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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sts=4 et sw=4 tw=99:
* 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/. */
/* JavaScript API. */
#ifndef jsapi_h
#define jsapi_h
#include "mozilla/AlreadyAddRefed.h"
#include "mozilla/FloatingPoint.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/Range.h"
#include "mozilla/RangedPtr.h"
#include "mozilla/RefPtr.h"
#include "mozilla/Variant.h"
#include <iterator>
#include <stdarg.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include "jspubtd.h"
#include "js/AllocPolicy.h"
#include "js/CallArgs.h"
#include "js/CharacterEncoding.h"
#include "js/Class.h"
#include "js/GCVector.h"
#include "js/HashTable.h"
#include "js/Id.h"
#include "js/Principals.h"
#include "js/Realm.h"
#include "js/RefCounted.h"
#include "js/RootingAPI.h"
#include "js/Stream.h"
#include "js/TracingAPI.h"
#include "js/UniquePtr.h"
#include "js/Utility.h"
#include "js/Value.h"
#include "js/Vector.h"
/************************************************************************/
namespace JS {
class TwoByteChars;
#ifdef JS_DEBUG
class JS_PUBLIC_API(AutoCheckRequestDepth)
{
JSContext* cx;
public:
explicit AutoCheckRequestDepth(JSContext* cx);
~AutoCheckRequestDepth();
};
# define CHECK_REQUEST(cx) \
JS::AutoCheckRequestDepth _autoCheckRequestDepth(cx)
#else
# define CHECK_REQUEST(cx) \
((void) 0)
#endif /* JS_DEBUG */
/** AutoValueArray roots an internal fixed-size array of Values. */
template <size_t N>
class MOZ_RAII AutoValueArray : public AutoGCRooter
{
const size_t length_;
Value elements_[N];
public:
explicit AutoValueArray(JSContext* cx
MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
: AutoGCRooter(cx, AutoGCRooter::Tag::ValueArray), length_(N)
{
/* Always initialize in case we GC before assignment. */
mozilla::PodArrayZero(elements_);
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
}
unsigned length() const { return length_; }
const Value* begin() const { return elements_; }
Value* begin() { return elements_; }
HandleValue operator[](unsigned i) const {
MOZ_ASSERT(i < N);
return HandleValue::fromMarkedLocation(&elements_[i]);
}
MutableHandleValue operator[](unsigned i) {
MOZ_ASSERT(i < N);
return MutableHandleValue::fromMarkedLocation(&elements_[i]);
}
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};
using ValueVector = JS::GCVector<JS::Value>;
using IdVector = JS::GCVector<jsid>;
using ScriptVector = JS::GCVector<JSScript*>;
using StringVector = JS::GCVector<JSString*>;
/**
* Custom rooting behavior for internal and external clients.
*/
class MOZ_RAII JS_PUBLIC_API(CustomAutoRooter) : private AutoGCRooter
{
public:
template <typename CX>
explicit CustomAutoRooter(const CX& cx MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
: AutoGCRooter(cx, AutoGCRooter::Tag::Custom)
{
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
}
friend void AutoGCRooter::trace(JSTracer* trc);
protected:
virtual ~CustomAutoRooter() {}
/** Supplied by derived class to trace roots. */
virtual void trace(JSTracer* trc) = 0;
private:
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};
/** A handle to an array of rooted values. */
class HandleValueArray
{
const size_t length_;
const Value * const elements_;
HandleValueArray(size_t len, const Value* elements) : length_(len), elements_(elements) {}
public:
explicit HandleValueArray(HandleValue value) : length_(1), elements_(value.address()) {}
MOZ_IMPLICIT HandleValueArray(const AutoValueVector& values)
: length_(values.length()), elements_(values.begin()) {}
template <size_t N>
MOZ_IMPLICIT HandleValueArray(const AutoValueArray<N>& values) : length_(N), elements_(values.begin()) {}
/** CallArgs must already be rooted somewhere up the stack. */
MOZ_IMPLICIT HandleValueArray(const JS::CallArgs& args) : length_(args.length()), elements_(args.array()) {}
/** Use with care! Only call this if the data is guaranteed to be marked. */
static HandleValueArray fromMarkedLocation(size_t len, const Value* elements) {
return HandleValueArray(len, elements);
}
static HandleValueArray subarray(const HandleValueArray& values, size_t startIndex, size_t len) {
MOZ_ASSERT(startIndex + len <= values.length());
return HandleValueArray(len, values.begin() + startIndex);
}
static HandleValueArray empty() {
return HandleValueArray(0, nullptr);
}
size_t length() const { return length_; }
const Value* begin() const { return elements_; }
HandleValue operator[](size_t i) const {
MOZ_ASSERT(i < length_);
return HandleValue::fromMarkedLocation(&elements_[i]);
}
};
} /* namespace JS */
/************************************************************************/
struct JSFreeOp {
protected:
JSRuntime* runtime_;
explicit JSFreeOp(JSRuntime* rt)
: runtime_(rt) { }
public:
JSRuntime* runtime() const {
MOZ_ASSERT(runtime_);
return runtime_;
}
};
/* Callbacks and their arguments. */
/************************************************************************/
typedef bool
(* JSInterruptCallback)(JSContext* cx);
typedef JSObject*
(* JSGetIncumbentGlobalCallback)(JSContext* cx);
typedef bool
(* JSEnqueuePromiseJobCallback)(JSContext* cx, JS::HandleObject job,
JS::HandleObject allocationSite, JS::HandleObject incumbentGlobal,
void* data);
namespace JS {
enum class PromiseRejectionHandlingState {
Unhandled,
Handled
};
} /* namespace JS */
typedef void
(* JSPromiseRejectionTrackerCallback)(JSContext* cx, JS::HandleObject promise,
JS::PromiseRejectionHandlingState state,
void* data);
/**
* Possible exception types. These types are part of a JSErrorFormatString
* structure. They define which error to throw in case of a runtime error.
*
* JSEXN_WARN is used for warnings in js.msg files (for instance because we
* don't want to prepend 'Error:' to warning messages). This value can go away
* if we ever decide to use an entirely separate mechanism for warnings.
*/
typedef enum JSExnType {
JSEXN_ERR,
JSEXN_FIRST = JSEXN_ERR,
JSEXN_INTERNALERR,
JSEXN_EVALERR,
JSEXN_RANGEERR,
JSEXN_REFERENCEERR,
JSEXN_SYNTAXERR,
JSEXN_TYPEERR,
JSEXN_URIERR,
JSEXN_DEBUGGEEWOULDRUN,
JSEXN_WASMCOMPILEERROR,
JSEXN_WASMLINKERROR,
JSEXN_WASMRUNTIMEERROR,
JSEXN_ERROR_LIMIT,
JSEXN_WARN = JSEXN_ERROR_LIMIT,
JSEXN_NOTE,
JSEXN_LIMIT
} JSExnType;
struct JSErrorFormatString {
/** The error message name in ASCII. */
const char* name;
/** The error format string in ASCII. */
const char* format;
/** The number of arguments to expand in the formatted error message. */
uint16_t argCount;
/** One of the JSExnType constants above. */
int16_t exnType;
};
typedef const JSErrorFormatString*
(* JSErrorCallback)(void* userRef, const unsigned errorNumber);
typedef bool
(* JSLocaleToUpperCase)(JSContext* cx, JS::HandleString src, JS::MutableHandleValue rval);
typedef bool
(* JSLocaleToLowerCase)(JSContext* cx, JS::HandleString src, JS::MutableHandleValue rval);
typedef bool
(* JSLocaleCompare)(JSContext* cx, JS::HandleString src1, JS::HandleString src2,
JS::MutableHandleValue rval);
typedef bool
(* JSLocaleToUnicode)(JSContext* cx, const char* src, JS::MutableHandleValue rval);
/**
* Callback used to ask the embedding for the cross compartment wrapper handler
* that implements the desired prolicy for this kind of object in the
* destination compartment. |obj| is the object to be wrapped. If |existing| is
* non-nullptr, it will point to an existing wrapper object that should be
* re-used if possible. |existing| is guaranteed to be a cross-compartment
* wrapper with a lazily-defined prototype and the correct global. It is
* guaranteed not to wrap a function.
*/
typedef JSObject*
(* JSWrapObjectCallback)(JSContext* cx, JS::HandleObject existing, JS::HandleObject obj);
/**
* Callback used by the wrap hook to ask the embedding to prepare an object
* for wrapping in a context. This might include unwrapping other wrappers
* or even finding a more suitable object for the new compartment.
*/
typedef void
(* JSPreWrapCallback)(JSContext* cx, JS::HandleObject scope, JS::HandleObject obj,
JS::HandleObject objectPassedToWrap,
JS::MutableHandleObject retObj);
struct JSWrapObjectCallbacks
{
JSWrapObjectCallback wrap;
JSPreWrapCallback preWrap;
};
typedef void
(* JSDestroyCompartmentCallback)(JSFreeOp* fop, JS::Compartment* compartment);
typedef size_t
(* JSSizeOfIncludingThisCompartmentCallback)(mozilla::MallocSizeOf mallocSizeOf,
JS::Compartment* compartment);
/**
* Callback used by memory reporting to ask the embedder how much memory an
* external string is keeping alive. The embedder is expected to return a value
* that corresponds to the size of the allocation that will be released by the
* JSStringFinalizer passed to JS_NewExternalString for this string.
*
* Implementations of this callback MUST NOT do anything that can cause GC.
*/
using JSExternalStringSizeofCallback =
size_t (*)(JSString* str, mozilla::MallocSizeOf mallocSizeOf);
/**
* Callback used to intercept JavaScript errors.
*/
struct JSErrorInterceptor {
/**
* This method is called whenever an error has been raised from JS code.
*
* This method MUST be infallible.
*/
virtual void interceptError(JSContext* cx, const JS::Value& error) = 0;
};
/************************************************************************/
static MOZ_ALWAYS_INLINE JS::Value
JS_NumberValue(double d)
{
int32_t i;
d = JS::CanonicalizeNaN(d);
if (mozilla::NumberIsInt32(d, &i))
return JS::Int32Value(i);
return JS::DoubleValue(d);
}
/************************************************************************/
JS_PUBLIC_API(bool)
JS_StringHasBeenPinned(JSContext* cx, JSString* str);
namespace JS {
/**
* Container class for passing in script source buffers to the JS engine. This
* not only groups the buffer and length values, it also provides a way to
* optionally pass ownership of the buffer to the JS engine without copying.
* Rules for use:
*
* 1) The data array must be allocated with js_malloc() or js_realloc() if
* ownership is being granted to the SourceBufferHolder.
* 2) If ownership is not given to the SourceBufferHolder, then the memory
* must be kept alive until the JS compilation is complete.
* 3) Any code calling SourceBufferHolder::take() must guarantee to keep the
* memory alive until JS compilation completes. Normally only the JS
* engine should be calling take().
*
* Example use:
*
* size_t length = 512;
* char16_t* chars = js_pod_malloc<char16_t>(length);
* JS::SourceBufferHolder srcBuf(chars, length, JS::SourceBufferHolder::GiveOwnership);
* JS::Compile(cx, options, srcBuf);
*/
class SourceBufferHolder final
{
public:
enum Ownership {
NoOwnership,
GiveOwnership
};
SourceBufferHolder(const char16_t* data, size_t dataLength, Ownership ownership)
: data_(data),
length_(dataLength),
ownsChars_(ownership == GiveOwnership)
{
fixEmptyBuffer();
}
SourceBufferHolder(UniqueTwoByteChars&& data, size_t dataLength)
: data_(data.release()),
length_(dataLength),
ownsChars_(true)
{
fixEmptyBuffer();
}
SourceBufferHolder(SourceBufferHolder&& other)
: data_(other.data_),
length_(other.length_),
ownsChars_(other.ownsChars_)
{
other.data_ = nullptr;
other.length_ = 0;
other.ownsChars_ = false;
}
~SourceBufferHolder() {
if (ownsChars_)
js_free(const_cast<char16_t*>(data_));
}
// Access the underlying source buffer without affecting ownership.
const char16_t* get() const { return data_; }
// Length of the source buffer in char16_t code units (not bytes)
size_t length() const { return length_; }
// Returns true if the SourceBufferHolder owns the buffer and will free
// it upon destruction. If true, it is legal to call take().
bool ownsChars() const { return ownsChars_; }
// Retrieve and take ownership of the underlying data buffer. The caller
// is now responsible for calling js_free() on the returned value, *but only
// after JS script compilation has completed*.
//
// After the buffer has been taken the SourceBufferHolder functions as if
// it had been constructed on an unowned buffer; get() and length() still
// work. In order for this to be safe the taken buffer must be kept alive
// until after JS script compilation completes as noted above.
//
// Note, it's the caller's responsibility to check ownsChars() before taking
// the buffer. Taking and then free'ing an unowned buffer will have dire
// consequences.
char16_t* take() {
MOZ_ASSERT(ownsChars_);
ownsChars_ = false;
return const_cast<char16_t*>(data_);
}
private:
SourceBufferHolder(SourceBufferHolder&) = delete;
SourceBufferHolder& operator=(SourceBufferHolder&) = delete;
void fixEmptyBuffer() {
// Ensure that null buffers properly return an unowned, empty,
// null-terminated string.
static const char16_t NullChar_ = 0;
if (!get()) {
data_ = &NullChar_;
length_ = 0;
ownsChars_ = false;
}
}
const char16_t* data_;
size_t length_;
bool ownsChars_;
};
struct TranscodeSource;
} /* namespace JS */
/************************************************************************/
/* Property attributes, set in JSPropertySpec and passed to API functions.
*
* NB: The data structure in which some of these values are stored only uses
* a uint8_t to store the relevant information. Proceed with caution if
* trying to reorder or change the the first byte worth of flags.
*/
/* property is visible to for/in loop */
static const uint8_t JSPROP_ENUMERATE = 0x01;
/* not settable: assignment is no-op. This flag is only valid when neither
JSPROP_GETTER nor JSPROP_SETTER is set. */
static const uint8_t JSPROP_READONLY = 0x02;
/* property cannot be deleted */
static const uint8_t JSPROP_PERMANENT = 0x04;
/* (0x08 is unused) */
/* property holds getter function */
static const uint8_t JSPROP_GETTER = 0x10;
/* property holds setter function */
static const uint8_t JSPROP_SETTER = 0x20;
/* internal JS engine use only */
static const uint8_t JSPROP_INTERNAL_USE_BIT = 0x80;
/* native that can be called as a ctor */
static const unsigned JSFUN_CONSTRUCTOR = 0x400;
/* | of all the JSFUN_* flags */
static const unsigned JSFUN_FLAGS_MASK = 0x400;
/*
* Resolve hooks and enumerate hooks must pass this flag when calling
* JS_Define* APIs to reify lazily-defined properties.
*
* JSPROP_RESOLVING is used only with property-defining APIs. It tells the
* engine to skip the resolve hook when performing the lookup at the beginning
* of property definition. This keeps the resolve hook from accidentally
* triggering itself: unchecked recursion.
*
* For enumerate hooks, triggering the resolve hook would be merely silly, not
* fatal, except in some cases involving non-configurable properties.
*/
static const unsigned JSPROP_RESOLVING = 0x2000;
/* ignore the value in JSPROP_ENUMERATE. This flag only valid when defining
over an existing property. */
static const unsigned JSPROP_IGNORE_ENUMERATE = 0x4000;
/* ignore the value in JSPROP_READONLY. This flag only valid when defining over
an existing property. */
static const unsigned JSPROP_IGNORE_READONLY = 0x8000;
/* ignore the value in JSPROP_PERMANENT. This flag only valid when defining
over an existing property. */
static const unsigned JSPROP_IGNORE_PERMANENT = 0x10000;
/* ignore the Value in the descriptor. Nothing was specified when passed to
Object.defineProperty from script. */
static const unsigned JSPROP_IGNORE_VALUE = 0x20000;
/** Microseconds since the epoch, midnight, January 1, 1970 UTC. */
extern JS_PUBLIC_API(int64_t)
JS_Now(void);
/** Don't want to export data, so provide accessors for non-inline Values. */
extern JS_PUBLIC_API(JS::Value)
JS_GetNaNValue(JSContext* cx);
extern JS_PUBLIC_API(JS::Value)
JS_GetNegativeInfinityValue(JSContext* cx);
extern JS_PUBLIC_API(JS::Value)
JS_GetPositiveInfinityValue(JSContext* cx);
extern JS_PUBLIC_API(JS::Value)
JS_GetEmptyStringValue(JSContext* cx);
extern JS_PUBLIC_API(JSString*)
JS_GetEmptyString(JSContext* cx);
extern JS_PUBLIC_API(bool)
JS_ValueToObject(JSContext* cx, JS::HandleValue v, JS::MutableHandleObject objp);
extern JS_PUBLIC_API(JSFunction*)
JS_ValueToFunction(JSContext* cx, JS::HandleValue v);
extern JS_PUBLIC_API(JSFunction*)
JS_ValueToConstructor(JSContext* cx, JS::HandleValue v);
extern JS_PUBLIC_API(JSString*)
JS_ValueToSource(JSContext* cx, JS::Handle<JS::Value> v);
extern JS_PUBLIC_API(bool)
JS_DoubleIsInt32(double d, int32_t* ip);
extern JS_PUBLIC_API(JSType)
JS_TypeOfValue(JSContext* cx, JS::Handle<JS::Value> v);
namespace JS {
extern JS_PUBLIC_API(const char*)
InformalValueTypeName(const JS::Value& v);
} /* namespace JS */
extern JS_PUBLIC_API(bool)
JS_StrictlyEqual(JSContext* cx, JS::Handle<JS::Value> v1, JS::Handle<JS::Value> v2, bool* equal);
extern JS_PUBLIC_API(bool)
JS_LooselyEqual(JSContext* cx, JS::Handle<JS::Value> v1, JS::Handle<JS::Value> v2, bool* equal);
extern JS_PUBLIC_API(bool)
JS_SameValue(JSContext* cx, JS::Handle<JS::Value> v1, JS::Handle<JS::Value> v2, bool* same);
/** True iff fun is the global eval function. */
extern JS_PUBLIC_API(bool)
JS_IsBuiltinEvalFunction(JSFunction* fun);
/** True iff fun is the Function constructor. */
extern JS_PUBLIC_API(bool)
JS_IsBuiltinFunctionConstructor(JSFunction* fun);
/************************************************************************/
/*
* Locking, contexts, and memory allocation.
*
* It is important that SpiderMonkey be initialized, and the first context
* be created, in a single-threaded fashion. Otherwise the behavior of the
* library is undefined.
*/
// Create a new runtime, with a single cooperative context for this thread.
// On success, the new context will be the active context for the runtime.
extern JS_PUBLIC_API(JSContext*)
JS_NewContext(uint32_t maxbytes,
uint32_t maxNurseryBytes = JS::DefaultNurseryBytes,
JSRuntime* parentRuntime = nullptr);
// The methods below for controlling the active context in a cooperatively
// multithreaded runtime are not threadsafe, and the caller must ensure they
// are called serially if there is a chance for contention between threads.
// Called from the active context for a runtime, yield execution so that
// this context is no longer active and can no longer use the API.
extern JS_PUBLIC_API(void)
JS_YieldCooperativeContext(JSContext* cx);
// Called from a context whose runtime has no active context, this thread
// becomes the active context for that runtime and may use the API.
extern JS_PUBLIC_API(void)
JS_ResumeCooperativeContext(JSContext* cx);
// Create a new context on this thread for cooperative multithreading in the
// same runtime as siblingContext. Called on a runtime (as indicated by
// siblingContet) which has no active context, on success the new context will
// become the runtime's active context.
extern JS_PUBLIC_API(JSContext*)
JS_NewCooperativeContext(JSContext* siblingContext);
// Destroy a context allocated with JS_NewContext or JS_NewCooperativeContext.
// The context must be the current active context in the runtime, and after
// this call the runtime will have no active context.
extern JS_PUBLIC_API(void)
JS_DestroyContext(JSContext* cx);
JS_PUBLIC_API(void*)
JS_GetContextPrivate(JSContext* cx);
JS_PUBLIC_API(void)
JS_SetContextPrivate(JSContext* cx, void* data);
extern JS_PUBLIC_API(JSRuntime*)
JS_GetParentRuntime(JSContext* cx);
extern JS_PUBLIC_API(JSRuntime*)
JS_GetRuntime(JSContext* cx);
extern JS_PUBLIC_API(void)
JS_BeginRequest(JSContext* cx);
extern JS_PUBLIC_API(void)
JS_EndRequest(JSContext* cx);
extern JS_PUBLIC_API(void)
JS_SetFutexCanWait(JSContext* cx);
namespace js {
void
AssertHeapIsIdle();
} /* namespace js */
class MOZ_RAII JSAutoRequest
{
public:
explicit JSAutoRequest(JSContext* cx
MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
: mContext(cx)
{
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
JS_BeginRequest(mContext);
}
~JSAutoRequest() {
JS_EndRequest(mContext);
}
protected:
JSContext* mContext;
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
#if 0
private:
static void* operator new(size_t) CPP_THROW_NEW { return 0; }
static void operator delete(void*, size_t) { }
#endif
};
namespace JS {
class JS_PUBLIC_API(ContextOptions) {
public:
ContextOptions()
: baseline_(true),
ion_(true),
asmJS_(true),
wasm_(true),
wasmBaseline_(true),
wasmIon_(true),
#ifdef ENABLE_WASM_GC
wasmGc_(false),
#endif
testWasmAwaitTier2_(false),
throwOnAsmJSValidationFailure_(false),
nativeRegExp_(true),
asyncStack_(true),
throwOnDebuggeeWouldRun_(true),
dumpStackOnDebuggeeWouldRun_(false),
werror_(false),
strictMode_(false),
extraWarnings_(false),
streams_(false)
#ifdef FUZZING
, fuzzing_(false)
#endif
{
}
bool baseline() const { return baseline_; }
ContextOptions& setBaseline(bool flag) {
baseline_ = flag;
return *this;
}
ContextOptions& toggleBaseline() {
baseline_ = !baseline_;
return *this;
}
bool ion() const { return ion_; }
ContextOptions& setIon(bool flag) {
ion_ = flag;
return *this;
}
ContextOptions& toggleIon() {
ion_ = !ion_;
return *this;
}
bool asmJS() const { return asmJS_; }
ContextOptions& setAsmJS(bool flag) {
asmJS_ = flag;
return *this;
}
ContextOptions& toggleAsmJS() {
asmJS_ = !asmJS_;
return *this;
}
bool wasm() const { return wasm_; }
ContextOptions& setWasm(bool flag) {
wasm_ = flag;
return *this;
}
ContextOptions& toggleWasm() {
wasm_ = !wasm_;
return *this;
}
bool streams() const { return streams_; }
ContextOptions& setStreams(bool flag) {
streams_ = flag;
return *this;
}
ContextOptions& toggleStreams() {
streams_ = !streams_;
return *this;
}
bool wasmBaseline() const { return wasmBaseline_; }
ContextOptions& setWasmBaseline(bool flag) {
wasmBaseline_ = flag;
return *this;
}
ContextOptions& toggleWasmBaseline() {
wasmBaseline_ = !wasmBaseline_;
return *this;
}
bool wasmIon() const { return wasmIon_; }
ContextOptions& setWasmIon(bool flag) {
wasmIon_ = flag;
return *this;
}
ContextOptions& toggleWasmIon() {
wasmIon_ = !wasmIon_;
return *this;
}
bool testWasmAwaitTier2() const { return testWasmAwaitTier2_; }
ContextOptions& setTestWasmAwaitTier2(bool flag) {
testWasmAwaitTier2_ = flag;
return *this;
}
ContextOptions& toggleTestWasmAwaitTier2() {
testWasmAwaitTier2_ = !testWasmAwaitTier2_;
return *this;
}
#ifdef ENABLE_WASM_GC
bool wasmGc() const { return wasmGc_; }
ContextOptions& setWasmGc(bool flag) {
wasmGc_ = flag;
return *this;
}
#endif
bool throwOnAsmJSValidationFailure() const { return throwOnAsmJSValidationFailure_; }
ContextOptions& setThrowOnAsmJSValidationFailure(bool flag) {
throwOnAsmJSValidationFailure_ = flag;
return *this;
}
ContextOptions& toggleThrowOnAsmJSValidationFailure() {
throwOnAsmJSValidationFailure_ = !throwOnAsmJSValidationFailure_;
return *this;
}
bool nativeRegExp() const { return nativeRegExp_; }
ContextOptions& setNativeRegExp(bool flag) {
nativeRegExp_ = flag;
return *this;
}
bool asyncStack() const { return asyncStack_; }
ContextOptions& setAsyncStack(bool flag) {
asyncStack_ = flag;
return *this;
}
bool throwOnDebuggeeWouldRun() const { return throwOnDebuggeeWouldRun_; }
ContextOptions& setThrowOnDebuggeeWouldRun(bool flag) {
throwOnDebuggeeWouldRun_ = flag;
return *this;
}
bool dumpStackOnDebuggeeWouldRun() const { return dumpStackOnDebuggeeWouldRun_; }
ContextOptions& setDumpStackOnDebuggeeWouldRun(bool flag) {
dumpStackOnDebuggeeWouldRun_ = flag;
return *this;
}
bool werror() const { return werror_; }
ContextOptions& setWerror(bool flag) {
werror_ = flag;
return *this;
}
ContextOptions& toggleWerror() {
werror_ = !werror_;
return *this;
}
bool strictMode() const { return strictMode_; }
ContextOptions& setStrictMode(bool flag) {
strictMode_ = flag;
return *this;
}
ContextOptions& toggleStrictMode() {
strictMode_ = !strictMode_;
return *this;
}
bool extraWarnings() const { return extraWarnings_; }
ContextOptions& setExtraWarnings(bool flag) {
extraWarnings_ = flag;
return *this;
}
ContextOptions& toggleExtraWarnings() {
extraWarnings_ = !extraWarnings_;
return *this;
}
#ifdef FUZZING
bool fuzzing() const { return fuzzing_; }
ContextOptions& setFuzzing(bool flag) {
fuzzing_ = flag;
return *this;
}
#endif
void disableOptionsForSafeMode() {
setBaseline(false);
setIon(false);
setAsmJS(false);
setWasm(false);
setWasmBaseline(false);
setWasmIon(false);
#ifdef ENABLE_WASM_GC
setWasmGc(false);
#endif
setNativeRegExp(false);
}
private:
bool baseline_ : 1;
bool ion_ : 1;
bool asmJS_ : 1;
bool wasm_ : 1;
bool wasmBaseline_ : 1;
bool wasmIon_ : 1;
#ifdef ENABLE_WASM_GC
bool wasmGc_ : 1;
#endif
bool testWasmAwaitTier2_ : 1;
bool throwOnAsmJSValidationFailure_ : 1;
bool nativeRegExp_ : 1;
bool asyncStack_ : 1;
bool throwOnDebuggeeWouldRun_ : 1;
bool dumpStackOnDebuggeeWouldRun_ : 1;
bool werror_ : 1;
bool strictMode_ : 1;
bool extraWarnings_ : 1;
bool streams_: 1;
#ifdef FUZZING
bool fuzzing_ : 1;
#endif
};
JS_PUBLIC_API(ContextOptions&)
ContextOptionsRef(JSContext* cx);
/**
* Initialize the runtime's self-hosted code. Embeddings should call this
* exactly once per runtime/context, before the first JS_NewGlobalObject
* call.
*/
JS_PUBLIC_API(bool)
InitSelfHostedCode(JSContext* cx);
/**
* Asserts (in debug and release builds) that `obj` belongs to the current
* thread's context.
*/
JS_PUBLIC_API(void)
AssertObjectBelongsToCurrentThread(JSObject* obj);
} /* namespace JS */
extern JS_PUBLIC_API(const char*)
JS_GetImplementationVersion(void);
extern JS_PUBLIC_API(void)
JS_SetDestroyCompartmentCallback(JSContext* cx, JSDestroyCompartmentCallback callback);
extern JS_PUBLIC_API(void)
JS_SetSizeOfIncludingThisCompartmentCallback(JSContext* cx,
JSSizeOfIncludingThisCompartmentCallback callback);
extern JS_PUBLIC_API(void)
JS_SetWrapObjectCallbacks(JSContext* cx, const JSWrapObjectCallbacks* callbacks);
extern JS_PUBLIC_API(void)
JS_SetExternalStringSizeofCallback(JSContext* cx, JSExternalStringSizeofCallback callback);
#if defined(NIGHTLY_BUILD)
// Set a callback that will be called whenever an error
// is thrown in this runtime. This is designed as a mechanism
// for logging errors. Note that the VM makes no attempt to sanitize
// the contents of the error (so it may contain private data)
// or to sort out among errors (so it may not be the error you
// are interested in or for the component in which you are
// interested).
//
// If the callback sets a new error, this new error
// will replace the original error.
//
// May be `nullptr`.
extern JS_PUBLIC_API(void)
JS_SetErrorInterceptorCallback(JSRuntime*, JSErrorInterceptor* callback);
extern JS_PUBLIC_API(JSErrorInterceptor*)
JS_GetErrorInterceptorCallback(JSRuntime*);
// Examine a value to determine if it is one of the built-in Error types.
