diff --git a/Cargo.lock b/Cargo.lock index 8bf6198913530..f61f333b6c91e 100644 --- a/Cargo.lock +++ b/Cargo.lock @@ -4042,12 +4042,12 @@ version = "0.0.0" dependencies = [ "log", "parking_lot 0.9.0", - "rustc_ast", + "rustc-rayon-core", "rustc_data_structures", "rustc_errors", - "rustc_hir", "rustc_index", "rustc_macros", + "rustc_span", "serialize", "smallvec 1.0.0", ] diff --git a/src/librustc/dep_graph/mod.rs b/src/librustc/dep_graph/mod.rs index 3c39597584df5..f56df19bfb061 100644 --- a/src/librustc/dep_graph/mod.rs +++ b/src/librustc/dep_graph/mod.rs @@ -8,7 +8,6 @@ use rustc_errors::Diagnostic; use rustc_hir::def_id::DefId; mod dep_node; -mod safe; pub(crate) use rustc_query_system::dep_graph::DepNodeParams; pub use rustc_query_system::dep_graph::{ @@ -17,8 +16,6 @@ pub use rustc_query_system::dep_graph::{ }; pub use dep_node::{label_strs, DepConstructor, DepKind, DepNode, DepNodeExt}; -pub use safe::AssertDepGraphSafe; -pub use safe::DepGraphSafe; pub type DepGraph = rustc_query_system::dep_graph::DepGraph; pub type TaskDeps = rustc_query_system::dep_graph::TaskDeps; @@ -27,6 +24,8 @@ pub type PreviousDepGraph = rustc_query_system::dep_graph::PreviousDepGraph; impl rustc_query_system::dep_graph::DepKind for DepKind { + const NULL: Self = DepKind::Null; + fn is_eval_always(&self) -> bool { DepKind::is_eval_always(self) } @@ -82,6 +81,10 @@ impl rustc_query_system::dep_graph::DepKind for DepKind { op(icx.task_deps) }) } + + fn can_reconstruct_query_key(&self) -> bool { + DepKind::can_reconstruct_query_key(self) + } } impl<'tcx> DepContext for TyCtxt<'tcx> { @@ -92,6 +95,10 @@ impl<'tcx> DepContext for TyCtxt<'tcx> { TyCtxt::create_stable_hashing_context(*self) } + fn debug_dep_tasks(&self) -> bool { + self.sess.opts.debugging_opts.dep_tasks + } + fn try_force_from_dep_node(&self, dep_node: &DepNode) -> bool { // FIXME: This match is just a workaround for incremental bugs and should // be removed. https://github.com/rust-lang/rust/issues/62649 is one such @@ -160,6 +167,14 @@ impl<'tcx> DepContext for TyCtxt<'tcx> { self.queries.on_disk_cache.store_diagnostics(dep_node_index, diagnostics) } + fn store_diagnostics_for_anon_node( + &self, + dep_node_index: DepNodeIndex, + diagnostics: ThinVec, + ) { + self.queries.on_disk_cache.store_diagnostics_for_anon_node(dep_node_index, diagnostics) + } + fn profiler(&self) -> &SelfProfilerRef { &self.prof } @@ -169,23 +184,3 @@ fn def_id_corresponds_to_hir_dep_node(tcx: TyCtxt<'_>, def_id: DefId) -> bool { let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap(); def_id.index == hir_id.owner.local_def_index } - -impl rustc_query_system::HashStableContext for StableHashingContext<'_> { - fn debug_dep_tasks(&self) -> bool { - self.sess().opts.debugging_opts.dep_tasks - } -} - -impl rustc_query_system::HashStableContextProvider> for TyCtxt<'tcx> { - fn get_stable_hashing_context(&self) -> StableHashingContext<'tcx> { - self.create_stable_hashing_context() - } -} - -impl rustc_query_system::HashStableContextProvider> - for StableHashingContext<'a> -{ - fn get_stable_hashing_context(&self) -> Self { - self.clone() - } -} diff --git a/src/librustc/dep_graph/safe.rs b/src/librustc/dep_graph/safe.rs deleted file mode 100644 index 47a1c09672ff6..0000000000000 --- a/src/librustc/dep_graph/safe.rs +++ /dev/null @@ -1,9 +0,0 @@ -//! The `DepGraphSafe` trait - -use crate::ty::TyCtxt; - -pub use rustc_query_system::dep_graph::{AssertDepGraphSafe, DepGraphSafe}; - -/// The type context itself can be used to access all kinds of tracked -/// state, but those accesses should always generate read events. -impl<'tcx> DepGraphSafe for TyCtxt<'tcx> {} diff --git a/src/librustc/ich/hcx.rs b/src/librustc/ich/hcx.rs index a9466e8252de7..ac3faae072b68 100644 --- a/src/librustc/ich/hcx.rs +++ b/src/librustc/ich/hcx.rs @@ -194,8 +194,6 @@ impl<'a> StableHashingContextProvider<'a> for StableHashingContext<'a> { } } -impl<'a> crate::dep_graph::DepGraphSafe for StableHashingContext<'a> {} - impl<'a> HashStable> for ast::NodeId { fn hash_stable(&self, _: &mut StableHashingContext<'a>, _: &mut StableHasher) { panic!("Node IDs should not appear in incremental state"); diff --git a/src/librustc/ty/context.rs b/src/librustc/ty/context.rs index c1d13b0353ebb..3d4806f53be79 100644 --- a/src/librustc/ty/context.rs +++ b/src/librustc/ty/context.rs @@ -1603,7 +1603,7 @@ nop_list_lift! {substs; GenericArg<'a> => GenericArg<'tcx>} pub mod tls { use super::{ptr_eq, GlobalCtxt, TyCtxt}; - use crate::dep_graph::TaskDeps; + use crate::dep_graph::{DepKind, TaskDeps}; use crate::ty::query; use rustc_data_structures::sync::{self, Lock}; use rustc_data_structures::thin_vec::ThinVec; @@ -1630,7 +1630,7 @@ pub mod tls { /// The current query job, if any. This is updated by `JobOwner::start` in /// `ty::query::plumbing` when executing a query. - pub query: Option, + pub query: Option>, /// Where to store diagnostics for the current query job, if any. /// This is updated by `JobOwner::start` in `ty::query::plumbing` when executing a query. diff --git a/src/librustc/ty/query/config.rs b/src/librustc/ty/query/config.rs deleted file mode 100644 index 72a0fdf156726..0000000000000 --- a/src/librustc/ty/query/config.rs +++ /dev/null @@ -1,82 +0,0 @@ -use crate::dep_graph::SerializedDepNodeIndex; -use crate::dep_graph::{DepKind, DepNode}; -use crate::ty::query::caches::QueryCache; -use crate::ty::query::plumbing::CycleError; -use crate::ty::query::QueryState; -use crate::ty::TyCtxt; -use rustc_data_structures::profiling::ProfileCategory; -use rustc_hir::def_id::DefId; - -use crate::ich::StableHashingContext; -use rustc_data_structures::fingerprint::Fingerprint; -use std::borrow::Cow; -use std::fmt::Debug; -use std::hash::Hash; - -// Query configuration and description traits. - -// FIXME(eddyb) false positive, the lifetime parameter is used for `Key`/`Value`. -#[allow(unused_lifetimes)] -pub trait QueryConfig<'tcx> { - const NAME: &'static str; - const CATEGORY: ProfileCategory; - - type Key: Eq + Hash + Clone + Debug; - type Value: Clone; -} - -pub(crate) trait QueryAccessors<'tcx>: QueryConfig<'tcx> { - const ANON: bool; - const EVAL_ALWAYS: bool; - const DEP_KIND: DepKind; - - type Cache: QueryCache; - - // Don't use this method to access query results, instead use the methods on TyCtxt - fn query_state<'a>(tcx: TyCtxt<'tcx>) -> &'a QueryState<'tcx, Self::Cache>; - - fn to_dep_node(tcx: TyCtxt<'tcx>, key: &Self::Key) -> DepNode; - - // Don't use this method to compute query results, instead use the methods on TyCtxt - fn compute(tcx: TyCtxt<'tcx>, key: Self::Key) -> Self::Value; - - fn hash_result(hcx: &mut StableHashingContext<'_>, result: &Self::Value) - -> Option; - - fn handle_cycle_error(tcx: TyCtxt<'tcx>, error: CycleError<'tcx>) -> Self::Value; -} - -pub(crate) trait QueryDescription<'tcx>: QueryAccessors<'tcx> { - fn describe(tcx: TyCtxt<'_>, key: Self::Key) -> Cow<'static, str>; - - #[inline] - fn cache_on_disk(_: TyCtxt<'tcx>, _: Self::Key, _: Option<&Self::Value>) -> bool { - false - } - - fn try_load_from_disk(_: TyCtxt<'tcx>, _: SerializedDepNodeIndex) -> Option { - bug!("QueryDescription::load_from_disk() called for an unsupported query.") - } -} - -impl<'tcx, M: QueryAccessors<'tcx, Key = DefId>> QueryDescription<'tcx> for M { - default fn describe(tcx: TyCtxt<'_>, def_id: DefId) -> Cow<'static, str> { - if !tcx.sess.verbose() { - format!("processing `{}`", tcx.def_path_str(def_id)).into() - } else { - let name = ::std::any::type_name::(); - format!("processing {:?} with query `{}`", def_id, name).into() - } - } - - default fn cache_on_disk(_: TyCtxt<'tcx>, _: Self::Key, _: Option<&Self::Value>) -> bool { - false - } - - default fn try_load_from_disk( - _: TyCtxt<'tcx>, - _: SerializedDepNodeIndex, - ) -> Option { - bug!("QueryDescription::load_from_disk() called for an unsupported query.") - } -} diff --git a/src/librustc/ty/query/job.rs b/src/librustc/ty/query/job.rs index 4e88fc5463794..5f7a9e81158e0 100644 --- a/src/librustc/ty/query/job.rs +++ b/src/librustc/ty/query/job.rs @@ -1,531 +1,12 @@ -use crate::dep_graph::DepKind; -use crate::ty::context::TyCtxt; -use crate::ty::query::plumbing::CycleError; -use crate::ty::query::Query; use crate::ty::tls; -use rustc_data_structures::fx::FxHashMap; -use rustc_span::Span; - -use std::convert::TryFrom; -use std::marker::PhantomData; -use std::num::NonZeroU32; - -#[cfg(parallel_compiler)] -use { - parking_lot::{Condvar, Mutex}, - rustc_data_structures::fx::FxHashSet, - rustc_data_structures::stable_hasher::{HashStable, StableHasher}, - rustc_data_structures::sync::Lock, - rustc_data_structures::sync::Lrc, - rustc_data_structures::{jobserver, OnDrop}, - rustc_rayon_core as rayon_core, - rustc_span::DUMMY_SP, - std::iter::FromIterator, - std::{mem, process, thread}, -}; - -/// Represents a span and a query key. -#[derive(Clone, Debug)] -pub struct QueryInfo<'tcx> { - /// The span corresponding to the reason for which this query was required. - pub span: Span, - pub query: Query<'tcx>, -} - -type QueryMap<'tcx> = FxHashMap>; - -/// A value uniquely identifiying an active query job within a shard in the query cache. -#[derive(Copy, Clone, Eq, PartialEq, Hash)] -pub struct QueryShardJobId(pub NonZeroU32); - -/// A value uniquely identifiying an active query job. -#[derive(Copy, Clone, Eq, PartialEq, Hash)] -pub struct QueryJobId { - /// Which job within a shard is this - pub job: QueryShardJobId, - - /// In which shard is this job - pub shard: u16, - - /// What kind of query this job is - pub kind: DepKind, -} - -impl QueryJobId { - pub fn new(job: QueryShardJobId, shard: usize, kind: DepKind) -> Self { - QueryJobId { job, shard: u16::try_from(shard).unwrap(), kind } - } - - fn query<'tcx>(self, map: &QueryMap<'tcx>) -> Query<'tcx> { - map.get(&self).unwrap().info.query.clone() - } - - #[cfg(parallel_compiler)] - fn span(self, map: &QueryMap<'_>) -> Span { - map.get(&self).unwrap().job.span - } - - #[cfg(parallel_compiler)] - fn parent(self, map: &QueryMap<'_>) -> Option { - map.get(&self).unwrap().job.parent - } - - #[cfg(parallel_compiler)] - fn latch<'a, 'tcx>(self, map: &'a QueryMap<'tcx>) -> Option<&'a QueryLatch<'tcx>> { - map.get(&self).unwrap().job.latch.as_ref() - } -} - -pub struct QueryJobInfo<'tcx> { - pub info: QueryInfo<'tcx>, - pub job: QueryJob<'tcx>, -} - -/// Represents an active query job. -#[derive(Clone)] -pub struct QueryJob<'tcx> { - pub id: QueryShardJobId, - - /// The span corresponding to the reason for which this query was required. - pub span: Span, - - /// The parent query job which created this job and is implicitly waiting on it. - pub parent: Option, - - /// The latch that is used to wait on this job. - #[cfg(parallel_compiler)] - latch: Option>, - - dummy: PhantomData>, -} - -impl<'tcx> QueryJob<'tcx> { - /// Creates a new query job. - pub fn new(id: QueryShardJobId, span: Span, parent: Option) -> Self { - QueryJob { - id, - span, - parent, - #[cfg(parallel_compiler)] - latch: None, - dummy: PhantomData, - } - } - - #[cfg(parallel_compiler)] - pub(super) fn latch(&mut self, _id: QueryJobId) -> QueryLatch<'tcx> { - if self.latch.is_none() { - self.latch = Some(QueryLatch::new()); - } - self.latch.as_ref().unwrap().clone() - } - - #[cfg(not(parallel_compiler))] - pub(super) fn latch(&mut self, id: QueryJobId) -> QueryLatch<'tcx> { - QueryLatch { id, dummy: PhantomData } - } - - /// Signals to waiters that the query is complete. - /// - /// This does nothing for single threaded rustc, - /// as there are no concurrent jobs which could be waiting on us - pub fn signal_complete(self) { - #[cfg(parallel_compiler)] - self.latch.map(|latch| latch.set()); - } -} - -#[cfg(not(parallel_compiler))] -#[derive(Clone)] -pub(super) struct QueryLatch<'tcx> { - id: QueryJobId, - dummy: PhantomData<&'tcx ()>, -} - -#[cfg(not(parallel_compiler))] -impl<'tcx> QueryLatch<'tcx> { - pub(super) fn find_cycle_in_stack(&self, tcx: TyCtxt<'tcx>, span: Span) -> CycleError<'tcx> { - let query_map = tcx.queries.try_collect_active_jobs().unwrap(); - - // Get the current executing query (waiter) and find the waitee amongst its parents - let mut current_job = tls::with_related_context(tcx, |icx| icx.query); - let mut cycle = Vec::new(); - - while let Some(job) = current_job { - let info = query_map.get(&job).unwrap(); - cycle.push(info.info.clone()); - - if job == self.id { - cycle.reverse(); - - // This is the end of the cycle - // The span entry we included was for the usage - // of the cycle itself, and not part of the cycle - // Replace it with the span which caused the cycle to form - cycle[0].span = span; - // Find out why the cycle itself was used - let usage = info - .job - .parent - .as_ref() - .map(|parent| (info.info.span, parent.query(&query_map))); - return CycleError { usage, cycle }; - } - - current_job = info.job.parent; - } - - panic!