Fortran] PR 92994 – add more ASSOCIATE checks

        PR fortran/92994
        * primary.c (gfc_match_rvalue): Add some flavor checks
        gfc_matching_procptr_assignment.
        * resolve.c (resolve_assoc_var): Add more checks for invalid targets.

        PR fortran/92994
        * gfortran.dg/associate_50.f90: Update dg-error.
        * gfortran.dg/associate_51.f90: New.

From-SVN: r279853

gcc/fortran/ChangeLog

+2020-01-03  Tobias Burnus  <tobias@codesourcery.com>
+
+	PR fortran/92994
+	* primary.c (gfc_match_rvalue): Add some flavor checks
+	gfc_matching_procptr_assignment.
+	* resolve.c (resolve_assoc_var): Add more checks for invalid targets.
+
 2020-01-02  Tobias Burnus  <tobias@codesourcery.com>
 
 	PR fortran/68020

gcc/fortran/primary.c

@@ -3447,7 +3447,19 @@ gfc_match_rvalue (gfc_expr **result)
     }
 
   if (gfc_matching_procptr_assignment)
-    goto procptr0;
+    {
+      /* It can be a procedure or a derived-type procedure or a not-yet-known
+	 type.  */
+      if (sym->attr.flavor != FL_UNKNOWN
+	  && sym->attr.flavor != FL_PROCEDURE
+	  && sym->attr.flavor != FL_PARAMETER
+	  && sym->attr.flavor != FL_VARIABLE)
+	{
+	  gfc_error ("Symbol at %C is not appropriate for an expression");
+	  return MATCH_ERROR;
+	}
+      goto procptr0;
+    }
 
   if (sym->attr.function || sym->attr.external || sym->attr.intrinsic)
     goto function0;

gcc/fortran/resolve.c

@@ -8836,9 +8836,20 @@ resolve_assoc_var (gfc_symbol* sym, bool resolve_target)
 
       gcc_assert (target->symtree);
       tsym = target->symtree->n.sym;
-      if (tsym->attr.flavor == FL_PROGRAM)
+
+      if (tsym->attr.subroutine
+	  || tsym->attr.external
+	  || (tsym->attr.function
+	      && (tsym->result != tsym || tsym->attr.recursive)))
 	{
-	  gfc_error ("Associating entity %qs at %L is a PROGRAM",
+	  gfc_error ("Associating entity %qs at %L is a procedure name",
+		     tsym->name, &target->where);
+	  return;
+	}
+
+      if (gfc_expr_attr (target).proc_pointer)
+	{
+	  gfc_error ("Associating entity %qs at %L is a procedure pointer",
 		     tsym->name, &target->where);
 	  return;
 	}
@@ -8851,6 +8862,12 @@ resolve_assoc_var (gfc_symbol* sym, bool resolve_target)
       if (is_subref_array (target))
 	sym->attr.subref_array_pointer = 1;
     }
+  else if (target->ts.type == BT_PROCEDURE)
+    {
+      gfc_error ("Associating selector-expression at %L yields a procedure",
+		 &target->where);
+      return;
+    }
 
   if (target->expr_type == EXPR_NULL)
     {

gcc/testsuite/ChangeLog

+2020-01-03  Tobias Burnus  <tobias@codesourcery.com>
+
+	PR fortran/92994
+	* gfortran.dg/associate_50.f90: Update dg-error.
+	* gfortran.dg/associate_51.f90: New.
+
 2020-01-03  Jakub Jelinek  <jakub@redhat.com>
 
 	PR fortran/68020

gcc/testsuite/gfortran.dg/associate_50.f90

@@ -3,6 +3,6 @@
 ! Test case by Gerhard Steinmetz.
 
 program p
-  associate (y => p) ! { dg-error "is a PROGRAM" }
-  end associate
+  associate (y => p) ! { dg-error "Invalid association target" }
+  end associate  ! { dg-error "Expecting END PROGRAM statement" }
 end program p

gcc/testsuite/gfortran.dg/associate_51.f90

+! { dg-do compile }
+!
+! PR fortran/92994
+!
+! Contributed by G. Steinmetz
+!
+recursive function f() result(z)
+  associate (y1 => f())
+  end associate
+  associate (y2 => f)  ! { dg-error "is a procedure name" }
+  end associate
+end
+
+recursive function f2()
+  associate (y1 => f2()) ! { dg-error "Invalid association target" }
+  end associate          ! { dg-error "Expecting END FUNCTION statement" }
+  associate (y2 => f2)   ! { dg-error "is a procedure name" }
+  end associate
+end
+
+subroutine p2
+  type t
+  end type
+  type(t) :: z = t()
+  associate (y => t)
+  end associate
+end
+
+subroutine p3
+  procedure() :: g
+  associate (y => g)  ! { dg-error "is a procedure name" }
+  end associate
+end
+
+subroutine p4
+  external :: g
+  associate (y => g)  ! { dg-error "is a procedure name" }
+  end associate
+end
+
+recursive subroutine s
+  associate (y => s)  ! { dg-error "is a procedure name" }
+  end associate
+end
+
+recursive subroutine s2
+   associate (y => (s2)) ! { dg-error "Associating selector-expression at .1. yields a procedure" }
+   end associate
+end
+
+program p
+   associate (y => (p)) ! { dg-error "Invalid association target" }
+   end associate ! { dg-error "Expecting END PROGRAM statement" }
+end