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.
12 use driver::session::Session;
16 use syntax::codemap::DUMMY_SP;
18 use syntax::fold::Folder;
20 use syntax::owned_slice::OwnedSlice;
21 use syntax::parse::token::InternedString;
22 use syntax::parse::token::special_idents;
23 use syntax::parse::token;
24 use syntax::util::small_vector::SmallVector;
27 use std::gc::{Gc, GC};
29 pub fn maybe_inject_crates_ref(sess: &Session, krate: ast::Crate)
32 inject_crates_ref(sess, krate)
38 pub fn maybe_inject_prelude(sess: &Session, krate: ast::Crate) -> ast::Crate {
40 inject_prelude(sess, krate)
46 fn use_std(krate: &ast::Crate) -> bool {
47 !attr::contains_name(krate.attrs.as_slice(), "no_std")
50 fn use_start(krate: &ast::Crate) -> bool {
51 !attr::contains_name(krate.attrs.as_slice(), "no_start")
54 fn no_prelude(attrs: &[ast::Attribute]) -> bool {
55 attr::contains_name(attrs, "no_implicit_prelude")
58 struct StandardLibraryInjector<'a> {
62 impl<'a> fold::Folder for StandardLibraryInjector<'a> {
63 fn fold_crate(&mut self, mut krate: ast::Crate) -> ast::Crate {
65 // The name to use in `extern crate std = "name";`
66 let actual_crate_name = match self.sess.opts.alt_std_name {
67 Some(ref s) => token::intern_and_get_ident(s.as_slice()),
68 None => token::intern_and_get_ident("std"),
71 let mut vis = vec!(ast::ViewItem {
72 node: ast::ViewItemExternCrate(token::str_to_ident("std"),
73 Some((actual_crate_name, ast::CookedStr)),
76 attr::mk_attr_outer(attr::mk_attr_id(), attr::mk_list_item(
77 InternedString::new("phase"),
79 attr::mk_word_item(InternedString::new("plugin")),
80 attr::mk_word_item(InternedString::new("link")
86 let any_exe = self.sess.crate_types.borrow().iter().any(|ty| {
87 *ty == config::CrateTypeExecutable
89 if use_start(&krate) && any_exe {
90 let visible_rt_name = "rt";
91 let actual_rt_name = "native";
92 // Gensym the ident so it can't be named
93 let visible_rt_name = token::gensym_ident(visible_rt_name);
94 let actual_rt_name = token::intern_and_get_ident(actual_rt_name);
96 vis.push(ast::ViewItem {
97 node: ast::ViewItemExternCrate(visible_rt_name,
98 Some((actual_rt_name, ast::CookedStr)),
106 // `extern crate` must be precede `use` items
107 mem::swap(&mut vis, &mut krate.module.view_items);
108 krate.module.view_items.push_all_move(vis);
110 // don't add #![no_std] here, that will block the prelude injection later.
111 // Add it during the prelude injection instead.
113 // Add #![feature(phase)] here, because we use #[phase] on extern crate std.
114 let feat_phase_attr = attr::mk_attr_inner(attr::mk_attr_id(),
116 InternedString::new("feature"),
117 vec![attr::mk_word_item(InternedString::new("phase"))],
119 // std_inject runs after feature checking so manually mark this attr
120 attr::mark_used(&feat_phase_attr);
121 krate.attrs.push(feat_phase_attr);
127 fn inject_crates_ref(sess: &Session, krate: ast::Crate) -> ast::Crate {
128 let mut fold = StandardLibraryInjector {
131 fold.fold_crate(krate)
134 struct PreludeInjector<'a>;
137 impl<'a> fold::Folder for PreludeInjector<'a> {
138 fn fold_crate(&mut self, mut krate: ast::Crate) -> ast::Crate {
139 // Add #![no_std] here, so we don't re-inject when compiling pretty-printed source.
140 // This must happen here and not in StandardLibraryInjector because this
141 // fold happens second.
143 let no_std_attr = attr::mk_attr_inner(attr::mk_attr_id(),
144 attr::mk_word_item(InternedString::new("no_std")));
145 // std_inject runs after feature checking so manually mark this attr
146 attr::mark_used(&no_std_attr);
147 krate.attrs.push(no_std_attr);
149 if !no_prelude(krate.attrs.as_slice()) {
150 // only add `use std::prelude::*;` if there wasn't a
151 // `#![no_implicit_prelude]` at the crate level.
153 // fold_mod() will insert glob path.
154 let globs_attr = attr::mk_attr_inner(attr::mk_attr_id(),
156 InternedString::new("feature"),
158 attr::mk_word_item(InternedString::new("globs")),
160 // std_inject runs after feature checking so manually mark this attr
161 attr::mark_used(&globs_attr);
162 krate.attrs.push(globs_attr);
164 krate.module = self.fold_mod(&krate.module);
169 fn fold_item(&mut self, item: Gc<ast::Item>) -> SmallVector<Gc<ast::Item>> {
170 if !no_prelude(item.attrs.as_slice()) {
171 // only recur if there wasn't `#![no_implicit_prelude]`
172 // on this item, i.e. this means that the prelude is not
173 // implicitly imported though the whole subtree
174 fold::noop_fold_item(&*item, self)
176 SmallVector::one(item)
180 fn fold_mod(&mut self, module: &ast::Mod) -> ast::Mod {
181 let prelude_path = ast::Path {
186 identifier: token::str_to_ident("std"),
187 lifetimes: Vec::new(),
188 types: OwnedSlice::empty(),
191 identifier: token::str_to_ident("prelude"),
192 lifetimes: Vec::new(),
193 types: OwnedSlice::empty(),
197 let vp = box(GC) codemap::dummy_spanned(ast::ViewPathGlob(prelude_path,
198 ast::DUMMY_NODE_ID));
199 let vi2 = ast::ViewItem {
200 node: ast::ViewItemUse(vp),
201 attrs: vec!(ast::Attribute {
203 node: ast::Attribute_ {
204 id: attr::mk_attr_id(),
205 style: ast::AttrOuter,
206 value: box(GC) ast::MetaItem {
208 node: ast::MetaWord(token::get_name(
209 special_idents::prelude_import.name)),
211 is_sugared_doc: false,
218 let (crates, uses) = module.view_items.partitioned(|x| {
220 ast::ViewItemExternCrate(..) => true,
225 // add vi2 after any `extern crate` but before any `use`
226 let mut view_items = crates;
227 view_items.push(vi2);
228 view_items.push_all_move(uses);
230 let new_module = ast::Mod {
231 view_items: view_items,
234 fold::noop_fold_mod(&new_module, self)
238 fn inject_prelude(_: &Session, krate: ast::Crate) -> ast::Crate {
239 let mut fold = PreludeInjector;
240 fold.fold_crate(krate)