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TypeInference.cpp
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TypeInference.cpp
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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "vm/TypeInference-inl.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/IntegerPrintfMacros.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/Move.h"
#include "mozilla/PodOperations.h"
#include "mozilla/ScopeExit.h"
#include "mozilla/Sprintf.h"
#include <new>
#include "jsapi.h"
#include "builtin/String.h"
#include "gc/HashUtil.h"
#include "jit/BaselineIC.h"
#include "jit/BaselineJIT.h"
#include "jit/CompileInfo.h"
#include "jit/Ion.h"
#include "jit/IonAnalysis.h"
#include "jit/JitRealm.h"
#include "jit/OptimizationTracking.h"
#include "js/MemoryMetrics.h"
#include "js/UniquePtr.h"
#include "vm/HelperThreads.h"
#include "vm/JSContext.h"
#include "vm/JSObject.h"
#include "vm/JSScript.h"
#include "vm/Opcodes.h"
#include "vm/Printer.h"
#include "vm/Shape.h"
#include "vm/Time.h"
#include "gc/Marking-inl.h"
#include "gc/PrivateIterators-inl.h"
#include "vm/JSAtom-inl.h"
#include "vm/JSScript-inl.h"
#include "vm/NativeObject-inl.h"
using namespace js;
using mozilla::DebugOnly;
using mozilla::Maybe;
using mozilla::PodArrayZero;
using mozilla::PodCopy;
using mozilla::PodZero;
using js::jit::JitScript;
#ifdef DEBUG
static inline jsid id___proto__(JSContext* cx) {
return NameToId(cx->names().proto);
}
static inline jsid id_constructor(JSContext* cx) {
return NameToId(cx->names().constructor);
}
static inline jsid id_caller(JSContext* cx) {
return NameToId(cx->names().caller);
}
const char* js::TypeIdStringImpl(jsid id) {
if (JSID_IS_VOID(id)) {
return "(index)";
}
if (JSID_IS_EMPTY(id)) {
return "(new)";
}
if (JSID_IS_SYMBOL(id)) {
return "(symbol)";
}
static char bufs[4][100];
static unsigned which = 0;
which = (which + 1) & 3;
PutEscapedString(bufs[which], 100, JSID_TO_FLAT_STRING(id), 0);
return bufs[which];
}
#endif
/////////////////////////////////////////////////////////////////////
// Logging
/////////////////////////////////////////////////////////////////////
/* static */ const char* TypeSet::NonObjectTypeString(TypeSet::Type type) {
if (type.isPrimitive()) {
switch (type.primitive()) {
case ValueType::Undefined:
return "void";
case ValueType::Null:
return "null";
case ValueType::Boolean:
return "bool";
case ValueType::Int32:
return "int";
case ValueType::Double:
return "float";
case ValueType::String:
return "string";
case ValueType::Symbol:
return "symbol";
case ValueType::BigInt:
return "BigInt";
case ValueType::Magic:
return "lazyargs";
case ValueType::PrivateGCThing:
case ValueType::Object:
MOZ_CRASH("Bad type");
}
}
if (type.isUnknown()) {
return "unknown";
}
MOZ_ASSERT(type.isAnyObject());
return "object";
}
static UniqueChars MakeStringCopy(const char* s) {
AutoEnterOOMUnsafeRegion oomUnsafe;
char* copy = strdup(s);
if (!copy) {
oomUnsafe.crash("Could not copy string");
}
return UniqueChars(copy);
}
/* static */
UniqueChars TypeSet::TypeString(const TypeSet::Type type) {
if (type.isPrimitive() || type.isUnknown() || type.isAnyObject()) {
return MakeStringCopy(NonObjectTypeString(type));
}
char buf[100];
if (type.isSingleton()) {
JSObject* singleton = type.singletonNoBarrier();
SprintfLiteral(buf, "<%s %#" PRIxPTR ">", singleton->getClass()->name,
uintptr_t(singleton));
} else {
SprintfLiteral(buf, "[%s * %#" PRIxPTR "]",
