diff options
Diffstat (limited to 'chromium/third_party/cygwin/lib/perl5/5.10/pods/perl581delta.pod')
| -rw-r--r-- | chromium/third_party/cygwin/lib/perl5/5.10/pods/perl581delta.pod | 1102 |
1 files changed, 0 insertions, 1102 deletions
diff --git a/chromium/third_party/cygwin/lib/perl5/5.10/pods/perl581delta.pod b/chromium/third_party/cygwin/lib/perl5/5.10/pods/perl581delta.pod deleted file mode 100644 index ecefbf7a1c7..00000000000 --- a/chromium/third_party/cygwin/lib/perl5/5.10/pods/perl581delta.pod +++ /dev/null @@ -1,1102 +0,0 @@ -=head1 NAME - -perl581delta - what is new for perl v5.8.1 - -=head1 DESCRIPTION - -This document describes differences between the 5.8.0 release and -the 5.8.1 release. - -If you are upgrading from an earlier release such as 5.6.1, first read -the L<perl58delta>, which describes differences between 5.6.0 and -5.8.0. - -In case you are wondering about 5.6.1, it was bug-fix-wise rather -identical to the development release 5.7.1. Confused? This timeline -hopefully helps a bit: it lists the new major releases, their maintenance -releases, and the development releases. - - New Maintenance Development - - 5.6.0 2000-Mar-22 - 5.7.0 2000-Sep-02 - 5.6.1 2001-Apr-08 - 5.7.1 2001-Apr-09 - 5.7.2 2001-Jul-13 - 5.7.3 2002-Mar-05 - 5.8.0 2002-Jul-18 - 5.8.1 2003-Sep-25 - -=head1 Incompatible Changes - -=head2 Hash Randomisation - -Mainly due to security reasons, the "random ordering" of hashes -has been made even more random. Previously while the order of hash -elements from keys(), values(), and each() was essentially random, -it was still repeatable. Now, however, the order varies between -different runs of Perl. - -B<Perl has never guaranteed any ordering of the hash keys>, and the -ordering has already changed several times during the lifetime of -Perl 5. Also, the ordering of hash keys has always been, and -continues to be, affected by the insertion order. - -The added randomness may affect applications. - -One possible scenario is when output of an application has included -hash data. For example, if you have used the Data::Dumper module to -dump data into different files, and then compared the files to see -whether the data has changed, now you will have false positives since -the order in which hashes are dumped will vary. In general the cure -is to sort the keys (or the values); in particular for Data::Dumper to -use the C<Sortkeys> option. If some particular order is really -important, use tied hashes: for example the Tie::IxHash module -which by default preserves the order in which the hash elements -were added. - -More subtle problem is reliance on the order of "global destruction". -That is what happens at the end of execution: Perl destroys all data -structures, including user data. If your destructors (the DESTROY -subroutines) have assumed any particular ordering to the global -destruction, there might be problems ahead. For example, in a -destructor of one object you cannot assume that objects of any other -class are still available, unless you hold a reference to them. -If the environment variable PERL_DESTRUCT_LEVEL is set to a non-zero -value, or if Perl is exiting a spawned thread, it will also destruct -the ordinary references and the symbol tables that are no longer in use. -You can't call a class method or an ordinary function on a class that -has been collected that way. - -The hash randomisation is certain to reveal hidden assumptions about -some particular ordering of hash elements, and outright bugs: it -revealed a few bugs in the Perl core and core modules. - -To disable the hash randomisation in runtime, set the environment -variable PERL_HASH_SEED to 0 (zero) before running Perl (for more -information see L<perlrun/PERL_HASH_SEED>), or to disable the feature -completely in compile time, compile with C<-DNO_HASH_SEED> (see F<INSTALL>). - -See L<perlsec/"Algorithmic Complexity Attacks"> for the original -rationale behind this change. - -=head2 UTF-8 On Filehandles No Longer Activated By Locale - -In Perl 5.8.0 all filehandles, including the standard filehandles, -were implicitly set to be in Unicode UTF-8 if the locale settings -indicated the use of UTF-8. This feature caused too many problems, -so the feature was turned off and redesigned: see L</"Core Enhancements">. - -=head2 Single-number v-strings are no longer v-strings before "=>" - -The version strings or v-strings (see L<perldata/"Version Strings">) -feature introduced in Perl 5.6.0 has been a source of some confusion-- -especially when the user did not want to use it, but Perl thought it -knew better. Especially troublesome has been the feature that before -a "=>" a version string (a "v" followed by digits) has been interpreted -as a v-string instead of a string literal. In other words: - - %h = ( v65 => 42 ); - -has meant since Perl 5.6.0 - - %h = ( 'A' => 42 ); - -(at least in platforms of ASCII