Trait QueryDispatcher 

pub trait QueryDispatcher<'tcx>: Copy {
    type Qcx: QueryContext<'tcx>;
    type Key: DepNodeParams<<<This as QueryDispatcher<'tcx>>::Qcx as HasDepContext>::DepContext> + Eq + Hash + Copy + Debug;
    type Value: Copy;
    type Cache: QueryCache<Key = Self::Key, Value = Self::Value>;

    // Required methods
    fn name(self) -> &'static str;
    fn format_value(self) -> fn(&Self::Value) -> String;
    fn query_state<'a>(self, tcx: Self::Qcx) -> &'a QueryState<'tcx, Self::Key>;
    fn query_cache<'a>(self, tcx: Self::Qcx) -> &'a Self::Cache;
    fn will_cache_on_disk_for_key(
        self,
        tcx: <<This as QueryDispatcher<'tcx>>::Qcx as HasDepContext>::DepContext,
        key: &Self::Key,
    ) -> bool;
    fn execute_query(
        self,
        tcx: <<This as QueryDispatcher<'tcx>>::Qcx as HasDepContext>::DepContext,
        k: Self::Key,
    ) -> Self::Value;
    fn compute(self, tcx: Self::Qcx, key: Self::Key) -> Self::Value;
    fn try_load_from_disk(
        self,
        tcx: Self::Qcx,
        key: &Self::Key,
        prev_index: SerializedDepNodeIndex,
        index: DepNodeIndex,
    ) -> Option<Self::Value>;
    fn is_loadable_from_disk(
        self,
        qcx: Self::Qcx,
        key: &Self::Key,
        idx: SerializedDepNodeIndex,
    ) -> bool;
    fn value_from_cycle_error(
        self,
        tcx: <<This as QueryDispatcher<'tcx>>::Qcx as HasDepContext>::DepContext,
        cycle_error: &CycleError<QueryStackFrameExtra>,
        guar: ErrorGuaranteed,
    ) -> Self::Value;
    fn anon(self) -> bool;
    fn eval_always(self) -> bool;
    fn depth_limit(self) -> bool;
    fn feedable(self) -> bool;
    fn dep_kind(self) -> DepKind;
    fn cycle_error_handling(self) -> CycleErrorHandling;
    fn hash_result(self) -> HashResult<Self::Value>;

    // Provided method
    fn construct_dep_node(
        self,
        tcx: <<This as QueryDispatcher<'tcx>>::Qcx as HasDepContext>::DepContext,
        key: &Self::Key,
    ) -> DepNode { ... }
}

Trait that can be used as a vtable for a single query, providing operations and metadata for that query.

Implemented by rustc_query_impl::SemiDynamicQueryDispatcher, which mostly delegates to rustc_middle::query::plumbing::QueryVTable. Those types are not visible from this rustc_query_system crate.

“Dispatcher” should be understood as a near-synonym of “vtable”.

Required Associated Types

type Qcx: QueryContext<'tcx>

Query context used by this dispatcher, i.e. rustc_query_impl::QueryCtxt.

type Key: DepNodeParams<<<This as QueryDispatcher<'tcx>>::Qcx as HasDepContext>::DepContext> + Eq + Hash + Copy + Debug

type Value: Copy

type Cache: QueryCache<Key = Self::Key, Value = Self::Value>

Required Methods

fn name(self) -> &'static str

fn format_value(self) -> fn(&Self::Value) -> String

fn query_state<'a>(self, tcx: Self::Qcx) -> &'a QueryState<'tcx, Self::Key>

fn query_cache<'a>(self, tcx: Self::Qcx) -> &'a Self::Cache

fn will_cache_on_disk_for_key( self, tcx: <<This as QueryDispatcher<'tcx>>::Qcx as HasDepContext>::DepContext, key: &Self::Key, ) -> bool

fn execute_query( self, tcx: <<This as QueryDispatcher<'tcx>>::Qcx as HasDepContext>::DepContext, k: Self::Key, ) -> Self::Value

fn compute(self, tcx: Self::Qcx, key: Self::Key) -> Self::Value

fn try_load_from_disk( self, tcx: Self::Qcx, key: &Self::Key, prev_index: SerializedDepNodeIndex, index: DepNodeIndex, ) -> Option<Self::Value>

fn is_loadable_from_disk( self, qcx: Self::Qcx, key: &Self::Key, idx: SerializedDepNodeIndex, ) -> bool

fn value_from_cycle_error( self, tcx: <<This as QueryDispatcher<'tcx>>::Qcx as HasDepContext>::DepContext, cycle_error: &CycleError<QueryStackFrameExtra>, guar: ErrorGuaranteed, ) -> Self::Value

Synthesize an error value to let compilation continue after a cycle.

fn anon(self) -> bool

fn eval_always(self) -> bool

fn depth_limit(self) -> bool

fn feedable(self) -> bool

fn dep_kind(self) -> DepKind

fn cycle_error_handling(self) -> CycleErrorHandling

fn hash_result(self) -> HashResult<Self::Value>

Provided Methods

fn construct_dep_node( self, tcx: <<This as QueryDispatcher<'tcx>>::Qcx as HasDepContext>::DepContext, key: &Self::Key, ) -> DepNode

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors