[PR86823] retain deferred access checks from outside firewall

We used to preserve deferred access check along with resolved template
ids, but a tentative parsing firewall introduced additional layers of
deferred access checks, so that we don't preserve the checks we
want to any more.

This patch moves the deferred access checks from outside the firewall
into it.


From: Jason Merrill <jason@redhat.com>
for  gcc/cp/ChangeLog

	PR c++/86823
	* parser.c (cp_parser_template_id): Rearrange deferred access
	checks into the firewall.

From: Alexandre Oliva <aoliva@redhat.com>
for  gcc/testsuite/ChangeLog

	PR c++/86823
	* g++.dg/pr86823.C: New.

From-SVN: r267144

gcc/cp/ChangeLog

@@ -1,3 +1,9 @@
+2018-12-14  Jason Merrill <jason@redhat.com>
+
+	PR c++/86823
+	* parser.c (cp_parser_template_id): Rearrange deferred access
+	checks into the firewall.
+
 2018-12-14  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/82294

gcc/cp/parser.c

@@ -16187,16 +16187,18 @@ cp_parser_template_id (cp_parser *parser,
 				   is_declaration,
 				   tag_type,
 				   &is_identifier);
+
+  /* Push any access checks inside the firewall we're about to create.  */
+  vec<deferred_access_check, va_gc> *checks = get_deferred_access_checks ();
+  pop_deferring_access_checks ();
   if (templ == error_mark_node || is_identifier)
-    {
-      pop_deferring_access_checks ();
-      return templ;
-    }
+    return templ;
 
   /* Since we're going to preserve any side-effects from this parse, set up a
      firewall to protect our callers from cp_parser_commit_to_tentative_parse
      in the template arguments.  */
   tentative_firewall firewall (parser);
+  reopen_deferring_access_checks (checks);
 
   /* If we find the sequence `[:' after a template-name, it's probably
      a digraph-typo for `< ::'. Substitute the tokens and check if we can

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2018-12-14  Alexandre Oliva <aoliva@redhat.com>
+
+	PR c++/86823
+	* g++.dg/pr86823.C: New.
+
 2018-12-14  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/82294

gcc/testsuite/g++.dg/pr86823.C

@@ -0,0 +1,15 @@
+// { dg-do compile }
+
+struct X {
+private:
+  template<typename T>
+  struct Y {
+    int data;
+  };
+public:
+  int value;
+};
+
+int main() {
+  typename X::Y<int> a; // { dg-error "private" }
+}