cp/
2004-11-14  Giovanni Bajo  <giovannibajo@gcc.gnu.org>

	PR c++/18354
	* typeck.c (build_unary_op) <CONVERT_EXPR, NEGATE_EXPR>: Unify code.
	Make sure the result is always a rvalue.

testsuite/
2004-11-14  Giovanni Bajo  <giovannibajo@gcc.gnu.org>

	PR c++/18354
	* g++.dg/template/nontype11.C: New test.


Index: typeck.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/typeck.c,v
retrieving revision 1.596
diff -c -3 -p -r1.596 typeck.c
*** typeck.c	11 Nov 2004 03:13:03 -0000	1.596
--- typeck.c	16 Nov 2004 01:27:38 -0000
*************** build_unary_op (enum tree_code code, tre
*** 3741,3766 ****
  
    switch (code)
      {
      case CONVERT_EXPR:
-       /* This is used for unary plus, because a CONVERT_EXPR
- 	 is enough to prevent anybody from looking inside for
- 	 associativity, but won't generate any code.  */
-       if (!(arg = build_expr_type_conversion
- 	    (WANT_ARITH | WANT_ENUM | WANT_POINTER, arg, true)))
- 	errstring = "wrong type argument to unary plus";
-       else
- 	{
- 	  if (!noconvert)
- 	    arg = default_conversion (arg);
- 	  arg = build1 (NON_LVALUE_EXPR, TREE_TYPE (arg), arg);
- 	}
-       break;
- 
      case NEGATE_EXPR:
!       if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
! 	errstring = "wrong type argument to unary minus";
!       else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
! 	arg = perform_integral_promotions (arg);
        break;
  
      case BIT_NOT_EXPR:
--- 3741,3769 ----
  
    switch (code)
      {
+     /* CONVERT_EXPR stands for unary plus in this context.  */
      case CONVERT_EXPR:
      case NEGATE_EXPR:
!       {
! 	int flags = WANT_ARITH | WANT_ENUM;
! 	/* Unary plus (but not unary minus) is allowed on pointers.  */
! 	if (code == CONVERT_EXPR)
! 	  flags |= WANT_POINTER;
! 	if (!(arg = build_expr_type_conversion (flags, arg, true)))
! 	  errstring = (code == NEGATE_EXPR
! 		      ? "wrong type argument to unary minus"
! 		      : "wrong type argument to unary plus");
! 	else
! 	  {
! 	    if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
! 	      arg = perform_integral_promotions (arg);
! 
! 	    /* Make sure the result is not a lvalue: an unary plus or minus
! 	       expression is always a rvalue.  */
! 	    if (real_lvalue_p (arg))
! 	      arg = build1 (NON_LVALUE_EXPR, TREE_TYPE (arg), arg);
! 	  }
!       }
        break;
  
      case BIT_NOT_EXPR:



// { dg-do compile }
// Origin: <fsm at robots dot ox dot ac dot uk>
// PR c++/18354: Unary plus should not be wrapped in NON_LVALUE_EXPR

template <int N>
struct X { };

void f()
{
  X< 1> a;
  X<-1> b;
  X<+1> c;
}