This month on perl5-porters - August 2006
"Insistent rumors claim that we used to have Perl compilable with C++
-- I doubt it a bit, given the kind of problems I found when doing
this latest cleanup work." -- Jarkko Hietaniemi, having now found a
new wall against which to bang his head.
Topics of Interest
Perl 5.9.4 is out
Rafael Garcia-Suarez posted the first draft of the delta that
explained all the new goodies in the latest development release of
Perl, 5.9.4.
perl594delta
http://xrl.us/rny2
He made a number of changes based on feedback received.
perl594delta (take two)
http://xrl.us/rny3
And after a second round of feedback, managed to push the tarball out
the hatch.
Perl 5.9.4 is out
http://xrl.us/rny4
Define "PERL_NO_DEV_RANDOM" on Windows
Alex Davies noticed that perl attempts to look for /dev/urandom on
Win32 platforms, even though that file does not exist. And worse, you
can create it, thereby subverting Perl's randomness. Steve Peters
fixed that up.
Have you in fact got any cheese here at all?
http://xrl.us/rny5
IBM z/OS Unix source code fixes
Jarkko Hietaniemi wrapped up his heroic endeavour to merge the code
changes that IBM programmers made to a copy of Perl, *circa* 5.8.7, to
"blead". He announced he was stepping down, having left a couple of
parts of the patch unapplied, and explained why. He invited the IBM
programmers to continue the good work, to have Perl running on z/OS.
I hear the roar of a big machine
http://xrl.us/rny6
ops needed for "[]" and "{}"
Nicholas Clark discovered that a lot of work (lots of ops) are needed
to build a single lousy anonymous hash or array, and wondered if there
wasn't a more efficient way of of making one. He came up with a patch
to change the behaviour (bonus JFDI points to Nicholas) that
simultaneously slimmed down the op-tree, and doesn't break the test
suite. And naturally enough, he wanted to know whether people thought
this was a good idea.
Jim Cromie ran a few benchmarks and found some measurable
improvements.
Special ops
http://xrl.us/rny7
C99 is not compilable ... where?
Dropping in from Parrot, Chip Salzenberg wanted to know if any porters
knew of a platform far, far away that did not have a C99-capable
compiler.
Nicholas Clark mentioned "gcc", for starters. Andy Dougherty had some
good advice. Tony Cook pointed out that Microsoft don't seem very
interested in providing support for C99 features, unless they happen
to also be C++-compatible. Chip said some naughty words.
Just about everywhere else
http://xrl.us/rny8
Ponie has been put out to pasture
Jesse Vincent announced the end of the Ponie project, the migration of
the Perl 5 core to use the Parrot VM. A number of other techniques are
currently under development to have Perl 5 code running inside Perl 6,
and much good came out of the project in terms of clean-ups to the
code base.
They shoot horses, don't they?
http://xrl.us/rny9
Patches of Interest
Numerous small patches that were applied quietly without fuss, or
withdrawn by the author are not included in this section (it's big
enough as it is).
Patching for g++
Jarkko Hietaniemi checked in a large body of work to make the code
base compile with g++, the GNU C++ compiler.
First some g++ goodness for Tru64
http://xrl.us/rnza
And then a large patch for everyone, which nearly almost works, but
significant smoking will be required, if only to get the kinks ironed
out on some of the more common platforms.
http://xrl.us/rnzb
At this point, Jarkko rolled up a patch that succeeded as getting as
far as completing "make perl", although "x2p" and a few extensions
don't build. Steve Peters carried the baton and tidied up a few of the
easier modules, although a couple needed more thought.
http://xrl.us/rnzc
Jarkko then puzzled for a bit over how to get C linkage back out again
at the end of it, so that things would work as before. All this fuss
made him suspect that the source probably never was compilable with a
C++ compiler. Still, it might in the near future.
http://xrl.us/rnzd
He even managed to make "x2p" work.
doubleplusgood
http://xrl.us/rnze
Adding X<> tags to the documentation
Gabor Szabo delivered some patches to add X<> tags (for indexing) to
the core documentation and also snuck in a few stylistic changes while
no-one was looking (although it warranted a comment from Rafael).
File::Spec
http://xrl.us/rnzf
File::Basename
http://xrl.us/rnzg
perlvar
http://xrl.us/rnzh
More portability pitfalls for "perlhack"
Jarkko jotted down some more nuggets of wisdom acquired over the years
of doing battle with unfriendly compilers.
