Revert of [modules] Basic support of exports (patchset #10 id:180001 of...

Revert of [modules] Basic support of exports (patchset #10 id:180001 of https://codereview.chromium.org/2302783002/ )

Reason for revert:
Failures related to deopt.

Original issue's description:
> [modules] Basic support of exports
>
> This adds partial support of exports to the runtime system and
> to the interpreter. It introduces a new HeapObject JSModule that
> maps each of the module's export names to a Cell containing the
> exported value.
>
> Several aspects of this implementation are subject to change in
> follow-up CLs.
>
> BUG=v8:1569
>
> Committed: https://crrev.com/241a0412eed919395a2e163b30b9b66071ce5c17
> Cr-Commit-Position: refs/heads/master@{#39341}

TBR=adamk@chromium.org,rmcilroy@chromium.org,ulan@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:1569

Review-Url: https://codereview.chromium.org/2328283002
Cr-Commit-Position: refs/heads/master@{#39345}

src/api.cc

@@ -1846,22 +1846,11 @@ MaybeLocal<Value> Script::Run(Local<Context> context) {
   i::TimerEventScope<i::TimerEventExecute> timer_scope(isolate);
   TRACE_EVENT_CALL_STATS_SCOPED(isolate, "v8", "V8.Execute");
   auto fun = i::Handle<i::JSFunction>::cast(Utils::OpenHandle(this));
-
-  i::Handle<i::Object> receiver;
+  i::Handle<i::Object> receiver = isolate->global_proxy();
   Local<Value> result;
-
-  if (fun->shared()->scope_info()->scope_type() == i::MODULE_SCOPE) {
-    receiver = isolate->factory()->undefined_value();
-    i::Handle<i::Object> argv[] = {
-        handle(isolate->native_context()->current_module())};
-    has_pending_exception = !ToLocal<Value>(
-        i::Execution::Call(isolate, fun, receiver, 1, argv), &result);
-  } else {
-    receiver = isolate->global_proxy();
-    has_pending_exception = !ToLocal<Value>(
-        i::Execution::Call(isolate, fun, receiver, 0, nullptr), &result);
-  }
-
+  has_pending_exception =
+      !ToLocal<Value>(i::Execution::Call(isolate, fun, receiver, 0, NULL),
+                      &result);
   RETURN_ON_FAILED_EXECUTION(Value);
   RETURN_ESCAPED(result);
 }
@@ -2002,34 +1991,7 @@ MaybeLocal<Script> ScriptCompiler::CompileModule(Local<Context> context,
   Local<UnboundScript> generic;
   if (!maybe.ToLocal(&generic)) return MaybeLocal<Script>();
   v8::Context::Scope scope(context);
-  auto result = generic->BindToCurrentContext();
-
-  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
-  i::Handle<i::JSModule> module = i_isolate->factory()->NewJSModule();
-  // TODO(neis): Storing the module into the native context is a temporary hack
-  // to pass it to the Script::Run function.  This will be removed once we
-  // support modules in the API.
-  i_isolate->native_context()->set_current_module(*module);
-
-  i::Handle<i::SharedFunctionInfo> shared =
-      i::Handle<i::SharedFunctionInfo>::cast(Utils::OpenHandle(*generic));
-  i::Handle<i::FixedArray> regular_exports =
-      i::handle(shared->scope_info()->ModuleDescriptorInfo()->regular_exports(),
-                i_isolate);
-  // TODO(neis): This will create multiple cells for the same local variable if
-  // exported under multiple names, which is wrong but cannot be observed at the
-  // moment. This will be fixed by doing the full-fledged linking here once we
-  // get there.
-  for (int i = 0; i < regular_exports->length(); ++i) {
-    i::Handle<i::ModuleInfoEntry> entry =
-        i::handle(i::ModuleInfoEntry::cast(regular_exports->get(i)), i_isolate);
-    DCHECK(entry->import_name()->IsUndefined(i_isolate));
-    i::Handle<i::String> export_name =
-        handle(i::String::cast(entry->export_name()), i_isolate);
-    i::JSModule::CreateExport(module, export_name);
-  }
-
-  return result;
+  return generic->BindToCurrentContext();
 }
 
 

src/ast/ast.h

@@ -3378,12 +3378,11 @@ class AstNodeFactory final BASE_EMBEDDED {
   // the Function constructor.
   FunctionLiteral* NewScriptOrEvalFunctionLiteral(
       DeclarationScope* scope, ZoneList<Statement*>* body,
-      int materialized_literal_count, int expected_property_count,
-      int parameter_count) {
+      int materialized_literal_count, int expected_property_count) {
     return new (zone_) FunctionLiteral(
         zone_, ast_value_factory_->empty_string(), ast_value_factory_, scope,
-        body, materialized_literal_count, expected_property_count,
-        parameter_count, FunctionLiteral::kAnonymousExpression,
+        body, materialized_literal_count, expected_property_count, 0,
+        FunctionLiteral::kAnonymousExpression,
         FunctionLiteral::kNoDuplicateParameters,
         FunctionLiteral::kShouldLazyCompile, FunctionKind::kNormalFunction, 0,
         false);

src/ast/modules.cc

@@ -87,28 +87,27 @@ const AstRawString* FromStringOrUndefined(Isolate* isolate,
 
 }  // namespace
 
-Handle<ModuleInfoEntry> ModuleDescriptor::Entry::Serialize(
-    Isolate* isolate) const {
-  return ModuleInfoEntry::New(isolate,
-                              ToStringOrUndefined(isolate, export_name),
-                              ToStringOrUndefined(isolate, local_name),
-                              ToStringOrUndefined(isolate, import_name),
-                              ToStringOrUndefined(isolate, module_request));
+Handle<FixedArray> ModuleDescriptor::Entry::Serialize(Isolate* isolate) const {
+  Handle<FixedArray> result = isolate->factory()->NewFixedArray(4);
+  result->set(0, *ToStringOrUndefined(isolate, export_name));
+  result->set(1, *ToStringOrUndefined(isolate, local_name));
+  result->set(2, *ToStringOrUndefined(isolate, import_name));
+  result->set(3, *ToStringOrUndefined(isolate, module_request));
+  return result;
 }
 
