This Week on perl5-porters - 26 December 2005 - 1 January 2006
A happy new year for Perl 5 porters and everybody. The holiday seemed
to bring a lot of spare time for Perl 5 porters and they made good use
of it. Hey, what those funny people are doing around in this mailing
list?
Perl on z/OS
In the last weeks, Rajarshi Das and others raised some interest for
the Perl port to z/OS, an EBCDIC platform, and started some threads on
related issues.
* iso-2022-jp encoding * Rajarshi Das asked for help to understand why
iso-2022-jp encoding is unknown on z/OS. Sadahiro Tomoyuki showed some
evidence that "Encode" is not ready to support "Encode::JP" (the
module which supports iso-2002-jp and other Japanese encodings) on
EBCDIC. Nick Ing-Simmons also had some comments about the weirdness of
scripts starting with an EBCDIC dialect and then switching to an
ASCII-oid escape encoding like iso-2002-jp is. Rajarshi Das tried some
changes against "Encode" sources and his doubts remained. Sadahiro
Tomoyuki tried to help Rajarshi understand the involved subtleties.
This thread has not reached a conclusion (unless I missed something)
and Rajarshi opened ticket #16663.
http://xrl.us/jgcu
*Configuration Error for p59x26223* Rajarshi was having fun
configuring and building p59x26223 (whatever that is) on z/OS v1.7,
but some show-stopping errors were popping and he called for help.
Jarkko Hietaniemi analyzed the situation which is due to a silly
warning of a compiler who wants to know too much. Jarkko posted
something to Rajarshi to try, which worked, until it hit an error in
building "Compress::Zlib". Paul Marquess wondered about a fix of a
couple of weeks ago, which then made possible to Rajarshi to build
Perl. (This fix is going to be officially introduced to
"Compress::Zlib".) Jarkko asked for more details on a failure around
"Time::HiRes", which went unanswered.
http://xrl.us/jgcv
* Fixing t/uni/class.t on EBCDIC * Rajarshi Das brought a patch to
t/uni/class.t on perl-5.8.7 which fixes the test on EBCDIC (z/OS 1.4).
The test case changes worked fine with Sadahiro Tomoyuki's patch for
utf8.c but, to Steve Peters, they seemed too heavy for a test.
Sadahiro Tomoyuki followed up with a lighter change, untried yet on
EBCDIC, until Rajarshi tried it successfully, but he had a few
comments on why things were done that way in the first patch. Last
week, Steve Peters pinged about what changes were needed and the
current state of tests outcome.
http://xrl.us/jgcw
* "Expect", Anyone? * Robert Zielazinski wondered if someone had
played with porting the "Expect" module to z/OS. He tried once with no
luck on previous releases. No one answered, maybe because "Expect",
which is not a core module, and z/OS are not in the current agenda of
porters.
http://xrl.us/jgcx
* About ext/B/t/optree_specials.t * Back in October 5, Mohammad Yaseen
commented on the output of running the ext/B/t/optree_specials.t test
on EBCDIC platform z/OS. At Christmas' eve, Nicholas Clark guessed it
probably had to do with different representation of the same string on
non-ASCII systems, leading to different numeric hash values.
http://xrl.us/jgcy
"runperl" and @INC
Yitzchak Scott-Thoennes delved into a long-standing test failure he
had been seeing on Cygwin, and diagnosed two separate problems. One
about test data in the real lib directory (lib/charnames.t). The
second about "runperl()" using real @INC directories. Yitzchak
proposed a patch with "runperl()" using "TestInit.pm" and saw only a
failure at op/stash.t which had to do with a yet unfixed bug. With no
immediate solution, Yitzchak opened for others to try it out, before
sweeping the problem to under the carpet as a paliative measure. After
a long silence, Rafael Garcia-Suarez saw op/stash.t to succeed and
t/run/switchd.t to fail. Nicholas Clark noticed failures with threaded
perls which he tracked down and corrected with some changes.
http://xrl.us/jgcz
Andy Plays Santa
Andy Lester was one of the guys that spent a little more time with
Perl at the end of the year.
Ho! Ho! Ho! consting and NULLing
http://xrl.us/jgc2
Faster Perl_sv_derived_from
http://xrl.us/jgc3
Andy speeds (rn|n)?instr
http://xrl.us/jgc4
Before LIKELY() stuff
http://xrl.us/jgc5
Getting SVREFCNT right
http://xrl.us/jgc6
More cleanup and tight prototypes with NN
http://xrl.us/jgc7
Constant pointer parms
http://xrl.us/jgc8
Making 0 pointers to NULLs
http://xrl.us/jgc9
Some of this work by Andy was inspired by analysis of the coverage
stats which Sébastien "maddingue" Aperghis-Tramoni made available.
