-use crate::ty::{self, TyCtxt};
-use parking_lot::{Condvar, Mutex};
-use rustc_data_structures::fx::{FxHashMap, FxHashSet};
-use rustc_data_structures::profiling::QueryInvocationId;
-use rustc_data_structures::sharded::{self, Sharded};
-use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
-use rustc_data_structures::sync::{AtomicU32, AtomicU64, Lock, Lrc, Ordering};
-use rustc_errors::Diagnostic;
-use rustc_hir::def_id::DefId;
-use rustc_index::vec::{Idx, IndexVec};
-use smallvec::SmallVec;
-use std::collections::hash_map::Entry;
-use std::env;
-use std::hash::Hash;
-use std::mem;
-use std::sync::atomic::Ordering::Relaxed;
-
-use crate::ich::{Fingerprint, StableHashingContext, StableHashingContextProvider};
-
-use super::debug::EdgeFilter;
-use super::dep_node::{DepKind, DepNode, WorkProductId};
-use super::prev::PreviousDepGraph;
-use super::query::DepGraphQuery;
-use super::safe::DepGraphSafe;
-use super::serialized::{SerializedDepGraph, SerializedDepNodeIndex};
-
-#[derive(Clone)]
-pub struct DepGraph {
- data: Option<Lrc<DepGraphData>>,
-
- /// This field is used for assigning DepNodeIndices when running in
- /// non-incremental mode. Even in non-incremental mode we make sure that
- /// each task has a `DepNodeIndex` that uniquely identifies it. This unique
- /// ID is used for self-profiling.
- virtual_dep_node_index: Lrc<AtomicU32>,
-}
-
-rustc_index::newtype_index! {
- pub struct DepNodeIndex { .. }
-}
-
-impl DepNodeIndex {
- pub const INVALID: DepNodeIndex = DepNodeIndex::MAX;
-}
-
-impl std::convert::From<DepNodeIndex> for QueryInvocationId {
- #[inline]
- fn from(dep_node_index: DepNodeIndex) -> Self {
- QueryInvocationId(dep_node_index.as_u32())
- }
-}
-
-#[derive(PartialEq)]
-pub enum DepNodeColor {
- Red,
- Green(DepNodeIndex),
-}
-
-impl DepNodeColor {
- pub fn is_green(self) -> bool {
- match self {
- DepNodeColor::Red => false,
- DepNodeColor::Green(_) => true,
- }
- }
-}
-
-struct DepGraphData {
- /// The new encoding of the dependency graph, optimized for red/green
- /// tracking. The `current` field is the dependency graph of only the
- /// current compilation session: We don't merge the previous dep-graph into
- /// current one anymore.
- current: CurrentDepGraph,
-
- /// The dep-graph from the previous compilation session. It contains all
- /// nodes and edges as well as all fingerprints of nodes that have them.
- previous: PreviousDepGraph,
-
- colors: DepNodeColorMap,
-
- /// A set of loaded diagnostics that is in the progress of being emitted.
- emitting_diagnostics: Mutex<FxHashSet<DepNodeIndex>>,
-
- /// Used to wait for diagnostics to be emitted.
- emitting_diagnostics_cond_var: Condvar,
-
- /// When we load, there may be `.o` files, cached MIR, or other such
- /// things available to us. If we find that they are not dirty, we
- /// load the path to the file storing those work-products here into
- /// this map. We can later look for and extract that data.
- previous_work_products: FxHashMap<WorkProductId, WorkProduct>,
-
- dep_node_debug: Lock<FxHashMap<DepNode, String>>,
-}
-
-pub fn hash_result<R>(hcx: &mut StableHashingContext<'_>, result: &R) -> Option<Fingerprint>
-where
- R: for<'a> HashStable<StableHashingContext<'a>>,
-{
- let mut stable_hasher = StableHasher::new();
- result.hash_stable(hcx, &mut stable_hasher);
-
- Some(stable_hasher.finish())
-}
-
-impl DepGraph {
- pub fn new(
- prev_graph: PreviousDepGraph,
- prev_work_products: FxHashMap<WorkProductId, WorkProduct>,
- ) -> DepGraph {
- let prev_graph_node_count = prev_graph.node_count();
-
- DepGraph {
- data: Some(Lrc::new(DepGraphData {
- previous_work_products: prev_work_products,
- dep_node_debug: Default::default(),
- current: CurrentDepGraph::new(prev_graph_node_count),
- emitting_diagnostics: Default::default(),
- emitting_diagnostics_cond_var: Condvar::new(),
- previous: prev_graph,
- colors: DepNodeColorMap::new(prev_graph_node_count),
- })),
- virtual_dep_node_index: Lrc::new(AtomicU32::new(0)),
- }
- }
-
- pub fn new_disabled() -> DepGraph {
- DepGraph { data: None, virtual_dep_node_index: Lrc::new(AtomicU32::new(0)) }
- }
-
- /// Returns `true` if we are actually building the full dep-graph, and `false` otherwise.
- #[inline]
- pub fn is_fully_enabled(&self) -> bool {
- self.data.is_some()
- }
-
- pub fn query(&self) -> DepGraphQuery {
- let data = self.data.as_ref().unwrap().current.data.lock();
- let nodes: Vec<_> = data.iter().map(|n| n.node).collect();
- let mut edges = Vec::new();
- for (from, edge_targets) in data.iter().map(|d| (d.node, &d.edges)) {
- for &edge_target in edge_targets.iter() {
- let to = data[edge_target].node;
- edges.push((from, to));
- }
- }
-
- DepGraphQuery::new(&nodes[..], &edges[..])
