WIP [esnext] implement async iteration proposal

src/contexts.h

 // Copyright 2012 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.
 
 #ifndef V8_CONTEXTS_H_
 #define V8_CONTEXTS_H_
 
 #include "src/heap/heap.h"
 #include "src/objects.h"
 
@@ skipping 16 matching lines @@
 
 // Heap-allocated activation contexts.
 //
 // Contexts are implemented as FixedArray objects; the Context
 // class is a convenience interface casted on a FixedArray object.
 //
 // Note: Context must have no virtual functions and Context objects
 // must always be allocated via Heap::AllocateContext() or
 // Factory::NewContext.
 
-#define NATIVE_CONTEXT_INTRINSIC_FUNCTIONS(V)                           \
-  V(IS_ARRAYLIKE, JSFunction, is_arraylike)                             \
-  V(GENERATOR_NEXT_INTERNAL, JSFunction, generator_next_internal)       \
-  V(GET_TEMPLATE_CALL_SITE_INDEX, JSFunction, get_template_call_site)   \
-  V(MAKE_ERROR_INDEX, JSFunction, make_error)                           \
-  V(MAKE_RANGE_ERROR_INDEX, JSFunction, make_range_error)               \
-  V(MAKE_SYNTAX_ERROR_INDEX, JSFunction, make_syntax_error)             \
-  V(MAKE_TYPE_ERROR_INDEX, JSFunction, make_type_error)                 \
-  V(MAKE_URI_ERROR_INDEX, JSFunction, make_uri_error)                   \
-  V(OBJECT_CREATE, JSFunction, object_create)                           \
-  V(OBJECT_DEFINE_PROPERTIES, JSFunction, object_define_properties)     \
-  V(OBJECT_DEFINE_PROPERTY, JSFunction, object_define_property)         \
-  V(OBJECT_FREEZE, JSFunction, object_freeze)                           \
-  V(OBJECT_GET_PROTOTYPE_OF, JSFunction, object_get_prototype_of)       \
-  V(OBJECT_IS_EXTENSIBLE, JSFunction, object_is_extensible)             \
-  V(OBJECT_IS_FROZEN, JSFunction, object_is_frozen)                     \
-  V(OBJECT_IS_SEALED, JSFunction, object_is_sealed)                     \
-  V(OBJECT_KEYS, JSFunction, object_keys)                               \
-  V(REGEXP_INTERNAL_MATCH, JSFunction, regexp_internal_match)           \
-  V(REFLECT_APPLY_INDEX, JSFunction, reflect_apply)                     \
-  V(REFLECT_CONSTRUCT_INDEX, JSFunction, reflect_construct)             \
-  V(REFLECT_DEFINE_PROPERTY_INDEX, JSFunction, reflect_define_property) \
-  V(REFLECT_DELETE_PROPERTY_INDEX, JSFunction, reflect_delete_property) \
-  V(SPREAD_ARGUMENTS_INDEX, JSFunction, spread_arguments)               \
-  V(SPREAD_ITERABLE_INDEX, JSFunction, spread_iterable)                 \
-  V(MATH_FLOOR_INDEX, JSFunction, math_floor)                           \
-  V(MATH_POW_INDEX, JSFunction, math_pow)                               \
-  V(NEW_PROMISE_CAPABILITY_INDEX, JSFunction, new_promise_capability)   \
-  V(PROMISE_INTERNAL_CONSTRUCTOR_INDEX, JSFunction,                     \
-    promise_internal_constructor)                                       \
-  V(IS_PROMISE_INDEX, JSFunction, is_promise)                           \
-  V(PERFORM_PROMISE_THEN_INDEX, JSFunction, perform_promise_then)       \
-  V(PROMISE_CREATE_AND_SET_INDEX, JSFunction, promise_create_and_set)   \
-  V(PROMISE_RESOLVE_INDEX, JSFunction, promise_resolve)                 \
-  V(PROMISE_THEN_INDEX, JSFunction, promise_then)                       \
-  V(PROMISE_HANDLE_INDEX, JSFunction, promise_handle)                   \
