Auto merge of #51550 - eddyb:queries-not-maps, r=nikomatsakis

rustc: rename ty::maps to ty::query.

Should've never been `maps` but "query system/engine" didn't fully settle from the start.

r? @michaelwoerister or @nikomatsakis

Author: bors

src/README.md

@@ -6,7 +6,7 @@ This directory contains the source code of the rust project, including:
 For more information on how various parts of the compiler work, see the [rustc guide].
 
 Their is also useful content in the following READMEs, which are gradually being moved over to the guide:
-- https://github.com/rust-lang/rust/tree/master/src/librustc/ty/maps
+- https://github.com/rust-lang/rust/tree/master/src/librustc/ty/query
 - https://github.com/rust-lang/rust/tree/master/src/librustc/dep_graph
 - https://github.com/rust-lang/rust/blob/master/src/librustc/infer/region_constraints
 - https://github.com/rust-lang/rust/tree/master/src/librustc/infer/higher_ranked

src/librustc/dep_graph/graph.rs

@@ -656,7 +656,7 @@ impl DepGraph {
                     // We failed to mark it green, so we try to force the query.
                     debug!("try_mark_green({:?}) --- trying to force \
                             dependency {:?}", dep_node, dep_dep_node);
-                    if ::ty::maps::force_from_dep_node(tcx, dep_dep_node) {
+                    if ::ty::query::force_from_dep_node(tcx, dep_dep_node) {
                         let dep_dep_node_color = data.colors.borrow().get(dep_dep_node_index);
 
                         match dep_dep_node_color {
@@ -742,14 +742,14 @@ impl DepGraph {
             // and emit other diagnostics before these diagnostics are emitted.
             // Such diagnostics should be emitted after these.
             // See https://github.com/rust-lang/rust/issues/48685
-            let diagnostics = tcx.on_disk_query_result_cache
+            let diagnostics = tcx.queries.on_disk_cache
                                  .load_diagnostics(tcx, prev_dep_node_index);
 
             if diagnostics.len() > 0 {
                 let handle = tcx.sess.diagnostic();
 
                 // Promote the previous diagnostics to the current session.
-                tcx.on_disk_query_result_cache
+                tcx.queries.on_disk_cache
                    .store_diagnostics(dep_node_index, diagnostics.clone());
 
                 for diagnostic in diagnostics {

src/librustc/hir/mod.rs

@@ -45,7 +45,7 @@ use syntax::tokenstream::TokenStream;
 use syntax::util::ThinVec;
 use syntax::util::parser::ExprPrecedence;
 use ty::AdtKind;
-use ty::maps::Providers;
+use ty::query::Providers;
 
 use rustc_data_structures::indexed_vec;
 use rustc_data_structures::sync::{ParallelIterator, par_iter, Send, Sync, scope};

src/librustc/lint/mod.rs

@@ -47,7 +47,7 @@ use syntax::symbol::Symbol;
 use syntax::visit as ast_visit;
 use syntax_pos::Span;
 use ty::TyCtxt;
-use ty::maps::Providers;
+use ty::query::Providers;
 use util::nodemap::NodeMap;
 
 pub use lint::context::{LateContext, EarlyContext, LintContext, LintStore,

src/librustc/middle/const_val.rs

@@ -11,7 +11,7 @@
 use hir::def_id::DefId;
 use ty;
 use ty::subst::Substs;
-use ty::maps::TyCtxtAt;
+use ty::query::TyCtxtAt;
 use mir::interpret::ConstValue;
 use errors::DiagnosticBuilder;
 

src/librustc/middle/reachable.rs

@@ -21,7 +21,7 @@ use hir::def::Def;
 use hir::def_id::{DefId, CrateNum};
 use rustc_data_structures::sync::Lrc;
 use ty::{self, TyCtxt};
-use ty::maps::Providers;
+use ty::query::Providers;
 use middle::privacy;
 use session::config;
 use util::nodemap::{NodeSet, FxHashSet};

src/librustc/middle/region.rs

@@ -27,7 +27,7 @@ use syntax::codemap;
 use syntax::ast;
 use syntax_pos::{Span, DUMMY_SP};
 use ty::TyCtxt;
-use ty::maps::Providers;
+use ty::query::Providers;
 
 use hir;
 use hir::def_id::DefId;

src/librustc/middle/resolve_lifetime.rs

@@ -349,8 +349,8 @@ type ScopeRef<'a> = &'a Scope<'a>;
 
 const ROOT_SCOPE: ScopeRef<'static> = &Scope::Root;
 
