[gcc r13-6605] Fortran: fix bounds check for copying of class expressions [PR106945]

[Harald Anlauf <anlauf@gcc.gnu.org>]

https://gcc.gnu.org/g:2cf5f485e0351bb1faf46196a99e524688f3966e

commit r13-6605-g2cf5f485e0351bb1faf46196a99e524688f3966e
Author: Harald Anlauf <anlauf@gmx.de>
Date:   Sat Mar 11 15:37:37 2023 +0100

    Fortran: fix bounds check for copying of class expressions [PR106945]
    
    In the bounds check for copying of class expressions, the number of elements
    determined from a descriptor, returned as type gfc_array_index_type (i.e. a
    signed type), should be converted to the type of the passed element count,
    which is of type size_type_node (i.e. unsigned), for use in comparisons.
    
    gcc/fortran/ChangeLog:
    
            PR fortran/106945
            * trans-expr.cc (gfc_copy_class_to_class): Convert element counts in
            bounds check to common type for comparison.
    
    gcc/testsuite/ChangeLog:
    
            PR fortran/106945
            * gfortran.dg/pr106945.f90: New test.

Diff:
---
 gcc/fortran/trans-expr.cc              |  1 +
 gcc/testsuite/gfortran.dg/pr106945.f90 | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/gcc/fortran/trans-expr.cc b/gcc/fortran/trans-expr.cc
index 045c8b00b90..dcd39f46776 100644
--- a/gcc/fortran/trans-expr.cc
+++ b/gcc/fortran/trans-expr.cc
@@ -1531,6 +1531,7 @@ gfc_copy_class_to_class (tree from, tree to, tree nelems, bool unlimited)
 	    name = (const char *)(DECL_NAME (to)->identifier.id.str);
 
 	  from_len = gfc_conv_descriptor_size (from_data, 1);
+	  from_len = fold_convert (TREE_TYPE (orig_nelems), from_len);
 	  tmp = fold_build2_loc (input_location, NE_EXPR,
 				  logical_type_node, from_len, orig_nelems);
 	  msg = xasprintf ("Array bound mismatch for dimension %d "
diff --git a/gcc/testsuite/gfortran.dg/pr106945.f90 b/gcc/testsuite/gfortran.dg/pr106945.f90
new file mode 100644
index 00000000000..e760ca7d27f
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr106945.f90
@@ -0,0 +1,11 @@
+! { dg-do compile }
+! { dg-options "-fcoarray=single -fcheck=bounds -ftrapv" }
+! PR fortran/106945
+! Contributed by G. Steinmetz
+
+module m
+  implicit none
+  type t
+     class(*), allocatable :: a[:]
+  end type
+end