- }
-
- pub fn assert_ignored(&self) {
- if let Some(..) = self.data {
- ty::tls::with_context_opt(|icx| {
- let icx = if let Some(icx) = icx { icx } else { return };
- assert!(icx.task_deps.is_none(), "expected no task dependency tracking");
- })
- }
- }
-
- pub fn with_ignore<OP, R>(&self, op: OP) -> R
- where
- OP: FnOnce() -> R,
- {
- ty::tls::with_context(|icx| {
- let icx = ty::tls::ImplicitCtxt { task_deps: None, ..icx.clone() };
-
- ty::tls::enter_context(&icx, |_| op())
- })
- }
-
- /// Starts a new dep-graph task. Dep-graph tasks are specified
- /// using a free function (`task`) and **not** a closure -- this
- /// is intentional because we want to exercise tight control over
- /// what state they have access to. In particular, we want to
- /// prevent implicit 'leaks' of tracked state into the task (which
- /// could then be read without generating correct edges in the
- /// dep-graph -- see the [rustc dev guide] for more details on
- /// the dep-graph). To this end, the task function gets exactly two
- /// pieces of state: the context `cx` and an argument `arg`. Both
- /// of these bits of state must be of some type that implements
- /// `DepGraphSafe` and hence does not leak.
- ///
- /// The choice of two arguments is not fundamental. One argument
- /// would work just as well, since multiple values can be
- /// collected using tuples. However, using two arguments works out
- /// to be quite convenient, since it is common to need a context
- /// (`cx`) and some argument (e.g., a `DefId` identifying what
- /// item to process).
- ///
- /// For cases where you need some other number of arguments:
- ///
- /// - If you only need one argument, just use `()` for the `arg`
- /// parameter.
- /// - If you need 3+ arguments, use a tuple for the
- /// `arg` parameter.
- ///
- /// [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/incremental-compilation.html
- pub fn with_task<'a, C, A, R>(
- &self,
- key: DepNode,
- cx: C,
- arg: A,
- task: fn(C, A) -> R,
- hash_result: impl FnOnce(&mut StableHashingContext<'_>, &R) -> Option<Fingerprint>,
- ) -> (R, DepNodeIndex)
- where
- C: DepGraphSafe + StableHashingContextProvider<'a>,
- {
- self.with_task_impl(
- key,
- cx,
- arg,
- false,
- task,
- |_key| {
- Some(TaskDeps {
- #[cfg(debug_assertions)]
- node: Some(_key),
- reads: SmallVec::new(),
- read_set: Default::default(),
- })
- },
- |data, key, fingerprint, task| data.complete_task(key, task.unwrap(), fingerprint),
- hash_result,
- )
- }
-
- fn with_task_impl<'a, C, A, R>(
- &self,
- key: DepNode,
- cx: C,
- arg: A,
- no_tcx: bool,
- task: fn(C, A) -> R,
- create_task: fn(DepNode) -> Option<TaskDeps>,
- finish_task_and_alloc_depnode: fn(
- &CurrentDepGraph,
- DepNode,
- Fingerprint,
- Option<TaskDeps>,
- ) -> DepNodeIndex,
- hash_result: impl FnOnce(&mut StableHashingContext<'_>, &R) -> Option<Fingerprint>,
- ) -> (R, DepNodeIndex)
- where
- C: DepGraphSafe + StableHashingContextProvider<'a>,
- {
- if let Some(ref data) = self.data {
- let task_deps = create_task(key).map(Lock::new);
-
- // In incremental mode, hash the result of the task. We don't
- // do anything with the hash yet, but we are computing it
- // 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 result = if no_tcx {
- task(cx, arg)
- } else {
- ty::tls::with_context(|icx| {
- let icx =
- ty::tls::ImplicitCtxt { task_deps: task_deps.as_ref(), ..icx.clone() };
-
- ty::tls::enter_context(&icx, |_| task(cx, arg))
- })
- };
-
- let current_fingerprint = hash_result(&mut hcx, &result);
-
- let dep_node_index = finish_task_and_alloc_depnode(
- &data.current,
- key,
- current_fingerprint.unwrap_or(Fingerprint::ZERO),
- task_deps.map(|lock| lock.into_inner()),
- );
-
- let print_status = cfg!(debug_assertions) && hcx.sess().opts.debugging_opts.dep_tasks;
-
- // Determine the color of the new DepNode.
- if let Some(prev_index) = data.previous.node_to_index_opt(&key) {
- let prev_fingerprint = data.previous.fingerprint_by_index(prev_index);
-
- let color = if let Some(current_fingerprint) = current_fingerprint {
- if current_fingerprint == prev_fingerprint {
- if print_status {
- eprintln!("[task::green] {:?}", key);
- }
- DepNodeColor::Green(dep_node_index)
- } else {
- if print_status {
- eprintln!("[task::red] {:?}", key);
- }
- DepNodeColor::Red
- }
- } else {
- if print_status {
- eprintln!("[task::unknown] {:?}", key);
- }
- // Mark the node as Red if we can't hash the result
- DepNodeColor::Red
- };
-
- debug_assert!(
- data.colors.get(prev_index).is_none(),
- "DepGraph::with_task() - Duplicate DepNodeColor \
- insertion for {:?}",
- key
- );
-
- data.colors.insert(prev_index, color);
- } else {
- if print_status {
- eprintln!("[task::new] {:?}", key);
- }
- }
-
- (result, dep_node_index)
- } else {
- (task(cx, arg), self.next_virtual_depnode_index())
- }
- }
-
- /// Executes something within an "anonymous" task, that is, a task the
- /// `DepNode` of which is determined by the list of inputs it read from.
