with external libraries or existing data. G_FLOAT is still available as
a configuration option. The default on VAX (D_FLOAT) has not changed.
+=head2 New Unicode Semantics (no more C<use utf8>, almost)
+
+Previously in Perl 5.6 to use Unicode one would say "use utf8" and
+then the operations (like string concatenation) were Unicode-aware
+in that lexical scope.
+
+This was found to be an inconvenient interface, and in Perl 5.8 the
+Unicode model has completely changed: now the "Unicodeness" is bound
+to the data itself, and for most of the time "use utf8" is not needed
+at all. The only remaining use of "use utf8" is when the Perl script
+itself has been written in the UTF-8 encoding of Unicode. (UTF-8 has
+not been made the default since there are many Perl scripts out there
+that are using various national eight-bit character sets, which would
+be illegal in UTF-8.)
+
+See L<perluniintro> for the explanation of the current model,
+and L<utf8> for the current use of the utf8 pragma.
+
=head2 New Unicode Properties
Unicode I<scripts> are now supported. Scripts are similar to (and superior
=head1 Core Enhancements
+=head2 Unicode Overhaul
+
+Unicode in general should be now much more usable than in Perl 5.6.0
+(or even in 5.6.1). Unicode can be used in hash keys, Unicode in
+regular expressions should work now, Unicode in tr/// should work now,
+Unicode in I/O should work now. See L<perluniintro> for introduction
+and L<perlunicode> for details.
+
+=over 4
+
+=item *
+
+The Unicode Character Database coming with Perl has been upgraded
+to Unicode 3.2.0. For more information, see http://www.unicode.org/ .
+[561+] (5.6.1 has UCD 3.0.1.)
+
+=item *
+
+For developers interested in enhancing Perl's Unicode capabilities:
+almost all the UCD files are included with the Perl distribution in
+the F<lib/unicore> subdirectory. The most notable omission, for space
+considerations, is the Unihan database.
+
+=item *
+
+The properties \p{Blank} and \p{SpacePerl} have been added. "Blank" is like
+C isblank(), that is, it contains only "horizontal whitespace" (the space
+character is, the newline isn't), and the "SpacePerl" is the Unicode
+equivalent of C<\s> (\p{Space} isn't, since that includes the vertical
+tabulator character, whereas C<\s> doesn't.)
+
+See "New Unicode Properties" earlier in this document for additional
+information on changes with Unicode properties.
+
+=back
+
=head2 PerlIO is Now The Default
=over 4
That is a literal undef, not an undefined value.
-=item *
-
-The list form of C<open> is now implemented for pipes (at least on UNIX):
-
- open($fh,"-|", 'cat', '/etc/motd')
-
-creates a pipe, and runs the equivalent of exec('cat', '/etc/motd') in
-the child process.
+=back
-=item *
+=head2 ithreads
-If your locale environment variables (LANGUAGE, LC_ALL, LC_CTYPE, LANG)
-contain the strings 'UTF-8' or 'UTF8' (case-insensitive matching),
-the default encoding of your STDIN, STDOUT, and STDERR, and of
-B<any subsequent file open>, is UTF-8.
+The new interpreter threads ("ithreads" for short) implementation of
+multithreading, by Arthur Bergman, replaces the old "5.005 threads"
+implementation. In the ithreads model any data sharing between
+threads must be explicit, as opposed to the model where data sharing
+was implicit. See L<threads> and L<threads::shared>, and
+L<perlthrtut>.
-=back
+As a part of the ithreads implementation Perl will also use
+any necessary and detectable reentrant libc interfaces.
=head2 Restricted Hashes
but the signal may take more time to get heard. Note that breaking
out from potentially blocking operations should still work, though.
-=head2 Unicode Overhaul
-
-Unicode in general should be now much more usable than in Perl 5.6.0
-(or even in 5.6.1). Unicode can be used in hash keys, Unicode in
-regular expressions should work now, Unicode in tr/// should work now,
-Unicode in I/O should work now. See L<perluniintro> for introduction
-and L<perlunicode> for details.
-
-=over 4
-
-=item *
-
-The Unicode Character Database coming with Perl has been upgraded
-to Unicode 3.2.0. For more information, see http://www.unicode.org/ .
