% LSR: http://lsr.di.unimi.it/LSR/Item?id=959
%=> http://lilypond.1069038.n5.nabble.com/Trill-Span-tc168639.html
% see also : http://lsr.di.unimi.it/LSR/Item?id=912

\relative c' {
  \time 4/4
  \clef treble
  \key c \major
  \override TrillSpanner.to-barline = ##t
  c2\startTrillSpan d4 e4 |
  f1
  \stopTrillSpan  |
  \revert TrillSpanner.to-barline
}