Compiler option to warn about argument declarations of x(1) instead of x(*)

[Beliavsky]

@RonShepard

The x(*) syntax was introduced in f77, so early fortran for the first 20 years before that relied on the de facto x(1) convention to specify an array of unknown/arbitrary/unspecified length. The IBM library was developed in the 1960s, during that time.

Thanks for the clarification. Has it always been valid to declare an argument as x(n), where n is a procedure argument? If so, why did many of the pre-Fortran-77 programmers not do that?