src/librustc/hir/map/collector.rs

   1 // Copyright 2015-2016 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.
   4 //
   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.
  10
  11 use super::*;
  12 use super::MapEntry::*;
  13
  14 use hir::*;
  15 use hir::intravisit::Visitor;
  16 use hir::def_id::DefId;
  17 use middle::cstore::InlinedItem;
  18 use std::iter::repeat;
  19 use syntax::ast::{NodeId, CRATE_NODE_ID};
  20 use syntax::codemap::Span;
  21
  22 /// A Visitor that walks over the HIR and collects Nodes into a HIR map
  23 pub struct NodeCollector<'ast> {
  24     /// The crate
  25     pub krate: &'ast Crate,
  26     /// The node map
  27     pub map: Vec<MapEntry<'ast>>,
  28     /// The parent of this node
  29     pub parent_node: NodeId,
  30 }
  31
  32 impl<'ast> NodeCollector<'ast> {
  33     pub fn root(krate: &'ast Crate) -> NodeCollector<'ast> {
  34         let mut collector = NodeCollector {
  35             krate: krate,
  36             map: vec![],
  37             parent_node: CRATE_NODE_ID,
  38         };
  39         collector.insert_entry(CRATE_NODE_ID, RootCrate);
  40
  41         collector
  42     }
  43
  44     pub fn extend(krate: &'ast Crate,
  45                   parent: &'ast InlinedItem,
  46                   parent_node: NodeId,
  47                   parent_def_path: DefPath,
  48                   parent_def_id: DefId,
  49                   map: Vec<MapEntry<'ast>>)
  50                   -> NodeCollector<'ast> {
  51         let mut collector = NodeCollector {
  52             krate: krate,
  53             map: map,
  54             parent_node: parent_node,
  55         };
  56
  57         assert_eq!(parent_def_path.krate, parent_def_id.krate);
  58         collector.insert_entry(parent_node, RootInlinedParent(parent));
  59
  60         collector
  61     }
  62
  63     fn insert_entry(&mut self, id: NodeId, entry: MapEntry<'ast>) {
  64         debug!("ast_map: {:?} => {:?}", id, entry);
  65         let len = self.map.len();
  66         if id as usize >= len {
  67             self.map.extend(repeat(NotPresent).take(id as usize - len + 1));
  68         }
  69         self.map[id as usize] = entry;
  70     }
  71
  72     fn insert(&mut self, id: NodeId, node: Node<'ast>) {
  73         let entry = MapEntry::from_node(self.parent_node, node);
  74         self.insert_entry(id, entry);
  75     }
  76
  77     fn with_parent<F: FnOnce(&mut Self)>(&mut self, parent_id: NodeId, f: F) {
  78         let parent_node = self.parent_node;
  79         self.parent_node = parent_id;
  80         f(self);
  81         self.parent_node = parent_node;
  82     }
  83 }
  84
  85 impl<'ast> Visitor<'ast> for NodeCollector<'ast> {
  86     /// Because we want to track parent items and so forth, enable
  87     /// deep walking so that we walk nested items in the context of
  88     /// their outer items.
  89     fn visit_nested_item(&mut self, item: ItemId) {
  90         debug!("visit_nested_item: {:?}", item);
  91         self.visit_item(self.krate.item(item.id))
  92     }
  93
  94     fn visit_item(&mut self, i: &'ast Item) {
  95         debug!("visit_item: {:?}", i);
  96
  97         self.insert(i.id, NodeItem(i));
  98
  99         self.with_parent(i.id, |this| {
 100             match i.node {
 101                 ItemEnum(ref enum_definition, _) => {
 102                     for v in &enum_definition.variants {
 103                         this.insert(v.node.data.id(), NodeVariant(v));
 104                     }
 105                 }
 106                 ItemStruct(ref struct_def, _) => {
 107                     // If this is a tuple-like struct, register the constructor.