progeny) Perl 5.8.1 restores the -more natural interpretation - - %h = ( 'v65' => 42 ); - -The multi-number v-strings like v65.66 and 65.66.67 still continue to -be v-strings in Perl 5.8. - -=head2 (Win32) The -C Switch Has Been Repurposed - -The -C switch has changed in an incompatible way. The old semantics -of this switch only made sense in Win32 and only in the "use utf8" -universe in 5.6.x releases, and do not make sense for the Unicode -implementation in 5.8.0. Since this switch could not have been used -by anyone, it has been repurposed. The behavior that this switch -enabled in 5.6.x releases may be supported in a transparent, -data-dependent fashion in a future release. - -For the new life of this switch, see L<"UTF-8 no longer default under -UTF-8 locales">, and L<perlrun/-C>. - -=head2 (Win32) The /d Switch Of cmd.exe - -Perl 5.8.1 uses the /d switch when running the cmd.exe shell -internally for system(), backticks, and when opening pipes to external -programs. The extra switch disables the execution of AutoRun commands -from the registry, which is generally considered undesirable when -running external programs. If you wish to retain compatibility with -the older behavior, set PERL5SHELL in your environment to C<cmd /x/c>. - -=head1 Core Enhancements - -=head2 UTF-8 no longer default under UTF-8 locales - -In Perl 5.8.0 many Unicode features were introduced. One of them -was found to be of more nuisance than benefit: the automagic -(and silent) "UTF-8-ification" of filehandles, including the -standard filehandles, if the user's locale settings indicated -use of UTF-8. - -For example, if you had C<en_US.UTF-8> as your locale, your STDIN and -STDOUT were automatically "UTF-8", in other words an implicit -binmode(..., ":utf8") was made. This meant that trying to print, say, -chr(0xff), ended up printing the bytes 0xc3 0xbf. Hardly what -you had in mind unless you were aware of this feature of Perl 5.8.0. -The problem is that the vast majority of people weren't: for example -in RedHat releases 8 and 9 the B<default> locale setting is UTF-8, so -all RedHat users got UTF-8 filehandles, whether they wanted it or not. -The pain was intensified by the Unicode implementation of Perl 5.8.0 -(still) having nasty bugs, especially related to the use of s/// and -tr///. (Bugs that have been fixed in 5.8.1) - -Therefore a decision was made to backtrack the feature and change it -from implicit silent default to explicit conscious option. The new -Perl command line option C<-C> and its counterpart environment -variable PERL_UNICODE can now be used to control how Perl and Unicode -interact at interfaces like I/O and for example the command line -arguments. See L<perlrun/-C> and L<perlrun/PERL_UNICODE> for more -information. - -=head2 Unsafe signals again available - -In Perl 5.8.0 the so-called "safe signals" were introduced. This -means that Perl no longer handles signals immediately but instead -"between opcodes", when it is safe to do so. The earlier immediate -handling easily could corrupt the internal state of Perl, resulting -in mysterious crashes. - -However, the new safer model has its problems too. Because now an -opcode, a basic unit of Perl execution, is never interrupted but -instead let to run to completion, certain operations that can take a -long time now really do take a long time. For example, certain -network operations have their own blocking and timeout mechanisms, and -being able to interrupt them immediately would be nice. - -Therefore perl 5.8.1 introduces a "backdoor" to restore the pre-5.8.0 -(pre-5.7.3, really) signal behaviour. Just set the environment variable -PERL_SIGNALS to C<unsafe>, and the old immediate (and unsafe) -signal handling behaviour returns. See L<perlrun/PERL_SIGNALS> -and L<perlipc/"Deferred Signals (Safe Signals)">. - -In completely unrelated news, you can now use safe signals with -POSIX::SigAction. See L<POSIX/POSIX::SigAction>. - -=head2 Tied Arrays with Negative Array Indices - -Formerly, the indices passed to C<FETCH>, C<STORE>, C<EXISTS>, and -C<DELETE> methods in tied array class were always non-negative. If -the actual argument was negative, Perl would call FETCHSIZE implicitly -and add the result to the index before passing the result to the tied -array method. This behaviour is now optional. If the tied array class -contains a package variable named C<$NEGATIVE_INDICES> which is set to -a true value, negative values will be passed to C<FETCH>, C<STORE>, -C<EXISTS>, and C<DELETE> unchanged. - -=head2 local ${$x} - -The syntaxes - - local ${$x} - local @{$x} - local %{$x} - -now do localise variables, given that the $x is a valid variable name. - -=head2 Unicode Character Database 4.0.0 - -The copy of the Unicode Character Database included in Perl 5.8 has -been updated to 4.0.0 from 3.2.0. This means for example that the -Unicode character properties are as