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perl588delta
(source,CPAN)
You are viewing the version of this documentation from Perl 5.20.1.View the latest version

CONTENTS

#NAME

perl588delta - what is new for perl v5.8.8

#DESCRIPTION

This document describes differences between the 5.8.7 release and the 5.8.8 release.

#Incompatible Changes

There are no changes intentionally incompatible with 5.8.7. If any exist, they are bugs and reports are welcome.

#Core Enhancements

#Modules and Pragmata

#Utility Changes

#h2xs enhancements

h2xs implements new option--use-xsloader to force use ofXSLoader even in backwards compatible modules.

The handling of authors' names that had apostrophes has been fixed.

Any enums with negative values are now skipped.

#perlivp enhancements

perlivp implements new option-a and will not check for*.ph files by default any more. Use the-a option to runall tests.

#New Documentation

Theperlglossary manpage is a glossary of terms used in the Perl documentation, technical and otherwise, kindly provided by O'Reilly Media, inc.

#Performance Enhancements

#Installation and Configuration Improvements

Parallel makes should work properly now, although there may still be problems ifmake test is instructed to run in parallel.

Building with Borland's compilers on Win32 should work more smoothly. In particular Steve Hay has worked to side step many warnings emitted by their compilers and at least one C compiler internal error.

Configure will now detectclearenv andunsetenv, thanks to a patch from Alan Burlison. It will also probe forfutimes and whethersprintf correctly returns the length of the formatted string, which will both be used in perl 5.8.9.

There are improved hints for next-3.0, vmesa, IX, Darwin, Solaris, Linux, DEC/OSF, HP-UX and MPE/iX

Perl extensions on Windows now can be statically built into the Perl DLL, thanks to a work by Vadim Konovalov. (This improvement was actually in 5.8.7, but was accidentally omitted fromperl587delta).

#Selected Bug Fixes

#no warnings 'category' works correctly with -w

Previously when running with warnings enabled globally via-w, selective disabling of specific warning categories would actually turn off all warnings. This is now fixed; nowno warnings 'io'; will only turn off warnings in theio class. Previously it would erroneously turn off all warnings.

This bug fix may cause some programs to start correctly issuing warnings.

#Remove over-optimisation

Perl 5.8.4 introduced a change so that assignments ofundef to a scalar, or of an empty list to an array or a hash, were optimised away. As this could cause problems whengoto jumps were involved, this change has been backed out.

#sprintf() fixes

Using the sprintf() function with some formats could lead to a buffer overflow in some specific cases. This has been fixed, along with several other bugs, notably in bounds checking.

In related fixes, it was possible for badly written code that did not follow the documentation ofSys::Syslog to have formatting vulnerabilities.Sys::Syslog has been changed to protect people from poor quality third party code.

#Debugger and Unicode slowdown

It had been reported that running under perl's debugger when processing Unicode data could cause unexpectedly large slowdowns. The most likely cause of this was identified and fixed by Nicholas Clark.

#Smaller fixes

#New or Changed Diagnostics

#Attempt to set length of freed array

This is a new warning, produced in situations such as this:

$r = do {my @a; \$#a};$$r = 503;

#Non-string passed as bitmask

This is a new warning, produced when number has been passed as a argument to select(), instead of a bitmask.

# Wrong, will now warn$rin = fileno(STDIN);($nfound,$timeleft) = select($rout=$rin, undef, undef, $timeout);# Should be$rin = '';vec($rin,fileno(STDIN),1) = 1;($nfound,$timeleft) = select($rout=$rin, undef, undef, $timeout);

#Search pattern not terminated or ternary operator parsed as search pattern

This syntax error indicates that the lexer couldn't find the final delimiter of a?PATTERN? construct. Mentioning the ternary operator in this error message makes it easier to diagnose syntax errors.

#Changed Internals

There has been a fair amount of refactoring of theC source code, partly to make it tidier and more maintainable. The resulting object code and theperl binary may well be smaller than 5.8.7, in particular due to a change contributed by Dave Mitchell which reworked the warnings code to be significantly smaller. Apart from being smaller and possibly faster, there should be no user-detectable changes.

Andy Lester supplied many improvements to determine which function parameters and local variables could actually be declaredconst to the C compiler. Steve Peters provided new*_set macros and reworked the core to use these rather than assigning to macros in LVALUE context.

Dave Mitchell improved the lexer debugging output under-DT

Nicholas Clark changed the string buffer allocation so that it is now rounded up to the next multiple of 4 (or 8 on platforms with 64 bit pointers). This should reduce the number of calls torealloc without actually using any extra memory.

TheHV's array ofHE*s is now allocated at the correct (minimal) size, thanks to another change by Nicholas Clark. Compile with-DPERL_USE_LARGE_HV_ALLOC to use the old, sloppier, default.

For XS or embedding debugging purposes, if perl is compiled with-DDEBUG_LEAKING_SCALARS_FORK_DUMP in addition to-DDEBUG_LEAKING_SCALARS then a child process isforked just before global destruction, which is used to display the values of any scalars found to have leaked at the end of global destruction. Without this, the scalars have already been freed sufficiently at the point of detection that it is impossible to produce any meaningful dump of their contents. This feature was implemented by the indefatigable Nicholas Clark, based on an idea by Mike Giroux.

#Platform Specific Problems

The optimiser on HP-UX 11.23 (Itanium 2) is currently partly disabled (scaled down to +O1) when using HP C-ANSI-C; the cause of problems at higher optimisation levels is still unclear.

There are a handful of remaining test failures on VMS, mostly due to test fixes and minor module tweaks with too many dependencies to integrate into this release from the development stream, where they have all been corrected. The following is a list of expected failures with the patch number of the fix where that is known:

ext/Devel/PPPort/t/ppphtest.t  #26913ext/List/Util/t/p_tainted.t    #26912lib/ExtUtils/t/PL_FILES.t      #26813lib/ExtUtils/t/basic.t         #26813t/io/fs.tt/op/cmp.t

#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.org, the Perl Home Page.

If you believe you have an unreported bug, please run theperlbug 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 ofperl -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/

#SEE ALSO

TheChanges file for exhaustive details on what changed.

TheINSTALL file for how to build Perl.

TheREADME file for general stuff.

TheArtistic andCopying files for copyright information.

Perldoc Browser is maintained by Dan Book (DBOOK). Please contact him via theGitHub issue tracker oremail regarding any issues with the site itself, search, or rendering of documentation.

The Perl documentation is maintained by the Perl 5 Porters in the development of Perl. Please contact them via thePerl issue tracker, themailing list, orIRC to report any issues with the contents or format of the documentation.

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