| // 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 codemap::{DUMMY_SP, Span, ExpnInfo, NameAndSpan, MacroAttribute}; |
| use codemap; |
| use fold::Folder; |
| use fold; |
| use parse::token::{intern, InternedString, special_idents}; |
| use parse::{token, ParseSess}; |
| use ptr::P; |
| use util::small_vector::SmallVector; |
| |
| /// 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(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 maybe_inject_crates_ref(krate: ast::Crate, alt_std_name: Option<String>) |
| -> ast::Crate { |
| if no_core(&krate) { |
| krate |
| } else { |
| let name = if no_std(&krate) {"core"} else {"std"}; |
| let mut fold = CrateInjector { |
| item_name: token::str_to_ident(name), |
| crate_name: token::intern(&alt_std_name.unwrap_or(name.to_string())), |
| }; |
| fold.fold_crate(krate) |
| } |
| } |
| |
| pub fn maybe_inject_prelude(sess: &ParseSess, krate: ast::Crate) -> ast::Crate { |
| if no_core(&krate) { |
| krate |
| } else { |
| let name = if no_std(&krate) {"core"} else {"std"}; |
| let mut fold = PreludeInjector { |
| span: ignored_span(sess, DUMMY_SP), |
| crate_identifier: token::str_to_ident(name), |
| }; |
| fold.fold_crate(krate) |
| } |
| } |
| |
| pub fn no_core(krate: &ast::Crate) -> bool { |
| attr::contains_name(&krate.attrs, "no_core") |
| } |
| |
| pub fn no_std(krate: &ast::Crate) -> bool { |
| attr::contains_name(&krate.attrs, "no_std") || no_core(krate) |
| } |
| |
| fn no_prelude(attrs: &[ast::Attribute]) -> bool { |
| attr::contains_name(attrs, "no_implicit_prelude") |
| } |
| |
| struct CrateInjector { |
| item_name: ast::Ident, |
| crate_name: ast::Name, |
| } |
| |
| impl fold::Folder for CrateInjector { |
| fn fold_crate(&mut self, mut krate: ast::Crate) -> ast::Crate { |
| krate.module.items.insert(0, P(ast::Item { |
| id: ast::DUMMY_NODE_ID, |
| ident: self.item_name, |
| attrs: vec!( |
| attr::mk_attr_outer(attr::mk_attr_id(), attr::mk_word_item( |
| InternedString::new("macro_use")))), |
| node: ast::ItemExternCrate(Some(self.crate_name)), |
| vis: ast::Inherited, |
| span: DUMMY_SP |
| })); |
| |
| krate |
| } |
| } |
| |
| struct PreludeInjector { |
| span: Span, |
| crate_identifier: ast::Ident, |
| } |
| |
| impl fold::Folder for PreludeInjector { |
| fn fold_crate(&mut self, mut krate: ast::Crate) -> ast::Crate { |
| // only add `use std::prelude::*;` if there wasn't a |
| // `#![no_implicit_prelude]` at the crate level. |
| // fold_mod() will insert glob path. |
| if !no_prelude(&krate.attrs) { |
| krate.module = self.fold_mod(krate.module); |
| } |
| krate |
| } |
| |
| fn fold_item(&mut self, item: P<ast::Item>) -> SmallVector<P<ast::Item>> { |
| if !no_prelude(&item.attrs) { |
| // only recur if there wasn't `#![no_implicit_prelude]` |
| // on this item, i.e. this means that the prelude is not |
| // implicitly imported though the whole subtree |
| fold::noop_fold_item(item, self) |
| } else { |
| SmallVector::one(item) |
| } |
| } |
| |
| fn fold_mod(&mut self, mut mod_: ast::Mod) -> ast::Mod { |
| let prelude_path = ast::Path { |
| span: self.span, |
| global: false, |
| segments: vec![ |
| ast::PathSegment { |
| identifier: self.crate_identifier, |
| parameters: ast::PathParameters::none(), |
| }, |
| ast::PathSegment { |
| identifier: token::str_to_ident("prelude"), |
| parameters: ast::PathParameters::none(), |
| }, |
| ast::PathSegment { |
| identifier: token::str_to_ident("v1"), |
| parameters: ast::PathParameters::none(), |
| }, |
| ], |
| }; |
| |
| let vp = P(codemap::dummy_spanned(ast::ViewPathGlob(prelude_path))); |
| mod_.items.insert(0, P(ast::Item { |
| id: ast::DUMMY_NODE_ID, |
| ident: special_idents::invalid, |
| node: ast::ItemUse(vp), |
| attrs: vec![ast::Attribute { |
| span: self.span, |
| node: ast::Attribute_ { |
| id: attr::mk_attr_id(), |
| style: ast::AttrStyle::Outer, |
| value: P(ast::MetaItem { |
| span: self.span, |
| node: ast::MetaWord(special_idents::prelude_import.name.as_str()), |
| }), |
| is_sugared_doc: false, |
| }, |
| }], |
| vis: ast::Inherited, |
| span: self.span, |
| })); |
| |
| fold::noop_fold_mod(mod_, self) |
| } |
| } |