mirror of https://github.com/rust-lang/rust
38 lines
873 B
Rust
38 lines
873 B
Rust
//@ force-host
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//@ no-prefer-dynamic
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#![crate_type = "proc-macro"]
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#![feature(proc_macro_diagnostic, proc_macro_span, proc_macro_def_site)]
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extern crate proc_macro;
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use proc_macro::{TokenStream, TokenTree, Span, Diagnostic};
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fn parse(input: TokenStream) -> Result<(), Diagnostic> {
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let mut hi_spans = vec![];
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for tree in input {
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if let TokenTree::Ident(ref ident) = tree {
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if ident.to_string() == "hi" {
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hi_spans.push(ident.span());
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}
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}
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}
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if !hi_spans.is_empty() {
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return Err(Span::def_site()
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.error("hello to you, too!")
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.span_note(hi_spans, "found these 'hi's"));
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}
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Ok(())
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}
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#[proc_macro]
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pub fn hello(input: TokenStream) -> TokenStream {
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if let Err(diag) = parse(input) {
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diag.emit();
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}
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TokenStream::new()
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}
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