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perldelta: bump ExtUtils::ParseXS version
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1=encoding utf8
2
3=head1 NAME
4
5076a392 5perldelta - what is new for perl v5.14.0
c71a852f 6
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7=head1 DESCRIPTION
8
9This document describes differences between the 5.12.0 release and
10the 5.14.0 release.
11
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12If you are upgrading from an earlier release such as 5.10.0, first read
13L<perl5120delta>, which describes differences between 5.10.0 and
145.12.0.
15
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16Some of the bug fixes in this release have been backported to subsequent
17releases of 5.12.x. Those are indicated with the 5.12.x version in
18parentheses.
19
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20=head1 Notice
21
22XXX Any important notices here
23
24=head1 Core Enhancements
25
1f539a1a 26=head2 Unicode
5076a392 27
1f539a1a 28=head3 Unicode Version 6.0 is now supported (mostly)
5076a392 29
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30Perl comes with the Unicode 6.0 data base updated with
31L<Corrigendum #8|http://www.unicode.org/versions/corrigendum8.html>,
32with one exception noted below.
33See L<http://unicode.org/versions/Unicode6.0.0> for details on the new
34release. Perl does not support any Unicode provisional properties,
a3c24add 35including the new ones for this release.
5076a392 36
1f539a1a 37Unicode 6.0 has chosen to use the name C<BELL> for the character at U+1F514,
e1b1739f 38which is a symbol that looks like a bell, and is used in Japanese cell
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39phones. This conflicts with the long-standing Perl usage of having
40C<BELL> mean the ASCII C<BEL> character, U+0007. In Perl 5.14,
41C<\N{BELL}> will continue to mean U+0007, but its use will generate a
42deprecated warning message, unless such warnings are turned off. The
43new name for U+0007 in Perl will be C<ALERT>, which corresponds nicely
44with the existing shorthand sequence for it, C<"\a">. C<\N{BEL}> will
45mean U+0007, with no warning given. The character at U+1F514 will not
46have a name in 5.14, but can be referred to by C<\N{U+1F514}>. The plan
47is that in Perl 5.16, C<\N{BELL}> will refer to U+1F514, and so all code
48that uses C<\N{BELL}> should convert by then to using C<\N{ALERT}>,
49C<\N{BEL}>, or C<"\a"> instead.
5076a392 50
1f539a1a 51=head3 Full functionality for C<use feature 'unicode_strings'>
5076a392 52
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53This release provides full functionality for C<use feature
54'unicode_strings'>. Under its scope, all string operations executed and
55regular expressions compiled (even if executed outside its scope) have
56Unicode semantics. See L<feature>.
5076a392 57
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58This feature avoids most forms of the "Unicode Bug" (See
59L<perlunicode/The "Unicode Bug"> for details.) If there is a
60possibility that your code will process Unicode strings, you are
61B<strongly> encouraged to use this subpragma to avoid nasty surprises.
5076a392 62
1f539a1a 63=head3 C<\N{I<name>}> and C<charnames> enhancements
5076a392 64
1f539a1a 65=over
5076a392 66
1f539a1a 67=item *
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68
69C<\N{}> and C<charnames::vianame> now know about the abbreviated
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70character names listed by Unicode, such as NBSP, SHY, LRO, ZWJ, etc., all
71the customary abbreviations for the C0 and C1 control characters (such as
72ACK, BEL, CAN, etc.), and a few new variants of some C1 full names that
73are in common usage.
5076a392 74
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75=item *
76
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77Unicode has a number of named character sequences, in which particular sequences
78of code points are given names. C<\N{...}> now recognizes these.
79
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80=item *
81
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82C<\N{}>, C<charnames::vianame>, C<charnames::viacode> now know about every
83character in Unicode. Previously, they didn't know about the Hangul syllables
84nor a number of CJK (Chinese/Japanese/Korean) characters.
85
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86=item *
87
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88In the past, it was ineffective to override one of Perl's abbreviations
89with your own custom alias. Now it works.
90
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91=item *
92
e1b1739f 93You can also create a custom alias of the ordinal of a
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94character, known by C<\N{...}>, C<charnames::vianame()>, and
95C<charnames::viacode()>. Previously, an alias had to be to an official
96Unicode character name. This made it impossible to create an alias for
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97a code point that had no name, such as those reserved for private
98use.
5076a392 99
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100=item *
101
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102A new function, C<charnames::string_vianame()>, has been added.
103This function is a run-time version of C<\N{...}>, returning the string
104of characters whose Unicode name is its parameter. It can handle
105Unicode named character sequences, whereas the pre-existing
106C<charnames::vianame()> cannot, as the latter returns a single code
107point.
108
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109=back
110
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111See L<charnames> for details on all these changes.
112
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113=head3 New warnings categories for problematic (non-)Unicode code points.
114
115Three new warnings subcategories of "utf8" have been added. These
116allow you to turn off some "utf8" warnings, while allowing
117others warnings to remain on. The three categories are:
118C<surrogate> when UTF-16 surrogates are encountered;
119C<nonchar> when Unicode non-character code points are encountered;
120and C<non_unicode> when code points that are above the legal Unicode
121maximum of 0x10FFFF are encountered.
122
1f539a1a 123=head3 Any unsigned value can be encoded as a character
5076a392 124
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125With this release, Perl is adopting a model that any unsigned value can
126be treated as a code point and encoded internally (as utf8) without
54c7bb16 127warnings - not just the code points that are legal in Unicode.
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128However, unless utf8 or the corresponding sub-category (see previous
129item) warnings have been
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130explicitly lexically turned off, outputting or performing a
131Unicode-defined operation (such as upper-casing) on such a code point
132will generate a warning. Attempting to input these using strict rules
133(such as with the C<:encoding('UTF-8')> layer) will continue to fail.
134Prior to this release the handling was very inconsistent, and incorrect
135in places. Also, the Unicode non-characters, some of which previously were
136erroneously considered illegal in places by Perl, contrary to the Unicode
137standard, are now always legal internally. But inputting or outputting
138them will work the same as for the non-legal Unicode code points, as the
139Unicode standard says they are illegal for "open interchange".
5076a392 140
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141=head3 Unicode database files not installed
142
143The Unicode database files are no longer installed with Perl. This
144doesn't affect any functionality in Perl and saves significant disk
145space. If you previously were explicitly opening and reading those
146files, you can download them from
147L<http://www.unicode.org/Public/zipped/6.0.0/>.
148
1f539a1a 149=head2 Regular Expressions
5076a392 150
1f539a1a 151=head3 C<(?^...)> construct to signify default modifiers
5076a392 152
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153An ASCII caret (also called a "circumflex accent") C<"^">
154immediately following a C<"(?"> in a regular expression
155now means that the subexpression does not inherit the
156surrounding modifiers such as C</i>, but reverts to the
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157Perl defaults. Any modifiers following the caret override the defaults.
158
159The stringification of regular expressions now uses this
160notation. E.g., before, C<qr/hlagh/i> would be stringified as
161C<(?i-xsm:hlagh)>, but now it's stringified as C<(?^i:hlagh)>.
162
163The main purpose of this is to allow tests that rely on the
e1b1739f 164stringification not to have to change when new modifiers are added.
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165See L<perlre/Extended Patterns>.
166
1f539a1a 167=head3 C</d>, C</l>, C</u>, C</a>, and C</aa> modifiers
5076a392 168
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169Four new regular expression modifiers have been added. These are mutually
170exclusive; one only can be turned on at a time.
5076a392 171
959ad7d5 172The C</l> modifier says to compile the regular expression as if it were
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173in the scope of C<use locale>, even if it is not.
174
959ad7d5 175The C</u> modifier says to compile the regular expression as if it were
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176in the scope of a C<use feature "unicode_strings"> pragma.
177
e1b1739f 178The C</d> (default) modifier is used to override any C<use locale> and
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179C<use feature "unicode_strings"> pragmas that are in effect at the time
180of compiling the regular expression.
181
959ad7d5 182The C</a> regular expression modifier restricts C<\s>, C<\d> and C<\w> and
7baaf023 183the Posix (C<[[:posix:]]>) character classes to the ASCII range. Their
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184complements and C<\b> and C<\B> are correspondingly
185affected. Otherwise, C</a> behaves like the C</u> modifier, in that
e1b1739f 186case-insensitive matching uses Unicode semantics.
5076a392 187
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188The C</aa> modifier is like C</a>, except that, in case-insensitive matching, no ASCII character will match a
189non-ASCII character. For example,
5076a392 190
959ad7d5 191 'k' =~ /\N{KELVIN SIGN}/ai
5076a392 192
959ad7d5 193will match; it won't under C</aa>.
5076a392 194
959ad7d5 195See L<perlre/Modifiers> for more detail.
5076a392 196
1f539a1a 197=head3 Non-destructive substitution
5076a392 198
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199The substitution (C<s///>) and transliteration
200(C<y///>) operators now support an C</r> option that
201copies the input variable, carries out the substitution on
202the copy and returns the result. The original remains unmodified.
5076a392 203
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204 my $old = 'cat';
205 my $new = $old =~ s/cat/dog/r;
206 # $old is 'cat' and $new is 'dog'
5076a392 207
1f539a1a 208This is particularly useful with C<map>. See L<perlop> for more examples.
5076a392 209
1f539a1a 210=head3 Reentrant regular expression engine
5076a392 211
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212It is now safe to use regular expressions within C<(?{...})> and
213C<(??{...})> code blocks inside regular expressions.
5076a392 214
1f539a1a 215These block are still experimental, however, and still have problems with
e1b1739f 216lexical (C<my>) variables and abnormal exiting.
5076a392 217
1f539a1a 218=head3 C<use re '/flags';>
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219
220The C<re> pragma now has the ability to turn on regular expression flags
221till the end of the lexical scope:
222
223 use re '/x';
224 "foo" =~ / (.+) /; # /x implied
225
226See L<re/"'/flags' mode"> for details.
227
1f539a1a 228=head3 \o{...} for octals
5076a392 229
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230There is a new octal escape sequence, C<"\o">, in double-quote-like
231contexts. This construct allows large octal ordinals beyond the
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232current max of 0777 to be represented. It also allows you to specify a
233character in octal which can safely be concatenated with other regex
234snippets and which won't be confused with being a backreference to
235a regex capture group. See L<perlre/Capture groups>.
236
237=head3 Add C<\p{Titlecase}> as a synonym for C<\p{Title}>
238
239This synonym is added for symmetry with the Unicode property names
240C<\p{Uppercase}> and C<\p{Lowercase}>.
5076a392 241
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242=head3 Regular expression debugging output improvement
243
244Regular expression debugging output (turned on by C<use re 'debug';>) now
245uses hexadecimal when escaping non-ASCII characters, instead of octal.
246
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247=head3 Return value of C<delete $+{...}>
248
249Custom regular expression engines can now determine the return value of
250C<delete> on an entry of C<%+> or C<%->.
251
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252=head2 Syntactical Enhancements
253
254=head3 Array and hash container functions accept references
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255
256All built-in functions that operate directly on array or hash
257containers now also accept hard references to arrays or hashes:
258
259 |----------------------------+---------------------------|
260 | Traditional syntax | Terse syntax |
261 |----------------------------+---------------------------|
262 | push @$arrayref, @stuff | push $arrayref, @stuff |
263 | unshift @$arrayref, @stuff | unshift $arrayref, @stuff |
264 | pop @$arrayref | pop $arrayref |
265 | shift @$arrayref | shift $arrayref |
266 | splice @$arrayref, 0, 2 | splice $arrayref, 0, 2 |
267 | keys %$hashref | keys $hashref |
268 | keys @$arrayref | keys $arrayref |
269 | values %$hashref | values $hashref |
270 | values @$arrayref | values $arrayref |
271 | ($k,$v) = each %$hashref | ($k,$v) = each $hashref |
272 | ($k,$v) = each @$arrayref | ($k,$v) = each $arrayref |
273 |----------------------------+---------------------------|
274
275This allows these built-in functions to act on long dereferencing chains
276or on the return value of subroutines without needing to wrap them in
277C<@{}> or C<%{}>:
278
279 push @{$obj->tags}, $new_tag; # old way
280 push $obj->tags, $new_tag; # new way
281
282 for ( keys %{$hoh->{genres}{artists}} ) {...} # old way
283 for ( keys $hoh->{genres}{artists} ) {...} # new way
284
285For C<push>, C<unshift> and C<splice>, the reference will auto-vivify
286if it is not defined, just as if it were wrapped with C<@{}>.
287
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288For C<keys>, C<values>, C<each>, when overloaded dereferencing is
289present, the overloaded dereference is used instead of dereferencing the
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290underlying reftype. Warnings are issued about assumptions made in
291ambiguous cases.
5076a392 292
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293=head3 Single term prototype
294
295The C<+> prototype is a special alternative to C<$> that will act like
296C<\[@%]> when given a literal array or hash variable, but will otherwise
e1b1739f 297force scalar context on the argument. See L<perlsub/Prototypes>.
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298
299=head3 C<package> block syntax
300
301A package declaration can now contain a code block, in which case the
302declaration is in scope only inside that block. So C<package Foo { ... }>
303is precisely equivalent to C<{ package Foo; ... }>. It also works with
304a version number in the declaration, as in C<package Foo 1.2 { ... }>.
e1b1739f 305See L<perlfunc>.
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306
307=head3 Statement labels can appear in more places
308
309Statement labels can now occur before any type of statement or declaration,
310such as C<package>.
311
312=head3 Stacked labels
313
314Multiple statement labels can now appear before a single statement.
315
316=head3 Uppercase X/B allowed in hexadecimal/binary literals
317
318Literals may now use either upper case C<0X...> or C<0B...> prefixes,
319in addition to the already supported C<0x...> and C<0b...>
e1b1739f 320syntax [perl #76296].
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321
322C, Ruby, Python and PHP already supported this syntax, and it makes
323Perl more internally consistent. A round-trip with C<eval sprintf
e1b1739f 324"%#X", 0x10> now returns C<16>, the way C<eval sprintf "%#x", 0x10> does.
1f539a1a 325
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326=head3 Overridable tie functions
327
328C<tie>, C<tied> and C<untie> can now be overridden [perl #75902].
329
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330=head2 Exception Handling
331
332Several changes have been made to the way C<die>, C<warn>, and C<$@>
333behave, in order to make them more reliable and consistent.
334
335When an exception is thrown inside an C<eval>, the exception is no
336longer at risk of being clobbered by code running during unwinding
337(e.g., destructors). Previously, the exception was written into C<$@>
338early in the throwing process, and would be overwritten if C<eval> was
339used internally in the destructor for an object that had to be freed
340while exiting from the outer C<eval>. Now the exception is written
341into C<$@> last thing before exiting the outer C<eval>, so the code
342running immediately thereafter can rely on the value in C<$@> correctly
343corresponding to that C<eval>. (C<$@> is still also set before exiting the
344C<eval>, for the sake of destructors that rely on this.)
345
346Likewise, a C<local $@> inside an C<eval> will no longer clobber any
347exception thrown in its scope. Previously, the restoration of C<$@> upon
348unwinding would overwrite any exception being thrown. Now the exception
349gets to the C<eval> anyway. So C<local $@> is safe before a C<die>.
350
351Exceptions thrown from object destructors no longer modify the C<$@>
352of the surrounding context. (If the surrounding context was exception
353unwinding, this used to be another way to clobber the exception being
354thrown.) Previously such an exception was
355sometimes emitted as a warning, and then either was
356string-appended to the surrounding C<$@> or completely replaced the
357surrounding C<$@>, depending on whether that exception and the surrounding
358C<$@> were strings or objects. Now, an exception in this situation is
359always emitted as a warning, leaving the surrounding C<$@> untouched.
360In addition to object destructors, this also affects any function call
361performed by XS code using the C<G_KEEPERR> flag.
362
363Warnings for C<warn> can now be objects, in the same way as exceptions
364for C<die>. If an object-based warning gets the default handling,
365of writing to standard error, it is stringified as
366before, with the file and line number appended. But
367a C<$SIG{__WARN__}> handler will now receive an
368object-based warning as an object, where previously it was passed the
369result of stringifying the object.
370
371=head2 Other Enhancements
372
373=head3 Assignment to C<$0> sets the legacy process name with C<prctl()> on Linux
374
375On Linux the legacy process name will be set with L<prctl(2)>, in
376addition to altering the POSIX name via C<argv[0]> as perl has done
377since version 4.000. Now system utilities that read the legacy process
378name such as ps, top and killall will recognize the name you set when
379assigning to C<$0>. The string you supply will be cut off at 16 bytes,
380this is a limitation imposed by Linux.
381
382=head3 C<srand()> now returns the seed
383
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384This allows programs that need to have repeatable results not to have to come
385up with their own seed-generating mechanism. Instead, they can use C<srand()>
386and stash the return value for future use. Typical is a test program which
1f539a1a 387has too many combinations to test comprehensively in the time available to it
e1b1739f 388each run. It can test a random subset each time and, should there be a failure,
1f539a1a 389log the seed used for that run so that it can later be used to reproduce the
e1b1739f 390same results.
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391
392=head3 printf-like functions understand post-1980 size modifiers
393
394Perl's printf and sprintf operators, and Perl's internal printf replacement
395function, now understand the C90 size modifiers "hh" (C<char>), "z"
396(C<size_t>), and "t" (C<ptrdiff_t>). Also, when compiled with a C99
397compiler, Perl now understands the size modifier "j" (C<intmax_t>).
398
399So, for example, on any modern machine, C<sprintf('%hhd', 257)> returns '1'.
400
401=head3 New global variable C<${^GLOBAL_PHASE}>
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402
403A new global variable, C<${^GLOBAL_PHASE}>, has been added to allow
404introspection of the current phase of the perl interpreter. It's explained in
405detail in L<perlvar/"${^GLOBAL_PHASE}"> and
406L<perlmod/"BEGIN, UNITCHECK, CHECK, INIT and END">.
