On 2023-08-25 Fr 16:49, Dagfinn Ilmari Mannsåker wrote:
Alvaro Herrera<alvhe...@alvh.no-ip.org> writes:
On 2023-Aug-10, Peter Eisentraut wrote:
I wanted to figure put if we can catch these more reliably, in the style of
-Werror. AFAICT, there is no way to automatically turn all warnings into
fatal errors. But there is a way to do it per script, by replacing
use warnings;
by
use warnings FATAL => 'all';
See attached patch to try it out.
BTW in case we do find that there's some unforeseen problem and we want
to roll back, it would be great to have a way to disable this without
having to edit every single Perl file again later. However, I didn't
find a way to do it -- I thought about creating a separate PgWarnings.pm
file that would do the "use warnings FATAL => 'all'" dance and which
every other Perl file would use or include; but couldn't make it work.
Maybe some Perl expert knows a good answer to this.
Like most pragmas (all-lower-case module names), `warnings` affects the
currently-compiling lexical scope, so to have a module like PgWarnings
inject it into the module that uses it, you'd call warnings->import in
its import method (which gets called when the `use PgWarnings;``
statement is compiled, e.g.:
package PgWarnings;
sub import {
warnings->import(FATAL => 'all');
}
I wouldn't bother with a whole module just for that, but if we have a
group of pragmas or modules we always want to enable/import and have the
ability to change this set without having to edit all the files, it's
quite common to have a ProjectName::Policy module that does that. For
example, to exclude warnings that are unsafe, pointless, or impossible
to fatalise (c.f.https://metacpan.org/pod/strictures#CATEGORY-SELECTIONS):
package PostgreSQL::Policy;
sub import {
strict->import;
warnings->import(
FATAL => 'all',
NONFATAL => qw(exec internal malloc recursion),
);
warnings->uniport(qw(once));
}
Now that we require Perl 5.14, we might want to consider enabling its
feature bundle as well, with:
feature->import(':5.14')
Although the only features of note that adds are:
- say: the `say` function, like `print` but appends a newline
- state: `state` variables, like `my` but only initialised the first
time the function they're in is called, and the value persists
between calls (like function-scoped `static` variables in C)
- unicode_strings: use unicode semantics for characters in the
128-255 range, regardless of internal representation
We'd probably have to modify the perlcritic rules to account for it. See
<https://metacpan.org/pod/Perl::Critic::Policy::TestingAndDebugging::RequireUseStrict>
and similarly for RequireUseWarnings. In any case, it seems a bit like
overkill.
Maybe the BEGIN block of each file can `eval` a new PgWarnings.pm that
emits the "use warnings" line?
That's ugly as sin, and thankfully not necessary.
Agreed.
cheers
andrew
--
Andrew Dunstan
EDB:https://www.enterprisedb.com
