perlcdelta.pod

=encoding utf8

=head1 NAME

perlcdelta - what is new for cperl v5.30.0

=head1 DESCRIPTION

This document describes differences between the cperl 5.28.2 and the cperl
5.30.0 release.

If you are upgrading from an earlier release such as v5.26.2c, first
read L<perl5280cdelta>, which describes the differences between
v5.28.0c and v5.26.2c.

=head1 Core Enhancements

=head2 Check bless name under use strict names

The second argument to bless, the new classname, is now checked to be a
valid package name identifier when B<strict 'names'> is in effect, and the
name is now normalized.
L<[cperl #376]|https://github.com/perl11/cperl/issues/376>

This is a bugfix, but a major compatibility change.

=head2 New warning shadow package

When a subroutine with the same name of a package exists, all package
methods are rerouted through this subroutine, effectively
eliminating all access to the package via methods.  This is almost
always an error, unless you want to override access to the package
or want a data-only package, without any methods.
cperl added the shadow warnings
L<perldiag/"Subroutine &%s::%s masks existing package %s">,
L<perldiag/"Subroutine &%s masks new package %s"> and
L<perldiag/"Subroutine &%s masks new class %s">.
Use C<no warnings 'shadow';> to silence these new warnings.

=head2 extern sub - libffi

A new L<ffi> was added to core, with a syntax resembling perl6
NativeCall.  Perl6 traits are cperl L<attributes>, but attribute
values may be deferred to run-time. Packagers need to add B<libffi> to
their library dependencies. Windows packages are provided,
see F<appveyor.yml>.

Not yet implemented are the C<:encoded()> attribute for string
arguments and return values, the various encoded string types Uni,
wchar, c-struct helpers, native arrays and native classes
(i.e. structs), callback helpers and support for variadic (varargs)
functions.

=head2 Signature args are run-time type checked

Run-time type violations a throw a new type warning, which can be made fatal
with C<use types 'strict'> or C<< use warnings 'FATAL' => 'types'; >>
L<perldiag/"Type of arg %s to %s should be %s (not %s)">.
The compile-time error uses the word "must" instead of "should".
This might be a problem when typing an argument to C<str> or C<Str>,
but the argument is stringified via overload from a class,
e.g. File::Temp::Dir. This case, when the argument is not of str|Str,
but a user-defined class with a stringify overload is not yet handled.

L<[cperl #389]|https://github.com/perl11/cperl/issues/389> and
L<[cperl #387]|https://github.com/perl11/cperl/issues/387>.
cperl-only

=head2 Better role composition

When roles are copied from a class to another, we can now handle XS
methods and methods without internal lexical variables better, by
simple GV aliasing.

The other methods are now properly cloned and the C<$self> type is
adjusted to the new class for the created new method, because v5.30
started argument type checking at run-time.

cperl can also now adjust field indices when composing roles, when
the indices of the used lexical variables of the two methods do not
match, by using the new internal experimental B<inliner>.
L<[cperl #311]|https://github.com/perl11/cperl/issues/311>
The error "panic: cannot yet adjust field indices when composing role
%s::%s into %s %s [cperl #311]" is gone in the general case.

=head2 Wildcards in Unicode property value specifications are now
partially supported

You can now do something like this in a regular expression pattern

 qr! \p{nv= /(?x) \A [0-5] \z / }!

which matches all Unicode code points which have numeric value is
between 0 and 5 inclusive.

This marks another step in implementing the regular expression features
the Unicode Consortium suggests.

Most properties are supported, with the remainder planned for 5.32.
Details are in L<perlunicode/Wildcards in Property Values>.

=head2 qr'\N{name}' is now supported

Previously it was an error to evaluate a named character C<\N{...}>
within a single quoted regular expression pattern (whose evaluation is
deferred from the normal place).  This restriction is now removed.

=head2 Unicode 12.1 is supported

For details, see L<https://www.unicode.org/versions/Unicode12.1.0/>.

The Word_Break property, as in past Perl releases, remains tailored to
behave more in line with expectations of Perl users.  This means that
sequential runs of horizontal white space characters are not broken
apart, but kept as a single run.  Unicode 11 changed from past versions
to be more in line with Perl, but it left several white space characters
as causing breaks: TAB, NO BREAK SPACE, and FIGURE SPACE (U+2007).  We
have decided to continue to use the previous Perl tailoring with regards
to these.

As of July 2018, another aspect of Unicode 11.0 is causing problems,
and that is the changing the Georgian script to have both lower and
uppercase letters.  It turns out that many devices do not have fonts
installed that can display the new uppercase letters, and people using
Georgian are finding their text more or less illegible.  It is being
suggested that implementations delay their adoption of this portion of
11.0. But since the next stable release of Perl is almost a year away,
this aspect of 11.0 is being left in, with the option to back it out
if things haven't improved by that time, or if we get too many
complaints about the development release being unusable for Georgian
users.

Because of a change in Unicode release cycles, Perl jumps from Unicode
10.0 in Perl 5.28 to Unicode 12.0 in Perl 5.30.

There are few new scripts: Elymaic, Nandinagari,
Nyiakeng_Puachue_Hmong (Hmnp), Wancho, all of them not available
for identifiers.

=head2 Handle qr!\p{nv=6/8}!

Allow a rational number specified in looking up the Numeric
Value Unicode property to not be in lowest possible terms.

The Numeric Value property allows one to find all code points that have
a certain numeric value.  An example would be to match against any
character in any of the world's scripts which is effectively equivalent
to the digit zero.

We accept either integers (like C<\p{nv=9}>) or rationals (like C<\p{nv=1/2}>).
But we also accept floating point representations in case a conversion to numeric
has happened, (like C<\p{nv=0.5}>).
The necessary precision is now automatically pre-calculated and the lookup
normalized.

=head2 The upper limit C<"n"> specifiable in a regular expression
quantifier of the form C<"{m,n}"> has been doubled to 65534

The upper limit C<"n"> specifiable in a regular expression
quantifier of the form C<"{m,n}"> has also been doubled to 65534.

The meaning of an unbounded upper quantifier C<"{m,}"> remains unchanged.
It matches 2**31 - 1 times on most platforms, and more on ones where a C
language short variable is more than 4 bytes long.

=head2 C<-Drv> now means something on C<-DDEBUGGING> builds

Now, adding the verbose flag (C<-Dv>) to the C<-Dr> flag turns on all
possible regular expression debugging, as with C<use re 'debug';>. See L<re>.

=head2 Eliminated optree recursion

Eliminated recursion from internal C<finalize_op()> and C<optimize_op()>,
avoiding segfaults with extremely nested ops.
E.g. with

    perl -e 'my $line = "\$cond ? \$a : \n";
             my $code = ($line x 100000) . "\$b;\n";
             eval $code;'

Contrary to what is said in the relevant perldelta,
your code is now slower.
Before it crashed with a segfault, now it does much more.
The regular case is also slower due to stack handling on the heap,
similar to the regexp changes in 5.10.
L<[perl #108276]|https://rt.perl.org/Ticket/Display.html?id=108276>.

=head2 Turkic UTF-8 locales are now seamlessly supported

Turkic languages have different casing rules than other languages for
the characters C<"i"> and C<"I">.  The uppercase of C<"i"> is LATIN
CAPITAL LETTER I WITH DOT ABOVE (U+0130); and the lowercase of C<"I"> is LATIN
SMALL LETTER DOTLESS I (U+0131).  Unicode furnishes alternate casing
rules for use with Turkic languages.  Previously, Perl ignored these,
but now, it uses them when it detects that it is operating under a
Turkic UTF-8 locale.

=head2 It is now possible to compile perl to always use thread-safe
locale operations.

Previously, these calls were only used when the perl was compiled to be
multi-threaded.  To always enable them, add

  -Accflags='-DUSE_THREAD_SAFE_LOCALE'

to your F<Configure> flags.

=head2 Check RUNNING_ON_VALGRIND, set destruct_level to 2

Detect if we are running under valgrind and set destruct_level to 2.
If so, destruct all ops, leading to no valgrind leaks, even with
--leak-check=full.
cperl-only L<[cperl #400]|https://github.com/perl11/cperl/issues/400>

=head1 Security

=head2 Variable length lookbehind in regular expression pattern matching
is now experimentally supported

Using a lookbehind assertion (like C<(?<=foo)> or C<(?<!bar)> previously
would generate an error and refuse to compile.  Now it compiles (if the
maximum lookbehind is at most 255 characters), but raises a warning in
the new C<experimental::vlb> warnings category.  This is to caution you
that the precise behavior is subject to change based on feedback from
use in the field.

See L<perlre/(?<=pattern)> and L<perlre/(?<!pattern)>.

