src/librustc/ty/maps/plumbing.rs

   1 // Copyright 2012-2015 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 //! The implementation of the query system itself. Defines the macros
  12 //! that generate the actual methods on tcx which find and execute the
  13 //! provider, manage the caches, and so forth.
  14
  15 use dep_graph::{DepNodeIndex, DepNode, DepKind, DepNodeColor};
  16 use errors::{Diagnostic, DiagnosticBuilder};
  17 use ty::{TyCtxt};
  18 use ty::maps::Query; // NB: actually generated by the macros in this file
  19 use ty::maps::config::QueryDescription;
  20 use ty::item_path;
  21
  22 use rustc_data_structures::fx::{FxHashMap};
  23 use std::cell::{RefMut, Cell};
  24 use std::marker::PhantomData;
  25 use std::mem;
  26 use syntax_pos::Span;
  27
  28 pub(super) struct QueryMap<D: QueryDescription> {
  29     phantom: PhantomData<D>,
  30     pub(super) map: FxHashMap<D::Key, QueryValue<D::Value>>,
  31 }
  32
  33 pub(super) struct QueryValue<T> {
  34     pub(super) value: T,
  35     pub(super) index: DepNodeIndex,
  36     pub(super) diagnostics: Option<Box<QueryDiagnostics>>,
  37 }
  38
  39 impl<T> QueryValue<T> {
  40     pub(super) fn new(value: T,
  41                       dep_node_index: DepNodeIndex,
  42                       diagnostics: Vec<Diagnostic>)
  43                       -> QueryValue<T> {
  44         QueryValue {
  45             value,
  46             index: dep_node_index,
  47             diagnostics: if diagnostics.len() == 0 {
  48                 None
  49             } else {
  50                 Some(Box::new(QueryDiagnostics {
  51                     diagnostics,
  52                     emitted_diagnostics: Cell::new(true),
  53                 }))
  54             },
  55         }
  56     }
  57 }
  58
  59 pub(super) struct QueryDiagnostics {
  60     pub(super) diagnostics: Vec<Diagnostic>,
  61     pub(super) emitted_diagnostics: Cell<bool>,
  62 }
  63
  64 impl<M: QueryDescription> QueryMap<M> {
  65     pub(super) fn new() -> QueryMap<M> {
  66         QueryMap {
  67             phantom: PhantomData,
  68             map: FxHashMap(),
  69         }
  70     }
  71 }
  72
  73 pub(super) struct CycleError<'a, 'tcx: 'a> {
  74     span: Span,
  75     cycle: RefMut<'a, [(Span, Query<'tcx>)]>,
  76 }
  77
  78 impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
  79     pub(super) fn report_cycle(self, CycleError { span, cycle }: CycleError)
  80         -> DiagnosticBuilder<'a>
  81     {
  82         // Subtle: release the refcell lock before invoking `describe()`
  83         // below by dropping `cycle`.
  84         let stack = cycle.to_vec();
  85         mem::drop(cycle);
  86
  87         assert!(!stack.is_empty());
  88
  89         // Disable naming impls with types in this path, since that
  90         // sometimes cycles itself, leading to extra cycle errors.
  91         // (And cycle errors around impls tend to occur during the
  92         // collect/coherence phases anyhow.)
  93         item_path::with_forced_impl_filename_line(|| {
  94             let mut err =
  95                 struct_span_err!(self.sess, span, E0391,
  96                                  "unsupported cyclic reference between types/traits detected");
  97             err.span_label(span, "cyclic reference");
  98
  99             err.span_note(stack[0].0, &format!("the cycle begins when {}...",
 100                                                stack[0].1.describe(self)));
 101
 102             for &(span, ref query) in &stack[1..] {
 103                 err.span_note(span, &format!("...which then requires {}...",
 104                                              query.describe(self)));
 105             }
 106
 107             err.note(&format!("...which then again requires {}, completing the cycle.",
 108                               stack[0].1.describe(self)));
 109
 110             return err
 111         })
 112     }
 113
 114     pub(super) fn cycle_check<F, R>(self, span: Span, query: Query<'gcx>, compute: F)
 115                                     -> Result<R, CycleError<'a, 'gcx>>
 116         where F: FnOnce() -> R
 117     {
 118         {
 119             let mut stack = self.maps.query_stack.borrow_mut();
 120             if let Some((i, _)) = stack.iter().enumerate().rev()
 121                                        .find(|&(_, &(_, ref q))| *q == query) {
 122                 return Err(CycleError {
 123                     span,
 124                     cycle: RefMut::map(stack, |stack| &mut stack[i..])
 125                 });
 126             }
 127             stack.push((span, query));
 128         }
 129
 130         let result = compute();
 131
 132         self.maps.query_stack.borrow_mut().pop();
 133
 134         Ok(result)
 135     }
 136
 137     /// Try to read a node index for the node dep_node.
 138     /// A node will have an index, when it's already been marked green, or when we can mark it
 139     /// green. This function will mark the current task as a reader of the specified node, when
 140     /// the a node index can be found for that node.
