1 // Copyright 2012 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
9 #include "src/objects.h"
15 enum ContextLookupFlags {
16 FOLLOW_CONTEXT_CHAIN = 1,
17 FOLLOW_PROTOTYPE_CHAIN = 2,
19 DONT_FOLLOW_CHAINS = 0,
20 FOLLOW_CHAINS = FOLLOW_CONTEXT_CHAIN | FOLLOW_PROTOTYPE_CHAIN
24 // ES5 10.2 defines lexical environments with mutable and immutable bindings.
25 // Immutable bindings have two states, initialized and uninitialized, and
26 // their state is changed by the InitializeImmutableBinding method. The
27 // BindingFlags enum represents information if a binding has definitely been
28 // initialized. A mutable binding does not need to be checked and thus has
29 // the BindingFlag MUTABLE_IS_INITIALIZED.
31 // There are two possibilities for immutable bindings
32 // * 'const' declared variables. They are initialized when evaluating the
33 // corresponding declaration statement. They need to be checked for being
34 // initialized and thus get the flag IMMUTABLE_CHECK_INITIALIZED.
35 // * The function name of a named function literal. The binding is immediately
36 // initialized when entering the function and thus does not need to be
37 // checked. it gets the BindingFlag IMMUTABLE_IS_INITIALIZED.
38 // Accessing an uninitialized binding produces the undefined value.
40 // The harmony proposal for block scoped bindings also introduces the
41 // uninitialized state for mutable bindings.
42 // * A 'let' declared variable. They are initialized when evaluating the
43 // corresponding declaration statement. They need to be checked for being
44 // initialized and thus get the flag MUTABLE_CHECK_INITIALIZED.
45 // * A 'var' declared variable. It is initialized immediately upon creation
46 // and thus doesn't need to be checked. It gets the flag
47 // MUTABLE_IS_INITIALIZED.
48 // * Catch bound variables, function parameters and variables introduced by
49 // function declarations are initialized immediately and do not need to be
50 // checked. Thus they get the flag MUTABLE_IS_INITIALIZED.
51 // Immutable bindings in harmony mode get the _HARMONY flag variants. Accessing
52 // an uninitialized binding produces a reference error.
54 // In V8 uninitialized bindings are set to the hole value upon creation and set
55 // to a different value upon initialization.
57 MUTABLE_IS_INITIALIZED,
58 MUTABLE_CHECK_INITIALIZED,
59 IMMUTABLE_IS_INITIALIZED,
60 IMMUTABLE_CHECK_INITIALIZED,
61 IMMUTABLE_IS_INITIALIZED_HARMONY,
62 IMMUTABLE_CHECK_INITIALIZED_HARMONY,
67 // Heap-allocated activation contexts.
69 // Contexts are implemented as FixedArray objects; the Context
70 // class is a convenience interface casted on a FixedArray object.
72 // Note: Context must have no virtual functions and Context objects
73 // must always be allocated via Heap::AllocateContext() or
74 // Factory::NewContext.
