| // 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" |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| enum ContextLookupFlags { |
| FOLLOW_CONTEXT_CHAIN = 1 << 0, |
| FOLLOW_PROTOTYPE_CHAIN = 1 << 1, |
| STOP_AT_DECLARATION_SCOPE = 1 << 2, |
| SKIP_WITH_CONTEXT = 1 << 3, |
| |
| DONT_FOLLOW_CHAINS = 0, |
| FOLLOW_CHAINS = FOLLOW_CONTEXT_CHAIN | FOLLOW_PROTOTYPE_CHAIN, |
| LEXICAL_TEST = |
| FOLLOW_CONTEXT_CHAIN | STOP_AT_DECLARATION_SCOPE | SKIP_WITH_CONTEXT, |
| }; |
| |
| |
| // ES5 10.2 defines lexical environments with mutable and immutable bindings. |
| // Immutable bindings have two states, initialized and uninitialized, and |
| // their state is changed by the InitializeImmutableBinding method. The |
| // BindingFlags enum represents information if a binding has definitely been |
| // initialized. A mutable binding does not need to be checked and thus has |
| // the BindingFlag MUTABLE_IS_INITIALIZED. |
| // |
| // There are two possibilities for immutable bindings |
| // * 'const' declared variables. They are initialized when evaluating the |
| // corresponding declaration statement. They need to be checked for being |
| // initialized and thus get the flag IMMUTABLE_CHECK_INITIALIZED. |
| // * The function name of a named function literal. The binding is immediately |
| // initialized when entering the function and thus does not need to be |
| // checked. it gets the BindingFlag IMMUTABLE_IS_INITIALIZED. |
| // Accessing an uninitialized binding produces the undefined value. |
| // |
| // The harmony proposal for block scoped bindings also introduces the |
| // uninitialized state for mutable bindings. |
| // * A 'let' declared variable. They are initialized when evaluating the |
| // corresponding declaration statement. They need to be checked for being |
| // initialized and thus get the flag MUTABLE_CHECK_INITIALIZED. |
| // * A 'var' declared variable. It is initialized immediately upon creation |
| // and thus doesn't need to be checked. It gets the flag |
| // MUTABLE_IS_INITIALIZED. |
| // * Catch bound variables, function parameters and variables introduced by |
| // function declarations are initialized immediately and do not need to be |
| // checked. Thus they get the flag MUTABLE_IS_INITIALIZED. |
| // Immutable bindings in harmony mode get the _HARMONY flag variants. Accessing |
| // an uninitialized binding produces a reference error. |
| // |
| // In V8 uninitialized bindings are set to the hole value upon creation and set |
| // to a different value upon initialization. |
| enum BindingFlags { |
| MUTABLE_IS_INITIALIZED, |
| MUTABLE_CHECK_INITIALIZED, |
| IMMUTABLE_IS_INITIALIZED, |
| IMMUTABLE_CHECK_INITIALIZED, |
| IMMUTABLE_IS_INITIALIZED_HARMONY, |
| IMMUTABLE_CHECK_INITIALIZED_HARMONY, |
| MISSING_BINDING |
| }; |
| |
| |
| // 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(CONCAT_ITERABLE_TO_ARRAY_INDEX, JSFunction, concat_iterable_to_array) \ |
| V(GET_TEMPLATE_CALL_SITE_INDEX, JSFunction, get_template_call_site) \ |
| V(MAKE_RANGE_ERROR_INDEX, JSFunction, make_range_error) \ |
| V(MAKE_TYPE_ERROR_INDEX, JSFunction, make_type_error) \ |
| V(OBJECT_FREEZE, JSFunction, object_freeze) \ |