-pub fn provide(providers: &mut ty::maps::Providers) {
-    *providers = ty::maps::Providers {
+pub fn provide(providers: &mut ty::query::Providers) {
+    *providers = ty::query::Providers {
         resolve_lifetimes,
 
         named_region_map: |tcx, id| {

src/librustc/traits/mod.rs

@@ -991,8 +991,8 @@ impl<'tcx> TraitObligation<'tcx> {
     }
 }
 
-pub fn provide(providers: &mut ty::maps::Providers) {
-    *providers = ty::maps::Providers {
+pub fn provide(providers: &mut ty::query::Providers) {
+    *providers = ty::query::Providers {
         is_object_safe: object_safety::is_object_safe_provider,
         specialization_graph_of: specialize::specialization_graph_provider,
         specializes: specialize::specializes,

src/librustc/ty/context.rs

@@ -46,7 +46,7 @@ use ty::{TyVar, TyVid, IntVar, IntVid, FloatVar, FloatVid};
 use ty::TypeVariants::*;
 use ty::GenericParamDefKind;
 use ty::layout::{LayoutDetails, TargetDataLayout};
-use ty::maps;
+use ty::query;
 use ty::steal::Steal;
 use ty::BindingMode;
 use ty::CanonicalTy;
@@ -863,11 +863,6 @@ pub struct GlobalCtxt<'tcx> {
 
     pub dep_graph: DepGraph,
 
-    /// This provides access to the incr. comp. on-disk cache for query results.
-    /// Do not access this directly. It is only meant to be used by
-    /// `DepGraph::try_mark_green()` and the query infrastructure in `ty::maps`.
-    pub(crate) on_disk_query_result_cache: maps::OnDiskCache<'tcx>,
-
     /// Common types, pre-interned for your convenience.
     pub types: CommonTypes<'tcx>,
 
@@ -886,7 +881,7 @@ pub struct GlobalCtxt<'tcx> {
     /// as well as all upstream crates. Only populated in incremental mode.
     pub def_path_hash_to_def_id: Option<FxHashMap<DefPathHash, DefId>>,
 
-    pub maps: maps::Maps<'tcx>,
+    pub(crate) queries: query::Queries<'tcx>,
 
     // Records the free variables refrenced by every closure
     // expression. Do not track deps for this, just recompute it from
@@ -1074,12 +1069,12 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     /// reference to the context, to allow formatting values that need it.
     pub fn create_and_enter<F, R>(s: &'tcx Session,
                                   cstore: &'tcx CrateStoreDyn,
-                                  local_providers: ty::maps::Providers<'tcx>,
-                                  extern_providers: ty::maps::Providers<'tcx>,
+                                  local_providers: ty::query::Providers<'tcx>,
+                                  extern_providers: ty::query::Providers<'tcx>,
                                   arenas: &'tcx AllArenas<'tcx>,
                                   resolutions: ty::Resolutions,
                                   hir: hir_map::Map<'tcx>,
-                                  on_disk_query_result_cache: maps::OnDiskCache<'tcx>,
+                                  on_disk_query_result_cache: query::OnDiskCache<'tcx>,
                                   crate_name: &str,
                                   tx: mpsc::Sender<Box<dyn Any + Send>>,
                                   output_filenames: &OutputFilenames,
@@ -1144,7 +1139,6 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
             global_arenas: &arenas.global,
             global_interners: interners,
             dep_graph: dep_graph.clone(),
-            on_disk_query_result_cache,
             types: common_types,
             trait_map,
             export_map: resolutions.export_map.into_iter().map(|(k, v)| {
@@ -1165,7 +1159,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
                     .collect(),
             hir,
             def_path_hash_to_def_id,
-            maps: maps::Maps::new(providers),
+            queries: query::Queries::new(providers, on_disk_query_result_cache),
             rcache: Lock::new(FxHashMap()),
             selection_cache: traits::SelectionCache::new(),
             evaluation_cache: traits::EvaluationCache::new(),
@@ -1343,7 +1337,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
                                            -> Result<(), E::Error>
         where E: ty::codec::TyEncoder
     {
-        self.on_disk_query_result_cache.serialize(self.global_tcx(), encoder)
+        self.queries.on_disk_cache.serialize(self.global_tcx(), encoder)
     }
 
