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llvm-mirror/unittests/Support/LEB128Test.cpp
Pavel Labath ae3c34854e [llvm/Support] Don't crash on empty nullptr ranges when decoding LEBs
Summary:
If the decoding functions are called with both start and end pointers
being nullptr, the function will crash due to a nullptr dereference.
This happens because the function does not recognise nullptr as a valid
end pointer.

Obviously, nobody is going to pass null pointers here deliberately, but
it can happen indirectly (as it did for me), when calling these
functions on an ArrayRef, as a default-initialized empty ArrayRef will
have both begin() and end() pointers equal to nullptr.

The fix is to simply remove the nullptr check. Passing nullptr for "end"
with a valid "begin" pointer will still work, as one cannot reach
nullptr by incrementing a valid pointer without triggerring UB.

Reviewers: dblaikie

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77304
2020-04-06 14:14:11 +02:00

374 lines
13 KiB
C++

//===- llvm/unittest/Support/LEB128Test.cpp - LEB128 function tests -------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/LEB128.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/raw_ostream.h"
#include "gtest/gtest.h"
#include <string>
using namespace llvm;
namespace {
TEST(LEB128Test, EncodeSLEB128) {
#define EXPECT_SLEB128_EQ(EXPECTED, VALUE, PAD) \
do { \
std::string Expected(EXPECTED, sizeof(EXPECTED) - 1); \
\
/* encodeSLEB128(uint64_t, raw_ostream &, unsigned) */ \
std::string Actual1; \
raw_string_ostream Stream(Actual1); \
encodeSLEB128(VALUE, Stream, PAD); \
Stream.flush(); \
EXPECT_EQ(Expected, Actual1); \
\
/* encodeSLEB128(uint64_t, uint8_t *, unsigned) */ \
uint8_t Buffer[32]; \
unsigned Size = encodeSLEB128(VALUE, Buffer, PAD); \
std::string Actual2(reinterpret_cast<const char *>(Buffer), Size); \
EXPECT_EQ(Expected, Actual2); \
} while (0)
// Encode SLEB128
EXPECT_SLEB128_EQ("\x00", 0, 0);
EXPECT_SLEB128_EQ("\x01", 1, 0);
EXPECT_SLEB128_EQ("\x7f", -1, 0);
EXPECT_SLEB128_EQ("\x3f", 63, 0);
EXPECT_SLEB128_EQ("\x41", -63, 0);
EXPECT_SLEB128_EQ("\x40", -64, 0);
EXPECT_SLEB128_EQ("\xbf\x7f", -65, 0);
EXPECT_SLEB128_EQ("\xc0\x00", 64, 0);
// Encode SLEB128 with some extra padding bytes
EXPECT_SLEB128_EQ("\x80\x00", 0, 2);
EXPECT_SLEB128_EQ("\x80\x80\x00", 0, 3);
EXPECT_SLEB128_EQ("\xff\x80\x00", 0x7f, 3);
EXPECT_SLEB128_EQ("\xff\x80\x80\x00", 0x7f, 4);
EXPECT_SLEB128_EQ("\x80\x81\x00", 0x80, 3);
EXPECT_SLEB128_EQ("\x80\x81\x80\x00", 0x80, 4);
EXPECT_SLEB128_EQ("\xc0\x7f", -0x40, 2);
EXPECT_SLEB128_EQ("\xc0\xff\x7f", -0x40, 3);
EXPECT_SLEB128_EQ("\x80\xff\x7f", -0x80, 3);
EXPECT_SLEB128_EQ("\x80\xff\xff\x7f", -0x80, 4);
#undef EXPECT_SLEB128_EQ
}
TEST(LEB128Test, EncodeULEB128) {
#define EXPECT_ULEB128_EQ(EXPECTED, VALUE, PAD) \
do { \
std::string Expected(EXPECTED, sizeof(EXPECTED) - 1); \
\
/* encodeULEB128(uint64_t, raw_ostream &, unsigned) */ \
std::string Actual1; \
raw_string_ostream Stream(Actual1); \
encodeULEB128(VALUE, Stream, PAD); \
Stream.flush(); \
EXPECT_EQ(Expected, Actual1); \
\
/* encodeULEB128(uint64_t, uint8_t *, unsigned) */ \
uint8_t Buffer[32]; \