Here be dragons
http://xrl.us/rnzi
Silence format and comparison warnings in perlio.c, pp.c and regcomp.c
Robin Barker sent in a patch to silence many warnings of
signed/unsigned mismatches. Hooray! Applied.
ttys everywhere rejoiced
http://xrl.us/rnzj
Detecting bad /dev/nulls in "Configure"
Michael Cummings, from Gentoo, proposed a patch to make "Configure"
smarter about /dev/null, which may not always be configured correctly,
especially in chrooted environments, and by the time this causes a
problem, the build may already be quite some way down the track (and
thus the original cause of the error may be hard to diagnose. "Missing
Separator" errors may not seem crystal clear. Alexey Toptygin proposed
a tweak. A new patch was proposed. Unapplied.
Go directly to jail
http://xrl.us/rnzk
Watching the smoke signals
Smoke [5.9.4] 28730 FAIL(F) OSF1 V5.1 (EV6/4 cpu)
Things in lib/strict.t, lib/subs.t and t/run/fresh_perl.t seemed to be
going pear-shaped, but appeared to be a Heisenbug, since Jarkko wasn't
able to reproduce the errors manually.
http://xrl.us/rnzm
Smoke [5.9.4] 28736 FAIL(F) OSF1 V5.1 (EV6/4 cpu)
The pain persisted, so in the morning, Jarkko went to the ice-rink to
see if Dave Mitchell was around. Nicholas Clark made the connection to
the work on plugging leaks on unevaluable code, realising that that
may be causing problems here. Dave professed to not having many tuits
at the moment.
http://xrl.us/rnzn
New and old bugs from RT
*FILE{IO} does not behave like *FILE for "stat()" and "-X()" operators
(#8244)
Andy Dougherty revived an old bug that rose to the surface after a
Coverity scan. Rafael applied a quick fix.
http://xrl.us/rnzo
isa cache leaks into and out of "Safe" compartments (#39887)
Rafael asked for some test cases to draw the bug out into the open,
where it may more easily be stamped out.
Here buggy buggy
http://xrl.us/rnzp
"B::Deparse" double "do" (#40055)
Nicholas Clark wondered why "do{}" was deparsed as "do[ do{} }". Rick
Delaney provided the fix.
Deep do do
http://xrl.us/rnzq
UTF-8 keys in a tied hash cause warning (#40067)
Apparently not so much a bug as an unsupported feature.
It's always done that
http://xrl.us/rnzr
Memory leak in "Perl_newPMOP()" under "USE_ITHREADS" (#40077)
A discussion at Perlmonks revealed a ref-counting memory leak. No
takers.
http://xrl.us/rnzs
"perlfaq6" example is wrong: pull out lines between two patterns (#40084)
Max Maischein saw a flaw in a perlfaq example (where the two patterns
appear on different lines). The only fix he could think of involved
the arcane "m??". Rick Delaney offered a suggestion.
This question frequently asked?
http://xrl.us/rnzt
"Data::Dumper" with "Sortkeys" performs incomplete hash traversal (#40088)
Peter S. Shenkin provided a short snippet showing how a hash would be
not be completely traversed when the "Sortkeys" setting was active
(but the example *was* using "each" too). And it appears fixed in
5.8.8 anyway.
ENOTABUG, I assume
http://xrl.us/rnzu
File::Spec->case_tolerant() should return true on Cygwin (#40103)
G. Paulissen explained why this should be so. No takers.
http://xrl.us/rnzv
Using wrong case on module should warn (#40131)
Ben Tilly suggested that a warning should be issued if a module is
specified with incorrect capitalisation (on a filesystem with
case-insensitive semantics), reasoning that while "use Strict" might
work Here, it certainly won't work There.
Rafael noted that it turns out that there used to be such a warning,
but it was removed because of false positives.
Can't please everyone, all the time
http://xrl.us/rnzw
Perl 5 Errors on Windows 2003 (#40134)
Steve Hay awarded Subba Valisetty a golden crown for have filed the
most utterly useless bug report ever[TM]. Nicholas Clark was gentler,
and offered a pointer to a tutorial on how to file good bug reports.
