Let\'s say I have a source file with many preprocessor directives. Is it possible to see how it looks after the preprocessor is done with it?
You typically need to do some postprocessing on the output of the preprocessor, otherwise all the macros just expand to one liners, which is hard to read and debug. For C code, something like the following would suffice:
gcc -E code.c | sed '/^\#/d' | indent -st -i2 > code-x.c
For C++ code, it's actually a lot harder. For GCC/g++, I found this Perl script useful.