Graham Barr pointed there might some catches for the optimization of
"(rn|n)?instr" with respect to modern CPUs. And Rafael Garcia-Suarez
supposed the "SVREFCNT" fix comes with no impact on performance. At
last, Andy launched the support for GCC builtins "__builtin_expect"
and "__builtin_choose_expr" in source code, which later may be applied
to hot spots detected in maddingue's reports. Rafael Garcia-Suarez
preferred to defer the introduction of these features and the
corresponding Configure patch after 5.9.3 and H. Merijn Brand will
have everything ready by this time.
Coverages stats by maddingue
http://www.maddingue.net/perlcover/
Support for two GCC builtins
http://xrl.us/jgda
Longdoubles on Linux 2.6 with gcc-4
H.Merijn Brand perceived some 'M' failures in smokes with longdoubles
on Linux 2.6.12 and up with gcc-4.0.2 and up. Merijn wondered if
others were having similar issues. Rafael Garcia-Suarez reported on
successful builds with similar settings. Later, Merijn found the
problem to be the gcc he had been using, a prerelease 4.0.2, and
confirmed perl configures and builds fine with 4.0.2 release and 4.0.3
prerelease. There remained some problems Jim Cromie had seen which
cast some doubts on the use of long doubles in current Perl sources.
http://xrl.us/jgdb
On "B::Lint" with Plugins
Yves Orton pinched a sneaky issue on Win32 on ext/b/t/lint.t. And,
while we're on "B::Lint", let me remind the comments of Joshua ben
Jore on the last summary. With respect to "B::Lint" plugins, Joshua
made clear that (1) benchmarking is needed to establish the cost of
plugins against the embedded existing checks, (2) he doesn't see the
value of fussing around just to make examples for people, as he'll be
publishing more plugins that may serve this end, (3) he may as well
make available some material (presentation slides) on doing lint-like
checks after some updating.
Yves' deed on Win32's sake
http://xrl.us/jgdc
Joshua explains stuff
http://xrl.us/jgdd
"CPANPLUS" in Core?
Yitzchak Scott-Thoennes remembered that, in June, Rafael announced the
addition of "Archive::Tar" to the core, as the last addition before
"CPANPLUS" and asked what next. A long discusssion ensued, with lots
of pros and cons. To make it short, among the drawbacks, there are:
core is big enough; CPAN.pm is stable and "CPANPLUS" caused much pain
so far; "CPANPLUS" is a little too generous with memory requirements;
some say it is too Linux centric; some issues on requisites may
remain, like "IPC::Run". Andreas Koenig also reminded us of the new
goodness added to the last versions of CPAN. On the side of the
advantages, "CPANPLUS" provides an API which "is a real pleasure";
"CPAN" is not really light, but according to Jos "kane" Bouman,
"CPANPLUS" by design trades memory for speed. Believe me, many things
have been said. If you want real details, follow the thread.
http://xrl.us/jgde
make -j2 disttest Fails
Nicholas noticed a parallel make of the disttest target ("make -j2
disttest") was failing. Steve Peters came to the rescue: the problem
was apparently related solely to BSD-based makes and not GNU make.
"make -j2 -B disttest" works for BSD make - the man page says -j turns
compatibility off, and -B restores it. The issue: cd's in GNU make
works for the current command and returns to the start directory after
completed.
http://xrl.us/jgdf
"Module::Build" 0.27_04
The candidate for core, "Module::Build", reached release 0.27_04,
announced by Ken Williams.
http://xrl.us/jgdg
"CPAN" 1.80_58
Andreas Koenig brought CPAN in blead to 1.80_58.
Doc Patches
Who said programmers don't like to write documentation? If that's
true, they at least enjoy fixing POD.
* "UNIVERSAL": Don't Use Methods as Functions * chromatic proposed a
patch against lib/UNIVERSAL.pm to remove the recommendation to use
"isa()", "can()", and "VERSION()" as functions, responsible for too
much damage in his view. The suggestion might seem a natural followup
of chromatic's contribution as one of the authors of the controversial
"UNIVERSAL::can" and the not so rebellious "UNIVERSAL::isa". Yves
Orton proposed instead a fix with basically the same rationale of the
the mentioned modules, which Rafael thought to be a pretty big change,
making "UNIVERSAL::isa" inaccessible to those which override "isa". In
such grounds, Rafael declined the patch as it undocumented existing
functionality and asked for a perspective change. Rafael also reminded
that "Scalar::Util::reftype" can be used in place of "UNIVERSAL::isa".
