Checking ability of compilers to detect uninitialised variables

The program uninit_test.f90 contains a number of simple subroutines that check for various fortran compilers ability to detect uninitialised variables.

With gfortran use -ffpe-trap=zero,overflow,invalid -finit-real=snan -finit-derived

With Intel compilers (ifort and ifx) use -check all -init=snan -init=array

Derived types with allocation in subroutines match the style of CABLE code in the UM. ACCESS ESM1.5/6 uses pointers (case 14) while ACCESS-AM3 uses a mixture of pointers and allocatable components (cases 14 & 16).

In the table an X indicates that an error was raised.

Case	gfortran 14.2	ifort 2021.10.0	ifx 2025.0.4
1: Scalar in main	X	X	X
2: Static array in main	X	X	X
3: Allocatable array in main	_	X	X
4: Pointer array in main	_	X	_
5: Local scalar in a subroutine	X	X	X
6: Module scalar	X	X	X
7: Automatic array in subroutine	X	X	X
8: Array in subroutine with dimension from module parameter	X	X	X
9: Static module array	X	X	X
10: Allocatable module array	_	X	X
11: Pointer module array	_	X	_
12: Scalar component of a derived type	X	_	_
13: Pointer array component of derived type	_	X	_
14: Pointer array component of derived type (alloc in subroutine)	_	_	_
15: Allocatable array component of derived type	_	X	X
16: Allocatable array component of derived type (alloc in subroutine)	_	_	X