-[561+] (5.6.1 has UCD 3.0.1.)
-
-=item *
-
-For developers interested in enhancing Perl's Unicode capabilities:
-almost all the UCD files are included with the Perl distribution in
-the F<lib/unicore> subdirectory. The most notable omission, for space
-considerations, is the Unihan database.
-
-=item *
-
-The properties \p{Blank} and \p{SpacePerl} have been added. "Blank" is like
-C isblank(), that is, it contains only "horizontal whitespace" (the space
-character is, the newline isn't), and the "SpacePerl" is the Unicode
-equivalent of C<\s> (\p{Space} isn't, since that includes the vertical
-tabulator character, whereas C<\s> doesn't.)
-
-See "New Unicode Properties" earlier in this document for additional
-information on changes with Unicode properties.
-
-=back
-
=head2 Understanding of Numbers
In general a lot of fixing has happened in the area of Perl's
=item *
C<threads::shared>, by Arthur Bergman, allows data sharing for
-interpreter threads. In the ithreads model any data sharing between
-threads must be explicit, as opposed to the old 5.005 thread model
-where data sharing was implicit. See L<threads::shared>.
+interpreter threads. See L<threads::shared>.
=item *
=head1 Known Problems
+=head2 The Compiler Suite Is Still Very Experimental
+
+The compiler suite is slowly getting better but it continues to be
+highly experimental. Use in production environments is discouraged.
+
+=head2 Localising Tied Arrays and Hashes Is Broken
+
+ local %tied_array;
+
+doesn't work as one would expect: the old value is restored
+incorrectly. This will be changed in a future release, but we don't
+know yet what the new semantics will exactly be. In any case, the
+change will break existing code that relies on the current
+(ill-defined) semantics, so just avoid doing this in general.
+
+=head2 Building Extensions Can Fail Because Of Largefiles
+
+Some extensions like mod_perl are known to have issues with
+`largefiles', a change brought by Perl 5.6.0 in which file offsets
+default to 64 bits wide, where supported. Modules may fail to compile
+at all, or they may compile and work incorrectly. Currently, there
+is no good solution for the problem, but Configure now provides
+appropriate non-largefile ccflags, ldflags, libswanted, and libs
+in the %Config hash (e.g., $Config{ccflags_nolargefiles}) so the
+extensions that are having problems can try configuring themselves
+without the largefileness. This is admittedly not a clean solution,
+and the solution may not even work at all. One potential failure is
+whether one can (or, if one can, whether it's a good idea to) link
+together at all binaries with different ideas about file offsets;
+all this is platform-dependent.
+
+=head2 Modifying $_ Inside for(..)
+
+ for (1..5) { $_++ }
+
+works without complaint. It shouldn't. (You should be able to
+modify only lvalue elements inside the loops.) You can see the
+correct behaviour by replacing the 1..5 with 1, 2, 3, 4, 5.
+
+=head2 mod_perl 1.26 Doesn't Build With Threaded Perl
+
+Use mod_perl 1.27 or higher.
+
+=head2 lib/ftmp-security tests warn 'system possibly insecure'
+
+Don't panic. Read the 'make test' section of INSTALL instead.
+
+=head2 libwww-perl (LWP) fails base/date #51
+
+Use libwww-perl 5.65 or later.
+
+=head2 PDL failing some tests
+
+Use PDL 2.3.4 or later.
+
+=head2 Perl_get_sv
+
+You may get errors like 'Undefined symbol "Perl_get_sv"' or "can't
+resolve symbol 'Perl_get_sv'", or the symbol may be "Perl_sv_2pv".
+This probably means that you are trying to use an older shared Perl
+library (or extensions linked with such) with Perl 5.8.0 executable.
+Perl used to have such a subroutine, but that is no more the case.
+Check your shared library path, and any shared Perl libraries in those
+directories.
+
+Sometimes this problem may also indicate a partial Perl 5.8.0
+installation, see L</"Mac OS X dyld undefined symbols"> for an
+example and how to deal with it.