 ModuleDescriptor::Entry* ModuleDescriptor::Entry::Deserialize(
-    Isolate* isolate, AstValueFactory* avfactory,
-    Handle<ModuleInfoEntry> entry) {
-  Entry* result = new (avfactory->zone()) Entry(Scanner::Location::invalid());
-  result->export_name = FromStringOrUndefined(
-      isolate, avfactory, handle(entry->export_name(), isolate));
-  result->local_name = FromStringOrUndefined(
-      isolate, avfactory, handle(entry->local_name(), isolate));
-  result->import_name = FromStringOrUndefined(
-      isolate, avfactory, handle(entry->import_name(), isolate));
-  result->module_request = FromStringOrUndefined(
-      isolate, avfactory, handle(entry->module_request(), isolate));
-  return result;
+    Isolate* isolate, AstValueFactory* avfactory, Handle<FixedArray> data) {
+  Entry* entry = new (avfactory->zone()) Entry(Scanner::Location::invalid());
+  entry->export_name =
+      FromStringOrUndefined(isolate, avfactory, handle(data->get(0), isolate));
+  entry->local_name =
+      FromStringOrUndefined(isolate, avfactory, handle(data->get(1), isolate));
+  entry->import_name =
+      FromStringOrUndefined(isolate, avfactory, handle(data->get(2), isolate));
+  entry->module_request =
+      FromStringOrUndefined(isolate, avfactory, handle(data->get(3), isolate));
+  return entry;
 }
 
 void ModuleDescriptor::MakeIndirectExportsExplicit(Zone* zone) {

src/ast/modules.h

@@ -14,7 +14,7 @@ namespace internal {
 
 
 class AstRawString;
-class ModuleInfoEntry;
+
 
 class ModuleDescriptor : public ZoneObject {
  public:
@@ -80,7 +80,6 @@ class ModuleDescriptor : public ZoneObject {
     const AstRawString* import_name;
     const AstRawString* module_request;
 
-    // TODO(neis): Remove local_name component?
     explicit Entry(Scanner::Location loc)
         : location(loc),
           export_name(nullptr),
@@ -88,12 +87,9 @@ class ModuleDescriptor : public ZoneObject {
           import_name(nullptr),
           module_request(nullptr) {}
 
-    // (De-)serialization support.
-    // Note that the location value is not preserved as it's only needed by the
-    // parser.  (A Deserialize'd entry has an invalid location.)
-    Handle<ModuleInfoEntry> Serialize(Isolate* isolate) const;
+    Handle<FixedArray> Serialize(Isolate* isolate) const;
     static Entry* Deserialize(Isolate* isolate, AstValueFactory* avfactory,
-                              Handle<ModuleInfoEntry> entry);
+                              Handle<FixedArray> data);
   };
 
   // Empty imports and namespace imports.

src/ast/scopeinfo.cc

@@ -517,7 +517,7 @@ ScopeInfo* ScopeInfo::OuterScopeInfo() {
 
 ModuleInfo* ScopeInfo::ModuleDescriptorInfo() {
   DCHECK(scope_type() == MODULE_SCOPE);
-  return ModuleInfo::cast(get(ModuleInfoIndex()));
+  return static_cast<ModuleInfo*>(get(ModuleInfoIndex()));
 }
 
 String* ScopeInfo::ParameterName(int var) {
@@ -811,26 +811,12 @@ void ScopeInfo::Print() {
     PrintList("context slots", Context::MIN_CONTEXT_SLOTS,
               ContextLocalNamesIndex(),
               ContextLocalNamesIndex() + ContextLocalCount(), this);
-    // TODO(neis): Print module stuff if present.
   }
 
   PrintF("}\n");
 }
 #endif  // DEBUG
 
-Handle<ModuleInfoEntry> ModuleInfoEntry::New(Isolate* isolate,
-                                             Handle<Object> export_name,
-                                             Handle<Object> local_name,
-                                             Handle<Object> import_name,
-                                             Handle<Object> module_request) {
-  Handle<ModuleInfoEntry> result = isolate->factory()->NewModuleInfoEntry();
-  result->set(kExportNameIndex, *export_name);
-  result->set(kLocalNameIndex, *local_name);
-  result->set(kImportNameIndex, *import_name);
-  result->set(kModuleRequestIndex, *module_request);
-  return result;
-}
-
 Handle<ModuleInfo> ModuleInfo::New(Isolate* isolate, ModuleDescriptor* descr) {
   // Serialize special exports.
   Handle<FixedArray> special_exports =

src/ast/scopes.cc

@@ -171,8 +171,8 @@ ModuleScope::ModuleScope(Isolate* isolate, Handle<ScopeInfo> scope_info,
   // Deserialize special exports.
   Handle<FixedArray> special_exports = handle(module_info->special_exports());
   for (int i = 0, n = special_exports->length(); i < n; ++i) {
-    Handle<ModuleInfoEntry> serialized_entry(
-        ModuleInfoEntry::cast(special_exports->get(i)), isolate);
+    Handle<FixedArray> serialized_entry(
+        FixedArray::cast(special_exports->get(i)), isolate);
     module_descriptor_->AddSpecialExport(
         ModuleDescriptor::Entry::Deserialize(isolate, avfactory,
                                              serialized_entry),
@@ -182,8 +182,8 @@ ModuleScope::ModuleScope(Isolate* isolate, Handle<ScopeInfo> scope_info,
   // Deserialize regular exports.
   Handle<FixedArray> regular_exports = handle(module_info->regular_exports());
   for (int i = 0, n = regular_exports->length(); i < n; ++i) {
-    Handle<ModuleInfoEntry> serialized_entry(
-        ModuleInfoEntry::cast(regular_exports->get(i)), isolate);
+    Handle<FixedArray> serialized_entry(
+        FixedArray::cast(regular_exports->get(i)), isolate);
     module_descriptor_->AddRegularExport(ModuleDescriptor::Entry::Deserialize(
         isolate, avfactory, serialized_entry));
   }
@@ -829,7 +829,7 @@ Variable* DeclarationScope::DeclareParameter(
     const AstRawString* name, VariableMode mode, bool is_optional, bool is_rest,
     bool* is_duplicate, AstValueFactory* ast_value_factory) {
   DCHECK(!already_resolved_);
-  DCHECK(is_function_scope() || is_module_scope());
+  DCHECK(is_function_scope());
   DCHECK(!has_rest_);
   DCHECK(!is_optional || !is_rest);
   Variable* var;
@@ -1164,16 +1164,6 @@ DeclarationScope* Scope::GetClosureScope() {
   return scope->AsDeclarationScope();
 }
 
