The documentation says:

$hasargs is true if a new instance of @_ was set up for the frame.

And that's how it works: 

sub x1 { @_ = 'a'; &x2 }
sub x2 { my ($c) = @_; say $c, (caller 0)[4] }
x2('b');  # b1
x1();     # a

[download]

($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,

[download]

In reply to Re^2: parm#4 from caller == !"eval" ? by choroba
in thread Re: parm#4 from caller == !"eval" ? by perl-diddler

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