1/**
2 * Copyright (c) 2021-2022 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16#ifndef LIBPANDABASE_UTILS_UTILS_H
17#define LIBPANDABASE_UTILS_UTILS_H
18
19#include <exception>
20#include <string>
21
22namespace panda {
23// ----------------------------------------------------------------------------
24// General helper functions
25
26// Returns the value (0 .. 15) of a hexadecimal character c.
27// If c is not a legal hexadecimal character, returns a value < 0.
28inline uint32_t HexValue(uint32_t c)
29{
30    constexpr uint32_t BASE16 = 16;
31    constexpr uint32_t BASE10 = 10;
32    constexpr uint32_t MASK = 0x20;
33
34    c -= '0';
35    if (static_cast<unsigned>(c) < BASE10) {
36        return c;
37    }
38    // NOLINTNEXTLINE(hicpp-signed-bitwise)
39    c = (c | MASK) - ('a' - '0');
40    if (static_cast<unsigned>(c) < (BASE16 - BASE10)) {
41        return c + BASE10;
42    }
43    return -1;
44}
45
46// General helper class
47class UnreachableException : public std::exception {
48public:
49    explicit UnreachableException(const char *msg) : msg_(msg) {}
50    explicit UnreachableException(const std::string_view &msg) : msg_(msg) {}
51    const char *what() const noexcept override
52    {
53        return msg_.c_str();
54    }
55
56private:
57    std::string msg_;
58};
59
60}  // namespace panda
61
62#endif  // LIBPANDABASE_UTILS_UTILS_H
63