[ 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 v5.23.4
+perldelta - what is new for perl v5.23.8
=head1 DESCRIPTION
-This document describes differences between the 5.23.3 release and the 5.23.4
+This document describes differences between the 5.23.7 release and the 5.23.8
release.
-If you are upgrading from an earlier release such as 5.23.2, first read
-L<perl5233delta>, which describes differences between 5.23.2 and 5.23.3.
+If you are upgrading from an earlier release such as 5.23.6, first read
+L<perl5237delta>, which describes differences between 5.23.6 and 5.23.7.
=head1 Notice
[ List each enhancement as a =head2 entry ]
+=head2 More fields provided to C<sigaction> callback with C<SA_SIGINFO>
+
+When passing the C<SA_SIGINFO> flag to L<sigaction|POSIX/sigaction>, the
+C<errno>, C<status>, C<uid>, C<pid>, C<addr> and C<band> fields are now
+included in the hash passed to the handler, if supported by the
+platform.
+
=head1 Security
XXX Any security-related notices go here. In particular, any security
=head1 Incompatible Changes
-=head2 Lexical $_ has been removed
-
-C<my $_> was introduced in Perl v5.10, and subsequently caused much confusion
-with no obvious solution. In Perl v5.18.0, it was made experimental on the
-theory that it would either be removed or redesigned in a less confusing (but
-backward-incompatible) way. Over the following years, no alternatives were
-proposed. The feature has now been removed and will fail to compile.
+XXX For a release on a stable branch, this section aspires to be:
-=head2 Only blanks and tabs are now allowed within C<[...]> within C<(?[...])>.
+ There are no changes intentionally incompatible with 5.XXX.XXX
+ If any exist, they are bugs, and we request that you submit a
+ report. See L</Reporting Bugs> below.
-The experimental Extended Bracketed Character Classes can contain
-regular bracketed character classes within them. These differ from
-regular ones in that white space is generally ignored, unless escaped by
-preceding it with a backslash. The white space that is ignored is now
-limited to just tab C<\t> and SPACE characters. Previously, it was any
-white space. See
-L<perlrecharclass/Extended Bracketed Character Classes>.
+[ List each incompatible change as a =head2 entry ]
=head1 Deprecations
=item *
-XXX
+The overhead of scope entry and exit has been considerably reduced, so
+for example subroutine calls, loops and basic blocks are all faster now.
+This empty function call now takes about a third less time to execute:
+
+ sub f{} f();
=back
L<XXX> has been upgraded from version A.xx to B.yy.
+=item *
+
+L<POSIX> has been upgraded from version 1.59 to 1.60.
+
+It can now export constants for the C<code> value in the hash passed to the
+L<sigaction|POSIX/sigaction> handler when using the C<SA_SIGINFO> flag.
+
=back
=head2 Removed Modules and Pragmata
However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
section.
-=head3 L<XXX>
+=head3 L<perlguts>
=over 4
=item *
-XXX Description of the change here
+A new section has been added, L<perlguts/"Dynamic Scope and the Context
+Stack">, which explains how the perl context stack works.
=back
=item *
-L<"Can't modify non-lvalue subroutine call of &%s"|perldiag/"Can't modify non-lvalue subroutine call of &%s">
-
-This error now reports the name of the non-lvalue subroutine you
-attempted to use as an lvalue.
+XXX Describe change here
=back
XXX
+=item *
+
+The GNU Make makefile for Win32 now supports parallel builds. [perl #126632]
+
+=item *
+
+You can now build perl with MSVC++ on Win32 using GNU Make. [perl #126632]
+
=back
=head1 Platform Support
=over 4
-=item XXX-some-platform
+=item Win32
-XXX
+Builds using Microsoft Visual C++ 2003 and earlier no longer produce
+an "INTERNAL COMPILER ERROR" message. [perl #126045]
-=item Win32
+=back
-=over
+=head1 Internal Changes
+
+XXX Changes which affect the interface available to C<XS> code go here. Other
+significant internal changes for future core maintainers should be noted as
+well.
+
+[ List each change as a =item entry ]
+
+=over 4
=item *
-A new build option C<USE_NO_REGISTRY> has been added to the makefiles. This
-option is off by default, meaning the default is to do Windows registry lookups.
-This option stops Perl from looking inside the registry for anything. For what
-values are looked up in the registry see L<perlwin32>. Internally, in C, the
-name of this option is C<WIN32_NO_REGISTRY>.
+The implementation of perl's context stack system, and its internal API,
+have been heavily reworked. Note that no significant changes have been
+made to any external APIs, but XS code which relies on such internal
+details may need to be fixed. The main changes are:
+
+=over 4
=item *
-The behavior of Perl using C<HKEY_CURRENT_USER\Software\Perl> and
-C<HKEY_LOCAL_MACHINE\Software\Perl> to lookup certain values, including
-C<%ENV> vars starting with C<PERL> has changed. Previously, the 2 keys were
-checked for entries at all times through Perl processes life time even if they
-did not exist. For performance reasons, now, if the root key (i.e.
-C<HKEY_CURRENT_USER\Software\Perl> or C<HKEY_LOCAL_MACHINE\Software\Perl>) does
-not exist at process start time, it will not be checked again for C<%ENV>
-override entries for the remainder of the Perl processes life. This more
-closely matches Unix behaviour in that the enviroment is copied or inherited on
-startup and changing the variable in the parent process or another process or
-editing <.bashrc> will not change the enviromental variable in other existing,
-running, processes.
