Merge two query callbacks arrays.

12 files changed, 180 insertions, 247 deletions

diff --git a/compiler/rustc_incremental/src/assert_dep_graph.rs b/compiler/rustc_incremental/src/assert_dep_graph.rs
index d42e2f7a99c..571337a8dcb 100644
--- a/compiler/rustc_incremental/src/assert_dep_graph.rs
+++ b/compiler/rustc_incremental/src/assert_dep_graph.rs
@@ -126,30 +126,36 @@ impl IfThisChanged<'tcx> {
             if attr.has_name(sym::rustc_if_this_changed) {
                 let dep_node_interned = self.argument(attr);
                 let dep_node = match dep_node_interned {
-                    None => DepNode::from_def_path_hash(def_path_hash, DepKind::hir_owner),
-                    Some(n) => match DepNode::from_label_string(&n.as_str(), def_path_hash) {
-                        Ok(n) => n,
-                        Err(()) => {
-                            self.tcx.sess.span_fatal(
-                                attr.span,
-                                &format!("unrecognized DepNode variant {:?}", n),
-                            );
+                    None => {
+                        DepNode::from_def_path_hash(self.tcx, def_path_hash, DepKind::hir_owner)
+                    }
+                    Some(n) => {
+                        match DepNode::from_label_string(self.tcx, &n.as_str(), def_path_hash) {
+                            Ok(n) => n,
+                            Err(()) => {
+                                self.tcx.sess.span_fatal(
+                                    attr.span,
+                                    &format!("unrecognized DepNode variant {:?}", n),
+                                );
+                            }
                         }
-                    },
+                    }
                 };
                 self.if_this_changed.push((attr.span, def_id.to_def_id(), dep_node));
             } else if attr.has_name(sym::rustc_then_this_would_need) {
                 let dep_node_interned = self.argument(attr);
                 let dep_node = match dep_node_interned {
-                    Some(n) => match DepNode::from_label_string(&n.as_str(), def_path_hash) {
-                        Ok(n) => n,
-                        Err(()) => {
-                            self.tcx.sess.span_fatal(
-                                attr.span,
-                                &format!("unrecognized DepNode variant {:?}", n),
-                            );
+                    Some(n) => {
+                        match DepNode::from_label_string(self.tcx, &n.as_str(), def_path_hash) {
+                            Ok(n) => n,
+                            Err(()) => {
+                                self.tcx.sess.span_fatal(
+                                    attr.span,
+                                    &format!("unrecognized DepNode variant {:?}", n),
+                                );
+                            }
                         }
-                    },
+                    }
                     None => {
                         self.tcx.sess.span_fatal(attr.span, "missing DepNode variant");
                     }
diff --git a/compiler/rustc_incremental/src/persist/dirty_clean.rs b/compiler/rustc_incremental/src/persist/dirty_clean.rs
index 55286384de3..b2eaf61b7d1 100644
--- a/compiler/rustc_incremental/src/persist/dirty_clean.rs
+++ b/compiler/rustc_incremental/src/persist/dirty_clean.rs
@@ -15,7 +15,7 @@
 use rustc_ast::{self as ast, Attribute, NestedMetaItem};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
-use rustc_hir::def_id::{DefId, LocalDefId};
+use rustc_hir::def_id::LocalDefId;
 use rustc_hir::intravisit;
 use rustc_hir::itemlikevisit::ItemLikeVisitor;
 use rustc_hir::Node as HirNode;
@@ -302,18 +302,6 @@ impl DirtyCleanVisitor<'tcx> {
         out
     }
 
-    fn dep_nodes<'l>(
-        &self,
-        labels: &'l Labels,
-        def_id: DefId,
-    ) -> impl Iterator<Item = DepNode> + 'l {
-        let def_path_hash = self.tcx.def_path_hash(def_id);
-        labels.iter().map(move |label| match DepNode::from_label_string(label, def_path_hash) {
-            Ok(dep_node) => dep_node,
-            Err(()) => unreachable!("label: {}", label),
-        })
-    }
-
     fn dep_node_str(&self, dep_node: &DepNode) -> String {
         if let Some(def_id) = dep_node.extract_def_id(self.tcx) {
             format!("{:?}({})", dep_node.kind, self.tcx.def_path_str(def_id))
@@ -345,16 +333,19 @@ impl DirtyCleanVisitor<'tcx> {
     }
 