type.groupNoBarrier()->clasp()->name,
uintptr_t(type.groupNoBarrier()));
}
return MakeStringCopy(buf);
}
/* static */
UniqueChars TypeSet::ObjectGroupString(const ObjectGroup* group) {
return TypeString(TypeSet::ObjectType(group));
}
#ifdef DEBUG
bool js::InferSpewActive(TypeSpewChannel channel) {
static bool active[SPEW_COUNT];
static bool checked = false;
if (!checked) {
checked = true;
PodArrayZero(active);
if (mozilla::recordreplay::IsRecordingOrReplaying()) {
return false;
}
const char* env = getenv("INFERFLAGS");
if (!env) {
return false;
}
if (strstr(env, "ops")) {
active[ISpewOps] = true;
}
if (strstr(env, "result")) {
active[ISpewResult] = true;
}
if (strstr(env, "full")) {
for (unsigned i = 0; i < SPEW_COUNT; i++) {
active[i] = true;
}
}
}
return active[channel];
}
static bool InferSpewColorable() {
/* Only spew colors on xterm-color to not screw up emacs. */
static bool colorable = false;
static bool checked = false;
if (!checked) {
checked = true;
if (mozilla::recordreplay::IsRecordingOrReplaying()) {
return false;
}
const char* env = getenv("TERM");
if (!env) {
return false;
}
if (strcmp(env, "xterm-color") == 0 || strcmp(env, "xterm-256color") == 0) {
colorable = true;
}
}
return colorable;
}
const char* js::InferSpewColorReset() {
if (!InferSpewColorable()) {
return "";
}
return "\x1b[0m";
}
const char* js::InferSpewColor(TypeConstraint* constraint) {
/* Type constraints are printed out using foreground colors. */
static const char* const colors[] = {"\x1b[31m", "\x1b[32m", "\x1b[33m",
"\x1b[34m", "\x1b[35m", "\x1b[36m",
"\x1b[37m"};
if (!InferSpewColorable()) {
return "";
}
return colors[DefaultHasher<TypeConstraint*>::hash(constraint) % 7];
}
const char* js::InferSpewColor(TypeSet* types) {
/* Type sets are printed out using bold colors. */
static const char* const colors[] = {"\x1b[1;31m", "\x1b[1;32m", "\x1b[1;33m",
"\x1b[1;34m", "\x1b[1;35m", "\x1b[1;36m",
"\x1b[1;37m"};
if (!InferSpewColorable()) {
return "";
}
return colors[DefaultHasher<TypeSet*>::hash(types) % 7];
}
# ifdef DEBUG
void js::InferSpewImpl(const char* fmt, ...) {
va_list ap;
va_start(ap, fmt);
fprintf(stderr, "[infer] ");
vfprintf(stderr, fmt, ap);
fprintf(stderr, "\n");
va_end(ap);
}
# endif
MOZ_NORETURN MOZ_COLD static void MOZ_FORMAT_PRINTF(2, 3)
TypeFailure(JSContext* cx, const char* fmt, ...) {
char msgbuf[1024]; /* Larger error messages will be truncated */
char errbuf[1024];
va_list ap;
va_start(ap, fmt);
VsprintfLiteral(errbuf, fmt, ap);
va_end(ap);
SprintfLiteral(msgbuf, "[infer failure] %s", errbuf);
/* Dump type state, even if INFERFLAGS is unset. */
PrintTypes(cx, cx->compartment(), true);
MOZ_ReportAssertionFailure(msgbuf, __FILE__, __LINE__);
MOZ_CRASH();
}
bool js::ObjectGroupHasProperty(JSContext* cx, ObjectGroup* group, jsid id,
const Value& value) {
/*
* Check the correctness of the type information in the object's property
* against an actual value.
*/
AutoSweepObjectGroup sweep(group);
if (!group->unknownProperties(sweep) && !value.isUndefined()) {
id = IdToTypeId(id);
/* Watch for properties which inference does not monitor. */
if (id == id___proto__(cx) || id == id_constructor(cx) ||
id == id_caller(cx)) {
return true;
}
TypeSet::Type type = TypeSet::GetValueType(value);
AutoEnterAnalysis enter(cx);
/*
* We don't track types for properties inherited from prototypes which
* haven't yet been accessed during analysis of the inheriting object.
* Don't do the property instantiation now.
