From 37b80b31ab155414867ee72bea2fd618bbb3f69d Mon Sep 17 00:00:00 2001
From: Markus Amshove <scm@amshove.dev>
Date: Sun, 10 Sep 2023 16:46:29 +0200
Subject: [PATCH] Raise a diagnostic if FILLER is used outside of REDEFINE

---
 .../natparse/parsing/DefineDataParser.java    |  4 +--
 .../parsing/DefineDataParserShould.java       | 28 +++++++++++++++++++
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/libs/natparse/src/main/java/org/amshove/natparse/parsing/DefineDataParser.java b/libs/natparse/src/main/java/org/amshove/natparse/parsing/DefineDataParser.java
index 220eefa21..30bd5ddbb 100644
--- a/libs/natparse/src/main/java/org/amshove/natparse/parsing/DefineDataParser.java
+++ b/libs/natparse/src/main/java/org/amshove/natparse/parsing/DefineDataParser.java
@@ -166,7 +166,7 @@ private ScopeNode scope() throws ParseError
 					checkIndependentVariable(variable);
 				}
 
-				if (peekKind(1, SyntaxKind.FILLER))
+				if (peekKind(1, SyntaxKind.FILLER) && peekKind(2, SyntaxKind.OPERAND_SKIP))
 				{
 					var currentRedefineNode = currentRedefine(variable);
 					if (currentRedefineNode != null)
@@ -178,7 +178,7 @@ private ScopeNode scope() throws ParseError
 					}
 					else
 					{
-						// TODO: Diagnostic: Filler can only be used on redefines
+						report(ParserErrors.unexpectedToken(peek(1), "FILLER can only be used in redefinitions"));
 					}
 				}
 
diff --git a/libs/natparse/src/test/java/org/amshove/natparse/parsing/DefineDataParserShould.java b/libs/natparse/src/test/java/org/amshove/natparse/parsing/DefineDataParserShould.java
index 67d57e0fc..7675c19bc 100644
--- a/libs/natparse/src/test/java/org/amshove/natparse/parsing/DefineDataParserShould.java
+++ b/libs/natparse/src/test/java/org/amshove/natparse/parsing/DefineDataParserShould.java
@@ -990,6 +990,34 @@ void parseFillerInRedefines()
 		assertThat(redefine.fillerBytes()).isEqualTo(90);
 	}
 
+	@Test
+	void raiseADiagnosticIfAFillerIsUsedOutsideOfRedefine()
+	{
+		assertDiagnostic("""
+			   DEFINE DATA
+			   LOCAL
+			   1 #GRP
+				2 FILLER 50X
+				2 #SUBSTR (A10)
+			   END-DEFINE
+			""", ParserError.UNEXPECTED_TOKEN);
+	}
+
+	@Test
+	void notRaiseADiagnosticIfAVariableWithNameFillerIsUsedOutsideOfRedefine()
+	{
+		var data = assertParsesWithoutDiagnostics("""
+			   DEFINE DATA
+			   LOCAL
+			   1 #GRP
+				2 FILLER (A5)
+				2 #SUBSTR (A10)
+			   END-DEFINE
+			""");
+
+		assertThat(data.findVariable("FILLER")).isNotNull();
+	}
+
 	@Test
 	void parseSubsequentRedefineFiller()
 	{