407
1f539a1a 408=head3 C<-d:-foo> calls C<Devel::foo::unimport>
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409
410The syntax C<-dI<B<:>foo>> was extended in 5.6.1 to make C<-dI<:fooB<=bar>>>
411equivalent to C<-MDevel::foo=bar>, which expands
412internally to C<use Devel::foo 'bar';>.
413F<perl> now allows prefixing the module name with C<->, with the same
414semantics as C<-M>, I<i.e.>
415
416=over 4
417
418=item C<-d:-foo>
419
420Equivalent to C<-M-Devel::foo>, expands to
421C<no Devel::foo;>, calls C<< Devel::foo->unimport() >>
422if the method exists.
423
424=item C<-d:-foo=bar>
425
426Equivalent to C<-M-Devel::foo=bar>, expands to C<no Devel::foo 'bar';>,
427calls C<< Devel::foo->unimport('bar') >> if the method exists.
428
429=back
430
e1b1739f 431This is particularly useful for suppressing the default actions of a
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432C<Devel::*> module's C<import> method whilst still loading it for debugging.
433
1f539a1a 434=head3 Filehandle method calls load L<IO::File> on demand
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435
436When a method call on a filehandle would die because the method cannot
437be resolved, and L<IO::File> has not been loaded, Perl now loads L<IO::File>
438via C<require> and attempts method resolution again:
439
440 open my $fh, ">", $file;
441 $fh->binmode(":raw"); # loads IO::File and succeeds
442
443This also works for globs like STDOUT, STDERR and STDIN:
444
445 STDOUT->autoflush(1);
446
447Because this on-demand load only happens if method resolution fails, the
448legacy approach of manually loading an L<IO::File> parent class for partial
449method support still works as expected:
450
451 use IO::Handle;
452 open my $fh, ">", $file;
453 $fh->autoflush(1); # IO::File not loaded
454
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455=head3 IPv6 support
456
457The C<Socket> module provides new affordances for IPv6,
458including implementations of the C<Socket::getaddrinfo()> and
459C<Socket::getnameinfo()> functions, along with related constants, and a
460handful of new functions. See L<Socket>.
461
1f539a1a 462=head3 DTrace probes now include package name
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463
464The DTrace probes now include an additional argument (C<arg3>) which contains
465the package the subroutine being entered or left was compiled in.
466
467For example using the following DTrace script:
468
469 perl$target:::sub-entry
470 {
471 printf("%s::%s\n", copyinstr(arg0), copyinstr(arg3));
472 }
473
474and then running:
475
476 perl -e'sub test { }; test'
477
478DTrace will print:
479
480 main::test
481
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482=head2 New C APIs
483
1e463951 484See L</Internal Changes>.
9378886b 485
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486=head1 Security
487
948b8455 488=head2 User-defined regular expression properties
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489
490In L<perlunicode/"User-Defined Character Properties">, it says you can
491create custom properties by defining subroutines whose names begin with
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492"In" or "Is". However, Perl did not actually enforce that naming
493restriction, so \p{foo::bar} could call foo::bar() if it existed. Now this
494convention has been enforced.
5076a392 495
948b8455 496Also, Perl no longer allows a tainted regular expression to invoke a
8c6a0c82 497user-defined property. It simply dies instead [perl #82616].
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498
499=head1 Incompatible Changes
500
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501Perl 5.14.0 is not binary-compatible with any previous stable release.
502
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503In addition to the sections that follow, see L</C API Changes>.
504
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505=head2 Regular Expressions and String Escapes
506
54c7bb16 507=head3 \400-\777
5076a392 508
54c7bb16 509Use of C<\400>-C<\777> in regexes in certain circumstances has given
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510different, anomalous behavior than their use in all other
511double-quote-like contexts. Since 5.10.1, a deprecated warning message
512has been raised when this happens. Now, all double-quote-like contexts
513have the same behavior, namely to be equivalent to C<\x{100}> -
514C<\x{1FF}>, with no deprecation warning. Use of these values in the
515command line option C<"-0"> retains the current meaning to slurp input
516files whole; previously, this was documented only for C<"-0777">. It is
517recommended, however, because of various ambiguities, to use the new
518C<\o{...}> construct to represent characters in octal.
5076a392 519
61752d82 520=head3 Most C<\p{}> properties are now immune to case-insensitive matching
5076a392 521
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522For most Unicode properties, it doesn't make sense to have them match
523differently under C</i> case-insensitive matching than not. And doing
524so leads to unexpected results and potential security holes. For
525example
5076a392 526
61752d82 527 m/\p{ASCII_Hex_Digit}+/i
5076a392 528
61752d82 529could previously match non-ASCII characters because of the Unicode
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530matching rules (although there were a number of bugs with this). Now
531matching under C</i> gives the same results as non-C</i> matching except
532for those few properties where people have come to expect differences,
533namely the ones where casing is an integral part of their meaning, such
534as C<m/\p{Uppercase}/i> and C<m/\p{Lowercase}/i>, both of which match
535the exact same code points, namely those matched by C<m/\p{Cased}/i>.
536Details are in L<perlrecharclass/Unicode Properties>.
5076a392 537
61752d82 538User-defined property handlers that need to match differently under
4cf6a51f 539C</i> must change to read the new boolean parameter passed to them which is
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540non-zero if case-insensitive matching is in effect or 0 otherwise. See
541L<perluniprops/User-Defined Character Properties>.
5076a392 542
61752d82 543=head3 \p{} implies Unicode semantics
5076a392 544
61752d82
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545Now, a Unicode property match specified in the pattern will indicate
546that the pattern is meant for matching according to Unicode rules, the way
bc15a0a0 547C<\N{}> does.
5076a392 548
61752d82 549=head3 Regular expressions retain their localeness when interpolated
5076a392 550
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551Regular expressions compiled under C<"use locale"> now retain this when
552interpolated into a new regular expression compiled outside a
553C<"use locale">, and vice-versa.
5076a392 554
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555Previously, a regular expression interpolated into another one inherited
556the localeness of the surrounding one, losing whatever state it
557originally had. This is considered a bug fix, but may trip up code that
558has come to rely on the incorrect behavior.
5076a392 559
61752d82 560=head3 Stringification of regexes has changed
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561
562Default regular expression modifiers are now notated by using
563C<(?^...)>. Code relying on the old stringification will fail. The
564purpose of this is so that when new modifiers are added, such code will
565not have to change (after this one time), as the stringification will
566automatically incorporate the new modifiers.
567
568Code that needs to work properly with both old- and new-style regexes
f318e2e6 569can avoid the whole issue by using (for Perls since 5.9.5; see L<re>):
5076a392
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570
571 use re qw(regexp_pattern);
572 my ($pat, $mods) = regexp_pattern($re_ref);
573
5076a392
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574If the actual stringification is important, or older Perls need to be
575supported, you can use something like the following:
576
577 # Accept both old and new-style stringification
578 my $modifiers = (qr/foobar/ =~ /\Q(?^/) ? '^' : '-xism';
579
580And then use C<$modifiers> instead of C<-xism>.
581
61752d82 582=head3 Run-time code blocks in regular expressions inherit pragmata
5076a392 583
61752d82
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584Code blocks in regular expressions (C<(?{...})> and C<(??{...})>) used not
585to inherit any pragmata (strict, warnings, etc.) if the regular expression
586was compiled at run time as happens in cases like these two:
5076a392 587
61752d82
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588 use re 'eval';
589 $foo =~ $bar; # when $bar contains (?{...})
590 $foo =~ /$bar(?{ $finished = 1 })/;
591
592This was a bug, which has now been fixed. But it has the potential to break
593any code that was relying on it.
5076a392 594
61752d82 595=head2 Stashes and Package Variables
5076a392 596
61752d82 597=head3 Localised tied hashes and arrays are no longed tied
5076a392 598
61752d82 599In the following:
5076a392 600
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601 tie @a, ...;
602 {
603 local @a;
604 # here, @a is a now a new, untied array
605 }
606 # here, @a refers again to the old, tied array
5076a392 607
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608The new local array used to be made tied too, which was fairly pointless,
609and has now been fixed. This fix could however potentially cause a change
610in behaviour of some code.
5076a392 611
61752d82 612=head3 Stashes are now always defined
5076a392 613
61752d82
FC
614C<defined %Foo::> now always returns true, even when no symbols have yet been
615defined in that package.
5076a392 616
61752d82
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617This is a side effect of removing a special case kludge in the tokeniser,
618added for 5.10.0, to hide side effects of changes to the internal storage of
619hashes that drastically reduce their memory usage overhead.
620
621Calling defined on a stash has been deprecated since 5.6.0, warned on
622lexicals since 5.6.0, and warned for stashes (and other package
623variables) since 5.12.0. C<defined %hash> has always exposed an
624implementation detail - emptying a hash by deleting all entries from it does
625not make C<defined %hash> false, hence C<defined %hash> is not valid code to
626determine whether an arbitrary hash is empty. Instead, use the behaviour
627that an empty C<%hash> always returns false in a scalar context.
628
629=head3 Dereferencing typeglobs
5076a392
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630
631If you assign a typeglob to a scalar variable:
632
633 $glob = *foo;
634
635the glob that is copied to C<$glob> is marked with a special flag
636indicating that the glob is just a copy. This allows subsequent assignments
637to C<$glob> to overwrite the glob. The original glob, however, is
638immutable.
639
640Many Perl operators did not distinguish between these two types of globs.
641This would result in strange behaviour in edge cases: C<untie $scalar>
642would do nothing if the last thing assigned to the scalar was a glob
643(because it treated it as C<untie *$scalar>, which unties a handle).
f318e2e6 644Assignment to a glob slot (e.g., C<*$glob = \@some_array>) would simply
5076a392
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645assign C<\@some_array> to C<$glob>.
646
647To fix this, the C<*{}> operator (including the C<*foo> and C<*$foo> forms)
648has been modified to make a new immutable glob if its operand is a glob
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FC
649copy. This allows operators that make a distinction between globs and
650scalars to be modified to treat only immutable globs as globs. (C<tie>,
651C<tied> and C<untie> have been left as they are for compatibility's sake,
61752d82 652but will warn. See L</Deprecations>.)
5076a392
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653
654This causes an incompatible change in code that assigns a glob to the
655return value of C<*{}> when that operator was passed a glob copy. Take the
656following code, for instance:
657
658 $glob = *foo;
659 *$glob = *bar;
660
661The C<*$glob> on the second line returns a new immutable glob. That new
662glob is made an alias to C<*bar>. Then it is discarded. So the second
663assignment has no effect.
664
5076a392
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665See L<http://rt.perl.org/rt3/Public/Bug/Display.html?id=77810> for even
666more detail.
667
61752d82 668=head3 Clearing stashes
5076a392
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669
670Stash list assignment C<%foo:: = ()> used to make the stash anonymous
671temporarily while it was being emptied. Consequently, any of its
672subroutines referenced elsewhere would become anonymous (showing up as
673"(unknown)" in C<caller>). Now they retain their package names, such that
674C<caller> will return the original sub name if there is still a reference
675to its typeglob, or "foo::__ANON__" otherwise [perl #79208].
676
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677=head3 Magic variables outside the main package
678
679In previous versions of Perl, magic variables like C<$!>, C<%SIG>, etc. would
680'leak' into other packages. So C<%foo::SIG> could be used to access signals,
681C<${"foo::!"}> (with strict mode off) to access C's C<errno>, etc.
682
683This was a bug, or an 'unintentional' feature, which caused various ill effects,
684such as signal handlers being wiped when modules were loaded, etc.
685
686This has been fixed (or the feature has been removed, depending on how you see
687it).
688
689=head2 Changes to Syntax or to Perl Operators
690
691=head3 C<given> return values
692
693C<given> blocks now return the last evaluated
694expression, or an empty list if the block was exited by C<break>. Thus you
695can now write:
696
697 my $type = do {
698 given ($num) {
699 break when undef;
700 'integer' when /^[+-]?[0-9]+$/;
701 'float' when /^[+-]?[0-9]+(?:\.[0-9]+)?$/;
702 'unknown';
703 }
704 };
705
706See L<perlsyn/Return value> for details.
707
708=head3 Change in the parsing of certain prototypes
709
710Functions declared with the following prototypes now behave correctly as unary
711functions:
712
713 *
714 \$ \% \@ \* \&
715 \[...]
716 ;$ ;*
717 ;\$ ;\% etc.
718 ;\[...]
719
720Due to this bug fix [perl #75904], functions
721using the C<(*)>, C<(;$)> and C<(;*)> prototypes
722are parsed with higher precedence than before. So in the following example:
723
724 sub foo($);
725 foo $a < $b;
726
727the second line is now parsed correctly as C<< foo($a) < $b >>, rather than
728C<< foo($a < $b) >>. This happens when one of these operators is used in
729an unparenthesised argument:
730
731 < > <= >= lt gt le ge
732 == != <=> eq ne cmp ~~
733 &
734 | ^
735 &&
736 || //
737 .. ...
738 ?:
739 = += -= *= etc.
740
741=head3 Smart-matching against array slices
742
743Previously, the following code resulted in a successful match:
744
745 my @a = qw(a y0 z);
746 my @b = qw(a x0 z);
747 @a[0 .. $#b] ~~ @b;
748
749This odd behaviour has now been fixed [perl #77468].
750
751=head3 Negation treats strings differently from before
752
753The unary negation operator C<-> now treats strings that look like numbers
754as numbers [perl #57706].
755
756=head3 Negative zero
757
758Negative zero (-0.0), when converted to a string, now becomes "0" on all
759platforms. It used to become "-0" on some, but "0" on others.
760
761If you still need to determine whether a zero is negative, use
762C<sprintf("%g", $zero) =~ /^-/> or the L<Data::Float> module on CPAN.
763
764=head3 C<:=> is now a syntax error
5076a392
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765
766Previously C<my $pi := 4;> was exactly equivalent to C<my $pi : = 4;>,
767with the C<:> being treated as the start of an attribute list, ending before
768the C<=>. The use of C<:=> to mean C<: => was deprecated in 5.12.0, and is now
769a syntax error. This will allow the future use of C<:=> as a new token.
770
771We find no Perl 5 code on CPAN using this construction, outside the core's
772tests for it, so we believe that this change will have very little impact on
773real-world codebases.
774
775If it is absolutely necessary to have empty attribute lists (for example,
776because of a code generator) then avoid the error by adding a space before
777the C<=>.
778
61752d82 779=head2 Threads and Processes
5076a392 780
61752d82 781=head3 Directory handles not copied to threads
5076a392 782
61752d82
FC
783On systems other than Windows that do not have
784a C<fchdir> function, newly-created threads no
785longer inherit directory handles from their parent threads. Such programs
786would usually have crashed anyway [perl #75154].
5076a392 787
61752d82 788=head3 C<close> on shared pipes
5076a392 789
61752d82
FC
790The C<close> function no longer waits for the child process to exit if the
791underlying file descriptor is still in use by another thread, to avoid
792deadlocks. It returns true in such cases.
5076a392 793
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794=head3 fork() emulation will not wait for signalled children
795
796On Windows parent processes would not terminate until all forked
797childred had terminated first. However, C<kill('KILL', ...)> is
798inherently unstable on pseudo-processes, and C<kill('TERM', ...)>
799might not get delivered if the child if blocked in a system call.
800
801To avoid the deadlock and still provide a safe mechanism to terminate
802the hosting process, Perl will now no longer wait for children that
803have been sent a SIGTERM signal. It is up to the parent process to
804waitpid() for these children if child clean-up processing must be
805allowed to finish. However, it is also the responsibility of the
806parent then to avoid the deadlock by making sure the child process
807can't be blocked on I/O either.
808
809See L<perlfork> for more information about the fork() emulation on
810Windows.
811
61752d82 812=head2 Configuration
5076a392 813
61752d82 814=head3 Naming fixes in Policy_sh.SH may invalidate Policy.sh
5076a392 815
61752d82
FC
816Several long-standing typos and naming confusions in Policy_sh.SH have
817been fixed, standardizing on the variable names used in config.sh.
5076a392 818
61752d82
FC
819This will change the behavior of Policy.sh if you happen to have been
820accidentally relying on the Policy.sh incorrect behavior.
f318e2e6 821
5a1f7719
FC
822=head3 Perl source code is read in text mode on Windows
823
824Perl scripts used to be read in binary mode on Windows for the benefit
825of the ByteLoader module (which is no longer part of core Perl). This
826had the side effect of breaking various operations on the DATA filehandle,
827including seek()/tell(), and even simply reading from DATA after file handles
828have been flushed by a call to system(), backticks, fork() etc.
829
830The default build options for Windows have been changed to read Perl source
831code on Windows in text mode now. Hopefully ByteLoader will be updated on
832CPAN to automatically handle this situation [perl #28106].
833
5076a392
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834=head1 Deprecations
835
1e463951
FC
836See also L</Deprecated C APIs>.
837
5076a392
FC
838=head2 Omitting a space between a regular expression and subsequent word
839
18139a1b
FC
840Omitting a space between a regular expression operator or
841its modifiers and the following word is deprecated. For
842example, C<< m/foo/sand $bar >> will still be parsed
843as C<< m/foo/s and $bar >> but will issue a warning.
5076a392 844
e683df94
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845=head2 C<\cI<X>>
846
847The backslash-c construct was designed as a way of specifying
848non-printable characters, but there were no restrictions (on ASCII
849platforms) on what the character following the C<c> could be. Now,
850a deprecation warning is raised if that character isn't an ASCII character.
851Also, a deprecation warning is raised for C<"\c{"> (which is the same
852as simply saying C<";">).
853
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KW
854=head2 C<"\b{"> and C<"\B{">
855
856In regular expressions, a literal C<"{"> immediately following a C<"\b">
857(not in a bracketed character class) or a C<"\B{"> is now deprecated
858to allow for its future use by Perl itself.
859
5076a392
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860=head2 Deprecation warning added for deprecated-in-core .pl libs
861
862This is a mandatory warning, not obeying -X or lexical warning bits.
863The warning is modelled on that supplied by deprecate.pm for
864deprecated-in-core .pm libraries. It points to the specific CPAN
823d0e46
FC
865distribution that contains the .pl libraries. The CPAN version, of
866course, does not generate the warning.