 141     pub(super) fn try_mark_green_and_read(self, dep_node: &DepNode) -> Option<DepNodeIndex> {
 142         match self.dep_graph.node_color(dep_node) {
 143             Some(DepNodeColor::Green(dep_node_index)) => {
 144                 self.dep_graph.read_index(dep_node_index);
 145                 Some(dep_node_index)
 146             }
 147             Some(DepNodeColor::Red) => {
 148                 None
 149             }
 150             None => {
 151                 // try_mark_green (called below) will panic when full incremental
 152                 // compilation is disabled. If that's the case, we can't try to mark nodes
 153                 // as green anyway, so we can safely return None here.
 154                 if !self.dep_graph.is_fully_enabled() {
 155                     return None;
 156                 }
 157                 match self.dep_graph.try_mark_green(self, &dep_node) {
 158                     Some(dep_node_index) => {
 159                         debug_assert!(self.dep_graph.is_green(dep_node_index));
 160                         self.dep_graph.read_index(dep_node_index);
 161                         Some(dep_node_index)
 162                     }
 163                     None => {
 164                         None
 165                     }
 166                 }
 167             }
 168         }
 169     }
 170 }
 171
 172 // If enabled, send a message to the profile-queries thread
 173 macro_rules! profq_msg {
 174     ($tcx:expr, $msg:expr) => {
 175         if cfg!(debug_assertions) {
 176             if  $tcx.sess.profile_queries() {
 177                 profq_msg($msg)
 178             }
 179         }
 180     }
 181 }
 182
 183 // If enabled, format a key using its debug string, which can be
 184 // expensive to compute (in terms of time).
 185 macro_rules! profq_key {
 186     ($tcx:expr, $key:expr) => {
 187         if cfg!(debug_assertions) {
 188             if $tcx.sess.profile_queries_and_keys() {
 189                 Some(format!("{:?}", $key))
 190             } else { None }
 191         } else { None }
 192     }
 193 }
 194
 195 macro_rules! define_maps {
 196     (<$tcx:tt>
 197      $($(#[$attr:meta])*
 198        [$($modifiers:tt)*] fn $name:ident: $node:ident($K:ty) -> $V:ty,)*) => {
 199
 200         use dep_graph::DepNodeIndex;
 201         use std::cell::RefCell;
 202
 203         define_map_struct! {
 204             tcx: $tcx,
 205             input: ($(([$($modifiers)*] [$($attr)*] [$name]))*)
 206         }
 207
 208         impl<$tcx> Maps<$tcx> {
 209             pub fn new(providers: IndexVec<CrateNum, Providers<$tcx>>)
 210                        -> Self {
 211                 Maps {
 212                     providers,
 213                     query_stack: RefCell::new(vec![]),
 214                     $($name: RefCell::new(QueryMap::new())),*
 215                 }
 216             }
 217         }
 218
 219         #[allow(bad_style)]
 220         #[derive(Copy, Clone, Debug, PartialEq, Eq)]
 221         pub enum Query<$tcx> {
 222             $($(#[$attr])* $name($K)),*
 223         }
 224
 225         #[allow(bad_style)]
 226         #[derive(Clone, Debug, PartialEq, Eq)]
 227         pub enum QueryMsg {
 228             $($name(Option<String>)),*
 229         }
 230
 231         impl<$tcx> Query<$tcx> {
 232             pub fn describe(&self, tcx: TyCtxt) -> String {
 233                 let (r, name) = match *self {
 234                     $(Query::$name(key) => {
 235                         (queries::$name::describe(tcx, key), stringify!($name))
 236                     })*
 237                 };
 238                 if tcx.sess.verbose() {
 239                     format!("{} [{}]", r, name)
 240                 } else {
 241                     r
 242                 }
 243             }
 244         }
 245
 246         pub mod queries {
 247             use std::marker::PhantomData;
 248
 249             $(#[allow(bad_style)]
 250             pub struct $name<$tcx> {
 251                 data: PhantomData<&$tcx ()>
 252             })*
 253         }
 254
 255         $(impl<$tcx> QueryConfig for queries::$name<$tcx> {
 256             type Key = $K;
 257             type Value = $V;
 258         }
 259
 260         impl<'a, $tcx, 'lcx> queries::$name<$tcx> {
 261
 262             #[allow(unused)]
 263             fn to_dep_node(tcx: TyCtxt<'a, $tcx, 'lcx>, key: &$K) -> DepNode {
 264                 use dep_graph::DepConstructor::*;
 265
 266                 DepNode::new(tcx, $node(*key))
 267             }
 268
 269             fn try_get_with(tcx: TyCtxt<'a, $tcx, 'lcx>,
 270                             mut span: Span,
 271                             key: $K)
 272                             -> Result<$V, CycleError<'a, $tcx>>
 273             {
 274                 debug!("ty::queries::{}::try_get_with(key={:?}, span={:?})",
 275                        stringify!($name),
 276                        key,
 277                        span);
 278
 279                 profq_msg!(tcx,
 280                     ProfileQueriesMsg::QueryBegin(
 281                         span.data(),
 282                         QueryMsg::$name(profq_key!(tcx, key))
 283                     )
 284                 );
 285
 286                 if let Some(value) = tcx.maps.$name.borrow().map.get(&key) {
 287                     if let Some(ref d) = value.diagnostics {
 288                         if !d.emitted_diagnostics.get() {
 289                             d.emitted_diagnostics.set(true);
 290                             let handle = tcx.sess.diagnostic();
 291                             for diagnostic in d.diagnostics.iter() {
 292                                 DiagnosticBuilder::new_diagnostic(handle, diagnostic.clone())
 293                                     .emit();
 294                             }
 295                         }
 296                     }
 297                     profq_msg!(tcx, ProfileQueriesMsg::CacheHit);
 298                     tcx.dep_graph.read_index(value.index);
 299                     return Ok((&value.value).clone());
 300                 }
 301
 302                 // FIXME(eddyb) Get more valid Span's on queries.