in Unicode 4.0.0. - -=head2 Deprecation Warnings - -There is one new feature deprecation. Perl 5.8.0 forgot to add -some deprecation warnings, these warnings have now been added. -Finally, a reminder of an impending feature removal. - -=head3 (Reminder) Pseudo-hashes are deprecated (really) - -Pseudo-hashes were deprecated in Perl 5.8.0 and will be removed in -Perl 5.10.0, see L<perl58delta> for details. Each attempt to access -pseudo-hashes will trigger the warning C<Pseudo-hashes are deprecated>. -If you really want to continue using pseudo-hashes but not to see the -deprecation warnings, use: - - no warnings 'deprecated'; - -Or you can continue to use the L<fields> pragma, but please don't -expect the data structures to be pseudohashes any more. - -=head3 (Reminder) 5.005-style threads are deprecated (really) - -5.005-style threads (activated by C<use Thread;>) were deprecated in -Perl 5.8.0 and will be removed after Perl 5.8, see L<perl58delta> for -details. Each 5.005-style thread creation will trigger the warning -C<5.005 threads are deprecated>. If you really want to continue -using the 5.005 threads but not to see the deprecation warnings, use: - - no warnings 'deprecated'; - -=head3 (Reminder) The $* variable is deprecated (really) - -The C<$*> variable controlling multi-line matching has been deprecated -and will be removed after 5.8. The variable has been deprecated for a -long time, and a deprecation warning C<Use of $* is deprecated> is given, -now the variable will just finally be removed. The functionality has -been supplanted by the C</s> and C</m> modifiers on pattern matching. -If you really want to continue using the C<$*>-variable but not to see -the deprecation warnings, use: - - no warnings 'deprecated'; - -=head2 Miscellaneous Enhancements - -C<map> in void context is no longer expensive. C<map> is now context -aware, and will not construct a list if called in void context. - -If a socket gets closed by the server while printing to it, the client -now gets a SIGPIPE. While this new feature was not planned, it fell -naturally out of PerlIO changes, and is to be considered an accidental -feature. - -PerlIO::get_layers(FH) returns the names of the PerlIO layers -active on a filehandle. - -PerlIO::via layers can now have an optional UTF8 method to -indicate whether the layer wants to "auto-:utf8" the stream. - -utf8::is_utf8() has been added as a quick way to test whether -a scalar is encoded internally in UTF-8 (Unicode). - -=head1 Modules and Pragmata - -=head2 Updated Modules And Pragmata - -The following modules and pragmata have been updated since Perl 5.8.0: - -=over 4 - -=item base - -=item B::Bytecode - -In much better shape than it used to be. Still far from perfect, but -maybe worth a try. - -=item B::Concise - -=item B::Deparse - -=item Benchmark - -An optional feature, C<:hireswallclock>, now allows for high -resolution wall clock times (uses Time::HiRes). - -=item ByteLoader - -See B::Bytecode. - -=item bytes - -Now has bytes::substr. - -=item CGI - -=item charnames - -One can now have custom character name aliases. - -=item CPAN - -There is now a simple command line frontend to the CPAN.pm -module called F<cpan>. - -=item Data::Dumper - -A new option, Pair, allows choosing the separator between hash keys -and values. - -=item DB_File - -=item Devel::PPPort - -=item Digest::MD5 - -=item Encode - -Significant updates on the encoding pragma functionality -(tr/// and the DATA filehandle, formats). - -If a filehandle has been marked as to have an encoding, unmappable -characters are detected already during input, not later (when the -corrupted data is being used). - -The ISO 8859-6 conversion table has been corrected (the 0x30..0x39 -erroneously mapped to U+0660..U+0669, instead of U+0030..U+0039). The -GSM 03.38 conversion did not handle escape sequences correctly. The -UTF-7 encoding has been added (making Encode feature-complete with -Unicode::String). - -=item fields - -=item libnet - -=item Math::BigInt - -A lot of bugs have been fixed since v1.60, the version included in Perl -v5.8.0. Especially noteworthy are the bug in Calc that caused div and mod to -fail for some large values, and the fixes to the handling of bad inputs. - -Some new features were added, e.g. the broot() method, you can now pass -parameters to config() to change some settings at runtime, and it is now -possible to trap the creation of NaN and infinity. - -As usual, some optimizations took place and made the math overall a tad -faster. In some cases, quite a lot faster, actually. Especially alternative -libraries like Math::BigInt::GMP benefit from this. In addition, a lot of the -quite clunky routines like fsqrt() and flog() are now much much faster. - -=item MIME::Base64 - -=item NEXT - -Diamond inheritance now works. - -=item Net::Ping - -=item PerlIO::scalar - -Reading from non-string scalars (like the