=head2 Disallowed Limited Use Scripts

The list of valid scripts for identifiers was purged from all
B<Limited Use> scripts from
L<http://www.unicode.org/reports/tr31/#Table_Limited_Use_Scripts>.
They fail now.

Unicode 10.0 started disallowing all Aspirational Use Scripts, but
we didn't handle them at all.
I<Table 4. Candidate Characters for Exclusion from Identifiers> scripts
are still allowed, and still need to be explicitly enabled as a C<use utf8>
argument.
cperl-only.

=head2 [CVE-2018-18311] Integer overflow leading to buffer overflow and segmentation fault

Integer arithmetic in C<Perl_my_setenv()> could wrap when the combined length
of the environment variable name and value exceeded around 0x7fffffff.  This
could lead to writing beyond the end of an allocated buffer with attacker
supplied data.

L<[perl #133204]|https://rt.perl.org/Ticket/Display.html?id=133204>

=head2 Restrict my_setenv to ARG_MAX

perl5 fixed C<Perl_my_setenv()> by allowing C<%ENV> sizes larger than
C<ARG_MAX> (typically 128Kb), up to 2GB. This is considered a security
risk. It writes onto the kernel stack, even if often caught by MAXEXECARGS
"Argument list too long" kernel errors on the next exec call.
cperl disallows C<%ENV> larger than the sysconf(_SC_ARG_MAX)/MAX_ARG_STRLEN/
ARG_MAX/NCARGS size with a new L<perldiag/"Environment size %d larger than the allowed %d">
error.

=head1 Incompatible Changes

=head2 Protected hash iterators

Iterating over a hash may now by default not change any key. Allow the
previous destructive behavior of changing a hash while iterating over
it with C<use hashiter;>
See L<[cperl #117]|https://github.com/perl11/cperl/issues/117>, cperl-only.

=head2 Assigning non-zero to C<$[> is fatal

Setting L<< C<$[>|perlvar/$[ >> to a non-zero value has been deprecated since
Perl 5.12 and now throws a fatal error.
See L<<< perldeprecation/Assigning non-zero to C<< $[ >> is fatal >>>.

=head2 Previously deprecated sysread()/syswrite() on :utf8 handles now fatal

Calling sysread(), syswrite(), send() or recv() on a C<:utf8> handle,
whether applied explicitly or implicitly, is now fatal.  This was
deprecated in perl 5.24.

There were two problems with calling these functions on C<:utf8>
handles:

=over

=item *

All four functions only paid attention to the C<:utf8> flag.  Other
layers were completely ignored, so a handle with
C<:encoding(UTF-16LE)> layer would be treated as UTF-8.  Other layers,
such as compression are completely ignored with or without the
C<:utf8> flag.

=item *

sysread() and recv() would read from the handle, skipping any
validation by the layers, and do no validation of their own.  This
could lead to invalidly encoded perl scalars.

=back

L<[perl #125760]|https://rt.perl.org/Public/Bug/Display.html?id=125760>

=head2 my() in false conditional prohibited

Declarations such as C<my $x if 0> are no longer permitted.
This feature was deprecated in 5.10 (and replaced by two better constructs,
one of it backwards compatible) and is now a fatal error.
L<[perl #133543]|https://rt.perl.org/Public/Bug/Display.html?id=133543>

Note: cperl does not agree that this feature is a bug, but this ship
sailed already over a decade ago.

=head2 Fatalize $* and $#

These special variables, long deprecated, now throw an error when used.
See L<perldiag/"$* is no longer supported as of Perl 5.30"> and
L<perldiag/"$# is no longer supported as of Perl 5.30">.
L<[perl #133583]|https://rt.perl.org/Public/Bug/Display.html?id=133583>

=head2 Fatalize unqualified use of dump()

The C<dump()> function, long discouraged, may no longer be used unless it is
fully qualified, I<i.e.>, C<CORE::dump()>.

L<[perl #133584]|https://rt.perl.org/Public/Bug/Display.html?id=133584>

=head2 Remove File::Glob::glob()

The C<File::Glob::glob()> function, long deprecated, has been removed and now
throws an exception which advises use of C<File::Glob::bsd_glob()> instead.

L<[perl #133586]|https://rt.perl.org/Public/Bug/Display.html?id=133586>

=head2 C<pack()> no longer can return malformed UTF-8

It croaks if it would otherwise return a UTF-8 string that contains
malformed UTF-8.  This protects agains potential security threats.  This
is considered a bug fix as well.

L<[perl #131642]|https://rt.perl.org/Public/Bug/Display.html?id=131642>

=head2 Any set of digits in the Common script are legal in a script run
of another script

There are several sets of digits in the Common script.  C<[0-9]> is the
most familiar.  But there are also C<[\x{FF10}-\x{FF19}]> (FULLWIDTH
DIGIT ZERO - FULLWIDTH DIGIT NINE), and several sets for use in
mathematical notation, such as the MATHEMATICAL DOUBLE-STRUCK DIGITs.
Any of these sets should be able to appear in script runs of, say,
Greek.  But the design of 5.30 overlooked all but the ASCII digits
C<[0-9]>, so the design was flawed.  This has been fixed, so is both a
bug fix and an incompatibility. [perl #133547]
L<[perl #133547]|https://rt.perl.org/Public/Bug/Display.html?id=133547>

All digits in a run still have to come from the same set of ten digits.

=head1 Deprecations

=head2 Undeprecate "Unescaped left brace in regex" warnings and errors

In cperl only the following special unicode groups within regexes are reserved:

   Name:     \N{
   Property: \p{ \P{
   Break:    \b{ \B{
   Code:     \x{ \o{
   Group:    \g{

All other C</{}/> sequences are allowed in cperl and not deprecated
anymore. There's no need to quote the literal C<\{> and C<\}>, only if
it's ambiguous and can be mixed up with those reserved unicode groups.

B<automake> and more widespread utils does not need to be plagued by
spurious "Unescaped left brace in regex" warnings, when they dont need
to be quoted.  We undeprecated those new warnings and errors, there's
nothing more to reserve (yet).
L<[cperl #362]|https://github.com/perl11/cperl/issues/362>

=head2 Remove support for C<qr/\p{_Case_Ignorable}>

This property is no longer used in the core, nor in cpan, and is marked
as for core use only, not necessarily stable.  I have kept it around
because it was work to remove it, but now the revamping of the property
lookup scheme was causing failures with it, when compiling on early
Unicode releases.  That could be fixed with extra work, but simply
removing it also fixes the problem and avoids future maintenance
costs.

=head2 Remove support for C<qr/\p{_Comb_Above}>

This property is no longer used in the core, nor in cpan, and is marked
as for core use only, not necessarily stable.  I have kept it around
because it was work to remove it, but now the revamping of the property
lookup scheme was causing failures with a similar property, and the
previous commit removed that one.

=head2 Remove support for C<qr/\p{_CanonDCIJ}>

The property is not used in cpan, and is being removed as part of the cleanup
instigated because another of the 3 would
require extra code to handle if we were to keep it around.

=head1 Performance Enhancements

=over 4

=item *

Optimization of C<IV> to C<UV> conversions.
L<[perl #133677]|https://rt.perl.org/Ticket/Display.html?id=133677>.

=item *

Speed up of the integer stringification algorithm by processing
two digits at a time instead of one.
L<[perl #133691]|https://rt.perl.org/Ticket/Display.html?id=133691>.

=item *

Minor improvements based on LGTM analysis and recommendation.
(L<https://lgtm.com/projects/g/Perl/perl5/alerts/?mode=tree>).
L<[perl #133686]|https://rt.perl.org/Ticket/Display.html?id=133686>.
L<[perl #133699]|https://rt.perl.org/Ticket/Display.html?id=133699>.

=item *

Improved Unicode numeric property lookups, for C<\p{nv=float}>,
in size and speed by using more pre-compiled perfect hashes instead
of slow pure-perl invlist walks at run-time, esp. for all numeric
properties (70 more).
Also avoids more swash creations.

=item *

Translating from UTF-8 into the code point it represents now is done via a
deterministic finite automaton, speeding it up.  As a typical example,
C<ord("\x7fff")> now requires 12% fewer instructions than before.  The
performance of checking that a sequence of bytes is valid UTF-8 is similarly
improved, again by using a dfa.

=item *

Code optimizations in F<regcomp.c>, F<regcomp.h>, F<regexec.c>.

The second regcomp pass was removed.

=item *

The handling of user-defined C<\p{}> properties (see
L<perlunicode/User-Defined Character Properties>) has been rewritten
to be in C (instead of Perl).  This removed all uses of swashes from
regular expression compilation and execution.

