expr.c (gfc_check_assign): Don't allow NULL as rhs in a non-pointer assignment.

fortran/
* expr.c (gfc_check_assign): Don't allow NULL as rhs in a
non-pointer assignment.

testsuite/
* gfortran.dg/pr15754.f90: Change annotations to dg-error.

From-SVN: r97740

gcc/fortran/ChangeLog

+2005-04-06  Tobias Schl"uter  <tobias.schlueter@physik.uni-muenchen.de>
+
+	* expr.c (gfc_check_assign): Don't allow NULL as rhs in a
+	non-pointer assignment.
+
 2005-04-05  Feng Wang  <fengwang@nudt.edu.cn>
 
 	PR fortran/15959

gcc/fortran/expr.c

@@ -1789,11 +1789,12 @@ gfc_check_assign (gfc_expr * lvalue, gfc_expr * rvalue, int conform)
       return FAILURE;
     }
 
-  /* This is a guaranteed segfault and possibly a typo: p = NULL()
-     instead of p => NULL()  */
-  if (rvalue->expr_type == EXPR_NULL)
-    gfc_warning ("NULL appears on right-hand side in assignment at %L",
-		 &rvalue->where);
+   if (rvalue->expr_type == EXPR_NULL)
+     {
+       gfc_error ("NULL appears on right-hand side in assignment at %L",
+		  &rvalue->where);
+       return FAILURE;
+     }
 
   /* This is possibly a typo: x = f() instead of x => f()  */
   if (gfc_option.warn_surprising 

gcc/testsuite/ChangeLog

+2005-04-06  Tobias Schl"uter  <tobias.schlueter@physik.uni-muenchen.de>
+
+	* gfortran.dg/pr15754.f90: Change annotations to dg-error.
+
 2005-04-06  Joseph S. Myers  <joseph@codesourcery.com>
 
 	* gcc.dg/weak/weak-12.c, g++.dg/ext/weak2.C: New tests.

gcc/testsuite/gfortran.dg/pr15754.f90

 ! we didn't give a warning if the RHS of an assignment was NULL
 ! { dg-do-compile }
 INTEGER, POINTER :: P
-I = NULL() ! { dg-warning "NULL appears" "Assignment non-pointer = NULL" }
-P = NULL() ! { dg-warning "NULL appears" "Assignment pointer = NULL" }
+I = NULL() ! { dg-error "NULL appears" "Assignment non-pointer = NULL" }
+P = NULL() ! { dg-error "NULL appears" "Assignment pointer = NULL" }
 P => NULL()
 END