20 Jun 2015 1:35
#16480
Dear all
I have found several problems with array valued functions. They are probably my fault. Nevertheless I think the diagnosis of the compiler may be better.
This is the first example. It fails at runtime if compiled with /CHECKMATE depending on whether an unused variable N is passed to the function via USE or not
module global
integer::N=1
interface fun
function fun(A,B)
REAL,intent(in)::A(:),B(:)
REAL fun(size(A),size(B))
end function fun
end interface
end module
program bug6
use global,only:fun
REAL A(4),B(4,4)
A=(/1.,2.,3.,4./)
B=fun(A,A)
PRINT*,B
end program
function fun(A,B)
use global,only:N ! Crashes (integer overflow) due to this line if
!compiled with /CHECKMATE !!!!
implicit none
REAL,intent(in)::A(:),B(:)
REAL fun(size(A),size(B))
fun=5. ! the error message points to this line
end function fun
Probably the reference at N should be included in the interface too. In fact, this versión does not fail:
module Nmodule
integer::N=1
end module
module global
interface fun
function fun(A,B)
use Nmodule
REAL,intent(in)::A(:),B(:)
REAL fun(size(A),size(B))
end function fun
end interface
end module
program bug6fixed
use global,only:fun
REAL A(4),B(4,4)
A=(/1.,2.,3.,4./)
B=fun(A,A)
PRINT*,B
end program
function fun(A,B)
use Nmodule
implicit none
REAL,intent(in)::A(:),B(:)
REAL fun(size(A),size(B))
fun=5.
end function fun
Regards