This Week on perl5-porters - 31 October-6 November 2005
This week sees consolidation on several fronts: mathoms, ops, env
handling, futimes, sort... plus the usual assortment of bug fixes and
enhancements.
Feedback from last week's summary
Steve Peters remembered the history of mathoms.c in p5p dated back to
2001 and not only June/July this year, when it came to life again.
Also, the Configure option which was anticipated were not ready yet at
the summary time, but it is now.
Steve Peters patches the summary
http://xrl.us/ib67
Concerning Cygwin, "unlink", Win32, Yitzchak Scott-Thoennes commented
that he was referring to the Cygwin DLL source code and not perl when
illustrating how "unlink" in Cygwin mapped to the Windows API.
Yitzchak Scott-Thoennes makes things clear
http://xrl.us/ib68
More mathoms.c fallout
The recent introduction of mathoms.c produced fallout in various
places this week
Gisle implements the Configure option
http://xrl.us/ib69
and shrinks the perl binary by 0.75%
http://xrl.us/ib7a
Getting C<do_exec> on Win32 back in order
http://xrl.us/ib7b
Getting C<perl.h> on VMS back in order
http://xrl.us/ib7c
More on "ExtUtils::Constant"
chromatic raised an eyebrow at Sébastien Aperghis-Tramoni's use of
indirect object notation (current best practices these days dictating
that one should say "Object->method" rather than "method Object".
Nicholas Clark discovered that the patch causes a bad failure in
"blead" due to dependency orderings, because somehow in "blead",
"FileHandle" now requires "IO::File" which is not yet available during
the build. Nicholas fixed it up by with some conditional "require"ing
in patch #25927.
The patch
http://xrl.us/ib7d
The patch to the patch
http://xrl.us/ib7e
Bring out yer dead (ops)
After running perl under "gcov", Nicholas noticed that about twenty
ops were never hit by the test suite. It could be expected that an op
like "pp_dump" (which exists solely to make perl dump core) would not
be covered by the test suite, but maybe some ops should (which Dave
Mitchell said was the case for "pp_regcmaybe" and provided a snippet
to prove it).
Maybe some are obsolete and could thus be chainsawed away. Rafael
Garcia-Suarez pointed out that a certain number of ops are required
during compilation, but are optimised away afterwards, and thus it
would be a non-trivial effort to truly get rid of them. Although he
thought that "pp_threadsv" and "pp_setstate" could probably be let go.
Rafael then noted that he had written some XS code in the past that
called some "pp_*" routines directly, and mentioned that he had
published a module on CPAN that lets you change the interpreter
runloop on the fly.
This led Nicholas to think about the possibility of making the runloop
deal with the handling of signals differently. That is, getting rid of
the current "PERL_ASYNC_CHECK()" ("safe signals") call in the runloop,
and merely switching to a runloop that knows how to deal with a
signal, when a signal is encountered.
Reported in ticket #37573
http://xrl.us/ib7f
Change your runloop
http://search.cpan.org/dist/Runops-Switch/lib/Runops/Switch.pm
Nick's second idea
http://xrl.us/ib7g
Andy's consting
Andy Lester consted more stuff, spotted a couple of chances to
simplify code, and dedicated the patch to Etta James:
The patch
http://xrl.us/ib7h
Etta James
http://www.etta-james.com/
... and dealt with perlio.c seperately because it's so hairy:
http://xrl.us/ib7i
Andy also posted the switches he's using for building perl under GCC
4.1.0 snapshots (using as many switches as possible to seek out
doubtful code constructs).
Bondage and discipline
http://xrl.us/ib7j
and also found a lovely trailing semi-colon-on-on-if bug in
"pp_ftrowned":
http://xrl.us/ib7k
and yet more consting
http://xrl.us/ib7m
and cleaning of the x2p directory
http://xrl.us/ib7n
DB_File patched to deal with Berkeley DB 4.4
Paul Marquess supplied a patch to get DB_File to run with the upcoming
4.4 release of Berkeley DB. Steve Peters applied the patch and
Yitzchak wondered whether it was important enough to make sure it made
its way into 5.8.8.
http://xrl.us/ib7o
Let the good futimes roll
Gisle Aas continued on the thread last week about using "futimes" on
platforms where it is available, noting that the MacOS X manpage says
that "utime" is obsolete and "utimes" should be used, but the Posix
manpage says that "utimes" is legacy, and "utime" should be used for
maximum portability. Sigh. Steve Peters and Gisle discussed the
problem of getting Configure to probe for this.
Also, Solaris 10 has a function called "futimesat", which does
everything, and more besides. (In case you were wondering, these
functions deal with setting the access and modification times for
files).
utime? utimes?
http://xrl.us/ib7p
Abe Timmerman patches configure.com
http://xrl.us/ib7q
sort/multicall patch in blead
Robin Houston's sort/multicall patch went into blead. Rafael noticed a
few puffs of smoke escape from the lab, and saw that one functionality
that the patch broke was the ability to empty the array *while you
sort it* and still retrieve the results afterwards. Since no-one was
really sure why anyone would want to do a thing like that, the test
was quietly dropped.