 303                 // def_span guard is necessary to prevent a recursive loop,
 304                 // default_span calls def_span query internally.
 305                 if span == DUMMY_SP && stringify!($name) != "def_span" {
 306                     span = key.default_span(tcx)
 307                 }
 308
 309                 // Fast path for when incr. comp. is off. `to_dep_node` is
 310                 // expensive for some DepKinds.
 311                 if !tcx.dep_graph.is_fully_enabled() {
 312                     let null_dep_node = DepNode::new_no_params(::dep_graph::DepKind::Null);
 313                     return Self::force(tcx, key, span, null_dep_node)
 314                                 .map(|(v, _)| v);
 315                 }
 316
 317                 let dep_node = Self::to_dep_node(tcx, &key);
 318
 319                 if dep_node.kind.is_anon() {
 320                     profq_msg!(tcx, ProfileQueriesMsg::ProviderBegin);
 321
 322                     let res = tcx.cycle_check(span, Query::$name(key), || {
 323                         tcx.sess.diagnostic().track_diagnostics(|| {
 324                             tcx.dep_graph.with_anon_task(dep_node.kind, || {
 325                                 Self::compute_result(tcx.global_tcx(), key)
 326                             })
 327                         })
 328                     })?;
 329
 330                     profq_msg!(tcx, ProfileQueriesMsg::ProviderEnd);
 331                     let ((result, dep_node_index), diagnostics) = res;
 332
 333                     tcx.dep_graph.read_index(dep_node_index);
 334                     let value = QueryValue::new(result, dep_node_index, diagnostics);
 335
 336                     return Ok((&tcx.maps
 337                                     .$name
 338                                     .borrow_mut()
 339                                     .map
 340                                     .entry(key)
 341                                     .or_insert(value)
 342                                     .value).clone());
 343                 }
 344
 345                 if !dep_node.kind.is_input() {
 346                     if let Some(dep_node_index) = tcx.try_mark_green_and_read(&dep_node) {
 347                         profq_msg!(tcx, ProfileQueriesMsg::CacheHit);
 348                         return Self::load_from_disk_and_cache_in_memory(tcx,
 349                                                                         key,
 350                                                                         span,
 351                                                                         dep_node_index)
 352                     }
 353                 }
 354
 355                 match Self::force(tcx, key, span, dep_node) {
 356                     Ok((result, dep_node_index)) => {
 357                         tcx.dep_graph.read_index(dep_node_index);
 358                         Ok(result)
 359                     }
 360                     Err(e) => Err(e)
 361                 }
 362             }
 363
 364             /// Ensure that either this query has all green inputs or been executed.
 365             /// Executing query::ensure(D) is considered a read of the dep-node D.
 366             ///
 367             /// This function is particularly useful when executing passes for their
 368             /// side-effects -- e.g., in order to report errors for erroneous programs.
 369             ///
 370             /// Note: The optimization is only available during incr. comp.
 371             pub fn ensure(tcx: TyCtxt<'a, $tcx, 'lcx>, key: $K) -> () {
 372                 let dep_node = Self::to_dep_node(tcx, &key);
 373
 374                 // Ensuring an "input" or anonymous query makes no sense
 375                 assert!(!dep_node.kind.is_anon());
 376                 assert!(!dep_node.kind.is_input());
 377                 if tcx.try_mark_green_and_read(&dep_node).is_none() {
 378                     // A None return from `try_mark_green_and_read` means that this is either
 379                     // a new dep node or that the dep node has already been marked red.
 380                     // Either way, we can't call `dep_graph.read()` as we don't have the
 381                     // DepNodeIndex. We must invoke the query itself. The performance cost
 382                     // this introduces should be negligible as we'll immediately hit the
 383                     // in-memory cache, or another query down the line will.