-ModuleScope* Scope::GetModuleScope() {
-  Scope* scope = this;
-  DCHECK(!scope->is_script_scope());
-  while (!scope->is_module_scope()) {
-    scope = scope->outer_scope();
-    DCHECK_NOT_NULL(scope);
-  }
-  return scope->AsModuleScope();
-}
-
 DeclarationScope* Scope::GetReceiverScope() {
   Scope* scope = this;
   while (!scope->is_script_scope() &&

src/ast/scopes.h

@@ -371,9 +371,6 @@ class Scope: public ZoneObject {
   // 'this' is bound, and what determines the function kind.
   DeclarationScope* GetReceiverScope();
 
-  // Find the module scope, assuming there is one.
-  ModuleScope* GetModuleScope();
-
   // Analyze() must have been called once to create the ScopeInfo.
   Handle<ScopeInfo> scope_info() {
     DCHECK(!scope_info_.is_null());
@@ -680,9 +677,9 @@ class DeclarationScope : public Scope {
   }
 
   // Parameters. The left-most parameter has index 0.
-  // Only valid for function and module scopes.
+  // Only valid for function scopes.
   Variable* parameter(int index) const {
-    DCHECK(is_function_scope() || is_module_scope());
+    DCHECK(is_function_scope());
     return params_[index];
   }
 

src/ast/variables.h

@@ -102,11 +102,6 @@ class Variable final : public ZoneObject {
 
   int index() const { return index_; }
 
-  bool IsExport() const {
-    DCHECK(location() == VariableLocation::MODULE);
-    return index() == 0;
-  }
-
   void AllocateTo(VariableLocation location, int index) {
     DCHECK(IsUnallocated() ||
            (this->location() == location && this->index() == index));

src/contexts.cc

@@ -57,8 +57,7 @@ bool ScriptContextTable::Lookup(Handle<ScriptContextTable> table,
 
 
 bool Context::is_declaration_context() {
-  if (IsFunctionContext() || IsNativeContext() || IsScriptContext() ||
-      IsModuleContext()) {
+  if (IsFunctionContext() || IsNativeContext() || IsScriptContext()) {
     return true;
   }
   if (!IsBlockContext()) return false;
@@ -124,13 +123,6 @@ ScopeInfo* Context::scope_info() {
   return ScopeInfo::cast(object);
 }
 
-JSModule* Context::module() {
-  Context* current = this;
-  while (!current->IsModuleContext()) {
-    current = current->previous();
-  }
-  return JSModule::cast(current->extension());
-}
 
 String* Context::catch_name() {
   DCHECK(IsCatchContext());
@@ -197,7 +189,6 @@ Handle<Object> Context::Lookup(Handle<String> name, ContextLookupFlags flags,
                                int* index, PropertyAttributes* attributes,
                                InitializationFlag* init_flag,
                                VariableMode* variable_mode) {
-  DCHECK(!IsModuleContext());
   Isolate* isolate = GetIsolate();
   Handle<Context> context(this, isolate);
 

src/contexts.h

@@ -227,7 +227,6 @@ enum ContextLookupFlags {
   V(UINT8_ARRAY_FUN_INDEX, JSFunction, uint8_array_fun)                        \
   V(UINT8_CLAMPED_ARRAY_FUN_INDEX, JSFunction, uint8_clamped_array_fun)        \
   V(UINT8X16_FUNCTION_INDEX, JSFunction, uint8x16_function)                    \
-  V(CURRENT_MODULE_INDEX, JSModule, current_module)                            \
   NATIVE_CONTEXT_INTRINSIC_FUNCTIONS(V)                                        \
   NATIVE_CONTEXT_IMPORTED_FIELDS(V)
 
@@ -399,10 +398,6 @@ class Context: public FixedArray {
   ScopeInfo* scope_info();
   String* catch_name();
 
-  // Find the module context (assuming there is one) and return the associated
-  // module object.
-  JSModule* module();
-
   // Get the context where var declarations will be hoisted to, which
   // may be the context itself.
   Context* declaration_context();

src/debug/debug-scopes.cc

@@ -362,7 +362,7 @@ bool ScopeIterator::SetVariableValue(Handle<String> variable_name,
     case ScopeIterator::ScopeTypeEval:
       return SetInnerScopeVariableValue(variable_name, new_value);
     case ScopeIterator::ScopeTypeModule:
-      // TODO(neis): Implement.
+      // TODO(2399): should we implement it?
       break;
   }
   return false;
@@ -617,8 +617,6 @@ MaybeHandle<JSObject> ScopeIterator::MaterializeModuleScope() {
   // Fill all context locals.
   CopyContextLocalsToScopeObject(scope_info, context, module_scope);
 
-  // TODO(neis): Also collect stack locals as well as imports and exports.
-
   return module_scope;
 }
 

src/factory.cc

@@ -789,19 +789,15 @@ Handle<ScriptContextTable> Factory::NewScriptContextTable() {
   return context_table;
 }
 
-Handle<Context> Factory::NewModuleContext(Handle<JSModule> module,
-                                          Handle<JSFunction> function,
-                                          Handle<ScopeInfo> scope_info) {
+
+Handle<Context> Factory::NewModuleContext(Handle<ScopeInfo> scope_info) {
   DCHECK_EQ(scope_info->scope_type(), MODULE_SCOPE);
   Handle<FixedArray> array =
       NewFixedArray(scope_info->ContextLength(), TENURED);
   array->set_map_no_write_barrier(*module_context_map());
+  // Instance link will be set later.
   Handle<Context> context = Handle<Context>::cast(array);
-  context->set_closure(*function);
-  context->set_previous(function->context());
-  context->set_extension(*module);
-  context->set_native_context(function->native_context());
-  DCHECK(context->IsModuleContext());
+  context->set_extension(*the_hole_value());
   return context;
 }
 
