diff -r 000000000000 -r 6474c204b198 js/src/jsinfer.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jsinfer.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,1657 @@
+/* -*- 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/. */
+
+/* Definitions related to javascript type inference. */
+
+#ifndef jsinfer_h
+#define jsinfer_h
+
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/TypedEnum.h"
+
+#include "jsalloc.h"
+#include "jsfriendapi.h"
+#include "jstypes.h"
+
+#include "ds/IdValuePair.h"
+#include "ds/LifoAlloc.h"
+#include "gc/Barrier.h"
+#include "gc/Marking.h"
+#include "jit/IonTypes.h"
+#include "js/Utility.h"
+#include "js/Vector.h"
+
+namespace js {
+
+class TypeDescr;
+
+class TaggedProto
+{
+  public:
+    static JSObject * const LazyProto;
+
+    TaggedProto() : proto(nullptr) {}
+    TaggedProto(JSObject *proto) : proto(proto) {}
+
+    uintptr_t toWord() const { return uintptr_t(proto); }
+
+    bool isLazy() const {
+        return proto == LazyProto;
+    }
+    bool isObject() const {
+        /* Skip nullptr and LazyProto. */
+        return uintptr_t(proto) > uintptr_t(TaggedProto::LazyProto);
+    }
+    JSObject *toObject() const {
+        JS_ASSERT(isObject());
+        return proto;
+    }
+    JSObject *toObjectOrNull() const {
+        JS_ASSERT(!proto || isObject());
+        return proto;
+    }
+    JSObject *raw() const { return proto; }
+
+    bool operator ==(const TaggedProto &other) { return proto == other.proto; }
+    bool operator !=(const TaggedProto &other) { return proto != other.proto; }
+
+  private:
+    JSObject *proto;
+};
+
+template <>
+struct RootKind<TaggedProto>
+{
+    static ThingRootKind rootKind() { return THING_ROOT_OBJECT; }
+};
+
+template <> struct GCMethods<const TaggedProto>
+{
+    static TaggedProto initial() { return TaggedProto(); }
+    static ThingRootKind kind() { return THING_ROOT_OBJECT; }
+    static bool poisoned(const TaggedProto &v) { return IsPoisonedPtr(v.raw()); }
+};
+
+template <> struct GCMethods<TaggedProto>
+{
+    static TaggedProto initial() { return TaggedProto(); }
+    static ThingRootKind kind() { return THING_ROOT_OBJECT; }
+    static bool poisoned(const TaggedProto &v) { return IsPoisonedPtr(v.raw()); }
+};
+
+template<class Outer>
+class TaggedProtoOperations
+{
+    const TaggedProto *value() const {
+        return static_cast<const Outer*>(this)->extract();
+    }
+
+  public:
+    uintptr_t toWord() const { return value()->toWord(); }
+    inline bool isLazy() const { return value()->isLazy(); }
+    inline bool isObject() const { return value()->isObject(); }
+    inline JSObject *toObject() const { return value()->toObject(); }
+    inline JSObject *toObjectOrNull() const { return value()->toObjectOrNull(); }
+    JSObject *raw() const { return value()->raw(); }
+};
+
+template <>
+class HandleBase<TaggedProto> : public TaggedProtoOperations<Handle<TaggedProto> >
+{
+    friend class TaggedProtoOperations<Handle<TaggedProto> >;
+    const TaggedProto * extract() const {
+        return static_cast<const Handle<TaggedProto>*>(this)->address();
+    }
+};
+
+template <>
+class RootedBase<TaggedProto> : public TaggedProtoOperations<Rooted<TaggedProto> >
+{
+    friend class TaggedProtoOperations<Rooted<TaggedProto> >;
+    const TaggedProto *extract() const {
+        return static_cast<const Rooted<TaggedProto> *>(this)->address();
+    }
+};
+
+class CallObject;
+
+/*
+ * Execution Mode Overview
+ *
+ * JavaScript code can execute either sequentially or in parallel, such as in
+ * PJS. Functions which behave identically in either execution mode can take a
+ * ThreadSafeContext, and functions which have similar but not identical
+ * behavior between execution modes can be templated on the mode. Such
+ * functions use a context parameter type from ExecutionModeTraits below
+ * indicating whether they are only permitted constrained operations (such as
+ * thread safety, and side effects limited to being thread-local), or whether
+ * they can have arbitrary side effects.
+ */
+
+enum ExecutionMode {
+    /* Normal JavaScript execution. */
+    SequentialExecution,
+
+    /*
+     * JavaScript code to be executed in parallel worker threads in PJS in a
+     * fork join fashion.
+     */
+    ParallelExecution,
+
+    /*
+     * Modes after this point are internal and are not counted in
+     * NumExecutionModes below.
+     */
+
+    /*
+     * MIR analysis performed when invoking 'new' on a script, to determine
+     * definite properties. Used by the optimizing JIT.
+     */
+    DefinitePropertiesAnalysis,
+
+    /*
+     * MIR analysis performed when executing a script which uses its arguments,
+     * when it is not known whether a lazy arguments value can be used.
+     */
+    ArgumentsUsageAnalysis
+};
+
+/*
+ * Not as part of the enum so we don't get warnings about unhandled enum
+ * values.
+ */
+static const unsigned NumExecutionModes = ParallelExecution + 1;
+
+template <ExecutionMode mode>
+struct ExecutionModeTraits
+{
+};
+
+template <> struct ExecutionModeTraits<SequentialExecution>
+{
+    typedef JSContext * ContextType;
+    typedef ExclusiveContext * ExclusiveContextType;
+
+    static inline JSContext *toContextType(ExclusiveContext *cx);
+};
+
+template <> struct ExecutionModeTraits<ParallelExecution>
+{
+    typedef ForkJoinContext * ContextType;
+    typedef ForkJoinContext * ExclusiveContextType;
+
+    static inline ForkJoinContext *toContextType(ForkJoinContext *cx) { return cx; }
+};
+
+namespace jit {
+    struct IonScript;
+    class IonAllocPolicy;
+    class TempAllocator;
+}
+
+namespace types {
+
+class TypeZone;
+class TypeSet;
+class TypeObjectKey;
+
+/*
+ * Information about a single concrete type. We pack this into a single word,
+ * where small values are particular primitive or other singleton types, and
+ * larger values are either specific JS objects or type objects.
