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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef builtin_TypedObject_h
#define builtin_TypedObject_h
#include "mozilla/CheckedInt.h"
#include "builtin/TypedObjectConstants.h"
#include "gc/Allocator.h"
#include "gc/WeakMap.h"
#include "js/Conversions.h"
#include "vm/ArrayBufferObject.h"
#include "vm/JSObject.h"
/*
* -------------
* [SMDOC] Typed Objects
* -------------
*
* Typed objects are a special kind of JS object where the data is
* given well-structured form. To use a typed object, users first
* create *type objects* (no relation to the type objects used in TI)
* that define the type layout. For example, a statement like:
*
* var PointType = new StructType({x: uint8, y: uint8});
*
* would create a type object PointType that is a struct with
* two fields, each of uint8 type.
*
* This comment typically assumes familiary with the API. For more
* info on the API itself, see the Harmony wiki page at
* ES6 spec (not finalized at the time of this writing).
*
* - Initialization:
*
* Currently, all "globals" related to typed objects are packaged
* within a single "module" object `TypedObject`. This module has its
* own JSClass and when that class is initialized, we also create
* and define all other values (in `js::InitTypedObjectModuleClass()`).
*
* - Type objects, meta type objects, and type representations:
*
* There are a number of pre-defined type objects, one for each
* scalar type (`uint8` etc). Each of these has its own class_,
* defined in `DefineNumericClass()`.
*
* There are also meta type objects (`ArrayType`, `StructType`).
* These constructors are not themselves type objects but rather the
* means for the *user* to construct new typed objects.
*
* Each type object is associated with a *type representation* (see
* TypeRepresentation.h). Type representations are canonical versions
* of type objects. We attach them to TI type objects and (eventually)
* use them for shape guards etc. They are purely internal to the
* engine and are not exposed to end users (though self-hosted code
* sometimes accesses them).
*
* - Typed objects:
*
* A typed object is an instance of a *type object* (note the past participle).
* Typed objects can be either transparent or opaque, depending on whether
* their underlying buffer can be accessed. Transparent and opaque typed
* objects have different classes, and can have different physical layouts.
* The following layouts are possible:
*
* InlineTypedObject: Typed objects whose data immediately follows the object's
* header are inline typed objects. The buffer for these objects is created
* lazily and stored via the compartment's LazyArrayBufferTable, and points
* back into the object's internal data.
*
* OutlineTypedObject: Typed objects whose data is owned by another object,
* which can be either an array buffer or an inline typed object. Outline
* typed objects may be attached or unattached. An unattached typed object
* has no data associated with it. When first created, objects are always
* attached, but they can become unattached if their buffer becomes detached.
*
* Note that whether a typed object is opaque is not directly
* connected to its type. That is, opaque types are *always*
* represented by opaque typed objects, but you may have opaque typed
* objects for transparent types too. This can occur for two reasons:
* (1) a transparent type may be embedded within an opaque type or (2)
* users can choose to convert transparent typed objects into opaque
* ones to avoid giving access to the buffer itself.
*
* Typed objects (no matter their class) are non-native objects that
* fully override the property accessors etc. The overridden accessor
* methods are the same in each and are defined in methods of
* TypedObject.
*/
namespace js {
/*
* Helper method for converting a double into other scalar
* types in the same way that JavaScript would. In particular,
* simple C casting from double to int32_t gets things wrong
* for values like 0xF0000000.
*/
template <typename T>
static T ConvertScalar(double d) {
if (TypeIsFloatingPoint<T>()) {
return T(d);
}
if (TypeIsUnsigned<T>()) {
uint32_t n = JS::ToUint32(d);
return T(n);
}
int32_t n = JS::ToInt32(d);
return T(n);
}
namespace type {
enum Kind {
Scalar = JS_TYPEREPR_SCALAR_KIND,
Reference = JS_TYPEREPR_REFERENCE_KIND,
Struct = JS_TYPEREPR_STRUCT_KIND,
Array = JS_TYPEREPR_ARRAY_KIND
};
} // namespace type
///////////////////////////////////////////////////////////////////////////
// Typed Prototypes
class SimpleTypeDescr;
class ComplexTypeDescr;
class StructTypeDescr;
class TypedProto;
/*
* The prototype for a typed object.
*/
class TypedProto : public NativeObject {
public:
static const JSClass class_;
};
class TypeDescr : public NativeObject {
public:
TypedProto& typedProto() const {
return getReservedSlot(JS_DESCR_SLOT_TYPROTO).toObject().as<TypedProto>();
}
JSAtom& stringRepr() const {
return getReservedSlot(JS_DESCR_SLOT_STRING_REPR).toString()->asAtom();
}
type::Kind kind() const {
return (type::Kind)getReservedSlot(JS_DESCR_SLOT_KIND).toInt32();
}
bool opaque() const {
return getReservedSlot(JS_DESCR_SLOT_OPAQUE).toBoolean();
}
bool transparent() const { return !opaque(); }
uint32_t alignment() const {
int32_t i = getReservedSlot(JS_DESCR_SLOT_ALIGNMENT).toInt32();
MOZ_ASSERT(i >= 0);
return uint32_t(i);
}
uint32_t size() const {
int32_t i = getReservedSlot(JS_DESCR_SLOT_SIZE).toInt32();
MOZ_ASSERT(i >= 0);
return uint32_t(i);
}
// Whether id is an 'own' property of objects with this descriptor.
