https://github.com/mozilla/gecko-dev
Tip revision: 3795849304434b2df5f1e92143696411d7fa8efe authored by Sebastian Hengst on 31 October 2016, 18:59:07 UTC
Merge m-c to fx-team. r=merge a=merge
Merge m-c to fx-team. r=merge a=merge
Tip revision: 3795849
jsscript.h
/* -*- 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/. */
/* JS script descriptor. */
#ifndef jsscript_h
#define jsscript_h
#include "mozilla/Atomics.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/PodOperations.h"
#include "mozilla/Variant.h"
#include "jsatom.h"
#include "jsopcode.h"
#include "jstypes.h"
#include "frontend/NameAnalysisTypes.h"
#include "gc/Barrier.h"
#include "gc/Rooting.h"
#include "jit/IonCode.h"
#include "js/UbiNode.h"
#include "js/UniquePtr.h"
#include "vm/NativeObject.h"
#include "vm/Scope.h"
#include "vm/Shape.h"
#include "vm/SharedImmutableStringsCache.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 Debugger;
class LazyScript;
class ModuleObject;
class RegExpObject;
struct SourceCompressionTask;
class Shape;
namespace frontend {
struct BytecodeEmitter;
class FunctionBox;
class ModuleSharedContext;
} // namespace frontend
namespace detail {
// Do not call this directly! It is exposed for the friend declarations in
// this file.
bool
CopyScript(JSContext* cx, HandleScript src, HandleScript dst,
MutableHandle<GCVector<Scope*>> scopes);
} // 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 {
JSTRY_CATCH,
JSTRY_FINALLY,
JSTRY_FOR_IN,
JSTRY_FOR_OF,
JSTRY_LOOP
};
/*
* 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
// ScopeNote 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 NoScopeIndex.
//
struct ScopeNote {
// Sentinel index for no Scope.
static const uint32_t NoScopeIndex = UINT32_MAX;
// Sentinel index for no ScopeNote.
static const uint32_t NoScopeNoteIndex = UINT32_MAX;
uint32_t index; // Index of Scope in the scopes array, or
// NoScopeIndex 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 NoScopeNote.
};
struct ConstArray {
js::GCPtrValue* vector; // array of indexed constant values
uint32_t length;
};
struct ObjectArray {
js::GCPtrObject* vector; // Array of indexed objects.
uint32_t length; // Count of indexed objects.
};
struct ScopeArray {
js::GCPtrScope* vector; // Array of indexed scopes.
uint32_t length; // Count of indexed scopes.
};
struct TryNoteArray {
JSTryNote* vector; // Array of indexed try notes.
uint32_t length; // Count of indexed try notes.
};
struct ScopeNoteArray {
ScopeNote* vector; // Array of indexed ScopeNote records.
uint32_t length; // Count of indexed try notes.
};
class YieldOffsetArray {
friend bool
detail::CopyScript(JSContext* cx, HandleScript src, HandleScript dst,
MutableHandle<GCVector<Scope*>> scopes);
uint32_t* vector_; // Array of bytecode offsets.
uint32_t length_; // Count of bytecode offsets.
public:
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 ScriptCounts
{
public:
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);
private:
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*,
ScriptCounts*,
DefaultHasher<JSScript*>,
SystemAllocPolicy> ScriptCountsMap;
class DebugScript
{
friend class ::JSScript;
friend struct ::JSCompartment;
/*
* 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*,
DebugScript*,
DefaultHasher<JSScript*>,
SystemAllocPolicy> DebugScriptMap;
class ScriptSource;
struct ScriptSourceChunk
{
ScriptSource* ss;
uint32_t chunk;
ScriptSourceChunk()
: ss(nullptr), chunk(0)
{}
ScriptSourceChunk(ScriptSource* ss, uint32_t chunk)
: ss(ss), chunk(chunk)
{
MOZ_ASSERT(valid());;
}
bool valid() const { return ss != nullptr; }
bool operator==(const ScriptSourceChunk& other) const {
return ss == other.ss && chunk == other.chunk;
}
};
struct ScriptSourceChunkHasher
{
using Lookup = ScriptSourceChunk;
static HashNumber hash(const ScriptSourceChunk& ssc) {
return mozilla::AddToHash(DefaultHasher<ScriptSource*>::hash(ssc.ss), ssc.chunk);
}
static bool match(const ScriptSourceChunk& c1, const ScriptSourceChunk& c2) {
return c1 == c2;
}
};
class UncompressedSourceCache
{
typedef HashMap<ScriptSourceChunk,
UniqueTwoByteChars,
ScriptSourceChunkHasher,
SystemAllocPolicy> Map;
public:
// Hold an entry in the source data cache and prevent it from being purged on GC.
