In this week's p5p summary, some stories are continued, and new ones begin. Read about the safe signals, the recent support for assertions, and a load of fixes and of new bugs, waiting to be fixed.
My regular readers will remember that Jarkko Hietaniemi proposed two weeks ago to add a mechanism to optionally enable the pre-5.8 behavior of signals (known as unsafe signals since the latest incarnation of the perldelta man page advertised safe signals.) He proposed initially a new magic variable ${^SIGNAL_UNSAFE}. But this feature is intended to allow to write scripts portable across different perl versions, and the special variable syntax ${^FOO} produces a syntax error with perl 5.005xx and below. Several other proposals were suggested : $SIGNAL_UNSAFE, %SIGNAL_UNSAFE, $SIG{UNSAFEXXX} (that produces a warning with perl 5.6), $SIG::UNSAFE. Finally, Jarkko is going for an environment variable, $ENV{PERL_SIGNALS}.
http://archive.develooper.com/perl5-porters@perl.org/msg92113.html
http://archive.develooper.com/perl5-porters@perl.org/msg92443.html
As I briefly wrote last week, Salvador Fandiño's patch to add
assertions to perl is now in. Basically, assertions are defined as
subroutines with an:assertion attribute. In a perl program, a lexical
block is defined as potentially containing assertions via the
assertions pragma. Then, by executing the program with the -A
command-line switch, those assertion subroutines are activated (and thus
executed). It's possible to define different assertion groups and to
activate them separately. Note that assertions that are not activated are
optimized out during the compilation phase, and have no run-time impact on
performances.
A few more docs are needed for this new feature. Feedback on the API would also be much appreciated.
http://archive.develooper.com/perl5-porters@perl.org/msg92123.html
H. Merijn Brand, who has received another HP-UX machine, has set up smoke tests to determine whether Nicholas Clark's copy-on-write patches actually enhance perl's performance.
http://archive.develooper.com/perl5-porters@perl.org/msg92412.html
One of the thread tests was consistently failing of Johan Vromans' linux
smoke tests, due to differences in ps(1) output. This has been corrected
by making the test more liberal in what it accepts.
http://archive.develooper.com/perl5-porters@perl.org/msg92290.html
Jos Boumans' employer, XS4all, donated an x86 box to run smoke tests. Jos asked for advice on the OS he should install on it. Several proposals were reviewed ; finally this will be Darwin.
http://archive.develooper.com/perl5-porters@perl.org/msg92319.html
Jarkko hopes to get perl 5.8.1 RC1 in a month or so (but doesn't want to stick to a fixed date).
http://archive.develooper.com/perl5-porters@perl.org/msg92151.html
Philip Newton reported some limitations of B::Terse regarding threaded perls (bug #21261). This was fixed by Stephen McCamant who replaced B::Terse with a wrapper around B::Concise.
http://archive.develooper.com/perl5-porters@perl.org/msg92169.html
Chip Salzenberg modified the syntax of unpack() so that it defaults to
unpacking $_ if given only a template parameter.
http://archive.develooper.com/perl5-porters@perl.org/msg92209.html
Michael Schwern noticed that on Darwin, gcc is passed by default the
-Os optimization flag (optimize for size), which is set in
the Darwin hints file for Darwin 6.X and up. This is due to Apple's policy
for one part, and to the fact that the version of gcc bundled with earlier
versions of the OS were sub-optimal regarding size optimizations.
http://archive.develooper.com/perl5-porters@perl.org/msg92214.html
Andreas Koenig embedded a small perl script in the header file patchlevel.h, to allow people to add comments in it by doing simply
perl -x patchlevel.h 'comment'
http://archive.develooper.com/perl5-porters@perl.org/msg92246.html
Bug #21258, reported by Martin Ruderer, is about large lists causing
core dumps when used in a for loop (for example, 1 for ("") x 2147483516),
under some configurations.
http://archive.develooper.com/perl5-porters@perl.org/msg92168.html
Alex Efros reports (bug #21273) that a recursive FETCH on a tied hash may lead to a segfault.
http://archive.develooper.com/perl5-porters@perl.org/msg92223.html
Jarkko reports (bug #21321) that the construct local ${"FOO"} is not
allowed and produces the error message Can't localize through a
reference. But this construct is (or should be) equivalent to a simple
local $FOO. Rafael Garcia-Suarez provided a patch to allow to localize
variables given by a symbolic reference. Adrian Enache asked why local
$$ref couldn't work in any case (i.e. when $ref is a true scalar
reference).
http://archive.develooper.com/perl5-porters@perl.org/msg92357.html
Adrian Enache continues to fix loads of miscellaneous bugs.
This summary brought to you 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 and corrections are welcome.
Is there anywhere I can catch up on assertions? It seems like an interesting concept but, at this point, is very very blurry to me
Re:Assertions
rafael on 2003-02-26T12:31:24
Currently, the code is in bleadperl, and lacks documentation. If you want to play with assertions, you have to get bleadperl (probably via rsync(1) or via another method as described in perlhack(1)), look at lib/assertions.pm, and at t/comp/assertions.t and t/run/switch_A.t (the regression tests for assertions). Alternatively, look at changes 18727, 18739, and 18750 for the implementation of assertions. (More patches are waiting in the apply queue.)