[gcc r15-7826] Fortran: Add view convert to pointer assign when only pointer/alloc attr differs [PR104684]

[Andre Vehreschild]

https://gcc.gnu.org/g:705ae582d519f1230de3ec0d75a75e72341a674e

commit r15-7826-g705ae582d519f1230de3ec0d75a75e72341a674e
Author: Andre Vehreschild <vehre@gcc.gnu.org>
Date:   Tue Mar 4 17:06:31 2025 +0100

    Fortran: Add view convert to pointer assign when only pointer/alloc attr differs [PR104684]
    
            PR fortran/104684
    
    gcc/fortran/ChangeLog:
    
            * trans-array.cc (gfc_conv_expr_descriptor): Look at the
            lang-specific akind and do a view convert when only the akind
            attribute differs between pointer and allocatable array.
    
    gcc/testsuite/ChangeLog:
    
            * gfortran.dg/coarray/ptr_comp_6.f08: New test.

Diff:
---
 gcc/fortran/trans-array.cc                       | 10 +++++++++-
 gcc/testsuite/gfortran.dg/coarray/ptr_comp_6.f08 | 25 ++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/gcc/fortran/trans-array.cc b/gcc/fortran/trans-array.cc
index 6a00d26cb2f3..925030465ac3 100644
--- a/gcc/fortran/trans-array.cc
+++ b/gcc/fortran/trans-array.cc
@@ -8186,8 +8186,16 @@ gfc_conv_expr_descriptor (gfc_se *se, gfc_expr *expr)
 	{
 	  if (se->direct_byref && !se->byref_noassign)
 	    {
+	      struct lang_type *lhs_ls
+		= TYPE_LANG_SPECIFIC (TREE_TYPE (se->expr)),
+		*rhs_ls = TYPE_LANG_SPECIFIC (TREE_TYPE (desc));
+	      /* When only the array_kind differs, do a view_convert.  */
+	      tmp = lhs_ls && rhs_ls && lhs_ls->rank == rhs_ls->rank
+			&& lhs_ls->akind != rhs_ls->akind
+		      ? build1 (VIEW_CONVERT_EXPR, TREE_TYPE (se->expr), desc)
+		      : desc;
 	      /* Copy the descriptor for pointer assignments.  */
-	      gfc_add_modify (&se->pre, se->expr, desc);
+	      gfc_add_modify (&se->pre, se->expr, tmp);
 
 	      /* Add any offsets from subreferences.  */
 	      gfc_get_dataptr_offset (&se->pre, se->expr, desc, NULL_TREE,
diff --git a/gcc/testsuite/gfortran.dg/coarray/ptr_comp_6.f08 b/gcc/testsuite/gfortran.dg/coarray/ptr_comp_6.f08
new file mode 100644
index 000000000000..397a09bc8bc2
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/coarray/ptr_comp_6.f08
@@ -0,0 +1,25 @@
+!{ dg-do run }
+!
+! Contributed by Arseny Solokha  <asolokha@gmx.com>
+
+program pr104684
+  type :: index_map
+    integer, allocatable :: send_index(:)
+  end type
+  type(index_map) :: imap
+
+  imap%send_index = [5,4,3]
+  call sub(imap)
+contains
+  subroutine sub(this)
+    type(index_map), intent(inout), target :: this
+    type :: box
+      integer, pointer :: array(:)
+    end type
+    type(box), allocatable :: buffer[:]
+    allocate(buffer[*])
+    buffer%array => this%send_index
+    if (any(buffer%array /= [5,4,3])) stop 1    
+  end subroutine
+end program
+