class AutoHoldEntry
{
UncompressedSourceCache* cache_;
ScriptSourceChunk sourceChunk_;
UniqueTwoByteChars charsToFree_;
public:
explicit AutoHoldEntry();
~AutoHoldEntry();
void holdChars(UniqueTwoByteChars chars);
private:
void holdEntry(UncompressedSourceCache* cache, const ScriptSourceChunk& sourceChunk);
void deferDelete(UniqueTwoByteChars chars);
const ScriptSourceChunk& sourceChunk() const { return sourceChunk_; }
friend class UncompressedSourceCache;
};
private:
UniquePtr<Map> map_;
AutoHoldEntry* holder_;
public:
UncompressedSourceCache() : holder_(nullptr) {}
const char16_t* lookup(const ScriptSourceChunk& ssc, AutoHoldEntry& asp);
bool put(const ScriptSourceChunk& ssc, UniqueTwoByteChars chars, AutoHoldEntry& asp);
void purge();
size_t sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf);
private:
void holdEntry(AutoHoldEntry& holder, const ScriptSourceChunk& ssc);
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.
struct Missing { };
struct Uncompressed
{
SharedImmutableTwoByteString string;
explicit Uncompressed(SharedImmutableTwoByteString&& str)
: string(mozilla::Move(str))
{ }
};
struct Compressed
{
SharedImmutableString raw;
size_t uncompressedLength;
Compressed(SharedImmutableString&& raw, size_t uncompressedLength)
: raw(mozilla::Move(raw))
, uncompressedLength(uncompressedLength)
{ }
};
using SourceType = mozilla::Variant<Missing, Uncompressed, Compressed>;
SourceType data;
// The filename of this script.
UniqueChars filename_;
UniqueTwoByteChars displayURL_;
UniqueTwoByteChars 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.
UniqueChars 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—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;
const char16_t* chunkChars(JSContext* cx, UncompressedSourceCache::AutoHoldEntry& holder,
size_t chunk);
public:
explicit ScriptSource()
: refs(0),
data(SourceType(Missing())),
filename_(nullptr),
displayURL_(nullptr),
sourceMapURL_(nullptr),
mutedErrors_(false),
introductionOffset_(0),
introducerFilename_(nullptr),
introductionType_(nullptr),
sourceRetrievable_(false),
argumentsNotIncluded_(false),
hasIntroductionOffset_(false)
{
}
~ScriptSource() {
MOZ_ASSERT(refs == 0);
}
void incref() { refs++; }
void decref() {
MOZ_ASSERT(refs != 0);
if (--refs == 0)
js_delete(this);
}
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 !data.is<Missing>(); }
bool hasCompressedSource() const { return data.is<Compressed>(); }
size_t length() const {
struct LengthMatcher
{
size_t match(const Uncompressed& u) {
return u.string.length();
}
size_t match(const Compressed& c) {
return c.uncompressedLength;
}
size_t match(const Missing& m) {
MOZ_CRASH("ScriptSource::length on a missing source");
return 0;
}
};
MOZ_ASSERT(hasSourceData());
return data.match(LengthMatcher());
}
bool argumentsNotIncluded() const {
MOZ_ASSERT(hasSourceData());
return argumentsNotIncluded_;
}
// Return a string containing the chars starting at |begin| and ending at
// |begin + len|.
