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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 */
/* JS script descriptor. */
#ifndef jsscript_h
#define jsscript_h
#include "mozilla/Atomics.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/PodOperations.h"
#include "mozilla/UniquePtr.h"
#include "jsatom.h"
#include "jslock.h"
#include "jsopcode.h"
#include "jstypes.h"
#include "gc/Barrier.h"
#include "gc/Rooting.h"
#include "jit/IonCode.h"
#include "js/UbiNode.h"
#include "vm/NativeObject.h"
#include "vm/Shape.h"
namespace JS {
struct ScriptSourceInfo;
} // namespace JS
namespace js {
namespace jit {
struct BaselineScript;
struct IonScriptCounts;
} // namespace jit
# define ION_DISABLED_SCRIPT ((js::jit::IonScript*)0x1)
# define ION_COMPILING_SCRIPT ((js::jit::IonScript*)0x2)
# define ION_PENDING_SCRIPT ((js::jit::IonScript*)0x3)
# define BASELINE_DISABLED_SCRIPT ((js::jit::BaselineScript*)0x1)
class BreakpointSite;
class BindingIter;
class Debugger;
class LazyScript;
class ModuleObject;
class NestedScopeObject;
class RegExpObject;
struct SourceCompressionTask;
class Shape;
namespace frontend {
struct BytecodeEmitter;
class UpvarCookie;
class FunctionBox;
class ModuleBox;
} // namespace frontend
namespace detail {
// Do not call this directly! It is exposed for the friend declarations in
// this file.
CopyScript(JSContext* cx, HandleObject scriptStaticScope, HandleScript src, HandleScript dst);
} // namespace detail
} // namespace js
* Type of try note associated with each catch or finally block, and also with
* for-in and other kinds of loops. Non-for-in loops do not need these notes
* for exception unwinding, but storing their boundaries here is helpful for
* heuristics that need to know whether a given op is inside a loop.
enum JSTryNoteKind {
* Exception handling record.
struct JSTryNote {
uint8_t kind; /* one of JSTryNoteKind */
uint32_t stackDepth; /* stack depth upon exception handler entry */
uint32_t start; /* start of the try statement or loop
relative to script->main */
uint32_t length; /* length of the try statement or loop */
namespace js {
// A block scope has a range in bytecode: it is entered at some offset, and left
// at some later offset. Scopes can be nested. Given an offset, the
// BlockScopeNote containing that offset whose with the highest start value
// indicates the block scope. The block scope list is sorted by increasing
// start value.
// It is possible to leave a scope nonlocally, for example via a "break"
// statement, so there may be short bytecode ranges in a block scope in which we
// are popping the block chain in preparation for a goto. These exits are also
// nested with respect to outer scopes. The scopes in these exits are indicated
// by the "index" field, just like any other block. If a nonlocal exit pops the
// last block scope, the index will be NoBlockScopeIndex.
struct BlockScopeNote {
static const uint32_t NoBlockScopeIndex = UINT32_MAX;
uint32_t index; // Index of NestedScopeObject in the object
// array, or NoBlockScopeIndex if there is no
// block scope in this range.
uint32_t start; // Bytecode offset at which this scope starts,
// from script->main().
uint32_t length; // Bytecode length of scope.
uint32_t parent; // Index of parent block scope in notes, or UINT32_MAX.
struct ConstArray {
js::HeapValue* vector; /* array of indexed constant values */
uint32_t length;
struct ObjectArray {
js::HeapPtrObject* vector; // Array of indexed objects.
uint32_t length; // Count of indexed objects.
struct TryNoteArray {
JSTryNote* vector; // Array of indexed try notes.
uint32_t length; // Count of indexed try notes.
struct BlockScopeArray {
BlockScopeNote* vector; // Array of indexed BlockScopeNote records.
uint32_t length; // Count of indexed try notes.
class YieldOffsetArray {
friend bool
detail::CopyScript(JSContext* cx, HandleObject scriptStaticScope, HandleScript src,
HandleScript dst);
uint32_t* vector_; // Array of bytecode offsets.
uint32_t length_; // Count of bytecode offsets.
void init(uint32_t* vector, uint32_t length) {
vector_ = vector;
length_ = length;
uint32_t& operator[](uint32_t index) {
MOZ_ASSERT(index < length_);
return vector_[index];
uint32_t length() const {
return length_;
class Binding : public JS::Traceable
// One JSScript stores one Binding per formal/variable so we use a
// packed-word representation.
uintptr_t bits_;
static const uintptr_t KIND_MASK = 0x3;
static const uintptr_t ALIASED_BIT = 0x4;
static const uintptr_t NAME_MASK = ~(KIND_MASK | ALIASED_BIT);
// A "binding" is a formal parameter, 'var' (also a stand in for
// body-level 'let' declarations), or 'const' declaration. A function's
// lexical scope is composed of these three kinds of bindings.
explicit Binding() : bits_(0) {}
Binding(PropertyName* name, Kind kind, bool aliased) {
MOZ_ASSERT((uintptr_t(name) & ~NAME_MASK) == 0);
MOZ_ASSERT((uintptr_t(kind) & ~KIND_MASK) == 0);
bits_ = uintptr_t(name) | uintptr_t(kind) | (aliased ? ALIASED_BIT : 0);
PropertyName* name() const {
return (PropertyName*)(bits_ & NAME_MASK);
Kind kind() const {
return Kind(bits_ & KIND_MASK);
bool aliased() const {
return bool(bits_ & ALIASED_BIT);
static void trace(Binding* self, JSTracer* trc) { self->trace(trc); }
void trace(JSTracer* trc);
JS_STATIC_ASSERT(sizeof(Binding) == sizeof(uintptr_t));
* Formal parameters and local variables are stored in a shape tree
* path encapsulated within this class. This class represents bindings for
* both function and top-level scripts (the latter is needed to track names in
* strict mode eval code, to give such code its own lexical environment).
class Bindings : public JS::Traceable
friend class BindingIter;
friend class AliasedFormalIter;
template <typename Outer> friend class BindingsOperations;
template <typename Outer> friend class MutableBindingsOperations;
RelocatablePtrShape callObjShape_;
uintptr_t bindingArrayAndFlag_;
uint16_t numArgs_;
uint16_t numBlockScoped_;
uint16_t numBodyLevelLexicals_;
uint16_t numUnaliasedBodyLevelLexicals_;
uint32_t aliasedBodyLevelLexicalBegin_;
uint32_t numVars_;
uint32_t numUnaliasedVars_;
#if JS_BITS_PER_WORD == 32
// Bindings is allocated inline inside JSScript, which needs to be
// gc::Cell aligned.
uint32_t padding_;
* During parsing, bindings are allocated out of a temporary LifoAlloc.
* After parsing, a JSScript object is created and the bindings are
* permanently transferred to it. On error paths, the JSScript object may
* end up with bindings that still point to the (new released) LifoAlloc
* memory. To avoid tracing these bindings during GC, we keep track of
* whether the bindings are temporary or permanent in the low bit of
* bindingArrayAndFlag_.
static const uintptr_t TEMPORARY_STORAGE_BIT = 0x1;
bool bindingArrayUsingTemporaryStorage() const {
return bindingArrayAndFlag_ & TEMPORARY_STORAGE_BIT;
Binding* bindingArray() const {
return reinterpret_cast<Binding*>(bindingArrayAndFlag_ & ~TEMPORARY_STORAGE_BIT);
: callObjShape_(nullptr), bindingArrayAndFlag_(TEMPORARY_STORAGE_BIT),
numArgs_(0), numBlockScoped_(0),
numBodyLevelLexicals_(0), numUnaliasedBodyLevelLexicals_(0),
numVars_(0), numUnaliasedVars_(0)
* Initialize a Bindings with a pointer into temporary storage.
* bindingArray must have length numArgs + numVars +
* numBodyLevelLexicals. Before the temporary storage is release,
* switchToScriptStorage must be called, providing a pointer into the
* Binding array stored in script->data.
static bool initWithTemporaryStorage(ExclusiveContext* cx, MutableHandle<Bindings> self,
uint32_t numArgs,
uint32_t numVars,
uint32_t numBodyLevelLexicals,
uint32_t numBlockScoped,
uint32_t numUnaliasedVars,
uint32_t numUnaliasedBodyLevelLexicals,
const Binding* bindingArray,
bool isModule = false);
// Initialize a trivial Bindings with no slots and an empty callObjShape.
bool initTrivial(ExclusiveContext* cx);
// CompileScript parses and compiles one statement at a time, but the result
// is one Script object. There will be no vars or bindings, because those
// go on the global, but there may be block-scoped locals, and the number of
// block-scoped locals may increase as we parse more expressions. This
// helper updates the number of block scoped variables in a script as it is
// being parsed.
void updateNumBlockScoped(unsigned numBlockScoped) {
MOZ_ASSERT(numVars_ == 0);
MOZ_ASSERT(numBlockScoped >= numBlockScoped_);
numBlockScoped_ = numBlockScoped;
void setAllLocalsAliased() {
numBlockScoped_ = 0;
uint8_t* switchToScriptStorage(Binding* newStorage);
* Clone srcScript's bindings (as part of js::CloneScript). dstScriptData
* is the pointer to what will eventually be dstScript->data.
