Revert the QueryStackFrameExtra/QueryStackDeferred split.

PR rust-lang#138672 introduced a complex and invasive split of `QueryStackFrame`
to avoid a query cycle. This commit reverts that change because there is
a much simpler change that fixes the problem, which will be in the next
commit.

Author: nnethercote

compiler/rustc_middle/src/query/mod.rs

@@ -87,7 +87,7 @@ use rustc_index::IndexVec;
 use rustc_lint_defs::LintId;
 use rustc_macros::rustc_queries;
 use rustc_query_system::ich::StableHashingContext;
-use rustc_query_system::query::{QueryMode, QueryStackDeferred, QueryState};
+use rustc_query_system::query::{QueryMode, QueryState};
 use rustc_session::Limits;
 use rustc_session::config::{EntryFnType, OptLevel, OutputFilenames, SymbolManglingVersion};
 use rustc_session::cstore::{

compiler/rustc_middle/src/query/plumbing.rs

@@ -431,7 +431,7 @@ macro_rules! define_callbacks {
         #[derive(Default)]
         pub struct QueryStates<'tcx> {
             $(
-                pub $name: QueryState<$($K)*, QueryStackDeferred<'tcx>>,
+                pub $name: QueryState<$($K)*>,
             )*
         }
 

compiler/rustc_middle/src/values.rs

@@ -88,7 +88,7 @@ impl<'tcx> Value<TyCtxt<'tcx>> for Representability {
             if info.query.dep_kind == dep_kinds::representability
                 && let Some(field_id) = info.query.def_id
                 && let Some(field_id) = field_id.as_local()
-                && let Some(DefKind::Field) = info.query.info.def_kind
+                && let Some(DefKind::Field) = info.query.def_kind
             {
                 let parent_id = tcx.parent(field_id.to_def_id());
                 let item_id = match tcx.def_kind(parent_id) {
@@ -224,7 +224,7 @@ impl<'tcx, T> Value<TyCtxt<'tcx>> for Result<T, &'_ ty::layout::LayoutError<'_>>
                             continue;
                         };
                         let frame_span =
-                            frame.query.info.default_span(cycle[(i + 1) % cycle.len()].span);
+                            frame.query.default_span(cycle[(i + 1) % cycle.len()].span);
                         if frame_span.is_dummy() {
                             continue;
                         }

compiler/rustc_query_impl/src/lib.rs

@@ -21,8 +21,8 @@ use rustc_middle::ty::TyCtxt;
 use rustc_query_system::dep_graph::SerializedDepNodeIndex;
 use rustc_query_system::ich::StableHashingContext;
 use rustc_query_system::query::{
-    CycleError, HashResult, QueryCache, QueryConfig, QueryMap, QueryMode, QueryStackDeferred,
-    QueryState, get_query_incr, get_query_non_incr,
+    CycleError, HashResult, QueryCache, QueryConfig, QueryMap, QueryMode, QueryState,
+    get_query_incr, get_query_non_incr,
 };
 use rustc_query_system::{HandleCycleError, Value};
 use rustc_span::{ErrorGuaranteed, Span};
@@ -79,10 +79,7 @@ where
     }
 
     #[inline(always)]
-    fn query_state<'a>(
-        self,
-        qcx: QueryCtxt<'tcx>,
-    ) -> &'a QueryState<Self::Key, QueryStackDeferred<'tcx>>
+    fn query_state<'a>(self, qcx: QueryCtxt<'tcx>) -> &'a QueryState<Self::Key>
     where
         QueryCtxt<'tcx>: 'a,
     {
@@ -91,7 +88,7 @@ where
         unsafe {
             &*(&qcx.tcx.query_system.states as *const QueryStates<'tcx>)
                 .byte_add(self.dynamic.query_state)
-                .cast::<QueryState<Self::Key, QueryStackDeferred<'tcx>>>()
+                .cast::<QueryState<Self::Key>>()
         }
     }
 

compiler/rustc_query_impl/src/plumbing.rs

@@ -6,7 +6,6 @@ use std::num::NonZero;
 
