PR c++/67876 - [6 Regression] ICE when compiling Firefox 38

gcc/cp
	* pt.c (convert_template_argument): Make sure number of tree
	operands is greater than zero before attempting to extract one.

gcc/testsuite/
	* g++.dg/pr67876.C: New test.

From-SVN: r230924

gcc/cp/ChangeLog

+2015-11-25  Martin Sebor  <msebor@redhat.com>
+
+	PR c++/67876
+	* pt.c (convert_template_argument): Make sure number of tree
+	operands is greater than zero before attempting to extract one.
+
 2015-11-25  Ryan Burn  <contact@rnburn.com>
 
 	PR c++/68434

gcc/cp/pt.c

@@ -7234,6 +7234,7 @@ convert_template_argument (tree parm,
           if (TREE_CODE (TREE_TYPE (inner)) == REFERENCE_TYPE
               && TREE_CODE (TREE_TYPE (TREE_TYPE (inner))) == FUNCTION_TYPE
               && TREE_CODE (TREE_TYPE (inner)) == REFERENCE_TYPE
+              && 0 < TREE_OPERAND_LENGTH (inner)
               && reject_gcc_builtin (TREE_OPERAND (inner, 0)))
               return error_mark_node;
         }

gcc/testsuite/ChangeLog

+2015-11-25  Martin Sebor  <msebor@redhat.com>
+
+	PR c++/67876
+	* g++.dg/pr67876.C: New test.
+
 2015-11-25  Aditya Kumar  <aditya.k7@samsung.com>
 	    Sebastian Pop  <s.pop@samsung.com>
 

gcc/testsuite/g++.dg/pr67876.C

+// PR c++/67876 - [6 Regression] ICE when compiling Firefox 38
+// Caused by a patch for c/66516 - missing diagnostic on taking
+// the address of a builtin function
+// { dg-do compile }
+
+template <class T, void (&F)(T*)>
+struct S { };
+
+extern void foo (int*);
+
+template <class T, void (&F)(T*)>
+void bar (S<T, F>&s) { }
+
+S<int, foo> s;
+
+void foobar (S<int, foo> &s) { bar (s); }
+// PR c++/67876 - [6 Regression] ICE when compiling Firefox 38
+// Caused by a patch for c/66516 - missing diagnostic on taking
+// the address of a builtin function
+// { dg-do compile }
+
+template <class T, void (&F)(T*)>
+struct S { };
+
+extern void foo (int*);
+
+template <class T, void (&F)(T*)>
+void bar (S<T, F>&s) { }
+
+S<int, foo> s;
+
+void foobar (S<int, foo> &s) { bar (s); }