[ this is a template for a new perldelta file. Any text flagged as XXX needs
to be processed before release. ]
-perldelta - what is new for perl v5.19.1
+perldelta - what is new for perl v5.19.2
=head1 DESCRIPTION
-This document describes differences between the 5.19.0 release and the 5.19.1
+This document describes differences between the 5.19.1 release and the 5.19.2
release.
+If you are upgrading from an earlier release such as 5.19.0, first read
+L<perl5191delta>, which describes differences between 5.19.0 and 5.19.1.
+
=head1 Notice
XXX Any important notices here
XXX Remove this section if inapplicable.
-The following modules will be removed from the core distribution in a future
-release, and will at that time need to be installed from CPAN. Distributions
-on CPAN which require these modules will need to list them as prerequisites.
+The following modules will be removed from the core distribution in a
+future release, and will at that time need to be installed from CPAN.
+Distributions on CPAN which require these modules will need to list them as
+prerequisites.
The core versions of these modules will now issue C<"deprecated">-category
-warnings to alert you to this fact. To silence these deprecation warnings,
+warnings to alert you to this fact. To silence these deprecation warnings,
install the modules in question from CPAN.
Note that these are (with rare exceptions) fine modules that you are encouraged
-to continue to use. Their disinclusion from core primarily hinges on their
+to continue to use. Their disinclusion from core primarily hinges on their
necessity to bootstrapping a fully functional, CPAN-capable Perl installation,
not usually on concerns over their design.
-XXX Note that deprecated modules should be listed here even if they are listed
-as an updated module in the L</Modules and Pragmata> section.
-
=over
-=item *
-
-L<DB> has been updated from 1.05 to 1.06 and L<perl5db.pl> from 1.39_10
-to 1.40. The call depth allowed by default in the debugger is now 1000
-rather than 100.
+XXX Note that deprecated modules should be listed here even if they are listed
+as an updated module in the L</Modules and Pragmata> section.
=back
=item *
-Perl has a new copy-on-write mechanism that avoids the need to copy the
-internal string buffer when assigning from one scalar to another. This
-makes copying large strings appear much faster. Modifying one of the two
-(or more) strings after an assignment will force a copy internally. This
-makes it unnecessary to pass strings by reference for efficiency.
-
-This feature was already available in 5.18.0, but wasn't enabled by
-default. It is the default now, and so you no longer need build perl with
-the F<Configure> argument:
-
- -Accflags=PERL_NEW_COPY_ON_WRITE
-
-It can be disabled (for now) in a perl build with:
-
- -Accflags=PERL_NO_COW
+XXX
=back
=item *
-B::Deparse has been upgraded from version 1.20 to 1.21.
-
-C<foreach my $lexical> is now deparsed correctly with the B<-p> option.
-[RT #117081]
-
-The B<-l> option no longer puts form feeds in the middle of a line when
-outputting C<map> and C<grep> blocks. [RT #117311]
+L<ExtUtils::Embed> has been upgraded from version 1.30 to 1.31
-Elements of C<%#>, such as C<$# {foo}> and C<${#}{foo}> are now deparsed
-correctly. [RT #117531]
+The generated C<C> code now incorporates bug fixes present in
+F<miniperlmain.c>, and has whitespace changes. It now uses
+C<#include "..."> for header files instead of C<< #include <...> >>.
+This should not make any difference, unless programs embedding C<libperl>
+happen to have local and incompatible files named F<EXTERN.h>, F<XSUB.h> or
+F<perl.h>, as these will now be picked up instead of the installed Perl
+headers.
=item *
-File::Spec has been upgraded from version 3.40 to 3.41.
+L<ExtUtils::Miniperl> has been upgraded and given a version of 1.
+Previously it did not have a version number.
-C<tmpdir> now respects changes to environment variables from which the
-temporary directory is derived. [RT #88940]
+C<writemain()> now takes an optional first argument. A reference to a scalar
+is treated as a filename to be opened and written to. Any other reference is
+used as the filehandle to write to. Otherwise the existing default remains,
+to write to C<STDOUT>.
-=item *
+C<writemain()> has been refactored to use functions from L<ExtUtils::Embed>,
+reducing code size and duplication. The internal function C<canon()> has been
+deleted.
-Test::Harness has been upgraded from version 3.26 to 3.28
+=item *
-Memory usage is dramatically reduced. t/harness now uses about 10% of the
-memory used by 3.26 and earlier.
+L<POSIX> has been upgraded from version 1.33 to 1.34.
-C<PERL5LIB> is always propagated to a test's C<@INC>, even under C<-T>.
+C<POSIX::AUTOLOAD> will no longer infinitely recurse if the shared
+object fails to load.
=item *
-Unicode::UCD has been upgraded from version 0.51 to 0.52.
+L<Storable> has been upgraded from version 2.43 to 2.44.
-A function, L<Unicode::UCD/search_invlist()> is now available to do
-search an inversion list or map for a code point.
+Calling C<STORABLE_attach> hooks no longer leaks memory. [perl #118829]
=back
However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
section.
