64-bit platforms and malloc¶

If your pointers are 64 bits wide, the Perl malloc is no more being used because it simply does not work with 8-byte pointers. Also, usually the system malloc on such platforms are much better optimized for such large memory models than the Perl malloc.

AIX Dynaloading¶

The AIX dynaloading now uses in AIX releases 4.3 and newer the native dlopen interface of AIX instead of the old emulated interface. This change will probably break backward compatibility with compiled modules. The change was made to make Perl more compliant with other applications like modperl which are using the AIX native interface.

Socket Extension Dynamic in VMS¶

The Socket extension is now dynamically loaded instead of being statically built in. This may or may not be a problem with ancient TCP/IP stacks of VMS: we do not know since we weren't able to test Perl in such configurations.

Different Definition of the Unicode Character Classes \p{In...}¶

As suggested by the Unicode consortium, the Unicode character classes now prefer scripts as opposed to blocks (as defined by Unicode); in Perl, when the "\p{In....}" and the "\p{In....}" regular expression constructs are used. This has changed the definition of some of those character classes.

The difference between scripts and blocks is that scripts are the glyphs used by a language or a group of languages, while the blocks are more artificial groupings of 256 characters based on the Unicode numbering.

In general this change results in more inclusive Unicode character classes, but changes to the other direction also do take place: for example while the script "Latin" includes all the Latin characters and their various diacritic-adorned versions, it does not include the various punctuation or digits (since they are not solely "Latin").

Changes in the character class semantics may have happened if a script and a block happen to have the same name, for example "Hebrew". In such cases the script wins and "\p{InHebrew}" now means the script definition of Hebrew. The block definition in still available, though, by appending "Block" to the name: "\p{InHebrewBlock}" means what "\p{InHebrew}" meant in perl 5.6.0. For the full list of affected character classes, see "Blocks" in perlunicode.

Deprecations¶

The current user-visible implementation of pseudo-hashes (the weird use of the first array element) is deprecated starting from Perl 5.8.0 and will be removed in Perl 5.10.0, and the feature will be implemented differently. Not only is the current interface rather ugly, but the current implementation slows down normal array and hash use quite noticeably. The "fields" pragma interface will remain available.

The syntaxes "@a->[...]" and "@h->{...}" have now been deprecated.

The suidperl is also considered to be too much a risk to continue maintaining and the suidperl code is likely to be removed in a future release.

The "package;" syntax ("package" without an argument has been deprecated. Its semantics were never that clear and its implementation even less so. If you have used that feature to disallow all but fully qualified variables, "use strict;" instead.

The chdir(undef) and chdir('') behaviors to match chdir() has been deprecated. In future versions, chdir(undef) and chdir('') will simply fail.

New Modules and Distributions¶

• Attribute::Handlers - Simpler definition of attribute handlers
• ExtUtils::Constant - generate XS code to import C header constants
• I18N::Langinfo - query locale information
• I18N::LangTags - functions for dealing with RFC3066-style language tags
• libnet - a collection of perl5 modules related to network programming

  Perl installation leaves libnet unconfigured, use libnetcfg to configure.

• List::Util - selection of general-utility list subroutines
• Locale::Maketext - framework for localization
• Memoize - Make your functions faster by trading space for time
• NEXT - pseudo-class for method redispatch
• Scalar::Util - selection of general-utility scalar subroutines
• Test::More - yet another framework for writing test scripts
• Test::Simple - Basic utilities for writing tests
• Time::HiRes - high resolution ualarm, usleep, and gettimeofday
• Time::Piece - Object Oriented time objects

  (Previously known as Time::Object.)

• Time::Seconds - a simple API to convert seconds to other date values
• UnicodeCD - Unicode Character Database

Updated And Improved Modules and Pragmata¶

• B::Deparse module has been significantly enhanced. It now can deparse almost all of the standard test suite (so that the tests still succeed). There is a make target "test.deparse" for trying this out.
• Class::Struct now assigns the array/hash element if the accessor is called with an array/hash element as the sole argument.
• Cwd extension is now (even) faster.
• DB_File extension has been updated to version 1.77.
• Fcntl, Socket, and Sys::Syslog have been rewritten to use the new-style constant dispatch section (see ExtUtils::Constant).
• File::Find is now (again) reentrant. It also has been made more portable.
• File::Glob now supports "GLOB_LIMIT" constant to limit the size of the returned list of filenames.
• IO::Socket::INET now supports "LocalPort" of zero (usually meaning that the operating system will make one up.)
• The vars pragma now supports declaring fully qualified variables. (Something that "our()" does not and will not support.)

