wasm gc: fix issue with extracting elements from arrays of JS objects

jso/impl/src/main/java/org/teavm/jso/impl/JS.java

@@ -785,4 +785,7 @@ public static native JSObject construct(JSObject cls, JSObject a, JSObject b, JS
     @InjectedBy(JSNativeInjector.class)
     @NoSideEffects
     public static native boolean isNull(JSObject o);
+
+    @NoSideEffects
+    public static native Object jsArrayItem(Object array, int index);
 }

jso/impl/src/main/java/org/teavm/jso/impl/JSClassProcessor.java

@@ -435,6 +435,16 @@ private void processGetFromArray(GetElementInstruction insn) {
             unwrap.setLocation(insn.getLocation());
             insn.setReceiver(unwrap.getArguments().get(0));
             insn.insertNext(unwrap);
+
+            if (wasmGC) {
+                var invoke = new InvokeInstruction();
+                invoke.setType(InvocationType.SPECIAL);
+                invoke.setMethod(new MethodReference(JS.class, "jsArrayItem", Object.class, int.class, Object.class));
+                invoke.setReceiver(insn.getReceiver());
+                invoke.setArguments(insn.getArray(), insn.getIndex());
+                invoke.setLocation(insn.getLocation());
+                insn.replace(invoke);
+            }
         }
     }
 

jso/impl/src/main/java/org/teavm/jso/impl/wasmgc/WasmGCJSDependencies.java

@@ -19,7 +19,9 @@
 import static org.teavm.jso.impl.wasmgc.WasmGCJSConstants.STRING_TO_JS;
 import org.teavm.dependency.AbstractDependencyListener;
 import org.teavm.dependency.DependencyAgent;
+import org.teavm.dependency.MethodDependency;
 import org.teavm.jso.JSObject;
+import org.teavm.jso.impl.JS;
 import org.teavm.jso.impl.JSWrapper;
 import org.teavm.model.MethodReference;
 
@@ -37,4 +39,13 @@ public void started(DependencyAgent agent) {
         agent.linkMethod(new MethodReference(JSWrapper.class, "createWrapper", JSObject.class, Object.class))
                 .use();
     }
+
+    @Override
+    public void methodReached(DependencyAgent agent, MethodDependency method) {
+        if (method.getMethod().getOwnerName().equals(JS.class.getName())) {
+            if (method.getMethod().getName().equals("jsArrayItem")) {
+                method.getVariable(1).getArrayItem().connect(method.getResult());
+            }
+        }
+    }
 }

jso/impl/src/main/java/org/teavm/jso/impl/wasmgc/WasmGCJSIntrinsic.java

@@ -22,6 +22,7 @@
 import org.teavm.backend.wasm.intrinsics.gc.WasmGCIntrinsicContext;
 import org.teavm.backend.wasm.model.WasmFunction;
 import org.teavm.backend.wasm.model.WasmType;
+import org.teavm.backend.wasm.model.expression.WasmArrayGet;
 import org.teavm.backend.wasm.model.expression.WasmBlock;
 import org.teavm.backend.wasm.model.expression.WasmBranch;
 import org.teavm.backend.wasm.model.expression.WasmCall;
@@ -32,6 +33,7 @@
 import org.teavm.jso.JSObject;
 import org.teavm.jso.impl.JS;
 import org.teavm.model.MethodReference;
+import org.teavm.model.ValueType;
 
 class WasmGCJSIntrinsic implements WasmGCIntrinsic {
     private WasmFunction globalFunction;
@@ -53,9 +55,11 @@ public WasmExpression apply(InvocationExpr invocation, WasmGCIntrinsicContext co
                 return new WasmCall(getGlobalFunction(context), name);
             }
             case "throwCCEIfFalse":
-                return throwCCEIfFalse(context, invocation);
+                return throwCCEIfFalse(invocation, context);
             case "isNull":
                 return new WasmIsNull(context.generate(invocation.getArguments().get(0)));
+            case "jsArrayItem":
+                return arrayItem(invocation, context);
             default:
                 throw new IllegalArgumentException();
         }
@@ -74,7 +78,7 @@ private WasmFunction getGlobalFunction(WasmGCIntrinsicContext context) {
         return globalFunction;
     }
 
-    private WasmExpression throwCCEIfFalse(WasmGCIntrinsicContext context, InvocationExpr invocation) {
+    private WasmExpression throwCCEIfFalse(InvocationExpr invocation, WasmGCIntrinsicContext context) {
         var block = new WasmBlock(false);
         block.setType(WasmType.Reference.EXTERN);
 
@@ -93,4 +97,10 @@ private WasmExpression throwCCEIfFalse(WasmGCIntrinsicContext context, Invocatio
         block.getBody().add(context.generate(invocation.getArguments().get(1)));
         return block;
     }
+
+    private WasmExpression arrayItem(InvocationExpr invocation, WasmGCIntrinsicContext context) {
+        var array = context.generate(invocation.getArguments().get(0));
+        var arrayType = context.classInfoProvider().getClassInfo(ValueType.parse(Object[].class)).getArray();
+        return new WasmArrayGet(arrayType, array, context.generate(invocation.getArguments().get(1)));
+    }
 }

jso/impl/src/main/java/org/teavm/jso/impl/wasmgc/WasmGCJso.java

@@ -44,6 +44,8 @@ public static void install(TeaVMHost host, TeaVMWasmGCHost wasmGCHost, JSBodyRep
         wasmGCHost.addIntrinsic(new MethodReference(JS.class, "throwCCEIfFalse", boolean.class, JSObject.class,
                 JSObject.class), jsIntrinsic);
         wasmGCHost.addIntrinsic(new MethodReference(JS.class, "isNull", JSObject.class, boolean.class), jsIntrinsic);
+        wasmGCHost.addIntrinsic(new MethodReference(JS.class, "jsArrayItem", Object.class, int.class, Object.class),
+                jsIntrinsic);
 
         var wrapperIntrinsic = new WasmGCJSWrapperIntrinsic();
         wasmGCHost.addIntrinsic(new MethodReference(JSWrapper.class, "wrap", JSObject.class, Object.class),

tests/src/test/java/org/teavm/jso/test/ConversionTest.java

@@ -138,7 +138,6 @@ public void passesJSObject() {
     }
 
     @Test
-    @SkipPlatform(TestPlatform.WEBASSEMBLY_GC)
     public void convertsArrayOfJSObject() {
         assertEquals("(foo)", surround(new JSString[] { JSString.valueOf("foo") })[0].stringValue());
         assertEquals("(foo)", surround(new JSString[][] {{ JSString.valueOf("foo") }})[0][0].stringValue());