// If so, return the error type.
extern JS_PUBLIC_API(mozilla::Maybe<JSExnType>)
JS_GetErrorType(const JS::Value& val);
#endif // defined(NIGHTLY_BUILD)
extern JS_PUBLIC_API(void)
JS_SetCompartmentPrivate(JS::Compartment* compartment, void* data);
extern JS_PUBLIC_API(void*)
JS_GetCompartmentPrivate(JS::Compartment* compartment);
extern JS_PUBLIC_API(void)
JS_SetZoneUserData(JS::Zone* zone, void* data);
extern JS_PUBLIC_API(void*)
JS_GetZoneUserData(JS::Zone* zone);
extern JS_PUBLIC_API(bool)
JS_WrapObject(JSContext* cx, JS::MutableHandleObject objp);
extern JS_PUBLIC_API(bool)
JS_WrapValue(JSContext* cx, JS::MutableHandleValue vp);
extern JS_PUBLIC_API(JSObject*)
JS_TransplantObject(JSContext* cx, JS::HandleObject origobj, JS::HandleObject target);
extern JS_PUBLIC_API(bool)
JS_RefreshCrossCompartmentWrappers(JSContext* cx, JS::Handle<JSObject*> obj);
/*
* At any time, a JSContext has a current (possibly-nullptr) realm.
* Realms are described in:
*
* developer.mozilla.org/en-US/docs/SpiderMonkey/SpiderMonkey_compartments
*
* The current realm of a context may be changed. The preferred way to do
* this is with JSAutoRealm:
*
* void foo(JSContext* cx, JSObject* obj) {
* // in some realm 'r'
* {
* JSAutoRealm ar(cx, obj); // constructor enters
* // in the realm of 'obj'
* } // destructor leaves
* // back in realm 'r'
* }
*
* For more complicated uses that don't neatly fit in a C++ stack frame, the
* realm can be entered and left using separate function calls:
*
* void foo(JSContext* cx, JSObject* obj) {
* // in 'oldRealm'
* JS::Realm* oldRealm = JS::EnterRealm(cx, obj);
* // in the realm of 'obj'
* JS::LeaveRealm(cx, oldRealm);
* // back in 'oldRealm'
* }
*
* Note: these calls must still execute in a LIFO manner w.r.t all other
* enter/leave calls on the context. Furthermore, only the return value of a
* JS::EnterRealm call may be passed as the 'oldRealm' argument of
* the corresponding JS::LeaveRealm call.
*
* Entering a realm roots the realm and its global object for the lifetime of
* the JSAutoRealm.
*/
// JSAutoRealmAllowCCW is deprecated and will be removed soon, because entering
// the realm of a CCW doesn't make sense when CCWs are shared by all realms in
// the compartment. New code should prefer JSAutoRealm below instead (it asserts
// the object is not a CCW).
class MOZ_RAII JS_PUBLIC_API(JSAutoRealmAllowCCW)
{
JSContext* cx_;
JS::Realm* oldRealm_;
public:
JSAutoRealmAllowCCW(JSContext* cx, JSObject* target MOZ_GUARD_OBJECT_NOTIFIER_PARAM);
JSAutoRealmAllowCCW(JSContext* cx, JSScript* target MOZ_GUARD_OBJECT_NOTIFIER_PARAM);
~JSAutoRealmAllowCCW();
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};
class MOZ_RAII JS_PUBLIC_API(JSAutoRealm) : public JSAutoRealmAllowCCW
{
public:
JSAutoRealm(JSContext* cx, JSObject* target MOZ_GUARD_OBJECT_NOTIFIER_PARAM);
JSAutoRealm(JSContext* cx, JSScript* target MOZ_GUARD_OBJECT_NOTIFIER_PARAM);
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};
class MOZ_RAII JS_PUBLIC_API(JSAutoNullableRealm)
{
JSContext* cx_;
JS::Realm* oldRealm_;
public:
explicit JSAutoNullableRealm(JSContext* cx, JSObject* targetOrNull
MOZ_GUARD_OBJECT_NOTIFIER_PARAM);
~JSAutoNullableRealm();
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};
namespace JS {
/** NB: This API is infallible; a nullptr return value does not indicate error.
*
* Entering a realm roots the realm and its global object until the matching
* JS::LeaveRealm() call.
*/
extern JS_PUBLIC_API(JS::Realm*)
EnterRealm(JSContext* cx, JSObject* target);
extern JS_PUBLIC_API(void)
LeaveRealm(JSContext* cx, JS::Realm* oldRealm);
using IterateRealmCallback = void (*)(JSContext* cx, void* data, Handle<Realm*> realm);
/**
* This function calls |realmCallback| on every realm. Beware that there is no
* guarantee that the realm will survive after the callback returns. Also,
* barriers are disabled via the TraceSession.
*/
extern JS_PUBLIC_API(void)
IterateRealms(JSContext* cx, void* data, IterateRealmCallback realmCallback);
/**
* Like IterateRealms, but only iterates realms in |compartment|.
*/
extern JS_PUBLIC_API(void)
IterateRealmsInCompartment(JSContext* cx, JS::Compartment* compartment, void* data,
IterateRealmCallback realmCallback);
} // namespace JS
typedef void (*JSIterateCompartmentCallback)(JSContext* cx, void* data, JS::Compartment* compartment);
/**
* This function calls |compartmentCallback| on every compartment. Beware that
* there is no guarantee that the compartment will survive after the callback
* returns. Also, barriers are disabled via the TraceSession.
*/
extern JS_PUBLIC_API(void)
JS_IterateCompartments(JSContext* cx, void* data,
JSIterateCompartmentCallback compartmentCallback);
/**
* Mark a jsid after entering a new compartment. Different zones separately
* mark the ids in a runtime, and this must be used any time an id is obtained
* from one compartment and then used in another compartment, unless the two
* compartments are guaranteed to be in the same zone.
*/
extern JS_PUBLIC_API(void)
JS_MarkCrossZoneId(JSContext* cx, jsid id);
/**
* If value stores a jsid (an atomized string or symbol), mark that id as for
* JS_MarkCrossZoneId.
*/
extern JS_PUBLIC_API(void)
JS_MarkCrossZoneIdValue(JSContext* cx, const JS::Value& value);
/**
* Resolve id, which must contain either a string or an int, to a standard
* class name in obj if possible, defining the class's constructor and/or
* prototype and storing true in *resolved. If id does not name a standard
* class or a top-level property induced by initializing a standard class,
* store false in *resolved and just return true. Return false on error,
* as usual for bool result-typed API entry points.
*
* This API can be called directly from a global object class's resolve op,
* to define standard classes lazily. The class should either have an enumerate
* hook that calls JS_EnumerateStandardClasses, or a newEnumerate hook that
* calls JS_NewEnumerateStandardClasses. newEnumerate is preferred because it's
* faster (does not define all standard classes).
*/
extern JS_PUBLIC_API(bool)
JS_ResolveStandardClass(JSContext* cx, JS::HandleObject obj, JS::HandleId id, bool* resolved);
extern JS_PUBLIC_API(bool)
JS_MayResolveStandardClass(const JSAtomState& names, jsid id, JSObject* maybeObj);
extern JS_PUBLIC_API(bool)
JS_EnumerateStandardClasses(JSContext* cx, JS::HandleObject obj);
extern JS_PUBLIC_API(bool)
JS_NewEnumerateStandardClasses(JSContext* cx, JS::HandleObject obj, JS::AutoIdVector& properties,
bool enumerableOnly);
extern JS_PUBLIC_API(bool)
JS_GetClassObject(JSContext* cx, JSProtoKey key, JS::MutableHandle<JSObject*> objp);
extern JS_PUBLIC_API(bool)
JS_GetClassPrototype(JSContext* cx, JSProtoKey key, JS::MutableHandle<JSObject*> objp);
namespace JS {
/*
* Determine if the given object is an instance/prototype/constructor for a standard
* class. If so, return the associated JSProtoKey. If not, return JSProto_Null.
*/
extern JS_PUBLIC_API(JSProtoKey)
IdentifyStandardInstance(JSObject* obj);
extern JS_PUBLIC_API(JSProtoKey)
IdentifyStandardPrototype(JSObject* obj);
extern JS_PUBLIC_API(JSProtoKey)
IdentifyStandardInstanceOrPrototype(JSObject* obj);
extern JS_PUBLIC_API(JSProtoKey)
IdentifyStandardConstructor(JSObject* obj);
extern JS_PUBLIC_API(void)
ProtoKeyToId(JSContext* cx, JSProtoKey key, JS::MutableHandleId idp);
} /* namespace JS */
extern JS_PUBLIC_API(JSProtoKey)
JS_IdToProtoKey(JSContext* cx, JS::HandleId id);
extern JS_PUBLIC_API(bool)
JS_IsGlobalObject(JSObject* obj);
extern JS_PUBLIC_API(JSObject*)
JS_GlobalLexicalEnvironment(JSObject* obj);
extern JS_PUBLIC_API(bool)
JS_HasExtensibleLexicalEnvironment(JSObject* obj);
extern JS_PUBLIC_API(JSObject*)
JS_ExtensibleLexicalEnvironment(JSObject* obj);
namespace JS {
/**
* Get the current realm's global. Returns nullptr if no realm has been
* entered.
*/
extern JS_PUBLIC_API(JSObject*)
CurrentGlobalOrNull(JSContext* cx);
/**
* Get the global object associated with an object's realm. The object must not
* be a cross-compartment wrapper (because CCWs are shared by all realms in the
* compartment).
*/
extern JS_PUBLIC_API(JSObject*)
GetNonCCWObjectGlobal(JSObject* obj);
/**
* Get the global object associated with a script's realm.
*/
extern JS_PUBLIC_API(JSObject*)
GetScriptGlobal(JSScript* script);
} // namespace JS
/**
* Add 'Reflect.parse', a SpiderMonkey extension, to the Reflect object on the
* given global.
*/
extern JS_PUBLIC_API(bool)
JS_InitReflectParse(JSContext* cx, JS::HandleObject global);
/**
* Add various profiling-related functions as properties of the given object.
* Defined in builtin/Profilers.cpp.
*/
extern JS_PUBLIC_API(bool)
JS_DefineProfilingFunctions(JSContext* cx, JS::HandleObject obj);
/* Defined in vm/Debugger.cpp. */
extern JS_PUBLIC_API(bool)
JS_DefineDebuggerObject(JSContext* cx, JS::HandleObject obj);
namespace JS {
/**
* Tell JS engine whether Profile Timeline Recording is enabled or not.
* If Profile Timeline Recording is enabled, data shown there like stack won't
* be optimized out.
* This is global state and not associated with specific runtime or context.
*/
extern JS_PUBLIC_API(void)
SetProfileTimelineRecordingEnabled(bool enabled);
extern JS_PUBLIC_API(bool)
IsProfileTimelineRecordingEnabled();
} // namespace JS
#ifdef JS_HAS_CTYPES
/**
* Initialize the 'ctypes' object on a global variable 'obj'. The 'ctypes'
* object will be sealed.
*/
extern JS_PUBLIC_API(bool)
JS_InitCTypesClass(JSContext* cx, JS::HandleObject global);
/**
* Convert a unicode string 'source' of length 'slen' to the platform native
* charset, returning a null-terminated string allocated with JS_malloc. On
* failure, this function should report an error.
*/
typedef char*
(* JSCTypesUnicodeToNativeFun)(JSContext* cx, const char16_t* source, size_t slen);
/**
* Set of function pointers that ctypes can use for various internal functions.
* See JS_SetCTypesCallbacks below. Providing nullptr for a function is safe,
* and will result in the applicable ctypes functionality not being available.
*/
struct JSCTypesCallbacks {
JSCTypesUnicodeToNativeFun unicodeToNative;
};
/**
* Set the callbacks on the provided 'ctypesObj' object. 'callbacks' should be a
* pointer to static data that exists for the lifetime of 'ctypesObj', but it
* may safely be altered after calling this function and without having
* to call this function again.
*/
extern JS_PUBLIC_API(void)
JS_SetCTypesCallbacks(JSObject* ctypesObj, const JSCTypesCallbacks* callbacks);
#endif
extern JS_PUBLIC_API(void*)
JS_malloc(JSContext* cx, size_t nbytes);
extern JS_PUBLIC_API(void*)
JS_realloc(JSContext* cx, void* p, size_t oldBytes, size_t newBytes);
/**
* A wrapper for js_free(p) that may delay js_free(p) invocation as a
* performance optimization.
* cx may be nullptr.
*/
extern JS_PUBLIC_API(void)
JS_free(JSContext* cx, void* p);
/**
* A wrapper for js_free(p) that may delay js_free(p) invocation as a
* performance optimization as specified by the given JSFreeOp instance.
*/
extern JS_PUBLIC_API(void)
JS_freeop(JSFreeOp* fop, void* p);
extern JS_PUBLIC_API(void)
JS_updateMallocCounter(JSContext* cx, size_t nbytes);
/*
* A replacement for MallocAllocPolicy that allocates in the JS heap and adds no
* extra behaviours.
*
* This is currently used for allocating source buffers for parsing. Since these
* are temporary and will not be freed by GC, the memory is not tracked by the
* usual accounting.
*/
class JS_PUBLIC_API(JSMallocAllocPolicy) : public js::AllocPolicyBase
{
public:
void reportAllocOverflow() const {}
MOZ_MUST_USE bool checkSimulatedOOM() const {
return true;
}
};
/**
* Set the size of the native stack that should not be exceed. To disable
* stack size checking pass 0.
*
* SpiderMonkey allows for a distinction between system code (such as GCs, which
* may incidentally be triggered by script but are not strictly performed on
* behalf of such script), trusted script (as determined by JS_SetTrustedPrincipals),
* and untrusted script. Each kind of code may have a different stack quota,
* allowing embedders to keep higher-priority machinery running in the face of
* scripted stack exhaustion by something else.
*
* The stack quotas for each kind of code should be monotonically descending,
* and may be specified with this function. If 0 is passed for a given kind
* of code, it defaults to the value of the next-highest-priority kind.
*
* This function may only be called immediately after the runtime is initialized
* and before any code is executed and/or interrupts requested.
*/
extern JS_PUBLIC_API(void)
JS_SetNativeStackQuota(JSContext* cx, size_t systemCodeStackSize,
size_t trustedScriptStackSize = 0,
size_t untrustedScriptStackSize = 0);
/************************************************************************/
extern JS_PUBLIC_API(bool)
JS_ValueToId(JSContext* cx, JS::HandleValue v, JS::MutableHandleId idp);
extern JS_PUBLIC_API(bool)
JS_StringToId(JSContext* cx, JS::HandleString s, JS::MutableHandleId idp);
extern JS_PUBLIC_API(bool)
JS_IdToValue(JSContext* cx, jsid id, JS::MutableHandle<JS::Value> vp);
namespace JS {
/**
* Convert obj to a primitive value. On success, store the result in vp and
* return true.
*
* The hint argument must be JSTYPE_STRING, JSTYPE_NUMBER, or
* JSTYPE_UNDEFINED (no hint).
*
* Implements: ES6 7.1.1 ToPrimitive(input, [PreferredType]).
*/
extern JS_PUBLIC_API(bool)
ToPrimitive(JSContext* cx, JS::HandleObject obj, JSType hint, JS::MutableHandleValue vp);
/**
* If args.get(0) is one of the strings "string", "number", or "default", set
* result to JSTYPE_STRING, JSTYPE_NUMBER, or JSTYPE_UNDEFINED accordingly and
* return true. Otherwise, return false with a TypeError pending.
*
* This can be useful in implementing a @@toPrimitive method.
*/
extern JS_PUBLIC_API(bool)
GetFirstArgumentAsTypeHint(JSContext* cx, CallArgs args, JSType *result);
} /* namespace JS */
template<typename T>
struct JSConstScalarSpec {
const char* name;
T val;
};
typedef JSConstScalarSpec<double> JSConstDoubleSpec;
typedef JSConstScalarSpec<int32_t> JSConstIntegerSpec;
struct JSJitInfo;
/**
* Wrapper to relace JSNative for JSPropertySpecs and JSFunctionSpecs. This will
* allow us to pass one JSJitInfo per function with the property/function spec,
* without additional field overhead.
*/
struct JSNativeWrapper {
JSNative op;
const JSJitInfo* info;
};
/*
* Macro static initializers which make it easy to pass no JSJitInfo as part of a
* JSPropertySpec or JSFunctionSpec.
*/
#define JSNATIVE_WRAPPER(native) { {native, nullptr} }
/**
* Description of a property. JS_DefineProperties and JS_InitClass take arrays
* of these and define many properties at once. JS_PSG, JS_PSGS and JS_PS_END
* are helper macros for defining such arrays.
*/
struct JSPropertySpec {
struct SelfHostedWrapper {
void* unused;
const char* funname;
};
struct ValueWrapper {
uintptr_t type;
union {
const char* string;
int32_t int32;
};
};
const char* name;
uint8_t flags;
union {
struct {
union {
JSNativeWrapper native;
SelfHostedWrapper selfHosted;
} getter;
union {
JSNativeWrapper native;
SelfHostedWrapper selfHosted;
} setter;
} accessors;
ValueWrapper value;
};
bool isAccessor() const {
return !(flags & JSPROP_INTERNAL_USE_BIT);
}
JS_PUBLIC_API(bool) getValue(JSContext* cx, JS::MutableHandleValue value) const;
bool isSelfHosted() const {
MOZ_ASSERT(isAccessor());
#ifdef DEBUG
// Verify that our accessors match our JSPROP_GETTER flag.
if (flags & JSPROP_GETTER)
checkAccessorsAreSelfHosted();
else
checkAccessorsAreNative();
#endif
return (flags & JSPROP_GETTER);
}
static_assert(sizeof(SelfHostedWrapper) == sizeof(JSNativeWrapper),
"JSPropertySpec::getter/setter must be compact");
static_assert(offsetof(SelfHostedWrapper, funname) == offsetof(JSNativeWrapper, info),
"JS_SELF_HOSTED* macros below require that "
"SelfHostedWrapper::funname overlay "
"JSNativeWrapper::info");
private:
void checkAccessorsAreNative() const {
MOZ_ASSERT(accessors.getter.native.op);
// We may not have a setter at all. So all we can assert here, for the
// native case is that if we have a jitinfo for the setter then we have
// a setter op too. This is good enough to make sure we don't have a
// SelfHostedWrapper for the setter.
MOZ_ASSERT_IF(accessors.setter.native.info, accessors.setter.native.op);
}
void checkAccessorsAreSelfHosted() const {
MOZ_ASSERT(!accessors.getter.selfHosted.unused);
MOZ_ASSERT(!accessors.setter.selfHosted.unused);
}
};
namespace JS {
namespace detail {
/* NEVER DEFINED, DON'T USE. For use by JS_CAST_STRING_TO only. */
template<size_t N>
inline int
CheckIsCharacterLiteral(const char (&arr)[N]);
/* NEVER DEFINED, DON'T USE. For use by JS_CAST_INT32_TO only. */
inline int CheckIsInt32(int32_t value);
} // namespace detail
} // namespace JS
#define JS_CAST_STRING_TO(s, To) \
(static_cast<void>(sizeof(JS::detail::CheckIsCharacterLiteral(s))), \
reinterpret_cast<To>(s))
#define JS_CAST_INT32_TO(s, To) \
(static_cast<void>(sizeof(JS::detail::CheckIsInt32(s))), \
reinterpret_cast<To>(s))
#define JS_CHECK_ACCESSOR_FLAGS(flags) \
(static_cast<mozilla::EnableIf<((flags) & ~(JSPROP_ENUMERATE | JSPROP_PERMANENT)) == 0>::Type>(0), \
(flags))
#define JS_PS_ACCESSOR_SPEC(name, getter, setter, flags, extraFlags) \
{ name, uint8_t(JS_CHECK_ACCESSOR_FLAGS(flags) | extraFlags), \
{ { getter, setter } } }
#define JS_PS_VALUE_SPEC(name, value, flags) \
{ name, uint8_t(flags | JSPROP_INTERNAL_USE_BIT), \
{ { value, JSNATIVE_WRAPPER(nullptr) } } }
#define SELFHOSTED_WRAPPER(name) \
{ { nullptr, JS_CAST_STRING_TO(name, const JSJitInfo*) } }
#define STRINGVALUE_WRAPPER(value) \
{ { reinterpret_cast<JSNative>(JSVAL_TYPE_STRING), JS_CAST_STRING_TO(value, const JSJitInfo*) } }
#define INT32VALUE_WRAPPER(value) \
{ { reinterpret_cast<JSNative>(JSVAL_TYPE_INT32), JS_CAST_INT32_TO(value, const JSJitInfo*) } }
/*
* JSPropertySpec uses JSNativeWrapper. These macros encapsulate the definition
* of JSNative-backed JSPropertySpecs, by defining the JSNativeWrappers for
* them.
*/
#define JS_PSG(name, getter, flags) \
JS_PS_ACCESSOR_SPEC(name, JSNATIVE_WRAPPER(getter), JSNATIVE_WRAPPER(nullptr), flags, \
0)
#define JS_PSGS(name, getter, setter, flags) \
JS_PS_ACCESSOR_SPEC(name, JSNATIVE_WRAPPER(getter), JSNATIVE_WRAPPER(setter), flags, \
0)
#define JS_SYM_GET(symbol, getter, flags) \
JS_PS_ACCESSOR_SPEC(reinterpret_cast<const char*>(uint32_t(::JS::SymbolCode::symbol) + 1), \
JSNATIVE_WRAPPER(getter), JSNATIVE_WRAPPER(nullptr), flags, 0)
#define JS_SELF_HOSTED_GET(name, getterName, flags) \
JS_PS_ACCESSOR_SPEC(name, SELFHOSTED_WRAPPER(getterName), JSNATIVE_WRAPPER(nullptr), flags, \
JSPROP_GETTER)
#define JS_SELF_HOSTED_GETSET(name, getterName, setterName, flags) \
JS_PS_ACCESSOR_SPEC(name, SELFHOSTED_WRAPPER(getterName), SELFHOSTED_WRAPPER(setterName), \
flags, JSPROP_GETTER | JSPROP_SETTER)
#define JS_SELF_HOSTED_SYM_GET(symbol, getterName, flags) \
JS_PS_ACCESSOR_SPEC(reinterpret_cast<const char*>(uint32_t(::JS::SymbolCode::symbol) + 1), \
SELFHOSTED_WRAPPER(getterName), JSNATIVE_WRAPPER(nullptr), flags, \
JSPROP_GETTER)
#define JS_STRING_PS(name, string, flags) \
JS_PS_VALUE_SPEC(name, STRINGVALUE_WRAPPER(string), flags)
#define JS_STRING_SYM_PS(symbol, string, flags) \
JS_PS_VALUE_SPEC(reinterpret_cast<const char*>(uint32_t(::JS::SymbolCode::symbol) + 1), \
STRINGVALUE_WRAPPER(string), flags)
#define JS_INT32_PS(name, value, flags) \
JS_PS_VALUE_SPEC(name, INT32VALUE_WRAPPER(value), flags)
#define JS_PS_END \
JS_PS_ACCESSOR_SPEC(nullptr, JSNATIVE_WRAPPER(nullptr), JSNATIVE_WRAPPER(nullptr), 0, 0)
/**
* To define a native function, set call to a JSNativeWrapper. To define a
* self-hosted function, set selfHostedName to the name of a function
* compiled during JSRuntime::initSelfHosting.
*/
struct JSFunctionSpec {
const char* name;
JSNativeWrapper call;
uint16_t nargs;
uint16_t flags;
const char* selfHostedName;
};
/*
* Terminating sentinel initializer to put at the end of a JSFunctionSpec array
* that's passed to JS_DefineFunctions or JS_InitClass.
*/
#define JS_FS_END JS_FN(nullptr,nullptr,0,0)
/*
* Initializer macros for a JSFunctionSpec array element. JS_FNINFO allows the
* simple adding of JSJitInfos. JS_SELF_HOSTED_FN declares a self-hosted
* function. JS_INLINABLE_FN allows specifying an InlinableNative enum value for
* natives inlined or specialized by the JIT. Finally JS_FNSPEC has slots for
* all the fields.
*
* The _SYM variants allow defining a function with a symbol key rather than a
* string key. For example, use JS_SYM_FN(iterator, ...) to define an
* @@iterator method.
*/
#define JS_FN(name,call,nargs,flags) \
JS_FNSPEC(name, call, nullptr, nargs, flags, nullptr)
#define JS_INLINABLE_FN(name,call,nargs,flags,native) \
JS_FNSPEC(name, call, &js::jit::JitInfo_##native, nargs, flags, nullptr)
#define JS_SYM_FN(symbol,call,nargs,flags) \
JS_SYM_FNSPEC(symbol, call, nullptr, nargs, flags, nullptr)
#define JS_FNINFO(name,call,info,nargs,flags) \
JS_FNSPEC(name, call, info, nargs, flags, nullptr)
#define JS_SELF_HOSTED_FN(name,selfHostedName,nargs,flags) \
JS_FNSPEC(name, nullptr, nullptr, nargs, flags, selfHostedName)
#define JS_SELF_HOSTED_SYM_FN(symbol, selfHostedName, nargs, flags) \
JS_SYM_FNSPEC(symbol, nullptr, nullptr, nargs, flags, selfHostedName)
#define JS_SYM_FNSPEC(symbol, call, info, nargs, flags, selfHostedName) \
JS_FNSPEC(reinterpret_cast<const char*>( \
uint32_t(::JS::SymbolCode::symbol) + 1), \
call, info, nargs, flags, selfHostedName)
#define JS_FNSPEC(name,call,info,nargs,flags,selfHostedName) \
{name, {call, info}, nargs, flags, selfHostedName}
extern JS_PUBLIC_API(JSObject*)
JS_InitClass(JSContext* cx, JS::HandleObject obj, JS::HandleObject parent_proto,
const JSClass* clasp, JSNative constructor, unsigned nargs,
const JSPropertySpec* ps, const JSFunctionSpec* fs,
const JSPropertySpec* static_ps, const JSFunctionSpec* static_fs);
/**
* Set up ctor.prototype = proto and proto.constructor = ctor with the
* right property flags.
*/
extern JS_PUBLIC_API(bool)
JS_LinkConstructorAndPrototype(JSContext* cx, JS::Handle<JSObject*> ctor,
JS::Handle<JSObject*> proto);
extern JS_PUBLIC_API(const JSClass*)
JS_GetClass(JSObject* obj);
extern JS_PUBLIC_API(bool)
JS_InstanceOf(JSContext* cx, JS::Handle<JSObject*> obj, const JSClass* clasp, JS::CallArgs* args);
extern JS_PUBLIC_API(bool)
JS_HasInstance(JSContext* cx, JS::Handle<JSObject*> obj, JS::Handle<JS::Value> v, bool* bp);
namespace JS {
// Implementation of
// you're looking for the equivalent of "instanceof", you want JS_HasInstance,
// not this function.
extern JS_PUBLIC_API(bool)
OrdinaryHasInstance(JSContext* cx, HandleObject objArg, HandleValue v, bool* bp);
} // namespace JS
extern JS_PUBLIC_API(void*)
JS_GetPrivate(JSObject* obj);
extern JS_PUBLIC_API(void)
JS_SetPrivate(JSObject* obj, void* data);
extern JS_PUBLIC_API(void*)
JS_GetInstancePrivate(JSContext* cx, JS::Handle<JSObject*> obj, const JSClass* clasp,
JS::CallArgs* args);
extern JS_PUBLIC_API(JSObject*)
JS_GetConstructor(JSContext* cx, JS::Handle<JSObject*> proto);
namespace JS {
// Specification for which compartment/zone a newly created realm should use.
enum class CompartmentSpecifier {
// Create a new realm and compartment in the single runtime wide system
// zone. The meaning of this zone is left to the embedder.
NewCompartmentInSystemZone,
// Create a new realm and compartment in a particular existing zone.
NewCompartmentInExistingZone,
// Create a new zone/compartment.
NewCompartmentAndZone,
// Create a new realm in an existing compartment.
ExistingCompartment,
};
/**
* RealmCreationOptions specifies options relevant to creating a new realm, that
* are either immutable characteristics of that realm or that are discarded
* after the realm has been created.
*
* Access to these options on an existing realm is read-only: if you need
* particular selections, make them before you create the realm.
*/
class JS_PUBLIC_API(RealmCreationOptions)
{
public:
RealmCreationOptions()
: traceGlobal_(nullptr),
compSpec_(CompartmentSpecifier::NewCompartmentAndZone),
comp_(nullptr),
invisibleToDebugger_(false),
mergeable_(false),
preserveJitCode_(false),
cloneSingletons_(false),
sharedMemoryAndAtomics_(false),
secureContext_(false),
clampAndJitterTime_(true)
{}
JSTraceOp getTrace() const {
return traceGlobal_;
}
RealmCreationOptions& setTrace(JSTraceOp op) {
traceGlobal_ = op;
return *this;
}
JS::Zone* zone() const {
MOZ_ASSERT(compSpec_ == CompartmentSpecifier::NewCompartmentInExistingZone);
return zone_;
}
JS::Compartment* compartment() const {
MOZ_ASSERT(compSpec_ == CompartmentSpecifier::ExistingCompartment);
return comp_;
}
CompartmentSpecifier compartmentSpecifier() const { return compSpec_; }
// Set the compartment/zone to use for the realm. See CompartmentSpecifier above.
RealmCreationOptions& setNewCompartmentInSystemZone();
RealmCreationOptions& setNewCompartmentInExistingZone(JSObject* obj);
RealmCreationOptions& setNewCompartmentAndZone();
RealmCreationOptions& setExistingCompartment(JSObject* obj);
// Certain scopes (i.e. XBL compilation scopes) are implementation details
// of the embedding, and references to them should never leak out to script.
// This flag causes the this realm to skip firing onNewGlobalObject and
// makes addDebuggee a no-op for this global.
bool invisibleToDebugger() const { return invisibleToDebugger_; }
RealmCreationOptions& setInvisibleToDebugger(bool flag) {
invisibleToDebugger_ = flag;
return *this;
}
// Realms used for off-thread compilation have their contents merged into a
// target realm when the compilation is finished. This is only allowed if
// this flag is set. The invisibleToDebugger flag must also be set for such
// realms.
bool mergeable() const { return mergeable_; }
RealmCreationOptions& setMergeable(bool flag) {
mergeable_ = flag;
return *this;
}
// Determines whether this realm should preserve JIT code on non-shrinking
// GCs.
bool preserveJitCode() const { return preserveJitCode_; }
RealmCreationOptions& setPreserveJitCode(bool flag) {
preserveJitCode_ = flag;
return *this;
}
bool cloneSingletons() const { return cloneSingletons_; }
RealmCreationOptions& setCloneSingletons(bool flag) {
cloneSingletons_ = flag;
return *this;
}
bool getSharedMemoryAndAtomicsEnabled() const;
RealmCreationOptions& setSharedMemoryAndAtomicsEnabled(bool flag);
// This flag doesn't affect JS engine behavior. It is used by Gecko to
// mark whether content windows and workers are "Secure Context"s. See
bool secureContext() const { return secureContext_; }
RealmCreationOptions& setSecureContext(bool flag) {
secureContext_ = flag;
return *this;
}
bool clampAndJitterTime() const { return clampAndJitterTime_; }
RealmCreationOptions& setClampAndJitterTime(bool flag) {
clampAndJitterTime_ = flag;
return *this;
}
private:
JSTraceOp traceGlobal_;
CompartmentSpecifier compSpec_;
union {
JS::Compartment* comp_;
JS::Zone* zone_;
};
bool invisibleToDebugger_;
bool mergeable_;
bool preserveJitCode_;
bool cloneSingletons_;
bool sharedMemoryAndAtomics_;
bool secureContext_;
bool clampAndJitterTime_;
};
/**
* RealmBehaviors specifies behaviors of a realm that can be changed after the
* realm's been created.
*/
class JS_PUBLIC_API(RealmBehaviors)
{
public:
class Override {
public:
Override() : mode_(Default) {}
bool get(bool defaultValue) const {
if (mode_ == Default)
return defaultValue;
return mode_ == ForceTrue;
}
void set(bool overrideValue) {
mode_ = overrideValue ? ForceTrue : ForceFalse;
}
void reset() {
mode_ = Default;
}
private:
enum Mode {
Default,
ForceTrue,
ForceFalse
};
Mode mode_;
};
RealmBehaviors()
: discardSource_(false)
, disableLazyParsing_(false)
, singletonsAsTemplates_(true)
{
}
// For certain globals, we know enough about the code that will run in them
// that we can discard script source entirely.
bool discardSource() const { return discardSource_; }
RealmBehaviors& setDiscardSource(bool flag) {
discardSource_ = flag;
return *this;
}
bool disableLazyParsing() const { return disableLazyParsing_; }
RealmBehaviors& setDisableLazyParsing(bool flag) {
disableLazyParsing_ = flag;
return *this;
}
bool extraWarnings(JSContext* cx) const;
Override& extraWarningsOverride() { return extraWarningsOverride_; }
bool getSingletonsAsTemplates() const {
return singletonsAsTemplates_;
}
RealmBehaviors& setSingletonsAsValues() {
singletonsAsTemplates_ = false;
return *this;
}
private:
bool discardSource_;
bool disableLazyParsing_;
Override extraWarningsOverride_;
// To XDR singletons, we need to ensure that all singletons are all used as
// templates, by making JSOP_OBJECT return a clone of the JSScript
// singleton, instead of returning the value which is baked in the JSScript.
bool singletonsAsTemplates_;
};
/**
* RealmOptions specifies realm characteristics: both those that can't be
* changed on a realm once it's been created (RealmCreationOptions), and those
* that can be changed on an existing realm (RealmBehaviors).
*/
class JS_PUBLIC_API(RealmOptions)
{
public:
explicit RealmOptions()
: creationOptions_(),
behaviors_()
{}
RealmOptions(const RealmCreationOptions& realmCreation, const RealmBehaviors& realmBehaviors)
: creationOptions_(realmCreation),
behaviors_(realmBehaviors)
{}
// RealmCreationOptions specify fundamental realm characteristics that must
// be specified when the realm is created, that can't be changed after the
// realm is created.
RealmCreationOptions& creationOptions() {
return creationOptions_;
}
const RealmCreationOptions& creationOptions() const {
return creationOptions_;
}
// RealmBehaviors specify realm characteristics that can be changed after
// the realm is created.
RealmBehaviors& behaviors() {
return behaviors_;
}
const RealmBehaviors& behaviors() const {
return behaviors_;
}
private:
RealmCreationOptions creationOptions_;
RealmBehaviors behaviors_;
};
JS_PUBLIC_API(const RealmCreationOptions&)
RealmCreationOptionsRef(JS::Realm* realm);
JS_PUBLIC_API(const RealmCreationOptions&)
RealmCreationOptionsRef(JSContext* cx);
JS_PUBLIC_API(RealmBehaviors&)
RealmBehaviorsRef(JS::Realm* realm);
JS_PUBLIC_API(RealmBehaviors&)
RealmBehaviorsRef(JSContext* cx);
/**
* During global creation, we fire notifications to callbacks registered
* via the Debugger API. These callbacks are arbitrary script, and can touch
* the global in arbitrary ways. When that happens, the global should not be
* in a half-baked state. But this creates a problem for consumers that need
* to set slots on the global to put it in a consistent state.
*
* This API provides a way for consumers to set slots atomically (immediately
* after the global is created), before any debugger hooks are fired. It's
* unfortunately on the clunky side, but that's the way the cookie crumbles.
*
* If callers have no additional state on the global to set up, they may pass
* |FireOnNewGlobalHook| to JS_NewGlobalObject, which causes that function to
* fire the hook as its final act before returning. Otherwise, callers should
* pass |DontFireOnNewGlobalHook|, which means that they are responsible for
* invoking JS_FireOnNewGlobalObject upon successfully creating the global. If
* an error occurs and the operation aborts, callers should skip firing the
* hook. But otherwise, callers must take care to fire the hook exactly once
* before compiling any script in the global's scope (we have assertions in
* place to enforce this). This lets us be sure that debugger clients never miss
* breakpoints.
*/
enum OnNewGlobalHookOption {
FireOnNewGlobalHook,
DontFireOnNewGlobalHook
};
} /* namespace JS */
extern JS_PUBLIC_API(JSObject*)
JS_NewGlobalObject(JSContext* cx, const JSClass* clasp, JSPrincipals* principals,
JS::OnNewGlobalHookOption hookOption,
const JS::RealmOptions& options);
/**
* Spidermonkey does not have a good way of keeping track of what compartments should be marked on
* their own. We can mark the roots unconditionally, but marking GC things only relevant in live
* compartments is hard. To mitigate this, we create a static trace hook, installed on each global
* object, from which we can be sure the compartment is relevant, and mark it.
*
* It is still possible to specify custom trace hooks for global object classes. They can be
* provided via the RealmOptions passed to JS_NewGlobalObject.
*/
extern JS_PUBLIC_API(void)
JS_GlobalObjectTraceHook(JSTracer* trc, JSObject* global);
extern JS_PUBLIC_API(void)
JS_FireOnNewGlobalObject(JSContext* cx, JS::HandleObject global);
extern JS_PUBLIC_API(JSObject*)
JS_NewObject(JSContext* cx, const JSClass* clasp);
extern JS_PUBLIC_API(bool)
JS_IsNative(JSObject* obj);
/**
* Unlike JS_NewObject, JS_NewObjectWithGivenProto does not compute a default
* proto. If proto is nullptr, the JS object will have `null` as [[Prototype]].
*/
extern JS_PUBLIC_API(JSObject*)
JS_NewObjectWithGivenProto(JSContext* cx, const JSClass* clasp, JS::Handle<JSObject*> proto);
/** Creates a new plain object, like `new Object()`, with Object.prototype as [[Prototype]]. */
extern JS_PUBLIC_API(JSObject*)
JS_NewPlainObject(JSContext* cx);
/**
* Freeze obj, and all objects it refers to, recursively. This will not recurse
* through non-extensible objects, on the assumption that those are already
* deep-frozen.
*/
extern JS_PUBLIC_API(bool)
JS_DeepFreezeObject(JSContext* cx, JS::Handle<JSObject*> obj);
/**
* Freezes an object; see ES5's Object.freeze(obj) method.
*/
extern JS_PUBLIC_API(bool)
JS_FreezeObject(JSContext* cx, JS::Handle<JSObject*> obj);
/*** Property descriptors ************************************************************************/
namespace JS {
struct JS_PUBLIC_API(PropertyDescriptor) {
JSObject* obj;
unsigned attrs;
JSGetterOp getter;
JSSetterOp setter;
JS::Value value;
PropertyDescriptor()
: obj(nullptr), attrs(0), getter(nullptr), setter(nullptr), value(JS::UndefinedValue())
{}
static void trace(PropertyDescriptor* self, JSTracer* trc) { self->trace(trc); }
void trace(JSTracer* trc);
};
} // namespace JS
namespace js {
template <typename Wrapper>
class WrappedPtrOperations<JS::PropertyDescriptor, Wrapper>
{
const JS::PropertyDescriptor& desc() const { return static_cast<const Wrapper*>(this)->get(); }
bool has(unsigned bit) const {
MOZ_ASSERT(bit != 0);
MOZ_ASSERT((bit & (bit - 1)) == 0); // only a single bit
return (desc().attrs & bit) != 0;
}
bool hasAny(unsigned bits) const {
return (desc().attrs & bits) != 0;
}
bool hasAll(unsigned bits) const {
return (desc().attrs & bits) == bits;
}
public:
// Descriptors with JSGetterOp/JSSetterOp are considered data
// descriptors. It's complicated.
bool isAccessorDescriptor() const { return hasAny(JSPROP_GETTER | JSPROP_SETTER); }
bool isGenericDescriptor() const {
return (desc().attrs&
(JSPROP_GETTER | JSPROP_SETTER | JSPROP_IGNORE_READONLY | JSPROP_IGNORE_VALUE)) ==
(JSPROP_IGNORE_READONLY | JSPROP_IGNORE_VALUE);
}
bool isDataDescriptor() const { return !isAccessorDescriptor() && !isGenericDescriptor(); }
bool hasConfigurable() const { return !has(JSPROP_IGNORE_PERMANENT); }
bool configurable() const { MOZ_ASSERT(hasConfigurable()); return !has(JSPROP_PERMANENT); }
bool hasEnumerable() const { return !has(JSPROP_IGNORE_ENUMERATE); }
bool enumerable() const { MOZ_ASSERT(hasEnumerable()); return has(JSPROP_ENUMERATE); }
bool hasValue() const { return !isAccessorDescriptor() && !has(JSPROP_IGNORE_VALUE); }
JS::HandleValue value() const {
return JS::HandleValue::fromMarkedLocation(&desc().value);
}
bool hasWritable() const { return !isAccessorDescriptor() && !has(JSPROP_IGNORE_READONLY); }
bool writable() const { MOZ_ASSERT(hasWritable()); return !has(JSPROP_READONLY); }
bool hasGetterObject() const { return has(JSPROP_GETTER); }
JS::HandleObject getterObject() const {
MOZ_ASSERT(hasGetterObject());
return JS::HandleObject::fromMarkedLocation(
reinterpret_cast<JSObject* const*>(&desc().getter));
}
bool hasSetterObject() const { return has(JSPROP_SETTER); }
JS::HandleObject setterObject() const {
MOZ_ASSERT(hasSetterObject());
return JS::HandleObject::fromMarkedLocation(
reinterpret_cast<JSObject* const*>(&desc().setter));
}
bool hasGetterOrSetter() const { return desc().getter || desc().setter; }
JS::HandleObject object() const {
return JS::HandleObject::fromMarkedLocation(&desc().obj);
}
unsigned attributes() const { return desc().attrs; }
JSGetterOp getter() const { return desc().getter; }
JSSetterOp setter() const { return desc().setter; }
void assertValid() const {
#ifdef DEBUG
MOZ_ASSERT((attributes() & ~(JSPROP_ENUMERATE | JSPROP_IGNORE_ENUMERATE |
JSPROP_PERMANENT | JSPROP_IGNORE_PERMANENT |
JSPROP_READONLY | JSPROP_IGNORE_READONLY |
JSPROP_IGNORE_VALUE |
JSPROP_GETTER |
JSPROP_SETTER |
JSPROP_RESOLVING |
JSPROP_INTERNAL_USE_BIT)) == 0);
MOZ_ASSERT(!hasAll(JSPROP_IGNORE_ENUMERATE | JSPROP_ENUMERATE));
MOZ_ASSERT(!hasAll(JSPROP_IGNORE_PERMANENT | JSPROP_PERMANENT));
if (isAccessorDescriptor()) {
MOZ_ASSERT(!has(JSPROP_READONLY));
MOZ_ASSERT(!has(JSPROP_IGNORE_READONLY));
MOZ_ASSERT(!has(JSPROP_IGNORE_VALUE));
MOZ_ASSERT(!has(JSPROP_INTERNAL_USE_BIT));
MOZ_ASSERT(value().isUndefined());
MOZ_ASSERT_IF(!has(JSPROP_GETTER), !getter());
MOZ_ASSERT_IF(!has(JSPROP_SETTER), !setter());
} else {
MOZ_ASSERT(!hasAll(JSPROP_IGNORE_READONLY | JSPROP_READONLY));
MOZ_ASSERT_IF(has(JSPROP_IGNORE_VALUE), value().isUndefined());
}
MOZ_ASSERT_IF(has(JSPROP_RESOLVING), !has(JSPROP_IGNORE_ENUMERATE));
MOZ_ASSERT_IF(has(JSPROP_RESOLVING), !has(JSPROP_IGNORE_PERMANENT));
MOZ_ASSERT_IF(has(JSPROP_RESOLVING), !has(JSPROP_IGNORE_READONLY));
MOZ_ASSERT_IF(has(JSPROP_RESOLVING), !has(JSPROP_IGNORE_VALUE));
#endif
}
void assertComplete() const {
#ifdef DEBUG
assertValid();
MOZ_ASSERT((attributes() & ~(JSPROP_ENUMERATE |
JSPROP_PERMANENT |
JSPROP_READONLY |
JSPROP_GETTER |
JSPROP_SETTER |
JSPROP_RESOLVING |
JSPROP_INTERNAL_USE_BIT)) == 0);
MOZ_ASSERT_IF(isAccessorDescriptor(), has(JSPROP_GETTER) && has(JSPROP_SETTER));
#endif
}
void assertCompleteIfFound() const {
#ifdef DEBUG
if (object())
assertComplete();
#endif
}
};
template <typename Wrapper>
class MutableWrappedPtrOperations<JS::PropertyDescriptor, Wrapper>
: public js::WrappedPtrOperations<JS::PropertyDescriptor, Wrapper>
{
JS::PropertyDescriptor& desc() { return static_cast<Wrapper*>(this)->get(); }
public:
void clear() {
object().set(nullptr);
setAttributes(0);
setGetter(nullptr);
setSetter(nullptr);
value().setUndefined();
}
void initFields(JS::HandleObject obj, JS::HandleValue v, unsigned attrs,
JSGetterOp getterOp, JSSetterOp setterOp) {
object().set(obj);
value().set(v);
setAttributes(attrs);
setGetter(getterOp);
setSetter(setterOp);
}
void assign(JS::PropertyDescriptor& other) {
object().set(other.obj);
setAttributes(other.attrs);
setGetter(other.getter);
setSetter(other.setter);
value().set(other.value);
}
void setDataDescriptor(JS::HandleValue v, unsigned attrs) {
MOZ_ASSERT((attrs & ~(JSPROP_ENUMERATE |
JSPROP_PERMANENT |
JSPROP_READONLY |
JSPROP_IGNORE_ENUMERATE |
JSPROP_IGNORE_PERMANENT |
JSPROP_IGNORE_READONLY)) == 0);
object().set(nullptr);
setAttributes(attrs);
setGetter(nullptr);
setSetter(nullptr);
value().set(v);
}
JS::MutableHandleObject object() {
return JS::MutableHandleObject::fromMarkedLocation(&desc().obj);
}
unsigned& attributesRef() { return desc().attrs; }
JSGetterOp& getter() { return desc().getter; }
JSSetterOp& setter() { return desc().setter; }
JS::MutableHandleValue value() {
return JS::MutableHandleValue::fromMarkedLocation(&desc().value);
}
void setValue(JS::HandleValue v) {
MOZ_ASSERT(!(desc().attrs & (JSPROP_GETTER | JSPROP_SETTER)));
attributesRef() &= ~JSPROP_IGNORE_VALUE;
value().set(v);
}
void setConfigurable(bool configurable) {
setAttributes((desc().attrs & ~(JSPROP_IGNORE_PERMANENT | JSPROP_PERMANENT)) |
(configurable ? 0 : JSPROP_PERMANENT));
}
void setEnumerable(bool enumerable) {
setAttributes((desc().attrs & ~(JSPROP_IGNORE_ENUMERATE | JSPROP_ENUMERATE)) |
(enumerable ? JSPROP_ENUMERATE : 0));
}
void setWritable(bool writable) {
MOZ_ASSERT(!(desc().attrs & (JSPROP_GETTER | JSPROP_SETTER)));
setAttributes((desc().attrs & ~(JSPROP_IGNORE_READONLY | JSPROP_READONLY)) |
(writable ? 0 : JSPROP_READONLY));
}
void setAttributes(unsigned attrs) { desc().attrs = attrs; }
void setGetter(JSGetterOp op) {
desc().getter = op;
}
void setSetter(JSSetterOp op) {
desc().setter = op;
}
void setGetterObject(JSObject* obj) {
desc().getter = reinterpret_cast<JSGetterOp>(obj);
desc().attrs &= ~(JSPROP_IGNORE_VALUE | JSPROP_IGNORE_READONLY | JSPROP_READONLY);
desc().attrs |= JSPROP_GETTER;
}
void setSetterObject(JSObject* obj) {
desc().setter = reinterpret_cast<JSSetterOp>(obj);
desc().attrs &= ~(JSPROP_IGNORE_VALUE | JSPROP_IGNORE_READONLY | JSPROP_READONLY);
desc().attrs |= JSPROP_SETTER;
}
JS::MutableHandleObject getterObject() {
MOZ_ASSERT(this->hasGetterObject());
return JS::MutableHandleObject::fromMarkedLocation(
reinterpret_cast<JSObject**>(&desc().getter));
}
JS::MutableHandleObject setterObject() {
MOZ_ASSERT(this->hasSetterObject());
return JS::MutableHandleObject::fromMarkedLocation(
reinterpret_cast<JSObject**>(&desc().setter));
}
};
} // namespace js
namespace JS {
extern JS_PUBLIC_API(bool)
ObjectToCompletePropertyDescriptor(JSContext* cx,
JS::HandleObject obj,
JS::HandleValue descriptor,
JS::MutableHandle<PropertyDescriptor> desc);
/*
* ES6 draft rev 32 (2015 Feb 2) 6.2.4.4 FromPropertyDescriptor(Desc).
*
* If desc.object() is null, then vp is set to undefined.
*/
extern JS_PUBLIC_API(bool)
FromPropertyDescriptor(JSContext* cx,
JS::Handle<JS::PropertyDescriptor> desc,
JS::MutableHandleValue vp);
} // namespace JS
/*** Standard internal methods ********************************************************************
*
* The functions below are the fundamental operations on objects.
*
* ES6 specifies 14 internal methods that define how objects behave. The
* standard is actually quite good on this topic, though you may have to read
* it a few times. See ES6 sections 6.1.7.2 and 6.1.7.3.
*
* When 'obj' is an ordinary object, these functions have boring standard
* behavior as specified by ES6 section 9.1; see the section about internal
* methods in js/src/vm/NativeObject.h.
*
* Proxies override the behavior of internal methods. So when 'obj' is a proxy,
* any one of the functions below could do just about anything. See
* js/public/Proxy.h.
*/
/**
* Get the prototype of obj, storing it in result.
*
* Implements: ES6 [[GetPrototypeOf]] internal method.
*/
extern JS_PUBLIC_API(bool)
JS_GetPrototype(JSContext* cx, JS::HandleObject obj, JS::MutableHandleObject result);
/**
* If |obj| (underneath any functionally-transparent wrapper proxies) has as
* its [[GetPrototypeOf]] trap the ordinary [[GetPrototypeOf]] behavior defined
* for ordinary objects, set |*isOrdinary = true| and store |obj|'s prototype
* in |result|. Otherwise set |*isOrdinary = false|. In case of error, both
* outparams have unspecified value.
*/
extern JS_PUBLIC_API(bool)
JS_GetPrototypeIfOrdinary(JSContext* cx, JS::HandleObject obj, bool* isOrdinary,
JS::MutableHandleObject result);
/**
* Change the prototype of obj.
*
* Implements: ES6 [[SetPrototypeOf]] internal method.
*
* In cases where ES6 [[SetPrototypeOf]] returns false without an exception,
* JS_SetPrototype throws a TypeError and returns false.
*
* Performance warning: JS_SetPrototype is very bad for performance. It may
* cause compiled jit-code to be invalidated. It also causes not only obj but
* all other objects in the same "group" as obj to be permanently deoptimized.
* It's better to create the object with the right prototype from the start.
*/
extern JS_PUBLIC_API(bool)
JS_SetPrototype(JSContext* cx, JS::HandleObject obj, JS::HandleObject proto);
/**
* Determine whether obj is extensible. Extensible objects can have new
* properties defined on them. Inextensible objects can't, and their
* [[Prototype]] slot is fixed as well.
*
* Implements: ES6 [[IsExtensible]] internal method.
*/
extern JS_PUBLIC_API(bool)
JS_IsExtensible(JSContext* cx, JS::HandleObject obj, bool* extensible);
/**
* Attempt to make |obj| non-extensible.
*
* Not all failures are treated as errors. See the comment on
* JS::ObjectOpResult in js/public/Class.h.
*
* Implements: ES6 [[PreventExtensions]] internal method.
*/
extern JS_PUBLIC_API(bool)
JS_PreventExtensions(JSContext* cx, JS::HandleObject obj, JS::ObjectOpResult& result);
/**
* Attempt to make the [[Prototype]] of |obj| immutable, such that any attempt
* to modify it will fail. If an error occurs during the attempt, return false
* (with a pending exception set, depending upon the nature of the error). If
* no error occurs, return true with |*succeeded| set to indicate whether the
* attempt successfully made the [[Prototype]] immutable.
*
* This is a nonstandard internal method.
*/
extern JS_PUBLIC_API(bool)
JS_SetImmutablePrototype(JSContext* cx, JS::HandleObject obj, bool* succeeded);
/**
* Get a description of one of obj's own properties. If no such property exists
* on obj, return true with desc.object() set to null.
*
* Implements: ES6 [[GetOwnProperty]] internal method.
*/
extern JS_PUBLIC_API(bool)
JS_GetOwnPropertyDescriptorById(JSContext* cx, JS::HandleObject obj, JS::HandleId id,
JS::MutableHandle<JS::PropertyDescriptor> desc);
extern JS_PUBLIC_API(bool)
JS_GetOwnPropertyDescriptor(JSContext* cx, JS::HandleObject obj, const char* name,
JS::MutableHandle<JS::PropertyDescriptor> desc);
extern JS_PUBLIC_API(bool)
JS_GetOwnUCPropertyDescriptor(JSContext* cx, JS::HandleObject obj, const char16_t* name,
JS::MutableHandle<JS::PropertyDescriptor> desc);
/**
* Like JS_GetOwnPropertyDescriptorById, but also searches the prototype chain
* if no own property is found directly on obj. The object on which the
* property is found is returned in desc.object(). If the property is not found
* on the prototype chain, this returns true with desc.object() set to null.
*/
extern JS_PUBLIC_API(bool)
JS_GetPropertyDescriptorById(JSContext* cx, JS::HandleObject obj, JS::HandleId id,
JS::MutableHandle<JS::PropertyDescriptor> desc);
extern JS_PUBLIC_API(bool)
JS_GetPropertyDescriptor(JSContext* cx, JS::HandleObject obj, const char* name,
JS::MutableHandle<JS::PropertyDescriptor> desc);
/**
* Define a property on obj.
*
* This function uses JS::ObjectOpResult to indicate conditions that ES6
* specifies as non-error failures. This is inconvenient at best, so use this
* function only if you are implementing a proxy handler's defineProperty()
* method. For all other purposes, use one of the many DefineProperty functions
* below that throw an exception in all failure cases.
*
* Implements: ES6 [[DefineOwnProperty]] internal method.
*/
extern JS_PUBLIC_API(bool)
JS_DefinePropertyById(JSContext* cx, JS::HandleObject obj, JS::HandleId id,
JS::Handle<JS::PropertyDescriptor> desc,
JS::ObjectOpResult& result);
/**
* Define a property on obj, throwing a TypeError if the attempt fails.
* This is the C++ equivalent of `Object.defineProperty(obj, id, desc)`.
*/
extern JS_PUBLIC_API(bool)
JS_DefinePropertyById(JSContext* cx, JS::HandleObject obj, JS::HandleId id,
JS::Handle<JS::PropertyDescriptor> desc);
extern JS_PUBLIC_API(bool)
JS_DefinePropertyById(JSContext* cx, JS::HandleObject obj, JS::HandleId id, JS::HandleValue value,
unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefinePropertyById(JSContext* cx, JS::HandleObject obj, JS::HandleId id, JSNative getter,
JSNative setter, unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefinePropertyById(JSContext* cx, JS::HandleObject obj, JS::HandleId id, JS::HandleObject getter,
JS::HandleObject setter, unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefinePropertyById(JSContext* cx, JS::HandleObject obj, JS::HandleId id, JS::HandleObject value,
unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefinePropertyById(JSContext* cx, JS::HandleObject obj, JS::HandleId id, JS::HandleString value,
unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefinePropertyById(JSContext* cx, JS::HandleObject obj, JS::HandleId id, int32_t value,
unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefinePropertyById(JSContext* cx, JS::HandleObject obj, JS::HandleId id, uint32_t value,
unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefinePropertyById(JSContext* cx, JS::HandleObject obj, JS::HandleId id, double value,
unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineProperty(JSContext* cx, JS::HandleObject obj, const char* name, JS::HandleValue value,
unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineProperty(JSContext* cx, JS::HandleObject obj, const char* name, JSNative getter,
JSNative setter, unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineProperty(JSContext* cx, JS::HandleObject obj, const char* name, JS::HandleObject getter,
JS::HandleObject setter, unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineProperty(JSContext* cx, JS::HandleObject obj, const char* name, JS::HandleObject value,
unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineProperty(JSContext* cx, JS::HandleObject obj, const char* name, JS::HandleString value,
unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineProperty(JSContext* cx, JS::HandleObject obj, const char* name, int32_t value,
unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineProperty(JSContext* cx, JS::HandleObject obj, const char* name, uint32_t value,
unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineProperty(JSContext* cx, JS::HandleObject obj, const char* name, double value,
unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineUCProperty(JSContext* cx, JS::HandleObject obj, const char16_t* name, size_t namelen,
JS::Handle<JS::PropertyDescriptor> desc,
JS::ObjectOpResult& result);
extern JS_PUBLIC_API(bool)
JS_DefineUCProperty(JSContext* cx, JS::HandleObject obj, const char16_t* name, size_t namelen,
JS::Handle<JS::PropertyDescriptor> desc);
extern JS_PUBLIC_API(bool)
JS_DefineUCProperty(JSContext* cx, JS::HandleObject obj, const char16_t* name, size_t namelen,
JS::HandleValue value, unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineUCProperty(JSContext* cx, JS::HandleObject obj, const char16_t* name, size_t namelen,
JS::HandleObject getter, JS::HandleObject setter, unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineUCProperty(JSContext* cx, JS::HandleObject obj, const char16_t* name, size_t namelen,
JS::HandleObject value, unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineUCProperty(JSContext* cx, JS::HandleObject obj, const char16_t* name, size_t namelen,
JS::HandleString value, unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineUCProperty(JSContext* cx, JS::HandleObject obj, const char16_t* name, size_t namelen,
int32_t value, unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineUCProperty(JSContext* cx, JS::HandleObject obj, const char16_t* name, size_t namelen,
uint32_t value, unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineUCProperty(JSContext* cx, JS::HandleObject obj, const char16_t* name, size_t namelen,
double value, unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineElement(JSContext* cx, JS::HandleObject obj, uint32_t index, JS::HandleValue value,
unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineElement(JSContext* cx, JS::HandleObject obj, uint32_t index, JS::HandleObject getter,
JS::HandleObject setter, unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineElement(JSContext* cx, JS::HandleObject obj, uint32_t index, JS::HandleObject value,
unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineElement(JSContext* cx, JS::HandleObject obj, uint32_t index, JS::HandleString value,
unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineElement(JSContext* cx, JS::HandleObject obj, uint32_t index, int32_t value,
unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineElement(JSContext* cx, JS::HandleObject obj, uint32_t index, uint32_t value,
unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_DefineElement(JSContext* cx, JS::HandleObject obj, uint32_t index, double value,
unsigned attrs);
/**
* Compute the expression `id in obj`.