And chromatic brought a new patch "that moves the broken code to the
end, where people will hopefully not see it." The patch pleased Yves
and Rafael and got applied as change #26466.
chromatic's first attack
http://xrl.us/jgdh
chromatic's coup de grâce
http://xrl.us/jgdi
* Bad Example in perlop * Ben Okopnik, in ticket #38008, pointed the
misleading example on the flipflop operator in pod/perlop.pod, which
included a label called 'line'. Rafael Garcia-Suarez made it right
with change #26468.
next line if (1 .. /^$/); # skip header lines
http://xrl.us/jgdj
* "rindex" clarification * Yitzchak Scott-Thoennes posted a mini-patch
to make clear the "rindex" description at pod/perlfunc.pod.
http://xrl.us/jgdk
* Differences from Perl6 * Robin Houston posted a doc patch against
pod/perlsyn.pod explaining the differences between the recently
introduced "given"/"when" and the corresponding Perl 6 constructs.
Applied as change #26537.
http://xrl.us/jgdm
*Bug in "File::Temp" Docs* In RT ticket #38127, pm noticed an
imprecision in "File::Temp" documentation, namely, when using the
object interface one must use "new File::Temp(TEMPLATE => $template)"
to constrain the generated filenames. Rafael Garcia-Suarez agreed and
applied a corresponding patch as change 26753.
http://xrl.us/jgdn
* perlmodlib missing "Pod::Perldoc"? * Yitzchak Scott-Thoennes missed
"Pod::Perldoc" not being listed in perlmodlib, even though most
"Pod::Perldoc::*" were there. Rafael Garcia-Suarez noted it was
because Perldoc.pm had no POD. How ironic, repeating Yitzchak's words.
http://xrl.us/jgdo
Robust "Pod::Simple::Search"
"Pod::Simple::Search" assumed that case-preserved package and pod
names could be constructed from filenames, which is not always true,
on OSes with non-case-preserving filesystems like VMS. To remedy this
situation, Craig A. Berry wrote a patch to make it work.
http://xrl.us/jgdp
Tels and "gv_*" Issues
Tels had been quite busy this end of year and started some long
threads. You have to read them if "gv_*" issues are your plate.
What's up with C<$a = \$a>?
http://xrl.us/jgdq
Stack usage
http://xrl.us/jgdr
Perl_gv_fetchpv vs. gv_fetchpvn
http://xrl.us/jgds
gv_stashpvn() vs gv_stashpv()
http://xrl.us/jgdt
"Configure" Patches
H.Merijn Brand applied a patch by Jarkko Hietaniemi for making
Configure smarter with respect to char (un)signedness in Tru64. While
on this, Jarkko made a wish for Configure in 5.9.3: scan for
"snprintf()" and "vsnprintf()" in behalf of people doing XS work, and
for who "sv_*pvf*()" may be an overkill. Steve Peters implemented it
minus the necessary changes to Porting/Glossary.
Merijn notes Jarkko's patch
http://xrl.us/jgdu
Jarkko's tiny wish
http://xrl.us/jgdv
Teaching "B::Concise"
Last week, Nicholas Clark slimmed down constants, and taught
"Devel::Peek" to understand the new representation, giving sensible
information to the user. This week, Jim Cromie taught the new trick to
"B::Concise". In the meantime, Nicholas remembered how missing
constants are now prototyped with "()" so that the parsing of programs
doesn't change platform by platform based on what macros are present
locally.
Summary of the thread on optimized constants
http://xrl.us/jgdw
Jim tames B::Concise
http://xrl.us/jgdx
Perl5 Bug Summary
Perl RT had a count of 1510 open tickets at the last Monday of 2005
and the year started with 1514 bugs waiting to be squashed.
Robert Spier's summaries
http://xrl.us/jgdy
http://xrl.us/jgdz
Perl RT just now
http://rt.perl.org/rt3/NoAuth/perl5/Overview.html
In Brief
*The Year in Perl 2005* chromatic wrote a very nice summary of the
activity in Perl during 2005. It didn't go through the p5p mailing
list, but it was too good not to be mentioned.
http://www.oreillynet.com/pub/wlg/8894
* "timelocal" not reverse of "localtime" * Rafael Garcia-Suarez found
some time to take a look at the fix applied by Dave Rolsky to assure
the behavior of "timelocal" as reverse of "localtime": but it fails
now. I believe this went unnoticed.