+ */
+class Type
+{
+    uintptr_t data;
+    Type(uintptr_t data) : data(data) {}
+
+  public:
+
+    uintptr_t raw() const { return data; }
+
+    bool isPrimitive() const {
+        return data < JSVAL_TYPE_OBJECT;
+    }
+
+    bool isPrimitive(JSValueType type) const {
+        JS_ASSERT(type < JSVAL_TYPE_OBJECT);
+        return (uintptr_t) type == data;
+    }
+
+    JSValueType primitive() const {
+        JS_ASSERT(isPrimitive());
+        return (JSValueType) data;
+    }
+
+    bool isMagicArguments() const {
+        return primitive() == JSVAL_TYPE_MAGIC;
+    }
+
+    bool isSomeObject() const {
+        return data == JSVAL_TYPE_OBJECT || data > JSVAL_TYPE_UNKNOWN;
+    }
+
+    bool isAnyObject() const {
+        return data == JSVAL_TYPE_OBJECT;
+    }
+
+    bool isUnknown() const {
+        return data == JSVAL_TYPE_UNKNOWN;
+    }
+
+    /* Accessors for types that are either JSObject or TypeObject. */
+
+    bool isObject() const {
+        JS_ASSERT(!isAnyObject() && !isUnknown());
+        return data > JSVAL_TYPE_UNKNOWN;
+    }
+
+    bool isObjectUnchecked() const {
+        return data > JSVAL_TYPE_UNKNOWN;
+    }
+
+    inline TypeObjectKey *objectKey() const;
+
+    /* Accessors for JSObject types */
+
+    bool isSingleObject() const {
+        return isObject() && !!(data & 1);
+    }
+
+    inline JSObject *singleObject() const;
+
+    /* Accessors for TypeObject types */
+
+    bool isTypeObject() const {
+        return isObject() && !(data & 1);
+    }
+
+    inline TypeObject *typeObject() const;
+
+    bool operator == (Type o) const { return data == o.data; }
+    bool operator != (Type o) const { return data != o.data; }
+
+    static inline Type UndefinedType() { return Type(JSVAL_TYPE_UNDEFINED); }
+    static inline Type NullType()      { return Type(JSVAL_TYPE_NULL); }
+    static inline Type BooleanType()   { return Type(JSVAL_TYPE_BOOLEAN); }
+    static inline Type Int32Type()     { return Type(JSVAL_TYPE_INT32); }
+    static inline Type DoubleType()    { return Type(JSVAL_TYPE_DOUBLE); }
+    static inline Type StringType()    { return Type(JSVAL_TYPE_STRING); }
+    static inline Type MagicArgType()  { return Type(JSVAL_TYPE_MAGIC); }
+    static inline Type AnyObjectType() { return Type(JSVAL_TYPE_OBJECT); }
+    static inline Type UnknownType()   { return Type(JSVAL_TYPE_UNKNOWN); }
+
+    static inline Type PrimitiveType(JSValueType type) {
+        JS_ASSERT(type < JSVAL_TYPE_UNKNOWN);
+        return Type(type);
+    }
+
+    static inline Type ObjectType(JSObject *obj);
+    static inline Type ObjectType(TypeObject *obj);
+    static inline Type ObjectType(TypeObjectKey *obj);
+};
+
+/* Get the type of a jsval, or zero for an unknown special value. */
+inline Type GetValueType(const Value &val);
+
+/*
+ * Get the type of a possibly optimized out value. This generally only
+ * happens on unconditional type monitors on bailing out of Ion, such as
+ * for argument and local types.
+ */
+inline Type GetMaybeOptimizedOutValueType(const Value &val);
+
+/*
+ * Type inference memory management overview.
+ *
+ * Type information about the values observed within scripts and about the
+ * contents of the heap is accumulated as the program executes. Compilation
+ * accumulates constraints relating type information on the heap with the
+ * compilations that should be invalidated when those types change. Type
+ * information and constraints are allocated in the zone's typeLifoAlloc,
+ * and on GC all data referring to live things is copied into a new allocator.
+ * Thus, type set and constraints only hold weak references.
+ */
+
+/*
+ * A constraint which listens to additions to a type set and propagates those
+ * changes to other type sets.
+ */
+class TypeConstraint
+{
+public:
+    /* Next constraint listening to the same type set. */
+    TypeConstraint *next;
+
+    TypeConstraint()
+        : next(nullptr)
+    {}
+
+    /* Debugging name for this kind of constraint. */
+    virtual const char *kind() = 0;
+
+    /* Register a new type for the set this constraint is listening to. */
+    virtual void newType(JSContext *cx, TypeSet *source, Type type) = 0;
+
+    /*
+     * For constraints attached to an object property's type set, mark the
+     * property as having its configuration changed.
+     */
+    virtual void newPropertyState(JSContext *cx, TypeSet *source) {}
+
+    /*
+     * For constraints attached to the JSID_EMPTY type set on an object,
+     * indicate a change in one of the object's dynamic property flags or other
+     * state.
+     */
+    virtual void newObjectState(JSContext *cx, TypeObject *object) {}
+
+    /*
+     * If the data this constraint refers to is still live, copy it into the
+     * zone's new allocator. Type constraints only hold weak references.
+     */
+    virtual bool sweep(TypeZone &zone, TypeConstraint **res) = 0;
+};
+
+/* Flags and other state stored in TypeSet::flags */
+enum MOZ_ENUM_TYPE(uint32_t) {
+    TYPE_FLAG_UNDEFINED =  0x1,
+    TYPE_FLAG_NULL      =  0x2,
+    TYPE_FLAG_BOOLEAN   =  0x4,
+    TYPE_FLAG_INT32     =  0x8,
+    TYPE_FLAG_DOUBLE    = 0x10,
+    TYPE_FLAG_STRING    = 0x20,
+    TYPE_FLAG_LAZYARGS  = 0x40,
+    TYPE_FLAG_ANYOBJECT = 0x80,
+
+    /* Mask containing all primitives */
+    TYPE_FLAG_PRIMITIVE = TYPE_FLAG_UNDEFINED | TYPE_FLAG_NULL | TYPE_FLAG_BOOLEAN |
+                          TYPE_FLAG_INT32 | TYPE_FLAG_DOUBLE | TYPE_FLAG_STRING,
+
+    /* Mask/shift for the number of objects in objectSet */
+    TYPE_FLAG_OBJECT_COUNT_MASK   = 0x1f00,
+    TYPE_FLAG_OBJECT_COUNT_SHIFT  = 8,
+    TYPE_FLAG_OBJECT_COUNT_LIMIT  =
+        TYPE_FLAG_OBJECT_COUNT_MASK >> TYPE_FLAG_OBJECT_COUNT_SHIFT,
+
+    /* Whether the contents of this type set are totally unknown. */
+    TYPE_FLAG_UNKNOWN             = 0x00002000,
+
+    /* Mask of normal type flags on a type set. */
+    TYPE_FLAG_BASE_MASK           = 0x000020ff,
+
+    /* Additional flags for HeapTypeSet sets. */
+
+    /*
+     * Whether the property has ever been deleted or reconfigured to behave
+     * differently from a plain data property, other than making the property
+     * non-writable.
+     */
+    TYPE_FLAG_NON_DATA_PROPERTY = 0x00004000,
+
+    /* Whether the property has ever been made non-writable. */
+    TYPE_FLAG_NON_WRITABLE_PROPERTY = 0x00008000,
+
+    /*
+     * Whether the property is definitely in a particular slot on all objects
+     * from which it has not been deleted or reconfigured. For singletons
+     * this may be a fixed or dynamic slot, and for other objects this will be
+     * a fixed slot.
+     *
+     * If the property is definite, mask and shift storing the slot + 1.
+     * Otherwise these bits are clear.
+     */
+    TYPE_FLAG_DEFINITE_MASK       = 0xffff0000,
+    TYPE_FLAG_DEFINITE_SHIFT      = 16
+};
+typedef uint32_t TypeFlags;
+
+/* Flags and other state stored in TypeObject::flags */
+enum MOZ_ENUM_TYPE(uint32_t) {
+    /* Whether this type object is associated with some allocation site. */
+    OBJECT_FLAG_FROM_ALLOCATION_SITE  = 0x1,
+
+    /* If set, addendum information should not be installed on this object. */
+    OBJECT_FLAG_ADDENDUM_CLEARED      = 0x2,
+
+    /*
+     * If set, the object's prototype might be in the nursery and can't be
+     * used during Ion compilation (which may be occurring off thread).
+     */
+    OBJECT_FLAG_NURSERY_PROTO         = 0x4,
+
+    /*
+     * Whether we have ensured all type sets in the compartment contain
+     * ANYOBJECT instead of this object.