     fn check_item(&mut self, item_id: LocalDefId, item_span: Span) {
+        let def_path_hash = self.tcx.def_path_hash(item_id.to_def_id());
         for attr in self.tcx.get_attrs(item_id.to_def_id()).iter() {
             let assertion = match self.assertion_maybe(item_id, attr) {
                 Some(a) => a,
                 None => continue,
             };
             self.checked_attrs.insert(attr.id);
-            for dep_node in self.dep_nodes(&assertion.clean, item_id.to_def_id()) {
+            for label in assertion.clean {
+                let dep_node = DepNode::from_label_string(self.tcx, &label, def_path_hash).unwrap();
                 self.assert_clean(item_span, dep_node);
             }
-            for dep_node in self.dep_nodes(&assertion.dirty, item_id.to_def_id()) {
+            for label in assertion.dirty {
+                let dep_node = DepNode::from_label_string(self.tcx, &label, def_path_hash).unwrap();
                 self.assert_dirty(item_span, dep_node);
             }
         }
diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs
index bcfa0ef3520..8bd6ed98973 100644
--- a/compiler/rustc_interface/src/passes.rs
+++ b/compiler/rustc_interface/src/passes.rs
@@ -838,6 +838,7 @@ pub fn create_global_ctxt<'tcx>(
                 dep_graph,
                 queries.on_disk_cache.as_ref().map(OnDiskCache::as_dyn),
                 queries.as_dyn(),
+                &rustc_query_impl::QUERY_CALLBACKS,
                 crate_name,
                 outputs,
             )
diff --git a/compiler/rustc_middle/src/dep_graph/dep_node.rs b/compiler/rustc_middle/src/dep_graph/dep_node.rs
index 09cd318bb78..ee0b4ec7a60 100644
--- a/compiler/rustc_middle/src/dep_graph/dep_node.rs
+++ b/compiler/rustc_middle/src/dep_graph/dep_node.rs
@@ -78,32 +78,70 @@ pub struct DepKindStruct {
     /// Anonymous queries cannot be replayed from one compiler invocation to the next.
     /// When their result is needed, it is recomputed. They are useful for fine-grained
     /// dependency tracking, and caching within one compiler invocation.
-    pub(super) is_anon: bool,
+    pub is_anon: bool,
 
     /// Eval-always queries do not track their dependencies, and are always recomputed, even if
     /// their inputs have not changed since the last compiler invocation. The result is still
     /// cached within one compiler invocation.
-    pub(super) is_eval_always: bool,
+    pub is_eval_always: bool,
 
     /// Whether the query key can be recovered from the hashed fingerprint.
     /// See [DepNodeParams] trait for the behaviour of each key type.
-    // FIXME: Make this a simple boolean once DepNodeParams::fingerprint_style
-    // can be made a specialized associated const.
-    fingerprint_style: fn() -> FingerprintStyle,
-}
-
-impl std::ops::Deref for DepKind {
-    type Target = DepKindStruct;
-    fn deref(&self) -> &DepKindStruct {
-        &DEP_KINDS[*self as usize]
-    }
+    pub fingerprint_style: fn() -> FingerprintStyle,
+
+    /// The red/green evaluation system will try to mark a specific DepNode in the
+    /// dependency graph as green by recursively trying to mark the dependencies of
+    /// that `DepNode` as green. While doing so, it will sometimes encounter a `DepNode`
+    /// where we don't know if it is red or green and we therefore actually have
+    /// to recompute its value in order to find out. Since the only piece of
+    /// information that we have at that point is the `DepNode` we are trying to
+    /// re-evaluate, we need some way to re-run a query from just that. This is what
+    /// `force_from_dep_node()` implements.
+    ///
+    /// In the general case, a `DepNode` consists of a `DepKind` and an opaque
+    /// GUID/fingerprint that will uniquely identify the node. This GUID/fingerprint
+    /// is usually constructed by computing a stable hash of the query-key that the
+    /// `DepNode` corresponds to. Consequently, it is not in general possible to go
+    /// back from hash to query-key (since hash functions are not reversible). For
+    /// this reason `force_from_dep_node()` is expected to fail from time to time
+    /// because we just cannot find out, from the `DepNode` alone, what the
+    /// corresponding query-key is and therefore cannot re-run the query.
+    ///
+    /// The system deals with this case letting `try_mark_green` fail which forces
+    /// the root query to be re-evaluated.
+    ///
+    /// Now, if `force_from_dep_node()` would always fail, it would be pretty useless.
+    /// Fortunately, we can use some contextual information that will allow us to
+    /// reconstruct query-keys for certain kinds of `DepNode`s. In particular, we
+    /// enforce by construction that the GUID/fingerprint of certain `DepNode`s is a
+    /// valid `DefPathHash`. Since we also always build a huge table that maps every
+    /// `DefPathHash` in the current codebase to the corresponding `DefId`, we have
+    /// everything we need to re-run the query.
+    ///
+    /// Take the `mir_promoted` query as an example. Like many other queries, it
+    /// just has a single parameter: the `DefId` of the item it will compute the
+    /// validated MIR for. Now, when we call `force_from_dep_node()` on a `DepNode`
+    /// with kind `MirValidated`, we know that the GUID/fingerprint of the `DepNode`
+    /// is actually a `DefPathHash`, and can therefore just look up the corresponding
+    /// `DefId` in `tcx.def_path_hash_to_def_id`.
+    ///
+    /// When you implement a new query, it will likely have a corresponding new
+    /// `DepKind`, and you'll have to support it here in `force_from_dep_node()`. As
+    /// a rule of thumb, if your query takes a `DefId` or `LocalDefId` as sole parameter,
+    /// then `force_from_dep_node()` should not fail for it. Otherwise, you can just
+    /// add it to the "We don't have enough information to reconstruct..." group in
+    /// the match below.
+    pub force_from_dep_node: fn(tcx: TyCtxt<'_>, dep_node: &DepNode) -> bool,
+
+    /// Invoke a query to put the on-disk cached value in memory.
+    pub try_load_from_on_disk_cache: fn(TyCtxt<'_>, &DepNode),
 }
 