| 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(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(ORDINARY_HAS_INSTANCE_INDEX, JSFunction, ordinary_has_instance) |
| |
| #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) \ |
| V(DERIVED_GET_TRAP_INDEX, JSFunction, derived_get_trap) \ |
| V(ERROR_FUNCTION_INDEX, JSFunction, error_function) \ |
| V(EVAL_ERROR_FUNCTION_INDEX, JSFunction, eval_error_function) \ |
| V(GET_STACK_TRACE_LINE_INDEX, JSFunction, get_stack_trace_line_fun) \ |
| V(GLOBAL_EVAL_FUN_INDEX, JSFunction, global_eval_fun) \ |
| V(JSON_SERIALIZE_ADAPTER_INDEX, JSFunction, json_serialize_adapter) \ |
| V(MAKE_ERROR_FUNCTION_INDEX, JSFunction, make_error_function) \ |
| V(MAP_DELETE_METHOD_INDEX, JSFunction, map_delete) \ |
| V(MAP_GET_METHOD_INDEX, JSFunction, map_get) \ |
| V(MAP_HAS_METHOD_INDEX, JSFunction, map_has) \ |
| V(MAP_SET_METHOD_INDEX, JSFunction, map_set) \ |
| V(MESSAGE_GET_COLUMN_NUMBER_INDEX, JSFunction, message_get_column_number) \ |
| V(MESSAGE_GET_LINE_NUMBER_INDEX, JSFunction, message_get_line_number) \ |
| V(MESSAGE_GET_SOURCE_LINE_INDEX, JSFunction, message_get_source_line) \ |
| V(NATIVE_OBJECT_GET_NOTIFIER_INDEX, JSFunction, native_object_get_notifier) \ |
| V(NATIVE_OBJECT_NOTIFIER_PERFORM_CHANGE, JSFunction, \ |
| native_object_notifier_perform_change) \ |
| V(NATIVE_OBJECT_OBSERVE_INDEX, JSFunction, native_object_observe) \ |
| V(NO_SIDE_EFFECTS_TO_STRING_FUN_INDEX, JSFunction, \ |
| no_side_effects_to_string_fun) \ |
| V(OBJECT_VALUE_OF, JSFunction, object_value_of) \ |
| V(OBJECT_TO_STRING, JSFunction, object_to_string) \ |
| V(OBSERVERS_BEGIN_SPLICE_INDEX, JSFunction, observers_begin_perform_splice) \ |
| V(OBSERVERS_END_SPLICE_INDEX, JSFunction, observers_end_perform_splice) \ |
| V(OBSERVERS_ENQUEUE_SPLICE_INDEX, JSFunction, observers_enqueue_splice) \ |
| V(OBSERVERS_NOTIFY_CHANGE_INDEX, JSFunction, observers_notify_change) \ |
| V(PROMISE_CATCH_INDEX, JSFunction, promise_catch) \ |
| V(PROMISE_CHAIN_INDEX, JSFunction, promise_chain) \ |
| V(PROMISE_CREATE_INDEX, JSFunction, promise_create) \ |
| V(PROMISE_FUNCTION_INDEX, JSFunction, promise_function) \ |
| V(PROMISE_HAS_USER_DEFINED_REJECT_HANDLER_INDEX, JSFunction, \ |
| promise_has_user_defined_reject_handler) \ |
| V(PROMISE_REJECT_INDEX, JSFunction, promise_reject) \ |
| V(PROMISE_RESOLVE_INDEX, JSFunction, promise_resolve) \ |
| V(PROMISE_THEN_INDEX, JSFunction, promise_then) \ |
| V(RANGE_ERROR_FUNCTION_INDEX, JSFunction, range_error_function) \ |
| V(REFERENCE_ERROR_FUNCTION_INDEX, JSFunction, reference_error_function) \ |
| V(SET_ADD_METHOD_INDEX, JSFunction, set_add) \ |
| V(SET_DELETE_METHOD_INDEX, JSFunction, set_delete) \ |
| V(SET_HAS_METHOD_INDEX, JSFunction, set_has) \ |
| V(STACK_OVERFLOW_BOILERPLATE_INDEX, JSObject, stack_overflow_boilerplate) \ |
| V(SYNTAX_ERROR_FUNCTION_INDEX, JSFunction, syntax_error_function) \ |
| V(TYPE_ERROR_FUNCTION_INDEX, JSFunction, type_error_function) \ |
| V(URI_ERROR_FUNCTION_INDEX, JSFunction, uri_error_function) |
| |
| #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(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(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) \ |
| V(CALL_AS_FUNCTION_DELEGATE_INDEX, JSFunction, call_as_function_delegate) \ |