+     */
+    OBJECT_FLAG_SETS_MARKED_UNKNOWN   = 0x8,
+
+    /* Mask/shift for the number of properties in propertySet */
+    OBJECT_FLAG_PROPERTY_COUNT_MASK   = 0xfff0,
+    OBJECT_FLAG_PROPERTY_COUNT_SHIFT  = 4,
+    OBJECT_FLAG_PROPERTY_COUNT_LIMIT  =
+        OBJECT_FLAG_PROPERTY_COUNT_MASK >> OBJECT_FLAG_PROPERTY_COUNT_SHIFT,
+
+    /* Whether any objects this represents may have sparse indexes. */
+    OBJECT_FLAG_SPARSE_INDEXES        = 0x00010000,
+
+    /* Whether any objects this represents may not have packed dense elements. */
+    OBJECT_FLAG_NON_PACKED            = 0x00020000,
+
+    /*
+     * Whether any objects this represents may be arrays whose length does not
+     * fit in an int32.
+     */
+    OBJECT_FLAG_LENGTH_OVERFLOW       = 0x00040000,
+
+    /* Whether any objects have been iterated over. */
+    OBJECT_FLAG_ITERATED              = 0x00080000,
+
+    /* For a global object, whether flags were set on the RegExpStatics. */
+    OBJECT_FLAG_REGEXP_FLAGS_SET      = 0x00100000,
+
+    /*
+     * For the function on a run-once script, whether the function has actually
+     * run multiple times.
+     */
+    OBJECT_FLAG_RUNONCE_INVALIDATED   = 0x00200000,
+
+    /*
+     * Whether objects with this type should be allocated directly in the
+     * tenured heap.
+     */
+    OBJECT_FLAG_PRE_TENURE            = 0x00400000,
+
+    /*
+     * Whether all properties of this object are considered unknown.
+     * If set, all other flags in DYNAMIC_MASK will also be set.
+     */
+    OBJECT_FLAG_UNKNOWN_PROPERTIES    = 0x00800000,
+
+    /* Flags which indicate dynamic properties of represented objects. */
+    OBJECT_FLAG_DYNAMIC_MASK          = 0x00ff0000,
+
+    /* Mask for objects created with unknown properties. */
+    OBJECT_FLAG_UNKNOWN_MASK =
+        OBJECT_FLAG_DYNAMIC_MASK
+      | OBJECT_FLAG_SETS_MARKED_UNKNOWN
+};
+typedef uint32_t TypeObjectFlags;
+
+class StackTypeSet;
+class HeapTypeSet;
+class TemporaryTypeSet;
+
+/*
+ * Information about the set of types associated with an lvalue. There are
+ * three kinds of type sets:
+ *
+ * - StackTypeSet are associated with TypeScripts, for arguments and values
+ *   observed at property reads. These are implicitly frozen on compilation
+ *   and do not have constraints attached to them.
+ *
+ * - HeapTypeSet are associated with the properties of TypeObjects. These
+ *   may have constraints added to them to trigger invalidation of compiled
+ *   code.
+ *
+ * - TemporaryTypeSet are created during compilation and do not outlive
+ *   that compilation.
+ */
+class TypeSet
+{
+  protected:
+    /* Flags for this type set. */
+    TypeFlags flags;
+
+    /* Possible objects this type set can represent. */
+    TypeObjectKey **objectSet;
+
+  public:
+
+    TypeSet()
+      : flags(0), objectSet(nullptr)
+    {}
+
+    void print();
+
+    /* Whether this set contains a specific type. */
+    inline bool hasType(Type type) const;
+
+    TypeFlags baseFlags() const { return flags & TYPE_FLAG_BASE_MASK; }
+    bool unknown() const { return !!(flags & TYPE_FLAG_UNKNOWN); }
+    bool unknownObject() const { return !!(flags & (TYPE_FLAG_UNKNOWN | TYPE_FLAG_ANYOBJECT)); }
+    bool empty() const { return !baseFlags() && !baseObjectCount(); }
+
+    bool hasAnyFlag(TypeFlags flags) const {
+        JS_ASSERT((flags & TYPE_FLAG_BASE_MASK) == flags);
+        return !!(baseFlags() & flags);
+    }
+
+    bool nonDataProperty() const {
+        return flags & TYPE_FLAG_NON_DATA_PROPERTY;
+    }
+    bool nonWritableProperty() const {
+        return flags & TYPE_FLAG_NON_WRITABLE_PROPERTY;
+    }
+    bool definiteProperty() const { return flags & TYPE_FLAG_DEFINITE_MASK; }
+    unsigned definiteSlot() const {
+        JS_ASSERT(definiteProperty());
+        return (flags >> TYPE_FLAG_DEFINITE_SHIFT) - 1;
+    }
+
+    /* Join two type sets into a new set. The result should not be modified further. */
+    static TemporaryTypeSet *unionSets(TypeSet *a, TypeSet *b, LifoAlloc *alloc);
+
+    /* Add a type to this set using the specified allocator. */
+    void addType(Type type, LifoAlloc *alloc);
+
+    /* Get a list of all types in this set. */
+    typedef Vector<Type, 1, SystemAllocPolicy> TypeList;
+    bool enumerateTypes(TypeList *list);
+
+    /*
+     * Iterate through the objects in this set. getObjectCount overapproximates
+     * in the hash case (see SET_ARRAY_SIZE in jsinferinlines.h), and getObject
+     * may return nullptr.
+     */
+    inline unsigned getObjectCount() const;
+    inline TypeObjectKey *getObject(unsigned i) const;
+    inline JSObject *getSingleObject(unsigned i) const;
+    inline TypeObject *getTypeObject(unsigned i) const;
+
+    /* The Class of an object in this set. */
+    inline const Class *getObjectClass(unsigned i) const;
+
+    bool canSetDefinite(unsigned slot) {
+        // Note: the cast is required to work around an MSVC issue.
+        return (slot + 1) <= (unsigned(TYPE_FLAG_DEFINITE_MASK) >> TYPE_FLAG_DEFINITE_SHIFT);
+    }
+    void setDefinite(unsigned slot) {
+        JS_ASSERT(canSetDefinite(slot));
+        flags |= ((slot + 1) << TYPE_FLAG_DEFINITE_SHIFT);
+        JS_ASSERT(definiteSlot() == slot);
+    }
+
+    /* Whether any values in this set might have the specified type. */
+    bool mightBeMIRType(jit::MIRType type);
+
+    /*
+     * Get whether this type set is known to be a subset of other.
+     * This variant doesn't freeze constraints. That variant is called knownSubset
+     */
+    bool isSubset(TypeSet *other);
+
+    /* Forward all types in this set to the specified constraint. */
+    bool addTypesToConstraint(JSContext *cx, TypeConstraint *constraint);
+
+    // Clone a type set into an arbitrary allocator.
+    TemporaryTypeSet *clone(LifoAlloc *alloc) const;
+    bool clone(LifoAlloc *alloc, TemporaryTypeSet *result) const;
+
+    // Create a new TemporaryTypeSet where undefined and/or null has been filtered out.
+    TemporaryTypeSet *filter(LifoAlloc *alloc, bool filterUndefined, bool filterNull) const;
+
+  protected:
+    uint32_t baseObjectCount() const {
+        return (flags & TYPE_FLAG_OBJECT_COUNT_MASK) >> TYPE_FLAG_OBJECT_COUNT_SHIFT;
+    }
+    inline void setBaseObjectCount(uint32_t count);
+
+    void clearObjects();
+};
+
+/* Superclass common to stack and heap type sets. */
+class ConstraintTypeSet : public TypeSet
+{
+  public:
+    /* Chain of constraints which propagate changes out from this type set. */
+    TypeConstraint *constraintList;
+
+    ConstraintTypeSet() : constraintList(nullptr) {}
+
+    /*
+     * Add a type to this set, calling any constraint handlers if this is a new
+     * possible type.
