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/**
* Copyright (C) 2019-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include <cstdint>
#include <string>
#if !defined(_MSC_VER) && !defined(__clang__) // not windows or clang
#include <experimental/source_location>
#endif // windows
#include <fmt/format.h>
namespace mongo {
/**
* A SourceLocation is a constexpr type that captures a source location
*
* This class mimics the api signature of C++20 std::source_location
*
* It is intended to be constructed with MONGO_SOURCE_LOCATION() below.
*/
class SourceLocation {
public:
constexpr SourceLocation(uint_least32_t line,
uint_least32_t column,
const char* file_name,
const char* function_name) noexcept
: _line(line), _column(column), _file_name(file_name), _function_name(function_name) {}
constexpr uint_least32_t line() const noexcept {
return _line;
}
constexpr uint_least32_t column() const noexcept {
return _column;
}
constexpr const char* file_name() const noexcept {
return _file_name;
}
constexpr const char* function_name() const noexcept {
return _function_name;
}
private:
uint_least32_t _line;
uint_least32_t _column; // column will be 0 if there isn't compiler support
const char* _file_name;
const char* _function_name;
};
/**
* SourceLocationHolder is intended for convenient io of SourceLocation
*/
class SourceLocationHolder {
public:
constexpr SourceLocationHolder(SourceLocation&& loc) noexcept
: _loc(std::forward<SourceLocation>(loc)) {}
constexpr uint_least32_t line() const noexcept {
return _loc.line();
}
constexpr uint_least32_t column() const noexcept {
return _loc.column();
}
constexpr const char* file_name() const noexcept {
return _loc.file_name();
}
constexpr const char* function_name() const noexcept {
return _loc.function_name();
}
std::string toString() const {
using namespace fmt::literals;
return R"({{fileName:"{}", line:{}, functionName:"{}"}})"_format(
_loc.file_name(), _loc.line(), _loc.function_name());
}
friend std::ostream& operator<<(std::ostream& out, const SourceLocationHolder& context) {
return out << context.toString();
}
private:
SourceLocation _loc;
};
/**
* MONGO_SOURCE_LOCATION() either:
* - captures std::experimental::source_location::current()
* - makes a best effort with various macros and local static constants
*
* Since __FUNCSIG__ and __PRETTY_FUNCTION__ aren't defined outside of functions, there is also
* MONGO_SOURCE_LOCATION_NO_FUNC() for use with a default member initializatizer or constant
* initialization.
*/
#if defined(_MSC_VER) // windows
// MSVC does not have any of N4810 yet. (see
// https://developercommunity.visualstudio.com/idea/354069/implement-c-library-fundamentals-ts-v2.html)
#define MONGO_SOURCE_LOCATION() ::mongo::SourceLocation(__LINE__, 0ul, __FILE__, __func__)
#define MONGO_SOURCE_LOCATION_NO_FUNC() ::mongo::SourceLocation(__LINE__, 0ul, __FILE__, "")
#elif defined(__clang__) // windows -> clang
// Clang got __builtin_FILE et al as of 8.0.1 (see https://reviews.llvm.org/D37035)
#define MONGO_SOURCE_LOCATION() ::mongo::SourceLocation(__LINE__, 0ul, __FILE__, __func__)
#define MONGO_SOURCE_LOCATION_NO_FUNC() ::mongo::SourceLocation(__LINE__, 0ul, __FILE__, "")
#elif defined(__GNUG__) // clang -> gcc
constexpr auto toSourceLocation(std::experimental::source_location loc) {
// Note that std::experimental::source_location captures __func__, not __PRETTY_FUNC__
return SourceLocation(loc.line(), loc.column(), loc.file_name(), loc.function_name());
}
#define MONGO_SOURCE_LOCATION() \
::mongo::toSourceLocation(std::experimental::source_location::current())
#define MONGO_SOURCE_LOCATION_NO_FUNC() \
::mongo::toSourceLocation(std::experimental::source_location::current())
#else // gcc -> ?
#error "Unknown compiler, cannot approximate std::source_location"
#endif // ?
} // namespace mongo
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