[Fortran, Patch, Coarray, PR 37336] Fix crash in finalizer when derived type coarray is already freed.

[Andre Vehreschild <vehre@gmx.de>]

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Hi all,

attached patch fixes a crash in coarray programs when an allocatable derived
typed coarray was freed explicitly. The generated cleanup code did not take
into account, that the coarray may have been deallocated already. The patch
fixes this by moving the statements accessing components inside the derived type
into the block guard by its allocated check.

Regtested ok on f37/x86_64. Ok for master?

Regards,
	Andre
--
Andre Vehreschild * Email: vehre ad gmx dot de

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[-- Attachment #2: caf_finalizer_fix.patch --]
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diff --git a/gcc/fortran/trans-array.cc b/gcc/fortran/trans-array.cc
index e0fc8ebc46b..8e94a9a469f 100644
--- a/gcc/fortran/trans-array.cc
+++ b/gcc/fortran/trans-array.cc
@@ -9320,6 +9320,12 @@ structure_alloc_comps (gfc_symbol * der_type, tree decl, tree dest,
       gfc_add_expr_to_block (&fnblock, tmp);
     }

+  /* Still having a descriptor array of rank == 0 here, indicates an
+     allocatable coarrays.  Dereference it correctly.  */
+  if (GFC_DESCRIPTOR_TYPE_P (decl_type))
+    {
+      decl = build_fold_indirect_ref (gfc_conv_array_data (decl));
+    }
   /* Otherwise, act on the components or recursively call self to
      act on a chain of components.  */
   for (c = der_type->components; c; c = c->next)
@@ -11507,7 +11513,11 @@ gfc_trans_deferred_array (gfc_symbol * sym, gfc_wrapped_block * block)
     {
       int rank;
       rank = sym->as ? sym->as->rank : 0;
-      tmp = gfc_deallocate_alloc_comp (sym->ts.u.derived, descriptor, rank);
+      tmp = gfc_deallocate_alloc_comp (sym->ts.u.derived, descriptor, rank,
+				       (sym->attr.codimension
+					&& flag_coarray == GFC_FCOARRAY_LIB)
+				       ? GFC_STRUCTURE_CAF_MODE_IN_COARRAY
+				       : 0);
       gfc_add_expr_to_block (&cleanup, tmp);
     }

@@ -11521,9 +11531,11 @@ gfc_trans_deferred_array (gfc_symbol * sym, gfc_wrapped_block * block)
 					NULL_TREE, NULL_TREE, true, e,
 					sym->attr.codimension
 					? GFC_CAF_COARRAY_DEREGISTER
-					: GFC_CAF_COARRAY_NOCOARRAY);
+					: GFC_CAF_COARRAY_NOCOARRAY,
+					NULL_TREE, gfc_finish_block (&cleanup));
       if (e)
 	gfc_free_expr (e);
+      gfc_init_block (&cleanup);
       gfc_add_expr_to_block (&cleanup, tmp);
     }

diff --git a/gcc/testsuite/gfortran.dg/coarray/alloc_comp_6.f90 b/gcc/testsuite/gfortran.dg/coarray/alloc_comp_6.f90
new file mode 100644
index 00000000000..e8a74db2c18
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/coarray/alloc_comp_6.f90
@@ -0,0 +1,29 @@
+! { dg-do run }
+
+program alloc_comp_6
+
+  implicit none
+
+  type :: foo
+    real :: x
+    integer, allocatable :: y(:)
+  end type
+
+  call check()
+
+contains
+
+  subroutine check()
+    block
+      type(foo), allocatable :: example[:] ! needs to be a coarray
+
+      allocate(example[*])
+      allocate(example%y(10))
+      example%x = 3.4
+      example%y = 4
+
+      deallocate(example)
+    end block  ! example%y shall not be accessed here by the finalizer,
+               ! because example is already deallocated
+  end subroutine check
+end program alloc_comp_6

[-- Attachment #3: caf_finalizer_fix.clog --]
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    Fortran: Free alloc. comp. in allocated coarrays only.

    When freeing allocatable components of an allocatable coarray, add
    a check that the coarray is still allocated, before accessing the
    components.

    This patch adds to PR fortran/37336, but does not fix it completely.

    gcc/fortran/ChangeLog:
            PR fortran/37336
            * trans-array.cc (structure_alloc_comps): Deref coarray.
            (gfc_trans_deferred_array): Add freeing of components after
            check for allocated coarray.

    gcc/testsuite/ChangeLog:
            PR fortran/37336
            * gfortran.dg/coarray/alloc_comp_6.f90: New test.