Parser fix OR temps

5 files changed, 86 insertions, 4 deletions

diff --git a/chapter23/src/main/java/com/seaofnodes/simple/Parser.java b/chapter23/src/main/java/com/seaofnodes/simple/Parser.java
index 8a6b1967..76898bea 100644
--- a/chapter23/src/main/java/com/seaofnodes/simple/Parser.java
+++ b/chapter23/src/main/java/com/seaofnodes/simple/Parser.java
@@ -590,7 +590,7 @@ public class Parser {
         };
         rhs.keep();
         _scope.removeGuards(ifF);
-        if( doRHS )
+        if( doRHS || fside.equals("||") )
             fScope = _scope;
         pred.unkeep();
 
diff --git a/chapter23/src/test/java/com/seaofnodes/simple/Chapter23Test.java b/chapter23/src/test/java/com/seaofnodes/simple/Chapter23Test.java
index 9d500266..435b675c 100644
--- a/chapter23/src/test/java/com/seaofnodes/simple/Chapter23Test.java
+++ b/chapter23/src/test/java/com/seaofnodes/simple/Chapter23Test.java
@@ -13,6 +13,48 @@ import static org.junit.Assert.*;
 public class Chapter23Test {
 
     @Test
+    public void testOrRhsLoopLocal() throws IOException {
+        checkOrRhsLoop("""
+            struct S { int f; };
+            int x = 0;
+            int result = (arg & 1) || (new S {
+                while (x < 3) x++;
+                f = ++x;
+            }).f;
+            return x * 10 + result;
+            """);
+    }
+
+    @Test
+    public void testOrRhsLoopMemory() throws IOException {
+        checkOrRhsLoop("""
+            struct S { int f; };
+            S !s = new S;
+            int result = (arg & 1) || (new S {
+                while (s.f < 3) s.f++;
+                s.f++;
+                f = s.f;
+            }).f;
+            return s.f * 10 + result;
+            """);
+    }
+
+    private static void checkOrRhsLoop(String src) throws IOException {
+        CodeGen code = new CodeGen(src).driver("riscv", "SystemV", null);
+        for (int arg : new int[]{0, 1, 2, 3}) {
+            byte[] image = new byte[1 << 20];
+            System.arraycopy(code._encoding.bits(), 0, image, 0, code._encoding._bits.size());
+            EvalRisc5 r5 = new EvalRisc5(image, 1 << 16);
+            r5.regs[riscv.A0] = arg;
+            assertEquals("Execution must finish", 0, r5.step(1000));
+            // False LHS runs the loop and final increment, returning 4.
+            // True LHS skips all RHS effects and returns the LHS value, 1.
+            assertEquals("OR result and side effects for arg=" + arg,
+                (arg & 1) == 0 ? 44 : 1, r5.regs[riscv.A0]);
+        }
+    }
+
+    @Test
     public void testJig() throws IOException {
         String src =
 """
diff --git a/chapter24/src/main/java/com/seaofnodes/simple/Parser.java b/chapter24/src/main/java/com/seaofnodes/simple/Parser.java
index f80e8f2c..42aac299 100644
--- a/chapter24/src/main/java/com/seaofnodes/simple/Parser.java
+++ b/chapter24/src/main/java/com/seaofnodes/simple/Parser.java
@@ -597,7 +597,7 @@ public class Parser {
         };
         rhs.keep();
         _scope.removeGuards(ifF);
-        if( doRHS )
+        if( doRHS || fside.equals("||") )
             fScope = _scope;
         pred.unkeep();
 
diff --git a/chapter24/src/test/java/com/seaofnodes/simple/Chapter23Test.java b/chapter24/src/test/java/com/seaofnodes/simple/Chapter23Test.java
index 94e13a87..400f6b52 100644
--- a/chapter24/src/test/java/com/seaofnodes/simple/Chapter23Test.java
+++ b/chapter24/src/test/java/com/seaofnodes/simple/Chapter23Test.java
@@ -13,6 +13,48 @@ import static org.junit.Assert.*;
 public class Chapter23Test {
 
     @Test
+    public void testOrRhsLoopLocal() throws IOException {
+        checkOrRhsLoop("""
+            struct S { int f; };
+            int x = 0;
+            int result = (arg & 1) || (new S {
+                while (x < 3) x++;
+                f = ++x;
+            }).f;
+            return x * 10 + result;
+            """);
+    }
+
+    @Test
+    public void testOrRhsLoopMemory() throws IOException {
+        checkOrRhsLoop("""
+            struct S { int f; };
+            S !s = new S;
+            int result = (arg & 1) || (new S {
+                while (s.f < 3) s.f++;
+                s.f++;
+                f = s.f;
+            }).f;
+            return s.f * 10 + result;
+            """);
+    }
+
+    private static void checkOrRhsLoop(String src) throws IOException {
+        CodeGen code = new CodeGen(src).driver("riscv", "SystemV", null);
+        for (int arg : new int[]{0, 1, 2, 3}) {
+            byte[] image = new byte[1 << 20];
+            System.arraycopy(code._encoding.bits(), 0, image, 0, code._encoding._bits.size());
+            EvalRisc5 r5 = new EvalRisc5(image, 1 << 16);
+            r5.regs[riscv.A0] = arg;
+            assertEquals("Execution must finish", 0, r5.step(1000));
+            // False LHS runs the loop and final increment, returning 4.
+            // True LHS skips all RHS effects and returns the LHS value, 1.
+            assertEquals("OR result and side effects for arg=" + arg,
+                (arg & 1) == 0 ? 44 : 1, r5.regs[riscv.A0]);
+        }
+    }
+
+    @Test
     public void testJig() throws IOException {
         //String src = Files.readString(Path.of("src/test/java/com/seaofnodes/simple/progs/jig.smp"));
         String src = Files.readString(Path.of("docs/examples/BubbleSort.smp"));
diff --git a/docs/chapter-backports.md b/docs/chapter-backports.md
index 9761bade..6af70cff 100644
--- a/docs/chapter-backports.md
+++ b/docs/chapter-backports.md
@@ -19,8 +19,6 @@ the correction into the chapter's representation, not the entire modern file.
 
 | ID | Change | Proposed destination | Scope and acceptance evidence |
 |---|---|---|---|
-| B04 | Preserve comparison results while releasing parser temporaries | 24 | `parseComparison` lifetime fix in `414931c8`. Reduce seed `-8212834489697770130`; exclude unrelated `<clinit>` cleanup in that commit. |
-| B05 | Preserve RHS control, memory, and local updates in logical OR | 23 through 24; **audit** earliest implementation | Chapter 25 `parseIf` retains `_scope` for the false-side `||` expression. Test scalar and field updates and short-circuit behavior. Avoid importing GuardNode. |
 | B06 | Decode string escapes; reject unknown/truncated escapes | 22 through 24 | Literal scanner only. Check newline, tab, carriage return, backslash, quote, NUL, and malformed input. |
 | B07 | Decode character escapes; reject truncated literals | 22 through 24 | Separate patch sharing B06's helper. Check values and errors; `parseChar` first appears in 22. |
 | B08 | Complete `&=` and `|=` syntax sugar | 17 onward; **audit** availability of bitwise operators | A small language addition, not a correctness-only patch. Move lexer and assignment expansion together. Check locals, fields, arrays, and exactly-once address evaluation. |