From: Jason Merrill <jason@redhat.com>
Date: Tue, 20 Aug 2013 12:59:24 +0000 (-0400)
Subject: re PR c++/58119 (Invalid ambiguous default type conversion with only a single invalid... 
X-Git-Tag: releases/gcc-4.7.4~525
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5e7d7fee28ec97343fcacfb254af14a420e2e3c2;p=thirdparty%2Fgcc.git

re PR c++/58119 (Invalid ambiguous default type conversion with only a single invalid conversion listed.)

	PR c++/58119
	* cp-tree.h (WILDCARD_TYPE_P): Split out from...
	(MAYBE_CLASS_TYPE_P): ...here.
	* cvt.c (build_expr_type_conversion): Don't complain about a
	template that can't match the desired type category.

From-SVN: r201881
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 5b5acd930699..247344281842 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,11 @@
+2013-08-20  Jason Merrill  <jason@redhat.com>
+
+	PR c++/58119
+	* cp-tree.h (WILDCARD_TYPE_P): Split out from...
+	(MAYBE_CLASS_TYPE_P): ...here.
+	* cvt.c (build_expr_type_conversion): Don't complain about a
+	template that can't match the desired type category.
+
 2012-12-03  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/54170
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 0c1601b474a4..b4fdda7999ad 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -1191,17 +1191,20 @@ enum languages { lang_c, lang_cplusplus, lang_java };
 /* The _DECL for this _TYPE.  */
 #define TYPE_MAIN_DECL(NODE) (TYPE_STUB_DECL (TYPE_MAIN_VARIANT (NODE)))
 
-/* Nonzero if T is a class (or struct or union) type.  Also nonzero
-   for template type parameters, typename types, and instantiated
-   template template parameters.  Keep these checks in ascending code
-   order.  */
-#define MAYBE_CLASS_TYPE_P(T)					\
+/* Nonzero if T is a type that could resolve to any kind of concrete type
+   at instantiation time.  */
+#define WILDCARD_TYPE_P(T)				\
   (TREE_CODE (T) == TEMPLATE_TYPE_PARM			\
    || TREE_CODE (T) == TYPENAME_TYPE			\
    || TREE_CODE (T) == TYPEOF_TYPE			\
    || TREE_CODE (T) == BOUND_TEMPLATE_TEMPLATE_PARM	\
-   || TREE_CODE (T) == DECLTYPE_TYPE			\
-   || CLASS_TYPE_P (T))
+   || TREE_CODE (T) == DECLTYPE_TYPE)
+
+/* Nonzero if T is a class (or struct or union) type.  Also nonzero
+   for template type parameters, typename types, and instantiated
+   template template parameters.  Keep these checks in ascending code
+   order.  */
+#define MAYBE_CLASS_TYPE_P(T) (WILDCARD_TYPE_P (T) || CLASS_TYPE_P (T))
 
 /* Set CLASS_TYPE_P for T to VAL.  T must be a class, struct, or
    union type.  */
diff --git a/gcc/cp/cvt.c b/gcc/cp/cvt.c
index d7ad05b1583c..fddba51cef77 100644
--- a/gcc/cp/cvt.c
+++ b/gcc/cp/cvt.c
@@ -1539,17 +1539,6 @@ build_expr_type_conversion (int desires, tree expr, bool complain)
       if (DECL_NONCONVERTING_P (cand))
 	continue;
 
-      if (TREE_CODE (cand) == TEMPLATE_DECL)
-	{
-	  if (complain)
-	    {
-	      error ("ambiguous default type conversion from %qT",
-		     basetype);
-	      error ("  candidate conversions include %qD", cand);
-	    }
-	  return error_mark_node;
-	}
-
       candidate = non_reference (TREE_TYPE (TREE_TYPE (cand)));
 
       switch (TREE_CODE (candidate))
@@ -1583,11 +1572,23 @@ build_expr_type_conversion (int desires, tree expr, bool complain)
 	  break;
 
 	default:
+	  /* A wildcard could be instantiated to match any desired
+	     type, but we can't deduce the template argument.  */
+	  if (WILDCARD_TYPE_P (candidate))
+	    win = true;
 	  break;
 	}
 
       if (win)
 	{
+	  if (TREE_CODE (cand) == TEMPLATE_DECL)
+	    {
+	      if (complain)
+		error ("default type conversion can't deduce template"
+		       " argument for %qD", cand);
+	      return error_mark_node;
+	    }
+
 	  if (winner)
 	    {
 	      if (complain)
diff --git a/gcc/testsuite/g++.dg/template/delete2.C b/gcc/testsuite/g++.dg/template/delete2.C
new file mode 100644
index 000000000000..b6ab380c9f9d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/delete2.C
@@ -0,0 +1,26 @@
+// PR c++/58119
+
+template <class T>
+struct A
+{
+  operator T*();
+  template <class U>
+  operator A<U>();
+};
+
+template <class T>
+struct B
+{
+  operator T*();
+  template <class U>
+  operator A<U>*();
+};
+
+int main()
+{
+  A<int> a;
+  delete a;
+
+  B<int> b;
+  delete b;			// { dg-error "template|delete" }
+}