     /// If true, we should use a naive AST walk to determine if match
@@ -1702,7 +1696,7 @@ pub mod tls {
     use std::fmt;
     use std::mem;
     use syntax_pos;
-    use ty::maps;
+    use ty::query;
     use errors::{Diagnostic, TRACK_DIAGNOSTICS};
     use rustc_data_structures::OnDrop;
     use rustc_data_structures::sync::{self, Lrc, Lock};
@@ -1726,8 +1720,8 @@ pub mod tls {
         pub tcx: TyCtxt<'a, 'gcx, 'tcx>,
 
         /// The current query job, if any. This is updated by start_job in
-        /// ty::maps::plumbing when executing a query
-        pub query: Option<Lrc<maps::QueryJob<'gcx>>>,
+        /// ty::query::plumbing when executing a query
+        pub query: Option<Lrc<query::QueryJob<'gcx>>>,
 
         /// Used to prevent layout from recursing too deeply.
         pub layout_depth: usize,
@@ -2792,7 +2786,7 @@ impl<T, R, E> InternIteratorElement<T, R> for Result<T, E> {
     }
 }
 
-pub fn provide(providers: &mut ty::maps::Providers) {
+pub fn provide(providers: &mut ty::query::Providers) {
     // FIXME(#44234) - almost all of these queries have no sub-queries and
     // therefore no actual inputs, they're just reading tables calculated in
     // resolve! Does this work? Unsure! That's what the issue is about

src/librustc/ty/erase_regions.rs

@@ -11,8 +11,8 @@
 use ty::{self, Ty, TyCtxt};
 use ty::fold::{TypeFolder, TypeFoldable};
 
-pub(super) fn provide(providers: &mut ty::maps::Providers) {
-    *providers = ty::maps::Providers {
+pub(super) fn provide(providers: &mut ty::query::Providers) {
+    *providers = ty::query::Providers {
         erase_regions_ty,
         ..*providers
     };

src/librustc/ty/layout.rs

@@ -194,8 +194,8 @@ fn layout_raw<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     })
 }
 
-pub fn provide(providers: &mut ty::maps::Providers) {
-    *providers = ty::maps::Providers {
+pub fn provide(providers: &mut ty::query::Providers) {
+    *providers = ty::query::Providers {
         layout_raw,
         ..*providers
     };
@@ -1481,7 +1481,7 @@ impl<'a, 'tcx> LayoutOf for LayoutCx<'tcx, TyCtxt<'a, 'tcx, 'tcx>> {
     }
 }
 
-impl<'a, 'tcx> LayoutOf for LayoutCx<'tcx, ty::maps::TyCtxtAt<'a, 'tcx, 'tcx>> {
+impl<'a, 'tcx> LayoutOf for LayoutCx<'tcx, ty::query::TyCtxtAt<'a, 'tcx, 'tcx>> {
     type Ty = Ty<'tcx>;
     type TyLayout = Result<TyLayout<'tcx>, LayoutError<'tcx>>;
 
@@ -1527,7 +1527,7 @@ impl TyCtxt<'a, 'tcx, '_> {
     }
 }
 
-impl ty::maps::TyCtxtAt<'a, 'tcx, '_> {
+impl ty::query::TyCtxtAt<'a, 'tcx, '_> {
     /// Computes the layout of a type. Note that this implicitly
     /// executes in "reveal all" mode.
     #[inline]

src/librustc/ty/mod.rs

@@ -85,7 +85,7 @@ pub use self::instance::{Instance, InstanceDef};
 
 pub use self::trait_def::TraitDef;
 