+     */
+    void addType(ExclusiveContext *cx, Type type);
+
+    /* Add a new constraint to this set. */
+    bool addConstraint(JSContext *cx, TypeConstraint *constraint, bool callExisting = true);
+
+    inline void sweep(JS::Zone *zone, bool *oom);
+};
+
+class StackTypeSet : public ConstraintTypeSet
+{
+  public:
+};
+
+class HeapTypeSet : public ConstraintTypeSet
+{
+    inline void newPropertyState(ExclusiveContext *cx);
+
+  public:
+    /* Mark this type set as representing a non-data property. */
+    inline void setNonDataProperty(ExclusiveContext *cx);
+    inline void setNonDataPropertyIgnoringConstraints(); // Variant for use during GC.
+
+    /* Mark this type set as representing a non-writable property. */
+    inline void setNonWritableProperty(ExclusiveContext *cx);
+};
+
+class CompilerConstraintList;
+
+CompilerConstraintList *
+NewCompilerConstraintList(jit::TempAllocator &alloc);
+
+class TemporaryTypeSet : public TypeSet
+{
+  public:
+    TemporaryTypeSet() {}
+    TemporaryTypeSet(Type type);
+
+    TemporaryTypeSet(uint32_t flags, TypeObjectKey **objectSet) {
+        this->flags = flags;
+        this->objectSet = objectSet;
+    }
+
+    /*
+     * Constraints for JIT compilation.
+     *
+     * Methods for JIT compilation. These must be used when a script is
+     * currently being compiled (see AutoEnterCompilation) and will add
+     * constraints ensuring that if the return value change in the future due
+     * to new type information, the script's jitcode will be discarded.
+     */
+
+    /* Get any type tag which all values in this set must have. */
+    jit::MIRType getKnownMIRType();
+
+    bool isMagicArguments() { return getKnownMIRType() == jit::MIRType_MagicOptimizedArguments; }
+
+    /* Whether this value may be an object. */
+    bool maybeObject() { return unknownObject() || baseObjectCount() > 0; }
+
+    /*
+     * Whether this typeset represents a potentially sentineled object value:
+     * the value may be an object or null or undefined.
+     * Returns false if the value cannot ever be an object.
+     */
+    bool objectOrSentinel() {
+        TypeFlags flags = TYPE_FLAG_UNDEFINED | TYPE_FLAG_NULL | TYPE_FLAG_ANYOBJECT;
+        if (baseFlags() & (~flags & TYPE_FLAG_BASE_MASK))
+            return false;
+
+        return hasAnyFlag(TYPE_FLAG_ANYOBJECT) || baseObjectCount() > 0;
+    }
+
+    /* Whether the type set contains objects with any of a set of flags. */
+    bool hasObjectFlags(CompilerConstraintList *constraints, TypeObjectFlags flags);
+
+    /* Get the class shared by all objects in this set, or nullptr. */
+    const Class *getKnownClass();
+
+    /* Result returned from forAllClasses */
+    enum ForAllResult {
+        EMPTY=1,                // Set empty
+        ALL_TRUE,               // Set not empty and predicate returned true for all classes
+        ALL_FALSE,              // Set not empty and predicate returned false for all classes
+        MIXED,                  // Set not empty and predicate returned false for some classes
+                                // and true for others, or set contains an unknown or non-object
+                                // type
+    };
+
+    /* Apply func to the members of the set and return an appropriate result.
+     * The iteration may end early if the result becomes known early.
+     */
+    ForAllResult forAllClasses(bool (*func)(const Class *clasp));
+
+    /* Get the prototype shared by all objects in this set, or nullptr. */
+    JSObject *getCommonPrototype();
+
+    /* Get the typed array type of all objects in this set, or TypedArrayObject::TYPE_MAX. */
+    int getTypedArrayType();
+
+    /* Whether all objects have JSCLASS_IS_DOMJSCLASS set. */
+    bool isDOMClass();
+
+    /* Whether clasp->isCallable() is true for one or more objects in this set. */
+    bool maybeCallable();
+
+    /* Whether clasp->emulatesUndefined() is true for one or more objects in this set. */
+    bool maybeEmulatesUndefined();
+
+    /* Get the single value which can appear in this type set, otherwise nullptr. */
+    JSObject *getSingleton();
+
+    /* Whether any objects in the type set needs a barrier on id. */
+    bool propertyNeedsBarrier(CompilerConstraintList *constraints, jsid id);
+
+    /*
+     * Whether this set contains all types in other, except (possibly) the
+     * specified type.
+     */
+    bool filtersType(const TemporaryTypeSet *other, Type type) const;
+
+    enum DoubleConversion {
+        /* All types in the set should use eager double conversion. */
+        AlwaysConvertToDoubles,
+
+        /* Some types in the set should use eager double conversion. */
+        MaybeConvertToDoubles,
+
+        /* No types should use eager double conversion. */
+        DontConvertToDoubles,
+
+        /* Some types should use eager double conversion, others cannot. */
+        AmbiguousDoubleConversion
+    };
+
+    /*
+     * Whether known double optimizations are possible for element accesses on
+     * objects in this type set.
+     */
+    DoubleConversion convertDoubleElements(CompilerConstraintList *constraints);
+};
+
+bool
+AddClearDefiniteGetterSetterForPrototypeChain(JSContext *cx, TypeObject *type, HandleId id);
+
+bool
+AddClearDefiniteFunctionUsesInScript(JSContext *cx, TypeObject *type,
+                                     JSScript *script, JSScript *calleeScript);
+
+/* Is this a reasonable PC to be doing inlining on? */
+inline bool isInlinableCall(jsbytecode *pc);
+
+/* Type information about a property. */
+struct Property
+{
+    /* Identifier for this property, JSID_VOID for the aggregate integer index property. */
+    HeapId id;
+
+    /* Possible types for this property, including types inherited from prototypes. */
+    HeapTypeSet types;
+
+    Property(jsid id)
+      : id(id)
+    {}
+
+    Property(const Property &o)
+      : id(o.id.get()), types(o.types)
+    {}
+
+    static uint32_t keyBits(jsid id) { return uint32_t(JSID_BITS(id)); }
+    static jsid getKey(Property *p) { return p->id; }
+};
+
+struct TypeNewScript;
+struct TypeTypedObject;
+
+struct TypeObjectAddendum
+{
+    enum Kind {
+        NewScript,
+        TypedObject
+    };
+
+    TypeObjectAddendum(Kind kind);
+
+    const Kind kind;
+
+    bool isNewScript() {
+        return kind == NewScript;
+    }
+
+    TypeNewScript *asNewScript() {
+        JS_ASSERT(isNewScript());
+        return (TypeNewScript*) this;
+    }
+
+    bool isTypedObject() {
+        return kind == TypedObject;
+    }
+
+    TypeTypedObject *asTypedObject() {
+        JS_ASSERT(isTypedObject());
+        return (TypeTypedObject*) this;
+    }
+
+    static inline void writeBarrierPre(TypeObjectAddendum *type);
+
+    static void writeBarrierPost(TypeObjectAddendum *newScript, void *addr) {}
+};
+
+/*
+ * Information attached to a TypeObject if it is always constructed using 'new'
+ * on a particular script. This is used to manage state related to the definite
+ * properties on the type object: these definite properties depend on type
+ * information which could change as the script executes (e.g. a scripted
+ * setter is added to a prototype object), and we need to ensure both that the
+ * appropriate type constraints are in place when necessary, and that we can
+ * remove the definite property information and repair the JS stack if the
+ * constraints are violated.
+ */
+struct TypeNewScript : public TypeObjectAddendum
+{
+    TypeNewScript();
+
+    HeapPtrFunction fun;
+
+    /*
+     * Template object to use for newly constructed objects. Reflects all
+     * definite properties the object will have and the allocation kind to use
+     * for the object. The allocation kind --- and template object itself ---
+     * is subject to change if objects allocated with this type are given
+     * dynamic slots later on due to new properties being added after the
+     * constructor function finishes.