+The C<PUSHBLOCK()>, C<POPSUB()> etc. macros have been replaced with static
+inline functions such as C<cx_pushblock()>, C<cx_popsub()> etc. These use
+function args rather than implicitly relying on local vars such as
+C<gimme> and C<newsp> being available. Also their functionality has
+changed: in particular, C<cx_popblock()> no longer decrements
+C<cxstack_ix>. The ordering of the steps in the C<pp_leave*> functions
+involving C<cx_popblock()>, C<cx_popsub()> etc. has changed. See the new
+documentation, L<perlguts/"Dynamic Scope and the Context Stack">, for
+details on how to use them.
-=back
+=item *
-=back
+Various macros, which now consistently have a CX_ prefix, have been added:
-=head1 Internal Changes
+ CX_CUR(), CX_LEAVE_SCOPE(), CX_POP()
-XXX Changes which affect the interface available to C<XS> code go here. Other
-significant internal changes for future core maintainers should be noted as
-well.
+or renamed:
-[ List each change as a =item entry ]
+ CX_POP_SAVEARRAY(), CX_DEBUG(), CX_PUSHSUBST() ,CX_POPSUBST()
-=over 4
+=item *
+
+C<cx_pushblock()> now saves C<PL_savestack_ix> and C<PL_tmps_floor>, so
+CMpp_enter*> and C<pp_leave*> no longer do
+
+ ENTER; SAVETMPS; ....; LEAVE
+
+=item *
+
+C<cx_popblock()> now also restores C<PL_curpm>.
+
+=item *
+
+In C<dounwind()> for every context type, the current savestack frame is
+now processed before each context is popped; formerly this was only done
+for sub-like context frames. This action has been removed from
+C<cx_popsub()> and placed into its own macro, C<CX_LEAVE_SCOPE(cx)>, which
+must be called before C<cx_popsub()> etc.
+
+C<dounwind()> now also does a C<cx_popblock()> on the last popped frame
+(formerly it only did the C<cx_popsub()> etc. actions on each frame).
=item *
-L<perlapi/sv_backoff> had its return type changed fron C<int> to C<void>. It
-previously has always returned C<0> since 5.000 stable but that was
-undocumented. Although C<sv_backoff> is marked as public API, XS code is not
-expected to be impacted since the proper API call would be through public API
-C<sv_setsv(sv, &PL_sv_undef)>, or quasi-public C<SvOOK_off>, or non-public
-C<SvOK_off> calls, and the return value of C<sv_backoff> was previously a
-meaningless constant that can be rewritten as C<(sv_backoff(sv),0)>.
+The temps stack is now freed on scope exit; previously, temps created
+during the last statement of a block wouldn't be freed until the next
+C<nextstate> following the block (apart from an existing hack that did
+this for recursive subs in scalar context); and in something like
+C<f(g())>, the temps created by the last statement in C<g()> would
+formerly not be freed until the statement following the return from
+C<f()>.
+
+=item *
+
+Most values that were saved on the savestack on scope entry are now
+saved in suitable new fields in the context struct, and saved and
+restored directly by C<cx_pushfoo()> and C<cx_popfoo()>, which is much
+faster.
+
+=item *
+
+Various context struct fields have been added, removed or modified.
+
+=item *
+
+The handling of C<@_> in C<cx_pushsub()> and C<cx_popsub()> has been
+considerably tidied up, including removing the C<argarray> field from the
+context struct, and extracting out some common (but rarely used) code into
+a separate function, C<clear_defarray()>. Also, useful subsets of
+C<cx_popsub()> which had been unrolled in places like C<pp_goto> have been
+gathered into the new functions C<cx_popsub_args()> and
+C<cx_popsub_common()>.
+
+=item *
+
+C<pp_leavesub> and C<pp_leavesublv> now use the same function as the rest
+of the C<pp_leave*>'s to process return args.
+
+=item *
+
+C<CXp_FOR_PAD> and C<CXp_FOR_GV> flags have been added, and
+C<CXt_LOOP_FOR> has been split into C<CXt_LOOP_LIST>, C<CXt_LOOP_ARY>.
+
+=item *
+
+Some variables formerly declared by C<dMULTICALL> (but not documented) have
+been removed.
+
+=back
+
=back
=item *
-There were places in regular expression patterns where comments
-(C<(?#...)>) weren't allowed, but should have been. This is now fixed.
-[perl #116639]
+Line numbers larger than 2**31-1 but less than 2**32 are no longer
+returned by caller() as negative numbers. [perl #126991]
+
+=item *
+
+C<< unless ( I<assignment> ) >> now properly warns when syntax
+warnings are enabled. [perl #127122]
+
+=item *
+
+Setting an C<ISA> glob to an array reference now properly adds
+C<isaelem> magic to any existing elements. Previously modifying such
+an element would not update the ISA cache, so method calls would call
+the wrong function. Perl would also crash if the C<ISA> glob was
+destroyed, since new code added in 5.23.7 would try to release the
+C<isaelem> magic from the elements. [perl #127351]
+
+=item *
+
+If a here-doc was found while parsing another operator, the parser had
+already read end of file, and the here-doc was not terminated, perl
+could produce an assertion or a segmentation fault. This now reliably
+complains about the unterminated here-doc. [perl #125540]
=back
XXX Generate this with:
- perl Porting/acknowledgements.pl v5.23.3..HEAD
+ perl Porting/acknowledgements.pl v5.23.7..HEAD
=head1 Reporting Bugs
https://perl5.git.perl.org / perl5.git / blobdiff