Rollup merge of rust-lang#40540 - cramertj:check-bodies-as-query, r=nikomatsakis

On-demandify the typechecking of item bodies

r? @nikomatsakis

Author: alexcrichton

src/librustc/ty/maps.rs

@@ -189,6 +189,13 @@ impl<'tcx> QueryDescription for queries::mir_shims<'tcx> {
     }
 }
 
+impl<'tcx> QueryDescription for queries::typeck_item_bodies<'tcx> {
+    fn describe(_: TyCtxt, _: CrateNum) -> String {
+        format!("type-checking all item bodies")
+    }
+}
+
+
 macro_rules! define_maps {
     (<$tcx:tt>
      $($(#[$attr:meta])*
@@ -396,6 +403,8 @@ define_maps! { <'tcx>
     pub custom_coerce_unsized_kind: ItemSignature(DefId)
         -> ty::adjustment::CustomCoerceUnsized,
 
+    pub typeck_item_bodies: typeck_item_bodies_dep_node(CrateNum) -> (),
+
     pub typeck_tables: TypeckTables(DefId) -> &'tcx ty::TypeckTables<'tcx>,
 
     pub coherent_trait: coherent_trait_dep_node((CrateNum, DefId)) -> (),
@@ -420,3 +429,7 @@ fn coherent_inherent_impls_dep_node(_: CrateNum) -> DepNode<DefId> {
 fn mir_shim(instance: ty::InstanceDef) -> DepNode<DefId> {
     instance.dep_node()
 }
+
+fn typeck_item_bodies_dep_node(_: CrateNum) -> DepNode<DefId> {
+    DepNode::TypeckBodiesKrate
+}

src/librustc_typeck/check/mod.rs

@@ -84,7 +84,7 @@ use astconv::AstConv;
 use dep_graph::DepNode;
 use fmt_macros::{Parser, Piece, Position};
 use hir::def::{Def, CtorKind};
-use hir::def_id::{DefId, LOCAL_CRATE};
+use hir::def_id::{CrateNum, DefId, LOCAL_CRATE};
 use rustc::infer::{self, InferCtxt, InferOk, RegionVariableOrigin, TypeTrace};
 use rustc::infer::type_variable::{self, TypeVariableOrigin};
 use rustc::ty::subst::{Kind, Subst, Substs};
@@ -542,18 +542,26 @@ pub fn check_item_types<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) -> CompileResult
 
 pub fn check_item_bodies<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) -> CompileResult {
     return tcx.sess.track_errors(|| {
+        // FIXME(cramertj): This `with_task` should be removed once there is a task for
+        // typeck or for the compilation as a whole
         tcx.dep_graph.with_task(DepNode::TypeckBodiesKrate, tcx, (), check_item_bodies_task);
     });
 
     fn check_item_bodies_task<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, (): ()) {
-        tcx.visit_all_bodies_in_krate(|body_owner_def_id, _body_id| {
-            tcx.item_tables(body_owner_def_id);
-        });
+        ty::queries::typeck_item_bodies::get(tcx, DUMMY_SP, LOCAL_CRATE)
     }
 }
 
+fn typeck_item_bodies<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, crate_num: CrateNum) {
+    debug_assert!(crate_num == LOCAL_CRATE);
+    tcx.visit_all_bodies_in_krate(|body_owner_def_id, _body_id| {
+        tcx.item_tables(body_owner_def_id);
+    });
+}
+
 pub fn provide(providers: &mut Providers) {
     *providers = Providers {
+        typeck_item_bodies,
         typeck_tables,
         closure_type,
         closure_kind,