Fortran] PR 92872 – Fix get_CFI_desc

        PR fortran/92872
        * trans-array.c (get_CFI_desc): Fix cond whether saved desc exists.

        PR fortran/92872
        * gfortran.dg/bind_c_optional-1.f90: New.

From-SVN: r279160

gcc/fortran/ChangeLog

+2019-12-10  Tobias Burnus  <tobias@codesourcery.com>
+
+	PR fortran/92872
+	* trans-array.c (get_CFI_desc): Fix cond whether saved desc exists.
+
 2019-12-09  David Malcolm  <dmalcolm@redhat.com>
 
 	* error.c (gfc_diagnostic_starter): Add pp_newline call before

gcc/fortran/trans-array.c

@@ -882,7 +882,7 @@ get_CFI_desc (gfc_symbol *sym, gfc_expr *expr,
   else
     tmp = sym->backend_decl;
 
-  if (tmp && DECL_LANG_SPECIFIC (tmp))
+  if (tmp && DECL_LANG_SPECIFIC (tmp) && GFC_DECL_SAVED_DESCRIPTOR (tmp))
     tmp = GFC_DECL_SAVED_DESCRIPTOR (tmp);
 
   *desc = tmp;

gcc/testsuite/ChangeLog

+2019-12-10  Tobias Burnus  <tobias@codesourcery.com>
+
+	PR fortran/92872
+	* gfortran.dg/bind_c_optional-1.f90: New.
+
 2019-12-10  Richard Sandiford  <richard.sandiford@arm.com>
 
 	* gcc.dg/lto/tag-1_0.c, gcc.dg/lto/tag-1_1.c: New test.

gcc/testsuite/gfortran.dg/bind_c_optional-1.f90

+! { dg-do run }
+!
+! PR fortran/92872
+!
+! Contributed by G. Steinmetz
+!
+module m
+contains
+subroutine s(x) bind(c)
+   integer, allocatable, optional :: x(:)
+   x = [1, 2, 3]
+end
+end
+
+use m
+integer, allocatable :: y(:)
+! NOTE: starting at 0, otherwise it will fail due to PR 92189
+allocate(y(0:2))
+y = [9, 8, 7]
+call s(y)
+if (any (y /= [1, 2, 3])) stop 1
+end