+
+=head2 Self-tying Problems
+
+Self-tying of arrays and hashes is broken in rather deep and
+hard-to-fix ways. As a stop-gap measure to avoid people from getting
+frustrated at the mysterious results (core dumps, most often), it is
+forbidden for now (you will get a fatal error even from an attempt).
+
+A change to self-tying of globs has caused them to be recursively
+referenced (see: L<perlobj/"Two-Phased Garbage Collection">). You
+will now need an explicit untie to destroy a self-tied glob. This
+behaviour may be fixed at a later date.
+
+Self-tying of scalars and IO thingies works.
+
+=head2 ext/threads/t/libc
+
+If this test fails, it indicates that your libc (C library) is not
+threadsafe. This particular test stress tests the localtime() call to
+find out whether it is threadsafe. See L<perlthrtut> for more information.
+
+=head2 Failure of Thread (5.005-style) tests
+
+B<Note that support for 5.005-style threading is deprecated,
+experimental and practically unsupported. In 5.10, it is expected
+to be removed. You should migrate your code to ithreads.>
+
+The following tests are known to fail due to fundamental problems in
+the 5.005 threading implementation. These are not new failures--Perl
+5.005_0x has the same bugs, but didn't have these tests.
+
+ ../ext/B/t/xref.t 255 65280 14 12 85.71% 3-14
+ ../ext/List/Util/t/first.t 255 65280 7 4 57.14% 2 5-7
+ ../lib/English.t 2 512 54 2 3.70% 2-3
+ ../lib/FileCache.t 5 1 20.00% 5
+ ../lib/Filter/Simple/t/data.t 6 3 50.00% 1-3
+ ../lib/Filter/Simple/t/filter_only. 9 3 33.33% 1-2 5
+ ../lib/Math/BigInt/t/bare_mbf.t 1627 4 0.25% 8 11 1626-1627
+ ../lib/Math/BigInt/t/bigfltpm.t 1629 4 0.25% 10 13 1628-
+ 1629
+ ../lib/Math/BigInt/t/sub_mbf.t 1633 4 0.24% 8 11 1632-1633
+ ../lib/Math/BigInt/t/with_sub.t 1628 4 0.25% 9 12 1627-1628
+ ../lib/Tie/File/t/31_autodefer.t 255 65280 65 32 49.23% 34-65
+ ../lib/autouse.t 10 1 10.00% 4
+ op/flip.t 15 1 6.67% 15
+
+These failures are unlikely to get fixed as 5.005-style threads
+are considered fundamentally broken. (Basically what happens is that
+competing threads can corrupt shared global state, one good example
+being regular expression engine's state.)
+
+=head2 Timing problems
+
+The following tests may fail intermittently because of timing
+problems, for example if the system is heavily loaded.
+
+ t/op/alarm.t
+ ext/Time/HiRes/HiRes.t
+ lib/Benchmark.t
+ lib/Memoize/t/expmod_t.t
+ lib/Memoize/t/speed.t
+
+In case of failure please try running them manually, for example
+
+ ./perl -Ilib ext/Time/HiRes/HiRes.t
+
+=head2 Tied/Magical Array/Hash Elements Do Not Autovivify
+
+For normal arrays C<$foo = \$bar[1]> will assign C<undef> to
+C<$bar[1]> (assuming that it didn't exist before), but for
+tied/magical arrays and hashes such autovivification does not happen
+because there is currently no way to catch the reference creation.
+The same problem affects slicing over non-existent indices/keys of
+a tied/magical array/hash.
+
+=head2 Unicode in package/class and subroutine names does not work
+
+One can have Unicode in identifier names, but not in package/class or
+subroutine names. While some limited functionality towards this does
+exist as of Perl 5.8.0, that is more accidental than designed; use of
+Unicode for the said purposes is unsupported.
+
+One reason of this unfinishedness is its (currently) inherent
+unportability: since both package names and subroutine names may
+need to be mapped to file and directory names, the Unicode capability
+of the filesystem becomes important-- and there unfortunately aren't
+portable answers.
+
+=head1 Platform Specific Problems
+
=head2 AIX
=over 4
One can build but not install (or test the build of) the NDBM_File
on FAT filesystems. Installation (or build) on NTFS works fine.