- pub fn with_anon_task<OP, R>(&self, dep_kind: DepKind, op: OP) -> (R, DepNodeIndex)
- where
- OP: FnOnce() -> R,
- {
- if let Some(ref data) = self.data {
- let (result, task_deps) = ty::tls::with_context(|icx| {
- let task_deps = Lock::new(TaskDeps::default());
-
- let r = {
- let icx = ty::tls::ImplicitCtxt { task_deps: Some(&task_deps), ..icx.clone() };
-
- ty::tls::enter_context(&icx, |_| op())
- };
-
- (r, task_deps.into_inner())
- });
- let dep_node_index = data.current.complete_anon_task(dep_kind, task_deps);
- (result, dep_node_index)
- } else {
- (op(), self.next_virtual_depnode_index())
- }
- }
-
- /// Executes something within an "eval-always" task which is a task
- /// that runs whenever anything changes.
- pub fn with_eval_always_task<'a, C, A, R>(
- &self,
- key: DepNode,
- cx: C,
- arg: A,
- task: fn(C, A) -> R,
- hash_result: impl FnOnce(&mut StableHashingContext<'_>, &R) -> Option<Fingerprint>,
- ) -> (R, DepNodeIndex)
- where
- C: DepGraphSafe + StableHashingContextProvider<'a>,
- {
- self.with_task_impl(
- key,
- cx,
- arg,
- false,
- task,
- |_| None,
- |data, key, fingerprint, _| data.alloc_node(key, smallvec![], fingerprint),
- hash_result,
- )
- }
-
- #[inline]
- pub fn read(&self, v: DepNode) {
- if let Some(ref data) = self.data {
- let map = data.current.node_to_node_index.get_shard_by_value(&v).lock();
- if let Some(dep_node_index) = map.get(&v).copied() {
- std::mem::drop(map);
- data.read_index(dep_node_index);
- } else {
- bug!("DepKind {:?} should be pre-allocated but isn't.", v.kind)
- }
- }
- }
-
- #[inline]
- pub fn read_index(&self, dep_node_index: DepNodeIndex) {
- if let Some(ref data) = self.data {
- data.read_index(dep_node_index);
- }
- }
-
- #[inline]
- pub fn dep_node_index_of(&self, dep_node: &DepNode) -> DepNodeIndex {
- self.data
- .as_ref()
- .unwrap()
- .current
- .node_to_node_index
- .get_shard_by_value(dep_node)
- .lock()
- .get(dep_node)
- .cloned()
- .unwrap()
- }
-
- #[inline]
- pub fn dep_node_exists(&self, dep_node: &DepNode) -> bool {
- if let Some(ref data) = self.data {
- data.current
- .node_to_node_index
- .get_shard_by_value(&dep_node)
- .lock()
- .contains_key(dep_node)
- } else {
- false
- }
- }
-
- #[inline]
- pub fn fingerprint_of(&self, dep_node_index: DepNodeIndex) -> Fingerprint {
- let data = self.data.as_ref().expect("dep graph enabled").current.data.lock();
- data[dep_node_index].fingerprint
- }
-
- pub fn prev_fingerprint_of(&self, dep_node: &DepNode) -> Option<Fingerprint> {
- self.data.as_ref().unwrap().previous.fingerprint_of(dep_node)
- }
-
- #[inline]
- pub fn prev_dep_node_index_of(&self, dep_node: &DepNode) -> SerializedDepNodeIndex {
- self.data.as_ref().unwrap().previous.node_to_index(dep_node)
- }
-
- /// Checks whether a previous work product exists for `v` and, if
- /// so, return the path that leads to it. Used to skip doing work.
- pub fn previous_work_product(&self, v: &WorkProductId) -> Option<WorkProduct> {
- self.data.as_ref().and_then(|data| data.previous_work_products.get(v).cloned())
- }
-
- /// Access the map of work-products created during the cached run. Only
- /// used during saving of the dep-graph.
