Tracing C program
 

The idea is to automatically modify C source (or maybe binary) so it would print the source code line as soon as it is about to execute with maximum possible info about values of particular variables, arguments to functions, addresses and etc. Yet it should run as in normal mode (w/o debugging) and should not break for example on receiving signal as gdb does. Can I somehow do that?

Yet it should run as in normal mode (w/o debugging)

w/o the debugging symbols .. there is no way you can print line no. etc. thats for sure.

Other than that, I really don't have much of an idea.

__file__
 

GCC has some built-in macros like __FILE__ and similar to print debugging info using printf statements. I have used this sometimes to print information, though I do nothave examples available right now. Have a look at the GCC documentation. I don't think this is portable among compilers.

Linux

would you also like it to automatically fix any bugs that it comes across?