 impl DepKind {
     #[inline(always)]
-    pub fn fingerprint_style(&self) -> FingerprintStyle {
+    pub fn fingerprint_style(self, tcx: TyCtxt<'_>) -> FingerprintStyle {
         // Only fetch the DepKindStruct once.
-        let data: &DepKindStruct = &**self;
+        let data = tcx.query_kind(self);
         if data.is_anon {
             return FingerprintStyle::Opaque;
         }
@@ -112,94 +150,6 @@ impl DepKind {
     }
 }
 
-macro_rules! is_anon_attr {
-    (anon) => {
-        true
-    };
-    ($attr:ident) => {
-        false
-    };
-}
-
-macro_rules! is_eval_always_attr {
-    (eval_always) => {
-        true
-    };
-    ($attr:ident) => {
-        false
-    };
-}
-
-macro_rules! contains_anon_attr {
-    ($(($attr:ident $($attr_args:tt)* )),*) => ({$(is_anon_attr!($attr) | )* false});
-}
-
-macro_rules! contains_eval_always_attr {
-    ($(($attr:ident $($attr_args:tt)* )),*) => ({$(is_eval_always_attr!($attr) | )* false});
-}
-
-#[allow(non_upper_case_globals)]
-pub mod dep_kind {
-    use super::*;
-    use crate::ty::query::query_keys;
-    use rustc_query_system::dep_graph::FingerprintStyle;
-
-    // We use this for most things when incr. comp. is turned off.
-    pub const Null: DepKindStruct = DepKindStruct {
-        is_anon: false,
-        is_eval_always: false,
-
-        fingerprint_style: || FingerprintStyle::Unit,
-    };
-
-    pub const TraitSelect: DepKindStruct = DepKindStruct {
-        is_anon: true,
-        is_eval_always: false,
-
-        fingerprint_style: || FingerprintStyle::Unit,
-    };
-
-    pub const CompileCodegenUnit: DepKindStruct = DepKindStruct {
-        is_anon: false,
-        is_eval_always: false,
-
-        fingerprint_style: || FingerprintStyle::Opaque,
-    };
-
-    pub const CompileMonoItem: DepKindStruct = DepKindStruct {
-        is_anon: false,
-        is_eval_always: false,
-
-        fingerprint_style: || FingerprintStyle::Opaque,
-    };
-
-    macro_rules! define_query_dep_kinds {
-        ($(
-            [$($attrs:tt)*]
-            $variant:ident $(( $tuple_arg_ty:ty $(,)? ))*
-        ,)*) => (
-            $(pub const $variant: DepKindStruct = {
-                const is_anon: bool = contains_anon_attr!($($attrs)*);
-                const is_eval_always: bool = contains_eval_always_attr!($($attrs)*);
-
-                #[inline(always)]
-                fn fingerprint_style() -> rustc_query_system::dep_graph::FingerprintStyle {
-                    <query_keys::$variant<'_> as DepNodeParams<TyCtxt<'_>>>
-                        ::fingerprint_style()
-                }
-
-                DepKindStruct {
-                    is_anon,
-                    is_eval_always,
-                    fingerprint_style,
-                }
-            };)*
-        );
-    }
-
-    rustc_dep_node_append!([define_query_dep_kinds!][]);
-}
-
 macro_rules! define_dep_nodes {
     (<$tcx:tt>
     $(
@@ -212,9 +162,7 @@ macro_rules! define_dep_nodes {
             ($mod:ident) => {[ $(($mod::$variant),)* ]};
         }
 
-        static DEP_KINDS: &[DepKindStruct] = &make_dep_kind_array!(dep_kind);
-
-        /// This enum serves as an index into the `DEP_KINDS` array.
+        /// This enum serves as an index into arrays built by `make_dep_kind_array`.
         #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Encodable, Decodable)]
         #[allow(non_camel_case_types)]
         pub enum DepKind {
@@ -280,7 +228,7 @@ pub trait DepNodeExt: Sized {
     /// Construct a DepNode from the given DepKind and DefPathHash. This
     /// method will assert that the given DepKind actually requires a
     /// single DefId/DefPathHash parameter.
-    fn from_def_path_hash(def_path_hash: DefPathHash, kind: DepKind) -> Self;
+    fn from_def_path_hash(tcx: TyCtxt<'_>, def_path_hash: DefPathHash, kind: DepKind) -> Self;
 