+     */
+    HeapPtrObject templateObject;
+
+    /*
+     * Order in which properties become initialized. We need this in case a
+     * scripted setter is added to one of the object's prototypes while it is
+     * in the middle of being initialized, so we can walk the stack and fixup
+     * any objects which look for in-progress objects which were prematurely
+     * set with their final shape. Property assignments in inner frames are
+     * preceded by a series of SETPROP_FRAME entries specifying the stack down
+     * to the frame containing the write.
+     */
+    struct Initializer {
+        enum Kind {
+            SETPROP,
+            SETPROP_FRAME,
+            DONE
+        } kind;
+        uint32_t offset;
+        Initializer(Kind kind, uint32_t offset)
+          : kind(kind), offset(offset)
+        {}
+    };
+    Initializer *initializerList;
+
+    static inline void writeBarrierPre(TypeNewScript *newScript);
+};
+
+struct TypeTypedObject : public TypeObjectAddendum
+{
+  private:
+    HeapPtrObject descr_;
+
+  public:
+    TypeTypedObject(Handle<TypeDescr*> descr);
+
+    HeapPtrObject &descrHeapPtr() {
+        return descr_;
+    }
+
+    TypeDescr &descr();
+};
+
+/*
+ * Lazy type objects overview.
+ *
+ * Type objects which represent at most one JS object are constructed lazily.
+ * These include types for native functions, standard classes, scripted
+ * functions defined at the top level of global/eval scripts, and in some
+ * other cases. Typical web workloads often create many windows (and many
+ * copies of standard natives) and many scripts, with comparatively few
+ * non-singleton types.
+ *
+ * We can recover the type information for the object from examining it,
+ * so don't normally track the possible types of its properties as it is
+ * updated. Property type sets for the object are only constructed when an
+ * analyzed script attaches constraints to it: the script is querying that
+ * property off the object or another which delegates to it, and the analysis
+ * information is sensitive to changes in the property's type. Future changes
+ * to the property (whether those uncovered by analysis or those occurring
+ * in the VM) will treat these properties like those of any other type object.
+ */
+
+/* Type information about an object accessed by a script. */
+struct TypeObject : gc::BarrieredCell<TypeObject>
+{
+  private:
+    /* Class shared by object using this type. */
+    const Class *clasp_;
+
+    /* Prototype shared by objects using this type. */
+    HeapPtrObject proto_;
+
+    /*
+     * Whether there is a singleton JS object with this type. That JS object
+     * must appear in type sets instead of this; we include the back reference
+     * here to allow reverting the JS object to a lazy type.
+     */
+    HeapPtrObject singleton_;
+
+  public:
+
+    const Class *clasp() const {
+        return clasp_;
+    }
+
+    void setClasp(const Class *clasp) {
+        JS_ASSERT(singleton());
+        clasp_ = clasp;
+    }
+
+    TaggedProto proto() const {
+        return TaggedProto(proto_);
+    }
+
+    JSObject *singleton() const {
+        return singleton_;
+    }
+
+    // For use during marking, don't call otherwise.
+    HeapPtrObject &protoRaw() { return proto_; }
+    HeapPtrObject &singletonRaw() { return singleton_; }
+
+    void setProto(JSContext *cx, TaggedProto proto);
+    void setProtoUnchecked(TaggedProto proto) {
+        proto_ = proto.raw();
+    }
+
+    void initSingleton(JSObject *singleton) {
+        singleton_ = singleton;
+    }
+
+    /*
+     * Value held by singleton if this is a standin type for a singleton JS
+     * object whose type has not been constructed yet.
+     */
+    static const size_t LAZY_SINGLETON = 1;
+    bool lazy() const { return singleton() == (JSObject *) LAZY_SINGLETON; }
+
+  private:
+    /* Flags for this object. */
+    TypeObjectFlags flags_;
+
+    /*
+     * This field allows various special classes of objects to attach
+     * additional information to a type object:
+     *
+     * - `TypeNewScript`: If addendum is a `TypeNewScript`, it
+     *   indicates that objects of this type have always been
+     *   constructed using 'new' on the specified script, which adds
+     *   some number of properties to the object in a definite order
+     *   before the object escapes.
+     */
+    HeapPtr<TypeObjectAddendum> addendum;
+  public:
+
+    TypeObjectFlags flags() const {
+        return flags_;
+    }
+
+    void addFlags(TypeObjectFlags flags) {
+        flags_ |= flags;
+    }
+
+    void clearFlags(TypeObjectFlags flags) {
+        flags_ &= ~flags;
+    }
+
+    bool hasNewScript() const {
+        return addendum && addendum->isNewScript();
+    }
+
+    TypeNewScript *newScript() {
+        return addendum->asNewScript();
+    }
+
+    bool hasTypedObject() {
+        return addendum && addendum->isTypedObject();
+    }
+
+    TypeTypedObject *typedObject() {
+        return addendum->asTypedObject();
+    }
+
+    void setAddendum(TypeObjectAddendum *addendum);
+
+    /*
+     * Tag the type object for a binary data type descriptor, instance,
+     * or handle with the type representation of the data it points at.
+     * If this type object is already tagged with a binary data addendum,
+     * this addendum must already be associated with the same TypeRepresentation,
+     * and the method has no effect.
+     */
+    bool addTypedObjectAddendum(JSContext *cx, Handle<TypeDescr*> descr);
+
+  private:
+    /*
+     * Properties of this object. This may contain JSID_VOID, representing the
+     * types of all integer indexes of the object, and/or JSID_EMPTY, holding
+     * constraints listening to changes to the object's state.
+     *
+     * The type sets in the properties of a type object describe the possible
+     * values that can be read out of that property in actual JS objects.
+     * Properties only account for native properties (those with a slot and no
+     * specialized getter hook) and the elements of dense arrays. For accesses
+     * on such properties, the correspondence is as follows:
+     *
+     * 1. If the type has unknownProperties(), the possible properties and
+     *    value types for associated JSObjects are unknown.
+     *
+     * 2. Otherwise, for any JSObject obj with TypeObject type, and any jsid id
+     *    which is a property in obj, before obj->getProperty(id) the property
+     *    in type for id must reflect the result of the getProperty.
+     *
+     *    There is an exception for properties of global JS objects which
+     *    are undefined at the point where the property was (lazily) generated.
+     *    In such cases the property type set will remain empty, and the
+     *    'undefined' type will only be added after a subsequent assignment or
+     *    deletion. After these properties have been assigned a defined value,
+     *    the only way they can become undefined again is after such an assign
+     *    or deletion.
+     *
+     *    There is another exception for array lengths, which are special cased
+     *    by the compiler and VM and are not reflected in property types.
+     *
+     * We establish these by using write barriers on calls to setProperty and
+     * defineProperty which are on native properties, and on any jitcode which
+     * might update the property with a new type.