MOZ_MUST_USE bool hasProperty(const JSAtomState& names, jsid id);
// Type descriptors may contain a list of their references for use during
// scanning. Marking code is optimized to use this list to mark inline
// typed objects, rather than the slower trace hook. This list is only
// specified when (a) the descriptor is short enough that it can fit in an
// InlineTypedObject, and (b) the descriptor contains at least one
// reference. Otherwise its value is undefined.
//
// The list is three consecutive arrays of uint32_t offsets, preceded by a
// header consisting of the length of each array. The arrays store offsets of
// string, object/anyref, and value references in the descriptor, in that
// order.
// TODO/AnyRef-boxing: once anyref has a more complicated structure, we must
// revisit this.
MOZ_MUST_USE bool hasTraceList() const {
return !getFixedSlot(JS_DESCR_SLOT_TRACE_LIST).isUndefined();
}
const uint32_t* traceList() const {
MOZ_ASSERT(hasTraceList());
return reinterpret_cast<uint32_t*>(
getFixedSlot(JS_DESCR_SLOT_TRACE_LIST).toPrivate());
}
void initInstance(const JSRuntime* rt, uint8_t* mem);
void traceInstance(JSTracer* trace, uint8_t* mem);
static void finalize(JSFreeOp* fop, JSObject* obj);
};
using HandleTypeDescr = Handle<TypeDescr*>;
class SimpleTypeDescr : public TypeDescr {};
// Type for scalar type constructors like `uint8`. All such type
// constructors share a common JSClass and JSFunctionSpec. Scalar
// types are non-opaque (their storage is visible unless combined with
// an opaque reference type.)
class ScalarTypeDescr : public SimpleTypeDescr {
public:
using Type = Scalar::Type;
static const type::Kind Kind = type::Scalar;
static const bool Opaque = false;
static uint32_t size(Type t);
static uint32_t alignment(Type t);
static const char* typeName(Type type);
static const JSClass class_;
static const JSFunctionSpec typeObjectMethods[];
Type type() const {
// Make sure the values baked into TypedObjectConstants.h line up with
// the Scalar::Type enum. We don't define Scalar::Type directly in
// terms of these constants to avoid making TypedObjectConstants.h a
// public header file.
static_assert(
Scalar::Int8 == JS_SCALARTYPEREPR_INT8,
"TypedObjectConstants.h must be consistent with Scalar::Type");
static_assert(
Scalar::Uint8 == JS_SCALARTYPEREPR_UINT8,
"TypedObjectConstants.h must be consistent with Scalar::Type");
static_assert(
Scalar::Int16 == JS_SCALARTYPEREPR_INT16,
"TypedObjectConstants.h must be consistent with Scalar::Type");
static_assert(
Scalar::Uint16 == JS_SCALARTYPEREPR_UINT16,
"TypedObjectConstants.h must be consistent with Scalar::Type");
static_assert(
Scalar::Int32 == JS_SCALARTYPEREPR_INT32,
"TypedObjectConstants.h must be consistent with Scalar::Type");
static_assert(
Scalar::Uint32 == JS_SCALARTYPEREPR_UINT32,
"TypedObjectConstants.h must be consistent with Scalar::Type");
static_assert(
Scalar::BigInt64 == JS_SCALARTYPEREPR_BIGINT64,
"TypedObjectConstants.h must be consistent with Scalar::Type");
static_assert(
Scalar::BigUint64 == JS_SCALARTYPEREPR_BIGUINT64,
"TypedObjectConstants.h must be consistent with Scalar::Type");
static_assert(
Scalar::Float32 == JS_SCALARTYPEREPR_FLOAT32,
"TypedObjectConstants.h must be consistent with Scalar::Type");
static_assert(
Scalar::Float64 == JS_SCALARTYPEREPR_FLOAT64,
"TypedObjectConstants.h must be consistent with Scalar::Type");
static_assert(
Scalar::Uint8Clamped == JS_SCALARTYPEREPR_UINT8_CLAMPED,
"TypedObjectConstants.h must be consistent with Scalar::Type");
return Type(getReservedSlot(JS_DESCR_SLOT_TYPE).toInt32());
}
static MOZ_MUST_USE bool call(JSContext* cx, unsigned argc, Value* vp);
};
// Enumerates the cases of ScalarTypeDescr::Type which have unique C
// representation and which are representable as JS Number values. In
// particular, omits Uint8Clamped since it is just a Uint8.
