https://github.com/mozilla/gecko-dev
Tip revision: eb24259e00e59d852adfdfc21432f959dfa206f7 authored by ffxbld on 26 June 2015, 06:05:46 UTC
Added FENNEC_39_0_RELEASE FENNEC_39_0_BUILD2 tag(s) for changeset 3a9878cc0371. DONTBUILD CLOSED TREE a=release
Added FENNEC_39_0_RELEASE FENNEC_39_0_BUILD2 tag(s) for changeset 3a9878cc0371. DONTBUILD CLOSED TREE a=release
Tip revision: eb24259
jsscript.cpp
/* -*- 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 operations.
*/
#include "jsscriptinlines.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/MathAlgorithms.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/PodOperations.h"
#include <string.h>
#include "jsapi.h"
#include "jsatom.h"
#include "jscntxt.h"
#include "jsfun.h"
#include "jsgc.h"
#include "jsobj.h"
#include "jsopcode.h"
#include "jsprf.h"
#include "jstypes.h"
#include "jsutil.h"
#include "jswrapper.h"
#include "frontend/BytecodeCompiler.h"
#include "frontend/BytecodeEmitter.h"
#include "frontend/SharedContext.h"
#include "gc/Marking.h"
#include "jit/BaselineJIT.h"
#include "jit/Ion.h"
#include "jit/IonCode.h"
#include "js/MemoryMetrics.h"
#include "js/Utility.h"
#include "vm/ArgumentsObject.h"
#include "vm/Compression.h"
#include "vm/Debugger.h"
#include "vm/Opcodes.h"
#include "vm/SelfHosting.h"
#include "vm/Shape.h"
#include "vm/Xdr.h"
#include "jsfuninlines.h"
#include "jsobjinlines.h"
#include "vm/ScopeObject-inl.h"
#include "vm/Stack-inl.h"
using namespace js;
using namespace js::gc;
using namespace js::frontend;
using mozilla::PodCopy;
using mozilla::PodZero;
using mozilla::RotateLeft;
/* static */ BindingIter
Bindings::argumentsBinding(ExclusiveContext* cx, InternalBindingsHandle bindings)
{
HandlePropertyName arguments = cx->names().arguments;
BindingIter bi(bindings);
while (bi->name() != arguments)
bi++;
return bi;
}
bool
Bindings::initWithTemporaryStorage(ExclusiveContext* cx, InternalBindingsHandle self,
uint32_t numArgs, uint32_t numVars,
uint32_t numBodyLevelLexicals, uint32_t numBlockScoped,
uint32_t numUnaliasedVars, uint32_t numUnaliasedBodyLevelLexicals,
Binding* bindingArray)
{
MOZ_ASSERT(!self->callObjShape_);
MOZ_ASSERT(self->bindingArrayAndFlag_ == TEMPORARY_STORAGE_BIT);
MOZ_ASSERT(!(uintptr_t(bindingArray) & TEMPORARY_STORAGE_BIT));
MOZ_ASSERT(numArgs <= ARGC_LIMIT);
MOZ_ASSERT(numVars <= LOCALNO_LIMIT);
MOZ_ASSERT(numBlockScoped <= LOCALNO_LIMIT);
MOZ_ASSERT(numBodyLevelLexicals <= LOCALNO_LIMIT);
mozilla::DebugOnly<uint64_t> totalSlots = uint64_t(numVars) +
uint64_t(numBodyLevelLexicals) +
uint64_t(numBlockScoped);
MOZ_ASSERT(totalSlots <= LOCALNO_LIMIT);
MOZ_ASSERT(UINT32_MAX - numArgs >= totalSlots);
MOZ_ASSERT(numUnaliasedVars <= numVars);
MOZ_ASSERT(numUnaliasedBodyLevelLexicals <= numBodyLevelLexicals);
self->bindingArrayAndFlag_ = uintptr_t(bindingArray) | TEMPORARY_STORAGE_BIT;
self->numArgs_ = numArgs;
self->numVars_ = numVars;
self->numBodyLevelLexicals_ = numBodyLevelLexicals;
self->numBlockScoped_ = numBlockScoped;
self->numUnaliasedVars_ = numUnaliasedVars;
self->numUnaliasedBodyLevelLexicals_ = numUnaliasedBodyLevelLexicals;
// Get the initial shape to use when creating CallObjects for this script.
// After creation, a CallObject's shape may change completely (via direct eval() or
// other operations that mutate the lexical scope). However, since the
// lexical bindings added to the initial shape are permanent and the
// allocKind/nfixed of a CallObject cannot change, one may assume that the
// slot location (whether in the fixed or dynamic slots) of a variable is
// the same as in the initial shape. (This is assumed by the interpreter and
// JITs when interpreting/compiling aliasedvar ops.)
// Since unaliased variables are, by definition, only accessed by local
// operations and never through the scope chain, only give shapes to
// aliased variables. While the debugger may observe any scope object at
// any time, such accesses are mediated by DebugScopeProxy (see
// DebugScopeProxy::handleUnaliasedAccess).
uint32_t nslots = CallObject::RESERVED_SLOTS;
uint32_t aliasedBodyLevelLexicalBegin = UINT16_MAX;
for (BindingIter bi(self); bi; bi++) {
if (bi->aliased()) {
// Per ES6, lexical bindings cannot be accessed until
// initialized. Remember the first aliased slot that is a
// body-level lexical, so that they may be initialized to sentinel
// magic values.
if (numBodyLevelLexicals > 0 &&
nslots < aliasedBodyLevelLexicalBegin &&
bi.isBodyLevelLexical() &&
bi.localIndex() >= numVars)
{
aliasedBodyLevelLexicalBegin = nslots;
}
nslots++;
}
}
self->aliasedBodyLevelLexicalBegin_ = aliasedBodyLevelLexicalBegin;
// Put as many of nslots inline into the object header as possible.
uint32_t nfixed = gc::GetGCKindSlots(gc::GetGCObjectKind(nslots));
// Start with the empty shape and then append one shape per aliased binding.
RootedShape shape(cx,
EmptyShape::getInitialShape(cx, &CallObject::class_, TaggedProto(nullptr),
nfixed, BaseShape::QUALIFIED_VAROBJ | BaseShape::DELEGATE));
if (!shape)
return false;
#ifdef DEBUG
HashSet<PropertyName*> added(cx);
if (!added.init())
return false;
#endif
uint32_t slot = CallObject::RESERVED_SLOTS;
for (BindingIter bi(self); bi; bi++) {
if (!bi->aliased())
continue;
#ifdef DEBUG
// The caller ensures no duplicate aliased names.
MOZ_ASSERT(!added.has(bi->name()));
if (!added.put(bi->name()))
return false;
#endif
StackBaseShape stackBase(cx, &CallObject::class_,
BaseShape::QUALIFIED_VAROBJ | BaseShape::DELEGATE);
UnownedBaseShape* base = BaseShape::getUnowned(cx, stackBase);
if (!base)
return false;
unsigned attrs = JSPROP_PERMANENT |
JSPROP_ENUMERATE |
(bi->kind() == Binding::CONSTANT ? JSPROP_READONLY : 0);
StackShape child(base, NameToId(bi->name()), slot, attrs, 0);
shape = cx->compartment()->propertyTree.getChild(cx, shape, child);
if (!shape)
return false;
MOZ_ASSERT(slot < nslots);
slot++;
}
MOZ_ASSERT(slot == nslots);
MOZ_ASSERT(!shape->inDictionary());
self->callObjShape_.init(shape);
return true;
}
uint8_t*
Bindings::switchToScriptStorage(Binding* newBindingArray)
{
MOZ_ASSERT(bindingArrayUsingTemporaryStorage());
MOZ_ASSERT(!(uintptr_t(newBindingArray) & TEMPORARY_STORAGE_BIT));
if (count() > 0)
PodCopy(newBindingArray, bindingArray(), count());
bindingArrayAndFlag_ = uintptr_t(newBindingArray);
return reinterpret_cast<uint8_t*>(newBindingArray + count());
}
bool
Bindings::clone(JSContext* cx, InternalBindingsHandle self,
uint8_t* dstScriptData, HandleScript srcScript)
{
/* The clone has the same bindingArray_ offset as 'src'. */
Bindings& src = srcScript->bindings;
ptrdiff_t off = (uint8_t*)src.bindingArray() - srcScript->data;
MOZ_ASSERT(off >= 0);
MOZ_ASSERT(size_t(off) <= srcScript->dataSize());
Binding* dstPackedBindings = (Binding*)(dstScriptData + off);
/*
* Since atoms are shareable throughout the runtime, we can simply copy
* the source's bindingArray directly.
*/
if (!initWithTemporaryStorage(cx, self, src.numArgs(), src.numVars(),
src.numBodyLevelLexicals(),
src.numBlockScoped(),
src.numUnaliasedVars(),
src.numUnaliasedBodyLevelLexicals(),
src.bindingArray()))
{
return false;
}
self->switchToScriptStorage(dstPackedBindings);
return true;
}
/* static */ Bindings
GCMethods<Bindings>::initial()
{
return Bindings();
}
template<XDRMode mode>
static bool
XDRScriptBindings(XDRState<mode>* xdr, LifoAllocScope& las, uint16_t numArgs, uint32_t numVars,
uint16_t numBodyLevelLexicals, uint16_t numBlockScoped,
uint32_t numUnaliasedVars, uint16_t numUnaliasedBodyLevelLexicals,
HandleScript script)
{
JSContext* cx = xdr->cx();
if (mode == XDR_ENCODE) {
for (BindingIter bi(script); bi; bi++) {
RootedAtom atom(cx, bi->name());
if (!XDRAtom(xdr, &atom))
return false;
}
for (BindingIter bi(script); bi; bi++) {
uint8_t u8 = (uint8_t(bi->kind()) << 1) | uint8_t(bi->aliased());
if (!xdr->codeUint8(&u8))
return false;
}
} else {
uint32_t nameCount = numArgs + numVars + numBodyLevelLexicals;
AutoValueVector atoms(cx);
if (!atoms.resize(nameCount))
return false;
for (uint32_t i = 0; i < nameCount; i++) {
RootedAtom atom(cx);
if (!XDRAtom(xdr, &atom))
return false;
atoms[i].setString(atom);
}
Binding* bindingArray = las.alloc().newArrayUninitialized<Binding>(nameCount);
if (!bindingArray)
return false;
for (uint32_t i = 0; i < nameCount; i++) {
uint8_t u8;
if (!xdr->codeUint8(&u8))
return false;
PropertyName* name = atoms[i].toString()->asAtom().asPropertyName();
Binding::Kind kind = Binding::Kind(u8 >> 1);
bool aliased = bool(u8 & 1);
bindingArray[i] = Binding(name, kind, aliased);
}
InternalBindingsHandle bindings(script, &script->bindings);
if (!Bindings::initWithTemporaryStorage(cx, bindings, numArgs, numVars,
numBodyLevelLexicals, numBlockScoped,
numUnaliasedVars, numUnaliasedBodyLevelLexicals,
bindingArray))
{
return false;
}
}
return true;
}
bool
Bindings::bindingIsAliased(uint32_t bindingIndex)
{
MOZ_ASSERT(bindingIndex < count());
return bindingArray()[bindingIndex].aliased();
}
void
Bindings::trace(JSTracer* trc)
{
if (callObjShape_)
MarkShape(trc, &callObjShape_, "callObjShape");
/*
* As the comment in Bindings explains, bindingsArray may point into freed
* storage when bindingArrayUsingTemporaryStorage so we don't mark it.
* Note: during compilation, atoms are already kept alive by gcKeepAtoms.
*/
if (bindingArrayUsingTemporaryStorage())
return;
for (Binding* b = bindingArray(), *end = b + count(); b != end; b++) {
PropertyName* name = b->name();
MarkStringUnbarriered(trc, &name, "bindingArray");
}
}
template<XDRMode mode>
bool
js::XDRScriptConst(XDRState<mode>* xdr, MutableHandleValue vp)
{
JSContext* cx = xdr->cx();
/*
* A script constant can be an arbitrary primitive value as they are used
* to implement JSOP_LOOKUPSWITCH. But they cannot be objects, see
* bug 407186.
*/
enum ConstTag {
SCRIPT_INT = 0,
SCRIPT_DOUBLE = 1,
SCRIPT_ATOM = 2,
SCRIPT_TRUE = 3,
SCRIPT_FALSE = 4,
SCRIPT_NULL = 5,
SCRIPT_OBJECT = 6,
SCRIPT_VOID = 7,
SCRIPT_HOLE = 8
};
uint32_t tag;
if (mode == XDR_ENCODE) {
if (vp.isInt32()) {
tag = SCRIPT_INT;
} else if (vp.isDouble()) {
tag = SCRIPT_DOUBLE;
} else if (vp.isString()) {
tag = SCRIPT_ATOM;
} else if (vp.isTrue()) {
tag = SCRIPT_TRUE;
} else if (vp.isFalse()) {
tag = SCRIPT_FALSE;
} else if (vp.isNull()) {
tag = SCRIPT_NULL;
} else if (vp.isObject()) {
tag = SCRIPT_OBJECT;
} else if (vp.isMagic(JS_ELEMENTS_HOLE)) {
tag = SCRIPT_HOLE;
} else {
MOZ_ASSERT(vp.isUndefined());
tag = SCRIPT_VOID;
}
}
if (!xdr->codeUint32(&tag))
return false;
switch (tag) {
case SCRIPT_INT: {
uint32_t i;
if (mode == XDR_ENCODE)
i = uint32_t(vp.toInt32());
if (!xdr->codeUint32(&i))
return false;
if (mode == XDR_DECODE)
vp.set(Int32Value(int32_t(i)));
break;
}
case SCRIPT_DOUBLE: {
double d;
if (mode == XDR_ENCODE)
d = vp.toDouble();
if (!xdr->codeDouble(&d))
return false;
if (mode == XDR_DECODE)
vp.set(DoubleValue(d));
break;
}
case SCRIPT_ATOM: {
RootedAtom atom(cx);
if (mode == XDR_ENCODE)
atom = &vp.toString()->asAtom();
if (!XDRAtom(xdr, &atom))
return false;
if (mode == XDR_DECODE)
vp.set(StringValue(atom));
break;
}
case SCRIPT_TRUE:
if (mode == XDR_DECODE)
vp.set(BooleanValue(true));
break;
case SCRIPT_FALSE:
if (mode == XDR_DECODE)
vp.set(BooleanValue(false));
break;
case SCRIPT_NULL:
if (mode == XDR_DECODE)
vp.set(NullValue());
break;
case SCRIPT_OBJECT: {
RootedObject obj(cx);
if (mode == XDR_ENCODE)
obj = &vp.toObject();
if (!XDRObjectLiteral(xdr, &obj))
return false;
if (mode == XDR_DECODE)
vp.setObject(*obj);
break;
}
case SCRIPT_VOID:
if (mode == XDR_DECODE)
vp.set(UndefinedValue());
break;
case SCRIPT_HOLE:
if (mode == XDR_DECODE)
vp.setMagic(JS_ELEMENTS_HOLE);
break;
}
return true;
}
template bool
js::XDRScriptConst(XDRState<XDR_ENCODE>*, MutableHandleValue);
template bool
js::XDRScriptConst(XDRState<XDR_DECODE>*, MutableHandleValue);
// Code LazyScript's free variables.
template<XDRMode mode>
static bool
XDRLazyFreeVariables(XDRState<mode>* xdr, MutableHandle<LazyScript*> lazy)
{
JSContext* cx = xdr->cx();
RootedAtom atom(cx);
uint8_t isHoistedUse;
LazyScript::FreeVariable* freeVariables = lazy->freeVariables();
size_t numFreeVariables = lazy->numFreeVariables();
for (size_t i = 0; i < numFreeVariables; i++) {
if (mode == XDR_ENCODE) {
atom = freeVariables[i].atom();
isHoistedUse = freeVariables[i].isHoistedUse();
}
if (!XDRAtom(xdr, &atom))
return false;
if (!xdr->codeUint8(&isHoistedUse))
return false;
if (mode == XDR_DECODE) {
freeVariables[i] = LazyScript::FreeVariable(atom);
if (isHoistedUse)
freeVariables[i].setIsHoistedUse();
}
}
return true;
}
// Code the missing part needed to re-create a LazyScript from a JSScript.