New Or Improved Platforms¶

• AIX should now work better with gcc, threads, and 64-bitness. Also the long doubles support in AIX should be better now. See perlaix.
• AtheOS ( http://www.atheos.cx/ ) is a new platform.
• DG/UX platform now supports the 5.005-style threads. See perldgux.
• DYNIX/ptx platform (a.k.a. dynixptx) is supported at or near osvers 4.5.2.
• Several Mac OS (Classic) portability patches have been applied. We hope to get a fully working port by 5.8.0. (The remaining problems relate to the changed IO model of Perl.) See perlmacos.
• Mac OS X (or Darwin) should now be able to build Perl even on HFS+ filesystems. (The case-insensitivity confused the Perl build process.)
• NetWare from Novell is now supported. See perlnetware.
• The Amdahl UTS UNIX mainframe platform is now supported.

Generic Improvements¶

• In AFS installations one can configure the root of the AFS to be somewhere else than the default /afs by using the Configure parameter "-Dafsroot=/some/where/else".
• The version of Berkeley DB used when the Perl (and, presumably, the DB_File extension) was built is now available as @Config{qw(db_version_major db_version_minor db_version_patch)} from Perl and as "DB_VERSION_MAJOR_CFG DB_VERSION_MINOR_CFG DB_VERSION_PATCH_CFG" from C.
• The Thread extension is now not built at all under ithreads ("Configure -Duseithreads") because it wouldn't work anyway (the Thread extension requires being Configured with "-Duse5005threads").
• The "B::Deparse" compiler backend has been so significantly improved that almost the whole Perl test suite passes after being deparsed. A make target has been added to help in further testing: "make test.deparse".

Platform Specific Changes and Fixes¶

•

Some versions of glibc have a broken modfl(). This affects builds with "-Duselongdouble". This version of Perl detects this brokenness and has a workaround for it. The glibc release 2.2.2 is known to have fixed the modfl() bug.

MAGIC constants¶

The MAGIC constants (e.g. 'P') have been macrofied (e.g. "PERL_MAGIC_TIED") for better source code readability and maintainability.

Better commented code¶

perly.c, sv.c, and sv.h have now been extensively commented.

Regex pre-/post-compilation items matched up¶

The regex compiler now maintains a structure that identifies nodes in the compiled bytecode with the corresponding syntactic features of the original regex expression. The information is attached to the new "offsets" member of the "struct regexp". See perldebguts for more complete information.

gcc -Wall¶

The C code has been made much more "gcc -Wall" clean. Some warning messages still remain, though, so if you are compiling with gcc you will see some warnings about dubious practices. The warnings are being worked on.

AIX¶

• In AIX 4.2 Perl extensions that use C++ functions that use statics may have problems in that the statics are not getting initialized. In newer AIX releases this has been solved by linking Perl with the libC_r library, but unfortunately in AIX 4.2 the said library has an obscure bug where the various functions related to time (such as time() and gettimeofday()) return broken values, and therefore in AIX 4.2 Perl is not linked against the libC_r.
• vac 5.0.0.0 May Produce Buggy Code For Perl

  The AIX C compiler vac version 5.0.0.0 may produce buggy code, resulting in few random tests failing, but when the failing tests are run by hand, they succeed. We suggest upgrading to at least vac version 5.0.1.0, that has been known to compile Perl correctly. "lslpp -L|grep vac.C" will tell you the vac version.

Amiga Perl Invoking Mystery¶

One cannot call Perl using the "volume:" syntax, that is, "perl -v" works, but for example "bin:perl -v" doesn't. The exact reason is known but the current suspect is the ixemul library.

lib/ftmp-security tests warn 'system possibly insecure'¶

Don't panic. Read INSTALL 'make test' section instead.

Cygwin intermittent failures of lib/Memoize/t/expire_file 11 and 12¶

The subtests 11 and 12 sometimes fail and sometimes work.

HP-UX lib/io_multihomed Fails When LP64-Configured¶

The lib/io_multihomed test may hang in HP-UX if Perl has been configured to be 64-bit. Because other 64-bit platforms do not hang in this test, HP-UX is suspect. All other tests pass in 64-bit HP-UX. The test attempts to create and connect to "multihomed" sockets (sockets which have multiple IP addresses).

HP-UX lib/posix Subtest 9 Fails When LP64-Configured¶

If perl is configured with -Duse64bitall, the successful result of the subtest 10 of lib/posix may arrive before the successful result of the subtest 9, which confuses the test harness so much that it thinks the subtest 9 failed.

Linux With Sfio Fails op/misc Test 48¶

No known fix.

OS/390¶

OS/390 has rather many test failures but the situation is actually better than it was in 5.6.0, it's just that so many new modules and tests have been added.

