From 14b5cdd4d0dfcc4c46c812af55aba3ab21d97b26 Mon Sep 17 00:00:00 2001
From: peter klausler <pklausler@nvidia.com>
Date: Thu, 2 May 2019 15:19:37 -0700
Subject: [PATCH] [flang] Fix f90_correct test failure

Original-commit: flang-compiler/f18@ff7a5af50bb4305fe903e38216b68724157a6a33
Reviewed-on: https://github.com/flang-compiler/f18/pull/438
---
 flang/lib/parser/preprocessor.cc | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/flang/lib/parser/preprocessor.cc b/flang/lib/parser/preprocessor.cc
index 0c6f14cba663..eb3be0c17510 100644
--- a/flang/lib/parser/preprocessor.cc
+++ b/flang/lib/parser/preprocessor.cc
@@ -319,8 +319,10 @@ std::optional<TokenSequence> Preprocessor::MacroReplacement(
         }
       }
     }
-    if (argStart.size() == 1 && argStart[0] == k) {
-      // empty parentheses, no arguments
+    if (argStart.size() == 1 && k == argStart[0] &&
+        def.argumentCount() == 0) {
+      // Subtle: () is zero arguments, not one empty argument,
+      // unless one argument was expected.
       argStart.clear();
     }
     if (k >= tokens || argStart.size() < def.argumentCount() ||