compiler/rustc_passes/src/hir_stats.rs

   1 // The visitors in this module collect sizes and counts of the most important
   2 // pieces of AST and HIR. The resulting numbers are good approximations but not
   3 // completely accurate (some things might be counted twice, others missed).
   4
   5 use rustc_ast::visit as ast_visit;
   6 use rustc_ast::{self as ast, AttrId, NodeId};
   7 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
   8 use rustc_hir as hir;
   9 use rustc_hir::intravisit as hir_visit;
  10 use rustc_hir::HirId;
  11 use rustc_middle::hir::map::Map;
  12 use rustc_middle::util::common::to_readable_str;
  13 use rustc_span::Span;
  14
  15 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
  16 enum Id {
  17     Node(HirId),
  18     Attr(AttrId),
  19     None,
  20 }
  21
  22 struct NodeData {
  23     count: usize,
  24     size: usize,
  25 }
  26
  27 struct StatCollector<'k> {
  28     krate: Option<&'k hir::Crate<'k>>,
  29     data: FxHashMap<&'static str, NodeData>,
  30     seen: FxHashSet<Id>,
  31 }
  32
  33 pub fn print_hir_stats(krate: &hir::Crate<'_>) {
  34     let mut collector = StatCollector {
  35         krate: Some(krate),
  36         data: FxHashMap::default(),
  37         seen: FxHashSet::default(),
  38     };
  39     hir_visit::walk_crate(&mut collector, krate);
  40     collector.print("HIR STATS");
  41 }
  42
  43 pub fn print_ast_stats(krate: &ast::Crate, title: &str) {
  44     let mut collector =
  45         StatCollector { krate: None, data: FxHashMap::default(), seen: FxHashSet::default() };
  46     ast_visit::walk_crate(&mut collector, krate);
  47     collector.print(title);
  48 }
  49
  50 impl<'k> StatCollector<'k> {
  51     fn record<T>(&mut self, label: &'static str, id: Id, node: &T) {
  52         if id != Id::None && !self.seen.insert(id) {
  53             return;
  54         }
  55
  56         let entry = self.data.entry(label).or_insert(NodeData { count: 0, size: 0 });
  57
  58         entry.count += 1;
  59         entry.size = std::mem::size_of_val(node);
  60     }
  61
  62     fn print(&self, title: &str) {
  63         let mut stats: Vec<_> = self.data.iter().collect();
  64
  65         stats.sort_by_key(|&(_, ref d)| d.count * d.size);
  66
  67         let mut total_size = 0;
  68
  69         eprintln!("\n{}\n", title);
  70
  71         eprintln!("{:<18}{:>18}{:>14}{:>14}", "Name", "Accumulated Size", "Count", "Item Size");
  72         eprintln!("----------------------------------------------------------------");
  73
  74         for (label, data) in stats {
  75             eprintln!(
  76                 "{:<18}{:>18}{:>14}{:>14}",
  77                 label,
  78                 to_readable_str(data.count * data.size),
  79                 to_readable_str(data.count),
  80                 to_readable_str(data.size)
  81             );
  82
  83             total_size += data.count * data.size;
  84         }
  85         eprintln!("----------------------------------------------------------------");
  86         eprintln!("{:<18}{:>18}\n", "Total", to_readable_str(total_size));
  87     }
  88 }
  89
  90 impl<'v> hir_visit::Visitor<'v> for StatCollector<'v> {
  91     fn visit_param(&mut self, param: &'v hir::Param<'v>) {
  92         self.record("Param", Id::Node(param.hir_id), param);
  93         hir_visit::walk_param(self, param)
  94     }
  95
  96     type Map = Map<'v>;
  97
  98     fn nested_visit_map(&mut self) -> hir_visit::NestedVisitorMap<Self::Map> {
  99         panic!("visit_nested_xxx must be manually implemented in this visitor")
 100     }
 101
 102     fn visit_nested_item(&mut self, id: hir::ItemId) {
 103         let nested_item = self.krate.unwrap().item(id);
 104         self.visit_item(nested_item)
 105     }
 106
 107     fn visit_nested_trait_item(&mut self, trait_item_id: hir::TraitItemId) {
 108         let nested_trait_item = self.krate.unwrap().trait_item(trait_item_id);
 109         self.visit_trait_item(nested_trait_item)
 110     }
 111
 112     fn visit_nested_impl_item(&mut self, impl_item_id: hir::ImplItemId) {
 113         let nested_impl_item = self.krate.unwrap().impl_item(impl_item_id);
 114         self.visit_impl_item(nested_impl_item)
 115     }
 116
