The roadmap to 5.10 envisages feature based releases, as various items in this
TODO are completed.
-=head2 Needed for a 5.9.4 release
+=head2 Needed for the final 5.10.0 release
-=over
-
-=item *
-
-Review assertions. Review syntax to combine assertions. Assertions could take
-advantage of the lexical pragmas work. L</What hooks would assertions need?>
-
-=item *
-
-C<encoding::warnings> should be turned into a lexical pragma.
-C<encoding> should, too (probably).
-
-=back
-
-=head2 Needed for a 5.9.5 release
-
-=over
-
-=item *
-Implement L</_ prototype character>
-
-=item *
-Implement L</state variables>
-
-=back
-
-=head2 Needed for a 5.9.6 release
-
-Stabilisation. If all goes well, this will be the equivalent of a 5.10-beta.
+Review perlguts. Significant changes have occured since 5.8, and we can't
+release a new version without making sure these are covered.
=head1 Tasks that only need Perl knowledge
infinite loops. This needs to avoid using alarm, as some of the tests are
testing alarm/sleep or timers.
-=head2 POD -> HTML conversion in the core still sucks
+=head2 POD -E<gt> HTML conversion in the core still sucks
Which is crazy given just how simple POD purports to be, and how simple HTML
can be. It's not actually I<as> simple as it sounds, particularly with the
=head2 Parallel testing
+(This probably impacts much more than the core: also the Test::Harness
+and TAP::* modules on CPAN.)
+
The core regression test suite is getting ever more comprehensive, which has
the side effect that it takes longer to run. This isn't so good. Investigate
whether it would be feasible to give the harness script the B<option> of
=head2 Make Schwern poorer
-We should have for everything. When all the core's modules are tested,
+We should have tests for everything. When all the core's modules are tested,
Schwern has promised to donate to $500 to TPF. We may need volunteers to
hold him upside down and shake vigorously in order to actually extract the
cash.
-See F<t/lib/1_compile.t> for the 3 remaining modules that need tests.
-
=head2 Improve the coverage of the core tests
-Use Devel::Cover to ascertain the core's test coverage, then add tests that
-are currently missing.
+Use Devel::Cover to ascertain the core modules's test coverage, then add
+tests that are currently missing.
=head2 test B
There is a script F<embed.pl> that generates several header files to prefix
all of Perl's symbols in a consistent way, to provide some semblance of
namespace support in C<C>. Functions are declared in F<embed.fnc>, variables
-in F<interpvar.h> and F<thrdvar.h>. Quite a few of the functions and variables
+in F<interpvar.h>. Quite a few of the functions and variables
are conditionally declared there, using C<#ifdef>. However, F<embed.pl>
doesn't understand the C macros, so the rules about which symbols are present
when is duplicated in F<makedef.pl>. Writing things twice is bad, m'kay.
It would be good to teach C<embed.pl> to understand the conditional
compilation, and hence remove the duplication, and the mistakes it has caused.
+=head2 use strict; and AutoLoad
+Currently if you write
+ package Whack;
+ use AutoLoader 'AUTOLOAD';
+ use strict;
+ 1;
+ __END__
+ sub bloop {
+ print join (' ', No, strict, here), "!\n";
+ }
+then C<use strict;> isn't in force within the autoloaded subroutines. It would
+be more consistent (and less surprising) to arrange for all lexical pragmas
+in force at the __END__ block to be in force within each autoloaded subroutine.
+There's a similar problem with SelfLoader.
=head1 Tasks that need a little sysadmin-type knowledge
coverage, and have C<Configure> and the F<Makefile> do all the right things
automatically.
-=head2 Make Config.pm cope with differences between build and installed perl
+=head2 Make Config.pm cope with differences between built and installed perl
Quite often vendors ship a perl binary compiled with their (pay-for)
compilers. People install a free compiler, such as gcc. To work out how to
export list is correct, and to build a perl that does not pollute the global
namespace with private symbols.
-
-
+=head2 Cross-compile support
+
+Currently C<Configure> understands C<-Dusecrosscompile> option. This option
+arranges for building C<miniperl> for TARGET machine, so this C<miniperl> is
+assumed then to be copied to TARGET machine and used as a replacement of full
+C<perl> executable.
+
+This could be done little differently. Namely C<miniperl> should be built for
+HOST and then full C<perl> with extensions should be compiled for TARGET.
+This, however, might require extra trickery for %Config: we have one config
+first for HOST and then another for TARGET. Tools like MakeMaker will be
+mightily confused. Having around two different types of executables and
+libraries (HOST and TARGET) makes life interesting for Makefiles and
+shell (and Perl) scripts. There is $Config{run}, normally empty, which
+can be used as an execution wrapper. Also note that in some
+cross-compilation/execution environments the HOST and the TARGET do
+not see the same filesystem(s), the $Config{run} may need to do some
+file/directory copying back and forth.