static bool clone(JSContext* cx, MutableHandle<Bindings> self, uint8_t* dstScriptData,
HandleScript srcScript);
uint32_t numArgs() const { return numArgs_; }
uint32_t numVars() const { return numVars_; }
uint32_t numBodyLevelLexicals() const { return numBodyLevelLexicals_; }
uint32_t numBlockScoped() const { return numBlockScoped_; }
uint32_t numBodyLevelLocals() const { return numVars_ + numBodyLevelLexicals_; }
uint32_t numUnaliasedBodyLevelLocals() const { return numUnaliasedVars_ + numUnaliasedBodyLevelLexicals_; }
uint32_t numAliasedBodyLevelLocals() const { return numBodyLevelLocals() - numUnaliasedBodyLevelLocals(); }
uint32_t numLocals() const { return numVars() + numBodyLevelLexicals() + numBlockScoped(); }
uint32_t numFixedLocals() const { return numUnaliasedVars() + numUnaliasedBodyLevelLexicals() + numBlockScoped(); }
uint32_t lexicalBegin() const { return numArgs() + numVars(); }
uint32_t aliasedBodyLevelLexicalBegin() const { return aliasedBodyLevelLexicalBegin_; }
uint32_t numUnaliasedVars() const { return numUnaliasedVars_; }
uint32_t numUnaliasedBodyLevelLexicals() const { return numUnaliasedBodyLevelLexicals_; }
// Return the size of the bindingArray.
uint32_t count() const { return numArgs() + numVars() + numBodyLevelLexicals(); }
/* Return the initial shape of call objects created for this scope. */
Shape* callObjShape() const { return callObjShape_; }
/* Convenience method to get the var index of 'arguments' or 'this'. */
static BindingIter argumentsBinding(ExclusiveContext* cx, HandleScript script);
static BindingIter thisBinding(ExclusiveContext* cx, HandleScript script);
/* Return whether the binding at bindingIndex is aliased. */
bool bindingIsAliased(uint32_t bindingIndex);
/* Return whether this scope has any aliased bindings. */
bool hasAnyAliasedBindings() const {
if (!callObjShape_)
return false;
return !callObjShape_->isEmptyShape();
Binding* begin() const { return bindingArray(); }
Binding* end() const { return bindingArray() + count(); }
static void trace(Bindings* self, JSTracer* trc) { self->trace(trc); }
void trace(JSTracer* trc);
// If this fails, add/remove padding within Bindings.
static_assert(sizeof(Bindings) % js::gc::CellSize == 0,
"Size of Bindings must be an integral multiple of js::gc::CellSize");
template <class Outer>
class BindingsOperations
const Bindings& bindings() const { return static_cast<const Outer*>(this)->get(); }
// Direct data access to the underlying bindings.
const RelocatablePtrShape& callObjShape() const {
return bindings().callObjShape_;
uint16_t numArgs() const {
return bindings().numArgs_;
uint16_t numBlockScoped() const {
return bindings().numBlockScoped_;
uint16_t numBodyLevelLexicals() const {
return bindings().numBodyLevelLexicals_;
uint16_t aliasedBodyLevelLexicalBegin() const {
return bindings().aliasedBodyLevelLexicalBegin_;
uint16_t numUnaliasedBodyLevelLexicals() const {
return bindings().numUnaliasedBodyLevelLexicals_;
uint32_t numVars() const {
return bindings().numVars_;
uint32_t numUnaliasedVars() const {
return bindings().numUnaliasedVars_;
// Binding array access.
bool bindingArrayUsingTemporaryStorage() const {
return bindings().bindingArrayUsingTemporaryStorage();
const Binding* bindingArray() const {
return bindings().bindingArray();
uint32_t count() const {
return bindings().count();
// Helpers.
uint32_t numBodyLevelLocals() const {
return numVars() + numBodyLevelLexicals();
uint32_t numUnaliasedBodyLevelLocals() const {
return numUnaliasedVars() + numUnaliasedBodyLevelLexicals();
uint32_t numAliasedBodyLevelLocals() const {
return numBodyLevelLocals() - numUnaliasedBodyLevelLocals();
uint32_t numLocals() const {
return numVars() + numBodyLevelLexicals() + numBlockScoped();
uint32_t numFixedLocals() const {
return numUnaliasedVars() + numUnaliasedBodyLevelLexicals() + numBlockScoped();
uint32_t lexicalBegin() const {
return numArgs() + numVars();
template <class Outer>
class MutableBindingsOperations : public BindingsOperations<Outer>
Bindings& bindings() { return static_cast<Outer*>(this)->get(); }
void setCallObjShape(HandleShape shape) { bindings().callObjShape_ = shape; }
void setBindingArray(const Binding* bindingArray, uintptr_t temporaryBit) {
bindings().bindingArrayAndFlag_ = uintptr_t(bindingArray) | temporaryBit;
void setNumArgs(uint16_t num) { bindings().numArgs_ = num; }
void setNumVars(uint32_t num) { bindings().numVars_ = num; }
void setNumBodyLevelLexicals(uint16_t num) { bindings().numBodyLevelLexicals_ = num; }
void setNumBlockScoped(uint16_t num) { bindings().numBlockScoped_ = num; }
void setNumUnaliasedVars(uint32_t num) { bindings().numUnaliasedVars_ = num; }
void setNumUnaliasedBodyLevelLexicals(uint16_t num) {
bindings().numUnaliasedBodyLevelLexicals_ = num;
void setAliasedBodyLevelLexicalBegin(uint32_t offset) {
bindings().aliasedBodyLevelLexicalBegin_ = offset;
uint8_t* switchToScriptStorage(Binding* permanentStorage) {
return bindings().switchToScriptStorage(permanentStorage);
template <>
class HandleBase<Bindings> : public BindingsOperations<JS::Handle<Bindings>>
template <>
class MutableHandleBase<Bindings>
: public MutableBindingsOperations<JS::MutableHandle<Bindings>>
class ScriptCounts
typedef mozilla::Vector<PCCounts, 0, SystemAllocPolicy> PCCountsVector;
inline ScriptCounts();
inline explicit ScriptCounts(PCCountsVector&& jumpTargets);
inline ScriptCounts(ScriptCounts&& src);
inline ~ScriptCounts();
inline ScriptCounts& operator=(ScriptCounts&& src);
// Return the counter used to count the number of visits. Returns null if
// the element is not found.
PCCounts* maybeGetPCCounts(size_t offset);
const PCCounts* maybeGetPCCounts(size_t offset) const;
// PCCounts are stored at jump-target offsets. This function looks for the
// previous PCCount which is in the same basic block as the current offset.
PCCounts* getImmediatePrecedingPCCounts(size_t offset);
// Return the counter used to count the number of throws. Returns null if
// the element is not found.
const PCCounts* maybeGetThrowCounts(size_t offset) const;
// Throw counts are stored at the location of each throwing
// instruction. This function looks for the previous throw count.
// Note: if the offset of the returned count is higher than the offset of
// the immediate preceding PCCount, then this throw happened in the same
// basic block.
const PCCounts* getImmediatePrecedingThrowCounts(size_t offset) const;
// Return the counter used to count the number of throws. Allocate it if
// none exists yet. Returns null if the allocation failed.
PCCounts* getThrowCounts(size_t offset);
friend class ::JSScript;
friend struct ScriptAndCounts;
// This sorted array is used to map an offset to the number of times a
// branch got visited.
PCCountsVector pcCounts_;
// This sorted vector is used to map an offset to the number of times an
// instruction throw.
PCCountsVector throwCounts_;
// Information about any Ion compilations for the script.
jit::IonScriptCounts* ionCounts_;
// Note: The key of this hash map is a weak reference to a JSScript. We do not
// use the WeakMap implementation provided in jsweakmap.h because it would be
// collected at the beginning of the sweeping of the compartment, thus before
// the calls to the JSScript::finalize function which are used to aggregate code
// coverage results on the compartment.
typedef HashMap<JSScript*,
SystemAllocPolicy> ScriptCountsMap;
class DebugScript
friend class ::JSScript;
* When non-zero, compile script in single-step mode. The top bit is set and
* cleared by setStepMode, as used by JSD. The lower bits are a count,
* adjusted by changeStepModeCount, used by the Debugger object. Only
* when the bit is clear and the count is zero may we compile the script
* without single-step support.
uint32_t stepMode;
* Number of breakpoint sites at opcodes in the script. This is the number
* of populated entries in DebugScript::breakpoints, below.
uint32_t numSites;
* Breakpoints set in our script. For speed and simplicity, this array is
* parallel to script->code(): the BreakpointSite for the opcode at
* script->code()[offset] is debugScript->breakpoints[offset]. Naturally,
* this array's true length is script->length().
BreakpointSite* breakpoints[1];
typedef HashMap<JSScript*,
SystemAllocPolicy> DebugScriptMap;
class ScriptSource;
class UncompressedSourceCache
typedef HashMap<ScriptSource*,
const char16_t*,
SystemAllocPolicy> Map;
// Hold an entry in the source data cache and prevent it from being purged on GC.
class AutoHoldEntry
UncompressedSourceCache* cache_;
ScriptSource* source_;
const char16_t* charsToFree_;
explicit AutoHoldEntry();
void holdEntry(UncompressedSourceCache* cache, ScriptSource* source);
void deferDelete(const char16_t* chars);
ScriptSource* source() const { return source_; }
friend class UncompressedSourceCache;
Map* map_;
AutoHoldEntry* holder_;
UncompressedSourceCache() : map_(nullptr), holder_(nullptr) {}
const char16_t* lookup(ScriptSource* ss, AutoHoldEntry& asp);
bool put(ScriptSource* ss, const char16_t* chars, AutoHoldEntry& asp);
void purge();
size_t sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf);
void holdEntry(AutoHoldEntry& holder, ScriptSource* ss);
void releaseEntry(AutoHoldEntry& holder);
class ScriptSource
friend struct SourceCompressionTask;
uint32_t refs;
// Note: while ScriptSources may be compressed off thread, they are only
// modified by the main thread, and all members are always safe to access
// on the main thread.
