[lttng-tools.git] / src / common / format.hpp

/*
 * Copyright (C) 2022 Jérémie Galarneau <jeremie.galarneau@efficios.com>
 *
 * SPDX-License-Identifier: LGPL-2.1-only
 *
 */
#ifndef LTTNG_FORMAT_H
#define LTTNG_FORMAT_H

#include <common/macros.hpp>

#include <cxxabi.h>
#include <string>
#include <utility>

DIAGNOSTIC_PUSH
DIAGNOSTIC_IGNORE_SUGGEST_ATTRIBUTE_FORMAT
DIAGNOSTIC_IGNORE_DUPLICATED_BRANCHES
#define FMT_HEADER_ONLY
#include <vendor/fmt/core.h>
DIAGNOSTIC_POP

#include <common/make-unique-wrapper.hpp>

/*
 * Due to a bug in g++ < 7.1, this specialization must be enclosed in the fmt namespace,
 * see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56480.
 */
namespace fmt {
template <>
struct formatter<std::type_info> : formatter<std::string> {
	template <typename FormatContextType>
	typename FormatContextType::iterator format(const std::type_info& type_info,
						    FormatContextType& ctx)
	{
		int status;
		/*
		 * The documentation of __cxa_demangle mentions the returned string is allocated
		 * using malloc (not new), hence the use of lttng::memory::free.
		 */
		const auto demangled_name = lttng::make_unique_wrapper<char, lttng::memory::free>(
			abi::__cxa_demangle(type_info.name(), nullptr, nullptr, &status));

		auto it = status == 0 ? formatter<std::string>::format(demangled_name.get(), ctx) :
					formatter<std::string>::format(type_info.name(), ctx);
		return it;
	}
};
} /* namespace fmt */

namespace lttng {
template <typename... FormattingArguments>
std::string format(FormattingArguments&&...args)
{
	try {
		return fmt::format(std::forward<FormattingArguments>(args)...);
	} catch (const fmt::format_error& ex) {
		return std::string("Failed to format string: ") += ex.what();
	}
}
} /* namespace lttng */

#endif /* LTTNG_FORMAT_H */
Commit	Line	Data
	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	#include <common/make-unique-wrapper.hpp>
	24
	25	/*
	26	* Due to a bug in g++ < 7.1, this specialization must be enclosed in the fmt namespace,
	27	* see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56480.
	28	*/
	29	namespace fmt {
	30	template <>
	31	struct formatter<std::type_info> : formatter<std::string> {
	32	template <typename FormatContextType>
	33	typename FormatContextType::iterator format(const std::type_info& type_info,
	34	FormatContextType& ctx)
	35	{
	36	int status;
	37	/*
	38	* The documentation of __cxa_demangle mentions the returned string is allocated
	39	* using malloc (not new), hence the use of lttng::memory::free.
	40	*/
	41	const auto demangled_name = lttng::make_unique_wrapper<char, lttng::memory::free>(
	42	abi::__cxa_demangle(type_info.name(), nullptr, nullptr, &status));
	43
	44	auto it = status == 0 ? formatter<std::string>::format(demangled_name.get(), ctx) :
	45	formatter<std::string>::format(type_info.name(), ctx);
	46	return it;
	47	}
	48	};
	49	} /* namespace fmt */
	50
	51	namespace lttng {
	52	template <typename... FormattingArguments>
	53	std::string format(FormattingArguments&&...args)
	54	{
	55	try {
	56	return fmt::format(std::forward<FormattingArguments>(args)...);
	57	} catch (const fmt::format_error& ex) {
	58	return std::string("Failed to format string: ") += ex.what();
	59	}
	60	}
	61	} /* namespace lttng */
	62
	63	#endif /* LTTNG_FORMAT_H */