| V(CONTEXT_EXTENSION_FUNCTION_INDEX, JSFunction, context_extension_function) \ |
| V(DATA_PROPERTY_DESCRIPTOR_MAP_INDEX, Map, data_property_descriptor_map) \ |
| V(DATA_VIEW_FUN_INDEX, JSFunction, data_view_fun) \ |
| V(DATE_FUNCTION_INDEX, JSFunction, date_function) \ |
| V(ERROR_MESSAGE_FOR_CODE_GEN_FROM_STRINGS_INDEX, Object, \ |
| error_message_for_code_gen_from_strings) \ |
| V(ERRORS_THROWN_INDEX, Smi, errors_thrown) \ |
| V(EXTRAS_EXPORTS_OBJECT_INDEX, JSObject, extras_binding_object) \ |
| V(EXTRAS_UTILS_OBJECT_INDEX, JSObject, extras_utils_object) \ |
| V(FAST_ALIASED_ARGUMENTS_MAP_INDEX, Map, fast_aliased_arguments_map) \ |
| 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(TEMPLATE_INSTANTIATIONS_CACHE_INDEX, UnseededNumberDictionary, \ |
| template_instantiations_cache) \ |
| 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(INITIAL_ARRAY_PROTOTYPE_INDEX, JSObject, initial_array_prototype) \ |
| 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, \ |
| js_array_fast_smi_elements_map_index) \ |
| V(JS_ARRAY_FAST_HOLEY_SMI_ELEMENTS_MAP_INDEX, Map, \ |
| js_array_fast_holey_smi_elements_map_index) \ |
| V(JS_ARRAY_FAST_ELEMENTS_MAP_INDEX, Map, js_array_fast_elements_map_index) \ |
| V(JS_ARRAY_FAST_HOLEY_ELEMENTS_MAP_INDEX, Map, \ |
| js_array_fast_holey_elements_map_index) \ |
| V(JS_ARRAY_FAST_DOUBLE_ELEMENTS_MAP_INDEX, Map, \ |
| js_array_fast_double_elements_map_index) \ |
| V(JS_ARRAY_FAST_HOLEY_DOUBLE_ELEMENTS_MAP_INDEX, Map, \ |
| js_array_fast_holey_double_elements_map_index) \ |
| V(JS_MAP_FUN_INDEX, JSFunction, js_map_fun) \ |
| V(JS_MAP_MAP_INDEX, Map, js_map_map) \ |
| V(JS_SET_FUN_INDEX, JSFunction, js_set_fun) \ |
| V(JS_SET_MAP_INDEX, Map, js_set_map) \ |
| V(JS_WEAK_MAP_FUN_INDEX, JSFunction, js_weak_map_fun) \ |
| V(JS_WEAK_SET_FUN_INDEX, JSFunction, js_weak_set_fun) \ |
| V(MAP_CACHE_INDEX, Object, map_cache) \ |
| V(MAP_ITERATOR_MAP_INDEX, Map, map_iterator_map) \ |
| V(STRING_ITERATOR_MAP_INDEX, Map, string_iterator_map) \ |
| V(MESSAGE_LISTENERS_INDEX, JSObject, message_listeners) \ |
| V(NATIVES_UTILS_OBJECT_INDEX, Object, natives_utils_object) \ |
| V(NORMALIZED_MAP_CACHE_INDEX, Object, normalized_map_cache) \ |
| V(NUMBER_FUNCTION_INDEX, JSFunction, number_function) \ |
| V(OBJECT_FUNCTION_INDEX, JSFunction, object_function) \ |
| V(OBJECT_FUNCTION_PROTOTYPE_MAP_INDEX, Map, object_function_prototype_map) \ |
| V(OPAQUE_REFERENCE_FUNCTION_INDEX, JSFunction, opaque_reference_function) \ |
| V(PROXY_CALLABLE_MAP_INDEX, Map, proxy_callable_map) \ |
| V(PROXY_CONSTRUCTOR_MAP_INDEX, Map, proxy_constructor_map) \ |
| V(PROXY_FUNCTION_INDEX, JSFunction, proxy_function) \ |
| V(PROXY_FUNCTION_MAP_INDEX, Map, proxy_function_map) \ |
| V(PROXY_MAP_INDEX, Map, proxy_map) \ |
| V(REGEXP_FUNCTION_INDEX, JSFunction, regexp_function) \ |
| V(REGEXP_RESULT_MAP_INDEX, Map, regexp_result_map) \ |
| V(SCRIPT_CONTEXT_TABLE_INDEX, ScriptContextTable, script_context_table) \ |
| V(SCRIPT_FUNCTION_INDEX, JSFunction, script_function) \ |
| V(SECURITY_TOKEN_INDEX, Object, security_token) \ |
| V(SELF_WEAK_CELL_INDEX, WeakCell, self_weak_cell) \ |
| V(SET_ITERATOR_MAP_INDEX, Map, set_iterator_map) \ |
| V(SHARED_ARRAY_BUFFER_FUN_INDEX, JSFunction, shared_array_buffer_fun) \ |
| V(SLOPPY_ARGUMENTS_MAP_INDEX, Map, sloppy_arguments_map) \ |