76 #define NATIVE_CONTEXT_FIELDS(V) \
77 V(GLOBAL_PROXY_INDEX, JSObject, global_proxy_object) \
78 V(SECURITY_TOKEN_INDEX, Object, security_token) \
79 V(BOOLEAN_FUNCTION_INDEX, JSFunction, boolean_function) \
80 V(NUMBER_FUNCTION_INDEX, JSFunction, number_function) \
81 V(STRING_FUNCTION_INDEX, JSFunction, string_function) \
82 V(STRING_FUNCTION_PROTOTYPE_MAP_INDEX, Map, string_function_prototype_map) \
83 V(SYMBOL_FUNCTION_INDEX, JSFunction, symbol_function) \
84 V(OBJECT_FUNCTION_INDEX, JSFunction, object_function) \
85 V(INTERNAL_ARRAY_FUNCTION_INDEX, JSFunction, internal_array_function) \
86 V(ARRAY_FUNCTION_INDEX, JSFunction, array_function) \
87 V(JS_ARRAY_MAPS_INDEX, Object, js_array_maps) \
88 V(DATE_FUNCTION_INDEX, JSFunction, date_function) \
89 V(JSON_OBJECT_INDEX, JSObject, json_object) \
90 V(REGEXP_FUNCTION_INDEX, JSFunction, regexp_function) \
91 V(INITIAL_OBJECT_PROTOTYPE_INDEX, JSObject, initial_object_prototype) \
92 V(INITIAL_ARRAY_PROTOTYPE_INDEX, JSObject, initial_array_prototype) \
93 V(CREATE_DATE_FUN_INDEX, JSFunction, create_date_fun) \
94 V(TO_NUMBER_FUN_INDEX, JSFunction, to_number_fun) \
95 V(TO_STRING_FUN_INDEX, JSFunction, to_string_fun) \
96 V(TO_DETAIL_STRING_FUN_INDEX, JSFunction, to_detail_string_fun) \
97 V(TO_OBJECT_FUN_INDEX, JSFunction, to_object_fun) \
98 V(TO_INTEGER_FUN_INDEX, JSFunction, to_integer_fun) \
99 V(TO_UINT32_FUN_INDEX, JSFunction, to_uint32_fun) \
100 V(TO_INT32_FUN_INDEX, JSFunction, to_int32_fun) \
101 V(GLOBAL_EVAL_FUN_INDEX, JSFunction, global_eval_fun) \
102 V(INSTANTIATE_FUN_INDEX, JSFunction, instantiate_fun) \
103 V(CONFIGURE_INSTANCE_FUN_INDEX, JSFunction, configure_instance_fun) \
104 V(ARRAY_BUFFER_FUN_INDEX, JSFunction, array_buffer_fun) \
105 V(UINT8_ARRAY_FUN_INDEX, JSFunction, uint8_array_fun) \
106 V(INT8_ARRAY_FUN_INDEX, JSFunction, int8_array_fun) \
107 V(UINT16_ARRAY_FUN_INDEX, JSFunction, uint16_array_fun) \
108 V(INT16_ARRAY_FUN_INDEX, JSFunction, int16_array_fun) \
109 V(UINT32_ARRAY_FUN_INDEX, JSFunction, uint32_array_fun) \
110 V(INT32_ARRAY_FUN_INDEX, JSFunction, int32_array_fun) \
111 V(FLOAT32_ARRAY_FUN_INDEX, JSFunction, float32_array_fun) \
112 V(FLOAT64_ARRAY_FUN_INDEX, JSFunction, float64_array_fun) \
113 V(UINT8_CLAMPED_ARRAY_FUN_INDEX, JSFunction, uint8_clamped_array_fun) \
114 V(INT8_ARRAY_EXTERNAL_MAP_INDEX, Map, int8_array_external_map) \
115 V(UINT8_ARRAY_EXTERNAL_MAP_INDEX, Map, uint8_array_external_map) \
116 V(INT16_ARRAY_EXTERNAL_MAP_INDEX, Map, int16_array_external_map) \
117 V(UINT16_ARRAY_EXTERNAL_MAP_INDEX, Map, uint16_array_external_map) \
118 V(INT32_ARRAY_EXTERNAL_MAP_INDEX, Map, int32_array_external_map) \
119 V(UINT32_ARRAY_EXTERNAL_MAP_INDEX, Map, uint32_array_external_map) \
120 V(FLOAT32_ARRAY_EXTERNAL_MAP_INDEX, Map, float32_array_external_map) \
121 V(FLOAT64_ARRAY_EXTERNAL_MAP_INDEX, Map, float64_array_external_map) \
122 V(UINT8_CLAMPED_ARRAY_EXTERNAL_MAP_INDEX, Map, \
123 uint8_clamped_array_external_map) \
124 V(DATA_VIEW_FUN_INDEX, JSFunction, data_view_fun) \
125 V(SLOPPY_FUNCTION_MAP_INDEX, Map, sloppy_function_map) \
126 V(SLOPPY_FUNCTION_WITH_READONLY_PROTOTYPE_MAP_INDEX, Map, \
127 sloppy_function_with_readonly_prototype_map) \
128 V(STRICT_FUNCTION_MAP_INDEX, Map, strict_function_map) \
129 V(SLOPPY_FUNCTION_WITHOUT_PROTOTYPE_MAP_INDEX, Map, \
