Fortran: Fix some select rank issues [PR97694 and 97723].

2020-12-27  Paul Thomas  <pault@gcc.gnu.org>

gcc/fortran
	PR fortran/97694
	PR fortran/97723
	* check.c (allocatable_check): Select rank temporaries are
	permitted even though they are treated as associate variables.
	* resolve.c (gfc_resolve_code): Break on select rank as well as
	select type so that the block os resolved.
	* trans-stmt.c (trans_associate_var): Class associate variables
	that are optional dummies must use the backend_decl.

gcc/testsuite/
	PR fortran/97694
	PR fortran/97723
	* gfortran.dg/select_rank_5.f90: New test.

gcc/fortran/check.c

@@ -289,7 +289,7 @@ bin2real (gfc_expr *x, int kind)
 }
 
 
-/* Fortran 2018 treats a BOZ as simply a string of bits.  gfc_boz2real () 
+/* Fortran 2018 treats a BOZ as simply a string of bits.  gfc_boz2real ()
    converts the string into a REAL of the appropriate kind.  The treatment
    of the sign bit is processor dependent.  */
 
@@ -377,12 +377,12 @@ gfc_boz2real (gfc_expr *x, int kind)
 }
 
 
-/* Fortran 2018 treats a BOZ as simply a string of bits.  gfc_boz2int () 
+/* Fortran 2018 treats a BOZ as simply a string of bits.  gfc_boz2int ()
    converts the string into an INTEGER of the appropriate kind.  The
    treatment of the sign bit is processor dependent.  If the  converted
    value exceeds the range of the type, then wrap-around semantics are
    applied.  */
- 
+
 bool
 gfc_boz2int (gfc_expr *x, int kind)
 {
@@ -975,7 +975,8 @@ allocatable_check (gfc_expr *e, int n)
   symbol_attribute attr;
 
   attr = gfc_variable_attr (e, NULL);
-  if (!attr.allocatable || attr.associate_var)
+  if (!attr.allocatable
+     || (attr.associate_var && !attr.select_rank_temporary))
     {
       gfc_error ("%qs argument of %qs intrinsic at %L must be ALLOCATABLE",
 		 gfc_current_intrinsic_arg[n]->name, gfc_current_intrinsic,
@@ -3232,7 +3233,7 @@ gfc_check_intconv (gfc_expr *x)
       || strcmp (gfc_current_intrinsic, "long") == 0)
     {
       gfc_error ("%qs intrinsic subprogram at %L has been deprecated.  "
-		 "Use INT intrinsic subprogram.", gfc_current_intrinsic, 
+		 "Use INT intrinsic subprogram.", gfc_current_intrinsic,
 		 &x->where);
       return false;
     }
@@ -3965,7 +3966,7 @@ gfc_check_findloc (gfc_actual_arglist *ap)
   /* Check the kind of the characters argument match.  */
   if (a1 && v1 && a->ts.kind != v->ts.kind)
     goto incompat;
-	 
+
   d = ap->next->next->expr;
   m = ap->next->next->next->expr;
   k = ap->next->next->next->next->expr;

gcc/fortran/resolve.c

@@ -11776,8 +11776,9 @@ gfc_resolve_code (gfc_code *code, gfc_namespace *ns)
 	      gfc_resolve_omp_do_blocks (code, ns);
 	      break;
 	    case EXEC_SELECT_TYPE:
-	      /* Blocks are handled in resolve_select_type because we have
-		 to transform the SELECT TYPE into ASSOCIATE first.  */
+	    case EXEC_SELECT_RANK:
+	      /* Blocks are handled in resolve_select_type/rank because we
+		 have to transform the SELECT TYPE into ASSOCIATE first.  */
 	      break;
             case EXEC_DO_CONCURRENT:
 	      gfc_do_concurrent_flag = 1;

gcc/fortran/trans-stmt.c

@@ -1784,7 +1784,7 @@ trans_associate_var (gfc_symbol *sym, gfc_wrapped_block *block)
       if (e->ts.type == BT_CLASS)
 	{
 	  /* Go straight to the class data.  */
-	  if (sym2->attr.dummy)
+	  if (sym2->attr.dummy && !sym2->attr.optional)
 	    {
 	      class_decl = DECL_LANG_SPECIFIC (sym2->backend_decl) ?
 			   GFC_DECL_SAVED_DESCRIPTOR (sym2->backend_decl) :

gcc/testsuite/gfortran.dg/select_rank_5.f90

@@ -0,0 +1,44 @@
+! { dg-do run }
+!
+! Test the fixes for PR97723 and PR97694.
+!
+! Contributed by Martin  <mscfd@gmx.net>
+!
+module mod
+   implicit none
+   private
+   public cssel
+
+contains
+
+function cssel(x) result(s)
+   character(len=:), allocatable :: s
+   class(*), dimension(..), optional, intent(in) :: x
+   if (present(x)) then
+      select rank (x)
+      rank (0)
+         s = '0' ! PR97723: ‘assign’ at (1) is not a function
+                 ! PR97694: ICE in trans-stmt.c(trans_associate_var)
+      rank (1)
+         s = '1' ! PR97723: ‘assign’ at (1) is not a function
+      rank default
+         s = '?' ! PR97723: ‘assign’ at (1) is not a function
+      end select
+   else
+      s = '-'
+   end if
+end function cssel
+
+end module mod
+
+program classstar_rank
+   use mod
+   implicit none
+
+   integer :: x
+   real, dimension(1:3) :: y
+   logical, dimension(1:2,1:2) :: z
+
+   if (any ([cssel(x),cssel(y),cssel(z),cssel()] .ne. ['0','1','?','-'])) stop 1
+
+end program classstar_rank