*/
TypeSet* types = group->maybeGetProperty(sweep, id);
if (!types) {
return true;
}
// Type set guards might miss when an object's group changes and its
// properties become unknown.
if (value.isObject()) {
if (types->unknownObject()) {
return true;
}
for (size_t i = 0; i < types->getObjectCount(); i++) {
if (TypeSet::ObjectKey* key = types->getObject(i)) {
if (key->unknownProperties()) {
return true;
}
}
}
}
if (!types->hasType(type)) {
TypeFailure(cx, "Missing type in object %s %s: %s",
TypeSet::ObjectGroupString(group).get(), TypeIdString(id),
TypeSet::TypeString(type).get());
}
}
return true;
}
#endif
/////////////////////////////////////////////////////////////////////
// TypeSet
/////////////////////////////////////////////////////////////////////
TemporaryTypeSet::TemporaryTypeSet(LifoAlloc* alloc, Type type) {
if (type.isUnknown()) {
flags |= TYPE_FLAG_BASE_MASK;
return;
}
if (type.isPrimitive()) {
flags = PrimitiveTypeFlag(type.primitive());
if (flags == TYPE_FLAG_DOUBLE) {
flags |= TYPE_FLAG_INT32;
}
return;
}
if (type.isAnyObject()) {
flags |= TYPE_FLAG_ANYOBJECT;
return;
}
if (type.isGroup()) {
AutoSweepObjectGroup sweep(type.group());
if (type.group()->unknownProperties(sweep)) {
flags |= TYPE_FLAG_ANYOBJECT;
return;
}
}
setBaseObjectCount(1);
objectSet = reinterpret_cast<ObjectKey**>(type.objectKey());
if (type.isGroup()) {
ObjectGroup* ngroup = type.group();
AutoSweepObjectGroup sweep(ngroup);
if (ngroup->newScript(sweep) &&
ngroup->newScript(sweep)->initializedGroup()) {
addType(ObjectType(ngroup->newScript(sweep)->initializedGroup()), alloc);
}
}
}
bool TypeSet::mightBeMIRType(jit::MIRType type) const {
if (unknown()) {
return true;
}
if (type == jit::MIRType::Object) {
return unknownObject() || baseObjectCount() != 0;
}
switch (type) {
case jit::MIRType::Undefined:
return baseFlags() & TYPE_FLAG_UNDEFINED;
case jit::MIRType::Null:
return baseFlags() & TYPE_FLAG_NULL;
case jit::MIRType::Boolean:
return baseFlags() & TYPE_FLAG_BOOLEAN;
case jit::MIRType::Int32:
return baseFlags() & TYPE_FLAG_INT32;
case jit::MIRType::Float32: // Fall through, there's no JSVAL for Float32.
case jit::MIRType::Double:
return baseFlags() & TYPE_FLAG_DOUBLE;
case jit::MIRType::String:
return baseFlags() & TYPE_FLAG_STRING;
case jit::MIRType::Symbol:
return baseFlags() & TYPE_FLAG_SYMBOL;
case jit::MIRType::BigInt:
return baseFlags() & TYPE_FLAG_BIGINT;
case jit::MIRType::MagicOptimizedArguments:
return baseFlags() & TYPE_FLAG_LAZYARGS;
case jit::MIRType::MagicHole:
case jit::MIRType::MagicIsConstructing:
// These magic constants do not escape to script and are not observed
// in the type sets.
//
// The reason we can return false here is subtle: if Ion is asking the
// type set if it has seen such a magic constant, then the MIR in
// question is the most generic type, MIRType::Value. A magic constant
// could only be emitted by a MIR of MIRType::Value if that MIR is a
// phi, and we check that different magic constants do not flow to the
// same join point in GuessPhiType.
