src/common/format.hpp

   1 /*
   2  * Copyright (C) 2022 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-only
   5  *
   6  */
   7 #ifndef LTTNG_FORMAT_H
   8 #define LTTNG_FORMAT_H
   9
  10 #include <common/macros.hpp>
  11
  12 #include <cxxabi.h>
  13 #include <string>
  14 #include <utility>
  15
  16 DIAGNOSTIC_PUSH
  17 DIAGNOSTIC_IGNORE_SUGGEST_ATTRIBUTE_FORMAT
  18 DIAGNOSTIC_IGNORE_DUPLICATED_BRANCHES
  19 #define FMT_HEADER_ONLY
  20 #include <vendor/fmt/core.h>
  21 DIAGNOSTIC_POP
  22
  23 /*
  24  * Due to a bug in g++ < 7.1, this specialization must be enclosed in the fmt namespace,
  25  * see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56480.
  26  */
  27 namespace fmt {
  28 template <>
  29 struct formatter<std::type_info> : formatter<std::string> {
  30         template <typename FormatContextType>
  31         typename FormatContextType::iterator format(const std::type_info& type_info,
  32                                                     FormatContextType& ctx)
  33         {
  34                 int status;
  35                 auto demangled_name =
  36                         abi::__cxa_demangle(type_info.name(), nullptr, nullptr, &status);
  37                 auto it = status == 0 ? formatter<std::string>::format(demangled_name, ctx) :
  38                                         formatter<std::string>::format(type_info.name(), ctx);
  39
  40                 free(demangled_name);
  41                 return it;
  42         }
  43 };
  44 } /* namespace fmt */
  45
  46 namespace lttng {
  47 template <typename... FormattingArguments>
  48 std::string format(FormattingArguments&&...args)
  49 {
  50         try {
  51                 return fmt::format(std::forward<FormattingArguments>(args)...);
  52         } catch (const fmt::format_error& ex) {
  53                 return std::string("Failed to format string: ") += ex.what();
  54         }
  55 }
  56 } /* namespace lttng */
  57
  58 #endif /* LTTNG_FORMAT_H */