+// Copyright 2015 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 metadata::cstore::LOCAL_CRATE;
+use middle::def_id::{DefId, DefIndex};
+use rustc_data_structures::fnv::FnvHashMap;
+use rustc_front::hir;
+use syntax::ast;
+use syntax::parse::token::InternedString;
+use util::nodemap::NodeMap;
+
+#[derive(Clone)]
+pub struct Definitions {
+ data: Vec<DefData>,
+ key_map: FnvHashMap<DefKey, DefIndex>,
+ node_map: NodeMap<DefIndex>,
+}
+
+/// A unique identifier that we can use to lookup a definition
+/// precisely. It combines the index of the definition's parent (if
+/// any) with a `DisambiguatedDefPathData`.
+#[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
+pub struct DefKey {
+ /// Parent path.
+ pub parent: Option<DefIndex>,
+
+ /// Identifier of this node.
+ pub disambiguated_data: DisambiguatedDefPathData,
+}
+
+/// Pair of `DefPathData` and an integer disambiguator. The integer is
+/// normally 0, but in the event that there are multiple defs with the
+/// same `parent` and `data`, we use this field to disambiguate
+/// between them. This introduces some artificial ordering dependency
+/// but means that if you have (e.g.) two impls for the same type in
+/// the same module, they do get distinct def-ids.
+#[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
+pub struct DisambiguatedDefPathData {
+ pub data: DefPathData,
+ pub disambiguator: u32
+}
+
+/// For each definition, we track the following data. A definition
+/// here is defined somewhat circularly as "something with a def-id",
+/// but it generally corresponds to things like structs, enums, etc.
+/// There are also some rather random cases (like const initializer
+/// expressions) that are mostly just leftovers.
+#[derive(Clone, Debug)]
+pub struct DefData {
+ pub key: DefKey,
+
+ /// Local ID within the HIR.
+ pub node_id: ast::NodeId,
+}
+
+pub type DefPath = Vec<DisambiguatedDefPathData>;
+
+#[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
+pub enum DefPathData {
+ // Root: these should only be used for the root nodes, because
+ // they are treated specially by the `def_path` function.
+ CrateRoot,
+ InlinedRoot(DefPath),
+
+ // Catch-all for random DefId things like DUMMY_NODE_ID
+ Misc,
+
+ // Different kinds of items and item-like things:
+ Impl,
+ Type(ast::Name),
+ Mod(ast::Name),
+ Value(ast::Name),
+ MacroDef(ast::Name),
+ ClosureExpr,
+
+ // Subportions of items
+ TypeParam(ast::Name),
+ LifetimeDef(ast::Name),
+ EnumVariant(ast::Name),
+ PositionalField,
+ Field(hir::StructFieldKind),
+ StructCtor, // implicit ctor for a tuple-like struct
+ Initializer, // initializer for a const
+ Binding(ast::Name), // pattern binding
+
+ // An external crate that does not have an `extern crate` in this
+ // crate.
+ DetachedCrate(ast::Name),
+}
+
+impl Definitions {
+ pub fn new() -> Definitions {
+ Definitions {
+ data: vec![],
+ key_map: FnvHashMap(),
+ node_map: NodeMap(),
+ }
+ }
+
+ pub fn len(&self) -> usize {
+ self.data.len()
+ }
+
+ pub fn def_key(&self, index: DefIndex) -> DefKey {
+ self.data[index.as_usize()].key.clone()
+ }
+
+ /// Returns the path from the crate root to `index`. The root
+ /// nodes are not included in the path (i.e., this will be an
+ /// empty vector for the crate root). For an inlined item, this
+ /// will be the path of the item in the external crate (but the
+ /// path will begin with the path to the external crate).