return false;
default:
MOZ_CRASH("Bad MIR type");
}
}
bool TypeSet::objectsAreSubset(TypeSet* other) {
if (other->unknownObject()) {
return true;
}
if (unknownObject()) {
return false;
}
for (unsigned i = 0; i < getObjectCount(); i++) {
ObjectKey* key = getObject(i);
if (!key) {
continue;
}
if (!other->hasType(ObjectType(key))) {
return false;
}
}
return true;
}
bool TypeSet::isSubset(const TypeSet* other) const {
if ((baseFlags() & other->baseFlags()) != baseFlags()) {
return false;
}
if (unknownObject()) {
MOZ_ASSERT(other->unknownObject());
} else {
for (unsigned i = 0; i < getObjectCount(); i++) {
ObjectKey* key = getObject(i);
if (!key) {
continue;
}
if (!other->hasType(ObjectType(key))) {
return false;
}
}
}
return true;
}
bool TypeSet::objectsIntersect(const TypeSet* other) const {
if (unknownObject() || other->unknownObject()) {
return true;
}
for (unsigned i = 0; i < getObjectCount(); i++) {
ObjectKey* key = getObject(i);
if (!key) {
continue;
}
if (other->hasType(ObjectType(key))) {
return true;
}
}
return false;
}
template <class TypeListT>
bool TypeSet::enumerateTypes(TypeListT* list) const {
/* If any type is possible, there's no need to worry about specifics. */
if (flags & TYPE_FLAG_UNKNOWN) {
return list->append(UnknownType());
}
/* Enqueue type set members stored as bits. */
for (TypeFlags flag = 1; flag < TYPE_FLAG_ANYOBJECT; flag <<= 1) {
if (flags & flag) {
Type type = PrimitiveType(TypeFlagPrimitive(flag));
if (!list->append(type)) {
return false;
}
}
}
/* If any object is possible, skip specifics. */
if (flags & TYPE_FLAG_ANYOBJECT) {
return list->append(AnyObjectType());
}
/* Enqueue specific object types. */
unsigned count = getObjectCount();
for (unsigned i = 0; i < count; i++) {
ObjectKey* key = getObject(i);
if (key) {
if (!list->append(ObjectType(key))) {
return false;
}
}
}
return true;
}
template bool TypeSet::enumerateTypes<TypeSet::TypeList>(TypeList* list) const;
template bool TypeSet::enumerateTypes<jit::TempTypeList>(
jit::TempTypeList* list) const;
inline bool TypeSet::addTypesToConstraint(JSContext* cx,
TypeConstraint* constraint) {
/*
* Build all types in the set into a vector before triggering the
* constraint, as doing so may modify this type set.
*/
TypeList types;
if (!enumerateTypes(&types)) {
return false;
}
for (unsigned i = 0; i < types.length(); i++) {
constraint->newType(cx, this, types[i]);
}
return true;
}
#ifdef DEBUG
static inline bool CompartmentsMatch(Compartment* a, Compartment* b) {
return !a || !b || a == b;
}
#endif
bool ConstraintTypeSet::addConstraint(JSContext* cx, TypeConstraint* constraint,
bool callExisting) {
checkMagic();
if (!constraint) {
/* OOM failure while constructing the constraint. */
return false;
}
MOZ_RELEASE_ASSERT(cx->zone()->types.activeAnalysis);
MOZ_ASSERT(
CompartmentsMatch(maybeCompartment(), constraint->maybeCompartment()));
InferSpew(ISpewOps, "addConstraint: %sT%p%s %sC%p%s %s", InferSpewColor(this),
this, InferSpewColorReset(), InferSpewColor(constraint), constraint,
InferSpewColorReset(), constraint->kind());
MOZ_ASSERT(constraint->next() == nullptr);
constraint->setNext(constraintList_);
constraintList_ = constraint;
if (callExisting) {
return addTypesToConstraint(cx, constraint);
}
return true;
}
void TypeSet::clearObjects() {
setBaseObjectCount(0);
objectSet = nullptr;
}
Compartment* TypeSet::maybeCompartment() {
if (unknownObject()) {
return nullptr;
}
unsigned objectCount = getObjectCount();
for (unsigned i = 0; i < objectCount; i++) {
ObjectKey* key = getObject(i);
if (!key) {
continue;
}
Compartment* comp = key->maybeCompartment();
if (comp) {
return comp;
}
}
return nullptr;
}
void TypeSet::addType(Type type, LifoAlloc* alloc) {
MOZ_ASSERT(CompartmentsMatch(maybeCompartment(), type.maybeCompartment()));
if (unknown()) {
return;
}
if (type.isUnknown()) {
flags |= TYPE_FLAG_BASE_MASK;
clearObjects();
MOZ_ASSERT(unknown());
return;
}
if (type.isPrimitive()) {
TypeFlags flag = PrimitiveTypeFlag(type.primitive());
if (flags & flag) {
return;
}
/* If we add float to a type set it is also considered to contain int. */
if (flag == TYPE_FLAG_DOUBLE) {
flag |= TYPE_FLAG_INT32;
}
flags |= flag;
return;
}
if (flags & TYPE_FLAG_ANYOBJECT) {
return;
}
if (type.isAnyObject()) {
goto unknownObject;
}
{
uint32_t objectCount = baseObjectCount();
ObjectKey* key = type.objectKey();
ObjectKey** pentry = TypeHashSet::Insert<ObjectKey*, ObjectKey, ObjectKey>(
*alloc, objectSet, objectCount, key);
if (!pentry) {
goto unknownObject;
}
if (*pentry) {
return;
}
*pentry = key;
setBaseObjectCount(objectCount);
// Limit the number of objects we track. There is a different limit
// depending on whether the set only contains DOM objects, which can
// have many different classes and prototypes but are still optimizable
// by IonMonkey.
