In perl.git, the branch perldelta has been updated
<http://perl5.git.perl.org/perl.git/commitdiff/7a71bf978ccb0dbe08566e0941e6e371c003bfbf?hp=952551ff6e2b4d1694aa35b07988da9ce1386236>
- Log -----------------------------------------------------------------
commit 7a71bf978ccb0dbe08566e0941e6e371c003bfbf
Author: Ricardo Signes <r...@cpan.org>
Date: Thu Mar 10 20:03:27 2016 -0500
perldelta: merge in changes from perl5235delta
M Porting/perl5240delta.pod
commit 6cca8214d0c106651fc0864806237323c18e22d3
Author: Ricardo Signes <r...@cpan.org>
Date: Thu Mar 10 19:50:06 2016 -0500
perldelta: merge in changes from perl5234delta
M Porting/perl5240delta.pod
-----------------------------------------------------------------------
Summary of changes:
Porting/perl5240delta.pod | 391 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 391 insertions(+)
diff --git a/Porting/perl5240delta.pod b/Porting/perl5240delta.pod
index 712c2d4..b432688 100644
--- a/Porting/perl5240delta.pod
+++ b/Porting/perl5240delta.pod
@@ -129,6 +129,23 @@ C<$Carp::MaxArgNums> is supposed to be the number of
arguments to display.
Prior to this version, it was instead showing C<$Carp::MaxArgNums> + 1
arguments,
contrary to the documentation.
+=head2 Lexical $_ has been removed
+
+C<my $_> was introduced in Perl 5.10, and subsequently caused much confusion
+with no obvious solution. In Perl 5.18.0, it was made experimental on the
+theory that it would either be removed or redesigned in a less confusing (but
+backward-incompatible) way. Over the following years, no alternatives were
+proposed. The feature has now been removed and will fail to compile.
+
+=head2 Only blanks and tabs are now allowed within C<[...]> within C<(?[...])>.
+
+The experimental Extended Bracketed Character Classes can contain regular
+bracketed character classes within them. These differ from regular ones in
+that white space is generally ignored, unless escaped by preceding it with a
+backslash. The white space that is ignored is now limited to just tab C<\t>
+and SPACE characters. Previously, it was any white space. See
+L<perlrecharclass/Extended Bracketed Character Classes>.
+
=head1 Deprecations
=head2 sysread(), syswrite(), recv() and send() are deprecated on
@@ -174,6 +191,39 @@ Single arguments in list assign are now slightly faster:
($x) = (...);
(...) = ($x);
+=item *
+
+C</fixed-substr/> has been made much faster.
+
+On platforms with a libc memchr() implementation which makes good use of
+underlying hardware support, patterns which include fixed substrings will now
+often be much faster; for example with glibc on a recent x86_64 CPU, this:
+
+ $s = "a" x 1000 . "wxyz";
+ $s =~ /wxyz/ for 1..30000
+
+is now about 7 times faster. On systems with slow memchr(), e.g. 32-bit ARM
+Raspberry Pi, there will be a small or little speedup. Conversely, some
+pathological cases, such as C<"ab" x 1000 =~ /aa/> will be slower now; up to 3
+times slower on the rPi, 1.5x slower on x86_64.
+
+=item *
+
+Faster addition, subtraction and multiplication.
+
+Since 5.8.0, arithmetic became slower due to the need to support
+64-bit integers. To deal with 64-bit integers, a lot more corner
+cases need to be checked, which adds time. We now detect common
+cases where there is no need to check for those corner cases,
+and special-case them.
+
+=item *
+
+Faster preincrement, predecrement, postincrement, postdecrement.
+
+By internally splitting the functions which handled multiple
+cases into different functions.
+
=back
=head1 Modules and Pragmata
@@ -323,6 +373,50 @@ exports anything. [perl #125410]
=head2 Changes to Existing Documentation
+=head3 L<perlapi>
+
+=over 4
+
+=item *
+
+The process of using undocumented globals has been documented, namely, that one
+should send email to L<perl5-port...@perl.org|mailto:perl5-port...@perl.org>
+first to get the go-ahead for documenting and using an undocumented function or
+global variable.
+
+=back
+
+=head3 L<perlsub>
+
+=over 4
+
+=item *
+
+Updated to note that anonymous subroutines can have signatures.
