[wasm] Freeze exports object

src/wasm/wasm-module.cc

 // Copyright 2015 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.
 
 #include <memory>
 
 #include "src/base/adapters.h"
 #include "src/base/atomic-utils.h"
 #include "src/code-stubs.h"
 #include "src/compiler/wasm-compiler.h"
@@ skipping 1828 matching lines @@
         }
       }
       v8::Maybe<bool> status = JSReceiver::DefineOwnProperty(
           isolate_, exports_object, name, &desc, Object::THROW_ON_ERROR);
       if (!status.IsJust()) {
         thrower_->LinkError("export of %.*s failed.", name->length(),
                             name->ToCString().get());
         return;
       }
     }
+
+    if (module_->origin == kWasmOrigin) {
+      v8::Maybe<bool> success = JSReceiver::SetIntegrityLevel(
+          exports_object, FROZEN, Object::DONT_THROW);
+      DCHECK(success.FromMaybe(false));
+      USE(success);
+    }
   }
 
   void InitializeTables(Handle<FixedArray> code_table,
                         Handle<WasmInstanceObject> instance) {
     Handle<FixedArray> old_function_tables =
         compiled_module_->function_tables();
     int function_table_count =
         static_cast<int>(module_->function_tables.size());
     Handle<FixedArray> new_function_tables =
         isolate_->factory()->NewFixedArray(function_table_count);
@@ skipping 449 matching lines @@
   CHECK(!compiled_module->has_weak_owning_instance());
 }
 
 void testing::ValidateOrphanedInstance(Isolate* isolate,
                                        Handle<WasmInstanceObject> instance) {
   DisallowHeapAllocation no_gc;
   WasmCompiledModule* compiled_module = instance->get_compiled_module();
   CHECK(compiled_module->has_weak_wasm_module());
   CHECK(compiled_module->ptr_to_weak_wasm_module()->cleared());
 }