-=head3 L<perltrap>
+=head3 L<perlexperiment>
=over 4
=item *
-There is now a L<JavaScript|perltrap/JavaScript Traps> section.
+Code in regular expressions, regular expression backtracking verbs,
+and lvalue subroutines are no longer listed as experimental. (This
+also affects L<perlre> and L<perlsub>.)
=back
=item *
-L<A sequence of multiple spaces in a charnames alias definition is deprecated|perldiag/"A sequence of multiple spaces in a charnames alias definition is deprecated">
-
-L<Trailing white-space in a charnames alias definition is deprecated|perldiag/"Trailing white-space in a charnames alias definition is deprecated">
-
-These two deprecation warnings involving C<\N{...}> were incorrectly
-implemented. They did not warn by default (now they do) and could not be
-made fatal via C<use warnings FATAL => 'deprecated'> (now they can).
+XXX L<message|perldiag/"message">
=back
entries for each change
Use L<XXX> with program names to get proper documentation linking. ]
-=head3 F<bisect.pl> enhancements
-
-The git bisection tool F<Porting/bisect.pl> has had many enhancements.
+=head3 L<XXX>
=over 4
=item *
-Can optionally run the test case with a timeout.
-
-=item *
-
-Can now run in-place in a clean git checkout.
-
-=item *
-
-Can run the test case under C<valgrind>.
-
-=item *
-
-Can apply user supplied patches and fixes to the source checkout before
-building.
-
-=item *
-
-Now has fixups to enable building several more historical ranges of bleadperl,
-which can be useful for pinpointing the origins of bugs or behaviour changes.
+XXX
=back
-It is provided as part of the source distribution but not installed because
-it is not self-contained as it relies on being run from within a git
-checkout. Note also that it makes no attempt to fix tests, correct runtime
-bugs or make something useful to install - its purpose is to make minimal
-changes to get any historical revision of interest to build and run as close
-as possible to "as-was", and thereby make C<git bisect> easy to use.
-
=head1 Configuration and Compilation
XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
=over 4
-=item Mixed-endian platforms
+=item MidnightBSD
-The code supporting C<pack> and C<unpack> operations on mixed endian
-platforms has been removed. We believe that Perl has long been unable to
-build on mixed endian architectures (such as PDP-11s), so we don't think
-that this change will affect any platforms which are able to build v5.18.0.
+C<objformat> was removed from version 0.4-RELEASE of MidnightBSD and had been
+deprecated on earlier versions. This caused the build environment to be
+erroneously configured for C<a.out> rather than C<elf>. This has been now
+been corrected.
=back
significant internal changes for future core maintainers should be noted as
well.
-=over 4
-
-=item *
-
-Perl's new copy-on-write mechanism (which is now enabled by default),
-allows any C<SvPOK> scalar to be automatically upgraded to a copy-on-write
-scalar when copied. A reference count on the string buffer is stored in
-the string buffer itself.
-
-For example:
-
- $ perl -MDevel::Peek -e'$a="abc"; $b = $a; Dump $a; Dump $b'
- SV = PV(0x260cd80) at 0x2620ad8
- REFCNT = 1
- FLAGS = (POK,IsCOW,pPOK)
- PV = 0x2619bc0 "abc"\0
- CUR = 3
- LEN = 16
- COW_REFCNT = 1
- SV = PV(0x260ce30) at 0x2620b20
- REFCNT = 1
- FLAGS = (POK,IsCOW,pPOK)
- PV = 0x2619bc0 "abc"\0
- CUR = 3
- LEN = 16
- COW_REFCNT = 1
-
-Note that both scalars share the same PV buffer and have a COW_REFCNT
-greater than zero.
-
-This means that XS code which wishes to modify the C<SvPVX()> buffer of an
-SV should call C<SvPV_force()> or similar first, to ensure a valid (and
-unshared) buffer, and to call C<SvSETMAGIC()> afterwards. This in fact has
-always been the case (for example hash keys were already copy-on-write);
-this change just spreads the COW behaviour to a wider variety of SVs.
-
-One important difference is that before 5.18.0, shared hash-key scalars
-used to have the C<SvREADONLY> flag set; this is no longer the case.
-
-This new behaviour can still be disabled by running F<Configure> with
-B<-Accflags=-DPERL_NO_COW>. This option will probably be removed in Perl
-5.22.
-
-=item *
+[ List each change as a =item entry ]
-C<PL_sawampersand> is now a constant. The switch this variable provided
-(to enable/disable the pre-match copy depending on whether C<$&> had been
-seen) has been removed and replaced with copy-on-write, eliminating a few
-bugs.
-
-The previous behaviour can still be enabled by running F<Configure> with
-B<-Accflags=-DPERL_SAWAMPERSAND>.
+=over 4
=item *
-The functions C<my_swap>, C<my_htonl> and C<my_ntohl> have been removed.
-It is unclear why these functions were ever marked as I<A>, part of the
-API. XS code can't call them directly, as it can't rely on them being
-compiled. Unsurprisingly, no code on CPAN references them.
