Disallow using 'super' in all context except method calls.

skinny85 · Apr 20, 2024 · 456ad1b · 456ad1b
1 parent a930017
commit 456ad1b
Show file tree

Hide file tree

Showing 4 changed files with 67 additions and 29 deletions.
diff --git a/...ain/java/com/endoflineblog/truffle/part_13/nodes/exprs/arrays/ArrayIndexReadExprNode.java b/...ain/java/com/endoflineblog/truffle/part_13/nodes/exprs/arrays/ArrayIndexReadExprNode.java
@@ -128,7 +128,10 @@ protected Object readIndexOrProperty(Object target, Object indexOrProperty) {
 
     @Override
     public Object evaluateAsReceiver(VirtualFrame frame) {
-        return this.getArrayExpr().executeGeneric(frame);
+        EasyScriptExprNode arrayExpr = this.getArrayExpr();
+        return arrayExpr instanceof SuperExprNode
+                ? arrayExpr.evaluateAsReceiver(frame)
+                : arrayExpr.executeGeneric(frame);
     }
 
     @Override

diff --git a/...14/src/main/java/com/endoflineblog/truffle/part_13/nodes/exprs/objects/SuperExprNode.java b/...14/src/main/java/com/endoflineblog/truffle/part_13/nodes/exprs/objects/SuperExprNode.java
@@ -29,16 +29,13 @@ public SuperExprNode(ClassPrototypeObject classPrototype) {
 
     @Override
     public Object executeGeneric(VirtualFrame frame) {
-        // executeGeneric() simply returns 'this'
-        // (that will be the method that property access Nodes use to establish the method call receiver,
-        // in their evaluateAsReceiver() methods)
-        return this.thisExprNode.executeGeneric(frame);
+        throw new EasyScriptException("'super' is not allowed here");
     }
 
     @Override
     public Object evaluateAsReceiver(VirtualFrame frame) {
         // receiver should be 'this' for a 'super()' call
-        return this.executeGeneric(frame);
+        return this.thisExprNode.executeGeneric(frame);
     }
 
     @Override

diff --git a/...n/java/com/endoflineblog/truffle/part_13/nodes/exprs/properties/PropertyReadExprNode.java b/...n/java/com/endoflineblog/truffle/part_13/nodes/exprs/properties/PropertyReadExprNode.java
@@ -38,7 +38,10 @@ protected Object readProperty(Object target) {
 
     @Override
     public Object evaluateAsReceiver(VirtualFrame frame) {
-        return this.getTargetExpr().executeGeneric(frame);
+        EasyScriptExprNode targetExpr = this.getTargetExpr();
+        return targetExpr instanceof SuperExprNode
+                ? targetExpr.evaluateAsReceiver(frame)
+                : targetExpr.executeGeneric(frame);
     }
 
     @Override

diff --git a/part-14/src/test/java/com/endoflineblog/truffle/part_13/InheritanceTest.java b/part-14/src/test/java/com/endoflineblog/truffle/part_13/InheritanceTest.java
@@ -94,28 +94,6 @@ void super_is_static_not_dynamic() {
         assertEquals("Base", result.asString());
     }
 
-    @Test
-    void writing_to_super_writes_to_this() {
-        Value result = this.context.eval("ezs", "" +
-                "class Base { " +
-                "    constructor() { " +
-                "        this.x = 11; " +
-                "    } " +
-                "} " +
-                "class Derived extends Base { " +
-                "    setSuperX(x) {" +
-                "        super.x = x; " +
-                "    } " +
-                "} " +
-                "const obj = new Derived(); " +
-                "let x = obj.x; " +
-                "obj.setSuperX(3); " +
-                "x + obj.x;"
-        );
-
-        assertEquals(14, result.asInt());
-    }
-
     @Test
     void object_class_can_be_instantiated() {
         Value result = this.context.eval("ezs", "" +
@@ -192,6 +170,63 @@ void extending_non_existent_class_is_an_error() {
         }
     }
 
+    @Test
+    void writing_to_super_is_an_error() {
+        try {
+            this.context.eval("ezs", "" +
+                    "class Class { " +
+                    "    setSuperX(x) {" +
+                    "        super.x = x; " +
+                    "    } " +
+                    "} " +
+                    "new Class().setSuperX(3); "
+            );
+            fail("expected PolyglotException to be thrown");
+        } catch (PolyglotException e) {
+            assertTrue(e.isGuestException());
+            assertFalse(e.isInternalError());
+            assertEquals("'super' is not allowed here", e.getMessage());
+        }
+    }
+
+    @Test
+    void reading_from_super_is_an_error() {
+        try {
+            this.context.eval("ezs", "" +
+                    "class Class { " +
+                    "    getSuperX() {" +
+                    "        return super.x; " +
+                    "    } " +
+                    "} " +
+                    "new Class().getSuperX(); "
+            );
+            fail("expected PolyglotException to be thrown");
+        } catch (PolyglotException e) {
+            assertTrue(e.isGuestException());
+            assertFalse(e.isInternalError());
+            assertEquals("'super' is not allowed here", e.getMessage());
+        }
+    }
+
+    @Test
+    void super_cannot_be_used_by_itself() {
+        try {
+            this.context.eval("ezs", "" +
+                    "class Class { " +
+                    "    getSuper() {" +
+                    "        return super; " +
+                    "    } " +
+                    "} " +
+                    "new Class().getSuper(); "
+            );
+            fail("expected PolyglotException to be thrown");
+        } catch (PolyglotException e) {
+            assertTrue(e.isGuestException());
+            assertFalse(e.isInternalError());
+            assertEquals("'super' is not allowed here", e.getMessage());
+        }
+    }
+
     @Test
     public void benchmark_returns_its_input() {
         var input = 100;