unsigned Size = encodeULEB128(VALUE, Buffer, PAD); \
std::string Actual2(reinterpret_cast<const char *>(Buffer), Size); \
EXPECT_EQ(Expected, Actual2); \
} while (0)
// Encode ULEB128
EXPECT_ULEB128_EQ("\x00", 0, 0);
EXPECT_ULEB128_EQ("\x01", 1, 0);
EXPECT_ULEB128_EQ("\x3f", 63, 0);
EXPECT_ULEB128_EQ("\x40", 64, 0);
EXPECT_ULEB128_EQ("\x7f", 0x7f, 0);
EXPECT_ULEB128_EQ("\x80\x01", 0x80, 0);
EXPECT_ULEB128_EQ("\x81\x01", 0x81, 0);
EXPECT_ULEB128_EQ("\x90\x01", 0x90, 0);
EXPECT_ULEB128_EQ("\xff\x01", 0xff, 0);
EXPECT_ULEB128_EQ("\x80\x02", 0x100, 0);
EXPECT_ULEB128_EQ("\x81\x02", 0x101, 0);
// Encode ULEB128 with some extra padding bytes
EXPECT_ULEB128_EQ("\x80\x00", 0, 2);
EXPECT_ULEB128_EQ("\x80\x80\x00", 0, 3);
EXPECT_ULEB128_EQ("\xff\x00", 0x7f, 2);
EXPECT_ULEB128_EQ("\xff\x80\x00", 0x7f, 3);
EXPECT_ULEB128_EQ("\x80\x81\x00", 0x80, 3);
EXPECT_ULEB128_EQ("\x80\x81\x80\x00", 0x80, 4);
#undef EXPECT_ULEB128_EQ
}
TEST(LEB128Test, DecodeULEB128) {
#define EXPECT_DECODE_ULEB128_EQ(EXPECTED, VALUE) \
do { \
unsigned ActualSize = 0; \
uint64_t Actual = decodeULEB128(reinterpret_cast<const uint8_t *>(VALUE), \
&ActualSize); \
EXPECT_EQ(sizeof(VALUE) - 1, ActualSize); \
EXPECT_EQ(EXPECTED, Actual); \
} while (0)
// Don't crash
EXPECT_EQ(0u, decodeULEB128(nullptr, nullptr, nullptr));
// Decode ULEB128
EXPECT_DECODE_ULEB128_EQ(0u, "\x00");
EXPECT_DECODE_ULEB128_EQ(1u, "\x01");
EXPECT_DECODE_ULEB128_EQ(63u, "\x3f");
EXPECT_DECODE_ULEB128_EQ(64u, "\x40");
EXPECT_DECODE_ULEB128_EQ(0x7fu, "\x7f");
EXPECT_DECODE_ULEB128_EQ(0x80u, "\x80\x01");
EXPECT_DECODE_ULEB128_EQ(0x81u, "\x81\x01");
EXPECT_DECODE_ULEB128_EQ(0x90u, "\x90\x01");
EXPECT_DECODE_ULEB128_EQ(0xffu, "\xff\x01");
EXPECT_DECODE_ULEB128_EQ(0x100u, "\x80\x02");
EXPECT_DECODE_ULEB128_EQ(0x101u, "\x81\x02");
EXPECT_DECODE_ULEB128_EQ(4294975616ULL, "\x80\xc1\x80\x80\x10");
// Decode ULEB128 with extra padding bytes
EXPECT_DECODE_ULEB128_EQ(0u, "\x80\x00");
EXPECT_DECODE_ULEB128_EQ(0u, "\x80\x80\x00");
EXPECT_DECODE_ULEB128_EQ(0x7fu, "\xff\x00");
EXPECT_DECODE_ULEB128_EQ(0x7fu, "\xff\x80\x00");
EXPECT_DECODE_ULEB128_EQ(0x80u, "\x80\x81\x00");
EXPECT_DECODE_ULEB128_EQ(0x80u, "\x80\x81\x80\x00");
#undef EXPECT_DECODE_ULEB128_EQ
}
TEST(LEB128Test, DecodeSLEB128) {
#define EXPECT_DECODE_SLEB128_EQ(EXPECTED, VALUE) \
do { \
unsigned ActualSize = 0; \
int64_t Actual = decodeSLEB128(reinterpret_cast<const uint8_t *>(VALUE), \
&ActualSize); \
EXPECT_EQ(sizeof(VALUE) - 1, ActualSize); \
EXPECT_EQ(EXPECTED, Actual); \
} while (0)
// Don't crash
EXPECT_EQ(0, decodeSLEB128(nullptr, nullptr, nullptr));
// Decode SLEB128
EXPECT_DECODE_SLEB128_EQ(0L, "\x00");
EXPECT_DECODE_SLEB128_EQ(1L, "\x01");
EXPECT_DECODE_SLEB128_EQ(63L, "\x3f");
EXPECT_DECODE_SLEB128_EQ(-64L, "\x40");
EXPECT_DECODE_SLEB128_EQ(-63L, "\x41");
EXPECT_DECODE_SLEB128_EQ(-1L, "\x7f");
EXPECT_DECODE_SLEB128_EQ(128L, "\x80\x01");
EXPECT_DECODE_SLEB128_EQ(129L, "\x81\x01");
EXPECT_DECODE_SLEB128_EQ(-129L, "\xff\x7e");
EXPECT_DECODE_SLEB128_EQ(-128L, "\x80\x7f");
EXPECT_DECODE_SLEB128_EQ(-127L, "\x81\x7f");
EXPECT_DECODE_SLEB128_EQ(64L, "\xc0\x00");
EXPECT_DECODE_SLEB128_EQ(-12345L, "\xc7\x9f\x7f");
// Decode unnormalized SLEB128 with extra padding bytes.