     /// Extracts the DefId corresponding to this DepNode. This will work
     /// if two conditions are met:
@@ -295,7 +243,11 @@ pub trait DepNodeExt: Sized {
     fn extract_def_id(&self, tcx: TyCtxt<'_>) -> Option<DefId>;
 
     /// Used in testing
-    fn from_label_string(label: &str, def_path_hash: DefPathHash) -> Result<Self, ()>;
+    fn from_label_string(
+        tcx: TyCtxt<'_>,
+        label: &str,
+        def_path_hash: DefPathHash,
+    ) -> Result<Self, ()>;
 
     /// Used in testing
     fn has_label_string(label: &str) -> bool;
@@ -305,8 +257,8 @@ impl DepNodeExt for DepNode {
     /// Construct a DepNode from the given DepKind and DefPathHash. This
     /// method will assert that the given DepKind actually requires a
     /// single DefId/DefPathHash parameter.
-    fn from_def_path_hash(def_path_hash: DefPathHash, kind: DepKind) -> DepNode {
-        debug_assert!(kind.fingerprint_style() == FingerprintStyle::DefPathHash);
+    fn from_def_path_hash(tcx: TyCtxt<'_>, def_path_hash: DefPathHash, kind: DepKind) -> DepNode {
+        debug_assert!(kind.fingerprint_style(tcx) == FingerprintStyle::DefPathHash);
         DepNode { kind, hash: def_path_hash.0.into() }
     }
 
@@ -321,7 +273,7 @@ impl DepNodeExt for DepNode {
     /// refers to something from the previous compilation session that
     /// has been removed.
     fn extract_def_id(&self, tcx: TyCtxt<'tcx>) -> Option<DefId> {
-        if self.kind.fingerprint_style() == FingerprintStyle::DefPathHash {
+        if self.kind.fingerprint_style(tcx) == FingerprintStyle::DefPathHash {
             Some(tcx.def_path_hash_to_def_id(DefPathHash(self.hash.into())))
         } else {
             None
@@ -329,13 +281,19 @@ impl DepNodeExt for DepNode {
     }
 
     /// Used in testing
-    fn from_label_string(label: &str, def_path_hash: DefPathHash) -> Result<DepNode, ()> {
+    fn from_label_string(
+        tcx: TyCtxt<'_>,
+        label: &str,
+        def_path_hash: DefPathHash,
+    ) -> Result<DepNode, ()> {
         let kind = dep_kind_from_label_string(label)?;
 
-        match kind.fingerprint_style() {
+        match kind.fingerprint_style(tcx) {
             FingerprintStyle::Opaque => Err(()),
-            FingerprintStyle::Unit => Ok(DepNode::new_no_params(kind)),
-            FingerprintStyle::DefPathHash => Ok(DepNode::from_def_path_hash(def_path_hash, kind)),
+            FingerprintStyle::Unit => Ok(DepNode::new_no_params(tcx, kind)),
+            FingerprintStyle::DefPathHash => {
+                Ok(DepNode::from_def_path_hash(tcx, def_path_hash, kind))
+            }
         }
     }
 
diff --git a/compiler/rustc_middle/src/dep_graph/mod.rs b/compiler/rustc_middle/src/dep_graph/mod.rs
index 2e219b1dde9..7ace3a10158 100644
--- a/compiler/rustc_middle/src/dep_graph/mod.rs
+++ b/compiler/rustc_middle/src/dep_graph/mod.rs
@@ -12,7 +12,7 @@ pub use rustc_query_system::dep_graph::{
     SerializedDepNodeIndex, WorkProduct, WorkProductId,
 };
 
-pub use dep_node::{label_strs, DepKind, DepNode, DepNodeExt};
+pub use dep_node::{label_strs, DepKind, DepKindStruct, DepNode, DepNodeExt};
 crate use dep_node::{make_compile_codegen_unit, make_compile_mono_item};
 
 pub type DepGraph = rustc_query_system::dep_graph::DepGraph<DepKind>;
@@ -24,16 +24,6 @@ pub type EdgeFilter = rustc_query_system::dep_graph::debug::EdgeFilter<DepKind>;
 impl rustc_query_system::dep_graph::DepKind for DepKind {
     const NULL: Self = DepKind::Null;
 
-    #[inline(always)]
-    fn fingerprint_style(&self) -> rustc_query_system::dep_graph::FingerprintStyle {
-        DepKind::fingerprint_style(self)
-    }
-
-    #[inline(always)]
-    fn is_eval_always(&self) -> bool {
-        self.is_eval_always
-    }
-
     fn debug_node(node: &DepNode, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(f, "{:?}(", node.kind)?;
 
