mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2024-11-30 03:20:28 +00:00
2b69af2dfe
JS::Value stores 48 bit pointers to separately allocated objects in its payload. On x86-64, canonical addresses have their top 16 bits set to the same value as bit 47, effectively meaning that the value has to be sign-extended to get the pointer. AArch64, however, expects the topmost bits to be all zeros. This commit gates sign extension behind `#if ARCH(X86_64)`, and adds an `#error` for unsupported architectures, so that we do not forget to think about pointer handling when porting to a new architecture. Fixes #15290 Fixes SerenityOS/ladybird#56
115 lines
4.2 KiB
C++
115 lines
4.2 KiB
C++
/*
|
|
* Copyright (c) 2022, David Tuin <davidot@serenityos.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#include <LibJS/Runtime/Value.h>
|
|
#include <LibTest/TestCase.h>
|
|
|
|
using namespace JS;
|
|
|
|
template<typename Type>
|
|
static void test_nullptr_input()
|
|
{
|
|
Type* ptr = nullptr;
|
|
JS::Value val { ptr };
|
|
EXPECT(val.is_null());
|
|
EXPECT(!val.is_object());
|
|
EXPECT(!val.is_string());
|
|
EXPECT(!val.is_bigint());
|
|
EXPECT(!val.is_symbol());
|
|
EXPECT(!val.is_accessor());
|
|
EXPECT(!val.is_cell());
|
|
EXPECT(!val.is_number());
|
|
EXPECT(!val.is_undefined());
|
|
}
|
|
|
|
#define TEST_NULLPTR_INPUT(type) \
|
|
TEST_CASE(value_nullptr_input_##type) \
|
|
{ \
|
|
test_nullptr_input<type>(); \
|
|
}
|
|
|
|
TEST_NULLPTR_INPUT(Object);
|
|
TEST_NULLPTR_INPUT(PrimitiveString);
|
|
TEST_NULLPTR_INPUT(Symbol);
|
|
TEST_NULLPTR_INPUT(BigInt);
|
|
TEST_NULLPTR_INPUT(Accessor);
|
|
|
|
#undef TEST_NULLPTR_INPUT
|
|
|
|
TEST_CASE(valid_pointer_in_gives_same_pointer_out)
|
|
{
|
|
if (sizeof(void*) < sizeof(double))
|
|
return;
|
|
|
|
#define EXPECT_POINTER_TO_SURVIVE(input) \
|
|
{ \
|
|
JS::Value value(reinterpret_cast<Object*>(static_cast<u64>(input))); \
|
|
EXPECT(value.is_object()); \
|
|
EXPECT(!value.is_null()); \
|
|
auto extracted_pointer = JS::Value::extract_pointer_bits(value.encoded()); \
|
|
EXPECT_EQ(static_cast<u64>(input), extracted_pointer); \
|
|
}
|
|
|
|
EXPECT_POINTER_TO_SURVIVE(0x1);
|
|
EXPECT_POINTER_TO_SURVIVE(0x10);
|
|
EXPECT_POINTER_TO_SURVIVE(0x100);
|
|
EXPECT_POINTER_TO_SURVIVE(0x00007fffffffffff);
|
|
EXPECT_POINTER_TO_SURVIVE(0x0000700000000000);
|
|
EXPECT_POINTER_TO_SURVIVE(0x0000100000000000);
|
|
|
|
#if ARCH(X86_64)
|
|
// On x86-64, the top 16 bits of pointers are equal to bit 47.
|
|
EXPECT_POINTER_TO_SURVIVE(0xffff800000000000);
|
|
EXPECT_POINTER_TO_SURVIVE(0xffff800000000001);
|
|
EXPECT_POINTER_TO_SURVIVE(0xffff800000000010);
|
|
#elif ARCH(AARCH64)
|
|
// ... but they should contain zeroes on AArch64.
|
|
EXPECT_POINTER_TO_SURVIVE(0x0000800000000000);
|
|
EXPECT_POINTER_TO_SURVIVE(0x0000800000000001);
|
|
EXPECT_POINTER_TO_SURVIVE(0x0000800000000010);
|
|
#endif
|
|
|
|
#undef EXPECT_POINTER_TO_SURVIVE
|
|
}
|
|
|
|
TEST_CASE(non_canon_nans)
|
|
{
|
|
#define EXPECT_TO_BE_NAN(input) \
|
|
{ \
|
|
Value val { bit_cast<double>(input) }; \
|
|
EXPECT(val.is_nan()); \
|
|
EXPECT(val.is_number()); \
|
|
EXPECT(!val.is_integral_number()); \
|
|
EXPECT(!val.is_finite_number()); \
|
|
EXPECT(!val.is_infinity()); \
|
|
EXPECT(!val.is_empty()); \
|
|
EXPECT(!val.is_nullish()); \
|
|
}
|
|
|
|
EXPECT_TO_BE_NAN(CANON_NAN_BITS | 0x1);
|
|
EXPECT_TO_BE_NAN(CANON_NAN_BITS | 0x10);
|
|
EXPECT_TO_BE_NAN(CANON_NAN_BITS | (NULL_TAG << TAG_SHIFT));
|
|
EXPECT_TO_BE_NAN(CANON_NAN_BITS | (UNDEFINED_TAG << TAG_SHIFT));
|
|
EXPECT_TO_BE_NAN(CANON_NAN_BITS | (INT32_TAG << TAG_SHIFT) | 0x88);
|
|
EXPECT_TO_BE_NAN(CANON_NAN_BITS | (OBJECT_TAG << TAG_SHIFT));
|
|
EXPECT_TO_BE_NAN(CANON_NAN_BITS | (OBJECT_TAG << TAG_SHIFT) | 0x1230);
|
|
EXPECT_TO_BE_NAN(CANON_NAN_BITS | (STRING_TAG << TAG_SHIFT));
|
|
EXPECT_TO_BE_NAN(CANON_NAN_BITS | (STRING_TAG << TAG_SHIFT) | 0x1230);
|
|
|
|
u64 sign_bit = 1ULL << 63;
|
|
|
|
EXPECT_TO_BE_NAN(CANON_NAN_BITS | sign_bit | 0x1);
|
|
EXPECT_TO_BE_NAN(CANON_NAN_BITS | sign_bit | 0x10);
|
|
EXPECT_TO_BE_NAN(CANON_NAN_BITS | sign_bit | (NULL_TAG << TAG_SHIFT));
|
|
EXPECT_TO_BE_NAN(CANON_NAN_BITS | sign_bit | (UNDEFINED_TAG << TAG_SHIFT));
|
|
EXPECT_TO_BE_NAN(CANON_NAN_BITS | sign_bit | (INT32_TAG << TAG_SHIFT) | 0x88);
|
|
EXPECT_TO_BE_NAN(CANON_NAN_BITS | sign_bit | (OBJECT_TAG << TAG_SHIFT));
|
|
EXPECT_TO_BE_NAN(CANON_NAN_BITS | sign_bit | (OBJECT_TAG << TAG_SHIFT) | 0x1230);
|
|
EXPECT_TO_BE_NAN(CANON_NAN_BITS | sign_bit | (STRING_TAG << TAG_SHIFT));
|
|
EXPECT_TO_BE_NAN(CANON_NAN_BITS | sign_bit | (STRING_TAG << TAG_SHIFT) | 0x1230);
|
|
|
|
#undef EXPECT_TO_BE_NAN
|
|
}
|