// Indicate which field in the |data| union is active.
enum {
} dataType;
union {
struct {
const char16_t* chars;
bool ownsChars;
} uncompressed;
struct {
void* raw;
size_t nbytes;
HashNumber hash;
} compressed;
ScriptSource* parent;
} data;
uint32_t length_;
// The filename of this script.
mozilla::UniquePtr<char[], JS::FreePolicy> filename_;
mozilla::UniquePtr<char16_t[], JS::FreePolicy> displayURL_;
mozilla::UniquePtr<char16_t[], JS::FreePolicy> sourceMapURL_;
bool mutedErrors_;
// bytecode offset in caller script that generated this code.
// This is present for eval-ed code, as well as "new Function(...)"-introduced
// scripts.
uint32_t introductionOffset_;
// If this ScriptSource was generated by a code-introduction mechanism such
// as |eval| or |new Function|, the debugger needs access to the "raw"
// filename of the top-level script that contains the eval-ing code. To
// keep track of this, we must preserve the original outermost filename (of
// the original introducer script), so that instead of a filename of
// "foo.js line 30 > eval line 10 > Function", we can obtain the original
// raw filename of "foo.js".
// In the case described above, this field will be non-null and will be the
// original raw filename from above. Otherwise this field will be null.
mozilla::UniquePtr<char[], JS::FreePolicy> introducerFilename_;
// A string indicating how this source code was introduced into the system.
// This accessor returns one of the following values:
// "eval" for code passed to |eval|.
// "Function" for code passed to the |Function| constructor.
// "Worker" for code loaded by calling the Web worker constructor&mdash;the worker's main script.
// "importScripts" for code by calling |importScripts| in a web worker.
// "handler" for code assigned to DOM elements' event handler IDL attributes.
// "scriptElement" for code belonging to <script> elements.
// undefined if the implementation doesn't know how the code was introduced.
// This is a constant, statically allocated C string, so does not need
// memory management.
const char* introductionType_;
// True if we can call JSRuntime::sourceHook to load the source on
// demand. If sourceRetrievable_ and hasSourceData() are false, it is not
// possible to get source at all.
bool sourceRetrievable_:1;
bool argumentsNotIncluded_:1;
bool hasIntroductionOffset_:1;
// Whether this is in the runtime's set of compressed ScriptSources.
bool inCompressedSourceSet:1;
explicit ScriptSource()
: refs(0),
void incref() { refs++; }
void decref() {
MOZ_ASSERT(refs != 0);
if (--refs == 0)
bool initFromOptions(ExclusiveContext* cx, const ReadOnlyCompileOptions& options);
bool setSourceCopy(ExclusiveContext* cx,
JS::SourceBufferHolder& srcBuf,
bool argumentsNotIncluded,
SourceCompressionTask* tok);
void setSourceRetrievable() { sourceRetrievable_ = true; }
bool sourceRetrievable() const { return sourceRetrievable_; }
bool hasSourceData() const { return dataType != DataMissing; }
bool hasCompressedSource() const { return dataType == DataCompressed; }
size_t length() const {
return length_;
bool argumentsNotIncluded() const {
return argumentsNotIncluded_;
const char16_t* chars(JSContext* cx, UncompressedSourceCache::AutoHoldEntry& asp);
JSFlatString* substring(JSContext* cx, uint32_t start, uint32_t stop);
JSFlatString* substringDontDeflate(JSContext* cx, uint32_t start, uint32_t stop);
void addSizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf,
JS::ScriptSourceInfo* info) const;
const char16_t* uncompressedChars() const {
MOZ_ASSERT(dataType == DataUncompressed);
return data.uncompressed.chars;
bool ownsUncompressedChars() const {
MOZ_ASSERT(dataType == DataUncompressed);
return data.uncompressed.ownsChars;
void* compressedData() const {
MOZ_ASSERT(dataType == DataCompressed);
return data.compressed.raw;
size_t compressedBytes() const {
MOZ_ASSERT(dataType == DataCompressed);
return data.compressed.nbytes;
HashNumber compressedHash() const {
MOZ_ASSERT(dataType == DataCompressed);
return data.compressed.hash;
ScriptSource* parent() const {
MOZ_ASSERT(dataType == DataParent);
return data.parent;
void setSource(const char16_t* chars, size_t length, bool ownsChars = true);
void setCompressedSource(JSRuntime* maybert, void* raw, size_t nbytes, HashNumber hash);
void updateCompressedSourceSet(JSRuntime* rt);
bool ensureOwnsSource(ExclusiveContext* cx);
// XDR handling
template <XDRMode mode>
bool performXDR(XDRState<mode>* xdr);
bool setFilename(ExclusiveContext* cx, const char* filename);
const char* introducerFilename() const {
return introducerFilename_ ? introducerFilename_.get() : filename_.get();
bool hasIntroductionType() const {
return introductionType_;
const char* introductionType() const {
return introductionType_;
const char* filename() const {
return filename_.get();
// Display URLs
bool setDisplayURL(ExclusiveContext* cx, const char16_t* displayURL);
bool hasDisplayURL() const { return displayURL_ != nullptr; }
const char16_t * displayURL() {
return displayURL_.get();
// Source maps
bool setSourceMapURL(ExclusiveContext* cx, const char16_t* sourceMapURL);
bool hasSourceMapURL() const { return sourceMapURL_ != nullptr; }
const char16_t * sourceMapURL() {
return sourceMapURL_.get();
bool mutedErrors() const { return mutedErrors_; }
bool hasIntroductionOffset() const { return hasIntroductionOffset_; }
uint32_t introductionOffset() const {
return introductionOffset_;
void setIntroductionOffset(uint32_t offset) {
MOZ_ASSERT(offset <= (uint32_t)INT32_MAX);
introductionOffset_ = offset;
hasIntroductionOffset_ = true;
size_t computedSizeOfData() const;
class ScriptSourceHolder
ScriptSource* ss;
explicit ScriptSourceHolder(ScriptSource* ss)
: ss(ss)
struct CompressedSourceHasher
typedef ScriptSource* Lookup;
static HashNumber computeHash(const void* data, size_t nbytes) {
return mozilla::HashBytes(data, nbytes);
static HashNumber hash(const ScriptSource* ss) {
return ss->compressedHash();
static bool match(const ScriptSource* a, const ScriptSource* b) {
return a->compressedBytes() == b->compressedBytes() &&
a->compressedHash() == b->compressedHash() &&
!memcmp(a->compressedData(), b->compressedData(), a->compressedBytes());
typedef HashSet<ScriptSource*, CompressedSourceHasher, SystemAllocPolicy> CompressedSourceSet;
class ScriptSourceObject : public NativeObject
static const Class class_;
static void trace(JSTracer* trc, JSObject* obj);
static void finalize(FreeOp* fop, JSObject* obj);
static ScriptSourceObject* create(ExclusiveContext* cx, ScriptSource* source);
// Initialize those properties of this ScriptSourceObject whose values
// are provided by |options|, re-wrapping as necessary.
static bool initFromOptions(JSContext* cx, HandleScriptSource source,
const ReadOnlyCompileOptions& options);
ScriptSource* source() const {
return static_cast<ScriptSource*>(getReservedSlot(SOURCE_SLOT).toPrivate());
JSObject* element() const {
return getReservedSlot(ELEMENT_SLOT).toObjectOrNull();
const Value& elementAttributeName() const {
return getReservedSlot(ELEMENT_PROPERTY_SLOT);
JSScript* introductionScript() const {
if (getReservedSlot(INTRODUCTION_SCRIPT_SLOT).isUndefined())
return nullptr;
void* untyped = getReservedSlot(INTRODUCTION_SCRIPT_SLOT).toPrivate();
return static_cast<JSScript*>(untyped);
static const uint32_t SOURCE_SLOT = 0;
static const uint32_t ELEMENT_SLOT = 1;
static const uint32_t ELEMENT_PROPERTY_SLOT = 2;
static const uint32_t INTRODUCTION_SCRIPT_SLOT = 3;
static const uint32_t RESERVED_SLOTS = 4;
enum GeneratorKind { NotGenerator, LegacyGenerator, StarGenerator };
static inline unsigned
GeneratorKindAsBits(GeneratorKind generatorKind) {
return static_cast<unsigned>(generatorKind);
static inline GeneratorKind
GeneratorKindFromBits(unsigned val) {
MOZ_ASSERT(val <= StarGenerator);
return static_cast<GeneratorKind>(val);
* NB: after a successful XDR_DECODE, XDRScript callers must do any required
* subsequent set-up of owning function or script object and then call
* CallNewScriptHook.
template<XDRMode mode>
XDRScript(XDRState<mode>* xdr, HandleObject enclosingScope, HandleScript enclosingScript,
HandleFunction fun, MutableHandleScript scriptp);
template<XDRMode mode>
XDRLazyScript(XDRState<mode>* xdr, HandleObject enclosingScope, HandleScript enclosingScript,
HandleFunction fun, MutableHandle<LazyScript*> lazy);
* Code any constant value.
template<XDRMode mode>
XDRScriptConst(XDRState<mode>* xdr, MutableHandleValue vp);
} /* namespace js */
class JSScript : public js::gc::TenuredCell
template <js::XDRMode mode>
js::XDRScript(js::XDRState<mode>* xdr, js::HandleObject enclosingScope,
js::HandleScript enclosingScript,
js::HandleFunction fun, js::MutableHandleScript scriptp);
friend bool
js::detail::CopyScript(JSContext* cx, js::HandleObject scriptStaticScope, js::HandleScript src,
js::HandleScript dst);
// We order fields according to their size in order to avoid wasting space
// for alignment.