special variables, see -L<perlvar>) now works. - -=item podlators - -=item Pod::LaTeX - -=item PodParsers - -=item Pod::Perldoc - -Complete rewrite. As a side-effect, no longer refuses to startup when -run by root. - -=item Scalar::Util - -New utilities: refaddr, isvstring, looks_like_number, set_prototype. - -=item Storable - -Can now store code references (via B::Deparse, so not foolproof). - -=item strict - -Earlier versions of the strict pragma did not check the parameters -implicitly passed to its "import" (use) and "unimport" (no) routine. -This caused the false idiom such as: - - use strict qw(@ISA); - @ISA = qw(Foo); - -This however (probably) raised the false expectation that the strict -refs, vars and subs were being enforced (and that @ISA was somehow -"declared"). But the strict refs, vars, and subs are B<not> enforced -when using this false idiom. - -Starting from Perl 5.8.1, the above B<will> cause an error to be -raised. This may cause programs which used to execute seemingly -correctly without warnings and errors to fail when run under 5.8.1. -This happens because - - use strict qw(@ISA); - -will now fail with the error: - - Unknown 'strict' tag(s) '@ISA' - -The remedy to this problem is to replace this code with the correct idiom: - - use strict; - use vars qw(@ISA); - @ISA = qw(Foo); - -=item Term::ANSIcolor - -=item Test::Harness - -Now much more picky about extra or missing output from test scripts. - -=item Test::More - -=item Test::Simple - -=item Text::Balanced - -=item Time::HiRes - -Use of nanosleep(), if available, allows mixing subsecond sleeps with -alarms. - -=item threads - -Several fixes, for example for join() problems and memory -leaks. In some platforms (like Linux) that use glibc the minimum memory -footprint of one ithread has been reduced by several hundred kilobytes. - -=item threads::shared - -Many memory leaks have been fixed. - -=item Unicode::Collate - -=item Unicode::Normalize - -=item Win32::GetFolderPath - -=item Win32::GetOSVersion - -Now returns extra information. - -=back - -=head1 Utility Changes - -The C<h2xs> utility now produces a more modern layout: -F<Foo-Bar/lib/Foo/Bar.pm> instead of F<Foo/Bar/Bar.pm>. -Also, the boilerplate test is now called F<t/Foo-Bar.t> -instead of F<t/1.t>. - -The Perl debugger (F<lib/perl5db.pl>) has now been extensively -documented and bugs found while documenting have been fixed. - -C<perldoc> has been rewritten from scratch to be more robust and -feature rich. - -C<perlcc -B> works now at least somewhat better, while C<perlcc -c> -is rather more broken. (The Perl compiler suite as a whole continues -to be experimental.) - -=head1 New Documentation - -perl573delta has been added to list the differences between the -(now quite obsolete) development releases 5.7.2 and 5.7.3. - -perl58delta has been added: it is the perldelta of 5.8.0, detailing -the differences between 5.6.0 and 5.8.0. - -perlartistic has been added: it is the Artistic License in pod format, -making it easier for modules to refer to it. - -perlcheat has been added: it is a Perl cheat sheet. - -perlgpl has been added: it is the GNU General Public License in pod -format, making it easier for modules to refer to it. - -perlmacosx has been added to tell about the installation and use -of Perl in Mac OS X. - -perlos400 has been added to tell about the installation and use -of Perl in OS/400 PASE. - -perlreref has been added: it is a regular expressions quick reference. - -=head1 Installation and Configuration Improvements - -The UNIX standard Perl location, F</usr/bin/perl>, is no longer -overwritten by default if it exists. This change was very prudent -because so many UNIX vendors already provide a F</usr/bin/perl>, -but simultaneously many system utilities may depend on that -exact version of Perl, so better not to overwrite it. - -One can now specify installation directories for site and vendor man -and HTML pages, and site and vendor scripts. See F<INSTALL>. - -One can now specify a destination directory for Perl installation -by specifying the DESTDIR variable for C<make install>. (This feature -is slightly different from the previous C<Configure -Dinstallprefix=...>.) -See F<INSTALL>. - -gcc versions 3.x introduced a new warning that caused a lot of noise -during Perl compilation: C<gcc -Ialreadyknowndirectory (warning: -changing search order)>. This warning has now been avoided by -Configure weeding out such directories before the compilation. - -One can now build subsets of Perl core modules by using the -Configure flags C<-Dnoextensions=...> and C<-Donlyextensions=...