Gong!
http://xrl.us/rnzx
Problem compiling perl 5.9.3 (#40141)
Pierre posted an excerpt of a failing compilation (pp_sys.c dying an
agonising death). Steve Hay asked for the output of the myconfig
script.
http://xrl.us/rnzy
"warnings::warnif" is sometimes ignored (#40144)
Wiles showed how to make "warnings::warnif" misbehave. No takers.
http://xrl.us/rnzz
"make" fails for perl 5.8.8 build on AIX5.3 (#40155)
Graham Stokes was having compiling 5.8.8 for AIX 5.3. Fortunately, he
was smart enough to supply myconfig. Steve Hay suggested using "ld"
(linker) from the GNU "binutils" package, rather than AIX's "ld". Andy
Dougherty also provided some advice on fixing locale warnings.
http://xrl.us/rnz3
"ccversion" fix for HP/UX (#40161)
An anonymous porter, possibly using the HP testdrive facility, filed a
fix for the HP/UX hints file. Applied.
http://xrl.us/rnz4
Problem "join()"ing threads (#40168)
Jonathan Geisler had a problem with threads, that Jerry D. Hedden
thought was probably fixed in the latest versions of "threads"
available on CPAN, and made a couple of suggestions to the code as
posted. Johnathon thanked him for the courtesy, and pointed out that
one of the snippets in question was lifted directly from "perlthrtut".
So that's the bug
http://xrl.us/rnz5
Unable to use "DProf" with threads (#40170)
Jonathan also joined the long list of people who had found limitations
with "Devel::DProf" in its current incarnation. Any takers?
A call to tuits
http://xrl.us/rnz6
Solaris: BEGIN and "exec", "fork", "system" or "open(|-,-|)" (#40190)
Gary Vollink discovered some Solaris wackiness, involving "use
warnings FATAL => 'all'", systems and/or backticks failing, and code
blocks then being evaluated and executed twice (when once would be
ample).
Nicholas Clark remembered this emergent behaviour cropping up in other
contexts, and thought that it was something to do with the Unix file
descriptor being diddled in the parent when the child dies.
Solaris: you are awful, but I like you
http://xrl.us/rnz7
"grep" autovivifies hash elements (#40194)
Marc Lehmann wondered why grepping a value against a hash key causes
the hash key to spring into existence. David Nicol thought that Marc
should have been using "exists". chromatic supplied a much clearer
pair of snippets to show what Marc was trying to get at. And yes, it's
quite counter-intuitive, broken, and nearly impossible to fix. David
still had trouble understanding, and Benjamin Carter (who writes from
a domain with a most excellent name) explained in more detail about
aliasing of $_ and the creation or not of hash keys.
Weird science
http://xrl.us/rnz8
Small typo in "perlxstut" man page (#40197)
Ville Koskinen explained the difference between ensure and insure.
Applied.
http://xrl.us/rnz9
UTF-16 and regular expressions causes compilation failure (#40203)
Ian Goodacre had a problem with regular expressions trying to match
characters coming out of a UTF-16-encoded file, specifically, an
unrecognised BOM 7061. No takers.
http://xrl.us/rn2a
"<>" as glob in scalar context and interpolated variables (#40213)
Dakkar filed a report about using "<>" as a glob in scalar context and
interpolated variables and how iterators were not reset and even added
a test case. No takers. Perhaps the fact that the test was tarred and
bzipped scared away potential fixers.
http://xrl.us/rn2b
"SelfLoader::croak" doesn't protect $@ from being clobbered by "require"
(#40216)
Bo Lindbergh filed a bug report so clear that Adriano Ferreira felt
that he could fix it. So he did. Applied.
http://xrl.us/rn2c
'reserved' warning not working (#40227)
Jerry D. Hedden discovered a problem with "use warnings 'reserved'"
not working correctly. Rafael made an oblique explanation as to why,
but I was not able to determine whether he was pointing out that the
error was in Jerry's test case or in Perl.
http://xrl.us/rn2d
They both seemed to understand each other, for an additional patch
later on got things sorted out.
http://xrl.us/rn2e
New hints file for MidnightBSD (#40239)
Lucas Holt tweaked the FreeBSD hints file, to derive a new hints file
that allows perl 5.8.8 to build successfully on MidnightBSD.
Unapplied.
Another platform added to the roster
http://xrl.us/rn2f
"PerlIO::scalar" doesn't know how to truncate (#40241)
Bo Lindbergh wanted "truncate" to work on strings. Rafael looked at
the implementation and saw that it only works for file handles at the
moment. Any takers?
