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_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