>, -see F<INSTALL>. - -=head2 Platform-specific enhancements - -In Cygwin Perl can now be built with threads (C<Configure -Duseithreads>). -This works with both Cygwin 1.3.22 and Cygwin 1.5.3. - -In newer FreeBSD releases Perl 5.8.0 compilation failed because of -trying to use F<malloc.h>, which in FreeBSD is just a dummy file, and -a fatal error to even try to use. Now F<malloc.h> is not used. - -Perl is now known to build also in Hitachi HI-UXMPP. - -Perl is now known to build again in LynxOS. - -Mac OS X now installs with Perl version number embedded in -installation directory names for easier upgrading of user-compiled -Perl, and the installation directories in general are more standard. -In other words, the default installation no longer breaks the -Apple-provided Perl. On the other hand, with C<Configure -Dprefix=/usr> -you can now really replace the Apple-supplied Perl (B<please be careful>). - -Mac OS X now builds Perl statically by default. This change was done -mainly for faster startup times. The Apple-provided Perl is still -dynamically linked and shared, and you can enable the sharedness for -your own Perl builds by C<Configure -Duseshrplib>. - -Perl has been ported to IBM's OS/400 PASE environment. The best way -to build a Perl for PASE is to use an AIX host as a cross-compilation -environment. See README.os400. - -Yet another cross-compilation option has been added: now Perl builds -on OpenZaurus, an Linux distribution based on Mandrake + Embedix for -the Sharp Zaurus PDA. See the Cross/README file. - -Tru64 when using gcc 3 drops the optimisation for F<toke.c> to C<-O2> -because of gigantic memory use with the default C<-O3>. - -Tru64 can now build Perl with the newer Berkeley DBs. - -Building Perl on WinCE has been much enhanced, see F<README.ce> -and F<README.perlce>. - -=head1 Selected Bug Fixes - -=head2 Closures, eval and lexicals - -There have been many fixes in the area of anonymous subs, lexicals and -closures. Although this means that Perl is now more "correct", it is -possible that some existing code will break that happens to rely on -the faulty behaviour. In practice this is unlikely unless your code -contains a very complex nesting of anonymous subs, evals and lexicals. - -=head2 Generic fixes - -If an input filehandle is marked C<:utf8> and Perl sees illegal UTF-8 -coming in when doing C<< <FH> >>, if warnings are enabled a warning is -immediately given - instead of being silent about it and Perl being -unhappy about the broken data later. (The C<:encoding(utf8)> layer -also works the same way.) - -binmode(SOCKET, ":utf8") only worked on the input side, not on the -output side of the socket. Now it works both ways. - -For threaded Perls certain system database functions like getpwent() -and getgrent() now grow their result buffer dynamically, instead of -failing. This means that at sites with lots of users and groups the -functions no longer fail by returning only partial results. - -Perl 5.8.0 had accidentally broken the capability for users -to define their own uppercase<->lowercase Unicode mappings -(as advertised by the Camel). This feature has been fixed and -is also documented better. - -In 5.8.0 this - - $some_unicode .= <FH>; - -didn't work correctly but instead corrupted the data. This has now -been fixed. - -Tied methods like FETCH etc. may now safely access tied values, i.e. -resulting in a recursive call to FETCH etc. Remember to break the -recursion, though. - -At startup Perl blocks the SIGFPE signal away since there isn't much -Perl can do about it. Previously this blocking was in effect also for -programs executed from within Perl. Now Perl restores the original -SIGFPE handling routine, whatever it was, before running external -programs. - -Linenumbers in Perl scripts may now be greater than 65536, or 2**16. -(Perl scripts have always been able to be larger than that, it's just -that the linenumber for reported errors and warnings have "wrapped -around".) While scripts that large usually indicate a need to rethink -your code a bit, such Perl scripts do exist, for example as results -from generated code. Now linenumbers can go all the way to -4294967296, or 2**32. - -=head2 Platform-specific fixes - -Linux - -=over 4 - -=item * - -Setting $0 works again (with certain limitations that -Perl cannot do much about: see L<perlvar/$0>) - -=back - -HP-UX - -=over 4 - -=item * - -Setting $0 now works. - -=back - -VMS - -=over 4 - -=item * - -Configuration now tests for the presence of C<poll()>, and IO::Poll -now uses the vendor-supplied function if detected. - -=item * - -A rare access violation at Perl start-up could occur if the Perl image was -installed with privileges or if there was an identifier with the -subsystem attribute set in the process's rightslist. Either of these -circumstances triggered tainting code that contained a pointer bug. -The faulty pointer arithmetic has been fixed. - -=item * - -The length limit on values (not keys) in the %ENV hash has been raised -from 255 bytes to 32640 bytes (except when the PERL_ENV_TABLES setting -overrides the default use of logical names for %ENV). If it is -necessary to access these long values from