130 sloppy_function_without_prototype_map) \
131 V(STRICT_FUNCTION_WITHOUT_PROTOTYPE_MAP_INDEX, Map, \
132 strict_function_without_prototype_map) \
133 V(BOUND_FUNCTION_MAP_INDEX, Map, bound_function_map) \
134 V(REGEXP_RESULT_MAP_INDEX, Map, regexp_result_map)\
135 V(SLOPPY_ARGUMENTS_BOILERPLATE_INDEX, JSObject, \
136 sloppy_arguments_boilerplate) \
137 V(ALIASED_ARGUMENTS_BOILERPLATE_INDEX, JSObject, \
138 aliased_arguments_boilerplate) \
139 V(STRICT_ARGUMENTS_BOILERPLATE_INDEX, JSObject, \
140 strict_arguments_boilerplate) \
141 V(MESSAGE_LISTENERS_INDEX, JSObject, message_listeners) \
142 V(MAKE_MESSAGE_FUN_INDEX, JSFunction, make_message_fun) \
143 V(GET_STACK_TRACE_LINE_INDEX, JSFunction, get_stack_trace_line_fun) \
144 V(CONFIGURE_GLOBAL_INDEX, JSFunction, configure_global_fun) \
145 V(FUNCTION_CACHE_INDEX, JSObject, function_cache) \
146 V(JSFUNCTION_RESULT_CACHES_INDEX, FixedArray, jsfunction_result_caches) \
147 V(NORMALIZED_MAP_CACHE_INDEX, NormalizedMapCache, normalized_map_cache) \
148 V(RUNTIME_CONTEXT_INDEX, Context, runtime_context) \
149 V(CALL_AS_FUNCTION_DELEGATE_INDEX, JSFunction, call_as_function_delegate) \
150 V(CALL_AS_CONSTRUCTOR_DELEGATE_INDEX, JSFunction, \
151 call_as_constructor_delegate) \
152 V(SCRIPT_FUNCTION_INDEX, JSFunction, script_function) \
153 V(OPAQUE_REFERENCE_FUNCTION_INDEX, JSFunction, opaque_reference_function) \
154 V(CONTEXT_EXTENSION_FUNCTION_INDEX, JSFunction, context_extension_function) \
155 V(MAP_CACHE_INDEX, Object, map_cache) \
156 V(EMBEDDER_DATA_INDEX, FixedArray, embedder_data) \
157 V(ALLOW_CODE_GEN_FROM_STRINGS_INDEX, Object, allow_code_gen_from_strings) \
158 V(ERROR_MESSAGE_FOR_CODE_GEN_FROM_STRINGS_INDEX, Object, \
159 error_message_for_code_gen_from_strings) \
160 V(IS_PROMISE_INDEX, JSFunction, is_promise) \
161 V(PROMISE_CREATE_INDEX, JSFunction, promise_create) \
162 V(PROMISE_RESOLVE_INDEX, JSFunction, promise_resolve) \
163 V(PROMISE_REJECT_INDEX, JSFunction, promise_reject) \
164 V(PROMISE_CHAIN_INDEX, JSFunction, promise_chain) \
165 V(PROMISE_CATCH_INDEX, JSFunction, promise_catch) \
166 V(PROMISE_THEN_INDEX, JSFunction, promise_then) \
167 V(TO_COMPLETE_PROPERTY_DESCRIPTOR_INDEX, JSFunction, \
168 to_complete_property_descriptor) \
169 V(DERIVED_HAS_TRAP_INDEX, JSFunction, derived_has_trap) \
170 V(DERIVED_GET_TRAP_INDEX, JSFunction, derived_get_trap) \
171 V(DERIVED_SET_TRAP_INDEX, JSFunction, derived_set_trap) \
172 V(PROXY_ENUMERATE_INDEX, JSFunction, proxy_enumerate) \
173 V(OBSERVERS_NOTIFY_CHANGE_INDEX, JSFunction, observers_notify_change) \
174 V(OBSERVERS_ENQUEUE_SPLICE_INDEX, JSFunction, observers_enqueue_splice) \
175 V(OBSERVERS_BEGIN_SPLICE_INDEX, JSFunction, \
176 observers_begin_perform_splice) \
177 V(OBSERVERS_END_SPLICE_INDEX, JSFunction, \
178 observers_end_perform_splice) \
179 V(NATIVE_OBJECT_OBSERVE_INDEX, JSFunction, \
180 native_object_observe) \
181 V(NATIVE_OBJECT_GET_NOTIFIER_INDEX, JSFunction, \
182 native_object_get_notifier) \
183 V(NATIVE_OBJECT_NOTIFIER_PERFORM_CHANGE, JSFunction, \
184 native_object_notifier_perform_change) \
185 V(SLOPPY_GENERATOR_FUNCTION_MAP_INDEX, Map, sloppy_generator_function_map) \
186 V(STRICT_GENERATOR_FUNCTION_MAP_INDEX, Map, strict_generator_function_map) \
187 V(GENERATOR_OBJECT_PROTOTYPE_MAP_INDEX, Map, \
