=item *
+Implement L</state variables> (mostly done currently)
+
+=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 be turned into a lexical pragma (probably).
=back
=over
=item *
+
Implement L</_ prototype character>
=item *
-Implement L</state variables>
+
+Review smart match semantics in light of Perl 6 developments.
=back
=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.
various times worked to cut it down. There is probably still fat to cut out -
for example POSIX passes Exporter some very memory hungry data structures.
+=head2 embed.pl/makedef.pl
+
+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
+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.
Or if you prefer, tasks that you would learn from, and broaden your skills
base...
-=head2 Relocatable perl
-
-The C level patches needed to create a relocatable perl binary are done, as
-is the work on F<Config.pm>. All that's left to do is the C<Configure> tweaking
-to let people specify how they want to do the install.
-
=head2 make HTML install work
There is an C<installhtml> target in the Makefile. It's marked as
as
=item substr EXPR,OFFSET,LENGTH,REPLACEMENT
-
=item substr EXPR,OFFSET,LENGTH
-
=item substr EXPR,OFFSET
and different parameter lists having different meanings. (eg C<select>)
a binary distribution better describes the installed machine, when the
installed machine differs from the build machine in some significant way.
-=head2 make parallel builds work
-
-Currently parallel builds (such as C<make -j3>) don't work reliably. We believe
-that this is due to incomplete dependency specification in the F<Makefile>.
-It would be good if someone were able to track down the causes of these
-problems, so that parallel builds worked properly.
-
=head2 linker specification files
Some platforms mandate that you provide a list of a shared library's external
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 should be done litle differently. Namely C<miniperl> should be built for
+HOST and then full C<perl> with extensions should be compiled for TARGET.
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.
-=head2 am I hot or not?
+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 idea of F<pp_hot.c> is that it contains the I<hot> ops, the ops that are
-most commonly used. The idea is that by grouping them, their object code will
-be adjacent in the executable, so they have a greater chance of already being
-in the CPU cache (or swapped in) due to being near another op already in use.
+The Perl source code is stable enough that it makes sense to profile it,
+identify and optimise the hotspots. It would be good to measure the
+performance of the Perl interpreter using free tools such as cachegrind,
+gprof, and dtrace, and work to reduce the bottlenecks they reveal.
+
+As part of this, the idea of F<pp_hot.c> is that it contains the I<hot> ops,
+the ops that are most commonly used. The idea is that by grouping them, their
+object code will be adjacent in the executable, so they have a greater chance
+of already being in the CPU cache (or swapped in) due to being near another op
+already in use.
Except that it's not clear if these really are the most commonly used ops. So
-anyone feeling like exercising their skill with coverage and profiling tools
-might 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>.
+as part of exercising your skills with coverage and profiling tools you might
+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;
+ };
-=head1 Tasks that need a knowledge of XS
+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.
-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 Allocate OPs from arenas
-=head2 IPv6
+Currently all new OP structures are individually malloc()ed and free()d.
+All C<malloc> implementations have space overheads, and are now as fast as
+custom allocates so it would both use less memory and less CPU to allocate
+the various OP structures from arenas. The SV arena code can probably be
+re-used for this.
-Clean this up. Check everything in core works
+=head2 Improve win32/wince.c
-=head2 shrink C<GV>s, C<CV>s
+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.
-By removing unused elements and careful re-ordering, the structures for C<AV>s
-and C<HV>s have recently been shrunk considerably. It's probable that the same
-approach would find savings in C<GV>s and C<CV>s, if not all the other
-larger-than-C<PVMG> types.
-=head2 UTF8 caching code
+=head1 Tasks that need a knowledge of XS
-The string position/offset cache is not optional. It should be.
+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 shrink C<PVBM>s
+
+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.
=head2 Implicit Latin 1 => Unicode translation
debugger on a running Perl program, although I'm not sure how it would be
done." ssh and screen do this with named pipes in /tmp. Maybe we can too.
-=head2 Constant folding
-
-The peephole optimiser should trap errors during constant folding, and give
-up on the folding, rather than bailing out at compile time. It is quite
-possible that the unfoldable constant is in unreachable code, eg something
-akin to C<$a = 0/0 if 0;>
-
=head2 LVALUE functions for lists
The old perltodo notes that lvalue functions don't work for list or hash
C<my $foo if 0;> is deprecated, and should be replaced with
C<state $x = "initial value\n";> the syntax from Perl 6.
-
-=head2 @INC source filter to Filter::Simple
-
-The second return value from a sub in @INC can be a source filter. This isn't
-documented. It should be changed to use Filter::Simple, tested and documented.
+Rafael has sent a first cut patch to perl5-porters.
=head2 regexp optimiser optional
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 -
+variable names are stored in stashes as raw bytes, without the utf-8 flag
+set. The pad API only takes a C<char *> pointer, so that's all bytes too. The
+tokeniser ignores the UTF-8-ness of C<PL_rsfp>, or any SVs returned from
+source filters. All this could be fixed.
+=head2 Integrate Russ Allbery's strlcat/strlcpy implementation
+And remove the last remaining uses of strcat() and strcpy(). Also, add
+my_strlcat() and my_strlcpy() to Devel::PPPort so previous versions of Perl can
+use these APIs.
=head1 Big projects
projects / p5sagit/p5-mst-13.2.git / blobdiff