const char16_t* chars(JSContext* cx, UncompressedSourceCache::AutoHoldEntry& asp,
size_t begin, size_t len);
JSFlatString* substring(JSContext* cx, size_t start, size_t stop);
JSFlatString* substringDontDeflate(JSContext* cx, size_t start, size_t stop);
void addSizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf,
JS::ScriptSourceInfo* info) const;
MOZ_MUST_USE bool setSource(ExclusiveContext* cx,
mozilla::UniquePtr<char16_t[], JS::FreePolicy>&& source,
size_t length);
void setSource(SharedImmutableTwoByteString&& string);
MOZ_MUST_USE bool setCompressedSource(
ExclusiveContext* cx,
mozilla::UniquePtr<char[], JS::FreePolicy>&& raw,
size_t rawLength,
size_t sourceLength);
void setCompressedSource(SharedImmutableString&& raw, size_t sourceLength);
// 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 {
MOZ_ASSERT(hasIntroductionType());
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() {
MOZ_ASSERT(hasDisplayURL());
return displayURL_.get();
}
// Source maps
bool setSourceMapURL(ExclusiveContext* cx, const char16_t* sourceMapURL);
bool hasSourceMapURL() const { return sourceMapURL_ != nullptr; }
const char16_t * sourceMapURL() {
MOZ_ASSERT(hasSourceMapURL());
return sourceMapURL_.get();
}
bool mutedErrors() const { return mutedErrors_; }
bool hasIntroductionOffset() const { return hasIntroductionOffset_; }
uint32_t introductionOffset() const {
MOZ_ASSERT(hasIntroductionOffset());
return introductionOffset_;
}
void setIntroductionOffset(uint32_t offset) {
MOZ_ASSERT(!hasIntroductionOffset());
MOZ_ASSERT(offset <= (uint32_t)INT32_MAX);
introductionOffset_ = offset;
hasIntroductionOffset_ = true;
}
};
class ScriptSourceHolder
{
ScriptSource* ss;
public:
ScriptSourceHolder()
: ss(nullptr)
{}
explicit ScriptSourceHolder(ScriptSource* ss)
: ss(ss)
{
ss->incref();
}
~ScriptSourceHolder()
{
if (ss)
ss->decref();
}
void reset(ScriptSource* newss) {
if (ss)
ss->decref();
ss = newss;
ss->incref();
}
ScriptSource* get() const {
return ss;
}
};
class ScriptSourceObject : public NativeObject
{
static const ClassOps classOps_;
public:
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 {
MOZ_ASSERT(!getReservedSlot(ELEMENT_PROPERTY_SLOT).isMagic());
return getReservedSlot(ELEMENT_PROPERTY_SLOT);
}
JSScript* introductionScript() const {
if (getReservedSlot(INTRODUCTION_SCRIPT_SLOT).isUndefined())
return nullptr;
void* untyped = getReservedSlot(INTRODUCTION_SCRIPT_SLOT).toPrivate();
MOZ_ASSERT(untyped);
return static_cast<JSScript*>(untyped);
}
private:
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 };
enum FunctionAsyncKind { SyncFunction, AsyncFunction };
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);
}
static inline unsigned
AsyncKindAsBits(FunctionAsyncKind asyncKind) {
return static_cast<unsigned>(asyncKind);
}
static inline FunctionAsyncKind
AsyncKindFromBits(unsigned val) {
MOZ_ASSERT(val <= AsyncFunction);
return static_cast<FunctionAsyncKind>(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>
bool
XDRScript(XDRState<mode>* xdr, HandleScope enclosingScope, HandleScript enclosingScript,
HandleFunction fun, MutableHandleScript scriptp);
template<XDRMode mode>
bool
XDRLazyScript(XDRState<mode>* xdr, HandleScope enclosingScope, HandleScript enclosingScript,
HandleFunction fun, MutableHandle<LazyScript*> lazy);
/*
* Code any constant value.
*/
template<XDRMode mode>
bool
XDRScriptConst(XDRState<mode>* xdr, MutableHandleValue vp);
/*
* Common data that can be shared between many scripts in a single runtime.
*/
class SharedScriptData
{
// This class is reference counted as follows: each pointer from a JSScript
// counts as one reference plus there may be one reference from the shared
// script data table.