=head1 Tasks that need a little C knowledge
when making a tarball, yet leave the default source saying "I'm not the
official release".
-=head2 Ordering of "global" variables.
-
-F<thrdvar.h> and F<intrpvarh> define the "global" variables that need to be
-per-thread under ithreads, where the variables are actually elements in a
-structure. As C dictates, the variables must be laid out in order of
-declaration. There is a comment
-C</* Important ones in the first cache line (if alignment is done right) */>
-which implies that at some point in the past the ordering was carefully chosen
-(at least in part). However, it's clear that the ordering is less than perfect,
-as currently there are things such as 7 C<bool>s in a row, then something
-typically requiring 4 byte alignment, and then an odd C<bool> later on.
-(C<bool>s are typically defined as C<char>s). So it would be good for someone
-to review the ordering of the variables, to see how much alignment padding can
-be removed.
-
-It's also worth checking that all variables are actually used. Perl 5.8.0
-shipped with C<PL_nrs> still defined in F<thrdvar.h>, despite it being unused
-since a change over a year earlier. Had this been spotted before release, it
-could have been removed, but now it has to remain in the 5.8.x releases to
-keep the structure the same size, to retain binary compatibility.
-
-It's probably worth checking if all need to be the types they are. For example
-
- PERLVAR(Ierror_count, I32) /* how many errors so far, max 10 */
-
-might work as well if stored in a signed (or unsigned) 8 bit value, if the
-comment is accurate. C<PL_multi_open> and C<PL_multi_close> can probably
-become C<char>s. Finding variables to downsize coupled with rearrangement
-could shrink the interpreter structure; a size saving which is multiplied by
-the number of threads running.
-
=head2 Profile Perl - am I hot or not?
The Perl source code is stable enough that it makes sense to profile it,
want to determine what ops I<really> are the most commonly used. And in turn
suggest evictions and promotions to achieve a better F<pp_hot.c>.
-=head2 Shrink struct context
-
-In F<cop.h>, we have
-
- struct context {
- U32 cx_type; /* what kind of context this is */
- union {
- struct block cx_blk;
- struct subst cx_subst;
- } cx_u;
- };
-
-There are less than 256 values for C<cx_type>, and the constituent parts
-C<struct block> and C<struct subst> both contain some C<U8> and C<U16> fields,
-so it should be possible to move them to the first word, and share space with
-a C<U8> C<cx_type>, saving 1 word.
-
=head2 Allocate OPs from arenas
Currently all new OP structures are individually malloc()ed and free()d.
the various OP structures from arenas. The SV arena code can probably be
re-used for this.
-=head2 Merge the win32 and wince codebases
+=head2 Improve win32/wince.c
-Currently, code used to build Perl on Win32 and WinCE are maintained
-separately, but use much of the same code. We currently have a very high
-probability of the code diverging when it shouldn't. Ideally, the code
-for the two systems should be merged so that common code between the two
-could be shared.
+Currently, numerous functions look virtually, if not completely,
+identical in both C<win32/wince.c> and C<win32/win32.c> files, which can't
+be good.
+=head2 Use secure CRT functions when building with VC8 on Win32
-=head1 Tasks that need a knowledge of XS
+Visual C++ 2005 (VC++ 8.x) deprecated a number of CRT functions on the basis
+that they were "unsafe" and introduced differently named secure versions of
+them as replacements, e.g. instead of writing
-These tasks would need C knowledge, and roughly the level of knowledge of
-the perl API that comes from writing modules that use XS to interface to
-C.
+ FILE* f = fopen(__FILE__, "r");
-=head2 shrink C<PVBM>s
+one should now write
-By removing unused elements and careful re-ordering, the structures for C<AV>s,
-C<HV>s, C<CV>s and C<GV>s have recently been shrunk considerably. C<PVIO>s
-probably aren't worth it, as typical programs don't use more than 8, and
-(at least) C<Filter::Util::Call> uses C<SvPVX>/C<SvCUR>/C<SvLEN> on a C<PVIO>,
-so it would mean code changes to modules on CPAN. C<PVBM>s might have some
-savings to win.
+ FILE* f;
+ errno_t err = fopen_s(&f, __FILE__, "r");
-=head2 Implicit Latin 1 => Unicode translation
+Currently, the warnings about these deprecations have been disabled by adding
+-D_CRT_SECURE_NO_DEPRECATE to the CFLAGS. It would be nice to remove that
+warning suppressant and actually make use of the new secure CRT functions.