- pub fn previous_work_products(&self) -> &FxHashMap<WorkProductId, WorkProduct> {
- &self.data.as_ref().unwrap().previous_work_products
- }
-
- #[inline(always)]
- pub fn register_dep_node_debug_str<F>(&self, dep_node: DepNode, debug_str_gen: F)
- where
- F: FnOnce() -> String,
- {
- let dep_node_debug = &self.data.as_ref().unwrap().dep_node_debug;
-
- if dep_node_debug.borrow().contains_key(&dep_node) {
- return;
- }
- let debug_str = debug_str_gen();
- dep_node_debug.borrow_mut().insert(dep_node, debug_str);
- }
-
- pub(super) fn dep_node_debug_str(&self, dep_node: DepNode) -> Option<String> {
- self.data.as_ref()?.dep_node_debug.borrow().get(&dep_node).cloned()
- }
-
- pub fn edge_deduplication_data(&self) -> Option<(u64, u64)> {
- if cfg!(debug_assertions) {
- let current_dep_graph = &self.data.as_ref().unwrap().current;
-
- Some((
- current_dep_graph.total_read_count.load(Relaxed),
- current_dep_graph.total_duplicate_read_count.load(Relaxed),
- ))
- } else {
- None
- }
- }
-
- pub fn serialize(&self) -> SerializedDepGraph {
- let data = self.data.as_ref().unwrap().current.data.lock();
-
- let fingerprints: IndexVec<SerializedDepNodeIndex, _> =
- data.iter().map(|d| d.fingerprint).collect();
- let nodes: IndexVec<SerializedDepNodeIndex, _> = data.iter().map(|d| d.node).collect();
-
- let total_edge_count: usize = data.iter().map(|d| d.edges.len()).sum();
-
- let mut edge_list_indices = IndexVec::with_capacity(nodes.len());
- let mut edge_list_data = Vec::with_capacity(total_edge_count);
-
- for (current_dep_node_index, edges) in data.iter_enumerated().map(|(i, d)| (i, &d.edges)) {
- let start = edge_list_data.len() as u32;
- // This should really just be a memcpy :/
- edge_list_data.extend(edges.iter().map(|i| SerializedDepNodeIndex::new(i.index())));
- let end = edge_list_data.len() as u32;
-
- debug_assert_eq!(current_dep_node_index.index(), edge_list_indices.len());
- edge_list_indices.push((start, end));
- }
-
- debug_assert!(edge_list_data.len() <= u32::MAX as usize);
- debug_assert_eq!(edge_list_data.len(), total_edge_count);
-
- SerializedDepGraph { nodes, fingerprints, edge_list_indices, edge_list_data }
- }
-
- pub fn node_color(&self, dep_node: &DepNode) -> Option<DepNodeColor> {
- if let Some(ref data) = self.data {
- if let Some(prev_index) = data.previous.node_to_index_opt(dep_node) {
- return data.colors.get(prev_index);
- } else {
- // This is a node that did not exist in the previous compilation
- // session, so we consider it to be red.
- return Some(DepNodeColor::Red);
- }
- }
-
- None
- }
-
- /// Try to read a node index for the node dep_node.
- /// A node will have an index, when it's already been marked green, or when we can mark it
- /// green. This function will mark the current task as a reader of the specified node, when
- /// a node index can be found for that node.
- pub fn try_mark_green_and_read(
- &self,
- tcx: TyCtxt<'_>,
- dep_node: &DepNode,
- ) -> Option<(SerializedDepNodeIndex, DepNodeIndex)> {
- self.try_mark_green(tcx, dep_node).map(|(prev_index, dep_node_index)| {
- debug_assert!(self.is_green(&dep_node));
- self.read_index(dep_node_index);
- (prev_index, dep_node_index)
- })
- }
-
- pub fn try_mark_green(
- &self,
- tcx: TyCtxt<'_>,
- dep_node: &DepNode,
- ) -> Option<(SerializedDepNodeIndex, DepNodeIndex)> {
- debug_assert!(!dep_node.kind.is_eval_always());
-
- // Return None if the dep graph is disabled
- let data = self.data.as_ref()?;
-
- // Return None if the dep node didn't exist in the previous session
- let prev_index = data.previous.node_to_index_opt(dep_node)?;
-
- match data.colors.get(prev_index) {
- Some(DepNodeColor::Green(dep_node_index)) => Some((prev_index, dep_node_index)),
- Some(DepNodeColor::Red) => None,
- None => {
- // This DepNode and the corresponding query invocation existed
- // in the previous compilation session too, so we can try to
- // mark it as green by recursively marking all of its
- // dependencies green.
- self.try_mark_previous_green(tcx, data, prev_index, &dep_node)
- .map(|dep_node_index| (prev_index, dep_node_index))
- }
- }
- }
-
- /// Try to mark a dep-node which existed in the previous compilation session as green.
- fn try_mark_previous_green<'tcx>(
- &self,
- tcx: TyCtxt<'tcx>,
- data: &DepGraphData,
- prev_dep_node_index: SerializedDepNodeIndex,
- dep_node: &DepNode,
- ) -> Option<DepNodeIndex> {
- debug!("try_mark_previous_green({:?}) - BEGIN", dep_node);
-
- #[cfg(not(parallel_compiler))]
- {
- debug_assert!(
- !data
- .current
- .node_to_node_index
- .get_shard_by_value(dep_node)
- .lock()
- .contains_key(dep_node)
- );
- debug_assert!(data.colors.get(prev_dep_node_index).is_none());
- }
-
- // We never try to mark eval_always nodes as green
- debug_assert!(!dep_node.kind.is_eval_always());
-
- debug_assert_eq!(data.previous.index_to_node(prev_dep_node_index), *dep_node);
-
- let prev_deps = data.previous.edge_targets_from(prev_dep_node_index);
-
- let mut current_deps = SmallVec::new();
-
- for &dep_dep_node_index in prev_deps {
- let dep_dep_node_color = data.colors.get(dep_dep_node_index);
-
- match dep_dep_node_color {
- Some(DepNodeColor::Green(node_index)) => {
- // This dependency has been marked as green before, we are
- // still fine and can continue with checking the other
- // dependencies.