This speeds things up, but in the process several inconsistencies and
bug fixes are made.

=over

=item 1

A few error messages have minor wording changes.  This is essentially
because the new way is integrated into the regex error handling
mechanism that marks the position in the input at which the error
occurred.  That was not possible previously.  The messages now also
contain additional back-trace-like information in case the error occurs
deep in nested calls.

=item 2

A user-defined property is implemented as a perl subroutine with certain
highly constrained naming conventions.  It was documented previously
that the sub would be in the current package if the package was
unspecified.  This turned out not to be true in all cases, but now it
is.

=item 3

All recursive calls are treated as infinite recursion.  Previously they
would cause the interpreter to panic.  Now, they cause the regex pattern
to fail to compile.

=item 4

Similarly, any other error likely would lead to a panic; now to just the
pattern failing to compile.

=item 5

The old mechanism did not detect illegal ranges in the definition of the
property.  Now, the range max must not be smaller than the range min.
Otherwise, the pattern fails to compile.

=item 6

The intention was to have each sub called only once during the lifetime
of the program, so that a property's definition is immutable.  This was
relaxed so that it could be called once for all /i compilations, and
potentially a second time for non-/i (the sub is passed a parameter
indicating which).  However, in practice there were instances when this
was broken, and multiple calls were possible.  Those have been fixed.
Now (besides the /i,non-/i cases) the only way a sub can be called
multiple times is if some component of it has not been defined yet.  For
example, suppose we have sub IsA() whose definition is known at compile
time, and it in turn calls isB() whose definition is not yet known.
isA() will be called each time a pattern it appears in is compiled.  If
isA() also calls isC() and that definition is known, isC() will be
called just once.

=item 7

There were some races and very long hangs should one thread be compiling
the same property as another simultaneously.  These have now been fixed.

=back

=item *

Optimized the static link order of objects for the default case,
when you cannot use lto, pgo, autofdo nor bolt.
Added lto to the default ccflags.
See L<http://perl11.org/blog/bolt.html> and
L<[cperl #381]|https://github.com/perl11/cperl/issues/381>.

=item *

Improve newSVpvn_share

Don't downgrade twice, the is_utf8 flags can be taken from the
returned hek, which does the downgrading to bytes already.

=item *

The oelemfast signature changed from (:Ref,:Int):Any to ():Any.
The object stays now as RV (as pad) and is not taken from the stack,
the index neither.

=back

=head1 Modules and Pragmata

The list of new and updated modules is modified automatically as part of
preparing a Perl release, so the only reason to manually add entries here is if
you're summarising the important changes in the module update. (Also, if the
manually-added details don't match the automatically-generated ones, the
release manager will have to investigate the situation carefully.)

=head2 New Modules and Pragmata

=over 4

=item L<ffi> 0.01c

ffi helpers and ffi types.

=item L<hashiter> 0.02

pragma to allow hash iterators changing keys for back-compat.
See L</Protected hash iterators>.

=item L<inline> 0.01

Yet unused pragma to disable the internal function inlining optimizer,
via C<no inline;>

=item L<YAML::Safe> 0.80

Our new L<YAML::Safe> has been added to the Perl core, replacing our
patched version of L<YAML::XS>.

=back

=head2 Updated Modules and Pragmata

=over 4

=item L<Archive::Tar> 2.32

Fix absolute path handling on VMS

=item L<attributes> 1.15c

Add ffi support, :native(), :encoded(), :nativeconv(), :symbol().

=item L<B> 1.76_10

Fixed for -DPERL_GLOBAL_STRUCT.
Add ffi support: CvXFFI, CvFFLIB. CVf_EXTERN flag

=item L<B::C> 1.57_01

New major release, with dVAR support and
experimental cross support and -m (module) support.
Add $dynamic_copwarn needed for v5.29.7+ (not cperl).
The new script F<buildcc> for module support is not yet
functional, only a placeholder.

=item L<B::Deparse> 1.49_05c

Removed arybase support.

=item L<bignum> 0.51c

Better way to catch warnings.
L<[cpan #126900]|https://rt.cpan.org/Ticket/Display.html?id=126900>.

=item L<bytes> 1.07

Typo in pod

=item L<Compress::Raw::Bzip2>  2.086

Added transparent lzip and zstd delegation in tests.
More meta.

=item L<Compress::Raw::Zlib>  2.086

=item L<Config> 6.23

Add the FREEBSD_KERNEL_VERSION key for FreeBSD.

=item L<Config::Extensions> 0.03

Whitespace only

=item L<Config::Perl::V>  0.31_01

Added USE_THREAD_SAFE_LOCALE

=item L<CPAN> 2.27_02

Update to 2.27-TRIAL upstream with our cperl fixes. Some of our fixes
were accepted upstream.

Fixed critical rmtree bug with a symlink crossing mountpoints
previous directory ~/.cpan/build changed before entering tmp-32186,
expected dev=47 ino=244719549, actual dev=47 ino=33303, aborting at
CPAN/Distribution.pm line 591

Add many upstream tests and distroprefs. Still need to install them.
Added the cperl distroprefs.

Support L<YAML::Safe> for distroprefs.

=item L<CPAN::Meta> 2.150011c

Add L<YAML::Safe> support.

=item L<Cpanel::JSON::XS> 4.12

Make encoder independent on Math::BigInt version

Rethrow error from eval_sv and eval_pv(),
e.g. when Math::BigInt/BigFloat fails.

Fix encoding Inf and NaN from PV and NV slots to JSON_TYPE_INT

Fix memory corruption in sv_to_ivuv() function

Add new method ->require_types

Fix typed json encoder conversion from scalar's PV and NV slot to
JSON_TYPE_INT

Fix inconsistency with warnings in typed json encoder

Fix Perl 5.8.0 support

Fixed minor pod typo

Document invalid recursive callbacks or overloads

Fix unicode strings with BOM corrupt ->utf8 state
The BOM encoding effects only its very own decode call,
not its object.

Fix incr_text refcounts and add incr_rest testcase

Fix encode_stringify string-overload refcnt problem
"Attempt to free unreferenced scalar" with convert_blessed and overload.

=item L<Cwd> 4.78c

Fixed long pathnames test for getcwd() on older systems, like debian-7.11 i386,
which still returns ENAMETOOLONG on large enough buffers.

Fix the HAS_GET_CURRENT_DIR_NAME check, and the is_ENAMETOOLONG macro.
Note that C<get_current_dir_name()> is now in effect, which returns
the current PWD, i.e. fastcwd, and not the C<realpath()> (i.e the
abs_path) of it. This e.g. broke some DBD::File tests, when behind symlinks.

For getcwd with C<get_current_dir_name()> - i.e. fastcwd - add abs_path.
See also L<http://perl11.org/blog/fastcwd.html>

Don't translate F<...> to F<..\..> on Win32.
(an old C<command.com> limitation)
L<[perl #123724]|https://rt.perl.org/Public/Bug/Display.html?id=123724>

Add and use C<Internals::getcwd()>.

=item L<Data::Dumper> 2.173

Restore deparsing support in the XS dumper, on Perl 5.18 and earlier.

Fix bug when dumping globs with quoting (which now happens for
all Unicode glob names)

Behavior change: C<$dumper->Useqq(undef)> is now treated as setting the
"useqq" option, not getting it (and similarly for other options)
L<[perl #113090]|https://rt.perl.org/Public/Bug/Display.html?id=113090>

Quote glob names better; notably, Unicode globs are
now handled correctly.
L<[perl #119831]|https://rt.perl.org/Public/Bug/Display.html?id=119831>

=item L<DB_File>  1.852

ParseOpenInfo() leaks if it croaks
L<https://github.com/pmqs/DB_File/issues/1>

Added hints files, sourced from
L<http://cvsweb.netbsd.org/bsdweb.cgi/pkgsrc/lang/perl5/files/>

=item L<deprecate> 0.04_01

Expanded the documentation

=item L<Devel::Peek> 1.28_03

Adjust Devel::Peek pod to cperl FLAGS

=item L<Devel::PPPort> 3.53_04

PL_in_sub only with v5.29.0c

Merge 3.52 with cperl improvements:

     cperl croak_no_modify adds now the SV to the message.
     support make --silent.
     support devel VERSION with _
     fix deps
     sync embed.fnc with cperl core, with #ifdef USE_CPERL
     sync parts with 5.30 updates

Revert "Use latest blead embed.fnc"

     It changed the meaning of several flags (n=>T, s=>S,M=>x,...) just for
     some apidocs troubles which are easily solved otherwise.
     It breaks backcompat, and breaks the equality of core embed.fnc.
     perl5.30 also rejected it

make regen is now in two modes: cperl or perl5 (as in cperl-core
embed_lib)

Add croak_no_modify_sv

Remove implemented TODOs

Fix for older EUMM <6.46 which has no META_MERGE

Fix 5.6.0 tests with early Test::Harness: add done_testing, support
plan => no_plan, fallback => NN for 5.6.0 (Test::Harness < 2), avoid
Test.pm, skip git diff, as make regen is different there,
skip 3 failing 5.6.0 tests in ppphtest

=item L<Devel::NYTProf> 6.06_03

CVE-2019-11358 + CVE-2015-9251 jquery-1.12.4.js update to
latest v3.4.1.
Also update the two plugins to latest, and adjusted the
tablesorter css.

