develooper Front page | perl.perl5.porters | Postings from February 2003

This Week on perl5-porters (27 January / 2 February 2003) (resent)

From:
Rafael Garcia-Suarez
Date:
February 5, 2003 04:34
Subject:
This Week on perl5-porters (27 January / 2 February 2003) (resent)
Message ID:
20030205133432.530107b5.rgarciasuarez@free.fr
[I resend this week's summary to P5P. Apparently it was delivered to
perl5-summary but not to perl5-porters, for an unknown reason. Apologies
for duplicates.]

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://archive.develooper.com/perl5-porters@perl.org/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://archive.develooper.com/perl5-porters@perl.org/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://archive.develooper.com/perl5-porters@perl.org/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://archive.develooper.com/perl5-porters@perl.org/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://archive.develooper.com/perl5-porters@perl.org/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 perl5-summary-subscribe@perl.org.
  Comments, corrections and additions are welcome.



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