 384                     let _ = tcx.$name(key);
 385                 }
 386             }
 387
 388             fn compute_result(tcx: TyCtxt<'a, $tcx, 'lcx>, key: $K) -> $V {
 389                 let provider = tcx.maps.providers[key.map_crate()].$name;
 390                 provider(tcx.global_tcx(), key)
 391             }
 392
 393             fn load_from_disk_and_cache_in_memory(tcx: TyCtxt<'a, $tcx, 'lcx>,
 394                                                   key: $K,
 395                                                   span: Span,
 396                                                   dep_node_index: DepNodeIndex)
 397                                                   -> Result<$V, CycleError<'a, $tcx>>
 398             {
 399                 debug_assert!(tcx.dep_graph.is_green(dep_node_index));
 400
 401                 // We don't do any caching yet, so recompute
 402                 let (result, diagnostics) = tcx.cycle_check(span, Query::$name(key), || {
 403                     tcx.sess.diagnostic().track_diagnostics(|| {
 404                         // The dep-graph for this computation is already in place
 405                         tcx.dep_graph.with_ignore(|| {
 406                             Self::compute_result(tcx, key)
 407                         })
 408                     })
 409                 })?;
 410
 411                 if tcx.sess.opts.debugging_opts.query_dep_graph {
 412                     tcx.dep_graph.mark_loaded_from_cache(dep_node_index, true);
 413                 }
 414
 415                 let value = QueryValue::new(result, dep_node_index, diagnostics);
 416
 417                 Ok((&tcx.maps
 418                          .$name
 419                          .borrow_mut()
 420                          .map
 421                          .entry(key)
 422                          .or_insert(value)
 423                          .value).clone())
 424             }
 425
 426             fn force(tcx: TyCtxt<'a, $tcx, 'lcx>,
 427                      key: $K,
 428                      span: Span,
 429                      dep_node: DepNode)
 430                      -> Result<($V, DepNodeIndex), CycleError<'a, $tcx>> {
 431                 debug_assert!(tcx.dep_graph.node_color(&dep_node).is_none());
 432
 433                 profq_msg!(tcx, ProfileQueriesMsg::ProviderBegin);
 434                 let res = tcx.cycle_check(span, Query::$name(key), || {
 435                     tcx.sess.diagnostic().track_diagnostics(|| {
 436                         if dep_node.kind.is_eval_always() {
 437                             tcx.dep_graph.with_eval_always_task(dep_node,
 438                                                                 tcx,
 439                                                                 key,
 440                                                                 Self::compute_result)
 441                         } else {
 442                             tcx.dep_graph.with_task(dep_node,
 443                                                     tcx,
 444                                                     key,
 445                                                     Self::compute_result)
 446                         }
 447                     })
 448                 })?;
 449                 profq_msg!(tcx, ProfileQueriesMsg::ProviderEnd);
 450
 451                 let ((result, dep_node_index), diagnostics) = res;
 452
 453                 if tcx.sess.opts.debugging_opts.query_dep_graph {
 454                     tcx.dep_graph.mark_loaded_from_cache(dep_node_index, false);
 455                 }
 456
 457                 let value = QueryValue::new(result, dep_node_index, diagnostics);
 458
 459                 Ok(((&tcx.maps
 460                          .$name
 461                          .borrow_mut()
 462                          .map
 463                          .entry(key)
 464                          .or_insert(value)
 465                          .value).clone(),
 466                    dep_node_index))
 467             }
 468
 469             pub fn try_get(tcx: TyCtxt<'a, $tcx, 'lcx>, span: Span, key: $K)
 470                            -> Result<$V, DiagnosticBuilder<'a>> {
 471                 match Self::try_get_with(tcx, span, key) {
 472                     Ok(e) => Ok(e),
 473                     Err(e) => Err(tcx.report_cycle(e)),
 474                 }
 475             }
 476         })*
 477
 478         #[derive(Copy, Clone)]
 479         pub struct TyCtxtAt<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
 480             pub tcx: TyCtxt<'a, 'gcx, 'tcx>,
 481             pub span: Span,
 482         }
 483
 484         impl<'a, 'gcx, 'tcx> Deref for TyCtxtAt<'a, 'gcx, 'tcx> {
 485             type Target = TyCtxt<'a, 'gcx, 'tcx>;
 486             fn deref(&self) -> &Self::Target {
 487                 &self.tcx
 488             }
 489         }
 490
 491         impl<'a, $tcx, 'lcx> TyCtxt<'a, $tcx, 'lcx> {
 492             /// Return a transparent wrapper for `TyCtxt` which uses
 493             /// `span` as the location of queries performed through it.
