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/*
* Copyright (c) 2021, Andrew Kaster <akaster@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/LEB128.h>
#include <AK/MemoryStream.h>
#include <AK/NumericLimits.h>
#include <LibTest/TestCase.h>
TEST_CASE(single_byte)
{
u32 output = {};
i32 output_signed = {};
u8 buf[] = { 0x00 };
InputMemoryStream stream({ buf, sizeof(buf) });
// less than/eq 0b0011_1111, signed == unsigned == raw byte
for (u8 i = 0u; i <= 0x3F; ++i) {
buf[0] = i;
stream.seek(0);
EXPECT(LEB128::read_unsigned(stream, output));
EXPECT_EQ(output, i);
EXPECT(!stream.handle_any_error());
stream.seek(0);
EXPECT(LEB128::read_signed(stream, output_signed));
EXPECT_EQ(output_signed, i);
EXPECT(!stream.handle_any_error());
}
// 0b0100_0000 to 0b0111_1111 unsigned == byte, signed = {{ 26'b(-1), 6'b(byte) }}
for (u8 i = 0x40u; i < 0x80; ++i) {
buf[0] = i;
stream.seek(0);
EXPECT(LEB128::read_unsigned(stream, output));
EXPECT_EQ(output, i);
EXPECT(!stream.handle_any_error());
stream.seek(0);
EXPECT(LEB128::read_signed(stream, output_signed));
EXPECT_EQ(output_signed, (i | (-1 & (~0x3F))));
EXPECT(!stream.handle_any_error());
}
// MSB set, but input too short
for (u16 i = 0x80; i <= 0xFF; ++i) {
buf[0] = static_cast<u8>(i);
stream.seek(0);
EXPECT(!LEB128::read_unsigned(stream, output));
EXPECT(stream.handle_any_error());
stream.seek(0);
EXPECT(!LEB128::read_signed(stream, output_signed));
EXPECT(stream.handle_any_error());
}
}
TEST_CASE(two_bytes)
{
u32 output = {};
i32 output_signed = {};
u8 buf[] = { 0x00, 0x1 };
InputMemoryStream stream({ buf, sizeof(buf) });
// Only test with first byte expecting more, otherwise equivalent to single byte case
for (u16 i = 0x80; i <= 0xFF; ++i) {
buf[0] = static_cast<u8>(i);
// less than/eq 0b0011_1111: signed == unsigned == (j << 7) + (7 MSB of i)
for (u8 j = 0u; j <= 0x3F; ++j) {
buf[1] = j;
stream.seek(0);
EXPECT(LEB128::read_unsigned(stream, output));
EXPECT_EQ(output, (static_cast<u32>(j) << 7) + (i & 0x7F));
EXPECT(!stream.handle_any_error());
stream.seek(0);
EXPECT(LEB128::read_signed(stream, output_signed));
EXPECT_EQ(output_signed, (static_cast<i32>(j) << 7) + (i & 0x7F));
EXPECT(!stream.handle_any_error());
}
// 0b0100_0000 to 0b0111_1111: unsigned == (j << 7) + (7 MSB of i), signed == {{ 19'b(-1), 6'b(j), 7'b(i) }}
for (u8 j = 0x40u; j < 0x80; ++j) {
buf[1] = j;
stream.seek(0);
EXPECT(LEB128::read_unsigned(stream, output));
EXPECT_EQ(output, (static_cast<u32>(j) << 7) + (i & 0x7F));
EXPECT(!stream.handle_any_error());
stream.seek(0);
EXPECT(LEB128::read_signed(stream, output_signed));
EXPECT_EQ(output_signed, ((static_cast<i32>(j) << 7) + (i & 0x7F)) | (-1 & (~0x3FFF)));
EXPECT(!stream.handle_any_error());
}
// MSB set on last byte, but input too short
for (u16 j = 0x80; j <= 0xFF; ++j) {
buf[1] = static_cast<u8>(j);
