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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
#include "vm/EqualityOperations.h" // js::LooselyEqual, js::StrictlyEqual, js::SameValue
#include "mozilla/Assertions.h" // MOZ_ASSERT, MOZ_ASSERT_IF
#include "jsnum.h" // js::StringToNumber
#include "jstypes.h" // JS_PUBLIC_API
#include "js/Context.h" // js::AssertHeapIsIdle
#include "js/Equality.h" // JS::LooselyEqual, JS::StrictlyEqual, JS::SameValue
#include "js/Result.h" // JS_TRY_VAR_OR_RETURN_FALSE
#include "js/RootingAPI.h" // JS::Rooted
#include "js/Value.h" // JS::Int32Value, JS::SameType, JS::Value
#include "vm/BigIntType.h" // JS::BigInt
#include "vm/ConstantCompareOperand.h"
#include "vm/JSContext.h" // CHECK_THREAD
#include "vm/JSObject.h" // js::ToPrimitive
#include "vm/StringType.h" // js::EqualStrings
#include "builtin/Boolean-inl.h" // js::EmulatesUndefined
#include "vm/JSContext-inl.h" // JSContext::check
static bool EqualGivenSameType(JSContext* cx, const JS::Value& lval,
const JS::Value& rval, bool* equal) {
MOZ_ASSERT(JS::SameType(lval, rval));
if (lval.isString()) {
return js::EqualStrings(cx, lval.toString(), rval.toString(), equal);
}
if (lval.isDouble()) {
*equal = (lval.toDouble() == rval.toDouble());
return true;
}
if (lval.isBigInt()) {
*equal = JS::BigInt::equal(lval.toBigInt(), rval.toBigInt());
return true;
}
// Note: we can do a bitwise comparison even for Int32Value because both
// Values have the same type.
MOZ_ASSERT(js::CanUseBitwiseCompareForStrictlyEqual(lval) || lval.isInt32());
*equal = (lval.asRawBits() == rval.asRawBits());
MOZ_ASSERT_IF(lval.isUndefined() || lval.isNull(), *equal);
return true;
}
static bool LooselyEqualBooleanAndOther(JSContext* cx,
JS::Handle<JS::Value> lval,
JS::Handle<JS::Value> rval,
bool* result) {
MOZ_ASSERT(!rval.isBoolean());
JS::Rooted<JS::Value> 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);
}
// ES2026 Draft rev e936549f1c05ac1b206ad4c5817e77ee3ecbc787
//
// IsLooselyEqual ( x, y )
bool js::LooselyEqual(JSContext* cx, JS::Handle<JS::Value> lval,
JS::Handle<JS::Value> rval, bool* result) {
// Step 1. If SameType(x, y) is true, then
if (JS::SameType(lval, rval)) {
// Step 1.a. Return IsStrictlyEqual(x, y).
return EqualGivenSameType(cx, lval, rval, result);
}
// NOTE: JS::SameType distinguishes between Int32 vs Double,
// but the spec's SameType doesn't.
if (lval.isNumber() && rval.isNumber()) {
*result = (lval.toNumber() == rval.toNumber());
return true;
}
// Step 2. If x is null and y is undefined, return true.
// Step 3. If x is undefined and y is null, return true.
// Step 4. Normative Optional
// If the host is a web browser or otherwise supports The
// [[IsHTMLDDA]] Internal Slot, then
// Step 4.a. If x is an Object, x has an [[IsHTMLDDA]] internal slot, and y
// is either undefined or null, return true.
// Step 4.b. If x is either undefined or null, y is an Object, and y has an
// [[IsHTMLDDA]] internal slot, return true.
if (lval.isNullOrUndefined()) {
*result = rval.isNullOrUndefined() ||
(rval.isObject() && EmulatesUndefined(&rval.toObject()));
return true;
}
if (rval.isNullOrUndefined()) {
MOZ_ASSERT(!lval.isNullOrUndefined());
*result = lval.isObject() && EmulatesUndefined(&lval.toObject());
return true;
}
// Step 5. If x is a Number and y is a String, return ! IsLooselyEqual(x, !
// ToNumber(y)).
if (lval.isNumber() && rval.isString()) {
double num;
if (!StringToNumber(cx, rval.toString(), &num)) {
return false;
}
*result = (lval.toNumber() == num);
return true;
}
// Step 6. If x is a String and y is a Number, return ! IsLooselyEqual(!
// ToNumber(x), y).
if (lval.isString() && rval.isNumber()) {
double num;
if (!StringToNumber(cx, lval.toString(), &num)) {
return false;
}
*result = (num == rval.toNumber());
return true;
}
// Step 7. If x is a BigInt and y is a String, then
if (lval.isBigInt() && rval.isString()) {
// Step 7.a. Let n be StringToBigInt(y).
BigInt* n;
JS::Rooted<JSString*> str(cx, rval.toString());
JS_TRY_VAR_OR_RETURN_FALSE(cx, n, StringToBigInt(cx, str));
if (!n) {
// Step 7.b. If n is undefined, return false.
