C++: add fixit for '>>' template error

gcc/cp/ChangeLog:
	* parser.c (cp_parser_enclosed_template_argument_list): Add fix-it
	hint to ">>" within nested template argument list error.

gcc/testsuite/ChangeLog:
	* g++.dg/template/double-greater-than-fixit.C: New test case.

From-SVN: r239873

gcc/cp/ChangeLog

 2016-08-30  David Malcolm  <dmalcolm@redhat.com>
 
+	* parser.c (cp_parser_enclosed_template_argument_list): Add fix-it
+	hint to ">>" within nested template argument list error.
+
+2016-08-30  David Malcolm  <dmalcolm@redhat.com>
+
 	* name-lookup.c (suggest_alternatives_for): Use add_fixit_replace
 	rather than add_fixit_misspelled_id.
 	* parser.c (cp_parser_diagnose_invalid_type_name): Likewise.

gcc/cp/parser.c

@@ -26342,8 +26342,10 @@ cp_parser_enclosed_template_argument_list (cp_parser* parser)
 	    global source location is still on the token before the
 	    '>>', so we need to say explicitly where we want it.  */
 	  cp_token *token = cp_lexer_peek_token (parser->lexer);
-	  error_at (token->location, "%<>>%> should be %<> >%> "
-		    "within a nested template argument list");
+	  gcc_rich_location richloc (token->location);
+	  richloc.add_fixit_replace ("> >");
+	  error_at_rich_loc (&richloc, "%<>>%> should be %<> >%> "
+			     "within a nested template argument list");
 
 	  token->type = CPP_GREATER;
 	}

gcc/testsuite/ChangeLog

+2016-08-30  David Malcolm  <dmalcolm@redhat.com>
+
+	* g++.dg/template/double-greater-than-fixit.C: New test case.
+
 2016-08-30  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gnat.dg/opt57.ad[sb]: New test.

gcc/testsuite/g++.dg/template/double-greater-than-fixit.C

+/* { dg-options "-fdiagnostics-show-caret -std=c++98" } */
+template <typename T>
+struct foo {};
+
+foo<foo<int>> i; // { dg-error "12: .>>. should be .> >. within a nested template argument list" }
+/* { dg-begin-multiline-output "" }
+ foo<foo<int>> i;
+            ^~
+            > >
+   { dg-end-multiline-output "" } */