*
* If obj has an own or inherited property obj[id], set *foundp = true and
* return true. If not, set *foundp = false and return true. On error, return
* false with an exception pending.
*
* Implements: ES6 [[Has]] internal method.
*/
extern JS_PUBLIC_API(bool)
JS_HasPropertyById(JSContext* cx, JS::HandleObject obj, JS::HandleId id, bool* foundp);
extern JS_PUBLIC_API(bool)
JS_HasProperty(JSContext* cx, JS::HandleObject obj, const char* name, bool* foundp);
extern JS_PUBLIC_API(bool)
JS_HasUCProperty(JSContext* cx, JS::HandleObject obj, const char16_t* name, size_t namelen,
bool* vp);
extern JS_PUBLIC_API(bool)
JS_HasElement(JSContext* cx, JS::HandleObject obj, uint32_t index, bool* foundp);
/**
* Determine whether obj has an own property with the key `id`.
*
* Implements: ES6 7.3.11 HasOwnProperty(O, P).
*/
extern JS_PUBLIC_API(bool)
JS_HasOwnPropertyById(JSContext* cx, JS::HandleObject obj, JS::HandleId id, bool* foundp);
extern JS_PUBLIC_API(bool)
JS_HasOwnProperty(JSContext* cx, JS::HandleObject obj, const char* name, bool* foundp);
/**
* Get the value of the property `obj[id]`, or undefined if no such property
* exists. This is the C++ equivalent of `vp = Reflect.get(obj, id, receiver)`.
*
* Most callers don't need the `receiver` argument. Consider using
* JS_GetProperty instead. (But if you're implementing a proxy handler's set()
* method, it's often correct to call this function and pass the receiver
* through.)
*
* Implements: ES6 [[Get]] internal method.
*/
extern JS_PUBLIC_API(bool)
JS_ForwardGetPropertyTo(JSContext* cx, JS::HandleObject obj, JS::HandleId id,
JS::HandleValue receiver, JS::MutableHandleValue vp);
extern JS_PUBLIC_API(bool)
JS_ForwardGetElementTo(JSContext* cx, JS::HandleObject obj, uint32_t index,
JS::HandleObject receiver, JS::MutableHandleValue vp);
/**
* Get the value of the property `obj[id]`, or undefined if no such property
* exists. The result is stored in vp.
*
* Implements: ES6 7.3.1 Get(O, P).
*/
extern JS_PUBLIC_API(bool)
JS_GetPropertyById(JSContext* cx, JS::HandleObject obj, JS::HandleId id,
JS::MutableHandleValue vp);
extern JS_PUBLIC_API(bool)
JS_GetProperty(JSContext* cx, JS::HandleObject obj, const char* name, JS::MutableHandleValue vp);
extern JS_PUBLIC_API(bool)
JS_GetUCProperty(JSContext* cx, JS::HandleObject obj, const char16_t* name, size_t namelen,
JS::MutableHandleValue vp);
extern JS_PUBLIC_API(bool)
JS_GetElement(JSContext* cx, JS::HandleObject obj, uint32_t index, JS::MutableHandleValue vp);
/**
* Perform the same property assignment as `Reflect.set(obj, id, v, receiver)`.
*
* This function has a `receiver` argument that most callers don't need.
* Consider using JS_SetProperty instead.
*
* Implements: ES6 [[Set]] internal method.
*/
extern JS_PUBLIC_API(bool)
JS_ForwardSetPropertyTo(JSContext* cx, JS::HandleObject obj, JS::HandleId id, JS::HandleValue v,
JS::HandleValue receiver, JS::ObjectOpResult& result);
/**
* Perform the assignment `obj[id] = v`.
*
* This function performs non-strict assignment, so if the property is
* read-only, nothing happens and no error is thrown.
*/
extern JS_PUBLIC_API(bool)
JS_SetPropertyById(JSContext* cx, JS::HandleObject obj, JS::HandleId id, JS::HandleValue v);
extern JS_PUBLIC_API(bool)
JS_SetProperty(JSContext* cx, JS::HandleObject obj, const char* name, JS::HandleValue v);
extern JS_PUBLIC_API(bool)
JS_SetUCProperty(JSContext* cx, JS::HandleObject obj, const char16_t* name, size_t namelen,
JS::HandleValue v);
extern JS_PUBLIC_API(bool)
JS_SetElement(JSContext* cx, JS::HandleObject obj, uint32_t index, JS::HandleValue v);
extern JS_PUBLIC_API(bool)
JS_SetElement(JSContext* cx, JS::HandleObject obj, uint32_t index, JS::HandleObject v);
extern JS_PUBLIC_API(bool)
JS_SetElement(JSContext* cx, JS::HandleObject obj, uint32_t index, JS::HandleString v);
extern JS_PUBLIC_API(bool)
JS_SetElement(JSContext* cx, JS::HandleObject obj, uint32_t index, int32_t v);
extern JS_PUBLIC_API(bool)
JS_SetElement(JSContext* cx, JS::HandleObject obj, uint32_t index, uint32_t v);
extern JS_PUBLIC_API(bool)
JS_SetElement(JSContext* cx, JS::HandleObject obj, uint32_t index, double v);
/**
* Delete a property. This is the C++ equivalent of
* `result = Reflect.deleteProperty(obj, id)`.
*
* This function has a `result` out parameter that most callers don't need.
* Unless you can pass through an ObjectOpResult provided by your caller, it's
* probably best to use the JS_DeletePropertyById signature with just 3
* arguments.
*
* Implements: ES6 [[Delete]] internal method.
*/
extern JS_PUBLIC_API(bool)
JS_DeletePropertyById(JSContext* cx, JS::HandleObject obj, JS::HandleId id,
JS::ObjectOpResult& result);
extern JS_PUBLIC_API(bool)
JS_DeleteProperty(JSContext* cx, JS::HandleObject obj, const char* name,
JS::ObjectOpResult& result);
extern JS_PUBLIC_API(bool)
JS_DeleteUCProperty(JSContext* cx, JS::HandleObject obj, const char16_t* name, size_t namelen,
JS::ObjectOpResult& result);
extern JS_PUBLIC_API(bool)
JS_DeleteElement(JSContext* cx, JS::HandleObject obj, uint32_t index, JS::ObjectOpResult& result);
/**
* Delete a property, ignoring strict failures. This is the C++ equivalent of
* the JS `delete obj[id]` in non-strict mode code.
*/
extern JS_PUBLIC_API(bool)
JS_DeletePropertyById(JSContext* cx, JS::HandleObject obj, jsid id);
extern JS_PUBLIC_API(bool)
JS_DeleteProperty(JSContext* cx, JS::HandleObject obj, const char* name);
extern JS_PUBLIC_API(bool)
JS_DeleteElement(JSContext* cx, JS::HandleObject obj, uint32_t index);
/**
* Get an array of the non-symbol enumerable properties of obj.
* This function is roughly equivalent to:
*
* var result = [];
* for (key in obj)
* result.push(key);
* return result;
*
* This is the closest thing we currently have to the ES6 [[Enumerate]]
* internal method.
*
* The array of ids returned by JS_Enumerate must be rooted to protect its
* contents from garbage collection. Use JS::Rooted<JS::IdVector>.
*/
extern JS_PUBLIC_API(bool)
JS_Enumerate(JSContext* cx, JS::HandleObject obj, JS::MutableHandle<JS::IdVector> props);
/*
* API for determining callability and constructability. [[Call]] and
* [[Construct]] are internal methods that aren't present on all objects, so it
* is useful to ask if they are there or not. The standard itself asks these
* questions routinely.
*/
namespace JS {
/**
* Return true if the given object is callable. In ES6 terms, an object is
* callable if it has a [[Call]] internal method.
*
* Implements: ES6 7.2.3 IsCallable(argument).
*
* Functions are callable. A scripted proxy or wrapper is callable if its
* target is callable. Most other objects aren't callable.
*/
extern JS_PUBLIC_API(bool)
IsCallable(JSObject* obj);
/**
* Return true if the given object is a constructor. In ES6 terms, an object is
* a constructor if it has a [[Construct]] internal method. The expression
* `new obj()` throws a TypeError if obj is not a constructor.
*
* Implements: ES6 7.2.4 IsConstructor(argument).
*
* JS functions and classes are constructors. Arrow functions and most builtin
* functions are not. A scripted proxy or wrapper is a constructor if its
* target is a constructor.
*/
extern JS_PUBLIC_API(bool)
IsConstructor(JSObject* obj);
} /* namespace JS */
/**
* Call a function, passing a this-value and arguments. This is the C++
* equivalent of `rval = Reflect.apply(fun, obj, args)`.
*
* Implements: ES6 7.3.12 Call(F, V, [argumentsList]).
* Use this function to invoke the [[Call]] internal method.
*/
extern JS_PUBLIC_API(bool)
JS_CallFunctionValue(JSContext* cx, JS::HandleObject obj, JS::HandleValue fval,
const JS::HandleValueArray& args, JS::MutableHandleValue rval);
extern JS_PUBLIC_API(bool)
JS_CallFunction(JSContext* cx, JS::HandleObject obj, JS::HandleFunction fun,
const JS::HandleValueArray& args, JS::MutableHandleValue rval);
/**
* Perform the method call `rval = obj[name](args)`.
*/
extern JS_PUBLIC_API(bool)
JS_CallFunctionName(JSContext* cx, JS::HandleObject obj, const char* name,
const JS::HandleValueArray& args, JS::MutableHandleValue rval);
namespace JS {
static inline bool
Call(JSContext* cx, JS::HandleObject thisObj, JS::HandleFunction fun,
const JS::HandleValueArray& args, MutableHandleValue rval)
{
return !!JS_CallFunction(cx, thisObj, fun, args, rval);
}
static inline bool
Call(JSContext* cx, JS::HandleObject thisObj, JS::HandleValue fun, const JS::HandleValueArray& args,
MutableHandleValue rval)
{
return !!JS_CallFunctionValue(cx, thisObj, fun, args, rval);
}
static inline bool
Call(JSContext* cx, JS::HandleObject thisObj, const char* name, const JS::HandleValueArray& args,
MutableHandleValue rval)
{
return !!JS_CallFunctionName(cx, thisObj, name, args, rval);
}
extern JS_PUBLIC_API(bool)
Call(JSContext* cx, JS::HandleValue thisv, JS::HandleValue fun, const JS::HandleValueArray& args,
MutableHandleValue rval);
static inline bool
Call(JSContext* cx, JS::HandleValue thisv, JS::HandleObject funObj, const JS::HandleValueArray& args,
MutableHandleValue rval)
{
MOZ_ASSERT(funObj);
JS::RootedValue fun(cx, JS::ObjectValue(*funObj));
return Call(cx, thisv, fun, args, rval);
}
/**
* Invoke a constructor. This is the C++ equivalent of
* `rval = Reflect.construct(fun, args, newTarget)`.
*
* JS::Construct() takes a `newTarget` argument that most callers don't need.
* Consider using the four-argument Construct signature instead. (But if you're
* implementing a subclass or a proxy handler's construct() method, this is the
* right function to call.)
*
* Implements: ES6 7.3.13 Construct(F, [argumentsList], [newTarget]).
* Use this function to invoke the [[Construct]] internal method.
*/
extern JS_PUBLIC_API(bool)
Construct(JSContext* cx, JS::HandleValue fun, HandleObject newTarget,
const JS::HandleValueArray &args, MutableHandleObject objp);
/**
* Invoke a constructor. This is the C++ equivalent of
* `rval = new fun(...args)`.
*
* Implements: ES6 7.3.13 Construct(F, [argumentsList], [newTarget]), when
* newTarget is omitted.
*/
extern JS_PUBLIC_API(bool)
Construct(JSContext* cx, JS::HandleValue fun, const JS::HandleValueArray& args,
MutableHandleObject objp);
} /* namespace JS */
/**
* Invoke a constructor, like the JS expression `new ctor(...args)`. Returns
* the new object, or null on error.
*/
extern JS_PUBLIC_API(JSObject*)
JS_New(JSContext* cx, JS::HandleObject ctor, const JS::HandleValueArray& args);
/*** Other property-defining functions ***********************************************************/
extern JS_PUBLIC_API(JSObject*)
JS_DefineObject(JSContext* cx, JS::HandleObject obj, const char* name,
const JSClass* clasp = nullptr, unsigned attrs = 0);
extern JS_PUBLIC_API(bool)
JS_DefineConstDoubles(JSContext* cx, JS::HandleObject obj, const JSConstDoubleSpec* cds);
extern JS_PUBLIC_API(bool)
JS_DefineConstIntegers(JSContext* cx, JS::HandleObject obj, const JSConstIntegerSpec* cis);
extern JS_PUBLIC_API(bool)
JS_DefineProperties(JSContext* cx, JS::HandleObject obj, const JSPropertySpec* ps);
/* * */
extern JS_PUBLIC_API(bool)
JS_AlreadyHasOwnPropertyById(JSContext* cx, JS::HandleObject obj, JS::HandleId id,
bool* foundp);
extern JS_PUBLIC_API(bool)
JS_AlreadyHasOwnProperty(JSContext* cx, JS::HandleObject obj, const char* name,
bool* foundp);
extern JS_PUBLIC_API(bool)
JS_AlreadyHasOwnUCProperty(JSContext* cx, JS::HandleObject obj, const char16_t* name,
size_t namelen, bool* foundp);
extern JS_PUBLIC_API(bool)
JS_AlreadyHasOwnElement(JSContext* cx, JS::HandleObject obj, uint32_t index, bool* foundp);
extern JS_PUBLIC_API(JSObject*)
JS_NewArrayObject(JSContext* cx, const JS::HandleValueArray& contents);
extern JS_PUBLIC_API(JSObject*)
JS_NewArrayObject(JSContext* cx, size_t length);
/**
* Returns true and sets |*isArray| indicating whether |value| is an Array
* object or a wrapper around one, otherwise returns false on failure.
*
* This method returns true with |*isArray == false| when passed a proxy whose
* target is an Array, or when passed a revoked proxy.
*/
extern JS_PUBLIC_API(bool)
JS_IsArrayObject(JSContext* cx, JS::HandleValue value, bool* isArray);
/**
* Returns true and sets |*isArray| indicating whether |obj| is an Array object
* or a wrapper around one, otherwise returns false on failure.
*
* This method returns true with |*isArray == false| when passed a proxy whose
* target is an Array, or when passed a revoked proxy.
*/
extern JS_PUBLIC_API(bool)
JS_IsArrayObject(JSContext* cx, JS::HandleObject obj, bool* isArray);
extern JS_PUBLIC_API(bool)
JS_GetArrayLength(JSContext* cx, JS::Handle<JSObject*> obj, uint32_t* lengthp);
extern JS_PUBLIC_API(bool)
JS_SetArrayLength(JSContext* cx, JS::Handle<JSObject*> obj, uint32_t length);
namespace JS {
/**
* Returns true and sets |*isMap| indicating whether |obj| is an Map object
* or a wrapper around one, otherwise returns false on failure.
*
* This method returns true with |*isMap == false| when passed a proxy whose
* target is an Map, or when passed a revoked proxy.
*/
extern JS_PUBLIC_API(bool)
IsMapObject(JSContext* cx, JS::HandleObject obj, bool* isMap);
/**
* Returns true and sets |*isSet| indicating whether |obj| is an Set object
* or a wrapper around one, otherwise returns false on failure.
*
* This method returns true with |*isSet == false| when passed a proxy whose
* target is an Set, or when passed a revoked proxy.
*/
extern JS_PUBLIC_API(bool)
IsSetObject(JSContext* cx, JS::HandleObject obj, bool* isSet);
} /* namespace JS */
/**
* Assign 'undefined' to all of the object's non-reserved slots. Note: this is
* done for all slots, regardless of the associated property descriptor.
*/
JS_PUBLIC_API(void)
JS_SetAllNonReservedSlotsToUndefined(JSContext* cx, JSObject* objArg);
/**
* Create a new array buffer with the given contents. It must be legal to pass
* these contents to free(). On success, the ownership is transferred to the
* new array buffer.
*/
extern JS_PUBLIC_API(JSObject*)
JS_NewArrayBufferWithContents(JSContext* cx, size_t nbytes, void* contents);
namespace JS {
using BufferContentsFreeFunc = void (*)(void* contents, void* userData);
} /* namespace JS */
/**
* Create a new array buffer with the given contents. The contents must not be
* modified by any other code, internal or external.
*
* When the array buffer is ready to be disposed of, `freeFunc(contents,
* freeUserData)` will be called to release the array buffer's reference on the
* contents.
*
* `freeFunc()` must not call any JSAPI functions that could cause a garbage
* collection.
*
* The caller must keep the buffer alive until `freeFunc()` is called, or, if
* `freeFunc` is null, until the JSRuntime is destroyed.
*
* The caller must not access the buffer on other threads. The JS engine will
* not allow the buffer to be transferred to other threads. If you try to
* transfer an external ArrayBuffer to another thread, the data is copied to a
* new malloc buffer. `freeFunc()` must be threadsafe, and may be called from
* any thread.
*
* This allows array buffers to be used with embedder objects that use reference
* counting, for example. In that case the caller is responsible
* for incrementing the reference count before passing the contents to this
* function. This also allows using non-reference-counted contents that must be
* freed with some function other than free().
*/
extern JS_PUBLIC_API(JSObject*)
JS_NewExternalArrayBuffer(JSContext* cx, size_t nbytes, void* contents,
JS::BufferContentsFreeFunc freeFunc, void* freeUserData = nullptr);
/**
* Create a new array buffer with the given contents. The array buffer does not take ownership of
* contents, and JS_DetachArrayBuffer must be called before the contents are disposed of.
*/
extern JS_PUBLIC_API(JSObject*)
JS_NewArrayBufferWithExternalContents(JSContext* cx, size_t nbytes, void* contents);
/**
* Steal the contents of the given array buffer. The array buffer has its
* length set to 0 and its contents array cleared. The caller takes ownership
* of the return value and must free it or transfer ownership via
* JS_NewArrayBufferWithContents when done using it.
*/
extern JS_PUBLIC_API(void*)
JS_StealArrayBufferContents(JSContext* cx, JS::HandleObject obj);
/**
* Returns a pointer to the ArrayBuffer |obj|'s data. |obj| and its views will store and expose
* the data in the returned pointer: assigning into the returned pointer will affect values exposed
* by views of |obj| and vice versa.
*
* The caller must ultimately deallocate the returned pointer to avoid leaking. The memory is
* *not* garbage-collected with |obj|. These steps must be followed to deallocate:
*
* 1. The ArrayBuffer |obj| must be detached using JS_DetachArrayBuffer.
* 2. The returned pointer must be freed using JS_free.
*
* To perform step 1, callers *must* hold a reference to |obj| until they finish using the returned
* pointer. They *must not* attempt to let |obj| be GC'd, then JS_free the pointer.
*
* If |obj| isn't an ArrayBuffer, this function returns null and reports an error.
*/
extern JS_PUBLIC_API(void*)
JS_ExternalizeArrayBufferContents(JSContext* cx, JS::HandleObject obj);
/**
* Create a new mapped array buffer with the given memory mapped contents. It
* must be legal to free the contents pointer by unmapping it. On success,
* ownership is transferred to the new mapped array buffer.
*/
extern JS_PUBLIC_API(JSObject*)
JS_NewMappedArrayBufferWithContents(JSContext* cx, size_t nbytes, void* contents);
/**
* Create memory mapped array buffer contents.
* Caller must take care of closing fd after calling this function.
*/
extern JS_PUBLIC_API(void*)
JS_CreateMappedArrayBufferContents(int fd, size_t offset, size_t length);
/**
* Release the allocated resource of mapped array buffer contents before the
* object is created.
* If a new object has been created by JS_NewMappedArrayBufferWithContents()
* with this content, then JS_DetachArrayBuffer() should be used instead to
* release the resource used by the object.
*/
extern JS_PUBLIC_API(void)
JS_ReleaseMappedArrayBufferContents(void* contents, size_t length);
extern JS_PUBLIC_API(JS::Value)
JS_GetReservedSlot(JSObject* obj, uint32_t index);
extern JS_PUBLIC_API(void)
JS_SetReservedSlot(JSObject* obj, uint32_t index, const JS::Value& v);
/************************************************************************/
/*
* Functions and scripts.
*/
extern JS_PUBLIC_API(JSFunction*)
JS_NewFunction(JSContext* cx, JSNative call, unsigned nargs, unsigned flags,
const char* name);
namespace JS {
extern JS_PUBLIC_API(JSFunction*)
GetSelfHostedFunction(JSContext* cx, const char* selfHostedName, HandleId id,
unsigned nargs);
/**
* Create a new function based on the given JSFunctionSpec, *fs.
* id is the result of a successful call to
* `PropertySpecNameToPermanentId(cx, fs->name, &id)`.
*
* Unlike JS_DefineFunctions, this does not treat fs as an array.
* *fs must not be JS_FS_END.
*/
extern JS_PUBLIC_API(JSFunction*)
NewFunctionFromSpec(JSContext* cx, const JSFunctionSpec* fs, HandleId id);
} /* namespace JS */
extern JS_PUBLIC_API(JSObject*)
JS_GetFunctionObject(JSFunction* fun);
/**
* Return the function's identifier as a JSString, or null if fun is unnamed.
* The returned string lives as long as fun, so you don't need to root a saved
* reference to it if fun is well-connected or rooted, and provided you bound
* the use of the saved reference by fun's lifetime.
*/
extern JS_PUBLIC_API(JSString*)
JS_GetFunctionId(JSFunction* fun);
/**
* Return a function's display name. This is the defined name if one was given
* where the function was defined, or it could be an inferred name by the JS
* engine in the case that the function was defined to be anonymous. This can
* still return nullptr if a useful display name could not be inferred. The
* same restrictions on rooting as those in JS_GetFunctionId apply.
*/
extern JS_PUBLIC_API(JSString*)
JS_GetFunctionDisplayId(JSFunction* fun);
/*
* Return the arity of fun, which includes default parameters and rest
* parameter. This can be used as `nargs` parameter for other functions.
*/
extern JS_PUBLIC_API(uint16_t)
JS_GetFunctionArity(JSFunction* fun);
/*
* Return the length of fun, which is the original value of .length property.
*/
JS_PUBLIC_API(bool)
JS_GetFunctionLength(JSContext* cx, JS::HandleFunction fun, uint16_t* length);
/**
* Infallible predicate to test whether obj is a function object (faster than
* comparing obj's class name to "Function", but equivalent unless someone has
* overwritten the "Function" identifier with a different constructor and then
* created instances using that constructor that might be passed in as obj).
*/
extern JS_PUBLIC_API(bool)
JS_ObjectIsFunction(JSContext* cx, JSObject* obj);
extern JS_PUBLIC_API(bool)
JS_IsNativeFunction(JSObject* funobj, JSNative call);
/** Return whether the given function is a valid constructor. */
extern JS_PUBLIC_API(bool)
JS_IsConstructor(JSFunction* fun);
extern JS_PUBLIC_API(bool)
JS_DefineFunctions(JSContext* cx, JS::Handle<JSObject*> obj, const JSFunctionSpec* fs);
extern JS_PUBLIC_API(JSFunction*)
JS_DefineFunction(JSContext* cx, JS::Handle<JSObject*> obj, const char* name, JSNative call,
unsigned nargs, unsigned attrs);
extern JS_PUBLIC_API(JSFunction*)
JS_DefineUCFunction(JSContext* cx, JS::Handle<JSObject*> obj,
const char16_t* name, size_t namelen, JSNative call,
unsigned nargs, unsigned attrs);
extern JS_PUBLIC_API(JSFunction*)
JS_DefineFunctionById(JSContext* cx, JS::Handle<JSObject*> obj, JS::Handle<jsid> id, JSNative call,
unsigned nargs, unsigned attrs);
extern JS_PUBLIC_API(bool)
JS_IsFunctionBound(JSFunction* fun);
extern JS_PUBLIC_API(JSObject*)
JS_GetBoundFunctionTarget(JSFunction* fun);
namespace JS {
/**
* Clone a top-level function into cx's global. This function will dynamically
* fail if funobj was lexically nested inside some other function.
*/
extern JS_PUBLIC_API(JSObject*)
CloneFunctionObject(JSContext* cx, HandleObject funobj);
/**
* As above, but providing an explicit scope chain. scopeChain must not include
* the global object on it; that's implicit. It needs to contain the other
* objects that should end up on the clone's scope chain.
*/
extern JS_PUBLIC_API(JSObject*)
CloneFunctionObject(JSContext* cx, HandleObject funobj, AutoObjectVector& scopeChain);
} // namespace JS
/**
* Given a buffer, return false if the buffer might become a valid
* javascript statement with the addition of more lines. Otherwise return
* true. The intent is to support interactive compilation - accumulate
* lines in a buffer until JS_BufferIsCompilableUnit is true, then pass it to
* the compiler.
*/
extern JS_PUBLIC_API(bool)
JS_BufferIsCompilableUnit(JSContext* cx, JS::Handle<JSObject*> obj, const char* utf8,
size_t length);
/**
* |script| will always be set. On failure, it will be set to nullptr.
*/
extern JS_PUBLIC_API(bool)
JS_CompileScript(JSContext* cx, const char* ascii, size_t length,
const JS::CompileOptions& options,
JS::MutableHandleScript script);
/**
* |script| will always be set. On failure, it will be set to nullptr.
*/
extern JS_PUBLIC_API(bool)
JS_CompileUCScript(JSContext* cx, JS::SourceBufferHolder& srcBuf,
const JS::CompileOptions& options,
JS::MutableHandleScript script);
extern JS_PUBLIC_API(JSObject*)
JS_GetGlobalFromScript(JSScript* script);
extern JS_PUBLIC_API(const char*)
JS_GetScriptFilename(JSScript* script);
extern JS_PUBLIC_API(unsigned)
JS_GetScriptBaseLineNumber(JSContext* cx, JSScript* script);
extern JS_PUBLIC_API(JSScript*)
JS_GetFunctionScript(JSContext* cx, JS::HandleFunction fun);
namespace JS {
/* Options for JavaScript compilation. */
/*
* In the most common use case, a CompileOptions instance is allocated on the
* stack, and holds non-owning references to non-POD option values: strings;
* principals; objects; and so on. The code declaring the instance guarantees
* that such option values will outlive the CompileOptions itself: objects are
* otherwise rooted; principals have had their reference counts bumped; strings
* will not be freed until the CompileOptions goes out of scope. In this
* situation, CompileOptions only refers to things others own, so it can be
* lightweight.
*
* In some cases, however, we need to hold compilation options with a
* non-stack-like lifetime. For example, JS::CompileOffThread needs to save
* compilation options where a worker thread can find them, and then return
* immediately. The worker thread will come along at some later point, and use
* the options.
*
* The compiler itself just needs to be able to access a collection of options;
* it doesn't care who owns them, or what's keeping them alive. It does its own
* addrefs/copies/tracing/etc.
*
* Furthermore, in some cases compile options are propagated from one entity to
* another (e.g. from a script to a function defined in that script). This
* involves copying over some, but not all, of the options.
*
* So, we have a class hierarchy that reflects these four use cases:
*
* - TransitiveCompileOptions is the common base class, representing options
* that should get propagated from a script to functions defined in that
* script. This is never instantiated directly.
*
* - ReadOnlyCompileOptions is the only subclass of TransitiveCompileOptions,
* representing a full set of compile options. It can be used by code that
* simply needs to access options set elsewhere, like the compiler. This,
* again, is never instantiated directly.
*
* - The usual CompileOptions class must be stack-allocated, and holds
* non-owning references to the filename, element, and so on. It's derived
* from ReadOnlyCompileOptions, so the compiler can use it.
*
* - OwningCompileOptions roots / copies / reference counts of all its values,
* and unroots / frees / releases them when it is destructed. It too is
* derived from ReadOnlyCompileOptions, so the compiler accepts it.
*/
enum class AsmJSOption : uint8_t { Enabled, Disabled, DisabledByDebugger };
/**
* The common base class for the CompileOptions hierarchy.
*
* Use this in code that needs to propagate compile options from one compilation
* unit to another.
*/
class JS_FRIEND_API(TransitiveCompileOptions)
{
protected:
// The Web Platform allows scripts to be loaded from arbitrary cross-origin
// sources. This allows an attack by which a malicious website loads a
// sensitive file (say, a bank statement) cross-origin (using the user's
// cookies), and sniffs the generated syntax errors (via a window.onerror
// handler) for juicy morsels of its contents.