#define JS_FOR_EACH_UNIQUE_SCALAR_NUMBER_TYPE_REPR_CTYPE(MACRO_) \
MACRO_(Scalar::Int8, int8_t, int8) \
MACRO_(Scalar::Uint8, uint8_t, uint8) \
MACRO_(Scalar::Int16, int16_t, int16) \
MACRO_(Scalar::Uint16, uint16_t, uint16) \
MACRO_(Scalar::Int32, int32_t, int32) \
MACRO_(Scalar::Uint32, uint32_t, uint32) \
MACRO_(Scalar::Float32, float, float32) \
MACRO_(Scalar::Float64, double, float64)
// Must be in same order as the enum ScalarTypeDescr::Type:
#define JS_FOR_EACH_SCALAR_NUMBER_TYPE_REPR(MACRO_) \
JS_FOR_EACH_UNIQUE_SCALAR_NUMBER_TYPE_REPR_CTYPE(MACRO_) \
MACRO_(Scalar::Uint8Clamped, uint8_t, uint8Clamped)
#define JS_FOR_EACH_SCALAR_BIGINT_TYPE_REPR(MACRO_) \
MACRO_(Scalar::BigInt64, int64_t, bigint64) \
MACRO_(Scalar::BigUint64, uint64_t, biguint64)
// Must be in same order as the enum ScalarTypeDescr::Type:
#define JS_FOR_EACH_SCALAR_TYPE_REPR(MACRO_) \
JS_FOR_EACH_SCALAR_NUMBER_TYPE_REPR(MACRO_) \
JS_FOR_EACH_SCALAR_BIGINT_TYPE_REPR(MACRO_)
enum class ReferenceType {
TYPE_ANY = JS_REFERENCETYPEREPR_ANY,
TYPE_OBJECT = JS_REFERENCETYPEREPR_OBJECT,
TYPE_WASM_ANYREF = JS_REFERENCETYPEREPR_WASM_ANYREF,
TYPE_STRING = JS_REFERENCETYPEREPR_STRING
};
// Type for reference type constructors like `Any`, `String`, and
// `Object`. All such type constructors share a common JSClass and
// JSFunctionSpec. All these types are opaque.
class ReferenceTypeDescr : public SimpleTypeDescr {
public:
// Must match order of JS_FOR_EACH_REFERENCE_TYPE_REPR below
using Type = ReferenceType;
static const char* typeName(Type type);
static const int32_t TYPE_MAX = int32_t(ReferenceType::TYPE_STRING) + 1;
static const type::Kind Kind = type::Reference;
static const bool Opaque = true;
static const JSClass class_;
static uint32_t size(Type t);
static uint32_t alignment(Type t);
static const JSFunctionSpec typeObjectMethods[];
ReferenceType type() const {
return (ReferenceType)getReservedSlot(JS_DESCR_SLOT_TYPE).toInt32();
}
const char* typeName() const { return typeName(type()); }
static MOZ_MUST_USE bool call(JSContext* cx, unsigned argc, Value* vp);
};
// TODO/AnyRef-boxing: With boxed immediates and strings, GCPtrObject may not be
// appropriate.
#define JS_FOR_EACH_REFERENCE_TYPE_REPR(MACRO_) \
MACRO_(ReferenceType::TYPE_ANY, GCPtrValue, Any) \
MACRO_(ReferenceType::TYPE_WASM_ANYREF, GCPtrObject, WasmAnyRef) \
MACRO_(ReferenceType::TYPE_OBJECT, GCPtrObject, Object) \
MACRO_(ReferenceType::TYPE_STRING, GCPtrString, string)
// Type descriptors whose instances are objects and hence which have
// an associated `prototype` property.
class ComplexTypeDescr : public TypeDescr {
public:
// Returns the prototype that instances of this type descriptor
// will have.
TypedProto& instancePrototype() const {
return getReservedSlot(JS_DESCR_SLOT_TYPROTO).toObject().as<TypedProto>();
}
bool allowConstruct() const {
return getReservedSlot(JS_DESCR_SLOT_FLAGS).toInt32() &
JS_DESCR_FLAG_ALLOW_CONSTRUCT;
}
};
bool IsTypedObjectClass(const JSClass* clasp); // Defined below
MOZ_MUST_USE bool CreateUserSizeAndAlignmentProperties(JSContext* cx,
HandleTypeDescr obj);
class ArrayTypeDescr;
/*
* Properties and methods of the `ArrayType` meta type object. There
* is no `class_` field because `ArrayType` is just a native
* constructor function.
*/
class ArrayMetaTypeDescr : public NativeObject {
private:
// Helper for creating a new ArrayType object.
