After a compiler upgrade from 2015 to 2016 I got a linker error "unresolved external" when building in debug mode, but not in release mode. The .sln contains two projects, one exe and one dll. The exe does nothing but calling a single function from the dll. In the dll is a module containing global variables. One of those is used in another module as the size of an automatic array. This global variable is reported as an "unresolved external symbol MGLOBALS_mp_THEBAD" when linking the .exe-project (which does not have any reference to that variable). The error disappears when adding a "USE MGlobals" inside the function having the automatic array. Is there anything wrong with the code?
I´ve been able to reproduce this in a minimal example - here is the code:
MODULE MGlobals
IMPLICIT NONE
PRIVATE
SAVE
integer, public :: theGood, theBad, theUgly
END MODULE MGlobals
MODULE MyModule
USE MGlobals
IMPLICIT NONE
PRIVATE
SAVE
public doAny
CONTAINS
LOGICAL FUNCTION doAny()
doAny=doSome()
END FUNCTION doAny
LOGICAL FUNCTION doSome()
! use MGlobals !!!!! needed in ifort 2016 to make it work !!!!!
implicit none
real :: myArr(theBad) ! THIS usage triggers the error (is it not a valid specification expression?)
doSome = theBad.eq.66
END FUNCTION doSome
END MODULE MyModule
MODULE MFunctions
USE MyModule
IMPLICIT NONE
PRIVATE
SAVE
public :: Execute
CONTAINS
LOGICAL FUNCTION Execute()
!dec$attributes dllexport, alias: "Execute":: Execute
implicit none
write (*,*)'Executed!'
Execute=doAny()
end function Execute
END MODULE MFunctions
program ExeProject
use MFunctions
implicit none
logical res
res=Execute()
end program ExeProject
It seems that a full rebuild is necessary after each code change to have an effect.
Thanks for any insight on why this happens!
