1 // Copyright 2012 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
4 //
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
10
11 use ast;
12 use codemap::Span;
13 use ext::base::ExtCtxt;
14 use ext::base;
15 use parse::token::{keywords, is_keyword};
16
17
18 pub fn expand_trace_macros(cx: &mut ExtCtxt,
19 sp: Span,
20 tt: &[ast::TokenTree])
21 -> Box<base::MacResult> {
22 match tt {
23 [ast::TTTok(_, ref tok)] if is_keyword(keywords::True, tok) => {
24 cx.set_trace_macros(true);
25 }
26 [ast::TTTok(_, ref tok)] if is_keyword(keywords::False, tok) => {
27 cx.set_trace_macros(false);
28 }
29 _ => cx.span_err(sp, "trace_macros! accepts only `true` or `false`"),
30 }
31
32 base::DummyResult::any(sp)
33 }