+     */
+    Property **propertySet;
+  public:
+
+    /* If this is an interpreted function, the function object. */
+    HeapPtrFunction interpretedFunction;
+
+#if JS_BITS_PER_WORD == 32
+    uint32_t padding;
+#endif
+
+    inline TypeObject(const Class *clasp, TaggedProto proto, TypeObjectFlags initialFlags);
+
+    bool hasAnyFlags(TypeObjectFlags flags) {
+        JS_ASSERT((flags & OBJECT_FLAG_DYNAMIC_MASK) == flags);
+        return !!(this->flags() & flags);
+    }
+    bool hasAllFlags(TypeObjectFlags flags) {
+        JS_ASSERT((flags & OBJECT_FLAG_DYNAMIC_MASK) == flags);
+        return (this->flags() & flags) == flags;
+    }
+
+    bool unknownProperties() {
+        JS_ASSERT_IF(flags() & OBJECT_FLAG_UNKNOWN_PROPERTIES,
+                     hasAllFlags(OBJECT_FLAG_DYNAMIC_MASK));
+        return !!(flags() & OBJECT_FLAG_UNKNOWN_PROPERTIES);
+    }
+
+    bool shouldPreTenure() {
+        return hasAnyFlags(OBJECT_FLAG_PRE_TENURE) && !unknownProperties();
+    }
+
+    bool hasTenuredProto() const {
+        return !(flags() & OBJECT_FLAG_NURSERY_PROTO);
+    }
+
+    gc::InitialHeap initialHeap(CompilerConstraintList *constraints);
+
+    bool canPreTenure() {
+        // Only types associated with particular allocation sites or 'new'
+        // scripts can be marked as needing pretenuring. Other types can be
+        // used for different purposes across the compartment and can't use
+        // this bit reliably.
+        if (unknownProperties())
+            return false;
+        return (flags() & OBJECT_FLAG_FROM_ALLOCATION_SITE) || hasNewScript();
+    }
+
+    void setShouldPreTenure(ExclusiveContext *cx) {
+        JS_ASSERT(canPreTenure());
+        setFlags(cx, OBJECT_FLAG_PRE_TENURE);
+    }
+
+    /*
+     * Get or create a property of this object. Only call this for properties which
+     * a script accesses explicitly.
+     */
+    inline HeapTypeSet *getProperty(ExclusiveContext *cx, jsid id);
+
+    /* Get a property only if it already exists. */
+    inline HeapTypeSet *maybeGetProperty(jsid id);
+
+    inline unsigned getPropertyCount();
+    inline Property *getProperty(unsigned i);
+
+    /* Helpers */
+
+    void updateNewPropertyTypes(ExclusiveContext *cx, jsid id, HeapTypeSet *types);
+    bool addDefiniteProperties(ExclusiveContext *cx, JSObject *obj);
+    bool matchDefiniteProperties(HandleObject obj);
+    void addPrototype(JSContext *cx, TypeObject *proto);
+    void addPropertyType(ExclusiveContext *cx, jsid id, Type type);
+    void addPropertyType(ExclusiveContext *cx, jsid id, const Value &value);
+    void markPropertyNonData(ExclusiveContext *cx, jsid id);
+    void markPropertyNonWritable(ExclusiveContext *cx, jsid id);
+    void markStateChange(ExclusiveContext *cx);
+    void setFlags(ExclusiveContext *cx, TypeObjectFlags flags);
+    void markUnknown(ExclusiveContext *cx);
+    void clearAddendum(ExclusiveContext *cx);
+    void clearNewScriptAddendum(ExclusiveContext *cx);
+    void clearTypedObjectAddendum(ExclusiveContext *cx);
+    void maybeClearNewScriptAddendumOnOOM();
+    bool isPropertyNonData(jsid id);
+    bool isPropertyNonWritable(jsid id);
+
+    void print();
+
+    inline void clearProperties();
+    inline void sweep(FreeOp *fop, bool *oom);
+
+    size_t sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+
+    /*
+     * Type objects don't have explicit finalizers. Memory owned by a type
+     * object pending deletion is released when weak references are sweeped
+     * from all the compartment's type objects.
+     */
+    void finalize(FreeOp *fop) {}
+
+    static inline ThingRootKind rootKind() { return THING_ROOT_TYPE_OBJECT; }
+
+    static inline uint32_t offsetOfClasp() {
+        return offsetof(TypeObject, clasp_);
+    }
+
+    static inline uint32_t offsetOfProto() {
+        return offsetof(TypeObject, proto_);
+    }
+
+  private:
+    inline uint32_t basePropertyCount() const;
+    inline void setBasePropertyCount(uint32_t count);
+
+    static void staticAsserts() {
+        JS_STATIC_ASSERT(offsetof(TypeObject, proto_) == offsetof(js::shadow::TypeObject, proto));
+    }
+};
+
+/*
+ * Entries for the per-compartment set of type objects which are 'new' types to
+ * use for some prototype and constructed with an optional script. This also
+ * includes entries for the set of lazy type objects in the compartment, which
+ * use a null script (though there are only a few of these per compartment).
+ */
+struct TypeObjectWithNewScriptEntry
+{
+    ReadBarriered<TypeObject> object;
+
+    // Note: This pointer is only used for equality and does not need a read barrier.
+    JSFunction *newFunction;
+
+    TypeObjectWithNewScriptEntry(TypeObject *object, JSFunction *newFunction)
+      : object(object), newFunction(newFunction)
+    {}
+
+    struct Lookup {
+        const Class *clasp;
+        TaggedProto hashProto;
+        TaggedProto matchProto;
+        JSFunction *newFunction;
+
+        Lookup(const Class *clasp, TaggedProto proto, JSFunction *newFunction)
+          : clasp(clasp), hashProto(proto), matchProto(proto), newFunction(newFunction)
+        {}
+
+#ifdef JSGC_GENERATIONAL
+        /*
+         * For use by generational post barriers only.  Look up an entry whose
+         * proto has been moved, but was hashed with the original value.
+         */
+        Lookup(const Class *clasp, TaggedProto hashProto, TaggedProto matchProto, JSFunction *newFunction)
+            : clasp(clasp), hashProto(hashProto), matchProto(matchProto), newFunction(newFunction)
+        {}
+#endif
+
+    };
+
+    static inline HashNumber hash(const Lookup &lookup);
+    static inline bool match(const TypeObjectWithNewScriptEntry &key, const Lookup &lookup);
+    static void rekey(TypeObjectWithNewScriptEntry &k, const TypeObjectWithNewScriptEntry& newKey) { k = newKey; }
+};
+typedef HashSet<TypeObjectWithNewScriptEntry,
+                TypeObjectWithNewScriptEntry,
+                SystemAllocPolicy> TypeObjectWithNewScriptSet;
+
+/* Whether to use a new type object when calling 'new' at script/pc. */
+bool
+UseNewType(JSContext *cx, JSScript *script, jsbytecode *pc);
+
+bool
+UseNewTypeForClone(JSFunction *fun);
+
+/*
+ * Whether Array.prototype, or an object on its proto chain, has an
+ * indexed property.
+ */
+bool
+ArrayPrototypeHasIndexedProperty(CompilerConstraintList *constraints, JSScript *script);
+
+/* Whether obj or any of its prototypes have an indexed property. */
+bool
+TypeCanHaveExtraIndexedProperties(CompilerConstraintList *constraints, TemporaryTypeSet *types);
+
+/* Persistent type information for a script, retained across GCs. */
+class TypeScript
+{
+    friend class ::JSScript;
+
+    // Variable-size array
+    StackTypeSet typeArray_[1];
+
+  public:
+    /* Array of type type sets for variables and JOF_TYPESET ops. */
+    StackTypeSet *typeArray() const {
+        // Ensure typeArray_ is the last data member of TypeScript.
+        JS_STATIC_ASSERT(sizeof(TypeScript) ==
+            sizeof(typeArray_) + offsetof(TypeScript, typeArray_));
+        return const_cast<StackTypeSet *>(typeArray_);
+    }
+
+    static inline size_t SizeIncludingTypeArray(size_t arraySize) {
+        // Ensure typeArray_ is the last data member of TypeScript.