- debug!(
- "try_mark_previous_green({:?}) --- found dependency {:?} to \
- be immediately green",
- dep_node,
- data.previous.index_to_node(dep_dep_node_index)
- );
- current_deps.push(node_index);
- }
- Some(DepNodeColor::Red) => {
- // We found a dependency the value of which has changed
- // compared to the previous compilation session. We cannot
- // mark the DepNode as green and also don't need to bother
- // with checking any of the other dependencies.
- debug!(
- "try_mark_previous_green({:?}) - END - dependency {:?} was \
- immediately red",
- dep_node,
- data.previous.index_to_node(dep_dep_node_index)
- );
- return None;
- }
- None => {
- let dep_dep_node = &data.previous.index_to_node(dep_dep_node_index);
-
- // We don't know the state of this dependency. If it isn't
- // an eval_always node, let's try to mark it green recursively.
- if !dep_dep_node.kind.is_eval_always() {
- debug!(
- "try_mark_previous_green({:?}) --- state of dependency {:?} \
- is unknown, trying to mark it green",
- dep_node, dep_dep_node
- );
-
- let node_index = self.try_mark_previous_green(
- tcx,
- data,
- dep_dep_node_index,
- dep_dep_node,
- );
- if let Some(node_index) = node_index {
- debug!(
- "try_mark_previous_green({:?}) --- managed to MARK \
- dependency {:?} as green",
- dep_node, dep_dep_node
- );
- current_deps.push(node_index);
- continue;
- }
- } else {
- // 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
- // bug that must be fixed before removing this.
- match dep_dep_node.kind {
- DepKind::hir_owner
- | DepKind::hir_owner_nodes
- | DepKind::CrateMetadata => {
- if let Some(def_id) = dep_dep_node.extract_def_id(tcx) {
- if def_id_corresponds_to_hir_dep_node(tcx, def_id) {
- if dep_dep_node.kind == DepKind::CrateMetadata {
- // The `DefPath` has corresponding node,
- // and that node should have been marked
- // either red or green in `data.colors`.
- bug!(
- "DepNode {:?} should have been \
- pre-marked as red or green but wasn't.",
- dep_dep_node
- );
- }
- } else {
- // This `DefPath` does not have a
- // corresponding `DepNode` (e.g. a
- // struct field), and the ` DefPath`
- // collided with the `DefPath` of a
- // proper item that existed in the
- // previous compilation session.
- //
- // Since the given `DefPath` does not
- // denote the item that previously
- // existed, we just fail to mark green.
- return None;
- }
- } else {
- // If the node does not exist anymore, we
- // just fail to mark green.
- return None;
- }
- }
- _ => {
- // For other kinds of nodes it's OK to be
- // forced.
- }
- }
- }
-
- // We failed to mark it green, so we try to force the query.
- debug!(
- "try_mark_previous_green({:?}) --- trying to force \
- dependency {:?}",
- dep_node, dep_dep_node
- );
- if crate::ty::query::force_from_dep_node(tcx, dep_dep_node) {
- let dep_dep_node_color = data.colors.get(dep_dep_node_index);
-
- match dep_dep_node_color {
- Some(DepNodeColor::Green(node_index)) => {
- debug!(
- "try_mark_previous_green({:?}) --- managed to \
- FORCE dependency {:?} to green",
- dep_node, dep_dep_node
- );
- current_deps.push(node_index);
- }
- Some(DepNodeColor::Red) => {
- debug!(
- "try_mark_previous_green({:?}) - END - \
- dependency {:?} was red after forcing",
- dep_node, dep_dep_node
- );
- return None;
- }
- None => {
- if !tcx.sess.has_errors_or_delayed_span_bugs() {
- bug!(
- "try_mark_previous_green() - Forcing the DepNode \
- should have set its color"
- )
- } else {
- // If the query we just forced has resulted in
- // some kind of compilation error, we cannot rely on
- // the dep-node color having been properly updated.
- // This means that the query system has reached an
- // invalid state. We let the compiler continue (by
- // returning `None`) so it can emit error messages
- // and wind down, but rely on the fact that this
- // invalid state will not be persisted to the
- // incremental compilation cache because of
- // compilation errors being present.
- debug!(
- "try_mark_previous_green({:?}) - END - \
- dependency {:?} resulted in compilation error",
- dep_node, dep_dep_node
- );
- return None;
- }
- }
- }
- } else {
- // The DepNode could not be forced.
- debug!(
- "try_mark_previous_green({:?}) - END - dependency {:?} \
- could not be forced",
- dep_node, dep_dep_node
- );
- return None;
- }
- }
- }
- }
-
- // If we got here without hitting a `return` that means that all
- // dependencies of this DepNode could be marked as green. Therefore we
- // can also mark this DepNode as green.
-
- // There may be multiple threads trying to mark the same dep node green concurrently
-
- let dep_node_index = {
- // Copy the fingerprint from the previous graph,
- // so we don't have to recompute it
- let fingerprint = data.previous.fingerprint_by_index(prev_dep_node_index);
-
- // We allocating an entry for the node in the current dependency graph and
- // adding all the appropriate edges imported from the previous graph
- data.current.intern_node(*dep_node, current_deps, fingerprint)
- };
-
- // ... emitting any stored diagnostic ...
