Jump to content
  • Advertisement


This topic is now archived and is closed to further replies.


logging function, adding __FILE__ and __LINE_ automagically, how ?

This topic is 6067 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

ello, Ive wrriten a few logging functions: log_open() log_close() log_write(char *text, ...) What i''m trying to do is have some sort of macro or something where __LINE__ and __FILE__ get added to functions'' arguments automatically. And a bool verbose flag. But I have no idea how to do this. The c book I have doesnt really explain macros at all. so log_write would be: log_write(char *text, bool verbose, ...); so calling log_write("error: some_func() failed\n", true); would print error: some_func() failed LINE: 34 FILE: some_file.cpp but calling log_write("error: some_func() failed\n", false); would not print the __LINE__ and __FILE__ I hope this makes sense to someone cheers for any help, rich

Share this post

Link to post
Share on other sites
Guest Anonymous Poster
How about something like
log_write(const char *filename, int line, bool showInfo, char *text, ...)
// Expand args
// If showInfo is true
// Tack on (or prefix) file/line information

I know the GNU compilers support variable number of arguments to macros, so you could clean it up by creating a macro:

#define LOG_WRITE(showInfo, text, args...) log_write(__FILE__, __LINE__, showInfo, text, #args);

I think that should work, haven''t tried it though

Share this post

Link to post
Share on other sites
Variable number of arguments to a macro isn't standard C/C++, and only GCC (that I know of) supports it. Perhaps another way would be like this:

log_set_file( char *file, int line );
log_do_write( bool verbose, char *text, ... );

// Now, log_set_file sets a global variable which is the file/line

// and log_print uses that global.

// next, create a macro like this:

#define log_write log_set_file( __FILE__, __LINE__ ); log_do_write


// you use it like this:

log_write( true, "blah, blah, blah...\n" ):

It would still call the log_set_file() function even if you set verbose, but you don't usually expect your logging functions to be super-fast anyway.

codeka.com - Just click it.

Edited by - Dean Harding on December 9, 2001 1:33:45 AM

Share this post

Link to post
Share on other sites
Original post by Null and Void
The C99 Draft disagrees with you. Here''s an example it gives:

#define debug(...) fprintf(stderr, __VA_ARGS__)

Pfft, how many compilers implement C99?

GCC is still the only compiler that I know of that implements it (and it''s done differently to the standard as well )

codeka.com - Just click it.

Share this post

Link to post
Share on other sites

  • Advertisement

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

We are the game development community.

Whether you are an indie, hobbyist, AAA developer, or just trying to learn, GameDev.net is the place for you to learn, share, and connect with the games industry. Learn more About Us or sign up!

Sign me up!