1 // Copyright (c) 2019, Paul Dreik
2 // For the license information refer to format.h.
3
4 #include <fmt/format.h>
5
6 #include <cstdint>
7 #include <exception>
8 #include <string>
9
10 #include "fuzzer-common.h"
11
12 template <typename Item1, typename Item2>
invoke_fmt(const uint8_t * data,size_t size)13 void invoke_fmt(const uint8_t* data, size_t size) {
14 static_assert(sizeof(Item1) <= fixed_size, "size1 exceeded");
15 static_assert(sizeof(Item2) <= fixed_size, "size2 exceeded");
16 if (size <= fixed_size + fixed_size) return;
17
18 const Item1 item1 = assign_from_buf<Item1>(data);
19 data += fixed_size;
20 size -= fixed_size;
21
22 const Item2 item2 = assign_from_buf<Item2>(data);
23 data += fixed_size;
24 size -= fixed_size;
25
26 auto format_str = fmt::string_view(as_chars(data), size);
27 #if FMT_FUZZ_FORMAT_TO_STRING
28 std::string message = fmt::format(format_str, item1, item2);
29 #else
30 auto buf = fmt::memory_buffer();
31 fmt::format_to(std::back_inserter(buf), format_str, item1, item2);
32 #endif
33 }
34
35 // For dynamic dispatching to an explicit instantiation.
invoke(int index,Callback callback)36 template <typename Callback> void invoke(int index, Callback callback) {
37 switch (index) {
38 case 0:
39 callback(bool());
40 break;
41 case 1:
42 callback(char());
43 break;
44 case 2:
45 using sc = signed char;
46 callback(sc());
47 break;
48 case 3:
49 using uc = unsigned char;
50 callback(uc());
51 break;
52 case 4:
53 callback(short());
54 break;
55 case 5:
56 using us = unsigned short;
57 callback(us());
58 break;
59 case 6:
60 callback(int());
61 break;
62 case 7:
63 callback(unsigned());
64 break;
65 case 8:
66 callback(long());
67 break;
68 case 9:
69 using ul = unsigned long;
70 callback(ul());
71 break;
72 case 10:
73 callback(float());
74 break;
75 case 11:
76 callback(double());
77 break;
78 case 12:
79 using LD = long double;
80 callback(LD());
81 break;
82 case 13:
83 using ptr = void*;
84 callback(ptr());
85 break;
86 }
87 }
88
LLVMFuzzerTestOneInput(const uint8_t * data,size_t size)89 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
90 if (size <= 3) return 0;
91
92 // Switch types depending on the first byte of the input.
93 const auto type1 = data[0] & 0x0F;
94 const auto type2 = (data[0] & 0xF0) >> 4;
95 data++;
96 size--;
97 try {
98 invoke(type1, [=](auto param1) {
99 invoke(type2, [=](auto param2) {
100 invoke_fmt<decltype(param1), decltype(param2)>(data, size);
101 });
102 });
103 } catch (std::exception&) {
104 }
105 return 0;
106 }
107