Function process_source_file 

pub fn process_source_file<T>(
    file_provider: &T,
    header_file_cache: &mut HeaderFileCache,
    reserved_identifiers: &[&str],
    predefinitions: &HashMap<String, String>,
    resolve_relative_path_within_current_file: bool,
    enable_multiple_token_argument: bool,
    source_file_number: usize,
    source_file_path_name: &Path,
    source_file_canonical_full_path: &Path,
) -> Result<PreprocessResult, PreprocessFileError>
where
    T: FileProvider,

Preprocesses a C source file.

see also:

• https://en.cppreference.com/w/c/language.html
• https://en.cppreference.com/w/c/preprocessor.html
• https://en.cppreference.com/w/c/language/translation_phases.html