[wasm][anyref] Add support for js-to-wasm and wasm-to-js wrappers

R=titzer@chromium.org

Bug: v8:7581
Change-Id: Ib100a45ad51ec6b6a0400cfe97fe918089c04ead
Reviewed-on: https://chromium-review.googlesource.com/998095
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52468}

src/compiler/wasm-compiler.cc

@@ -2840,6 +2840,8 @@ Node* WasmGraphBuilder::ToJS(Node* node, wasm::ValueType type) {
       return BuildChangeFloat64ToTagged(node);
     case wasm::kWasmF64:
       return BuildChangeFloat64ToTagged(node);
+    case wasm::kWasmAnyRef:
+      return node;
     case wasm::kWasmStmt:
       return jsgraph()->UndefinedConstant();
     default:
@@ -2922,6 +2924,11 @@ Node* WasmGraphBuilder::FromJS(Node* node, Node* js_context,
                                wasm::ValueType type) {
   DCHECK_NE(wasm::kWasmStmt, type);
 
+  // The parameter is of type AnyRef, we take it as is.
+  if (type == wasm::kWasmAnyRef) {
+    return node;
+  }
+
   // Do a JavaScript ToNumber.
   Node* num = BuildJavaScriptToNumber(node, js_context);
 

test/mjsunit/wasm/anyref.js

@@ -0,0 +1,70 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --expose-wasm --experimental-wasm-anyref --expose-gc
+
+load("test/mjsunit/wasm/wasm-constants.js");
+load("test/mjsunit/wasm/wasm-module-builder.js");
+
+(function testAnyRefIdentityFunction() {
+  print(arguments.callee.name);
+  const builder = new WasmModuleBuilder();
+  builder.addFunction('main', kSig_r_r)
+      .addBody([kExprGetLocal, 0])
+      .exportFunc();
+
+
+  const instance = builder.instantiate();
+
+  let obj = {'hello' : 'world'};
+  assertEquals(obj, instance.exports.main(obj));
+  assertEquals(1234, instance.exports.main(1234));
+  assertEquals(123.4, instance.exports.main(123.4));
+  assertEquals(undefined, instance.exports.main(undefined));
+  assertEquals(null, instance.exports.main(null));
+  assertEquals(print, instance.exports.main(print));
+})();
+
+(function testPassAnyRefToImportedFunction() {
+  print(arguments.callee.name);
+  const builder = new WasmModuleBuilder();
+  const sig_index = builder.addType(kSig_v_r);
+  const imp_index = builder.addImport("q", "func", sig_index);
+  builder.addFunction('main', sig_index)
+      .addBody([kExprGetLocal, 0,
+      kExprCallFunction, imp_index])
+      .exportFunc();
+
+  function checkFunction(value) {
+    assertEquals('world', value.hello);
+  }
+
+  const instance = builder.instantiate({q: {func: checkFunction}});
+
+  instance.exports.main({hello: 'world'});
+})();
+
+(function testPassAnyRefWithGC() {
+  print(arguments.callee.name);
+  const builder = new WasmModuleBuilder();
+  const ref_sig = builder.addType(kSig_v_r);
+  const void_sig = builder.addType(kSig_v_v);
+  const imp_index = builder.addImport("q", "func", ref_sig);
+  const gc_index = builder.addImport("q", "gc", void_sig);
+  // First call the gc, then check if the object still exists.
+  builder.addFunction('main', ref_sig)
+      .addBody([
+        kExprCallFunction, gc_index,                    // call gc
+        kExprGetLocal, 0, kExprCallFunction, imp_index  // call import
+      ])
+      .exportFunc();
+
+  function checkFunction(value) {
+    assertEquals('world', value.hello);
+  }
+
+  const instance = builder.instantiate({q: {func: checkFunction, gc: gc}});
+
+  instance.exports.main({hello: 'world'});
+})();

test/mjsunit/wasm/wasm-constants.js

@@ -93,6 +93,7 @@ let kWasmI64 = 0x7e;
 let kWasmF32 = 0x7d;
 let kWasmF64 = 0x7c;
 let kWasmS128  = 0x7b;
+let kWasmAnyRef = 0x6f;
 
 let kExternalFunction = 0;
 let kExternalTable = 1;
@@ -133,6 +134,8 @@ let kSig_iii_ii = makeSig([kWasmI32, kWasmI32], [kWasmI32, kWasmI32, kWasmI32]);
 let kSig_v_f = makeSig([kWasmF32], []);
 let kSig_f_f = makeSig([kWasmF32], [kWasmF32]);
 let kSig_d_d = makeSig([kWasmF64], [kWasmF64]);
+let kSig_r_r = makeSig([kWasmAnyRef], [kWasmAnyRef]);
+let kSig_v_r = makeSig([kWasmAnyRef], []);
 
 function makeSig(params, results) {
   return {params: params, results: results};