@@ -1402,16 +1398,11 @@ Handle<ScopeInfo> Factory::NewScopeInfo(int length) {
   return scope_info;
 }
 
-Handle<ModuleInfoEntry> Factory::NewModuleInfoEntry() {
-  Handle<FixedArray> array = NewFixedArray(ModuleInfoEntry::kLength, TENURED);
-  array->set_map_no_write_barrier(*module_info_entry_map());
-  return Handle<ModuleInfoEntry>::cast(array);
-}
-
 Handle<ModuleInfo> Factory::NewModuleInfo() {
   Handle<FixedArray> array = NewFixedArray(ModuleInfo::kLength, TENURED);
   array->set_map_no_write_barrier(*module_info_map());
-  return Handle<ModuleInfo>::cast(array);
+  Handle<ModuleInfo> module_info = Handle<ModuleInfo>::cast(array);
+  return module_info;
 }
 
 Handle<JSObject> Factory::NewExternal(void* value) {
@@ -1704,11 +1695,6 @@ Handle<JSGeneratorObject> Factory::NewJSGeneratorObject(
       JSGeneratorObject);
 }
 
-Handle<JSModule> Factory::NewJSModule() {
-  Handle<JSModule> module =
-      Handle<JSModule>::cast(NewJSObjectFromMap(js_module_map(), TENURED));
-  return module;
-}
 
 Handle<JSArrayBuffer> Factory::NewJSArrayBuffer(SharedFlag shared,
                                                 PretenureFlag pretenure) {

src/factory.h

@@ -257,9 +257,7 @@ class Factory final {
   Handle<ScriptContextTable> NewScriptContextTable();
 
   // Create a module context.
-  Handle<Context> NewModuleContext(Handle<JSModule> module,
-                                   Handle<JSFunction> function,
-                                   Handle<ScopeInfo> scope_info);
+  Handle<Context> NewModuleContext(Handle<ScopeInfo> scope_info);
 
   // Create a function context.
   Handle<Context> NewFunctionContext(int length, Handle<JSFunction> function);
@@ -477,8 +475,6 @@ class Factory final {
 
   Handle<JSGeneratorObject> NewJSGeneratorObject(Handle<JSFunction> function);
 
-  Handle<JSModule> NewJSModule();
-
   Handle<JSArrayBuffer> NewJSArrayBuffer(
       SharedFlag shared = SharedFlag::kNotShared,
       PretenureFlag pretenure = NOT_TENURED);
@@ -563,7 +559,6 @@ class Factory final {
   // Create a serialized scope info.
   Handle<ScopeInfo> NewScopeInfo(int length);
 
-  Handle<ModuleInfoEntry> NewModuleInfoEntry();
   Handle<ModuleInfo> NewModuleInfo();
 
   // Create an External object for V8's external API.

src/heap/heap.cc

@@ -2307,9 +2307,7 @@ bool Heap::CreateInitialMaps() {
     DCHECK_NE(fixed_array_map(), fixed_cow_array_map());
 
     ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, scope_info)
-    ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, module_info_entry)
     ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, module_info)
-    ALLOCATE_MAP(JS_MODULE_TYPE, JSModule::kSize, js_module)
     ALLOCATE_PRIMITIVE_MAP(HEAP_NUMBER_TYPE, HeapNumber::kSize, heap_number,
                            Context::NUMBER_FUNCTION_INDEX)
     ALLOCATE_MAP(MUTABLE_HEAP_NUMBER_TYPE, HeapNumber::kSize,

src/heap/heap.h

@@ -48,9 +48,7 @@ using v8::MemoryPressureLevel;
   V(Map, one_byte_string_map, OneByteStringMap)                                \
   V(Map, one_byte_internalized_string_map, OneByteInternalizedStringMap)       \
   V(Map, scope_info_map, ScopeInfoMap)                                         \
-  V(Map, module_info_entry_map, ModuleInfoEntryMap)                            \
   V(Map, module_info_map, ModuleInfoMap)                                       \
-  V(Map, js_module_map, JSModuleMap)                                           \
   V(Map, shared_function_info_map, SharedFunctionInfoMap)                      \
   V(Map, code_map, CodeMap)                                                    \
   V(Map, function_context_map, FunctionContextMap)                             \
@@ -277,9 +275,7 @@ using v8::MemoryPressureLevel;
   V(FixedArrayMap)                      \
   V(CodeMap)                            \
   V(ScopeInfoMap)                       \
-  V(ModuleInfoEntryMap)                 \
   V(ModuleInfoMap)                      \
-  V(JSModuleMap)                        \
   V(FixedCOWArrayMap)                   \
   V(FixedDoubleArrayMap)                \
   V(WeakCellMap)                        \

src/interpreter/bytecode-generator.cc

@@ -743,6 +743,7 @@ void BytecodeGenerator::GenerateBytecode(uintptr_t stack_limit) {
     VisitGeneratorPrologue();
   }
 
+  // Build function context only if there are context allocated variables.
   if (scope()->NeedsContext()) {
     // Push a new inner context scope for the function.
     BuildNewLocalActivationContext();
@@ -939,8 +940,7 @@ void BytecodeGenerator::VisitVariableDeclaration(VariableDeclaration* decl) {
       break;
     }
     case VariableLocation::MODULE:
-      // Nothing to do here.
-      break;
+      UNREACHABLE();
   }
 }
 
@@ -979,11 +979,7 @@ void BytecodeGenerator::VisitFunctionDeclaration(FunctionDeclaration* decl) {
       break;
     }
     case VariableLocation::MODULE:
-      DCHECK(variable->mode() == LET);
-      VisitForAccumulatorValue(decl->fun());
-      VisitVariableAssignment(variable, Token::INIT,
-                              FeedbackVectorSlot::Invalid());
-      break;
+      UNREACHABLE();
   }
 }
 