outside Perl, be aware that -they are implemented using search list logical names that store the -value in pieces, each 255-byte piece (up to 128 of them) being an -element in the search list. When doing a lookup in %ENV from within -Perl, the elements are combined into a single value. The existing -VMS-specific ability to access individual elements of a search list -logical name via the $ENV{'foo;N'} syntax (where N is the search list -index) is unimpaired. - -=item * - -The piping implementation now uses local rather than global DCL -symbols for inter-process communication. - -=item * - -File::Find could become confused when navigating to a relative -directory whose name collided with a logical name. This problem has -been corrected by adding directory syntax to relative path names, thus -preventing logical name translation. - -=back - -Win32 - -=over 4 - -=item * - -A memory leak in the fork() emulation has been fixed. - -=item * - -The return value of the ioctl() built-in function was accidentally -broken in 5.8.0. This has been corrected. - -=item * - -The internal message loop executed by perl during blocking operations -sometimes interfered with messages that were external to Perl. -This often resulted in blocking operations terminating prematurely or -returning incorrect results, when Perl was executing under environments -that could generate Windows messages. This has been corrected. - -=item * - -Pipes and sockets are now automatically in binary mode. - -=item * - -The four-argument form of select() did not preserve $! (errno) properly -when there were errors in the underlying call. This is now fixed. - -=item * - -The "CR CR LF" problem of has been fixed, binmode(FH, ":crlf") -is now effectively a no-op. - -=back - -=head1 New or Changed Diagnostics - -All the warnings related to pack() and unpack() were made more -informative and consistent. - -=head2 Changed "A thread exited while %d threads were running" - -The old version - - A thread exited while %d other threads were still running - -was misleading because the "other" included also the thread giving -the warning. - -=head2 Removed "Attempt to clear a restricted hash" - -It is not illegal to clear a restricted hash, so the warning -was removed. - -=head2 New "Illegal declaration of anonymous subroutine" - -You must specify the block of code for C<sub>. - -=head2 Changed "Invalid range "%s" in transliteration operator" - -The old version - - Invalid [] range "%s" in transliteration operator - -was simply wrong because there are no "[] ranges" in tr///. - -=head2 New "Missing control char name in \c" - -Self-explanatory. - -=head2 New "Newline in left-justified string for %s" - -The padding spaces would appear after the newline, which is -probably not what you had in mind. - -=head2 New "Possible precedence problem on bitwise %c operator" - -If you think this - - $x & $y == 0 - -tests whether the bitwise AND of $x and $y is zero, -you will like this warning. - -=head2 New "Pseudo-hashes are deprecated" - -This warning should have been already in 5.8.0, since they are. - -=head2 New "read() on %s filehandle %s" - -You cannot read() (or sysread()) from a closed or unopened filehandle. - -=head2 New "5.005 threads are deprecated" - -This warning should have been already in 5.8.0, since they are. - -=head2 New "Tied variable freed while still in use" - -Something pulled the plug on a live tied variable, Perl plays -safe by bailing out. - -=head2 New "To%s: illegal mapping '%s'" - -An illegal user-defined Unicode casemapping was specified. - -=head2 New "Use of freed value in iteration" - -Something modified the values being iterated over. This is not good. - -=head1 Changed Internals - -These news matter to you only if you either write XS code or like to -know about or hack Perl internals (using Devel::Peek or any of the -C<B::> modules counts), or like to run Perl with the C<-D> option. - -The embedding examples of L<perlembed> have been reviewed to be -up to date and consistent: for example, the correct use of -PERL_SYS_INIT3() and PERL_SYS_TERM(). - -Extensive reworking of the pad code (the code responsible -for lexical variables) has been conducted by Dave Mitchell. - -Extensive work on the v-strings by John Peacock. - -UTF-8 length and position cache: to speed up the handling of Unicode -(UTF-8) scalars, a cache was introduced. Potential problems exist if -an extension bypasses the official APIs and directly modifies the PV -of an SV: the UTF-8 cache does not get cleared as it should. - -APIs obsoleted in Perl 5.8.0, like sv_2pv, sv_catpvn, sv_catsv, -sv_setsv, are again available. - -Certain Perl core C APIs like cxinc and regatom are no longer -available at all to code outside the Perl core of the Perl core -extensions. This is intentional. They never should have been -available with the shorter names, and if you application depends on -them, you