Introduce a QueryEngine trait object.

compiler/rustc_middle/src/ty/context.rs

@@ -14,7 +14,7 @@ use crate::middle::stability;
 use crate::mir::interpret::{self, Allocation, ConstValue, Scalar};
 use crate::mir::{Body, Field, Local, Place, PlaceElem, ProjectionKind, Promoted};
 use crate::traits;
-use crate::ty::query::{self, OnDiskCache, Queries, TyCtxtAt};
+use crate::ty::query::{self, OnDiskCache, TyCtxtAt};
 use crate::ty::subst::{GenericArg, GenericArgKind, InternalSubsts, Subst, SubstsRef, UserSubsts};
 use crate::ty::TyKind::*;
 use crate::ty::{
@@ -968,7 +968,7 @@ pub struct GlobalCtxt<'tcx> {
     /// This is `None` if we are not incremental compilation mode
     pub(crate) on_disk_cache: Option<OnDiskCache<'tcx>>,
 
-    pub queries: &'tcx query::Queries<'tcx>,
+    pub queries: &'tcx dyn query::QueryEngine<'tcx>,
     pub query_caches: query::QueryCaches<'tcx>,
 
     maybe_unused_trait_imports: FxHashSet<LocalDefId>,
@@ -1115,7 +1115,7 @@ impl<'tcx> TyCtxt<'tcx> {
         definitions: &'tcx Definitions,
         dep_graph: DepGraph,
         on_disk_cache: Option<query::OnDiskCache<'tcx>>,
-        queries: &'tcx Queries<'tcx>,
+        queries: &'tcx dyn query::QueryEngine<'tcx>,
         crate_name: &str,
         output_filenames: &OutputFilenames,
     ) -> GlobalCtxt<'tcx> {

compiler/rustc_middle/src/ty/query/mod.rs

@@ -37,7 +37,7 @@ use rustc_data_structures::stable_hasher::StableVec;
 use rustc_data_structures::steal::Steal;
 use rustc_data_structures::svh::Svh;
 use rustc_data_structures::sync::Lrc;
-use rustc_errors::ErrorReported;
+use rustc_errors::{Diagnostic, ErrorReported, Handler, Level};
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, DefIdSet, LocalDefId};
@@ -122,8 +122,7 @@ impl TyCtxt<'tcx> {
     }
 
     pub fn try_mark_green(self, dep_node: &dep_graph::DepNode) -> bool {
-        let qcx = QueryCtxt { tcx: self, queries: self.queries };
-        self.dep_graph.try_mark_green(qcx, dep_node).is_some()
+        self.queries.try_mark_green(self, dep_node)
     }
 }
 
@@ -240,6 +239,40 @@ macro_rules! define_callbacks {
         impl Clone for Providers {
             fn clone(&self) -> Self { *self }
         }
+
+        pub trait QueryEngine<'tcx>: rustc_data_structures::sync::Sync {
+            #[cfg(parallel_compiler)]
+            unsafe fn deadlock(&'tcx self, tcx: TyCtxt<'tcx>, registry: &rustc_rayon_core::Registry);
+
+            fn encode_query_results(
+                &'tcx self,
+                tcx: TyCtxt<'tcx>,
+                encoder: &mut on_disk_cache::CacheEncoder<'a, 'tcx, opaque::FileEncoder>,
+                query_result_index: &mut on_disk_cache::EncodedQueryResultIndex,
+            ) -> opaque::FileEncodeResult;
+
+            fn exec_cache_promotions(&'tcx self, tcx: TyCtxt<'tcx>);
+
+            fn try_mark_green(&'tcx self, tcx: TyCtxt<'tcx>, dep_node: &dep_graph::DepNode) -> bool;
+
+            fn try_print_query_stack(
+                &'tcx self,
+                tcx: TyCtxt<'tcx>,
+                query: Option<QueryJobId<dep_graph::DepKind>>,
+                handler: &Handler,
+                num_frames: Option<usize>,
+            ) -> usize;
+
+            $($(#[$attr])*
+            fn $name(
+                &'tcx self,
+                tcx: TyCtxt<$tcx>,
+                span: Span,
+                key: query_keys::$name<$tcx>,
+                lookup: QueryLookup,
+                mode: QueryMode,
+            ) -> Option<query_stored::$name<$tcx>>;)*
+        }
     };
 }
 

compiler/rustc_middle/src/ty/query/plumbing.rs

@@ -2,8 +2,8 @@
 //! generate the actual methods on tcx which find and execute the provider,
 //! manage the caches, and so forth.
 