//
// - `arrayTypePrototype` - prototype for the new object to be created
// - `elementType` - type object for the elements in the array
// - `stringRepr` - canonical string representation for the array
// - `size` - length of the array
static ArrayTypeDescr* create(JSContext* cx, HandleObject arrayTypePrototype,
HandleTypeDescr elementType,
HandleAtom stringRepr, int32_t size,
int32_t length);
public:
// Properties and methods to be installed on ArrayType.prototype,
// and hence inherited by all array type objects:
static const JSPropertySpec typeObjectProperties[];
static const JSFunctionSpec typeObjectMethods[];
// Properties and methods to be installed on ArrayType.prototype.prototype,
// and hence inherited by all array *typed* objects:
static const JSPropertySpec typedObjectProperties[];
static const JSFunctionSpec typedObjectMethods[];
// This is the function that gets called when the user
// does `new ArrayType(elem)`. It produces an array type object.
static MOZ_MUST_USE bool construct(JSContext* cx, unsigned argc, Value* vp);
};
/*
* Type descriptor created by `new ArrayType(type, n)`
*/
class ArrayTypeDescr : public ComplexTypeDescr {
public:
static const JSClass class_;
static const type::Kind Kind = type::Array;
TypeDescr& elementType() const {
return getReservedSlot(JS_DESCR_SLOT_ARRAY_ELEM_TYPE)
.toObject()
.as<TypeDescr>();
}
uint32_t length() const {
int32_t i = getReservedSlot(JS_DESCR_SLOT_ARRAY_LENGTH).toInt32();
MOZ_ASSERT(i >= 0);
return uint32_t(i);
}
static int32_t offsetOfLength() {
return getFixedSlotOffset(JS_DESCR_SLOT_ARRAY_LENGTH);
}
};
struct StructFieldProps {
StructFieldProps() : isMutable(0), alignAsInt64(0), alignAsV128(0) {}
uint32_t isMutable : 1;
uint32_t alignAsInt64 : 1;
uint32_t alignAsV128 : 1;
};
/*
* Properties and methods of the `StructType` meta type object. There
* is no `class_` field because `StructType` is just a native
* constructor function.
*/
class StructMetaTypeDescr : public NativeObject {
private:
static JSObject* create(JSContext* cx, HandleObject structTypeGlobal,
HandleObject fields);
public:
// The prototype cannot be null.
// The names in `ids` must all be non-numeric.
// The type objects in `fieldTypeObjs` must all be TypeDescr objects.
static StructTypeDescr* createFromArrays(
JSContext* cx, HandleObject structTypePrototype, bool opaque,
bool allowConstruct, HandleIdVector ids, HandleValueVector fieldTypeObjs,
Vector<StructFieldProps>& fieldProps);
// Properties and methods to be installed on StructType.prototype,
// and hence inherited by all struct type objects:
static const JSPropertySpec typeObjectProperties[];
static const JSFunctionSpec typeObjectMethods[];
// Properties and methods to be installed on StructType.prototype.prototype,
// and hence inherited by all struct *typed* objects:
static const JSPropertySpec typedObjectProperties[];
static const JSFunctionSpec typedObjectMethods[];
// This is the function that gets called when the user
// does `new StructType(...)`. It produces a struct type object.
static MOZ_MUST_USE bool construct(JSContext* cx, unsigned argc, Value* vp);
class Layout {
// Can call addField() directly.
friend class StructMetaTypeDescr;
mozilla::CheckedInt32 sizeSoFar = 0;
int32_t structAlignment = 1;
mozilla::CheckedInt32 addField(int32_t fieldAlignment, int32_t fieldSize);
public:
// The field adders return the offset of the the field.
mozilla::CheckedInt32 addScalar(Scalar::Type type);
mozilla::CheckedInt32 addReference(ReferenceType type);
// The close method rounds up the structure size to the appropriate
// alignment and returns that size. If `alignment` is not NULL then
// return the structure alignment through that pointer.
mozilla::CheckedInt32 close(int32_t* alignment = nullptr);
};
};
class StructTypeDescr : public ComplexTypeDescr {
public:
static const JSClass class_;
// Returns the number of fields defined in this struct.
size_t fieldCount() const;
// Set `*out` to the index of the field named `id` and returns true,
// or return false if no such field exists.
MOZ_MUST_USE bool fieldIndex(jsid id, size_t* out) const;
// Return the name of the field at index `index`.
JSAtom& fieldName(size_t index) const;
// Return the type descr of the field at index `index`.
TypeDescr& fieldDescr(size_t index) const;
// Return the offset of the field at index `index`.
size_t fieldOffset(size_t index) const;
// Return the mutability of the field at index `index`.
bool fieldIsMutable(size_t index) const;
static bool call(JSContext* cx, unsigned argc, Value* vp);
private:
ArrayObject& fieldInfoObject(size_t slot) const {
return getReservedSlot(slot).toObject().as<ArrayObject>();
}
};
using HandleStructTypeDescr = Handle<StructTypeDescr*>;
/*
* This object exists in order to encapsulate the typed object types
* somewhat, rather than sticking them all into the global object.
* Eventually it will go away and become a module.
*/
class TypedObjectModuleObject : public NativeObject {
public:
enum Slot {
ArrayTypePrototype,
StructTypePrototype,
Int32Desc,
Int64Desc,
Float32Desc,
Float64Desc,
ObjectDesc,
WasmAnyRefDesc,
SlotCount
};
static const JSClass class_;
private:
static const ClassSpec classSpec_;
};
/* Base type for transparent and opaque typed objects. */
class TypedObject : public JSObject {
static const bool IsTypedObjectClass = true;
static MOZ_MUST_USE bool obj_getArrayElement(JSContext* cx,
Handle<TypedObject*> typedObj,
Handle<TypeDescr*> typeDescr,
uint32_t index,
MutableHandleValue vp);
protected:
static const ObjectOps objectOps_;
static MOZ_MUST_USE bool obj_lookupProperty(
JSContext* cx, HandleObject obj, HandleId id, MutableHandleObject objp,
MutableHandle<PropertyResult> propp);
static MOZ_MUST_USE bool obj_defineProperty(JSContext* cx, HandleObject obj,
HandleId id,
Handle<PropertyDescriptor> desc,
ObjectOpResult& result);
static MOZ_MUST_USE bool obj_hasProperty(JSContext* cx, HandleObject obj,
HandleId id, bool* foundp);
static MOZ_MUST_USE bool obj_getProperty(JSContext* cx, HandleObject obj,
HandleValue receiver, HandleId id,
MutableHandleValue vp);
static MOZ_MUST_USE bool obj_getElement(JSContext* cx, HandleObject obj,
HandleValue receiver, uint32_t index,
MutableHandleValue vp);
static MOZ_MUST_USE bool obj_setProperty(JSContext* cx, HandleObject obj,
HandleId id, HandleValue v,
HandleValue receiver,
ObjectOpResult& result);
static MOZ_MUST_USE bool obj_getOwnPropertyDescriptor(
JSContext* cx, HandleObject obj, HandleId id,
MutableHandle<PropertyDescriptor> desc);
static MOZ_MUST_USE bool obj_deleteProperty(JSContext* cx, HandleObject obj,
HandleId id,
ObjectOpResult& result);
uint8_t* typedMem() const;
uint8_t* typedMemBase() const;
public:
static MOZ_MUST_USE bool obj_newEnumerate(JSContext* cx, HandleObject obj,
MutableHandleIdVector properties,
bool enumerableOnly);
TypedProto& typedProto() const {
// Typed objects' prototypes can't be modified.
return staticPrototype()->as<TypedProto>();
}
TypeDescr& typeDescr() const { return group()->typeDescr(); }
static JS::Result<TypedObject*, JS::OOM&> create(JSContext* cx,
js::gc::AllocKind kind,
js::gc::InitialHeap heap,
js::HandleShape shape,
js::HandleObjectGroup group);
uint32_t offset() const;
uint32_t length() const;
uint8_t* typedMem(const JS::AutoRequireNoGC&) const { return typedMem(); }
uint32_t size() const { return typeDescr().size(); }
uint8_t* typedMem(size_t offset, const JS::AutoRequireNoGC& nogc) const {
// It seems a bit surprising that one might request an offset
// == size(), but it can happen when taking the "address of" a
// 0-sized value. (In other words, we maintain the invariant
// that `offset + size <= size()` -- this is always checked in
// the caller's side.)
MOZ_ASSERT(offset <= (size_t)size());
return typedMem(nogc) + offset;
}
inline MOZ_MUST_USE bool opaque() const;
// Creates a new typed object whose memory is freshly allocated and
// initialized with zeroes (or, in the case of references, an appropriate
// default value).
static TypedObject* createZeroed(JSContext* cx, HandleTypeDescr typeObj,
gc::InitialHeap heap = gc::DefaultHeap);
// User-accessible constructor (`new TypeDescriptor(...)`). Note that the
// callee here is the type descriptor.
static MOZ_MUST_USE bool construct(JSContext* cx, unsigned argc, Value* vp);
Shape** addressOfShapeFromGC() {
return shape_.unsafeUnbarrieredForTracing();
}
};
using HandleTypedObject = Handle<TypedObject*>;
class OutlineTypedObject : public TypedObject {
// The object which owns the data this object points to. Because this
// pointer is managed in tandem with |data|, this is not a GCPtr and
// barriers are managed directly.