should (be ashamed and) contact perl5-porters to discuss -what are the proper APIs. - -Certain Perl core C APIs like C<Perl_list> are no longer available -without their C<Perl_> prefix. If your XS module stops working -because some functions cannot be found, in many cases a simple fix is -to add the C<Perl_> prefix to the function and the thread context -C<aTHX_> as the first argument of the function call. This is also how -it should always have been done: letting the Perl_-less forms to leak -from the core was an accident. For cleaner embedding you can also -force this for all APIs by defining at compile time the cpp define -PERL_NO_SHORT_NAMES. - -Perl_save_bool() has been added. - -Regexp objects (those created with C<qr>) now have S-magic rather than -R-magic. This fixed regexps of the form /...(??{...;$x})/ to no -longer ignore changes made to $x. The S-magic avoids dropping -the caching optimization and making (??{...}) constructs obscenely -slow (and consequently useless). See also L<perlguts/"Magic Variables">. -Regexp::Copy was affected by this change. - -The Perl internal debugging macros DEBUG() and DEB() have been renamed -to PERL_DEBUG() and PERL_DEB() to avoid namespace conflicts. - -C<-DL> removed (the leaktest had been broken and unsupported for years, -use alternative debugging mallocs or tools like valgrind and Purify). - -Verbose modifier C<v> added for C<-DXv> and C<-Dsv>, see L<perlrun>. - -=head1 New Tests - -In Perl 5.8.0 there were about 69000 separate tests in about 700 test files, -in Perl 5.8.1 there are about 77000 separate tests in about 780 test files. -The exact numbers depend on the Perl configuration and on the operating -system platform. - -=head1 Known Problems - -The hash randomisation mentioned in L</Incompatible Changes> is definitely -problematic: it will wake dormant bugs and shake out bad assumptions. - -If you want to use mod_perl 2.x with Perl 5.8.1, you will need -mod_perl-1.99_10 or higher. Earlier versions of mod_perl 2.x -do not work with the randomised hashes. (mod_perl 1.x works fine.) -You will also need Apache::Test 1.04 or higher. - -Many of the rarer platforms that worked 100% or pretty close to it -with perl 5.8.0 have been left a little bit untended since their -maintainers have been otherwise busy lately, and therefore there will -be more failures on those platforms. Such platforms include Mac OS -Classic, IBM z/OS (and other EBCDIC platforms), and NetWare. The most -common Perl platforms (Unix and Unix-like, Microsoft platforms, and -VMS) have large enough testing and expert population that they are -doing well. - -=head2 Tied hashes in scalar context - -Tied hashes do not currently return anything useful in scalar context, -for example when used as boolean tests: - - if (%tied_hash) { ... } - -The current nonsensical behaviour is always to return false, -regardless of whether the hash is empty or has elements. - -The root cause is that there is no interface for the implementors of -tied hashes to implement the behaviour of a hash in scalar context. - -=head2 Net::Ping 450_service and 510_ping_udp failures - -The subtests 9 and 18 of lib/Net/Ping/t/450_service.t, and the -subtest 2 of lib/Net/Ping/t/510_ping_udp.t might fail if you have -an unusual networking setup. For example in the latter case the -test is trying to send a UDP ping to the IP address 127.0.0.1. - -=head2 B::C - -The C-generating compiler backend B::C (the frontend being -C<perlcc -c>) is even more broken than it used to be because of -the extensive lexical variable changes. (The good news is that -B::Bytecode and ByteLoader are better than they used to be.) - -=head1 Platform Specific Problems - -=head2 EBCDIC Platforms - -IBM z/OS and other EBCDIC platforms continue to be problematic -regarding Unicode support. Many Unicode tests are skipped when -they really should be fixed. - -=head2 Cygwin 1.5 problems - -In Cygwin 1.5 the F<io/tell> and F<op/sysio> tests have failures for -some yet unknown reason. In 1.5.5 the threads tests stress_cv, -stress_re, and stress_string are failing unless the environment -variable PERLIO is set to "perlio" (which makes also the io/tell -failure go away). - -Perl 5.8.1 does build and work well with Cygwin 1.3: with (uname -a) -C<CYGWIN_NT-5.0 ... 1.3.22(0.78/3/2) 2003-03-18 09:20 i686 ...