+ pub fn def_path(&self, index: DefIndex) -> DefPath {
+ make_def_path(index, |p| self.def_key(p))
+ }
+
+ pub fn opt_def_index(&self, node: ast::NodeId) -> Option<DefIndex> {
+ self.node_map.get(&node).cloned()
+ }
+
+ pub fn opt_local_def_id(&self, node: ast::NodeId) -> Option<DefId> {
+ self.opt_def_index(node).map(DefId::local)
+ }
+
+ pub fn as_local_node_id(&self, def_id: DefId) -> Option<ast::NodeId> {
+ if def_id.krate == LOCAL_CRATE {
+ assert!(def_id.index.as_usize() < self.data.len());
+ Some(self.data[def_id.index.as_usize()].node_id)
+ } else {
+ None
+ }
+ }
+
+ pub fn create_def_with_parent(&mut self,
+ parent: Option<DefIndex>,
+ node_id: ast::NodeId,
+ data: DefPathData)
+ -> DefIndex {
+ assert!(!self.node_map.contains_key(&node_id),
+ "adding a def'n for node-id {:?} and data {:?} but a previous def'n exists: {:?}",
+ node_id,
+ data,
+ self.data[self.node_map[&node_id].as_usize()]);
+
+ // Find a unique DefKey. This basically means incrementing the disambiguator
+ // until we get no match.
+ let mut key = DefKey {
+ parent: parent,
+ disambiguated_data: DisambiguatedDefPathData {
+ data: data,
+ disambiguator: 0
+ }
+ };
+
+ while self.key_map.contains_key(&key) {
+ key.disambiguated_data.disambiguator += 1;
+ }
+
+ // Create the definition.
+ let index = DefIndex::new(self.data.len());
+ self.data.push(DefData { key: key.clone(), node_id: node_id });
+ self.node_map.insert(node_id, index);
+ self.key_map.insert(key, index);
+
+ index
+ }
+}
+
+impl DefPathData {
+ pub fn as_interned_str(&self) -> InternedString {
+ use self::DefPathData::*;
+ match *self {
+ Type(name) |
+ Mod(name) |
+ Value(name) |
+ MacroDef(name) |
+ TypeParam(name) |
+ LifetimeDef(name) |
+ EnumVariant(name) |
+ DetachedCrate(name) |
+ Binding(name) => {
+ name.as_str()
+ }
+
+ Field(hir::StructFieldKind::NamedField(name, _)) => {
+ name.as_str()
+ }
+
+ PositionalField |
+ Field(hir::StructFieldKind::UnnamedField(_)) => {
+ InternedString::new("<field>")
+ }
+
+ // note that this does not show up in user printouts
+ CrateRoot => {
+ InternedString::new("<root>")
+ }
+
+ // note that this does not show up in user printouts
+ InlinedRoot(_) => {
+ InternedString::new("<inlined-root>")
+ }
+
+ Misc => {
+ InternedString::new("?")
+ }
+
+ Impl => {
+ InternedString::new("<impl>")
+ }
+
+ ClosureExpr => {
+ InternedString::new("<closure>")
+ }
+
+ StructCtor => {
+ InternedString::new("<constructor>")
+ }
+
+ Initializer => {
+ InternedString::new("<initializer>")
+ }
+ }
+ }
+
+ pub fn to_string(&self) -> String {
+ self.as_interned_str().to_string()
+ }
+}
+
+pub fn make_def_path<FN>(start_index: DefIndex, mut get_key: FN) -> DefPath
+ where FN: FnMut(DefIndex) -> DefKey
+{
+ let mut result = vec![];
+ let mut index = Some(start_index);
+ while let Some(p) = index {
+ let key = get_key(p);
+ match key.disambiguated_data.data {
+ DefPathData::CrateRoot => {
+ assert!(key.parent.is_none());
+ break;
+ }
+ DefPathData::InlinedRoot(ref p) => {
+ assert!(key.parent.is_none());
+ result.extend(p.iter().cloned().rev());
+ break;
+ }
+ _ => {
+ result.push(key.disambiguated_data);
+ index = key.parent;
+ }
+ }
+ }
+ result.reverse();
+ result
+}