compiler/rustc_query_system/src/query/config.rs

   1 //! Query configuration and description traits.
   2
   3 use crate::dep_graph::DepNode;
   4 use crate::dep_graph::SerializedDepNodeIndex;
   5 use crate::query::caches::QueryCache;
   6 use crate::query::{QueryCacheStore, QueryContext, QueryState};
   7
   8 use rustc_data_structures::fingerprint::Fingerprint;
   9 use rustc_errors::DiagnosticBuilder;
  10 use std::fmt::Debug;
  11 use std::hash::Hash;
  12
  13 pub trait QueryConfig {
  14     const NAME: &'static str;
  15
  16     type Key: Eq + Hash + Clone + Debug;
  17     type Value;
  18     type Stored: Clone;
  19 }
  20
  21 pub(crate) struct QueryVtable<CTX: QueryContext, K, V> {
  22     pub anon: bool,
  23     pub dep_kind: CTX::DepKind,
  24     pub eval_always: bool,
  25
  26     // Don't use this method to compute query results, instead use the methods on TyCtxt
  27     pub compute: fn(CTX, K) -> V,
  28
  29     pub hash_result: fn(&mut CTX::StableHashingContext, &V) -> Option<Fingerprint>,
  30     pub handle_cycle_error: fn(CTX, DiagnosticBuilder<'_>) -> V,
  31     pub cache_on_disk: fn(CTX, &K, Option<&V>) -> bool,
  32     pub try_load_from_disk: fn(CTX, SerializedDepNodeIndex) -> Option<V>,
  33 }
  34
  35 impl<CTX: QueryContext, K, V> QueryVtable<CTX, K, V> {
  36     pub(crate) fn to_dep_node(&self, tcx: CTX::DepContext, key: &K) -> DepNode<CTX::DepKind>
  37     where
  38         K: crate::dep_graph::DepNodeParams<CTX::DepContext>,
  39     {
  40         DepNode::construct(tcx, self.dep_kind, key)
  41     }
  42
  43     pub(crate) fn compute(&self, tcx: CTX, key: K) -> V {
  44         (self.compute)(tcx, key)
  45     }
  46
  47     pub(crate) fn hash_result(
  48         &self,
  49         hcx: &mut CTX::StableHashingContext,
  50         value: &V,
  51     ) -> Option<Fingerprint> {
  52         (self.hash_result)(hcx, value)
  53     }
  54
  55     pub(crate) fn handle_cycle_error(&self, tcx: CTX, diag: DiagnosticBuilder<'_>) -> V {
  56         (self.handle_cycle_error)(tcx, diag)
  57     }
  58
  59     pub(crate) fn cache_on_disk(&self, tcx: CTX, key: &K, value: Option<&V>) -> bool {
  60         (self.cache_on_disk)(tcx, key, value)
  61     }
  62
  63     pub(crate) fn try_load_from_disk(&self, tcx: CTX, index: SerializedDepNodeIndex) -> Option<V> {
  64         (self.try_load_from_disk)(tcx, index)
  65     }
  66 }
  67
  68 pub trait QueryAccessors<CTX: QueryContext>: QueryConfig {
  69     const ANON: bool;
  70     const EVAL_ALWAYS: bool;
  71     const DEP_KIND: CTX::DepKind;
  72
  73     type Cache: QueryCache<Key = Self::Key, Stored = Self::Stored, Value = Self::Value>;
  74
  75     // Don't use this method to access query results, instead use the methods on TyCtxt
  76     fn query_state<'a>(tcx: CTX) -> &'a QueryState<CTX::DepKind, Self::Key>
  77     where
  78         CTX: 'a;
  79
  80     // Don't use this method to access query results, instead use the methods on TyCtxt
  81     fn query_cache<'a>(tcx: CTX) -> &'a QueryCacheStore<Self::Cache>
  82     where
  83         CTX: 'a;
  84
  85     // Don't use this method to compute query results, instead use the methods on TyCtxt
  86     fn compute(tcx: CTX, key: Self::Key) -> Self::Value;
  87
  88     fn hash_result(
  89         hcx: &mut CTX::StableHashingContext,
  90         result: &Self::Value,
  91     ) -> Option<Fingerprint>;
  92
  93     fn handle_cycle_error(tcx: CTX, diag: DiagnosticBuilder<'_>) -> Self::Value;
  94 }
  95
  96 pub trait QueryDescription<CTX: QueryContext>: QueryAccessors<CTX> {
  97     fn describe(tcx: CTX, key: Self::Key) -> String;
  98
  99     #[inline]
 100     fn cache_on_disk(_: CTX, _: &Self::Key, _: Option<&Self::Value>) -> bool {
 101         false
 102     }
 103
 104     fn try_load_from_disk(_: CTX, _: SerializedDepNodeIndex) -> Option<Self::Value> {
 105         panic!("QueryDescription::load_from_disk() called for an unsupported query.")
 106     }
 107 }
 108
 109 pub(crate) trait QueryVtableExt<CTX: QueryContext, K, V> {
 110     const VTABLE: QueryVtable<CTX, K, V>;
 111 }
 112
 113 impl<CTX, Q> QueryVtableExt<CTX, Q::Key, Q::Value> for Q
 114 where
 115     CTX: QueryContext,
 116     Q: QueryDescription<CTX>,
 117 {
 118     const VTABLE: QueryVtable<CTX, Q::Key, Q::Value> = QueryVtable {
 119         anon: Q::ANON,
 120         dep_kind: Q::DEP_KIND,
 121         eval_always: Q::EVAL_ALWAYS,
 122         compute: Q::compute,
 123         hash_result: Q::hash_result,
 124         handle_cycle_error: Q::handle_cycle_error,
 125         cache_on_disk: Q::cache_on_disk,
 126         try_load_from_disk: Q::try_load_from_disk,
 127     };
 128 }