5076a392
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867
868=head2 List assignment to C<$[>
869
823d0e46
FC
870Assignment to C<$[> was deprecated and started to give warnings in
871Perl version 5.12.0. This version of perl also starts to emit a warning when
872assigning to C<$[> in list context. This fixes an oversight in 5.12.0.
5076a392
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873
874=head2 Use of qw(...) as parentheses
875
876Historically the parser fooled itself into thinking that C<qw(...)> literals
877were always enclosed in parentheses, and as a result you could sometimes omit
878parentheses around them:
879
880 for $x qw(a b c) { ... }
881
882The parser no longer lies to itself in this way. Wrap the list literal in
823d0e46 883parentheses, like this:
5076a392
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884
885 for $x (qw(a b c)) { ... }
886
887=head2 C<\N{BELL}> is deprecated
888
889This is because Unicode is using that name for a different character.
890See L</Unicode Version 6.0 is now supported (mostly)> for more
891explanation.
892
893=head2 C<?PATTERN?> is deprecated
894
895C<?PATTERN?> (without the initial m) has been deprecated and now produces
896a warning. This is to allow future use of C<?> in new operators.
897The match-once functionality is still available in the form of C<m?PATTERN?>.
898
5076a392
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899=head2 Tie functions on scalars holding typeglobs
900
901Calling a tie function (C<tie>, C<tied>, C<untie>) with a scalar argument
902acts on a file handle if the scalar happens to hold a typeglob.
903
904This is a long-standing bug that will be removed in Perl 5.16, as
905there is currently no way to tie the scalar itself when it holds
906a typeglob, and no way to untie a scalar that has had a typeglob
907assigned to it.
908
823d0e46 909Now there is a deprecation warning whenever a tie
5076a392
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910function is used on a handle without an explicit C<*>.
911
18139a1b 912=head2 User-defined case-mapping
5076a392 913
18139a1b
FC
914This feature is being deprecated due to its many issues, as documented in
915L<perlunicode/User-Defined Case Mappings (for serious hackers only)>.
e48f36f0
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916It is planned to remove this feature in Perl 5.16. Instead use the CPAN module
917L<Unicode::Casing>, which provides improved functionality.
823d0e46 918
18139a1b 919=head2 Deprecated modules
5076a392
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920
921The following modules will be removed from the core distribution in a
922future release, and should be installed from CPAN instead. Distributions
923on CPAN which require these should add them to their prerequisites. The
823d0e46 924core versions of these modules will issue a deprecation warning.
5076a392
FC
925
926If you ship a packaged version of Perl, either alone or as part of a
927larger system, then you should carefully consider the repercussions of
823d0e46 928core module deprecations. You may want to consider shipping your default
5076a392 929build of Perl with packages for some or all deprecated modules which
823d0e46 930install into C<vendor> or C<site> perl library directories. This will
5076a392
FC
931inhibit the deprecation warnings.
932
933Alternatively, you may want to consider patching F<lib/deprecate.pm>
934to provide deprecation warnings specific to your packaging system
935or distribution of Perl, consistent with how your packaging system
936or distribution manages a staged transition from a release where the
937installation of a single package provides the given functionality, to
938a later release where the system administrator needs to know to install
939multiple packages to get that same functionality.
940
941You can silence these deprecation warnings by installing the modules
942in question from CPAN. To install the latest version of all of them,
943just install C<Task::Deprecations::5_14>.
944
945=over
946
947=item L<Devel::DProf>
948
949We strongly recommend that you install and used L<Devel::NYTProf> in
950preference, as it offers significantly improved profiling and reporting.
951
952=back
953
5076a392
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954=head1 Performance Enhancements
955
54c7bb16 956=head2 "Safe signals" optimisation
df91d470
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957
958Signal dispatch has been moved from the runloop into control ops. This
959should give a few percent speed increase, and eliminates almost all of
960the speed penalty caused by the introduction of "safe signals" in
9615.8.0. Signals should still be dispatched within the same statement as
962they were previously - if this is not the case, or it is possible to
963create uninterruptible loops, this is a bug, and reports are encouraged
964of how to recreate such issues.
965
54c7bb16 966=head2 Optimisation of shift; and pop; calls without arguments
df91d470 967
111b6aa7
FC
968Two fewer OPs are used for shift and pop calls with no argument (with
969implicit C<@_>). This change makes C<shift;> 5% faster than C<shift @_;>
970on non-threaded perls and 25% faster on threaded.
df91d470 971
fa232254 972=head2 Optimisation of regexp engine string comparison work
df91d470 973
fa232254
FC
974The foldEQ_utf8 API function for case-insensitive comparison of strings (which
975is used heavily by the regexp engine) was substantially refactored and
976optimised - and its documentation much improved as a free bonus gift.
df91d470 977
fa232254 978=head2 Regular expression compilation speed-up
df91d470 979
fa232254
FC
980Compiling regular expressions has been made faster for the case where upgrading
981the regex to utf8 is necessary but that isn't known when the compilation begins.
df91d470 982
fa232254 983=head2 String appending is 100 times faster
df91d470 984
fa232254
FC
985When doing a lot of string appending, perl could end up allocating a lot more
986memory than needed in a very inefficient way, if perl was configured to use the
987system's C<malloc> implementation instead of its own.
988
989C<sv_grow>, which is what's being used to allocate more memory if necessary
990when appending to a string, has now been taught how to round up the memory
991it requests to a certain geometric progression, making it much faster on
992certain platforms and configurations. On Win32, it's now about 100 times
993faster.
994
995=head2 Eliminate C<PL_*> accessor functions under ithreads
996
997When C<MULTIPLICITY> was first developed, and interpreter state moved into
998an interpreter struct, thread and interpreter local C<PL_*> variables were
999defined as macros that called accessor functions, returning the address of
1000the value, outside of the perl core. The intent was to allow members
1001within the interpreter struct to change size without breaking binary
1002compatibility, so that bug fixes could be merged to a maintenance branch
1003that necessitated such a size change.
1004
1005However, some non-core code defines C<PERL_CORE>, sometimes intentionally
1006to bypass this mechanism for speed reasons, sometimes for other reasons but
1007with the inadvertent side effect of bypassing this mechanism. As some of
1008this code is widespread in production use, the result is that the core
1009I<can't> change the size of members of the interpreter struct, as it will
1010break such modules compiled against a previous release on that maintenance
1011branch. The upshot is that this mechanism is redundant, and well-behaved
1012code is penalised by it. Hence it can and should be removed (and has
1013been).
1014
1015=head2 Freeing weak references
1016
1017When an object has many weak references to it, freeing that object
1018can under some some circumstances take O(N^2) time to free (where N is the
1019number of references). The number of circumstances has been reduced
1020[perl #75254]
1021
1022=head2 Lexical array and hash assignments
1023
1024An earlier optimisation to speed up C<my @array = ...> and
1025C<my %hash = ...> assignments caused a bug and was disabled in Perl 5.12.0.
1026
1027Now we have found another way to speed up these assignments [perl #82110].
df91d470 1028
111b6aa7 1029=head2 C<@_> uses less memory
df91d470 1030
111b6aa7
FC
1031Previously, C<@_> was allocated for every subroutine at compile time with
1032enough space for four entries. Now this allocation is done on demand when
1033the subroutine is called [perl #72416].
5076a392 1034
5076a392
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1035=head2 Size optimisations to SV and HV structures
1036
1037xhv_fill has been eliminated from struct xpvhv, saving 1 IV per hash and
111b6aa7 1038on some systems will cause struct xpvhv to become cache-aligned. To avoid
5076a392
FC
1039this memory saving causing a slowdown elsewhere, boolean use of HvFILL
1040now calls HvTOTALKEYS instead (which is equivalent) - so while the fill
111b6aa7
FC
1041data when actually required are now calculated on demand, the cases when
1042this needs to be done should be few and far between.
5076a392 1043
111b6aa7
FC
1044The order of structure elements in SV bodies has changed. Effectively,
1045the NV slot has swapped location with STASH and MAGIC. As all access to
1046SV members is via macros, this should be completely transparent. This
5076a392
FC
1047change allows the space saving for PVHVs documented above, and may reduce
1048the memory allocation needed for PVIVs on some architectures.
1049
fa232254
FC
1050C<XPV>, C<XPVIV>, and C<XPVNV> now only allocate the parts of the C<SV> body
1051they actually use, saving some space.
5076a392 1052
fa232254
FC
1053Scalars containing regular expressions now only allocate the part of the C<SV>
1054body they actually use, saving some space.
5076a392
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1055
1056=head2 Memory consumption improvements to Exporter
1057
1058The @EXPORT_FAIL AV is no longer created unless required, hence neither is
111b6aa7
FC
1059the typeglob backing it. This saves about 200 bytes for every package that
1060uses Exporter but doesn't use this functionality.
5076a392 1061
111b6aa7 1062=head2 Memory savings for weak references
5076a392
FC
1063
1064For weak references, the common case of just a single weak reference per
1065referent has been optimised to reduce the storage required. In this case it
111b6aa7 1066saves the equivalent of one small Perl array per referent.
5076a392 1067
111b6aa7 1068=head2 C<%+> and C<%-> use less memory
5076a392
FC
1069
1070The bulk of the C<Tie::Hash::NamedCapture> module used to be in the perl
111b6aa7 1071core. It has now been moved to an XS module, to reduce the overhead for
5076a392
FC
1072programs that do not use C<%+> or C<%->.
1073
fa232254 1074=head2 Multiple small improvements to threads
5076a392 1075
fa232254
FC
1076The internal structures of threading now make fewer API calls and fewer
1077allocations, resulting in noticeably smaller object code. Additionally,
1078many thread context checks have been deferred so that they're only done
1079when required (although this is only possible for non-debugging builds).
5076a392 1080
fa232254 1081=head2 Adjacent pairs of nextstate opcodes are now optimized away
5076a392 1082
fa232254 1083Previously, in code such as
5076a392 1084
fa232254 1085 use constant DEBUG => 0;
5076a392 1086
fa232254
FC
1087 sub GAK {
1088 warn if DEBUG;
1089 print "stuff\n";
1090 }
5076a392 1091
fa232254
FC
1092the ops for C<warn if DEBUG;> would be folded to a C<null> op (C<ex-const>), but
1093the C<nextstate> op would remain, resulting in a runtime op dispatch of
1094C<nextstate>, C<nextstate>, ....
5076a392 1095
fa232254
FC
1096The execution of a sequence of C<nextstate> ops is indistinguishable from just
1097the last C<nextstate> op so the peephole optimizer now eliminates the first of
1098a pair of C<nextstate> ops, except where the first carries a label, since labels
1099must not be eliminated by the optimizer and label usage isn't conclusively known
1100at compile time.
5076a392
FC
1101
1102=head1 Modules and Pragmata
1103
1104=head2 New Modules and Pragmata
1105
1106=over 4
1107
1108=item *
1109
1110C<CPAN::Meta::YAML> 0.003 has been added as a dual-life module. It supports a
1111subset of YAML sufficient for reading and writing META.yml and MYMETA.yml files
1112included with CPAN distributions or generated by the module installation
1113toolchain. It should not be used for any other general YAML parsing or
1114generation task.
1115
1116=item *
1117
1118C<CPAN::Meta> version 2.110440 has been added as a dual-life module. It
1119provides a standard library to read, interpret and write CPAN distribution
1120metadata files (e.g. META.json and META.yml) which describes a
1121distribution, its contents, and the requirements for building it and
1122installing it. The latest CPAN distribution metadata specification is
1123included as C<CPAN::Meta::Spec> and notes on changes in the specification
1124over time are given in C<CPAN::Meta::History>.
1125
1126=item *
1127
5a553547 1128C<HTTP::Tiny> 0.011 has been added as a dual-life module. It is a very
5076a392
FC
1129small, simple HTTP/1.1 client designed for simple GET requests and file
1130mirroring. It has has been added to enable CPAN.pm and CPANPLUS to
1131"bootstrap" HTTP access to CPAN using pure Perl without relying on external
1132binaries like F<curl> or F<wget>.
1133
1134=item *
1135
1136C<JSON::PP> 2.27105 has been added as a dual-life module, for the sake of
1137reading F<META.json> files in CPAN distributions.
1138
1139=item *
1140
21ef4e45 1141C<Module::Metadata> 1.000004 has been added as a dual-life module. It gathers
5076a392
FC
1142package and POD information from Perl module files. It is a standalone module
1143based on Module::Build::ModuleInfo for use by other module installation
1144toolchain components. Module::Build::ModuleInfo has been deprecated in
1145favor of this module instead.
1146
1147=item *
1148
1149C<Perl::OSType> 1.002 has been added as a dual-life module. It maps Perl
1150operating system names (e.g. 'dragonfly' or 'MSWin32') to more generic types
1151with standardized names (e.g. "Unix" or "Windows"). It has been refactored
1152out of Module::Build and ExtUtils::CBuilder and consolidates such mappings into
1153a single location for easier maintenance.
1154
1155=item *
1156
1157The following modules were added by the C<Unicode::Collate>
1158upgrade. See below for details.
1159
1160C<Unicode::Collate::CJK::Big5>
1161
1162C<Unicode::Collate::CJK::GB2312>
1163
1164C<Unicode::Collate::CJK::JISX0208>
1165
1166C<Unicode::Collate::CJK::Korean>
1167
1168C<Unicode::Collate::CJK::Pinyin>
1169
1170C<Unicode::Collate::CJK::Stroke>
1171
1172=item *
1173
1174C<Version::Requirements> version 0.101020 has been added as a dual-life
1175module. It provides a standard library to model and manipulates module
1176prerequisites and version constraints as defined in the L<CPAN::Meta::Spec>.
1177
1178=back
1179
a5794e94 1180=head2 Updated Modules and Pragma
5076a392
FC
1181
1182=over 4
1183
1184=item *
1185
81a53be2
FR
1186C<attributes> has been upgraded from version 0.12 to 0.14.
1187
1188=item *
1189
5076a392
FC
1190C<Archive::Extract> has been upgraded from version 0.38 to 0.48.
1191
1192Updates since 0.38 include: a safe print method that guards
1193Archive::Extract from changes to $\; a fix to the tests when run in core
1984204c
FC
1194perl; support for TZ files; a modification for the lzma
1195logic to favour IO::Uncompress::Unlzma; and a fix
1196for an issue with NetBSD-current and its new unzip
5076a392
FC
1197executable.
1198
1199=item *
1200
1201C<Archive::Tar> has been upgraded from version 1.54 to 1.76.
1202
1984204c
FC
1203Important changes since 1.54 include the following:
1204
1205=over
1206
1207=item *
1208
1209Compatibility with busybox implementations of tar
1210
1211=item *
1212
1213A fix so that C<write()> and C<create_archive()>
1214close only handles they opened
1215
1216=item *
1217
1218A bug was fixed regarding the exit code of extract_archive.
5076a392 1219
1984204c
FC
1220=item *
1221
4f978a3b 1222The C<ptar> utility has a new option to allow safe
5076a392
FC
1223creation of tarballs without world-writable files on Windows, allowing those
1224archives to be uploaded to CPAN.
1225
1984204c
FC
1226=item *
1227
1228A new ptargrep utility for using regular expressions against
5076a392
FC
1229the contents of files in a tar archive.
1230
1984204c
FC
1231=item *
1232
1233Pax extended headers are now skipped.
1234
1235=back
5076a392
FC
1236
1237=item *
1238
fcd5df6d
FR
1239C<Attribute::Handlers> has been upgraded from version 0.87 to 0.89.
1240
1241=item *
1242
3f5a47e4
FR
1243C<autodie> has been upgraded from version 2.06_01 to 2.1001.
1244
1245=item *
1246
578e7c9d
FR
1247C<AutoLoader> has been upgraded from version 5.70 to 5.71.
1248
1249=item *
1250
a13baafd 1251C<B> has been upgraded from version 1.23 to 1.29.
5076a392
FC
1252
1253It no longer crashes when taking apart a C<y///> containing characters
1254outside the octet range or compiled in a C<use utf8> scope.
1255
1256The size of the shared object has been reduced by about 40%, with no
1257reduction in functionality.
1258
1259=item *
1260
4a75fbf5 1261C<B::Concise> has been upgraded from version 0.78 to 0.83.
5076a392
FC
1262
1263B::Concise marks rv2sv, rv2av and rv2hv ops with the new OPpDEREF flag
1264as "DREFed".
1265
1266It no longer produces mangled output with the C<-tree> option
1267[perl #80632].
1268
1269=item *
1270
6bb8c1e3
FR
1271C<B::Debug> has been upgraded from version 1.12 to 1.16.
1272
1273=item *
1274
c67a4e29 1275C<B::Deparse> has been upgraded from version 0.96 to 1.03.
5076a392 1276
1984204c 1277The deparsing of a nextstate op has changed when it has both a
5076a392
FC
1278change of package (relative to the previous nextstate), or a change of
1279C<%^H> or other state, and a label. Previously the label was emitted
cdc10f43 1280first, but now the label is emitted last (5.12.1).
5076a392 1281
5a553547
FC
1282The C<no 5.13.2> or similar form is now correctly handled by B::Deparse
1283(5.12.3).
5076a392
FC
1284
1285B::Deparse now properly handles the code that applies a conditional
1286pattern match against implicit C<$_> as it was fixed in [perl #20444].
1287
1984204c
FC
1288Deparsing of C<our> followed by a variable with funny characters
1289(as permitted under the C<utf8> pragma) has also been fixed [perl #33752].
5076a392
FC
1290
1291=item *
1292
d97c5d3b
FR
1293C<B::Lint> has been upgraded from version 1.11_01 to 1.13.
1294
1295=item *
1296
5aef2c44
FR
1297C<base> has been upgraded from version 2.15 to 2.16.
1298
1299=item *
1300
876607aa
FR
1301C<Benchmark> has been upgraded from version 1.11 to 1.12.
1302
1303=item *
1304
e539ae69
FR
1305C<bignum> has been upgraded from version 0.23 to 0.26.
