c++ - 在C++中获取调用函数的名称、行号和文件名

Question

我已经编写了以下代码来在我的日志文件中写入日志。这段代码可以很好地记录消息，但现在我必须将它集成到多个文件中，我需要调用者的文件路径、调用者函数名称和行号。

请帮助我实现这一目标。

#include "Source.h"

bool CLogManager::fileOpenError = false;
std::string CLogManager::logFileName = "";
CLogManager* CLogManager::logManager = NULL;
FILE* CLogManager::file = NULL;

CLogManager :: CLogManager(){}
CLogManager :: ~CLogManager()
{
    if (file)
        fclose(file);
}
CLogManager* CLogManager::getInstance()
{
    if(logManager==NULL)
    {
        logManager = new CLogManager();
        logFileName = currentDateTime();
    }
    return logManager;
}
const std::string CLogManager::currentDateTime()
{
    time_t now = time(0);
    char currTime[30];
    strftime(currTime, sizeof(currTime), "Log_%Y_%m_%dT%H_%M_%S.xml", localtime(&now));
    return currTime;
}
void CLogManager::Log (char *message)
{
    file = fopen(logFileName.c_str(), "a+");
    if(file == NULL) 
    {
        if(fileOpenError == false)
        {
            std::cout << "There was an error While opening Log File."<<std::endl;
            fileOpenError = true;
        }
        return;
    }
    fputs(message, file);
    fputs("\n", file);
}

int main ()
{
    CLogManager::getInstance();
    CLogManager::Log("Sorry some error occured");
    CLogManager::Log("Please try again");
    CLogManager::Log("Wait");
    return 0;
}

Answer 1

从 C++ 20 开始，您可以使用 std::source_location。

来自 CPPReference.com 上的示例:

#include <iostream>
#include <string_view>
#include <source_location>
 
void log(const std::string_view message,
         const std::source_location location = 
               std::source_location::current())
{
    std::cout << "file: "
              << location.file_name() << "("
              << location.line() << ":"
              << location.column() << ") `"
              << location.function_name() << "`: "
              << message << '\n';
}
 
template <typename T> void fun(T x)
{
    log(x);
}
 
int main(int, char*[])
{
    log("Hello world!");
    fun("Hello C++20!");
}

输出:

file: main.cpp(23:8) `int main(int, char**)`: Hello world!
file: main.cpp(18:8) `void fun(T) [with T = const char*]`: Hello C++20!