| V(SLOPPY_FUNCTION_MAP_INDEX, Map, sloppy_function_map) \ |
| V(SLOPPY_FUNCTION_WITHOUT_PROTOTYPE_MAP_INDEX, Map, \ |
| sloppy_function_without_prototype_map) \ |
| V(SLOPPY_FUNCTION_WITH_READONLY_PROTOTYPE_MAP_INDEX, Map, \ |
| sloppy_function_with_readonly_prototype_map) \ |
| V(WASM_FUNCTION_MAP_INDEX, Map, wasm_function_map) \ |
| V(SLOPPY_GENERATOR_FUNCTION_MAP_INDEX, Map, sloppy_generator_function_map) \ |
| V(SLOW_ALIASED_ARGUMENTS_MAP_INDEX, Map, slow_aliased_arguments_map) \ |
| V(STRICT_ARGUMENTS_MAP_INDEX, Map, strict_arguments_map) \ |
| V(STRICT_FUNCTION_MAP_INDEX, Map, strict_function_map) \ |
| V(STRICT_FUNCTION_WITHOUT_PROTOTYPE_MAP_INDEX, Map, \ |
| strict_function_without_prototype_map) \ |
| V(STRICT_GENERATOR_FUNCTION_MAP_INDEX, Map, strict_generator_function_map) \ |
| V(STRING_FUNCTION_INDEX, JSFunction, string_function) \ |
| V(STRING_FUNCTION_PROTOTYPE_MAP_INDEX, Map, string_function_prototype_map) \ |
| V(SYMBOL_FUNCTION_INDEX, JSFunction, symbol_function) \ |
| V(UINT16_ARRAY_FUN_INDEX, JSFunction, uint16_array_fun) \ |
| V(UINT16X8_FUNCTION_INDEX, JSFunction, uint16x8_function) \ |
| V(UINT32_ARRAY_FUN_INDEX, JSFunction, uint32_array_fun) \ |
| V(UINT32X4_FUNCTION_INDEX, JSFunction, uint32x4_function) \ |
| 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) \ |
| NATIVE_CONTEXT_INTRINSIC_FUNCTIONS(V) \ |
| NATIVE_CONTEXT_IMPORTED_FIELDS(V) |
| |
| // A table of all script contexts. Every loaded top-level script with top-level |
| // lexical declarations contributes its ScriptContext into this table. |
| // |
| // The table is a fixed array, its first slot is the current used count and |
| // the subsequent slots 1..used contain ScriptContexts. |
| class ScriptContextTable : public FixedArray { |
| public: |
| // Conversions. |
| static inline ScriptContextTable* cast(Object* context); |
| |
| struct LookupResult { |
| int context_index; |
| int slot_index; |
| VariableMode mode; |
| InitializationFlag init_flag; |
| MaybeAssignedFlag maybe_assigned_flag; |
| }; |
| |
| inline int used() const; |
| inline void set_used(int used); |
| |
| static inline Handle<Context> GetContext(Handle<ScriptContextTable> table, |
| int i); |
| |
| // Lookup a variable `name` in a ScriptContextTable. |
| // If it returns true, the variable is found and `result` contains |
| // valid information about its location. |
| // If it returns false, `result` is untouched. |
| MUST_USE_RESULT |
| static bool Lookup(Handle<ScriptContextTable> table, Handle<String> name, |
| LookupResult* result); |
| |
| MUST_USE_RESULT |
| static Handle<ScriptContextTable> Extend(Handle<ScriptContextTable> table, |
| Handle<Context> script_context); |
| |
| static int GetContextOffset(int context_index) { |
| return kFirstContextOffset + context_index * kPointerSize; |
| } |
| |
| private: |
| static const int kUsedSlot = 0; |
| static const int kFirstContextSlot = kUsedSlot + 1; |
| static const int kFirstContextOffset = |
| FixedArray::kHeaderSize + kFirstContextSlot * kPointerSize; |
| |
| DISALLOW_IMPLICIT_CONSTRUCTORS(ScriptContextTable); |
| }; |
| |
| // JSFunctions are pairs (context, function code), sometimes also called |
| // closures. A Context object is used to represent function contexts and |