//
// To counter this attack, HTML5 specifies that script errors should be
// sanitized ("muted") when the script is not same-origin with the global
// for which it is loaded. Callers should set this flag for cross-origin
// scripts, and it will be propagated appropriately to child scripts and
// passed back in JSErrorReports.
bool mutedErrors_;
const char* filename_;
const char* introducerFilename_;
const char16_t* sourceMapURL_;
TransitiveCompileOptions()
: mutedErrors_(false),
filename_(nullptr),
introducerFilename_(nullptr),
sourceMapURL_(nullptr),
utf8(false),
selfHostingMode(false),
canLazilyParse(true),
strictOption(false),
extraWarningsOption(false),
werrorOption(false),
asmJSOption(AsmJSOption::Disabled),
throwOnAsmJSValidationFailureOption(false),
forceAsync(false),
sourceIsLazy(false),
allowHTMLComments(true),
isProbablySystemCode(false),
hideScriptFromDebugger(false),
introductionType(nullptr),
introductionLineno(0),
introductionOffset(0),
hasIntroductionInfo(false)
{ }
// Set all POD options (those not requiring reference counts, copies,
// rooting, or other hand-holding) to their values in |rhs|.
void copyPODTransitiveOptions(const TransitiveCompileOptions& rhs);
public:
// Read-only accessors for non-POD options. The proper way to set these
// depends on the derived type.
bool mutedErrors() const { return mutedErrors_; }
const char* filename() const { return filename_; }
const char* introducerFilename() const { return introducerFilename_; }
const char16_t* sourceMapURL() const { return sourceMapURL_; }
virtual JSObject* element() const = 0;
virtual JSString* elementAttributeName() const = 0;
virtual JSScript* introductionScript() const = 0;
// POD options.
bool utf8;
bool selfHostingMode;
bool canLazilyParse;
bool strictOption;
bool extraWarningsOption;
bool werrorOption;
AsmJSOption asmJSOption;
bool throwOnAsmJSValidationFailureOption;
bool forceAsync;
bool sourceIsLazy;
bool allowHTMLComments;
bool isProbablySystemCode;
bool hideScriptFromDebugger;
// |introductionType| is a statically allocated C string:
// one of "eval", "Function", or "GeneratorFunction".
const char* introductionType;
unsigned introductionLineno;
uint32_t introductionOffset;
bool hasIntroductionInfo;
private:
void operator=(const TransitiveCompileOptions&) = delete;
};
/**
* The class representing a full set of compile options.
*
* Use this in code that only needs to access compilation options created
* elsewhere, like the compiler. Don't instantiate this class (the constructor
* is protected anyway); instead, create instances only of the derived classes:
* CompileOptions and OwningCompileOptions.
*/
class JS_FRIEND_API(ReadOnlyCompileOptions) : public TransitiveCompileOptions
{
friend class CompileOptions;
protected:
ReadOnlyCompileOptions()
: TransitiveCompileOptions(),
lineno(1),
column(0),
scriptSourceOffset(0),
isRunOnce(false),
nonSyntacticScope(false),
noScriptRval(false),
allowSyntaxParser(true)
{ }
// Set all POD options (those not requiring reference counts, copies,
// rooting, or other hand-holding) to their values in |rhs|.
void copyPODOptions(const ReadOnlyCompileOptions& rhs);
public:
// Read-only accessors for non-POD options. The proper way to set these
// depends on the derived type.
bool mutedErrors() const { return mutedErrors_; }
const char* filename() const { return filename_; }
const char* introducerFilename() const { return introducerFilename_; }
const char16_t* sourceMapURL() const { return sourceMapURL_; }
virtual JSObject* element() const override = 0;
virtual JSString* elementAttributeName() const override = 0;
virtual JSScript* introductionScript() const override = 0;
// POD options.
unsigned lineno;
unsigned column;
// The offset within the ScriptSource's full uncompressed text of the first
// character we're presenting for compilation with this CompileOptions.
//
// When we compile a LazyScript, we pass the compiler only the substring of
// the source the lazy function occupies. With chunked decompression, we
// may not even have the complete uncompressed source present in memory. But
// parse node positions are offsets within the ScriptSource's full text,
// and LazyScripts indicate their substring of the full source by its
// starting and ending offsets within the full text. This
// scriptSourceOffset field lets the frontend convert between these
// offsets and offsets within the substring presented for compilation.
unsigned scriptSourceOffset;
// isRunOnce only applies to non-function scripts.
bool isRunOnce;
bool nonSyntacticScope;
bool noScriptRval;
bool allowSyntaxParser;
private:
void operator=(const ReadOnlyCompileOptions&) = delete;
};
/**
* Compilation options, with dynamic lifetime. An instance of this type
* makes a copy of / holds / roots all dynamically allocated resources
* (principals; elements; strings) that it refers to. Its destructor frees
* / drops / unroots them. This is heavier than CompileOptions, below, but
* unlike CompileOptions, it can outlive any given stack frame.
*
* Note that this *roots* any JS values it refers to - they're live
* unconditionally. Thus, instances of this type can't be owned, directly
* or indirectly, by a JavaScript object: if any value that this roots ever
* comes to refer to the object that owns this, then the whole cycle, and
* anything else it entrains, will never be freed.
*/
class JS_FRIEND_API(OwningCompileOptions) : public ReadOnlyCompileOptions
{
PersistentRootedObject elementRoot;
PersistentRootedString elementAttributeNameRoot;
PersistentRootedScript introductionScriptRoot;
public:
// A minimal constructor, for use with OwningCompileOptions::copy.
explicit OwningCompileOptions(JSContext* cx);
~OwningCompileOptions();
JSObject* element() const override { return elementRoot; }
JSString* elementAttributeName() const override { return elementAttributeNameRoot; }
JSScript* introductionScript() const override { return introductionScriptRoot; }
// Set this to a copy of |rhs|. Return false on OOM.
bool copy(JSContext* cx, const ReadOnlyCompileOptions& rhs);
/* These setters make copies of their string arguments, and are fallible. */
bool setFile(JSContext* cx, const char* f);
bool setFileAndLine(JSContext* cx, const char* f, unsigned l);
bool setSourceMapURL(JSContext* cx, const char16_t* s);
bool setIntroducerFilename(JSContext* cx, const char* s);
/* These setters are infallible, and can be chained. */
OwningCompileOptions& setLine(unsigned l) { lineno = l; return *this; }
OwningCompileOptions& setElement(JSObject* e) {
elementRoot = e;
return *this;
}
OwningCompileOptions& setElementAttributeName(JSString* p) {
elementAttributeNameRoot = p;
return *this;
}
OwningCompileOptions& setIntroductionScript(JSScript* s) {
introductionScriptRoot = s;
return *this;
}
OwningCompileOptions& setMutedErrors(bool mute) {
mutedErrors_ = mute;
return *this;
}
OwningCompileOptions& setUTF8(bool u) { utf8 = u; return *this; }
OwningCompileOptions& setColumn(unsigned c) { column = c; return *this; }
OwningCompileOptions& setScriptSourceOffset(unsigned o) { scriptSourceOffset = o; return *this; }
OwningCompileOptions& setIsRunOnce(bool once) { isRunOnce = once; return *this; }
OwningCompileOptions& setNoScriptRval(bool nsr) { noScriptRval = nsr; return *this; }
OwningCompileOptions& setSelfHostingMode(bool shm) { selfHostingMode = shm; return *this; }
OwningCompileOptions& setCanLazilyParse(bool clp) { canLazilyParse = clp; return *this; }
OwningCompileOptions& setAllowSyntaxParser(bool clp) { allowSyntaxParser = clp; return *this; }
OwningCompileOptions& setSourceIsLazy(bool l) { sourceIsLazy = l; return *this; }
OwningCompileOptions& setNonSyntacticScope(bool n) { nonSyntacticScope = n; return *this; }
OwningCompileOptions& setIntroductionType(const char* t) { introductionType = t; return *this; }
bool setIntroductionInfo(JSContext* cx, const char* introducerFn, const char* intro,
unsigned line, JSScript* script, uint32_t offset)
{
if (!setIntroducerFilename(cx, introducerFn))
return false;
introductionType = intro;
introductionLineno = line;
introductionScriptRoot = script;
introductionOffset = offset;
hasIntroductionInfo = true;
return true;
}
size_t sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
private:
void operator=(const CompileOptions& rhs) = delete;
};
/**
* Compilation options stored on the stack. An instance of this type
* simply holds references to dynamically allocated resources (element;
* filename; source map URL) that are owned by something else. If you
* create an instance of this type, it's up to you to guarantee that
* everything you store in it will outlive it.
*/
class MOZ_STACK_CLASS JS_FRIEND_API(CompileOptions) final : public ReadOnlyCompileOptions
{
RootedObject elementRoot;
RootedString elementAttributeNameRoot;
RootedScript introductionScriptRoot;
public:
explicit CompileOptions(JSContext* cx);
CompileOptions(JSContext* cx, const ReadOnlyCompileOptions& rhs)
: ReadOnlyCompileOptions(), elementRoot(cx), elementAttributeNameRoot(cx),
introductionScriptRoot(cx)
{
copyPODOptions(rhs);
filename_ = rhs.filename();
introducerFilename_ = rhs.introducerFilename();
sourceMapURL_ = rhs.sourceMapURL();
elementRoot = rhs.element();
elementAttributeNameRoot = rhs.elementAttributeName();
introductionScriptRoot = rhs.introductionScript();
}
CompileOptions(JSContext* cx, const TransitiveCompileOptions& rhs)
: ReadOnlyCompileOptions(), elementRoot(cx), elementAttributeNameRoot(cx),
introductionScriptRoot(cx)
{
copyPODTransitiveOptions(rhs);
filename_ = rhs.filename();
introducerFilename_ = rhs.introducerFilename();
sourceMapURL_ = rhs.sourceMapURL();
elementRoot = rhs.element();
elementAttributeNameRoot = rhs.elementAttributeName();
introductionScriptRoot = rhs.introductionScript();
}
JSObject* element() const override { return elementRoot; }
JSString* elementAttributeName() const override { return elementAttributeNameRoot; }
JSScript* introductionScript() const override { return introductionScriptRoot; }
CompileOptions& setFile(const char* f) { filename_ = f; return *this; }
CompileOptions& setLine(unsigned l) { lineno = l; return *this; }
CompileOptions& setFileAndLine(const char* f, unsigned l) {
filename_ = f; lineno = l; return *this;
}
CompileOptions& setSourceMapURL(const char16_t* s) { sourceMapURL_ = s; return *this; }
CompileOptions& setElement(JSObject* e) { elementRoot = e; return *this; }
CompileOptions& setElementAttributeName(JSString* p) {
elementAttributeNameRoot = p;
return *this;
}
CompileOptions& setIntroductionScript(JSScript* s) {
introductionScriptRoot = s;
return *this;
}
CompileOptions& setMutedErrors(bool mute) {
mutedErrors_ = mute;
return *this;
}
CompileOptions& setUTF8(bool u) { utf8 = u; return *this; }
CompileOptions& setColumn(unsigned c) { column = c; return *this; }
CompileOptions& setScriptSourceOffset(unsigned o) { scriptSourceOffset = o; return *this; }
CompileOptions& setIsRunOnce(bool once) { isRunOnce = once; return *this; }
CompileOptions& setNoScriptRval(bool nsr) { noScriptRval = nsr; return *this; }
CompileOptions& setSelfHostingMode(bool shm) { selfHostingMode = shm; return *this; }
CompileOptions& setCanLazilyParse(bool clp) { canLazilyParse = clp; return *this; }
CompileOptions& setAllowSyntaxParser(bool clp) { allowSyntaxParser = clp; return *this; }
CompileOptions& setSourceIsLazy(bool l) { sourceIsLazy = l; return *this; }
CompileOptions& setNonSyntacticScope(bool n) { nonSyntacticScope = n; return *this; }
CompileOptions& setIntroductionType(const char* t) { introductionType = t; return *this; }
CompileOptions& setIntroductionInfo(const char* introducerFn, const char* intro,
unsigned line, JSScript* script, uint32_t offset)
{
introducerFilename_ = introducerFn;
introductionType = intro;
introductionLineno = line;
introductionScriptRoot = script;
introductionOffset = offset;
hasIntroductionInfo = true;
return *this;
}
CompileOptions& maybeMakeStrictMode(bool strict) {
strictOption = strictOption || strict;
return *this;
}
private:
void operator=(const CompileOptions& rhs) = delete;
};
/**
* |script| will always be set. On failure, it will be set to nullptr.
*/
extern JS_PUBLIC_API(bool)
Compile(JSContext* cx, const ReadOnlyCompileOptions& options,
SourceBufferHolder& srcBuf, JS::MutableHandleScript script);
extern JS_PUBLIC_API(bool)
Compile(JSContext* cx, const ReadOnlyCompileOptions& options,
const char* bytes, size_t length, JS::MutableHandleScript script);
extern JS_PUBLIC_API(bool)
Compile(JSContext* cx, const ReadOnlyCompileOptions& options,
FILE* file, JS::MutableHandleScript script);
extern JS_PUBLIC_API(bool)
Compile(JSContext* cx, const ReadOnlyCompileOptions& options,
const char* filename, JS::MutableHandleScript script);
extern JS_PUBLIC_API(bool)
CompileForNonSyntacticScope(JSContext* cx, const ReadOnlyCompileOptions& options,
SourceBufferHolder& srcBuf, JS::MutableHandleScript script);
extern JS_PUBLIC_API(bool)
CompileForNonSyntacticScope(JSContext* cx, const ReadOnlyCompileOptions& options,
const char* bytes, size_t length, JS::MutableHandleScript script);
extern JS_PUBLIC_API(bool)
CompileForNonSyntacticScope(JSContext* cx, const ReadOnlyCompileOptions& options,
FILE* file, JS::MutableHandleScript script);
extern JS_PUBLIC_API(bool)
CompileForNonSyntacticScope(JSContext* cx, const ReadOnlyCompileOptions& options,
const char* filename, JS::MutableHandleScript script);
extern JS_PUBLIC_API(bool)
CanCompileOffThread(JSContext* cx, const ReadOnlyCompileOptions& options, size_t length);
extern JS_PUBLIC_API(bool)
CanDecodeOffThread(JSContext* cx, const ReadOnlyCompileOptions& options, size_t length);
/*
* Off thread compilation control flow.
*
* After successfully triggering an off thread compile of a script, the
* callback will eventually be invoked with the specified data and a token
* for the compilation. The callback will be invoked while off thread,
* so must ensure that its operations are thread safe. Afterwards, one of the
* following functions must be invoked on the runtime's main thread:
*
* - FinishOffThreadScript, to get the result script (or nullptr on failure).
* - CancelOffThreadScript, to free the resources without creating a script.
*
* The characters passed in to CompileOffThread must remain live until the
* callback is invoked, and the resulting script will be rooted until the call
* to FinishOffThreadScript.
*/
extern JS_PUBLIC_API(bool)
CompileOffThread(JSContext* cx, const ReadOnlyCompileOptions& options,
JS::SourceBufferHolder& srcBuf,
OffThreadCompileCallback callback, void* callbackData);
extern JS_PUBLIC_API(JSScript*)
FinishOffThreadScript(JSContext* cx, OffThreadToken* token);
extern JS_PUBLIC_API(void)
CancelOffThreadScript(JSContext* cx, OffThreadToken* token);
extern JS_PUBLIC_API(bool)
CompileOffThreadModule(JSContext* cx, const ReadOnlyCompileOptions& options,
JS::SourceBufferHolder& srcBuf,
OffThreadCompileCallback callback, void* callbackData);
extern JS_PUBLIC_API(JSScript*)
FinishOffThreadModule(JSContext* cx, OffThreadToken* token);
extern JS_PUBLIC_API(void)
CancelOffThreadModule(JSContext* cx, OffThreadToken* token);
extern JS_PUBLIC_API(bool)
DecodeOffThreadScript(JSContext* cx, const ReadOnlyCompileOptions& options,
mozilla::Vector<uint8_t>& buffer /* TranscodeBuffer& */, size_t cursor,
OffThreadCompileCallback callback, void* callbackData);
extern JS_PUBLIC_API(bool)
DecodeOffThreadScript(JSContext* cx, const ReadOnlyCompileOptions& options,
const mozilla::Range<uint8_t>& range /* TranscodeRange& */,
OffThreadCompileCallback callback, void* callbackData);
extern JS_PUBLIC_API(JSScript*)
FinishOffThreadScriptDecoder(JSContext* cx, OffThreadToken* token);
extern JS_PUBLIC_API(void)
CancelOffThreadScriptDecoder(JSContext* cx, OffThreadToken* token);
extern JS_PUBLIC_API(bool)
DecodeMultiOffThreadScripts(JSContext* cx, const ReadOnlyCompileOptions& options,
mozilla::Vector<TranscodeSource>& sources,
OffThreadCompileCallback callback, void* callbackData);
extern JS_PUBLIC_API(bool)
FinishMultiOffThreadScriptsDecoder(JSContext* cx, OffThreadToken* token,
JS::MutableHandle<JS::ScriptVector> scripts);
extern JS_PUBLIC_API(void)
CancelMultiOffThreadScriptsDecoder(JSContext* cx, OffThreadToken* token);
/**
* Compile a function with envChain plus the global as its scope chain.
* envChain must contain objects in the current compartment of cx. The actual
* scope chain used for the function will consist of With wrappers for those
* objects, followed by the current global of the compartment cx is in. This
* global must not be explicitly included in the scope chain.
*/
extern JS_PUBLIC_API(bool)
CompileFunction(JSContext* cx, AutoObjectVector& envChain,
const ReadOnlyCompileOptions& options,
const char* name, unsigned nargs, const char* const* argnames,
SourceBufferHolder& srcBuf, JS::MutableHandleFunction fun);
/**
* Same as above, but taking a const char * for the function body.
*/
extern JS_PUBLIC_API(bool)
CompileFunction(JSContext* cx, AutoObjectVector& envChain,
const ReadOnlyCompileOptions& options,
const char* name, unsigned nargs, const char* const* argnames,
const char* bytes, size_t length, JS::MutableHandleFunction fun);
/*
* Associate an element wrapper and attribute name with a previously compiled
* script, for debugging purposes. Calling this function is optional, but should
* be done before script execution if it is required.
*/
extern JS_PUBLIC_API(bool)
InitScriptSourceElement(JSContext* cx, HandleScript script,
HandleObject element, HandleString elementAttrName = nullptr);
/*
* For a script compiled with the hideScriptFromDebugger option, expose the
* script to the debugger by calling the debugger's onNewScript hook.
*/
extern JS_PUBLIC_API(void)
ExposeScriptToDebugger(JSContext* cx, HandleScript script);
} /* namespace JS */
extern JS_PUBLIC_API(JSString*)
JS_DecompileScript(JSContext* cx, JS::Handle<JSScript*> script);
extern JS_PUBLIC_API(JSString*)
JS_DecompileFunction(JSContext* cx, JS::Handle<JSFunction*> fun);
/*
* NB: JS_ExecuteScript and the JS::Evaluate APIs come in two flavors: either
* they use the global as the scope, or they take an AutoObjectVector of objects
* to use as the scope chain. In the former case, the global is also used as
* the "this" keyword value and the variables object (ECMA parlance for where
* 'var' and 'function' bind names) of the execution context for script. In the
* latter case, the first object in the provided list is used, unless the list
* is empty, in which case the global is used.
*
* Why a runtime option? The alternative is to add APIs duplicating those
* for the other value of flags, and that doesn't seem worth the code bloat
* cost. Such new entry points would probably have less obvious names, too, so
* would not tend to be used. The ContextOptionsRef adjustment, OTOH, can be
* more easily hacked into existing code that does not depend on the bug; such
* code can continue to use the familiar JS::Evaluate, etc., entry points.
*/
/**
* Evaluate a script in the scope of the current global of cx.
*/
extern JS_PUBLIC_API(bool)
JS_ExecuteScript(JSContext* cx, JS::HandleScript script, JS::MutableHandleValue rval);
extern JS_PUBLIC_API(bool)
JS_ExecuteScript(JSContext* cx, JS::HandleScript script);
/**
* As above, but providing an explicit scope chain. envChain must not include
* the global object on it; that's implicit. It needs to contain the other
* objects that should end up on the script's scope chain.
*/
extern JS_PUBLIC_API(bool)
JS_ExecuteScript(JSContext* cx, JS::AutoObjectVector& envChain,
JS::HandleScript script, JS::MutableHandleValue rval);
extern JS_PUBLIC_API(bool)
JS_ExecuteScript(JSContext* cx, JS::AutoObjectVector& envChain, JS::HandleScript script);
namespace JS {
/**
* Like the above, but handles a cross-compartment script. If the script is
* cross-compartment, it is cloned into the current compartment before executing.
*/
extern JS_PUBLIC_API(bool)
CloneAndExecuteScript(JSContext* cx, JS::Handle<JSScript*> script,
JS::MutableHandleValue rval);
/**
* Like CloneAndExecuteScript above, but allows executing under a non-syntactic
* environment chain.
*/
extern JS_PUBLIC_API(bool)
CloneAndExecuteScript(JSContext* cx, JS::AutoObjectVector& envChain,
JS::Handle<JSScript*> script,
JS::MutableHandleValue rval);
} /* namespace JS */
namespace JS {
/**
* Evaluate the given source buffer in the scope of the current global of cx.
*/
extern JS_PUBLIC_API(bool)
Evaluate(JSContext* cx, const ReadOnlyCompileOptions& options,
SourceBufferHolder& srcBuf, JS::MutableHandleValue rval);
/**
* As above, but providing an explicit scope chain. envChain must not include
* the global object on it; that's implicit. It needs to contain the other
* objects that should end up on the script's scope chain.
*/
extern JS_PUBLIC_API(bool)
Evaluate(JSContext* cx, AutoObjectVector& envChain, const ReadOnlyCompileOptions& options,
SourceBufferHolder& srcBuf, JS::MutableHandleValue rval);
/**
* Evaluate the given byte buffer in the scope of the current global of cx.
*/
extern JS_PUBLIC_API(bool)
Evaluate(JSContext* cx, const ReadOnlyCompileOptions& options,
const char* bytes, size_t length, JS::MutableHandleValue rval);
/**
* Evaluate the given file in the scope of the current global of cx.
*/
extern JS_PUBLIC_API(bool)
Evaluate(JSContext* cx, const ReadOnlyCompileOptions& options,
const char* filename, JS::MutableHandleValue rval);
using ModuleResolveHook = JSScript* (*)(JSContext*, HandleScript, HandleString);
/**
* Get the HostResolveImportedModule hook for the runtime.
*/
extern JS_PUBLIC_API(ModuleResolveHook)
GetModuleResolveHook(JSRuntime* rt);
/**
* Set the HostResolveImportedModule hook for the runtime to the given function.
*/
extern JS_PUBLIC_API(void)
SetModuleResolveHook(JSRuntime* rt, ModuleResolveHook func);
using ModuleMetadataHook = bool (*)(JSContext*, HandleScript, HandleObject);
/**
* Get the hook for populating the import.meta metadata object.
*/
extern JS_PUBLIC_API(ModuleMetadataHook)
GetModuleMetadataHook(JSRuntime* rt);
/**
* Set the hook for populating the import.meta metadata object to the given
* function.
*/
extern JS_PUBLIC_API(void)
SetModuleMetadataHook(JSRuntime* rt, ModuleMetadataHook func);
/**
* Parse the given source buffer as a module in the scope of the current global
* of cx.
*/
extern JS_PUBLIC_API(bool)
CompileModule(JSContext* cx, const ReadOnlyCompileOptions& options,
SourceBufferHolder& srcBuf, JS::MutableHandleScript script);
/**
* Set the [[HostDefined]] field of a classic script or module script.
*/
extern JS_PUBLIC_API(void)
SetTopLevelScriptPrivate(JSScript* script, void* value);
/**
* Get the [[HostDefined]] field of a classic script or module script.
*/
extern JS_PUBLIC_API(void*)
GetTopLevelScriptPrivate(JSScript* script);
/*
* Perform the ModuleInstantiate operation on the given source text module
* record.
*
* This transitively resolves all module dependencies (calling the
* HostResolveImportedModule hook) and initializes the environment record for
* the module.
*/
extern JS_PUBLIC_API(bool)
ModuleInstantiate(JSContext* cx, JS::HandleScript script);
/*
* Perform the ModuleEvaluate operation on the given source text module record.
*
* This does nothing if this module has already been evaluated. Otherwise, it
* transitively evaluates all dependences of this module and then evaluates this
* module.
*
* ModuleInstantiate must have completed prior to calling this.
*/
extern JS_PUBLIC_API(bool)
ModuleEvaluate(JSContext* cx, JS::HandleScript script);
/*
* Get a list of the module specifiers used by a source text module
* record to request importation of modules.
*
* The result is a JavaScript array of object values. To extract the individual
* values use only JS_GetArrayLength and JS_GetElement with indices 0 to length
* - 1.
*
* The element values are objects with the following properties:
* - moduleSpecifier: the module specifier string
* - lineNumber: the line number of the import in the source text
* - columnNumber: the column number of the import in the source text
*
* These property values can be extracted with GetRequestedModuleSpecifier() and
* GetRequestedModuleSourcePos()
*/
extern JS_PUBLIC_API(JSObject*)
GetRequestedModules(JSContext* cx, JS::HandleScript script);
extern JS_PUBLIC_API(JSString*)
GetRequestedModuleSpecifier(JSContext* cx, JS::HandleValue requestedModuleObject);
extern JS_PUBLIC_API(void)
GetRequestedModuleSourcePos(JSContext* cx, JS::HandleValue requestedModuleObject,
uint32_t* lineNumber, uint32_t* columnNumber);
} /* namespace JS */
#if defined(JS_BUILD_BINAST)
namespace JS {
extern JS_PUBLIC_API(JSScript*)
DecodeBinAST(JSContext* cx, const ReadOnlyCompileOptions& options,
FILE* file);
extern JS_PUBLIC_API(JSScript*)
DecodeBinAST(JSContext* cx, const ReadOnlyCompileOptions& options,
const uint8_t* buf, size_t length);
extern JS_PUBLIC_API(bool)
CanDecodeBinASTOffThread(JSContext* cx, const ReadOnlyCompileOptions& options, size_t length);
extern JS_PUBLIC_API(bool)
DecodeBinASTOffThread(JSContext* cx, const ReadOnlyCompileOptions& options,
const uint8_t* buf, size_t length,
OffThreadCompileCallback callback, void* callbackData);
extern JS_PUBLIC_API(JSScript*)
FinishOffThreadBinASTDecode(JSContext* cx, OffThreadToken* token);
} /* namespace JS */
#endif /* JS_BUILD_BINAST */
extern JS_PUBLIC_API(bool)
JS_CheckForInterrupt(JSContext* cx);
/*
* These functions allow setting an interrupt callback that will be called
* from the JS thread some time after any thread triggered the callback using
* JS_RequestInterruptCallback(cx).
*
* To schedule the GC and for other activities the engine internally triggers
* interrupt callbacks. The embedding should thus not rely on callbacks being
* triggered through the external API only.
*
* Important note: Additional callbacks can occur inside the callback handler
* if it re-enters the JS engine. The embedding must ensure that the callback
* is disconnected before attempting such re-entry.
*/
extern JS_PUBLIC_API(bool)
JS_AddInterruptCallback(JSContext* cx, JSInterruptCallback callback);
extern JS_PUBLIC_API(bool)
JS_DisableInterruptCallback(JSContext* cx);
extern JS_PUBLIC_API(void)
JS_ResetInterruptCallback(JSContext* cx, bool enable);
extern JS_PUBLIC_API(void)
JS_RequestInterruptCallback(JSContext* cx);
extern JS_PUBLIC_API(void)
JS_RequestInterruptCallbackCanWait(JSContext* cx);
namespace JS {
/**
* Sets the callback that's invoked whenever an incumbent global is required.
*
* SpiderMonkey doesn't itself have a notion of incumbent globals as defined
* by the html spec, so we need the embedding to provide this.
* See dom/base/ScriptSettings.h for details.
*/
extern JS_PUBLIC_API(void)
SetGetIncumbentGlobalCallback(JSContext* cx, JSGetIncumbentGlobalCallback callback);
/**
* Sets the callback that's invoked whenever a Promise job should be enqeued.
*
* SpiderMonkey doesn't schedule Promise resolution jobs itself; instead,
* using this function the embedding can provide a callback to do that
* scheduling. The provided `callback` is invoked with the promise job,
* the corresponding Promise's allocation stack, and the `data` pointer
* passed here as arguments.
*/
extern JS_PUBLIC_API(void)
SetEnqueuePromiseJobCallback(JSContext* cx, JSEnqueuePromiseJobCallback callback,
void* data = nullptr);
/**
* Sets the callback that's invoked whenever a Promise is rejected without
* a rejection handler, and when a Promise that was previously rejected
* without a handler gets a handler attached.
*/
extern JS_PUBLIC_API(void)
SetPromiseRejectionTrackerCallback(JSContext* cx, JSPromiseRejectionTrackerCallback callback,
void* data = nullptr);
/**
* Inform the runtime that the job queue is empty and the embedding is going to
* execute its last promise job. The runtime may now choose to skip creating
* promise jobs for asynchronous execution and instead continue execution
* synchronously. More specifically, this optimization is used to skip the
* standard job queuing behavior for `await` operations in async functions.
*
* This function may be called before executing the last job in the job queue.
* When it was called, JobQueueMayNotBeEmpty must be called in order to restore
* the default job queuing behavior before the embedding enqueues its next job
* into the job queue.
*/
extern JS_PUBLIC_API(void)
JobQueueIsEmpty(JSContext* cx);
/**
* Inform the runtime that job queue is no longer empty. The runtime can now no
* longer skip creating promise jobs for asynchronous execution, because
* pending jobs in the job queue must be executed first to preserve the FIFO
* (first in - first out) property of the queue. This effectively undoes
* JobQueueIsEmpty and re-enables the standard job queuing behavior.
