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use ast;
use attr;
use codemap::DUMMY_SP;
use codemap;
use fold::Folder;
use fold;
use parse::token::InternedString;
use parse::token::special_idents;
use parse::token;
use ptr::P;
use util::small_vector::SmallVector;
use std::mem;
pub fn maybe_inject_crates_ref(krate: ast::Crate, alt_std_name: Option<String>)
-> ast::Crate {
if use_std(&krate) {
inject_crates_ref(krate, alt_std_name)
} else {
krate
}
}
pub fn maybe_inject_prelude(krate: ast::Crate) -> ast::Crate {
if use_std(&krate) {
inject_prelude(krate)
} else {
krate
}
}
fn use_std(krate: &ast::Crate) -> bool {
!attr::contains_name(krate.attrs[], "no_std")
}
fn no_prelude(attrs: &[ast::Attribute]) -> bool {
attr::contains_name(attrs, "no_implicit_prelude")
}
struct StandardLibraryInjector<'a> {
alt_std_name: Option<String>,
}
impl<'a> fold::Folder for StandardLibraryInjector<'a> {
fn fold_crate(&mut self, mut krate: ast::Crate) -> ast::Crate {
let actual_crate_name = match self.alt_std_name {
Some(ref s) => token::intern_and_get_ident(s[]),
None => token::intern_and_get_ident("std"),
};
let mut vis = vec!(ast::ViewItem {
node: ast::ViewItemExternCrate(token::str_to_ident("std"),
Some((actual_crate_name, ast::CookedStr)),
ast::DUMMY_NODE_ID),
attrs: vec!(
attr::mk_attr_outer(attr::mk_attr_id(), attr::mk_list_item(
InternedString::new("phase"),
vec!(
attr::mk_word_item(InternedString::new("plugin")),
attr::mk_word_item(InternedString::new("link")
))))),
vis: ast::Inherited,
span: DUMMY_SP
});
mem::swap(&mut vis, &mut krate.module.view_items);
krate.module.view_items.extend(vis.into_iter());
let feat_phase_attr = attr::mk_attr_inner(attr::mk_attr_id(),
attr::mk_list_item(
InternedString::new("feature"),
vec![attr::mk_word_item(InternedString::new("phase"))],
));
attr::mark_used(&feat_phase_attr);
krate.attrs.push(feat_phase_attr);
krate
}
}
fn inject_crates_ref(krate: ast::Crate, alt_std_name: Option<String>) -> ast::Crate {
let mut fold = StandardLibraryInjector {
alt_std_name: alt_std_name,
};
fold.fold_crate(krate)
}
struct PreludeInjector<'a>;
impl<'a> fold::Folder for PreludeInjector<'a> {
fn fold_crate(&mut self, mut krate: ast::Crate) -> ast::Crate {
let no_std_attr = attr::mk_attr_inner(attr::mk_attr_id(),
attr::mk_word_item(InternedString::new("no_std")));
attr::mark_used(&no_std_attr);
krate.attrs.push(no_std_attr);
if !no_prelude(krate.attrs[]) {
let globs_attr = attr::mk_attr_inner(attr::mk_attr_id(),
attr::mk_list_item(
InternedString::new("feature"),
vec!(
attr::mk_word_item(InternedString::new("globs")),
)));
attr::mark_used(&globs_attr);
krate.attrs.push(globs_attr);
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[]) {
fold::noop_fold_item(item, self)
} else {
SmallVector::one(item)
}
}
fn fold_mod(&mut self, ast::Mod {inner, view_items, items}: ast::Mod) -> ast::Mod {
let prelude_path = ast::Path {
span: DUMMY_SP,
global: false,
segments: vec!(
ast::PathSegment {
identifier: token::str_to_ident("std"),
parameters: ast::PathParameters::none(),
},
ast::PathSegment {
identifier: token::str_to_ident("prelude"),
parameters: ast::PathParameters::none(),
}),
};
let (crates, uses): (Vec<_>, _) = view_items.iter().cloned().partition(|x| {
match x.node {
ast::ViewItemExternCrate(..) => true,
_ => false,
}
});
let mut view_items = crates;
let vp = P(codemap::dummy_spanned(ast::ViewPathGlob(prelude_path, ast::DUMMY_NODE_ID)));
view_items.push(ast::ViewItem {
node: ast::ViewItemUse(vp),
attrs: vec![ast::Attribute {
span: DUMMY_SP,
node: ast::Attribute_ {
id: attr::mk_attr_id(),
style: ast::AttrOuter,
value: P(ast::MetaItem {
span: DUMMY_SP,
node: ast::MetaWord(token::get_name(
special_idents::prelude_import.name)),
}),
is_sugared_doc: false,
},
}],
vis: ast::Inherited,
span: DUMMY_SP,
});
view_items.extend(uses.into_iter());
fold::noop_fold_mod(ast::Mod {
inner: inner,
view_items: view_items,
items: items
}, self)
}
}
fn inject_prelude(krate: ast::Crate) -> ast::Crate {
let mut fold = PreludeInjector;
fold.fold_crate(krate)
}