fix parsing nested structs

2 files changed, 16 insertions, 0 deletions

diff --git a/chapter15/src/main/java/com/seaofnodes/simple/node/StartNode.java b/chapter15/src/main/java/com/seaofnodes/simple/node/StartNode.java
index 14bf37f5..5964e19f 100644
--- a/chapter15/src/main/java/com/seaofnodes/simple/node/StartNode.java
+++ b/chapter15/src/main/java/com/seaofnodes/simple/node/StartNode.java
@@ -45,6 +45,9 @@ public class StartNode extends CFGNode implements MultiNode {
             n._type = args[f._alias];
             scope.define(name, tm_decl, n);
         }
+        for (int i = 0; i < args.length; i++)
+            if (args[i] == null)
+                args[i] = Type.TOP; // We parsed a nested struct/array. Avoid nulls until a caller replaces this alias.
         _type = _args = TypeTuple.make(args);
     }
 
diff --git a/chapter15/src/test/java/com/seaofnodes/simple/Chapter15Test.java b/chapter15/src/test/java/com/seaofnodes/simple/Chapter15Test.java
index dff39ba3..88924c52 100644
--- a/chapter15/src/test/java/com/seaofnodes/simple/Chapter15Test.java
+++ b/chapter15/src/test/java/com/seaofnodes/simple/Chapter15Test.java
@@ -181,6 +181,19 @@ return root;
         assertEquals("Obj<Tree>{_kids=Obj<*Tree?[]>{#=2,[]=[Obj<Tree>{_kids=null},null]}}", Evaluator.evaluate(stop,  0).toString());
     }
 
+    @Test
+    public void testNestedStructAddMemProj() {
+        Parser parser = new Parser(
+"""
+struct S {
+    int a;
+    int[] b;
+}
+return 0;
+""");
+        StopNode stop = parser.parse(false);
+        assertEquals("return 0;", stop.toString());
+    }
 
     @Test
     public void testRollingSum() {