*
* This function must be called whenever enqueuing a job to the job queue when
* JobQueueIsEmpty was called previously.
*/
extern JS_PUBLIC_API(void)
JobQueueMayNotBeEmpty(JSContext* cx);
/**
* Returns a new instance of the Promise builtin class in the current
* compartment, with the right slot layout.
*
* The `executor` can be a `nullptr`. In that case, the only way to resolve or
* reject the returned promise is via the `JS::ResolvePromise` and
* `JS::RejectPromise` JSAPI functions.
*
* If a `proto` is passed, that gets set as the instance's [[Prototype]]
* instead of the original value of `Promise.prototype`.
*/
extern JS_PUBLIC_API(JSObject*)
NewPromiseObject(JSContext* cx, JS::HandleObject executor, JS::HandleObject proto = nullptr);
/**
* Returns true if the given object is an unwrapped PromiseObject, false
* otherwise.
*/
extern JS_PUBLIC_API(bool)
IsPromiseObject(JS::HandleObject obj);
/**
* Returns the current compartment's original Promise constructor.
*/
extern JS_PUBLIC_API(JSObject*)
GetPromiseConstructor(JSContext* cx);
/**
* Returns the current compartment's original Promise.prototype.
*/
extern JS_PUBLIC_API(JSObject*)
GetPromisePrototype(JSContext* cx);
// Keep this in sync with the PROMISE_STATE defines in SelfHostingDefines.h.
enum class PromiseState {
Pending,
Fulfilled,
Rejected
};
/**
* Returns the given Promise's state as a JS::PromiseState enum value.
*
* Returns JS::PromiseState::Pending if the given object is a wrapper that
* can't safely be unwrapped.
*/
extern JS_PUBLIC_API(PromiseState)
GetPromiseState(JS::HandleObject promise);
/**
* Returns the given Promise's process-unique ID.
*/
JS_PUBLIC_API(uint64_t)
GetPromiseID(JS::HandleObject promise);
/**
* Returns the given Promise's result: either the resolution value for
* fulfilled promises, or the rejection reason for rejected ones.
*/
extern JS_PUBLIC_API(JS::Value)
GetPromiseResult(JS::HandleObject promise);
/**
* Returns a js::SavedFrame linked list of the stack that lead to the given
* Promise's allocation.
*/
extern JS_PUBLIC_API(JSObject*)
GetPromiseAllocationSite(JS::HandleObject promise);
extern JS_PUBLIC_API(JSObject*)
GetPromiseResolutionSite(JS::HandleObject promise);
#ifdef DEBUG
extern JS_PUBLIC_API(void)
DumpPromiseAllocationSite(JSContext* cx, JS::HandleObject promise);
extern JS_PUBLIC_API(void)
DumpPromiseResolutionSite(JSContext* cx, JS::HandleObject promise);
#endif
/**
* Calls the current compartment's original Promise.resolve on the original
* Promise constructor, with `resolutionValue` passed as an argument.
*/
extern JS_PUBLIC_API(JSObject*)
CallOriginalPromiseResolve(JSContext* cx, JS::HandleValue resolutionValue);
/**
* Calls the current compartment's original Promise.reject on the original
* Promise constructor, with `resolutionValue` passed as an argument.
*/
extern JS_PUBLIC_API(JSObject*)
CallOriginalPromiseReject(JSContext* cx, JS::HandleValue rejectionValue);
/**
* Resolves the given Promise with the given `resolutionValue`.
*
* Calls the `resolve` function that was passed to the executor function when
* the Promise was created.
*/
extern JS_PUBLIC_API(bool)
ResolvePromise(JSContext* cx, JS::HandleObject promiseObj, JS::HandleValue resolutionValue);
/**
* Rejects the given `promise` with the given `rejectionValue`.
*
* Calls the `reject` function that was passed to the executor function when
* the Promise was created.
*/
extern JS_PUBLIC_API(bool)
RejectPromise(JSContext* cx, JS::HandleObject promiseObj, JS::HandleValue rejectionValue);
/**
* Calls the current compartment's original Promise.prototype.then on the
* given `promise`, with `onResolve` and `onReject` passed as arguments.
*
* Asserts if the passed-in `promise` object isn't an unwrapped instance of
* `Promise` or a subclass or `onResolve` and `onReject` aren't both either
* `nullptr` or callable objects.
*/
extern JS_PUBLIC_API(JSObject*)
CallOriginalPromiseThen(JSContext* cx, JS::HandleObject promise,
JS::HandleObject onResolve, JS::HandleObject onReject);
/**
* Unforgeable, optimized version of the JS builtin Promise.prototype.then.
*
* Takes a Promise instance and `onResolve`, `onReject` callables to enqueue
* as reactions for that promise. In difference to Promise.prototype.then,
* this doesn't create and return a new Promise instance.
*
* Asserts if the passed-in `promise` object isn't an unwrapped instance of
* `Promise` or a subclass or `onResolve` and `onReject` aren't both callable
* objects.
*/
extern JS_PUBLIC_API(bool)
AddPromiseReactions(JSContext* cx, JS::HandleObject promise,
JS::HandleObject onResolve, JS::HandleObject onReject);
/**
* Unforgeable version of the JS builtin Promise.all.
*
* Takes an AutoObjectVector of Promise objects and returns a promise that's
* resolved with an array of resolution values when all those promises have
* been resolved, or rejected with the rejection value of the first rejected
* promise.
*
* Asserts that all objects in the `promises` vector are, maybe wrapped,
* instances of `Promise` or a subclass of `Promise`.
*/
extern JS_PUBLIC_API(JSObject*)
GetWaitForAllPromise(JSContext* cx, const JS::AutoObjectVector& promises);
/**
* The Dispatchable interface allows the embedding to call SpiderMonkey
* on a JSContext thread when requested via DispatchToEventLoopCallback.
*/
class JS_PUBLIC_API(Dispatchable)
{
protected:
// Dispatchables are created and destroyed by SpiderMonkey.
Dispatchable() = default;
virtual ~Dispatchable() = default;
public:
// ShuttingDown indicates that SpiderMonkey should abort async tasks to
// expedite shutdown.
enum MaybeShuttingDown { NotShuttingDown, ShuttingDown };
// Called by the embedding after DispatchToEventLoopCallback succeeds.
virtual void run(JSContext* cx, MaybeShuttingDown maybeShuttingDown) = 0;
};
/**
* DispatchToEventLoopCallback may be called from any thread, being passed the
* same 'closure' passed to InitDispatchToEventLoop() and Dispatchable from the
* same JSRuntime. If the embedding returns 'true', the embedding must call
* Dispatchable::run() on an active JSContext thread for the same JSRuntime on
* which 'closure' was registered. If DispatchToEventLoopCallback returns
* 'false', SpiderMonkey will assume a shutdown of the JSRuntime is in progress.
* This contract implies that, by the time the final JSContext is destroyed in
* the JSRuntime, the embedding must have (1) run all Dispatchables for which
* DispatchToEventLoopCallback returned true, (2) already started returning
* false from calls to DispatchToEventLoopCallback.
*/
typedef bool
(*DispatchToEventLoopCallback)(void* closure, Dispatchable* dispatchable);
extern JS_PUBLIC_API(void)
InitDispatchToEventLoop(JSContext* cx, DispatchToEventLoopCallback callback, void* closure);
/**
* The ConsumeStreamCallback is called from an active JSContext, passing a
* StreamConsumer that wishes to consume the given host object as a stream of
* bytes with the given MIME type. On failure, the embedding must report the
* appropriate error on 'cx'. On success, the embedding must call
* consumer->consumeChunk() repeatedly on any thread until exactly one of:
* - consumeChunk() returns false
* - the embedding calls consumer->streamClosed()
* before JS_DestroyContext(cx) or JS::ShutdownAsyncTasks(cx) is called.
*
* Note: consumeChunk() and streamClosed() may be called synchronously by
* ConsumeStreamCallback.
*/
class JS_PUBLIC_API(StreamConsumer)
{
protected:
// AsyncStreamConsumers are created and destroyed by SpiderMonkey.
StreamConsumer() = default;
virtual ~StreamConsumer() = default;
public:
// Called by the embedding as each chunk of bytes becomes available.
// If this function returns 'false', the stream must drop all pointers to
// this StreamConsumer.
virtual bool consumeChunk(const uint8_t* begin, size_t length) = 0;
// Called by the embedding when the stream is closed according to the
// contract described above.
enum CloseReason { EndOfFile, Error };
virtual void streamClosed(CloseReason reason) = 0;
// Provides optional stream attributes such as base or source mapping URLs.
// Necessarily called before consumeChunk() or streamClosed(). The caller
// retains ownership of the given strings.
virtual void noteResponseURLs(const char* maybeUrl, const char* maybeSourceMapUrl) = 0;
};
enum class MimeType { Wasm };
typedef bool
(*ConsumeStreamCallback)(JSContext* cx, JS::HandleObject obj, MimeType mimeType,
StreamConsumer* consumer);
extern JS_PUBLIC_API(void)
InitConsumeStreamCallback(JSContext* cx, ConsumeStreamCallback callback);
/**
* When a JSRuntime is destroyed it implicitly cancels all async tasks in
* progress, releasing any roots held by the task. However, this is not soon
* enough for cycle collection, which needs to have roots dropped earlier so
* that the cycle collector can transitively remove roots for a future GC. For
* these and other cases, the set of pending async tasks can be canceled
* with this call earlier than JSRuntime destruction.
*/
extern JS_PUBLIC_API(void)
ShutdownAsyncTasks(JSContext* cx);
/**
* Supply an alternative stack to incorporate into captured SavedFrame
* backtraces as the imputed caller of asynchronous JavaScript calls, like async
* function resumptions and DOM callbacks.
*
* When one async function awaits the result of another, it's natural to think
* of that as a sort of function call: just as execution resumes from an
* ordinary call expression when the callee returns, with the return value
* providing the value of the call expression, execution resumes from an 'await'
* expression after the awaited asynchronous function call returns, passing the
* return value along.
*
* Call the two async functions in such a situation the 'awaiter' and the
* 'awaitee'.
*
* As an async function, the awaitee contains 'await' expressions of its own.
* Whenever it executes after its first 'await', there are never any actual
* frames on the JavaScript stack under it; its awaiter is certainly not there.
* An await expression's continuation is invoked as a promise callback, and
* those are always called directly from the event loop in their own microtick.
* (Ignore unusual cases like nested event loops.)
*
* But because await expressions bear such a strong resemblance to calls (and
* deliberately so!), it would be unhelpful for stacks captured within the
* awaitee to be empty; instead, they should present the awaiter as the caller.
*
* The AutoSetAsyncStackForNewCalls RAII class supplies a SavedFrame stack to
* treat as the caller of any JavaScript invocations that occur within its
* lifetime. Any SavedFrame stack captured during such an invocation uses the
* SavedFrame passed to the constructor's 'stack' parameter as the 'asyncParent'
* property of the SavedFrame for the invocation's oldest frame. Its 'parent'
* property will be null, so stack-walking code can distinguish this
* awaiter/awaitee transition from an ordinary caller/callee transition.
*
* The constructor's 'asyncCause' parameter supplies a string explaining what
* sort of asynchronous call caused 'stack' to be spliced into the backtrace;
* for example, async function resumptions use the string "async". This appears
* as the 'asyncCause' property of the 'asyncParent' SavedFrame.
*
* Async callers are distinguished in the string form of a SavedFrame chain by
* including the 'asyncCause' string in the frame. It appears before the
* function name, with the two separated by a '*'.
*
* Note that, as each compartment has its own set of SavedFrames, the
* 'asyncParent' may actually point to a copy of 'stack', rather than the exact
* SavedFrame object passed.
*
* The youngest frame of 'stack' is not mutated to take the asyncCause string as
* its 'asyncCause' property; SavedFrame objects are immutable. Rather, a fresh
* clone of the frame is created with the needed 'asyncCause' property.
*
* The 'kind' argument specifies how aggressively 'stack' supplants any
* JavaScript frames older than this AutoSetAsyncStackForNewCalls object. If
* 'kind' is 'EXPLICIT', then all captured SavedFrame chains take on 'stack' as
* their 'asyncParent' where the chain crosses this object's scope. If 'kind' is
* 'IMPLICIT', then 'stack' is only included in captured chains if there are no
* other JavaScript frames on the stack --- that is, only if the stack would
* otherwise end at that point.
*
* AutoSetAsyncStackForNewCalls affects only SavedFrame chains; it does not
* affect Debugger.Frame or js::FrameIter. SavedFrame chains are used for
* Error.stack, allocation profiling, Promise debugging, and so on.
*
* See also `js/src/doc/SavedFrame/SavedFrame.md` for documentation on async
* stack frames.
*/
class MOZ_STACK_CLASS JS_PUBLIC_API(AutoSetAsyncStackForNewCalls)
{
JSContext* cx;
RootedObject oldAsyncStack;
const char* oldAsyncCause;
bool oldAsyncCallIsExplicit;
public:
enum class AsyncCallKind {
// The ordinary kind of call, where we may apply an async
// parent if there is no ordinary parent.
IMPLICIT,
// An explicit async parent, e.g., callFunctionWithAsyncStack,
// where we always want to override any ordinary parent.
EXPLICIT
};
// The stack parameter cannot be null by design, because it would be
// ambiguous whether that would clear any scheduled async stack and make the
// normal stack reappear in the new call, or just keep the async stack
// already scheduled for the new call, if any.
//
// asyncCause is owned by the caller and its lifetime must outlive the
// lifetime of the AutoSetAsyncStackForNewCalls object. It is strongly
// encouraged that asyncCause be a string constant or similar statically
// allocated string.
AutoSetAsyncStackForNewCalls(JSContext* cx, HandleObject stack,
const char* asyncCause,
AsyncCallKind kind = AsyncCallKind::IMPLICIT);
~AutoSetAsyncStackForNewCalls();
};
} // namespace JS
/************************************************************************/
/*
* Strings.
*
* NB: JS_NewUCString takes ownership of bytes on success, avoiding a copy;
* but on error (signified by null return), it leaves chars owned by the
* caller. So the caller must free bytes in the error case, if it has no use
* for them. In contrast, all the JS_New*StringCopy* functions do not take
* ownership of the character memory passed to them -- they copy it.
*/
extern JS_PUBLIC_API(JSString*)
JS_NewStringCopyN(JSContext* cx, const char* s, size_t n);
extern JS_PUBLIC_API(JSString*)
JS_NewStringCopyZ(JSContext* cx, const char* s);
extern JS_PUBLIC_API(JSString*)
JS_NewStringCopyUTF8Z(JSContext* cx, const JS::ConstUTF8CharsZ s);
extern JS_PUBLIC_API(JSString*)
JS_NewStringCopyUTF8N(JSContext* cx, const JS::UTF8Chars s);
extern JS_PUBLIC_API(JSString*)
JS_AtomizeAndPinJSString(JSContext* cx, JS::HandleString str);
extern JS_PUBLIC_API(JSString*)
JS_AtomizeStringN(JSContext* cx, const char* s, size_t length);
extern JS_PUBLIC_API(JSString*)
JS_AtomizeString(JSContext* cx, const char* s);
extern JS_PUBLIC_API(JSString*)
JS_AtomizeAndPinStringN(JSContext* cx, const char* s, size_t length);
extern JS_PUBLIC_API(JSString*)
JS_AtomizeAndPinString(JSContext* cx, const char* s);
extern JS_PUBLIC_API(JSString*)
JS_NewLatin1String(JSContext* cx, JS::Latin1Char* chars, size_t length);
extern JS_PUBLIC_API(JSString*)
JS_NewUCString(JSContext* cx, char16_t* chars, size_t length);
extern JS_PUBLIC_API(JSString*)
JS_NewUCStringDontDeflate(JSContext* cx, char16_t* chars, size_t length);
extern JS_PUBLIC_API(JSString*)
JS_NewUCStringCopyN(JSContext* cx, const char16_t* s, size_t n);
extern JS_PUBLIC_API(JSString*)
JS_NewUCStringCopyZ(JSContext* cx, const char16_t* s);
extern JS_PUBLIC_API(JSString*)
JS_AtomizeUCStringN(JSContext* cx, const char16_t* s, size_t length);
extern JS_PUBLIC_API(JSString*)
JS_AtomizeUCString(JSContext* cx, const char16_t* s);
extern JS_PUBLIC_API(JSString*)
JS_AtomizeAndPinUCStringN(JSContext* cx, const char16_t* s, size_t length);
extern JS_PUBLIC_API(JSString*)
JS_AtomizeAndPinUCString(JSContext* cx, const char16_t* s);
extern JS_PUBLIC_API(bool)
JS_CompareStrings(JSContext* cx, JSString* str1, JSString* str2, int32_t* result);
extern JS_PUBLIC_API(bool)
JS_StringEqualsAscii(JSContext* cx, JSString* str, const char* asciiBytes, bool* match);
extern JS_PUBLIC_API(size_t)
JS_PutEscapedString(JSContext* cx, char* buffer, size_t size, JSString* str, char quote);
/*
* Extracting string characters and length.
*
* While getting the length of a string is infallible, getting the chars can
* fail. As indicated by the lack of a JSContext parameter, there are two
* special cases where getting the chars is infallible:
*
* The first case is for strings that have been atomized, e.g. directly by
* JS_AtomizeAndPinString or implicitly because it is stored in a jsid.
*
* The second case is "flat" strings that have been explicitly prepared in a
* fallible context by JS_FlattenString. To catch errors, a separate opaque
* JSFlatString type is returned by JS_FlattenString and expected by
* JS_GetFlatStringChars. Note, though, that this is purely a syntactic
* distinction: the input and output of JS_FlattenString are the same actual
* GC-thing. If a JSString is known to be flat, JS_ASSERT_STRING_IS_FLAT can be
* used to make a debug-checked cast. Example:
*
* // in a fallible context
* JSFlatString* fstr = JS_FlattenString(cx, str);
* if (!fstr)
* return false;
* MOZ_ASSERT(fstr == JS_ASSERT_STRING_IS_FLAT(str));
*
* // in an infallible context, for the same 'str'
* AutoCheckCannotGC nogc;
* const char16_t* chars = JS_GetTwoByteFlatStringChars(nogc, fstr)
* MOZ_ASSERT(chars);
*
* Flat strings and interned strings are always null-terminated, so
* JS_FlattenString can be used to get a null-terminated string.
*
* Additionally, string characters are stored as either Latin1Char (8-bit)
* or char16_t (16-bit). Clients can use JS_StringHasLatin1Chars and can then
* call either the Latin1* or TwoByte* functions. Some functions like
* JS_CopyStringChars and JS_GetStringCharAt accept both Latin1 and TwoByte
* strings.
*/
extern JS_PUBLIC_API(size_t)
JS_GetStringLength(JSString* str);
extern JS_PUBLIC_API(bool)
JS_StringIsFlat(JSString* str);
/** Returns true iff the string's characters are stored as Latin1. */
extern JS_PUBLIC_API(bool)
JS_StringHasLatin1Chars(JSString* str);
extern JS_PUBLIC_API(const JS::Latin1Char*)
JS_GetLatin1StringCharsAndLength(JSContext* cx, const JS::AutoRequireNoGC& nogc, JSString* str,
size_t* length);
extern JS_PUBLIC_API(const char16_t*)
JS_GetTwoByteStringCharsAndLength(JSContext* cx, const JS::AutoRequireNoGC& nogc, JSString* str,
size_t* length);
extern JS_PUBLIC_API(bool)
JS_GetStringCharAt(JSContext* cx, JSString* str, size_t index, char16_t* res);
extern JS_PUBLIC_API(char16_t)
JS_GetFlatStringCharAt(JSFlatString* str, size_t index);
extern JS_PUBLIC_API(const char16_t*)
JS_GetTwoByteExternalStringChars(JSString* str);
extern JS_PUBLIC_API(bool)
JS_CopyStringChars(JSContext* cx, mozilla::Range<char16_t> dest, JSString* str);
extern JS_PUBLIC_API(JSFlatString*)
JS_FlattenString(JSContext* cx, JSString* str);
extern JS_PUBLIC_API(const JS::Latin1Char*)
JS_GetLatin1FlatStringChars(const JS::AutoRequireNoGC& nogc, JSFlatString* str);
extern JS_PUBLIC_API(const char16_t*)
JS_GetTwoByteFlatStringChars(const JS::AutoRequireNoGC& nogc, JSFlatString* str);
static MOZ_ALWAYS_INLINE JSFlatString*
JSID_TO_FLAT_STRING(jsid id)
{
MOZ_ASSERT(JSID_IS_STRING(id));
return (JSFlatString*)JSID_TO_STRING(id);
}
static MOZ_ALWAYS_INLINE JSFlatString*
JS_ASSERT_STRING_IS_FLAT(JSString* str)
{
MOZ_ASSERT(JS_StringIsFlat(str));
return (JSFlatString*)str;
}
static MOZ_ALWAYS_INLINE JSString*
JS_FORGET_STRING_FLATNESS(JSFlatString* fstr)
{
return (JSString*)fstr;
}
/*
* Additional APIs that avoid fallibility when given a flat string.
*/
extern JS_PUBLIC_API(bool)
JS_FlatStringEqualsAscii(JSFlatString* str, const char* asciiBytes);
extern JS_PUBLIC_API(size_t)
JS_PutEscapedFlatString(char* buffer, size_t size, JSFlatString* str, char quote);
/**
* Create a dependent string, i.e., a string that owns no character storage,
* but that refers to a slice of another string's chars. Dependent strings
* are mutable by definition, so the thread safety comments above apply.
*/
extern JS_PUBLIC_API(JSString*)
JS_NewDependentString(JSContext* cx, JS::HandleString str, size_t start,
size_t length);
/**
* Concatenate two strings, possibly resulting in a rope.
* See above for thread safety comments.
*/
extern JS_PUBLIC_API(JSString*)
JS_ConcatStrings(JSContext* cx, JS::HandleString left, JS::HandleString right);
/**
* For JS_DecodeBytes, set *dstlenp to the size of the destination buffer before
* the call; on return, *dstlenp contains the number of characters actually
* stored. To determine the necessary destination buffer size, make a sizing
* call that passes nullptr for dst.
*
* On errors, the functions report the error. In that case, *dstlenp contains
* the number of characters or bytes transferred so far. If cx is nullptr, no
* error is reported on failure, and the functions simply return false.
*
* NB: This function does not store an additional zero byte or char16_t after the
* transcoded string.
*/
JS_PUBLIC_API(bool)
JS_DecodeBytes(JSContext* cx, const char* src, size_t srclen, char16_t* dst,
size_t* dstlenp);
/**
* A variation on JS_EncodeCharacters where a null terminated string is
* returned that you are expected to call JS_free on when done.
*/
JS_PUBLIC_API(char*)
JS_EncodeString(JSContext* cx, JSString* str);
/**
* Same behavior as JS_EncodeString(), but encode into UTF-8 string
*/
JS_PUBLIC_API(char*)
JS_EncodeStringToUTF8(JSContext* cx, JS::HandleString str);
/**
* Get number of bytes in the string encoding (without accounting for a
* terminating zero bytes. The function returns (size_t) -1 if the string
* can not be encoded into bytes and reports an error using cx accordingly.
*/
JS_PUBLIC_API(size_t)
JS_GetStringEncodingLength(JSContext* cx, JSString* str);
/**
* Encode string into a buffer. The function does not stores an additional
* zero byte. The function returns (size_t) -1 if the string can not be
* encoded into bytes with no error reported. Otherwise it returns the number
* of bytes that are necessary to encode the string. If that exceeds the
* length parameter, the string will be cut and only length bytes will be
* written into the buffer.
*/
MOZ_MUST_USE JS_PUBLIC_API(bool)
JS_EncodeStringToBuffer(JSContext* cx, JSString* str, char* buffer, size_t length);
class MOZ_RAII JSAutoByteString
{
public:
JSAutoByteString(JSContext* cx, JSString* str
MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
: mBytes(JS_EncodeString(cx, str))
{
MOZ_ASSERT(cx);
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
}
explicit JSAutoByteString(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM)
: mBytes(nullptr)
{
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
}
~JSAutoByteString() {
JS_free(nullptr, mBytes);
}
/* Take ownership of the given byte array. */
void initBytes(JS::UniqueChars&& bytes) {
MOZ_ASSERT(!mBytes);
mBytes = bytes.release();
}
char* encodeLatin1(JSContext* cx, JSString* str) {
MOZ_ASSERT(!mBytes);
MOZ_ASSERT(cx);
mBytes = JS_EncodeString(cx, str);
return mBytes;
}
char* encodeUtf8(JSContext* cx, JS::HandleString str) {
MOZ_ASSERT(!mBytes);
MOZ_ASSERT(cx);
mBytes = JS_EncodeStringToUTF8(cx, str);
return mBytes;
}
void clear() {
js_free(mBytes);
mBytes = nullptr;
}
char* ptr() const {
return mBytes;
}
bool operator!() const {
return !mBytes;
}
size_t length() const {
if (!mBytes)
return 0;
return strlen(mBytes);
}
private:
char* mBytes;
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
/* Copy and assignment are not supported. */
JSAutoByteString(const JSAutoByteString& another);
JSAutoByteString& operator=(const JSAutoByteString& another);
};
/************************************************************************/
/*
* Symbols
*/
namespace JS {
/**
* Create a new Symbol with the given description. This function never returns
* a Symbol that is in the Runtime-wide symbol registry.
*
* If description is null, the new Symbol's [[Description]] attribute is
* undefined.
*/
JS_PUBLIC_API(Symbol*)
NewSymbol(JSContext* cx, HandleString description);
/**
* Symbol.for as specified in ES6.
*
* Get a Symbol with the description 'key' from the Runtime-wide symbol registry.
* If there is not already a Symbol with that description in the registry, a new
* Symbol is created and registered. 'key' must not be null.
*/
JS_PUBLIC_API(Symbol*)
GetSymbolFor(JSContext* cx, HandleString key);
/**
* Get the [[Description]] attribute of the given symbol.
*
* This function is infallible. If it returns null, that means the symbol's
* [[Description]] is undefined.
*/
JS_PUBLIC_API(JSString*)
GetSymbolDescription(HandleSymbol symbol);
/* Well-known symbols. */
#define JS_FOR_EACH_WELL_KNOWN_SYMBOL(macro) \
macro(isConcatSpreadable) \
macro(iterator) \
macro(match) \
macro(replace) \
macro(search) \
macro(species) \
macro(hasInstance) \
macro(split) \
macro(toPrimitive) \
macro(toStringTag) \
macro(unscopables) \
macro(asyncIterator)
enum class SymbolCode : uint32_t {
// There is one SymbolCode for each well-known symbol.
#define JS_DEFINE_SYMBOL_ENUM(name) name,
JS_FOR_EACH_WELL_KNOWN_SYMBOL(JS_DEFINE_SYMBOL_ENUM) // SymbolCode::iterator, etc.
#undef JS_DEFINE_SYMBOL_ENUM
Limit,
WellKnownAPILimit = 0x80000000, // matches JS::shadow::Symbol::WellKnownAPILimit for inline use
InSymbolRegistry = 0xfffffffe, // created by Symbol.for() or JS::GetSymbolFor()
UniqueSymbol = 0xffffffff // created by Symbol() or JS::NewSymbol()
};
/* For use in loops that iterate over the well-known symbols. */
const size_t WellKnownSymbolLimit = size_t(SymbolCode::Limit);
/**
* Return the SymbolCode telling what sort of symbol `symbol` is.
*
* A symbol's SymbolCode never changes once it is created.
*/
JS_PUBLIC_API(SymbolCode)
GetSymbolCode(Handle<Symbol*> symbol);
/**
* Get one of the well-known symbols defined by ES6. A single set of well-known
* symbols is shared by all compartments in a JSRuntime.
*
* `which` must be in the range [0, WellKnownSymbolLimit).
*/
JS_PUBLIC_API(Symbol*)
GetWellKnownSymbol(JSContext* cx, SymbolCode which);
/**
* Return true if the given JSPropertySpec::name or JSFunctionSpec::name value
* is actually a symbol code and not a string. See JS_SYM_FN.
*/
inline bool
PropertySpecNameIsSymbol(const char* name)
{
uintptr_t u = reinterpret_cast<uintptr_t>(name);
return u != 0 && u - 1 < WellKnownSymbolLimit;
}
JS_PUBLIC_API(bool)
PropertySpecNameEqualsId(const char* name, HandleId id);
/**
* Create a jsid that does not need to be marked for GC.
*
* 'name' is a JSPropertySpec::name or JSFunctionSpec::name value. The
* resulting jsid, on success, is either an interned string or a well-known
* symbol; either way it is immune to GC so there is no need to visit *idp
* during GC marking.
*/
JS_PUBLIC_API(bool)
PropertySpecNameToPermanentId(JSContext* cx, const char* name, jsid* idp);
} /* namespace JS */
/************************************************************************/
/*
* JSON functions
*/
typedef bool (* JSONWriteCallback)(const char16_t* buf, uint32_t len, void* data);
/**
* JSON.stringify as specified by ES5.
