re PR fortran/20858 (NULL doesn't get its argument type (kind))

2006-02-05  Steven G. Kargl  <kargls@comcast.net>

PR fortran/20858
*decl.c (variable_decl): Improve error message.  Remove initialization
 typespec.  Wrap long line.
*expr.c (gfc_check_pointer_assign): Permit checking of type, kind type,
 and rank.
*simplify.c (gfc_simplify_null): Ensure type, kind type, and rank are set.

gfortran.dg/null_1.f90: New test.

From-SVN: r110845

gcc/fortran/ChangeLog

+2006-02-10  Steven G. Kargl  <kargls@comcast.net>
+
+	PR fortran/20858
+	*decl.c (variable_decl): Improve error message.  Remove initialization
+	typespec.  Wrap long line.
+	*expr.c (gfc_check_pointer_assign): Permit checking of type, kind type,
+	and rank.
+	*simplify.c (gfc_simplify_null): Ensure type, kind type, and rank
+	are set.
+
+
 2006-02-10  Tobias Schlter  <tobias.schlueter@physik.uni-muenchen.de>
 
 	PR fortran/14771

gcc/fortran/decl.c

@@ -1203,7 +1203,7 @@ variable_decl (int elem)
 	  m = gfc_match_null (&initializer);
 	  if (m == MATCH_NO)
 	    {
-	      gfc_error ("Pointer initialization requires a NULL at %C");
+	      gfc_error ("Pointer initialization requires a NULL() at %C");
 	      m = MATCH_ERROR;
 	    }
 
@@ -1218,8 +1218,6 @@ variable_decl (int elem)
 	  if (m != MATCH_YES)
 	    goto cleanup;
 
-	  initializer->ts = current_ts;
-
 	}
       else if (gfc_match_char ('=') == MATCH_YES)
 	{
@@ -1282,7 +1280,8 @@ variable_decl (int elem)
     t = add_init_expr_to_sym (name, &initializer, &var_locus);
   else
     {
-      if (current_ts.type == BT_DERIVED && !current_attr.pointer && !initializer)
+      if (current_ts.type == BT_DERIVED && !current_attr.pointer
+	  && !initializer)
 	initializer = gfc_default_initializer (&current_ts);
       t = build_struct (name, cl, &initializer, &as);
     }

gcc/fortran/expr.c

@@ -1984,7 +1984,7 @@ gfc_check_pointer_assign (gfc_expr * lvalue, gfc_expr * rvalue)
   /* If rvalue is a NULL() or NULLIFY, we're done. Otherwise the type,
      kind, etc for lvalue and rvalue must match, and rvalue must be a
      pure variable if we're in a pure function.  */
-  if (rvalue->expr_type == EXPR_NULL)
+  if (rvalue->expr_type == EXPR_NULL && rvalue->ts.type == BT_UNKNOWN)
     return SUCCESS;
 
   if (!gfc_compare_types (&lvalue->ts, &rvalue->ts))
@@ -2001,6 +2001,17 @@ gfc_check_pointer_assign (gfc_expr * lvalue, gfc_expr * rvalue)
       return FAILURE;
     }
 
+  if (lvalue->rank != rvalue->rank)
+    {
+      gfc_error ("Different ranks in pointer assignment at %L",
+		  &lvalue->where);
+      return FAILURE;
+    }
+
+  /* Now punt if we are dealing with a NULLIFY(X) or X = NULL(X).  */
+  if (rvalue->expr_type == EXPR_NULL)
+    return SUCCESS;
+
   if (lvalue->ts.type == BT_CHARACTER
 	&& lvalue->ts.cl->length && rvalue->ts.cl->length
 	&& abs (gfc_dep_compare_expr (lvalue->ts.cl->length,
@@ -2025,13 +2036,6 @@ gfc_check_pointer_assign (gfc_expr * lvalue, gfc_expr * rvalue)
 		 "procedure at %L", &rvalue->where);
     }
 
-  if (lvalue->rank != rvalue->rank)
-    {
-      gfc_error ("Unequal ranks %d and %d in pointer assignment at %L", 
-		 lvalue->rank, rvalue->rank, &rvalue->where);
-      return FAILURE;
-    }
-
   if (gfc_has_vector_index (rvalue))
     {
       gfc_error ("Pointer assignment with vector subscript "

gcc/fortran/simplify.c

@@ -2528,16 +2528,14 @@ gfc_simplify_null (gfc_expr * mold)
 {
   gfc_expr *result;
 
-  result = gfc_get_expr ();
-  result->expr_type = EXPR_NULL;
-
   if (mold == NULL)
-    result->ts.type = BT_UNKNOWN;
-  else
     {
-      result->ts = mold->ts;
-      result->where = mold->where;
+      result = gfc_get_expr ();
+      result->ts.type = BT_UNKNOWN;
     }
+  else
+    result = gfc_copy_expr (mold);
+  result->expr_type = EXPR_NULL;
 
   return result;
 }

gcc/testsuite/ChangeLog

+2006-02-10  Steven G. Kargl  <kargls@comcast.net>
+
+	gfortran.dg/null_1.f90: New test.
+
 2006-02-10  Tobias Schlter  <tobias.schlueter@physik.uni-muenchen.de>
 
 	PR fortran/14771

gcc/testsuite/gfortran.dg/null_1.f90

+! { dg-do compile }
+! PR fortran/20858
+! If we have "x = null(i)", then "null()" acquires the type, kind type,
+! and rank of i and these need to match those of x.
+program null_1
+   integer, parameter :: sp = kind(1.e0), dp = kind(1.d0)
+   integer,  pointer :: i => null()
+   real(sp), pointer :: x => null()
+   real(dp), pointer :: y => null()
+   real(sp), pointer :: z(:) => null()
+   x => null(i)     ! { dg-error "types in pointer assignment" }
+   x => null(y)     ! { dg-error "types in pointer assignment" }
+   z => null(i)     ! { dg-error "types in pointer assignment" }
+   z => null(y)     ! { dg-error "types in pointer assignment" }
+   x => null(z)     ! { dg-error "ranks in pointer assignment" }
+   z => null(x)     ! { dg-error "ranks in pointer assignment" }
+   z => null(z)
+   nullify(i, x, y, z)
+end program null_1