 117     fn visit_nested_foreign_item(&mut self, id: hir::ForeignItemId) {
 118         let nested_foreign_item = self.krate.unwrap().foreign_item(id);
 119         self.visit_foreign_item(nested_foreign_item);
 120     }
 121
 122     fn visit_nested_body(&mut self, body_id: hir::BodyId) {
 123         let nested_body = self.krate.unwrap().body(body_id);
 124         self.visit_body(nested_body)
 125     }
 126
 127     fn visit_item(&mut self, i: &'v hir::Item<'v>) {
 128         self.record("Item", Id::Node(i.hir_id()), i);
 129         hir_visit::walk_item(self, i)
 130     }
 131
 132     fn visit_foreign_item(&mut self, i: &'v hir::ForeignItem<'v>) {
 133         self.record("ForeignItem", Id::Node(i.hir_id()), i);
 134         hir_visit::walk_foreign_item(self, i)
 135     }
 136
 137     fn visit_local(&mut self, l: &'v hir::Local<'v>) {
 138         self.record("Local", Id::Node(l.hir_id), l);
 139         hir_visit::walk_local(self, l)
 140     }
 141
 142     fn visit_block(&mut self, b: &'v hir::Block<'v>) {
 143         self.record("Block", Id::Node(b.hir_id), b);
 144         hir_visit::walk_block(self, b)
 145     }
 146
 147     fn visit_stmt(&mut self, s: &'v hir::Stmt<'v>) {
 148         self.record("Stmt", Id::Node(s.hir_id), s);
 149         hir_visit::walk_stmt(self, s)
 150     }
 151
 152     fn visit_arm(&mut self, a: &'v hir::Arm<'v>) {
 153         self.record("Arm", Id::Node(a.hir_id), a);
 154         hir_visit::walk_arm(self, a)
 155     }
 156
 157     fn visit_pat(&mut self, p: &'v hir::Pat<'v>) {
 158         self.record("Pat", Id::Node(p.hir_id), p);
 159         hir_visit::walk_pat(self, p)
 160     }
 161
 162     fn visit_expr(&mut self, ex: &'v hir::Expr<'v>) {
 163         self.record("Expr", Id::Node(ex.hir_id), ex);
 164         hir_visit::walk_expr(self, ex)
 165     }
 166
 167     fn visit_ty(&mut self, t: &'v hir::Ty<'v>) {
 168         self.record("Ty", Id::Node(t.hir_id), t);
 169         hir_visit::walk_ty(self, t)
 170     }
 171
 172     fn visit_fn(
 173         &mut self,
 174         fk: hir_visit::FnKind<'v>,
 175         fd: &'v hir::FnDecl<'v>,
 176         b: hir::BodyId,
 177         s: Span,
 178         id: hir::HirId,
 179     ) {
 180         self.record("FnDecl", Id::None, fd);
 181         hir_visit::walk_fn(self, fk, fd, b, s, id)
 182     }
 183
 184     fn visit_where_predicate(&mut self, predicate: &'v hir::WherePredicate<'v>) {
 185         self.record("WherePredicate", Id::None, predicate);
 186         hir_visit::walk_where_predicate(self, predicate)
 187     }
 188
 189     fn visit_trait_item(&mut self, ti: &'v hir::TraitItem<'v>) {
 190         self.record("TraitItem", Id::Node(ti.hir_id()), ti);
 191         hir_visit::walk_trait_item(self, ti)
 192     }
 193
 194     fn visit_impl_item(&mut self, ii: &'v hir::ImplItem<'v>) {
 195         self.record("ImplItem", Id::Node(ii.hir_id()), ii);
 196         hir_visit::walk_impl_item(self, ii)
 197     }
 198
 199     fn visit_param_bound(&mut self, bounds: &'v hir::GenericBound<'v>) {
 200         self.record("GenericBound", Id::None, bounds);
 201         hir_visit::walk_param_bound(self, bounds)
 202     }
 203
 204     fn visit_field_def(&mut self, s: &'v hir::FieldDef<'v>) {
 205         self.record("FieldDef", Id::Node(s.hir_id), s);
 206         hir_visit::walk_field_def(self, s)
 207     }
 208
 209     fn visit_variant(
 210         &mut self,
 211         v: &'v hir::Variant<'v>,
 212         g: &'v hir::Generics<'v>,
 213         item_id: hir::HirId,
 214     ) {
 215         self.record("Variant", Id::None, v);
 216         hir_visit::walk_variant(self, v, g, item_id)
 217     }
 218
 219     fn visit_lifetime(&mut self, lifetime: &'v hir::Lifetime) {
 220         self.record("Lifetime", Id::Node(lifetime.hir_id), lifetime);
 221         hir_visit::walk_lifetime(self, lifetime)
 222     }
 223
 224     fn visit_qpath(&mut self, qpath: &'v hir::QPath<'v>, id: hir::HirId, span: Span) {
 225         self.record("QPath", Id::None, qpath);
 226         hir_visit::walk_qpath(self, qpath, id, span)
 227     }
 228
 229     fn visit_path(&mut self, path: &'v hir::Path<'v>, _id: hir::HirId) {
 230         self.record("Path", Id::None, path);
 231         hir_visit::walk_path(self, path)
 232     }
 233