*/
JS_PUBLIC_API(bool)
JS_Stringify(JSContext* cx, JS::MutableHandleValue value, JS::HandleObject replacer,
JS::HandleValue space, JSONWriteCallback callback, void* data);
namespace JS {
/**
* An API akin to JS_Stringify but with the goal of not having observable
* side-effects when the stringification is performed. This means it does not
* allow a replacer or a custom space, and has the following constraints on its
* input:
*
* 1) The input must be a plain object or array, not an abitrary value.
* 2) Every value in the graph reached by the algorithm starting with this
* object must be one of the following: null, undefined, a string (NOT a
* string object!), a boolean, a finite number (i.e. no NaN or Infinity or
* -Infinity), a plain object with no accessor properties, or an Array with
* no holes.
*
* The actual behavior differs from JS_Stringify only in asserting the above and
* NOT attempting to get the "toJSON" property from things, since that could
* clearly have side-effects.
*/
JS_PUBLIC_API(bool)
ToJSONMaybeSafely(JSContext* cx, JS::HandleObject input,
JSONWriteCallback callback, void* data);
} /* namespace JS */
/**
* JSON.parse as specified by ES5.
*/
JS_PUBLIC_API(bool)
JS_ParseJSON(JSContext* cx, const char16_t* chars, uint32_t len, JS::MutableHandleValue vp);
JS_PUBLIC_API(bool)
JS_ParseJSON(JSContext* cx, JS::HandleString str, JS::MutableHandleValue vp);
JS_PUBLIC_API(bool)
JS_ParseJSONWithReviver(JSContext* cx, const char16_t* chars, uint32_t len, JS::HandleValue reviver,
JS::MutableHandleValue vp);
JS_PUBLIC_API(bool)
JS_ParseJSONWithReviver(JSContext* cx, JS::HandleString str, JS::HandleValue reviver,
JS::MutableHandleValue vp);
/************************************************************************/
/**
* The default locale for the ECMAScript Internationalization API
* (Intl.Collator, Intl.NumberFormat, Intl.DateTimeFormat).
* Note that the Internationalization API encourages clients to
* specify their own locales.
* The locale string remains owned by the caller.
*/
extern JS_PUBLIC_API(bool)
JS_SetDefaultLocale(JSRuntime* rt, const char* locale);
/**
* Look up the default locale for the ECMAScript Internationalization API.
* NB: The locale information is retrieved from cx's runtime.
*/
extern JS_PUBLIC_API(JS::UniqueChars)
JS_GetDefaultLocale(JSContext* cx);
/**
* Reset the default locale to OS defaults.
*/
extern JS_PUBLIC_API(void)
JS_ResetDefaultLocale(JSRuntime* rt);
/**
* Locale specific string conversion and error message callbacks.
*/
struct JSLocaleCallbacks {
JSLocaleToUpperCase localeToUpperCase; // not used #if EXPOSE_INTL_API
JSLocaleToLowerCase localeToLowerCase; // not used #if EXPOSE_INTL_API
JSLocaleCompare localeCompare; // not used #if EXPOSE_INTL_API
JSLocaleToUnicode localeToUnicode;
};
/**
* Establish locale callbacks. The pointer must persist as long as the
* JSContext. Passing nullptr restores the default behaviour.
*/
extern JS_PUBLIC_API(void)
JS_SetLocaleCallbacks(JSRuntime* rt, const JSLocaleCallbacks* callbacks);
/**
* Return the address of the current locale callbacks struct, which may
* be nullptr.
*/
extern JS_PUBLIC_API(const JSLocaleCallbacks*)
JS_GetLocaleCallbacks(JSRuntime* rt);
/************************************************************************/
/*
* Error reporting.
*
* There are four encoding variants for the error reporting API:
* UTF-8
* JSAPI's default encoding for error handling. Use this when the encoding
* of the error message, format string, and arguments is UTF-8.
* ASCII
* Equivalent to UTF-8, but also asserts that the error message, format
* string, and arguments are all ASCII. Because ASCII is a subset of UTF-8,
* any use of this encoding variant *could* be replaced with use of the
* UTF-8 variant. This variant exists solely to double-check the
* developer's assumption that all these strings truly are ASCII, given that
* UTF-8 and ASCII strings regrettably have the same C++ type.
* UC = UTF-16
* Use this when arguments are UTF-16. The format string must be UTF-8.
* Latin1 (planned to be removed)
* In this variant, all strings are interpreted byte-for-byte as the
* corresponding Unicode codepoint. This encoding may *safely* be used on
* any null-terminated string, regardless of its encoding. (You shouldn't
* *actually* be uncertain, but in the real world, a string's encoding -- if
* promised at all -- may be more...aspirational...than reality.) This
* encoding variant will eventually be removed -- work to convert your uses
* to UTF-8 as you're able.
*/
namespace JS {
const uint16_t MaxNumErrorArguments = 10;
};
/**
* Report an exception represented by the sprintf-like conversion of format
* and its arguments.
*/
extern JS_PUBLIC_API(void)
JS_ReportErrorASCII(JSContext* cx, const char* format, ...)
MOZ_FORMAT_PRINTF(2, 3);
extern JS_PUBLIC_API(void)
JS_ReportErrorLatin1(JSContext* cx, const char* format, ...)
MOZ_FORMAT_PRINTF(2, 3);
extern JS_PUBLIC_API(void)
JS_ReportErrorUTF8(JSContext* cx, const char* format, ...)
MOZ_FORMAT_PRINTF(2, 3);
/*
* Use an errorNumber to retrieve the format string, args are char*
*/
extern JS_PUBLIC_API(void)
JS_ReportErrorNumberASCII(JSContext* cx, JSErrorCallback errorCallback,
void* userRef, const unsigned errorNumber, ...);
extern JS_PUBLIC_API(void)
JS_ReportErrorNumberASCIIVA(JSContext* cx, JSErrorCallback errorCallback,
void* userRef, const unsigned errorNumber, va_list ap);
extern JS_PUBLIC_API(void)
JS_ReportErrorNumberLatin1(JSContext* cx, JSErrorCallback errorCallback,
void* userRef, const unsigned errorNumber, ...);
#ifdef va_start
extern JS_PUBLIC_API(void)
JS_ReportErrorNumberLatin1VA(JSContext* cx, JSErrorCallback errorCallback,
void* userRef, const unsigned errorNumber, va_list ap);
#endif
extern JS_PUBLIC_API(void)
JS_ReportErrorNumberUTF8(JSContext* cx, JSErrorCallback errorCallback,
void* userRef, const unsigned errorNumber, ...);
#ifdef va_start
extern JS_PUBLIC_API(void)
JS_ReportErrorNumberUTF8VA(JSContext* cx, JSErrorCallback errorCallback,
void* userRef, const unsigned errorNumber, va_list ap);
#endif
/*
* Use an errorNumber to retrieve the format string, args are char16_t*
*/
extern JS_PUBLIC_API(void)
JS_ReportErrorNumberUC(JSContext* cx, JSErrorCallback errorCallback,
void* userRef, const unsigned errorNumber, ...);
extern JS_PUBLIC_API(void)
JS_ReportErrorNumberUCArray(JSContext* cx, JSErrorCallback errorCallback,
void* userRef, const unsigned errorNumber,
const char16_t** args);
/**
* As above, but report a warning instead (JSREPORT_IS_WARNING(report.flags)).
* Return true if there was no error trying to issue the warning, and if the
* warning was not converted into an error due to the JSOPTION_WERROR option
* being set, false otherwise.
*/
extern JS_PUBLIC_API(bool)
JS_ReportWarningASCII(JSContext* cx, const char* format, ...)
MOZ_FORMAT_PRINTF(2, 3);
extern JS_PUBLIC_API(bool)
JS_ReportWarningLatin1(JSContext* cx, const char* format, ...)
MOZ_FORMAT_PRINTF(2, 3);
extern JS_PUBLIC_API(bool)
JS_ReportWarningUTF8(JSContext* cx, const char* format, ...)
MOZ_FORMAT_PRINTF(2, 3);
extern JS_PUBLIC_API(bool)
JS_ReportErrorFlagsAndNumberASCII(JSContext* cx, unsigned flags,
JSErrorCallback errorCallback, void* userRef,
const unsigned errorNumber, ...);
extern JS_PUBLIC_API(bool)
JS_ReportErrorFlagsAndNumberLatin1(JSContext* cx, unsigned flags,
JSErrorCallback errorCallback, void* userRef,
const unsigned errorNumber, ...);
extern JS_PUBLIC_API(bool)
JS_ReportErrorFlagsAndNumberUTF8(JSContext* cx, unsigned flags,
JSErrorCallback errorCallback, void* userRef,
const unsigned errorNumber, ...);
extern JS_PUBLIC_API(bool)
JS_ReportErrorFlagsAndNumberUC(JSContext* cx, unsigned flags,
JSErrorCallback errorCallback, void* userRef,
const unsigned errorNumber, ...);
/**
* Complain when out of memory.
*/
extern MOZ_COLD JS_PUBLIC_API(void)
JS_ReportOutOfMemory(JSContext* cx);
/**
* Complain when an allocation size overflows the maximum supported limit.
*/
extern JS_PUBLIC_API(void)
JS_ReportAllocationOverflow(JSContext* cx);
/**
* Base class that implements parts shared by JSErrorReport and
* JSErrorNotes::Note.
*/
class JSErrorBase
{
// The (default) error message.
// If ownsMessage_ is true, the it is freed in destructor.
JS::ConstUTF8CharsZ message_;
public:
JSErrorBase()
: filename(nullptr), lineno(0), column(0),
errorNumber(0),
ownsMessage_(false)
{}
~JSErrorBase() {
freeMessage();
}
// Source file name, URL, etc., or null.
const char* filename;
// Source line number.
unsigned lineno;
// Zero-based column index in line.
unsigned column;
// the error number, e.g. see js.msg.
unsigned errorNumber;
private:
bool ownsMessage_ : 1;
public:
const JS::ConstUTF8CharsZ message() const {
return message_;
}
void initOwnedMessage(const char* messageArg) {
initBorrowedMessage(messageArg);
ownsMessage_ = true;
}
void initBorrowedMessage(const char* messageArg) {
MOZ_ASSERT(!message_);
message_ = JS::ConstUTF8CharsZ(messageArg, strlen(messageArg));
}
JSString* newMessageString(JSContext* cx);
private:
void freeMessage();
};
/**
* Notes associated with JSErrorReport.
*/
class JSErrorNotes
{
public:
class Note : public JSErrorBase
{};
private:
// Stores pointers to each note.
js::Vector<js::UniquePtr<Note>, 1, js::SystemAllocPolicy> notes_;
public:
JSErrorNotes();
~JSErrorNotes();
// Add an note to the given position.
bool addNoteASCII(JSContext* cx,
const char* filename, unsigned lineno, unsigned column,
JSErrorCallback errorCallback, void* userRef,
const unsigned errorNumber, ...);
bool addNoteLatin1(JSContext* cx,
const char* filename, unsigned lineno, unsigned column,
JSErrorCallback errorCallback, void* userRef,
const unsigned errorNumber, ...);
bool addNoteUTF8(JSContext* cx,
const char* filename, unsigned lineno, unsigned column,
JSErrorCallback errorCallback, void* userRef,
const unsigned errorNumber, ...);
JS_PUBLIC_API(size_t) length();
// Create a deep copy of notes.
js::UniquePtr<JSErrorNotes> copy(JSContext* cx);
class iterator : public std::iterator<std::input_iterator_tag, js::UniquePtr<Note>>
{
js::UniquePtr<Note>* note_;
public:
explicit iterator(js::UniquePtr<Note>* note = nullptr) : note_(note)
{}
bool operator==(iterator other) const {
return note_ == other.note_;
}
bool operator!=(iterator other) const {
return !(*this == other);
}
iterator& operator++() {
note_++;
return *this;
}
reference operator*() {
return *note_;
}
};
JS_PUBLIC_API(iterator) begin();
JS_PUBLIC_API(iterator) end();
};
/**
* Describes a single error or warning that occurs in the execution of script.
*/
class JSErrorReport : public JSErrorBase
{
// Offending source line without final '\n'.
// If ownsLinebuf_ is true, the buffer is freed in destructor.
const char16_t* linebuf_;
// Number of chars in linebuf_. Does not include trailing '\0'.
size_t linebufLength_;
// The 0-based offset of error token in linebuf_.
size_t tokenOffset_;
public:
JSErrorReport()
: linebuf_(nullptr), linebufLength_(0), tokenOffset_(0),
notes(nullptr),
flags(0), exnType(0), isMuted(false),
ownsLinebuf_(false)
{}
~JSErrorReport() {
freeLinebuf();
}
// Associated notes, or nullptr if there's no note.
js::UniquePtr<JSErrorNotes> notes;
// error/warning, etc.
unsigned flags;
// One of the JSExnType constants.
int16_t exnType;
// See the comment in TransitiveCompileOptions.
bool isMuted : 1;
private:
bool ownsLinebuf_ : 1;
public:
const char16_t* linebuf() const {
return linebuf_;
}
size_t linebufLength() const {
return linebufLength_;
}
size_t tokenOffset() const {
return tokenOffset_;
}
void initOwnedLinebuf(const char16_t* linebufArg, size_t linebufLengthArg,
size_t tokenOffsetArg) {
initBorrowedLinebuf(linebufArg, linebufLengthArg, tokenOffsetArg);
ownsLinebuf_ = true;
}
void initBorrowedLinebuf(const char16_t* linebufArg, size_t linebufLengthArg,
size_t tokenOffsetArg);
private:
void freeLinebuf();
};
/*
* JSErrorReport flag values. These may be freely composed.
*/
#define JSREPORT_ERROR 0x0 /* pseudo-flag for default case */
#define JSREPORT_WARNING 0x1 /* reported via JS_ReportWarning */
#define JSREPORT_EXCEPTION 0x2 /* exception was thrown */
#define JSREPORT_STRICT 0x4 /* error or warning due to strict option */
#define JSREPORT_USER_1 0x8 /* user-defined flag */
/*
* If JSREPORT_EXCEPTION is set, then a JavaScript-catchable exception
* has been thrown for this runtime error, and the host should ignore it.
* Exception-aware hosts should also check for JS_IsExceptionPending if
* JS_ExecuteScript returns failure, and signal or propagate the exception, as
* appropriate.
*/
#define JSREPORT_IS_WARNING(flags) (((flags) & JSREPORT_WARNING) != 0)
#define JSREPORT_IS_EXCEPTION(flags) (((flags) & JSREPORT_EXCEPTION) != 0)
#define JSREPORT_IS_STRICT(flags) (((flags) & JSREPORT_STRICT) != 0)
namespace JS {
using WarningReporter = void (*)(JSContext* cx, JSErrorReport* report);
extern JS_PUBLIC_API(WarningReporter)
SetWarningReporter(JSContext* cx, WarningReporter reporter);
extern JS_PUBLIC_API(WarningReporter)
GetWarningReporter(JSContext* cx);
extern JS_PUBLIC_API(bool)
CreateError(JSContext* cx, JSExnType type, HandleObject stack,
HandleString fileName, uint32_t lineNumber, uint32_t columnNumber,
JSErrorReport* report, HandleString message, MutableHandleValue rval);
/************************************************************************/
/*
* Weak Maps.
*/
extern JS_PUBLIC_API(JSObject*)
NewWeakMapObject(JSContext* cx);
extern JS_PUBLIC_API(bool)
IsWeakMapObject(JSObject* obj);
extern JS_PUBLIC_API(bool)
GetWeakMapEntry(JSContext* cx, JS::HandleObject mapObj, JS::HandleObject key,
JS::MutableHandleValue val);
extern JS_PUBLIC_API(bool)
SetWeakMapEntry(JSContext* cx, JS::HandleObject mapObj, JS::HandleObject key,
JS::HandleValue val);
/*
* Map
*/
extern JS_PUBLIC_API(JSObject*)
NewMapObject(JSContext* cx);
extern JS_PUBLIC_API(uint32_t)
MapSize(JSContext* cx, HandleObject obj);
extern JS_PUBLIC_API(bool)
MapGet(JSContext* cx, HandleObject obj,
HandleValue key, MutableHandleValue rval);
extern JS_PUBLIC_API(bool)
MapHas(JSContext* cx, HandleObject obj, HandleValue key, bool* rval);
extern JS_PUBLIC_API(bool)
MapSet(JSContext* cx, HandleObject obj, HandleValue key, HandleValue val);
extern JS_PUBLIC_API(bool)
MapDelete(JSContext *cx, HandleObject obj, HandleValue key, bool *rval);
extern JS_PUBLIC_API(bool)
MapClear(JSContext* cx, HandleObject obj);
extern JS_PUBLIC_API(bool)
MapKeys(JSContext* cx, HandleObject obj, MutableHandleValue rval);
extern JS_PUBLIC_API(bool)
MapValues(JSContext* cx, HandleObject obj, MutableHandleValue rval);
extern JS_PUBLIC_API(bool)
MapEntries(JSContext* cx, HandleObject obj, MutableHandleValue rval);
extern JS_PUBLIC_API(bool)
MapForEach(JSContext *cx, HandleObject obj, HandleValue callbackFn, HandleValue thisVal);
/*
* Set
*/
extern JS_PUBLIC_API(JSObject *)
NewSetObject(JSContext *cx);
extern JS_PUBLIC_API(uint32_t)
SetSize(JSContext *cx, HandleObject obj);
extern JS_PUBLIC_API(bool)
SetHas(JSContext *cx, HandleObject obj, HandleValue key, bool *rval);
extern JS_PUBLIC_API(bool)
SetDelete(JSContext *cx, HandleObject obj, HandleValue key, bool *rval);
extern JS_PUBLIC_API(bool)
SetAdd(JSContext *cx, HandleObject obj, HandleValue key);
extern JS_PUBLIC_API(bool)
SetClear(JSContext *cx, HandleObject obj);
extern JS_PUBLIC_API(bool)
SetKeys(JSContext *cx, HandleObject obj, MutableHandleValue rval);
extern JS_PUBLIC_API(bool)
SetValues(JSContext *cx, HandleObject obj, MutableHandleValue rval);
extern JS_PUBLIC_API(bool)
SetEntries(JSContext *cx, HandleObject obj, MutableHandleValue rval);
extern JS_PUBLIC_API(bool)
SetForEach(JSContext *cx, HandleObject obj, HandleValue callbackFn, HandleValue thisVal);
} /* namespace JS */
/*
* Dates.
*/
extern JS_PUBLIC_API(JSObject*)
JS_NewDateObject(JSContext* cx, int year, int mon, int mday, int hour, int min, int sec);
/**
* Returns true and sets |*isDate| indicating whether |obj| is a Date object or
* a wrapper around one, otherwise returns false on failure.
*
* This method returns true with |*isDate == false| when passed a proxy whose
* target is a Date, or when passed a revoked proxy.
*/
extern JS_PUBLIC_API(bool)
JS_ObjectIsDate(JSContext* cx, JS::HandleObject obj, bool* isDate);
/************************************************************************/
/*
* Regular Expressions.
*/
#define JSREG_FOLD 0x01u /* fold uppercase to lowercase */
#define JSREG_GLOB 0x02u /* global exec, creates array of matches */
#define JSREG_MULTILINE 0x04u /* treat ^ and $ as begin and end of line */
#define JSREG_STICKY 0x08u /* only match starting at lastIndex */
#define JSREG_UNICODE 0x10u /* unicode */
extern JS_PUBLIC_API(JSObject*)
JS_NewRegExpObject(JSContext* cx, const char* bytes, size_t length, unsigned flags);
extern JS_PUBLIC_API(JSObject*)
JS_NewUCRegExpObject(JSContext* cx, const char16_t* chars, size_t length, unsigned flags);
extern JS_PUBLIC_API(bool)
JS_SetRegExpInput(JSContext* cx, JS::HandleObject obj, JS::HandleString input);
extern JS_PUBLIC_API(bool)
JS_ClearRegExpStatics(JSContext* cx, JS::HandleObject obj);
extern JS_PUBLIC_API(bool)
JS_ExecuteRegExp(JSContext* cx, JS::HandleObject obj, JS::HandleObject reobj,
char16_t* chars, size_t length, size_t* indexp, bool test,
JS::MutableHandleValue rval);
/* RegExp interface for clients without a global object. */
extern JS_PUBLIC_API(bool)
JS_ExecuteRegExpNoStatics(JSContext* cx, JS::HandleObject reobj, char16_t* chars, size_t length,
size_t* indexp, bool test, JS::MutableHandleValue rval);
/**
* Returns true and sets |*isRegExp| indicating whether |obj| is a RegExp
* object or a wrapper around one, otherwise returns false on failure.
*
* This method returns true with |*isRegExp == false| when passed a proxy whose
* target is a RegExp, or when passed a revoked proxy.
*/
extern JS_PUBLIC_API(bool)
JS_ObjectIsRegExp(JSContext* cx, JS::HandleObject obj, bool* isRegExp);
extern JS_PUBLIC_API(unsigned)
JS_GetRegExpFlags(JSContext* cx, JS::HandleObject obj);
extern JS_PUBLIC_API(JSString*)
JS_GetRegExpSource(JSContext* cx, JS::HandleObject obj);
/************************************************************************/
extern JS_PUBLIC_API(bool)
JS_IsExceptionPending(JSContext* cx);
extern JS_PUBLIC_API(bool)
JS_GetPendingException(JSContext* cx, JS::MutableHandleValue vp);
extern JS_PUBLIC_API(void)
JS_SetPendingException(JSContext* cx, JS::HandleValue v);
extern JS_PUBLIC_API(void)
JS_ClearPendingException(JSContext* cx);
namespace JS {
/**
* Save and later restore the current exception state of a given JSContext.
* This is useful for implementing behavior in C++ that's like try/catch
* or try/finally in JS.
*
* Typical usage:
*
* bool ok = JS::Evaluate(cx, ...);
* AutoSaveExceptionState savedExc(cx);
* ... cleanup that might re-enter JS ...
* return ok;
*/
class JS_PUBLIC_API(AutoSaveExceptionState)
{
private:
JSContext* context;
bool wasPropagatingForcedReturn;
bool wasOverRecursed;
bool wasThrowing;
RootedValue exceptionValue;
public:
/*
* Take a snapshot of cx's current exception state. Then clear any current
* pending exception in cx.
*/
explicit AutoSaveExceptionState(JSContext* cx);
/*
* If neither drop() nor restore() was called, restore the exception
* state only if no exception is currently pending on cx.
*/
~AutoSaveExceptionState();
/*
* Discard any stored exception state.
* If this is called, the destructor is a no-op.
*/
void drop() {
wasPropagatingForcedReturn = false;
wasOverRecursed = false;
wasThrowing = false;
exceptionValue.setUndefined();
}
/*
* Replace cx's exception state with the stored exception state. Then
* discard the stored exception state. If this is called, the
* destructor is a no-op.
*/
void restore();
};
} /* namespace JS */
/* Deprecated API. Use AutoSaveExceptionState instead. */
extern JS_PUBLIC_API(JSExceptionState*)
JS_SaveExceptionState(JSContext* cx);
extern JS_PUBLIC_API(void)
JS_RestoreExceptionState(JSContext* cx, JSExceptionState* state);
extern JS_PUBLIC_API(void)
JS_DropExceptionState(JSContext* cx, JSExceptionState* state);
/**
* If the given object is an exception object, the exception will have (or be
* able to lazily create) an error report struct, and this function will return
* the address of that struct. Otherwise, it returns nullptr. The lifetime
* of the error report struct that might be returned is the same as the
* lifetime of the exception object.
*/
extern JS_PUBLIC_API(JSErrorReport*)
JS_ErrorFromException(JSContext* cx, JS::HandleObject obj);
namespace JS {
/**
* If the given object is an exception object (or an unwrappable
* cross-compartment wrapper for one), return the stack for that exception, if
* any. Will return null if the given object is not an exception object
* (including if it's null or a security wrapper that can't be unwrapped) or if
* the exception has no stack.
*/
extern JS_PUBLIC_API(JSObject*)
ExceptionStackOrNull(JS::HandleObject obj);
/**
* If this process is recording or replaying and the given value is an
* exception object (or an unwrappable cross-compartment wrapper for one),
* return the point where this exception was thrown, for time warping later.
* Returns zero otherwise.
*/
extern JS_PUBLIC_API(uint64_t)
ExceptionTimeWarpTarget(JS::HandleValue exn);
} /* namespace JS */
/**
* A JS context always has an "owner thread". The owner thread is set when the
* context is created (to the current thread) and practically all entry points
* into the JS engine check that a context (or anything contained in the
* context: runtime, compartment, object, etc) is only touched by its owner
* thread. Embeddings may check this invariant outside the JS engine by calling
* JS_AbortIfWrongThread (which will abort if not on the owner thread, even for
* non-debug builds).
*/
extern JS_PUBLIC_API(void)
JS_AbortIfWrongThread(JSContext* cx);
/************************************************************************/
/**
* A constructor can request that the JS engine create a default new 'this'
* object of the given class, using the callee to determine parentage and
* [[Prototype]].
*/
extern JS_PUBLIC_API(JSObject*)
JS_NewObjectForConstructor(JSContext* cx, const JSClass* clasp, const JS::CallArgs& args);
/************************************************************************/
#ifdef JS_GC_ZEAL
#define JS_DEFAULT_ZEAL_FREQ 100
extern JS_PUBLIC_API(void)
JS_GetGCZealBits(JSContext* cx, uint32_t* zealBits, uint32_t* frequency, uint32_t* nextScheduled);
extern JS_PUBLIC_API(void)
JS_SetGCZeal(JSContext* cx, uint8_t zeal, uint32_t frequency);
extern JS_PUBLIC_API(void)
JS_ScheduleGC(JSContext* cx, uint32_t count);
#endif
extern JS_PUBLIC_API(void)
JS_SetParallelParsingEnabled(JSContext* cx, bool enabled);
extern JS_PUBLIC_API(void)
JS_SetOffthreadIonCompilationEnabled(JSContext* cx, bool enabled);
#define JIT_COMPILER_OPTIONS(Register) \
Register(BASELINE_WARMUP_TRIGGER, "baseline.warmup.trigger") \
Register(ION_WARMUP_TRIGGER, "ion.warmup.trigger") \
Register(ION_GVN_ENABLE, "ion.gvn.enable") \
Register(ION_FORCE_IC, "ion.forceinlineCaches") \
Register(ION_ENABLE, "ion.enable") \
Register(ION_CHECK_RANGE_ANALYSIS, "ion.check-range-analysis") \
Register(BASELINE_ENABLE, "baseline.enable") \
Register(OFFTHREAD_COMPILATION_ENABLE, "offthread-compilation.enable") \
Register(FULL_DEBUG_CHECKS, "jit.full-debug-checks") \
Register(JUMP_THRESHOLD, "jump-threshold") \
Register(TRACK_OPTIMIZATIONS, "jit.track-optimizations") \
Register(SIMULATOR_ALWAYS_INTERRUPT, "simulator.always-interrupt") \
Register(SPECTRE_INDEX_MASKING, "spectre.index-masking") \
Register(SPECTRE_OBJECT_MITIGATIONS_BARRIERS, "spectre.object-mitigations.barriers") \
Register(SPECTRE_OBJECT_MITIGATIONS_MISC, "spectre.object-mitigations.misc") \
Register(SPECTRE_STRING_MITIGATIONS, "spectre.string-mitigations") \
Register(SPECTRE_VALUE_MASKING, "spectre.value-masking") \
Register(SPECTRE_JIT_TO_CXX_CALLS, "spectre.jit-to-C++-calls") \
Register(WASM_FOLD_OFFSETS, "wasm.fold-offsets") \
Register(WASM_DELAY_TIER2, "wasm.delay-tier2")
typedef enum JSJitCompilerOption {
#define JIT_COMPILER_DECLARE(key, str) \
JSJITCOMPILER_ ## key,
JIT_COMPILER_OPTIONS(JIT_COMPILER_DECLARE)
#undef JIT_COMPILER_DECLARE
JSJITCOMPILER_NOT_AN_OPTION
} JSJitCompilerOption;
extern JS_PUBLIC_API(void)
JS_SetGlobalJitCompilerOption(JSContext* cx, JSJitCompilerOption opt, uint32_t value);
extern JS_PUBLIC_API(bool)
JS_GetGlobalJitCompilerOption(JSContext* cx, JSJitCompilerOption opt, uint32_t* valueOut);
/**
* Convert a uint32_t index into a jsid.
*/
extern JS_PUBLIC_API(bool)
JS_IndexToId(JSContext* cx, uint32_t index, JS::MutableHandleId);
/**
* Convert chars into a jsid.
*
* |chars| may not be an index.
*/
extern JS_PUBLIC_API(bool)
JS_CharsToId(JSContext* cx, JS::TwoByteChars chars, JS::MutableHandleId);
/**
* Test if the given string is a valid ECMAScript identifier
*/
extern JS_PUBLIC_API(bool)
JS_IsIdentifier(JSContext* cx, JS::HandleString str, bool* isIdentifier);
/**
* Test whether the given chars + length are a valid ECMAScript identifier.
* This version is infallible, so just returns whether the chars are an
* identifier.