-  V(PROMISE_HANDLE_REJECT_INDEX, JSFunction, promise_handle_reject)
+#define NATIVE_CONTEXT_INTRINSIC_FUNCTIONS(V)                               \
+  V(IS_ARRAYLIKE, JSFunction, is_arraylike)                                 \
+  V(GENERATOR_NEXT_INTERNAL, JSFunction, generator_next_internal)           \
+  V(GET_TEMPLATE_CALL_SITE_INDEX, JSFunction, get_template_call_site)       \
+  V(MAKE_ERROR_INDEX, JSFunction, make_error)                               \
+  V(MAKE_RANGE_ERROR_INDEX, JSFunction, make_range_error)                   \
+  V(MAKE_SYNTAX_ERROR_INDEX, JSFunction, make_syntax_error)                 \
+  V(MAKE_TYPE_ERROR_INDEX, JSFunction, make_type_error)                     \
+  V(MAKE_URI_ERROR_INDEX, JSFunction, make_uri_error)                       \
+  V(OBJECT_CREATE, JSFunction, object_create)                               \
+  V(OBJECT_DEFINE_PROPERTIES, JSFunction, object_define_properties)         \
+  V(OBJECT_DEFINE_PROPERTY, JSFunction, object_define_property)             \
+  V(OBJECT_FREEZE, JSFunction, object_freeze)                               \
+  V(OBJECT_GET_PROTOTYPE_OF, JSFunction, object_get_prototype_of)           \
+  V(OBJECT_IS_EXTENSIBLE, JSFunction, object_is_extensible)                 \
+  V(OBJECT_IS_FROZEN, JSFunction, object_is_frozen)                         \
+  V(OBJECT_IS_SEALED, JSFunction, object_is_sealed)                         \
+  V(OBJECT_KEYS, JSFunction, object_keys)                                   \
+  V(REGEXP_INTERNAL_MATCH, JSFunction, regexp_internal_match)               \
+  V(REFLECT_APPLY_INDEX, JSFunction, reflect_apply)                         \
+  V(REFLECT_CONSTRUCT_INDEX, JSFunction, reflect_construct)                 \
+  V(REFLECT_DEFINE_PROPERTY_INDEX, JSFunction, reflect_define_property)     \
+  V(REFLECT_DELETE_PROPERTY_INDEX, JSFunction, reflect_delete_property)     \
+  V(SPREAD_ARGUMENTS_INDEX, JSFunction, spread_arguments)                   \
+  V(SPREAD_ITERABLE_INDEX, JSFunction, spread_iterable)                     \
+  V(MATH_FLOOR_INDEX, JSFunction, math_floor)                               \
+  V(MATH_POW_INDEX, JSFunction, math_pow)                                   \
+  V(NEW_PROMISE_CAPABILITY_INDEX, JSFunction, new_promise_capability)       \
+  V(PROMISE_INTERNAL_CONSTRUCTOR_INDEX, JSFunction,                         \
+    promise_internal_constructor)                                           \
+  V(IS_PROMISE_INDEX, JSFunction, is_promise)                               \
+  V(PERFORM_PROMISE_THEN_INDEX, JSFunction, perform_promise_then)           \
+  V(PROMISE_CREATE_AND_SET_INDEX, JSFunction, promise_create_and_set)       \
+  V(PROMISE_RESOLVE_INDEX, JSFunction, promise_resolve)                     \
+  V(PROMISE_THEN_INDEX, JSFunction, promise_then)                           \
+  V(PROMISE_HANDLE_INDEX, JSFunction, promise_handle)                       \
+  V(PROMISE_HANDLE_REJECT_INDEX, JSFunction, promise_handle_reject)         \
+  V(ASYNC_GENERATOR_AWAIT_CAUGHT, JSFunction, async_generator_await_caught) \
+  V(ASYNC_GENERATOR_AWAIT_UNCAUGHT, JSFunction,                             \
+    async_generator_await_uncaught)                                         \
+  V(ASYNC_GENERATOR_YIELD, JSFunction, async_generator_yield)
 