JSObject* owner_;
// Data pointer to some offset in the owner's contents.
uint8_t* data_;
void setOwnerAndData(JSObject* owner, uint8_t* data);
void setData(uint8_t* data) { data_ = data; }
public:
// JIT accessors.
static size_t offsetOfData() { return offsetof(OutlineTypedObject, data_); }
static size_t offsetOfOwner() { return offsetof(OutlineTypedObject, owner_); }
JSObject& owner() const {
MOZ_ASSERT(owner_);
return *owner_;
}
uint8_t* outOfLineTypedMem() const { return data_; }
private:
// Helper for createUnattached()
static OutlineTypedObject* createUnattachedWithClass(
JSContext* cx, const JSClass* clasp, HandleTypeDescr type,
gc::InitialHeap heap = gc::DefaultHeap);
// Creates an unattached typed object or handle (depending on the
// type parameter T). Note that it is only legal for unattached
// handles to escape to the end user; for non-handles, the caller
// should always invoke one of the `attach()` methods below.
//
// Arguments:
// - type: type object for resulting object
static OutlineTypedObject* createUnattached(
JSContext* cx, HandleTypeDescr type,
gc::InitialHeap heap = gc::DefaultHeap);
public:
static OutlineTypedObject* createZeroed(JSContext* cx, HandleTypeDescr descr,
gc::InitialHeap heap);
// Creates a typedObj that aliases the memory pointed at by `owner`
// at the given offset. The typedObj will be a handle iff type is a
// handle and a typed object otherwise.
static OutlineTypedObject* createDerived(JSContext* cx, HandleTypeDescr type,
Handle<TypedObject*> typedContents,
uint32_t offset);
static OutlineTypedObject* createOpaque(JSContext* cx, HandleTypeDescr descr,
Handle<TypedObject*> target,
uint32_t offset);
private:
// Use this method when `buffer` is the owner of the memory.
void attach(ArrayBufferObject& buffer, uint32_t offset);
// Otherwise, use this to attach to memory referenced by another typedObj.
void attach(JSContext* cx, TypedObject& typedObj, uint32_t offset);
public:
static void obj_trace(JSTracer* trace, JSObject* object);
};
// Class for a transparent typed object whose owner is an array buffer.
class OutlineTransparentTypedObject : public OutlineTypedObject {
public:
static const JSClass class_;
};
// Class for an opaque typed object whose owner may be either an array buffer
// or an opaque inlined typed object.
class OutlineOpaqueTypedObject : public OutlineTypedObject {
public:
static const JSClass class_;
};
// Class for a typed object whose data is allocated inline.
class InlineTypedObject : public TypedObject {
friend class TypedObject;
// Start of the inline data, which immediately follows the shape and type.
uint8_t data_[1];
public:
static const size_t MaxInlineBytes =
JSObject::MAX_BYTE_SIZE - sizeof(TypedObject);
protected:
uint8_t* inlineTypedMem() const { return (uint8_t*)&data_; }
public:
static inline gc::AllocKind allocKindForTypeDescriptor(TypeDescr* descr);
static bool canAccommodateSize(size_t size) { return size <= MaxInlineBytes; }
static bool canAccommodateType(TypeDescr* type) {
return type->size() <= MaxInlineBytes;
}
uint8_t* inlineTypedMem(const JS::AutoRequireNoGC&) const {
return inlineTypedMem();
}
uint8_t* inlineTypedMemForGC() const { return inlineTypedMem(); }
static void obj_trace(JSTracer* trace, JSObject* object);
static size_t obj_moved(JSObject* dst, JSObject* src);
static size_t offsetOfDataStart() {
return offsetof(InlineTypedObject, data_);
}
static InlineTypedObject* create(JSContext* cx, HandleTypeDescr descr,
gc::InitialHeap heap = gc::DefaultHeap);
static InlineTypedObject* createCopy(
JSContext* cx, Handle<InlineTypedObject*> templateObject,
gc::InitialHeap heap);
};
// Class for a transparent typed object with inline data, which may have a
// lazily allocated array buffer.
class InlineTransparentTypedObject : public InlineTypedObject {
public:
static const JSClass class_;
uint8_t* inlineTypedMem() const {
return InlineTypedObject::inlineTypedMem();
}
};
// Class for an opaque typed object with inline data and no array buffer.
class InlineOpaqueTypedObject : public InlineTypedObject {
public:
static const JSClass class_;
};
/*
* Usage: NewOpaqueTypedObject(typeObj, newDatum, newOffset)
*
* Constructs a new, unattached instance of `Handle`, and then moves the new
* instance to point at the memory referenced by `newDatum` with the offset
* `newOffset`.
*/
MOZ_MUST_USE bool NewOpaqueTypedObject(JSContext* cx, unsigned argc, Value* vp);
/*
* Usage: NewDerivedTypedObject(typeObj, owner, offset)
*
* Constructs a new, unattached instance of `Handle`.
*/
MOZ_MUST_USE bool NewDerivedTypedObject(JSContext* cx, unsigned argc,
Value* vp);
/*
* Usage: ObjectIsTypeDescr(obj)
*
* True if `obj` is a type object.