+
+=back
+
+=head3 L<perltie>
+
+=over 4
+
+=item *
+
+The usage of C<FIRSTKEY> and C<NEXTKEY> has been clarified.
+
+=back
+
+=head3 L<perlvar>
+
+=over 4
+
+=item *
+
+The specific true value of C<$!{E...}> is now documented, noting that it is
+subject to change and not guaranteed.
+
+=back
+
=head3 L<perlcall>
=over 4
@@ -417,11 +511,27 @@ sense.
=item *
+L<Can't find Unicode property definition "%s" in regex;|perldiag/"Can't find
Unicode property definition "%s" in regex; marked by <-- HERE in m/%s/">
+
+=item *
+
L<Can't redeclare "%s" in "%s"|perldiag/"Can't redeclare "%s" in "%s"">
(F) A "my", "our" or "state" declaration was found within another declaration,
such as C<my ($x, my($y), $z)> or C<our (my $x)>.
+=item *
+
+L<Character following \p must be '{' or a single-character Unicode property
name in regex;|perldiag/"Character following \%c must be '{' or a
single-character Unicode property name in regex; marked b ... [21 chars
truncated]
+
+=item *
+
+L<Illegal user-defined property name|perldiag/"Illegal user-defined property
name">
+
+=item *
+
+L<<< Sequence (?... not terminated in regex; marked by S<<-- HERE> in
mE<sol>%sE<sol>|perldiag/"Sequence (?... not terminated in regex; marked by <--
HERE in mE<sol>%sE<sol>" >>>
+
=back
=head3 New Warnings
@@ -462,6 +572,21 @@ are called on handle with the C<:utf8> layer.
The diagnostic C<< Hexadecimal float: internal error >> has been changed to
C<< Hexadecimal float: internal error (%s) >> to include more information.
+=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.
+
+=item *
+
+When running out of memory during an attempt the increase the stack
+size, previously, perl would die using the cryptic message
+C<< panic: av_extend_guts() negative count (-9223372036854775681) >>.
+This has been fixed to show the prettier message:
+L<< Out of memory during stack extend|perldiag/"Out of memory during %s
extend" >>
+
=back
=head1 Configuration and Compilation
@@ -470,6 +595,44 @@ C<< Hexadecimal float: internal error (%s) >> to include
more information.
=item *
+C<Configure> now acts as if the C<-O> option is always passed, allowing command
+line options to override saved configuration. This should eliminate confusion
+when command line options are ignored for no obvious reason. C<-O> is now
+permitted, but ignored.
+
+=item *
+
+Some filesystem stat symbols which were not used by the Perl core
+were removed in an earlier commit. However, since these symbols
+turned out to be used by at least one CPAN module, these symbols
+have been restored.
+
+=item *
+
+C<< PPPort.so/PPPort.dll >> no longer get installed, as they are
+not used by C<< PPPort.pm >>, only by its test files.
+
+=item *
+
+It is now possible to specify which compilation date to show on
+C<< perl -V >> output, by setting the macro C<< PERL_BUILD_DATE >>.
+
+
+=item *
+
+Using the C<NO_HASH_SEED> define in combination with the default hash algorithm
+C<PERL_HASH_FUNC_ONE_AT_A_TIME_HARD> resulted in a fatal error while compiling
+the interpreter, since Perl 5.17.10. This has been fixed.
+
+=item *
+
+If you had F<Configure> hints for C<d_procselfexe> or C<procselfexe>, they were
+probably broken by the AmigaOS changes in Perl 5.23.3. This has been now
+fixed.
+L<[perl #126152]|https://rt.perl.org/Ticket/Display.html?id=126152>
+
+=item *
+
F<Configure> should handle spaces in paths a little better.
=back
@@ -496,6 +659,111 @@ Win32 compilers are supported.
=over 4
+=item IRIX
+
+=over
+
+=item *
+
+Under some circumstances IRIX stdio fgetc() and fread() set the errno to
+C<ENOENT>, which made no sense according to either IRIX or POSIX docs. Errno
+is now cleared in such cases.
+L<[perl #123977]|https://rt.perl.org/Ticket/Display.html?id=123977>
+
+=item *
+
+Problems when multiplying long doubles by infinity have been fixed.