stream.seek(0);
EXPECT(!LEB128::read_unsigned(stream, output));
EXPECT(stream.handle_any_error());
stream.seek(0);
EXPECT(!LEB128::read_signed(stream, output_signed));
EXPECT(stream.handle_any_error());
}
}
}
TEST_CASE(overflow_sizeof_output_unsigned)
{
u8 u32_max_plus_one[] = { 0x80, 0x80, 0x80, 0x80, 0x10 };
{
u32 out = 0;
InputMemoryStream stream({ u32_max_plus_one, sizeof(u32_max_plus_one) });
EXPECT(!LEB128::read_unsigned(stream, out));
EXPECT_EQ(out, 0u);
EXPECT(!stream.handle_any_error());
u64 out64 = 0;
stream.seek(0);
EXPECT(LEB128::read_unsigned(stream, out64));
EXPECT_EQ(out64, static_cast<u64>(NumericLimits<u32>::max()) + 1);
EXPECT(!stream.handle_any_error());
}
u8 u32_max[] = { 0xFF, 0xFF, 0xFF, 0xFF, 0x0F };
{
u32 out = 0;
InputMemoryStream stream({ u32_max, sizeof(u32_max) });
EXPECT(LEB128::read_unsigned(stream, out));
EXPECT_EQ(out, NumericLimits<u32>::max());
EXPECT(!stream.handle_any_error());
u64 out64 = 0;
stream.seek(0);
EXPECT(LEB128::read_unsigned(stream, out64));
EXPECT_EQ(out64, NumericLimits<u32>::max());
EXPECT(!stream.handle_any_error());
}
}
TEST_CASE(overflow_sizeof_output_signed)
{
u8 i32_max_plus_one[] = { 0x80, 0x80, 0x80, 0x80, 0x08 };
{
i32 out = 0;
InputMemoryStream stream({ i32_max_plus_one, sizeof(i32_max_plus_one) });
EXPECT(!LEB128::read_signed(stream, out));
EXPECT_EQ(out, 0);
EXPECT(!stream.handle_any_error());
i64 out64 = 0;
stream.seek(0);
EXPECT(LEB128::read_signed(stream, out64));
EXPECT_EQ(out64, static_cast<i64>(NumericLimits<i32>::max()) + 1);
EXPECT(!stream.handle_any_error());
}
u8 i32_max[] = { 0xFF, 0xFF, 0xFF, 0xFF, 0x07 };
{
i32 out = 0;
InputMemoryStream stream({ i32_max, sizeof(i32_max) });
EXPECT(LEB128::read_signed(stream, out));
EXPECT_EQ(out, NumericLimits<i32>::max());
EXPECT(!stream.handle_any_error());
i64 out64 = 0;
stream.seek(0);
EXPECT(LEB128::read_signed(stream, out64));
EXPECT_EQ(out64, NumericLimits<i32>::max());
EXPECT(!stream.handle_any_error());
}
u8 i32_min_minus_one[] = { 0xFF, 0xFF, 0xFF, 0xFF, 0x77 };
{
i32 out = 0;
InputMemoryStream stream({ i32_min_minus_one, sizeof(i32_min_minus_one) });
EXPECT(!LEB128::read_signed(stream, out));
EXPECT_EQ(out, 0);
EXPECT(!stream.handle_any_error());
i64 out64 = 0;
stream.seek(0);
EXPECT(LEB128::read_signed(stream, out64));
EXPECT_EQ(out64, static_cast<i64>(NumericLimits<i32>::min()) - 1);
EXPECT(!stream.handle_any_error());
}
u8 i32_min[] = { 0x80, 0x80, 0x80, 0x80, 0x78 };
{
i32 out = 0;
InputMemoryStream stream({ i32_min, sizeof(i32_min) });
EXPECT(LEB128::read_signed(stream, out));
EXPECT_EQ(out, NumericLimits<i32>::min());
EXPECT(!stream.handle_any_error());
i64 out64 = 0;
stream.seek(0);
EXPECT(LEB128::read_signed(stream, out64));
EXPECT_EQ(out64, NumericLimits<i32>::min());
EXPECT(!stream.handle_any_error());
}
}
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