1306
1307=item *
1308
c74c1fa8 1309C<Carp> has been upgraded from version 1.15 to 1.20.
5076a392
FC
1310
1311L<Carp> now detects incomplete L<caller()|perlfunc/"caller EXPR"> overrides and
d430b8e7
FC
1312avoids using bogus C<@DB::args>. To provide backtraces,
1313Carp relies on particular behaviour of the C<caller>
1314built-in. Carp now detects if other code has
5076a392 1315overridden this with an incomplete implementation, and modifies its backtrace
d430b8e7
FC
1316accordingly. Previously incomplete overrides would cause incorrect values
1317in backtraces (best case), or obscure fatal errors (worst case).
5076a392
FC
1318
1319This fixes certain cases of C<Bizarre copy of ARRAY> caused by modules
d430b8e7 1320overriding C<caller()> incorrectly (5.12.2).
5076a392 1321
1984204c 1322It now also avoids using regular expressions that cause perl to
5076a392
FC
1323load its Unicode tables, in order to avoid the 'BEGIN not safe after
1324errors' error that will ensue if there has been a syntax error
1325[perl #82854].
1326
1327=item *
1328
9eb7ad55 1329C<CGI> has been upgraded from version 3.48 to 3.52.
5076a392
FC
1330
1331This provides the following security fixes: the MIME boundary in
1984204c
FC
1332multipart_init is now random and the handling of
1333newlines embedded in header values has been improved.
5076a392
FC
1334
1335=item *
1336
5076a392
FC
1337C<Compress::Raw::Bzip2> has been upgraded from version 2.024 to 2.033.
1338
1984204c 1339It has been updated to use bzip2 1.0.6.
5076a392
FC
1340
1341=item *
1342
51090521
FR
1343C<Compress::Raw::Zlib> has been upgraded from version 2.024 to 2.033.
1344
1345=item *
1346
f75b7efc 1347C<CPAN> has been upgraded from version 1.94_56 to 1.9600.
1984204c
FC
1348
1349Major highlights:
5076a392
FC
1350
1351=over 4
1352
1984204c 1353=item * much less configuration dialog hassle
5076a392 1354
1984204c 1355=item * support for META/MYMETA.json
5076a392 1356
1984204c 1357=item * support for local::lib
5076a392 1358
1984204c 1359=item * support for HTTP::Tiny to reduce the dependency on ftp sites
5076a392 1360
1984204c 1361=item * automatic mirror selection
5076a392 1362
1984204c 1363=item * iron out all known bugs in configure_requires
5076a392 1364
1984204c
FC
1365=item * support for distributions compressed with bzip2
1366
1367=item * allow Foo/Bar.pm on the commandline to mean Foo::Bar
1368
1369=back
5076a392
FC
1370
1371=item *
1372
d430b8e7
FC
1373C<CPANPLUS> has been upgraded from version 0.90 to 0.9103.
1374
1375A change to F<cpanp-run-perl>
1376resolves L<RT #55964|http://rt.cpan.org/Public/Bug/Display.html?id=55964>
1377and L<RT #57106|http://rt.cpan.org/Public/Bug/Display.html?id=57106>, both
1378of which related to failures to install distributions that use
1379C<Module::Install::DSL> (5.12.2).
5076a392 1380
1984204c
FC
1381A dependency on Config was not recognised as a
1382core module dependency. This has been fixed.
5076a392 1383
1984204c 1384CPANPLUS now includes support for META.json and MYMETA.json.
5076a392
FC
1385
1386=item *
1387
4467e8f7
FR
1388C<CPANPLUS::Dist::Build> has been upgraded from version 0.46 to 0.54.
1389
1390=item *
1391
5076a392
FC
1392C<Data::Dumper> has been upgraded from version 2.125 to 2.130_02.
1393
4ed2cea4
FC
1394The indentation used to be off when C<$Data::Dumper::Terse> was set. This
1395has been fixed [perl #73604].
1396
1984204c
FC
1397This upgrade also fixes a crash when using custom sort functions that might
1398cause the stack to change [perl #74170].
5076a392
FC
1399
1400C<Dumpxs> no longer crashes with globs returned by C<*$io_ref>
1401[perl #72332].
1402
1403=item *
1404
549d34f5
FR
1405C<DB_File> has been upgraded from version 1.820 to 1.821.
1406
1407=item *
1408
851dbda2
FR
1409C<DBM_Filter> has been upgraded from version 0.03 to 0.04.
1410
1411=item *
1412
5076a392
FC
1413C<Devel::DProf> has been upgraded from version 20080331.00 to 20110228.00.
1414
1415Merely loading C<Devel::DProf> now no longer triggers profiling to start.
1416C<use Devel::DProf> and C<perl -d:DProf ...> still behave as before and start
1417the profiler.
1418
1419NOTE: C<Devel::DProf> is deprecated and will be removed from a future
1984204c 1420version of Perl. We strongly recommend that you install and use
5076a392
FC
1421L<Devel::NYTProf> instead, as it offers significantly improved
1422profiling and reporting.
1423
1424=item *
1425
868625d2
FR
1426C<Devel::Peek> has been upgraded from version 1.04 to 1.07.
1427
1428=item *
1429
66899ca3
FR
1430C<Devel::SelfStubber> has been upgraded from version 1.03 to 1.05.
1431
1432=item *
1433
5076a392
FC
1434C<diagnostics> has been upgraded from version 1.19 to 1.22.
1435
1436It now renders pod links slightly better, and has been taught to find
1437descriptions for messages that share their descriptions with other
1438messages.
1439
1440=item *
1441
1442C<Digest::MD5> has been upgraded from version 2.39 to 2.51.
1443
1444It is now safe to use this module in combination with threads.
1445
1446=item *
1447
1448C<Digest::SHA> has been upgraded from version 5.47 to 5.61.
1449
1450C<shasum> now more closely mimics C<sha1sum>/C<md5sum>.
1451
1452C<Addfile> accepts all POSIX filenames.
1453
1984204c
FC
1454New SHA-512/224 and SHA-512/256 transforms (ref. NIST Draft FIPS 180-4
1455[February 2011])
5076a392
FC
1456
1457=item *
1458
88410521
FR
1459C<DirHandle> has been upgraded from version 1.03 to 1.04.
1460
1461=item *
1462
e53cbaa3
FR
1463C<Dumpvalue> has been upgraded from version 1.13 to 1.16.
1464
1465=item *
1466
31e8b85a 1467C<DynaLoader> has been upgraded from version 1.10 to 1.13.
5076a392
FC
1468
1469It fixes a buffer overflow when passed a very long file name.
1470
1471It no longer inherits from AutoLoader; hence it no longer
1472produces weird error messages for unsuccessful method calls on classes that
1473inherit from DynaLoader [perl #84358].
1474
1475=item *
1476
1477C<Encode> has been upgraded from version 2.39 to 2.42.
1478
1479Now, all 66 Unicode non-characters are treated the same way U+FFFF has
1984204c
FC
1480always been treated; in cases when it was disallowed, all 66 are
1481disallowed; in those cases where it warned, all 66 warn.
5076a392
FC
1482
1483=item *
1484
68f90ac3
FR
1485C<Env> has been upgraded from version 1.01 to 1.02.
1486
1487=item *
1488
5076a392
FC
1489C<Errno> has been upgraded from version 1.11 to 1.13.
1490
1491The implementation of C<Errno> has been refactored to use about 55% less memory.
5076a392
FC
1492
1493On some platforms with unusual header files, like Win32/gcc using mingw64
1494headers, some constants which weren't actually error numbers have been exposed
1495by C<Errno>. This has been fixed [perl #77416].
1496
1497=item *
1498
1499C<Exporter> has been upgraded from version 5.64_01 to 5.64_03.
1500
1501Exporter no longer overrides C<$SIG{__WARN__}> [perl #74472]
1502
1503=item *
1504
25fe7f8f
FR
1505C<ExtUtils::CBuilder> has been upgraded from version 0.27 to 0.280202.
1506
1507=item *
1508
2292e71e
FR
1509C<ExtUtils::Command> has been upgraded from version 1.16 to 1.17.
1510
1511=item *
1512
5076a392
FC
1513C<ExtUtils::Constant> has been upgraded from 0.22 to 0.23.
1514
1515The C<AUTOLOAD> helper code generated by C<ExtUtils::Constant::ProxySubs>
1516can now C<croak> for missing constants, or generate a complete C<AUTOLOAD>
1984204c
FC
1517subroutine in XS, allowing simplification of many modules that use it
1518(C<Fcntl>, C<File::Glob>, C<GDBM_File>, C<I18N::Langinfo>, C<POSIX>,
1519C<Socket>).
5076a392
FC
1520
1521C<ExtUtils::Constant::ProxySubs> can now optionally push the names of all
1984204c 1522constants onto the package's C<@EXPORT_OK>.
5076a392
FC
1523
1524=item *
1525
588c5853
FR
1526C<ExtUtils::Install> has been upgraded from version 1.55 to 1.56.
1527
1528=item *
1529
5418ffb3
FR
1530C<ExtUtils::MakeMaker> has been upgraded from version 6.56 to 6.57_05.
1531
1532=item *
1533
f40ab45f
FR
1534C<ExtUtils::Manifest> has been upgraded from version 1.57 to 1.58.
1535
1536=item *
1537
10fb15d2 1538C<ExtUtils::ParseXS> has been upgraded from version 2.21 to 2.2210.
b7064dd7
FR
1539
1540=item *
1541
8b87be80 1542C<Fcntl> has been upgraded from version 1.06 to 1.11.
26f7fa64
FR
1543
1544=item *
1545
1546C<File::Basename> has been upgraded from version 2.78 to 2.81.
8b87be80
FR
1547
1548=item *
1549
05102622
FR
1550C<File::CheckTree> has been upgraded from version 4.4 to 4.41.
1551
1552=item *
1553
65d78858
FR
1554C<File::Copy> has been upgraded from version 2.17 to 2.21.
1555
1556=item *
1557
e12786fa 1558C<File::DosGlob> has been upgraded from version 1.01 to 1.04.
5076a392
FC
1559
1560It allows patterns containing literal parentheses (they no longer need to
1984204c
FC
1561be escaped). On Windows, it no longer
1562adds an extra F<./> to the file names
5076a392
FC
1563returned when the pattern is a relative glob with a drive specification,
1564like F<c:*.pl> [perl #71712].
1565
1566=item *
1567
1568C<File::Fetch> has been upgraded from version 0.24 to 0.32.
1569
1570C<HTTP::Lite> is now supported for 'http' scheme.
1571
1572The C<fetch> utility is supported on FreeBSD, NetBSD and
1573Dragonfly BSD for the C<http> and C<ftp> schemes.
1574
1575=item *
1576
23f2cbb1 1577C<File::Find> has been upgraded from version 1.15 to 1.19.
5076a392 1578
1984204c 1579It improves handling of backslashes on Windows, so that paths like
5076a392
FC
1580F<c:\dir\/file> are no longer generated [perl #71710].
1581
1582=item *
1583
0ae9f678
FR
1584C<File::Glob> has been upgraded from version 1.07 to 1.12.
1585
1586=item *
1587
d430b8e7
FC
1588C<File::Spec> has been upgraded from version 3.31 to 3.33.
1589
1590Several portability fixes were made in C<File::Spec::VMS>: a colon is now
1591recognized as a delimiter in native filespecs; caret-escaped delimiters are
1592recognized for better handling of extended filespecs; C<catpath()> returns
1593an empty directory rather than the current directory if the input directory
1594name is empty; C<abs2rel()> properly handles Unix-style input (5.12.2).
1595
1596=item *
1597
46ba0657 1598C<File::stat> has been upgraded from 1.02 to 1.05.
5076a392
FC
1599
1600The C<-x> and C<-X> file test operators now work correctly under the root
1601user.
1602
1603=item *
1604
b7edcc3c
FR
1605C<Filter::Simple> has been upgraded from version 0.84 to 0.86.
1606
1607=item *
1608
dc6857fd 1609C<GDBM_File> has been upgraded from 1.10 to 1.14.
5076a392
FC
1610
1611This fixes a memory leak when DBM filters are used.
1612
1613=item *
1614
6e107b45 1615C<Hash::Util> has been upgraded from 0.07 to 0.11.
5076a392 1616
1984204c
FC
1617Hash::Util no longer emits spurious "uninitialized" warnings when
1618recursively locking hashes that have undefined values [perl #74280].
5076a392
FC
1619
1620=item *
1621
89ce9b34
FR
1622C<Hash::Util::FieldHash> has been upgraded from version 1.04 to 1.09.
1623
1624=item *
1625
eec33fe6
FR
1626C<I18N::Collate> has been upgraded from version 1.01 to 1.02.
1627
1628=item *
1629
ad5f8f47 1630C<I18N::Langinfo> has been upgraded from version 0.03 to 0.08.
5076a392
FC
1631
1632C<langinfo()> now defaults to using C<$_> if there is no argument given, just
5334145a 1633as the documentation has always claimed.
5076a392
FC
1634
1635=item *
1636
c41635f7
FR
1637C<I18N::LangTags> has been upgraded from version 0.35 to 0.35_01.
1638
1639=item *
1640
98a6a4ff
FR
1641C<if> has been upgraded from version 0.05 to 0.0601.
1642
1643=item *
1644
f6ff7fb6
FR
1645C<IO> has been upgraded from version 1.25_02 to 1.25_04.
1646
582bf58c
FR
1647This version of C<IO> includes a new C<IO::Select>, which now allows IO::Handle
1648objects (and objects in derived classes) to be removed from an IO::Select set
1649even if the underlying file descriptor is closed or invalid.
5076a392
FC
1650
1651=item *
1652
d07561d3 1653C<IPC::Cmd> has been upgraded from version 0.54 to 0.70.
5076a392 1654
1984204c
FC
1655Resolves an issue with splitting Win32 command lines. An argument
1656consisting of the single character "0" used to be omitted (CPAN RT #62961).
5076a392
FC
1657
1658=item *
1659
3f16e4eb 1660C<IPC::Open3> has been upgraded from 1.05 to 1.09.
5076a392 1661
4ed2cea4
FC
1662C<open3> now produces an error if the C<exec> call fails, allowing this
1663condition to be distinguished from a child process that exited with a
1664non-zero status [perl #72016].
1665
5076a392
FC
1666The internal C<xclose> routine now knows how to handle file descriptors, as
1667documented, so duplicating STDIN in a child process using its file
1668descriptor now works [perl #76474].
1669
1670=item *
1671
c8b41807
FR
1672C<IPC::SysV> has been upgraded from version 2.01 to 2.03.
1673
1674=item *
1675
ef79f038
FR
1676C<lib> has been upgraded from version 0.62 to 0.63.
1677
1678=item *
1679
5b1884f4 1680C<Locale::Maketext> has been upgraded from version 1.14 to 1.19.
5076a392 1681
1984204c 1682Locale::Maketext now supports external caches.
5076a392 1683
1984204c
FC
1684This upgrade also fixes an infinite loop in
1685C<Locale::Maketext::Guts::_compile()> when
5076a392
FC
1686working with tainted values (CPAN RT #40727).
1687
1984204c 1688C<< ->maketext >> calls will now back up and restore C<$@> so that error
5076a392
FC
1689messages are not suppressed (CPAN RT #34182).
1690
1691=item *
1692
3811bd2b
FR
1693C<Log::Message> has been upgraded from version 0.02 to 0.04.
1694
1695=item *
1696
8eb65377
FR
1697C<Log::Message::Simple> has been upgraded from version 0.06 to 0.08.
1698
1699=item *
1700
5076a392
FC
1701C<Math::BigInt> has been upgraded from version 1.89_01 to 1.994.
1702
1703This fixes, among other things, incorrect results when computing binomial
1704coefficients [perl #77640].
1705
1984204c 1706It also prevents C<sqrt($int)> from crashing under C<use bigrat;>
5076a392
FC
1707[perl #73534].
1708
1709=item *
1710
846c1cec
FR
1711C<Math::BigInt::FastCalc> has been upgraded from version 0.19 to 0.28.
1712
1713=item *
1714
fce4aef3
FR
1715C<Math::BigRat> has been upgraded from version 0.24 to 0.26_02.
1716
1717=item *
1718
12e26027
FR
1719C<Memoize> has been upgraded from version 1.01_03 to 1.02.
1720
1721=item *
1722
5076a392
FC
1723C<MIME::Base64> has been upgraded from 3.08 to 3.13.
1724
1725Includes new functions to calculate the length of encoded and decoded
1726base64 strings.
1727
1728Now provides C<encode_base64url> and C<decode_base64url> functions to process
1729the base64 scheme for "URL applications".
1730
1731=item *
1732
1733C<Module::Build> has been upgraded from version 0.3603 to 0.3800.
1734
1735A notable change is the deprecation of several modules.
1736Module::Build::Version has been deprecated and Module::Build now relies
1737directly upon L<version>. Module::Build::ModuleInfo has been deprecated in
1738favor of a standalone copy of it called L<Module::Metadata>.
1739Module::Build::YAML has been deprecated in favor of L<CPAN::Meta::YAML>.
1740
1741Module::Build now also generates META.json and MYMETA.json files
1742in accordance with version 2 of the CPAN distribution metadata specification,
1743L<CPAN::Meta::Spec>. The older format META.yml and MYMETA.yml files are
1744still generated, as well.
1745
1746=item *
1747
7259fe26 1748C<Module::CoreList> has been upgraded from version 2.29 to 2.47.
5076a392
FC
1749
1750Besides listing the updated core modules of this release, it also stops listing
1984204c 1751the C<Filespec> module. That module never existed in core. The scripts
5076a392 1752generating C<Module::CoreList> confused it with C<VMS::Filespec>, which actually
1984204c 1753is a core module as of perl 5.8.7.
5076a392
FC
1754
1755=item *
1756
193af05b
FR
1757C<Module::Load> has been upgraded from version 0.16 to 0.18.
1758
1759=item *
1760
5b3a054f
FR
1761C<Module::Load::Conditional> has been upgraded from version 0.34 to 0.44.