// Larger-than-word-sized fields.
js::Bindings bindings; /* names of top-level variables in this script
(and arguments if this is a function script) */
bool hasAnyAliasedBindings() const {
return bindings.hasAnyAliasedBindings();
js::Binding* bindingArray() const {
return bindings.bindingArray();
unsigned numArgs() const {
return bindings.numArgs();
js::Shape* callObjShape() const {
return bindings.callObjShape();
// Word-sized fields.
jsbytecode* code_; /* bytecodes and their immediate operands */
uint8_t* data; /* pointer to variable-length data array (see
comment above Create() for details) */
js::HeapPtrAtom* atoms; /* maps immediate index to literal struct */
JSCompartment* compartment_;
/* Persistent type information retained across GCs. */
js::TypeScript* types_;
// This script's ScriptSourceObject, or a CCW thereof.
// (When we clone a JSScript into a new compartment, we don't clone its
// source object. Instead, the clone refers to a wrapper.)
js::HeapPtrObject sourceObject_;
js::HeapPtrFunction function_;
js::HeapPtr<js::ModuleObject*> module_;
js::HeapPtrObject enclosingStaticScope_;
* Information attached by Ion. Nexto a valid IonScript this could be
* The later is a ion compilation that is ready, but hasn't been linked
* yet.
js::jit::IonScript* ion;
/* Information attached by Baseline. */
js::jit::BaselineScript* baseline;
/* Information used to re-lazify a lazily-parsed interpreted function. */
js::LazyScript* lazyScript;
* Pointer to either baseline->method()->raw() or ion->method()->raw(), or
* nullptr if there's no Baseline or Ion script.
uint8_t* baselineOrIonRaw;
uint8_t* baselineOrIonSkipArgCheck;
// 32-bit fields.
uint32_t length_; /* length of code vector */
uint32_t dataSize_; /* size of the used part of the data array */
uint32_t lineno_; /* base line number of script */
uint32_t column_; /* base column of script, optionally set */
uint32_t mainOffset_;/* offset of main entry point from code, after
predef'ing prologue */
uint32_t natoms_; /* length of atoms array */
uint32_t nslots_; /* vars plus maximum stack depth */
/* Range of characters in scriptSource which contains this script's source. */
uint32_t sourceStart_;
uint32_t sourceEnd_;
uint32_t warmUpCount; /* Number of times the script has been called
* or has had backedges taken. When running in
* ion, also increased for any inlined scripts.
* Reset if the script's JIT code is forcibly
* discarded. */
// 16-bit fields.
uint16_t warmUpResetCount; /* Number of times the |warmUpCount| was
* forcibly discarded. The counter is reset when
* a script is successfully jit-compiled. */
uint16_t version; /* JS version under which script was compiled */
uint16_t funLength_; /* ES6 function length */
uint16_t nTypeSets_; /* number of type sets used in this script for
dynamic type monitoring */
// Bit fields.
// The kinds of the optional arrays.
enum ArrayKind {
// The bits in this field indicate the presence/non-presence of several
// optional arrays in |data|. See the comments above Create() for details.
uint8_t hasArrayBits:ARRAY_KIND_BITS;
// The GeneratorKind of the script.
uint8_t generatorKindBits_:2;
// 1-bit fields.
// No need for result value of last expression statement.
bool noScriptRval_:1;
// Can call getCallerFunction().
bool savedCallerFun_:1;
// Code is in strict mode.
bool strict_:1;
// Code has "use strict"; explicitly.
bool explicitUseStrict_:1;
// True if the script has a non-syntactic scope on its dynamic scope chain.
// That is, there are objects about which we know nothing between the
// outermost syntactic scope and the global.
bool hasNonSyntacticScope_:1;
// see Parser::selfHostingMode.
bool selfHosted_:1;
// See FunctionContextFlags.
bool bindingsAccessedDynamically_:1;
bool funHasExtensibleScope_:1;
bool funNeedsDeclEnvObject_:1;
// True if any formalIsAliased(i).
bool funHasAnyAliasedFormal_:1;
// Have warned about uses of undefined properties in this script.
bool warnedAboutUndefinedProp_:1;
// Script has singleton objects.
bool hasSingletons_:1;
// Script is a lambda to treat as running once or a global or eval script
// that will only run once. Which one it is can be disambiguated by
// checking whether function_ is null.
bool treatAsRunOnce_:1;
// If treatAsRunOnce, whether script has executed.
bool hasRunOnce_:1;
// Script has been reused for a clone.
bool hasBeenCloned_:1;
// Script came from eval(), and is still active.
bool isActiveEval_:1;
// Script came from eval(), and is in eval cache.
bool isCachedEval_:1;
// 'this', 'arguments' and f.apply() are used. This is likely to be a wrapper.
bool isLikelyConstructorWrapper_:1;
// IonMonkey compilation hints.
bool failedBoundsCheck_:1; /* script has had hoisted bounds checks fail */
bool failedShapeGuard_:1; /* script has had hoisted shape guard fail */
bool hadFrequentBailouts_:1;
bool uninlineable_:1; /* explicitly marked as uninlineable */
// Idempotent cache has triggered invalidation.
bool invalidatedIdempotentCache_:1;
// Lexical check did fail and bail out.
bool failedLexicalCheck_:1;
// If the generator was created implicitly via a generator expression,
// isGeneratorExp will be true.
bool isGeneratorExp_:1;
// Script has an entry in JSCompartment::scriptCountsMap.
bool hasScriptCounts_:1;
// Script has an entry in JSCompartment::debugScriptMap.
bool hasDebugScript_:1;
// Freeze constraints for stack type sets have been generated.
bool hasFreezeConstraints_:1;
/* See comments below. */
bool argsHasVarBinding_:1;
bool needsArgsAnalysis_:1;
bool needsArgsObj_:1;
bool functionHasThisBinding_:1;
// Whether the arguments object for this script, if it needs one, should be
// mapped (alias formal parameters).
bool hasMappedArgsObj_:1;
// Generation for this script's TypeScript. If out of sync with the
// TypeZone's generation, the TypeScript needs to be swept.
// This should be a uint32 but is instead a bool so that MSVC packs it
// correctly.
bool typesGeneration_:1;
// Do not relazify this script. This is used by the relazify() testing
// function for scripts that are on the stack and also by the AutoDelazify
// RAII class. Usually we don't relazify functions in compartments with
// scripts on the stack, but the relazify() testing function overrides that,
// and sometimes we're working with a cross-compartment function and need to
// keep it from relazifying.
bool doNotRelazify_:1;
// Script contains inner functions. Used to check if we can relazify the
// script.
bool hasInnerFunctions_:1;
bool needsHomeObject_:1;
bool isDerivedClassConstructor_:1;
// Add padding so JSScript is gc::Cell aligned. Make padding protected
// instead of private to suppress -Wunused-private-field compiler warnings.
#if JS_BITS_PER_WORD == 32
// No padding currently required.
// End of fields. Start methods.
static JSScript* Create(js::ExclusiveContext* cx,
js::HandleObject enclosingScope, bool savedCallerFun,
const JS::ReadOnlyCompileOptions& options,
js::HandleObject sourceObject, uint32_t sourceStart,
uint32_t sourceEnd);
void initCompartment(js::ExclusiveContext* cx);
// Three ways ways to initialize a JSScript. Callers of partiallyInit()
// and fullyInitTrivial() are responsible for notifying the debugger after
// successfully creating any kind (function or other) of new JSScript.
// However, callers of fullyInitFromEmitter() do not need to do this.
static bool partiallyInit(js::ExclusiveContext* cx, JS::Handle<JSScript*> script,
uint32_t nconsts, uint32_t nobjects, uint32_t nregexps,
uint32_t ntrynotes, uint32_t nblockscopes, uint32_t nyieldoffsets,
uint32_t nTypeSets);
static bool fullyInitFromEmitter(js::ExclusiveContext* cx, JS::Handle<JSScript*> script,
js::frontend::BytecodeEmitter* bce);
static void linkToFunctionFromEmitter(js::ExclusiveContext* cx, JS::Handle<JSScript*> script,
js::frontend::FunctionBox* funbox);
static void linkToModuleFromEmitter(js::ExclusiveContext* cx, JS::Handle<JSScript*> script,
js::frontend::ModuleBox* funbox);
// Initialize a no-op script.
static bool fullyInitTrivial(js::ExclusiveContext* cx, JS::Handle<JSScript*> script);
inline JSPrincipals* principals();
JSCompartment* compartment() const { return compartment_; }
JSCompartment* maybeCompartment() const { return compartment(); }
void setVersion(JSVersion v) { version = v; }
// Script bytecode is immutable after creation.
jsbytecode* code() const {
return code_;
size_t length() const {
return length_;
void setCode(jsbytecode* code) { code_ = code; }
void setLength(size_t length) { length_ = length; }
jsbytecode* codeEnd() const { return code() + length(); }
jsbytecode* lastPC() const {
jsbytecode* pc = codeEnd() - js::JSOP_RETRVAL_LENGTH;
return pc;
bool containsPC(const jsbytecode* pc) const {
return pc >= code() && pc < codeEnd();
size_t pcToOffset(const jsbytecode* pc) const {
return size_t(pc - code());
jsbytecode* offsetToPC(size_t offset) const {
MOZ_ASSERT(offset < length());
return code() + offset;
size_t mainOffset() const {
return mainOffset_;
size_t lineno() const {
return lineno_;
size_t column() const {
return column_;
void setColumn(size_t column) { column_ = column; }
// The fixed part of a stack frame is comprised of vars (in function code)
// and block-scoped locals (in all kinds of code).
