[ 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 v5.17.4
+perldelta - what is new for perl v5.17.7
=head1 DESCRIPTION
-This document describes differences between the 5.17.3 release and the 5.17.4
+This document describes differences between the 5.17.6 release and the 5.17.7
release.
-If you are upgrading from an earlier release such as 5.17.2, first read
-L<perl5173delta>, which describes differences between 5.17.2 and 5.17.3.
+If you are upgrading from an earlier release such as 5.17.5, first read
+L<perl5176delta>, which describes differences between 5.17.5 and 5.17.6.
=head1 Notice
[ List each enhancement as a =head2 entry ]
-=head2 Latest Unicode 6.2 beta is included
-
-This is supposed to be the final data for 6.2, unless glitches are
-found. The earlier experimental 6.2 beta data has been reverted, and
-this used instead. Not all the changes that were proposed for 6.2 and
-that were in the earlier beta versions are actually going into 6.2. In
-particular, there are no changes from 6.1 in the General_Category of any
-characters. 6.2 does revise the C<\X> handling for the REGIONAL
-INDICATOR characters that were added in Unicode 6.0. Perl now for the
-first time fully handles this revision.
-
-=head2 New DTrace probes
-
-The following new DTrace probes have been added:
-
-=over 4
-
-=item C<op-entry>
-
-=item C<loading-file>
-
-=item C<loaded-file>
-
-=back
-
-=head2 C<${^LAST_FH}>
-
-This new variable provides access to the filehandle that was last read.
-This is the handle used by C<$.> and by C<tell> and C<eof> without
-arguments.
-
-=head2 Looser here-doc parsing
-
-Here-doc terminators no longer require a terminating newline character when
-they occur at the end of a file. This was already the case at the end of a
-string eval [perl #65838].
-
-=head2 New mechanism for experimental features
-
-Newly-added experimental features will now require this incantation:
-
- no warnings "experimental:feature_name";
- use feature "feature_name"; # would warn without the prev line
-
-There is a new warnings category, called "experimental", containing
-warnings that the L<feature> pragma emits when enabling experimental
-features.
-
-Newly-added experimental features will also be given special warning IDs,
-which consist of "experimental:" followed by the name of the feature. (The
-plan is to extend this mechanism eventually to all warnings, to allow them
-to be enabled or disabled individually, and not just by category.)
-
-By saying
-
- no warnings "experimental:feature_name";
-
-you are taking responsibility for any breakage that future changes to, or
-removal of, the feature may cause.
-
-=head2 Lexical subroutines
-
-This new feature is still considered experimental. To enable it, use the
-mechanism described above:
-
- use 5.018;
- no warnings "experimental:lexical_subs";
- use feature "lexical_subs";
-
-You can now declare subroutines with C<state sub foo>, C<my sub foo>, and
-C<our sub foo>. (C<state sub> requires that the "state" feature be
-enabled, unless you write it as C<CORE::state sub foo>.)
-
-C<state sub> creates a subroutine visible within the lexical scope in which
-it is declared. The subroutine is shared between calls to the outer sub.
-
-C<my sub> declares a lexical subroutine that is created each time the
-enclosing block is entered. C<state sub> is generally slightly faster than
-C<my sub>.
-
-C<our sub> declares a lexical alias to the package subroutine of the same
-name.
-
-See L<perlsub/Lexical Subroutines>.
-
=head1 Security
XXX Any security-related notices go here. In particular, any security
=head1 Incompatible Changes
+=head2 readline() with C<$/ = \N> now reads N characters, not N bytes
+
+Previously, when reading from a stream with I/O layers such as
+C<encoding>, the readline() function, otherwise known as the C<< <> >>
+operator, would read I<N> bytes from the top-most layer. [perl #79960]
+
+Now, I<N> characters are read instead.
+
+There is no change in behaviour when reading from streams with no
+extra layers, since bytes map exactly to characters.
+
XXX For a release on a stable branch, this section aspires to be:
There are no changes intentionally incompatible with 5.XXX.XXX
[ List each incompatible change as a =head2 entry ]
-=head2 Here-doc parsing
-
-The body of a here-document inside a quote-like operator now always begins
-on the line after the "<<foo" marker. Previously, it was documented to
-begin on the line following the containing quote-like operator, but that
-was only sometimes the case [perl #114040].
-
-=head2 Stricter parsing of substitution replacement
-
-It is no longer possible to abuse the way the parser parses C<s///e> like
-this:
-
- %_=(_,"Just another ");
- $_="Perl hacker,\n";
- s//_}->{_/e;print
-
-=head2 Interaction of lexical and default warnings
-
-Turning on any lexical warnings used first to disable all default warnings
-if lexical warnings were not already enabled:
-
- $*; # deprecation warning
- use warnings "void";
- $#; # void warning; no deprecation warning
-
-Now, the debugging, deprecated, glob, inplace and malloc warnings
-categories are left on when turning on lexical warnings (unless they are
-turned off by C<no warnings>, of course).
-
-This may cause deprecation warnings to occur in code that used to be free
-of warnings.
-
-Those are the only categories consisting only of default warnings. Default
-warnings in other categories are still disabled by C<use warnings
-"category">, as we do not yet have the infrastructure for controlling
-individual warnings.
-
-=head2 C<state sub> and C<our sub>
-
-Due to an accident of history, C<state sub> and C<our sub> were equivalent
-to a plain C<sub>, so one could even create an anonymous sub with
-C<our sub { ... }>. These are now disallowed outside of the "lexical_subs"
-feature. Under the "lexical_subs" feature they have new meanings described
-in L<perlsub/Lexical Subroutines>.
-
-=head2 C<gv_fetchmeth_*> and SUPER
-
-The various C<gv_fetchmeth_*> XS functions used to treat a package whose
-named ended with ::SUPER specially. A method lookup on the Foo::SUPER
-package would be treated as a SUPER method lookup on the Foo package. This
-is no longer the case. To do a SUPER lookup, pass the Foo stash and the
-GV_SUPER flag.
-
=head1 Deprecations
XXX Any deprecated features, syntax, modules etc. should be listed here. In
[ List each deprecation as a =head2 entry ]
+=head2 Various XS-callable functions are now deprecated
+
+The following functions will be removed from a future version of Perl,
+and should not be used. With participating C compilers (e.g., gcc),
+compiling any file that uses any of these will generate a warning.
+These were not intended for public use; there are equivalent, faster,
+macros for most of them. See L<perlapi/Character classes>:
+C<is_uni_ascii>,
+C<is_uni_ascii_lc>,
+C<is_uni_blank>,
+C<is_uni_blank_lc>,
+C<is_uni_cntrl>,
+C<is_uni_cntrl_lc>,
+C<is_uni_idfirst_lc>,
+C<is_uni_space>,
+C<is_uni_space_lc>,
+C<is_uni_xdigit>,
+C<is_uni_xdigit_lc>,
+C<is_utf8_ascii>,
+C<is_utf8_blank>,
+C<is_utf8_cntrl>,
+C<is_utf8_idcont>,
+C<is_utf8_idfirst>,
+C<is_utf8_perl_space>,
+C<is_utf8_perl_word>,
+C<is_utf8_posix_digit>,
+C<is_utf8_space>,
+C<is_utf8_xdigit>.
+C<is_utf8_xidcont>,
+C<is_utf8_xidfirst>,
+C<to_uni_lower_lc>,
+C<to_uni_title_lc>,
+and
+C<to_uni_upper_lc>.
+
=head1 Performance Enhancements
XXX Changes which enhance performance without changing behaviour go here.
=item *
-Speed up in regular expression matching against Unicode properties. The
-largest gain is for C<\X>, the Unicode "extended grapheme cluster". The
-gain for it is about 35% - 40%. Bracketed character classes, e.g.,
-C<[0-9\x{100}]> containing code points above 255 are also now faster.
-
-=item *
-
-On platforms supporting it, several former macros are now implemented as static
-inline functions. This should speed things up slightly on non-GCC platforms.
-
-=item *
-
-Apply the optimisation of hashes in boolean context, such as in C<if> or C<and>,
-to constructs in non-void context.
-
-=item *
-
-Extend the optimisation of hashes in boolean context to C<scalar(%hash)>,
-C<%hash ? ... : ...>, and C<sub { %hash || ... }>.
-
-=item *
-
-When making a copy of the string being matched against (so that $1, $& et al
-continue to show the correct value even if the original string is subsequently
-modified), only copy that substring of the original string needed for the
-capture variables, rather than copying the whole string.
-
-This is a big win for code like
-
- $&;
- $_ = 'x' x 1_000_000;
- 1 while /(.)/;
-
-Also, when pessimizing if the code contains C<$`>, C<$&> or C<$'>, record the
-presence of each variable separately, so that the determination of the substring
-range is based on each variable separately. So performance-wise,
-
- $&; /x/
-
-is now roughly equivalent to
-
- /(x)/
-
-whereas previously it was like
-
- /^(.*)(x)(.*)$/
-
-and
-
- $&; $'; /x/
-
-is now roughly equivalent to
-
- /(x)(.*)$/
-
-etc.
+XXX
=back
=item *
-L<Archive::Tar> has been upgraded from version 1.88 to 1.90. This adds
-documentation fixes.
-
-=item *
-
-L<B> has been upgraded from version 1.37 to 1.38. This makes the module work
-with the new pad API.
-
-=item *
-
-L<B::Concise> has been upgraded from version 0.92 to 0.93. This adds support
-for the new C<OpMAYBE_TRUEBOOL> and C<OPpTRUEBOOL> flags.
-
-=item *
-
-L<B::Deparse> has been upgraded from version 1.16 to 1.17. This suppresses
-trailing semicolons in formats.
-
-=item *
-
-L<DB_File> has been upgraded from version 1.826 to 1.827. The main Perl module
-no longer uses the C<"@_"> construct.
-
-=item *
-
-L<Devel::Peek> has been upgraded from version 1.09 to 1.10. This fixes
-compilation with C++ compilers and makes the module work with the new pad API.
-
-=item *
-
-L<DynaLoader> has been upgraded from version 1.15 to 1.16. This fixes warnings
-about using C<CODE> sections without an C<OUTPUT> section.
-
-=item *
-
-L<ExtUtils::ParseXS> has been upgraded from version 3.17 to 3.18. This avoids a
-bogus warning for initialised XSUB non-parameters [perl #112776].
-
-=item *
-
-L<File::Copy> has been upgraded from version 2.23 to 2.24. C<copy()> no longer
-zeros files when copying into the same directory, and also now fails (as it has
-long been documented to do) when attempting to copy a file over itself.
-
-=item *
-
-L<File::Find> has been upgraded from version 1.21 to 1.22. This fixes
-inconsistent unixy path handling on VMS.
-
-=item *
-
-L<IPC::Open3> has been upgraded from version 1.12 to 1.13. The C<open3()>
-function no longer uses C<POSIX::close()> to close file descriptors since that
-breaks the ref-counting of file descriptors done by PerlIO in cases where the
-file descriptors are shared by PerlIO streams, leading to attempts to close the
-file descriptors a second time when any such PerlIO streams are closed later on.
-
-=item *
-
-L<Locale::Codes> has been upgraded from version 3.22 to 3.23. It includes some
-new codes.
-
-=item *
-
-L<Module::CoreList> has been upgraded from version 2.71 to 2.73. This restores
-compatibility with older versions of perl and cleans up the corelist data for
-various modules.
-
-=item *
-
-L<Opcode> has been upgraded from version 1.23 to 1.24 to reflect the removal of
-the boolkeys opcode and the addition of the clonecv, introcv and padcv
-opcodes.
-
-=item *
-
-L<Socket> has been upgraded from version 2.004 to 2.006.
-C<unpack_sockaddr_in()> and C<unpack_sockaddr_in6()> now return just the IP
-address in scalar context, and C<inet_ntop()> now guards against incorrect
-length scalars being passed in.
-
-=item *
-
-L<Storable> has been upgraded from version 2.38 to 2.39. This contains Various
-bugfixes, including compatibility fixes for older versions of Perl and vstring
-handling.
-
-=item *
-
-L<threads::shared> has been upgraded from version 1.40 to 1.41. This adds the
-option to warn about or ignore attempts to clone structures that can't be
-cloned, as opposed to just unconditionally dying in that case.
-
-=item *
-
-L<XSLoader> has been upgraded from version 0.15 to 0.16.
+L<GDBM_File> has been upgraded from version 1.14 to 1.15. The undocumented
+optional fifth parameter to C<TIEHASH> has been removed. This was intended
+to provide control of the callback used by C<gdbm*> functions in case of
+fatal errors (such as filesystem problems), but did not work (and could
+never have worked). No code on CPAN even attempted to use it. The callback
+is now always the previous default, C<croak>. Problems on some platforms with
+how the C<C> C<croak> function is called have also been resolved.
=back
However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
section.
-=head3 L<XXX>
+=head3 L<perlapi/Character classes>
=over 4
=item *
-XXX Description of the change here
+There are quite a few macros callable from XS modules that classify
+characters into things like alphabetic, punctuation, etc. More of these
+are now documented, including ones which work on characters whose code
+points are outside the Latin-1 range.
=back
=item *
-L<Experimental "%s" subs not enabled|perldiag/"Experimental "%s" subs not enabled">
-
-(F) To use lexical subs, you must first enable them:
-
- no warnings 'experimental:lexical_subs';
- use feature 'lexical_subs';
- my sub foo { ... }
-
-=item *
-
-L<Subroutine "&%s" is not available|perldiag/"Subroutine "&%s" is not available">
-
-(W closure) During compilation, an inner named subroutine or eval is
-attempting to capture an outer lexical subroutine that is not currently
-available. This can happen for one of two reasons. First, the lexical
-subroutine may be declared in an outer anonymous subroutine that has not
-yet been created. (Remember that named subs are created at compile time,
-while anonymous subs are created at run-time.) For example,
-
- sub { my sub a {...} sub f { \&a } }
-
-At the time that f is created, it can't capture the current the "a" sub,
-since the anonymous subroutine hasn't been created yet. Conversely, the
-following won't give a warning since the anonymous subroutine has by now
-been created and is live:
-
- sub { my sub a {...} eval 'sub f { \&a }' }->();
-
-The second situation is caused by an eval accessing a variable that has
-gone out of scope, for example,
-
- sub f {
- my sub a {...}
- sub { eval '\&a' }
- }
- f()->();
-
-Here, when the '\&a' in the eval is being compiled, f() is not currently
-being executed, so its &a is not available for capture.
-
-=item *
-
-L<"%s" subroutine &%s masks earlier declaration in same %s|perldiag/"%s" subroutine &%s masks earlier declaration in same %s>
-
-(W misc) A "my" or "state" subroutine has been redeclared in the
-current scope or statement, effectively eliminating all access to
-the previous instance. This is almost always a typographical error.
-Note that the earlier subroutine will still exist until the end of
-the scope or until all closure references to it are destroyed.
-
-=item *
-
-L<The %s feature is experimental|perldiag/"The %s feature is experimental">
-
-(S experimental) This warning is emitted if you enable an experimental
-feature via C<use feature>. Simply suppress the warning if you want
-to use the feature, but know that in doing so you are taking the risk
-of using an experimental feature which may change or be removed in a
-future Perl version:
-
- no warnings "experimental:lexical_subs";
- use feature "lexical_subs";
+XXX L<message|perldiag/"message">
=back
=item *
-L<vector argument not supported with alpha versions|perldiag/vector argument not supported with alpha versions>
-
-This warning was not suppressable, even with C<no warnings>. Now it is
-suppressible, and has been moved from the "internal" category to the
-"printf" category.
+XXX Describe change here
=back
=item *
-F<Configure> will now correctly detect C<isblank()> when compiling with a C++
-compiler.
+XXX
=back
=head2 Discontinued Platforms
+XXX List any platforms that this version of perl no longer compiles on.
+
=over 4
-=item VM/ESA
+=item XXX-some-platform
-Support for VM/ESA has been removed. The port was tested on 2.3.0, which
-IBM ended service on in March 2002. 2.4.0 ended service in June 2003, and
-was superseded by Z/VM. The current version of Z/VM is V6.2.0, and scheduled
-for end of service on 2015/04/30.
+XXX
=back
=over 4
-=item Win32
-
-Fixed a problem where perl could crash while cleaning up threads (including the
-main thread) in threaded debugging builds on Win32 and possibly other platforms
-[perl #114496].
-
-A rare race condition that would lead to L<sleep|perlfunc/sleep> taking more
-time than requested, and possibly even hanging, has been fixed [perl #33096].
-
-=item Solaris
-
-In Configure, avoid running sed commands with flags not supported on Solaris.
-
-=item Darwin
-
-Stop hardcoding an alignment on 8 byte boundaries to fix builds using
--Dusemorebits.
-
-=item VMS
+=item XXX-some-platform
-Fix linking on builds configured with -Dusemymalloc=y.
+XXX
=back
=item *
-The APIs for accessing lexical pads have changed considerably.
-
-C<PADLIST>s are now longer C<AV>s, but their own type instead. C<PADLIST>s now
-contain a C<PAD> and a C<PADNAMELIST> of C<PADNAME>s, rather than C<AV>s for the
-pad and the list of pad names. C<PAD>s, C<PADNAMELIST>s, and C<PADNAME>s are to
-be accessed as such though the newly added pad API instead of the plain C<AV>
-and C<SV> APIs. See L<perlapi> for details.
-
-=item *
-
-In the regex API, the numbered capture callbacks are passed an index
-indicating what match variable is being accessed. There are special
-index values for the C<$`, $&, $&> variables. Previously the same three
-values were used to retrieve C<${^PREMATCH}, ${^MATCH}, ${^POSTMATCH}>
-too, but these have now been assigned three separate values. See
-L<perlreapi/Numbered capture callbacks>.
-
-=item *
-
-C<PL_sawampersand> was previously a boolean indicating that any of
-C<$`, $&, $&> had been seen; it now contains three one-bit flags
-indicating the presence of each of the variables individually.