Adjust the short %PL_DBsub keys (without main::) compatible to
perl5.

Add all the tests, cleanup after the tests.

=item L<DynaLoader> 2.09c

Extend C<dl_find_symbol> on dl_win32 to mimic the POSIX behaviour with
an empty libhandle argument: Search the symbol in all loaded shared
libraries. This is a convenience platform-compat feature for the L<ffi>.

=item L<Encode>  3.01

Add C<Encode::ONLY_PRAGMA_WARNINGS> by default to C<:encoding> layer
variable C<$PerlIO::encoding::fallback>.

ONLY_PRAGMA_WARNINGS reports only those warnings which are
currently enabled by pragma warnings. When ONLY_PRAGMA_WARNINGS
is not set then Encode would report all warnings.
ONLY_PRAGMA_WARNINGS would have no effect when flag
ENCODE_WARN_ON_ERR is not set.

=item L<Errno> 1.30_01

Make F<Errno_pm.PL> compatible with F<< /usr/include/<ARCH>/errno.h >>.
Protect from including some avx512 intrinsics directly on mingw.

=item L<ExtUtils::Embed> 1.36

Added optimize to ccopts, required for C<-flto>.
Fixed documentation of ccopts.
Fixed test to use ccopts, include local -I.., indentation,
remove wrong -O hack.

=item L<ExtUtils::Manifest>  1.72

Minor internal changes only

=item L<ExtUtils::MakeMaker> 8.35_08

Added C<-flto> support for static libs (need the lto plugin) and D for
deterministic builds, using arflags for AR_STATIC_ARGS, not just 'cr'.

fix FULLPERL for win32 cperl

=item L<ExtUtils::ParseXS>

(perl #133654) don't include OUTLIST parameters in the prototype:
The generated prototype (with PROTOTYPES: ENABLE) would include
OUTLIST parameters, but these aren't arguments to the perl function.

=item L<feature> 1.54_01

C<array_base> was removed.

=item L<File::Copy> 2.34

Add note to close or flush filehandles before calling copy or move.

=item L<File::Find> 1.36

C<$File::Find::dont_use_nlink> now defaults to 1 on all platforms.
Fixes L<[perl #133673]|https://rt.perl.org/Public/Bug/Display.html?id=133673>,
L<[perl #128894]|https://rt.perl.org/Public/Bug/Display.html?id=128894>,
and L<[perl #126144]|https://rt.perl.org/Public/Bug/Display.html?id=126144>.

=item L<File::Glob> 1.32

Fatalized File::Glob::glob(), which was deprecated since 5.8. However,
no deprecation message was issued; only perl5.008delta.pod and a
comment in the file mention its deprecation. The warnings was added
with v5.25.10.

=item L<File::Path> 3.16_02c

Fix symlink abort crossing mountpoint with CPAN::Distribution
previous directory ~/.cpan/build changed before entering tmp-32186,
expected dev=47 ino=244719549, actual dev=47 ino=33303, aborting at
CPAN/Distribution.pm line 591

Fix method of generating names for dummy users and groups during testing
(i.e. under docker)
L<[cpan #121967]|https://rt.cpan.org/Ticket/Display.html?id=121967>.

=item L<File::Temp>  0.2309

=item L<GDBM_File> 1.18

Add SECURITY AND PORTABILITY warning paragraph to pod.

=item L<IO> 1.40_02

Skip EINVAL on FreeBSD tests when binding a tcp listener on localhost.

=item L<IO::Compress::Base>  2.086

=item L<IO::Socket::IP> 0.39_03

Allow ETIMEDOUT on FreeBSD INET6 socket with V6Only true.
L<[cpan #128986]|https://rt.cpan.org/Ticket/Display.html?id=128986>

=item L<IO::Zlib> 1.10_01

Fixed parallel testing
L<[cpan #105700]|https://rt.cpan.org/Ticket/Display.html?id=1105700>

Probe for more external gzips, make t/external.t strict safe.

=item L<JSON::PP>  4.04_01

Upstream + keep some of our cperl-specific docs and test improvements.

=item L<lib> 0.65

Hint about $dir/$version is checked by lib.pm and deleted from @INC

=item L<Math::BigInt> 1.999816

Add C<to_base()> and C<from_base()> to L<Math::BigInt> and
corresponding library methods C<_to_base()> and C<_from_base()> to
L<Math::BigInt::Lib>. This was inspired by L<CPAN RT
#122681|https://rt.cpan.org/Ticket/Display.html?id=122681>.

In the documentation for each of the C<to_(bin|hex|oct|bytes)>
methods, add a reference to the corresponding
C<from_(bin|hex|oct|bytes)> method.

C<bnok()> for L<Math::BigInt> and L<Math::BigFloat> now support the
full Kronenburg extension. The behaviour is identical to the behaviour
of the Maple and Mathematica function for negative integers n, k. Add
tests.  L<RT #95628|https://rt.cpan.org/Ticket/Display.html?id=95628>.

Fix POD errors.
L<RT #125141|https://rt.cpan.org/Ticket/Display.html?id=125141>.

Move bitwise operators signed and, signed or, and signed xor from
F<lib/Math/BigInt/CalcEmu.pm> into F<lib/Math/BigInt/Lib.pm>. The file
F<lib/Math/BigInt/CalcEmu.pm> is no longer needed and thus removed.

=item L<Math::BigInt::FastCalc> 0.5008

No code nor test changes.

=item L<Module::Load>  0.34

Added SEE ALSO section to documentation. RT#100575
Unreachable code cleanup

=item L<mro> 1.22_02

Fix -Wmaybe-uninitialized warnings

=item L<NDBM_File> 1.15

Add SECURITY AND PORTABILITY warning paragraph to pod.

=item L<Net::Ping> 2.72

Features

Allow data_size > 1024, up to 65535, i.e. fragmented packets.
It is recommended to stay below 1472 though for the typical 1500 MTU.
Many simple devices do not allow fragmented ICMP packets (> 1472).
L<[cpan #17409]|https://rt.cpan.org/Ticket/Display.html?id=17409>

Bugfixes

Fix the max_datasize documentation

Test fixes

The 2 sudo tests on PERL_CORE with a shared perl lib.
Skip failing freebsd localhost resolver tests.

=item L<ODBM_File> 1.16

Add SECURITY AND PORTABILITY warning paragraph to pod.

=item L<Opcode> 1.40_04c

Added the new setstate and keepstate ops for the new
inliner, variants of nextstate.

Restrict the new op 'enterffi'.

=item L<Parse::CPAN::Meta> 1.5002c

Replace L<YAML::XS> by L<YAML::Safe>.

=item L<perlfaq> 5.20190126

Fixed many typos and pod markup.
Added reference in perlfaq to new ~ syntax in indented here-docs.

=item L<PerlIO::encoding> 0.27_01

Warnings enabled by setting the C<WARN_ON_ERR> flag in
C<$PerlIO::encoding::fallback> are now only produced if warnings are
enabled with C<use warnings "utf8";> or setting C<$^W>.
L<[perl #131683]|https://rt.perl.org/Public/Bug/Display.html?id=131683>

=item L<PerlIO::scalar> 0.30

Allow Off_t smaller than size_t. (Win64 with USE_LARGE_FILES=undef)
L<[perl #133422]|https://rt.perl.org/Public/Bug/Display.html?id=133422>

=item F<perldb.pl> 1.54_03c

Typos in pod.

=item C<podlators>  4.12

Skip the F<man/no-encode.t> test if Encode is already loaded while
running the test suite, which seems to happen sometimes with CPAN
Testers tests.

=item L<Pod::Simple>  4.39c

Merge with updates from 3.39
Releaxed some str types, which could be Pod::Simple::LinkSection also.

=item L<POSIX> 1.87_03

Use quadmath versions of log10, ldexp and signbit.
L<[perl #133510]|https://rt.perl.org/Public/Bug/Display.html?id=133510>

F<stdio.h> on Cygwin doesn't expose C<cuserid> with C<_GNU_SOURCE>

=item L<SDBM_File> 1.15

Add SECURITY AND PORTABILITY warning paragraph to pod.

