IMHO what you suggested can be achieved by 
use warnings;
no warnings "uninitialized";

[download]
but actually this gave me an idea to use __WARN__ and caller() to check if the warning happened on a line with a debug call and hide those. 
use 5.010;
use strict;
use warnings;

my $x = 42;
my $y;

$SIG{__WARN__} = sub {
    my $warn = shift;
    my ($package, $filename, $line) = caller;
    if (open my $fh, '<', $filename) {
        my @lines = <$fh>;
        return if $lines[$line-1] =~ /debug\(/;
    }
    print $warn;
};

my $z = $x+$y;

debug("x=$x y=$y");

sub debug {
    say shift;
}

[download]
Though this will have a runtime impact we need to consider. Of course then we could cache the filename/rownumber pairs to reduce the cost. Thank you for the suggestion.

In reply to Re^4: use warnings and debug messages by szabgab
in thread use warnings and debug messages by szabgab

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