 use rustc_data_structures::jobserver::Proxy;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
-use rustc_data_structures::sync::{DynSend, DynSync};
 use rustc_data_structures::unord::UnordMap;
 use rustc_hashes::Hash64;
 use rustc_hir::limit::Limit;
@@ -27,8 +26,8 @@ use rustc_middle::ty::{self, TyCtxt};
 use rustc_query_system::dep_graph::{DepNodeParams, HasDepContext};
 use rustc_query_system::ich::StableHashingContext;
 use rustc_query_system::query::{
-    QueryCache, QueryConfig, QueryContext, QueryJobId, QueryMap, QuerySideEffect,
-    QueryStackDeferred, QueryStackFrame, QueryStackFrameExtra, force_query,
+    QueryCache, QueryConfig, QueryContext, QueryJobId, QueryMap, QuerySideEffect, QueryStackFrame,
+    force_query,
 };
 use rustc_query_system::{QueryOverflow, QueryOverflowNote};
 use rustc_serialize::{Decodable, Encodable};
@@ -67,9 +66,7 @@ impl<'tcx> HasDepContext for QueryCtxt<'tcx> {
     }
 }
 
-impl<'tcx> QueryContext for QueryCtxt<'tcx> {
-    type QueryInfo = QueryStackDeferred<'tcx>;
-
+impl QueryContext for QueryCtxt<'_> {
     #[inline]
     fn jobserver_proxy(&self) -> &Proxy {
         &*self.jobserver_proxy
@@ -98,10 +95,7 @@ impl<'tcx> QueryContext for QueryCtxt<'tcx> {
     /// Prefer passing `false` to `require_complete` to avoid potential deadlocks,
     /// especially when called from within a deadlock handler, unless a
     /// complete map is needed and no deadlock is possible at this call site.
-    fn collect_active_jobs(
-        self,
-        require_complete: bool,
-    ) -> Result<QueryMap<QueryStackDeferred<'tcx>>, QueryMap<QueryStackDeferred<'tcx>>> {
+    fn collect_active_jobs(self, require_complete: bool) -> Result<QueryMap, QueryMap> {
         let mut jobs = QueryMap::default();
         let mut complete = true;
 
@@ -114,13 +108,6 @@ impl<'tcx> QueryContext for QueryCtxt<'tcx> {
         if complete { Ok(jobs) } else { Err(jobs) }
     }
 
-    fn lift_query_info(
-        self,
-        info: &QueryStackDeferred<'tcx>,
-    ) -> rustc_query_system::query::QueryStackFrameExtra {
-        info.extract()
-    }
-
     // Interactions with on_disk_cache
     fn load_side_effect(
         self,
@@ -181,10 +168,7 @@ impl<'tcx> QueryContext for QueryCtxt<'tcx> {
 
         self.sess.dcx().emit_fatal(QueryOverflow {
             span: info.job.span,
-            note: QueryOverflowNote {
-                desc: self.lift_query_info(&info.query.info).description,
-                depth,
-            },
+            note: QueryOverflowNote { desc: info.query.description, depth },
             suggested_limit,
             crate_name: self.crate_name(LOCAL_CRATE),
         });
@@ -321,17 +305,16 @@ macro_rules! should_ever_cache_on_disk {
     };
 }
 
-fn create_query_frame_extra<'tcx, K: Key + Copy + 'tcx>(
-    (tcx, key, kind, name, do_describe): (
-        TyCtxt<'tcx>,
-        K,
-        DepKind,
-        &'static str,
-        fn(TyCtxt<'tcx>, K) -> String,
-    ),
-) -> QueryStackFrameExtra {
-    let def_id = key.key_as_def_id();
-
+pub(crate) fn create_query_frame<
+    'tcx,
+    K: Copy + Key + for<'a> HashStable<StableHashingContext<'a>>,
+>(
+    tcx: TyCtxt<'tcx>,
+    do_describe: fn(TyCtxt<'tcx>, K) -> String,
+    key: K,
+    kind: DepKind,
+    name: &'static str,
+) -> QueryStackFrame {
     // If reduced queries are requested, we may be printing a query stack due
     // to a panic. Avoid using `default_span` and `def_kind` in that case.
     let reduce_queries = with_reduced_queries();
@@ -343,6 +326,7 @@ fn create_query_frame_extra<'tcx, K: Key + Copy + 'tcx>(
     } else {
         description
     };
+
     let span = if kind == dep_graph::dep_kinds::def_span || reduce_queries {
         // The `def_span` query is used to calculate `default_span`,
         // so exit to avoid infinite recursion.
@@ -351,41 +335,25 @@ fn create_query_frame_extra<'tcx, K: Key + Copy + 'tcx>(
         Some(key.default_span(tcx))
     };
 
