[wasm] Remove obsolete {weak_exported_functions} field.

R=clemensh@chromium.org

Change-Id: I51e4210334a50ebb9ed7172c112083d6c3d784d9
Reviewed-on: https://chromium-review.googlesource.com/1000776Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52477}

src/objects-debug.cc

@@ -1504,7 +1504,6 @@ void WasmCompiledModule::WasmCompiledModuleVerify() {
   VerifyObjectField(kSharedOffset);
   VerifyObjectField(kNativeContextOffset);
   VerifyObjectField(kExportWrappersOffset);
-  VerifyObjectField(kWeakExportedFunctionsOffset);
   VerifyObjectField(kNextInstanceOffset);
   VerifyObjectField(kPrevInstanceOffset);
   VerifyObjectField(kOwningInstanceOffset);

src/wasm/module-compiler.cc

@@ -2165,22 +2165,8 @@ void InstanceBuilder::ProcessExports(
   desc.set_enumerable(true);
   desc.set_configurable(module_->is_asm_js());
 
-  // Store weak references to all exported functions.
-  Handle<FixedArray> weak_exported_functions;
-  if (compiled_module->has_weak_exported_functions()) {
-    weak_exported_functions =
-        handle(compiled_module->weak_exported_functions(), isolate_);
-  } else {
-    int export_count = 0;
-    for (WasmExport& exp : module_->export_table) {
-      if (exp.kind == kExternalFunction) ++export_count;
-    }
-    weak_exported_functions = isolate_->factory()->NewFixedArray(export_count);
-    compiled_module->set_weak_exported_functions(*weak_exported_functions);
-  }
-
   // Process each export in the export table.
-  int export_index = 0;  // Index into {weak_exported_functions}.
+  int export_index = 0;  // Index into {export_wrappers}.
   for (WasmExport& exp : module_->export_table) {
     Handle<String> name =
         WasmSharedModuleData::ExtractUtf8StringFromModuleBytes(
@@ -2221,10 +2207,6 @@ void InstanceBuilder::ProcessExports(
           js_wrappers_[exp.index] = js_function;
         }
         desc.set_value(js_function);
-        Handle<WeakCell> weak_export =
-            isolate_->factory()->NewWeakCell(js_function);
-        DCHECK_GT(weak_exported_functions->length(), export_index);
-        weak_exported_functions->set(export_index, *weak_export);
         export_index++;
         break;
       }
@@ -2289,7 +2271,7 @@ void InstanceBuilder::ProcessExports(
       return;
     }
   }
-  DCHECK_EQ(export_index, weak_exported_functions->length());
+  DCHECK_EQ(export_index, export_wrappers->length());
 
   if (module_->is_wasm()) {
     v8::Maybe<bool> success =

src/wasm/wasm-debug.cc

@@ -612,12 +612,9 @@ void RedirectCallsitesInInstance(Isolate* isolate, WasmInstanceObject* instance,
   // TODO(6668): Find instances that imported our code and also patch those.
 
   // Redirect all calls in exported functions.
-  FixedArray* weak_exported_functions =
-      instance->compiled_module()->weak_exported_functions();
-  for (int i = 0, e = weak_exported_functions->length(); i != e; ++i) {
-    WeakCell* weak_function = WeakCell::cast(weak_exported_functions->get(i));
-    if (weak_function->cleared()) continue;
-    Code* code = JSFunction::cast(weak_function->value())->code();
+  FixedArray* export_wrapper = instance->compiled_module()->export_wrappers();
+  for (int i = 0, e = export_wrapper->length(); i != e; ++i) {
+    Code* code = Code::cast(export_wrapper->get(i));
     RedirectCallsitesInJSWrapperCode(isolate, code, map);
   }
 }

src/wasm/wasm-objects-inl.h

@@ -170,7 +170,6 @@ OPTIONAL_ACCESSORS(WasmDebugInfo, c_wasm_entry_map, Managed<wasm::SignatureMap>,
 WCM_OBJECT(WasmSharedModuleData, shared, kSharedOffset)
 WCM_WEAK_LINK(Context, native_context, kNativeContextOffset)
 WCM_OBJECT(FixedArray, export_wrappers, kExportWrappersOffset)
-WCM_OBJECT(FixedArray, weak_exported_functions, kWeakExportedFunctionsOffset)
 WCM_OBJECT(WasmCompiledModule, next_instance, kNextInstanceOffset)
 WCM_OBJECT(WasmCompiledModule, prev_instance, kPrevInstanceOffset)
 WCM_WEAK_LINK(WasmInstanceObject, owning_instance, kOwningInstanceOffset)