+L<[perl #126396]|https://rt.perl.org/Ticket/Display.html?id=126396>
+
+=back
+
+=item MacOS X
+
+=over
+
+=item *
+
+Until now OS X builds of perl have specified a link target of 10.3 (Panther,
+2003) but have not specified a compiler target. From now on, builds of perl on
+OS X 10.6 or later (Snow Leopard, 2008) by default capture the current OS X
+version and specify that as the explicit build target in both compiler and
+linker flags, thus preserving binary compatibility for extensions built later
+regardless of changes in OS X, SDK, or compiler and linker versions. To
+override the default value used in the build and preserved in the flags,
+specify C<export MACOSX_DEPLOYMENT_TARGET=10.N> before configuring and building
+perl, where 10.N is the version of OS X you wish to target. In OS X 10.5 or
+earlier there is no change to the behavior present when those systems were
+current; the link target is still OS X 10.3 and there is no explicit compiler
+target.
+
+=back
+
+=item Tru64
+
+Workaround where Tru64 balks when prototypes are listed as
+C<< PERL_STATIC_INLINE >>, but where the test is build with
+C<< -DPERL_NO_INLINE_FUNCTIONS >>.
+
+=item VMS
+
+=over
+
+=item *
+
+Perl now implements its own C<killpg> by scanning for processes in the
+specified process group, which may not mean exactly the same thing as a Unix
+process group, but allows us to send a signal to a parent (or master) process
+and all of its sub-processes. At the perl level, this means we can now send a
+negative pid like so:
+
+ kill SIGKILL, -$pid;
+
+to signal all processes in the same group as C<$pid>.
+
+=back
+
+=item Win32
+
+=over
+
+=item *
+
+A new build option C<USE_NO_REGISTRY> has been added to the makefiles. This
+option is off by default, meaning the default is to do Windows registry
+lookups. This option stops Perl from looking inside the registry for anything.
+For what values are looked up in the registry see L<perlwin32>. Internally, in
+C, the name of this option is C<WIN32_NO_REGISTRY>.
+
+=item *
+
+The behavior of Perl using C<HKEY_CURRENT_USER\Software\Perl> and
+C<HKEY_LOCAL_MACHINE\Software\Perl> to lookup certain values, including C<%ENV>
+vars starting with C<PERL> has changed. Previously, the 2 keys were checked
+for entries at all times through Perl processes life time even if they did not
+exist. For performance reasons, now, if the root key (i.e.
+C<HKEY_CURRENT_USER\Software\Perl> or C<HKEY_LOCAL_MACHINE\Software\Perl>) does
+not exist at process start time, it will not be checked again for C<%ENV>
+override entries for the remainder of the Perl processes life. This more
+closely matches Unix behaviour in that the environment is copied or inherited
+on startup and changing the variable in the parent process or another process
+or editing F<.bashrc> will not change the environmental variable in other
+existing, running, processes.
+
+=item *
+
+One glob fetch was removed for each C<-X> or C<stat> call whether done from
+Perl code or internally from Perl's C code. The glob being looked up was
+C<${^WIN32_SLOPPY_STAT}> which is a special variable. This makes C<-X> and
+C<stat> slightly faster.
+
+=item *
+
+During miniperl's process startup, during the build process, 4 to 8 IO calls
+related to the process starting F<.pl> and the F<buildcustomize.pl> file were
+removed from the code opening and executing the first 1 or 2 F<.pl> files.
+
+=back
+
=item EBCDIC
=over 4
@@ -569,6 +837,28 @@ Perl 5.22.1.
=item *
+C<< sv_ref() >> is now part of the API.
+
+=item *
+
+L<perlapi/sv_backoff> had its return type changed from C<int> to C<void>. It
+previously has always returned C<0> since Perl 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)>.
+
+=item *
+
+The C<EXTEND> and C<MEXTEND> macros have been improved to avoid various issues
+with integer truncation and wrapping. In particular, some casts formerly used
+within the macros have been removed. This means for example that passing an
+unsigned nitems argument is likely to raise a compiler warning now (it's always
+been documented to require a signed value; formerly int, lately SSize_t).
+
+=item *
+
C<PL_sawalias> and C<GPf_ALIASED_SV> have been removed.
=item *
@@ -583,6 +873,107 @@ C<GvASSIGN_GENERATION> and C<GvASSIGN_GENERATION_set>
have been removed.