@@ -1982,21 +1978,8 @@ void BytecodeGenerator::VisitVariableLoad(Variable* variable,
       builder()->LoadLookupSlot(variable->name(), typeof_mode);
       break;
     }
-    case VariableLocation::MODULE: {
-      ModuleDescriptor* descriptor = scope()->GetModuleScope()->module();
-      if (variable->IsExport()) {
-        auto it = descriptor->regular_exports().find(variable->raw_name());
-        DCHECK(it != descriptor->regular_exports().end());
-        Register export_name = register_allocator()->NewRegister();
-        builder()
-            ->LoadLiteral(it->second->export_name->string())
-            .StoreAccumulatorInRegister(export_name)
-            .CallRuntime(Runtime::kLoadModuleExport, export_name, 1);
-      } else {
-        UNIMPLEMENTED();
-      }
-      break;
-    }
+    case VariableLocation::MODULE:
+      UNREACHABLE();
   }
   execution_result()->SetResultInAccumulator();
 }
@@ -2194,33 +2177,8 @@ void BytecodeGenerator::VisitVariableAssignment(Variable* variable,
       builder()->StoreLookupSlot(variable->name(), language_mode());
       break;
     }
-    case VariableLocation::MODULE: {
-      DCHECK(IsDeclaredVariableMode(mode));
-
-      if (mode == CONST && op != Token::INIT) {
-        builder()->CallRuntime(Runtime::kThrowConstAssignError, Register(), 0);
-        break;
-      }
-
-      // If we don't throw above, we know that we're dealing with an
-      // export because imports are const and we do not generate initializing
-      // assignments for them.
-      DCHECK(variable->IsExport());
-
-      ModuleDescriptor* mod = scope()->GetModuleScope()->module();
-      auto it = mod->regular_exports().find(variable->raw_name());
-      DCHECK(it != mod->regular_exports().end());
-
-      register_allocator()->PrepareForConsecutiveAllocations(2);
-      Register export_name = register_allocator()->NextConsecutiveRegister();
-      Register value = register_allocator()->NextConsecutiveRegister();
-      builder()
-          ->StoreAccumulatorInRegister(value)
-          .LoadLiteral(it->second->export_name->string())
-          .StoreAccumulatorInRegister(export_name)
-          .CallRuntime(Runtime::kStoreModuleExport, export_name, 2);
-      break;
-    }
+    case VariableLocation::MODULE:
+      UNREACHABLE();
   }
 }
 
@@ -3177,36 +3135,18 @@ void BytecodeGenerator::BuildNewLocalActivationContext() {
   AccumulatorResultScope accumulator_execution_result(this);
   Scope* scope = this->scope();
 
-  // Create the appropriate context.
+  // Allocate a new local context.
   if (scope->is_script_scope()) {
     RegisterAllocationScope register_scope(this);
-    register_allocator()->PrepareForConsecutiveAllocations(2);
-    Register closure = register_allocator()->NextConsecutiveRegister();
-    Register scope_info = register_allocator()->NextConsecutiveRegister();
+    Register closure = register_allocator()->NewRegister();
+    Register scope_info = register_allocator()->NewRegister();
+    DCHECK(Register::AreContiguous(closure, scope_info));
     builder()
         ->LoadAccumulatorWithRegister(Register::function_closure())
         .StoreAccumulatorInRegister(closure)
         .LoadLiteral(scope->scope_info())
         .StoreAccumulatorInRegister(scope_info)
         .CallRuntime(Runtime::kNewScriptContext, closure, 2);
-  } else if (scope->is_module_scope()) {
-    // We don't need to do anything for the outer script scope.
-    DCHECK(scope->outer_scope()->is_script_scope());
-
-    RegisterAllocationScope register_scope(this);
-    register_allocator()->PrepareForConsecutiveAllocations(3);
-    Register module = register_allocator()->NextConsecutiveRegister();
-    Register closure = register_allocator()->NextConsecutiveRegister();
-    Register scope_info = register_allocator()->NextConsecutiveRegister();
-    // A JSFunction representing a module is called with the module object as
-    // its sole argument, which we pass on to PushModuleContext.
-    builder()
-        ->MoveRegister(builder()->Parameter(1), module)
-        .LoadAccumulatorWithRegister(Register::function_closure())
-        .StoreAccumulatorInRegister(closure)
-        .LoadLiteral(scope->scope_info())
-        .StoreAccumulatorInRegister(scope_info)
-        .CallRuntime(Runtime::kPushModuleContext, module, 3);
   } else {
     int slot_count = scope->num_heap_slots() - Context::MIN_CONTEXT_SLOTS;
     builder()->CreateFunctionContext(slot_count);
@@ -3353,7 +3293,8 @@ void BytecodeGenerator::VisitFunctionClosureForContext() {
   AccumulatorResultScope accumulator_execution_result(this);
   DeclarationScope* closure_scope =
       execution_context()->scope()->GetClosureScope();
-  if (closure_scope->is_script_scope()) {
+  if (closure_scope->is_script_scope() ||
+      closure_scope->is_module_scope()) {
     // Contexts nested in the native context have a canonical empty function as
     // their closure, not the anonymous closure containing the global code.
     Register native_context = register_allocator()->NewRegister();
@@ -3369,8 +3310,7 @@ void BytecodeGenerator::VisitFunctionClosureForContext() {
     builder()->LoadContextSlot(execution_context()->reg(),
                                Context::CLOSURE_INDEX);
   } else {
-    DCHECK(closure_scope->is_function_scope() ||
-           closure_scope->is_module_scope());
+    DCHECK(closure_scope->is_function_scope());
     builder()->LoadAccumulatorWithRegister(Register::function_closure());
   }
   execution_result()->SetResultInAccumulator();

src/objects-debug.cc

@@ -166,9 +166,6 @@ void HeapObject::HeapObjectVerify() {
     case JS_PROXY_TYPE:
       JSProxy::cast(this)->JSProxyVerify();
       break;
-    case JS_MODULE_TYPE:
-      JSModule::cast(this)->JSModuleVerify();
-      break;
     case FOREIGN_TYPE:
       Foreign::cast(this)->ForeignVerify();
       break;
@@ -834,7 +831,6 @@ void JSRegExp::JSRegExpVerify() {
   }
 }
 