src/wasm/wasm-objects.h

@@ -473,7 +473,6 @@ class WasmCompiledModule : public Struct {
   V(kSharedOffset, kPointerSize)                \
   V(kNativeContextOffset, kPointerSize)         \
   V(kExportWrappersOffset, kPointerSize)        \
-  V(kWeakExportedFunctionsOffset, kPointerSize) \
   V(kNextInstanceOffset, kPointerSize)          \
   V(kPrevInstanceOffset, kPointerSize)          \
   V(kOwningInstanceOffset, kPointerSize)        \
@@ -520,8 +519,7 @@ class WasmCompiledModule : public Struct {
   // we embed the generated code with a value, then we track that value here.
   WCM_OBJECT(WasmSharedModuleData, shared)
   WCM_WEAK_LINK(Context, native_context)
-  WCM_CONST_OBJECT(FixedArray, export_wrappers)
-  WCM_OBJECT(FixedArray, weak_exported_functions)
+  WCM_OBJECT(FixedArray, export_wrappers)
   WCM_CONST_OBJECT(WasmCompiledModule, next_instance)
   WCM_CONST_OBJECT(WasmCompiledModule, prev_instance)
   WCM_WEAK_LINK(WasmInstanceObject, owning_instance)

test/cctest/wasm/wasm-run-utils.cc

@@ -133,15 +133,13 @@ Handle<JSFunction> TestingModuleBuilder::WrapCode(uint32_t index) {
       static_cast<int>(test_module_.functions[index].sig->parameter_count()),
       ret_code);
 
-  // Add weak reference to exported functions.
-  Handle<FixedArray> old_arr(compiled_module->weak_exported_functions(),
-                             isolate_);
+  // Add reference to the exported wrapper code.
+  Handle<FixedArray> old_arr(compiled_module->export_wrappers(), isolate_);
   Handle<FixedArray> new_arr =
       isolate_->factory()->NewFixedArray(old_arr->length() + 1);
   old_arr->CopyTo(0, *new_arr, 0, old_arr->length());
-  Handle<WeakCell> weak_fn = isolate_->factory()->NewWeakCell(ret);
-  new_arr->set(old_arr->length(), *weak_fn);
-  compiled_module->set_weak_exported_functions(*new_arr);
+  new_arr->set(old_arr->length(), *ret_code);
+  compiled_module->set_export_wrappers(*new_arr);
 
   return ret;
 }
@@ -232,8 +230,6 @@ Handle<WasmInstanceObject> TestingModuleBuilder::InitInstanceObject() {
   // interpreter when we get a memory. We do have globals, though.
   native_module_ = compiled_module->GetNativeModule();
 
-  Handle<FixedArray> weak_exported = isolate_->factory()->NewFixedArray(0);
-  compiled_module->set_weak_exported_functions(*weak_exported);
   DCHECK(compiled_module->IsWasmCompiledModule());
   script->set_wasm_compiled_module(*compiled_module);
   auto instance = WasmInstanceObject::New(isolate_, compiled_module);

test/unittests/wasm/module-decoder-unittest.cc

@@ -1803,13 +1803,6 @@ class WasmModuleCustomSectionTest : public TestWithIsolateAndZone {
  public:
   void CheckSections(const byte* module_start, const byte* module_end,
                      const CustomSectionOffset* expected, size_t num_expected) {
-    // Add the WASM magic and version number automatically.
-    size_t size = static_cast<size_t>(module_end - module_start);
-    byte header[] = {WASM_MODULE_HEADER};
-    size_t total = sizeof(header) + size;
-    auto temp = new byte[total];
-    memcpy(temp, header, sizeof(header));
-    memcpy(temp + sizeof(header), module_start, size);
     std::vector<CustomSectionOffset> custom_sections =
         DecodeCustomSections(module_start, module_end);