@@ -99,4 +89,14 @@ impl<'tcx> DepContext for TyCtxt<'tcx> {
     fn sess(&self) -> &Session {
         self.sess
     }
+
+    #[inline(always)]
+    fn fingerprint_style(&self, kind: DepKind) -> rustc_query_system::dep_graph::FingerprintStyle {
+        kind.fingerprint_style(*self)
+    }
+
+    #[inline(always)]
+    fn is_eval_always(&self, kind: DepKind) -> bool {
+        self.query_kind(kind).is_eval_always
+    }
 }
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 1244f8372a1..b00a2c65575 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -1,7 +1,7 @@
 //! Type context book-keeping.
 
 use crate::arena::Arena;
-use crate::dep_graph::DepGraph;
+use crate::dep_graph::{DepGraph, DepKind, DepKindStruct};
 use crate::hir::place::Place as HirPlace;
 use crate::infer::canonical::{Canonical, CanonicalVarInfo, CanonicalVarInfos};
 use crate::lint::{struct_lint_level, LintDiagnosticBuilder, LintLevelSource};
@@ -1011,6 +1011,7 @@ pub struct GlobalCtxt<'tcx> {
 
     pub queries: &'tcx dyn query::QueryEngine<'tcx>,
     pub query_caches: query::QueryCaches<'tcx>,
+    query_kinds: &'tcx [DepKindStruct],
 
     // Internal caches for metadata decoding. No need to track deps on this.
     pub ty_rcache: Lock<FxHashMap<ty::CReaderCacheKey, Ty<'tcx>>>,
@@ -1144,6 +1145,7 @@ impl<'tcx> TyCtxt<'tcx> {
         dep_graph: DepGraph,
         on_disk_cache: Option<&'tcx dyn OnDiskCache<'tcx>>,
         queries: &'tcx dyn query::QueryEngine<'tcx>,
+        query_kinds: &'tcx [DepKindStruct],
         crate_name: &str,
         output_filenames: OutputFilenames,
     ) -> GlobalCtxt<'tcx> {
@@ -1170,6 +1172,7 @@ impl<'tcx> TyCtxt<'tcx> {
             on_disk_cache,
             queries,
             query_caches: query::QueryCaches::default(),
+            query_kinds,
             ty_rcache: Default::default(),
             pred_rcache: Default::default(),
             selection_cache: Default::default(),
@@ -1183,6 +1186,10 @@ impl<'tcx> TyCtxt<'tcx> {
         }
     }
 
+    pub fn query_kind(self, k: DepKind) -> &'tcx DepKindStruct {
+        &self.query_kinds[k as usize]
+    }
+
     /// Constructs a `TyKind::Error` type and registers a `delay_span_bug` to ensure it gets used.
     #[track_caller]
     pub fn ty_error(self) -> Ty<'tcx> {
diff --git a/compiler/rustc_query_impl/src/lib.rs b/compiler/rustc_query_impl/src/lib.rs
index e50a8c191ad..aa9c5bc5aba 100644
--- a/compiler/rustc_query_impl/src/lib.rs
+++ b/compiler/rustc_query_impl/src/lib.rs
@@ -19,7 +19,7 @@ extern crate tracing;
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_errors::DiagnosticBuilder;
-use rustc_middle::dep_graph;
+use rustc_middle::dep_graph::{self, DepKindStruct};
 use rustc_middle::ty::query::{query_keys, query_storage, query_stored, query_values};
 use rustc_middle::ty::query::{Providers, QueryEngine};
 use rustc_middle::ty::{self, TyCtxt};
@@ -29,7 +29,6 @@ use rustc_span::Span;
 #[macro_use]
 mod plumbing;
 pub use plumbing::QueryCtxt;
-use plumbing::QueryStruct;
 use rustc_query_system::query::*;
 
 mod stats;
diff --git a/compiler/rustc_query_impl/src/plumbing.rs b/compiler/rustc_query_impl/src/plumbing.rs
index 10dac9953aa..043e6b1c151 100644
--- a/compiler/rustc_query_impl/src/plumbing.rs
+++ b/compiler/rustc_query_impl/src/plumbing.rs
@@ -55,7 +55,7 @@ impl QueryContext for QueryCtxt<'tcx> {
 
     fn try_load_from_on_disk_cache(&self, dep_node: &DepNode) {
         let cb = &super::QUERY_CALLBACKS[dep_node.kind as usize];
-        (cb.try_load_from_on_disk_cache)(*self, dep_node)
+        (cb.try_load_from_on_disk_cache)(**self, dep_node)
     }
 
     fn try_force_from_dep_node(&self, dep_node: &DepNode) -> bool {
@@ -80,7 +80,7 @@ impl QueryContext for QueryCtxt<'tcx> {
         );
 
         let cb = &super::QUERY_CALLBACKS[dep_node.kind as usize];
-        (cb.force_from_dep_node)(*self, dep_node)
+        (cb.force_from_dep_node)(**self, dep_node)
     }
 
     // Interactions with on_disk_cache
@@ -193,60 +193,6 @@ impl<'tcx> QueryCtxt<'tcx> {
     }
 }
 
