Open Watcom FORTRAN 77 Language Reference

Functions and Subroutines
has no type and must be associated with an asterisk. Arguments can be passed through more than one level
of procedure reference. In this case, valid association must exist at all intermediate levels as well as the last
level. Argument association is terminated upon the execution of a RETURN or END statement.
12.8.3.1 Length of Character Actual and Dummy Arguments
If a dummy argument is of type CHARACTER, the corresponding actual argument must also be of type
CHARACTER and the length of the dummy argument must be less than or equal to the length of the actual
argument. If the length of the dummy argument is len then the len leftmost characters of the actual
argument are associated with the dummy argument.
If a dummy argument of type CHARACTER is an array name, then the restriction on the length is on the
whole array and not for each array element. The length of an array element of the dummy argument may
be different from the length of the array element of the corresponding actual array, array element, or array
element substring, but the dummy array argument must not extend beyond the end of the associated actual
array.
12.8.3.2 Variables as Dummy Arguments
A dummy argument that is a variable may be associated with an actual argument that is a variable, array
element, substring or expression. Only if the actual argument is a variable, array element or substring can
the corresponding actual argument be redefined.
12.8.3.3 Arrays as Dummy Arguments
A dummy argument that is an array may be associated with an actual argument that is an array, array
element or array element substring. The number and size of the dimensions in the actual argument array
declarator may be different from the number and size of the dimensions in the dummy argument array
declarator.
If the actual argument is a non-character array name, then the size of the dummy argument array must not
exceed the size of the actual argument array. An element of the actual array becomes associated with the
element in the dummy array with the same subscript value. Association by array element of character
arrays exists only if the lengths of the array elements are the same. If their lengths are not the same, the
dummy and actual array elements will not consist of the same characters.
If the actual argument is a non-character array element name whose subscript value is asv the size of the
dummy argument array must not exceed the size of the actual argument array less asv - 1. Furthermore, the
dummy argument array element whose subscript value is dsv becomes associated with the actual argument
array element whose subscript value is asv + dsv - 1. Consider the following example.
Subprogram Arguments 279