From 6e59fc1b71f2098c8baf90a6c54e5a33b7291e94 Mon Sep 17 00:00:00 2001
From: Cliff Click <cliffc@acm.org>
Date: Sat, 19 Sep 2026 22:31:42 -0700
Subject: Unify mixed-return checking and results

Unify dominator caching.
---
 .../test/java/com/seaofnodes/simple/Chapter10Test.java   | 13 +++++++++++++
 .../test/java/com/seaofnodes/simple/Chapter12Test.java   | 14 ++++++++++++++
 .../test/java/com/seaofnodes/simple/Chapter18Test.java   | 16 ++++++++++++++++
 .../com/seaofnodes/simple/node/PrintTestSupport.java     | 11 +++++++++--
 4 files changed, 52 insertions(+), 2 deletions(-)

(limited to 'chapter24/src/test/java/com')

diff --git a/chapter24/src/test/java/com/seaofnodes/simple/Chapter10Test.java b/chapter24/src/test/java/com/seaofnodes/simple/Chapter10Test.java
index c1b5e3a8..d7a74f18 100644
--- a/chapter24/src/test/java/com/seaofnodes/simple/Chapter10Test.java
+++ b/chapter24/src/test/java/com/seaofnodes/simple/Chapter10Test.java
@@ -6,6 +6,19 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
 
 public class Chapter10Test {
+    @Test public void testDeadReferenceReturn() {
+        for( String body : new String[] {
+            "return new S; return 0;",
+            "if(1) return new S; else return 0;"
+        } ) {
+            String src = "struct S { int x; }; " + body;
+            var code = new CodeGen(src).parse().opto().typeCheck();
+            org.junit.Assert.assertTrue(body,
+                code.expr()._type instanceof com.seaofnodes.simple.type.TypeMemPtr);
+        }
+    }
+
+
 
     // Issue #246: null-check guards start in Chapter 10; arrays arrive in Chapter 15.
     private static final String NULLABLE_POINT_SOURCE = """
diff --git a/chapter24/src/test/java/com/seaofnodes/simple/Chapter12Test.java b/chapter24/src/test/java/com/seaofnodes/simple/Chapter12Test.java
index 8069ddaa..21759b78 100644
--- a/chapter24/src/test/java/com/seaofnodes/simple/Chapter12Test.java
+++ b/chapter24/src/test/java/com/seaofnodes/simple/Chapter12Test.java
@@ -7,6 +7,20 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
 
 public class Chapter12Test {
+    @Test public void testDeadNumericReturns() {
+        for( String[] test : new String[][] {
+            {"if(1) return 7; else return 2.5;", "7"},
+            {"if(0) return 7; else return 2.5;", "2.5"},
+            {"return 7; return 2.5;", "7"},
+            {"return 2.5; return 7;", "2.5"}
+        } ) {
+            String src = test[0];
+            var code = new CodeGen(src).parse().opto().typeCheck();
+            assertEquals(src,test[1],Eval2.eval(code,0));
+        }
+    }
+
+
     @Test
     public void testJig() {
         CodeGen code = new CodeGen(
diff --git a/chapter24/src/test/java/com/seaofnodes/simple/Chapter18Test.java b/chapter24/src/test/java/com/seaofnodes/simple/Chapter18Test.java
index 764356cf..5dbbf0f1 100644
--- a/chapter24/src/test/java/com/seaofnodes/simple/Chapter18Test.java
+++ b/chapter24/src/test/java/com/seaofnodes/simple/Chapter18Test.java
@@ -11,6 +11,22 @@ import static org.junit.Assert.*;
 import static org.junit.Assert.fail;
 
 public class Chapter18Test {
+    @Test public void testReachableMixedReturns() {
+        for( String[] test : new String[][] {
+            {"if(arg) return 7; else return 2.5;", "No common type amongst int and f64"},
+            {"struct S { int x; }; if(arg) return new S; else return 0;",
+             "No common type amongst int and reference"}
+        } ) {
+            try {
+                new CodeGen(test[0]).parse().opto().typeCheck();
+                fail("Expected incompatible return types: " + test[0]);
+            } catch( Parser.ParseException e ) {
+                assertEquals(test[1],e.getMessage());
+            }
+        }
+    }
+
+
     @Test public void testPrintingForwardReferenceScope() throws Exception {
         new CodeGen("return 0;").parse();
         var declared = TypeMemPtr.make(TypeStruct.open("PrintForward"));
diff --git a/chapter24/src/test/java/com/seaofnodes/simple/node/PrintTestSupport.java b/chapter24/src/test/java/com/seaofnodes/simple/node/PrintTestSupport.java
index 01d471bf..ceea1de5 100644
--- a/chapter24/src/test/java/com/seaofnodes/simple/node/PrintTestSupport.java
+++ b/chapter24/src/test/java/com/seaofnodes/simple/node/PrintTestSupport.java
@@ -21,17 +21,24 @@ public class PrintTestSupport {
         var ins = new IdentityHashMap<Node,Node[]>();
         var outs = new IdentityHashMap<Node,Node[]>();
         var hashes = new IdentityHashMap<Node,Integer>();
+        var versions = new IdentityHashMap<Node,Integer>();
         var depths = new IdentityHashMap<Node,Integer>();
         for( Node n : nodes ) {
             ins.put(n,n._inputs.toArray(new Node[0]));
             outs.put(n,n._outputs.toArray(new Node[0]));
             hashes.put(n,hash.getInt(n));
-            if( n instanceof CFGNode cfg ) depths.put(n,cfg._idepth);
+            if( n instanceof CFGNode cfg ) {
+                depths.put(n,(int)cfg._idepth);
+                versions.put(n,(int)cfg._idepthVersion);
+            }
         }
         print.run();
         for( Node n : nodes ) {
             assertEquals("hash of node "+n._nid,(int)hashes.get(n),hash.getInt(n));
-            if( n instanceof CFGNode cfg ) assertEquals("depth of node "+n._nid,(int)depths.get(n),cfg._idepth);
+            if( n instanceof CFGNode cfg ) {
+                assertEquals("depth of node "+n._nid,(int)depths.get(n),cfg._idepth);
+                assertEquals("depth version of node "+n._nid,(int)versions.get(n),cfg._idepthVersion);
+            }
             assertEquals(ins.get(n).length,n.nIns());
             assertEquals(outs.get(n).length,n.nOuts());
             for( int i=0; i<n.nIns(); i++ ) assertSame(ins.get(n)[i],n.in(i));
-- 
cgit v1.2.3