-void JSModule::JSModuleVerify() { CHECK(IsJSModule()); }
 
 void JSProxy::JSProxyVerify() {
   CHECK(IsJSProxy());

src/objects-inl.h

@@ -793,10 +793,6 @@ bool HeapObject::IsScopeInfo() const {
   return map() == GetHeap()->scope_info_map();
 }
 
-bool HeapObject::IsModuleInfoEntry() const {
-  return map() == GetHeap()->module_info_entry_map();
-}
-
 bool HeapObject::IsModuleInfo() const {
   return map() == GetHeap()->module_info_map();
 }
@@ -3276,7 +3272,6 @@ CAST_ACCESSOR(JSGlobalProxy)
 CAST_ACCESSOR(JSMap)
 CAST_ACCESSOR(JSMapIterator)
 CAST_ACCESSOR(JSMessageObject)
-CAST_ACCESSOR(JSModule)
 CAST_ACCESSOR(JSObject)
 CAST_ACCESSOR(JSProxy)
 CAST_ACCESSOR(JSReceiver)
@@ -3290,7 +3285,6 @@ CAST_ACCESSOR(JSWeakMap)
 CAST_ACCESSOR(JSWeakSet)
 CAST_ACCESSOR(LayoutDescriptor)
 CAST_ACCESSOR(Map)
-CAST_ACCESSOR(ModuleInfoEntry)
 CAST_ACCESSOR(ModuleInfo)
 CAST_ACCESSOR(Name)
 CAST_ACCESSOR(NameDictionary)
@@ -6655,8 +6649,6 @@ bool JSGeneratorObject::is_executing() const {
   return continuation() == kGeneratorExecuting;
 }
 
-TYPE_CHECKER(JSModule, JS_MODULE_TYPE)
-
 ACCESSORS(JSValue, value, Object, kValueOffset)
 
 
@@ -7929,16 +7921,6 @@ bool ScopeInfo::HasSimpleParameters() {
 FOR_EACH_SCOPE_INFO_NUMERIC_FIELD(SCOPE_INFO_FIELD_ACCESSORS)
 #undef SCOPE_INFO_FIELD_ACCESSORS
 
-Object* ModuleInfoEntry::export_name() const { return get(kExportNameIndex); }
-
-Object* ModuleInfoEntry::local_name() const { return get(kLocalNameIndex); }
-
-Object* ModuleInfoEntry::import_name() const { return get(kImportNameIndex); }
-
-Object* ModuleInfoEntry::module_request() const {
-  return get(kModuleRequestIndex);
-}
-
 FixedArray* ModuleInfo::special_exports() const {
   return FixedArray::cast(get(kSpecialExportsIndex));
 }

src/objects.cc

@@ -19470,28 +19470,5 @@ bool JSReceiver::HasProxyInPrototype(Isolate* isolate) {
   return false;
 }
 
-void JSModule::CreateExport(Handle<JSModule> module, Handle<String> name) {
-  Isolate* isolate = module->GetIsolate();
-  Handle<Cell> cell =
-      isolate->factory()->NewCell(isolate->factory()->undefined_value());
-  LookupIterator it(module, name);
-  JSObject::CreateDataProperty(&it, cell, Object::THROW_ON_ERROR).ToChecked();
-}
-
-void JSModule::StoreExport(Handle<JSModule> module, Handle<String> name,
-                           Handle<Object> value) {
-  LookupIterator it(module, name);
-  Handle<Cell> cell = Handle<Cell>::cast(JSObject::GetDataProperty(&it));
-  cell->set_value(*value);
-}
-
-Handle<Object> JSModule::LoadExport(Handle<JSModule> module,
-                                    Handle<String> name) {
-  Isolate* isolate = module->GetIsolate();
-  LookupIterator it(module, name);
-  Handle<Cell> cell = Handle<Cell>::cast(JSObject::GetDataProperty(&it));
-  return handle(cell->value(), isolate);
-}
-
 }  // namespace internal
 }  // namespace v8

src/objects.h

@@ -70,7 +70,6 @@
 //         - JSValue
 //           - JSDate
 //         - JSMessageObject
-//         - JSModule
 //       - JSProxy
 //     - FixedArrayBase
 //       - ByteArray
@@ -95,7 +94,6 @@
 //         - TemplateList
 //         - TransitionArray
 //         - ScopeInfo
-//         - ModuleInfoEntry
 //         - ModuleInfo
 //         - ScriptContextTable
 //         - WeakFixedArray
@@ -881,7 +879,6 @@ class LiteralsArray;
 class LookupIterator;
 class FieldType;
 class ModuleDescriptor;
-class ModuleInfoEntry;
 class ModuleInfo;
 class ObjectHashTable;
 class ObjectVisitor;
@@ -964,7 +961,6 @@ template <class C> inline bool Is(Object* obj);
   V(JSObject)                    \
   V(JSContextExtensionObject)    \
   V(JSGeneratorObject)           \
-  V(JSModule)                    \
   V(Map)                         \
   V(DescriptorArray)             \
   V(FrameArray)                  \
@@ -984,7 +980,6 @@ template <class C> inline bool Is(Object* obj);
   V(ScriptContextTable)          \
   V(NativeContext)               \
   V(ScopeInfo)                   \
-  V(ModuleInfoEntry)             \
   V(ModuleInfo)                  \
   V(JSBoundFunction)             \
   V(JSFunction)                  \
@@ -4417,7 +4412,7 @@ class ScopeInfo : public FixedArray {
 
   // The layout of the static part of a ScopeInfo is as follows. Each entry is
   // numeric and occupies one array slot.
-// 1. A set of properties of the scope.
+  // 1. A set of properties of the scope
 // 2. The number of parameters. For non-function scopes this is 0.
 // 3. The number of non-parameter variables allocated on the stack.
 // 4. The number of non-parameter and parameter variables allocated in the
@@ -4535,30 +4530,6 @@ class ScopeInfo : public FixedArray {
   friend class ScopeIterator;
 };
 