 494             pub fn at(self, span: Span) -> TyCtxtAt<'a, $tcx, 'lcx> {
 495                 TyCtxtAt {
 496                     tcx: self,
 497                     span
 498                 }
 499             }
 500
 501             $($(#[$attr])*
 502             pub fn $name(self, key: $K) -> $V {
 503                 self.at(DUMMY_SP).$name(key)
 504             })*
 505         }
 506
 507         impl<'a, $tcx, 'lcx> TyCtxtAt<'a, $tcx, 'lcx> {
 508             $($(#[$attr])*
 509             pub fn $name(self, key: $K) -> $V {
 510                 queries::$name::try_get(self.tcx, self.span, key).unwrap_or_else(|mut e| {
 511                     e.emit();
 512                     Value::from_cycle_error(self.global_tcx())
 513                 })
 514             })*
 515         }
 516
 517         define_provider_struct! {
 518             tcx: $tcx,
 519             input: ($(([$($modifiers)*] [$name] [$K] [$V]))*)
 520         }
 521
 522         impl<$tcx> Copy for Providers<$tcx> {}
 523         impl<$tcx> Clone for Providers<$tcx> {
 524             fn clone(&self) -> Self { *self }
 525         }
 526     }
 527 }
 528
 529 macro_rules! define_map_struct {
 530     (tcx: $tcx:tt,
 531      input: ($(([$(modifiers:tt)*] [$($attr:tt)*] [$name:ident]))*)) => {
 532         pub struct Maps<$tcx> {
 533             providers: IndexVec<CrateNum, Providers<$tcx>>,
 534             query_stack: RefCell<Vec<(Span, Query<$tcx>)>>,
 535             $($(#[$attr])*  $name: RefCell<QueryMap<queries::$name<$tcx>>>,)*
 536         }
 537     };
 538 }
 539
 540 macro_rules! define_provider_struct {
 541     (tcx: $tcx:tt,
 542      input: ($(([$($modifiers:tt)*] [$name:ident] [$K:ty] [$R:ty]))*)) => {
 543         pub struct Providers<$tcx> {
 544             $(pub $name: for<'a> fn(TyCtxt<'a, $tcx, $tcx>, $K) -> $R,)*
 545         }
 546
 547         impl<$tcx> Default for Providers<$tcx> {
 548             fn default() -> Self {
 549                 $(fn $name<'a, $tcx>(_: TyCtxt<'a, $tcx, $tcx>, key: $K) -> $R {
 550                     bug!("tcx.maps.{}({:?}) unsupported by its crate",
 551                          stringify!($name), key);
 552                 })*
 553                 Providers { $($name),* }
 554             }
 555         }
 556     };
 557 }
 558
 559
 560 /// The red/green evaluation system will try to mark a specific DepNode in the
 561 /// dependency graph as green by recursively trying to mark the dependencies of
 562 /// that DepNode as green. While doing so, it will sometimes encounter a DepNode
 563 /// where we don't know if it is red or green and we therefore actually have
 564 /// to recompute its value in order to find out. Since the only piece of
 565 /// information that we have at that point is the DepNode we are trying to
 566 /// re-evaluate, we need some way to re-run a query from just that. This is what
 567 /// `force_from_dep_node()` implements.
 568 ///
 569 /// In the general case, a DepNode consists of a DepKind and an opaque
 570 /// GUID/fingerprint that will uniquely identify the node. This GUID/fingerprint
 571 /// is usually constructed by computing a stable hash of the query-key that the
 572 /// DepNode corresponds to. Consequently, it is not in general possible to go
 573 /// back from hash to query-key (since hash functions are not reversible). For
 574 /// this reason `force_from_dep_node()` is expected to fail from time to time
 575 /// because we just cannot find out, from the DepNode alone, what the
 576 /// corresponding query-key is and therefore cannot re-run the query.
 577 ///
 578 /// The system deals with this case letting `try_mark_green` fail which forces
 579 /// the root query to be re-evaluated.
 580 ///
 581 /// Now, if force_from_dep_node() would always fail, it would be pretty useless.
 582 /// Fortunately, we can use some contextual information that will allow us to
 583 /// reconstruct query-keys for certain kinds of DepNodes. In particular, we
 584 /// enforce by construction that the GUID/fingerprint of certain DepNodes is a
 585 /// valid DefPathHash. Since we also always build a huge table that maps every
 586 /// DefPathHash in the current codebase to the corresponding DefId, we have
 587 /// everything we need to re-run the query.
 588 ///
 589 /// Take the `mir_validated` query as an example. Like many other queries, it
 590 /// just has a single parameter: the DefId of the item it will compute the
 591 /// validated MIR for. Now, when we call `force_from_dep_node()` on a dep-node
 592 /// with kind `MirValidated`, we know that the GUID/fingerprint of the dep-node
 593 /// is actually a DefPathHash, and can therefore just look up the corresponding
 594 /// DefId in `tcx.def_path_hash_to_def_id`.
 595 ///
 596 /// When you implement a new query, it will likely have a corresponding new
 597 /// DepKind, and you'll have to support it here in `force_from_dep_node()`. As
 598 /// a rule of thumb, if your query takes a DefId or DefIndex as sole parameter,
 599 /// then `force_from_dep_node()` should not fail for it. Otherwise, you can just
 600 /// add it to the "We don't have enough information to reconstruct..." group in
 601 /// the match below.
 602 pub fn force_from_dep_node<'a, 'gcx, 'lcx>(tcx: TyCtxt<'a, 'gcx, 'lcx>,
 603                                            dep_node: &DepNode)
 604                                            -> bool {
 605     use ty::maps::keys::Key;
 606     use hir::def_id::LOCAL_CRATE;
 607
 608     // We must avoid ever having to call force_from_dep_node() for a
 609     // DepNode::CodegenUnit:
 610     // Since we cannot reconstruct the query key of a DepNode::CodegenUnit, we
 611     // would always end up having to evaluate the first caller of the
 612     // `codegen_unit` query that *is* reconstructible. This might very well be
 613     // the `compile_codegen_unit` query, thus re-translating the whole CGU just
 614     // to re-trigger calling the `codegen_unit` query with the right key. At
 615     // that point we would already have re-done all the work we are trying to
 616     // avoid doing in the first place.
