Have error output include last couple lines of code

Question

Is it possible, and if so, how would you make error output include the last couple lines of code? I know about GNU g++'s support for __LINE__ and __FUNC__ but those only give the line number as an int and the function name as a string - I'd like to dump the function that failed's code or at least the last several commands executed by the program.

I was thinking maybe write a m4 script that would parse through the code base and inject string structures of the functions they're put in (excluding themselves, of course).

Any other/better ideas?

Answer 1

Do not change your code at all. Use __LINE__ and __FUNC__ and post process the error output. That is, run your program as my-prog > $(tty) 2>&1 | post-process where post-process has access to your code base and can generate the desired text. You might want to modify the code slightly by adding tags to make it easier for post-process to find the function name and line number.