[Bug fortran/71798] New: failure to finalise fortran temporary

[jonathan.hogg at stfc dot ac.uk]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71798

            Bug ID: 71798
           Summary: failure to finalise fortran temporary
           Product: gcc
           Version: 6.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jonathan.hogg at stfc dot ac.uk
  Target Milestone: ---

Created attachment 38855
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38855&action=edit
test case

Compiling and running the attached code we get:

$ gfortran-6 -o assign_final assign_final.f90 && ./assign_final 
 Creating            1
 Assigned            2           1

This seems like a missing finalisation on copy assignment?

1) One might expect there to be a move assignment, and to get the following
output:
   Creating 1       [created in-place for x]
   Finalised 1      [may not happen if final not called on exit from program?]

2) Or a copy assignment, and to get the following:
   Creating 1       [create as temporary]
   Assigned 2 1     [copy temporary to x]
   Finalised 1      [temporary destroyed]
   Finalised 2      [may not happen if final not called on exit from program?]

I note that the intel compiler gives the second sequence, minus cleanup on
exit.
$ ifort -o assign_final assign_final.f90 && ./assign_final 
 Creating            1
 Assigned            2           1
 Finalised            1

I'm using the following version of gfortran:
GNU Fortran (Ubuntu 6.1.1-3ubuntu11~14.04.1) 6.1.1 20160511