template<XDRMode mode>
static bool
XDRRelazificationInfo(XDRState<mode>* xdr, HandleFunction fun, HandleScript script,
HandleObject enclosingScope, MutableHandle<LazyScript*> lazy)
{
MOZ_ASSERT_IF(mode == XDR_ENCODE, script->isRelazifiable() && script->maybeLazyScript());
MOZ_ASSERT_IF(mode == XDR_ENCODE, !lazy->numInnerFunctions());
JSContext* cx = xdr->cx();
uint64_t packedFields;
{
uint32_t begin = script->sourceStart();
uint32_t end = script->sourceEnd();
uint32_t lineno = script->lineno();
uint32_t column = script->column();
if (mode == XDR_ENCODE) {
packedFields = lazy->packedFields();
MOZ_ASSERT(begin == lazy->begin());
MOZ_ASSERT(end == lazy->end());
MOZ_ASSERT(lineno == lazy->lineno());
MOZ_ASSERT(column == lazy->column());
}
if (!xdr->codeUint64(&packedFields))
return false;
if (mode == XDR_DECODE) {
lazy.set(LazyScript::Create(cx, fun, packedFields, begin, end, lineno, column));
// As opposed to XDRLazyScript, we need to restore the runtime bits
// of the script, as we are trying to match the fact this function
// has already been parsed and that it would need to be re-lazified.
lazy->initRuntimeFields(packedFields);
MOZ_ASSERT(!lazy->sourceObject());
lazy->setParent(enclosingScope, &script->scriptSourceUnwrap());
}
}
// Code free variables.
if (!XDRLazyFreeVariables(xdr, lazy))
return false;
return true;
}
static inline uint32_t
FindScopeObjectIndex(JSScript* script, NestedScopeObject& scope)
{
ObjectArray* objects = script->objects();
HeapPtrObject* vector = objects->vector;
unsigned length = objects->length;
for (unsigned i = 0; i < length; ++i) {
if (vector[i] == &scope)
return i;
}
MOZ_CRASH("Scope not found");
}
static bool
SaveSharedScriptData(ExclusiveContext*, Handle<JSScript*>, SharedScriptData*, uint32_t);
enum XDRClassKind {
CK_BlockObject = 0,
CK_WithObject = 1,
CK_JSFunction = 2,
CK_JSObject = 3
};
template<XDRMode mode>
bool
js::XDRScript(XDRState<mode>* xdr, HandleObject enclosingScope, HandleScript enclosingScript,
HandleFunction fun, MutableHandleScript scriptp)
{
/* NB: Keep this in sync with CloneScript. */
enum ScriptBits {
NoScriptRval,
SavedCallerFun,
Strict,
ContainsDynamicNameAccess,
FunHasExtensibleScope,
FunNeedsDeclEnvObject,
FunHasAnyAliasedFormal,
ArgumentsHasVarBinding,
NeedsArgsObj,
IsGeneratorExp,
IsLegacyGenerator,
IsStarGenerator,
OwnSource,
ExplicitUseStrict,
SelfHosted,
IsCompileAndGo,
HasSingleton,
TreatAsRunOnce,
HasLazyScript,
HasPollutedGlobalScope,
};
uint32_t length, lineno, column, nslots, staticLevel;
uint32_t natoms, nsrcnotes, i;
uint32_t nconsts, nobjects, nregexps, ntrynotes, nblockscopes, nyieldoffsets;
uint32_t prologLength, version;
uint32_t funLength = 0;
uint32_t nTypeSets = 0;
uint32_t scriptBits = 0;
JSContext* cx = xdr->cx();
RootedScript script(cx);
natoms = nsrcnotes = 0;
nconsts = nobjects = nregexps = ntrynotes = nblockscopes = nyieldoffsets = 0;
/* XDR arguments and vars. */
uint16_t nargs = 0;
uint16_t nblocklocals = 0;
uint16_t nbodylevellexicals = 0;
uint32_t nvars = 0;
uint32_t nunaliasedvars = 0;
uint16_t nunaliasedbodylevellexicals = 0;
if (mode == XDR_ENCODE) {
script = scriptp.get();
MOZ_ASSERT_IF(enclosingScript, enclosingScript->compartment() == script->compartment());
nargs = script->bindings.numArgs();
nblocklocals = script->bindings.numBlockScoped();
nbodylevellexicals = script->bindings.numBodyLevelLexicals();
nvars = script->bindings.numVars();
nunaliasedvars = script->bindings.numUnaliasedVars();
nunaliasedbodylevellexicals = script->bindings.numUnaliasedBodyLevelLexicals();
}
if (!xdr->codeUint16(&nargs))
return false;
if (!xdr->codeUint16(&nblocklocals))
return false;
if (!xdr->codeUint16(&nbodylevellexicals))
return false;
if (!xdr->codeUint32(&nvars))
return false;
if (!xdr->codeUint32(&nunaliasedvars))
return false;
if (!xdr->codeUint16(&nunaliasedbodylevellexicals))
return false;
if (mode == XDR_ENCODE)
length = script->length();
if (!xdr->codeUint32(&length))
return false;
if (mode == XDR_ENCODE) {
prologLength = script->mainOffset();
MOZ_ASSERT(script->getVersion() != JSVERSION_UNKNOWN);
version = script->getVersion();
lineno = script->lineno();
column = script->column();
nslots = script->nslots();
staticLevel = script->staticLevel();
natoms = script->natoms();
nsrcnotes = script->numNotes();
if (script->hasConsts())
nconsts = script->consts()->length;
if (script->hasObjects())
nobjects = script->objects()->length;
if (script->hasRegexps())
nregexps = script->regexps()->length;
if (script->hasTrynotes())
ntrynotes = script->trynotes()->length;
if (script->hasBlockScopes())
nblockscopes = script->blockScopes()->length;
if (script->hasYieldOffsets())
nyieldoffsets = script->yieldOffsets().length();
nTypeSets = script->nTypeSets();
funLength = script->funLength();
if (script->noScriptRval())
scriptBits |= (1 << NoScriptRval);
if (script->savedCallerFun())
scriptBits |= (1 << SavedCallerFun);
if (script->strict())
scriptBits |= (1 << Strict);
if (script->explicitUseStrict())
scriptBits |= (1 << ExplicitUseStrict);
if (script->selfHosted())
scriptBits |= (1 << SelfHosted);
if (script->bindingsAccessedDynamically())
scriptBits |= (1 << ContainsDynamicNameAccess);
if (script->funHasExtensibleScope())
scriptBits |= (1 << FunHasExtensibleScope);
if (script->funNeedsDeclEnvObject())
scriptBits |= (1 << FunNeedsDeclEnvObject);
if (script->funHasAnyAliasedFormal())
scriptBits |= (1 << FunHasAnyAliasedFormal);
if (script->argumentsHasVarBinding())
scriptBits |= (1 << ArgumentsHasVarBinding);
if (script->analyzedArgsUsage() && script->needsArgsObj())
scriptBits |= (1 << NeedsArgsObj);
if (!enclosingScript || enclosingScript->scriptSource() != script->scriptSource())
scriptBits |= (1 << OwnSource);
if (script->isGeneratorExp())
scriptBits |= (1 << IsGeneratorExp);
if (script->isLegacyGenerator())
scriptBits |= (1 << IsLegacyGenerator);
if (script->isStarGenerator())
scriptBits |= (1 << IsStarGenerator);
if (script->compileAndGo())
scriptBits |= (1 << IsCompileAndGo);
if (script->hasSingletons())
scriptBits |= (1 << HasSingleton);
if (script->treatAsRunOnce())
scriptBits |= (1 << TreatAsRunOnce);
if (script->isRelazifiable())
scriptBits |= (1 << HasLazyScript);
if (script->hasPollutedGlobalScope())
scriptBits |= (1 << HasPollutedGlobalScope);
}
if (!xdr->codeUint32(&prologLength))
return false;
if (!xdr->codeUint32(&version))
return false;
// To fuse allocations, we need lengths of all embedded arrays early.
if (!xdr->codeUint32(&natoms))
return false;
if (!xdr->codeUint32(&nsrcnotes))
return false;
if (!xdr->codeUint32(&nconsts))
return false;
if (!xdr->codeUint32(&nobjects))
return false;
if (!xdr->codeUint32(&nregexps))
return false;
if (!xdr->codeUint32(&ntrynotes))
return false;
if (!xdr->codeUint32(&nblockscopes))
return false;
if (!xdr->codeUint32(&nyieldoffsets))
return false;
if (!xdr->codeUint32(&nTypeSets))
return false;
if (!xdr->codeUint32(&funLength))
return false;
if (!xdr->codeUint32(&scriptBits))
return false;
if (mode == XDR_DECODE) {
JSVersion version_ = JSVersion(version);
MOZ_ASSERT((version_ & VersionFlags::MASK) == unsigned(version_));
// staticLevel is set below.
CompileOptions options(cx);
options.setVersion(version_)
.setNoScriptRval(!!(scriptBits & (1 << NoScriptRval)))
.setSelfHostingMode(!!(scriptBits & (1 << SelfHosted)));
RootedScriptSource sourceObject(cx);
if (scriptBits & (1 << OwnSource)) {
ScriptSource* ss = cx->new_<ScriptSource>();
if (!ss)
return false;
ScriptSourceHolder ssHolder(ss);
/*
* We use this CompileOptions only to initialize the
* ScriptSourceObject. Most CompileOptions fields aren't used by
* ScriptSourceObject, and those that are (element; elementAttributeName)
* aren't preserved by XDR. So this can be simple.
*/
CompileOptions options(cx);
ss->initFromOptions(cx, options);
sourceObject = ScriptSourceObject::create(cx, ss);
if (!sourceObject ||
!ScriptSourceObject::initFromOptions(cx, sourceObject, options))
return false;
} else {
MOZ_ASSERT(enclosingScript);
// When decoding, all the scripts and the script source object
// are in the same compartment, so the script's source object
// should never be a cross-compartment wrapper.
MOZ_ASSERT(enclosingScript->sourceObject()->is<ScriptSourceObject>());
sourceObject = &enclosingScript->sourceObject()->as<ScriptSourceObject>();
}
script = JSScript::Create(cx, enclosingScope, !!(scriptBits & (1 << SavedCallerFun)),
options, /* staticLevel = */ 0, sourceObject, 0, 0);
if (!script)
return false;
}
/* JSScript::partiallyInit assumes script->bindings is fully initialized. */
LifoAllocScope las(&cx->tempLifoAlloc());
if (!XDRScriptBindings(xdr, las, nargs, nvars, nbodylevellexicals, nblocklocals,
nunaliasedvars, nunaliasedbodylevellexicals, script))
return false;
if (mode == XDR_DECODE) {
if (!JSScript::partiallyInit(cx, script, nconsts, nobjects, nregexps, ntrynotes,
nblockscopes, nyieldoffsets, nTypeSets))
{
return false;
}
MOZ_ASSERT(!script->mainOffset());
script->mainOffset_ = prologLength;
script->setLength(length);
script->funLength_ = funLength;
scriptp.set(script);
if (scriptBits & (1 << Strict))
script->strict_ = true;
if (scriptBits & (1 << ExplicitUseStrict))
script->explicitUseStrict_ = true;
if (scriptBits & (1 << ContainsDynamicNameAccess))
script->bindingsAccessedDynamically_ = true;
if (scriptBits & (1 << FunHasExtensibleScope))
script->funHasExtensibleScope_ = true;
if (scriptBits & (1 << FunNeedsDeclEnvObject))
script->funNeedsDeclEnvObject_ = true;
if (scriptBits & (1 << FunHasAnyAliasedFormal))
script->funHasAnyAliasedFormal_ = true;
if (scriptBits & (1 << ArgumentsHasVarBinding))
script->setArgumentsHasVarBinding();
if (scriptBits & (1 << NeedsArgsObj))
script->setNeedsArgsObj(true);
if (scriptBits & (1 << IsGeneratorExp))
script->isGeneratorExp_ = true;
if (scriptBits & (1 << IsCompileAndGo))
script->compileAndGo_ = true;
if (scriptBits & (1 << HasSingleton))
script->hasSingletons_ = true;
if (scriptBits & (1 << TreatAsRunOnce))
script->treatAsRunOnce_ = true;
if (scriptBits & (1 << HasPollutedGlobalScope))
script->hasPollutedGlobalScope_ = true;
if (scriptBits & (1 << IsLegacyGenerator)) {
MOZ_ASSERT(!(scriptBits & (1 << IsStarGenerator)));
script->setGeneratorKind(LegacyGenerator);
} else if (scriptBits & (1 << IsStarGenerator))
script->setGeneratorKind(StarGenerator);
}
JS_STATIC_ASSERT(sizeof(jsbytecode) == 1);
JS_STATIC_ASSERT(sizeof(jssrcnote) == 1);
if (scriptBits & (1 << OwnSource)) {
if (!script->scriptSource()->performXDR<mode>(xdr))
return false;
}
if (!xdr->codeUint32(&script->sourceStart_))
return false;
if (!xdr->codeUint32(&script->sourceEnd_))
return false;
if (!xdr->codeUint32(&lineno) ||
!xdr->codeUint32(&column) ||
!xdr->codeUint32(&nslots) ||
!xdr->codeUint32(&staticLevel))
{
return false;
}
if (mode == XDR_DECODE) {
script->lineno_ = lineno;
script->column_ = column;
script->nslots_ = nslots;
script->staticLevel_ = staticLevel;
}
jsbytecode* code = script->code();
SharedScriptData* ssd;
if (mode == XDR_DECODE) {
ssd = SharedScriptData::new_(cx, length, nsrcnotes, natoms);
if (!ssd)
return false;
code = ssd->data;
if (natoms != 0) {
script->natoms_ = natoms;
script->atoms = ssd->atoms();
}
}
if (!xdr->codeBytes(code, length) || !xdr->codeBytes(code + length, nsrcnotes)) {
if (mode == XDR_DECODE)
js_free(ssd);
return false;
}
for (i = 0; i != natoms; ++i) {
if (mode == XDR_DECODE) {
RootedAtom tmp(cx);
if (!XDRAtom(xdr, &tmp))
return false;
script->atoms[i].init(tmp);
} else {
RootedAtom tmp(cx, script->atoms[i]);
if (!XDRAtom(xdr, &tmp))
return false;
}
}
if (mode == XDR_DECODE) {
if (!SaveSharedScriptData(cx, script, ssd, nsrcnotes))
return false;
}
if (nconsts) {
HeapValue* vector = script->consts()->vector;
RootedValue val(cx);
for (i = 0; i != nconsts; ++i) {
if (mode == XDR_ENCODE)
val = vector[i];
if (!XDRScriptConst(xdr, &val))
return false;
if (mode == XDR_DECODE)
vector[i].init(val);
}
}
/*
* Here looping from 0-to-length to xdr objects is essential to ensure that
* all references to enclosing blocks (via FindScopeObjectIndex below) happen
* after the enclosing block has been XDR'd.
*/
for (i = 0; i != nobjects; ++i) {
HeapPtrObject* objp = &script->objects()->vector[i];
XDRClassKind classk;
if (mode == XDR_ENCODE) {
JSObject* obj = *objp;
if (obj->is<BlockObject>())
classk = CK_BlockObject;
else if (obj->is<StaticWithObject>())
classk = CK_WithObject;
else if (obj->is<JSFunction>())
classk = CK_JSFunction;
else if (obj->is<PlainObject>() || obj->is<ArrayObject>())
classk = CK_JSObject;
else
MOZ_CRASH("Cannot encode this class of object.");
}
if (!xdr->codeEnum32(&classk))
return false;
switch (classk) {
case CK_BlockObject:
case CK_WithObject: {
/* Code the nested block's enclosing scope. */
uint32_t enclosingStaticScopeIndex = 0;
if (mode == XDR_ENCODE) {
NestedScopeObject& scope = (*objp)->as<NestedScopeObject>();
if (NestedScopeObject* enclosing = scope.enclosingNestedScope())
enclosingStaticScopeIndex = FindScopeObjectIndex(script, *enclosing);
else
enclosingStaticScopeIndex = UINT32_MAX;
}
if (!xdr->codeUint32(&enclosingStaticScopeIndex))
return false;
Rooted<JSObject*> enclosingStaticScope(cx);
if (mode == XDR_DECODE) {
if (enclosingStaticScopeIndex != UINT32_MAX) {
MOZ_ASSERT(enclosingStaticScopeIndex < i);
enclosingStaticScope = script->objects()->vector[enclosingStaticScopeIndex];
} else {
enclosingStaticScope = fun;
}
}
if (classk == CK_BlockObject) {
Rooted<StaticBlockObject*> tmp(cx, static_cast<StaticBlockObject*>(objp->get()));
if (!XDRStaticBlockObject(xdr, enclosingStaticScope, &tmp))
return false;
*objp = tmp;
} else {
Rooted<StaticWithObject*> tmp(cx, static_cast<StaticWithObject*>(objp->get()));
if (!XDRStaticWithObject(xdr, enclosingStaticScope, &tmp))
return false;
*objp = tmp;
}
break;
}
case CK_JSFunction: {
/* Code the nested function's enclosing scope. */
uint32_t funEnclosingScopeIndex = 0;
RootedObject funEnclosingScope(cx);
if (mode == XDR_ENCODE) {
RootedFunction function(cx, &(*objp)->as<JSFunction>());
if (function->isInterpretedLazy())
funEnclosingScope = function->lazyScript()->enclosingScope();
else if (function->isInterpreted())
funEnclosingScope = function->nonLazyScript()->enclosingStaticScope();
else {
MOZ_ASSERT(function->isAsmJSNative());
JS_ReportError(cx, "AsmJS modules are not yet supported in XDR serialization.");
return false;
}
StaticScopeIter<NoGC> ssi(funEnclosingScope);
if (ssi.done() || ssi.type() == StaticScopeIter<NoGC>::Function) {
MOZ_ASSERT(ssi.done() == !fun);
funEnclosingScopeIndex = UINT32_MAX;
} else if (ssi.type() == StaticScopeIter<NoGC>::Block) {
funEnclosingScopeIndex = FindScopeObjectIndex(script, ssi.block());
MOZ_ASSERT(funEnclosingScopeIndex < i);
} else {
funEnclosingScopeIndex = FindScopeObjectIndex(script, ssi.staticWith());
MOZ_ASSERT(funEnclosingScopeIndex < i);
}
}
if (!xdr->codeUint32(&funEnclosingScopeIndex))
return false;
if (mode == XDR_DECODE) {
if (funEnclosingScopeIndex == UINT32_MAX) {
funEnclosingScope = fun;
} else {
MOZ_ASSERT(funEnclosingScopeIndex < i);
funEnclosingScope = script->objects()->vector[funEnclosingScopeIndex];
}
}
// Code nested function and script.
