Trace Macro

[monarch_dodra]

I have a Trace.h file which is include in pretty much all my files, which contains the following:

#ifndef TRACE_H_INCLUDED
#define TRACE_H_INCLUDED

#include <iostream>
#include <fstream>

static std::ofstream log_stream("output.log");

#define TRACE(ARG) if(true){log_stream << __FILE << " at line " << __LINE << ARG << std::endl;} else void(0)

#endif // TRACE_H_INCLUDED

Basically, the idea is I can log stuff to a file as my program runs.

The problem is that after running my program, I realize that a good amount of my traces are missing, most are out of order, and finally, a lot of them are missing the beginning or end of the message, like this:

/main.cpp at line 28 there
ne 33 here
/EnColor.h at line 33 hello

What am I doing wrong? I thought std::endl was supposed to flush my stream, doesn't that mean this shouldn't happen?

Do I have a broken declaration of log_stream, and actually have several handles on the same file?

Is this an ofstream problem, or what? What would you guys do?

PS: Codeblocks with mingw on winxp32
PS2, replacing log_stream with the standard std::cout works fine, but that is not what I want

[ZuK]

Do I have a broken declaration of log_stream, and actually have several handles on the same file?

Yes you will have a more than one instance of log_stream. One for each module that you have included that header.
That's how static variables work. They are only visible from inside the module they are declared. That's why the linker doesn't complain.

Declare it extern in the header and create only one in your main module.

Kurt

[monarch_dodra]

Yes you will have a more than one instance of log_stream. One for each module that you have included that header.
That's how static variables work. They are only visible from inside the module they are declared. That's why the linker doesn't complain.

Declare it extern in the header and create only one in your main module.

Kurt

Wow, after 1.5 years of coding C++ proffesionally, and I didn't even know that. Now I do though.

Thanks a lot.

That's what I get for never having used a global