GNU C language preprocessor. cpp is normally invoked as the first pass of any C compilation by the gcc command. The output of cpp is a form acceptable as input to the next pass of the C compiler. The ifile and ofile options are, respectively, the input and output for the preprocessor; they default to standard input and standard output.
Do not allow $ in identifiers.
Use 1990 ISO C standard. This is equivalent to -std=c89.
Similar to -dM, but exclude predefined macros and include results of preprocessing.
Suppress normal output. Print series of #defines that create the macros used in the source file.
Similar to -dD, but don’t print macro expansions.
Print #include directives in addition to other output.
Treat file as already preprocessed. Skip most processing directives, remove all comments, and tokenize file.
Set distance between tabstops so columns will be reported correctly in warnings and errors. Default is 8.
Omit column numbers in warnings and errors.
Define _ _GNUC_ _, _ _GNUC_MINOR_ _, and _ _GNUC_PATCHLEVEL_ _ macros.
Print usage message and exit.
Search dir for header files when a header file is not found in any of the included directories.
Process macros in file before processing main files.
Process file before main file.
When adding directories with -iwithprefix, prepend ...