Hi,
 I think it would be useful to display the preprocessed line with errors (in C/C++ in my case) for those occasions when the problem is related to a macro going wrong.    I suggest this would be an option since most of the time you wouldn't want it.

  Crawling through the output of gcc -E  and trying to find the line that actually corresponds the error is quite hard work, and if the compiler already has the line that it should help us by showing it (possibly with the line before as well?)

Dave