-
- // FIXME: Store the fact that a node has diagnostics in a bit in the dep graph somewhere
- // Maybe store a list on disk and encode this fact in the DepNodeState
- let diagnostics = tcx.queries.on_disk_cache.load_diagnostics(tcx, prev_dep_node_index);
-
- #[cfg(not(parallel_compiler))]
- debug_assert!(
- data.colors.get(prev_dep_node_index).is_none(),
- "DepGraph::try_mark_previous_green() - Duplicate DepNodeColor \
- insertion for {:?}",
- dep_node
- );
-
- if unlikely!(!diagnostics.is_empty()) {
- self.emit_diagnostics(tcx, data, dep_node_index, prev_dep_node_index, diagnostics);
- }
-
- // ... and finally storing a "Green" entry in the color map.
- // Multiple threads can all write the same color here
- data.colors.insert(prev_dep_node_index, DepNodeColor::Green(dep_node_index));
-
- debug!("try_mark_previous_green({:?}) - END - successfully marked as green", dep_node);
- Some(dep_node_index)
- }
-
- /// Atomically emits some loaded diagnostics.
- /// This may be called concurrently on multiple threads for the same dep node.
- #[cold]
- #[inline(never)]
- fn emit_diagnostics<'tcx>(
- &self,
- tcx: TyCtxt<'tcx>,
- data: &DepGraphData,
- dep_node_index: DepNodeIndex,
- prev_dep_node_index: SerializedDepNodeIndex,
- diagnostics: Vec<Diagnostic>,
- ) {
- let mut emitting = data.emitting_diagnostics.lock();
-
- if data.colors.get(prev_dep_node_index) == Some(DepNodeColor::Green(dep_node_index)) {
- // The node is already green so diagnostics must have been emitted already
- return;
- }
-
- if emitting.insert(dep_node_index) {
- // We were the first to insert the node in the set so this thread
- // must emit the diagnostics and signal other potentially waiting
- // threads after.
- mem::drop(emitting);
-
- // Promote the previous diagnostics to the current session.
- tcx.queries.on_disk_cache.store_diagnostics(dep_node_index, diagnostics.clone().into());
-
- let handle = tcx.sess.diagnostic();
-
- for diagnostic in diagnostics {
- handle.emit_diagnostic(&diagnostic);
- }
-
- // Mark the node as green now that diagnostics are emitted
- data.colors.insert(prev_dep_node_index, DepNodeColor::Green(dep_node_index));
-
- // Remove the node from the set
- data.emitting_diagnostics.lock().remove(&dep_node_index);
-
- // Wake up waiters
- data.emitting_diagnostics_cond_var.notify_all();
- } else {
- // We must wait for the other thread to finish emitting the diagnostic
-
- loop {
- data.emitting_diagnostics_cond_var.wait(&mut emitting);
- if data.colors.get(prev_dep_node_index) == Some(DepNodeColor::Green(dep_node_index))
- {
- break;
- }
- }
- }
- }
-
- // Returns true if the given node has been marked as green during the
- // current compilation session. Used in various assertions
- pub fn is_green(&self, dep_node: &DepNode) -> bool {
- self.node_color(dep_node).map(|c| c.is_green()).unwrap_or(false)
- }
-
- // This method loads all on-disk cacheable query results into memory, so
- // they can be written out to the new cache file again. Most query results
- // will already be in memory but in the case where we marked something as
- // green but then did not need the value, that value will never have been
- // loaded from disk.
- //
- // This method will only load queries that will end up in the disk cache.
- // Other queries will not be executed.
- pub fn exec_cache_promotions(&self, tcx: TyCtxt<'_>) {
- let _prof_timer = tcx.prof.generic_activity("incr_comp_query_cache_promotion");
-
- let data = self.data.as_ref().unwrap();
- for prev_index in data.colors.values.indices() {
- match data.colors.get(prev_index) {
- Some(DepNodeColor::Green(_)) => {
- let dep_node = data.previous.index_to_node(prev_index);
- dep_node.try_load_from_on_disk_cache(tcx);
- }
- None | Some(DepNodeColor::Red) => {
- // We can skip red nodes because a node can only be marked
- // as red if the query result was recomputed and thus is
- // already in memory.
- }
- }
- }
- }
-
- fn next_virtual_depnode_index(&self) -> DepNodeIndex {
- let index = self.virtual_dep_node_index.fetch_add(1, Relaxed);
- DepNodeIndex::from_u32(index)
- }
-}
-
-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
-}
-
-/// A "work product" is an intermediate result that we save into the
-/// incremental directory for later re-use. The primary example are
-/// the object files that we save for each partition at code
-/// generation time.
-///
-/// Each work product is associated with a dep-node, representing the
-/// process that produced the work-product. If that dep-node is found
-/// to be dirty when we load up, then we will delete the work-product
-/// at load time. If the work-product is found to be clean, then we
-/// will keep a record in the `previous_work_products` list.
-///
-/// In addition, work products have an associated hash. This hash is
-/// an extra hash that can be used to decide if the work-product from
-/// a previous compilation can be re-used (in addition to the dirty
-/// edges check).
-///
-/// As the primary example, consider the object files we generate for
-/// each partition. In the first run, we create partitions based on
-/// the symbols that need to be compiled. For each partition P, we
-/// hash the symbols in P and create a `WorkProduct` record associated
-/// with `DepNode::CodegenUnit(P)`; the hash is the set of symbols
-/// in P.