("did not find a cycle") - } -} - -#[cfg(parallel_compiler)] -struct QueryWaiter<'tcx> { - query: Option, - condvar: Condvar, - span: Span, - cycle: Lock>>, -} - -#[cfg(parallel_compiler)] -impl<'tcx> QueryWaiter<'tcx> { - fn notify(&self, registry: &rayon_core::Registry) { - rayon_core::mark_unblocked(registry); - self.condvar.notify_one(); - } -} - -#[cfg(parallel_compiler)] -struct QueryLatchInfo<'tcx> { - complete: bool, - waiters: Vec>>, -} - -#[cfg(parallel_compiler)] -#[derive(Clone)] -pub(super) struct QueryLatch<'tcx> { - info: Lrc>>, -} - -#[cfg(parallel_compiler)] -impl<'tcx> QueryLatch<'tcx> { - fn new() -> Self { - QueryLatch { - info: Lrc::new(Mutex::new(QueryLatchInfo { complete: false, waiters: Vec::new() })), - } - } - - /// Awaits for the query job to complete. - #[cfg(parallel_compiler)] - pub(super) fn wait_on(&self, tcx: TyCtxt<'tcx>, span: Span) -> Result<(), CycleError<'tcx>> { - tls::with_related_context(tcx, move |icx| { - let waiter = Lrc::new(QueryWaiter { - query: icx.query, - span, - cycle: Lock::new(None), - condvar: Condvar::new(), - }); - self.wait_on_inner(&waiter); - // FIXME: Get rid of this lock. We have ownership of the QueryWaiter - // although another thread may still have a Lrc reference so we cannot - // use Lrc::get_mut - let mut cycle = waiter.cycle.lock(); - match cycle.take() { - None => Ok(()), - Some(cycle) => Err(cycle), - } - }) - } - - /// Awaits the caller on this latch by blocking the current thread. - fn wait_on_inner(&self, waiter: &Lrc>) { - let mut info = self.info.lock(); - if !info.complete { - // We push the waiter on to the `waiters` list. It can be accessed inside - // the `wait` call below, by 1) the `set` method or 2) by deadlock detection. - // Both of these will remove it from the `waiters` list before resuming - // this thread. - info.waiters.push(waiter.clone()); - - // If this detects a deadlock and the deadlock handler wants to resume this thread - // we have to be in the `wait` call. This is ensured by the deadlock handler - // getting the self.info lock. - rayon_core::mark_blocked(); - jobserver::release_thread(); - waiter.condvar.wait(&mut info); - // Release the lock before we potentially block in `acquire_thread` - mem::drop(info); - jobserver::acquire_thread(); - } - } - - /// Sets the latch and resumes all waiters on it - fn set(&self) { - let mut info = self.info.lock(); - debug_assert!(!info.complete); - info.complete = true; - let registry = rayon_core::Registry::current(); - for waiter in info.waiters.drain(..) { - waiter.notify(®istry); - } - } - - /// Removes a single waiter from the list of waiters. - /// This is used to break query cycles. - fn extract_waiter(&self, waiter: usize) -> Lrc> { - let mut info = self.info.lock(); - debug_assert!(!info.complete); - // Remove the waiter from the list of waiters - info.waiters.remove(waiter) - } -} - -/// A resumable waiter of a query. The usize is the index into waiters in the query's latch -#[cfg(parallel_compiler)] -type Waiter = (QueryJobId, usize); - -/// Visits all the non-resumable and resumable waiters of a query. -/// Only waiters in a query are visited. -/// `visit` is called for every waiter and is passed a query waiting on `query_ref` -/// and a span indicating the reason the query waited on `query_ref`. -/// If `visit` returns Some, this function returns. -/// For visits of non-resumable waiters it returns the return value of `visit`. -/// For visits of resumable waiters it returns Some(Some(Waiter)) which has the -/// required information to resume the waiter. -/// If all `visit` calls returns None, this function also returns None. -#[cfg(parallel_compiler)] -fn visit_waiters<'tcx, F>( - query_map: &QueryMap<'tcx>, - query: QueryJobId, - mut visit: F, -) -> Option> -where - F: FnMut(Span, QueryJobId) -> Option>, -{ - // Visit the parent query which is a non-resumable waiter since it's on the same stack - if let Some(parent) = query.parent(query_map) { - if let Some(cycle) = visit(query.span(query_map), parent) { - return Some(cycle); - } - } - - // Visit the explicit waiters which use condvars and are resumable - if let Some(latch) = query.latch(query_map) { - for (i, waiter) in latch.info.lock().waiters.iter().enumerate() { - if let Some(waiter_query) = waiter.query { - if visit(waiter.span, waiter_query).is_some() { - // Return a value which indicates that this waiter can be resumed - return Some(Some((query, i))); - } - } - } - } - - None -} - -/// Look for query cycles by doing a depth first search starting at `query`. -/// `span` is the reason for the `query` to execute. This is initially DUMMY_SP. -/// If a cycle is detected, this initial value is replaced with the span causing -/// the cycle. -#[cfg(parallel_compiler)] -fn cycle_check<'tcx>( - query_map: &QueryMap<'tcx>, - query: QueryJobId, - span: Span, - stack: &mut Vec<(Span, QueryJobId)>, - visited: &mut FxHashSet, -) -> Option> { - if !visited.insert(query) { - return if let Some(p) = stack.iter().position(|q| q.1 == query) { - // We detected a query cycle, fix up the initial span and return Some - - // Remove previous stack entries - stack.drain(0..p); - // Replace the span for the first query with the cycle cause - stack[0].0 = span; - Some(None) - } else { - None - }; - } - - // Query marked as visited is added it to the stack - stack.push((span, query)); - - // Visit all the waiters - let r = visit_waiters(query_map, query, |span, successor| { - cycle_check(query_map, successor, span, stack, visited) - }); - - // Remove the entry in our stack if we didn't find a cycle - if r.is_none() { - stack.pop(); - } - - r -} - -/// Finds out if there's a path to the compiler root (aka. code which isn't in a query) -/// from `query` without going through any of the queries in `visited`. -/// This is achieved with a depth first search. -#[cfg(parallel_compiler)] -fn connected_to_root<'tcx>( - query_map: &QueryMap<'tcx>, - query: QueryJobId, - visited: &mut FxHashSet, -) -> bool { - // We already visited this or we're deliberately ignoring it - if !visited.insert(query) { - return false; - } - - // This query is connected to the root (it has no query parent), return true - if query.parent(query_map).is_none() { - return true; - } - - visit_waiters(query_map, query, |_, successor| { - connected_to_root(query_map, successor, visited).then_some(None) - }) - .is_some() -} - -// Deterministically pick an query from a list -#[cfg(parallel_compiler)] -fn pick_query<'a, 'tcx, T, F: Fn(&T) -> (Span, QueryJobId)>( - query_map: &QueryMap<'tcx>, - tcx: TyCtxt<'tcx>, - queries: &'a [T], - f: F, -) -> &'a T { - // Deterministically pick an entry point - // FIXME: Sort this instead - let mut hcx = tcx.create_stable_hashing_context(); - queries - .iter() - .min_by_key(|v| { - let (span, query) = f(v); - let mut stable_hasher = StableHasher::new(); - query.query(query_map).hash_stable(&mut hcx, &mut stable_hasher); - // Prefer entry points which have valid spans for nicer error messages - // We add an integer to the tuple ensuring that entry points - // with valid spans are picked first - let span_cmp = if span == DUMMY_SP { 1 } else { 0 }; - (span_cmp, stable_hasher.finish::()) - }) - .unwrap() -} - -/// Looks for query cycles starting from the last query in `jobs`. -/// If a cycle is found, all queries in the cycle is removed from `jobs` and -/// the function return true. -/// If a cycle was not found, the starting query is removed from `jobs` and -/// the function returns false. -#[cfg(parallel_compiler)] -fn remove_cycle<'tcx>( - query_map: &QueryMap<'tcx>, - jobs: &mut Vec, - wakelist: &mut Vec>>, - tcx: TyCtxt<'tcx>, -) -> bool { - let mut visited = FxHashSet::default(); - let mut stack = Vec::new(); - // Look for a cycle starting with the last query in `jobs` - if let Some(waiter) = - cycle_check(query_map, jobs.pop().unwrap(), DUMMY_SP, &mut stack, &mut visited) - { - // The stack is a vector of pairs of spans and queries; reverse it so that - // the earlier entries require later entries - let (mut spans, queries): (Vec<_>, Vec<_>) = stack.into_iter().rev().unzip(); - - // Shift the spans so that queries are matched with the span for their waitee - spans.rotate_right(1); - - // Zip them back together - let mut stack: Vec<_> = spans.into_iter().zip(queries).collect(); - - // Remove the queries in our cycle from the list of jobs to look at - for r in &stack { - jobs.remove_item(&r.1); - } - - // Find the queries in the cycle which are - // connected to queries outside the cycle - let entry_points = stack - .iter() - .filter_map(|&(span, query)| { - if query.parent(query_map).is_none() { - // This query is connected to the root (it has no query parent) - Some((span, query, None)) - } else { - let mut waiters = Vec::new(); - // Find all the direct waiters who lead to the root - visit_waiters(query_map, query, |span, waiter| { - // Mark all the other queries in the cycle as already visited - let mut visited = FxHashSet::from_iter(stack.iter().map(|q| q.1)); - - if connected_to_root(query_map, waiter, &mut visited) { - waiters.push((span, waiter)); - } - - None - }); - if waiters.is_empty() { - None - } else { - // Deterministically pick one of the waiters to show to the user - let waiter = *pick_query(query_map, tcx, &waiters, |s| *s); - Some((span, query, Some(waiter))) - } - } - }) - .collect::)>>(); - - // Deterministically pick an entry point - let (_, entry_point, usage) = pick_query(query_map, tcx, &entry_points, |e| (e.0, e.1)); - - // Shift the stack so that our entry point is first - let entry_point_pos = stack.iter().position(|(_, query)| query == entry_point); - if let Some(pos) = entry_point_pos { - stack.rotate_left(pos); - } - - let usage = usage.as_ref().map(|(span, query)| (*span, query.query(query_map))); - - // Create the cycle error - let error = CycleError { - usage, - cycle: stack - .iter() - .map(|&(s, ref q)| QueryInfo { span: s, query: q.query(query_map) }) - .collect(), - }; - - // We unwrap `waiter` here since there must always be one - // edge which is resumeable / waited using a query latch - let (waitee_query, waiter_idx) = waiter.unwrap(); - - // Extract the waiter we want to resume - let waiter = waitee_query.latch(query_map).unwrap().extract_waiter(waiter_idx); - - // Set the cycle error so it will be picked up when resumed - *waiter.cycle.lock() = Some(error); - - // Put the waiter on the list of things to resume - wakelist.push(waiter); - - true - } else { - false - } -} +use rustc_query_system::query::deadlock; +use rustc_rayon_core as rayon_core; +use std::thread; /// Creates a new thread and forwards information in thread locals to it. /// The new thread runs the deadlock handler. /// Must only be called when a deadlock is about to happen. -#[cfg(parallel_compiler)] pub unsafe fn handle_deadlock() { let registry = rayon_core::Registry::current(); @@ -546,44 +27,3 @@ pub unsafe fn handle_deadlock() { }) }); } - -/// Detects query cycles by using depth first search over all active query jobs. -/// If a query cycle is found it will break the cycle by finding an edge which -/// uses a query latch and then resuming that waiter. -/// There may be multiple cycles involved in a deadlock, so this searches -/// all active queries for cycles before finally resuming all the waiters at once. -#[cfg(parallel_compiler)] -fn deadlock(tcx: TyCtxt<'_>, registry: &rayon_core::Registry) { - let on_panic = OnDrop(|| { - eprintln!("deadlock handler panicked, aborting process"); - process::abort(); - }); - - let mut wakelist = Vec::new(); - let query_map = tcx.queries.try_collect_active_jobs().unwrap(); - let mut jobs: Vec = query_map.keys().cloned().collect(); - - let mut found_cycle = false; - - while jobs.len() > 0 { - if remove_cycle(&query_map, &mut jobs, &mut wakelist, tcx) { - found_cycle = true; - } - } - - // Check that a cycle was found. It is possible for a deadlock to occur without - // a query cycle if a query which can be waited on uses Rayon to do multithreading - // internally. Such a query (X) may be executing on 2 threads (A and B) and A may - // wait using Rayon on B. Rayon may then switch to executing another query (Y) - // which in turn will wait on X causing a deadlock. We have a false dependency from - // X to Y due to Rayon waiting and a true dependency from Y to X. The algorithm here - // only considers the true dependency and won't detect a cycle. - assert!(found_cycle); - - // FIXME: Ensure this won't cause a deadlock before we return - for waiter in wakelist.into_iter() { - waiter.notify(registry); - } - - on_panic.disable(); -} diff --git a/src/librustc/ty/query/keys.rs b/src/librustc/ty/query/keys.rs index 6be1f04efca2b..a261e484a85fa 100644 --- a/src/librustc/ty/query/keys.rs +++ b/src/librustc/ty/query/keys.rs @@ -4,10 +4,10 @@ use crate::infer::canonical::Canonical; use crate::mir; use crate::traits; use crate::ty::fast_reject::SimplifiedType; -use crate::ty::query::caches::DefaultCacheSelector; use crate::ty::subst::{GenericArg, SubstsRef}; use crate::ty::{self, Ty, TyCtxt}; use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LOCAL_CRATE}; +use rustc_query_system::query::DefaultCacheSelector; use rustc_span::symbol::Symbol; use rustc_span::{Span, DUMMY_SP}; diff --git a/src/librustc/ty/query/mod.rs b/src/librustc/ty/query/mod.rs index c75e0d95e8fdf..744237520fbfd 100644 --- a/src/librustc/ty/query/mod.rs +++ b/src/librustc/ty/query/mod.rs @@ -61,17 +61,17 @@ use std::sync::Arc; #[macro_use] mod plumbing; -pub(crate) use self::plumbing::CycleError; -use self::plumbing::*; +pub(crate) use rustc_query_system::query::CycleError; +use rustc_query_system::query::*; mod stats; pub use self::stats::print_stats; +#[cfg(parallel_compiler)] mod job; #[cfg(parallel_compiler)] pub use self::job::handle_deadlock; -use self::job::QueryJobInfo; -pub use self::job::{QueryInfo, QueryJob, QueryJobId}; +pub use rustc_query_system::query::{QueryInfo, QueryJob, QueryJobId}; mod keys; use self::keys::Key; @@ -79,13 +79,9 @@ use self::keys::Key; mod values; use self::values::Value; -mod caches; -use self::caches::CacheSelector; - -mod config; -use self::config::QueryAccessors; -pub use self::config::QueryConfig; -pub(crate) use self::config::QueryDescription; +use rustc_query_system::query::QueryAccessors; +pub use rustc_query_system::query::QueryConfig; +pub(crate) use rustc_query_system::query::QueryDescription; mod on_disk_cache; pub use self::on_disk_cache::OnDiskCache; diff --git a/src/librustc/ty/query/on_disk_cache.rs b/src/librustc/ty/query/on_disk_cache.rs index 155f792bd9d0a..8aecc0e698a8e 100644 --- a/src/librustc/ty/query/on_disk_cache.rs +++ b/src/librustc/ty/query/on_disk_cache.rs @@ -994,7 +994,8 @@ fn encode_query_results<'a, 'tcx, Q, E>( query_result_index: &mut EncodedQueryResultIndex, ) -> Result<(), E::Error> where - Q: super::config::QueryDescription<'tcx, Value: Encodable>, + Q: super::QueryDescription>, + Q::Value: Encodable, E: 'a + TyEncoder, { let _timer = tcx diff --git a/src/librustc/ty/query/plumbing.rs