mozilla::Atomic<uint32_t> refCount_;
uint32_t dataLength_;
uint32_t natoms_;
uint32_t codeLength_;
uintptr_t data_[1];
public:
static SharedScriptData* new_(ExclusiveContext* cx, uint32_t codeLength,
uint32_t srcnotesLength, uint32_t natoms);
uint32_t refCount() const {
return refCount_;
}
void incRefCount() {
refCount_++;
}
void decRefCount() {
MOZ_ASSERT(refCount_ != 0);
refCount_--;
if (refCount_ == 0)
js_free(this);
}
uint32_t dataLength() const {
return dataLength_;
}
uint8_t* data() {
return reinterpret_cast<uint8_t*>(data_);
}
uint32_t natoms() const {
return natoms_;
}
GCPtrAtom* atoms() {
if (!natoms_)
return nullptr;
return reinterpret_cast<GCPtrAtom*>(data());
}
uint32_t codeLength() const {
return codeLength_;
}
jsbytecode* code() {
return reinterpret_cast<jsbytecode*>(data() + natoms_ * sizeof(GCPtrAtom));
}
void traceChildren(JSTracer* trc);
private:
SharedScriptData() = delete;
SharedScriptData(const SharedScriptData&) = delete;
SharedScriptData& operator=(const SharedScriptData&) = delete;
};
struct ScriptBytecodeHasher
{
struct Lookup
{
const uint8_t* data;
uint32_t length;
explicit Lookup(SharedScriptData* ssd) : data(ssd->data()), length(ssd->dataLength()) {}
};
static HashNumber hash(const Lookup& l) { return mozilla::HashBytes(l.data, l.length); }
static bool match(SharedScriptData* entry, const Lookup& lookup) {
if (entry->dataLength() != lookup.length)
return false;
return mozilla::PodEqual<uint8_t>(entry->data(), lookup.data, lookup.length);
}
};
typedef HashSet<SharedScriptData*,
ScriptBytecodeHasher,
SystemAllocPolicy> ScriptDataTable;
extern void
SweepScriptData(JSRuntime* rt, AutoLockForExclusiveAccess& lock);
extern void
FreeScriptData(JSRuntime* rt, AutoLockForExclusiveAccess& lock);
} /* namespace js */
class JSScript : public js::gc::TenuredCell
{
template <js::XDRMode mode>
friend
bool
js::XDRScript(js::XDRState<mode>* xdr, js::HandleScope enclosingScope,
js::HandleScript enclosingScript, js::HandleFunction fun,
js::MutableHandleScript scriptp);
friend bool
js::detail::CopyScript(JSContext* cx, js::HandleScript src, js::HandleScript dst,
js::MutableHandle<JS::GCVector<js::Scope*>> scopes);
private:
js::SharedScriptData* scriptData_;
public:
uint8_t* data; /* pointer to variable-length data array (see
comment above Create() for details) */
JSCompartment* compartment_;
private:
/* 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::GCPtrObject sourceObject_;
/*
* Information attached by Ion. Nexto a valid IonScript this could be
* ION_DISABLED_SCRIPT, ION_COMPILING_SCRIPT or ION_PENDING_SCRIPT.
* 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 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 nfixed_; /* fixed frame slots */
uint32_t nslots_; /* slots plus maximum stack depth */
uint32_t bodyScopeIndex_; /* index into the scopes array of the body scope */
/* Range of characters in scriptSource which contains this script's source. */
uint32_t sourceStart_;
uint32_t sourceEnd_;
// 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.
mozilla::Atomic<uint32_t, mozilla::Relaxed> warmUpCount;
// 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.
public:
// The kinds of the optional arrays.
enum ArrayKind {
CONSTS,
OBJECTS,
TRYNOTES,
SCOPENOTES,
ARRAY_KIND_BITS
};
private:
// 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;
// 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;
// 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 hadOverflowBailout_: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;
bool functionHasExtraBodyVarScope_: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;
bool isDefaultClassConstructor_:1;
bool isAsync_:1;
// Add padding so JSScript is gc::Cell aligned. Make padding protected
// instead of private to suppress -Wunused-private-field compiler warnings.
protected:
#if JS_BITS_PER_WORD == 32
// Currently no padding is needed.
#endif
//
// End of fields. Start methods.
//
public:
static JSScript* Create(js::ExclusiveContext* cx,
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()
// 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 nscopes, uint32_t nconsts, uint32_t nobjects,
uint32_t ntrynotes, uint32_t nscopenotes, uint32_t nyieldoffsets,
uint32_t nTypeSets);
private:
static void initFromFunctionBox(js::ExclusiveContext* cx, js::HandleScript script,
js::frontend::FunctionBox* funbox);
static void initFromModuleContext(js::ExclusiveContext* cx, js::HandleScript script,
js::frontend::ModuleSharedContext* modulesc);
public:
static bool fullyInitFromEmitter(js::ExclusiveContext* cx, js::HandleScript script,
js::frontend::BytecodeEmitter* bce);
// Initialize the Function.prototype script.
static bool initFunctionPrototype(js::ExclusiveContext* cx, js::HandleScript script,
JS::HandleFunction functionProto);
#ifdef DEBUG
private:
// Assert that jump targets are within the code array of the script.