-Conversions from byte strings to UTF-8 currently map high bit characters
-to Unicode without translation (or, depending on how you look at it, by
-implicitly assuming that the byte strings are in Latin-1). As perl assumes
-the C locale by default, upgrading a string to UTF-8 may change the
-meaning of its contents regarding character classes, case mapping, etc.
-This should probably emit a warning (at least).
+There is also a similar issue with POSIX CRT function names like fileno having
+been deprecated in favour of ISO C++ conformant names like _fileno. These
+warnings are also currently suppressed with the compiler option /wd4996. It
+might be nice to do as Microsoft suggest here too, although, unlike the secure
+functions issue, there is presumably little or no benefit in this case.
-This task is incremental - even a little bit of work on it will help.
+=head1 Tasks that need a knowledge of XS
+
+These tasks would need C knowledge, and roughly the level of knowledge of
+the perl API that comes from writing modules that use XS to interface to
+C.
=head2 autovivification
temporarily retired in 5.8.1, and the -C has been repurposed, see
L<perlrun>.)
+Most probably the right way to do this would be this:
+L</"Virtualize operating system access">.
+
=head2 Unicode in %ENV
Currently the %ENV entries are always byte strings.
+See L</"Virtualize operating system access">.
+
+=head2 Unicode and glob()
+
+Currently glob patterns and filenames returned from File::Glob::glob()
+are always byte strings. See L</"Virtualize operating system access">.
=head2 use less 'memory'
running a shell. readpipe() (the function behind qx//) could be similarly
extended.
+=head2 strcat(), strcpy(), strncat(), strncpy(), sprintf(), vsprintf()
+
+Maybe create a utility that checks after each libperl.a creation that
+none of the above (nor sprintf(), vsprintf(), or *SHUDDER* gets())
+ever creep back to libperl.a.
+
+ nm libperl.a | ./miniperl -alne '$o = $F[0] if /:$/; print "$o $F[1]" if $F[0] eq "U" && $F[1] =~ /^(?:strn?c(?:at|py)|v?sprintf|gets)$/'
+
+Note, of course, that this will only tell whether B<your> platform
+is using those naughty interfaces.
+
+=head2 Audit the code for destruction ordering assumptions
+
+Change 25773 notes
+
+ /* Need to check SvMAGICAL, as during global destruction it may be that
+ AvARYLEN(av) has been freed before av, and hence the SvANY() pointer
+ is now part of the linked list of SV heads, rather than pointing to
+ the original body. */
+ /* FIXME - audit the code for other bugs like this one. */
+
+adding the C<SvMAGICAL> check to
+
+ if (AvARYLEN(av) && SvMAGICAL(AvARYLEN(av))) {
+ MAGIC *mg = mg_find (AvARYLEN(av), PERL_MAGIC_arylen);
+
+Go through the core and look for similar assumptions that SVs have particular
+types, as all bets are off during global destruction.
+
+=head2 Extend PerlIO and PerlIO::Scalar
+
+PerlIO::Scalar doesn't know how to truncate(). Implementing this
+would require extending the PerlIO vtable.
+
+Similarly the PerlIO vtable doesn't know about formats (write()), or
+about stat(), or chmod()/chown(), utime(), or flock().
+(For PerlIO::Scalar it's hard to see what e.g. mode bits or ownership
+would mean.)
+PerlIO doesn't do directories or symlinks, either: mkdir(), rmdir(),
+opendir(), closedir(), seekdir(), rewinddir(), glob(); symlink(),
+readlink().
+
+=head2 -C on the #! line
+
+It should be possible to make -C work correctly if found on the #! line,
+given that all perl command line options are strict ASCII, and -C changes
+only the interpretation of non-ASCII characters, and not for the script file
+handle. To make it work needs some investigation of the ordering of function
+calls during startup, and (by implication) a bit of tweaking of that order.
=head1 Tasks that need a knowledge of the interpreter
These tasks would need C knowledge, and knowledge of how the interpreter works,
or a willingness to learn.
-=head2 lexical pragmas
+=head2 Implement $value ~~ 0 .. $range
-Document the new support for lexical pragmas in 5.9.3 and how %^H works.
-Maybe C<re>, C<encoding>, maybe other pragmas could be made lexical.
+It would be nice to extend the syntax of the C<~~> operator to also
+understand numeric (and maybe alphanumeric) ranges.
=head2 Attach/detach debugger from running program
The old perltodo notes that lvalue functions don't work in the debugger. This
would be good to fix.
-=head2 _ prototype character
+=head2 regexp optimiser optional
-Study the possibility of adding a new prototype character, C<_>, meaning
-"this argument defaults to $_".