-///
-/// The next time we compile, if the `DepNode::CodegenUnit(P)` is
-/// judged to be clean (which means none of the things we read to
-/// generate the partition were found to be dirty), it will be loaded
-/// into previous work products. We will then regenerate the set of
-/// symbols in the partition P and hash them (note that new symbols
-/// may be added -- for example, new monomorphizations -- even if
-/// nothing in P changed!). We will compare that hash against the
-/// previous hash. If it matches up, we can reuse the object file.
-#[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
-pub struct WorkProduct {
- pub cgu_name: String,
- /// Saved files associated with this CGU.
- pub saved_files: Vec<(WorkProductFileKind, String)>,
-}
-
-#[derive(Clone, Copy, Debug, RustcEncodable, RustcDecodable, PartialEq)]
-pub enum WorkProductFileKind {
- Object,
- Bytecode,
- BytecodeCompressed,
-}
-
-#[derive(Clone)]
-struct DepNodeData {
- node: DepNode,
- edges: EdgesVec,
- fingerprint: Fingerprint,
-}
-
-/// `CurrentDepGraph` stores the dependency graph for the current session.
-/// It will be populated as we run queries or tasks.
-///
-/// The nodes in it are identified by an index (`DepNodeIndex`).
-/// The data for each node is stored in its `DepNodeData`, found in the `data` field.
-///
-/// We never remove nodes from the graph: they are only added.
-///
-/// This struct uses two locks internally. The `data` and `node_to_node_index` fields are
-/// locked separately. Operations that take a `DepNodeIndex` typically just access
-/// the data field.
-///
-/// The only operation that must manipulate both locks is adding new nodes, in which case
-/// we first acquire the `node_to_node_index` lock and then, once a new node is to be inserted,
-/// acquire the lock on `data.`
-pub(super) struct CurrentDepGraph {
- data: Lock<IndexVec<DepNodeIndex, DepNodeData>>,
- node_to_node_index: Sharded<FxHashMap<DepNode, DepNodeIndex>>,
-
- /// Used to trap when a specific edge is added to the graph.
- /// This is used for debug purposes and is only active with `debug_assertions`.
- #[allow(dead_code)]
- forbidden_edge: Option<EdgeFilter>,
-
- /// Anonymous `DepNode`s are nodes whose IDs we compute from the list of
- /// their edges. This has the beneficial side-effect that multiple anonymous
- /// nodes can be coalesced into one without changing the semantics of the
- /// dependency graph. However, the merging of nodes can lead to a subtle
- /// problem during red-green marking: The color of an anonymous node from
- /// the current session might "shadow" the color of the node with the same
- /// ID from the previous session. In order to side-step this problem, we make
- /// sure that anonymous `NodeId`s allocated in different sessions don't overlap.
- /// This is implemented by mixing a session-key into the ID fingerprint of
- /// each anon node. The session-key is just a random number generated when
- /// the `DepGraph` is created.
- anon_id_seed: Fingerprint,
-
- /// These are simple counters that are for profiling and
- /// debugging and only active with `debug_assertions`.
- total_read_count: AtomicU64,
- total_duplicate_read_count: AtomicU64,
-}
-
-impl CurrentDepGraph {
- fn new(prev_graph_node_count: usize) -> CurrentDepGraph {
- use std::time::{SystemTime, UNIX_EPOCH};
-
- let duration = SystemTime::now().duration_since(UNIX_EPOCH).unwrap();
- let nanos = duration.as_secs() * 1_000_000_000 + duration.subsec_nanos() as u64;
- let mut stable_hasher = StableHasher::new();
- nanos.hash(&mut stable_hasher);
-
- let forbidden_edge = if cfg!(debug_assertions) {
- match env::var("RUST_FORBID_DEP_GRAPH_EDGE") {
- Ok(s) => match EdgeFilter::new(&s) {
- Ok(f) => Some(f),
- Err(err) => bug!("RUST_FORBID_DEP_GRAPH_EDGE invalid: {}", err),
- },
- Err(_) => None,
- }
- } else {
- None
- };
-
- // Pre-allocate the dep node structures. We over-allocate a little so
- // that we hopefully don't have to re-allocate during this compilation
- // session. The over-allocation is 2% plus a small constant to account
- // for the fact that in very small crates 2% might not be enough.
- let new_node_count_estimate = (prev_graph_node_count * 102) / 100 + 200;
-
- CurrentDepGraph {
- data: Lock::new(IndexVec::with_capacity(new_node_count_estimate)),
- node_to_node_index: Sharded::new(|| {
- FxHashMap::with_capacity_and_hasher(
- new_node_count_estimate / sharded::SHARDS,
- Default::default(),
- )
- }),
- anon_id_seed: stable_hasher.finish(),
- forbidden_edge,
- total_read_count: AtomicU64::new(0),
- total_duplicate_read_count: AtomicU64::new(0),
- }
- }
-
- fn complete_task(
- &self,
- node: DepNode,
- task_deps: TaskDeps,
- fingerprint: Fingerprint,
- ) -> DepNodeIndex {
- self.alloc_node(node, task_deps.reads, fingerprint)
- }
-
- fn complete_anon_task(&self, kind: DepKind, task_deps: TaskDeps) -> DepNodeIndex {
- debug_assert!(!kind.is_eval_always());
-
- let mut hasher = StableHasher::new();
-
- // The dep node indices are hashed here instead of hashing the dep nodes of the
- // dependencies. These indices may refer to different nodes per session, but this isn't
- // a problem here because we that ensure the final dep node hash is per session only by
- // combining it with the per session random number `anon_id_seed`. This hash only need
- // to map the dependencies to a single value on a per session basis.
