[Bug fortran/44709] New: BLOCK and GOTO/EXIT/CYCLE

["burnus at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

I think at least some of the following block-leaving statements are valid,
probably all. Besides some issues of the type 'rejects valid' there is a big
wrong-code question:

The allocatable objects need to be freed and derived types finalized when one
leaves the scope of the block. How to handle this? As the example shows, there
are many jump targets. Maybe one has to do something like

   if (cond)
      savelabel = L.1
      goto clean_up_and_jump

   goto end:
   clean_up_and_jump: 
     cleanup
     goto target
   end:
     cleanup

Or something similar...

Example:

outer: block
  doloop: do i = 1, 4
    inner: block
       integer, allocatable :: a
       allocate(a)
       a = i
        if(i == 1) cycle       ! (1) - wrong-code: no dealloc
        if(i == 2) exit        ! (2a)- wrong-code: no dealloc
        if(i == 2) exit doloop ! (2b)- rejects-valid: label not found
        if(i == 3) exit inner  ! (3) - PR 44602
        if(i == 4) exit outer  ! (4) - PR 44602
       if(i == 5) goto 111     ! (5) - wrong-code: no dealloc
    end block inner
  end do doloop
end block outer
111 continue
end


(1) and (5) is accepted by gfortran, (2) is only accepted without the label
("Name 'doloop' in EXIT statement at (1) is not a loop name"). (3) and (4) are
constructs not yet supported, cf. PR 44602.


-- 
           Summary: BLOCK and GOTO/EXIT/CYCLE
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Keywords: wrong-code, rejects-valid
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: burnus at gcc dot gnu dot org
OtherBugsDependingO 44602
             nThis:


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44709