 617     // The solution is simple: Just explicitly call the `codegen_unit` query for
 618     // each CGU, right after partitioning. This way `try_mark_green` will always
 619     // hit the cache instead of having to go through `force_from_dep_node`.
 620     // This assertion makes sure, we actually keep applying the solution above.
 621     debug_assert!(dep_node.kind != DepKind::CodegenUnit,
 622                   "calling force_from_dep_node() on DepKind::CodegenUnit");
 623
 624     if !dep_node.kind.can_reconstruct_query_key() {
 625         return false
 626     }
 627
 628     macro_rules! def_id {
 629         () => {
 630             if let Some(def_id) = dep_node.extract_def_id(tcx) {
 631                 def_id
 632             } else {
 633                 // return from the whole function
 634                 return false
 635             }
 636         }
 637     };
 638
 639     macro_rules! krate {
 640         () => { (def_id!()).krate }
 641     };
 642
 643     macro_rules! force {
 644         ($query:ident, $key:expr) => {
 645             {
 646                 use $crate::util::common::{ProfileQueriesMsg, profq_msg};
 647
 648                 // FIXME(eddyb) Get more valid Span's on queries.
 649                 // def_span guard is necessary to prevent a recursive loop,
 650                 // default_span calls def_span query internally.
 651                 let span = if stringify!($query) != "def_span" {
 652                     $key.default_span(tcx)
 653                 } else {
 654                     ::syntax_pos::DUMMY_SP
 655                 };
 656
 657                 profq_msg!(tcx,
 658                     ProfileQueriesMsg::QueryBegin(
 659                         span.data(),
 660                         ::ty::maps::QueryMsg::$query(profq_key!(tcx, $key))
 661                     )
 662                 );
 663
 664                 match ::ty::maps::queries::$query::force(tcx, $key, span, *dep_node) {
 665                     Ok(_) => {},
 666                     Err(e) => {
 667                         tcx.report_cycle(e).emit();
 668                     }
 669                 }
 670             }
 671         }
 672     };
 673
 674     // FIXME(#45015): We should try move this boilerplate code into a macro
 675     //                somehow.
 676     match dep_node.kind {
 677         // These are inputs that are expected to be pre-allocated and that
 678         // should therefore always be red or green already
 679         DepKind::AllLocalTraitImpls |
 680         DepKind::Krate |
 681         DepKind::CrateMetadata |
 682         DepKind::HirBody |
 683         DepKind::Hir |
 684
 685         // This are anonymous nodes
 686         DepKind::TraitSelect |
 687
 688         // We don't have enough information to reconstruct the query key of
 689         // these
 690         DepKind::IsCopy |
 691         DepKind::IsSized |
 692         DepKind::IsFreeze |
 693         DepKind::NeedsDrop |
 694         DepKind::Layout |
 695         DepKind::ConstEval |
 696         DepKind::InstanceSymbolName |
 697         DepKind::MirShim |
 698         DepKind::BorrowCheckKrate |
 699         DepKind::Specializes |
 700         DepKind::ImplementationsOfTrait |
 701         DepKind::TypeParamPredicates |
 702         DepKind::CodegenUnit |
 703         DepKind::CompileCodegenUnit |
 704         DepKind::FulfillObligation |
 705         DepKind::VtableMethods |
 706         DepKind::EraseRegionsTy |
 707         DepKind::NormalizeTy |
 708
 709         // These are just odd
 710         DepKind::Null |
 711         DepKind::WorkProduct => {
 712             bug!("force_from_dep_node() - Encountered {:?}", dep_node.kind)
 713         }
 714
 715         // These are not queries
 716         DepKind::CoherenceCheckTrait |
 717         DepKind::ItemVarianceConstraints => {
 718             return false
 719         }
 720
 721         DepKind::RegionScopeTree => { force!(region_scope_tree, def_id!()); }
 722
 723         DepKind::Coherence => { force!(crate_inherent_impls, LOCAL_CRATE); }
 724         DepKind::CoherenceInherentImplOverlapCheck => {
 725             force!(crate_inherent_impls_overlap_check, LOCAL_CRATE)
 726         },
 727         DepKind::PrivacyAccessLevels => { force!(privacy_access_levels, LOCAL_CRATE); }
 728         DepKind::MirConstQualif => { force!(mir_const_qualif, def_id!()); }
 729         DepKind::MirConst => { force!(mir_const, def_id!()); }
 730         DepKind::MirValidated => { force!(mir_validated, def_id!()); }