188 generator_object_prototype_map) \
189 V(ITERATOR_RESULT_MAP_INDEX, Map, iterator_result_map) \
190 V(MAP_ITERATOR_MAP_INDEX, Map, map_iterator_map) \
191 V(SET_ITERATOR_MAP_INDEX, Map, set_iterator_map) \
192 V(ITERATOR_SYMBOL_INDEX, Symbol, iterator_symbol)
194 // JSFunctions are pairs (context, function code), sometimes also called
195 // closures. A Context object is used to represent function contexts and
196 // dynamically pushed 'with' contexts (or 'scopes' in ECMA-262 speak).
198 // At runtime, the contexts build a stack in parallel to the execution
199 // stack, with the top-most context being the current context. All contexts
200 // have the following slots:
202 // [ closure ] This is the current function. It is the same for all
203 // contexts inside a function. It provides access to the
204 // incoming context (i.e., the outer context, which may
205 // or may not become the current function's context), and
206 // it provides access to the functions code and thus it's
207 // scope information, which in turn contains the names of
208 // statically allocated context slots. The names are needed
209 // for dynamic lookups in the presence of 'with' or 'eval'.
211 // [ previous ] A pointer to the previous context. It is NULL for
212 // function contexts, and non-NULL for 'with' contexts.
213 // Used to implement the 'with' statement.
215 // [ extension ] A pointer to an extension JSObject, or NULL. Used to
216 // implement 'with' statements and dynamic declarations
217 // (through 'eval'). The object in a 'with' statement is
218 // stored in the extension slot of a 'with' context.
219 // Dynamically declared variables/functions are also added
220 // to lazily allocated extension object. Context::Lookup
221 // searches the extension object for properties.
222 // For global and block contexts, contains the respective
224 // For module contexts, points back to the respective JSModule.
226 // [ global_object ] A pointer to the global object. Provided for quick
227 // access to the global object from inside the code (since
228 // we always have a context pointer).
230 // In addition, function contexts may have statically allocated context slots
231 // to store local variables/functions that are accessed from inner functions
232 // (via static context addresses) or through 'eval' (dynamic context lookups).
233 // The native context contains additional slots for fast access to native
236 // Finally, with Harmony scoping, the JSFunction representing a top level
237 // script will have the GlobalContext rather than a FunctionContext.
239 class Context: public FixedArray {
242 static Context* cast(Object* context) {
243 ASSERT(context->IsContext());
244 return reinterpret_cast<Context*>(context);
247 // The default context slot layout; indices are FixedArray slot indices.
249 // These slots are in all contexts.
252 // The extension slot is used for either the global object (in global
253 // contexts), eval extension object (function contexts), subject of with
254 // (with contexts), or the variable name (catch contexts), the serialized
255 // scope info (block contexts), or the module instance (module contexts).
260 // This slot holds the thrown value in catch contexts.
261 THROWN_OBJECT_INDEX = MIN_CONTEXT_SLOTS,
263 // These slots are only in native contexts.