RootedFunction tmp(cx);
if (mode == XDR_ENCODE)
tmp = &(*objp)->as<JSFunction>();
if (!XDRInterpretedFunction(xdr, funEnclosingScope, script, &tmp))
return false;
*objp = tmp;
break;
}
case CK_JSObject: {
/* Code object literal. */
RootedObject tmp(cx, *objp);
if (!XDRObjectLiteral(xdr, &tmp))
return false;
*objp = tmp;
break;
}
default: {
MOZ_ASSERT(false, "Unknown class kind.");
return false;
}
}
}
for (i = 0; i != nregexps; ++i) {
Rooted<RegExpObject*> regexp(cx);
if (mode == XDR_ENCODE)
regexp = &script->regexps()->vector[i]->as<RegExpObject>();
if (!XDRScriptRegExpObject(xdr, ®exp))
return false;
if (mode == XDR_DECODE)
script->regexps()->vector[i] = regexp;
}
if (ntrynotes != 0) {
JSTryNote* tnfirst = script->trynotes()->vector;
MOZ_ASSERT(script->trynotes()->length == ntrynotes);
JSTryNote* tn = tnfirst + ntrynotes;
do {
--tn;
if (!xdr->codeUint8(&tn->kind) ||
!xdr->codeUint32(&tn->stackDepth) ||
!xdr->codeUint32(&tn->start) ||
!xdr->codeUint32(&tn->length)) {
return false;
}
} while (tn != tnfirst);
}
for (i = 0; i < nblockscopes; ++i) {
BlockScopeNote* note = &script->blockScopes()->vector[i];
if (!xdr->codeUint32(¬e->index) ||
!xdr->codeUint32(¬e->start) ||
!xdr->codeUint32(¬e->length) ||
!xdr->codeUint32(¬e->parent))
{
return false;
}
}
for (i = 0; i < nyieldoffsets; ++i) {
uint32_t* offset = &script->yieldOffsets()[i];
if (!xdr->codeUint32(offset))
return false;
}
if (scriptBits & (1 << HasLazyScript)) {
Rooted<LazyScript*> lazy(cx);
if (mode == XDR_ENCODE)
lazy = script->maybeLazyScript();
if (!XDRRelazificationInfo(xdr, fun, script, enclosingScope, &lazy))
return false;
if (mode == XDR_DECODE)
script->setLazyScript(lazy);
}
if (mode == XDR_DECODE) {
scriptp.set(script);
/* see BytecodeEmitter::tellDebuggerAboutCompiledScript */
if (!fun)
Debugger::onNewScript(cx, script);
}
return true;
}
template bool
js::XDRScript(XDRState<XDR_ENCODE>*, HandleObject, HandleScript, HandleFunction,
MutableHandleScript);
template bool
js::XDRScript(XDRState<XDR_DECODE>*, HandleObject, HandleScript, HandleFunction,
MutableHandleScript);
template<XDRMode mode>
bool
js::XDRLazyScript(XDRState<mode>* xdr, HandleObject enclosingScope, HandleScript enclosingScript,
HandleFunction fun, MutableHandle<LazyScript*> lazy)
{
JSContext* cx = xdr->cx();
{
uint32_t begin;
uint32_t end;
uint32_t lineno;
uint32_t column;
uint64_t packedFields;
if (mode == XDR_ENCODE) {
MOZ_ASSERT(!lazy->maybeScript());
MOZ_ASSERT(fun == lazy->functionNonDelazifying());
begin = lazy->begin();
end = lazy->end();
lineno = lazy->lineno();
column = lazy->column();
packedFields = lazy->packedFields();
}
if (!xdr->codeUint32(&begin) || !xdr->codeUint32(&end) ||
!xdr->codeUint32(&lineno) || !xdr->codeUint32(&column) ||
!xdr->codeUint64(&packedFields))
{
return false;
}
if (mode == XDR_DECODE)
lazy.set(LazyScript::Create(cx, fun, packedFields, begin, end, lineno, column));
}
// Code free variables.
if (!XDRLazyFreeVariables(xdr, lazy))
return false;
// Code inner functions.
{
RootedFunction func(cx);
HeapPtrFunction* innerFunctions = lazy->innerFunctions();
size_t numInnerFunctions = lazy->numInnerFunctions();
for (size_t i = 0; i < numInnerFunctions; i++) {
if (mode == XDR_ENCODE)
func = innerFunctions[i];
if (!XDRInterpretedFunction(xdr, fun, enclosingScript, &func))
return false;
if (mode == XDR_DECODE)
innerFunctions[i] = func;
}
}
if (mode == XDR_DECODE) {
MOZ_ASSERT(!lazy->sourceObject());
ScriptSourceObject* sourceObject = &enclosingScript->scriptSourceUnwrap();
// Set the enclosing scope of the lazy function, this would later be
// used to define the environment when the function would be used.
lazy->setParent(enclosingScope, sourceObject);
}
return true;
}
template bool
js::XDRLazyScript(XDRState<XDR_ENCODE>*, HandleObject, HandleScript,
HandleFunction, MutableHandle<LazyScript*>);
template bool
js::XDRLazyScript(XDRState<XDR_DECODE>*, HandleObject, HandleScript,
HandleFunction, MutableHandle<LazyScript*>);
void
JSScript::setSourceObject(JSObject* object)
{
MOZ_ASSERT(compartment() == object->compartment());
sourceObject_ = object;
}
js::ScriptSourceObject&
JSScript::scriptSourceUnwrap() const {
return UncheckedUnwrap(sourceObject())->as<ScriptSourceObject>();
}
js::ScriptSource*
JSScript::scriptSource() const {
return scriptSourceUnwrap().source();
}
js::ScriptSource*
JSScript::maybeForwardedScriptSource() const {
return UncheckedUnwrap(MaybeForwarded(sourceObject()))->as<ScriptSourceObject>().source();
}
bool
JSScript::initScriptCounts(JSContext* cx)
{
MOZ_ASSERT(!hasScriptCounts());
size_t n = 0;
for (jsbytecode* pc = code(); pc < codeEnd(); pc += GetBytecodeLength(pc))
n += PCCounts::numCounts(JSOp(*pc));
size_t nbytes = (length() * sizeof(PCCounts)) + (n * sizeof(double));
uint8_t* base = zone()->pod_calloc<uint8_t>(nbytes);
if (!base)
return false;
/* Create compartment's scriptCountsMap if necessary. */
ScriptCountsMap* map = compartment()->scriptCountsMap;
if (!map) {
map = cx->new_<ScriptCountsMap>();
if (!map || !map->init()) {
js_free(base);
js_delete(map);
return false;
}
compartment()->scriptCountsMap = map;
}
uint8_t* cursor = base;
ScriptCounts scriptCounts;
scriptCounts.pcCountsVector = (PCCounts*) cursor;
cursor += length() * sizeof(PCCounts);
for (jsbytecode* pc = code(); pc < codeEnd(); pc += GetBytecodeLength(pc)) {
MOZ_ASSERT(uintptr_t(cursor) % sizeof(double) == 0);
scriptCounts.pcCountsVector[pcToOffset(pc)].counts = (double*) cursor;
size_t capacity = PCCounts::numCounts(JSOp(*pc));
#ifdef DEBUG
scriptCounts.pcCountsVector[pcToOffset(pc)].capacity = capacity;
#endif
cursor += capacity * sizeof(double);
}
if (!map->putNew(this, scriptCounts)) {
js_free(base);
return false;
}
hasScriptCounts_ = true; // safe to set this; we can't fail after this point
MOZ_ASSERT(size_t(cursor - base) == nbytes);
/* Enable interrupts in any interpreter frames running on this script. */
for (ActivationIterator iter(cx->runtime()); !iter.done(); ++iter) {
if (iter->isInterpreter())
iter->asInterpreter()->enableInterruptsIfRunning(this);
}
return true;
}
static inline ScriptCountsMap::Ptr GetScriptCountsMapEntry(JSScript* script)
{
MOZ_ASSERT(script->hasScriptCounts());
ScriptCountsMap* map = script->compartment()->scriptCountsMap;
ScriptCountsMap::Ptr p = map->lookup(script);
MOZ_ASSERT(p);
return p;
}
js::PCCounts
JSScript::getPCCounts(jsbytecode* pc) {
MOZ_ASSERT(containsPC(pc));
ScriptCountsMap::Ptr p = GetScriptCountsMapEntry(this);
return p->value().pcCountsVector[pcToOffset(pc)];
}
void
JSScript::addIonCounts(jit::IonScriptCounts* ionCounts)
{
ScriptCountsMap::Ptr p = GetScriptCountsMapEntry(this);
if (p->value().ionCounts)
ionCounts->setPrevious(p->value().ionCounts);
p->value().ionCounts = ionCounts;
}
jit::IonScriptCounts*
JSScript::getIonCounts()
{
ScriptCountsMap::Ptr p = GetScriptCountsMapEntry(this);
return p->value().ionCounts;
}
ScriptCounts
JSScript::releaseScriptCounts()
{
ScriptCountsMap::Ptr p = GetScriptCountsMapEntry(this);
ScriptCounts counts = p->value();
compartment()->scriptCountsMap->remove(p);
hasScriptCounts_ = false;
return counts;
}
void
JSScript::destroyScriptCounts(FreeOp* fop)
{
if (hasScriptCounts()) {
ScriptCounts scriptCounts = releaseScriptCounts();
scriptCounts.destroy(fop);
}
}
void
ScriptSourceObject::trace(JSTracer* trc, JSObject* obj)
{
ScriptSourceObject* sso = static_cast<ScriptSourceObject*>(obj);
// Don't trip over the poison 'not yet initialized' values.
if (!sso->getReservedSlot(INTRODUCTION_SCRIPT_SLOT).isMagic(JS_GENERIC_MAGIC)) {
JSScript* script = sso->introductionScript();
if (script) {
MarkScriptUnbarriered(trc, &script, "ScriptSourceObject introductionScript");
sso->setReservedSlot(INTRODUCTION_SCRIPT_SLOT, PrivateValue(script));
}
}
}
void
ScriptSourceObject::finalize(FreeOp* fop, JSObject* obj)
{
ScriptSourceObject* sso = &obj->as<ScriptSourceObject>();
sso->source()->decref();
sso->setReservedSlot(SOURCE_SLOT, PrivateValue(nullptr));
}
const Class ScriptSourceObject::class_ = {
"ScriptSource",
JSCLASS_HAS_RESERVED_SLOTS(RESERVED_SLOTS) |
JSCLASS_IMPLEMENTS_BARRIERS | JSCLASS_IS_ANONYMOUS,
nullptr, /* addProperty */
nullptr, /* delProperty */
nullptr, /* getProperty */
nullptr, /* setProperty */
nullptr, /* enumerate */
nullptr, /* resolve */
nullptr, /* convert */
finalize,
nullptr, /* call */
nullptr, /* hasInstance */
nullptr, /* construct */
trace
};
ScriptSourceObject*
ScriptSourceObject::create(ExclusiveContext* cx, ScriptSource* source)
{
RootedObject object(cx, NewObjectWithGivenProto(cx, &class_, NullPtr()));
if (!object)
return nullptr;
RootedScriptSource sourceObject(cx, &object->as<ScriptSourceObject>());
source->incref(); // The matching decref is in ScriptSourceObject::finalize.
sourceObject->initReservedSlot(SOURCE_SLOT, PrivateValue(source));
// The remaining slots should eventually be populated by a call to
// initFromOptions. Poison them until that point.
sourceObject->initReservedSlot(ELEMENT_SLOT, MagicValue(JS_GENERIC_MAGIC));
sourceObject->initReservedSlot(ELEMENT_PROPERTY_SLOT, MagicValue(JS_GENERIC_MAGIC));
sourceObject->initReservedSlot(INTRODUCTION_SCRIPT_SLOT, MagicValue(JS_GENERIC_MAGIC));
return sourceObject;
}
/* static */ bool
ScriptSourceObject::initFromOptions(JSContext* cx, HandleScriptSource source,
const ReadOnlyCompileOptions& options)
{
assertSameCompartment(cx, source);
MOZ_ASSERT(source->getReservedSlot(ELEMENT_SLOT).isMagic(JS_GENERIC_MAGIC));
MOZ_ASSERT(source->getReservedSlot(ELEMENT_PROPERTY_SLOT).isMagic(JS_GENERIC_MAGIC));
MOZ_ASSERT(source->getReservedSlot(INTRODUCTION_SCRIPT_SLOT).isMagic(JS_GENERIC_MAGIC));
RootedValue element(cx, ObjectOrNullValue(options.element()));
if (!cx->compartment()->wrap(cx, &element))
return false;
source->setReservedSlot(ELEMENT_SLOT, element);
RootedValue elementAttributeName(cx);
if (options.elementAttributeName())
elementAttributeName = StringValue(options.elementAttributeName());
else
elementAttributeName = UndefinedValue();
if (!cx->compartment()->wrap(cx, &elementAttributeName))
return false;
source->setReservedSlot(ELEMENT_PROPERTY_SLOT, elementAttributeName);
// There is no equivalent of cross-compartment wrappers for scripts. If the
// introduction script and ScriptSourceObject are in different compartments,
// we would be creating a cross-compartment script reference, which is
// forbidden. In that case, simply don't bother to retain the introduction
// script.
if (options.introductionScript() &&
options.introductionScript()->compartment() == cx->compartment())
{
source->setReservedSlot(INTRODUCTION_SCRIPT_SLOT, PrivateValue(options.introductionScript()));
} else {
source->setReservedSlot(INTRODUCTION_SCRIPT_SLOT, UndefinedValue());
}
return true;
}
/* static */ bool
JSScript::loadSource(JSContext* cx, ScriptSource* ss, bool* worked)
{
MOZ_ASSERT(!ss->hasSourceData());
*worked = false;
if (!cx->runtime()->sourceHook || !ss->sourceRetrievable())
return true;
char16_t* src = nullptr;
size_t length;
if (!cx->runtime()->sourceHook->load(cx, ss->filename(), &src, &length))
return false;
if (!src)
return true;
ss->setSource(src, length);
*worked = true;
return true;
}
JSFlatString*
JSScript::sourceData(JSContext* cx)
{
MOZ_ASSERT(scriptSource()->hasSourceData());
return scriptSource()->substring(cx, sourceStart(), sourceEnd());
}
UncompressedSourceCache::AutoHoldEntry::AutoHoldEntry()
: cache_(nullptr), source_(nullptr), charsToFree_(nullptr)
{
}
void
UncompressedSourceCache::AutoHoldEntry::holdEntry(UncompressedSourceCache* cache, ScriptSource* source)
{
// Initialise the holder for a specific cache and script source. This will
// hold on to the cached source chars in the event that the cache is purged.