-pub use self::maps::queries;
+pub use self::query::queries;
 
 pub mod adjustment;
 pub mod binding;
@@ -100,8 +100,8 @@ pub mod inhabitedness;
 pub mod item_path;
 pub mod layout;
 pub mod _match;
-pub mod maps;
 pub mod outlives;
+pub mod query;
 pub mod relate;
 pub mod steal;
 pub mod subst;
@@ -2175,7 +2175,7 @@ impl<'a, 'gcx, 'tcx> AdtDef {
     /// Due to normalization being eager, this applies even if
     /// the associated type is behind a pointer, e.g. issue #31299.
     pub fn sized_constraint(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> &'tcx [Ty<'tcx>] {
-        match tcx.try_get_query::<queries::adt_sized_constraint>(DUMMY_SP, self.did) {
+        match tcx.try_adt_sized_constraint(DUMMY_SP, self.did) {
             Ok(tys) => tys,
             Err(mut bug) => {
                 debug!("adt_sized_constraint: {:?} is recursive", self);
@@ -2917,12 +2917,12 @@ fn instance_def_size_estimate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     }
 }
 
-pub fn provide(providers: &mut ty::maps::Providers) {
+pub fn provide(providers: &mut ty::query::Providers) {
     context::provide(providers);
     erase_regions::provide(providers);
     layout::provide(providers);
     util::provide(providers);
-    *providers = ty::maps::Providers {
+    *providers = ty::query::Providers {
         associated_item,
         associated_item_def_ids,
         adt_sized_constraint,

src/librustc/ty/maps/README.md renamed to src/librustc/ty/query/README.md

@@ -55,7 +55,7 @@ get to use the nice method-call-style syntax. Instead, you invoke
 using the `try_get` method, which looks roughly like this:
 
 ```rust
-use ty::maps::queries;
+use ty::query::queries;
 ...
 match queries::type_of::try_get(tcx, DUMMY_SP, self.did) {
   Ok(result) => {
@@ -207,7 +207,7 @@ by the time you read this README, but at present it looks something
 like:
 
 ```
-define_maps! { <'tcx>
+define_queries! { <'tcx>
     /// Records the type of every item.
     [] fn type_of: TypeOfItem(DefId) -> Ty<'tcx>,
 
@@ -235,7 +235,7 @@ Let's go over them one by one:
   processed.
 - **Name of query:** the name of the query method
   (`tcx.type_of(..)`). Also used as the name of a struct
-  (`ty::maps::queries::type_of`) that will be generated to represent
+  (`ty::query::queries::type_of`) that will be generated to represent
   this query.
 - **Dep-node constructor:** indicates the constructor function that
   connects this query to incremental compilation. Typically, this is a
@@ -247,7 +247,7 @@ Let's go over them one by one:
     bottom of the file. This is typically used when the query key is
     not a def-id, or just not the type that the dep-node expects.
 - **Query key type:** the type of the argument to this query.
-  This type must implement the `ty::maps::keys::Key` trait, which
+  This type must implement the `ty::query::keys::Key` trait, which
   defines (for example) how to map it to a crate, and so forth.
 - **Result type of query:** the type produced by this query. This type
   should (a) not use `RefCell` or other interior mutability and (b) be
@@ -260,14 +260,14 @@ Let's go over them one by one:
 
 So, to add a query:
 
-- Add an entry to `define_maps!` using the format above.
+- Add an entry to `define_queries!` using the format above.
 - Possibly add a corresponding entry to the dep-node macro.
 - Link the provider by modifying the appropriate `provide` method;
   or add a new one if needed and ensure that `rustc_driver` is invoking it.
 
 #### Query structs and descriptions
 
-For each kind, the `define_maps` macro will generate a "query struct"
+For each kind, the `define_queries` macro will generate a "query struct"
 named after the query. This struct is a kind of a place-holder
 describing the query. Each such struct implements the
 `self::config::QueryConfig` trait, which has associated types for the