 #define NATIVE_CONTEXT_IMPORTED_FIELDS(V)                                     \
   V(ARRAY_CONCAT_INDEX, JSFunction, array_concat)                             \
   V(ARRAY_POP_INDEX, JSFunction, array_pop)                                   \
   V(ARRAY_PUSH_INDEX, JSFunction, array_push)                                 \
   V(ARRAY_SHIFT_INDEX, JSFunction, array_shift)                               \
   V(ARRAY_SPLICE_INDEX, JSFunction, array_splice)                             \
   V(ARRAY_SLICE_INDEX, JSFunction, array_slice)                               \
   V(ARRAY_UNSHIFT_INDEX, JSFunction, array_unshift)                           \
   V(ARRAY_VALUES_ITERATOR_INDEX, JSFunction, array_values_iterator)           \
@@ skipping 106 matching lines @@
     fast_holey_double_array_value_iterator_map)                                \
   V(GENERIC_ARRAY_VALUE_ITERATOR_MAP_INDEX, Map, array_value_iterator_map)
 
 #define NATIVE_CONTEXT_FIELDS(V)                                               \
   V(GLOBAL_PROXY_INDEX, JSObject, global_proxy_object)                         \
   V(EMBEDDER_DATA_INDEX, FixedArray, embedder_data)                            \
   /* Below is alpha-sorted */                                                  \
   V(ACCESSOR_PROPERTY_DESCRIPTOR_MAP_INDEX, Map,                               \
     accessor_property_descriptor_map)                                          \
   V(ALLOW_CODE_GEN_FROM_STRINGS_INDEX, Object, allow_code_gen_from_strings)    \
+  V(ASYNC_GENERATOR_AWAIT_REJECT_SHARED_FUN, SharedFunctionInfo,               \
+    async_generator_await_reject_shared_fun)                                   \
+  V(ASYNC_GENERATOR_AWAIT_RESOLVE_SHARED_FUN, SharedFunctionInfo,              \
+    async_generator_await_resolve_shared_fun)                                  \
+  V(ASYNC_ITERATOR_VALUE_UNWRAP_SHARED_FUN, SharedFunctionInfo,                \
+    async_iterator_value_unwrap_shared_fun)                                    \
   V(ARRAY_BUFFER_FUN_INDEX, JSFunction, array_buffer_fun)                      \
   V(ARRAY_BUFFER_MAP_INDEX, Map, array_buffer_map)                             \
   V(ARRAY_FUNCTION_INDEX, JSFunction, array_function)                          \
   V(ASYNC_FUNCTION_FUNCTION_INDEX, JSFunction, async_function_constructor)     \
+  V(ASYNC_GENERATOR_FUNCTION_FUNCTION_INDEX, JSFunction,                       \
+    async_generator_function_function)                                         \
   V(BOOL16X8_FUNCTION_INDEX, JSFunction, bool16x8_function)                    \
   V(BOOL32X4_FUNCTION_INDEX, JSFunction, bool32x4_function)                    \
   V(BOOL8X16_FUNCTION_INDEX, JSFunction, bool8x16_function)                    \
   V(BOOLEAN_FUNCTION_INDEX, JSFunction, boolean_function)                      \
   V(BOUND_FUNCTION_WITH_CONSTRUCTOR_MAP_INDEX, Map,                            \
     bound_function_with_constructor_map)                                       \
   V(BOUND_FUNCTION_WITHOUT_CONSTRUCTOR_MAP_INDEX, Map,                         \
     bound_function_without_constructor_map)                                    \
   V(CALL_AS_CONSTRUCTOR_DELEGATE_INDEX, JSFunction,                            \
     call_as_constructor_delegate)                                              \
@@ skipping 12 matching lines @@
   V(FAST_ALIASED_ARGUMENTS_MAP_INDEX, Map, fast_aliased_arguments_map)         \
   V(FAST_TEMPLATE_INSTANTIATIONS_CACHE_INDEX, FixedArray,                      \
     fast_template_instantiations_cache)                                        \
   V(FLOAT32_ARRAY_FUN_INDEX, JSFunction, float32_array_fun)                    \
   V(FLOAT32X4_FUNCTION_INDEX, JSFunction, float32x4_function)                  \
   V(FLOAT64_ARRAY_FUN_INDEX, JSFunction, float64_array_fun)                    \
   V(FUNCTION_FUNCTION_INDEX, JSFunction, function_function)                    \
   V(GENERATOR_FUNCTION_FUNCTION_INDEX, JSFunction,                             \
     generator_function_function)                                               \
   V(GENERATOR_OBJECT_PROTOTYPE_MAP_INDEX, Map, generator_object_prototype_map) \
+  V(ASYNC_GENERATOR_OBJECT_PROTOTYPE_MAP_INDEX, Map,                           \
+    async_generator_object_prototype_map)                                      \
   V(INITIAL_ARRAY_ITERATOR_PROTOTYPE_INDEX, JSObject,                          \
     initial_array_iterator_prototype)                                          \
   V(INITIAL_ARRAY_ITERATOR_PROTOTYPE_MAP_INDEX, Map,                           \
     initial_array_iterator_prototype_map)                                      \
   V(INITIAL_ARRAY_PROTOTYPE_INDEX, JSObject, initial_array_prototype)          \
   V(INITIAL_GENERATOR_PROTOTYPE_INDEX, JSObject, initial_generator_prototype)  \
   V(INITIAL_ITERATOR_PROTOTYPE_INDEX, JSObject, initial_iterator_prototype)    \
+  V(INITIAL_ASYNC_ITERATOR_PROTOTYPE_INDEX, JSObject,                          \

[caitp, 2017/01/10 04:13:42]

I don't think these are necessarily needed.