+XXX
=back
XXX Important bug fixes in the core language are summarized here. Bug fixes in
files in F<ext/> and F<lib/> are best summarized in L</Modules and Pragmata>.
-=over 4
-
-=item *
-
-The error "Can't localize through a reference" had disappeared in 5.16.0
-when C<local %$ref> appeared on the last line of an lvalue subroutine.
-This error disappeared for C<\local %$ref> in perl 5.8.1. It has now
-been restored.
-
-=item *
-
-The parsing of here-docs has been improved significantly, fixing several
-parsing bugs and crashes and one memory leak, and correcting wrong
-subsequent line numbers under certain conditions.
-
-=item *
-
-Inside an eval, the error message for an unterminated here-doc no longer
-has a newline in the middle of it [perl #70836].
-
-=item *
-
-A substitution inside a substitution pattern (C<s/${s|||}//>) no longer
-confuses the parser.
-
-=item *
-
-It may be an odd place to allow comments, but C<s//"" # hello/e> has
-always worked, I<unless> there happens to be a null character before the
-first #. Now it works even in the presence of nulls.
-
-=item *
-
-An invalid range in C<tr///> or C<y///> no longer results in a memory leak.
-
-=item *
-
-String eval no longer treats a semicolon-delimited quote-like operator at
-the very end (C<eval 'q;;'>) as a syntax error.
-
-=item *
-
-C<< warn {$_ => 1} + 1 >> is no longer a syntax error. The parser used to
-get confused with certain list operators followed by an anonymous hash and
-then an infix operator that shares its form with a unary operator.
-
-=item *
-
-C<(caller $n)[6]> (which gives the text of the eval) used to return the
-actual parser buffer. Modifying it could result in crashes. Now it always
-returns a copy. The string returned no longer has "\n;" tacked on to the
-end. The returned text also includes here-doc bodies, which used to be
-omitted.
-
-=item *
-
-Reset the utf8 position cache when accessing magical variables to avoid the
-string buffer and the utf8 position cache to get out of sync
-[perl #114410].
-
-=item *
-
-Various cases of get magic being called twice for magical utf8 strings have been
-fixed.
-
-=item *
-
-This code (when not in the presence of C<$&> etc)
-
- $_ = 'x' x 1_000_000;
- 1 while /(.)/;
-
-used to skip the buffer copy for performance reasons, but suffered from C<$1>
-etc changing if the original string changed. That's now been fixed.
-
-=item *
-
-Perl doesn't use PerlIO anymore to report out of memory messages, as PerlIO
-might attempt to allocate more memory.
-
-=item *
-
-In a regular expression, if something is quantified with C<{n,m}>
-where C<S<n E<gt> m>>, it can't possibly match. Previously this was a fatal error,
-but now is merely a warning (and that something won't match). [perl #82954].
-
-=item *
-
-It used to be possible for formats defined in subroutines that have
-subquently been undefined and redefined to close over variables in the
-wrong pad (the newly-defined enclosing sub), resulting in crashes or
-"Bizarre copy" errors.
-
-=item *
-
-Redefinition of XSUBs at run time could produce warnings with the wrong
-line number.
-
-=item *
-
-The %vd sprintf format does not support version objects for alpha versions.
-It used to output the format itself (%vd) when passed an alpha version, and
-also emit an "Invalid conversion in printf" warning. It no longer does,
-but produces the empty string in the output. It also no longer leaks
-memory in this case.
-
-=item *
-
-A bug fix in an earlier 5.17.x release caused C<no a a 3> (a syntax error)
-to result in a bad read or assertion failure, because an op was being freed
-twice.
-
-=item *
-
-C<< $obj->SUPER::method >> calls in the main package could fail if the
-SUPER package had already been accessed by other means.
-
-=item *
+[ List each fix as a =item entry ]
-Stash aliasing (C<*foo:: = *bar::>) no longer causes SUPER calls to ignore
-changes to methods or @ISA or use the wrong package.
+=over 4
=item *
-Method calls on packages whose names end in ::SUPER are no longer treated
-as SUPER method calls, resulting in failure to find the method.
-Furthermore, defining subroutines in such packages no longer causes them to
-be found by SUPER method calls on the containing package [perl #114924].
+XXX
=back
=item *
-Changes in the lexical pad API break several CPAN modules.
-
-To avoid having to patch those modules again later if we change pads from AVs
-into their own types, APIs for accessing the contents of pads have been added.
+XXX
=back
XXX Generate this with:
- perl Porting/acknowledgements.pl v5.17.3..HEAD
+ perl Porting/acknowledgements.pl v5.17.6..HEAD
=head1 Reporting Bugs
https://perl5.git.perl.org / perl5.git / blobdiff