*/
MOZ_MUST_USE bool ObjectIsTypeDescr(JSContext* cx, unsigned argc, Value* vp);
/*
* Usage: ObjectIsTypedObject(obj)
*
* True if `obj` is a transparent or opaque typed object.
*/
MOZ_MUST_USE bool ObjectIsTypedObject(JSContext* cx, unsigned argc, Value* vp);
// Predicates on type descriptor objects. In all cases, 'obj' must be a type
// descriptor.
MOZ_MUST_USE bool TypeDescrIsSimpleType(JSContext*, unsigned argc, Value* vp);
MOZ_MUST_USE bool TypeDescrIsArrayType(JSContext*, unsigned argc, Value* vp);
/*
* Usage: TypedObjectTypeDescr(obj)
*
* Given a TypedObject `obj`, returns the object's type descriptor.
*/
MOZ_MUST_USE bool TypedObjectTypeDescr(JSContext* cx, unsigned argc, Value* vp);
/*
* Usage: ClampToUint8(v)
*
* Same as the C function ClampDoubleToUint8. `v` must be a number.
*/
MOZ_MUST_USE bool ClampToUint8(JSContext* cx, unsigned argc, Value* vp);
/*
* Usage: GetTypedObjectModule()
*
* Returns the global "typed object" module, which provides access
* to the various builtin type descriptors. These are currently
* exported as immutable properties so it is safe for self-hosted code
* to access them; eventually this should be linked into the module
* system.
*/
MOZ_MUST_USE bool GetTypedObjectModule(JSContext* cx, unsigned argc, Value* vp);
/*
* Usage: IsBoxedWasmAnyRef(Object) -> bool
*
* Return true iff object is an instance of the Wasm-internal type WasmValueBox.
*/
MOZ_MUST_USE bool IsBoxedWasmAnyRef(JSContext* cx, unsigned argc, Value* vp);
/*
* Usage: IsBoxableWasmAnyRef(Value) -> bool
*
* Return true iff the value must be boxed into a WasmValueBox in order to be
* stored into an anyref field. Values for which false is returned may be
* passed as they are to Store_WasmAnyRef and may therefore appear as results
* from Load_WasmAnyRef.
*/
MOZ_MUST_USE bool IsBoxableWasmAnyRef(JSContext* cx, unsigned argc, Value* vp);
/*
* Usage: BoxWasmAnyRef(Value) -> Object
*
* Return a new WasmValueBox that holds `value`. The value can be any value at
* all.
*/
MOZ_MUST_USE bool BoxWasmAnyRef(JSContext* cx, unsigned argc, Value* vp);
/*
* Usage: UnboxBoxedWasmAnyRef(Object) -> Value
*
* The object must be a value for which IsBoxedWasmAnyRef returns true.
* Return the value stored in the box.
*/
MOZ_MUST_USE bool UnboxBoxedWasmAnyRef(JSContext* cx, unsigned argc, Value* vp);
/*
* Usage: Store_int8(targetDatum, targetOffset, value)
* ...
* Store_uint8(targetDatum, targetOffset, value)
* ...
* Store_float32(targetDatum, targetOffset, value)
* Store_float64(targetDatum, targetOffset, value)
*
* Intrinsic function. Stores `value` into the memory referenced by
* `targetDatum` at the offset `targetOffset`.
*
* Assumes (and asserts) that:
* - `targetDatum` is attached
* - `targetOffset` is a valid offset within the bounds of `targetDatum`
* - `value` is a number
*/
#define JS_STORE_SCALAR_CLASS_DEFN(_constant, T, _name) \
class StoreScalar##T { \
public: \
static MOZ_MUST_USE bool Func(JSContext* cx, unsigned argc, Value* vp); \
static const JSJitInfo JitInfo; \
};
/*
* Usage: Store_Any(targetDatum, targetOffset, fieldName, value)
* Store_Object(targetDatum, targetOffset, fieldName, value)
* Store_string(targetDatum, targetOffset, fieldName, value)
*
* Intrinsic function. Stores `value` into the memory referenced by
* `targetDatum` at the offset `targetOffset`.
*
* Assumes (and asserts) that:
* - `targetDatum` is attached
* - `targetOffset` is a valid offset within the bounds of `targetDatum`
* - `value` is an object or null (`Store_Object`) or string (`Store_string`).
*/
#define JS_STORE_REFERENCE_CLASS_DEFN(_constant, T, _name) \
class StoreReference##_name { \
private: \
static MOZ_MUST_USE bool store(JSContext* cx, T* heap, const Value& v, \
TypedObject* obj, jsid id); \
\
public: \
static MOZ_MUST_USE bool Func(JSContext* cx, unsigned argc, Value* vp); \
static const JSJitInfo JitInfo; \
};
/*
* Usage: LoadScalar(targetDatum, targetOffset, value)
*
* Intrinsic function. Loads value (which must be an int32 or uint32)
* by `scalarTypeRepr` (which must be a type repr obj) and loads the
* value at the memory for `targetDatum` at offset `targetOffset`.