-/// This struct stores metadata about each Query.
-///
-/// Information is retrieved by indexing the `QUERIES` array using the integer value
-/// of the `DepKind`. Overall, this allows to implement `QueryContext` using this manual
-/// jump table instead of large matches.
-pub struct QueryStruct {
-    /// The red/green evaluation system will try to mark a specific DepNode in the
-    /// dependency graph as green by recursively trying to mark the dependencies of
-    /// that `DepNode` as green. While doing so, it will sometimes encounter a `DepNode`
-    /// where we don't know if it is red or green and we therefore actually have
-    /// to recompute its value in order to find out. Since the only piece of
-    /// information that we have at that point is the `DepNode` we are trying to
-    /// re-evaluate, we need some way to re-run a query from just that. This is what
-    /// `force_from_dep_node()` implements.
-    ///
-    /// In the general case, a `DepNode` consists of a `DepKind` and an opaque
-    /// GUID/fingerprint that will uniquely identify the node. This GUID/fingerprint
-    /// is usually constructed by computing a stable hash of the query-key that the
-    /// `DepNode` corresponds to. Consequently, it is not in general possible to go
-    /// back from hash to query-key (since hash functions are not reversible). For
-    /// this reason `force_from_dep_node()` is expected to fail from time to time
-    /// because we just cannot find out, from the `DepNode` alone, what the
-    /// corresponding query-key is and therefore cannot re-run the query.
-    ///
-    /// The system deals with this case letting `try_mark_green` fail which forces
-    /// the root query to be re-evaluated.
-    ///
-    /// Now, if `force_from_dep_node()` would always fail, it would be pretty useless.
-    /// Fortunately, we can use some contextual information that will allow us to
-    /// reconstruct query-keys for certain kinds of `DepNode`s. In particular, we
-    /// enforce by construction that the GUID/fingerprint of certain `DepNode`s is a
-    /// valid `DefPathHash`. Since we also always build a huge table that maps every
-    /// `DefPathHash` in the current codebase to the corresponding `DefId`, we have
-    /// everything we need to re-run the query.
-    ///
-    /// Take the `mir_promoted` query as an example. Like many other queries, it
-    /// just has a single parameter: the `DefId` of the item it will compute the
-    /// validated MIR for. Now, when we call `force_from_dep_node()` on a `DepNode`
-    /// with kind `MirValidated`, we know that the GUID/fingerprint of the `DepNode`
-    /// is actually a `DefPathHash`, and can therefore just look up the corresponding
-    /// `DefId` in `tcx.def_path_hash_to_def_id`.
-    ///
-    /// When you implement a new query, it will likely have a corresponding new
-    /// `DepKind`, and you'll have to support it here in `force_from_dep_node()`. As
-    /// a rule of thumb, if your query takes a `DefId` or `LocalDefId` as sole parameter,
-    /// then `force_from_dep_node()` should not fail for it. Otherwise, you can just
-    /// add it to the "We don't have enough information to reconstruct..." group in
-    /// the match below.
-    pub(crate) force_from_dep_node: fn(tcx: QueryCtxt<'_>, dep_node: &DepNode) -> bool,
-
-    /// Invoke a query to put the on-disk cached value in memory.
-    pub(crate) try_load_from_on_disk_cache: fn(QueryCtxt<'_>, &DepNode),
-}
-
 macro_rules! handle_cycle_error {
     ([][$tcx: expr, $error:expr]) => {{
         $error.emit();
@@ -425,28 +371,45 @@ macro_rules! define_queries {
             use rustc_query_system::dep_graph::FingerprintStyle;
 
             // We use this for most things when incr. comp. is turned off.
-            pub const Null: QueryStruct = QueryStruct {
+            pub const Null: DepKindStruct = DepKindStruct {
+                is_anon: false,
+                is_eval_always: false,
+
+                fingerprint_style: || FingerprintStyle::Unit,
                 force_from_dep_node: |_, dep_node| bug!("force_from_dep_node: encountered {:?}", dep_node),
                 try_load_from_on_disk_cache: |_, _| {},
             };
 
-            pub const TraitSelect: QueryStruct = QueryStruct {
+            pub const TraitSelect: DepKindStruct = DepKindStruct {
+                is_anon: true,
+                is_eval_always: false,
+
+                fingerprint_style: || FingerprintStyle::Unit,
                 force_from_dep_node: |_, _| false,
                 try_load_from_on_disk_cache: |_, _| {},
             };
 
-            pub const CompileCodegenUnit: QueryStruct = QueryStruct {
+            pub const CompileCodegenUnit: DepKindStruct = DepKindStruct {
+                is_anon: false,
+                is_eval_always: false,
+
+                fingerprint_style: || FingerprintStyle::Opaque,
                 force_from_dep_node: |_, _| false,
                 try_load_from_on_disk_cache: |_, _| {},
             };
 
