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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* 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/EqualityOperations.h" // js::LooselyEqual, js::StrictlyEqual, js::SameValue
#include "mozilla/Assertions.h" // MOZ_ASSERT, MOZ_ASSERT_IF
#include "jsapi.h" // js::AssertHeapIsIdle, CHECK_REQUEST
#include "jsnum.h" // js::StringToNumber
#include "jsobj.h" // js::ToPrimitive
#include "jsstr.h" // js::EqualStrings
#include "jstypes.h" // JS_PUBLIC_API
#include "js/Equality.h" // JS::LooselyEqual, JS::StrictlyEqual, JS::SameValue
#include "js/RootingAPI.h" // JS::Rooted, JS::Handle
#include "js/Value.h" // JS::Int32Value, JS::SameType, JS::Value
#include "jsboolinlines.h" // js::EmulatesUndefined
#include "jscntxtinlines.h" // js::assertSameCompartment
static inline bool
EqualGivenSameType(JSContext* cx, JS::HandleValue lval, JS::HandleValue rval, bool* equal)
{
MOZ_ASSERT(SameType(lval, rval));
if (lval.isString())
return EqualStrings(cx, lval.toString(), rval.toString(), equal);
if (lval.isDouble()) {
*equal = (lval.toDouble() == rval.toDouble());
return true;
}
if (lval.isGCThing()) { // objects or symbols
*equal = (lval.toGCThing() == rval.toGCThing());
return true;
}
*equal = lval.get().payloadAsRawUint32() == rval.get().payloadAsRawUint32();
MOZ_ASSERT_IF(lval.isUndefined() || lval.isNull(), *equal);
return true;
}
static inline bool
LooselyEqualBooleanAndOther(JSContext* cx, JS::HandleValue lval, JS::HandleValue rval, bool* result)
{
MOZ_ASSERT(!rval.isBoolean());
JS::RootedValue lvalue(cx, JS::Int32Value(lval.toBoolean() ? 1 : 0));
// The tail-call would end up in Step 3.
if (rval.isNumber()) {
*result = (lvalue.toNumber() == rval.toNumber());
return true;
}
// The tail-call would end up in Step 6.
if (rval.isString()) {
double num;
if (!StringToNumber(cx, rval.toString(), &num))
return false;
*result = (lvalue.toNumber() == num);
return true;
}
return js::LooselyEqual(cx, lvalue, rval, result);
}
// ES6 draft rev32 7.2.12 Abstract Equality Comparison
bool
js::LooselyEqual(JSContext* cx, JS::HandleValue lval, JS::HandleValue rval, bool* result)
{
// Step 3.
if (SameType(lval, rval))
return EqualGivenSameType(cx, lval, rval, result);
// Handle int32 x double.
if (lval.isNumber() && rval.isNumber()) {
*result = (lval.toNumber() == rval.toNumber());
return true;
}
// Step 4. This a bit more complex, because of the undefined emulating object.
if (lval.isNullOrUndefined()) {
// We can return early here, because null | undefined is only equal to the same set.
*result = rval.isNullOrUndefined() ||
(rval.isObject() && EmulatesUndefined(&rval.toObject()));
return true;
}
// Step 5.
if (rval.isNullOrUndefined()) {
MOZ_ASSERT(!lval.isNullOrUndefined());
*result = lval.isObject() && EmulatesUndefined(&lval.toObject());
return true;
}
// Step 6.
if (lval.isNumber() && rval.isString()) {
double num;
if (!StringToNumber(cx, rval.toString(), &num))
return false;
*result = (lval.toNumber() == num);
return true;
}
// Step 7.
if (lval.isString() && rval.isNumber()) {
double num;
if (!StringToNumber(cx, lval.toString(), &num))
return false;
*result = (num == rval.toNumber());
return true;
}
// Step 8.
if (lval.isBoolean())
return LooselyEqualBooleanAndOther(cx, lval, rval, result);
// Step 9.
if (rval.isBoolean())
return LooselyEqualBooleanAndOther(cx, rval, lval, result);
// Step 10.
if ((lval.isString() || lval.isNumber() || lval.isSymbol()) && rval.isObject()) {
JS::RootedValue rvalue(cx, rval);
if (!ToPrimitive(cx, &rvalue))
return false;
return js::LooselyEqual(cx, lval, rvalue, result);
}
// Step 11.
if (lval.isObject() && (rval.isString() || rval.isNumber() || rval.isSymbol())) {
JS::RootedValue lvalue(cx, lval);
if (!ToPrimitive(cx, &lvalue))
return false;
return js::LooselyEqual(cx, lvalue, rval, result);
}
// Step 12.
*result = false;
return true;
}
JS_PUBLIC_API(bool)
JS::LooselyEqual(JSContext* cx, Handle<Value> value1, Handle<Value> value2, bool* equal)
{
js::AssertHeapIsIdle(cx);
CHECK_REQUEST(cx);
js::assertSameCompartment(cx, value1, value2);
MOZ_ASSERT(equal);
return js::LooselyEqual(cx, value1, value2, equal);
}
bool
js::StrictlyEqual(JSContext* cx, JS::HandleValue lval, JS::HandleValue rval, bool* equal)
{
if (SameType(lval, rval))
return EqualGivenSameType(cx, lval, rval, equal);
if (lval.isNumber() && rval.isNumber()) {
*equal = (lval.toNumber() == rval.toNumber());
return true;
}
*equal = false;
return true;
}
JS_PUBLIC_API(bool)
JS::StrictlyEqual(JSContext* cx, Handle<Value> value1, Handle<Value> value2, bool* equal)
{
js::AssertHeapIsIdle(cx);
CHECK_REQUEST(cx);
js::assertSameCompartment(cx, value1, value2);
MOZ_ASSERT(equal);
return js::StrictlyEqual(cx, value1, value2, equal);
}
static inline bool
IsNegativeZero(const JS::Value& v)
{
return v.isDouble() && mozilla::IsNegativeZero(v.toDouble());
}
static inline bool
IsNaN(const JS::Value& v)
{
return v.isDouble() && mozilla::IsNaN(v.toDouble());
}
bool
js::SameValue(JSContext* cx, JS::HandleValue v1, JS::HandleValue v2, bool* same)
{
if (IsNegativeZero(v1)) {
*same = IsNegativeZero(v2);
return true;
}
if (IsNegativeZero(v2)) {
*same = false;
return true;
}
if (IsNaN(v1) && IsNaN(v2)) {
*same = true;
return true;
}
return js::StrictlyEqual(cx, v1, v2, same);
}
JS_PUBLIC_API(bool)
JS::SameValue(JSContext* cx, Handle<Value> value1, Handle<Value> value2, bool* same)
{
js::AssertHeapIsIdle(cx);
CHECK_REQUEST(cx);
js::assertSameCompartment(cx, value1, value2);
MOZ_ASSERT(same);
return js::SameValue(cx, value1, value2, same);
}
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