size_t nfixed() const {
return function_ ? bindings.numFixedLocals() : bindings.numBlockScoped();
// Number of fixed slots reserved for vars. Only nonzero for function
// code.
size_t nfixedvars() const {
return function_ ? bindings.numUnaliasedVars() : 0;
// Number of fixed slots reserved for body-level lexicals and vars. This
// value minus nfixedvars() is the number of body-level lexicals. Only
// nonzero for function code.
size_t nbodyfixed() const {
return function_ ? bindings.numUnaliasedBodyLevelLocals() : 0;
// Calculate the number of fixed slots that are live at a particular bytecode.
size_t calculateLiveFixed(jsbytecode* pc);
// Aliases for clarity when dealing with lexical slots.
size_t fixedLexicalBegin() const {
return nfixedvars();
size_t fixedLexicalEnd() const {
return nfixed();
size_t nslots() const {
return nslots_;
size_t nTypeSets() const {
return nTypeSets_;
size_t funLength() const {
return funLength_;
size_t sourceStart() const {
return sourceStart_;
size_t sourceEnd() const {
return sourceEnd_;
bool noScriptRval() const {
return noScriptRval_;
bool savedCallerFun() const { return savedCallerFun_; }
bool strict() const {
return strict_;
bool explicitUseStrict() const { return explicitUseStrict_; }
bool hasNonSyntacticScope() const {
return hasNonSyntacticScope_;
bool selfHosted() const { return selfHosted_; }
bool bindingsAccessedDynamically() const { return bindingsAccessedDynamically_; }
bool funHasExtensibleScope() const {
return funHasExtensibleScope_;
bool funNeedsDeclEnvObject() const {
return funNeedsDeclEnvObject_;
bool funHasAnyAliasedFormal() const {
return funHasAnyAliasedFormal_;
bool hasSingletons() const { return hasSingletons_; }
bool treatAsRunOnce() const {
return treatAsRunOnce_;
bool hasRunOnce() const { return hasRunOnce_; }
bool hasBeenCloned() const { return hasBeenCloned_; }
void setTreatAsRunOnce() { treatAsRunOnce_ = true; }
void setHasRunOnce() { hasRunOnce_ = true; }
void setHasBeenCloned() { hasBeenCloned_ = true; }
bool isActiveEval() const { return isActiveEval_; }
bool isCachedEval() const { return isCachedEval_; }
void cacheForEval() {
MOZ_ASSERT(isActiveEval() && !isCachedEval());
isActiveEval_ = false;
isCachedEval_ = true;
// IsEvalCacheCandidate will make sure that there's nothing in this
// script that would prevent reexecution even if isRunOnce is
// true. So just pretend like we never ran this script.
hasRunOnce_ = false;
void uncacheForEval() {
MOZ_ASSERT(isCachedEval() && !isActiveEval());
isCachedEval_ = false;
isActiveEval_ = true;
void setActiveEval() { isActiveEval_ = true; }
bool isLikelyConstructorWrapper() const {
return isLikelyConstructorWrapper_;
void setLikelyConstructorWrapper() { isLikelyConstructorWrapper_ = true; }
bool isGeneratorExp() const { return isGeneratorExp_; }
bool failedBoundsCheck() const {
return failedBoundsCheck_;
bool failedShapeGuard() const {
return failedShapeGuard_;
bool hadFrequentBailouts() const {
return hadFrequentBailouts_;
bool uninlineable() const {
return uninlineable_;
bool invalidatedIdempotentCache() const {
return invalidatedIdempotentCache_;
bool failedLexicalCheck() const {
return failedLexicalCheck_;
void setFailedBoundsCheck() { failedBoundsCheck_ = true; }
void setFailedShapeGuard() { failedShapeGuard_ = true; }
void setHadFrequentBailouts() { hadFrequentBailouts_ = true; }
void setUninlineable() { uninlineable_ = true; }
void setInvalidatedIdempotentCache() { invalidatedIdempotentCache_ = true; }
void setFailedLexicalCheck() { failedLexicalCheck_ = true; }
bool hasScriptCounts() const { return hasScriptCounts_; }
bool hasFreezeConstraints() const { return hasFreezeConstraints_; }
void setHasFreezeConstraints() { hasFreezeConstraints_ = true; }
bool warnedAboutUndefinedProp() const { return warnedAboutUndefinedProp_; }
void setWarnedAboutUndefinedProp() { warnedAboutUndefinedProp_ = true; }
/* See ContextFlags::funArgumentsHasLocalBinding comment. */
bool argumentsHasVarBinding() const {
return argsHasVarBinding_;
jsbytecode* argumentsBytecode() const { MOZ_ASSERT(code()[0] == JSOP_ARGUMENTS); return code(); }
void setArgumentsHasVarBinding();
bool argumentsAliasesFormals() const {
return argumentsHasVarBinding() && hasMappedArgsObj();
js::GeneratorKind generatorKind() const {
return js::GeneratorKindFromBits(generatorKindBits_);
bool isGenerator() const { return generatorKind() != js::NotGenerator; }
bool isLegacyGenerator() const { return generatorKind() == js::LegacyGenerator; }
bool isStarGenerator() const { return generatorKind() == js::StarGenerator; }
void setGeneratorKind(js::GeneratorKind kind) {
// A script only gets its generator kind set as part of initialization,
// so it can only transition from not being a generator.
generatorKindBits_ = GeneratorKindAsBits(kind);
void setNeedsHomeObject() {
needsHomeObject_ = true;
bool needsHomeObject() const {
return needsHomeObject_;
bool isDerivedClassConstructor() const {
return isDerivedClassConstructor_;
* As an optimization, even when argsHasLocalBinding, the function prologue
* may not need to create an arguments object. This is determined by
* needsArgsObj which is set by AnalyzeArgumentsUsage. When !needsArgsObj,
* the prologue may simply write MagicValue(JS_OPTIMIZED_ARGUMENTS) to
* 'arguments's slot and any uses of 'arguments' will be guaranteed to
* handle this magic value. To avoid spurious arguments object creation, we
* maintain the invariant that needsArgsObj is only called after the script
* has been analyzed.
bool analyzedArgsUsage() const { return !needsArgsAnalysis_; }
inline bool ensureHasAnalyzedArgsUsage(JSContext* cx);
bool needsArgsObj() const {
return needsArgsObj_;
void setNeedsArgsObj(bool needsArgsObj);
static bool argumentsOptimizationFailed(JSContext* cx, js::HandleScript script);
bool hasMappedArgsObj() const {
return hasMappedArgsObj_;
bool functionHasThisBinding() const {
return functionHasThisBinding_;
* Arguments access (via JSOP_*ARG* opcodes) must access the canonical
* location for the argument. If an arguments object exists AND it's mapped
* ('arguments' aliases formals), then all access must go through the
* arguments object. Otherwise, the local slot is the canonical location for
* the arguments. Note: if a formal is aliased through the scope chain, then
* script->formalIsAliased and JSOP_*ARG* opcodes won't be emitted at all.
bool argsObjAliasesFormals() const {
return needsArgsObj() && hasMappedArgsObj();
uint32_t typesGeneration() const {
return (uint32_t) typesGeneration_;
void setTypesGeneration(uint32_t generation) {
MOZ_ASSERT(generation <= 1);
typesGeneration_ = (bool) generation;
void setDoNotRelazify(bool b) {
doNotRelazify_ = b;
void setHasInnerFunctions(bool b) {
hasInnerFunctions_ = b;
bool hasInnerFunctions() const {
return hasInnerFunctions_;
bool hasAnyIonScript() const {
return hasIonScript();
bool hasIonScript() const {
bool res = ion && ion != ION_DISABLED_SCRIPT && ion != ION_COMPILING_SCRIPT &&
MOZ_ASSERT_IF(res, baseline);
return res;
bool canIonCompile() const {
return ion != ION_DISABLED_SCRIPT;
bool isIonCompilingOffThread() const {
js::jit::IonScript* ionScript() const {
return ion;
js::jit::IonScript* maybeIonScript() const {
return ion;
js::jit::IonScript* const* addressOfIonScript() const {
return &ion;
void setIonScript(JSContext* maybecx, js::jit::IonScript* ionScript);
bool hasBaselineScript() const {
bool res = baseline && baseline != BASELINE_DISABLED_SCRIPT;
MOZ_ASSERT_IF(!res, !ion || ion == ION_DISABLED_SCRIPT);
return res;
bool canBaselineCompile() const {
return baseline != BASELINE_DISABLED_SCRIPT;
js::jit::BaselineScript* baselineScript() const {
return baseline;
inline void setBaselineScript(JSContext* maybecx, js::jit::BaselineScript* baselineScript);
void updateBaselineOrIonRaw(JSContext* maybecx);
static size_t offsetOfBaselineScript() {
return offsetof(JSScript, baseline);
static size_t offsetOfIonScript() {
return offsetof(JSScript, ion);
static size_t offsetOfBaselineOrIonRaw() {
return offsetof(JSScript, baselineOrIonRaw);
uint8_t* baselineOrIonRawPointer() const {
return baselineOrIonRaw;
static size_t offsetOfBaselineOrIonSkipArgCheck() {
return offsetof(JSScript, baselineOrIonSkipArgCheck);
bool isRelazifiable() const {
return (selfHosted() || lazyScript) && !hasInnerFunctions_ && !types_ &&
!isGenerator() && !hasBaselineScript() && !hasAnyIonScript() &&
!hasScriptCounts() && !doNotRelazify_;
void setLazyScript(js::LazyScript* lazy) {
lazyScript = lazy;
js::LazyScript* maybeLazyScript() {
return lazyScript;
* Original compiled function for the script, if it has a function.