1762
1763=item *
1764
01835e3a
FR
1765C<mro> has been upgraded from version 1.02 to 1.07.
1766
1767=item *
1768
bfe7bf96 1769C<NDBM_File> has been upgraded from version 1.08 to 1.12.
4f978a3b
FR
1770
1771This fixes a memory leak when DBM filters are used.
1772
1773=item *
1774
d0aa5c91
FR
1775C<Net::Ping> has been upgraded from version 2.36 to 2.38.
1776
1777=item *
1778
d44b8a8c
FR
1779C<NEXT> has been upgraded from version 0.64 to 0.65.
1780
1781=item *
1782
678d4fd4
FR
1783C<Object::Accessor> has been upgraded from version 0.36 to 0.38.
1784
1785=item *
1786
34188656 1787C<ODBM_File> have been upgraded from version 1.07 to 1.10.
5076a392
FC
1788
1789This fixes a memory leak when DBM filters are used.
1790
1791=item *
1792
4c69840c
FR
1793C<Opcode> has been upgraded from version 1.15 to 1.18.
1794
1795=item *
1796
f4c5ae54 1797C<overload> has been upgraded from 1.10 to 1.13.
5076a392
FC
1798
1799C<overload::Method> can now handle subroutines that are themselves blessed
1800into overloaded classes [perl #71998].
1801
5076a392
FC
1802The documentation has greatly improved. See L</Documentation> below.
1803
1804=item *
1805
f84c796e
FR
1806C<Params::Check> has been upgraded from version 0.26 to 0.28.
1807
1808=item *
1809
550ee92b
FR
1810C<parent> has been upgraded from version 0.223 to 0.225.
1811
1812=item *
1813
5076a392
FC
1814C<Parse::CPAN::Meta> has been upgraded from version 1.40 to 1.4401.
1815
1984204c 1816The latest Parse::CPAN::Meta can now read YAML and JSON files using
5076a392
FC
1817L<CPAN::Meta::YAML> and L<JSON::PP>, which are now part of the Perl core.
1818
1819=item *
1820
e981cf86
FR
1821C<PerlIO::encoding> has been upgraded from version 0.12 to 0.14.
1822
1823=item *
1824
5076a392
FC
1825C<PerlIO::scalar> has been upgraded from 0.07 to 0.11.
1826
1827A C<read> after a C<seek> beyond the end of the string no longer thinks it
1828has data to read [perl #78716].
1829
1830=item *
1831
776f733b
FR
1832C<PerlIO::via> has been upgraded from version 0.09 to 0.11.
1833
1834=item *
1835
ae9456cc
FR
1836C<Pod::Html> has been upgraded from version 1.09 to 1.1.
1837
1838=item *
1839
be3c8498
FR
1840C<Pod::LaTeX> has been upgraded from version 0.58 to 0.59.
1841
1842=item *
1843
fd8a2e89
FR
1844C<Pod::Perldoc> has been upgraded from version 3.15_02 to 3.15_03.
1845
1846=item *
1847
5bcb6583
FR
1848C<Pod::Simple> has been upgraded from version 3.13 to 3.16.
1849
1850=item *
1851
abb8c779 1852C<POSIX> has been upgraded from 1.19 to 1.24.
5076a392
FC
1853
1854It now includes constants for POSIX signal constants.
1855
1856=item *
1857
1984204c 1858C<re> has been upgraded from version 0.11 to 0.17.
5076a392
FC
1859
1860New C<use re "/flags"> pragma
1861
5076a392 1862The C<regmust> function used to crash when called on a regular expression
1984204c 1863belonging to a pluggable engine. Now it croaks instead.
5076a392
FC
1864
1865C<regmust> no longer leaks memory.
1866
1867=item *
1868
1869C<Safe> has been upgraded from version 2.25 to 2.29.
1870
cdc10f43
FC
1871Coderefs returned by C<reval()> and C<rdo()> are now wrapped via
1872C<wrap_code_refs> (5.12.1).
1873
5076a392
FC
1874This fixes a possible infinite loop when looking for coderefs.
1875
cdc10f43 1876It adds several version::vxs::* routines to the default share.
5076a392
FC
1877
1878=item *
1879
2c19fa42
FR
1880C<SDBM_File> has been upgraded from version 1.06 to 1.09.
1881
1882=item *
1883
5076a392
FC
1884C<SelfLoader> has been upgraded from 1.17 to 1.18.
1885
1886It now works in taint mode [perl #72062].
1887
1888=item *
1889
1890C<sigtrap> has been upgraded from version 1.04 to 1.05.
1891
1892It no longer tries to modify read-only arguments when generating a
1893backtrace [perl #72340].
1894
1895=item *
1896
1984204c 1897C<Socket> has been upgraded from version 1.87 to 1.94.
5076a392 1898
1984204c 1899See L</IPv6 support>, above.
5076a392
FC
1900
1901=item *
1902
1903C<Storable> has been upgraded from version 2.22 to 2.27.
1904
1905Includes performance improvement for overloaded classes.
1906
5076a392 1907This adds support for serialising code references that contain UTF-8 strings
1984204c
FC
1908correctly. The Storable minor version
1909number changed as a result, meaning that
5076a392
FC
1910Storable users who set C<$Storable::accept_future_minor> to a C<FALSE> value
1911will see errors (see L<Storable/FORWARD COMPATIBILITY> for more details).
1912
1913Freezing no longer gets confused if the Perl stack gets reallocated
1914during freezing [perl #80074].
1915
1916=item *
1917
648c3d7d
FR
1918C<Sys::Hostname> has been upgraded from version 1.11 to 1.16.
1919
1920=item *
1921
90c6e78f
FR
1922C<Term::ANSIColor> has been upgraded from version 2.02 to 3.00.
1923
1924=item *
1925
d9f2f059
FR
1926C<Term::UI> has been upgraded from version 0.20 to 0.26.
1927
1928=item *
1929
80ebb519
FR
1930C<Test::Harness> has been upgraded from version 3.17 to 3.23.
1931
1932=item *
1933
5076a392
FC
1934C<Test::Simple> has been upgraded from version 0.94 to 0.98.
1935
1936Among many other things, subtests without a C<plan> or C<no_plan> now have an
1937implicit C<done_testing()> added to them.
1938
1939=item *
1940
5076a392
FC
1941C<Thread::Semaphore> has been upgraded from version 2.09 to 2.12.
1942
1984204c
FC
1943It provides two new methods that give more control over the decrementing of
1944semaphores: C<down_nb> and C<down_force>.
5076a392
FC
1945
1946=item *
1947
f0d895e1
FR
1948C<Thread::Queue> has been upgraded from version 2.11 to 2.12.
1949
1950=item *
1951
1a6b954e
FR
1952C<threads> has been upgraded from version 1.75 to 1.83.
1953
1954=item *
1955
55816daa
FR
1956C<threads::shared> has been upgraded from version 1.32 to 1.36.
1957
1958=item *
1959
5076a392
FC
1960C<Tie::Hash> has been upgraded from version 1.03 to 1.04.
1961
1962Calling C<< Tie::Hash-E<gt>TIEHASH() >> used to loop forever. Now it C<croak>s.
1963
1964=item *
1965
f2adc546
FR
1966C<Tie::Hash::NamedCapture> has been upgraded from version 0.06 to 0.08.
1967
1968=item *
1969
ed68b07e
FR
1970C<Tie::RefHash> has been upgraded from version 1.38 to 1.39.
1971
1972=item *
1973
bb3c221a
FR
1974C<Time::HiRes> has been upgraded from version 1.9719 to 1.9721_01.
1975
1976=item *
1977
97fa568b
FR
1978C<Time::Local> has been upgraded from version 1.1901_01 to 1.2000.
1979
1980=item *
1981
a83cb732
FR
1982C<Time::Piece> has been upgraded from version 1.15_01 to 1.20_01.
1983
1984=item *
1985
5076a392
FC
1986C<Unicode::Collate> has been upgraded from version 0.52_01 to 0.73.
1987
1984204c 1988Unicode::Collate has been updated to use Unicode 6.0.0.
5076a392 1989
1984204c
FC
1990Unicode::Collate::Locale now supports a plethora of new locales: ar, be,
1991bg, de__phonebook, hu, hy, kk, mk, nso, om, tn, vi, hr, ig, ja, ko, ru, sq,
1992se, sr, to, uk, zh, zh__big5han, zh__gb2312han, zh__pinyin and zh__stroke.
5076a392
FC
1993
1994The following modules have been added:
1995
1996C<Unicode::Collate::CJK::Big5> for C<zh__big5han> which makes
1997tailoring of CJK Unified Ideographs in the order of CLDR's big5han ordering.
1998
1999C<Unicode::Collate::CJK::GB2312> for C<zh__gb2312han> which makes
2000tailoring of CJK Unified Ideographs in the order of CLDR's gb2312han ordering.
2001
2002C<Unicode::Collate::CJK::JISX0208> which makes tailoring of 6355 kanji
2003(CJK Unified Ideographs) in the JIS X 0208 order.
2004
2005C<Unicode::Collate::CJK::Korean> which makes tailoring of CJK Unified Ideographs
2006in the order of CLDR's Korean ordering.
2007
2008C<Unicode::Collate::CJK::Pinyin> for C<zh__pinyin> which makes
2009tailoring of CJK Unified Ideographs in the order of CLDR's pinyin ordering.
2010
2011C<Unicode::Collate::CJK::Stroke> for C<zh__stroke> which makes
2012tailoring of CJK Unified Ideographs in the order of CLDR's stroke ordering.
2013
5076a392
FC
2014This also sees the switch from using the pure-perl version of this
2015module to the XS version.
2016
2017=item *
2018
ec52b54b
FR
2019C<Unicode::Normalize> has been upgraded from version 1.03 to 1.10.
2020
2021=item *
2022
5076a392
FC
2023C<Unicode::UCD> has been upgraded from version 0.27 to 0.32.
2024
1984204c
FC
2025A new function, C<Unicode::UCD::num()>, has been added. This function
2026returns the numeric value of the string passed it or C<undef> if the string
2027in its entirety has no "safe" numeric value. (For more detail, and for the
2028definition of "safe", see L<Unicode::UCD/num>.)
5076a392 2029
1984204c 2030This upgrade also includes a number of bug fixes:
5076a392
FC
2031
2032=over 4
2033
2034=item charinfo()
2035
2036=over 4
2037
2038=item *
2039
2040It is now updated to Unicode Version 6 with Corrigendum #8, except,
2041as with Perl 5.14, the code point at U+1F514 has no name.
2042
2043=item *
2044
2045The Hangul syllable code points have the correct names, and their
2046decompositions are always output without requiring L<Lingua::KO::Hangul::Util>
2047to be installed.
2048
2049=item *
2050
54c7bb16
FC
2051The CJK (Chinese-Japanese-Korean) code points U+2A700 to U+2B734
2052and U+2B740 to U+2B81D are now properly handled.
5076a392
FC
2053
2054=item *
2055
2056The numeric values are now output for those CJK code points that have them.
2057
2058=item *
2059
2060The names that are output for code points with multiple aliases are now the
2061corrected ones.
2062
2063=back
2064
2065=item charscript()
2066
2067This now correctly returns "Unknown" instead of C<undef> for the script
2068of a code point that hasn't been assigned another one.
2069
2070=item charblock()
2071
2072This now correctly returns "No_Block" instead of C<undef> for the block
2073of a code point that hasn't been assigned to another one.
2074
2075=back
2076
5076a392
FC
2077=item *
2078
2079C<version> has been upgraded from 0.82 to 0.88.
2080
1984204c 2081Due to a bug, now fixed, the C<is_strict> and C<is_lax> functions did not
cdc10f43 2082work when exported (5.12.1).
5076a392
FC
2083
2084=item *
2085
3e625598 2086C<warnings> has been upgraded from version 1.09 to 1.12.
5076a392
FC
2087
2088Calling C<use warnings> without arguments is now significantly more efficient.
2089
4f978a3b
FR
2090=item *
2091
2092C<warnings::register> have been upgraded from version 1.01 to 1.02.
2093
5076a392
FC
2094It is now possible to register warning categories other than the names of
2095packages using C<warnings::register>. See L<perllexwarn> for more information.
2096
2097=item *
2098
62e270c2
FR
2099C<XSLoader> has been upgraded from version 0.10 to 0.13.
2100
2101=item *
2102
5076a392
FC
2103C<VMS::DCLsym> has been upgraded from version 1.03 to 1.05.
2104
2105Two bugs have been fixed [perl #84086]:
2106
2107The symbol table name was lost when tying a hash, due to a thinko in
2108C<TIEHASH>. The result was that all tied hashes interacted with the
2109local symbol table.
2110
2111Unless a symbol table name had been explicitly specified in the call
2112to the constructor, querying the special key ':LOCAL' failed to
2113identify objects connected to the local symbol table.
2114
2115=item *
2116
2117C<Win32> has been upgraded from version 0.39 to 0.44.
2118
1984204c
FC
2119This release has several new functions: C<Win32::GetSystemMetrics>,
2120C<Win32::GetProductInfo>, C<Win32::GetOSDisplayName>.
5076a392 2121
1984204c
FC
2122The names returned by C<Win32::GetOSName> and C<Win32::GetOSDisplayName>
2123have been corrected.
5076a392 2124
3bbe5383
FR
2125=item *
2126
2127C<XS::Typemap> has been upgraded from version 0.03 to 0.05.
2128
5076a392
FC
2129=back
2130
5076a392
FC
2131=head2 Removed Modules and Pragmata
2132
2133The following modules have been removed from the core distribution, and if
2134needed should be installed from CPAN instead.
2135
2136=over
2137
4f978a3b
FR
2138=item *
2139
2140C<Class::ISA> has been removed from the Perl core. Prior version was 0.36.
5076a392 2141
4f978a3b
FR
2142=item *
2143
2144C<Pod::Plainer> has been removed from the Perl core. Prior version was 1.02.
2145
2146=item *
5076a392 2147
4f978a3b 2148C<Switch> has been removed from the Perl core. Prior version was 2.16.
5076a392
FC
2149
2150=back
2151
2152The removal of C<Shell> has been deferred until after 5.14, as the
2153implementation of C<Shell> shipped with 5.12.0 did not correctly issue the
2154warning that it was to be removed from core.
2155
2156=head1 Documentation
2157
5076a392
FC
2158=head2 New Documentation
2159
41e29def 2160=head3 L<perlgpl>
5076a392
FC
2161
2162L<perlgpl> has been updated to contain GPL version 1, as is included in the
cdc10f43 2163F<README> distributed with perl (5.12.1).
5076a392 2164
41e29def 2165=head3 Perl 5.12.x delta files
5076a392 2166
41e29def
FC
2167The perldelta files for Perl 5.12.1 to 5.12.3 have been added from the
2168maintenance branch: L<perl5121delta>, L<perl5122delta>, L<perl5123delta>.
5076a392
FC
2169
2170=head3 L<perlpodstyle>
2171
2172New style guide for POD documentation,
2173split mostly from the NOTES section of the pod2man man page.
2174
41e29def
FC
2175=head3 L<perlsource>, L<perlinterp>, L<perlhacktut>, and L<perlhacktips>
2176
cc13eef1 2177See L</perlhack and perlrepository revamp>, below.
5076a392
FC
2178
2179=head2 Changes to Existing Documentation
2180
41e29def 2181=head3 L<perlmodlib> is now complete
4ed2cea4
FC
2182
2183The perlmodlib page that came with Perl 5.12.0 was missing a lot of
2184modules, due to a bug in the script that generates the list. This has been
cdc10f43 2185fixed [perl #74332] (5.12.1).
4ed2cea4 2186
41e29def 2187=head3 Replace wrong tr/// table in L<perlebcdic>
5076a392 2188
41e29def 2189L<perlebcdic> contains a helpful table to use in tr/// to convert
5076a392
FC
2190between EBCDIC and Latin1/ASCII. Unfortunately, the table was the
2191inverse of the one it describes, though the code that used the table
2192worked correctly for the specific example given.
2193
2194The table has been changed to its inverse, and the sample code changed
2195to correspond, as this is easier for the person trying to follow the
2196instructions since deriving the old table is somewhat more complicated.
2197
2198The table has also been changed to hex from octal, as that is more the norm
2199these days, and the recipes in the pod altered to print out leading
41e29def 2200zeros to make all the values the same length.
5076a392 2201
41e29def 2202=head3 Tricks for user-defined casing
5076a392 2203
41e29def
FC
2204L<perlunicode> now contains an explanation of how to override, mangle
2205and otherwise tweak the way perl handles upper-, lower- and other-case
2206conversions on Unicode data, and how to provide scoped changes to alter
2207one's own code's behaviour without stomping on anybody else.
5076a392
FC
2208
2209=head3 INSTALL explicitly states the requirement for C89
2210
d430b8e7
FC
2211This was already true but it's now Officially Stated For The Record
2212(5.12.2).
5076a392 2213
41e29def 2214=head3 Explanation of C<\xI<HH>> and C<\oI<OOO>> escapes
5076a392 2215
41e29def
FC
2216L<perlop> has been updated with more detailed explanation of these two
2217character escapes.
5076a392 2218
41e29def 2219=head3 C<-0I<NNN>> switch
5076a392 2220
41e29def 2221In L<perlrun>, the behavior of the C<-0NNN> switch for C<-0400> or higher
d430b8e7 2222has been clarified (5.12.2).
5076a392 2223
cdc10f43
FC
2224=head3 Maintenance policy
2225
2226L<perlpolicy> now contains the policy on what patches are acceptable for
2227maintenance branches (5.12.1).
2228
41e29def 2229=head3 Deprecation policy
5076a392 2230
41e29def 2231L<perlpolicy> now contains the policy on compatibility and deprecation
d430b8e7 2232along with definitions of terms like "deprecation" (5.12.2).