-use crate::dep_graph::{self, DepKind, DepNode, DepNodeExt, DepNodeIndex, SerializedDepNodeIndex};
-use crate::ty::query::{on_disk_cache, queries, Queries, Query};
+use crate::dep_graph::{DepKind, DepNode, DepNodeExt, DepNodeIndex, SerializedDepNodeIndex};
+use crate::ty::query::{on_disk_cache, queries, Query};
 use crate::ty::tls::{self, ImplicitCtxt};
 use crate::ty::{self, TyCtxt};
 use rustc_query_system::dep_graph::HasDepContext;
@@ -13,7 +13,7 @@ use rustc_query_system::query::{QueryContext, QueryDescription};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::Lock;
 use rustc_data_structures::thin_vec::ThinVec;
-use rustc_errors::{struct_span_err, Diagnostic, DiagnosticBuilder, Handler, Level};
+use rustc_errors::{struct_span_err, Diagnostic, DiagnosticBuilder};
 use rustc_serialize::opaque;
 use rustc_span::def_id::{DefId, LocalDefId};
 use rustc_span::Span;
@@ -266,49 +266,6 @@ impl<'tcx> QueryCtxt<'tcx> {
     }
 }
 
-impl<'tcx> Queries<'tcx> {
-    pub fn try_print_query_stack(
-        &'tcx self,
-        tcx: TyCtxt<'tcx>,
-        query: Option<QueryJobId<dep_graph::DepKind>>,
-        handler: &Handler,
-        num_frames: Option<usize>,
-    ) -> usize {
-        let query_map = self.try_collect_active_jobs();
-
-        let mut current_query = query;
-        let mut i = 0;
-
-        while let Some(query) = current_query {
-            if Some(i) == num_frames {
-                break;
-            }
-            let query_info = if let Some(info) = query_map.as_ref().and_then(|map| map.get(&query))
-            {
-                info
-            } else {
-                break;
-            };
-            let mut diag = Diagnostic::new(
-                Level::FailureNote,
-                &format!(
-                    "#{} [{}] {}",
-                    i,
-                    query_info.info.query.name(),
-                    query_info.info.query.describe(QueryCtxt { tcx, queries: self })
-                ),
-            );
-            diag.span = tcx.sess.source_map().guess_head_span(query_info.info.span).into();
-            handler.force_print_diagnostic(diag);
-
-            current_query = query_info.job.parent;
-            i += 1;
-        }
-
-        i
-    }
-}
-
 /// This struct stores metadata about each Query.
 ///
 /// Information is retrieved by indexing the `QUERIES` array using the integer value
@@ -689,14 +646,16 @@ macro_rules! define_queries_struct {
 
                 Some(jobs)
             }
+        }
 
+        impl QueryEngine<'tcx> for Queries<'tcx> {
             #[cfg(parallel_compiler)]
-            pub unsafe fn deadlock(&'tcx self, tcx: TyCtxt<'tcx>, registry: &rustc_rayon_core::Registry) {
+            unsafe fn deadlock(&'tcx self, tcx: TyCtxt<'tcx>, registry: &rustc_rayon_core::Registry) {
                 let tcx = QueryCtxt { tcx, queries: self };
                 rustc_query_system::query::deadlock(tcx, registry)
             }
 
-            pub(crate) fn encode_query_results(
+            fn encode_query_results(
                 &'tcx self,
                 tcx: TyCtxt<'tcx>,
                 encoder: &mut on_disk_cache::CacheEncoder<'a, 'tcx, opaque::FileEncoder>,
@@ -711,6 +670,52 @@ macro_rules! define_queries_struct {
                 tcx.dep_graph.exec_cache_promotions(tcx)
             }
 
+            fn try_mark_green(&'tcx self, tcx: TyCtxt<'tcx>, dep_node: &dep_graph::DepNode) -> bool {
+                let qcx = QueryCtxt { tcx, queries: self };
+                tcx.dep_graph.try_mark_green(qcx, dep_node).is_some()
+            }
+
+            fn try_print_query_stack(
+                &'tcx self,
+                tcx: TyCtxt<'tcx>,
+                query: Option<QueryJobId<dep_graph::DepKind>>,
+                handler: &Handler,
+                num_frames: Option<usize>,
+            ) -> usize {
+                let query_map = self.try_collect_active_jobs();
+
+                let mut current_query = query;
+                let mut i = 0;
+
+                while let Some(query) = current_query {
+                    if Some(i) == num_frames {
+                        break;
+                    }
+                    let query_info = if let Some(info) = query_map.as_ref().and_then(|map| map.get(&query))
+                    {
+                        info
+                    } else {
+                        break;
+                    };
+                    let mut diag = Diagnostic::new(
+                        Level::FailureNote,
+                        &format!(
+                            "#{} [{}] {}",
+                            i,
+                            query_info.info.query.name(),
+                            query_info.info.query.describe(QueryCtxt { tcx, queries: self })
+                        ),
+                    );
+                    diag.span = tcx.sess.source_map().guess_head_span(query_info.info.span).into();
+                    handler.force_print_diagnostic(diag);
+
+                    current_query = query_info.job.parent;
+                    i += 1;
+                }
+
+                i
+            }
+
             $($(#[$attr])*
             #[inline(always)]
             fn $name(