This Week on perl5-porters (27 January / 2 February 2003)
Hi all, here's your weekly dose of bug and fixes. Fold constants, send
signals, leak memory and introspect layers through this week's summary.
Constant folding in conditionals
The ?: conditional operator is optimized away by perl when the
condition is constant. This leads to a strange behavior, reported as bug
#20444 by Ton Hospel : the following construct
$_ = "foo"; print "foo" =~ (1 ? /foo/ : /bar/);
prints 1, because it's internally equivalent to :
$_ = "foo"; print "foo" =~ /foo/;
But in fact it should print nothing, as it should be equivalent to
$_ = "foo"; print "foo" =~ 1;
(this 1 being the value of /foo/, once evaluated.)
(of course, the proper way to mix regexps and ?: is to use qr//.)
http:[EMAIL PROTECTED]/msg91125.html
Signal handler configuration mess
Shevek reports (bug #20491) that assigning to $SIG{RTMIN} results in a
segfault on his linux system. After having inspecting his configuration,
it appears that Configure has assigned the signal number -1 to SIGRTMIN.
Why, we don't know (yet).
http:[EMAIL PROTECTED]/msg91194.html
Minor leak
Bill Bennett spotted a minor memory leak in the freeing of subroutines.
Dave Mitchell found that "one in every 64K ops will not be freed", due
to a hack used by the B::C compiler backend, and Paul Johnson provided a
patch.
http:[EMAIL PROTECTED]/msg91265.html
gcc locale-dependent messages
The makedepend script (that calculates dependencies between source
files) is fooled by gcc 3.2.1, when run under a french locale (and
probably other non-english locales as well). That's because makedepend
relies on the output of gcc to do its job. Nicholas Clark thinks "that
gcc generating programmatic output (not human output) that varies
depending on locale is a bug in gcc, and should be reported as such."
H.Merijn Brand proposes to use weaker patterns to match gcc output.
Rafael Garcia-Suarez proposes also to force the C locale in makedepend.
http:[EMAIL PROTECTED]/msg91453.html
Run-time access to ${^OPEN} values
Autrijus Tang wanted a way to know what default PerlIO layers are used
by a given block of Perl code. He proposed a patch to open.pm to store
this information on a package per package basis. But as the open pragma
is lexically scoped, this approach wasn't sufficient. Rafael pointed out
that it's available from the op tree and provided a naive C
implementation, which was quickly turned into a module, Devel::Hints, by
Autrijus.
Nick Ing-Simmons suggested that this runtime access to ${^OPEN} values
could be implemented in XS in the core, to be available in the open::
namespace.
http:[EMAIL PROTECTED]/msg91423.html
http://search.cpan.org/author/AUTRIJUS/Devel-Hints/
In brief
John Peacock released version.pm v0.28, that "now includes a subclass,
version::AlphaBeta, which demonstrates using alphanumeric version
strings, instead of strict numeric versions."
Jarkko Hietaniemi hopes someone will write the documents README.linux
and README.macosx. (We have already 37 README documents, that provide
notes and installation instructions specific to various platforms, but
those two popular OSes lack documentation.) John Adams volunteered for
OSX.
Rafael suggests to remove the obsolescent -u command-line switch. Ton
Hospel says that it could be reused as "the Unicode switch", but Jarkko
objects that this could create strange problems when different versions
of perl are used.
Stephane Payrard notices that IO::Handle can't be used together with
Inline::Files, at least on perl 5.8.0. The origin of the problem is
unknown (but patches are welcome).
Jarkko released a snapshot of the maintenance branch of perl 5.8.
About this summary
This summary was brought to you, as usual, by Rafael Garcia-Suarez.
Summaries are available on http://use.perl.org/ and/or via a mailing
list, which subscription address is [EMAIL PROTECTED]
Comments, corrections and additions are welcome.