b/src/librustc/ty/query/plumbing.rs index c0cc119c5a125..1bb392f436fc6 100644 --- a/src/librustc/ty/query/plumbing.rs +++ b/src/librustc/ty/query/plumbing.rs @@ -2,372 +2,65 @@ //! generate the actual methods on tcx which find and execute the provider, //! manage the caches, and so forth. -use crate::dep_graph::{DepKind, DepNode, DepNodeIndex, SerializedDepNodeIndex}; -use crate::ty::query::caches::QueryCache; -use crate::ty::query::config::QueryDescription; -use crate::ty::query::job::{QueryInfo, QueryJob, QueryJobId, QueryJobInfo, QueryShardJobId}; +use crate::dep_graph::DepGraph; use crate::ty::query::Query; -use crate::ty::tls; +use crate::ty::tls::{self, ImplicitCtxt}; use crate::ty::{self, TyCtxt}; +use rustc_query_system::query::QueryContext; +use rustc_query_system::query::{CycleError, QueryJobId, QueryJobInfo}; -#[cfg(not(parallel_compiler))] -use rustc_data_structures::cold_path; -use rustc_data_structures::fx::{FxHashMap, FxHasher}; -use rustc_data_structures::sharded::Sharded; -use rustc_data_structures::sync::{Lock, LockGuard}; +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, FatalError, Handler, Level}; -use rustc_span::source_map::DUMMY_SP; +use rustc_errors::{struct_span_err, Diagnostic, DiagnosticBuilder, Handler, Level}; +use rustc_span::def_id::DefId; use rustc_span::Span; -use std::collections::hash_map::Entry; -use std::convert::TryFrom; -use std::fmt::Debug; -use std::hash::{Hash, Hasher}; -use std::mem; -use std::num::NonZeroU32; -use std::ptr; -#[cfg(debug_assertions)] -use std::sync::atomic::{AtomicUsize, Ordering}; - -pub(crate) struct QueryStateShard<'tcx, K, C> { - cache: C, - active: FxHashMap>, - - /// Used to generate unique ids for active jobs. - jobs: u32, -} -impl<'tcx, K, C> QueryStateShard<'tcx, K, C> { - fn get_cache(&mut self) -> &mut C { - &mut self.cache - } -} +impl QueryContext for TyCtxt<'tcx> { + type Query = Query<'tcx>; -impl<'tcx, K, C: Default> Default for QueryStateShard<'tcx, K, C> { - fn default() -> QueryStateShard<'tcx, K, C> { - QueryStateShard { cache: Default::default(), active: Default::default(), jobs: 0 } + fn incremental_verify_ich(&self) -> bool { + self.sess.opts.debugging_opts.incremental_verify_ich } -} - -pub(crate) struct QueryState<'tcx, C: QueryCache> { - cache: C, - shards: Sharded>, - #[cfg(debug_assertions)] - pub(super) cache_hits: AtomicUsize, -} - -impl<'tcx, C: QueryCache> QueryState<'tcx, C> { - pub(super) fn get_lookup( - &'tcx self, - key: &K2, - ) -> QueryLookup<'tcx, C::Key, C::Sharded> { - // We compute the key's hash once and then use it for both the - // shard lookup and the hashmap lookup. This relies on the fact - // that both of them use `FxHasher`. - let mut hasher = FxHasher::default(); - key.hash(&mut hasher); - let key_hash = hasher.finish(); - - let shard = self.shards.get_shard_index_by_hash(key_hash); - let lock = self.shards.get_shard_by_index(shard).lock(); - QueryLookup { key_hash, shard, lock } + fn verbose(&self) -> bool { + self.sess.verbose() } -} - -/// Indicates the state of a query for a given key in a query map. -enum QueryResult<'tcx> { - /// An already executing query. The query job can be used to await for its completion. - Started(QueryJob<'tcx>), - - /// The query panicked. Queries trying to wait on this will raise a fatal error which will - /// silently panic. - Poisoned, -} -impl<'tcx, C: QueryCache> QueryState<'tcx, C> { - pub(super) fn iter_results( - &self, - f: impl for<'a> FnOnce( - Box + 'a>, - ) -> R, - ) -> R { - self.cache.iter(&self.shards, |shard| &mut shard.cache, f) + fn def_path_str(&self, def_id: DefId) -> String { + TyCtxt::def_path_str(*self, def_id) } - pub(super) fn all_inactive(&self) -> bool { - let shards = self.shards.lock_shards(); - shards.iter().all(|shard| shard.active.is_empty()) - } - - pub(super) fn try_collect_active_jobs( - &self, - kind: DepKind, - make_query: fn(C::Key) -> Query<'tcx>, - jobs: &mut FxHashMap>, - ) -> Option<()> - where - C::Key: Clone, - { - // We use try_lock_shards here since we are called from the - // deadlock handler, and this shouldn't be locked. - let shards = self.shards.try_lock_shards()?; - let shards = shards.iter().enumerate(); - jobs.extend(shards.flat_map(|(shard_id, shard)| { - shard.active.iter().filter_map(move |(k, v)| { - if let QueryResult::Started(ref job) = *v { - let id = - QueryJobId { job: job.id, shard: u16::try_from(shard_id).unwrap(), kind }; - let info = QueryInfo { span: job.span, query: make_query(k.clone()) }; - Some((id, QueryJobInfo { info, job: job.clone() })) - } else { - None - } - }) - })); - Some(()) + fn dep_graph(&self) -> &DepGraph { + &self.dep_graph } -} -impl<'tcx, C: QueryCache> Default for QueryState<'tcx, C> { - fn default() -> QueryState<'tcx, C> { - QueryState { - cache: C::default(), - shards: Default::default(), - #[cfg(debug_assertions)] - cache_hits: AtomicUsize::new(0), - } + fn current_query_job(&self) -> Option> { + tls::with_related_context(*self, |icx| icx.query) } -} - -/// Values used when checking a query cache which can be reused on a cache-miss to execute the query. -pub(crate) struct QueryLookup<'tcx, K, C> { - pub(super) key_hash: u64, - shard: usize, - pub(super) lock: LockGuard<'tcx, QueryStateShard<'tcx, K, C>>, -} - -/// A type representing the responsibility to execute the job in the `job` field. -/// This will poison the relevant query if dropped. -struct JobOwner<'tcx, C> -where - C: QueryCache, - C::Key: Eq + Hash + Clone + Debug, - C::Value: Clone, -{ - state: &'tcx QueryState<'tcx, C>, - key: C::Key, - id: QueryJobId, -} - -impl<'tcx, C: QueryCache> JobOwner<'tcx, C> -where - C: QueryCache, - C::Key: Eq + Hash + Clone + Debug, - C::Value: Clone, -{ - /// Either gets a `JobOwner` corresponding the query, allowing us to - /// start executing the query, or returns with the result of the query. - /// This function assumes that `try_get_cached` is already called and returned `lookup`. - /// If the query is executing elsewhere, this will wait for it and return the result. - /// If the query panicked, this will silently panic. - /// - /// This function is inlined because that results in a noticeable speed-up - /// for some compile-time benchmarks. - #[inline(always)] - fn try_start( - tcx: TyCtxt<'tcx>, - span: Span, - key: &C::Key, - mut lookup: QueryLookup<'tcx, C::Key, C::Sharded>, - ) -> TryGetJob<'tcx, C> - where - Q: QueryDescription<'tcx, Key = C::Key, Value = C::Value, Cache = C>, - { - let lock = &mut *lookup.lock; - - let (latch, mut _query_blocked_prof_timer) = match lock.active.entry((*key).clone()) { - Entry::Occupied(mut entry) => { - match entry.get_mut() { - QueryResult::Started(job) => { - // For parallel queries, we'll block and wait until the query running - // in another thread has completed. Record how long we wait in the - // self-profiler. - let _query_blocked_prof_timer = if cfg!(parallel_compiler) { - Some(tcx.prof.query_blocked()) - } else { - None - }; - - // Create the id of the job we're waiting for - let id = QueryJobId::new(job.id, lookup.shard, Q::DEP_KIND); - (job.latch(id), _query_blocked_prof_timer) - } - QueryResult::Poisoned => FatalError.raise(), - } - } - Entry::Vacant(entry) => { - // No job entry for this query. Return a new one to be started later. - - // Generate an id unique within this shard. - let id = lock.jobs.checked_add(1).unwrap(); - lock.jobs = id; - let id = QueryShardJobId(NonZeroU32::new(id).unwrap()); - - let global_id = QueryJobId::new(id, lookup.shard, Q::DEP_KIND); - - let job = tls::with_related_context(tcx, |icx| QueryJob::new(id, span, icx.query)); - - entry.insert(QueryResult::Started(job)); - - let owner = - JobOwner { state: Q::query_state(tcx), id: global_id, key: (*key).clone() }; - return TryGetJob::NotYetStarted(owner); - } - }; - mem::drop(lookup.lock); - - // If we are single-threaded we know that we have cycle error, - // so we just return the error. - #[cfg(not(parallel_compiler))] - return TryGetJob::Cycle(cold_path(|| { - Q::handle_cycle_error(tcx, latch.find_cycle_in_stack(tcx, span)) - })); - - // With parallel queries we might just have to wait on some other - // thread. - #[cfg(parallel_compiler)] - { - let result = latch.wait_on(tcx, span); - - if let Err(cycle) = result { - return TryGetJob::Cycle(Q::handle_cycle_error(tcx, cycle)); - } - - let cached = tcx.try_get_cached( - Q::query_state(tcx), - (*key).clone(), - |value, index| (value.clone(), index), - |_, _| panic!("value must be in cache after waiting"), - ); - - if let Some(prof_timer) = _query_blocked_prof_timer.take() { - prof_timer.finish_with_query_invocation_id(cached.1.into()); - } - - return TryGetJob::JobCompleted(cached); - } - } - - /// Completes the query by updating the query cache with the `result`, - /// signals the waiter and forgets the JobOwner, so it won't poison the query - #[inline(always)] - fn complete(self, tcx: TyCtxt<'tcx>, result: &C::Value, dep_node_index: DepNodeIndex) { - // We can move out of `self` here because we `mem::forget` it below - let key = unsafe { ptr::read(&self.key) }; - let state = self.state; - - // Forget ourself so our destructor won't poison the query - mem::forget(self); - - let job = { - let result = result.clone(); - let mut lock = state.shards.get_shard_by_value(&key).lock(); - let job = match lock.active.remove(&key).unwrap() { - QueryResult::Started(job) => job, - QueryResult::Poisoned => panic!(), - }; - state.cache.complete(tcx, &mut lock.cache, key, result, dep_node_index); - job - }; - - job.signal_complete(); - } -} - -#[inline(always)] -fn with_diagnostics(f: F) -> (R, ThinVec) -where - F: FnOnce(Option<&Lock>>) -> R, -{ - let diagnostics = Lock::new(ThinVec::new()); - let result = f(Some(&diagnostics)); - (result, diagnostics.into_inner()) -} - -impl<'tcx, C: QueryCache> Drop for JobOwner<'tcx, C> -where - C::Key: Eq + Hash + Clone + Debug, - C::Value: Clone, -{ - #[inline(never)] - #[cold] - fn drop(&mut self) { - // Poison the query so jobs waiting on it panic. - let state = self.state; - let shard = state.shards.get_shard_by_value(&self.key); - let job = { - let mut shard = shard.lock(); - let job = match shard.active.remove(&self.key).unwrap() { - QueryResult::Started(job) => job, - QueryResult::Poisoned => panic!(), - }; - shard.active.insert(self.key.clone(), QueryResult::Poisoned); - job - }; - // Also signal the completion of the job, so waiters - // will continue execution. - job.signal_complete(); + fn try_collect_active_jobs( + &self, + ) -> Option, QueryJobInfo>> { + self.queries.try_collect_active_jobs() } -} -#[derive(Clone)] -pub(crate) struct CycleError<'tcx> { - /// The query and related span that uses the cycle. - pub(super) usage: Option<(Span, Query<'tcx>)>, - pub(super) cycle: Vec>, -} - -/// The result of `try_start`. -enum TryGetJob<'tcx, C: QueryCache> -where - C::Key: Eq + Hash + Clone + Debug, - C::Value: Clone, -{ - /// The query is not yet started. Contains a guard to the cache eventually used to start it. - NotYetStarted(JobOwner<'tcx, C>), - - /// The query was already completed. - /// Returns the result of the query and its dep-node index - /// if it succeeded or a cycle error if it failed. - #[cfg(parallel_compiler)] - JobCompleted((C::Value, DepNodeIndex)), - - /// Trying to execute the query resulted in a cycle. - Cycle(C::Value), -} - -impl<'tcx> TyCtxt<'tcx> { /// Executes a job by changing the `ImplicitCtxt` to point to the /// new query job while it executes. It returns the diagnostics /// captured during execution and the actual result. #[inline(always)] - fn start_query( - self, - token: QueryJobId, + fn start_query( + &self, + token: QueryJobId, diagnostics: Option<&Lock>>, - compute: F, - ) -> R - where - F: FnOnce(TyCtxt<'tcx>) -> R, - { + compute: impl FnOnce(Self) -> R, + ) -> R { // The `TyCtxt` stored in TLS has the same global interner lifetime // as `self`, so we use `with_related_context` to relate the 'tcx lifetimes // when accessing the `ImplicitCtxt`. - tls::with_related_context(self, move |current_icx| { + tls::with_related_context(*self, move |current_icx| { // Update the `ImplicitCtxt` to point to our new query job. - let new_icx = tls::ImplicitCtxt { - tcx: self, + let new_icx = ImplicitCtxt { + tcx: *self, query: Some(token), diagnostics, layout_depth: current_icx.layout_depth, @@ -375,15 +68,17 @@ impl<'tcx> TyCtxt<'tcx> { }; // Use the `ImplicitCtxt` while we execute the query. - tls::enter_context(&new_icx, |_| compute(self)) + tls::enter_context(&new_icx, |_| compute(*self)) }) } +} +impl<'tcx> TyCtxt<'tcx> { #[inline(never)] #[cold] pub(super) fn report_cycle( self, - CycleError { usage, cycle: stack }: CycleError<'tcx>, + CycleError { usage, cycle: stack }: CycleError>, ) -> DiagnosticBuilder<'tcx> { assert!(!stack.is_empty()); @@ -433,7 +128,7 @@ impl<'tcx> TyCtxt<'tcx> { // Be careful reyling on global state here: this code is called from // a panic hook, which means that the global `Handler` may be in a weird // state if it was responsible for triggering the panic. - tls::with_context_opt(|icx| { + ty::tls::with_context_opt(|icx| { if let Some(icx) = icx { let query_map = icx.tcx.queries.try_collect_active_jobs(); @@ -468,337 +163,6 @@ impl<'tcx> TyCtxt<'tcx> { eprintln!("end of query stack"); } - - /// Checks if the query is already computed and in the cache. - /// It returns the shard index and a lock guard to the shard, - /// which will be used if the query is not in the cache and we need - /// to compute it. - #[inline(always)] - fn try_get_cached( - self, - state: &'tcx QueryState<'tcx, C>, - key: C::Key, - // `on_hit` can be called while holding a lock to the query cache - on_hit: OnHit, - on_miss: OnMiss, - ) -> R - where - C: QueryCache, - OnHit: FnOnce(&C::Value, DepNodeIndex) -> R, - OnMiss: FnOnce(C::Key, QueryLookup<'tcx, C::Key, C::Sharded>) -> R, - { - state.cache.lookup( - state, - QueryStateShard::::get_cache, - key, - |value, index| { - if unlikely!