* nullptr for global and eval scripts.
* The delazifying variant ensures that the function isn't lazy. The
* non-delazifying variant must only be used after earlier code has
* called ensureNonLazyCanonicalFunction and while the function can't
* have been relazified.
inline JSFunction* functionDelazifying() const;
JSFunction* functionNonDelazifying() const {
return function_;
inline void setFunction(JSFunction* fun);
* De-lazifies the canonical function. Must be called before entering code
* that expects the function to be non-lazy.
inline void ensureNonLazyCanonicalFunction(JSContext* cx);
js::ModuleObject* module() const {
return module_;
inline void setModule(js::ModuleObject* module);
// Returns true if the script may read formal arguments on the stack
// directly, via lazy arguments or a rest parameter.
bool mayReadFrameArgsDirectly();
JSFlatString* sourceData(JSContext* cx);
static bool loadSource(JSContext* cx, js::ScriptSource* ss, bool* worked);
void setSourceObject(JSObject* object);
JSObject* sourceObject() const {
return sourceObject_;
js::ScriptSourceObject& scriptSourceUnwrap() const;
js::ScriptSource* scriptSource() const;
js::ScriptSource* maybeForwardedScriptSource() const;
bool mutedErrors() const { return scriptSource()->mutedErrors(); }
const char* filename() const { return scriptSource()->filename(); }
const char* maybeForwardedFilename() const { return maybeForwardedScriptSource()->filename(); }
/* Return whether this script was compiled for 'eval' */
bool isForEval() { return isCachedEval() || isActiveEval(); }
* Return whether this script is a top-level script.
* If we evaluate some code which contains a syntax error, then we might
* produce a JSScript which has no associated bytecode. Testing with
* |code()| filters out this kind of scripts.
* If this script has a function associated to it, then it is not the
* top-level of a file.
bool isTopLevel() { return code() && !functionNonDelazifying(); }
/* Ensure the script has a TypeScript. */
inline bool ensureHasTypes(JSContext* cx);
inline js::TypeScript* types();
void maybeSweepTypes(js::AutoClearTypeInferenceStateOnOOM* oom);
inline js::GlobalObject& global() const;
js::GlobalObject& uninlinedGlobal() const;
/* See StaticScopeIter comment. */
JSObject* enclosingStaticScope() const {
return enclosingStaticScope_;
// Switch the script over from the off-thread compartment's static
// global lexical scope to the main thread compartment's.
void fixEnclosingStaticGlobalLexicalScope();
bool makeTypes(JSContext* cx);
uint32_t getWarmUpCount() const { return warmUpCount; }
uint32_t incWarmUpCounter(uint32_t amount = 1) { return warmUpCount += amount; }
uint32_t* addressOfWarmUpCounter() { return &warmUpCount; }
static size_t offsetOfWarmUpCounter() { return offsetof(JSScript, warmUpCount); }
void resetWarmUpCounter() { incWarmUpResetCounter(); warmUpCount = 0; }
uint16_t getWarmUpResetCount() const { return warmUpResetCount; }
uint16_t incWarmUpResetCounter(uint16_t amount = 1) { return warmUpResetCount += amount; }
void resetWarmUpResetCounter() { warmUpResetCount = 0; }
bool initScriptCounts(JSContext* cx);
js::ScriptCounts& getScriptCounts();
js::PCCounts* maybeGetPCCounts(jsbytecode* pc);
const js::PCCounts* maybeGetThrowCounts(jsbytecode* pc);
js::PCCounts* getThrowCounts(jsbytecode* pc);
uint64_t getHitCount(jsbytecode* pc);
void incHitCount(jsbytecode* pc); // Used when we bailout out of Ion.
void addIonCounts(js::jit::IonScriptCounts* ionCounts);
js::jit::IonScriptCounts* getIonCounts();
void releaseScriptCounts(js::ScriptCounts* counts);
void destroyScriptCounts(js::FreeOp* fop);
// The entry should be removed after using this function.
void takeOverScriptCountsMapEntry(js::ScriptCounts* entryValue);
jsbytecode* main() {
return code() + mainOffset();
* computedSizeOfData() is the in-use size of all the data sections.
* sizeOfData() is the size of the block allocated to hold all the data
* sections (which can be larger than the in-use size).
size_t computedSizeOfData() const;
size_t sizeOfData(mozilla::MallocSizeOf mallocSizeOf) const;
size_t sizeOfTypeScript(mozilla::MallocSizeOf mallocSizeOf) const;
uint32_t numNotes(); /* Number of srcnote slots in the srcnotes section */
/* Script notes are allocated right after the code. */
jssrcnote* notes() { return (jssrcnote*)(code() + length()); }
bool hasArray(ArrayKind kind) {
return hasArrayBits & (1 << kind);
void setHasArray(ArrayKind kind) { hasArrayBits |= (1 << kind); }
void cloneHasArray(JSScript* script) { hasArrayBits = script->hasArrayBits; }
bool hasConsts() { return hasArray(CONSTS); }
bool hasObjects() { return hasArray(OBJECTS); }
bool hasRegexps() { return hasArray(REGEXPS); }
bool hasTrynotes() { return hasArray(TRYNOTES); }
bool hasBlockScopes() { return hasArray(BLOCK_SCOPES); }
bool hasYieldOffsets() { return isGenerator(); }
#define OFF(fooOff, hasFoo, t) (fooOff() + (hasFoo() ? sizeof(t) : 0))
size_t constsOffset() { return 0; }
size_t objectsOffset() { return OFF(constsOffset, hasConsts, js::ConstArray); }
size_t regexpsOffset() { return OFF(objectsOffset, hasObjects, js::ObjectArray); }
size_t trynotesOffset() { return OFF(regexpsOffset, hasRegexps, js::ObjectArray); }
size_t blockScopesOffset() { return OFF(trynotesOffset, hasTrynotes, js::TryNoteArray); }
size_t yieldOffsetsOffset() { return OFF(blockScopesOffset, hasBlockScopes, js::BlockScopeArray); }
size_t dataSize() const { return dataSize_; }
js::ConstArray* consts() {
return reinterpret_cast<js::ConstArray*>(data + constsOffset());
js::ObjectArray* objects() {
return reinterpret_cast<js::ObjectArray*>(data + objectsOffset());
js::ObjectArray* regexps() {
return reinterpret_cast<js::ObjectArray*>(data + regexpsOffset());
js::TryNoteArray* trynotes() {
return reinterpret_cast<js::TryNoteArray*>(data + trynotesOffset());
js::BlockScopeArray* blockScopes() {
return reinterpret_cast<js::BlockScopeArray*>(data + blockScopesOffset());
js::YieldOffsetArray& yieldOffsets() {
return *reinterpret_cast<js::YieldOffsetArray*>(data + yieldOffsetsOffset());
bool hasLoops();
size_t natoms() const { return natoms_; }
js::HeapPtrAtom& getAtom(size_t index) const {
MOZ_ASSERT(index < natoms());
return atoms[index];
js::HeapPtrAtom& getAtom(jsbytecode* pc) const {
MOZ_ASSERT(containsPC(pc) && containsPC(pc + sizeof(uint32_t)));
return getAtom(GET_UINT32_INDEX(pc));
js::PropertyName* getName(size_t index) {
return getAtom(index)->asPropertyName();
js::PropertyName* getName(jsbytecode* pc) const {
MOZ_ASSERT(containsPC(pc) && containsPC(pc + sizeof(uint32_t)));
return getAtom(GET_UINT32_INDEX(pc))->asPropertyName();
JSObject* getObject(size_t index) {
js::ObjectArray* arr = objects();
MOZ_ASSERT(index < arr->length);
return arr->vector[index];
size_t innerObjectsStart() {
// The first object contains the caller if savedCallerFun is used.
return savedCallerFun() ? 1 : 0;
JSObject* getObject(jsbytecode* pc) {
MOZ_ASSERT(containsPC(pc) && containsPC(pc + sizeof(uint32_t)));
return getObject(GET_UINT32_INDEX(pc));
JSVersion getVersion() const {
return JSVersion(version);
inline JSFunction* getFunction(size_t index);
inline JSFunction* getCallerFunction();
inline JSFunction* functionOrCallerFunction();
inline js::RegExpObject* getRegExp(size_t index);
inline js::RegExpObject* getRegExp(jsbytecode* pc);
const js::Value& getConst(size_t index) {
js::ConstArray* arr = consts();
MOZ_ASSERT(index < arr->length);
return arr->vector[index];
// The following 4 functions find the static scope just before the
// execution of the instruction pointed to by pc.
js::NestedScopeObject* getStaticBlockScope(jsbytecode* pc);
// Returns the innermost static scope at pc if it falls within the extent
// of the script. Returns nullptr otherwise.
JSObject* innermostStaticScopeInScript(jsbytecode* pc);
// As innermostStaticScopeInScript, but returns the enclosing static scope
// if the innermost static scope falls without the extent of the script.