+The regexp optimiser is not optional. It should configurable to be, to allow
+its performance to be measured, and its bugs to be easily demonstrated.
-=head2 state variables
+=head2 delete &function
-C<my $foo if 0;> is deprecated, and should be replaced with
-C<state $x = "initial value\n";> the syntax from Perl 6.
-Rafael has sent a first cut patch to perl5-porters.
+Allow to delete functions. One can already undef them, but they're still
+in the stash.
-=head2 regexp optimiser optional
+=head2 C</w> regex modifier
-The regexp optimiser is not optional. It should configurable to be, to allow
-its performance to be measured, and its bugs to be easily demonstrated.
+That flag would enable to match whole words, and also to interpolate
+arrays as alternations. With it, C</P/w> would be roughly equivalent to:
-=head2 UNITCHECK
+ do { local $"='|'; /\b(?:P)\b/ }
-Introduce a new special block, UNITCHECK, which is run at the end of a
-compilation unit (module, file, eval(STRING) block). This will correspond to
-the Perl 6 CHECK. Perl 5's CHECK cannot be changed or removed because the
-O.pm/B.pm backend framework depends on it.
+See L<http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2007-01/msg00400.html>
+for the discussion.
=head2 optional optimizer
The old perltodo notes "Look at the "reification" code in C<av.c>".
-=head2 What hooks would assertions need?
-
-Assertions are in the core, and work. However, assertions needed to be added
-as a core patch, rather than an XS module in ext, or a CPAN module, because
-the core has no hooks in the necessary places. It would be useful to
-investigate what hooks would need to be added to make it possible to provide
-the full assertion support from a CPAN module, so that we aren't constraining
-the imagination of future CPAN authors.
-
=head2 Properly Unicode safe tokeniser and pads.
The tokeniser isn't actually very UTF-8 clean. C<use utf8;> is a hack -
tokeniser ignores the UTF-8-ness of C<PL_rsfp>, or any SVs returned from
source filters. All this could be fixed.
-
-
-
+=head2 The yada yada yada operators
+
+Perl 6's Synopsis 3 says:
+
+I<The ... operator is the "yada, yada, yada" list operator, which is used as
+the body in function prototypes. It complains bitterly (by calling fail)
+if it is ever executed. Variant ??? calls warn, and !!! calls die.>
+
+Those would be nice to add to Perl 5. That could be done without new ops.
+
+=head2 Virtualize operating system access
+
+Implement a set of "vtables" that virtualizes operating system access
+(open(), mkdir(), unlink(), readdir(), getenv(), etc.) At the very
+least these interfaces should take SVs as "name" arguments instead of
+bare char pointers; probably the most flexible and extensible way
+would be for the Perl-facing interfaces to accept HVs. The system
+needs to be per-operating-system and per-file-system
+hookable/filterable, preferably both from XS and Perl level
+(L<perlport/"Files and Filesystems"> is good reading at this point,
+in fact, all of L<perlport> is.)
+
+This has actually already been implemented (but only for Win32),
+take a look at F<iperlsys.h> and F<win32/perlhost.h>. While all Win32
+variants go through a set of "vtables" for operating system access,
+non-Win32 systems currently go straight for the POSIX/UNIX-style
+system/library call. Similar system as for Win32 should be
+implemented for all platforms. The existing Win32 implementation
+probably does not need to survive alongside this proposed new
+implementation, the approaches could be merged.
+
+What would this give us? One often-asked-for feature this would
+enable is using Unicode for filenames (and other "names" like %ENV,
+usernames, hostnames, and so forth.) But this would also allow for
+things like virtual filesystems, virtual networks, and "sandboxes"
+(though as long as dynamic loading of random object code is allowed,
+not very safe sandboxes since external code of course know not of
+Perl's vtables). An example of a smaller "sandbox" is that this
+feature can be used to implement per-thread working directories:
+Win32 already does this.
=head1 Big projects
Tasks that will get your name mentioned in the description of the "Highlights
-of 5.10"
+of 5.12"
=head2 make ithreads more robust
One bit would be to write the missing code in sv.c:Perl_dirp_dup.
+Fix Perl_sv_dup, et al so that threads can return objects.
+
=head2 iCOW
Sarathy and Arthur have a proposal for an improved Copy On Write which
This will allow the use of a regex from inside (?{ }), (??{ }) and
(?(?{ })|) constructs.
+
+=head2 Add class set operations to regexp engine
+
+Apparently these are quite useful. Anyway, Jeffery Friedl wants them.
+
+demerphq has this on his todo list, but right at the bottom.
projects / p5sagit/p5-mst-13.2.git / blobdiff