 731         DepKind::MirOptimized => { force!(optimized_mir, def_id!()); }
 732
 733         DepKind::BorrowCheck => { force!(borrowck, def_id!()); }
 734         DepKind::MirBorrowCheck => { force!(mir_borrowck, def_id!()); }
 735         DepKind::UnsafetyViolations => { force!(unsafety_violations, def_id!()); }
 736         DepKind::Reachability => { force!(reachable_set, LOCAL_CRATE); }
 737         DepKind::MirKeys => { force!(mir_keys, LOCAL_CRATE); }
 738         DepKind::CrateVariances => { force!(crate_variances, LOCAL_CRATE); }
 739         DepKind::AssociatedItems => { force!(associated_item, def_id!()); }
 740         DepKind::TypeOfItem => { force!(type_of, def_id!()); }
 741         DepKind::GenericsOfItem => { force!(generics_of, def_id!()); }
 742         DepKind::PredicatesOfItem => { force!(predicates_of, def_id!()); }
 743         DepKind::InferredOutlivesOf => { force!(inferred_outlives_of, def_id!()); }
 744         DepKind::SuperPredicatesOfItem => { force!(super_predicates_of, def_id!()); }
 745         DepKind::TraitDefOfItem => { force!(trait_def, def_id!()); }
 746         DepKind::AdtDefOfItem => { force!(adt_def, def_id!()); }
 747         DepKind::IsDefaultImpl => { force!(is_default_impl, def_id!()); }
 748         DepKind::ImplTraitRef => { force!(impl_trait_ref, def_id!()); }
 749         DepKind::ImplPolarity => { force!(impl_polarity, def_id!()); }
 750         DepKind::ClosureKind => { force!(closure_kind, def_id!()); }
 751         DepKind::FnSignature => { force!(fn_sig, def_id!()); }
 752         DepKind::GenSignature => { force!(generator_sig, def_id!()); }
 753         DepKind::CoerceUnsizedInfo => { force!(coerce_unsized_info, def_id!()); }
 754         DepKind::ItemVariances => { force!(variances_of, def_id!()); }
 755         DepKind::IsConstFn => { force!(is_const_fn, def_id!()); }
 756         DepKind::IsForeignItem => { force!(is_foreign_item, def_id!()); }
 757         DepKind::SizedConstraint => { force!(adt_sized_constraint, def_id!()); }
 758         DepKind::DtorckConstraint => { force!(adt_dtorck_constraint, def_id!()); }
 759         DepKind::AdtDestructor => { force!(adt_destructor, def_id!()); }
 760         DepKind::AssociatedItemDefIds => { force!(associated_item_def_ids, def_id!()); }
 761         DepKind::InherentImpls => { force!(inherent_impls, def_id!()); }
 762         DepKind::TypeckBodiesKrate => { force!(typeck_item_bodies, LOCAL_CRATE); }
 763         DepKind::TypeckTables => { force!(typeck_tables_of, def_id!()); }
 764         DepKind::UsedTraitImports => { force!(used_trait_imports, def_id!()); }
 765         DepKind::HasTypeckTables => { force!(has_typeck_tables, def_id!()); }
 766         DepKind::SymbolName => { force!(def_symbol_name, def_id!()); }
 767         DepKind::SpecializationGraph => { force!(specialization_graph_of, def_id!()); }
 768         DepKind::ObjectSafety => { force!(is_object_safe, def_id!()); }
 769         DepKind::TraitImpls => { force!(trait_impls_of, def_id!()); }
 770
 771         DepKind::ParamEnv => { force!(param_env, def_id!()); }
 772         DepKind::DescribeDef => { force!(describe_def, def_id!()); }
 773         DepKind::DefSpan => { force!(def_span, def_id!()); }
 774         DepKind::LookupStability => { force!(lookup_stability, def_id!()); }
 775         DepKind::LookupDeprecationEntry => {
 776             force!(lookup_deprecation_entry, def_id!());
 777         }
 778         DepKind::ItemBodyNestedBodies => { force!(item_body_nested_bodies, def_id!()); }
 779         DepKind::ConstIsRvaluePromotableToStatic => {
 780             force!(const_is_rvalue_promotable_to_static, def_id!());
 781         }
 782         DepKind::RvaluePromotableMap => { force!(rvalue_promotable_map, def_id!()); }
 783         DepKind::ImplParent => { force!(impl_parent, def_id!()); }
 784         DepKind::TraitOfItem => { force!(trait_of_item, def_id!()); }
 785         DepKind::IsExportedSymbol => { force!(is_exported_symbol, def_id!()); }
 786         DepKind::IsMirAvailable => { force!(is_mir_available, def_id!()); }
 787         DepKind::ItemAttrs => { force!(item_attrs, def_id!()); }
 788         DepKind::FnArgNames => { force!(fn_arg_names, def_id!()); }
 789         DepKind::DylibDepFormats => { force!(dylib_dependency_formats, krate!()); }
 790         DepKind::IsPanicRuntime => { force!(is_panic_runtime, krate!()); }
 791         DepKind::IsCompilerBuiltins => { force!(is_compiler_builtins, krate!()); }
 792         DepKind::HasGlobalAllocator => { force!(has_global_allocator, krate!()); }
