PR c++/91521 - wrong error with operator->.

	* decl.c (grokdeclarator): Return error_mark_node for an invalid
	trailing return type.

	* g++.dg/parse/operator8.C: New test.

From-SVN: r274891

gcc/cp/ChangeLog

 2019-08-23  Marek Polacek  <polacek@redhat.com>
 
+	PR c++/91521 - wrong error with operator->.
+	* decl.c (grokdeclarator): Return error_mark_node for an invalid
+	trailing return type.
+
 	PR c++/79817 - attribute deprecated on namespace.
 	* cp-tree.h (cp_warn_deprecated_use_scopes): Declare.
 	* decl.c (grokdeclarator): Call cp_warn_deprecated_use_scopes.

gcc/cp/decl.c

@@ -11549,6 +11549,8 @@ grokdeclarator (const cp_declarator *declarator,
 		else if (late_return_type
 			 && sfk != sfk_conversion)
 		  {
+		    if (late_return_type == error_mark_node)
+		      return error_mark_node;
 		    if (cxx_dialect < cxx11)
 		      /* Not using maybe_warn_cpp0x because this should
 			 always be an error.  */

gcc/testsuite/ChangeLog

+2019-08-23  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/91521 - wrong error with operator->.
+	* g++.dg/parse/operator8.C: New test.
+
 2019-08-23  Segher Boessenkool  <segher@kernel.crashing.org>
 
 	PR target/91481

gcc/testsuite/g++.dg/parse/operator8.C

+// PR c++/91521 - wrong error with operator->.
+// { dg-do compile }
+
+struct foo {
+	int bar() { return 0; }
+	foo* operator->() { return this; }
+};
+
+int main()
+{
+	int pt(foo()->bar());
+	return pt;
+}