+    initial_async_iterator_prototype)                                          \
+  V(INITIAL_ASYNC_FROM_SYNC_ITERATOR_MAP_INDEX, Map,                           \
+    initial_async_from_sync_iterator_map)                                      \
   V(INITIAL_OBJECT_PROTOTYPE_INDEX, JSObject, initial_object_prototype)        \
   V(INT16_ARRAY_FUN_INDEX, JSFunction, int16_array_fun)                        \
   V(INT16X8_FUNCTION_INDEX, JSFunction, int16x8_function)                      \
   V(INT32_ARRAY_FUN_INDEX, JSFunction, int32_array_fun)                        \
   V(INT32X4_FUNCTION_INDEX, JSFunction, int32x4_function)                      \
   V(INT8_ARRAY_FUN_INDEX, JSFunction, int8_array_fun)                          \
   V(INT8X16_FUNCTION_INDEX, JSFunction, int8x16_function)                      \
   V(INTERNAL_ARRAY_FUNCTION_INDEX, JSFunction, internal_array_function)        \
   V(ITERATOR_RESULT_MAP_INDEX, Map, iterator_result_map)                       \
   V(JS_ARRAY_FAST_SMI_ELEMENTS_MAP_INDEX, Map,                                 \
@@ skipping 60 matching lines @@
   V(SLOW_OBJECT_WITH_NULL_PROTOTYPE_MAP, Map,                                  \
     slow_object_with_null_prototype_map)                                       \
   V(SLOW_TEMPLATE_INSTANTIATIONS_CACHE_INDEX, UnseededNumberDictionary,        \
     slow_template_instantiations_cache)                                        \
   V(STRICT_ARGUMENTS_MAP_INDEX, Map, strict_arguments_map)                     \
   V(ASYNC_FUNCTION_MAP_INDEX, Map, async_function_map)                         \
   V(STRICT_FUNCTION_MAP_INDEX, Map, strict_function_map)                       \
   V(STRICT_FUNCTION_WITHOUT_PROTOTYPE_MAP_INDEX, Map,                          \
     strict_function_without_prototype_map)                                     \
   V(GENERATOR_FUNCTION_MAP_INDEX, Map, generator_function_map)                 \
+  V(ASYNC_GENERATOR_FUNCTION_MAP_INDEX, Map, async_generator_function_map)     \
   V(CLASS_FUNCTION_MAP_INDEX, Map, class_function_map)                         \
   V(STRING_FUNCTION_INDEX, JSFunction, string_function)                        \
   V(STRING_FUNCTION_PROTOTYPE_MAP_INDEX, Map, string_function_prototype_map)   \
   V(STRING_ITERATOR_MAP_INDEX, Map, string_iterator_map)                       \
   V(SYMBOL_FUNCTION_INDEX, JSFunction, symbol_function)                        \
   V(WASM_FUNCTION_MAP_INDEX, Map, wasm_function_map)                           \
   V(WASM_INSTANCE_CONSTRUCTOR_INDEX, JSFunction, wasm_instance_constructor)    \
   V(WASM_INSTANCE_SYM_INDEX, Symbol, wasm_instance_sym)                        \
   V(WASM_MEMORY_CONSTRUCTOR_INDEX, JSFunction, wasm_memory_constructor)        \
   V(WASM_MEMORY_SYM_INDEX, Symbol, wasm_memory_sym)                            \
@@ skipping 295 matching lines @@
                         VariableMode* variable_mode);
 
   // Code generation support.
   static int SlotOffset(int index) {
     return kHeaderSize + index * kPointerSize - kHeapObjectTag;
   }
 
   static int FunctionMapIndex(LanguageMode language_mode, FunctionKind kind) {
     // Note: Must be kept in sync with the FastNewClosure builtin.
     if (IsGeneratorFunction(kind)) {
-      return GENERATOR_FUNCTION_MAP_INDEX;
+      return IsAsyncFunction(kind) ? ASYNC_GENERATOR_FUNCTION_MAP_INDEX
+                                   : GENERATOR_FUNCTION_MAP_INDEX;
     }
 
     if (IsAsyncFunction(kind)) {
       return ASYNC_FUNCTION_MAP_INDEX;
     }
 
     if (IsClassConstructor(kind)) {
       // Like the strict function map, but with no 'name' accessor. 'name'
       // needs to be the last property and it is added during instantiation,
       // in case a static property with the same name exists"
@@ skipping 37 matching lines @@
   STATIC_ASSERT(kHeaderSize == Internals::kContextHeaderSize);
   STATIC_ASSERT(EMBEDDER_DATA_INDEX == Internals::kContextEmbedderDataIndex);
 };
 
 typedef Context::Field ContextField;
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_CONTEXTS_H_