| // dynamically pushed 'with' contexts (or 'scopes' in ECMA-262 speak). |
| // |
| // At runtime, the contexts build a stack in parallel to the execution |
| // stack, with the top-most context being the current context. All contexts |
| // have the following slots: |
| // |
| // [ closure ] This is the current function. It is the same for all |
| // contexts inside a function. It provides access to the |
| // incoming context (i.e., the outer context, which may |
| // or may not become the current function's context), and |
| // it provides access to the functions code and thus it's |
| // scope information, which in turn contains the names of |
| // statically allocated context slots. The names are needed |
| // for dynamic lookups in the presence of 'with' or 'eval'. |
| // |
| // [ previous ] A pointer to the previous context. It is NULL for |
| // function contexts, and non-NULL for 'with' contexts. |
| // Used to implement the 'with' statement. |
| // |
| // [ extension ] A pointer to an extension JSObject, or "the hole". Used to |
| // implement 'with' statements and dynamic declarations |
| // (through 'eval'). The object in a 'with' statement is |
| // stored in the extension slot of a 'with' context. |
| // Dynamically declared variables/functions are also added |
| // to lazily allocated extension object. Context::Lookup |
| // searches the extension object for properties. |
| // For script and block contexts, contains the respective |
| // ScopeInfo. For block contexts representing sloppy declaration |
| // block scopes, it may also be a struct being a |
| // SloppyBlockWithEvalContextExtension, pairing the ScopeInfo |
| // with an extension object. |
| // For module contexts, points back to the respective JSModule. |
| // |
| // [ global_object ] A pointer to the global object. Provided for quick |
| // access to the global object from inside the code (since |
| // we always have a context pointer). |
| // |
| // In addition, function contexts may have statically allocated context slots |
| // to store local variables/functions that are accessed from inner functions |
| // (via static context addresses) or through 'eval' (dynamic context lookups). |
| // The native context contains additional slots for fast access to native |
| // properties. |
| // |
| // Finally, with Harmony scoping, the JSFunction representing a top level |
| // script will have the ScriptContext rather than a FunctionContext. |
| // Script contexts from all top-level scripts are gathered in |
| // ScriptContextTable. |
| |
| class Context: public FixedArray { |
| public: |
| // Conversions. |
| static inline Context* cast(Object* context); |
| |
| // The default context slot layout; indices are FixedArray slot indices. |
| enum { |
| // These slots are in all contexts. |
| CLOSURE_INDEX, |
| PREVIOUS_INDEX, |
| // The extension slot is used for either the global object (in native |
| // contexts), eval extension object (function contexts), subject of with |
| // (with contexts), or the variable name (catch contexts), the serialized |
| // scope info (block contexts), or the module instance (module contexts). |
| EXTENSION_INDEX, |
| NATIVE_CONTEXT_INDEX, |
| |
| // These slots are only in native contexts. |
