------- Comment #8 from pinskia at gcc dot gnu dot org 2006-04-04 23:40 ------- From http://www.sesp.cse.clrc.ac.uk/Publications/felib90_design/design/node6.html Because of the nature and implementation of optional arguments in Fortran 90/95 the head of most routines has a group of code dealing with optional arguments. For an optional argument arg1 it takes the form
! Dummy argument INTEGER, OPTIONAL :: arg1 ....... ! Local variables INTEGER :: larg1 ....... IF (PRESENT(arg1))THEN larg1 = arg1 ELSE larg1 = default_arg1 ENDIF where larg1 is the local variable associated with arg1. It should be note that arg1 cannot be referenced if it is not present. It may only be reference through the PRESENT intrinsic. So this would be undefined code. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27035
