Ugly Assumed-Size Arrays

The -fugly-assumed option enables the treatment of any array with a final dimension specified as 1 as an assumed-size array, as if * had been specified instead.

For example, DIMENSION X(1) is treated as if it had read DIMENSION X(*) if X is listed as a dummy argument in a preceding SUBROUTINE, FUNCTION, or ENTRY statement in the same program unit.

Use an explicit lower bound to avoid this interpretation. For example, DIMENSION X(1:1) is never treated as if it had read DIMENSION X(*) or DIMENSION X(1:*). Nor is DIMENSION X(2-1) affected by this option, since that kind of expression is unlikely to have been intended to designate an assumed-size array.

This option is used to prevent warnings being issued about apparent out-of-bounds reference such as X(2) = 99.

It also prevents the array from being used in contexts that disallow assumed-size arrays, such as PRINT *,X. In such cases, a diagnostic is generated and the source file is not compiled.

The construct affected by this option is used only in old code that pre-exists the widespread acceptance of adjustable and assumed-size arrays in the Fortran community.

Note: This option does not affect how DIMENSION X(1) is treated if X is listed as a dummy argument only after the DIMENSION statement (presumably in an ENTRY statement). For example, -fugly-assumed has no effect on the following program unit:

     SUBROUTINE X
     REAL A(1)
     RETURN
     ENTRY Y(A)
     PRINT *, A
     END