| #define NATIVE_CONTEXT_SLOT(index, type, name) index, |
| NATIVE_CONTEXT_FIELDS(NATIVE_CONTEXT_SLOT) |
| #undef NATIVE_CONTEXT_SLOT |
| |
| // Properties from here are treated as weak references by the full GC. |
| // Scavenge treats them as strong references. |
| OPTIMIZED_FUNCTIONS_LIST, // Weak. |
| OPTIMIZED_CODE_LIST, // Weak. |
| DEOPTIMIZED_CODE_LIST, // Weak. |
| NEXT_CONTEXT_LINK, // Weak. |
| |
| // Total number of slots. |
| NATIVE_CONTEXT_SLOTS, |
| FIRST_WEAK_SLOT = OPTIMIZED_FUNCTIONS_LIST, |
| FIRST_JS_ARRAY_MAP_SLOT = JS_ARRAY_FAST_SMI_ELEMENTS_MAP_INDEX, |
| |
| MIN_CONTEXT_SLOTS = GLOBAL_PROXY_INDEX, |
| // This slot holds the thrown value in catch contexts. |
| THROWN_OBJECT_INDEX = MIN_CONTEXT_SLOTS, |
| }; |
| |
| void IncrementErrorsThrown(); |
| int GetErrorsThrown(); |
| |
| // Direct slot access. |
| inline JSFunction* closure(); |
| inline void set_closure(JSFunction* closure); |
| |
| inline Context* previous(); |
| inline void set_previous(Context* context); |
| |
| inline bool has_extension(); |
| inline HeapObject* extension(); |
| inline void set_extension(HeapObject* object); |
| JSObject* extension_object(); |
| JSReceiver* extension_receiver(); |
| ScopeInfo* scope_info(); |
| String* catch_name(); |
| |
| inline JSModule* module(); |
| inline void set_module(JSModule* module); |
| |
| // Get the context where var declarations will be hoisted to, which |
| // may be the context itself. |
| Context* declaration_context(); |
| bool is_declaration_context(); |
| |
| // Get the next closure's context on the context chain. |
| Context* closure_context(); |
| |
| // Returns a JSGlobalProxy object or null. |
| JSObject* global_proxy(); |
| void set_global_proxy(JSObject* global); |
| |
| // Get the JSGlobalObject object. |
| JSGlobalObject* global_object(); |
| |
| // Get the script context by traversing the context chain. |
| Context* script_context(); |
| |
| // Compute the native context. |
| inline Context* native_context(); |
| inline void set_native_context(Context* context); |
| |
| // Predicates for context types. IsNativeContext is also defined on Object |
| // because we frequently have to know if arbitrary objects are natives |
| // contexts. |
| inline bool IsNativeContext(); |
| inline bool IsFunctionContext(); |
| inline bool IsCatchContext(); |
| inline bool IsWithContext(); |
| inline bool IsBlockContext(); |
| inline bool IsModuleContext(); |
| inline bool IsScriptContext(); |
| |
| inline bool HasSameSecurityTokenAs(Context* that); |
| |
| // Initializes global variable bindings in given script context. |
| void InitializeGlobalSlots(); |
| |
| // A native context holds a list of all functions with optimized code. |
| void AddOptimizedFunction(JSFunction* function); |
| void RemoveOptimizedFunction(JSFunction* function); |
| void SetOptimizedFunctionsListHead(Object* head); |
| Object* OptimizedFunctionsListHead(); |
| |
| // The native context also stores a list of all optimized code and a |
| // list of all deoptimized code, which are needed by the deoptimizer. |
| void AddOptimizedCode(Code* code); |
| void SetOptimizedCodeListHead(Object* head); |
| Object* OptimizedCodeListHead(); |
| void SetDeoptimizedCodeListHead(Object* head); |