> -a 100% "make test" was achieved with C<Configure -des -Duseithreads>. - -=head2 HP-UX: HP cc warnings about sendfile and sendpath - -With certain HP C compiler releases (e.g. B.11.11.02) you will -get many warnings like this (lines wrapped for easier reading): - - cc: "/usr/include/sys/socket.h", line 504: warning 562: - Redeclaration of "sendfile" with a different storage class specifier: - "sendfile" will have internal linkage. - cc: "/usr/include/sys/socket.h", line 505: warning 562: - Redeclaration of "sendpath" with a different storage class specifier: - "sendpath" will have internal linkage. - -The warnings show up both during the build of Perl and during certain -lib/ExtUtils tests that invoke the C compiler. The warning, however, -is not serious and can be ignored. - -=head2 IRIX: t/uni/tr_7jis.t falsely failing - -The test t/uni/tr_7jis.t is known to report failure under 'make test' -or the test harness with certain releases of IRIX (at least IRIX 6.5 -and MIPSpro Compilers Version 7.3.1.1m), but if run manually the test -fully passes. - -=head2 Mac OS X: no usemymalloc - -The Perl malloc (C<-Dusemymalloc>) does not work at all in Mac OS X. -This is not that serious, though, since the native malloc works just -fine. - -=head2 Tru64: No threaded builds with GNU cc (gcc) - -In the latest Tru64 releases (e.g. v5.1B or later) gcc cannot be used -to compile a threaded Perl (-Duseithreads) because the system -C<< <pthread.h> >> file doesn't know about gcc. - -=head2 Win32: sysopen, sysread, syswrite - -As of the 5.8.0 release, sysopen()/sysread()/syswrite() do not behave -like they used to in 5.6.1 and earlier with respect to "text" mode. -These built-ins now always operate in "binary" mode (even if sysopen() -was passed the O_TEXT flag, or if binmode() was used on the file -handle). Note that this issue should only make a difference for disk -files, as sockets and pipes have always been in "binary" mode in the -Windows port. As this behavior is currently considered a bug, -compatible behavior may be re-introduced in a future release. Until -then, the use of sysopen(), sysread() and syswrite() is not supported -for "text" mode operations. - -=head1 Future Directions - -The following things B<might> happen in future. The first publicly -available releases having these characteristics will be the developer -releases Perl 5.9.x, culminating in the Perl 5.10.0 release. These -are our best guesses at the moment: we reserve the right to rethink. - -=over 4 - -=item * - -PerlIO will become The Default. Currently (in Perl 5.8.x) the stdio -library is still used if Perl thinks it can use certain tricks to -make stdio go B<really> fast. For future releases our goal is to -make PerlIO go even faster. - -=item * - -A new feature called I<assertions> will be available. This means that -one can have code called assertions sprinkled in the code: usually -they are optimised away, but they can be enabled with the C<-A> option. - -=item * - -A new operator C<//> (defined-or) will be available. This means that -one will be able to say - - $a // $b - -instead of - - defined $a ? $a : $b - -and - - $c //= $d; - -instead of - - $c = $d unless defined $c; - -The operator will have the same precedence and associativity as C<||>. -A source code patch against the Perl 5.8.1 sources will be available -in CPAN as F<authors/id/H/HM/HMBRAND/dor-5.8.1.diff>. - -=item * - -C<unpack()> will default to unpacking the C<$_>. - -=item * - -Various Copy-On-Write techniques will be investigated in hopes -of speeding up Perl. - -=item * - -CPANPLUS, Inline, and Module::Build will become core modules. - -=item * - -The ability to write true lexically scoped pragmas will be introduced. - -=item * - -Work will continue on the bytecompiler and byteloader. - -=item * - -v-strings as they currently exist are scheduled to be deprecated. The -v-less form (1.2.3) will become a "version object" when used with C<use>, -C<require>, and C<$VERSION>. $^V will also be a "version object" so the -printf("%vd",...) construct will no longer be needed. The v-ful version -(v1.2.3) will become obsolete. The equivalence of strings and v-strings (e.g. -that currently 5.8.0 is equal to "\5\8\0") will go away. B<There may be no -deprecation warning for v-strings>, though: it is quite hard to detect when -v-strings are being used safely, and when they are not. - -=item * - -5.005 Threads Will Be Removed - -=item * - -The C<$*> Variable Will Be Removed -(it was deprecated a long time ago) - -=item * - -Pseudohashes Will Be Removed - -=back - -=head1 Reporting Bugs - -If you find what you think is a bug, you might check the articles -recently posted to the comp.lang.perl.misc newsgroup and the perl -bug database at http://bugs.perl.org/ . There may also be -information at http://www.perl.com/ , the Perl Home Page. - -If you believe you have an unreported bug, please run the B<perlbug> -program included with your release. Be sure to trim your bug down -to a tiny but sufficient test case. Your bug report, along with the -output of C<perl -V>, will be sent off to perlbug@perl.org to be -analysed by the Perl porting team. You can browse and search -the Perl 5 bugs at http://bugs.perl.org/ - -=head1 SEE ALSO - -The F<Changes> file for exhaustive details on what changed. - -The F<INSTALL> file for how to build Perl. - -The F<README> file for general stuff. - -The F<Artistic> and F<Copying> files for copyright information. - -=cut |