-class ModuleInfoEntry : public FixedArray {
- public:
-  DECLARE_CAST(ModuleInfoEntry)
-  static Handle<ModuleInfoEntry> New(Isolate* isolate,
-                                     Handle<Object> export_name,
-                                     Handle<Object> local_name,
-                                     Handle<Object> import_name,
-                                     Handle<Object> module_request);
-  inline Object* export_name() const;
-  inline Object* local_name() const;
-  inline Object* import_name() const;
-  inline Object* module_request() const;
-
- private:
-  friend class Factory;
-  enum {
-    kExportNameIndex,
-    kLocalNameIndex,
-    kImportNameIndex,
-    kModuleRequestIndex,
-    kLength
-  };
-};
-
 // ModuleInfo is to ModuleDescriptor what ScopeInfo is to Scope.
 class ModuleInfo : public FixedArray {
  public:
@@ -6366,7 +6337,6 @@ class Map: public HeapObject {
   inline bool IsJSFunctionMap();
   inline bool IsStringMap();
   inline bool IsJSProxyMap();
-  inline bool IsJSModuleMap();
   inline bool IsJSGlobalProxyMap();
   inline bool IsJSGlobalObjectMap();
   inline bool IsJSTypedArrayMap();
@@ -7844,21 +7814,6 @@ class JSGeneratorObject: public JSObject {
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSGeneratorObject);
 };
 
-// A JSModule object is a mapping from export names to cells
-// This is still very much in flux.
-class JSModule : public JSObject {
- public:
-  DECLARE_CAST(JSModule)
-  DECLARE_VERIFIER(JSModule)
-
-  static const int kSize = JSObject::kHeaderSize;
-
-  static void CreateExport(Handle<JSModule> module, Handle<String> name);
-  static void StoreExport(Handle<JSModule> module, Handle<String> name,
-                          Handle<Object> value);
-  static Handle<Object> LoadExport(Handle<JSModule> module,
-                                   Handle<String> name);
-};
 
 // JSBoundFunction describes a bound function exotic object.
 class JSBoundFunction : public JSObject {

src/parsing/parser.cc

@@ -742,16 +742,6 @@ FunctionLiteral* Parser::DoParseProgram(ParseInfo* info) {
     int beg_pos = scanner()->location().beg_pos;
     parsing_module_ = info->is_module();
     if (parsing_module_) {
-      // Declare the special module parameter.
-      auto name = ast_value_factory()->empty_string();
-      bool is_duplicate;
-      bool is_rest = false;
-      bool is_optional = false;
-      auto var = scope->DeclareParameter(name, VAR, is_optional, is_rest,
-                                         &is_duplicate, ast_value_factory());
-      DCHECK(!is_duplicate);
-      var->AllocateTo(VariableLocation::PARAMETER, 0);
-
       ParseModuleItemList(body, &ok);
       ok = ok &&
            module()->Validate(this->scope()->AsModuleScope(),
@@ -795,10 +785,9 @@ FunctionLiteral* Parser::DoParseProgram(ParseInfo* info) {
 
     if (ok) {
       RewriteDestructuringAssignments();
-      int parameter_count = parsing_module_ ? 1 : 0;
       result = factory()->NewScriptOrEvalFunctionLiteral(
           scope, body, function_state.materialized_literal_count(),
-          function_state.expected_property_count(), parameter_count);
+          function_state.expected_property_count());
     }
   }
 

src/runtime/runtime-object.cc

@@ -928,23 +928,5 @@ RUNTIME_FUNCTION(Runtime_CreateDataProperty) {
   return *value;
 }
 
-RUNTIME_FUNCTION(Runtime_LoadModuleExport) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 1);
-  CONVERT_ARG_HANDLE_CHECKED(String, name, 0);
-  Handle<JSModule> module(isolate->context()->module());
-  return *JSModule::LoadExport(module, name);
-}
-
-RUNTIME_FUNCTION(Runtime_StoreModuleExport) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 2);
-  CONVERT_ARG_HANDLE_CHECKED(String, name, 0);
-  CONVERT_ARG_HANDLE_CHECKED(Object, value, 1);
-  Handle<JSModule> module(isolate->context()->module());
-  JSModule::StoreExport(module, name, value);
-  return isolate->heap()->undefined_value();
-}
-
 }  // namespace internal
 }  // namespace v8

src/runtime/runtime-scopes.cc

@@ -699,19 +699,6 @@ RUNTIME_FUNCTION(Runtime_PushWithContext) {
   return *context;
 }
 
-RUNTIME_FUNCTION(Runtime_PushModuleContext) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(3, args.length());
-  CONVERT_ARG_HANDLE_CHECKED(JSModule, module, 0);
-  CONVERT_ARG_HANDLE_CHECKED(JSFunction, function, 1);
-  CONVERT_ARG_HANDLE_CHECKED(ScopeInfo, scope_info, 2);
-  DCHECK(function->context() == isolate->context());
-
-  Handle<Context> context =
-      isolate->factory()->NewModuleContext(module, function, scope_info);
-  isolate->set_context(*context);
-  return *context;
-}
 
 RUNTIME_FUNCTION(Runtime_PushCatchContext) {
   HandleScope scope(isolate);

src/runtime/runtime.h

@@ -416,9 +416,7 @@ namespace internal {
   F(HasInPrototypeChain, 2, 1)                       \
   F(CreateIterResultObject, 2, 1)                    \
   F(IsAccessCheckNeeded, 1, 1)                       \
-  F(CreateDataProperty, 3, 1)                        \
-  F(LoadModuleExport, 1, 1)                          \
-  F(StoreModuleExport, 2, 1)
+  F(CreateDataProperty, 3, 1)
 
 #define FOR_EACH_INTRINSIC_OPERATORS(F) \
   F(Multiply, 2, 1)                     \
@@ -477,7 +475,6 @@ namespace internal {
   F(NewClosure_Tenured, 1, 1)           \
   F(NewScriptContext, 2, 1)             \
   F(NewFunctionContext, 1, 1)           \
-  F(PushModuleContext, 3, 1)            \
   F(PushWithContext, 3, 1)              \
   F(PushCatchContext, 4, 1)             \
   F(PushBlockContext, 2, 1)             \

test/cctest/interpreter/bytecode_expectations/CallRuntime.golden

@@ -79,7 +79,7 @@ bytecodes: [
   /*   15 S> */ B(LdrUndefined), R(0),
                 B(CreateArrayLiteral), U8(0), U8(0), U8(1),
                 B(Star), R(1),
-                B(CallJSRuntime), U8(135), R(0), U8(2),
+                B(CallJSRuntime), U8(134), R(0), U8(2),
   /*   44 S> */ B(Return),
 ]
 constant pool: [

test/mjsunit/mjsunit.status

@@ -805,12 +805,6 @@
   'es6/tail-call-megatest*': [SKIP],
 }],  # variant == ignition_turbofan and msan
 
