rust/src/libsyntax/ext/concat_idents.rs
Niko Matsakis a5ad4c3794 Delay assignment of node ids until after expansion. Ensures that each AST node
has a unique id. Fixes numerous bugs in macro expansion and deriving. Add two
representative tests.

Fixes #7971
Fixes #6304
Fixes #8367
Fixes #8754
Fixes #8852
Fixes #2543
Fixes #7654
2013-09-10 05:45:12 -04:00

56 lines
1.7 KiB
Rust

// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use ast;
use codemap::Span;
use ext::base::*;
use ext::base;
use opt_vec;
use parse::token;
use parse::token::{str_to_ident};
pub fn expand_syntax_ext(cx: @ExtCtxt, sp: Span, tts: &[ast::token_tree])
-> base::MacResult {
let mut res_str = ~"";
for (i, e) in tts.iter().enumerate() {
if i & 1 == 1 {
match *e {
ast::tt_tok(_, token::COMMA) => (),
_ => cx.span_fatal(sp, "concat_idents! expecting comma.")
}
} else {
match *e {
ast::tt_tok(_, token::IDENT(ident,_)) => res_str.push_str(cx.str_of(ident)),
_ => cx.span_fatal(sp, "concat_idents! requires ident args.")
}
}
}
let res = str_to_ident(res_str);
let e = @ast::Expr {
id: ast::DUMMY_NODE_ID,
node: ast::ExprPath(
ast::Path {
span: sp,
global: false,
segments: ~[
ast::PathSegment {
identifier: res,
lifetime: None,
types: opt_vec::Empty,
}
]
}
),
span: sp,
};
MRExpr(e)
}