EXPECT_DECODE_SLEB128_EQ(0L, "\x80\x00");
EXPECT_DECODE_SLEB128_EQ(0L, "\x80\x80\x00");
EXPECT_DECODE_SLEB128_EQ(0x7fL, "\xff\x00");
EXPECT_DECODE_SLEB128_EQ(0x7fL, "\xff\x80\x00");
EXPECT_DECODE_SLEB128_EQ(0x80L, "\x80\x81\x00");
EXPECT_DECODE_SLEB128_EQ(0x80L, "\x80\x81\x80\x00");
#undef EXPECT_DECODE_SLEB128_EQ
}
TEST(LEB128Test, SLEB128Size) {
// Positive Value Testing Plan:
// (1) 128 ^ n - 1 ........ need (n+1) bytes
// (2) 128 ^ n ............ need (n+1) bytes
// (3) 128 ^ n * 63 ....... need (n+1) bytes
// (4) 128 ^ n * 64 - 1 ... need (n+1) bytes
// (5) 128 ^ n * 64 ....... need (n+2) bytes
EXPECT_EQ(1u, getSLEB128Size(0x0LL));
EXPECT_EQ(1u, getSLEB128Size(0x1LL));
EXPECT_EQ(1u, getSLEB128Size(0x3fLL));
EXPECT_EQ(1u, getSLEB128Size(0x3fLL));
EXPECT_EQ(2u, getSLEB128Size(0x40LL));
EXPECT_EQ(2u, getSLEB128Size(0x7fLL));
EXPECT_EQ(2u, getSLEB128Size(0x80LL));
EXPECT_EQ(2u, getSLEB128Size(0x1f80LL));
EXPECT_EQ(2u, getSLEB128Size(0x1fffLL));
EXPECT_EQ(3u, getSLEB128Size(0x2000LL));
EXPECT_EQ(3u, getSLEB128Size(0x3fffLL));
EXPECT_EQ(3u, getSLEB128Size(0x4000LL));
EXPECT_EQ(3u, getSLEB128Size(0xfc000LL));
EXPECT_EQ(3u, getSLEB128Size(0xfffffLL));
EXPECT_EQ(4u, getSLEB128Size(0x100000LL));
EXPECT_EQ(4u, getSLEB128Size(0x1fffffLL));
EXPECT_EQ(4u, getSLEB128Size(0x200000LL));
EXPECT_EQ(4u, getSLEB128Size(0x7e00000LL));
EXPECT_EQ(4u, getSLEB128Size(0x7ffffffLL));
EXPECT_EQ(5u, getSLEB128Size(0x8000000LL));
EXPECT_EQ(5u, getSLEB128Size(0xfffffffLL));
EXPECT_EQ(5u, getSLEB128Size(0x10000000LL));
EXPECT_EQ(5u, getSLEB128Size(0x3f0000000LL));
EXPECT_EQ(5u, getSLEB128Size(0x3ffffffffLL));
EXPECT_EQ(6u, getSLEB128Size(0x400000000LL));
EXPECT_EQ(6u, getSLEB128Size(0x7ffffffffLL));
EXPECT_EQ(6u, getSLEB128Size(0x800000000LL));
EXPECT_EQ(6u, getSLEB128Size(0x1f800000000LL));
EXPECT_EQ(6u, getSLEB128Size(0x1ffffffffffLL));
EXPECT_EQ(7u, getSLEB128Size(0x20000000000LL));
EXPECT_EQ(7u, getSLEB128Size(0x3ffffffffffLL));
EXPECT_EQ(7u, getSLEB128Size(0x40000000000LL));
EXPECT_EQ(7u, getSLEB128Size(0xfc0000000000LL));
EXPECT_EQ(7u, getSLEB128Size(0xffffffffffffLL));
EXPECT_EQ(8u, getSLEB128Size(0x1000000000000LL));
EXPECT_EQ(8u, getSLEB128Size(0x1ffffffffffffLL));
EXPECT_EQ(8u, getSLEB128Size(0x2000000000000LL));
EXPECT_EQ(8u, getSLEB128Size(0x7e000000000000LL));
EXPECT_EQ(8u, getSLEB128Size(0x7fffffffffffffLL));
EXPECT_EQ(9u, getSLEB128Size(0x80000000000000LL));
EXPECT_EQ(9u, getSLEB128Size(0xffffffffffffffLL));
EXPECT_EQ(9u, getSLEB128Size(0x100000000000000LL));
