Is there some tool (or compile flag) that can detect problematic aliasing in Fortran code either during compilation or at run time? I see gfortran has -Waliasing, but that only detects the most egregious case (e.g. call whatever(x,x), but not call whatever(x(1),x(1))). Intel's ifort has -fno-alias, but apparently that just means the compiled code may give different results. Consider a code like this:
program main
implicit none
real :: x(100)
integer :: i
do i=1,size(x)
x(i) = i
end do
call sub(100,x(1:100),x(1:100))
contains
subroutine sub(n,a,b)
implicit none
integer, intent(in) :: n
real, intent(in) :: a(n)
real, intent(out) :: b(n)
b(:) = a(:)
end subroutine sub
end program main
I don't get any kind of warning (compiling or running), due to using the same memory addresses (x(1:100)) for both dummy arguments (a and b), where one of them is modified, which as far as I understand is forbidden by the standard.