JSObject* innermostStaticScope(jsbytecode* pc);
JSObject* innermostStaticScope() { return innermostStaticScope(main()); }
* The isEmpty method tells whether this script has code that computes any
* result (not return value, result AKA normal completion value) other than
* JSVAL_VOID, or any other effects.
bool isEmpty() const {
if (length() > 3)
return false;
jsbytecode* pc = code();
if (noScriptRval() && JSOp(*pc) == JSOP_FALSE)
return JSOp(*pc) == JSOP_RETRVAL;
bool bindingIsAliased(const js::BindingIter& bi);
bool formalIsAliased(unsigned argSlot);
bool formalLivesInArgumentsObject(unsigned argSlot);
bool localIsAliased(unsigned localSlot);
/* Change this->stepMode to |newValue|. */
void setNewStepMode(js::FreeOp* fop, uint32_t newValue);
bool ensureHasDebugScript(JSContext* cx);
js::DebugScript* debugScript();
js::DebugScript* releaseDebugScript();
void destroyDebugScript(js::FreeOp* fop);
bool hasBreakpointsAt(jsbytecode* pc);
bool hasAnyBreakpointsOrStepMode() { return hasDebugScript_; }
// See comment above 'debugMode' in jscompartment.h for explanation of
// invariants of debuggee compartments, scripts, and frames.
inline bool isDebuggee() const;
js::BreakpointSite* getBreakpointSite(jsbytecode* pc)
return hasDebugScript_ ? debugScript()->breakpoints[pcToOffset(pc)] : nullptr;
js::BreakpointSite* getOrCreateBreakpointSite(JSContext* cx, jsbytecode* pc);
void destroyBreakpointSite(js::FreeOp* fop, jsbytecode* pc);
void clearBreakpointsIn(js::FreeOp* fop, js::Debugger* dbg, JSObject* handler);
* Increment or decrement the single-step count. If the count is non-zero
* then the script is in single-step mode.
* Only incrementing is fallible, as it could allocate a DebugScript.
bool incrementStepModeCount(JSContext* cx);
void decrementStepModeCount(js::FreeOp* fop);
bool stepModeEnabled() { return hasDebugScript_ && !!debugScript()->stepMode; }
#ifdef DEBUG
uint32_t stepModeCount() { return hasDebugScript_ ? debugScript()->stepMode : 0; }
void finalize(js::FreeOp* fop);
void fixupAfterMovingGC() {}
static inline js::ThingRootKind rootKind() { return js::THING_ROOT_SCRIPT; }
void traceChildren(JSTracer* trc);
// A helper class to prevent relazification of the given function's script
// while it's holding on to it. This class automatically roots the script.
class AutoDelazify;
friend class AutoDelazify;
class AutoDelazify
JS::RootedScript script_;
JSContext* cx_;
bool oldDoNotRelazify_;
explicit AutoDelazify(JSContext* cx, JS::HandleFunction fun = nullptr)
: script_(cx)
, cx_(cx)
void operator=(JS::HandleFunction fun)
operator JS::HandleScript() const { return script_; }
explicit operator bool() const { return script_; }
void holdScript(JS::HandleFunction fun);
void dropScript();
/* If this fails, add/remove padding within JSScript. */
static_assert(sizeof(JSScript) % js::gc::CellSize == 0,
"Size of JSScript must be an integral multiple of js::gc::CellSize");
namespace js {
* Iterator over a script's bindings (formals and variables).
* The order of iteration is:
* - first, formal arguments, from index 0 to numArgs
* - next, variables, from index 0 to numLocals
class BindingIter
Handle<Bindings> bindings_;
uint32_t i_;
uint32_t unaliasedLocal_;
friend class ::JSScript;
friend class Bindings;
explicit BindingIter(Handle<Bindings> bindings)
: bindings_(bindings), i_(0), unaliasedLocal_(0)
explicit BindingIter(const HandleScript& script)
: bindings_(Handle<Bindings>::fromMarkedLocation(&script->bindings)),
i_(0), unaliasedLocal_(0)
bool done() const { return i_ == bindings_.count(); }
explicit operator bool() const { return !done(); }
BindingIter& operator++() { (*this)++; return *this; }
void operator++(int) {
const Binding& binding = **this;
if (binding.kind() != Binding::ARGUMENT && !binding.aliased())
// Stack slots are assigned to arguments (aliased and unaliased) and
// unaliased locals. frameIndex() returns the slot index. It's invalid to
// call this method when the iterator is stopped on an aliased local, as it
// has no stack slot.
uint32_t frameIndex() const {
if (i_ < bindings_.numArgs())
return i_;
return unaliasedLocal_;
// If the current binding is an argument, argIndex() returns its index.
// It returns the same value as frameIndex(), as slots are allocated for
// both unaliased and aliased arguments.
uint32_t argIndex() const {
MOZ_ASSERT(i_ < bindings_.numArgs());
return i_;
uint32_t argOrLocalIndex() const {
return i_ < bindings_.numArgs() ? i_ : i_ - bindings_.numArgs();
uint32_t localIndex() const {
MOZ_ASSERT(i_ >= bindings_.numArgs());
return i_ - bindings_.numArgs();
bool isBodyLevelLexical() const {
const Binding& binding = **this;
return binding.kind() != Binding::ARGUMENT;
const Binding& operator*() const { MOZ_ASSERT(!done()); return bindings_.bindingArray()[i_]; }
const Binding* operator->() const { MOZ_ASSERT(!done()); return &bindings_.bindingArray()[i_]; }
* Iterator over the aliased formal bindings in ascending index order. This can
* be veiwed as a filtering of BindingIter with predicate
* bi->aliased() && bi->kind() == Binding::ARGUMENT
class AliasedFormalIter
const Binding* begin_;
const Binding* p_;
const Binding* end_;
unsigned slot_;
void settle() {
while (p_ != end_ && !p_->aliased())
explicit inline AliasedFormalIter(JSScript* script);
bool done() const { return p_ == end_; }
explicit operator bool() const { return !done(); }
void operator++(int) { MOZ_ASSERT(!done()); p_++; slot_++; settle(); }
const Binding& operator*() const { MOZ_ASSERT(!done()); return *p_; }
const Binding* operator->() const { MOZ_ASSERT(!done()); return p_; }
unsigned frameIndex() const { MOZ_ASSERT(!done()); return p_ - begin_; }
unsigned scopeSlot() const { MOZ_ASSERT(!done()); return slot_; }
// Information about a script which may be (or has been) lazily compiled to
// bytecode from its source.
class LazyScript : public gc::TenuredCell
class FreeVariable
// Variable name is stored as a tagged JSAtom pointer.
uintptr_t bits_;
static const uintptr_t HOISTED_USE_BIT = 0x1;
static const uintptr_t MASK = ~HOISTED_USE_BIT;
explicit FreeVariable()
: bits_(0)
{ }
explicit FreeVariable(JSAtom* name)
: bits_(uintptr_t(name))
// We rely on not requiring any write barriers so we can tag the
// pointer. This code needs to change if we start allocating
// JSAtoms inside the nursery.
JSAtom* atom() const { return (JSAtom*)(bits_ & MASK); }
void setIsHoistedUse() { bits_ |= HOISTED_USE_BIT; }
bool isHoistedUse() const { return bool(bits_ & HOISTED_USE_BIT); }
// If non-nullptr, the script has been compiled and this is a forwarding
// pointer to the result. This is a weak pointer: after relazification, we
// can collect the script if there are no other pointers to it.
WeakRef<JSScript*> script_;
// Original function with which the lazy script is associated.
HeapPtrFunction function_;
// Function or block chain in which the script is nested, or nullptr.
HeapPtrObject enclosingScope_;
// ScriptSourceObject, or nullptr if the script in which this is nested
// has not been compiled yet. This is never a CCW; we don't clone
// LazyScripts into other compartments.
HeapPtrObject sourceObject_;
// Heap allocated table with any free variables or inner functions.
void* table_;
// Add padding so LazyScript is gc::Cell aligned. Make padding protected
// instead of private to suppress -Wunused-private-field compiler warnings.
#if JS_BITS_PER_WORD == 32
uint32_t padding;
struct PackedView {
// Assorted bits that should really be in ScriptSourceObject.
uint32_t version : 8;
uint32_t numFreeVariables : 24;
uint32_t numInnerFunctions : 20;
uint32_t generatorKindBits : 2;
// N.B. These are booleans but need to be uint32_t to pack correctly on MSVC.
// If you add another boolean here, make sure to initialze it in
// LazyScript::CreateRaw().
uint32_t strict : 1;
uint32_t bindingsAccessedDynamically : 1;
uint32_t hasDebuggerStatement : 1;
uint32_t hasDirectEval : 1;
uint32_t isLikelyConstructorWrapper : 1;
uint32_t hasBeenCloned : 1;
uint32_t treatAsRunOnce : 1;
uint32_t isDerivedClassConstructor : 1;
uint32_t needsHomeObject : 1;
union {
PackedView p_;
uint64_t packedFields_;
// Source location for the script.
uint32_t begin_;
uint32_t end_;
uint32_t lineno_;
uint32_t column_;
LazyScript(JSFunction* fun, void* table, uint64_t packedFields,
uint32_t begin, uint32_t end, uint32_t lineno, uint32_t column);
// Create a LazyScript without initializing the freeVariables and the
// innerFunctions. To be GC-safe, the caller must initialize both vectors
// with valid atoms and functions.
static LazyScript* CreateRaw(ExclusiveContext* cx, HandleFunction fun,
uint64_t packedData, uint32_t begin, uint32_t end,
uint32_t lineno, uint32_t column);
// Create a LazyScript without initializing the freeVariables and the
// innerFunctions. To be GC-safe, the caller must initialize both vectors
// with valid atoms and functions.
static LazyScript* CreateRaw(ExclusiveContext* cx, HandleFunction fun,
uint32_t numFreeVariables, uint32_t numInnerFunctions,
JSVersion version, uint32_t begin, uint32_t end,
uint32_t lineno, uint32_t column);
// Create a LazyScript and initialize the freeVariables and the
// innerFunctions with dummy values to be replaced in a later initialization
// phase.