MOZ_ASSERT(!cache_ && !source_ && !charsToFree_);
cache_ = cache;
source_ = source;
}
void
UncompressedSourceCache::AutoHoldEntry::deferDelete(const char16_t* chars)
{
// Take ownership of source chars now the cache is being purged. Remove our
// reference to the ScriptSource which might soon be destroyed.
MOZ_ASSERT(cache_ && source_ && !charsToFree_);
cache_ = nullptr;
source_ = nullptr;
charsToFree_ = chars;
}
UncompressedSourceCache::AutoHoldEntry::~AutoHoldEntry()
{
// The holder is going out of scope. If it has taken ownership of cached
// chars then delete them, otherwise unregister ourself with the cache.
if (charsToFree_) {
MOZ_ASSERT(!cache_ && !source_);
js_free(const_cast<char16_t*>(charsToFree_));
} else if (cache_) {
MOZ_ASSERT(source_);
cache_->releaseEntry(*this);
}
}
void
UncompressedSourceCache::holdEntry(AutoHoldEntry& holder, ScriptSource* ss)
{
MOZ_ASSERT(!holder_);
holder.holdEntry(this, ss);
holder_ = &holder;
}
void
UncompressedSourceCache::releaseEntry(AutoHoldEntry& holder)
{
MOZ_ASSERT(holder_ == &holder);
holder_ = nullptr;
}
const char16_t*
UncompressedSourceCache::lookup(ScriptSource* ss, AutoHoldEntry& holder)
{
MOZ_ASSERT(!holder_);
if (!map_)
return nullptr;
if (Map::Ptr p = map_->lookup(ss)) {
holdEntry(holder, ss);
return p->value();
}
return nullptr;
}
bool
UncompressedSourceCache::put(ScriptSource* ss, const char16_t* str, AutoHoldEntry& holder)
{
MOZ_ASSERT(!holder_);
if (!map_) {
map_ = js_new<Map>();
if (!map_)
return false;
if (!map_->init()) {
js_delete(map_);
map_ = nullptr;
return false;
}
}
if (!map_->put(ss, str))
return false;
holdEntry(holder, ss);
return true;
}
void
UncompressedSourceCache::purge()
{
if (!map_)
return;
for (Map::Range r = map_->all(); !r.empty(); r.popFront()) {
const char16_t* chars = r.front().value();
if (holder_ && r.front().key() == holder_->source()) {
holder_->deferDelete(chars);
holder_ = nullptr;
} else {
js_free(const_cast<char16_t*>(chars));
}
}
js_delete(map_);
map_ = nullptr;
}
size_t
UncompressedSourceCache::sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf)
{
size_t n = 0;
if (map_ && !map_->empty()) {
n += map_->sizeOfIncludingThis(mallocSizeOf);
for (Map::Range r = map_->all(); !r.empty(); r.popFront()) {
const char16_t* v = r.front().value();
n += mallocSizeOf(v);
}
}
return n;
}
const char16_t*
ScriptSource::chars(JSContext* cx, UncompressedSourceCache::AutoHoldEntry& holder)
{
switch (dataType) {
case DataUncompressed:
return uncompressedChars();
case DataCompressed: {
if (const char16_t* decompressed = cx->runtime()->uncompressedSourceCache.lookup(this, holder))
return decompressed;
const size_t nbytes = sizeof(char16_t) * (length_ + 1);
char16_t* decompressed = static_cast<char16_t*>(js_malloc(nbytes));
if (!decompressed)
return nullptr;
if (!DecompressString((const unsigned char*) compressedData(), compressedBytes(),
reinterpret_cast<unsigned char*>(decompressed), nbytes)) {
JS_ReportOutOfMemory(cx);
js_free(decompressed);
return nullptr;
}
decompressed[length_] = 0;
if (!cx->runtime()->uncompressedSourceCache.put(this, decompressed, holder)) {
JS_ReportOutOfMemory(cx);
js_free(decompressed);
return nullptr;
}
return decompressed;
}
case DataParent:
return parent()->chars(cx, holder);
default:
MOZ_CRASH();
}
}
JSFlatString*
ScriptSource::substring(JSContext* cx, uint32_t start, uint32_t stop)
{
MOZ_ASSERT(start <= stop);
UncompressedSourceCache::AutoHoldEntry holder;
const char16_t* chars = this->chars(cx, holder);
if (!chars)
return nullptr;
return NewStringCopyN<CanGC>(cx, chars + start, stop - start);
}
JSFlatString*
ScriptSource::substringDontDeflate(JSContext* cx, uint32_t start, uint32_t stop)
{
MOZ_ASSERT(start <= stop);
UncompressedSourceCache::AutoHoldEntry holder;
const char16_t* chars = this->chars(cx, holder);
if (!chars)
return nullptr;
return NewStringCopyNDontDeflate<CanGC>(cx, chars + start, stop - start);
}
void
ScriptSource::setSource(const char16_t* chars, size_t length, bool ownsChars /* = true */)
{
MOZ_ASSERT(dataType == DataMissing);
dataType = DataUncompressed;
data.uncompressed.chars = chars;
data.uncompressed.ownsChars = ownsChars;
length_ = length;
}
void
ScriptSource::setCompressedSource(JSRuntime* maybert, void* raw, size_t nbytes, HashNumber hash)
{
MOZ_ASSERT(dataType == DataMissing || dataType == DataUncompressed);
if (dataType == DataUncompressed && ownsUncompressedChars())
js_free(const_cast<char16_t*>(uncompressedChars()));
dataType = DataCompressed;
data.compressed.raw = raw;
data.compressed.nbytes = nbytes;
data.compressed.hash = hash;
if (maybert)
updateCompressedSourceSet(maybert);
}
void
ScriptSource::updateCompressedSourceSet(JSRuntime* rt)
{
MOZ_ASSERT(dataType == DataCompressed);
MOZ_ASSERT(!inCompressedSourceSet);
CompressedSourceSet::AddPtr p = rt->compressedSourceSet.lookupForAdd(this);
if (p) {
// There is another ScriptSource with the same compressed data.
// Mark that ScriptSource as the parent and use it for all attempts to
// get the source for this ScriptSource.
ScriptSource* parent = *p;
parent->incref();
js_free(compressedData());
dataType = DataParent;
data.parent = parent;
} else {
if (rt->compressedSourceSet.add(p, this))
inCompressedSourceSet = true;
}
}
bool
ScriptSource::ensureOwnsSource(ExclusiveContext* cx)
{
MOZ_ASSERT(dataType == DataUncompressed);
if (ownsUncompressedChars())
return true;
char16_t* uncompressed = cx->zone()->pod_malloc<char16_t>(Max<size_t>(length_, 1));
if (!uncompressed)
return false;
PodCopy(uncompressed, uncompressedChars(), length_);
data.uncompressed.chars = uncompressed;
data.uncompressed.ownsChars = true;
return true;
}
bool
ScriptSource::setSourceCopy(ExclusiveContext* cx, SourceBufferHolder& srcBuf,
bool argumentsNotIncluded, SourceCompressionTask* task)
{
MOZ_ASSERT(!hasSourceData());
argumentsNotIncluded_ = argumentsNotIncluded;
bool owns = srcBuf.ownsChars();
setSource(owns ? srcBuf.take() : srcBuf.get(), srcBuf.length(), owns);
// There are several cases where source compression is not a good idea:
// - If the script is tiny, then compression will save little or no space.
// - If the script is enormous, then decompression can take seconds. With
// lazy parsing, decompression is not uncommon, so this can significantly
// increase latency.
// - If there is only one core, then compression will contend with JS
// execution (which hurts benchmarketing).
// - If the source contains a giant string, then parsing will finish much
// faster than compression which increases latency (this case is handled
// in Parser::stringLiteral).
//
// Lastly, since the parsing thread will eventually perform a blocking wait
// on the compression task's thread, require that there are at least 2
// helper threads:
// - If we are on a helper thread, there must be another helper thread to
// execute our compression task.
// - If we are on the main thread, there must be at least two helper
// threads since at most one helper thread can be blocking on the main
// thread (see HelperThreadState::canStartParseTask) which would cause a
// deadlock if there wasn't a second helper thread that could make
// progress on our compression task.
bool canCompressOffThread =
HelperThreadState().cpuCount > 1 &&
HelperThreadState().threadCount >= 2 &&
CanUseExtraThreads();
const size_t TINY_SCRIPT = 256;
const size_t HUGE_SCRIPT = 5 * 1024 * 1024;
if (TINY_SCRIPT <= srcBuf.length() && srcBuf.length() < HUGE_SCRIPT && canCompressOffThread) {
task->ss = this;
if (!StartOffThreadCompression(cx, task))
return false;
} else if (!ensureOwnsSource(cx)) {
return false;
}
return true;
}
SourceCompressionTask::ResultType
SourceCompressionTask::work()
{
// Try to keep the maximum memory usage down by only allocating half the
// size of the string, first.
size_t inputBytes = ss->length() * sizeof(char16_t);
size_t firstSize = inputBytes / 2;
compressed = js_malloc(firstSize);
if (!compressed)
return OOM;
Compressor comp(reinterpret_cast<const unsigned char*>(ss->uncompressedChars()), inputBytes);
if (!comp.init())
return OOM;
comp.setOutput((unsigned char*) compressed, firstSize);
bool cont = true;
while (cont) {
if (abort_)
return Aborted;
switch (comp.compressMore()) {
case Compressor::CONTINUE:
break;
case Compressor::MOREOUTPUT: {
if (comp.outWritten() == inputBytes) {
// The compressed string is longer than the original string.
return Aborted;
}
// The compressed output is greater than half the size of the
// original string. Reallocate to the full size.
compressed = js_realloc(compressed, inputBytes);
if (!compressed)
return OOM;
comp.setOutput((unsigned char*) compressed, inputBytes);
break;
}
case Compressor::DONE:
cont = false;
break;
case Compressor::OOM:
return OOM;
}
}
compressedBytes = comp.outWritten();
compressedHash = CompressedSourceHasher::computeHash(compressed, compressedBytes);
// Shrink the buffer to the size of the compressed data.
if (void* newCompressed = js_realloc(compressed, compressedBytes))
compressed = newCompressed;
return Success;
}
ScriptSource::~ScriptSource()
{
MOZ_ASSERT_IF(inCompressedSourceSet, dataType == DataCompressed);
switch (dataType) {
case DataUncompressed:
if (ownsUncompressedChars())
js_free(const_cast<char16_t*>(uncompressedChars()));
break;
case DataCompressed:
// Script source references are only manipulated on the main thread,
// except during off thread parsing when the source may be created
// and used exclusively by the thread doing the parse. In this case the
// ScriptSource might be destroyed while off the main thread, but it
// will not have been added to the runtime's compressed source set
// until the parse is finished on the main thread.
if (inCompressedSourceSet)
TlsPerThreadData.get()->runtimeFromMainThread()->compressedSourceSet.remove(this);
js_free(compressedData());
break;
case DataParent:
parent()->decref();
break;
default:
break;
}
}
void
ScriptSource::addSizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf,
JS::ScriptSourceInfo* info) const
{
if (dataType == DataUncompressed && ownsUncompressedChars())
info->uncompressed += mallocSizeOf(uncompressedChars());
else if (dataType == DataCompressed)
info->compressed += mallocSizeOf(compressedData());
info->misc += mallocSizeOf(this) +
mallocSizeOf(filename_.get()) +
mallocSizeOf(introducerFilename_.get());
info->numScripts++;
}
template<XDRMode mode>
bool
ScriptSource::performXDR(XDRState<mode>* xdr)
{
uint8_t hasSource = hasSourceData();
if (!xdr->codeUint8(&hasSource))
return false;
uint8_t retrievable = sourceRetrievable_;
if (!xdr->codeUint8(&retrievable))
return false;
sourceRetrievable_ = retrievable;
if (hasSource && !sourceRetrievable_) {
if (!xdr->codeUint32(&length_))
return false;
uint32_t compressedLength;
if (mode == XDR_ENCODE) {
switch (dataType) {
case DataUncompressed:
compressedLength = 0;
break;
case DataCompressed:
compressedLength = compressedBytes();
break;
case DataParent:
compressedLength = parent()->compressedBytes();
break;
default:
MOZ_CRASH();
}
}
if (!xdr->codeUint32(&compressedLength))
return false;
{
uint8_t argumentsNotIncluded;
if (mode == XDR_ENCODE)
argumentsNotIncluded = argumentsNotIncluded_;
if (!xdr->codeUint8(&argumentsNotIncluded))
return false;
if (mode == XDR_DECODE)
argumentsNotIncluded_ = argumentsNotIncluded;
}
size_t byteLen = compressedLength ? compressedLength : (length_ * sizeof(char16_t));
if (mode == XDR_DECODE) {
uint8_t* p = xdr->cx()->template pod_malloc<uint8_t>(Max<size_t>(byteLen, 1));
if (!p || !xdr->codeBytes(p, byteLen)) {
js_free(p);
return false;
}
if (compressedLength)
setCompressedSource(xdr->cx()->runtime(), p, compressedLength,
CompressedSourceHasher::computeHash(p, compressedLength));
else
setSource((const char16_t*) p, length_);
} else {
void* p;
switch (dataType) {
case DataUncompressed:
p = (void*) uncompressedChars();
break;
case DataCompressed:
p = compressedData();
break;
case DataParent:
p = parent()->compressedData();
break;
default:
MOZ_CRASH();
}
if (!xdr->codeBytes(p, byteLen))
return false;
}
}
uint8_t haveSourceMap = hasSourceMapURL();
if (!xdr->codeUint8(&haveSourceMap))
return false;
if (haveSourceMap) {
uint32_t sourceMapURLLen = (mode == XDR_DECODE) ? 0 : js_strlen(sourceMapURL_.get());
if (!xdr->codeUint32(&sourceMapURLLen))
return false;
if (mode == XDR_DECODE) {
sourceMapURL_ = xdr->cx()->template make_pod_array<char16_t>(sourceMapURLLen + 1);
if (!sourceMapURL_)
return false;
}
if (!xdr->codeChars(sourceMapURL_.get(), sourceMapURLLen)) {
if (mode == XDR_DECODE)
sourceMapURL_ = nullptr;
return false;
}
sourceMapURL_[sourceMapURLLen] = '\0';
}
uint8_t haveDisplayURL = hasDisplayURL();
if (!xdr->codeUint8(&haveDisplayURL))
return false;
if (haveDisplayURL) {
uint32_t displayURLLen = (mode == XDR_DECODE) ? 0 : js_strlen(displayURL_.get());
if (!xdr->codeUint32(&displayURLLen))
return false;
if (mode == XDR_DECODE) {
displayURL_ = xdr->cx()->template make_pod_array<char16_t>(displayURLLen + 1);
if (!displayURL_)
return false;
}
if (!xdr->codeChars(displayURL_.get(), displayURLLen)) {
if (mode == XDR_DECODE)
displayURL_ = nullptr;
return false;
}
displayURL_[displayURLLen] = '\0';
}
uint8_t haveFilename = !!filename_;
if (!xdr->codeUint8(&haveFilename))
return false;
if (haveFilename) {
const char* fn = filename();
if (!xdr->codeCString(&fn))
return false;
if (mode == XDR_DECODE && !setFilename(xdr->cx(), fn))
return false;
}
return true;
}
// Format and return a cx->zone()->pod_malloc'ed URL for a generated script like:
// {filename} line {lineno} > {introducer}
// For example:
// foo.js line 7 > eval
// indicating code compiled by the call to 'eval' on line 7 of foo.js.
static char*
FormatIntroducedFilename(ExclusiveContext* cx, const char* filename, unsigned lineno,
const char* introducer)
{
// Compute the length of the string in advance, so we can allocate a
// buffer of the right size on the first shot.