-            pub const CompileMonoItem: QueryStruct = QueryStruct {
+            pub const CompileMonoItem: DepKindStruct = DepKindStruct {
+                is_anon: false,
+                is_eval_always: false,
+
+                fingerprint_style: || FingerprintStyle::Opaque,
                 force_from_dep_node: |_, _| false,
                 try_load_from_on_disk_cache: |_, _| {},
             };
 
-            $(pub const $name: QueryStruct = {
+            $(pub const $name: DepKindStruct = {
                 const is_anon: bool = is_anon!([$($modifiers)*]);
+                const is_eval_always: bool = is_eval_always!([$($modifiers)*]);
 
                 #[inline(always)]
                 fn fingerprint_style() -> FingerprintStyle {
@@ -458,11 +421,13 @@ macro_rules! define_queries {
                     <query_keys::$name<'_> as DepNodeParams<TyCtxt<'_>>>::recover(tcx, dep_node)
                 }
 
-                fn force_from_dep_node(tcx: QueryCtxt<'_>, dep_node: &DepNode) -> bool {
+                fn force_from_dep_node(tcx: TyCtxt<'_>, dep_node: &DepNode) -> bool {
+                    let tcx = QueryCtxt::from_tcx(tcx);
                     force_query::<queries::$name<'_>, _>(tcx, dep_node)
                 }
 
-                fn try_load_from_on_disk_cache(tcx: QueryCtxt<'_>, dep_node: &DepNode) {
+                fn try_load_from_on_disk_cache(tcx: TyCtxt<'_>, dep_node: &DepNode) {
+                    let tcx = QueryCtxt::from_tcx(tcx);
                     if is_anon {
                         return
                     }
@@ -479,14 +444,17 @@ macro_rules! define_queries {
                     }
                 }
 
-                QueryStruct {
+                DepKindStruct {
+                    is_anon,
+                    is_eval_always,
+                    fingerprint_style,
                     force_from_dep_node,
                     try_load_from_on_disk_cache,
                 }
             };)*
         }
 
-        static QUERY_CALLBACKS: &[QueryStruct] = &make_dep_kind_array!(query_callbacks);
+        pub static QUERY_CALLBACKS: &[DepKindStruct] = &make_dep_kind_array!(query_callbacks);
     }
 }
 
diff --git a/compiler/rustc_query_system/src/dep_graph/dep_node.rs b/compiler/rustc_query_system/src/dep_graph/dep_node.rs
index 4fb895716b2..19000badf75 100644
--- a/compiler/rustc_query_system/src/dep_graph/dep_node.rs
+++ b/compiler/rustc_query_system/src/dep_graph/dep_node.rs
@@ -60,8 +60,11 @@ impl<K: DepKind> DepNode<K> {
     /// Creates a new, parameterless DepNode. This method will assert
     /// that the DepNode corresponding to the given DepKind actually
     /// does not require any parameters.
-    pub fn new_no_params(kind: K) -> DepNode<K> {
-        debug_assert_eq!(kind.fingerprint_style(), FingerprintStyle::Unit);
+    pub fn new_no_params<Ctxt>(tcx: Ctxt, kind: K) -> DepNode<K>
+    where
+        Ctxt: super::DepContext<DepKind = K>,
+    {
+        debug_assert_eq!(tcx.fingerprint_style(kind), FingerprintStyle::Unit);
         DepNode { kind, hash: Fingerprint::ZERO.into() }
     }
 
@@ -75,7 +78,7 @@ impl<K: DepKind> DepNode<K> {
 
         #[cfg(debug_assertions)]
         {
-            if !kind.fingerprint_style().reconstructible()
+            if !tcx.fingerprint_style(kind).reconstructible()
                 && (tcx.sess().opts.debugging_opts.incremental_info
                     || tcx.sess().opts.debugging_opts.query_dep_graph)
             {
diff --git a/compiler/rustc_query_system/src/dep_graph/graph.rs b/compiler/rustc_query_system/src/dep_graph/graph.rs
index 66355f7cec9..5822370388b 100644
--- a/compiler/rustc_query_system/src/dep_graph/graph.rs
+++ b/compiler/rustc_query_system/src/dep_graph/graph.rs
@@ -252,7 +252,7 @@ impl<K: DepKind> DepGraph<K> {
             key
         );
 
-        let task_deps = if key.kind.is_eval_always() {
+        let task_deps = if cx.dep_context().is_eval_always(key.kind) {
             None
         } else {
             Some(Lock::new(TaskDeps {
@@ -316,7 +316,7 @@ impl<K: DepKind> DepGraph<K> {
     where
         OP: FnOnce() -> R,
     {
-        debug_assert!(!dep_kind.is_eval_always());
+        debug_assert!(!cx.is_eval_always(dep_kind));
 
         if let Some(ref data) = self.data {
             let task_deps = Lock::new(TaskDeps::default());
@@ -493,7 +493,7 @@ impl<K: DepKind> DepGraph<K> {
         tcx: Ctxt,
         dep_node: &DepNode<K>,
     ) -> Option<(SerializedDepNodeIndex, DepNodeIndex)> {
-        debug_assert!(!dep_node.kind.is_eval_always());
+        debug_assert!(!tcx.dep_context().is_eval_always(dep_node.kind));
 