void assertValidJumpTargets() const;
#endif
public:
inline JSPrincipals* principals();
JSCompartment* compartment() const { return compartment_; }
JSCompartment* maybeCompartment() const { return compartment(); }
void setVersion(JSVersion v) { version = v; }
js::SharedScriptData* scriptData() {
return scriptData_;
}
// Script bytecode is immutable after creation.
jsbytecode* code() const {
if (!scriptData_)
return nullptr;
return scriptData_->code();
}
size_t length() const {
MOZ_ASSERT(scriptData_);
return scriptData_->codeLength();
}
jsbytecode* codeEnd() const { return code() + length(); }
jsbytecode* lastPC() const {
jsbytecode* pc = codeEnd() - js::JSOP_RETRVAL_LENGTH;
MOZ_ASSERT(*pc == JSOP_RETRVAL);
return pc;
}
bool containsPC(const jsbytecode* pc) const {
return pc >= code() && pc < codeEnd();
}
size_t pcToOffset(const jsbytecode* pc) const {
MOZ_ASSERT(containsPC(pc));
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 and
// module code) and block-scoped locals (in all kinds of code).
size_t nfixed() const {
return nfixed_;
}
// Number of fixed slots reserved for slots that are always live. Only
// nonzero for function or module code.
size_t numAlwaysLiveFixedSlots() const {
if (bodyScope()->is<js::FunctionScope>())
return bodyScope()->as<js::FunctionScope>().nextFrameSlot();
if (bodyScope()->is<js::ModuleScope>())
return bodyScope()->as<js::ModuleScope>().nextFrameSlot();
return 0;
}
// Calculate the number of fixed slots that are live at a particular bytecode.
size_t calculateLiveFixed(jsbytecode* pc);
size_t nslots() const {
return nslots_;
}
unsigned numArgs() const {
if (bodyScope()->is<js::FunctionScope>())
return bodyScope()->as<js::FunctionScope>().numPositionalFormalParameters();
return 0;
}
inline js::Shape* initialEnvironmentShape() const;
bool functionHasParameterExprs() const {
// Only functions have parameters.
js::Scope* scope = bodyScope();
if (!scope->is<js::FunctionScope>())
return false;
return scope->as<js::FunctionScope>().hasParameterExprs();
}
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 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 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 hadOverflowBailout() const {
return hadOverflowBailout_;
}
bool uninlineable() const {
return uninlineable_;
}
bool invalidatedIdempotentCache() const {
return invalidatedIdempotentCache_;
}
bool failedLexicalCheck() const {
return failedLexicalCheck_;
}
bool isDefaultClassConstructor() const {
return isDefaultClassConstructor_;
}
void setFailedBoundsCheck() { failedBoundsCheck_ = true; }
void setFailedShapeGuard() { failedShapeGuard_ = true; }
void setHadFrequentBailouts() { hadFrequentBailouts_ = true; }
void setHadOverflowBailout() { hadOverflowBailout_ = true; }
void setUninlineable() { uninlineable_ = true; }
void setInvalidatedIdempotentCache() { invalidatedIdempotentCache_ = true; }
void setFailedLexicalCheck() { failedLexicalCheck_ = true; }
void setIsDefaultClassConstructor() { isDefaultClassConstructor_ = 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_;
}
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.