+    let def_id = key.key_as_def_id();
+
     let def_kind = if kind == dep_graph::dep_kinds::def_kind || reduce_queries {
         // Try to avoid infinite recursion.
         None
     } else {
         def_id.and_then(|def_id| def_id.as_local()).map(|def_id| tcx.def_kind(def_id))
     };
-    QueryStackFrameExtra::new(description, span, def_kind)
-}
-
-pub(crate) fn create_query_frame<
-    'tcx,
-    K: Copy + DynSend + DynSync + Key + for<'a> HashStable<StableHashingContext<'a>> + 'tcx,
->(
-    tcx: TyCtxt<'tcx>,
-    do_describe: fn(TyCtxt<'tcx>, K) -> String,
-    key: K,
-    kind: DepKind,
-    name: &'static str,
-) -> QueryStackFrame<QueryStackDeferred<'tcx>> {
-    let def_id = key.key_as_def_id();
 
-    let hash = || {
-        tcx.with_stable_hashing_context(|mut hcx| {
-            let mut hasher = StableHasher::new();
-            kind.as_usize().hash_stable(&mut hcx, &mut hasher);
-            key.hash_stable(&mut hcx, &mut hasher);
-            hasher.finish::<Hash64>()
-        })
-    };
     let def_id_for_ty_in_cycle = key.def_id_for_ty_in_cycle();
 
-    let info =
-        QueryStackDeferred::new((tcx, key, kind, name, do_describe), create_query_frame_extra);
+    let hash = tcx.with_stable_hashing_context(|mut hcx| {
+        let mut hasher = StableHasher::new();
+        kind.as_usize().hash_stable(&mut hcx, &mut hasher);
+        key.hash_stable(&mut hcx, &mut hasher);
+        hasher.finish::<Hash64>()
+    });
 
-    QueryStackFrame::new(info, kind, hash, def_id, def_id_for_ty_in_cycle)
+    QueryStackFrame::new(description, span, def_id, def_kind, kind, def_id_for_ty_in_cycle, hash)
 }
 
 pub(crate) fn encode_query_results<'a, 'tcx, Q>(
@@ -737,7 +705,7 @@ macro_rules! define_queries {
 
             pub(crate) fn collect_active_jobs<'tcx>(
                 tcx: TyCtxt<'tcx>,
-                qmap: &mut QueryMap<QueryStackDeferred<'tcx>>,
+                qmap: &mut QueryMap,
                 require_complete: bool,
             ) -> Option<()> {
                 let make_query = |tcx, key| {
@@ -821,7 +789,7 @@ macro_rules! define_queries {
         // These arrays are used for iteration and can't be indexed by `DepKind`.
 
         const COLLECT_ACTIVE_JOBS: &[
-            for<'tcx> fn(TyCtxt<'tcx>, &mut QueryMap<QueryStackDeferred<'tcx>>, bool) -> Option<()>
+            for<'tcx> fn(TyCtxt<'tcx>, &mut QueryMap, bool) -> Option<()>
         ] =
             &[$(query_impl::$name::collect_active_jobs),*];
 

compiler/rustc_query_system/src/query/config.rs

@@ -6,7 +6,6 @@ use std::hash::Hash;
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_span::ErrorGuaranteed;
 
-use super::QueryStackFrameExtra;
 use crate::dep_graph::{DepKind, DepNode, DepNodeParams, SerializedDepNodeIndex};
 use crate::error::HandleCycleError;
 use crate::ich::StableHashingContext;
@@ -28,7 +27,7 @@ pub trait QueryConfig<Qcx: QueryContext>: Copy {
     fn format_value(self) -> fn(&Self::Value) -> String;
 
     // Don't use this method to access query results, instead use the methods on TyCtxt
-    fn query_state<'a>(self, tcx: Qcx) -> &'a QueryState<Self::Key, Qcx::QueryInfo>
+    fn query_state<'a>(self, tcx: Qcx) -> &'a QueryState<Self::Key>
     where
         Qcx: 'a;
 
@@ -58,7 +57,7 @@ pub trait QueryConfig<Qcx: QueryContext>: Copy {
     fn value_from_cycle_error(
         self,
         tcx: Qcx::DepContext,
-        cycle_error: &CycleError<QueryStackFrameExtra>,
+        cycle_error: &CycleError,
         guar: ErrorGuaranteed,
     ) -> Self::Value;