re PR c++/35773 (auto_ptr references don't convert)

PR c++/35773
        * cp/call.c (build_user_type_conversion_1): Represent second step of
        copy-init with an rvalue conversion.
        (convert_like_real) [ck_user]: Don't implicitly add it here.
        * g++.dg/overload/autoptr1.C: New.

From-SVN: r134398

gcc/cp/ChangeLog

@@ -1,3 +1,10 @@
+2008-04-17  Jason Merrill  <jason@redhat.com>
+
+	PR c++/35773
+	* call.c (build_user_type_conversion_1): Represent second step of 
+	copy-init with an rvalue conversion.
+	(convert_like_real) [ck_user]: Don't implicitly add it here.
+
 2008-04-15  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c/35751

gcc/cp/call.c

@@ -2634,7 +2634,22 @@ build_user_type_conversion_1 (tree totype, tree expr, int flags)
 				       flags);
 
       if (cand)
-	cand->second_conv = build_identity_conv (totype, NULL_TREE);
+	{
+	  cand->second_conv = build_identity_conv (totype, NULL_TREE);
+
+	  /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
+	     set, then this is copy-initialization.  In that case, "The
+	     result of the call is then used to direct-initialize the
+	     object that is the destination of the copy-initialization."
+	     [dcl.init]
+
+	     We represent this in the conversion sequence with an
+	     rvalue conversion, which means a constructor call.  */
+	  if (TREE_CODE (totype) != REFERENCE_TYPE
+	      && !(convflags & LOOKUP_NO_TEMP_BIND))
+	    cand->second_conv
+	      = build_conv (ck_rvalue, totype, cand->second_conv);
+	}
     }
 
   if (conv_fns)
@@ -2686,6 +2701,20 @@ build_user_type_conversion_1 (tree totype, tree expr, int flags)
 				       0,
 				       /*c_cast_p=*/false, convflags);
 
+	      /* If LOOKUP_NO_TEMP_BIND isn't set, then this is
+		 copy-initialization.  In that case, "The result of the
+		 call is then used to direct-initialize the object that is
+		 the destination of the copy-initialization."  [dcl.init]
+
+		 We represent this in the conversion sequence with an
+		 rvalue conversion, which means a constructor call.  But
+		 don't add a second rvalue conversion if there's already
+		 one there.  Which there really shouldn't be, but it's
+		 harmless since we'd add it here anyway. */
+	      if (ics && MAYBE_CLASS_TYPE_P (totype) && ics->kind != ck_rvalue
+		  && !(convflags & LOOKUP_NO_TEMP_BIND))
+		ics = build_conv (ck_rvalue, totype, ics);
+
 	      cand->second_conv = ics;
 
 	      if (!ics)
@@ -4425,38 +4454,6 @@ convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
 	if (DECL_CONSTRUCTOR_P (convfn))
 	  expr = build_cplus_new (totype, expr);
 
-	/* The result of the call is then used to direct-initialize the object
-	   that is the destination of the copy-initialization.  [dcl.init]
-
-	   Note that this step is not reflected in the conversion sequence;
-	   it affects the semantics when we actually perform the
-	   conversion, but is not considered during overload resolution.
-
-	   If the target is a class, that means call a ctor.  */
-	if (MAYBE_CLASS_TYPE_P (totype)
-	    && (inner >= 0 || !lvalue_p (expr)))
-	  {
-	    expr = (build_temp
-		    (expr, totype,
-		     /* Core issue 84, now a DR, says that we don't
-			allow UDCs for these args (which deliberately
-			breaks copy-init of an auto_ptr<Base> from an
-			auto_ptr<Derived>).  */
-		     LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING|LOOKUP_NO_CONVERSION,
-		     &diagnostic_fn));
-
-	    if (diagnostic_fn && (complain & tf_error))
-	      {
-		if (fn)
-		  diagnostic_fn
-		    ("  initializing argument %P of %qD from result of %qD",
-		     argnum, fn, convfn);
-		else
-		 diagnostic_fn
-		   ("  initializing temporary from result of %qD",  convfn);
-	      }
-	    expr = build_cplus_new (totype, expr);
-	  }
 	return expr;
       }
     case ck_identity:
@@ -4518,7 +4515,8 @@ convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
       flags = LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING;
       if (convs->user_conv_p)
 	/* This conversion is being done in the context of a user-defined
-	   conversion, so don't allow any more.  */
+	   conversion (i.e. the second step of copy-initialization), so
+	   don't allow any more.  */
 	flags |= LOOKUP_NO_CONVERSION;
       expr = build_temp (expr, totype, flags, &diagnostic_fn);
       if (diagnostic_fn && fn)

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2008-04-17  Jason Merrill  <jason@redhat.com>
+
+	PR c++/35773
+	* g++.dg/overload/autoptr1.C: New.
+
 2008-04-17  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gnat.dg/alignment4.adb: New test.

gcc/testsuite/g++.dg/overload/autoptr1.C

@@ -0,0 +1,29 @@
+// PR c++/35773
+
+template< typename T >
+class auto_ptr
+{
+  struct auto_ptr_ref { };
+public:
+  auto_ptr(auto_ptr&);
+  auto_ptr(auto_ptr_ref);
+
+  operator auto_ptr_ref();
+};
+
+template< typename T >
+class reference_wrapper
+{
+public:
+  reference_wrapper(T& t);
+  operator T& () const;
+};
+
+struct X { };
+
+void f(auto_ptr< X >);
+
+void g(reference_wrapper< auto_ptr< X > > r)
+{
+  f(r);
+}