star-kind (PORT021)

Fix is sometimes available.

This rule is turned on by default.

What it does

Checks for non-standard kind specifiers such as int*4 or real*8

Why is this bad?

Types such as 'real8' or 'integer4' are not standard Fortran and should be avoided. For these cases, consider instead using 'real(real64)' or 'integer(int32)', where 'real64' and 'int32' may be found in the intrinsic module 'iso_fortran_env'. You may also wish to determine kinds using the built-in functions 'selected_real_kind' and 'selected_int_kind'.

Fixes to this rule are considered unsafe, as while dtype*N is generally understood to mean a dtype that occupied N bytes, this does not necessarily correspond to dtype(N), which is a dtype of 'kind' N. For example, the NAG compiler may be configured to use a sequential kind system in which real*8 corresponds to real(2)

In a future version, we hope to upgrade this to a safe fix by use of parameters in iso_fortran_env, as real*8 should always correspond to real(real64).