5076a392 2233
41e29def 2234=head3 New descriptions in L<perldiag>
5076a392
FC
2235
2236The following existing diagnostics are now documented:
2237
2238=over 4
2239
2240=item *
2241
2242L<Ambiguous use of %c resolved as operator %c|perldiag/"Ambiguous use of %c resolved as operator %c">
2243
2244=item *
2245
2246L<Ambiguous use of %c{%s} resolved to %c%s|perldiag/"Ambiguous use of %c{%s} resolved to %c%s">
2247
2248=item *
2249
2250L<Ambiguous use of %c{%s%s} resolved to %c%s%s|perldiag/"Ambiguous use of %c{%s%s} resolved to %c%s%s">
2251
2252=item *
2253
2254L<Ambiguous use of -%s resolved as -&%s()|perldiag/"Ambiguous use of -%s resolved as -&%s()">
2255
2256=item *
2257
2258L<Invalid strict version format (%s)|perldiag/"Invalid strict version format (%s)">
2259
2260=item *
2261
2262L<Invalid version format (%s)|perldiag/"Invalid version format (%s)">
2263
2264=item *
2265
2266L<Invalid version object|perldiag/"Invalid version object">
2267
2268=back
2269
5076a392
FC
2270=head3 L<perlbook>
2271
41e29def 2272L<perlbook> has been expanded to cover many more popular books.
5076a392 2273
41e29def 2274=head3 C<SvTRUE> macro
5076a392 2275
41e29def
FC
2276The documentation for the C<SvTRUE> macro in
2277L<perlapi> was simply wrong in stating that
5076a392
FC
2278get-magic is not processed. It has been corrected.
2279
41e29def 2280=head3 L<perlvar> revamp
5076a392 2281
41e29def 2282L<perlvar> reorders the variables and groups them by topic. Each variable
5076a392 2283introduced after Perl 5.000 notes the first version in which it is
41e29def 2284available. L<perlvar> also has a new section for deprecated variables to
5076a392
FC
2285note when they were removed.
2286
41e29def 2287=head3 Array and hash slices in scalar context
5076a392 2288
41e29def 2289These are now documented in L<perldata>.
5076a392 2290
41e29def 2291=head3 C<use locale> and formats
5076a392
FC
2292
2293L<perlform> and L<perllocale> have been corrected to state that
2294C<use locale> affects formats.
2295
5076a392
FC
2296=head3 L<overload>
2297
5076a392
FC
2298L<overload>'s documentation has practically undergone a rewrite. It
2299is now much more straightforward and clear.
2300
cc13eef1 2301=head3 perlhack and perlrepository revamp
5076a392
FC
2302
2303The L<perlhack> and perlrepository documents have been heavily edited and
2304split up into several new documents.
2305
2306The L<perlhack> document is now much shorter, and focuses on the Perl 5
2307development process and submitting patches to Perl. The technical content has
2308been moved to several new documents, L<perlsource>, L<perlinterp>,
2309L<perlhacktut>, and L<perlhacktips>. This technical content has only been
2310lightly edited.
2311
2312The perlrepository document has been renamed to L<perlgit>. This new document
2313is just a how-to on using git with the Perl source code. Any other content
2314that used to be in perlrepository has been moved to perlhack.
2315
41e29def 2316=head3 Time::Piece examples
5076a392
FC
2317
2318Examples in L<perlfaq4> have been updated to show the use of
41e29def 2319L<Time::Piece>.
5076a392
FC
2320
2321=head1 Diagnostics
2322
2323The following additions or changes have been made to diagnostic output,
2324including warnings and fatal error messages. For the complete list of
2325diagnostic messages, see L<perldiag>.
2326
2327=head2 New Diagnostics
2328
a593b319
FC
2329=head3 New Errors
2330
5076a392
FC
2331=over
2332
a593b319 2333=item Closure prototype called
5076a392 2334
a593b319
FC
2335This error occurs when a subroutine reference passed to an attribute
2336handler is called, if the subroutine is a closure [perl #68560].
5076a392 2337
a593b319 2338=item Insecure user-defined property %s
5076a392 2339
a593b319
FC
2340Perl detected tainted data when trying to compile a regular
2341expression that contains a call to a user-defined character property
2342function, i.e. C<\p{IsFoo}> or C<\p{InFoo}>.
2343See L<perlunicode/User-Defined Character Properties> and L<perlsec>.
5076a392 2344
a593b319 2345=item panic: gp_free failed to free glob pointer - something is repeatedly re-creating entries
5076a392 2346
a593b319
FC
2347This new error is triggered if a destructor called on an object in a
2348typeglob that is being freed creates a new typeglob entry containing an
2349object with a destructor that creates a new entry containing an object....
5076a392 2350
a593b319 2351=item Parsing code internal error (%s)
5076a392 2352
a593b319
FC
2353This new fatal error is produced when parsing
2354code supplied by an extension violates the
2355parser's API in a detectable way.
5076a392 2356
a593b319 2357=item refcnt: fd %d%s
5076a392 2358
a593b319
FC
2359This new error only occurs if a internal consistency check fails when a
2360pipe is about to be closed.
5076a392 2361
a593b319 2362=item Regexp modifier "/%c" may not appear twice
5076a392 2363
a593b319
FC
2364The regular expression pattern has one of the
2365mutually exclusive modifiers repeated.
5076a392 2366
a593b319 2367=item Regexp modifiers "/%c" and "/%c" are mutually exclusive
5076a392 2368
a593b319
FC
2369The regular expression pattern has more than one of the mutually
2370exclusive modifiers.
5076a392 2371
a593b319 2372=item Using !~ with %s doesn't make sense
5076a392 2373
a593b319 2374This error occurs when C<!~> is used with C<s///r> or C<y///r>.
5076a392 2375
a593b319 2376=back
5076a392 2377
a593b319 2378=head3 New Warnings
5076a392 2379
a593b319 2380=over
5076a392 2381
a593b319 2382=item "\b{" is deprecated; use "\b\{" instead
5076a392 2383
a593b319 2384=item "\B{" is deprecated; use "\B\{" instead
5076a392 2385
a593b319
FC
2386Use of an unescaped "{" immediately following a C<\b> or C<\B> is now
2387deprecated so as to reserve its use for Perl itself in a future release.
5076a392 2388
a593b319 2389=item Operation "%s" returns its argument for ...
5076a392 2390
a593b319
FC
2391Performing an operation requiring Unicode semantics (such as case-folding)
2392on a Unicode surrogate or a non-Unicode character now triggers a warning:
2393'Operation "%s" returns its argument for ...'.
5076a392 2394
a593b319
FC
2395=item Use of qw(...) as parentheses is deprecated
2396
2397See L</"Use of qw(...) as parentheses">, above, for details.
5076a392
FC
2398
2399=back
2400
2401=head2 Changes to Existing Diagnostics
2402
2403=over 4
2404
2405=item *
2406
4ed2cea4
FC
2407The "Variable $foo is not imported" warning that precedes a
2408C<strict 'vars'> error has now been assigned the "misc" category, so that
2409C<no warnings> will suppress it [perl #73712].
2410
2411=item *
2412
5076a392
FC
2413C<warn> and C<die> now produce 'Wide character' warnings when fed a
2414character outside the byte range if STDERR is a byte-sized handle.
2415
2416=item *
2417
2418The 'Layer does not match this perl' error message has been replaced with
a593b319 2419these more helpful messages [perl #73754]:
5076a392
FC
2420
2421=over 4
2422
2423=item *
2424
2425PerlIO layer function table size (%d) does not match size expected by this
2426perl (%d)
2427
2428=item *
2429
2430PerlIO layer instance size (%d) does not match size expected by this perl
2431(%d)
2432
2433=back
2434
5076a392
FC
2435=item *
2436
2437The "Found = in conditional" warning that is emitted when a constant is
2438assigned to a variable in a condition is now withheld if the constant is
2439actually a subroutine or one generated by C<use constant>, since the value
2440of the constant may not be known at the time the program is written
2441[perl #77762].
2442
2443=item *
2444
2445Previously, if none of the C<gethostbyaddr>, C<gethostbyname> and
2446C<gethostent> functions were implemented on a given platform, they would
2447all die with the message 'Unsupported socket function "gethostent" called',
2448with analogous messages for C<getnet*> and C<getserv*>. This has been
2449corrected.
2450
2451=item *
2452
a593b319
FC
2453The warning message about unrecognized regular expression escapes passed
2454through has been changed to include any literal '{' following the
2455two-character escape. E.g., "\q{" is now emitted instead of "\q".
5076a392
FC
2456
2457=back
2458
2459=head1 Utility Changes
2460
0b88cc74 2461=head3 L<perlbug>
5076a392
FC
2462
2463=over 4
2464
2465=item *
2466
0b88cc74
FC
2467L<perlbug> now looks in the EMAIL environment variable for a return address
2468if the REPLY-TO and REPLYTO variables are empty.
5076a392
FC
2469
2470=item *
2471
0b88cc74
FC
2472L<perlbug> did not previously generate a From: header, potentially
2473resulting in dropped mail. Now it does include that header.
5076a392
FC
2474
2475=item *
2476
0b88cc74 2477The user's address is now used as the return-path.
4ed2cea4 2478
0b88cc74
FC
2479Many systems these days don't have a valid Internet domain name and
2480perlbug@perl.org does not accept email with a return-path that does
2481not resolve. So the user's address is now passed to sendmail so it's
2482less likely to get stuck in a mail queue somewhere [perl #82996].
5076a392 2483
2c389f6c
FC
2484=item *
2485
d430b8e7
FC
2486L<perlbug> now always gives the reporter a chance to change the email
2487address it guesses for them (5.12.2).
2488
2489=item *
2490
2491L<perlbug> should no longer warn about uninitialized values when using the C<-d>
2492and C<-v> options (5.12.2).
2c389f6c 2493
5076a392
FC
2494=back
2495
0b88cc74 2496=head3 L<perl5db.pl>
5076a392 2497
0b88cc74 2498=over
5076a392
FC
2499
2500=item *
2501
0b88cc74
FC
2502The remote terminal works after forking and spawns new sessions - one
2503for each forked process.
5076a392
FC
2504
2505=back
2506
0b88cc74 2507=head3 L<ptargrep>
5076a392
FC
2508
2509=over 4
2510
2511=item *
2512
0b88cc74
FC
2513L<ptargrep> is a new utility to apply pattern matching to the contents of
2514files in a tar archive. It comes with C<Archive::Tar>.
5076a392
FC
2515
2516=back
2517
2518=head1 Configuration and Compilation
2519
61752d82
FC
2520See also L</"Naming fixes in Policy_sh.SH may invalidate Policy.sh">,
2521above.
2522
5076a392
FC
2523=over 4
2524
2525=item *
2526
87595b22
FC
2527CCINCDIR and CCLIBDIR for the mingw64
2528cross-compiler are now correctly under
5076a392
FC
2529$(CCHOME)\mingw\include and \lib rather than immediately below $(CCHOME).
2530
5076a392
FC
2531This means the 'incpath', 'libpth', 'ldflags', 'lddlflags' and
2532'ldflags_nolargefiles' values in Config.pm and Config_heavy.pl are now
87595b22 2533set correctly.
5076a392
FC
2534
2535=item *
2536
87595b22
FC
2537'make test.valgrind' has been adjusted to account for cpan/dist/ext
2538separation.
5076a392
FC
2539
2540=item *
2541
2542On compilers that support it, C<-Wwrite-strings> is now added to cflags by
2543default.
2544
2545=item *
2546
2547The C<Encode> module can now (once again) be included in a static Perl
2548build. The special-case handling for this situation got broken in Perl
25495.11.0, and has now been repaired.
2550
1e463951
FC
2551=item *
2552
2553The previous default size of a PerlIO buffer (4096 bytes) has been increased
2554to the larger of 8192 bytes and your local BUFSIZ. Benchmarks show that doubling
2555this decade-old default increases read and write performance in the neighborhood
2556of 25% to 50% when using the default layers of perlio on top of unix. To choose
2557a non-default size, such as to get back the old value or to obtain an even
2558larger value, configure with:
2559
2560 ./Configure -Accflags=-DPERLIOBUF_DEFAULT_BUFSIZ=N
2561
2562where N is the desired size in bytes; it should probably be a multiple of
2563your page size.
2564
d430b8e7
FC
2565=item *
2566
2567An "incompatible operand types" error in ternary expressions when building
2568with C<clang> has been fixed (5.12.2).
2569
2570=item *
2571
2572Perl now skips setuid C<File::Copy> tests on partitions it detects to be mounted
2573as C<nosuid> (5.12.2).
2574
5076a392
FC
2575=back
2576
5076a392
FC
2577=head1 Platform Support
2578
5076a392
FC
2579=head2 New Platforms
2580
5076a392
FC
2581=over 4
2582
2583=item AIX
2584
cdc10f43 2585Perl now builds on AIX 4.2 (5.12.1).
5076a392
FC
2586
2587=back
2588
2589=head2 Discontinued Platforms
2590
2591=over 4
2592
5076a392
FC
2593=item Apollo DomainOS
2594
2595The last vestiges of support for this platform have been excised from the
2596Perl distribution. It was officially discontinued in version 5.12.0. It had
2597not worked for years before that.
2598
2599=item MacOS Classic
2600
2601The last vestiges of support for this platform have been excised from the
2602Perl distribution. It was officially discontinued in an earlier version.
2603
2604=back
2605
2606=head2 Platform-Specific Notes
2607
d430b8e7
FC
2608=head3 AIX
2609
2610=over
2611
2612=item *
2613
2614F<README.aix> has been updated with information about the XL C/C++ V11 compiler
2615suite (5.12.2).
2616
2617=back
2618
2619=head3 ARM
2620
2621=over
2622
2623=item *
2624
2625The C<d_u32align> configuration probe on ARM has been fixed (5.12.2).
2626
2627=back
2628
554003a2 2629=head3 Cygwin
5076a392
FC
2630
2631=over 4
2632
2633=item *
2634
554003a2 2635MakeMaker has been updated to build man pages on cygwin.
5076a392
FC
2636
2637=item *
2638
554003a2
FC
2639Improved rebase behaviour
2640
2641If a dll is updated on cygwin the old imagebase address is reused.
2642This solves most rebase errors, especially when updating on core dll's.
2643See L<http://www.tishler.net/jason/software/rebase/rebase-2.4.2.README> for more information.
5076a392
FC
2644
2645=item *
2646
554003a2 2647Support for the standard cygwin dll prefix, which is e.g. needed for FFI's
5076a392
FC
2648
2649=item *
2650
554003a2 2651Updated build hints file
5076a392
FC
2652
2653=back
2654
cdc10f43
FC
2655=head3 FreeBSD 7
2656
2657=over
2658
2659=item *
2660
2661FreeBSD 7 no longer contains F</usr/bin/objformat>. At build time,
2662Perl now skips the F<objformat> check for versions 7 and higher and
2663assumes ELF (5.12.1).
2664
2665=back
2666
2667=head3 HP-UX
2668
2669=over
2670
2671=item *
2672
2673Perl now allows -Duse64bitint without promoting to use64bitall on HP-UX
2674(5.12.1).
2675
2676=back
2677
554003a2 2678=head3 IRIX
5076a392
FC
2679
2680Conversion of strings to floating-point numbers is now more accurate on
2681IRIX systems [perl #32380].
2682
554003a2 2683=head3 Mac OS X
5076a392
FC
2684
2685Early versions of Mac OS X (Darwin) had buggy implementations of the
2686C<setregid>, C<setreuid>, C<setrgid> and C<setruid> functions, so perl
2687would pretend they did not exist.
2688
2689These functions are now recognised on Mac OS 10.5 (Leopard; Darwin 9) and
2690higher, as they have been fixed [perl #72990].
2691
554003a2 2692=head3 MirBSD
5076a392 2693
554003a2
FC
2694Previously if you built perl with a shared libperl.so on MirBSD (the
2695default config), it would work up to the installation; however, once
2696installed, it would be unable to find libperl. So path handling is now
2697treated as in the other BSD dialects.
5076a392 2698
554003a2 2699=head3 NetBSD
5076a392 2700
554003a2
FC
2701The NetBSD hints file has been changed to make the system's malloc the
2702default.
5076a392 2703
554003a2 2704=head3 Recent OpenBSDs now use perl's malloc
5076a392 2705
554003a2
FC
2706OpenBSD E<gt> 3.7 has a new malloc implementation which is mmap-based
2707and as such can release memory back to the OS; however, perl's use of
2708this malloc causes a substantial slowdown so we now default to using
2709perl's malloc instead [perl #75742].
5076a392 2710
554003a2 2711=head3 OpenVOS
5076a392 2712
554003a2 2713perl now builds again with OpenVOS (formerly known as Stratus VOS)
5a553547 2714[perl #78132] (5.12.3).
5076a392 2715
554003a2 2716=head3 Solaris
5076a392 2717
554003a2 2718DTrace is now supported on Solaris. There used to be build failures, but
5a553547 2719these have been fixed [perl #73630] (5.12.3).
5076a392 2720
554003a2 2721=head3 VMS
5076a392
FC
2722
2723=over
2724
2725=item *
2726
cdc10f43
FC
2727It's now possible to build extensions on older (pre 7.3-2) VMS systems.
2728
2729DCL symbol length was limited to 1K up until about seven years or
2730so ago, but there was no particularly deep reason to prevent those
2731older systems from configuring and building Perl (5.12.1).
2732
2733=item *
2734
2735We fixed the previously-broken C<-Uuseperlio> build on VMS.
2736
2737We were checking a variable that doesn't exist in the non-default
2738case of disabling perlio. Now we only look at it when it exists (5.12.1).
2739
2740=item *
2741
2742We fixed the -Uuseperlio command-line option in configure.com.
2743
2744Formerly it only worked if you went through all the questions
2745interactively and explicitly answered no (5.12.1).
2746
2747=item *
2748
554003a2 2749C<PerlIOUnix_open> now honours the default permissions on VMS.
5076a392 2750
554003a2
FC
2751When C<perlio> became the default and C<unixio> became the default bottom layer,
2752the most common path for creating files from Perl became C<PerlIOUnix_open>,
2753which has always explicitly used C<0666> as the permission mask.
