* c-exp.y: Add new rule for resolving method overloads.

* eval.c (make_params): New function.
	(free_param_types): New function.
	(evaluate_subexp_standard): Pass expect_type to value_aggregate_elt.
	Handle case TYPE_INSTANCE.
	(evaluate_subexp_for_address): Pass expect_type to value_aggregate_elt.
	* expression.h (enum exp_opcode): Add TYPE_INSTANCE.
	(compare_parameters): Add declaration.
	* parse.c (operator_length_standard): Add TYPE_INSTANCE.
	* valops.c (value_aggregate_elt): Add new expect_type parameter.
	Pass expect_type to value_struct_elt_for_reference.
	(value_struct_elt_for_reference): Add expect_type parameter and use
	compare_parameters.
	Check for overload matches with and without artificial parameters.
	Skip artificial methods.
	(compare_parameters): New function.
	* value.h (value_aggregate_elt): Add new expect_type parameter.

gdb/valops.c

@@ -2536,8 +2536,8 @@ check_field (struct type *type, const char *name)
    the comment before value_struct_elt_for_reference.  */
 
 struct value *
-value_aggregate_elt (struct type *curtype,
-		     char *name, int want_address,
+value_aggregate_elt (struct type *curtype, char *name,
+		     struct type *expect_type, int want_address,
 		     enum noside noside)
 {
   switch (TYPE_CODE (curtype))
@@ -2545,7 +2545,7 @@ value_aggregate_elt (struct type *curtype,
     case TYPE_CODE_STRUCT:
     case TYPE_CODE_UNION:
       return value_struct_elt_for_reference (curtype, 0, curtype, 
-					     name, NULL,
+					     name, expect_type,
 					     want_address, noside);
     case TYPE_CODE_NAMESPACE:
       return value_namespace_elt (curtype, name, 
@@ -2556,6 +2556,57 @@ value_aggregate_elt (struct type *curtype,
     }
 }
 
+/* Compares the two method/function types T1 and T2 for "equality" 
+   with respect to the the methods' parameters.  If the types of the
+   two parameter lists are the same, returns 1; 0 otherwise.  This
+   comparison may ignore any artificial parameters in T1 if
+   SKIP_ARTIFICIAL is non-zero.  This function will ALWAYS skip
+   the first artificial parameter in T1, assumed to be a 'this' pointer.
+
+   The type T2 is expected to have come from make_params (in eval.c).  */
+
+static int
+compare_parameters (struct type *t1, struct type *t2, int skip_artificial)
+{
+  int start = 0;
+
+  if (TYPE_FIELD_ARTIFICIAL (t1, 0))
+    ++start;
+
+  /* If skipping artificial fields, find the first real field
+     in T1. */
+  if (skip_artificial)
+    {
+      while (start < TYPE_NFIELDS (t1)
+	     && TYPE_FIELD_ARTIFICIAL (t1, start))
+	++start;
+    }
+
+  /* Now compare parameters */
+
+  /* Special case: a method taking void.  T1 will contain no
+     non-artificial fields, and T2 will contain TYPE_CODE_VOID.  */
+  if ((TYPE_NFIELDS (t1) - start) == 0 && TYPE_NFIELDS (t2) == 1
+      && TYPE_CODE (TYPE_FIELD_TYPE (t2, 0)) == TYPE_CODE_VOID)
+    return 1;
+
+  if ((TYPE_NFIELDS (t1) - start) == TYPE_NFIELDS (t2))
+    {
+      int i;
+      for (i = 0; i < TYPE_NFIELDS (t2); ++i)
+	{
+	  if (rank_one_type (TYPE_FIELD_TYPE (t1, start + i),
+			      TYPE_FIELD_TYPE (t2, i))
+	      != 0)
+	    return 0;
+	}
+
+      return 1;
+    }
+
+  return 0;
+}
+
 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
    return the address of this member as a "pointer to member" type.
    If INTYPE is non-null, then it will be the type of the member we
@@ -2633,23 +2684,46 @@ value_struct_elt_for_reference (struct type *domain, int offset,
 	}
       if (t_field_name && strcmp (t_field_name, name) == 0)
 	{
-	  int j = TYPE_FN_FIELDLIST_LENGTH (t, i);
+	  int j;
+	  int len = TYPE_FN_FIELDLIST_LENGTH (t, i);
 	  struct fn_field *f = TYPE_FN_FIELDLIST1 (t, i);
 
 	  check_stub_method_group (t, i);
 
-	  if (intype == 0 && j > 1)
-	    error (_("non-unique member `%s' requires type instantiation"), name);
 	  if (intype)
 	    {
-	      while (j--)
-		if (TYPE_FN_FIELD_TYPE (f, j) == intype)
-		  break;
-	      if (j < 0)
-		error (_("no member function matches that type instantiation"));
-	    }
+	      for (j = 0; j < len; ++j)
+		{
+		  if (compare_parameters (TYPE_FN_FIELD_TYPE (f, j), intype, 0)
+		      || compare_parameters (TYPE_FN_FIELD_TYPE (f, j), intype, 1))
+		    break;
+		}
+
+	      if (j == len)
+		error (_("no member function matches that type instantiation"));	    }
 	  else
-	    j = 0;
+	    {
+	      int ii;
+	      /* Skip artificial methods.  This is necessary if, for example,
+		 the user wants to "print subclass::subclass" with only
+		 one user-defined constructor.  There is no ambiguity in this
+		 case.  */
+	      for (ii = 0; ii < TYPE_FN_FIELDLIST_LENGTH (t, i);
+		   ++ii)
+		{
+		  if (TYPE_FN_FIELD_ARTIFICIAL (f, ii))
+		    --len;
+		}
+
+	      /* Desired method is ambiguous if more than one method is
+		 defined.  */
+	      if (len > 1)
+		error (_("non-unique member `%s' requires type instantiation"), name);
+
+	      /* This assumes, of course, that all artificial methods appear
+		 BEFORE any concrete methods.  */
+	      j = TYPE_FN_FIELDLIST_LENGTH (t, i) - 1;
+	    }
 
 	  if (TYPE_FN_FIELD_STATIC_P (f, j))
 	    {