Function rustc_builtin_macros::source_util::expand_file

source ยท 
pub(crate) fn expand_file(
    cx: &mut ExtCtxt<'_>,
    sp: Span,
    tts: TokenStream,
) -> MacroExpanderResult<'static>
Expand description

file!(): expands to the current filename */ The source_file (loc.file) contains a bunch more information we could spit out if we wanted.