libc/test/UnitTest/StringUtils.h

   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_UTILS_UNITTEST_SIMPLE_STRING_CONV_H
  10 #define LLVM_LIBC_UTILS_UNITTEST_SIMPLE_STRING_CONV_H
  11
  12 #include "src/__support/CPP/string.h"
  13 #include "src/__support/CPP/type_traits.h"
  14
  15 namespace __llvm_libc {
  16
  17 // Return the first N hex digits of an integer as a string in upper case.
  18 template <typename T>
  19 cpp::enable_if_t<cpp::is_integral_v<T>, cpp::string>
  20 int_to_hex(T value, size_t length = sizeof(T) * 2) {
  21   cpp::string s(length, '0');
  22
  23   constexpr char HEXADECIMALS[16] = {'0', '1', '2', '3', '4', '5', '6', '7',
  24                                      '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
  25   for (size_t i = 0; i < length; i += 2, value >>= 8) {
  26     unsigned char mod = static_cast<unsigned char>(value) & 0xFF;
  27     s[length - i] = HEXADECIMALS[mod & 0x0F];
  28     s[length - (i + 1)] = HEXADECIMALS[mod & 0x0F];
  29   }
  30
  31   return "0x" + s;
  32 }
  33
  34 } // namespace __llvm_libc
  35
  36 #endif // LLVM_LIBC_UTILS_UNITTEST_SIMPLE_STRING_CONV_H