// The "script" argument to this function can be null. If it's non-null,
// then this LazyScript should be associated with the given JSScript.
// The sourceObjectScript argument must be non-null and is the script that
// should be used to get the sourceObject_ of this lazyScript.
static LazyScript* Create(ExclusiveContext* cx, HandleFunction fun,
HandleScript script, HandleObject enclosingScope,
HandleScript sourceObjectScript,
uint64_t packedData, uint32_t begin, uint32_t end,
uint32_t lineno, uint32_t column);
void initRuntimeFields(uint64_t packedFields);
inline JSFunction* functionDelazifying(JSContext* cx) const;
JSFunction* functionNonDelazifying() const {
return function_;
void initScript(JSScript* script);
void resetScript();
JSScript* maybeScript() {
return script_;
const JSScript* maybeScriptUnbarriered() const {
return script_.unbarrieredGet();
bool hasScript() const {
return bool(script_);
JSObject* enclosingScope() const {
return enclosingScope_;
// Switch the script over from the off-thread compartment's static
// global lexical scope to the main thread compartment's.
void fixEnclosingStaticGlobalLexicalScope();
ScriptSourceObject* sourceObject() const;
ScriptSource* scriptSource() const {
return sourceObject()->source();
ScriptSource* maybeForwardedScriptSource() const;
bool mutedErrors() const {
return scriptSource()->mutedErrors();
JSVersion version() const {
return (p_.version == JS_BIT(8) - 1) ? JSVERSION_UNKNOWN : JSVersion(p_.version);
void setParent(JSObject* enclosingScope, ScriptSourceObject* sourceObject);
uint32_t numFreeVariables() const {
return p_.numFreeVariables;
FreeVariable* freeVariables() {
return (FreeVariable*)table_;
uint32_t numInnerFunctions() const {
return p_.numInnerFunctions;
HeapPtrFunction* innerFunctions() {
return (HeapPtrFunction*)&freeVariables()[numFreeVariables()];
GeneratorKind generatorKind() const { return GeneratorKindFromBits(p_.generatorKindBits); }
bool isGenerator() const { return generatorKind() != NotGenerator; }
bool isLegacyGenerator() const { return generatorKind() == LegacyGenerator; }
bool isStarGenerator() const { return generatorKind() == StarGenerator; }
void setGeneratorKind(GeneratorKind kind) {
// A script only gets its generator kind set as part of initialization,
// so it can only transition from NotGenerator.
// Legacy generators cannot currently be lazy.
MOZ_ASSERT(kind != LegacyGenerator);
p_.generatorKindBits = GeneratorKindAsBits(kind);
bool strict() const {
return p_.strict;
void setStrict() {
p_.strict = true;
bool bindingsAccessedDynamically() const {
return p_.bindingsAccessedDynamically;
void setBindingsAccessedDynamically() {
p_.bindingsAccessedDynamically = true;
bool hasDebuggerStatement() const {
return p_.hasDebuggerStatement;
void setHasDebuggerStatement() {
p_.hasDebuggerStatement = true;
bool hasDirectEval() const {
return p_.hasDirectEval;
void setHasDirectEval() {
p_.hasDirectEval = true;
bool isLikelyConstructorWrapper() const {
return p_.isLikelyConstructorWrapper;
void setLikelyConstructorWrapper() {
p_.isLikelyConstructorWrapper = true;
bool hasBeenCloned() const {
return p_.hasBeenCloned;
void setHasBeenCloned() {
p_.hasBeenCloned = true;
bool treatAsRunOnce() const {
return p_.treatAsRunOnce;
void setTreatAsRunOnce() {
p_.treatAsRunOnce = true;
bool isDerivedClassConstructor() const {
return p_.isDerivedClassConstructor;
void setIsDerivedClassConstructor() {
p_.isDerivedClassConstructor = true;
bool needsHomeObject() const {
return p_.needsHomeObject;
void setNeedsHomeObject() {
p_.needsHomeObject = true;
const char* filename() const {
return scriptSource()->filename();
uint32_t begin() const {
return begin_;
uint32_t end() const {
return end_;
uint32_t lineno() const {
return lineno_;
uint32_t column() const {
return column_;
bool hasUncompiledEnclosingScript() const;
friend class GCMarker;
void traceChildren(JSTracer* trc);
void finalize(js::FreeOp* fop);
void fixupAfterMovingGC() {}
static inline js::ThingRootKind rootKind() { return js::THING_ROOT_LAZY_SCRIPT; }
size_t sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf)
return mallocSizeOf(table_);
uint64_t packedFields() const {
return packedFields_;
/* If this fails, add/remove padding within LazyScript. */
JS_STATIC_ASSERT(sizeof(LazyScript) % js::gc::CellSize == 0);
struct SharedScriptData
uint32_t length;
uint32_t natoms;
mozilla::Atomic<bool, mozilla::ReleaseAcquire> marked;
jsbytecode data[1];
static SharedScriptData* new_(ExclusiveContext* cx, uint32_t codeLength,
uint32_t srcnotesLength, uint32_t natoms);
HeapPtrAtom* atoms() {
if (!natoms)
return nullptr;
return reinterpret_cast<HeapPtrAtom*>(data + length - sizeof(JSAtom*) * natoms);
static SharedScriptData* fromBytecode(const jsbytecode* bytecode) {
return (SharedScriptData*)(bytecode - offsetof(SharedScriptData, data));
SharedScriptData() = delete;
SharedScriptData(const SharedScriptData&) = delete;
struct ScriptBytecodeHasher
struct Lookup
jsbytecode* code;
uint32_t length;
explicit Lookup(SharedScriptData* ssd) : code(ssd->data), length(ssd->length) {}
static HashNumber hash(const Lookup& l) { return mozilla::HashBytes(l.code, l.length); }
static bool match(SharedScriptData* entry, const Lookup& lookup) {
if (entry->length != lookup.length)
return false;
return mozilla::PodEqual<jsbytecode>(entry->data, lookup.code, lookup.length);
typedef HashSet<SharedScriptData*,
SystemAllocPolicy> ScriptDataTable;
extern void
UnmarkScriptData(JSRuntime* rt);
extern void
SweepScriptData(JSRuntime* rt);
extern void
FreeScriptData(JSRuntime* rt);
struct ScriptAndCounts
/* This structure is stored and marked from the JSRuntime. */
JSScript* script;
ScriptCounts scriptCounts;
inline explicit ScriptAndCounts(JSScript* script);
inline ScriptAndCounts(ScriptAndCounts&& sac);
const PCCounts* maybeGetPCCounts(jsbytecode* pc) const {
return scriptCounts.maybeGetPCCounts(script->pcToOffset(pc));
const PCCounts* maybeGetThrowCounts(jsbytecode* pc) const {
return scriptCounts.maybeGetThrowCounts(script->pcToOffset(pc));
jit::IonScriptCounts* getIonCounts() const {
return scriptCounts.ionCounts_;
void trace(JSTracer* trc) {
TraceRoot(trc, &script, "ScriptAndCounts::script");
struct GSNCache;
GetSrcNote(GSNCache& cache, JSScript* script, jsbytecode* pc);
extern jssrcnote*
GetSrcNote(JSContext* cx, JSScript* script, jsbytecode* pc);
extern jsbytecode*
LineNumberToPC(JSScript* script, unsigned lineno);
extern JS_FRIEND_API(unsigned)
GetScriptLineExtent(JSScript* script);
} /* namespace js */
namespace js {
extern unsigned
PCToLineNumber(JSScript* script, jsbytecode* pc, unsigned* columnp = nullptr);
extern unsigned
PCToLineNumber(unsigned startLine, jssrcnote* notes, jsbytecode* code, jsbytecode* pc,
unsigned* columnp = nullptr);
* This function returns the file and line number of the script currently
* executing on cx. If there is no current script executing on cx (e.g., a
* native called directly through JSAPI (e.g., by setTimeout)), nullptr and 0
* are returned as the file and line. Additionally, this function avoids the
* full linear scan to compute line number when the caller guarantees that the
* script compilation occurs at a JSOP_EVAL/JSOP_SPREADEVAL.
enum LineOption {
extern void
DescribeScriptedCallerForCompilation(JSContext* cx, MutableHandleScript maybeScript,
const char** file, unsigned* linenop,
uint32_t* pcOffset, bool* mutedErrors,
CloneScriptIntoFunction(JSContext* cx, HandleObject enclosingScope, HandleFunction fun,
HandleScript src);
CloneGlobalScript(JSContext* cx, Handle<ScopeObject*> enclosingScope, HandleScript src);
} /* namespace js */
// JS::ubi::Nodes can point to js::LazyScripts; they're js::gc::Cell instances
// with no associated compartment.
namespace JS {
namespace ubi {
struct Concrete<js::LazyScript> : TracerConcrete<js::LazyScript> {
CoarseType coarseType() const final { return CoarseType::Script; }
Size size(mozilla::MallocSizeOf mallocSizeOf) const override;
const char* scriptFilename() const final;
explicit Concrete(js::LazyScript *ptr) : TracerConcrete<js::LazyScript>(ptr) { }
static void construct(void *storage, js::LazyScript *ptr) { new (storage) Concrete(ptr); }
} // namespace ubi
} // namespace JS
#endif /* jsscript_h */