=item L<re> 0.37_01

Document C<-Drv>

=item L<Safe> 2.40_03c

Fix a test for CORE::dump

=item L<sigtrap> 1.09

Adapt for layers on STDERR, which failed if PERL_UNICODE was set and the
current locale was a UTF-8 locale.

=item L<Socket> 2.029_05

Re-order and comment deprecated IDN constants.
Old MinGW lacks ADDRESS_FAMILY; use USHORT instead (RT128550).
Add PF_LOCAL/AF_LOCAL constants (RT127089).
Provide sockaddr_un on WIN32 (RT128550).

=item L<Storable> 3.15_04

Fix and clarify handling of recurs_sv.
L<[perl #133326]|https://rt.perl.org/Public/Bug/Display.html?id=133326>

Remove exploit code from the pod, which triggered
virus scanners. Note that the perl5 release did that wrong.
L<[perl #133706]|https://rt.perl.org/Public/Bug/Display.html?id=133706>

Keep Storable::Limit, in opposition to L<[perl #133708]|https://rt.perl.org/Public/Bug/Display.html?id=133708>.
Not my idea, but removing it is even worse. The ticket goal is fine,
but the implementation not.

Fix cxt->pseen leak

Enable >2GB AvFILL check on store_hook (64bit)
Too many references returned by STORABLE_freeze.
It wrapped around previously. Fixes Coverity CID #187854.
Move __Storable__.pm into Storable_pm.PL
L<[cperl #374]|https://github.com/perl11/cperl/issues/374>

=item L<Term::ReadKey> 2.38_03

Merge with 2.38

=item L<threads::shared>  1.60

Add extra lock tracing via -DSHARED_TRACE_LOCKS

=item L<Time::HiRes> 1.9760_02

Make utime() available only if we have both fd and name setting
L<[perl #133030]|https://rt.perl.org/Public/Bug/Display.html?id=133030>

Adjust Makefile.PL for windows: the DEFINE() in Makefile.PL
can't be be in sub init() because that sub isn't called on windows

t/itimer.t: avoid race condition. don't truncate nanosec utime

fallback/const-c.inc: Avoid compiler warning showing up on darwin.

=item L<Unicode::Collate>  1.27_01

UCET is updated (for Unicode 10.0.0) as F<Collate/allkeys.txt>.
The default UCA_Version is 36.
F<Locale/*.pl> and F<CJK/Korean.pm> are updated.

U::C::Locale newly supports locale: cu.  tailoring Cyrillic YI as
BYELORUSSIAN-UKRAINIAN I with DIAERESIS, affected locale: kk added
F<loc_cu.t> in t.

Skip redefinition warnings on cperl since 5.27.2 (Hangul in utf8.h)

=item L<Unicode::UCD> 0.71_03

Preserve old-style casing for C<%SCRIPTS>, i.e.
C<Egyptian_hieroglyphs> for C<Egyptian_Hieroglyphs>.

=item L<vars> 1.05_01c

F<vars.pm> no longer disables non-vars strict when checking if strict
vars is enabled.
L<[perl #130674]|https://rt.perl.org/Public/Bug/Display.html?id=130674>

=item L<version> 0.9924_02

More test fixes for 5.6

=item L<warnings> 1.43

Add C<ffi>

=item L<Win32> 0.52_02

Fix various -Wunused warnings, added () usage croaks.
Fixed a -Warray-bounds buffer overflow in LONGPATH,
and two -Wmaybe-uninitialized.

=item L<XS::Typemap> 0.17

Fixed internal leaks

=back

=head2 Removed Modules and Pragmata

=over 4

=item *

L<arybase> was removed.

Setting C<$[> to a non-zero value has been deprecated since Perl 5.12 and
throws a fatal error as of Perl 5.30.
See L<perldeprecation/Assigning non-zero to C<< $[ >> is fatal>

=item *

L<B::Debug> is no longer distributed with the core distribution.
This was announced with v5.28.0. It remains available on CPAN.

=item *

Our patched version of L<YAML::XS> is no longer distributed with the
cperl core distribution.  It was replaced with L<YAML::Safe>.

=back

=head1 Documentation

=head2 Changes to Existing Documentation

We have attempted to update the documentation to reflect the changes
listed in this document.  If you find any we have missed, send email
to L<perlbug@perl.org|mailto:perlbug@perl.org>.

Additionally, the following selected changes have been made:

=head3 L<perlfaq> 5.20180915

=over 4

=item *

prepend "./" to local require calls.
Mojolicious and Dancer2 are not called young anymore.

=back

=head3 L<perlvar>

=over 4

=item *

More specific documentation of paragraph mode.
L<[perl #133722]|https://rt.perl.org/Ticket/Display.html?id=133722>.

=back

=head3 L<perlhacktips>

=over 4

=item *

Added a L<perlhacktips/COMPILER OPTIMIZATIONS> section, with LTO, PGO,
AutoFDO, prelink and BOLT tips.

=back

=head1 Diagnostics

The following additions or changes have been made to diagnostic output,
including warnings and fatal error messages.  For the complete list of
diagnostic messages, see L<perldiag>.

=head2 New Diagnostics

=head3 New Errors

=over 4

=item *

L<Invalid script %s in identifier %s for U+%X, Limited Use scripts are forbidden|perldiag/"Invalid script %s in identifier %s for U+%X, Limited Use scripts are forbidden">
See L</"Disallowed Limited Use Scripts">.

=item *

L<ffi_prep_cif error %d: %s at %s, line %d|perldiag/"ffi_prep_cif error %d: %s at %s, line %d">

=item *

L<An extern sub may not have a prototype|perldiag/"An extern sub may not have a prototype">

=item *

L<ffi not available|perldiag/"ffi not available">

=item *

L<Illegal declaration of extern subroutine %s. Need signature|perldiag/"Illegal declaration of extern subroutine %s. Need signature">

=item *

L<Illegal :encoded(%s) argument|perldiag/"Illegal :encoded(%s) argument">

=item *

L<Illegal :nativeconv(%s) argument|perldiag/"Illegal :nativeconv(%s) argument">

=item *

L<Invalid :%s(%s) attribute argument type|perldiag/"Invalid :%s(%s) attribute argument type">

=item *

L<Missing type for extern sub argument %s|perldiag/"Missing type for extern sub argument %s">

=item *

L<:nativeconv is only valid for :native or extern sub|perldiag/":nativeconv is only valid for :native or extern sub">

=item *

L<Null extern sub symbol|perldiag/"Null extern sub symbol">

=item *

L<:%s() attribute argument missing|perldiag/":%s() attribute argument missing">

=item *

L<:%s is only valid for :native or extern sub|perldiag/":%s is only valid for :native or extern sub">

=item *

L<Unknown ffi return type :%s, assume :void|perldiag/"Unknown ffi return type :%s, assume :void">

=item *

L<Attempt to change hash while iterating over it|perldiag/"Attempt to change hash while iterating over it">

=back

=head3 New Warnings

=over 4

=item *

L<Subroutine &%s::%s masks existing package %s|perldiag/"Subroutine &%s::%s masks existing package %s">

=item *

L<Subroutine &%s masks new package %s|perldiag/"Subroutine &%s masks new package %s"> and
L<Subroutine &%s masks new class %s|perldiag/"Subroutine &%s masks new class %s">

=item *

L<ffi: Possible %s overflow %d|perldiag/"ffi: Possible %s overflow %d">

=item *

L<no ffi without DynaLoader|perldiag/"no ffi without DynaLoader">

=item *

L<:symbol is already resolved|perldiag/":symbol is already resolved">

=item *

L<Use of '%s' in \p{} or \P{} is deprecated because: %s|perldiag/"Use of '%s' in \p{} or \P{} is deprecated because: %s">

=back

=head2 Changes to Existing Diagnostics

=over 4

=item *

cperl fatalized the error on non-grapheme string delimiters (ie. illegal utf8)
in v5.25.3c already, e.g with C<qr ̂foobar̂>.
perl5 did it with v5.29.0 but used 3 error lines instead of just one.

"Use of unassigned code point or non-standalone grapheme for a delimiter"
uses now 3 lines:
"Use of unassigned code point or non-standalone grapheme for a delimiter is not allowed at -, near"
"Use of unassigned code point or non-standalone grapheme for a delimiter is not allowed at -, near"
"Execution of - aborted due to compilation errors."