//
// (JS_smprintf would be perfect, as that allocates the result
// dynamically as it formats the string, but it won't allocate from cx,
// and wants us to use a special free function.)
char linenoBuf[15];
size_t filenameLen = strlen(filename);
size_t linenoLen = JS_snprintf(linenoBuf, 15, "%u", lineno);
size_t introducerLen = strlen(introducer);
size_t len = filenameLen +
6 /* == strlen(" line ") */ +
linenoLen +
3 /* == strlen(" > ") */ +
introducerLen +
1 /* \0 */;
char* formatted = cx->zone()->pod_malloc<char>(len);
if (!formatted)
return nullptr;
mozilla::DebugOnly<size_t> checkLen = JS_snprintf(formatted, len, "%s line %s > %s",
filename, linenoBuf, introducer);
MOZ_ASSERT(checkLen == len - 1);
return formatted;
}
bool
ScriptSource::initFromOptions(ExclusiveContext* cx, const ReadOnlyCompileOptions& options)
{
MOZ_ASSERT(!filename_);
MOZ_ASSERT(!introducerFilename_);
mutedErrors_ = options.mutedErrors();
introductionType_ = options.introductionType;
setIntroductionOffset(options.introductionOffset);
if (options.hasIntroductionInfo) {
MOZ_ASSERT(options.introductionType != nullptr);
const char* filename = options.filename() ? options.filename() : "<unknown>";
char* formatted = FormatIntroducedFilename(cx, filename, options.introductionLineno,
options.introductionType);
if (!formatted)
return false;
filename_.reset(formatted);
} else if (options.filename()) {
if (!setFilename(cx, options.filename()))
return false;
}
if (options.introducerFilename()) {
introducerFilename_ = DuplicateString(cx, options.introducerFilename());
if (!introducerFilename_)
return false;
}
return true;
}
bool
ScriptSource::setFilename(ExclusiveContext* cx, const char* filename)
{
MOZ_ASSERT(!filename_);
filename_ = DuplicateString(cx, filename);
return filename_ != nullptr;
}
bool
ScriptSource::setDisplayURL(ExclusiveContext* cx, const char16_t* displayURL)
{
MOZ_ASSERT(displayURL);
if (hasDisplayURL()) {
if (cx->isJSContext() &&
!JS_ReportErrorFlagsAndNumber(cx->asJSContext(), JSREPORT_WARNING,
GetErrorMessage, nullptr,
JSMSG_ALREADY_HAS_PRAGMA, filename_.get(),
"//# sourceURL"))
{
return false;
}
}
size_t len = js_strlen(displayURL) + 1;
if (len == 1)
return true;
displayURL_ = DuplicateString(cx, displayURL);
return displayURL_ != nullptr;
}
bool
ScriptSource::setSourceMapURL(ExclusiveContext* cx, const char16_t* sourceMapURL)
{
MOZ_ASSERT(sourceMapURL);
size_t len = js_strlen(sourceMapURL) + 1;
if (len == 1)
return true;
sourceMapURL_ = DuplicateString(cx, sourceMapURL);
return sourceMapURL_ != nullptr;
}
size_t
ScriptSource::computedSizeOfData() const
{
if (dataType == DataUncompressed && ownsUncompressedChars())
return sizeof(char16_t) * length_;
if (dataType == DataCompressed)
return compressedBytes();
return 0;
}
/*
* Shared script data management.
*/
SharedScriptData*
js::SharedScriptData::new_(ExclusiveContext* cx, uint32_t codeLength,
uint32_t srcnotesLength, uint32_t natoms)
{
/*
* Ensure the atoms are aligned, as some architectures don't allow unaligned
* access.
*/
const uint32_t pointerSize = sizeof(JSAtom*);
const uint32_t pointerMask = pointerSize - 1;
const uint32_t dataOffset = offsetof(SharedScriptData, data);
uint32_t baseLength = codeLength + srcnotesLength;
uint32_t padding = (pointerSize - ((baseLength + dataOffset) & pointerMask)) & pointerMask;
uint32_t length = baseLength + padding + pointerSize * natoms;
SharedScriptData* entry = reinterpret_cast<SharedScriptData*>(
cx->zone()->pod_malloc<uint8_t>(length + dataOffset));
if (!entry)
return nullptr;
entry->length = length;
entry->natoms = natoms;
entry->marked = false;
memset(entry->data + baseLength, 0, padding);
/*
* Call constructors to initialize the storage that will be accessed as a
* HeapPtrAtom array via atoms().
*/
HeapPtrAtom* atoms = entry->atoms();
MOZ_ASSERT(reinterpret_cast<uintptr_t>(atoms) % sizeof(JSAtom*) == 0);
for (unsigned i = 0; i < natoms; ++i)
new (&atoms[i]) HeapPtrAtom();
return entry;
}
/*
* Takes ownership of its *ssd parameter and either adds it into the runtime's
* ScriptDataTable or frees it if a matching entry already exists.
*
* Sets the |code| and |atoms| fields on the given JSScript.
*/
static bool
SaveSharedScriptData(ExclusiveContext* cx, Handle<JSScript*> script, SharedScriptData* ssd,
uint32_t nsrcnotes)
{
MOZ_ASSERT(script != nullptr);
MOZ_ASSERT(ssd != nullptr);
AutoLockForExclusiveAccess lock(cx);
ScriptBytecodeHasher::Lookup l(ssd);
ScriptDataTable::AddPtr p = cx->scriptDataTable().lookupForAdd(l);
if (p) {
js_free(ssd);
ssd = *p;
} else {
if (!cx->scriptDataTable().add(p, ssd)) {
script->setCode(nullptr);
script->atoms = nullptr;
js_free(ssd);
ReportOutOfMemory(cx);
return false;
}
}
/*
* During the IGC we need to ensure that bytecode is marked whenever it is
* accessed even if the bytecode was already in the table: at this point
* old scripts or exceptions pointing to the bytecode may no longer be
* reachable. This is effectively a read barrier.
*/
if (cx->isJSContext()) {
JSRuntime* rt = cx->asJSContext()->runtime();
if (JS::IsIncrementalGCInProgress(rt) && rt->gc.isFullGc())
ssd->marked = true;
}
script->setCode(ssd->data);
script->atoms = ssd->atoms();
return true;
}
static inline void
MarkScriptData(JSRuntime* rt, const jsbytecode* bytecode)
{
/*
* As an invariant, a ScriptBytecodeEntry should not be 'marked' outside of
* a GC. Since SweepScriptBytecodes is only called during a full gc,
* to preserve this invariant, only mark during a full gc.
*/
if (rt->gc.isFullGc())
SharedScriptData::fromBytecode(bytecode)->marked = true;
}
void
js::UnmarkScriptData(JSRuntime* rt)
{
MOZ_ASSERT(rt->gc.isFullGc());
ScriptDataTable& table = rt->scriptDataTable();
for (ScriptDataTable::Enum e(table); !e.empty(); e.popFront()) {
SharedScriptData* entry = e.front();
entry->marked = false;
}
}
void
js::SweepScriptData(JSRuntime* rt)
{
MOZ_ASSERT(rt->gc.isFullGc());
ScriptDataTable& table = rt->scriptDataTable();
if (rt->keepAtoms())
return;
for (ScriptDataTable::Enum e(table); !e.empty(); e.popFront()) {
SharedScriptData* entry = e.front();
if (!entry->marked) {
js_free(entry);
e.removeFront();
}
}
}
void
js::FreeScriptData(JSRuntime* rt)
{
ScriptDataTable& table = rt->scriptDataTable();
if (!table.initialized())
return;
for (ScriptDataTable::Enum e(table); !e.empty(); e.popFront())
js_free(e.front());
table.clear();
}
/*
* JSScript::data and SharedScriptData::data have complex,
* manually-controlled, memory layouts.
*
* JSScript::data begins with some optional array headers. They are optional
* because they often aren't needed, i.e. the corresponding arrays often have
* zero elements. Each header has a bit in JSScript::hasArrayBits that
* indicates if it's present within |data|; from this the offset of each
* present array header can be computed. Each header has an accessor function
* in JSScript that encapsulates this offset computation.
*
* Array type Array elements Accessor
* ---------- -------------- --------
* ConstArray Consts consts()
* ObjectArray Objects objects()
* ObjectArray Regexps regexps()
* TryNoteArray Try notes trynotes()
* BlockScopeArray Scope notes blockScopes()
*
* Then are the elements of several arrays.
* - Most of these arrays have headers listed above (if present). For each of
* these, the array pointer and the array length is stored in the header.
* - The remaining arrays have pointers and lengths that are stored directly in
* JSScript. This is because, unlike the others, they are nearly always
* non-zero length and so the optional-header space optimization isn't
* worthwhile.
*
* Array elements Pointed to by Length
* -------------- ------------- ------
* Consts consts()->vector consts()->length
* Objects objects()->vector objects()->length
* Regexps regexps()->vector regexps()->length
* Try notes trynotes()->vector trynotes()->length
* Scope notes blockScopes()->vector blockScopes()->length
*
* IMPORTANT: This layout has two key properties.
* - It ensures that everything has sufficient alignment; in particular, the
* consts() elements need jsval alignment.
* - It ensures there are no gaps between elements, which saves space and makes
* manual layout easy. In particular, in the second part, arrays with larger
* elements precede arrays with smaller elements.
*
* SharedScriptData::data contains data that can be shared within a
* runtime. These items' layout is manually controlled to make it easier to
* manage both during (temporary) allocation and during matching against
* existing entries in the runtime. As the jsbytecode has to come first to
* enable lookup by bytecode identity, SharedScriptData::data, the atoms part
* has to manually be aligned sufficiently by adding padding after the notes
* part.
*
* Array elements Pointed to by Length
* -------------- ------------- ------
* jsbytecode code length
* jsscrnote notes() numNotes()
* Atoms atoms natoms
*
* The following static assertions check JSScript::data's alignment properties.
*/
#define KEEPS_JSVAL_ALIGNMENT(T) \
(JS_ALIGNMENT_OF(jsval) % JS_ALIGNMENT_OF(T) == 0 && \
sizeof(T) % sizeof(jsval) == 0)
#define HAS_JSVAL_ALIGNMENT(T) \
(JS_ALIGNMENT_OF(jsval) == JS_ALIGNMENT_OF(T) && \
sizeof(T) == sizeof(jsval))
#define NO_PADDING_BETWEEN_ENTRIES(T1, T2) \
(JS_ALIGNMENT_OF(T1) % JS_ALIGNMENT_OF(T2) == 0)
/*
* These assertions ensure that there is no padding between the array headers,
* and also that the consts() elements (which follow immediately afterward) are
* jsval-aligned. (There is an assumption that |data| itself is jsval-aligned;
* we check this below).
*/
JS_STATIC_ASSERT(KEEPS_JSVAL_ALIGNMENT(ConstArray));
JS_STATIC_ASSERT(KEEPS_JSVAL_ALIGNMENT(ObjectArray)); /* there are two of these */
JS_STATIC_ASSERT(KEEPS_JSVAL_ALIGNMENT(TryNoteArray));
JS_STATIC_ASSERT(KEEPS_JSVAL_ALIGNMENT(BlockScopeArray));
/* These assertions ensure there is no padding required between array elements. */
JS_STATIC_ASSERT(HAS_JSVAL_ALIGNMENT(HeapValue));
JS_STATIC_ASSERT(NO_PADDING_BETWEEN_ENTRIES(HeapValue, HeapPtrObject));
JS_STATIC_ASSERT(NO_PADDING_BETWEEN_ENTRIES(HeapPtrObject, HeapPtrObject));
JS_STATIC_ASSERT(NO_PADDING_BETWEEN_ENTRIES(HeapPtrObject, JSTryNote));
JS_STATIC_ASSERT(NO_PADDING_BETWEEN_ENTRIES(JSTryNote, uint32_t));
JS_STATIC_ASSERT(NO_PADDING_BETWEEN_ENTRIES(uint32_t, uint32_t));
JS_STATIC_ASSERT(NO_PADDING_BETWEEN_ENTRIES(HeapValue, BlockScopeNote));
JS_STATIC_ASSERT(NO_PADDING_BETWEEN_ENTRIES(BlockScopeNote, BlockScopeNote));
JS_STATIC_ASSERT(NO_PADDING_BETWEEN_ENTRIES(JSTryNote, BlockScopeNote));
JS_STATIC_ASSERT(NO_PADDING_BETWEEN_ENTRIES(HeapPtrObject, BlockScopeNote));
JS_STATIC_ASSERT(NO_PADDING_BETWEEN_ENTRIES(BlockScopeNote, uint32_t));
static inline size_t
ScriptDataSize(uint32_t nbindings, uint32_t nconsts, uint32_t nobjects, uint32_t nregexps,
uint32_t ntrynotes, uint32_t nblockscopes, uint32_t nyieldoffsets)
{
size_t size = 0;
if (nconsts != 0)
size += sizeof(ConstArray) + nconsts * sizeof(Value);
if (nobjects != 0)
size += sizeof(ObjectArray) + nobjects * sizeof(NativeObject*);
if (nregexps != 0)
size += sizeof(ObjectArray) + nregexps * sizeof(NativeObject*);
if (ntrynotes != 0)
size += sizeof(TryNoteArray) + ntrynotes * sizeof(JSTryNote);
if (nblockscopes != 0)
size += sizeof(BlockScopeArray) + nblockscopes * sizeof(BlockScopeNote);
if (nyieldoffsets != 0)
size += sizeof(YieldOffsetArray) + nyieldoffsets * sizeof(uint32_t);
if (nbindings != 0) {
// Make sure bindings are sufficiently aligned.
size = JS_ROUNDUP(size, JS_ALIGNMENT_OF(Binding)) + nbindings * sizeof(Binding);
}
return size;
}
void
JSScript::initCompartment(ExclusiveContext* cx)
{
compartment_ = cx->compartment_;
}
JSScript*
JSScript::Create(ExclusiveContext* cx, HandleObject enclosingScope, bool savedCallerFun,
const ReadOnlyCompileOptions& options, unsigned staticLevel,
HandleObject sourceObject, uint32_t bufStart, uint32_t bufEnd)
{
MOZ_ASSERT(bufStart <= bufEnd);
RootedScript script(cx, Allocate<JSScript>(cx));
if (!script)
return nullptr;
PodZero(script.get());
new (&script->bindings) Bindings;
script->enclosingStaticScope_ = enclosingScope;
script->savedCallerFun_ = savedCallerFun;
script->initCompartment(cx);
script->compileAndGo_ = options.compileAndGo;
script->hasPollutedGlobalScope_ = options.hasPollutedGlobalScope;
script->selfHosted_ = options.selfHostingMode;
script->noScriptRval_ = options.noScriptRval;
script->version = options.version;
MOZ_ASSERT(script->getVersion() == options.version); // assert that no overflow occurred
// This is an unsigned-to-uint16_t conversion, test for too-high values.
// In practice, recursion in Parser and/or BytecodeEmitter will blow the
// stack if we nest functions more than a few hundred deep, so this will
// never trigger. Oh well.
if (staticLevel > UINT16_MAX) {
if (cx->isJSContext()) {
JS_ReportErrorNumber(cx->asJSContext(),
GetErrorMessage, nullptr, JSMSG_TOO_DEEP, js_function_str);
}
return nullptr;
}
script->staticLevel_ = uint16_t(staticLevel);
script->setSourceObject(sourceObject);
script->sourceStart_ = bufStart;
script->sourceEnd_ = bufEnd;
return script;
}
static inline uint8_t*
AllocScriptData(JS::Zone* zone, size_t size)
{
if (!size)
return nullptr;
uint8_t* data = zone->pod_calloc<uint8_t>(JS_ROUNDUP(size, sizeof(Value)));
if (!data)
return nullptr;
MOZ_ASSERT(size_t(data) % sizeof(Value) == 0);
return data;
}
/* static */ bool
JSScript::partiallyInit(ExclusiveContext* cx, HandleScript script, uint32_t nconsts,
uint32_t nobjects, uint32_t nregexps, uint32_t ntrynotes,
uint32_t nblockscopes, uint32_t nyieldoffsets, uint32_t nTypeSets)
{
size_t size = ScriptDataSize(script->bindings.count(), nconsts, nobjects, nregexps, ntrynotes,
nblockscopes, nyieldoffsets);
script->data = AllocScriptData(script->zone(), size);
if (size && !script->data)
return false;
script->dataSize_ = size;
MOZ_ASSERT(nTypeSets <= UINT16_MAX);
script->nTypeSets_ = uint16_t(nTypeSets);
uint8_t* cursor = script->data;
if (nconsts != 0) {
script->setHasArray(CONSTS);
cursor += sizeof(ConstArray);
}
if (nobjects != 0) {
script->setHasArray(OBJECTS);
cursor += sizeof(ObjectArray);
}
if (nregexps != 0) {
script->setHasArray(REGEXPS);
cursor += sizeof(ObjectArray);
}
if (ntrynotes != 0) {
script->setHasArray(TRYNOTES);
cursor += sizeof(TryNoteArray);
}
if (nblockscopes != 0) {
script->setHasArray(BLOCK_SCOPES);
cursor += sizeof(BlockScopeArray);
}
YieldOffsetArray* yieldOffsets = nullptr;
if (nyieldoffsets != 0) {
yieldOffsets = reinterpret_cast<YieldOffsetArray*>(cursor);
cursor += sizeof(YieldOffsetArray);
}
if (nconsts != 0) {
MOZ_ASSERT(reinterpret_cast<uintptr_t>(cursor) % sizeof(jsval) == 0);
script->consts()->length = nconsts;
script->consts()->vector = (HeapValue*)cursor;
cursor += nconsts * sizeof(script->consts()->vector[0]);
}
if (nobjects != 0) {
script->objects()->length = nobjects;
script->objects()->vector = (HeapPtrObject*)cursor;
cursor += nobjects * sizeof(script->objects()->vector[0]);
}
if (nregexps != 0) {
script->regexps()->length = nregexps;
script->regexps()->vector = (HeapPtrObject*)cursor;
cursor += nregexps * sizeof(script->regexps()->vector[0]);
}
if (ntrynotes != 0) {
script->trynotes()->length = ntrynotes;
script->trynotes()->vector = reinterpret_cast<JSTryNote*>(cursor);
size_t vectorSize = ntrynotes * sizeof(script->trynotes()->vector[0]);
#ifdef DEBUG
memset(cursor, 0, vectorSize);
#endif
cursor += vectorSize;
}
if (nblockscopes != 0) {
script->blockScopes()->length = nblockscopes;
script->blockScopes()->vector = reinterpret_cast<BlockScopeNote*>(cursor);
size_t vectorSize = nblockscopes * sizeof(script->blockScopes()->vector[0]);
#ifdef DEBUG
memset(cursor, 0, vectorSize);
#endif
cursor += vectorSize;
}
if (nyieldoffsets != 0) {
yieldOffsets->init(reinterpret_cast<uint32_t*>(cursor), nyieldoffsets);
size_t vectorSize = nyieldoffsets * sizeof(script->yieldOffsets()[0]);
#ifdef DEBUG
memset(cursor, 0, vectorSize);
#endif
cursor += vectorSize;
}
if (script->bindings.count() != 0) {
// Make sure bindings are sufficiently aligned.