Previous thread summary
http://xrl.us/jgd2
Rafael says oops!
http://xrl.us/jgd3
* "lc()" Failures with Latin-1 Chars * Daniel Richard G., in ticket
#37999, reported how certain accented letters in a word (using Latin-1
chars) were not being lowercased by "lc()", with some curiosities
involving "chop" and "chomp". Rafael Garcia-Suarez fixed it by
harmonizing code of "do_chomp()" and "do_chop()" (change #26431).
Daniel noticed that, if the string isn't modified via chomp/chop/etc.,
the accented letters stay as-is. To Rafael, it's just the documented
behavior if you don't use "locale".
http://xrl.us/jgd4
*Perl on Win64* Jan Dubois brought a patch to fix a bogus setting in
win32/config.vc64 which allowed (together other previous changes) to
get 100% success running the regression tests on Windows 2003 Server
64bit on AMD64. Hurray for Jan!
http://xrl.us/jgd5
* spare flag bits on "rv2cv" * Nicholas Clark wonders: any spare flag
bits left on the op "rv2cv"? And he answers himself: here is the
lowest bit of "op_private".
http://xrl.us/jgd6
* "Compress::Zlib" on VMS * Paul Marquess brought a patch to sort out
building on MVS, applied as change #26468.
http://xrl.us/jgd7
*Goodness propagated into eval* I know this has been mentioned in the
last summary, but Robin's work to guarantee propagation of
compile-hints ("%^H") and constant overloading into eval is awesome,
to steal Rafael's words. Try the following in perls pre-Robin and
blead to see the difference:
$ perl -Mbigint -e 'print eval "1+2"'
http://xrl.us/jgd8
*A Dependency Loop* Tom Horsley has a rite to install all the latest
stable perl stuff when year begins. Good habit! While doing this, he
found "libwww-perl-5.805" depends on "HTML-Parser-3.48" which turned
out to depend on "HTTP::Headers" which lives in "libwww-perl". As far
as I know, these are not core modules, but Gisle Aas, the author of
both, is always around. (This is RT ticket #38097.)
http://xrl.us/jgd9
*How not to Report a Problem* namit opened ticket #38122 to say he was
having problems with local settings. Yitzchak Scott-Thoennes guessed
the messages namit was seeing and pointed to *LOCALE PROBLEMS* in
perllocale manpage. Show us the code, said Steve Peters.
http://xrl.us/jgea
*False Matches with Bad utf-8* Sadahiro Tomoyuki announced the RT
ticket #37836 had been resolved by the change 26258 and generously
offered a further investigation.
http://xrl.us/jgeb
*Effects of Patch 26370* Andreas Koenig was biten by the weird state
of things after change 26370 where there can be files that one can
"use" but that perl cannot compile. Andreas mentioned as examples the
"Acme::Meta" distro and "Devel-Symdump-2.04" based on the former.
Rafael Garcia-Suarez reduced the problem to a shorter test case and
fixed the issue with change 26574, which made Andreas very happy,
releasing "Devel::Symdump" 2.05 out to the world.
http://xrl.us/jgec
*Beware Floating Point* stassats opened ticket #38120 to say about
oddities of perl printing numbers like '2.23999999999999' instead of
the prettier '2.24' equivalents. chromatic remembered floating point
math is subject to rounding error, in Perl and every other programming
language, and Ronald J. Kimball found the answer to be a FAQ which can
be found with perldoc -q 9999.
http://xrl.us/jged
* Parser Bug with '; sub f' * Lukas Mai, in RT ticket #38121, found
what he thinks to be a parser bug. Yet to be commented.
$ perl -c -e '; sub f'
syntax error at -e line 1, at EOF
-e had compilation errors.
http://xrl.us/jgee
About this summary
At last, after untying my Gordian knot, here's the first p5p summary
of 2006, written by Adriano Rodrigues Ferreira. When you least expect
it, the next one by David will be here as well for your enjoyment.
Information concerning bugs referenced in this summary (as #nnnnn) may
be viewed at http://rt.perl.org/rt3/Ticket/Display.html?id=nnnnn
Information concerning patches to maint or blead referenced in this
summary (as #nnnnn) may be viewed at
http://public.activestate.com/cgi-bin/perlbrowse?patch=nnnnn
Weekly summaries are published on http://use.perl.org/ and posted on a
mailing list, (subscription: [EMAIL PROTECTED]). The
archive is at http://dev.perl.org/perl5/list-summaries/. Corrections
and comments are welcome.
If you found this summary useful or enjoyable, please consider
contributing to the Perl Foundation to help support the development of
Perl.