+        JS_STATIC_ASSERT(sizeof(TypeScript) ==
+            sizeof(StackTypeSet) + offsetof(TypeScript, typeArray_));
+        return offsetof(TypeScript, typeArray_) + arraySize * sizeof(StackTypeSet);
+    }
+
+    static inline unsigned NumTypeSets(JSScript *script);
+
+    static inline StackTypeSet *ThisTypes(JSScript *script);
+    static inline StackTypeSet *ArgTypes(JSScript *script, unsigned i);
+
+    /* Get the type set for values observed at an opcode. */
+    static inline StackTypeSet *BytecodeTypes(JSScript *script, jsbytecode *pc);
+
+    template <typename TYPESET>
+    static inline TYPESET *BytecodeTypes(JSScript *script, jsbytecode *pc, uint32_t *bytecodeMap,
+                                         uint32_t *hint, TYPESET *typeArray);
+
+    /* Get a type object for an allocation site in this script. */
+    static inline TypeObject *InitObject(JSContext *cx, JSScript *script, jsbytecode *pc,
+                                         JSProtoKey kind);
+
+    /*
+     * Monitor a bytecode pushing any value. This must be called for any opcode
+     * which is JOF_TYPESET, and where either the script has not been analyzed
+     * by type inference or where the pc has type barriers. For simplicity, we
+     * always monitor JOF_TYPESET opcodes in the interpreter and stub calls,
+     * and only look at barriers when generating JIT code for the script.
+     */
+    static inline void Monitor(JSContext *cx, JSScript *script, jsbytecode *pc,
+                               const js::Value &val);
+    static inline void Monitor(JSContext *cx, const js::Value &rval);
+
+    /* Monitor an assignment at a SETELEM on a non-integer identifier. */
+    static inline void MonitorAssign(JSContext *cx, HandleObject obj, jsid id);
+
+    /* Add a type for a variable in a script. */
+    static inline void SetThis(JSContext *cx, JSScript *script, Type type);
+    static inline void SetThis(JSContext *cx, JSScript *script, const js::Value &value);
+    static inline void SetArgument(JSContext *cx, JSScript *script, unsigned arg, Type type);
+    static inline void SetArgument(JSContext *cx, JSScript *script, unsigned arg,
+                                   const js::Value &value);
+
+    /*
+     * Freeze all the stack type sets in a script, for a compilation. Returns
+     * copies of the type sets which will be checked against the actual ones
+     * under FinishCompilation, to detect any type changes.
+     */
+    static bool FreezeTypeSets(CompilerConstraintList *constraints, JSScript *script,
+                               TemporaryTypeSet **pThisTypes,
+                               TemporaryTypeSet **pArgTypes,
+                               TemporaryTypeSet **pBytecodeTypes);
+
+    static void Purge(JSContext *cx, HandleScript script);
+
+    static void Sweep(FreeOp *fop, JSScript *script, bool *oom);
+    void destroy();
+
+    size_t sizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const {
+        return mallocSizeOf(this);
+    }
+
+#ifdef DEBUG
+    void printTypes(JSContext *cx, HandleScript script) const;
+#endif
+};
+
+void
+FillBytecodeTypeMap(JSScript *script, uint32_t *bytecodeMap);
+
+class RecompileInfo;
+
+// Allocate a CompilerOutput for a finished compilation and generate the type
+// constraints for the compilation. Returns whether the type constraints
+// still hold.
+bool
+FinishCompilation(JSContext *cx, HandleScript script, ExecutionMode executionMode,
+                  CompilerConstraintList *constraints, RecompileInfo *precompileInfo);
+
+// Update the actual types in any scripts queried by constraints with any
+// speculative types added during the definite properties analysis.
+void
+FinishDefinitePropertiesAnalysis(JSContext *cx, CompilerConstraintList *constraints);
+
+struct ArrayTableKey;
+typedef HashMap<ArrayTableKey,ReadBarriered<TypeObject>,ArrayTableKey,SystemAllocPolicy> ArrayTypeTable;
+
+struct ObjectTableKey;
+struct ObjectTableEntry;
+typedef HashMap<ObjectTableKey,ObjectTableEntry,ObjectTableKey,SystemAllocPolicy> ObjectTypeTable;
+
+struct AllocationSiteKey;
+typedef HashMap<AllocationSiteKey,ReadBarriered<TypeObject>,AllocationSiteKey,SystemAllocPolicy> AllocationSiteTable;
+
+class HeapTypeSetKey;
+
+// Type set entry for either a JSObject with singleton type or a non-singleton TypeObject.
+struct TypeObjectKey
+{
+    static intptr_t keyBits(TypeObjectKey *obj) { return (intptr_t) obj; }
+    static TypeObjectKey *getKey(TypeObjectKey *obj) { return obj; }
+
+    static TypeObjectKey *get(JSObject *obj) {
+        JS_ASSERT(obj);
+        return (TypeObjectKey *) (uintptr_t(obj) | 1);
+    }
+    static TypeObjectKey *get(TypeObject *obj) {
+        JS_ASSERT(obj);
+        return (TypeObjectKey *) obj;
+    }
+
+    bool isTypeObject() {
+        return (uintptr_t(this) & 1) == 0;
+    }
+    bool isSingleObject() {
+        return (uintptr_t(this) & 1) != 0;
+    }
+
+    TypeObject *asTypeObject() {
+        JS_ASSERT(isTypeObject());
+        return (TypeObject *) this;
+    }
+    JSObject *asSingleObject() {
+        JS_ASSERT(isSingleObject());
+        return (JSObject *) (uintptr_t(this) & ~1);
+    }
+
+    const Class *clasp();
+    TaggedProto proto();
+    bool hasTenuredProto();
+    JSObject *singleton();
+    TypeNewScript *newScript();
+
+    bool unknownProperties();
+    bool hasFlags(CompilerConstraintList *constraints, TypeObjectFlags flags);
+    void watchStateChangeForInlinedCall(CompilerConstraintList *constraints);
+    void watchStateChangeForNewScriptTemplate(CompilerConstraintList *constraints);
+    void watchStateChangeForTypedArrayData(CompilerConstraintList *constraints);
+    HeapTypeSetKey property(jsid id);
+    void ensureTrackedProperty(JSContext *cx, jsid id);
+
+    TypeObject *maybeType();
+};
+
+// Representation of a heap type property which may or may not be instantiated.
+// Heap properties for singleton types are instantiated lazily as they are used
+// by the compiler, but this is only done on the main thread. If we are
+// compiling off thread and use a property which has not yet been instantiated,
+// it will be treated as empty and non-configured and will be instantiated when
+// rejoining to the main thread. If it is in fact not empty, the compilation
+// will fail; to avoid this, we try to instantiate singleton property types
+// during generation of baseline caches.
+class HeapTypeSetKey
+{
+    friend class TypeObjectKey;
+
+    // Object and property being accessed.
+    TypeObjectKey *object_;
+    jsid id_;
+
+    // If instantiated, the underlying heap type set.
+    HeapTypeSet *maybeTypes_;
+
+  public:
+    HeapTypeSetKey()
+      : object_(nullptr), id_(JSID_EMPTY), maybeTypes_(nullptr)
+    {}
+
+    TypeObjectKey *object() const { return object_; }
+    jsid id() const { return id_; }
+    HeapTypeSet *maybeTypes() const { return maybeTypes_; }
+
+    bool instantiate(JSContext *cx);
+
+    void freeze(CompilerConstraintList *constraints);
+    jit::MIRType knownMIRType(CompilerConstraintList *constraints);
+    bool nonData(CompilerConstraintList *constraints);
+    bool nonWritable(CompilerConstraintList *constraints);
+    bool isOwnProperty(CompilerConstraintList *constraints);
+    bool knownSubset(CompilerConstraintList *constraints, const HeapTypeSetKey &other);
+    JSObject *singleton(CompilerConstraintList *constraints);
+    bool needsBarrier(CompilerConstraintList *constraints);
+};
+
+/*
+ * Information about the result of the compilation of a script.  This structure
+ * stored in the TypeCompartment is indexed by the RecompileInfo. This
+ * indirection enables the invalidation of all constraints related to the same
+ * compilation.