cursor = reinterpret_cast<uint8_t*>
(JS_ROUNDUP(reinterpret_cast<uintptr_t>(cursor), JS_ALIGNMENT_OF(Binding)));
}
cursor = script->bindings.switchToScriptStorage(reinterpret_cast<Binding*>(cursor));
MOZ_ASSERT(cursor == script->data + size);
return true;
}
/* static */ bool
JSScript::fullyInitTrivial(ExclusiveContext* cx, Handle<JSScript*> script)
{
if (!partiallyInit(cx, script, 0, 0, 0, 0, 0, 0, 0))
return false;
SharedScriptData* ssd = SharedScriptData::new_(cx, 1, 1, 0);
if (!ssd)
return false;
ssd->data[0] = JSOP_RETRVAL;
ssd->data[1] = SRC_NULL;
script->setLength(1);
return SaveSharedScriptData(cx, script, ssd, 1);
}
/* static */ bool
JSScript::fullyInitFromEmitter(ExclusiveContext* cx, HandleScript script, BytecodeEmitter* bce)
{
/* The counts of indexed things must be checked during code generation. */
MOZ_ASSERT(bce->atomIndices->count() <= INDEX_LIMIT);
MOZ_ASSERT(bce->objectList.length <= INDEX_LIMIT);
MOZ_ASSERT(bce->regexpList.length <= INDEX_LIMIT);
uint32_t mainLength = bce->offset();
uint32_t prologLength = bce->prologOffset();
uint32_t nsrcnotes;
if (!bce->finishTakingSrcNotes(&nsrcnotes))
return false;
uint32_t natoms = bce->atomIndices->count();
if (!partiallyInit(cx, script,
bce->constList.length(), bce->objectList.length, bce->regexpList.length,
bce->tryNoteList.length(), bce->blockScopeList.length(),
bce->yieldOffsetList.length(), bce->typesetCount))
{
return false;
}
MOZ_ASSERT(script->mainOffset() == 0);
script->mainOffset_ = prologLength;
script->lineno_ = bce->firstLine;
script->setLength(prologLength + mainLength);
script->natoms_ = natoms;
SharedScriptData* ssd = SharedScriptData::new_(cx, script->length(), nsrcnotes, natoms);
if (!ssd)
return false;
jsbytecode* code = ssd->data;
PodCopy<jsbytecode>(code, bce->prolog.code.begin(), prologLength);
PodCopy<jsbytecode>(code + prologLength, bce->code().begin(), mainLength);
bce->copySrcNotes((jssrcnote*)(code + script->length()), nsrcnotes);
InitAtomMap(bce->atomIndices.getMap(), ssd->atoms());
if (!SaveSharedScriptData(cx, script, ssd, nsrcnotes))
return false;
FunctionBox* funbox = bce->sc->isFunctionBox() ? bce->sc->asFunctionBox() : nullptr;
if (bce->constList.length() != 0)
bce->constList.finish(script->consts());
if (bce->objectList.length != 0)
bce->objectList.finish(script->objects());
if (bce->regexpList.length != 0)
bce->regexpList.finish(script->regexps());
if (bce->tryNoteList.length() != 0)
bce->tryNoteList.finish(script->trynotes());
if (bce->blockScopeList.length() != 0)
bce->blockScopeList.finish(script->blockScopes());
script->strict_ = bce->sc->strict();
script->explicitUseStrict_ = bce->sc->hasExplicitUseStrict();
script->bindingsAccessedDynamically_ = bce->sc->bindingsAccessedDynamically();
script->funHasExtensibleScope_ = funbox ? funbox->hasExtensibleScope() : false;
script->funNeedsDeclEnvObject_ = funbox ? funbox->needsDeclEnvObject() : false;
script->hasSingletons_ = bce->hasSingletons;
if (funbox) {
if (funbox->argumentsHasLocalBinding()) {
// This must precede the script->bindings.transfer() call below
script->setArgumentsHasVarBinding();
if (funbox->definitelyNeedsArgsObj())
script->setNeedsArgsObj(true);
} else {
MOZ_ASSERT(!funbox->definitelyNeedsArgsObj());
}
script->funLength_ = funbox->length;
}
RootedFunction fun(cx, nullptr);
if (funbox) {
MOZ_ASSERT(!bce->script->noScriptRval());
script->isGeneratorExp_ = funbox->inGenexpLambda;
script->setGeneratorKind(funbox->generatorKind());
script->setFunction(funbox->function());
if (bce->yieldOffsetList.length() != 0)
bce->yieldOffsetList.finish(script->yieldOffsets(), prologLength);
}
// The call to nfixed() depends on the above setFunction() call.
if (UINT32_MAX - script->nfixed() < bce->maxStackDepth) {
bce->reportError(nullptr, JSMSG_NEED_DIET, "script");
return false;
}
script->nslots_ = script->nfixed() + bce->maxStackDepth;
for (unsigned i = 0, n = script->bindings.numArgs(); i < n; ++i) {
if (script->formalIsAliased(i)) {
script->funHasAnyAliasedFormal_ = true;
break;
}
}
return true;
}
size_t
JSScript::computedSizeOfData() const
{
return dataSize();
}
size_t
JSScript::sizeOfData(mozilla::MallocSizeOf mallocSizeOf) const
{
return mallocSizeOf(data);
}
size_t
JSScript::sizeOfTypeScript(mozilla::MallocSizeOf mallocSizeOf) const
{
return types_->sizeOfIncludingThis(mallocSizeOf);
}
/*
* Nb: srcnotes are variable-length. This function computes the number of
* srcnote *slots*, which may be greater than the number of srcnotes.
*/
uint32_t
JSScript::numNotes()
{
jssrcnote* sn;
jssrcnote* notes_ = notes();
for (sn = notes_; !SN_IS_TERMINATOR(sn); sn = SN_NEXT(sn))
continue;
return sn - notes_ + 1; /* +1 for the terminator */
}
js::GlobalObject&
JSScript::uninlinedGlobal() const
{
return global();
}
void
JSScript::finalize(FreeOp* fop)
{
// NOTE: this JSScript may be partially initialized at this point. E.g. we
// may have created it and partially initialized it with
// JSScript::Create(), but not yet finished initializing it with
// fullyInitFromEmitter() or fullyInitTrivial().
fop->runtime()->spsProfiler.onScriptFinalized(this);
if (types_)
types_->destroy();
jit::DestroyJitScripts(fop, this);
destroyScriptCounts(fop);
destroyDebugScript(fop);
if (data) {
JS_POISON(data, 0xdb, computedSizeOfData());
fop->free_(data);
}
fop->runtime()->lazyScriptCache.remove(this);
}
static const uint32_t GSN_CACHE_THRESHOLD = 100;
void
GSNCache::purge()
{
code = nullptr;
if (map.initialized())
map.finish();
}
jssrcnote*
js::GetSrcNote(GSNCache& cache, JSScript* script, jsbytecode* pc)
{
size_t target = pc - script->code();
if (target >= script->length())
return nullptr;
if (cache.code == script->code()) {
MOZ_ASSERT(cache.map.initialized());
GSNCache::Map::Ptr p = cache.map.lookup(pc);
return p ? p->value() : nullptr;
}
size_t offset = 0;
jssrcnote* result;
for (jssrcnote* sn = script->notes(); ; sn = SN_NEXT(sn)) {
if (SN_IS_TERMINATOR(sn)) {
result = nullptr;
break;
}
offset += SN_DELTA(sn);
if (offset == target && SN_IS_GETTABLE(sn)) {
result = sn;
break;
}
}
if (cache.code != script->code() && script->length() >= GSN_CACHE_THRESHOLD) {
unsigned nsrcnotes = 0;
for (jssrcnote* sn = script->notes(); !SN_IS_TERMINATOR(sn);
sn = SN_NEXT(sn)) {
if (SN_IS_GETTABLE(sn))
++nsrcnotes;
}
if (cache.code) {
MOZ_ASSERT(cache.map.initialized());
cache.map.finish();
cache.code = nullptr;
}
if (cache.map.init(nsrcnotes)) {
pc = script->code();
for (jssrcnote* sn = script->notes(); !SN_IS_TERMINATOR(sn);
sn = SN_NEXT(sn)) {
pc += SN_DELTA(sn);
if (SN_IS_GETTABLE(sn))
JS_ALWAYS_TRUE(cache.map.put(pc, sn));
}
cache.code = script->code();
}
}
return result;
}
jssrcnote*
js::GetSrcNote(JSContext* cx, JSScript* script, jsbytecode* pc)
{
return GetSrcNote(cx->runtime()->gsnCache, script, pc);
}
unsigned
js::PCToLineNumber(unsigned startLine, jssrcnote* notes, jsbytecode* code, jsbytecode* pc,
unsigned* columnp)
{
unsigned lineno = startLine;
unsigned column = 0;
/*
* Walk through source notes accumulating their deltas, keeping track of
* line-number notes, until we pass the note for pc's offset within
* script->code.
*/
ptrdiff_t offset = 0;
ptrdiff_t target = pc - code;
for (jssrcnote* sn = notes; !SN_IS_TERMINATOR(sn); sn = SN_NEXT(sn)) {
offset += SN_DELTA(sn);
SrcNoteType type = (SrcNoteType) SN_TYPE(sn);
if (type == SRC_SETLINE) {
if (offset <= target)
lineno = unsigned(GetSrcNoteOffset(sn, 0));
column = 0;
} else if (type == SRC_NEWLINE) {
if (offset <= target)
lineno++;
column = 0;
}
if (offset > target)
break;
if (type == SRC_COLSPAN) {
ptrdiff_t colspan = SN_OFFSET_TO_COLSPAN(GetSrcNoteOffset(sn, 0));
MOZ_ASSERT(ptrdiff_t(column) + colspan >= 0);
column += colspan;
}
}
if (columnp)
*columnp = column;
return lineno;
}
unsigned
js::PCToLineNumber(JSScript* script, jsbytecode* pc, unsigned* columnp)
{
/* Cope with InterpreterFrame.pc value prior to entering Interpret. */
if (!pc)
return 0;
return PCToLineNumber(script->lineno(), script->notes(), script->code(), pc, columnp);
}
jsbytecode*
js::LineNumberToPC(JSScript* script, unsigned target)
{
ptrdiff_t offset = 0;
ptrdiff_t best = -1;
unsigned lineno = script->lineno();
unsigned bestdiff = SN_MAX_OFFSET;
for (jssrcnote* sn = script->notes(); !SN_IS_TERMINATOR(sn); sn = SN_NEXT(sn)) {
/*
* Exact-match only if offset is not in the prolog; otherwise use
* nearest greater-or-equal line number match.
*/
if (lineno == target && offset >= ptrdiff_t(script->mainOffset()))
goto out;
if (lineno >= target) {
unsigned diff = lineno - target;
if (diff < bestdiff) {
bestdiff = diff;
best = offset;
}
}
offset += SN_DELTA(sn);
SrcNoteType type = (SrcNoteType) SN_TYPE(sn);
if (type == SRC_SETLINE) {
lineno = unsigned(GetSrcNoteOffset(sn, 0));
} else if (type == SRC_NEWLINE) {
lineno++;
}
}
if (best >= 0)
offset = best;
out:
return script->offsetToPC(offset);
}
JS_FRIEND_API(unsigned)
js::GetScriptLineExtent(JSScript* script)
{
unsigned lineno = script->lineno();
unsigned maxLineNo = lineno;
for (jssrcnote* sn = script->notes(); !SN_IS_TERMINATOR(sn); sn = SN_NEXT(sn)) {
SrcNoteType type = (SrcNoteType) SN_TYPE(sn);
if (type == SRC_SETLINE)
lineno = unsigned(GetSrcNoteOffset(sn, 0));
else if (type == SRC_NEWLINE)
lineno++;
if (maxLineNo < lineno)
maxLineNo = lineno;
}
return 1 + maxLineNo - script->lineno();
}
void
js::DescribeScriptedCallerForCompilation(JSContext* cx, MutableHandleScript maybeScript,
const char** file, unsigned* linenop,
uint32_t* pcOffset, bool* mutedErrors,
LineOption opt)
{
if (opt == CALLED_FROM_JSOP_EVAL) {
jsbytecode* pc = nullptr;
maybeScript.set(cx->currentScript(&pc));
static_assert(JSOP_SPREADEVAL_LENGTH == JSOP_STRICTSPREADEVAL_LENGTH,
"next op after a spread must be at consistent offset");
static_assert(JSOP_EVAL_LENGTH == JSOP_STRICTEVAL_LENGTH,
"next op after a direct eval must be at consistent offset");
MOZ_ASSERT(JSOp(*pc) == JSOP_EVAL || JSOp(*pc) == JSOP_STRICTEVAL ||
JSOp(*pc) == JSOP_SPREADEVAL || JSOp(*pc) == JSOP_STRICTSPREADEVAL);
bool isSpread = JSOp(*pc) == JSOP_SPREADEVAL || JSOp(*pc) == JSOP_STRICTSPREADEVAL;
jsbytecode* nextpc = pc + (isSpread ? JSOP_SPREADEVAL_LENGTH : JSOP_EVAL_LENGTH);
MOZ_ASSERT(*nextpc == JSOP_LINENO);
*file = maybeScript->filename();
*linenop = GET_UINT32(nextpc);
*pcOffset = pc - maybeScript->code();
*mutedErrors = maybeScript->mutedErrors();
return;
}
NonBuiltinFrameIter iter(cx);
if (iter.done()) {
maybeScript.set(nullptr);
*file = nullptr;
*linenop = 0;
*pcOffset = 0;
*mutedErrors = false;
return;
}
*file = iter.scriptFilename();
*linenop = iter.computeLine();
*mutedErrors = iter.mutedErrors();
// These values are only used for introducer fields which are debugging
// information and can be safely left null for asm.js frames.
