call.c (joust): cp_pedwarn when using gnu extension concerning worst conversion sequences.

cp:
	* call.c (joust): cp_pedwarn when using gnu extension concerning
	worst conversion sequences.
testsuite:
	* g++.old-deja/g++.ext/overload1.C: New test.

From-SVN: r40182

gcc/cp/ChangeLog

+2001-03-02  Nathan Sidwell  <nathan@codesourcery.com>
+
+	* call.c (joust): cp_pedwarn when using gnu extension concerning
+	worst conversion sequences.
+
 2001-03-01  Zack Weinberg  <zackw@stanford.edu>
 
 	* decl.c: Replace all uses of 'boolean' with 'bool'.

gcc/cp/call.c

@@ -5312,6 +5312,7 @@ tweak:
   if (!pedantic)
     {
       int rank1 = IDENTITY_RANK, rank2 = IDENTITY_RANK;
+      struct z_candidate *w, *l;
 
       for (i = 0; i < len; ++i)
 	{
@@ -5320,11 +5321,22 @@ tweak:
 	  if (ICS_RANK (TREE_VEC_ELT (cand2->convs, i+off2)) > rank2)
 	    rank2 = ICS_RANK (TREE_VEC_ELT (cand2->convs, i+off2));
 	}
-
       if (rank1 < rank2)
-	return 1;
+	winner = 1, w = cand1, l = cand2;
       if (rank1 > rank2)
-	return -1;
+	winner = -1, w = cand2, l = cand1;
+      if (winner)
+        {
+	  if (warn)
+	    {
+	      cp_pedwarn ("choosing `%D' over `%D'", w->fn, l->fn);
+	      cp_pedwarn (
+"  because worst conversion for the former is better than worst conversion for the latter");
+	    }
+	  else
+	    add_warning (w, l);
+          return winner;
+        }
     }
 
   my_friendly_assert (!winner, 20010121);

gcc/testsuite/ChangeLog

+2001-03-02  Nathan Sidwell  <nathan@codesourcery.com>
+
+	* g++.old-deja/g++.ext/overload1.C: New test.
+
 2001-03-01  Nathan Sidwell  <nathan@codesourcery.com>
 
 	* g++.old-deja/g++.pt/using1.C: New test.

gcc/testsuite/g++.old-deja/g++.ext/overload1.C

+// Build don't link:
+// Special g++ Options: -fpermissive
+
+// Copyright (C) 2000 Free Software Foundation, Inc.
+// Contributed by Nathan Sidwell 28 Feb 2001 <nathan@codesourcery.com>
+
+// Make sure we warn about our overload extension about picking the
+// one with the least worse conversion
+
+struct X
+{
+  X (int);
+};
+void Foo (int, float, bool);
+void Foo (float, int, X);
+
+void Baz ()
+{
+  Foo (1, 1, 0);    // WARNING - least worse
+}