 108                     if !struct_def.is_struct() {
 109                         this.insert(struct_def.id(), NodeStructCtor(struct_def));
 110                     }
 111                 }
 112                 ItemTrait(_, _, ref bounds, _) => {
 113                     for b in bounds.iter() {
 114                         if let TraitTyParamBound(ref t, TraitBoundModifier::None) = *b {
 115                             this.insert(t.trait_ref.ref_id, NodeItem(i));
 116                         }
 117                     }
 118                 }
 119                 ItemUse(ref view_path) => {
 120                     match view_path.node {
 121                         ViewPathList(_, ref paths) => {
 122                             for path in paths {
 123                                 this.insert(path.node.id(), NodeItem(i));
 124                             }
 125                         }
 126                         _ => ()
 127                     }
 128                 }
 129                 _ => {}
 130             }
 131             intravisit::walk_item(this, i);
 132         });
 133     }
 134
 135     fn visit_foreign_item(&mut self, foreign_item: &'ast ForeignItem) {
 136         self.insert(foreign_item.id, NodeForeignItem(foreign_item));
 137
 138         self.with_parent(foreign_item.id, |this| {
 139             intravisit::walk_foreign_item(this, foreign_item);
 140         });
 141     }
 142
 143     fn visit_generics(&mut self, generics: &'ast Generics) {
 144         for ty_param in generics.ty_params.iter() {
 145             self.insert(ty_param.id, NodeTyParam(ty_param));
 146         }
 147
 148         intravisit::walk_generics(self, generics);
 149     }
 150
 151     fn visit_trait_item(&mut self, ti: &'ast TraitItem) {
 152         self.insert(ti.id, NodeTraitItem(ti));
 153
 154         self.with_parent(ti.id, |this| {
 155             intravisit::walk_trait_item(this, ti);
 156         });
 157     }
 158
 159     fn visit_impl_item(&mut self, ii: &'ast ImplItem) {
 160         self.insert(ii.id, NodeImplItem(ii));
 161
 162         self.with_parent(ii.id, |this| {
 163             intravisit::walk_impl_item(this, ii);
 164         });
 165     }
 166
 167     fn visit_pat(&mut self, pat: &'ast Pat) {
 168         let node = if let PatKind::Ident(..) = pat.node {
 169             NodeLocal(pat)
 170         } else {
 171             NodePat(pat)
 172         };
 173         self.insert(pat.id, node);
 174
 175         self.with_parent(pat.id, |this| {
 176             intravisit::walk_pat(this, pat);
 177         });
 178     }
 179
 180     fn visit_expr(&mut self, expr: &'ast Expr) {
 181         self.insert(expr.id, NodeExpr(expr));
 182
 183         self.with_parent(expr.id, |this| {
 184             intravisit::walk_expr(this, expr);
 185         });
 186     }
 187
 188     fn visit_stmt(&mut self, stmt: &'ast Stmt) {
 189         let id = stmt.node.id();
 190         self.insert(id, NodeStmt(stmt));
 191
 192         self.with_parent(id, |this| {
 193             intravisit::walk_stmt(this, stmt);
 194         });
 195     }
 196
 197     fn visit_fn(&mut self, fk: intravisit::FnKind<'ast>, fd: &'ast FnDecl,
 198                 b: &'ast Block, s: Span, id: NodeId) {
 199         assert_eq!(self.parent_node, id);
 200         intravisit::walk_fn(self, fk, fd, b, s);
 201     }
 202
 203     fn visit_block(&mut self, block: &'ast Block) {
 204         self.insert(block.id, NodeBlock(block));
 205         self.with_parent(block.id, |this| {
 206             intravisit::walk_block(this, block);
 207         });
 208     }
 209
 210     fn visit_lifetime(&mut self, lifetime: &'ast Lifetime) {
 211         self.insert(lifetime.id, NodeLifetime(lifetime));
 212     }
 213 }