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serenity/Userland/Libraries/LibJS/Runtime/ValueTraits.h
Timothy Flynn 115baa7e32 LibJS+Everywhere: Make PrimitiveString and Utf16String fallible
This makes construction of Utf16String fallible in OOM conditions. The
immediate impact is that PrimitiveString must then be fallible as well,
as it may either transcode UTF-8 to UTF-16, or create a UTF-16 string
from ropes.

There are a couple of places where it is very non-trivial to propagate
the error further. A FIXME has been added to those locations.
2023-01-08 12:13:15 +01:00

45 lines
1.6 KiB
C++

/*
* Copyright (c) 2020-2021, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2020-2021, Linus Groh <linusg@serenityos.org>
* Copyright (c) 2020-2022, Idan Horowitz <idan.horowitz@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <LibJS/Runtime/PrimitiveString.h>
#include <LibJS/Runtime/Value.h>
namespace JS {
struct ValueTraits : public Traits<Value> {
static unsigned hash(Value value)
{
VERIFY(!value.is_empty());
if (value.is_string()) {
// FIXME: Propagate this error.
return value.as_string().deprecated_string().release_value().hash();
}
if (value.is_bigint())
return value.as_bigint().big_integer().hash();
if (value.is_negative_zero())
value = Value(0);
// In the IEEE 754 standard a NaN value is encoded as any value from 0x7ff0000000000001 to 0x7fffffffffffffff,
// with the least significant bits (referred to as the 'payload') carrying some kind of diagnostic information
// indicating the source of the NaN. Since ECMA262 does not differentiate between different kinds of NaN values,
// Sets and Maps must not differentiate between them either.
// This is achieved by replacing any NaN value by a canonical qNaN.
else if (value.is_nan())
value = js_nan();
return u64_hash(value.encoded()); // FIXME: Is this the best way to hash pointers, doubles & ints?
}
static bool equals(const Value a, const Value b)
{
return same_value_zero(a, b);
}
};
}