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use util::nodemap::{NodeMap, DefIdMap};
use syntax::codemap::Span;
use syntax::{attr, visit};
use syntax::ast;
use syntax::ast::{Attribute, Block, Crate, DefId, FnDecl, NodeId, Variant};
use syntax::ast::{Item, RequiredMethod, ProvidedMethod, TraitItem};
use syntax::ast::{TypeMethod, Method, Generics, StructField, TypeTraitItem};
use syntax::ast_util::is_local;
use syntax::attr::Stability;
use syntax::visit::{FnKind, FkMethod, Visitor};
use middle::ty;
use metadata::csearch;
use std::mem::replace;
pub struct Index {
local: NodeMap<Stability>,
extern_cache: DefIdMap<Option<Stability>>
}
struct Annotator {
index: Index,
parent: Option<Stability>
}
impl Annotator {
fn annotate<F>(&mut self, id: NodeId, use_parent: bool,
attrs: &Vec<Attribute>, f: F) where
F: FnOnce(&mut Annotator),
{
match attr::find_stability(attrs.as_slice()) {
Some(stab) => {
self.index.local.insert(id, stab.clone());
if stab.level != attr::Stable {
let parent = replace(&mut self.parent, Some(stab));
f(self);
self.parent = parent;
} else {
f(self);
}
}
None => {
if use_parent {
self.parent.clone().map(|stab| self.index.local.insert(id, stab));
}
f(self);
}
}
}
}
impl<'v> Visitor<'v> for Annotator {
fn visit_item(&mut self, i: &Item) {
let use_parent = match i.node {
ast::ItemImpl(_, _, Some(_), _, _) => false,
_ => true,
};
self.annotate(i.id, use_parent, &i.attrs, |v| visit::walk_item(v, i));
if let ast::ItemStruct(ref sd, _) = i.node {
sd.ctor_id.map(|id| {
self.annotate(id, true, &i.attrs, |_| {})
});
}
}
fn visit_fn(&mut self, fk: FnKind<'v>, _: &'v FnDecl,
_: &'v Block, _: Span, _: NodeId) {
if let FkMethod(_, _, meth) = fk {
self.annotate(meth.id, true, &meth.attrs, |_| {});
}
}
fn visit_trait_item(&mut self, t: &TraitItem) {
let (id, attrs) = match *t {
RequiredMethod(TypeMethod {id, ref attrs, ..}) => (id, attrs),
ProvidedMethod(ref method) => {
match **method {
Method {ref attrs, id, ..} => (id, attrs),
}
}
TypeTraitItem(ref typedef) => (typedef.ty_param.id, &typedef.attrs),
};
self.annotate(id, true, attrs, |v| visit::walk_trait_item(v, t));
}
fn visit_variant(&mut self, var: &Variant, g: &'v Generics) {
self.annotate(var.node.id, true, &var.node.attrs,
|v| visit::walk_variant(v, var, g))
}
fn visit_struct_field(&mut self, s: &StructField) {
self.annotate(s.node.id, true, &s.node.attrs,
|v| visit::walk_struct_field(v, s));
}
fn visit_foreign_item(&mut self, i: &ast::ForeignItem) {
self.annotate(i.id, true, &i.attrs, |_| {});
}
}
impl Index {
pub fn build(krate: &Crate) -> Index {
let mut annotator = Annotator {
index: Index {
local: NodeMap::new(),
extern_cache: DefIdMap::new()
},
parent: None
};
annotator.annotate(ast::CRATE_NODE_ID, true, &krate.attrs,
|v| visit::walk_crate(v, krate));
annotator.index
}
}
pub fn lookup(tcx: &ty::ctxt, id: DefId) -> Option<Stability> {
match ty::trait_item_of_item(tcx, id) {
Some(ty::MethodTraitItemId(trait_method_id))
if trait_method_id != id => {
return lookup(tcx, trait_method_id)
}
_ => {}
}
let item_stab = if is_local(id) {
tcx.stability.borrow().local.get(&id.node).cloned()
} else {
let stab = csearch::get_stability(&tcx.sess.cstore, id);
let mut index = tcx.stability.borrow_mut();
(*index).extern_cache.insert(id, stab.clone());
stab
};
item_stab.or_else(|| {
if let Some(trait_id) = ty::trait_id_of_impl(tcx, id) {
lookup(tcx, trait_id)
} else {
None
}
})
}