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?
cl.exe, the command line interface to Microsoft Visual C++, has three different options for outputting the preprocessed file (hence the inconsistency in the previous responses about Visual C++):
/E: preprocess to stdout (similar to GCC's -E option)
/P: preprocess to file
/EP: preprocess to stdout without #line directives
If you want to preprocess to a file without #line directives, combine the
Most compilers have an option to just run the preprocessor. e.g., gcc provides -E:
-E Stop after the preprocessing stage; do not run the compiler proper. The output is in the form of preprocessed source code, which is sent to the standard output.
So you can just run:
gcc -E foo.c
If you can't find such an option, you can also just find the C preprocessor on your machine. It's usually called cpp and is probably already in your path. Invoke it like this:
If there are headers you need to include from other directories , you can pass -I/path/to/include/dir to either of these, just as you would with a regular compile.
For Windows, I'll leave it to other posters to provide answers as I'm no expert there.