EXPECT_EQ(9u, getSLEB128Size(0x3f00000000000000LL));
EXPECT_EQ(9u, getSLEB128Size(0x3fffffffffffffffLL));
EXPECT_EQ(10u, getSLEB128Size(0x4000000000000000LL));
EXPECT_EQ(10u, getSLEB128Size(0x7fffffffffffffffLL));
EXPECT_EQ(10u, getSLEB128Size(INT64_MAX));
// Negative Value Testing Plan:
// (1) - 128 ^ n - 1 ........ need (n+1) bytes
// (2) - 128 ^ n ............ need (n+1) bytes
// (3) - 128 ^ n * 63 ....... need (n+1) bytes
// (4) - 128 ^ n * 64 ....... need (n+1) bytes (different from positive one)
// (5) - 128 ^ n * 65 - 1 ... need (n+2) bytes (if n > 0)
// (6) - 128 ^ n * 65 ....... need (n+2) bytes
EXPECT_EQ(1u, getSLEB128Size(0x0LL));
EXPECT_EQ(1u, getSLEB128Size(-0x1LL));
EXPECT_EQ(1u, getSLEB128Size(-0x3fLL));
EXPECT_EQ(1u, getSLEB128Size(-0x40LL));
EXPECT_EQ(1u, getSLEB128Size(-0x40LL)); // special case
EXPECT_EQ(2u, getSLEB128Size(-0x41LL));
EXPECT_EQ(2u, getSLEB128Size(-0x7fLL));
EXPECT_EQ(2u, getSLEB128Size(-0x80LL));
EXPECT_EQ(2u, getSLEB128Size(-0x1f80LL));
EXPECT_EQ(2u, getSLEB128Size(-0x2000LL));
EXPECT_EQ(3u, getSLEB128Size(-0x207fLL));
EXPECT_EQ(3u, getSLEB128Size(-0x2080LL));
EXPECT_EQ(3u, getSLEB128Size(-0x3fffLL));
EXPECT_EQ(3u, getSLEB128Size(-0x4000LL));
EXPECT_EQ(3u, getSLEB128Size(-0xfc000LL));
EXPECT_EQ(3u, getSLEB128Size(-0x100000LL));
EXPECT_EQ(4u, getSLEB128Size(-0x103fffLL));
EXPECT_EQ(4u, getSLEB128Size(-0x104000LL));
EXPECT_EQ(4u, getSLEB128Size(-0x1fffffLL));
EXPECT_EQ(4u, getSLEB128Size(-0x200000LL));
EXPECT_EQ(4u, getSLEB128Size(-0x7e00000LL));
EXPECT_EQ(4u, getSLEB128Size(-0x8000000LL));
EXPECT_EQ(5u, getSLEB128Size(-0x81fffffLL));
EXPECT_EQ(5u, getSLEB128Size(-0x8200000LL));
EXPECT_EQ(5u, getSLEB128Size(-0xfffffffLL));
EXPECT_EQ(5u, getSLEB128Size(-0x10000000LL));
EXPECT_EQ(5u, getSLEB128Size(-0x3f0000000LL));
EXPECT_EQ(5u, getSLEB128Size(-0x400000000LL));
EXPECT_EQ(6u, getSLEB128Size(-0x40fffffffLL));
EXPECT_EQ(6u, getSLEB128Size(-0x410000000LL));
EXPECT_EQ(6u, getSLEB128Size(-0x7ffffffffLL));
EXPECT_EQ(6u, getSLEB128Size(-0x800000000LL));
EXPECT_EQ(6u, getSLEB128Size(-0x1f800000000LL));
EXPECT_EQ(6u, getSLEB128Size(-0x20000000000LL));
EXPECT_EQ(7u, getSLEB128Size(-0x207ffffffffLL));
EXPECT_EQ(7u, getSLEB128Size(-0x20800000000LL));
EXPECT_EQ(7u, getSLEB128Size(-0x3ffffffffffLL));
EXPECT_EQ(7u, getSLEB128Size(-0x40000000000LL));
EXPECT_EQ(7u, getSLEB128Size(-0xfc0000000000LL));
EXPECT_EQ(7u, getSLEB128Size(-0x1000000000000LL));
EXPECT_EQ(8u, getSLEB128Size(-0x103ffffffffffLL));