         // Return None if the dep graph is disabled
         let data = self.data.as_ref()?;
@@ -553,7 +553,7 @@ impl<K: DepKind> DepGraph<K> {
 
         // We don't know the state of this dependency. If it isn't
         // an eval_always node, let's try to mark it green recursively.
-        if !dep_dep_node.kind.is_eval_always() {
+        if !tcx.dep_context().is_eval_always(dep_dep_node.kind) {
             debug!(
                 "try_mark_previous_green({:?}) --- state of dependency {:?} ({}) \
                                  is unknown, trying to mark it green",
@@ -643,7 +643,7 @@ impl<K: DepKind> DepGraph<K> {
         }
 
         // We never try to mark eval_always nodes as green
-        debug_assert!(!dep_node.kind.is_eval_always());
+        debug_assert!(!tcx.dep_context().is_eval_always(dep_node.kind));
 
         debug_assert_eq!(data.previous.index_to_node(prev_dep_node_index), *dep_node);
 
diff --git a/compiler/rustc_query_system/src/dep_graph/mod.rs b/compiler/rustc_query_system/src/dep_graph/mod.rs
index 639038d008e..6a81c401105 100644
--- a/compiler/rustc_query_system/src/dep_graph/mod.rs
+++ b/compiler/rustc_query_system/src/dep_graph/mod.rs
@@ -32,6 +32,11 @@ pub trait DepContext: Copy {
 
     /// Access the compiler session.
     fn sess(&self) -> &Session;
+
+    /// Return whether this kind always require evaluation.
+    fn is_eval_always(&self, kind: Self::DepKind) -> bool;
+
+    fn fingerprint_style(&self, kind: Self::DepKind) -> FingerprintStyle;
 }
 
 pub trait HasDepContext: Copy {
@@ -75,9 +80,6 @@ impl FingerprintStyle {
 pub trait DepKind: Copy + fmt::Debug + Eq + Hash + Send + Encodable<FileEncoder> + 'static {
     const NULL: Self;
 
-    /// Return whether this kind always require evaluation.
-    fn is_eval_always(&self) -> bool;
-
     /// Implementation of `std::fmt::Debug` for `DepNode`.
     fn debug_node(node: &DepNode<Self>, f: &mut fmt::Formatter<'_>) -> fmt::Result;
 
@@ -90,6 +92,4 @@ pub trait DepKind: Copy + fmt::Debug + Eq + Hash + Send + Encodable<FileEncoder>
     fn read_deps<OP>(op: OP)
     where
         OP: for<'a> FnOnce(Option<&'a Lock<TaskDeps<Self>>>);
-
-    fn fingerprint_style(&self) -> FingerprintStyle;
 }
diff --git a/compiler/rustc_query_system/src/query/plumbing.rs b/compiler/rustc_query_system/src/query/plumbing.rs
index e3bfd81b851..aa35347534d 100644
--- a/compiler/rustc_query_system/src/query/plumbing.rs
+++ b/compiler/rustc_query_system/src/query/plumbing.rs
@@ -2,7 +2,7 @@
 //! generate the actual methods on tcx which find and execute the provider,
 //! manage the caches, and so forth.
 
-use crate::dep_graph::{DepContext, DepKind, DepNode, DepNodeIndex, DepNodeParams};
+use crate::dep_graph::{DepContext, DepNode, DepNodeIndex, DepNodeParams};
 use crate::query::caches::QueryCache;
 use crate::query::config::{QueryDescription, QueryVtable, QueryVtableExt};
 use crate::query::job::{
@@ -520,14 +520,6 @@ where
         let result = query.try_load_from_disk(tcx, prev_dep_node_index);
         prof_timer.finish_with_query_invocation_id(dep_node_index.into());
 
-        // We always expect to find a cached result for things that
-        // can be forced from `DepNode`.
-        debug_assert!(
-            !dep_node.kind.fingerprint_style().reconstructible() || result.is_some(),
-            "missing on-disk cache entry for {:?}",
-            dep_node
-        );
-
         if let Some(result) = result {
             // If `-Zincremental-verify-ich` is specified, re-hash results from
             // the cache and make sure that they have the expected fingerprint.
@@ -537,6 +529,14 @@ where
 
             return Some((result, dep_node_index));
         }
+
+        // We always expect to find a cached result for things that
+        // can be forced from `DepNode`.
+        debug_assert!(
+            !tcx.dep_context().fingerprint_style(dep_node.kind).reconstructible(),
+            "missing on-disk cache entry for {:?}",
+            dep_node
+        );
     }
 
     // We could not load a result from the on-disk cache, so