-['variant != ignition', {
-  # Ongoing implementation of modules.
-  # https://bugs.chromium.org/p/v8/issues/detail?id=1569
-  'modules-*': [SKIP],
-}],  # variants != ignition
-
 ##############################################################################
 ['gcov_coverage', {
   # Tests taking too long.

test/mjsunit/modules-exports1.js

-// Copyright 2016 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.
-
-// MODULE
-
-export var myvar = "VAR";
-assertEquals("VAR", myvar);
-assertEquals("VAR", eval("myvar"));
-(() => assertEquals("VAR", myvar))();
-
-export let mylet = "LET";
-assertEquals("LET", mylet);
-assertEquals("LET", eval("mylet"));
-(() => assertEquals("LET", mylet))();
-
-export const myconst = "CONST";
-assertEquals("CONST", myconst);
-assertEquals("CONST", eval("myconst"));
-(() => assertEquals("CONST", myconst))();
-
-
-myvar = 1;
-assertEquals(1, myvar);
-assertEquals(1, eval("myvar"));
-(() => assertEquals(1, myvar))();
-(() => myvar = 2)();
-assertEquals(2, myvar);
-(() => assertEquals(2, myvar))();
-{
-  let f = () => assertEquals(2, myvar);
-  f();
-}
-
-mylet = 1;
-assertEquals(1, mylet);
-assertEquals(1, eval("mylet"));
-(() => assertEquals(1, mylet))();
-(() => mylet = 2)();
-assertEquals(2, mylet);
-assertEquals(2, eval("mylet"));
-(() => assertEquals(2, mylet))();
-{
-  let f = () => assertEquals(2, mylet);
-  f();
-}
-
-assertThrows(() => myconst = 1, TypeError);
-assertEquals("CONST", myconst);
-assertEquals("CONST", eval("myconst"));
-(() => assertEquals("CONST", myconst))();
-{
-  let f = () => assertEquals("CONST", myconst);
-  f();
-}

test/mjsunit/modules-exports2.js

-// Copyright 2016 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.
-
-// MODULE
-
-export function foo() { return 42 }
-assertEquals(42, foo());
-foo = 1;
-assertEquals(1, foo);
-
-let gaga = 43;
-export {gaga as gugu};
-assertEquals(43, gaga);
-
-export default (function bar() { return 43 })
-assertThrows(() => bar(), ReferenceError);
-assertThrows("default", SyntaxError);
-assertThrows("*default*", SyntaxError);
-
-
-var bla = 44;
-var blu = 45;
-export {bla};
-export {bla as blu};
-export {bla as bli};
-assertEquals(44, bla);
-assertEquals(45, blu);
-bla = 46;
-assertEquals(46, bla);
-assertEquals(45, blu);

test/mjsunit/modules-exports3.js

-// Copyright 2016 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.
-
-// MODULE
-
-export { myvar, mylet, myconst };
-
-var myvar = "VAR";
-assertEquals("VAR", myvar);
-let mylet = "LET";
-assertEquals("LET", mylet);
-const myconst = "CONST";
-assertEquals("CONST", myconst);
-
-function* gaga() { yield 1 }
-assertEquals(1, gaga().next().value);
-export {gaga};
-export default gaga;
-export {gaga as gigi};
-assertEquals(1, gaga().next().value);
-
-
-export let gugu = 42;
-
-{
-  assertEquals(42, gugu);
-}
-
-try {
-  assertEquals(42, gugu);
-} catch(_) {
-  assertUnreachable();
-}
-
-try {
-  throw {};
-} catch(_) {
-  assertEquals(42, gugu);
-}
-
-try {
-  throw {};
-} catch({x=gugu}) {
-  assertEquals(42, x);
-}
-
-assertEquals(5, eval("var x = 5; x"));

test/mjsunit/modules-this.js

-// Copyright 2016 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.
-
-// MODULE
-
-assertEquals(undefined, this);

test/test262/test262.status

@@ -26,7 +26,6 @@
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 [
-
 [ALWAYS, {
   ###################### NEEDS INVESTIGATION #######################
 
@@ -313,6 +312,13 @@
   'built-ins/Function/prototype/toString/setter-object': [FAIL],
   'built-ins/Function/prototype/toString/unicode': [FAIL],
 
+  # https://bugs.chromium.org/p/v8/issues/detail?id=1569
+  'language/eval-code/direct/export': [SKIP],
+  'language/eval-code/direct/import': [SKIP],
+  'language/eval-code/indirect/export': [SKIP],
+  'language/eval-code/indirect/import': [SKIP],
+  'language/module-code/*': [SKIP],
+
   # https://bugs.chromium.org/p/v8/issues/detail?id=5012
   # http://bugs.icu-project.org/trac/ticket/12671
   'intl402/Intl/getCanonicalLocales/weird-cases': [FAIL],
@@ -625,21 +631,4 @@
   'built-ins/ArrayBuffer/length-is-too-large-throws': [SKIP],
 }],  # asan == True or msan == True or tsan == True
 
-# Module-related tests
-# https://bugs.chromium.org/p/v8/issues/detail?id=1569
-['variant != ignition', {
-  'language/eval-code/direct/export': [SKIP],
-  'language/eval-code/direct/import': [SKIP],
-  'language/eval-code/indirect/export': [SKIP],
-  'language/eval-code/indirect/import': [SKIP],
-  'language/module-code/*': [SKIP],
-}],  # 'variant != ignition'
-['variant == ignition', {
-  'language/module-code/comment-*': [SKIP],
-  'language/module-code/eval-*': [SKIP],
-  'language/module-code/instn-*': [SKIP],
-  'language/module-code/namespace/*': [SKIP],
-  'language/module-code/parse-err-*': [SKIP],
-}],  # 'variant == ignition'
-
 ]