(self.prof.enabled()) { - self.prof.query_cache_hit(index.into()); - } - #[cfg(debug_assertions)] - { - state.cache_hits.fetch_add(1, Ordering::Relaxed); - } - on_hit(value, index) - }, - on_miss, - ) - } - - #[inline(never)] - pub(super) fn get_query + 'tcx>( - self, - span: Span, - key: Q::Key, - ) -> Q::Value { - debug!("ty::query::get_query<{}>(key={:?}, span={:?})", Q::NAME, key, span); - - self.try_get_cached( - Q::query_state(self), - key, - |value, index| { - self.dep_graph.read_index(index); - value.clone() - }, - |key, lookup| self.try_execute_query::(span, key, lookup), - ) - } - - #[inline(always)] - fn try_execute_query + 'tcx>( - self, - span: Span, - key: Q::Key, - lookup: QueryLookup<'tcx, Q::Key, ::Sharded>, - ) -> Q::Value { - let job = match JobOwner::try_start::(self, span, &key, lookup) { - TryGetJob::NotYetStarted(job) => job, - TryGetJob::Cycle(result) => return result, - #[cfg(parallel_compiler)] - TryGetJob::JobCompleted((v, index)) => { - self.dep_graph.read_index(index); - return v; - } - }; - - // Fast path for when incr. comp. is off. `to_dep_node` is - // expensive for some `DepKind`s. - if !self.dep_graph.is_fully_enabled() { - let null_dep_node = DepNode::new_no_params(crate::dep_graph::DepKind::Null); - return self.force_query_with_job::(key, job, null_dep_node).0; - } - - if Q::ANON { - let prof_timer = self.prof.query_provider(); - - let ((result, dep_node_index), diagnostics) = with_diagnostics(|diagnostics| { - self.start_query(job.id, diagnostics, |tcx| { - tcx.dep_graph.with_anon_task(Q::DEP_KIND, || Q::compute(tcx, key)) - }) - }); - - prof_timer.finish_with_query_invocation_id(dep_node_index.into()); - - self.dep_graph.read_index(dep_node_index); - - if unlikely!(!diagnostics.is_empty()) { - self.queries - .on_disk_cache - .store_diagnostics_for_anon_node(dep_node_index, diagnostics); - } - - job.complete(self, &result, dep_node_index); - - return result; - } - - let dep_node = Q::to_dep_node(self, &key); - - if !Q::EVAL_ALWAYS { - // The diagnostics for this query will be - // promoted to the current session during - // `try_mark_green()`, so we can ignore them here. - let loaded = self.start_query(job.id, None, |tcx| { - let marked = tcx.dep_graph.try_mark_green_and_read(tcx, &dep_node); - marked.map(|(prev_dep_node_index, dep_node_index)| { - ( - tcx.load_from_disk_and_cache_in_memory::( - key.clone(), - prev_dep_node_index, - dep_node_index, - &dep_node, - ), - dep_node_index, - ) - }) - }); - if let Some((result, dep_node_index)) = loaded { - job.complete(self, &result, dep_node_index); - return result; - } - } - - let (result, dep_node_index) = self.force_query_with_job::(key, job, dep_node); - self.dep_graph.read_index(dep_node_index); - result - } - - fn load_from_disk_and_cache_in_memory>( - self, - key: Q::Key, - prev_dep_node_index: SerializedDepNodeIndex, - dep_node_index: DepNodeIndex, - dep_node: &DepNode, - ) -> Q::Value { - // Note this function can be called concurrently from the same query - // We must ensure that this is handled correctly. - - debug_assert!(self.dep_graph.is_green(dep_node)); - - // First we try to load the result from the on-disk cache. - let result = if Q::cache_on_disk(self, key.clone(), None) { - let prof_timer = self.prof.incr_cache_loading(); - let result = Q::try_load_from_disk(self, 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.can_reconstruct_query_key() || result.is_some(), - "missing on-disk cache entry for {:?}", - dep_node - ); - result - } else { - // Some things are never cached on disk. - None - }; - - let result = if let Some(result) = result { - result - } else { - // We could not load a result from the on-disk cache, so - // recompute. - let prof_timer = self.prof.query_provider(); - - // The dep-graph for this computation is already in-place. - let result = self.dep_graph.with_ignore(|| Q::compute(self, key)); - - prof_timer.finish_with_query_invocation_id(dep_node_index.into()); - - result - }; - - // If `-Zincremental-verify-ich` is specified, re-hash results from - // the cache and make sure that they have the expected fingerprint. - if unlikely!(self.sess.opts.debugging_opts.incremental_verify_ich) { - self.incremental_verify_ich::(&result, dep_node, dep_node_index); - } - - result - } - - #[inline(never)] - #[cold] - fn incremental_verify_ich>( - self, - result: &Q::Value, - dep_node: &DepNode, - dep_node_index: DepNodeIndex, - ) { - use rustc_data_structures::fingerprint::Fingerprint; - - assert!( - Some(self.dep_graph.fingerprint_of(dep_node_index)) - == self.dep_graph.prev_fingerprint_of(dep_node), - "fingerprint for green query instance not loaded from cache: {:?}", - dep_node, - ); - - debug!("BEGIN verify_ich({:?})", dep_node); - let mut hcx = self.create_stable_hashing_context(); - - let new_hash = Q::hash_result(&mut hcx, result).unwrap_or(Fingerprint::ZERO); - debug!("END verify_ich({:?})", dep_node); - - let old_hash = self.dep_graph.fingerprint_of(dep_node_index); - - assert!(new_hash == old_hash, "found unstable fingerprints for {:?}", dep_node,); - } - - #[inline(always)] - fn force_query_with_job + 'tcx>( - self, - key: Q::Key, - job: JobOwner<'tcx, Q::Cache>, - dep_node: DepNode, - ) -> (Q::Value, DepNodeIndex) { - // If the following assertion triggers, it can have two reasons: - // 1. Something is wrong with DepNode creation, either here or - // in `DepGraph::try_mark_green()`. - // 2. Two distinct query keys get mapped to the same `DepNode` - // (see for example #48923). - assert!( - !self.dep_graph.dep_node_exists(&dep_node), - "forcing query with already existing `DepNode`\n\ - - query-key: {:?}\n\ - - dep-node: {:?}", - key, - dep_node - ); - - let prof_timer = self.prof.query_provider(); - - let ((result, dep_node_index), diagnostics) = with_diagnostics(|diagnostics| { - self.start_query(job.id, diagnostics, |tcx| { - if Q::EVAL_ALWAYS { - tcx.dep_graph.with_eval_always_task( - dep_node, - tcx, - key, - Q::compute, - Q::hash_result, - ) - } else { - tcx.dep_graph.with_task(dep_node, tcx, key, Q::compute, Q::hash_result) - } - }) - }); - - prof_timer.finish_with_query_invocation_id(dep_node_index.into()); - - if unlikely!(!diagnostics.is_empty()) { - if dep_node.kind != crate::dep_graph::DepKind::Null { - self.queries.on_disk_cache.store_diagnostics(dep_node_index, diagnostics); - } - } - - job.complete(self, &result, dep_node_index); - - (result, dep_node_index) - } - - /// Ensure that either this query has all green inputs or been executed. - /// Executing `query::ensure(D)` is considered a read of the dep-node `D`. - /// - /// This function is particularly useful when executing passes for their - /// side-effects -- e.g., in order to report errors for erroneous programs. - /// - /// Note: The optimization is only available during incr. comp. - pub(super) fn ensure_query + 'tcx>(self, key: Q::Key) { - if Q::EVAL_ALWAYS { - let _ = self.get_query::(DUMMY_SP, key); - return; - } - - // Ensuring an anonymous query makes no sense - assert!(!Q::ANON); - - let dep_node = Q::to_dep_node(self, &key); - - match self.dep_graph.try_mark_green_and_read(self, &dep_node) { - None => { - // A None return from `try_mark_green_and_read` means that this is either - // a new dep node or that the dep node has already been marked red. - // Either way, we can't call `dep_graph.read()` as we don't have the - // DepNodeIndex. We must invoke the query itself. The performance cost - // this introduces should be negligible as we'll immediately hit the - // in-memory cache, or another query down the line will. - let _ = self.get_query::(DUMMY_SP, key); - } - Some((_, dep_node_index)) => { - self.prof.query_cache_hit(dep_node_index.into()); - } - } - } - - #[allow(dead_code)] - pub(super) fn force_query + 'tcx>( - self, - key: Q::Key, - span: Span, - dep_node: DepNode, - ) { - // We may be concurrently trying both execute and force a query. - // Ensure that only one of them runs the query. - - self.try_get_cached( - Q::query_state(self), - key, - |_, _| { - // Cache hit, do nothing - }, - |key, lookup| { - let job = match JobOwner::try_start::(self, span, &key, lookup) { - TryGetJob::NotYetStarted(job) => job, - TryGetJob::Cycle(_) => return, - #[cfg(parallel_compiler)] - TryGetJob::JobCompleted(_) => return, - }; - self.force_query_with_job::(key, job, dep_node); - }, - ); - } } macro_rules! handle_cycle_error { @@ -909,7 +273,7 @@ macro_rules! define_queries_inner { } } - pub fn describe(&self, tcx: TyCtxt<'_>) -> Cow<'static, str> { + pub fn describe(&self, tcx: TyCtxt<$tcx>) -> Cow<'static, str> { let (r, name) = match *self { $(Query::$name(key) => { (queries::$name::describe(tcx, key), stringify!($name)) @@ -956,14 +320,14 @@ macro_rules! define_queries_inner { })* } - $(impl<$tcx> QueryConfig<$tcx> for queries::$name<$tcx> { + $(impl<$tcx> QueryConfig> for queries::$name<$tcx> { type Key = $K; type Value = $V; const NAME: &'static str = stringify!($name); const CATEGORY: ProfileCategory = $category; } - impl<$tcx> QueryAccessors<$tcx> for queries::$name<$tcx> { + impl<$tcx> QueryAccessors> for queries::$name<$tcx> { const ANON: bool = is_anon!([$($modifiers)*]); const EVAL_ALWAYS: bool = is_eval_always!([$($modifiers)*]); const DEP_KIND: dep_graph::DepKind = dep_graph::DepKind::$node; @@ -971,7 +335,7 @@ macro_rules! define_queries_inner { type Cache = query_storage!([$($modifiers)*][$K, $V]); #[inline(always)] - fn query_state<'a>(tcx: TyCtxt<$tcx>) -> &'a QueryState<$tcx, Self::Cache> { + fn query_state<'a>(tcx: TyCtxt<$tcx>) -> &'a QueryState, Self::Cache> { &tcx.queries.$name } @@ -1002,7 +366,7 @@ macro_rules! define_queries_inner { fn handle_cycle_error( tcx: TyCtxt<'tcx>, - error: CycleError<'tcx> + error: CycleError> ) -> Self::Value { handle_cycle_error!([$($modifiers)*][tcx, error]) } @@ -1017,7 +381,7 @@ macro_rules! define_queries_inner { $($(#[$attr])* #[inline(always)] pub fn $name(self, key: $K) { - self.tcx.ensure_query::>(key) + ensure_query::, _>(self.tcx, key) })* } @@ -1095,7 +459,7 @@ macro_rules! define_queries_inner { $($(#[$attr])* #[inline(always)] pub fn $name(self, key: $K) -> $V { - self.tcx.get_query::>(self.span, key) + get_query::, _>(self.tcx, self.span, key) })* } @@ -1124,8 +488,8 @@ macro_rules! define_queries_struct { fallback_extern_providers: Box>, $($(#[$attr])* $name: QueryState< - $tcx, - as QueryAccessors<'tcx>>::Cache, + TyCtxt<$tcx>, + as QueryAccessors>>::Cache, >,)* } @@ -1145,12 +509,12 @@ macro_rules! define_queries_struct { pub(crate) fn try_collect_active_jobs( &self - ) -> Option>> { + ) -> Option, QueryJobInfo>>> { let mut jobs = FxHashMap::default(); $( self.$name.try_collect_active_jobs( - as QueryAccessors<'tcx>>::DEP_KIND, + as QueryAccessors>>::DEP_KIND, Query::$name, &mut jobs, )?; diff --git a/src/librustc/ty/query/profiling_support.rs b/src/librustc/ty/query/profiling_support.rs index 0081794051f37..e0d3e764dad83 100644 --- a/src/librustc/ty/query/profiling_support.rs +++ b/src/librustc/ty/query/profiling_support.rs @@ -1,11 +1,11 @@ use crate::ty::context::TyCtxt; -use crate::ty::query::caches::QueryCache; -use crate::ty::query::plumbing::QueryState; use measureme::{StringComponent, StringId}; use rustc_data_structures::fx::FxHashMap; use rustc_data_structures::profiling::SelfProfiler; use rustc_hir::def_id::{CrateNum, DefId, DefIndex, CRATE_DEF_INDEX, LOCAL_CRATE}; use rustc_hir::definitions::DefPathData; +use rustc_query_system::query::QueryCache; +use rustc_query_system::query::QueryState; use std::fmt::Debug; use std::io::Write; @@ -160,7 +160,7 @@ where pub(super) fn alloc_self_profile_query_strings_for_query_cache<'tcx, C>( tcx: TyCtxt<'tcx>, query_name: &'static str, - query_state: &QueryState<'tcx, C>, + query_state: &QueryState, C>, string_cache: &mut QueryKeyStringCache, ) where C: QueryCache, diff --git a/src/librustc/ty/query/stats.rs b/src/librustc/ty/query/stats.rs index 527bb46c90888..b496bf839ab9e 100644 --- a/src/librustc/ty/query/stats.rs +++ b/src/librustc/ty/query/stats.rs @@ -1,9 +1,9 @@ -use crate::ty::query::caches::QueryCache; -use crate::ty::query::config::QueryAccessors; -use crate::ty::query::plumbing::QueryState; use crate::ty::query::queries; use crate::ty::TyCtxt; use rustc_hir::def_id::{DefId, LOCAL_CRATE}; +use rustc_query_system::query::QueryCache; +use rustc_query_system::query::QueryState; +use rustc_query_system::query::{QueryAccessors, QueryContext}; use std::any::type_name; use std::mem; @@ -38,7 +38,10 @@ struct QueryStats { local_def_id_keys: Option, } -fn stats<'tcx, C: QueryCache>(name: &'static str, map: &QueryState<'tcx, C>) -> QueryStats { +fn stats( + name: &'static str, + map: &QueryState, +) -> QueryStats { let mut stats = QueryStats { name, #[cfg(debug_assertions)] @@ -124,7 +127,8 @@ macro_rules! print_stats { $($( queries.push(stats::< - as QueryAccessors<'_>>::Cache, + TyCtxt<'_>, + as QueryAccessors>>::Cache, >( stringify!($name), &tcx.queries.$name, diff --git a/src/librustc_codegen_llvm/context.rs b/src/librustc_codegen_llvm/context.rs index 92f59feef90fe..7e87f45ba4bb1 100644 --- a/src/librustc_codegen_llvm/context.rs +++ b/src/librustc_codegen_llvm/context.rs @@ -7,7 +7,6 @@ use crate::type_::Type; use crate::value::Value; use rustc::bug; -use rustc::dep_graph::DepGraphSafe; use rustc::mir::mono::CodegenUnit; use rustc::ty::layout::{ HasParamEnv, LayoutError, LayoutOf, PointeeInfo, Size, TyLayout, VariantIdx, @@ -90,8 +89,6 @@ pub struct CodegenCx<'ll, 'tcx> { local_gen_sym_counter: Cell, } -impl<'ll, 'tcx> DepGraphSafe for CodegenCx<'ll, 'tcx> {} - pub fn get_reloc_model(sess: &Session) -> llvm::RelocMode { let reloc_model_arg = match sess.opts.cg.relocation_model { Some(ref s) => &s[..], diff --git a/src/librustc_macros/src/query.rs b/src/librustc_macros/src/query.rs index e7005f2f5ba77..26c3bce4a9a02 100644 --- a/src/librustc_macros/src/query.rs +++ b/src/librustc_macros/src/query.rs @@ -380,7 +380,7 @@ fn add_query_description_impl( quote! { #[allow(unused_variables)] fn describe( - #tcx: TyCtxt<'_>, + #tcx: TyCtxt<'tcx>, #key: #arg, ) -> Cow<'static, str> { format!