 Failed Test                     Stat Wstat Total Fail  Failed  List of Failed
 -----------------------------------------------------------------------------
 ../ext/B/Deparse.t                            14    1   7.14%  14
 ../ext/B/Showlex.t                             1    1 100.00%  1
 ../ext/Encode/Encode/Tcl.t                   610   13   2.13%  592 594 596 598
                                                                600 602 604-610
 ../ext/IO/lib/IO/t/io_unix.t     113 28928     5    3  60.00%  3-5
 ../ext/POSIX/POSIX.t                          29    1   3.45%  14
 ../ext/Storable/t/lock.t         255 65280     5    3  60.00%  3-5
 ../lib/locale.t                  129 33024   117   19  16.24%  99-117
 ../lib/warnings.t                            434    1   0.23%  75
 ../lib/ExtUtils.t                             27    1   3.70%  25
 ../lib/Math/BigInt/t/bigintpm.t             1190    1   0.08%  1145
 ../lib/Unicode/UCD.t                          81   48  59.26%  1-16 49-64 66-81
 ../lib/User/pwent.t                            9    1  11.11%  4
 op/pat.t                                     660    6   0.91%  242-243 424-425
                                                                626-627
 op/split.t                         0     9    ??   ??       %  ??
 op/taint.t                                   174    3   1.72%  156 162 168
 op/tr.t                                       70    3   4.29%  50 58-59
 Failed 16/422 test scripts, 96.21% okay. 105/23251 subtests failed, 99.55% okay.

op/sprintf tests 129 and 130¶

The op/sprintf tests 129 and 130 are known to fail on some platforms. Examples include any platform using sfio, and Compaq/Tandem's NonStop-UX. The failing platforms do not comply with the ANSI C Standard, line 19ff on page 134 of ANSI X3.159 1989 to be exact. (They produce something other than "1" and "-1" when formatting 0.6 and -0.6 using the printf format "%.0f", most often they produce "0" and "-0".)

Failure of Thread tests¶

Note that support for 5.005-style threading remains experimental.

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.

  lib/autouse.t                 4
  t/lib/thr5005.t               19-20

UNICOS¶

• ext/POSIX/sigaction subtests 6 and 13 may fail.
• lib/ExtUtils may spuriously claim that subtest 28 failed, which is interesting since the test only has 27 tests.
• Numerous numerical test failures

    op/numconvert                 209,210,217,218
    op/override                   7
    ext/Time/HiRes/HiRes          9
    lib/Math/BigInt/t/bigintpm    1145
    lib/Math/Trig                 25
      

  These tests fail because of yet unresolved floating point inaccuracies.

UTS¶

There are a few known test failures, see perluts.

VMS¶

Rather many tests are failing in VMS but that actually more tests succeed in VMS than they used to, it's just that there are many, many more tests than there used to be.

Here are the known failures from some compiler/platform combinations.

DEC C V5.3-006 on OpenVMS VAX V6.2

  [-.ext.list.util.t]tainted..............FAILED on test 3
  [-.ext.posix]sigaction..................FAILED on test 7
  [-.ext.time.hires]hires.................FAILED on test 14
  [-.lib.file.find]taint..................FAILED on test 17
  [-.lib.math.bigint.t]bigintpm...........FAILED on test 1183
  [-.lib.test.simple.t]exit...............FAILED on test 1
  [.lib]vmsish............................FAILED on test 13
  [.op]sprintf............................FAILED on test 12
  Failed 8/399 tests, 91.23% okay.

DEC C V6.0-001 on OpenVMS Alpha V7.2-1 and Compaq C V6.2-008 on OpenVMS Alpha V7.1

  [-.ext.list.util.t]tainted..............FAILED on test 3 
  [-.lib.file.find]taint..................FAILED on test 17
  [-.lib.test.simple.t]exit...............FAILED on test 1
  [.lib]vmsish............................FAILED on test 13
  Failed 4/399 tests, 92.48% okay.

Compaq C V6.4-005 on OpenVMS Alpha 7.2.1

  [-.ext.b]showlex........................FAILED on test 1
  [-.ext.list.util.t]tainted..............FAILED on test 3
  [-.lib.file.find]taint..................FAILED on test 17 
  [-.lib.test.simple.t]exit...............FAILED on test 1
  [.lib]vmsish............................FAILED on test 13
  [.op]misc...............................FAILED on test 49
  Failed 6/401 tests, 92.77% okay.

Win32¶

In multi-CPU boxes there are some problems with the I/O buffering: some output may appear twice.

Localising a Tied Variable Leaks Memory¶

    use Tie::Hash;
    tie my %tie_hash => 'Tie::StdHash';
    ...
    local($tie_hash{Foo}) = 1; # leaks

Code like the above is known to leak memory every time the local() is executed.

Self-tying of Arrays and Hashes Is Forbidden¶

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 for now forbidden (you will get a fatal error even from an attempt).

Variable Attributes are not Currently Usable for Tieing¶

This limitation will hopefully be fixed in future. (Subroutine attributes work fine for tieing, see Attribute::Handlers).

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 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) link together at all binaries with different ideas about file offsets, all this is platform-dependent.

The Compiler Suite Is Still Experimental¶

The compiler suite is slowly getting better but is nowhere near working order yet.

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).