+If one attempts the test on a FAT install (or build) the following
+failures are expected:
-=head2 ext/threads/t/libc
+ ../ext/NDBM_File/ndbm.t 13 3328 71 59 83.10% 1-2 4 16-71
+ ../ext/ODBM_File/odbm.t 255 65280 ?? ?? % ??
+ ../lib/AnyDBM_File.t 2 512 12 2 16.67% 1 4
+ ../lib/Memoize/t/errors.t 0 139 11 5 45.45% 7-11
+ ../lib/Memoize/t/tie_ndbm.t 13 3328 4 4 100.00% 1-4
+ run/fresh_perl.t 97 1 1.03% 91
-If this test fails, it indicates that your libc (C library) is not
-threadsafe. This particular test stress tests the localtime() call to
-find out whether it is threadsafe. See L<perlthrtut> for more information.
+NDBM_File fails and ODBM_File just coredumps.
+
+=head2 DJGPP Failures
+
+ t/op/stat............................FAILED at test 29
+ lib/File/Find/t/find.................FAILED at test 1
+ lib/File/Find/t/taint................FAILED at test 1
+ lib/h2xs.............................FAILED at test 15
+ lib/Pod/t/eol........................FAILED at test 1
+ lib/Test/Harness/t/strap-analyze.....FAILED at test 8
+ lib/Test/Harness/t/test-harness......FAILED at test 23
+ lib/Test/Simple/t/exit...............FAILED at test 1
+
+The above failures are known as of 5.8.0 with native builds with long
+filenames, but there are a few more if running under dosemu because of
+limitations (and maybe bugs) of dosemu:
+
+ t/comp/cpp...........................FAILED at test 3
+ t/op/inccode.........................(crash)
+
+and a few lib/ExtUtils tests, and several hundred Encode/t/Aliases.t
+failures that work fine with long filenames. So you really might
+prefer native builds and long filenames.
=head2 FreeBSD built with ithreads coredumps reading large directories
-This is a known bug in FreeBSD's readdir_r() (see L<perlfreebsd>
-(README.freebsd)), which hopefully will be fixed in FreeBSD 4.6.
+This is a known bug in FreeBSD 4.5's readdir_r(), it has been fixed in
+FreeBSD 4.6 (see L<perlfreebsd> (README.freebsd)).
=head2 FreeBSD Failing locale Test 117 For ISO 8859-15 Locales
the latest FreeBSD releases.
( http://www.freebsd.org/cgi/query-pr.cgi?pr=34308 )
-=head2 IRIX fails ext/List/Util/t/shuffle.t
+=head2 IRIX fails ext/List/Util/t/shuffle.t or Digest::MD5
-IRIX with MIPSpro 7.3.1.3m compiler may fail the said List::Util test
-by dumping core. This seems to be a compiler error since if compiled
-with gcc no core dump ensues, and no failures on the said test on any
-other platform.
+IRIX with MIPSpro 7.3.1.2m or 7.3.1.3m compiler may fail the List::Util
+test ext/List/Util/t/shuffle.t by dumping core. This seems to be
+a compiler error since if compiled with gcc no core dump ensues, and
+no failures have been seen on the said test on any other platform.
-=head2 Modifying $_ Inside for(..)
-
- for (1..5) { $_++ }
-
-works without complaint. It shouldn't. (You should be able to
-modify only lvalue elements inside the loops.) You can see the
-correct behaviour by replacing the 1..5 with 1, 2, 3, 4, 5.
-
-=head2 mod_perl 1.26 Doesn't Build With Threaded Perl
-
-Use mod_perl 1.27 or higher.
-
-=head2 lib/ftmp-security tests warn 'system possibly insecure'
+Similarly, building the Digest::MD5 extension has been
+known to fail with "*** Termination code 139 (bu21)".
-Don't panic. Read the 'make test' section of INSTALL instead.
+The cure is to drop optimization level (Configure -Doptimize=-O2).
=head2 HP-UX lib/posix Subtest 9 Fails When LP64-Configured
No known fix.
-=head2 libwww-perl (LWP) fails base/date #51
-
-Use libwww-perl 5.65 or later.