5076a392 2754
554003a2
FC
2755To avoid this, C<0777> is now passed as the permissions to C<open()>. In the
2756VMS CRTL, C<0777> has a special meaning over and above intersecting with the
2757current umask; specifically, it allows Unix syscalls to preserve native default
5a553547
FC
2758permissions (5.12.3).
2759
2760=item *
2761
2762Spurious record boundaries are no longer
2763introduced by the PerlIO layer during output (5.12.3).
5076a392
FC
2764
2765=item *
2766
554003a2
FC
2767The shortening of symbols longer than 31 characters in the C sources is
2768now done by the compiler rather than by xsubpp (which could only do so
2769for generated symbols in XS code).
5076a392
FC
2770
2771=item *
2772
554003a2
FC
2773Record-oriented files (record format variable or variable with fixed control)
2774opened for write by the perlio layer will now be line-buffered to prevent the
2775introduction of spurious line breaks whenever the perlio buffer fills up.
5076a392 2776
d430b8e7
FC
2777=item *
2778
2779F<git_version.h> is now installed on VMS. This was an oversight in v5.12.0 which
2780caused some extensions to fail to build (5.12.2).
2781
2782=item *
2783
2784Several memory leaks in L<stat()|perlfunc/"stat FILEHANDLE"> have been fixed (5.12.2).
2785
2786=item *
2787
2788A memory leak in C<Perl_rename()> due to a double allocation has been
2789fixed (5.12.2).
2790
2791=item *
2792
2793A memory leak in C<vms_fid_to_name()> (used by C<realpath()> and
2794C<realname()>) has been fixed (5.12.2).
2795
5076a392
FC
2796=back
2797
554003a2 2798=head3 Windows
5076a392 2799
5a1f7719
FC
2800See also L</"fork() emulation will not wait for signalled children"> and
2801L</"Perl source code is read in text mode on Windows">, above.
2802
5076a392
FC
2803=over 4
2804
2805=item *
2806
554003a2 2807Fixed build process for SDK2003SP1 compilers.
5076a392 2808
554003a2 2809=item *
5076a392 2810
01b1a9e4
FC
2811Compilation with Visual Studio 2010 is now supported.
2812
2813=item *
2814
554003a2
FC
2815When using old 32-bit compilers, the define C<_USE_32BIT_TIME_T> will now
2816be set in C<$Config{ccflags}>. This improves portability when compiling
2817XS extensions using new compilers, but for a perl compiled with old 32-bit
2818compilers.
5076a392
FC
2819
2820=item *
2821
554003a2
FC
2822C<$Config{gccversion}> is now set correctly when perl is built using the
2823mingw64 compiler from L<http://mingw64.org> [perl #73754].
5076a392 2824
554003a2
FC
2825=item *
2826
d430b8e7
FC
2827When building Perl with the mingw64 x64 cross-compiler C<incpath>,
2828C<libpth>, C<ldflags>, C<lddlflags> and C<ldflags_nolargefiles> values
2829in F<Config.pm> and F<Config_heavy.pl> were not previously being set
2830correctly because, with that compiler, the include and lib directories
2831are not immediately below C<$(CCHOME)> (5.12.2).
2832
2833=item *
2834
554003a2
FC
2835The build process proceeds more smoothly with mingw and dmake when
2836F<C:\MSYS\bin> is in the PATH, due to a C<Cwd> fix.
5076a392
FC
2837
2838=item *
2839
554003a2
FC
2840Support for building with Visual C++ 2010 is now underway, but is not yet
2841complete. See F<README.win32> or L<perlwin32> for more details.
5076a392 2842
554003a2
FC
2843=item *
2844
2845The option to use an externally-supplied C<crypt()>, or to build with no
2846C<crypt()> at all, has been removed. Perl supplies its own C<crypt()>
2847implementation for Windows, and the political situation that required
2848this part of the distribution to sometimes be omitted is long gone.
5076a392
FC
2849
2850=back
2851
2852=head1 Internal Changes
2853
1e463951 2854=head2 New APIs
5076a392 2855
1e463951 2856=head3 CLONE_PARAMS structure added to ease correct thread creation
5076a392 2857
1e463951
FC
2858Modules that create threads should now create C<CLONE_PARAMS> structures
2859by calling the new function C<Perl_clone_params_new()>, and free them with
2860C<Perl_clone_params_del()>. This will ensure compatibility with any future
2861changes to the internals of the C<CLONE_PARAMS> structure layout, and that
2862it is correctly allocated and initialised.
5076a392 2863
1e463951 2864=head3 New parsing functions
5076a392 2865
1e463951
FC
2866Several functions have been added for parsing statements or multiple
2867statements:
5076a392 2868
1e463951 2869=over
5076a392
FC
2870
2871=item *
2872
1e463951 2873C<parse_fullstmt> parses a complete Perl statement.
5076a392
FC
2874
2875=item *
2876
1e463951
FC
2877C<parse_stmtseq> parses a sequence of statements, up
2878to closing brace or EOF.
5076a392
FC
2879
2880=item *
2881
1e463951 2882C<parse_block> parses a block [perl #78222].
5076a392
FC
2883
2884=item *
2885
1e463951
FC
2886C<parse_barestmt> parses a statement
2887without a label.
5076a392
FC
2888
2889=item *
2890
1e463951 2891C<parse_label> parses a statement label, separate from statements.
5076a392 2892
1e463951 2893=back
5076a392 2894
1e463951
FC
2895The
2896L<C<parse_fullexpr()>|perlapi/parse_fullexpr>,
2897L<C<parse_listexpr()>|perlapi/parse_listexpr>,
2898L<C<parse_termexpr()>|perlapi/parse_termexpr>, and
2899L<C<parse_arithexpr()>|perlapi/parse_arithexpr>
2900functions have been added to the API. They perform
2901recursive-descent parsing of expressions at various precedence levels.
2902They are expected to be used by syntax plugins.
5076a392 2903
1e463951 2904See L<perlapi> for details.
5076a392 2905
1e463951 2906=head3 Hints hash API
5076a392 2907
1e463951
FC
2908A new C API for introspecting the hinthash C<%^H> at runtime has been
2909added. See C<cop_hints_2hv>, C<cop_hints_fetchpvn>, C<cop_hints_fetchpvs>,
2910C<cop_hints_fetchsv>, and C<hv_copy_hints_hv> in L<perlapi> for details.
5076a392 2911
1e463951
FC
2912A new, experimental API has been added for accessing the internal
2913structure that Perl uses for C<%^H>. See the functions beginning with
2914C<cophh_> in L<perlapi>.
5076a392 2915
1e463951 2916=head3 C interface to C<caller()>
5076a392 2917
1e463951
FC
2918The C<caller_cx> function has been added as an XSUB-writer's equivalent of
2919C<caller()>. See L<perlapi> for details.
5076a392 2920
1e463951 2921=head3 Custom per-subroutine check hooks
5076a392 2922
1e463951
FC
2923XS code in an extension module can now annotate a subroutine (whether
2924implemented in XS or in Perl) so that nominated XS code will be called
2925at compile time (specifically as part of op checking) to change the op
2926tree of that subroutine. The compile-time check function (supplied by
2927the extension module) can implement argument processing that can't be
2928expressed as a prototype, generate customised compile-time warnings,
2929perform constant folding for a pure function, inline a subroutine
2930consisting of sufficiently simple ops, replace the whole call with a
2931custom op, and so on. This was previously all possible by hooking the
2932C<entersub> op checker, but the new mechanism makes it easy to tie the
2933hook to a specific subroutine. See L<perlapi/cv_set_call_checker>.
5076a392 2934
1e463951
FC
2935To help in writing custom check hooks, several subtasks within standard
2936C<entersub> op checking have been separated out and exposed in the API.
5076a392 2937
1e463951 2938=head3 Improved support for custom OPs
5076a392 2939
1e463951
FC
2940Custom ops can now be registered with the new C<custom_op_register> C
2941function and the C<XOP> structure. This will make it easier to add new
2942properties of custom ops in the future. Two new properties have been added
2943already, C<xop_class> and C<xop_peep>.
5076a392 2944
1e463951
FC
2945C<xop_class> is one of the OA_*OP constants, and allows L<B> and other
2946introspection mechanisms to work with custom ops
2947that aren't BASEOPs. C<xop_peep> is a pointer to
2948a function that will be called for ops of this
2949type from C<Perl_rpeep>.
5076a392 2950
1e463951
FC
2951See L<perlguts/Custom Operators> and L<perlapi/Custom Operators> for more
2952detail.
5076a392 2953
1e463951
FC
2954The old C<PL_custom_op_names>/C<PL_custom_op_descs> interface is still
2955supported but discouraged.
5076a392 2956
1e463951 2957=head3 Scope hooks
5076a392 2958
1e463951
FC
2959It is now possible for XS code to hook into Perl's lexical scope
2960mechanism at compile time, using the new C<Perl_blockhook_register>
2961function. See L<perlguts/"Compile-time scope hooks">.
5076a392 2962
1e463951 2963=head3 The recursive part of the peephole optimizer is now hookable
5076a392
FC
2964
2965In addition to C<PL_peepp>, for hooking into the toplevel peephole optimizer, a
2966C<PL_rpeepp> is now available to hook into the optimizer recursing into
2967side-chains of the optree.
2968
1e463951 2969=head3 New non-magical variants of existing functions
5076a392 2970
1e463951
FC
2971The following functions/macros have been added to the API. The C<*_nomg>
2972macros are equivalent to their non-_nomg variants, except that they ignore
2973get-magic. Those ending in C<_flags> allow one to specify whether
2974get-magic is processed.
5076a392 2975
1e463951
FC
2976 sv_2bool_flags
2977 SvTRUE_nomg
2978 sv_2nv_flags
2979 SvNV_nomg
2980 sv_cmp_flags
2981 sv_cmp_locale_flags
2982 sv_eq_flags
2983 sv_collxfrm_flags
5076a392 2984
1e463951 2985In some of these cases, the non-_flags functions have
5076a392
FC
2986been replaced with wrappers around the new functions.
2987
1e463951 2988=head3 pv/pvs/sv versions of existing functions
5076a392 2989
1e463951 2990Many functions ending with pvn now have equivalent pv/pvs/sv versions.
5076a392 2991
1e463951 2992=head3 List op-building functions
5076a392 2993
1e463951
FC
2994List op-building functions have been added to the
2995API. See L<op_append_elem|perlapi/op_append_elem>,
2996L<op_append_list|perlapi/op_append_list>, and
2997L<op_prepend_elem|perlapi/op_prepend_elem> in L<perlapi>.
5076a392 2998
1e463951 2999=head3 C<LINKLIST>
5076a392 3000
1e463951
FC
3001The L<LINKLIST|perlapi/LINKLIST> macro, part of op building that
3002constructs the execution-order op chain, has been added to the API.
5076a392 3003
1e463951 3004=head3 Localisation functions
5076a392 3005
1e463951
FC
3006The C<save_freeop>, C<save_op>, C<save_pushi32ptr> and C<save_pushptrptr>
3007functions have been added to the API.
5076a392 3008
1e463951 3009=head3 Stash names
5076a392 3010
1e463951
FC
3011A stash can now have a list of effective names in addition to its usual
3012name. The first effective name can be accessed via the C<HvENAME> macro,
3013which is now the recommended name to use in MRO linearisations (C<HvNAME>
3014being a fallback if there is no C<HvENAME>).
5076a392 3015
1e463951
FC
3016These names are added and deleted via C<hv_ename_add> and
3017C<hv_ename_delete>. These two functions are I<not> part of the API.
5076a392 3018
1e463951 3019=head3 New functions for finding and removing magic
5076a392 3020
1e463951
FC
3021The L<C<mg_findext()>|perlapi/mg_findext> and
3022L<C<sv_unmagicext()>|perlapi/sv_unmagicext>
3023functions have been added to the API.
3024They allow extension authors to find and remove magic attached to
3025scalars based on both the magic type and the magic virtual table, similar to how
3026C<sv_magicext()> attaches magic of a certain type and with a given virtual table
3027to a scalar. This eliminates the need for extensions to walk the list of
3028C<MAGIC> pointers of an C<SV> to find the magic that belongs to them.
5076a392 3029
1e463951 3030=head3 C<find_rundefsv>
5076a392 3031
1e463951
FC
3032This function returns the SV representing C<$_>, whether it's lexical
3033or dynamic.
5076a392 3034
1e463951 3035=head3 C<Perl_croak_no_modify>
5076a392 3036
1e463951
FC
3037C<Perl_croak_no_modify()> is short-hand for
3038C<Perl_croak("%s", PL_no_modify)>.
5076a392 3039
1e463951 3040=head3 C<PERL_STATIC_INLINE> define
5076a392 3041
1e463951
FC
3042The C<PERL_STATIC_INLINE> define has been added to provide the best-guess
3043incantation to use for static inline functions, if the C compiler supports
3044C99-style static inline. If it doesn't, it'll give a plain C<static>.
5076a392 3045
1e463951
FC
3046C<HAS_STATIC_INLINE> can be used to check if the compiler actually supports
3047inline functions.
5076a392 3048
1e463951 3049=head3 New C<pv_escape> option for hexadecimal escapes
5076a392 3050
1e463951
FC
3051A new option, C<PERL_PV_ESCAPE_NONASCII>, has been added to C<pv_escape> to
3052dump all characters above ASCII in hexadecimal. Before, one could get all
3053characters as hexadecimal or the Latin1 non-ASCII as octal.
5076a392 3054
1e463951 3055=head3 C<lex_start>
5076a392 3056
1e463951 3057C<lex_start> has been added to the API, but is considered experimental.
5076a392 3058
1e463951 3059=head3 C<op_scope()> and C<op_lvalue()>
5076a392 3060
1e463951
FC
3061The C<op_scope()> and C<op_lvalue()> functions have been added to the API,
3062but are considered experimental.
5076a392 3063
1e463951 3064=head2 C API Changes
5076a392 3065
1e463951 3066=head3 C<PERL_POLLUTE> has been removed
5076a392 3067
1e463951
FC
3068The option to define C<PERL_POLLUTE> to expose older 5.005 symbols for
3069backwards compatibility has been removed. It's use was always discouraged,
3070and MakeMaker contains a more specific escape hatch:
5076a392 3071
1e463951 3072 perl Makefile.PL POLLUTE=1
5076a392 3073
1e463951
FC
3074This can be used for modules that have not been upgraded to 5.6 naming
3075conventions (and really should be completely obsolete by now).
5076a392 3076
1e463951 3077=head3 Check API compatibility when loading XS modules
5076a392 3078
1e463951
FC
3079When perl's API changes in incompatible ways (which usually happens between
3080major releases), XS modules compiled for previous versions of perl will not
3081work anymore. They will need to be recompiled against the new perl.
5076a392 3082
1e463951
FC
3083In order to ensure that modules are recompiled, and to prevent users from
3084accidentally loading modules compiled for old perls into newer ones, the
3085C<XS_APIVERSION_BOOTCHECK> macro has been added. That macro, which is
3086called when loading every newly compiled extension, compares the API
3087version of the running perl with the version a module has been compiled for
3088and raises an exception if they don't match.
5076a392 3089
1e463951 3090=head3 Perl_fetch_cop_label
5076a392 3091
1e463951
FC
3092The first argument of the C API function C<Perl_fetch_cop_label> has changed
3093from C<struct refcounted he *> to C<COP *>, to insulate the user from
3094implementation details.
5076a392 3095
1e463951
FC
3096This API function was marked as "may change", and likely isn't in use outside
3097the core. (Neither an unpacked CPAN, nor Google's codesearch, finds any other
3098references to it.)
5076a392 3099
1e463951 3100=head3 GvCV() and GvGP() are no longer lvalues
5076a392 3101
1e463951
FC
3102The new GvCV_set() and GvGP_set() macros are now provided to replace
3103assignment to those two macros.
5076a392 3104
1e463951
FC
3105This allows a future commit to eliminate some backref magic between GV
3106and CVs, which will require complete control over assignment to the
3107gp_cv slot.
5076a392 3108
1e463951 3109=head3 CvGV() is no longer an lvalue
5076a392 3110
1e463951
FC
3111Under some circumstances, the C<CvGV()> field of a CV is now
3112reference-counted. To ensure consistent behaviour, direct assignment to
3113it, for example C<CvGV(cv) = gv> is now a compile-time error. A new macro,
3114C<CvGV_set(cv,gv)> has been introduced to perform this operation
3115safely. Note that modification of this field is not part of the public
3116API, regardless of this new macro (and despite its being listed in this section).
5076a392 3117
1e463951 3118=head3 CvSTASH() is no longer an lvalue
5076a392 3119
1e463951
FC
3120The C<CvSTASH()> macro can now only be used as an rvalue. C<CvSTASH_set()>
3121has been added to replace assignment to C<CvSTASH()>. This is to ensure
3122that backreferences are handled properly. These macros are not part of the
3123API.
5076a392 3124
1e463951 3125=head3 Calling conventions for C<newFOROP> and C<newWHILEOP>
5076a392 3126
1e463951
FC
3127The way the parser handles labels has been cleaned up and refactored. As a
3128result, the C<newFOROP()> constructor function no longer takes a parameter
3129stating what label is to go in the state op.
5076a392 3130
1e463951
FC
3131The C<newWHILEOP()> and C<newFOROP()> functions no longer accept a line
3132number as a parameter.
5076a392 3133
1e463951 3134=head3 Flags passed to C<uvuni_to_utf8_flags> and C<utf8n_to_uvuni>
5076a392 3135
1e463951
FC
3136Some of the flags parameters to uvuni_to_utf8_flags() and
3137utf8n_to_uvuni() have changed. This is a result of Perl's now allowing
5076a392
FC
3138internal storage and manipulation of code points that are problematic
3139in some situations. Hence, the default actions for these functions has
3140been complemented to allow these code points. The new flags are
3141documented in L<perlapi>. Code that requires the problematic code
483b16f3 3142points to be rejected needs to change to use the new flags. Some flag
5076a392
FC
3143names are retained for backward source compatibility, though they do
3144nothing, as they are now the default. However the flags
3145C<UNICODE_ALLOW_FDD0>, C<UNICODE_ALLOW_FFFF>, C<UNICODE_ILLEGAL>, and
3146C<UNICODE_IS_ILLEGAL> have been removed, as they stem from a
3147fundamentally broken model of how the Unicode non-character code points
3148should be handled, which is now described in
3149L<perlunicode/Non-character code points>. See also L</Selected Bug Fixes>.