264 GLOBAL_PROXY_INDEX = MIN_CONTEXT_SLOTS,
265 SECURITY_TOKEN_INDEX,
266 SLOPPY_ARGUMENTS_BOILERPLATE_INDEX,
267 ALIASED_ARGUMENTS_BOILERPLATE_INDEX,
268 STRICT_ARGUMENTS_BOILERPLATE_INDEX,
269 REGEXP_RESULT_MAP_INDEX,
270 SLOPPY_FUNCTION_MAP_INDEX,
271 SLOPPY_FUNCTION_WITH_READONLY_PROTOTYPE_MAP_INDEX,
272 STRICT_FUNCTION_MAP_INDEX,
273 SLOPPY_FUNCTION_WITHOUT_PROTOTYPE_MAP_INDEX,
274 STRICT_FUNCTION_WITHOUT_PROTOTYPE_MAP_INDEX,
275 BOUND_FUNCTION_MAP_INDEX,
276 INITIAL_OBJECT_PROTOTYPE_INDEX,
277 INITIAL_ARRAY_PROTOTYPE_INDEX,
278 BOOLEAN_FUNCTION_INDEX,
279 NUMBER_FUNCTION_INDEX,
280 STRING_FUNCTION_INDEX,
281 STRING_FUNCTION_PROTOTYPE_MAP_INDEX,
282 SYMBOL_FUNCTION_INDEX,
283 OBJECT_FUNCTION_INDEX,
284 INTERNAL_ARRAY_FUNCTION_INDEX,
285 ARRAY_FUNCTION_INDEX,
289 REGEXP_FUNCTION_INDEX,
290 CREATE_DATE_FUN_INDEX,
293 TO_DETAIL_STRING_FUN_INDEX,
295 TO_INTEGER_FUN_INDEX,
298 TO_BOOLEAN_FUN_INDEX,
299 GLOBAL_EVAL_FUN_INDEX,
300 INSTANTIATE_FUN_INDEX,
301 CONFIGURE_INSTANCE_FUN_INDEX,
302 ARRAY_BUFFER_FUN_INDEX,
303 UINT8_ARRAY_FUN_INDEX,
304 INT8_ARRAY_FUN_INDEX,
305 UINT16_ARRAY_FUN_INDEX,
306 INT16_ARRAY_FUN_INDEX,
307 UINT32_ARRAY_FUN_INDEX,
308 INT32_ARRAY_FUN_INDEX,
309 FLOAT32_ARRAY_FUN_INDEX,
310 FLOAT64_ARRAY_FUN_INDEX,
311 UINT8_CLAMPED_ARRAY_FUN_INDEX,
312 INT8_ARRAY_EXTERNAL_MAP_INDEX,
313 UINT8_ARRAY_EXTERNAL_MAP_INDEX,
314 INT16_ARRAY_EXTERNAL_MAP_INDEX,
315 UINT16_ARRAY_EXTERNAL_MAP_INDEX,
316 INT32_ARRAY_EXTERNAL_MAP_INDEX,
317 UINT32_ARRAY_EXTERNAL_MAP_INDEX,
318 FLOAT32_ARRAY_EXTERNAL_MAP_INDEX,
319 FLOAT64_ARRAY_EXTERNAL_MAP_INDEX,
320 UINT8_CLAMPED_ARRAY_EXTERNAL_MAP_INDEX,
322 MESSAGE_LISTENERS_INDEX,
323 MAKE_MESSAGE_FUN_INDEX,
324 GET_STACK_TRACE_LINE_INDEX,
325 CONFIGURE_GLOBAL_INDEX,
326 FUNCTION_CACHE_INDEX,
327 JSFUNCTION_RESULT_CACHES_INDEX,
328 NORMALIZED_MAP_CACHE_INDEX,
329 RUNTIME_CONTEXT_INDEX,
330 CALL_AS_FUNCTION_DELEGATE_INDEX,
331 CALL_AS_CONSTRUCTOR_DELEGATE_INDEX,
332 SCRIPT_FUNCTION_INDEX,
333 OPAQUE_REFERENCE_FUNCTION_INDEX,
334 CONTEXT_EXTENSION_FUNCTION_INDEX,
337 ALLOW_CODE_GEN_FROM_STRINGS_INDEX,
338 ERROR_MESSAGE_FOR_CODE_GEN_FROM_STRINGS_INDEX,
339 RUN_MICROTASKS_INDEX,
340 ENQUEUE_MICROTASK_INDEX,
342 PROMISE_CREATE_INDEX,
343 PROMISE_RESOLVE_INDEX,
344 PROMISE_REJECT_INDEX,
348 TO_COMPLETE_PROPERTY_DESCRIPTOR_INDEX,
349 DERIVED_HAS_TRAP_INDEX,
350 DERIVED_GET_TRAP_INDEX,
351 DERIVED_SET_TRAP_INDEX,
352 PROXY_ENUMERATE_INDEX,
353 OBSERVERS_NOTIFY_CHANGE_INDEX,
354 OBSERVERS_ENQUEUE_SPLICE_INDEX,
355 OBSERVERS_BEGIN_SPLICE_INDEX,
356 OBSERVERS_END_SPLICE_INDEX,
357 NATIVE_OBJECT_OBSERVE_INDEX,
358 NATIVE_OBJECT_GET_NOTIFIER_INDEX,
359 NATIVE_OBJECT_NOTIFIER_PERFORM_CHANGE,
360 SLOPPY_GENERATOR_FUNCTION_MAP_INDEX,
361 STRICT_GENERATOR_FUNCTION_MAP_INDEX,
362 GENERATOR_OBJECT_PROTOTYPE_MAP_INDEX,
363 ITERATOR_RESULT_MAP_INDEX,
364 MAP_ITERATOR_MAP_INDEX,
365 SET_ITERATOR_MAP_INDEX,
366 ITERATOR_SYMBOL_INDEX,
368 // Properties from here are treated as weak references by the full GC.