* `targetDatum` must be attached.
*/
#define JS_LOAD_SCALAR_CLASS_DEFN(_constant, T, _name) \
class LoadScalar##T { \
public: \
static MOZ_MUST_USE bool Func(JSContext* cx, unsigned argc, Value* vp); \
static const JSJitInfo JitInfo; \
};
/*
* Usage: LoadReference(targetDatum, targetOffset, value)
*
* Intrinsic function. Stores value (which must be an int32 or uint32)
* by `scalarTypeRepr` (which must be a type repr obj) and stores the
* value at the memory for `targetDatum` at offset `targetOffset`.
* `targetDatum` must be attached.
*/
#define JS_LOAD_REFERENCE_CLASS_DEFN(_constant, T, _name) \
class LoadReference##_name { \
private: \
static void load(T* heap, MutableHandleValue v); \
\
public: \
static MOZ_MUST_USE bool Func(JSContext* cx, unsigned argc, Value* vp); \
static const JSJitInfo JitInfo; \
};
// I was using templates for this stuff instead of macros, but ran
// into problems with the Unagi compiler.
JS_FOR_EACH_UNIQUE_SCALAR_NUMBER_TYPE_REPR_CTYPE(JS_STORE_SCALAR_CLASS_DEFN)
JS_FOR_EACH_UNIQUE_SCALAR_NUMBER_TYPE_REPR_CTYPE(JS_LOAD_SCALAR_CLASS_DEFN)
JS_FOR_EACH_SCALAR_BIGINT_TYPE_REPR(JS_STORE_SCALAR_CLASS_DEFN)
JS_FOR_EACH_SCALAR_BIGINT_TYPE_REPR(JS_LOAD_SCALAR_CLASS_DEFN)
JS_FOR_EACH_REFERENCE_TYPE_REPR(JS_STORE_REFERENCE_CLASS_DEFN)
JS_FOR_EACH_REFERENCE_TYPE_REPR(JS_LOAD_REFERENCE_CLASS_DEFN)
inline bool IsTypedObjectClass(const JSClass* class_) {
return class_ == &OutlineTransparentTypedObject::class_ ||
class_ == &InlineTransparentTypedObject::class_ ||
class_ == &OutlineOpaqueTypedObject::class_ ||
class_ == &InlineOpaqueTypedObject::class_;
}
inline bool IsOpaqueTypedObjectClass(const JSClass* class_) {
return class_ == &OutlineOpaqueTypedObject::class_ ||
class_ == &InlineOpaqueTypedObject::class_;
}
inline bool IsOutlineTypedObjectClass(const JSClass* class_) {
return class_ == &OutlineOpaqueTypedObject::class_ ||
class_ == &OutlineTransparentTypedObject::class_;
}
inline bool IsInlineTypedObjectClass(const JSClass* class_) {
return class_ == &InlineOpaqueTypedObject::class_ ||
class_ == &InlineTransparentTypedObject::class_;
}
inline const JSClass* GetOutlineTypedObjectClass(bool opaque) {
return opaque ? &OutlineOpaqueTypedObject::class_
: &OutlineTransparentTypedObject::class_;
}
inline bool IsSimpleTypeDescrClass(const JSClass* clasp) {
return clasp == &ScalarTypeDescr::class_ ||
clasp == &ReferenceTypeDescr::class_;
}
inline bool IsComplexTypeDescrClass(const JSClass* clasp) {
return clasp == &StructTypeDescr::class_ || clasp == &ArrayTypeDescr::class_;
}
inline bool IsTypeDescrClass(const JSClass* clasp) {
return IsSimpleTypeDescrClass(clasp) || IsComplexTypeDescrClass(clasp);
}
inline bool TypedObject::opaque() const {
return IsOpaqueTypedObjectClass(getClass());
}
} // namespace js
template <>
inline bool JSObject::is<js::SimpleTypeDescr>() const {
return js::IsSimpleTypeDescrClass(getClass());
}
template <>
inline bool JSObject::is<js::ComplexTypeDescr>() const {
return js::IsComplexTypeDescrClass(getClass());
}
template <>
inline bool JSObject::is<js::TypeDescr>() const {
return js::IsTypeDescrClass(getClass());
}
template <>
inline bool JSObject::is<js::TypedObject>() const {
return js::IsTypedObjectClass(getClass());
}
template <>
inline bool JSObject::is<js::OutlineTypedObject>() const {
return getClass() == &js::OutlineTransparentTypedObject::class_ ||
getClass() == &js::OutlineOpaqueTypedObject::class_;
}
template <>
inline bool JSObject::is<js::InlineTypedObject>() const {
return getClass() == &js::InlineTransparentTypedObject::class_ ||
getClass() == &js::InlineOpaqueTypedObject::class_;
}
#endif /* builtin_TypedObject_h */