rust/src/libsyntax/std_inject.rs

95 lines
3.1 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 attr;
use symbol::{Symbol, keywords};
use syntax_pos::{DUMMY_SP, Span};
use codemap::{self, ExpnInfo, NameAndSpan, MacroAttribute};
use parse::ParseSess;
use ptr::P;
/// Craft a span that will be ignored by the stability lint's
/// call to codemap's is_internal check.
/// The expanded code uses the unstable `#[prelude_import]` attribute.
fn ignored_span(sess: &ParseSess, sp: Span) -> Span {
let info = ExpnInfo {
call_site: DUMMY_SP,
callee: NameAndSpan {
format: MacroAttribute(Symbol::intern("std_inject")),
span: None,
allow_internal_unstable: true,
}
};
let expn_id = sess.codemap().record_expansion(info);
let mut sp = sp;
sp.expn_id = expn_id;
return sp;
}
pub fn injected_crate_name(krate: &ast::Crate) -> Option<&'static str> {
if attr::contains_name(&krate.attrs, "no_core") {
None
} else if attr::contains_name(&krate.attrs, "no_std") {
Some("core")
} else {
Some("std")
}
}
pub fn maybe_inject_crates_ref(sess: &ParseSess,
mut krate: ast::Crate,
alt_std_name: Option<String>)
-> ast::Crate {
let name = match injected_crate_name(&krate) {
Some(name) => name,
None => return krate,
};
let crate_name = Symbol::intern(&alt_std_name.unwrap_or(name.to_string()));
krate.module.items.insert(0, P(ast::Item {
attrs: vec![attr::mk_attr_outer(attr::mk_attr_id(),
attr::mk_word_item(Symbol::intern("macro_use")))],
vis: ast::Visibility::Inherited,
node: ast::ItemKind::ExternCrate(Some(crate_name)),
ident: ast::Ident::from_str(name),
id: ast::DUMMY_NODE_ID,
span: DUMMY_SP,
}));
let span = ignored_span(sess, DUMMY_SP);
krate.module.items.insert(0, P(ast::Item {
attrs: vec![ast::Attribute {
style: ast::AttrStyle::Outer,
value: ast::MetaItem {
name: Symbol::intern("prelude_import"),
node: ast::MetaItemKind::Word,
span: span,
},
id: attr::mk_attr_id(),
is_sugared_doc: false,
span: span,
}],
vis: ast::Visibility::Inherited,
node: ast::ItemKind::Use(P(codemap::dummy_spanned(ast::ViewPathGlob(ast::Path {
segments: ["{{root}}", name, "prelude", "v1"].into_iter().map(|name| {
ast::Ident::from_str(name).into()
}).collect(),
span: span,
})))),
id: ast::DUMMY_NODE_ID,
ident: keywords::Invalid.ident(),
span: span,
}));
krate
}