12.4.1 / C.9.5 : TARGET dummy/actual arguments & dangling pointers

From: Joost VandeVondele (jv244_at_cam.ac.uk)
Date: 08/20/04 

Date: 20 Aug 2004 07:00:17 -0700

Hi,

below is a testcase for an issue that is confusing me. In the
following code:

 INTEGER, POINTER :: data
 ALLOCATE(data)
 CALL wrap(data)
 write(*,*) ASSOCIATED(data)
CONTAINS
 SUBROUTINE wrap(data)
   INTEGER :: data
   CALL mytarget(data)
 END SUBROUTINE
 SUBROUTINE mytarget(data)
   INTEGER, TARGET :: data
 END SUBROUTINE
END

has the pointer data after the call to wrap become a dangling pointer,
and is a TARGET attribute in the wrap necessary in order to keep it
defined/associated ? It will of course print T on most compilers, but
does a good runtime checker need to complain 'ASSOCIATED function
argument is dangling pointer DATA'

Just in case, the relevant part of C.9.5 seems:
"When execution of a procedure completes, any pointer that remains
defined and that is associated with a dummy argument that has the
TARGET attribute and is either a scalar or an assumed-shape array,
remains associated with the corresponding actual argument if the
actual argument has the TARGET attribute ..."

Thanks,

Joost

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