if (iter.hasScript()) {
maybeScript.set(iter.script());
*pcOffset = iter.pc() - maybeScript->code();
} else {
maybeScript.set(nullptr);
*pcOffset = 0;
}
}
template <class T>
static inline T*
Rebase(JSScript* dst, JSScript* src, T* srcp)
{
size_t off = reinterpret_cast<uint8_t*>(srcp) - src->data;
return reinterpret_cast<T*>(dst->data + off);
}
JSScript*
js::CloneScript(JSContext* cx, HandleObject enclosingScope, HandleFunction fun, HandleScript src,
PollutedGlobalScopeOption polluted /* = HasCleanGlobalScope */,
NewObjectKind newKind /* = GenericObject */)
{
/* NB: Keep this in sync with XDRScript. */
/* Some embeddings are not careful to use ExposeObjectToActiveJS as needed. */
MOZ_ASSERT(!src->sourceObject()->asTenured().isMarked(gc::GRAY));
uint32_t nconsts = src->hasConsts() ? src->consts()->length : 0;
uint32_t nobjects = src->hasObjects() ? src->objects()->length : 0;
uint32_t nregexps = src->hasRegexps() ? src->regexps()->length : 0;
uint32_t ntrynotes = src->hasTrynotes() ? src->trynotes()->length : 0;
uint32_t nblockscopes = src->hasBlockScopes() ? src->blockScopes()->length : 0;
/* Script data */
size_t size = src->dataSize();
uint8_t* data = AllocScriptData(cx->zone(), size);
if (size && !data)
return nullptr;
/* Bindings */
Rooted<Bindings> bindings(cx);
InternalHandle<Bindings*> bindingsHandle =
InternalHandle<Bindings*>::fromMarkedLocation(bindings.address());
if (!Bindings::clone(cx, bindingsHandle, data, src))
return nullptr;
/* Objects */
AutoObjectVector objects(cx);
if (nobjects != 0) {
HeapPtrObject* vector = src->objects()->vector;
for (unsigned i = 0; i < nobjects; i++) {
RootedObject obj(cx, vector[i]);
RootedObject clone(cx);
if (obj->is<NestedScopeObject>()) {
Rooted<NestedScopeObject*> innerBlock(cx, &obj->as<NestedScopeObject>());
RootedObject enclosingScope(cx);
if (NestedScopeObject* enclosingBlock = innerBlock->enclosingNestedScope())
enclosingScope = objects[FindScopeObjectIndex(src, *enclosingBlock)];
else
enclosingScope = fun;
clone = CloneNestedScopeObject(cx, enclosingScope, innerBlock);
} else if (obj->is<JSFunction>()) {
RootedFunction innerFun(cx, &obj->as<JSFunction>());
if (innerFun->isNative()) {
if (cx->compartment() != innerFun->compartment()) {
MOZ_ASSERT(innerFun->isAsmJSNative());
JS_ReportError(cx, "AsmJS modules do not yet support cloning.");
return nullptr;
}
clone = innerFun;
} else {
if (innerFun->isInterpretedLazy()) {
AutoCompartment ac(cx, innerFun);
if (!innerFun->getOrCreateScript(cx))
return nullptr;
}
RootedObject staticScope(cx, innerFun->nonLazyScript()->enclosingStaticScope());
StaticScopeIter<CanGC> ssi(cx, staticScope);
RootedObject enclosingScope(cx);
if (ssi.done() || ssi.type() == StaticScopeIter<CanGC>::Function)
enclosingScope = fun;
else if (ssi.type() == StaticScopeIter<CanGC>::Block)
enclosingScope = objects[FindScopeObjectIndex(src, ssi.block())];
else
enclosingScope = objects[FindScopeObjectIndex(src, ssi.staticWith())];
clone = CloneFunctionAndScript(cx, enclosingScope, innerFun, polluted);
}
} else {
/*
* Clone object literals emitted for the JSOP_NEWOBJECT opcode. We only emit that
* instead of the less-optimized JSOP_NEWINIT for self-hosted code or code compiled
* with JSOPTION_COMPILE_N_GO set. As we don't clone the latter type of code, this
* case should only ever be hit when cloning objects from self-hosted code.
*/
clone = CloneObjectLiteral(cx, obj);
}
if (!clone || !objects.append(clone))
return nullptr;
}
}
/* RegExps */
AutoObjectVector regexps(cx);
for (unsigned i = 0; i < nregexps; i++) {
HeapPtrObject* vector = src->regexps()->vector;
for (unsigned i = 0; i < nregexps; i++) {
JSObject* clone = CloneScriptRegExpObject(cx, vector[i]->as<RegExpObject>());
if (!clone || !regexps.append(clone))
return nullptr;
}
}
/*
* Wrap the script source object as needed. Self-hosted scripts may be
* in another runtime, so lazily create a new script source object to
* use for them.
*/
RootedObject sourceObject(cx);
if (cx->runtime()->isSelfHostingCompartment(src->compartment())) {
if (!cx->compartment()->selfHostingScriptSource) {
CompileOptions options(cx);
FillSelfHostingCompileOptions(options);
ScriptSourceObject* obj = frontend::CreateScriptSourceObject(cx, options);
if (!obj)
return nullptr;
cx->compartment()->selfHostingScriptSource.set(obj);
}
sourceObject = cx->compartment()->selfHostingScriptSource;
} else {
sourceObject = src->sourceObject();
if (!cx->compartment()->wrap(cx, &sourceObject))
return nullptr;
}
/* Now that all fallible allocation is complete, create the GC thing. */
CompileOptions options(cx);
options.setMutedErrors(src->mutedErrors())
.setCompileAndGo(src->compileAndGo())
.setHasPollutedScope(src->hasPollutedGlobalScope() ||
polluted == HasPollutedGlobalScope)
.setSelfHostingMode(src->selfHosted())
.setNoScriptRval(src->noScriptRval())
.setVersion(src->getVersion());
RootedScript dst(cx, JSScript::Create(cx, enclosingScope, src->savedCallerFun(),
options, src->staticLevel(),
sourceObject, src->sourceStart(), src->sourceEnd()));
if (!dst) {
js_free(data);
return nullptr;
}
dst->bindings = bindings;
/* This assignment must occur before all the Rebase calls. */
dst->data = data;
dst->dataSize_ = size;
memcpy(data, src->data, size);
/* Script filenames, bytecodes and atoms are runtime-wide. */
dst->setCode(src->code());
dst->atoms = src->atoms;
dst->setLength(src->length());
dst->lineno_ = src->lineno();
dst->mainOffset_ = src->mainOffset();
dst->natoms_ = src->natoms();
dst->funLength_ = src->funLength();
dst->nTypeSets_ = src->nTypeSets();
dst->nslots_ = src->nslots();
if (src->argumentsHasVarBinding()) {
dst->setArgumentsHasVarBinding();
if (src->analyzedArgsUsage())
dst->setNeedsArgsObj(src->needsArgsObj());
}
dst->cloneHasArray(src);
dst->strict_ = src->strict();
dst->explicitUseStrict_ = src->explicitUseStrict();
dst->bindingsAccessedDynamically_ = src->bindingsAccessedDynamically();
dst->funHasExtensibleScope_ = src->funHasExtensibleScope();
dst->funNeedsDeclEnvObject_ = src->funNeedsDeclEnvObject();
dst->funHasAnyAliasedFormal_ = src->funHasAnyAliasedFormal();
dst->hasSingletons_ = src->hasSingletons();
dst->treatAsRunOnce_ = src->treatAsRunOnce();
dst->isGeneratorExp_ = src->isGeneratorExp();
dst->setGeneratorKind(src->generatorKind());
if (nconsts != 0) {
HeapValue* vector = Rebase<HeapValue>(dst, src, src->consts()->vector);
dst->consts()->vector = vector;
for (unsigned i = 0; i < nconsts; ++i)
MOZ_ASSERT_IF(vector[i].isMarkable(), vector[i].toString()->isAtom());
}
if (nobjects != 0) {
HeapPtrObject* vector = Rebase<HeapPtrObject>(dst, src, src->objects()->vector);
dst->objects()->vector = vector;
for (unsigned i = 0; i < nobjects; ++i)
vector[i].init(&objects[i]->as<NativeObject>());
}
if (nregexps != 0) {
HeapPtrObject* vector = Rebase<HeapPtrObject>(dst, src, src->regexps()->vector);
dst->regexps()->vector = vector;
for (unsigned i = 0; i < nregexps; ++i)
vector[i].init(®exps[i]->as<NativeObject>());
}
if (ntrynotes != 0)
dst->trynotes()->vector = Rebase<JSTryNote>(dst, src, src->trynotes()->vector);
if (nblockscopes != 0)
dst->blockScopes()->vector = Rebase<BlockScopeNote>(dst, src, src->blockScopes()->vector);
/*
* Function delazification assumes that their script does not have a
* polluted global scope. We ensure that as follows:
*
* 1) Initial parsing only creates lazy functions if
* !hasPollutedGlobalScope.
* 2) Cloning a lazy function into a non-global scope will always require
* that its script be cloned. See comments in
* CloneFunctionObjectUseSameScript.
* 3) Cloning a script never sets a lazyScript on the clone, so the function
* cannot be relazified.
*
* If you decide that lazy functions should be supported with a polluted
* global scope, make sure delazification can deal.
*/
MOZ_ASSERT_IF(dst->hasPollutedGlobalScope(), !dst->maybeLazyScript());
MOZ_ASSERT_IF(dst->hasPollutedGlobalScope(), !dst->isRelazifiable());
return dst;
}
bool
js::CloneFunctionScript(JSContext* cx, HandleFunction original, HandleFunction clone,
PollutedGlobalScopeOption polluted, NewObjectKind newKind)
{
RootedScript script(cx, clone->nonLazyScript());
MOZ_ASSERT(script);
MOZ_ASSERT(script->compartment() == original->compartment());
// The only scripts with enclosing static scopes that may be cloned across
// compartments are non-strict, indirect eval scripts, as their dynamic
// scope chains terminate in the global scope immediately.
RootedObject scope(cx, script->enclosingStaticScope());
if (script->compartment() != cx->compartment() && scope) {
MOZ_ASSERT(!scope->as<StaticEvalObject>().isDirect() &&
!scope->as<StaticEvalObject>().isStrict());
scope = StaticEvalObject::create(cx, NullPtr());
if (!scope)
return false;
}
clone->initScript(nullptr);
JSScript* cscript = CloneScript(cx, scope, clone, script, polluted, newKind);
if (!cscript)
return false;
clone->setScript(cscript);
cscript->setFunction(clone);
script = clone->nonLazyScript();
Debugger::onNewScript(cx, script);
return true;
}
DebugScript*
JSScript::debugScript()
{
MOZ_ASSERT(hasDebugScript_);
DebugScriptMap* map = compartment()->debugScriptMap;
MOZ_ASSERT(map);
DebugScriptMap::Ptr p = map->lookup(this);
MOZ_ASSERT(p);
return p->value();
}
DebugScript*
JSScript::releaseDebugScript()
{
MOZ_ASSERT(hasDebugScript_);
DebugScriptMap* map = compartment()->debugScriptMap;
MOZ_ASSERT(map);
DebugScriptMap::Ptr p = map->lookup(this);
MOZ_ASSERT(p);
DebugScript* debug = p->value();
map->remove(p);
hasDebugScript_ = false;
return debug;
}
void
JSScript::destroyDebugScript(FreeOp* fop)
{
if (hasDebugScript_) {
#ifdef DEBUG
for (jsbytecode* pc = code(); pc < codeEnd(); pc++) {
if (BreakpointSite* site = getBreakpointSite(pc)) {
/* Breakpoints are swept before finalization. */
MOZ_ASSERT(site->firstBreakpoint() == nullptr);
MOZ_ASSERT(getBreakpointSite(pc) == nullptr);
}
}
#endif
fop->free_(releaseDebugScript());
}
}
bool
JSScript::ensureHasDebugScript(JSContext* cx)
{
if (hasDebugScript_)
return true;
size_t nbytes = offsetof(DebugScript, breakpoints) + length() * sizeof(BreakpointSite*);
DebugScript* debug = (DebugScript*) zone()->pod_calloc<uint8_t>(nbytes);
if (!debug)
return false;
/* Create compartment's debugScriptMap if necessary. */
DebugScriptMap* map = compartment()->debugScriptMap;
if (!map) {
map = cx->new_<DebugScriptMap>();
if (!map || !map->init()) {
js_free(debug);
js_delete(map);
return false;
}
compartment()->debugScriptMap = map;
}
if (!map->putNew(this, debug)) {
js_free(debug);
return false;
}
hasDebugScript_ = true; // safe to set this; we can't fail after this point
/*
* Ensure that any Interpret() instances running on this script have
* interrupts enabled. The interrupts must stay enabled until the
* debug state is destroyed.
*/
for (ActivationIterator iter(cx->runtime()); !iter.done(); ++iter) {
if (iter->isInterpreter())
iter->asInterpreter()->enableInterruptsIfRunning(this);
}
return true;
}
void
JSScript::setNewStepMode(FreeOp* fop, uint32_t newValue)
{
DebugScript* debug = debugScript();
uint32_t prior = debug->stepMode;
debug->stepMode = newValue;
if (!prior != !newValue) {
if (hasBaselineScript())
baseline->toggleDebugTraps(this, nullptr);
if (!stepModeEnabled() && !debug->numSites)
fop->free_(releaseDebugScript());
}
}
bool
JSScript::incrementStepModeCount(JSContext* cx)
{
assertSameCompartment(cx, this);
MOZ_ASSERT(cx->compartment()->isDebuggee());
if (!ensureHasDebugScript(cx))
return false;
DebugScript* debug = debugScript();
uint32_t count = debug->stepMode;
setNewStepMode(cx->runtime()->defaultFreeOp(), count + 1);
return true;
}
void
JSScript::decrementStepModeCount(FreeOp* fop)
{
DebugScript* debug = debugScript();
uint32_t count = debug->stepMode;
MOZ_ASSERT(count > 0);
setNewStepMode(fop, count - 1);
}
BreakpointSite*
JSScript::getOrCreateBreakpointSite(JSContext* cx, jsbytecode* pc)
{
if (!ensureHasDebugScript(cx))
return nullptr;
DebugScript* debug = debugScript();
BreakpointSite*& site = debug->breakpoints[pcToOffset(pc)];
if (!site) {
site = cx->runtime()->new_<BreakpointSite>(this, pc);
if (!site) {
ReportOutOfMemory(cx);
return nullptr;
}
debug->numSites++;
}
return site;
}
void
JSScript::destroyBreakpointSite(FreeOp* fop, jsbytecode* pc)
{
DebugScript* debug = debugScript();
BreakpointSite*& site = debug->breakpoints[pcToOffset(pc)];
MOZ_ASSERT(site);
fop->delete_(site);
site = nullptr;
if (--debug->numSites == 0 && !stepModeEnabled())
fop->free_(releaseDebugScript());
}
void
JSScript::clearBreakpointsIn(FreeOp* fop, js::Debugger* dbg, JSObject* handler)
{
if (!hasAnyBreakpointsOrStepMode())
return;
for (jsbytecode* pc = code(); pc < codeEnd(); pc++) {
BreakpointSite* site = getBreakpointSite(pc);
if (site) {
Breakpoint* nextbp;
for (Breakpoint* bp = site->firstBreakpoint(); bp; bp = nextbp) {
nextbp = bp->nextInSite();
if ((!dbg || bp->debugger == dbg) && (!handler || bp->getHandler() == handler))
bp->destroy(fop);
}
}
}
}
bool
JSScript::hasBreakpointsAt(jsbytecode* pc)
{
BreakpointSite* site = getBreakpointSite(pc);
if (!site)
return false;
return site->enabledCount > 0;
}
void
JSScript::markChildren(JSTracer* trc)
{
// NOTE: this JSScript may be partially initialized at this point. E.g. we
// may have created it and partially initialized it with
// JSScript::Create(), but not yet finished initializing it with
// fullyInitFromEmitter() or fullyInitTrivial().
MOZ_ASSERT_IF(trc->isMarkingTracer() &&
static_cast<GCMarker*>(trc)->shouldCheckCompartments(),
zone()->isCollecting());
for (uint32_t i = 0; i < natoms(); ++i) {
if (atoms[i])
MarkString(trc, &atoms[i], "atom");
}
if (hasObjects()) {
ObjectArray* objarray = objects();
MarkObjectRange(trc, objarray->length, objarray->vector, "objects");
}
if (hasRegexps()) {
ObjectArray* objarray = regexps();
MarkObjectRange(trc, objarray->length, objarray->vector, "objects");
}
if (hasConsts()) {
ConstArray* constarray = consts();
MarkValueRange(trc, constarray->length, constarray->vector, "consts");
}
if (sourceObject()) {
MOZ_ASSERT(MaybeForwarded(sourceObject())->compartment() == compartment());
MarkObject(trc, &sourceObject_, "sourceObject");
}
if (functionNonDelazifying())
MarkObject(trc, &function_, "function");
if (enclosingStaticScope_)
MarkObject(trc, &enclosingStaticScope_, "enclosingStaticScope");
if (maybeLazyScript())
MarkLazyScriptUnbarriered(trc, &lazyScript, "lazyScript");
if (trc->isMarkingTracer()) {
compartment()->mark();
if (code())
MarkScriptData(trc->runtime(), code());
}
bindings.trace(trc);
jit::TraceJitScripts(trc, this);
}
void
LazyScript::markChildren(JSTracer* trc)
{
if (function_)
MarkObject(trc, &function_, "function");
if (sourceObject_)
MarkObject(trc, &sourceObject_, "sourceObject");
if (enclosingScope_)
MarkObject(trc, &enclosingScope_, "enclosingScope");
if (script_)
MarkScript(trc, &script_, "realScript");
// We rely on the fact that atoms are always tenured.