*/
extern JS_PUBLIC_API(bool)
JS_IsIdentifier(const char16_t* chars, size_t length);
namespace js {
class ScriptSource;
} // namespace js
namespace JS {
class MOZ_RAII JS_PUBLIC_API(AutoFilename)
{
private:
js::ScriptSource* ss_;
mozilla::Variant<const char*, UniqueChars> filename_;
AutoFilename(const AutoFilename&) = delete;
AutoFilename& operator=(const AutoFilename&) = delete;
public:
AutoFilename()
: ss_(nullptr),
filename_(mozilla::AsVariant<const char*>(nullptr))
{}
~AutoFilename() {
reset();
}
void reset();
void setOwned(UniqueChars&& filename);
void setUnowned(const char* filename);
void setScriptSource(js::ScriptSource* ss);
const char* get() const;
};
/**
* Return the current filename, line number and column number of the most
* currently running frame. Returns true if a scripted frame was found, false
* otherwise.
*
* If a the embedding has hidden the scripted caller for the topmost activation
* record, this will also return false.
*/
extern JS_PUBLIC_API(bool)
DescribeScriptedCaller(JSContext* cx, AutoFilename* filename = nullptr,
unsigned* lineno = nullptr, unsigned* column = nullptr);
extern JS_PUBLIC_API(JSObject*)
GetScriptedCallerGlobal(JSContext* cx);
/**
* Informs the JS engine that the scripted caller should be hidden. This can be
* used by the embedding to maintain an override of the scripted caller in its
* calculations, by hiding the scripted caller in the JS engine and pushing data
* onto a separate stack, which it inspects when DescribeScriptedCaller returns
* null.
*
* We maintain a counter on each activation record. Add() increments the counter
* of the topmost activation, and Remove() decrements it. The count may never
* drop below zero, and must always be exactly zero when the activation is
* popped from the stack.
*/
extern JS_PUBLIC_API(void)
HideScriptedCaller(JSContext* cx);
extern JS_PUBLIC_API(void)
UnhideScriptedCaller(JSContext* cx);
class MOZ_RAII AutoHideScriptedCaller
{
public:
explicit AutoHideScriptedCaller(JSContext* cx
MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
: mContext(cx)
{
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
HideScriptedCaller(mContext);
}
~AutoHideScriptedCaller() {
UnhideScriptedCaller(mContext);
}
protected:
JSContext* mContext;
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
};
/*
* Encode/Decode interpreted scripts and functions to/from memory.
*/
typedef mozilla::Vector<uint8_t> TranscodeBuffer;
typedef mozilla::Range<uint8_t> TranscodeRange;
struct TranscodeSource
{
TranscodeSource(const TranscodeRange& range_, const char* file, uint32_t line)
: range(range_), filename(file), lineno(line)
{}
const TranscodeRange range;
const char* filename;
const uint32_t lineno;
};
typedef mozilla::Vector<JS::TranscodeSource> TranscodeSources;
enum TranscodeResult: uint8_t
{
// Successful encoding / decoding.
TranscodeResult_Ok = 0,
// A warning message, is set to the message out-param.
TranscodeResult_Failure = 0x10,
TranscodeResult_Failure_BadBuildId = TranscodeResult_Failure | 0x1,
TranscodeResult_Failure_RunOnceNotSupported = TranscodeResult_Failure | 0x2,
TranscodeResult_Failure_AsmJSNotSupported = TranscodeResult_Failure | 0x3,
TranscodeResult_Failure_BadDecode = TranscodeResult_Failure | 0x4,
TranscodeResult_Failure_WrongCompileOption = TranscodeResult_Failure | 0x5,
TranscodeResult_Failure_NotInterpretedFun = TranscodeResult_Failure | 0x6,
// There is a pending exception on the context.
TranscodeResult_Throw = 0x20
};
extern JS_PUBLIC_API(TranscodeResult)
EncodeScript(JSContext* cx, TranscodeBuffer& buffer, JS::HandleScript script);
extern JS_PUBLIC_API(TranscodeResult)
EncodeInterpretedFunction(JSContext* cx, TranscodeBuffer& buffer, JS::HandleObject funobj);
extern JS_PUBLIC_API(TranscodeResult)
DecodeScript(JSContext* cx, TranscodeBuffer& buffer, JS::MutableHandleScript scriptp,
size_t cursorIndex = 0);
extern JS_PUBLIC_API(TranscodeResult)
DecodeScript(JSContext* cx, const TranscodeRange& range, JS::MutableHandleScript scriptp);
extern JS_PUBLIC_API(TranscodeResult)
DecodeInterpretedFunction(JSContext* cx, TranscodeBuffer& buffer, JS::MutableHandleFunction funp,
size_t cursorIndex = 0);
// Register an encoder on the given script source, such that all functions can
// be encoded as they are parsed. This strategy is used to avoid blocking the
// main thread in a non-interruptible way.
//
// The |script| argument of |StartIncrementalEncoding| and
// |FinishIncrementalEncoding| should be the top-level script returned either as
// an out-param of any of the |Compile| functions, or the result of
// |FinishOffThreadScript|.
//
// The |buffer| argument of |FinishIncrementalEncoding| is used for appending
// the encoded bytecode into the buffer. If any of these functions failed, the
// content of |buffer| would be undefined.
extern JS_PUBLIC_API(bool)
StartIncrementalEncoding(JSContext* cx, JS::HandleScript script);
extern JS_PUBLIC_API(bool)
FinishIncrementalEncoding(JSContext* cx, JS::HandleScript script, TranscodeBuffer& buffer);
} /* namespace JS */
namespace js {
enum class StackFormat { SpiderMonkey, V8, Default };
/*
* Sets the format used for stringifying Error stacks.
*
* The default format is StackFormat::SpiderMonkey. Use StackFormat::V8
* in order to emulate V8's stack formatting. StackFormat::Default can't be
* used here.
*/
extern JS_PUBLIC_API(void)
SetStackFormat(JSContext* cx, StackFormat format);
extern JS_PUBLIC_API(StackFormat)
GetStackFormat(JSContext* cx);
}
namespace JS {
/*
* This callback represents a request by the JS engine to open for reading the
* existing cache entry for the given global and char range that may contain a
* module. If a cache entry exists, the callback shall return 'true' and return
* the size, base address and an opaque file handle as outparams. If the
* callback returns 'true', the JS engine guarantees a call to
* CloseAsmJSCacheEntryForReadOp, passing the same base address, size and
* handle.
*/
using OpenAsmJSCacheEntryForReadOp =
bool (*)(HandleObject global, const char16_t* begin, const char16_t* limit, size_t* size,
const uint8_t** memory, intptr_t* handle);
using CloseAsmJSCacheEntryForReadOp =
void (*)(size_t size, const uint8_t* memory, intptr_t handle);
/** The list of reasons why an asm.js module may not be stored in the cache. */
enum AsmJSCacheResult
{
AsmJSCache_Success,
AsmJSCache_MIN = AsmJSCache_Success,
AsmJSCache_ModuleTooSmall,
AsmJSCache_SynchronousScript,
AsmJSCache_QuotaExceeded,
AsmJSCache_StorageInitFailure,
AsmJSCache_Disabled_Internal,
AsmJSCache_Disabled_ShellFlags,
AsmJSCache_Disabled_JitInspector,
AsmJSCache_InternalError,
AsmJSCache_Disabled_PrivateBrowsing,
AsmJSCache_LIMIT
};
/*
* This callback represents a request by the JS engine to open for writing a
* cache entry of the given size for the given global and char range containing
* the just-compiled module. If cache entry space is available, the callback
* shall return 'true' and return the base address and an opaque file handle as
* outparams. If the callback returns 'true', the JS engine guarantees a call
* to CloseAsmJSCacheEntryForWriteOp passing the same base address, size and
* handle.
*/
using OpenAsmJSCacheEntryForWriteOp =
AsmJSCacheResult (*)(HandleObject global, const char16_t* begin, const char16_t* end,
size_t size, uint8_t** memory, intptr_t* handle);
using CloseAsmJSCacheEntryForWriteOp =
void (*)(size_t size, uint8_t* memory, intptr_t handle);
struct AsmJSCacheOps
{
OpenAsmJSCacheEntryForReadOp openEntryForRead = nullptr;
CloseAsmJSCacheEntryForReadOp closeEntryForRead = nullptr;
OpenAsmJSCacheEntryForWriteOp openEntryForWrite = nullptr;
CloseAsmJSCacheEntryForWriteOp closeEntryForWrite = nullptr;
};
extern JS_PUBLIC_API(void)
SetAsmJSCacheOps(JSContext* cx, const AsmJSCacheOps* callbacks);
/**
* Return the buildId (represented as a sequence of characters) associated with
* the currently-executing build. If the JS engine is embedded such that a
* single cache entry can be observed by different compiled versions of the JS
* engine, it is critical that the buildId shall change for each new build of
* the JS engine.
*/
typedef js::Vector<char, 0, js::SystemAllocPolicy> BuildIdCharVector;
typedef bool
(* BuildIdOp)(BuildIdCharVector* buildId);
extern JS_PUBLIC_API(void)
SetBuildIdOp(JSContext* cx, BuildIdOp buildIdOp);
/**
* The WasmModule interface allows the embedding to hold a reference to the
* underying C++ implementation of a JS WebAssembly.Module object for purposes
* of efficient postMessage() and (de)serialization from a random thread.
*
* For postMessage() sharing:
*
* - GetWasmModule() is called when making a structured clone of payload
* containing a WebAssembly.Module object. The structured clone buffer holds a
* refcount of the JS::WasmModule until createObject() is called in the target
* agent's JSContext. The new WebAssembly.Module object continues to hold the
* JS::WasmModule and thus the final reference of a JS::WasmModule may be
* dropped from any thread and so the virtual destructor (and all internal
* methods of the C++ module) must be thread-safe.
*/
class WasmModuleListener
{
protected:
virtual ~WasmModuleListener() {}
public:
// These method signatures are chosen to exactly match nsISupports so that a
// plain nsISupports-implementing class can trivially implement this
// interface too. We can't simply #include "nsISupports.h" so we use MFBT
// equivalents for all the platform-dependent types.
virtual MozExternalRefCountType MOZ_XPCOM_ABI AddRef() = 0;
virtual MozExternalRefCountType MOZ_XPCOM_ABI Release() = 0;
virtual void onCompilationComplete() = 0;
};
struct WasmModule : js::AtomicRefCounted<WasmModule>
{
virtual ~WasmModule() {}
virtual JSObject* createObject(JSContext* cx) = 0;
};
extern JS_PUBLIC_API(bool)
IsWasmModuleObject(HandleObject obj);
extern JS_PUBLIC_API(RefPtr<WasmModule>)
GetWasmModule(HandleObject obj);
extern JS_PUBLIC_API(RefPtr<WasmModule>)
DeserializeWasmModule(PRFileDesc* bytecode, BuildIdCharVector&& buildId,
JS::UniqueChars filename, unsigned line);
/**
* Convenience class for imitating a JS level for-of loop. Typical usage:
*
* ForOfIterator it(cx);
* if (!it.init(iterable))
* return false;
* RootedValue val(cx);
* while (true) {
* bool done;
* if (!it.next(&val, &done))
* return false;
* if (done)
* break;
* if (!DoStuff(cx, val))
* return false;
* }
*/
class MOZ_STACK_CLASS JS_PUBLIC_API(ForOfIterator) {
protected:
JSContext* cx_;
/*
* Use the ForOfPIC on the global object (see vm/GlobalObject.h) to try
* to optimize iteration across arrays.
*
* Case 1: Regular Iteration
* iterator - pointer to the iterator object.
* nextMethod - value of |iterator|.next.
* index - fixed to NOT_ARRAY (== UINT32_MAX)
*
* Case 2: Optimized Array Iteration
* iterator - pointer to the array object.
* nextMethod - the undefined value.
* index - current position in array.
*
* The cases are distinguished by whether or not |index| is equal to NOT_ARRAY.
*/
JS::RootedObject iterator;
JS::RootedValue nextMethod;
uint32_t index;
static const uint32_t NOT_ARRAY = UINT32_MAX;
ForOfIterator(const ForOfIterator&) = delete;
ForOfIterator& operator=(const ForOfIterator&) = delete;
public:
explicit ForOfIterator(JSContext* cx)
: cx_(cx), iterator(cx_), nextMethod(cx), index(NOT_ARRAY)
{ }
enum NonIterableBehavior {
ThrowOnNonIterable,
AllowNonIterable
};
/**
* Initialize the iterator. If AllowNonIterable is passed then if getting
* the @@iterator property from iterable returns undefined init() will just
* return true instead of throwing. Callers must then check
* valueIsIterable() before continuing with the iteration.
*/
bool init(JS::HandleValue iterable,
NonIterableBehavior nonIterableBehavior = ThrowOnNonIterable);
/**
* Get the next value from the iterator. If false *done is true
* after this call, do not examine val.
*/
bool next(JS::MutableHandleValue val, bool* done);
/**
* Close the iterator.
* For the case that completion type is throw.
*/
void closeThrow();
/**
* If initialized with throwOnNonCallable = false, check whether
* the value is iterable.
*/
bool valueIsIterable() const {
return iterator;
}
private:
inline bool nextFromOptimizedArray(MutableHandleValue val, bool* done);
};
/**
* If a large allocation fails when calling pod_{calloc,realloc}CanGC, the JS
* engine may call the large-allocation-failure callback, if set, to allow the
* embedding to flush caches, possibly perform shrinking GCs, etc. to make some
* room. The allocation will then be retried (and may still fail.) This callback
* can be called on any thread and must be set at most once in a process.
*/
typedef void
(* LargeAllocationFailureCallback)();
extern JS_PUBLIC_API(void)
SetProcessLargeAllocationFailureCallback(LargeAllocationFailureCallback afc);
/**
* Unlike the error reporter, which is only called if the exception for an OOM
* bubbles up and is not caught, the OutOfMemoryCallback is called immediately
* at the OOM site to allow the embedding to capture the current state of heap
* allocation before anything is freed. If the large-allocation-failure callback
* is called at all (not all allocation sites call the large-allocation-failure
* callback on failure), it is called before the out-of-memory callback; the
* out-of-memory callback is only called if the allocation still fails after the
* large-allocation-failure callback has returned.
*/
typedef void
(* OutOfMemoryCallback)(JSContext* cx, void* data);
extern JS_PUBLIC_API(void)
SetOutOfMemoryCallback(JSContext* cx, OutOfMemoryCallback cb, void* data);
/**
* Capture all frames.
*/
struct AllFrames { };
/**
* Capture at most this many frames.
*/
struct MaxFrames
{
uint32_t maxFrames;
explicit MaxFrames(uint32_t max)
: maxFrames(max)
{
MOZ_ASSERT(max > 0);
}
};
/**
* Capture the first frame with the given principals. By default, do not
* consider self-hosted frames with the given principals as satisfying the stack
* capture.
*/
struct JS_PUBLIC_API(FirstSubsumedFrame)
{
JSContext* cx;
JSPrincipals* principals;
bool ignoreSelfHosted;
/**
* Use the cx's current compartment's principals.
*/
explicit FirstSubsumedFrame(JSContext* cx, bool ignoreSelfHostedFrames = true);
explicit FirstSubsumedFrame(JSContext* ctx, JSPrincipals* p, bool ignoreSelfHostedFrames = true)
: cx(ctx)
, principals(p)
, ignoreSelfHosted(ignoreSelfHostedFrames)
{
if (principals)
JS_HoldPrincipals(principals);
}
// No copying because we want to avoid holding and dropping principals
// unnecessarily.
FirstSubsumedFrame(const FirstSubsumedFrame&) = delete;
FirstSubsumedFrame& operator=(const FirstSubsumedFrame&) = delete;
FirstSubsumedFrame(FirstSubsumedFrame&& rhs)
: principals(rhs.principals)
, ignoreSelfHosted(rhs.ignoreSelfHosted)
{
MOZ_ASSERT(this != &rhs, "self move disallowed");
rhs.principals = nullptr;
}
FirstSubsumedFrame& operator=(FirstSubsumedFrame&& rhs) {
new (this) FirstSubsumedFrame(std::move(rhs));
return *this;
}
~FirstSubsumedFrame() {
if (principals)
JS_DropPrincipals(cx, principals);
}
};
using StackCapture = mozilla::Variant<AllFrames, MaxFrames, FirstSubsumedFrame>;
/**
* Capture the current call stack as a chain of SavedFrame JSObjects, and set
* |stackp| to the SavedFrame for the youngest stack frame, or nullptr if there
* are no JS frames on the stack.
*
* The |capture| parameter describes the portion of the JS stack to capture:
*
* * |JS::AllFrames|: Capture all frames on the stack.
*
* * |JS::MaxFrames|: Capture no more than |JS::MaxFrames::maxFrames| from the
* stack.
*
* * |JS::FirstSubsumedFrame|: Capture the first frame whose principals are
* subsumed by |JS::FirstSubsumedFrame::principals|. By default, do not
* consider self-hosted frames; this can be controlled via the
* |JS::FirstSubsumedFrame::ignoreSelfHosted| flag. Do not capture any async
* stack.
*/
extern JS_PUBLIC_API(bool)
CaptureCurrentStack(JSContext* cx, MutableHandleObject stackp,
StackCapture&& capture = StackCapture(AllFrames()));
/*
* This is a utility function for preparing an async stack to be used
* by some other object. This may be used when you need to treat a
* given stack trace as an async parent. If you just need to capture
* the current stack, async parents and all, use CaptureCurrentStack
* instead.
*
* Here |asyncStack| is the async stack to prepare. It is copied into
* |cx|'s current compartment, and the newest frame is given
* |asyncCause| as its asynchronous cause. If |maxFrameCount| is
* |Some(n)|, capture at most the youngest |n| frames. The
* new stack object is written to |stackp|. Returns true on success,
* or sets an exception and returns |false| on error.
*/
extern JS_PUBLIC_API(bool)
CopyAsyncStack(JSContext* cx, HandleObject asyncStack,
HandleString asyncCause, MutableHandleObject stackp,
const mozilla::Maybe<size_t>& maxFrameCount);
/*
* Accessors for working with SavedFrame JSObjects
*
* Each of these functions assert that if their `HandleObject savedFrame`
* argument is non-null, its JSClass is the SavedFrame class (or it is a
* cross-compartment or Xray wrapper around an object with the SavedFrame class)
* and the object is not the SavedFrame.prototype object.
*
* Each of these functions will find the first SavedFrame object in the chain
* whose underlying stack frame principals are subsumed by the given
* |principals|, and operate on that SavedFrame object. This prevents leaking
* information about privileged frames to un-privileged callers
*
* The SavedFrame in parameters do _NOT_ need to be in the same compartment as
* the cx, and the various out parameters are _NOT_ guaranteed to be in the same
* compartment as cx.
*
* You may consider or skip over self-hosted frames by passing
* `SavedFrameSelfHosted::Include` or `SavedFrameSelfHosted::Exclude`
* respectively.
*
* Additionally, it may be the case that there is no such SavedFrame object
* whose captured frame's principals are subsumed by |principals|! If the
* `HandleObject savedFrame` argument is null, or the |principals| do not
* subsume any of the chained SavedFrame object's principals,
* `SavedFrameResult::AccessDenied` is returned and a (hopefully) sane default
* value is chosen for the out param.
*
* See also `js/src/doc/SavedFrame/SavedFrame.md`.
*/
enum class SavedFrameResult {
Ok,
AccessDenied
};
enum class SavedFrameSelfHosted {
Include,
Exclude
};
/**
* Given a SavedFrame JSObject, get its source property. Defaults to the empty
* string.
*/
extern JS_PUBLIC_API(SavedFrameResult)
GetSavedFrameSource(JSContext* cx, JSPrincipals* principals, HandleObject savedFrame,
MutableHandleString sourcep,
SavedFrameSelfHosted selfHosted = SavedFrameSelfHosted::Include);
/**
* Given a SavedFrame JSObject, get its line property. Defaults to 0.
*/
extern JS_PUBLIC_API(SavedFrameResult)
GetSavedFrameLine(JSContext* cx, JSPrincipals* principals, HandleObject savedFrame,
uint32_t* linep,
SavedFrameSelfHosted selfHosted = SavedFrameSelfHosted::Include);
/**
* Given a SavedFrame JSObject, get its column property. Defaults to 0.
*/
extern JS_PUBLIC_API(SavedFrameResult)
GetSavedFrameColumn(JSContext* cx, JSPrincipals* principals, HandleObject savedFrame,
uint32_t* columnp,
SavedFrameSelfHosted selfHosted = SavedFrameSelfHosted::Include);
/**
* Given a SavedFrame JSObject, get its functionDisplayName string, or nullptr
* if SpiderMonkey was unable to infer a name for the captured frame's
* function. Defaults to nullptr.
*/
extern JS_PUBLIC_API(SavedFrameResult)
GetSavedFrameFunctionDisplayName(JSContext* cx, JSPrincipals* principals, HandleObject savedFrame,
MutableHandleString namep,
SavedFrameSelfHosted selfHosted = SavedFrameSelfHosted::Include);
/**
* Given a SavedFrame JSObject, get its asyncCause string. Defaults to nullptr.
*/
extern JS_PUBLIC_API(SavedFrameResult)
GetSavedFrameAsyncCause(JSContext* cx, JSPrincipals* principals, HandleObject savedFrame,
MutableHandleString asyncCausep,
SavedFrameSelfHosted selfHosted = SavedFrameSelfHosted::Include);
/**
* Given a SavedFrame JSObject, get its asyncParent SavedFrame object or nullptr
* if there is no asyncParent. The `asyncParentp` out parameter is _NOT_
* guaranteed to be in the cx's compartment. Defaults to nullptr.
*/
extern JS_PUBLIC_API(SavedFrameResult)
GetSavedFrameAsyncParent(JSContext* cx, JSPrincipals* principals, HandleObject savedFrame,
MutableHandleObject asyncParentp,
SavedFrameSelfHosted selfHosted = SavedFrameSelfHosted::Include);
/**
* Given a SavedFrame JSObject, get its parent SavedFrame object or nullptr if
* it is the oldest frame in the stack. The `parentp` out parameter is _NOT_
* guaranteed to be in the cx's compartment. Defaults to nullptr.
*/
extern JS_PUBLIC_API(SavedFrameResult)
GetSavedFrameParent(JSContext* cx, JSPrincipals* principals, HandleObject savedFrame,
MutableHandleObject parentp,
SavedFrameSelfHosted selfHosted = SavedFrameSelfHosted::Include);
/**
* Given a SavedFrame JSObject stack, stringify it in the same format as
* Error.prototype.stack. The stringified stack out parameter is placed in the
* cx's compartment. Defaults to the empty string.
*
* The same notes above about SavedFrame accessors applies here as well: cx
* doesn't need to be in stack's compartment, and stack can be null, a
* SavedFrame object, or a wrapper (CCW or Xray) around a SavedFrame object.
* SavedFrames not subsumed by |principals| are skipped.
*
* Optional indent parameter specifies the number of white spaces to indent
* each line.
*/
extern JS_PUBLIC_API(bool)
BuildStackString(JSContext* cx, JSPrincipals* principals, HandleObject stack,
MutableHandleString stringp, size_t indent = 0,
js::StackFormat stackFormat = js::StackFormat::Default);
/**
* Return true iff the given object is either a SavedFrame object or wrapper
* around a SavedFrame object, and it is not the SavedFrame.prototype object.
*/
extern JS_PUBLIC_API(bool)
IsMaybeWrappedSavedFrame(JSObject* obj);
/**
* Return true iff the given object is a SavedFrame object and not the
* SavedFrame.prototype object.
*/
extern JS_PUBLIC_API(bool)
IsUnwrappedSavedFrame(JSObject* obj);
} /* namespace JS */
/* Stopwatch-based performance monitoring. */
namespace js {
class AutoStopwatch;
/**
* Abstract base class for a representation of the performance of a
* component. Embeddings interested in performance monitoring should
* provide a concrete implementation of this class, as well as the
* relevant callbacks (see below).
*/
struct JS_PUBLIC_API(PerformanceGroup) {
PerformanceGroup();
// The current iteration of the event loop.
uint64_t iteration() const;
// `true` if an instance of `AutoStopwatch` is already monitoring
// the performance of this performance group for this iteration
// of the event loop, `false` otherwise.
bool isAcquired(uint64_t it) const;
// `true` if a specific instance of `AutoStopwatch` is already monitoring
// the performance of this performance group for this iteration
// of the event loop, `false` otherwise.
bool isAcquired(uint64_t it, const AutoStopwatch* owner) const;
// Mark that an instance of `AutoStopwatch` is monitoring
// the performance of this group for a given iteration.
void acquire(uint64_t it, const AutoStopwatch* owner);
// Mark that no `AutoStopwatch` is monitoring the
// performance of this group for the iteration.
void release(uint64_t it, const AutoStopwatch* owner);
// The number of cycles spent in this group during this iteration
// of the event loop. Note that cycles are not a reliable measure,
// especially over short intervals. See Stopwatch.* for a more
// complete discussion on the imprecision of cycle measurement.
uint64_t recentCycles(uint64_t iteration) const;
void addRecentCycles(uint64_t iteration, uint64_t cycles);
// The number of times this group has been activated during this
// iteration of the event loop.
uint64_t recentTicks(uint64_t iteration) const;
void addRecentTicks(uint64_t iteration, uint64_t ticks);
// The number of microseconds spent doing CPOW during this
// iteration of the event loop.
uint64_t recentCPOW(uint64_t iteration) const;
void addRecentCPOW(uint64_t iteration, uint64_t CPOW);
// Get rid of any data that pretends to be recent.
void resetRecentData();
// `true` if new measures should be added to this group, `false`
// otherwise.
bool isActive() const;
void setIsActive(bool);
// `true` if this group has been used in the current iteration,
// `false` otherwise.
bool isUsedInThisIteration() const;
void setIsUsedInThisIteration(bool);
protected:
// An implementation of `delete` for this object. Must be provided
// by the embedding.
virtual void Delete() = 0;
private:
// The number of cycles spent in this group during this iteration
// of the event loop. Note that cycles are not a reliable measure,
// especially over short intervals. See Runtime.cpp for a more
// complete discussion on the imprecision of cycle measurement.
uint64_t recentCycles_;
// The number of times this group has been activated during this
// iteration of the event loop.
uint64_t recentTicks_;
// The number of microseconds spent doing CPOW during this
// iteration of the event loop.
uint64_t recentCPOW_;
// The current iteration of the event loop. If necessary,
// may safely overflow.
uint64_t iteration_;
// `true` if new measures should be added to this group, `false`
// otherwise.
bool isActive_;
// `true` if this group has been used in the current iteration,
// `false` otherwise.
bool isUsedInThisIteration_;
// The stopwatch currently monitoring the group,
// or `nullptr` if none. Used ony for comparison.
const AutoStopwatch* owner_;
public:
// Compatibility with RefPtr<>
void AddRef();
void Release();
uint64_t refCount_;
};
using PerformanceGroupVector = mozilla::Vector<RefPtr<js::PerformanceGroup>, 8, SystemAllocPolicy>;
/**
* Commit any Performance Monitoring data.
*
* Until `FlushMonitoring` has been called, all PerformanceMonitoring data is invisible
* to the outside world and can cancelled with a call to `ResetMonitoring`.
*/
extern JS_PUBLIC_API(bool)
FlushPerformanceMonitoring(JSContext*);
/**
* Cancel any measurement that hasn't been committed.
*/
extern JS_PUBLIC_API(void)
ResetPerformanceMonitoring(JSContext*);
/**
* Cleanup any memory used by performance monitoring.
*/
extern JS_PUBLIC_API(void)
DisposePerformanceMonitoring(JSContext*);
/**
* Turn on/off stopwatch-based CPU monitoring.
*
* `SetStopwatchIsMonitoringCPOW` or `SetStopwatchIsMonitoringJank`
* may return `false` if monitoring could not be activated, which may
* happen if we are out of memory.
*/
extern JS_PUBLIC_API(bool)
SetStopwatchIsMonitoringCPOW(JSContext*, bool);
extern JS_PUBLIC_API(bool)
GetStopwatchIsMonitoringCPOW(JSContext*);
extern JS_PUBLIC_API(bool)
SetStopwatchIsMonitoringJank(JSContext*, bool);
extern JS_PUBLIC_API(bool)
GetStopwatchIsMonitoringJank(JSContext*);
// Extract the CPU rescheduling data.
extern JS_PUBLIC_API(void)
GetPerfMonitoringTestCpuRescheduling(JSContext*, uint64_t* stayed, uint64_t* moved);
/**
* Add a number of microseconds to the time spent waiting on CPOWs
* since process start.
*/
extern JS_PUBLIC_API(void)
AddCPOWPerformanceDelta(JSContext*, uint64_t delta);
typedef bool
(*StopwatchStartCallback)(uint64_t, void*);
extern JS_PUBLIC_API(bool)
SetStopwatchStartCallback(JSContext*, StopwatchStartCallback, void*);
typedef bool
(*StopwatchCommitCallback)(uint64_t, PerformanceGroupVector&, void*);
extern JS_PUBLIC_API(bool)
SetStopwatchCommitCallback(JSContext*, StopwatchCommitCallback, void*);
typedef bool
(*GetGroupsCallback)(JSContext*, PerformanceGroupVector&, void*);
extern JS_PUBLIC_API(bool)
SetGetPerformanceGroupsCallback(JSContext*, GetGroupsCallback, void*);
/**
* Hint that we expect a crash. Currently, the only thing that cares is the
* breakpad injector, which (if loaded) will suppress minidump generation.
*/
extern JS_PUBLIC_API(void)
NoteIntentionalCrash();
} /* namespace js */
namespace js {
enum class CompletionKind {
Normal,
Return,
Throw
};
} /* namespace js */
#endif /* jsapi_h */