 234     fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v hir::PathSegment<'v>) {
 235         self.record("PathSegment", Id::None, path_segment);
 236         hir_visit::walk_path_segment(self, path_span, path_segment)
 237     }
 238
 239     fn visit_assoc_type_binding(&mut self, type_binding: &'v hir::TypeBinding<'v>) {
 240         self.record("TypeBinding", Id::Node(type_binding.hir_id), type_binding);
 241         hir_visit::walk_assoc_type_binding(self, type_binding)
 242     }
 243
 244     fn visit_attribute(&mut self, _: hir::HirId, attr: &'v ast::Attribute) {
 245         self.record("Attribute", Id::Attr(attr.id), attr);
 246     }
 247 }
 248
 249 impl<'v> ast_visit::Visitor<'v> for StatCollector<'v> {
 250     fn visit_foreign_item(&mut self, i: &'v ast::ForeignItem) {
 251         self.record("ForeignItem", Id::None, i);
 252         ast_visit::walk_foreign_item(self, i)
 253     }
 254
 255     fn visit_item(&mut self, i: &'v ast::Item) {
 256         self.record("Item", Id::None, i);
 257         ast_visit::walk_item(self, i)
 258     }
 259
 260     fn visit_local(&mut self, l: &'v ast::Local) {
 261         self.record("Local", Id::None, l);
 262         ast_visit::walk_local(self, l)
 263     }
 264
 265     fn visit_block(&mut self, b: &'v ast::Block) {
 266         self.record("Block", Id::None, b);
 267         ast_visit::walk_block(self, b)
 268     }
 269
 270     fn visit_stmt(&mut self, s: &'v ast::Stmt) {
 271         self.record("Stmt", Id::None, s);
 272         ast_visit::walk_stmt(self, s)
 273     }
 274
 275     fn visit_arm(&mut self, a: &'v ast::Arm) {
 276         self.record("Arm", Id::None, a);
 277         ast_visit::walk_arm(self, a)
 278     }
 279
 280     fn visit_pat(&mut self, p: &'v ast::Pat) {
 281         self.record("Pat", Id::None, p);
 282         ast_visit::walk_pat(self, p)
 283     }
 284
 285     fn visit_expr(&mut self, ex: &'v ast::Expr) {
 286         self.record("Expr", Id::None, ex);
 287         ast_visit::walk_expr(self, ex)
 288     }
 289
 290     fn visit_ty(&mut self, t: &'v ast::Ty) {
 291         self.record("Ty", Id::None, t);
 292         ast_visit::walk_ty(self, t)
 293     }
 294
 295     fn visit_fn(&mut self, fk: ast_visit::FnKind<'v>, s: Span, _: NodeId) {
 296         self.record("FnDecl", Id::None, fk.decl());
 297         ast_visit::walk_fn(self, fk, s)
 298     }
 299
 300     fn visit_assoc_item(&mut self, item: &'v ast::AssocItem, ctxt: ast_visit::AssocCtxt) {
 301         let label = match ctxt {
 302             ast_visit::AssocCtxt::Trait => "TraitItem",
 303             ast_visit::AssocCtxt::Impl => "ImplItem",
 304         };
 305         self.record(label, Id::None, item);
 306         ast_visit::walk_assoc_item(self, item, ctxt);
 307     }
 308
 309     fn visit_param_bound(&mut self, bounds: &'v ast::GenericBound) {
 310         self.record("GenericBound", Id::None, bounds);
 311         ast_visit::walk_param_bound(self, bounds)
 312     }
 313
 314     fn visit_field_def(&mut self, s: &'v ast::FieldDef) {
 315         self.record("FieldDef", Id::None, s);
 316         ast_visit::walk_field_def(self, s)
 317     }
 318
 319     fn visit_variant(&mut self, v: &'v ast::Variant) {
 320         self.record("Variant", Id::None, v);
 321         ast_visit::walk_variant(self, v)
 322     }
 323
 324     fn visit_lifetime(&mut self, lifetime: &'v ast::Lifetime) {
 325         self.record("Lifetime", Id::None, lifetime);
 326         ast_visit::walk_lifetime(self, lifetime)
 327     }
 328
 329     fn visit_mac_call(&mut self, mac: &'v ast::MacCall) {
 330         self.record("MacCall", Id::None, mac);
 331         ast_visit::walk_mac(self, mac)
 332     }
 333
 334     fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v ast::PathSegment) {
 335         self.record("PathSegment", Id::None, path_segment);
 336         ast_visit::walk_path_segment(self, path_span, path_segment)
 337     }
 338
 339     fn visit_assoc_ty_constraint(&mut self, constraint: &'v ast::AssocTyConstraint) {
 340         self.record("AssocTyConstraint", Id::None, constraint);
 341         ast_visit::walk_assoc_ty_constraint(self, constraint)
 342     }
 343
 344     fn visit_attribute(&mut self, attr: &'v ast::Attribute) {
 345         self.record("Attribute", Id::None, attr);
 346     }
 347 }