*result = false;
return true;
}
// Step 7.c. Return ! IsLooselyEqual(x, n).
*result = JS::BigInt::equal(lval.toBigInt(), n);
return true;
}
// Step 8. If x is a String and y is a BigInt, return ! IsLooselyEqual(y,
// x).
if (lval.isString() && rval.isBigInt()) {
BigInt* n;
JS::Rooted<JSString*> str(cx, lval.toString());
JS_TRY_VAR_OR_RETURN_FALSE(cx, n, StringToBigInt(cx, str));
if (!n) {
*result = false;
return true;
}
*result = JS::BigInt::equal(rval.toBigInt(), n);
return true;
}
// Step 9. If x is a Boolean, return ! IsLooselyEqual(! ToNumber(x), y).
if (lval.isBoolean()) {
return LooselyEqualBooleanAndOther(cx, lval, rval, result);
}
// Step 10. If y is a Boolean, return ! IsLooselyEqual(x, ! ToNumber(y)).
if (rval.isBoolean()) {
return LooselyEqualBooleanAndOther(cx, rval, lval, result);
}
// Step 11. If x is either a String, a Number, a BigInt, or a Symbol and y
// is an Object, return ! IsLooselyEqual(x, ? ToPrimitive(y)).
if ((lval.isString() || lval.isNumber() || lval.isBigInt() ||
lval.isSymbol()) &&
rval.isObject()) {
JS::Rooted<JS::Value> rvalue(cx, rval);
if (!ToPrimitive(cx, &rvalue)) {
return false;
}
return js::LooselyEqual(cx, lval, rvalue, result);
}
// Step 12. If x is an Object and y is either a String, a Number, a BigInt,
// or a Symbol, return ! IsLooselyEqual(? ToPrimitive(x), y).
if (lval.isObject() && (rval.isString() || rval.isNumber() ||
rval.isBigInt() || rval.isSymbol())) {
JS::Rooted<JS::Value> lvalue(cx, lval);
if (!ToPrimitive(cx, &lvalue)) {
return false;
}
return js::LooselyEqual(cx, lvalue, rval, result);
}
// Step 13. If x is a BigInt and y is a Number, or if x is a Number and y
// is a BigInt, then
if (lval.isBigInt() && rval.isNumber()) {
// Step 13.a. If x is not finite or y is not finite, return false.
// Step 13.b. If ℝ(x) = ℝ(y), return true; otherwise return false.
*result = BigInt::equal(lval.toBigInt(), rval.toNumber());
return true;
}
if (lval.isNumber() && rval.isBigInt()) {
*result = BigInt::equal(rval.toBigInt(), lval.toNumber());
return true;
}
// Step 14. Return false.
*result = false;
return true;
}
JS_PUBLIC_API bool JS::LooselyEqual(JSContext* cx, Handle<Value> value1,
Handle<Value> value2, bool* equal) {
js::AssertHeapIsIdle();
CHECK_THREAD(cx);
cx->check(value1, value2);
MOZ_ASSERT(equal);
return js::LooselyEqual(cx, value1, value2, equal);
}
bool js::ConstantStrictEqual(const JS::Value& val, uint16_t operand) {
ConstantCompareOperand constant =
ConstantCompareOperand::fromRawValue(operand);
switch (constant.type()) {
case ConstantCompareOperand::EncodedType::Int32:
return val.isNumber() && val.toNumber() == double(constant.toInt32());
case ConstantCompareOperand::EncodedType::Boolean:
return val == BooleanValue(constant.toBoolean());
case ConstantCompareOperand::EncodedType::Undefined:
return val.isUndefined();
case ConstantCompareOperand::EncodedType::Null:
return val.isNull();
}
MOZ_CRASH("Unknown constant compare operand type");
}
bool js::StrictlyEqual(JSContext* cx, const JS::Value& lval,
const JS::Value& 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();
CHECK_THREAD(cx);
cx->check(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() && std::isnan(v.toDouble());
}
bool js::SameValue(JSContext* cx, const JS::Value& v1, const JS::Value& v2,
bool* same) {
if (IsNegativeZero(v1)) {
*same = IsNegativeZero(v2);
return true;
}
if (IsNegativeZero(v2)) {
*same = false;
return true;
}
return js::SameValueZero(cx, v1, v2, same);
}
JS_PUBLIC_API bool JS::SameValue(JSContext* cx, Handle<Value> value1,
Handle<Value> value2, bool* same) {
js::AssertHeapIsIdle();
CHECK_THREAD(cx);
cx->check(value1, value2);
MOZ_ASSERT(same);
return js::SameValue(cx, value1, value2, same);
}
bool js::SameValueZero(JSContext* cx, const Value& v1, const Value& v2,
bool* same) {
if (IsNaN(v1) && IsNaN(v2)) {
*same = true;
return true;
}
return js::StrictlyEqual(cx, v1, v2, same);
}