(#desc).into() @@ -393,7 +393,7 @@ fn add_query_description_impl( let desc = desc.unwrap_or(quote! {}); impls.extend(quote! { - impl<'tcx> QueryDescription<'tcx> for queries::#name<'tcx> { + impl<'tcx> QueryDescription> for queries::#name<'tcx> { #desc #cache } @@ -489,7 +489,8 @@ pub fn rustc_queries(input: TokenStream) -> TokenStream { ::rustc::dep_graph::DepKind::#name => { if <#arg as DepNodeParams>>::CAN_RECONSTRUCT_QUERY_KEY { if let Some(key) = <#arg as DepNodeParams>>::recover($tcx, $dep_node) { - $tcx.force_query::>( + force_query::, _>( + $tcx, key, DUMMY_SP, *$dep_node diff --git a/src/librustc_metadata/rmeta/decoder/cstore_impl.rs b/src/librustc_metadata/rmeta/decoder/cstore_impl.rs index b9f1dd1663eee..7a1ac9e0a60ec 100644 --- a/src/librustc_metadata/rmeta/decoder/cstore_impl.rs +++ b/src/librustc_metadata/rmeta/decoder/cstore_impl.rs @@ -37,7 +37,7 @@ macro_rules! provide { $(fn $name<$lt: $lt, T: IntoArgs>( $tcx: TyCtxt<$lt>, def_id_arg: T, - ) -> as QueryConfig<$lt>>::Value { + ) -> as QueryConfig>>::Value { let _prof_timer = $tcx.prof.generic_activity("metadata_decode_entry"); diff --git a/src/librustc_query_system/Cargo.toml b/src/librustc_query_system/Cargo.toml index a01bb5e5ea30d..e1657a8f3c607 100644 --- a/src/librustc_query_system/Cargo.toml +++ b/src/librustc_query_system/Cargo.toml @@ -11,12 +11,12 @@ doctest = false [dependencies] log = { version = "0.4", features = ["release_max_level_info", "std"] } -rustc_ast = { path = "../librustc_ast" } +rustc-rayon-core = "0.3.0" rustc_data_structures = { path = "../librustc_data_structures" } rustc_errors = { path = "../librustc_errors" } -rustc_hir = { path = "../librustc_hir" } rustc_index = { path = "../librustc_index" } rustc_macros = { path = "../librustc_macros" } rustc_serialize = { path = "../libserialize", package = "serialize" } +rustc_span = { path = "../librustc_span" } parking_lot = "0.9" smallvec = { version = "1.0", features = ["union", "may_dangle"] } diff --git a/src/librustc_query_system/dep_graph/dep_node.rs b/src/librustc_query_system/dep_graph/dep_node.rs index c6fff2f01643a..b1d332da11592 100644 --- a/src/librustc_query_system/dep_graph/dep_node.rs +++ b/src/librustc_query_system/dep_graph/dep_node.rs @@ -46,7 +46,6 @@ use super::{DepContext, DepKind}; use rustc_data_structures::fingerprint::Fingerprint; use rustc_data_structures::stable_hasher::{HashStable, StableHasher}; -use rustc_macros::HashStable_Generic; use std::fmt; use std::hash::Hash; @@ -127,7 +126,6 @@ where /// the need to be mapped or unmapped. (This ensures we can serialize /// them even in the absence of a tcx.) #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable)] -#[derive(HashStable_Generic)] pub struct WorkProductId { hash: Fingerprint, } @@ -144,3 +142,10 @@ impl WorkProductId { WorkProductId { hash: fingerprint } } } + +impl HashStable for WorkProductId { + #[inline] + fn hash_stable(&self, hcx: &mut HCX, hasher: &mut StableHasher) { + self.hash.hash_stable(hcx, hasher) + } +} diff --git a/src/librustc_query_system/dep_graph/graph.rs b/src/librustc_query_system/dep_graph/graph.rs index 7352551559cf4..73983e1644cb0 100644 --- a/src/librustc_query_system/dep_graph/graph.rs +++ b/src/librustc_query_system/dep_graph/graph.rs @@ -20,10 +20,8 @@ use std::sync::atomic::Ordering::Relaxed; use super::debug::EdgeFilter; use super::prev::PreviousDepGraph; use super::query::DepGraphQuery; -use super::safe::DepGraphSafe; use super::serialized::{SerializedDepGraph, SerializedDepNodeIndex}; use super::{DepContext, DepKind, DepNode, WorkProductId}; -use crate::{HashStableContext, HashStableContextProvider}; #[derive(Clone)] pub struct DepGraph { @@ -191,18 +189,14 @@ impl DepGraph { /// `arg` parameter. /// /// [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/incremental-compilation.html - pub fn with_task( + pub fn with_task, A, R>( &self, key: DepNode, - cx: C, + cx: Ctxt, arg: A, - task: fn(C, A) -> R, - hash_result: impl FnOnce(&mut H, &R) -> Option, - ) -> (R, DepNodeIndex) - where - C: DepGraphSafe + HashStableContextProvider, - H: HashStableContext, - { + task: fn(Ctxt, A) -> R, + hash_result: impl FnOnce(&mut Ctxt::StableHashingContext, &R) -> Option, + ) -> (R, DepNodeIndex) { self.with_task_impl( key, cx, @@ -223,13 +217,13 @@ impl DepGraph { ) } - fn with_task_impl( + fn with_task_impl, A, R>( &self, key: DepNode, - cx: C, + cx: Ctxt, arg: A, no_tcx: bool, - task: fn(C, A) -> R, + task: fn(Ctxt, A) -> R, create_task: fn(DepNode) -> Option>, finish_task_and_alloc_depnode: fn( &CurrentDepGraph, @@ -237,12 +231,8 @@ impl DepGraph { Fingerprint, Option>, ) -> DepNodeIndex, - hash_result: impl FnOnce(&mut H, &R) -> Option, - ) -> (R, DepNodeIndex) - where - C: DepGraphSafe + HashStableContextProvider, - H: HashStableContext, - { + hash_result: impl FnOnce(&mut Ctxt::StableHashingContext, &R) -> Option, + ) -> (R, DepNodeIndex) { if let Some(ref data) = self.data { let task_deps = create_task(key).map(Lock::new); @@ -251,7 +241,7 @@ impl DepGraph { // anyway so that // - we make sure that the infrastructure works and // - we can get an idea of the runtime cost. - let mut hcx = cx.get_stable_hashing_context(); + let mut hcx = cx.create_stable_hashing_context(); let result = if no_tcx { task(cx, arg) @@ -268,7 +258,7 @@ impl DepGraph { task_deps.map(|lock| lock.into_inner()), ); - let print_status = cfg!(debug_assertions) && hcx.debug_dep_tasks(); + let print_status = cfg!(debug_assertions) && cx.debug_dep_tasks(); // Determine the color of the new DepNode. if let Some(prev_index) = data.previous.node_to_index_opt(&key) { @@ -335,18 +325,14 @@ impl DepGraph { /// Executes something within an "eval-always" task which is a task /// that runs whenever anything changes. - pub fn with_eval_always_task( + pub fn with_eval_always_task, A, R>( &self, key: DepNode, - cx: C, + cx: Ctxt, arg: A, - task: fn(C, A) -> R, - hash_result: impl FnOnce(&mut H, &R) -> Option, - ) -> (R, DepNodeIndex) - where - C: DepGraphSafe + HashStableContextProvider, - H: HashStableContext, - { + task: fn(Ctxt, A) -> R, + hash_result: impl FnOnce(&mut Ctxt::StableHashingContext, &R) -> Option, + ) -> (R, DepNodeIndex) { self.with_task_impl( key, cx, diff --git a/src/librustc_query_system/dep_graph/mod.rs b/src/librustc_query_system/dep_graph/mod.rs index 825b341cd146d..fbc91575ede41 100644 --- a/src/librustc_query_system/dep_graph/mod.rs +++ b/src/librustc_query_system/dep_graph/mod.rs @@ -3,7 +3,6 @@ mod dep_node; mod graph; mod prev; mod query; -mod safe; mod serialized; pub use dep_node::{DepNode, DepNodeParams, WorkProductId}; @@ -11,8 +10,6 @@ pub use graph::WorkProductFileKind; pub use graph::{hash_result, DepGraph, DepNodeColor, DepNodeIndex, TaskDeps, WorkProduct}; pub use prev::PreviousDepGraph; pub use query::DepGraphQuery; -pub use safe::AssertDepGraphSafe; -pub use safe::DepGraphSafe; pub use serialized::{SerializedDepGraph, SerializedDepNodeIndex}; use rustc_data_structures::profiling::SelfProfilerRef; @@ -25,11 +22,13 @@ use std::hash::Hash; pub trait DepContext: Copy { type DepKind: self::DepKind; - type StableHashingContext: crate::HashStableContext; + type StableHashingContext; /// Create a hashing context for hashing new results. fn create_stable_hashing_context(&self) -> Self::StableHashingContext; + fn debug_dep_tasks(&self) -> bool; + /// Try to force a dep node to execute and see if it's green. fn try_force_from_dep_node(&self, dep_node: &DepNode) -> bool; @@ -48,12 +47,21 @@ pub trait DepContext: Copy { /// Register diagnostics for the given node, for use in next session. fn store_diagnostics(&self, dep_node_index: DepNodeIndex, diagnostics: ThinVec); + /// Register diagnostics for the given node, for use in next session. + fn store_diagnostics_for_anon_node( + &self, + dep_node_index: DepNodeIndex, + diagnostics: ThinVec, + ); + /// Access the profiler. fn profiler(&self) -> &SelfProfilerRef; } /// Describe the different families of dependency nodes. pub trait DepKind: Copy + fmt::Debug + Eq + Ord + Hash { + const NULL: Self; + /// Return whether this kind always require evaluation. fn is_eval_always(&self) -> bool; @@ -72,4 +80,6 @@ pub trait DepKind: Copy + fmt::Debug + Eq + Ord + Hash { fn read_deps(op: OP) -> () where OP: for<'a> FnOnce(Option<&'a Lock>>) -> (); + + fn can_reconstruct_query_key(&self) -> bool; } diff --git a/src/librustc_query_system/dep_graph/safe.rs b/src/librustc_query_system/dep_graph/safe.rs deleted file mode 100644 index 7bba348f8841f..0000000000000 --- a/src/librustc_query_system/dep_graph/safe.rs +++ /dev/null @@ -1,51 +0,0 @@ -//! The `DepGraphSafe` trait - -use rustc_ast::ast::NodeId; -use rustc_hir::def_id::DefId; -use rustc_hir::BodyId; - -/// The `DepGraphSafe` trait is used to specify what kinds of values -/// are safe to "leak" into a task. The idea is that this should be -/// only be implemented for things like the tcx as well as various id -/// types, which will create reads in the dep-graph whenever the trait -/// loads anything that might depend on the input program. -pub trait DepGraphSafe {} - -/// A `BodyId` on its own doesn't give access to any particular state. -/// You must fetch the state from the various maps or generate -/// on-demand queries, all of which create reads. -impl DepGraphSafe for BodyId {} - -/// A `NodeId` on its own doesn't give access to any particular state. -/// You must fetch the state from the various maps or generate -/// on-demand queries, all of which create reads. -impl DepGraphSafe for NodeId {} - -/// A `DefId` on its own doesn't give access to any particular state. -/// You must fetch the state from the various maps or generate -/// on-demand queries, all of which create reads. -impl DepGraphSafe for DefId {} - -/// Tuples make it easy to build up state. -impl DepGraphSafe for (A, B) -where - A: DepGraphSafe, - B: DepGraphSafe, -{ -} - -/// Shared ref to dep-graph-safe stuff should still be dep-graph-safe. -impl<'a, A> DepGraphSafe for &'a A where A: DepGraphSafe {} - -/// Mut ref to dep-graph-safe stuff should still be dep-graph-safe. -impl<'a, A> DepGraphSafe for &'a mut A where A: DepGraphSafe {} - -/// No data here! :) -impl DepGraphSafe for () {} - -/// A convenient override that lets you pass arbitrary state into a -/// task. Every use should be accompanied by a comment explaining why -/// it makes sense (or how it could be refactored away in the future). -pub struct AssertDepGraphSafe(pub T); - -impl DepGraphSafe for AssertDepGraphSafe {} diff --git a/src/librustc_query_system/lib.rs b/src/librustc_query_system/lib.rs index ef4886828c411..0e6a07e06d0f2 100644 --- a/src/librustc_query_system/lib.rs +++ b/src/librustc_query_system/lib.rs @@ -1,32 +1,17 @@ +#![feature(bool_to_option)] #![feature(const_fn)] #![feature(const_if_match)] #![feature(const_panic)] #![feature(core_intrinsics)] +#![feature(hash_raw_entry)] #![feature(specialization)] #![feature(stmt_expr_attributes)] +#![feature(vec_remove_item)] #[macro_use] extern crate log; +#[macro_use] +extern crate rustc_data_structures; pub mod dep_graph; - -pub trait HashStableContext { - fn debug_dep_tasks(&self) -> bool; -} - -/// Something that can provide a stable hashing context. -pub trait HashStableContextProvider { - fn get_stable_hashing_context(&self) -> Ctxt; -} - -impl> HashStableContextProvider for &T { - fn get_stable_hashing_context(&self) -> Ctxt { - (**self).get_stable_hashing_context() - } -} - -impl> HashStableContextProvider for &mut T { - fn get_stable_hashing_context(&self) -> Ctxt { - (**self).get_stable_hashing_context() - } -} +pub mod query; diff --git a/src/librustc_query_system/query/README.md b/src/librustc_query_system/query/README.md new file mode 100644 index 0000000000000..8ec07b9fdeb78 --- /dev/null +++ b/src/librustc_query_system/query/README.md @@ -0,0 +1,3 @@ +For more information about how the query system works, see the [rustc dev guide]. + +[rustc dev guide]: https://rustc-dev-guide.rust-lang.org/query.html diff --git a/src/librustc/ty/query/caches.rs b/src/librustc_query_system/query/caches.rs similarity index 72% rename from src/librustc/ty/query/caches.rs rename to src/librustc_query_system/query/caches.rs index a11b3bcba3ed3..0c0335ba04f9a 100644 --- a/src/librustc/ty/query/caches.rs +++ b/src/librustc_query_system/query/caches.rs @@ -1,6 +1,6 @@ use crate::dep_graph::DepNodeIndex; -use crate::ty::query::plumbing::{QueryLookup, QueryState, QueryStateShard}; -use crate::ty::TyCtxt; +use crate::query::plumbing::{QueryLookup, QueryState}; +use crate::query::QueryContext; use rustc_data_structures::fx::FxHashMap; use rustc_data_structures::sharded::Sharded; @@ -8,12 +8,12 @@ use std::default::Default; use std::hash::Hash; use std::marker::PhantomData; -pub(crate) trait CacheSelector { +pub trait CacheSelector { type Cache: QueryCache; } -pub(crate) trait QueryCache: Default { - type Key; +pub trait QueryCache: Default { + type Key: Hash; type Value; type Sharded: Default; @@ -21,25 +21,21 @@ pub(crate) trait QueryCache: Default { /// It returns the shard index and a lock guard to the shard, /// which will be used if the query is not in the cache and we need /// to compute it. - fn lookup<'tcx, R, GetCache, OnHit, OnMiss>( + fn lookup( &self, - state: &'tcx QueryState<'tcx, Self>, - get_cache: GetCache, + state: &QueryState, key: Self::Key, // `on_hit` can be called while holding a lock to the query state shard. on_hit: OnHit, on_miss: OnMiss, ) -> R where - GetCache: for<'a> Fn( - &'a mut QueryStateShard<'tcx, Self::Key, Self::Sharded>, - ) -> &'a mut Self::Sharded, OnHit: FnOnce(&Self::Value, DepNodeIndex) -> R, - OnMiss: FnOnce(Self::Key, QueryLookup<'tcx, Self::Key, Self::Sharded>) -> R; + OnMiss: FnOnce(Self::Key, QueryLookup<'_, CTX, Self::Key, Self::Sharded>) -> R; - fn complete( + fn complete( &self, - tcx: TyCtxt<'tcx>, + tcx: CTX, lock_sharded_storage: &mut Self::Sharded, key: Self::Key, value: Self::Value, @@ -76,32 +72,29 @@ impl QueryCache for DefaultCache { type Sharded = FxHashMap; #[inline(always)] - fn lookup<'tcx, R, GetCache, OnHit, OnMiss>( + fn lookup( &self, - state: &'tcx QueryState<'tcx, Self>, - get_cache: GetCache, + state: &QueryState, key: K, on_hit: OnHit, on_miss: OnMiss, ) -> R where - GetCache: - for<'a> Fn(&'a mut QueryStateShard<'tcx, K, Self::Sharded>) -> &'a mut Self::Sharded, OnHit: FnOnce(&V, DepNodeIndex) -> R, - OnMiss: FnOnce(K, QueryLookup<'tcx, K, Self::Sharded>) -> R, + OnMiss: FnOnce(K, QueryLookup<'_, CTX, K, Self::Sharded>) -> R, { let mut lookup = state.get_lookup(&key); let lock = &mut *lookup.lock; - let result = get_cache(lock).raw_entry().from_key_hashed_nocheck(lookup.key_hash, &key); + let result = lock.cache.raw_entry().from_key_hashed_nocheck(lookup.key_hash, &key); if let Some((_, value)) = result { on_hit(&value.0, value.1) } else { on_miss(key, lookup) } } #[inline] - fn complete( + fn complete( &self, - _: TyCtxt<'tcx>, + _: CTX, lock_sharded_storage: &mut Self::Sharded, key: K, value: V, diff --git a/src/librustc_query_system/query/config.rs b/src/librustc_query_system/query/config.rs new file mode 100644 index 0000000000000..20dad0bd47ebc --- /dev/null +++ b/src/librustc_query_system/query/config.rs @@ -0,0 +1,82 @@ +//! Query configuration and description traits. + +use crate::dep_graph::DepNode; +use crate::dep_graph::SerializedDepNodeIndex; +use crate::query::caches::QueryCache; +use crate::query::plumbing::CycleError; +use crate::query::{QueryContext, QueryState}; +use rustc_data_structures::profiling::ProfileCategory; +use rustc_span::def_id::DefId; + +use rustc_data_structures::fingerprint::Fingerprint; +use std::borrow::Cow; +use std::fmt::Debug; +use std::hash::Hash; + +// The parameter `CTX` is required in librustc: implementations may need to access the `'tcx` +// lifetime in `CTX = TyCtxt<'tcx>`. +pub trait QueryConfig { + const NAME: &'static str; + const CATEGORY: ProfileCategory; + + type Key: Eq + Hash + Clone + Debug; + type Value: Clone; +} + +pub trait QueryAccessors: QueryConfig { + const ANON: bool; + const EVAL_ALWAYS: bool; + const DEP_KIND: CTX::DepKind; + + type Cache: QueryCache; + + // Don't use this method to access query results, instead use the methods on TyCtxt + fn query_state<'a>(tcx: CTX) -> &'a QueryState; + + fn to_dep_node(tcx: CTX, key: &Self::Key) -> DepNode; + + // Don't use this method to compute query results, instead use the methods on TyCtxt + fn compute(tcx: CTX, key: Self::Key) -> Self::Value; + + fn hash_result( + hcx: &mut CTX::StableHashingContext, + result: &Self::Value, + ) -> Option; + + fn handle_cycle_error(tcx: CTX, error: CycleError) -> Self::Value; +} + +pub trait QueryDescription: QueryAccessors { + fn describe(tcx: CTX, key: Self::Key) -> Cow<'static, str>; + + #[inline] + fn cache_on_disk(_: CTX, _: Self::Key, _: Option<&Self::Value>) -> bool { + false + } + + fn try_load_from_disk(_: CTX, _: SerializedDepNodeIndex) -> Option { + panic!("QueryDescription::load_from_disk() called for an unsupported query.") + } +} + +impl QueryDescription for M +where + M: QueryAccessors, +{ + default fn describe(tcx: CTX, def_id: DefId) -> Cow<'static, str> { + if !tcx.verbose() { + format!("processing `{}`", tcx.def_path_str(def_id)).into() + } else { + let name = ::std::any::type_name::(); + format!("processing {:?} with query `{}`", def_id, name).into() + } + } + + default fn cache_on_disk(_: CTX, _: Self::Key, _: Option<&Self::Value>) -> bool { + false + } + + default fn try_load_from_disk(_: CTX, _: SerializedDepNodeIndex) -> Option { + panic!("QueryDescription::load_from_disk() called for an unsupported query.") + } +} diff --git a/src/librustc_query_system/query/job.rs b/src/librustc_query_system/query/job.rs new file mode 100644 index 0000000000000..de6dc81d8687a --- /dev/null +++ b/src/librustc_query_system/query/job.rs @@ -0,0 +1,564 @@ +use crate::dep_graph::{DepContext, DepKind}; +use crate::query::plumbing::CycleError; +use crate::query::QueryContext; + +use rustc_data_structures::fx::FxHashMap; +use rustc_span::Span; + +use std::convert::TryFrom; +use std::marker::PhantomData; +use std::num::NonZeroU32; + +#[cfg(parallel_compiler)] +use { + parking_lot::{Condvar, Mutex}, + rustc_data_structures::fx::FxHashSet, + rustc_data_structures::stable_hasher::{HashStable, StableHasher}, + rustc_data_structures::sync::Lock, + rustc_data_structures::sync::Lrc, + rustc_data_structures::{jobserver, OnDrop}, + rustc_rayon_core as rayon_core, + rustc_span::DUMMY_SP, + std::iter::FromIterator, + std::{mem, process}, +}; + +/// Represents a span and a query key. +#[derive(Clone, Debug)] +pub struct QueryInfo { + /// The span corresponding to the reason for which this query was required. + pub span: Span, + pub query: Q, +} + +type QueryMap = FxHashMap::DepKind>, QueryJobInfo>; + +/// A value uniquely identifiying an active query job within a shard in the query cache. +#[derive(Copy, Clone, Eq, PartialEq, Hash)] +pub struct QueryShardJobId(pub NonZeroU32); + +/// A value uniquely identifiying an active query job. +#[derive(Copy, Clone, Eq, PartialEq, Hash)] +pub struct QueryJobId { + /// Which job within a shard is this + pub job: QueryShardJobId, + + /// In which shard is this job + pub shard: u16, + + /// What kind of query this job is + pub kind: K, +} + +impl QueryJobId { + pub fn new(job: QueryShardJobId, shard: usize, kind: K) -> Self { + QueryJobId { job, shard: u16::try_from(shard).unwrap(), kind } + } + + fn query>(self, map: &QueryMap) -> CTX::Query { + map.get(&self).unwrap().info.query.clone() + } + + #[cfg(parallel_compiler)] + fn span>(self, map: &QueryMap) -> Span { + map.get(&self).unwrap().job.span + } + + #[cfg(parallel_compiler)] + fn parent>(self, map: &QueryMap) -> Option> { + map.get(&self).unwrap().job.parent + } + + #[cfg(parallel_compiler)] + fn latch<'a, CTX: QueryContext>( + self, + map: &'a QueryMap, + ) -> Option<&'a QueryLatch> { + map.get(&self).unwrap().job.latch.as_ref() + } +} + +pub struct QueryJobInfo { + pub info: QueryInfo, + pub job: QueryJob, +} + +/// Represents an active query job. +#[derive(Clone)] +pub struct QueryJob { + pub id: QueryShardJobId, + + /// The span corresponding to the reason for which this query was required. + pub span: Span, + + /// The parent query job which created this job and is implicitly waiting on it. + pub parent: Option>, + + /// The latch that is used to wait on this job. + #[cfg(parallel_compiler)] + latch: Option>, + + dummy: PhantomData>, +} + +impl QueryJob { + /// Creates a new query job. + pub fn new(id: QueryShardJobId, span: Span, parent: Option>) -> Self { + QueryJob { + id, + span, + parent, + #[cfg(parallel_compiler)] + latch: None, + dummy: PhantomData, + } + } + + #[cfg(parallel_compiler)] + pub(super) fn latch(&mut self, _id: QueryJobId) -> QueryLatch { + if self.latch.is_none() { + self.latch = Some(QueryLatch::new()); + } + self.latch.as_ref().unwrap().clone() + } + + #[cfg(not(parallel_compiler))] + pub(super) fn latch(&mut self, id: QueryJobId) -> QueryLatch { + QueryLatch { id, dummy: PhantomData } + } + + /// Signals to waiters that the query is complete. + /// + /// This does nothing for single threaded rustc, + /// as there are no concurrent jobs which could be waiting on us + pub fn signal_complete(self) { + #[cfg(parallel_compiler)] + self.latch.map(|latch| latch.set()); + } +} + +#[cfg(not(parallel_compiler))] +#[derive(Clone)] +pub(super) struct QueryLatch { + id: QueryJobId, + dummy: PhantomData, +} + +#[cfg(not(parallel_compiler))] +impl QueryLatch { + pub(super) fn find_cycle_in_stack(&self, tcx: CTX, span: Span) -> CycleError { + let query_map = tcx.try_collect_active_jobs().unwrap(); + + // Get the current executing query (waiter) and find the waitee amongst its parents + let mut current_job = tcx.current_query_job(); + let mut cycle = Vec::new(); + + while let Some(job) = current_job { + let info = query_map.get(&job).unwrap(); + cycle.push(info.info.clone()); + + if job == self.id { + cycle.reverse(); + + // This is the end of the cycle + // The span entry we included was for the usage + // of the cycle itself, and not part of the cycle + // Replace it with the span which caused the cycle to form + cycle[0].span = span; + // Find out why the cycle itself was used + let usage = info + .job + .parent + .as_ref() + .map(|parent| (info.info.span, parent.query(&query_map))); + return CycleError { usage, cycle }; + } + + current_job = info.job.parent; + } + + panic!("did not find a cycle") + } +} + +#[cfg(parallel_compiler)] +struct QueryWaiter { + query: Option>, + condvar: Condvar, + span: Span, + cycle: Lock>>, +} + +#[cfg(parallel_compiler)] +impl QueryWaiter { + fn notify(&self, registry: &rayon_core::Registry) { + rayon_core::mark_unblocked(registry); + self.condvar.notify_one(); + } +} + +#[cfg(parallel_compiler)] +struct QueryLatchInfo { + complete: bool, + waiters: Vec>>, +} + +#[cfg(parallel_compiler)] +#[derive(Clone)] +pub(super) struct QueryLatch { + info: Lrc>>, +} + +#[cfg(parallel_compiler)] +impl QueryLatch { + fn new() -> Self { + QueryLatch { + info: Lrc::new(Mutex::new(QueryLatchInfo { complete: false, waiters: Vec::new() })), + } + } +} + +#[cfg(parallel_compiler)] +impl QueryLatch { + /// Awaits for the query job to complete. + pub(super) fn wait_on(&self, tcx: CTX, span: Span) -> Result<(), CycleError> { + let query = tcx.current_query_job(); + let waiter = + Lrc::new(QueryWaiter { query, span, cycle: Lock::new(None), condvar: Condvar::new() }); + self.wait_on_inner(&waiter); + // FIXME: Get rid of this lock. We have ownership of the QueryWaiter + // although another thread may still have a Lrc reference so we cannot + // use Lrc::get_mut + let mut cycle = waiter.cycle.lock(); + match cycle.take() { + None => Ok(()), + Some(cycle) => Err(cycle), + } + } +} + +#[cfg(parallel_compiler)] +impl QueryLatch { + /// Awaits the caller on this latch by blocking the current thread. + fn wait_on_inner(&self, waiter: &Lrc>) { + let mut info = self.info.lock(); + if !info.complete { + // We push the waiter on to the `waiters` list. It can be accessed inside + // the `wait` call below, by 1) the `set` method or 2) by deadlock detection. + // Both of these will remove it from the `waiters` list before resuming + // this thread. + info.waiters.push(waiter.clone()); + + // If this detects a deadlock and the deadlock handler wants to resume this thread + // we have to be in the `wait` call. This is ensured by the deadlock handler + // getting the self.info lock. + rayon_core::mark_blocked(); + jobserver::release_thread(); + waiter.condvar.wait(&mut info); + // Release the lock before we potentially block in `acquire_thread` + mem::drop(info); + jobserver::acquire_thread(); + } + } + + /// Sets the latch and resumes all waiters on it + fn set(&self) { + let mut info = self.info.lock(); + debug_assert!(!info.complete); + info.complete = true; + let registry = rayon_core::Registry::current(); + for waiter in info.waiters.drain(..) { + waiter.notify(®istry); + } + } + + /// Removes a single waiter from the list of waiters. + /// This is used to break query cycles. + fn extract_waiter(&self, waiter: usize) -> Lrc> { + let mut info = self.info.lock(); + debug_assert!(!info.complete); + // Remove the waiter from the list of waiters + info.waiters.remove(waiter) + } +} + +/// A resumable waiter of a query. The usize is the index into waiters in the query's latch +#[cfg(parallel_compiler)] +type Waiter = (QueryJobId, usize); + +/// Visits all the non-resumable and resumable waiters of a query. +/// Only waiters in a query are visited. +/// `visit` is called for every waiter and is passed a query waiting on `query_ref` +/// and a span indicating the reason the query waited on `query_ref`. +/// If `visit` returns Some, this function returns. +/// For visits of non-resumable waiters it returns the return value of `visit`. +/// For visits of resumable waiters it returns Some(Some(Waiter)) which has the +/// required information to resume the waiter. +/// If all `visit` calls returns None, this function also returns None. +#[cfg(parallel_compiler)] +fn visit_waiters( + query_map: &QueryMap, + query: QueryJobId, + mut visit: F, +) -> Option>> +where + F: FnMut(Span, QueryJobId) -> Option>>, +{ + // Visit the parent query which is a non-resumable waiter since it's on the same stack + if let Some(parent) = query.parent(query_map) { + if let Some(cycle) = visit(query.span(query_map), parent) { + return Some(cycle); + } + } + + // Visit the explicit waiters which use condvars and are resumable + if let Some(latch) = query.latch(query_map) { + for (i, waiter) in latch.info.lock().waiters.iter().enumerate() { + if let Some(waiter_query) = waiter.query { + if visit(waiter.span, waiter_query).is_some() { + // Return a value which indicates that this waiter can be resumed + return Some(Some((query, i))); + } + } + } + } + + None +} + +/// Look for query cycles by doing a depth first search starting at `query`. +/// `span` is the reason for the `query` to execute. This is initially DUMMY_SP. +/// If a cycle is detected, this initial value is replaced with the span causing +/// the cycle. +#[cfg(parallel_compiler)] +fn cycle_check( + query_map: &QueryMap, + query: QueryJobId, + span: Span, + stack: &mut Vec<(Span, QueryJobId)>, + visited: &mut FxHashSet>, +) -> Option>> { + if !visited.insert(query) { + return if let Some(p) = stack.iter().position(|q| q.1 == query) { + // We detected a query cycle, fix up the initial span and return Some + + // Remove previous stack entries + stack.drain(0..p); + // Replace the span for the first query with the cycle cause + stack[0].0 = span; + Some(None) + } else { + None + }; + } + + // Query marked as visited is added it to the stack + stack.push((span, query)); + + // Visit all the waiters + let r = visit_waiters(query_map, query, |span, successor| { + cycle_check(query_map, successor, span, stack, visited) + }); + + // Remove the entry in our stack if we didn't find a cycle + if r.is_none() { + stack.pop(); + } + + r +} + +/// Finds out if there's a path to the compiler root (aka. code which isn't in a query) +/// from `query` without going through any of the queries in `visited`. +/// This is achieved with a depth first search. +#[cfg(parallel_compiler)] +fn connected_to_root( + query_map: &QueryMap, + query: QueryJobId, + visited: &mut FxHashSet>, +) -> bool { + // We already visited this or we're deliberately ignoring it + if !visited.insert(query) { + return false; + } + + // This query is connected to the root (it has no query parent), return true + if query.parent(query_map).is_none() { + return true; + } + + visit_waiters(query_map, query, |_, successor| { + connected_to_root(query_map, successor, visited).then_some(None) + }) + .is_some() +} + +// Deterministically pick an query from a list +#[cfg(parallel_compiler)] +fn pick_query<'a, CTX, T, F>(query_map: &QueryMap, tcx: CTX, queries: &'a [T], f: F) -> &'a T +where + CTX: QueryContext, + F: Fn(&T) -> (Span, QueryJobId), +{ + // Deterministically pick an entry point + // FIXME: Sort this instead + let mut hcx = tcx.create_stable_hashing_context(); + queries + .iter() + .min_by_key(|v| { + let (span, query) = f(v); + let mut stable_hasher = StableHasher::new(); + query.query(query_map).hash_stable(&mut hcx, &mut stable_hasher); + // Prefer entry points which have valid spans for nicer error messages + // We add an integer to the tuple ensuring that entry points + // with valid spans are picked first + let span_cmp = if span == DUMMY_SP { 1 } else { 0 }; + (span_cmp, stable_hasher.finish::()) + }) + .unwrap() +} + +/// Looks for query cycles starting from the last query in `jobs`. +/// If a cycle is found, all queries in the cycle is removed from `jobs` and +/// the function return true. +/// If a cycle was not found, the starting query is removed from `jobs` and +/// the function returns false. +#[cfg(parallel_compiler)] +fn remove_cycle( + query_map: &QueryMap, + jobs: &mut Vec>, + wakelist: &mut Vec>>, + tcx: CTX, +) -> bool { + let mut visited = FxHashSet::default(); + let mut stack = Vec::new(); + // Look for a cycle starting with the last query in `jobs` + if let Some(waiter) = + cycle_check(query_map, jobs.pop().unwrap(), DUMMY_SP, &mut stack, &mut visited) + { + // The stack is a vector of pairs of spans and queries; reverse it so that + // the earlier entries require later entries + let (mut spans, queries): (Vec<_>, Vec<_>) = stack.into_iter().rev().unzip(); + + // Shift the spans so that queries are matched with the span for their waitee + spans.rotate_right(1); + + // Zip them back together + let mut stack: Vec<_> = spans.into_iter().zip(queries).collect(); + + // Remove the queries in our cycle from the list of jobs to look at + for r in &stack { + jobs.remove_item(&r.1); + } + + // Find the queries in the cycle which are + // connected to queries outside the cycle + let entry_points = stack + .iter() + .filter_map(|&(span, query)| { + if query.parent(query_map).is_none() { + // This query is connected to the root (it has no query parent) + Some((span, query, None)) + } else { + let mut waiters = Vec::new(); + // Find all the direct waiters who lead to the root + visit_waiters(query_map, query, |span, waiter| { + // Mark all the other queries in the cycle as already visited + let mut visited = FxHashSet::from_iter(stack.iter().map(|q| q.1)); + + if connected_to_root(query_map, waiter, &mut visited) { + waiters.push((span, waiter)); + } + + None + }); + if waiters.is_empty() { + None + } else { + // Deterministically pick one of the waiters to show to the user + let waiter = *pick_query(query_map, tcx, &waiters, |s| *s); + Some((span, query, Some(waiter))) + } + } + }) + .collect::, Option<(Span, QueryJobId)>)>>(); + + // Deterministically pick an entry point + let (_, entry_point, usage) = pick_query(query_map, tcx, &entry_points, |e| (e.0, e.1)); + + // Shift the stack so that our entry point is first + let entry_point_pos = stack.iter().position(|(_, query)| query == entry_point); + if let Some(pos) = entry_point_pos { + stack.rotate_left(pos); + } + + let usage = usage.as_ref().map(|(span, query)| (*span, query.query(query_map))); + + // Create the cycle error + let error = CycleError { + usage, + cycle: stack + .iter() + .map(|&(s, ref q)| QueryInfo { span: s, query: q.query(query_map) }) + .collect(), + }; + + // We unwrap `waiter` here since there must always be one + // edge which is resumeable / waited using a query latch + let (waitee_query, waiter_idx) = waiter.unwrap(); + + // Extract the waiter we want to resume + let waiter = waitee_query.latch(query_map).unwrap().extract_waiter(waiter_idx); + + // Set the cycle error so it will be picked up when resumed + *waiter.cycle.lock() = Some(error); + + // Put the waiter on the list of things to resume + wakelist.push(waiter); + + true + } else { + false + } +} + +/// Detects query cycles by using depth first search over all active query jobs. +/// If a query cycle is found it will break the cycle by finding an edge which +/// uses a query latch and then resuming that waiter. +/// There may be multiple cycles involved in a deadlock, so this searches +/// all active queries for cycles before finally resuming all the waiters at once. +#[cfg(parallel_compiler)] +pub fn deadlock(tcx: CTX, registry: &rayon_core::Registry) { + let on_panic = OnDrop(|| { + eprintln!("deadlock handler panicked, aborting process"); + process::abort(); + }); + + let mut wakelist = Vec::new(); + let query_map = tcx.try_collect_active_jobs().unwrap(); + let mut jobs: Vec> = query_map.keys().cloned().collect(); + + let mut found_cycle = false; + + while jobs.len() > 0 { + if remove_cycle(&query_map, &mut jobs, &mut wakelist, tcx) { + found_cycle = true; + } + } + + // Check that a cycle was found. It is possible for a deadlock to occur without + // a query cycle if a query which can be waited on uses Rayon to do multithreading + // internally. Such a query (X) may be executing on 2 threads (A and B) and A may + // wait using Rayon on B. Rayon may then switch to executing another query (Y) + // which in turn will wait on X causing a deadlock. We have a false dependency from + // X to Y due to Rayon waiting and a true dependency from Y to X. The algorithm here + // only considers the true dependency and won't detect a cycle. + assert!(found_cycle); + + // FIXME: Ensure this won't cause a deadlock before we return + for waiter in wakelist.into_iter() { + waiter.notify(registry); + } + + on_panic.disable(); +} diff --git a/src/librustc_query_system/query/mod.rs b/src/librustc_query_system/query/mod.rs new file mode 100644 index 0000000000000..b1677c5c93da9 --- /dev/null +++ b/src/librustc_query_system/query/mod.rs @@ -0,0 +1,52 @@ +mod plumbing; +pub use self::plumbing::*; + +mod job; +#[cfg(parallel_compiler)] +pub use self::job::deadlock; +pub use self::job::{QueryInfo, QueryJob, QueryJobId, QueryJobInfo}; + +mod caches; +pub use self::caches::{CacheSelector, DefaultCacheSelector, QueryCache}; + +mod config; +pub use self::config::{QueryAccessors, QueryConfig, QueryDescription}; + +use crate::dep_graph::{DepContext, DepGraph}; + +use rustc_data_structures::fx::FxHashMap; +use rustc_data_structures::stable_hasher::HashStable; +use rustc_data_structures::sync::Lock; +use rustc_data_structures::thin_vec::ThinVec; +use rustc_errors::Diagnostic; +use rustc_span::def_id::DefId; + +pub trait QueryContext: DepContext { + type Query: Clone + HashStable; + + fn incremental_verify_ich(&self) -> bool; + fn verbose(&self) -> bool; + + /// Get string representation from DefPath. + fn def_path_str(&self, def_id: DefId) -> String; + + /// Access the DepGraph. + fn dep_graph(&self) -> &DepGraph; + + /// Get the query information from the TLS context. + fn current_query_job(&self) -> Option>; + + fn try_collect_active_jobs( + &self, + ) -> Option, QueryJobInfo>>; + + /// Executes a job by changing the `ImplicitCtxt` to point to the + /// new query job while it executes. It returns the diagnostics + /// captured during execution and the actual result. + fn start_query( + &self, + token: QueryJobId, + diagnostics: Option<&Lock>>, + compute: impl FnOnce(Self) -> R, + ) -> R; +} diff --git a/src/librustc_query_system/query/plumbing.rs b/src/librustc_query_system/query/plumbing.rs new file mode 100644 index 0000000000000..b371a914c6fce --- /dev/null +++ b/src/librustc_query_system/query/plumbing.rs @@ -0,0 +1,693 @@ +//! The implementation of the query system itself. This defines the macros that +//! generate the actual methods on tcx which find and execute the provider, +//! manage the caches, and so forth. + +use crate::dep_graph::{DepKind, DepNode}; +use crate::dep_graph::{DepNodeIndex, SerializedDepNodeIndex}; +use crate::query::caches::QueryCache; +use crate::query::config::QueryDescription; +use crate::query::job::{QueryInfo, QueryJob, QueryJobId, QueryJobInfo, QueryShardJobId}; +use crate::query::QueryContext; + +#[cfg(not(parallel_compiler))] +use rustc_data_structures::cold_path; +use rustc_data_structures::fingerprint::Fingerprint; +use rustc_data_structures::fx::{FxHashMap, FxHasher}; +use rustc_data_structures::sharded::Sharded; +use rustc_data_structures::sync::{Lock, LockGuard}; +use rustc_data_structures::thin_vec::ThinVec; +use rustc_errors::{Diagnostic, FatalError}; +use rustc_span::source_map::DUMMY_SP; +use rustc_span::Span; +use std::collections::hash_map::Entry; +use std::convert::TryFrom; +use std::fmt::Debug; +use std::hash::{Hash, Hasher}; +use std::mem; +use std::num::NonZeroU32; +use std::ptr; +#[cfg(debug_assertions)] +use std::sync::atomic::{AtomicUsize, Ordering}; + +pub struct QueryStateShard { + pub(super) cache: C, + active: FxHashMap>, + + /// Used to generate unique ids for active jobs. + jobs: u32, +} + +impl Default for QueryStateShard { + fn default() -> QueryStateShard { + QueryStateShard { cache: Default::default(), active: Default::default(), jobs: 0 } + } +} + +pub struct QueryState { + cache: C, + shards: Sharded>, + #[cfg(debug_assertions)] + pub cache_hits: AtomicUsize, +} + +impl QueryState { + pub(super) fn get_lookup<'tcx>( + &'tcx self, + key: &C::Key, + ) -> QueryLookup<'tcx, CTX, C::Key, C::Sharded> { + // We compute the key's hash once and then use it for both the + // shard lookup and the hashmap lookup. This relies on the fact + // that both of them use `FxHasher`. + let mut hasher = FxHasher::default(); + key.hash(&mut hasher); + let key_hash = hasher.finish(); + + let shard = self.shards.get_shard_index_by_hash(key_hash); + let lock = self.shards.get_shard_by_index(shard).lock(); + QueryLookup { key_hash, shard, lock } + } +} + +/// Indicates the state of a query for a given key in a query map. +enum QueryResult { + /// An already executing query. The query job can be used to await for its completion. + Started(QueryJob), + + /// The query panicked. Queries trying to wait on this will raise a fatal error which will + /// silently panic. + Poisoned, +} + +impl QueryState { + pub fn iter_results( + &self, + f: impl for<'a> FnOnce( + Box + 'a>, + ) -> R, + ) -> R { + self.cache.iter(&self.shards, |shard| &mut shard.cache, f) + } + + pub fn all_inactive(&self) -> bool { + let shards = self.shards.lock_shards(); + shards.iter().all(|shard| shard.active.is_empty()) + } + + pub fn try_collect_active_jobs( + &self, + kind: CTX::DepKind, + make_query: fn(C::Key) -> CTX::Query, + jobs: &mut FxHashMap, QueryJobInfo>, + ) -> Option<()> + where + C::Key: Clone, + { + // We use try_lock_shards here since we are called from the + // deadlock handler, and this shouldn't be locked. + let shards = self.shards.try_lock_shards()?; + let shards = shards.iter().enumerate(); + jobs.extend(shards.flat_map(|(shard_id, shard)| { + shard.active.iter().filter_map(move |(k, v)| { + if let QueryResult::Started(ref job) = *v { + let id = + QueryJobId { job: job.id, shard: u16::try_from(shard_id).unwrap(), kind }; + let info = QueryInfo { span: job.span, query: make_query(k.clone()) }; + Some((id, QueryJobInfo { info, job: job.clone() })) + } else { + None + } + }) + })); + + Some(()) + } +} + +impl Default for QueryState { + fn default() -> QueryState { + QueryState { + cache: C::default(), + shards: Default::default(), + #[cfg(debug_assertions)] + cache_hits: AtomicUsize::new(0), + } + } +} + +/// Values used when checking a query cache which can be reused on a cache-miss to execute the query. +pub struct QueryLookup<'tcx, CTX: QueryContext, K, C> { + pub(super) key_hash: u64, + shard: usize, + pub(super) lock: LockGuard<'tcx, QueryStateShard>, +} + +/// A type representing the responsibility to execute the job in the `job` field. +/// This will poison the relevant query if dropped. +struct JobOwner<'tcx, CTX: QueryContext, C> +where + C: QueryCache, + C::Key: Eq + Hash + Clone + Debug, + C::Value: Clone, +{ + state: &'tcx QueryState, + key: C::Key, + id: QueryJobId, +} + +impl<'tcx, CTX: QueryContext, C> JobOwner<'tcx, CTX, C> +where + C: QueryCache, + C::Key: Eq + Hash + Clone + Debug, + C::Value: Clone, +{ + /// Either gets a `JobOwner` corresponding the query, allowing us to + /// start executing the query, or returns with the result of the query. + /// This function assumes that `try_get_cached` is already called and returned `lookup`. + /// If the query is executing elsewhere, this will wait for it and return the result. + /// If the query panicked, this will silently panic. + /// + /// This function is inlined because that results in a noticeable speed-up + /// for some compile-time benchmarks. + #[inline(always)] + fn try_start<'a, 'b, Q>( + tcx: CTX, + span: Span, + key: &C::Key, + mut lookup: QueryLookup<'a, CTX, C::Key, C::Sharded>, + ) -> TryGetJob<'b, CTX, C> + where + Q: QueryDescription, + CTX: QueryContext, + { + let lock = &mut *lookup.lock; + + let (latch, mut _query_blocked_prof_timer) = match lock.active.entry((*key).clone()) { + Entry::Occupied(mut entry) => { + match entry.get_mut() { + QueryResult::Started(job) => { + // For parallel queries, we'll block and wait until the query running + // in another thread has completed. Record how long we wait in the + // self-profiler. + let _query_blocked_prof_timer = if cfg!