Check that a struct field name of a struct declaration does not shadow an enum or a struct definition.

src/main/java/de/hsrm/compiler/Klang/ContextAnalysis.java

@@ -799,6 +799,16 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
       throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
     }
 
+    if (structDefs.containsKey(structFieldName)) {
+      var error = "Struct field name " + structFieldName + " shadows a struct of the same name.";
+      throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+    }
+
+    if (enumDefs.containsKey(structFieldName)) {
+      var error = "Struct field name " + structFieldName + " shadows an enum of the same name.";
+      throw new RuntimeException(Helper.getErrorPrefix(line, col) + error);
+    }
+
     var structField = new StructField(structFieldName);
     structField.type = structFieldType;
     structField.line = line;

src/test/java/StructDefinitionTest.java

@@ -27,6 +27,38 @@ public class StructDefinitionTest {
         assertDoesNotThrow(() -> ctxAnal.visit(tree));
     }
 
+    @Test
+    void shouldNotThrowIfStructFieldTypeIsReferringToStruct() {
+        // given
+        var tree = Helper.prepareParser("struct a { hello: int; } struct b { world: a; } function foo(): int { return 1; } foo();");
+        var ctxAnal = new ContextAnalysis(Helper.getFuncs(tree), Helper.getStructs(tree), Helper.getEnums(tree));
+
+        // when / then
+        assertDoesNotThrow(() -> ctxAnal.visit(tree));
+    }
+
+    @Test
+    void shouldThrowExceptionIfStructFieldNameShadowsAStruct() {
+        // given
+        var tree = Helper.prepareParser("struct bar { a: int; } struct baz { bar: int; } function foo(): int { return 1; } foo();");
+        var ctxAnal = new ContextAnalysis(Helper.getFuncs(tree), Helper.getStructs(tree), Helper.getEnums(tree));
+
+        // when / then
+        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
+        assertEquals("Error in line 1:36 Struct field name bar shadows a struct of the same name.", e.getMessage());
+    }
+
+    @Test
+    void shouldThrowExceptionIfStructFieldNameShadowsAnEnum() {
+        // given
+        var tree = Helper.prepareParser("enum bar { A, B } struct baz { bar: int; } function foo(): int { return 1; } foo();");
+        var ctxAnal = new ContextAnalysis(Helper.getFuncs(tree), Helper.getStructs(tree), Helper.getEnums(tree));
+
+        // when / then
+        var e = assertThrows(RuntimeException.class, () -> ctxAnal.visit(tree));
+        assertEquals("Error in line 1:31 Struct field name bar shadows an enum of the same name.", e.getMessage());
+    }
+
     @Test
     void shouldThrowExceptionIfStructFieldTypeIsNotDefined() {
         // given