re PR fortran/29642 (Fortran 2003: VALUE Attribute (call by value not call by reference for actual arguments))

2006-12-03  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/29642
	* trans-expr.c (gfc_conv_variable): A character expression with
	the VALUE attribute needs an address expression; otherwise all
	other expressions with this attribute must not be dereferenced.
	(gfc_conv_function_call): Pass expressions with the VALUE
	attribute by value, using gfc_conv_expr.
	* symbol.c (check_conflict): Add strings for INTENT OUT, INOUT
	and VALUE.  Apply all the constraints associated with the VALUE
	attribute.
	(gfc_add_value): New function.
	(gfc_copy_attr): Call it for VALUE attribute.
	* decl.c (match_attr_spec): Include the VALUE attribute.
	(gfc_match_value): New function.
	* dump-parse-tree.c (gfc_show_attr): Include VALUE.
	* gfortran.h : Add value to the symbol_attribute structure and
	add a prototype for gfc_add_value
	* module.c (mio_internal_string): Include AB_VALUE in enum.
	(attr_bits): Provide the VALUE string for it.
	(mio_symbol_attribute): Read or apply the VLUE attribute.
	* trans-types.c (gfc_sym_type): Variables with the VLAUE
	attribute are not passed by reference!
	* resolve.c (was_declared): Add value to those that return 1.
	(resolve_symbol): Value attribute requires dummy attribute.
	* match.h : Add prototype for gfc_match_public.
	* parse.c (decode_statement): Try to match a VALUE statement.


2006-12-03  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/29642
	* gfortran.dg/value_1.f90 : New test.
	* gfortran.dg/value_2.f90 : New test.
	* gfortran.dg/value_3.f90 : New test.
	* gfortran.dg/value_4.f90 : New test.
	* gfortran.dg/value_4.c : Called from value_4.f90.

From-SVN: r119461

1 files changed, 27 insertions, 14 deletions

diff --git a/gcc/fortran/trans-expr.c b/gcc/fortran/trans-expr.c
index d504043..3505236 100644
--- a/gcc/fortran/trans-expr.c
+++ b/gcc/fortran/trans-expr.c
@@ -447,15 +447,21 @@ gfc_conv_variable (gfc_se * se, gfc_expr * expr)
 	 separately.  */
       if (sym->ts.type == BT_CHARACTER)
 	{
-          /* Dereference character pointer dummy arguments
+	  /* Dereference character pointer dummy arguments
 	     or results.  */
 	  if ((sym->attr.pointer || sym->attr.allocatable)
 	      && (sym->attr.dummy
 		  || sym->attr.function
 		  || sym->attr.result))
 	    se->expr = build_fold_indirect_ref (se->expr);
+
+	  /* A character with VALUE attribute needs an address
+	     expression.  */
+	  if (sym->attr.value)
+	    se->expr = build_fold_addr_expr (se->expr);
+
 	}
-      else
+      else if (!sym->attr.value)
 	{
           /* Dereference non-character scalar dummy arguments.  */
 	  if (sym->attr.dummy && !sym->attr.dimension)
@@ -2005,19 +2011,26 @@ gfc_conv_function_call (gfc_se * se, gfc_symbol * sym,
 	  argss = gfc_walk_expr (e);
 
 	  if (argss == gfc_ss_terminator)
-            {
-	      gfc_conv_expr_reference (&parmse, e);
+	    {
 	      parm_kind = SCALAR;
-              if (fsym && fsym->attr.pointer
-		  && e->expr_type != EXPR_NULL)
-                {
-                  /* Scalar pointer dummy args require an extra level of
-		  indirection. The null pointer already contains
-		  this level of indirection.  */
-		  parm_kind = SCALAR_POINTER;
-                  parmse.expr = build_fold_addr_expr (parmse.expr);
-                }
-            }
+	      if (fsym && fsym->attr.value)
+		{
+		  gfc_conv_expr (&parmse, e);
+		}
+	      else
+		{
+		  gfc_conv_expr_reference (&parmse, e);
+		  if (fsym && fsym->attr.pointer
+			&& e->expr_type != EXPR_NULL)
+		    {
+		      /* Scalar pointer dummy args require an extra level of
+			 indirection. The null pointer already contains
+			 this level of indirection.  */
+		      parm_kind = SCALAR_POINTER;
+		      parmse.expr = build_fold_addr_expr (parmse.expr);
+		    }
+		}
+	    }
 	  else
 	    {
               /* If the procedure requires an explicit interface, the actual