diff options
Diffstat (limited to 'Porting')
| -rw-r--r-- | Porting/perl5160delta.pod | 204 |
1 files changed, 191 insertions, 13 deletions
diff --git a/Porting/perl5160delta.pod b/Porting/perl5160delta.pod index 5bd56ae94b..f8ff298451 100644 --- a/Porting/perl5160delta.pod +++ b/Porting/perl5160delta.pod @@ -1713,26 +1713,85 @@ without cc. =item * -There are now feature bundle hints in C<PL_hints> (C<$^H>) that version -declarations use, to avoid having to load F<feature.pm>. One setting of -the hint bits indicates a "custom" feature bundle, which means that the -entries in C<%^H> still apply. F<feature.pm> uses that. +The compiled representation of formats is now stored via the C<mg_ptr> of +their C<PERL_MAGIC_fm>. Previously it was stored in the string buffer, +beyond C<SvLEN()>, the regular end of the string. C<SvCOMPILED()> and +C<SvCOMPILED_{on,off}()> now exist solely for compatibility for XS code. +The first is always 0, the other two now no-ops. (5.14.1) -The C<HINT_FEATURE_MASK> macro is defined in F<perl.h> along with other -hints. Other macros for setting and testing features and bundles are in -the new F<feature.h>. C<FEATURE_IS_ENABLED> (which has moved to -F<feature.h>) is no longer used throughout the codebase, but more specific -macros, e.g., C<FEATURE_SAY_IS_ENABLED>, that are defined in F<feature.h>. +=item * + +Some global variables have been marked C<const>, members in the interpreter +structure have been re-ordered, and the opcodes have been re-ordered. The op +C<OP_AELEMFAST> has been split into C<OP_AELEMFAST> and C<OP_AELEMFAST_LEX>. =item * -F<lib/feature.pm> is now a generated file, created by the new -F<regen/feature.pl> script, which also generates F<feature.h>. +When empting a hash of its elements (e.g. via undef(%h), or %h=()), HvARRAY +field is no longer temporarily zeroed. Any destructors called on the freed +elements see the remaining elements. Thus, %h=() becomes more like C<delete +$h{$_} for keys %h>. =item * -Tied arrays are now always C<AvREAL>. If C<@_> or C<DB::args> is tied, it -is reified first, to make sure this is always the case. +Boyer-Moore compiled scalars are now PVMGs, and the Boyer-Moore tables are now +stored via the mg_ptr of their C<PERL_MAGIC_bm>. Previously they were PVGVs, +with the tables stored in the string buffer, beyond C<SvLEN()>. This eliminates +the last place where the core stores data beyond C<SvLEN()>. + +=item * + +Simplified logic in C<Perl_sv_magic()> introduces a small change of +behaviour for error cases involving unknown magic types. Previously, if +C<Perl_sv_magic()> was passed a magic type unknown to it, it would + +=over + +=item 1. + +Croak "Modification of a read-only value attempted" if read only + +=item 2. + +Return without error if the SV happened to already have this magic + +=item 3. + +otherwise croak "Don't know how to handle magic of type \\%o" + +=back + +Now it will always croak "Don't know how to handle magic of type \\%o", even +on read only values, or SVs which already have the unknown magic type. + +=item * + +The experimental C<fetch_cop_label> function has been renamed to +C<cop_fetch_label>. + +=item * + +The C<cop_store_label> function has been added to the API, but is +experimental. + +=item * + +F<embedvar.h> has been simplified, and one level of macro indirection for +PL_* variables has been removed for the default (non-multiplicity) +configuration. PERLVAR*() macros now directly expand their arguments to +tokens such as C<PL_defgv>, instead of expanding to C<PL_Idefgv>, with +F<embedvar.h> defining a macro to map C<PL_Idefgv> to C<PL_defgv>. XS code +which has unwarranted chumminess with the implementation may need updating. + +=item * + +A C<coreargs> opcode has been added, to be used by C<&CORE::foo> subs to sort +out C<@_>. + +=item * + +An API has been added