1//===-- strtointeger_fuzz.cpp ---------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8///
9/// Fuzzing test for llvm-libc atof implementation.
10///
11//===----------------------------------------------------------------------===//
12#include "src/stdlib/atoi.h"
13#include "src/stdlib/atol.h"
14#include "src/stdlib/atoll.h"
15#include "src/stdlib/strtol.h"
16#include "src/stdlib/strtoll.h"
17#include "src/stdlib/strtoul.h"
18#include "src/stdlib/strtoull.h"
19#include <stddef.h>
20#include <stdint.h>
21
22// This takes the randomized bytes in data and interprets the first byte as the
23// base for the string to integer conversion and the rest of them as a string to
24// be passed to the string to integer conversion.
25extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
26 size_t container_size = 0;
27 if (size == 0) {
28 container_size = 1;
29 } else {
30 container_size = size;
31 }
32 uint8_t *container = new uint8_t[container_size];
33 if (!container)
34 __builtin_trap();
35
36 int base = 0;
37 if (size > 0) {
38 base = data[0] % 36;
39 base = base + ((base == 0) ? 0 : 1);
40 }
41 for (size_t i = 1; i < size; ++i) {
42 container[i - 1] = data[i];
43 }
44
45 container[container_size - 1] = '\0'; // Add null terminator to container.
46
47 const char *str_ptr = reinterpret_cast<const char *>(container);
48
49 char *out_ptr = nullptr;
50
51 auto volatile atoi_output = LIBC_NAMESPACE::atoi(str_ptr);
52 auto volatile atol_output = LIBC_NAMESPACE::atol(str_ptr);
53 auto volatile atoll_output = LIBC_NAMESPACE::atoll(str_ptr);
54 auto volatile strtol_output = LIBC_NAMESPACE::strtol(str_ptr, &out_ptr, base);
55 if (str_ptr + container_size - 1 < out_ptr)
56 __builtin_trap();
57 auto volatile strtoll_output =
58 LIBC_NAMESPACE::strtoll(str_ptr, &out_ptr, base);
59 if (str_ptr + container_size - 1 < out_ptr)
60 __builtin_trap();
61 auto volatile strtoul_output =
62 LIBC_NAMESPACE::strtoul(str_ptr, &out_ptr, base);
63 if (str_ptr + container_size - 1 < out_ptr)
64 __builtin_trap();
65 auto volatile strtoull_output =
66 LIBC_NAMESPACE::strtoull(str_ptr, &out_ptr, base);
67 if (str_ptr + container_size - 1 < out_ptr)
68 __builtin_trap();
69
70 // If atoi is non-zero and the base is at least 10
71 if (atoi_output != 0 && base >= 10) {
72 // Then all of the other functions should output non-zero values as well.
73 // This is a trivial check meant to silence the "unused variable" warnings.
74 if (atol_output == 0 || atoll_output == 0 || strtol_output == 0 ||
75 strtoll_output == 0 || strtoul_output == 0 || strtoull_output == 0) {
76 __builtin_trap();
77 }
78 }
79
80 delete[] container;
81 return 0;
82}
83

source code of libc/fuzzing/stdlib/strtointeger_fuzz.cpp