-
=head2 Mac OS X
Please remember to set your environment variable LC_ALL to "C"
(in this particular test, the localtime() call is found to be
threadunsafe.)
+=head2 Mac OS X dyld undefined symbols
+
+If after installing Perl 5.8.0 you are getting warnings about missing
+symbols, for example
+
+ dyld: perl Undefined symbols
+ _perl_sv_2pv
+ _perl_get_sv
+
+you probably have an old pre-Perl-5.8.0 installation (or parts of one)
+in /Library/Perl (the undefined symbols used to exist in pre-5.8.0 Perls).
+It seems that for some reason "make install" doesn't always completely
+overwrite the files in /Library/Perl. You can move the old Perl
+shared library out of the way like this:
+
+ cd /Library/Perl/darwin/CORE
+ mv libperl.dylib libperlold.dylib
+
+and then reissue "make install". Note that the above of course is
+extremely disruptive for anything using the /usr/local/bin/perl.
+If that doesn't help, you may have to try removing all the .bundle
+files from beneath /Library/Perl, and again "make install"-ing.
+
=head2 OS/2 Test Failures
The following tests are known to fail on OS/2 (for clarity
signedness handling of the C compiler, as do the 64bitint, arith, and pow
failures. Most of the rest point at problems with SysV IPC.
-=head2 PDL failing some tests
-
-Use PDL 2.3.4 or later.
-
=head2 Term::ReadKey not working on Win32
Use Term::ReadKey 2.20 or later.
-=head2 Failure of Thread (5.005-style) tests
-
-B<Note that support for 5.005-style threading is deprecated,
-experimental and practically unsupported. In 5.10, it is expected
-to be removed. You should migrate your code to ithreads.>
-
-The following tests are known to fail due to fundamental problems in
-the 5.005 threading implementation. These are not new failures--Perl
-5.005_0x has the same bugs, but didn't have these tests.
-
- ../ext/B/t/xref.t 255 65280 14 12 85.71% 3-14
- ../ext/List/Util/t/first.t 255 65280 7 4 57.14% 2 5-7
- ../lib/English.t 2 512 54 2 3.70% 2-3
- ../lib/FileCache.t 5 1 20.00% 5
- ../lib/Filter/Simple/t/data.t 6 3 50.00% 1-3
- ../lib/Filter/Simple/t/filter_only. 9 3 33.33% 1-2 5
- ../lib/Math/BigInt/t/bare_mbf.t 1627 4 0.25% 8 11 1626-1627
- ../lib/Math/BigInt/t/bigfltpm.t 1629 4 0.25% 10 13 1628-
- 1629
- ../lib/Math/BigInt/t/sub_mbf.t 1633 4 0.24% 8 11 1632-1633
- ../lib/Math/BigInt/t/with_sub.t 1628 4 0.25% 9 12 1627-1628
- ../lib/Tie/File/t/31_autodefer.t 255 65280 65 32 49.23% 34-65
- ../lib/autouse.t 10 1 10.00% 4
- op/flip.t 15 1 6.67% 15
-
-These failures are unlikely to get fixed as 5.005-style threads
-are considered fundamentally broken. (Basically what happens is that
-competing threads can corrupt shared global state, one good example
-being regular expression engine's state.)
-
-=head2 Timing problems
-
-The following tests may fail intermittently because of timing
-problems, for example if the system is heavily loaded.
-
- t/op/alarm.t
- ext/Time/HiRes/HiRes.t
- lib/Benchmark.t
- lib/Memoize/t/expmod_t.t
- lib/Memoize/t/speed.t
-
-In case of failure please try running them manually, for example
-
- ./perl -Ilib ext/Time/HiRes/HiRes.t
-
-=head2 Unicode in package/class and subroutine names does not work
-
-One can have Unicode in identifier names, but not in package/class or
-subroutine names. While some limited functionality towards this does
-exist as of Perl 5.8.0, that is more accidental than designed; use of
-Unicode for the said purposes is unsupported.
-
-One reason of this unfinishedness is its (currently) inherent
-unportability: since both package names and subroutine names may
-need to be mapped to file and directory names, the Unicode capability
-of the filesystem becomes important-- and there unfortunately aren't
-portable answers.
