Asterisk Source code

Hi experts,
In asterisk source code (such as chan_sip.c file), there are alot of code like these:
I think there are some file in which the logs are recored to. Is it true?
because i turn on asterisk debug "core set debud chanel all " but i didn’t any logs.
I want trace some lines code in source code (such as chan_sip.c), how can i do it?
In other words How can i trace some my code in asterisk source code? I added some code to chan_sip.c file, now i want logged them to file, as like asterisk do (ast_log() of ast_debug() functions), but i dont know where loggs is saved?

Although I also told you you were on the wrong forum, I did answer the question about logging.

Also note that you subject suggested that this was a developer question, and therefore off topic for the board as a whole. It was actually about logging, which is on topic. You need to more specific in your subject, e.g.:

Unable to get output from logging and debugging calls.