diff options
Diffstat (limited to 'src/test/ui/proc-macro/auxiliary/subspan.rs')
-rw-r--r-- | src/test/ui/proc-macro/auxiliary/subspan.rs | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/src/test/ui/proc-macro/auxiliary/subspan.rs b/src/test/ui/proc-macro/auxiliary/subspan.rs new file mode 100644 index 000000000..f92adc040 --- /dev/null +++ b/src/test/ui/proc-macro/auxiliary/subspan.rs @@ -0,0 +1,38 @@ +// force-host +// no-prefer-dynamic + +#![crate_type = "proc-macro"] +#![feature(proc_macro_diagnostic, proc_macro_span)] + +extern crate proc_macro; + +use proc_macro::{TokenStream, TokenTree, Span, Diagnostic}; + +fn parse(input: TokenStream) -> Result<(), Diagnostic> { + if let Some(TokenTree::Literal(lit)) = input.into_iter().next() { + let mut spans = vec![]; + let string = lit.to_string(); + for hi in string.matches("hi") { + let index = hi.as_ptr() as usize - string.as_ptr() as usize; + let subspan = lit.subspan(index..(index + hi.len())).unwrap(); + spans.push(subspan); + } + + if !spans.is_empty() { + Err(Span::call_site().error("found 'hi's").span_note(spans, "here")) + } else { + Ok(()) + } + } else { + Err(Span::call_site().error("invalid input: expected string literal")) + } +} + +#[proc_macro] +pub fn subspan(input: TokenStream) -> TokenStream { + if let Err(diag) = parse(input) { + diag.emit(); + } + + TokenStream::new() +} |