[wasm] Introduce instance types for WebAssembly.* objects.

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 <functional>
 #include <memory>
 
 #include "src/code-stubs.h"
 #include "src/debug/interface-types.h"
 #include "src/frames-inl.h"
@@ skipping 141 matching lines @@
         trap_handler::ReleaseHandlerData(index);
         code->set_trap_handler_index(Smi::FromInt(-1));
       }
     }
   }
 
   // weak_wasm_module may have been cleared, meaning the module object
   // was GC-ed. In that case, there won't be any new instances created,
   // and we don't need to maintain the links between instances.
   if (!weak_wasm_module->cleared()) {
-    JSObject* wasm_module = JSObject::cast(weak_wasm_module->value());
-    WasmCompiledModule* current_template =
-        WasmCompiledModule::cast(wasm_module->GetEmbedderField(0));
+    WasmModuleObject* wasm_module =
+        WasmModuleObject::cast(weak_wasm_module->value());
+    WasmCompiledModule* current_template = wasm_module->compiled_module();
 
     TRACE("chain before {\n");
     TRACE_CHAIN(current_template);
     TRACE("}\n");
 
     DCHECK(!current_template->has_weak_prev_instance());
     WeakCell* next = compiled_module->maybe_ptr_to_weak_next_instance();
     WeakCell* prev = compiled_module->maybe_ptr_to_weak_prev_instance();
 
     if (current_template == compiled_module) {
       if (next == nullptr) {
         WasmCompiledModule::Reset(isolate, compiled_module);
       } else {
-        DCHECK(next->value()->IsFixedArray());
-        wasm_module->SetEmbedderField(0, next->value());
+        WasmCompiledModule* next_compiled_module =
+            WasmCompiledModule::cast(next->value());
+        WasmModuleObject::cast(wasm_module)
+            ->set_compiled_module(next_compiled_module);
         DCHECK_NULL(prev);
-        WasmCompiledModule::cast(next->value())->reset_weak_prev_instance();
+        next_compiled_module->reset_weak_prev_instance();
       }
     } else {
       DCHECK(!(prev == nullptr && next == nullptr));
       // the only reason prev or next would be cleared is if the
       // respective objects got collected, but if that happened,
       // we would have relinked the list.
       if (prev != nullptr) {
         DCHECK(!prev->cleared());
         if (next == nullptr) {
           WasmCompiledModule::cast(prev->value())->reset_weak_next_instance();
         } else {
           WasmCompiledModule::cast(prev->value())
               ->set_ptr_to_weak_next_instance(next);
         }
       }
       if (next != nullptr) {
         DCHECK(!next->cleared());
         if (prev == nullptr) {
           WasmCompiledModule::cast(next->value())->reset_weak_prev_instance();
         } else {
           WasmCompiledModule::cast(next->value())
               ->set_ptr_to_weak_prev_instance(prev);
         }
       }
     }
     TRACE("chain after {\n");
-    TRACE_CHAIN(WasmCompiledModule::cast(wasm_module->GetEmbedderField(0)));
+    TRACE_CHAIN(wasm_module->compiled_module());
     TRACE("}\n");
   }
   compiled_module->reset_weak_owning_instance();
   GlobalHandles::Destroy(reinterpret_cast<Object**>(p));
   TRACE("}\n");
 }
 
 int AdvanceSourcePositionTableIterator(SourcePositionTableIterator& iterator,
                                        int offset) {
   DCHECK(!iterator.done());
@@ skipping 226 matching lines @@
   if (!function.is_null()) {
     wasm_function = GetWasmFunctionForImportWrapper(isolate, function);
     code = UnwrapImportWrapper(function);
     value = Handle<Object>::cast(function);
   }
 
   UpdateDispatchTables(isolate, dispatch_tables, index, wasm_function, code);
   array->set(index, *value);
 }
 
-bool wasm::IsWasmInstance(Object* object) {
-  return WasmInstanceObject::IsWasmInstanceObject(object);
-}
-
 Handle<Script> wasm::GetScript(Handle<JSObject> instance) {
   WasmCompiledModule* compiled_module =
       WasmInstanceObject::cast(*instance)->compiled_module();
   return handle(compiled_module->script());
 }
 
 bool wasm::IsWasmCodegenAllowed(Isolate* isolate, Handle<Context> context) {
   // TODO(wasm): Once wasm has its own CSP policy, we should introduce a
   // separate callback that includes information about the module about to be
   // compiled. For the time being, pass an empty string as placeholder for the
@@ skipping 38 matching lines @@
   WasmCompiledModule* compiled_module = module_obj->compiled_module();
   CHECK_EQ(JSObject::cast(compiled_module->ptr_to_weak_wasm_module()->value()),
            *module_obj);
   Object* prev = nullptr;
   int found_instances = compiled_module->has_weak_owning_instance() ? 1 : 0;
   WasmCompiledModule* current_instance = compiled_module;
   while (current_instance->has_weak_next_instance()) {
     CHECK((prev == nullptr && !current_instance->has_weak_prev_instance()) ||
           current_instance->ptr_to_weak_prev_instance()->value() == prev);
     CHECK_EQ(current_instance->ptr_to_weak_wasm_module()->value(), *module_obj);
-    CHECK(IsWasmInstance(
-        current_instance->ptr_to_weak_owning_instance()->value()));
+    CHECK(current_instance->ptr_to_weak_owning_instance()
+              ->value()
+              ->IsWasmInstanceObject());
     prev = current_instance;
     current_instance = WasmCompiledModule::cast(
         current_instance->ptr_to_weak_next_instance()->value());
     ++found_instances;
     CHECK_LE(found_instances, instance_count);
   }
   CHECK_EQ(found_instances, instance_count);
 }
 
 void testing::ValidateModuleState(Isolate* isolate,
@@ skipping 623 matching lines @@
                                      callee_compiled->instruction_start());
     }
     DCHECK_EQ(non_compiled_functions.size(), idx);
   }
 
   Code* ret =
       Code::cast(compiled_module->code_table()->get(func_to_return_idx));
   DCHECK_EQ(Code::WASM_FUNCTION, ret->kind());
   return handle(ret, isolate);
 }