-
=head2 UNICOS/mk
=over 4
=head2 z/OS (OS/390)
-z/OS has rather many test failures but the situation is actually
+z/OS has rather many test failures but the situation is actually much
better than it was in 5.6.0; it's just that so many new modules and
tests have been added.
110-111 150 161
../lib/ExtUtils/t/Constant.t 121 30976 48 48 100.00% 1-48
../lib/ExtUtils/t/Embed.t 9 9 100.00% 1-9
- op/pat.t 0 11 922 283 30.69% 640-922
+ op/pat.t 922 7 0.76% 665 776 785 832-
+ 834 845
op/sprintf.t 224 3 1.34% 98 100 136
op/tr.t 97 5 5.15% 63 71-74
uni/fold.t 780 6 0.77% 61 169 196 661
the tests (since they test Perl's ability to build extensions, and
that seems to be working reasonably well.)
-=head2 Localising Tied Arrays and Hashes Is Broken
-
- local %tied_array;
-
-doesn't work as one would expect: the old value is restored
-incorrectly. This will be changed in a future release, but we don't
-know yet what the new semantics will exactly be. In any case, the
-change will break existing code that relies on the current
-(ill-defined) semantics, so just avoid doing this in general.
-
-=head2 Self-tying Problems
-
-Self-tying of arrays and hashes is broken in rather deep and
-hard-to-fix ways. As a stop-gap measure to avoid people from getting
-frustrated at the mysterious results (core dumps, most often), it is
-forbidden for now (you will get a fatal error even from an attempt).
-
-A change to self-tying of globs has caused them to be recursively
-referenced (see: L<perlobj/"Two-Phased Garbage Collection">). You
-will now need an explicit untie to destroy a self-tied glob. This
-behaviour may be fixed at a later date.
-
-Self-tying of scalars and IO thingies works.
-
-=head2 Tied/Magical Array/Hash Elements Do Not Autovivify
-
-For normal arrays C<$foo = \$bar[1]> will assign C<undef> to
-C<$bar[1]> (assuming that it didn't exist before), but for
-tied/magical arrays and hashes such autovivification does not happen
-because there is currently no way to catch the reference creation.
-The same problem affects slicing over non-existent indices/keys of
-a tied/magical array/hash.
-
-=head2 Building Extensions Can Fail Because Of Largefiles
-
-Some extensions like mod_perl are known to have issues with
-`largefiles', a change brought by Perl 5.6.0 in which file offsets
-default to 64 bits wide, where supported. Modules may fail to compile
-at all, or they may compile and work incorrectly. Currently, there
-is no good solution for the problem, but Configure now provides
-appropriate non-largefile ccflags, ldflags, libswanted, and libs
-in the %Config hash (e.g., $Config{ccflags_nolargefiles}) so the
-extensions that are having problems can try configuring themselves
-without the largefileness. This is admittedly not a clean solution,
-and the solution may not even work at all. One potential failure is
-whether one can (or, if one can, whether it's a good idea to) link
-together at all binaries with different ideas about file offsets;
-all this is platform-dependent.
-
=head2 Unicode Support on EBCDIC Still Spotty
Though mostly working, Unicode support still has problem spots on
regular expression constructs for code points less than 256: the
C<pP> are testing for Unicode code points, not knowing about EBCDIC.
-=head2 The Compiler Suite Is Still Very Experimental
-
-The compiler suite is slowly getting better but it continues to be
-highly experimental. Use in production environments is discouraged.
-
-=head2 The Long Double Support Is Still Experimental
-
-The ability to configure Perl's numbers to use "long doubles",
-floating point numbers of hopefully better accuracy, is still
-experimental. The implementations of long doubles are not yet
-widespread and the existing implementations are not quite mature
-or standardised, therefore trying to support them is a rare
-and moving target. The gain of more precision may also be offset
-by slowdown in computations (more bits to move around, and the
-operations are more likely to be executed by less optimised
-libraries).
-
=head2 Seen In Perl 5.7 But Gone Now
C<Time::Piece> (previously known as C<Time::Object>) was removed
projects / p5sagit/p5-mst-13.2.git / blobdiff