Your chance for fame and glory
http://xrl.us/rn2g
"Math::BigInt" silently drops lib argument if not available (#40242)
You can import "Math::Bigint" and tell it to use an underlying library
to do the biginty calculations. But if you type the name incorrectly,
it silently loads a couple of default libraries and never complains
that anything is wrong. Andreas König thought this behaviour less than
desirable. He felt that the script should die, so that the programmer
could fix the error.
The problem is that if this was changed now, it might break programs
of people who were living happily in ignorance that their BigInt
calculations were not in fact using GMP or Pari as they had thought,
but rather the default Calc and Fastcalc libraries, simply because
they had accidently typed "Gimp" or "Paris".
Allen Smith felt that since this was the first time in four years that
someone had questioned the existing behaviour, it maybe wasn't so bad
after all. Tels offered a snippet of sanity checking boilerplate to do
what Andreas wanted.
You might find you get what you need
http://xrl.us/rn2h
Interesting variation on 'Out of memory' (#40243)
Andreas also posted a bug on rampant memory usage, that can be slimmed
down by using temporaries, which in turn allows the garbage collector
to fire off more readily, keeping consumption to a minimum.
http://xrl.us/rn2i
Perl5 Bug Summary
Around 21 new tickets were created this month, and alas, only 8 were
closed, bringing the current total to 1519. Hopefully after the summer
lull Steve will be able to get that figure down under 1500 again. And
if a couple of people pitched in to help, we could bring it down
lower, and faster.
Over to you
http://rt.perl.org/rt3/NoAuth/perl5/Overview.html
New Core Modules
* John Peacock uploaded version 0.67 of "version" to correct the
problem that Ovid spotted of version 0.000001 not being
understood.
http://xrl.us/rn2j
* Dave Rolsky synced "blead" with "Time::Local" version 1.13 from
CPAN.
http://xrl.us/rn2k
* "Module::Load" became part of the core distribution.
http://xrl.us/rn2m
* "Package::Constants" also became part of the core distribution.
http://xrl.us/rn2n
* A proposal was made to add "Locale::Maketext::Simple" to the core,
however, as far as I can see, it was not added. The fact that the
module is not licensed under the Artistic or GPL licenses (rather,
the MIT license), may have something to do with it.
http://xrl.us/rn2o
* "Module::Loaded" also made it into the core, but sparked off a
certain amount of debate as to whether it offered *enough*
functionality.
http://xrl.us/rn2p
* After having too much fun compiling perl with g++, Jarkko still
found time to release "Time::HiRes" version 1.88 to CPAN.
http://xrl.us/rn2q
In Brief
Rich Rauenzahn suggested a tweak to determining the HP-UX compiler
version in the Policy file.
http://xrl.us/rn2r
Nicholas Clark posted a long reply about the difference between
Python's and Perl's threads, and why Perl's threads are unlikely to
mesh nicely with a CORBA implementation.
http://xrl.us/rn2s
Brendan O'Dea, from the world of debian, wondered whether what was
wrong with "setlocale()" was an implementation or a documentation
problem.
http://xrl.us/rn2t
Alexandre Jousset wrote in to explain how to cross compile Perl for
the TomTom GO 910. Rafael updated a config file to take account of the
information.
Is that a telephone or an MP3 player?
http://xrl.us/rn2u
Even though he's left us, we are not forgotten. Andy Lester CC'ed the
list on his essay about why consting is good.
http://xrl.us/rn2v
Ben Morrow suggested adding all keywords to "perlfunc". And rather
just moaning about how nice it would be, actually sent in the patch
that documented a slew of things, like "can", "DESTROY" and so forth.
Unapplied, but it has certain merits.
http://xrl.us/rn2w
Marc Lehmann uncovered a way to make perl with
"-DPERL_DONT_CREATE_GVSV" dump core. Nicholas wasn't sure of the
reason.
http://xrl.us/rn2x
Gerard Goossen came up with a test case for a "substr" with lvalue
refcount increment bug, but no-one was sure what to do about it. At
least, Dave Mitchell didn't know.
http://xrl.us/rn2y
About this summary
This summary was written by David Landgren.
If you want a bookmarklet approach to viewing bugs and change reports,
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