If not P::RD, at least a more statefull parser rather than trying to do everything with just a single regex. Something like (and this is really rough and presumes curlies won't be on the same line as a declaration):

my $state = 'declaration';
my( $name, %data );
while( <> ) {
  if( $state eq 'declaration' ) {
    if( /CALCON\((.*?)\)/ ) {
      $name = $1;
      $state eq 'opencurly';
      next;
    }
  }
  if( $state eq 'opencurly' ) {
    $state = 'body' if /{/;
  }
  if( $state eq 'body' ) {
    if( /(\S+)\(.*?\)\s*$/ ) {
      $data{ $name }->{ $1 } = $2;
    }
    if( /\s*}\s*$/ ) {
      $state = 'declaration';
    }
  }
}
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