xref: /aosp_15_r20/external/llvm-libc/test/UnitTest/StringUtils.h (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
1 //===-- String utils for matchers -------------------------------*- C++ -*-===//
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 #ifndef LLVM_LIBC_TEST_UNITTEST_STRINGUTILS_H
10 #define LLVM_LIBC_TEST_UNITTEST_STRINGUTILS_H
11 
12 #include "src/__support/CPP/string.h"
13 #include "src/__support/CPP/type_traits.h"
14 #include "src/__support/big_int.h"
15 #include "src/__support/macros/config.h"
16 
17 namespace LIBC_NAMESPACE_DECL {
18 
19 // Return the first N hex digits of an integer as a string in upper case.
20 template <typename T>
21 cpp::enable_if_t<cpp::is_integral_v<T> || is_big_int_v<T>, cpp::string>
22 int_to_hex(T value, size_t length = sizeof(T) * 2) {
23   cpp::string s(length, '0');
24 
25   constexpr char HEXADECIMALS[16] = {'0', '1', '2', '3', '4', '5', '6', '7',
26                                      '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
27   for (size_t i = 0; i < length; i += 2, value >>= 8) {
28     unsigned char mod = static_cast<unsigned char>(value) & 0xFF;
29     s[length - i] = HEXADECIMALS[mod & 0x0F];
30     s[length - (i + 1)] = HEXADECIMALS[mod & 0x0F];
31   }
32 
33   return "0x" + s;
34 }
35 
36 } // namespace LIBC_NAMESPACE_DECL
37 
38 #endif // LLVM_LIBC_TEST_UNITTEST_STRINGUTILS_H
39