 793         DepKind::ExternCrate => { force!(extern_crate, def_id!()); }
 794         DepKind::LintLevels => { force!(lint_levels, LOCAL_CRATE); }
 795         DepKind::InScopeTraits => { force!(in_scope_traits_map, def_id!().index); }
 796         DepKind::ModuleExports => { force!(module_exports, def_id!()); }
 797         DepKind::IsSanitizerRuntime => { force!(is_sanitizer_runtime, krate!()); }
 798         DepKind::IsProfilerRuntime => { force!(is_profiler_runtime, krate!()); }
 799         DepKind::GetPanicStrategy => { force!(panic_strategy, krate!()); }
 800         DepKind::IsNoBuiltins => { force!(is_no_builtins, krate!()); }
 801         DepKind::ImplDefaultness => { force!(impl_defaultness, def_id!()); }
 802         DepKind::ExportedSymbolIds => { force!(exported_symbol_ids, krate!()); }
 803         DepKind::NativeLibraries => { force!(native_libraries, krate!()); }
 804         DepKind::PluginRegistrarFn => { force!(plugin_registrar_fn, krate!()); }
 805         DepKind::DeriveRegistrarFn => { force!(derive_registrar_fn, krate!()); }
 806         DepKind::CrateDisambiguator => { force!(crate_disambiguator, krate!()); }
 807         DepKind::CrateHash => { force!(crate_hash, krate!()); }
 808         DepKind::OriginalCrateName => { force!(original_crate_name, krate!()); }
 809
 810         DepKind::AllTraitImplementations => {
 811             force!(all_trait_implementations, krate!());
 812         }
 813
 814         DepKind::IsDllimportForeignItem => {
 815             force!(is_dllimport_foreign_item, def_id!());
 816         }
 817         DepKind::IsStaticallyIncludedForeignItem => {
 818             force!(is_statically_included_foreign_item, def_id!());
 819         }
 820         DepKind::NativeLibraryKind => { force!(native_library_kind, def_id!()); }
 821         DepKind::LinkArgs => { force!(link_args, LOCAL_CRATE); }
 822
 823         DepKind::NamedRegion => { force!(named_region_map, def_id!().index); }
 824         DepKind::IsLateBound => { force!(is_late_bound_map, def_id!().index); }
 825         DepKind::ObjectLifetimeDefaults => {
 826             force!(object_lifetime_defaults_map, def_id!().index);
 827         }
 828
 829         DepKind::Visibility => { force!(visibility, def_id!()); }
 830         DepKind::DepKind => { force!(dep_kind, krate!()); }
 831         DepKind::CrateName => { force!(crate_name, krate!()); }
 832         DepKind::ItemChildren => { force!(item_children, def_id!()); }
 833         DepKind::ExternModStmtCnum => { force!(extern_mod_stmt_cnum, def_id!()); }
 834         DepKind::GetLangItems => { force!(get_lang_items, LOCAL_CRATE); }
 835         DepKind::DefinedLangItems => { force!(defined_lang_items, krate!()); }
 836         DepKind::MissingLangItems => { force!(missing_lang_items, krate!()); }
 837         DepKind::ExternConstBody => { force!(extern_const_body, def_id!()); }
 838         DepKind::VisibleParentMap => { force!(visible_parent_map, LOCAL_CRATE); }
 839         DepKind::MissingExternCrateItem => {
 840             force!(missing_extern_crate_item, krate!());
 841         }
 842         DepKind::UsedCrateSource => { force!(used_crate_source, krate!()); }
 843         DepKind::PostorderCnums => { force!(postorder_cnums, LOCAL_CRATE); }
 844         DepKind::HasCloneClosures => { force!(has_clone_closures, krate!()); }
 845         DepKind::HasCopyClosures => { force!(has_copy_closures, krate!()); }
 846
 847         DepKind::Freevars => { force!(freevars, def_id!()); }
 848         DepKind::MaybeUnusedTraitImport => {
 849             force!(maybe_unused_trait_import, def_id!());
 850         }
 851         DepKind::MaybeUnusedExternCrates => { force!(maybe_unused_extern_crates, LOCAL_CRATE); }
 852         DepKind::StabilityIndex => { force!(stability_index, LOCAL_CRATE); }
 853         DepKind::AllCrateNums => { force!(all_crate_nums, LOCAL_CRATE); }
 854         DepKind::ExportedSymbols => { force!(exported_symbols, krate!()); }
 855         DepKind::CollectAndPartitionTranslationItems => {
 856             force!(collect_and_partition_translation_items, LOCAL_CRATE);
 857         }
 858         DepKind::ExportName => { force!(export_name, def_id!()); }
 859         DepKind::ContainsExternIndicator => {
 860             force!(contains_extern_indicator, def_id!());
 861         }
 862         DepKind::IsTranslatedFunction => { force!(is_translated_function, def_id!()); }
 863         DepKind::OutputFilenames => { force!(output_filenames, LOCAL_CRATE); }
 864     }
 865
 866     true
 867 }
 868