MOZ_ASSERT(!isGenerator());
generatorKindBits_ = GeneratorKindAsBits(kind);
}
js::FunctionAsyncKind asyncKind() const {
return isAsync_ ? js::AsyncFunction : js::SyncFunction;
}
void setAsyncKind(js::FunctionAsyncKind kind) {
isAsync_ = kind == js::AsyncFunction;
}
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 {
MOZ_ASSERT(analyzedArgsUsage());
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 &&
ion != ION_PENDING_SCRIPT;
MOZ_ASSERT_IF(res, baseline);
return res;
}
bool canIonCompile() const {
return ion != ION_DISABLED_SCRIPT;
}
bool isIonCompilingOffThread() const {
return ion == ION_COMPILING_SCRIPT;
}
js::jit::IonScript* ionScript() const {
MOZ_ASSERT(hasIonScript());
return ion;
}
js::jit::IonScript* maybeIonScript() const {
return ion;
}
js::jit::IonScript* const* addressOfIonScript() const {
return &ion;
}
void setIonScript(JSRuntime* maybeRuntime, 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 {
MOZ_ASSERT(hasBaselineScript());
return baseline;
}
inline void setBaselineScript(JSRuntime* maybeRuntime, js::jit::BaselineScript* baselineScript);
void updateBaselineOrIonRaw(JSRuntime* maybeRuntime);
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() &&
!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 {
if (bodyScope()->is<js::FunctionScope>())
return bodyScope()->as<js::FunctionScope>().canonicalFunction();
return nullptr;
}
/*
* 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 {
if (bodyScope()->is<js::ModuleScope>())
return bodyScope()->as<js::ModuleScope>().module();
return nullptr;
}
bool isGlobalOrEvalCode() const {
return bodyScope()->is<js::GlobalScope>() || bodyScope()->is<js::EvalScope>();
}
bool isGlobalCode() const {
return bodyScope()->is<js::GlobalScope>();
}
// 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(); }
public:
/* Return whether this script was compiled for 'eval' */
bool isForEval() const {
MOZ_ASSERT_IF(isCachedEval() || isActiveEval(), bodyScope()->is<js::EvalScope>());
return isCachedEval() || isActiveEval();
}
/* Return whether this is a 'direct eval' script in a function scope. */
bool isDirectEvalInFunction() const {
if (!isForEval())
return false;
return bodyScope()->hasOnChain(js::ScopeKind::Function);
}
/*
* 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;
uint32_t bodyScopeIndex() const {
return bodyScopeIndex_;
}
js::Scope* bodyScope() const {
return getScope(bodyScopeIndex_);
}
js::Scope* outermostScope() const {
// The body scope may not be the outermost scope in the script when
// the decl env scope is present.
size_t index = 0;
return getScope(index);
}
bool functionHasExtraBodyVarScope() const {
MOZ_ASSERT_IF(functionHasExtraBodyVarScope_, functionHasParameterExprs());
return functionHasExtraBodyVarScope_;
}
js::VarScope* functionExtraBodyVarScope() const {
MOZ_ASSERT(functionHasExtraBodyVarScope());
for (uint32_t i = 0; i < scopes()->length; i++) {
js::Scope* scope = getScope(i);
if (scope->kind() == js::ScopeKind::FunctionBodyVar)
return &scope->as<js::VarScope>();
}
MOZ_CRASH("Function extra body var scope not found");
}
inline js::LexicalScope* maybeNamedLambdaScope() const;
js::Scope* enclosingScope() const {
return outermostScope()->enclosing();
}
private:
bool makeTypes(JSContext* cx);
bool createScriptData(js::ExclusiveContext* cx, uint32_t codeLength, uint32_t srcnotesLength,
uint32_t natoms);
bool shareScriptData(js::ExclusiveContext* cx);
void freeScriptData();
void setScriptData(js::SharedScriptData* data);
public:
uint32_t getWarmUpCount() const { return warmUpCount; }
uint32_t incWarmUpCounter(uint32_t amount = 1) { return warmUpCount += amount; }
uint32_t* addressOfWarmUpCounter() { return reinterpret_cast<uint32_t*>(&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; }
public:
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() const {
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) const {
return hasArrayBits & (1 << kind);
}
void setHasArray(ArrayKind kind) { hasArrayBits |= (1 << kind); }
void cloneHasArray(JSScript* script) { hasArrayBits = script->hasArrayBits; }
bool hasConsts() const { return hasArray(CONSTS); }
bool hasObjects() const { return hasArray(OBJECTS); }
bool hasTrynotes() const { return hasArray(TRYNOTES); }
bool hasScopeNotes() const { return hasArray(SCOPENOTES); }
bool hasYieldOffsets() const { return isGenerator(); }
