |
564 | |
565 | Written by Jarkko Hietaniemi <F<jhi@iki.fi>>, with many contributions |
566 | from The Perl Porters and Perl Users submitting feedback and patches. |
567 | |
568 | Send omissions or corrections to <F<perlbug@perl.org>>. |
569 | |
570 | =cut |