if (objectCount >= TYPE_FLAG_OBJECT_COUNT_LIMIT) {
JS_STATIC_ASSERT(TYPE_FLAG_DOMOBJECT_COUNT_LIMIT >=
TYPE_FLAG_OBJECT_COUNT_LIMIT);
// Examining the entire type set is only required when we first hit
// the normal object limit.
if (objectCount == TYPE_FLAG_OBJECT_COUNT_LIMIT) {
for (unsigned i = 0; i < objectCount; i++) {
const Class* clasp = getObjectClass(i);
if (clasp && !clasp->isDOMClass()) {
goto unknownObject;
}
}
}
// Make sure the newly added object is also a DOM object.
if (!key->clasp()->isDOMClass()) {
goto unknownObject;
}
// Limit the number of DOM objects.
if (objectCount == TYPE_FLAG_DOMOBJECT_COUNT_LIMIT) {
goto unknownObject;
}
}
}
if (type.isGroup()) {
ObjectGroup* ngroup = type.group();
MOZ_ASSERT(!ngroup->singleton());
AutoSweepObjectGroup sweep(ngroup);
if (ngroup->unknownProperties(sweep)) {
goto unknownObject;
}
// If we add a partially initialized group to a type set, add the
// corresponding fully initialized group, as an object's group may change
// from the former to the latter via the acquired properties analysis.
if (ngroup->newScript(sweep) &&
ngroup->newScript(sweep)->initializedGroup()) {
addType(ObjectType(ngroup->newScript(sweep)->initializedGroup()), alloc);
}
}
if (false) {
unknownObject:
flags |= TYPE_FLAG_ANYOBJECT;
clearObjects();
}
}
// This class is used for post barriers on type set contents. The only times
// when type sets contain nursery references is when a nursery object has its
// group dynamically changed to a singleton. In such cases the type set will
// need to be traced at the next minor GC.
//
// There is no barrier used for TemporaryTypeSets. These type sets are only
// used during Ion compilation, and if some ConstraintTypeSet contains nursery
// pointers then any number of TemporaryTypeSets might as well. Thus, if there
// are any such ConstraintTypeSets in existence, all off thread Ion
// compilations are canceled by the next minor GC.
