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.
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.
13 use ext::hygiene::{Mark, SyntaxContext};
14 use symbol::{Symbol, keywords};
15 use syntax_pos::{DUMMY_SP, Span};
16 use codemap::{self, ExpnInfo, NameAndSpan, MacroAttribute};
18 use tokenstream::TokenStream;
20 /// Craft a span that will be ignored by the stability lint's
21 /// call to codemap's `is_internal` check.
22 /// The expanded code uses the unstable `#[prelude_import]` attribute.
23 fn ignored_span(sp: Span) -> Span {
24 let mark = Mark::fresh();
25 mark.set_expn_info(ExpnInfo {
28 format: MacroAttribute(Symbol::intern("std_inject")),
30 allow_internal_unstable: true,
33 Span { ctxt: SyntaxContext::empty().apply_mark(mark), ..sp }
36 pub fn injected_crate_name(krate: &ast::Crate) -> Option<&'static str> {
37 if attr::contains_name(&krate.attrs, "no_core") {
39 } else if attr::contains_name(&krate.attrs, "no_std") {
46 pub fn maybe_inject_crates_ref(mut krate: ast::Crate, alt_std_name: Option<String>) -> ast::Crate {
47 let name = match injected_crate_name(&krate) {
52 let crate_name = Symbol::intern(&alt_std_name.unwrap_or_else(|| name.to_string()));
54 krate.module.items.insert(0, P(ast::Item {
55 attrs: vec![attr::mk_attr_outer(DUMMY_SP,
57 attr::mk_word_item(Symbol::intern("macro_use")))],
58 vis: ast::Visibility::Inherited,
59 node: ast::ItemKind::ExternCrate(Some(crate_name)),
60 ident: ast::Ident::from_str(name),
61 id: ast::DUMMY_NODE_ID,
65 let span = ignored_span(DUMMY_SP);
66 krate.module.items.insert(0, P(ast::Item {
67 attrs: vec![ast::Attribute {
68 style: ast::AttrStyle::Outer,
69 path: ast::Path::from_ident(span, ast::Ident::from_str("prelude_import")),
70 tokens: TokenStream::empty(),
71 id: attr::mk_attr_id(),
72 is_sugared_doc: false,
75 vis: ast::Visibility::Inherited,
76 node: ast::ItemKind::Use(P(codemap::dummy_spanned(ast::ViewPathGlob(ast::Path {
77 segments: ["{{root}}", name, "prelude", "v1"].into_iter().map(|name| {
78 ast::PathSegment::from_ident(ast::Ident::from_str(name), DUMMY_SP)
82 id: ast::DUMMY_NODE_ID,
83 ident: keywords::Invalid.ident(),