=item *

cperl fatalized Limited_Use scripts in identifiers with v5.29.2c, they
were valid before and acted like %utf8::EXCLUDED_SCRIPTS, i.e. they
needed to be declared. Now they throw the
L<Invalid script %s in identifier %s for U+%X, Limited Use scripts are forbidden|perldiag/"Invalid script %s in identifier %s for U+%X, Limited Use scripts are forbidden"> error.
See L</"Disallowed Limited Use Scripts">. cperl-only.

=item *

No autovivification of hash slice anymore

Added note that this warning is only enabled with the
lexical C<syntax> warnings category, not C<-w> anymore.

=item *

Unescaped left brace in regex is deprecated here (and will be fatal in
Perl 5.32), passed through in regex; marked by S<<-- HERE> in m/%s/

Added note that cperl allows more. In cperl only the combinations with
C<\NpPbBxog{}> are illegal.

=back

=head1 Utility Changes

=head2 F<Porting/sync-with-cpan>

Stabilized the CoreList updater.

=head1 Configuration and Compilation

=over 4

=item regen.pl

Fixed C<make regen> on cperl with a shared libperl. Need to set
LD_LIBRARY_PATH for a fullperl with ext/Config.

=item configpm

Avoid bumping F<config.sh>/F<config.h> mtimes when adding valid libffi
targets in F<configpm>.  This caused massive miniperl rebuilds, but
is only needed for perl-dependent targets much later.

=item embed.fnc

Added C<#ifdef USE_CPERL> and C<#if PERL_VERSION <28> to the API
declaration in F<embed.fnc>, making clear the perl5 and cperl API
differences in args, argtypes and API declarations.

F<regen/embed_lib.pl> was extended to handle regen-time branches, and
ignore perl5 and older verion branches.

Devel-PPPort F<embed.fnc> can now be the same as the core F<embed.fnc>.

=item -flto

Without C<DEBUGGING> the best C<-flto> Link Time Optimization flag is
now added to the default C<ccflags>.
See L<http://perl11.org/blog/bolt.html> and
L<[cperl #381]|https://github.com/perl11/cperl/issues/381>.

The correct C<-flto=> variant is then used for C<ldflags> and
C<lddlflags> also.  C<cldflags> contains now also the optimize
settings, needed for C<-flto>.

C<ar> is replaced by C<llvm-ar-$llvmsuffix> if needed.
See L</llvmsuffix> below.

=item -ULTO

C<ccflags> or C<cc> containing C<-ULTO> does not probe and add
C<-flto> flags. This is useful for faster B::C testing.
E.g. C<./Configure -des -Accflags=-ULTO>

=item ccname clang

C<ccname> is now set to "clang" for clang, not "gcc".

=item ccname icc

On linux "icc" is also set for C<ccname>, and C<-O3> is preferred over
C<-O2> in most non-DEBUGGING cases with newer compilers.

=item llvmversion

C<llvmversion> string added to config, like "6.0.1-9.1
(tags/RELEASE_601/final)", analog to C<gccversion>. With clang both
variables are set.

=item llvmsuffix

Added C<llvmsuffix> config, for bitcode-enabled ar, ranlib,
llvm-profdata.

=item ar --plugin

Added C<ar --plugin> path to the gcc F<lto_plugin>, required for
binutils C<ar> with static libs with C<-flto>. Esp. on cygwin.
Ditto for C<ranlib>.

=item .autofdo

Added clang and useshrplib support for the two B<.autofdo> targets.
See L<perlhacktips/AutoFDO>.

=item .pgo

Added two B<.pgo> targets, analog to autofdo. See L<perlhacktips/PGO>.

=item archname

Set C<archname> and the target triple C<myarchname> earlier, right
after osname.

=item -Uinstallmandirs

With C<-Uinstallmandirs> all four variables C<installman1dir>,
C<installman3dir>, C<installsiteman1dir> and C<installsiteman3dir> are set to
none, skipping installing all man pages.

=item useffi

Added if F<ffi.h> is being found. If so the C<incpth>, C<ccflags> and
C<libs> is extended to include libffi.

=item ffi_targets

With C<useffi> this space-seperated string is filled with the valid and
supported C<:nativeconv()> ABI's, in uppercase. Matching HAVE_FFI_*
defines in F<config.h>. See L<attributes/nativeconv(STRING)>.

=item usesafehashiter

Disable destructive hash key modifications during iteration by default.
C<use hashiter;> to allow it.
L<[cperl #117]|https://github.com/perl11/cperl/issues/117>

=item doubleinfbytes,doublenanbytes,longdblinfbytes,longdblnanbytes

Fixed the error cases when the double or long double probes returned undef.

=item F<Porting/do-make-cperl-release>

Replace C<sha1sum> with C<sha256sum>, add C<gpg -a -b $pkg>.

=item i_valgrind

Detect F<valgrind/valgrind.h> and check C<RUNNING_ON_VALGRIND> for setting
C<destruct_level> to 2.

=back

=head1 Testing

Tests were added and changed to reflect the other additions and
changes in this release.  Furthermore, these significant changes were
made:

=over 4

=item *

All modules can now be tested B<in parallel>.
From the remaining exceptions F<ext/Pod-Html/t> was fixed a while ago,
and F<cpan/IO-Zlib/t> with this release.

We also removed the remaining exception for files starting with 0.
We assumed before that the reason a test file's name begins with a 0 is to
order its execution among the tests in its directory.  Hence, a
directory containing such files should be tested in serial order.
But in reality there's no such F<t/00-setup.t> test and if so, it would still
be run as very first test. CPAN testing via EUMM and Test::Harness does
not obey this rule neither.
The only existing exception is F<dist/ExtUtils-MakeMaker/t>.
The only module to be fixed was F<ext/FileCache/t>.
cperl-only.

=item *

F<t/TEST> does not need any C<temp_needs_dot> exceptions anymore.
All core modules are now F<.> in C<@INC> clean.
The only module to be fixed was F<cpan/libnet/t>.
cperl-only.

=item *

Thoroughly test paragraph mode, using a new test file,
F<t/io/paragraph_mode.t>.
L<[perl #133722]|https://rt.perl.org/Ticket/Display.html?id=133722>.

=item *

F<lib/utf8_heavy.t> was split away from F<lib/utf8.t> to test
utf8_heavy only functions, mostly SCRIPTS.
cperl-only.

=item *

Added C<is_CI> detection function to F<t/TEST>.

=item *

Honor more B<SKIP_SLOW_TESTS>, esp. with B-C, esp. with C<-flto>.
Document all used ENV vars in F<t/harness>.

=item *

F<op/hash-rt85026.t> finds now almost ever a collision, and skips the test
with C<usesafehashiter> enabled (the default). Such not easily detectable
destructive hash iters are now forbidden, thanks to B<usesafehashiter>.

=item *

F<op/chdir.t> when pwd is a symlink.

=back

=head1 Platform Support

=head2 Platform-Specific Notes

=over 4

=item Oracle Linux

=over 4

=item *

DTrace support has been added by also looking for F</sbin/dtrace>.
Install it with C<sudo yum install -y dtrace-utils dtrace-utils-devel>.

=back

=item Mac OS X

=over 4

=item *

Perl's build and testing process on Mac OS X for C<-Duseshrplib>
builds is now compatible with Mac OS X System Integrity Protection
(B<SIP>).

SIP prevents binaries in F</bin> (and a few other places) being passed
the C<DYLD_LIBRARY_PATH> environment variable.  For our purposes this
prevents C<DYLD_LIBRARY_PATH> from being passed to the shell, which
prevents that variable being passed to the testing or build process,
so running C<perl> couldn't find F<libcperl.dylib>.

To workaround that, the initial build of the F<perl> executable
expects to find F<libcperl.dylib> in the build directory, and the
library path is then adjusted during installation to point to the
installed library.

L<[perl #126706]|https://rt.perl.org/Public/Bug/Display.html?id=126706>

=item *

Macports B<gcc-mp-9 -O> is broken with F<ext/Config>.
You need to use a different compiler.
L<[p5-Config #13]|https://github.com/perl11/p5-Config/issues/13>

=back

=item Win32

=over 4

=item *

C<sleep()> with warnings enabled for a C<USE_IMP_SYS> build no longer
warns about the sleep timeout being too large.
L<[perl #133376]|https://rt.perl.org/Public/Bug/Display.html?id=133376>

=item *

Support for compiling perl on Windows using Microsoft Visual Studio 2019
(containing Visual C++ 14.2) has been added.

=item *

Add DynaLoader fallbacks to C<dl_find_symbol> to mimic the POSIX behaviour with
an empty libhandle argument: Search the symbol in all loaded/most shared
libraries. This is a convenience platform-compat feature for the L<ffi>.

=item *

The new Windows 10 DTrace support has not been tested yet.