#define OFF(fooOff, hasFoo, t) (fooOff() + (hasFoo() ? sizeof(t) : 0))
size_t scopesOffset() const { return 0; }
size_t constsOffset() const { return scopesOffset() + sizeof(js::ScopeArray); }
size_t objectsOffset() const { return OFF(constsOffset, hasConsts, js::ConstArray); }
size_t trynotesOffset() const { return OFF(objectsOffset, hasObjects, js::ObjectArray); }
size_t scopeNotesOffset() const { return OFF(trynotesOffset, hasTrynotes, js::TryNoteArray); }
size_t yieldOffsetsOffset() const { return OFF(scopeNotesOffset, hasScopeNotes, js::ScopeNoteArray); }
#undef OFF
size_t dataSize() const { return dataSize_; }
js::ConstArray* consts() {
MOZ_ASSERT(hasConsts());
return reinterpret_cast<js::ConstArray*>(data + constsOffset());
}
js::ObjectArray* objects() {
MOZ_ASSERT(hasObjects());
return reinterpret_cast<js::ObjectArray*>(data + objectsOffset());
}
js::ScopeArray* scopes() const {
return reinterpret_cast<js::ScopeArray*>(data + scopesOffset());
}
js::TryNoteArray* trynotes() const {
MOZ_ASSERT(hasTrynotes());
return reinterpret_cast<js::TryNoteArray*>(data + trynotesOffset());
}
js::ScopeNoteArray* scopeNotes() {
MOZ_ASSERT(hasScopeNotes());
return reinterpret_cast<js::ScopeNoteArray*>(data + scopeNotesOffset());
}
js::YieldOffsetArray& yieldOffsets() {
MOZ_ASSERT(hasYieldOffsets());
return *reinterpret_cast<js::YieldOffsetArray*>(data + yieldOffsetsOffset());
}
bool hasLoops();
size_t natoms() const {
MOZ_ASSERT(scriptData_);
return scriptData_->natoms();
}
js::GCPtrAtom* atoms() const {
MOZ_ASSERT(scriptData_);
return scriptData_->atoms();
}
js::GCPtrAtom& getAtom(size_t index) const {
MOZ_ASSERT(index < natoms());
return atoms()[index];
}
js::GCPtrAtom& 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);
MOZ_ASSERT(arr->vector[index]->isTenured());
return arr->vector[index];
}
JSObject* getObject(jsbytecode* pc) {
MOZ_ASSERT(containsPC(pc) && containsPC(pc + sizeof(uint32_t)));
return getObject(GET_UINT32_INDEX(pc));
}
js::Scope* getScope(size_t index) const {
js::ScopeArray* array = scopes();
MOZ_ASSERT(index < array->length);
return array->vector[index];
}
js::Scope* getScope(jsbytecode* pc) const {
// This method is used to get a scope directly using a JSOp with an
// index. To search through ScopeNotes to look for a Scope using pc,
// use lookupScope.
MOZ_ASSERT(containsPC(pc) && containsPC(pc + sizeof(uint32_t)));
MOZ_ASSERT(js::JOF_OPTYPE(JSOp(*pc)) == JOF_SCOPE,
"Did you mean to use lookupScope(pc)?");
return getScope(GET_UINT32_INDEX(pc));
}
JSVersion getVersion() const {
return JSVersion(version);
}
inline JSFunction* getFunction(size_t index);
JSFunction* function() const {
if (functionNonDelazifying())
return functionNonDelazifying();
return nullptr;
}
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 3 functions find the static scope just before the
// execution of the instruction pointed to by pc.
js::Scope* lookupScope(jsbytecode* pc);
js::Scope* innermostScope(jsbytecode* pc);
js::Scope* innermostScope() { return innermostScope(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)
++pc;
return JSOp(*pc) == JSOP_RETRVAL;
}
bool formalIsAliased(unsigned argSlot);
bool formalLivesInArgumentsObject(unsigned argSlot);
private:
/* 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);
public:
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; }
#endif
void finalize(js::FreeOp* fop);
static const JS::TraceKind TraceKind = JS::TraceKind::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_;
public:
explicit AutoDelazify(JSContext* cx, JS::HandleFunction fun = nullptr)
: script_(cx)
, cx_(cx)
{
holdScript(fun);
}
~AutoDelazify()
{
dropScript();
}
void operator=(JS::HandleFunction fun)
{
dropScript();
holdScript(fun);
}
operator JS::HandleScript() const { return script_; }
explicit operator bool() const { return script_; }
private:
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 {
// Information about a script which may be (or has been) lazily compiled to
// bytecode from its source.
class LazyScript : public gc::TenuredCell
{
private:
// 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.
GCPtrFunction function_;
// Scope in which the script is nested.
GCPtrScope enclosingScope_;
// ScriptSourceObject. We leave this set to nullptr until we generate
// bytecode for our immediate parent. This is never a CCW; we don't clone
// LazyScripts into other compartments.
