30 lines
825 B
Rust
30 lines
825 B
Rust
use rustc_ast::tokenstream::{TokenStream, TokenTree};
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use rustc_expand::base::{self, ExtCtxt};
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use rustc_span::symbol::kw;
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use rustc_span::Span;
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pub fn expand_trace_macros(
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cx: &mut ExtCtxt<'_>,
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sp: Span,
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tt: TokenStream,
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) -> Box<dyn base::MacResult + 'static> {
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let mut cursor = tt.into_trees();
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let mut err = false;
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let value = match &cursor.next() {
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Some(TokenTree::Token(token)) if token.is_keyword(kw::True) => true,
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Some(TokenTree::Token(token)) if token.is_keyword(kw::False) => false,
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_ => {
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err = true;
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false
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}
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};
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err |= cursor.next().is_some();
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if err {
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cx.span_err(sp, "trace_macros! accepts only `true` or `false`")
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} else {
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cx.set_trace_macros(value);
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}
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base::DummyResult::any_valid(sp)
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}
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