| // Copyright 2017 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_OBJECTS_ARGUMENTS_H_ |
| #define V8_OBJECTS_ARGUMENTS_H_ |
| |
| #include "src/objects/fixed-array.h" |
| #include "src/objects/js-objects.h" |
| #include "src/objects/struct.h" |
| #include "torque-generated/field-offsets-tq.h" |
| |
| // Has to be the last include (doesn't have include guards): |
| #include "src/objects/object-macros.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| // Superclass for all objects with instance type {JS_ARGUMENTS_TYPE} |
| class JSArgumentsObject : public JSObject { |
| public: |
| DECL_VERIFIER(JSArgumentsObject) |
| DECL_CAST(JSArgumentsObject) |
| OBJECT_CONSTRUCTORS(JSArgumentsObject, JSObject); |
| }; |
| |
| // Common superclass for JSSloppyArgumentsObject and JSStrictArgumentsObject. |
| // Note that the instance type {JS_ARGUMENTS_TYPE} does _not_ guarantee the |
| // below layout, the in-object properties might have transitioned to dictionary |
| // mode already. Only use the below layout with the specific initial maps. |
| class JSArgumentsObjectWithLength : public JSArgumentsObject { |
| public: |
| // Layout description. |
| DEFINE_FIELD_OFFSET_CONSTANTS( |
| JSObject::kHeaderSize, |
| TORQUE_GENERATED_JSARGUMENTS_OBJECT_WITH_LENGTH_FIELDS) |
| |
| // Indices of in-object properties. |
| static const int kLengthIndex = 0; |
| |
| DECL_VERIFIER(JSArgumentsObjectWithLength) |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(JSArgumentsObjectWithLength); |
| }; |
| |
| // JSSloppyArgumentsObject is just a JSObject with specific initial map. |
| // This initial map adds in-object properties for "length" and "callee". |
| class JSSloppyArgumentsObject : public JSArgumentsObjectWithLength { |
| public: |
| DEFINE_FIELD_OFFSET_CONSTANTS( |
| JSArgumentsObjectWithLength::kSize, |
| TORQUE_GENERATED_JSSLOPPY_ARGUMENTS_OBJECT_FIELDS) |
| |
| // Indices of in-object properties. |
| static const int kCalleeIndex = kLengthIndex + 1; |
| |
| inline static bool GetSloppyArgumentsLength(Isolate* isolate, |
| Handle<JSObject> object, |
| int* out); |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(JSSloppyArgumentsObject); |
| }; |
| |
| // JSStrictArgumentsObject is just a JSObject with specific initial map. |
| // This initial map adds an in-object property for "length". |
| class JSStrictArgumentsObject : public JSArgumentsObjectWithLength { |
| public: |
| // Layout description. |
| static const int kSize = JSArgumentsObjectWithLength::kSize; |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(JSStrictArgumentsObject); |
| }; |
| |
| // Helper class to access FAST_ and SLOW_SLOPPY_ARGUMENTS_ELEMENTS |
| // |
| // +---+-----------------------+ |
| // | 0 | Context context | |
| // +---------------------------+ |
| // | 1 | FixedArray arguments +----+ HOLEY_ELEMENTS |
| // +---------------------------+ v-----+-----------+ |
| // | 2 | Object param_1_map | | 0 | the_hole | |
| // |...| ... | | ... | ... | |
| // |n+1| Object param_n_map | | n-1 | the_hole | |
| // +---------------------------+ | n | element_1 | |
| // | ... | ... | |
| // |n+m-1| element_m | |
| // +-----------------+ |
| // |
| // Parameter maps give the index into the provided context. If a map entry is |
| // the_hole it means that the given entry has been deleted from the arguments |
| // object. |
| // The arguments backing store kind depends on the ElementsKind of the outer |
| // JSArgumentsObject: |
| // - FAST_SLOPPY_ARGUMENTS_ELEMENTS: HOLEY_ELEMENTS |
| // - SLOW_SLOPPY_ARGUMENTS_ELEMENTS: DICTIONARY_ELEMENTS |
| class SloppyArgumentsElements : public FixedArray { |
| public: |
| static const int kContextIndex = 0; |
| static const int kArgumentsIndex = 1; |
| static const uint32_t kParameterMapStart = 2; |
| |
| DECL_GETTER(context, Context) |
| DECL_GETTER(arguments, FixedArray) |
| inline void set_arguments(FixedArray arguments); |
| inline uint32_t parameter_map_length(); |
| inline Object get_mapped_entry(uint32_t entry); |
| inline void set_mapped_entry(uint32_t entry, Object object); |
| |
| DECL_CAST(SloppyArgumentsElements) |
| #ifdef VERIFY_HEAP |
| void SloppyArgumentsElementsVerify(Isolate* isolate, JSObject holder); |
| #endif |
| |
| OBJECT_CONSTRUCTORS(SloppyArgumentsElements, FixedArray); |
| }; |
| |
| // Representation of a slow alias as part of a sloppy arguments objects. |
| // For fast aliases (if HasSloppyArgumentsElements()): |
| // - the parameter map contains an index into the context |
| // - all attributes of the element have default values |
| // For slow aliases (if HasDictionaryArgumentsElements()): |
| // - the parameter map contains no fast alias mapping (i.e. the hole) |
| // - this struct (in the slow backing store) contains an index into the context |
| // - all attributes are available as part if the property details |
| class AliasedArgumentsEntry : public Struct { |
| public: |
| inline int aliased_context_slot() const; |
| inline void set_aliased_context_slot(int count); |
| |
| DECL_CAST(AliasedArgumentsEntry) |
| |
| // Dispatched behavior. |
| DECL_PRINTER(AliasedArgumentsEntry) |
| DECL_VERIFIER(AliasedArgumentsEntry) |
| |
| DEFINE_FIELD_OFFSET_CONSTANTS(HeapObject::kHeaderSize, |
| TORQUE_GENERATED_ALIASED_ARGUMENTS_ENTRY_FIELDS) |
| |
| OBJECT_CONSTRUCTORS(AliasedArgumentsEntry, Struct); |
| }; |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #include "src/objects/object-macros-undef.h" |
| |
| #endif // V8_OBJECTS_ARGUMENTS_H_ |