- task_deps.reads.hash(&mut hasher);
-
- let target_dep_node = DepNode {
- kind,
-
- // Fingerprint::combine() is faster than sending Fingerprint
- // through the StableHasher (at least as long as StableHasher
- // is so slow).
- hash: self.anon_id_seed.combine(hasher.finish()),
- };
-
- self.intern_node(target_dep_node, task_deps.reads, Fingerprint::ZERO)
- }
-
- fn alloc_node(
- &self,
- dep_node: DepNode,
- edges: EdgesVec,
- fingerprint: Fingerprint,
- ) -> DepNodeIndex {
- debug_assert!(
- !self.node_to_node_index.get_shard_by_value(&dep_node).lock().contains_key(&dep_node)
- );
- self.intern_node(dep_node, edges, fingerprint)
- }
-
- fn intern_node(
- &self,
- dep_node: DepNode,
- edges: EdgesVec,
- fingerprint: Fingerprint,
- ) -> DepNodeIndex {
- match self.node_to_node_index.get_shard_by_value(&dep_node).lock().entry(dep_node) {
- Entry::Occupied(entry) => *entry.get(),
- Entry::Vacant(entry) => {
- let mut data = self.data.lock();
- let dep_node_index = DepNodeIndex::new(data.len());
- data.push(DepNodeData { node: dep_node, edges, fingerprint });
- entry.insert(dep_node_index);
- dep_node_index
- }
- }
- }
-}
-
-impl DepGraphData {
- #[inline(never)]
- fn read_index(&self, source: DepNodeIndex) {
- ty::tls::with_context_opt(|icx| {
- let icx = if let Some(icx) = icx { icx } else { return };
- if let Some(task_deps) = icx.task_deps {
- let mut task_deps = task_deps.lock();
- let task_deps = &mut *task_deps;
- if cfg!(debug_assertions) {
- self.current.total_read_count.fetch_add(1, Relaxed);
- }
-
- // As long as we only have a low number of reads we can avoid doing a hash
- // insert and potentially allocating/reallocating the hashmap
- let new_read = if task_deps.reads.len() < TASK_DEPS_READS_CAP {
- task_deps.reads.iter().all(|other| *other != source)
- } else {
- task_deps.read_set.insert(source)
- };
- if new_read {
- task_deps.reads.push(source);
- if task_deps.reads.len() == TASK_DEPS_READS_CAP {
- // Fill `read_set` with what we have so far so we can use the hashset next
- // time
- task_deps.read_set.extend(task_deps.reads.iter().copied());
- }
-
- #[cfg(debug_assertions)]
- {
- if let Some(target) = task_deps.node {
- let data = self.current.data.lock();
- if let Some(ref forbidden_edge) = self.current.forbidden_edge {
- let source = data[source].node;
- if forbidden_edge.test(&source, &target) {
- bug!("forbidden edge {:?} -> {:?} created", source, target)
- }
- }
- }
- }
- } else if cfg!(debug_assertions) {
- self.current.total_duplicate_read_count.fetch_add(1, Relaxed);
- }
- }
- })
- }
-}
-
-/// The capacity of the `reads` field `SmallVec`
-const TASK_DEPS_READS_CAP: usize = 8;
-type EdgesVec = SmallVec<[DepNodeIndex; TASK_DEPS_READS_CAP]>;
-#[derive(Default)]
-pub struct TaskDeps {
- #[cfg(debug_assertions)]
- node: Option<DepNode>,
- reads: EdgesVec,
- read_set: FxHashSet<DepNodeIndex>,
-}
-
-// A data structure that stores Option<DepNodeColor> values as a contiguous
-// array, using one u32 per entry.
-struct DepNodeColorMap {
- values: IndexVec<SerializedDepNodeIndex, AtomicU32>,
-}
-
-const COMPRESSED_NONE: u32 = 0;
-const COMPRESSED_RED: u32 = 1;
-const COMPRESSED_FIRST_GREEN: u32 = 2;
-
-impl DepNodeColorMap {
- fn new(size: usize) -> DepNodeColorMap {
- DepNodeColorMap { values: (0..size).map(|_| AtomicU32::new(COMPRESSED_NONE)).collect() }
- }
-
- fn get(&self, index: SerializedDepNodeIndex) -> Option<DepNodeColor> {
- match self.values[index].load(Ordering::Acquire) {
- COMPRESSED_NONE => None,
- COMPRESSED_RED => Some(DepNodeColor::Red),
- value => {
- Some(DepNodeColor::Green(DepNodeIndex::from_u32(value - COMPRESSED_FIRST_GREEN)))
- }
- }
- }
-
- fn insert(&self, index: SerializedDepNodeIndex, color: DepNodeColor) {
- self.values[index].store(
- match color {
- DepNodeColor::Red => COMPRESSED_RED,
- DepNodeColor::Green(index) => index.as_u32() + COMPRESSED_FIRST_GREEN,
- },
- Ordering::Release,
- )
- }
-}