=item *
+C<\b{sb}> works much better. In Perl v5.22.0, this new construct didn't
+seem to give the expected results, yet passed all the tests in the
+extensive suite furnished by Unicode. It turns out that it was because
+these were short input strings, and the failures had to do with longer
+inputs. This was fixed in Perl 5.23.4, but the improvement was not
+noticed until after that was released, so is included here now.
+
+=item *
+
+Certain syntax errors in
+L<perlrecharclass/Extended Bracketed Character Classes> caused panics
+instead of the proper error message. This has now been fixed. [perl
+#126481]
+
+=item *
+
+An earlier commit added a message when a quantifier in a regular
+expression was useless, but then caused the parser to skip it;
+this caused the surplus quantifier to be silently ignored, instead
+of throwing an error. This is now fixed. [perl #126253]
+
+=item *
+
+The switch to building non-XS modules last in win32/makefile.mk (introduced
+by design as part of the changes to enable parallel building) caused the
+build of POSIX to break due to problems with the version module. This
+is now fixed.
+
+=item *
+
+Improved parsing of hex float constants.
+
+=item *
+
+Fixed an issue with C<< pack >> where C<< pack "H" >> (and C<< pack "h" >>)
+could read past the source when given a non-utf8 source, and a utf8 target.
+[perl #126325]
+
+=item *
+
+Fixed several cases where perl would abort due to a segmentation fault,
+or a C-level assert. [perl #126615], [perl #126602], [perl #126193].
+
+=item *
+
+There were places in regular expression patterns where comments (C<(?#...)>)
+weren't allowed, but should have been. This is now fixed.
+L<[perl #116639]|https://rt.perl.org/Ticket/Display.html?id=116639>
+
+=item *
+
+Some regressions from Perl 5.20 have been fixed, in which some syntax errors in
+L<C<(?[...])>|perlrecharclass/Extended Bracketed Character Classes> constructs
+within regular expression patterns could cause a segfault instead of a proper
+error message.
+L<[perl #126180]|https://rt.perl.org/Ticket/Display.html?id=126180>
+L<[perl #126404]|https://rt.perl.org/Ticket/Display.html?id=126404>
+
+=item *
+
+Another problem with
+L<C<(?[...])>|perlrecharclass/Extended Bracketed Character Classes>
+constructs has been fixed wherein things like C<\c]> could cause panics.
+L<[perl #126181]|https://rt.perl.org/Ticket/Display.html?id=126181>
+
+=item *
+
+Some problems with attempting to extend the perl stack to around 2G or 4G
+entries have been fixed. This was particularly an issue on 32-bit perls built
+to use 64-bit integers, and was easily noticeable with the list repetition
+operator, e.g.
+
+ @a = (1) x $big_number
+
+Formerly perl may have crashed, depending on the exact value of C<$big_number>;
+now it will typically raise an exception.
+L<[perl #125937]|https://rt.perl.org/Ticket/Display.html?id=125937>
+
+=item *
+
+In a regex conditional expression C<(?(condition)yes-pattern|no-pattern)>, if
+the condition is C<(?!)> then perl failed the match outright instead of
+matching the no-pattern. This has been fixed.
+L<[perl #126222]|https://rt.perl.org/Ticket/Display.html?id=126222>
+
+=item *
+
+The special backtracking control verbs C<(*VERB:ARG)> now all allow an optional
+argument and set C<REGERROR>/C<REGMARK> appropriately as well.
+L<[perl #126186]|https://rt.perl.org/Ticket/Display.html?id=126186>
+
+=item *
+
+Several bugs, including a segmentation fault, have been fixed with the bounds
+checking constructs (introduced in Perl 5.22) C<\b{gcb}>, C<\b{sb}>, C<\b{wb}>,
+C<\B{gcb}>, C<\B{sb}>, and C<\B{wb}>. All the C<\B{}> ones now match an empty
+string; none of the C<\b{}> ones do.
+L<[perl #126319]|https://rt.perl.org/Ticket/Display.html?id=126319>
+
+=item *
+
Duplicating a closed file handle for write no longer creates a
filename of the form F<GLOB(0xXXXXXXXX)>. [perl #125115]
--
Perl5 Master Repository