EXPECT_EQ(8u, getSLEB128Size(-0x1040000000000LL));
EXPECT_EQ(8u, getSLEB128Size(-0x1ffffffffffffLL));
EXPECT_EQ(8u, getSLEB128Size(-0x2000000000000LL));
EXPECT_EQ(8u, getSLEB128Size(-0x7e000000000000LL));
EXPECT_EQ(8u, getSLEB128Size(-0x80000000000000LL));
EXPECT_EQ(9u, getSLEB128Size(-0x81ffffffffffffLL));
EXPECT_EQ(9u, getSLEB128Size(-0x82000000000000LL));
EXPECT_EQ(9u, getSLEB128Size(-0xffffffffffffffLL));
EXPECT_EQ(9u, getSLEB128Size(-0x100000000000000LL));
EXPECT_EQ(9u, getSLEB128Size(-0x3f00000000000000LL));
EXPECT_EQ(9u, getSLEB128Size(-0x4000000000000000LL));
EXPECT_EQ(10u, getSLEB128Size(-0x40ffffffffffffffLL));
EXPECT_EQ(10u, getSLEB128Size(-0x4100000000000000LL));
EXPECT_EQ(10u, getSLEB128Size(-0x7fffffffffffffffLL));
EXPECT_EQ(10u, getSLEB128Size(-0x8000000000000000LL));
EXPECT_EQ(10u, getSLEB128Size(INT64_MIN));
}
TEST(LEB128Test, ULEB128Size) {
// Testing Plan:
// (1) 128 ^ n ............ need (n+1) bytes
// (2) 128 ^ n * 64 ....... need (n+1) bytes
// (3) 128 ^ (n+1) - 1 .... need (n+1) bytes
EXPECT_EQ(1u, getULEB128Size(0)); // special case
EXPECT_EQ(1u, getULEB128Size(0x1ULL));
EXPECT_EQ(1u, getULEB128Size(0x40ULL));
EXPECT_EQ(1u, getULEB128Size(0x7fULL));
EXPECT_EQ(2u, getULEB128Size(0x80ULL));
EXPECT_EQ(2u, getULEB128Size(0x2000ULL));
EXPECT_EQ(2u, getULEB128Size(0x3fffULL));
EXPECT_EQ(3u, getULEB128Size(0x4000ULL));
EXPECT_EQ(3u, getULEB128Size(0x100000ULL));
EXPECT_EQ(3u, getULEB128Size(0x1fffffULL));
EXPECT_EQ(4u, getULEB128Size(0x200000ULL));
EXPECT_EQ(4u, getULEB128Size(0x8000000ULL));
EXPECT_EQ(4u, getULEB128Size(0xfffffffULL));
EXPECT_EQ(5u, getULEB128Size(0x10000000ULL));
EXPECT_EQ(5u, getULEB128Size(0x400000000ULL));
EXPECT_EQ(5u, getULEB128Size(0x7ffffffffULL));
EXPECT_EQ(6u, getULEB128Size(0x800000000ULL));
EXPECT_EQ(6u, getULEB128Size(0x20000000000ULL));
EXPECT_EQ(6u, getULEB128Size(0x3ffffffffffULL));
EXPECT_EQ(7u, getULEB128Size(0x40000000000ULL));
EXPECT_EQ(7u, getULEB128Size(0x1000000000000ULL));
EXPECT_EQ(7u, getULEB128Size(0x1ffffffffffffULL));
EXPECT_EQ(8u, getULEB128Size(0x2000000000000ULL));
EXPECT_EQ(8u, getULEB128Size(0x80000000000000ULL));
EXPECT_EQ(8u, getULEB128Size(0xffffffffffffffULL));
EXPECT_EQ(9u, getULEB128Size(0x100000000000000ULL));
EXPECT_EQ(9u, getULEB128Size(0x4000000000000000ULL));
EXPECT_EQ(9u, getULEB128Size(0x7fffffffffffffffULL));
EXPECT_EQ(10u, getULEB128Size(0x8000000000000000ULL));
EXPECT_EQ(10u, getULEB128Size(UINT64_MAX));
}
} // anonymous namespace