PR c++/32232

	* pt.c (resolve_overloaded_unification): Robustify.  Return a
	bool, not an int.
	(type_unification_real): Adjust accordingly.
	PR c++/32232
	* g++.dg/template/overload9.C: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@126435 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 60 insertions, 27 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index f22d5b7f429..2526a43ff03 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,10 @@
+2007-07-07  Mark Mitchell  <mark@codesourcery.com>
+
+	PR c++/32232
+	* pt.c (resolve_overloaded_unification): Robustify.  Return a
+	bool, not an int.
+	(type_unification_real): Adjust accordingly.
+
 2007-07-06  Richard Guenther  <rguenther@suse.de>
 
 	* init.c (build_new_1): Use the correct pointer type.
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index b822d951463..06e94e74fdb 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -97,8 +97,8 @@ static GTY(()) VEC(tree,gc) *canonical_template_parms;
 
 static void push_access_scope (tree);
 static void pop_access_scope (tree);
-static int resolve_overloaded_unification (tree, tree, tree, tree,
-					   unification_kind_t, int);
+static bool resolve_overloaded_unification (tree, tree, tree, tree,
+					    unification_kind_t, int);
 static int try_one_overload (tree, tree, tree, tree, tree,
 			     unification_kind_t, int, bool);
 static int unify (tree, tree, tree, tree, int);
@@ -11471,17 +11471,18 @@ type_unification_real (tree tparms,
 	  gcc_assert (TREE_TYPE (arg) != NULL_TREE);
 	  if (type_unknown_p (arg))
 	    {
-	      /* [temp.deduct.type] A template-argument can be deduced from
-		 a pointer to function or pointer to member function
-		 argument if the set of overloaded functions does not
-		 contain function templates and at most one of a set of
-		 overloaded functions provides a unique match.  */
+	      /* [temp.deduct.type] 
 
+	         A template-argument can be deduced from a pointer to
+		 function or pointer to member function argument if
+		 the set of overloaded functions does not contain
+		 function templates and at most one of a set of
+		 overloaded functions provides a unique match.  */
 	      if (resolve_overloaded_unification
-		  (tparms, targs, parm, arg, strict, sub_strict)
-		  != 0)
-		return 1;
-	      continue;
+		  (tparms, targs, parm, arg, strict, sub_strict))
+		continue;
+
+	      return 1;
 	    }
 	  arg_expr = arg;
 	  arg = unlowered_expr_type (arg);
@@ -11611,12 +11612,13 @@ type_unification_real (tree tparms,
   return 0;
 }
 
-/* Subroutine of type_unification_real.  Args are like the variables at the
-   call site.  ARG is an overloaded function (or template-id); we try
-   deducing template args from each of the overloads, and if only one
-   succeeds, we go with that.  Modifies TARGS and returns 0 on success.  */
+/* Subroutine of type_unification_real.  Args are like the variables
+   at the call site.  ARG is an overloaded function (or template-id);
+   we try deducing template args from each of the overloads, and if
+   only one succeeds, we go with that.  Modifies TARGS and returns
+   true on success.  */
 
-static int
+static bool
 resolve_overloaded_unification (tree tparms,
 				tree targs,
 				tree parm,
@@ -11675,16 +11677,17 @@ resolve_overloaded_unification (tree tparms,
 	    }
 	}
     }
+  else if (TREE_CODE (arg) != OVERLOAD
+	   && TREE_CODE (arg) != FUNCTION_DECL)
+    /* If ARG is, for example, "(0, &f)" then its type will be unknown
+       -- but the deduction does not succeed because the expression is
+       not just the function on its own.  */
+    return false;
   else
-    {
-      gcc_assert (TREE_CODE (arg) == OVERLOAD
-		  || TREE_CODE (arg) == FUNCTION_DECL);
-
-      for (; arg; arg = OVL_NEXT (arg))
-	good += try_one_overload (tparms, targs, tempargs, parm,
-				  TREE_TYPE (OVL_CURRENT (arg)),
-				  strict, sub_strict, addr_p);
-    }
+    for (; arg; arg = OVL_NEXT (arg))
+      good += try_one_overload (tparms, targs, tempargs, parm,
+				TREE_TYPE (OVL_CURRENT (arg)),
+				strict, sub_strict, addr_p);
 
   /* [temp.deduct.type] A template-argument can be deduced from a pointer
      to function or pointer to member function argument if the set of
@@ -11702,9 +11705,9 @@ resolve_overloaded_unification (tree tparms,
 	  TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
     }
   if (good)
-    return 0;
+    return true;
 
-  return 1;
+  return false;
 }
 
 /* Subroutine of resolve_overloaded_unification; does deduction for a single
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 20b4f95b06e..1f99b0068fc 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2007-07-07  Mark Mitchell  <mark@codesourcery.com>
+
+	PR c++/32232
+	* g++.dg/template/overload9.C: New test.
+
 2007-07-06  Daniel Berlin  <dberlin@dberlin.org>
 
 	* gcc.dg/tree-ssa/ssa-pre-17.c: New test.
diff --git a/gcc/testsuite/g++.dg/template/overload9.C b/gcc/testsuite/g++.dg/template/overload9.C
new file mode 100644
index 00000000000..bc73c41fc88
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/overload9.C
@@ -0,0 +1,18 @@
+// PR c++/32232
+
+template <typename T> struct A;
+template <typename T> struct B {};
+template <typename T> A<T>& operator<<(A<T>&, const B<T>&);
+
+template <typename T>
+struct A 
+{
+  A<T>& operator<<(A<T>& (*)(A<T>&)); // { dg-error "candidate" }
+};
+
+template <typename T> A<T>& foo(A<T>&);
+extern A<char> c;
+
+int main () {
+  c << (1, foo); // { dg-error "no match" }
+}