GCPtrObject 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.
protected:
#if JS_BITS_PER_WORD == 32
uint32_t padding;
#endif
private:
struct PackedView {
// Assorted bits that should really be in ScriptSourceObject.
uint32_t version : 8;
uint32_t shouldDeclareArguments : 1;
uint32_t hasThisBinding : 1;
uint32_t isAsync : 1;
uint32_t numClosedOverBindings : 21;
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 closedOverBindings 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);
public:
static const uint32_t NumClosedOverBindingsLimit = 1 << 22;
static const uint32_t NumInnerFunctionsLimit = 1 << 20;
// Create a LazyScript and initialize closedOverBindings and innerFunctions
// with the provided vectors.
static LazyScript* Create(ExclusiveContext* cx, HandleFunction fun,
const frontend::AtomVector& closedOverBindings,
Handle<GCVector<JSFunction*, 8>> innerFunctions,
JSVersion version, uint32_t begin, uint32_t end,
uint32_t lineno, uint32_t column);
// Create a LazyScript and initialize the closedOverBindings 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 enclosingScript and enclosingScope arguments may be null if the
// enclosing function is also lazy.
static LazyScript* Create(ExclusiveContext* cx, HandleFunction fun,
HandleScript script, HandleScope enclosingScope,
HandleScript enclosingScript,
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_);
}
Scope* enclosingScope() const {
return enclosingScope_;
}
ScriptSourceObject* sourceObject() const;
ScriptSource* scriptSource() const {
return sourceObject()->source();
}
ScriptSource* maybeForwardedScriptSource() const;
bool mutedErrors() const {
return scriptSource()->mutedErrors();
}
JSVersion version() const {
JS_STATIC_ASSERT(JSVERSION_UNKNOWN == -1);
return (p_.version == JS_BIT(8) - 1) ? JSVERSION_UNKNOWN : JSVersion(p_.version);
}
void setEnclosingScopeAndSource(Scope* enclosingScope, ScriptSourceObject* sourceObject);
uint32_t numClosedOverBindings() const {
return p_.numClosedOverBindings;
}
JSAtom** closedOverBindings() {
return (JSAtom**)table_;
}
uint32_t numInnerFunctions() const {
return p_.numInnerFunctions;
}
GCPtrFunction* innerFunctions() {
return (GCPtrFunction*)&closedOverBindings()[numClosedOverBindings()];
}
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.
MOZ_ASSERT(!isGenerator());
// Legacy generators cannot currently be lazy.
MOZ_ASSERT(kind != LegacyGenerator);
p_.generatorKindBits = GeneratorKindAsBits(kind);
}
FunctionAsyncKind asyncKind() const {
return p_.isAsync ? AsyncFunction : SyncFunction;
}
void setAsyncKind(FunctionAsyncKind kind) {
p_.isAsync = kind == AsyncFunction;
}
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;
}
bool shouldDeclareArguments() const {
return p_.shouldDeclareArguments;
}
void setShouldDeclareArguments() {
p_.shouldDeclareArguments = true;
}
bool hasThisBinding() const {
return p_.hasThisBinding;
}
void setHasThisBinding() {
p_.hasThisBinding = 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);
static const JS::TraceKind TraceKind = JS::TraceKind::LazyScript;
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 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;
jssrcnote*
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 {
CALLED_FROM_JSOP_EVAL,
NOT_CALLED_FROM_JSOP_EVAL
};
extern void
DescribeScriptedCallerForCompilation(JSContext* cx, MutableHandleScript maybeScript,
const char** file, unsigned* linenop,
uint32_t* pcOffset, bool* mutedErrors,
LineOption opt = NOT_CALLED_FROM_JSOP_EVAL);
JSScript*
CloneScriptIntoFunction(JSContext* cx, HandleScope enclosingScope, HandleFunction fun,
HandleScript src);
JSScript*
CloneGlobalScript(JSContext* cx, ScopeKind scopeKind, 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 {
template<>
class Concrete<js::LazyScript> : TracerConcrete<js::LazyScript> {
protected:
explicit Concrete(js::LazyScript *ptr) : TracerConcrete<js::LazyScript>(ptr) { }
public:
static void construct(void *storage, js::LazyScript *ptr) { new (storage) Concrete(ptr); }
CoarseType coarseType() const final { return CoarseType::Script; }
Size size(mozilla::MallocSizeOf mallocSizeOf) const override;
const char* scriptFilename() const final;
const char16_t* typeName() const override { return concreteTypeName; }
static const char16_t concreteTypeName[];
};
} // namespace ubi
} // namespace JS
#endif /* jsscript_h */
