C++ PATCH for Re: eg++ confusion with template argument

[Mark Mitchell]

This patch fixes a problem whereby default arguments were tricking us
into not recognizing constant declarations as constant.

-- 
Mark Mitchell 			mark@markmitchell.com
Mark Mitchell Consulting	http://www.markmitchell.com

1998-10-16  Mark Mitchell  <mark@markmitchell.com>

	* pt.c (for_each_template_parm): Don't examine uninstantiated
	default arguments.

Index: testsuite/g++.old-deja/g++.pt/defarg5.C
===================================================================
RCS file: defarg5.C
diff -N defarg5.C
*** /dev/null	Mon Dec 31 20:00:00 1979
--- defarg5.C	Fri Oct 16 13:02:23 1998
***************
*** 0 ****
--- 1,24 ----
+ // Build don't link:
+ 
+ template <int dim>
+ class Point {
+   public:
+     Point (Point<dim> &);
+     Point<dim> & operator = (Point<dim> &);
+ };
+ 
+ 
+ 
+ template <int dim>
+ class bar{
+   public:
+     void foo (Point<dim> p = Point<dim>());
+ };
+ 
+ 
+ 
+ template <>
+ void bar<2>::foo (Point<2> p) {
+   const int dim = 2;
+   Point<dim> q = p;
+ };
Index: cp/pt.c
===================================================================
RCS file: /egcs/carton/cvsfiles/egcs/gcc/cp/pt.c,v
retrieving revision 1.215
diff -c -p -r1.215 pt.c
*** pt.c	1998/10/14 21:16:36	1.215
--- pt.c	1998/10/16 20:02:46
*************** for_each_template_parm (t, fn, data)
*** 3766,3787 ****
        return for_each_template_parm (TREE_VALUE
  				     (TYPE_TEMPLATE_INFO (t)),
  				     fn, data);
!     case FUNCTION_TYPE:
!       if (for_each_template_parm (TYPE_ARG_TYPES (t), fn, data))
  	return 1;
        return for_each_template_parm (TREE_TYPE (t), fn, data);
      case ARRAY_TYPE:
        if (for_each_template_parm (TYPE_DOMAIN (t), fn, data))
  	return 1;
        return for_each_template_parm (TREE_TYPE (t), fn, data);
      case OFFSET_TYPE:
        if (for_each_template_parm (TYPE_OFFSET_BASETYPE (t), fn, data))
- 	return 1;
-       return for_each_template_parm (TREE_TYPE (t), fn, data);
-     case METHOD_TYPE:
-       if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data))
- 	return 1;
-       if (for_each_template_parm (TYPE_ARG_TYPES (t), fn, data))
  	return 1;
        return for_each_template_parm (TREE_TYPE (t), fn, data);
  
--- 3766,3800 ----
        return for_each_template_parm (TREE_VALUE
  				     (TYPE_TEMPLATE_INFO (t)),
  				     fn, data);
!     case METHOD_TYPE:
!       if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data))
  	return 1;
+       /* Fall through.  */
+ 
+     case FUNCTION_TYPE:
+       /* Check the parameter types.  Since default arguments are not
+ 	 instantiated until they are needed, the TYPE_ARG_TYPES may
+ 	 contain expressions that involve template parameters.  But,
+ 	 no-one should be looking at them yet.  And, once they're
+ 	 instantiated, they don't contain template parameters, so
+ 	 there's no point in looking at them then, either.  */
+       {
+ 	tree parm;
+ 
+ 	for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
+ 	  if (for_each_template_parm (TREE_VALUE (parm), fn, data))
+ 	    return 1;
+       }
+ 
+       /* Check the return type, too.  */
        return for_each_template_parm (TREE_TYPE (t), fn, data);
+ 
      case ARRAY_TYPE:
        if (for_each_template_parm (TYPE_DOMAIN (t), fn, data))
  	return 1;
        return for_each_template_parm (TREE_TYPE (t), fn, data);
      case OFFSET_TYPE:
        if (for_each_template_parm (TYPE_OFFSET_BASETYPE (t), fn, data))
  	return 1;
        return for_each_template_parm (TREE_TYPE (t), fn, data);