class TypeSetRef : public gc::BufferableRef {
Zone* zone;
ConstraintTypeSet* types;
#ifdef DEBUG
uint64_t minorGCNumberAtCreation;
#endif
public:
TypeSetRef(Zone* zone, ConstraintTypeSet* types)
: zone(zone),
types(types)
#ifdef DEBUG
,
minorGCNumberAtCreation(
zone->runtimeFromMainThread()->gc.minorGCCount())
#endif
{
}
void trace(JSTracer* trc) override {
MOZ_ASSERT(trc->runtime()->gc.minorGCCount() == minorGCNumberAtCreation);
types->trace(zone, trc);
}
};
void ConstraintTypeSet::postWriteBarrier(JSContext* cx, Type type) {
if (type.isSingletonUnchecked()) {
if (gc::StoreBuffer* sb = type.singletonNoBarrier()->storeBuffer()) {
sb->putGeneric(TypeSetRef(cx->zone(), this));
sb->setShouldCancelIonCompilations();
}
}
}
void ConstraintTypeSet::addType(const AutoSweepBase& sweep, JSContext* cx,
Type type) {
checkMagic();
MOZ_RELEASE_ASSERT(cx->zone()->types.activeAnalysis);
if (hasType(type)) {
return;
}
TypeSet::addType(type, &cx->typeLifoAlloc());
if (type.isObjectUnchecked() && unknownObject()) {
type = AnyObjectType();
}
postWriteBarrier(cx, type);
InferSpew(ISpewOps, "addType: %sT%p%s %s", InferSpewColor(this), this,
InferSpewColorReset(), TypeString(type).get());
/* Propagate the type to all constraints. */
if (!cx->isHelperThreadContext()) {
TypeConstraint* constraint = constraintList(sweep);
while (constraint) {
constraint->newType(cx, this, type);
constraint = constraint->next();
}
} else {
MOZ_ASSERT(!constraintList_);
}
}
void TypeSet::print(FILE* fp) {
bool fromDebugger = !fp;
if (!fp) {
fp = stderr;
}
if (flags & TYPE_FLAG_NON_DATA_PROPERTY) {
fprintf(fp, " [non-data]");
}
if (flags & TYPE_FLAG_NON_WRITABLE_PROPERTY) {
fprintf(fp, " [non-writable]");
}
if (definiteProperty()) {
fprintf(fp, " [definite:%d]", definiteSlot());
}
if (baseFlags() == 0 && !baseObjectCount()) {
fprintf(fp, " missing");
return;
}
if (flags & TYPE_FLAG_UNKNOWN) {
fprintf(fp, " unknown");
}
if (flags & TYPE_FLAG_ANYOBJECT) {
fprintf(fp, " object");
}
if (flags & TYPE_FLAG_UNDEFINED) {
fprintf(fp, " void");
}
if (flags & TYPE_FLAG_NULL) {
fprintf(fp, " null");
}
if (flags & TYPE_FLAG_BOOLEAN) {
fprintf(fp, " bool");
}
if (flags & TYPE_FLAG_INT32) {
fprintf(fp, " int");
}
if (flags & TYPE_FLAG_DOUBLE) {
fprintf(fp, " float");
}
if (flags & TYPE_FLAG_STRING) {
fprintf(fp, " string");
}
if (flags & TYPE_FLAG_SYMBOL) {
fprintf(fp, " symbol");
}
if (flags & TYPE_FLAG_BIGINT) {
fprintf(fp, " BigInt");
}
if (flags & TYPE_FLAG_LAZYARGS) {
fprintf(fp, " lazyargs");
}
uint32_t objectCount = baseObjectCount();
if (objectCount) {
fprintf(fp, " object[%u]", objectCount);
unsigned count = getObjectCount();
for (unsigned i = 0; i < count; i++) {
ObjectKey* key = getObject(i);
if (key) {
fprintf(fp, " %s", TypeString(ObjectType(key)).get());
}
}
}
if (fromDebugger) {
fprintf(fp, "\n");
}
}
/* static */
void TypeSet::readBarrier(const TypeSet* types) {
if (types->unknownObject()) {
return;
}
for (unsigned i = 0; i < types->getObjectCount(); i++) {
if (ObjectKey* key = types->getObject(i)) {
if (key->isSingleton()) {
(void)key->singleton();
} else {
(void)key->group();
}
}
}
}
/* static */
bool TypeSet::IsTypeMarked(JSRuntime* rt, TypeSet::Type* v) {
bool rv;
if (v->isSingletonUnchecked()) {
JSObject* obj = v->singletonNoBarrier();
rv = IsMarkedUnbarriered(rt, &obj);