+ */
+class CompilerOutput
+{
+    // If this compilation has not been invalidated, the associated script and
+    // kind of compilation being performed.
+    JSScript *script_;
+    ExecutionMode mode_ : 2;
+
+    // Whether this compilation is about to be invalidated.
+    bool pendingInvalidation_ : 1;
+
+    // During sweeping, the list of compiler outputs is compacted and invalidated
+    // outputs are removed. This gives the new index for a valid compiler output.
+    uint32_t sweepIndex_ : 29;
+
+  public:
+    static const uint32_t INVALID_SWEEP_INDEX = (1 << 29) - 1;
+
+    CompilerOutput()
+      : script_(nullptr), mode_(SequentialExecution),
+        pendingInvalidation_(false), sweepIndex_(INVALID_SWEEP_INDEX)
+    {}
+
+    CompilerOutput(JSScript *script, ExecutionMode mode)
+      : script_(script), mode_(mode),
+        pendingInvalidation_(false), sweepIndex_(INVALID_SWEEP_INDEX)
+    {}
+
+    JSScript *script() const { return script_; }
+    inline ExecutionMode mode() const { return mode_; }
+
+    inline jit::IonScript *ion() const;
+
+    bool isValid() const {
+        return script_ != nullptr;
+    }
+    void invalidate() {
+        script_ = nullptr;
+    }
+
+    void setPendingInvalidation() {
+        pendingInvalidation_ = true;
+    }
+    bool pendingInvalidation() {
+        return pendingInvalidation_;
+    }
+
+    void setSweepIndex(uint32_t index) {
+        if (index >= INVALID_SWEEP_INDEX)
+            MOZ_CRASH();
+        sweepIndex_ = index;
+    }
+    void invalidateSweepIndex() {
+        sweepIndex_ = INVALID_SWEEP_INDEX;
+    }
+    uint32_t sweepIndex() {
+        JS_ASSERT(sweepIndex_ != INVALID_SWEEP_INDEX);
+        return sweepIndex_;
+    }
+};
+
+class RecompileInfo
+{
+    uint32_t outputIndex;
+
+  public:
+    RecompileInfo(uint32_t outputIndex = uint32_t(-1))
+      : outputIndex(outputIndex)
+    {}
+
+    bool operator == (const RecompileInfo &o) const {
+        return outputIndex == o.outputIndex;
+    }
+    CompilerOutput *compilerOutput(TypeZone &types) const;
+    CompilerOutput *compilerOutput(JSContext *cx) const;
+    bool shouldSweep(TypeZone &types);
+};
+
+/* Type information for a compartment. */
+struct TypeCompartment
+{
+    /* Constraint solving worklist structures. */
+
+    /* Number of scripts in this compartment. */
+    unsigned scriptCount;
+
+    /* Table for referencing types of objects keyed to an allocation site. */
+    AllocationSiteTable *allocationSiteTable;
+
+    /* Tables for determining types of singleton/JSON objects. */
+
+    ArrayTypeTable *arrayTypeTable;
+    ObjectTypeTable *objectTypeTable;
+
+  private:
+    void setTypeToHomogenousArray(ExclusiveContext *cx, JSObject *obj, Type type);
+
+  public:
+    void fixArrayType(ExclusiveContext *cx, JSObject *obj);
+    void fixObjectType(ExclusiveContext *cx, JSObject *obj);
+    void fixRestArgumentsType(ExclusiveContext *cx, JSObject *obj);
+
+    JSObject *newTypedObject(JSContext *cx, IdValuePair *properties, size_t nproperties);
+
+    TypeCompartment();
+    ~TypeCompartment();
+
+    inline JSCompartment *compartment();
+
+    /* Prints results of this compartment if spew is enabled or force is set. */
+    void print(JSContext *cx, bool force);
+
+    /*
+     * Make a function or non-function object associated with an optional
+     * script. The 'key' parameter here may be an array, typed array, function
+     * or JSProto_Object to indicate a type whose class is unknown (not just
+     * js_ObjectClass).
+     */
+    TypeObject *newTypeObject(ExclusiveContext *cx, const Class *clasp, Handle<TaggedProto> proto,
+                              TypeObjectFlags initialFlags = 0);
+
+    /* Get or make an object for an allocation site, and add to the allocation site table. */
+    TypeObject *addAllocationSiteTypeObject(JSContext *cx, AllocationSiteKey key);
+
+    /* Mark any type set containing obj as having a generic object type. */
+    void markSetsUnknown(JSContext *cx, TypeObject *obj);
+
+    void clearTables();
+    void sweep(FreeOp *fop);
+    void finalizeObjects();
+
+    void addSizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf,
+                                size_t *allocationSiteTables,
+                                size_t *arrayTypeTables,
+                                size_t *objectTypeTables);
+};
+
+void FixRestArgumentsType(ExclusiveContext *cxArg, JSObject *obj);
+
+struct TypeZone
+{
+    JS::Zone                     *zone_;
+
+    /* Pool for type information in this zone. */
+    static const size_t TYPE_LIFO_ALLOC_PRIMARY_CHUNK_SIZE = 8 * 1024;
+    js::LifoAlloc                typeLifoAlloc;
+
+    /*
+     * All Ion compilations that have occured in this zone, for indexing via
+     * RecompileInfo. This includes both valid and invalid compilations, though
+     * invalidated compilations are swept on GC.
+     */
+    Vector<CompilerOutput> *compilerOutputs;
+
+    /* Pending recompilations to perform before execution of JIT code can resume. */
+    Vector<RecompileInfo> *pendingRecompiles;
+
+    TypeZone(JS::Zone *zone);
+    ~TypeZone();
+
+    JS::Zone *zone() const { return zone_; }
+
+    void sweep(FreeOp *fop, bool releaseTypes, bool *oom);
+    void clearAllNewScriptAddendumsOnOOM();
+
+    /* Mark a script as needing recompilation once inference has finished. */
+    void addPendingRecompile(JSContext *cx, const RecompileInfo &info);
+    void addPendingRecompile(JSContext *cx, JSScript *script);
+
+    void processPendingRecompiles(FreeOp *fop);
+};
+
+enum SpewChannel {
+    ISpewOps,      /* ops: New constraints and types. */
+    ISpewResult,   /* result: Final type sets. */
+    SPEW_COUNT
+};
+
+#ifdef DEBUG
+
+const char * InferSpewColorReset();
+const char * InferSpewColor(TypeConstraint *constraint);
+const char * InferSpewColor(TypeSet *types);
+
+void InferSpew(SpewChannel which, const char *fmt, ...);
+const char * TypeString(Type type);
+const char * TypeObjectString(TypeObject *type);
+
+/* Check that the type property for id in obj contains value. */
+bool TypeHasProperty(JSContext *cx, TypeObject *obj, jsid id, const Value &value);
+
+#else
+
+inline const char * InferSpewColorReset() { return nullptr; }
+inline const char * InferSpewColor(TypeConstraint *constraint) { return nullptr; }
+inline const char * InferSpewColor(TypeSet *types) { return nullptr; }
+inline void InferSpew(SpewChannel which, const char *fmt, ...) {}
+inline const char * TypeString(Type type) { return nullptr; }
+inline const char * TypeObjectString(TypeObject *type) { return nullptr; }
+
+#endif
+
+/* Print a warning, dump state and abort the program. */
+MOZ_NORETURN void TypeFailure(JSContext *cx, const char *fmt, ...);
+
+} /* namespace types */
+} /* namespace js */
+
+#endif /* jsinfer_h */