(parallel_compiler) { + Some(tcx.profiler().query_blocked()) + } else { + None + }; + + // Create the id of the job we're waiting for + let id = QueryJobId::new(job.id, lookup.shard, Q::DEP_KIND); + + (job.latch(id), _query_blocked_prof_timer) + } + QueryResult::Poisoned => FatalError.raise(), + } + } + Entry::Vacant(entry) => { + // No job entry for this query. Return a new one to be started later. + + // Generate an id unique within this shard. + let id = lock.jobs.checked_add(1).unwrap(); + lock.jobs = id; + let id = QueryShardJobId(NonZeroU32::new(id).unwrap()); + + let global_id = QueryJobId::new(id, lookup.shard, Q::DEP_KIND); + + let job = tcx.current_query_job(); + let job = QueryJob::new(id, span, job); + + entry.insert(QueryResult::Started(job)); + + let owner = + JobOwner { state: Q::query_state(tcx), id: global_id, key: (*key).clone() }; + return TryGetJob::NotYetStarted(owner); + } + }; + mem::drop(lookup.lock); + + // If we are single-threaded we know that we have cycle error, + // so we just return the error. + #[cfg(not(parallel_compiler))] + return TryGetJob::Cycle(cold_path(|| { + Q::handle_cycle_error(tcx, latch.find_cycle_in_stack(tcx, span)) + })); + + // With parallel queries we might just have to wait on some other + // thread. + #[cfg(parallel_compiler)] + { + let result = latch.wait_on(tcx, span); + + if let Err(cycle) = result { + return TryGetJob::Cycle(Q::handle_cycle_error(tcx, cycle)); + } + + let cached = try_get_cached( + tcx, + Q::query_state(tcx), + (*key).clone(), + |value, index| (value.clone(), index), + |_, _| panic!("value must be in cache after waiting"), + ); + + if let Some(prof_timer) = _query_blocked_prof_timer.take() { + prof_timer.finish_with_query_invocation_id(cached.1.into()); + } + + return TryGetJob::JobCompleted(cached); + } + } + + /// Completes the query by updating the query cache with the `result`, + /// signals the waiter and forgets the JobOwner, so it won't poison the query + #[inline(always)] + fn complete(self, tcx: CTX, result: &C::Value, dep_node_index: DepNodeIndex) { + // We can move out of `self` here because we `mem::forget` it below + let key = unsafe { ptr::read(&self.key) }; + let state = self.state; + + // Forget ourself so our destructor won't poison the query + mem::forget(self); + + let job = { + let result = result.clone(); + let mut lock = state.shards.get_shard_by_value(&key).lock(); + let job = match lock.active.remove(&key).unwrap() { + QueryResult::Started(job) => job, + QueryResult::Poisoned => panic!(), + }; + state.cache.complete(tcx, &mut lock.cache, key, result, dep_node_index); + job + }; + + job.signal_complete(); + } +} + +#[inline(always)] +fn with_diagnostics(f: F) -> (R, ThinVec) +where + F: FnOnce(Option<&Lock>>) -> R, +{ + let diagnostics = Lock::new(ThinVec::new()); + let result = f(Some(&diagnostics)); + (result, diagnostics.into_inner()) +} + +impl<'tcx, CTX: QueryContext, C: QueryCache> Drop for JobOwner<'tcx, CTX, C> +where + C::Key: Eq + Hash + Clone + Debug, + C::Value: Clone, +{ + #[inline(never)] + #[cold] + fn drop(&mut self) { + // Poison the query so jobs waiting on it panic. + let state = self.state; + let shard = state.shards.get_shard_by_value(&self.key); + let job = { + let mut shard = shard.lock(); + let job = match shard.active.remove(&self.key).unwrap() { + QueryResult::Started(job) => job, + QueryResult::Poisoned => panic!(), + }; + shard.active.insert(self.key.clone(), QueryResult::Poisoned); + job + }; + // Also signal the completion of the job, so waiters + // will continue execution. + job.signal_complete(); + } +} + +#[derive(Clone)] +pub struct CycleError { + /// The query and related span that uses the cycle. + pub usage: Option<(Span, Q)>, + pub cycle: Vec>, +} + +/// The result of `try_start`. +enum TryGetJob<'tcx, CTX: QueryContext, C: QueryCache> +where + C::Key: Eq + Hash + Clone + Debug, + C::Value: Clone, +{ + /// The query is not yet started. Contains a guard to the cache eventually used to start it. + NotYetStarted(JobOwner<'tcx, CTX, C>), + + /// The query was already completed. + /// Returns the result of the query and its dep-node index + /// if it succeeded or a cycle error if it failed. + #[cfg(parallel_compiler)] + JobCompleted((C::Value, DepNodeIndex)), + + /// Trying to execute the query resulted in a cycle. + Cycle(C::Value), +} + +/// Checks if the query is already computed and in the cache. +/// It returns the shard index and a lock guard to the shard, +/// which will be used if the query is not in the cache and we need +/// to compute it. +#[inline(always)] +fn try_get_cached( + tcx: CTX, + state: &QueryState, + key: C::Key, + // `on_hit` can be called while holding a lock to the query cache + on_hit: OnHit, + on_miss: OnMiss, +) -> R +where + C: QueryCache, + CTX: QueryContext, + OnHit: FnOnce(&C::Value, DepNodeIndex) -> R, + OnMiss: FnOnce(C::Key, QueryLookup<'_, CTX, C::Key, C::Sharded>) -> R, +{ + state.cache.lookup( + state, + key, + |value, index| { + if unlikely!(tcx.profiler().enabled()) { + tcx.profiler().query_cache_hit(index.into()); + } + #[cfg(debug_assertions)] + { + state.cache_hits.fetch_add(1, Ordering::Relaxed); + } + on_hit(value, index) + }, + on_miss, + ) +} + +#[inline(always)] +fn try_execute_query( + tcx: CTX, + span: Span, + key: Q::Key, + lookup: QueryLookup<'_, CTX, Q::Key, ::Sharded>, +) -> Q::Value +where + Q: QueryDescription, + CTX: QueryContext, +{ + let job = match JobOwner::try_start::(tcx, span, &key, lookup) { + TryGetJob::NotYetStarted(job) => job, + TryGetJob::Cycle(result) => return result, + #[cfg(parallel_compiler)] + TryGetJob::JobCompleted((v, index)) => { + tcx.dep_graph().read_index(index); + return v; + } + }; + + // Fast path for when incr. comp. is off. `to_dep_node` is + // expensive for some `DepKind`s. + if !tcx.dep_graph().is_fully_enabled() { + let null_dep_node = DepNode::new_no_params(DepKind::NULL); + return force_query_with_job::(tcx, key, job, null_dep_node).0; + } + + if Q::ANON { + let prof_timer = tcx.profiler().query_provider(); + + let ((result, dep_node_index), diagnostics) = with_diagnostics(|diagnostics| { + tcx.start_query(job.id, diagnostics, |tcx| { + tcx.dep_graph().with_anon_task(Q::DEP_KIND, || Q::compute(tcx, key)) + }) + }); + + prof_timer.finish_with_query_invocation_id(dep_node_index.into()); + + tcx.dep_graph().read_index(dep_node_index); + + if unlikely!(!diagnostics.is_empty()) { + tcx.store_diagnostics_for_anon_node(dep_node_index, diagnostics); + } + + job.complete(tcx, &result, dep_node_index); + + return result; + } + + let dep_node = Q::to_dep_node(tcx, &key); + + if !Q::EVAL_ALWAYS { + // The diagnostics for this query will be + // promoted to the current session during + // `try_mark_green()`, so we can ignore them here. + let loaded = tcx.start_query(job.id, None, |tcx| { + let marked = tcx.dep_graph().try_mark_green_and_read(tcx, &dep_node); + marked.map(|(prev_dep_node_index, dep_node_index)| { + ( + load_from_disk_and_cache_in_memory::( + tcx, + key.clone(), + prev_dep_node_index, + dep_node_index, + &dep_node, + ), + dep_node_index, + ) + }) + }); + if let Some((result, dep_node_index)) = loaded { + job.complete(tcx, &result, dep_node_index); + return result; + } + } + + let (result, dep_node_index) = force_query_with_job::(tcx, key, job, dep_node); + tcx.dep_graph().read_index(dep_node_index); + result +} + +fn load_from_disk_and_cache_in_memory( + tcx: CTX, + key: Q::Key, + prev_dep_node_index: SerializedDepNodeIndex, + dep_node_index: DepNodeIndex, + dep_node: &DepNode, +) -> Q::Value +where + CTX: QueryContext, + Q: QueryDescription, +{ + // Note this function can be called concurrently from the same query + // We must ensure that this is handled correctly. + + debug_assert!(tcx.dep_graph().is_green(dep_node)); + + // First we try to load the result from the on-disk cache. + let result = if Q::cache_on_disk(tcx, key.clone(), None) { + let prof_timer = tcx.profiler().incr_cache_loading(); + let result = Q::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.can_reconstruct_query_key() || result.is_some(), + "missing on-disk cache entry for {:?}", + dep_node + ); + result + } else { + // Some things are never cached on disk. + None + }; + + let result = if let Some(result) = result { + result + } else { + // We could not load a result from the on-disk cache, so + // recompute. + let prof_timer = tcx.profiler().query_provider(); + + // The dep-graph for this computation is already in-place. + let result = tcx.dep_graph().with_ignore(|| Q::compute(tcx, key)); + + prof_timer.finish_with_query_invocation_id(dep_node_index.into()); + + result + }; + + // If `-Zincremental-verify-ich` is specified, re-hash results from + // the cache and make sure that they have the expected fingerprint. + if unlikely!(tcx.incremental_verify_ich()) { + incremental_verify_ich::(tcx, &result, dep_node, dep_node_index); + } + + result +} + +#[inline(never)] +#[cold] +fn incremental_verify_ich( + tcx: CTX, + result: &Q::Value, + dep_node: &DepNode, + dep_node_index: DepNodeIndex, +) where + CTX: QueryContext, + Q: QueryDescription, +{ + assert!( + Some(tcx.dep_graph().fingerprint_of(dep_node_index)) + == tcx.dep_graph().prev_fingerprint_of(dep_node), + "fingerprint for green query instance not loaded from cache: {:?}", + dep_node, + ); + + debug!("BEGIN verify_ich({:?})", dep_node); + let mut hcx = tcx.create_stable_hashing_context(); + + let new_hash = Q::hash_result(&mut hcx, result).unwrap_or(Fingerprint::ZERO); + debug!("END verify_ich({:?})", dep_node); + + let old_hash = tcx.dep_graph().fingerprint_of(dep_node_index); + + assert!(new_hash == old_hash, "found unstable fingerprints for {:?}", dep_node,); +} + +#[inline(always)] +fn force_query_with_job( + tcx: CTX, + key: Q::Key, + job: JobOwner<'_, CTX, Q::Cache>, + dep_node: DepNode, +) -> (Q::Value, DepNodeIndex) +where + Q: QueryDescription, + CTX: QueryContext, +{ + // If the following assertion triggers, it can have two reasons: + // 1. Something is wrong with DepNode creation, either here or + // in `DepGraph::try_mark_green()`. + // 2. Two distinct query keys get mapped to the same `DepNode` + // (see for example #48923). + assert!( + !tcx.dep_graph().dep_node_exists(&dep_node), + "forcing query with already existing `DepNode`\n\ + - query-key: {:?}\n\ + - dep-node: {:?}", + key, + dep_node + ); + + let prof_timer = tcx.profiler().query_provider(); + + let ((result, dep_node_index), diagnostics) = with_diagnostics(|diagnostics| { + tcx.start_query(job.id, diagnostics, |tcx| { + if Q::EVAL_ALWAYS { + tcx.dep_graph().with_eval_always_task( + dep_node, + tcx, + key, + Q::compute, + Q::hash_result, + ) + } else { + tcx.dep_graph().with_task(dep_node, tcx, key, Q::compute, Q::hash_result) + } + }) + }); + + prof_timer.finish_with_query_invocation_id(dep_node_index.into()); + + if unlikely!(!diagnostics.is_empty()) { + if dep_node.kind != DepKind::NULL { + tcx.store_diagnostics(dep_node_index, diagnostics); + } + } + + job.complete(tcx, &result, dep_node_index); + + (result, dep_node_index) +} + +#[inline(never)] +pub fn get_query(tcx: CTX, span: Span, key: Q::Key) -> Q::Value +where + Q: QueryDescription, + CTX: QueryContext, +{ + debug!("ty::query::get_query<{}>(key={:?}, span={:?})", Q::NAME, key, span); + + try_get_cached( + tcx, + Q::query_state(tcx), + key, + |value, index| { + tcx.dep_graph().read_index(index); + value.clone() + }, + |key, lookup| try_execute_query::(tcx, span, key, lookup), + ) +} + +/// Ensure that either this query has all green inputs or been executed. +/// Executing `query::ensure(D)` is considered a read of the dep-node `D`. +/// +/// This function is particularly useful when executing passes for their +/// side-effects -- e.g., in order to report errors for erroneous programs. +/// +/// Note: The optimization is only available during incr. comp. +pub fn ensure_query(tcx: CTX, key: Q::Key) +where + Q: QueryDescription, + CTX: QueryContext, +{ + if Q::EVAL_ALWAYS { + let _ = get_query::(tcx, DUMMY_SP, key); + return; + } + + // Ensuring an anonymous query makes no sense + assert!(!Q::ANON); + + let dep_node = Q::to_dep_node(tcx, &key); + + match tcx.dep_graph().try_mark_green_and_read(tcx, &dep_node) { + None => { + // A None return from `try_mark_green_and_read` means that this is either + // a new dep node or that the dep node has already been marked red. + // Either way, we can't call `dep_graph.read()` as we don't have the + // DepNodeIndex. We must invoke the query itself. The performance cost + // this introduces should be negligible as we'll immediately hit the + // in-memory cache, or another query down the line will. + let _ = get_query::(tcx, DUMMY_SP, key); + } + Some((_, dep_node_index)) => { + tcx.profiler().query_cache_hit(dep_node_index.into()); + } + } +} + +pub fn force_query(tcx: CTX, key: Q::Key, span: Span, dep_node: DepNode) +where + Q: QueryDescription, + CTX: QueryContext, +{ + // We may be concurrently trying both execute and force a query. + // Ensure that only one of them runs the query. + + try_get_cached( + tcx, + Q::query_state(tcx), + key, + |_, _| { + // Cache hit, do nothing + }, + |key, lookup| { + let job = match JobOwner::try_start::(tcx, span, &key, lookup) { + TryGetJob::NotYetStarted(job) => job, + TryGetJob::Cycle(_) => return, + #[cfg(parallel_compiler)] + TryGetJob::JobCompleted(_) => return, + }; + force_query_with_job::(tcx, key, job, dep_node); + }, + ); +}