369 // Scavenge treats them as strong references.
370 OPTIMIZED_FUNCTIONS_LIST, // Weak.
371 OPTIMIZED_CODE_LIST, // Weak.
372 DEOPTIMIZED_CODE_LIST, // Weak.
373 MAP_CACHE_INDEX, // Weak.
374 NEXT_CONTEXT_LINK, // Weak.
376 // Total number of slots.
377 NATIVE_CONTEXT_SLOTS,
379 FIRST_WEAK_SLOT = OPTIMIZED_FUNCTIONS_LIST
382 // Direct slot access.
383 JSFunction* closure() { return JSFunction::cast(get(CLOSURE_INDEX)); }
384 void set_closure(JSFunction* closure) { set(CLOSURE_INDEX, closure); }
386 Context* previous() {
387 Object* result = unchecked_previous();
388 ASSERT(IsBootstrappingOrValidParentContext(result, this));
389 return reinterpret_cast<Context*>(result);
391 void set_previous(Context* context) { set(PREVIOUS_INDEX, context); }
393 bool has_extension() { return extension() != NULL; }
394 Object* extension() { return get(EXTENSION_INDEX); }
395 void set_extension(Object* object) { set(EXTENSION_INDEX, object); }
397 JSModule* module() { return JSModule::cast(get(EXTENSION_INDEX)); }
398 void set_module(JSModule* module) { set(EXTENSION_INDEX, module); }
400 // Get the context where var declarations will be hoisted to, which
401 // may be the context itself.
402 Context* declaration_context();
404 GlobalObject* global_object() {
405 Object* result = get(GLOBAL_OBJECT_INDEX);
406 ASSERT(IsBootstrappingOrGlobalObject(this->GetIsolate(), result));
407 return reinterpret_cast<GlobalObject*>(result);
409 void set_global_object(GlobalObject* object) {
410 set(GLOBAL_OBJECT_INDEX, object);
413 // Returns a JSGlobalProxy object or null.
414 JSObject* global_proxy();
415 void set_global_proxy(JSObject* global);
417 // The builtins object.
418 JSBuiltinsObject* builtins();
420 // Get the innermost global context by traversing the context chain.
421 Context* global_context();
423 // Compute the native context by traversing the context chain.
424 Context* native_context();
426 // Predicates for context types. IsNativeContext is also defined on Object
427 // because we frequently have to know if arbitrary objects are natives
429 bool IsNativeContext() {
430 Map* map = this->map();
431 return map == map->GetHeap()->native_context_map();
433 bool IsFunctionContext() {
434 Map* map = this->map();
435 return map == map->GetHeap()->function_context_map();
437 bool IsCatchContext() {
438 Map* map = this->map();
439 return map == map->GetHeap()->catch_context_map();
441 bool IsWithContext() {
442 Map* map = this->map();
443 return map == map->GetHeap()->with_context_map();
445 bool IsBlockContext() {
446 Map* map = this->map();
447 return map == map->GetHeap()->block_context_map();
449 bool IsModuleContext() {
450 Map* map = this->map();
451 return map == map->GetHeap()->module_context_map();
453 bool IsGlobalContext() {
454 Map* map = this->map();
455 return map == map->GetHeap()->global_context_map();
458 bool HasSameSecurityTokenAs(Context* that) {
459 return this->global_object()->native_context()->security_token() ==
460 that->global_object()->native_context()->security_token();
463 // A native context holds a list of all functions with optimized code.