FreeVariable* freeVariables = this->freeVariables();
for (size_t i = 0; i < numFreeVariables(); i++) {
JSAtom* atom = freeVariables[i].atom();
MarkStringUnbarriered(trc, &atom, "lazyScriptFreeVariable");
}
HeapPtrFunction* innerFunctions = this->innerFunctions();
for (size_t i = 0; i < numInnerFunctions(); i++)
MarkObject(trc, &innerFunctions[i], "lazyScriptInnerFunction");
}
void
LazyScript::finalize(FreeOp* fop)
{
if (table_)
fop->free_(table_);
}
NestedScopeObject*
JSScript::getStaticBlockScope(jsbytecode* pc)
{
MOZ_ASSERT(containsPC(pc));
if (!hasBlockScopes())
return nullptr;
if (pc < main())
return nullptr;
size_t offset = pc - main();
BlockScopeArray* scopes = blockScopes();
NestedScopeObject* blockChain = nullptr;
// Find the innermost block chain using a binary search.
size_t bottom = 0;
size_t top = scopes->length;
while (bottom < top) {
size_t mid = bottom + (top - bottom) / 2;
const BlockScopeNote* note = &scopes->vector[mid];
if (note->start <= offset) {
// Block scopes are ordered in the list by their starting offset, and since
// blocks form a tree ones earlier in the list may cover the pc even if
// later blocks end before the pc. This only happens when the earlier block
// is a parent of the later block, so we need to check parents of |mid| in
// the searched range for coverage.
size_t check = mid;
while (check >= bottom) {
const BlockScopeNote* checkNote = &scopes->vector[check];
MOZ_ASSERT(checkNote->start <= offset);
if (offset < checkNote->start + checkNote->length) {
// We found a matching block chain but there may be inner ones
// at a higher block chain index than mid. Continue the binary search.
if (checkNote->index == BlockScopeNote::NoBlockScopeIndex)
blockChain = nullptr;
else
blockChain = &getObject(checkNote->index)->as<NestedScopeObject>();
break;
}
if (checkNote->parent == UINT32_MAX)
break;
check = checkNote->parent;
}
bottom = mid + 1;
} else {
top = mid;
}
}
return blockChain;
}
JSObject*
JSScript::innermostStaticScopeInScript(jsbytecode* pc)
{
if (JSObject* scope = getStaticBlockScope(pc))
return scope;
return functionNonDelazifying();
}
JSObject*
JSScript::innermostStaticScope(jsbytecode* pc)
{
if (JSObject* scope = innermostStaticScopeInScript(pc))
return scope;
return enclosingStaticScope();
}
void
JSScript::setArgumentsHasVarBinding()
{
argsHasVarBinding_ = true;
needsArgsAnalysis_ = true;
}
void
JSScript::setNeedsArgsObj(bool needsArgsObj)
{
MOZ_ASSERT_IF(needsArgsObj, argumentsHasVarBinding());
needsArgsAnalysis_ = false;
needsArgsObj_ = needsArgsObj;
}
void
js::SetFrameArgumentsObject(JSContext* cx, AbstractFramePtr frame,
HandleScript script, JSObject* argsobj)
{
/*
* Replace any optimized arguments in the frame with an explicit arguments
* object. Note that 'arguments' may have already been overwritten.
*/
InternalBindingsHandle bindings(script, &script->bindings);
BindingIter bi = Bindings::argumentsBinding(cx, bindings);
if (script->bindingIsAliased(bi)) {
/*
* Scan the script to find the slot in the call object that 'arguments'
* is assigned to.
*/
jsbytecode* pc = script->code();
while (*pc != JSOP_ARGUMENTS)
pc += GetBytecodeLength(pc);
pc += JSOP_ARGUMENTS_LENGTH;
MOZ_ASSERT(*pc == JSOP_SETALIASEDVAR);
// Note that here and below, it is insufficient to only check for
// JS_OPTIMIZED_ARGUMENTS, as Ion could have optimized out the
// arguments slot.
if (IsOptimizedPlaceholderMagicValue(frame.callObj().as<ScopeObject>().aliasedVar(ScopeCoordinate(pc))))
frame.callObj().as<ScopeObject>().setAliasedVar(cx, ScopeCoordinate(pc), cx->names().arguments, ObjectValue(*argsobj));
} else {
if (IsOptimizedPlaceholderMagicValue(frame.unaliasedLocal(bi.frameIndex())))
frame.unaliasedLocal(bi.frameIndex()) = ObjectValue(*argsobj);
}
}
/* static */ bool
JSScript::argumentsOptimizationFailed(JSContext* cx, HandleScript script)
{
MOZ_ASSERT(script->functionNonDelazifying());
MOZ_ASSERT(script->analyzedArgsUsage());
MOZ_ASSERT(script->argumentsHasVarBinding());
/*
* It is possible that the arguments optimization has already failed,
* everything has been fixed up, but there was an outstanding magic value
* on the stack that has just now flowed into an apply. In this case, there
* is nothing to do; GuardFunApplySpeculation will patch in the real
* argsobj.
*/
if (script->needsArgsObj())
return true;
MOZ_ASSERT(!script->isGenerator());
script->needsArgsObj_ = true;
/*
* Since we can't invalidate baseline scripts, set a flag that's checked from
* JIT code to indicate the arguments optimization failed and JSOP_ARGUMENTS
* should create an arguments object next time.
*/
if (script->hasBaselineScript())
script->baselineScript()->setNeedsArgsObj();
/*
* By design, the arguments optimization is only made when there are no
* outstanding cases of MagicValue(JS_OPTIMIZED_ARGUMENTS) at any points
* where the optimization could fail, other than an active invocation of
* 'f.apply(x, arguments)'. Thus, there are no outstanding values of
* MagicValue(JS_OPTIMIZED_ARGUMENTS) on the stack. However, there are
* three things that need fixup:
* - there may be any number of activations of this script that don't have
* an argsObj that now need one.
* - jit code compiled (and possible active on the stack) with the static
* assumption of !script->needsArgsObj();
* - type inference data for the script assuming script->needsArgsObj
*/
for (AllFramesIter i(cx); !i.done(); ++i) {
/*
* We cannot reliably create an arguments object for Ion activations of
* this script. To maintain the invariant that "script->needsArgsObj
* implies fp->hasArgsObj", the Ion bail mechanism will create an
* arguments object right after restoring the BaselineFrame and before
* entering Baseline code (in jit::FinishBailoutToBaseline).
*/
if (i.isIon())
continue;
AbstractFramePtr frame = i.abstractFramePtr();
if (frame.isFunctionFrame() && frame.script() == script) {
ArgumentsObject* argsobj = ArgumentsObject::createExpected(cx, frame);
if (!argsobj) {
/*
* We can't leave stack frames with script->needsArgsObj but no
* arguments object. It is, however, safe to leave frames with
* an arguments object but !script->needsArgsObj.
*/
script->needsArgsObj_ = false;
return false;
}
SetFrameArgumentsObject(cx, frame, script, argsobj);
}
}
return true;
}
bool
JSScript::bindingIsAliased(const BindingIter& bi)
{
return bindings.bindingIsAliased(bi.i_);
}
bool
JSScript::formalIsAliased(unsigned argSlot)
{
MOZ_ASSERT(argSlot < bindings.numArgs());
return bindings.bindingIsAliased(argSlot);
}
bool
JSScript::cookieIsAliased(const frontend::UpvarCookie& cookie)
{
return bindings.bindingIsAliased(bindings.numArgs() + cookie.slot());
}
bool
JSScript::formalLivesInArgumentsObject(unsigned argSlot)
{
return argsObjAliasesFormals() && !formalIsAliased(argSlot);
}
LazyScript::LazyScript(JSFunction* fun, void* table, uint64_t packedFields, uint32_t begin, uint32_t end, uint32_t lineno, uint32_t column)
: script_(nullptr),
function_(fun),
enclosingScope_(nullptr),
sourceObject_(nullptr),
table_(table),
packedFields_(packedFields),
begin_(begin),
end_(end),
lineno_(lineno),
column_(column)
{
MOZ_ASSERT(begin <= end);
}
void
LazyScript::initScript(JSScript* script)
{
MOZ_ASSERT(script && !script_);
script_ = script;
}
void
LazyScript::resetScript()
{
MOZ_ASSERT(script_);
script_ = nullptr;
}
void
LazyScript::setParent(JSObject* enclosingScope, ScriptSourceObject* sourceObject)
{
MOZ_ASSERT(!sourceObject_ && !enclosingScope_);
MOZ_ASSERT_IF(enclosingScope, function_->compartment() == enclosingScope->compartment());
MOZ_ASSERT(function_->compartment() == sourceObject->compartment());
enclosingScope_ = enclosingScope;
sourceObject_ = sourceObject;
}
ScriptSourceObject*
LazyScript::sourceObject() const
{
return sourceObject_ ? &sourceObject_->as<ScriptSourceObject>() : nullptr;
}
ScriptSource*
LazyScript::maybeForwardedScriptSource() const
{
return UncheckedUnwrap(MaybeForwarded(sourceObject()))->as<ScriptSourceObject>().source();
}
/* static */ LazyScript*
LazyScript::CreateRaw(ExclusiveContext* cx, HandleFunction fun,
uint64_t packedFields, uint32_t begin, uint32_t end,
uint32_t lineno, uint32_t column)
{
union {
PackedView p;
uint64_t packed;
};
packed = packedFields;
// Reset runtime flags to obtain a fresh LazyScript.
p.hasBeenCloned = false;
p.treatAsRunOnce = false;
size_t bytes = (p.numFreeVariables * sizeof(FreeVariable))
+ (p.numInnerFunctions * sizeof(HeapPtrFunction));
ScopedJSFreePtr<uint8_t> table(bytes ? fun->zone()->pod_malloc<uint8_t>(bytes) : nullptr);
if (bytes && !table)
return nullptr;
LazyScript* res = Allocate<LazyScript>(cx);
if (!res)
return nullptr;
cx->compartment()->scheduleDelazificationForDebugger();
return new (res) LazyScript(fun, table.forget(), packed, begin, end, lineno, column);
}
/* static */ LazyScript*
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)
{
union {
PackedView p;
uint64_t packedFields;
};
p.version = version;
p.numFreeVariables = numFreeVariables;
p.numInnerFunctions = numInnerFunctions;
p.generatorKindBits = GeneratorKindAsBits(NotGenerator);
p.strict = false;
p.bindingsAccessedDynamically = false;
p.hasDebuggerStatement = false;
p.hasDirectEval = false;
p.directlyInsideEval = false;
p.usesArgumentsApplyAndThis = false;
LazyScript* res = LazyScript::CreateRaw(cx, fun, packedFields, begin, end, lineno, column);
MOZ_ASSERT_IF(res, res->version() == version);
return res;
}
/* static */ LazyScript*
LazyScript::Create(ExclusiveContext* cx, HandleFunction fun,
uint64_t packedFields, uint32_t begin, uint32_t end,
uint32_t lineno, uint32_t column)
{
// Dummy atom which is not a valid property name.
RootedAtom dummyAtom(cx, cx->names().comma);
// Dummy function which is not a valid function as this is the one which is
// holding this lazy script.
HandleFunction dummyFun = fun;
LazyScript* res = LazyScript::CreateRaw(cx, fun, packedFields, begin, end, lineno, column);
if (!res)
return nullptr;
// Fill with dummies, to be GC-safe after the initialization of the free
// variables and inner functions.
size_t i, num;
FreeVariable* variables = res->freeVariables();
for (i = 0, num = res->numFreeVariables(); i < num; i++)
variables[i] = FreeVariable(dummyAtom);
HeapPtrFunction* functions = res->innerFunctions();
for (i = 0, num = res->numInnerFunctions(); i < num; i++)
functions[i].init(dummyFun);
return res;
}
void
LazyScript::initRuntimeFields(uint64_t packedFields)
{
union {
PackedView p;
uint64_t packed;
};
packed = packedFields;
p_.hasBeenCloned = p.hasBeenCloned;
p_.treatAsRunOnce = p.treatAsRunOnce;
}
bool
LazyScript::hasUncompiledEnclosingScript() const
{
// It can happen that we created lazy scripts while compiling an enclosing
// script, but we errored out while compiling that script. When we iterate
// over lazy script in a compartment, we might see lazy scripts that never
// escaped to script and should be ignored.
//
// If the enclosing scope is a function with a null script or has a script
// without code, it was not successfully compiled.
if (!enclosingScope() || !enclosingScope()->is<JSFunction>())
return false;
JSFunction& fun = enclosingScope()->as<JSFunction>();
return !fun.hasScript() || fun.hasUncompiledScript() || !fun.nonLazyScript()->code();
}
uint32_t
LazyScript::staticLevel(JSContext* cx) const
{
for (StaticScopeIter<NoGC> ssi(enclosingScope()); !ssi.done(); ssi++) {
if (ssi.type() == StaticScopeIter<NoGC>::Function)
return ssi.funScript()->staticLevel() + 1;
}
return 1;
}
void
JSScript::updateBaselineOrIonRaw(JSContext* maybecx)
{
if (hasIonScript()) {
if (ion->pendingBuilder()) {
MOZ_ASSERT(maybecx);
baselineOrIonRaw = maybecx->runtime()->jitRuntime()->lazyLinkStub()->raw();
baselineOrIonSkipArgCheck = maybecx->runtime()->jitRuntime()->lazyLinkStub()->raw();
} else {
baselineOrIonRaw = ion->method()->raw();
baselineOrIonSkipArgCheck = ion->method()->raw() + ion->getSkipArgCheckEntryOffset();
}
} else if (hasBaselineScript()) {
baselineOrIonRaw = baseline->method()->raw();
baselineOrIonSkipArgCheck = baseline->method()->raw();
} else {
baselineOrIonRaw = nullptr;
baselineOrIonSkipArgCheck = nullptr;
}
}
bool
JSScript::hasLoops()
{
if (!hasTrynotes())
return false;
JSTryNote* tn = trynotes()->vector;
JSTryNote* tnlimit = tn + trynotes()->length;
for (; tn < tnlimit; tn++) {
if (tn->kind == JSTRY_FOR_IN || tn->kind == JSTRY_LOOP)
return true;
}
return false;
}
static inline void
LazyScriptHash(uint32_t lineno, uint32_t column, uint32_t begin, uint32_t end,
HashNumber hashes[3])
{
HashNumber hash = lineno;
hash = RotateLeft(hash, 4) ^ column;
hash = RotateLeft(hash, 4) ^ begin;
hash = RotateLeft(hash, 4) ^ end;
hashes[0] = hash;
hashes[1] = RotateLeft(hashes[0], 4) ^ begin;
hashes[2] = RotateLeft(hashes[1], 4) ^ end;
}
void
LazyScriptHashPolicy::hash(const Lookup& lookup, HashNumber hashes[3])
{
LazyScript* lazy = lookup.lazy;
LazyScriptHash(lazy->lineno(), lazy->column(), lazy->begin(), lazy->end(), hashes);
}
void
LazyScriptHashPolicy::hash(JSScript* script, HashNumber hashes[3])
{
LazyScriptHash(script->lineno(), script->column(), script->sourceStart(), script->sourceEnd(), hashes);
}
bool
LazyScriptHashPolicy::match(JSScript* script, const Lookup& lookup)
{
JSContext* cx = lookup.cx;
LazyScript* lazy = lookup.lazy;
// To be a match, the script and lazy script need to have the same line
// and column and to be at the same position within their respective
// source blobs, and to have the same source contents and version.
//
// While the surrounding code in the source may differ, this is
// sufficient to ensure that compiling the lazy script will yield an
// identical result to compiling the original script.
//
// Note that the filenames and origin principals of the lazy script and
// original script can differ. If there is a match, these will be fixed
// up in the resulting clone by the caller.
if (script->lineno() != lazy->lineno() ||
script->column() != lazy->column() ||
script->getVersion() != lazy->version() ||
script->sourceStart() != lazy->begin() ||
script->sourceEnd() != lazy->end())
{
return false;
}
UncompressedSourceCache::AutoHoldEntry holder;
const char16_t* scriptChars = script->scriptSource()->chars(cx, holder);
if (!scriptChars)
return false;
const char16_t* lazyChars = lazy->scriptSource()->chars(cx, holder);
if (!lazyChars)
return false;
size_t begin = script->sourceStart();
size_t length = script->sourceEnd() - begin;
return !memcmp(scriptChars + begin, lazyChars + begin, length);
}