to explicitly choose whether or not to export XSUB +symbols. More detail can be found in the comments for commit e64345f8. =item * @@ -1754,6 +1813,125 @@ F<pad.c> has done its custom freeing of the pads). All the C files that make up the Perl core have been converted to UTF-8. +=item * + +These new functions have been added as part of the work on Unicode symbols: + + HvNAMELEN + HvNAMEUTF8 + HvENAMELEN + HvENAMEUTF8 + gv_init_pv + gv_init_pvn + gv_init_pvsv + gv_fetchmeth_pv + gv_fetchmeth_pvn + gv_fetchmeth_sv + gv_fetchmeth_pv_autoload + gv_fetchmeth_pvn_autoload + gv_fetchmeth_sv_autoload + gv_fetchmethod_pv_flags + gv_fetchmethod_pvn_flags + gv_fetchmethod_sv_flags + gv_autoload_pv + gv_autoload_pvn + gv_autoload_sv + newGVgen_flags + sv_derived_from_pv + sv_derived_from_pvn + sv_derived_from_sv + sv_does_pv + sv_does_pvn + sv_does_sv + whichsig_pv + whichsig_pvn + whichsig_sv + newCONSTSUB_flags + +The gv_fetchmethod_*_flags functions, like gv_fetchmethod_flags, are +experimental and may change in a future release. + +=item * + +The following functions were added. These are I<not> part of the API: + + GvNAMEUTF8 + GvENAMELEN + GvENAME_HEK + CopSTASH_flags + CopSTASH_flags_set + PmopSTASH_flags + PmopSTASH_flags_set + sv_sethek + HEKfARG + +There is also a C<HEKf> macro corresponding to C<SVf>, for +interpolating HEKs in formatted strings. + +=item * + +C<sv_catpvn_flags> takes a couple of new internal-only flags, +C<SV_CATBYTES> and C<SV_CATUTF8>, which tell it whether the char array to +be concatenated is UTF8. This allows for more efficient concatenation than +creating temporary SVs to pass to C<sv_catsv>. + +=item * + +For XS AUTOLOAD subs, $AUTOLOAD is set once more, as it was in 5.6.0. This +is in addition to setting C<SvPVX(cv)>, for compatibility with 5.8 to 5.14. +See L<perlguts/Autoloading with XSUBs>. + +=item * + +Perl now checks whether the array (the linearised isa) returned by a MRO +plugin begins with the name of the class itself, for which the array was +created, instead of assuming that it does. This prevents the first element +from being skipped during method lookup. It also means that +C<mro::get_linear_isa> may return an array with one more element than the +MRO plugin provided [perl #94306]. + +=item * + +C<PL_curstash> is now reference-counted. + +=item * + +There are now feature bundle hints in C<PL_hints> (C<$^H>) that version +declarations use, to avoid having to load F<feature.pm>. One setting of +the hint bits indicates a "custom" feature bundle, which means that the +entries in C<%^H> still apply. F<feature.pm> uses that. + +The C<HINT_FEATURE_MASK> macro is defined in F<perl.h> along with other +hints. Other macros for setting and testing features and bundles are in +the new F<feature.h>. C<FEATURE_IS_ENABLED> (which has moved to +F<feature.h>) is no longer used throughout the codebase, but more specific +macros, e.g., C<FEATURE_SAY_IS_ENABLED>, that are defined in F<feature.h>. + +=item * + +F<lib/feature.pm> is now a generated file, created by the new +F<regen/feature.pl> script, which also generates F<feature.h>. + +=item * + +Tied arrays are now always C<AvREAL>. If C<@_> or C<DB::args> is tied, it +is reified first, to make sure this is always the case. + +=item * + +Two new functions C<utf8_to_uvchr_buf()> and C<utf8_to_uvuni_buf()> have +been added. These are the same as C<utf8_to_uvchr> and +C<utf8_to_uvuni> (which are now deprecated), but take an extra parameter +that is used to guard against reading beyond the end of the input +string. +See L<perlapi/utf8_to_uvchr_buf> and L<perlapi/utf8_to_uvuni_buf>. + +=item * + +The regular expression engine now does TRIE case insensitive matches +under Unicode. This may change the output of C<< use re 'debug'; >>, +and will speed up various things. + =back =head1 Selected Bug Fixes |