=back

=item Linux

=over 4

=item *

The hints now detect newer compilers and sets B<optimize=-O3> by default,
needed for better -flto and inlining support, instead of -O2.

=back

=item FreeBSD

=over 4

=item *

Added F</usr/local/include> to C<incpth>, which helps probing libffi
during F<configpm>.  If was only in ccflags via C<-I>.

=item *

Fixed wrong clang C<llvm-ar$llvmsuffix> and C<arflags>.
BSD F<ar> is fine to use C<-D>.

=item *

Improved clang -flto support, set default optimize to -O3.
-flto still needs the extra gold linker from a clang/llvm ports package
for static archives.

=back

=item AIX

=over 4

=item *

Fix 'for reverse @array' bug on AIX.
L<[perl #133558]|https://rt.perl.org/Public/Bug/Display.html?id=133558>

=back

=item cygwin

=over 4

=item *

Fixed C<boot_Win32CORE> prototype to skip dllexport, fatal with C<-flto>.

=item *

Fixed ar for F<Win32CORE.a> by using the gcc liblto plugin.

=item *

Skip probing for C<-flto> on cygwin. This reliably fails to find a
proper image-base with that many new symbols, the adress space is just
too small:
C<Invalid relocation. Offset 0x.. at address 0x.. doesn't fit into 32 bits>

=back

=item mingw

=over 4

=item *

Fixed Errno from processing some protected intrinsics directly, which fail with
#error "Never use <avx512vpopcntdqintrin.h>, <avx512ifmaintrin.h> directly; include <immintrin.h> instead."
#error "Never use <fmaintrin.h> directly; include <immintrin.h> instead."
#error "Never use <xsavesintrin.h> directly; include <x86intrin.h> instead."

=back

=back

=head1 Internal Changes

=over 4

=item *

The first sizing pass has been eliminated from the regular expression
compiler.  An extra pass may instead be needed in some cases to count
the number of parenthetical capture groups.

=item *

Added C<my_atof3()> to support parsing strings which are not necessarily
NUL-terminated to an NV.
C<grok_atoUV> supports that too now.

=item *

It is now forbidden to malloc more than C<PTRDIFF_T_MAX> bytes.  Much
code (including C optimizers) assumes that all data structures will not
be larger than this, so this catches such attempts before overflow
happens.

=item *

A new function L<perlapi/C<my_strtod>> or its synonym, Strtod(), is
now availabe with the same signature as the libc strtod().  It provides
strotod() equivalent behavior on all platforms, using the best available
precision, depending on platform capabilities and F<Configure> options,
while handling locale-related issues, such as if the radix character
should be a dot or comma.

=item *

Enabled USE_REENTRANT_API with threads by default on all
platforms. See F<reentr.c>.  Previously it was only enabled by default
on darwin.

=item *

Added two new yet unused COP nextstate-like ops: B<setstate> for the first
inlined statement and B<keepstate> for further inlined statements. This
is part of the general inliner preparation, which is not yet fully
enabled. The inliner is only internally used to create composed roles
with different pad indices.

=item *

Added a new C<OP_IS_UNOP_AUXOP(op_type)> macro for consistency.
And a new C<HV_FETCH_NO_SV> flag to allow storing arbitrary pointers
as HeVAL.

=item *

Added the new experimental inliner, which can clone optrees and its
associated data, and fixup the cloned optree for the new target (types,
pad indices). This is not yet enabled by default, only used for
role composition, not yet for general function inlining or loop unrolling.
API: C<op_clone_optree>, plus several internal functions.

For run-time type-checking this new API was added: C<arg_check_type_sv>

=item *

F<embed.fnc> has now seperated C<#ifdef USE_CPERL> and more features
from the plain perl5 API, because many perl5 64bit overflow bugs and
size limitations arise from a broken API already. The lines are
documented as B<perl5 security risk> or B<perl5 limitation>.  The
parser seperates any cperl from the perl5 API differences already at
regen-time, plus the obvious compile-time seperation in the generated
headers via the ifdef's.

=back

=head1 Testing

=over 4

=item *

Added F<t/run/envsize.t> for L</Restrict my_setenv to ARG_MAX>

=back

=head1 Selected Bug Fixes

=over 4

=item *

Regular expression matching no longer leaves stale UTF-8 length magic
when updating C<$^R>. This could result in C<length($^R)> returning
an incorrect value.

=item *

Fixed a failure to match properly.

An EXACTFish regnode has a finite length it can hold for the string
being matched.  If that length is exceeded, a second node is used for
the next segment of the string, for as many regnodes as are needed.
Care has to be taken where to break the string, in order to deal
multi-character folds in Unicode correctly. If we want to break a
string at a place which could potentially be in the middle of a
multi-character fold, we back off one (or more) characters, leaving
a shorter EXACTFish regnode. This backing off mechanism contained
an off-by-one error. L<[perl #133756]|https://rt.perl.org/Ticket/Display.html?id=133756>.

=item *

A bare C<eof> call with no previous file handle now returns true.
L<[perl #133721]|https://rt.perl.org/Ticket/Display.html?id=133721>

=item *

Failing to compile a format now aborts compilation.  Like other errors
in sub-parses this could leave the parser in a strange state, possibly
crashing perl if compilation continued.
L<[perl #132158]|https://rt.perl.org/Ticket/Display.html?id=132158>

=item *

If an in-place edit is still in progress during global destruction and
the process exit code (as stored in C<$?>) is zero, perl will now
treat the in-place edit as successful, replacing the input file with
any output produced.

This allows code like:

  perl -i -ne 'print "Foo"; last'

to replace the input file, while code like:

  perl -i -ne 'print "Foo"; die'

will not.  Partly resolves
L<[perl #133659]|https://rt.perl.org/Ticket/Display.html?id=133659>.

=item *

A regression in 5.28 caused the following code to fail

 close(STDIN); open(CHILD, "|wc -l")'

because the child's stdin would be closed on exec. This has now been fixed.

=item *

Fixed an issue where compiling a regexp containing both compile-time
and run-time code blocks could lead to trying to compile something
which is invalid syntax.

=item *

Fixed build failures with C<< -DNO_LOCALE_NUMERIC >> and
C<< -DNO_LOCALE_COLLATE >>.
L<[perl #133696]|https://rt.perl.org/Ticket/Display.html?id=133696>.

=item *

Prevent the tests in F<< ext/B/t/strict.t >> from being skipped.
L<[perl #133713]|https://rt.perl.org/Ticket/Display.html?id=133713>.

=item *

C<< /di >> nodes ending or beginning in I<s> are now C<< EXACTF >>. We do not
want two C<< EXACTFU >> to be joined together during optimization,
and to form a C<< ss >>, C<< sS >>, C<< Ss >> or C<< SS >> sequence;
they are the only multi-character sequences which may match differently
under C<< /ui >> and C<< /di >>.

=item *

L<SDBM_File> is now more robust with corrupt database files.  The
improvements do not make SDBM files suitable as an interchange format.
L<[perl #132147]|https://rt.perl.org/Public/Bug/Display.html?id=132147>

=item *

C<binmode($fh);> or C<binmode($fh, ':raw');> now properly removes the
C<:utf8> flag from the default C<:crlf> I/O layer on Win32.
L<[perl #133604]|https://rt.perl.org/Public/Bug/Display.html?id=133604>

=item *

C<pack "u", "invalid uuencoding"> now properly NUL terminates the
zero-length SV produced.
L<[perl #132655]|https://rt.perl.org/Public/Bug/Display.html?id=132655>

=item *

The new in-place editing code no longer leaks directory handles.
L<[perl #133314]|https://rt.perl.org/Public/Bug/Display.html?id=133314>

=item *

If an in-place edit is still in progress during global destruction and
the process exit code (as stored in C<$?>) is zero, perl will now
treat the in-place edit as successful, replacing the input file with
any output produced.

This allows code like:

  perl -i -ne 'print "Foo"; last'

to replace the input file, while code like:

  perl -i -ne 'print "Foo"; die'

will not.  Partly resolves
L<[perl #133659]|https://rt.perl.org/Ticket/Display.html?id=133659>.