| Object* DeoptimizedCodeListHead(); |
| |
| Handle<Object> ErrorMessageForCodeGenerationFromStrings(); |
| |
| static int ImportedFieldIndexForName(Handle<String> name); |
| static int IntrinsicIndexForName(Handle<String> name); |
| |
| #define NATIVE_CONTEXT_FIELD_ACCESSORS(index, type, name) \ |
| inline void set_##name(type* value); \ |
| inline bool is_##name(type* value); \ |
| inline type* name(); |
| NATIVE_CONTEXT_FIELDS(NATIVE_CONTEXT_FIELD_ACCESSORS) |
| #undef NATIVE_CONTEXT_FIELD_ACCESSORS |
| |
| // Lookup the slot called name, starting with the current context. |
| // There are three possibilities: |
| // |
| // 1) result->IsContext(): |
| // The binding was found in a context. *index is always the |
| // non-negative slot index. *attributes is NONE for var and let |
| // declarations, READ_ONLY for const declarations (never ABSENT). |
| // |
| // 2) result->IsJSObject(): |
| // The binding was found as a named property in a context extension |
| // object (i.e., was introduced via eval), as a property on the subject |
| // of with, or as a property of the global object. *index is -1 and |
| // *attributes is not ABSENT. |
| // |
| // 3) result.is_null(): |
| // There was no binding found, *index is always -1 and *attributes is |
| // always ABSENT. |
| Handle<Object> Lookup(Handle<String> name, |
| ContextLookupFlags flags, |
| int* index, |
| PropertyAttributes* attributes, |
| BindingFlags* binding_flags); |
| |
| // Code generation support. |
| static int SlotOffset(int index) { |
| return kHeaderSize + index * kPointerSize - kHeapObjectTag; |
| } |
| |
| static int FunctionMapIndex(LanguageMode language_mode, FunctionKind kind) { |
| if (IsGeneratorFunction(kind)) { |
| return is_strict(language_mode) ? STRICT_GENERATOR_FUNCTION_MAP_INDEX |
| : SLOPPY_GENERATOR_FUNCTION_MAP_INDEX; |
| } |
| |
| if (IsClassConstructor(kind)) { |
| // Use strict function map (no own "caller" / "arguments") |
| return STRICT_FUNCTION_MAP_INDEX; |
| } |
| |
| if (IsArrowFunction(kind) || IsConciseMethod(kind) || |
| IsAccessorFunction(kind)) { |
| return STRICT_FUNCTION_WITHOUT_PROTOTYPE_MAP_INDEX; |
| } |
| |
| return is_strict(language_mode) ? STRICT_FUNCTION_MAP_INDEX |
| : SLOPPY_FUNCTION_MAP_INDEX; |
| } |
| |
| static int ArrayMapIndex(ElementsKind elements_kind) { |
| DCHECK(IsFastElementsKind(elements_kind)); |
| return elements_kind + FIRST_JS_ARRAY_MAP_SLOT; |
| } |
| |
| static const int kSize = kHeaderSize + NATIVE_CONTEXT_SLOTS * kPointerSize; |
| static const int kNotFound = -1; |
| |
| // GC support. |
| typedef FixedBodyDescriptor< |
| kHeaderSize, kSize, kSize> ScavengeBodyDescriptor; |
| |
| typedef FixedBodyDescriptor< |
| kHeaderSize, |
| kHeaderSize + FIRST_WEAK_SLOT * kPointerSize, |
| kSize> MarkCompactBodyDescriptor; |
| |
| private: |
| #ifdef DEBUG |
| // Bootstrapping-aware type checks. |
| static bool IsBootstrappingOrNativeContext(Isolate* isolate, Object* object); |
| static bool IsBootstrappingOrValidParentContext(Object* object, Context* kid); |
| #endif |
| |
| STATIC_ASSERT(kHeaderSize == Internals::kContextHeaderSize); |
| STATIC_ASSERT(EMBEDDER_DATA_INDEX == Internals::kContextEmbedderDataIndex); |
| }; |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_CONTEXTS_H_ |