3150
1e463951 3151XXX Which bugs in particular? Selected Bug Fixes is too long for this link
483b16f3
KW
3152to be meaningful right now
3153I don't see the bugs in that section currently -- khw
5076a392 3154
1e463951 3155=head2 Deprecated C APIs
5076a392 3156
1e463951 3157=over
5076a392 3158
1e463951 3159=item C<Perl_ptr_table_clear>
5076a392 3160
1e463951
FC
3161C<Perl_ptr_table_clear> is no longer part of Perl's public API. Calling it
3162now generates a deprecation warning, and it will be removed in a future
3163release.
5076a392 3164
1e463951 3165=item C<sv_compile_2op>
5076a392 3166
1e463951
FC
3167The C<sv_compile_2op()> API function is now deprecated. Searches suggest
3168that nothing on CPAN is using it, so this should have zero impact.
5076a392 3169
1e463951
FC
3170It attempted to provide an API to compile code down to an optree, but failed
3171to bind correctly to lexicals in the enclosing scope. It's not possible to
3172fix this problem within the constraints of its parameters and return value.
5076a392 3173
1e463951 3174=item C<find_rundefsvoffset>
5076a392 3175
1e463951
FC
3176The C<find_rundefsvoffset> function has been deprecated. It appeared that
3177its design was insufficient for reliably getting the lexical C<$_> at
3178run-time.
5076a392 3179
1e463951
FC
3180Use the new C<find_rundefsv> function or the C<UNDERBAR> macro
3181instead. They directly return the right SV representing C<$_>, whether it's
3182lexical or dynamic.
5076a392 3183
1e463951 3184=item C<CALL_FPTR> and C<CPERLscope>
5076a392 3185
1e463951
FC
3186Those are left from an old implementation of C<MULTIPLICITY> using C++ objects,
3187which was removed in Perl 5.8. Nowadays these macros do exactly nothing, so
3188they shouldn't be used anymore.
5076a392 3189
1e463951
FC
3190For compatibility, they are still defined for external C<XS> code. Only
3191extensions defining C<PERL_CORE> must be updated now.
5076a392 3192
1e463951 3193=back
5076a392 3194
1e463951 3195=head2 Other Internal Changes
5076a392 3196
1e463951 3197=head3 Stack unwinding
5076a392 3198
1e463951
FC
3199The protocol for unwinding the C stack at the last stage of a C<die>
3200has changed how it identifies the target stack frame. This now uses
3201a separate variable C<PL_restartjmpenv>, where previously it relied on
3202the C<blk_eval.cur_top_env> pointer in the C<eval> context frame that
3203has nominally just been discarded. This change means that code running
3204during various stages of Perl-level unwinding no longer needs to take
3205care to avoid destroying the ghost frame.
5076a392 3206
1e463951 3207=head3 Scope stack entries
5076a392 3208
1e463951
FC
3209The format of entries on the scope stack has been changed, resulting in a
3210reduction of memory usage of about 10%. In particular, the memory used by
3211the scope stack to record each active lexical variable has been halved.
5076a392 3212
1e463951 3213=head3 Memory allocation for pointer tables
5076a392 3214
1e463951
FC
3215Memory allocation for pointer tables has been changed. Previously
3216C<Perl_ptr_table_store> allocated memory from the same arena system as
3217C<SV> bodies and C<HE>s, with freed memory remaining bound to those arenas
3218until interpreter exit. Now it allocates memory from arenas private to the
3219specific pointer table, and that memory is returned to the system when
3220C<Perl_ptr_table_free> is called. Additionally, allocation and release are
3221both less CPU intensive.
5076a392 3222
1e463951 3223=head3 C<UNDERBAR>
5076a392 3224
1e463951
FC
3225The C<UNDERBAR> macro now calls C<find_rundefsv>. C<dUNDERBAR> is now a
3226noop but should still be used to ensure past and future compatibility.
5076a392 3227
1e463951 3228=head3 String comparison routines renamed
5076a392 3229
1e463951
FC
3230The ibcmp_* functions have been renamed and are now called foldEQ,
3231foldEQ_locale and foldEQ_utf8. The old names are still available as
3232macros.
3233
3234=head3 C<chop> and C<chomp> implementations merged
3235
3236The opcode bodies for C<chop> and C<chomp> and for C<schop> and C<schomp>
3237have been merged. The implementation functions C<Perl_do_chop()> and
3238C<Perl_do_chomp()>, never part of the public API, have been merged and
3239moved to a static function in F<pp.c>. This shrinks the perl binary
3240slightly, and should not affect any code outside the core (unless it is
3241relying on the order of side effects when C<chomp> is passed a I<list> of
3242values).
5076a392
FC
3243
3244=head1 Selected Bug Fixes
3245
e8e35311
FC
3246=head2 I/O
3247
5076a392
FC
3248=over 4
3249
3250=item *
3251
e8e35311 3252Perl no longer produces this warning:
a593b319
FC
3253
3254 $ perl -we 'open my $f, ">", \my $x; binmode $f, "scalar"'
3255 Use of uninitialized value in binmode at -e line 1.
3256
3257=item *
3258
e8e35311
FC
3259Opening a glob reference via C<< open $fh, "E<gt>", \*glob >> will no longer
3260cause the glob to be corrupted when the filehandle is printed to. This would
3261cause perl to crash whenever the glob's contents were accessed
3262[perl #77492].
4ed2cea4
FC
3263
3264=item *
3265
e8e35311
FC
3266PerlIO no longer crashes when called recursively, e.g., from a signal
3267handler. Now it just leaks memory [perl #75556].
4ed2cea4
FC
3268
3269=item *
3270
e8e35311
FC
3271Most I/O functions were not warning for unopened handles unless the
3272'closed' and 'unopened' warnings categories were both enabled. Now only
3273C<use warnings 'unopened'> is necessary to trigger these warnings (as was
438c239f 3274always meant to be the case).
4ed2cea4
FC
3275
3276=item *
3277
438c239f 3278There have been several fixes to PerlIO layers:
e8e35311 3279
438c239f
FC
3280When C<binmode FH, ":crlf"> pushes the C<:crlf> layer on top of the stack,
3281it no longer enables crlf layers lower in the stack, to avoid unexpected
3282results [perl #38456].
4ed2cea4 3283
438c239f
FC
3284Opening a file in C<:raw> mode now does what it advertises to do (first
3285open the file, then binmode it), instead of simply leaving off the top
3286layer [perl #80764].
5076a392 3287
438c239f
FC
3288The three layers C<:pop>, C<:utf8> and C<:bytes> didn't allow stacking when
3289opening a file. For example
e8e35311 3290this:
5076a392 3291
e8e35311 3292 open FH, '>:pop:perlio', 'some.file' or die $!;
5076a392 3293
438c239f
FC
3294Would throw an error: "Invalid argument". This has been fixed in this
3295release [perl #82484].
5076a392 3296
e8e35311
FC
3297=back
3298
3299=head2 Regular Expression Bug Fixes
3300
3301=over
5076a392
FC
3302
3303=item *
3304
e8e35311
FC
3305The regular expression engine no longer loops when matching
3306C<"\N{LATIN SMALL LIGATURE FF}" =~ /f+/i> and similar expressions
cdc10f43 3307[perl #72998] (5.12.1).
5076a392
FC
3308
3309=item *
3310
e8e35311
FC
3311The trie runtime code should no longer allocate massive amounts of memory,
3312fixing #74484.
5076a392
FC
3313
3314=item *
3315
438c239f
FC
3316Syntax errors in C<< (?{...}) >> blocks no longer cause panic messages
3317[perl #2353].
5076a392
FC
3318
3319=item *
3320
438c239f
FC
3321A pattern like C<(?:(o){2})?> no longer causes a "panic" error
3322[perl #39233].
5076a392
FC
3323
3324=item *
3325
438c239f 3326A fatal error in regular expressions containing C<(.*?)> when processing
d430b8e7 3327UTF-8 data has been fixed [perl #75680] (5.12.2).
5076a392
FC
3328
3329=item *
3330
e8e35311 3331An erroneous regular expression engine optimisation that caused regex verbs like
438c239f 3332C<*COMMIT> sometimes to be ignored has been removed.
5076a392
FC
3333
3334=item *
3335
e8e35311
FC
3336The regular expression bracketed character class C<[\8\9]> was effectively the
3337same as C<[89\000]>, incorrectly matching a NULL character. It also gave
3338incorrect warnings that the C<8> and C<9> were ignored. Now C<[\8\9]> is the
3339same as C<[89]> and gives legitimate warnings that C<\8> and C<\9> are
3340unrecognized escape sequences, passed-through.
5076a392
FC
3341
3342=item *
3343
e8e35311
FC
3344A regular expression match in the right-hand side of a global substitution
3345(C<s///g>) that is in the same scope will no longer cause match variables
3346to have the wrong values on subsequent iterations. This can happen when an
3347array or hash subscript is interpolated in the right-hand side, as in
3348C<s|(.)|@a{ print($1), /./ }|g> [perl #19078].
5076a392
FC
3349
3350=item *
3351
438c239f
FC
3352Several cases in which characters in the Latin-1 non-ASCII range (0x80 to
33530xFF) used not to match themselves or used to match both a character class
3354and its complement have been fixed. For instance, U+00E2 could match both
3355C<\w> and C<\W> [perl #78464] [perl #18281] [perl #60156].
5076a392
FC
3356
3357=item *
3358
e8e35311
FC
3359Matching a Unicode character against an alternation containing characters
3360that happened to match continuation bytes in the former's UTF8
3361representation (C<qq{\x{30ab}} =~ /\xab|\xa9/>) would cause erroneous
3362warnings [perl #70998].
5076a392
FC
3363
3364=item *
3365
e8e35311
FC
3366The trie optimisation was not taking empty groups into account, preventing
3367'foo' from matching C</\A(?:(?:)foo|bar|zot)\z/> [perl #78356].
5076a392
FC
3368
3369=item *
3370
e8e35311
FC
3371A pattern containing a C<+> inside a lookahead would sometimes cause an
3372incorrect match failure in a global match (e.g., C</(?=(\S+))/g>)
3373[perl #68564].
5076a392
FC
3374
3375=item *
3376
e8e35311
FC
3377A regular expression optimisation would sometimes cause a match with a
3378C<{n,m}> quantifier to fail when it should match [perl #79152].
5076a392
FC
3379
3380=item *
3381
e8e35311 3382Case insensitive matching in regular expressions compiled under C<use
438c239f
FC
3383locale> now works much more sanely when the pattern or
3384target string is encoded internally in
3385UTF8. Previously, under these conditions the localeness
e8e35311
FC
3386was completely lost. Now, code points above 255 are treated as Unicode,
3387but code points between 0 and 255 are treated using the current locale
438c239f
FC
3388rules, regardless of whether the pattern or the string is encoded in UTF8.
3389The few case-insensitive matches that cross the 255/256 boundary are not
e8e35311
FC
3390allowed. For example, 0xFF does not caselessly match the character at
33910x178, LATIN CAPITAL LETTER Y WITH DIAERESIS, because 0xFF may not be
3392LATIN SMALL LETTER Y in the current locale, and Perl has no way of
3393knowing if that character even exists in the locale, much less what code
3394point it is.
5076a392
FC
3395
3396=item *
3397
e8e35311
FC
3398The C<(?|...)> regular expression construct no longer crashes if the final
3399branch has more sets of capturing parentheses than any other branch. This
3400was fixed in Perl 5.10.1 for the case of a single branch, but that fix did
3401not take multiple branches into account [perl #84746].
5076a392
FC
3402
3403=item *
3404
e8e35311
FC
3405A bug has been fixed in the implementation of C<{...}> quantifiers in
3406regular expressions that prevented the code block in
3407C</((\w+)(?{ print $2 })){2}/> from seeing the C<$2> sometimes
3408[perl #84294].
5076a392 3409
e8e35311 3410=back
5076a392 3411
e8e35311
FC
3412=head2 Syntax/Parsing Bugs
3413
3414=over
5076a392
FC
3415
3416=item *
3417
e8e35311 3418C<when(scalar){...}> no longer crashes, but produces a syntax error
cdc10f43 3419[perl #74114] (5.12.1).
5076a392
FC
3420
3421=item *
3422
e8e35311
FC
3423A label right before a string eval (C<foo: eval $string>) no longer causes
3424the label to be associated also with the first statement inside the eval
3425[perl #74290] (5.12.1).
5076a392
FC
3426
3427=item *
3428
b2c076b5 3429The C<no 5.13.2;> form of C<no> no longer tries to turn on features or
d430b8e7 3430pragmata (i.e., strict) [perl #70075] (5.12.2).
5076a392
FC
3431
3432=item *
3433
b2c076b5
FC
3434C<BEGIN {require 5.12.0}> now behaves as documented, rather than behaving
3435identically to C<use 5.12.0;>. Previously, C<require> in a C<BEGIN> block
3436was erroneously executing the C<use feature ':5.12.0'> and
3437C<use strict;> behaviour, which only C<use> was documented to
3438provide [perl #69050].
5076a392
FC
3439
3440=item *
3441
5076a392
FC
3442A regression introduced in Perl 5.12.0, making
3443C<< my $x = 3; $x = length(undef) >> result in C<$x> set to C<3> has been
d430b8e7 3444fixed. C<$x> will now be C<undef> [perl #85508] (5.12.2).
b2c076b5
FC
3445
3446=item *
3447
3448When strict 'refs' mode is off, C<%{...}> in rvalue context returns
3449C<undef> if its argument is undefined. An optimisation introduced in perl
34505.12.0 to make C<keys %{...}> faster when used as a boolean did not take
3451this into account, causing C<keys %{+undef}> (and C<keys %$foo> when
3452C<$foo> is undefined) to be an error, which it should only be in strict
3453mode [perl #81750].
5076a392
FC
3454
3455=item *
3456
e8e35311 3457Constant-folding used to cause
5076a392 3458
e8e35311 3459 $text =~ ( 1 ? /phoo/ : /bear/)
5076a392 3460
e8e35311
FC
3461to turn into
3462
3463 $text =~ /phoo/
3464
3465at compile time. Now it correctly matches against C<$_> [perl #20444].
5076a392
FC
3466
3467=item *
3468
e8e35311
FC
3469Parsing Perl code (either with string C<eval> or by loading modules) from
3470within a C<UNITCHECK> block no longer causes the interpreter to crash
3471[perl #70614].
5076a392
FC
3472
3473=item *
3474
b2c076b5
FC
3475String evals no longer fail after 2 billion scopes have been
3476compiled [perl #83364].
3477
3478=item *
3479
e8e35311
FC
3480The parser no longer hangs when encountering certain Unicode characters,
3481such as U+387 [perl #74022].
5076a392
FC
3482
3483=item *
3484
b2c076b5
FC
3485Several contexts no longer allow a Unicode character to begin a word
3486that should never begin words, for an example an accent that must follow
3487another character previously could precede all other characters.
5076a392
FC
3488
3489=item *
3490
e8e35311
FC
3491Defining a constant with the same name as one of perl's special blocks
3492(e.g., INIT) stopped working in 5.12.0, but has now been fixed
3493[perl #78634].
5076a392
FC
3494
3495=item *
3496
e8e35311
FC
3497A reference to a literal value used as a hash key (C<$hash{\"foo"}>) used
3498to be stringified, even if the hash was tied [perl #79178].
5076a392
FC
3499
3500=item *
3501
e8e35311
FC
3502A closure containing an C<if> statement followed by a constant or variable
3503is no longer treated as a constant [perl #63540].
5076a392
FC
3504
3505=item *
3506
e8e35311
FC
3507C<state> can now be used with attributes. It used to mean the same thing as
3508C<my> if attributes were present [perl #68658].
5076a392
FC
3509
3510=item *
3511
e8e35311
FC
3512Expressions like C<< @$a > 3 >> no longer cause C<$a> to be mentioned in
3513the "Use of uninitialized value in numeric gt" warning when C<$a> is
3514undefined (since it is not part of the C<E<gt>> expression, but the operand
3515of the C<@>) [perl #72090].
5076a392
FC
3516
3517=item *
3518
e8e35311
FC
3519Accessing an element of a package array with a hard-coded number (as
3520opposed to an arbitrary expression) would crash if the array did not exist.
3521Usually the array would be autovivified during compilation, but typeglob
3522manipulation could remove it, as in these two cases which used to crash:
5076a392 3523
e8e35311
FC
3524 *d = *a; print $d[0];
3525 undef *d; print $d[0];
5076a392 3526
2c389f6c
FC
3527=item *
3528
3529The C<-C> command line option, when used on the shebang line, can now be
3530followed by other options [perl #72434].
3531
3532=item *
3533
3534The C<B> module was returning C<B::OP>s instead of C<B::LOGOP>s for C<entertry> [perl #80622].
3535This was due to a bug in the perl core, not in C<B> itself.
3536
e8e35311 3537=back
5076a392 3538
e262cb24
FC
3539=head2 Stashes, Globs and Method Lookup
3540
3541Perl 5.10.0 introduced a new internal mechanism for caching MROs (method
3542resolution orders, or lists of parent classes; aka "isa" caches) to make
3543method lookup faster (so @ISA arrays would not have to be searched
3544repeatedly). Unfortunately, this brought with it quite a few bugs. Almost
3545all of these have been fixed now, along with a few MRO-related bugs that
3546existed before 5.10.0:
3547
3548=over
3549
3550=item *
3551
3552The following used to have erratic effects on method resolution, because
3553the "isa" caches were not reset or otherwise ended up listing the wrong
3554classes. These have been fixed.
3555
3556=over
3557
3558=item Aliasing packages by assigning to globs [perl #77358]
3559