*v = TypeSet::ObjectType(obj);
} else if (v->isGroupUnchecked()) {
ObjectGroup* group = v->groupNoBarrier();
rv = IsMarkedUnbarriered(rt, &group);
*v = TypeSet::ObjectType(group);
} else {
rv = true;
}
return rv;
}
static inline bool IsObjectKeyAboutToBeFinalized(TypeSet::ObjectKey** keyp) {
TypeSet::ObjectKey* key = *keyp;
bool isAboutToBeFinalized;
if (key->isGroup()) {
ObjectGroup* group = key->groupNoBarrier();
isAboutToBeFinalized = IsAboutToBeFinalizedUnbarriered(&group);
if (!isAboutToBeFinalized) {
*keyp = TypeSet::ObjectKey::get(group);
}
} else {
MOZ_ASSERT(key->isSingleton());
JSObject* singleton = key->singletonNoBarrier();
isAboutToBeFinalized = IsAboutToBeFinalizedUnbarriered(&singleton);
if (!isAboutToBeFinalized) {
*keyp = TypeSet::ObjectKey::get(singleton);
}
}
return isAboutToBeFinalized;
}
bool TypeSet::IsTypeAboutToBeFinalized(TypeSet::Type* v) {
bool isAboutToBeFinalized;
if (v->isObjectUnchecked()) {
TypeSet::ObjectKey* key = v->objectKey();
isAboutToBeFinalized = IsObjectKeyAboutToBeFinalized(&key);
if (!isAboutToBeFinalized) {
*v = TypeSet::ObjectType(key);
}
} else {
isAboutToBeFinalized = false;
}
return isAboutToBeFinalized;
}
bool TypeSet::cloneIntoUninitialized(LifoAlloc* alloc,
TemporaryTypeSet* result) const {
unsigned objectCount = baseObjectCount();
unsigned capacity =
(objectCount >= 2) ? TypeHashSet::Capacity(objectCount) : 0;
ObjectKey** newSet;
if (capacity) {
// We allocate an extra word right before the array that stores the
// capacity, so make sure we clone that as well.
newSet = alloc->newArray<ObjectKey*>(capacity + 1);
if (!newSet) {
return false;
}
newSet++;
PodCopy(newSet - 1, objectSet - 1, capacity + 1);
}
new (result) TemporaryTypeSet(flags, capacity ? newSet : objectSet);
return true;
}
TemporaryTypeSet* TypeSet::clone(LifoAlloc* alloc) const {
TemporaryTypeSet* res = alloc->pod_malloc<TemporaryTypeSet>();
if (!res || !cloneIntoUninitialized(alloc, res)) {
return nullptr;
}
return res;
}
TemporaryTypeSet* TypeSet::cloneObjectsOnly(LifoAlloc* alloc) {
TemporaryTypeSet* res = clone(alloc);
if (!res) {
return nullptr;
}
res->flags &= ~TYPE_FLAG_BASE_MASK | TYPE_FLAG_ANYOBJECT;
return res;
}
TemporaryTypeSet* TypeSet::cloneWithoutObjects(LifoAlloc* alloc) {
TemporaryTypeSet* res = alloc->new_<TemporaryTypeSet>();
if (!res) {
return nullptr;
}
res->flags = flags & ~TYPE_FLAG_ANYOBJECT;
res->setBaseObjectCount(0);
return res;
}
/* static */
TemporaryTypeSet* TypeSet::unionSets(TypeSet* a, TypeSet* b, LifoAlloc* alloc) {
TemporaryTypeSet* res = alloc->new_<TemporaryTypeSet>(
a->baseFlags() | b->baseFlags(), static_cast<ObjectKey**>(nullptr));
if (!res) {
return nullptr;
}
if (!res->unknownObject()) {
for (size_t i = 0; i < a->getObjectCount() && !res->unknownObject(); i++) {
if (ObjectKey* key = a->getObject(i)) {
res->addType(ObjectType(key), alloc);
}
}
for (size_t i = 0; i < b->getObjectCount() && !res->unknownObject(); i++) {
if (ObjectKey* key = b->getObject(i)) {
res->addType(ObjectType(key), alloc);
}
}
}
return res;
}
/* static */
TemporaryTypeSet* TypeSet::removeSet(TemporaryTypeSet* input,
TemporaryTypeSet* removal,
LifoAlloc* alloc) {
// Only allow removal of primitives and the "AnyObject" flag.
MOZ_ASSERT(!removal->unknown());
MOZ_ASSERT_IF(!removal->unknownObject(), removal->getObjectCount() == 0);