1 // Copyright (c) 2019, Paul Dreik
2 // For the license information refer to format.h.
3
4 #include <fmt/chrono.h>
5
6 #include <cstdint>
7
8 #include "fuzzer-common.h"
9
10 template <typename Period, typename Rep>
invoke_inner(fmt::string_view format_str,Rep rep)11 void invoke_inner(fmt::string_view format_str, Rep rep) {
12 auto value = std::chrono::duration<Rep, Period>(rep);
13 try {
14 #if FMT_FUZZ_FORMAT_TO_STRING
15 std::string message = fmt::format(format_str, value);
16 #else
17 auto buf = fmt::memory_buffer();
18 fmt::format_to(std::back_inserter(buf), format_str, value);
19 #endif
20 } catch (std::exception&) {
21 }
22 }
23
24 // Rep is a duration's representation type.
25 template <typename Rep>
invoke_outer(const uint8_t * data,size_t size,int period)26 void invoke_outer(const uint8_t* data, size_t size, int period) {
27 // Always use a fixed location of the data.
28 static_assert(sizeof(Rep) <= fixed_size, "fixed size is too small");
29 if (size <= fixed_size + 1) return;
30
31 const Rep rep = assign_from_buf<Rep>(data);
32 data += fixed_size;
33 size -= fixed_size;
34
35 // data is already allocated separately in libFuzzer so reading past the end
36 // will most likely be detected anyway.
37 const auto format_str = fmt::string_view(as_chars(data), size);
38
39 // yocto, zepto, zetta and yotta are not handled.
40 switch (period) {
41 case 1:
42 invoke_inner<std::atto>(format_str, rep);
43 break;
44 case 2:
45 invoke_inner<std::femto>(format_str, rep);
46 break;
47 case 3:
48 invoke_inner<std::pico>(format_str, rep);
49 break;
50 case 4:
51 invoke_inner<std::nano>(format_str, rep);
52 break;
53 case 5:
54 invoke_inner<std::micro>(format_str, rep);
55 break;
56 case 6:
57 invoke_inner<std::milli>(format_str, rep);
58 break;
59 case 7:
60 invoke_inner<std::centi>(format_str, rep);
61 break;
62 case 8:
63 invoke_inner<std::deci>(format_str, rep);
64 break;
65 case 9:
66 invoke_inner<std::deca>(format_str, rep);
67 break;
68 case 10:
69 invoke_inner<std::kilo>(format_str, rep);
70 break;
71 case 11:
72 invoke_inner<std::mega>(format_str, rep);
73 break;
74 case 12:
75 invoke_inner<std::giga>(format_str, rep);
76 break;
77 case 13:
78 invoke_inner<std::tera>(format_str, rep);
79 break;
80 case 14:
81 invoke_inner<std::peta>(format_str, rep);
82 break;
83 case 15:
84 invoke_inner<std::exa>(format_str, rep);
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 <= 4) return 0;
91
92 const auto representation = data[0];
93 const auto period = data[1];
94 data += 2;
95 size -= 2;
96
97 switch (representation) {
98 case 1:
99 invoke_outer<char>(data, size, period);
100 break;
101 case 2:
102 invoke_outer<signed char>(data, size, period);
103 break;
104 case 3:
105 invoke_outer<unsigned char>(data, size, period);
106 break;
107 case 4:
108 invoke_outer<short>(data, size, period);
109 break;
110 case 5:
111 invoke_outer<unsigned short>(data, size, period);
112 break;
113 case 6:
114 invoke_outer<int>(data, size, period);
115 break;
116 case 7:
117 invoke_outer<unsigned int>(data, size, period);
118 break;
119 case 8:
120 invoke_outer<long>(data, size, period);
121 break;
122 case 9:
123 invoke_outer<unsigned long>(data, size, period);
124 break;
125 case 10:
126 invoke_outer<float>(data, size, period);
127 break;
128 case 11:
129 invoke_outer<double>(data, size, period);
130 break;
131 case 12:
132 invoke_outer<long double>(data, size, period);
133 break;
134 }
135 return 0;
136 }
137