=item *

Warnings produced from constant folding operations on overloaded
values no longer produce spurious "Use of uninitialized value"
warnings.
L<[perl #132683]|https://rt.perl.org/Public/Bug/Display.html?id=132683>

=item *

Fix for multiconcat "mutator not seen in (lex = ...) .= ..."
L<[perl #133441]|https://rt.perl.org/Public/Bug/Display.html?id=133441>

=item *

Detect more L<perldiag/"This use of C<my()> in a false conditional"> cases,
esp. scalar assignments like C<my $x = 0 if 0;>
L<[perl #133543]|https://rt.perl.org/Public/Bug/Display.html?id=133543>

=item *

Regexp script runs were failing to permit ASCII digits in some cases.
L<[perl #133547]|https://rt.perl.org/Public/Bug/Display.html?id=133547>

=item *

Improve the debugging output for calloc() calls with C<-Dm>.
L<[perl #133439]|https://rt.perl.org/Public/Bug/Display.html?id=133439>

=item *

On Unix-like systems supporting a platform-specific technique for
determining L<< C<$^X>|perlvar/$^X >>, Perl failed to fall back to the
generic technique when the platform-specific one fails (for example, a Linux
system with F</proc> not mounted).  This was a regression in Perl 5.28.0.
L<[perl #133573]|https://rt.perl.org/Public/Bug/Display.html?id=133573>

=item *

The experimental reference aliasing feature was misinterpreting array and
hash slice assignment as being localised, e.g.

    \(@a[3,5,7]) = \(....);

was being interpreted as:

    local \(@a[3,5,7]) = \(....);

L<[perl #133538]|https://rt.perl.org/Public/Bug/Display.html?id=133538>

=item *

C<pack()> no longer can return malformed UTF-8.  It croaks if it would
otherwise return a UTF-8 string that contains malformed UTF-8.  This
protects agains potential security threats.
L<[perl #131642]|https://rt.perl.org/Public/Bug/Display.html?id=131642>

=item *

See L</Any set of digits in the Common script are legal in a script run
of another script>.

=item *

Perl now exposes POSIX C<getcwd> (and on cperl the safer
C<get_current_dir_name>) as C<Internals::getcwd()> if available.  This
is intended for use by C<Cwd.pm> during bootstrapping and may be
removed or changed without notice.  This fixes some bootstrapping
issues while building perl in a directory where some ancestor
directory isn't readable.
L<[perl #133951]|https://rt.perl.org/Public/Bug/Display.html?id=133951>

=item *

Made the C<gmtime_r> and C<localtime_r> fallbacks thread-safe.

=item *

Fix C<valid_ident()> for 128-255 chars not to use isIDFIRST_A nor
isIDCONT_A, _A does not match them.  Fixes F<t/uni/method.t> for chars
like oslash

=item *

Fix C<newSVpvn_share> to store the HEK_WASUTF8 flag if downgraded.
Improve C<newSVpvn_share> to downgrade only once, not twice.

A shared string and a GV with chars in the range 128-255 are downgraded to
bytes without the UTF8 flag. Store at least the HEK_WASUTF8 flag then.

=item *

Check bless name under use strict 'names'.

The second argument to bless, the new classname, is now checked to be a
valid package name identifier when B<strict 'names'> is in effect, and the
name is now normalized.
L<[cperl #376]|https://github.com/perl11/cperl/issues/376>

=item *

Fix cperl 5.28.0c regression disallowing calling subnames with a quote
in a package qualifier position.
L<[cperl #371]|https://github.com/perl11/cperl/issues/371>

This is now valid again:

  sub don't { 0 } print don't;

With v5.28.0c only the declaration C<sub don't { 0 }> was valid, it
accepted the subroutine C<don't>, but the call C<print don't;> was
invalid, it was looking for a second single-quote string delimiter.
Note that in cperl C<'> is no perl4-style package seperator.

=item *

Fixed a L<Safe> double-free of a XS import method in a leaf package.
This really is a problem in Safe (see the outcommented code there),
but the fix was easiest to do in gp_free.

gp_free in global destruction with Safe may double-free a temporary
CV, like C<&Safe::Root0::strict::import@>, i.e. with
F<dist/Storable/t/code.t> The fix is similar to the AV double-free
protection of @_ in gp_free.

=item *

Fixed refs signature args, which dropped their refcnt to 0 when
leaving the sub, so use-after-free stack corruption might occur.  It
also restored by ptr (SV**) not by value (SV*), which was unsafe when
the ptr moved.
L<[cperl #395]|https://github.com/perl11/cperl/issues/395>
cperl-only relevant. perl5 uses args in @_, cperl on the stack.

=item *

C<Mu::new> arguments (fields) are now checked for arity and type violations.
C<Mu::new> is the default cperl constructor for all class objects.
See L<[cperl #387]|https://github.com/perl11/cperl/issues/387>

E.g.

    class Foo { has int $bar };
    my $foo = Foo->new( bar => "baz" );
    print $foo->bar;

fails with 'Too many arguments for method new. Want: 1, but got: 2'.
Named arguments are not yet supported.

    class Foo { has int $bar };
    my $foo = Foo->new( bar => "baz" );
    print $foo->bar;

warns with 'Type of arg $bar to Foo should be int (not Str)'.
cperl-only relevant.

=back

=head1 Known Problems

=over 4

=item *

The perl debugger C<-d> mostly does not work with signatures,
esp. with Test::More tests.
L<[cperl #360]|https://github.com/perl11/cperl/issues/360>

=item *

The latest msys2 64bit gcc-9.1.0 compiler fails on two tests:
F<op/sort.t> and F<op/signatures.t>, similar to the darwin gcc-9 where
the optimizer generates wrong code in XSConfig. There are also huge
performance regressions with the tree-optimizer.
L<[cperl #397]|https://github.com/perl11/cperl/issues/397>

Don't use gcc-9.1 on x86_64.

=item *

Detect shared-only import libraries like F<libNAME.dll.a>, which have
no static counterpart F<libNAME.a>, which happens e.g. for C<libffi>
on B<cygwin> or msys.

=back

=head1 Acknowledgements

cperl 5.30.0c represents approximately 10 months of development since cperl
5.28.0c and contains approximately 580,000 lines of changes across 2,400
files from 52 authors.

Excluding auto-generated files, documentation and release tools, there were
approximately 410,000 lines of changes to 850 .pm, .t, .c and .h files.

The following people are known to have contributed the improvements that
became cperl 5.30.0:

Karl Williamson, Reini Urban, David Mitchell, Tony Cook, James E Keenan,
Sisyphus, Steve Hay, Tomasz Konojacki, H.Merijn Brand, Dagfinn Ilmari
Mannsåker, Nicolas Rochelemagne, Aaron Crane, Daniel Dragan, Craig A.
Berry, Sawyer X, Andy Dougherty, Karen Etheridge, Eugen Konkov, Richard
Leach, Chris 'BinGOs' Williams, Unicode Consortium, Aristotle Pagaltzis,
Abigail, Niko Tyni, Ryan Voots, Zak B. Elep, Pali, Hugo van der Sanden, Yves
Orton, Slaven Rezic, Dan Dedrick, Dominic Hargreaves, François Perrad,
Hauke D, Jakub Wilk, Matthias Bethke, Shlomi Fish, Andreas König, James
Clarke, Jim Cromie, Brian Greenfield, E. Choroba, John SJ Anderson, Dan
Book, Petr Písař, Ed J, Leon Timmermans, David Cantrell, Phil Pearl
(Lobbes), Alexandr Savca, Tina Müller, Graham Knop.

The list above is almost certainly incomplete as it is automatically
generated from version control history including the perl and cperl repos.
In particular, it does not include the names of the (very much appreciated)
contributors who reported issues to the Perl bug tracker and the cperl
github issues.

Many of the changes included in this version originated in the CPAN modules
included in Perl's core. We're grateful to the entire CPAN community for
helping Perl to flourish.

For a more complete list of all of Perl's historical contributors, please
see the F<AUTHORS> file in the Perl source distribution.

Generated with:

    cperl Porting/acknowledgements.pl cperl-5.28.0..HEAD -c

=head1 Reporting Bugs

If you find what you think is a bug, you might check the perl bug database
at L<https://rt.perl.org/> .  There may also be information at
L<http://www.perl.org/> , the Perl Home Page.

If you believe you have an unreported bug, please run the L<cperlbug> program
included with your release.  Be sure to trim your bug down to a tiny but
sufficient test case.  Your bug report, along with the output of C<perl -V>,
will be sent off to perlbug@perl.org to be analysed by the Perl porting team.

If you think it's a cperl specific bug or trust the cperl developers more 
please file an issue at L<https://github.com/perl11/cperl/issues>.

If the bug you are reporting has security implications which make it
inappropriate to send to a publicly archived mailing list, then see
L<perlsec/SECURITY VULNERABILITY CONTACT INFORMATION>
For details of how to report the issue.

=head1 SEE ALSO

The F<Changes> file for an explanation of how to view exhaustive details on
what changed.

The F<INSTALL> file for how to build Perl.

The F<README> file for general stuff.

The F<Artistic> and F<Copying> files for copyright information.

=cut