464 void AddOptimizedFunction(JSFunction* function);
465 void RemoveOptimizedFunction(JSFunction* function);
466 void SetOptimizedFunctionsListHead(Object* head);
467 Object* OptimizedFunctionsListHead();
469 // The native context also stores a list of all optimized code and a
470 // list of all deoptimized code, which are needed by the deoptimizer.
471 void AddOptimizedCode(Code* code);
472 void SetOptimizedCodeListHead(Object* head);
473 Object* OptimizedCodeListHead();
474 void SetDeoptimizedCodeListHead(Object* head);
475 Object* DeoptimizedCodeListHead();
477 Handle<Object> ErrorMessageForCodeGenerationFromStrings();
479 #define NATIVE_CONTEXT_FIELD_ACCESSORS(index, type, name) \
480 void set_##name(type* value) { \
481 ASSERT(IsNativeContext()); \
484 bool is_##name(type* value) { \
485 ASSERT(IsNativeContext()); \
486 return type::cast(get(index)) == value; \
489 ASSERT(IsNativeContext()); \
490 return type::cast(get(index)); \
492 NATIVE_CONTEXT_FIELDS(NATIVE_CONTEXT_FIELD_ACCESSORS)
493 #undef NATIVE_CONTEXT_FIELD_ACCESSORS
495 // Lookup the slot called name, starting with the current context.
496 // There are three possibilities:
498 // 1) result->IsContext():
499 // The binding was found in a context. *index is always the
500 // non-negative slot index. *attributes is NONE for var and let
501 // declarations, READ_ONLY for const declarations (never ABSENT).
503 // 2) result->IsJSObject():
504 // The binding was found as a named property in a context extension
505 // object (i.e., was introduced via eval), as a property on the subject
506 // of with, or as a property of the global object. *index is -1 and
507 // *attributes is not ABSENT.
509 // 3) result.is_null():
510 // There was no binding found, *index is always -1 and *attributes is
512 Handle<Object> Lookup(Handle<String> name,
513 ContextLookupFlags flags,
515 PropertyAttributes* attributes,
516 BindingFlags* binding_flags);
518 // Code generation support.
519 static int SlotOffset(int index) {
520 return kHeaderSize + index * kPointerSize - kHeapObjectTag;
523 static int FunctionMapIndex(StrictMode strict_mode, bool is_generator) {
525 ? (strict_mode == SLOPPY
526 ? SLOPPY_GENERATOR_FUNCTION_MAP_INDEX
527 : STRICT_GENERATOR_FUNCTION_MAP_INDEX)
528 : (strict_mode == SLOPPY
529 ? SLOPPY_FUNCTION_MAP_INDEX
530 : STRICT_FUNCTION_MAP_INDEX);
533 static const int kSize = kHeaderSize + NATIVE_CONTEXT_SLOTS * kPointerSize;
536 typedef FixedBodyDescriptor<
537 kHeaderSize, kSize, kSize> ScavengeBodyDescriptor;
539 typedef FixedBodyDescriptor<
541 kHeaderSize + FIRST_WEAK_SLOT * kPointerSize,
542 kSize> MarkCompactBodyDescriptor;
545 // Unchecked access to the slots.
546 Object* unchecked_previous() { return get(PREVIOUS_INDEX); }
549 // Bootstrapping-aware type checks.
550 static bool IsBootstrappingOrValidParentContext(Object* object, Context* kid);
551 static bool IsBootstrappingOrGlobalObject(Isolate* isolate, Object* object);
554 STATIC_ASSERT(kHeaderSize == Internals::kContextHeaderSize);
555 STATIC_ASSERT(EMBEDDER_DATA_INDEX == Internals::kContextEmbedderDataIndex);
558 } } // namespace v8::internal
560 #endif // V8_CONTEXTS_H_