So don't try the following at home, because it's not going to work any
more:
@a = (1..10);
@b = sort { @a=(); ($a+1)<=>($b+1) } @a;
Nicholas was worried that the test was a guard to check for core
dumps, but perl wasn't dumping core, just sorting an array of
undefined elements (which seems to be the right behaviour under the
circumstances).
Paul Marquess found that "DB_File" revealed a couple of problems in
the patch, and these problems were fixed. Jim Cromie pitched in and
fixed a couple of other test errors.
Dave Mitchell had a couple of minor queries about the code but
basically liked it. The conversation went on between Robin and Dave
for a while. Robin summed it up best:
It's the usual perl internals story really: everything
depends on everything else in mysterious and undocumented
ways, and it's hard to make apparently innocent changes
without subtle breakage...
Starting from last week
http://xrl.us/ib7r
The patch applied
http://xrl.us/ib7s
Dave weighs in
http://xrl.us/ib7t
Compiling 5.8.7 with Visual Studio 2005
Joel Reed wrote in to say that he was having some difficulty in
compiling 5.8.7 with Microsoft's latest compiler, especially in the
area of "perlio" and related some very wacky symptoms. He also tried
5.9.2, and that didn't work, either. And unfortunately for Joel, he
was Warnocked.
http://xrl.us/ib7u
The prototype of "Perl_magic_clear_all_env"
Alan Burlison, in his quest to make the environment code a little less
icky, wanted to change the signature of the "Perl_magic_clear_all_env"
function. This would prevent memory leaks when one lets perl manage
the environment.
The main problem is whether or not this would break binary
compatibility. Steve Peters used the CPAN source code search and found
that no-one outside of core is using it, and thought that it is
unlikely that any other code does so, but the possibility cannot be
ruled out.
Alan was worried about platforms using different calling conventions
and decided that the best way forward would be to put the new smarts
in a new routine, and thereby not allow the possibility of breaking
binary compatibility.
Alan subsequently posted a patch to make use perl use "clearenv" on
platforms where it makes sense, and called for feedback on other
platforms such as MacOS, Symbian, VMS and Win32.
The question
http://xrl.us/ib7v
All hail gonzui
http://cpansearch.bulknews.net/
using clearenv
http://xrl.us/ib7w
A surprising segfault
Robin Houston was rather bemused by:
% perl -e 'map print(reverse), ("")x68'
Segmentation fault
and wondered why it was happening. Dave Mitchell promptly described
the problem and fixed it. Sadahiro Tomoyuki found that many other
"pp_*" functions exhibit similar behaviour and provided a patch to fix
them too. Tels wanted tests.
segfault
http://xrl.us/ib7x
How to kill perl
http://www.perlmonks.org/index.pl?node_id=505817
See perl say()
Steve Peters proposed a patch to bring Perl 6's "say()" to Perl 5.
(Which is roughly "print" with a "\n" tacked on). Robin Houston
pointed to a prior thread (and patch) on the issue, that was not well
received at the time. The main problem is one of backwards
compatibility: how do you deal with a program that has defined a
subroutine named "say"?
(The summariser recalls a thread on Perlmonks where someone suggested
using "-l" on the command line to get equivalent "say" functionality
with "print" and use "printf" (not necessarily with "%" args) to get
non-newline print behaviour).
This time
http://xrl.us/ib7y
Last time around
http://xrl.us/ib7z
New Core Module Releases
Andreas J. Koenig brought "CPAN.pm" up to version 1.76_60. (The _60
implies a beta version). Some of the new features include: plays
nicely with version.pm, support for "sudo", new commands, better error
messages and better handling of configuration variables.
Perl 5 Bug Summary
1520 open items, six items less that 2 weeks old have not been
responded to.
In brief
Jarkko added UIQ support to the Symbian port
http://xrl.us/ib72
Steven Schubiger cleared up the no-whitespace-before-semicolon
problems for pod files that needed it.
http://xrl.us/ib73
Jutta posted a bug report dealing with "sysread" in UTF-8 mode. When
Steve Peters opined that a little bit of code might help understand
the problem more easily, Jutta replied with a TCP server written in C
and a client written in Perl. What more could you wish for?
http://xrl.us/ib74
Alan Burlison was still wondering about the "malloc_wrap" compiler
warnings being produced. After discussing the issue with Nicholas, he
decided to add an explanation about the compiler warnings to the
README.solaris file.
http://xrl.us/ib75
Dan Dascalescu posted a bug report concerning "File::Glob", escaped
metacharacters and spaces in filenames. Steven Schubiger showed a
couple of ways to get around the problem.
http://xrl.us/ib76
Andreas J. Koenig took a stab at fixing bug #19049 (Incorrect $` after
replacement). Rafael applied it, and then backed it out after not
being able to solve the remaining problems himself. If someone else
wants to have a go...
http://xrl.us/ib77
Robin Houston noted that perlcall.pod documents problems that were
fixed way back in version 5.002, and fired up the chainsaw.
http://xrl.us/ib78
Anno Siegel posted an interesting bug:
my $str = 'aa';
$str &= 'a';
$str =~ /a+$/ or die;
This dies, and Anno says it shouldn't. No response for the moment.
http://xrl.us/ib79
About this summary
This summary was written by David Landgren.
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
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