question: private void convertError ( CharBuffer buf , int line ) { String srcFilename = null ; int destLine = 0 ; int srcLine = 0 ; int srcTailLine = Integer . MAX_VALUE ; for ( int i = 0 ; i < _lines . size ( ) ; i ++ ) { Line map = ( Line ) _lines . get ( i ) ; if ( map . _dstLine <= line && line <= map . getLastDestinationLine ( ) ) { srcFilename = map . _srcFilename ; destLine = map . _dstLine ; srcLine = map . getSourceLine ( line ) ; break ; } } if ( srcFilename != null ) { } else if ( _lines . size ( ) > 0 ) srcFilename = ( ( Line ) _lines . get ( 0 ) ) . _srcFilename ; else srcFilename = "" ; buf . append ( srcFilename ) ; if ( line >= 0 ) { buf . append ( ":" ) ; buf . append ( srcLine + ( line - destLine ) ) ; } }
target:  Maps a destination line to an error location.