+The Makefile shortcut targets for many rarely (or never) used testing and
+profiling targets have been removed, or merged into the only other Makefile
+target that uses them. Specifically, these targets are gone, along with
+documentation that referenced them or explained how to use them:
-=item *
+ check.third check.utf16 check.utf8 coretest minitest.prep
+ minitest.utf16 perl.config.dashg perl.config.dashpg
+ perl.config.gcov perl.gcov perl.gprof perl.gprof.config perl.pixie
+ perl.pixie.atom perl.pixie.config perl.pixie.irix perl.third
+ perl.third.config pureperl purecovperl quantperl test.deparse
+ test.taintwarn test.third test.torture test.utf16 test.utf8
+ test_notty.deparse test_notty.third test_prep.third torturetest
+ ucheck ucheck.third ucheck.utf16 ucheck.valgrind utest utest.third
+ utest.utf16 utest.valgrind
-The signature of the C<Perl_re_intuit_start()> regex function has changed;
-the function pointer C<intuit> in the regex engine plugin structure
-has also changed accordingly. A new parameter, C<strbeg> has been added;
-this has the same meaning as the same-named parameter in
-C<Perl_regexec_flags>. Previously intuit would try to guess the start of
-the string from the passed SV (if any), and would sometimes get it wrong
-(e.g. with an overloaded SV).
+It's still possible to run the relevant commands by "hand" - no underlying
+functionality has been removed.
=back
=item *
-The OP allocation code now returns correctly aligned memory in all cases
-for C<struct pmop>. Previously it could return memory only aligned to a
-4-byte boundary, which is not correct for an ithreads build with 64 bit IVs
-on some 32 bit platforms. Notably, this caused the build to fail completely
-on sparc GNU/Linux. [RT #118055]
-
-=item *
-
-The debugger's C<man> command been fixed. It was broken in the v5.18.0
-release. The C<man> command is aliased to the names C<doc> and C<perldoc> -
-all now work again.
-
-=item *
-
-Evaluating large hashes in scalar context is now much faster, as the number
-of used chains in the hash is now cached for larger hashes. Smaller hashes
-continue not to store it and calculate it when needed, as this saves one IV.
-That would be 1 IV overhead for every object built from a hash. [RT #114576]
-
-=item *
-
-Fixed a small number of regexp constructions that could either fail to
-match or crash perl when the string being matched against was
-allocated above the 2GB line on 32-bit systems. [RT #118175]
-
-=item *
-
-Perl v5.16 inadvertently introduced a bug whereby calls to XSUBs that were
-not visible at compile time were treated as lvalues and could be assigned
-to, even when the subroutine was not an lvalue sub. This has been fixed.
-[RT #117947]
-
-=item *
-
-In Perl v5.18.0 dualvars that had an empty string for the string part but a
-non-zero number for the number part starting being treated as true. In
-previous versions they were treated as false, the string representation
-taking precedeence. The old behaviour has been restored. [RT #118159]
-
-=item *
-
-Since Perl v5.12, inlining of constants that override built-in keywords of
-the same name had countermanded C<use subs>, causing subsequent mentions of
-the constant to use the built-in keyword instead. This has been fixed.
-
-=item *
-
-Lexical constants (C<my sub a() { 42 }>) no longer crash when inlined.
-
-=item *
-
-Parameter prototypes attached to lexical subroutines are now respected when
-compiling sub calls without parentheses. Previously, the prototypes were
-honoured only for calls I<with> parentheses. [RT #116735]
-
-=item *
-
-Syntax errors in lexical subroutines in combination with calls to the same
-subroutines no longer cause crashes at compile time.
-
-=item *
-
-The warning produced by C<-l $handle> now applies to IO refs and globs, not
-just to glob refs. That warning is also now UTF8-clean. [RT #117595]
-
-=item *
-
-Various memory leaks involving the parsing of the C<(?[...])> regular
-expression construct have been fixed.
-
-=item *
-
-C<(?[...])> now allows interpolation of precompiled patterns consisting of
-(?[...])> with bracket character classes inside (C<$pat =
-S<qr/(?[ [a] ])/;> S</(?[ $pat ])/>>). Formerly, the brackets would
-confuse the regular expression parser.
-
-=item *
-
-C<delete local $ENV{nonexistent_env_var}> no longer leaks memory.
-
-=item *
-
-C<sort> and C<require> followed by a keyword prefixed with C<CORE::> now
-treat it as a keyword, and not as a subroutine or module name. [RT #24482]
-
-=item *
-
-Through certain conundrums, it is possible to cause the current package to
-be freed. Certain operators (C<bless>, C<reset>, C<open>, C<eval>) could
-not cope and would crash. They have been made more resilient. [RT #117941]
-
-=item *
-
-Aliasing filehandles through glob-to-glob assignment would not update
-internal method caches properly if a package of the same name as the
-filehandle existed, resulting in filehandle method calls going to the
-package instead. This has been fixed.
+XXX
=back
https://perl5.git.perl.org / perl5.git / blobdiff